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Sample records for fissile material transfers

  1. Canyon transfer neutron absorber to fissile material ratio analysis. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Clemmons, J.S.

    1994-03-04

    Waste tank fissile material and non-fissile material estimates are used to evaluate criticality safety for the existing sludge inventory and batches of sludge sent to Extended Sludge Processing (ESP). This report documents the weight ratios of several non-fissile waste constituents to fissile waste constituents from canyon reprocessing waste streams. Weight ratios of Fe, Mn, Al, Mi, and U-238 to fissile material are calculated from monthly loss estimates from the F and H Canyon Low Heat Waste (LHW) and High Heat Waste (HHW) streams. The monthly weight ratios for Fe, Mn and U-238 are then compared to calculated minimum safe weight ratios. Documented minimum safe weight ratios for Al and Ni to fissile material are currently not available. Total mass data for the subject sludge constituents is provided along with scatter plots of the monthly weight ratios for each waste stream.

  2. Technologies for Fissile Material Detection and Prevention of Fissile Material Introduction into International Shipping

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, J

    2003-07-01

    Prevention of the introduction of fissile materials into international shipping, and hence into a given country, is a complex problem. Some pieces of the solution to the puzzle are conceptually well defined, but lack definition of a technical pathway and/or operational implementation. Other elements are a little more fuzzy, and some elements are probably undefined at this point in time. This paper reviews the status of the more well-defined elements, and suggests needed additional measures to enhance the probability that fissile materials are not illicitly introduced into distant countries. International commerce proceeds through a number of steps from point of origin to final destination. Each step offers the possibility of a well-defined choke point to monitor and interdict the illicit shipment of fissile materials. However, because there are so many potential points and venues of entry into a large country such as the United States (e.g., air cargo, shipping containers, truck and rail transport, private vehicles, boats and planes, commercial passenger travel), it behooves the world to ensure that fissile material does not illicitly leave its point of origin.

  3. Fissile material disposition program: Screening of alternate immobilization candidates for disposition of surplus fissile materials

    Energy Technology Data Exchange (ETDEWEB)

    Gray, L.W.

    1996-01-08

    With the end of the Cold War, the world faces for the first time the need to dismantle vast numbers of ``excess`` nuclear weapons and dispose of the fissile materials they contain, together with fissile residues in the weapons production complex left over from the production of these weapons. If recently agreed US and Russian reductions are fully implemented, tens of thousands of nuclear weapons, containing a hundred tons or more of plutonium and hundreds of tonnes* of highly enriched uranium (HEU), will no longer be needed worldwide for military purposes. These two materials are the essential ingredients of nuclear weapons, and limits on access to them are the primary technical barrier to prospective proliferants who might desire to acquire a nuclear weapons capability. Theoretically, several kilograms of plutonium, or several times that amount of HEU, is sufficient to make a nuclear explosive device. Therefore, these materials will continue to be a potential threat to humanity for as long as they exist.

  4. γ-ray self-absorption of cylindrical fissile material

    Institute of Scientific and Technical Information of China (English)

    HUANG Yong-Yi; CHENG Yi-Ying; TIAN Dong-Feng; LU Fu-Quan; YANG Fu-Jia

    2005-01-01

    The self-absorption of γ-ray emitted from cylindrical fissile materials, such as 235U and 239Pu, does not possess spherical symmetry. The analytical formulae of self-absorption for γ-ray throughout the cylinder have been obtained. The intensity of γ-ray is a function of γ-ray outgoing directions and cylindrical configurations, accordingly one can acquire the information about geometrical configuration of cylindrical fissile materials through multi-location measurements. Further more, the method is given in this article. The result can be applied to the fissile material safeguard, such as nuclear monitoring and verifying.

  5. 49 CFR 173.453 - Fissile materials-exceptions.

    Science.gov (United States)

    2010-10-01

    ... exceeding 0.002 percent of the mass of uranium, and with a minimum nitrogen to uranium atomic ratio (N/U) of... determining the required mass for solid nonfissile material. (c) Low concentrations of solid fissile material... required mass of solid nonfissile material. (d) Uranium enriched in uranium-235 to a maximum of 1...

  6. Leo Szilard Lectureship Award: Fissile Materials: A Global Threat

    Science.gov (United States)

    Rajaraman, Ramamurti

    2014-03-01

    The world has built up a huge glut of Fissile Materials, posing a potentially devastating threat. While specialists in the field have been aware of this danger for a long time, it was only after President Obama organized the Nuclear Security Summit in 2010 that the attention of the world's political leadership was drawn to it. We will present here an introductory overview of Fissile materials - their definition, significance and their production facilities and stocks in different parts of the world. We will also mention some of the efforts being made to verifiably cap and reduce their stocks as well as the technical and political complications involved in the process.

  7. Controlling Weapons-Grade Fissile Material

    Science.gov (United States)

    Rotblat, J.

    1977-01-01

    Discusses the problems of controlling weapons-grade fissionable material. Projections of the growth of fission nuclear reactors indicates sufficient materials will be available to construct 300,000 atomic bombs each containing 10 kilograms of plutonium by 1990. (SL)

  8. Gamma ray absorption of cylindrical fissile material with dual shields

    Institute of Scientific and Technical Information of China (English)

    WU Chen-Yan; TIAN Dong-Feng; CHENG Yi-Ying; HUANG Yong-Yi; LU Fu-Quan; YANG Fu-Jia

    2005-01-01

    This work analyzed the gamma ray attenuation effect from the self-absorption and shield attenuation perspectively. An exact mathematical equation was given for the geometric factor of the cylindrical fissile material with dual shields. In addition, several approximation approaches suitable for real situation were discussed, especially in the radial and axial directions of the cylinders, since the G-factors have simple forms. Then the space distribution patterns of the G-factor were analyzed based on numerical result and effective ways to solve the geometric information of the cylindrical fissile material, the radii and the heights, were deduced. This method was checked and verified by numerical calculation. Because of the efficiency of the method, it is ideal for application in real situations, such as nuclear safeguards, which demands speed of detection and accuracy of geometric analysis.

  9. Fissile material storage in the Oak Ridge Radiochemical Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    Primm, R.T. III

    1993-08-01

    As a part of a Department of Energy review of Oak Ridge National Laboratory facilities, nuclear safety documentation for the Radiochemical Development Facility (Building 3019) was found to be inadequate. While calculations existed which established safe limits for the storage of fissile material, these calculations were not performed with verified/validated software nor were the results reported in the manner prescribed by applicable DOE orders and ORNL procedures. To address this deficiency, the operations conducted in Building 3019 were reviewed and conditions were compared to available critical experiment data. Applicable critical experiments were selected and multiplication factors were calculated. Subcritical limits were derived for each of three fissile materials (U-233, U-235, and Pu-239). One application of these limits was to certify the safety of a storage array which could contain any or all of the above nuclides at varying degrees of moderation. The studies presented are believed to fulfill most of the applicable regulatory requirements.

  10. DISSOLUTION OF FISSILE MATERIALS CONTAINING TANTALUM METAL

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T; Mark Crowder, M; Michael Bronikowski, M

    2007-05-29

    The dissolution of composite materials containing plutonium (Pu) and tantalum (Ta) metals is currently performed in Phase I of the HB-Line facility. The conditions for the present flowsheet are the dissolution of 500 g of Pu metal in the 15 L dissolver using a 4 M nitric acid (HNO{sub 3}) solution containing 0.2 M potassium fluoride (KF) at 95 C for 4-6 h.[1] The Ta metal, which is essentially insoluble in HNO{sub 3}/fluoride solutions, is rinsed with process water to remove residual acid, and then burned to destroy classified information. During the initial dissolution campaign, the total mass of Pu and Ta in the dissolver charge was limited to nominally 300 g. The reduced amount of Pu in the dissolver charge coupled with significant evaporation of solution during processing of several dissolver charges resulted in the precipitation of a fluoride salt contain Pu. Dissolution of the salt required the addition of aluminum nitrate (Al(NO{sub 3}){sub 3}) and a subsequent undesired 4 h heating cycle. As a result of this issue, HB-Line Engineering requested the Savannah River National Laboratory (SRNL) to optimize the dissolution flowsheet to reduce the cycle time, reduce the risk of precipitating solids, and obtain hydrogen (H{sub 2}) generation data at lower fluoride concentrations.[2] Using samples of the Pu/Ta composite material, we performed three experiments to demonstrate the dissolution of the Pu metal using HNO{sub 3} solutions containing 0.15 and 0.175 M KF. When 0.15 M KF was used in the dissolving solution, 95.5% of the Pu in the sample dissolved in approximately 6 h. The undissolved material included a small amount of Pu metal and plutonium oxide (PuO{sub 2}) solids. Complete dissolution of the metal would have likely occurred if the dissolution time had been extended. This assumption is based on the steady increase in the Pu concentration observed during the last several hours of the experiment. We attribute the formation of PuO{sub 2} to the complexation

  11. R&D plan for immobilization technologies: fissile materials disposition program. Revision 1.0

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, H.F.; Armantrout, G.A.

    1996-09-01

    In the aftermath of the Cold War, the US and Russia have agreed to large reductions in nuclear weapons. To aid in the selection of long- term fissile material management options, the Department of Energy`s Fissile Materials Disposition Program (FMDP) is conducting studies of options for the storage and disposition of surplus plutonium (Pu). One set of alternatives for disposition involve immobilization. The immobilization alternatives provide for fixing surplus fissile materials in a host matrix in order to create a solid disposal form that is nuclear criticality-safe, proliferation-resistant and environmentally acceptable for long-term storage or disposal.

  12. Non-proliferation, safeguards, and security for the fissile materials disposition program immobilization alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Duggan, R.A.; Jaeger, C.D.; Tolk, K.M. [Sandia National Labs., Albuquerque, NM (United States); Moore, L.R. [Lawrence Livermore National Lab., CA (United States)

    1996-05-01

    The Department of Energy is analyzing long-term storage and disposition alternatives for surplus weapons-usable fissile materials. A number of different disposition alternatives are being considered. These include facilities for storage, conversion and stabilization of fissile materials, immobilization in glass or ceramic material, fabrication of fissile material into mixed oxide (MOX) fuel for reactors, use of reactor based technologies to convert material into spent fuel, and disposal of fissile material using geologic alternatives. This paper will focus on how the objectives of reducing security and proliferation risks are being considered, and the possible facility impacts. Some of the areas discussed in this paper include: (1) domestic and international safeguards requirements, (2) non-proliferation criteria and measures, (3) the threats, and (4) potential proliferation, safeguards, and security issues and impacts on the facilities. Issues applicable to all of the possible disposition alternatives will be discussed in this paper. However, particular attention is given to the plutonium immobilization alternatives.

