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1

Magnesium behavior and structural defects in Mg+ ion implanted...  

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

Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a...

2

Mechanical Behavior of Indium Nanostructures  

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

Mechanical Behavior of Indium Nanostructures Mechanical Behavior of Indium Nanostructures Print Wednesday, 26 May 2010 00:00 Indium is a key material in lead-free solder...

3

Mechanical Behavior of Indium Nanostructures  

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

Mechanical Behavior of Indium Nanostructures Print Indium is a key material in lead-free solder applications for microelectronics due to its excellent wetting properties, extended...

4

Mechanical Behavior of Indium Nanostructures  

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

Mechanical Behavior of Indium Nanostructures Print Mechanical Behavior of Indium Nanostructures Print Indium is a key material in lead-free solder applications for microelectronics due to its excellent wetting properties, extended ductility, and high electrical conductivity. With the size of electronic devices continuing to shrink and the promise of indium-based nanotechnologies, it is important to develop a fundamental understanding of this material's small-scale mechanical properties and reliability. Researchers from the University of Waterloo, California Institute of Technology, and Los Alamos National Laboratory have collaborated with a team at ALS Beamline 12.3.2 to investigate the small-scale mechanics of indium nanostructures. Scanning x-ray microdiffraction (μSXRD) studies revealed that the indium microstructure is typical of a well-annealed metal, containing very few initial dislocations and showing close-to-theoretical strength.

5

Mechanical Behavior of Indium Nanostructures  

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

Mechanical Behavior of Indium Nanostructures Print Mechanical Behavior of Indium Nanostructures Print Indium is a key material in lead-free solder applications for microelectronics due to its excellent wetting properties, extended ductility, and high electrical conductivity. With the size of electronic devices continuing to shrink and the promise of indium-based nanotechnologies, it is important to develop a fundamental understanding of this material's small-scale mechanical properties and reliability. Researchers from the University of Waterloo, California Institute of Technology, and Los Alamos National Laboratory have collaborated with a team at ALS Beamline 12.3.2 to investigate the small-scale mechanics of indium nanostructures. Scanning x-ray microdiffraction (μSXRD) studies revealed that the indium microstructure is typical of a well-annealed metal, containing very few initial dislocations and showing close-to-theoretical strength.

6

Mechanical Behavior of Indium Nanostructures  

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

Mechanical Behavior of Indium Nanostructures Print Mechanical Behavior of Indium Nanostructures Print Indium is a key material in lead-free solder applications for microelectronics due to its excellent wetting properties, extended ductility, and high electrical conductivity. With the size of electronic devices continuing to shrink and the promise of indium-based nanotechnologies, it is important to develop a fundamental understanding of this material's small-scale mechanical properties and reliability. Researchers from the University of Waterloo, California Institute of Technology, and Los Alamos National Laboratory have collaborated with a team at ALS Beamline 12.3.2 to investigate the small-scale mechanics of indium nanostructures. Scanning x-ray microdiffraction (μSXRD) studies revealed that the indium microstructure is typical of a well-annealed metal, containing very few initial dislocations and showing close-to-theoretical strength.

7

Defect formation mechanism during PECVD of a-Si:H  

SciTech Connect

Defect formation mechanism in a-Si:H during PECVD at substrate temperature below 250 C is considered to be breaking of weak bonds in the Urbach tail. To break weak bonds, an extra energy is necessary. This energy is supplied by the reaction energy of SiH{sub 3} precursor at the growing surface incorporating SiH{sub 2} into the network. The defect density is experimentally shown to be proportional to a product of the energy supply frequency, i.e., SiH{sub 2} density, and the weak bond density which is obtained by the Urbach energy. By analysis using the configurational coordinate diagram the energy level of the broken weak bond is determined to be 0.2 eV above the valence band mobility edge. There is similarity of the defect formation mechanism during deposition to that of the Staebler-Wronski effect.

Maeda, Keiji; Umezu, Ikurou

1997-07-01T23:59:59.000Z

8

Influence of defects on thermal and mechanical properties of metals  

E-Print Network (OSTI)

of theories of melting with respect to defects. We studied the melting and freezing process for a model system of copper with and without defects. We studied point defects (1, 2, 4, 8 vacancies and 1, 2, 4, 8 interstitials), line defects (edge dislocation...

Kamani, Sandeep Kumar

2009-05-15T23:59:59.000Z

9

Defective Interfering Particles of Poliovirus IV. Mechanisms of Enrichment  

Science Journals Connector (OSTI)

...virus. 1424 J. VIROL. 3 DEFECTIVE INTERFERING PARTICLES OF POLIOVIRUS...experiments were originally car- ried out in an attempt to...input ratio of standard to defective particles as measured by the...and D. Baltimore. 1973. Defective interfering particles of poliovirus...

Charles N. Cole; David Baltimore

1973-12-01T23:59:59.000Z

10

Influence of oriented topological defects on the mechanical properties of carbon nanotube heterojunctions  

SciTech Connect

The mechanical properties of finite-length (5,0)/(8,0) single-walled carbon nanotube (SWCNT) heterojunctions with manipulated topological defects are investigated using molecular dynamics simulation calculations. The results show that the mechanical properties and deformation behavior of SWCNT heterojunctions are mainly affected not only by the diameter of the thinner segment of the SWCNT heterojunction but also by the orientation of the heptagon-heptagon (7-7) pair in the junction region. Moreover, the orientation of the 7-7 pair strongly affects those properties in the compression loading than those in tensile loading. Finally, it is found that the location of buckling deformation in the heterojunctions is dependent on the orientation of the 7-7 pair in the compression.

Lee, We-Jay [National Center for High-Performance Computing; Chang, Jee-Gong [National Center for High-Performance Computing; Yang, An-Cheng [National Center for High-Performance Computing; Wang, Yeng-Tseng [National Center for High-Performance Computing; Su, Wan-Sheng [National Center for High-Performance Computing; Wang, Cai-Zhuang [Ames Laboratory; Ho, Kai-Ming [Ames Laboratory

2013-10-10T23:59:59.000Z

11

Improving Cooling performance of the mechanical resonator with the two-level-system defects  

E-Print Network (OSTI)

We study cooling performance of a realistic mechanical resonator containing defects. The normal cooling method through an optomechanical system does not work efficiently due to those defects. We show by employing periodical $\\sigma_z$ pulses, we can eliminate the interaction between defects and their surrounded heat baths up to the first order of time. Compared with the cooling performance of no $\\sigma_z$ pulses case, much better cooling results are obtained. Moreover, this pulse sequence has an ability to improve the cooling performance of the resonator with different defects energy gaps and different defects damping rates.

Tian Chen; Xiang-Bin Wang

2014-06-03T23:59:59.000Z

12

Graphene for reducing bubble defects and enhancing mechanical properties of graphene/cellulose acetate composite films  

Science Journals Connector (OSTI)

In this study, we have demonstrated a strategy by which graphene was used to reduce the bubble defects and enhance the mechanical properties in graphene/cellulose acetate (Gr/CA) composite films. Mono- and multil...

Lei Liu; Zhigang Shen; Shuaishuai Liang; Min Yi

2014-01-01T23:59:59.000Z

13

Mechanical Behaviors of Alloys From First Principles  

E-Print Network (OSTI)

Some Backgrounds on The Quantum Mechanical Stresses . . .3.2.2 The Quantum Mechanical Stresses and The Generalized3.2.3 Quantum-Mechanical

Hanlumyuang, Yuranan

2011-01-01T23:59:59.000Z

14

Characterization of Thermo-Mechanical Behaviors of Advanced High...  

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

"Mega" Merit Review 2008 on February 25, 2008 in Bethesda, Maryland. merit08smith7.pdf More Documents & Publications Characterization of Thermo-Mechanical Behaviors of...

15

Characterization of Thermo-Mechanical Behaviors of Advanced High...  

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

of Thermo-Mechanical Behaviors of Advanced High Strength Steels (AHSS) Presenter: Mark Smith Principal Investigator: Xin Sun Pacific Northwest National Laboratory Principal...

16

Grain boundary defects initiation at the outer surface of dissimilar welds: Corrosion mechanism studies  

SciTech Connect

Dissimilar welds located on the primary coolant system of the French PWR plants exhibit grain boundary defects in the true austenitic zones of the first buttering layer. If grain boundaries reach the interface, they can extend to the martensitic band. Those defects are filled with compact oxides. In addition, the ferritic base metal presents some pits along the interface. Nowadays, three mechanisms are proposed to explain the initiation of those defects: stress corrosion cracking, intergranular corrosion and high temperature intergranular oxidation. This paper is dealing with the study of the mechanisms involved in the corrosion phenomenon. Intergranular corrosion tests performed on different materials show that only the first buttering layer, even with some {delta} ferrite, is sensitized. The results of stress corrosion cracking tests in water solutions show that intergranular cracking is possible on a bulk material representative of the first buttering layer. It is unlikely on actual dissimilar welds where the ferritic base metal protects the first austenitic layer by galvanic coupling. Therefore, the stress corrosion cracking assumption cannot explain the initiation of the defects in aqueous environment. The results of the investigations and of the corrosion studies led to the conclusion that the atmosphere could be the only possible aggressive environment. This conclusion is based on natural atmospheric exposure and accelerated corrosion tests carried out with SO{sub 2} additions in controlled atmosphere. They both induce a severe intergranular corrosion on true sensitized austenitic materials.

Bouvier, O. De; Yrieix, B. [Electricite De France, Moret Sur Loing (France). Research and Development Division

1995-12-31T23:59:59.000Z

17

Nonradiative coherent carrier captures and defect reaction at deep-level defects via phonon-kick mechanism  

SciTech Connect

We simulated the time evolution of electron-lattice coupling mode, and a series of nonradiative carrier captures by a deep-level defect in a semiconductor. For lattice relaxation energy of the order of the band gap, a series of coherent (athermal) electron and hole captures by a defect is possible for high carrier densities, which results in an inflation in the induced lattice vibration, which in turn enhances a defect reaction.

Wakita, Masaki; Suzuki, Kei; Shinozuka, Yuzo [Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan)

2014-02-21T23:59:59.000Z

18

Mechanical behavior of dip-brazed aluminum sandwich panels  

E-Print Network (OSTI)

An experimental study was carried out to determine the mechanical behavior of sandwich panels containing cellular cores of varying shape. Compression and four point bend tests were performed on sandwich panels with square ...

Hohmann, Brian P. (Brian Patrick)

2007-01-01T23:59:59.000Z

19

Characterization of Thermo-Mechanical Behaviors of Advanced High...  

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

Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. lm25smith.pdf More Documents & Publications Characterization of Thermo-Mechanical Behaviors of...

20

Fundamentals of mechanical behavior in structural intermetallics: A synthesis of atomistic and continuum modeling  

SciTech Connect

After a brief account of the recent advances in computational research on mechanical behavior of structural intermetallics, currently unresolved problems and critical issues are addressed and the knowledge base for potential answers to these problems is discussed. As large-scale problems (e.g., dislocation core structures, grain boundaries, and crack tips) are treated by atomistic simulations, future development of relevant interatomic potentials should be made consistent with the results of first-principles calculations. The bulk and defect properties calculated for intermetallic compounds, both known and as yet untested, can furnish insights to alloy designers in search of new high-temperature structural intermetallics.

Yoo, M.H.; Fu, C.L.

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Graphene flakes with defective edge terminations: Universal and topological aspects, and one-dimensional quantum behavior  

E-Print Network (OSTI)

Systematic tight-binding investigations of the electronic spectra (as a function of the magnetic field) are presented for trigonal graphene nanoflakes with reconstructed zigzag edges, where a succession of pentagons and heptagons, that is 5-7 defects, replaces the hexagons at the zigzag edge. For nanoflakes with such reczag defective edges, emphasis is placed on topological aspects and connections underlying the patterns dominating these spectra. The electronic spectra of trigonal graphene nanoflakes with reczag edge terminations exhibit certain unique features, in addition to those that are well known to appear for graphene dots with zigzag edge termination. These unique features include breaking of the particle-hole symmetry, and they are associated with nonlinear dispersion of the energy as a function of momentum, which may be interpreted as nonrelativistic behavior. The general topological features shared with the zigzag flakes include the appearance of energy gaps at zero and low magnetic fields due to finite size, the formation of relativistic Landau levels at high magnetic fields, and the presence between the Landau levels of edge states (the socalled Halperin states) associated with the integer quantum Hall effect. Topological regimes, unique to the reczag nanoflakes, appear within a stripe of negative energies E_b < E < 0, and along a separate feature forming a constant-energy line outside this stripe. The lower bound (E_b) specifying the energy stripe is independent of size. A main finding concerns the limited applicability of the continuous Dirac-Weyl equation, since the latter does not reproduce the special reczag features. (See also the extended abstract in the paper.)

Igor Romanovsky; Constantine Yannouleas; Uzi Landman

2012-10-17T23:59:59.000Z

22

Identifying causes of mechanical defects and critical control points in fruit supply chains: an overview of a banana supply chain  

Science Journals Connector (OSTI)

The issue of food losses is of high importance in the efforts to combat hunger, raise income and improve food security in many developing countries. Therefore, there is need to minimise food losses in agri-food supply chains. This study was conducted with the aim to identify causes of mechanical defects in banana fruit supply chain in Zimbabwe and to also establish critical control points at which incidence of the mechanical fruit defects can be minimised in the chain. Data was gathered through interviews and participatory observation. Most of the causes of mechanical defects were found to be due to poor handling at the different stages in the chain. Propping, maturity at harvest, handling during harvesting and packing, and control of temperature and relative humidity during fruit ripening were established as critical control points at which incidence of mechanical damage can be minimised.

Lesley Macheka; Ruth Tambudzai Ngadze; Faith Angeline Manditsera; Juliet Mubaiwa; Robert Musundire

2013-01-01T23:59:59.000Z

23

Mechanics of Insulator Behavior in Concrete Crosstie Fastening Systems  

E-Print Network (OSTI)

gauge · Protect shoulder and attenuate load entering shoulder · Provide electrical isolation betweenMechanics of Insulator Behavior in Concrete Crosstie Fastening Systems Joint Rail Conference and causes · Relevant material properties related to failure modes · Preliminary testing and results · Future

Barkan, Christopher P.L.

24

Experimental characterization of mechanical vibrations and acoustical noise generated by defective automotive wheel hub bearings  

Science Journals Connector (OSTI)

Wheel hub bearing faults in passenger cars cause chattering at the corresponding wheel, increase chassis vibration and generate high noise levels inside the car cabin. In this paper a series of in-situ test with defective and healthy wheel hub bearings were conducted. Mechanical vibrations and sound were measured and data were analyzed with a number of signal processing methods in frequency and time-frequency domains. Additionally, a statistical signal processing method was also performed. The results of the various methods are compared and it was found that most of the methods used in this work are well suited for the analysis. Some methods, however, show certain limitations with respect to their informative value and their ability of implementation.

Eduardo Rubio; Juan C. Juregui

2012-01-01T23:59:59.000Z

25

Graphene flakes with defective edge terminations: Universal and topological aspects, and one-dimensional quantum behavior  

E-Print Network (OSTI)

Graphene flakes with defective edge terminations: Universal and topological aspects, and one graphene nanoflakes with reconstructed zigzag edges, where a succes- sion of pentagons and heptagons these spectra. The electronic spectra of trigonal graphene nanoflakes with reczag edge terminations exhibit

Yannouleas, Constantine

26

Cryogenic Mechanical Behavior of Poly(trimethylene terephthalate)  

Science Journals Connector (OSTI)

Cryogenic Mechanical Behavior of Poly(trimethylene terephthalate) ... (3) Though tensile strength and Youngs modulus usually increase as temperature is decreased, at cryogenic temperaturesthat is, temperatures like those of liquid nitrogen (75 K) and liquid helium (4 K)most polymers, even elastomers, become so brittle and fragile that they can be elongated no more than 3% before breaking. ... (4) This would mean that all polymers would be glassy because the high elasticity based on entropy elasticity is diminished at cryogenic temperatures, which tends to limit the usage of polymeric materials. ...

Takashi Nishino; Taiichi Okamoto; Hiroshi Sakurai

2011-03-04T23:59:59.000Z

27

Influence of addition of nanoclay on the mechanical behavior of polymer nanocomposite  

Science Journals Connector (OSTI)

The mechanical behavior of polymer nanocomposites, which containing epoxy resin as matrix and carbon fiber, glass fiber, nanoclay as reinforcements have been studied. The composites ... Electron Microscope (SEM) ...

T. Sakthivel; S. Balasivanandha Prabu

2008-04-01T23:59:59.000Z

28

Determination of Electrochemical Performance and Thermo-Mechanical-Chemical Stability of SOFCs from Defect Modeling  

SciTech Connect

This research was focused on two distinct but related issues. The first issue concerned using defect modeling to understand the relationship between point defect concentration and the electrochemical, thermo-chemical and mechano-chemical properties of typical solid oxide fuel cell (SOFC) materials. The second concerned developing relationships between the microstructural features of SOFC materials and their electrochemical performance. To understand the role point defects play in ceramics, a coherent analytical framework was used to develop expressions for the dependence of thermal expansion and elastic modulus on point defect concentration in ceramics. These models, collectively termed the continuum-level electrochemical model (CLEM), were validated through fits to experimental data from electrical conductivity, I-V characteristics, elastic modulus and thermo-chemical expansion experiments for (nominally pure) ceria, gadolinia-doped ceria (GDC) and yttria-stabilized zirconia (YSZ) with consistently good fits. The same values for the material constants were used in all of the fits, further validating our approach. As predicted by the continuum-level electrochemical model, the results reveal that the concentration of defects has a significant effect on the physical properties of ceramic materials and related devices. Specifically, for pure ceria and GDC, the elastic modulus decreased while the chemical expansion increased considerably in low partial pressures of oxygen. Conversely, the physical properties of YSZ remained insensitive to changes in oxygen partial pressure within the studied range. Again, the findings concurred exactly with the predictions of our analytical model. Indeed, further analysis of the results suggests that an increase in the point defect content weakens the attractive forces between atoms in fluorite-structured oxides. The reduction treatment effects on the flexural strength and the fracture toughness of pure ceria were also evaluated at room temperature. The results reveal that the flexural strength decreases significantly after heat treatment in very low oxygen partial pressure environments; however, in contrast, fracture toughness is increased by 30-40% when the oxygen partial pressure was decreased to 10{sup -20} to 10{sup -22} atm range. Fractographic studies show that microcracks developed at 800 oC upon hydrogen reduction are responsible for the decreased strength. To understand the role of microstructure on electrochemical performance, electrical impedance spectra from symmetric LSM/YSZ/LSM cells was de-convoluted to obtain the key electrochemical components of electrode performance, namely charge transfer resistance, surface diffusion of reactive species and bulk gas diffusion through the electrode pores. These properties were then related to microstructural features, such as triple-phase boundary length and tortuosity. From these experiments we found that the impedance due to oxygen adsorption obeys a power law with pore surface area, while the impedance due to charge transfer is found to obey a power-law with respect to triple phase boundary length. A model based on kinetic theory explaining the power-law relationships observed was then developed. Finally, during our EIS work on the symmetric LSM/YSZ/LSM cells a technique was developed to improve the quality of high-frequency impedance data and their subsequent de-convolution.

Eric Wachsman; Keith L. Duncan

2006-09-30T23:59:59.000Z

29

SISGR Domain Microstructures and Mechanisms for Large, Reversible and Anhysteretic Strain Behaviors in Phase Transforming Ferroelectric Materials  

SciTech Connect

This four-year project (including one-year no-cost extension) aimed to advance fundamental understanding of field-induced strain behaviors of phase transforming ferroelectrics. We performed meso-scale phase field modeling and computer simulation to study domain evolutions, mechanisms and engineering techniques, and developed computational techniques for nanodomain diffraction analysis; to further support above originally planned tasks, we also carried out preliminary first-principles density functional theory calculations of point defects and domain walls to complement meso-scale computations as well as performed in-situ high-energy synchrotron X-ray single crystal diffraction experiments to guide theoretical development (both without extra cost to the project thanks to XSEDE supercomputers and DOE user facility Advanced Photon Source).

Wang, Yu

2013-12-06T23:59:59.000Z

30

A Model for the Nonlinear Mechanical Behavior of Asphalt Binders and its Application in Prediction of Rutting Susceptibility  

E-Print Network (OSTI)

The mechanical behavior of asphalt binders is nonlinear. The binders exhibit shear thinning/thickening behavior in steady shear tests and non-proportational behavior in other standard viscoelastic tests such as creep-recovery or stress relaxation...

Srinivasa Parthasarathy, Atul

2013-04-30T23:59:59.000Z

31

Characterization of thermo-mechanical and long-term behaviors of multi-layered composite materials  

E-Print Network (OSTI)

This study presents characterization of thermo-mechanical viscoelastic and long-term behaviors of thick-section multi-layered fiber reinforced polymer composite materials. The studied multi-layered systems belong to a class of thermo...

Nair, Aravind R.

2009-06-02T23:59:59.000Z

32

Texas Heart Institute Journal Mechanical Behavior of Coronary Stents 491 2011 by the Texas Heart  

E-Print Network (OSTI)

Texas Heart Institute Journal Mechanical Behavior of Coronary Stents 491 © 2011 by the Texas Heart in the clinical setting. (Tex Heart Inst J 2011;38(5):491-501) E ndovascular stents are expandable meshes

Canic, Suncica

33

An Atomistic Study of the Mechanical Behavior of Carbon Nanotubes and Nanocomposite Interfaces  

E-Print Network (OSTI)

The research presented in this dissertation pertains to the evaluation of stiffness of carbon nanotubes (CNTs) in a multiscale framework and modeling of the interfacial mechanical behavior in CNT-polymer nanocomposites. The goal is to study...

Awasthi, Amnaya P.

2011-02-22T23:59:59.000Z

34

Mechanical behavior of closed-cell and hollow-sphere metallic foams  

E-Print Network (OSTI)

(cont.) The elastic anisotropy and yield surfaces are fully characterized, and numerical equations are developed to allow the simple evaluation of the effect of geometric and material properties on the mechanical behavior ...

Sanders, Wynn Steven, 1974-

2002-01-01T23:59:59.000Z

35

Effect of nanofiber proximity on the mechanical behavior of high volume fraction aligned carbon nanotube arrays  

E-Print Network (OSTI)

The effect of nanofiber proximity on the mechanical behavior of nanofiber arrays with volume fractions (V f) from 1% to 20% was quantified via nanoindentation of an aligned carbon nanotube (A-CNT) array. The experimental ...

Cebeci, Hlya

36

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

37

Mechanical Behavior Studies of Depleted Uranium in the Presence of Hydrides  

SciTech Connect

This project addresses critical issues related to aging in the presence of hydrides (UH{sub 3}) in DU and the subsequent effect on mechanical behavior. Rolled DU specimens with three different hydrogen concentrations and the as-rolled condition were studied. The texture measurements indicate that the hydrogen charging is affecting the initial as-rolled DU microstructure/texture. The macroscopic mechanical behavior suggests the existence of a threshold between the 0 wpmm H and 0.3 wppm H conditions. A VPSC simulation of the macroscopic strain-stress behavior, when taking into account only a texture effect, shows no agreement with the experiment. This suggests that the macroscopic mechanical behavior observed is indeed due to the presence of hydrogen/hydrides in the DU bulk. From the lattice strain variation it can be concluded that the hydrogen is affecting the magnitude and/or the nature of CRSS. The metallography indicates the specimens that underwent the hydrogen charging process, developed large grains and twinning, which were enhanced by the presence of hydrogen. Further studies using electron microscopy and modeling will be conducted to learn about the deformation mechanisms responsible for the observed behavior.

Garlea, E.; Morrell, J. S.; Bridges, R. L.; Powell, G. L.; Brown, d. W.; Sisneros, T. A.; Tome, C. N.; Vogel, S. C.

2011-02-14T23:59:59.000Z

38

Atomic-Level Computer Simulation of SiC: Defect Accumulation...  

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

Atomic-Level Computer Simulation of SiC: Defect Accumulation, Mechanical Properties and Defect Recovery. Atomic-Level Computer Simulation of SiC: Defect Accumulation, Mechanical...

39

MODEL OF MECHANISM BEHAVIOR FOR VERIFICATION OF PLC Jos M. Machado  

E-Print Network (OSTI)

MODEL OF MECHANISM BEHAVIOR FOR VERIFICATION OF PLC PROGRAMS José M. Machado University of Minho on formal methods is now available for checking PLC (Programmable Logic Controller) programs. To verify a PLC program, it is necessary to consider a set of properties to prove and one of the most interesting

Paris-Sud XI, Université de

40

Electric signaling behavior and the mechanisms of electric organ discharge production in mormyrid fish  

E-Print Network (OSTI)

, the sequence of pulse intervals (SPI) is variable and plays more of a role in signaling behavioral states, and therefore drive the generation of SPI patterns. Current studies are addressing the mechanisms underlying in the electrosensory system of gymnotiform fish for determining the frequency difference between a fish's own electric

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Ab Initio Study of Topological Defects in Single Walled Carbon Nanotubes and their Effect on Gas Sensing Mechanism  

SciTech Connect

We have studied the energetics and charge tranfer of the (10,0) and (6,6) single walled carbon nanotubes with various defects such as monovacancy and Stone-Wales defect and their interaction with the Hydrogen Sulphide gas molecule using Ab Initio based computational method to design Single Walled Carbon Nanotube based gas sensor . We have also investigated the effect of Gold doping in Carbon Nanotubes on the adsorption of Hydrogen Sulphide gas molecule. We demonstrate that the adsorption energy as well as charge transfer is affected by the introduction of defects at the surface of the CNTs resulting in improved sensitivity for the Hydrogen Sulphide gas molecules compared to the pristine CNT.

Srirangarajan, Aarti [Nanoelectronics Lab, MIMOS BHD., KL, 57000 (Malaysia); Kahaly, Mousumi Upadhyay [DSM/IRAMIS/SPCSI, CEA Saclay, 91191 (France)

2011-05-25T23:59:59.000Z

42

Experimental investigation of the effect of temperature on the mechanical behavior of Tournemire shale  

Science Journals Connector (OSTI)

Abstract This paper is devoted to the experimental investigation of the effect of temperature on the mechanical behavior of a typical anisotropic clayey rock, the Tournemire shale. Hydrostatic and conventional triaxial compression tests are first performed under room temperature for two principal loading orientations, respectively parallel and perpendicular to the bedding planes. The obtained results confirm an anisotropic mechanical behavior observed by the previous works. Further, hydrostatic and triaxial compression tests with different confining pressures are carried out under different temperatures up to 250C. With the increase of temperature, there is a significant decrease of Young?s modulus and the compression failure strength but an increase of the overall deformability of material. The temperature change also affects the anisotropic response related to the deformation of bedding planes.

M. Masri; M. Sibai; J.F. Shao; M. Mainguy

2014-01-01T23:59:59.000Z

43

Defect Scattering in Graphene  

Science Journals Connector (OSTI)

Irradiation of graphene on SiO2 by 500eV Ne and He ions creates defects that cause intervalley scattering as is evident from a significant Raman D band intensity. The defect scattering gives a conductivity proportional to charge carrier density, with mobility decreasing as the inverse of the ion dose. The mobility decrease is 4 times larger than for a similar concentration of singly charged impurities. The minimum conductivity decreases proportional to the mobility to values lower than 4e2/?h, the minimum theoretical value for graphene free of intervalley scattering. Defected graphene shows a diverging resistivity at low temperature, indicating insulating behavior. The results are best explained by ion-induced formation of lattice defects that result in midgap states.

Jian-Hao Chen; W. G. Cullen; C. Jang; M. S. Fuhrer; E. D. Williams

2009-06-12T23:59:59.000Z

44

An experimental investigation into the stress-dependent mechanical behavior of cohesive soil with application to wellbore instability  

E-Print Network (OSTI)

This thesis investigates the mechanical behavior of cohesive soils with reference to the applications of wellbore instabilities through an extensive program of laboratory element and model borehole tests. The laboratory ...

Abdulhadi, Naeem Omar

2009-01-01T23:59:59.000Z

45

Dilatation-strain analysis of the effects of flaws on the mechanical behavior of a highly filled elastomer  

E-Print Network (OSTI)

DILATATION-STRAIN ANALYSIS OF THE EFFECTS OF FLANS ON THE MECHANICAL BEHAVIOR OF A HIGHLY FILLED ELASTOMER A Thesis By BENJAMIN RAY SMITH Submitted to the Graduate College of the Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1966 Major Subject. 'Aerospace Engineering DILATATION-STRAIN ANALYSIS OF THE EFFECTS OF FLAWS ON THE MECHANICAL BEHAVIOR OF A HIGHLY FILLED ELASTOMER A Thesis By BENJAMIN RAY SMITH Approved...

Smith, Benjamin Ray

2012-06-07T23:59:59.000Z

46

Effect of halloysite nanoclay on mechanical properties, thermal behavior and microstructure of cement mortars  

Science Journals Connector (OSTI)

Abstract Many studies have targeted the application of clay in cement composites and declared some enhancement on the properties of concrete. However there is little knowledge on nanoclays and their effect on the mechanical properties and durability of cement composites. Halloysite nanoclay is one of the subcategories of nanoclay that has been undeservedly ignored in the production of cement composites. Chemically, the outer surface of the halloysite nanotubes has properties similar to SiO2 while the inner cylinder core is related to Al2O3 which together may improve the cement matrix. In this study the mechanical properties, flowability, thermal behavior and durability of mortars containing 1, 2, 3% halloysite nanoclay were studied. Compressive strength and gas permeability of samples with 3% and 2% nanoclay were improved up to 24% and 56%, respectively. SEM, XRD, DSC tests were carried out to investigate the microstructure and chemical composition change in samples with halloysite nanoclay.

Nima Farzadnia; Abang Abdullah Abang Ali; Ramazan Demirboga; Mohammed Parvez Anwar

2013-01-01T23:59:59.000Z

47

Structure and Mechanical Behavior of Elastomeric Multiblock Terpolymers Containing Glassy, Rubbery, and Semicrystalline Blocks  

SciTech Connect

Multiblock copolymers containing glassy poly(cyclohexylethylene) (C), rubbery poly(ethylene-alt-propylene) (P), and semicrystalline poly(ethylene) (E) were synthesized by sequential anionic polymerization of styrene, isoprene, and butadiene followed by catalytic hydrogenation. The resulting CECPCEC (denoted XPX) and CECP (XP) multiblock copolymers each contain 50 vol % of P and equal amounts of C and E. These materials have been studied by dynamic mechanical spectroscopy (DMS), transmission electron microscopy (TEM), small- and wide-angle X-ray scattering (SAXS and WAXS), differential scanning calorimetry (DSC), and tensile deformation to characterize the morphology, phase behavior, and mechanical properties. Microphase separation in these compounds is induced by crystallization of E and/or chemical incompatibility between the three blocks, leading to a new type of morphology which contains continuous region of P and continuous region of microphase-separated X, resulting in mechanically resilient materials. High molecular weight block copolymers microphase separate with two different length scales associated with segregation between C and E and X and P. These structural features produce a nonclassical scaling relationship for the C-E domain spacing, d {approx} N{sup 0.31}, where N is the degree of polymerization of CEC portion. The role of semicrystalline E domains during uniaxial deformation has been exposed with WAXS experiments, which support a two-step mechanism involving recoverable and nonrecoverable deformation to different extents. Strain hardening is observed in double-anchored XPX, but not in single-anchored XP, at large tensile strains.

Zuo, Feng; Alfonzo, C. Guillermo; Bates, Frank S. (UMM)

2012-11-14T23:59:59.000Z

48

Thermal-mechanical fatigue behavior of nickel-base superalloys. Final Report  

SciTech Connect

The main achievements of a 36-month research program are presented. The main objective was to gain more insight into the problem of crack growth under thermal mechanical fatigue (TMF) conditions. This program was conducted at M.I.T. for the period of September 1982 to September 1985. The program was arranged into five technical tasks. Under Task I, the literature of TMF data was reviewed. The goal was to identify the crack propagation conditions in aircraft engines (hot section) and to assess the validity of conventional fracture mechanics parameters to address TMF crack growth. The second task defined the test facilities, test specimen and the testing conditions needed to establish the effectiveness of data correlation parameters identified in Task I. Three materials (Inconel X-750, Hastelloy-X, and B-1900) were chosen for the program. Task II was accomplished in collaboration with Pratt and Whitney Aircraft engineers. Under Task III, a computerized testing system to measure the TMF behavior (LCF and CG behaviors) of various alloys systems was built. The software used to run isothermal and TMF tests was also developed. Built around a conventional servohydraulic machine, the system is capable of push-pull tests under stress or strain and temperature controlled conditions in the temperature range of 25C to 1050C. A crack propagation test program was defined and conducted under Task IV. The test variables included strain range, strain rate (frequency) and temperature. Task V correlated and generalized the Task IV data for isothermal and variable temperature conditions so that several crack propagation parameters could be compared and evaluated. The structural damage (mode of cracking and dislocation substructure) under TMF cycling was identified and contrasted with the isothermal damage to achieve a sound fundamental mechanistic understanding of TMF.

Pelloux, R.M.; Marchand, N.

1986-03-01T23:59:59.000Z

49

Effects of Stone-Wales and vacancy defects in atomic-scale friction on defective graphite  

SciTech Connect

Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite.

Sun, Xiao-Yu [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China); Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Wu, RunNi; Xia, Re [Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Chu, Xi-Hua; Xu, Yuan-Jie, E-mail: yj-xu@whu.edu.cn [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China)

2014-05-05T23:59:59.000Z

50

ADSORPTION MECHANISMS AND TRANSPORT BEHAVIOR BETWEEN SELENATE AND SELENITE ON DIFFERENT SORBENTS  

SciTech Connect

Adsorption of different oxidation species of selenium (Se), selenate (SeO42-) and selenite (SeO32-), with varying pHs (2 - 10) and ionic strengths (I = 0.01 M, 0.1 M and 1.0 M NaNO3) was measured on quartz, aluminum oxide, and synthetic iron oxide (ferrihydrite) using batch reactors to obtain a more detailed understanding of the adsorption mechanisms (e.g., inner- and outer-sphere complex). In addition to the batch experiments with single minerals contained in native Hanford Site sediment, additional batch adsorption studies were conducted with native Hanford Site sediment and groundwater as a function of 1) total Se concentration (from 0.01 to 10 mg L-1) and 2) soil to solution ratios (1:20 and 1:2 grams per mL). Results from these batch studies were compared to a set of saturated column experiments that were conducted with natural Hanford sediment and groundwater spiked with either selenite or selenate to observe the transport behavior of these species. Both batch and column results indicated that selenite adsorption was consistently higher than that of selenate in all experimental conditions used. These different adsorption mechanisms between selenite and selenate result in the varying mobility of Se in the subsurface environment and explain the dependence on the oxidation species.

Snyder, Michelle MV; Um, Wooyong

2014-04-30T23:59:59.000Z

51

Materials Science and Engineering A261 (1999) 4452 Mo5Si3 single crystals: physical properties and mechanical behavior  

E-Print Network (OSTI)

. Among these phases, refractory metal silicides appear to be more attractive because of their ultra-high melting temperatures [1]. Among the refractory metal silicides, the silicides in the Mo­Si system show processing, physical properties and mechanical behavior of an ultrahigh temperature structural silicide, Mo5

52

Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors  

SciTech Connect

The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

Simon Phillpot; James Tulenko

2011-09-08T23:59:59.000Z

53

Mo{sub 5}Si{sub 3} single crystals: Physical properties and mechanical behavior  

SciTech Connect

The materials processing, physical properties and mechanical behavior of an ultra-high temperature structural silicide, Mo{sub 5}Si{sub 3}, have been studied. High purity single crystals of Mo{sub 5}Si{sub 3} have been synthesized by both optical floating zone and Czochralski methods. The thermal and elastic properties of the MO{sub 5}Si{sub 3} single crystals were experimentally measured. Results show that Mo{sub 5}Si{sub 3} has significant thermal expansion anisotropy along the a and c directions with {alpha}{sub c}/{alpha}{sub a} = 2.2. Single crystal elastic moduli of Mo{sub 5}Si{sub 3} indicate that it has less elastic anisotropy and lower shear moduli than transition metal disilicides. Tensile stresses of up to 1.8 GPa can develop at grain boundaries after cooling from the melting point due to the thermal expansion mismatch in Mo{sub 5}Si{sub 3}, causing grain boundary cracking during processing of polycrystals. Room temperature Vickers indentation tests on (100) and (001) planes have been performed with different indenter diagonal orientations. The orientation dependence of hardness and fracture toughness of Mo{sub 5}Si{sub 3} single crystals have been obtained. The corresponding deformation and fracture modes have been revealed by microscopy studies. A comparison of Mo{sub 5}Si{sub 3} with other high temperature structural silicides, e.g., C11{sub b} and C40 transition metal disilicides, is discussed.

Chu, F.; Thoma, D.J.; McClellan, K.J.; Peralta, P.

1998-12-01T23:59:59.000Z

54

Mechanisms of behavioral choice in the nervous system of the medicinal leech  

E-Print Network (OSTI)

Single Neurone. J Exp Biol 77:71- Wiersma CA, Ikeda K (1964)to each behavior (Wiersma and Ikeda, 1964; Kupfermann and

Gaudry, Quentin

2008-01-01T23:59:59.000Z

55

The energy coupling efficiency of multi-wavelength laser pulses to damage initiating defects in DKDP nonlinear crystals  

SciTech Connect

The bulk damage performance of potassium dihydrogen phosphate crystals under simultaneous exposure to 1064-, 532-, and 355-nm nanosecond-laser pulses is investigated in order to probe the laser-induced defect reactions leading to damage initiation during frequency conversion. The results provide insight into the mechanisms governing the behavior of the damage initiating defects under exposure to high power laser light. In addition, it is suggested that the damage performance can be directly related to and predicted from the damage behavior of the crystal at each wavelength separately.

DeMange, P; Negres, R A; Rubenchik, A M; Radousky, H B; Feit, M D; Demos, S G

2007-09-25T23:59:59.000Z

56

Mechanical Properties, sliding wear and solid particle erosion behaviors of plasma enhanced magnetron sputtering CrSiCN coating Systems  

Science Journals Connector (OSTI)

Abstract CrSiCN coating systems with different concentrations of Cr, Si, C, and N were investigated for their microstructure, mechanical properties (hardness H, elastic modulus E and indentation fracture toughness KIC) and tribological behaviors using SEM, nano-indentation, indentation, pin-on-disk wear test, and sand particle erosion test. The wear behaviors, such as specific wear rate and Archard wear coefficient, showed inverse relationships with H3/E2 ratio, confirming that the resistance to plastic deformation is the essential factor governing sliding wear behavior. High H3/E2 ratios also contributed to increased resistances to erosion at low impingement angles. However, at higher impingement angles (>60), coatings with lower index of brittleness (B=2.656m?1/2), higher critical load (P?=6.670N) for crack initiation and fracture surface energy (?f=0.123 Jm?2) offered a higher erosion resistance. The indentation fracture toughness (KIC), hardness (H) and elastic modulus (E) are limited to interpret erosion behaviors in a comprehensive approach, suggesting that erosion is a complex process where multiple mechanical properties contribute to erosion performance.

Feng Cai; Xiao Huang; Qi Yang

2014-01-01T23:59:59.000Z

57

Discrete particle transport in porous media : discrete observations of physical mechanisms influencing particle behavior  

E-Print Network (OSTI)

An understanding of how discrete particles in the micron to submicron range behave in porous media is important to a number of environmental problems. Discrete particle behavior in the interior of a porous medium is complex ...

Yoon, Joon Sik, 1973-

2005-01-01T23:59:59.000Z

58

Mechanical behavior of shape memory fibers spun from nanoclay-tethered polyurethanes  

Science Journals Connector (OSTI)

This study examined the effect of nanoclays on the shape memory behavior of polyurethane (PU) in fibrous form. A cation was introduced into the PU molecules to disperse the organo-nanoclay (MMT) into poly(?- capr...

Seok Jin Hong; Woong-Ryeol Yu; Ji Ho Youk

2008-10-01T23:59:59.000Z

59

Microstructure-based Computational Modeling of the Mechanical Behavior of Polymer Micro/Nano-composites  

E-Print Network (OSTI)

. .......................................... 150 Fig. 5.2. Variation of non-linear viscoelastic parameters versus stress levels at 296 K. ............................................................................................................ 152 Fig. 5.3. Predictions for PMMA behavior...) strain and (b) time for creep tests in the range of 63 to 71.5 MPa at 323 K. ................................................................ 163 Fig. 5.10. Forecasting the behavior of PMMA under high stress levels for finding the stress where rupture...

Heydarkhan Tehrani, Ardeshir

2013-08-26T23:59:59.000Z

60

3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods  

SciTech Connect

The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of the full fuel rod to include local defects. A 3D thermo-mechanical model is used to simulate the global fuel rod behavior, and includes effects on the thermal and mechanical behavior of the fuel due to accumulation of fission products, fission gas production and release, and the effects of fission gas accumulation on thermal conductivity across the fuel-clad gap. Local defects can be modeled simply by including them in the 3D fuel rod model, without the need for mapping between two separate models. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the local defect to be coupled with the global fuel rod model. This approach for modeling fuel with MPS defects is demonstrated and compared with alternative techniques. The effects of varying parameters of the MPS defect are studied using this technique and presented here.

B.W. Spencer; J.D. Hales; S.R. Novascone; R.L. Williamson

2012-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Atmospheric pressure plasma jet: Effect of electrode configuration, discharge behavior, and its formation mechanism  

E-Print Network (OSTI)

Atmospheric pressure plasma jet: Effect of electrode configuration, discharge behavior, and its 2008; accepted 8 June 2009; published online 10 July 2009 Atmospheric pressure plasma jet APPJ can The atmospheric pressure plasma is much advantageous over low pressure plasmas in various aspects. It can be dis

Zexian, Cao

62

Vehicle Technologies Office Merit Review 2014: Coupling of Mechanical Behavior of Cell Components to Electrochemical-Thermal Models for Computer-Aided Engineering of Batteries under Abuse  

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

Presentation given by NREL at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about coupling of mechanical behavior of cell...

63

Mechanical Behavior of Diamond-Sawn Multi-Crystalline Silicon Wafers and its Improvement  

Science Journals Connector (OSTI)

Poor mechanical property is identified as a potential barrier to commercial development of diamond wire sawn multi-crystalline silicon wafers. 3-point bending tests of the diamond-sawn multi-crystalline silico...

Hongchen Meng; Lang Zhou

2014-04-01T23:59:59.000Z

64

Production, Characterization, and Mechanical Behavior of Cementitious Materials Incorporating Carbon Nanofibers  

E-Print Network (OSTI)

Carbon nanotubes (CNTs) and carbon nanofirbers (CNFs) have excellent properties (mechanical, electrical, magnetic, etc.), which can make them effective nanoreinforcements for improving the properties of materials. The incorporation of CNT/Fs in a...

Yazdanbakhsh, Ardavan

2012-10-19T23:59:59.000Z

65

The Mechanical Thermal and Microstructural Behaviors of the Strip Silicates Reinforced Epoxy-based Nanocomposites.  

