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Note: This page contains sample records for the topic "tiny crystals glow" 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
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1

New Family of Tiny Crystals Glow Bright in LED Lights | Advanced Photon  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of1,Department ofNewof NO2: Key Role

2

New family of tiny crystals glow bright in LED lights | ornl.gov  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory | NationalJohn CyberNeutrons usedDOENewNew exhibit highlightsNew

3

Oscillations in glow discharges  

E-Print Network [OSTI]

OSCILLATIONS IN GLOW DISCHARGES A Dissertation By Tom Prickett, Jr. June 1950 Approved as to style and content by Chairman of Committee OSCILLATIONS IN GLOW DISCHARGES A Dissertation By Tom Prickett, Jr* June 1950 OSCILLATIONS IN GLOW... 1950 CONTENTS Introduction ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 1 I. Review of Plasma Oscillations in Gas Discharges ? . . 2 II. Review of Relaxation Processes in Gas Discharges ? . 13 III. Report of Laboratory Investigation...

Prickett, Tom

1950-01-01T23:59:59.000Z

4

Glow discharge detector  

DOE Patents [OSTI]

A highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured.

Koo, Jackson C. (San Ramon, CA); Yu, Conrad M. (Antioch, CA)

2002-01-01T23:59:59.000Z

5

Powerful glow discharge excilamp  

DOE Patents [OSTI]

A powerful glow discharge lamp comprising two coaxial tubes, the outer tube being optically transparent, with a cathode and anode placed at opposite ends of the tubes, the space between the tubes being filled with working gas. The electrodes are made as cylindrical tumblers placed in line to one other in such a way that one end of the cathode is inserted into the inner tube, one end of the anode coaxially covers the end of the outer tube, the inner tube penetrating and extending through the anode. The increased electrodes' surface area increases glow discharge electron current and, correspondingly, average radiation power of discharge plasma. The inner tube contains at least one cooling liquid tube placed along the axis of the inner tube along the entire lamp length to provide cathode cooling. The anode has a circumferential heat extracting radiator which removes heat from the anode. The invention is related to lighting engineering and can be applied for realization of photostimulated processes under the action of powerful radiation in required spectral range.

Tarasenko, Victor F. (Tomsk, RU); Panchenko, Aleksey N. (Tomsk, RU); Skakun, Victor S. (Tomsk, RU); Sosnin, Edward A. (Tomsk, RU); Wang, Francis T. (Danville, CA); Myers, Booth R. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

2002-01-01T23:59:59.000Z

6

ORNL seeks to enhance tiny engine performance for military |...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

seeks to enhance tiny engine performance for military Oak Ridge National Laboratory engineers are trying to improve efficiency and performance in tiny engines in remote-controlled...

7

Tiny Glass Bubbles With Big Potential  

Broader source: Energy.gov [DOE]

If these glass microspheres' walls could talk…They would explain how their tiny pores allow the potential for handling, storing and transporting a variety of materials, including drugs that have...

8

Ordered dust structures in a glow discharge  

SciTech Connect (OSTI)

Highly ordered three-dimensional dust structures are created in a striated glow discharge, and their horizontal cross-sectional images are analyzed. Calculated correlation functions, local correlation parameters, and corresponding approximations are used to classify the state of a structure according to the Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) two-dimensional melting theory and a phenomenological approach. An orientational map based on an orientational parameter is proposed to expose domains in a cross section of a structure. It is shown that a plasma crystal is a polycrystal consisting of hexagonal domains (crystallites). Thermophoretic forces are used to create corners of various angles in the perimeter of the structure. Transition between hexagonal and square cell shapes is observed.

Karasev, V. Yu., E-mail: plasmadust@yandex.ru; Ivanov, A. Yu.; Dzlieva, E. S.; Eikhval'd, A. I. [St. Petersburg State University, Institute of Physics (Russian Federation)

2008-02-15T23:59:59.000Z

9

Constricted glow discharge plasma source  

DOE Patents [OSTI]

A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)

2000-01-01T23:59:59.000Z

10

Tiny Bubbles in my BEC  

SciTech Connect (OSTI)

Ultracold atomic gases provide a unique way for exploring many-body quantum phenomena that are inaccessible to conventional low-temperature experiments. Nearly two decades ago the Bose-Einstein condensate (BEC) - an ultracold gas of bosons in which almost all bosons occupy the same single-particle state - became experimentally feasible. Because a BEC exhibits superfluid properties, it can provide insights into the behavior of low-temperature helium liquids. We describe the case of a single distinguishable atom (an impurity) embedded in a BEC and strongly coupled to the BEC bosons. Depending on the strength of impurity-boson and boson-boson interactions, the impurity self-localizes into two fundamentally distinct regimes. The impurity atom can behave as a tightly localized 'polaron,' akin to an electron in a dielectric crystal, or as a 'bubble,' an analog to an electron bubble in superfluid helium. We obtain the ground state wavefunctions of the impurity and BEC by numerically solving the two coupled Gross-Pitaevskii equations that characterize the system. We employ the methods of imaginary time propagation and conjugate gradient descent. By appropriately varying the impurity-boson and boson-boson interaction strengths, we focus on the polaron to bubble crossover. Our results confirm analytical predictions for the polaron limit and uncover properties of the bubble regime. With these results we characterize the polaron to bubble crossover. We also summarize our findings in a phase diagram of the BEC-impurity system, which can be used as a guide in future experiments.

Blinova, Alina A. [Los Alamos National Laboratory

2012-08-01T23:59:59.000Z

11

Glow Plug Integrated Piezo-Ceramic Combustion Sensor for Diesel...  

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

Glow Plug Integrated Piezo-Ceramic Combustion Sensor for Diesel Engines Glow Plug Integrated Piezo-Ceramic Combustion Sensor for Diesel Engines 2005 Diesel Engine Emissions...

12

Atmospheric sampling glow discharge ionization source  

DOE Patents [OSTI]

An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

McLuckey, S.A.; Glish, G.L.

1989-07-18T23:59:59.000Z

13

Big energy savings in a tiny package  

SciTech Connect (OSTI)

PNL is developing microscale technologies to revolutionize energy use in homes, businesses and industry. One project is a miniature heat pump that is smaller than a dime. The pumps would be so small that hundreds or thousands could be manufactured in sheets, which could then be incorporated into the walls of buildings to replace conventional heat pumps, furnaces, air conditioners and ductwork. The tiny heat pumps could save much of the energy loss associated with conventional heatpump technology because of the elimination of the ductwork needed to carry air throughout the house. Like conventional heat pumps, micro heat pumps have an evaporator, a condenser and a compressor. PNL has developed a micro heat exchanger that serves as a condenser and evaporator. The heat exchangers are made with the same photo etching process used to make computer chips. Tiny channels are etched into a dime-sized piece of metal. Refrigerant flows through these channels and evaporates or condenses, and the heat is transferred to the outside.

Chambers, A.

1995-02-01T23:59:59.000Z

14

Glow discharge plasma deposition of thin films  

DOE Patents [OSTI]

A glow discharge plasma reactor for deposition of thin films from a reactive RF glow discharge is provided with a screen positioned between the walls of the chamber and the cathode to confine the glow discharge region to within the region defined by the screen and the cathode. A substrate for receiving deposition material from a reactive gas is positioned outside the screened region. The screen is electrically connected to the system ground to thereby serve as the anode of the system. The energy of the reactive gas species is reduced as they diffuse through the screen to the substrate. Reactive gas is conducted directly into the glow discharge region through a centrally positioned distribution head to reduce contamination effects otherwise caused by secondary reaction products and impurities deposited on the reactor walls.

Weakliem, Herbert A. (Pennington, NJ); Vossen, Jr., John L. (Bridgewater, NJ)

1984-05-29T23:59:59.000Z

15

Probiotic Bacteria Induce a ‘Glow of Health’  

E-Print Network [OSTI]

Radiant skin and hair are universally recognized as indications of good health. However, this ‘glow of health’ display remains poorly understood. We found that feeding of probiotic bacteria to aged mice induced integumentary ...

Levkovich, Tatiana

16

Tackling Big Challenges Using Tiny Crystals | Stanford Synchrotron...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Conference Room 108A Speaker: Matteo Cargnello, Stanford Univeristy Program Description Fossil fuels are not endless and their extensive use is causing irreversible climate...

17

Tiny Terminators: New Micro-Robots Assemble, Repair Themselves...  

Broader source: Energy.gov (indexed) [DOE]

Themselves and Are Surprisingly Strong August 8, 2011 - 2:14pm Addthis A video of Argonne National Laboratory's micro-robots - Tiny Terminators, if you will - moving glass...

18

TiNi shape memory alloy thin films for microactuator application  

E-Print Network [OSTI]

TiNi films were prepared by co-sputtering TiNi target and a separate Ti target. Crystalline structure and phase transformation behaviors of TiNi films were investigated. Results showed that TiNi films had fine grain size ...

Fu, Yongqing

19

E-Print Network 3.0 - awa-muatan pijar glow Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

where a stable open void 2... glow starts increasing and at nearly the same time, the void starts shrinking. Plasma glow reaches its... and central plasma glow during the...

20

atmospheric glow discharge: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

34 Glow Discharge Enhanced Chemical Reaction: Application in Ammonia Synthesis and Hydrocarbon Gas Cleanup Texas A&M University - TxSpace Summary: ......

Note: This page contains sample records for the topic "tiny crystals glow" 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

ablation glow discharge: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

29 Glow Discharge Enhanced Chemical Reaction: Application in Ammonia Synthesis and Hydrocarbon Gas Cleanup Texas A&M University - TxSpace Summary: ......

22

analytical glow discharge: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

29 Glow Discharge Enhanced Chemical Reaction: Application in Ammonia Synthesis and Hydrocarbon Gas Cleanup Texas A&M University - TxSpace Summary: ......

23

Source: http://tiny.cc/test-fear OnlineAlarm  

E-Print Network [OSTI]

chest pain during a heart attack? Learn more at the National Library of Medicine's heart attacks, help- ing to prevent them, subtle signs and symptoms, and not confusing heart attacks with other-healthy education training module - http://tiny.cc/love-your-heart. The sound/animation tutorial discusses heart

Oliver, Douglas L.

24

Phenomena of oscillations in atmospheric pressure direct current glow discharges  

SciTech Connect (OSTI)

Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transform spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.

Liu, Fu-cheng [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)] [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Yan, Wen; Wang, De-zhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-12-15T23:59:59.000Z

25

Deriving State Machines from TinyOS programs using Symbolic Execution  

E-Print Network [OSTI]

Sensing Deriving State Machines from TinyOS Programs usingconstraints Example State Machine: RfmToLed RfmToIntM.ncuser-understandable Finite State Machines (FSMs) from TinyOS

Kothari, Nupur; Millstein, Todd; Govindan, Ramesh

2009-01-01T23:59:59.000Z

26

Nexus Energy Center Raises Funds for Energy-Saving Tiny Home...  

Energy Savers [EERE]

Raises Funds for Energy-Saving Tiny Home Nexus Energy Center Raises Funds for Energy-Saving Tiny Home bbrnstoriesnexusenergy9-2-14.png Nexus Energy Center, a Huntsville,...

27

Entrainment by Spatiotemporal Chaos in Glow Discharge-Semiconductor Systems  

E-Print Network [OSTI]

Entrainment of limit cycles by chaos [1] is discovered numerically through specially designed unidirectional coupling of two glow discharge-semiconductor systems. By utilizing the auxiliary system approach [2], it is verified that the phenomenon is not a chaos synchronization. Simulations demonstrate various aspects of the chaos appearance in both drive and response systems. Chaotic control is through the external circuit equation and governs the electrical potential on the boundary. The expandability of the theory to collectives of glow discharge systems is discussed, and this increases the potential of applications of the results. Moreover, the research completes the previous discussion of the chaos appearance in a glow discharge-semiconductor system [3].

Marat Akhmet; Ismail Rafatov; Mehmet Onur Fen

2014-06-15T23:59:59.000Z

28

E-Print Network 3.0 - air mixture glow Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

lens lens razor to optical fiber to camera air He He flow glow turbulent mixing l agar d x z L... -size atmospheric-pressure glow-discharge plasma, or plasma ... Source:...

29

E-Print Network 3.0 - abnormal glow discharge Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Collection: Mathematics 24 Transition from Townsend to glow discharge: Subcritical, mixed, or supercritical characteristics Danijela D. Sijacic1 Summary: Transition...

30

HoustonChronicle.com -Tiny honor a big deal for algae scientist HoustonChronicle.  

E-Print Network [OSTI]

HoustonChronicle.com - Tiny honor a big deal for algae scientist HoustonChronicle. com Section-mail this story June 18, 2005, 5:48PM Tiny honor a big deal for algae scientist By DAVID A. FAHRENTHOLD Washington Post Sometimes, algae can be the highest form of flattery. ADVERTISEMENTSo it was for Diane K. Stoecker

Jeong, Hae Jin

31

Tiny camera could aid in robotics, night vision Monday, January 17, 2011  

E-Print Network [OSTI]

Tiny camera could aid in robotics, night vision Monday, January 17, 2011 Researchers from night-vision surveillance, robotic vision, endoscopic imaging, and consumer electronics. "We were on this article! 0 COMMENTS Page 1 of 1Tiny camera could aid in robotics, night vision | R&D Mag 1/19/2011http

Rogers, John A.

32

Geek-Up[6.24.11]: Dust-sized 'Dragonfly' Device and Tiny Microvalves  

Broader source: Energy.gov [DOE]

A dust-size "dragonfly-inspired" device -- which won a Sandia Lab design contest -- may ultimately enable the creation of tiny microvalves for experiments in biological research laboratories and medical facilities.

33

Tiny Terminators: New Micro-Robots Assemble, Repair Themselves and Are Surprisingly Strong  

Broader source: Energy.gov [DOE]

Tiny robots that can assemble and repair themselves? Watch a video of Argonne National Laboratory's micro-robots that easily perform tasks that can challenge other robots, including moving objects that are larger than themselves.

34

Sensitive glow discharge ion source for aerosol and gas analysis  

DOE Patents [OSTI]

A high sensitivity glow discharge ion source system for analyzing particles includes an aerodynamic lens having a plurality of constrictions for receiving an aerosol including at least one analyte particle in a carrier gas and focusing the analyte particles into a collimated particle beam. A separator separates the carrier gas from the analyte particle beam, wherein the analyte particle beam or vapors derived from the analyte particle beam are selectively transmitted out of from the separator. A glow discharge ionization source includes a discharge chamber having an entrance orifice for receiving the analyte particle beam or analyte vapors, and a target electrode and discharge electrode therein. An electric field applied between the target electrode and discharge electrode generates an analyte ion stream from the analyte vapors, which is directed out of the discharge chamber through an exit orifice, such as to a mass spectrometer. High analyte sensitivity is obtained by pumping the discharge chamber exclusively through the exit orifice and the entrance orifice.

Reilly, Peter T. A. (Knoxville, TN)

2007-08-14T23:59:59.000Z

35

The Use of DC Glow Discharges as Undergraduate Educational Tools  

SciTech Connect (OSTI)

Plasmas have a beguiling way of getting students excited and interested in physics. We argue that plasmas can and should be incorporated into the undergraduate curriculum as both demonstrations and advanced investigations of electromagnetism and quantum effects. Our device, based on a direct current (DC) glow discharge tube, allows for a number of experiments into topics such as electrical breakdown, spectroscopy, magnetism, and electron temperature.

Stephanie A. Wissel and Andrew Zwicker, Jerry Ross, and Sophia Gershman

2012-10-09T23:59:59.000Z

36

Transition from Townsend to glow discharge: Subcritical, mixed, or supercritical characteristics Danijela D. Sijacic1  

E-Print Network [OSTI]

Transition from Townsend to glow discharge: Subcritical, mixed, or supercritical characteristics, the transition from Townsend to glow discharge can show the textbook subcritical behavior, but for smaller values long discharges that have a clearly pronounced subcritical characteristics, i.e., for fixed large pd

Ebert, Ute

37

LANL Transfers Glowing Bio Technology to Sandia Biotech  

SciTech Connect (OSTI)

Partnering with Los Alamos National Laboratory, an Albuquerque-based company is seeking to transform the way protein and peptide analysis is conducted around the world. Sandia Biotech is using a biological technology licensed from Los Alamos called split green fluorescent protein (sGFP), as a detecting and tracking tool for the protein and peptide industry, valuable in the fields of Alzheimer's research, drug development and other biotechnology fields using protein folding to understand protein expression and mechanisms of action. http://www.lanl.gov/news/stories/glowing-future-for-los-alamos-and-sandia-b iotech-partnership.html

Rorick, Kevin

2012-01-01T23:59:59.000Z

38

LANL Transfers Glowing Bio Technology to Sandia Biotech  

ScienceCinema (OSTI)

Partnering with Los Alamos National Laboratory, an Albuquerque-based company is seeking to transform the way protein and peptide analysis is conducted around the world. Sandia Biotech is using a biological technology licensed from Los Alamos called split green fluorescent protein (sGFP), as a detecting and tracking tool for the protein and peptide industry, valuable in the fields of Alzheimer's research, drug development and other biotechnology fields using protein folding to understand protein expression and mechanisms of action. http://www.lanl.gov/news/stories/glowing-future-for-los-alamos-and-sandia-b iotech-partnership.html

Rorick, Kevin

2012-08-02T23:59:59.000Z

39

Interaction of a surface glow discharge with a gas flow  

SciTech Connect (OSTI)

A surface glow discharge in a gas flow is of particular interest as a possible tool for controlling the flow past hypersonic aircrafts. Using a hydrodynamic model of glow discharge, two-dimensional calculations for a kilovolt surface discharge in nitrogen at a pressure of 0.5 Torr are carried out in a stationary gas, as well as in a flow with a velocity of 1000 m/s. The discharge structure and plasma parameters are investigated near a charged electrode. It is shown that the electron energy in a cathode layer reaches 250-300 eV. Discharge is sustained by secondary electron emission. The influence of a high-speed gas flow on the discharge is considered. It is shown that the cathode layer configuration is flow-resistant. The distributions of the electric field and electron energy, as well as the ionization rate profile in the cathode layer, do not change qualitatively under the action of the flow. The basic effect of the flow's influence is a sharp decrease in the region of the quasineutral plasma surrounding the cathode layer due to fast convective transport of ions.

Aleksandrov, A. L., E-mail: a_alex@itam.nsc.ru; Schweigert, I. V. [Russian Academy of Sciences, Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch (Russian Federation)

2010-05-15T23:59:59.000Z

40

CoAP for the Web of Things: From Tiny Resource-constrained  

E-Print Network [OSTI]

scratch following the REST architectural style. Thus, its features are tailored for Internet of Things (Io-power devices and the Web of Things, as HTTP over TCP is not feasible in these environments. RESTful project, we extended the JavaScript language with an API for direct interaction with tiny IoT devices [9

Note: This page contains sample records for the topic "tiny crystals glow" 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

The corrosion behavior and hemocompatibility of TiNi alloys coated with DLC by plasma based ion implantation  

E-Print Network [OSTI]

The corrosion behavior and hemocompatibility of TiNi alloys coated with DLC by plasma based ion characteristics and corrosion resistant property as well as hemocompatibility has been investigated. The results measurement and SEM observation, we found that the uncoated TiNi alloy shows severe pitting corrosion, which

Zheng, Yufeng

42

Trace elements in coal by glow discharge mass spectrometry  

SciTech Connect (OSTI)

A need and a demand exist for determining trace elements in coal and coal related by-products, especially those elements which may potentially be a health hazard. The provisions of the 1990 clean air act require that the EPA evaluate the emissions of electric utilities for trace elements and other potentially hazardous organic compounds. The coal fired electric utility industry supplies roughly 60% of the total generating capacity of 2,882,525 million kilowatt hours (nearly 3 trillion kilowatt hours) generated in the U.S. This is accomplished by 414 power plants scattered across the country that burned 813,508,000 short tons of coal in 1993. The relative volatility of some inorganic constituents in coal makes them more prone to be emitted to the atmosphere following combustion. The production of analytical data for trace elements is known to be a difficult task in coal and by-products of coal combustion (fly ash, bottom ash, gas streams, etc.), in terms of both sample collection and analytical determinations. There are several common analytical methods available to the analyst to determine trace elements in coal and coal by-products. In general analytical germs, the material to be analyzed can be totally solubilized (or extracted), or the elements analytes can be determined in the material as a solid. A relatively new elemental technique, Glow Discharge Mass Spectrometry (GDMS) can be used with solids as well. This new analytical technique had never before been applied directly to coal. The radio frequency-glow discharge quadropole mass spectrometer was used to analyze coal directly for the first time ever by rf-GDMS. The rf-GDMS technique is described.

Jacobs, M.L.; Wilson, C.R.; Pestovich, J. Jr. [WAL Inc., Wheat Ridge, CO (United States)] [and others

1995-08-01T23:59:59.000Z

43

Microdischarge-assisted ignition of dielectric-barrier high-pressure glow discharges  

E-Print Network [OSTI]

in the ignition of high-pressure arc lamps8 and volume dc discharges.6 Here, we employ a hybrid discharge source of uniform, nonequilibrium glow plasmas for a variety of applications at pressures of 100

Raja, Laxminarayan L.

44

Dynamics of multiple double layers in high pressure glow discharge in a simple torus  

SciTech Connect (OSTI)

Parametric characterization of multiple double layers is done during high pressure glow discharge in a toroidal vessel of small aspect ratio. Although glow discharge (without magnetic field) is known to be independent of device geometry, but the toroidal boundary conditions are conducive to plasma growth and eventually the plasma occupy the toroidal volume partially. At higher anode potential, the visibly glowing spots on the body of spatially extended anode transform into multiple intensely luminous spherical plasma blob structures attached to the tip of the positive electrode. Dynamics of multiple double layers are observed in argon glow discharge plasma in presence of toroidal magnetic field. The radial profiles of plasma parameters measured at various toroidal locations show signatures of double layer formation in our system. Parametric dependence of double layer dynamics in presence of toroidal magnetic field is presented here.

Kumar Paul, Manash, E-mail: manashkr@gmail.com [Department of Physics, National Institute of Technology Agartala, Tripura–799 046 (India); Sharma, P. K.; Thakur, A.; Kulkarni, S. V.; Bora, D. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat–382 428 (India)

2014-06-15T23:59:59.000Z

45

E-Print Network 3.0 - argon radio-frequency glow Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

show that application of a radio-frequency... during the power on' (active glow) fraction of the cycle. A transition from an electron-dominated plasma... D models. The...

46

A MODULAR STEADY STATE GLOW DISCHARGE QUADRUPOLE MASS SPECTROMETER SYSTEM FOR THE AT-LINE ANALYSIS OF PLUTONIUM METAL  

SciTech Connect (OSTI)

Historically, glow discharge mass and optical spectrometric techniques have been used in industry for the characterization of processed metals, such as steels and other alloys. This technique is especially well suited for this type of product analysis because the glow discharge ionization source accommodates solid conducting samples with minimal or no sample preparation. This characteristic along with minimal matrix effect considerations makes the glow discharge source well suited for these types of applications.

R. STEINER; D. WAYNE

1998-12-01T23:59:59.000Z

47

Ambient-atmosphere glow discharge for determination of elemental concentration in solutions in a high-throughput or transient fashion  

DOE Patents [OSTI]

An ambient atmosphere glow discharge spectrometer is disclosed having a capillary, two electrodes and a means for recording the atomic emissions.

Webb, Michael R. (Somerville, MA); Hieftje, Gary M. (Bloomington, IN); Andrade, Francisco (Leeds, GB)

2011-04-19T23:59:59.000Z

48

Ocean Viruses: Tiny entities with Global Impacts ( JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)  

SciTech Connect (OSTI)

Matt Sullivan from the University of Arizona on "Ocean Viruses: Tiny Entities with Global Impacts" at the 7th Annual Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, Calif.

Sullivan, Matthew B [University of Arizona] [University of Arizona

2012-03-22T23:59:59.000Z

49

Ocean Viruses: Tiny entities with Global Impacts ( JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)  

ScienceCinema (OSTI)

Matt Sullivan from the University of Arizona on "Ocean Viruses: Tiny Entities with Global Impacts" at the 7th Annual Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, Calif.

Sullivan, Matthew B [University of Arizona

2013-01-15T23:59:59.000Z

50

Binary and ternary gas mixtures with temperature enhanced diffuse glow discharge characteristics for use in closing switches  

DOE Patents [OSTI]

An improvement to the gas mixture used in diffuse glow discharge closing switches is disclosed which includes binary and ternary gas mixtures which are formulated to exhibit decreasing electron attachment with increasing temperature. This increases the efficiency of the conductance of the glow discharge and further inhibits the formation of an arc. 11 figs.

Christophorou, L.G.; Hunter, S.R.

1988-06-28T23:59:59.000Z

51

Binary and ternary gas mixtures with temperature enhanced diffuse glow discharge characteristics for use in closing switches  

DOE Patents [OSTI]

An improvement to the gas mixture used in diffuse glow discharge closing switches is disclosed which includes binary and ternary gas mixtures which are formulated to exhibit decreasing electron attachment with increasing temperature. This increases the efficiency of the conductance of the glow discharge and further inhibits the formation of an arc. 11 figs.

Christophorou, L.G.; Hunter, S.R.

1990-06-26T23:59:59.000Z

52

Mechanism behind self-sustained oscillations in direct current glow discharges and in dusty plasmas  

E-Print Network [OSTI]

An alternative explanation to the mechanism behind self-sustained oscillations of ions in direct current (DC) glow discharges is provided. Such description is distinguished from the one provided by fluid models, where oscillations are attributed to positive feedback mechanism associated with photoionization of particles and photoemission of electrons from the cathode. Here, oscillations arise as consequence of interaction between an ion and surface charges induced by it at the bounding electrodes. Such mechanism provides an elegant explanation to why self-sustained oscillations occur only in the negative resistance region of the voltage-current characteristic curve in DC glow discharges. It is found that oscillation frequencies increase with ion's surface charge density, but at the rate which is significantly slower than it does with electric field. The presented mechanism also describes the self-sustained oscillations of ions in dusty plasmas, demonstrating that oscillations in dusty plasmas and DC glow disc...

Cho, Sung Nae

2013-01-01T23:59:59.000Z

53

Long range temporal correlation in the chaotic oscillations of a dc glow discharge plasma  

SciTech Connect (OSTI)

Long range temporal correlations in the fluctuations of the plasma floating potentials (measured using a Langmuir probe) are investigated in a dc glow discharge plasma. Keeping the neutral pressure constant, the discharge voltage was varied and at the formation of the plasma, quasi periodic oscillations were excited and on further increase of the discharge voltage they became chaotic (irregular) beyond a threshold voltage. We compared the Lyapunov exponent with the Hurst exponent obtained from R/S statistics which showed an opposite behaviour at the transition point. These results are perhaps new since we have not come across such comparative analysis for chaotic oscillations in a glow discharge plasma before.

Lahiri, S. [Dinabandhu Mahavidyalaya, Bongaon, North 24 Parganas, Kolkata 743235 (India); Roychowdhury, D. [Techno India, EM4/1 Sector V, Salt Lake, Kolkata 700091 (India); Sekar Iyengar, A. N. [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India)

2012-08-15T23:59:59.000Z

54

Dynamics of an excitable glow-discharge plasma under external forcing  

SciTech Connect (OSTI)

Glow discharge plasma in the excitable regime shows rich dynamical behavior under external forcing. By perturbing the plasma with a subthreshold sawtooth periodic signal, we obtained small subthreshold oscillations that showed resonance with the perturbation frequency. The resonance phenomenon can be useful to estimate characteristic of an excitable system. However, for suprathreshold perturbation, frequency entrainment was observed. In this case, the system showed harmonic frequency entrainment for the perturbation frequencies greater than the characteristic frequency of the system and the excitable behavior for the perturbation frequencies well below the characteristic frequency. The experiments were performed in a glow-discharge plasma where excitability was achieved at a suitable discharge voltage and gas pressure.

Nurujjaman, Md.; Iyengar, A. N. Sekar [Centre for Applicable Mathematics, Tata Institute of Fundamental Research, Sharada Nagar, Chikkabommasandra, Bangalore 560065 (India) and Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

2010-11-15T23:59:59.000Z

55

Binary and ternary gas mixtures for use in glow discharge closing switches  

DOE Patents [OSTI]

Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue if the combines physio-electric properties of the mixture components. 9 figs.

Hunter, S.R.; Christophorou, L.G.

1988-04-27T23:59:59.000Z

56

Spectroscopic diagnostics of the plasma in the cathode region of a nitrogen glow discharge  

E-Print Network [OSTI]

323 Spectroscopic diagnostics of the plasma in the cathode region of a nitrogen glow discharge A of the characteristic quantities of the plasma, the diagnostics must be made in situ by non-intrusive methods that offer. Margulis and J. Jolly Laboratoire de Physique des Gaz et des Plasmas, Bâtiment 212, Université de Paris

Paris-Sud XI, Université de

57

High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry  

SciTech Connect (OSTI)

The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

McLuckey, S.A.; Goeringer, D.E.; Asano, K.G. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1996-02-01T23:59:59.000Z

58

The powerful high-voltage glow discharge electron gun and power unit on its base  

SciTech Connect (OSTI)

The technical and operational characteristics and features of powerful electron gun with cold cathodes on the basis of high-voltage glow discharge (HGD) are submitted. The systems, ensuring their work are described. Some results of operation and applications of these non-traditional electron guns are presented.

Chernov, V.A. [All-Russian Electrotechnical Institute, Moscow (Russian Federation)

1994-12-31T23:59:59.000Z

59

Role of trace impurities in large-volume noble gas atmospheric-pressure glow discharges  

E-Print Network [OSTI]

Role of trace impurities in large-volume noble gas atmospheric-pressure glow discharges Xiaohui. Large-volume APG discharges find numerous applications in processing of material surfaces,1 ozone-purity helium is presented, and the role of trace impurities in such noble gas plasmas is established. Trace

Raja, Laxminarayan L.

60

Bacteria with tiny projections can make efficient fuel cells September 7th, 2009 -3:52 pm ICT by ANI -  

E-Print Network [OSTI]

the University of Massachusetts, US. The researchers isolated a strain of Geobacter sulfurreducens, which biofilm on the anode surface, which conducted electricity. The researchers found large quantities of pilin, a protein that makes the tiny fibres that conduct electricity through the sticky biofilm. "The filaments

Lovley, Derek

Note: This page contains sample records for the topic "tiny crystals glow" from the National Library of EnergyBeta (NLEBeta).
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61

Excessive Balmer line broadening in a plane cathode abnormal glow discharge in hydrogen  

SciTech Connect (OSTI)

Results of a Doppler spectroscopy study of the hydrogen Balmer alpha line in an abnormal glow discharge operated in pure hydrogen are reported. Measurements of line shapes are performed side-on to the discharge axis in a low electric field region of negative glow. The excessive Balmer alpha broadening is detected and its presence and linewidth is related to the collisions of fast hydrogen atoms with molecular hydrogen. The collision model enabled also an estimation of effective cross section data from the Balmer alpha axial intensity decay curves. Large excessive Balmer alpha line broadening in pure hydrogen and its dependence upon the direction of observation with respect to the electric field is in contradiction to the resonance transfer model, proposed byMills et al. in several publications [see, e.g., IEEE Trans. Plasma Sci. 31, 338 (2003)].

Cvetanovic, N.; Kuraica, M.M.; Konjevic, N. [Center for Science and Development of Technology, Obilicev Venac 26, Belgrade, and Faculty of Transport and Traffic Engineering, University of Belgrade, V. Stepe 305, Belgrade (Serbia and Montenegro); Faculty of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade, and Center for Science and Development of Technology, Obilicev Venac 26, Belgrade (Serbia and Montenegro); Faculty of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade (Serbia and Montenegro)

2005-02-01T23:59:59.000Z

62

Investigation of complexity dynamics of inverse and normal homoclinic bifurcation in a glow discharge plasma  

SciTech Connect (OSTI)

Order-chaos-order was observed in the relaxation oscillations of a glow discharge plasma with variation in the discharge voltage. The first transition exhibits an inverse homoclinic bifurcation followed by a homoclinic bifurcation in the second transition. For the two regimes of observations, a detailed analysis of correlation dimension, Lyapunov exponent, and Renyi entropy was carried out to explore the complex dynamics of the system.

Saha, Debajyoti, E-mail: debajyoti.saha@saha.ac.in; Kumar Shaw, Pankaj; Janaki, M. S.; Sekar Iyengar, A. N.; Ghosh, Sabuj; Mitra, Vramori, E-mail: vramorimitra@yahoo.com; Michael Wharton, Alpha [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)] [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

2014-03-15T23:59:59.000Z

63

Glow discharge cleaning and vacuum deposition of copper on 6061-T6 aluminum  

SciTech Connect (OSTI)

Prior to plating electroless nickel onto a part made of 6061-T6 aluminum, several aqueous pretreatment steps are required which end with the deposition of a thin copper layer covering the part. In an effort to minimize the quantity and type of wastes generated during this pretreatment process, vacuum deposition methods are under evaluation as an alternative. Six vacuum cleaning/copper deposition experiments have been conducted on 6061-T6 aluminum coupons. The coupons were glow discharge cleaned at 1500, 2000 and 2500 volts and a copper coating was either sputtered deposited or ion plated onto the aluminum substrate. The results showed that the adhesive strength of the copper coating was greatest for those coupons cleaned at 2500 volts and ion plated. Glow discharge cleaning was greatest for those coupons cleaned at 2500 volts and ion plated. Glow discharge cleaning at 1500 and 2000 volts resulted in copper films that were porous while those cleaned at 2500 volts were not. The results further showed that ion plated copper films of appropriate thickness can be produced while the aluminum alloy is precipitation hardened. 3 refs., 9 figs., 3 tabs.

Vasofsky, R.W.; Corbett, W.D. Jr.

1991-02-25T23:59:59.000Z

64

Mechanism behind self-sustained oscillations in direct current glow discharges and dusty plasmas  

SciTech Connect (OSTI)

An alternative explanation to the mechanism behind self-sustained oscillations of ions in direct current (DC) glow discharges is provided. Such description is distinguished from the one provided by the fluid models, where oscillations are attributed to the positive feedback mechanism associated with photoionization of particles and photoemission of electrons from the cathode. Here, oscillations arise as consequence of interaction between an ion and the surface charges induced by it at the bounding electrodes. Such mechanism provides an elegant explanation to why self-sustained oscillations occur only in the negative resistance region of the voltage-current characteristic curve in the DC glow discharges. Furthermore, this alternative description provides an elegant explanation to the formation of plasma fireballs in the laboratory plasma. It has been found that oscillation frequencies increase with ion's surface charge density, but at the rate which is significantly slower than it does with the electric field. The presented mechanism also describes self-sustained oscillations of ions in dusty plasmas, which demonstrates that self-sustained oscillations in dusty plasmas and DC glow discharges involve common physical processes.

Cho, Sung Nae [Devices R and D Center, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Mt. 14-1 Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea, Republic of)

2013-04-15T23:59:59.000Z

65

External magnetic field influence on H{sub {alpha}} line in abnormal glow discharge  

SciTech Connect (OSTI)

Influence of the external axial magnetic field on the hydrogen H{sub {alpha}} line profiles in an abnormal glow discharge has been studied. It has been found that the applied magnetic field predominantly increases the intensity of central component of the characteristic excessively broadened H{sub {alpha}} profile. Magnetic filed causes helical motion of electrons along the electric field lines and prolongs their trajectories increasing the number of collisions with matrix gas. This explains the increase of the central component of H{sub {alpha}} profile and can be regarded as an experimental proof for the main contribution of electron excitation to that part of the profile.

Obradovic, B.M.; Dojcinovic, I.P.; Kuraica, M.M.; Puric, J. [Faculty of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade (Serbia and Montenegro) and Center for Science and Development of Technology, Obilicev Venac 26, 11001 Belgrade (Serbia and Montenegro)

2006-04-03T23:59:59.000Z

66

Nonlocal control of electron temperature in short direct current glow discharge plasma  

SciTech Connect (OSTI)

To demonstrate controlling the electron temperature in nonlocal plasma, experiments have been performed on a short (without positive column) dc glow discharge with a cold cathode by applying different voltages to the conducting discharge wall. The experiments have been performed for low-pressure noble gas discharges. The applied voltage can modify trapping the energetic electrons emitted from the cathode sheath and arising from the atomic and molecular processes in the plasma within the device volume. This phenomenon results in the energetic electrons heating the slow plasma electrons, which consequently modifies the electron temperature. Furthermore, a numerical model of the discharge has demonstrated the electron temperature modification for the above case.

Demidov, V. I. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine”, ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A.; Stepanova, O. M. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); Kurlyandskaya, I. P. [International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine”, ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); St. Petersburg University of State Fire Service of EMERCOM RF, Murmansk Branch, Murmansk 183040 (Russian Federation)

2014-09-15T23:59:59.000Z

67

Growth of tungsten nanoparticles in direct-current argon glow discharges  

SciTech Connect (OSTI)

The growth of nanoparticles from the sputtering of a tungsten cathode in DC argon glow discharges is reported. The study was performed at fixed argon pressure and constant discharge current. The growth by successive agglomerations is evidenced. First, tungsten nanocrystallites agglomerate into primary particles, the most probable size of which being {approx}30 nm. Primary particles of this size are observed for all plasma durations and always remain the most numerous in the discharge. Primary particles quickly agglomerate to form particles with size up to {approx}150 nm. For short plasma duration, log-normal functions describe accurately the dust particle size distributions. On the contrary, for long discharge durations, a second hump appears in the distributions toward large particle sizes. In the meantime, the discharge voltage, electron density, and emission line intensities strongly evolve. Their evolutions can be divided in four separate phases and exhibit unusual distinctive features compared to earlier observations in discharges in which particles were growing. The evolution of the different parameters is explained by a competition between the surface state of the tungsten cathode and the influence of the growing nanoparticles. The differences with sputtering glow discharges and chemically active plasmas suggest that the nanoparticle growth and its influence on discharge parameters is system and material dependent.

Kishor Kumar, K.; Coueedel, L.; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moleculaires, CNRS-Aix-Marseille Universite, 13397 Marseille (France)

2013-04-15T23:59:59.000Z

68

Radio-frequency powered glow discharge device and method with high voltage interface  

DOE Patents [OSTI]

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

69

Radio-frequency powered glow discharge device and method with high voltage interface  

DOE Patents [OSTI]

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28T23:59:59.000Z

70

Influence of the transverse dimension on the structure and properties of dc glow discharges  

SciTech Connect (OSTI)

Two-dimensional (2D) simulations of a dc glow discharge with a cold cathode in argon have been performed for various radii of the discharge tube. It is shown that the loss of the charged particles to the walls can significantly affect plasma parameters as well as properties of the cathode sheath. The longitude dimensions of the negative glow and Faraday dark space depend on the transverse loss of the charge particles and are not consistently predicted with a 1D model. The common assumption that the cathode sheath can be analyzed independently of the plasma also may not be valid. The transverse inhomogeneity of the plasma leads to a change in the current density distribution over the cathode surface. The thickness of the cathode sheath can vary with radial distance from the discharge axis, even for the case of negligible radial loss of the charge particles. The 2D model results provide an analysis of the conditions of applicability of the 1D model.

Bogdanov, E. A. [St. Petersburg State University, St. Petersburg 198904 (Russian Federation); Adams, S. F. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Demidov, V. I. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A. [Department of Optics, St. Petersburg State University, St. Petersburg 198904 (Russian Federation); Williamson, J. M. [UES, Inc., 4401 Dayton-Xenia Rd., Beavercreek, Ohio 45432 (United States)

2010-10-15T23:59:59.000Z

71

Charging of dust grains in a nonequilibrium plasma of a stratified glow discharge  

SciTech Connect (OSTI)

A theoretical model is presented that describes the charging of dust grains in the positive plasma column of a stratified glow dc discharge in argon. A one-dimensional self-consistent model is used to obtain axial profiles of the electric field, as well as the electron energy distribution function along the axis of the discharge tube. Radial profiles of the electric field are determined in the ambipolar diffusion approximation. It is assumed that, in the radial direction, the electron distribution function depends only on the total electron energy. Two-dimensional distributions of the discharge plasma parameters are calculated and used to determine the potential and charge of a test dust grain at a certain point within the discharge and the electrostatic forces acting on it. It is shown that the grain charge distribution depends strongly on the nonequilibrium electron distribution function and on the nonuniform distribution of the electric field in a stratified glow discharge. A discussion is presented on the suspension of dust grains, the separation of grains by size in the discharge striations, and a possible mechanism for the onset of vortex dust motion at the edge of a dust cloud.

Sukhinin, G. I.; Fedoseev, A. V. [Russian Academy of Sciences, Kutateladze Institute of Thermophysics, Siberian Branch (Russian Federation)

2007-12-15T23:59:59.000Z

72

On the ability of various circular inspiral templates to capture inspiral gravitational waves from compact binaries having tiny orbital eccentricities  

E-Print Network [OSTI]

We probe the ability of various types of post-Newtonian(PN)-accurate circular templates to capture inspiral gravitational-wave (GW) signals from compact binaries having tiny orbital eccentricities. The GW signals are constructed by adapting the phasing formalism, available in T. Damour, A. Gopakumar, and B. R. Iyer, [Phys. Rev. D 70, 064028 (2004)], employing the orbital energy and the time-eccentricity to describe the orbital evolution. Using the fitting factor estimates, relevant for the initial LIGO, we show that circular templates, based on the adiabatic TaylorT1, complete adiabatic TaylorT1 and TaylorT4 approximants are unable to capture our GW signals from compact binaries having tiny residual orbital eccentricities. However, the 2PN-order circular inspiral templates based on the recently introduced TaylorEt approximant are found to be both effectual and faithful in capturing GWs from inspiralling compact binaries having moderate eccentricities and we provide physical explanations for our observations.

Manuel Tessmer; Achamveedu Gopakumar

2012-02-28T23:59:59.000Z

73

Cosmic Glows  

E-Print Network [OSTI]

This is the obligatory Cosmic Microwave Background review. I discuss the current status of CMB anisotropies, together with some points on the related topic of the Far-Infrared Background. We have already learned a number of important things from CMB anisotropies. Models which are in good shape have: approximately flat geometry; cold dark-matter, plus something like a cosmological constant; roughly scale invariant adiabatic fluctuations; and close to Gaussian statistics. The constraints from the CMB are beginning to be comparable to those from other cosmological measurements. With a wealth of new data coming in, it is expected that CMB anisotropies will soon provide the most stringent limits on fundamental cosmological parameters, as well as probing high energy particle physics and the Dark Ages of astrophysics. Nudge, nudge. Wink, wink. Say no more.