  13. The Future of Nuclear Archaeology: Reducing Legacy Risks of Weapons Fissile Material

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Thomas W.; Reid, Bruce D.; Toomey, Christopher M.; Krishnaswami, Kannan; Burns, Kimberly A.; Casazza, Larry O.; S. Daly, Don; L. Duckworth, Leesa

    2014-01-01

    This report describes the value proposition for a "nuclear archeological" technical capability and applications program, targeted at resolving uncertainties regarding fissile materials production and use. At its heart, this proposition is that we can never be sure that all fissile material is adequately secure without a clear idea of what "all" means, and that uncertainty in this matter carries risk. We argue that this proposition is as valid today, under emerging state and possible non-state nuclear threats, as it was in an immediate post-Cold-War context, and describe how nuclear archeological methods can be used to verify fissile materials declarations, or estimate and characterize historical fissile materials production independently of declarations.

  14. Fissile and Non-Fissile Material Detection Using Nuclear Acoustic Resonance Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard R. Tittmann; P.M. Lenahan; David Spears; Rhys Williams

    2008-11-25

    The objective of this project is to develop anovel technique for remote, non-destructive, non-radiation-based detection of materials of interest to Nonproliferation Programs. We propse the development of a detection system based on magnetic resonance principles (NAR), which would work where radiation detection is not possible. The approach would be non-intrusive, penetrating, applicable to many materials of interest for Nonproliferation, and be able to identify the nuclear samples under investigation.

  15. Fissile and Non-Fissile Material Detection using Nuclear Acoustic Resonance Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Herberg, J; Maxwell, R; Tittmann, B R; Lenahan, P M; Yerkes, S; Jayaraman, S

    2005-10-04

    This report reviews progress made on NA22 project LL251DP to develop a novel technique, Nuclear Acoustic Resonance (NAR), for remote, non-destructive, nonradiation-based detection of materials of interest to Nonproliferation Programs, including {sup 235}U and {sup 239}Pu. We have met all milestones and deliverables for FY05, as shown in Table 1. In short, we have developed a magnetic shield chamber and magnetic field, develop a digital lock-in amplifier computer to integrate both the ultrasound radiation with the detector, developed strain measurements, and begin to perform initial measurements to obtain a NAR signal from aluminum at room temperature and near the earth's magnetic field. The results obtained in FY05 further support the feasibility of successful demonstration of an NAR experiment for remote, non-destructive, non-radiation-based detection of materials of interest to Nonproliferation Programs.

  16. Fissile and Non-Fissile Material Detection using Nuclear Acoustic Resonance Signatures: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Herberg, J; Maxwell, R; Tittmann, B R; Lenahan, P M; Yerkes, S; Jayaraman, S B

    2006-11-02

    This is final report on NA-22 project LL251DP, where the goal was to develop a novel technique, Nuclear Acoustic Resonance (NAR), for remote, non-destructive, nonradiation-based detection of materials of interest to Nonproliferation Programs, including {sup 235}U and {sup 239}Pu. In short, we have developed a magnetic shield chamber and magnetic field, develop a digital lock-in amplifier computer to integrate both the ultrasound radiation with the detector, developed strain measurements, and begun to perform initial measurements to obtain a NAR signal from aluminum at room temperature and near the earth's magnetic field. Since our funding was cut in FY06, I will discuss where this project can go in the future with this technology.

  17. 49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...

    Science.gov (United States)

    2010-10-01

    ... Type B and fissile materials packagings to withstand accident conditions in transportation. Each Type B packaging or packaging for fissile material must meet the test requirements prescribed in 10 CFR part 71 for... 49 Transportation 2 2010-10-01 2010-10-01 false Tests for demonstrating the ability of Type B...

  18. Assessment and recommendations for fissile-material packaging exemptions and general licenses within 10 CFR Part 71

    Energy Technology Data Exchange (ETDEWEB)

    Parks, C.V.; Hopper, C.M.; Lichtenwalter, J.L. [Oak Ridge National Lab., TN (United States)

    1998-07-01

    This report provides a technical and regulatory assessment of the fissile material general licenses and fissile material exemptions within Title 10 of the Code of Federal Regulations Part 71. The assessment included literature studies and calculational analyses to evaluate the technical criteria; review of current industry practice and concerns; and a detailed evaluation of the regulatory text for clarity, consistency and relevance. Recommendations for potential consideration by the Nuclear Regulatory Commission staff are provided. The recommendations call for a simplification and consolidation of the general licenses and a change in the technical criteria for the first fissile material exemptions.

  19. Basic Research on Remote Sensing of Fissile Materials utilizing Gamma rays and Neutrons

    Science.gov (United States)

    2017-02-01

    6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-15-56 Basic Research on Remote Sensing of Fissile Materials...2017 HDTRA1-09-1-0059 David C. Ingram Prepared by: Ohio University 105 Research and Technology Center Athens, OH...AVAILABILITY STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

  20. LANL's Role in the U.S. Fissile Material Disposition Program

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, Julia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kay, Virginia [NA-233

    2015-02-18

    The process of Fissile Material Disposition is in part a result of the Advanced Recovery and Integrated Extraction System (ARIES), which is an agreement between the U.S. and Russia to dispose of excess plutonium used to make weapons. LANL is one sight that aides in the process of dismantling, storage and repurposing of the plutonium gathered from dismantled weapons. Some uses for the repurposed plutonium is fuel for commercial nuclear reactors which will provide energy for citizens.

  1. Verification of a Fissile Material Cut-off Treaty (FMCT): The Potential Role of the IAEA

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin Ho [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

    2016-05-15

    The objective of a future verification of a FMCT(Fissile Material Cut-off Treaty) is to deter and detect non-compliance with treaty obligations in a timely and non-discriminatory manner with regard to banning the production of fissile material for nuclear weapons or other nuclear devices. Since the International Atomic Energy Agency (IAEA) has already established the IAEA safeguards as a verification system mainly for Non -Nuclear Weapon States (NNWSs), it is expected that the IAEA's experience and expertise in this field will make a significant contribution to setting up a future treaty's verification regime. This paper is designed to explore the potential role of the IAEA in verifying the future treaty by analyzing verification abilities of the Agency in terms of treaty verification and expected challenges. Furthermore, the concept of multilateral verification that could be facilitated by the IAEA will be examined as a measure of providing a credible assurance of compliance with a future treaty. In this circumstance, it is necessary for the IAEA to be prepared for playing a leading role in FMCT verifications as a form of multilateral verification by taking advantage of its existing verification concepts, methods, and tools. Also, several challenges that the Agency faces today need to be overcome, including dealing with sensitive and proliferative information, attribution of fissile materials, lack of verification experience in military fuel cycle facilities, and different attitude and culture towards verification between NWSs and NNWSs.

  2. Fissile material holdup measurement systems: an historical review of hardware and software

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Jeffrey Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Steven E [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rowe, Nathan C [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    The measurement of fissile material holdup is accomplished by passively measuring the energy-dependent photon flux and/or passive neutron flux emitted from the fissile material deposited within an engineered process system. Both measurement modalities--photon and neutron--require the implementation of portable, battery-operated systems that are transported, by hand, from one measurement location to another. Because of this portability requirement, gamma-ray spectrometers are typically limited to inorganic scintillators, coupled to photomultiplier tubes, a small multi-channel analyzer, and a handheld computer for data logging. For neutron detection, polyethylene-moderated, cadmium-back-shielded He-3 thermal neutron detectors are used, coupled to nuclear electronics for supplying high voltage to the detector, and amplifying the signal chain to the scaler for counting. Holdup measurement methods, including the concept of Generalized Geometry Holdup (GGH), are well presented by T. Douglas Reilly in LA-UR-07-5149 and P. Russo in LA-14206, yet both publications leave much of the evolutionary hardware and software to the imagination of the reader. This paper presents an historical review of systems that have been developed and implemented since the mid-1980s for the nondestructive assay of fissile material, in situ. Specifications for the next-generation holdup measurements systems are conjectured.

  3. Processing fissile material mixtures containing zirconium and/or carbon

    Science.gov (United States)

    Johnson, Michael Ernest; Maloney, Martin David

    2013-07-02

    A method of processing spent TRIZO-coated nuclear fuel may include adding fluoride to complex zirconium present in a dissolved TRIZO-coated fuel. Complexing the zirconium with fluoride may reduce or eliminate the potential for zirconium to interfere with the extraction of uranium and/or transuranics from fission materials in the spent nuclear fuel.

  4. Processing fissile material mixtures containing zirconium and/or carbon

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Michael Ernest; Maloney, Martin David

    2013-07-02

    A method of processing spent TRIZO-coated nuclear fuel may include adding fluoride to complex zirconium present in a dissolved TRIZO-coated fuel. Complexing the zirconium with fluoride may reduce or eliminate the potential for zirconium to interfere with the extraction of uranium and/or transuranics from fission materials in the spent nuclear fuel.

  5. Fissile material smuggling: German politics, hype and reality

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.

    1994-12-01

    The spy novel nightmare scenarios of nuclear smuggling have become reality, and much of the recent news has focused on Germany. But these events must be put in perspective, and a number of apparent {open_quotes}facts{close_quotes} must be examined more carefully. For example, while authorities in Germany have seized weapons-usable material in various incidents that have captured international attention, none of this material is from nuclear weapons or weapons production facilities. Moreover, despite the fact that the number of criminal cases has risen, the quantity of {open_quotes}loose{close_quotes} weapons-usable material is still not significant. Nor are there any indications so far that powerful criminal organizations or buyers from nuclear-ambitious {open_quotes}rogue{close_quotes} states are involved. Rather, the incidents so far involve individuals or small groups of criminals who found that their {open_quotes}buyers{close_quotes} were, more often than not, German security agents working {open_quotes}sting{close_quotes} operations to trap the smugglers and black marketeers or journalists working on a {open_quotes}big story.{close_quotes}

  6. Identification of hidden fissile materials using high-pressure xenon gamma-ray detectors

    Science.gov (United States)

    Ulin, Sergey E.; Dmitrenko, Valery V.; Grachev, V. M.; Sokolov, D. V.; Uteshev, Z. M.; Chernysheva, I. V.; Vlasik, K. F.