E-Print Network (OSTI)

??Ten different sets of epoxy samples with compositions from 0wt% to 8wt% nanoclay were prepared by mechanical stirring and then casting to mold dog-bone shape (more)

Ho, Man Wai

2006-01-01T23:59:59.000Z

66

Microstructure and mechanical behavior of ultrafine-grained titanium J. Gubicza1,a  

E-Print Network (OSTI)

. The microstructure was characterized quantitatively by X-ray diffraction line profile analysis and transmission-ray diffraction line profile analysis and transmission electron microscopy (TEM). The ECAP was conducted at 400 electron microscopy after each step of deformation. The effect of procesing routes on the mechanical

Gubicza, Jenõ

67

Shedding Light on Nanocrystal Defects  

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

Shedding Light on Nanocrystal Defects Print Shedding Light on Nanocrystal Defects Print Nanocrystals have been the focus of much scientific interest lately, given their various advantageous mechanical properties. Their resistance to stress has had researchers proposing nanocrystals as a promising new protective coating for advanced gas turbine and jet engines. But recent studies conducted at the ALS show that the tiny size of nanocrystals does not safeguard them from defects. Engineering Nanocrystal Materials Most nanocrystal materials are made up of small crystals, called "grains," and what happens at the boundaries between these grains is critical to material properties. Based on computer simulations and electron microscopy analysis, the belief has been that dislocation-mediated plastic deformation becomes inactive below a grain size of at least 10 nanometers, and possibly as large as 30 nanometers.

68

Shedding Light on Nanocrystal Defects  

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

Shedding Light on Nanocrystal Defects Print Shedding Light on Nanocrystal Defects Print Nanocrystals have been the focus of much scientific interest lately, given their various advantageous mechanical properties. Their resistance to stress has had researchers proposing nanocrystals as a promising new protective coating for advanced gas turbine and jet engines. But recent studies conducted at the ALS show that the tiny size of nanocrystals does not safeguard them from defects. Engineering Nanocrystal Materials Most nanocrystal materials are made up of small crystals, called "grains," and what happens at the boundaries between these grains is critical to material properties. Based on computer simulations and electron microscopy analysis, the belief has been that dislocation-mediated plastic deformation becomes inactive below a grain size of at least 10 nanometers, and possibly as large as 30 nanometers.

69

Shedding Light on Nanocrystal Defects  

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

Shedding Light on Nanocrystal Shedding Light on Nanocrystal Defects Shedding Light on Nanocrystal Defects Print Thursday, 20 June 2013 10:41 Nanocrystals have been the focus of much scientific interest lately, given their various advantageous mechanical properties. Their resistance to stress has had researchers proposing nanocrystals as a promising new protective coating for advanced gas turbine and jet engines. But recent studies conducted at the ALS show that the tiny size of nanocrystals does not safeguard them from defects. Engineering Nanocrystal Materials Most nanocrystal materials are made up of small crystals, called "grains," and what happens at the boundaries between these grains is critical to material properties. Based on computer simulations and electron microscopy analysis, the belief has been that dislocation-mediated plastic deformation becomes inactive below a grain size of at least 10 nanometers, and possibly as large as 30 nanometers.

70

Shedding Light on Nanocrystal Defects  

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

Shedding Light on Nanocrystal Defects Print Shedding Light on Nanocrystal Defects Print Nanocrystals have been the focus of much scientific interest lately, given their various advantageous mechanical properties. Their resistance to stress has had researchers proposing nanocrystals as a promising new protective coating for advanced gas turbine and jet engines. But recent studies conducted at the ALS show that the tiny size of nanocrystals does not safeguard them from defects. Engineering Nanocrystal Materials Most nanocrystal materials are made up of small crystals, called "grains," and what happens at the boundaries between these grains is critical to material properties. Based on computer simulations and electron microscopy analysis, the belief has been that dislocation-mediated plastic deformation becomes inactive below a grain size of at least 10 nanometers, and possibly as large as 30 nanometers.

71

Shedding Light on Nanocrystal Defects  

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

Shedding Light on Nanocrystal Defects Print Shedding Light on Nanocrystal Defects Print Nanocrystals have been the focus of much scientific interest lately, given their various advantageous mechanical properties. Their resistance to stress has had researchers proposing nanocrystals as a promising new protective coating for advanced gas turbine and jet engines. But recent studies conducted at the ALS show that the tiny size of nanocrystals does not safeguard them from defects. Engineering Nanocrystal Materials Most nanocrystal materials are made up of small crystals, called "grains," and what happens at the boundaries between these grains is critical to material properties. Based on computer simulations and electron microscopy analysis, the belief has been that dislocation-mediated plastic deformation becomes inactive below a grain size of at least 10 nanometers, and possibly as large as 30 nanometers.

72

Shedding Light on Nanocrystal Defects  

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

Shedding Light on Nanocrystal Defects Print Shedding Light on Nanocrystal Defects Print Nanocrystals have been the focus of much scientific interest lately, given their various advantageous mechanical properties. Their resistance to stress has had researchers proposing nanocrystals as a promising new protective coating for advanced gas turbine and jet engines. But recent studies conducted at the ALS show that the tiny size of nanocrystals does not safeguard them from defects. Engineering Nanocrystal Materials Most nanocrystal materials are made up of small crystals, called "grains," and what happens at the boundaries between these grains is critical to material properties. Based on computer simulations and electron microscopy analysis, the belief has been that dislocation-mediated plastic deformation becomes inactive below a grain size of at least 10 nanometers, and possibly as large as 30 nanometers.

73

Effect of interstitials on the mechanical behavior of P/M tantalum  

SciTech Connect

Microstructural characterization by transmission electron microscopy (TEM) has been used in an investigation of the effects of interstitial alloy content on the mechanical properties of P/M tantalum. Compacts were prepared by cold isostatic pressing (CIP) at 50 ksi (345 MPa) followed by hot isostatic pressing (HIP) at 30 ksi (207 MPa) at 1,600 C. Increases in both yield and flow stresses were observed in ambient temperature, quasi-static compression tests due to increases in interstitial alloy content. Variations in yield stress were attributed to solid solution strengthening due to interstitial elements, since no oxides, nitrides or carbides were observed via TEM.

Strutt, A.J.; Vecchio, K.S. [Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences; Bingert, S.R.; Gray, G.T. III [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

1996-06-01T23:59:59.000Z

74

Defective Interfering Particles of Poliovirus I. Isolation and Physical Properties  

Science Journals Connector (OSTI)

...gel, and electrophoresis was car- ried out at 5 ma/gel for...anode is at the right. POLIO DEFECTIVE PARTICLES TABLE 1. Annealing of unlabeled standard and defective intferfering [DI(I)] ribonucleic...formed by replication of the defective RNA by a mechanism similar...

Charles N. Cole; Donna Smoler; Eckard Wimmer; David Baltimore

1971-04-01T23:59:59.000Z

75

Modelling the Thermo-Mechanical Behavior of Magnesium Alloys during Indirect Extrusion  

SciTech Connect

One of the basic metal forming process for semi-finished products is extrusion. Since extrusion involves complex thermo-mechanical and multiaxial loading conditions resulting in large strains, high strain rates and an increase in temperature due to deformation, a proper yield criterion and hardening law should be used in the numerical modelling of the process. A phenomenological model based on a plastic potential has been proposed that takes strain, strain rate and temperature dependency on flow behaviour into consideration. A hybrid methodology of experiment and finite element simulation has been adopted in order to obtain necessary model parameters. The anisotropy/asymmetry in yielding was quantified by tensile and compression tests of specimens prepared from different directions. The identification of the corresponding model parameters was performed by a genetic algorithm. A fully coupled thermo-mechanical analysis has been used in extrusion simulations for calculation of the temperature field by considering heat fluxes and heat generated due to plastic deformation. The results of the approach adopted in this study appeared to be successful showing promising predictions of the experiments and thus may be extended to be applicable to other magnesium alloys or even other hcp metals.

Steglich, D. [GKSS Research Centre, Geesthacht (Germany); G.I.F.T., POSTECH, Pohang, Gyeongbuk (Korea, Republic of); Ertuerk, S.; Bohlen, J.; Letzig, D. [GKSS Research Centre, Geesthacht (Germany); Brocks, W. [Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany)

2010-06-15T23:59:59.000Z

76

Polymer/clay aerogel composites with flame retardant agents: Mechanical, thermal and fire behavior  

Science Journals Connector (OSTI)

Abstract Aerogel is a class of material characterized by its high void content and extreme lightness. Different polymer/clay aerogels have been prepared by a simply freezethaw process from a suspension with poly(vinyl alcohol) (PVOH) and clay (Na+-MMT). Low density polymer/clay aerogels modified with flame retardant agents were prepared using a similar approach. The addition of flame retardant agents slightly increased the apparent density of the final composites whereas the compression properties were reduced due to the decrease in the polymer/clay interfacial bonding. An exception was the sample containing Al(OH)3 that exhibited higher modulus and stress at maximum deformation. Regarding thermal properties, the presence of ammonium polyphosphate (APP) or silica gel (SG) significantly slowed the rate of aerogel decomposition at the temperature range from 250C to 500C while the onset of polymer decomposition was not affected. Fire behavior was analyzed through cone calorimeter suggesting that either the presence of Al(OH)3 or APP reduced the heat release rate of PVOH/clay systems.

Liang Wang; Miguel Snchez-Soto; Maria Lluisa Maspoch

2013-01-01T23:59:59.000Z

77

Influences of semiconductor morphology on the mechanical fatigue behavior of flexible organic electronics  

SciTech Connect

The influence of crystalline morphology on the mechanical fatigue of organic semiconductors (OSCs) was investigated using 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) as a crystalline OSC and poly(triarylamine) (PTAA) as an amorphous OSC. During cyclic bending, resistances of the OSCs were monitored using the transmission-line method on a metal-semiconductor-metal structure. The resistance of the TIPS-pentacene increased under fatigue damage in tensile-stress mode, but no such degradation was observed in the PTAA. Both OSCs were stable under compressive bending fatigue. The formation of intergranular cracks at the domain boundaries of the TIPS-pentacene was responsible for the degradation of its electrical properties under tensile bending fatigue.

Lee, Young-Joo; Yeon, Han-Wool; Shin, Hae-A-Seul; Joo, Young-Chang, E-mail: ycjoo@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of); Uk Lee, Yong; Evans, Louise A. [Center for Process Innovation Limited, Thomas Wright Way, NETPark, Sedgefield, TS21 3FG County Durham (United Kingdom)] [Center for Process Innovation Limited, Thomas Wright Way, NETPark, Sedgefield, TS21 3FG County Durham (United Kingdom)

2013-12-09T23:59:59.000Z

78

Holographic Experiments on Defects  

E-Print Network (OSTI)

Using the AdS/CFT correspondence, we study the anisotropic charge transport properties of both supersymmetric and non-supersymmetric matter fields on (2+1)-dimensional defects coupled to a (3+1)-dimensional N=4 SYM "heat bath". We focus on the cases of a finite external background magnetic field, finite net charge density and finite mass and their combinations. In this context, we also discuss the limitations due to operator mixing that appears in a few situations and that we ignore in our analysis. At high frequencies, we discover a spectrum of quasi-particle resonances due to the magnetic field and finite density and at small frequencies, we perform a Drude-like expansion around the DC limit. Both of these regimes display many generic features and some features that we attribute to strong coupling, such as a minimum DC conductivity and an unusual behavior of the "cyclotron" and plasmon frequencies, which become related to the resonances found in the conformal case in an earlier paper. We further study the hydrodynamic regime and the relaxation properties, from which the system displays a set of different possible transitions to the collisionless regime. The mass dependence can be cast in two regimes: a generic relativistic behavior dominated by the UV and a non-linear hydrodynamic behavior dominated by the IR. In the massless case, we furthermore extend earlier results from the literature to find an interesting self-duality under a transformation of the conductivity and the exchange of density and magnetic field.

Matthias C Wapler

2009-09-08T23:59:59.000Z

79

Mechanical behavior of Fermilab/General Dynamics built 15M SSC collider dipoles  

SciTech Connect

A series of full-scale demonstration SSC collider dipole magnets were built for the ASST. These magnets, DCA311 through DCA319, have 50 mm aperture and 15 m magnetic length with 6.6 Tesla uniform field. For the support structure of the W6733B cross section, the Fermilab design uses a vertical split in the yoke. The end sections of the magnet have solid spacers and are supported by collet clamps. The splices between inner and outer coils are made in preforms which lie outside of the high field region. The magnets were produced in pipeline fashion with no intentional major changes between magnets. As a part of the technology transfer program, the last 7 magnets were built by General Dynamics personnel using the magnet construction facilities of Fermilab, while the first two magnets were built entirely by Fermilab personnel. At present, the magnets up to DCA316 have been tested at Fermilab. The general characteristics of the magnets have been quite satisfactory. Both of the Fermilab built magnets have reached the conductor limited field strength with no significant training. Two of the General Dynamics built magnets each required a single training quench. However, all of the magnets tested up to date meet the ASST specifications. This report describes the mechanical properties of the ASST magnets at Fermilab based on the currently available test results.

Wake, M.; Bleadon, M.; Bossert, R.; Carson, J.; Delchamps, S.; Gourlay, S.; Hanft, R.; Koska, W.; Kuchnir, M.; Lamm, M.; Mazur, P.; Orris, D.; Strait, J. [Fermi National Accelerator Lab., Batavia, IL (United States); Devred, A.; DiMarco, J.; Kuzminski, J.; Nah, W.; Ogitsu, T.; Puglisi, M.; Thompkins, J.; Yu, Y.; Zhao, Y.; Zheng, H. [Superconducting Super Collider Lab., Dallas, TX (United States)

1992-04-01T23:59:59.000Z

80

Impact of substrate temperature on the incorporation of carbon-related defects and mechanism for semi-insulating behavior in GaN grown by molecular beam epitaxy  

E-Print Network (OSTI)

B 22, 1145 ?2004?. A. Armstrong, A. R. Arehart, D. Green, U.San Diego, 1992?. A. Armstrong, A. R. Arehart, and S. A.molecular beam epitaxy A. Armstrong Department of Electrical

Armstrong, A; Poblenz, C; Green, D S; Mishra, U K; Speck, J S; Ringel, S A

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Holographic Experiments on Defects  

E-Print Network (OSTI)

Using the AdS/CFT correspondence, we study the anisotropic charge transport properties of both supersymmetric and non-supersymmetric matter fields on (2+1)-dimensional defects coupled to a (3+1)-dimensional ${\\cal N}=4$ SYM "heat bath". We focus on the case of a finite external background magnetic field, finite net charge density and finite mass. At high frequencies, we discover a spectrum of quasiparticle resonances due to the magnetic field and finite density and at small frequencies, we perform a Drude-like expansion around the DC limit. Both of these regimes display many generic features and some features that we attribute to strong coupling, such as a minimum DC conductivity and an unusual behavior of the "cyclotron" and plasmon frequencies, which become related to the resonances found in the conformal case in an earlier paper. We further study the hydrodynamic regime and the relaxation properties, from which the system displays a set of different possible transitions to the collisionless regime. The mas...

Wapler, Matthias C

2009-01-01T23:59:59.000Z

82

Formation of topological defects in first order phase transitions  

Science Journals Connector (OSTI)

We analyze the evolution of scalar and gauge fields during first-order phase transitions and show how the Kibble mechanism for the formation of topological defects emerges from the underlying dynamics, paying particular attention to problems posed by gauge invariance when a local symmetry is spontaneously broken. We discuss also the application of the mechanism to semilocal defects and electroweak strings.

Mark Hindmarsh; Anne-Christine Davis; Robert Brandenberger

1994-02-15T23:59:59.000Z

83

Investigation of thermal, mechanical and magnetic behaviors of the Cu-11%Al alloy with Ag and Mn additions  

SciTech Connect

The investigation of thermal, mechanical and magnetic behaviors of the Cu-11%Al, Cu-11%Al-3%Ag, Cu-11%Al-10%Mn and Cu-11%Al-10%Mn-3%Ag alloys was made using microhardness measurements, differential scanning calorimetry, X-ray diffractometry, scanning electron microscopy, energy dispersion X-ray spectroscopy and magnetic moment change with applied field measurement. The results indicated that the Mn addition changes the phase stability range, the microhardness values and makes undetectable the eutectoid reaction in annealed Cu-11%Al and Cu-11%Al-3%Ag alloys while the presence of Ag does not modify the phase transformation sequence neither microhardness values of the annealed Cu-11%Al and Cu-11%Al-10%Mn alloys, but it increases the magnetic moment of this latter at about 2.7 times and decreases the rates of eutectoid and peritectoid reactions of the former. - Highlights: Black-Right-Pointing-Pointer The microstructure of Cu-Al alloy is modified in the Ag presence. Black-Right-Pointing-Pointer ({alpha} + {gamma}) phase is stabilized down to room temperature when Ag is added to Cu-Al alloy. Black-Right-Pointing-Pointer Ag-rich phase modifies the magnetic characteristics of Cu-Al-Mn alloy.

Silva, R.A.G., E-mail: galdino.ricardo@gmail.com [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil)] [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil); Paganotti, A.; Gama, S. [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil)] [Departamento de Ciencias Exatas e da Terra-UNIFESP, Diadema-SP (Brazil); Adorno, A.T.; Carvalho, T.M.; Santos, C.M.A. [Instituto de Quimica - UNESP, Araraquara-SP (Brazil)] [Instituto de Quimica - UNESP, Araraquara-SP (Brazil)

2013-01-15T23:59:59.000Z

84

Intrinsic structural defects in monolayer molybdenum disulfide  

SciTech Connect

Monolayer molybdenum disulfide (MoS2) is a two-dimensional direct band gap semiconductor with distinctive mechanical, electronic, optical and chemical properties that can be utilized for novel nanoelectronics and optoelectronics devices. The performance of these electronic devices strongly depends on the quality and defect morphology of the MoS2 layers. Yet, little is known about the atomic structure of defects present in monolayer MoS2 and their influences on the material properties. Here we provide a systematic study of various intrinsic structural defects, including point defects, grain boundaries, and edges, in chemical vapor phase grown monolayer MoS2 via direct atomic resolution imaging, and explore their energy landscape and electronic properties using first-principles calculations. We discover that one-dimensional metallic wires can be created via two different types of 60 grain boundaries consisting of distinct 4-fold ring chains. A new type of edge reconstruction, representing a transition state during growth, was also identified, providing insights into the material growth mechanism. The atomic scale study of structural defects presented here brings new opportunities to tailor the properties of MoS2 via controlled synthesis and defect engineering.

Zhou, Wu [ORNL; Idrobo Tapia, Juan C [ORNL

2013-01-01T23:59:59.000Z

85

Bonding defects in hydrogenated amorphous silicon  

SciTech Connect

A mechanism for charged-carrier-trapping-induced defect metastability in hydrogenated amorphous silicon (a-Si:H) and in hydrogenated amorphous silicon alloys containing relatively high concentrations of oxygen and/or nitrogen atoms (a-Si:X:H, X = O or N) is described. The experimental results that identified this defect metastability mechanism were (i) differences in the Staebler-Wronski effect in a-Si:H and a-Si:N:H alloys prepared from N{sub 2} and NH{sub 3} source gases by remote plasma-enhanced chemical-vapor deposition, and (ii) differences in defect generation at N-atom terminated Si-SiO{sub 2} interfaces prepared from NH{sub 3} and N{sub 2}O.

Lucovsky, G.; Yang, H. [North Carolina State Univ., Raleigh, NC (United States)

1996-12-31T23:59:59.000Z

86

Modelling of thermo-mechanical and irradiation behavior of metallic and oxide fuels for sodium fast reactors  

E-Print Network (OSTI)

A robust and reliable code to model the irradiation behavior of metal and oxide fuels in sodium cooled fast reactors is developed. Modeling capability was enhanced by adopting a non-empirical mechanistic approach to the ...

Karahan, Aydin

2009-01-01T23:59:59.000Z

87

Intrinsic Nanoscience of ? PuGa Alloys: Local Structure and Speciation, Collective Behavior, Nanoscale Heterogeneity, and Aging Mechanisms  

Science Journals Connector (OSTI)

Materials Science and Technology Division, Theoretical Division, Health, Safety, Radiation Protection Division, and ?Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States ... The EXAFS were calculated as the difference between the full spectra and their smooth atomic backgrounds approximated by an arctangent and Gaussian for the edge and a polynomial spline at higher energies, divided by the atomic absorbance fall off with increasing energy. ... That the Ga environment is only minimally or negligibly affected by aging implies that the aging-induced defects, whether isolated or as novel ordered structures, almost exclusively involve Pu sites and are thus concentrated in Ga-depleted domains in the crystal that must therefore reform if they are lost at some point in the aging process. ...

Steven D. Conradson; Nicolas Bock; Julio M. Castro; Dylan R. Conradson; Lawrence E. Cox; Wojciech Dmowski; David E. Dooley; Takeshi Egami; Francisco J. Espinosa-Faller; Franz J. Freibert; Angel J. Garcia-Adeva; Nancy J. Hess; Erik Holmstrm; Rafael C. Howell; Barbara A. Katz; Jason C. Lashley; Raymond J. Martinez; David P. Moore; Luis A. Morales; J. David Olivas; Ramiro A. Pereyra; Michael Ramos; Jeffrey H. Terry; Phillip M. Villella

2014-03-24T23:59:59.000Z

88

EFFECT OF AL2O3 ALD NANOCOATINGS ON THE THERMO-MECHANICAL BEHAVIOR OF AU/SI MEMS STRUCTURES  

E-Print Network (OSTI)

subjected to thermal holds and thermal cycling after release. Thin films attached to ceramic substrates various thermal and mechanical loading conditions. In the present study, we examine the thermo- mechanical experience in- plane stresses due to differences in the thermal expansion coefficients between adjacent

George, Steven M.

89

Structural phase transitions and topological defects in ion Coulomb crystals  

Science Journals Connector (OSTI)

Abstract We use laser-cooled ion Coulomb crystals in the well-controlled environment of a harmonic radiofrequency ion trap to investigate phase transitions and defect formation. Topological defects in ion Coulomb crystals (kinks) have been recently proposed for studies of nonlinear physics with solitons and as carriers of quantum information. Defects form when a symmetry breaking phase transition is crossed nonadiabatically. For a second order phase transition, the KibbleZurek mechanism predicts that the formation of these defects follows a power law scaling in the rate of the transition. We demonstrate a scaling of defect density and describe kink dynamics and stability. We further discuss the implementation of mass defects and electric fields as first steps toward controlled kink preparation and manipulation.

Heather L. Partner; Ramil Nigmatullin; Tobias Burgermeister; Jonas Keller; Karsten Pyka; Martin B. Plenio; Alex Retzker; Wojciech H. Zurek; Adolfo del Campo; Tanja E. Mehlstubler

2014-01-01T23:59:59.000Z

90

Structural phase transitions and topological defects in ion Coulomb crystals  

E-Print Network (OSTI)

We use laser-cooled ion Coulomb crystals in the well-controlled environment of a harmonic radiofrequency ion trap to investigate phase transitions and defect formation. Topological defects in ion Coulomb crystals (kinks) have been recently proposed for studies of nonlinear physics with solitons and as carriers of quantum information. Defects form when a symmetry breaking phase transition is crossed nonadiabatically. For a second order phase transition, the Kibble-Zurek mechanism predicts that the formation of these defects follows a power law scaling in the rate of the transition. We demonstrate a scaling of defect density and describe kink dynamics and stability. We further discuss the implementation of mass defects and electric fields as first steps toward controlled kink preparation and manipulation.

Heather L. Partner; Ramil Nigmatullin; Tobias Burgermeister; Jonas Keller; Karsten Pyka; Martin B. Plenio; Alex Retzker; Wojciech H. Zurek; Adolfo del Campo; Tanja E. Mehlstubler

2014-11-19T23:59:59.000Z

91

Behavior and rupture of hydrided Zircaloy-4 tubes and sheets  

SciTech Connect

Zirconium alloys are used as structural parts in the nuclear fuel assembly. The mechanical behavior and rupture mechanisms of ZIRCALOY-4 guide tubes and sheet containing 150 to 1,200 wt ppm hydrogen have been investigated at room temperature. Sheets were notched to study the influence of geometrical defects on rupture. It is shown that hydrides strengthened the material, as maximum stresses sustained by the material are increased with increasing hydrogen contents. On the other hand, ductility is reduced. The material also exhibits a strong anisotropy due to its pronounced texture. Metallographic examinations have shown that damage by hydride cracking is a continuous process that starts after the onset of necking. Notches reduce ductility. A modified Gurson-Tvergaard model was used to represent the material behavior and rupture. Numerical simulation using the finite element method demonstrates the strong influence of plastic anisotropy on the behavior of structures and rupture modes.

Prat, F.; Besson, J. [Ecole des Mines de Paris, Evry (France); Grange, M. [Framatome Nuclear Fuel, Lyon (France); Andrieu, E. [ENSCT, Toulouse (France). Lab. Materiaux

1998-06-01T23:59:59.000Z

92

Mayne, P.W., Coop, M.R., Springman, S., Huang, A-B., and Zornberg, J. (2009). State-of-the-Art Paper (SOA-1): GeoMaterial Behavior and Testing. Proc. 17th Intl. Conf. Soil Mechanics & Geotechnical  

E-Print Network (OSTI)

Mayne, P.W., Coop, M.R., Springman, S., Huang, A-B., and Zornberg, J. (2009). State-of-the-Art Paper (SOA-1): GeoMaterial Behavior and Testing. Proc. 17th Intl. Conf. Soil Mechanics & Geotechnical

Mayne, Paul W.

93

EFFECT OF AGING ON THE PHASE TRANSFORMATION AND MECHANICAL BEHAVIOR OF Ti36Ni49Hf15 HIGH  

E-Print Network (OSTI)

and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China (Received August 19 the microstructure, transformation temperature, mechanical properties and shape memory effects (SMEs) for Ti36Ni49Hf

Zheng, Yufeng

94

Microstructural Characterization of the Chemo-mechanical Behavior of Asphalt in Terms of Aging and Fatigue Performance Properties  

E-Print Network (OSTI)

implements the framework of chemo-mechanics by investigating two types of chemical modification processes, natural (oxidative aging) and synthetic (chemical doping) as they relate not only to macro-scale properties of asphalt binder but also to the asphalt...

Allen, Robert Grover

2013-03-27T23:59:59.000Z

95

Mechanical relaxation behavior of polyurethanes reinforced with the in situ-generated sodium silica-polyphosphate nanophase  

E-Print Network (OSTI)

Further exploration of hybrid organic/inorganic composites (polyurethane based with inorganic material sodium silica polyphosphate) properties with mechanical relaxometer gives ability to analyze microstructure of such materials in terms of chain reptation tubes filler's fractal aggregates and stress amplification.

V. O. Dupanov; S. M. Ponomarenko

2014-10-31T23:59:59.000Z

96

Affine Defects and Gravitation  

E-Print Network (OSTI)

We argue that the structure general relativity (GR) as a theory of affine defects is deeper than the standard interpretation as a metric theory of gravitation. Einstein-Cartan theory (EC), with its inhomogenous affine symmetry, should be the standard-bearer for GR-like theories. A discrete affine interpretation of EC (and gauge theory) yields topological definitions of momentum and spin (and Yang Mills current), and their conservation laws become discrete topological identities. Considerations from quantum theory provide evidence that discrete affine defects are the physical foundation for gravitation.

R. J. Petti

2014-12-12T23:59:59.000Z

97

Application of the multi-mechanism deformation model for three-dimensional simulations of salt : behavior for the strategic petroleum reserve.  

SciTech Connect

The U.S. Strategic Petroleum Reserve stores crude oil in 62 solution-mined caverns in salt domes located in Texas and Louisiana. Historically, three-dimensional geomechanical simulations of the behavior of the caverns have been performed using a power law creep model. Using this method, and calibrating the creep coefficient to field data such as cavern closure and surface subsidence, has produced varying degrees of agreement with observed phenomena. However, as new salt dome locations are considered for oil storage facilities, pre-construction geomechanical analyses are required that need site-specific parameters developed from laboratory data obtained from core samples. The multi-mechanism deformation (M-D) model is a rigorous mathematical description of both transient and steady-state creep phenomena. Recent enhancements to the numerical integration algorithm within the model have created a more numerically stable implementation of the M-D model. This report presents computational analyses to compare the results of predictions of the geomechanical behavior at the West Hackberry SPR site using both models. The recently-published results using the power law creep model produced excellent agreement with an extensive set of field data. The M-D model results show similar agreement using parameters developed directly from laboratory data. It is also used to predict the behavior for the construction and operation of oil storage caverns at a new site, to identify potential problems before a final cavern layout is designed.

Ehgartner, Brian L.; Sobolik, Steven Ronald; Bean, James E.

2010-07-01T23:59:59.000Z

98

Microstructural development and mechanical behavior of eutectic bismuth-tin and eutectic indium-tin in response to high temperature deformation  

SciTech Connect

The mechanical behavior and microstructure of eutectic Bi-Sn and In-Sn solders were studied in parallel in order to better understand high temperature deformation of these alloys. Bi-Sn solder joints were made with Cu substrates, and In-Sn joints were made with either Cu or Ni substrates. The as-cast microstructure of Bi-Sn is complex regular, with the two eutectic phases interconnected in complicated patterns. The as-cast microstructure of In-Sn depends on the substrate. In-Sn on Cu has a non-uniform microstructure caused by diffusion of Cu into the solder during sample preparation, with regions of the Sn-rich {gamma} phase imbedded in a matrix of the In-rich {beta} phase. The microstructure of In-Sn on Ni is uniform and lamellar and the two phases are strongly coupled. The solders deform non-uniformly, with deformation concentrating in a band along the length of the sample for Bi-Sn and In-Sn on Cu, though the deformation is more diffuse in In-Sn than in Bi-Sn. Deformation of In-Sn on Ni spreads throughout the width of the joint. The different deformation patterns affect the shape of the stress-strain curves. Stress-strain curves for Bi-Sn and In-Sn on Cu exhibit sharp decays in the engineering stress after reaching a peak. Most of this stress decay is removed for In-Sn on Ni. The creep behavior of In-Sn also depends on the substrate, with the creep deformation controlled by the soft P phase of the eutectic for In-Sn on Cu and controlled by the harder {gamma} phase for In-Sn on Ni. When In-Sn on Ni samples are aged, the microstructure coarsens and changes to an array of {gamma} phase regions in a matrix of the {beta} phase, and the creep behavior changes to resemble that of In-Sn on Cu. The creep behavior of Bi-Sn changes with temperature. Two independent mechanisms operate at lower temperatures, but there is still some question as to whether one or both of these, or a third mechanism, operates at higher temperatures.

Goldstein, J.L.F. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; [Lawrence Berkeley Lab., CA (United States)

1993-11-01T23:59:59.000Z

99

Photoconductivity Studies of Defects in p-Type Silicon: Boron Interstitial and Aluminum Interstitial Defects  

Science Journals Connector (OSTI)

Two defects introduced in p-type silicon by 1.5-MeV electron irradiation are studied by means of infrared photoconductivity, including the measurement of the stress-induced dichroism. They are identified as being dopant atoms in interstitial positions produced by the silicon interstitial-impurity atom replacement mechanism proposed by Watkins. They are introduced by room-temperature irradiations as well as by irradiations performed at 77, 20.4, and 4.2K. They disappear during annealing at temperatures ?250-300C. The symmetry of these defects C3v is deduced from the low-temperature stress-induced dichroism of the photoconductivity which is associated with electronic reorientation among different configurations. This C3v symmetry can be explained by distortion of a possible Jahn-Teller type of a configuration in which the dopant atom was originally in a tetrahedral position. The defect response to the stress is determined by the value of the term in the piezospectroscopic defect tensor which characterizes the relative change in defect energy per unit strain. This value is ? -12 eV/(unit strain). Numerical values of the dichroic ratios show that the photoconductivity transition which is observed corresponds to a distribution of dipole moments which is an ellipsoid of rotation about the trigonal axis of the defect. They also allow the determination of this distribution.

M. Cherki and A. H. Kalma

1970-01-15T23:59:59.000Z

100

Review on the effects of hydrogen at extreme pressures and temperatures on the mechanical behavior of polymers.  

SciTech Connect

The effects of hydrogen on the mechanics (e.g. strength, ductility, and fatigue resistance) of polymer materials are outlined in this report. There are a small number of studies reported in the literature on this topic, and even fewer at the extreme temperatures to which hydrogen service materials will be exposed. Several studies found little evidence that hydrogen affects the static tensile properties, long term creep, or ductile fracture of high density polyethylene or polyamide. However, there has been a report that a recoverable drop in the modulus of high density polyethylene is observable under high hydrogen pressure. A research need exists on the mechanical effects of hydrogen on the wide range of polymers used or considered for use in the hydrogen economy, due to the lack of data in the literature.

Hecht, Ethan S.

2013-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Defect mapping system  

DOE Patents (OSTI)

Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities. 20 figures.

Sopori, B.L.

1995-04-11T23:59:59.000Z

102

Counting Defective Parking Functions  

E-Print Network (OSTI)

Suppose that $n$ drivers each choose a preferred parking space in a linear car park with $m$ spaces. Each driver goes to the chosen space and parks there if it is free, and otherwise takes the first available space with larger number (if any). If all drivers park successfully, the sequence of choices is called a parking function. In general, if $k$ drivers fail to park, we have a \\emph{defective parking function} of \\emph{defect} $k$. Let $\\cp(n,m,k)$ be the number of such functions. In this paper, we establish a recurrence relation for the numbers $\\cp(n,m,k)$, and express this as an equation for a three-variable generating function. We solve this equation using the kernel method, and extract the coefficients explicitly: it turns out that the cumulative totals are partial sums in Abel's binomial identity. Finally, we compute the asymptotics of $\\cp(n,m,k)$. In particular, for the case $m=n$, if choices are made independently at random, the limiting distribution of the defect (the number of drivers who fail t...

Cameron, Peter J; Prellberg, Thomas; Schweitzer, Pascal

2008-01-01T23:59:59.000Z

103

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

104

Invisible defects in complex crystals  

E-Print Network (OSTI)

We show that invisible localized defects, i.e. defects that can not be detected by an outside observer, can be realized in a crystal with an engineered imaginary potential at the defect site. The invisible defects are synthesized by means of supersymmetric (Darboux) transformations of an ordinary crystal using band-edge wave functions to construct the superpotential. The complex crystal has an entire real-valued energy spectrum and Bragg scattering is not influenced by the defects. An example of complex crystal synthesis is presented for the Mathieu potential.

S. Longhi; G. Della Valle

2013-06-04T23:59:59.000Z

105

Attractor Flows from Defect Lines  

E-Print Network (OSTI)

Deforming a two dimensional conformal field theory on one side of a trivial defect line gives rise to a defect separating the original theory from its deformation. The Casimir force between these defects and other defect lines or boundaries is used to construct flows on bulk moduli spaces of CFTs. It turns out, that these flows are constant reparametrizations of gradient flows of the g-functions of the chosen defect or boundary condition. The special flows associated to supersymmetric boundary conditions in N=(2,2) superconformal field theories agree with the attractor flows studied in the context of black holes in N=2 supergravity.

Ilka Brunner; Daniel Roggenkamp

2010-02-12T23:59:59.000Z

106

Effect of reinforcing particle type on morphology and age-hardening behavior of Al4.5 wt.% Cu based nanocomposites synthesized through mechanical milling  

SciTech Connect

The effects of reinforcing particle type (SiC and TiC) on morphology and precipitation hardening behavior of Al4.5%Cu based nanocomposites synthesized via mechanical milling were investigated in the current work. In order to study the microstructure and morphology of mechanically milled powder, X-ray diffraction technique, scanning electron microscopy and high resolution transmission electron microscopy were utilized. Results revealed that at the early stages of mechanical milling, when reinforcing particles are polycrystal, the alloying process is enhanced more in the case of using the TiC particles as reinforcement. But, at the final stages of mechanical milling, when reinforcing particles are single crystal, the alloying process is enhanced more in the case of using the SiC ones. Transmission electron microscopy results demonstrated that Al4.5 wt.%Cu based nanocomposite powders were synthesized and confirmed that the mutual diffusion of aluminum and copper occurs through the interfacial plane of (200). The hardness results showed that not only does introducing 4 vol.% of reinforcing particles (SiC or TiC) considerably decrease the porosity of the bulk composite samples, but also it approximately doubles the hardness of Al4.5 wt.%Cu alloy (53.4 HB). Finally, apart from TEM and scanning electron microscopy observation which are localized, a decline in hardness in the TiC and SiC contained samples, respectively, after 1.5 and 2 h aging time at 473 K proves the fact that the size of SiC particles is smaller than the size of the TiC ones. - Highlights: ? HRTEM results show mutual diffusion of Al and Cu occurs through the (200) planes. ? TiC particles enhance alloying process more than the SiC ones at the early stages of MM. ? SiC particles enhance alloying process more than the TiC ones at the final stages of MM.

Mostaed, A., E-mail: alimostaed@yahoo.com [Advanced Materials and Nanotechnology Research Center, Faculty of Mechanical Engineering, K.N. Toosi University of Technology, 16765-3381 Pardis Street, Tehran (Iran, Islamic Republic of); Saghafian, H.; Mostaed, E. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Narmak, Tehran (Iran, Islamic Republic of); Shokuhfar, A. [Advanced Materials and Nanotechnology Research Center, Faculty of Mechanical Engineering, K.N. Toosi University of Technology, 16765-3381 Pardis Street, Tehran (Iran, Islamic Republic of); Rezaie, H.R. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Narmak, Tehran (Iran, Islamic Republic of)

2013-02-15T23:59:59.000Z

107

Constitutive Model for the Time-Dependent Mechanical Behavior of 430 Stainless Steel and FeCrAlY Foams in Sulfur-Bearing Environments  

SciTech Connect

The mechanical behavior of 430 stainless steel and pre-oxidized FeCrAlY open-cell foam materials of various densities was evaluated in compression at temperatures between 450 C and 600 C in an environment containing hydrogen sulfide and water vapor. Both materials showed negligible corrosion due to the gaseous atmosphere for up to 168 hours. The monotonic stress-strain response of these materials was found to be dependent on both the strain rate and their density, and the 430 stainless steel foam materials exhibited less stress relaxation than FeCrAlY for similar experimental conditions. Using the results from multiple hardening-relaxation and monotonic tests, an empirical constitutive equation was derived to predict the stress-strain behavior of FeCrAlY foams as a function of temperature and strain rate. These results are discussed in the context of using these materials in a black liquor gasifier to accommodate the chemical expansion of the refractory liner resulting from its reaction with the soda in the black liquor.

Hemrick, James Gordon [ORNL; Lara-Curzio, Edgar [ORNL

2013-01-01T23:59:59.000Z

108

Behavior of passaged chondrocytes in collagen-glycosaminoglycan scaffolds : effects of cross-linking, mechanical loading, and genetic modification of the scaffold  

E-Print Network (OSTI)

Tissue engineering is a promising solution to the problematic healing of cartilage defects. The purpose of this thesis was to establish a foundation for the development of a collagen-glycosaminoglycan (CG) scaffold for ...

Lee, Cynthia R. (Cynthia Renee), 1975-

2002-01-01T23:59:59.000Z

109

Crystallization Behavior of Virgin TR-55 Silicone Rubber Measured Using Dynamic Mechanical Thermal Analysis with Liquid Nitrogen Cooling  

SciTech Connect

Dynamic mechanical thermal analysis (DMTA) of virgin TR-55 silicone rubber specimens was conducted. Two dynamic temperature sweep tests, 25 to -100 C and 25 to -70 to 0 C (ramp rate = 1 C/min), were conducted at a frequency of 6.28 rad/s (1 Hz) using a torsion rectangular test geometry. A strain of 0.1% was used, which was near the upper limit of the linear viscoelastic region of the material based on an initial dynamic strain sweep test. Storage (G{prime}) and loss (G{double_prime}) moduli, the ratio G{double_prime}/G{prime} (tan {delta}), and the coefficient of linear thermal expansion ({alpha}) were determined as a function of temperature. Crystallization occurred between -40 and -60 C, with G{prime} increasing from {approx}6 x 10{sup 6} to {approx}4 x 10{sup 8} Pa. The value of {alpha} was fairly constant before ({approx}4 x 10{sup -4} mm/mm- C) and after ({approx}3 x 10{sup -4} mm/mm- C) the transition, and peaked during the transition ({approx}3 x 10{sup -3} mm/mm- C). Melting occurred around -30 C upon heating.

Small IV, W; Wilson, T S

2010-02-11T23:59:59.000Z

110

On the compensation mechanism of amorphous silicon films: Study of stability  

SciTech Connect

The authors investigated a-Si:H compensated materials deposited over a wide range of gas dopant concentrations, from 0.125 ppm up to 10{sup 3} ppm. They achieved compensation for different ratio in the gas phase of diborane and phosphine, depending on their concentration. As a relevant result, they found that at constant boron concentration compensation occurs by using two different values of phosphine flow. This behavior can be described by a change of formation mechanism involving active dopants, defects and boron-phosphorus complex, that occurs in a different way depending on the dopant concentrations. The two compensation regimes are evidenced also by a different behavior under light soaking. Furthermore they found that photocurrent evolution under illumination is determined by two concurrent mechanisms: activation of dopant species and increase of defect density.

Caputo, D.; De Cesare, G.; Palma, F.; Tucci, M.; Minarini, C.; Terzini, E.

1997-07-01T23:59:59.000Z

111

Defective posttranslational processing activates the tyrosine kinase encoded by the MET proto-oncogene (hepatocyte growth factor receptor).  

Science Journals Connector (OSTI)

...treatment of intact cells. That a defective posttranslational mechanism...compartment is functionally defective in LoVo cells. Since a small...compartment is either incompletely defective or an alternative pathway exists...phosphorylated in the colon car- cinoma line studied. This...

A Mondino; S Giordano; P M Comoglio

1991-12-01T23:59:59.000Z

112

CHARGED POINT DEFECT IN RUTILE TIO2:FROM DEFECT CHARGE DISTRIBUTION TO DEFECT PHONON FREE ENERGY.  

E-Print Network (OSTI)

??The dominant charged point defects in transition metal oxides can change with temperature (T) and oxygen partial pressure (PO2) to control the electrical properties of (more)

Li, Xin

2010-01-01T23:59:59.000Z

113

The effect of magnetic field on bistability in 1D photonic crystal doped by magnetized plasma and coupled nonlinear defects  

SciTech Connect

In this work, we study the defect mode and bistability behavior of 1-D photonic band gap structure with magnetized plasma and coupled nonlinear defects. The transfer matrix method has been employed to investigate the magnetic field effect on defect mode frequency and bistability threshold. The obtained results show that the frequency of defect mode and bistability threshold can be altered, without changing the structure of the photonic multilayer. Therefore, the bistability behavior of the subjected structure in the presence of magnetized plasma can be utilized in manufacturing wide frequency range devices.

Mehdian, H.; Mohammadzahery, Z.; Hasanbeigi, A. [Department of Physics and Institute for Plasma Research, Kharazmi University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)] [Department of Physics and Institute for Plasma Research, Kharazmi University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)

2014-01-15T23:59:59.000Z

114

Mechanical behavior of ultrastructural biocomposites  

E-Print Network (OSTI)

For numerous centuries nature has successfully developed biocomposite materials with detailed multiscale architectures to provide a material stiffness, strength and toughness. One such example is nacre, which is found in ...

Kearney, Cathal (Cathal John)

2006-01-01T23:59:59.000Z

115

Energy Dissipation and Defect Generation for Nanocrystalline...  

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

Dissipation and Defect Generation for Nanocrystalline Silicon Carbide. Energy Dissipation and Defect Generation for Nanocrystalline Silicon Carbide. Abstract: Large-scale molecular...

116

Disk Roughness and Defect Monitoring  

Science Journals Connector (OSTI)

Disk surface monitoring and certification refer to the testing and certification of a disk surface in terms of roughness and defect ... as well as the capability to accommodate a flying slider. It includes glide ...