Douglas Scott

1999-12-02T23:59:59.000Z

74

Non-local Effects in a Stratified Glow Discharge With Dusty Particles  

SciTech Connect (OSTI)

The work is aimed to describe non-local effects in the positive column of a low pressure stratified DC glow discharge in argon with dusty particles in a vertical cylindrical discharge tube. The numerical calculations of plasma parameters in the axis of the discharge tube were performed with the help of hybrid model based on the solution of non-local Boltzmann equation for EEDF. Distributions of optical emission from striations were measured experimentally. It is shown that in a stratified positive column the EEDF is not Maxwellian and even non-monotonous. Also, the effect of displacing of optical emission distribution relative to the electric field is shown both by numerical simulation and experimental measurements.

Sukhinin, G. I. [Institute of Thermophysics SB RAS, Lavrentyev Ave., 1, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Pirogova Str., 2, Novosibirsk, 630090 (Russian Federation); Fedoseev, A. V. [Institute of Thermophysics SB RAS, Lavrentyev Ave., 1, Novosibirsk, 630090 (Russian Federation); Ramazanov, T. S.; Amangaliyeva, R. Zh.; Dosbolayev, M. K.; Jumabekov, A. N. [Institute of Experimental and Theoretical Physics, Al Farabi Kazakh National University, Tole Bi, 96a, Almaty, 050012 (Kazakhstan)

2008-09-07T23:59:59.000Z

75

A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability  

SciTech Connect (OSTI)

We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d{sub 31} coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

Wang, Qi; Wang, Junting; Lu, Qingyou, E-mail: qxl@ustc.edu.cn [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China) [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China); Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hou, Yubin [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China)] [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China)

2013-11-15T23:59:59.000Z

76

ig research into the tiny world of nanotechnology received a giant boost with the establishment of the Russell Berrie Nanotechnology Institute (RBNI) at the  

E-Print Network [OSTI]

B ig research into the tiny world of nanotechnology received a giant boost with the establishment of the Russell Berrie Nanotechnology Institute (RBNI) at the Technion. "The Technion's ranking as a world leader in nanotechnology strongly influenced our decision," said Angelica Berrie, president of the Russell Berrie

Rimon, Elon

77

Originally published in The Technology Teacher, April 2001, by the International Technology Education Association The tiny spacecraft we have sent to explore our  

E-Print Network [OSTI]

Education Association The tiny spacecraft we have sent to explore our solar system "phone home" across truck. (New ones being planned are even smaller.) Most of them use solar panels to generate electricity transmitters mounted on giant towers to broadcast their program signals in all directions, so that anyone

78

Free-radical reactions in glow and explosion of carbon monoxide-oxygen mixtures  

SciTech Connect (OSTI)

Examination of published compilations of rate coefficients of free-radical reactions yields reactions that are associated with chain branching in mixtures of CO and O/sub 2/ and small quantities of hydrogen or water vapor. The complete mechanism included diffusion of HO/sub 2/ radicals to the vessel wall and their adsorption and reaction at the surface. This mechanism is applied to the data of E.J. Buckler and R.G.W. Norrish on the branched-chain explosion of CO-O/sub 2/ mixtures containing H/sub 2/ in the order of 1 mm Hg. Substantial agreement is found between theory and experiment. Further, the mechanism is applied to experiments of Bond, Gray, and Griffiths with an H/sub 2/ content of 0.01-0.05 mm Hg. By specifying details of the adsorption and surface reaction of HO/sub 2/ on the basis of Langmuir's adsorption the phenomenon of flow is explained and the regions of slow reaction, glow, and explosion are described in accord with the experimental data. It is confirmed that the reaction between CO and O/sub 2/ requires the presence of a hydrogenous compound such as H/sub 2/, H/sub 2/O, CH/sub 4/, etc., and that ''dry'' homogenous reaction is not possible except at very high temperatures.

Von Elbe, G.; Lewis, B.

1986-02-01T23:59:59.000Z

79

Array of surface-confined glow discharges in atmospheric pressure helium: Modes and dynamics  

SciTech Connect (OSTI)

Array of atmospheric pressure surface discharges confined by a two-dimensional hexagon electrode mesh is studied for its discharge modes and temporal evolution so as to a theoretical underpinning to their growing applications in medicine, aerodynamic control, and environmental remediation. Helium plasma surface-confined by one hexagon-shaped rim electrode is shown to evolve from a Townsend mode to a normal and abnormal glow mode, and its evolution develops from the rim electrodes as six individual microdischarges merging in the middle of the hexagon mesh element. Within one hexagon element, microdischarges remain largely static with the mesh electrode being the instantaneous cathode, but move towards the hexagon center when the electrode is the instantaneous anode. On the entire array electrode surface, plasma ignition is found to beat an unspecific hexagon element and then spreads to ignite surrounding hexagon elements. The spreading of microdischarges is in the form of an expanding circle at a speed of about 3?×?10{sup 4} m/s, and their quenching starts in the location of the initial plasma ignition. Plasma modes influence how input electrical power is used to generate and accelerate electrons and as such the reaction chemistry, whereas plasma dynamics are central to understand and control plasma instabilities. The present study provides an important aspect of plasma physics of the atmospheric surface-confined discharge array and a theoretical underpinning to its future technological innovation.

Li, D.; Liu, D. X., E-mail: liudingxin@gmail.com, E-mail: mglin5g@gmail.com [Center for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi (China); Nie, Q. Y.; Li, H. P. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Chen, H. L. [Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Kong, M. G., E-mail: liudingxin@gmail.com, E-mail: mglin5g@gmail.com [Center for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi (China); Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States)

2014-05-19T23:59:59.000Z

80

Single-crystal neutron diffraction studies on Ni-based metal-pnictide superconductor BaNi2As2  

SciTech Connect (OSTI)

We report the results of single-crystal neutron diffraction studies of the superconductor BaNi{sub 2}As{sub 2}. The experiments were performed on a tiny crystal of mass 0.8 mg at several temperatures between 20 and 200 K using the Single Crystal Diffractometer, SCD, at the Los Alamos Neutron Science Center. Above 130 K, BaNi{sub 2}As{sub 2} crystallizes in the tetragonal ThCr{sub 2}Si{sub 2} structure. Our neutron diffraction data corroborate a first-order structural transition around 130 K with a relatively large hysteresis of about 10K, in agreement with observations from bulk studies. The anisotropic thermal displacement coefficients are enhanced along c-axis approaching the transition, and a splitting is observed for in-plane type reflections below the transition, which is evidence for a change in crystal structure.

Kothapalli, Karunakar [Los Alamos National Laboratory; Ronning, F [Los Alamos National Laboratory; Bauer, E D [Los Alamos National Laboratory; Schultz, A J [Los Alamos National Laboratory; Nakotte, Heinz [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Etching of UO{sub 2} in NF{sub 3} RF Plasma Glow Discharge  

SciTech Connect (OSTI)

A series of room temperature, low pressure (10.8 to 40 Pa), low power (25 to 210 W) RF plasma glow discharge experiments with UO{sub 2} were conducted to demonstrate that plasma treatment is a viable method for decontaminating UO{sub 2} from stainless steel substrates. Experiments were conducted using NF{sub 3} gas to decontaminate depleted uranium dioxide from stainless-steel substrates. Depleted UO{sub 2} samples each containing 129.4 Bq were prepared from 100 microliter solutions of uranyl nitrate hexahydrate solution. The amorphous UO{sub 2} in the samples had a relatively low density of 4.8 gm/cm{sub 3}. Counting of the depleted UO{sub 2} on the substrate following plasma immersion was performed using liquid scintillation counting with alpha/beta discrimination due to the presence of confounding beta emitting daughter products, {sup 234}Th and {sup 234}Pa. The alpha emission peak from each sample was integrated using a gaussian and first order polynomial fit to improve quantification. The uncertainties in the experimental measurement of the etched material were estimated at about {+-} 2%. Results demonstrated that UO{sub 2} can be completely removed from stainless-steel substrates after several minutes processing at under 200 W. At 180 W and 32.7 Pa gas pressure, over 99% of all UO{sub 2} in the samples was removed in just 17 minutes. The initial etch rate in the experiments ranged from 0.2 to 7.4 {micro}m/min. Etching increased with the plasma absorbed power and feed gas pressure in the range of 10.8 to 40 Pa. A different pressure effect on UO{sub 2} etching was also noted below 50 W in which etching increased up to a maximum pressure, {approximately}23 Pa, then decreased with further increases in pressure.

John M. Veilleux

1999-08-01T23:59:59.000Z

82

3/4/2014 These windmills are so tiny, you could fit 10 of them on a grain of rice | Grist http://grist.org/list/these-windmills-are-so-tiny-you-could-fit-10-of-them-on-a-grain-of-rice/ 1/2  

E-Print Network [OSTI]

, Raw Story Sarah Laskow is a reporter based in New York City who covers environment, energy: As they grow, the energy they produce increases exponentially, because physics. But two researchers at UT," Raw Story says. When a windmill is that tiny, wind comes easy -- you could just wave your hand over

Chiao, Jung-Chih

83

Reactions of tungsten-titanium alloys with decomposition products from a glow UHF discharge in a tetrafluoromethane-oxygen mixture  

SciTech Connect (OSTI)

Decomposition products from tetrafluoromethane mixed with oxygen react with WTi alloy in an HF glow discharge, the extent of reaction being dependent on the atomic fluorine concentration, temperature, and surface potential. The rates of reaction with the CF/sub 4/ products are proportional to the atomic fluorine concentrations. The effective activation energies have been determined for the atomic fluorine reacting with the alloy components in various gases. The metal removal rate increases when the specimen is negative with respect to the plasma potential, which is ascribed to the surface being bombarded by positive ions or to the electric field affecting the surface reaction rates.

Amirov, I.I.; Vinogradov, G.K.; Slovetskii, D.I.

1988-07-01T23:59:59.000Z

84

Effect of hydrogen ratio on plasma parameters of N{sub 2}-H{sub 2} gas mixture glow discharge  

SciTech Connect (OSTI)

A dc plane glow discharge in a nitrogen-hydrogen (N{sub 2}-H{sub 2}) gas mixture has been operated at discharge currents of 10 and 20 mA. The electron energy distribution function (EEDF) at different hydrogen concentrations is measured. A Maxwellian EEDF is found in the positive column region, while in both cathode fall and negative glow regions, a non-Maxwellian one is observed. Langmuir electric probes are used at different axial positions, gas pressures, and hydrogen concentrations to measure the electron temperature and plasma density. The electron temperature is found to increase with increasing H{sub 2} concentration and decrease with increasing both the axial distance from the cathode and the mixture pressure. At first, with increasing distance from the cathode, the ion density decreases, while the electron density increases; then, as the anode is further approached, they remain nearly constant. At different H{sub 2} concentrations, the electron and ion densities decrease with increasing the mixture pressure. Both the electron and ion densities slightly decrease with increasing H{sub 2} concentration.

El-Brulsy, R. A.; Abd Al-Halim, M. A.; Abu-Hashem, A. [Benha University, Physics Department, Faculty of Science (Egypt); Rashed, U. M. [Alazhar University, Physics Department, Faculty of Science (Egypt); Hassouba, M. A. [Benha University, Physics Department, Faculty of Science (Egypt)

2012-05-15T23:59:59.000Z

85

Monochromator Crystal Glitch Library  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

SSRL's Monochromator Crystal Glitch Library allows users to view glitch spectra online, list specific crystal orientations, and download PDF files of the glitch spectra. (Specialized Interface)

86

Final Report DE-FG02-00ER54583: "Physics of Atmospheric Pressure Glow Discharges" and "Nanoparticle Nucleation and Dynamics in Low-Pressure Plasmas"  

SciTech Connect (OSTI)

This project was funded over two periods of three years each, with an additional year of no-cost extension. Research in the first funding period focused on the physics of uniform atmospheric pressure glow discharges, the second funding period was devoted to the study of the dynamics of nanometer-sized particles in plasmas.

Uwe Kortshagen; Joachim Heberlein; Steven L. Girshick

2009-06-01T23:59:59.000Z

87

Mixed crystal organic scintillators  

DOE Patents [OSTI]

A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

2014-09-16T23:59:59.000Z

88

Modification of Thermal Emission via Metallic Photonic Crystals  

SciTech Connect (OSTI)

Photonic crystals are materials that are periodically structured on an optical length scale. It was previously demonstrated that the glow, or thermal emission, of tungsten photonic crystals that have a specific structure - known as the 'woodpile structure' - could be modified to reduce the amount of infrared radiation from the material. This ability has implications for improving the efficiency of thermal emission sources and for thermophotovoltaic devices. The study of this effect had been limited because the fabrication of metallic woodpile structures had previously required a complex fabrication process. In this project we pursued several approaches to simplify the fabrication of metallic photonic crystals that are useful for modification of thermal emission. First, we used the self-assembly of micrometer-scale spheres into colloidal crystals known as synthetic opals. These opals can then be infiltrated with a metal and the spheres removed to obtain a structure, known as an inverse opal, in which a three-dimensional array of bubbles is embedded in a film. Second, we used direct laser writing, in which the focus of an infrared laser is moved through a thin film of photoresist to form lines by multiphoton polymerization. Proper layering of such lines can lead to a scaffold with the woodpile structure, which can be coated with a refractory metal. Third, we explored a completely new approach to modified thermal emission - thin metal foils that contain a simple periodic surface pattern, as shown in Fig. 1. When such a foil is heated, surface plasmons are excited that propagate along the metal interface. If these waves strike the pattern, they can be converted into thermal emission with specific properties.

Norris, David J.; Stein, Andreas; George, Steven M.

2012-07-30T23:59:59.000Z

89

CRYSTALLIZATION IN MULTICOMPONENT GLASSES  

SciTech Connect (OSTI)

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

KRUGER AA; HRMA PR

2009-10-08T23:59:59.000Z

90

Apparatus for mounting crystal  

DOE Patents [OSTI]

A thickness monitor useful in deposition or etching reactor systems comprising a crystal-controlled oscillator in which the crystal is deposited or etched to change the frequency of the oscillator. The crystal rests within a thermally conductive metallic housing and arranged to be temperature controlled. Electrode contacts are made to the surface primarily by gravity force such that the crystal is substantially free of stress otherwise induced by high temperature.

Longeway, Paul A. (East Windsor, NJ)

1985-01-01T23:59:59.000Z

91

Photonic crystal light source  

DOE Patents [OSTI]

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

2004-07-27T23:59:59.000Z

92

3/3/2014 Big ideas for tinywindmills at UTA | RenewablesBiz http://www.renewablesbiz.com/article/14/03/big-ideas-tiny-windmills-uta 1/3  

E-Print Network [OSTI]

, renewable energy dwarfed by big utility ET Solar Builds Large Scale Solar Power Projects in UK Big ideas Energy Central E-Newsletters Recent News/Commentary Three Firms Win Solar Plant Tenders In Va. politics for tiny windmills at UTA DTE Energy selects SolarCurrents projects more news News Insights #12

Chiao, Jung-Chih

93

Experimental evidence of intermittent chaos in a glow discharge plasma without external forcing and its numerical modelling  

SciTech Connect (OSTI)

Intermittent chaos was observed in a glow discharge plasma as the system evolved from regular type of relaxation oscillations (of larger amplitude) to an irregular type of oscillations (of smaller amplitude) as the discharge voltage was increased. Floating potential fluctuations were analyzed by different statistical and spectral methods. Features like a gradual change in the normal variance of the interpeak time intervals, a dip in the skewness, and a hump in the kurtosis with variation in the control parameter have been seen, which are strongly indicative of intermittent behavior in the system. Detailed analysis also suggests that the intrinsic noise level in the experiment increases with the increasing discharge voltage. An attempt has been made to model the experimental observations by a second order nonlinear ordinary differential equation derived from the fluid equations for an unmagnetized plasma. Though the experiment had no external forcing, it was conjectured that the intrinsic noise in the experiment could be playing a vital role in the dynamics of the system. Hence, a constant bias and noise as forcing terms were included in the model. Results from the theoretical model are in close qualitative agreement with the experimental results.

Ghosh, S., E-mail: sabuj.ghosh@saha.ac.in; Kumar Shaw, Pankaj; Sekar Iyengar, A. N.; Janaki, M. S.; Saha, Debajyoti; Michael Wharton, Alpha [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)] [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mitra, Vramori [Purbasha Housing Estate, Kankurgachi, Kolkata 700054 (India)] [Purbasha Housing Estate, Kankurgachi, Kolkata 700054 (India)

2014-03-15T23:59:59.000Z

94

Phononic crystal devices  

DOE Patents [OSTI]

Phononic crystals that have the ability to modify and control the thermal black body phonon distribution and the phonon component of heat transport in a solid. In particular, the thermal conductivity and heat capacity can be modified by altering the phonon density of states in a phononic crystal. The present invention is directed to phononic crystal devices and materials such as radio frequency (RF) tags powered from ambient heat, dielectrics with extremely low thermal conductivity, thermoelectric materials with a higher ratio of electrical-to-thermal conductivity, materials with phononically engineered heat capacity, phononic crystal waveguides that enable accelerated cooling, and a variety of low temperature application devices.

El-Kady, Ihab F. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2012-01-10T23:59:59.000Z

95

Liquid Crystal Optofluidics  

SciTech Connect (OSTI)

By employing anisotropic fluids and namely liquid crystals, fluid flow becomes an additional degree of freedom in designing optofluidic devices. In this paper, we demonstrate optofluidic liquid crystal devices based on the direct flow of nematic liquid crystals in microfluidic channels. Contrary to previous reports, in the present embodiment we employ the effective phase delay acquired by light travelling through flowing liquid crystal, without analysing the polarisation state of the transmitted light. With this method, we demonstrate the variation in the diffraction pattern of an array of microfluidic channels acting as a grating. We also discuss our recent activities in integrating mechanical oscillators for on-chip peristaltic pumping.

Vasdekis, Andreas E.; Cuennet, J. G.; Psaltis, D.

2012-10-11T23:59:59.000Z

96

Channeling through Bent Crystals  

SciTech Connect (OSTI)

Bent crystals have demonstrated potential for use in beam collimation. A process called channeling is when accelerated particle beams are trapped by the nuclear potentials in the atomic planes within a crystal lattice. If the crystal is bent then the particles can follow the bending angle of the crystal. There are several different effects that are observed when particles travel through a bent crystal including dechanneling, volume capture, volume reflection and channeling. With a crystal placed at the edge of a particle beam, part of the fringe of the beam can be deflected away towards a detector or beam dump, thus helping collimate the beam. There is currently FORTRAN code by Igor Yazynin that has been used to model the passage of particles through a bent crystal. Using this code, the effects mentioned were explored for beam energy that would be seen at the Facility for Advanced Accelerator Experimental Tests (FACET) at a range of crystal orientations with respect to the incoming beam. After propagating 5 meters in vacuum space past the crystal the channeled particles were observed to separate from most of the beam with some noise due to dechanneled particles. Progressively smaller bending radii, with corresponding shorter crystal lengths, were compared and it was seen that multiple scattering decreases with the length of the crystal therefore allowing for cleaner detection of the channeled particles. The input beam was then modified and only a portion of the beam sent through the crystal. With the majority of the beam not affected by the crystal, most particles were not deflected and after propagation the channeled particles were seen to be deflected approximately 5mm. After a portion of the beam travels through the crystal, the entire beam was then sent through a quadrupole magnet, which increased the separation of the channeled particles from the remainder of the beam to a distance of around 20mm. A different code, which was developed at SLAC, was used to create an angular profile plot which was compared to what was produced by Yazynin's code for a beam with no multiple scattering. The results were comparable, with volume reflection and channeling effects observed and the range of crystal orientations at which volume reflection is seen was about 1 mrad in both simulations.

Mack, Stephanie; /Ottawa U. /SLAC

2012-09-07T23:59:59.000Z

97

Raman scattering in crystals  

SciTech Connect (OSTI)

A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

Edwards, D.F.

1988-09-30T23:59:59.000Z

98

PERIODIC GLOW DISCHARGE REPORT  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratorySpeedingOptimizingTools Software and Tools Chos Chos isPDSFGLOW

99

Frequency doubling crystals  

DOE Patents [OSTI]

A systematic approach to the production of frequency conversion crystals is described in which a chiral molecule has attached to it a "harmonic generating unit" which contributes to the noncentrosymmetry of the molecule. Certain preferred embodiments of such harmonic generating units include carboxylate, guanadyly and imidazolyl units. Certain preferred crystals include L-arginine fluoride, deuterated L-arginine fluoride, L-arginine chloride monohydrate, L-arginine acetate, dithallium tartrate, ammonium N-acetyl valine, N-acetyl tyrosine and N-acetyl hydroxyproline. Chemical modifications of the chiral molecule, such as deuteration, halogenation and controlled counterion substitution are available to adapt the dispersive properties of a crystal in a particular wavelength region.

Wang, Francis (Danville, CA); Velsko, Stephan P. (Livermore, CA)

1989-01-01T23:59:59.000Z

100

Demazure Crystals, Kirillov-Reshetikhin Crystals, and the Energy Function  

E-Print Network [OSTI]

It has previously been shown that, at least for non-exceptional Kac-Moody Lie algebras, there is a close connection between Demazure crystals and tensor products of Kirillov-Reshetikhin crystals. In particular, certain ...

Schilling, Anne

Note: This page contains sample records for the topic "tiny crystals glow" 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

Pulsed CO{sub 2} laser with an X-ray preioniser based on a high-voltage low-pressure glow discharge  

SciTech Connect (OSTI)

An X-ray preioniser with an electron beam energy density of 0.1 J cm{sup -2} based on a high-voltage (20 - 40 kV) low-pressure glow discharge is developed for repetitively pulsed gas lasers. The electron concentration in the CO{sub 2} - N{sub 2} - He mixture as a function of the voltage across the preioniser is calculated for titanium and other foils. The preioniser can be operated both in a single-pulse regime and at pulse repetition rates ranging up to hundreds of Hertz. A specific energy yield of 51 J L{sup -1} is achieved in the X-ray preionised pulsed CO{sub 2} atmospheric-pressure laser. This preioniser was shown to be efficient for other active media (CO and excimer lasers), which opens up new opportunities for the development of repetitively pulsed gas lasers. (lasers)

Oreshkin, V F; Seregin, Aleksandr M; Sinaiskii, V V; Shchetinkina, T A ['Astrofizika' Research and Production Association (Russian Federation); Sorokin, A R [Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

2003-12-31T23:59:59.000Z

102

Silicon crystal growing by oscillating crucible technique  

DOE Patents [OSTI]

A process for growing silicon crystals from a molten melt comprising oscillating the container during crystal growth is disclosed.

Schwuttke, G.H.; Kim, K.M.; Smetana, P.

1983-08-03T23:59:59.000Z

103

Liquid Sampling-Atmospheric Pressure Glow Discharge (LS-APGD) Ionization Source for Elemental Mass Spectrometry: Preliminary Parametric Evaluation and Figures of Merit  

SciTech Connect (OSTI)

A new, low power ionization source for the elemental analysis of aqueous solutions has recently been described. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) source operates at relatively low currents (<20 mA) and solution flow rates (<50 ?L min-1), yielding a relatively simple alternative for atomic mass spectrometry applications. The LS-APGD has been interfaced to what is otherwise an organic, LC-MS mass analyzer, the Thermo Scientific Exactive Orbitrap without any modifications; other than removing the electrospray ionization (ESI) source supplied with that instrument. A glow discharge is initiated between the surface of the test solution exiting a glass capillary and a metallic counter electrode mounted at a 90° angle and separated by a distance of ~5 mm. As with any plasma-based ionization source, there are key discharge operation and ion sampling parameters that affect the intensity and composition of the derived mass spectra; including signal-to-background ratios. We describe here a preliminary parametric evaluation of the roles of discharge current, solution flow rate, argon sheath gas flow rate, and ion sampling distance as they apply on this mass analyzer system. A cursive evaluation of potential matrix effects due to the presence of easily ionized elements (EIEs) indicate that sodium concentrations of up to 500 ?g mL-1 generally cause suppressions of less than 50%, dependant upon the analyte species. Based on the results of this series of studies, preliminary limits of detection (LOD) have been established through the generation of calibration functions. Whilst solution-based concentrations LOD levels of 0.02 – 2 ?g mL-1 3 are not impressive on the surface, the fact that they are determined via discrete 5 ?L injections leads to mass-based detection limits at picogram to singlenanogram levels. The overhead costs associated with source operation (10 W d.c. power, solution flow rates of <50 ?L min-1, and gas flow rates <10 mL min-1) are very attractive. While further optimization in the source design is suggested here, it is believed that the LS-APGD ion source may present a practical alternative to inductively-coupled plasma (ICP) sources typically employed in elemental mass spectrometry.

Quarles, C. Derrick; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Marcus, R. Kenneth

2012-01-01T23:59:59.000Z

104

Florida Nuclear Profile - Crystal River  

U.S. Energy Information Administration (EIA) Indexed Site

Crystal River1" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

105

Crystal face temperature determination means  

DOE Patents [OSTI]

An optically transparent furnace having a detection apparatus with a pedestal enclosed in an evacuated ampule for growing a crystal thereon is disclosed. Temperature differential is provided by a source heater, a base heater and a cold finger such that material migrates from a polycrystalline source material to grow the crystal. A quartz halogen lamp projects a collimated beam onto the crystal and a reflected beam is analyzed by a double monochromator and photomultiplier detection spectrometer and the detected peak position in the reflected energy spectrum of the reflected beam is interpreted to determine surface temperature of the crystal. 3 figs.

Nason, D.O.; Burger, A.

1994-11-22T23:59:59.000Z

106

Lamella settler crystallizer  

DOE Patents [OSTI]

A crystallizer is described which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as well as in other electrochemical systems requiring separation for phases of different densities. 3 figs.

Maimoni, A.

1990-12-18T23:59:59.000Z

107

Lamella settler crystallizer  

DOE Patents [OSTI]

A crystallizer which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as well as in other electrochemical systems requiring separation for phases of different densities.

Maimoni, Arturo (Orinda, CA)

1990-01-01T23:59:59.000Z

108

Frequency mixing crystal  

DOE Patents [OSTI]

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, Christopher A. (Livermore, CA); Davis, Laura E. (Manteca, CA); Webb, Mark (Salida, CA)

1992-01-01T23:59:59.000Z

109

PHOTOCATALYTIC AND PHOTOELECTROCHEMICAL HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS  

E-Print Network [OSTI]

HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS F.HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS

Wagner, F.T.

2012-01-01T23:59:59.000Z

110

X-Ray Crystallography What do you need? A crystal. But not just any crystal a well ordered crystal  

E-Print Network [OSTI]

X-Ray Crystallography What do you need? A crystal. But not just any crystal­ a well ordered crystal that will diffract x-rays strongly. A crystal handedness. This reduces number to 6- 12. #12;#12;Generally X-ray beam

Cavanagh, John

111

Scale Effects in Crystal Plasticity  

E-Print Network [OSTI]

The goal of this research work is to further the understanding of crystal plasticity, particularly at reduced structural and material length scales. Fundamental understanding of plasticity is central to various challenges facing design...

Padubidri Janardhanachar, Guruprasad

2010-07-14T23:59:59.000Z

112

Crystal-Like geometric modeling  

E-Print Network [OSTI]

faces, symmetry, and fractal geometry. The techniques have also been implemented in software, as a proof of concept. They are used in an interactive geometric modeling system, in which users can use these techniques to create crystal-like shapes...

Landreneau, Eric Benjamin

2006-08-16T23:59:59.000Z

113

Minimizing radiation damage in nonlinear optical crystals  

DOE Patents [OSTI]

Methods are disclosed for minimizing laser induced damage to nonlinear crystals, such as KTP crystals, involving various means for electrically grounding the crystals in order to diffuse electrical discharges within the crystals caused by the incident laser beam. In certain embodiments, electrically conductive material is deposited onto or into surfaces of the nonlinear crystals and the electrically conductive surfaces are connected to an electrical ground. To minimize electrical discharges on crystal surfaces that are not covered by the grounded electrically conductive material, a vacuum may be created around the nonlinear crystal.

Cooke, D. Wayne (Santa Fe, NM); Bennett, Bryan L. (Los Alamos, NM); Cockroft, Nigel J. (Santa Fe, NM)

1998-01-01T23:59:59.000Z

114

Minimizing radiation damage in nonlinear optical crystals  

DOE Patents [OSTI]

Methods are disclosed for minimizing laser induced damage to nonlinear crystals, such as KTP crystals, involving various means for electrically grounding the crystals in order to diffuse electrical discharges within the crystals caused by the incident laser beam. In certain embodiments, electrically conductive material is deposited onto or into surfaces of the nonlinear crystals and the electrically conductive surfaces are connected to an electrical ground. To minimize electrical discharges on crystal surfaces that are not covered by the grounded electrically conductive material, a vacuum may be created around the nonlinear crystal. 5 figs.

Cooke, D.W.; Bennett, B.L.; Cockroft, N.J.

1998-09-08T23:59:59.000Z

115

Adaptive Liquid Crystal Windows  

SciTech Connect (OSTI)

Energy consumption by private and commercial sectors in the U.S. has steadily grown over the last decade. The uncertainty in future availability of imported oil, on which the energy consumption relies strongly, resulted in a dramatic increase in the cost of energy. About 20% of this consumption are used to heat and cool houses and commercial buildings. To reduce dependence on the foreign oil and cut down emission of greenhouse gases, it is necessary to eliminate losses and reduce total energy consumption by buildings. To achieve this goal it is necessary to redefine the role of the conventional windows. At a minimum, windows should stop being a source for energy loss. Ideally, windows should become a source of energy, providing net gain to reduce energy used to heat and cool homes. It is possible to have a net energy gain from a window if its light transmission can be dynamically altered, ideally electronically without the need of operator assistance, providing optimal control of the solar gain that varies with season and climate in the U.S. In addition, the window must not require power from the building for operation. Resolution of this problem is a societal challenge and of national interest and will have a broad global impact. For this purpose, the year-round, allclimate window solution to provide an electronically variable solar heat gain coefficient (SHGC) with a wide dynamic range is needed. AlphaMicron, Inc. (AMI) developed and manufactured 1ft × 1ft prototype panels for the world’s first auto-adjusting Adaptive Liquid Crystal Windows (ALCWs) that can operate from sunlight without the need for external power source and demonstrate an electronically adjustable SHGC. This novel windows are based on AlphaMicron’s patented e-Tint® technology, a guesthost liquid crystal system implemented on flexible, optically clear plastic films. This technology is suitable both for OEM and aftermarket (retro-fitting) lamination to new and existing windows. Low level of power consumption by ALCWs allows for on-board power electronics for automatic matching of transmission through windows to varying climate conditions without drawing the power from the power grid. ALCWs are capable of transmitting more sunlight in winters to assist in heating and less sunlight in summers to minimize overheating. As such, they can change the window from being a source of energy loss to a source of energy gain. In addition, the scalable AMI’s roll-to-roll process, proved by making 1ft × 1ftALCW prototype panels, allows for cost-effective production of large-scale window panels along with capability to change easily their color and shape. In addition to architectural glazing in houses and commercial buildings, ALCWs can be used in other applications where control of sunlight is needed, such as green houses, used by commercial produce growers and botanical gardens, cars, aircrafts, etc.

Taheri, Bahman; Bodnar, Volodymyr

2011-12-31T23:59:59.000Z

116

Calibrating Curved Crystals Used for Plasma Spectroscopy  

SciTech Connect (OSTI)

The throughput and resolving power of an X-ray spectrometer that uses a curved crystal as the diffraction element is determined primarily by the crystal X-ray reflectivity properties. This poster presents a measurement technique for these crystal parameters using a simple diode source to produce a narrow spectral band. The results from measurements on concave elliptical polyethylene terephthalate (PET) crystals and convex potassium acid phthalate (KAP) crystals show large variations in the key parameters compared to those from the flat crystal.

Haugh, M. J., Jacoby, K. D., Ross, P. W., Rochau, G. Wu, M., Regan, S. P., Barrios, M. A.

2012-10-29T23:59:59.000Z

117

Precision Crystal Calorimeters in High Energy Physics  

ScienceCinema (OSTI)

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal?s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

Ren-Yuan Zhu

2010-01-08T23:59:59.000Z

118

Manufacturing method of photonic crystal  

DOE Patents [OSTI]

A manufacturing method of a photonic crystal is provided. In the method, a high-refractive-index material is conformally deposited on an exposed portion of a periodic template composed of a low-refractive-index material by an atomic layer deposition process so that a difference in refractive indices or dielectric constants between the template and adjacent air becomes greater, which makes it possible to form a three-dimensional photonic crystal having a superior photonic bandgap. Herein, the three-dimensional structure may be prepared by a layer-by-layer method.

Park, In Sung; Lee, Tae Ho; Ahn, Jin Ho; Biswas, Rana; Constant, Kristen P.; Ho, Kai-Ming; Lee, Jae-Hwang

2013-01-29T23:59:59.000Z

119

Photon tunnelling microscopy of polyethylene single crystals  

E-Print Network [OSTI]

Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

Srinivasarao, Mohan

120

Nanopatterned anchoring layers for liquid crystals  

E-Print Network [OSTI]

This thesis describes the theory and fabrication of inhomogeneous Liquid Crystal anchoring layers. While chemical anchoring techniques have proved useful for many applications, especially Liquid Crystal Displays, they have ...

Gear, Christopher S. (Christopher Stanwood)

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Shearing Flows in Liquid Crystal Models  

E-Print Network [OSTI]

The liquid crystal phase is a phase of matter between the solid and liquid phase whose flow is characterized by a velocity field and a director field which describes locally the orientation of the liquid crystal. In this ...

Dorn, Timothy

2012-05-31T23:59:59.000Z

122

Ames Lab 101: Growing Crystals in Space  

ScienceCinema (OSTI)

Rohit Trivedi, distinguished professor of materials science and engineering, discusses his research with NASA to grow crystals in space.

Trivedi, Rohit

2012-08-29T23:59:59.000Z

123

Laser Assisted Crystallization of Ferromagnetic Amorphous Ribbons...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ferromagnetic Amorphous Ribbons: A Multimodal Characterization and Thermal Model Study. Laser Assisted Crystallization of Ferromagnetic Amorphous Ribbons: A Multimodal...

124

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals  

E-Print Network [OSTI]

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals A. T. KWAN, M. YU. EFREMOV, E. A-film differential scanning calorimetry to investigate the melt- ing of isolated polyethylene single crystals of lamellar single crystals of polyethylene (PE). We obtain thickness, diffraction, and calorimetry data

Allen, Leslie H.

125

Robotic CCD microscope for enhanced crystal recognition  

DOE Patents [OSTI]

A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

Segelke, Brent W. (San Ramon, CA); Toppani, Dominique (Livermore, CA)

2007-11-06T23:59:59.000Z

126

Transition from Irradiation-Induced Amorphization to Crystallization...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

from Irradiation-Induced Amorphization to Crystallization in Nanocrystalline Silicon Carbide. Transition from Irradiation-Induced Amorphization to Crystallization in...

127

Chemistry in Motion: Tiny Synthetic Motors  

E-Print Network [OSTI]

In this Account, we describe how synthetic motors that operate by self-diffusiophoresis make use of a self-generated concentration gradient to drive motor motion. A description of propulsion by self-diffusiophoresis is presented for Janus particle motors comprising catalytic and noncatalytic faces. The properties of the dynamics of chemically powered motors are illustrated by presenting the results of particle-based simulations of sphere-dimer motors constructed from linked catalytic and noncatalytic spheres. The geometries of both Janus and sphere-dimer motors with asymmetric catalytic activity support the formation of concentration gradients around the motors. Because directed motion can occur only when the system is not in equilibrium, the nature of the environment and the role it plays in motor dynamics are described. Rotational Brownian motion also acts to limit directed motion, and it has especially strong effects for very small motors. We address the following question: how small can motors be and still exhibit effects due to propulsion, even if only to enhance diffusion? Synthetic motors have the potential to transform the manner in which chemical dynamical processes are carried out for a wide range of applications.

Peter H. Colberg; Shang Yik Reigh; Bryan Robertson; Raymond Kapral

2014-11-03T23:59:59.000Z

128

Abstract crystals Department of Mathematics  

E-Print Network [OSTI]

is a normal crystal define a bijection si : B B by sib = ~f wti(b) i b, if wti(b) 0, ~e -wti(b) i b, if wti, b2 B2} with wti(b1 b2) = wti(b1) + wti(b2), i(b1 b2) = max{i(b1), i(b2) - wt(b1), i }, i(b1 b2

Ram, Arun

129

Insights into the crystal chemistry of Earth materials rendered by electron density distributions: Pauling's rules revisited  

SciTech Connect (OSTI)

Pauling's first two rules are examined in terms of the accumulation of the electron density between bonded pairs of atoms for a relatively large number of oxide and silicate crystals and siloxane molecules. The distribution of the electron density shows that the radius of the oxygen atom is not fixed, but that it actually decreases systematically from ~1.40 Å to ~ 0.65 Å as the polarizing power and the electronegativity of the bonded metal atoms increase and the distribution of the O atom is progressively polarized and contracted along the bond vectors by the impact of the bonded interactions. The contractions result in an aspherical oxygen atom that displays as many different bonded “radii” as it has bonded interactions. The bonded radii for the metal atoms match the Shannon and Prewitt ionic radii for the more electropositive atoms like potassium and sodium, but they are systematically larger for the more electronegative atoms like aluminum, silicon and phosphorous. Pauling's first rule is based on the assumption that the radius of the oxide anion is fixed and that the radii of the cations are such that radius sum of the spherical oxide anion and a cation necessarily equals the separation between the cation-anion bonded pair with the coordination number of the cation being determined by the ratio of the radii of the cation and anion. In the case of the bonded radii, the sum of the bonded radii for the metal atoms and the oxide anion necessarily equals the bond lengths by virtue of the way that the bonded radii were determined in the partitioning of the electron density along the bond path into metal and O atom parts. But, the radius ratio for the O and M atoms is an unsatisfactory rule for determining the coordination number of the metal atom inasmuch as a bonded O atom is not, in general, spherical, and its size varies substantially along its bonded directions. But by counting the number of bond paths that radiate from a bonded atom, the coordination number of the atom is determined uniquely independent of the asphericity and sizes of the atom. A power law connection established between the bond lengths and bond strengths for crystals and molecules is mirrored by a comparable power law connection between bond length and the accumulation of the electron density between bonded pairs of atoms, a connection that is consistent with Pauling's electroneutrality postulate that the charges of the atoms in an oxide are negligibly small. The connection indicates that a one-to-one correspondence exists between the accumulation between a pair of bonded atoms and the Pauling bond strength for M-O bonded interaction for all atoms of the periodic table. The connection provides a common basis for understanding the success of the manifold applications that have been made with the bond valence theory model together with the modeling of crystal structures, chemical zoning, leaching and cation transport in batteries and the like. We believe that the wide spread applications of the model in mineralogy and material science owes much of its success to the direct connection between bond strength and the quantum mechanical observable, the electron density distribution. Comparable power law expressions established for the bonded interactions for both crystals and molecules support Pauling's assertion that his second rule has significance for molecules as well as for crystals. A simple expression is found that provides a one to one connection between the accumulation of the electron density between bonded M and O atoms and the Pauling bond strength for all M atoms of the periodic table with ~ 95 % of the variation of the bond strength being explained in terms of a linear dependence on the accumulated electron density. Compelling evidence is presented that supports the argument that the Si-O bonded interactions for tiny siloxane molecules and silicate crystals are chemically equivalent.

Gibbs, Gerald V.; Ross, Nancy L.; Cox, David F.; Rosso, Kevin M.

2014-05-20T23:59:59.000Z

130

Crystallization and functionality of inorganic materials  

SciTech Connect (OSTI)

In this article, we briefly summarized our recent work on the studies of crystallization and functionality of inorganic materials. On the basis of the chemical bonding theory of single crystal growth, we can quantitatively simulate Cu{sub 2}O crystallization processes in solution system. We also kinetically controlled Cu{sub 2}O crystallization process in the reduction solution route. Lithium ion battery and supercapacitor performances of some oxides such as Co{sub 3}O{sub 4} and MnO{sub 2} were shown to elucidate the important effect of crystallization on functionality of inorganic materials. This work encourages us to create novel functionalities through the study of crystallization of inorganic materials, which warrants more chances in the field of functional materials.

Xue, Dongfeng, E-mail: dongfeng@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China) [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Li, Keyan [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)] [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, Jun [Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, 411105 (China)] [Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, 411105 (China); Sun, Congting; Chen, Kunfeng [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China) [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)

2012-10-15T23:59:59.000Z

131

Flowing Liquid Crystal Simulating the Schwarzschild Metric  

E-Print Network [OSTI]

We show how to simulate the equatorial section of the Schwarzschild metric through a flowing liquid crystal in its nematic phase. Inside a liquid crystal in the nematic phase, a traveling light ray feels an effective metric, whose properties are linked to perpendicular and parallel refractive indexes, $n_o$ e $n_e$ respectively, of the rod-like molecule of the liquid crystal. As these indexes depend on the scalar order parameter of the liquid crystal, the Beris-Edwards hydrodynamic theory is used to connect the order parameter with the velocity of a liquid crystal flow at each point. This way we calculate a radial velocity profile that simulates the equatorial section of the Schwarzschild metric, in the region outside of Schwarzschild's radius, in the nematic phase of the liquid crystal. In our model, the higher flow velocity can be of the order of some meters per second.

Erms R. Pereira; Fernando Moraes

2010-11-21T23:59:59.000Z

132

Phonon manipulation with phononic crystals.  

SciTech Connect (OSTI)

In this work, we demonstrated engineered modification of propagation of thermal phonons, i.e. at THz frequencies, using phononic crystals. This work combined theoretical work at Sandia National Laboratories, the University of New Mexico, the University of Colorado Boulder, and Carnegie Mellon University; the MESA fabrication facilities at Sandia; and the microfabrication facilities at UNM to produce world-leading control of phonon propagation in silicon at frequencies up to 3 THz. These efforts culminated in a dramatic reduction in the thermal conductivity of silicon using phononic crystals by a factor of almost 30 as compared with the bulk value, and about 6 as compared with an unpatterned slab of the same thickness. This work represents a revolutionary advance in the engineering of thermoelectric materials for optimal, high-ZT performance. We have demonstrated the significant reduction of the thermal conductivity of silicon using phononic crystal structuring using MEMS-compatible fabrication techniques and in a planar platform that is amenable to integration with typical microelectronic systems. The measured reduction in thermal conductivity as compared to bulk silicon was about a factor of 20 in the cross-plane direction [26], and a factor of 6 in the in-plane direction. Since the electrical conductivity was only reduced by a corresponding factor of about 3 due to the removal of conductive material (i.e., porosity), and the Seebeck coefficient should remain constant as an intrinsic material property, this corresponds to an effective enhancement in ZT by a factor of 2. Given the number of papers in literature devoted to only a small, incremental change in ZT, the ability to boost the ZT of a material by a factor of 2 simply by reducing thermal conductivity is groundbreaking. The results in this work were obtained using silicon, a material that has benefitted from enormous interest in the microelectronics industry and that has a fairly large thermoelectric power factor. In addition, the techniques and scientific understanding developed in the research can be applied to a wide range of materials, with the caveat that the thermal conductivity of such a material be dominated by phonon, rather than electron, transport. In particular, this includes several thermoelectric materials with attractive properties at elevated temperatures (i.e., greater than room temperature), such as silicon germanium and silicon carbide. It is reasonable that phononic crystal patterning could be used for high-temperature thermoelectric devices using such materials, with applications in energy scavenging via waste-heat recovery and thermoelectric cooling for high-performance microelectronic circuits. The only part of the ZT picture missing in this work was the experimental measurement of the Seebeck coefficient of our phononic crystal devices. While a first-order approximation indicates that the Seebeck coefficient should not change significantly from that of bulk silicon, we were not able to actually verify this assumption within the timeframe of the project. Additionally, with regards to future high-temperature applications of this technology, we plan to measure the thermal conductivity reduction factor of our phononic crystals as elevated temperatures to confirm that it does not diminish, given that the nominal thermal conductivity of most semiconductors, including silicon, decreases with temperature above room temperature. We hope to have the opportunity to address these concerns and further advance the state-of-the-art of thermoelectric materials in future projects.