    2001-12-01

    The description of the High Pressure Xenon Gamma-Ray Detector (HPXeD) and its main characteristics are considered in the context of the search for hidden fissile materials. The results of HPXeD measurements of gamma-radiation from radioactive sources, which are covered by lead, iron and aluminium shields, are analyzed and discussed. The use of special software for processing data is shown to improve the potential of radioactive material detection, including the identification and estimation of the main protective shield parameters.

  7. Fissile materials in solution concentration measured by active neutron interrogation; Mesure de concentration en matiere fissile dans les liquides par interrogation neutronique active

    Energy Technology Data Exchange (ETDEWEB)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-12-31

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a {sup 252} Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.). 6 refs.

  8. Comparative analysis of non-destructive methods to control fissile materials in large-size containers

    Directory of Open Access Journals (Sweden)

    Batyaev V.F.

    2017-01-01

    Full Text Available The analysis of various non-destructive methods to control fissile materials (FM in large-size containers filled with radioactive waste (RAW has been carried out. The difficulty of applying passive gamma-neutron monitoring FM in large containers filled with concreted RAW is shown. Selection of an active non-destructive assay technique depends on the container contents; and in case of a concrete or iron matrix with very low activity and low activity RAW the neutron radiation method appears to be more preferable as compared with the photonuclear one.

  9. The neutron emission method for determination of fissile materials within the spent fuel equipment optimization

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Zaid, A. [Nuclear Research Center, Atomic Energy Authority, 13759- Cairo (Ethiopia); Pytel, K. [Atomic Energy Institute, Research Reactor Center, 05-400 Otwock-Swierk (Poland)

    1998-07-01

    A nondestructive assay method using neutron technique for determination of the fissile isotopes content along the irradiated fuel rods of MARIA reactor is presented. This method is based on detection of the fission neutrons emitted from external neutron source and multiplied by the fissile isotopes U-235, Pu-239, and Pu-241 within the fuel rod. Neutrons emitted from the spent fuel originate mainly from induced fission in the fissile material and source neutrons penetrating the fuel rod without interaction. Additionally, the neutrons from ({alpha}, n) reaction and spontaneous fission of actinide isotopes contribute in the total population of emitted ones. The method gives a chance to perform an experimental calibration of the equipment using two points: fresh fuel rod (maximum signal plus background) and its mock-up (background). The Monte Carlo code has been used for the geometrical simulation and optimization of the measuring equipment: neutron source, moderating container, collimator, and the neutron detector. The results of the calculation show that the moderating container of 30 cm length and 32 cm diameter and a collimator of 26 cm length, 6.8 cm width, and 2 cm height are the optimal configuration. With respect to the fission chamber position, the number of neutrons has been calculated as a function of distance from the fuel rod surface in the case of fresh fuel and its mock-up. The distance, at which the ratio of the signal to background has its maximum, has been found at 4.5 cm far from the outer surface of the fuel. (author)

  10. A single-shot nanosecond neutron pulsed technique for the detection of fissile materials

    Science.gov (United States)

    Gribkov, V.; Miklaszewski, R. A.; Chernyshova, M.; Scholz, M.; Prokopovicz, R.; Tomaszewski, K.; Drozdowicz, K.; Wiacek, U.; Gabanska, B.; Dworak, D.; Pytel, K.; Zawadka, A.

    2012-07-01

    A novel technique with the potential of detecting hidden fissile materials is presented utilizing the interaction of a single powerful and nanosecond wide neutron pulse with matter. The experimental system is based on a Dense Plasma Focus (DPF) device as a neutron source generating pulses of almost mono-energetic 2.45 MeV and/or 14.0 MeV neutrons, a few nanoseconds in width. Fissile materials, consisting of heavy nuclei, are detected utilizing two signatures: firstly by measuring those secondary fission neutrons which are faster than the elastically scattered 2.45 MeV neutrons of the D-D reaction in the DPF; secondly by measuring the pulses of the slower secondary fission neutrons following the pulse of the fast 14 MeV neutrons from the D-T reaction. In both cases it is important to compare the measured spectrum of the fission neutrons induced by the 2.45 MeV or 14 MeV neutron pulse of the DPF with theoretical spectra obtained by mathematical simulation. Therefore, results of numerical modelling of the proposed system, using the MCNP5 and the FLUKA codes are presented and compared with experimental data.

  11. Proceedings from the Fissile Material Cut-off seminar in Stockholm

    Energy Technology Data Exchange (ETDEWEB)

    Arbman, G. [ed.

    1998-07-01

    The Swedish Defence Research Establishment hosted an international expert seminar on the subject of verifying a prohibition of the production of fissile material for nuclear weapons purpose (cut-off) in Stockholm, June 3-5 1998. The objective of the seminar was to provide an opportunity for informal discussions among scientific and technical experts on various technical matters relating to the verification of a future Fissile Material Cut-off Treaty (FMCT). A stated aim of the seminar was to keep issues of scope to a minimum. Invited speakers and commentators were given an opportunity to present their views as written contributions. The present seminar proceedings are essentially the result of these views. In addition, short summaries of the discussions following each session are included. Although an attempt was made to be as complete and accurate as possible in reproducing these discussions, the editors apologise if some important points or statements have been omitted. If so, the main reason is that the documentation of the discussions were based on written notes, not taped recordings. Eight longer contributions have been separately indexed.

  12. In-Drift Accumulation of Fissile Material From Waste Packages Containing Plutonium Disposition Waste Form

    Energy Technology Data Exchange (ETDEWEB)

    H.W> Stockman; S. LeStrange

    2000-09-28

    The objective of this calculation is to provide estimates of the amount of fissile material flowing out of the waste package (source term) and the accumulation of fissile elements (U and Pu) in a crushed-tuff invert. These calculations provide input for the analysis of repository impacts of the Pu-ceramic waste forms. In particular, the source term results are used as input to the far-field accumulation calculation reported in Ref. 51, and the in-drift accumulation results are used as inputs for the criticality calculations reported in Ref. 2. The results are also summarized and interpreted in Ref. 52. The scope of this calculation is the waste package (WP) Viability Assessment (VA) design, which consists of an outer corrosion-allowance material (CAM) and an inner corrosion-resistant material (CRM). This design is used in this calculation in order to be consistent with earlier Pu-ceramic degradation calculations (Ref. 15). The impact of the new Enhanced Design Alternative-I1 (EDA-11) design on the results will be addressed in a subsequent report. The design of the invert (a leveling foundation, which creates a level surface of the drift floor and supports the WP mounting structure) is consistent with the EDA-I1 design. The invert will be composed of crushed stone and a steel support structure (Ref. 17). The scope of this calculation is also defined by the nominal degradation scenario, which involves the breach of the WP (Section 10.5.1.2, Ref. 48), followed by the influx of water. Water in the WP may, in time, gradually leach the fissile components and neutron absorbers out of the ceramic waste forms. Thus, the water in the WP may become laden with dissolved actinides (e.g., Pu and U), and may eventually overflow or leak from the WP. Once the water leaves the WP, it may encounter the invert, in which the actinides may reprecipitate. Several factors could induce reprecipitation; these factors include: the high surface area of the crushed stone, and the presence of

  13. A treaty on the cutoff of fissile material for nuclear weapons - What to cover? How to verify?

    Energy Technology Data Exchange (ETDEWEB)

    Schaper, A. [Peace Research Inst., Frankfurt (Germany)

    1998-07-01

    Since 1946, a cutoff has been proposed. In 1993, the topic was placed on the agenda of the CD. The establishment of an Ad Hoc Committee in the CD with a mandate to negotiate a fissile material cutoff treaty struggled with difficulties for more than a year. The central dispute was whether the mandate should refer to existing un-safeguarded stockpiles. The underlying conflict of the CTBT negotiations can be summarized as nuclear disarmament versus nuclear nonproliferation The same conflict is now blocking progress with FMCT negotiations in the CD. At the center of technical proliferation concerns is direct use material that can be used for nuclear warheads without any further enrichment or reprocessing. Those materials are plutonium and highly enriched uranium (HEU). A broader category of materials is defined as all those containing any fissile isotopes, called special fissionable materials. In order ta verify that no direct use materials are abused for military purposes, also special fissionable materials must be controlled. An even broader category is simply called nuclear materials. Pu and HEU can be distinguished into the following categories of utilisation: 1. military direct use material in operational nuclear weapons and their logistics pipeline, 2. military direct use material held in reserve for military purposes, in assembled weapons or in other forms, 3. military direct use material withdrawn from dismantled weapons, 4. military direct use material considered excess and designated for transfer into civilian use, 5. military direct use material considered excess and declared for transfer into civilian use, 6. direct use material currently in reactors or their logistics pipelines and storages, and 7. irradiated Pu and HEU in spent fuel from reactors, or in vitrified form for final disposal. Large quantities of materials are neither inside weapons nor declared excess. So far, there are no legal obligations for NWS for limitations, declarations, or

  14. Analysis of triso packing fraction and fissile material to DB-MHR using LWR reprocessed fuel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Clarysson A.M. da; Pereira, Claubia; Costa, Antonella L.; Veloso, Maria Auxiliadora F.; Gual, Maritza R., E-mail: clarysson@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: antonella@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br, E-mail: maritzargual@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2013-07-01

    Gas-cooled and graphite-moderated reactor is being considered the next generation of nuclear power plants because of its characteristic to operate with reprocessed fuel. The typical fuel element consists of a hexagonal block with coolant and fuel channels. The fuel pin is manufactured into compacted ceramic-coated particles (TRISO) which are used to achieve both a high burnup and a high degree of passive safety. This work uses the MCNPX 2.6.0 to simulate the active core of Deep Burn Modular Helium Reactor (DB-MHR) employing PWR (Pressurized Water Reactor) reprocessed fuel. However, before a complete study of DB-MHR fuel cycle and recharge, it is necessary to evaluate the neutronic parameters to some values of TRISO Packing Fractions (PF) and Fissile Material (FM). Each PF and FM combination would generate the best behaviour of neutronic parameters. Therefore, this study configures several PF and FM combinations considering the heterogeneity of TRISO layers and lattice. The results present the best combination of PF and FM values according with the more appropriated behaviour of the neutronic parameters during the burnup. In this way, the optimized combination can be used to future works of MHR fuel cycle and recharge. (author)