Gang Sheng; Jizhong He; Shuanlin Duan

2013-01-01T23:59:59.000Z

117

Density of defects and the scaling law of the entanglement entropy in quantum phase transition of one-dimensional spin systems induced by a quench  

SciTech Connect

We have studied quantum phase transition induced by a quench in different one-dimensional spin systems. Our analysis is based on the dynamical mechanism which envisages nonadiabaticity in the vicinity of the critical point. This causes spin fluctuation which leads to the random fluctuation of the Berry phase factor acquired by a spin state when the ground state of the system evolves in a closed path. The two-point correlation of this phase factor is associated with the probability of the formation of defects. In this framework, we have estimated the density of defects produced in several one-dimensional spin chains. At the critical region, the entanglement entropy of a block of L spins with the rest of the system is also estimated which is found to increase logarithmically with L. The dependence on the quench time puts a constraint on the block size L. It is also pointed out that the Lipkin-Meshkov-Glick model in point-splitting regularized form appears as a combination of the XXX model and Ising model with magnetic field in the negative z axis. This unveils the underlying conformal symmetry at criticality which is lost in the sharp point limit. Our analysis shows that the density of defects as well as the scaling behavior of the entanglement entropy follows a universal behavior in all these systems.

Basu, Banasri; Bandyopadhyay, Pratul; Majumdar, Priyadarshi [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700 108 (India); Jyotinagar Bidyasree Niketan H.S. School, 41 Jyotinagar, Kolkata 700 108 (India)

2011-03-15T23:59:59.000Z

118

Polymer defect states modulate open-circuit voltage in bulk-heterojunction solar cells  

SciTech Connect

Defect states influence the operation of organic solar cells altering transport, recombination, and energetic mechanisms. This work investigates how processing conditions induce morphology-related, electrically active defects in the donor polymer of bulk-heterojunction solar cells. Structural order is inferred from absorption and X-ray diffraction data, while defect density is determined from capacitance methods. A correlation is observed between the polymer nanocrystallite size, the defect concentration, and the output voltage. For the case of poly(3-hexylthiophene), processing that promote crystallinity is beneficial for the device performance as it decreases the defect density (energy disorder) that finally enlarges the maximum achievable open-circuit voltage. Defect states within the effective bandgap modulate the downshift of the hole Fermi level upon illumination that in turn establishes the achievable open-circuit voltage.

Ripolles, Teresa S.; Guerrero, Antonio; Garcia-Belmonte, Germ, E-mail: garciag@uji.es [Photovoltaic and Optoelectronic Devices Group, Departament de Fsica, Universitat Jaume I, ES-12071 Castell (Spain)] [Photovoltaic and Optoelectronic Devices Group, Departament de Fsica, Universitat Jaume I, ES-12071 Castell (Spain)

2013-12-09T23:59:59.000Z

119

Compliant mechanism learning toolkit  

E-Print Network (OSTI)

This thesis concerns a toolkit designed to assist in learning the behavior of complaint mechanisms. In the design of complaint mechanisms, increasingly complicated designs behave in ways that are harder to intuitively ...

Allard, Nicholas (Nicholas A.)

2006-01-01T23:59:59.000Z

120

Thermal evolution of boron irradiation induced defects in predoped Si revealed by positron annihilation experiments  

SciTech Connect

The isochronal annealing behavior of high energy (25-72 MeV) boron ion irradiation induced defects in boron-doped silicon is monitored through measurements of positron lifetimes and three distinct defect-evolution stages are identified. The initial boron doping created a defect environment where positrons could sensitively annihilate with the boron electrons, suggesting boron-decorated Si monovacancies as potential trapping sites. The irradiation results in the dissolution of boron from these sites and positrons are then trapped by the empty divacancies of Si. Charge neutralization of divacancies through interaction with boron atoms leads to enhanced positron trapping in the initial stages of isochronal annealing. The divacancies start annealing above 673 K. However, a remarkable defect evolution stage due to the diffusion of the boron atoms beyond their initial depths of penetration is seen above 873 K and it leaves the sample with defects still present even at the highest annealing temperature 1273 K used in this work.

Nambissan, P. M. G.; Bhagwat, P. V.; Kurup, M. B. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

2007-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Graphene defect formation by extreme ultraviolet generated photoelectrons  

E-Print Network (OSTI)

We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy lower than 80 eV. After e-beam irradiation, it is found that the D peak, I(D), appears in the Raman spectrum, indicating defect formation in graphene. The evolution of I(D)/I(G) follows the amorphization trajectory with increasing irradiation dose, indicating that graphene goes through a transformation from microcrystalline to nanocrystalline and then further to amorphous carbon. Further, irradiation of graphene with increased water partial pressure does not significantly change the Raman spectra, which suggests that, in the extremely low energy range, e-beam induced chemical reactions between residual water and graphene is not the dominant mechanism driving defect formation in graphene. Single layer graphene, par...

Gao, A; Bijkerk, F

2014-01-01T23:59:59.000Z

122

Defect-induced magnetism in graphene  

Science Journals Connector (OSTI)

We study from first principles the magnetism in graphene induced by single carbon atom defects. For two types of defects considered in our study, the hydrogen chemisorption defect and the vacancy defect, the itinerant magnetism due to the defect-induced extended states has been observed. Calculated magnetic moments are equal to 1?B per hydrogen chemisorption defect and 1.121.53?B per vacancy defect depending on the defect concentration. The coupling between the magnetic moments is either ferromagnetic or antiferromagnetic, depending on whether the defects correspond to the same or to different hexagonal sublattices of the graphene lattice, respectively. The relevance of itinerant magnetism in graphene to the high-TC magnetic ordering is discussed.

Oleg V. Yazyev and Lothar Helm

2007-03-08T23:59:59.000Z

123

Ozonization at the Vacancy Defect Site of the Single-Walled Carbon Nanotube Lei Vincent Liu, Wei Quan Tian, and Yan Alexander Wang*  

E-Print Network (OSTI)

Ozonization at the Vacancy Defect Site of the Single-Walled Carbon Nanotube Lei Vincent Liu, Wei at the vacancy defect site of the single-walled carbon nanotube has been studied by static quantum mechanics approach. Among five different reaction pathways at the vacancy defect, the reaction involving

Wang, Yan Alexander

124

Energetics of Defects on Graphene through Fluorination  

SciTech Connect

In the present study, we used FGS[5] as the substrate and implemented low temperature (<=150 oC) direct fluorination on graphene sheets. The fluorine content has been modulated to investigate the formation mechanism of different functional groups such as C-F, CF2, O-CF2 and (C=O)F during the fluorination process. The detailed structure and chemical bonds were simulated theoretically and quantified experimentally by using density function theory (DFT) calculations and NMR techniques, respectively. The adjustable power/energy ratio from fluorinated graphene as cathode for primary lithium batteries is also discussed. From a combination of NMR spectroscopy and theoretical calculation, we conclude that the topological defects without oxygen containing groups provide most of the reactive sites to react with F. FGS also contain a small number of COOH groups which contribute for the fluorination reaction. Hydroxyl or epoxy groups contribute to another fraction of the reaction products.

Xiao, Jie; Meduri, Praveen; Chen, Honghao; Wang, Zhiguo; Gao, Fei; Hu, Jian Z.; Feng, Ju; Hu, Mary Y.; Dai, Sheng; Brown, Suree; Adcock, Jamie L.; Deng, Zhiqun; Liu, Jun; Graff, Gordon L.; Aksay, Ilhan A.; Zhang, Jiguang

2014-04-01T23:59:59.000Z

125

High-field critical current enhancement by irradiation induced correlated and random defects in (Ba{sub 0.6}K{sub 0.4})Fe{sub 2}As{sub 2}  

SciTech Connect

Mixed pinning landscapes in superconductors are emerging as an effective strategy to achieve high critical currents in high, applied magnetic fields. Here, we use heavy-ion and proton irradiation to create correlated and point defects to explore the vortex pinning behavior of each and combined constituent defects in the iron-based superconductor Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2} and find that the pinning mechanisms are non-additive. The major effect of p-irradiation in mixed pinning landscapes is the generation of field-independent critical currents in very high fields. At 7 T ? c and 5 K, the critical current density exceeds 5 MA/cm{sup 2}.

Kihlstrom, K. J.; Crabtree, G. W. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Fang, L.; Jia, Y.; Shen, B.; Koshelev, A. E.; Welp, U.; Kwok, W.-K. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kayani, A. [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008 (United States)] [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008 (United States); Zhu, S. F. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Wen, H.-H. [National Laboratory of Solid State Microstructures, Department of Physics, Center for Superconducting Physics and Materials, Nanjing University, Nanjing 210093 (China)] [National Laboratory of Solid State Microstructures, Department of Physics, Center for Superconducting Physics and Materials, Nanjing University, Nanjing 210093 (China)

2013-11-11T23:59:59.000Z

126

Process for rapid detection of fratricidal defects on optics using Linescan Phase Differential Imaging  

SciTech Connect

Phase-defects on optics used in high-power lasers can cause light intensification leading to laser-induced damage of downstream optics. We introduce Linescan Phase Differential Imaging (LPDI), a large-area dark-field imaging technique able to identify phase-defects in the bulk or surface of large-aperture optics with a 67 second scan-time. Potential phase-defects in the LPDI images are indentified by an image analysis code and measured with a Phase Shifting Diffraction Interferometer (PSDI). The PSDI data is used to calculate the defects potential for downstream damage using an empirical laser-damage model that incorporates a laser propagation code. A ray tracing model of LPDI was developed to enhance our understanding of its phase-defect detection mechanism and reveal limitations.

Ravizza, F L; Nostrand, M C; Kegelmeyer, L M; Hawley, R A; Johnson, M A

2009-11-05T23:59:59.000Z

127

Perfect preferential orientation of nitrogen-vacancy defects in a synthetic diamond sample  

SciTech Connect

We show that the orientation of nitrogen-vacancy (NV) defects in diamond can be efficiently controlled through chemical vapor deposition growth on a (111)-oriented diamond substrate. More precisely, we demonstrate that spontaneously generated NV defects are oriented with a ?97% probability along the [111] axis, corresponding to the most appealing orientation among the four possible crystallographic axes. Such a nearly perfect preferential orientation is explained by analyzing the diamond growth mechanism on a (111)-oriented substrate and could be extended to other types of defects. This work is a significant step towards the design of optimized diamond samples for quantum information and sensing applications.

Lesik, M.; Roch, J.-F. [Laboratoire Aim Cotton, CNRS, Universit Paris-Sud and Ecole Normale Suprieure de Cachan, 91405 Orsay (France); Tetienne, J.-P.; Jacques, V., E-mail: vjacques@ens-cachan.fr [Laboratoire Aim Cotton, CNRS, Universit Paris-Sud and Ecole Normale Suprieure de Cachan, 91405 Orsay (France); Laboratoire de Photonique Quantique et Molculaire, Ecole Normale Suprieure de Cachan and CNRS UMR 8537, 94235 Cachan (France); Tallaire, A., E-mail: alexandre.tallaire@lspm.cnrs.fr; Achard, J.; Mille, V.; Gicquel, A. [Laboratoire des Sciences des Procds et des Matriaux, CNRS and Universit Paris 13, 93340 Villetaneuse (France)

2014-03-17T23:59:59.000Z

128

Studies on Mechanical Properties, Thermal Degradation, and Combustion Behaviors of Poly(1,4-butylene terephthalate)/Glass Fiber/Cerium Hypophosphite Composites  

Science Journals Connector (OSTI)

For the GRPBT composite with 15 wt % of CHP, the storage modulus value at 30 C was 3 times that of GRPBT. ... Yang, W.; Hu, Y.; Tai, Q. L.; Lu, H. D.; Song, L.; Yuen, R. K. K.Fire and mechanical performance of nanoclay reinforced glass-fiber/PBT composites containing aluminum hypophosphite particles Composites, Part A 2011, 42, 794 800 ...

Wei Yang; Ningning Hong; Lei Song; Yuan Hu; Richard K. K. Yuen; Xinglong Gong

2012-06-04T23:59:59.000Z

129

Analysis of defect generation in Ti6Al4V parts made using powder bed fusion additive manufacturing processes  

Science Journals Connector (OSTI)

Abstract Ti6Al4V parts made using additive manufacturing processes such as selective laser melting (SLM) and electron beam melting (EBM) are subject to the inclusion of defects. This study purposely fabricated Ti6Al4V samples with defects by varying process parameters from the factory default settings in both SLM and EBM systems. Process parameters are classified according to their tendency to create certain types of porosity. Finally, defect characteristics are discussed with respect to defect generation mechanisms; and effective process windows for SLM and EBM system are discussed.

Haijun Gong; Khalid Rafi; Hengfeng Gu; Thomas Starr; Brent Stucker

2014-01-01T23:59:59.000Z

130

Defective fullerenes and nanotubes as molecular magnets: An ab initio study Yong-Hyun Kim,* Jin Choi, and K. J. Chang  

E-Print Network (OSTI)

Defective fullerenes and nanotubes as molecular magnets: An ab initio study Yong-Hyun Kim,* Jin ordering are not well es- tablished, the experimental evidence for ferromagnetic car- bon nanostructures in the magnetic behavior, and suggested a possible link between magnetism and defects in the pure carbon network

131

Exploring the eddy current excitation invariance to infer about defect characteristics  

SciTech Connect

This paper explores the excitation probe excitation field invariance when the eddy current method is applied to detect, localize and characterize material defects in conductive nonmagnetic media. The cases relative to rotational symmetry in circular solenoidal probes and translation symmetry in constant field probes are presented. The experimental data shows that this theoretical treatment is useful to preview the behavior of these probes.

Ribeiro, A. Lopes; Ramos, H. G. [I and M Group, Instituto de Telecomunicacoes, Lisboa, Portugal Instituto Superior Tecnico, DEEC, Lisboa (Portugal)

2011-06-23T23:59:59.000Z

132

Space-time defects and teleparallelism  

E-Print Network (OSTI)

We consider the class of space-time defects investigated by Puntigam and Soleng. These defects describe space-time dislocations and disclinations (cosmic strings), and are in close correspondence to the actual defects that arise in crystals and metals. It is known that in such materials dislocations and disclinations require a small and large amount of energy, respectively, to be created. The present analysis is carried out in the context of the teleparallel equivalent of general relativity (TEGR). We evaluate the gravitational energy of these space-time defects in the framework of the TEGR and find that there is an analogy between defects in space-time and in continuum material systems: the total gravitational energy of space-time dislocations and disclinations (considered as idealized defects) is zero and infinit, respectively.

J. W. Maluf; A. Goya

2001-10-24T23:59:59.000Z

133

Predicting the equilibria of point defects in zirconium oxide : a route to understand the corrosion and hydrogen pickup of zirconium alloys  

E-Print Network (OSTI)

The performance of zirconium alloys in nuclear reactors is compromised by corrosion and hydrogen pickup. The thermodynamics and kinetics of these two processes are governed by the behavior of point defects in the ZrO? layer ...

Youssef, Mostafa Youssef Mahmoud

2014-01-01T23:59:59.000Z

134

EUV actinic defect inspection and defect printability at the sub-32 nm half pitch  

E-Print Network (OSTI)

at the Sub-32 run Half-pitch Sungmin Huha, Patrick Kearneya,below the 32 nm half-pitch node. Phase defect printabilityfor the sub-32 nm half-pitch technology node. Defect

Huh, Sungmin

2010-01-01T23:59:59.000Z

135

Defect formation by pristine indenter at the initial stage of nanoindentation  

SciTech Connect

Nano-indentation is a sophisticated method to characterize mechanical properties of materials. This method samples a very small amount of material during each indentation. Therefore, this method is extremely useful to measure mechanical properties of nano-materials. The measurements using nanoindentation is very sensitive to the surface topology of the indenter and the indenting surfaces. The mechanisms involved in the entire process of nanoindentation require an atomic level understanding of the interplay between the indenter and the substrate. In this paper, we have used atomistic simulation methods with empirical potentials to investigate the effect of various types of pristine indenter on the defect nucleation and growth. Using molecular dynamics simulations, we have predicted the load-depth curve for conical, vickers, and sperical tip. The results are analyzed based on the coherency between the indenter tip and substrate surface for a fixed depth of 20?. The depth of defect nucleation and growth is observed to be dependent on the tip geometry. A tip with larger apex angle nucleates defects at a shallower depth. However, the type of defect generated is dependent on the crystalline orientation of the tip and substrate. For coherent systems, prismatic loops were generated, which released into the substrate along the close-packed directions with continued indentation. For incoherent systems, pyramidal shaped dislocation junctions formed in the FCC systems and disordered atomic clusters formed in the BCC systems. These defect nucleation and growth process provide the atomistic mechanisms responsible for the observed load-depth response during nanoindentation.

Chen, I-Hsien [Department of Materials Science and Engineering, National Cheng Kung University, Tainan City, 70101 Taiwan (China); Hsiao, Chun-I [Department of Materials Science and Engineering, National Cheng Kung University, Tainan City, 70101 Taiwan (China); Promotion Center for Global Materials Research, National Cheng Kung University, Tainan City 70101, Taiwan (China); Behera, Rakesh K. [Nuclear and Radiological Engineering Program, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Hsu, Wen-Dung, E-mail: wendung@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan City, 70101 Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan City 70101, Taiwan (China); Promotion Center for Global Materials Research, National Cheng Kung University, Tainan City 70101, Taiwan (China); Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan City 70101 Taiwan (China)

2013-12-07T23:59:59.000Z

136

Programmable Mechanical Metamaterials  

E-Print Network (OSTI)

We create mechanical metamaterials whose response to uniaxial compression can be programmed by lateral confinement, allowing monotonic, non-monotonic and hysteretic behavior. These functionalities arise from a broken rotational symmetry which causes highly nonlinear coupling of deformations along the two primary axes of these metamaterials. We introduce a soft mechanism model which captures the programmable mechanics, and outline a general design strategy for confined mechanical metamaterials. Finally, we show how inhomogeneous confinement can be explored to create multi stability and giant hysteresis.

Bastiaan Florijn; Corentin Coulais; Martin van Hecke

2014-07-17T23:59:59.000Z

137

Energy levels and decoherence properties of single electron and nuclear spins in a defect center in diamond  

E-Print Network (OSTI)

The coherent behavior of the single electron and single nuclear spins of a defect center in diamond and a 13C nucleus in its vicinity, respectively, are investigated. The energy levels associated with the hyperfine coupling of the electron spin of the defect center to the 13C nuclear spin are analyzed. Methods of magnetic resonance together with optical readout of single defect centers have been applied in order to observe the coherent dynamics of the electron and nuclear spins. Long coherence times, in the order of microseconds for electron spins and tens of microseconds for nuclear spins, recommend the studied system as a good experimental approach for implementing a 2-qubit gate.

I. Popa; T. Gaebel; M. Domhan; C. Wittmann; F. Jelezko; J. Wrachtrup

2004-09-12T23:59:59.000Z

138

A chemical bonding model for photo-induced defects in hydrogenated amorphous silicon (a-Si:H): Intrinsic and extrinsic reaction pathways  

SciTech Connect

In device grade a-Si:H photo- or light-induced defect generation is an intrinsic effect for impurity concentrations of oxygen and nitrogen below about 10{sup 19} to 10{sup 20} cm{sup {minus}3}; however, at higher concentrations it increases with increasing impurity content. Charged defect configurations are identified by empirical chemistry and are studied by ab initio calculations. This paper addresses: (1) the chemical stability of charged defects; (2) the reaction pathways for defect metastability; and (3) the transition between extrinsic and intrinsic behavior.

Lucovsky, G.; Yang, H.

1997-07-01T23:59:59.000Z

139

Impact of point defects on electronic structure in Y2Ti2O7  

SciTech Connect

With many technologies and applications downscaling to nanometer dimensions, the influence of single point defects on electronic structure has shown increasingly profound impact on optical and electrical properties, and advancing fundamental understanding is critical to defect engineering and control of materials properties. In the present study, first-principles calculations based on density functional theory (DFT) are carried out to study the effects of Ti point defects on the electronic structure of Y2Ti2O7. In the literature, it has been demonstrated that conventional DFT tends to produce delocalized holes and electrons in defective oxide materials due to insufficient cancellation of the self-interaction energy and underestimation of the band gap, which results in an incorrect description of the electronic structure of the system. In an effort to better understand the accuracy of DFT in describing the behavior of Y2Ti2O7 with point defects, the calculated results obtained from using DFT and DFT+U methods are compared, including the geometrical distortion, the localization of the defect states and the position of the defect levels in the band gap. Using DFT, distorted geometries around the Ti vacancy and interstitial are found, along with localized oxygen holes and Ti electrons, both of which compare well with the DFT+U results, suggesting that the conventional DFT can be used to describe the localization of the Ti defects in Y2Ti2O7. One major difference in the DFT and DFT+U calculations is the energy position of the defect levels, for which DFT+U results in the states positioned deep in the band gap. Since the DFT+U method suffers from the dependence of the results on the empirical parameter U and no experimental results on the energy position of the defect states are available to tune this U value, care must be taken in applying DFT+U to electronic structure calculations of Y2Ti2O7 with point defects. Based on the DFT method, the most preferred charge state is determined by the formation energies for charged point defects. Moving the Fermi level across the band gap has slight effects on the charge state, and the Ti vacancy and interstitial are found to be in -4 and +4 charge states, respectively.

Xiao, Haiyan [University of Tennessee, Knoxville (UTK); Zhang, Yanwen [ORNL; Weber, William J [ORNL

2012-01-01T23:59:59.000Z

140

Impact of Point Defects on Electronic Structure in Y?Ti?O?  

SciTech Connect

With many technologies and applications downscaling to nanometer dimensions, the influence of single point defects on electronic structure has shown an increasingly profound impact on optical and electrical properties, and advancing fundamental understanding is critical to defect engineering and control of materials properties. In the present study, first-principles calculations based on density functional theory (DFT) are carried out to study the effects of Ti point defects on the electronic structure of Y?Ti?O?. In the literature, it has been demonstrated that conventional DFT tends to produce delocalized holes and electrons in defective oxide materials due to insufficient cancellation of the self-interaction energy and underestimation of the band gap, which results in an incorrect description of the electronic structure of the system. In an effort to better understand the accuracy of DFT in describing the behavior of Y?Ti?O? with point defects, the calculated results obtained from DFT and DFT+U methods are compared, including the geometrical distortion, the localization of the defect states and the position of the defect levels in the band gap. Using DFT, distorted geometries around the Ti vacancy and interstitial are found, along with localized oxygen holes and Ti electrons, both of which compare well with the DFT+U results, suggesting that the conventional DFT can be used to describe the localization of the Ti defects in Y?Ti?O?. One major difference in the DFT and DFT+U calculations is the energy position of the defect levels, for which DFT+U results in the states positioned deep in the band gap. Since the DFT+U method suffers from the dependence of the results on the empirical parameter U and no experimental results on the energy position of the defect states are available to tune this U value, care must be taken in applying DFT+U to electronic structure calculations of Y?Ti?O? with point defects. Based on the DFT method, the most preferred charge state is determined by the formation energies for charged point defects. Moving the Fermi level across the band gap has slight effects on the charge state, and the Ti vacancy and interstitial are found to be in 24 and +4 charge states, respectively.

Xiao, Haiyan Y.; Zhang, Yanwen; Weber, William J.

2012-06-13T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Analysis, Simulation and Prediction of Cosmetic Defects on Automotive External Panel  

Science Journals Connector (OSTI)

The first feeling of quality for a vehicle is linked to its perfect appearance. This has a major impact on the reputation of a car manufacturer. Cosmetic defects are thus more and more taken into account in the process design. Qualifying a part as good or bad from the cosmetic point of view is mainly subjective: the part aspect is considered acceptable if no defect is visible on the vehicle by the final customer. Cosmetic defects that appear during sheet metal forming are checked by visual inspection in light inspection rooms stoning or with optical or mechanical sensors or feelers. A lack of cosmetic defect prediction before part production leads to the need for corrective actions production delays and generates additional costs.

A. Le Port; S. Thuillier; C. Borot; J. Charbonneaux; Aethra Automotive Systems

2011-01-01T23:59:59.000Z

142

Physical process Mechanical mechanisms  

E-Print Network (OSTI)

1 Physical process Generation · Mechanical mechanisms F = m·a · Electric/Magnetic mechanisms F ­ Quadrupoles......shear stress fluctuations ­ High order poles...... phys. interpretation difficult Governing

Berlin,Technische Universität

143

Polycrystal model of the mechanical behavior of a Mo-TiC30vol.% metal-ceramic composite using a 3D microstructure map obtained by a dual beam FIB-SEM  

E-Print Network (OSTI)

The mechanical behavior of a Mo-TiC30 vol.% ceramic-metal composite was investigated over a large temperature range (25^{\\circ}C to 700^{\\circ}C). High-energy X-ray tomography was used to reveal the percolation of the hard titanium carbide phase through the composite. Using a polycrystal approach for a two-phase material, finite element simulations were performed on a real 3D aggregate of the material. The 3D microstructure, used as starting configuration for the predictions, was obtained by serial-sectioning in a dual beam Focused Ion Beam (FIB)-Scanning Electron Microscope (SEM) coupled to an Electron Back Scattering Diffraction system (3D EBSD, EBSD tomography). The 3D aggregate consists of a molybdenum matrix and a percolating TiC skeleton. As most BCC metals, the molybdenum matrix phase is characterized by a change in the plasticity mechanisms with temperature. We used a polycrystal model for the BCC material, which was extended to two phases (TiC and Mo). The model parameters of the matrix were determin...

Cdat, Denis; Rey, Colette; Raabe, Dierk; 10.1016/actamat.2011.11.55

2013-01-01T23:59:59.000Z

144

Kinetics of light induced defect creation in organic solar cells  

Science Journals Connector (OSTI)

The kinetics of light-induced recombination centers in bulk heterojunction organic solar cells are measured as a function of exposure time intensity and the illumination photon energy. The density of induced centers increases with exposure but stabilizes partially due to self-annealing. UV exposure is roughly 50 times more effective for defect creation than white light or yellow-filtered white light. Light-induced breaking of C-H bonds to create H-related localized states is proposed as the underlying mechanism.

R. A. Street; D. M. Davies

2013-01-01T23:59:59.000Z

145

Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity  

SciTech Connect

A computer program which was used to simulate and analyze the thermal behaviors of SRF cavities has been developed at Jefferson Lab using C++ code. This code was also used to verify the quench initiation due to geometrical defects in high magnetic field region of SRF cavities. We built a CEBAF single cell cavity with 4 artificial defects near equator, and this cavity has been tested with T-mapping. The preheating behavior and quench initiation analysis of this cavity will be presented here using the computer program.

J. Dai, K. Zhao, G.V. Eremeev, R.L. Geng, A.D. Palczewski; Dai, J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, A. D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Eremeev, G. V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Geng, R. L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhao, K. [Institute of Heavy Ion Physics, Peking University, Beijing (China)

2011-07-01T23:59:59.000Z

146

Coulomb screening in graphene with topological defects  

E-Print Network (OSTI)

We analyze the screening of an external Coulomb charge in gapless graphene cone, which is taken as a prototype of a topological defect. In the subcritical regime, the induced charge is calculated using both the Green's function and the Friedel sum rule. The dependence of the polarization charge on the Coulomb strength obtained from the Green's function clearly shows the effect of the conical defect and indicates that the critical charge itself depends on the sample topology. Similar analysis using the Friedel sum rule indicates that the two results agree for low values of the Coulomb charge but differ for the higher strengths, especially in the presence of the conical defect. For a given subcritical charge, the transport cross-section has a higher value in the presence of the conical defect. In the supercritical regime we show that the coefficient of the power law tail of polarization charge density can be expressed as a summation of functions which vary log periodically with the distance from the Coulomb impurity. The period of variation depends on the conical defect. In the presence of the conical defect, the Fano resonances begin to appear in the transport cross-section for a lower value of the Coulomb charge. For both sub and supercritical regime we derive the dependence of LDOS on the conical defect. The effects of generalized boundary condition on the physical observables are also discussed.

Baishali Chakraborty; Kumar S. Gupta; Siddhartha Sen

2015-02-16T23:59:59.000Z

147

Analysis of a Defected Dissimilar Metal Weld in a PWR Power Plant  

SciTech Connect

During the refueling outage 2000, inspections of the RC-loops of one of the Ringhals PWR-units, Ringhals 4, indicated surface breaking defects in the axial direction of the piping in a dissimilar weld between the Low alloy steel nozzle and the stainless safe end in the hot leg. In addition some indications were found that there were embedded defects in the weld material. These defects were judged as being insignificant to the structural integrity. The welds were inspected in 1993 with the result that no significant indications were found. The weld it self is a double U weld, where the thickness of the material is ideally 79,5 mm. Its is constructed by Inconel 182 weld material. At the nozzle a buttering was applied, also by Inconel 182. The In-service inspection, ISI, of the object indicated four axial defects, 9-16 mm deep. During fabrication, the areas where the defects are found were repaired at least three times, onto a maximum depth of 32 mm. To evaluate the defects, 6 boat samples from the four axial defects were cut from the perimeter and shipped to the hot-cell laboratory for further examination. This examination revealed that the two deep defects had been under sized by the ISI outside the requirement set by the inspection tolerances, while the two shallow defects were over sized, but within the tolerances of the detection system. When studying the safety case it became evident that there were several missing elements in the way this problems is handled with respect to the Swedish safety evaluation code. Among these the most notable at the beginning was the absence of reliable fracture mechanical data such as crack growth laws and fracture toughness at elevated temperature. Both these questions were handled by the project. The fracture mechanical evaluation has focused on a fit for service principal. Thus defects both in the unaffected zones and the disturbed zones, boat sample cutouts, of the weld have been analyzed. With reference to the Swedish safety evaluation system in accordance to the regulatory demands, a safety evaluation was performed using the R6-method. The failure assessment diagram is modified by the addition of the ASME XI safety factors both for limit load analysis and fracture assessment. This results in a very high conservatism since the secondary stresses such as residual stresses are high in the area. In order to quantify this effect an analysis in accordance to ASME IWB-3640, App. C was performed. This analysis provides the decision-makers with a sensitivity study; important to have to value the real risk of any missed defects in the area. (authors)

Efsing, P. [Barseback Kraft AB, P.O. Box 524, Loddekopinge SE-246 25 (Sweden); Lagerstrom, J. [Vattenfall AB, Ringhals, 430 22 Vaeroebacka (Sweden)

2002-07-01T23:59:59.000Z

148

Irradiation-induced defect clustering and amorphization in silicon...  

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

Irradiation-induced defect clustering and amorphization in silicon carbide. Irradiation-induced defect clustering and amorphization in silicon carbide. Abstract: Previous computer...

149

Modification of Defect Structures in Graphene by Electron Irradiation...  

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

Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations. Modification of Defect Structures in Graphene by Electron...

150

Exploring the interaction between lithium ion and defective graphene...  

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

Exploring the interaction between lithium ion and defective graphene surface using dispersion corrected DFT studies. Exploring the interaction between lithium ion and defective...

151

Energetics of Defects on Graphene through Fluorination. | EMSL  

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

Defects on Graphene through Fluorination. Energetics of Defects on Graphene through Fluorination. Abstract: In the present study, we used FGS5 as the substrate and implemented...

152

Cation Defects and Conductivity in Transparent Oxides  

SciTech Connect

High quality doped zinc oxide and mixed transition metal spinel oxide films have been deposited by means of sputter deposition from metal and metal oxide targets, and by spin casting from aqueous or alcoholic precursor solutions. Deposition conditions and post-deposition processing are found to alter cation oxidation states and their distributions in both oxide materials resulting in marked changes to both optical transmission and electrical response. For ZnO, partial reduction of the neat or doped material by hydrogen treatment of the heated film or by electrochemical processing renders the oxide n-type conducting. Continued reduction was found to diminish conductivity. In contrast, oxidation of the infrared transparent p-type spinel conductors typified by NiCo2O4 was found to increase conductivity. The disparate behavior of these two materials is caused in part by the sign of the charge carrier and by the existence of two different charge transport mechanisms that are identified as free carrier conduction and polaron hopping. While much work has been reported concerning structure/property relationships in the free carrier conducting oxides, there is a significantly smaller body of information on transparent polaron conductors. In this paper, we identify key parameters that promote conductivity in mixed metal spinel oxides and compare their behavior with that of the free carrier TCOs.

Exarhos, Gregory J.; Windisch, Charles F.; Ferris, Kim F.; Owings, Robert R.

2007-10-24T23:59:59.000Z

153

Energy dependence of defects in a-Si:H solar cells during degradation and annealing processes  

SciTech Connect

In this work the authors report on the effect of current-induced degradation and annealing on p-i-n amorphous silicon solar cells. Current-voltage curves and capacitance measurements under forward bias have been used to monitor the current-induced changes as a function of time. They found that the recovery rate increases with the annealing current, while the stabilized value of efficiency decreases. Comparison of short circuit current and capacitance evolution suggests that defect kinetics in the electronic gap occurs in a different way during degradation and annealing. This behavior can be modeled assuming a faster annealing of defects closest to the extended band and a slower annealing of mid-gap defects.

Caputo, D.; Lemmi, F.; Palma, F.

1997-07-01T23:59:59.000Z

154

Generalized quantum defect methods in quantum chemistry  

E-Print Network (OSTI)

The reaction matrix of multichannel quantum defect theory, K, gives a complete picture of the electronic structure and the electron - nuclear dynamics for a molecule. The reaction matrix can be used to examine both bound ...

Altunata, Serhan

2006-01-01T23:59:59.000Z

155

Sleeve installations speed pipeline defect repair  

SciTech Connect

Repairing defects in pipelines can be a major challenge for pipeline companies or contractors. To reduce cost and eliminate unscheduled shut downs, pipeline operating companies have adopted ``in-service`` repair methods to restore overall integrity of the pipeline without taking it out of service. Interprovincial Pipe Line Co. has undertaken an aggressive approach to this ``in-service`` repair method by using a developed sleeving system for repairing leaking and non-leaking defects. A structural reinforcement sleeve consists of two non-fillet welded collars (one on each side of the defect) and a full encirclement sleeve welded on top of these collars. The annular space between the pipe and sleeve is filled with a hardenable, non-shrinking epoxy. Three different pressure vessel sleeves can be used for repairing certain defects. They can be used in combination with the pre-stressed sleeve or for independent repairs. This paper reviews the performance and installation of these sleeves.

Friedrich, J.; Smith, J.

1995-12-01T23:59:59.000Z

156

INNOVATIVE EDDY CURRENT PROBE FOR MICRO DEFECTS  

SciTech Connect

This paper reports the development of an innovative eddy current (EC) probe, and its application to micro-defects on the root of the Friction Stir Welding (FSW). The new EC probe presents innovative concept issues, allowing 3D induced current in the material, and a lift-off independence. Validation experiments were performed on aluminium alloys processed by FSW. The results clearly show that the new EC probe is able to detect and sizing surface defects about 60 microns depth.

Santos, Telmo G.; Vilaca, Pedro; Quintino, Luisa [IDMEC, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Santos, Jorge dos [GKSS, Max-Planck-Street 1, D-21502 Geesthacht (Germany); Rosado, Luis [IST, UTL, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)

2010-02-22T23:59:59.000Z

157

PARTIAL DISCHARGE TESTING OF DEFECTIVE THREE-PHASE PILC CABLE UNDER RATED CONDITIONS  

E-Print Network (OSTI)

PARTIAL DISCHARGE TESTING OF DEFECTIVE THREE-PHASE PILC CABLE UNDER RATED CONDITIONS J. A. Hunter 1 lifespan. An increase in the failure rates of paper insulated lead covered (PILC) cables that make up is to document the effects of mechanical stress on the generation of partial discharge (PD) for cables of PILC

Southampton, University of

158

Atomic-scale electron-beam sculpting of defect-free graphene nanostructures  

E-Print Network (OSTI)

Atomic-scale electron-beam sculpting of defect-free graphene nanostructures Bo Song, Grégory F.w.zandbergen@tudelft.nl ABSTRACT. In order to harvest the many promising properties of graphene in (electronic) applications a temperature-dependent self-repair mechanism allowing damage-free atomic-scale sculpting of graphene using

Dekker, Cees

159

Dinosaur behavior  

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

Dinosaur behavior Dinosaur behavior Name: kevv Status: N/A Age: N/A Location: N/A Country: N/A Date: Around 1993 Question: Did the movie Jurassic Park accurately reflect the known behavior of dinosaurs? Replies: Well, since we do not have an accurate record of that time period (Man showed up about ten million years after T-rex thundered across the plains of Antarctica *grin*) so we cannot say for certain WHAT the dinosaurs did. However, since they were wild animals, we can extrapolate from their modern contemporaries and from our knowledge of their individual anatomies what kind of behaviors they exhibited. A predator with large claws probably hunts by slashing and by piercing and holding on to prey. An herbivore with large spikes growing on its tail probably used them to fend off attackers like a spiked club -- I do not think it was much of a fashion statement

160

Automated laser scatter detection of surface and subsurface defects in Si{sub 3}N{sub 4} components  

SciTech Connect

Silicon Nitride (Si{sub 3}N{sub 4}) ceramics are currently a primary material of choice to replace conventional materials in many structural applications because of their oxidation resistance and desirable mechanical and thermal properties at elevated temperatures. However, surface or near-subsurface defects, such as cracks, voids, or inclusions, significantly affect component lifetimes. These defects are currently difficult to detect, so a technique is desired for the rapid automated detection and quantification of both surface and subsurface defects. To address this issue, the authors have developed an automated system based on the detection of scattered laser light which provides a 2-D map of surface or subsurface defects. This system has been used for the analysis of flexure bars and button-head tensile rods of several Si{sub 3}N{sub 4} materials. Mechanical properties of these bars have also been determined and compared with the laser scatter results.

Steckenrider, J.S. [Argonne National Lab., IL (United States). Energy Technology Div.

1995-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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.


161

Effects of boron-nitride substrates on Stone-Wales defect formation in graphene: An ab initio molecular dynamics study  

SciTech Connect

Ab initio molecular dynamics simulations are performed to investigate the effects of a boron nitride (BN) substrate on Stone-Wales (SW) defect formation and recovery in graphene. It is found that SW defects can be created by an off-plane recoil atom that interacts with the BN substrate. A mechanism with complete bond breakage for formation of SW defects in suspended graphene is also revealed for recoils at large displacement angles. In addition, further irradiation can result in recovery of the SW defects through a bond rotation mechanism in both graphene and graphene/BN, and the substrate has little effect on the recovery process. This study indicates that the BN substrate enhances the irradiation resistance of graphene.

Jin, K.; Xiao, H. Y. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Zhang, Y. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Weber, W. J., E-mail: wjweber@utk.edu [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2014-05-19T23:59:59.000Z

162

Electrical characterization of defects introduced in n-Ge during electron beam deposition or exposure  

SciTech Connect

Schottky barrier diodes prepared by electron beam deposition (EBD) on Sb-doped n-type Ge were characterized using deep level transient spectroscopy (DLTS). Pt EBD diodes manufactured with forming gas in the chamber had two defects, E{sub 0.28} and E{sub 0.31}, which were not previously observed after EBD. By shielding the samples mechanically during EBD, superior diodes were produced with no measureable deep levels, establishing that energetic ions created in the electron beam path were responsible for the majority of defects observed in the unshielded sample. Ge samples that were first exposed to the conditions of EBD, without metal deposition (called electron beam exposure herein), introduced a number of new defects not seen after EBD with only the E-center being common to both processes. Substantial differences were noted when these DLTS spectra were compared to those obtained using diodes irradiated by MeV electrons or alpha particles indicating that very different defect creation mechanisms are at play when too little energy is available to form Frenkel pairs. These observations suggest that when EBD ions and energetic particles collide with the sample surface, inducing intrinsic non-localised lattice excitations, they modify defects deeper in the semiconductor thus rendering them observable.

Coelho, S. M. M.; Auret, F. D.; Janse van Rensburg, P. J.; Nel, J. M. [Department of Physics, University of Pretoria, Private Bag X20, Hatfield, 0028 (South Africa)

2013-11-07T23:59:59.000Z

163

Neuronal and behavioral mechanisms of Gestalt perception .  

E-Print Network (OSTI)

??Principles of Gestalt perception have fundamentally influenced our understanding of visual cognition. In the past century, Gestalt psychologists postulated that the human brain determines single (more)

Rennig, Johannes

2015-01-01T23:59:59.000Z

164

PAH Sorption Mechanism and Partitioning Behavior in  

E-Print Network (OSTI)

. Introduction Prior to the widespread distribution of natural gas, manu- factured gas from coke, coal, and oil. In the eastern United States, where coal was plentiful, gas was derived from coal or coke. Along the West Coast, because of the availability of oil and the expense in transporting coal or coke to this region, gas

Zare, Richard N.

165

Simulation of localized barrier defects in resonant tunneling diodes  

E-Print Network (OSTI)

. . . . 30 14 PVCR versus left energy and position for right defect atxt = 2152 A and Et =-0. 1 eV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 15 16 17 PVCR versus left defect position and energy for the right defect at xt... = 2152 A and Et = 0. 15 eV. . . . . . . . PVCR versus left defect position and energy for the right defect at xt = 2142 A and Et = 0. 15 eV. . . . . . . PVCR versus left defect position and energy for the right defect at x I = 2122 A and Et = 0 e...

Stoneberg, Jason Neal

1995-01-01T23:59:59.000Z

166

Symmetry, Defects, and Gauging of Topological Phases  

E-Print Network (OSTI)

We examine the interplay of symmetry and topological order in $2+1$ dimensional topological phases of matter. We present a definition of the \\it topological symmetry \\rm group, which characterizes the symmetry of the emergent topological quantum numbers of a topological phase $\\mathcal{C}$, and describe its relation with the microscopic symmetry of the underlying physical system. We derive a general framework to classify symmetry fractionalization in topological phases, including non-Abelian phases and the possibility that the symmetries permute the quasiparticle types. We develop a theory of extrinsic defects (fluxes) associated with elements of the symmetry group, which provides a general classification of symmetry-enriched topological phases derived from a topological phase of matter $\\mathcal{C}$ with (on-site) symmetry group $G$. The algebraic theory of the defects, known as a $G$-crossed braided tensory category $\\mathcal{C}_{G}^{\\times}$, allows one to compute many properties, such as the number of topologically distinct types of defects associated with each group element, their fusion rules, quantum dimensions, zero modes, braiding exchange transformations, a generalized Verlinde formula for the defects, and modular transformations of the $G$-crossed extensions of topological phases. We also examine the promotion of the global symmetry to a local gauge invariance, wherein the extrinsic $G$-defects are turned into deconfined quasiparticle excitations, which results in a different topological phase $\\mathcal{C}/G$. A number of instructive and/or physically relevant examples are studied in detail.

Maissam Barkeshli; Parsa Bonderson; Meng Cheng; Zhenghan Wang

2014-10-16T23:59:59.000Z

167

Comment on the article ``UCN anomalous losses and the UCN capture cross section on material defects'' by A. Serebrov et al  

E-Print Network (OSTI)

We present correct solution of the problem about a scattering of the neutron on a point-like defect existing in a medium and show that this mechanism cannot explain anomalous losses of UCN in storage bottles.

A. L. Barabanov; K. V. Protasov

2005-07-08T23:59:59.000Z

168

The effects of fastener hole defects  

E-Print Network (OSTI)

) August 1991 ABSTRACT The Effects of Fastener Hole Defects. (August 1991) Scot D. Andrews, B. S. , Texas A8rM University Chair of Advisory Committee: Dr. Orden O. Ochoa The influence of drilling-induced defects, such as delamination, on the fatigue... Of Delaminated Zone Elements . . Figure 34. Enlarged View Of Area Near Hole 58 59 61 Page Figure 35. Example Finite Element Mesh Figure 36. Selected Elements For Stress Distribution Graphs . . Figure 37. Example Of o? Stress Distribution For 18 Ply Tape...