Kim Bongsang; Hopkins, Patrick Edward; Leseman, Zayd C.; Goettler, Drew F.; Su, Mehmet F. (University of New Mexico, Albuquerque, NM); El-Kady, Ihab Fathy; Reinke, Charles M.; Olsson, Roy H., III

2012-01-01T23:59:59.000Z

133

Crystal structure and interaction dependence of the crystal-melt interfacial free energy  

E-Print Network [OSTI]

We examine via molecular simulation the dependence of the crystal-melt interfacial free energy gamma on molecular interaction and crystal structure (fcc vs bcc) for systems interacting with inverse-power repulsive potentials, u...

Davidchack, R. L.; Laird, Brian Bostian

2005-03-01T23:59:59.000Z

134

Singular Limits in Polymer Stabilized Liquid Crystals  

E-Print Network [OSTI]

We investigate equilibrium configurations for a polymer stabilized liquid crys- tal material ... eling the cross section of the liquid crystal-polymer fiber composite.

1910-31-00T23:59:59.000Z

135

Photonic crystals for high temperature applications  

E-Print Network [OSTI]

This thesis focuses on the design, optimization, fabrication, and experimental realization of metallic photonic crystals (MPhCs) for high temperature applications, for instance thermophotovoltaic (TPV) energy conversion ...

Yeng, Yi Xiang

2014-01-01T23:59:59.000Z

136

Supramolecular chemistry and crystal engineering ASHWINI NANGIA  

E-Print Network [OSTI]

Supramolecular chemistry and crystal engineering ASHWINI NANGIA School of Chemistry, University. This article traces the evolution of supramolecular chemistry and crystal engineering starting from the early of Hyderabad, Hyderabad 500 046, India. e-mail: ashwini.nangia@gmail.com Advances in supramolecular chemistry

Joshi, Yogesh Moreshwar

137

Growth Of Oriented Crystals At Polymerized Membranes  

DOE Patents [OSTI]

The present invention relates to methods and compositions for the growth and alignment of crystals at biopolymeric films. The methods and compositions of the present invention provide means to generate a variety of dense crystalline ceramic films, with totally aligned crystals, at low temperatures and pressures, suitable for use with polymer and plastic substrates.

Charych, Deborah H. (Albany, CA), Berman, Amir (Ben-Shiva, IL)

2000-01-25T23:59:59.000Z

138

Ames Lab 101: Single Crystal Growth  

ScienceCinema (OSTI)

Ames Laboratory scientist Deborah Schlagel talks about the Lab's research in growing single crystals of various metals and alloys. The single crystal samples are vital to researchers' understanding of the characteristics of a materials and what gives these materials their particular properties.

Schlagel, Deborah

2014-06-04T23:59:59.000Z

139

Transverse acoustic actuation of Ni-Mn-Ga single crystals  

E-Print Network [OSTI]

Two methods for the transverse acoustic actuation of {110}-cut Ni-Mn-Ga single crystals are discussed. In this actuation mode, crystals are used that have the {110}- type twinning planes parallel to the base of the crystal. ...

Simon, Jesse Matthew

2007-01-01T23:59:59.000Z

140

Liquid crystal device and method thereof  

DOE Patents [OSTI]

The invention provides a liquid crystal device and method thereof. Subsequent to applying a first electrical voltage on a liquid crystal to induce a reorientation of the liquid crystal, a second electrical voltage with proper polarity is applied on the liquid crystal to assist the relaxation of the reorientation that was induced by the first electrical voltage. The "switch-off" phase of the liquid crystal can therefore be accelerated or temporally shortened, and the device can exhibit better performance such as fast response to on/off signals. The invention can be widely used LCD, LC shutter, LC lens, spatial light modulator, telecommunication device, tunable filter, beam steering device, and electrically driven LC device, among others.

Shiyanovskii, Sergij V; Gu, Mingxia; Lavrentovich, Oleg D

2012-10-23T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Crack propagation driven by crystal growth  

SciTech Connect (OSTI)

Crystals that grow in confinement may exert a force on their surroundings and thereby drive crack propagation in rocks and other materials. We describe a model of crystal growth in an idealized crack geometry in which the crystal growth and crack propagation are coupled through the stress in the surrounding bulk solid. Subcritical crack propagation takes place during a transient period, which may be very long, during which the crack velocity is limited by the kinetics of crack propagation. When the crack is sufficiently large, the crack velocity becomes limited by the kinetics of crystal growth. The duration of the subcritical regime is determined by two non-dimensional parameters, which relate the kinetics of crack propagation and crystal growth to the supersaturation of the fluid and the elastic properties of the surrounding material.

A. Royne; Paul Meaking; A. Malthe-Sorenssen; B. Jamtveit; D. K. Dysthe

2011-10-01T23:59:59.000Z

142

Corrosion of Partially Crystallized Glasses  

SciTech Connect (OSTI)

Using existing data on corrosion of partially crystallized, simulated, high-level waste glasses, coefficients were introduced to evaluate the cumulative influence of secondary effects, such as residual stresses or concentration gradients on product consistency test response. As compared to predictions based solely on residual glass composition effects, the results showed that cristobalite, eucryptite, and nepheline had a higher-than-predicted impact on glass corrosion, while the effects of baddeleyite, hematite, calcium-zirconium silicate, and zircon were close to those predicted. The effects of acmite and lithium silicate were opposite to those expected based on their compositions. The analysis revealed important limitations of the databases currently available. Better understanding of corrosion phenomena will require quantitative composition data, microscopic characterization of pristine and corroded surfaces, and long-term tests with glass coupons or monoliths.

Hrma, Pavel R.; Riley, Brian J.; Vienna, John D.

2002-05-21T23:59:59.000Z

143

antiferroelectric liquid crystals: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of phases in antiferroelectric liquid crystals Condensed Matter (arXiv) Summary: The free energy of antiferroelectric liquid crystal which takes into account polar order...

144

antiferroelectric liquid crystal: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of phases in antiferroelectric liquid crystals Condensed Matter (arXiv) Summary: The free energy of antiferroelectric liquid crystal which takes into account polar order...

145

OPTICAL AND PHYSICAL PROPERTIES OF CERAMIC CRYSTAL LASER MATERIALS.  

E-Print Network [OSTI]

??Historically ceramic crystal laser material has had disadvantages compared to single crystal laser material. However, progress has been made in the last decade and a… (more)

Simmons, Jed

2007-01-01T23:59:59.000Z

146

Microfluidic systems for continuous crystallization of small organic molecules  

E-Print Network [OSTI]

This thesis presents one of the first demonstrations of continuous crystallization in microfluidic devices, and illustrates their use for various applications related to crystallization of small organic molecules. ...

Sultana, Mahmooda

2010-01-01T23:59:59.000Z

147

Novel photonic crystal cavities and related structures.  

SciTech Connect (OSTI)

The key accomplishment of this project is to achieve a much more in-depth understanding of the thermal emission physics of metallic photonic crystal through theoretical modeling and experimental measurements. An improved transfer matrix technique was developed to enable incorporation of complex dielectric function. Together with microscopic theory describing emitter radiative and non-radiative relaxation dynamics, a non-equilibrium thermal emission model is developed. Finally, experimental methodology was developed to measure absolute emissivity of photonic crystal at high temperatures with accuracy of +/-2%. Accurate emissivity measurements allow us to validate the procedure to treat the effect of the photonic crystal substrate.

Luk, Ting Shan

2007-11-01T23:59:59.000Z

148

NMR and NQR parameters of ethanol crystal  

E-Print Network [OSTI]

Electric field gradients and chemical shielding tensors of the stable monoclinic crystal phase of ethanol are computed. The projector-augmented wave (PAW) and gauge-including projector-augmented wave (GIPAW) models in the periodic plane-wave density functional theory are used. The crystal data from X-ray measurements, as well as the structures where either all atomic, or only hydrogen atom positions are optimized in the density functional theory are analyzed. These structural models are also studied by including the semi-empirical Van der Waals correction to the density functional theory. Infrared spectra of these five crystal models are calculated.

Milinkovic, M

2012-01-01T23:59:59.000Z

149

Cold neutron scattering in imperfect deuterium crystals  

E-Print Network [OSTI]

The differential cross sections for cold neutron scattering in mosaic deuterium crystals have been calculated for various target temperatures. The theoretical results are compared with the recent experimental data for the neutron wavelengths $\\lambda\\approx$~1--9~\\AA. It is shown that the structures of observed Bragg peaks can be explained by the mosaic spread of about $3^{\\circ}$ and contributions from a~limited number of crystal orientations. Such a~crystal structure should be also taken into account in ultracold neutron upscattering due to the coherent phonon annihilation in solid deuterium.

Andrzej Adamczak

2010-12-10T23:59:59.000Z

150

Crystal growth under external electric fields  

SciTech Connect (OSTI)

This is a review article concerning the crystal growth under external electric fields that has been studied in our lab for the past 10 years. An external field is applied electrostatically either through an electrically insulating phase or a direct injection of an electric current to the solid-interface-liquid. The former changes the chemical potential of both solid and liquid and controls the phase relationship while the latter modifies the transport and partitioning of ionic solutes in the oxide melt during crystallization and changes the solute distribution in the crystal.

Uda, Satoshi; Koizumi, Haruhiko; Nozawa, Jun; Fujiwara, Kozo [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

2014-10-06T23:59:59.000Z

151

Changes in mobility of plastic crystal ethanol during its transformation into the monoclinic crystal state  

SciTech Connect (OSTI)

Transformation of deuterated ethanol from the plastic crystal phase into the monoclinic one is investigated by means of a singular setup combining simultaneously dielectric spectroscopy with neutron diffraction. We postulate that a dynamic transition from plastic crystal to supercooled liquid-like configuration through a deep reorganization of the hydrogen-bonding network must take place as a previous step of the crystallization process. Once these precursor regions are formed, subsequent crystalline nucleation and growth develop with time.

Sanz, Alejandro, E-mail: alejandro.sanz@csic.es; Nogales, Aurora; Ezquerra, Tiberio A. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain)] [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Puente-Orench, Inés [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France) [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Instituto de Ciencia de Materiales de Aragón, ICMA-CSIC, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Jiménez-Ruiz, Mónica [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)] [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)

2014-02-07T23:59:59.000Z

152

Method for solid state crystal growth  

DOE Patents [OSTI]

A novel method for high quality crystal growth of intermetallic clathrates is presented. The synthesis of high quality pure phase crystals has been complicated by the simultaneous formation of both clathrate type-I and clathrate type-II structures. It was found that selective, phase pure, single-crystal growth of type-I and type-II clathrates can be achieved by maintaining sufficient partial pressure of a chemical constituent during slow, controlled deprivation of the chemical constituent from the primary reactant. The chemical constituent is slowly removed from the primary reactant by the reaction of the chemical constituent vapor with a secondary reactant, spatially separated from the primary reactant, in a closed volume under uniaxial pressure and heat to form the single phase pure crystals.

Nolas, George S.; Beekman, Matthew K.

2013-04-09T23:59:59.000Z

153

Squeezed state generation in photonic crystal microcavities  

E-Print Network [OSTI]

Squeezed state generation in photonic crystal microcavities M. G. Banaee, Jeff F. Young Department, G. C. Aers, R. L. Williams, "Resonant scattering and second-harmonic spectroscopy of planar

Young, Jeff

154

Neutron detection with single crystal organic scintillators  

SciTech Connect (OSTI)

Detection of high-energy neutrons in the presence of gamma radiation background utilizes pulse-shape discrimination (PSD) phenomena in organics studied previously only with limited number of materials, mostly liquid scintillators and single crystal stilbene. The current paper presents the results obtained with broader varieties of luminescent organic single crystals. The studies involve experimental tools of crystal growth and material characterization in combination with the advanced computer modeling, with the final goal of better understanding the relevance between the nature of the organic materials and their PSD properties. Special consideration is given to the factors that may diminish or even completely obscure the PSD properties in scintillating crystals. Among such factors are molecular and crystallographic structures that determine exchange coupling and exciton mobility in organic materials and the impurity effect discussed on the examples of trans-stilbene, bibenzyl, 9,10-diphenylanthracene and diphenylacetylene.

Zaitseva, N; Newby, J; Hamel, S; Carman, L; Faust, M; Lordi, V; Cherepy, N; Stoeffl, W; Payne, S

2009-07-15T23:59:59.000Z

155

Photonic crystals : from theory to practice  

E-Print Network [OSTI]

In this thesis, we explore the design, computation, and analysis of photonic crystals, with a special emphasis on structures and devices that make a connection with practically realizable systems. First, we analyze the ...

Johnson, Steven G., 1973-

2001-01-01T23:59:59.000Z

156

Crystallization of carbon tetrachloride in confined geometries  

E-Print Network [OSTI]

1 Crystallization of carbon tetrachloride in confined geometries Adil Meziane1 , Jean-Pierre E 40 71 08 #12;2 Abstract The thermal behaviour of carbon tetrachloride confined in silica gels

Paris-Sud XI, Université de

157

Electrically driven photonic crystal nanocavity devices  

E-Print Network [OSTI]

Interest in photonic crystal nanocavities is fueled by advances in device performance, particularly in the development of low-threshold laser sources. Effective electrical control of high performance photonic crystal lasers has thus far remained elusive due to the complexities associated with current injection into cavities. A fabrication procedure for electrically pumping photonic crystal membrane devices using a lateral p-i-n junction has been developed and is described in this work. We have demonstrated electrically pumped lasing in our junctions with a threshold of 181 nA at 50K - the lowest threshold ever demonstrated in an electrically pumped laser. At room temperature we find that our devices behave as single-mode light-emitting diodes (LEDs), which when directly modulated, have an ultrafast electrical response up to 10 GHz corresponding to less than 1 fJ/bit energy operation - the lowest for any optical transmitter. In addition, we have demonstrated electrical pumping of photonic crystal nanobeam LEDs...

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Majumdar, Arka; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2012-01-01T23:59:59.000Z

158

Styrene Purification and Recovery Using Freeze Crystallization  

E-Print Network [OSTI]

Lab tests have demonstrated the ability to separate styrene from ABS and SAN plastics wastes by cooling the waste until the styrene begins to crystallize. The same process that recovers styrene from these wastes can be used to purify styrene...

Heist, J. A.; Wrobel, P. J.

159

The Crystal Method: Asteroseismology of BPM 37093  

E-Print Network [OSTI]

More than 40 years have passed since Ed Salpeter and others predicted that the carbon/oxygen cores of the coolest white dwarf stars in our Galaxy will theoretically crystallize. This effect has a dramatic impact on the calculated ages of cool white dwarfs, but until recently we have had no way of testing the theory. In 1992, pulsations were discovered in the massive potentially crystallized white dwarf BPM 37093, and in 1999 the theoretical effects of crystallization on the pulsation modes were determined. Observations from two Whole Earth Telescope campaigns in 1998 and 1999, combined with a new model-fitting method using a genetic algorithm, are now giving us the first glimpse inside of a crystallized star.

T. S. Metcalfe; M. H. Montgomery; A. Kanaan

2004-08-19T23:59:59.000Z

160

Nanoparticle-chiral nematic liquid crystal composites  

E-Print Network [OSTI]

The advancement of the fabrication of a one-dimensional photonic crystal without time-reversal and space-inversion symmetries was pursued. Theoretical studies predict that such a system would exhibit unusual optical ...

Payne, Jeffrey C. (Jeffrey Christopher), 1981-

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Thermophysical parameters of the LBO crystal  

SciTech Connect (OSTI)

The thermophysical parameters (linear thermal expansion coefficients, thermal conductivities, and heat capacity) of the lithium triborate (LBO) crystal are measured and compared with previously published data. (nonlinear-optics phenomena)

Grechin, Sergei G [Scientific-Research Institute of Radioelectronics and Laser Technology at the N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); Zuev, A V; Fokin, A S [All-Russian Scientific Research Institute of Aviation Materials, Moscow (Russian Federation); Kokh, Aleksandr E [V.S.Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Moiseev, N V; Popov, Petr A; Sidorov, Aleksei A [Acad. I. G. Petrovskii Bryansk State University, Bryansk (Russian Federation)

2010-08-27T23:59:59.000Z

162

The study of organic crystals by atomic force microscopy  

E-Print Network [OSTI]

]. Among others, such interactions include hydrogen bonding, halogen bonding, as well as pi-pi interactions [4]. By understanding the behaviour of these interactions, crystal engineering was developed not only for the study of crystal structures, but also... and crystal engineering . . . . . . . . . . . . . 1 1.2 Application of crystal engineering in pharmaceutical materials sciences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2.1 Studying drug components . . . . . . . . . . . . . . . . . 2 1...

Chow, Ernest Ho Hin

2014-07-01T23:59:59.000Z

163

Enhancement of crystal homogeneity of protein crystals under application of an external alternating current electric field  

SciTech Connect (OSTI)

X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white (HEW) lysozyme crystals grown with and without the application of an external alternating current (AC) electric field. The crystal quality was assessed by the full width at half maximum (FWHM) value for each rocking curve. For two-dimensional maps of the FWHMs measured on the 440 and the 12 12 0 reflection, the crystal homogeneity was improved under application of an external electric field at 1 MHz, compared with that without. In particular, the significant improvement of the crystal homogeneity was observed for the 12 12 0 reflection.

Koizumi, H.; Uda, S.; Fujiwara, K.; Nozawa, J. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Tachibana, M. [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, 236-0027 (Japan); Kojima, K. [Department of Education, Yokohama Soei University, 1 Miho-tyou, Midori-ku, Yokohama, 226-0015 (Japan)

2014-10-06T23:59:59.000Z

164

Method for reducing energy losses in laser crystals  

DOE Patents [OSTI]

A process for reducing energy losses in crystals is disclosed which comprises: a. heating a crystal to a temperature sufficiently high as to cause dissolution of microscopic inclusions into the crystal, thereby converting said inclusions into point-defects, and b. maintaining said crystal at a given temperature for a period of time sufficient to cause said point-defects to diffuse out of said crystal. Also disclosed are crystals treated by the process, and lasers utilizing the crystals as a source of light. 12 figs.

Atherton, L.J.; DeYoreo, J.J.; Roberts, D.H.

1992-03-24T23:59:59.000Z

165

P-156 / G. Hegde P-156: Alignment of Ferroelectric Liquid Crystals with the Substrates  

E-Print Network [OSTI]

from JSR. The polymer layers were spin coated at 3000 rpm on glass slides (2x3 cm) containing patterned layer source (ALS) with a race track shaped glow discharge area [7, 10]. In the beam mode, this source irradiation. The incidence angle of plasma beam was about 70 . The distance between discharge area and treated

166

Surface Energy,Surface Energy, Surface Tension & Shape of CrystalsSurface Tension & Shape of Crystals  

E-Print Network [OSTI]

Surface Energy,Surface Energy, Surface Tension & Shape of CrystalsSurface Tension & Shape of shapes of crystals are important: (i) growth shape and (ii) equilibrium shape Surface/interface energy surfaces. The joining of two phases creates an interface. (Two orientations of the same crystalline phase

Subramaniam, Anandh

167

Charge transfer reactions in nematic liquid crystals  

SciTech Connect (OSTI)

Ultrafast transient absorption studies of intramolecular photoinduced charge separation and thermal charge recombination were carried out on a molecule consisting of a 4-(N-pyrrolidino)naphthalene-1,8-imide donor (PNI) covalently attached to a pyromellitimide acceptor (PI) dissolved in the liquid crystal 4{prime}-(n-pentyl)-4-cyanobiphenyl (5CB). The temperature dependencies of the charge separation and recombination rates were obtained at temperatures above the nematic-isotropic phase transition of 5CB, where ordered microdomains exist and scattering of visible light by these domains is absent. The authors show that excited state charge separation is dominated by molecular reorientation of 5CB perpendicular to the director within the liquid crystal microdomains. They also show that charge recombination is adiabatic and is controlled by the comparatively slow collective reorientation of the liquid crystal microdomains relative to the orientation of PNI{sup +}-PI{sup {minus}}. They also report the results of time resolved electron paramagnetic resonance (TREPR) studies of photoinduced charge separation in a series of supramolecular compounds dissolved in oriented liquid crystal solvents. These studies permit the determination of the radical pair energy levels as the solvent reorganization energy increases from the low temperature crystalline phase, through the soft glass phase, to the nematic phase of the liquid crystal.

Wiederrecht, G.P. [Argonne National Lab., IL (United States). Chemistry Div.; Wasielewski, M.R. [Argonne National Lab., IL (United States). Chemistry Div.; [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Galili, T.; Levanon, H. [Hebrew Univ. of Jerusalem (Israel). Dept. of Physical Chemistry

1998-07-01T23:59:59.000Z

168

Crystal Chemistry of Th in Fluorapatite  

SciTech Connect (OSTI)

Through the complementary use of single-crystal X-ray diffraction and X-ray absorption spectroscopy, we present in this paper the first direct results on the site occupancy of thorium in the fluorapatite structure and the structural distortion created by its substitution. Structure refinements based on single-crystal X-ray diffraction data from synthetic Th-doped fluorapatite indicates that Th substitutes almost exclusively in the M2 site. A single-crystal X-ray study of natural fluorapatite from Mineville, New York, also indicated that substituting heavy scatterers (including Th) are concentrated in the apatite M2 site, but definitive site assignments of specific elements were not possible. Extended X-ray absorption fine-structure spectroscopy (EXAFS) was used to probe the local structure of Th in the synthetic fluorapatite (single-crystal form) with a Th concentration of roughly 20000 ppm, as well as Th in the natural Mineville fluorapatite (powder form) with a Th concentration of {approx}2000 ppm. The EXAFS fitting results also indicate that Th partitions into the M2 site and yield a {approx}0.05-0.08 {angstrom} decrease of average M2-O bond distances associated with local structure distortions that are not obtainable from single-crystal X-ray diffraction studies.

Y Luo; J Rakovan; Y Tang; M Lupulescu; J Hughes; Y Pan

2011-12-31T23:59:59.000Z

169

Density functional theory for carbon dioxide crystal  

SciTech Connect (OSTI)

We present a density functional approach to describe the solid?liquid phase transition, interfacial and crystal structure, and properties of polyatomic CO{sub 2}. Unlike previous phase field crystal model or density functional theory, which are derived from the second order direct correlation function, the present density functional approach is based on the fundamental measure theory for hard-sphere repulsion in solid. More importantly, the contributions of enthalpic interactions due to the dispersive attractions and of entropic interactions arising from the molecular architecture are integrated in the density functional model. Using the theoretical model, the predicted liquid and solid densities of CO{sub 2} at equilibrium triple point are in good agreement with the experimental values. Based on the structure of crystal-liquid interfaces in different planes, the corresponding interfacial tensions are predicted. Their respective accuracies need to be tested.

Chang, Yiwen; Mi, Jianguo, E-mail: mijg@mail.buct.edu.cn; Zhong, Chongli [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

2014-05-28T23:59:59.000Z

170

Ultrasonically assisted deposition of colloidal crystals  

SciTech Connect (OSTI)

Colloidal particles are a versatile physical system which have found uses across a range of applications such as the simulation of crystal kinetics, etch masks for fabrication, and the formation of photonic band-gap structures. Utilization of colloidal particles often requires a means to produce highly ordered, periodic structures. One approach is the use of surface acoustic waves (SAWs) to direct the self-assembly of colloidal particles. Previous demonstrations using standing SAWs were shown to be limited in terms of crystal size and dimensionality. Here, we report a technique to improve the spatial alignment of colloidal particles using traveling SAWs. Through control of the radio frequency power, which drives the SAW, we demonstrate enhanced quality and dimensionality of the crystal growth. We show that this technique can be applied to a range of particle sizes in the ?m-regime and may hold potential for particles in the sub-?m-regime.

Wollmann, Sabine, E-mail: sabine.wollmann@griffithuni.edu.au [Lehrstuhl für Experimentalphysik 1 and Augsburg Centre for Innovative Technologies (ACIT), Universität Augsburg, 86159 Augsburg (Germany); Centre for Quantum Dynamics, Griffith University, Brisbane 4111 (Australia); Patel, Raj B. [Centre for Quantum Dynamics, Griffith University, Brisbane 4111 (Australia); Wixforth, Achim; Krenner, Hubert J. [Lehrstuhl für Experimentalphysik 1 and Augsburg Centre for Innovative Technologies (ACIT), Universität Augsburg, 86159 Augsburg (Germany); Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80779 München (Germany)

2014-07-21T23:59:59.000Z

171

Nano-crystal growth in cordierite glass ceramics studied with X-ray scattering  

E-Print Network [OSTI]

Nano-crystal growth in cordierite glass ceramics studiedmatrix in which crystalline nano-crystals are embedded. Bysample the Cr containing spinel nano crystals. In these SEM

Bras, Wim

2010-01-01T23:59:59.000Z

172

Seismic Crystals And Earthquake Shield Application  

E-Print Network [OSTI]

We theoretically demonstrate that earthquake shield made of seismic crystal can damp down surface waves, which are the most destructive type for constructions. In the paper, seismic crystal is introduced in aspect of band gaps (Stop band) and some design concepts for earthquake and tsunami shielding were discussed in theoretical manner. We observed in our FDTD based 2D elastic wave simulations that proposed earthquake shield could provide about 0.5 reductions in magnitude of surface wave on the Richter scale. This reduction rate in magnitude can considerably reduce destructions in the case of earthquake.

B. Baykant Alagoz; Serkan Alagoz

2009-05-15T23:59:59.000Z

173

Anisotropic wave propagation in nematic liquid crystals  

E-Print Network [OSTI]

Despite the fact that quantitative experimental data have been available for more than forty years now, nematoacoustics still poses intriguing theoretical and experimental problems. In this paper, we prove that the main observed features of acoustic wave propagation through a nematic liquid crystal cell -- namely, the anisotropy of sound velocity and its frequency dependence -- may be plausibly explained by a first-gradient continuum theory characterized by a hyperelastic anisotropic response from an evolving relaxed configuration. We compare and contrast our proposal with a competing theory where the liquid crystal is modeled as an isotropically compressible, anisotropic second-gradient fluid.

Paolo Biscari; Antonio DiCarlo; Stefano S. Turzi

2014-05-10T23:59:59.000Z

174

Metamaterial model of a time crystal  

E-Print Network [OSTI]

Propagation of monochromatic extraordinary light in a hyperbolic metamaterial is identical to propagation of massive particles in a three dimensional effective Minkowski spacetime, in which the role of a timelike variable is played by one of the spatial coordinates. We demonstrate that this analogy may be used to build a metamaterial model of a time crystal, which has been recently suggested by Wilczek and Shapere. It is interesting to note that the effective single-particle energy spectrum in such a model does not contain a static ground state, thus providing a loophole in the proof of time crystal non-existence by P. Bruno.

Smolyaninov, Igor I

2015-01-01T23:59:59.000Z

175

A Benchmark Construction of Positron Crystal Undulator  

E-Print Network [OSTI]

Optimization of a positron crystal undulator (CU) is addressed. The ways to assure both the maximum intensity and minimum spectral width of positron CU radiation are outlined. We claim that the minimum CU spectrum width of 3 -- 4% is reached at the positron energies of a few GeV and that the optimal bending radius of crystals planes in CU ranges from 3 to 5 critical bending radii for channeled particles. Following suggested approach a benchmark positron CU construction is devised and its functioning is illustrated using the simulation method widely tested by experimental data.

Tikhomirov, Victor V

2015-01-01T23:59:59.000Z

176

Computer-aided rational solvent selection for pharmaceutical crystallization  

E-Print Network [OSTI]

Solvents play an important role in crystallization, a commonly used separation and purification technique in the pharmaceutical, chemical and food industries. They affect crystal properties such as particle size distribution, ...

Chen, Jie, Ph. D. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

177

Morphological control of silicalite-1 crystals using microemulsion mediated growth  

E-Print Network [OSTI]

mediated synthesis, it is concluded that the surfactant??silicate interactions are primarily responsible for the modulation of crystal morphology observed. The results indicate that surfactant adsorption on the growing crystal surface, not the confined...

Lee, Seung Ju

2005-11-01T23:59:59.000Z

178

Experimental studies of melting and crystallization processes in planetary interiors  

E-Print Network [OSTI]

Melting and crystallization processes on the Earth and Moon are explored in this thesis, and the topics of melt generation, transport, and crystallization are discussed in three distinct geologic environments: the Moon's ...

Krawczynski, Michael James

2011-01-01T23:59:59.000Z

179

Anomalous phenomena and spectral tailoring in photonic crystals  

E-Print Network [OSTI]

Photonic crystals are recently discovered meta-materials whose optical properties arise from periodic refractive index variations. In this thesis I examine various aspects of photonic crystals including a self-assembled ...

Ghebrebrhan, Michael

2010-01-01T23:59:59.000Z

180

Two-dimensional Photonic Crystals Fabricated by Nanoimprint Lithography  

E-Print Network [OSTI]

We report on the process parameters of nanoimprint lithography (NIL) for the fabrication of two-dimensional (2-D) photonic crystals. The nickel mould with 2-D photonic crystal patterns covering the area up to 20mm² is ...

Chen, A.

Note: This page contains sample records for the topic "tiny crystals glow" 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

New Crystal Structures Lift Fog around Protein Folding  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

New Crystal Structures Lift Fog around Protein Folding New Crystal Structures Lift Fog around Protein Folding Print Wednesday, 25 July 2012 00:00 Nature's proteins set a high bar...

182

Thin magnetic crystals are path to ferromagnetic graphene | ornl...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Thin magnetic crystals are path to ferromagnetic graphene January 23, 2015 The crystal structure of CrI3 includes hexagonal nets formed by Cr atoms (blue) with magnetic moments...

183

Nepheline crystallization in boron-rich alumino-silicate glasses...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Nepheline crystallization in boron-rich alumino-silicate glasses as investigated by multi-nuclear NMR, Raman, & Mö Nepheline crystallization in boron-rich alumino-silicate...

184

5.067 Crystal Structure Refinement, Fall 2007  

E-Print Network [OSTI]

This course in crystal structure refinement examines the practical aspects of crystal structure determination from data collection strategies to data reduction and basic and advanced refinement problems of organic and ...

Mueller, Peter

185

5.841 Crystal Structure Refinement, Fall 2006  

E-Print Network [OSTI]

This course in crystal structure refinement examines the practical aspects of crystal structure determination from data collection strategies to data reduction and basic and advanced refinement problems of organic and ...

Mueller, Peter

186

Synthetic thermoelectric materials comprising phononic crystals  

DOE Patents [OSTI]

Synthetic thermoelectric materials comprising phononic crystals can simultaneously have a large Seebeck coefficient, high electrical conductivity, and low thermal conductivity. Such synthetic thermoelectric materials can enable improved thermoelectric devices, such as thermoelectric generators and coolers, with improved performance. Such synthetic thermoelectric materials and devices can be fabricated using techniques that are compatible with standard microelectronics.

El-Kady, Ihab F; Olsson, Roy H; Hopkins, Patrick; Reinke, Charles; Kim, Bongsang

2013-08-13T23:59:59.000Z

187

UV STABILITY OF HIGH BIREFIRNGENCE LIQUID CRYSTALS  

E-Print Network [OSTI]

nm, the major UV light used for curing sealant. The material degradation is believed to originate experimental results indicate that the UV degradation not only depends on the absorption wavelength but alsoUV STABILITY OF HIGH BIREFIRNGENCE LIQUID CRYSTALS Pao-Tai Lin and Shin-Tson Wu School of Optics

Wu, Shin-Tson

188

Organizing Carbon Nanotubes with Liquid Crystals  

E-Print Network [OSTI]

Organizing Carbon Nanotubes with Liquid Crystals Michael D. Lynch and David L. Patrick* Department, 2002; Revised Manuscript Received September 13, 2002 ABSTRACT Single- and multiwalled carbon nanotubes- and multiwalled carbon nanotubes (SWCNT and MWCNT) are of particular interest because these materials

Patrick, David L.

189

Crystal Engineering Morphosynthesis of Rhombododecahedral Silver  

E-Print Network [OSTI]

of metal nanoparticles; examples include silver nanorods,[17] nanoprisms,[18] and nano- cubes.[19] Hollow of primary building blocks into hollow spheres or cages,[9­14] as these hollow structures with nanometer, and as photonic crystals.[15] In most cases, however, only spherical hollow structures have been obtained either

Qi, Limin

190

Coulomb crystals in the harmonic lattice approximation  

E-Print Network [OSTI]

The dynamic structure factor ${\\tilde S}({\\bf k},\\omega)$ and the two-particle distribution function $g({\\bf r},t)$ of ions in a Coulomb crystal are obtained in a closed analytic form using the harmonic lattice (HL) approximation which takes into account all processes of multi-phonon excitation and absorption. The static radial two-particle distribution function $g(r)$ is calculated for classical ($T \\gtrsim \\hbar \\omega_p$, where $\\omega_p$ is the ion plasma frequency) and quantum ($T \\ll \\hbar \\omega_p$) body-centered cubic (bcc) crystals. The results for the classical crystal are in a very good agreement with extensive Monte Carlo (MC) calculations at $1.5 \\lesssim r/a \\lesssim 7$, where $a$ is the ion-sphere radius. The HL Coulomb energy is calculated for classical and quantum bcc and face-centered cubic crystals, and anharmonic corrections are discussed. The inelastic part of the HL static structure factor $S''(k)$, averaged over orientations of wave-vector {\\bf k}, is shown to contain pronounced singularities at Bragg diffraction positions. The type of the singularities is different in classical and quantum cases. The HL method can serve as a useful tool complementary to MC and other numerical methods.

D. A. Baiko; D. G. Yakovlev; H. E. De Witt; W. L. Slattery

1999-12-23T23:59:59.000Z

191

Crystal fields in UO2 - revisited  

SciTech Connect (OSTI)

We performed inelastic neutron scattering (INS) in order to re-investigate the crystal-field ground state and the level splitting in UO{sub 2}. Previous INS studies on UO{sub 2} by Amorelli et al. [Physical Review B 15, 1989, 1856] uncovered four excitations at low temperatures in the 150-180 meV range. Considering the dipole-allowed transitions, only three of these transitions could be explained by the published crystal-field model. Our INS results on a different UO{sub 2} sample revealed that the unaccounted peak at about 180 meV is a spurious one, and thus not intrinsic to UO{sub 2}. In good agreement with Amoretti's results, we corroborated that the ground-state of UO{sub 2} is the {Lambda}{sub 5} triplet, and we computed that the fourth- and six-order crystal field parameters are V{sub 4} = -116 meV and V{sub 6} = 26 meV, respectively. We also studied the INS response of the non-magnetic U{sub 0.4}Th{sub 0.6}O{sub 2}. The splitting for this thorium-doped compound is similar to the one of UO{sub 2}, which orders antiferromagnetically at low temperatures. Therefore, we can conclude that magnetic interactions only weakly perturb the energy level splitting, which is dominated by strong crystal fields.

Nakotte, Heinz [Los Alamos National Laboratory; Rajatram, R [NMSU/UNIV OF N.C.; Kern, S [COLORADO STATE UNIV; Mcqueeney, R J [AMES LAB; Lander, G H [EUROPEAN COMMISIONS, JRC; Robinson, R A [BRAGG INSTITUTE

2009-01-01T23:59:59.000Z

192

Statistical Analysis of Crystallization Database Links Protein Physico-Chemical Features with Crystallization Mechanisms  

E-Print Network [OSTI]

X-ray crystallography is the predominant method for obtaining atomic-scale information about biological macromolecules. Despite the success of the technique, obtaining well diffracting crystals still critically limits going ...

Fusco, Diana

193

Ytterbium- and neodymium-doped vanadate laser hose crystals having the apatite crystal structure  

DOE Patents [OSTI]

Yb.sup.3+ and Nd.sup.3+ doped Sr.sub.5 (VO.sub.4).sub.3 F crystals serve as useful infrared laser media that exhibit low thresholds of oscillation and high slope efficiencies, and can be grown with high optical quality. These laser media possess unusually high absorption and emission cross sections, which provide the crystals with the ability to generate greater gain for a given amount of pump power. Many related crystals such as Sr.sub.5 (VO.sub.4).sub.3 F crystals doped with other rare earths, transition metals, or actinides, as well as the many structural analogs of Sr.sub.5 (VO.sub.4).sub.3 F, where the Sr.sup.2+ and F.sup.- ions are replaced by related chemical species, have similar properties.

Payne, Stephen A. (Castro Valley, CA); Kway, Wayne L. (Fremont, CA); DeLoach, Laura D. (Manteca, CA); Krupke, William F. (Pleasanton, CA); Chai, Bruce H. T. (Oviedo, FL)

1994-01-01T23:59:59.000Z

194

Liquid crystals and Q-tensors The free energy  

E-Print Network [OSTI]

Liquid crystals and Q-tensors The free energy A temperature-dependent model Mathematical results #12;Liquid crystals and Q-tensors The free energy A temperature-dependent model Mathematical results, Non-isothermal nematic liquid crystals flows with the Ball-Majumdar free energy, Ann. Mat. Pura Appl

Segatti, Antonio

195

D-D Nuclear Fusion Using Different Size Pyroelectric Crystals  

E-Print Network [OSTI]

D-D Nuclear Fusion Using Different Size Pyroelectric Crystals A. M. Kovanen, D. J. Gillich, T. Z the conditions for D-D fusion in pyroelectric crystal accelerators. Three different pyroelectric crystal sizes are with the Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY. A. M

Danon, Yaron

196

Giant Plasticity of a Quantum Crystal Ariel Haziot,1  

E-Print Network [OSTI]

Giant Plasticity of a Quantum Crystal Ariel Haziot,1 Xavier Rojas,1 Andrew D. Fefferman,1 John R crystals may irreversibly deform. This phenomenon is known as plasticity and it is due to the motion and in the zero temperature limit, helium 4 crystals present a giant plasticity that is anisotropic and reversible

Balibar, Sébastien

197

E-Print Network 3.0 - alpha-zr single crystals Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Igneous crystallization Gabbro: Plagioclase MgFe Pyroxene... (Opal, Jasper) Hematite Crystallization via ,,solute ... Source: Browne, Brandon L. - Department of...

198

Induced Positron Annihiliation Investigation of Cadmium Zinc Telluride Crystal Microstructures  

SciTech Connect (OSTI)

Cadmium-Zinc-Telluride (CZT) crystals are used in semiconductor radiation detectors for the detection of x-ray and gamma radiation. However, production of detector grade crystals is difficult as small variations in compositional uniformity and primarily the zinc content can significantly affect the ability of the CZT crystal to function as a radiation detector. Currently there are no known nondestructive methods that can be used to identify detector grade crystals. The current test method is to fabricate and test the detector to determine if the crystal is sufficiently uniform and of the correct composition to be considered a detector grade crystal. Consequently, nondestructive detection methods are needed to identify detector grade crystals prior to the fabrication process. The purpose of this feasibility study was to perform a preliminary assessment of the ability of several new, nondestructive technologies based on Induced Positron Annihilation (IPA) to determine if detector grade CZT crystals can be identified. Results of measurements performed on specimens from Fisk University and EV Products, Inc. indicate that both the near surface Distributed Source Positron Annihilation (up to 3 mm penetration) and the volumetric Photon Induced Positron Annihilation methods may be suitable for determining CZT crystal quality. Further work on CZT crystals with a broader range of compositions and detector characteristics is needed to provide a well defined, calibrated, method for assessing CZT crystal quality.

D. W. Akers

2005-06-01T23:59:59.000Z

199

High energy resolution, high angular acceptance crystal monochromator  

DOE Patents [OSTI]

A 4-bounce dispersive crystal monochromator reduces the bandpass of synchrotron radiation to a 10-50 meV range without sacrificing angular acceptance. The monochromator includes the combination of an asymmetrical channel-cut single crystal of lower order reflection and a symmetrical channel-cut single crystal of higher order reflection in a nested geometric configuration. In the disclosed embodiment, a highly asymmetrically cut (.alpha.=20) outer silicon crystal (4 2 2) with low order reflection is combined with a symmetrically cut inner silicon crystal (10 6 4) with high order reflection to condition a hard x-ray component (5-30 keV) of synchrotron radiation down to the .mu.eV-neV level. Each of the crystals is coupled to the combination of a positioning inchworm and angle encoder via a respective rotation stage for accurate relative positioning of the crystals and precise energy tuning of the monochromator.

Alp, Ercan E. (Bolingbrook, IL); Mooney, Timothy M. (Westmont, IL); Toellner, Thomas (Green Bay, WI)

1996-06-04T23:59:59.000Z

200

Low Radioactivity Crystals for Neutrinoless Double Beta Decay Detectors  

SciTech Connect (OSTI)

The production of crystals needed for rare events physics represent a relatively new, exciting challenge in the field of materials science and engineering. Extremely low concentration of radioactive impurities and very high crystal perfection is required for the crystals to be used in experiments in which the main concerns are the reduction of the background and the use of high sensitivity detectors. A further complication is the fact that for an experiment with a significant discovery potential, relatively large quantities of crystals are needed. The present work makes a review of the general problems related to the production of crystals for rare events physics and gives details related to the production of the TeO{sub 2} crystals needed for the major experiment in this field using bolometric technique, namely the CUORE experiment. The potential use of crystals for future double beta decay experiments is also discussed.

Dafinei, Ioan [Sezione INFN di Roma, P-le Aldo Moro 2, Roma I-00185 (Italy)

2011-04-27T23:59:59.000Z

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


201

UCN transport simulation in solid deuterium crystals  

E-Print Network [OSTI]

The extraction efficiency of ultracold neutrons from cryogenic moderators depends critically on the neutron transparency of the moderator material. The Monte Carlo simulation of the probability of the UCN going out from non-ideal (disordered) solid deuterium crystals has been performed. It was based on the use of the correlation function describing the density fluctuations in a disordered material, the latter being inferred from the measured very low neutron energy total cross sections for this material.