  15. High-power, photofission-inducing bremsstrahlung source for intense pulsed active detection of fissile material

    Directory of Open Access Journals (Sweden)

    J. C. Zier

    2014-06-01

    Full Text Available Intense pulsed active detection (IPAD is a promising technique for detecting fissile material to prevent the proliferation of special nuclear materials. With IPAD, fissions are induced in a brief, intense radiation burst and the resulting gamma ray or neutron signals are acquired during a short period of elevated signal-to-noise ratio. The 8 MV, 200 kA Mercury pulsed-power generator at the Naval Research Laboratory coupled to a high-power vacuum diode produces an intense 30 ns bremsstrahlung beam to study this approach. The work presented here reports on Mercury experiments designed to maximize the photofission yield in a depleted-uranium (DU object in the bremsstrahlung far field by varying the anode-cathode (AK diode gap spacing and by adding an inner-diameter-reducing insert in the outer conductor wall. An extensive suite of diagnostics was fielded to measure the bremsstrahlung beam and DU fission yield as functions of diode geometry. Delayed fission neutrons from the DU proved to be a valuable diagnostic for measuring bremsstrahlung photons above 5 MeV. The measurements are in broad agreement with particle-in-cell and Monte Carlo simulations of electron dynamics and radiation transport. These show that with increasing AK gap, electron losses to the insert and outer conductor wall increase and that the electron angles impacting the bremsstrahlung converter approach normal incidence. The diode conditions for maximum fission yield occur when the gap is large enough to produce electron angles close to normal, yet small enough to limit electron losses.

  16. Far-Field Accumulation of Fissile Material From Waste Packages Containing Plutonium Disposition Waste Form

    Energy Technology Data Exchange (ETDEWEB)

    J.P. Nicot

    2000-09-29

    The objective of this calculation is to estimate the quantity of fissile material that could accumulate in fractures in the rock beneath plutonium-ceramic (Pu-ceramic) and Mixed-Oxide (MOX) waste packages (WPs) as they degrade in the potential monitored geologic repository at Yucca Mountain. This calculation is to feed another calculation (Ref. 31) computing the probability of criticality in the systems described in Section 6 and then ultimately to a more general report on the impact of plutonium on the performance of the proposed repository (Ref. 32), both developed concurrently to this work. This calculation is done in accordance with the development plan TDP-DDC-MD-000001 (Ref. 9), item 5. The original document described in item 5 has been split into two documents: this calculation and Ref. 4. The scope of the calculation is limited to only very low flow rates because they lead to the most conservative cases for Pu accumulation and more generally are consistent with the way the effluent from the WP (called source term in this calculation) was calculated (Ref. 4). Ref. 4 (''In-Drift Accumulation of Fissile Material from WPs Containing Plutonium Disposition Waste Forms'') details the evolution through time (breach time is initial time) of the chemical composition of the solution inside the WP as degradation of the fuel and other materials proceed. It is the chemical solution used as a source term in this calculation. Ref. 4 takes that same source term and reacts it with the invert; this calculation reacts it with the rock. In addition to reactions with the rock minerals (that release Si and Ca), the basic mechanisms for actinide precipitation are dilution and mixing with resident water as explained in Section 2.1.4. No other potential mechanism such as flow through a reducing zone is investigated in this calculation. No attempt was made to use the effluent water from the bottom of the invert instead of using directly the effluent water from the

  17. Open literature review of threats including sabotage and theft of fissile material transport in Japan.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John Russell; Furaus, James Phillip; Marincel, Michelle K.

    2005-06-01

    This report is a review of open literature concerning threats including sabotage and theft related to fissile material transport in Japan. It is intended to aid Japanese officials in the development of a design basis threat. This threat includes the external threats of the terrorist, criminal, and extremist, and the insider threats of the disgruntled employee, the employee forced into cooperation via coercion, the psychotic employee, and the criminal employee. Examination of the external terrorist threat considers Japanese demographics, known terrorist groups in Japan, and the international relations of Japan. Demographically, Japan has a relatively homogenous population, both ethnically and religiously. Japan is a relatively peaceful nation, but its history illustrates that it is not immune to terrorism. It has a history of domestic terrorism and the open literature points to the Red Army, Aum Shinrikyo, Chukaku-Ha, and Seikijuku. Japan supports the United States in its war on terrorism and in Iraq, which may make Japan a target for both international and domestic terrorists. Crime appears to remain low in Japan; however sources note that the foreign crime rate is increasing as the number of foreign nationals in the country increases. Antinuclear groups' recent foci have been nuclear reprocessing technology, transportation of MOX fuel, and possible related nuclear proliferation issues. The insider threat is first defined by the threat of the disgruntled employee. This threat can be determined by studying the history of Japan's employment system, where Keiretsu have provided company stability and lifetime employment. Recent economic difficulties and an increase of corporate crime, due to sole reliability on the honor code, have begun to erode employee loyalty.

  18. Technical evaluation panel summary report. Ceramic and glass immobilization options fissile materials disposition program

    Energy Technology Data Exchange (ETDEWEB)

    Myers, B. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brummond, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Armantrout, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shaw, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jantzen, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jostons, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McKibben, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Strachan, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vienna, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1997-12-23

    This report documents the results of a technical evaluation of the merits of ceramic and glass immobilization forms for the disposition of surplus weapons-useable plutonium. The evaluation was conducted by a Technical Evaluation Panel (TEP), whose members were selected to cover a relevant range of scientific and technical expertise and represented each of the technical organizations involved in the Plutonium Immobilization Program. The TEP held a formal review at Lawrence Liver-more National Laboratory (LLNL) from July 2%August 1, 1997. Following this review, the TEP documented the review and its evaluation of the two immobilization technologies in this report to provide a technical basis for a recommendation by LLNL to the Department of Energy (DOE) for the preferred immobilization form. The comparison of the glass and ceramic forms and manufacturing processes was a tremendous challenge to the TEP. The two forms and their processes are similar in many ways. The TEP went to great effort to accurately assess what were, in many cases, fine details of the processes, unit operations, and the glass and ceramic forms themselves. The set of criteria used by the Fissile Materials Disposition Program (FMDP) in past screenings and down-selections was used to measure-the two options. One exception is that the TEP did not consider criteria that were largely nontechnical (namely international impact, public acceptance, and effects on other : DOE programs). The TEP' s measures and assessments are documented in detail. Care was taken to ensure that the data used were well documented and traceable to their source. Although no final conclusion regarding the preferred form was reached or explicitly stated in this report (this was not within the TEP' s charter), no "show stoppers" were identified for either form. Both forms appear capable of satisfying all the criteria, as interpreted by the TEP. The TEP identified a number of distinct and quantifiable differences between

  19. FATE OF FISSILE MATERIAL BOUND TO MONOSODIUM TITANATE DURING COOPER CATALYZED PEROXIDE OXIDATION OF TANK 48H WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K.

    2012-08-09

    At the Savannah River Site (SRS), Tank 48H currently holds approximately 240,000 gallons of slurry which contains potassium and cesium tetraphenylborate (TPB). A copper catalyzed peroxide oxidation (CCPO) reaction is currently being examined as a method for destroying the TPB present in Tank 48H. Part of the development of that process includes an examination of the fate of the Tank 48H fissile material which is adsorbed onto monosodium titanate (MST) particles. This report details results from experiments designed to examine the potential degradation of MST during CCPO processing and the subsequent fate of the adsorbed fissile material. Experiments were conducted to simulate the CCPO process on MST solids loaded with sorbates in a simplified Tank 48H simulant. Loaded MST solids were placed into the Tank 48H simplified simulant without TPB, and the experiments were then carried through acid addition (pH adjustment to 11), peroxide addition, holding at temperature (50 C) for one week, and finally NaOH addition to bring the free hydroxide concentration to a target concentration of 1 M. Testing was conducted without TPB to show the maximum possible impact on MST since the competing oxidation of TPB with peroxide was absent. In addition, the Cu catalyst was also omitted, which will maximize the interaction of H{sub 2}O{sub 2} with the MST; however, the results may be non-conservative assuming the Cu-peroxide active intermediate is more reactive than the peroxide radical itself. The study found that both U and Pu desorb from the MST when the peroxide addition begins, although to different extents. Virtually all of the U goes into solution at the beginning of the peroxide addition, whereas Pu reaches a maximum of {approx}34% leached during the peroxide addition. Ti from the MST was also found to come into solution during the peroxide addition. Therefore, Ti is present with the fissile in solution. After the peroxide addition is complete, the Pu and Ti are found to

  20. Nonproliferation and arms control assessment of weapons-usable fissile material storage and excess plutonium disposition alternatives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    This report has been prepared by the Department of Energy`s Office of Arms Control and Nonproliferation (DOE-NN) with support from the Office of Fissile Materials Disposition (DOE-MD). Its purpose is to analyze the nonproliferation and arms reduction implications of the alternatives for storage of plutonium and HEU, and disposition of excess plutonium, to aid policymakers and the public in making final decisions. While this assessment describes the benefits and risks associated with each option, it does not attempt to rank order the options or choose which ones are best. It does, however, identify steps which could maximize the benefits and mitigate any vulnerabilities of the various alternatives under consideration.

  1. Analyse of the potential of the high temperature reactor with respect to the use of fissile materials; Analyse des capacites des reacteurs a haute temperature sous l'aspect de l'utilisation des matieres fissiles

    Energy Technology Data Exchange (ETDEWEB)

    Damian, F

    2001-07-01

    The high temperature reactors fuel is made of micro-particles dispersed in a graphite matrix. This configuration makes it possible to reach high burnup, higher than 700 GWj/t. Thanks to the decoupling between the thermal and the neutronic behaviors in the core many types of fuels can be used. These characteristics give to HTR reactor very good capacities to burn fissile materials. This work was done in the frame of the evaluation of HTR capacities to enhance the value of the plutonium stocks. These stocks are currently composed of the irradiated fuels discharged from classical PWR or the dismantling of the nuclear weapons and represent a significant energy potential. These studies concluded that high cycles length can be reached whatever the plutonium quality is (from 50 % to 94 % of fissile plutonium). In addition, it was demonstrated that the moderator temperature coefficient becomes locally positive for highly burn fuel while the core global moderator temperature coefficient remained negative in the operation range of the reactor. A significant share of this work was first devoted to the setting of a modeling of the fuel element but also of the reactor's core with the codes of system SAPHYR. The whole of modeling was validated by reference calculations. This work of code assessment is justified by a preliminary work that showed that the classical calculation scheme used for PWR could not be transposed directly to HTR core. (author)

  2. 49 CFR 173.420 - Uranium hexafluoride (fissile, fissile excepted and non-fissile).