Andrews, Scot D.

2012-06-07T23:59:59.000Z

169

E-Print Network 3.0 - arterial wall mechanics Sample Search Results  

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

mechanics Page: << < 1 2 3 4 5 > >> 1 Effects of elastin haploinsufficiency on the mechanical behavior of mouse arteries Summary: mechanical testing. The carbon markers stick to...

170

LANL: Mechanical testing and modeling in MST  

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

etc.). As the effects of processing are to critical to accurate prediction of its mechanical behavior, MST hosts a range of metallographic and characterization tools. Specific...

171

Coulomb screening in graphene with topological defects  

E-Print Network (OSTI)

We analyze the screening of an external Coulomb charge in gapless graphene cone, which is taken as a prototype of a topological defect. In the subcritical regime, the induced charge is calculated using both the Green's function and the Friedel sum rule. The dependence of the polarization charge on the Coulomb strength obtained from the Green's function clearly shows the effect of the conical defect and indicates that the critical charge itself depends on the sample topology. Similar analysis using the Friedel sum rule indicates that the two results agree for low values of the Coulomb charge but differ for the higher strengths, especially in the presence of the conical defect. For a given subcritical charge, the transport cross-section has a higher value in the presence of the conical defect. In the supercritical regime we show that the coefficient of the power law tail of polarization charge density can be expressed as a summation of functions which vary log periodically with the distance from the Coulomb imp...

Chakraborty, Baishali; Sen, Siddhartha

2015-01-01T23:59:59.000Z

172

Defect analysis using resonant ultrasound spectroscopy  

E-Print Network (OSTI)

) ......................................................................... 62 Figure 4.5 FEA models of (a) Y Bend 1, (b) X Torsion 1, and (c) Z Bend 1 ......................................................................................... 64 Figure 4.6 Change in frequency vs. defect depth for mode Y Bend 1...................................................................................................... ix LIST OF TABLES .................................................................................................... xiii 1. INTRODUCTION............................................................................................... 1 1.1...

Flynn, Kevin Joseph

2009-05-15T23:59:59.000Z

173

Defect Tolerant Semiconductors for Solar Energy Conversion  

Science Journals Connector (OSTI)

Defect Tolerant Semiconductors for Solar Energy Conversion ... He obtained his Ph.D. in Physics at Paris-Sud University where he modeled Hot Carrier Solar Cells by means of Ensemble Monte Carlo methods. ... These surface energies are significantly lower compared to 96 and 102 meV/2 for (1010) and (1120) low energy nonpolar GaN surfaces respectively. ...

Andriy Zakutayev; Christopher M. Caskey; Angela N. Fioretti; David S. Ginley; Julien Vidal; Vladan Stevanovic; Eric Tea; Stephan Lany

2014-03-13T23:59:59.000Z

174

Defect Characterization for Scaling of QCA Devices  

E-Print Network (OSTI)

operation and ultra low power dissipation [8]. Among these new devices, quantum dot cellular automata (QCA promising new computing scheme in the nano-scale regimes. As an emerging technology, QCA relies on radically voter, the inverter and the binary wire, are provided to show that defects have definitive trends

175

RKKY interaction between extended magnetic defect lines in graphene  

Science Journals Connector (OSTI)

Of fundamental interest in the field of spintronics is the mechanism of indirect exchange coupling between magnetic impurities embedded in metallic hosts. A range of physical features, such as magnetotransport and overall magnetic moment formation, are predicated upon this magnetic coupling, often referred to as the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Recent theoretical studies on the RKKY in graphene have been motivated by possible spintronic applications of magnetically doped graphene systems. In this paper a combination of analytic and numerical techniques are used to examine the effects of defect dimensionality on such an interaction. We show, in a mathematically transparent manner, that moving from single magnetic impurities to extended lines of impurities effectively reduces the dimensionality of the system and increases the range of the interaction. This has important consequences for the spintronic application of magnetically-doped systems, and we illustrate this with a simple magnetoresistance device.

P. D. Gorman; J. M. Duffy; S. R. Power; M. S. Ferreira

2014-09-08T23:59:59.000Z

176

Buckling and Topological Defects in Graphene and Carbon Nanotubes  

E-Print Network (OSTI)

defect formation energy in carbon nanotubes and graphene.Carbon Nanotubes strain e zz Defect Formation Energies fromCARBON NANOTUBES Figure 4.3: Contour plots of strain energy

Chen, Shuo

2012-01-01T23:59:59.000Z

177

Estimating the expected latency to failure due to manufacturing defects  

E-Print Network (OSTI)

Manufacturers of digital circuits test their products to find defective parts so they are not sold to customers. Despite extensive testing, some of their products that are defective pass the testing process. To combat this problem, manufacturers...

Dorsey, David Michael

2004-09-30T23:59:59.000Z

178

Defect site prediction based upon statistical analysis of fault signatures  

E-Print Network (OSTI)

Good failure analysis is the ability to determine the site of a circuit defect quickly and accurately. We propose a method for defect site prediction that is based on a site's probability of excitation, making no assumptions about the type...

Trinka, Michael Robert

2004-09-30T23:59:59.000Z

179

THE DEFECT STRUCTURE OF CdTe (*) F. A. KRGER  

E-Print Network (OSTI)

THE DEFECT STRUCTURE OF CdTe (*) F. A. KR?GER David Packard Professor of Electrical Engineering haute résistivité. Abstract. 2014 Evidence concerning the defect structure of CdTe is reviewed

Paris-Sud XI, Université de

180

Modeling of virtual standards of vibration of defective bearing units  

Science Journals Connector (OSTI)

Results of studies designed to model vibration signals are presented below. A sample of time signals obtained as a result of cranking defective and defect-free bearings of railway freight cars on a test bench ser...

V. Yu. Tetter; E. N. Sidorov; E. A. Sidorova

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Defect- and Strain-enhanced Cavity Formation and Au Precipitation...  

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

Defect- and Strain-enhanced Cavity Formation and Au Precipitation at nano-crystalline ZrO2SiO2Si Interfaces . Defect- and Strain-enhanced Cavity Formation and Au Precipitation at...

182

Higgsless superconductivity from topological defects in compact BF terms  

E-Print Network (OSTI)

We present a new Higgsless model of superconductivity, inspired from anyon superconductivity but P- and T-invariant and generalizable to any dimension. While the original anyon superconductivity mechanism was based on incompressible quantum Hall fluids as average field states, our mechanism involves topological insulators as average field states. In D space dimensions it involves a (D-1)-form fictitious pseudovector gauge field which originates from the condensation of topological defects in compact low-energy effective BF theories. In the average field approximation, the corresponding uniform emergent charge creates a gap for the (D-2)-dimensional branes via the Magnus force, the dual of the Lorentz force. One particular combination of intrinsic and emergent charge fluctuations that leaves the total charge distribution invariant constitutes an isolated gapless mode leading to superfluidity. The remaining massive modes organise themselves into a D-dimensional charged, massive vector. There is no massive Higgs scalar as there is no local order parameter. When electromagnetism is switched on, the photon acquires mass by the topological BF mechanism. Although the charge of the gapless mode (2) and the topological order (4) are the same as those of the standard Higgs model, the two models of superconductivity are clearly different since the origins of the gap, reflected in the high-energy sectors are totally different. In 2D this type of superconductivity is explicitly realized as global superconductivity in Josephson junction arrays. In 3D this model predicts a possible phase transition from topological insulators to Higgsless superconductors.

M. Cristina Diamantini; Carlo A. Trugenberger

2014-08-29T23:59:59.000Z

183

Imaging Vertically Oriented Defects with Multi-Saft  

Science Journals Connector (OSTI)

Imaging vertically oriented defects using the Synthetic Aperture Focusing Technique (SAFT) requires special consideration. When the faces...

M. Lorenz; U. Stelwagen; A. J. Berkhout

1991-01-01T23:59:59.000Z

184

A new pathway in the generation of defective retrovirus DNA.  

Science Journals Connector (OSTI)

...pathway in the generation of defective retrovirus DNA. J C Olsen...suggest that in the formation of defective circular DNA, the U5 domain...II I I I I , I I Il I I 1. DEFECTIVE RETROVIRUS DNA 783 deletions...Nucleotide sequence analysis was car- ried out on the relevant...

J C Olsen; R Swanstrom

1985-12-01T23:59:59.000Z

185

Counting Defective Parking Functions Peter J Cameron, Daniel Johannsen,  

E-Print Network (OSTI)

the corresponding assignments a defective parking function of defect k. Suppose that m cars attempt to parkCounting Defective Parking Functions Peter J Cameron, Daniel Johannsen, Thomas Prellberg, Pascal a preferred parking space in a linear car park with n spaces. Each driver goes to the chosen space and parks

186

Survey Reproduction of Defect Reporting in Industrial Software Development  

Science Journals Connector (OSTI)

Context: Defect reporting is an important part of software development in-vivo, but previous work from open source context suggests that defect reports often have insufficient information for defect fixing. Objective: Our goal was to reproduce and partially ... Keywords: software debugging, software maintenance, software quality

Eero I. Laukkanen; Mika V. Mantyla

2011-09-01T23:59:59.000Z

187

AMEAerospace & Mechanical  

E-Print Network (OSTI)

AMEAerospace & Mechanical Engineering #12;Aerospace and Mechanical Engineers design complex mechanical, thermal, fluidic, acousti- cal, optical, and electronic systems, with char- acteristic sizes space. Aerospace and Mechanical Engineering (AME) students conduct basic and applied research within

Wang, Hai

188

Developing criteria for identifying acoustical defects  

Science Journals Connector (OSTI)

In a construction defect lawsuit of a multifamily residential project the determination of whether a defect exists often hinges on the criteria applied. For many acoustical items such as plumbing and HVAC noise there are no code requirements but a number of guidelines and recommendations. For items such as noise from traffic or airborne and impact sound isolation between units minimum code requirements exist but often a more stringent standard is applied. How does an expert decide when it is appropriate to apply an acoustical standard that is beyond that required by building codes? Project drawings marketing materials homeowner regulations and other documents can provide indications of the intent and promise of the project as it relates to acoustical issues. The process is discussed with examples from recent cases.

John LoVerde; David W. Dong

2013-01-01T23:59:59.000Z

189

Metastable light induced defects in pentacene  

SciTech Connect

In this study we analyzed one of the environmental factors that could affect organic materials. Pentacene thin film samples were fabricated and the degradation of their electrical characteristics was measured when the devices were exposed to ultraviolet light irradiation. The results have been reported in terms of a trap density model, which provides a description of the dynamics of light induced electrically active defects in an organic semiconductor.

Liguori, R.; Aprano, S.; Rubino, A. [Department of Industrial Engineering (DIIn), University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (Italy)

2014-02-21T23:59:59.000Z

190

Investigating Extreme Ultraviolet Lithography Mask Defects  

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

Investigating Extreme Ultraviolet Lithography Mask Defects Print Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper semiconductors. EUV lithography relies on specialized lenses made of curved mirrors with reflective coatings called multilayers to print patterns with high resolution. One special flat mirror called a mask is particularly sensitive to even the smallest imperfections. To better detect and characterize mask defects, scientists at Berkeley Lab worked with SEMATECH, an international semiconductor industry consortium, to create a unique Fresnel zone-plate microscope on Advanced Light Source Beamline 11.3.2 called the SEMATECH Berkeley Actinic Inspection Tool (AIT).

191

Investigating Extreme Ultraviolet Lithography Mask Defects  

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

Investigating Extreme Investigating Extreme Ultraviolet Lithography Mask Defects Investigating Extreme Ultraviolet Lithography Mask Defects Print Wednesday, 28 July 2010 00:00 Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper semiconductors. EUV lithography relies on specialized lenses made of curved mirrors with reflective coatings called multilayers to print patterns with high resolution. One special flat mirror called a mask is particularly sensitive to even the smallest imperfections. To better detect and characterize mask defects, scientists at Berkeley Lab worked with SEMATECH, an international semiconductor industry consortium, to create a unique Fresnel zone-plate microscope on Advanced Light Source Beamline 11.3.2 called the SEMATECH Berkeley Actinic Inspection Tool (AIT).

192

Investigating Extreme Ultraviolet Lithography Mask Defects  

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

Investigating Extreme Ultraviolet Lithography Mask Defects Print Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper semiconductors. EUV lithography relies on specialized lenses made of curved mirrors with reflective coatings called multilayers to print patterns with high resolution. One special flat mirror called a mask is particularly sensitive to even the smallest imperfections. To better detect and characterize mask defects, scientists at Berkeley Lab worked with SEMATECH, an international semiconductor industry consortium, to create a unique Fresnel zone-plate microscope on Advanced Light Source Beamline 11.3.2 called the SEMATECH Berkeley Actinic Inspection Tool (AIT).

193

Hydrogen passivation of EL2 defects and H2*-like complex formation in gallium arsenide  

Science Journals Connector (OSTI)

A complex formed by one As antisite (AsGa), one As, and two H atoms is proposed, in GaAs, which is reminiscent of the H2* defect in crystalline Si and properly accounts for the hydrogen neutralization of the EL2 deep donor activity. It is noticeably stable, in agreement with experimental results. The geometry and electronic structure of this complex present interesting connections with those of the isolated As antisite which clarify the EL2 passivation mechanism.

A. Amore Bonapasta

1995-02-15T23:59:59.000Z

194

Microstructure and Mechanical Properties of n-irradiated Fe-Cr Model Alloys  

SciTech Connect

High chromium ( 9-12 wt %) ferritic/martensitic steels are candidate structural materials for future fusion reactors and other advanced systems such as accelerator driven systems (ADS). Their use for these applications requires a careful assessment of their mechanical stability under high energy neutron irradiation and in aggressive environments. In particular, the Cr concentration has been shown to be a key parameter to be optimized in order to guarantee the best corrosion and swelling resistance, together with the least embrittlement. In this work, the characterization of the neutron irradiated Fe-Cr model alloys with different Cr % with respect to microstructure and mechanical tests will be presented. The behavior of Fe-Cr alloys have been studied using tensile tests at different temperature range ( from -160 deg. C to 300 deg. C). Irradiation-induced microstructure changes have been studied by TEM for two different irradiation doses at 300 deg. C. The density and the size distribution of the defects induced have been determined. The tensile test results indicate that Cr content affects the hardening behavior of Fe-Cr binary alloys. Hardening mechanisms are discussed in terms of Orowan type of approach by correlating TEM data to the measured irradiation hardening. (authors)

Matijasevic, Milena; Al Mazouzi, Abderrahim [Reactor materials research, SCK-CEN, Mol (Belgium)

2008-07-01T23:59:59.000Z

195

Mechanical Network in Titin Immunoglobulin from Force Distribution Analysis  

E-Print Network (OSTI)

Mechanical Network in Titin Immunoglobulin from Force Distribution Analysis Wolfram Stacklies1. , M, Stuttgart, Germany Abstract The role of mechanical force in cellular processes is increasingly revealed force propagates within proteins determines their mechanical behavior yet remains largely unknown. We

Gräter, Frauke

196

Understanding the Irradiation Behavior of Zirconium Carbide  

SciTech Connect

Zirconium carbide (ZrC) is being considered for utilization in high-temperature gas-cooled reactor fuels in deep-burn TRISO fuel. Zirconium carbide possesses a cubic B1-type crystal structure with a high melting point, exceptional hardness, and good thermal and electrical conductivities. The use of ZrC as part of the TRISO fuel requires a thorough understanding of its irradiation response. However, the radiation effects on ZrC are still poorly understood. The majority of the existing research is focused on the radiation damage phenomena at higher temperatures (>450{degree}C) where many fundamental aspects of defect production and kinetics cannot be easily distinguished. Little is known about basic defect formation, clustering, and evolution of ZrC under irradiation, although some atomistic simulation and phenomenological studies have been performed. Such detailed information is needed to construct a model describing the microstructural evolution in fast-neutron irradiated materials that will be of great technological importance for the development of ZrC- based fuel. The goal of the proposed project is to gain fundamental understanding of the radiation-induced defect formation in zirconium carbide and irradiation response (ZrC) by using a combination of state-of-the-art experimental methods and atomistic modeling. This project will combine (1) in situ ion irradiation at a specialized facility at a national laboratory, (2) controlled temperature proton irradiation on bulk samples, and (3) atomistic modeling to gain a fundamental understanding of defect formation in ZrC. The proposed project will cover the irradiation temperatures from cryogenic temperature to as high as 800{degree}C, and dose ranges from 0.1 to 100 dpa. The examination of this wide range of temperatures and doses allows us to obtain an experimental data set that can be effectively used to exercise and benchmark the computer calculations of defect properties. Combining the examination of radiation-induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.

Motta, Arthur; Sridharan, Kumar; Morgan, Dane; Szlufarska, Izabela

2013-10-11T23:59:59.000Z

197

The role of point defects and defect complexes in silicon device processing. Summary report and papers  

SciTech Connect

This report is a summary of a workshop hold on August 24--26, 1992. Session 1 of the conference discussed characteristics of various commercial photovoltaic silicon substrates, the nature of impurities and defects in them, and how they are related to the material growth. Session 2 on point defects reviewed the capabilities of theoretical approaches to determine equilibrium structure of defects in the silicon lattice arising from transitional metal impurities and hydrogen. Session 3 was devoted to a discussion of the surface photovoltaic method for characterizing bulk wafer lifetimes, and to detailed studies on the effectiveness of various gettering operations on reducing the deleterious effects of transition metals. Papers presented at the conference are also included in this summary report.

Sopori, B.; Tan, T.Y.

1994-08-01T23:59:59.000Z

198

Mapping hidden aircraft defects with dual-band infrared computed tomography  

SciTech Connect

Infrared computed tomography (IRCT) is a promising, non-contact, nondestructive evaluation tool used to inspect the mechanical integrity of large structures. We describe on-site, proof-of-principle demonstrations of IRCt to inspect defective metallic and composite structures. The IRCT system captures time sequences of heat-stimulated, dual-band infrared (DBIR) thermal maps for flash-heated and naturally-heated targets. Our VIEW algorithms produce co-registered thermal, thermal inertia, and thermal-timegram maps from which we quantify the percent metal-loss corrosion damage for airframes and the defect sites, depths, and host-material physical properties for composite structures. The IRCT method clarifies the type of defect, e.g., corrosion, fabrication, foreign-material insert, delamination, unbond, void, and quantifies the amount of damage from the defect, e.g., the percent metal-loss from corrosion in metal structures, the depth, thickness, and areal extent of heat damage in multi-layered composite materials. Potential long-term benefits of IRCT technology are in-service monitoring of incipient corrosion damage, to avoid catastrophic failure and production-monitoring of cure states for composite materials.

Del Grande, N.K.; Durbin, P.F.

1995-04-03T23:59:59.000Z

199

Chapter Two - Pipeline Defects and Corrective Actions  

Science Journals Connector (OSTI)

Abstract One important part of pipeline integrity management activity encompasses the repair and maintenance of anomalies by the maintenance crew. In addition to the advanced inspection tools, knowledge of pipeline defects and how to conduct both immediate and scheduled repairs is of critical importance. The pipeline industry had used the ASME B31G criteria to evaluate corroded pipe for removal or repair. However, there was a need to establish a new approach. The modified criteria were therefore established with the objective to reduce excess conservatism without creating an unsafe condition.

Ramesh Singh

2014-01-01T23:59:59.000Z

200

DFT+U Study of CeO2 and Its Native Defects  

E-Print Network (OSTI)

in solid state fuel cells2, as a catalyst3-6, as a high-dielectric constant gate oxide7, and in resistance random access memories (ReRAM)8. Many properties of CeO2 are determined by its intrinsic defects9-23 and the unusual behavior of the semi-core Ce 4f... averaging scheme46 for spin- orbital coupling effect. The RRKJ method is chosen as optimization of pseudopotentials47. The PBE functional was chosen for PBE+U calculations with a kinetic cutoff energy of 750eV, which expands the valence electrons states...

Huang, Bolong; Gillen, Roland; Robertson, John

2014-10-14T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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201

Argonne CNM Highlight: Mechanical energy dissipation in  

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

Mechanical Energy Dissipation in Ultrananocrystalline Diamond Microresonators Mechanical Energy Dissipation in Ultrananocrystalline Diamond Microresonators SEM micrograph of UNCD microresonator SEM micrograph of fabricated UNCD microresonator Researchers in the Nanofabrication and Devices group, in collaboration with the University of Pennsylvania, Advanced Diamond Technologies Inc., and Innovative Micro Technology, have discovered that defects at the grain boundary in ultrananocrystalline diamond (UNCD) hold primary responsibility for the fundamental mechanism of energy dissipation. Because of a high Young's modulus and high sound propagation velocity, UNCD materials hold potential for fabricating high-frequency microelectromechanical (MEMS) resonators. However, their mechanical dissipation at high frequency, which is important for developing high-frequency resonator applications, is not

202

Physisorption of molecular hydrogen on carbon nanotube with vacant defects  

SciTech Connect

Physisorption of molecular hydrogen on single-walled carbon nanotubes (SWCNTs) is important for its engineering applications and hydrogen energy storage. Using molecular dynamics simulation, we study the physisorption of molecular hydrogen on a SWCNT with a vacant defect, focusing on the effect of the vacant defect size and external parameters such as temperature and pressure. We find that hydrogen can be physisorbed inside a SWCNT through a vacant defect when the defect size is above a threshold. By controlling the size of the defects, we are able to extract hydrogen molecules from a gas mixture and store them inside the SWCNT. We also find that external parameters, such as low temperature and high pressure, enhance the physisorption of hydrogen molecules inside the SWCNT. In addition, the storage efficiency can be improved by introducing more defects, i.e., reducing the number of carbon atoms on the SWCNT.

Sun, Gang; Shen, Huaze; Wang, Enge; Xu, Limei, E-mail: limei.xu@pku.edu.cn [International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Tangpanitanon, Jirawat [University of Cambridge, Cambridge, Cambridgeshire CB2 1TP (United Kingdom); Wen, Bo [International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China); Beijing Computational Science Research Center, Heqing Street, Haidian District, Beijing 100084 (China); Xue, Jianming [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)

2014-05-28T23:59:59.000Z

203

AUTOMATED DEFECT CLASSIFICATION USING AN ARTIFICIAL NEURAL NETWORK  

SciTech Connect

The automated defect classification algorithm based on artificial neural network with multilayer backpropagation structure was utilized. The selected features of flaws were used as input data. In order to train the neural network it is necessary to prepare learning data which is representative database of defects. Database preparation requires the following steps: image acquisition and pre-processing, image enhancement, defect detection and feature extraction. The real digital radiographs of welded parts of a ship were used for this purpose.

Chady, T.; Caryk, M. [Szczecin University of Technology, Department of Electrical Engineering (Poland); Piekarczyk, B. [Technic-Control, Szczecin (Poland)

2009-03-03T23:59:59.000Z

204

Evolution of Frictional Behavior of Punchbowl Fault Gouges Sheared at Seismic Slip Rates and Mechanical and Hydraulic Properties of Nankai Trough Accretionary Prism Sediments Deformed at Different Loading Paths  

E-Print Network (OSTI)

Frictional measurements were made on natural fault gouge at seismic slip rates using a high-speed rotary-shear apparatus to study effects of slip velocity, acceleration, displacement, normal stress, and water content. Thermal-, mechanical...

Kitajima, Hiroko

2012-02-14T23:59:59.000Z

205

Simple intrinsic defects in GaAs : numerical supplement.  

SciTech Connect

This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

Schultz, Peter Andrew

2012-04-01T23:59:59.000Z

206

SciTech Connect: Thermal Hydraulic Characteristics of Fuel Defects...  

Office of Scientific and Technical Information (OSTI)

VA at www.ntis.gov. Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors Turbulent flow coupled with heat transfer is investigated for a...

207

Defect Migration and Recombination in Nanoindentation of Silica...  

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

Defect Migration and Recombination in Nanoindentation of Silica Glass Authors: Nomura, K., Chen, Y., Kalia, R.K., Nakano, A., Vashishta, P. Deformation, plasticity, and flow in...

208

Surface defect states in MBE-grown CdTe layers  

SciTech Connect

Semiconductor surface plays an important role in the technology of semiconductor devices. In the present work we report results of our deep-level transient spectroscopy (DLTS) investigations of surface defect states in nitrogen doped p-type CdTe layers grown by the molecular-beam epitaxy technique. We observed a deep-level trap associated with surface states, with the activation energy for hole emission of 0.33 eV. DLTS peak position in the spectra for this trap, and its ionization energy, strongly depend on the electric field. Our measurements allow to determine a mechanism responsible for the enhancement of hole emission rate from the traps as the phonon-assisted tunnel effect. Density of surface defect states significantly decreased as a result of passivation in ammonium sulfide. Capacitance-voltage measurements confirmed the results obtained by the DLTS technique.

Olender, Karolina; Wosinski, Tadeusz; Fronc, Krzysztof; Tkaczyk, Zbigniew; Chusnutdinow, Sergij; Karczewski, Grzegorz [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland)

2014-02-21T23:59:59.000Z

209

Using Gold Nanoparticles as Artificial Defects in Thin Films: What Have We Learned About Laser-Induced Damage Driven by Localized Absorbers?  

SciTech Connect

There is general agreement that localized absorbing defects are a major factor affecting thin-film performance, and laser-induced damage in films designed for UV, nanosecond-scale, pulsed-laser applications is driven by nanoscale absorbers. Low number densities and size (few nanometer), however, prevent any characterization of these defects and, consequently, deterministic film improvement. This situation also hampers further development of localized defect-driven damage theory, since initial conditions for modeling remain uncertain. Recently, a new approach for studying laser interaction with thin-film nanoscale defects was implemented in which well-characterized, isolated artificial absorbing defects (gold nanoparticles) were introduced inside the thin film. This work is a review in which we discuss main findings from experiments with gold nanoparticles, such as delocalization of absorption during the laser pulse, importance of the defect boundary conditions (contact with the matrix), and competition of pure thermal and stress-driven mechanisms of damage-crater formation. These experimental results will be compared with theoretical results of damage-crater formation in such model thin films using both phenomenological modeling and detailed calculations of the kinetics of the damage process. An outlook on future thin-film-damage studies using model systems with artificial defects is also presented.

Papernov, S.; Schmid, A.W.

2007-03-14T23:59:59.000Z

210

Quantitative Quality Management through Defect Prediction and Statistical Process Control  

E-Print Network (OSTI)

Quantitative Quality Management through Defect Prediction and Statistical Process Control Pankaj: To produce high quality software, the final software should have as few defects as possible. The task of quality management in a software project is to plan suitable quality control activities, and properly

Jalote, Pankaj

211

Understanding of Defect Physics in Polycrystalline Photovoltaic Materials: Preprint  

SciTech Connect

The performance of thin-film solar cells is influenced by the quality of interfaces and formation of defects such as point defects, stacking faults, twins, dislocations, and grain boundaries. It is important to understand the defect physics so that appropriate methods may be developed to suppress the formation of harmful defects. Here, we review our understanding of defect physics in thin-film photovoltaic (PV) materials such as Si, CdTe, Cu(In,Ga)Se2 (CIGS), Cu2ZnSnSe2 (CZTSe), and Cu2ZnSnS2 (CZTS) using the combination of nanoscale electron microscopy characterization and density-functional theory (DFT). Although these thin-film PV materials share the same basic structural feature - diamond structure based - the defect physics in them could be very different. Some defects, such as stacking faults and special twins, have similar electronic properties in these thin-film materials. However, some other defects, such as grain boundaries and interfaces, have very different electronic properties in these materials. For example, grain boundaries produce harmful deep levels in Si and CdTe, but they do not produce significant deep levels in CIGS, CZTSe, and CZTS. These explain why passivation is critical for Si and CdTe solar cells, but is less important in CIS and CZTS solar cells. We further provide understanding of the effects of interfaces on the performance of solar cells made of these PV materials.

Yan, Y.

2011-07-01T23:59:59.000Z

212

Counting Defective Parking Functions Peter J Cameron, Daniel Johannsen,  

E-Print Network (OSTI)

parking function of defect k. Suppose that m cars attempt to park in a linear car park with n spacesCounting Defective Parking Functions Peter J Cameron, Daniel Johannsen, Thomas Prellberg, Pascal each choose a preferred parking space in a linear car park with n spaces. Each driver goes

Prellberg, Thomas

213

Replication-Defective Vector Based on a Chimpanzee Adenovirus  

Science Journals Connector (OSTI)

...rendered replication defective by deletion of E1 sequences...coxsackievirus and adenovirus (CAR) receptor, such chimeric...fiber proteins. The CAR binding site in the fiber...explanation of the role of CAR in C68 uptake, refer...C68. A replication-defective version of C68 was isolated...

Steven F. Farina; Guang-ping Gao; Z. Q. Xiang; John J. Rux; Roger M. Burnett; Mauricio R. Alvira; Jonathan Marsh; Hildegund C. J. Ertl; James M. Wilson

2001-12-01T23:59:59.000Z

214

Actinic characterization of EUV bump-type phase defects  

SciTech Connect

Despite tremendous progress and learning with EUV lithography, quantitative experimental information about the severity of point-like phase defects remains in short supply. We present a study of measured, EUV aerial images from a series of well-characterized, open-field, bump-type programmed phase defects, created on a substrate before multilayer deposition.

Goldberg, Kenneth A.; Mochi, Iacopo; Liang, Ted

2011-01-10T23:59:59.000Z

215

Fatigue crack growth testing of sub-clad defects  

SciTech Connect

Fatigue crack growth tests were performed on four-point bend specimens with cracklike defects intentionally placed in A302B low-alloy pressure vessel steel clad with 308/309L weld-deposited stainless steel. The defects were placed in the base metal under the cladding by machining a cavity from the side opposite the cladding, electric-discharge machining a very sharp flaw, fatigue precracking the flaw, and then filling up the cavity by a weld repair process. The specimens were stress relieved before fatigue testing. The specimens were fatigue cycled at positive load ratios until the defects broke through to the surface. The specimens were then fractured at liquid nitrogen temperatures to reveal the fracture surfaces. Seven different sub-clad flaw specimens were tested in room temperature air and each test provides a record of cycles to defect breakthrough. Changes in defect size and shape as a function of applied load cycles were obtained by beach-marking the crack at various stages of the load history. The results provide a set of embedded defect data which can be used for qualifying fatigue crack growth analysis procedures such as those in Section XI of the ASME boiler and Pressure Vessel Code. A comparison between calculated and measured values shows that the ASME B and PV Section XI fatigue crack growth procedures conservatively predict cycles to defect breakthrough for small sub-clad defects.

Jones, D.P.; Leax, T.R. [Bechtel Bettis, Inc., West Mifflin, PA (United States). Bettis Atomic Power Lab.

1999-08-01T23:59:59.000Z

216

Defect-induced magnetism and transport phenomena in epitaxial oxides  

E-Print Network (OSTI)

that the transition metal dopants (i.e. Mn) have no influence on the ferromagnetic nature of the zinc oxide, but that localised magnetic moments on intrinsic defects are in fact responsible for the ferromagnetic behaviour. A relation between strain (related to defect...

Schoofs, Frank

2012-07-03T23:59:59.000Z

217

Apple Defect Segmentation by Artificial Neural Networks Devrim Unay a  

E-Print Network (OSTI)

Apple Defect Segmentation by Artificial Neural Networks Devrim Unay a Bernard Gosselin a a TCTS Lab-colored apple fruits performed by several artificial neural networks. Pixel-wise classification approach apple defects. 1 Introduction Quality of apple fruits depends on size, color, shape and presence

Dupont, Stéphane

218

Point Defect Characterization in CdZnTe  

SciTech Connect

Measurements of the defect levels and performance testing of CdZnTe detectors were performed by means of Current Deep Level Transient Spectroscopy (I-DLTS), Transient Charge Technique (TCT), Current versus Voltage measurements (I-V), and gamma-ray spectroscopy. CdZnTe crystals were acquired from different commercial vendors and characterized for their point defects. I-DLTS studies included measurements of defect parameters such as energy levels in the band gap, carrier capture cross sections, and defect densities. The induced current due to laser-generated carriers was measured using TCT. The data were used to determine the transport properties of the detectors under study. A good correlation was found between the point defects in the detectors and their performance.

Gul,R.; Li, Z.; Bolotnikov, A.; Keeter, K.; Rodriguez, R.; James, R.

2009-03-24T23:59:59.000Z

219

Elastohydrodynamic behavior of compliant slider bearings  

E-Print Network (OSTI)

ELASTOHYDRODYNAMIC BEHAVIOR OF COMPLIANT SLIDER BEARINGS A Thesis by RODNEY EMERSON HERRINGTON Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1973 Major Subject: Mechanical Engineering ELASTOHYDRODYNAMIC BEHAVIOR OF COMPLIANT SLIDER BEARINGS A Thesis by RODNEY EMERSON HERRINGTON Approved as to style and content by: (Chairma of Committee) (Head of Department) (Member) (Member...

Herrington, Rodney Emerson

2012-06-07T23:59:59.000Z

220

Defect formation in long Josephson junctions  

SciTech Connect

We study numerically a mechanism of vortex formation in a long Josephson junction within the framework of the one-dimensional sine-Gordon model. This mechanism is switched on below the critical temperature. It is shown that the number of fluxons versus velocity of cooling roughly scales according to the power law with the exponent of either 0.25 or 0.5 depending on the temperature variation in the critical current density.

Gordeeva, Anna V. [Institute for Physics of Microstructures, RAS, GSP-105, Nizhny Novgorod 603950 (Russian Federation); Department of Physics, B309, Technical University of Denmark, DK-2800 Lyngby (Denmark); Pankratov, Andrey L. [Institute for Physics of Microstructures, RAS, GSP-105, Nizhny Novgorod 603950 (Russian Federation)

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Center for Materials at Irradiation and Mechanical Extremes:...  

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

Nanosteller. He has organized the DOE workshop on Computational issues in the mechanical behavior of metals and intermetallics and was co-organizer of IUMRS-ICAM-93:...

222

Center for Materials at Irradiation and Mechanical Extremes:...  

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

postdoctoral researchers at LANL on all CMIME research teams. Background in mechanical behavior andor radiation effects in structural metals andor ceramics is needed,...

223

Center for Materials at Irradiation and Mechanical Extremes:...  

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

effects in metallic materials Transmission electron microscopy Sample Publications "Mechanical Behavior of Metallic Nanolaminates," A. Misra, chapter in Nanostructure Control of...

224

Infrared birefringence imaging of residual stress and bulk defects in multicrystalline silicon  

SciTech Connect

This manuscript concerns the application of infrared birefringence imaging (IBI) to quantify macroscopic and microscopic internal stresses in multicrystalline silicon (mc-Si) solar cell materials. We review progress to date, and advance four closely related topics. (1) We present a method to decouple macroscopic thermally-induced residual stresses and microscopic bulk defect related stresses. In contrast to previous reports, thermally-induced residual stresses in wafer-sized samples are generally found to be less than 5 MPa, while defect-related stresses can be several times larger. (2) We describe the unique IR birefringence signatures, including stress magnitudes and directions, of common microdefects in mc-Si solar cell materials including: {beta}-SiC and {beta}-Si{sub 3}N{sub 4} microdefects, twin bands, nontwin grain boundaries, and dislocation bands. In certain defects, local stresses up to 40 MPa can be present. (3) We relate observed stresses to other topics of interest in solar cell manufacturing, including transition metal precipitation, wafer mechanical strength, and minority carrier lifetime. (4) We discuss the potential of IBI as a quality-control technique in industrial solar cell manufacturing.

Ganapati, Vidya; Schoenfelder, Stephan; Castellanos, Sergio; Oener, Sebastian; Koepge, Ringo; Sampson, Aaron; Marcus, Matthew A.; Lai, Barry; Morhenn, Humphrey; Hahn, Giso; Bagdahn, Joerg; Buonassisi1, Tonio

2010-05-05T23:59:59.000Z

225

Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide  

SciTech Connect

As a candidate material for fusion reactor applications, silicon carbide (SiC) undergoes transmutation reactions under high-energy neutron irradiation with magnesium as the major metallic transmutant; the others include aluminum, beryllium and phosphorus in addition to helium and hydrogen gaseous species. The impact of these transmutants on SiC structural stability is currently unknown. This study uses ion implantation to introduce Mg into SiC. Multiaxial ion-channeling analysis of the as-produced damage state suggests that there are preferred Si <100> interstitial splits. The microstructure of the annealed sample was examined using high-resolution scanning transmission electron microscopy. The results show a high concentration of likely non-faulted tetrahedral voids and possible stacking fault tetrahedra near the damage peak. In addition to lattice distortion, dislocations and intrinsic and extrinsic stacking faults are also observed. Magnesium in 3C-SiC prefers to substitute for Si and it forms precipitates of cubic Mg2Si and tetragonal MgC2. The diffusion coefficient of Mg in 3C-SiC single crystal at 1573 K has been determined to be 3.80.410e-19 m2/sec.

Jiang, Weilin; Jung, Hee Joon; Kovarik, Libor; Wang, Zhaoying; Roosendaal, Timothy J.; Zhu, Zihua; Edwards, Danny J.; Hu, Shenyang Y.; Henager, Charles H.; Kurtz, Richard J.; Wang, Yongqiang

2015-01-01T23:59:59.000Z

226

Improved theoretical methods for studies of defects in insulators: Application to the F center in LiF  

Science Journals Connector (OSTI)

An F center in the lithium fluoride (LiF) crystal is investigated with use of the muffin-tin Greens-function formalism and a linear combination of atomic orbitals (LCAO) cluster method. Both of these methods properly embed the defect into the host crystal. With the latter method, we are able to include the defect-induced charge relaxation on many shells of nearest-neighbor atoms. We have employed several variants of the density-functional approximation which allow a more accurate description of the ground-state single-electron properties. These methods include an empirical adjustment of the perfect-crystal band gap [the LDA scissor operator (where LDA denotes local-density approximation)] as well as the inclusion of electronic self-interaction corrections. Since the validity of the density-functional formalism is questionable for obtaining excited-state properties, we have introduced a single particle-hole excited-state theory, which is based on many-electron arguments, in order to gain insight about the behavior of the excited-state effective potentials. We demonstrate that, in contrast to LDA, for localized excitations the long-range behavior of the effective excited-state potential should exhibit a -1/r tail in neutral systems. While the qualitative behavior of the LDA potential differs from the effective excited-state potential, the self-interaction-corrected LDA potential of the highest occupied defect level exhibits the correct qualitative behavior. By allowing the excited state electron to move in the latter potential, an accurate excitation energy for the a1g-t1u absorption in LiF is obtained. Further, in contrast to the density-functional results, the self-interaction-corrected version of the theory correctly places the t1u state below the conduction-band edge.

Mark R. Pederson and Barry M. Klein

1988-06-15T23:59:59.000Z

227

The spatial evaluation of neighborhood clusters of birth defects  

SciTech Connect

Spatial statistics have recently been applied in epidemiology to evaluate clusters of cancer and birth defects. Their use requires a comparison population, drawn from the population at risk for disease, that may not always be readily available. In this dissertation the plausibility of using data on all birth defects, available from birth defects registries, as a surrogate for the spatial distribution of all live births in the analysis of clusters is assessed. Three spatial statistics that have been applied in epidemiologic investigations of clusters, nearest neighbor distance, average interpoint distance, and average distance to a fixed point, were evaluated by computer simulation for their properties in a unit square, and in a zip code region. Comparison of spatial distributions of live births and birth defects was performed by drawing samples of live births and birth defects from Santa Clara County, determining the street address at birth, geocoding this address and evaluating the resultant maps using various statistical techniques. The proposed method was then demonstrated on a previously confirmed cluster of oral cleft cases. All live births for the neighborhood were geocoded, as were all birth defects. Evaluation of this cluster using the nearest neighbor and average interpoint distance statistics was performed using randomization techniques with both the live births population and the birth defect population as comparison groups. 113 refs., 36 figs., 16 tabs.

Frisch, J.D.

1990-04-16T23:59:59.000Z

228

Diffraction of light by topological defects in liquid crystals  

E-Print Network (OSTI)

We study light scattering by a hedgehog-like and linear disclination topological defects in a nematic liquid crystal by a metric approach. Light propagating near such defects feels an effective metric equivalent to the spatial part of the global monopole and cosmic string geometries. We obtain the scattering amplitude and the differential and total scattering cross section for the case of the hedgehog defect, in terms of the characteristic parameters of the liquid crystal. Studying the disclination case, a cylindrical partial wave method is developed. As an application of the previous developments, we also examine the temperature influence on the localization of the diffraction patterns.

E. Pereira; F. Moraes

2010-11-22T23:59:59.000Z

229

Icosahedral order and defects in metallic liquids and glasses  

Science Journals Connector (OSTI)

Molecular-dynamics simulations of 500 particles have been performed to study the icosahedral order and the defects in the supercooled liquid and glass states of metallic Mg3Ca7. Not only are Frank-Kasper polyhedra and Bernal hole polyhedra detected, but also a variety of defective icosahedra. Especially, the number of the type of defective icosahedron defined by eight 1551 bonds, two 1661 bonds, and two 1441 bonds is much greater than the number of any kind of Frank-Kasper and Bernal polyhedra. This strongly supports the physical picture of liquids and glasses being a disordered, entangled array of +72 and -72 disclination lines in an icosahedral medium.

D. W. Qi and S. Wang

1991-07-01T23:59:59.000Z

230

Probing graphene defects and estimating graphene quality with optical microscopy  

SciTech Connect

We report a simple and accurate method for detecting graphene defects that utilizes the mild, dry annealing of graphene/Cu films in air. In contrast to previously reported techniques, our simple approach with optical microscopy can determine the density and degree of dislocation of defects in a graphene film without inducing water-related damage or functionalization. Scanning electron microscopy, confocal Raman and atomic force microscopy, and X-ray photoelectron spectroscopy analysis were performed to demonstrate that our nondestructive approach to characterizing graphene defects with optimized thermal annealing provides rapid and comprehensive determinations of graphene quality.

Lai, Shen [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); Kyu Jang, Sung [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Jae Song, Young, E-mail: yjsong@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Department of Physics, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Lee, Sungjoo, E-mail: leesj@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of)

2014-01-27T23:59:59.000Z

231

Modeling of three dimensional defects in integrated circuits  

E-Print Network (OSTI)

Critical regions shown in black for CM F intrusions of cube shaped defect of side 5 p. 52 Critical regions shown in black for CP G protrusions of cube shaped defect of side 5 p. 33 Critical regions shown in black lor shorts between CAA and CMF for a... cube shaped defect of side 4 p. 54 Critical regions shown in black for breaks bctwccn CPG and CMF for a cube shaped del'ect of side 5 p. 35 A layout in three styles (a) Tgm (b) Pla. (c) Std. 36 Sensitivities of CPG-CMI' prism sized shorts for (a...

Dani, Sameer Manohar

2012-06-07T23:59:59.000Z

232

Saturation of light?induced defects in a?Si:H  

Science Journals Connector (OSTI)

The steady?state defect density in hydrogenated amorphous silicon (a?Si:H) under illumination was investigated for a wide range of illumination intensities and temperatures. The saturation defect density under illumination is both temperature and light intensity dependent. A chemical equilibrium model for light?induced defect generation is proposed. According to the model defect generation is enhanced under illumination due to the reduction of the defect formation energy when the bands are populated by photogenerated carriers. Defect generation is a self limiting process and the defect density reaches a saturation value at long illumination time despite the existence of an extended distribution of defect formation sites.