Yu. N. Pokotilovski

2012-03-04T23:59:59.000Z

202

Crystal growth furnace with trap doors  

DOE Patents [OSTI]

An improved furnace is provided for growing crystalline bodies from a melt. The improved furnace is characterized by a door assembly which is remotely controlled and is arranged so as to selectively shut off or permit communication between an access port in the furnace enclosure and a hot zone within that enclosure. The invention is especially adapted to facilitate use of crystal growing cartridges of the type disclosed in U.S. Pat. No. 4,118,197.

Sachs, Emanual M. (Watertown, MA); Mackintosh, Brian H. (Lexington, MA)

1982-06-15T23:59:59.000Z

203

Dynamics of Quantum Dot Photonic Crystal Lasers  

E-Print Network [OSTI]

Quantum dot photonic crystal membrane lasers were fabricated and the large signal modulation characteristics were studied. We find that the modulation characteristics of quantum dot lasers can be significantly improved using cavities with large spontaneous emission coupling factor. Our experiments show, and simulations confirm, that the modulation rate is limited by the rate of carrier capture into the dots to around 30GHz in our present system.

Bryan Ellis; Ilya Fushman; Dirk Englund; Bingyang Zhang; Yoshihisa Yamamoto; Jelena Vuckovic

2007-03-07T23:59:59.000Z

204

Method for fabricating apatite crystals and ceramics  

DOE Patents [OSTI]

The present invention provides a method of crystallizing Yb:C-FAP [Yb.sup.3+:Ca.sub.5(PO.sub.4).sub.3F], by dissolving the Yb:C-FAP in an acidic solution, following by neutralizing the solution. The present invention also provides a method of forming crystalline Yb:C-FAP by dissolving the component ingredients in an acidic solution, followed by forming a supersaturated solution.

Soules, Thomas F.; Schaffers, Kathleen I.; Tassano, Jr., John B.; Hollingsworth, Joel P.

2013-09-10T23:59:59.000Z

205

Crystal Lake III | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentratingRenewable Solutions LLC JumpCrow Lake Wind Jump to: navigation,Cryogenic(08)Crystal

206

A 1-D dusty plasma photonic crystal  

SciTech Connect (OSTI)

It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 ?m to about 1350 ?m, depending on the rf power fed into the discharge.

Mitu, M. L.; Tico?, C. M. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania)] [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Toader, D.; Banu, N.; Scurtu, A. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania) [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Department of Physics, University of Bucharest, 077125 Bucharest (Romania)

2013-09-21T23:59:59.000Z

207

Predicting Polymeric Crystal Structures by Evolutionary Algorithms  

E-Print Network [OSTI]

The recently developed evolutionary algorithm USPEX proved to be a tool that enables accurate and reliable prediction of structures for a given chemical composition. Here we extend this method to predict the crystal structure of polymers by performing constrained evolutionary search, where each monomeric unit is treated as one or several building blocks with fixed connectivity. This greatly reduces the search space and allows the initial structure generation with different sequences and packings using these blocks. The new constrained evolutionary algorithm is successfully tested and validated on a diverse range of experimentally known polymers, namely polyethylene (PE), polyacetylene (PA), poly(glycolic acid) (PGA), poly(vinyl chloride) (PVC), poly(oxymethylene) (POM), poly(phenylene oxide) (PPO), and poly (p-phenylene sulfide) (PPS). By fixing the orientation of polymeric chains, this method can be further extended to predict all polymorphs of poly(vinylidene fluoride) (PVDF), and the complex linear polymer crystals, such as nylon-6 and cellulose. The excellent agreement between predicted crystal structures and experimentally known structures assures a major role of this approach in the efficient design of the future polymeric materials.

Qiang Zhu; Vinit Sharma; Artem R Oganov; Rampi Ramprasad

2014-06-05T23:59:59.000Z

208

DHS Internship Summary-Crystal Assembly at Different Length Scales  

SciTech Connect (OSTI)

I was part of a project in which in situ atomic force microscopy (AFM) was used to monitor growth and dissolution of atomic and colloidal crystals. At both length scales, the chemical environment of the system greatly altered crystal growth and dissolution. Calcium phosphate was used as a model system for atomic crystals. A dissolution-reprecipitation reaction was observed in this first system, involving the conversion of brushite (DCPD) to octacalcium phosphate (OCP). In the second system, polymeric colloidal crystals were dissolved in an ionic solvent, revealing the underlying structure of the crystal. The dissolved crystal was then regrown through an evaporative step method. Recently, we have also found that colloids can be reversibly deposited in situ onto an ITO (indium tin oxide) substrate via an electrochemistry setup. The overall goal of this project was to develop an understanding of the mechanisms that control crystallization and order, so that these might be controlled during material synthesis. Controlled assembly of materials over a range of length scales from molecules to nanoparticles to colloids is critical for designing new materials. In particular, developing materials for sensor applications with tailorable properties and long range order is important. In this work, we examine two of these length scales: small molecule crystallization of calcium phosphate (whose crystal phases include DCPD, OCP, and HAP) and colloidal crystallization of Poly(methyl methacrylate) beads. Atomic Force Microscopy is ideal for this line of work because it allows for the possibility of observing non-conducting samples in fluid during growth with high resolution ({approx} 10 nm). In fact, during atomic crystal growth one can observe changes in atomic steps, and with colloidal crystals, one can monitor the individual building blocks of the crystal. Colloids and atoms crystallize under the influence of different forces acting at different length scales as seen in Table 1. In particular, molecular crystals, which are typically dominated by ionic and covalent bonding, are an order of magnitude more strongly bonded than colloidal crystals. In molecular crystals, ordering is driven by the interaction potentials between molecules. By contrast, colloidal assembly is a competition between the repulsive electrostatic forces that prevent aggregation in solution (due to surface charge), and short-range van der Waals and entropic forces that leads to ordering. Understanding atomic crystallization is fundamentally important for fabrication of tailorable crystalline materials, for example for biological or chemical sensors. The transformation of brushite to OCP not only serves as a model system for atomic crystal growth (applicable to many other crystal growth processes), but is also important in bone cements. Colloidal crystals have unique optical properties which respond to chemical and mechanical stimuli, making them very important for sensing applications. The mechanism of colloidal crystal assembly is thus fundamentally important. Our in situ dissolution and regrowth experiments are one good method of analyzing how these crystals pack under different conditions and how defect sites are formed and filled. In these experiments, a silica additive was used to strengthen the colloidal crystal during initial assembly (ex situ) and to increase domain size and long range order. Reversible electrodeposition of colloids onto a conductive substrate (ITO in our case) is another system which can further our knowledge of colloidal assembly. This experiment holds promise of allowing in situ observation of colloidal crystal growth and the influence of certain additives on crystal order. The ultimate goal would be to achieve long range order in these crystals by changing the surface charge or the growth environment.

Mishchenko, L

2009-08-06T23:59:59.000Z

209

What about Bulk Objects? "All things glow"  

E-Print Network [OSTI]

energy emission T = temperature of the object As T , max As T , TOTAL[E] P = E/t =AT4 = object, trapping energy from the sun" (www.ucar.edu) #12;Note: 1) Atmospheric convection should increase in global to the "Encounter with Energy"...! ! How Is Energy Encountered... or Transferred? 1. Electromagnetic Waves (just

210

Crystallization of Sodium Phosphate Dodecahydrate and Re-Crystallization to Natrophosphate in Simulated Hanford Nuclear Waste  

SciTech Connect (OSTI)

The nuclear waste at the Hanford site near Richland, WA, has large concentrations of phosphate in the form of the phosphate ion, sodium phosphate dodecahydrate (Na3PO4.12H2O.(1/4)NaOH) and natrophosphate (Na7F(PO4)3.19H2O). Sodium phosphate dodecahydrate can form a gel and natrophosphate can crystallize large particles, complicating the processing of slurries of both salts. The gel is regarded as more problematic, so natrophosphate has historically been crystallized to prevent phosphate gelling. This study determined that natrophosphate crystals can grow to large size in short time periods (a few weeks), time periods relevant to short process shutdowns. Solutions of NaOH and NaAl(OH)4 were blended at different ratios with stock solutions containing NaOH, NaF, and Na3PO4 at 50 °C. The mixtures were allowed to cool to 22 °C, and the crystal growth was monitored by Polarized Light Microscopy (PLM) for 17 days. Four of the six blends investigated gelled rapidly due to Na3PO4.12H2O.(1/4)NaOH precipitation. The gel slowly dissipated over time as the solids recrystallized into natrophosphate. In one case, the natrophosphate reached sizes of greater than 1000 microns in diameter in just 4 days. This rapid gelling and crystallization kinetics is important to engineers trying to manage nuclear wastes high in phosphates. Hanford tank farm engineers are developing sampling plans to support temperature and process control strategies for preventing the formation of solid phosphates. They are also developing methods of suspending large natrophosphate crystals.

Reynolds, J. G.

2014-12-22T23:59:59.000Z

211

Growth and characterisation of kh2 po4 kdp crystals doped with metal ions dyes amino acids and effect of swift heavy ion irradiation on doped kdp crystals;.  

E-Print Network [OSTI]

??The beauty of crystals has always been fascinating Crystals lie at newlinethe root of todays advanced technology Over the past few decades the newlineadvancement in… (more)

Kumaresan P

2015-01-01T23:59:59.000Z

212

Non-linear optical crystal vibration sensing device  

DOE Patents [OSTI]

A non-linear optical crystal vibration sensing device including a photorefractive crystal and a laser is disclosed. The laser produces a coherent light beam which is split by a beam splitter into a first laser beam and a second laser beam. After passing through the crystal the first laser beam is counter-propagated back upon itself by a retro-mirror, creating a third laser beam. The laser beams are modulated, due to the mixing effect within the crystal by vibration of the crystal. In the third laser beam, modulation is stable and such modulation is converted by a photodetector into a usable electrical output, intensity modulated in accordance with vibration applied to the crystal. 3 figs.

Kalibjian, R.

1994-08-09T23:59:59.000Z

213

Non-linear optical crystal vibration sensing device  

DOE Patents [OSTI]

A non-linear optical crystal vibration sensing device (10) including a photorefractive crystal (26) and a laser (12). The laser (12 ) produces a coherent light beam (14) which is split by a beam splitter (18) into a first laser beam (20) and a second laser beam (22). After passing through the crystal (26) the first laser beam (20) is counter-propagated back upon itself by a retro-mirror (32), creating a third laser beam (30). The laser beams (20, 22, 30) are modulated, due to the mixing effect within the crystal (26) by vibration of the crystal (30). In the third laser beam (30), modulation is stable and such modulation is converted by a photodetector (34) into a usable electrical output, intensity modulated in accordance with vibration applied to the crystal (26).

Kalibjian, Ralph (Livermore, CA)

1994-01-11T23:59:59.000Z

214

Plasmonic crystal enhanced refractive index sensing  

SciTech Connect (OSTI)

We demonstrate experimentally how the local anisotropy of the dispersion relation of surface plasmon modes propagating over periodic metal gratings can lead to an enhancement of the figure of merit of refractive index sensors. Exploiting the possibility to acquire defocused images of the Fourier space of a highly stable leakage radiation microscope, we report a twofold increase in sensing sensitivity close to the band gap of a one-dimensional plasmonic crystal where the anisotropy of the band structure is the most important. A practical sensing resolution of O(10{sup ?6}) refractive index units is demonstrated.

Stein, Benedikt; Devaux, Eloïse; Genet, Cyriaque, E-mail: genet@unistra.fr; Ebbesen, Thomas W. [ISIS and icRFC, University of Strasbourg and CNRS, 8 allée Gaspard Monge, 67000 Strasbourg (France)

2014-06-23T23:59:59.000Z

215

Super-collimation by axisymmetric photonic crystals  

SciTech Connect (OSTI)

We propose and experimentally show the mechanism of beam super-collimation by axisymmetric photonic crystals, specifically by periodic (in propagation direction) structure of layers of concentric rings. The physical mechanism behind the effect is an inverse scattering cascade of diffracted wave components back into on- and near-axis angular field components, resulting in substantial enhancement of intensity of these components. We explore the super-collimation by numerical calculations and prove it experimentally. We demonstrate experimentally the axial field enhancement up to 7 times in terms of field intensity.

Purlys, V.; Gailevi?ius, D.; Peckus, M.; Gadonas, R. [Laser Research Center, Department of Quantum Electronics, Vilnius University, Saul?tekio Ave. 10, LT-10222 Vilnius (Lithuania); Maigyte, L. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa (Spain); Staliunas, K. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys, 23, 08010 Barcelona (Spain)

2014-06-02T23:59:59.000Z

216

Melting of superheated crystals initiates on vacancies  

E-Print Network [OSTI]

In a large variety of ideal crystals we found that when rapidly migrating atoms squash or annihilate a neighbouring vacancy and produce a disordered cluster, the heat of migration stored in the system exceeds the enthalpy increase required for the coordinating atoms of the vacancy to form a liquid phase, i.e. the liquid phase nucleates from vacancies. Furthermore volumetric analysis supports this well. This vacancy-decomposition model provides quantitative information on the melting point, the latent heat and the volume change upon melting and hence clarifies the mechanism of melting.

L. W. Wang; Q. Wang; K. Q. Lu

2010-07-24T23:59:59.000Z

217

Surface Vibrations in a Model Hcp Crystal  

E-Print Network [OSTI]

-1973. R. E. Allen, G. P. Alldredge, and F. W. de Wette, Phys. Rev. B 4, 1661 (3.971). 2R. E. Allen and F. W. de Wette, Phys. Rev. 179, 873 0.969). ..., and F. W. de Wette, Phys. Rev. B4, 1661 (1971). PHYSICA L RE VIE W 8 VOLUME 6, NUMBE R 2 15 JULY 1972 Surface Vibrations in a Model hcp Crystal R. E. Allen Department of Physics, Texas A @ M University, College Station, Texas 77843 and G. P...

Allen, Roland E.; Alldredg, GP; DEWITTE, FW.

1972-01-01T23:59:59.000Z

218

Crystal McDonald | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana. DOCUMENTS AVAILABLEReport 2009Site | Department of EnergytoRev.Crystal

219

Crystal J. Rodarte-Romero-Engineering  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases on &gamma;-Al2O3.Winter (Part267,273CondensateLayerCrystal J.

220

A Submarine Welded Ignimbrite-Crystal-Rich Sandstone Facies Associatio...  

Open Energy Info (EERE)

facies is interpreted to comprise deposits from syn-eruptive, crystal-rich, submarine sediment gravity flows that were generated by interaction of subaerial pyroclastic flows with...

Note: This page contains sample records for the topic "tiny crystals glow" 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

Diffraction crystals for sagittally focusing x-rays  

DOE Patents [OSTI]

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, G.E.; Sparks, C.J. Jr.

1982-06-07T23:59:59.000Z

222

Diffraction crystal for sagittally focusing x-rays  

DOE Patents [OSTI]

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, Gene E. (Oak Ridge, TN); Sparks, Jr., Cullie J. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

223

PHOTOCATALYTIC AND PHOTOELECTROCHEMICAL HYDROGEN PRODUCTION ON STRONTIUM TITANATE SINGLE CRYSTALS  

E-Print Network [OSTI]

AND PHOTOELECTROCHEMICAL HYDROGEN PRODUCTION ON STRONTIUMAND PHOTOELECTROCHEHICAL HYDROGEN PRODUCTION ON STRONTIUMand photocatalytic hydrogen production from SrTi0 3 crystals

Wagner, F.T.

2012-01-01T23:59:59.000Z

224

Supercontinuum generation in photonic crystal fibres: Modelling and dispersion engineering  

E-Print Network [OSTI]

Supercontinuum generation in photonic crystal fibres: Modelling and dispersion engineering . . . . . . . . . . . . . . . . . 22 2.4 The split-step Fourier method . . . . . . . . . . . . . . . . . . 25 #12;iv CONTENTS 2

225

Method for harvesting single crystals from a peritectic melt  

DOE Patents [OSTI]

A method of preparing single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals unmelted, allowing the wicking away of the peritectic liquid. 2 figs.

Todt, V.R.; Sengupta, S.; Shi, D.

1996-08-27T23:59:59.000Z

226

Method for harvesting single crystals from a peritectic melt  

DOE Patents [OSTI]

A method of preparing single crystals. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals unmelted, allowing the wicking away of the peritectic liquid.

Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

1996-01-01T23:59:59.000Z

227

Method for harvesting rare earth barium copper oxide single crystals  

DOE Patents [OSTI]

A method of preparing high temperature superconductor single crystals. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid.

Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

1996-01-01T23:59:59.000Z

228

Electric field effects in liquid crystals with dielectric dispersion  

SciTech Connect (OSTI)

The project is focused on the experimental and theoretical exploration of the coupling of an externally applied electric field and a nematic liquid crystal.

Lavrentovich, Oleg D. [Kent State University

2014-11-29T23:59:59.000Z

229

Method for the preparation of photochromic insulating crystals  

DOE Patents [OSTI]

A method for preparing reversible-photochromic magnesium oxide (MgO) crystals is disclosed. Single crystals of MgO doped with both lithium (Li) and nickel (Ni) are grown by a conventional arc fusion method. The as-grown crystals are characterized by an amber coloration. The crystals lose the amber coloration and become photochromic when they are thermochemically reduced by heating at temperatures greater then 1000/sup 0/K in a hydrogen atmosphere. Alternate irradiation with uv and visible light result in rejuvenation and bleaching of the amber coloration, respectively.

Abraham, M.M.; Boldu, J.L.; Chen, Y.; Orera, V.M.

1984-09-28T23:59:59.000Z

230

Solar cell structure incorporating a novel single crystal silicon material  

DOE Patents [OSTI]

A novel hydrogen rich single crystal silicon material having a band gap energy greater than 1.1 eV can be fabricated by forming an amorphous region of graded crystallinity in a body of single crystalline silicon and thereafter contacting the region with atomic hydrogen followed by pulsed laser annealing at a sufficient power and for a sufficient duration to recrystallize the region into single crystal silicon without out-gassing the hydrogen. The new material can be used to fabricate semiconductor devices such as single crystal silicon solar cells with surface window regions having a greater band gap energy than that of single crystal silicon without hydrogen.

Pankove, Jacques I. (Princeton, NJ); Wu, Chung P. (Trenton, NJ)

1983-01-01T23:59:59.000Z

231

Temperature-insensitive phase-matched optical harmonic conversion crystal  

DOE Patents [OSTI]

Temperature-insensitive, phase-matched harmonic frequency conversion of laser light at a preferred wavelength of 1.064 microns can be achieved by use of a crystal of deuterated l-arginine phosphate. The crystal is cut and oriented so that the laser light propagates inside the crystal along one of several required directions, which correspond to a temperature-insensitive, phase-matching locus. The method of measuring and calculating the temperature-insensitive, phase-matching angles can be extended to other fundamental wavelengths and other crystal compositions. 12 figures.

Barker, C.E.; Eimerl, D.; Velsko, S.P.; Roberts, D.

1993-11-23T23:59:59.000Z

232

Temperature-insensitive phase-matched optical harmonic conversion crystal  

DOE Patents [OSTI]

Temperature-insensitive, phase-matched harmomic frequency conversion of laser light at a preferred wavelength of 1.064 microns can be achieved by use of a crystal of deuterated l-arginine phosphate. The crystal is cut and oriented so that the laser light propagates inside the crystal along one of several required directions, which correspond to a temperature-insensitive, phase-matching locus. The method of measuring and calculating the temperature-insensitive, phase-matching angles can be extended to other fundamental wavelengths and other crystal compositions.

Barker, Charles E. (Sunnyvale, CA); Eimerl, David (Livermore, CA); Velsko, Stephan P. (Livermore, CA); Roberts, David (Sagamore Hills, OH)

1993-01-01T23:59:59.000Z

233

Surface Treatment And Protection Method For Cadium Zinc Telluride Crystals  

DOE Patents [OSTI]

A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NH4F and 10 w/o H2O2 in water.

Wright, Gomez W. (Nashville, TN); James, Ralph B. (Livermore, CA); Burger, Arnold (Nashville, TN); Chinn, Douglas A. (Livermore, CA)

2006-02-21T23:59:59.000Z

234

Surface treatment and protection method for cadmium zinc telluride crystals  

DOE Patents [OSTI]

A method for treatment of the surface of a CdZnTe (CZT) crystal that provides a native dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals. A two step process is disclosed, etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and after attachment of electrical contacts, passivating the CZT crystal surface with a solution of 10 w/o NH.sub.4 F and 10 w/o H.sub.2 O.sub.2 in water.

Wright, Gomez W. (Nashville, TN); James, Ralph B. (Livermore, CA); Burger, Arnold (Nashville, TN); Chinn, Douglas A. (Livermore, CA)

2003-01-01T23:59:59.000Z

235

A computational investigation of nucleation processes in organic crystals  

E-Print Network [OSTI]

Nucleation processes are ubiquitous in nature and technology. For instance, cloud formation in the atmosphere, the casting of metals, protein crystallization, biomineralization, the production of porous materials, and ...

Beckham, Gregg Tyler

2008-01-01T23:59:59.000Z

236

New Crystal Structures Lift Fog around Protein Folding  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

New Crystal Structures Lift Fog around Protein Folding Print Nature's proteins set a high bar for nanotechnology. Macromolecules forged from peptide chains of amino acids, these...

237

LOW-TEMPERATURE CRYSTALLIZATION OF AMORPHOUS SILICATE IN ASTROPHYSICAL ENVIRONMENTS  

SciTech Connect (OSTI)

We construct a theoretical model for low-temperature crystallization of amorphous silicate grains induced by exothermic chemical reactions. As a first step, the model is applied to the annealing experiments, in which the samples are (1) amorphous silicate grains and (2) amorphous silicate grains covered with an amorphous carbon layer. We derive the activation energies of crystallization for amorphous silicate and amorphous carbon from the analysis of the experiments. Furthermore, we apply the model to the experiment of low-temperature crystallization of an amorphous silicate core covered with an amorphous carbon layer containing reactive molecules. We clarify the conditions of low-temperature crystallization due to exothermic chemical reactions. Next, we formulate the crystallization conditions so as to be applicable to astrophysical environments. We show that the present crystallization mechanism is characterized by two quantities: the stored energy density Q in a grain and the duration of the chemical reactions {tau}. The crystallization conditions are given by Q>Q{sub min} and {tau} < {tau}{sub cool} regardless of details of the reactions and grain structure, where {tau}{sub cool} is the cooling timescale of the grains heated by exothermic reactions, and Q{sub min} is minimum stored energy density determined by the activation energy of crystallization. Our results suggest that silicate crystallization occurs in wider astrophysical conditions than hitherto considered.

Tanaka, Kyoko K.; Yamamoto, Tetsuo [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Kimura, Hiroshi [Center for Planetary Science, Kobe 657-8501 (Japan)

2010-07-01T23:59:59.000Z

238

Insights into the crystal chemistry of Earth materials rendered...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

density between bonded pairs of atoms for a relatively large number of oxide and silicate crystals and siloxane molecules. The distribution of the electron density shows that...

239

Method for the preparation of photochromic insulating crystals  

DOE Patents [OSTI]

A method for preparing reversible-photochromic magnesium oxide (MgO) crystals. Single crystals of MgO doped with both lithium (Li) and nickel (Ni) are grown by a conventional arc fusion method. The as-grown crystals are characterized by an amber coloration. The crystals lose the amber coloration and become photochromic when they are thermochemically reduced by heating at temperatures greater than 1000.degree. K. in a hydrogen atmosphere. Alternate irradiation with UV and visible light result in rejuvenation and bleaching of the amber coloration, respectively.

Abraham, Marvin M. (Oak Ridge, TN); Boldu, Jose L. (Mexico City, MX); Chen, Yok (Oak Ridge, TN); Orera, Victor M. (Zaragosa, ES)

1986-01-01T23:59:59.000Z

240

Journal of Crystal Growth 250 (2003) 499515 Induction time in crystallization of gas hydrates  

E-Print Network [OSTI]

. Kern Abstract The kinetics of the initial stage of crystallization of one-component gas hydrates. Kinetic inhibitors 1. Introduction In natural gas production, both gas and aqu- eous phases are usually is relatively low (less than 1 wt%). In thermodynamic inhibition, the gas­water­hydrate equilibrium curve

Firoozabadi, Abbas

Note: This page contains sample records for the topic "tiny crystals glow" 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

Solution-grown crystals for neutron radiation detectors, and methods of solution growth  

DOE Patents [OSTI]

An organic crystal according to one embodiment includes an organic crystal comprising diphenylacetylene and stilbene or a stilbene derivative, the crystal having physical characteristics of formation from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source. A system according to one embodiment includes an organic crystal comprising diphenylacetylene and stilbene or a stilbene derivative, the crystal having physical characteristics of formation from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source; and a photodetector for detecting the signal response of the organic crystal. Methods of making such crystals are also provided.

Zaitseva, Natalia; Carman, M Leslie; Payne, Steve

2014-10-28T23:59:59.000Z

242

Photonic Crystal Laser-Driven Accelerator Structures  

SciTech Connect (OSTI)

Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

Cowan, Benjamin M.

2007-08-22T23:59:59.000Z

243

Levitated crystals and quasicrystals of metamaterials  

SciTech Connect (OSTI)

New scientific and technological opportunities exist by marrying dusty plasma research with metamaterials. Specifically, by balancing control and self-assembly, certain laboratory plasmas can become a generic levitation platform for novel structure formation and nanomaterial synthesis. We propose to experimentally investigate two dimensional (2D) and three dimensional (3D) levitated structures of metamaterials and their properties. Such structures can self assemble in laboratory plasmas, similar to levitated dust crystals which were discovered in the mid 1990's. Laboratory plasma platform for metamaterial formation eliminates substrates upon which most metamaterials have to be supported. Three types of experiments, with similar setups, are discussed here. Levitated crystal structures of metamaterials using anisotropic microparticles are the most basic of the three. The second experiment examines whether quasicrystals of metamaterials are possible. Quasicrystals, discovered in the 1980's, possess so-called forbidden symmetries according to the conventional crystallography. The proposed experiment could answer many fundamental questions about structural, thermal and dynamical properties of quasicrystals. And finally, how to use nanoparticle coated microparticles to synthesize very long carbon nanotubes is also described. All of the experiments can fit inside a standard International Space Station locker with dimensions of 8-inch x 17-inch X 18-inch. Microgravity environment is deemed essential in particular for large 3D structures and very long carbon nanotube synthesis.

Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Goree, John A [Dept Phys and Astron., University of Iowa

2012-07-25T23:59:59.000Z

244

Diffusion-Driven Crystal Structure Transformation: Synthesis of Heusler Alloy  

E-Print Network [OSTI]

crystal transformation method would be valuable as a general method to fabricate metal-rich silicide nanowires that are otherwise difficult to synthesize. KEYWORDS Metal silicide, nanowire, crystal transformation, magnetic materials, Heusler alloy M etal silicide nanowires (NWs) can have diverse metal

Kim, Bongsoo

245

Reflection of focused beams from opal photonic crystals  

E-Print Network [OSTI]

. Chutinan, "Full Three-Dimensional Photonic Bandgap Crystals at Near-Infrared Wavelengths," Science 289, 604Reflection of focused beams from opal photonic crystals Karri Varis, Marco Mattila Optoelectronics 10-14, D-55099 Mainz, Germany Abstract: We present a robust method for computing the reflection

Jonsson, Fredrik

246

STEADY STATE LIQUID CRYSTAL THERMOGRAPHY AND HEAT TRANSFER MEASUREMENTS ON  

E-Print Network [OSTI]

Chapter V STEADY STATE LIQUID CRYSTAL THERMOGRAPHY AND HEAT TRANSFER MEASUREMENTS ON SURFACES Composite Heat Transfer Surface Liquid Crystal Image Processing Technique V . 4 Experimental Results and Discussion Test Conditions and Data Analysis Application to Endwall Heat Transfer Problem Further Application

Camci, Cengiz

247

InfoCrystal: A visual tool for information retrieval  

E-Print Network [OSTI]

of interest. The InfoCrystal allows users to specify Boolean as well as vector-space queries graphically continuous, multi-variate fields that vary over space and time. Hence, the transformation problem the InfoCrystalTM, that can be used as a visualiza- tion tool as well as a visual query language to help

Spoerri, Anselm

248

Simultaneous SHG of orthogonally polarized fundamentals in single QPM crystals  

E-Print Network [OSTI]

-order parametric nonlinear processes in a single lithium niobate crystal is being undertaken using a new technique cascading interactions can be realized. The use of the higher QPM orders (3rd, 5th or7th) for the type-0, as the respective nonlinear coefficients are dzzz ~27 pm/V and dyyz ~ 4.7 pm/V in lithium niobate crystals. Possible

249

Effectsof ice-crystal structure on halo formation: cirrus cloud  

E-Print Network [OSTI]

Effectsof ice-crystal structure on halo formation: cirrus cloud experimental and ray campaign, four 220halo-producing cirrus clouds were studied jointly from a ground- based polarization lidar of the aircraft, which collecteda total of 84slides byimpaction, preserving the ice crystals for later microscopic

Takano, Yoshihide

250

Electromagnetic space-time crystals. II. Fractal computational approach  

E-Print Network [OSTI]

A fractal approach to numerical analysis of electromagnetic space-time crystals, created by three standing plane harmonic waves with mutually orthogonal phase planes and the same frequency, is presented. Finite models of electromagnetic crystals are introduced, which make possible to obtain various approximate solutions of the Dirac equation. A criterion for evaluating accuracy of these approximate solutions is suggested.

G. N. Borzdov

2014-10-20T23:59:59.000Z

251

How does a thermal binary crystal break under shear?  

E-Print Network [OSTI]

When exposed to strong shearing, the particles in a crystal will rearrange and ultimately, the crystal will break by forming large nonaffine defects. Even for the initial stage of this process, only little effort has been devoted to the understanding of the breaking process on the scale of the individual particle size for thermalized mixed crystals. Here, we explore the shear-induced breaking for an equimolar two-dimensional binary model crystal with a high interaction asymmetry between the two different species such that the initial crystal has an intersecting square sublattice of the two constituents. Using Brownian dynamics computer simulations, we show that the combination of shear and thermal fluctuations leads to a characteristic hierarchical breaking scenario where initially, the more strongly coupled particles are thermally distorted, paving the way for the weakly coupled particles to escape from their cage. This in turn leads to mobile defects which may finally merge, proliferating a cascade of defects, which triggers the final breakage of the crystal. This scenario is in marked contrast to the breakage of one-component crystals close to melting. Moreover, we explore the orientational dependence of the initial shear direction relative to the crystal orientation and compare this to the usual melting scenario without shear. Our results are verifiable in real-space experiments of superparamagnetic colloidal mixtures at a pending air-water interface in an external magnetic field where the shear can be induced by an external laser field.

Tobias Horn; Hartmut Löwen

2014-11-21T23:59:59.000Z

252

Technology Reports Solution Concentration Prediction for Pharmaceutical Crystallization Processes  

E-Print Network [OSTI]

Using Robust Chemometrics and ATR FTIR Spectroscopy Timokleia Togkalidou, Hsien-Hsin Tung,*, Yongkui Sun systems in the presence of impurities and over a wide range of temperature. To our best knowledge in pharmaceutical industry such as crystal size distribution (CSD) and crystal shape of the product pharmaceuticals

Braatz, Richard D.

253

Hydrogen plasma enhanced crystallization of hydrogenated amorphous silicon films  

E-Print Network [OSTI]

Hydrogen plasma enhanced crystallization of hydrogenated amorphous silicon films K. Pangal,a) J. C August 1998; accepted for publication 21 October 1998 We report that a room temperature hydrogen plasma thermal crystallization of amorphous silicon time by a factor of five. Exposure to hydrogen plasma reduces

254

Nexus Energy Center Unveils Energy-Efficient Tiny Home | Department...  

Energy Savers [EERE]

TRES Project has spray-foam insulation, ENERGY STAR qualified windows, and light-emitting diode (LED) lights. Solar panels will eventually be installed as well. Nexus is...

255

Photo of the Week: Tiny Batteries | Department of Energy  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehicles »Exchange VisitorsforDepartmentPOET-DSMCarbonDepartmentThe

256

Electrofuels: Tiny Organisms Making a Big Impact | Department of Energy  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProvedDecember 2005DepartmentDecember 2011 EMAB Meeting -Committee Charter,Electrofuels:

257

Tiny travelers from deep space could assist in healing Fukushima's  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatusButler Tina Butler Tina-Butler.jpg Tina L. P.nuclear scar

258

Imager Spots and Samples Tiny Tumors | Jefferson Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. |Endecaheme c-Type|Iltt: FermiSliSANANov, 1. 2011

259

Measuring Tiny Waves with High Power Particle Beams | Princeton Plasma  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fund LasDubey Mathematica

260

Tamil Nadu Small and Tiny Industries Association TANSTIA | Open Energy  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov Pty LtdSteen,Ltd Jump to: navigation,OpenFlorida: EnergySector

Note: This page contains sample records for the topic "tiny crystals glow" 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

On the Design of Crystallization-Based Separation Processes: Review and Extension  

E-Print Network [OSTI]

flow sheets for separations based on fractional crystallization. A series of rules are derived that may Keywords: fractional crystallization, process design, process synthesis Introduction Crystallization. In spite of the popularity of this operation, exceeded in scope only by distillation processes

Grossmann, Ignacio E.

262

CrystalPlan: an Experiment Planning Tool for Crystallography  

SciTech Connect (OSTI)

Beam time at large user program based x-ray and neutron scattering facilities is in high demand and always at a premium. CrystalPlan, a highly efficient experiment planning software has been developed to maximize the use of available beamtime per sample per experiment. This program can calculate and optimize the data coverage of a crystal in reciprocal space in a single-crystal diffraction time-of- flight experiment. CrystalPlan can help a user build an experiment plan that will acquire the most data possible, with sufficient coverage but limited redundancy, therefore increasing scientific productivity. A user friendly GUI including a 3D viewer, an automated coverage optimizer, and an option to reorient the crystal for the measurement of selected hkls on specific detector positions are among its useful features. A sample use case of the program with the TOPAZ beamline at SNS will be presented.

Zikovsky, Janik L [ORNL; Peterson, Peter F [ORNL; Wang, Xiaoping [ORNL; Frost, Matthew J [ORNL; Hoffmann, Christina [ORNL

2011-01-01T23:59:59.000Z

263

Polymer crystal-melt interfaces and nucleation in polyethylene  

E-Print Network [OSTI]

Kinetic barriers cause polymers to crystallize incompletely, into nanoscale lamellae interleaved with amorphous regions. As a result, crystalline polymers are full of crystal-melt interfaces, which dominate their physical properties. The longstanding theoretical challenge to understand these interfaces has new relevance, because of accumulating evidence that polymer crystals often nucleate via a metastable, partially ordered "rotator" phase. To test this idea requires a theory of the bulk and interfacial free energies of the critical nucleus. We present a new approach to the crystal-melt interface, which represents the amorphous region as a grafted brush of loops in a self-consistent pressure field. We combine this theory with estimates of bulk free energy differences, to calculate nucleation barriers and rates via rotator versus crystal nuclei for polyethylene. We find rotator-phase nucleation is indeed favored throughout the temperature range where nucleation is observed. Our methods can be extended to other polymers.

Scott T. Milner

2010-09-22T23:59:59.000Z

264

Ultraviolet laser beam monitor using radiation responsive crystals  

DOE Patents [OSTI]

An apparatus and method for monitoring an ultraviolet laser beam includes disposing in the path of an ultraviolet laser beam a substantially transparent crystal that will produce a color pattern in response to ultraviolet radiation. The crystal is exposed to the ultraviolet laser beam and a color pattern is produced within the crystal corresponding to the laser beam intensity distribution therein. The crystal is then exposed to visible light, and the color pattern is observed by means of the visible light to determine the characteristics of the laser beam that passed through crystal. In this manner, a perpendicular cross sectional intensity profile and a longitudinal intensity profile of the ultraviolet laser beam may be determined. The observation of the color pattern may be made with forward or back scattered light and may be made with the naked eye or with optical systems such as microscopes and television cameras.

McCann, Michael P. (Oliver Springs, TN); Chen, Chung H. (Knoxville, TN)

1988-01-01T23:59:59.000Z

265

EMPIRICAL MODEL FOR FORMULATION OF CRYSTAL-TOLERANT HLW GLASSES  

SciTech Connect (OSTI)

Historically, high-level waste (HLW) glasses have been formulated with a low liquideus temperature (T{sub L}), or temperature at which the equilibrium fraction of spinel crystals in the melt is below 1 vol % (T{sub 0.01}), nominally below 1050 C. These constraints cannot prevent the accumulation of large spinel crystals in considerably cooler regions ({approx} 850 C) of the glass discharge riser during melter idling and significantly limit the waste loading, which is reflected in a high volume of waste glass, and would result in high capital, production, and disposal costs. A developed empirical model predicts crystal accumulation in the riser of the melter as a function of concentration of spinel-forming components in glass, and thereby provides guidance in formulating crystal-tolerant glasses that would allow high waste loadings by keeping the spinel crystals small and therefore suspended in the glass.

KRUGER AA; MATYAS J; HUCKLEBERRY AR; VIENNA JD; RODRIGUEZ CA

2012-03-07T23:59:59.000Z

266

Macromolecular Crystallization with Microfluidic Free-Interface Diffusion  

SciTech Connect (OSTI)

Fluidigm released the Topaz 1.96 and 4.96 crystallization chips in the fall of 2004. Topaz 1.96 and 4.96 are the latest evolution of Fluidigm's microfluidics crystallization technologies that enable ultra low volume rapid screening for macromolecular crystallization. Topaz 1.96 and 4.96 are similar to each other but represent a major redesign of the Topaz system and have of substantially improved ease of automation and ease of use, improved efficiency and even further reduced amount of material needed. With the release of the new Topaz system, Fluidigm continues to set the standard in low volume crystallization screening which is having an increasing impact in the field of structural genomics, and structural biology more generally. In to the future we are likely to see further optimization and increased utility of the Topaz crystallization system, but we are also likely to see further innovation and the emergence of competing technologies.

Segelke, B

2005-02-24T23:59:59.000Z

267

Studying the magnetic properties of CoSi single crystals  

SciTech Connect (OSTI)

The magnetic properties of CoSi single crystals have been measured in a range of temperatures T = 5.5-450 K and magnetic field strengths H {<=} 11 kOe. A comparison of the results for crystals grown in various laboratories allowed the temperature dependence of magnetic susceptibility {chi}(T) = M(T)/H to be determined for a hypothetical 'ideal' (free of magnetic impurities and defects) CoSi crystal. The susceptibility of this ideal crystal in the entire temperature range exhibits a diamagnetic character. The {chi}(T) value significantly increases in absolute value with decreasing temperature and exhibits saturation at the lowest temperatures studied. For real CoSi crystals of four types, paramagnetic contributions to the susceptibility have been evaluated and nonlinear (with respect to the field) contributions to the magnetization have been separated and taken into account in the calculations of {chi}(T).

Narozhnyi, V. N., E-mail: narozhnyivn@gmail.com; Krasnorussky, V. N. [Russian Academy of Sciences, Vereshchagin Institute for High Pressure Physics (Russian Federation)

2013-05-15T23:59:59.000Z

268

Halide electroadsorption on single crystal surfaces  

SciTech Connect (OSTI)

The structure and phase behavior of halides have been investigated on single crystals of Ag and Au using synchrotron x-ray scattering techniques. The adlayer coverages are potential dependent. For all halides studied the authors found that with increasing potential, at a critical potential, a disordered adlayer transforms into an ordered structure. Often these ordered phases are incommensurate and exhibit potential-dependent lateral separations (electrocompression). The authors have analyzed the electrocompression in terms of a model which includes lateral interactions and partial charge. A continuous compression is not observed for Br on Ag(100). Rather, they find that the adsorption is site-specific (lattice gas) in both the ordered and disordered phases. The coverage increases with increasing potential and at a critical potential the disordered phase transforms to a well-ordered commensurate structure.

Ocko, B.M. [Brookhaven National Lab., Upton, NY (United States). Dept. of Physics; Wandlowski, T. [Univ. of Ulm (Germany). Dept. of Electrochemistry

1997-07-01T23:59:59.000Z

269

Electrochemical system including lamella settler crystallizer  

DOE Patents [OSTI]

A crystallizer which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as will as in other elecrochemical systems requiring separation for phases of different densities.

Maimoni, Arturo (Orinda, CA)

1988-01-01T23:59:59.000Z

270

The Crystal Structure of Human Argonaute2  

SciTech Connect (OSTI)

Argonaute proteins form the functional core of the RNA-induced silencing complexes that mediate RNA silencing in eukaryotes. The 2.3 angstrom resolution crystal structure of human Argonaute2 (Ago2) reveals a bilobed molecule with a central cleft for binding guide and target RNAs. Nucleotides 2 to 6 of a heterogeneous mixture of guide RNAs are positioned in an A-form conformation for base pairing with target messenger RNAs. Between nucleotides 6 and 7, there is a kink that may function in microRNA target recognition or release of sliced RNA products. Tandem tryptophan-binding pockets in the PIWI domain define a likely interaction surface for recruitment of glycine-tryptophan-182 (GW182) or other tryptophan-rich cofactors. These results will enable structure-based approaches for harnessing the untapped therapeutic potential of RNA silencing in humans.

Schirle, Nicole T.; MacRae, Ian J. (Scripps)

2012-07-18T23:59:59.000Z

271

Enhanced photoacoustic detection using photonic crystal substrate  

SciTech Connect (OSTI)

This paper demonstrates the enhanced photoacoustic sensing of surface-bound light absorbing molecules and metal nanoparticles using a one-dimensional photonic crystal (PC) substrate. The PC structure functions as an optical resonator at the wavelength where the analyte absorption is strong. The optical resonance of the PC sensor provides an intensified evanescent field with respect to the excitation light source and results in enhanced optical absorption by surface-immobilized samples. For the analysis of a light absorbing dye deposited on the PC surface, the intensity of photoacoustic signal was enhanced by more than 10-fold in comparison to an un-patterned acrylic substrate. The technique was also applied to detect gold nanorods and exhibited more than 40 times stronger photoacoustic signals. The demonstrated approach represents a potential path towards single molecule absorption spectroscopy with greater performance and inexpensive instrumentation.

Zhao, Yunfei; Liu, Kaiyang [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); McClelland, John [Ames Laboratory-USDOE, Ames, Iowa 50011 (United States); Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (United States); Lu, Meng, E-mail: menglu@iastate.edu [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-04-21T23:59:59.000Z

272

Crystal-Tolerant Glass Approach For Mitigation Of Crystal Accumulation In Continuous Melters Processing Radioactive Waste  

SciTech Connect (OSTI)

High-level radioactive waste melters are projected to operate in an inefficient manner as they are subjected to artificial constraints, such as minimum liquidus temperature (T{sub L}) or maximum equilibrium fraction of crystallinity at a given temperature. These constraints substantially limit waste loading, but were imposed to prevent clogging of the melter with spinel crystals [(Fe, Ni, Mn, Zn)(Fe, Cr){sub 2}O{sub 4}]. In the melter, the glass discharge riser is the most likely location for crystal accumulation during idling because of low glass temperatures, stagnant melts, and small diameter. To address this problem, a series of lab-scale crucible tests were performed with specially formulated glasses to simulate accumulation of spinel in the riser. Thicknesses of accumulated layers were incorporated into empirical model of spinel settling. In addition, T{sub L} of glasses was measured and impact of particle agglomeration on accumulation rate was evaluated. Empirical model predicted well the accumulation of single crystals and/or smallscale agglomerates, but, excessive agglomeration observed in high-Ni-Fe glass resulted in an under-prediction of accumulated layers, which gradually worsen over time as an increased number of agglomerates formed. Accumulation rate of ~14.9 +- 1 nm/s determined for this glass will result in ~26 mm thick layer in 20 days of melter idling.

