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1

Studies of local degradation phenomena in composite cathodes for  

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Studies of local degradation phenomena in composite cathodes for Studies of local degradation phenomena in composite cathodes for lithium-ion batteries Title Studies of local degradation phenomena in composite cathodes for lithium-ion batteries Publication Type Journal Article Year of Publication 2007 Authors Kerlau, Marie, Marek Marcinek, Venkat Srinivasan, and Robert Kostecki Journal Electrochimica Acta Volume 52 Pagination 5422-5429 Keywords cathode, degradation, li-ion battery, raman microscopy Abstract LiNi0.8Co0.15Al0.05O2 and LiNi1/3Co1/3Mn1/3O2 composite cathodes were cycled in model cells to study interfacial phenomena that could lead to electrode degradation. Ex situ spectroscopic analysis of the tested cathodes, which suffered substantial power and capacity loss, showed that the state of charge (SOC) of oxide particles on the cathode surface was highly non-uniform despite the deep discharge of the Li-ion cell at the end of the test. The inconsistent kinetic behavior of individual oxide particles was attributed to the degradation of electronic pathways within the composite cathodes. A simple theoretical model based on a distributed network showed that an increase of the contact resistance between composite electrode particles may be responsible for non-uniform local kinetic behavior of individual oxide particles and the overall degradation of electrochemical performance of composite electrodes.

2

Reprint of "Studies of local degradation phenomena in composite cathodes  

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Reprint of "Studies of local degradation phenomena in composite cathodes Reprint of "Studies of local degradation phenomena in composite cathodes for lithium-ion batteries" Title Reprint of "Studies of local degradation phenomena in composite cathodes for lithium-ion batteries" Publication Type Journal Article Year of Publication 2007 Authors Kerlau, Marie, Marek Marcinek, Venkat Srinivasan, and Robert Kostecki Journal Electrochimica Acta Volume 53 Pagination 1385-1392 Keywords cathode, degradation, li-ion battery, raman microscopy Abstract LiNi0.8Co0.15Al0.05O2 and LiNi1/3Co1/3Mn1/3O2 composite cathodes were cycled in model cells to study interfacial phenomena that could lead to electrode degradation. Ex situ spectroscopic analysis of the tested cathodes, which suffered substantial power and capacity loss, showed that the state of charge (SOC) of oxide particles on the cathode surface was highly non-uniform despite the deep discharge of the Li-ion cell at the end of the test. The inconsistent kinetic behavior of individual oxide particles was attributed to the degradation of electronic pathways within the composite cathodes. A simple theoretical model based on a distributed network showed that an increase of the contact resistance between composite electrode particles may be responsible for non-uniform local kinetic behavior of individual oxide particles and the overall degradation of electrochemical performance of composite electrodes.

3

Degradation phenomena in PEM fuel cell with dead-ended anode  

Science Journals Connector (OSTI)

Abstract To improve the performance and durability of a dead-ended anode (DEA) fuel cell, it is important to understand and characterize the degradation associated with the DEA operation. To this end, the multiple degradation phenomena in DEA operation were investigated via systematic experiments. Three lifetime degradation tests were conducted with different cell temperatures and cathode relative humidities, during which the temporal evolutions of cell voltage and high frequency resistance (HFR) were recorded. When the cathode supply was fully humidified and the cell temperature was mild, the cathode carbon corrosion was the predominant degradation observed from scanning electronic microscopy (SEM) of postmortem samples. The catalyst layer and membrane thickness were measured at multiple locations across the cell active area in order to map the degradation patterns. These observations confirm a strong correlation between the cathode carbon corrosion and the anode fuel starvation occurring near the cell outlet. When the cathode supply RH reduced to 50%, membrane pin-hole failures terminated the degradation test. Postmortem analysis showed membrane cracks and delamination in the inlet region where membrane water content was the lowest.

Toyoaki Matsuura; Jixin Chen; Jason B. Siegel; Anna G. Stefanopoulou

2013-01-01T23:59:59.000Z

4

Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance spectroscopy  

Science Journals Connector (OSTI)

Electrochemical impedance spectroscopy (EIS) is identified as one of the most promising in-situ diagnostics tools available for assessing fuel cell ageing and degradation. In this work, the degradation phenomena caused by cell polarity reversal due to fuel starvation of an open cathode 16 membrane electrode assembly (MEA) – low power (PEM) fuel cell (15 W nominal power) – is reported using EIS as a base technique. Measuring the potential of individual cells, while the fuel cell is on load, was found instrumental in assessing the “state of health” of cells at fixed current. Location of affected cells, those farthest away from hydrogen entry in the stack, was revealed by very low or even negative potential values. EIS spectra were taken at selected break-in periods during fuel cell functioning. The analysis of impedance data was made using an a priori equivalent circuit describing the transfer function of the system in question – equivalent circuit elements were evaluated by a complex non-linear least square (CNLS) fitting algorithm, and by calculating and analyzing the corresponding distribution of relaxation times (DRT). Results and interpretation of cell polarity reversal due to hydrogen starvation were complemented with ex-situ MEA cross section analysis, using scanning electron microscopy. Electrode thickness reduction and delamination of catalyst layers were observed as a result of reactions taking place during hydrogen starvation. Carbon corrosion and membrane degradation by fluoride depletion are discussed.

M.A. Travassos; Vitor V. Lopes; R.A. Silva; A.Q. Novais; C.M. Rangel

2013-01-01T23:59:59.000Z

5

Localization of degradation in InP/InGaAsP mushroom stripe lasers  

SciTech Connect

The rapid degradation observed in InP/InGaAsP mushroom stripe lasers covered with phosphosilicate glass (PSG) was investigated by comparing the light-current characteristics as a function of the preparation technique. We were able to show that the PSG-covering layer is not the reason for the rapid degradation. By inspecting the light-current characteristics before and after degradation and by additional underetching the laser structure after degradation we were able to localize the degraded regions on the open side walls of the InGaAsP active layer.

Jung, H.; Marschall, P.

1987-07-13T23:59:59.000Z

6

Electric field induced localization phenomena in a ladder network with superlattice configuration: Effect of backbone environment  

SciTech Connect

Electric field induced localization properties of a tight-binding ladder network in presence of backbone sites are investigated. Based on Green's function formalism we numerically calculate two-terminal transport together with density of states for different arrangements of atomic sites in the ladder and its backbone. Our results lead to a possibility of getting multiple mobility edges which essentially plays a switching action between a completely opaque to fully or partly conducting region upon the variation of system Fermi energy, and thus, support in fabricating mesoscopic or DNA-based switching devices.

Dutta, Paramita; Karmakar, S. N. [Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, Kolkata-700 064 (India); Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata-700 108 (India)

2014-09-15T23:59:59.000Z

7

Chemical Degradation: Correlations Between Electrolyzer and Fuel Cell Findings  

Science Journals Connector (OSTI)

Membrane chemical degradation of polymer electrolyte membrane fuel cells (PEMFCs) is summarized in this paper. ... , and cation contamination, are summarized. Localized degradations, including anode versus cathod...

Han Liu; Frank D. Coms; Jingxin Zhang…

2009-01-01T23:59:59.000Z

8

Ordering Phenomena in Undercooled Alloys  

SciTech Connect

Much of the work performed under this grant was devoted to using modern ideas in kinetics to understand atom movements in metallic alloys far from thermodynamic equilibrium. Kinetics arguments were based explicitly on the vacancy mechanism for atom movements. The emphasis was on how individual atom movements are influenced by the local chemical environment of the moving atom, and how atom movements cause changes in the local chemical environments. The author formulated a kinetic master equation method to treat atom movements on a crystal lattice with a vacancy mechanism. Some of these analyses [3,10,16] are as detailed as any treatment of the statistical kinetics of atom movements in crystalline alloys. Three results came from this work. Chronologically they were (1) A recognition that tracking time dependencies is not necessarily the best way to study kinetic phenomena. If multiple order parameters can be measured in a material, the ''kinetic path'' through the space spanned by these order parameters maybe just as informative about the chemical factors that affect atom movements [2,3,5-7,9-11,14-16,18,19,21,23,24,26,36,37]. (2) Kinetic paths need not follow the steepest gradient of the free energy function (this should be well-known), and for alloys far from equilibrium the free energy function can be almost useless in describing kinetic behavior. This is why the third result surprised me. (3) In cluster approximations with multiple order parameters, saddle points are common features of free energy functions. Interestingly, kinetic processes stall or change time scale when the kinetic path approaches a state at a saddle point in the free energy function, even though these states exist far from thermodynamic equilibrium. The author calls such a state a ''pseudostable'' (falsely stable) state [6,21,26]. I have also studied these phenomena by more ''exact'' Monte Carlo simulations. The kinetic paths showed features similar to those found in analytical theories. The author found that a microstructure with interfaces arranged in space as a periodic minimal surface is a probably an alloy at a saddle point in its free energy function [21,26,37].

Fultz, Brent

1997-07-17T23:59:59.000Z

9

Emergent Phenomena at Oxide Interfaces  

SciTech Connect

Transition metal oxides (TMOs) are an ideal arena for the study of electronic correlations because the s-electrons of the transition metal ions are removed and transferred to oxygen ions, and hence the strongly correlated d-electrons determine their physical properties such as electrical transport, magnetism, optical response, thermal conductivity, and superconductivity. These electron correlations prohibit the double occupancy of metal sites and induce a local entanglement of charge, spin, and orbital degrees of freedom. This gives rise to a variety of phenomena, e.g., Mott insulators, various charge/spin/orbital orderings, metal-insulator transitions, multiferroics, and superconductivity. In recent years, there has been a burst of activity to manipulate these phenomena, as well as create new ones, using oxide heterostructures. Most fundamental to understanding the physical properties of TMOs is the concept of symmetry of the order parameter. As Landau recognized, the essence of phase transitions is the change of the symmetry. For example, ferromagnetic ordering breaks the rotational symmetry in spin space, i.e., the ordered phase has lower symmetry than the Hamiltonian of the system. There are three most important symmetries to be considered here. (i) Spatial inversion (I), defined as r {yields} -r. In the case of an insulator, breaking this symmetry can lead to spontaneous electric polarization, i.e. ferroelectricity, or pyroelectricity once the point group belongs to polar group symmetry. (ii) Time-reversal symmetry (T) defined as t {yields} -t. In quantum mechanics, the time-evolution of the wave-function {Psi} is given by the phase factor e{sup -iEt/{h_bar}} with E being the energy, and hence time-reversal basically corresponds to taking the complex conjugate of the wave-function. Also the spin, which is induced by the 'spinning' of the particle, is reversed by time-reversal. Broken T-symmetry is most naturally associated with magnetism, since the spin operator changes sign with T-operation. (iii) Gauge symmetry (G), which is associated with a change in the phase of the wave-function as {Psi} {yields} e{sup i{theta}}{Psi}. Gauge symmetry is connected to the law of charge conservation, and broken G-symmetry corresponds to superconductivity/superfluidity. To summarize, the interplay among these electronic degrees of freedom produces various forms of symmetry breaking patterns of I, T, and G, leading to novel emergent phenomena, which can appear only by the collective behavior of electrons and cannot be expected from individual electrons. Figure 1 shows this schematically by means of several representative phenomena. From this viewpoint, the interfaces of TMOs offer a unique and important laboratory because I is already broken by the structure itself, and the detailed form of broken I-symmetry can often be designed. Also, two-dimensionality usually enhances the effects of electron correlations by reducing their kinetic energy. These two features of oxide interfaces produce many novel effects and functions that cannot be attained in bulk form. Given that the electromagnetic responses are a major source of the physical properties of solids, and new gauge structures often appear in correlated electronic systems, we put 'emergent electromagnetism' at the center of Fig. 1.

Hwang, H.Y.

2012-02-16T23:59:59.000Z

10

Next Generation Nuclear Plant Phenomena  

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High- importance phenomena related to the RPV include crack initiation and subcritical crack growth; field fabrication process control; property control in heavy...

11

Next Generation Nuclear Plant Phenomena  

NLE Websites -- All DOE Office Websites (Extended Search)

5 ORNLTM-2007147, Vol. 5 Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 5: Graphite PIRTs Office of Nuclear Regulatory Research...

12

Natural convection phenomena in a nuclear power plant during a postulated TMLB' accident  

SciTech Connect

After the TMI (Three Mile Island) accident, there has been significant interest in analyzing and understanding the phenomena that may occur in a PWR (Pressurized Water Reactor) accident which may lead to partial or total core meltdown and degradation. Natural convection is one of the important phenomena. In the present paper the results of two numerical simulations of (1) four-loop PWR and (2) three-loop PWR are presented. The simulations were performed with the COMMIX(2) computer code. Our analysis shows that in severe accident scenarios, natural convection phenomena does occur and that it helps to delay core degradation by transferring decay heat from the reactor core to other internal structures of the reactor system. The amount of heat transfer and delay in core degradation depends on the geometry and internal structures of the system and on the events of an accident.

Domanus, H.M.; Schmitt, R.C.; Sha, W.T.; Shah, V.L.; Han, J.T.

1987-01-01T23:59:59.000Z

13

Comments on Several Friction Phenomena  

Science Journals Connector (OSTI)

It is suggested that the term dry friction be limited to phenomena observed under highly outgassed conditions. Two theorems are suggested one on the distribution of heat energy between two friction surfaces and the other on the independence of the heat loss in certain clutches on the coefficient of friction.

G. P. Brewington

1951-01-01T23:59:59.000Z

14

Graphene tests of Klein phenomena  

E-Print Network (OSTI)

Graphene is characterized by chiral electronic excitations. As such it provides a perfect testing ground for the production of Klein pairs (electron/holes). If confirmed, the standard results for barrier phenomena must be reconsidered with, as a byproduct, the accumulation within the barrier of holes.

Stefano De Leo; Pietro Rotelli

2012-02-07T23:59:59.000Z

15

Induction Phenomena in Laser-Sustained Scramjets  

SciTech Connect

A preliminary study on induction phenomena in a laser-sustained scramjet was conducted. The induction processes include absorption process of a laser pulse by a reactive mixture, plasma formation, diffusion of active species, shock formation, thermalization process of ambient mixture, induction of local turbulence, etc. For observation of the initial phenomena, an experimental study on effects of a focused laser pulse (Nd:YAG, 335mJ/pulse, pulse width 5nsec) into a hydrogen-air mixture was conducted. Temporal evolutions of typical line spectrum of a laser-induced plasma of the mixture were measured with the photodiode or the photo-multiplier-tube through specific band-pass filters for each spectrum for OH, O+, N+, H, and O. It was shown that the emission from O abruptly increased at 2 nsec, peaked at about 5 nsec, followed by an abrupt drop at 6 nsec. The emission from H atoms secondly increased. Other emissions of N+, O+, and OH peaked at about 17 nsec and continued for about 1 msec.

Ohkawa, Yoko; Tamada, Kazunobu; Horisawa, Hideyuki [Department of Aeronautics and Astronautics, Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa, 259-1292 (Japan); Kimura, Itsuro [University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8856 (Japan)

2005-04-27T23:59:59.000Z

16

Accretion Disks and Eruptive Phenomena  

E-Print Network (OSTI)

This paper describes eruptive phenomena in pre-main sequence stars. The eruptions of FU Orionis stars have much in common with outbursts in other accreting systems, such as dwarf novae and some symbiotic stars. These common features are best understood as increases in the rate material flows through an accretion disk. The spectroscopic properties, decay of the light curves, and outflow phenomena suggest that these outbursts arise from thermal instabilities in the disk. Available data and estimates for recurrence times indicate that young stars can accrete much, perhaps all, of their mass in FU Ori accretion events. Future observations can test this notion and place better constraints on the importance of eruptive events in the early life of a low mass star.

Scott J. Kenyon

1999-04-05T23:59:59.000Z

17

NEWTON: Determining Material Degradation  

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Determining Material Degradation Determining Material Degradation Name: Hamish Status: student Grade: 6-8 Location: CA Country: USA Date: Summer 2013 Question: I am working on a science project about photo-degradation of plastic film. My question is how much degraded a plastic film should be to say that it was 100% photo-degraded? The plastic film I am photo-degrading is turning into dust when I touch it, what level of degradation is that? Replies: Hi Hamish, Thanks for the question. You will need to define what you mean by photo-degraded. 100% photo-degraded could be that the film becomes translucent and lets through only blurry images. Or it could mean that the film turns to dust when you touch it. As long as you clearly state in your science project what you mean by 100% photo-degraded, you will be doing a good job.

18

Irradiation-induced phenomena in carbon  

E-Print Network (OSTI)

Chapter 1 Irradiation-induced phenomena in carbon nanotubes To appear in "Chemistry of Carbon@acclab.helsinki.fi 1 #12;2CHAPTER 1. IRRADIATION-INDUCED PHENOMENA IN CARBON NANOTUBES #12;Contents 1 Irradiation-induced phenomena in carbon nanotubes 1 1.1 Introduction

Krasheninnikov, Arkady V.

19

Physical degradation of MEA in PEM fuel cell by on/off operation under nitrogen atmosphere  

Science Journals Connector (OSTI)

The durability of PEMFCs is one of the most important issues for application in automotive vehicles with a repeated start-up and shut-down system. The understanding of degradation phenomena such as causes, mec...

Dongho Seo; Sangsun Park; Yukwon Jeon…

2010-01-01T23:59:59.000Z

20

Data Clustering Reveals Climate Impacts on Local Wind Phenomena  

Science Journals Connector (OSTI)

The authors demonstrate the utility of k-means clustering for identifying relationships between winds at turbine heights and climate oscillations, thereby developing a method suited for predicting the impacts of climate change on wind resources. ...

Andrew Clifton; Julie K. Lundquist

2012-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Turbulent phenomena in protein folding  

Science Journals Connector (OSTI)

Protein folding and hydrodynamic turbulence are two long-standing challenges, in molecular biophysics and fluid dynamics, respectively. The theories of these phenomena have been developed independently and used different formalisms. Here we show that the protein folding flows can be surprisingly similar to turbulent fluid flows. Studying a benchmark model protein (an SH3 domain), we have found that the flows for the slow folding trajectories of the protein, in which a partly formed N- and C-terminal ? sheet hinders the RT loop from attaching to the protein core, have many properties of turbulent flows of a fluid. The flows are analyzed in a three-dimensional (3D) space of collective variables, which are the numbers of native contacts between the terminal ? strands, between the RT loop and the protein core, and the rest of the native contacts. We have found that the flows have fractal nature and are filled with 3D eddies; the latter contain strange attractors, at which the tracer flow paths behave as saddle trajectories. Two regions of the space increment have been observed, in which the flux variations are self-similar with the scaling exponent h=1/3, in surprising agreement with the Kolmogorov inertial range theory of turbulence. In one region, the cascade of protein rearrangements is directed from larger to smaller scales (net folding), and in the other, it is oppositely directed (net unfolding). Folding flows for the fast trajectories are essentially “laminar” and do not have the property of self-similarity. Based on the results of our study, we infer, and support this inference by simulations, that the origin of the similarity between the protein folding and turbulent motion of a fluid is in a cascade mechanism of structural transformations in the systems that underlies these phenomena.

Igor V. Kalgin and Sergei F. Chekmarev

2011-01-31T23:59:59.000Z

22

The Science of Battery Degradation.  

SciTech Connect

This report documents work that was performed under the Laboratory Directed Research and Development project, Science of Battery Degradation. The focus of this work was on the creation of new experimental and theoretical approaches to understand atomistic mechanisms of degradation in battery electrodes that result in loss of electrical energy storage capacity. Several unique approaches were developed during the course of the project, including the invention of a technique based on ultramicrotoming to cross-section commercial scale battery electrodes, the demonstration of scanning transmission x-ray microscopy (STXM) to probe lithium transport mechanisms within Li-ion battery electrodes, the creation of in-situ liquid cells to observe electrochemical reactions in real-time using both transmission electron microscopy (TEM) and STXM, the creation of an in-situ optical cell utilizing Raman spectroscopy and the application of the cell for analyzing redox flow batteries, the invention of an approach for performing ab initio simulation of electrochemical reactions under potential control and its application for the study of electrolyte degradation, and the development of an electrochemical entropy technique combined with x-ray based structural measurements for understanding origins of battery degradation. These approaches led to a number of scientific discoveries. Using STXM we learned that lithium iron phosphate battery cathodes display unexpected behavior during lithiation wherein lithium transport is controlled by nucleation of a lithiated phase, leading to high heterogeneity in lithium content at each particle and a surprising invariance of local current density with the overall electrode charging current. We discovered using in-situ transmission electron microscopy that there is a size limit to lithiation of silicon anode particles above which particle fracture controls electrode degradation. From electrochemical entropy measurements, we discovered that entropy changes little with degradation but the origin of degradation in cathodes is kinetic in nature, i.e. lower rate cycling recovers lost capacity. Finally, our modeling of electrode-electrolyte interfaces revealed that electrolyte degradation may occur by either a single or double electron transfer process depending on thickness of the solid-electrolyte- interphase layer, and this cross-over can be modeled and predicted.

Sullivan, John P; Fenton, Kyle R [Sandia National Laboratories, Albuquerque, NM; El Gabaly Marquez, Farid; Harris, Charles Thomas [Sandia National Laboratories, Albuquerque, NM; Hayden, Carl C.; Hudak, Nicholas [Sandia National Laboratories, Albuquerque, NM; Jungjohann, Katherine Leigh [Sandia National Laboratories, Albuquerque, NM; Kliewer, Christopher Jesse; Leung, Kevin [Sandia National Laboratories, Albuquerque, NM; McDaniel, Anthony H.; Nagasubramanian, Ganesan [Sandia National Laboratories, Albuquerque, NM; Sugar, Joshua Daniel; Talin, Albert Alec; Tenney, Craig M [Sandia National Laboratories, Albuquerque, NM; Zavadil, Kevin R. [Sandia National Laboratories, Albuquerque, NM

2015-01-01T23:59:59.000Z

23

CFD Analysis of Core Bypass Phenomena  

SciTech Connect

The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary

Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

2010-03-01T23:59:59.000Z

24

CFD Analysis of Core Bypass Phenomena  

SciTech Connect

The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

2009-11-01T23:59:59.000Z

25

KINETIC ROUGHENING PHENOMENA, STOCHASTIC GROWTH, DIRECTED  

E-Print Network (OSTI)

KINETIC ROUGHENING PHENOMENA, STOCHASTIC GROWTH, DIRECTED POLYMERS AND ALL THAT Aspects 254 (1995) 215-414 Kinetic roughening phenomena, stochastic growth, directed polymers and all that for the nonlinear term 3.2. Dynamic RG analysis 3.3. A worthy detour: kinetic roughening with conservation law 3

Halpin-Healy, Tim

26

Gaseous isotope separation using solar wind phenomena  

Science Journals Connector (OSTI)

...isotope separation using solar wind phenomena Chia-Gee...essentially the same as that of the solar wind propagation, in which...the author was measuring solar wind parameters under Dr. H. S. Bridge at Massachusetts Institute of Technology in...

Chia-Gee Wang

1980-01-01T23:59:59.000Z

27

Analysis of nuclear reactor instability phenomena  

SciTech Connect

The phenomena known as density-wave instability often occurs in phase change systems, such as boiling water nuclear reactors (BWRS). Our current understanding of density-wave oscillations is in fairly good shape for linear phenomena (eg, the onset of instabilities) but is not very advanced for non-linear phenomena [Lahey and Podowski, 1989]. In particular, limit cycle and chaotic instability modes are not well understood in boiling systems such as current and advanced generation BWRs (eg, SBWR). In particular, the SBWR relies on natural circulation and is thus inherently prone to problems with density-wave instabilities. The purpose of this research is to develop a quantitative understanding of nonlinear nuclear-coupled density-wave instability phenomena in BWRS. This research builds on the work of Achard et al [1985] and Clausse et al [1991] who showed, respectively, that Hopf bifurcations and chaotic oscillations may occur in boiling systems.

Lahey, R.T. Jr.

1993-01-01T23:59:59.000Z

28

Photovoltaic Lifetime & Degradation Science Statistical Pathway Development: Acrylic Degradation  

E-Print Network (OSTI)

Photovoltaic Lifetime & Degradation Science Statistical Pathway Development: Acrylic Degradation, USA ABSTRACT In order to optimize and extend the life of photovoltaics (PV) modules, scientific photovoltaics. The statisti- cally significant relationships were investigated using lifetime and degradation

Rollins, Andrew M.

29

Damage Assessment Technologies for Prognostics and Proactive Management of Materials Degradation  

SciTech Connect

The Nuclear Regulatory Commission has undertaken a program to lay the groundwork for defining proactive actions to manage degradation of materials in light water reactors (LWRs). This paper discusses the U.S. Nuclear Regulatory Commission’s Proactive Management of Materials Degradation (PMMD) program and its application to nuclear power plant structures, systems and components. The PMMD program is examining LWR component materials and the degradation phenomena that affect them. Of particular interest is how such phenomena can be monitored to predict degradation and prevent component failure. Some forms of degradation, such as stress corrosion cracking, are characterized by a long initiation time followed by a rapid growth phase. Monitoring such long-term degradation will require new NDE methods and measurement procedures. A critical analysis of all reactor components is required to determine if new inspection strategies are required to effectively manage slow degradation mechanisms that may lead to component failure. As reactor lifetimes are extended, degradation mechanisms previously considered too long-term to be of consequence (such as concrete and wiring insulation degradation) may become more important. This paper includes a review of techniques with potential for sensing and monitoring degradation in its early stages and will concisely explain the basic principles of PMMD and its relationship to in-service inspection, condition based maintenance, and advanced diagnostics and prognostics.

Bond, Leonard J.; Doctor, Steven R.; Griffin, Jeffrey W.; Hull, Amy; Malik, Shah

2011-02-26T23:59:59.000Z

30

Damage Assessment Technologies for Prognostics and Proactive Management of Materials Degradation  

SciTech Connect

The Nuclear Regulatory Commission has undertaken a program to lay the groundwork for defining proactive actions to manage degradation of materials in light water reactors (LWRs). This paper discusses the U.S. Nuclear Regulatory Commission’s Proactive Management of Materials Degradation (PMMD) program and its application to nuclear power plant structures, systems and components. The PMMD program is examining LWR component materials and the degradation phenomena that affect them. Of particular interest is how such phenomena can be monitored to predict degradation and prevent component failure. Some forms of degradation, including some modes of stress corrosion cracking, are characterized by a long initiation time followed by a rapid growth phase. Monitoring such long-term degradation will require new non-destructive evaluation (NDE) methods and measurement procedures. A critical analysis of all reactor components is required to determine if new inspection strategies are required to effectively manage slow degradation mechanisms that may lead to component failure. As reactor lifetimes are extended, degradation mechanisms previously considered too long-term to be of consequence (such as concrete and wiring insulation degradation) may become more important. This paper includes a review of techniques with potential for sensing and monitoring degradation in its early stages and will concisely explain the basic principles of PMMD and its relationship to in-service inspection, condition based maintenance, and advanced diagnostics and prognostics.

Bond, Leonard J.; Doctor, Steven R.; Griffin, Jeffrey W.; Hull, Amy B.; Malik, Shah

2011-01-01T23:59:59.000Z

31

Oxidative Degradation of Monoethanolamine  

NLE Websites -- All DOE Office Websites (Extended Search)

Oxidative Degradation of Monoethanolamine Oxidative Degradation of Monoethanolamine Susan Chi Gary T. Rochelle* (gtr@che.utexas.edu, 512-471-7230) The University of Texas at Austin Department of Chemical Engineering Austin, Texas 78712 Prepared for presentation at the First National Conference on Carbon Sequestration, Washington, DC, May 14-17, 2001 Abstract Oxidative degradation of monoethanolamine (MEA) was studied under typical absorber condition of 55°C. The rate of evolution of NH 3 , which was indicative of the overall rate of degradation, was measured continuously in a batch system sparged with air. Dissolved iron from 0.0001 mM to 1 mM yields oxidation rates from 0.37 to 2 mM/hr in MEA solutions loaded with 0.4 mole CO 2 / mole MEA. Ethylenediaminetetraacetic acid (EDTA) and N,N-bis(2- hydroxyethyl)glycine effectively decrease the rate of oxidation in the presence of iron by 40 to

32

Sarin Degradation Using Brucite  

Science Journals Connector (OSTI)

Sarin Degradation Using Brucite ... Density Functional Theory (DFT) calculations with periodic boundary conditions were used to investigate a degradation reaction mechanism of the Sarin molecule (isopropyl methylphosphonofluoridate, C4H10FO2P) using the layered hydroxide brucite (Mg(OH)2). ... We computed the adsorption of Sarin on brucite including the infrared vibrational spectrum of gas and adsorbed Sarin, reaction paths, activation energies, and the Gibbs free energy differences (?G). ...

Viviane S. Vaiss; Itamar Borges, Jr.; Alexandre A. Leitão

2011-11-07T23:59:59.000Z

33

2011 CNM Workshop: Emergent Interfacial Phenomena  

NLE Websites -- All DOE Office Websites (Extended Search)

APS/CNM/EMC Users Meeting, May 2-5, 2011 APS/CNM/EMC Users Meeting, May 2-5, 2011 Thematic Workshop B: Emergent Interfacial Phenomena Organizers: Tiffany Santos (formerly CNM, now Hitachi GST), Olle Heinonen (MSD), Paul Fenter (CSE), and Robert Klie (UIC) Sponsors: Argonne Photon Sciences Directorate, Argonne Physical Sciences and Engineering Directorate Heterostructures in which different materials are layered together display a range of emergent phenomena, which can be controlled through effects such as geometric confinement and interface structure. Both of these effects can lead to charge transfer and band structure modification giving rise to novel behavior. Understanding and control of these phenomena require advanced deposition and characterization methods, as well as state-of-the-art modeling

34

Visualizing infrared phenomena with a webcam  

Science Journals Connector (OSTI)

The concept of light (electromagnetic radiation) outside of the visible spectrum is an abstract concept for students in an introductory science class. When students are presented with demonstrations or experiments meant to explore this portion of the spectrum the equipment involved often hides the phenomena. A simple modification to a standard inexpensive web camera (webcam) can take advantage of the sensitivity of the charged-coupled-device (CCD) to the infrared (IR) portion of the spectrum allowing students to visualize many IR phenomena. This note reports how such a modified webcam can be used in lecture demonstrations and laboratory activities to study infrared phenomena including an IR light emitting diode(LED) the IR component of different light sources IR spectroscopy and blackbody radiation. As a final example the modified camera can be employed to view the charcoal under-drawing of a “painting” created for this paper and used in our classroom demonstrations.

N. A. Gross; M. Hersek; A. Bansil

2005-01-01T23:59:59.000Z

35

Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity.  

E-Print Network (OSTI)

Coulomb Friction Viscous Friction Stribeck Friction Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity. Static Friction Model: Friction force opposes the direction of motion when the sliding velocity is zero. Coulomb Friction Model: Friction force

Simpkins, Alex

36

Dissipative phenomena in quark-gluon plasmas  

SciTech Connect

Transport coefficients of small-chemical-potential quark-gluon plasmas are estimated and dissipative corrections to the scaling hydrodynamic equations for ultrarelativistic nuclear collisions are studied. The absence of heat-conduction phenomena is clarified. Lower and upper bounds on the shear-viscosity coefficient are derived. QCD phenomenology is used to estimate effects of color-electric and -magnetic shielding, and nonperturbative antiscreening. Bulk viscosity associated with the plasma-to-hadron transition is estimated within the relaxation-time approximation. Finally, effects of dissipative phenomena on the relation between initial energy density and final rapidity density are estimated.

Danielewicz, P.; Gyulassy, M.

1985-01-01T23:59:59.000Z

37

Drift Degradation Analysis  

SciTech Connect

Degradation of underground openings as a function of time is a natural and expected occurrence for any subsurface excavation. Over time, changes occur to both the stress condition and the strength of the rock mass due to several interacting factors. Once the factors contributing to degradation are characterized, the effects of drift degradation can typically be mitigated through appropriate design and maintenance of the ground support system. However, for the emplacement drifts of the geologic repository at Yucca Mountain, it is necessary to characterize drift degradation over a 10,000-year period, which is well beyond the functional period of the ground support system. This document provides an analysis of the amount of drift degradation anticipated in repository emplacement drifts for discrete events and time increments extending throughout the 10,000-year regulatory period for postclosure performance. This revision of the drift degradation analysis was developed to support the license application and fulfill specific agreement items between the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE). The earlier versions of ''Drift Degradation Analysis'' (BSC 2001 [DIRS 156304]) relied primarily on the DRKBA numerical code, which provides for a probabilistic key-block assessment based on realistic fracture patterns determined from field mapping in the Exploratory Studies Facility (ESF) at Yucca Mountain. A key block is defined as a critical block in the surrounding rock mass of an excavation, which is removable and oriented in an unsafe manner such that it is likely to move into an opening unless support is provided. However, the use of the DRKBA code to determine potential rockfall data at the repository horizon during the postclosure period has several limitations: (1) The DRKBA code cannot explicitly apply dynamic loads due to seismic ground motion. (2) The DRKBA code cannot explicitly apply loads due to thermal stress. (3) The DRKBA code, which determines structurally controlled key-block failure, is not applicable for stress-controlled failure in the lithophysal units. To address these limitations, additional numerical codes have been included that can explicitly apply seismic and thermal loads, providing significant improvements to the analysis of drift degradation and extending the validity of drift degradation models.

D. Kicker

2004-09-16T23:59:59.000Z

38

Computationally efficient algorithms for modelling thermal degradation and spiking phenomena in polymeric materials  

E-Print Network (OSTI)

resistance are the key factors that determine a wide spread success of these materials (Flipsen et al., 1996 in polymeric materials R.V.N. Melnik * Faculty of Science and Engineering, Mads Clausen Institute, University are interested in one such problem, namely in the modelling of curing dynamics of polymeric materials

Melnik, Roderick

39

Degradation phenomena and design principles for stable and active Pt/C fuel cell catalysts.  

E-Print Network (OSTI)

??Stabile und aktive Elektrodenmaterialien sind entscheidend für moderne elektrochemische Energiewandler wie Brennstoffzellen. Diese Arbeit untersucht die Aktivität und insbesondere Stabilität von Pt/ C Brennstoffzellenkatalysatoren. In… (more)

Meier, Josef Christian

2013-01-01T23:59:59.000Z

40

ASSESSMENTOF BURNING-PLASMA PHENOMENA COMPACTIGNITION TOKAMAK  

E-Print Network (OSTI)

Report+ on ASSESSMENTOF BURNING-PLASMA PHENOMENA . in a COMPACTIGNITION TOKAMAK presented-coil tokamak configurations that would achieve ignition under presently accepted scaling laws. Studies the extent to which these compact tokamak ignition experiments can resolve the technical issue of under

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Photo-Galvano-Mechanical Phenomena in Nanotubes  

E-Print Network (OSTI)

Photo-Galvano-Mechanical Phenomena in Nanotubes Petr KraI\\ E. J. Mele2 , David Tomanek3 and Moshe elec- trical "ballistic current". The photo-currents can be generated even in centrosym- metric be also generated in semiconductor nanotubes or in higher bands of metallic nanotubes [2]. The photo

42

Quantization makes Relativity Compatible with Superluminal Phenomena  

E-Print Network (OSTI)

By relativity we show that, although the superluminal motion of classical particles is forbidden, the superluminal transportation of quanta of any massive matter field is possible. Exact theoretical derivation and precise numerical computation are presented. To search the superluminal phenomena is therefore still meaningful.

Qi-Ren Zhang

2012-02-28T23:59:59.000Z

43

Resonant phenomena in slowly perturbed elliptic billiards  

E-Print Network (OSTI)

We consider an elliptic billiard whose shape slowly changes. During slow evolution of the billiard certain resonance conditions can be fulfilled. We study the phenomena of capture into a resonance and scattering on resonances which lead to the destruction of the adiabatic invariance in the system.

A. P. Itin; A. I. Neishtadt

2005-12-11T23:59:59.000Z

44

Degradation Of Cementitious Materials Associated With Saltstone Disposal Units  

SciTech Connect

The Saltstone facilities at the DOE Savannah River Site (SRS) stabilize and dispose of low-level radioactive salt solution originating from liquid waste storage tanks at the site. The Saltstone Production Facility (SPF) receives treated salt solution and mixes the aqueous waste with dry cement, blast furnace slag, and fly ash to form a grout slurry which is mechanically pumped into concrete disposal cells that compose the Saltstone Disposal Facility (SDF). The solidified grout is termed “saltstone”. Cementitious materials play a prominent role in the design and long-term performance of the SDF. The saltstone grout exhibits low permeability and diffusivity, and thus represents a physical barrier to waste release. The waste form is also reducing, which creates a chemical barrier to waste release for certain key radionuclides, notably Tc-99. Similarly, the concrete shell of an SDF disposal unit (SDU) represents an additional physical and chemical barrier to radionuclide release to the environment. Together the waste form and the SDU compose a robust containment structure at the time of facility closure. However, the physical and chemical state of cementitious materials will evolve over time through a variety of phenomena, leading to degraded barrier performance over Performance Assessment (PA) timescales of thousands to tens of thousands of years. Previous studies of cementitious material degradation in the context of low-level waste disposal have identified sulfate attack, carbonation influenced steel corrosion, and decalcification (primary constituent leaching) as the primary chemical degradation phenomena of most relevance to SRS exposure conditions. In this study, degradation time scales for each of these three degradation phenomena are estimated for saltstone and concrete associated with each SDU type under conservative, nominal, and best estimate assumptions. The nominal value (NV) is an intermediate result that is more probable than the conservative estimate (CE) and more defensible than the best estimate (BE). The combined effects of multiple phenomena are then considered to determine the most limiting degradation time scale for each cementitious material. Degradation times are estimated using a combination of analytic solutions from literature and numerical simulation codes provided through the DOE Cementitious Barriers Partnership (CBP) Software Toolbox (http://cementbarriers.org). For the SDU 2 design, the roof, wall, and floor components are projected to become fully degraded under Nominal conditions at 3866, 923, and 1413 years, respectively. For SDU 4 the roof and floor are estimated to be fully degraded under Nominal conditions after 1137 and 1407 years, respectively; the wall is assumed to be fully degraded at time zero in the most recent PA simulations. Degradation of these concrete barriers generally occurs from combined sulfate attack and corrosion of embedded steel following carbonation. Saltstone is projected to degrade very slowly by decalcification, with complete degradation occurring in excess of 200,000 years for any SDU type. Complete results are provided.

Flach, G. P; Smith, F. G. III

2013-03-19T23:59:59.000Z

45

Why sequence Xylan degraders?  

NLE Websites -- All DOE Office Websites (Extended Search)

Xylan degraders? Xylan degraders? Producing biofuels from lignocellulosic biomass is being investigated as a possible energy source to reduce the United States' dependence on foreign oil. One challenge researchers face is that plant cell walls are complex structures composed of cellulose, hemicellulose, lignin, pectin, and protein. Current methods of breaking down these plant cell walls are not cheap, making ethanol production expensive and not a realistic competitor to petroleum. The major component of hemicellulose is xylan, a five carbon sugar. Enzymes or bacteria could be used to break up the xylan in plant material, making cellulose more accessible to cellulases. The xylan can also be used to produce xylose, from which ethanol can be produced. In sequencing five xylan degrading microbes, researchers hope to identify protein sequences of

46

Self-degradable Temporary Cementitious  

Energy.gov (U.S. Department of Energy (DOE))

Self-degradable Temporary Cementitious presentation at the April 2013 peer review meeting held in Denver, Colorado.

47

Studies of Novel Quantum Phenomena in Ruthenates  

SciTech Connect

Strongly correlated oxides have been the subject of intense study in contemporary condensed matter physics, and perovskite ruthenates (Sr,Ca)n+1RunO3n+1 have become a new focus in this field. One of important characteristics of ruthenates is that both lattice and orbital degrees of freedom are active and are strongly coupled to charge and spin degrees of freedom. Such a complex interplay of multiple degrees of freedom causes the properties of ruthenates to exhibit a gigantic response to external stimuli under certain circumstances. Magnetic field, pressure, and chemical composition all have been demonstrated to be effective in inducing electronic/magnetic phase transitions in ruthenates. Therefore, ruthenates are ideal candidates for searching for novel quantum phenomena through controlling external parameters. The objective of this project is to search for novel quantum phenomena in ruthenate materials using high-quality single crystals grown by the floating-zone technique, and investigate the underlying physics. The following summarizes our accomplishments. We have focused on trilayered Sr4Ru3O10 and bilayered (Ca1-xSrx)3Ru2O7. We have succeeded in growing high-quality single crystals of these materials using the floating-zone technique and performed systematic studies on their electronic and magnetic properties through a variety of measurements, including resistivity, Hall coefficient, angle-resolved magnetoresistivity, Hall probe microscopy, and specific heat. We have also studied microscopic magnetic properties for some of these materials using neutron scattering in collaboration with Los Alamos National Laboratory. We have observed a number of unusual exotic quantum phenomena through these studies, such as an orbital selective metamagnetic transition, bulk spin valve effect, and a heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio. Our work has also revealed underlying physics of these exotic phenomena. Exotic phenomena of correlated electron has been among central topics of contempary condensed matter physics. Ultrfast phase transitions accompanied by switching of conductivity or magnetization in stronly correlated materials are believed to be promising in developing next generation of transistors. Our work on layered ruthenates has remarkably advanced our understanding of how the exotic phenomena of correlated electrons is governed by the complex interplay between charge, spin, lattice and orbital degrees of freedom. In addition to studies on ruthenates, we have also expanded our research to the emerging field of Fe-based superconductors, focusing on the iron chalcogenide Fe1+y(Te1-xSex) superconductor system. We first studied the superconductivity of this alloy system following the discovery of superconductivity in FeSe using polycrystalline samples. Later, we successfuly grew high-quality single crystals of these materials. Using these single crystals, we have determined the magnetic structure of the parent compound Fe1+yTe, observed spin resonance of superconducting state in optimally doped samples, and established a phase diagram. Our work has produced an important impact in this burgeoning field. The PI presented an invited talk on this topic at APS March meeting in 2010. We have published 19 papers in these two areas (one in Nature materials, five in Physical Review Letters, and nine in Physical Review B) and submitted two (see the list of publications attached below).

Mao, Zhiqiang

2011-04-08T23:59:59.000Z

48

Advances in modelling of condensation phenomena  

SciTech Connect

The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described.

Liu, W.S.; Zaltsgendler, E. [Ontario Hydro Nuclear, Toronto (Canada); Hanna, B. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

1997-07-01T23:59:59.000Z

49

BEAM COUPLING PHENOMENA IN FAST KICKER SYSTEMS.  

SciTech Connect

Beam coupling phenomena have been observed in most fast kicker systems through out Brookhaven Collider-Accelerator complex. With ever-higher beam intensity, the signature of the beam becomes increasingly recognizable. The beam coupling at high intensity produced additional heat dissipation in high voltage modulator, thyratron grids, thyratron driver circuit sufficient to damage some components, and causes trigger instability. In this paper, we will present our observations, basic coupling mode analysis, relevance to the magnet structures, issues related to the existing high voltage modulators, and considerations of the future design of the fast kicker systems.

ZHANG,W.; AHRENS,L.A.; GLENN,J.; SANDBERG,J.; TSOUPAS,N.

2001-06-18T23:59:59.000Z

50

Outdoor PV Degradation Comparison  

SciTech Connect

As photovoltaic (PV) penetration of the power grid increases, it becomes vital to know how decreased power output; may affect cost over time. In order to predict power delivery, the decline or degradation rates must be determined; accurately. At the Performance and Energy Rating Testbed (PERT) at the Outdoor Test Facility (OTF) at the; National Renewable Energy Laboratory (NREL) more than 40 modules from more than 10 different manufacturers; were compared for their long-term outdoor stability. Because it can accommodate a large variety of modules in a; limited footprint the PERT system is ideally suited to compare modules side-by-side under the same conditions.

Jordan, D. C.; Smith, R. M.; Osterwald, C. R.; Gelak, E.; Kurtz, S. R.

2011-02-01T23:59:59.000Z

51

Evidence supporting dissimilatory and assimilatory lignin degradation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1. Evidence supporting dissimilatory and assimilatory lignin degradation in...

52

Magneto-photonic phenomena at terahertz frequencies  

E-Print Network (OSTI)

Magneto-terahertz phenomena are the main focus of the thesis. This work started as supporting research for the science of an X-ray laser (SwissFEL). X-ray lasers have recently drawn great attention as an unprecedented tool for scientific research on the ultrafast scale..... To answer this fundamental question, we performed original numerical simulations using a coupled Landau- Lifshitz-Gilbert Maxwell model. ... Those requirements were the motivations for the experiments performed in the second part of the thesis. To shape the terahertz pulses, .... Regarding the field intensities, we followed two approaches. The first deals with field enhancement in nanoslits arrays. We designed a subwavelength structure characterized by simultaneous high field enhancement and high transmission at terahertz frequencies to suit nonlinear sources. The second approach depended on up-scaling the generation from laser-induced plasma by increasing the pump wavelengths. Numerical calculations have also brought to our attention the ...

Shalaby, Mostafa

2014-01-01T23:59:59.000Z

53

Shock phenomena in baryonless strongly interacting matter  

SciTech Connect

Shock phenomena associated with the quark-to-hadron matter phase transition are studied using the concept of adiabats. To allow for an analysis of a medium with vanishing baryon density, the shock and Poisson adiabats are formulated in terms of hydrodynamic fluxes, rather than only thermodynamic variables. The bag-model equation of state is used to describe the phase transition. It is shown that deflagrations from the quark phase above the critical temperature and strong detonations from the supercooled quark phase to the superheated hadron phase are unlikely. Instead the possibility of weak condensation detonations from the supercooled quark phase to a mixed phase is indicated. Strong detonations can occur if the latent energy density of the phase transition is small compared to the energy density of the hadron gas. Simple properties of the adiabats and of the equation of state are employed to derive several analytic results.