P. V. Santos; W. B. Jackson; R. A. Street

1991-01-01T23:59:59.000Z

233

E-Print Network 3.0 - atomic scale defect Sample Search Results  

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

assembled DNA nanostructures. Atomic force microscope (AFM) images are used... of defect identification. 4.1 Defect ... Source: Chakrabarty, Krishnendu - Department of Electrical...

234

Modeling and experimental characterization of stepped and v-shaped (311) defects in silicon  

SciTech Connect

We propose an atomistic model to describe extended (311) defects in silicon. It is based on the combination of interstitial and bond defect chains. The model is able to accurately reproduce not only planar (311) defects but also defect structures that show steps, bends, or both. We use molecular dynamics techniques to show that these interstitial and bond defect chains spontaneously transform into extended (311) defects. Simulations are validated by comparing with precise experimental measurements on actual (311) defects. The excellent agreement between the simulated and experimentally derived structures, regarding individual atomic positions and shape of the distinct structural (311) defect units, provides strong evidence for the robustness of the proposed model.

Marqus, Luis A., E-mail: lmarques@ele.uva.es; Aboy, Mara [Departamento de Electrnica, Universidad de Valladolid, E.T.S.I. de Telecomunicacin, 47011 Valladolid (Spain); Dudeck, Karleen J.; Botton, Gianluigi A. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Knights, Andrew P. [Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Gwilliam, Russell M. [Surrey Ion Beam Centre, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2014-04-14T23:59:59.000Z

235

E-Print Network 3.0 - automatic defect classification Sample...  

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

defects and color transition areas of skin... introduced an automatic system to detect patch-like defects on apples by computer vision, where he used... , respectively. It should...

236

E-Print Network 3.0 - active defects induced Sample Search Results  

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

for Multistage Production Systems with Time-Varying Quality Summary: assume that repair of one defect type cannot induce a defect of another type. There are three...

237

Physink: sketching physical behavior  

E-Print Network (OSTI)

Describing device behavior is a common task that is currently not well supported by general animation or CAD software. We present PhysInk, a system that enables users to demonstrate 2D behavior by sketching and directly ...

Davis, Randall

238

Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder  

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

Defect Analysis of Vehicle Defect Analysis of Vehicle Compressed Natural Gas Composite Cylinder A China Paper on Type 4 Cylinder, translated and presented by J. P. Hsu, PhD, Smart Chemistry Reason for Defect Analysis of CNG Composite Cylinder * Safety Issue - Four explosion accidents of auto used CNG composite material cylinders resulting huge personnel and vehicles loss. * Low Compliance Rate - Inspect 12119 Auto used CNG composite cylinders and only 3868 are qualified with compliance rate of 32%. Plastic CNG Composite Cylinder Process Fitting Internal Plastic Liner External Composite Layer Metal Fitting HDPE Cylinder Liner * HDPE has a high density, great stiffness, good anti-permeability and high melting point, but poor environmental stress cracking Resistance (ESCR). * The defects of cylinder liner quality can be

239

NHTSA's Office of Defects Investigation (ODI) - Technical Service Bulletins  

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

NHTSA's Office of Defects Investigation (ODI) - Technical Service Bulletins NHTSA's Office of Defects Investigation (ODI) - Technical Service Bulletins System (TSBS) - Downloadable file Manufacturing Data/Tools Research/Tech Services Apps Challenges Blogs Let's Talk Manufacturing You are here Data.gov » Communities » Manufacturing » Data NHTSA's Office of Defects Investigation (ODI) - Technical Service Bulletins System (TSBS) - Downloadable file Dataset Summary Description The Technical Service Bulletins data contains summaries of the Manufacturers' Technical Service Bulletins by single year, make and model. An optional item of Vehicle Component may be also available. (The data does not contain all the service bulletins generated by a manufacturer. Bulletins for safety recalls in general are not included, and also bulletins which may not pertain to a defect may not be included.)

240

The geodesic rule for higher codimensional global defects  

E-Print Network (OSTI)

We generalize the geodesic rule to the case of formation of higher codimensional global defects. Relying on energetic arguments, we argue that, for such defects, the geometric structures of interest are the totally geodesic submanifolds. On the other hand, stochastic arguments lead to a diffusion equation approach, from which the geodesic rule is deduced. It turns out that the most appropriate geometric structure that one should consider is the convex hull of the values of the order parameter on the causal volumes whose collision gives rise to the defect. We explain why these two approaches lead to similar results when calculating the density of global defects by using a theorem of Cheeger and Gromoll. We present a computation of the probability of formation of strings/vortices in the case of a system, such as nematic liquid crystals, whose vacuum is $\\mathbb{R}P^2$.

Anthony J. Creaco; Nikos Kalogeropoulos

2008-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

New Composite Silicon-Defect Graphene Anode Architecture  

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

A New Composite Silicon-Defect Graphene Anode Architecture for High Capacity, High-Rate Li-ion Batteries Xin Zhao, Cary Hayner, Mayfair Kung, and Harold Kung, Northwestern...

242

RIS-M-2478 ELECTRICAL CONDUCTIVITY, DEFECT STRUCTURE AND  

E-Print Network (OSTI)

BACKGROUND 7 THEORY 8 MODEL FOR CALCULATION OF THEORETICAL DENSITY IN THE SYSTEM 10 EXPERIMENTAL 12 sensors, fuel c e l l s and electrolyzers. The defect responsible for the high conductivity

243

Built-In Self Test (BIST) for Realistic Delay Defects  

E-Print Network (OSTI)

Testing of delay defects is necessary in deep submicron (DSM) technologies. High coverage delay tests produced by automatic test pattern generation (ATPG) can be applied during wafer and package tests, but are difficult to apply during the board...

Tamilarasan, Karthik Prabhu

2012-02-14T23:59:59.000Z

244

Effects of Compositional Defects on Small Polaron Hopping in...  

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

(ET) theory were used to model the effects of compositional defects on ET in the brucite-like octahedral sheet of mica. ET was modeled as a FeIIIII valence interchange...

245

Defects and impurities in graphene-like materials  

E-Print Network (OSTI)

Graphene-like materials could be used in the fabrication of electronic and optoelectronic devices, gas sensors, biosensors, and batteries for energy storage. Since it is almost impossible to work with defect-free or ...

Terrones, Mauricio

246

Design and optimization of a defect tolerant processor array  

E-Print Network (OSTI)

In this thesis we design and optimization of a defect tolerant MIMD processor array, for maximum performance per wafer area, targeted at applications that have a large number of operations per memory word, is described. The optimization includes...

Lakkapragada, Bhavani S

2012-06-07T23:59:59.000Z

247

Method and apparatus for inspecting reflection masks for defects  

DOE Patents (OSTI)

An at-wavelength system for extreme ultraviolet lithography mask blank defect detection is provided. When a focused beam of wavelength 13 nm is incident on a defective region of a mask blank, three possible phenomena can occur. The defect will induce an intensity reduction in the specularly reflected beam, scatter incoming photons into an off-specular direction, and change the amplitude and phase of the electric field at the surface which can be monitored through the change in the photoemission current. The magnitude of these changes will depend on the incident beam size, and the nature, extent and size of the defect. Inspection of the mask blank is performed by scanning the mask blank with 13 nm light focused to a spot a few .mu.m in diameter, while measuring the reflected beam intensity (bright field detection), the scattered beam intensity (dark-field detection) and/or the change in the photoemission current.

Bokor, Jeffrey (Oakland, CA); Lin, Yun (Berkeley, CA)

2003-04-29T23:59:59.000Z

248

COMMUNICATION Escherichia coli tatC Mutations that Suppress Defective  

E-Print Network (OSTI)

COMMUNICATION Escherichia coli tatC Mutations that Suppress Defective Twin-Arginine Transporter@che.utexas.edu. Abbreviations used: Tat, twin-arginine translocation; MBP, maltose-binding protein; GFP, green fluorescence

Georgiou, George

249

Defect passivation using ultrasound treatment: fundamentals and application  

Science Journals Connector (OSTI)

Ultrasonic vibrations introduced into semiconductor thin-films can trigger defect reactions, which are beneficial for electronic materials and devices. This type of semiconductor processing is assigned as ultraso...

S. Ostapenko

1999-08-01T23:59:59.000Z

250

Multi-Saft: A Flexible Method for Defect Characterization  

Science Journals Connector (OSTI)

Another method in development is the synthetic aperture focusing technique (SAFT). SAFT2 is capable of sizing and localization of defects in three dimensions. Furthermore SAFT can be used for classification of th...

Peter Paul vant Veen; Machteid de Kroon

1996-01-01T23:59:59.000Z

251

Graphene materials having randomly distributed two-dimensional structural defects  

SciTech Connect

Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

2013-10-08T23:59:59.000Z

252

Automated defect spatial signature analysis for semiconductor manufacturing process  

DOE Patents (OSTI)

An apparatus and method for performing automated defect spatial signature alysis on a data set representing defect coordinates and wafer processing information includes categorizing data from the data set into a plurality of high level categories, classifying the categorized data contained in each high level category into user-labeled signature events, and correlating the categorized, classified signature events to a present or incipient anomalous process condition.

Tobin, Jr., Kenneth W. (Harriman, TN); Gleason, Shaun S. (Knoxville, TN); Karnowski, Thomas P. (Knoxville, TN); Sari-Sarraf, Hamed (Knoxville, TN)

1999-01-01T23:59:59.000Z

253

Examples of embedded defects (in particle physics and condensed matter)  

Science Journals Connector (OSTI)

We present a series of examples designed to clarify the formalism of the previous paper. After summarizing this formalism in a prescriptive sense, we run through several examples: first, deriving the embedded defect spectrum for the Weinberg-Salam theory, then discussing several examples designed to illustrate facets of the formalism. We then calculate the embedded defect spectrum for three physical grand unified theories and conclude with a discussion of vortices formed in the superfluid 3He-A phase transition.

Nathan F. Lepora and Anne-Christine Davis

1998-11-23T23:59:59.000Z

254

Dark matter from cosmic defects on galactic scales?  

SciTech Connect

We discuss the possible dynamical role of extended cosmic defects on galactic scales, specifically focusing on the possibility that they may provide the dark matter suggested by the classical problem of galactic rotation curves. We emphasize that the more standard defects (such as Goto-Nambu strings) are unsuitable for this task but show that more general models (such as transonic wiggly strings) could in principle have a better chance. In any case, we show that observational data severely restricts any such scenarios.

Guerreiro, N.; Carvalho, J. P. M. de [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Departamento de Matematica Aplicada da, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007, Porto (Portugal); Avelino, P. P. [Centro de Fisica do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Fisica da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Martins, C. J. A. P. [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2008-09-15T23:59:59.000Z

255

The influence of TiSi2 and CoSi2 growth on Si native point defects: The role of the diffusing species  

E-Print Network (OSTI)

from codeposited metal and Si. The as-deposited films had the compositions Ti, TiSi0.8 , TiSi2 undersaturation.3 Nevertheless, the mechanism by which silicide films effect a perturbance in the point defect, causing a va- cancy supersaturation. The formation of CoSi2 from CoSi proceeds via diffusion of metal

Florida, University of

256

Center for Geologic Storage of CO2 (GSCO2) | U.S. DOE Office...  

Office of Science (SC) Website

in industry-sponsored applied research. Research Topics defects, mechanical behavior, carbon sequestration Materials Studied Materials: porous Interfaces: gasliquid, gas...

257

Mechanical memory  

DOE Patents (OSTI)

A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

Gilkey, Jeffrey C. (Albuquerque, NM); Duesterhaus, Michelle A. (Albuquerque, NM); Peter, Frank J. (Albuquerque, NM); Renn, Rosemarie A. (Albuquerque, NM); Baker, Michael S. (Albuquerque, NM)

2006-05-16T23:59:59.000Z

258

Mechanical memory  

DOE Patents (OSTI)

A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

Gilkey, Jeffrey C. (Albuquerque, NM); Duesterhaus, Michelle A. (Albuquerque, NM); Peter, Frank J. (Albuquerque, NM); Renn, Rosemarie A. (Alburquerque, NM); Baker, Michael S. (Albuquerque, NM)

2006-08-15T23:59:59.000Z

259

LONGTIME ASYMPTOTIC BEHAVIOR OF DISSIPATIVE BOUSSINESQ SYSTEMS  

E-Print Network (OSTI)

equations, such as the KdV and BBM equations, holds for some of the damped Boussinesq systems. 1LONG­TIME ASYMPTOTIC BEHAVIOR OF DISSIPATIVE BOUSSINESQ SYSTEMS M. CHEN 1 AND O. GOUBET 2 1 various dissipative mechanics asso­ ciated with the Boussinesq systems which model two­dimensional small

Chen, Min

260

Defect studies in low-temperature-grown GaAs  

SciTech Connect

High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V{sub Ga}. The neutral AsGa-related defects were measured by infrared absorption at 1{mu}m. Gallium vacancies, V{sub Ga}, was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10{sup 19} cm{sup {minus}3} Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As{sub Ga} in the layer. As As{sub Ga} increases, photoquenchable As{sub Ga} decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As{sub Ga} content around 500C, similar to irradiation damaged and plastically deformed Ga{sub As}, as opposed to bulk grown GaAs in which As{sub Ga}-related defects are stable up to 1100C. The lower temperature defect removal is due to V{sub Ga} enhanced diffusion of As{sub Ga} to As precipitates. The supersaturated V{sub GA} and also decreases during annealing. Annealing kinetics for As{sub Ga}-related defects gives 2.0 {plus_minus} 0.3 eV and 1.5 {plus_minus} 0.3 eV migration enthalpies for the As{sub Ga} and V{sub Ga}. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As{sub Ga}-related defects anneal with an activation energy of 1.1 {plus_minus} 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As{sub Ga}-Be{sub Ga} pairs. Si donors can only be partially activated.

Bliss, D.E.

1992-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Defect studies in low-temperature-grown GaAs  

SciTech Connect

High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V[sub Ga]. The neutral AsGa-related defects were measured by infrared absorption at 1[mu]m. Gallium vacancies, V[sub Ga], was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10[sup 19] cm[sup [minus]3] Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As[sub Ga] in the layer. As As[sub Ga] increases, photoquenchable As[sub Ga] decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As[sub Ga] content around 500C, similar to irradiation damaged and plastically deformed Ga[sub As], as opposed to bulk grown GaAs in which As[sub Ga]-related defects are stable up to 1100C. The lower temperature defect removal is due to V[sub Ga] enhanced diffusion of As[sub Ga] to As precipitates. The supersaturated V[sub GA] and also decreases during annealing. Annealing kinetics for As[sub Ga]-related defects gives 2.0 [plus minus] 0.3 eV and 1.5 [plus minus] 0.3 eV migration enthalpies for the As[sub Ga] and V[sub Ga]. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As[sub Ga]-related defects anneal with an activation energy of 1.1 [plus minus] 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As[sub Ga]-Be[sub Ga] pairs. Si donors can only be partially activated.

Bliss, D.E.

1992-11-01T23:59:59.000Z

262

Context-based automated defect classification system using multiple morphological masks  

DOE Patents (OSTI)

Automatic detection of defects during the fabrication of semiconductor wafers is largely automated, but the classification of those defects is still performed manually by technicians. This invention includes novel digital image analysis techniques that generate unique feature vector descriptions of semiconductor defects as well as classifiers that use these descriptions to automatically categorize the defects into one of a set of pre-defined classes. Feature extraction techniques based on multiple-focus images, multiple-defect mask images, and segmented semiconductor wafer images are used to create unique feature-based descriptions of the semiconductor defects. These feature-based defect descriptions are subsequently classified by a defect classifier into categories that depend on defect characteristics and defect contextual information, that is, the semiconductor process layer(s) with which the defect comes in contact. At the heart of the system is a knowledge database that stores and distributes historical semiconductor wafer and defect data to guide the feature extraction and classification processes. In summary, this invention takes as its input a set of images containing semiconductor defect information, and generates as its output a classification for the defect that describes not only the defect itself, but also the location of that defect with respect to the semiconductor process layers.

Gleason, Shaun S. (Knoxville, TN); Hunt, Martin A. (Knoxville, TN); Sari-Sarraf, Hamed (Lubbock, TX)

2002-01-01T23:59:59.000Z

263

Electroluminescence from isolated defects in zinc oxide, towards electrically triggered single photon sources at room temperature  

E-Print Network (OSTI)

Single photon sources are required for a wide range of applications in quantum information science, quantum cryptography and quantum communications. However, so far majority of room temperature emitters are only excited optically, which limits their proper integration into scalable devices. In this work, we overcome this limitation and present room temperature electrically triggered light emission from localized defects in zinc oxide (ZnO) nanoparticles and thin films. The devices emit at the red spectral range and show excellent rectifying behavior. The emission is stable over an extensive period of time, providing an important prerequisite for practical devices. Our results open up possibilities to build new ZnO based quantum integrated devices that incorporate solid-state single photon sources for quantum information technologies.

Choi, Sumin; Gentle, Angus; Ton-That, Cuong; Phillips, Matthew R; Aharonovich, Igor

2015-01-01T23:59:59.000Z

264

Defects and persistent conductivity in SrTiO{sub 3}  

SciTech Connect

Strontium titanate (SrTiO{sub 3}) is often used as a substrate for oxide thin films such as high-temperature superconductors. It has the perovskite structure and an indirect band gap of 3.25 eV. Our prior work showed that hydrogen impurities form a defect complex that contains two hydrogen atoms. The complex was tentatively attributed to a passivated strontium vacancy. Alternatively, it could be a partially passivated titanium vacancy. In order to create titanium vacancies, we annealed samples in an evacuated ampoule with SrO powder. These samples show unexpected behavior. After illuminating with sub-gap light, the free-electron concentration increases significantly. After the light is turned off, the high conductivity persists at room temperature. We attribute persistent photoconductivity (PPC) to the excitation of an electron from a vacancy into the conduction band, with a low recapture rate.

McCluskey, Matthew D.; Tarun, Marianne C. [Department of Physics and Astronomy, Washington State University, Pullman, WA 99164-2814 (United States)

2014-02-21T23:59:59.000Z

265

Mechanical Analysis of the Nb3Sn Dipole Magnet HD1  

E-Print Network (OSTI)

7] J. Strait, et al. , Mechanical behavior of Fermilab-9] J. Buckley, et al. , Mechanical performance of a twin-S. Caspi, et al. , Mechanical design of a second generation

Ferracin, Paolo

2008-01-01T23:59:59.000Z

266

Regulation mechanisms in spatial stochastic development models  

E-Print Network (OSTI)

The aim of this paper is to analyze different regulation mechanisms in spatial continuous stochastic development models. We describe the density behavior for models with global mortality and local establishment rates. We prove that the local self-regulation via a competition mechanism (density dependent mortality) may suppress a unbounded growth of the averaged density if the competition kernel is superstable.

Dmitri Finkelshtein; Yuri Kondratiev

2008-09-04T23:59:59.000Z

267

Fracture mechanics of cellular glass  

SciTech Connect

Cellular glasses are prime candidate materials for the structural substrate of mirrored glass for solar concentrator reflecting panels. These materials are brittle, however, and susceptible to mechanical failure from slow crack growth caused by a stress corrosion mechanism. The results are detailed of one part of a program established to develop improved cellular glasses and to characterize the behavior of these and commercially available materials. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials are developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region I may be slower, by orders of magnitude, than that found in dense glasses.

Zwissler, J.G.; Adams, M.A.

1981-02-01T23:59:59.000Z

268

Elliot-Yafet Mechanism in Graphene  

Science Journals Connector (OSTI)

The differences between spin relaxation in graphene and in other materials are discussed. For relaxation by scattering processes, the Elliot-Yafet mechanism, the relation between the spin and the momentum scattering times, acquires a dependence on the carrier density, which is independent of the scattering mechanism and the relation between mobility and carrier concentration. This dependence puts severe restrictions on the origin of the spin relaxation in graphene. The density dependence of the spin relaxation allows us to distinguish between ordinary impurities and defects which modify locally the spin-orbit interaction.

H. Ochoa; A. H. Castro Neto; F. Guinea

2012-05-17T23:59:59.000Z

269

Fire tests on defective tank-car thermal protection systems  

Science Journals Connector (OSTI)

Many railway tank-cars carrying hazardous materials are thermally protected from fire impingement by thermal insulation and a steel jacket applied to the outside of the tank-car shell. Over time, it is possible that the thermal insulation will sag, rip, degrade, or be crushed under the steel jacket. A thermographic technique to determine whether or not a tank has insulation deficiencies has been developed, but it is necessary to determine which thermal deficiencies do not affect a tanks survivability in a fire and which thermal deficiencies must be repaired. In order to develop a guideline in assessing thermal defects, a thermal model and experimental data would be beneficial. A series of fire tests were performed on a quarter-section tank-car mock-up to assist in developing a guideline and to provide validation data for a thermal model. Twelve fire tests, with constant, credible, simulated pool fire conditions, were performed on the tank-car mock-up with various insulation deficiencies. An infrared thermal imaging camera was used to measure the tank wall temperature. The thermal images were useful in determining the temperature profiles across the defects at different times and the transient temperature behaviour at different locations. It was seen that the properly installed thermal protection system significantly reduced the heat transfer from the fire to the tank wall. It was also seen that the steel jacket alone (i.e. 100% defect) acted as a radiation shield and provided a significant level of protection. With small defects, it was observed that the surrounding protected material provided a cooling effect by thermal conduction. A square defect greater than about 40 cm on each side should be considered significant, because unlike smaller defects, there is little benefit from the surrounding material as far as the peak defect temperature is concerned.

J.D.J VanderSteen; A.M Birk

2003-01-01T23:59:59.000Z

270

Non-IIDness Learning in Behavioral and Social Data  

Science Journals Connector (OSTI)

......working mechanisms and driving forces of the system dynamics and...Coupled behaviors play a more fundamental role than individuals in the...Roane, H. (eds.) (2011) Handbook of Applied Behavior Analysis...Social Network Analysis: A Handbook. Sage Publications, Newbury......

Longbing Cao

2014-09-01T23:59:59.000Z

271

Analysis of thermomechanical and failure behavior of refractory linings in a high temperature black liquor gasifier .  

E-Print Network (OSTI)

??"A coupled thermal-mechanical model accounting for chemical reaction is developed and implemented into a commercial finite element code to simulate the operational behavior of a (more)

Liang, Xiaoting, 1975-

2005-01-01T23:59:59.000Z

272

Mechanical Property Data for Fiberboard  

SciTech Connect

The 9975 shipping package incorporates a cane fiberboard overpack for thermal insulation and impact resistance. Mechanical properties (tensile and compressive behavior) have been measured on cane fiberboard and a similar wood-based product following short-term conditioning in several temperature/humidity environments. Both products show similar trends, and vary in behavior with material orientation, temperature and humidity. A memory effect is also seen in that original strength values are only partially recovered following exposure to a degrading environment and return to ambient conditions.

WILLIAM, daugherty

2004-12-14T23:59:59.000Z

273

Computational mechanics  

SciTech Connect

The Computational Mechanics thrust area sponsors research into the underlying solid, structural and fluid mechanics and heat transfer necessary for the development of state-of-the-art general purpose computational software. The scale of computational capability spans office workstations, departmental computer servers, and Cray-class supercomputers. The DYNA, NIKE, and TOPAZ codes have achieved world fame through our broad collaborators program, in addition to their strong support of on-going Lawrence Livermore National Laboratory (LLNL) programs. Several technology transfer initiatives have been based on these established codes, teaming LLNL analysts and researchers with counterparts in industry, extending code capability to specific industrial interests of casting, metalforming, and automobile crash dynamics. The next-generation solid/structural mechanics code, ParaDyn, is targeted toward massively parallel computers, which will extend performance from gigaflop to teraflop power. Our work for FY-92 is described in the following eight articles: (1) Solution Strategies: New Approaches for Strongly Nonlinear Quasistatic Problems Using DYNA3D; (2) Enhanced Enforcement of Mechanical Contact: The Method of Augmented Lagrangians; (3) ParaDyn: New Generation Solid/Structural Mechanics Codes for Massively Parallel Processors; (4) Composite Damage Modeling; (5) HYDRA: A Parallel/Vector Flow Solver for Three-Dimensional, Transient, Incompressible Viscous How; (6) Development and Testing of the TRIM3D Radiation Heat Transfer Code; (7) A Methodology for Calculating the Seismic Response of Critical Structures; and (8) Reinforced Concrete Damage Modeling.

Goudreau, G.L.

1993-03-01T23:59:59.000Z

274

Subcritical percolation with a line of defects  

E-Print Network (OSTI)

We consider the Bernoulli bond percolation process $\\mathbb{P}_{p,p'}$ on the nearest-neighbor edges of $\\mathbb{Z}^d$, which are open independently with probability $pp_c'$. Moreover, $p_c'(p,2)=p_c'(p,3)=p$, and $p_c'(p,d)>p$ for $d\\geq 4$. We also analyze the behavior of $\\xi_p-\\xi_{p,p'}$ as $p'\\downarrow p_c'$ in dimensions $d=2,3$. Finally, we prove that when $p'>p_c'$, the following purely exponential asymptotics holds: \\[\\mathbb {P}_{p,p'}(0\\leftrightarrow n\\mathbf {e}_1)=\\psi_de^{-\\xi_{p,p'}n}\\bigl(1+o(1)\\bigr)\\] for some constant $\\psi_d=\\psi_d(p,p')$, uniformly for large values of $n$. This work gives the first results on the rigorous analysis of pinning-type problems, that go beyond the effective models and don't rely on exact computations.

S. Friedli; D. Ioffe; Y. Velenik

2013-07-08T23:59:59.000Z

275

Invisible surface defects in a tight-binding lattice  

E-Print Network (OSTI)

Surface Tamm states arise in one-dimensional lattices from some defects at the lattice edge and their energy generally falls in a gap of the crystal. The defects at the surface change rather generally the phase of propagative Bloch waves scattered off at the lattice edge, so that an observer, far from the surface, can detect the existence of edge defects from e.g. time-of-flight measurements as a delay or an advancement of a Bloch wave packet. Here we show that a special class of defects can sustain surface Tamm states which are invisible, in a sense that reflected waves acquire the same phase as in a fully homogeneous lattice with no surface state. Surface states have an energy embedded into the tight-binding lattice band and show a lower than exponential (algebraic) localization. Like most of bound states in the continuum of von Neumann - Wigner type, such states are fragile and decay into resonance surface states in presence of perturbations or lattice disorder. The impact of structural lattice imperfections and disorder on the invisibility of the defects is investigated by numerical simulations.

Stefano Longhi

2014-06-24T23:59:59.000Z

276

Deformation behavior of laser welds in high temperature oxidation resistant FeCrAl alloys for fuel cladding applications  

Science Journals Connector (OSTI)

Abstract Ferritic-structured FeCrAl alloys are being developed and show promise as oxidation resistant accident tolerant light water reactor fuel cladding. This study focuses on investigating the weldability and post-weld mechanical behavior of three model alloys in a range of Fe(1317.5)Cr(34.4)Al (wt.%) with a minor addition of yttrium using modern laser-welding techniques. A detailed study on the mechanical performance of bead-on-plate welds using sub-sized, flat dog-bone tensile specimens and digital image correlation (DIC) has been carried out to determine the performance of welds as a function of alloy composition. Results indicated a reduction in the yield strength within the fusion zone compared to the base metal. Yield strength reduction was found to be primarily constrained to the fusion zone due to grain coarsening with a less severe reduction in the heat affected zone. For all proposed alloys, laser welding resulted in a defect free weld devoid of cracking or inclusions.

Kevin G. Field; Maxim N. Gussev; Yukinori Yamamoto; Lance L. Snead

2014-01-01T23:59:59.000Z

277

Rate-dependent deformation behavior of poss-filled and plasticized poly(vinyl chloride)  

E-Print Network (OSTI)

Polymers are known to exhibit strong time-dependent mechanical behavior. In different temperatures or frequency regimes, the rate sensitivities of polymers change as various primary and secondary molecular mobility mechanisms ...

Soong, Sharon Yu-Wen

2007-01-01T23:59:59.000Z

278

Proceedings of NAMRI/SME, Vol. 41, 2013 Removal Mechanism and Defect Characterization for Glass-  

E-Print Network (OSTI)

Te, solar cell INTRODUCTION Thin-film solar cell technology promises to achieve a significant cost reduction- Side Laser Scribing of CdTe/CdS Multilayer in Solar Cells Hongliang Wang, Y. Lawrence Yao Department to reduce photocurrent and resistance losses and increase solar cell efficiency through the formation

Yao, Y. Lawrence

279

Deformation Behavior of Sub-micron and Micron Sized Alumina Particles in Compression.  

SciTech Connect

The ability to integrate ceramics with other materials has been limited due to high temperature (>800degC) ceramic processing. Recently, researchers demonstrated a novel process , aerosol deposition (AD), to fabricate ceramic films at room temperature (RT). In this process, sub - micro n sized ceramic particles are accelerated by pressurized gas, impacted on the substrate, plastically deformed, and form a dense film under vacuum. This AD process eliminates high temperature processing thereby enabling new coatings and device integration, in which ceramics can be deposited on metals, plastics, and glass. However, k nowledge in fundamental mechanisms for ceramic particle s to deform and form a dense ceramic film is still needed and is essential in advancing this novel RT technology. In this wo rk, a combination of experimentation and atomistic simulation was used to determine the deformation behavior of sub - micron sized ceramic particle s ; this is the first fundamental step needed to explain coating formation in the AD process . High purity, singl e crystal, alpha alumina particles with nominal size s of 0.3 um and 3.0 um were examined. Particle characterization, using transmission electron microscopy (TEM ), showed that the 0.3 u m particles were relatively defect - free single crystals whereas 3.0 u m p articles were highly defective single crystals or particles contained low angle grain boundaries. Sub - micron sized Al 2 O 3 particles exhibited ductile failure in compression. In situ compression experiments showed 0.3um particles deformed plastically, fractured, and became polycrystalline. Moreover, dislocation activit y was observed within the se particles during compression . These sub - micron sized Al 2 O 3 particles exhibited large accum ulated strain (2 - 3 times those of micron - sized particles) before first fracture. I n agreement with the findings from experimentation , a tomistic simulation s of nano - Al 2 O 3 particles showed dislocation slip and significant plastic deformation during compressi on . On the other hand, the micron sized Al 2 O 3 particles exhibited brittle f racture in compression. In situ compression experiments showed 3um Al 2 O 3 particles fractured into pieces without observable plastic deformation in compression. Particle deformation behaviors will be used to inform Al 2 O 3 coating deposition parameters and particle - particle bonding in the consolidated Al 2 O 3 coatings.

Sarobol, Pylin; Chandross, Michael E.; Carroll, Jay; Mook, William; Boyce, Brad; Kotula, Paul G.; McKenzie, Bonnie B.; Bufford, Daniel Charles; Hall, Aaron Christopher.

2014-09-01T23:59:59.000Z

280

Mechanical Vibration  

Science Journals Connector (OSTI)

... THE suppression and control of mechanical vibration have assumed great importance in engineering. One consequence of this is that the number ... degree of emphasis is placed on transient oscillation (in addition to steady-State and free vibration). The treatment of this topic is based mainly on phase-plane constructions and it ...

R. E. D. BISHOP

1958-12-06T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" from the National Library of EnergyBeta (NLEBeta).
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281

Additive manufacturing for in situ repair of osteochondral defects  

Science Journals Connector (OSTI)

Tissue engineering holds great promise for injury repair and replacement of defective body parts. While a number of techniques exist for creating living biological constructs in vitro, none have been demonstrated for in situ repair. Using novel geometric feedback-based approaches and through development of appropriate printing-material combinations, we demonstrate the in situ repair of both chondral and osteochondral defects that mimic naturally occurring pathologies. A calf femur was mounted in a custom jig and held within a robocasting-based additive manufacturing (AM) system. Two defects were induced: one a cartilage-only representation of a grade IV chondral lesion and the other a two-material bone and cartilage fracture of the femoral condyle. Alginate hydrogel was used for the repair of cartilage; a novel formulation of demineralized bone matrix was used for bone repair. Repair prints for both defects had mean surface errors less than 0.1 mm. For the chondral defect, 42.8 2.6% of the surface points had errors that were within a clinically acceptable error range; however, with 1 mm path planning shift, an estimated ~75% of surface points could likely fall within the benchmark envelope. For the osteochondral defect, 83.6 2.7% of surface points had errors that were within clinically acceptable limits. In addition to implications for minimally invasive AM-based clinical treatments, these proof-of-concept prints are some of the only in situ demonstrations to-date, wherein the substrate geometry was unknown a priori. The work presented herein demonstrates in situ AM, suggests potential biomedical applications and also explores in situ-specific issues, including geometric feedback, material selection and novel path planning techniques.

Daniel L Cohen; Jeffrey I Lipton; Lawrence J Bonassar; Hod Lipson

2010-01-01T23:59:59.000Z

282

Defect microstructural evolution in ion irradiated metallic nanofoils: Kinetic Monte Carlo simulation versus cluster dynamics modeling and in situ transmission electron microscopy experiments  

SciTech Connect

Understanding materials degradation under intense irradiation is important for the development of next generation nuclear power plants. Here we demonstrate that defect microstructural evolution in molybdenum nanofoils in situ irradiated and observed on a transmission electron microscope can be reproduced with high fidelity using an object kinetic Monte Carlo (OKMC) simulation technique. Main characteristics of defect evolution predicted by OKMC, namely, defect density and size distribution as functions of foil thickness, ion fluence and flux, are in excellent agreement with those obtained from the in situ experiments and from previous continuum-based cluster dynamics modeling. The combination of advanced in situ experiments and high performance computer simulation/modeling is a unique tool to validate physical assumptions/mechanisms regarding materials response to irradiation, and to achieve the predictive power for materials stability and safety in nuclear facilities.

Xu Donghua; Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Li Meimei [Division of Nuclear Engineering, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kirk, Marquis A. [Division of Materials Science, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2012-09-03T23:59:59.000Z

283

Sub-degree Scale Microwave Anisotropies from Cosmic Defects  

E-Print Network (OSTI)

If current ideas about unified field theories are correct, macroscopic cosmic defects may well exist. The observation of such an entity would have enormous significance for our understanding of fundamental physics. This paper points out a novel observable signature of cosmic texture and global monopoles, namely strong hot spots in the cosmic microwave anisotropy pattern on subdegree scales. This signal should be readily detectable by the next generation of anisotropy mapping experiments. The signature arises from overdensities in the photon-baryon fluid generated by the gravitational attraction of the defects. The angular power spectrum of the anisotropy fluctuations on subdegree scales is also calculated, for cosmic string, global monopoles, and texture.

Neil Turok

1996-06-16T23:59:59.000Z

284

On the material geometry of continuously defective corrugated graphene sheets  

E-Print Network (OSTI)

Geometrical objects describing the material geometry of continuously defective graphene sheets are introduced and their compatibility conditions are formulated. Effective edge dislocations embedded in the Riemann-Cartan material space and defined by their scalar density and by local Burgers vectors, are considered. The case of secondary curvature-type defects created by this distribution of dislocations is analysed in terms of the material space. The variational geometry of the material space closely related with the existence of a characteristic length parameter is proposed. The formula which describes, in a reference temperature, the influence of dislocations on the material Riemannian metric, is given.

Andrzej Trzesowski

2014-07-05T23:59:59.000Z

285

On the defect induced gauge and Yukawa fields in graphene  

E-Print Network (OSTI)

We consider lattice deformations (both continuous and topological) in the hexagonal lattice Hubbard model in the tight binding approximation to graphene, involving operators with the range up to next-to-neighbor. In the low energy limit, we find that these deformations give rise to couplings of the electronic Dirac field to an external scalar (Yukawa) and gauge fields. The fields are expressed in terms of original defects. As a by-product we establish that the next-to-nearest order is the minimal range of deformations which produces the complete gauge and scalar fields. We consider an example of Stone--Wales defect, and find the associated gauge field.

Corneliu Sochichiu

2010-12-24T23:59:59.000Z

286

Probabilistic timed behavior trees  

Science Journals Connector (OSTI)

The Behavior Tree notation has been developed as a method for systematically and traceably capturing user requirements. In this paper we extend the notation with probabilistic behaviour, so that reliability, performance, and other dependability properties ... Keywords: behavior trees, model checking, probabilities, timed automata

Robert Colvin; Lars Grunske; Kirsten Winter

2007-07-01T23:59:59.000Z

287

Growth strains and creep in thermally grown alumina : oxide growth mechanisms.  

SciTech Connect

In situ measurements of growth strains and creep relaxation in {alpha}-Al{sub 2}O{sub 3} films, isothermally grown on {beta}-NiAl alloys at 1100 C, are reported and analyzed. Samples containing the reactive element Zr, and Zr-free samples, are examined. For Zr-free samples, steady state growth strains are compressive, whereas the growth strains are tensile when the reactive element (RE) is added to the alloy. This behavior is attributed to the counterflow of oxygen and aluminum interstitials, and to simultaneous counterflow of oxygen and aluminum vacancies, all moving through the grain boundaries. Cross diffusing oxygen and aluminum interstitials may merge and combine within the film, forming new oxide along grain boundary walls, a mechanism that leads to an in-plane compressive stress. Cross diffusing oxygen and aluminum vacancies will also merge and combine within the film; in this case material is removed from grain boundary walls, a mechanism that leads to an in-plane tensile stress. When no RE is present, the interstitial mechanism dominates and the resultant stress is compressive. Consistent with the 'dynamic segregation model', the RE slows the outdiffusion of Al interstitials permitting the tensile mechanism to dominate. This interpretation invokes the unconventional view that oxygen and aluminum interstitials and vacancies, created in and driven by the strong chemical gradient, all participate meaningfully in the scale growth process. Grain boundary diffusion measurements were obtained from low stress creep data, interpreted using the Coble model of grain boundary diffusion. Reported diffusion measurements of oxygen through grain boundaries of {alpha}-Al{sub 2}O{sub 3}, which are known to be inconsistent with oxide scale growth, are critically examined. A simple picture, a 'balanced defect model', emerges that is consistent with the dynamic segregation model, observed growth stresses and their dependence on the presence of a reactive element, sequential oxidation experiments, and our best knowledge about grain boundary diffusion coefficients.

Veal, B. W.; Paulikas, A. P.; Materials Science Division

2008-01-01T23:59:59.000Z

288

Native defects in tetradymite Bi2(TexSe3-x) topological insulators  

SciTech Connect

Formation energies of native defects in Bi2(TexSe3-x), with comparison to ideal Bi2Te2S, are calculated in density-functional theory to assess transport properties. Bi2Se3 is found to be n type for both Bi- and Se-rich growth conditions, while Bi2Te3 changes from n to p type going from Te- to Bi-rich conditions, as observed. Bi2Te2Se and Bi2Te2S are generally n type, explaining observed heavily doped n-type behavior in most samples. A (0/-) transition level at 16 meV above valence-band maximum for Bi on Te antisites in Bi2Te2Se is related to the observed thermally active transport gap causing a p-to-n transition at low temperature. Bi2(TexSe3-x) with x>2 are predicted to have high bulk resistivity due to effective carrier compensation when approaching the n-to-p crossover. Predicted behaviors are confirmed from characterization of our grown single crystals.

Wang, Lin-Lin [Ames Laboratory; Huang, Mianliang [South Dakota School of Mines; Thimmaiah, Srinivasa [Ames Laboratory; Alam, Aftab [Ames Laboratory; Budko, Sergey L. [Ames Laboratory; Kaminski, Adam [Ames Laboratory; Lograsso, Thomas A. [Ames Laboratory; Canfield, Paul [Ames Laboratory; Johnson, Duane D. [Ames Laboratory

2013-03-08T23:59:59.000Z

289

Intertemporal Consumption and Savings Behavior: Neoclassical, Behavioral, and Neuroeconomic Approaches  

E-Print Network (OSTI)

Intertemporal Consumption and Savings Behavior: Neoclassical, Behavioral, and Neuroeconomic models of intertemporal consumption and savings behavior. I summarize the construction and implications of Modigliani & Brumberg's Life-Cycle Hypothesis [4] and Laibson's quasi-hyperbolic consumption function [8

Morrow, James A.

290

Measuring Point Defect Density in Individual Carbon Nanotubes Using  

E-Print Network (OSTI)

based on defec- tive nanotubes also show improved sensitivity.7 Recently, high-energy electron and ionMeasuring Point Defect Density in Individual Carbon Nanotubes Using Polarization-Dependent X in carbon nanotubes (CNTs) dramatically alter their physical, mechani- cal, and electronic properties.1

Hitchcock, Adam P.

291

Convergence properties of the local defect correction method for parabolic  

E-Print Network (OSTI)

and, for a one-dimensional heat equation, we study its properties analytically. Numerical experiment of adaptive grid techniques. In adaptive grid methods, a fine grid spacing and a relatively small time step requirements are minimized. An adaptive grid technique of particular interest is the Local Defect Correction

Eindhoven, Technische Universiteit

292

Defects and Faults in Quantum Cellular Automata at Nano Scale  

E-Print Network (OSTI)

Defects and Faults in Quantum Cellular Automata at Nano Scale Mehdi Baradaran Tahoori, Mariam considerable research on quantum dot cellular automata (QCA) as a new computing scheme in the nano, quantum dot cellular automata (QCA) not only gives a solution at nano scale, but also it offers a new

293

Defect luminescence in films containing Ge and GeO{sub 2} nanocrystals  

SciTech Connect

Amorphous SiO{sub x} alloys containing Ge or GeO{sub 2} nanocrystals are produced by dc-magnetron sputtering and controlled crystallization. The samples are investigated by Raman scattering, transmission electron microscopy, photoluminescence and excitation spectroscopy. Under UV excitation, both types of films luminesce around 3.1 eV, with identical PL line shapes and subnanosecond PL dynamics. The strongest PL intensity is found for the films containing FeO{sub 2} crystals and for the largest nanocrystals. These results are a clear indication that although the blue luminescence is without a doubt correlated with the formation of Ge (or GeO{sub 2}) nanocrystals, it is not produced by the radiative recombination of excitons confined in the nanocrystals. Possible mechanisms for the luminescence are discussed, including defects at the nanocrystal/matric interface or in the matrix itself.

Zacharias, M.; Atherton, S.J.; Fauchet, P.M.

1997-07-01T23:59:59.000Z

294

High-energy mechanical synthesis of nanophase fluorite-structured mixed oxide catalysts with a high redox activity  

SciTech Connect

A series of nanostructured, highly defective, ternary solid solutions containing CeO{sub 2}, ZrO{sub 2}, and MnO{sub 2} or CuO were prepared by high-energy mechanical milling of individual components. Morphological and redox properties were studied by XRD, HRTEM and temperature-programmed reduction techniques. It was shown that the introduction of small amounts of copper and manganese strongly promotes the redox behavior of cerium at lower temperatures in comparison with CeO{sub 2} and CeO{sub 2}-ZrO{sub 2}. High temperature treatment of up to 1,400 K was also shown to further promote overall redox capacity without affecting low-temperature redox behavior. Moreover, evidence is provided to show that Cu and Mn are dissolved within the CeO{sub 2} lattice structure. Addition of dopants enhances catalytic redox properties in the oxidation of CO at low temperatures, which is associated with the high concentration of oxygen vacancies that form on the introduction of aliovalent elements into the ceria-zirconia lattice.