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Uranium hexafluoride (fissile, fissile excepted....420 Uranium hexafluoride (fissile, fissile excepted and non-fissile). (a) In addition to any other... non-fissile uranium hexafluoride must be offered for transportation as follows: (1) Before...

  3. 10 CFR 71.55 - General requirements for fissile material packages.

    Science.gov (United States)

    2010-01-01

    ... the special design features in paragraph (c) of this section, unless water leakage into or out of void... water were to leak into the containment system, or liquid contents were to leak out of the containment... the material; (2) Moderation by water to the most reactive credible extent; and (3) Close full...

  4. Fissile Material Disposition Program: Deep borehole disposal Facility PEIS date input report for immobilized disposal. Immobilized disposal of plutonium in coated ceramic pellets in grout with canisters. Version 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, A.M.; Shaffer, R.J.

    1996-01-15

    Following President Clinton`s Non-Proliferation Initiative, launched in September, 1993, an Interagency Working Group (IWG) was established to conduct a comprehensive review of the options for the disposition of weapons-usable fissile materials from nuclear weapons dismantlement activities in the United States and the former Soviet Union. The IWG review process will consider technical, nonproliferation, environmental budgetary, and economic considerations in the disposal of plutonium. The IWG is co-chaired by the White House Office of Science and Technology Policy and the National Security Council. The Department of Energy (DOE) is directly responsible for the management, storage, and disposition of all weapons-usable fissile material. The Department of Energy has been directed to prepare a comprehensive review of long-term options for Surplus Fissile Material (SFM) disposition, taking into account technical, nonproliferation, environmental, budgetary, and economic considerations.

  5. Material Transfer Agreement (MTA) | FNLCR

    Science.gov (United States)

    Material Transfer Agreements are appropriate for exchange of materials into or out of the Frederick National Labfor research or testing purposes, with no collaborative research by parties involving the materials.

  6. Quantitative Fissile Assay In Used Fuel Using LSDS System

    Directory of Open Access Journals (Sweden)

    Lee YongDeok

    2017-01-01

    Full Text Available A quantitative assay of isotopic fissile materials (U235, Pu239, Pu241 was done at Korea Atomic Energy Research Institute (KAERI, using lead slowing down spectrometer (LSDS. The optimum design of LSDS was performed based on economics, easy maintenance and assay effectiveness. LSDS system consists of spectrometer, neutron source, detection and control. LSDS system induces fissile fission and fast neutrons are collected at fission chamber. The detected signal has a direct relation to the mass of existing fissile isotopes. Many current commercial assay technologies have a limitation in direct application on isotopic fissile assay of spent fuel, except chemical analysis. In the designed system, the fissile assay model was setup and the correction factor for self-shield was obtained. The isotopic fissile content assay was performed by changing the content of Pu239. Based on the fuel rod, the isotopic content was consistent with ~2% uncertainty for Pu239. By applying the covering (neutron absorber, the effective shielding was obtained and the activation was calculated on the target. From the assay evaluation, LSDS technique is very powerful and direct to analyze the isotopic fissile content. LSDS is applicable for nuclear fuel cycle and spent fuel management for safety and economics. Additionally, an accurate fissile content will contribute to the international transparency and credibility on spent fuel.

  7. Quantitative Fissile Assay In Used Fuel Using LSDS System

    Science.gov (United States)

    Lee, YongDeok; Jeon, Ju Young; Park, Chang-Je

    2017-09-01

    A quantitative assay of isotopic fissile materials (U235, Pu239, Pu241) was done at Korea Atomic Energy Research Institute (KAERI), using lead slowing down spectrometer (LSDS). The optimum design of LSDS was performed based on economics, easy maintenance and assay effectiveness. LSDS system consists of spectrometer, neutron source, detection and control. LSDS system induces fissile fission and fast neutrons are collected at fission chamber. The detected signal has a direct relation to the mass of existing fissile isotopes. Many current commercial assay technologies have a limitation in direct application on isotopic fissile assay of spent fuel, except chemical analysis. In the designed system, the fissile assay model was setup and the correction factor for self-shield was obtained. The isotopic fissile content assay was performed by changing the content of Pu239. Based on the fuel rod, the isotopic content was consistent with 2% uncertainty for Pu239. By applying the covering (neutron absorber), the effective shielding was obtained and the activation was calculated on the target. From the assay evaluation, LSDS technique is very powerful and direct to analyze the isotopic fissile content. LSDS is applicable for nuclear fuel cycle and spent fuel management for safety and economics. Additionally, an accurate fissile content will contribute to the international transparency and credibility on spent fuel.

  8. Muon Tomography Algorithms for Fissile Nuclear Materials Detection%宇宙射线μ子探测裂变核材料的成像算法

    Institute of Scientific and Technical Information of China (English)

    王烈铭; 王红艳; 刘志英; 杨宏伟; 庞洪超

    2011-01-01

    宇宙射线μ子探测作为一种清洁源、深穿透、真正识别裂变核材料的新方法正在世界范围内日益受到重视,我国也在反恐领域开展此项研究,论文介绍了研究工作中图像重建算法(PoCA算法、期望最大化算法)以及算法模拟实验结果和分析,模拟结果初步证明了宇宙线μ子进行特殊核材料检测的可行性以及图像重建算法的有效性.%Muon Tomography is a novel technique which exploits the multiple coulomb scattering of these particles for nondestructive inspection without the use of artificial radiation. It describes the concept and theory of cosmic - ray muon tomography, and discuss preliminary and advanced reconstruction algorithms ( PoCA algorithm and MLS - EM algorithm) .which take advantage of the scattering angle. Our algorithms are validated with simulation experimental demonstrations. Based upon the results from simulations, we conclude that muon radiography can be useful for detecting fissile nuclear materials.

  9. Los Alamos National Laboratory summary plan to fabricate mixed oxide lead assemblies for the fissile material disposition program

    Energy Technology Data Exchange (ETDEWEB)

    Buksa, J.J.; Eaton, S.L.; Trellue, H.R.; Chidester, K.; Bowidowicz, M.; Morley, R.A.; Barr, M.

    1997-12-01

    This report summarizes an approach for using existing Los Alamos National Laboratory (Laboratory) mixed oxide (MOX) fuel-fabrication and plutonium processing capabilities to expedite and assure progress in the MOX/Reactor Plutonium Disposition Program. Lead Assembly MOX fabrication is required to provide prototypic fuel for testing in support of fuel qualification and licensing requirements. It is also required to provide a bridge for the full utilization of the European fabrication experience. In part, this bridge helps establish, for the first time since the early 1980s, a US experience base for meeting the safety, licensing, safeguards, security, and materials control and accountability requirements of the Department of Energy and Nuclear Regulatory Commission. In addition, a link is needed between the current research and development program and the production of disposition mission fuel. This link would also help provide a knowledge base for US regulators. Early MOX fabrication and irradiation testing in commercial nuclear reactors would provide a positive demonstration to Russia (and to potential vendors, designers, fabricators, and utilities) that the US has serious intent to proceed with plutonium disposition. This report summarizes an approach to fabricating lead assembly MOX fuel using the existing MOX fuel-fabrication infrastructure at the Laboratory.

  10. DEVELOPMENT OF LEAD SLOWING DOWN SPECTROMETER FOR ISOTOPIC FISSILE ASSAY

    Directory of Open Access Journals (Sweden)

    SANG JOON AHN

    2014-12-01

    Full Text Available A lead slowing down spectrometer (LSDS is under development for analysis of isotopic fissile material contents in pyro-processed material, or spent fuel. Many current commercial fissile assay technologies have a limitation in accurate and direct assay of fissile content. However, LSDS is very sensitive in distinguishing fissile fission signals from each isotope. A neutron spectrum analysis was conducted in the spectrometer and the energy resolution was investigated from 0.1eV to 100keV. The spectrum was well shaped in the slowing down energy. The resolution was enough to obtain each fissile from 0.2eV to 1keV. The detector existence in the lead will disturb the source neutron spectrum. It causes a change in resolution and peak amplitude. The intense source neutron production was designed for ∼E12 n's/sec to overcome spent fuel background. The detection sensitivity of U238 and Th232 fission chamber was investigated. The first and second layer detectors increase detection efficiency. Thorium also has a threshold property to detect the fast fission neutrons from fissile fission. However, the detection of Th232 is about 76% of that of U238. A linear detection model was set up over the slowing down neutron energy to obtain each fissile material content. The isotopic fissile assay using LSDS is applicable for the optimum design of spent fuel storage to maximize burnup credit and quality assurance of the recycled nuclear material for safety and economics. LSDS technology will contribute to the transparency and credibility of pyro-process using spent fuel, as internationally demanded.

  11. DESIGN OF LSDS FOR ISOTOPIC FISSILE ASSAY IN SPENT FUEL

    Directory of Open Access Journals (Sweden)

    YONGDEOK LEE

    2013-12-01

    Full Text Available A future nuclear energy system is being developed at Korea Atomic Energy Research Institute (KAERI, the system involves a Sodium Fast Reactor (SFR linked with the pyro-process. The pyro-process produces a source material to fabricate a SFR fuel rod. Therefore, an isotopic fissile content assay is very important for fuel rod safety and SFR economics. A new technology for an analysis of isotopic fissile content has been proposed using a lead slowing down spectrometer (LSDS. The new technology has several features for a fissile analysis from spent fuel: direct isotopic fissile assay, no background interference, and no requirement from burnup history information. Several calculations were done on the designed spectrometer geometry: detection sensitivity, neutron energy spectrum analysis, neutron fission characteristics, self shielding analysis, and neutron production mechanism. The spectrum was well organized even at low neutron energy and the threshold fission chamber was a proper choice to get prompt fast fission neutrons. The characteristic fission signature was obtained in slowing down neutron energy from each fissile isotope. Another application of LSDS is for an optimum design of the spent fuel storage, maximization of the burnup credit and provision of the burnup code correction factor. Additionally, an isotopic fissile content assay will contribute to an increase in transparency and credibility for the utilization of spent fuel nuclear material, as internationally demanded.