Danielewicz, P.; Ruuskanen, P.V.

1987-01-01T23:59:59.000Z

54

On the effect of gas diffusion layers hydrophobicity on direct methanol fuel cell performance and degradation  

Science Journals Connector (OSTI)

Abstract Degradation and mass transport phenomena management are two of the main issues hindering direct methanol fuel cell commercialization. Water and methanol crossover through the membrane, regulated by both anode and cathode gas diffusion layers hydrophobic properties, is widely studied in the literature, while the effect of mass transport phenomena evolution on the direct methanol fuel cell degradation has not been investigated yet. This work aims to present a combined experimental and modeling analysis on the effect of the gas diffusion layers hydrophobicity on DMFC degradation, through the comparison of performance characterization and degradation tests of two different fuel cells. In one of them, the lower diffusion layer hydrophobicity and the absence of anode microporous layer determines the onset of cathode flooding, negatively affecting performance and degradation. However, the cathode surface area loss is similar between the two fuel cells, meaning that flooding does not involve modifications in cathode permanent degradation mechanisms, but it mainly determines the amplification of the cathode surface area loss effects.

F. Bresciani; C. Rabissi; M. Zago; R. Marchesi; A. Casalegno

2015-01-01T23:59:59.000Z

55

Absorber coatings' degradation  

SciTech Connect

This report is intended to document some of the Los Alamos efforts that have been carried out under the Department of Energy (DOE) Active Heating and Cooling Materials Reliability, Maintainability, and Exposure Testing program. Funding for these activities is obtained directly from DOE although they represent a variety of projects and coordination with other agencies. Major limitations to the use of solar energy are the uncertain reliability and lifetimes of solar systems. This program is aimed at determining material operating limitations, durabilities, and failure modes such that materials improvements can be made and lifetimes can be extended. Although many active and passive materials and systems are being studied at Los Alamos, this paper will concentrate on absorber coatings and degradation of these coatings.

Moore, S.W.

1984-01-01T23:59:59.000Z

56

CRITICAL BEHAVIOR OF INTERFACES: ROUGHENING AND WETTING PHENOMENA  

E-Print Network (OSTI)

The critical behavior of interfaces is discussed from a theoretical point of view. Two classes of critical phenomena will be considered: (i) Roughening phenomena related to changes in the interfacial morphology; and (ii) Wetting phenomena related to changes in the interfacial structure. In two dimensions, the critical behavior can be determined exactly for a variety of models. As a result, one obtains different universality classes depending on the nature of the intermolecular forces. 1.

unknown authors

57

Pantex Facility 10-Year Natural Phenomena Flood Hazard Analysis  

Energy.gov (U.S. Department of Energy (DOE))

Pantex Facility 10-Year Natural Phenomena Flood Hazard Analysis Presented by B&W Technical Services, Pantex and Pro2Serve October, 2011

58

MATERIALS, INTERFACES, AND ELECTROCHEMICAL PHENOMENA Hydrophilic Zeolite Coatings for Improved  

E-Print Network (OSTI)

MATERIALS, INTERFACES, AND ELECTROCHEMICAL PHENOMENA Hydrophilic Zeolite Coatings for Improved Heat the system, decreases the oper- ation noise and the pumping cost. Another major consideration for a heat

Aguilar, Guillermo

59

October 2014 Natural Phenomena Hazards (NPH) Meeting - Tuesday...  

Office of Environmental Management (EM)

Seismic Hazard Analysis For Nuclear Facilities At The Hanford Site, Eastern Washington, USA Natural Phenomena Hazards DOE-STD 1020-2012 & DOE Handbook A Probabilistic Approach to...

60

On the Nature of Quantum Phenomena  

E-Print Network (OSTI)

It is shown that a coherent understanding of all quantized phenomena, including those governed by unitary evolution equations as well as those related to irreversible quantum measurements, can be achieved in a scenario of successive nonequilibrium phase transitions, with the lowest hierarchy of these phase transitions occurring in a ``resonant cavity'' formed by the entire matter and energy content of the universe. In this formalism, the physical laws themselves are resonantly-selected and ordered in the universe cavity in a hierarchical manner, and the values of fundamental constants are determined through a Generalized Mach's Principle. The existence of a preferred reference frame in this scenario is shown to be consistent with the relational nature of the origin of physical laws. Covariant unitary evolution is shown to connect smoothly with the reduction of wavefunction in the preferred frame during quantum measurement. The superluminal nature of quantum processes in the lowest hierarchy coexists with the universal speed limit obeyed by processes in higher hierarchies. A natural quantum-to-classical transition is also obtained which is stable against the diffusive tendency of the unitary quantum evolution processes. In this formalism a realistic quasi-classical ontology is established for the foundations of quantum mechanics.

Xiaolei Zhang

2007-12-28T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Rotary kilns - transport phenomena and transport processes  

SciTech Connect

Rotary kilns and rotating industrial drying ovens are used for a wide variety of applications including processing raw minerals and feedstocks as well as heat-treating hazardous wastes. They are particularly critical in the manufacture of Portland cement. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and excessive, high fuel costs. This book treats all engineering aspects of rotary kilns, including thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. Chapter 1: The Rotary Kiln Evolution and Phenomenon Chapter 2: Basic Description of Rotary Kiln Operation Chapter 3: Freeboard Aerodynamic Phenomena Chapter 4: Granular Flows in Rotary Kilns Chapter 5: Mixing and Segregation Chapter 6: Combustion and Flame - includes section on types of fuels used in rotary kilns, coal types, ranking and analysis, petroleum coke combustion, scrap tire combustion, pulverized fuel (coal/coke) firing in kilns, pulverized fuel delivery and firing systems. Chapter 7: Freeboard Heat Transfer Chapter 8: Heat Transfer Processes in the Rotary Kiln Bed Chapter 9: Mass and Energy Balance Chapter 10: Rotary Kiln Minerals Process Applications.

Boateng, A.

2008-01-15T23:59:59.000Z

62

Natural Phenomena Hazards (NPH) Meeting- October 2011  

Energy.gov (U.S. Department of Energy (DOE))

On October 25-26, 2011, the DOE Chief of Nuclear Safety (CNS) hosted a Natural Phenomena Hazards (NPH) working meeting in Germantown, Maryland. The meeting brought together approximately 80 experts involved in the characterization of, and mitigation against, natural hazards that can impact critical facilities. The meeting was valuable for sharing and discussing research in NPH analysis and mitigation, as well as best practices and lessons learned. Representatives from DOE Headquarters and site offices, four National Laboratories, the Defense Nuclear Facilities Safety Board, the U.S. Nuclear Regulatory Commission (NRC), and several DOE prime contractors and other private sector firms participated in the meeting. The meeting featured thirty five discussion topics over the two days. Presentation slides from most of these topics are available here, as well as papers on several topics from those speakers who chose to provide them. Questions about the NPH meeting can be directed to Dr. Steve McDuffie of the CNS staff at 509-373-6766, or stephen.mcduffie@rl.doe.gov.

63

Durability Improvements Through Degradation Mechanism Studies  

E-Print Network (OSTI)

Durability Improvements Through Degradation Mechanism Studies Fuel Cell Technologies 2009 Kickoff of fuel cell component degradation · Quantify the influence of inter-relational operating environment between different fuel cell components · Degradation measurements of components and component interfaces

64

Performance Degradation of LSCF Cathodes  

SciTech Connect

This final report summarizes the progress made during the October 1, 2008 - September 30, 2013 period under Cooperative Agreement DE-NT0004109 for the U. S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled “Performance Degradation of LSCF Cathodes”. The primary objective of this program is to develop a performance degradation mitigation path for high performing, cost-effective solid oxide fuel cells (SOFCs). Strategies to mitigate performance degradation are developed and implemented. In addition, thermal spray manufacturing of SOFCs is explored. Combined, this work establishes a basis for cost-effective SOFC cells.

Alinger, Matthew

2013-09-30T23:59:59.000Z

65

DOE Standard 1020 - Natural Phenomena Hazard analysis and Design Criteria  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE Standard 1020 - Natural Phenomena Hazard analysis and Design DOE Standard 1020 - Natural Phenomena Hazard analysis and Design Criteria for DOE Facilities DOE Standard 1020 - Natural Phenomena Hazard analysis and Design Criteria for DOE Facilities Department of Energy (DOE) Standard (STD)-1020-2012, Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities, provides criteria and guidance for the analysis and design of facility structures, systems, and components (SSCs) that are necessary to implement the requirements of DOE Order (O) 420.1C, Facility Safety, and to ensure that the SSCs will be able to effectively perform their intended safety functions under the effects of natural phenomena hazards (NPHs). This Standard also provides criteria and guidance for the use of industry building codes and voluntary

66

CRAD, Review of Preparedness for Severe Natural Phenomena Events - August  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Preparedness for Severe Natural Phenomena Events - Preparedness for Severe Natural Phenomena Events - August 21, 2012 CRAD, Review of Preparedness for Severe Natural Phenomena Events - August 21, 2012 August 21, 2012 Review of Preparedness for Severe Natural Phenomena Events at the Savannah River Site Tritium Facility (HSS CRAD 45-54) The focus of this CRAD is on evaluating processes for identifying emergency response capabilities and maintaining them in a state of readiness in case a severe natural phenomena event occurs that exceeds the design basis of the Savannah River Site (SRS) tritium facility. This CRAD is intended to ensure that the NNSA SRS Site Office (SRSO) plans, procedures, and performance identified in DOE Order 151.lC, Comprehensive Emergency Management System, and the Contractors Requirements Document (CRD)

67

Contributions to accelerated destructive degradation test planning.  

E-Print Network (OSTI)

??Many failure mechanisms can be traced to underlying degradation processes. Degradation eventually leads to a weakness that can cause a failure for products. When it… (more)

Shi, Ying

2010-01-01T23:59:59.000Z

68

Seawater degradation of polymeric composites  

E-Print Network (OSTI)

SEAWATER DEGRADATION OF POLYMERIC COMPOSITES A Thesis by TIMOTHY SEAN GRANT Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1991 Major... Subject: Mechanical Engineering SEAWATER DEGRADATION OF POLYMERIC COMPOSITES A Thesis by TIMOTHY SEAN GRANT Approved as to style and content by: Walter L. Bradley (Chair of mmittee) lan Letton (Member) arry ogan (Member) r John Whitcomb...

Grant, Timothy Sean

1991-01-01T23:59:59.000Z

69

Natural Phenomena Hazards (NPH) Workshop | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Natural Phenomena Hazards (NPH) Workshop Natural Phenomena Hazards (NPH) Workshop Natural Phenomena Hazards (NPH) Workshop The Energy Department Natural Phenomena Hazards (NPH) Workshop, sponsored by the Chief of Nuclear Safety and the Chief of Defense Nuclear Safety, was held October 25-26, 2011, in Germantown, Maryland. The workshop brought together approximately 80 experts involved in the characterization of, and mitigation against, natural hazards that can impact nuclear facilities. The workshop featured twenty presentations as well as a breakout session devoted to discussing the status of the commonly used structural analysis code SASSI, a System for Analysis of Soil-Structure Interaction. A Method for Evaluating Fire after Earthquake Scenarios for Single Buildings_1.pdf Addressing Uncertainties in Design Inputs - A Case Study of Probabilistic

70

Natural Phenomena Hazards (NPH) Workshop | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Natural Phenomena Hazards (NPH) Workshop Natural Phenomena Hazards (NPH) Workshop Natural Phenomena Hazards (NPH) Workshop The Energy Department Natural Phenomena Hazards (NPH) Workshop, sponsored by the Chief of Nuclear Safety and the Chief of Defense Nuclear Safety, was held October 25-26, 2011, in Germantown, Maryland. The workshop brought together approximately 80 experts involved in the characterization of, and mitigation against, natural hazards that can impact nuclear facilities. The workshop featured twenty presentations as well as a breakout session devoted to discussing the status of the commonly used structural analysis code SASSI, a System for Analysis of Soil-Structure Interaction. A Method for Evaluating Fire after Earthquake Scenarios for Single Buildings_1.pdf Addressing Uncertainties in Design Inputs - A Case Study of Probabilistic

71

Simulation and design optimization for linear wave phenomena on metamaterials  

E-Print Network (OSTI)

Periodicity can change materials properties in a very unintuitive way. Many wave propagation phenomena, such as waveguides, light bending structures or frequency filters can be modeled through finite periodic structures ...

Saà-Seoane, Joel

2011-01-01T23:59:59.000Z

72

Lattice Boltzmann Simulations for Microfluidics and Mesoscale Phenomena  

Science Journals Connector (OSTI)

The Lattice Boltzmann Equation (LBE) method is described for...2 bubbly flow demonstrate its capability in simulating multiphysics phenomena that are challenging for conventional Navier-Stokes based techniques.

E. Monaco; K. H. Luo; R. S. Qin

2009-01-01T23:59:59.000Z

73

Analysis of nuclear reactor instability phenomena. Progress report  

SciTech Connect

The phenomena known as density-wave instability often occurs in phase change systems, such as boiling water nuclear reactors (BWRS). Our current understanding of density-wave oscillations is in fairly good shape for linear phenomena (eg, the onset of instabilities) but is not very advanced for non-linear phenomena [Lahey and Podowski, 1989]. In particular, limit cycle and chaotic instability modes are not well understood in boiling systems such as current and advanced generation BWRs (eg, SBWR). In particular, the SBWR relies on natural circulation and is thus inherently prone to problems with density-wave instabilities. The purpose of this research is to develop a quantitative understanding of nonlinear nuclear-coupled density-wave instability phenomena in BWRS. This research builds on the work of Achard et al [1985] and Clausse et al [1991] who showed, respectively, that Hopf bifurcations and chaotic oscillations may occur in boiling systems.

Lahey, R.T. Jr.

1993-03-01T23:59:59.000Z

74

High speed imaging of transient non-Newtonian fluid phenomena  

E-Print Network (OSTI)

In this thesis, I investigate the utility of high speed imaging for gaining scientific insight into the nature of short-duration transient fluid phenomena, specifically applied to the Kaye effect. The Kaye effect, noted ...

Gallup, Benjamin H. (Benjamin Hodsdon), 1982-

2004-01-01T23:59:59.000Z

75

Novel applications of Maxwell's equations to quantum and thermal phenomena  

E-Print Network (OSTI)

This thesis is concerned with the extension of Maxwell's equations to situations far removed from standard electromagnetism, in order to discover novel phenomena. We discuss our contributions to the efforts to describe ...

McCauley, Alexander P. (Alexander Patrick)

2011-01-01T23:59:59.000Z

76

Renewal sequences, disordered potentials, and pinning phenomena  

E-Print Network (OSTI)

We give an overview of the state of the art of the analysis of disordered models of pinning on a defect line. This class of models includes a number of well known and much studied systems (like polymer pinning on a defect line, wetting of interfaces on a disordered substrate and the Poland-Scheraga model of DNA denaturation). A remarkable aspect is that, in absence of disorder, all the models in this class are exactly solvable and they display a localization-delocalization transition that one understands in full detail. Moreover the behavior of such systems near criticality is controlled by a parameter and one observes, by tuning the parameter, the full spectrum of critical behaviors, ranging from first order to infinite order transitions. This is therefore an ideal set-up in which to address the question of the effect of disorder on the phase transition,notably on critical properties. We will review recent results that show that the physical prediction that goes under the name of Harris criterion is indeed fully correct for pinning models. Beyond summarizing the results, we will sketch most of the arguments of proof.

Giambattista Giacomin

2008-07-27T23:59:59.000Z

77

Clad Degradation - FEPs Screening Arguments  

SciTech Connect

The purpose of this report is to document the screening of the cladding degradation features, events, and processes (FEPs) for commercial spent nuclear fuel (CSNF). This report also addresses the effect of some FEPs on both the cladding and the CSNF, DSNF, and HLW waste forms where it was considered appropriate to address the effects on both materials together. This report summarizes the work of others to screen clad degradation FEPs in a manner consistent with, and used in, the Total System Performance Assessment-License Application (TSPA-LA). This document was prepared according to ''Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA'' (BSC 2004a [DIRS 167796]).

E. Siegmann

2004-03-17T23:59:59.000Z

78

Degradable Polyethylene: Fantasy or Reality  

Science Journals Connector (OSTI)

Degradable polyethylene, which would enter the eco-cycle harmlessly through biodegradation would be a desirable solution to this problem. ... This article also outlines important questions, particularly in terms of time scale of complete degradation, environmental fate of the polymer residues, and possible accumulation of toxins, the answers to which need to be established prior to accepting these polymers as environmentally benign alternatives to their nondegradable equivalents. ... It appears from the existing literature that our search for biodegradable polyethylene has not yet been realized. ...

Prasun K. Roy; Minna Hakkarainen; Indra K. Varma; Ann-Christine Albertsson

2011-04-15T23:59:59.000Z

79

Local Cohomology  

E-Print Network (OSTI)

ian there is t(a) 2N :(. p. a)t(a) ...... ian local A-algebra (B;n) over a Noetherian local ring (A;m) such that for ...... Since in the above displayed sequence= R1,.

80

DEGRADATION ISSUES IN SOLID OXIDE CELLS DURING HIGH TEMPERATURE ELECTROLYSIS  

SciTech Connect

Idaho National Laboratory (INL) is performing high-temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells (SOECs). The project goals are to address the technical and degradation issues associated with the SOECs. This paper provides a summary of various ongoing INL and INL sponsored activities aimed at addressing SOEC degradation. These activities include stack testing, post-test examination, degradation modeling, and a list of issues that need to be addressed in future. Major degradation issues relating to solid oxide fuel cells (SOFC) are relatively better understood than those for SOECs. Some of the degradation mechanisms in SOFCs include contact problems between adjacent cell components, microstructural deterioration (coarsening) of the porous electrodes, and blocking of the reaction sites within the electrodes. Contact problems include delamination of an electrode from the electrolyte, growth of a poorly (electronically) conducting oxide layer between the metallic interconnect plates and the electrodes, and lack of contact between the interconnect and the electrode. INL’s test results on high temperature electrolysis (HTE) using solid oxide cells do not provide a clear evidence whether different events lead to similar or drastically different electrochemical degradation mechanisms. Post-test examination of the solid oxide electrolysis cells showed that the hydrogen electrode and interconnect get partially oxidized and become non-conductive. This is most likely caused by the hydrogen stream composition and flow rate during cool down. The oxygen electrode side of the stacks seemed to be responsible for the observed degradation due to large areas of electrode delamination. Based on the oxygen electrode appearance, the degradation of these stacks was largely controlled by the oxygen electrode delamination rate. University of Utah (Virkar) has developed a SOEC model based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. This model is under continued development. It shows that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, within the electrolyte. The chemical potential within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just under the oxygen electrode (anode)/electrolyte interface, leading to electrode delamination. This theory is being further refined and tested by introducing some electronic conduction in the electrolyte.

J. E. O'Brien; C. M. Stoots; V. I. Sharma; B. Yildiz; A. V. Virkar

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

DEGRADATION ISSUES IN SOLID OXIDE CELLS DURING HIGH TEMPERATURE ELECTROLYSIS  

SciTech Connect

Idaho National Laboratory (INL) is performing high-temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells (SOECs). The project goals are to address the technical and degradation issues associated with the SOECs. This paper provides a summary of various ongoing INL and INL sponsored activities aimed at addressing SOEC degradation. These activities include stack testing, post-test examination, degradation modeling, and a list of issues that need to be addressed in future. Major degradation issues relating to solid oxide fuel cells (SOFC) are relatively better understood than those for SOECs. Some of the degradation mechanisms in SOFCs include contact problems between adjacent cell components, microstructural deterioration (coarsening) of the porous electrodes, and blocking of the reaction sites within the electrodes. Contact problems include delamination of an electrode from the electrolyte, growth of a poorly (electronically) conducting oxide layer between the metallic interconnect plates and the electrodes, and lack of contact between the interconnect and the electrode. INL's test results on high temperature electrolysis (HTE) using solid oxide cells do not provide a clear evidence whether different events lead to similar or drastically different electrochemical degradation mechanisms. Post-test examination of the solid oxide electrolysis cells showed that the hydrogen electrode and interconnect get partially oxidized and become non-conductive. This is most likely caused by the hydrogen stream composition and flow rate during cool down. The oxygen electrode side of the stacks seemed to be responsible for the observed degradation due to large areas of electrode delamination. Based on the oxygen electrode appearance, the degradation of these stacks was largely controlled by the oxygen electrode delamination rate. University of Utah (Virkar) has developed a SOEC model based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. This model is under continued development. It shows that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, within the electrolyte. The chemical potential within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just under the oxygen electrode (anode)/electrolyte interface, leading to electrode delamination. This theory is being further refined and tested by introducing some electronic conduction in the electrolyte.

M. S. Sohal; J. E. O'Brien; C. M. Stoots; V. I. Sharma; B. Yildiz; A. Virkar

2012-02-01T23:59:59.000Z

82

Turbine Surface Degradation with Service and Its Effects on Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

Peer Review Workshop III Peer Review Workshop III 18-20 October 2005 Jeffrey Bons BYU Z.J. Wang (3-D) Tom Shih (2-D) Iowa State University IOWA STATE UNIVERSITY Aerospace Engineering Turbine Surface Degradation with Service and Its Effects on Performance - 2-D/3-D CFD Simulations of Rough Surfaces- * Perform detailed CFD simulations to generate understanding of flow and heat transfer phenomena over rough surfaces. * Use understanding generated to develop engineering models to predict heat transfer and friction on rough surfaces. Objectives IOWA STATE UNIVERSITY Aerospace Engineering Accomplishments * Performed 2-D and 3-D CFD simulations. * Generated a preliminary engineering model. 3-D CFD: Z.J. Wang * 1/6 -1/3 of the span (from Jeffrey Bons' experiment) selected for the computational domain; * 2 mm, 1 mm and 0.5 mm resolutions for coarse, medium and

83

Chemical behavior of degradation products of tributylphosphate in purex reprocessing  

SciTech Connect

Chemical behavior of butyl nitrate/butyl alcohol, degradation products from dealkylation of tri-n-butylphosphate(TBP) in PUREX reprocessing, which has not so far been reported, was investigated. No accumulation of those compounds in the organic phase of TBP(30%)-dodecane was observed in any separation cycle of PUREX despite the fact that the apparent distribution of the compounds lies to the organic phase at their high concentrations. The distribution of butyl nitrate/butyl alcohol between organic/aqueous phases is found to be dependent on their concentrations and on nitric acid concentration, which could explain the above phenomena. Only butyl nitrate of the above two compounds was slightly detected in the organic streams. It is probable from this investigation that butyl nitrate is removed into aqueous waste stream primarily through alkali scrubber.

Kuno, Y.; Sato, S.; Masui, J. [Power Reactor and Nuclear Fuel Development Corp., Ibaraki (Japan)] [and others

1995-12-01T23:59:59.000Z

84

Observations of pulsating Marangoni phenomena during the local oxidation of deoxidized liquid steel  

Science Journals Connector (OSTI)

...from the reacting gas species, D is the...the centre of the gas inlet tube as a function...the deoxidation solubility product at 1600 C...from the edge of the gas inlet tube as a function...experiments with water and surfactant-enriched...the dissolution of nitrogen into liquid iron...

1998-01-01T23:59:59.000Z

85

Modified Phenomena Identification and Ranking Table (PIRT) for Uncertainty Analysis  

SciTech Connect

This paper describes a methodology of characterizing important phenomena, which is also part of a broader research by the authors called 'Modified PIRT'. The methodology provides robust process of phenomena identification and ranking process for more precise quantification of uncertainty. It is a two-step process of identifying and ranking methodology based on thermal-hydraulics (TH) importance as well as uncertainty importance. Analytical Hierarchical Process (AHP) has been used for as a formal approach for TH identification and ranking. Formal uncertainty importance technique is used to estimate the degree of credibility of the TH model(s) used to represent the important phenomena. This part uses subjective justification by evaluating available information and data from experiments, and code predictions. The proposed methodology was demonstrated by developing a PIRT for large break loss of coolant accident LBLOCA for the LOFT integral facility with highest core power (test LB-1). (authors)

Gol-Mohamad, Mohammad P.; Modarres, Mohammad; Mosleh, Ali [University of Maryland, College Park, MD 20742 (United States)

2006-07-01T23:59:59.000Z

86

Phenomena Identification and Ranking Technique (PIRT) Panel Meeting Summary Report  

SciTech Connect

Phenomena Identification and Ranking Technique (PIRT) is a systematic way of gathering information from experts on a specific subject and ranking the importance of the information. NRC, in collaboration with DOE and the working group, conducted the PIRT exercises to identify safety-relevant phenomena for NGNP, and to assess and rank the importance and knowledge base for each phenomenon. The overall objective was to provide NRC with an expert assessment of the safety-relevant NGNP phenomena, and an overall assessment of R and D needs for NGNP licensing. The PIRT process was applied to five major topical areas relevant to NGNP safety and licensing: (1) thermofluids and accident analysis (including neutronics), (2) fission product transport, (3) high temperature materials, (4) graphite, and (5) process heat for hydrogen cogeneration.

Mark Holbrook

2007-07-01T23:59:59.000Z

87

Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

STATEMENT. Approved for public release; distribution is unlimited. STATEMENT. Approved for public release; distribution is unlimited. DOE-STD-1020-2012 December 2012 _________________ Supersedes DOE-STD-1020-2002 DOE STANDARD Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities U.S. Department of Energy AREA NPHZ Washington, D.C. 20585 NOT MEASUREMENT SENSITIVE DOE-STD-1020-2012 This document is available on the Department of Energy Technical Standards Program Web page at http://www.hss.doe.gov/nuclearsafety/ns/techstds/ DOE-STD-1020-2012 i Foreword Department of Energy (DOE) Standard (STD)-1020-2012, Natural Phenomena Hazards

88

Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

STATEMENT. Approved for public release; distribution is unlimited. STATEMENT. Approved for public release; distribution is unlimited. DOE-STD-1020-2012 December 2012 _________________ Supersedes DOE-STD-1020-2002 DOE STANDARD Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities U.S. Department of Energy AREA NPHZ Washington, D.C. 20585 NOT MEASUREMENT SENSITIVE DOE-STD-1020-2012 This document is available on the Department of Energy Technical Standards Program Web page at http://www.hss.doe.gov/nuclearsafety/ns/techstds/ DOE-STD-1020-2012 i Foreword Department of Energy (DOE) Standard (STD)-1020-2012, Natural Phenomena Hazards

89

RELAP5-3D Code Validation for RBMK Phenomena  

SciTech Connect

The RELAP5-3D thermal-hydraulic code was assessed against Japanese Safety Experiment Loop (SEL) and Heat Transfer Loop (HTL) tests. These tests were chosen because the phenomena present are applicable to analyses of Russian RBMK reactor designs. The assessment cases included parallel channel flow fluctuation tests at reduced and normal water levels, a channel inlet pipe rupture test, and a high power, density wave oscillation test. The results showed that RELAP5-3D has the capability to adequately represent these RBMK-related phenomena.

Fisher, James Ebberly

1999-09-01T23:59:59.000Z

90

RELAP5-3D code validation for RBMK phenomena  

SciTech Connect

The RELAP5-3D thermal-hydraulic code was assessed against Japanese Safety Experiment Loop (SEL) and Heat Transfer Loop (HTL) tests. These tests were chosen because the phenomena present are applicable to analyses of Russian RBMK reactor designs. The assessment cases included parallel channel flow fluctuation tests at reduced and normal water levels, a channel inlet pipe rupture test, and a high power, density wave oscillation test. The results showed that RELAP5-3D has the capability to adequately represent these RBMK-related phenomena.

Fisher, J.E.

1999-09-01T23:59:59.000Z

91

Used Fuel Degradation: Experimental and Modeling Report  

Energy.gov (U.S. Department of Energy (DOE))

The report describes the strategy for coupling process level models to produce an integrated Used Fuel Degradation Model (FDM), and addresses fractional degradation rate, instant release fractions, other continuum modeling approaches, and experimental support.

92

PEM Degradation Investigation Final Technical Report  

SciTech Connect

This project conducted fundamental studies of PEM MEA degradation. Insights gained from these studies were disseminated to assist MEA manufacturers in understanding degradation mechanisms and work towards DOE 2010 fuel cell durability targets.

Dan Stevenson; Lee H Spangler

2010-10-18T23:59:59.000Z

93

Local Transportation  

E-Print Network (OSTI)

Local Transportation. Transportation from the Airport to Hotel. There are two types of taxi companies that operate at the airport: special and regular taxis (

94

Physical Degradation of Soils, Risks and Threats  

Science Journals Connector (OSTI)

Physical soil degradation...is one of the eight main risks and threats defined by the European Thematic Strategy for...

Winfried E. H. Blum

2014-08-01T23:59:59.000Z

95

Why Sequence Cellulose Degrading Bacteria?  

NLE Websites -- All DOE Office Websites (Extended Search)

Cellulose Degrading Bacteria? Cellulose Degrading Bacteria? One of the major DOE missions is the production of renewable fuels to reduce our dependence on foreign oil, and also to take the place of petroleum-based fuels as these resources dwindle. Biologically produced ethanol is one possible replacement for fossil fuels. Currently, ethanol is produced from corn starch, but there is much research into using lignocellulosic materials (those containing cellulose, hemicellulose, and lignin) as the raw material for ethanol production. Ethanol production from cellulose requires several steps: pretreatment with steam, acid, or ammonia; digestion of cellulose to sugars; and fermentation of sugars to ethanol. The slowest and most expensive step is the breakdown of cellulose, chemically accomplished by cellulases. The second and third

96

Degradation of Ionic Pathway in PEM Fuel Cell Cathode. | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

Degradation of Ionic Pathway in PEM Fuel Cell Cathode. Degradation of Ionic Pathway in PEM Fuel Cell Cathode. Abstract: The degradation of the ionic pathway throughout the catalyst...

97

Degradation  

NLE Websites -- All DOE Office Websites (Extended Search)

Cryogenic photomultiplier tube (PMT) assemblies 4 First mounted optical assembly PMT rack installation test Handsome grad student in the recently opened cryostat 5 LBNE Optical...

98

October 2014 Natural Phenomena Hazards (NPH) Meeting- Tuesday, October 21st Session Presentations  

Energy.gov (U.S. Department of Energy (DOE))

Presentations from the October 2014 Natural Phenomena Hazards Meeting - Tuesday, October 21st Session

99

October 2014 Natural Phenomena Hazards (NPH) Meeting- Wednesday, October 22nd Soil Structure Interaction Presentations  

Energy.gov (U.S. Department of Energy (DOE))

Presentations for the Soil Structure Interaction session at the October 2014 Natural Phenomena Hazards (NPH) Meeting.

100

October 2014 Natural Phenomena Hazards (NPH) Meeting- Wednesday, October 22nd Session Presentations  

Energy.gov (U.S. Department of Energy (DOE))

Presentations from the October 2014 Natural Phenomena Hazards Meeting - Tuesday, October 21st Session

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Fundamental phenomena of quantum mechanics explored with neutron interferometers  

E-Print Network (OSTI)

Ongoing fascination with quantum mechanics keeps driving the development of the wide field of quantum-optics, including its neutron-optics branch. Application of neutron-optical methods and, especially, neutron interferometry and polarimetry has a long-standing tradition for experimental investigations of fundamental quantum phenomena. We give an overview of related experimental efforts made in recent years.

J. Klepp; S. Sponar; Y. Hasegawa

2014-07-09T23:59:59.000Z

102

Phenomena identification and ranking tables (PIRT) for LBLOCA  

SciTech Connect

The US Nuclear Regulatory Commission is sponsoring a program to provide validated reactor safety computer codes with quantified uncertainties. The intent is to quantify the accuracy of the codes for use in best estimate licensing applications. One of the tasks required to complete this program involves the identification and ranking of thermal-hydraulic phenomena that occur during particular accidents. This paper provides detailed tables of phenomena and importance ranks for a PWR LBLOCA. The phenomena were identified and ranked according to perceived impact on peak cladding temperature. Two approaches were used to complete this task. First, a panel of experts identified the physical processes considered to be most important during LBLOCA. A second team of experienced analysts then, in parallel, assembled complete tables of all plausible LBLOCA phenomena, regardless of perceived importance. Each phenomenon was then ranked in importance against every other phenomenon associated with a given component. The results were placed in matrix format and solved for the principal eigenvector. The results as determined by each method are presented in this report.

Shaw, R.A.; Dimenna, R.A.; Larson, T.K.; Wilson, G.E.

1987-01-01T23:59:59.000Z

103

The Lattice-Boltzmann Method for Simulating Gaseous Phenomena  

E-Print Network (OSTI)

The Lattice-Boltzmann Method for Simulating Gaseous Phenomena Xiaoming Wei, Student Member, IEEE animation. We introduce the Lattice Boltzmann Model (LBM), which simulates the microscopic movement of fluid in real-time, while still maintaining highly plausible visual details. Index Terms--Lattice Boltzmann

Mueller, Klaus

104

Chapter 7. Renewal Phenomena Renewal is life reborn.  

E-Print Network (OSTI)

51 Chapter 7. Renewal Phenomena Renewal is life reborn. 7.1. Definitions and basic concepts. 7. Then, N(t) : t 0, is a renewal process. A mathematical definition: N(t) = max{n : n i=0 Xi t, } where, ...} or continuous: [0, ). Obviously, the path of a renewal process is non-decreasing. The renewal literally means

Chen, Kani

105

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-Print Network (OSTI)

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions CSIRO CSS TCP Detournay (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

106

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-Print Network (OSTI)

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions SANUM Conference (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

107

Computational analysis of temperature rise phenomena in electric induction motors  

E-Print Network (OSTI)

Computational analysis of temperature rise phenomena in electric induction motors Ying Huai Institute, University of Southern Denmark, Grundvigs Alle 150, Sonderborg, DK-6400, Denmark c Danfoss Drives A/S, Denmark Received 12 October 2002; accepted 20 December 2002 Abstract In developing electric

Melnik, Roderick

108

General Search for New Phenomena in ep Scattering at HERA  

E-Print Network (OSTI)

General Search for New Phenomena in ep Scattering at HERA The IVIIth Rencontres de Moriond on QCD algorithm investigate all final states produced at high PT in ep collisions do not rely on assumptions about 3 General Search @ H1 Data samples HERA I (1992-2000) HERA II (2002-2007) HERA I: e+p dominated (GS

109

Nonlocal collisionless phenomena in Plasmas PPPL, Princeton 2005  

E-Print Network (OSTI)

1 Nonlocal collisionless phenomena in Plasmas PPPL, Princeton 2005 A. Dunaevsky Measurements. of Astrophysical Sciences Princeton University, Princeton, NJ 08543 #12;2 Diagnostics in expanding plasmas" by A. Dunaevsky Princeton 2005 #12;3 Kinetics of expanding plasmaKinetics of expanding plasma Kinetics

Kaganovich, Igor

110

Shooting Methods for Locating Grazing Phenomena in Hybrid Systems  

E-Print Network (OSTI)

Shooting Methods for Locating Grazing Phenomena in Hybrid Systems Vaibhav Donde Ian A. Hiskens Abstract Hybrid systems are typified by strong coupling between continuous dynamics and discrete events using shooting methods that are applicable for general nonlinear hybrid (piecewise smooth) dynamical

111

Measuring Degradation Rates Without Irradiance Data  

SciTech Connect

A method to report PV system degradation rates without using irradiance data is demonstrated. First, a set of relative degradation rates are determined by comparing daily AC final yields from a group of PV systems relative to the average final yield of all the PV systems. Then, the difference between relative and absolute degradation rates is found from a statistical analysis. This approach is verified by comparing to methods that utilize irradiance data. This approach is significant because PV systems are often deployed without irradiance sensors, so the analysis method described here may enable measurements of degradation using data that were previously thought to be unsuitable for degradation studies.

Pulver, S.; Cormode, D.; Cronin, A.; Jordan, D.; Kurtz, S.; Smith, R.

2011-02-01T23:59:59.000Z

112

Calorimetric analysis of fungal degraded wood  

SciTech Connect

Endothermic transition and gross heat of combustion of aspenwood subjected to degradation by Lenzites trabea and Polyporus versicolor were determined by using differential scanning calorimetry (DSC) and an adiabatic O bomb. Endothermic peak areas of undegraded and fungi-degraded wood differed from each other at all levels of weight loss. The regression analysis of the DSC data vs. weight loss revealed a significant relations, although not highly correlated, for P. versicolor-degraded specimens and a nonsignificant relation for L. trabea-degraded specimens; weight loss and gross heat of combustion values of degraded specimens were significantly correlated.

Blankenhorn, P.R.; Baldwin, R.C.; Merrill, W. Jr.; Ottone, S.P.

1980-01-01T23:59:59.000Z

113

Magnetic reconnection as a possible heating mechanism of the local high temperature protons within magnetic clouds  

Science Journals Connector (OSTI)

Magnetic clouds have the outstanding observational features of low proton temperature and plasma beta value, but numerous observations show that some magnetic clouds often have local high temperature phenomena...

HengQiang Feng; JieMin Wang

2014-08-01T23:59:59.000Z

114

Research subjects for analytical estimation of core degradation at Fukushima-Daiichi nuclear power plant  

SciTech Connect

Estimation of the accident progress and status inside the pressure vessels (RPV) and primary containment vessels (PCV) is required for appropriate conductance of decommissioning in the Fukushima-Daiichi NPP. For that, it is necessary to obtain additional experimental data and revised models for the estimation using computer codes with increased accuracies. The Japan Atomic Energy Agency (JAEA) has selected phenomena to be reviewed and developed, considering previously obtained information, conditions specific to the Fukushima-Daiichi NPP accident, and recent progress of experimental and analytical technologies. As a result, research and development items have been picked up in terms of thermal-hydraulic behavior in the RPV and PCV, progression of fuel bundle degradation, failure of the lower head of RPV, and analysis of the accident. This paper introduces the selected phenomena to be reviewed and developed, research plans and recent results from the JAEA's corresponding research programs. (authors)

Nagase, F.; Ishikawa, J.; Kurata, M.; Yoshida, H.; Kaji, Y.; Shibamoto, Y.; Amaya, M; Okumura, K.; Katsuyama, J. [Fukushima Project Team, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan)

2013-07-01T23:59:59.000Z

115

ESM of Ionic and Electrochemical Phenomena on the Nanoscale  

SciTech Connect

Operation of energy storage and conversion devices is ultimately controlled by series of intertwined ionic and electronic transport processes and electrochemical reactions at surfaces and interfaces, strongly mediated by strain and mechanical processes [1-4]. In a typical fuel cell, these include chemical species transport in porous cathode and anode materials, gas-solid electrochemical reactions at grains and triple-phase boundaries (TPBs), ionic and electronic flows in multicomponent electrodes, and chemical and electronic potential drops at internal interfaces in electrodes and electrolytes. All these phenomena are sensitively affected by the microstructure of materials from device level to the atomic scales as illustrated in Fig. 1. Similar spectrum of length scales and phenomena underpin operation of other energy systems including primary and secondary batteries, as well as hybrid systems such flow and metal-air/water batteries.

Kalinin, Sergei V [ORNL; Kumar, Amit [Pennsylvania State University; Balke, Nina [ORNL; McCorkle, Morgan L [ORNL; Guo, Senli [ORNL; Arruda, Thomas M [ORNL; Jesse, Stephen [ORNL

2011-01-01T23:59:59.000Z

116

Natural hazards phenomena mitigation with respect to seismic hazards at the Environmental Restoration Disposal Facility  

SciTech Connect

This report provides information on the seismic hazard for design of the proposed Environmental Restoration Disposal Facility (ERDF), a facility designed for the disposal of wastes generated during the cleanup of Hanford Site aggregate areas. The preferred ERDF site is located south and east of 200 East and 200 West Areas. The Washington State Groundwater Protection Program (WAC 173-303-806 (4)(a)(xxi)) requires that the characteristics of local and regional hydrogeology be defined. A plan for that work has been developed (Weekes and Borghese 1993). In addition, WAC 173-303-282 provides regulatory guidance on siting a dangerous waste facility, and US Department of Energy (DOE) Order 5480.28 requires consideration of natural phenomena hazards mitigation for DOE sites and facilities. This report provides information to evaluate the ERDF site with respect to seismic hazard. The ERDF will be a Corrective Action Management Unit (CAMU) as defined by 40 CFR 260.10.

Reidel, S.P.

1994-01-06T23:59:59.000Z

117

Gamma-Ray Bursts: Super-Explosions in the Universe and Related High-Energy Phenomena  

E-Print Network (OSTI)

The recent progress in studies of gamma-ray bursts, their afterglows, and host galaxies is discussed. The emphasis is given to high-energy phenomena associated with gamma-ray burst explosions: high-energy cosmic rays, neutrinos, gravitational waves. We also show how the relativistic fireball model for GRBs can be used to constrain modern theories of large and infinite extra-dimensions. In particular, in the frame of 5D gravity with the Standard Model localized on 3D brane (Dvali et al. 2000), the very existence of relativistic fireballs of $\\sim 10^{53}$ ergs puts the lower bound on the quantum gravity scale $\\sim 0.1$ eV.

K. A. Postnov

2001-07-06T23:59:59.000Z

118

Local Information  

NLE Websites -- All DOE Office Websites (Extended Search)

Local Information Local Information Local Information Welcome to Golden, Colorado, the location of the 2014 Electrical Safety Workshop. Visiting NREL The National Renewable Energy Laboratory (NREL) has research facilities and offices at several locations in Golden, Colorado (near Boulder), and in Washington, D.C. In Golden, you'll find the NREL Education Center, along with many of our research laboratories and administrative offices. The National Wind Technology Center is a separate facility located about 5 miles south of Boulder. Read more » Transportation NREL is accessible via bus on the Regional Transportation District (RTD) Route 20 from Aurora and Denver. Route 20 travels along 20th Avenue and ends at the NREL Education Center. Visit the RTD Web site or call 303-299-6000 to plan your trip or for more

119

Photovoltaic Degradation Rates -- An Analytical Review  

SciTech Connect

As photovoltaic penetration of the power grid increases, accurate predictions of return on investment require accurate prediction of decreased power output over time. Degradation rates must be known in order to predict power delivery. This article reviews degradation rates of flat-plate terrestrial modules and systems reported in published literature from field testing throughout the last 40 years. Nearly 2000 degradation rates, measured on individual modules or entire systems, have been assembled from the literature, showing a median value of 0.5%/year. The review consists of three parts: a brief historical outline, an analytical summary of degradation rates, and a detailed bibliography partitioned by technology.

Jordan, D. C.; Kurtz, S. R.

2012-06-01T23:59:59.000Z

120

Sonoelectrochemical degradation of triclosan in water  

Science Journals Connector (OSTI)

Abstract The sonoelectrochemical degradation of triclosan in aqueous solutions with high-frequency ultrasound (850 kHz) and various electrodes was investigated. Diamond coated niobium electrode showed the best results and was used as standard electrode, leading to effective degradation and positive synergistic effect. The influence of different parameters on the degradation degree and energy efficiency were evaluated and favorable reaction conditions were found. It could be shown that 92% of triclosan (1 mg L?1 aqueous solution) was degraded within 15 min, following pseudo-first order kinetics.

Yan-Ze Ren; Marcus Franke; Franziska Anschuetz; Bernd Ondruschka; Anna Ignaszak; Patrick Braeutigam

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Durability Improvements Through Degradation Mechanism Studies...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Through Degradation Mechanism Studies Presented at the Department of Energy Fuel Cell Projects Kickoff Meeting, September 1 - October 1, 2009 boruplanlkickoff.pdf...

122

Locally Led Conservation The Local Work Group  

E-Print Network (OSTI)

1 Locally Led Conservation & The Local Work Group Mark Habiger NRCS #12;2 What Is "Locally Led ­ 5. Implementing solutions ­ 6. Measuring their success #12;3 The Locally Led Principle Locally led-Economic Concerns · Program Identification · Stakeholder Commitment #12;6 Who Leads the Locally Led Effort? · Local

123

Sonochemical degradation of Congo Red  

Science Journals Connector (OSTI)

Ultrasound irradiation was found to be effective in treatment of refractory pollutants. The present communication reports ultrasound treatment of Congo Red (CR). The CR degradation by ultrasonic waves (50 kHz) was investigated at 25°C. After sonication for 60 min, the CR concentration gradually decreased from 100 mg/L to 27.7 mg/L. pH of the sonicated CR solution decreased from 6.8 to 4.2. Oxygen uptake rate demonstrated higher uptake of oxygen by microbia in the case of the sonicated sample. There is 68% chemical oxygen demand removal efficiency after ultrasound treatment. The combination of ultrasound and biodegradation in treatment of CR is studied here.

Srinivas Sistla; Suresh Chintalapati

2008-01-01T23:59:59.000Z

124

Effects of oceanic and atmospheric phenomena on precipitation and flooding in the Manafwa River Basin  

E-Print Network (OSTI)

An investigation was performed to determine the relationship between certain oceanic and atmospheric phenomena and the precipitation patterns in the Manafwa River Basin of eastern Uganda. Such phenomena are the El Niño ...