Kruger, Albert A. [Department of Energy, Office of River Protection, Richland, Washington (United States); Rodriguez, Carmen P. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Lang, Jesse B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Huckleberry, Adam R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Matyas, Josef [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Owen, Antoinette T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

2012-08-28T23:59:59.000Z

273

PLASTIC DEFORMATION OF CRYSTALS: ANALYTICAL AND COMPUTER SIMULATION STUDIES OF DISLOCATION GLIDE  

E-Print Network [OSTI]

in Rate Processes in Plastic Deformation of Materials, J. C.PLASTIC DEFORMATION OF CRYSTALS: ANALYTICAL AND COMPUTERCAPTIONS FIGURES - iii - PLASTIC DEFORMATION OF CRYSTALS:

Altintas, Sabri

2011-01-01T23:59:59.000Z

274

E-Print Network 3.0 - acid single crystals Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Chemistry single crystal X-ray diffraction. Consequently, the crystal structure... and methanol, followed by slow evaporation at room temperature ... Source: de Gispert, Adri...

275

E-Print Network 3.0 - advanced protein crystallization Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

protein crystallization Page: << < 1 2 3 4 5 > >> 1 Using nanoliter plugs in microfluidics to facilitate and understand protein crystallization Summary: Using nanoliter...

276

E-Print Network 3.0 - analyzing crystals experimental Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

University of Wisconsin at Madison Collection: Chemistry 4 Using nanoliter plugs in microfluidics to facilitate and understand protein crystallization Summary: crystallization...

277

Derivation of a three-dimensional phase-field-crystal model for liquid crystals from density functional theory  

E-Print Network [OSTI]

Using a generalized order parameter gradient expansion within density functional theory, we derive a phase-field-crystal model for liquid crystals composed by apolar particles in three spatial dimensions. Both the translational density and the orientational direction and ordering are included as order parameters. Different terms involving gradients in the order parameters in the resulting free energy functional are compared to the macroscopic Ginzburg-Landau approach as well as to the hydrodynamic description for liquid crystals. Our approach provides microscopic expressions for all prefactors in terms of the particle interactions. Our phase-field-crystal model generalizes the conventional phase-field-crystal model of spherical particles to orientational degrees of freedom and can be used as a starting point to explore phase transitions and interfaces for various liquid-crystalline phases.

Raphael Wittkowski; Hartmut Löwen; Helmut R. Brand

2010-07-09T23:59:59.000Z

278

E-Print Network 3.0 - alpha-in2se3 single crystals Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Igneous crystallization Gabbro: Plagioclase MgFe Pyroxene... (Opal, Jasper) Hematite Crystallization via ,,solute ... Source: Browne, Brandon L. - Department of...

279

Single crystal Processing and magnetic properties of gadolinium nickel  

SciTech Connect (OSTI)

GdNi is a rare earth intermetallic material that exhibits very interesting magnetic properties. Spontaneous magnetostriction occurs in GdNi at T{sub C}, on the order of 8000ppm strain along the c-axis and only until very recently the mechanism causing this giant magnetostriction was not understood. In order to learn more about the electronic and magnetic structure of GdNi, single crystals are required for anisotropic magnetic property measurements. Single crystal processing is quite challenging for GdNi though since the rare-earth transition-metal composition yields a very reactive intermetallic compound. Many crystal growth methods are pursued in this study including crucible free methods, precipitation growths, and specially developed Bridgman crucibles. A plasma-sprayed Gd{sub 2}O{sub 3} W-backed Bridgman crucible was found to be the best means of GdNi single crystal processing. With a source of high-quality single crystals, many magnetization measurements were collected to reveal the magnetic structure of GdNi. Heat capacity and the magnetocaloric effect are also measured on a single crystal sample. The result is a thorough report on high quality single crystal processing and the magnetic properties of GdNi.

Shreve, Andrew John [Ames Laboratory

2012-11-02T23:59:59.000Z

280

Solution-grown crystals for neutron radiation detectors, and methods of solution growth  

DOE Patents [OSTI]

A method according to one embodiment includes growing an organic crystal from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source. A system according to one embodiment includes an organic crystal having physical characteristics of formation from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source; and a photodetector for detecting the signal response of the organic crystal. A method according to another embodiment includes growing an organic crystal from solution, the organic crystal being large enough to exhibit a detectable signal response signature for neutrons from a radioactive source. An organic crystal according to another embodiment includes an organic crystal having physical characteristics of formation from solution, the organic crystal exhibiting a signal response signature for neutrons from a radioactive source, wherein the organic crystal has a length of greater than about 1 mm in one dimension.

Zaitseva, Natalia P.; Hull, Giulia; Cherepy, Nerine J.; Payne, Stephen A.; Stoeffl, Wolfgang

2012-06-26T23:59:59.000Z

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


281

Dynamics of crystallization from segregated block copolymer melts  

SciTech Connect (OSTI)

Microphase separation in semicrystalline block copolymers can be driven by two forces: thermodynamic incompatibility between blocks or crystallization of one or more blocks. Prior work has demonstrated that when the block incompatibility is small, crystallization occurs from a single-phase melt and alternating lamellar microdomains result regardless of the copolymer composition. Several experimental studies have examined the time-resolved process of crystallization from single-phase melts. An added complexity in the case of semicrystalline block copolymers which have large block incompatibilities is the possible formation of an ordered melt mesophase; the presence of these microdomains may affect the crystallization process and the resultant morphology. A number of studies have investigated time-resolved crystallization from weakly segregated diblock copolymer melts, concluding that crystallization destroys any pre-existing melt microstructure resulting in a lamellar morphology. We recently reported the statically determined crystallization results for a series of ethylene-block-(3-methyl-1-butene) polymers, which will be referred to as E/MB`s. The composition of each of the polymers in the series was held constant at {approx}26 wt. % E (f{sub E}) block to produce hexagonally packed cylindrical melts, while the molecular weights were altered to obtain varying degrees of incompatibility. Through static scattering measurements, we have clearly shown that a strongly segregated cylindrical melt can confine crystallization to the pre-established microdomains under ordinary processing conditions. In this work, combined synchrotron-based SAXS and WAXS are employed to dynamically follow the microphase separation and crystallization in these materials at both the unit cell and microdomain scales.

Quiram, D.J.; Register, R.A. [Princeton Univ., NJ (United States); Marchand, G.R. [Dow Chemical Co., Plaquemine, LA (United States); Ryan, A.J. [Univ. of Manchester Institute of Science and Technology, MI (United States)

1996-12-31T23:59:59.000Z

282

Lithium niobate single-crystal and photo-functional device  

DOE Patents [OSTI]

Provided are lithium niobate single-crystal that requires a low voltage of not larger than 10 kV/nm for its ferroelectric polarization inversion and of which the polarization can be periodically inverted with accuracy even at such a low voltage, and a photo-functional device comprising the crystal. The crystal has a molar fraction of Li.sub.2 O/(Nb.sub.2 O.sub.5 +Li.sub.2 O) of falling between 0.49 and 0.52. The photo-functional device can convert a laser ray being incident thereon.

Gopalan, Venkatraman (State College, PA); Mitchell, Terrence E. (Los Alamos, NM); Kitamura, Kenji (Tsukuba, JP); Furukawa, Yasunori (Tsukuba, JP)

2001-01-01T23:59:59.000Z

283

Three-Dimensional Photonic Crystal Laser-Driven Accelerator Structures  

SciTech Connect (OSTI)

We discuss simulated photonic crystal structure designs for laser-driven particle acceleration, focusing on three-dimensional planar structures based on the so-called ''woodpile'' lattice. We describe guiding of a speed-of-light accelerating mode by a defect in the photonic crystal lattice and discuss the properties of this mode, including particle beam dynamics and potential coupling methods for the structure. We also discuss possible materials and power sources for this structure and their effects on performance parameters, as well as possible manufacturing techniques and the required tolerances. In addition we describe the computational technique and possible improvements in numerical modeling that would aid development of photonic crystal structures.

Cowan, B.; /SLAC

2006-09-07T23:59:59.000Z

284

Epitaxial electrodeposition of freestanding large area single crystal substrates  

SciTech Connect (OSTI)

The authors report on a method for producing freestanding single crystal metal films over large areas using electrodeposition and selective etching. The method can be turned into an inexpensive continuous process for making long ribbons or a large area of single crystal films. Results from a 5x5 mm{sup 2} Ni single crystal film using electron backscattering pattern pole figures and x-ray diffraction demonstrate that the quality of material produced is equivalent to the initial substrate without annealing or polishing.

Shin, Jae Wook; Standley, Adam; Chason, Eric [Brown University, Box D, Providence, Rhode Island 02912 (United States)

2007-06-25T23:59:59.000Z

285

Optical-diffraction method for determining crystal orientation  

DOE Patents [OSTI]

Disclosed is an optical diffraction technique for characterizing the three-dimensional orientation of a crystal sample. An arbitrary surface of the crystal sample is texture etched so as to generate a pseudo-periodic diffraction grating on the surface. A laser light beam is then directed onto the etched surface, and the reflected light forms a farfield diffraction pattern in reflection. Parameters of the diffraction pattern, such as the geometry and angular dispersion of the diffracted beam are then related to grating shape of the etched surface which is in turn related to crystal orientation. This technique may be used for examining polycrystalline silicon for use in solar cells.

Sopori, B.L.

1982-05-07T23:59:59.000Z

286

An optical surface resonance may render photonic crystals ineffective  

E-Print Network [OSTI]

In this work we identify and study the presence of extremely intense surface resonances that frustrate the coupling of photons into a photonic crystal over crucial energy ranges. The practical utility of photonic crystals demands the capability to exchange photons with the external medium, therefore, it is essential to understand the cause of these surface resonances and a route to their elimination. We demonstrate that by modifying the surface geometry it is possible to tune the optical response or eliminate the resonances to enable full exploitation of the photonic crystal.

F. García-Santamaría; Erik C. Nelson; P. V. Braun

2007-06-28T23:59:59.000Z

287

Generation and manipulation of nonclassical light using photonic crystals  

E-Print Network [OSTI]

Photonic crystal cavities can localize light into nanoscale volumes with high quality factors. This permits a strong interaction between light and matter, which is important for the construction of classical light sources with improved properties (e.g., low threshold lasers) and of nonclassical light sources (such as single and entangled photon sources) that are crucial pieces of hardware of quantum information processing systems. This article will review some of our recent experimental and theoretical results on the interaction between single quantum dots and photonic crystal cavity fields, and on the integration of multiple photonic crystal devices into functional circuits for quantum information processing.

Jelena Vuckovic; Dirk Englund; David Fattal; Edo Waks; Yoshihisa Yamamoto

2005-10-07T23:59:59.000Z

288

Methods of making composite optical devices employing polymer liquid crystal  

DOE Patents [OSTI]

Composite optical devices are disclosed using polymer liquid crystal materials both as optical and adhesive elements. The devices are made by assembling a heated polymer liquid crystal compound, while in a low viscosity form between optically transparent substrates. The molecules of the polymer are oriented, while in the liquid crystalline state and while above the glass transition temperature (T[sub g]) of the polymer, to provide the desired optical effects, such as polarization, and selective reflection. The liquid crystal polymer cements the substrates together to form an assembly providing the composite optical device. 7 figures.

Jacobs, S.D.; Marshall, K.L.; Cerqua, K.A.

1991-10-08T23:59:59.000Z

289

Methods of making composite optical devices employing polymer liquid crystal  

DOE Patents [OSTI]

Composite optical devices using polymer liquid crystal materials both as optical and adhesive elements. The devices are made by assembling a heated polymer liquid crystal compound, while in a low viscosity form between optically transparent substrates. The molecules of the polymer are oriented, while in the liquid crystalline state and while above the glass transition temperature (T.sub.g) of the polymer, to provide the desired optical effects, such as polarization, and selective reflection. The liquid crystal polymer cements the substrates together to form an assembly providing the composite optical device.

Jacobs, Stephen D. (Pittsford, NY); Marshall, Kenneth L. (Henrietta, NY); Cerqua, Kathleen A. (Fairport, NY)

1991-01-01T23:59:59.000Z

290

The crystal structure of {pi}-ErBO{sub 3}: New single-crystal data for an old problem  

SciTech Connect (OSTI)

Single crystals of the orthoborate {pi}-ErBO{sub 3} were synthesized from Er{sub 2}O{sub 3} and B{sub 2}O{sub 3} under high-pressure/high-temperature conditions of 2 GPa and 800 {sup o}C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, with the lattice parameters a=1128.4(2) pm, b=652.6(2) pm, c=954.0(2) pm, and {beta}=112.8(1){sup o} (R{sub 1}=0.0124 and wR{sub 2}=0.0404 for all data). -- graphical abstract: The first satisfying single-crystal structure determination of {pi}-ErBO{sub 3} sheds light on the extensively discussed structure of {pi}-orthoborates. The application of light pressure during the solid state synthesis yielded in high-quality crystals, due to pressure-induced crystallization. Research highlights: {yields} High-quality single crystals of {pi}-ErBO{sub 3} were prepared via high-pressure-induced crystallization. {yields} At least five different space groups for the rare-earth {pi}-orthoborates are reported. {yields} {pi}-ErBO{sub 3} is isotypic to the pseudowollastonite-type CaSiO{sub 3}. {yields} Remaining ambiguities regarding the structure of the rare-earth {pi}-orthoborates are resolved.

Pitscheider, Almut [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Kaindl, Reinhard [Institut fuer Mineralogie und Petrographie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52, A-6020 Innsbruck (Austria); Oeckler, Oliver [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5-13, D-81377 Muenchen (Germany); Huppertz, Hubert, E-mail: Hubert.Huppertz@uibk.ac.a [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria)

2011-01-15T23:59:59.000Z

291

Smectic Liquid Crystals in Random Environments  

E-Print Network [OSTI]

We study smectic liquid crystals in random environments, e.g., aerogel. A low temperature analysis reveals that even arbitrarily weak quenched disorder (i.e., arbitrarily low aerogel density) destroys translational (smectic) order. A harmonic approximation to the elastic energy suggests that there is no ``smectic Bragg glass'' phase in this system: even at zero temperature, it is riddled with dislocation loops induced by the quenched disorder. This result implies the destruction of orientational (nematic) order as well, and that the thermodynamically sharp Nematic-Smectic-A transition is destroyed by disorder, in agreement with recent experimental results. We also show that the anharmonic elastic terms neglected in the above treatment are important (i.e., are ``relevant'' in the renormalization group sense); whether they alter the above conclusions about the smectic Bragg glass, orientational disorder, and the existence of sharp transitions, remains an open question. However, they do not alter our conclusion that translational (smectic) order is always destroyed. In contrast, we expect that weak annealed disorder should have no qualitative effects on the smectic order.

Leo Radzihovsky; John Toner

1999-06-04T23:59:59.000Z

292

Classical crystal formation of dipoles in two dimensions  

E-Print Network [OSTI]

We consider a two-dimensional layer of dipolar particles at zero temperature in the regime of strong dipole moments. Here we can describe the system using classical methods and determine the crystal structure that minimizes the total energy. The dipoles are assumed to be aligned by an external field and we consider different orientations of the dipolar moments with respect to the two-dimensional plane of motion. We observe that when the orientation angle changes away from perpendicular and towards the plane, the crystal structure will change from a hexagonal form to one that has the dipoles sitting in equidistant rows, i.e. a striped configuration. In addition to calculating the crystal unit cell, we also consider the phonon spectrum and the speed of sound. As the orientation changes away from perpendicular the phonon spectrum develops local minima that are a result of the deformation to the crystal structure.

Hansen, K K; Jensen, A S; Zinner, N T

2015-01-01T23:59:59.000Z

293

Materials for freeform fabrication of GHz tunable dielectric photonic crystals.  

SciTech Connect (OSTI)

Photonic crystals are of interest for GHz transmission applications, including rapid switching, GHz filters, and phased-array technology. 3D fabrication by Robocasting enables moldless printing of high solid loading slurries into structures such as the ''woodpile'' structures used to fabricate dielectric photonic band gap crystals. In this work, tunable dielectric materials were developed and printed into woodpile structures via solid freeform fabrication (SFF) toward demonstration of tunable photonic crystals. Barium strontium titanate ceramics possess interesting electrical properties including high permittivity, low loss, and high tunability. This paper discusses the processing route and dielectric characterization of (BaxSr1-XTiO3):MgO ceramic composites, toward fabrication of tunable dielectric photonic band gap crystals.

Niehaus, Michael Keith; Lewis, Jennifer A. (University of Illinois, Urbana, IL); Smay, James Earl; Clem, Paul Gilbert; Lin, Shawn-Yu; Cesarano, Joseph, III (,; ); Carroll, James F.

2003-01-01T23:59:59.000Z

294

Crystal structure of a macrophage migration inhibitory factor...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

parasitic MIF proteins, the crystal structure of the MIF protein from Giardia lamblia (Gl-MIF), the etiological agent responsible for giardiasis, has been determined at 2.30...

295

Optimization of Photodiode Readout of CsI(Tl) Crystals  

E-Print Network [OSTI]

An experimental setup for CsI crystal readout studies and a standard electronic readout chain are introduced and used in order to measure differences in light yield and equivalent noise for different readout schemes (direct and wavelength shifter). The linearity of the system and two possibilities for determination of the equivalent noise energy are discussed. The setup is used to compare temperature and bias voltage dependence of different photodiode types. Thorough studies of different couplings of photodiodes and crystals result in similar values of equivalent noise energy well below the specifications of the TDR for wavelength shifter readout and direct readout with photodiodes glued on a carrier plate made of plexiglass that is in optical contact with the crystal. contact: brose@pktw03.phy.tu-dresden.de The aims of the studies described in this note are a comparison of different readout schemes (wavelength shifter, direct) for large CsI(Tl) crystals with regard to li...

Brose Dahlinger Eckstein; J. Brose; G. Dahlinger; P. Eckstein; K. R. Schubert

1995-01-01T23:59:59.000Z

296

Crystallization process development and spherical agglomerates for pharmaceutical processing applications  

E-Print Network [OSTI]

The control of crystallization steps is essential in the production of many materials in the pharmaceutical, materials, and chemical industries. Additionally, due to increasing costs of research and development, reductions ...

Quon, Justin (Justin Louie)

2013-01-01T23:59:59.000Z

297

Molecular simulation of crystal growth in alkane and polyethylene melts  

E-Print Network [OSTI]

Molecular simulation has become a very powerful tool for understanding the process of polymer crystallization. By using carefully constructed simulations, one can independently observe the two phenomena responsible for ...

Waheed, Numan

2005-01-01T23:59:59.000Z

298

Constitutive modeling of creep of single crystal superalloys  

E-Print Network [OSTI]

of , and oriented single crystal nickel based su- peralloys for a range of temperatures. The predictions of the theory match well with the available experimental data for CMSX-4. The constitutive model is also imple- mented as a User...

Prasad, Sharat Chand

2006-10-30T23:59:59.000Z

299

Novel advancements in nanofabrication for photonic crystal applications  

E-Print Network [OSTI]

The progress of large-area 2D- and 3D-photonic crystals (PCs) at optical and near infra-red frequencies has been limited by fabrication challenges. Periodic nanostructures must be patterned in high-index and crystalline ...

Cheong, Lin Lee

2013-01-01T23:59:59.000Z

300

A machine learning approach to crystal structure prediction  

E-Print Network [OSTI]

This thesis develops a machine learning framework for predicting crystal structure and applies it to binary metallic alloys. As computational materials science turns a promising eye towards design, routine encounters with ...

Fischer, Christopher Carl

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Molecular Dynamics Simulation of Homogeneous Crystal Nucleation in Polyethylene  

E-Print Network [OSTI]

Using a realistic united-atom force field, molecular dynamics simulations were performed to study homogeneous nucleation of the crystal phase at about 30% supercooling from the melts of n-pentacontahectane (C150) and a ...

Yi, Peng

302

Enhancing cholesteric liquid crystal laser performance using a cholesteric reflector  

E-Print Network [OSTI]

laser based on a free- standing film of photo polymerized cholesteric liquid crystal," Appl. Phys. Lett as an optic fiber-based temperature sensor," Appl. Phys. Lett. 85, 2691-2693 (2004). 15. Y. Huang, Y. Zhou

Wu, Shin-Tson

303

Synthesis and physical characterization of thermoelectric single crystals  

E-Print Network [OSTI]

There is much current interest in thermoelectric devices for sustainable energy. This thesis describes a research project on the synthesis and physical characterization of thermoelectric single crystals. 1In?Se?-[delta] ...

Porras Pérez Guerrero, Juan Pablo

2012-01-01T23:59:59.000Z

304

Method for harvesting rare earth barium copper oxide single crystals  

DOE Patents [OSTI]

A method of preparing high temperature superconductor single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals of the high temperature superconductor, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals of the high temperature superconductor on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals melted, allowing the wicking away of the peritectic liquid. 2 figs.

Todt, V.R.; Sengupta, S.; Shi, D.

1996-04-02T23:59:59.000Z

305

Carbon Nanotube-Reinforced Thermotropic Liquid Crystal Polymer Nanocomposites  

E-Print Network [OSTI]

This paper focuses on the fabrication via simple melt blending of thermotropic liquid crystal polyester (TLCP) nanocomposites reinforced with a very small quantity of modified carbon nanotube (CNT) and the unique effects ...

Kim, Jun Young

306

Superconducting Proximity Effect in Single-Crystal Nanowires  

E-Print Network [OSTI]

This dissertation describes experimental studies of the superconducting proximity effect in single-crystal Pb, Sn, and Zn nanowires of lengths up to 60 um, with both ends of the nanowires in contact with macroscopic electrodes that are either...

Liu, Haidong

2010-07-14T23:59:59.000Z

307

Design of polymeric substrates for controlled molecular crystallization  

E-Print Network [OSTI]

It is essential to control crystallization in many areas of science and technology, such as the production of pharmaceuticals, pigments, concrete, semiconductors, as well as the formation of biominerals. In most practical ...

Diao, Ying, Ph.D. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

308

acid dhsa crystals: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to Characterise Micro-swimmers CERN Preprints Summary: We study the behaviour of hydrogen-peroxide-fuelled self-propelled Janus colloids in a 2D colloidal crystal matrix. The...

309

al single crystal: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Low-Leakage Superconducting Tunnel Junctions with a Single-Crystal Al2O3 Barrier* Computer Technologies and...

310

al single crystals: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Low-Leakage Superconducting Tunnel Junctions with a Single-Crystal Al2O3 Barrier* Computer Technologies and...

311

Electro-optical Modulation in Graphene Integrated Photonic Crystal Nanocavities  

E-Print Network [OSTI]

We demonstrate high-contrast electro-optic modulation in a graphene integrated photonic crystal nanocavity, providing a modulation depth of more than 10 dB at telecom wavelengths. This work shows the feasibility of ...

Gan, Xuetao

312

Enhanced photodetection in graphene-integrated photonic crystal cavity  

E-Print Network [OSTI]

We demonstrate the controlled enhancement of photoresponsivity in a graphene photodetector by coupling to slow light modes in a long photonic crystal linear defect cavity. Near the Brillouin zone (BZ) boundary, spectral ...

Shiue, Ren-Jye

313

Healing of defects in a two-dimensional granular crystal  

E-Print Network [OSTI]

Using a macroscopic analog for a two dimensional hexagonal crystal, we perform an experimental investigation of the self-healing properties of circular grain defects with an emphasis on defect orientation. A circular grain ...

Rice, Marie C

2014-01-01T23:59:59.000Z

314

Terahertz Room-Temperature Photonic Crystal Nanocavity Laser  

E-Print Network [OSTI]

We describe an efficient surface-passivated photonic crystal nanocavity laser, demonstrating room-temperature operation with 3-ps total pulse duration (detector response limited) and low-temperature operation with ultra-low-threshold near 9uW.

Dirk Englund; Hatice Altug; Ilya Fushman; Jelena Vuckovic

2007-06-21T23:59:59.000Z

315

Invariant patterns in crystal lattices: Implications for protein folding algorithms  

SciTech Connect (OSTI)

Crystal lattices are infinite periodic graphs that occur naturally in a variety of geometries and which are of fundamental importance in polymer science. Discrete models of protein folding use crystal lattices to define the space of protein conformations. Because various crystal lattices provide discretizations of the same physical phenomenon, it is reasonable to expect that there will exist invariants across lattices related to fundamental properties of the protein folding process. This paper considers whether performance-guaranteed approximability is such an invariant for HP lattice models. The authors define a master approximation algorithm that has provable performance guarantees provided that a specific sublattice exists within a given lattice. They describe a broad class of crystal lattices that are approximable, which further suggests that approximability is a general property of HP lattice models.

HART,WILLIAM E.; ISTRAIL,SORIN

2000-06-01T23:59:59.000Z

316

Coulomb crystal mass spectrometry in a digital ion trap  

E-Print Network [OSTI]

We present a mass spectrometric technique for identifying the masses and relative abundances of Coulomb-crystallized ions held in a linear Paul trap. A digital radiofrequency waveform is employed to generate the trapping potential, as this can be cleanly switched off, and static dipolar fields subsequently applied to the trap electrodes for ion ejection. Excellent detection efficiency is demonstrated for Ca+ and CaF+ ions from bi-component Ca+/CaF+ Coulomb crystals prepared by reaction of Ca+ with CH3F. A quantitative linear relationship is observed between ion number and the corresponding integrated TOF peak, independent of the ionic species. The technique is applicable to a diverse range of multi-component Coulomb crystals - demonstrated here for Ca+/NH3+/NH4+ and Ca+/CaOH+/CaOD+ crystals - and will facilitate the measurement of ion-molecule reaction rates and branching ratios in complicated reaction systems.

Deb, Nabanita; Smith, Alexander D; Keller, Matthias; Rennick, Christopher J; Heazlewood, Brianna R; Softley, Timothy P

2015-01-01T23:59:59.000Z

317

The Gamma Intensity Monitor at the Crystal-Barrel-Experiment  

E-Print Network [OSTI]

This thesis details the motivation, design, construction, and testing of the Gamma Intensity Monitor (GIM) for the Crystal-Barrel-Experiment at the Universität Bonn. The CB-ELSA collaboration studies the baryon excitation ...

McGehee, William R

2008-01-01T23:59:59.000Z

318

atomic resolution crystal: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Crystal structure retrieval by maximum entropy analysis of atomic resolution incoherent images Materials Science Websites...

319

angstrom resolution crystal: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Muller, David A; 10.1103PhysRevB.86.195415 2012-01-01 5 Crystal structure retrieval by maximum entropy analysis of atomic resolution incoherent images Materials Science Websites...

320

LIQUID CRYSTAL THERMOGRAPHY ON THE FLUID SOLID INTERFACE OF ROTATING SYSTEMS  

E-Print Network [OSTI]

= Aluminum c = centrifugal lc = liquid crystal o = aerodynamic wall friction related p = at constant pressu

Camci, Cengiz

Note: This page contains sample records for the topic "tiny crystals glow" 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

X-Ray Production Using Stacked Pyroelectric Crystals Andrew Kovanen, Yaron Danon, Don Gillich  

E-Print Network [OSTI]

X-Ray Production Using Stacked Pyroelectric Crystals Andrew Kovanen, Yaron Danon, Don Gillich crystals spaced apart with opposite z-faces across from each other produced x-rays with an endpoint energy by stacking LiTaO3 crystals. This research also investigates how different materials between crystals affect x-ray

Danon, Yaron

322

Use of a photonic crystal for optical amplifier gain control  

DOE Patents [OSTI]

An optical amplifier having a uniform gain profile uses a photonic crystal to tune the density-of-states of a gain medium so as to modify the light emission rate between atomic states. The density-of-states of the gain medium is tuned by selecting the size, shape, dielectric constant, and spacing of a plurality of microcavity defects in the photonic crystal. The optical amplifier is particularly useful for the regeneration of DWDM signals in long optical fibers.

Lin, Shawn-Yu (Albuquerque, NM); Fleming, James G. (Albuquerque, NM); El-Kady, Ihab (Albuquerque, NM)

2006-07-18T23:59:59.000Z

323

Growth and characterization of lithium yttrium borate single crystals  

SciTech Connect (OSTI)

Single crystals of 0.1% Ce doped Li{sub 6}Y(BO{sub 3}){sub 3} have been grown using the Czochralski technique. The photoluminescence study of these crystals shows a broad emission at ? 420 nm corresponding to Ce{sub 3+} emission from 5d?4f energy levels. The decay profile of this emission shows a fast response of ? 28 ns which is highly desirable for detector applications.

Singh, A. K.; Singh, S. G.; Tyagi, M.; Desai, D. G.; Sen, Shashwati [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai- 400085 (India)

2014-04-24T23:59:59.000Z

324

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-Print Network [OSTI]

In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

Razeghizadeh, Alireza; Lavafpour, Farhad

2015-01-01T23:59:59.000Z

325

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-Print Network [OSTI]

In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour

2015-02-07T23:59:59.000Z

326

Graphlocons: Large dendritic graphene crystals and their electronic properties  

SciTech Connect (OSTI)

Submillimeter dendritic-shaped crystals were synthesized by low pressure vapor chemical vapor deposition inside a copper enclosure. With their sixfold symmetry and fractal-like shape, the resulting crystals resemble snowflakes. The electronic properties of the devices were investigated down to sub-Kelvin temperatures, showing mobilities over 5000 cm{sup 2}/Vs and the quantum Hall effect at 8T. The magnetoresistance also displayed a sharp peak at zero field which we attribute to weak localization.

Massicotte, Mathieu; Yu, Victor; Whiteway, Eric; Hilke, Michael [Department of Physics, McGill University, Montreal (Canada)

2013-12-04T23:59:59.000Z

327

Colour centres and nanostructures on the surface of laser crystals  

SciTech Connect (OSTI)

This paper presents a study of structural and radiationinduced colour centres in the bulk and ordered nanostructures on the surface of doped laser crystals: sapphire, yttrium aluminium garnet and strontium titanate. The influence of thermal annealing, ionising radiation and plasma exposure on the spectroscopic properties of high-purity materials and crystals containing Ti, V and Cr impurities is examined. Colour centres resulting from changes in the electronic state of impurities and plasma-induced surface modification of the crystals are studied by optical, EPR and X-ray spectroscopies, scanning electron microscopy and atomic force microscopy. X-ray line valence shift measurements are used to assess changes in the electronic state of some impurity and host ions in the bulk and on the surface of oxide crystals. Conditions are examined for the formation of one- and two-level arrays of ordered crystallites 10{sup -10} to 10{sup -7} m in size on the surface of crystals doped with irongroup and lanthanoid ions. The spectroscopic properties of the crystals are analysed using ab initio self-consistent field calculations for Me{sup n+} : [O{sup 2-}]{sub k} clusters. (interaction of laser radiation with matter. laser plasma)

Kulagin, N A [Firma SIFA Ukraine - Germany Joint Venture, ul. Shekspira 6-48, 61045 Kharkiv (Ukraine)

2012-11-30T23:59:59.000Z

328

Radioactive contamination of ZnWO4 crystal scintillators  

E-Print Network [OSTI]

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 -- 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopurity level of the ZnWO4 crystal scintillators is briefly addressed.

P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; A. M. Dubovik; S. d'Angelo; E. N. Galashov; B. V. Grinyov; A. Incicchitti; V. V. Kobychev; M. Laubenstein; L. L. Nagornaya; F. Nozzoli; D. V. Poda; R. B. Podviyanuk; O. G. Polischuk; D. Prosperi; V. N. Shlegel; V. I. Tretyak; I. A. Tupitsyna; Ya. V. Vasiliev; Yu. Ya. Vostretsov

2010-09-05T23:59:59.000Z

329

SINGLE CRYSTAL NIOBIUM TUBES FOR PARTICLE COLLIDERS ACCELERATOR CAVITIES  

SciTech Connect (OSTI)

The objective of this research project is to produce single crystal niobium (Nb) tubes for use as particle accelerator cavities for the Fermi laboratory’s International Linear Collider project. Single crystal Nb tubes may have superior performance compared to a polycrystalline tubes because the absence of grain boundaries may permit the use of higher accelerating voltages. In addition, Nb tubes that are subjected to the high temperature, high vacuum crystallization process are very pure and well annealed. Any impurity with a significantly higher vapor pressure than Nb should be decreased by the relatively long exposure at high temperature to the high vacuum environment. After application of the single crystal process, the surfaces of the Nb tubes are bright and shiny, and the tube resembles an electro polished Nb tube. For these reasons, there is interest in single crystal Nb tubes and in a process that will produce single crystal tubes. To convert a polycrystalline niobium tube into a single crystal, the tube is heated to within a few hundred ?C of the melting temperature of niobium, which is 2477 ?C. RF heating is used to rapidly heat the tube in a narrow zone and after reaching the operating temperature, the hot zone is slowly passed along the length of the tube. For crystallization tests with Nb tubes, the traverse rate was in the range of 1-10 cm per hour. All the crystallization tests in this study were performed in a water-cooled, stainless steel chamber under a vacuum of 5 x10-6 torr or better. In earliest tests of the single crystal growth process, the Nb tubes had an OD of 1.9 cm and a wall thickness of 0.15 mm. With these relatively small Nb tubes, the single crystal process was always successful in producing single crystal tubes. In these early tests, the operating temperature was normally maintained at 2200 ?C, and the traverse rate was 5 cm per hour. In the next test series, the Nb tube size was increased to 3.8 cm OD and the wall thickness was increased 0.18 mm and eventually to 0.21 mm. Again, with these larger tubes, single crystal tubes were usually produced by the crystallization process. The power supply was generally operated at full output during these tests, and the traverse rate was 5 cm per hour. In a few tests, the traverse rate was increased to 10 cm per hour, and at the faster traverse rate, single crystal growth was not achieved. In these tests with a faster traverse rate, it was thought that the tube was not heated to a high enough temperature to achieve single crystal growth. In the next series of tests, the tube OD was unchanged at 3.8 cm and the wall thickness was increased to 0.30 mm. The increased wall thickness made it difficult to reach an operating temperature above 2,000 ?C, and although the single crystal process caused a large increase in the crystal grains, no single crystal tubes were produced. It was assumed that the operating temperature in these tests was not high enough to achieve single crystal growth. In FY 2012, a larger power supply was purchased and installed. With the new power supply, temperatures above the melting point of Nb were easily obtained regardless of the tube thickness. A series of crystallization tests was initiated to determine if indeed the operating temperature of the previous tests was too low to achieve single crystal growth. For these tests, the Nb tube OD remained at 3.8 cm and the wall thickness was 0.30 mm. The first test had an operating temperature of 2,000 ?C. and the operating temperature was increased by 50 ?C increments for each successive test. The final test was very near the Nb melting temperature, and indeed, the Nb tube eventually melted in the center of the tube. These tests showed that higher temperatures did yield larger grain sizes if the traverse rate was held constant at 5 cm per hour, but no single crystal tubes were produced even at the highest operating temperature. In addition, slowing the traverse rate to as low as 1 cm per hour did not yield a single crystal tube regardless of operating temperature. At this time, it

MURPHY, JAMES E [University of Nevada, Reno] [University of Nevada, Reno

2013-02-28T23:59:59.000Z

330

Photorefractivity in polymer-stabilized nematic liquid crystals  

SciTech Connect (OSTI)

Polymer-stabilized liquid crystals, consisting of low concentrations of a polymeric electron acceptor, are shown to exhibit significantly enhanced photorefractive properties. The charge generation and transport properties of these composite systems are strongly modified from nematic liquid crystals doped with electron donors and acceptors. The new composites are produced by polymerizing a small quantity of a 1,4:5,8-naphthalenediimide electron acceptor functionalized with an acrylate group in an aligned nematic liquid crystal. Photopolymerization creates an anisotropic gel-like medium in which the liquid crystal is free to reorient in the presence of a space charge field, while maintaining charge trapping sites in the polymerized regions of the material. The presence of these trapping sites results in the observation of longer lived, higher resolution holographic gratings in the polymer-stabilized liquid crystals than observed in nematic liquid crystals alone. These gratings display Bragg regime diffraction. Asymmetric beam coupling, photo-conductivity, and four-wave mixing experiments are performed to characterize the photophysics of these novel materials.

Wiederrecht, G.P. [Argonne National Lab., IL (United States). Chemistry Div.; Wasielewski, M.R. [Argonne National Lab., IL (United States). Chemistry Div.]|[Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry

1998-07-01T23:59:59.000Z

331

Phonons in a one-dimensional microfluidic crystal  

E-Print Network [OSTI]

The development of a general theoretical framework for describing the behaviour of a crystal driven far from equilibrium has proved difficult1. Microfluidic crystals, formed by the introduction of droplets of immiscible fluid into a liquid-filled channel, provide a convenient means to explore and develop models to describe non-equilibrium dynamics2, 3, 4, 5, 6, 7, 8, 9, 10, 11. Owing to the fact that these systems operate at low Reynolds number (Re), in which viscous dissipation of energy dominates inertial effects, vibrations are expected to be over-damped and contribute little to their dynamics12, 13, 14. Against such expectations, we report the emergence of collective normal vibrational modes (equivalent to acoustic 'phonons') in a one-dimensional microfluidic crystal of water-in-oil droplets at Reapprox10-4. These phonons propagate at an ultra-low sound velocity of approx100 mum s-1 and frequencies of a few hertz, exhibit unusual dispersion relations markedly different to those of harmonic crystals, and give rise to a variety of crystal instabilities that could have implications for the design of commercial microfluidic systems. First-principles theory shows that these phonons are an outcome of the symmetry-breaking flow field that induces long-range inter-droplet interactions, similar in nature to those observed in many other systems including dusty plasma crystals15, 16, vortices in superconductors17, 18, active membranes19 and nucleoprotein filaments20.

Tsevi Beatus; Tsvi Tlusty; Roy Bar-Ziv

2010-08-06T23:59:59.000Z

332

Large single domain 123 material produced by seeding with single crystal rare earth barium copper oxide single crystals  

DOE Patents [OSTI]

A method of fabricating bulk YBa.sub.2 Cu.sub.3 O.sub.x where compressed powder oxides and/or carbonates of Y and Ba and Cu present in mole ratios to form YBa.sub.2 Cu.sub.3 O.sub.x are heated in the presence of a Nd.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.y seed crystal to a temperature sufficient to form a liquid phase in the YBa.sub.2 Cu.sub.3 O.sub.x while maintaining the seed crystal solid. The materials are slowly cooled to provide a YBa.sub.2 Cu.sub.3 O.sub.x material having a predetermined number of domains between 1 and 5. Crack-free single domain materials can be formed using either plate shaped seed crystals or cube shaped seed crystals with a pedestal of preferential orientation material.

Todt, Volker (Lemont, IL); Miller, Dean J. (Darien, IL); Shi, Donglu (Oak Park, OH); Sengupta, Suvankar (Columbus, OH)

1998-01-01T23:59:59.000Z

333

Vacancy diffusion in colloidal crystals as determined by dynamical density-functional theory and the phase-field-crystal model  

E-Print Network [OSTI]

A two-dimensional crystal of repulsive dipolar particles is studied in the vicinity of its melting transition by using Brownian dynamics computer simulation, dynamical density functional theory and phase-field crystal modelling. A vacancy is created by taking out a particle from an equilibrated crystal and the relaxation dynamics of the vacancy is followed by monitoring the time-dependent one-particle density. We find that the vacancy is quickly filled up by diffusive hopping of neighbouring particles towards the vacancy center. We examine the temperature dependence of the diffusion constant and find that it decreases with decreasing temperature in the simulations. This trend is reproduced by the dynamical density functional theory. Conversely, the phase field crystal calculations predict the opposite trend. Therefore, the phase-field model needs a temperature-dependent expression for the mobility to predict trends correctly.

Sven van Teeffelen; Cristian Vasile Achim; Hartmut Löwen

2013-02-05T23:59:59.000Z

334

Correlation functions in liquids and crystals : Free energy functional and liquid - crystal transition  

E-Print Network [OSTI]

A free energy functional for a crystal that contains both the symmetry conserved and symmetry broken parts of the direct pair correlation function has been used to investigate the crystallization of fluids in three-dimensions. The symmetry broken part of the direct pair correlation function has been calculated using a series in ascending powers of the order parameters and which contains three- and higher-bodies direct correlation functions of the isotropic phase. It is shown that a very accurate description of freezing transitions for a wide class of potentials is found by considering the first two terms of this series. The results found for freezing parameters including structure of the frozen phase for fluids interacting via the inverse power potential u(r) = \\epsilon (\\sigma/r)^{n} for n ranging from 4 to \\infty are in very good agreement with simulation results. It is found that for n > 6.5 the fluid freezes into a face centred cubic (fcc) structure while for n \\leq 6 the body centred cubic (bcc) structure is preferred. The fluid-bcc-fcc triple point is found to be at 1/n = 0.158 which is in good agreement with simulation result.

Atul S. Bharadwaj; Swarn L. Singh; Yashwant Singh

2013-04-03T23:59:59.000Z

335

Crystal chemistry of thorium nitrates and chromates  

SciTech Connect (OSTI)

The structures and infrared spectra of six novel thorium compounds are reported. Th(NO{sub 3}){sub 2}(OH){sub 2}(H{sub 2}O){sub 2} (1) crystallizes in space group C2/c, a=14.050(1), b=8.992(7), c=5.954(5) A, {beta}=101.014(2){sup o}. K{sub 2}Th(NO{sub 3}){sub 6} (2), P-3, a=13.606(1), c=6.641(6) A. (C{sub 12}H{sub 28}N){sub 2}Th(NO{sub 3}){sub 6} (3), P2{sub 1}/c, a=14.643(4), b=15.772(5), c=22.316(5) A, {beta}=131.01(1){sup o}. KTh(NO{sub 3}){sub 5}(H{sub 2}O){sub 2} (4), P2{sub 1}/c, a=10.070(8), b=12.731(9), c=13.231(8) A, {beta}=128.647(4){sup o}. Th(CrO{sub 4}){sub 2}(H{sub 2}O){sub 2} (5), P2{sub 1}/n, a=12.731(1), b=9.469(8), c=12.972(1) A, {beta}=91.793(2){sup o}. K{sub 2}Th{sub 3}(CrO{sub 4}){sub 7}(H{sub 2}O){sub 10} (6), Ama2, a=19.302(8), b=15.580(6), c=11.318(6) A. The coordination polyhedra about Th in these structures are diverse. Th is coordinated by 9 O atoms in 5 and 6, seven of which are from monodentate (CrO{sub 4}) tetrahedra and two are (H{sub 2}O). The Th in compound 1 is coordinated by ten O atoms, four of which are O atoms of two bidentate (NO{sub 3}) triangles and six of which are (OH) and (H{sub 2}O). In compounds 2, 3 and 4 the Th is coordinate by 12 O atoms. In 2 and 3 there are six bidentate (NO{sub 3}) triangles, and in 4 ten of the O atoms are part of five bidentate (NO{sub 3}) triangles and the others are (H{sub 2}O) groups. The structural units of these compounds consist of a chain of thorium and nitrate polyhedra (1), isolated thorium hexanitrate clusters (2, 3), an isolated thorium pentanitrate dihydrate cluster (4), and a sheet (6) and framework (5) of thorium and chromate polyhedra. These structures illustrate the complexity inherent in the crystal chemistry of Th. - Graphical Abstract: The structures and infrared spectra of four new Th nitrates and two Th chromates are reported. The coordination numbers of the Th cations range from nine to 12 in these compounds. Structural units consist of isolated clusters, chains, sheets and frameworks.