  12. Energy transfer in nanostructured materials

    Science.gov (United States)

    Haughn, Chelsea

    Energy transport and loss are critical to the performance of optoelectronic devices such as photovoltaics and terahertz imaging devices. Nanostructured materials provide many opportunities to tailor transport and loss parameters for specific device applications. However, it has been very difficult to correlate specific nanoscale structural parameters with changes in these performance metrics. I report the development of new ways of using time-resolved photoluminescence (TRPL) to probe charge and energy transport and loss dynamics. These techniques are applied to several types of nanostructured materials, including bulk semiconductors with defects, self-assembled quantum dots and colloidal quantum dots. First, GaAs/InP double heterostructures grown via metal organic chemical vapor deposition (MOCVD) were characterized with TRPL. TRPL is typically used to extract minority carrier lifetimes, but we discovered that the measured lifetime depended critically on the intensity of the exciting laser. We developed a Shockley-Read-Hall model to extract trap state densities from intensity-dependent TRPL measurements. Second, we characterized energy and charge transfer between InAs quantum dots and ErAs nanoinclusions within III-V heterostructures. Using intensity- and temperature-dependent TRPL, we confirmed tunneling as the dominant mechanism of charge transport and characterized the electronic structure of the ErAs nanoparticles. Finally, we characterized energy transport in colloidal quantum dot cascade structures. These cascade structures utilize Forster Resonance Energy Transfer and trap state recycling to funnel excitons from donor layers to acceptor layers and suggest a promising method for avoiding losses associated with surface trap states. Collectively, the analysis of these disparate material types advances our understanding of energy dynamics in nanostructured materials and improves our ability to design the next generation of photovoltaic and optoelectronic

  13. Detecting lateral genetic material transfer

    CERN Document Server

    Calderón, C; Mireles, V; Miramontes, P

    2012-01-01

    The bioinformatical methods to detect lateral gene transfer events are mainly based on functional coding DNA characteristics. In this paper, we propose the use of DNA traits not depending on protein coding requirements. We introduce several semilocal variables that depend on DNA primary sequence and that reflect thermodynamic as well as physico-chemical magnitudes that are able to tell apart the genome of different organisms. After combining these variables in a neural classificator, we obtain results whose power of resolution go as far as to detect the exchange of genomic material between bacteria that are phylogenetically close.

  14. Fissile mass estimation by pulsed neutron source interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Israelashvili, I., E-mail: israelashvili@gmail.com [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel); Dubi, C.; Ettedgui, H.; Ocherashvili, A. [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel); Pedersen, B. [Nuclear Security Unit, Institute for Transuranium Elements, Joint Research Centre, Via E. Fermi, 2749, 21027 Ispra (Italy); Beck, A. [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel); Roesgen, E.; Crochmore, J.M. [Nuclear Security Unit, Institute for Transuranium Elements, Joint Research Centre, Via E. Fermi, 2749, 21027 Ispra (Italy); Ridnik, T.; Yaar, I. [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel)

    2015-06-11

    Passive methods for detecting correlated neutrons from spontaneous fissions (e.g. multiplicity and SVM) are widely used for fissile mass estimations. These methods can be used for fissile materials that emit a significant amount of fission neutrons (like plutonium). Active interrogation, in which fissions are induced in the tested material by an external continuous source or by a pulsed neutron source, has the potential advantages of fast measurement, alongside independence of the spontaneous fissions of the tested fissile material, thus enabling uranium measurement. Until recently, using the multiplicity method, for uranium mass estimation, was possible only for active interrogation made with continues neutron source. Pulsed active neutron interrogation measurements were analyzed with techniques, e.g. differential die away analysis (DDA), which ignore or implicitly include the multiplicity effect (self-induced fission chains). Recently, both, the multiplicity and the SVM techniques, were theoretically extended for analyzing active fissile mass measurements, made by a pulsed neutron source. In this study the SVM technique for pulsed neutron source is experimentally examined, for the first time. The measurements were conducted at the PUNITA facility of the Joint Research Centre in Ispra, Italy. First promising results, of mass estimation by the SVM technique using a pulsed neutron source, are presented.

  15. [Technology transfer of building materials by ECOMAT

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This report discusses the plan for technology transfer of building materials developed by ECOMAT to the commercial private sector. Some of the materials are briefly discussed like foams, fiber reinforcement, fly ash development, and polymer fillers.

  16. Fissile solution dynamics: Student research

    Energy Technology Data Exchange (ETDEWEB)

    Hetrick, D.L.

    1994-09-01

    There are two research projects in criticality safety at the University of Arizona: one in dynamic simulation of hypothetical criticality accidents in fissile solutions, and one in criticality benchmarks using transport theory. We have used the data from nuclear excursions in KEWB, CRAC, and SILENE to help in building models for solution excursions. An equation of state for liquids containing gas bubbles has been developed and coupled to point-reactor dynamics in an attempt to predict fission rate, yield, pressure, and kinetic energy. It appears that radiolytic gas is unimportant until after the first peak, but that it does strongly affect the shape of the subsequent power decrease and also the dynamic pressure.

  17. Heat transfer in multi-phase materials

    CERN Document Server

    Öchsner, Andreas

    2011-01-01

    This book provides a profound understanding, which physical processes and mechanisms cause the heat transfer in composite and cellular materials. It shows models for all important classes of composite materials and introduces into the latest advances. In three parts, the book covers Composite Materials (Part A), Porous and Cellular Materials (Part B) and the appearance of a conjoint solid phase and fluid aggregate (Part C).

  18. Development of an Air Transport Type A Fissile Package

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, P.; Ebert, K.

    2011-07-13

    This paper presents the summary of testing by the Savannah River National Laboratory (SRNL) to support development of a light weight (<140 lbs) air transport qualified Type A Fissile Packaging. The package design incorporates features and materials specifically designed to minimize packaging weight. The light weight package is being designed to provide confinement to the contents when subjected to the normal and hypothetical conditions required of an air transportable Type A Fissile radioactive material shipping package. The objective of these tests was to provide design input to the final design for the LORX Type A Fissile Air Transport Packaging when subjected to the performance requirements of the drop, crush and puncture probe test of 10CFR71. The post test evaluation of the prototype packages indicates that all of the tested designs would satisfactorily confine the content within the packaging. The differences in the performance of the prototypes varied significantly depending on the core materials and their relative densities. Information gathered from these tests is being used to develop the final design for the Department of Homeland Security.

  19. Reflectance Transfer for Material Editing and Relighting

    Directory of Open Access Journals (Sweden)

    Adrian Hilton

    2010-10-01

    Full Text Available We present a new approach to diffuse reflectance estimation for dynamic scenes. Non-parametric image statistics are used to transfer reflectance properties from a static example set to a dynamic image sequence. The approach allows diffuse reflectance estimation for surface materials with inhomogeneous appearance, such as those which commonly occur with patterned or textured clothing. Material editing is also possible by transferring edited reflectance properties. Material reflectance properties are initially estimated from static images of the subject under multiple directional illuminations using photometric stereo. The estimated reflectance together with the corresponding image under uniform ambient illumination form a prior set of reference material observations. Material reflectance properties are then estimated for video sequences of a moving person captured under uniform ambient illumination by matching the observed local image statistics to the reference observations. Results demonstrate that the transfer of reflectance properties enables estimation of the dynamic surface normals and subsequent relighting combined with material editing. This approach overcomes limitations of previous work on material transfer and relighting of dynamic scenes which was limited to surfaces with regions of homogeneous reflectance. We evaluate our approach for relighting 3D model sequences reconstructed from multiple view video. Comparison to previous model relighting demonstrates improved reproduction of detailed texture and shape dynamics.

  20. Response to 'A comment on 'Signatures of fissile materials:High-energy gamma rays following fission,' by Zeev B. Alfassi'

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Eric B.; Prussin, Stanley G.; Larimer, Ruth-Mary; Shugart, Howard; Browne, Edgardo; Smith, Alan R.; McDonald, Richard J.; Nitsche, Heino; Gupta, Puja; Frank, Michael I.; Gosnell, Thomas B.

    2004-06-03

    Prof. Alfassi has pointed out that radionuclides that are not fission products, but which emit {gamma} rays with energies E{sub {gamma}} > 3 MeV, can be produced by neutron irradiation. He suggested that the decays of such activation products would interfere with the identification of fissionable materials. However, the combination of the energy spectrum and the temporal variation of the fission product gamma rays can be used to distinguish fissionable material from other nuclides. The activation of nuclides that could produce interferences will depend upon the specifics of the cargo and, possibly, the local surroundings. As discussed in our original publication, in addition to the steel that Prof. Alfassi referred to in his Comment, we studied the activation of wood, polyethylene, aluminum, and sandstone. Activation by thermal neutrons will always occur, and Prof. Alfassi correctly points out that nuclides such as {sup 49}Ca and {sup 37}S can be formed in this way. These nuclides are representative of most potential interferences. Both {sup 48}Ca and {sup 36}S have very low isotopic abundances (0.187% and 0.02%, respectively) and small thermal neutron capture cross sections (0.20 barns and 0.98 barns, respectively). In addition, their half lives are more than an order of magnitude longer than the gross average observed from the fission products, and more than two orders of magnitude longer than the lifetimes of the shorter-lived fission products that contribute significantly to the total intensity in the energy range of interest. These differences make it possible to distinguish between fission products and thermal neutron activation products. Prof. Alfassi also pointed out that interferences, of which {sup 16}N is likely to be the most important, can be produced by fast neutron reactions. (As described in our original publication, we did not use a 14 MeV generator in our work.) Fortunately, a judicious choice of the source neutron energy can limit the extent of

  1. 10 CFR 76.83 - Transfer of radioactive material.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Transfer of radioactive material. 76.83 Section 76.83... Transfer of radioactive material. (a) The Corporation may not transfer radioactive material except as... paragraphs (c) and (d) of this section, the Corporation may transfer radioactive material: (1) From...