Primavera, A.; Trovarelli, A.; Terribile, D.; Leitenburg, C. de; Dolcetti, G. [Univ. di Udine (Italy). Dipt. di Scienze e Tecnologie Chimiche; Llorca, J. [Univ. de Barcelona (Spain). Dept. de Quimica Inorganica

1997-12-31T23:59:59.000Z

295

Cartel Mechanism Design: Nonratifiable Conditions of Collusive Behavior  

E-Print Network (OSTI)

(b)? b)(n? 1)f(vj(b)) . Substitute in vj(b). vj(b) = b + F (vj(b))[F (vi(b))? F (vN)] (n? 2)f(vj(b))v ? j(b)[F (vi(b))? F (vN)] + F (vj(b))f(vi(b))v ? i(b) = b + F (vi(b))? F (vN) (n?2n?1)( F (vi(b))?F (vN ) vi(b)?b ) + f(vi(b))v?i(b) . (4...) Because the inverse bidding function is monotonic increasing according to b, the relationship is uniquely determined. Define Q(vi(b)) ? vj(vi), where Q(vi(b)) is the 1From Cao and Tian [2], b = max argmaxb F (b)n?1(vN ? b). 16 relationship between vj...

Hsueh, Shao-Chieh

2012-02-14T23:59:59.000Z

296

Neurotoxic mechanisms of methylmercury: cellular and behavior changes  

E-Print Network (OSTI)

The organic or methylated form of mercury (Hg), consisting of one methyl group bound to each atom of Hg, (methylmercury; MeHg), accounts for most of the Hg to which humans are exposed. MeHg, by virtue of its lipophilicity is highly neurotoxic...

Bellum, Sairam

2007-04-25T23:59:59.000Z

297

The normal basilar artery: structural properties and mechanical behavior  

E-Print Network (OSTI)

male White New Zealand specific pathogen free rabbits underwent cyclic pressurization tests at in vivo conditions and controlled levels of myogenic tone. Sections of basilar arteries were imaged for collagen fiber orientation at 0, 40 and 80 mmHg...

Wicker, Bethany Kay

2009-05-15T23:59:59.000Z

298

Mechanical behavior and microstructure of self-assembling oligopeptide gels  

E-Print Network (OSTI)

Hydrogels have become widely used in the fields of tissue engineering and drug delivery. One class of hydrogel is formed from synthetic oligopeptides that self-assemble into a solution of beta-sheet filaments. These filaments ...

Hammond, Nathan Allen

2010-01-01T23:59:59.000Z

299

Thermo-mechanical Behavior of Lithium-ion Battery Electrodes  

E-Print Network (OSTI)

Developing electric vehicles is widely considered as a direct approach to resolve the energy and environmental challenges faced by the human race. As one of the most promising power solutions to electric cars, the lithium ion battery is expected...

An, Kai

2013-11-25T23:59:59.000Z

300

Behavioral mechanisms underlying the extinction of cocaine self-administration  

E-Print Network (OSTI)

Amsel?s general theory of persistence were used to both design and explain various aspects of these models. For Experiment 1, rats self-administered cocaine (0.25, 0.50 or 1.00 mg/kg) intravenously and were then tested in an extinction preparation using...

Valles, Rodrigo, Jr.

2006-04-12T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Dynamic mechanical behavior of multilayer graphene via supersonic projectile penetration  

Science Journals Connector (OSTI)

...are highlighted by green backlight. (D...accompanying the kinetic energy loss of a {mu...smaller penetration energy is measured. Fig...red) and zigzag (green) directions. The circles in...the impact area to energy absorption (27...for MLG (see green squares in Fig. 4C...

Jae-Hwang Lee; Phillip E. Loya; Jun Lou; Edwin L. Thomas

2014-11-28T23:59:59.000Z

302

Low temperature electrical and mechanical behavior of composite aluminum cryoconductors  

E-Print Network (OSTI)

composite can also be theoretically determined using the rule of mixtures. By substituting conductivity for yield strength in equation (7), then inverting, since resistivity is the inverse of conductivity, the total resistivity, p, is PfPm P= ffp + f pf... composite can also be theoretically determined using the rule of mixtures. By substituting conductivity for yield strength in equation (7), then inverting, since resistivity is the inverse of conductivity, the total resistivity, p, is PfPm P= ffp + f pf...

De Frese, Raymond Jack

2012-06-07T23:59:59.000Z

303

Exploring Nonlinear Behavior  

Science Journals Connector (OSTI)

The point at which modeling gets particularly interesting is when model behavior becomes increasingly nonlinear. It is no coincidence that this is the point where simulation tools start having trouble. Nonline...

Michael Tiller Ph.D.

2001-01-01T23:59:59.000Z

304

Aquifer behavior with reinjection  

E-Print Network (OSTI)

AQUIFER BEHAVIOR WITH REINJECTION A Thesis By EUCLIDES JOSE BONET Submitted to the Graduate College of the Texas ARUM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May, f967 Major Subject... Petroleum Engineering AQUIFER BEHAVIOR WITH REINJECTION A Thesis By E UC LI DES JOSE BONE T Approved as to style and content by: (Chairman of Committee) (Member) (Member) May, 1967 ACKNOWLEDGMENT Thanks are due to Petroleo Brasilerio S...

Bonet, Euclides Jose

1967-01-01T23:59:59.000Z

305

Atomic Computer Simulations of Defect Migration in 3C and 4H...  

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

Computer Simulations of Defect Migration in 3C and 4H-SiC. Atomic Computer Simulations of Defect Migration in 3C and 4H-SiC. Abstract: Knowledge of the migration of intrinsic point...

306

Operating Experience Level 3: Radcalc V4.1 Software Defect |...  

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

OE-3 2011-01: Radcalc V4.1 Software Defect Operating Experience Level 3: Radcalc V4.1 Software Defect More Documents & Publications RADCALC DOE-STD-3013-2012 DOE-HDBK-1129-2007...

307

Phase fluctuations and the absence of topological defects in photo-excited charge ordered nickelate  

E-Print Network (OSTI)

of topological defects in a photo-excited charge-orderedof topological defects in a photo-excited charge-orderedremains unchanged in the photo-excited transient state.

Lee, W.S.

2014-01-01T23:59:59.000Z

308

Identification of structural defects in graphitic materials by gas-phase anisotropic etching  

E-Print Network (OSTI)

Identification of structural defects in graphitic materials by gas-phase anisotropic etching Shuang interest but also industrial importance, as the existence of surface and bulk defects inevitably influences

Zhang, Guangyu

309

Impact of Point Defects on Electronic Structure in YTiO. | EMSL  

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

defect states are available to tune this U value, care must be taken in applying DFT+U to electronic structure calculations of Y&8322;Ti&8322;O&8327; with point defects. Based...

310

Effects of interface bonding and defects on boron diffusion at Si/SiO{sub 2} interface  

SciTech Connect

We perform first-principles density functional calculations to find the migration pathway and barrier for B diffusion at the Si/SiO{sub 2} interface. For various interface models, in which crystalline ?-quartz or amorphous silica (a-SiO{sub 2}) is placed on Si, we examine stable and metastable configurations of B-related defects which play a role in B diffusion. While a substitutional B alone is immobile in Si, it tends to diffuse to the interface via an interstitialcy mechanism in the presence of a self-interstitial and then changes into an interstitial B in oxide via a kick-out mechanism, leaving the self-interstitial at the interface. At the defect-free interface, where bridging O atoms are inserted to remove interface dangling bonds, an interstitial B prefers to intervene between the interface Si and bridging O atoms and subsequently diffuses through the hollow space or along the network of the Si-O-Si bonds in oxide. The overall migration barriers are calculated to be 2.022.12?eV at the Si/?-quartz interface, while they lie in the range of 2.04??0.44?eV at the Si/a-SiO{sub 2} interface, similar to that in ?-quartz. The migration pathway and barrier are not significantly affected by interface defects such as suboxide bond and O protrusion, while dangling bonds in the suboxide region can increase the migration barrier by about 1.5?eV. The result that the interface generally does not hinder the B diffusion from Si to SiO{sub 2} assists in understanding the underlying mechanism for B segregation which commonly occurs at the Si/SiO{sub 2} interface.

Kim, Geun-Myeong; Oh, Young Jun; Chang, K. J., E-mail: kchang@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

2013-12-14T23:59:59.000Z

311

Behavior Based Energy Efficiency (BBEE)  

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

Behavior Based Energy Efficiency Program Profiles 2011 Introduction Behavior based energy efficiency (BBEE) programs focus on energy savings resulting from changes in individual or...

312

1 Semst 8 Semth7 Semth6 Semth5 Semth4 Semth3 Semrd2 Semnd Mechanical and Industrial Engineering Department  

E-Print Network (OSTI)

Engineering MIE 570 Solar & Dir. Energy Conver. MIE 573 Engin. Windpower Systems MIE 597B Mechanical Behavior

Mountziaris, T. J.

313

Indirect selection for plasmid mutants: isolation of ColVBtrp mutants defective in self-maintenance in Escherichia coli.  

Science Journals Connector (OSTI)

...isolation of ColVBtrp mutants defective in self-maintenance in Escherichia...fact, many of the mutants defective in plasmid maintenance were...characterization of strains car- rying mutated plasmids defective in self-main- tenance has...

A H Koyama; C Wada; T Nagata; T Yura

1975-04-01T23:59:59.000Z

314

DISSERTATION Role of the Cu-O Defect in CdTe Solar Cells  

E-Print Network (OSTI)

OF THE CU-O DEFECT COMPLEX IN CDTE SOLAR CELLS Thin-film CdTe is one of the leading materials used the defects present in thin-film CdTe deposited for solar cells. One key defect seen in the thin-film CdDISSERTATION Role of the Cu-O Defect in CdTe Solar Cells Submitted by Caroline R. Corwine

Sites, James R.

315

Changes of defect and active-dopant concentrations induced by annealing of highly Si-doped GaAs  

Science Journals Connector (OSTI)

We identified point defects and dopant atoms and measured their concentrations in as-grown and post-growth annealed highly Si-doped GaAs by scanning tunneling microscopy. The annealing under As atmosphere reduces the concentration of Si atoms incorporated into Si pairs and clusters by cluster dissolution, while the concentrations of Si donors, Si donorGa vacancy complexes, and Si donorAs vacancy complexes increase. For the dissolution of the Si clusters during heat treatment, a Ga-vacancy-mediated mechanism is suggested.

C. Domke, Ph. Ebert, and K. Urban

1998-02-15T23:59:59.000Z

316

Stability of irradiation-induced point defects on walls of carbon nanotubes  

E-Print Network (OSTI)

Stability of irradiation-induced point defects on walls of carbon nanotubes A. V. Krasheninnikov #3 of atomic-scale irradiation- induced defects on walls of carbon nanotubes. Since atomic vacancies. Carbon nanotubes; C. Computational chemistry; Scanning tunneling microscopy; D. Defects; Electronic

Nordlund, Kai

317

Generation of defective virus after infection of newborn rats with reovirus.  

Science Journals Connector (OSTI)

...Research Article Generation of defective virus after infection of newborn...exceptions to this are described. Defective virions lacking the L1 segment...of cells J. VIROL. 4 .4 DEFECTIVE REOVIRUS IN VIVO 243 1? i...other experiments were being car- ried out with A mutants in...

D A Spandidos; A F Graham

1976-10-01T23:59:59.000Z

318

Reduced COX-2 Protein in Colorectal Cancer with Defective Mismatch Repair  

Science Journals Connector (OSTI)

...Protein in Colorectal Cancer with Defective Mismatch Repair 1 1 This work...typic characteristics of defective DNA mismatch repair express...may arise in the setting of defective DNA mismatch repair. INTRODUCTION...sporadic colorectal adenomas and car cinomas (6-7) and in FAP...

William E. Karnes, Jr.; Rebecca Shattuck-Brandt; Lawrence J. Burgart; Raymond N. DuBois; David J. Tester; Julie M. Cunningham; Cheong-Yong Kim; Shannon K. McDonnell; Daniel J. Schaid; and Stephen N. Thibodeau

1998-12-01T23:59:59.000Z

319

Subgenomic mRNA in OK10 Defective Leukemia Virus-Transformed Cells  

Science Journals Connector (OSTI)

...Viruses Subgenomic mRNA in OK10 Defective Leukemia Virus-Transformed...Helsinki 29, Finland OK10, a defective leukemia virus, is produced...transcriptase assay. OK10 defective viral particles were purified...transcriptase assay was then car- ried out as follows: purified...

S. Saule; A. Sergeant; G. Torpier; M. B. Raes; S. Pfeifer; D. Stehelin

1982-04-01T23:59:59.000Z

320

Virulence of Streptococcus mutans: Restoration of Pathogenesis of a Glucosyltransferase-Defective Mutant (C4)  

Science Journals Connector (OSTI)

...an avirulent, aggregation-defective mutant of S. mutans 6715 WT...of pathogenesis of a GTF-defective mutant of S. mutans can be...complementation with a mutant defective in aggregation properties or...humans is undoubedly dental car- ies (24). Streptococcus...

Masatomo Hirasawa; Hiroshi Kiyono; Tetsuo Shiota; Richard A. Hull; Roy Curtiss III; Suzanne M. Michalek; Jerry R. McGhee

1980-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Residual Magnetic Flux Leakage: A Possible Tool for Studying Pipeline Defects  

E-Print Network (OSTI)

Residual Magnetic Flux Leakage: A Possible Tool for Studying Pipeline Defects Vijay Babbar1 weaker flux signals. KEY WORDS: Magnetic flux leakage; residual magnetization; pipeline defects; pipeline pipelines, which may develop defects such as corrosion pits as they age in service.(1) Under the ef- fect

Clapham, Lynann

322

Oxygen sublattice defect in cobalt oxide : formation, migration, charge localization and thermodynamic processes  

E-Print Network (OSTI)

643 Oxygen sublattice defect in cobalt oxide : formation, migration, charge localization of oxygen defects in CoO using classical simulations. The charge localization in the oxygen vacancy has]. The defect concentration in the oxygen sublattice is several orders of magnitude smaller, but never- theless

Paris-Sud XI, Université de

323

Testing the theory of relative defect proneness for closed-source software  

Science Journals Connector (OSTI)

Recent studies on open-source software (OSS) products report that smaller modules are proportionally more defect prone compared to larger ones. This phenomenon, referred to as the Theory of Relative Defect Proneness (RDP), challenges the traditional ... Keywords: Closed---source software, Planning for software quality assurance, Size---defect relationship, Software inspections, Software metrics, Software reviews, Software science, Software testing

Gunes Koru; Hongfang Liu; Dongsong Zhang; Khaled Emam

2010-12-01T23:59:59.000Z

324

Ab Initio Studies of Vacancy-Defected Fullerenes and Single-Walled Carbon  

E-Print Network (OSTI)

Ab Initio Studies of Vacancy-Defected Fullerenes and Single-Walled Carbon Nanotubes LEI VINCENT LIU- vacancy-defected fullerenes, C60 and C70, and the single- and double-vacancy-defected single-walled carbon nanotubes (SWCNTs) were studied within density functional theory. The isomerization barriers for the single-vacancy

Wang, Yan Alexander

325

A simulation model of focus and radial servos in Compact Disc players with Disc surface defects  

E-Print Network (OSTI)

A simulation model of focus and radial servos in Compact Disc players with Disc surface defects P of controllers handling surface defects easier. A simulation model of Compact Disc players playing discs of the controller has been based on trial and error on real test systems since no simulation models of the defects

Wickerhauser, M. Victor

326

Mechanical & Aerospace Engineering  

E-Print Network (OSTI)

Mechanical & Aerospace Engineering An experimental methodology is presented for mechanism verification of physics-based prognosis of mechanical damage, such as fatigue. The proposed experimental methodology includes multi-resolution in-situ mechanical testing, advanced imaging analysis, and mechanism

327

Cation Defects and Conductivity in Transparent Oxides. | EMSL  

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

In this paper, we identify key parameters that promote conductivity in mixed metal spinel oxides and compare their behavior with that of the free carrier TCOs....

328

Extreme ultraviolet induced defects on few-layer graphene  

SciTech Connect

We use Raman spectroscopy to show that exposing few-layer graphene to extreme ultraviolet (EUV, 13.5 nm) radiation, i.e., relatively low photon energy, results in an increasing density of defects. Furthermore, exposure to EUV radiation in a H{sub 2} background increases the graphene dosage sensitivity, due to reactions caused by the EUV induced hydrogen plasma. X-ray photoelectron spectroscopy results show that the sp{sup 2} bonded carbon fraction decreases while the sp{sup 3} bonded carbon and oxide fraction increases with exposure dose. Our experimental results confirm that even in reducing environment oxidation is still one of the main source of inducing defects.

Gao, A.; Zoethout, E.; Lee, C. J. [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands)] [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands); Rizo, P. J.; Scaccabarozzi, L.; Banine, V. [ASML, De Run 6501, 5504DR Veldhoven (Netherlands)] [ASML, De Run 6501, 5504DR Veldhoven (Netherlands); Bijkerk, F. [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands) [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands); MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

2013-07-28T23:59:59.000Z

329

Silicide Schottky Contacts to Silicon: Screened Pinning at Defect Levels  

SciTech Connect

Silicide Schottky contacts can be as large as 0.955 eV (E{sub v} + 0.165 eV) on n-type silicon and as large as 1.05 eV (E{sub c} {minus} 0.07 eV) on p-type silicon. Current models of Schottky barrier formation do not provide a satisfactory explanation of occurrence of this wide variation. A model for understanding Schottky contacts via screened pinning at defect levels is presented. In the present paper it is shown that most transition metal silicides are pinned approximately 0.48 eV above the valence band by interstitial Si clusters. Rare earth disilicides pin close to the divacancy acceptor level 0.41 eV below the conduction band edge while high work function silicides of Ir and Pt pin close to the divacancy donor level 0.21 eV above the valence band edge. Selection of a particular defect pinning level depends strongly on the relative positions of the silicide work function and the defect energy level on an absolute energy scale.

Drummond, T.J.

1999-03-11T23:59:59.000Z

330

Deformation behavior of duplex zircaloy-4-oxygen alloys  

SciTech Connect

Mechanical properties at thermal equilibrium have been determined. The strengthening behavior for alloys having isolated /alpha/ grains in the softer /beta/ matrix is similar to dispersed particle strengthening. Yield strength obeys the Petch relationship. The strength obeys a modified rule of mixtures. Deformation behavior is interpreted in terms of dislocation slip in the /beta/ matrix and diffusion assisted climb near the interphase boundary. 9 refs.

Tseng, D.; Tangri, K.

1982-06-01T23:59:59.000Z

331

Prediction of failure behavior of a welded pressure vessel containing flaws during a hydrogen-charged burst test  

SciTech Connect

An industry-government collaborative program was carried out with an aim to promoting the acceptance of fracture mechanics based fitness-for-service assessment methodology for a service-damaged pressure vessel. A collaborative round robin exercise was carried out to predict the fracture behavior of a vessel containing hydrogen damage, fabrication related lack-of-fusion defects, an artificially induced fatigue crack and a localized thinned area. The fracture assessment procedures used include the US ASME Material Property Council`s PREFIS Program based on the British Standard (BS) Published Document (PD) 6493, ASME Section XI and The Central Electricity Generating Board (CEGB) R6 approach; The welding Institute (TWI) CRACKWISE program (based on BS PD6493 Level 2 approach), a variant of the R6 approach, J-tearing instability approaches, various J-estimation schemes, LEFM approach and simplified stress analysis. Assessments were compared with the results obtained from a hydrogen charged burst test of the vessel. Predictions, based on the J-tearing approach, compared well with the actual burst test results. Actual burst pressure was about five times the operating pressure.

Bhuyan, G.S. [Powertech Labs. Inc., Surrey, British Columbia (Canada); Sperling, E.J. [Amoco Corp., Naperville, IL (United States); Shen, G. [CANMET, Ottawa, Ontario (Canada). Metals Technology Labs.; Yin, H. [Mobil Research and Development Corp., Farmers Branch, TX (United States); Rana, M.D. [Praxair, Inc., Tonawanda, NY (United States)

1996-12-01T23:59:59.000Z

332

Prediction of failure behavior of a welded pressure vessel containing flaws during a hydrogen-charged burst test  

SciTech Connect

An industry-government collaborative program was carried out with an aim to promoting the acceptance of fracture mechanics-based fitness-for-service assessment methodology for a service-damaged pressure vessel. A collaborative round robin exercise was carried out to predict the fracture behavior of a vessel containing hydrogen damage, fabrication-related lack-of-fusion defects, an artificially induced fatigue crack, and a localized thinned area. The fracture assessment procedures used include the US ASME Material Property Council`s PREFIS Program based on the British Standard (BS) Published Document (PD) 6493, ASME Section XI and The Central Electricity Generating Board (CEGB) R6 approach, The Welding Institute (TWI) CRACKWISE program (based on BS PD6493 Level 2 approach), a variant of the R6 approach, J-tearing instability approaches, various J-estimation schemes, LEFM approach, and simplified stress analysis. Assessments were compared with the results obtained from a hydrogen-charged burst test of the vessel. Predictions, based on the J-tearing approach, compared well with the actual burst test results. Actual burst pressure was about five times the operating pressure.

Bhuyan, G.S. [Powertech Labs Inc., Surrey, British Columbia (Canada); Sperling, E.J. [BP-Amoco, Calgary, Alberta (Canada); Shen, G. [CANMET, Ottawa, Ontario (Canada). Metals Technology Labs.; Yin, H. [Mobil Technology Co., Dallas, TX (United States); Rana, M.D. [Praxair, Inc., Tonawanda, NY (United States)

1999-08-01T23:59:59.000Z

333

Modeling and implementation of solder-activated joints for single actuator, centimeter-scale robotic mechanisms  

E-Print Network (OSTI)

This thesis explains when, and why, solder-based phase change materials (PCMs) are best-suited as a means to modify a robotic mechanism's kinematic and elastomechanic behavior. The preceding refers to mechanisms that possess ...

Telleria, Maria J

2010-01-01T23:59:59.000Z

334

Modeling the mechanical response of PBX 9501  

SciTech Connect

An engineering overview of the mechanical response of Plastic-Bonded eXplosives (PBXs), specifically PBX 9501, will be provided with emphasis on observed mechanisms associated with different types of mechanical testing. Mechanical tests in the form of uniaxial tension, compression, cyclic loading, creep (compression and tension), and Hopkinson bar show strain rate and temperature dependence. A range of mechanical behavior is observed which includes small strain recoverable response in the form of viscoelasticity; change in stiffness and softening beyond peak strength due to damage in the form microcracks, debonding, void formation and the growth of existing voids; inelastic response in the form of irrecoverable strain as shown in cyclic tests, and viscoelastic creep combined with plastic response as demonstrated in creep and recovery tests. The main focus of this paper is to elucidate the challenges and issues involved in modeling the mechanical behavior of PBXs for simulating thermo-mechanical responses in engineering components. Examples of validation of a constitutive material model based on a few of the observed mechanisms will be demonstrated against three point bending, split Hopkinson pressure bar and Brazilian disk geometry.

Ragaswamy, Partha [Los Alamos National Laboratory; Lewis, Matthew W [Los Alamos National Laboratory; Liu, Cheng [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

335

Mechanical properties of irradiated single-layer graphene  

SciTech Connect

The mechanical properties of irradiated single-layer graphene sheets are determined as a function of inserted vacancy concentration. We find that the vacancy-induced crystalline-to-amorphous transition is accompanied by a brittle-to-ductile transition in the failure response of irradiated graphene sheets for inserted vacancy concentrations of 8%-12%. While point defects and larger voids appreciably degrade the strength of pristine graphene, we find that even heavily damaged samples ({approx}20% vacancies) exhibit tensile strengths of {approx}30 GPa, in significant excess of those typical of engineering materials. Our results suggest that defect engineering of graphene is feasible without incurring a complete loss of its desirable mechanical properties.

Carpenter, Corinne; Maroudas, Dimitrios [Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003 (United States); Ramasubramaniam, Ashwin [Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003 (United States)

2013-07-01T23:59:59.000Z

336

Fundamental Scratch Behavior of Styrene-Acrylonitrile Random Copolymers  

E-Print Network (OSTI)

, the mechanical properties of polymer nanocomposites were greatly improved over those of the neat systems and studies in polymer nanocomposite scratch behavior followed suit [47, 69, 75 - 77]. In a study on nanoclay-reinforced PP and PE, Yuan et al. found..., the mechanical properties of polymer nanocomposites were greatly improved over those of the neat systems and studies in polymer nanocomposite scratch behavior followed suit [47, 69, 75 - 77]. In a study on nanoclay-reinforced PP and PE, Yuan et al. found...

Browning, Robert Lee

2011-10-21T23:59:59.000Z

337

Effect of atomic scale plasticity on hydrogen diffusion in iron: Quantum mechanically informed and on-the-fly kinetic  

E-Print Network (OSTI)

viewpoints, is futile. Among several mechanisms proposed for hydrogen embrittlement (HE) of metals, hydrogenEffect of atomic scale plasticity on hydrogen diffusion in iron: Quantum mechanically informed-assisted diffusion and trapping of hydrogen by crystalline defects in iron. Given an embedded atom (EAM) potential

Ortiz, Michael

338

Mechanical and Aerospace Engineering  

E-Print Network (OSTI)

Mechanical and Aerospace Engineering seminar Three Dimensional Traction Force Microscopy with Applications in Cell Mechanics abstract The interactions between biochemical and mechanical signals during-dimensional measurement techniques are needed to investigate the effect of mechanical properties of the substrate

339

Mechanical Engineer Company Description  

E-Print Network (OSTI)

Mechanical Engineer Company Description Control Solutions Inc. is a small, dynamic, and rapidly. Position Description The Mechanical Engineer is responsible for all aspects associated with the mechanical enclosures, brackets, cabling assemblies among others. Systems include mechanisms, sensors, hydraulics, among

Kostic, Milivoje M.

340

MECHANICAL ENGINEERING Ross Schlueter  

E-Print Network (OSTI)

MECHANICAL ENGINEERING Ross Schlueter Engineering Deputy For Mechanical Engineering Russ Wells Mechanical Engineering Department Deputy ELECTRONICS, SOFTWARE & INSTRUMENTATION ENGINEERING Henrik von Der Sen Mechanical Admin. Assist. Joan Wolter Electronics Admin. Assist. Marilyn Wong Division Admin

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Defect characterization of silver-based low-emissivity multilayer coatings for energy-saving applications  

Science Journals Connector (OSTI)

Low-emissivity optical coatings which provide high-efficiency heat isolation are deposited onto architectural windows to be employed in offices and residential buildings for the purpose of saving energy. In the present work multilayer low-emissivity coatings with the structure glass/ SnO 2 (380?)/ NiCr (10?)/ Ag (90?)/ NiCr (30?)/ SnO 2 (380?) were deposited in an industrial sputtering system onto large glass substrates. The extremely low thickness of the layers which compose such structures as well as the large substrate area makes the morphology of the films and interfaces play an important role in providing efficient energy saving performance as well as high optical transmittance. Questions such as the cleaning process of the substrate previous to deposition partial pressure of the gasses in the sputtering system etc. will affect the overall behavior of the coatings. The resulting morphology and composition of the films and interfaces was studied by optical microscopy scanning electron microscopy energy dispersive x ray atomic force microscopy and Auger electron spectroscopy. Some structural defects that might affect the long-term stability of the coatings were found. Furthermore the effect of aggressive environments on the low-emissivity multilayercoatings was tested both from the structural and optical points of view.

R. J. Mart??n-Palma; L. Vzquez; J. M. Mart??nez-Duart

2001-01-01T23:59:59.000Z

342

Scratch behavior of polymers  

E-Print Network (OSTI)

is focused on the analytical and numerical examination of the mechanical response of polypropylene (PP) under scratch deformation by a semi- spherical indenter. The finite element (FE) method is employed as the analysis technique and ABAQUS ? , a... ? ) ?.?????????...????... 152 1 CHAPTER I INTRODUCTION This study is concerned with the analytical and numerical examination of the mechanical response of polypropylene (PP) under scratch deformation by a semi- spherical indenter. The goal of this study is to apply...

Lim, Goy Teck

2005-11-01T23:59:59.000Z

343

Defect Chaos of Oscillating Hexagons in Rotating Convection  

SciTech Connect

Using coupled Ginzburg-Landau equations, the dynamics of hexagonal patterns with broken chiral symmetry are investigated, as they appear in rotating non-Boussinesq or surface-tension-driven convection. We find that close to the secondary Hopf bifurcation to oscillating hexagons the dynamics are well described by a single complex Ginzburg-Landau equation (CGLE) coupled to the phases of the hexagonal pattern. At the band center these equations reduce to the usual CGLE and the system exhibits defect chaos. Away from the band center a transition to a frozen vortex state is found. (c) 2000 The American Physical Society.

Echebarria, Blas; Riecke, Hermann

2000-05-22T23:59:59.000Z

344

Defect characterization and classification for the ICON inspection reliability trials  

SciTech Connect

A major series of inspection reliability trials have been conducted as part of the ICON project, a THERMIE Joint Industry project. Part of the ICON work involved developing a procedure for characterization of the library of cracks. This will be reported in the paper. A second area considered was that of defect classification. This involved a reassessment of previously used classification, in the light of risk based inspection scheduling requirements, and the introduction of a new classification based on PD6493. This work will also be reported together with examples of the measured Probability of Detection curves.

Dover, W.D.; Rudlin, J. [University College London (United Kingdom). NDE Center

1996-12-31T23:59:59.000Z

345

Preshot Predictions for Defect Induced Mix (DIME) Capsules  

SciTech Connect

In this memo, we evaluate the most probable yield and other results for the Defect Induced Mix (DIME-12A) Polar Direct Drive (PDD) capsule-only shots. We evaluate the expected yield, bang time, burn averaged ion temperature, and the average electron temperature of the Ge line-emitting region. We also include synthetic images of the capsule backlit by Cu K-{alpha} emission (8.39 keV) and core self-emission synthetic images. This memo is a companion to the maximum credible yield memo (LA-UR-12-00287) published earlier.

Bradley, Paul A. [Los Alamos National Laboratory; Krasheninnikova, Natalia S. [Los Alamos National Laboratory; Tregillis, Ian L. [Los Alamos National Laboratory; Schmitt, Mark J. [Los Alamos National Laboratory

2012-07-31T23:59:59.000Z

346

Multichannel framework for singular quantum mechanics  

SciTech Connect

A multichannel S-matrix framework for singular quantum mechanics (SQM) subsumes the renormalization and self-adjoint extension methods and resolves its boundary-condition ambiguities. In addition to the standard channel accessible to a distant (asymptotic) observer, one supplementary channel opens up at each coordinate singularity, where local outgoing and ingoing singularity waves coexist. The channels are linked by a fully unitary S-matrix, which governs all possible scenarios, including cases with an apparent nonunitary behavior as viewed from asymptotic distances. -- Highlights: A multichannel framework is proposed for singular quantum mechanics and analogues. The framework unifies several established approaches for singular potentials. Singular points are treated as new scattering channels. Nonunitary asymptotic behavior is subsumed in a unitary multichannel S-matrix. Conformal quantum mechanics and the inverse quartic potential are highlighted.

Camblong, Horacio E., E-mail: camblong@usfca.edu [Department of Physics and Astronomy, University of San Francisco, San Francisco, CA 94117-1080 (United States); Epele, Luis N., E-mail: epele@fisica.unlp.edu.ar [Laboratorio de Fsica Terica, Departamento de Fsica, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 671900 La Plata (Argentina); Fanchiotti, Huner, E-mail: huner@fisica.unlp.edu.ar [Laboratorio de Fsica Terica, Departamento de Fsica, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 671900 La Plata (Argentina)] [Laboratorio de Fsica Terica, Departamento de Fsica, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 671900 La Plata (Argentina); Garca Canal, Carlos A., E-mail: garcia@fisica.unlp.edu.ar [Laboratorio de Fsica Terica, Departamento de Fsica, IFLP, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 671900 La Plata (Argentina); Ordez, Carlos R., E-mail: ordonez@uh.edu [Department of Physics, University of Houston, Houston, TX 77204-5506 (United States)

2014-01-15T23:59:59.000Z

347

The Behavior of Lakes  

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

Behavior of Lakes Behavior of Lakes Nature Bulletin No, 320-A November 9, 1968 Forest Preserve District of Cook County Richard B. Ogilvie, President Roland F. Eisenbeis, Supt. of Conservation THE BEHAVIOR OF LAKES In many ways lakes are like living things -- especially a tree. A lake breathes and has a circulation; it is warmed and fed; it harbors many other living things; and in cold weather it goes into a winter sleep. If it were not for the special character of a body of standing water which we call a lake, the things that live in it would be radically different or, perhaps, not exist at all. Water is a very strange substance in many ways. For example, it is remarkable because it expands, becomes lighter and floats when it freezes into ice. If, like most substances, water shrank when it changed from a liquid to a solid, it would sink. Then, ponds and lakes would freeze from the bottom up and become solid blocks of ice. This would make life impossible for most kinds of aquatic plants and animals and indirectly affect all living things. Further, water is a poor conductor of heat -- otherwise lakes would freeze much deeper and, again most living things in it would perish.

348

Health Behavior Health Promotion -Prevention  

E-Print Network (OSTI)

chronic disease complications Improve quality of life Reduce health care costs #12;ImpactHealth Behavior Health Promotion - Prevention Modification of Health Attitudes and Health Behavior #12;Health Promotion: An Overview Basic philosophy Good health = individual and collective goal

Meagher, Mary

349

Identification of dominant scattering mechanism in epitaxial graphene on SiC  

SciTech Connect

A scheme of identification of scattering mechanisms in epitaxial graphene (EG) on SiC substrate is developed and applied to three EG samples grown on SiC (0001), (112{sup }0), and (101{sup }0) substrates. Hall measurements combined with defect detection technique enable us to evaluate the individual contributions to the carrier scatterings by defects and by substrates. It is found that the dominant scatterings can be due to either substrate or defects, dependent on the substrate orientations. The EG on SiC (112{sup }0) exhibits a better control over the two major scattering mechanisms and achieves the highest mobility even with a high carrier concentration, promising for high performance graphene-based electronic devices. The method developed here will shed light on major aspects in governing carrier transport in EG to harness it effectively.

Lin, Jingjing; Guo, Liwei, E-mail: lwguo@iphy.ac.cn, E-mail: chenx29@aphy.iphy.ac.cn; Jia, Yuping; Huang, Jiao; Guo, Yu; Li, Zhilin; Chen, Xiaolong, E-mail: lwguo@iphy.ac.cn, E-mail: chenx29@aphy.iphy.ac.cn [Research and Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Yang, Rong; Wu, Shuang; Zhang, Guangyu [Nanoscale Physics and Devices Laboratory, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China)

2014-05-05T23:59:59.000Z

350

Annealing behavior of the hydrogen-vacancy complex in bulk indium phosphide crystals  

SciTech Connect

In order to explain the effects of hydrogen on the electrical properties of bulk indium phosphide crystals, they have performed a series of high temperature annealing studies with both undoped and iron-doped indium phosphide crystals. The samples were annealed at 900 C for 6, 36, and 72 hours, respectively, under a phosphorus overpressure of five atmospheres. Samples were characterized at 10 K by Fourier transform infrared absorption spectroscopy which allowed us to measure the concentrations of both the Fe{sup 2+} and V{sub In}-H{sub 4} defects simultaneously. Undoped samples were further characterized by the Hall effect measurements. The authors find in the iron-doped samples that the [Fe{sup 2+}]/[Fe{sup 3+}] ratio decreases gradually with increasing annealing time, indicating a reduction in the number of donors in the samples. In the undoped samples, annealing leads to a reduction of the free electron concentration accompanied by an increase in the 77 K mobility. The increase of the sample`s mobility eliminates the possibility that the reduction of the free electron concentration is due to an increase in the concentration of the compensating acceptors. The explanation for the observed behavior in all samples is that hydrogen acts as a donor and it diffuses out of the crystal during the annealing process. Based on the experimental data, they propose a calibration equation of [V{sub In}-H{sub 4}] = 4.2 {times} 10{sup 16} cm{sup {minus}1} {times} Absorbance (cm{sup {minus}1}) which is used to correlate the hydrogen-vacancy complex concentrations with the changes of the V{sub In}-H{sub 4} absorption peak in both the iron-doped and the undoped samples. Their results confirm the donor nature of the hydrogen-vacancy complex and provide strong evidence regarding the reduction mechanism of free carrier concentrations in bulk indium phosphide crystals during high temperature annealing under a phosphorus atmosphere.

Ye, Q.; Wolk, J.A.; Bourret-Courchesne, E.D. [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.; Bliss, D.F. [Air Force Rome Lab., Hanscom AFB, MA (United States)

1998-12-31T23:59:59.000Z

351

Defect Prevention and Detection in Software for Automated Test Equipment  

SciTech Connect

Software for automated test equipment can be tedious and monotonous making it just as error-prone as other software. Active defect prevention and detection are also important for test applications. Incomplete or unclear requirements, a cryptic syntax used for some test applicationsespecially script-based test sets, variability in syntax or structure, and changing requirements are among the problems encountered in one tester. Such problems are common to all software but can be particularly problematic in test equipment software intended to test another product. Each of these issues increases the probability of error injection during test application development. This report describes a test application development tool designed to address these issues and others for a particular piece of test equipment. By addressing these problems in the development environment, the tool has powerful built-in defect prevention and detection capabilities. Regular expressions are widely used in the development tool as a means of formally defining test equipment requirements for the test application and verifying conformance to those requirements. A novel means of using regular expressions to perform range checking was developed. A reduction in rework and increased productivity are the results. These capabilities are described along with lessons learned and their applicability to other test equipment software. The test application development tool, or application builder, is known as the PT3800 AM Creation, Revision and Archiving Tool (PACRAT).

E. Bean

2006-11-30T23:59:59.000Z

352

Space time as a continuum with a point defect  

E-Print Network (OSTI)

In cosmology it has become usual to try and explain observational data, such as the temperature distribution of the cosmic microwave background or the accelerated expansion of the universe, introducing new entities as dark matter and dark energy. Here we describe a different approach treating space time as a continuum endowed with properties similar to the ones of ordinary material continua, such as internal viscosity and strain distributions originated by defects in the texture. A Lagrangian modelled on the one valid for simple dissipative phenomena in fluids is build and used for empty space time. The internal "viscosity" is shown to correspond to a four-vector field. Using the known symmetry of the universe, assuming the vector field to be divergence-less and solving the Euler-Lagrange equation we obtain directly inflation and a phase of accelerated expansion of space time. The vector field is shown to be connected with the displacement vector field induced by a point defect in a four-dimensional continuum...

Tartaglia, A

2006-01-01T23:59:59.000Z

353

Multichannel Quantum Defect Theory of Strontium Rydberg Series  

E-Print Network (OSTI)

Using the reactance matrix approach, we systematically develop new multichannel quantum defect theory models for the singlet and triplet S, P, D and F states of strontium based on improved energy level measurements. The new models reveal additional insights into the character of doubly excited perturber states, and the improved energy level measurements for certain series allow fine structure to be resolved for those series' perturbers. Comparison between the predictions of the new models and those of previous empirical and \\emph{ab initio} studies reveals good agreement with most series, however some discrepancies are highlighted. Using the multichannel quantum defect theory wave functions derived from our models we calculate other observables such as Land\\'e $g_J$-factors and radiative lifetimes. The analysis reveals the impact of perturbers on the Rydberg state properties of divalent atoms, highlighting the importance of including two-electron effects in the calculations of these properties. The work enables future investigations of properties such as Stark maps and long-range interactions of Rydberg states of strontium.

C L Vaillant; M P A Jones; R M Potvliege

2014-02-24T23:59:59.000Z

354

Defective graphene as promising anode material for Na-ion battery and Ca-ion battery  

E-Print Network (OSTI)

We have investigated adsorption of Na and Ca on graphene with divacancy (DV) and Stone-Wales (SW) defect. Our results show that adsorption is not possible on pristine graphene. However, their adsorption on defective sheet is energetically favorable. The enhanced adsorption can be attributed to the increased charge transfer between adatoms and underlying defective sheet. With the increase in defect density until certain possible limit, maximum percentage of adsorption also increases giving higher battery capacity. For maximum possible DV defect, we can achieve maximum capacity of 1459 mAh/g for Na-ion batteries (NIBs) and 2900 mAh/g for Ca-ion batteries (CIBs). For graphene full of SW defect, we find the maximum capacity of NIBs and CIBs is around 1071 mAh/g and 2142 mAh/g respectively. Our results will help create better anode materials with much higher capacity and better cycling performance for NIBs and CIBs.

Datta, Dibakar; Shenoy, Vivek B

2013-01-01T23:59:59.000Z

355

Heterotic Surface Defects and Dualities from 2d/4d Indices  

E-Print Network (OSTI)

Starting with the superconformal indices for 4d N=2 and N=1 supersymmetric gauge theories, which are related by superpotential deformation, we perform the contour integrations and isolate the residue contributions which can be attributed to the surface defects. These defects can be interpreted as the IR limit of dynamical vortices. Given the 2d N=(2,2) and N=(0,2) world sheet theories for these surface defects, we then verify this statement by explicitly computing their elliptic genera and identifying their fugacity parameters through superconformal algebras. We show them precisely match, and the results extend previous prescriptions for inserting surface defects into 4d supersymmetric partition functions to N=1 setting. We also study how 4d N=1 IR dualities descend into the N=(0,2) world sheet theories of their surface defects, and extend the N=(2,2) triality observed earlier to other N=(0,2) surface defects unrelated to dynamical vortices.

Heng-Yu Chen; Hsiao-Yi Chen

2014-07-17T23:59:59.000Z

356

First principles predictions of intrinsic defects in aluminum arsenide, AlAs : numerical supplement.  

SciTech Connect

This Report presents numerical tables summarizing properties of intrinsic defects in aluminum arsenide, AlAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz, 'First principles predictions of intrinsic defects in Aluminum Arsenide, AlAs', Materials Research Society Symposia Proceedings 1370 (2011; SAND2011-2436C), and intended for use as reference tables for a defect physics package in device models.

Schultz, Peter Andrew

2012-04-01T23:59:59.000Z

357

Origin of type-C defects on the Si(100)-(21) surface  

Science Journals Connector (OSTI)

The generation processes of type-C defects on the Si(100)-(21) surface have been systematically investigated by using scanning tunneling microscopy and infrared absorption spectroscopy. We show that the type-C defect is extrinsic, being caused by bimolecular dissociative adsorption of H2O in the ultrahigh vacuum environment. A structural model of the type-C defect is proposed.

Masayasu Nishizawa; Tetsuji Yasuda; Satoshi Yamasaki; Kazushi Miki; Masanori Shinohara; Nozomu Kamakura; Yasuo Kimura; Michio Niwano

2002-03-28T23:59:59.000Z

358

Nickel Sorption Mechanisms in a Mixed Pyrophyllite-Montmorillonite System  

E-Print Network (OSTI)

Nickel Sorption Mechanisms in a Mixed Pyrophyllite-Montmorillonite System E. J. Elzinga Surface the mechanism responsible for the initial stage of Ni sorption, and surface precipitation being the slower structure (EXAFS) data on sorption studies on Ni/clay systems revealed that the Ni sorption behavior

Sparks, Donald L.