Finney, William W., III (William Warner)

2014-01-01T23:59:59.000Z

125

October 2014 Natural Phenomena Hazards (NPH) Meeting- Wednesday, October 22nd Session Presentations  

Energy.gov (U.S. Department of Energy (DOE))

Presentations from the Wednesday, October 22nd Session of the October 2014 Natural Phenomena Hazards (NPH) Meeting

126

ACCELERATED DESTRUCTIVE DEGRADATION TESTS: DATA, MODELS,  

E-Print Network (OSTI)

ACCELERATED DESTRUCTIVE DEGRADATION TESTS: DATA, MODELS, AND ANALYSIS Luis A. Escobar Dept are often accelerated by testing at higher than usual levels of accelerating variables like temperature. This chapter describes an important class of models for accelerated destructive degradation data. We use

127

Pantex Facility 10-Year Natural Phenomena Flood Hazard Analysis  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Pantex Facility 10-Year Natural Pantex Facility 10-Year Natural Phenomena Flood Hazard Analysis Presented by and October, 2011 Presentation Outline I. Introductions II. Pantex III. 10 Year Update IV. Final Results V. July 2010 Event VI. Emergency Planning VII.What's Next Pantex The Pantex Plant, located 17 miles northeast of Amarillo, Texas, in Carson County, is charged with maintaining the safety, security and reliability of the nation's nuclear weapons stockpile. Worked performed at Pantex supports three core missions. * Stockpile Stewardship * Nonproliferation and * Safeguards and Security Pantex (cont.) - Location Pantex (cont.) - Weather Patterns * Precipitation is typical for Southwest climate, mainly in the form of Spring and

128

Thermomagnetic phenomena in the mixed state of high temperature superconductors  

SciTech Connect

Galvano- and thermomagnetic-phenomena in high temperature superconductors, based on kinetic coefficients, are discussed, along with a connection between the electric field and the heat flow in superconductor mixed state. The relationship that determines the transport coefficients of high temperature superconductors in the mixed state based on Seebeck and Nernst effects is developed. It is shown that this relationship is true for a whole transition region of the resistive mixed state of a superconductor. Peltier, Ettingshausen and Righi-Leduc effects associated with heat conductivity as related to high temperature superconductors are also addressed.

Meilikhov, E.Z.

1995-04-01T23:59:59.000Z

129

MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS Presentation  

E-Print Network (OSTI)

MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS Presentation A A A A A A MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS MAGNETIC QUANTUM TUNNELING AND RELATED PHENOMENA IN SINGLE MOLECULE MAGNETS ENRIQUE DEL BARCOENRIQUE DEL BARCO Physics Department - New

del Barco, Enrique

130

Squeezout phenomena and boundary layer formation of a model ionic liquid under confinement and charging  

E-Print Network (OSTI)

Electrical charging of parallel plates confining a model ionic liquid down to nanoscale distances yields a variety of charge-induced changes in the structural features of the confined film. That includes even-odd switching of the structural layering and charging-induced solidification and melting, with important changes of local ordering between and within layers, and of squeezout behavior. By means of molecular dynamics simulations, we explore this variety of phenomena in the simplest charged Lennard-Jones coarse-grained model including or excluding the effect a neutral tail giving an anisotropic shape to one of the model ions. Using these models and open conditions permitting the flow of ions in and out of the interplate gap, we simulate the liquid squeezout to obtain the distance dependent structure and forces between the plates during their adiabatic appraoch under load. Simulations at fixed applied force illustrate an effective electrical pumping of the ionic liquid, from a thick nearly solid film that withstands the interplate pressure for high plate charge to complete squeezout following melting near zero charge. Effective enthalpy curves obtained by integration of interplate forces versus distance show the local minima that correspond to layering, and predict the switching between one minimum and another under squeezing and charging.

R. Capozza; A. Vanossi; A. Benassi; E. Tosatti

2014-12-22T23:59:59.000Z

131

Predicting toluene degradation in organic Rankine-cycle engines  

SciTech Connect

This paper describes the measurement of toluene degradation in dynamic loop tests that simulate operation of an organic Rankine-cycle engine. Major degradation products and degradation mechanisms are identified, and degradation is quantified. Results indicate that toluene is a stable fluid with benign degradation products, provided that oxygen is excluded from the engine. A means of predicting degradation in the engine is developed. 3 refs., 4 figs., 5 tabs.

Cole, R.L.; Demirgian, J.C.; Allen, J.W.

1987-01-01T23:59:59.000Z

132

Accurate Numerical Simulations Of Chemical Phenomena Involved in Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Visualization of the spin density from the excess electron cluster. Robert Visualization of the spin density from the excess electron cluster. Robert Harrison Accurate Numerical Simulations Of Chemical Phenomena Involved in Energy Production and Storage with MADNESS and MPQC PI Name: Robert Harrison PI Email: harrisonrj@ornl.gov Institution: ORNL Allocation Program: ESP Allocation Hours at ALCF: 150 Million Year: 2010 to 2013 Research Domain: Chemistry Researchers propose to focus on the problems of catalysis and heavy element chemistry for fuel reprocessing-both of which are of immediate interest to the Department of Energy (DOE), are representative of a very broad class of problems in chemistry, and demand the enormous computational resources anticipated from the next generation of leadership computing facilities. Also common to both is the need for accurate electronic structure

133

DOE Standard Natural Phenomena Hazards Site Characterization Criteria  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2-94 2-94 March 1994 Change Notice No. 1 January 1996 Reaffirmed with Errata April 2002 DOE STANDARD NATURAL PHENOMENA HAZARDS SITE CHARACTERIZATION CRITERIA U.S. Department of Energy AREA FACR Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Environment Safety and Health Technical Information Services, U.S. Department of Energy, (800) 473-4376, Fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650. DOE-STD-1022-94 ERRATA FOR DOE-STD-1022-94 REVISED FOREWORD ADDED REFERENCE TO DOE G 420.1-2

134

Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells  

SciTech Connect

Hydrogen can be produced from water splitting with relatively high efficiency using high temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high temperature process heat. The overall thermal-to-hydrogen efficiency for high temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. An overview of high temperature electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.

James E. O'Brien

2012-03-01T23:59:59.000Z

135

Key Thermal Fluid Phenomena In Prismatic Gas-Cooled Reactors  

SciTech Connect

Several types of gas-cooled nuclear reactors have been suggested as part of the international Generation IV initiative with the proposed NGNP (Next Generation Nuclear Plant) as one of the main concepts [MacDonald et al., 2003]. Meaningful studies for these designs will require accurate, reliable predictions of material temperatures to evaluate the material capabilities; these temperatures depend on the thermal convection in the core and in other important components. Some of these reactors feature complex geometries and wide ranges of temperatures, leading to significant variations of the gas thermodynamic and transport properties plus possible effects of buoyancy during normal and reduced power operations and loss-of-flow (LOFA) and loss-of-coolant scenarios. Potential issues identified to date include ''hot streaking'' in the lower plenum evolving from ''hot channels'' in prismatic cores. In order to predict thermal hydraulic behavior of proposed designs effectively and efficiently, it is useful to identify the dominant phenomena occurring.

D. M. McEligot; G. E. McCreery; P. D. Bayless; T. D. Marshall

2005-06-01T23:59:59.000Z

136

Lorentz violation at high energy: concepts, phenomena and astrophysical constraints  

E-Print Network (OSTI)

We consider here the possibility of quantum gravity induced violation of Lorentz symmetry (LV). Even if suppressed by the inverse Planck mass such LV can be tested by current experiments and astrophysical observations. We review the effective field theory approach to describing LV, the issue of naturalness, and many phenomena characteristic of LV. We discuss some of the current observational bounds on LV, focusing mostly on those from high energy astrophysics in the QED sector at order E/M_Planck. In this context we present a number of new results which include the explicit computation of rates of the most relevant LV processes, the derivation of a new photon decay constraint, and modification of previous constraints taking proper account of the helicity dependence of the LV parameters implied by effective field theory.

Ted Jacobson; Stefano Liberati; David Mattingly

2005-06-11T23:59:59.000Z

137

Probing the Degradation Mechanisms in Electrolyte Solutions for...  

NLE Websites -- All DOE Office Websites (Extended Search)

Degradation Mechanisms in Electrolyte Solutions for Li-ion Batteries by In-Situ Transmission Electron Microscopy. Probing the Degradation Mechanisms in Electrolyte Solutions for...

138

Characterization of Trapped Lignin-Degrading Microbes in Tropical...  

NLE Websites -- All DOE Office Websites (Extended Search)

Trapped Lignin-Degrading Microbes in Tropical Forest Soil. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil. Abstract: Lignin is often the most...

139

High-Resolution Crack Imaging Reveals Degradation Processes in...  

NLE Websites -- All DOE Office Websites (Extended Search)

Crack Imaging Reveals Degradation Processes in Nuclear Reactor Structural Materials. High-Resolution Crack Imaging Reveals Degradation Processes in Nuclear Reactor Structural...

140

Degradation mechanism and surface modification of biomedical magnesium alloy.  

E-Print Network (OSTI)

???The degradability of magnesium and magnesium alloys in a physiological environment makes them desirable biodegradable biomaterials in many applications. However, their fast degradation rates in… (more)

Xin, Yunchang (???)

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

In-situ characterization and diagnostics of mechanical degradation...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

In-situ characterization and diagnostics of mechanical degradation in electrodes In-situ characterization and diagnostics of mechanical degradation in electrodes 2011 DOE Hydrogen...

142

Uncertainty Analysis for Photovoltaic Degradation Rates (Poster)  

SciTech Connect

Dependable and predictable energy production is the key to the long-term success of the PV industry. PV systems show over the lifetime of their exposure a gradual decline that depends on many different factors such as module technology, module type, mounting configuration, climate etc. When degradation rates are determined from continuous data the statistical uncertainty is easily calculated from the regression coefficients. However, total uncertainty that includes measurement uncertainty and instrumentation drift is far more difficult to determine. A Monte Carlo simulation approach was chosen to investigate a comprehensive uncertainty analysis. The most important effect for degradation rates is to avoid instrumentation that changes over time in the field. For instance, a drifting irradiance sensor, which can be achieved through regular calibration, can lead to a substantially erroneous degradation rates. However, the accuracy of the irradiance sensor has negligible impact on degradation rate uncertainty emphasizing that precision (relative accuracy) is more important than absolute accuracy.

Jordan, D.; Kurtz, S.; Hansen, C.

2014-04-01T23:59:59.000Z

143

Tetrachloroethylene Degradation by Dithionite with Ultraviolet Activation  

E-Print Network (OSTI)

. This project has conducted research on degrading PCE with an ARP that combines dithionite and ultraviolet activation. The purpose of the project is to provide knowledge for the development of potential wastewater treatment technologies. Several control...

Zhang, Jingyuan

2013-07-30T23:59:59.000Z

144

Chemotactic selection of pollutant degrading soil bacteria  

DOE Patents (OSTI)

A method is described for identifying soil microbial strains which may be bacterial degraders of pollutants. This method includes: Placing a concentration of a pollutant in a substantially closed container; placing the container in a sample of soil for a period of time ranging from one minute to several hours; retrieving the container and collecting its contents; microscopically determining the identity of the bacteria present. Different concentrations of the pollutant can be used to determine which bacteria respond to each concentration. The method can be used for characterizing a polluted site or for looking for naturally occurring biological degraders of the pollutant. Then bacteria identified as degraders of the pollutant and as chemotactically attracted to the pollutant are used to innoculate contaminated soil. To enhance the effect of the bacteria on the pollutant, nutrients are cyclicly provided to the bacteria then withheld to alternately build up the size of the bacterial colony or community and then allow it to degrade the pollutant.

Hazen, T.C.

1991-03-04T23:59:59.000Z

145

Degradation of Structural Alloys Under Thermal Insulation  

E-Print Network (OSTI)

Wet thermal insulation may actively degrade steel and stainless steel structures by general corrosion or stress-corrosion cracking. Two different mechanisms of water ingress into insulation are discussed; flooding from external sources...

McIntyre, D. R.

1984-01-01T23:59:59.000Z

146

Method of degrading pollutants in soil  

DOE Patents (OSTI)

Disclosed are a method and system for enhancing the motility of microorganisms. This is accomplished by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant. 5 figures.

Hazen, T.C.; Lopez-De-Victoria, G.

1994-07-05T23:59:59.000Z

147

Durability Improvements Through Degradation Mechanism Studies  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

degradation mechanisms over 1000 hrs - conclude membrane AST testing G3: LANL: X-Ray Tomography to provide resolution < 1 micron pore changes. GoNo: If not able to detect...

148

Soil degradation, global warming and climate impacts  

E-Print Network (OSTI)

will demonstrate one methodology for assessing the potential large-scale impacts of soil degradation on African climates and water resources. In addition it will compare and contrast these impacts to those expected from global warming and compare impacts for differ...- ent watershed regions on the continent. 2. METHODS In order to make a similar comparison between pro- jected climate change scenarios due to global warming © Inter-Research 2001 *E-mail: feddema@ku.edu Soil degradation, global warming and climate...

Feddema, Johannes J.; Freire, Sergio Carneiro

2001-01-01T23:59:59.000Z

149

Types of Land Degradation in Bhutan  

E-Print Network (OSTI)

of other nutrients Possible eutrophication or contamination of streams Excessive P fertiliser (potato and apple crops) Possible excess P fertiliser applied to apples in W Bhutan Eutrophicatio n unlikely in fast flowing streams... highly vulnerable to surface erosion Effluents from plants, workshops & urban waste Not extensive – but some cases around Thimphu & in South Table 2: Types of Degradation (In Situ Degradation-Physical) 1. Soil Type: Topsoil...

Chencho Norbu et al,

2003-01-01T23:59:59.000Z

150

Evaluation of commercial lithium-ion cells based on composite positive electrode for plug-in hybrid electric vehicle applications. Part II. Degradation mechanism under 2 C cycle aging  

SciTech Connect

Degradation phenomena and inference of their underlying mechanisms during 2 C cycle aging in a cell design comprising {l_brace}LiMn1/3Ni1/3Co1/3O2 + LiMn2O4{r_brace} composite positive electrode are studied and reported in this work. We describe how aging phenomena in the cells were studied and incremental capacity analysis applied to infer cell degradation mechanisms in the cycle aging process. Two stages of degradation were observed in the life cycle under this aging regime. In the first stage, we conclude that loss of lithium inventory was the cause of capacity fade. As a result of such parasitic loss, the cell further suffered from loss of active materials in the second stage, in which the positive electrode kinetics was hampered and the capacity loss accelerated.

Matthieu Dubarry; Cyril Truchot; Bor Yann Liaw; Kevin Gering; Sergiy Sazhin; David Jamison; Christopher Michelbacher

2011-12-01T23:59:59.000Z

151

Analysis of the spatially distributed performance degradation of a polymer electrolyte membrane fuel cell stack  

Science Journals Connector (OSTI)

Abstract Herein we report the spatially uneven degradation of a polymer electrolyte membrane fuel cell (PEMFC) stack operated under load variation. Fifteen sub-membrane electrode assemblies (sub-MEAs) at various cell positions and various points within each cell were obtained from the original \\{MEAs\\} employed in the fuel cell stack. Polarization curves and the voltammetric charge of these \\{MEAs\\} were measured in order to correlate localized performances with the redistributed electrochemically active surface on Pt using the polarization technique and cyclic voltammetry. Several ex situ characterizations including electron probe microanalysis, environmental scanning electron microscopy, and X-ray diffraction were also performed to find evidence, supporting the inhomogeneous degradation of the fuel cell stack. Possible routes and processes for the non-uniform stack degradation during the PEMFC stack operation will also be discussed.

Min Kyung Cho; Dae-Nyung Lee; Yi-Young Kim; Jonghee Han; Hyoung-Juhn Kim; EunAe Cho; Tae-Hoon Lim; Dirk Henkensmeier; Sung Jong Yoo; Yung-Eun Sung; Sehkyu Park; Jong Hyun Jang

2014-01-01T23:59:59.000Z

152

Final Report Inspection of Aged/Degraded Containments Program.  

SciTech Connect

The Inspection of Aged/Degraded Containments Program had primary objectives of (1) understanding the significant factors relating corrosion occurrence, efficacy of inspection, and structural capacity reduction of steel containments and liners of reinforced concrete containments; (2) providing the United States Nuclear Regulatory Commission (USNRC) reviewers a means of establishing current structural capacity margins or estimating future residual structural capacity margins for steel containments, and concrete containments as limited by liner integrity; (3) providing recommendations, as appropriate, on information to be requested of licensees for guidance that could be utilized by USNRC reviewers in assessing the seriousness of reported incidences of containment degradation; and (4) providing technical assistance to the USNRC (as requested) related to concrete technology. Primary program accomplishments have included development of a degradation assessment methodology; reviews of techniques and methods for inspection and repair of containment metallic pressure boundaries; evaluation of high-frequency acoustic imaging, magnetostrictive sensor, electromagnetic acoustic transducer, and multimode guided plate wave technologies for inspection of inaccessible regions of containment metallic pressure boundaries; development of a continuum damage mechanics-based approach for structural deterioration; establishment of a methodology for reliability-based condition assessments of steel containments and liners; and fragility assessments of steel containments with localized corrosion. In addition, data and information assembled under this program has been transferred to the technical community through review meetings and briefings, national and international conference participation, technical committee involvement, and publications of reports and journal articles. Appendix A provides a listing of program reports, papers, and publications; and Appendix B contains a listing of program-related presentations.

Naus, Dan J [ORNL; Ellingwood, B R [Georgia Institute of Technology; Oland, C Barry [ORNL

2005-09-01T23:59:59.000Z

153

Formation of morphogen gradients: Local accumulation time  

Science Journals Connector (OSTI)

Spatial regulation of cell differentiation in embryos can be provided by morphogen gradients, which are defined as the concentration fields of molecules that control gene expression. For example, a cell can use its surface receptors to measure the local concentration of an extracellular ligand and convert this information into a corresponding change in its transcriptional state. We characterize the time needed to establish a steady-state gradient in problems with diffusion and degradation of locally produced chemical signals. A relaxation function is introduced to describe how the morphogen concentration profile approaches its steady state. This function is used to obtain a local accumulation time that provides a time scale that characterizes relaxation to steady state at an arbitrary position within the patterned field. To illustrate the approach we derive local accumulation times for a number of commonly used models of morphogen gradient formation.

Alexander M. Berezhkovskii; Christine Sample; Stanislav Y. Shvartsman

2011-05-06T23:59:59.000Z

154

FCV Learning Demonstration: Factors Affecting Fuel Cell Degradation (Presentation)  

SciTech Connect

Presentation on factors affecting fuel cell degradation in the DOE Fuel Cell Vehicle learning demonstation.

Kurtz, J.; Wipke, K.; Sprik, S.

2007-11-15T23:59:59.000Z

155

Sorption and Degradation of Fipronil in Flooded Anaerobic Rice Soils  

Science Journals Connector (OSTI)

Sorption and Degradation of Fipronil in Flooded Anaerobic Rice Soils ... The data predicted that fipronil was subject to rapid, reductive degradation or immediate sorption to the soil and any sorbed fipronil desorbed was reductively degraded. ... The reductive metabolite, fipronil sulfide, accumulated over the 184 day duration of the experiment and sorbed rapidly to the soil, where it accumulated and did not appear to degrade. ...

Gregory Doran; Philip Eberbach; Stuart Helliwell

2009-10-13T23:59:59.000Z

156

Ferroresonant phenomena on 6- to 10-kV substation buses  

Science Journals Connector (OSTI)

Ferroresonance phenomena in distributing networks with an insulated neutral caused by electromagnetic measuring voltage transformers and connecting cables are studied. Procedures for limiting and nonadmission ...

N. A. Kolechitskaya; N. S. Lazarev; R. N. Shul’gara…

2013-04-01T23:59:59.000Z

157

E-Print Network 3.0 - atmospheric phenomena Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

and Dynamical Processes. Summary: . TRANSPORT PHENOMENA Microscopic description of transport processes for particles Random walks and relation... with grey atmospheres Defining...

158

CRAD, Review of Preparedness for Severe Natural Phenomena Events- January 3, 2013  

Energy.gov (U.S. Department of Energy (DOE))

Review of Preparedness for Severe Natural Phenomena Events for DOE/NNSA sites and nuclear facilities (HSS CRAD 45-56, Rev. O)

159

A comparison of thermoelectric phenomena in diverse alloy systems  

SciTech Connect

The study of thermoelectric phenomena in solids provides a wealth of opportunity for exploration of the complex interrelationships between structure, processing, and properties of materials. As thermoelectricity implies some type of coupled thermal and electrical behavior, it is expected that a basic understanding of transport behavior in materials is the goal of such a study. However, transport properties such as electrical resistivity and thermal diffusivity cannot be fully understood and interpreted without first developing an understanding of the material's preparation and its underlying structure. It is the objective of this dissertation to critically examine a number of diverse systems in order to develop a broad perspective on how structure-processing-property relationships differ from system to system, and to discover the common parameters upon which any good thermoelectric material is based. The alloy systems examined in this work include silicon-germanium, zinc oxide, complex intermetallic compounds such as the half-Heusler MNiSn, where M = Ti, Zr, or Hf, and rare earth chalcogenides.

Cook, Bruce

1999-01-01T23:59:59.000Z

160

Advanced computational simulation of flow phenomena associated with orifice meters  

SciTech Connect

This paper presents and discusses results from a series of computational fluid dynamics (CFD) simulations of fluid flow phenomena associated with orifice meters. These simulations were performed using a new, state-of-the-art CFD code developed at Southwest Research Institute. This code is based on new techniques designed to take advantage of parallel computers to increase computational performance and fidelity of simulation results. This algorithm uses a domain decomposition strategy to create grid systems for very complex geometries composed of simpler geometric subregions, allowing for the accurate representation of the fluid flow domain. The domain decomposition technique maps naturally to parallel computer architectures. Here, the concept of message-passing is used to create a parallel algorithm, using the Parallel Virtual Machine (PVM) library. This code is then used to simulate the flow through an orifice meter run consisting of an orifice with a beta ratio of 0.5 and air flowing at a Reynolds number of 91,100. The work discussed in this paper is but the first step in developing a Virtual Metering Research Facility to support research, analysis, and formulation of new standards for metering.

Freitas, C.J. [Southwest Research Inst., San Antonio, TX (United States)

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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161

Stress and phase transformation phenomena in oxide films  

SciTech Connect

In situ optical methods are reviewed for characterization of phase transformation processes and evaluation of residual stress in solution- deposited metastable oxide films. Such low density films most often are deposited as disordered phases making them prone to crystallization and attendant densification when subjected to increased temperature and/or applied pressure. Inherent stress imparted during film deposition and its evolution during the transformation are evaluated from phonon frequency shifts seen in Raman spectra (TiO{sub 2}) or from changes in the laser-induced fluorescence emission spectra for films containing rare earth (Sm{sup +3}:Y{sub 3}Al{sub 5}O{sub 12}) or transition metal (Cr{sup +3}:Al{sub 2}O{sub 3}) dopants. The data in combination with measured increases in line intensities intrinsic to the evolving phase are used to follow crystallization processes in thin films. In general, film deposition parameters are found to influence the crystallite ingrowth kinetics and the magnitude of stress and stress relaxation in the film during the transformation. The utility of these methods to probe crystallization phenomena in oxide films will be addressed.

Exarhos, G.J.; Hess, N.J.

1992-04-01T23:59:59.000Z

162

Quantum Non-Objectivity from Performativity of Quantum Phenomena  

E-Print Network (OSTI)

We analyze the logical foundations of quantum mechanics (QM) by stressing non-objectivity of quantum observables which is a consequence of the absence of logical atoms in QM. We argue that the matter of quantum non-objectivity is that, on the one hand, the formalism of QM constructed as a mathematical theory is self-consistent, but, on the other hand, quantum phenomena as results of experimenter's performances are not self-consistent. This self-inconsistency is an effect of that the language of QM differs much from the language of human performances. The first is the language of a mathematical theory which uses some Aristotelian and Russellian assumptions (e.g., the assumption that there are logical atoms). The second language consists of performative propositions which are self-inconsistent only from the viewpoint of conventional mathematical theory, but they satisfy another logic which is non-Aristotelian. Hence, the representation of quantum reality in linguistic terms may be different: from a mathematical theory to a logic of performative propositions. To solve quantum self-inconsistency, we apply the formalism of non-classical self-referent logics.

Andrei Khrennikov; Andrew Schumann

2014-04-04T23:59:59.000Z

163

Chapter Three - Magnetic Exchange Phenomena Probed by Neutron Scattering  

Science Journals Connector (OSTI)

Abstract Neutron scattering techniques are powerful tools for investigation of magnetic materials and magnetic exchange interactions on the nanoscale. Owing to the weak interaction of the neutron, results are representative of the bulk and not only comprised of surface properties. Nevertheless, due to the high atomic and magnetic contrast, high interface sensitivity is easily achieved. This chapter will review the applicability of neutron scattering techniques to the investigation magnetic exchange interactions based on two examples, interlayer exchange coupling and exchange bias in metallic multilayers. PNR will be employed to study the magnetic state of a Cu0.94Mn0.06/Co multilayer showing a temperature-dependent coupling originating from the dilute magnetic impurities. Exchange bias within mono-stoichiometric FePt3 thin films based on chemical order modulation will be investigated with PNR and diffraction techniques to elucidate the magnetic ordering on nanometer and atomic length scales. During the individual discussion of the phenomena, both interlayer exchange coupling and exchange bias will be reviewed.

Thomas Saerbeck

2014-01-01T23:59:59.000Z

164

Integrated optics and new wave phenomena in optical waveguides  

Science Journals Connector (OSTI)

Research in integrated optics has two goals: One is to apply thin-film technology to the formation of optical devices and circuits. The other is the integration of a large number of optical devices on a small substrate, so forming an optical circuit reminiscent of the integrated circuit in microelectronics. The result is a new breed of optical devices in the form of miniature optical waveguides. They include lasers, modulators, switches, detectors, prisms, lenses, and polarizers, and many of them have efficiencies better than their bulk counterparts. Simple integrated optical circuits have also been constructed, and rapidly advancing semiconductor technology indicates that monolithic integrated optical circuits can readily be developed using GaAs-related compounds. In this paper, we review the state-of-the-art of integrated optics and explore new wave phenomena in optical circuits. The specific topics to be discussed are: light-wave couplers and m-line spectroscopy, refraction and reflection of light in thin films, normal modes of the uniform, the graded and the metal-clad waveguides, optics in tapered films, theory of corrugated waveguides, and more importantly, physics of various thin-film optical devices and the method of the circuit formation.

P. K. Tien

1977-04-01T23:59:59.000Z

165

Quantum Locality?  

SciTech Connect

Robert Griffiths has recently addressed, within the framework of a ‘consistent quantum theory’ (CQT) that he has developed, the issue of whether, as is often claimed, quantum mechanics entails a need for faster-than-light transfers of information over long distances. He argues, on the basis of his examination of certain arguments that claim to demonstrate the existence of such nonlocal influences, that such influences do not exist. However, his examination was restricted mainly to hidden-variable-based arguments that include in their premises some essentially classical-physics-type assumptions that are fundamentally incompatible with the precepts of quantum physics. One cannot logically prove properties of a system by attributing to the system properties alien to that system. Hence Griffiths’ rejection of hidden-variable-based proofs is logically warranted. Griffiths mentions the existence of a certain alternative proof that does not involve hidden variables, and that uses only macroscopically described observable properties. He notes that he had examined in his book proofs of this general kind, and concluded that they provide no evidence for nonlocal influences. But he did not examine the particular proof that he cites. An examination of that particular proof by the method specified by his ‘consistent quantum theory’ shows that the cited proof is valid within that restrictive framework. This necessary existence, within the ‘consistent’ framework, of long range essentially instantaneous influences refutes the claim made by Griffiths that his ‘consistent’ framework is superior to the orthodox quantum theory of von Neumann because it does not entail instantaneous influences. An added section responds to Griffiths’ reply, which cites a litany of ambiguities that seem to restrict, devastatingly, the scope of his CQT formalism, apparently to buttress his claim that my use of that formalism to validate the nonlocality theorem is flawed. But the vagaries that he cites do not upset the proof in question. It is show here in detail why the precise statement of this theorem justifies the specified application of CQT. It is also shown, in response to his challenge, why a putative proof of locality that he has proposed is not valid.

Stapp, Henry

2011-11-10T23:59:59.000Z

166

Materials Degradation Issues in the U.S. High-Level Nuclear Waste Repository  

SciTech Connect

This paper reviews the state-of-the-art understanding of the degradation processes by the Yucca Mountain Project (YMP) with focus on interaction between the in-drift environmental conditions and long-term materials degradation of waste packages and drip shields within the repository system during the first 10,000-years after repository closure. This paper provides an overview of the degradation of the waste packages and drip shields in the repository after permanent closure of the facility. The degradation modes discussed in this paper include aging and phase instability, dry oxidation, general and localized corrosion, stress corrosion cracking, and hydrogen induced cracking of Alloy 22 and titanium alloys. The effects of microbial activity and radiation on the degradation of Alloy 22 and titanium alloys are also discussed. Further, for titanium alloys, the effects of fluorides, bromides, and galvanic coupling to less noble metals are considered. It is concluded that the materials and design adopted will provide sufficient safety margins for at least 10,000-years after repository closure.

K.G. Mon; F. Hua

2005-04-12T23:59:59.000Z

167

Analytical Improvements in PV Degradation Rate Determination  

SciTech Connect

As photovoltaic (PV) penetration of the power grid increases, it becomes vital to know how decreased power output may affect cost over time. In order to predict power delivery, the decline or degradation rates must be determined accurately. For non-spectrally corrected data several complete seasonal cycles (typically 3-5 years) are required to obtain reasonably accurate degradation rates. In a rapidly evolving industry such a time span is often unacceptable and the need exists to determine degradation rates accurately in a shorter period of time. Occurrence of outliers and data shifts are two examples of analytical problems leading to greater uncertainty and therefore to longer observation times. In this paper we compare three methodologies of data analysis for robustness in the presence of outliers, data shifts and shorter measurement time periods.

Jordan, D. C.; Kurtz, S. R.

2011-02-01T23:59:59.000Z

168

Localization on the Landscape and Eternal Inflation  

E-Print Network (OSTI)

We investigate the validity of the assertion that eternal inflation populates the landscape of string theory. We verify that bubble solutions do not satisfy the Klein Gordon equation for the landscape potential. Solutions to the landscape potential within the formalism of quantum cosmology are Anderson localized wavefunctions. Those are inconsistent with inflating bubble solutions. The physical reasons behind the failure of a relation between eternal inflation and the landscape are rooted in quantum phenomena such as interference between wavefunction concentrated around the various vacua in the landscape.

Laura Mersini-Houghton; Malcolm J. Perry

2014-04-22T23:59:59.000Z

169

DSNF AND OTHER WASTE FORM DEGRADATION ABSTRACTION  

SciTech Connect

Several hundred distinct types of DOE-owned spent nuclear fuel (DSNF) may potentially be disposed in the Yucca Mountain repository. These fuel types represent many more types than can be viably individually examined for their effect on the Total System Performance Assessment for the License Application (TSPA-LA). Additionally, for most of these fuel types, there is no known direct experimental test data for the degradation and dissolution of the waste form in repository groundwaters. The approach used in the TSPA-LA model is, therefore, to assess available information on each of 11 groups of DSNF, and to identify a model that can be used in the TSPA-LA model without differentiating between individual codisposal waste packages containing different DSNF types. The purpose of this report is to examine the available data and information concerning the dissolution kinetics of DSNF matrices for the purpose of abstracting a degradation model suitable for use in describing degradation of the DSNF inventory in the Total System Performance Assessment for the License Application. The data and information and associated degradation models were examined for the following types of DSNF: Group 1--Naval spent nuclear fuel; Group 2--Plutonium/uranium alloy (Fermi 1 SNF); Group 3--Plutonium/uranium carbide (Fast Flux Test Facility-Test Fuel Assembly SNF); Group 4--Mixed oxide and plutonium oxide (Fast Flux Test Facility-Demonstration Fuel Assembly/Fast Flux Test Facility-Test Demonstration Fuel Assembly SNF); Group 5--Thorium/uranium carbide (Fort St. Vrain SNF); Group 6--Thorium/uranium oxide (Shippingport light water breeder reactor SNF); Group 7--Uranium metal (N Reactor SNF); Group 8--Uranium oxide (Three Mile Island-2 core debris); Group 9--Aluminum-based SNF (Foreign Research Reactor SNF); Group 10--Miscellaneous Fuel; and Group 11--Uranium-zirconium hydride (Training Research Isotopes-General Atomics SNF). The analyses contained in this document provide an ''upper-limit'' (i.e., instantaneous degradation) model for use in the TSPA-LA model. ''Best-estimate'' models for the degradation of the fuels in each of the DSNF groups are discussed to provide a basis for selecting the upper limit model for use in the TSPA-LA model. The instantaneous degradation model is chosen for use in the TSPA-LA model because the available information shows that the degradation rate of the N Reactor fuel (which constitutes most of the DSNF inventory) is very high and because the available qualified information is insufficient to justify use of a less conservative approach. The commercial spent nuclear fuel model will be used for naval spent nuclear fuel because it has been shown to be conservative for representing naval spent nuclear fuel.

J. CUNNANE

2004-11-19T23:59:59.000Z

170

WAPDEG Analysis of Waste Package and Drip shield Degradation  

SciTech Connect

As directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), an analysis of the degradation of the engineered barrier system (EBS) drip shields and waste packages at the Yucca Mountain repository is developed. The purpose of this activity is to provide the TSPA with inputs and methodologies used to evaluate waste package and drip shield degradation as a function of exposure time under exposure conditions anticipated in the repository. This analysis provides information useful to satisfy ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]) requirements. Several features, events, and processes (FEPs) are also discussed (Section 6.2, Table 15). The previous revision of this report was prepared as a model report in accordance with AP-SIII.10Q, Models. Due to changes in the role of this report since the site recommendation, it no longer contains model development. This revision is prepared as a scientific analysis in accordance with AP-SIII.9Q, ''Scientific Analyses'' and uses models previously validated in (1) ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]); (2) ''General Corrosion and Localized Corrosion of Waste Package Outer Barrier'' (BSC 2004 [DIRS 169984]); and (3) ''General Corrosion and Localized Corrosion of Drip Shield'' (BSC 2004 [DIRS 169845]). The integrated waste package degradation (IWPD) analysis presented in this report treats several implementation-related issues, such as defining the number and size of patches per waste package that undergo stress corrosion cracking; recasting the weld flaw analysis in a form as implemented in the Closure Weld Defects (CWD) software; and, general corrosion rate manipulations (e.g., change of scale in Section 6.3.4). The weld flaw portion of this report takes input from an engineering calculation (BSC 2004 [DIRS 170024]) and uses standard mathematical methods to enable easier implementation. The IWPD analysis also provides guidance on implementation of early failures (importance sampling and multinomial distribution usage). These manipulations are evident from standard scientific practices, approaches, or methods and do not require changes to the previously validated models. The IWPD analysis itself (Section 6.4), not the resultant curves from executing the IWPD analysis presented in Section 6.5 (which are for illustrative purposes), is used directly in total system performance assessment (TSPA). The IWPD analysis simulates general corrosion and stress corrosion cracking of the waste package outer barrier and general corrosion of the drip shield. The effects of igneous and seismic events and localized corrosion on drip shield and waste package performance are not evaluated in this report. The outputs of this report are inputs and methodologies used by TSPA to evaluate waste package and drip shield degradation as a function of exposure time under exposure conditions anticipated in the repository. The analyses presented in this report are for the current repository design (BSC 2004 [DIRS 168489]).

K. Mon

2004-09-29T23:59:59.000Z

171

Color Degradation of Hydrocracked Diesel Fuel  

Science Journals Connector (OSTI)

Color Degradation of Hydrocracked Diesel Fuel ... An important quality standard to be examined is the color of diesels, given the fact that consumers tend to relate a dark colored fuel to low quality fuel, where the dark color comes from the fuels aging. ...

Isabelle Bergeron; Jean-Pierre Charland; Marten Ternan

1999-04-17T23:59:59.000Z

172

WoodChemistry Wood Degradation & Preservation  

E-Print Network (OSTI)

31 WoodChemistry Wood Degradation & Preservation Chemical Utilization of Wood Pulp & Paper and carbohydrates is of considerable interest in connection with a number of issues in wood chemistry, such as the reactions taking place during the formation of wood, the natural molecular weight distribution of lignin

Geldenhuys, Jaco

173

Method of restoring degraded solar cells  

DOE Patents (OSTI)

Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200 C for at least 30 minutes restores their efficiency. 2 figs.

Staebler, D.L.

1983-02-01T23:59:59.000Z

174

Method of restoring degraded solar cells  

DOE Patents (OSTI)

Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200.degree. C. for at least 30 minutes restores their efficiency.

Staebler, David L. (Lawrenceville, NJ)

1983-01-01T23:59:59.000Z

175

Accelerated Degradation of Methyl Iodide by Agrochemicals  

Science Journals Connector (OSTI)

Accelerated Degradation of Methyl Iodide by Agrochemicals ... Integrating the application of certain agrochemicals with soil fumigation provides a novel approach to reduce excessive fumigant emissions. ... This study investigated the potential for several agrochemicals that are commonly used in farming operations, including fertilizers and nitrification inhibitors, to transform MeI in aqueous solution. ...

Wei Zheng; Sharon K. Papiernik; Mingxin Guo; Scott R. Yates

2003-01-01T23:59:59.000Z

176

Uranium Pyrophoricity Phenomena and Prediction (FAI/00-39)  

SciTech Connect

The purpose of this report is to provide a topical reference on the phenomena and prediction of uranium pyrophoricity for the Hanford Spent Nuclear Fuel (SNF) Project with specific applications to SNF Project processes and situations. Spent metallic uranium nuclear fuel is currently stored underwater at the K basins in the Hanford 100 area, and planned processing steps include: (1) At the basins, cleaning and placing fuel elements and scrap into stainless steel multi-canister overpacks (MCOs) holding about 6 MT of fuel apiece; (2) At nearby cold vacuum drying (CVD) stations, draining, vacuum drying, and mechanically sealing the MCOs; (3) Shipping the MCOs to the Canister Storage Building (CSB) on the 200 Area plateau; and (4) Welding shut and placing the MCOs for interim (40 year) dry storage in closed CSB storage tubes cooled by natural air circulation through the surrounding vault. Damaged fuel elements have exposed and corroded fuel surfaces, which can exothermically react with water vapor and oxygen during normal process steps and in off-normal situations, A key process safety concern is the rate of reaction of damaged fuel and the potential for self-sustaining or runaway reactions, also known as uranium fires or fuel ignition. Uranium metal and one of its corrosion products, uranium hydride, are potentially pyrophoric materials. Dangers of pyrophoricity of uranium and its hydride have long been known in the U.S. Department of Energy (Atomic Energy Commission/DOE) complex and will be discussed more below; it is sufficient here to note that there are numerous documented instances of uranium fires during normal operations. The motivation for this work is to place the safety of the present process in proper perspective given past operational experience. Steps in development of such a perspective are: (1) Description of underlying physical causes for runaway reactions, (2) Modeling physical processes to explain runaway reactions, (3) Validation of the method against experimental data, (4) Application of the method to plausibly explain operational experience, and (5) Application of the method to present process steps to demonstrate process safety and margin. Essentially, the logic above is used to demonstrate that runaway reactions cannot occur during normal SNF Project process steps, and to illustrate the depth of the technical basis for such a conclusion. Some off-normal conditions are identified here that could potentially lead to runaway reactions. However, this document is not intended to provide an exhaustive analysis of such cases. In summary, this report provides a ''toolkit'' of models and approaches for analysis of pyrophoricity safety issues at Hanford, and the technical basis for the recommended approaches. A summary of recommended methods appears in Section 9.0.

PLYS, M.G.

2000-10-10T23:59:59.000Z

177

Mass transfer and kinetic phenomena at the nickel hydroxide electrode  

SciTech Connect

Thin-film (10 to 40 nm thickness) nickel hydroxide intercalation electrodes were constructed using an electroprecipitation technique. Cyclic voltammetry, potentiostatic step, and galvanostatic discharge experiments were performed and interpreted in terms of a macroscopic model treating the simultaneous mass transfer, kinetic, and thermodynamic phenomena occurring within the cell. The side reaction, oxygen evolution, exhibited irreversible Tafel behavior, with a proton concentration-dependent exchange current density of 4.5 {times} 10{sup {minus}9} [(c{sub 0} {minus} c)/c{sub 0}] A/cm{sup 2} on pure nickel hydroxide films, and a constant exchange current density of 4.5 {times} 10{sup {minus}9} A/cm{sup 2} on cobalt hydroxide-containing nickel hydroxide films. The apparent anodic transfer coefficient for the oxygen reaction is 0.49 on pure nickel hydroxide films and 0.42 on cobalt hydroxide-containing nickel hydroxide films. The apparent anodic transfer coefficient for the oxygen reaction is 0.49 on pure nickel hydroxide films and 0.42 on cobalt hydroxide-containing nickel hydroxide films. The intercalation reaction is described with a Butler-Volmer-type expression with a large, proton concentration-dependent exchange current density of 9.5 {times} 10{sup {minus}2} [c(c{sub 0} {minus} c)]{sup 1/2} A/cm{sup 2}, and anodic and cathodic apparent transfer coefficients of 0.5 for both electrode types. Here c and c{sub 0} have units of mol/cm{sup 3}. The proton diffusion coefficient in pure nickel hydroxide was found to depend on the proton concentration, with values ranging from 1.2 {times} 10{sup {minus}13} to 1.9 {times} 10{sup {minus}12} cm{sup 2}/s, with a concentration-averaged value of 3.417 {times} 10{sup {minus}13} cm{sup 2}/s. In cobalt hydroxide-containing nickel hydroxide, the values ranged from 2 {times} 10{sup {minus}13} to 1.9 {times} 10{sup {minus}12} cm{sup 2}/s, with a concentration-averaged value of 8.402 {times} 10{sup {minus}13} cm{sup 2}/s.

Ta, K.P.; Newman, J. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.]|[Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

1998-11-01T23:59:59.000Z

178

ENVIRONENTAL DEGRADATION OF ADVANCED AND TRADITIONAL ENGINERING Chapter 14. Forms of Polymer Degradation: Overview  

E-Print Network (OSTI)

ENVIRONENTAL DEGRADATION OF ADVANCED AND TRADITIONAL ENGINERING MATERIALS Chapter 14. Forms more recent. The modern plastics industry is often dated from the mid- nineteenth century, with John Hyatt's invention of celluloid (a synthetic modification of natural cellulose). The first wholly

Roylance, David

179

Characterization of Methane Degradation and Methane-Degrading Microbes in Alaska Coastal Water  

SciTech Connect

The net flux of methane from methane hydrates and other sources to the atmosphere depends on methane degradation as well as methane production and release from geological sources. The goal of this project was to examine methane-degrading archaea and organic carbon oxidizing bacteria in methane-rich and methane-poor sediments of the Beaufort Sea, Alaska. The Beaufort Sea system was sampled as part of a multi-disciplinary expedition (â??Methane in the Arctic Shelfâ? or MIDAS) in September 2009. Microbial communities were examined by quantitative PCR analyses of 16S rRNA genes and key methane degradation genes (pmoA and mcrA involved in aerobic and anaerobic methane degradation, respectively), tag pyrosequencing of 16S rRNA genes to determine the taxonomic make up of microbes in these sediments, and sequencing of all microbial genes (â??metagenomesâ?). The taxonomic and functional make-up of the microbial communities varied with methane concentrations, with some data suggesting higher abundances of potential methane-oxidizing archaea in methane-rich sediments. Sequence analysis of PCR amplicons revealed that most of the mcrA genes were from the ANME-2 group of methane oxidizers. According to metagenomic data, genes involved in methane degradation and other degradation pathways changed with sediment depth along with sulfate and methane concentrations. Most importantly, sulfate reduction genes decreased with depth while the anaerobic methane degradation gene (mcrA) increased along with methane concentrations. The number of potential methane degradation genes (mcrA) was low and inconsistent with other data indicating the large impact of methane on these sediments. The data can be reconciled if a small number of potential methane-oxidizing archaea mediates a large flux of carbon in these sediments. Our study is the first to report metagenomic data from sediments dominated by ANME-2 archaea and is one of the few to examine the entire microbial assemblage potentially involved in anaerobic methane oxidation.

David Kirchman

2011-12-31T23:59:59.000Z

180

Mitigating Performance Degradation of High-Energy Lithium-Ion...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Mitigating Performance Degradation of High-Energy Lithium-Ion Cells Mitigating Performance Degradation of High-Energy Lithium-Ion Cells 2013 DOE Hydrogen and Fuel Cells Program and...

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Temperature dependence of ssrA-tag mediated protein degradation  

E-Print Network (OSTI)

Building synthetic gene networks with highly transient dynamics requires rapid protein degradation. We show that the degradation conferred by two commonly used ssrA tags is highly temperature dependent. Synthetic gene ...

Purcell, Oliver

182

Dynamical features of interference phenomena in the presence of entanglement  

SciTech Connect

A strongly interacting, and entangling, heavy nonrecoiling external particle effects a significant change of the environment. Described locally, the corresponding entanglement event is a generalized electric Aharonov-Bohm effect, which differs from the original one in a crucial way. We propose a gedanken interference experiment. The predicted shift of the interference pattern is due to a self-induced or ''private'' potential difference experienced while the particle is in vacuum. We show that all nontrivial Born-Oppenheimer potentials are ''private'' potentials. We apply the Born-Oppenheimer approximation to interference states. Using our approach, we calculate the relative phase of the external heavy particle as well as its uncertainty throughout an interference experiment or entanglement event. We thus complement the Born-Oppenheimer approximation for interference states.

Kaufherr, T. [Tel Aviv University, School of Physics and Astronomy, Tel Aviv 69978 (Israel); Physics Department, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Aharonov, Y. [Tel Aviv University, School of Physics and Astronomy, Tel Aviv 69978 (Israel); Chapman University, Schmid College of Sciences, Orange, California 92866 (United States); Nussinov, S. [Tel Aviv University, School of Physics and Astronomy, Tel Aviv 69978 (Israel); Popescu, S. [H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TK (United Kingdom); Tollaksen, J. [Chapman University, Schmid College of Sciences, Orange, California 92866 (United States)

2011-05-15T23:59:59.000Z

183

Organic solar cell degradation probed by the nanosecond photoresponse  

Science Journals Connector (OSTI)

We measure the transient electrical response of small organic solar cells illuminated with nanosecond light pulses during degradation....