Sigmon, Ginger E. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.ed [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States)

2010-07-15T23:59:59.000Z

336

Bi-crystals and crystal (GL(V ), GL(W)) duality Vladimir I. Danilov and Gleb A. Koshevoy  

E-Print Network [OSTI]

Bi-crystals and crystal (GL(V ), GL(W)) duality Vladimir I. Danilov and Gleb A. Koshevoy May 17 an action of GL(V ) on V W induced by standard action on V . Similarly the action of GL(W) on W gives us an action on V W. These actions of GL(V ) and GL(W) on V W clearly commute with one another, so we have

337

Crystallization, crystal-structure refinement, and IR spectroscopy of a synthetic hexahydroborite analog  

SciTech Connect (OSTI)

The crystal structure of the hexahydroborite analog Ca[B(OH){sub 4}]{sub 2} {center_dot} 2H{sub 2}O (a = 7.9941(3) Angstrom-Sign , b = 6.6321(2) Angstrom-Sign , c = 7.9871(3) Angstrom-Sign , {beta} = 104.166(4) Degree-Sign , V = 410.58(3) Angstrom-Sign {sup 3}, sp. gr. P2/c, Z = 2, {rho}{sub calc} = 1.891 g/cm{sup 3}; Xcalibur S CCD automated diffractometer, 1196 reflections with I > 2{sigma}(I), {lambda}MoK{sub {alpha}}), which was synthesized by the hydrothermal method via the recrystallization of calciborite CaB{sub 2}O{sub 4} (M) in the M - B{sub 2}O{sub 3} - H{sub 2}O system (t = 250 Degree-Sign C and P = 70-80 atm), was refined by the least-squares method with anisotropic displacement parameters (H atoms were located; R{sub 1} = 0.0260). The structure of synthetic hexahydroborite consists of infinite columns running along the c axis. The columns are formed by Ca polyhedra linked together and to [B(OH){sub 4}] orthotetrahedra by sharing edges. Along the two other axes, the translationally equivalent columns are linked only by hydrogen bonds. The presence of a stronger bond between the discrete (Ca-B-O) columns along the shortest (b = 6.6 Angstrom-Sign ) axis accounts for the possibility of the shift of the columns by 1/2T{sub b} and the formation of the second modification of Ca[B(OH){sub 4}]{sub 2} {center_dot} 2H{sub 2}O. The crystals of synthetic hexahydroborite were studied by IR spectroscopy. A crystal-chemical analysis was performed for a series of natural metaborates with the general formula CaB{sub 2}O{sub 4} {center_dot} nH{sub 2}O (CaO: B{sub 2}O{sub 3} = 1: 1, n = 0-6), including calciborite CaB{sub 2}O{sub 4} and hexahydroborite CaB{sub 2}O{sub 4} {center_dot} 6H{sub 2}O as the end members.

Yamnova, N. A., E-mail: natalia-yamnova@yandex.ru; Borovikova, E. Yu.; Dimitrova, O. V. [Moscow State University, Faculty of Geology (Russian Federation)

2011-11-15T23:59:59.000Z

338

Origin of platy calcite crystals in hot-spring deposits in the Kenya Rift Valley  

SciTech Connect (OSTI)

Platy calcite crystals, which have their c axis parallel to their shortest length axis, are common components of travertine deposits found around some hot springs in the Kenya Rift Valley. They are composite crystals formed of numerous paper-thin subcrystals. Individual plates allowed to grow without obstruction develop a hexagonal motif. The Kenyan crystals typically form in hot (>75 C) waters that have a low Ca content (<10 mg/l), a high CO{sub 2} content, and a high rate of CO{sub 2} degassing. At Chemurkeu, aggregates of numerous small platy crystals collectively form lattice crystals that superficially resemble ray crystals. The walls of the lattice crystals are formed of large platy crystals that have their long and intermediate length axes aligned parallel to the plane of the long axis of the lattice crystal. Internally, the lattice crystals are formed of small platy calcite crystals arranged in a boxlike pattern that creates the appearance of a lattice when viewed in thin section. Lattice crystals are highly porous, with each pore being enclosed by platy crystals. At Lorusio, travertines are mainly formed of pseudodentrites that are constructed by numerous small platy crystals attached to a main stem which is a large platy crystal that commonly curves along its long axis. The pseudodentrites are the main construction blocks in ledges and lilypads that form in the vent pool and spring outflow channels, where the water is too hot for microbes other than hyperthermophiles. The platy calcite crystals in the Kenyan travertines are morphologically similar to platy calcite crystals that form as scale in pipes in the geothermal fields of New Zealand and hydrothermal angel wing calcite from the La Fe mine in Mexico. Comparison of the Kenyan and New Zealand crystals indicates that platy calcite crystals form from waters with a low Ca{sup 2+} content and a high CO{sub 3}/Ca ratio due to rapid rates of CO{sub 2} degassing.

Jones, B. [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Earth and Atmospheric Sciences; Renault, R.W. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Dept. of Geological Sciences

1998-09-01T23:59:59.000Z

339

Development of Crystal-Tolerant High-Level Waste Glasses  

SciTech Connect (OSTI)

Twenty five glasses were formulated. They were batched from HLW AZ-101 simulant or raw chemicals and melted and tested with a series of tests to elucidate the effect of spinel-forming components (Ni, Fe, Cr, Mn, and Zn), Al, and noble metals (Rh2O3 and RuO2) on the accumulation rate of spinel crystals in the glass discharge riser of the high-level waste (HLW) melter. In addition, the processing properties of glasses, such as the viscosity and TL, were measured as a function of temperature and composition. Furthermore, the settling of spinel crystals in transparent low-viscosity fluids was studied at room temperature to access the shape factor and hindered settling coefficient of spinel crystals in the Stokes equation. The experimental results suggest that Ni is the most troublesome component of all the studied spinel-forming components producing settling layers of up to 10.5 mm in just 20 days in Ni-rich glasses if noble metals or a higher concentration of Fe was not introduced in the glass. The layer of this thickness can potentially plug the bottom of the riser, preventing glass from being discharged from the melter. The noble metals, Fe, and Al were the components that significantly slowed down or stopped the accumulation of spinel at the bottom. Particles of Rh2O3 and RuO2, hematite and nepheline, acted as nucleation sites significantly increasing the number of crystals and therefore decreasing the average crystal size. The settling rate of ?10-?m crystal size around the settling velocity of crystals was too low to produce thick layers. The experimental data for the thickness of settled layers in the glasses prepared from AZ-101 simulant were used to build a linear empirical model that can predict crystal accumulation in the riser of the melter as a function of concentration of spinel-forming components in glass. The developed model predicts the thicknesses of accumulated layers quite well, R2 = 0.985, and can be become an efficient tool for the formulation of the crystal-tolerant HLW glasses for higher waste loading. A physical modeling effort revealed that the Stokes and Richardson-Zaki equations can be used to adequately predict the accumulation rate of spinel crystals of different sizes and concentrations in the glass discharge riser of HLW melters. The determined shape factor for the glass beads was only 0.73% lower than the theoretical shape factor for a perfect sphere. The shape factor for the spinel crystals matched the theoretically predicted value to within 10% and was smaller than that of the beads, given the larger drag force caused by the larger surface area-to-volume ratio of the octahedral crystals. In the hindered settling experiments, both the glass bead and spinel suspensions were found to follow the predictions of the Richardson-Zaki equation with the exponent n = 3.6 and 2.9 for glass beads and spinel crystals, respectively.

Matyas, Josef; Vienna, John D.; Schaible, Micah J.; Rodriguez, Carmen P.; Crum, Jarrod V.; Arrigoni, Alyssa L.; Tate, Rachel M.

2010-12-17T23:59:59.000Z

340

NMR STUDIES OF LIQUID CRYSTALS AND MOLECULES DISSOLVED IN LIQUID CRYSTAL SOLVENTS  

SciTech Connect (OSTI)

This thesis describes several studies in which nuclear magnetic resonance (nmr) spectroscopy has been used to probe the structure, orientation and dynamics of liquid crystal mesogens and molecules dissolved in liquid crystalline phases. In addition, a modern high field nmr spectrometer is described which has been used to perform such nmr studies. Chapter 1 introduces the quantum mechanical formalisms used throughout this thesis and briefly reviews the fundamentals of nuclear spin physics and pulsed nmr spectroscopy. First the density operator is described and a specific form for the canonical ensemble is derived. Then Clebsch-Gordon coefficients, Wigner rotation matrices, and irreducible tensor operators are reviewed. An expression for the equilibrium (Curie) magnetization is obtained and the linear response of a spin system to a strong pulsed r.f. irradiation is described. Finally, the spin interaction Hamiltonians relevant to this work are reviewed together with their truncated forms. Chapter 2 is a deuterium magnetic resonance study of two 'nom' liquid crystals which possess several low temperature mesomorphic phases. Specifically, deuterium quadrupolar echo spectroscopy is used to determine the orientation of the liquid crystal molecules in smectic phases, the changes in molecular orientation and motion that occur at smectic-smectic phase transitions, and the order of the phase transitions. For both compounds, the phase sequence is determined to be isotropic, nematic, smectic A, smectic C, smectic B{sub A}, smectic B{sub C}, and crystalline. The structure of the smectic A phase is found to be consistent with the well-known model of a two dimensional liquid in which molecules are rapidly rotating about their long axes and oriented at right angles to the plane of the layers. Molecules in the smectic C phase are found to have their long axes tilted with respect to the layer normal, and the tilt angle is temperature dependent, increasing from zero at the smectic A - smectic C transition and reaching a maximum at 9{sup o} at the smectic C - smectic B{sub A} transition. This finding contradicts the results of X-ray diffraction studies which indicate that the tilt angle is 18{sup o} and temperature independent. The smectic B{sub A} - smectic B{sub C} phase transition is observed for the first time, and is found to be first order, a result that contradicts the prediction of a mean theory by McMillian. Chapter 3 is a multiple quantum nmr study of n-hexane oriented in a nematic liquid crystal solvent. The basic three pulse multiple quantum experiment is discussed which enables the observation of transitions for which |{Delta}m|>1, and then the technique of the separation of multiple quantum orders by phase incrementation in the multiple quantum evolution period is reviewed (TPPI). An explicit example of multiple quantum nmr is given by the calculation of the multiple quantum spectrum of an oriented methyl group.

Drobny, G.P.

1982-11-01T23:59:59.000Z

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341

Radioactive contamination of ZnWO4 crystal scintillators  

E-Print Network [OSTI]

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 â?? 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopur...

Belli, P; Cappella, F; Cerulli, R; Danevich, F A; Dubovik, A M; d'Angelo, S; Galashov, E N; Grinyov, B V; Incicchitti, A; Kobychev, V V; Laubenstein, M; Nagornaya, L L; Nozzoli, F; Poda, D V; Podviyanuk, R B; Polischuk, O G; Prosperi, D; Shlegel, V N; Tretyak, V I; Tupitsyna, I A; Vasiliev, Ya V; Vostretsov, Yu Ya

2010-01-01T23:59:59.000Z

342

Evaluation of CZT crystals from the former Soviet Union  

SciTech Connect (OSTI)

Vertical high pressure Bridgman (VHPB) Cd{sub 1{minus}x}Zn{sub x}Te (0.04 < x < 0.24) detector crystals grown in the Ukraine and Russia have been evaluated and compared to US-grown materials. Various analytical techniques were used to study the materials for trace impurities, precipitates, crystallinity, and electrical transport properties. Relatively high concentrations of carbon and trace impurities such as Se, Nd and Si have been detected in the crystals. In most cases, the crystals showed lower resistivity than US-grown CZT. However, recent crystals grown in Russia exhibited better detector performance than those grown in prior years, and good response to an {sup 241}Am radioactive source was found. Electron lifetimes below 1 {micro}s were measured in crystals having significant numbers of micro-defects, compared to lifetimes of 5--15 {micro}s found in spectrometer grade materials produced in the US. Furthermore, the zinc composition along the growth axis showed better homogeneity in comparison with the US material.

H. Hermon; M. Schieber; R. B. James; A. J. Antolak; D. H. Morse; B. Brunett; C. Hackett; E. Tarver; V. Komar; M. S. Goorsky; H. Yoon; N. N. Kolesnikov; J. Toney; T. E. Schlesinger

1998-01-26T23:59:59.000Z

343

Excitation of intense acoustic waves in hexagonal crystals  

SciTech Connect (OSTI)

Resonant excitation of an intense elastic wave using reflection of a pump wave from a free surface of hexagonal crystal is described. A resonance arises in the case of specially chosen propagation geometry where the reflecting boundary slightly deviates from symmetric orientation and the propagation direction of an intense reflected wave is close to that of an exceptional bulk wave, which satisfies the free boundary condition in unperturbed symmetric orientation. It is shown that, in crystals with elastic moduli c{sub 44}>c{sub 66}, a resonance arises when the initial boundary is chosen parallel to the hexagonal axis 6, whereas in crystals characterized by the relation c{sub 44}crystals. Examples of crystals are presented in which the beam intensity can be increased by a factor of 5-10 at sufficiently high frequencies, with beam divergence remaining acceptable.

Alshits, V. I., E-mail: alshits@ns.crys.ras.ru; Bessonov, D. A.; Lyubimov, V. N. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2013-11-15T23:59:59.000Z

344

Skeletal crystals of calcite and trona from hot-spring deposits in Kenya and New Zealand  

SciTech Connect (OSTI)

Skeletal crystals are hollow crystals that develop because their outer walls grow before their cores. The presence of skeletal crystals of calcite (three types--trigonal prisms, hexagonal prisms, and plates) and trona in hot (> 90 C) spring deposits in New Zealand (Waikite Springs and Ohaaki Pool) and Kenya (Lorusio hot springs) shows that they can form in natural sedimentary regimes. Analysis of samples from these deposits shows that this crystal morphology develops under disequilibrium conditions that are unrelated to a specific environmental or diagenetic setting. Skeletal crystals transform into solid crystals when subsequent precipitation fills their hollow cores. In some cases, this may involve precipitation of crystalline material that has a sieve-like texture. In other examples, the skeletal crystal provides a framework upon which other materials can be precipitated. Walls in the skeletal trigonal calcite prisms from Waikite Springs are formed of subcrystals that mimic the shape of the parent crystal. Similarly, plate-like skeletal crystals from Lorusio are formed of densely packed subcrystals that are < 0.5 {micro}m long. Conversely, the walls of the skeletal hexagonal calcite crystals from Ohaaki Pool and the skeletal trona crystals from Lorusio are not formed of subcrystals. Recognition of skeletal crystals is important because they represent growth that follows the reverse pattern of normal growth. Failure to recognize that crystal growth followed the skeletal motif may lead to false interpretations concerning the growth of a crystal.

Jones, B. [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Earth and Atmospheric Sciences; Renaut, R.W. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Dept. of Geological Sciences

1996-01-01T23:59:59.000Z

345

Getting Crystals Your Crystallographer Will Treasure Richard J. Staples 03/09/2005 1 X-Ray Crystallography Laboratory  

E-Print Network [OSTI]

. What information do we get? A crystal structure provides positive identification of a single crystal to be able to perform these analysis. The positive identification of the compound leaves no interpretation material, solvents? What do we grow the crystals in? Other concerns · Crystal Growth · Crystallization

Meagher, Mary

346

Novel variational approach for photonic crystal slab mode calculation  

E-Print Network [OSTI]

We propose a new method based on variational principle for analysis of photonic crystal (PC) slabs. Most of the methods used today treat PC slab as a three-dimensional (3D) crystal and this makes them very time and/or memory consuming. In this method we use Bloch theorem to expand the field on infinite plane waves which their amplitudes depend on the component perpendicular to the slab surface. By approximating these amplitudes with appropriate functions, we can find modes of PC slabs almost as fast as we can find modes of a two-dimensional (2D) crystal. Besides this advantage, we can also calculate radiation modes with this method which is not feasible with 3D Plane Wave Expansion (PWE) method.

Aram, Mohammad Hasan

2015-01-01T23:59:59.000Z

347

Atomic- Resolution Crystal Structure of the Antiviral Lectin Scytovirin  

SciTech Connect (OSTI)

The crystal structures of the natural and recombinant antiviral lectin scytovirin (SVN) were solved by single-wavelength anomalous scattering and refined with data extending to 1.3 Angstroms and 1.0 Angstroms resolution, respectively. A molecule of SVN consists of a single chain 95 amino acids long, with an almost perfect sequence repeat that creates two very similar domains (RMS deviation 0.25 Angstroms for 40 pairs of Ca atoms). The crystal structure differs significantly from a previously published NMR structure of the same protein, with the RMS deviations calculated separately for the N- and C-terminal domains of 5.3 Angstroms and 3.7 Angstroms, respectively, and a very different relationship between the two domains. In addition, the disulfide bonding pattern of the crystal structures differs from that described in the previously published mass spectrometry and NMR studies.

Moulaei,T.; Botos, I.; Ziolkowska, N.; Bokesch, H.; Krumpe, L.; McKee, T.; O'Keefe, B.; Dauter, Z.; Wlodawer, A.

2007-01-01T23:59:59.000Z

348

Elastic constants of single crystal Hastelloy X at elevated temperatures  

SciTech Connect (OSTI)

An acoustic time of flight technique is described in detail for measuring the elastic constants of cubic single crystals that allows for the constants to be determined at elevated temperature. Although the overall technique is not new, various aspects of the present work may prove extremely useful to others interested in finding these values, especially for aerospace materials applications. Elastic constants were determined for the nickel based alloy, Hastelloy X from room temperature to 1,000 C. Accurate elastic constants were needed as part of an effort to predict both polycrystal mechanical properties and the nature of grain induced heterogeneous mechanical response. The increased accuracy of the acoustically determined constants resulted in up to a 15% change in the predicted stresses in individual grains. These results indicate that the use of elastic single crystal constants of pure nickel as an approximation for the constants of gas turbine single crystal alloys, which is often done today, is inaccurate.

Canistraro, H.A. [Univ. of Hartford, CT (United States). Dept. of Mechanical and Audio Engineering Technology; Jordan, E.H.; Shi Shixiang [Univ. of Connecticut, Storrs, CT (United States); Favrow, L.H.; Reed, F.A. [United Technologies Research Center, East Hartford, CT (United States)

1998-07-01T23:59:59.000Z

349

An observable for vacancy characterization and diffusion in crystals  

E-Print Network [OSTI]

To locate the position and characterize the dynamics of a vacancy in a crystal, we propose to represent it by the ground state density of a quantum probe quasi-particle for the Hamiltonian associated to the potential energy field generated by the atoms in the sample. In this description, the h^2/2mu coefficient of the kinetic energy term is a tunable parameter controlling the density localization in the regions of relevant minima of the potential energy field. Based on this description, we derive a set of collective variables that we use in rare event simulations to identify some of the vacancy diffusion paths in a 2D crystal. Our simulations reveal, in addition to the simple and expected nearest neighbor hopping path, a collective migration mechanism of the vacancy. This mechanism involves several lattice sites and produces a long range migration of the vacancy. Finally, we also observed a vacancy induced crystal reorientation process.

Pierre-Antoine Geslin; Giovanni Ciccotti; Eric Vanden-Eijnden; Simone Meloni

2012-11-20T23:59:59.000Z

350

Shallow Melt Apparatus for Semicontinuous Czochralski Crystal Growth  

DOE Patents [OSTI]

In a single crystal pulling apparatus for providing a Czochralski crystal growth process, the improvement of a shallow melt crucible (20) to eliminate the necessity supplying a large quantity of feed stock materials that had to be preloaded in a deep crucible to grow a large ingot, comprising a gas tight container a crucible with a deepened periphery (25) to prevent snapping of a shallow melt and reduce turbulent melt convection; source supply means for adding source material to the semiconductor melt; a double barrier (23) to minimize heat transfer between the deepened periphery (25) and the shallow melt in the growth compartment; offset holes (24) in the double barrier (23) to increase melt travel length between the deepened periphery (25) and the shallow growth compartment; and the interface heater/heat sink (22) to control the interface shape and crystal growth rate.

Wang, T.; Ciszek, T. F.

2006-01-10T23:59:59.000Z

351

Radioactive contamination of BaF2 crystal scintillator  

E-Print Network [OSTI]

Barium fluoride (BaF$_2$) crystal scintillators are promising detectors to search for double beta decay processes in $^{130}$Ba ($Q_{2{\\beta}}$ = 2619(3) keV) and $^{132}$Ba ($Q_{2{\\beta}}$ = 844(1) keV). The $^{130}$Ba isotope is of particular interest because of the indications on 2${\\beta}$ decay found in two geochemical experiments. The radioactive contamination of BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 113.4 hours in a low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was estimated as $T_{1/2}$ = 298.8 $\\pm$ 0.8(stat.) $\\pm$ 1.4(syst.) ns by analysis of the events pulse profiles.

O. G. Polischuk; P. Belli; R. Bernabei; F. Cappella; V. Caracciolo; R. Cerulli; A. Di Marco; F. A. Danevich; A. Incicchitti; D. V. Poda; V. I. Tretyak

2013-12-17T23:59:59.000Z

352

Radioactive contamination of BaF2 crystal scintillator  

E-Print Network [OSTI]

Barium fluoride (BaF$_2$) crystal scintillators are promising detectors to search for double beta decay processes in $^{130}$Ba ($Q_{2{\\beta}}$ = 2619(3) keV) and $^{132}$Ba ($Q_{2{\\beta}}$ = 844(1) keV). The $^{130}$Ba isotope is of particular interest because of the indications on 2${\\beta}$ decay found in two geochemical experiments. The radioactive contamination of BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 113.4 hours in a low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was estimated as $T_{1/2}$ = 298.8 $\\pm$ 0.8(stat.) $\\pm$ 1.4(syst.) ns by analysis of the events pulse profiles.

Polischuk, O G; Bernabei, R; Cappella, F; Caracciolo, V; Cerulli, R; Di Marco, A; Danevich, F A; Incicchitti, A; Poda, D V; Tretyak, V I

2013-01-01T23:59:59.000Z

353

Crystal Structure Representations for Machine Learning Models of Formation Energies  

E-Print Network [OSTI]

We introduce and evaluate a set of feature vector representations of crystal structures for machine learning (ML) models of formation energies of solids. ML models of atomization energies of organic molecules have been successful using a Coulomb matrix representation of the molecule. We consider three ways to generalize such representations to periodic systems: (i) a matrix where each element is related to the Ewald sum of the electrostatic interaction between two different atoms in the unit cell repeated over the lattice; (ii) an extended Coulomb-like matrix that takes into account a number of neighboring unit cells; and (iii) an Ansatz that mimics the periodicity and the basic features of the elements in the Ewald sum matrix by using a sine function of the crystal coordinates of the atoms. The representations are compared for a Laplacian kernel with Manhattan norm, trained to reproduce formation energies using a data set of 3938 crystal structures obtained from the Materials Project. For training sets consi...

Faber, Felix; von Lilienfeld, O Anatole; Armiento, Rickard

2015-01-01T23:59:59.000Z

354

Luminescence from Edge Fracture in Shocked Lithium Fluoride Crystals  

SciTech Connect (OSTI)

Light emitted from a [100] lithium fluoride crystal was characterized under shock wave compression to 28GPa followed by complete stress release at the edges. The light was examined using time-gated optical spectrometry and imaging, time-resolved optical emission measurements, and hydrodynamic modeling. The shock arrival at the circumference of the crystal was delayed relative to the center so that the two regions could be studied at different times. The majority of the light emission originated when the shock waves released at the circumference of the crystal. Unlike previously reported results for shocked lithium fluoride, we found that the light spectrum is not strictly broad band, but has spectral lines associated with atomic lithium in addition to a broad band background. Also, the emission spectrum depends strongly on the gas surrounding the sample. Based on our observations, the line emission appears to be related to fracture of the lithium fluoride crystal from the shock wave releasing at the edges. Experimenters frequently utilize lithium fluoride crystals as transparent windows for observing shock compressed samples. Because of the experimental geometries used, the shock wave in such cases often reaches the circumference of the window at nearly the same moment as when it reaches the center of the sample-window interface. Light generated at the circumference could contaminate the measurement at the interface when this light scatters into the observed region. This background light may be reduced or avoided using experimental geometries which delay the arrival of the shock wave at the edges of the crystal.

Turley, W. D. [NSTec; Stevens, G. D. [NSTec; Capelle, G. A. [NSTec; Grover, M. [NSTec; Holtkamp, D. B. [LANL; LaLone, B. M. [NSTec; Veeser, L. R. [NSTec, LANL

2013-04-01T23:59:59.000Z

355

The crystal chemistry of four thorium sulfates  

SciTech Connect (OSTI)

Four thorium sulfate compounds have been synthesized and characterized. [Th(SO{sub 4}){sub 2}(H{sub 2}O){sub 7}].2H{sub 2}O (ThS1) crystallizes in space group P2{sub 1}/m, a=7.2488(4), b=12.1798(7), c=8.0625(5) A, {beta}=98.245(1){sup o}; Na{sub 10}[Th{sub 2}(SO{sub 4}){sub 9}(H{sub 2}O){sub 2}].3H{sub 2}O (ThS2), Pna2{sub 1}, a=17.842(2), b=6.9317(8), c=27.550(3) A; Na{sub 2}[Th{sub 2}(SO{sub 4}){sub 5}(H{sub 2}O){sub 3}].H{sub 2}O (ThS3), C2/c, a=16.639(2), b=9.081(1), c=25.078(3) A, {beta}= 95.322(2){sup o}; [Th{sub 4}(SO{sub 4}){sub 7}(OH){sub 2}(H{sub 2}O){sub 6}].2H{sub 2}O (ThS4), Pnma, a=18.2127(9), b=11.1669(5), c=14.4705(7) A. In all cases the Th cations are coordinated by nine O atoms corresponding to SO{sub 4} tetrahedra, OH groups, and H{sub 2}O groups. The structural unit of ThS1 is an isolated cluster consisting of a single Th polyhedron with two monodentate SO{sub 4} tetrahedra and seven H{sub 2}O groups. A double-wide Th sulfate chain is the basis of ThS2. The structures of ThS3 and ThS4 are frameworks of Th polyhedra and sulfate tetrahedra, and each contains channels that extend through the framework. One of the Th cations in ThS3 is coordinated by a bidentate SO{sub 4} tetrahedron, and ThS4 is unusual in the presence of a pair of Th cations that share a polyhedral face. - Graphical abstract: The structures of four hydrous thorium sulfates are reported that have structural units consisting of finite clusters, chains, and frameworks. Highlights: > Four hydrous thorium sulfates have structural units consisting of finite clusters, chains, and frameworks. > In each the Th cations are coordinated by nine O atoms from SO{sub 4} tetrahedra, OH groups, and H{sub 2}O groups. > The details of the linkages of ThO{sub 9} polyhedra and sulfate tetrahedra vary considerably in these structures.

Albrecht, Amanda J.; Sigmon, Ginger E.; Moore-Shay, Laura; Wei, Rebecca; Dawes, Colleen; Szymanowski, Jennifer [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.edu [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States)

2011-07-15T23:59:59.000Z

356

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents [OSTI]

A method is disclosed for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N[sub 2] is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation. 7 figs.

Kuzay, T.M.

1992-06-23T23:59:59.000Z

357

Visualization of stacking faults in fcc crystals in plastic deformations  

E-Print Network [OSTI]

Using molecular dynamics simulation, we investigate the dynamics of stacking faults in fcc crystals in uniaxial stretching in a Lennard-Jones binary mixture composed of 4096 particles in three dimensions. We visualize stacking faults using a disorder variable $D_j(t)$ for each particle $j$ constructed from local bond order parameters based on spherical harmonics (Steinhardt order parameters). Also introducing a method of bond breakage, we examine how stacking faults are formed and removed by collective particle motions. These processes are relevant in plasticity of fcc crystals.

Takeshi Kawasaki; Akira Onuki

2011-11-27T23:59:59.000Z

358

Apparatus And Method For Producing Single Crystal Metallic Objects  

DOE Patents [OSTI]

A mold is provided for enabling casting of single crystal metallic articles including a part-defining cavity, a sorter passage positioned vertically beneath and in fluid communication with the part-defining cavity, and a seed cavity positioned vertically beneath and in fluid communication with the sorter passage. The sorter passage includes a shape suitable for encouraging a single crystal structure in solidifying molten metal. Additionally, a portion of the mold between the sorter passage and the part-defining cavity includes a notch for facilitating breakage of a cast article proximate the notch during thermal stress build-up, so as to prevent mold breakage or the inclusion of part defects.

Huang, Shyh-Chin (Latham, NY); Gigliotti, Jr., Michael Francis X. (Scotia, NY); Rutkowski, Stephen Francis (Duanesburg, NY); Petterson, Roger John (Fultonville, NY); Svec, Paul Steven (Scotia, NY)

2006-03-14T23:59:59.000Z

359

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents [OSTI]

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N.sub.2 is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.

Kuzay, Tuncer M. (Naperville, IL)

1992-01-01T23:59:59.000Z

360

A micro-structured ion-implanted magnonic crystal  

SciTech Connect (OSTI)

We investigate spin-wave propagation in a microstructured magnonic-crystal waveguide fabricated by localized ion implantation. The irradiation caused a periodic variation in the saturation magnetization along the waveguide. As a consequence, the spin-wave transmission spectrum exhibits a set of frequency bands, where spin-wave propagation is suppressed. A weak modification of the saturation magnetization by 7% is sufficient to decrease the spin-wave transmission in the band gaps by a factor of 10. These results evidence the applicability of localized ion implantation for the fabrication of efficient micron- and nano-sized magnonic crystals for magnon spintronic applications.

Obry, Bjoern; Pirro, Philipp; Chumak, Andrii V.; Ciubotaru, Florin; Serga, Alexander A.; Hillebrands, Burkard [Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany)] [Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany); Braecher, Thomas [Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany) [Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany); Graduate School Materials Science in Mainz, D-67663 Kaiserslautern (Germany); Osten, Julia; Fassbender, Juergen [Institut fuer Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf, D-01328 Dresden, Germany and Technische Universitaet Dresden, D-01062 Dresden (Germany)] [Institut fuer Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf, D-01328 Dresden, Germany and Technische Universitaet Dresden, D-01062 Dresden (Germany)

2013-05-20T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" from the National Library of EnergyBeta (NLEBeta).
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361

Schottky and other electrical phenomena in polyethylene crystals  

E-Print Network [OSTI]

polarities anti scale factors INT RODU C T ION Assuming that the prcdornin" nt nzcchanism of electronic con- duction oi n:ic roscopic crystal s ol polyethylene is Schoftky emission, Schottky plot. . ; of this concluction should shove pc riodic deviations...&hiskcr electrode. His I ? V curves for the crystals shov cd ciia raut eristic s similar to those of junction diodes except I'or thc appearance of a. negative resist- ance region at so&no value of applied potential. He suggested a model based on two effects...

Stoltz, Richard Joseph

2012-06-07T23:59:59.000Z

362

Equilibrium configurations of nematic liquid crystals on a torus  

E-Print Network [OSTI]

The topology and the geometry of a surface play a fundamental role in determining the equilibrium configurations of thin films of liquid crystals. We propose here a theoretical analysis of a recently introduced surface Frank energy, in the case of two-dimensional nematic liquid crystals coating a toroidal particle. Our aim is to show how a different modeling of the effect of extrinsic curvature acts as a selection principle among equilibria of the classical energy, and how new configurations emerge. In particular, our analysis predicts the existence of new stable equilibria with complex windings.

Antonio Segatti; Michael Snarski; Marco Veneroni

2014-06-13T23:59:59.000Z

363

Process analysis of margarine and tablespread crystallization operations  

E-Print Network [OSTI]

pumped to a agitated holding tank. At this point the material has no time dependency as long as it remains agitated and at the correct temperature (-38'C/100'F), The holding tank receives batches of emulsion and feeds into the processing and packing... the crystallization point for the oil, but it takes a period of time for the crystallization reaction to occur. Cooled emulsion exiting the SSHE enters a secondary unit (SU), which acts as an agitated flow-through tank that provides a resting period for the super...

Garfield, Gary Charles

1990-01-01T23:59:59.000Z

364

Gradient index liquid crystal devices and method of fabrication thereof  

DOE Patents [OSTI]

Laser beam apodizers using cholesteric liquid crystals provides soft edge profile by use of two separate cholesteric liquid crystal mixtures with different selective reflection bands which in an overlap region have a gradient index where reflectivity changes as a function of position. The apodizers can be configured as a one-dimensional beam apod INTRODUCTION The U.S. government has rights in the invention under Contract No. DE-FC03-85DP40200 between the University of Rochester and the Department of Energy.

Lee, J.C.; Jacobs, S.

1991-10-29T23:59:59.000Z

365

Non-polar Flexoelectrooptic Effect in Blue Phase Liquid Crystals  

E-Print Network [OSTI]

Blue phase liquid crystals are not usually considered to exhibit a flexoelectrooptic effect, due to the polar nature of flexoelectric switching and the cubic or amorphous structure of blue phases. Here, we derive the form of the flexoelectric contribution to the Kerr constant of blue phases, and experimentally demonstrate and measure the separate contributions to the Kerr constant arising from flexoelectric and dielectric effects. Hence, a non-polar flexoelectrooptic effect is demonstrated in blue phase liquid crystals, which will have consequences for the engineering of novel blue-phase electrooptic technology.

B. I. Outram; S. J. Elston; F. Castles; M. M. Qasim; H. Coles; H. -Y. Chen; S. -F. Lu

2014-06-12T23:59:59.000Z

366

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

367

Crystal Structure of a Protein Kinase A Complex  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases on &gamma;-Al2O3.WinterCrystal Structure of a ProteinCrystal

368

Electrolysis at an anthracene crystal/aqueous NO sub 3 sup minus solution interface: The role of crystal defects  

SciTech Connect (OSTI)

The electrolysis of a 1 M solution of NaNO{sub 3} by means of an anthracene crystal electrode results in the production of many surface reaction products, including 9-nitroanthracene (9NA), bianthronyl (BA), and anthraquinone (AQ). The production of 9NA and BA have been shown to depend on the square of the current density. This dependence was rationalized by hypothesizing the need for the simultaneous discharge of two carriers at adjoining lattice defect sites. By annealing the crystals, it was found that the efficiency of producing 9NA was reduced by a factor of as much as 6; this supports the hypothesis.

Pope, M.; Mao, B.; Steigman, J.; Geacintov, N.E. (New York Univ., NY (USA))

1990-03-08T23:59:59.000Z

369

Crystallization Kinetics and Excess Free Energy of H2O and D2O...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Crystallization Kinetics and Excess Free Energy of H2O and D2O Nanoscale Films of Amorphous Solid Water. Crystallization Kinetics and Excess Free Energy of H2O and D2O Nanoscale...

370

Feasibility of the Assessment of Cholesterol Crystals in Human Macrophages Using Micro Optical Coherence Tomography  

E-Print Network [OSTI]

The presence of cholesterol crystals is a hallmark of atherosclerosis, but until recently, such crystals have been considered to be passive components of necrotic plaque cores. Recent studies have demonstrated that ...

Kashiwagi, Manabu

371

Photonic crystal surface-emitting lasers enabled by an accidental Dirac point  

DOE Patents [OSTI]

A photonic-crystal surface-emitting laser (PCSEL) includes a gain medium electromagnetically coupled to a photonic crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the photonic crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the photonic crystal's band structure (e.g., by changing the photonic crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the photonic crystal's mode spacing by orders of magnitudes and reduces or eliminates the photonic crystal's distributed in-plane feedback. Thus, the photonic crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.

Chua, Song Liang; Lu, Ling; Soljacic, Marin

2014-12-02T23:59:59.000Z

372

Monitoring Industrial Pharmaceutical Crystallization Processes Using Acoustic Emission in Pure and Impure Media.  

E-Print Network [OSTI]

Monitoring Industrial Pharmaceutical Crystallization Processes Using Acoustic Emission in Pure processes was almost never evaluated in the field of industrial pharmaceutical crystallization. Few papers. Introduction The pharmaceutical industry is set against strong requests on behalf of both consumers

Paris-Sud XI, Université de

373

INVESTIGATING PHARMACEUTICAL CO-CRYSTALS AS A MEANS TO IMPROVE THE SOLUBILITY OF A DRUG  

E-Print Network [OSTI]

Recently co-crystals have emerged as a potential approach to improve the solubility, dissolution, and bioavailability of active pharmaceutical ingredients (API). Often co-crystal formation is studied in the development stage in order to solve...

Brown, Rebecca Anderson

2012-05-31T23:59:59.000Z

374

Light trapping in thin film solar cells using textured photonic crystal  

DOE Patents [OSTI]

A solar cell includes a photoactive region that receives light. A photonic crystal is coupled to the photoactive region, wherein the photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light.

Yi, Yasha (Somerville, MA); Kimerling, Lionel C. (Concord, MA); Duan, Xiaoman (Amesbury, MA); Zeng, Lirong (Cambridge, MA)

2009-01-27T23:59:59.000Z

375

E-Print Network 3.0 - active photonic crystal Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

vertical radiation using a two-dimensional photonic crystal in a semiconductor light-emitting diode Summary: the active material. The photonic crystal is also used to couple pump...

376

Electromagnetic space-time crystals. III. Dispersion relations for partial solutions  

E-Print Network [OSTI]

Partial solutions of the Dirac equation describing an electron motion in electromagnetic crystals created by plane waves with linear and circular polarizations are treated. It is shown that the electromagnetic crystal formed by circularly polarized waves possesses the spin birefringence.

G. N. Borzdov

2014-10-21T23:59:59.000Z

377

Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demsy and Sajeev John  

E-Print Network [OSTI]

Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demésy and Sajeev://jap.aip.org/about/rights_and_permissions #12;Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demesya

John, Sajeev

378

Pairing of valence electrons as necessary condition for energy minimization in a crystal  

E-Print Network [OSTI]

Pairing of valence electrons can lead to energy minimization of a crystal. It can be proved by use of representation of the valence electrons as plane waves in periodic potential of the crystal.

Dolgopolov Stanislav Olegovich

2014-10-21T23:59:59.000Z

379

CARIBBEAN SEACRUISE IN LUXURY ABOARD CRYSTAL SERENITY BEST MEDIUM  

E-Print Network [OSTI]

CARIBBEAN SEACRUISE IN LUXURY ABOARD CRYSTAL SERENITY WORLD'S BEST MEDIUM CRUISE LINE SIX and brilliantly colored colonial architecture -- this forms the backdrop for our Cruise the Caribbean Sea program at the Caribbean's many offerings, from picturesque lagoons to quaint towns to bustling beaches. Experience

Spence, Harlan Ernest

380

Low temperature magnetic transitions of single crystal HoBi  

SciTech Connect (OSTI)

We present resistivity, specific heat and magnetization measurements in high quality single crystals of HoBi, with a residual resistivity ratio of 126. We find, from the temperature and field dependence of the magnetization, an antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields, into a series of up to five metamagnetic phases.

Fente, A. [Universidad Autonoma de Madrid; Suderow, H. [Universidad Autonoma de Madrid; Vieira, S. [Universidad Autonoma de Madrid; Nemes, N. M. [Instituto de Ciencia de Materiales de Madrid; Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid; Budko, Sergei L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

2013-09-04T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

A MOLECULAR THEORY OF SURFACE TENSION IN NEMATIC LIQUID CRYSTALS  

E-Print Network [OSTI]

1187 A MOLECULAR THEORY OF SURFACE TENSION IN NEMATIC LIQUID CRYSTALS J. D. PARSONS Departamento de 1976, accepte le 10 mai 1976) Résumé. - On calcule la tension superficielle à la surface libre d le plan de la surface; b) il y a un saut de la tension de surface à la transition nématique

Paris-Sud XI, Université de

382

Large area 3D helical photonic crystals A. K. Rauba)  

E-Print Network [OSTI]

.1116/1.3640756] I. INTRODUCTION Chiral, coil-spring-like helical photonic crystal structures are useful for optical the helical lattice periodicity and coil pitch of the 3D PhC. This technique con- sists of a simple two

New Mexico, University of

383

Collective phenomena in defect crystals Reimer Kuhn1,  

E-Print Network [OSTI]

by quantum effects. Both thermal and dynamical properties are considered. The influence of interactions Talence cedex, France Received 25 April 2000 We investigate the effects of interactions between substitutional defects on the properties of defect crystals at low temperatures, where defect motion is governed

Kühn, Reimer

384

Radioactive contamination of SrI2(Eu) crystal scintillator  

E-Print Network [OSTI]

A strontium iodide crystal doped by europium (SrI2(Eu)) was produced by using the Stockbarger growth technique. The crystal was subjected to characterisation that included relative photoelectron output and energy resolution for gamma quanta. The intrinsic radioactivity of SrI2(Eu) crystal scintillator was tested both in scintillation mode and by using ultra-low background HPGe gamma spectrometry deep underground. The response of the SrI2(Eu) detector to alpha particles (alpha/beta ratio and pulse shape) was estimated by analysing the 226Ra trace contamination internal to the crystal. We have found alpha/beta=0.55 and no difference in scintillation decay for alpha particles and gamma quanta. The application of the obtained results in the search for the double electron capture and electron capture with positron emission in 84Sr has been investigated at a level of sensitivity T_1/2 \\sim 10^15-10^16 yr. The results of these studies demonstrate the potentiality of this material for a variety of scintillation appli...

Belli, P; Cerulli, R; Danevich, F A; Galenin, E; Gektin, A; Incicchitti, A; Isaienko, V; Kobychev, V V; Laubenstein, M; Nagorny, S S; Podviyanuk, R B; Tkachenko, S; Tretyak, V I

2011-01-01T23:59:59.000Z

385

Phonon-enhanced crystal growth and lattice healing  

DOE Patents [OSTI]

A system for modifying dislocation distributions in semiconductor materials is provided. The system includes one or more vibrational sources for producing at least one excitation of vibrational mode having phonon frequencies so as to enhance dislocation motion through a crystal lattice.