  2. Electromagnetic Heat Transfer in Artificial Materials

    Science.gov (United States)

    Woods, Lilia; Drosdoff, David; Phan, Anh

    2014-03-01

    Electromagnetic energy exchange has found promising new opportunities by greatly enhancing the heat transfer between bodies via radiation in the near-field regime. The greatest heat transfer occurs when the bodies support surface plasmons or polaritons that share the same resonant frequency. It has been shown, however, that 2-D materials such as graphene can have their surface plasmons tuned by modifying the chemical potential and temperature. This allows for tuning its resonance with other systems. In this talk, we investigated the electromagnetic radiation in metamaterials characterized by a strong magnetic response. We study theoretically Pendry-like and magnetically active metamaterial/graphene composites. The possibility for enhancing or inhibiting the heat transfer via the graphene properties is investigated.

  3. Sensing Fissile Materials at Long Range

    Science.gov (United States)

    2016-04-01

    production . Cyclotron  technology  has  been developed over many decades, and today it is considered a mature  technology .     The present approach for making...the water or its bydroducts (oxygen ions, atoms and  water clusters) and  ammonia  and its by  products , (nitrogen, ammonium clusters, …)  would not...HDTRA1-09-1-0042 Leslie Bromberg et al. Prepared by: Massachusetts Institute of Technology 77

  4. Criteria for onsite transfers of radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Opperman, E.K.; Jackson, E.J.; Eggers, A.G.

    1992-12-31

    A general description of the requirements for making onsite transfers of radioactive material is provided in Chapter 2, along with the required sequencey of activities. Various criteria for package use are identified in Chapters 3-13. These criteria provide protection against undue radiation exposure. Package shielding, containment, and surface contamination requirements are established. Criteria for providing criticality safety are enumerated in Chapter 6. Criteria for providing hazards information are established in Chapter 13. A glossary is provided.

  5. Laser induced forward transfer of soft materials

    Science.gov (United States)

    Palla-Papavlu, A.; Dinca, V.; Luculescu, C.; Shaw-Stewart, J.; Nagel, M.; Lippert, T.; Dinescu, M.

    2010-12-01

    A strong research effort is presently aimed at patterning methodologies for obtaining controlled defined micrometric polymeric structures for a wide range of applications, including electronics, optoelectronics, sensors, medicine etc. Lasers have been identified as appropriate tools for processing of different materials, such as ceramics and metals, but also for soft, easily damageable materials (biological compounds and polymers). In this work we study the dynamics of laser induced forward transfer (LIFT) with a gap between the donor and the receiver substrates, which is the basis for possible applications that require multilayer depositions with high spatial resolution.

  6. CarbAl Heat Transfer Material

    Science.gov (United States)

    Fink, Richard

    2015-01-01

    The increasing use of power electronics, such as high-current semiconductor devices and modules, within space vehicles is driving the need to develop specialty thermal management materials in both the packaging of these discrete devices and the packaging of modules consisting of these device arrays. Developed by Applied Nanotech, Inc. (ANI), CarbAl heat transfer material is uniquely characterized by its low density, high thermal diffusivity, and high thermal conductivity. Its coefficient of thermal expansion (CTE) is similar to most power electronic materials, making it an effective base plate substrate for state-of-the-art silicon carbide (SiC) super junction transistors. The material currently is being used to optimize hybrid vehicle inverter packaging. Adapting CarbAl-based substrates to space applications was a major focus of the SBIR project work. In Phase I, ANI completed modeling and experimentation to validate its deployment in a space environment. Key parameters related to cryogenic temperature scaling of CTE, thermal conductivity, and mechanical strength. In Phase II, the company concentrated on improving heat sinks and thermally conductive circuit boards for power electronic applications.

  7. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    Energy Technology Data Exchange (ETDEWEB)

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in

  8. Working with the NCL - Material Transfer Agreement - Nanotechnology Characterization Laboratory

    Science.gov (United States)

    To share and safeguard Research Material, intellectual property and proprietary information, the NCL's interaction with extramural researchers and vendors will normally be conducted under a Material Transfer Agreement (MTA).

  9. 49 CFR 173.477 - Approval of packagings containing greater than 0.1 kg of non-fissile or fissile-excepted uranium...

    Science.gov (United States)

    2010-10-01

    ... kg of non-fissile or fissile-excepted uranium hexafluoride. 173.477 Section 173.477 Transportation... non-fissile or fissile-excepted uranium hexafluoride. (a) Each offeror of a package containing more than 0.1 kg of uranium hexafluoride must maintain on file for at least one year after the...

  10. TYPE A FISSILE PACKAGING FOR AIR TRANSPORT PROJECT OVERVIEW

    Energy Technology Data Exchange (ETDEWEB)

    Eberl, K.; Blanton, P.

    2013-10-11

    This paper presents the project status of the Model 9980, a new Type A fissile packaging for use in air transport. The Savannah River National Laboratory (SRNL) developed this new packaging to be a light weight (<150-lb), drum-style package and prepared a Safety Analysis for Packaging (SARP) for submission to the DOE/EM. The package design incorporates unique features and engineered materials specifically designed to minimize packaging weight and to be in compliance with 10CFR71 requirements. Prototypes were fabricated and tested to evaluate the design when subjected to Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC). An overview of the design details, results of the regulatory testing, and lessons learned from the prototype fabrication for the 9980 will be presented.

  11. Historic transfer of forest reproductive material in the Nordic region

    DEFF Research Database (Denmark)

    Myking, Tor; Rusanen, Mari; Steffenrem, Arne

    2016-01-01

    Large-scale transfer of reproductive material is a common phenomenon in forestry and is not only limited to recent history. Here we review the historical transfer of forest reproductive material (FRM) in Fennoscandia, the directions, their drivers, and the reported consequences for adaptation...

  12. Fissile and non-fissile element separation in concrete radioactive waste drums using the SIMPHONIE method

    Energy Technology Data Exchange (ETDEWEB)

    Jallu, F. E-mail: fanny.jallu@cea.fr; Lyoussi, A.; Passard, C.; Payan, E.; Recroix, H.; Nurdin, G.; Buisson, A.; Allano, J

    2001-07-01

    The simultaneous photon and neutron interrogation experiment (SIMPHONIE) method, applied to radioactive waste drum characterization, has already been treated in [F. Jallu, A. Lyoussi, C. Passard, E. Payan, H. Recroix, G. Nurdin, A. Buisson, J. Allano, Nucl. Instr. and Meth. B 170 (2000) 489]. First experimental results carried out with U and Pu bare samples were presented, that showed the feasibility of quantifying fissile ({sup 235}U, {sup 239,241}Pu, ...) and non-fissile ({sup 234,236,238}U, {sup 238,240}Pu, ...) elements separately in only one measurement, using both active neutron interrogation and induced photofission interrogation techniques simultaneously. This paper presents new experimental results carried out with U samples embedded in a concrete matrix. These results have been obtained using the DGA/ETCA MiniLinatron pulsed linear electron accelerator located at Arcueil, France. Mass detection limits of less than 2 g of matter have been obtained with the preliminary setup used in these experiments.

  13. Fission dynamics with systems of intermediate fissility

    Indian Academy of Sciences (India)

    E Vardaci; A Di Nitto; P N Nadtochy; A Brondi; G La Rana; R Moro; M Cinausero; G Prete; N Gelli; E M Kozulin; G N Knyazheva; I M Itkis

    2015-08-01

    A 4 light charged particle spectrometer, called 8 LP, is in operation at the Laboratori Nazionali di Legnaro, Italy, for studying reaction mechanisms in low-energy heavy-ion reactions. Besides about 300 telescopes to detect light charged particles, the spectrometer is also equipped with an anular PPAC system to detect evaporation residues and a two-arm time-of-flight spectrometer to detect fission fragments. The spectrometer has been used in several fission dynamics studies using as a probe light charged particles in the fission and evaporation residues (ER) channels. This paper proposes a journey within some open questions about the fission dynamics and a review of the main results concerning nuclear dissipation and fission time-scale obtained from several of these studies. In particular, the advantages of using systems of intermediate fissility will be discussed.

  14. Heat transfer in Rockwool modelling and method of measurement. Modelling radiative heat transfer in fibrous materials

    Energy Technology Data Exchange (ETDEWEB)

    Dyrboel, Susanne

    1998-05-01

    Fibrous materials are some of the most widely used materials for thermal insulation. In this project the focus of interest has been on fibrous materials for building application. Interest in improving the thermal properties of insulation materials is increasing as legislation is being tightened to reduce the overall energy consumption. A knowledge of the individual heat transfer mechanisms - whereby heat is transferred within a particular material is an essential tool to improve continuously the thermal properties of the material. Heat is transferred in fibrous materials by four different transfer mechanisms: conduction through air, conduction through fibres, thermal radiation and convection. In a particular temperature range the conduction through air can be regarded as a constant, and conduction through fibres is an insignificant part of the total heat transfer. Radiation, however, constitutes 25-40% of the total heat transfer in light fibrous materials. In Denmark and a number of other countries convection in fibrous materials is considered as non-existent when calculating heat transmission as well as when designing building structures. Two heat transfer mechanisms have been the focus of the current project: radiation heat transfer and convection. The radiation analysis serves to develop a model that can be used in further work to gain a wider knowledge of the way in which the morphology of the fibrous material, i.e. fibre diameter distribution, fibre orientation distribution etc., influences the radiation heat transfer under different conditions. The convection investigation serves to examine whether considering convection as non-existent is a fair assumption to use in present and future building structures. The assumption applied in practically is that convection makes a notable difference only in very thick insulation, at external temperatures below -20 deg. C, and at very low densities. For lager thickness dimensions the resulting heat transfer through the

  15. Fourier analysis of conductive heat transfer for glazed roofing materials

    Energy Technology Data Exchange (ETDEWEB)

    Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2014-07-10

    For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.

  16. Theory of light transfer in food and biological materials

    Science.gov (United States)

    In this chapter, we first define the basic radiometric quantities that are needed for describing light propagation in food and biological materials. Radiative transfer theory is then derived, according to the principle of the conservation of energy. Because the radiative transfer theory equation is ...