S. W. Kettlitz; S. Valouch; U. Lemmer

2010-06-01T23:59:59.000Z

184

Water and UV degradable lactic acid polymers  

DOE Patents (OSTI)

A water and UV light degradable copolymer of monomers of lactic acid and a modifying monomer were selected from the class consisting of ethylene and polyethylene glycols, propylene and polypropylene glycols, P-dioxanone, 1,5 dioxepan-2-one, 1,4 -oxathialan-2-one, 1,4-dioxide and mixtures. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide where the high molecular weight polyethylene oxide is present in the range of from about 2% by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures to an agricultural site is also disclosed.

Bonsignore, P.V.; Coleman, R.D.

1994-11-01T23:59:59.000Z

185

Water and UV degradable lactic acid polymers  

DOE Patents (OSTI)

A water and UV light degradable copolymer of monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene and polyethylene glycols, propylene and polypropylene glycols, P-dioxanone, 1,5 dioxepan-2-one, 1,4 -oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2% by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.

Bonsignore, Patrick V. (Joliet, IL); Coleman, Robert D. (Wheaton, IL)

1994-01-01T23:59:59.000Z

186

Water and UV degradable lactic acid polymers  

DOE Patents (OSTI)

A water and UV light degradable copolymer is described made from monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene glycol, propylene glycol, P-dioxanone, 1,5 dioxepan-2-one, 1,4-oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2 by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.

Bonsignore, P.V.; Coleman, R.D.

1996-10-08T23:59:59.000Z

187

Water and UV degradable lactic acid polymers  

DOE Patents (OSTI)

A water and UV light degradable copolymer of monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene glycol, propylene glycol, P-dioxanone, 1,5 dioxepan-2-one, 1,4-oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2 by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.

Bonsignore, Patrick V. (Joliet, IL); Coleman, Robert D. (Wheaton, IL)

1996-01-01T23:59:59.000Z

188

Elastomer degradation sensor using a piezoelectric material  

DOE Patents (OSTI)

A method and apparatus for monitoring the degradation of elastomeric materials is provided. Piezoelectric oscillators are placed in contact with the elastomeric material so that a forced harmonic oscillator with damping is formed. The piezoelectric material is connected to an oscillator circuit,. A parameter such as the resonant frequency, amplitude or Q value of the oscillating system is related to the elasticity of the elastomeric material. Degradation of the elastomeric material causes changes in its elasticity which, in turn, causes the resonant frequency, amplitude or Q of the oscillator to change. These changes are monitored with a peak height monitor, frequency counter, Q-meter, spectrum analyzer, or other measurement circuit. Elasticity of elastomers can be monitored in situ, using miniaturized sensors.

Olness, Dolores U. (Livermore, CA); Hirschfeld, deceased, Tomas B. (late of Livermore, CA)

1990-01-01T23:59:59.000Z

189

Why sequence cellulose degrading fungus Amanita thiersii?  

NLE Websites -- All DOE Office Websites (Extended Search)

sequence cellulose degrading fungus Amanita thiersii? sequence cellulose degrading fungus Amanita thiersii? Amanita thiersii is a white, sticky mushroom that obtains its carbon by decomposing grasses, playing a role in the terrestrial carbon cycle. The fungus is commonly found in grasslands throughout the central United States and grows in grassy areas away from trees, often seen on lawns after the rain. By sequencing A. thiersii's genome, researchers hope increase the list of fungi that might provide enzymes that can be used to commercialize the production of cellulosic biofuel, which falls in with the U.S. Department of Energy's mission to develop clean energy, by potentially offering a more cost-effective method of breaking down lignocellulose in plant cell walls. Because the fungus is found in regions where the biomass is high in

190

Degradation of Materials in Combustion Environments  

E-Print Network (OSTI)

and oxide structural ceramics materials. involved formation of new liquid,glass, and solid phases. which resulted in loss of structural This paper briefly reviews the contents of 23 integrity. Destructi ve stresses a!iSOc i ated wi th ORNL reports... furnaces are During the past decade workers at Oak Ridge being used to study the effects of specific chemical National Laboratory (ORNL) and elsewhere have species on metallic and ceramic materials. Tests investigated the degradation of refractory...

Robbins, J. M.; Federer, J. I.; Parks, W. P. Jr.; Reid, J. S.

191

Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil  

E-Print Network (OSTI)

Characterization of Trapped Lignin-Degrading Microbes inCharacterization of Trapped Lignin-Degrading Microbes inCharacterization of Trapped Lignin-Degrading Microbes in

DeAngelis, Kristen

2012-01-01T23:59:59.000Z

192

E-Print Network 3.0 - aromatic hydrocarbon-degrading bacteria...  

NLE Websites -- All DOE Office Websites (Extended Search)

ydrocarbonDegradation It was hypothesized... aromatic hydrocarbon degradation. Hypothesis Test Result Groundwater stimulates Fe(lll) reduction Cell... Hydrocarbon Degradation At...

193

Degradation of nuclear oncoproteins by the ubiquitin system in vitro  

Science Journals Connector (OSTI)

Degradation of nuclear oncoproteins by the ubiquitin...common to all five of the nuclear oncoproteins described...requirement for metabolic energy (reviewed in ref. 13...protein degraded in an energy-dependent manner...ubiquitin-dependent degradation of the nuclear oncoproteins studied...

A Ciechanover; J A DiGiuseppe; B Bercovich; A Orian; J D Richter; A L Schwartz; G M Brodeur

1991-01-01T23:59:59.000Z

194

THE AUDIO DEGRADATION TOOLBOX AND ITS APPLICATION TO ROBUSTNESS EVALUATION  

E-Print Network (OSTI)

THE AUDIO DEGRADATION TOOLBOX AND ITS APPLICATION TO ROBUSTNESS EVALUATION Matthias Mauch Sebastian.ewert}@eecs.qmul.ac.uk ABSTRACT We introduce the Audio Degradation Toolbox (ADT) for the controlled degradation of audio signals, and propose its usage as a means of evaluating and comparing the ro- bustness of audio processing algorithms

Mauch, Matthias

195

Oxidative Degradation of BPA Using TiO2 in Water, and Transition of Estrogenic Activity in the Degradation Pathways  

Science Journals Connector (OSTI)

The oxidative degradation behavior of bisphenol A (BPA) using titanium dioxide (TiO2...) in water was investigated. The main purposes were to clarify the relationship with estrogenic activity from the degradation...

Kei Nomiyama; Teiji Tanizaki; Toyokazu Koga…

2007-01-01T23:59:59.000Z

196

Staining of in vivo subsurface degradation in dental composites with silver nitrate  

SciTech Connect

A previously reported technique for staining areas of degradation in dental composite restorations was evaluated in 51 removed restorations. The staining reagent was silver nitrate, which penetrated the degraded subsurface as ionic silver and was subsequently developed into colored deposits of metallic silver. Several artefacts were recognized that resulted in an apparent image of subsurface stain. Most importantly, the presence of a layer of adsorbed silver on the edge of the specimen exaggerated the extent of staining. In order for the true depth of stain to be determined, thin sections of the materials should first be examined with a stereomicroscope to distinguish any contribution from adsorbed silver on the specimen edge. With this regimen, no stain was present in 41% of the restorations, and in a further 30%, the depth of stain was less than 50 microns. In two composites, the depth of stain was greater than 900 microns, and in a number of specimens, localized stain was found in association with attrition scars. Energy-dispersive x-ray analysis indicated that the amount of silver present in the degraded layers was very small. Overall, the results indicated that the staining technique is useful in the study of composite degradation.

Mair, L.H. (Univ. of Liverpool (England))

1991-03-01T23:59:59.000Z

197

The Adequacy of DOE Natural Phenomena Hazards Performance Goals from an Accident Analysis Perspective  

Energy.gov (U.S. Department of Energy (DOE))

The Adequacy of DOE Natural Phenomena Hazards Performance Goals from an Accident Analysis Perspective Jeff Kimball Defense Nuclear Facilities Safety Board Staff Department of Energy NPH Conference October 26, 2011

198

PHYSICS OF FLUIDS 26, 052001 (2014) Capturing non-equilibrium phenomena in rarefied  

E-Print Network (OSTI)

PHYSICS OF FLUIDS 26, 052001 (2014) Capturing non-equilibrium phenomena in rarefied polyatomic: 142.104.86.60 On: Mon, 05 May 2014 20:27:14 #12;052001-2 B. Rahimi and H. Struchtrup Phys. Fluids 26

Struchtrup, Henning

199

Photo-Chemical Researches. Part II. Phenomena of Photo-Chemical Induction  

Science Journals Connector (OSTI)

1 January 1857 research-article Photo-Chemical Researches. Part II. Phenomena of Photo-Chemical Induction Professor Bunsen Henry Enfield Roscoe The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Philosophical...

1857-01-01T23:59:59.000Z

200

Photo-Chemical Researches. -- Part II. Phenomena of Photo-Chemical Induction.  

Science Journals Connector (OSTI)

1856-1857 research-article Photo-Chemical Researches. -- Part II. Phenomena of Photo-Chemical Induction. Prof. Bunsen Henry Enfield Roscoe The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings...

1856-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Dissipative particle dynamics simulation of wettability alternation phenomena in the chemical flooding process  

Science Journals Connector (OSTI)

Wettability alternation phenomena is considered one of the most important enhanced oil recovery (EOR) mechanisms in the chemical flooding process and induced by the adsorption of ... external forces on the fluid ...

Xiaobo Li; Yuewu Liu; Jianfei Tang; Shujiao Li

2009-10-01T23:59:59.000Z

202

Models of fragmentation phenomena based on the symmetric group S sub n and combinational analysis  

SciTech Connect

Various models for fragmentation phenomena are developed using methods from permutation groups and combinational analysis. The appearance and properties of power laws in these models are discussed. Various exactly soluble cases are studied.

Mekjian, A.Z. (Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory); Lee, S.J. (Rutgers--the State Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy)

1991-01-29T23:59:59.000Z

203

Models of fragmentation phenomena based on the symmetric group S{sub n} and combinational analysis  

SciTech Connect

Various models for fragmentation phenomena are developed using methods from permutation groups and combinational analysis. The appearance and properties of power laws in these models are discussed. Various exactly soluble cases are studied.

Mekjian, A.Z. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory; Lee, S.J. [Rutgers--the State Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy

1991-01-29T23:59:59.000Z

204

Nonlinear Acoustic Phenomena in Subsurface Bubble Layers and its Usage for Bubble Measurements  

Science Journals Connector (OSTI)

This paper contains a brief review of our recent theoretical and experimental investigations of nonlinear acoustic phenomena in sub-surface bubble layers produced by breaking waves and results concerning linear a...

A. M. Sutin

1992-01-01T23:59:59.000Z

205

Understanding some simple phenomena in thermoacoustics with applications to acoustical heat engines  

Science Journals Connector (OSTI)

Thermoacoustical phenomena have a long history and are frequently characterized by great complexity. In the present paper we describe how by the use of suitable acoustical structures the phenomena can both be simplified and readily demonstrated. A heuristic discussion is emphasized which we hope will be useful in teaching the principles. The qualities of certain model apparatus that demonstrate acoustically stimulated entropy flow a thermally driven acoustic oscillator and an acoustically driven refrigerator are also presented in semiquantitative detail.

John Wheatley; T. Hofler; G. W. Swift; A. Migliori

1985-01-01T23:59:59.000Z

206

A Distributed Electrochemistry Modeling Tool for Simulating SOFC Performance and Degradation  

SciTech Connect

This report presents a distributed electrochemistry (DEC) model capable of investigating the electrochemistry and local conditions with the SOFC MEA based on the local microstructure and multi-physics. The DEC model can calculate the global current-voltage (I-V) performance of the cell as determined by the spatially varying local conditions through the thickness of the electrodes and electrolyte. The simulation tool is able to investigate the electrochemical performance based on characteristics of the electrode microstructure, such as particle size, pore size, electrolyte and electrode phase volume fractions, and triple-phase-boundary length. It can also investigate performance as affected by fuel and oxidant gas flow distributions and other environmental/experimental conditions such as temperature and fuel gas composition. The long-term objective for the DEC modeling tool is to investigate factors that cause electrode degradation and the decay of SOFC performance which decrease longevity.

Recknagle, Kurtis P.; Ryan, Emily M.; Khaleel, Mohammad A.

2011-10-13T23:59:59.000Z

207

CSNF WASTE FORM DEGRADATION: SUMMARY ABSTRACTION  

SciTech Connect

The purpose of this model report is to describe the development and validation of models that can be used to calculate the release of radionuclides from commercial spent nuclear fuel (CSNF) following a hypothetical breach of the waste package and fuel cladding in the repository. The purpose also includes describing the uncertainties associated with modeling the radionuclide release for the range of CSNF types, exposure conditions, and durations for which the radionuclide release models are to be applied. This document was developed in accordance with Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package (BSC 2004 [DIRS 169944]). This document considers radionuclides to be released from CSNF when they are available for mobilization by gas-phase mass transport, or by dissolution or colloid formation in water that may contact the fuel. Because other reports address limitations on the dissolved and colloidal radionuclide concentrations (BSC 2004 [DIRS 169944], Table 2-1), this report does not address processes that control the extent to which the radionuclides released from CSNF are mobilized and transported away from the fuel either in the gas phase or in the aqueous phase as dissolved and colloidal species. The scope is limited to consideration of degradation of the CSNF rods following an initial breach of the cladding. It considers features of CSNF that limit the availability of individual radionuclides for release into the gaseous or aqueous phases that may contact the fuel and the processes and events expected to degrade these CSNF features. In short, the purpose is to describe the characteristics of breached fuel rods and the degradation processes expected to influence radionuclide release.

J.C. CUNNANE

2004-08-31T23:59:59.000Z

208

Cyanide-degrading enzymes for bioremediation  

E-Print Network (OSTI)

............................. 27 Figure 7 Ability of N. crassa, G. sorghi, G. zeae, and A. nidulans to Degrade KCN and Cyanide in Waste-Water Samples Containing High Concentrations of Silver or Copper............................. 31 ix LIST OF TABLES...H 7.4), 100mM NaCl, 12.5mM imidazole (pH 7.4), and 1mg mL-1 17 lysozyme. After incubation on ice for 15 minutes, cells were lysed by five cycles of freezing at -80 oC, and thawing. Viscous DNA was removed by the addition of a crude preparation...

Basile, Lacy Jamel

2008-10-10T23:59:59.000Z

209

An attempt to minimize the temperature gradient along a plug-flow methane/steam reforming reactor by adopting locally controlled heating zones  

Science Journals Connector (OSTI)

Plug flow reactors are very common in the chemical process industry, including methane/steam reforming applications. Their operation presents many challenges, such as a strong dependence of temperature and composition distribution on the inlet conditions. The strongly endothermic methane/steam reforming reaction might result in a temperature drop at the inlet of the reactor and consequently the occurrence of large temperature gradients. The strongly non-uniform temperature distribution due to endothermic chemical reaction can have tremendous consequences on the operation of the reactor, such as catalyst degradation, undesired side reactions and thermal stresses. To avoid such unfavorable conditions, thermal management of the reactor becomes an important issue. To carry out thermal management properly, detailed modeling and corresponding numerical analyses of the phenomena occurring inside the reforming system is required. This paper presents experimental and numerical studies on the methane/steam reforming process inside a plug-flow reactor. To optimize the reforming reactors, detailed data about the entire reforming process is required. In this study the kinetics of methane/steam reforming on the Ni/YSZ catalyst was experimentally investigated. Measurements including different thermal boundary conditions, the fuel flow rate and the steam- to-methane ratios were performed. The reforming rate equation derived from experimental data was used in the numerical model to predict gas composition and temperature distribution along the steam-reforming reactor. Finally, an attempt was made to control the temperature distribution by adopting locally controlled heating zones.

M Mozdzierz; G Brus; A Sciazko; Y Komatsu; S Kimijima; J S Szmyd

2014-01-01T23:59:59.000Z

210

Trials of flexible pipe in sour service reveal degradation  

SciTech Connect

Field trials on flexible pipe offshore Qatar have shown that, under sour conditions, the layered, composite material can suffer severe degradation leading to failure. The failure demonstrates the significant effects of stress level, environmental aggressiveness, and localized hard zones in promoting sulfide stress cracking. Permeability of the sour gas through the composite layer of the flexible pipe resulted in varying degrees of sulfide attack and hydrogen embrittlement, depending on the susceptibility of the multilayered material. In the trials, the material was used as a gas-lift line in a sour-oil field in the Arabian Gulf. Flexible pipes have been used successfully for transporting methanol, benzene, and gas condensates in wet sweet environments at temperatures of up to 80 C. Little or no information, however, has been available as to its corrosion resistance in sour-service wells containing 6% CO{sub 2} with 3% H{sub 2}S partial pressures and at moderate temperatures. The paper discusses an underwater survey to evaluate the damage, visual inspection, mechanical tests, metallographic exam, and trial results.

Al-Maslamani, M.J. [Qatar General Petroleum Corp., Doha (Qatar)

1996-11-04T23:59:59.000Z

211

Biocarrier composition for and method of degrading pollutants  

DOE Patents (OSTI)

The present invention relates to biocarrier compositions that attract and bond pollutant-degrading antigens that will degrade the pollutants. Biocarriers are known generally as a variety of inert or semi-inert compounds or structures having the ability to sequester (attract), hold and biomagnify (enhance) specific microorganisms within their structure. Glass or polystyrene beads are the most well known biocarriers. The biocarrier, which is preferably in the form of glass microspheres, is coated with an antibody or group of antibodies that attract and react specifically with certain pollutant-degrading antigens. The antibody, once bonded to the biocarrier, is used by the composition to attract and bond those pollutant-degrading antigens. Each antibody is specific for an antigen that is specific for a given pollutant. The resulting composition is subsequently exposed to an environment contaminated with pollutants for degradation. In the preferred use, the degrading composition is formed and then injected directly into or near a plume or source of contamination.

Fliermans, C.B.

1994-01-01T23:59:59.000Z

212

HYDRIDE-RELATED DEGRADATION OF SNF CLADDING UNDER REPOSITORY CONDITIONS  

SciTech Connect

The purpose and scope of this analysis/model report is to analyze the degradation of commercial spent nuclear fuel (CSNF) cladding under repository conditions by the hydride-related metallurgical processes, such as delayed hydride cracking (DHC), hydride reorientation and hydrogen embrittlement, thereby providing a better understanding of the degradation process and clarifying which aspects of the process are known and which need further evaluation and investigation. The intended use is as an input to a more general analysis of cladding degradation.

K. McCoy

2000-12-12T23:59:59.000Z

213

Intracellular protein degradation in cultured rat muscle cells  

E-Print Network (OSTI)

1982 Major Subject: Biochemistry INTRACELLULAR PROTEIN DEGRADATION IN CULTURED RAT MUSCLE CELLS A Thesis by GWENDOLYN BETH MILLER Approved as to style and content by: hairman of Committee) p I 'P) (Member) (M r) (Head of Department) August... 1982 "BOGS-'. 4( 3 3q ABSTRACT Intracellular Protein Degradation in Cultured Rat Muscle Cells (August 1982) Gwendolyn Beth Miller, B. S. , Texas Asm Dniversity Chairman of Advisory Committee: Dr. J. martyn Gunn Intra:elMlar protein degradation...

Miller, Gwendolyn Beth

1982-01-01T23:59:59.000Z

214

Multiple Syntrophic Interactions in a Terephthalate-Degrading Methanogenic Consortium  

E-Print Network (OSTI)

Pol, L.W.H. , and Lettinga, G. (1999) Anaerobic degradationRebac, S. , and Lettinga, G. (1997) High-rate anaerobic

Lykidis, Athanasios

2012-01-01T23:59:59.000Z

215

Physical Ageing by Ultra Violet Degradation of Recycled Polyolefin Blends.  

E-Print Network (OSTI)

??This thesis covers the investigation of the weathering behaviour of mixed waste plastics. It includes a review of the literature on polymer degradation mechanisms with… (more)

Julienne Carol, Attwood

2007-01-01T23:59:59.000Z

216

Deciphering Active Estrogen-Degrading Microorganisms in Bioreactors  

E-Print Network (OSTI)

in biological wastewater treatment processes. This dissertation investigated factors affecting estrogen biodegradation in bioreactors. Specifically, research efforts were placed on characterization of several bacterial estrogen degraders (model strains...

Roh, Hyung Keun

2010-10-12T23:59:59.000Z

217

Model Compound Studies of Fuel Cell Membrane Degradation  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on Model Compound Studies of Fuel Cell Membrane Degradation to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.

218

Methods for enhancing the degradation or conversion of cellulosic material  

DOE Patents (OSTI)

The present invention relates to methods for degrading or converting a cellulosic material and for producing a substance from a cellulosic material.

Harris, Paul (Carnation, WA) Rey, Michael (Davis, CA); Ding, Hanshu (Davis, CA)

2009-10-27T23:59:59.000Z

219

Thermomechanical Constitutive Modeling of Viscoelastic Materials undergoing Degradation  

E-Print Network (OSTI)

viscoelastic uid that shows instantaneous elas- ticity in creep. : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 3 Illustration of the various degradation mechanisms on a polyimide (that shows viscoelastic solid-like behavior...

Karra, Satish

2012-07-16T23:59:59.000Z

220

Outdoor PV Module Degradation of Current-Voltage Parameters: Preprint  

SciTech Connect

Photovoltaic (PV) module degradation rate analysis quantifies the loss of PV power output over time and is useful for estimating the impact of degradation on the cost of energy. An understanding of the degradation of all current-voltage (I-V) parameters helps to determine the cause of the degradation and also gives useful information for the design of the system. This study reports on data collected from 12 distinct mono- and poly-crystalline modules deployed at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. Most modules investigated showed < 0.5%/year decrease in maximum power due to short-circuit current decline.

Smith, R. M.; Jordan, D. C.; Kurtz, S. R.

2012-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Using Thermally-Degrading, Partitioning, and Nonreactive Tracers...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Partitioning, and Nonreactive Tracers to Determine Temperature Distribution and FractureHeat Transfer Surface Area in Geothermal Reservoirs Using Thermally-Degrading,...

222

Are Ventilation Filters Degrading Indoor Air Quality in California Classrooms?  

E-Print Network (OSTI)

air conditioning  IAQ: Indoor air quality  LBNL: Lawrence Degrading Indoor Air Quality in California Classrooms? HDEGRADING INDOOR AIR QUALITY IN CALIFORNIA CLASSROOMS?

Fisk, Michael G. Apte and William J.

2009-01-01T23:59:59.000Z

223

Waste Form Degradation Model Integration for Engineered Materials Performance  

Energy.gov (U.S. Department of Energy (DOE))

The collaborative approach to the glass and metallic waste form degradation modeling activities includes process model development (including first-principles approaches) and model integration—both...

224

Fundamental investigation of Duct/ESP phenomena: 1. 7 MW pilot parametric testing results  

SciTech Connect

Radian Corporation was contracted to investigate duct injection and electrostatic precipitator phenomena in a 1.7-MW pilot plant constructed for this test program. This study was an attempt to resolve previous problems and to answer remaining questions with the technology using an approach which concentrated on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of the duct injection process to an existing ESP particulate collection device. (VC)

McGuire, L.M.; Brown, C.A.

1991-07-22T23:59:59.000Z

225

Fermi coordinates and modified Franklin transformation : A comparative study on rotational phenomena  

E-Print Network (OSTI)

Applying a relativistic rotational transformation to study and analyze rotational phenomena, instead of the rotational transformations based on consecutive Lorentz transformations and Fermi coordinates, leads to different predictions. In this article after a comparative study between Fermi metric of a uniformly rotating observer and the spacetime metric in a rotating frame obtained through the modified Franklin transformation, we consider rotational phenomena including transverse Doppler effect and Sagnac effect in both formalisms and compare their predictions. We also discuss length measurements in the two formalisms.

M. Nouri-Zonoz; H. Ramezani-Aval

2014-03-29T23:59:59.000Z

226

Fermi coordinates and modified Franklin transformation : A comparative study on rotational phenomena  

E-Print Network (OSTI)

Applying a relativistic rotational transformation to study and analyze rotational phenomena, instead of the rotational transformations based on consecutive Lorentz transformations and Fermi coordinates, leads to different predictions. In this article after a comparative study between Fermi metric of a uniformly rotating observer and the spacetime metric in a rotating frame obtained through the modified Franklin transformation, we consider rotational phenomena including transverse Doppler effect and Sagnac effect in both formalisms and compare their predictions. We also discuss length measurements in the two formalisms.

Nouri-Zonoz, M

2014-01-01T23:59:59.000Z

227

Mesoscopic modeling of multi-physicochemical transport phenomena in porous media  

SciTech Connect

We present our recent progress on mesoscopic modeling of multi-physicochemical transport phenomena in porous media based on the lattice Boltzmann method. Simulation examples include injection of CO{sub 2} saturated brine into a limestone rock, two-phase behavior and flooding phenomena in polymer electrolyte fuel cells, and electroosmosis in homogeneously charged porous media. It is shown that the lattice Boltzmann method can account for multiple, coupled physicochemical processes in these systems and can shed some light on the underlying physics occuning at the fundamental scale. Therefore, it can be a potential powerful numerical tool to analyze multi-physicochemical processes in various energy, earth, and environmental systems.

Kang, Qinjin [Los Alamos National Laboratory; Wang, Moran [Los Alamos National Laboratory; Mukherjee, Partha P [Los Alamos National Laboratory; Lichtner, Peter C [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

228

Genomics of wood-degrading fungi  

Science Journals Connector (OSTI)

Abstract Woody plants convert the energy of the sun into lignocellulosic biomass, which is an abundant substrate for bioenergy production. Fungi, especially wood decayers from the class Agaricomycetes, have evolved ways to degrade lignocellulose into its monomeric constituents, and understanding this process may facilitate the development of biofuels. Over the past decade genomics has become a powerful tool to study the Agaricomycetes. In 2004 the first sequenced genome of the white rot fungus Phanerochaete chrysosporium revealed a rich catalog of lignocellulolytic enzymes. In the decade that followed the number of genomes of Agaricomycetes grew to more than 75 and revealed a diversity of wood-decaying strategies. New technologies for high-throughput functional genomics are now needed to further study these organisms.

Robin A. Ohm; Robert Riley; Asaf Salamov; Byoungnam Min; In-Geol Choi; Igor V. Grigoriev

2014-01-01T23:59:59.000Z

229

Characterization of thermally degraded energetic materials  

SciTech Connect

Characterization of the damage state of a thermally degraded energetic material (EM) is a critical first step in understanding and predicting cookoff behavior. Unfortunately, the chemical and mechanical responses of heated EMs are closely coupled, especially if the EM is confined. The authors have examined several EMs in small-scale experiments (typically 200 mg) heated in both constant-volume and constant-load configurations. Fixtures were designed to minimize free volume and to contain gas pressures to several thousand psi. The authors measured mechanical forces or displacements that correlated to thermal expansion, phase transitions, material creep and gas pressurization as functions of temperature and soak time. In addition to these real-time measurements, samples were recovered for postmortem examination, usually with scanning electron microscopy (SEM) and chemical analysis. The authors present results on EMs (HMX and TATB), with binders (e.g., PBX 9501, PBX 9502, LX-14) and propellants (Al/AP/HTPB).

Renlund, A.M.; Miller, J.C.; Trott, W.M.; Erickson, K.L.; Hobbs, M.L.; Schmitt, R.G.; Wellman, G.W.; Baer, M.R.

1997-12-31T23:59:59.000Z

230

Recovery of electric resistance degraded by electromigration  

Science Journals Connector (OSTI)

Electric resistance degraded by electromigration at low temperatures is investigated by sweeping temperatures up to 400 K at a constant rate. Recovery (decrease) of the resistance is found and a first?order reaction model is applied to evaluate the activation energyspectra for this recovery. The energy spectra are found to broaden up to 1.1 eV. A comparison of the spectra with both the activation energy for the motion of vacancies and the spectra for as?deposited films prepared by electron?beam evaporation and dc sputtering indicates that the recovery comprises multienergy processes. The relaxation of mechanical stress gradients built up during the dc stress tests the relief of microstructural changes by bulk diffusion involving the cooperative motion of large groups of atoms and the formation of vacancy–hydrogen complexes as intermediates are discussed as possible factors contributing to the broad activation energyspectra of the recovery.

Shin?ichi Ohfuji; Mitsuo Tsukada

1995-01-01T23:59:59.000Z

231

Local energy landscape in a simple liquid  

Science Journals Connector (OSTI)

It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure that defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly the effect of temperature and history. However, because of the highly multidimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL), which is limited in phase space, and demonstrate its usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest-neighbor atoms. The excitation in the LEL corresponds to the so-called ?-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.

T. Iwashita and T. Egami

2014-11-26T23:59:59.000Z

232

Local Energy Landscape in a Simple Liquid  

E-Print Network (OSTI)

It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure which defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly on the effect of temperature and history. However, because of the highly multi-dimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL) which is limited in phase space, and demonstrate its usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest neighbor atoms. The excitations in the LEL corresponds to the so-called beta-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.

Takuya Iwashita; Takeshi Egami

2014-10-31T23:59:59.000Z

233

Degraded states, novel ecosystems, or reconfigured landscapes  

E-Print Network (OSTI)

. Specify state-and-transition model for ecological sites T1, T2--local management drivers; R1--restoration Changing management Stationarity or constant change? Disturbance/feedbacks Changes in survival and transition models vs. alternative regime models 2. How do we gather evidence for the models? broader spatial

234

Cloning, Expression, and Cell Surface Localization of Paenibacillus sp. Strain W-61 Xylanase 5, a Multidomain Xylanase  

Science Journals Connector (OSTI)

...no substantial xylan-binding activity. Cell surface localization of...Xyn5 to the cell surface of the bacterium...neighboring b-1,4-xylans by Xyn5 and the...expression, and cell surface localization of...have shown that a xylan-degrading bacterium...

Yasuko Ito; Toshio Tomita; Narayan Roy; Akito Nakano; Noriko Sugawara-Tomita; Seiji Watanabe; Naoko Okai; Naoki Abe; Yoshiyuki Kamio

2003-12-01T23:59:59.000Z

235

Review of Preparedness for Severe Natural Phenomena Events at the Paducah Site, April 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

Independent Oversight Review of Independent Oversight Review of Preparedness for Severe Natural Phenomena Events at the Paducah Site May 2011 April 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose................................................................................................................................................ 1 2.0 Scope................................................................................................................................................... 1 3.0 Background ......................................................................................................................................... 2

236

Independent Oversight Review of Preparedness for Severe Natural Phenomena Events at the Hanford Site, September 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

of of Preparedness for Severe Natural Phenomena Events at the Hanford Site May 2011 September 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose................................................................................................................................................ 1 2.0 Scope................................................................................................................................................... 1 3.0 Background ......................................................................................................................................... 2 4.0 Methodology ....................................................................................................................................... 3

237

Transport phenomena in metal-halide lamps a poly-diagnostic study  

E-Print Network (OSTI)

/ spectroscopie. Subject headings: gas discharges / metal-halide lamps / plasma diagnostics / plasma properties-halide arc lamps . . . . . . . . . . . 7 1.3 Scope of ThesisTransport phenomena in metal-halide lamps a poly-diagnostic study Tanya Nimalasuriya #12;Copyright

Eindhoven, Technische Universiteit

238

NEST Scientific Report 2007-2009 Transport phenomena in self-assembled nanowires  

E-Print Network (OSTI)

NEST Scientific Report 2007-2009 Transport phenomena in self-assembled nanowires 21 S elf incompatible materials can be combined into advanced ­ in some cases unprecedented ­ nanostructures and charge transport in self-assembled structures as well as Josephson coupling in devices combining

Abbondandolo, Alberto

239

EXPERIENCE USING PHENOMENA IDENTIFICATION AND RANKING TECHNIQUE (PIRT) FOR NUCLEAR ANALYSIS.  

SciTech Connect

THE PHENOMENA IDENTIFICATION AND RANKING TECHNIQUE (PIRT) IS A SYSTEMATIC WAY OF GATHERING INFORMATION FROM EXPERTS ON A SPECIFIC SUBJECT, AND RANKING THE IMPORTANCE OF THE INFORMATION, IN ORDER TO MEET SOME DECISION MAKING OBJECTIVE. IT HAS BEEN APPLIED TO MANY NUCLEAR TECHONLOGY ISSUES INCLUDING NUCLEAR ANALYSIS IN ORDER TO HELP GUIDE RESEARCH OR DEVELOP REGULATORY REQUIREMENTS.

DIAMOND, DAVID J.

2006-06-30T23:59:59.000Z

240

Wave Turbulence in Superfluid 4 Energy Cascades, Rogue Waves & Kinetic Phenomena  

E-Print Network (OSTI)

Outline Wave Turbulence in Superfluid 4 He: Energy Cascades, Rogue Waves & Kinetic Phenomena Conference, Chernogolovka, 3 August 2009 McClintock Efimov Ganshin Kolmakov Mezhov-Deglin Wave Turbulence in Superfluid 4 He #12;Outline Outline 1 Introduction Motivation 2 Modelling wave turbulence Need for models

Fominov, Yakov

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

MODELLING OF TRANSPORT PHENOMENA FOR THE HYPERSONIC STAGNATION POINT HEAT TRANSFER PROBLEM  

E-Print Network (OSTI)

MODELLING OF TRANSPORT PHENOMENA FOR THE HYPERSONIC STAGNATION POINT HEAT TRANSFER PROBLEM A to vibrational mode el refers to electronic mode Introduction One of the major problems encountered in hypersonic. The hypersonic flow about such surfaces is charac­ terized by a strong bow shock, which converts the major part

242

Experimental studies of anode sheath phenomena in a Hall thruster discharge  

E-Print Network (OSTI)

Experimental studies of anode sheath phenomena in a Hall thruster discharge L. Dorf,a Y. Raitses-attracting anode sheaths in a Hall thruster were characterized by measuring the plasma potential with biased in the near-anode region of a Hall thruster with clean and dielectrically coated anodes are identified

243

A unifying mechanical equation with applications to non-holonomic constraints and dissipative phenomena  

E-Print Network (OSTI)

A mechanical covariant equation is introduced which retains all the effectingness of the Lagrange equation while being able to describe in a unified way other phenomena including friction, non-holonomic constraints and energy radiation (Lorentz-Abraham-Dirac force equation). A quantization rule adapted to the dissipative degrees of freedom is proposed which does not pass through the variational formulation.

E. Minguzzi

2014-10-01T23:59:59.000Z

244

International Symposium on Transport Phenomena 2-5 November, 2010, Kaohsiung City, Taiwan  

E-Print Network (OSTI)

are needed to harness or transport energy from various process industry operations. The available thermalThe 21st International Symposium on Transport Phenomena 2-5 November, 2010, Kaohsiung City, Taiwan Institute of Technology Kanpur, Kanpur (UP) 208016 India ABSTRACT We explore and scrutinize two possible

Khandekar, Sameer

245

Spin-dependent phenomena in digital-magnetic heterostructures: Clustering and phase-space filling effects  

E-Print Network (OSTI)

appreciated in the context of Mn-based heterostructures. In digital-magnetic heterostructures DMH's Mn-1829 98 51848-6 Spin-related phenomena are most conveniently studied in Mn-based semiconductors the correct or- der of magnitude of the energy splittings as a function of B as in bulk Mn-based systems and

Wilkins, John

246

Modeling of elasto-capillary phenomena David L. Henann*a  

E-Print Network (OSTI)

­22 It is important to make clear when the assumption of constant surface energy density, and hence the ideaModeling of elasto-capillary phenomena David L. Henann*a and Katia Bertoldi*bc Surface energy. However, when a solid is soft and its characteristic dimension is small, forces due to surface energy can

247

ELSEVIER Journal of ElectronSpectroscopyand Related Phenomena 73 (1995) 1-11 ELECTRON SPECTROSCOPY  

E-Print Network (OSTI)

1994;in finalform 9 August 1994 Abstract The adsorption of titanium on titanium dioxide TiO2(110) has SPECTROSCOPY andRelatedPhenomena Titanium and reduced titania overlayers on titanium dioxide(110) J.T. Mayer a spectroscopy I. Introduction Titanium dioxide has received extensive attention in the surface science community

Diebold, Ulrike

248

Sorption of Aldrich humic acids onto hematite: Insights into fractionation phenomena by  

E-Print Network (OSTI)

S1 Sorption of Aldrich humic acids onto hematite: Insights into fractionation phenomena by Electro, the absorbance spectra obtained for the initial PAHA sample and of supernatants from sorption experiments. Table S1: initial PAHA concentration and pH of the sorption experiments and absorbance values

Paris-Sud XI, Université de

249

Sorption of Aldrich Humic Acids onto Hematite: Insights into Fractionation Phenomena by Electrospray  

E-Print Network (OSTI)

Sorption of Aldrich Humic Acids onto Hematite: Insights into Fractionation Phenomena.reiller@cea.fr, +33 1 6908 4312 ;badia.amekraz@cea.fr, +33 1 6908 8034; Fax +33 1 6908 5411 Abstract. Sorption induced-mass range provided evidence of further fractionation induced by sorption within the LMWF. Among the two

Paris-Sud XI, Université de

250

Photocathode source for studying two-dimensional fluid phenomena with magnetized electron columns  

E-Print Network (OSTI)

Photocathode source for studying two-dimensional fluid phenomena with magnetized electron columns D have been generated with thermionic sources, typically limiting the initial electron distribution a new electron source based on a cesium antimonide photocathode that can generate more complicated

Fajans, Joel

251

Review of Preparedness for Severe Natural Phenomena Events at the Paducah Site, April 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

of of Preparedness for Severe Natural Phenomena Events at the Paducah Site May 2011 April 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose................................................................................................................................................ 1 2.0 Scope................................................................................................................................................... 1 3.0 Background ......................................................................................................................................... 2 4.0 Methodology ....................................................................................................................................... 3

252

Composition and biological degradability of lignin modified transgenic plants  

E-Print Network (OSTI)

Composition and biological degradability of lignin modified transgenic plants MA Bernard Vailhé, JM The influence of lignin quality on cell wall degradation was studied using, as model plants, control (C matter (DM) and lignin content were determined according to Jarrige (1961, Ann Biol Anim Biophys, 1, 163

Paris-Sud XI, Université de

253

Isolation, Identification, and Characterization of a Feather-Degrading Bacterium  

Science Journals Connector (OSTI)

...steam-sterilized or native wool keratin. Molyneaux con- ducted...S. 1959. The digestion of wool by a keratinolytic Bacillus...N. Tandan. 1950. A new wool degrading fungus-Ctenomyces...in thermophilic poultry waste digesters and enrichment of a feather-degrading...

C. M. Williams; C. S. Richter; J. M. MacKenzie Jr.; Jason C. H. Shih

1990-06-01T23:59:59.000Z

254

Characterization of Thermally Degraded Energetic Materials: Mechanical and Chemical Behavior  

SciTech Connect

We report the results of recent experiments on thermally degraded HMX and HMX/binder materials. Small-scale samples were heated confined in either constant-volume or load- controlled configurations. A main emphasis of the work reported here is developing an understanding of the complex coupling of the mechanical and chemical responses during thermal degradation.

Miller, J.C.; Renlund, A.M.; Schmitt, R.G.; Wellman, G.W.

1998-12-04T23:59:59.000Z

255

Mineralization of Pentachlorophenol With Enhanced Degradation and Power Generation From  

E-Print Network (OSTI)

­2221. � 2012 Wiley Periodicals, Inc. KEYWORDS: microbial fuel cell; PCP degradation rate; power production Cathode Microbial Fuel Cells Liping Huang,1 Linlin Gan,1 Ning Wang,1 Xie Quan,1 Bruce E. Logan,2 GuohuaARTICLE Mineralization of Pentachlorophenol With Enhanced Degradation and Power Generation From Air

256

Anaerobic, Sulfate-Dependent Degradation of Polycyclic Aromatic  

E-Print Network (OSTI)

-contaminated, marine harbor sediments in which sulfate reduction is the terminal electron- accepting process. However conditions, there was no significant decrease in the detectable pool of in situ naphthalene of the detectable pools of in situ 2-3 ring PAHs were degraded. In general, the smaller PAHs were degraded more

Lovley, Derek

257

Original article Sorption and degradation of tebutam in soil  

E-Print Network (OSTI)

Original article Sorption and degradation of tebutam in soil under controlled laboratory conditions-benzyl-N-isopropylpivalamide) sorption and degradation in the surface level (0­20 cm) of a brown silty clay soil. All the experiments. The sorption process was evaluated by adsorption kinetics, adsorption and desorption isotherms using a batch

Boyer, Edmond

258

Local Writhing Dynamics  

E-Print Network (OSTI)

We present an alternative local definition of the writhe of a self-avoiding closed loop which differs from the traditional non-local definition by an integer. When studying dynamics this difference is immaterial. We employ a formula due to Aldinger, Klapper and Tabor for the change in writhe and propose a set of local, link preserving dynamics in an attempt to unravel some puzzles about actin.

Randall D. Kamien

1997-03-13T23:59:59.000Z

259

DEFENSE HIGH LEVEL WASTE GLASS DEGRADATION  

SciTech Connect

The purpose of this Analysis/Model Report (AMR) is to document the analyses that were done to develop models for radionuclide release from high-level waste (HLW) glass dissolution that can be integrated into performance assessment (PA) calculations conducted to support site recommendation and license application for the Yucca Mountain site. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000a). It specifically addresses the item, ''Defense High Level Waste Glass Degradation'', of the product technical work plan. The AP-3.15Q Attachment 1 screening criteria determines the importance for its intended use of the HLW glass model derived herein to be in the category ''Other Factors for the Postclosure Safety Case-Waste Form Performance'', and thus indicates that this factor does not contribute significantly to the postclosure safety strategy. Because the release of radionuclides from the glass will depend on the prior dissolution of the glass, the dissolution rate of the glass imposes an upper bound on the radionuclide release rate. The approach taken to provide a bound for the radionuclide release is to develop models that can be used to calculate the dissolution rate of waste glass when contacted by water in the disposal site. The release rate of a particular radionuclide can then be calculated by multiplying the glass dissolution rate by the mass fraction of that radionuclide in the glass and by the surface area of glass contacted by water. The scope includes consideration of the three modes by which water may contact waste glass in the disposal system: contact by humid air, dripping water, and immersion. The models for glass dissolution under these contact modes are all based on the rate expression for aqueous dissolution of borosilicate glasses. The mechanism and rate expression for aqueous dissolution are adequately understood; the analyses in this AMR were conducted to provide models and parameter values that can be used to calculate the dissolution rates for the different modes of water contact. The analyses were conducted to identify key aspects of the mechanistic model for glass dissolution to be included in the abstracted models used for PA calculations, evaluate how the models can be used to calculate bounding values of the glass dissolution rates under anticipated water contact modes in the disposal. system, and determine model parameter values for the range of potential waste glass compositions and anticipated environmental conditions. The analysis of a bounding rate also considered the effects of the buildup of glass corrosion products in the solution contacting the glass and potential effects of alteration phase formation. Note that application of the models and model parameter values is constrained to the anticipated range of HLW glass compositions and environmental conditions. The effects of processes inherent to exposure to humid air and dripping water were not modeled explicitly. Instead, the impacts of these processes on the degradation rate were taken into account by using empirically measured parameter values. These include the rates at which water sorbs onto the glass, drips onto the glass, and drips off of the glass. The dissolution rates of glasses that were exposed to humid air and dripping water measured in laboratory tests are used to estimate model parameter values for contact by humid air and dripping water in the disposal system.

W. Ebert

2001-09-20T23:59:59.000Z

260

EPS HEP2005, Lisboa, 21.-27.07.2005General Search for New Phenomena at HERA and a Search for Magnetic Monopoles, Ana Dubak 1 General Search for New Phenomena  

E-Print Network (OSTI)

EPS HEP2005, Lisboa, 21.-27.07.2005General Search for New Phenomena at HERA and a Search for new phenomena at HERA · Direct Search for Magnetic Monopoles #12;EPS HEP2005, Lisboa, 21, have we missed something? General search ± e p 27.6 GeV (till 1998 EP = 820 GeV ) s = 320 GeV HERA

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Thermal degradation of cellulose in alkali  

SciTech Connect

Biomass in an alkaline aqueous slurry can be liquefied by heat and pressure. Understanding the mechanisms of biomass liquefaction to improve the efficiency of converting biomass to useful products, particularly chemicals and synthetic fuels is discussed. To study the chemical mechanisms of this process, pure cellulose, the main component of biomass, was liquefied. The 78 cellulose liquefaction products that were identified by gas chromatography/mass spectrometry include polyols, furans, ketones, hydrocarbons, and aromatic compounds. Polyols may be formed by hydrogenolytic cleavage. Furans an cyclic ketones may be cyclization products of dicarbonyl intermediates formed by aldol condensation of small initial degradation products such as acetone and acrolein. Several of these small carbonyl compounds were used as model compounds to test proposed mechanisms for furans and cyclic ketones and obtained products supporting five of the mechanisms. For the best case of 26 cellulose liquefaction experiments, 34% of the initial mass of the cellulose was converted to acetone-soluble oil with a heat of combustion of 14,000 Btu/lb.

Miller, R.K.; Molton, P.M.; Russell, J.A.