Buonassisi, Anthony; Bertoni, Mariana; Newman, Bonna

2013-05-28T23:59:59.000Z

386

Photonic Crystal Slot Waveguide Optical Absorption Spectrometer for Highly sensitive  

E-Print Network [OSTI]

months -Remote Monitoring of BTEX hydrocarbons in water needed -Real-time detection and identification of BTEX hydrocarbons in water needed · Sample collection after-the-fact. -Continuous monitoring of water pollutants in water #12;What is Photonic Crystal? · Periodic electromagnetic media comparable to wavelength

Texas at Austin, University of

387

STATISCAL PROCESS CONTROL FOR QUARTZ-CRYSTAL FILTER  

E-Print Network [OSTI]

.07 #12; SPC spc Abstract The title of the thesis for graduation is statiscal process Process Control (SPC),at the process control we use process flow chart ,cause and effect chart process control (spc) Quartz-crystal filter Control chart Process flow chart Control line #12

Wang, Ji

388

Computation of the scattering properties of nonspherical ice crystals  

E-Print Network [OSTI]

This thesis is made up of three parts on the computation of scattering properties of nonspherical particles in the atmosphere. In the first part, a new crystal type-droxtal-is introduced to make a better representation of the shape of small ice...

Zhang, Zhibo

2004-11-15T23:59:59.000Z

389

Glassy and plastic crystals of cyanoadamantane : a Brillouin scattering investigation  

E-Print Network [OSTI]

L-617 « Glassy » and plastic crystals of cyanoadamantane : a Brillouin scattering investigation J. Abstract. 2014 The elastic constants ofcyanoadamantane have been measured in the plastic and « glassy temperature. The temperature dependence of C11 in the plastic phase has been explain- ed by the setting

Paris-Sud XI, Université de

390

NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS  

E-Print Network [OSTI]

#12;NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS BY ALEX TAN KWAN B.S., Stanford) device, the nanocalorimeter, it was possible to investigate the melting of isolated polyethylene (PE, a simple Ni-foil calorimeter, to measure the heat capacity of a thin polyethylene film to verify

Allen, Leslie H.

391

RECENT CRYSTAL STRUCTURE DETERMINATIONS BY NEUTRON DIFFRACTION AT OAK RIDGE  

E-Print Network [OSTI]

469. RECENT CRYSTAL STRUCTURE DETERMINATIONS BY NEUTRON DIFFRACTION AT OAK RIDGE By GEORGE M. BROWN and HENRI A. LEVY, Chemistry Division Oak Ridge National Laboratory (1), Oak Ridge, Tennessee, U. S. A ont été relevées grace au diffractomètre à neutrons d'Oak Ridge position- nant automatiquement les

Paris-Sud XI, Université de

392

Liquid Crystal Optics and Photonics CPHY Assignment 2.  

E-Print Network [OSTI]

Liquid Crystal Optics and Photonics CPHY 74495 Assignment 2. P. Pal¤y-Muhoray Jan. 24, 2014 Due: Feb 4, 2014 1. Read pages 25 - 37 of the text (Guenther, Modern Optics). 2. Read Ch 2., Review of Electricity and Magnetism (http://mpal¤y.lci.kent.edu/optics) 3. Red light with wavelength = 632:8nm

Palffy-Muhoray, Peter

393

AFM CHARACTERIZATION OF LASER INDUCED DAMAGE ON CDZNTE CRYSTAL SURFACES  

SciTech Connect (OSTI)

Semi-conducting CdZnTe (or CZT) crystals can be used in a variety of detector-type applications. CZT shows great promise for use as a gamma radiation spectrometer. However, its performance is adversely affected by point defects, structural and compositional heterogeneities within the crystals, such as twinning, pipes, grain boundaries (polycrystallinity), secondary phases and in some cases, damage caused by external forces. One example is damage that occurs during characterization of the surface by a laser during Raman spectroscopy. Even minimal laser power can cause Te enriched areas on the surface to appear. The Raman spectra resulting from measurements at moderate intensity laser power show large increases in peak intensity that is attributed to Te. Atomic Force Microscopy (AFM) was used to characterize the extent of damage to the CZT crystal surface following exposure to the Raman laser. AFM data reveal localized surface damage in the areas exposed to the Raman laser beam. The degree of surface damage to the crystal is dependent on the laser power, with the most observable damage occurring at high laser power. Moreover, intensity increases in the Te peaks of the Raman spectra are observed even at low laser power with little to no visible damage observed by AFM. AFM results also suggest that exposure to the same amount of laser power yields different amounts of surface damage depending on whether the exposed surface is the Te terminating face or the Cd terminating face of CZT.

Hawkins, S; Lucile Teague, L; Martine Duff, M; Eliel Villa-Aleman, E

2008-06-10T23:59:59.000Z

394

Integration of chalcogenide glassy films and liquid crystals for photoalignment  

E-Print Network [OSTI]

irradiation. Photoinduced anisotropy is successfully used in modern electro optics, first of all, in opticalIntegration of chalcogenide glassy films and liquid crystals for photoalignment and optically , Yu. Reznikov 2 , N. Sheremet 2 , and K. Slyusarenko 2 1 Department of Electro-Optic Engineering

Reznikov, Yuri

395

TRANSMISSION ELECTRON MICROSCOPY OF WEAKLY DEFORMED ALKALI HALIDE CRYSTALS  

E-Print Network [OSTI]

377 TRANSMISSION ELECTRON MICROSCOPY OF WEAKLY DEFORMED ALKALI HALIDE CRYSTALS H. STRUNK Max'importance croissante du durcissement de la solution solide. Abstract. 2014 Transmission electron microscopy (TEM Abstracts 7j66 - 7 I' 1. Introduction. - It is only some years ago that transmission electron microscopy

Boyer, Edmond

396

Microfluidic Generation of Lipidic Mesophases for Membrane Protein Crystallization  

E-Print Network [OSTI]

Microfluidic Generation of Lipidic Mesophases for Membrane Protein Crystallization Sarah L. Perry Mathews AVenue, Urbana, Illinois 61801 ReceiVed March 11, 2009 ABSTRACT: We report on a microfluidic conditions of membrane proteins from a membrane-like phase in sub-20 nL volumes. This integrated microfluidic

Kenis, Paul J. A.

397

Tunable crystals of ultracold polar molecules! Sergey Alyabyshev  

E-Print Network [OSTI]

Jie Cui Marina Li9nskaya Jesus Perez Rios Ping Xiang Funding: Peter Wall Ins9tute for Advanced + Hcomplicating #12;Quantum Simulation! Design simple controllable systems with some of the same properties as complex quantum systems, such as solid-state crystals! #12;"Cold Controlled Chemistry" PCCP 10, 479 (2008

Krems, Roman

398

Crystallization process to reduce NORM-containing waste  

SciTech Connect (OSTI)

This paper describes a process of Naturally Occurring Radioactive Material (NORM) waste reduction for scales, sludges, and soils. The process involves dissolution and fractional crystallization steps that concentrate the radioactive material into a small mass of barite. The concentration of radium in the product, barite, can be increased or decreased. The NORM-containing barite product is suitable for slurry injection into sandstone formations.

Hayden, C.G. [Inst. of Gas Technology, Chicago, IL (United States); Kraemer, T.F.

1995-11-01T23:59:59.000Z

399

Hanford high-level waste evaporator/crystallizer corrosion evaluation  

SciTech Connect (OSTI)

The US Department of Energy, Hanford Site nuclear reservation, located in Southeastern Washington State, is currently home to 61 Mgal of radioactive waste stored in 177 large underground storage tanks. As an intermediate waste volume reduction, the 242-A Evaporator/Crystallizer processes waste solutions from most of the operating laboratories and plants on the Hanford Site. The waste solutions are concentrated in the Evaporator/Crystallizer to a slurry of liquid and crystallized salts. This concentrated slurry is returned to Hanford Site waste tanks at a significantly reduced volume. The Washington State Department of Ecology Dangerous Waste Regulations, WAC 173-393 require that a tank system integrity assessment be completed and maintained on file at the facility for all dangerous waste tank systems. This corrosion evaluation was performed in support of the 242-A Evaporator/Crystallizer Tank System Integrity Assessment Report. This corrosion evaluation provided a comprehensive compatibility study of the component materials and corrosive environments. Materials used for the Evaporator components and piping include austenitic stainless steels (SS) (primarily ASTM A240, Type 304L) and low alloy carbon steels (CS) (primarily ASTM A53 and A106) with polymeric or asbestos gaskets at flanged connections. Building structure and secondary containment is made from ACI 301-72 Structural Concrete for Buildings and coated with a chemically resistant acrylic coating system.

Ohl, P.C.; Carlos, W.C.

1993-10-01T23:59:59.000Z

400

Metric approach for sound propagation in nematic liquid crystals  

E-Print Network [OSTI]

In the eikonal approach, we describe sound propagation near to topological defects of nematic liquid crystal as geodesics of a non-euclidian manifold endowed with an effective metric tensor. The relation between the acoustics of the medium and this geometrical description is given by Fermat's principle. We calculate the ray trajectories and propose a diffraction experiment to retrieve informations about the elastic constants.

E. Pereira; S. Fumeron; F. Moraes

2013-01-21T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Antireflection and Enhanced Absorption in Tapered Silicon Photonic Crystals  

E-Print Network [OSTI]

as applying this structure for solar energy conversion. (a) (b) (c) Figure 1 (a) SEM picture and photograph Optical Society of America OCIS codes: (050.5298) Photonic crystals; (160.4760) Optical properties ; (220 studied as the building blocks to realize functional devices for optical networking, image display, bio

Coldren, Larry A.

402

Electrically controlled modulation in a photonic crystal nanocavity  

E-Print Network [OSTI]

, Elizabeth Edwards1, Tomas Sarmiento1, James S. Harris1, David A. B. Miller1 and Jelena Vuckovi´c1 1. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic crystals: molding the flow of light, 2nd ed

Vuckovic, Jelena

403

E-Print Network 3.0 - aided lateral crystallization Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(FOM) Collection: Mathematics ; Materials Science 7 Photon tunnelling microscopy of polyethylene single crystals Summary: Photon tunnelling microscopy of polyethylene single...

404

Method and apparatus for producing monochromatic radiography with a bent laue crystal  

DOE Patents [OSTI]

A method and apparatus for producing a monochromatic beam. A plurality of beams are generated from a polyenergetic source. The beams are then transmitted through a bent crystal, preferably a bent Laue crystal, having a non-cylindrical shape. A position of the bent crystal is rocked with respect to the polyenergetic source until a plurality of divergent monochromatic beams are emitted from the bent crystal.

Zhong, Zhong (Apt. I 1131 Chaping 700 E. Loop Rd., Stony Brook, NY 11790); Chapman, Leroy Dean (4 Vermont Cir., Bolingbrook, IL 60440); Thomlinson, William C. (32 E. Masem, East Patchogue, NY 11772)

2000-03-14T23:59:59.000Z

405

Role of dye structure in photoinduced reorientation of dye-doped liquid crystals  

E-Print Network [OSTI]

-doped nematic liquid crystals has been measured for a homologous set of dyes belonging to the anthraquinone

Marrucci, Lorenzo

406

Optical surface resonance may render photonic crystals ineffective Florencio Garca-Santamara,* Erik C. Nelson, and Paul V. Braun  

E-Print Network [OSTI]

Optical surface resonance may render photonic crystals ineffective Florencio García crystals and render them ineffective. This surface resonance is dem- onstrated for two different 3D

Braun, Paul

407

Influence of Ba content on grain size and dynamics of crystallization in barium ferrite thin films  

E-Print Network [OSTI]

Influence of Ba content on grain size and dynamics of crystallization in barium ferrite thin films of the crystallization process, which ultimately determines the grain size, were studied in barium ferrite thin films. Rapid thermal annealing was used to crystallize the amorphous as-deposited barium ferrite films

Laughlin, David E.

408

Polymer Photonic Crystals by Self-Assembly From the Resnick Sustainability Institute  

E-Print Network [OSTI]

RESEARCH HIGHLIGHTS Polymer Photonic Crystals by Self-Assembly From the Resnick Sustainability Crystals by Self-Assembly Raymond Weitekamp THE RESNICK SUSTAINABILITY INSTITUTE AT THE CALIFORNIA potential impact. · The unique polymer architecture enables paintable photonic crystals · Blending of two

409

Hypersonic acoustic excitations in binary colloidal crystals: Big versus small hard sphere control  

E-Print Network [OSTI]

Hypersonic acoustic excitations in binary colloidal crystals: Big versus small hard sphere control January 2007 The phononic band structure of two binary colloidal crystals, at hypersonic frequencies of light photonic crystals 2 and sound at hypersonic frequencies.3 The propa- gation of phonons

Schofield, Andrew B.

410

Large pyramid shaped single crystals of BiFeO{sub 3} by solvothermal synthesis method  

SciTech Connect (OSTI)

Synthesis parameters are optimized in order to grow single crystals of multiferroic BiFeO{sub 3}. 2 to 3 mm size pyramid (tetrahedron) shaped single crystals were successfully obtained by solvothermal method. Scanning electron microscopy with EDAX confirmed the phase formation. Raman scattering spectra of bulk BiFeO3 single crystals have been measured which match well with reported spectra.

Sornadurai, D.; Ravindran, T. R.; Paul, V. Thomas; Sastry, V. Sankara [Condensed Matter Physics Division, Materials Science Group, Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Condensed Matter Physics Division, Materials Science Group (India)

2012-06-05T23:59:59.000Z

411

Design and fabrication of photonic crystal thin film photovoltaic cells Guillaume Gomarda,b  

E-Print Network [OSTI]

Design and fabrication of photonic crystal thin film photovoltaic cells Guillaume Gomarda,b , Ounsi of an absorbing planar photonic crystal within a thin film photovoltaic cell. The devices are based on a stack with large areas. Keywords: Photonic crystal, Photovoltaic solar cell, Thin film solar cell, Hydrogenated

Paris-Sud XI, Université de

412

E-Print Network 3.0 - acid phthalate crystals Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Acetaldehyde 250g 6 A 2 Acetyl acetone 4 fl. Oz 6 A 5 Acid oxalic, crystal 1lbs 2 E 1 Acrolein 25ml 6 A 1... Dihydrate, crystals 500g 1 D 1 Cupric Sulfate, fine crystals 1lbs 1 D 1...

413

Spontaneous emission in GaN/InGaN photonic crystal nanopillars  

E-Print Network [OSTI]

. Sigalas, "InGaN/GaN quantum-well heterostructure light-emitting diodes employing photonic crystal, "III-nitride blue and ultraviolet photonic crystal light emitting diodes," Appl. Phys. Lett. 84, 466, and H. Benisty, "Photonic-crystal GaN light-emitting diodes with tailored guided modes distribution

Boyer, Edmond

414

Behavior of the drain leakage current in metal-induced laterally crystallized thin lm transistors  

E-Print Network [OSTI]

Behavior of the drain leakage current in metal-induced laterally crystallized thin ®lm transistors crystallized (MILC) thin ®lm transistors (TFTs) are better than solid phase crystallized (SPC) TFTs in many. � 2000 Elsevier Science Ltd. All rights reserved. Keywords: Thin ®lm transistors; Leakage current

415

Time-Resolved Small-Angle Neutron Scattering Study of Polyethylene Crystallization from Solution  

E-Print Network [OSTI]

Time-Resolved Small-Angle Neutron Scattering Study of Polyethylene Crystallization from Solution-resolved small-angle neutron scattering (TR-SANS), the crystal- lization kinetics of polyethylene from deuterated of polyethylene crystallization from xylene solutions. One unique feature of this experimentation is that both

Wang, Howard "Hao"

416

A Microfluidic Device for Kinetic Optimization of Protein Crystallization and In Situ Structure Determination  

E-Print Network [OSTI]

A Microfluidic Device for Kinetic Optimization of Protein Crystallization and In Situ Structure Received November 10, 2005; E-mail: quake@stanford.edu Recently microfluidic technologies have emerged microfluidic crystallization devices do not allow the post- crystallization addition of cryoprotectant

Quake, Stephen R.

417

Crystal structures of the free and inhibited forms of plasmepsin I (PMI) from Plasmodium falciparum  

E-Print Network [OSTI]

Crystal structures of the free and inhibited forms of plasmepsin I (PMI) from Plasmodium falciparum Crystal structure Enzyme inhibition a b s t r a c t Plasmepsin I (PMI) is one of the four vacuolar pepsin antiparasitic agents. We have now solved crystal struc- tures of the recombinant PMI as apoenzyme and in complex

418

HANFORD MEDIUM-LOW CURIE WASTE PRETREATMENT ALTERNATIVES PROJECT FRACTIONAL CRYSTALLIZATION PILOT SCALE TESTING FINAL REPORT  

SciTech Connect (OSTI)

The Fractional Crystallization Pilot Plant was designed and constructed to demonstrate that fractional crystallization is a viable way to separate the high-level and low-activity radioactive waste streams from retrieved Hanford single-shell tank saltcake. The focus of this report is to review the design, construction, and testing details of the fractional crystallization pilot plant not previously disseminated.

HERTING DL

2008-09-16T23:59:59.000Z

419

Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations  

E-Print Network [OSTI]

Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations of Central Florida, Orlando, Florida, USA The second and fourth harmonics of low frequency electric field-optical modulation; liquid crystal; second and fourth harmonics 1. INTRODUCTION Nematic liquid crystal (LC) has been

Wu, Shin-Tson

420

Low voltage blue-phase liquid crystal displays Linghui Rao,1  

E-Print Network [OSTI]

Low voltage blue-phase liquid crystal displays Linghui Rao,1 Zhibing Ge,1 Shin-Tson Wu,1,a of the emerging blue-phase liquid crystal displays BP-LCDs . Simulation results indicate that the generated-effect-induced isotropic-to-anisotropic transition in blue-phase liquid crystal BPLC 1­6 has potential to become next

Wu, Shin-Tson

Note: This page contains sample records for the topic "tiny crystals glow" 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

Inclusion property of Cs, Sr, and Ba impurities in LiCl crystal formed by layer-melt crystallization  

SciTech Connect (OSTI)

Pyroprocessing is one of the promising technologies enabling the recycling of spent nuclear fuels from a commercial light water reactor (LWR). In general, pyroprocessing uses dry molten salts as electrolytes. In particular, LiCl waste salt after pyroprocessing contains highly radioactive I/II group fission products mainly composed of Cs, Sr, and Ba impurities. Therefore, it is beneficial to reuse LiCl salt in the pyroprocessing as an electrolyte for economic and environmental issues. Herein, to understand the inclusion property of impurities within LiCl crystal, the physical properties such as lattice parameter change, bulk modulus, and substitution enthalpy of a LiCl crystal having 0-6 at% Cs{sup +} or Ba{sup 2+} impurities under existence of 1 at% Sr{sup 2+} impurity were calculated via the first-principles density functional theory. The substitution enthalpy of LiCl crystals having 1 at% Sr{sup 2+} showed slightly decreased value than those without Sr{sup 2+} impurity. Therefore, through the substitution enthalpy calculation, it is expected that impurities will be incorporated within LiCl crystal as co-existed form rather than as a single component form. (authors)

Choi, Jung-Hoon; Cho, Yung-Zun; Lee, Tae-Kyo; Eun, Hee-Chul; Kim, Jun-Hong; Park, Hwan-Seo; Kim, In-Tae; Park, Geun-Il [Nuclear Fuel Cycle Waste Treatment Research Division, Korea Atomic Energy Research Institute, Daejeon, 305-353 (Korea, Republic of)

2013-07-01T23:59:59.000Z

422

Polymorphic single crystal {r_reversible} single crystal transition in K{sub 0.975}Rb{sub 0.025}NO{sub 3}  

SciTech Connect (OSTI)

Polymorphic transformations in K{sub 0.975}Rb{sub 0.025}NO{sub 3} single crystals have been investigated by optical microscopy and X-ray diffraction. The equilibrium temperature between modifications II and III has been determined. It is established that the crystal growth at II {r_reversible} III polymorphic transitions is accompanied by the formation and growth of daughter-modification nuclei in the matrix crystal.

Asadov, Yu. G., E-mail: yusifasadov@rambler.ru; Nasirov, E. V. [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan)

2010-09-15T23:59:59.000Z

423

Synthesis and crystal structure of CuZrTiO{sub 5}-A new crystal structure type  

SciTech Connect (OSTI)

A new compound, CuZrTiO{sub 5}, was synthesized as strongly pleochroic green crystals from the oxides between 995 and 1010 deg. C, 1 atm. Its crystal structure was determined by single crystal XRD, resulting in R (F{sup 2}>2sigma(F{sup 2}))=0.032 and wR (all data)=0.079). CuZrTiO{sub 5} is orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, a=3.5871(3) A, b=6.6968(4) A, c=14.6679(9) A, V=352.35(4) A{sup 3}, Z=4. The structure is topologically similar to In{sub 2}TiO{sub 5} but differs in space group and cation coordination. CuZrTiO{sub 5} has relatively regular TiO{sub 6} polyhedra, but coordination is 7+1 for Zr, and 4+2 for Cu due to the Jahn-Teller effect. Ordering of the long Cu-O bonds causes reduction in symmetry relative to In{sub 2}TiO{sub 5}. Layers of Cu alternate with Ti+Zr on (001), giving rise to a distinct cleavage. Bond valence sums on Ti and Zr are far from ideal, which appears due to the limited ability of this structural topology to avoid close next-nearest neighbour distances. - Graphical abstract: The new compound CuZrTiO{sub 5} is orthorhombic (P2{sub 1}2{sub 1}2{sub 1}), with a=3.5871(3) A, b=6.6968(4) A, c=14.6679(9) A. The structure, determined with single crystal XRD, represents a new crystal structure type that is a slight distortion of that of In{sub 2}TiO{sub 5} but differs in space group and cation coordination.

Troitzsch, Ulrike [Research School of Earth Sciences, Australian National University, Canberra ACT 0200 (Australia); Christy, Andrew G., E-mail: Andrew.Christy@anu.edu.a [Research School of Earth Sciences, Australian National University, Canberra ACT 0200 (Australia); Willis, Anthony C. [Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia); Ellis, David J. [Research School of Earth Sciences, Australian National University, Canberra ACT 0200 (Australia)

2010-03-15T23:59:59.000Z

424

Acquisition of Single Crystal Growth and Characterization Equipment  

SciTech Connect (OSTI)

Final Report for DOE Grant No. DE-FG02-04ER46178 'Acquisition of Single Crystal Growth and Characterization Equipment'. There is growing concern in the condensed matter community that the need for quality crystal growth and materials preparation laboratories is not being met in the United States. It has been suggested that there are too many researchers performing measurements on too few materials. As a result, many user facilities are not being used optimally. The number of proficient crystal growers is too small. In addition, insufficient attention is being paid to the enterprise of finding new and interesting materials, which is the driving force behind much of condensed matter research and, ultimately, technology. While a detailed assessment of this situation is clearly needed, enough evidence of a problem already exists to compel a general consensus that the situation must be addressed promptly. This final report describes the work carried out during the last four years in our group, in which a state-of-the-art single crystal growth and characterization facility was established for the study of novel oxides and intermetallic compounds of rare earth, actinide and transition metal elements. Research emphasis is on the physics of superconducting (SC), magnetic, heavy fermion (HF), non-Fermi liquid (NFL) and other types of strongly correlated electron phenomena in bulk single crystals. Properties of these materials are being studied as a function of concentration of chemical constituents, temperature, pressure, and magnetic field, which provide information about the electronic, lattice, and magnetic excitations at the root of various strongly correlated electron phenomena. Most importantly, the facility makes possible the investigation of material properties that can only be achieved in high quality bulk single crystals, including magnetic and transport phenomena, studies of the effects of disorder, properties in the clean limit, and spectroscopic and scattering studies through efforts with numerous collaborators. These endeavors will assist the effort to explain various outstanding theoretical problems, such as order parameter symmetries and electron-pairing mechanisms in unconventional superconductors, the relationship between superconductivity and magnetic order in certain correlated electron systems, the role of disorder in non-Fermi liquid behavior and unconventional superconductivity, and the nature of interactions between localized and itinerant electrons in these materials. Understanding the mechanisms behind strongly correlated electron behavior has important technological implications.

Maple, M. Brian; Zocco, Diego A.

2008-12-09T23:59:59.000Z

425

Crystal Growth Inhibitors for the Prevention of L-Cystine Kidney Stones Through Molecular Design  

SciTech Connect (OSTI)

Crystallization of L-cystine is a critical step in the pathogenesis of cystine kidney stones. Treatments for this disease are somewhat effective but often lead to adverse side effects. Real-time in situ atomic force microscopy (AFM) reveals that L-cystine dimethylester (L-CDME) and L-cystine methylester (L-CME) dramatically reduce the growth velocity of the six symmetry-equivalent {l_brace}100{r_brace} steps because of specific binding at the crystal surface, which frustrates the attachment of L-cystine molecules. L-CDME and L-CME produce L-cystine crystals with different habits that reveal distinct binding modes at the crystal surfaces. The AFM observations are mirrored by reduced crystal yield and crystal size in the presence of L-CDME and L-CME, collectively suggesting a new pathway to the prevention of L-cystine stones by rational design of crystal growth inhibitors.

Rimer, Jeffrey D.; An, Zhihua; Zhu, Zina; Lee, Michael H.; Goldfarb, David S.; Wesson, Jeffrey A.; Ward, Michael D. (NY Univ.); (MCW)

2010-11-12T23:59:59.000Z

426

Experiment and simulation on one-dimensional plasma photonic crystals  

SciTech Connect (OSTI)

The transmission characteristics of microwaves passing through one-dimensional plasma photonic crystals (PPCs) have been investigated by experiment and simulation. The PPCs were formed by a series of discharge tubes filled with argon at 5?Torr that the plasma density in tubes can be varied by adjusting the discharge current. The transmittance of X-band microwaves through the crystal structure was measured under different discharge currents and geometrical parameters. The finite-different time-domain method was employed to analyze the detailed properties of the microwaves propagation. The results show that there exist bandgaps when the plasma is turned on. The properties of bandgaps depend on the plasma density and the geometrical parameters of the PPCs structure. The PPCs can perform as dynamical band-stop filter to control the transmission of microwaves within a wide frequency range.

Zhang, Lin; Ouyang, Ji-Ting, E-mail: jtouyang@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

2014-10-15T23:59:59.000Z

427

Spontaneous Charging and Crystallization of Water Droplets in Oil  

E-Print Network [OSTI]

We study the spontaneous charging and the crystallization of spherical micron-sized water-droplets dispersed in oil by numerically solving, within a Poisson-Boltzmann theory in the geometry of a spherical cell, for the density profiles of the cations and anions in the system. We take into account screening, ionic Born self-energy differences between oil and water, and partitioning of ions over the two media. We find that the surface charge density of the droplet as induced by the ion partitioning is significantly affected by the droplet curvature and by the finite density of the droplets. We also find that the salt concentration and the dielectric constant regime in which crystallization of the water droplets is predicted is enhanced substantially compared to results based on the planar oil-water interface, thereby improving quantitative agreement with recent experiments.

Joost de Graaf; Jos Zwanikken; Markus Bier; Arjen Baarsma; Yasha Oloumi; Mischa Spelt; Rene van Roij

2008-07-31T23:59:59.000Z

428

Large mode-volume, large beta, photonic crystal laser resonator  

SciTech Connect (OSTI)

We propose an optical resonator formed from the coupling of 13, L2 defects in a triangular-lattice photonic crystal slab. Using a tight-binding formalism, we optimized the coupled-defect cavity design to obtain a resonator with predicted single-mode operation, a mode volume five times that of an L2-cavity mode and a beta factor of 0.39. The results are confirmed using finite-difference time domain simulations. This resonator is very promising for use as a single mode photonic crystal vertical-cavity surface-emitting laser with high saturation output power compared to a laser consisting of one of the single-defect cavities.

Dezfouli, Mohsen Kamandar; Dignam, Marc M. [Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 (Canada)

2014-12-15T23:59:59.000Z

429

How to estimate hardness of crystals on a pocket calculator  

SciTech Connect (OSTI)

A generalization of the semiempirical microscopic model of hardness is presented and applied to currently studied borides, carbides, and nitrides of heavy transition metals. The hardness of OsB, OsC, OsN, PtN, RuC, RuB{sub 2}, ReB{sub 2}, OsB{sub 2}, IrN{sub 2}, PtN{sub 2}, and OsN{sub 2} crystals in various structural phases is predicted. It is found that none of the transition metal crystals is superhard, i.e., with hardness greater than 40 GPa. The presented method provides materials researchers with a practical tool in the search for new hard materials.

Simunek, Antonin [Institute of Physics v.v.i., Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague (Czech Republic)

2007-05-01T23:59:59.000Z

430

Photonic Crystals: Enhancing the Light Output of Scintillation Based Detectors  

E-Print Network [OSTI]

A scintillator is a material which emits light when excited by ionizing radiation. Such materials are used in a diverse range of applications; From high energy particle physics experiments, X-ray security, to nuclear cameras or positron emission tomography. Future high-energy physics (HEP) experiments as well as next generation medical imaging applications are more and more pushing towards better scintillation characteristics. One of the problems in heavy scintillating materials is related to their high index of refraction. As a consequence, most of the scintillation light produced in the bulk material is trapped inside the crystal due to total internal reflection. The same problem also occurs with light emitting diodes (LEDs) and has for a long time been considered as a limiting factor for their overall efficiency. Recent developments in the area of nanophotonics were showing now that those limitations can be overcome by introducing a photonic crystal (PhC) slab at the outcoupling surface of the substrate. P...

Knapitsch, Arno Richard

431

Method to fabricate a tilted logpile photonic crystal  

DOE Patents [OSTI]

A method to fabricate a tilted logpile photonic crystal requires only two lithographic exposures and does not require mask repositioning between exposures. The mask and photoresist-coated substrate are spaced a fixed and constant distance apart using a spacer and the stack is clamped together. The stack is then tilted at a crystallographic symmetry angle (e.g., 45 degrees) relative to the X-ray beam and rotated about the surface normal until the mask is aligned with the X-ray beam. The stack is then rotated in plane by a small stitching angle and exposed to the X-ray beam to pattern the first half of the structure. The stack is then rotated by 180.degree. about the normal and a second exposure patterns the remaining half of the structure. The method can use commercially available DXRL scanner technology and LIGA processes to fabricate large-area, high-quality tilted logpile photonic crystals.

Williams, John D. (Albuquerque, NM); Sweatt, William C. (Albuquerque, NM)

2010-10-26T23:59:59.000Z

432

Ultrafast dynamics of excitons in tetracene single crystals  

SciTech Connect (OSTI)

Ultrafast exciton dynamics in free standing 200 nm thin tetracene single crystals were studied at room temperature by femtosecond transient absorption spectroscopy in the visible spectral range. The complex spectrally overlapping transient absorption traces of single crystals were systematically deconvoluted. From this, the ultrafast dynamics of the ground, excited, and transition states were identified including singlet exciton fission into two triplet excitons. Fission is generated through both, direct fission of higher singlet states S{sub n} on a sub-picosecond timescale, and thermally activated fission of the singlet exciton S{sub 1} on a 40 ps timescale. The high energy Davydov component of the S{sub 1} exciton is proposed to undergo fission on a sub-picoseconds timescale. At high density of triplet excitons their mutual annihilation (triplet-triplet annihilation) occurs on a <10 ps timescale.

Birech, Zephania; Schwoerer, Heinrich, E-mail: heso@sun.ac.za [Laser Research Institute, Stellenbosch University, Stellenbosch 7600 (South Africa)] [Laser Research Institute, Stellenbosch University, Stellenbosch 7600 (South Africa); Schwoerer, Markus [Department of Physics, University of Bayreuth, Bayreuth (Germany)] [Department of Physics, University of Bayreuth, Bayreuth (Germany); Schmeiler, Teresa; Pflaum, Jens [Experimental Physics VI, University of Würzburg and Bavarian Center for Applied Energy Research, Würzburg (Germany)] [Experimental Physics VI, University of Würzburg and Bavarian Center for Applied Energy Research, Würzburg (Germany)

2014-03-21T23:59:59.000Z

433

High-Efficiency Nitride-Based Photonic Crystal Light Sources  

Broader source: Energy.gov [DOE]

The University of California Santa Barbara (UCSB) is maximizing the efficiency of a white LED by enhancing the external quantum efficiency using photonic crystals to extract light that would normally be confined in a conventional structure. Ultimate efficiency can only be achieved by looking at the internal structure of light. To do this, UCSB is focusing on maximizing the light extraction efficiency and total light output from light engines driven by Gallium Nitride (GaN)-based LEDs. The challenge is to engineer large overlap (interaction) between modes and photonic crystals. The project is focused on achieving high extraction efficiency in LEDs, controlled directionality of emitted light, integrated design of vertical device structure, and nanoscale patterning of lateral structure.

434

Origin of electronic transport of lithium phthalocyanine iodine crystal  

SciTech Connect (OSTI)

The electronic structures of Lithium Phthalocyanine Iodine are investigated using density functional theory. Comparing the band structures of several model crystals, the metallic conductivity of highly doped LiPcI{sub x} can be explained by the band of doped iodine. These results reveal that there is a new mechanism for electronic transport of doped organic semiconductors that the dopant band plays the main role.

Koike, Noritake; Oda, Masato; Shinozuka, Yuzo [Department of Materials Science and Chemistry, Wakayama University, 930 Sakaedani, Wakayama (Japan)

2013-12-04T23:59:59.000Z

435

Fabrication and transmission measurements of liquid crystal cells  

E-Print Network [OSTI]

between two transparent conducting glass plates. Because of the anisotropic properties of the liquid crystals, their orientation with respect to the polarization of the incident light can be controlled by applying sui. table voltages to the cell. LC... coeffi- cients of the dye molecules with respect to the polarization of the incident light, the transmission can be controlled with the applica- tion of voltage. With no voltage applied to the cell, the dye molecules are aligned...

Yoon, Dae Won

1984-01-01T23:59:59.000Z

436

Growth and properties of Lithium Salicylate single crystals  

SciTech Connect (OSTI)

An attractive feature of {sup 6}Li containing fluorescence materials that determines their potential application in radiation detection is the capture reaction with slow ({approx}< 100 keV) neutrons: {sup 6}Li + n = {sup 4}He + {sup 3}H + 4.8MeV. The use of {sup 6}Li-salicylate (LiSal, LiC{sub 6}H{sub 5}O{sub 3}) for thermal neutron detection was previously studied in liquid and polycrystalline scintillators. The studies showed that both liquid and polycrystalline LiSal scintillators could be utilized in pulse shape discrimination (PSD) techniques that enable separation of neutrons from the background gamma radiation. However, it was found that the efficiency of neutron detection using LiSal in liquid solutions was severely limited by its low solubility in commonly used organic solvents like, for example, toluene or xylene. Better results were obtained with neutron detectors containing the compound in its crystalline form, such as pressed pellets, or microscopic-scale (7-14 micron) crystals dispersed in various media. The expectation drown from these studies was that further improvement of pulse height, PSD, and efficiency characteristics could be reached with larger and more transparent LiSal crystals, growth of which has not been reported so far. In this paper, we present the first results on growth and characterization of relatively large, a cm-scale size, single crystals of LiSal with good optical quality. The crystals were grown both from aqueous and anhydrous (methanol) media, mainly for neutron detection studies. However, the results on growth and structural characterization may be interesting for other fields where LiSal, together with other alkali metal salicylates, is used for biological, medical, and chemical (as catalyst) applications.

Zaitseva, N; Newby, J; Hull, G; Saw, C; Carman, L; Cherepy, N; Payne, S

2009-02-13T23:59:59.000Z

437

Crystal Structure and Formation Energy of -carbide Using First  

E-Print Network [OSTI]

Crystal Structure and Formation Energy of -carbide Using First Principles CalculationsIntroduction · Martensite (') -carbide -carbide -carbide Cementite () · Silicon promotes the formation of -carbide below-456(2008) 900, 100s 200, 20s 250, 30 s Ms = 302(1.0 wt%Si), 293 (1.7 wt%Si) 1.0wt% Si : No -carbide 1.7wt% Si

Cambridge, University of

438

Photonic Crystal Cavities in Cubic Polytype Silicon Carbide Films  

E-Print Network [OSTI]

We present the design, fabrication, and characterization of high quality factor and small mode volume planar photonic crystal cavities from cubic (3C) thin films (thickness ~ 200 nm) of silicon carbide (SiC) grown epitaxially on a silicon substrate. We demonstrate cavity resonances across the telecommunications band, with wavelengths from 1250 - 1600 nm. Finally, we discuss possible applications in nonlinear optics, optical interconnects, and quantum information science.

Radulaski, Marina; Buckley, Sonia; Rundquist, Armand; Provine, J; Alassaad, Kassem; Ferro, Gabriel; Vu?kovi?, Jelena

2013-01-01T23:59:59.000Z

439

Molecular dynamics simulation of chains mobility in polyethylene crystal  

E-Print Network [OSTI]

The mobility of polymer chains in perfect polyethylene (PE) crystal was calculated as a function of temperature and chain length through Molecular dynamics (MD) in united atom approximation. The results demonstrate that the chain mobility drastically increases in the vicinity of the phase transition from the orthorhombic to quasi-hexagonal phase. In the quasi-hexagonal phase, the chain mobility is almost independent on temperature and inversely proportional to the chain length.

V. I. Sultanov; V. V. Atrazhev; D. V. Dmitriev; S. F. Burlatsky

2014-01-17T23:59:59.000Z

440

Synthesis and Liquid Crystal Phase Transitions of Zirconium Phosphate Disks  

E-Print Network [OSTI]

products. Mostly with flask shape, the particles made up the clay which is abundant in the earth covering our planet. Like graphene, some inorganic layered compounds, such as MoS2, Niobium layered oxide (Niobates), and ?-Zirconium phosphates (?-Zr... discotic liquid crystal systems have been studied, including nature clay suspensions [24], monolayer niobate suspensions [25], and 4 recently graphene oxide suspensions [26], the majority of the works are focused on the I- N transitions. One reason...

Shuai, Min

2013-05-07T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Optical Basicity and Nepheline Crystallization in High Alumina Glasses  

SciTech Connect (OSTI)

The purpose of this study was to find compositions that increase waste loading of high-alumina wastes beyond what is currently acceptable while avoiding crystallization of nepheline (NaAlSiO4) on slow cooling. Nepheline crystallization has been shown to have a large impact on the chemical durability of high-level waste glasses. It was hypothesized that there would be some composition regions where high-alumina would not result in nepheline crystal production, compositions not currently allowed by the nepheline discriminator. Optical basicity (OB) and the nepheline discriminator (ND) are two ways of describing a given complex glass composition. This report presents the theoretical and experimental basis for these models. They are being studied together in a quadrant system as metrics to explore nepheline crystallization and chemical durability as a function of waste glass composition. These metrics were calculated for glasses with existing data and also for theoretical glasses to explore nepheline formation in Quadrant IV (passes OB metric but fails ND metric), where glasses are presumed to have good chemical durability. Several of these compositions were chosen, and glasses were made to fill poorly represented regions in Quadrant IV. To evaluate nepheline formation and chemical durability of these glasses, quantitative X-ray diffraction (XRD) analysis and the Product Consistency Test were conducted. A large amount of quantitative XRD data is collected here, both from new glasses and from glasses of previous studies that had not previously performed quantitative XRD on the phase assemblage. Appendix A critically discusses a large dataset to be considered for future quantitative studies on nepheline formation in glass. Appendix B provides a theoretical justification for choice of the oxide coefficients used to compute the OB criterion for nepheline formation.

Rodriguez, Carmen P.; McCloy, John S.; Schweiger, M. J.; Crum, Jarrod V.; Winschell, Abigail E.

2011-02-25T23:59:59.000Z

442

Low-frequency electromagnetic field in a Wigner crystal  

SciTech Connect (OSTI)

Long-wave low-frequency oscillations are described in a Wigner crystal by generalization of the reverse continuum model for the case of electronic lattice. The internal self-consistent long-wave electromagnetic field is used to describe the collective motions in the system. The eigenvectors and eigenvalues of the obtained system of equations are derived. The velocities of longitudinal and transversal sound waves are found.

Stupka, Anton [Oles Honchar Dnipropetrovs'k National University, Gagarin Ave., 72, 49010 Dnipropetrovs'k (Ukraine)

2013-03-15T23:59:59.000Z

443

Multiply Charged Thorium Crystals for Nuclear Laser Spectroscopy  

SciTech Connect (OSTI)

We have produced laser-cooled crystals of {sup 232}Th{sup 3+} in a linear rf Paul trap. This is the first time that a multiply charged ion has been laser cooled. Our work opens an avenue for excitation of the nuclear transition in a trapped, cold {sup 229}Th{sup 3+} ion. Laser excitation of nuclear states would establish a new bridge between atomic and nuclear physics, with the promise of new levels of metrological precision.

Campbell, C. J.; Steele, A. V.; Churchill, L. R.; DePalatis, M. V.; Naylor, D. E.; Kuzmich, A.; Chapman, M. S. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States); Matsukevich, D. N. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States); Department of Physics and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

2009-06-12T23:59:59.000Z

444

Design of photonic crystal microcavities for cavity QED  

E-Print Network [OSTI]

We discuss the optimization of optical microcavity designs based on 2D photonic crystals for the purpose of strong coupling between the cavity field and a single neutral atom trapped within a hole. We present numerical predictions for the quality factors and mode volumes of localized defect modes as a function of geometric parameters, and discuss some experimental challenges related to the coupling of a defect cavity to gas-phase atoms.

Jelena Vuckovic; Marko Loncar; Hideo Mabuchi; Axel Scherer

2002-08-15T23:59:59.000Z

445

Local tuning of photonic crystal cavities using chalcogenide glasses  

E-Print Network [OSTI]

We demonstrate a method to locally change the refractive index in planar optical devices by photodarkening of a thin chalcogenide glass layer deposited on top of the device. The method is used to tune the resonance of GaAs-based photonic crystal cavities by up to 3 nm at 940 nm, with only 5% deterioration in cavity quality factor. The method has broad applications for postproduction tuning of photonic devices.

Andrei Faraon; Dirk Englund; Douglas Bulla; Barry Luther-Davies; Benjamin J. Eggleton; Nick Stoltz; Pierre Petroff; Jelena Vuckovic

2007-11-09T23:59:59.000Z

446

Local Quantum Dot Tuning on Photonic Crystal Chips  

E-Print Network [OSTI]

Quantum networks based on InGaAs quantum dots embedded in photonic crystal devices rely on QDs being in resonance with each other and with the cavities they are embedded in. We developed a new technique based on temperature tuning to spectrally align different quantum dots located on the same chip. The technique allows for up to 1.8nm reversible on-chip quantum dot tuning.