359

ENGINEERING MECHANICS SEMINARSENGINEERING MECHANICS SEMINARS THINK COMPOSITE  

E-Print Network (OSTI)

ENGINEERING MECHANICS SEMINARSENGINEERING MECHANICS SEMINARS THINK COMPOSITE "THINK outside the box" for more competitive structural COMPOSITES Dr. Melih Papila Visiting Professor, Aero/Astro Department, Stanford University. Adv. Composites and Polymer Processing Lab., Sabanci University, Istanbul. mpapila

Ponce, V. Miguel

360

Physical Modeling of Transient Enhanced Diusion and Dopant Deactivation via Extended Defect Evolution  

E-Print Network (OSTI)

Physical Modeling of Transient Enhanced Diusion and Dopant Deactivation via Extended Defect requires the use of well-founded physical models for these aggregation processes. We have developed

Dunham, Scott

Note: This page contains sample records for the topic "defects mechanical behavior" 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

E-Print Network 3.0 - acetabular bone defect Sample Search Results  

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

Journal of Arthroplasty Vol. 14 No. 7 1999 Case Report Summary: modular head and polyethylene liner. Bone defects were filled with morcellized allograft. Three months......

362

Energy Dissipation to Defect Evolution (EDDE) | U.S. DOE Office...  

Office of Science (SC) Website

Dissipation to Defect Evolution (EDDE) Energy Frontier Research Centers (EFRCs) EFRCs Home Centers EFRC External Websites Research Science Highlights News & Events Publications...

363

Mechanical & Biomedical Engineering  

E-Print Network (OSTI)

Mechanical & Biomedical Engineering Department BACHELOR OF SCIENCE IN MECHANICAL ENGINEERING COURSE 105 Mechanical Engineering Graphics 3 CHEM 111L College Chemistry Lab (DLN) 1 ENGL 102 English PHYS 211 Mechanics, Waves & Heat (DLN) 4 UF 100 Intellectual Foundations 3 PHYS 211L Mechanics, Waves

Barrash, Warren

364

K=Knowledge S=Skill AB=Attitude/Behavior  

E-Print Network (OSTI)

Cognitive Domain: K=Knowledge S=Skill AB=Attitude/Behavior Institutional Learning Objectives: KI Knowledge of the normal structure of the human body (cell tissues and organs). K2 Knowledge of the normal function of the human body (cell tissues and organs). K3 Knowledge of the nature of agents and mechanisms

Finley Jr., Russell L.

365

Behavior of Bidirectional Spring Unit in Isolated Floor Systems  

E-Print Network (OSTI)

gravity based sys- tems suspension mechanisms or linear spring based systems coil springs or rubber unitsBehavior of Bidirectional Spring Unit in Isolated Floor Systems Shenlei Cui, M.ASCE1 ; Michel of bidirectional spring units used as isolators in a kind of isolated floor system, three types of characterization

Bruneau, Michel

366

Philosophy of mind and the problem of free will in the light of quantum mechanics  

E-Print Network (OSTI)

Defects occasioned by the advent of quantum mechanics are described in detail of recent arguments by John Searle and by Jaegwon Kim pertaining to the question of the complete reducibility to the physical of the apparent capacity of a person's conscious thoughts to affect the behaviour of that person's physically described brain.

Henry P. Stapp

2008-05-01T23:59:59.000Z

367

Philosophy of Mind and the Problem of FreeWill in the Light of Quantum Mechanics.  

SciTech Connect

Arguments pertaining to the mind-brain connection and to the physical effectiveness of our conscious choices have been presented in two recent books, one by John Searle, the other by Jaegwon Kim. These arguments are examined, and it is argued that the difficulties encountered arise from a defective understanding and application of a pertinent part of contemporary science, namely quantum mechanics.

Stapp, Henry; Stapp, Henry P

2008-04-01T23:59:59.000Z

368

Measuring physical and mechanical properties of individual carbon nanotubes by in situ TEM  

E-Print Network (OSTI)

, was observed only from defect-free carbon nanotubes grown by arc-discharge technique, while such an effect transmission electron microscopy to measure the electric, mechanical and field emission properties, the physical properties of nanomaterials could be quite diverse. The electric properties of carbon nanotubes

Wang, Zhong L.

369

Sea turtle auditory behavior  

Science Journals Connector (OSTI)

Little is known of sea turtles auditory behavior. Startles (neck contractions) were observed in 25 loggerheads (Caretta caretta) to tones from 35 to 1000 Hz when the turtles were near the bottom of holding tanks at a depth of 1 meter. A composite audiogram revealed lowest thresholds in the 400500 Hz range (106 dB SPL re 1 ?m). Thresholds at 735 and 1000 Hz were 117 and 156 dB respectively. Thresholds in the 100200 Hz range were ?124?dB with lower frequencies being 1012 dB higher. Tank diving behavior was elicited with 30 Hz at 164 dB. ABR thresholds to vibration clicks with peak energy at 500 Hz were 113 dB. Seismic air guns (Bolt 600) were employed in a large net enclosure. Turtles increased swimming speed for exposures in the 151161 dB levels. Avoidance ?175?dB was common in initial trials before habituation. ABRs pre? and post?air gun exposures revealed TTS of more than 15 dB in one animal with recovery in 2 weeks. Air guns in depths >10?m may result in more energy in the low frequencies with unknown bioeffects. Turtle repelling with sound is possible and can be made practical (Lenhardt US Patent No. 6388949).

Martin Lenhardt

2002-01-01T23:59:59.000Z

370

Behavioral Ecology Vol. 13 No. 5: 682689 Nonlocal male mountain white-crowned  

E-Print Network (OSTI)

.P. Derryberry is now at the Department of Biology, Duke University, PO Box 90338, Dur- ham, NC 227708, USA. T.P as behavioral iso- lating mechanisms and restrict gene flow a

Derryberry, Elizabeth

371

Mechanical Engineering Graduate Student  

E-Print Network (OSTI)

......................................................................................9 Engineering Career Services ................................................................9 McMechanical Engineering Graduate Student Handbook January 2014 Department of Mechanical Engineering University of Wisconsin-Madison #12;Mechanical Engineering Web Page: http://www.engr.wisc.edu/me Graduate

Wisconsin at Madison, University of

372

Mechanical & Industrial Engineering  

E-Print Network (OSTI)

Mechanical & Industrial Engineering 1 Welcome MIE Industrial Advisory Board October 15, 2010 #12;Mechanical & Industrial Engineering 2 MIE Dorothy Adams Undergraduate/Graduate Secretary David Schmidt Associate Professor & Graduate Program Director #12;Mechanical & Industrial Engineering 3 MIE James Rinderle

Mountziaris, T. J.

373

MECHANICAL ENGINEERING UNDERGRADUATE MAJOR  

E-Print Network (OSTI)

HANDBOOK FOR MECHANICAL ENGINEERING UNDERGRADUATE MAJOR Old Dominion University Department of Mechanical Engineering Batten College of Engineering and Technology Norfolk, Virginia 23529-0247 #12;TABLE OF CONTENTS MECHANICAL ENGINEERING HANDBOOK

374

Mechanical engineering Department Seminar  

E-Print Network (OSTI)

Mechanical engineering Department Seminar Katia Bertoldi Harvard University Soft materials in response to diverse stimuli. While the mechanical attributes - such as energy absorption, stiffness and switchable functionalities. Katia Bertoldi is an Assistant Professor of Applied Mechanics at Harvard

375

Electrodes mitigating effects of defects in organic electronic devices  

DOE Patents (OSTI)

A compound electrode for organic electronic devices comprises a thin first layer of a first electrically conducting material and a second electrically conducting material disposed on the first layer. In one embodiment, the second electrically conducting material is formed into a plurality of elongated members. In another embodiment, the second material is formed into a second layer. The elongated members or the second layer has a thickness greater than that of the first layer. The second layer is separated from the first layer by a conducting material having conductivity less than at least the material of the first layer. The compound electrode is capable of mitigating adverse effects of defects, such as short circuits, in the construction of the organic electronic devices, and can be included in light-emitting or photovoltaic devices.

Heller, Christian Maria Anton (Albany, NY)

2008-05-06T23:59:59.000Z

376

Embedded defects and symmetry breaking in flipped SU(5)  

Science Journals Connector (OSTI)

We explicitly show the analogy between the symmetry-breaking scheme for the GUT flipped SU(5) with that of the Weinberg-Salam theory of electroweak interactions. This allows us to construct the embedded defect spectrum of the flipped SU(5) theory. We find that the spectrum consists of twelve gauge-equivalent unstable leptoquark strings, which are analogous to W strings in electroweak theory, and another string that is gauge inequivalent to the leptoquark strings which we call the V string. The V string is analogous to the Z string of electroweak theory, correspondingly admitting a stable semilocal limit. Using data on the running coupling constants we indicate that in the nonsupersymmetric case V strings can be stable for part of the physically viable parameter space. Cosmological consequences are briefly discussed. 1995 The American Physical Society.

Anne-Christine Davis and Nathan F. Lepora

1995-12-15T23:59:59.000Z

377

Directed polymers in a random environment with a defect line  

E-Print Network (OSTI)

We study the depinning transition of the $1+1$ dimensional directed polymer in a random environment with a defect line. The random environment consists of i.i.d. potential values assigned to each site of $\\mathbb{Z}^2$; sites on the positive axis have the potential enhanced by a deterministic value $u$. We show that for small inverse temperature $\\beta$ the quenched and annealed free energies differ significantly at most in a small neighborhood (of size of order $\\beta$) of the annealed critical point $u_c^a=0$. For the case $u=0$, we show that the difference between quenched and annealed free energies is of order $\\beta^4$ as $\\beta\\to 0$, assuming only finiteness of exponential moments of the potential values, improving existing results which required stronger assumptions.

Kenneth S. Alexander; Gkhan Yildirim

2014-02-26T23:59:59.000Z

378

Point-defect optical transitions and thermal ionization energies from quantum Monte Carlo methods: Application to the F-center defect in MgO  

E-Print Network (OSTI)

We present an approach to calculation of point-defect optical and thermal ionization energies based on the highly accurate quantum Monte Carlo methods. The use of an inherently many-body theory that directly treats electron ...

Ertekin, Elif

379

Monroe Thomas, Mechanical Technician  

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

Monroe Thomas, Mechanical Technician Print The weekend before the ALS was scheduled to start up again after the most recent shutdown, mechanical technician Monroe Thomas kept...

380

Understanding Creep Mechanisms in Graphite with Experiments, Multiscale Simulations, and Modeling  

SciTech Connect

Disordering mechanisms in graphite have a long history with conflicting viewpoints. Using Raman and x-ray photon spectroscoy, electron microscopy, x-ray diffraction experiments and atomistic modeling and simulations, the current project has developed a fundamental understanding of early-to-late state radiation damage mechanisms in nuclear reactor grade graphite (NBG-18 and PCEA). We show that the topological defects in graphite play an important role under neutron and ion irradiation.

Eapen, Jacob; Murty, Korukonda; Burchell, Timothy

2014-06-02T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Effect of defect imbalance on void swelling distributions produced in pure iron irradiated with 3.5 MeV self-ions  

SciTech Connect

Ion irradiation has been widely used to simulate neutron-induced radiation damage. There are a number of features of ion-induced damage that differ from neutron-induced damage, however, and these differences require investigation before ion data can be confidently used to predict behavior arising from neutron bombardment. In this study 3.5 MeV self-ion irradiation of pure iron was used to study the influence on void swelling of the depth-dependent defect imbalance between vacancies and interstitials that arises from various surface effects, forward scattering of displaced atoms, and especially the injected interstitial effect. It was observed that the depth dependence of void swelling does not follow the behavior anticipated from the depth dependence of the damage rate. Void nucleation and growth develop first in the lower-dose, near-surface region, and then moves to progressively deeper and higher-damage depths during continued irradiation. This indicates a strong initial suppression of void nucleation in the peak damage region that is eventually overcome with continued irradiation. Using the Boltzmann transport equation method, this phenomenon is shown to be due to depth-dependent defect imbalances created under ion irradiation. These findings demonstrate that void swelling does not depend solely on the local dose level and that this sensitivity of swelling to depth must be considered in extraction and interpretation of ion-induced swelling data. 2014 El

Lin Shao; C.-C. Wei; J. Gigax; A. Aitkaliyeva; D. Chen; B.H. Sencer; F.A. Garner

2014-10-01T23:59:59.000Z

382

Observations of an Impurity-driven Hysteresis Behavior in Ice Crystal Growth at Low Pressure  

E-Print Network (OSTI)

mechanisms for this instability, which can be used to produce clean, faceted ice surfaces. 1 IntroductionObservations of an Impurity-driven Hysteresis Behavior in Ice Crystal Growth at Low Pressure Abstract. We describe observations of a novel hysteresis behavior in the growth of ice crystals under near

Libbrecht, Kenneth G.

383

S9 -Kinetics & Mechanism of Metal Sorption/Release on Natural Materials ADSORPTION MECHANISMS OF PB ON AMORPHOUS SILICA: AN XAS  

E-Print Network (OSTI)

S9 - Kinetics & Mechanism of Metal Sorption/Release on Natural Materials ADSORPTION MECHANISMS the sorption behavior and mechanisms of Pb on amorphous silica using X-ray absorption spectroscopy (XAS t h o d s Pb sorption on silica was studied as a function of pH. The pH range used was pH 3

Sparks, Donald L.

384

Defect-Free, Size-Tunable Graphene for High-Performance Lithium Ion Battery  

Science Journals Connector (OSTI)

Defect-Free, Size-Tunable Graphene for High-Performance Lithium Ion Battery ... These results propose that the as-prepared defect free graphene will bring significant advance of composite electrodes for high performance in electrochemical energy systems such as batteries, fuel cells, and capacitors. ...

Kwang Hyun Park; Dongju Lee; Jungmo Kim; Jongchan Song; Yong Min Lee; Hee-Tak Kim; Jung-Ki Park

2014-07-11T23:59:59.000Z

385

Topological description of the Stone-Wales defect formation energy in carbon nanotubes and graphene  

E-Print Network (OSTI)

Topological description of the Stone-Wales defect formation energy in carbon nanotubes and graphene,10,12,16,18,26 The reported values for SW defect formation energies both in carbon nanotubes and graphene8 energies depend largely on the nanotube radius, the orientation of the dislocation dipole, and, to a lesser

Daw, Murray S.

386

Heart Defects in Gulf Tuna Seen Tied to 2010 BP Oil Spill  

E-Print Network (OSTI)

Heart Defects in Gulf Tuna Seen Tied to 2010 BP Oil Spill By Jim Efstathiou Jr. Mar 25, 2014 12 of Mexico spill may have led to heart defects and premature death for tuna, researchers backed hearts may reduce swimming performance, jeopardizing a fish's survival. "The timing and location

Grosell, Martin

387

Electrochemical method for defect delineation in silicon-on-insulator wafers  

DOE Patents (OSTI)

An electrochemical method for defect delineation in thin-film SOI or SOS wafers in which a surface of a silicon wafer is electrically connected so as to control the voltage of the surface within a specified range, the silicon wafer is then contacted with an electrolyte, and, after removing the electrolyte, defects and metal contamination in the silicon wafer are identified.

Guilinger, Terry R. (Albuquerque, NM); Jones, Howland D. T. (Albuquerque, NM); Kelly, Michael J. (Albuquerque, NM); Medernach, John W. (Albuquerque, NM); Stevenson, Joel O. (Albuquerque, NM); Tsao, Sylvia S. (Albuquerque, NM)

1991-01-01T23:59:59.000Z

388

Principal component analysis based on wavelet characteristics applied to automated surface defect inspection  

Science Journals Connector (OSTI)

Automated visual inspection, a crucial manufacturing step, has been replacing the more time-consuming and less accurate human inspection. This research explores automated visual inspection of surface defects in a light-emitting diode (LED) chip. Commonly ... Keywords: hotelling statistic, machine vision system, principal component analysis, surface defect inspection, wavelet characteristics

Hong-Dar Lin; Chung-Yu Chung; Wan-Ting Lin

2008-04-01T23:59:59.000Z

389

DuoTracker: Tool Support for Software Defect Data Collection and Analysis  

E-Print Network (OSTI)

evaluate their process using either the Capability Maturity Model (CMM) [3] or the ISO 9001 standards [4 software processes. Keywords--software defects; software anomalies; defect classification; PSP; CMM; IS0-9001 is then compared against the quality models of CMM or IS0 9001. There are also improvement methods such as IDEAL [5

Dascalu, Sergiu

390

Inspection of surface defects in copper strip using multivariate statistical approach and SVM  

Science Journals Connector (OSTI)

The surface quality would directly influence the capability and quality of the final product, but there is little domestic research focused on surface defects inspection for copper strip based on automated visual inspection. According to the gradual change of intensity levels of copper strips surface defect, a defect detection algorithm is proposed using wavelet-based multivariate statistical analysis. First, the image is divided into several sub-images, namely statistical units, and then each unit is further decomposed into multiple wavelet processing units. Then each wavelet processing unit is decomposed by 1D db4 wavelet function. Then, multivariate statistics of Hotelling T are applied to distinguish the existence of defects and classify the defects using support vector machine (SVM). During SVM design, the authors used cross-validation method to get the best parameters and then used the parameters to train and test the samples. Finally, the defect detection performance of the proposed approach is compared with the traditional method based on greyscale. Experimental results demonstrate that the proposed method has better performance on identification, especially its application in the ripple defects can achieve a 96.7% probability of detecting the existence of micro defects, which was poor in common algorithms.

Xue-Wu Zhang; Fang Gong; Li-Zhong Xu

2012-01-01T23:59:59.000Z

391

Recombination between a defective retrovirus and homologous sequences in host DNA: reversion by patch repair.  

Science Journals Connector (OSTI)

...transcriptase assay (16). Virus infections were car- ried out with the addition of polybrene...NIH/3T3 cells were infected with the defective virions as described above, but these...infected cell. Thus, we have shown that defective viruses can repair their mutations by...

P Schwartzberg; J Colicelli; S P Goff

1985-03-01T23:59:59.000Z

392

Multiscale finite element analysis of elastic wave scattering from localized defects  

Science Journals Connector (OSTI)

This paper investigates the use of a multiscale finite element approach to study the interaction between elastic waves and localized defects. The analysis of wave-defect interaction is of fundamental importance for the development of ultrasonic non-destructive ... Keywords: Elastic wave scattering, Finite element method, Multiscale analysis

F. Casadei, J. J. Rimoli, M. Ruzzene

2014-10-01T23:59:59.000Z

393

IDENTIFICATION OF IMPACTING FACTORS OF SURFACE DEFECTS IN HOT ROLLING PROCESSES USING MULTI-LEVEL REGRESSION  

E-Print Network (OSTI)

IDENTIFICATION OF IMPACTING FACTORS OF SURFACE DEFECTS IN HOT ROLLING PROCESSES USING MULTI. The result obtained can provide guidelines for root cause identification and quality improvement of hot products. Surface defects remain as a weakness or stress concentration site of the bulk material and hence

Zhou, Shiyu

394

Impurity-defect interaction in polycrystalline silicon for photovoltaic applications. The role of hydrogen  

E-Print Network (OSTI)

of the cell ? ii) Will the defects of the polycrystalline material hinder the photovoltaic properties..., leading also to a degradation of the efficiency of the photovoltaic cells ? iii) What would655 Impurity-defect interaction in polycrystalline silicon for photovoltaic applications. The role

Paris-Sud XI, Université de

395

Ian Sommerville 2000 Software Engineering, 6th edition. Chapter 20 Slide 1 Defect testing  

E-Print Network (OSTI)

©Ian Sommerville 2000 Software Engineering, 6th edition. Chapter 20 Slide 1 Defect testing l Testing programs to establish the presence of system defects #12;©Ian Sommerville 2000 Software Engineering, 6th edition. Chapter 20 Slide 2 Objectives l To understand testing techniques that are geared

Scharff, Christelle

396

Stone-Wales defects in graphene and other planar sp2 -bonded materials  

E-Print Network (OSTI)

Stone-Wales defects in graphene and other planar sp2 -bonded materials Jie Ma,1,2,3 Dario Alfè,2 that the structure of the Stone-Wales SW defect in graphene is more complex than hitherto appreciated. Rather than of graphene and in so doing modify its chemical re- activity toward adsorbates, and likely impact upon its

Alfè, Dario

397

Understanding structural defects in lithium-rich layered oxide cathodes Karalee A. Jarvis,a  

E-Print Network (OSTI)

the required amounts of lithium, manganese, and nickel acetates were added to this solution. The molar ratioUnderstanding structural defects in lithium-rich layered oxide cathodes Karalee A. Jarvis, Accepted 31st March 2012 DOI: 10.1039/c2jm30575e Planar defects in lithium-rich layered oxides were

Ferreira, Paulo J.

398

Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J. Keinonen  

E-Print Network (OSTI)

Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J-principles calculations were used in determining the binding and trapping properties of hydrogen to point defects in tungsten. Hydrogen zero-point vibrations were taken into account. It was concluded that the monovacancy can

Nordlund, Kai

399

Silicon Solar Cell Light-Trapping Using Defect Mode Photonic Kelsey A. Whitesell*a  

E-Print Network (OSTI)

Silicon Solar Cell Light-Trapping Using Defect Mode Photonic Crystals Kelsey A. Whitesell to enhance performance of thin film solar cells because of their unique ability to control light. We show for light trapping in thin film photovoltaics. Keywords: photonic crystals, defect, silicon, solar cell

Atwater, Harry

400

Characterization of the nitrogen split interstitial defect in wurtzite aluminum nitride using density functional theory  

SciTech Connect

We carried out Heyd-Scuseria-Ernzerhof hybrid density functional theory plane wave supercell calculations in wurtzite aluminum nitride in order to characterize the geometry, formation energies, transition levels, and hyperfine tensors of the nitrogen split interstitial defect. The calculated hyperfine tensors may provide useful fingerprint of this defect for electron paramagnetic resonance measurement.

Szlls, A., E-mail: szallas.attila@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Szsz, K. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Institute of Physics, Etvs University, Pzmny Pter stny 1/A, H-1117 Budapest (Hungary); Trinh, X. T.; Son, N. T.; Janzn, E. [Department of Physics, Chemistry and Biology, Linkping University, SE-581 83 Linkping (Sweden); Gali, A., E-mail: gali.adam@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki t 8, H-1111 Budapest (Hungary)

2014-09-21T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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.


401

Dark defects in InGaAsP/InP double heterostructure lasers under accelerated aging  

SciTech Connect

Degradation modes due to dark defects under accelerated aging for InGaAsP/InP double heterostructure lasers are investigated by monitoring pulse threshold current, leak current, absorption coefficient, gain factor, and electroluminescence topograph. Most of the dark defects are dark spot defects (DSD's) and there are only few <100> dark line defects. At the initial stage of the degradation, these dark defects scarcely absorb the emitted light, and the reduction of gain factor causes the increase of pulse threshold current. After this stage, dark defects begin to act as absorber of the emitted light. The generation time of such DSD's strongly depends on the injected current density but only weakly on the junction temperature in the range of 25/sup 0/ to 250/sup 0/C. The activation energies for the generation time of the first dark spot defect and the growing speed of <100> dark line defects are estimated to be 0.16 and 0.2 eV, respectively.

Fukuda, M.; Wakita, K.; Iwane, G.

1983-03-01T23:59:59.000Z

402

First-principles calculations of defects in oxygen-deficient silica exposed to hydrogen  

Science Journals Connector (OSTI)

Hydrogen-related defects and oxygen vacancies in silica are analyzed using first-principles density-functional calculations. Energetics, structures, charge-state levels, and hyperfine parameters are determined. These calculations identify the hydrogen bridge related to the E4? center as the defect responsible for the stress-induced leakage current, a forerunner of dielectric breakdown of gate oxides in transistors.

Peter E. Blchl

2000-09-01T23:59:59.000Z

403

Exploring the interaction between lithium ion and defective graphene surface using dispersion corrected DFT studies  

SciTech Connect

To analyze the lithium ion interaction with realistic graphene surfaces, we carried out dispersion corrected DFT-D3 studies on graphene with common point defects and chemisorbed oxygen containing functional groups along with defect free graphene surface. Our study reveals that, the interaction between lithium ion (Li+) and graphene is mainly through the delocalized ? electron of pure graphene layer. However, the oxygen containing functional groups pose high adsorption energy for lithium ion due to the Li-O ionic bond formation. Similarly, the point defect groups interact with lithium ion through possible carbon dangling bonds and/or cation-? type interactions. Overall these defect sites render a preferential site for lithium ions compared with pure graphene layer. Based on these findings, the role of graphene surface defects in lithium battery performance were discussed.

Vijayakumar, M.; Hu, Jian Z.

2013-10-15T23:59:59.000Z

404

Delocalised oxygen as the origin of two-level defects in Josephson junctions  

E-Print Network (OSTI)

One of the key problems facing superconducting qubits and other Josephson junction devices is the decohering effects of bi-stable material defects. Although a variety of phenomenological models exist, the true microscopic origin of these defects remains elusive. For the first time we show that these defects may arise from delocalisation of the atomic position of the oxygen in the oxide forming the Josephson junction barrier. Using a microscopic model, we compute experimentally observable parameters for phase qubits. Such defects are charge neutral but have non-zero response to both applied electric field and strain. This may explain the observed long coherence time of two-level defects in the presence of charge noise, while still coupling to the junction electric field and substrate phonons.

Timothy C. DuBois; Manolo C. Per; Salvy P. Russo; Jared H. Cole

2012-06-12T23:59:59.000Z

405

An Atom-Wide Antennae Created from Difference-Making Defects | Department  

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

An Atom-Wide Antennae Created from Difference-Making Defects An Atom-Wide Antennae Created from Difference-Making Defects An Atom-Wide Antennae Created from Difference-Making Defects March 7, 2012 - 3:35pm Addthis Take advantage of microwave microscopy, researchers were able to locate graphene islands on graphene. “Point defects” locally enhanced the graphene’s ability to transform waves of light into electronic signals. | Photo courtesy of Oak Ridge National Laboratory. Take advantage of microwave microscopy, researchers were able to locate graphene islands on graphene. "Point defects" locally enhanced the graphene's ability to transform waves of light into electronic signals. | Photo courtesy of Oak Ridge National Laboratory. Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science

406

The nano-mechanical morphology of shale  

Science Journals Connector (OSTI)

Shale, the sealing formations in most hydrocarbon reservoirs, is made of highly compacted clay particles of sub-micrometer size, nanometric porosity and different mineralogy. In this paper, we propose and validate a technique to identify the nano-mechanical morphology of such a nanocomposite material. In particular, by means of a massive nanoindentation campaign at two different scales on a large range of shale materials, we show that the highly compacted plate- or sheet-like clay particles have a distinct nano-mechanical morphology with no privileged orientation of the particle-to-particle contact surface, as evidenced by a mechanical percolation threshold of ?0?0.5. Furthermore, the nanoindentation results provide strong evidence that the nano-mechanical elementary building block of shales is transversely isotropic in stiffness, and isotropic and frictionless in strength. These observations lead to a sphere-like mechanical morphology for visibly plate- or sheet-like clay particles. The contact forces between the sphere-like particles activate the intrinsicly anisotropic elastic properties within the clay particles and the cohesive bonds between the clay particles. The mechanical stiffness and strength properties of porous clay scale with the clay packing density toward a unique set of shale-invariant material properties. The determination of mechanical microstructure and invariant material properties are of great importance for the development of predictive microporomechanical models of the stiffness and strength properties of shale. The approach presented here also applies to other chemically and mechanically complex materials exhibiting nanogranular behavior.

Christopher Bobko; Franz-Josef Ulm

2008-01-01T23:59:59.000Z

407

Automobile Driving and Aggressive Behavior  

E-Print Network (OSTI)

The accident prone automobile driver. American Journal ofAutomobile Driving And Aggressive Behavior Raymond W. Novacofor its content or use. Automobile Driving and Aggressive

Novaco, Raymond W.

1991-01-01T23:59:59.000Z

408

Acceleration of dormant storage effects to address the reliability of silicon surface micromachined Micro-Electro-Mechanical Systems (MEMS).  

SciTech Connect

Qualification of microsystems for weapon applications is critically dependent on our ability to build confidence in their performance, by predicting the evolution of their behavior over time in the stockpile. The objective of this work was to accelerate aging mechanisms operative in surface micromachined silicon microelectromechanical systems (MEMS) with contacting surfaces that are stored for many years prior to use, to determine the effects of aging on reliability, and relate those effects to changes in the behavior of interfaces. Hence the main focus was on 'dormant' storage effects on the reliability of devices having mechanical contacts, the first time they must move. A large number ({approx}1000) of modules containing prototype devices and diagnostic structures were packaged using the best available processes for simple electromechanical devices. The packaging processes evolved during the project to better protect surfaces from exposure to contaminants and water vapor. Packages were subjected to accelerated aging and stress tests to explore dormancy and operational environment effects on reliability and performance. Functional tests and quantitative measurements of adhesion and friction demonstrated that the main failure mechanism during dormant storage is change in adhesion and friction, precipitated by loss of the fluorinated monolayer applied after fabrication. The data indicate that damage to the monolayer can occur at water vapor concentrations as low as 500 ppm inside the package. The most common type of failure was attributed to surfaces that were in direct contact during aging. The application of quantitative methods for monolayer lubricant analysis showed that even though the coverage of vapor-deposited monolayers is generally very uniform, even on hidden surfaces, locations of intimate contact can be significantly depleted in initial concentration of lubricating molecules. These areas represent defects in the film prone to adsorption of water or contaminants that can cause movable structures to adhere. These analysis methods also indicated significant variability in the coverage of lubricating molecules from one coating process to another, even for identical processing conditions. The variability was due to residual molecules left in the deposition chamber after incomplete cleaning. The coating process was modified to result in improved uniformity and total coverage. Still, a direct correlation was found between the resulting static friction behavior of MEMS interfaces, and the absolute monolayer coverage. While experimental results indicated that many devices would fail to start after aging, the modeling approach used here predicted that all the devices should start. Adhesion modeling based upon values of adhesion energy from cantilever beams is therefore inadequate. Material deposition that bridged gaps was observed in some devices, and potentially inhibits start-up more than the adhesion model indicates. Advances were made in our ability to model MEMS devices, but additional combined experimental-modeling studies will be needed to advance the work to a point of providing predictive capability. The methodology developed here should prove useful in future assessments of device aging, however. Namely, it consisted of measuring interface properties, determining how they change with time, developing a model of device behavior incorporating interface behavior, and then using the age-aware interface behavior model to predict device function.

Cox, James V.; Candelaria, Sam A.; Dugger, Michael Thomas; Duesterhaus, Michelle Ann; Tanner, Danelle Mary; Timpe, Shannon J.; Ohlhausen, James Anthony; Skousen, Troy J.; Jenkins, Mark W.; Jokiel, Bernhard, Jr.; Walraven, Jeremy Allen; Parson, Ted Blair

2006-06-01T23:59:59.000Z

409

Mechanical & Industrial Engineering  

E-Print Network (OSTI)

Mechanical & Industrial Engineering 1 Welcome MIE Industrial Advisory Board May 5th, 2011 #12;Mechanical & Industrial Engineering 2 IAB 2010-2011 · David K. Anderson ­ Alden Research Laboratory, Inc went on for three weeks Mechanical & Industrial Engineering 6 #12;Reza Shahbazian Yassar Mechanical

Mountziaris, T. J.

410

Career Map: Mechanical Engineer  

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

The Wind Program's Career Map provides job description information for Mechanical Engineer positions.

411

Mechanical Engineering Undergraduate  

E-Print Network (OSTI)

Mechanical Engineering Department Undergraduate Advising Manual for Bachelor of Science Degrees in Mechanical Engineering and Engineering Mechanics 2011-2012 - Updated April 15, 2012 #12;Johns Hopkins University ­ Department of Mechanical Engineering 2011-2012 Undergraduate Student Advising Manual Page 2

Ghosh, Somnath

412

Mechanical engineering Department Seminar  

E-Print Network (OSTI)

Mechanical engineering Department Seminar James Bird Department of Mechanical Engineering Boston ­ are discussed. James Bird is an Assistant Professor in the Mechanical Engineering Department at Boston completed post-doctoral research at MIT. His research interests include experimental fluid mechanics

413

Mechanical Engineering Undergraduate  

E-Print Network (OSTI)

Mechanical Engineering Department Undergraduate Advising Manual for Bachelor of Science Degrees in Mechanical Engineering and Engineering Mechanics 2012-2013 - Updated July 14, 2013 #12;Johns Hopkins University ­ Department of Mechanical Engineering 2012-2013 Undergraduate Student Advising Manual Page 2

Ghosh, Somnath

414

Mechanical Engineering & Thermal Group  

E-Print Network (OSTI)

Mechanical Engineering & Thermal Group The Mechanical Engineering (ME) & Thermal Group at LASP has, and ground- based mechanical systems. Instrument Design Building on decades of design experience that has evolved with the complexity of instrument design demands, LASP mechanical engineers develop advanced

Mojzsis, Stephen J.

415

Combined Quantum Mechanical and Molecular Mechanics Studies of...  

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

Mechanical and Molecular Mechanics Studies of the Electron-Transfer Reactions Involving Carbon Tetrachloride in Combined Quantum Mechanical and Molecular Mechanics Studies of the...

416

Does complex absorption behavior leading to conditioning and damage in KDP/DKDP reflect the electronic structure of initiators?  

SciTech Connect

Currently, most of our thinking about the defects responsible for initiating laser damage considers them as featureless absorbers. However, an increasing body of evidence, particularly involving multi-wavelength irradiation, suggests electronic structure of damage initiators is important in determining both initiation and conditioning behaviors in KDP. The effective absorption coefficient of energy under multi-wavelength irradiation cannot be accounted for by a structureless absorber, but is consistent with an initiator with a multi-level structure. We outline the evidence and assess the ability of such a simple multi-level model to explain these and other experimentally observed behaviors.

Feit, M D; DeMange, P P; Negres, R A; Rubenchik, A M; Demos, S G

2007-10-24T23:59:59.000Z

417

Ion Hydration and Associated Defects in Hydrogen Bond Network of Water: Observation of Reorientationally Slow Water Molecules Beyond First Hydration Shell in Aqueous Solutions of MgCl$_2$  

E-Print Network (OSTI)

Effects of presence of ions, at moderate to high concentrations, on dynamical properties of water molecules are investigated through classical molecular dynamics simulations using two well known non-polarizable water models. Simulations reveal that the presence of magnesium chloride (MgCl$_2$) induces perturbations in the hydrogen bond network of water leading to the formation of bulk-like domains with \\textquoteleft defect sites\\textquoteright~on boundaries of such domains: water molecules at such defect sites have less number of hydrogen bonds than those in bulk water. Reorientational autocorrelation functions for dipole vectors of such defect water molecules are computed at different concentrations of ions and compared with system of pure water. Earlier experimental and simulation studies indicate significant differences in reorientational dynamics for water molecules in the first hydration shell of many dissolved ions. Results of this study suggest that defect water molecules, which are beyond the first hydration shells of ions, also experience significant slowing down of reorientation times as a function of concentration in the case of MgCl$_2$. However, addition of cesium chloride(CsCl) to water does not perturb the hydrogen bond network of water significantly even at higher concentrations. This difference in behavior between MgCl$_2$ and CsCl is consistent with the well-known Hofmeister series.

Upayan Baul; Satyavani Vemparala

2014-12-18T23:59:59.000Z

418

Inhibition of Repair of Radiation-Induced DNA Damage Enhances Gene Expression from Replication-Defective Adenoviral Vectors  

Science Journals Connector (OSTI)

...those related to increased expression of CAR and integrin are responsible for the enhanced...of gene expression from replication-defective adenoviral vectors: implications for...enhances gene expression from replication-defective adenoviral vectors. | Radiation has been...

Mohan Hingorani; Christine L. White; Andrew Merron; Inge Peerlinck; Martin E. Gore; Andrew Slade; Simon D. Scott; Christopher M. Nutting; Hardev S. Pandha; Alan A. Melcher; Richard G. Vile; Georges Vassaux; and Kevin J. Harrington

2008-12-01T23:59:59.000Z

419

Investigation of defect properties in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy  

E-Print Network (OSTI)

Investigation of defect properties in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy defect levels in absorber materials, and may be used to support the identification of remedial processing

Anderson, Timothy J.

420

Sandia National Laboratories: Mechanical Testing  

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

EnergyNuclear Energy Systems Laboratory (NESL) Brayton LabMechanical Testing Mechanical Testing Mechanical Testing Overview Mechanical 1-2 (2008). Standard Test Methods for...

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Marine turtle auditory behavior  

Science Journals Connector (OSTI)

Auditory capacities of the Atlantic Loggerhead (Caretta c. caretta) were assessed to develop a sound repelling system to be used in dangerous areas. To estimate sensitivity auditory brain?stem responses (ABRs) were recorded in ten animals to clicks and tones (250 500 750 and 1000 Hz). Animals removed from water had electrodes implanted subcutaneously. Stimuli were presented to eardrum with a vibrator. Consistent responses occurred within the first 10 ms after stimulation not unlike that recorded in nonmarine forms. ABR waveforms increase in latency with stimulus attenuation. Prior to ABR recording sound?induced head movements were noted in most but not all animals. Sound?induced swimming was also observed. A flight response within the artificial environment of a small tank may not predict natural behavior hence animals will be placed in a saltwater pen and the experiments repeated with a sound source away from the animal. Finally animals fitted with transmitters will be released in the lower Chesapeake Bay. After settling into a selected area they will be approached by a moving sound projector to determine if this sound induces flight.

S. Moein; M. Lenhardt; D. Barnard; J. Keinath; J. Musick

1993-01-01T23:59:59.000Z

422

Superplastic behavior of Al-Li 2090 OE-16 (ALCOA)  

E-Print Network (OSTI)

SUPERPLASTIC BEHAVIOR OF AL-LI 2090 OE-16 (ALCOA) A Thesis by LAMBROS STAMATIOU DOUSKOS Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1991... Major Subject: Mechanical Engineering SUPERPLASTIC BEHAVIOR OF AL-LI 2090 OE-16 (ALCOA) A Thesis By LAMBROS STAMATIOU DOUSKOS Approved as to style and content by: R. E. oforth (Chair o Committee) alur N. S inivasan (Member) . J. Fox, R (Member...

Douskos, Lambros Stamatiou

1991-01-01T23:59:59.000Z

423

Information Recovery In Behavioral Networks  

E-Print Network (OSTI)

In the context of agent based modeling and network theory, we focus on the problem of recovering micro behavior-related choice information from aggregate origin-destination data. As a basis for predicting agents' choices we emphasize the connection between adaptive intelligent behavior, causal entropy maximization and self-organized, equilibrium-seeking behavior in a dynamic system. We cast this problem in the form of a binary network and suggest information theoretic, entropy-driven methods to recover estimates of the unknown parameters connecting the behavioral data. Our objective is to recover the unknown behavioral binary parameters analytically, without explicitly sampling the configuration space. In order to do so, we enlarge the set of estimators commonly employed to make optimal use of the available information. More specifically, we consider the Cressie-Read family of entropic functionals and focus on three cases of particular interest. We then apply this information theoretic method to the analysis ...

Squartini, Tiziano; Garlaschelli, Diego; Judge, George

2015-01-01T23:59:59.000Z

424

NSLS Mechanical Tech  

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

Mechanical Tech Mechanical Tech The Mechanical Technician group is supervised by Robert Scheuerer and consists of Mechanical Technicians with fabrication/machining, assembly, installation, and alignment/surveying skills. This group also serves as an interface to Central Fabrication Services when more complex or larger fabrication efforts are needed. The Mechanical Tech group is responsible for fabricating, installing, aligning, and troubleshooting the mechanical hardware used on NSLS and SDL accelerators, front ends, and User beamlines, often starting solely from Mechanical Design group drawings or CAD files. The Mechanical Tech Group is responsible for the fabrication, assembly and installation of components at the NSLS. These components include all mechanical assemblies and RF cavities. Another part of their job is to

425

Nonlinear geometric effects in mechanical bistable morphing structures  

E-Print Network (OSTI)

Bistable structures associated with non-linear deformation behavior, exemplified by the Venus flytrap and slap bracelet, can switch between different functional shapes upon actuation. Despite numerous efforts in modeling such large deformation behavior of shells, the roles of mechanical and nonlinear geometric effects on bistability remain elusive. We demonstrate, through both theoretical analysis and table-top experiments, that two dimensionless parameters control bistability. Our work classifies the conditions for bistability, and extends the large deformation theory of plates and shells.

Zi Chen; Qiaohang Guo; Carmel Majidi; Wenzhe Chen; David J. Srolovitz; Mikko P. Haataja

2012-06-20T23:59:59.000Z

426

Quantitative description of microstructure defects in hexagonal boron nitrides using X-ray diffraction analysis  

SciTech Connect

A routine for simultaneous quantification of turbostratic disorder, amount of puckering and the dislocation and stacking fault density in hexagonal materials was proposed and tested on boron nitride powder samples that were synthesised using different methods. The routine allows the individual microstructure defects to be recognised according to their effect on the anisotropy of the X-ray diffraction line broadening. For quantification of the microstructure defects, the total line broadening is regarded as a linear combination of the contributions from the particular defects. The total line broadening is obtained from the line profile fitting. As testing material, graphitic boron nitride (h-BN) was employed in the form of hot-isostatically pressed h-BN, pyrolytic h-BN or a h-BN, which was chemically vapour deposited at a low temperature. The kind of the dominant microstructure defects determined from the broadening of the X-ray diffraction lines was verified by high resolution transmission electron microscopy. Their amount was attempted to be verified by alternative methods. - Highlights: Reliable method for quantification of microstructure defects in BN was suggested. The method is based on the analysis of anisotropic XRD line broadening. This XRD line broadening is unique and characteristic of the respective defect. Thus, the quantification of coexistent microstructure defects is possible. The method was tested on hexagonal BN, which was produced by different techniques.

Schimpf, C., E-mail: schimpf@iww.tu-freiberg.de; Motylenko, M.; Rafaja, D.

2013-12-15T23:59:59.000Z

427

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics  

DOE Patents (OSTI)

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser`s wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known ``feature masks`` of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects. 29 figs.

Ellingson, W.A.; Brada, M.P.

1995-06-20T23:59:59.000Z

428

Optical method and apparatus for detection of surface and near-subsurface defects in dense ceramics  

DOE Patents (OSTI)

A laser is used in a non-destructive manner to detect surface and near-subsurface defects in dense ceramics and particularly in ceramic bodies with complex shapes such as ceramic bearings, turbine blades, races, and the like. The laser's wavelength is selected based upon the composition of the ceramic sample and the laser can be directed on the sample while the sample is static or in dynamic rotate or translate motion. Light is scattered off surface and subsurface defects using a preselected polarization. The change in polarization angle is used to select the depth and characteristics of surface/subsurface defects. The scattered light is detected by an optical train consisting of a charge coupled device (CCD), or vidicon, television camera which, in turn, is coupled to a video monitor and a computer for digitizing the image. An analyzing polarizer in the optical train allows scattered light at a given polarization angle to be observed for enhancing sensitivity to either surface or near-subsurface defects. Application of digital image processing allows subtraction of digitized images in near real-time providing enhanced sensitivity to subsurface defects. Storing known "feature masks" of identified defects in the computer and comparing the detected scatter pattern (Fourier images) with the stored feature masks allows for automatic classification of detected defects.

Ellingson, William A. (Naperville, IL); Brada, Mark P. (Goleta, CA)

1995-01-01T23:59:59.000Z

429

Comparison of fast 3D simulation and actinic inspection for EUV masks with buries defects  

SciTech Connect

Aerial images for isolated defects and the interactions of defects with features are compared between the Actinic Inspection Tool (AIT) at Lawrence Berkeley National Laboratory (LBNL) and the fast EUV simulation program RADICAL. Comparisons between AIT images from August 2007 and RADICAL simulations are used to extract aberrations. At this time astigmatism was the dominant aberration with a value of 0.55 waves RMS. Significant improvements in the imaging performance of the AIT were made between August 2007 and December 2008. A good match will be shown between the most recent AIT images and RADICAL simulations without aberrations. These comparisons will demonstrate that a large defect, in this case 7nm tall on the surface, is still printable even if it is centered under the absorber line. These comparisons also suggest that the minimum defect size is between 1.5nm and 0.8nm surface height because a 1.5nm defect was printable but a 0.8nm was not. Finally, the image of a buried defect near an absorber line through focus will demonstrate an inversion in the effect of the defect from a protrusion of the dark line into the space to a protrusion of the space into the line.