1980-12-01T23:59:59.000Z

262

SURVEY OF MODELS FOR CONCRETE DEGRADATION  

SciTech Connect

Concrete has been used in the construction of nuclear facilities because of two primary properties: its structural strength and its ability to shield radiation. Concrete structures have been known to last for hundreds of years, but they are also known to deteriorate in very short periods of time under adverse conditions. The use of concrete in nuclear facilities for containment and shielding of radiation and radioactive materials has made its performance crucial for the safe operation of the facility. The goal of this report is to review and document the main aging mechanisms of concern for concrete structures in nuclear power plants (NPPs) and the models used in simulations of concrete aging and structural response of degraded concrete structures. This is in preparation for future work to develop and apply models for aging processes and response of aged NPP concrete structures in the Grizzly code. To that end, this report also provides recommendations for developing more robust predictive models for aging effects of performance of concrete.

Spencer, Benjamin W [Idaho National Laboratory; Huang, Hai [Idaho Nation Laboratory

2014-08-01T23:59:59.000Z

263

Guide for the Mitigation of Natural Phenomena Hazards for DOE Nuclear Facilities and NonNuclear Facilities  

Directives, Delegations, and Requirements

This document provides guidance in implementing the Natural Phenomena Hazard (NPH) mitigation requirements of DOE O 420.1, Facility Safety, Section 4.4, "Natural Phenomena Hazards Mitigation." This Guide does not establish or invoke any new requirements. Any apparent conflicts arising from the NPH guidance would defer to the requirements in DOE O 420.1. No cancellation.

2000-03-28T23:59:59.000Z

264

Degradation measurement and analysis for cells and stacks  

SciTech Connect

Past research in solid oxide fuel cell (SOFC) performance assessment and improvement has focused on cell operating voltage (efficiency). Related to this metric, but distinct and equally important, is performance degradation. This paper examines cell degradation, provides key definitions needed for its characterization, and discusses the relationship of various cell performance variables. To characterize degradation, two parameters are defined, namely, area-specific resistance (ASR), and degradation rate (DR). The ASR of a cell/stack increases as a result of degradation, and therefore needs to be modeled as a time-dependent parameter. A model for SOFC cell performance is used to describe polarization losses, and to predict degradation performance. The model is then used to demonstrate the use of ASR and DR in the assessment of degradation. Available experimental data is separately used to do the same. ASR is shown to be insensitive to certain variations in test conditions and therefore is the preferred parameter for fuel cell developers when comparing performance differences arising from incremental changes in design/materials. DR is the preferred parameter for determining changes in efficiency over the lifetime of the cell/stack, which is a key concern for end users.

Randall S. Gemmen; Mark C.Williams; Kirk Gerdes

2008-06-01T23:59:59.000Z

265

Non-phosphate degradation products of tributyl phosphate  

SciTech Connect

Tributyl phosphate(TBP) was compulsively degraded with nitric acid and/or uranium nitrate at elevated temperature around 105{degrees}C. Experimental results indicates major non-phosphate degradation products are butyl nitrate (C{sub 4}H{sub 9}NO{sub 3}), propionic acid (C{sub 2}H{sub 5}COOH), acetic acid (CH{sub 3}COOH), butyric acid (C{sub 3}H{sub 7}COOH) and butyl alcohol (C{sub 4}H{sub 9}OH) in ascending order of quantity. Degrading rate in uranium free system is less than that in uranium coexisting system. Carboxylic acids were not produced in uranium free system, and only acetic acid was identified in case of without supplying nitric acid from aqueous phase. Moreover, from the experimental study on the reactivity of each non-phosphate product with nitric acid, carboxylic acids were identified as byproducts of butyl alcohol and butyl nitrate, and each carboxylic acid was stable in these degrading conditions. Finally, butyl alcohol is considered as one of intermediate products to butyl nitrate and carboxylic acids. From this study, the non-phosphate degradation products of TBP is identified and the degrading reaction pass is proposed. Extraction behavior of each non-phosphate product and reactivity of degraded TBP are also elucidated.

Tashiro, Y.; Kodama, R.; Sugai, H. [Japan Nuclear Fuel Ltd., Aomori (Japan)] [and others

1995-12-01T23:59:59.000Z

266

SENSITIVITY ANALYSIS FOR SALTSTONE DISPOSAL UNIT COLUMN DEGRADATION ANALYSES  

SciTech Connect

PORFLOW related analyses supporting a Sensitivity Analysis for Saltstone Disposal Unit (SDU) column degradation were performed. Previous analyses, Flach and Taylor 2014, used a model in which the SDU columns degraded in a piecewise manner from the top and bottom simultaneously. The current analyses employs a model in which all pieces of the column degrade at the same time. Information was extracted from the analyses which may be useful in determining the distribution of Tc-99 in the various SDUs throughout time and in determining flow balances for the SDUs.

Flach, G.

2014-10-28T23:59:59.000Z

267

Degradation of polychlorinated biphenyls (PCBs) using palladized iron  

SciTech Connect

Contamination from polychlorinated biphenyls (PCBs) is a persistent problem within the Department of Energy complex, as well as in numerous industrial sites around the US. To date, commercially available technologies for destroying these highly stable compounds involve degradation at elevated temperatures either through incineration or base-catalyzed dehalogenation at 300{degrees}C. Since the heating required with these processes substantially increases the costs for treatment of PCB-contaminated wastes, there is a need for finding an alternative approach where PCB can be degraded at ambient temperatures. This report describes the degradation of PCB`s utilizing the bimetallic substrate of iron/palladium.

West, O.R.; Liang, L.; Holden, W.L. [and others

1996-06-01T23:59:59.000Z

268

Comparative study of two- and three-dimensional modeling on arc discharge phenomena inside a thermal plasma torch with hollow electrodes  

SciTech Connect

A comparative study between two- and three-dimensional (2D and 3D) modeling is carried out on arc discharge phenomena inside a thermal plasma torch with hollow electrodes, in order to evaluate the effects of arc root configuration characterized by either 2D annular or 3D highly localized attachment on the electrode surface. For this purpose, a more precise 3D transient model has been developed by taking account of 3D arc current distribution and arc root rotation. The 3D simulation results apparently reveal that the 3D arc root attachment brings about the inherent 3D and turbulence nature of plasma fields inside the torch. It is also found that the constricted arc column near the vortex chamber plays an important role in heating and acceleration of injected arc gases by concentrating arc currents on the axis of the hollow electrodes. The inherent 3D nature of arc discharge is well preserved inside the cathode region, while these 3D features slowly diminish behind the vortex chamber where the turbulent flow begins to be developed in the anode region. Based on the present simulation results, it is noted that the mixing effects of the strong turbulent flow on the heat and mass transfer are mainly responsible for the gradual relaxation of the 3D structures of plasma fields into the 2D axisymmetric ones that eventually appear in the anode region near the torch exit. From a detailed comparison of the 3D results with the 2D ones, the arc root configuration seems to have a significant effect on the heat transfer to the electrode surfaces interacting with the turbulent plasma flow. That is, in the 2D simulation based on an axisymmetric stationary model, the turbulence phenomena are fairly underestimated and the amount of heat transferred to the cold anode wall is calculated to be smaller than that obtained in the 3D simulation. For the validation of the numerical simulations, calculated plasma temperatures and axial velocities are compared with experimentally measured ones, and the 3D simulation turns out to be more accurate than the 2D simulation as a result of a relatively precise description of the turbulent phenomena inside the torch using a more realistic model of arc root attachment. Finally, it is suggested that the 3D transient formulation is indeed required for describing the real arc discharge phenomena inside the torch, while the 2D stationary approach is sometimes useful for getting practical information about the time-averaged plasma characteristics outside the torch because of its simplicity and rapidness in computation.

Kim, Keun Su; Park, Jin Myung; Choi, Sooseok; Kim, Jongin; Hong, Sang Hee [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2008-02-15T23:59:59.000Z

269

Prediction and Uncertainty in Computational Modeling of Complex Phenomena: A Whitepaper  

SciTech Connect

This report summarizes some challenges associated with the use of computational science to predict the behavior of complex phenomena. As such, the document is a compendium of ideas that have been generated by various staff at Sandia. The report emphasizes key components of the use of computational to predict complex phenomena, including computational complexity and correctness of implementations, the nature of the comparison with data, the importance of uncertainty quantification in comprehending what the prediction is telling us, and the role of risk in making and using computational predictions. Both broad and more narrowly focused technical recommendations for research are given. Several computational problems are summarized that help to illustrate the issues we have emphasized. The tone of the report is informal, with virtually no mathematics. However, we have attempted to provide a useful bibliography that would assist the interested reader in pursuing the content of this report in greater depth.

Trucano, T.G.

1999-01-20T23:59:59.000Z

270

Acoustic Emission Signal Processing Technique to Characterize Reactor In-Pile Phenomena  

SciTech Connect

Existing and developing advanced sensor technologies and instrumentation will allow non-intrusive in-pile measurement of temperature, extension, and fission gases when coupled with advanced signal processing algorithms. The transmitted measured sensor signals from inside to the outside of containment structure are corrupted by noise and are attenuated, thereby reducing the signal strength and signal-to-noise ratio. Identification and extraction of actual signal (representative of an in-pile phenomenon) is a challenging and complicated process. In this paper, empirical mode decomposition technique is proposed to reconstruct actual sensor signal by partially combining intrinsic mode functions. Reconstructed signal corresponds to phenomena and/or failure modes occurring inside the reactor. In addition, it allows accurate non-intrusive monitoring and trending of in-pile phenomena.

Vivek Agarwal; Magdy Samy Tawfik; James A Smith

2014-07-01T23:59:59.000Z

271

Review of Preparedness for Severe Natural Phenomena Events at the Lawrence Livermore National Laboratory, July 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

Independent Oversight Review of Independent Oversight Review of Preparedness for Severe Natural Phenomena Events at the Lawrence Livermore National Laboratory May 2011 July 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose................................................................................................................................................ 1 2.0 Scope................................................................................................................................................... 1 3.0 Background ......................................................................................................................................... 2

272

Alternative large-N limit for QCD and its implications for low-energy nuclear phenomena  

Science Journals Connector (OSTI)

The Corrigan-Ramond model for large-N QCD is analyzed in detail. The spectrum, leading-order results for interactions, and an effective Lagrangian describing large-N interactions are derived. This Lagrangian, when quantized, provides an effective quantum field theory for mesons and baryons. The applicability of such a theory to low-energy nuclear phenomena is studied. The model has features that distinguish it clearly from standard large-N QCD.

Elias B. Kiritsis and Joannis Papavassiliou

1990-12-15T23:59:59.000Z

273

Experiments to investigate direct containment heating phenomena with scaled models of the Surry Nuclear Power Plant  

SciTech Connect

The Containment Technology Test Facility (CTTF) and the Surtsey Test Facility at Sandia National Laboratories are used to perform scaled experiments that simulate High Pressure Melt Ejection accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive melt (thermite) is ejected by high-pressure steam into a scale model of a reactor cavity. Debris is entrained by the steam blowdown into a containment model where specific phenomena, such as the effect of subcompartment structures, prototypic air/steam/hydrogen atmospheres, and hydrogen generation and combustion, can be studied. Four Integral Effects Tests (IETs) have been performed with scale models of the Surry NPP to investigate DCH phenomena. The 1/61{sup th} scale Integral Effects Tests (IET-9, IET-10, and IET-11) were conducted in CTRF, which is a 1/6{sup th} scale model of the Surry reactor containment building (RCB). The 1/10{sup th} scale IET test (IET-12) was performed in the Surtsey vessel, which had been configured as a 1/10{sup th} scale Surry RCB. Scale models were constructed in each of the facilities of the Surry structures, including the reactor pressure vessel, reactor support skirt, control rod drive missile shield, biological shield wall, cavity, instrument tunnel, residual heat removal platform and heat exchangers, seal table room and seal table, operating deck, and crane wall. This report describes these experiments and gives the results.

Blanchat, T.K.; Allen, M.D.; Pilch, M.M. [Sandia National Labs., Albuquerque, NM (United States); Nichols, R.T. [Ktech Corp., Albuquerque, NM (United States)

1994-06-01T23:59:59.000Z

274

E-Print Network 3.0 - anaerobic protein-degrading hyperthermophilic...  

NLE Websites -- All DOE Office Websites (Extended Search)

protein-degrading hyperthermophilic Search Powered by Explorit Topic List Advanced Search Sample search results for: anaerobic protein-degrading hyperthermophilic Page: << < 1 2 3...

275

E-Print Network 3.0 - aromatic hydrocarbon pah-degrading Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

degradation Summary: Removal of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge by anaerobic degradation N... , terminate in the sludge, and can be released to the...

276

E-Print Network 3.0 - assess soil degradation Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

of pesticide degradation on sorption: nonequilibrium model and application to soil reactors Lei Guo a , William... on degradation of the pesticide 2,4-dichlorophenoxyacetic acid...

277

Local Clean Area  

Science Journals Connector (OSTI)

There are three main development circumstances for the air cleaning methods: application in cleanroom alone, application as the local air cleaning ... cleaning bench) alone, and application both in cleanroom and ...

Zhonglin Xu

2014-01-01T23:59:59.000Z

278

On Local LYM Identities  

Science Journals Connector (OSTI)

The LYMinequality (Lubell, Yamamoto, Meshalkin) is a generalization of...normalized matching property (or local LYM inequality) are equivalent. Many contributions have been proposed to sharpen the LYM inequality....

Tran Dan Thu

2013-11-01T23:59:59.000Z

279

State and Local Incentives  

Energy.gov (U.S. Department of Energy (DOE))

To help you make energy efficiency improvements in your commercial building, your state and/or local community might offer incentives or have special programs. See the following resources for more...

280

Materials Degradation in Light Water Reactors: Life After 60 | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Materials Degradation in Light Water Reactors: Life After 60 Materials Degradation in Light Water Reactors: Life After 60 Materials Degradation in Light Water Reactors: Life After 60 Nuclear reactors present a very harsh environment for components service. Components within a reactor core must tolerate high temperature water, stress, vibration, and an intense neutron field. Degradation of materials in this environment can lead to reduced performance, and in some cases, sudden failure. A recent EPRI-led study interviewed 47 US nuclear utility executives to gauge perspectives on long-term operation of nuclear reactors. Nearly 90% indicated that extensions of reactor lifetimes to beyond 60 years were likely. When polled on the most challenging issues facing further life extension, two-thirds cited plant reliability as the

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Light Water Reactor Sustainability Program: Materials Aging and Degradation  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Materials Aging and Materials Aging and Degradation Technical Program Plan Light Water Reactor Sustainability Program: Materials Aging and Degradation Technical Program Plan Components serving in a nuclear reactor plant must withstand a very harsh environment including extended time at temperature, neutron irradiation, stress, and/or corrosive media. The many modes of degradation are complex and vary depending on location and material. However, understanding and managing materials degradation is a key for the continued safe and reliable operation of nuclear power plants. Extending reactor service to beyond 60 years will increase the demands on materials and components. Therefore, an early evaluation of the possible effects of extended lifetime is critical. The recent NUREG/CR-6923 gives a

282

Materials Degradation in Light Water Reactors: Life After 60 | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Materials Degradation in Light Water Reactors: Life After 60 Materials Degradation in Light Water Reactors: Life After 60 Materials Degradation in Light Water Reactors: Life After 60 Nuclear reactors present a very harsh environment for components service. Components within a reactor core must tolerate high temperature water, stress, vibration, and an intense neutron field. Degradation of materials in this environment can lead to reduced performance, and in some cases, sudden failure. A recent EPRI-led study interviewed 47 US nuclear utility executives to gauge perspectives on long-term operation of nuclear reactors. Nearly 90% indicated that extensions of reactor lifetimes to beyond 60 years were likely. When polled on the most challenging issues facing further life extension, two-thirds cited plant reliability as the

283

Kinetic study of degradation of heavy oil over MCM-41  

Science Journals Connector (OSTI)

Thermogravimetry was applied in order to investigate the catalytic degradation of heavy oil (15.4oAPI) over silica-based MCM-41 mesoporous molecular sieve. This material was synthesised by the hydrothermal method...

Edjane F. B. Silva; Marcílio P. Ribeiro…

2011-12-01T23:59:59.000Z

284

Mixed Hydrologic Recovery of a Degraded Mesquite Rangeland  

E-Print Network (OSTI)

Land degradation and anthropogenic change is widespread on rangelands in Texas. Over the last 150 years, noticeable change has occurred as a direct result of agricultural practices and human activity. As novel ecosystems and permanently altered...

Lukenbach, Maxwell

2011-08-08T23:59:59.000Z

285

Microbial petroleum degradation enhancement by oil spill bioremediation products  

E-Print Network (OSTI)

was conducted using unpolluted, natural seawater. The products were tested in triplicate using 250 ml Erlenmeyer flasks and evaluated over a 28 day period to determine the products' capabilities based on the extent of petroleum degradation. Toxicity...

Lee, Salvador Aldrett

1996-01-01T23:59:59.000Z

286

Enzymatic degradation of guar galactomannans: A rheological study  

SciTech Connect

Aqueous gels of guar gum and its derivatives are widely used in hydraulic fracturing for enhancing oil or gas production. Subsequently, these gels need to be degraded and flushed out of the wells to provide passage for oil or gas flow. The use of thermostable enzymes to hydrolyze the guar gums offers a novel and viable approach to polymer degradation for this application. Most wells of commercial interest are at high temperatures and the use of enzymatic degradation can lead to a significant expansion in the use of hydraulic fracturing for oil and gas recovery. In this study, steady shear measurements are used to determine the effect of several enzymes on polymer viscosity. The effect of various parameters such as enzyme type and concentration, temperature of hydrolysis and pH of the solutions on the extent and kinetics of polymer degradation are discussed.

Tayal, Akash; Khan, S.A. [North Carolina State Univ., Raleigh, NC (United States)

1995-12-01T23:59:59.000Z

287

Extended abstract Fibre degrading enzymes, their origin and diversity  

E-Print Network (OSTI)

of this species is considered to be xylan degradation. Other secondary cellulolytic species (found sporadically- tienzyme complexes at the surface or in the extracellular culture medium of the main cellulolytic bacterial

Boyer, Edmond

288

Modeling of Catalyst Structure Degradation in PEM Fuel Cells  

Science Journals Connector (OSTI)

In this chapter, the requirements of a high-performance catalyst layer are examined in order to understand the ways in which the structure might degrade with operation. The formation of oxide species on the su...

Jeremy P. Meyers

2009-01-01T23:59:59.000Z

289

AN INVESTIGATION OF THE DEGRADATION OF PROPYLENE CARBONATE BY CHLORINE  

E-Print Network (OSTI)

water and then thoroughly dried before use. chamber.. During electrolysis,electrolysis using This leads us to suspect that the extent of degradation is a strong function of the amount of water

Yu, Suen-Man G.

2012-01-01T23:59:59.000Z

290

Small-Molecule Control of Protein Degradation Using Split Adaptors  

E-Print Network (OSTI)

Targeted intracellular degradation provides a method to study the biological function of proteins and has numerous applications in biotechnology. One promising approach uses adaptor proteins to target substrates with ...

Davis, Joseph H.

291

Computational Modeling of Degradation of Substituted Benzyltrimethyl Ammonium: Preprint  

SciTech Connect

The degradation of cations on the alkaline exchange membranes is the major challenge for alkaline membrane fuel cells. In this paper, we investigated the degradation barriers by density functional theory for substituted benzyltrimethyl ammonium (BTMA+) cations, which is one of the most commonly used cations for alkaline exchange membranes. We found that substituted cations with electron-releasing substituent groups at meta-position of the benzyl ring could result in improved degradation barriers. However, after investigating more than thirty substituted BTMA+ cations with ten different substituent groups, the largest improvement of degradation barriers is only 1.6 kcal/mol. This implies that the lifetime of alkaline membrane fuel cells could increase from a few months to a few years by using substituted BTMA+ cations, an encouraging but still limited improvement for real-world applications.

Long, H.; Pivovar, B. S.

2014-09-01T23:59:59.000Z

292

Thermal and Oxidative Degradation of Castor Oil Biodiesel  

Science Journals Connector (OSTI)

Thermal and Oxidative Degradation of Castor Oil Biodiesel ... The neat biodiesels, 20% blends, and the base fuel (No. 2 diesel) were tested at 2 different loads (100 and 20%) and 3 injection timings (3° advanced, std., 3° retarded). ...

Marta M. Conceição; Valter J. Fernandes, Jr.; Antonio S. Araújo; Mirna F. Farias; Ieda M. G. Santos; Antonio G. Souza

2007-03-23T23:59:59.000Z

293

Aliphatic Polyester Block Polymers: Renewable, Degradable, and Sustainable  

Science Journals Connector (OSTI)

Aliphatic Polyester Block Polymers: Renewable, Degradable, and Sustainable ... Yet, such polymers are “challenged” with respect to sustainability. ... The Earth harbors finite carbon-based feedstocks that are being rapidly depleted by our increasing energy demand. ...

Marc A. Hillmyer; William B. Tolman

2014-05-22T23:59:59.000Z

294

Degradation Pathway Models for Photovoltaics Module Lifetime Performance  

E-Print Network (OSTI)

Degradation Pathway Models for Photovoltaics Module Lifetime Performance Nicholas R. Wheeler, Laura data from Underwriter Labs, featuring measurements taken on 18 identical photovoltaic (PV) modules in modules and their effects on module performance over lifetime. Index Terms--photovoltaics, statistical

Rollins, Andrew M.

295

Thermal degradation chemistry of poly[bis(phenoxy)phosphazene  

E-Print Network (OSTI)

THERMAL DEGRADATION CHEMISTRY OF POLY[BIS(PHENOXY)PHOSPHAZENE] A Thesis by SHAWN JOSEPH MAYNARD Submitted to the Office of Graduate Studies of Texas A&M University in Partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1989 Major subject: Chemistry THERMAL DEGRADATION CHEMISTRY OF POLY[BIS(PHENOXY)PHOSPHAZENE] A Thesis by SHAWN JOSEPH MAYNARD Approved as to style and content by: J. F. Haw (Chair of Committee) Mic ael B. Hal (Head...

Maynard, Shawn Joseph

1989-01-01T23:59:59.000Z

296

Petroleum hydrocarbon-degrading bacteria in the Galveston Bay system  

E-Print Network (OSTI)

PETROLEUM HYDRQCARBOiV-DEGRADING BACTERIA IN THE GALVESTON BAY SYSTEM A Thesis by STEVEN JAMES SCHROPP Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIFNCE... December 1979 Major Subject: Biology PETROLEUM HYDROCARBON-DEGRADING BACTERIA IN THE GALVESTON BAY SYSTEM A Thesis by STEVEN JAMES SCHROPP Approved as to style and content by: (Co-Chairman of Committee) '( ~CA. ( -Chairman of Committee) (Head...

Schropp, Steven James

1979-01-01T23:59:59.000Z

297

Inhibition of protein degradation by peptide protease inhibitors  

E-Print Network (OSTI)

INHIBITION OF PROTEIN DEGRADATION BY PEPTIDE PROTEASE INHIBITORS A Thesis by REBECCA ANNE OWENS Submitted to the Graduate College of Texas ALN Universi. ty in partial fulfillment of the requirement for the degree of NASTER OF SCIENCE August... 1980 Major Subj ect: Biochemistry INHIBITION OF PROTEIN DEGRADATION BY PEPTIDE PROTEASE INHIBITORS A Thesis by REBECCA ANNE OWENS Approved as to style and content by: ~ C&irman qf M~ttee) I ), (Member) (Member) (Head of Department) August...

Owens, Rebecca Anne

1980-01-01T23:59:59.000Z

298

Aging Management using Proactive Management of Materials Degradation  

SciTech Connect

The U.S. Nuclear Regulatory Commission (NRC) has undertaken a program to lay the technical foundations for defining proactive actions to manage degradation of materials in light water reactors (LWRs). The current focus is existing plants; however, if applied to new construction, there is potential to better monitor and manage plants throughout their life cycle. This paper discusses the NRC’s Proactive Management of Materials Degradation (PMMD) program and its application to nuclear power plant structures, systems, and components (SSC).

Doctor, Steven R.; Bond, Leonard J.; Cumblidge, Stephen E.; Bruemmer, Stephen M.; Taylor, W Boyd; Carpenter, C. E. (Gene); Hull, Amy B.; Malik, Shah

2010-10-01T23:59:59.000Z

299

Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 5: Graphite PIRTs  

SciTech Connect

Here we report the outcome of the application of the Nuclear Regulatory Commission (NRC) Phenomena Identification and Ranking Table (PIRT) process to the issue of nuclear-grade graphite for the moderator and structural components of a next generation nuclear plant (NGNP), considering both routine (normal operation) and postulated accident conditions for the NGNP. The NGNP is assumed to be a modular high-temperature gas-cooled reactor (HTGR), either a gas-turbine modular helium reactor (GTMHR) version [a prismatic-core modular reactor (PMR)] or a pebble-bed modular reactor (PBMR) version [a pebble bed reactor (PBR)] design, with either a direct- or indirect-cycle gas turbine (Brayton cycle) system for electric power production, and an indirect-cycle component for hydrogen production. NGNP design options with a high-pressure steam generator (Rankine cycle) in the primary loop are not considered in this PIRT. This graphite PIRT was conducted in parallel with four other NRC PIRT activities, taking advantage of the relationships and overlaps in subject matter. The graphite PIRT panel identified numerous phenomena, five of which were ranked high importance-low knowledge. A further nine were ranked with high importance and medium knowledge rank. Two phenomena were ranked with medium importance and low knowledge, and a further 14 were ranked medium importance and medium knowledge rank. The last 12 phenomena were ranked with low importance and high knowledge rank (or similar combinations suggesting they have low priority). The ranking/scoring rationale for the reported graphite phenomena is discussed. Much has been learned about the behavior of graphite in reactor environments in the 60-plus years since the first graphite rectors went into service. The extensive list of references in the Bibliography is plainly testament to this fact. Our current knowledge base is well developed. Although data are lacking for the specific grades being considered for Generation IV (Gen IV) concepts, such as the NGNP, it is fully expected that the behavior of these graphites will conform to the recognized trends for near isotropic nuclear graphite. Thus, much of the data needed is confirmatory in nature. Theories that can explain graphite behavior have been postulated and, in many cases, shown to represent experimental data well. However, these theories need to be tested against data for the new graphites and extended to higher neutron doses and temperatures pertinent to the new Gen IV reactor concepts. It is anticipated that current and planned future graphite irradiation experiments will provide the data needed to validate many of the currently accepted models, as well as providing the needed data for design confirmation.

Burchell, Timothy D [ORNL; Bratton, Rob [Idaho National Laboratory (INL); Marsden, Barry [University of Manchester, UK; Srinivasan, Makuteswara [U.S. Nuclear Regulatory Commission; Penfield, Scott [Technology Insights; Mitchell, Mark [PBMR (Pty) Ltd.; Windes, Will [Idaho National Laboratory (INL)

2008-03-01T23:59:59.000Z

300

Elastic Relaxation and Correlation of Local Strain Gradients with  

NLE Websites -- All DOE Office Websites (Extended Search)

Elastic Relaxation and Correlation Elastic Relaxation and Correlation of Local Strain Gradients with Ferroelectric Domains in (001) BiFeO3 Nanostructures Elastic Relaxation and Correlation of Local Strain Gradients with Ferroelectric Domains in (001) BiFeO3 Nanostructures Researchers at Argonne National Laboratory (MSD and CNM) have recently performed first worldwide studies of effects of nanopatterning on fundamental phenomena in mutiferroic BiFeO3 (BFO) nanostructures, using the APS-CNM nanoprobe beam (50 nm diameter). Nano-focused x-ray diffraction microscopy provided new insights into the relationship between film strain and ferroelectric domains in nanostructures, namely: i) an out-of-plane strain enhancement of as much as -1.8% Δc/c in a BFO film-based nanostructure relative to a planar film; ii) out-of-plane BFO C-axis

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Sampling based on local bandwidth  

E-Print Network (OSTI)

The sampling of continuous-time signals based on local bandwidth is considered in this thesis. In an intuitive sense, local bandwidth refers to the rate at which a signal varies locally. One would expect that signals should ...

Wei, Dennis

2007-01-01T23:59:59.000Z

302

Model electrode structures for studies of electrocatalyst degradation.  

SciTech Connect

Proton exchange membrane fuel cells are being extensively studied as power sources because of their technological advantages such as high energy efficiency and environmental friendliness. The most effective catalyst in these systems consists of nanoparticles of Pt or Pt-based alloys on carbon supports. Understanding the role of the nanoparticle size and structure on the catalytic activity and degradation is needed to optimize the fuel cell performance and reduce the noble metal loading. One of the more significant causes of fuel cell performance degradation is the cathode catalyst deactivation. There are four mechanisms considered relevant to the loss of electrochemically active surface area of Pt in the fuel cell electrodes that contribute to cathode catalyst degradation including: catalyst particle sintering such as Ostwald ripening, migration and coalescence, carbon corrosion and catalyst dissolution. Most approaches to study this catalyst degradation utilize membrane electrode assemblies (MEAs), which results in a complex system where it is difficult to deconvolute the effects of the metal nanoparticles. Our research addresses catalyst degradation by taking a fundamental approach to study electrocatalyst using model supports. Nanostructured particle arrays are engineered directly onto planar glassy carbon electrodes. These model electrocatalyst structures are applied to electrochemical activity measurements using a rotating disk electrode and surface characterization by scanning electron microscopy. Sample transfer between these measurement techniques enables examination of the same catalyst area before and after electrochemical cycling. This is useful to probe relationships between electrochemical activity and catalyst structure such as particle size and spacing. These model systems are applied to accelerated aging studies of activity degradation. We will present our work demonstrating the mechanistic aspects of catalyst degradation using this simplified geometric system. The active surface area loss observed in repeated cyclic voltammetry is explained through characterization and imaging of the same RDE electrode structures throughout the aging process.

St. Pierre, Jean (University of South Carolina); Atanassov, Plamen Borissov (University of New Mexico); Datye, Abhaya K. (University of New Mexico); Goeke, Ronald S. (University of New Mexico)

2010-10-01T23:59:59.000Z

303

Phase-change-related degradation of catalyst layers in  

NLE Websites -- All DOE Office Websites (Extended Search)

Phase-change-related degradation of catalyst layers in Phase-change-related degradation of catalyst layers in proton-exchange-membrane fuel cells Title Phase-change-related degradation of catalyst layers in proton-exchange-membrane fuel cells Publication Type Journal Article Year of Publication 2013 Authors Hwang, Gi Suk, Hyoungchul Kim, Roger Lujan, Rangachary Mukundan, Dusan Spernjak, Rodney L. Borup, Massoud Kaviany, Moo Hwan Kim, and Adam Z. Weber Journal Electrochimica Acta Volume 95 Pagination 29 - 37 Date Published 4/2013 ISSN 00134686 Keywords degradation, Environmental scanning electron microscope (ESEM), Freeze/thaw cycle, Membrane electrode assembly (MEA), Nanostructured thin film (NSTF), Pt/C dispersion Abstract Understanding and optimizing water and thermal management in the catalyst layer of proton-exchange-membrane fuel cells is crucial for performance and durability improvements. This is especially the case at low temperatures, where liquid water and even ice may exist. In this article, the durability of a traditional Pt/C dispersed and a nanostructure thin film (NSTF) membrane-electrode assembly (MEA) are examined under wet/dry and freeze/thaw cycles using both in situ and ex situ experiments. Multiple isothermal cold starts result in a performance degradation for the dispersed MEA, while no such a degradation is found in the NSTF. The results are consistent with stand-alone MEA tests, wherein the dispersed catalyst layer results in an exponential increase in the number and size of cracks until it delaminates from the membrane due to the impact of the freeze/thaw process within the catalyst-layer pores. The NSTF catalyst layer shows minimal crack generation without delamination since the ice forms on top of the layer. The results are useful for understanding degradation due to phase-change containing cycles.

304

Electrospray Mass Spectrometric Analysis and Photocatalytic Degradation of Polyethoxylate Surfactants Used in Wool Scouring  

Science Journals Connector (OSTI)

Electrospray Mass Spectrometric Analysis and Photocatalytic Degradation of Polyethoxylate Surfactants Used in Wool Scouring ...

Kim B. Sherrard; Philip J. Marriott; Malcolm J. McCormick; Ray Colton; Geoff Smith

1994-10-01T23:59:59.000Z

305

Review of Natural Phenomena Hazards (NPH) Requirements Currently Applied to the Thomas Jefferson National Accelerator Facility (TJNAF)  

Energy.gov (U.S. Department of Energy (DOE))

Review of Natural Phenomena Hazards (NPH) Requirements Currently Applied to the Thomas Jefferson National Accelerator Facility (TJNAF) By: Integrated NPH Team: David Luke, Lead, TJSO Rusty Sprouse, JSA Michael A. Epps, TJSO Richard Korynta, TJSO

306

DZero (D0) Experiment Results for New Phenomena from the Fermilab Tevatron  

DOE Data Explorer (OSTI)

The D0 (DZero) Experiment is a worldwide collaboration of scientists conducting research on the fundamental nature of matter. The experiment is located at the Tevatron Collider, Fermilab. The research is focused on precise studies of interactions of protons and antiprotons and involves an intense search for subatomic clues that reveal the character of the building blocks of the universe. This web page provides access to Run II research results of the New Phenomena Physics group, including preliminary, submitted, and published results. Figures and data plots are found in the same directories with their respective papers.

307

Collider Detector at Fermilab (CDF): Data from Supersymmetry, New Phenomena Research of the CDF Exotics Group  

DOE Data Explorer (OSTI)

The Collider Detector at Fermilab (CDF) is a Tevatron experiment at Fermilab. The Tevatron, a powerful particle accelerator, accelerates protons and antiprotons close to the speed of light, and then makes them collide head-on inside the CDF detector. The CDF detector is used to study the products of such collisions. The CDF Physics Group at Fermilab is organized into six working groups, each with a specific focus. The Exotics group searches for Supersymmetry and other New Phenomena. Their public web page makes data and numerous figures available from both CDF Runs I and II.

308

Possibility of coherent phenomena such as Bloch oscillations with single photons via W states  

SciTech Connect

We examine the behavior of single photons at multiport devices and inquire if coherent effects are possible. In particular we study how single photons need to be manipulated in order to study coherent phenomena. We show that single photons need to be produced in W states which lead to vanishing mean amplitude but nonzero correlations between the inputs at different ports. Such correlations restore coherent effects with single photons. As a specific example we demonstrate Bloch oscillations with single photons and thus provide strict analog of Bloch oscillation of electrons.

Rai, Amit; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2009-05-15T23:59:59.000Z

309

Ionomer Degradation in Electrodes of PEM Fuel Cell  

SciTech Connect

Although PEMFC Membrane Electrode Assembly (MEA) durability related studies have increased dramatically since 2004, studies on ionomer degradation of the composite electrodes has received far less attention than that of the proton exchange membranes, electrocatalysts, and catalyst supports. The catalyst layer ionomer unavoidably gets involved in other components degradation processes since it is subjected to exposure to different operating effects, including the presence of the catalyst, catalyst support, and the porous nature of the electrode layer which includes 2-phase flow. PEMFC durability issues cannot be fully resolved without understanding the contribution of ionomer degradation in electrode to the performance decay in life time. However, addressing the impact of changes to the catalyst layer ionomer during durability tests is experimentally difficult mainly because of the need to separate the ionomer in the electrode from other components during chemical, electrical and materials characterization. The catalyst layer ionomer is essentially chemically identical to the membrane ionomeric material, and is composed of low atomic number elements, making characterization difficult. In the present work, MEAs with different Nafion ionomer types: stabilized and non-stablized ionomer in the electrode layer (Type I) and mixed membrane/ionomer MEAs (Type II) were designed to separate ionomer degradation from membrane degradation, as shown in Figure (1a) and (b) respectively. Stabilized and non stabilized ionomers were 5% Nafion{reg_sign} solutions (Ion Power, New Castle, Delaware). The non-stabilized version is the typical Nafion chemical structure with carboxylic acid (-COOH) end groups; these end groups are thought to be a susceptible point of degradative peroxide attack. The stabilized version replaces the -COOH end groups with -CF{sub 3} end groups to prevent peroxide attack at the end groups. Type I MEAs were designed to compare ionomer degradation and its effect on performance decay. Since F{sup -} ions are released only from PFSA based membranes, and not from non-PFSA based membranes, Type II MEAs use a hydrocarbon membrane with no fluorine with a PFSA (Nafion{reg_sign}) ionomer in the catalyst layer for FER measurements. Any F{sup -} ions measured will then have come only for the catalyst layer ionomer during degradation experiments. Type II MEAs allow more detailed chemical characterization exclusively of the catalyst layer ionomer to better understand its degradation.

Borup, Rodney L. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

310

Recent progress in degradation and stabilization of organic solar cells  

SciTech Connect

Stability is of paramount importance in organic semiconductor devices, especially in organic solar cells (OSCs). Serious degradation in air limits wide applications of these flexible, light-weight and low-cost power-generation devices. Studying the stability of organic solar cells will help us understand degradation mechanisms and further improve the stability of these devices. There are many investigations into the efficiency and stability of OSCs. The efficiency and stability of devices even of the same photoactive materials are scattered in different papers. In particular, the extrinsic degradation that mainly occurs near the interface between the organic layer and the cathode is a major stability concern. In the past few years, researchers have developed many new cathodes and cathode buffer layers, some of which have astonishingly improved the stability of OSCs. In this review article, we discuss the recent developments of these materials and summarize recent progresses in the study of the degradation/stability of OSCs, with emphasis on the extrinsic degradation/stability that is related to the intrusion of oxygen and water. The review provides detailed insight into the current status of research on the stability of OSCs and seeks to facilitate the development of highly-efficient OSCs with enhanced stability.

Cao, Huanqi; He, Weidong; Mao, Yiwu; Lin, Xiao; Ishikawa, Ken; Dickerson, James H.; Hess, Wayne P.

2014-10-15T23:59:59.000Z

311

Enhanced regeneration of degraded polymer solar cells by thermal annealing  

SciTech Connect

The degradation and thermal regeneration of poly(3-hexylethiophene) (P3HT):[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) and P3HT:indene-C{sub 60} bisadduct (ICBA) polymer solar cells, with Ca/Al and Ca/Ag cathodes and indium tin oxide/poly(ethylene-dioxythiophene):polystyrene sulfonate anode have been investigated. Degradation occurs via a combination of three primary pathways: (1) cathodic oxidation, (2) active layer phase segregation, and (3) anodic diffusion. Fully degraded devices were subjected to thermal annealing under inert atmosphere. Degraded solar cells possessing Ca/Ag electrodes were observed to regenerate their performance, whereas solar cells having Ca/Al electrodes exhibited no significant regeneration of device characteristics after thermal annealing. Moreover, the solar cells with a P3HT:ICBA active layer exhibited enhanced regeneration compared to P3HT:PCBM active layer devices as a result of reduced changes to the active layer morphology. Devices combining a Ca/Ag cathode and P3HT:ICBA active layer demonstrated ?50% performance restoration over several degradation/regeneration cycles.

Kumar, Pankaj, E-mail: pankaj@mail.nplindia.ernet.in [CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Centre for Organic Electronics, Physics, University of Newcastle, Callaghan NSW-2308 (Australia); Bilen, Chhinder; Zhou, Xiaojing; Belcher, Warwick J.; Dastoor, Paul C., E-mail: Paul.Dastoor@newcastle.edu.au [Centre for Organic Electronics, Physics, University of Newcastle, Callaghan NSW-2308 (Australia); Feron, Krishna [Centre for Organic Electronics, Physics, University of Newcastle, Callaghan NSW-2308 (Australia); CSIRO Energy Technology, P. O. Box 330, Newcastle NSW 2300 (Australia)

2014-05-12T23:59:59.000Z

312

Local Safety Committee Engineering  

E-Print Network (OSTI)

Minutes Local Safety Committee Name of Committee Engineering Worksite Mailing Address & Postal Code J. Pannell ECE Support Engineer x Ken Jodrey E-Shops, for B. Wilson x * co-chairs Brad Hayes Safety, no report. Pending C. Safety Day Planning Committee Planning for Safety Days on Sept. 10 & 11 continues

Saskatchewan, University of

313

Local Safety Committee Engineering  

E-Print Network (OSTI)

Minutes Local Safety Committee Name of Committee Engineering Worksite Mailing Address & Postal Code-Shops Tech x R. Dahlgren Safety Resources x L. Wilson (support) Dean's Office x D. Hart Safety Resources x T involving chemicals. C. Safety Day Planning Committee L. Roth reported that the schedule of speakers

Saskatchewan, University of

314

Local microwave background radiation  

E-Print Network (OSTI)

An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

Domingos Soares

2014-11-13T23:59:59.000Z

315

Survey of degradation modes of four nickel-chromium-molybdenum alloys  

SciTech Connect

This report examines the degradation modes of four Ni-Cr-Mo alloys under conditions relevant to the Yucca Mountain Site Characterization Project (YMP). The materials considered are Alloys C-276, C-4, C-22, and 625 because they have desirable characteristics for the conceptual design (CD) of the high-level radioactive-waste containers presented in the YMP Site Characterization Plan (SCP). The types of degradation covered in this report are general corrosion; localized corrosion, including pitting and crevice corrosion; stress corrosion cracking in chloride environments; hydrogen embrittlement (HE); and undesirable phase transformations due to a lack of phase stability. Topics not specifically addressed are welding concerns and microbiological corrosion. The four Ni-Cr-Mo alloys have excellent corrosion resistance in chloride environments such as seawater as well as in more aggressive environments. They have significantly better corrosion resistance than the six materials considered for the CD waste container in the YMP SCP. (Those six materials are Types 304L and 3161L stainless steels, Alloy 825, unalloyed copper, Cu(70)-Ni(30), and 7% aluminum bronze.) In seawater, the Ni-Cr-Mo alloys have negligible general corrosion rates and show little evidence of localized corrosion. The four base materials of these alloys are expected to have nearly indistinguishable corrosion resistance in the YMP environments. The strength requirements of the SCP-CD waste container are met by these materials in the annealed condition; in this condition, they are highly resistant to HE. Historically, HE has been noted when these materials have been strengthened (cold-worked) and used in sour gas (H{sub 2}S and CO{sub 2}) well service -- conditions that are not expected for the YMP. Metallurgical phase stability may be a concern under conditions favoring (1) the formation of intermetallics and carbides, and (2) microstructural ordering.

Gdowski, G.E. [KMI Energy Services, Livermore, CA (United States)] KMI Energy Services, Livermore, CA (United States)

1991-03-01T23:59:59.000Z

316

Why Sequence a Benzene-Degrading Methanogenic Consortium?  

NLE Websites -- All DOE Office Websites (Extended Search)

a Benzene-Degrading Methanogenic Consortium? a Benzene-Degrading Methanogenic Consortium? As recently as the 1990's, aromatic hydrocarbons like benzene and toluene were thought to be resistant to degradation under anaerobic conditions. It is now appreciated that biodegradation in the absence of oxygen contributes significantly to the attenuation of hydrocarbons and other pollutants in the environment. Unravelling the yet unknown pathways and mechanisms of anaerobic benzene metabolism is a critical milestone for hydrocarbon bioremediation. While many pathways have been suggested, none has been proven, and no genes or enzymes are known. The elucidation of this pathway, including the identification of the genes and enzymes involved, is vital for the demonstration, validation, and regulatory acceptance of in-situ

317

Identifying Suitable Degradation Parameters for Individual-Based Prognostics  

SciTech Connect

The ultimate goal of most prognostic systems is accurate prediction of the remaining useful life of individual systems or components based on their use and performance. Traditionally, individual-based prognostic methods use a measure of degradation to make lifetime estimates. Degradation measures may include sensed measurements, such as temperature or vibration level, or inferred measurements, such as model residuals or physics-based model predictions. Often, it is beneficial to combine several measures of degradation into a single parameter. Parameter features such as trendability, monotonicity, and prognosability can be used to compare candidate prognostic parameters to determine which is most useful for individual-based prognosis. By quantifying these features for a given parameter, the metrics can be used with any traditional optimization technique to identify an appropriate parameter. This parameter may be used with a parametric extrapolation model to make prognostic estimates for an individual unit. The proposed methods are illustrated with an application to simulated turbofan engine data.

Coble, Jamie B.; Hines, Wes

2012-09-30T23:59:59.000Z

318

JGI - Why Sequence Terephthalate-Degrading Microbial Community?  

NLE Websites -- All DOE Office Websites (Extended Search)

a Terephthalate-Degrading Microbial Community? a Terephthalate-Degrading Microbial Community? Every year, enormous amounts of high-strength terephthalate-containing wastewater are produced as a byproduct of the plastics industry. The wastewater is currently treated by using anaerobic biological treatment processes that involve mesophilic (moderate-temperature-loving) microbes growing at 35-37°C. Recently, a thermophilic (heating-loving) terephthalate-degrading community growing at around 55°C has been developed in a lab-scale bioreactor as a more efficient alternative to the mesophilic process. Metagenomic characterization of the thermophilic bioreactor community, followed by perturbation studies, may lead to an optimized process, which will have significant impact on the plastic production industry in terms of wastewater treatment costs and operational

319

Single channel flow blockage accident phenomena identification and ranking table (PIRT) for the advanced Candu reactor  

SciTech Connect

The Advanced Candu Reactor (ACRTM) is an evolutionary advancement of the current Candu 6{sup R} reactor, aimed at producing electrical power for a capital cost and at a unit-energy cost significantly less than that of the current reactor designs. The ACR retains the modular concept of horizontal fuel channels surrounded by a heavy water moderator, as with all Candu reactors. However, ACR uses slightly enriched uranium (SEU) fuel, compared to the natural uranium used in Candu 6. This achieves the twin goals of improved economics (e.g., via reductions in the heavy water requirements and the use of a light water coolant), as well as improved safety. This paper documents the results of Phenomena Identification and Ranking Table (PIRT) results for a very limited frequency, beyond design basis event of the ACR design. This PIRT is developed in a highly structured process of expert elicitation that is well supported by experimental data and analytical results. The single-channel flow blockage event in an ACR reactor assumes a severe flow blockage of one of the reactor fuel channels, which leads to a reduction of the flow in the affected channel, leading to fuel cladding and fuel temperature increase. The paper outlines the design characteristics of the ACR reactor that impact the PIRT process and computer code applicability. It also describes the flow blockage phenomena, lists all components and systems that have an important role during the event, discusses the PIRT process and results, and presents the finalized PIRT tables. (authors)

Popov, N.K.; Abdul-Razzak, A.; Snell, V.G.; Langman, V. [Atomic Energy of Canada Ltd., 2251 Speakman Drive, Mississauga, Ontario, L5K 1B2 (Canada); Sills, H. [Consultant, Deep River, Ontario (Canada)

2004-07-01T23:59:59.000Z

320

Fundamentals of Melt-Water Interfacial Transport Phenomena: Improved Understanding for Innovative Safety Technologies in ALWRs  

SciTech Connect

The interaction and mixing of high-temperature melt and water is the important technical issue in the safety assessment of water-cooled reactors to achieve ultimate core coolability. For specific advanced light water reactor (ALWR) designs, deliberate mixing of the core-melt and water is being considered as a mitigative measure, to assure ex-vessel core coolability. The goal of this work is to provide the fundamental understanding needed for melt-water interfacial transport phenomena, thus enabling the development of innovative safety technologies for advanced LWRs that will assure ex-vessel core coolability. The work considers the ex-vessel coolability phenomena in two stages. The first stage is the melt quenching process and is being addressed by Argonne National Lab and University of Wisconsin in modified test facilities. Given a quenched melt in the form of solidified debris, the second stage is to characterize the long-term debris cooling process and is being addressed by Korean Maritime University in via test and analyses. We then address the appropriate scaling and design methodologies for reactor applications.