Andrei Faraon; Dirk Englund; Ilya Fushman; Nick Stoltz; Pierre Petroff; Jelena Vuckovic

2007-03-28T23:59:59.000Z

447

Invariant patterns in crystal lattices: Implications for protein folding algorithms  

SciTech Connect (OSTI)

Crystal lattices are infinite periodic graphs that occur naturally in a variety of geometries and which are of fundamental importance in polymer science. Discrete models of protein folding use crystal lattices to define the space of protein conformations. Because various crystal lattices provide discretizations of the same physical phenomenon, it is reasonable to expect that there will exist ``invariants`` across lattices that define fundamental properties of protein folding process; an invariant defines a property that transcends particular lattice formulations. This paper identifies two classes of invariants, defined in terms of sublattices that are related to the design of algorithms for the structure prediction problem. The first class of invariants is, used to define a master approximation algorithm for which provable performance guarantees exist. This algorithm can be applied to generalizations of the hydrophobic-hydrophilic model that have lattices other than the cubic lattice, including most of the crystal lattices commonly used in protein folding lattice models. The second class of invariants applies to a related lattice model. Using these invariants, we show that for this model the structure prediction problem is intractable across a variety of three-dimensional lattices. It`` turns out that these two classes of invariants are respectively sublattices of the two- and three-dimensional square lattice. As the square lattices are the standard lattices used in empirical protein folding` studies, our results provide a rigorous confirmation of the ability of these lattices to provide insight into biological phenomenon. Our results are the first in the literature that identify algorithmic paradigms for the protein structure prediction problem which transcend particular lattice formulations.

Hart, W.E.; Istrail, S.

1995-12-11T23:59:59.000Z

448

City of Lake Crystal, Minnesota (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartmentAUDITOhio (UtilityHolyrood, Kansas (UtilityKingfisher,Lafayette Place:Crystal,

449

Surface-polishing process for NaI crystals  

SciTech Connect (OSTI)

Darkening of large arrays of NaI used in high energy physics experiments at SLAC has prompted an investigation of methods for annealing radiation damage. As part of this research, it has been necessary to repolish the flat faces of the NaI crystals. The final polishing parameters are given in this document as well as an indication of some techniques which did not work.

Francis, J.

1982-09-01T23:59:59.000Z

450

Successive Phase Transitions in Antiferroelectric Liquid Crystal Systems  

E-Print Network [OSTI]

An axial next-nearest-neighbor XY model is studied as a model of chiral liquid crystals which exhibit many ferro-, ferri- and antiferroelectric tilted smectic phases. Depending on the values of interaction parameters, this model exhibits Ising symmetric (i.e., the tilt directions of directors are parallel or anti parallel) phases or XY symmetric phases. Phases with each type-of-symmetry show the character of devil's staircase, which has been observed in experiments.

Masaya Koroishi; Masashi Torikai; Mamoru Yamashita

2005-10-03T23:59:59.000Z

451

World's Largest Gold Crystal Studied at Los Alamos  

ScienceCinema (OSTI)

When geologist John Rakovan needed better tools to investigate whether a dazzling 217.78-gram piece of gold was in fact the world's largest single-crystal specimen - a distinguishing factor that would not only drastically increase its market value but also provide a unique research opportunity - he traveled to Los Alamos National Laboratory's Lujan Neutron Scattering Center to peer deep inside the mineral using neutron diffractometry. Neutrons, different from other probes such as X-rays and electrons, are able to penetrate many centimeters deep into most materials. Revealing the inner structure of a crystal without destroying the sample - imperative, as this one is worth an estimated $1.5 million - would allow Rakovan and Lujan Center collaborators Sven Vogel and Heinz Nakotte to prove that this exquisite nugget, which seemed almost too perfect and too big to be real, was a single crystal and hence a creation of nature. Its owner, who lives in the United States, provided the samples to Rakovan to assess the crystallinity of four specimens, all of which had been found decades ago in Venezuela.

Vogel, Sven; Nakotte, Heinz

2015-01-07T23:59:59.000Z

452

Freeze crystallization technology for Kraft black liquor concentration. Third report  

SciTech Connect (OSTI)

About 25% of the purchased energy in the pulp and paper industry is used to concentrate black liquor. The technical feasibility of using freeze concentration to supplement evaporation has been successfully demonstrated, and results indicate that energy consumption can be reduced 45%. After compiling a considerable data base on the characteristics of black liquor at low temperature and after developing a computer program to aid analysis, the process chosen was vacuum freezing-vapor absorption (VFVA). A pilot plant was built and operated; however, due to problems with crystallization of the absorbent and contamination, it was found that maintaining the conditions necessary for a continuous process was not practical at the present state of development. Therefore, indirect freezing was used for all subsequent work. This required the design and fabrication of a simple shuttle crystallizer to replace scraped surface units conventionally used. CSI also developed an integrated ice separation column that combined crystal growth, a concentration gradient, and washing all in one unit. Finally, extensive heat transfer coefficient data were collected so that a preliminary design could be completed for a 350 TPD industrial freeze concentration unit. An economic analysis was calculated in order to compare using evaporation and freeze concentration to process the increased liquor flow from a pulp mill expansion. A 200,000 lb/hr freezing unit used to preconcentrate the mill's entire stream up to 18.7% solids would save $10 to $16 per ton of pulp.

Johnson, W.E.; Rhodes, C.R.

1985-04-01T23:59:59.000Z

453

Spontaneous parametric down conversion in chirped, aperiodically-poled crystals  

E-Print Network [OSTI]

We present a theoretical analysis of the process of spontaneous parametric down conversion (SPDC) in a non-linear crystal characterized by a linearly-chirped X(2) grating along the direction of propagation. Our analysis leads to an expression for the joint spectral amplitude, based on which we can derive various spectral-temporal properties of the photon pairs and of the heralded single photons obtained from the photon pairs, including: the single photon spectrum, the chronocyclic Wigner function and the Schmidt number. The simulations that we present are for the specific case of a collinear SPDC source based on a PPLN crystal with the signal and idler photons emitted close to the telecom window. We discuss the mechanism for spectral broadening due to the presence of a linearly chirped X(2) grating, showing that not only the width but also to some extent the shape of the SPDC spectrum maybe controlled. Also, we discuss how the fact that the different spectral components are emitted on different planes in the crystal leads to single-photon chirp.

X. Sanchez-Lozano; Jose Luis Lucio; Alfred U'Ren

2014-12-23T23:59:59.000Z

454

Generation of vector beams with liquid crystal disclination lines  

E-Print Network [OSTI]

We report that guiding light beams, ranging from continuous beams to femtosecond pulses, along liquid crystal defect lines can transform them into vector beams with various polarization profiles. Using Finite Difference Time Domain numerical solving of Maxwell equations, we confirm that the defect in the orientational order of the liquid crystal induces a defect in the light field with twice the winding number of the liquid crystal defect, coupling the topological invariants of both fields. For example, it is possible to transform uniformly-polarized light into light with a radial polarization profile. Our approach also correctly yields a zero-intensity region near the defect core, which is always present in areas of discontinuous light polarization or phase. Using circularly polarized incident light, we show that defects with non-integer winding numbers can be obtained, where topological constants are preserved by phase vortices, demonstrating coupling between the light's spin, orbital angular momentum and polarization profile. Further, we find an ultrafast femtosecond laser pulse travelling along a defect line splits into multiple intensity regions, again depending on the defect's winding number, allowing applications in beam steering and filtering. Finally, our approach describing generation of complex optical fields via coupling with topological defect lines in optically birefringent nematic fluids can be easily extended to high-intensity beams that affect nematic ordering.

Miha ?an?ula; Miha Ravnik; Slobodan Žumer

2014-08-12T23:59:59.000Z

455

On the Disclination Lines of Nematic Liquid Crystals  

E-Print Network [OSTI]

Defects in liquid crystals are of great practical importance and theoretical interest. Despite tremendous efforts, predicting the location and transition of defects under various topological constraint and external field remains to be a challenge. We investigate defect patterns of nematic liquid crystals confined in three-dimensional spherical droplet and two-dimensional disk under different boundary conditions, within the Landau-de Gennes model. We implement a spectral method that numerically solves the Landau-de Gennes model with high accuracy, which allows us to study the detailed static structure of defects. We observe five types of defect structures. Among them the 1/2-disclination lines are the most stable structure at low temperature. Inspired by numerical results, we obtain the profile of disclination lines analytically. Moreover, the connection and difference between defect patterns under the Landau-de Gennes model and the Oseen-Frank model are discussed. Finally, four conjectures are made to summarize some important characteristics of defects in the Landau-de Gennes theory. This work is a continuing effort to deepen our understanding on defect patterns in nematic liquid crystals.

Yucheng Hu; Yang Qu; Pingwen Zhang

2014-08-25T23:59:59.000Z

456

Dislocation-mediated melting of one-dimensional Rydberg crystals  

SciTech Connect (OSTI)

We consider cold Rydberg atoms in a one-dimensional optical lattice in the Mott regime with a single atom per site at zero temperature. An external laser drive with Rabi frequency {Omega} and laser detuning {Delta} creates Rydberg excitations whose dynamics is governed by an effective spin-chain model with (quasi) long-range interactions. This system possesses intrinsically a large degree of frustration resulting in a ground-state phase diagram in the ({Delta},{Omega}) plane with a rich topology. As a function of {Delta}, the Rydberg blockade effect gives rise to a series of crystalline phases commensurate with the optical lattice that form a so-called devil's staircase. The Rabi frequency {Omega}, on the other hand, creates quantum fluctuations that eventually lead to a quantum melting of the crystalline states. Upon increasing {Omega}, we find that generically a commensurate-incommensurate transition to a floating Rydberg crystal that supports gapless phonon excitations occurs first. For even larger {Omega}, dislocations within the floating Rydberg crystal start to proliferate and a second, Kosterlitz-Thouless-Nelson-Halperin-Young dislocation-mediated melting transition finally destroys the crystalline arrangement of Rydberg excitations. This latter melting transition is generic for one-dimensional Rydberg crystals and persists even in the absence of an optical lattice. The floating phase and the concomitant transitions can, in principle, be detected by Bragg scattering of light.

Sela, Eran; Garst, Markus [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, DE-50937 Koeln (Germany); Punk, Matthias [Physik Department, Technische Universitaet Muenchen, James-Franck-Strasse, DE-85748 Garching (Germany); Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

2011-08-15T23:59:59.000Z

457

Synthesis, Crystal Structure, and Magnetism of ?-Fe1.00(2)Se1.00(3) Single Crystals  

SciTech Connect (OSTI)

Understanding iron-based superconductors requires high-quality impurity-free single crystals. So far they have been elusive for {beta}-FeSe and extraction of intrinsic materials properties has been compromised by several magnetic-impurity phases. Here, we report synchrotron-clean {beta}-FeSe superconducting single crystals grown via LiCl/CsCl flux method. Phase purity yields evidence for a defect-induced weak ferromagnetism that coexists with superconductivity below T{sub c}. In contrast to Fe{sub 1+y}Te-based superconductors, our results reveal that the interstitial Fe(2) site is not occupied and that all contribution to density of states at the Fermi level must come from in-plane Fe(1).

Petrovic, C.; Billinge, S.

2011-06-20T23:59:59.000Z

458

Experiment on heat treatment of glass ceramics, i.e. crystallization Objective: to demonstrate the process of crystallization from an amorphous matrix in a  

E-Print Network [OSTI]

Objective: to demonstrate the process of crystallization from an amorphous matrix in a ceramic system1 27-302 Fall 2001 Lab 1 Experiment on heat treatment of glass ceramics, i.e. crystallization ceramics. Glass ceramics are an interesting class of materials that have been developed fairly recently

Rollett, Anthony D.

459

Measuring the x-ray resolving power of bent potassium acid phthalate diffraction crystals  

SciTech Connect (OSTI)

This report presents the results from measuring the X-ray resolving power of a curved potassium acid phthalate (KAP(001)) spectrometer crystal using two independent methods. It is part of a continuing effort to measure the fundamental diffraction properties of bent crystals that are used to study various characteristics of high temperature plasmas. Bent crystals like KAP(001) do not usually have the same diffraction properties as corresponding flat crystals. Models that do exist to calculate the effect of bending the crystal on the diffraction properties have simplifying assumptions and their accuracy limits have not been adequately determined. The type of crystals that we measured is being used in a spectrometer on the Z machine at Sandia National Laboratories in Albuquerque, New Mexico. The first technique for measuring the crystal resolving power measures the X-ray spectral line width of the characteristic lines from several metal anodes. The second method uses a diode X-ray source and a double crystal diffractometer arrangement to measure the reflectivity curve of the KAP(001) crystal. The width of that curve is inversely proportional to the crystal resolving power. The measurement results are analyzed and discussed.

Haugh, M. J., E-mail: haughmj@nv.doe.gov; Jacoby, K. D. [National Security Technologies, LLC, Livermore, California 94550 (United States); Wu, M.; Loisel, G. P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)

2014-11-15T23:59:59.000Z

460

Barium iodide and strontium iodide crystals andd scintillators implementing the same  

DOE Patents [OSTI]

In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, wherein a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu.sup.2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.

Payne, Stephen A; Cherepy, Nerine J; Hull, Giulia E; Drobshoff, Alexander D; Burger, Arnold

2013-11-12T23:59:59.000Z

Note: This page contains sample records for the topic "tiny crystals glow" 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

Study on LiCl waste salt treatment process by layer melt crystallization  

SciTech Connect (OSTI)

Layer melt crystallization operated in a static mode has been applied to separate Group I and II chlorides from surrogate LiCl waste salt. The effects of operating conditions such as crystal growing rate(or flux) and initial impurity concentration on separation (or concentration) of cesium, strontium and barium involved in a LiCl melts were analyzed. In a layer crystallization process, separation was impaired by occlusion of impurities and by residual melt adhering to LiCl crystal after at the end of the process. The crystal growth rate strongly affects the crystal structure, therefore the separation efficiency, while the effect of the initial Cs and Sr concentration in LiCl molten salt was nearly negligible. (authors)

Cho, Yung-Zun; Lee, Tae-Kyo; Choi, Jung-Hoon; Eun, Hee-Chul; Park, Hwan-Seo; Kim, In-Tae; Park, Geun-Il [Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

2013-07-01T23:59:59.000Z

462

Crystallization and preliminary X-ray analysis of a phosphopentomutase from Bacillus cereus  

SciTech Connect (OSTI)

Phosphopentomutases (PPMs) interconvert D-ribose 5-phosphate and {alpha}-D-ribose 1-phosphate to link glucose and nucleotide metabolism. PPM from Bacillus cereus was overexpressed in Escherichia coli, purified to homogeneity and crystallized. Bacterial PPMs are predicted to contain a di-metal reaction center, but the catalytically relevant metal has not previously been identified. Sparse-matrix crystallization screening was performed in the presence or absence of 50 mM MnCl{sub 2}. This strategy resulted in the formation of two crystal forms from two chemically distinct conditions. The crystals that formed with 50 mM MnCl{sub 2} were more easily manipulated and diffracted to higher resolution. These results suggest that even if the catalytically relevant metal is not known, the crystallization of putative metalloproteins may still benefit from supplementation of the crystallization screens with potential catalytic metals.

Panosian, Timothy D.; Nannemann, David P.; Bachmann, Brian O.; Iverson, T.M. (Vanderbilt)

2013-09-18T23:59:59.000Z

463

Theoretical investigation of the collection of aerosol particles by falling ice crystals  

SciTech Connect (OSTI)

A numerical scheme that determines the collection efficiencies, kernels, and washout rates of aerosol particles (APs) by falling columnar and plate-like ice crystals is presented. A theoretical model for the removal of micron-size APs by falling columnar ice crystals which incorporates gravitational, inertial, thermophoretic, diffusiophoretic and electrostatic forcing has been formulated. This trajectory model which includes computed velocity, temperature and water vapor density fields, was coupled to a flux model which determines the removal of submicron particles due to Brownian diffusion, thermo and diffusio-phoresis as well as electrostatic forcing. This combined model indicates collection efficiencies for APs of radii 0.001 to 10.0 ..mu..m for the columnar ice crystal size distribution. An earlier study provides AP collection efficiencies by ice crystal plates for the ice crystal plate size distribution. The columnar ice crystal-AP collection model indicates that efficiency increases with increasing pressure, temperature or electrostatic charge for decreasing relative humidity.

Miller, N.L.

1987-01-01T23:59:59.000Z

464

Method of bonding single crystal quartz by field-assisted bonding  

DOE Patents [OSTI]

The method of producing a hermetic stable structural bond between quartz crystals includes providing first and second quartz crystals and depositing thin films of borosilicate glass and silicon on portions of the first and second crystals, respectively. The portions of the first and second crystals are then juxtaposed in a surface contact relationship and heated to a temperature for a period sufficient to cause the glass and silicon films to become electrically conductive. An electrical potential is then applied across the first and second crystals for creating an electrostatic field between the adjoining surfaces and causing the juxtaposed portions to be attracted into an intimate contact and form a bond for joining the adjoining surfaces of the crystals.

Curlee, Richard M. (Tijeras, NM); Tuthill, Clinton D. (Edgewood, NM); Watkins, Randall D. (Albuquerque, NM)

1991-01-01T23:59:59.000Z

465

Lithium-cation conductivity and crystal structure of lithium diphosphate  

SciTech Connect (OSTI)

The electrical conductivity of lithium diphosphate Li{sub 4}P{sub 2}O{sub 7} has been measured and jump-like increasing of ionic conductivity at 913 K has been found. The crystal structure of Li{sub 4}P{sub 2}O{sub 7} has been refined using high temperature neutron diffraction at 300–1050 K. At 913 K low temperature triclinic form of Li{sub 4}P{sub 2}O{sub 7} transforms into high temperature monoclinic one, space group P2{sub 1}/n, a=8.8261(4) Å, b=5.2028(4) Å, c=13.3119(2) Å, ?=104.372(6)°. The migration maps of Li{sup +} cations based on experimental data implemented into program package TOPOS have been explored. It was found that lithium cations in both low- and high temperature forms of Li{sub 4}P{sub 2}O{sub 7} migrate in three dimensions. Cross sections of the migrations channels extend as the temperature rises, but at the phase transition point have a sharp growth showing a strong “crystal structure – ion conductivity” correlation. -- Graphical abstract: Crystal structure of Li{sub 4}P{sub 2}O{sub 7} at 950 K. Red balls represent oxygen atoms; black lines show Li{sup +} ion migration channels in the layers perpendicular to [001] direction. Highlights: • Structure of Li{sub 4}P{sub 2}O{sub 7} has been refined using high temperature neutron diffraction. • At 913 K triclinic form of Li{sub 4}P{sub 2}O{sub 7} transforms into high temperature monoclinic one. • The migration maps of Li{sup +} implemented into program package TOPOS have been explored. • Cross sections of the migrations channels at the phase transition have a sharp growth.

Voronin, V.I., E-mail: voronin@imp.uran.ru [Institute of Metal Physics Urals Branch RAS, S.Kovalevskoy Street 18, 620041 Ekaterinburg (Russian Federation); Sherstobitova, E.A. [Institute of Metal Physics Urals Branch RAS, S.Kovalevskoy Street 18, 620041 Ekaterinburg (Russian Federation); Blatov, V.A., E-mail: blatov@samsu.ru [Samara Center for Theoretical Materials Science (SCTMS), Samara State University, Ac.Pavlov Street 1, 443011 Samara (Russian Federation); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Shekhtman, G.Sh., E-mail: shekhtman@ihte.uran.ru [Institute of High Temperature Electrochemistry Urals Branch RAS, Akademicheskaya 20, 620990 Ekaterinburg (Russian Federation)

2014-03-15T23:59:59.000Z

466

Electro-optic crystal mosaics for the generation of terahertz radiation  

DOE Patents [OSTI]

Apparatus for the generation of high energy terahertz radiation is presented and comprises laser means effective to produce subpicosecond optical pulses and a mosaic comprising a plurality of planar electro-optic crystals fastened together edge to edge in the form of a grid. The electro-optic crystals are in optical communication with the subpicosecond optical pulses, and behave as a single large electro-optic crystal, producing high energy terahertz radiation by way of optical rectification.

Carrig, Timothy J. (Los Alamos, NM); Taylor, Antoinette J. (Los Alamos, NM); Stewart, Kevin R. (Schenectady, NY)

1996-01-01T23:59:59.000Z

467

Use of Crystals for High Energy Photon Beam Linear Polarization Conversion into Circular  

E-Print Network [OSTI]

The possibility to convert the photon beam linear polarization into circular one at photon energies of hundreds GeV with the use of crystals is considered. The energy and orientation dependencies of refractive indexes are investigated in case of diamond, silicon and germanium crystal targets. To maximize the values for figure of merit, the corresponding crystal optimal orientation angles and thickness are found. The degree of circular polarization and intensity of photon beam are estimated and possibility of experimental realization is discussed.

N. Z. Akopov; A. B. Apyan; S. M. Darbinyan

2000-02-17T23:59:59.000Z

468

Use of Crystals for High Energy Photon Beam Linear Polarization Conversion into Circular  

E-Print Network [OSTI]

The possibility to convert the photon beam linear polarization into circularone at photon energies of hundreds GeV with the use of crystals is considered.The energy and orientation dependencies of refractive indexes are investigatedin case of diamond, silicon and germanium crystal targets. To maximize thevalues for figure of merit, the corresponding crystal optimal orientationangles and thickness are found. The degree of circular polarization andintensity of photon beam are estimated and possibility of experimentalrealization is discussed.

Akopov, N Z; Darbinian, S M

2000-01-01T23:59:59.000Z

469

Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter  

E-Print Network [OSTI]

Ensuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered.

The CMS Electromagnetic Calorimeter Group; P. Adzic; N. Almeida; D. Andelin; I. Anicin; Z. Antunovic; R. Arcidiacono; M. W. Arenton; E. Auffray; S. Argiro; A. Askew; S. Baccaro; S. Baffioni; M. Balazs; D. Bandurin; D. Barney; L. M. Barone; A. Bartoloni; C. Baty; S. Beauceron; K. W. Bell; C. Bernet; M. Besancon; B. Betev; R. Beuselinck; C. Biino; J. Blaha; P. Bloch; A. Borisevitch; A. Bornheim; J. Bourotte; R. M. Brown; M. Buehler; P. Busson; B. Camanzi; T. Camporesi; N. Cartiglia; F. Cavallari; A. Cecilia; P. Chang; Y. H. Chang; C. Charlot; E. A. Chen; W. T. Chen; Z. Chen; R. Chipaux; B. C. Choudhary; R. K. Choudhury; D. J. A. Cockerill; S. Conetti; S. Cooper; F. Cossutti; B. Cox; D. G. Cussans; I. Dafinei; D. R. Da Silva Di Calafiori; G. Daskalakis; A. David; K. Deiters; M. Dejardin; A. De Benedetti; G. Della Ricca; D. Del Re; D. Denegri; P. Depasse; J. Descamps; M. Diemoz; E. Di Marco; G. Dissertori; M. Dittmar; L. Djambazov; M. Djordjevic; L. Dobrzynski; A. Dolgopolov; S. Drndarevic; G. Drobychev; D. Dutta; M. Dzelalija; A. Elliott-Peisert; H. El Mamouni; I. Evangelou; B. Fabbro; J. L. Faure; J. Fay; A. Fedorov; F. Ferri; D. Franci; G. Franzoni; K. Freudenreich; W. Funk; S. Ganjour; S. Gascon; M. Gataullin; F. X. Gentit; A. Ghezzi; A. Givernaud; S. Gninenko; A. Go; B. Gobbo; N. Godinovic; N. Golubev; P. Govoni; N. Grant; P. Gras; M. Haguenauer; G. Hamel de Monchenault; M. Hansen; J. Haupt; H. F. Heath; B. Heltsley; W. Hintz; R. Hirosky; P. R. Hobson; A. Honma; G. W. S. Hou; Y. Hsiung; M. Huhtinen; B. Ille; Q. Ingram; A. Inyakin; P. Jarry; C. Jessop; D. Jovanovic; K. Kaadze; V. Kachanov; S. Kailas; S. K. Kataria; B. W. Kennedy; P. Kokkas; T. Kolberg; M. Korjik; N. Krasnikov; D. Krpic; Y. Kubota; C. M. Kuo; P. Kyberd; A. Kyriakis; M. Lebeau; P. Lecomte; P. Lecoq; A. Ledovskoy; M. Lethuillier; S. W. Lin; W. Lin; V. Litvine; E. Locci; E. Longo; D. Loukas; P. D. Luckey; W. Lustermann; Y. Ma; M. Malberti; J. Malclès; D. Maletic; N. Manthos; Y. Maravin; C. Marchica; N. Marinelli; A. Markou; C. Markou; M. Marone; V. Matveev; C. Mavrommatis; P. Meridiani; P. Milenovic; P. Miné; O. Missevitch; A. K. Mohanty; F. Moortgat; P. Musella; Y. Musienko; A. Nardulli; J. Nash; P. Nedelec; P. Negri; H. B. Newman; A. Nikitenko; F. Nessi-Tedaldi; M. M. Obertino; G. Organtini; T. Orimoto; M. Paganoni; P. Paganini; A. Palma; L. Pant; A. Papadakis; I. Papadakis; I. Papadopoulos; R. Paramatti; P. Parracho; N. Pastrone; J. R. Patterson; F. Pauss; J-P. Peigneux; E. Petrakou; D. G. Phillips II; P. Piroué; F. Ptochos; I. Puljak; A. Pullia; T. Punz; J. Puzovic; S. Ragazzi; S. Rahatlou; J. Rander; P. A. Razis; N. Redaelli; D. Renker; S. Reucroft; P. Ribeiro; C. Rogan; M. Ronquest; A. Rosowsky; C. Rovelli; P. Rumerio; R. Rusack; S. V. Rusakov; M. J. Ryan; L. Sala; R. Salerno; M. Schneegans; C. Seez; P. Sharp; C. H. Shepherd-Themistocleous; J. G. Shiu; R. K. Shivpuri; P. Shukla; C. Siamitros; D. Sillou; J. Silva; P. Silva; A. Singovsky; Y. Sirois; A. Sirunyan; V. J. Smith; F. Stöckli; J. Swain; T. Tabarelli de Fatis; M. Takahashi; V. Tancini; O. Teller; K. Theofilatos; C. Thiebaux; V. Timciuc; C. Timlin; M. Titov; A. Topkar; F. A. Triantis; S. Troshin; N. Tyurin; K. Ueno; A. Uzunian; J. Varela; P. Verrecchia; J. Veverka; T. Virdee; M. Wang; D. Wardrope; M. Weber; J. Weng; J. H. Williams; Y. Yang; I. Yaselli; R. Yohay; A. Zabi; S. Zelepoukine; J. Zhang; L. Y. Zhang; K. Zhu; R. Y. Zhu

2009-12-22T23:59:59.000Z

470

Quantum optics and cavity QED with quantum dots in photonic crystals  

E-Print Network [OSTI]

This chapter will primarily focus on the studies of quantum optics with semiconductor, epitaxially grown quantum dots embedded in photonic crystal cavities. We will start by giving brief introductions into photonic crystals and quantum dots, then proceed with the introduction to cavity quantum electrodynamics (QED) effects, with a particular emphasis on the demonstration of these effects on the quantum dot-photonic crystal platform. Finally, we will focus on the applications of such cavity QED effects.

Jelena Vuckovic

2014-02-11T23:59:59.000Z

471

Enhanced photodetection in graphene-integrated photonic crystal cavity  

SciTech Connect (OSTI)

We demonstrate the controlled enhancement of photoresponsivity in a graphene photodetector by coupling to slow light modes in a long photonic crystal linear defect cavity. Near the Brillouin zone (BZ) boundary, spectral coupling of multiple cavity modes results in broad-band photocurrent enhancement from 1530?nm to 1540?nm. Away from the BZ boundary, individual cavity resonances enhance the photocurrent eight-fold in narrow resonant peaks. Optimization of the photocurrent via critical coupling of the incident field with the graphene-cavity system is discussed. The enhanced photocurrent demonstrates the feasibility of a wavelength-scale graphene photodetector for efficient photodetection with high spectral selectivity and broadband response.

Shiue, Ren-Jye; Englund, Dirk, E-mail: englund@mit.edu [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Gan, Xuetao; Li, Luozhou; Yao, Xinwen [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States)] [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States); Gao, Yuanda; Hone, James [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States)] [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Szep, Attila; Walker, Dennis [Air Force Research Laboratory, Sensors Directorate, WPAFB, Dayton, Ohio 45433 (United States)] [Air Force Research Laboratory, Sensors Directorate, WPAFB, Dayton, Ohio 45433 (United States)

2013-12-09T23:59:59.000Z

472

Millisecond time resolution neutron reflection from a nematic liquid crystal  

SciTech Connect (OSTI)

The director reorientation of the liquid crystal 4,4' octyl cyanobiphenyl in the nematic phase under application of bursts of ac field have been observed using time-resolved neutron scattering in reflection geometry. The relaxation of the director has been shown to agree with existing theory, as determined by material and cell parameters. This result shows that it is possible to use neutron reflection measurements from buried interfaces to follow kinetic processes on a time scale comparable with the pulse length of the ISIS neutron source (20 ms)

Dalgliesh, R.M.; Lau, Y.G.J.; Richardson, R.M.; Riley, D.J. [ISIS Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS (United Kingdom)

2004-09-01T23:59:59.000Z

473

Note: Portable rare-earth element analyzer using pyroelectric crystal  

SciTech Connect (OSTI)

We report a portable rare-earth element analyzer with a palm-top size chamber including the electron source of a pyroelectric crystal and the sample stage utilizing cathodoluminescence (CL) phenomenon. The portable rare-earth element analyzer utilizing CL phenomenon is the smallest reported so far. The portable rare-earth element analyzer detected the rare-earth elements Dy, Tb, Er, and Sm of ppm order in zircon, which were not detected by scanning electron microscopy-energy dispersive X-ray spectroscopy analysis. We also performed an elemental mapping of rare-earth elements by capturing a CL image using CCD camera.

Imashuku, Susumu, E-mail: imashuku.susumu.2m@kyoto-u.ac.jp; Fuyuno, Naoto; Hanasaki, Kohei; Kawai, Jun [Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto 606-8501 (Japan)] [Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto 606-8501 (Japan)

2013-12-15T23:59:59.000Z

474

Nonlinear optical crystal optimized for Ytterbium laser host wavelengths  

DOE Patents [OSTI]

A material for harmonic generation has been made by substitutional changes to the crystal LaCa.sub.4 (BO.sub.3).sub.3 also known as LaCOB in the form Re1.sub.xRe2.sub.yRe3.sub.zCa.sub.4(B0.sub.3).sub.3O where Re1 and Re2, (rare earth ion 1 and rare earth ion 2) are selected from the group consisting of Sc, Yttrium, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu; Re3 is Lanthanum; and x+y+z=1.

Ebbers, Christopher A. (Pleasanton, CA); Schaffers, Kathleen I. (Livermore, CA)

2008-05-27T23:59:59.000Z

475

Nonlinear optical crystal optimized for Ytterbium laser host wavelengths  

DOE Patents [OSTI]

A material for harmonic generation has been made by substitutional changes to the crystal LaCa.sub.4 (BO.sub.3).sub.3 also known as LaCOB in the form Re1.sub.xRe2.sub.yRe3.sub.zCa.sub.4(BO.sub.3).sub.3O where Re1 and Re2, (rare earth ion 1 and rare earth ion 2) are selected from the group consisting of Sc, Yttrium, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; Re3 is Lanthanum; and x+y+z=1.

Ebbers, Christopher A. (Livermore, CA); Schaffers, Kathleen I. (Pleasanton, CA)

2007-02-20T23:59:59.000Z

476

Nonlinear optical crystal optimized for ytterbium laser host wavelengths  

DOE Patents [OSTI]

A material for harmonic generation has been made by substitutional changes to the crystal LaCa.sub.4(BO.sub.3).sub.3 also known as LaCOB in the form Re1.sub.xRe2.sub.yRe3.sub.zCa.sub.4(B0.sub.3).sub.3O where Re1 and Re2, (rare earth ion 1 and rare earth ion 2) are selected from the group consisting of Sc, Yttrium, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; Re3 is Lanthanum; and x+y+z=1.

Ebbers, Christopher A. (Livermore, CA); Schaffers, Kathleen I. (Pleasanton, CA)

2007-08-21T23:59:59.000Z

477

Waveguide-integrated photonic crystal spectrometer with camera readout  

SciTech Connect (OSTI)

We demonstrate an infrared spectrometer based on waveguide-coupled nanocavity filters in a planar photonic crystal structure. The input light is coupled into the waveguide, from which spectral components are dropped into the cavities and radiated off-chip for detection on a commercial InGaAs camera. The spectrometer has a footprint of only 60??m by 8??m. The spectral resolution is about 1?nm in the operation bandwidth of 1522–1545?nm. By substituting the membrane material and structure parameters, this design can be easily extended into the visible regime and developed for a variety of highly efficient, miniature photonic applications.

Meng, Fan; Shiue, Ren-Jye; Li, Luozhou; Nie, Jing; Harris, Nicholas C.; Chen, Edward H.; Schröder, Tim; Englund, Dirk, E-mail: englund@mit.edu [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139 (United States); Wan, Noel [Department of Physics, Columbia University, New York, New York 10027 (United States); Pervez, Nadia [Chromation Partners LLC, 18 Bridge Street Suite 2J, Brooklyn, New York 11201 (United States); Kymissis, Ioannis [Chromation Partners LLC, 18 Bridge Street Suite 2J, Brooklyn, New York 11201 (United States); Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States)

2014-08-04T23:59:59.000Z

478

Diamond turning of Si and Ge single crystals  

SciTech Connect (OSTI)

Single-point diamond turning studies have been completed on Si and Ge crystals. A new process model was developed for diamond turning which is based on a critical depth of cut for plastic flow-to-brittle fracture transitions. This concept, when combined with the actual machining geometry for single-point turning, predicts that {open_quotes}ductile{close_quotes} machining is a combined action of plasticity and fracture. Interrupted cutting experiments also provide a meant to directly measure the critical depth parameter for given machining conditions.

Blake, P.; Scattergood, R.O.

1988-12-01T23:59:59.000Z

479

Chirality in Liquid Crystals: from Microscopic Origins to Macroscopic Structure  

E-Print Network [OSTI]

Molecular chirality leads to a wonderful variety of equilibrium structures, from the simple cholesteric phase to the twist-grain-boundary phases, and it is responsible for interesting and technologically important materials like ferroelectric liquid crystals. This paper will review some recent advances in our understanding of the connection between the chiral geometry of individual molecules and the important phenomenological parameters that determine macroscopic chiral structure. It will then consider chiral structure in columnar systems and propose a new equilibrium phase consisting of a regular lattice of twisted ropes.

T. C. Lubensky; A. B. Harris; Randall D. Kamien; Gu Yan

1997-10-31T23:59:59.000Z

480

An ion trap built with photonic crystal fibre technology  

E-Print Network [OSTI]

We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787(24) quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 um and 10 um.

F. Lindenfelser; B. Keitch; D. Kienzler; D. Bykov; P. Uebel; M. A. Schmidt; P. St. J. Russell; J. P. Home

2015-01-20T23:59:59.000Z

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


481

An ion trap built with photonic crystal fibre technology  

E-Print Network [OSTI]

We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787(24) quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 um and 10 um.

Lindenfelser, F; Kienzler, D; Bykov, D; Uebel, P; Schmidt, M A; Russell, P St J; Home, J P

2015-01-01T23:59:59.000Z

482

Method for thermal processing alumina-enriched spinel single crystals  

DOE Patents [OSTI]

A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly.

Jantzen, Carol M. (Aiken, SC)

1995-01-01T23:59:59.000Z

483

Method for thermal processing alumina-enriched spinel single crystals  

DOE Patents [OSTI]

A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly. 12 figs.

Jantzen, C.M.

1995-05-09T23:59:59.000Z

484

Modeling of Photonic Band Gap Crystals and Applications  

SciTech Connect (OSTI)

In this work, the authors have undertaken a theoretical approach to the complex problem of modeling the flow of electromagnetic waves in photonic crystals. The focus is to address the feasibility of using the exciting phenomena of photonic gaps (PBG) in actual applications. The authors start by providing analytical derivations of the computational electromagnetic methods used in their work. They also present a detailed explanation of the physics underlying each approach, as well as a comparative study of the strengths and weaknesses of each method. The Plane Wave expansion, Transfer Matrix, and Finite Difference time Domain Methods are addressed. They also introduce a new theoretical approach, the Modal Expansion Method. They then shift the attention to actual applications. They begin with a discussion of 2D photonic crystal wave guides. The structure addressed consists of a 2D hexagonal structure of air cylinders in a layered dielectric background. Comparison with the performance of a conventional guide is made, as well as suggestions for enhancing it. The studies provide an upper theoretical limit on the performance of such guides, as they assumed no crystal imperfections and non-absorbing media. Next, they study 3D metallic PBG materials at near infrared and optical wavelengths. The main objective is to study the importance of absorption in the metal and the suitability of observing photonic band gaps in such structures. They study simple cubic structures where the metallic scatters are either cubes or interconnected metallic rods. Several metals are studied (aluminum, gold, copper, and silver). The effect of topology is addressed and isolated metallic cubes are found to be less lossy than the connected rod structures. The results reveal that the best performance is obtained by choosing metals with a large negative real part of the dielectric function, together with a relatively small imaginary part. Finally, they point out a new direction in photonic crystal research that involves the interplay of metallic-PBG rejection and photonic band edge absorption. They propose that an absolute metallic-PBG may be used to suppress the infrared part of the blackbody emission and, emit its energy only through a sharp absorption band. Potential applications of this new PBG mechanism include highly efficient incandescent lamps and enhanced thermophotovoltaic energy conversion. The suggested lamp would be able to recycle the energy that would otherwise go into the unwanted heat associated with usual lamps, into light emitted in the visible spectrum. It is estimated this would increase the efficiency over conventional lamps by about 40%.

Ihab Fathy El-Kady

2002-08-27T23:59:59.000Z

485

HLW Glass Studies: Development of Crystal-Tolerant HLW Glasses  

SciTech Connect (OSTI)

In our study, a series of lab-scale crucible tests were performed on designed glasses of different compositions to further investigate and simulate the effect of Cr, Ni, Fe, Al, Li, and RuO2 on the accumulation rate of spinel crystals in the glass discharge riser of the HLW melter. The experimental data were used to expand the compositional region covered by an empirical model developed previously (Matyᚠet al. 2010b), improving its predictive performance. We also investigated the mechanism for agglomeration of particles and impact of agglomerates on accumulation rate. In addition, the TL was measured as a function of temperature and composition.

Matyas, Josef; Huckleberry, Adam R.; Rodriguez, Carmen P.; Lang, Jesse B.; Owen, Antionette T.; Kruger, Albert A.

2012-04-02T23:59:59.000Z

486

Sequential tasks performed by catalytic pumps for colloidal crystallization  

E-Print Network [OSTI]

Gold-platinum catalytic pumps immersed in a chemical fuel are used to manipulate silica colloids. The manipulation relies on the electric field and the fluid flow generated by the pump. Catalytic pumps perform various tasks, such as the repulsion of colloids, the attraction of colloids, and the guided crystallization of colloids. We demonstrate that catalytic pumps can execute these tasks sequentially over time. Switching from one task to the next is related to the local change of the proton concentration, which modifies the colloid zeta potential and consequently the electric force acting on the colloids.

Ali Afshar Farniya; Maria J. Esplandiu; Adrian Bachtold

2014-10-20T23:59:59.000Z

487

MSET modeling of Crystal River-3 venturi flow meters.  

SciTech Connect (OSTI)

The analysis of archived Crystal River-3 feedwater flow data reveals a slow and steady degradation of the flow meter measurements during the 1992/1993 operating cycle. MSET can reliably estimate the true flow rate and quantify the degree of departure between the indicated signal and the true flow rate with high accuracy. The MSET computed flow rate could, in principle, be used to provide an improved estimate of the reactor power and hence avoid the revenue loss associated with derating the reactor based on a faulty feedwater flow rate indication.

Bockhorst, F. K.; Gross, K. C.; Herzog, J. P.; Wegerich, S. W.

1998-01-05T23:59:59.000Z

488

Low-Threshold Surface-Passivated Photonic Crystal Nanocavity Laser  

E-Print Network [OSTI]

The efficiency and operating range of a photonic crystal laser is improved by passivating the InGaAs quantum well (QW) gain medium and GaAs membrane using an (NH4)S treatment. The passivated laser shows a four-fold reduction in nonradiative surface recombination rate, resulting in a four-fold reduction in lasing threshold. A three-level carrier dynamics model explains the results and shows that lasing threshold is as much determined by surface recombination losses as by the cavity quality factor (Q). Surface passivation therefore appears crucial in operating such lasers under practical conditions.

Dirk Englund; Hatice Altug; Jelena Vuckovic

2007-06-21T23:59:59.000Z

489

Nanobeam Photonic Crystal Cavity Light-Emitting Diodes  

E-Print Network [OSTI]

We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densities possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results open the door for efficient electrical control of active nanobeam cavities for diverse nanophotonic applications.

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2011-01-01T23:59:59.000Z

490

A microfluidic device for investigating crystal nucleation kinetics  

E-Print Network [OSTI]

We have developed an original setup using microfluidic tools allowing one to produce continuously monodisperse microreactors ($\\approx 100$ nL), and to control their temperatures as they flow in the microdevice. With a specific microchannels geometry, we are able to apply large temperature quenches to droplets containing a KNO$_3$ solution (up to 50$^{\\circ}$C in 10 s), and then to follow nucleation kinetics at high supersaturations. By measuring the probability of crystal presence in the droplets as a function of time, we estimate the nucleation rate for different supersaturations, and confront our results to the classical nucleation theory.

Philippe Laval; Jean-Baptiste Salmon; Mathieu Joanicot

2006-12-20T23:59:59.000Z

491

Crystal nucleation and near-epitaxial growth in nacre  

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492

New Crystal Structures Lift Fog around Protein Folding  

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493

Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties  

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494

Crystal Structure and Functional Analysis Identify Evolutionary Secret of  

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495

Crystal Structure of a Protein Kinase A Complex  

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496

Crystal Structure of a Protein Kinase A Complex  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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497

Crystal Structure of a Protein Kinase A Complex  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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498

Crystal Structure of an Anthrax Toxin -Host Cell Receptor Complex  

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499

Crystal structure of a macrophage migration inhibitory factor from Giardia  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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500

Surface structure of cleaved (001) USb2 single crystal surface  

SciTech Connect (OSTI)

We have achieved what we believe to be the first atomic resolution scanning tunneling microscopy (STM) images for a uranium compound USb2 taken at room temperature. The a, b, and c lattice parameters in the images confirm that the tetragonal USb2 crystals cleave on the (001) basal plane as expected. Our calculations indicate a symmetric cut between Sb planes to be the most favorable cleavage plane and U atoms to be responsible for most of the density of states measured by STM. Since the spacing between Sb atoms and between U atoms is the same, STM topography alone cannot unambiguously identify the surface atom species.

Chen, Shao-ping [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z