Clifford, C. H.; Wiraatmadja, S.; Chan, T. T.; Neureuther, A. R.; Goldberg, K. A.; Mochi, I.; Liang, T.

2009-02-23T23:59:59.000Z

430

Assembly of 60S ribosomal subunits is perturbed in temperature-sensitive yeast mutants defective in ribosomal protein L16.  

Science Journals Connector (OSTI)

...temperature-sensitive yeast mutants defective in ribosomal protein L16...RIBOSOME ASSEMBLY MUTANTS DEFECTIVE FOR L16 5689 sis of the 35S...temperature (24). Strains car- rying mutations in the PRTI...assembled before the shift are not defective for function in translation...

M Moritz; B A Pulaski; J L Woolford Jr

1991-11-01T23:59:59.000Z

431

Four Moloney murine leukemia virus-infected rat cell clones producing replication-defective particles: protein and nucleic acid analyses.  

Science Journals Connector (OSTI)

...clones producing replication-defective particles: protein and nucleic...below. Viral proteins in the defective particles were labeled with...Fig. 3, lane B), the defective particles produced by the NX...respective marker proteins, car- bonic anhydrase (30K) and...

F K Yoshimura; J M Yamamura

1981-06-01T23:59:59.000Z

432

A mutant of Escherichia coli defective in penicillin-binding protein 5 and lacking D-alanine carboxypeptidase IA.  

Science Journals Connector (OSTI)

...preparation of D-alanrne car- boxypeptidase IA of...IA, because a mutant defective in D-alanine carbox...both activities were defective or both were normal...residual D-alanine car- boxypeptidase IA activity...and to obtain a mutant defective in PBP-6 are in progress...

Y Nishimura; H Suzuki; Y Hirota; J T Park

1980-07-01T23:59:59.000Z

433

Isolation and partial characterization of Rhodopseudomonas sphaeroides mutants defective in the regulation of ribulose bisphosphate carboxylase/oxygenase.  

Science Journals Connector (OSTI)

...Rhodopseudomonas sphaeroides Mutants Defective in the Regulation of Ribulose...Rhodopseudomonas sphaeroides defective in the derepres- sion of the...indicated that mutants were defective in the regulation of only one...pJB4JI, a "suicide" plasmid car- rying TnS (1), and pRK340...

K E Weaver; F R Tabita

1983-11-01T23:59:59.000Z

434

Cisplatin-resistant cancer cells are defective in the 26S proteasome: applications in cancer gene therapy  

Science Journals Connector (OSTI)

...Cisplatin-resistant cancer cells are defective in the 26S proteasome: applications...was excluded by analyzing for CAR receptor, alphavbeta3 and...19S and 20S subunits might be defective in 2008/C13* cells. Subsequent...CDDP-resistant tumor cells are defective in 26S proteasome and are sensitive...

Began Gopalan; Carlos Rached; Sunil Chada; and Rajagopal Ramesh

2006-04-15T23:59:59.000Z

435

Sites of copy choice replication involved in generation of vesicular stomatitis virus defective-interfering particle RNAs.  

Science Journals Connector (OSTI)

...Replication DNA Restriction Enzymes Defective Viruses genetics Genes, Viral...Vesicular Stomatitis Virus Defective-Interfering Particle RNAs...Celter, Diur liali,n Nor thl Car olina i 277102 Received 27...model for the generation of defective interfering (DI) particles...

E Meier; G G Harmison; J D Keene; M Schubert

1984-08-01T23:59:59.000Z

436

Transformation-defective mutant of adenovirus type 5 containing a single altered E1a mRNA species.  

Science Journals Connector (OSTI)

...H5in500 has been found to be defective in viral DNA replication and...acid residues (6). d1311 is defective for viral DNA replication...and yet the removal of the car- boxy-terminal residues...VIROL. TRANSFORMATION-DEFECTIVE MUTANT OF Ad5 663 transformation...

L R Carlock; N C Jones

1981-12-01T23:59:59.000Z

437

Genetic and biochemical analysis of transformation-competent, replication-defective simian virus 40 large T antigen mutants.  

Science Journals Connector (OSTI)

...transformation-competent, replication-defective simian virus 40 large T antigen...antigen which is replica- tion defective; it contains the lysine-to-glutamic...exhibited tI replication-defective phenotype in marker res ments...C8 T antigen lacks the 49 car nal amino acids and has a predicted...

M M Manos; Y Gluzman

1985-01-01T23:59:59.000Z

438

Society Evaluation of point defect concentrations in B2-FeAl intermetallic compound  

E-Print Network (OSTI)

Thermal defects are studied for three compositions (49, 50 and 52 at.%Fe) of the intermetallic compound FeAl with B2 structure. Magnetic measurements are used to determine the thermal defect concentrations. These concentrations are determined from fitting the experimental curves of magnetic susceptibility, obtained during an isochronal annealing after a quench. Next we have evaluated theoretically the concentrations of different point defects that exist in this compound. The used model is based in the Bragg-Williams approximation assuming the nearest-neighbour interaction. The calculated concentrations describe well the experimental values. I.

S. Zaroual; O. Sassi; J. Aride; J. Bernardini; G. Moya; Suprieure Takaddoum; B. P. Rabat-morocco

2001-01-01T23:59:59.000Z

439

Defect motion and lattice pinning barriers in Josephson-junction ladders  

SciTech Connect

We study the motion of domain wall defects in a fully frustrated Josephson-junction ladder system, driven by small applied currents. For small system sizes, the energy barrier E{sub B} to the defect motion is computed analytically via symmetry and topological considerations. More generally, we perform numerical simulations directly on the equations of motion, based on the resistively-shunted junction model, to study the dynamics of defects, varying the system size. Coherent motion of domain walls is observed for large system sizes. In the thermodynamical limit, we find E{sub B}=0.1827 in units of the Josephson coupling energy.

Kang, H.; Lim, Jong Soo [Department of Physics and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Fortin, J.-Y. [Laboratoire de Physique Theorique, Universite Louis Pasteur, 67084 Strasbourg (France); Choi, J. [Department of Physics, Keimyung University, Daegu 704-701 (Korea, Republic of); Choi, M. Y. [Department of Physics and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)

2006-01-01T23:59:59.000Z

440

Structural defects in GaN revealed by Transmission Electron Microscopy  

SciTech Connect

This paper reviews the various types of structural defects observed by Transmission Electron Microscopy in GaN heteroepitaxial layers grown on foreign substrates and homoepitaxial layers grown on bulk GaN substrates. The structural perfection of these layers is compared to the platelet self-standing crystals grown by High Nitrogen Pressure Solution. Defects in undoped and Mg doped GaN are discussed. Some models explaining the formation of inversion domains in heavily Mg doped layers that are possible defects responsible for the difficulties of p-doping in GaN are also reviewed.

Liliental-Weber, Zuzanna

2014-04-18T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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

Redox instability, mechanical deformation, and heterogeneous damage accumulation in solid oxide fuel cell anodes  

Science Journals Connector (OSTI)

Mechanical integrity and damage tolerance represent two key challenges in the design of solid oxide fuel cells(SOFCs). In particular reduction and oxidation(redox) cycles and the associated large transformation strains have a notable impact on the mechanical stability and failure mode of SOFCanodes. In this study the deformation behavior under redox cycling is investigated computationally with an approach that provides a detailed microstructurally based view of heterogeneous damage accumulation behavior within an experimentally obtained nickel/yttria stabilized zirconia SOFCanode microstructure. Simulation results underscore the critical role that the microstructure plays in the mechanical deformation behavior of and failure within such materials.

F. Abdeljawad; G. J. Nelson; W. K. S. Chiu; M. Haataja

2012-01-01T23:59:59.000Z

442

PROPERTIES OF DEFECTS AND IMPLANTS IN Mg+ IMPLANTED SILICON CARBIDE  

SciTech Connect

As a candidate material for fusion reactor designs, silicon carbide (SiC) under high-energy neutron irradiation undergoes atomic displacement damage and transmutation reactions that create magnesium as one of the major metallic products. The presence of Mg and lattice disorder in SiC is expected to affect structural stability and degrade thermo-mechanical properties that could limit SiC lifetime for service. We have initiated a combined experimental and computational study that uses Mg+ ion implantation and multiscale modeling to investigate the structural and chemical effects in Mg implanted SiC and explore possible property degradation mechanisms.

Jiang, Weilin; Zhu, Zihua; Varga, Tamas; Bowden, Mark E.; Manandhar, Sandeep; Roosendaal, Timothy J.; Hu, Shenyang Y.; Henager, Charles H.; Kurtz, Richard J.; Wang, Yongqiang

2013-09-25T23:59:59.000Z

443

Center for the Computational Design of Functional Layered Materials...  

Office of Science (SC) Website

solar (photovoltaic), energy storage (including batteries and capacitors), hydrogen and fuel cells, defects, mechanical behavior, materials and chemistry by design, synthesis...

444

Figure 1. Ankle behavior can be approximated by a linear torsional spring in the progression stage of the stance phase of normal gait.  

E-Print Network (OSTI)

Figure 1. Ankle behavior can be approximated by a linear torsional spring in the progression stage of the stance phase of normal gait. Abstract--In this paper we explore the mechanical behavior of the ankle in the progression stage of stance during normal walking. We show that the torque/angle behavior of the ankle during

Dollar, Aaron M.

445

Mechanical & Industrial Engineering  

E-Print Network (OSTI)

Mechanical & Industrial Engineering Mario A. Rotea Professor and Department Head #12;2Mechanical & Industrial Engineering Outline · Undergraduate Degree Programs · Graduate Degree Programs · The Faculty · The Research · Summary #12;3Mechanical & Industrial Engineering Undergraduate Programs ­ BSME & BSIE 0 20 40 60

Mountziaris, T. J.

446

Mechanical engineering Department Seminar  

E-Print Network (OSTI)

Mechanical engineering Department Seminar Shuodao Wang Postdoctoral Fellow University of Illinois, Urbana-Champaign Mechanical Design and Fabrication Techniques for Bio-Electronic Systems 11:00 AM Friday that bridge this gap in mechanics and form will create new opportunities in bio-inspired and bio

Lin, Xi

447

Mechanical and Aerospace Engineering  

E-Print Network (OSTI)

Mechanical and Aerospace Engineering Abstract Solid materials used in energy conversion and storage that couples the mechanical and chemical (or electrochemical) fields in solids via the use of stress-chemo- mechanical theory, two examples of practical interest will be discussed, namely, solid oxide fuel cells

448

Mechanical engineering Department Seminar  

E-Print Network (OSTI)

Mechanical engineering Department Seminar Maureen Lynch Postdoctoral Fellow Cornell University Mechanical Loading Decreases Osteolysis and Tumor Formation via Effects on Bone Remodeling 11:00 AM Friday to mechanical stimuli in the skeleton, yet the role of biomechanical loading remains poorly characterized

Lin, Xi

449

Victor Yakhot Mechanical Engineering  

E-Print Network (OSTI)

to flows of strongly non-linear fluids relevant for mechanical engineering, polymers and bio-fluid dynamicsVictor Yakhot Mechanical Engineering UniversalReynoldsNumberofTransition,Renormalizationand Mechanical Engineering 11 AM Friday, October 31st Room 245, 110 Cummington Mall Refreshments served at 10

Lin, Xi

450

A study of local and extended migration of H and defects in a-Si by molecular dynamics simulations  

SciTech Connect

The author reports on extensive molecular dynamics (MD) simulations on a-Si:H for up to 5 Ps using the ab initio code of Sankey and Drabold. The supercells contain about 70 atoms and only one defect in order to minimize defect-defect interaction. Simulations on supercell samples that originally contain one bond centered (BC) H in an otherwise defect free sample exhibit BC to BC diffusion as in c-Si. However, the author also observed localized motion of defects and H atoms on a very fast time scale that probably has been observed in several experiments.

Fedders, P.A. [Washington Univ., St. Louis, MO (United States). Dept. of Physics

1996-12-31T23:59:59.000Z

451

Correlation between nuclear response and defects in CZT  

SciTech Connect

Vertical high pressure Bridgman (VHPB) was considered until now to be the most successful crystal growth method to produce Cd{sub 1{minus}x}Zn{sub x}Te (CZT), (0.04 < x < 0.24), for X- and gamma-ray detector crystals. Recently Horizontal Bridgman (HB) Cd{sub 1{minus}x}Zn{sub x}Te crystals produced by IMARAD Co. have also been successfully fabricated into nuclear spectroscopic radiation detectors. In view of the database of many years' study of the electrical properties of VHPB CZT grown and obtained from various sources, the authors also studied the HB CZT crystals in order to compare the defects present in both different kinds of crystals grown by different methods. The VHB-grown samples were examined using thermoelectric emission spectroscopy (TEES), X- and gamma ray spectroscopy and laser induced transient charge technique (TCT). The surface and the bulk crystalline homogeneity were mapped using triaxial double crystal x-ray diffraction (TADXRD) and infrared transmission spectroscopy (IR). They have found a correlation between crystallinity, IR transmission microstructure and trapping times. Spectrometer grade VHPB CZT crystals exhibit trapping times of 20 {micro}s for electrons and 7 {micro}s for holes, however, regions, which were opaque to IR transmission, had trapping times shorter by one order of magnitude. The trapping times of HB CZT for electrons, were 10--15 {micro}s. A similar trend has been observed on VHPB CZT crystals with poor crystallinity. The HB CZT crystals that they measured in this study had a crystallinity that was inferior to that of the best spectroscopic grade VHPB crystals.

H. Hermon; M. Schieber; R. B. James; E. Lee; E. Cross; M. Goorsky; T. Lam; T. E. Schlesinger; M. Greaves

1999-07-19T23:59:59.000Z

452

Fracture behavior of high-burnup spent-fuel cladding  

SciTech Connect

PCI-like, brittle-type failures, characterized by pseudocleavage-plus-fluting features in the fracture surface, branching cracks, and small diametral strain, were observed to occur at 292 to 325/sup 0/C in some batches of spent power-reactor fuel-cladding tubes under internal gas-pressurization and expanding-mandrel loading conditions in which the tests were not influenced by fission product simulants. Fractographic characteristics per se do not provide evidence for a PCI failure mechanism but should be deemed only as cooroborative in nature. Evaluation of TEM thin-foil specimens, obtained from regions adjacent to the brittle-type fracture sites, characteristically revealed extensive amounts of Zr/sub 3/O precipitates and a lack of slip dislocations. The precipitation of the Zr/sub 3/O phase appears to be enhanced by a high density of irradiation-induced defects. The brittle-type failure produced in the spent-fuel cladding tubes appears to be associated with segregation of oxygen to dislocation substructures and irradiation-induced defects, which leads to the formation of an ordered zirconium-oxygen phase of Zr/sub 3/O, an immobilization of dislocations, and minimal plastic deformation in the cladding material.

Chung, H.M.; Yaggee, F.L.; Kassner, T.F.

1983-10-01T23:59:59.000Z

453

Mechanics of graded wrinkling  

E-Print Network (OSTI)

The properties of a surface depend on the inherent material and the surface topography. Nature uses surface texture as a means to impact different surface behavior such as cleanliness, adhesion control, drag reduction, ...

Raayai Ardakani, Shabnam

2013-01-01T23:59:59.000Z

454

Low cycle fatigue behavior of Zircaloy-2 at room temperature  

Science Journals Connector (OSTI)

Abstract Fuel cladding and pressure tubes of Zircaloy-2 in pressurized light and heavy water nuclear reactors experience plastic strain cycles due to power fluctuations in the reactor, such strain cycles cause low cycle fatigue (LCF) and could be life limiting factor for them. Factors like strain rate, strain amplitude and temperature are known to have marked influence on LCF behavior. The effect of strain rate from 10?2 to 10?4s?1 on LCF behavior of Zircaloy-2 was studied, at different strain amplitudes between 0.50% and 1.25% at room temperature. Fatigue life was decreased with lowering of strain rate from 10?2 to 10?4s?1 at all the strain amplitudes studied. While there was cyclic softening at lower strain amplitudes (??t/2?0.60%) cyclic hardening was exhibited at higher strain amplitudes (??t/2?1.00%) at all the strain rates. Further, there was secondary cyclic hardening during the later stage of cycling at all the strain amplitudes and the strain rates. Cyclic stressstrain hysteresis loops at the lowest strain rate of 10?4s?1 were found to be heavily serrated, resulting from dynamic strain aging (DSA). There was significant effect of strain rate on dislocation substructure. The results are discussed in terms of high concentration of point defects generated during cyclic straining and their role in enhancing interaction between solutes and dislocations.

G. Sudhakar Rao; J.K. Chakravartty; Saibaba Nudurupati; G.S. Mahobia; Kausik Chattopadhyay; N.C. Santhi Srinivas; Vakil Singh

2013-01-01T23:59:59.000Z

455

The mechanical properties of FeAl  

SciTech Connect

Only in the last few years has progress been made in obtaining reproducible mechanical properties data for FeAl. Two sets of observations are the foundation of this progress. The first is that the large vacancy concentrations that exist in FeAl at high temperature are easily retained at low temperature and that these strongly affect the low-temperature mechanical properties. The second is that RT ductility is adversely affected by water vapor. Purpose of this paper is not to present a comprehensive overview of the mechanical properties of FeAl but rather to highlight our understanding of key phenomena and to show how an understanding of the factors which control the yield strength and fracture behavior has followed the discovery of the above two effects. 87 refs, 9 figs.

Baker, I. [Dartmouth Coll., Hanover, NH (United States); George, E.P. [Oak Ridge National Lab., TN (United States)

1996-12-31T23:59:59.000Z

456

Joint Summer School on "The Evolution and Impact of Microstructural Defects  

Office of Science (SC) Website

Joint Summer School on "The Evolution and Impact Joint Summer School on "The Evolution and Impact of Microstructural Defects on In-Reactor Material Response" Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights News & Events EFRC News EFRC Events DOE Announcements Publications Contact BES Home 11.08.10 Joint Summer School on "The Evolution and Impact of Microstructural Defects on In-Reactor Material Response" Print Text Size: A A A Subscribe FeedbackShare Page June 6 - 10, 2011 :: The International Summer School, "The Evolution and Impact of Microstructural Defects on In-Reactor Material Response", at Idaho National Laboratories will be sponsored by the Center for Materials Science of Nuclear Fuel (Idaho National Laboratory), the Center for Defect

457

Hydrogen effects on the point defect spectrum in Fe-C alloys  

E-Print Network (OSTI)

As part of a multi-scale approach for modeling hydrogen embrittlement in hardened steels we have investigated, employing density functional theory methods, the stability and concentrations of the point defect clusters ...

Monasterio Velsquez, Paul Rene

2008-01-01T23:59:59.000Z

458

E-Print Network 3.0 - aging-related chromatin defects Sample...  

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

temperature... Research Fund tion at ARS elements in cells carrying defective ORC2Lincoln's Inn Fields and ORC5 (Fox et al... United Kingdom yeast silent mating-type...

459

Effects of Point Defects and Impurities on Kinetics in NaAlH4  

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

A presentation showing that point defects play an important role in the kinetics of NaAlH4 including vacancies and interstitials consistent with observed effects of Ti.

460

Integrated approaches to elucidate the genetic architecture of congenital heart defects  

E-Print Network (OSTI)

Congenital heart defects (CHD) are structural anomalies affecting the heart, are found in 1% of the population and arise during early stages of embryo development. Without surgical and medical interventions, most of the severe CHD cases would...

Al Turki, Saeed

2014-02-04T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" 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.


461

Strangulated hernia through a defect in the broad ligament: a sheep in wolfs clothing  

Science Journals Connector (OSTI)

Small bowel obstruction due to an internal hernia is an uncommon finding and, when caused by a defect in the broad ligament, it is exceptionally rare. This condition should be considered when evaluating all fe...

R. C. Langan; K. Holzman; M. Coblentz

2012-08-01T23:59:59.000Z

462

Detection of defects in FRP-reinforced concrete with the acoustic-laser vibrometry method  

E-Print Network (OSTI)

Fiber-reinforced polymer (FRP) strengthening and retrofitting of concrete structural elements has become increasingly popular for civil infrastructure systems. When defects occur in FRP-reinforced concrete elements at the ...

Chen, Justin Gejune

2013-01-01T23:59:59.000Z

463

Evaluation and Visualization of Surface Defects a Numerical and Experimental Study on Sheet?Metal Parts  

Science Journals Connector (OSTI)

The ability to predict surface defects in outer panels is of vital importance in the automotive industry especially for brands in the premium car segment. Today measures to prevent these defects can not be taken until a test part has been manufactured which requires a great deal of time and expense. The decision as to whether a certain surface is of acceptable quality or not is based on subjective evaluation. It is quite possible to detect a defect by measurement but it is not possible to correlate measured defects and the subjective evaluation. If all results could be based on the same criteria it would be possible to compare a surface by both FE simulations experiments and subjective evaluation with the same result.

A. Andersson

2005-01-01T23:59:59.000Z

464

Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations  

E-Print Network (OSTI)

For successful identification of structural defects in plates and pipes, it is essential to understand structural wave propagation characteristics such as dispersion relations. Analytical approaches to identify the dispersion relations...

Han, Je Heon

2013-07-31T23:59:59.000Z

465

Laser-Directed Hierarchical Assembly of Liquid Crystal Defects and Control of Optical Phase Singularities  

SciTech Connect

Topological defect lines are ubiquitous and important in a wide variety of fascinating phenomena and theories in many fields ranging from materials science to early-universe cosmology, and to engineering of laser beams. However, they are typically hard to control in a reliable manner. Here we describe facile erasable 'optical drawing' of self-assembled defect clusters in liquid crystals. These quadrupolar defect clusters, stabilized by the medium's chirality and the tendency to form twisted configurations, are shaped into arbitrary two-dimensional patterns, including reconfigurable phase gratings capable of generating and controlling optical phase singularities in laser beams. Our findings bridge the studies of defects in condensed matter physics and optics and may enable applications in data storage, singular optics, displays, electro-optic devices, diffraction gratings, as well as in both optically- and electrically-addressed pixel-free spatial light modulators.

Ackerman, P. J.; Qi, Z. Y.; Lin, Y. H.; Twombly, C. W.; Laviada, M. J.; Lansac, Y.; Smalyukh, I. I.

2012-06-07T23:59:59.000Z

466

Image contrast range for detection of enamel defects using a digital dental imaging system  

Science Journals Connector (OSTI)

The purpose of this study was to quantitatively assess the acceptable range of image contrast for the detection of enamel defects by adjusting the contrast and brightness of a digital dental imaging system. Ex...

Hiromi Kitagawa D.D.S.; Ph.D.; Mamoru Wakoh D.D.S.; Ph.D.

1999-12-01T23:59:59.000Z

467

An analytical study of rail grinding optimization for rail-head fatigue defect prevention  

E-Print Network (OSTI)

and increased train traffic on the remaining routes. These changes in railroad industry practice have caused an increase in the rate of occurrence of rail head fatigue defects, one potential cause of train derailment. The primary form of maintenance employed...

Jones, Scott Laurence

1997-01-01T23:59:59.000Z

468

Ab initio calculations on magnetism induced by composite defects in magnesium oxide  

SciTech Connect

The local magnetic state induced by the composite defects, composed of an oxygen vacancy and a nitrogen substituting oxygen, in magnesium oxide has been studied by using ab initio calculation based on density functional theory. The calculated results show that local magnetic moment can be induced by the composite defects around the oxygen vacancy, when the exchange split of the oxygen vacancy is enhanced either by the hybridization between the N-p and nearest neighbor O-p orbitals or by applying on-site Coulomb repulsion (U) and exchange interaction (J). We show that the magnetic state induced by the composite defect is energetically more stable than the non-magnetic state. In addition, we show that the U and J applied on the p-orbitals of N and O atoms may significantly impact the calculated magnetic state of the composite defect, resulting in magnetic state for a configuration that is non-magnetic by generalized gradient approximation.

Zhang, Yao-Fang [Department of Physics, Tianjin Polytechnic University, Tianjin 300384 (China); College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China); Feng, Min [School of Physics, Nankai University, Tianjin 300071 (China); Shao, Bin [Department of Physics, Tsinghua University, Beijing 100084 (China); Lu, Yuan; Zuo, Xu, E-mail: xzuonku@gmail.com [College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China); Liu, Hong [Office of International Academic Exchanges, Nankai University, Tianjin 300071 (China)

2014-05-07T23:59:59.000Z

469

Defect engineering in implantation technology of silicon light-emitting structures with dislocation-related luminescence  

Science Journals Connector (OSTI)

Results obtained in development of physical foundations of ion implantation technology for fabrication of silicon light- ... . The development of the concept of defect engineering in the technology of semiconduct...

N. A. Sobolev

2010-01-01T23:59:59.000Z

470

Real-Time Tracking and Shape Analysis of Atrial Septal Defects in 3D Echocardiography1  

E-Print Network (OSTI)

heart procedures. Our application assists pediatric atrial septal defect (ASD) closure techniques using.G.L., R.D.H.); National Institutes of Health, Diag- nostic Radiology Department, Bethesda, MD (M

471

Defect-Band Emission Photoluminescence Imaging on Multi-Crystalline Si Solar Cells: Preprint  

SciTech Connect

Defect-band photoluminescence (PL) imaging with an InGaAs camera was applied to multicrystalline silicon (mc-Si) wafers, which were taken from different heights of different Si bricks. Neighboring wafers were picked at six different processing steps, from as-cut to post-metallization. By using different cut-off filters, we were able to separate the band-to-band emission images from the defect-band emission images. On the defect-band emission images, the bright regions that originate from the grain boundaries and defect clusters were extracted from the PL images. The area fraction percentage of these regions at various processing stages shows a correlation with the final cell electrical parameters.

Yan, F.; Johnston, S.; Zaunbrecher, K.; Al-Jassim, M.; Sidelkheir, O.; Blosse, A.

2011-07-01T23:59:59.000Z

472

Boron-Silicon complex defects in GaAs: An ab initio study  

Science Journals Connector (OSTI)

First principles calculations have been performed to investigate defect equilibria of the siliconboron pair complex (SiB) in a GaAs matrix. For several charge states the formation energies were evaluated within the CarParrinello scheme considering cation and anion substitutional site defects. The calculations including the full relaxation of all ionic coordinates investigate native defects and isolated substitutional silicon (Si) and boron (B) impurities. The obtained formation energies are used to calculate the impurity concentration for different growth conditions. These results can be used to estimate the effect of different thermal profiles on the distribution and electrical state of Si and B defects which is interesting for classical process simulations.

R. Leitsmann; F. Chicker; Ph. Plnitz; C. Radehaus; U. Kretzer; M. Scheffer-Czygan; S. Eichler

2011-01-01T23:59:59.000Z

473

Classification and Reconstruction of Defects by Combined Acoustical Holography and Line-Saft  

Science Journals Connector (OSTI)

For the purpose of defect location, sizing and characterization a couple of analyzing nondestructive testing methods have been developed. Here a data acquisition system is presented which is based upon data co...

V. Schmitz; W. Mller; G. Schfer

1983-01-01T23:59:59.000Z

474

Water conservation behavior in Australia  

Science Journals Connector (OSTI)

Ensuring a nation's long term water supply requires the use of both supply-sided approaches such as water augmentation through water recycling, and demand-sided approaches such as water conservation. Conservation behavior can only be increased if the key drivers of such behavior are understood. The aim of this study is to reveal the main drivers from a comprehensive pool of hypothesized factors. An empirical study was conducted with 3094 Australians. Data was analyzed using multivariate linear regression analysis and decision trees to determine which factors best predict self-reported water conservation behavior. Two key factors emerge: high level of pro-environmental behavior; and pro-actively seeking out information about water. A number of less influential factors are also revealed. Public communication strategy implications are derived.

Sara Dolnicar; Anna Hurlimann; Bettina Grn

2012-01-01T23:59:59.000Z

475

PUBLISHED ONLINE: 6 JULY 2014 | DOI: 10.1038/NPHYS3006 Solids between the mechanical extremes of order  

E-Print Network (OSTI)

extremes of order and disorder Carl P. Goodrich1 *, Andrea J. Liu1 and Sidney R. Nagel2 For more than meaningful sense as a defected crystal2 . Is there an opposite extreme to a crystal--a solid with complete extreme limits of mechanical behaviour. Thus, the physics of jamming can be set side by side

Loss, Daniel

476

Point Defects in CdZnTe Crystals Grown by Different Techniques  

SciTech Connect

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps energies and densities.

R Gul; A Bolotnikov; H Kim; R Rodriguez; K Keeter; Z Li; G Gu; R James

2011-12-31T23:59:59.000Z

477

Point Defects in CdZnTe Crystals Grown by Different Techniques  

SciTech Connect

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps energies and densities.

Gul, R.; Bolotnikov, A.; Kim, H.K.; Rodriguez, R.; Keeter, K.; Li, Z.; Gu, G.; and James, R.B.

2011-02-02T23:59:59.000Z

478

Electron spin resonance study of proton-irradiation-induced defects in graphite  

SciTech Connect

Electron spin resonance measurements of proton-irradiated graphite have revealed detailed nature of proton-irradiation-induced defects. Our results indicate that proton-irradiation creates confined defect regions of a metallic island surrounded by an insulating magnetic region which ''isolates'' the metallic island inside from the metallic graphite background outside. We have thus come up with a picture of phase separation in proton-irradiated graphite comprising three regions of distinct electrical and magnetic properties.

Won Lee, Kyu; Kweon, H.; Kweon, J. J.; Lee, Cheol Eui [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of)

2010-02-15T23:59:59.000Z

479

Effects of time constraint and percent defective on visual inspection performance  

E-Print Network (OSTI)

EFFECTS OF TIME CONSTRAINT AND PERCENT DEFECTIVE ON VISUAL INSPECTION PERFORMANCE A Thesis by WALTER EDGAR GILMORE II Submitted to the Graduate College of Texas ABM University in partial fulfillment of the requirement for the degree MASTER... OF SCIENCE August 1982 Major Subject: Industrial Engineering EFFECTS OF TIME CONSTRAINT AND PERCENT DEFECTIVE ON VISUAL INSPECTION PERFORMANCE A Thesis by WALTER EDGAR GILMORE II Approved as to sty1e and content by: Chairman of Committ e) (Memb r...

Gilmore, Walter Edgar

2012-06-07T23:59:59.000Z

480

Anisotropic behavior and rupture of hydrided Zircaloy-4 sheets  

SciTech Connect

In a French pressurized water reactor (PWR), most of the structural parts of the fuel assembly consist of zirconium alloys (ZIRCALOY-2). The mechanical behavior of ZIRCALOY-4 sheets is investigated at room temperature. The effect of hydride precipitation on the mechanical behavior and on the rupture mechanism is also studied, in the range from 200 to 1,200 wt ppm hydrogen and for different stress triaxialities. It is shown that the material exhibits a strong anisotropy die to its pronounced texture, and that its mechanical properties depend on the strain rate. Hydride precipitation appears to have no effect on the anisotropy or on the strain-rate sensitivity, in the range from 10{sup {minus}4} to 10{sup {minus}2} s{sup {minus}1}. The main effect of hydrogen is the reduction of the ductility and of crack resistance. The ductile rupture mechanism is studied, focusing on the stage of damage nucleation by hydride fracture. Observations during scanning electron microscopy (SEM) in situ tests show that hydrides allow the transmission of slip, which occurs in ZIRCALOY-4 grains. Hydrides can also deform, together with surrounding zirconium matrix. Damage appears after a plastic-strain yield of about 14 to 25 pct. Fracture occurs first on intergranular hydrides. Fracture of transgranular hydrides is observed only prior to failure, for higher plastic strains.

Grange, M.; Besson, J.; Andrieu, E.

2000-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "defects mechanical behavior" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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481

Mechanical seal assembly  

DOE Patents (OSTI)

An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

Kotlyar, Oleg M. (Salt Lake City, UT)

2001-01-01T23:59:59.000Z

482

Mechanical seal assembly  

DOE Patents (OSTI)

An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transfering it to the mechanical diode.

Kotlyar, Oleg M. (Salt Lake City, UT)

2002-01-01T23:59:59.000Z

483

A nanocrystal strain gauge for luminescence detection of mechanical forces  

SciTech Connect

Local microscale stresses play a crucial role in inhomogeneous mechanical processes from cell motility to material failure. However, it remains difficult to spatially resolve stress at these small length scales. While contact-probe and non-contact based techniques have been used to quantify local mechanical behavior in specific systems with high stiffness or stress and spatial resolution, these methods cannot be used to study a majority of micromechanical systems due to spectroscopic and geometrical constraints. We present here the design and implementation of a luminescent nanocrystal strain gauge, the CdSe/CdS core/shell tetrapod. The tetrapod can be incorporated into many materials, yielding a local stress measurement through optical fluorescence spectroscopy of the electronically confined CdSe core states. The stress response of the tetrapod is calibrated and utilized to study mechanical behavior in single polymer fibers. We expect that tetrapods can be used to investigate local stresses in many other mechanical systems.

Choi, Charina; Koski, Kristie; Olson, Andrew; Alivisatos, Paul

2010-07-26T23:59:59.000Z

484

Structure and transformation of the metastable boron- and oxygen-related defect center in crystalline silicon  

Science Journals Connector (OSTI)

We analyze the core structure of the carrier-lifetime-reducing boron- and oxygen-related metastable defect center in crystalline silicon by measuring the correlation of the defect concentration with the boron and the oxygen contents on a large number of different silicon materials. The experimental results indicate that the defect is composed of one substitutional boron and two interstitial oxygen atoms. Formation and annihilation of the metastable boron-oxygen complex are found to be thermally activated processes, characterized by two strongly differing activation energies. Measurements of the defect generation rate as a function of light intensity show that the defect generation rate increases proportionally with light intensity below 1 mW/cm2 and saturates at higher intensities. All experimental results can be consistently explained using a defect reaction model based on fast-diffusing oxygen dimers (O2i), which are captured by substitutional boron (Bs) to form a metastable Bs-O2i complex. Based on this model, new strategies for an effective reduction of the light degradation of solar cells made on oxygen-rich silicon materials are derived. The model also explains why no lifetime degradation is observed in aluminum-, gallium-, and indium-doped oxygen-rich silicon.

Jan Schmidt and Karsten Bothe

2004-01-22T23:59:59.000Z

485

Evaluation of the association between birth defects and exposure to ambient vinyl chloride  

SciTech Connect

Birth defects incidence for infants born to residents of Shawinigan, Canada in 1966-1979 were significantly higher than in three comparison communities. Since there has been a vinyl chloride polymerization plant in this town since 1943 from which ten cases of angiosarcoma of the liver have been identified, this study explores the possible association between exposure to vinyl chloride monomer (VCM) in ambient air and the occurrence of birth defects in the community. The excess of birth defects fluctuated seasonally in a way that corresponded to changes in VCM concentration in the environment. Mothers who gave birth to malformed children were younger on average in Shawinigan than in the comparison communities. However, there was no excess of still-births in Shawinigan. The excess in birth defects involved most organ systems, and variation in birth-defect rates among school districts could not be accounted for by estimates of VCM in the atmosphere. The occupational and residential histories of parents who gave birth to malformed infants were compared with those of parents of normal infants. The two groups did not differ in occupational exposure or closeness of residence to the vinyl chloride polymerization plant. Some descriptive data from this study raised the hypothesis of an association between VCM in the air and birth defects in the exposed community, but as a whole, within the sample size available, such an association could not be substantiated.

Theriault, G.; Iturra, H.; Gingras, S.

1983-06-01T23:59:59.000Z

486

Evaluation on defect in the weld of stainless steel materials using nondestructive technique  

Science Journals Connector (OSTI)

Abstract The objective of this study is to evaluate the elastic wave's characteristic on the crack in the weld of stainless steel materials using guided wave and acoustic emission, nondestructive tests. The stainless steel is expected as candidate of structural piping material under high temperature condition in nuclear fusion instrument, and a tungsten inert gas (TIG) weld technique was applied for making its jointing. The defect size of 20mm was induced in the weld material. The guided wave, one of elastic waves, can propagate through very long pipe, and easily change to lots of modes by the defects in the structure. By analyzing the relationship between the mode conversion and the defects we can evaluate existing of the defects in weld material. In present study Nd-YAG laser was used to excite the guided wave by non-contact method, and AE technique was also used to clarify the mode conversion of guided wave by defect because lots of AE parameters of energy, count and amplitude can give more chances for analysis of mode conversion. The optimal AE parameters for the evaluation of the defects in weld zone using laser guided wave were derived.

Jin Kyung Lee; Dong Su Bae; Sang Pill Lee; Joon Hyun Lee

2014-01-01T23:59:59.000Z

487

Advanced Neutron Source Reactor thermal analysis of fuel plate defects  

SciTech Connect

The Advanced Neutron Source Reactor (ANSR) is a research reactor designed to provide the highest continuous neutron beam intensity of any reactor in the world. The present technology for determining safe operations were developed for the High Flux Isotope Reactor (HFIR). These techniques are conservative and provide confidence in the safe operation of HFIR. However, the more intense requirements of ANSR necessitate the development of more accurate, but still conservative, techniques. This report details the development of a Local Analysis Technique (LAT) that provides an appropriate approach. Application of the LAT to two ANSR core designs are presented. New theories of the thermal and nuclear behavior of the U{sub 3}Si{sub 2} fuel are utilized. The implications of lower fuel enrichment and of modifying the inspection procedures are also discussed. Development of the computer codes that enable the automate execution of the LAT is included.

Giles, G.E.

1995-08-01T23:59:59.000Z

488

Fracture mechanics analysis on the resistance of welded details under variable amplitude long life loading  

E-Print Network (OSTI)

Fracture mechanics approach has been used to analyze the behavior of fatigue resistance of welded details existing in highway steel bridges under variable amplitude long life loading which means most of the stress ranges will be below constant...

Zhou, Minjian

1993-01-01T23:59:59.000Z

489

The Role of Androgens in Male Pregnancy and Female Competitive Behavior in a Sex Role Reversed Pipefish  

E-Print Network (OSTI)

hormonal mechanisms that mediate female competitive behavior and male pregnancy. New methodologies and better husbandry practices have made such studies more feasible in recent years. Research on a relatively small number of species has suggested...

Scobell, Sunny Kay

2012-02-14T23:59:59.000Z

490

Interactions between X-ray induced transient defects and pre-existing damage precursors in DKDP crystals  

SciTech Connect

Large-aperture laser systems, currently designed to achieve high energy densities at the target location (exceeding {approx} 10{sup 11} J/m{sup 3}), will enable studies of the physics of matter and radiation under extreme conditions. As a result, their optical components, such as the frequency conversion crystals (KDP/DKDP), may be exposed to X-rays and other ionizing radiation. This in turn may lead to a change in the damage performance of these materials as they may be affected by radiation-induced effects by either forming new damage initiation centers or interacting with the pre-existing damage initiating defects (so-called damage precursors). We present an experimental study on the laser-induced bulk damage performance at 355-nm of DKDP crystals following X-ray irradiation at room temperature. Results indicate that the damage performance of the material is affected by exposure to X-rays. We attribute this behavior to a change in the physical properties of the precursors which, in turn, affect their individual damage threshold.

Negres, R A; Saw, C K; Demos, S G

2008-10-24T23:59:59.000Z

491

Mechanical Properties of Nanocrystal Supercrystals  

E-Print Network (OSTI)

and Its Impact on Mechanical Properties. MacromoleculesO. L. ; Minor, A. M. , Mechanical annealing and source-Mechanical Properties of Nanocrystal Supercrystals Enrico

Tam, Enrico

2010-01-01T23:59:59.000Z

492

Mechanics of Funding matrix  

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

FUNDING MECHANISMS FUNDING MECHANISMS Funding Mechanism Advantages Disadvantages Comments 1. From Doe to regional organizations * * Facilitates a broad, regional approach to planning and implementation that enhances consistency and uniformity * * Especially beneficial for new programs where early planning is needed * * Simplifies communication for DOE to have only one point of contact for information and discussion * * Cooperative agreement mechanism has proven relatively simple to administer * * Approach would require modification for Tribes * * Would also require that funding be provided to individual States to enable them to participate in the process, since planning authority and responsibility rests with the individual State * * Differs from OCRWM approach to 180(c) funding * * Introduces another layer of

493

Technology Partnering Mechanisms  

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

expand a business with INL technologies, or require business support our Technology Transfer team is available to discuss the following contractual mechanisms: Cooperative...

494

JointME&MSEColloquium The Department of Mechanical  

E-Print Network (OSTI)

for hydrogen embrittlement in iron, namely, hydrogen-enhanced localized plasticity (HELP) and hydrogen enhanced-type decohesion. This talk will be focused on assessing several key mechanistic aspects of hydrogen embrittlement finite element analysis, the deformation behavior and the underlying mechanisms of hydrogen embrittlement

Mills, Allen P.

495

Boston University Department of Mechanical Engineering ME 303 Fluid Mechanics  

E-Print Network (OSTI)

Boston University Department of Mechanical Engineering ME 303 ­ Fluid Mechanics Fall 2011 Class: EK301 Engineering Mechanics Course Textbook: Fundamentals of Fluid Mechanics, 6th ed., Munson B. Reference Texts: Fluid Mechanics, Landau and Lifshitz, Vol. 6 Fluid Mechanics, Y. Cengel and J. Cimbala

496

Chapter 17: Residential Behavior Protocol  

SciTech Connect

Residential behavior-based (BB) programs use strategies grounded in the behavioral social sciences to influence household energy use. Strategies may include providing households with real-time or delayed feedback about their energy use; supplying energy-efficiency education and tips; rewarding households for reducing their energy use; comparing households to their peers; and establishing games, tournaments, and competitions. BB programs often target multiple energy end uses and encourage energy savings, demand savings, or both. Savings from BB programs are usually a small percentage of energy use, typically less than 5%.

Stewart, J.; Todd, A.

2015-01-01T23:59:59.000Z

497

Mechanical & Aerospace Engineering  

E-Print Network (OSTI)

, and nuclear energy. She is a member of the American Society of Mechanical Engineers (ASME), Fluids EngineeringMechanical & Aerospace Engineering Interfacial flows are multi-material flows comprised of two of the interface between the fluids and the interface physics (like surface tension) needs to be predicted as part

498

MECHANICAL ENGINEERING Program of Study  

E-Print Network (OSTI)

MECHANICAL ENGINEERING Program of Study Correspondence The Department of Mechanical Engineering offers graduate programs in the fields of thermal science and engineering mechanics. Current areas of research activity include Biomedical Engineering, Biomimetics, Composite Materials, Computational Mechanics

Thomas, Andrew

499

Integrated Mechanical & Electrical Engineering (IMEE)  

E-Print Network (OSTI)

Integrated Mechanical & Electrical Engineering (IMEE) Department of Electronic & Electrical Engineering and Department of Mechanical Engineering #12;Graduates able to work in both mechanical of Mechanical Engineers (IMechE) n Develop essential engineering skills through extensive project work n Enhance

Burton, Geoffrey R.

500

Mechanical code comparator  

DOE Patents (OSTI)

A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

Peter, Frank J. (Albuquerque, NM); Dalton, Larry J. (Bernalillo, NM); Plummer, David W. (Albuquerque, NM)

2002-01-01T23:59:59.000Z