M. Anderson; M. Corradini; K.Y. Bank; R. Bonazza; D. Cho

2005-04-26T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Renormalization group-induced phenomena of top pairs from four-quark effective operators  

E-Print Network (OSTI)

We study the renormalization group(RG) evolution of four-quark operators that contribute to the top pair production. In particular, we focus on the cases in which certain observables are \\emph{first} induced from the one-loop RG while being absent at tree-level. From the operator mixing pattern, we classify all such RG-induced phenomena and underlying models that can induce them. We then calculate the full one-loop QCD RG evolution as the leading estimator of the effects and address the question of which RG-induced phenomena have largest and observable effects. The answer is related to the color structure of QCD. The studied topics include the RG-induction of top asymmetries, polarizations and polarization mixings as well as issues arising at this order. The RG-induction of top asymmetries is further compared with the generation of asymmetries from QCD and QED at one-loop order. We finally discuss the validity of using the RG as the proxy of one-loop effects on the top pair production. As an aside, we clarify the often-studied relations between top pair observables.

Sunghoon Jung; P. Ko; Yeo Woong Yoon; Chaehyun Yu

2014-06-18T23:59:59.000Z

322

Renormalization group-induced phenomena of top pairs from four-quark effective operators  

E-Print Network (OSTI)

We study the renormalization group(RG) evolution of four-quark operators that contribute to the top pair production. In particular, we focus on the cases in which certain observables are first induced from the one-loop RG while being absent at tree-level. From the operator mixing pattern, we classify all such RG-induced phenomena and underlying models that can induce them. We then calculate the full one-loop QCD RG evolution as the leading estimator of the effects and address the question of which RG-induced phenomena have largest and observable effects. The answer is related to the color structure of QCD. The studied topics include the RG-induction of top asymmetries, polarizations and polarization mixings as well as issues arising at this order. The RG-induction of top asymmetries is further compared with the generation of asymmetries from QCD and QED at one-loop order. We finally discuss the validity of using the RG as the proxy of one-loop effects on the top pair production. As an aside, we clarify the of...

Jung, Sunghoon; Yoon, Yeo Woong; Yu, Chaehyun

2014-01-01T23:59:59.000Z

323

Effects of sediment resuspension on the degradation of phenanthrene  

SciTech Connect

Degradation of bulk organic matter in sediments is enhanced by oxic/anoxic cycling, a feature common in coastal sediments which are resuspended into overlying waters. The authors are examining the effect of periodic cycling of sediment between an oxic water column and a reducing sediment bed on polycyclic aromatic hydrocarbon (PAH) degradation by altering resuspension frequency in controlled laboratory exposures. Rates of initial degradation in coastal sediment have been studied for {sup 14}C-labeled phenanthrene in sediments that were suspended at the following frequencies: 12/day, 6/day, 1/day, 0.25/day and 0/day in liter-sized flow through chambers. Results to date show that degradation rates are initially log linear, with the greatest initial rates (2.4--2.7%/day) occurring in the first three treatments. In treatments resuspended less frequently, this rate decreases with time and is followed at 10--12 days, by another rate increase, which may indicate the stimulation of a bacterial subpopulation. Rates of PAH mineralization are tied to the lability and mineralization of other pools of sediment organic matter, that in turn are also affected also by oxic/anoxic cycling. Addition of fresh diatom detritus stimulated the rates of phenanthrene degradation in resuspension experiments where labile organic matter had already been consumed and microbial activity was low; in contrast diatom addition depressed phenanthrene degradation in sediment exposures with more labile organic matter remaining. The authors are further addressing the behavior of phenanthrene in exposures where they vary the concentration of initial phenanthrene and the concentration and nature of co-substrates.

LeBlanc, L.A.; Gulnick, J.; Brownawell, B.J.; Taylor, G.T. [State Univ. of New York, Stony Brook, NY (United States). Marine Sciences Research Center

1995-12-31T23:59:59.000Z

324

Eurographics Workshop on Natural Phenomena (2005) E. Galin, P. Poulin (Editors)  

E-Print Network (OSTI)

.g. water trans- portation or wind. On the other hand some algorithms gen- erate the eroded terrain from are simply displaced around the actual point if the local inclination is greater than a specified material be dissolved, transported and deposited. Now in the simulation, depending on the local inclination and water

Reiterer, Harald

325

Sludge, fuel degradation and reducing fouling on heat exchangers  

SciTech Connect

Brookhaven National Laboratory, under contract to the US Department of Energy, operates an oil heat research primarily to lower energy consumption in the 12 million oil heated homes in the US. The program objectives include: Improve steady state efficiency of oil heating equipment, Improve seasonal efficiencies, Eliminate or minimize factors which tend to degrade system performance. This paper provides an overview of the status of three specific projects which fall under the above objectives. This includes our fuel quality project, oil appliance venting and a project addressing efficiency degradation due to soot fouling of heat exchangers.

Butcher, T.; Litzke, Wai Lin; Krajewski, R.; Celebi, Y.

1992-02-01T23:59:59.000Z

326

Degradation of Dome Cutting Minerals in Hanford Waste - 13100  

SciTech Connect

At the Hanford Tank Farms, recent changes in retrieval technology require cutting new risers in several single-shell tanks. The Hanford Tank Farm Operator is using water jet technology with abrasive silicate minerals such as garnet or olivine to cut through the concrete and rebar dome. The abrasiveness of these minerals, which become part of the high-level waste stream, may enhance the erosion of waste processing equipment. However, garnet and olivine are not thermodynamically stable in Hanford waste, slowly degrading over time. How likely these materials are to dissolve completely in the waste before the waste is processed in the Waste Treatment and Immobilization Plant can be evaluated using theoretical analysis for olivine and collected direct experimental evidence for garnet. Based on an extensive literature study, a large number of primary silicates decompose into sodalite and cancrinite when exposed to Hanford waste. Given sufficient time, the sodalite also degrades into cancrinite. Even though cancrinite has not been directly added to any Hanford tanks during process times, it is the most common silicate observed in current Hanford waste. By analogy, olivine and garnet are expected to ultimately also decompose into cancrinite. Garnet used in a concrete cutting demonstration was immersed in a simulated supernate representing the estimated composition of the liquid retrieving waste from Hanford tank 241-C-107 at both ambient and elevated temperatures. This simulant was amended with extra NaOH to determine if adding caustic would help enhance the degradation rate of garnet. The results showed that the garnet degradation rate was highest at the highest NaOH concentration and temperature. At the end of 12 weeks, however, the garnet grains were mostly intact, even when immersed in 2 molar NaOH at 80 deg. C. Cancrinite was identified as the degradation product on the surface of the garnet grains. In the case of olivine, the rate of degradation in the high-pH regimes of a waste tank is expected to depend on two main parameters: carbonate is expected to slow olivine degradation rates, whereas hydroxide is expected to enhance olivine dissolution rates. Which of these two competing dissolution drivers will have a larger impact on the dissolution rate in the specific environment of a waste tank is currently not identifiable. In general, cancrinite is much smaller and less hard than either olivine or garnet, so would be expected to be less erosive to processing equipment. Complete degradation of either garnet or olivine prior to being processed at the Waste Treatment and Immobilization Plant cannot be confirmed, however. (authors)

Reynolds, Jacob G.; Cooke, Gary A.; Huber, Heinz J. [Washington River Protection Solutions, LLC, P.O. Box 850, Richland, WA 99352 (United States)] [Washington River Protection Solutions, LLC, P.O. Box 850, Richland, WA 99352 (United States)

2013-07-01T23:59:59.000Z

327

Materials Degradation and Detection (MD2): Deep Dive Final Report  

SciTech Connect

An effort is underway at Pacific Northwest National Laboratory (PNNL) to develop a fundamental and general framework to foster the science and technology needed to support real-time monitoring of early degradation in materials used in the production of nuclear power. The development of such a capability would represent a timely solution to the mounting issues operators face with materials degradation in nuclear power plants. The envisioned framework consists of three primary and interconnected “thrust” areas including 1) microstructural science, 2) behavior assessment, and 3) monitoring and predictive capabilities. A brief state-of-the-art assessment for each of these core technology areas is discussed in the paper.

McCloy, John S.; Montgomery, Robert O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Hu, Shenyang Y.; Li, Yulan; Henager, Charles H.; Johnson, Bradley R.

2013-02-01T23:59:59.000Z

328

Degradation of dome cutting minerals in Hanford waste  

SciTech Connect

At the Hanford Tank Farms, recent changes in retrieval technology require cutting new risers in several single-shell tanks. The Hanford Tank Farm Operator is using water jet technology with abrasive silicate minerals such as garnet or olivine to cut through the concrete and rebar dome. The abrasiveness of these minerals, which become part of the high-level waste stream, may enhance the erosion of waste processing equipment. However, garnet and olivine are not thermodynamically stable in Hanford waste, slowly degrading over time. How likely these materials are to dissolve completely in the waste before the waste is processed in the Waste Treatment and Immobilization Plant can be evaluated using theoretical analysis for olivine and collected direct experimental evidence for garnet. Based on an extensive literature study, a large number of primary silicates decompose into sodalite and cancrinite when exposed to Hanford waste. Given sufficient time, the sodalite also degrades into cancrinite. Even though cancrinite has not been directly added to any Hanford tanks during process times, it is the most common silicate observed in current Hanford waste. By analogy, olivine and garnet are expected to ultimately also decompose into cancrinite. Garnet used in a concrete cutting demonstration was immersed in a simulated supernate representing the estimated composition of the liquid retrieving waste from Hanford tank 241-C-107 at both ambient and elevated temperatures. This simulant was amended with extra NaOH to determine if adding caustic would help enhance the degradation rate of garnet. The results showed that the garnet degradation rate was highest at the highest NaOH concentration and temperature. At the end of 12 weeks, however, the garnet grains were mostly intact, even when immersed in 2 molar NaOH at 80 deg C. Cancrinite was identified as the degradation product on the surface of the garnet grains. In the case of olivine, the rate of degradation in the high-pH regimes of a waste tank is expected to depend on two main parameters: carbonate is expected to slow olivine degradation rates, whereas hydroxide is expected to enhance olivine dissolution rates. Which of these two competing dissolution drivers will have a larger impact on the dissolution rate in the specific environment of a waste tank is currently not identifiable. In general, cancrinite is much smaller and less hard than either olivine or garnet, so would be expected to be less erosive to processing equipment. Complete degradation of either garnet or olivine prior to being processed at the Waste Treatment and Immobilization Plant cannot be confirmed, however.

Reynolds, Jacob G.; Huber, Heinz J.; Cooke, Gary A.

2013-01-11T23:59:59.000Z

329

Visiting Fermilab - Local Accommodations  

NLE Websites -- All DOE Office Websites (Extended Search)

Local Accommodations Local Accommodations Aurora Fox Valley Inn 2450 North Farnsworth Avenue Aurora, Illinois (Approx. 4 miles from Fermilab Wilson Hall) Telephone: 630-851-2000 Baymont Inn & Suites 1585 Naperville-Wheaton Road Naperville, Illinois (Approx. 8 miles from Fermilab Wilson Hall) Telephone: 630-357-0022 Comfort Inn & Suites 1555 E. Fabyan Parkway Geneva, IL (Approx. 4 miles from Fermilab Wilson Hall) 630-208-8811 Courtyard by Marriott 1155 E. Diehl Road Naperville, Illinois (Approx. 8 miles from Fermilab Wilson Hall) Telephone: 630-505-0550 Extended Stay America (All rooms have kitchenettes) 1575 Bond Street (Route 59 & Diehl Road) Naperville, Illinois (Approx. 7 miles from Fermilab Wilson Hall) Telephone: 630-983-0000 Lisle Hilton 3303 Corporate West Drive Lisle, Illinois

330

Position-dependent photon operators in the quantization of the electromagnetic field in dielectrics at local thermal equilibrium  

E-Print Network (OSTI)

It has very recently been suggested that asymmetric coupling of electromagnetic fields to thermal reservoirs under nonequilibrium conditions can produce unexpected oscillatory behavior in the local photon statistics in layered structures. Better understanding of the predicted phenomena could enable useful applications related to thermometry, noise filtering, and enhancing optical interactions. In this work we briefly review the field quantization and study the local steady state temperature distributions in optical cavities formed of lossless and lossy media to show that also local field temperatures exhibit oscillations that depend on position as well as the photon energy.

Mikko Partanen; Teppo Häyrynen; Jani Oksanen; Jukka Tulkki

2014-12-02T23:59:59.000Z

331

Enhanced local tomography  

DOE Patents (OSTI)

Local tomography is enhanced to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. In a first method for evaluating the value of the discontinuity, the relative attenuation data is inputted to a local tomography function .function..sub..LAMBDA. to define the location S of the density discontinuity. The asymptotic behavior of .function..sub..LAMBDA. is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA.. In a second method for evaluating the value of the discontinuity, a gradient value for a mollified local tomography function .gradient..function..sub..LAMBDA..epsilon. (x.sub.ij) is determined along the discontinuity; and the value of the jump of the density across the discontinuity curve (or surface) S is estimated from the gradient values.

Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

1996-01-01T23:59:59.000Z

332

Sustainable Energy Solutions Task 4.2: UV Degradation Prevention on Fiber-Reinforced Composite Blades  

SciTech Connect

EXECUTIVE SUMARRY Use of wind energy has expanded very quickly because of the energy prices, environmental concerns and improved efficiency of wind generators. Rather than using metal and alloy based wind turbine blades, larger size fiber (glass and carbon) reinforced composite blades have been recently utilized to increase the efficiency of the wind energy in both high and low wind potential areas. In the current composite manufacturing, pre-preg and vacuum-assisted/heat sensitive resin transfer molding and resin infusion methods are employed. However, these lighter, stiffer and stronger composite blades experience ultraviolet (UV) light degradation where polymers (epoxies and hardeners) used for the blades manufacturing absorb solar UV lights, and cause photolytic, thermo-oxidative and photo-oxidative reactions resulting in breaking of carbon-hydrogen bonds, polymer degradation and internal and external stresses. One of the main reasons is the weak protective coatings/paints on the composite blades. This process accelerates the aging and fatigue cracks, and reduces the overall mechanical properties of the blades. Thus, the lack of technology on coatings for blade manufacturing is forcing many government agencies and private companies (local and national windmill companies) to find a better solution for the composite wind blades. Kansas has a great wind potential for the future energy demand, so efficient wind generators can be an option for continuous energy production. The research goal of the present project was to develop nanocomposite coatings using various inclusions against UV degradation and corrosion, and advance the fundamental understanding of degradation (i.e., physical, chemical and physiochemical property changes) on those coatings. In pursuit of the research goal, the research objective of the present program was to investigate the effects of UV light and duration on various nanocomposites made mainly of carbon nanotubes and graphene nanoflakes, contribute the valuable information to this emerging field of advanced materials and manufacturing and advance the Kansas economy through creation of engineering knowledge and products in the wind energy. The proposed work was involved in a multidisciplinary research program that incorporates nanocomposite fabrication, advanced coating, characterization, surface and colloidal chemistry, physicochemistry, corrosion science, and analysis with a simple and effective testing methodology. The findings were closely related to our hypothesis and approaches that we proposed in this proposal. The data produced in the study offered to advance the physical understanding of the behavior of nanostructured materials for the prevention of UV light at different exposure time and salt fogging. Founding of this proposal enabled the first UV resistive nanocomposite corrosion coating effort in Kansas to impact the local and national wind mill industry. Results of this program provided valuable opportunities for the multidisciplinary training of undergraduate and graduate students at Wichita State University (WSU), as well as a number of aircraft companies (e.g., Cessna, Hawker Beechcraft, Spirit, Boeing and Bombardier/Learjet) and other local and regional industries.

Janet M. Twomey, PhD

2010-04-30T23:59:59.000Z

333

Microbial degradation of n-alkyl tetrahydrothiophenes found in petroleum  

SciTech Connect

Although n-alkyl-substituted tetrahydrothiophenes are found in nonbiodegraded petroleums, they are not found in petroleums which have undergone biodegradation in their reservoirs. These observations suggested that this group of compounds with alkyl chain lengths from approximately C/sub 10/ to at least C/sub 30/ is biodegradable. Two of these sulfides, 2-n-dodecyltetrahydrothiophene (DTHT) and 2-n-undecyltetrahydrothiophene, were synthesized, and their biodegradabilities were tested by using five gram-positive, n-alkane-degrading bacterial isolates. The alkyl side chains of these compounds were oxidized, and the major intermediates found in 2-n-undecyltetrahydrothiophene- and DTHT-metabolizing cultures were 2-tetrahydrothiophenecarboxylic acid (THTC) and 2-tetrahydrothiopheneacetic acid (THTA), respectively. Four n-alkane-degrading fungi were also shown to degrade DTHT, yielding both THTA and THTC. Quantitation of tetrahydrothiophene ring-containing products in 28-day-old bacterial and fungal cultures suggested that THTC and THTA were metabolized further to unidentified products. In addition, two of the bacterial isolates were shown to degrade a mixture of n-alkyl tetrahydrothiophenes isolated from Bellshill Lake crude oil.

Fedorak, P.M.; Payzant, J.D.; Montgomery, D.S.; Westlake, D.W.S.

1988-05-01T23:59:59.000Z

334

Mutants of Arabidopsis with altered regulation of starch degradation  

SciTech Connect

Mutants of Arabidopsis thaliana (L.) Heynh. with altered regulation of starch degradation were identified by screening for plants that retained high levels of leaf starch after a period of extended darkness. The mutant phenotype was also expressed in seeds, flowers, and roots, indicating that the same pathway of starch degradation is used in these tissues. In many respects, the physiological consequences of the mutations were equivalent to the effects observed in previously characterized mutants of Arabidopsis that are unable to synthesize starch. One mutant line, which was characterized in detail, had normal levels of activity of the starch degradative enzymes {alpha}-amylase, {beta}-amylase, phosphorylase, D-enzyme, and debranching enzyme. Thus, it was not possible to establish a biochemical basis for the phenotype, which was due to a recessive mutant at a locus designated sex 1 at position 12.2 on chromosome 1. This raises the possibility that hitherto unidentified factors, altered by the mutation, play a key role in regulating or catalyzing starch degradation.

Caspar, T.; Lin, Tsanpiao; Kakefuda, G.; Benbow, L.; Preiss, J.; Somerville, C. (Michigan State Univ., East Lansing (USA))

1991-04-01T23:59:59.000Z

335

Cellulose- and Xylan-Degrading Thermophilic Anaerobic Bacteria from Biocompost  

Science Journals Connector (OSTI)

...to utilize both cellulose and xylan, including strains of Clostridium...species reported to utilize xylan, and the rate of cellulose...able to degrade cellulose, xylan, and their mixture with the...locations 40 to 50 cm below the surface and temperatures ranging from...

M. V. Sizova; J. A. Izquierdo; N. S. Panikov; L. R. Lynd

2011-02-11T23:59:59.000Z

336

Microbial degradation of petroleum hydrocarbons: an environmental perspective.  

Science Journals Connector (OSTI)

...The high- boiling n-alkanes in the wax were associated with microbial degradation...chroma- tography. During March 1971, a pipeline rupture al- lowed JP-4 jet fuel and...Environmental-Social Committee; North- ern Pipelines, Task Force on Northern Oil De- velopment...

R M Atlas

1981-03-01T23:59:59.000Z

337

A Study on Performance Degradation of PEMFC by Water Freezing  

E-Print Network (OSTI)

A Study on Performance Degradation of PEMFC by Water Freezing Workshop on Fuel Cell Operation at Sub-Freezing Temperatures Feb. 1-2, 2005 EunAe Cho Fuel Cell Research Center Korea Institute of Science and Technology #12;Fuel Cell Research Center Overview E.A. Cho et al., "Characteristics

338

Epoxy Coenzyme A Thioester Pathways for Degradation of Aromatic Compounds  

Science Journals Connector (OSTI)

...Fe-O-Fe center in stearoyl-ACP desaturase. Primary sequence identity with other diiron-oxo proteins. Biochemistry 33 :12776-12786. 29. Fuchs, G , M Boll and J Heider. 2011. Microbial degradation of aromatic compounds-from one strategy to four...

Wael Ismail; Johannes Gescher

2012-05-11T23:59:59.000Z

339

{sup 17}O NMR investigations of oxidative degradation in polymers  

SciTech Connect

We have initiated studies using both solution and solid state magic angle spinning {sup 17}O NMR for a series of oxidatively aged polymers. This short note reports the solution {sup 17}O NMR for oxidatively degraded polypropylene, ethylene-propylene-diene, polyisoprene, and nitrile rubber. Enriched O{sub 2} is used during the accelerated aging. 3 figs, 7 refs.

Alam, T.M.; Celina, M.; Assink, R.A.; Gillen, K.T.; Clough, R.L.

1996-12-31T23:59:59.000Z

340

Degradation of organic and inorganic contaminants by zero valent iron  

E-Print Network (OSTI)

/Feo. The only product observed in the reduction of 2,4-DNT was 2,4-diaminotoluene (2,4-DAT). The 2,4-DAT produced accounted for 83-100% and only 42-54% of the initial mass of 2@4.DNT under anaerobic and aerobic conditions respectively. Since no degradation of 2...

Malla, Deepak Babu

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Grid Security and Integration with Minimal Performance Degradation Sugata Sanyal  

E-Print Network (OSTI)

Grid Security and Integration with Minimal Performance Degradation Sugata Sanyal School of computational grids becoming a reality. However, the question of grid security remains one of the important open research issues. Here, we present some novel ideas about how to implement grid security, without

Sanyal, Sugata

342

Computational Modelling of Particle Degradation in Dilute Phase Pneumatic Conveyors  

E-Print Network (OSTI)

, GU2 7XH, UK {h.abou-chakra, u.tuzun}@surrey.ac.uk c The Wolfson Centre for Bulk Solids Handling Technology, University of Greenwich, Wellington Street, Woolwich, London, SE18 6PF, UK {i.bridle, m degradation during dilute phase pneumatic conveying. A numerical procedure, based on a matrix representation

Christakis, Nikolaos

343

Robust Design of Reliability Test Plans Using Degradation Measures.  

SciTech Connect

With short production development times, there is an increased need to demonstrate product reliability relatively quickly with minimal testing. In such cases there may be few if any observed failures. Thus, it may be difficult to assess reliability using the traditional reliability test plans that measure only time (or cycles) to failure. For many components, degradation measures will contain important information about performance and reliability. These measures can be used to design a minimal test plan, in terms of number of units placed on test and duration of the test, necessary to demonstrate a reliability goal. Generally, the assumption is made that the error associated with a degradation measure follows a known distribution, usually normal, although in practice cases may arise where that assumption is not valid. In this paper, we examine such degradation measures, both simulated and real, and present non-parametric methods to demonstrate reliability and to develop reliability test plans for the future production of components with this form of degradation.

Lane, Jonathan Wesley; Lane, Jonathan Wesley; Crowder, Stephen V.; Crowder, Stephen V.

2014-10-01T23:59:59.000Z

344

REINFORCEMENT LEARNING APPROACHES TO INSTRUMENTAL CONTINGENCY DEGRADATION IN RATS  

E-Print Network (OSTI)

REINFORCEMENT LEARNING APPROACHES TO INSTRUMENTAL CONTINGENCY DEGRADATION IN RATS Alain Dutech1 of the consequences of an action. Rats with lesions of the medial prefrontal cortex do not adapt their instrumental response in a Skinner box when food delivery becomes unrelated to lever pressing. This indicates a role

Boyer, Edmond

345

Local Control of Reactive Power by Distributed Photovoltaic Generators  

E-Print Network (OSTI)

High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the re...

Turitsyn, Konstantin S; Backhaus, Scott; Chertkov, Misha

2010-01-01T23:59:59.000Z

346

Natural Phenomena Hazards Design and Evaluation Criteria for Department of Energy Facilities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

0-2002 0-2002 January 2002 Superseding DOE-STD-1020-94 April 1994 DOE STANDARD NATURAL PHENOMENA HAZARDS DESIGN AND EVALUATION CRITERIA FOR DEPARTMENT OF ENERGY FACILITIES U.S. Department of Energy AREA NPHZ Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. TS This document has been reproduced from the best available copy. Available to DOE and DOE contractors from ES&H Technical Information Services, U.S. Department of Energy, (800) 473-4375, fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 605-6000. DOE-STD-1020-2002 iii Foreword This revision provides information to help meet the requirements of 10 CFR Part 830, "Nuclear

347

DOE-STD-1023-95; Natural Phenomena Hazards Assessment Criteria  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

3-95 3-95 March 1995 Change Notice No. 1 January 1996 Reaffirmed with Errata April 2002 DOE STANDARD NATURAL PHENOMENA HAZARDS ASSESSMENT CRITERIA U.S. Department of Energy AREA FACR Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Environment Safety and Health Technical Information Services, U.S. Department of Energy, (800) 473-4376, Fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650. DOE-STD-1023-95 i ERRATA FOR DOE-STD-1023-95 S FOREWORD RE-WRITTEN S ADDED REFERENCE TO 10 CFR PART 830, SSHAC (1997) AND UCRL-ID-140922

348

The Adequacy of DOE Natural Phenomena Hazards Performance Goals from an Accident Analysis Perspective  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Adequacy of DOE Natural Adequacy of DOE Natural Phenomena Hazards Performance Goals from an Accident Analysis Perspective Jeff Kimball Defense Nuclear Facilities Safety Board Staff Department of Energy NPH Conference October 26, 2011 The views expressed are solely those of the author and no official support or endorsement of this presentation by the Defense Nuclear Facilities Safety Board or the federal government is intended or should be inferred. 1 OBJECTIVE: Assess whether the DOE NPH performance goal concept as used in the Documented Safety Analysis process is adequate or needs additional guidance Background * ANS Standard 2.26 and the concept of Seismic Design Categories (SDC) and Limit States (LS) * ASCE Standard 43-05 and the concept of Design Categories

349

Two-phase power-law modeling of pipe flows displaying shear-thinning phenomena  

SciTech Connect

This paper describes work in modeling concentrated liquid-solids flows in pipes. COMMIX-M, a three-dimensional transient and steady-state computer program developed at Argonne National Laboratory, was used to compute velocities and concentrations. Based on the authors` previous analyses, some concentrated liquid-solids suspension flows display shear-thinning rather than Newtonian phenomena. Therefore, they developed a two-phase non-Newtonian power-law model that includes the effect of solids concentration on solids viscosity. With this new two-phase power-law solids-viscosity model, and with constitutive relationships for interfacial drag, virtual mass effect, shear lift force, and solids partial-slip boundary condition at the pipe walls, COMMIX-M is capable of analyzing concentrated three-dimensional liquid-solids flows.

Ding, Jianmin; Lyczkowski, R.W.; Sha, W.T.

1993-12-31T23:59:59.000Z

350

Interfacial phenomena in thermally sprayed multiwalled carbon nanotube reinforced aluminum nanocomposite  

Science Journals Connector (OSTI)

The interfacial phenomena in thermally sprayed (plasma and high-velocity oxyfuel spraying) hypereutectic Al–Si composite with multiwalled carbon nanotube (MWCNT) reinforcement have been analyzed both theoretically and experimentally. The formation of an ultrathin ?-SiC reaction layer at the interface is confirmed. Plasma sprayed composite exhibits a thicker SiC layer (?5 nm) than the high-velocity oxyfuel sprayed composite (?2 nm). The presence of SiC layer formation is also corroborated in a chemical vapor deposition experiment where Si was deposited on MWCNTs. The formation of ?-SiC is responsible for the improved wettability of the molten Al–Si alloy matrix with MWCNT reinforcement.

T. Laha; S. Kuchibhatla; S. Seal; W. Li; A. Agarwal

2007-01-01T23:59:59.000Z

351

Adaptive Event Horizon Tracking and Critical Phenomena in Binary Black Hole Coalescence  

E-Print Network (OSTI)

This work establishes critical phenomena in the topological transition of black hole coalescence. We describe and validate a computational front tracking event horizon solver, developed for generic studies of the black hole coalescence problem. We then apply this to the Kastor - Traschen axisymmetric analytic solution of the extremal Maxwell - Einstein black hole merger with cosmological constant. The surprising result of this computational analysis is a power law scaling of the minimal throat proportional to time. The minimal throat connecting the two holes obeys this power law during a short time immediately at the beginning of merger. We also confirm the behavior analytically. Thus, at least in one axisymmetric situation a critical phenomenon exists. We give arguments for a broader universality class than the restricted requirements of the Kastor - Traschen solution.

Scott A. Caveny; Richard A. Matzner

2003-04-30T23:59:59.000Z

352

On the initial phenomena occurring in lead/lead collisions at relativistic energies  

E-Print Network (OSTI)

A new study of the initial phenomena occurring in the fireball should confirm the predicted creation of a new state of nuclear matter having a lifetime of 0.17 yoctosecond and releasing an energy of 3.87 GeV. The energy-time uncertainty relation might be connected with an up to now unsuspected momentum-position uncertainty relation holding in a three-dimensional time. This new point of view leads to the interpretation of the charge of a particle as being a rotational motion in time, to a new interpretation of inertia, and to a new interpretation of the color of a particle. The transverse momentum observed in the study of the fireball might be the signature of this motion in time of the charge.

C. Ythier; G. Mouze

2012-12-13T23:59:59.000Z

353

Natural phenomena hazards performance categorization guidelines for structures, systems, and components  

SciTech Connect

The Department of Energy (DOE) requires in DOE 5480.23 the use of a ``graded approach`` in performing safety analysis and evaluation of DOE facilities for normal operating and accident conditions, including accidents caused by natural phenomena hazard (NPH) events. DOE 5480.28 uses this graded approach and requires, for the purpose of NPH design and evaluation, placing the structures, systems, and components (SSCs) comprising the DOE facilities into five performance categories. This standard is a revision to DOE-STD-1021-92, December 1992, and provides guidelines to be used for such categorization of SSCs, and recommends systematic procedures to implement these guidelines. It applies to all DOE facilities that are covered by DOE 5480.28. (JDB)

Not Available

1993-07-01T23:59:59.000Z

354

Natural phenomena hazards performance categorization guidelines for structures, systems, and components  

SciTech Connect

The Department of Energy (DOE) requires in DOE 5480.23 the use of a graded approach'' in performing safety analysis and evaluation of DOE facilities for normal operating and accident conditions, including accidents caused by natural phenomena hazard (NPH) events. DOE 5480.28 uses this graded approach and requires, for the purpose of NPH design and evaluation, placing the structures, systems, and components (SSCs) comprising the DOE facilities into five performance categories. This standard is a revision to DOE-STD-1021-92, December 1992, and provides guidelines to be used for such categorization of SSCs, and recommends systematic procedures to implement these guidelines. It applies to all DOE facilities that are covered by DOE 5480.28. (JDB)

Not Available

1993-07-01T23:59:59.000Z

355

Computational modelling of transport phenomena in high energy materials processing application: large eddy simulation and parallelisation  

Science Journals Connector (OSTI)

A comprehensive three-dimensional numerical model is presented in order to address the coupled turbulent momentum, heat and species transport during molten metal-pool convection in association with continuous evolution of solid-liquid interface typically encountered in high energy materials processing applications. The turbulent aspect is handled by a large eddy simulation (LES) model and the phase changing phenomena is taken care of by a modified enthalpy-porosity technique. The proposed finite volume based LES model is subsequently parallelised for effective computational economy. To demonstrate the effectiveness of the present model, a systematic analysis is subsequently carried out to simulate a typical high power laser surface alloying process, where the effects of turbulent transport can actually be realised.

Dipankar Chatterjee

2011-01-01T23:59:59.000Z

356

Natural Phenomena Hazards Performance Categorization Guidelines for Structures, Systems, and Components  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1-93 1-93 July 1993 Change Notice No. 1 January 1996 Reaffirmed with Errata April 2002 DOE STANDARD NATURAL PHENOMENA HAZARDS PERFORMANCE CATEGORIZATION GUIDELINES FOR STRUCTURES, SYSTEMS, AND COMPONENTS U.S. Department of Energy AREA FACR Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced from the best available copy. Available to DOE and DOE contractors from ES&H Technical Information Services, U.S. Department of Energy, (800) 473-4375, fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 605-6000. DOE-STD-1021-93 ERRATA FOR DOE-STD-1021-93 ADDED REFERENCE TO 10 CFR PART 830

357

Uncertainty methodology for the strongly coupled physical phenomena associated with annular flow  

SciTech Connect

Best-Estimate plus Uncertainty (BEPU) methods are slowly supplanting the use of deterministic analysis methods for thermal-hydraulic analyses. As the uncertainty methodologies evolve it is expected that, where both experimental techniques allow and data are available, there will be a shift to quantifying the uncertainty in increasingly more fundamental parameters. For example, for annular flow in a three-field analysis environment (vapor, liquid film, droplet), the driving parameters would be: a) film interfacial shear stress, b) droplet drag, c) droplet entrainment rate and d) droplet deposition rate. An improved annular flow modeling package was recently developed and implemented in an in-house version of the COBRA-TF best-estimate subchannel analysis tool (Lane, 2009). Significant improvement was observed in the code-to-data predictions of several steam-water annular flow tests following the implementation of this modeling package; however, to apply this model set in formal BEPU analysis requires uncertainty distributions to be determined. The unique aspect of annular flow, and the topic of the present work, is the strong coupling between the interfacial drag, entrainment and deposition phenomena. Ideally the uncertainty in each phenomenon would be isolated; however, the situation is further complicated by an inability to experimentally isolate and measure the individual rate processes (particularly entrainment rate), which results in available experimental data that are inherently integral in nature. This paper presents a methodology for isolating the individual physical phenomena of interest, to the extent that the currently available experimental data allow, and developing the corresponding uncertainty distributions for annular flow. (authors)

Lane, J. W.; Aumiller Jr, D. L. [Bettis Atomic Power Laboratory, West Mifflin, PA 15122 (United States)

2012-07-01T23:59:59.000Z

358

Medial Axis Local Planner: Local Planning for Medial Axis Roadmaps  

E-Print Network (OSTI)

implemented this local planner and have tested it in 2D and 3D rigid body and 8D and 16D fixed base articulated linkage environments. We compare MALP with a straight-line local planner (SL), a typical local planer used in motion planning that interpolated...

Manavi, Kasra Mehron

2012-07-16T23:59:59.000Z

359

Technical Potential for Local Distributed  

E-Print Network (OSTI)

the impact of high penetrations of solar PV on wholesale power markets (energy and capacity Technical Potential for Local Distributed Photovoltaics in California Preliminary.391.5100 www.ethree.com Technical Potential for Local Distributed Photovoltaics in California Preliminary

360

Generalized local emission tomography  

DOE Patents (OSTI)

Emission tomography enables locations and values of internal isotope density distributions to be determined from radiation emitted from the whole object. In the method for locating the values of discontinuities, the intensities of radiation emitted from either the whole object or a region of the object containing the discontinuities are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the isotope density discontinuity. The asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) knowing pointwise values of the attenuation coefficient within the object. In the method for determining the location of the discontinuity, the intensities of radiation emitted from an object are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the density discontinuity and the location .GAMMA. of the attenuation coefficient discontinuity. Pointwise values of the attenuation coefficient within the object need not be known in this case.

Katsevich, Alexander J. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

In Situ Hydrocarbon Degradation by Indigenous Nearshore Bacterial Populations  

SciTech Connect

Potential episodic hydrocarbon inputs associated with oil mining and transportation together with chronic introduction of hydrocarbons via urban runoff into the relatively pristine coastal Florida waters poses a significant threat to Florida's fragile marine environment. It is therefore important to understand the extent to which indigenous bacterial populations are able to degrade hydrocarbon compounds and also determine factors that could potentially control and promote the rate at which these compounds are broken down in situ. Previous controlled laboratory experiments carried out by our research group demonstrated that separately both photo-oxidation and cometabolism stimulate bacterial hydrocarbon degradation by natural bacterial assemblages collected from a chronically petroleum contaminated site in Bayboro Bay, Florida. Additionally, we also demonstrated that stable carbon and radiocarbon abundances of respired CO{sub 2} could be used to trace in situ hydrocarbon degradation by indigenous bacterial populations at this same site. This current proposal had two main objectives: (a) to evaluate the cumulative impact of cometabolism and photo-oxidation on hydrocarbon degradation by natural bacterial assemblages collected the same site in Bayboro Bay, Florida and (b) to determine if in situ hydrocarbon degradation by indigenous bacterial populations this site could be traced using natural radiocarbon and stable carbon abundances of assimilated bacterial carbon. Funds were used for 2 years of full support for one ESI Ph.D. student, April Croxton. To address our first objective a series of closed system bacterial incubations were carried out using photo-oxidized petroleum and pinfish (i.e. cometabolite). Bacterial production of CO{sub 2} was used as the indicator of hydrocarbon degradation and {delta}{sup 13}C analysis of the resultant CO{sub 2} was used to evaluate the source of the respired CO{sub 2} (i.e. petroleum hydrocarbons or the pinfish cometabolite). Results from these time series experiments demonstrated that short-term exposure of petroleum to UV light enhanced hydrocarbon degradation by 48% over that observed for non-photo-oxidized petroleum. Despite the greater bio-availability of the photo-oxidized over the non-photo-oxidized petroleum, an initial lag in CO{sub 2} production was observed indicating potential phototoxicity of the photo- by-products. {delta}{sup 13}C analysis and mass balance calculations reveal that co-metabolism with pinfish resulted in increased hydrocarbon degradation for both photo-oxidized and non-photo-oxidized petroleum each by over 100%. These results demonstrate the cumulative effect of photo-oxidation and co-metabolism on petroleum hydrocarbon degradation by natural bacterial populations indigenous to systems chronically impacted by hydrocarbon input. To address the second objective of this proposal bacterial concentrates were collected from Bayboro Harbor in April 2001 for nucleic acid extraction and subsequent natural radiocarbon abundance analyses. Unfortunately, however, all of these samples were lost due to a faulty compressor in our -70 freezer. The freezer was subsequently repaired and samples were again collected from Bayboro Harbor in June 2002 and again December 2002. Several attempts were made to extract the nucleic acid samples--however, the student was not able to successfully extract and an adequate amount of uncontaminated nucleic acid samples for subsequent natural radiocarbon abundance measurements of the bacterial carbon by accelerator mass spectrometry (i.e. require at least 50 {micro}g carbon for AMS measurement). Consequently, we were not able to address the second objective of this proposed work.

Cherrier, J.

2005-05-16T23:59:59.000Z

362

Local Option - Local Improvement Districts | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Local Option - Local Improvement Districts Local Option - Local Improvement Districts Local Option - Local Improvement Districts < Back Eligibility Commercial Industrial Multi-Family Residential Residential Program Info State Oregon Program Type PACE Financing Provider Oregon Department of Energy '''''Note: The Federal Housing Financing Agency (FHFA) issued a [http://www.fhfa.gov/webfiles/15884/PACESTMT7610.pdf statement] in July 2010 concerning the senior lien status associated with most PACE programs. In response to the FHFA statement, most local PACE programs have been suspended until further clarification is provided. ''''' Property-Assessed Clean Energy (PACE) financing effectively allows property owners to borrow money to pay for energy improvements. The amount borrowed is typically repaid via a special assessment on the property over a period

363

Environmental consequences of postulated plutonium releases from Exxon Nuclear MOFP, Richland, Washington, as a result of severe natural phenomena  

SciTech Connect

Potential environmental consequences in terms of radiation dose to people are presented for postulated plutonium releases caused by severe natural phenomena at the Exxon Nuclear Company Mixed Oxide Fabrication Plant (MOFP), Richland, Washington. The severe natural phenomena considered are earthquakes, tornadoes, high straight-line winds, and floods. Maximum plutonium deposition values are given for significant locations around the site. All important potential exposure pathways are examined. The most likely 50-year committed dose equivalents are given for the maximum-exposed individual and the population within a 50-mile radius of the plant. The maximum plutonium deposition values most likely to occur offsite are also given.

Jamison, J.D.; Watson, E.C.

1980-02-01T23:59:59.000Z

364

Corrosion-induced degradation of GaAs PHEMTs under operation in high humidity conditions  

E-Print Network (OSTI)

We have comprehensively investigated the degradation mechanism of AlGaAs/InGaAs pseudomorphic high-electron-mobility transistors (PHEMTs) under operation in high humidity conditions. PHEMTs degradation under high humidity ...

Hisaka, Takayuki

365

Diverse mechanisms of pectic polysaccharide degradation distinguished in fruit cell walls in vivo   

E-Print Network (OSTI)

Cell wall loosening and degradation are important processes in major stages of plant development including fruit ripening. Three main mechanisms have been proposed to contribute towards cell wall polysaccharide degradation ...

Othman, Babul Airianah

2012-11-30T23:59:59.000Z

366

The effects of degraded oil and pre-frying treatments on the quality of tortilla chips  

E-Print Network (OSTI)

Refined soybean oils were degraded at 190C for 60 hours. It was observed that degradation time correlated well with free fatty acid contents, total polar materials, convective heat transfer coefficient, color, specific gravity, viscosity...

Tseng, Yi-Chang

1995-01-01T23:59:59.000Z

367

Polymer electrolyte fuel cell performance degradation at different synchrotron beam intensities  

Science Journals Connector (OSTI)

The dependency of beam intensity on the performance degradation of polymer electrolyte fuel cells during X-ray imaging experiments at the Tomcat beamline of the Swiss Light Source is reported and the underlying degradation mechanisms are identified.

Eller, J.

2013-11-02T23:59:59.000Z

368

Mechanisms of accelerated degradation in the front cells of PEMFC stacks and some mitigation strategies  

Science Journals Connector (OSTI)

The accelerated degradation in the front cells of a polymer electrolyte membrane fuel cell(PEMFC) stack seriously reduces the reliability and ... to find out the mechanisms of the accelerated degradation in the f...

Pengcheng Li; Pucheng Pei; Yongling He…

2013-11-01T23:59:59.000Z

369

Degradation of Metal?EDTA Complexes by Resting Cells of the Bacterial Strain DSM 9103  

Science Journals Connector (OSTI)

Degradation of Metal?EDTA Complexes by Resting Cells of the Bacterial Strain DSM 9103 ... Therefore, the influence of EDTA speciation on its utilization by the EDTA-degrading bacterial strain DSM 9103 was investigated. ...

Aidar D. Satroutdinov; Emiliya G. Dedyukhina; Tat‘yana I. Chistyakova; Margarete Witschel; Igor G. Minkevich; Valery K. Eroshin; Thomas Egli

2000-03-28T23:59:59.000Z

370

Understanding and harnessing energy-dependent proteolysis for controlled protein degradation in bacteria  

E-Print Network (OSTI)

Regulated intracellular protein degradation is critical for cellular viability. In many organisms, degradation controls cell-cycle progression, executes responses to stress-inducing environmental changes, and enables the ...

Davis, Joseph H. (Joseph Harry), III

2010-01-01T23:59:59.000Z

371

Petri-Net Simulation Model of a Nuclear Component Degradation Process , E. Zioa,b  

E-Print Network (OSTI)

1 Petri-Net Simulation Model of a Nuclear Component Degradation Process Y.F. Lia* , E. Zioa,b , Y models [2-5] and simulation models [1, 6, 7]. The analytical degradation models can be further classified

Paris-Sud XI, Université de

372

Stable local oscillator microcircuit.  

SciTech Connect

This report gives a description of the development of a Stable Local Oscillator (StaLO) Microcircuit. The StaLO accepts a 100MHz input signal and produces output signals at 1.2, 3.3, and 3.6 GHz. The circuit is built as a multi-chip module (MCM), since it makes use of integrated circuit technologies in silicon and lithium niobate as well as discrete passive components. The StaLO uses a comb generator followed by surface acoustic wave (SAW) filters. The comb generator creates a set of harmonic components of the 100MHz input signal. The SAW filters are narrow bandpass filters that are used to select the desired component and reject all others. The resulting circuit has very low sideband power levels and low phase noise (both less than -40dBc) that is limited primarily by the phase noise level of the input signal.

Brocato, Robert Wesley

2006-10-01T23:59:59.000Z

373

E-Print Network 3.0 - assess environmental degradation Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

assessment. COURSES Advanced Environmental Chemistry Advanced Topics in Air Pollution Air Pollution... and physiology of microorgan- isms involved in degradation...

374

Displacement current phenomena in the magnetically insulated transmission lines of the refurbished Z accelerator  

Science Journals Connector (OSTI)

Experimental data is presented that illustrates important displacement current phenomena in the magnetically insulated transmission lines (MITLs) of the refurbished Z accelerator [D.?V. Rose et al., Phys. Rev. ST Accel. Beams 13, 010402 (2010)]. Specifically, we show how displacement current in the MITLs causes significant differences between the accelerator current measured at the vacuum-insulator stack (at a radial position of about 1.6 m from the Z axis of symmetry) and the accelerator current measured at the load (at a radial position of about 6 cm from the Z axis of symmetry). The importance of accounting for these differences was first emphasized by Jennings et al. [C.?A. Jennings et al., IEEE Trans. Plasma Sci. 38, 529 (2010)], who calculated them using a full transmission-line-equivalent model of the four-level MITL system. However, in the data presented by Jennings et al., many of the interesting displacement current phenomena were obscured by parasitic current losses that occurred between the vacuum-insulator stack and the load (e.g., electron flow across the anode-cathode gap). By contrast, the data presented herein contain very little parasitic current loss, and thus for these low-loss experiments we are able to demonstrate that the differences between the current measured at the stack and the current measured at the load are due primarily to the displacement current that results from the shunt capacitance of the MITLs (about 8.41 nF total). Demonstrating this is important because displacement current is an energy storage mechanism, where energy is stored in the MITL electric fields and can later be used by the system. Thus, even for higher-loss experiments, the differences between the current measured at the stack and the current measured at the load are often largely due to energy storage and subsequent release, as opposed to being due solely to some combination of measurement error and current loss in the MITLs and/or double post-hole convolute. Displacement current also explains why the current measured downstream of the MITLs (i.e., the load current) often exceeds the current measured upstream of the MITLs (i.e., the stack current) at various times in the power pulse (this particular phenomenon was initially thought to be due to timing and/or calibration errors). To facilitate a better understanding of these phenomena, we also introduce and analyze a simple LC circuit model of the MITLs. This model is easily implemented as a simple drive circuit in simulation codes, which has now been done for the LASNEX code [G.?B. Zimmerman and W.?L. Kruer, Comments Plasma Phys. Controlled Fusion 2, 51 (1975)] at Sandia, as well as for simpler MATLAB®-based codes at Sandia. An example of this LC model used as a drive circuit will also be presented.

R. D. McBride; C. A. Jennings; R. A. Vesey; G. A. Rochau; M. E. Savage; W. A. Stygar; M. E. Cuneo; D. B. Sinars; M. Jones; K. R. LeChien; M. R. Lopez; J. K. Moore; K. W. Struve; T. C. Wagoner; E. M. Waisman

2010-12-27T23:59:59.000Z

375

Turbine Surface Degradation with Service and Its Effects on Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

Jeffrey Bons Jeffrey Bons Co-PIs: Iowa State University - Drs. Tom Shih and ZJ Wang University of Cincinnati - Drs. Tafi Hamed and Widen Tabakoff Air Force Research Lab - Dr. Richard Rivir SCIES Project 02- 01- SR104 DOE COOPERATIVE AGREEMENT DE-FC26-02NT41431 Tom J. George, Program Manager, DOE/NETL Richard Wenglarz, Manager of Research, SCIES Project Awarded (06/01/02, 36 Month Duration) $563,712 Total Contract Value Turbine Surface Degradation with Service and Its Effects on Performance Brigham Young University JPB/BYU/29Oct2003 BYU-UTSR-Oct03, 29 Oct 2003, JPB The Gas Turbine Community NEEDS adequate tools to estimate the associated loss in engine performance with service time. ROUGH! ARE TURBINES Surface Degradation - Increases Heat Transfer - Reduces Efficiency GAS TURBINE NEED

376

Methods for degrading or converting plant cell wall polysaccharides  

DOE Patents (OSTI)

The present invention relates to methods for converting plant cell wall polysaccharides into one or more products, comprising: treating the plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into the one or more products. The present invention also relates to methods for producing an organic substance, comprising: (a) saccharifying plant cell wall polysaccharides with an effective amount of a spent whole fermentation broth of a recombinant microorganism, wherein the recombinant microorganism expresses one or more heterologous genes encoding enzymes which degrade or convert the plant cell wall polysaccharides into saccharified material; (b) fermenting the saccharified material of step (a) with one or more fermenting microoganisms; and (c) recovering the organic substance from the fermentation.

Berka, Randy (Davis, CA); Cherry, Joel (Davis, CA)

2008-08-19T23:59:59.000Z

377

Materials Degradation Studies for High Temperature Steam Electrolysis Systems  

SciTech Connect

Experiments are currently in progress to assess the high temperature degradation behavior of materials in solid oxide electrolysis systems. This research includes the investigation of various electrolysis cell components and balance of plant materials under both anodic and cathodic gas atmospheres at temperatures up to 850°C. Current results include corrosion data for a high temperature nickel alloy used for the air-side flow field in electrolysis cells and a commercial ferritic stainless steel used as the metallic interconnect. Three different corrosion inhibiting coatings were also tested on the steel material. The samples were tested at 850ºC for 500 h in both air and H2O/H2 atmospheres. The results of this research will be used to identify degradation mechanisms and demonstrate the suitability of candidate materials for long-term operation in electrolysis cells.

Paul Demkowicz; Pavel Medvedev; Kevin DeWall; Paul Lessing

2007-06-01T23:59:59.000Z

378

Moving Beyond NDE to Proactive Management of Materials Degradation  

SciTech Connect

There is growing interest in life extensions to enable longer term operation (LTO) for both existing nuclear power plants (NPPs) and proposed new NPPs. In order to justify an initial license extension for the 40-60 year period, new non-destructive examination (NDE) approaches have been developed and deployed by NPP operators in their Aging Management Programs (AMPs). However, to achieve the goals of even longer term operation, and specifically for the USA in looking at methodologies to support subsequent license renewal periods (i.e., 60-80 years, and beyond), it is necessary to understand the capabilities of current NDE methods to detect, monitor and trend degradation and hence enable timely implementation of appropriate corrective actions. This paper discusses insights from past experience, the state-of-the-art, and current activities in the move towards providing a capacity for proactive management of materials degradation (PMMD) to support NPP LTO.

Bond, Leonard J.

2010-07-20T23:59:59.000Z

379

Moving Beyond Nondestructive Examination to Proactive Management of Materials Degradation  

SciTech Connect

There is growing interest in life extensions to enable longer term operation (LTO) for both existing nuclear power plants (NPPs) and proposed new NPPs. In order to justify an initial license extension for the 40-60 year period, new non-destructive examination (NDE) approaches have been developed and deployed by NPP operators in their Aging Management Programs (AMPs). However, to achieve the goals of even longer term operation, and specifically for the USA in looking at methodologies to support subsequent license renewal periods (i.e., 60-80 years, and beyond), it is necessary to understand the capabilities of current NDE methods to detect, monitor and trend degradation and hence enable timely implementation of appropriate corrective actions. This paper discusses insights from past experience, the state-of-the-art, and current activities in the move towards providing a capacity for proactive management of materials degradation (PMMD) to support NPP LTO.

Bond, Leonard J.

2010-07-01T23:59:59.000Z

380

Proactive Management of Materials Degradation (PMMD) and Enhanced Structural Reliability  

SciTech Connect

This paper discusses the U.S. Nuclear Regulatory Commission’s (NRC) activities to further the Proactive Management of Materials Degradation (PMMD), including those to determine the effectiveness of emerging NDE techniques. The paper discusses the first part of the development of a methodology to determine the effectiveness of these emerging NDE techniques for managing metallic degradation. This methodology draws on experience derived from evaluating techniques that have ‘emerged’ in the past. The methodology will follow five stages: a definition of inspection parameters, a technical evaluation, laboratory testing, round-robin testing, and the design of a performance demonstration program. This methodology will document the path taken for previous techniques and set a standardized course for future NDE techniques.

Doctor, Steven R.; Bond, Leonard J.; Cumblidge, Stephen E.; Hull, Amy; Malik, Shah

2009-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

An Investigation of the effect of graphite degradation on irreversible  

NLE Websites -- All DOE Office Websites (Extended Search)

An Investigation of the effect of graphite degradation on irreversible An Investigation of the effect of graphite degradation on irreversible capacity in lithium-ion cells. Title An Investigation of the effect of graphite degradation on irreversible capacity in lithium-ion cells. Publication Type Journal Article Year of Publication 2008 Authors Hardwick, Laurence J., Marek Marcinek, Leanne Beer, John B. Kerr, and Robert Kostecki Journal Electrochemical Society Volume 155 Start Page A442 Issue 6 Pagination A442-A447 Keywords chromatography, electrochemical electrodes, electrochemical impedance spectroscopy, Fourier transform spectra, graphite, infrared spectra, lithium, mass spectra, Raman spectra, scanning electron microscopy, secondary cells, sputtering, surface structure Abstract The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy, and Brunauer-Emmett-Teller measurements confirmed that Ar-ion sputtered Mag-10 electrodes display a similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle compared to fresh unaltered anodes. Impedance spectroscopy and Fourier transform infrared spectroscopy on surface-modified graphite anodes indicated the formation of a thicker and slightly more resistive solid electrolyte interphase (SEI) layer. Gas chromatography/mass spectroscopy analysis of solvent extracts from the electrodes detected the presence of new compounds with Mw on the order of 1600gmol-1 for the surface-modified electrode with no evidence of elevated Mw species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling may be responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.

382

Degradation mechanisms and accelerated testing in PEM fuel cells  

SciTech Connect

The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. Although there has been recent progress in improving durability, further improvements are needed to meet the commercialization targets. Past improvements have largely been made possible because of the fundamental understanding of the underlying degradation mechanisms. By investigating component and cell degradation modes; defining the fundamental degradation mechanisms of components and component interactions new materials can be designed to improve durability. Various factors have been shown to affect the useful life of PEM fuel cells. Other issues arise from component optimization. Operational conditions (such as impurities in either the fuel and oxidant stream), cell environment, temperature (including subfreezing exposure), pressure, current, voltage, etc.; or transient versus continuous operation, including start-up and shutdown procedures, represent other factors that can affect cell performance and durability. The need for Accelerated Stress Tests (ASTs) can be quickly understood given the target lives for fuel cell systems: 5000 hours ({approx} 7 months) for automotive, and 40,000 hrs ({approx} 4.6 years) for stationary systems. Thus testing methods that enable more rapid screening of individual components to determine their durability characteristics, such as off-line environmental testing, are needed for evaluating new component durability in a reasonable turn-around time. This allows proposed improvements in a component to be evaluated rapidly and independently, subsequently allowing rapid advancement in PEM fuel cell durability. These tests are also crucial to developers in order to make sure that they do not sacrifice durability while making improvements in costs (e.g. lower platinum group metal [PGM] loading) and performance (e.g. thinner membrane or a GDL with better water management properties). To achieve a deeper understanding and improve PEM fuel cell durability LANL is conducting research to better define fuel cell component degradation mechanisms and correlate AST measurements to component in 'real-world' situations.

Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

383

Intergranular degradation assessment via random grain boundary network analysis  

DOE Patents (OSTI)

A method is disclosed for determining the resistance of polycrystalline materials to intergranular degradation or failure (IGDF), by analyzing the random grain boundary network connectivity (RGBNC) microstructure. Analysis of the disruption of the RGBNC microstructure may be assess the effectiveness of materials processing in increasing IGDF resistance. Comparison of the RGBNC microstructures of materials exposed to extreme operating conditions to unexposed materials may be used to diagnose and predict possible onset of material failure due to

Kumar, Mukul (San Ramon, CA); Schwartz, Adam J. (Pleasanton, CA); King, Wayne E. (San Ramon, CA)

2002-01-01T23:59:59.000Z

384

Degradation process of fuel cell membrane observed by positron  

Science Journals Connector (OSTI)

To investigate degradation process due to radicals in fuel cell membrane by means of positron annihilation spectroscopy, three kinds of radicals, HO•, H• and O2•- are produced through water radiolysis. The results show that the cluster structure and proton conductivity was greatly affected by reductive radicals. This is because the oxidative radical is responsible for the dissociation of sulfonic group, whereas the reductive radical breaks down the cluster in the membrane and disrupts proton conduction, which is consistent with solution analysis.

Y Honda; Y Aoyagi; S Tojo; G Watanabe; Y Akiyama; S Nishijima

2013-01-01T23:59:59.000Z

385

Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons  

DOE Patents (OSTI)

A chlorinated aliphatic hydrocarbon-degrading microorganism, having American Type Culture Collection accession numbers ATCC 53570 and 53571, in a biologically pure culture aseptically collected from a deep subsurface habitat and enhanced, mineralizes trichloroethylene and tetrachloroethylene to HCl, H.sub.2 O and Co.sub.2 under aerobic conditions stimulated by methane, acetate, methanol, tryptone-yeast extract, propane and propane-methane.

Fliermans, Carl B. (Augusta, GA)

1989-01-01T23:59:59.000Z

386

Application of Municipal Sewage Sludge to Forest and Degraded Land  

SciTech Connect

The paper summarizes research done over a decade at the Savannah River Site and elsewhere in the South evaluating the benefits of land application of municipal wastes. Studies have demonstrated that degraded lands, ranging from borrow pits to mine spoils can be successfully revegetated using a mixture of composed municipal sewage sludge and other amendments. The studies have demonstrated a practical approach to land application and restoration.

D.H. Marx, C. R. Berry, and P. P. Kormanik

1995-09-30T23:59:59.000Z

387

Molecular Evolution and Diversity of Lignin Degrading Heme Peroxidases in the Agaricomycetes  

E-Print Network (OSTI)

Molecular Evolution and Diversity of Lignin Degrading Heme Peroxidases in the Agaricomycetes Ingo peroxidases, including the lignin degrading enzymes manganese per- oxidase (MnP), lignin peroxidase (Li Lignin peroxidase Á Versatile peroxidase Á Lignin degradation Á Agaricomycetes Á Fungi Introduction Heme

Hibbett, David S.

388

A comparative genomic analysis of the oxidative enzymes potentially involved in lignin degradation by Agaricus bisporus  

E-Print Network (OSTI)

A comparative genomic analysis of the oxidative enzymes potentially involved in lignin degradation an important role in lignin degradation. On the other hand, the expression patterns of the related CROs suggest of the global carbon cycle. This substrate is composed of lignin, hemicellulose and cellulose and is degraded

Fried, Jeremy S.

389

Phenylacetic and Phenylpropionic Acids Do Not Affect Xylan Degradation by Ruminococcus albus  

Science Journals Connector (OSTI)

...not result in improved xylan degradation or bacterial...on the bacterial cell surface. Concluding remarks...are needed to maximize xylan degradation by R. albus...Degradation and utilization of xylan by the ruminal bacteria...cellulosome-a discrete cell surface organelle of Clostridium...

Carine Reveneau; Sarah E. Adams; M. A. Cotta; M. Morrison

2003-11-01T23:59:59.000Z

390

A study of degradation of indium tin oxide thin films on glass for display applications  

Science Journals Connector (OSTI)

Indium tin oxide (ITO) has been widely used in liquid crystal displays (LCD). Contamination and moisture have proved to have the adverse effect of causing ITO corrosion/degradation. The purpose of this paper is to determine if scratching the surface ... Keywords: Accelerated degradation test, ITO corrosion, ITO degradation, Scratching

W. S. Leung; Y. C. Chan; S. M. Lui

2013-01-01T23:59:59.000Z

391

Performance degradation of Geiger-mode APDs at cryogenic temperatures  

E-Print Network (OSTI)

Two-phase Cryogenic Avalanche Detectors (CRADs) with THGEM multipliers, optically read out with Geiger-mode APDs (GAPDs), were proposed as potential technique for charge recording in rare-event experiments. In this work we report on the degradation of the GAPD performance at cryogenic temperatures revealed in the course of the study of two-phase CRAD in Ar, with combined THGEM/GAPD-matrix multiplier; the GAPDs recorded secondary scintillation photons from the THGEM holes in the Near Infrared. The degradation effect, namely the loss of the GAPD pulse amplitude, depended on the incident X-ray photon flux. The critical counting rate of photoelectrons produced at the 4.4 mm2 GAPD, degrading its performance at 87 K, was estimated as 10000 per second. This effect was shown to result from the considerable increase of the pixel quenching resistor of this CPTA-made GAPD type. Though not affecting low-rate rare-event experiments, the observed effect may impose some limitations on the performance of CRADs with GAPD-base...

Bondar, A; Dolgov, A; Shekhtman, L; Shemyakina, E; Sokolov, A; Breskin, A; Thers, D

2014-01-01T23:59:59.000Z

392

Multiple Syntrophic Interactions in a Terephthalate-Degrading Methanogenic Consortium  

SciTech Connect

Terephthalate (TA) is one of the top 50 chemicals produced worldwide. Its production results in a TA-containing wastewater that is treated by anaerobic processes through a poorly understood methanogenic syntrophy. Using metagenomics, we characterized the methanogenic consortium tinside a hyper-mesophilic (i.e., between mesophilic and thermophilic), TA-degrading bioreactor. We identified genes belonging to dominant Pelotomaculum species presumably involved in TA degradation through decarboxylation, dearomatization, and modified ?-oxidation to H{sub 2}/CO{sub 2} and acetate. These intermediates are converted to CH{sub 4}/CO{sub 2} by three novel hyper-mesophilic methanogens. Additional secondary syntrophic interactions were predicted in Thermotogae, Syntrophus and candidate phyla OP5 and WWE1 populations. The OP5 encodes genes capable of anaerobic autotrophic butyrate production and Thermotogae, Syntrophus and WWE1 have the genetic potential to oxidize butyrate to COsub 2}/H{sub 2} and acetate. These observations suggest that the TA-degrading consortium consists of additional syntrophic interactions beyond the standard H{sub 2}-producing syntroph ? methanogen partnership that may serve to improve community stability.

Lykidis, Athanasios; Chen, Chia-Lung; Tringe, Susannah G.; McHardy, Alice C.; Copeland, Alex 5; Kyrpides, Nikos C.; Hugenholtz, Philip; Liu, Wen-Tso

2010-08-05T23:59:59.000Z

393

Hydroxide Degradation Pathways for Substituted Trimethylammonium Cations: A DFT Study  

SciTech Connect

Substituted trimethylammonium cations serve as small molecule analogues for tetherable cations in anion exchange membranes. In turn, these membranes serve as the basis for alkaline membrane fuel cells by allowing facile conduction of hydroxide. As these cations are susceptible to hydroxide attack, they degrade over time and greatly limit the lifetime of the fuel cell. In this research, we performed density functional theory calculations to investigate the degradation pathways of substituted trimethylammonium cations to probe the relative durability of cation tethering strategies in alkyl and aromatic tethers. Our results show that significant changes in calculated energy barriers occur when substitution groups change. Specifically, we have found that, when available, the Hofmann elimination pathway is the most vulnerable pathway for degradation; however, this barrier is also found to depend on the carbon chain length and number of hydrogens susceptible to Hofmann elimination. S{sub N}2 barriers were also investigated for both methyl groups and substitution groups. The reported findings give important insight into potential tethering strategies for trimethylammonium cations in anion exchange membranes.

Long, H.; Kim, K.; Pivovar, B. S.

2012-05-03T23:59:59.000Z

394

Degradation characteristics of air cathode in zinc air fuel cells  

Science Journals Connector (OSTI)

Abstract The zinc air fuel cell (ZAFC) is a promising candidate for electrical energy storage and electric vehicle propulsion. However, its limited durability has become a major obstacle for its successful commercialization. In this study, 2-cell stacks, 25 cm² cells and three-electrode half-cells are constructed to experimentally investigate the degradation characteristics of the air cathode. The results of electrochemical tests reveal that the peak power density for the 25 cm2 cell with a new air cathode is 454 mW cm?2, which is twice as the value of the used air cathode. The electrochemical impedance analysis shows that both the charge transfer resistance and the mass transfer resistance of the used air cathodes have increased, suggesting that the catalyst surface area and gas diffusion coefficient have decreased significantly. Additionally, the microstructure and morphology of the catalytic layer (CL) and gas diffusion layer (GDL) are characterized by scanning electron microscopes (SEM). SEM results confirm that the micropores in CL and GDL of the used air cathode are seriously clogged, and many catalyst particles are lost. Therefore, the performance degradation is mainly due to the clogging of micropores and loss of catalyst particles. Furthermore, hypotheses of degradation mechanism and mitigation strategies for GDL and CL are discussed briefly.

Ze Ma; Pucheng Pei; Keliang Wang; Xizhong Wang; Huachi Xu; Yongfeng Liu; Guanlin peng

2015-01-01T23:59:59.000Z

395

Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman July 30, 2010 - 10:51am Addthis Joshua DeLung Matthew Coapman sat behind a computer for six years after college, selling advertising space across the country for major brands. When his company starting shutting down, he wasn't defeated - he saw an opportunity to reinvent himself and help his community as well. Changing Charlotte "I realized the biggest need in our community was energy conservation in the places we live and work," says Coapman, now two years into starting his business - Energy Tight. "I knew it would take getting dirty to do it, but having an experience with customers where we can give them a combination of comfort and value in their homes makes it worth it."

396

Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman Local Suppliers, Local Jobs: Sitting Down with Matthew Coapman July 30, 2010 - 10:51am Addthis Joshua DeLung Matthew Coapman sat behind a computer for six years after college, selling advertising space across the country for major brands. When his company starting shutting down, he wasn't defeated - he saw an opportunity to reinvent himself and help his community as well. Changing Charlotte "I realized the biggest need in our community was energy conservation in the places we live and work," says Coapman, now two years into starting his business - Energy Tight. "I knew it would take getting dirty to do it, but having an experience with customers where we can give them a combination of comfort and value in their homes makes it worth it."

397

Waste package degradation from thermal and chemical processes in performance assessments for the Yucca Mountain disposal system for spent nuclear fuel and high-level radioactive waste  

Science Journals Connector (OSTI)

Abstract This paper summarizes modeling of waste container degradation in performance assessments conducted between 1984 and 2008 to evaluate feasibility, viability, and assess compliance of a repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nevada. As understanding of the Yucca Mountain disposal system increased, modeling of container degradation evolved from a component of the source term in 1984 to a separate module describing both container and drip shield degradation in 2008. A thermal module for evaluating the influence of higher heat loads from more closely packed, large waste packages was also introduced. In addition, a module for evaluating drift chemistry was added in later \\{PAs\\} to evaluate the potential for localized corrosion of the outer barrier of the waste container composed of Alloy 22, a highly corrosion-resistant nickel–chromium–tungsten–molybdenum alloy. The uncertainty of parameters related to container degradation contributed significantly to the estimated uncertainty of performance measures (cumulative release in assessments prior to 1995 and individual dose, thereafter).

Rob P. Rechard; Joon H. Lee; Ernest L. Hardin; Charles R. Bryan

2014-01-01T23:59:59.000Z

398

Nonequilibrium phenomena and determination of plasma parameters in the hot core of the cathode region in free-burning arc discharges  

SciTech Connect

We present spectroscopic measurements of plasma parameters (electron density n{sub e}, electron temperature T{sub e}, gas temperature T{sub g}, underpopulation factor b) in the hot-core region in front of the cathode of a low-current, free-burning arc discharge in argon under atmospheric pressure. The discharge is operated in the hot-core mode, creating a hot cathode region with plasma parameters similar to high-current arcs in spite of the fact that we use comparatively low currents (less than 20 A). We use continuum emission and (optically thin) line emission to determine n{sub e} and T{sub e}. We apply relaxation measurements based on a power-interruption technique to investigate deviations from local thermodynamic equilibrium (LTE). These measurements let us determine the gas temperature T{sub g}. All measurements are performed side-on with charge-coupled-device cameras as detectors, so that all measured plasma parameters are spatially resolved after an Abel inversion. This yields the first ever spatially resolved observation of the non-LTE phenomena of the hot core in the near-cathode region of free-burning arcs. The results only partly coincide with previously published predictions and measurements in the literature.

Kuehn, Gerrit; Kock, Manfred [Institut fuer Atom- and Molekuelphysik, Abteilung Plasmaphysik, Universitaet Hannover, Germany Institut fuer Gravitationsphysik, Universitaet Hannover (Germany) and Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Hannover (Germany); Institut fuer Atom- and Molekuelphysik, Abteilung Plasmaphysik, Universitaet Hannover (Germany)

2007-01-15T23:59:59.000Z

399

Quantum Computing The fundamental goal of Science is to explain/predict natural phenomena using simple models. For example, a  

E-Print Network (OSTI)

Chapter 1 Quantum Computing The fundamental goal of Science is to explain/predict natural phenomena involve O(n) parameters, and not, say#5 n ). This requirement seems so natural and obvious that it is hardly discussed. On the other hand, the behaviour of nature at microscopic levels seems to defy

Ranade, Abhiram G.

400

How to Do Agent-Based Simulations in the Future: From Modeling Social Mechanisms to Emergent Phenomena  

E-Print Network (OSTI)

understanding of social and economic systems. While relevant also for the statistical analysis of data and data Phenomena and Interactive Systems Design Dirk Helbing1,2 and Stefano Balietti1 1 ETH Zurich, CLU E-mail: dhelbing@ethz.ch and sbalietti@ethz.ch Abstract Since the advent of computers, the natural

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401

Power variations of Schumann resonances related to El Nin~o and La Nin~a phenomena  

E-Print Network (OSTI)

Power variations of Schumann resonances related to El Nin~o and La Nin~a phenomena Heng Yang1 with the realistic conductivity profile is employed to study the intensity variations of Schumann resonances (SR and the previous studies by other authors on related subjects shows that the intensity of the Schumann resonances

Pasko, Victor

402

Long-period fading in atmospherics during severe meteorological activity and associated solar geophysical phenomena at low latitudes  

E-Print Network (OSTI)

Long-period fading in atmospherics during severe meteorological activity and associated solar activity with the solar geophysical phenomena was studied. The results are indicative of an interesting sequence of solar- terrestrial events. A tentative conclusion is reached, suggesting an origin

Boyer, Edmond

403

Onset and Subsequent Transient Phenomena of Liquid Loading in Gas Wells: Experimental Investigation Using a Large Scale Flow Loop  

E-Print Network (OSTI)

was carried out to study the onset of liquid loading and the subsequent transient phenomena, using a large scale flow loop to visualize two-phase flow regimes, and to measure pressure and liquid holdup along a 42-m long vertical tube. From this investigation...

Waltrich, Paulo

2012-10-19T23:59:59.000Z

404

Mass transport phenomena in direct methanol fuel cells T.S. Zhao*, C. Xu, R. Chen, W.W. Yang  

E-Print Network (OSTI)

Mass transport phenomena in direct methanol fuel cells T.S. Zhao*, C. Xu, R. Chen, W.W. Yang January 2009 Available online 20 February 2009 Keywords: Fuel cell Direct methanol fuel cell Mass efficient energy production has long been sought to solve energy and environmental problems. Fuel cells

Zhao, Tianshou

405

Targeted Review of Site Preparedness for Severe Natural Phenomena Evens at the Y-12 National Security Complex, February 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Site Preparedness for Severe Natural Phenomena Events at the Y-12 National Security Complex May 2011 February 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................. 1 2.0 Scope..................................................................................................................................................... 1 3.0 Background ........................................................................................................................................... 2

406

Solvation Phenomena in Dilute Solutions: Formal, Experimental Evidence, and Modeling Implications  

SciTech Connect

We review the fundamentals underlying a general molecular-based formalism for the microscopic interpretation of the solvation phenomena involving sparingly soluble solutes in compressible media, an approach that hinges around the unambiguous splitting of the species correlation function integrals into short-(finite) and long-ranged (diverging) contributions at infinite dilution, where this condition is taken as the reference system for the derivation of composition expansions. Then, we invoke the formalism (a) to illustrate the well-behaved nature of the solvation contributions to the mechanical partial molecular properties of solutes at infinite dilution, (b) to guide the development of, and provide molecular-based support to, the macroscopic modeling of high-temperature dilute aqueous-electrolyte solutions, (c) to study solvation effects on the kinetic rate constants of reactions in near-critical solvents in an attempt to understand from a microscopic perspective the macroscopic evidence regarding the thermodynamic pressure effects, and (d) to interpret the microscopic mechanism behind synergistic solvation effects involving either co-solutes or co-solvents, and provide a molecular argument on the unsuitability of the van der Waals one-fluid (vdW-1f) mixing rules for the 2 description of weakly attractive solutes in compressible solvents. Finally, we develop thermodynamically consistent perturbation expansions, around the infinite dilution reference, for the species residual properties in binary and ternary mixtures, and discuss the theoretical and modeling implications behind ad hoc first-order truncated expansions.

Chialvo, Ariel A [ORNL

2013-01-01T23:59:59.000Z

407

Hysteresis phenomena in CO catalytic oxidation system in the presence of inhomogeneities of the catalyst surface  

Science Journals Connector (OSTI)

The hysteresis phenomena in the CO catalytic oxidation system are studied by Monte Carlo simulation in the presence of the inhomogeneities of the catalyst surface. We show that the O-passivated state is destroyed due to the inhomogeneities of the surface, in contrast to the classical Ziff-Gulari-Barshad model. The defects on the surface have a significant effect on the hysteresis transition points. Most importantly, the supercritical nucleation and growth of the O adatom island during the transition from a low reactivity to a high reactivity states are closely related to the inhomogeneities of the catalyst surface. It is shown that the width of the hysteresis loop shrinks as the scan rate ?CO of yCO (the fraction of CO in gas phase) decreases, but there exists a finite width of the hysteresis loop even if ?CO becomes infinitely small. On the other hand, the width of the hysteresis loop decreases with decreasing the diffusion rate, and even the hysteresis loop may disappear for a slow diffusion. These simulation results are in good consistency with the previous relevant experimental results.

Da-yin Hua and Yu-qiang Ma

2002-12-04T23:59:59.000Z

408

Natural phenomena hazards performance categorization criteria for structures, systems, and components. [Contains references  

SciTech Connect

Department of Energy (DOE) requires in DOE 5480.23 the use of a graded approach'' in performing safety analysis and evaluation of DOE facilities for normal operating and accident conditions, including accidents caused by natural phenomena hazard (NPH) events. DOE 5480.28 uses this graded approach'' and requires, for the purpose of NPH design and evaluation, placing the structures, systems, and components (SSCS) comprising the DOE facilities into five performance categories. This Standard provides the criteria to be used for such categorization of SSCs, and recommends systematic procedures to implement these criteria. It applies to all DOE facilities that are covered by DOE 5480.28. Basic categorization criteria have been provided to determine the preliminary performance category of SSCS. These criteria are based on the system safety classification and hazard categorization/classification data obtained from the application of DOE 5480.23, DOE-STD-1027-92, and the general design criteria (DOE 6430.1B) and safety design criteria (DOE 5480.30 and 5480.NNFDC) documents (these documents are under development). The final performance category is then determined considering applicable system interaction.

Not Available

1992-12-01T23:59:59.000Z

409

Some Common Wave Phenomena Applied to an M.H.D. Anisotropic Surface Wave System  

Science Journals Connector (OSTI)

......10xf. 4. The Kelvin Ship Wave Problem The effect of a local disturbance...anisotropy relative to its effect on the ship wave pattern. It is...demonstrate clearly the effect of the anisotropy of...surface waves in the ship wave problem. However......

I. S. ROBINSON

1976-10-01T23:59:59.000Z

410

Investigating Local Degradation and Thermal Stability of Charged Nickel-Based Cathode Materials through Real-Time Electron Microscopy  

Science Journals Connector (OSTI)

The cathode part was prepared from a mixed slurry of 90 wt % active material (NCA), 6 wt % conducting carbon, and 4 wt % poly(vinylidene difluoride) (PVDF) binder in N-methylpyrrolidone (NMP) solvent. ... The observed differences in thermal decomposition behavior can be caused by a number of factors, including kinetic effects that occur during initial charge or heating, inhomogeneous dispersion of active materials, conducting agents, and polymer binder in the mixed slurry of the cathode, and the degree of electrolyte impregnation into the cathode. ... Real-time TEM has been used to describe the thermal decomposition that occurs at the surface of LixNi0.8Co0.15Al0.05O2 cathodes. ...

Sooyeon Hwang; Seung Min Kim; Seong-Min Bak; Byung-Won Cho; Kyung Yoon Chung; Jeong Yong Lee; Wonyoung Chang; Eric A. Stach

2014-08-07T23:59:59.000Z

411

Performing a local barrier operation  

DOE Patents (OSTI)

Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value of the counter, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.

Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

2014-03-04T23:59:59.000Z

412

Performing a local barrier operation  

DOE Patents (OSTI)

Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value of the counter, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.

Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

2014-03-04T23:59:59.000Z

413

Local Voltage Support from Distributed Energy Resources to Prevent Air Conditioner Motor Stalling  

SciTech Connect

Microgrid voltage collapse often happens when there is a high percentage of low inertia air-conditioning (AC) motors in the power systems. The stalling of the AC motors results in Fault Induced Delayed Voltage Recovery (FIDVR). A hybrid load model including typical building loads, AC motor loads, and other induction motor loads is built to simulate the motoring stalling phenomena. Furthermore, distributed energy resources (DE) with local voltage support capability are utilized to boost the local bus voltage during a fault, and prevent the motor stalling. The simulation results are presented. The analysis of the simulation results show that local voltage support from multiple DEs can effectively and economically solve the microgrid voltage collapse problem.

Baone, Chaitanya A [ORNL] [ORNL; Xu, Yan [ORNL] [ORNL; Kueck, John D [ORNL] [ORNL

2010-01-01T23:59:59.000Z

414

Is Bell's theorem relevant to quantum mechanics? On locality and non-commuting observables  

E-Print Network (OSTI)

Bell's theorem is a statement by which averages obtained from specific types of statistical distributions must conform to a family of inequalities. These models, in accordance with the EPR argument, provide for the simultaneous existence of quantum mechanically incompatible quantities. We first recall several contradictions arising between the assumption of a joint distribution for incompatible observables and the probability structure of quantum-mechanics, and conclude that Bell's theorem is not expected to be relevant to quantum phenomena described by non-commuting observables, irrespective of the issue of locality. Then, we try to disentangle the locality issue from the existence of joint distributions by introducing two models accounting for the EPR correlations but denying the existence of joint distributions. We will see that these models do not need to resort explicitly to non-locality: the first model relies on conservation laws for ensembles, and the second model on an equivalence class by which different configurations lead to the same physical predictions.

A. Matzkin

2009-01-12T23:59:59.000Z

415

Localization of eigenvalues with applications  

E-Print Network (OSTI)

LOCALIZATION OF EIGENVALUES WITH APPLICATIONS A Thesis by CHARLOTTE NYQUIST DE SPIEGEL Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1975... Major Subject: Mathematics LOCALIZATION OP EIGENVALUES WITH APPLICATIONS A Thesis by CHARLOTTE NYQUIST DE SPIEGEL Approved as to style and content by: ca% (Head of Department) gr (Member (Memb a (g December 1975 AB STRACT Localization...

Spiegel, Charlotte Nyquist de

1975-01-01T23:59:59.000Z

416

AGE-RELATED DEGRADATION OF NUCLEAR POWER PLANT STRUCTURES AND COMPONENTS.  

SciTech Connect

This paper summarizes and highlights the results of the initial phase of a research project on the assessment of aged and degraded structures and components important to the safe operation of nuclear power plants (NPPs). A review of age-related degradation of structures and passive components at NPPs was performed. Instances of age-related degradation have been collected and reviewed. Data were collected from plant generated documents such as Licensing Event Reports, NRC generic communications, NUREGs and industry reports. Applicable cases of degradation occurrences were reviewed and then entered into a computerized database. The results obtained from the review of degradation occurrences are summarized and discussed. Various trending analyses were performed to identify which structures and components are most affected, whether degradation occurrences are worsening, and what are the most common aging mechanisms. The paper also discusses potential aging issues and degradation-susceptible structures and passive components which would have the greatest impact on plant risk.

BRAVERMAN,J.

1999-03-29T23:59:59.000Z

417

Age-Related Degradation of Nuclear Power Plant Structures and Components  

SciTech Connect

This paper summarizes and highlights the results of the initial phase of a research project on the assessment of aged and degraded structures and components important to the safe operation of nuclear power plants (NPPs). A review of age-related degradation of structures and passive components at NPPs was performed. Instances of age-related degradation have been collected and reviewed. Data were collected from plant generated documents such as Licensing Event Reports, NRC generic communications, NUREGs and industry reports. Applicable cases of degradation occurrences were reviewed and then entered into a computerized database. The results obtained from the review of degradation occurrences are summarized and discussed. Various trending analyses were performed to identify which structures and components are most affected, whether degradation occurrences are worsening, and what was the most common aging mechanisms. The paper also discusses potential aging issues and degradation-susceptible structures and passive components which would have the greatest impact on plant risk.

Braverman, J.; Chang, T.-Y.; Chokshi, N.; Hofmayer, C.; Morante, R.; Shteyngart, S.

1999-03-29T23:59:59.000Z

418

Fundamental Understanding of Ambient and High-Temperature Plasticity Phenomena in Structural Materials in Advanced Reactors  

SciTech Connect

The goal of this research project is to develop the methods and tools necessary to link unit processes analyzed using atomistic simulations involving interaction of vacancies and interstitials with dislocations, as well as dislocation mediation at sessile junctions and interfaces as affected by radiation, with cooperative influence on higher-length scale behavior of polycrystals. These tools and methods are necessary to design and enhance radiation-induced damage-tolerant alloys. The project will achieve this goal by applying atomistic simulations to characterize unit processes of: 1. Dislocation nucleation, absorption, and desorption at interfaces 2. Vacancy production, radiation-induced segregation of substitutional Cr at defect clusters (point defect sinks) in BCC Fe-Cr ferritic/martensitic steels 3. Investigation of interaction of interstitials and vacancies with impurities (V, Nb, Ta, Mo, W, Al, Si, P, S) 4. Time evolution of swelling (cluster growth) phenomena of irradiated materials 5. Energetics and kinetics of dislocation bypass of defects formed by interstitial clustering and formation of prismatic loops, informing statistical models of continuum character with regard to processes of dislocation glide, vacancy agglomeration and swelling, climb and cross slip This project will consider the Fe, Fe-C, and Fe-Cr ferritic/martensitic material system, accounting for magnetism by choosing appropriate interatomic potentials and validating with first principles calculations. For these alloys, the rate of swelling and creep enhancement is considerably lower than that of face-centered cubic (FCC) alloys and of austenitic Fe-Cr-Mo alloys. The team will confirm mechanisms, validate simulations at various time and length scales, and improve the veracity of computational models. The proposed research?s feasibility is supported by recent modeling of radiation effects in metals and alloys, interfacial dislocation transfer reactions in nano-twinned copper, and dislocation reactions at general boundaries, along with extensive modeling cooperative effects of dislocation interactions and migration in crystals and polycrystals using continuum models.

Deo, Chaitanya; Zhu, Ting; McDowell, David

2013-11-17T23:59:59.000Z

419

The low threshold parametric decay instabilities leading to anomalous phenomena at ECRH in toroidal devices  

SciTech Connect

A possibility of 3D electron Bernstein wave trapping in intensive magnetic field aligned density fluctuation or blob in toroidal plasma is demonstrated. Semi-analytic approach for description of associated plasma cavity is developed. A mechanism of low-threshold parametric decay instability driven by 2{sup nd} harmonic extraordinary pump microwave and leading to excitation of localized electron Bernstein wave and low frequency heavily damped oscillations is proposed and analyzed.

Gusakov, E.; Popov, A.; Saveliev, A. [Ioffe Physical Technical Institute of RAS, St. Petersburg (Russian Federation)

2014-02-12T23:59:59.000Z

420

Microbial degradation of low-level radioactive waste. Final report  

SciTech Connect

The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Information has been presented by a number of researchers, which indicated that those tests may be inappropriate for examining microbial degradation of cement-solidified LLW. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program was to develop modified microbial degradation test procedures that would be more appropriate than the existing procedures for evaluation of the effects of microbiologically influenced chemical attack on cement-solidified LLW. The procedures that have been developed in this work are presented and discussed. Groups of microorganisms indigenous to LLW disposal sites were employed that can metabolically convert organic and inorganic substrates into organic and mineral acids. Such acids aggressively react with cement and can ultimately lead to structural failure. Results on the application of mechanisms inherent in microbially influenced degradation of cement-based material are the focus of this final report. Data-validated evidence of the potential for microbially influenced deterioration of cement-solidified LLW and subsequent release of radionuclides developed during this study are presented.

Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W. Jr

1996-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Degradation of Metal?Nitrilotriacetate Complexes by Chelatobacter heintzii  

Science Journals Connector (OSTI)

Synthetic chelating agents that have been co-disposed with radionuclides can lead to the contamination of groundwater with radionuclides (7, 8). ... The ability of C. heintzii to degrade NTA at concentrations ?5.23 ?M was of interest because groundwater concentrations of synthetic chelates at the Oak Ridge (8) and Maxey Flats (7, 50?52 nuclear waste sites have been detected in the micromolar (?M) range. ... Pu in trench leachates at the Maxey Flats radioactive waste disposal site exists as dissolved species, primarily Pu(IV) complexes with strong org. ...

Harvey Bolton, Jr.; Don C. Girvin; Andrew E. Plymale; Scott D. Harvey; Darla J. Workman

1996-02-26T23:59:59.000Z

422

Advanced Materials for RSOFC Dual Operation with Low Degradation  

SciTech Connect

Reversible solid oxide fuel cells (RSOFCs) are energy conversion devices. They are capable of operating in both power generation mode (SOFC) and electrolysis modes (SOEC). RSOFC can integrate renewable production of electricity and hydrogen when power generation and steam electrolysis are coupled in a system, which can turn intermittent solar and wind energy into "firm power." In this DOE EERE project, VPS continuously advanced RSOFC cell stack technology in the areas of endurance and performance. Over 20 types of RSOFC cells were developed in the project. Many of those exceeded performance (area specific resistance less than 300 mohmcm2) and endurance (degradation rate less than 4% per 1000 hours) targets in both fuel cell and electrolysis modes at 750C. One of those cells, RSOFC-7, further demonstrated the following: Steady-state electrolysis with a degradation rate of 1.5% per 1000 hours. Ultra high current electrolysis over 3 A/cm2 at 75% water electrolysis efficiency voltage of 1.67 V. Daily SOFC/SOEC cyclic test of over 600 days with a degradation rate of 1.5% per 1000 hours. Over 6000 SOFC/SOEC cycles in an accelerated 20-minute cycling with degradation less than 3% per 1000 cycles. In RSOFC stack development, a number of kW-class RSOFC stacks were developed and demonstrated the following: Steady-state electrolysis operation of over 5000 hours. Daily SOFC/SOEC cyclic test of 100 cycles. Scale up capability of using large area cells with 550 cm2 active area showing the potential for large-scale RSOFC stack development in the future. Although this project is an open-ended development project, this effort, leveraging Versa Power Systems' years of development experience, has the potential to bring renewable energy RSOFC storage systems significantly closer to commercial viability through improvements in RSOFC durability, performance, and cost. When unitized and deployed in renewable solar and wind installations, an RSOFC system can enable higher availability for intermittent renewable resources, thereby improving the commercial viability of these types of energy resources.

Eric, Tang; Tony, Wood; Sofiane, Benhaddad; Casey, Brown; Hongpeng, He; Jeff, Nelson; Oliver, Grande; Ben, Nuttall; Mark, Richards; Randy, Petri

2012-12-27T23:59:59.000Z

423

Gamma radiation induced degradation in PE-PP block copolymer  

SciTech Connect

In the present investigation, effect of gamma irradiation on the PP-PE block copolymer has been studied. The polymer has been subjected to gamma irradiation from 100 to 500 Mrad dosages. Characterization of the polymer using XRD and FTIR was done both before irradiation and after irradiation in each step. Effect of irradiation on the electrical properties of the material has also been studied. FTIR study shows that the sample loses C - C stretching mode of vibration but gains C=C stretching mode of vibration after irradiation. Present investigation clearly indicates that though the electrical conductivity increases in the material, it undergoes degradation and shows brittleness due to irradiation.

Ravi, H. R.; Sreepad, H. R.; Ahmed, Khaleel; Govindaiah, T. N. [P.G. Department of Physics, Government College (Autonomous), Mandya - 571401, Karnataka State (India)

2012-06-05T23:59:59.000Z

424

Kampung Capacity Local Solutions for  

E-Print Network (OSTI)

to come from a mixture of locally managed small-scale hydroelectricity, biogas generators and accompanying productivity and development. Political attention often comes to these communities only when larger national a larger development agenda. We examine the local and large-scale energy service debate in villages (or

Kammen, Daniel M.

425

Local control of reactive power by distributed photovoltaic generators  

SciTech Connect

High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the real power generated by the PVs. Using one adjustable parameter per circuit, we balance the requirements on power quality and desire to minimize thermal losses. Numerical analysis of two exemplary systems, with comparable total PV generation albeit a different spatial distribution, show how to adjust the optimization parameter depending on the goal. Overall, this local scheme shows excellent performance; it's capable of guaranteeing acceptable power quality and achieving significant saving in thermal losses in various situations even when the renewable generation in excess of the circuit own load, i.e. feeding power back to the higher-level system.

Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Sulc, Petr [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

426

Effects of anode flooding on the performance degradation of polymer electrolyte membrane fuel cells  

Science Journals Connector (OSTI)

Abstract Polymer electrolyte membrane fuel cell (PEMFC) stacks in a fuel cell vehicle can be inevitably exposed to harsh environments such as cold weather in winter, causing water flooding by the direct flow of condensed water to the electrodes. In this study, anode flooding was experimentally investigated with condensed water generated by cooling the anode gas line during a long-term operation (?1600 h). The results showed that the performance of the PEMFC was considerably degraded. After the long-term experiment, the thickness of the anode decreased, and the ratio of Pt to carbon in the anode increased. Moreover, repeated fuel starvation of the half-cell severely oxidized the carbon surface due to the high induced potential (>1.5 VRHE). The cyclic voltammogram of the anode in the half-cell experiments indicated that the characteristic feature of the oxidized carbon surface was similar to that of the anode in the single cell under anode flooding conditions during the long-term experiment. Therefore, repeated fuel starvation by anode flooding caused severe carbon corrosion in the anode because the electrode potential locally increased to >1.0 VRHE. Consequently, the density of the tri-phase boundary decreased due to the corrosion of carbons supporting the Pt nanoparticles in the anode.

Mansu Kim; Namgee Jung; KwangSup Eom; Sung Jong Yoo; Jin Young Kim; Jong Hyun Jang; Hyoung-Juhn Kim; Bo Ki Hong; EunAe Cho

2014-01-01T23:59:59.000Z

427

Simulation of substrate degradation in composting of sewage sludge  

SciTech Connect

To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k{sub 20} (the first-order rate constant at 20 {sup o}C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k{sub 20}, k{sub 20s} (first-order rate coefficient of slow fraction of BVS at 20 {sup o}C) of the sewage sludge were estimated as 0.082 and 0.015 d{sup -1}, respectively.

Zhang Jun [Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101 (China); Gao Ding, E-mail: gaod@igsnrr.ac.c [Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101 (China); Chen Tongbin; Zheng Guodi; Chen Jun; Ma Chuang; Guo Songlin [Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101 (China); Du Wei [Beijing GreenTech Environmental Engineering Company, Beijing 100080 (China)

2010-10-15T23:59:59.000Z

428

DEGRADATION EVALUATION OF HEAVY WATER DRUMS AND TANKS  

SciTech Connect

Heavy water with varying chemistries is currently being stored in over 6700 drums in L- and K-areas and in seven tanks in L-, K-, and C-areas. A detailed evaluation of the potential degradation of the drums and tanks, specific to their design and service conditions, has been performed to support the demonstration of their integrity throughout the desired storage period. The 55-gallon drums are of several designs with Type 304 stainless steel as the material of construction. The tanks have capacities ranging from 8000 to 45600 gallons and are made of Type 304 stainless steel. The drums and tanks were designed and fabricated to national regulations, codes and standards per procurement specifications for the Savannah River Site. The drums have had approximately 25 leakage failures over their 50+ years of use with the last drum failure occurring in 2003. The tanks have experienced no leaks to date. The failures in the drums have occurred principally near the bottom weld, which attaches the bottom to the drum sidewall. Failures have occurred by pitting, crevice and stress corrosion cracking and are attributable, in part, to the presence of chloride ions in the heavy water. Probable degradation mechanisms for the continued storage of heavy water were evaluated that could lead to future failures in the drum or tanks. This evaluation will be used to support establishment of an inspection plan which will include susceptible locations, methods, and frequencies for the drums and tanks to avoid future leakage failures.

Mickalonis, J.; Vormelker, P.

2009-07-31T23:59:59.000Z

429

Degradation of Ionic Pathway in PEM Fuel Cell Cathode  

SciTech Connect

The degradation of the ionic pathway throughout the catalyst layer in proton exchange membrane fuel cells was studied under an accelerated stress test of catalyst support (potential hold at 1.2 V). Electrochemical behaviors of the cathode based on graphitic mesoporous carbon supported Pt catalyst were examined using electrochemical impedance spectroscopy and cyclic voltammetry. Impedance data were plotted and expressed in the complex capacitance form to determine useful parameters in the transmission line model: the double-layer capacitance, peak frequency, and ionic resistance. Electrochemical surface area and hydrogen crossover current through the membrane were estimated from cyclic voltammogram, while cathode Faradaic resistance was compared with ionic resistance as a function of test time. It was observed that during an accelerated stress test of catalyst support, graphitic mesoporous carbon becomes hydrophilic which increases interfacial area between the ionomer and the catalyst up to 100 h. However, the ionic resistance in the catalyst layer drastically increases after 100 h with further carbon support oxidation. The underlying mechanism has been studied and it was found that significant degradation of ionic pathway throughout the catalyst layer due to catalyst support corrosion induces uneven hydration and mechanical stress in the ionomer.

Park, Seh Kyu; Shao, Yuyan; Wan, Haiying; Viswanathan, Vilayanur V.; Towne, Silas A.; Rieke, Peter C.; Liu, Jun; Wang, Yong

2011-11-12T23:59:59.000Z

430

Independent Oversight Review of Preparedness for Severe Natural Phenomena Events at the Portsmouth Gaseous Diffusion Plant, November 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

of of Preparedness for Severe Natural Phenomena Events at the Portsmouth Gaseous Diffusion Plant May 2011 November 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose................................................................................................................................................ 1 2.0 Scope................................................................................................................................................... 1 3.0 Background ......................................................................................................................................... 1 4.0 Methodology ....................................................................................................................................... 2

431

Final Topical Report, ''Multi-Dimensional Analysis of the Forced Bubble Dynamics Associated with Bubble Fusion Phenomena''  

SciTech Connect

A new adaptive grid, 3-D FEM hydrodynamic shock (ie, HYDRO )code called PHASTA-2C has been developed and used to investigate bubble implosion phenomena leading to ultra-high temperatures and pressures. In particular, it was shown that nearly spherical bubble compressions occur during bubble implosions and the predicted conditions associated with a recent ORNL Bubble Fusion experiment [Taleyarkhan et al, Science, March, 2002] are consistent with the occurrence of D/D fusion.

Richard T. Lahey, Jr. - PI Kenneth E. Jansen - COPI Sunitha Nagrath - Graduate Student

2002-12-02T23:59:59.000Z

432

Investigation of dynamic driving cycle effect on the degradation of proton exchange membrane fuel cell by segmented cell technology  

Science Journals Connector (OSTI)

Abstract Durability is one of the most important limiting factors for the commercialization of proton exchange membrane fuel cell (PEMFC). Fuel cells are more vulnerable to degradation under operating conditions as dynamic load cycle or start up/shut down. The purpose of this study is to evaluate influences of driving cycles on the durability of fuel cells through analyzing the degradation mechanism of a segmented cell in real time. This study demonstrates that the performance of the fuel cell significantly decreases after 200 cycles. The segmented cell technology is used to measure the local current density distribution, which shows that the current density at the exit region and the inlet region declines much faster than the other parts. Meanwhile, electro-chemical impedance spectroscopy (EIS) reveals that after 200 cycles the ohmic resistance of fuel cell increases, especially at the cathode, and electro-chemical surface area (ESA) decreases from 392 to 307 cm2 mg?1. Furthermore, scanning electron microscopy (SEM) images of the membrane–electrode assembly (MEA) in cross-section demonstrate crackle flaw on the surface of the catalyst layer and the delamination of the electrodes from the membrane. Transmission electron microscope (TEM) results also show that the Pt particle size increases distinctly after driving cycles.

R. Lin; F. Xiong; W.C. Tang; L. Técher; J.M. Zhang; J.X. Ma

2014-01-01T23:59:59.000Z

433

Localized defect modes in graphene  

Science Journals Connector (OSTI)

We study the properties of localized vibrational modes associated with structural defects in a sheet of graphene. For the examples of the Stone-Wales defects, one- and two-atom vacancies, many-atom linear vacancies, and adatoms in a honeycomb lattice, we demonstrate that the local defect modes are characterized by stable oscillations with the frequencies lying outside the linear frequency bands of an ideal graphene. In the frequency spectral density of thermal oscillations, such localized defect modes lead to the additional peaks from the right side of the frequency band of the ideal sheet of graphene, which indicate the presence of defects in the graphene flakes.

Alexander V. Savin and Yuri S. Kivshar

2013-09-11T23:59:59.000Z

434

A System Degradation Study of 445 Systems Using Year-Over-Year Performance Index Analysis  

Energy.gov (U.S. Department of Energy (DOE))

This graphic summarizes the results of a study conducted by the SunPower Corporation, to assess the median degradation of a large number of systems. This is important because solar investors need proof of low degradation. The study, a project under DOE's SunShot Initiative, makes use of year-over-year performance index change analysis, a powerful and practical technique for assessing the median degradation of a large fleet of systems, which in this case includes a sample of 445.

435

Motion Compatibility for Indoor Localization  

E-Print Network (OSTI)

Indoor localization -- a device's ability to determine its location within an extended indoor environment -- is a fundamental enabling capability for mobile context-aware applications. Many proposed applications assume ...

Park, Jun-geun

2014-08-26T23:59:59.000Z

436

Microbial Degradation in Soil Microcosms of Fuel Oil Hydrocarbons from Drilling Cuttings  

Science Journals Connector (OSTI)

Microbial Degradation in Soil Microcosms of Fuel Oil Hydrocarbons from Drilling Cuttings ... Relation between Bioavailability and Fuel Oil Hydrocarbon Composition in Contaminated Soils ...

Claude-Henri. ChaIneau; Jean-Louis. Morel; Jean. Oudot

1995-06-01T23:59:59.000Z

437

PATTERNS OF DIFFUSIBILITY OF LIGNIN AND CARBOHYDRATE DEGRADING SYSTEMS IN WOOD-ROTTING FUNGI  

E-Print Network (OSTI)

J. Biochem. 57: 405-409. lignins by Bacillus megaterium.microorganisms, Berg, B, 1975, Lignin degradation andEffects of microorganisms on lignin. Phytopathol. ~: Kirk.

Rosenberg, S. L.

2011-01-01T23:59:59.000Z

438

E-Print Network 3.0 - anaerobic 2-methylnaphthalene degradation...  

NLE Websites -- All DOE Office Websites (Extended Search)

provides a general overview of anaero- Summary: that can be degraded by bacteria. Biogas: the gas produced by anaerobic bacteria in the anaerobic digestion... at Virginia...

439

E-Print Network 3.0 - anaerobic carbon degradation Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

12;13 degradable (E... monitoring system for the anaerobic process, based on headspace gas chromatography. Submitted. Paper III Boe... on the IWA Anaerobic Digestion Model No.1...

440

Key Parameters Affecting DPF Performance Degradation and Impact on Lifetime Fuel Economy  

Energy.gov (U.S. Department of Energy (DOE))

Summarizes latest findings on impact of specific parameters affecting ash-related diesel particulate filter performance degradation and information useful to enhance performance and extend service life

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

FCV Learning Demonstration: First-Generation Vehicle Results and Factors Affecting Fuel Cell Degradation (Presentation)  

SciTech Connect

Presentaion on the FCV Learning Demonstration and factors affecting fuel cell degradation given at the Fuel Cell Seminar on October 17, 2007 in San Antonio, TX.

Wipke, K.; Sprik, S.; Kurtz, J.; Thomas, H.; Garbak, J.

2007-10-17T23:59:59.000Z

442

Anaerobic/aerobic conditions and biostimulation for enhanced chlorophenols degradation in biocathode microbial fuel cells  

Science Journals Connector (OSTI)

Anaerobic/aerobic conditions affected bacterial community composition and the subsequent chlorophenols (CPs) degradation in biocathode microbial fuel cells (MFCs). Bacterial communities acclimated with either ......

Liping Huang; Yinghong Shi; Ning Wang; Yuesheng Dong

2014-07-01T23:59:59.000Z

443

E-Print Network 3.0 - aerobic microbial degradation Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

with Land-applied Biosolids Summary: microbial degradation and eventually enter sewage sludge. Due to their presumed rapid mineralization once... - coast. The sludges...

444

E-Print Network 3.0 - atoms prevent degradation Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Grafts Summary: control exhibited the most intense phosphate peaks. Strength Degradation Atomic Absorption Spectroscopy... @gmail.com Objective: To develop a ceramic material with...

445

Degradation kinetics of aromatic organic solutes introduced into a heterogeneous aquifer  

SciTech Connect

Degradation rates of benzene, p-xylene, naphthalene, and o-dichlorobenzene have been determined in the Columbus, MS aquifer. The objective of this research was to measure the degradation of organic compounds in an aquifer, using pulse injection. Degradation rates of these compounds were calculated, and the rates were related to aquifer structure and hydrologic properties. the injection was made into the saturated zone of the unconfined aquifer. This technique is suggested for future field experiments because it distinguishes solute degradation from solute losses by sorption and evaporation and allows mass balance to be demonstrated throughout the course of the reaction in the aquifer. 18 refs., 6 figs., 3 tabs.

MacIntyre, W.G. (College of William and Mary, Gloucester Point, VA (United States)); Boggs, M. (Tennessee Valley Lab., Norris, TN (United States)); Antworth, C.P.; Stauffer, T.B. (Tyndall Air Force Base, Panama City, FL (United States))

1993-12-01T23:59:59.000Z

446

Secondary Pollutants from Ozone Reaction with Ventilation Filters and Degradation of Filter Media Additives  

E-Print Network (OSTI)

2007. Ozone removal by HVAC filters. Atmospheric Environmentozone reactions on HVAC filters cannot be ignored as aof pollutants from HVAC filters may be degradation of

Destaillats, Hugo

2012-01-01T23:59:59.000Z

447

E-Print Network 3.0 - aging-related degradation occurrences Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

41 Abstract Biological treatment methods are effective at destroying polycyclic aromatic hydro- Summary: of HMW PAH degradation is a common occurrence in nature as these...

448

Degradation Of Selected Organic Agrochemicals In Artificial Soil Slurry Systems By Anodic Fenton Treatment .  

E-Print Network (OSTI)

??This thesis investigated the application of anodic Fenton treatment to the degradation of several probe agrochemicals in model soil slurry systems. A kinetic model, called… (more)

Ye, Peng

2009-01-01T23:59:59.000Z

449

E-Print Network 3.0 - anaerobic benzene degradation Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Topic List Advanced Search Sample search results for: anaerobic benzene degradation Page: << < 1 2 3 4 5 > >> 1 Biodegradation 11: 107116, 2000. 2001 Kluwer Academic...

450

E-Print Network 3.0 - anaerobic microbial degradation Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Biodegradation 11: 107116, 2000. 2001 Kluwer Academic Publishers. Printed in the Netherlands. Summary: . 107 Anaerobic benzene degradation Derek R. Lovley Department of...

451

ITP Materials: Development of Materials Resistant to Metal Dustiing Degradation  

NLE Websites -- All DOE Office Websites (Extended Search)

INDUSTRIAL INDUSTRIAL TECHNOLOGIES PROGRAM Bringing you a prosperous future where energy is clean, abundant, reliable, and affordable Energy Efficiency and Renewable Energy U.S. Department of Energy Degradation of metallic structural compo- nents by metal dusting is a major issue in plants such as those involved in hydrogen production, ammonia synthesis, methanol reforming, and syngas (H 2 /CO mixtures) pro- duction. Metal dusting is also experienced at high temperatures in the oxidizing-carbur- izing environments that are prevalent in the heat-treating industry and in processes that involve direct reduction in the production of iron. While experiments have proved that metal dusting does occur, industries could not develop an approach to combat this problem because of a lack of understanding

452

Why sequence genome closure of lignocellulosic degrader Verrucomicrobium  

NLE Websites -- All DOE Office Websites (Extended Search)

genome closure of lignocellulosic genome closure of lignocellulosic degrader Verrucomicrobium sp. strain TAV2? Wood-feeding termites have microbial communities in their guts that are capable of converting cellulose and hemicellulose into sugars, hydrogen and methane. They can break down as much as a billion tons of raw plant biomass annually, and are of interest to bioenergy researchers hoping to harness these abilities for commercial biofuel production. To better understand the interactions and roles within the gut microbial community, the project focuses on sequencing a Termite Associated Verrucomicrobium (TAV) bacterial strain of Verrucomicrobium known as TAV2. Members of the Verrucomicrobia phylum are found in a number of environments both in water and in soils. As members of the soil microbial community,

453

Environmental aging degradation in continuous fiber ceramic composites  

SciTech Connect

The thermal stability of two-continuous fiber ceramic composites (CFCC`s) has been assessed. A Nicalon/CaO-Al{sub 2}O{sub 3}-SiO{sub 2} (CAS) glass-ceramic composite has been subjected to unstressed, oxidation heat treatments between 375 and 1200{degrees}C, after which the material was tested in flexure at room temperature. The static fatigue behavior of a chemical vapor infiltrated (CVI) Nicalon/SiC ceramic matrix composite has been assessed in air, between 425 and 1150{degrees}C, both with and without protective seal coating. Severe property degradation was observed due to oxidation of the graphite fiber/matrix interlayer in both CFCC`s.

Plucknett, K.P.; Lin, H.T.; Braski, D.N.; Becher, P.F.

1995-12-31T23:59:59.000Z

454

Thermal Degradation Studies of A Polyurethane Propellant Binder  

SciTech Connect

The thermal oxidative aging of a crosslinked hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) based polyurethane rubber, used as a polymeric binder in solid propellant grain, was investigated at temperatures from 25 C to 125 C. The changes in tensile elongation, polymer network properties and chain dynamics, mechanical hardening and density were determined with a range of techniques including modulus profiling, solvent swelling, NMR relaxation and O{sub 2} permeability measurements. We critically evaluated the Arrhenius methodology that is commonly used with a linear extrapolation of high temperature aging data using extensive data superposition and highly sensitive oxygen consumption experiments. The effects of other constituents in the propellant formulation on aging were also investigated. We conclude that crosslinking is the dominant process at higher temperatures and that the degradation involves only limited hardening in the bulk of the material. Significant curvature in the Arrhenius diagram of the oxidation rates was observed. This is similar to results for other rubber materials.

Assink, R.A.; Celina, M.; Gillen, K.T.; Graham, A.C.; Minier, L.M.

1999-06-12T23:59:59.000Z

455

Grid Security and Integration with Minimal Performance Degradation  

E-Print Network (OSTI)

Computational grids are believed to be the ultimate framework to meet the growing computational needs of the scientific community. Here, the processing power of geographically distributed resources working under different ownerships, having their own access policy, cost structure and the likes, is logically coupled to make them perform as a unified resource. The continuous increase of availability of high-bandwidth communication as well as powerful computers built of low-cost components further enhance chances of computational grids becoming a reality. However, the question of grid security remains one of the important open research issues. Here, we present some novel ideas about how to implement grid security, without appreciable performance degradation in grids. A suitable alternative to the computationally expensive encryption is suggested, which uses a key for message authentication. Methods of secure transfer and exchange of the required key(s) are also discussed.

Sanyal, Sugata; Abraham, Ajith; Paprzycki, Marcin

2011-01-01T23:59:59.000Z

456

Common causes of material degradation in buried piping  

SciTech Connect

Buried pipe may fail for innumerable reasons. Causes can be mechanical damage/breakage, chemically initiated corrosion, or a combination. Failures may originate either internally or externally on the pipe. They may be related to flaws in the design, to excessive or unanticipated internal pressure or ground level loading, and/or to poor or uncertain installation practice. Or the pipe may simply ``wear out`` in service. Steel is strong and very forgiving in underground applications, especially with regard to backfill. However, soil support developed through densification or compaction is critical for brittle concrete and vitrified clay tile pipe, and is very important for cast iron and plastic pipe. Chemistry of the soil determines whether or not it will enhance corrosion or other types of degradation. Various causes and mechanisms for deterioration of buried pipe are indicated. Some peculiarities of the different materials of construction are characterized. Repair methods and means to circumvent special problems are described.

Jenkins, C.F.

1997-01-20T23:59:59.000Z

457

Degradation of Bimetallic Model Electrocatalysts ___ an in situ XAS Study  

SciTech Connect

One of the major challenges in the development of clean energy fuel cells is the performance degradation of the electrocatalyst, which, apart from poisoning effects, can suffer from corrosion due to its exposure to a harsh environment under high potentials. In this communication, we demonstrate how interactions of Pt with a transition metal support affect not only, as commonly intended, the catalytic activity, but also the reactivity of Pt towards oxide formation or dissolution. We use two well-defined single-crystal model systems, Pt/Rh(111) and Pt/Au(111) and a unique x-ray spectroscopy technique with enhanced energy resolution to monitor the potential-dependent oxidation state of Pt, and find two markedly different oxidation mechanisms on the two different substrates. This information can be of great significance for future design of more active and more stable catalysts. We have studied the potential-induced degradation of Pt monolayer model electrocatalysts on Rh(111) and Au(111) single-crystal substrates. The anodic formation of Pt oxides was monitored using in situ high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD XAS). Although Pt was deposited on both substrates in a three-dimensional island growth mode, we observed remarkable differences during oxide formation that can only be understood in terms of strong Pt-substrate interactions throughout the Pt islands. Anodic polarization of Pt/Rh(111) up to +1.6 V vs. RHE (reversible hydrogen electrode) leads to formation an incompletely oxidized passive layer, whereas formation of PtO2 and partial Pt dissolution is observed for Pt/Au(111).

Friebel, Daniel

2011-06-22T23:59:59.000Z

458

Correlating Humidity-Dependent Ionically Conductive Surface Area with Transport Phenomena in Proton-Exchange Membranes  

SciTech Connect

The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.

He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.; Clark, Kyle; Weber, Adam Z.; Kostecki, Robert

2011-08-01T23:59:59.000Z

459

LMFBR operational and experimental local-fault experience, primarily with oxide fuel elements  

SciTech Connect

Case-by-case reviews of selective world experience with severe local faults, particularly fuel failure and fuel degradation, are reviewed for two sodium-cooled thermal reactors, several LMFBRs, and LMFBR-fuels experiments. The review summarizes fuel-failure frequency and illustrates the results of the most damaging LMFBR local-fault experiences of the last 20 years beginning with BR-5 and including DFR, BOR-60, BR2's MFBS- and Mol-loops experiments, Fermi, KNK, Rapsodie, EBR-II, and TREAT-D2. Local-fault accommodation is demonstrated and a need to more thoroughly investigate delayed-neutron and gaseous-fission-product signals is highlighted in view of uranate formation, observed blockages, and slow fuel-element failure-propagation.

Warinner, D.K.

1980-01-01T23:59:59.000Z

460

LMFBR operational and experimental in-core local-fault experience, primarily with oxide fuel elements  

SciTech Connect

Case-by-case reviews of selective world experience with severe local faults, particularly fuel failure and fuel degradation, are reviewed for two sodium-cooled thermal reactors, several LMFBRs, and LMFBR-fuels experiments. The review summarizes fuel-failure frequency and illustrates the results of the most damaging LMFBR local-fault experiences of the last 20 years beginning with BR-5 and including DFR, BOR-60, BR2's MFBS-and Mol-loops experiments, Fermi, KNK, Rapsodie, EBR-II, and TREAT-D2. Local-fault accommodation is demonstrated and a need to more thoroughly investigate delayed-neutron and gaseous-fission-product signals is highlighted in view of uranate formation, observed blockages, and slow fuel-element failure-propagation.

Warinner, D.K.

1980-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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461

Techniques to evaluate the importance of common cause degradation on reliability and safety of nuclear weapons.  

SciTech Connect

As the nuclear weapon stockpile ages, there is increased concern about common degradation ultimately leading to common cause failure of multiple weapons that could significantly impact reliability or safety. Current acceptable limits for the reliability and safety of a weapon are based on upper limits on the probability of failure of an individual item, assuming that failures among items are independent. We expanded the current acceptable limits to apply to situations with common cause failure. Then, we developed a simple screening process to quickly assess the importance of observed common degradation for both reliability and safety to determine if further action is necessary. The screening process conservatively assumes that common degradation is common cause failure. For a population with between 100 and 5000 items we applied the screening process and conclude the following. In general, for a reliability requirement specified in the Military Characteristics (MCs) for a specific weapon system, common degradation is of concern if more than 100(1-x)% of the weapons are susceptible to common degradation, where x is the required reliability expressed as a fraction. Common degradation is of concern for the safety of a weapon subsystem if more than 0.1% of the population is susceptible to common degradation. Common degradation is of concern for the safety of a weapon component or overall weapon system if two or more components/weapons in the population are susceptible to degradation. Finally, we developed a technique for detailed evaluation of common degradation leading to common cause failure for situations that are determined to be of concern using the screening process. The detailed evaluation requires that best estimates of common cause and independent failure probabilities be produced. Using these techniques, observed common degradation can be evaluated for effects on reliability and safety.

Darby, John L.

2011-05-01T23:59:59.000Z

462

Interspecies acetate transfer influences the extent of anaerobic benzoate degradation by syntrophic consortia  

SciTech Connect

Benzoate degradation by an anaerobic, syntrophic bacterium, strain SB, in coculture with Desulfovibrio strain G-11 reached a threshold value which depended on the amount of acetate added, and ranged from about 2.5 to 29.9 {mu}M. Increasing acetate concentrations also uncompetitively inhibited benzoate degradation. The apparent V{sub max} and K{sub m} for benzoate degradation decreased with increasing acetate concentration, but the benzoate degradation capacity (V{sub max}/K{sub m}) of cell suspensions remained comparable. The addition of an acetate-using bacterium to cocultures after the threshold was reached resulted in the degradation of benzoate to below the detection limit. Mathematical simulations showed that the benzoate threshold was not predicted by the inhibitory effect of acetate on benzoate degradation kinetics. With nitrate instead of sulfate as the terminal electron acceptor, no benzoate threshold was observed in the presence of 20 mM acetate even though the degradation capacity was lower with nitrate than with sulfate. When strain SB was grown with a hydrogen-using partner that had a 5-fold lower hydrogen utilization capacity, a 5 to 9-fold lower the benzoate degradation capacity was observed compared to SB/G-11 cocultures. The Gibb`s free energy for benzoate degradation was less negative in cell suspensions with threshold compared to those without threshold. These studies showed that the threshold was not a function of the inhibition of benzoate degradation capacity by acetate, or the toxicity of the undissociated form of acetate. Rather a critical or minimal Gibb`s free energy may exist where thermodynamic constraints preclude further benzoate degradation.

Warikoo, V.; McInerney, M.J.; Suflita, J.M. [and others

1997-03-01T23:59:59.000Z

463

Kinetic viscoelasticity modeling applied to degradation during carbon–carbon composite processing  

E-Print Network (OSTI)

Kinetic viscoelasticity modeling has been successfully utilized to describe phenomena during cure of thermoset based carbon fiber reinforced matrices. The basic difference from classic viscoelasticity is that the fundamental ...

Drakonakis, Vassilis M.

464

Phenomenology and physical origin of shear-localization and shear-banding in complex fluids  

E-Print Network (OSTI)

We review and compare the phenomenological aspects and physical origin of shear-localization and shear-banding in various material types, namely emulsions, suspensions, colloids, granular materials and micellar systems. It appears that shear-banding, which must be distinguished from the simple effect of coexisting static-flowing regions in yield stress fluids, occurs in the form of a progressive evolution of the local viscosity towards two significantly different values in two adjoining regions of the fluids in which the stress takes slightly different values. This suggests that from a global point of view shear-banding in these systems has a common physical origin: two physical phenomena (for example, in colloids, destructuration due to flow and restructuration due to aging) are in competition and, depending on the flow conditions, one of them becomes dominant and makes the system evolve in a specific direction.

Guillaume Ovarlez; Stéphane Rodts; Xavier Chateau; Philippe Coussot

2010-02-09T23:59:59.000Z

465

Finite Element Analysis of the Amontons-Coulomb's Model using Local and Global Friction Tests  

SciTech Connect

In spite of the abundant number of experimental friction tests that have been reported, the contact with friction modeling persists to be one of the factors that determine the effectiveness of sheet metal forming simulation. This difficulty can be understood due to the nature of the friction phenomena, which comprises the interaction of different factors connected to both sheet and tools' surfaces. Although in finite element numerical simulations friction models are commonly applied at the local level, they normally rely on parameters identified based on global experimental tests results. The aim of this study is to analyze the applicability of the Amontons-Coulomb's friction coefficient identified using complementary tests: (i) load-scanning, at the local level and (ii) draw-bead, at the global level; to the numerical simulation of sheet metal forming processes.

Oliveira, M. C.; Menezes, L. F.; Ramalho, A. [CEMUC, Department of Mechanical Engineering, University of Coimbra, Polo II, Rua Luis Reis Santos, Pinhal de Marrocos, 3030-788 Coimbra (Portugal); Alves, J. L. [Department of Mechanical Engineering, University of Minho, Campus de Azurem, 4800-058, Guimaraes (Portugal)

2011-05-04T23:59:59.000Z

466

Transient Phenomena and Impurity Relocation in SIMS Depth Profiling using Oxygen Bombardment: Pursuing the Physics to Interpret the Data [and Discussion  

Science Journals Connector (OSTI)

...research-article Transient Phenomena and Impurity Relocation in SIMS Depth Profiling using Oxygen Bombardment: Pursuing the Physics...analysis or depth profiling by secondary ion mass spectrometry (SIMS) can only be achieved, for positively charged ions, if the...

1996-01-01T23:59:59.000Z

467

An investigation of the creep phenomena exhibited by Solenhofen limestone, halite, and cement under medium confining pressures  

E-Print Network (OSTI)

BY SOLENHOFEN LIMESTONE, HALITE, AND CFMI-NT UNDFR MEPIUI CONFINING PRESSURES A THESIS Bv HALCOMBE A. KENDALL A PPROVEO AS TO STYLE AND CONTENT BY AIRMAN OF COMM TTEE EAD OF PEPARTMENT ~M* 19 8 A BSTRACT TABLE OF CONTENTS PAGE 1 INTRODUCT ION... SPECI'i NS. . FIGURE 9 . FAILURE OF HALITE CRYSTALS . . ABSTRACT THE DYNAMICS OF THE CREEP PHENOMENA OF ROCKS I S KNOWN TO BE INTER RELATED WI TH THE NATURAL ENVIROMENTAL COND IT IONG FOUND DEEP IN THE CRUST OF THE EARTH ~ AHONG THESE COND I...

Kendall, Halcombe Augustus

2012-06-07T23:59:59.000Z

468

Local non-equilibrium thermodynamics  

E-Print Network (OSTI)

Local Shannon entropy lies at the heart of modern thermodynamics, with much discussion of trajectory-dependent entropy production. When taken at both boundaries of a process in phase space, it reproduces the second law of thermodynamics over a finite time interval for small scale systems. However, given that entropy is an ensemble property, it has never been clear how one can assign such a quantity locally. Given such a fundamental omission in our knowledge, we construct a new ensemble composed of trajectories reaching an individual microstate, and show that locally defined entropy, information, and free energy are properties of the ensemble, or trajectory-independent true thermodynamic potentials. We find that the Boltzmann-Gibbs distribution and Landauer's principle can be generalized naturally as properties of the ensemble, and that trajectory-free state functions of the ensemble govern the exact mechanism of non-equilibrium relaxation.

Jinwoo, Lee

2015-01-01T23:59:59.000Z

469

Adiabatic optimization without local minima  

E-Print Network (OSTI)

Several previous works have investigated the circumstances under which quantum adiabatic optimization algorithms can tunnel out of local energy minima that trap simulated annealing or other classical local search algorithms. Here we investigate the even more basic question of whether adiabatic optimization algorithms always succeed in polynomial time for trivial optimization problems in which there are no local energy minima other than the global minimum. Surprisingly, we find a counterexample in which the potential is a single basin on a graph, but the eigenvalue gap is exponentially small as a function of the number of vertices. In this counterexample, the ground state wavefunction consists of two "lobes" separated by a region of exponentially small amplitude. Conversely, we prove if the ground state wavefunction is single-peaked then the eigenvalue gap scales at worst as one over the square of the number of vertices.

Michael Jarret; Stephen P. Jordan

2014-05-29T23:59:59.000Z

470

Trichloroethene (TCE) Degradation using Granular Activated Carbon and Zero Valent Iron Particles  

E-Print Network (OSTI)

+ZVI method 2 sample was tested for TCE removal. In addition, samples of GAC-NZVI prepared by a thermal complete degradation in 2 weeks TCE degradation and products: Methods TCE Removal Kinetics: The GAC, 23 mL of nitrogen headspace and 0.15 mg of TCE were employed to assess TCE removal kinetics. Leaching

Barthelat, Francois

471

Lignin-degrading peroxidases in Polyporales: an evolutionary survey based on 10 sequenced genomes  

E-Print Network (OSTI)

Lignin-degrading peroxidases in Polyporales: an evolutionary survey based on 10 sequenced genomes genes from the manganese peroxidase (MnP), lignin peroxidase (LiP) and versatile peroxidase (VP. Incorporation of an exposed tryptophan residue involved in oxidative degradation of lignin in a short Mn

Hibbett, David S.

472

Lignin degradation in wood-feeding insects Scott M. Geib*, Timothy R. Filley  

E-Print Network (OSTI)

Lignin degradation in wood-feeding insects Scott M. Geib*, Timothy R. Filley , Patrick G. Hatcher, Deerfield, WI, and approved July 7, 2008 (received for review May 30, 2008) The aromatic polymer lignin lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using

473

Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil  

E-Print Network (OSTI)

Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil Kristen M. DeAngelis1 Abstract Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents

Hazen, Terry

474

Rumen microbial degradation of modified lignin plants observed by electron microscopy  

E-Print Network (OSTI)

Rumen microbial degradation of modified lignin plants observed by electron microscopy C Mign6, E-Genès-Champanelle, France The microbial degradation of modified lignin tobacco (Samson variety) plants (homozygous line 40 to the corresponding cinnamyl alcohols which are the direct monomeric precursors of the lignin. Only the stems were

Paris-Sud XI, Université de

475

Genome Sequence of Streptomyces viridosporus Strain T7A ATCC 39115, a Lignin-Degrading Actinomycete  

SciTech Connect

We announce the availability of the genome sequence of Streptomyces viridosporus strain T7A ATCC 39115, a plant biomass- degrading actinomycete. This bacterium is of special interest because of its capacity to degrade lignin, an underutilized compo- nent of plants in the context of bioenergy. It has a full complement of genes for plant biomass catabolism.

Davis, Jennifer R. [Brown University; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Wei, Chia-Lin [Los Alamos National Laboratory (LANL); Han, James [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Szeto, Ernest [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Peters, Lin [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Sello, Jason K. [Brown University

2013-01-01T23:59:59.000Z

476

Complete Genome Sequence of the Cellulose-Degrading Bacterium Cellulosilyticum lentocellum  

SciTech Connect

Cellulosilyticum lentocellum DSM 5427 is an anaerobic, endospore-forming member of the Firmicutes. We describe the complete genome sequence of this cellulose-degrading bacterium; originally isolated from estuarine sediment of a river that received both domestic and paper mill waste. Comparative genomics of cellulolytic clostridia will provide insight into factors that influence degradation rates.

Miller, David A [Cornell University; Suen, Garret [University of Wisconsin, Madison; Bruce, David [Los Alamos National Laboratory (LANL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Meincke, Linda [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Fox, Brian G. [University of Wisconsin, Madison; Angert, Esther R. [Cornell University; Currie, Cameron [University of Wisconsin, Madison

2011-01-01T23:59:59.000Z

477

Mechanical Degradation Onset of Polyethylene Oxide Used as a Hydrosoluble Model Polymer  

E-Print Network (OSTI)

Mechanical Degradation Onset of Polyethylene Oxide Used as a Hydrosoluble Model Polymer Degradation Onset of Polyethylene Oxide Used as a Hydrosoluble Model Polymer for Enhanced Oil Recovery and for both dilute and semi dilute polyethylene oxide aqueous solutions. It reveals that the exponent k

Boyer, Edmond

478

Distinct Actions by Paenibacillus sp. Strain E18 ?-l-Arabinofuranosidases and Xylanase in Xylan Degradation  

Science Journals Connector (OSTI)

...alpha-l-Arabinofuranosidases and Xylanase in Xylan Degradation Pengjun Shi Xiaoyan...sequential and combined effects on xylan degradation by XynBE18, Abf43A...REFERENCES 1. Bastawde, KB . 1992. Xylan structure, microbial xylanases...fermentation using response surface methodology. Process Biochem...

Pengjun Shi; Xiaoyan Chen; Kun Meng; Huoqing Huang; Yingguo Bai; Huiying Luo; Peilong Yang; Bin Yao

2013-01-18T23:59:59.000Z

479

PhD Studentship in Environmental Fate of Amine and Amine Degradation Products  

E-Print Network (OSTI)

; Modelling the fate of amines and their by-products and estimating their air and ground level concentrationsPhD Studentship in Environmental Fate of Amine and Amine Degradation Products Imperial College and nitrosamine - nitramine degradation products emitted from a CO2 capture plant and to identify acceptable

480

Microstructural Degradation of Ni-YSZ Anodes for Solid Oxide Fuel  

E-Print Network (OSTI)

Microstructural Degradation of Ni- YSZ Anodes for Solid Oxide Fuel Cells Karl Thydén Risø-PhD-32(EN 2008 #12;Author: Karl Thydén Title: Microstructural Degradation of Ni-YSZ Anodes for Solid Oxide Fuel Cells Department: Fuel Cells and Solid State Chemistry Department Risø-PhD-32(EN) March 2008 This thesis

Note: This page contains sample records for the topic "local degradation phenomena" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

PROTON EXCHANGE MEMBRANE FUEL CELL OPERATION AND DEGRADATION IN SHORT-CIRCUIT  

E-Print Network (OSTI)

PROTON EXCHANGE MEMBRANE FUEL CELL OPERATION AND DEGRADATION IN SHORT-CIRCUIT R.E. Silvaa, b, d , F exchange membrane fuel cells, short circuit, degradation mechanism, electrochemical impedance spectroscopy an electrical short circuit of a proton exchange membrane fuel cell stack. The physical quantities in the fuel

Boyer, Edmond

482

Rheological investigation of the influence of molecular structure on natural and accelerated UV degradation  

E-Print Network (OSTI)

, KFUPM, Dhahran, Saudi Arabia Received 27 June 2007; received in revised form 27 July 2007; accepted 31 to natural and accelerated weather conditions. The degree of UV degradation of exposed samples was measured mechanism. Ã? 2007 Elsevier Ltd. All rights reserved. Keywords: Degradation; Weathering; Molecular structure

Hussein, Ibnelwaleed A.

483

Impact of Branching on the UV Degradation of metallocene LLDPE Ibnelwaleed A. Hussein1  

E-Print Network (OSTI)

& Petrochemicals, KFUPM, Dhahran, Saudi Arabia Abstract The effect of UV degradation on metallocene linear low exposed to natural weather condition. The extent of the degradation on these LLDPEs was measured; High Density polyethylene; Weathering; Branching content; Cross-linking, mechanical properties ihussein

Hussein, Ibnelwaleed A.

484

Analysis and reduction of degradation of working fluid in the Sundstrand Organic Rankine-Cycle System  

SciTech Connect

Studies on understanding the location and construction levels of oxygen in the organic Rankine cycle (ORC) unit and establishing a rate of degradation with time for toluene in an operating ORC system are presented. Work on identifying the compounds in degraded toluene and contamination removal is discussed. (MHR)

Berger, R.

1983-07-01T23:59:59.000Z

485

Characterization of Hydrocarbon-Degrading Microbial Populations in Contaminated and Pristine Alpine Soils  

Science Journals Connector (OSTI)

...oil biodegradation in freshly diesel oil-contaminated soils...48). Numbers of culturable diesel oil degraders were determined...cold-adapted oil degraders were in general greater than the numbers of...able to utilize hexadecane and diesel oil. In 17 soils, 13 to 92...

R. Margesin; D. Labbé; F. Schinner; C. W. Greer; L. G. Whyte

2003-06-01T23:59:59.000Z

486

Proton Exchange Membrane Fuel Cell degradation prediction based on Adaptive Neuro Fuzzy Inference Systems  

E-Print Network (OSTI)

Proton Exchange Membrane Fuel Cell degradation prediction based on Adaptive Neuro Fuzzy Inference online XX XX XXXX Keywords: Proton Exchange Membrane fuel cell degradation, Prognostic and Health nominal operating condition of a PEM fuel cell stack. It proposes a methodology based on Adaptive Neuro

Paris-Sud XI, Université de

487

Degradation Characteristics of Elastomeric Gasket Materials in a Simulated PEM Fuel Cell Environment  

E-Print Network (OSTI)

Degradation Characteristics of Elastomeric Gasket Materials in a Simulated PEM Fuel Cell; in revised form December 9, 2007) Polymer electrolyte membrane (PEM) fuel cell stack requires gaskets after exposure to the simulated PEM fuel cell environment over time. Keywords ATR-FTIR, degradation

Van Zee, John W.

488

Mechanism-based Representative Volume Elements (RVEs) for Predicting Property Degradations in Multiphase Materials  

SciTech Connect

Quantitative understanding of the evolving thermal-mechanical properties of a multi-phase material hinges upon the availability of quantitative statistically representative microstructure descriptions. Questions then arise as to whether a two-dimensional (2D) or a three-dimensional (3D) representative volume element (RVE) should be considered as the statistically representative microstructure. Although 3D models are more representative than 2D models in general, they are usually computationally expensive and difficult to be reconstructed. In this paper, we evaluate the accuracy of a 2D RVE in predicting the property degradations induced by different degradation mechanisms with the multiphase solid oxide fuel cell (SOFC) anode material as an example. Both 2D and 3D microstructure RVEs of the anodes are adopted to quantify the effects of two different degradation mechanisms: humidity-induced electrochemical degradation and phosphorus poisoning induced structural degradation. The predictions of the 2D model are then compared with the available experimental measurements and the results from the 3D model. It is found that the 2D model, limited by its inability of reproducing the realistic electrical percolation, is unable to accurately predict the degradation of thermo-electrical properties. On the other hand, for the phosphorus poisoning induced structural degradation, both 2D and 3D microstructures yield similar results, indicating that the 2D model is capable of providing computationally efficient yet accurate results for studying the structural degradation within the anodes.

Xu, Wei; Sun, Xin; Li, Dongsheng; Ryu, Seun; Khaleel, Mohammad A.

2013-02-01T23:59:59.000Z

489

ARM - Lesson Plans: Estimating Local Sea Level  

NLE Websites -- All DOE Office Websites (Extended Search)

Lesson Plans Lesson Plans: Estimating Local Sea Level Objective The objective is to train students' skills in observing the local environment based upon the sea level...

490

Audio localization in the Automatic Cameraman  

E-Print Network (OSTI)

Design layout of the FPGA and MEMS microphone audio captureCameraman (TAC): Software Design 1.4 Audio Localization inTDOA Manifold Chapter 3 Audio Localization . . . . . . . . .

Ettinger, Evan Ira

2010-01-01T23:59:59.000Z

491

The characteristics of voltage degradation of a proton exchange membrane fuel cell under a road operating environment  

Science Journals Connector (OSTI)

Abstract A real-life testing experiment of a proton exchange membrane fuel cell (PEMFC) and the basic characteristics of its voltage degradation are presented. A general package radio system (GPRS)-based remote monitoring system was used as the data acquisition method, and the non-linear regression method was used to estimate PEMFC's polarization curve within specific iso-interval periods. The voltage degradation rate was calculated using the differential method, and its average level was also analyzed. The experimental results indicated that the voltage degradation rate at a specific current density featured a bathtub-like curve, exhibiting 1) infant degradation, 2) steady degradation, 3) and accelerated degradation.

Xinfeng Zhang; Yang Rui; Zhang Tong; Xu Sichuan; Shen Yong; Ni Huaisheng

2014-01-01T23:59:59.000Z

492

Weak Localization in Bilayer Graphene  

Science Journals Connector (OSTI)

We have performed the first experimental investigation of quantum interference corrections to the conductivity of a bilayer graphene structure. A negative magnetoresistance—a signature of weak localization—is observed at different carrier densities, including the electroneutrality region. It is very different, however, from the weak localization in conventional two-dimensional systems. We show that it is controlled not only by the dephasing time, but also by different elastic processes that break the effective time-reversal symmetry and provide intervalley scattering.

R. V. Gorbachev; F. V. Tikhonenko; A. S. Mayorov; D. W. Horsell; A. K. Savchenko

2007-04-26T23:59:59.000Z

493

The Local Dimension of Energy  

E-Print Network (OSTI)

 and international experience, several bespoke energy strategies are identified  that have significant potential to contribute to local energy demand reduction and lower  CO2 emissions  in  the UK. The  strategies  identified  include, Combined Heat and Power  with  District  Heating  (CHP?DH),  Energy  from  Waste  Facilities  (Ef... . Monitoring and managing own energy and carbon emissions. Implementation of energy efficiency schemes within local government buildings such as schools, halls and sporting facilities etc. Using CHP (Combined Heat and Power) to supply heat and power...

Kelly, Scott

2011-01-31T23:59:59.000Z

494

Localized Magnetic States in Graphene  

Science Journals Connector (OSTI)

We examine the conditions necessary for the presence of localized magnetic moments on adatoms with inner shell electrons in graphene. We show that the low density of states at the Dirac point, and the anomalous broadening of the adatom electronic level, lead to the formation of magnetic moments for arbitrarily small local charging energy. As a result, we obtain an anomalous scaling of the boundary separating magnetic and nonmagnetic states. We show that, unlike any other material, the formation of magnetic moments can be controlled by an electric field effect.

Bruno Uchoa; Valeri N. Kotov; N. M. R. Peres; A. H. Castro Neto

2008-07-11T23:59:59.000Z

495

Thermodynamics of local causal horizons  

Science Journals Connector (OSTI)

We propose an expression for the entropy density associated with the local causal horizons in any diffeomorphism-invariant theory of gravity. If the black-hole entropy of the theory satisfies the physical process version of the first law of thermodynamics, then our proposed entropy satisfies the Clausius relation. Thus, our study shows that the thermodynamic nature of the spacetime horizons is not restricted to the black holes; it also applies to the local causal horizons in the neighborhood of any point in the spacetime.

Arif Mohd and Sudipta Sarkar

2013-07-16T23:59:59.000Z