  17. Neutron multiplication method for measuring the amount of fissile isotopes in the spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Chwaszczewski, S.; Pytel, K. [Institute of Atomic Energy, 05-400 Otwock-Swierk (Poland); Abou-Zaid, A.A. [Atomic Energy Authority, 13759 Cairo (Egypt)

    2001-07-01

    A nondestructive assay method for determination the amount of fissile materials content along the vertical axis of irradiated fuel is presented. The method, called neutron multiplication method, can be realized as passive measurement technique and the active one. The Monte Carlo code has been used for the neutron transport simulation and optimization of the measuring equipment geometry. On the basis of these results, a preliminary experimental stand for MARIA reactor fuel investigation has been designed and the measurements have been performed for the fresh fuel and the fuel mock-up. Based upon both numerical and experimental simulations, an ultimate measuring stand has been designed and the measurements for MARIA spent fuel assemblies as well as for the fresh fuel and mock-up of the fuel have been carried out. The results showed that the active neutron technique does not provide sufficient resolution of the distribution of the amount of fissile materials. But rather can be applied for measurement of the absolute value. The passive one can be used to restore the distribution of the bum-up and the amount of fissile materials along the axial length of the spent fuel assembly. (author)

  18. Transfer function concept for ultrasonic characterization of material microstructures

    Science.gov (United States)

    Vary, A.; Kautz, H. E.

    1986-01-01

    The approach given depends on treating material microstructures as elastomechanical filters that have analytically definable transfer functions. These transfer functions can be defined in terms of the frequency dependence of the ultrasonic attenuation coefficient. The transfer function concept provides a basis for synthesizing expressions that characterize polycrystalline materials relative to microstructural factors such as mean grain size, grain-size distribution functions, and grain boundary energy transmission. Although the approach is nonrigorous, it leads to a rational basis for combining the previously mentioned diverse and fragmented equations for ultrasonic attenuation coefficients.

  19. Material transfer agreements : A review of modes and impacts

    NARCIS (Netherlands)

    Rodriguez, V.

    2009-01-01

    Sharing or exchanging research material is typically formalised through material transfer agreements. The aim of this article is to put into critical perspective the empirical findings on modes and impacts of these agreements vis-a-vis commonly accepted concerns formulated in a Mertonian fashion for

  20. Material Transfer Agreements: A Review of Modes and Impacts

    NARCIS (Netherlands)

    Rodriguez, Victor

    2009-01-01

    Sharing or exchanging research material is typically formalised through material transfer agreements. The aim of this article is to put into critical perspective the empirical findings on modes and impacts of these agreements vis--vis commonly accepted concerns formulated in a Mertonian fashion for

  1. Operational Characteristics of an Accelerator Driven Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-28

    Operational characteristics represent the set of responses that a nuclear system exhibits during normal operation. Operators rely on this behavior to assess the status of the system and to predict the consequences of off-normal events. These characteristics largely refer to the relationship between power and system operating conditions. The static and dynamic behavior of a chain-reacting system, operating at sufficient power, is primarily governed by reactivity effects. The science of reactor physics has identified and evaluated a number of such effects, including Doppler broadening and shifts in the thermal neutron spectrum. Often these reactivity effects are quantified in the form of feedback coefficients that serve as coupling coefficients relating the neutron population and the physical mechanisms that drive reactivity effects, such as fissile material temperature and density changes. The operational characteristics of such nuclear systems usually manifest themselves when perturbations between system power (neutron population) and system operating conditions arise. Successful operation of such systems require the establishment of steady equilibrium conditions. However, prior to obtaining the desired equilibrium (steady-state) conditions, an approach from zero-power (startup) must occur. This operational regime may possess certain limiting system conditions that must be maintained to achieve effective startup. Once steady-state is achieved, a key characteristic of this operational regime is the level of stability that the system possesses. Finally, a third operational regime, shutdown, may also possess limiting conditions of operation that must be maintained. This report documents the operational characteristics of a “generic” Accelerator Driven Fissile Solution (ADFS) system during the various operational regimes of startup, steady-state operation, and shutdown. Typical time-dependent behavior for each operational regime will be illustrated, and key system

  2. Implementation of the Fissile Mass Flow Monitor Source Verification and Confirmation

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, Taner [ORNL; March-Leuba, Jose A [ORNL; Powell, Danny H [ORNL; Nelson, Dennis [Sandia National Laboratories (SNL); Radev, Radoslav [Lawrence Livermore National Laboratory (LLNL)

    2007-12-01

    This report presents the verification procedure for neutron sources installed in U.S. Department of Energy equipment used to measure fissile material flow. The Fissile Mass Flow Monitor (FMFM) equipment determines the {sup 235}U fissile mass flow of UF{sub 6} gas streams by using {sup 252}Cf neutron sources for fission activation of the UF{sub 6} gas and by measuring the fission products in the flow. The {sup 252}Cf sources in each FMFM are typically replaced every 2 to 3 years due to their relatively short half-life ({approx} 2.65 years). During installation of the new FMFM sources, the source identity and neutronic characteristics provided by the manufacturer are verified with the following equipment: (1) a remote-control video television (RCTV) camera monitoring system is used to confirm the source identity, and (2) a neutron detection system (NDS) is used for source-strength confirmation. Use of the RCTV and NDS permits remote monitoring of the source replacement process and eliminates unnecessary radiation exposure. The RCTV, NDS, and the confirmation process are described in detail in this report.

  3. Microassembly of Heterogeneous Materials using Transfer Printing and Thermal Processing.

    Science.gov (United States)

    Keum, Hohyun; Yang, Zining; Han, Kewen; Handler, Drew E; Nguyen, Thong Nhu; Schutt-Aine, Jose; Bahl, Gaurav; Kim, Seok

    2016-07-18

    Enabling unique architectures and functionalities of microsystems for numerous applications in electronics, photonics and other areas often requires microassembly of separately prepared heterogeneous materials instead of monolithic microfabrication. However, microassembly of dissimilar materials while ensuring high structural integrity has been challenging in the context of deterministic transferring and joining of materials at the microscale where surface adhesion is far more dominant than body weight. Here we present an approach to assembling microsystems with microscale building blocks of four disparate classes of device-grade materials including semiconductors, metals, dielectrics, and polymers. This approach uniquely utilizes reversible adhesion-based transfer printing for material transferring and thermal processing for material joining at the microscale. The interfacial joining characteristics between materials assembled by this approach are systematically investigated upon different joining mechanisms using blister tests. The device level capabilities of this approach are further demonstrated through assembling and testing of a microtoroid resonator and a radio frequency (RF) microelectromechanical systems (MEMS) switch that involve optical and electrical functionalities with mechanical motion. This work opens up a unique route towards 3D heterogeneous material integration to fabricate microsystems.

  4. Microassembly of Heterogeneous Materials using Transfer Printing and Thermal Processing

    Science.gov (United States)

    Keum, Hohyun; Yang, Zining; Han, Kewen; Handler, Drew E.; Nguyen, Thong Nhu; Schutt-Aine, Jose; Bahl, Gaurav; Kim, Seok

    2016-07-01

    Enabling unique architectures and functionalities of microsystems for numerous applications in electronics, photonics and other areas often requires microassembly of separately prepared heterogeneous materials instead of monolithic microfabrication. However, microassembly of dissimilar materials while ensuring high structural integrity has been challenging in the context of deterministic transferring and joining of materials at the microscale where surface adhesion is far more dominant than body weight. Here we present an approach to assembling microsystems with microscale building blocks of four disparate classes of device-grade materials including semiconductors, metals, dielectrics, and polymers. This approach uniquely utilizes reversible adhesion-based transfer printing for material transferring and thermal processing for material joining at the microscale. The interfacial joining characteristics between materials assembled by this approach are systematically investigated upon different joining mechanisms using blister tests. The device level capabilities of this approach are further demonstrated through assembling and testing of a microtoroid resonator and a radio frequency (RF) microelectromechanical systems (MEMS) switch that involve optical and electrical functionalities with mechanical motion. This work opens up a unique route towards 3D heterogeneous material integration to fabricate microsystems.

  5. CFD ANALYSIS FOR HEAT TRANSFER BETWEEN COPPER ENCAPSULATED PHASE CHANGE MATERIAL AND HEAT TRANSFER FLUID

    Directory of Open Access Journals (Sweden)

    M.Premkumar

    2013-03-01

    Full Text Available Heat transfer plays an important role in the enhancement of thermal energy storage in phase change material (PCM. The effective utilization of solar thermal energy can be obtained by proper storage of that energy. There are various techniques for the enhancement solar thermal storage in phase change material such as introductionof wire brushes, honey comb structure, fins and packed bed storage. In this study the analysis of heat transfer between PCM and heat transfer fluids (HTF with Spherical and cylindrical finned encapsulations made of copper are done using computational fluid dynamic (CFD analysis software GAMBIT and Fluent 6.2. The analysis is done in two modes as charging and discharging. During the charging mode the input is given in terms of temperature to the heat transfer fluid and the amount of heat transfer inside the PCM encapsulation is taken as output. During the discharging process the output temperature in the PCM is given as input and the amount of heat transferred to the heat transfer fluid is noted. The results from CFD analysis conclude that the heat transfer is more in finned encapsulations than that of without finned encapsulations and the copper sphere with fins is considered to be the best out of all other encapsulations.

  6. Integrated Charge Transfer in Organic Ferroelectrics for Flexible Multisensing Materials.

    Science.gov (United States)

    Xu, Beibei; Ren, Shenqiang

    2016-09-01

    The ultimate or end point of functional materials development is the realization of strong coupling between all energy regimes (optical, electronic, magnetic, and elastic), enabling the same material to be utilized for multifunctionalities. However, the integration of multifunctionalities in soft materials with the existence of various coupling is still in its early stage. Here, the coupling between ferroelectricity and charge transfer by combining bis(ethylenedithio)tetrathiafulvalene-C60 charge-transfer crystals with ferroelectric polyvinylidene fluoride polymer matrix is reported, which enables external stimuli-controlled polarization, optoelectronic and magnetic field sensing properties. Such flexible composite films also display a superior strain-dependent capacitance and resistance change with a giant piezoresistance coefficient of 7.89 × 10(-6) Pa(-1) . This mutual coupled material with the realization of enhanced couplings across these energy domains opens up the potential for multisensing applications.

  7. DOE NCSP Review of TRUPACT-II/HalfPACT Fissile Limits

    Energy Technology Data Exchange (ETDEWEB)

    Goluoglu, S.

    2002-03-28

    The U.S. Department of Energy (DOE) Environmental Management (EM) Office of Nuclear Material & Spent Fuel, EM-21, tasked the CSSG to perform a scoping study to determine the feasibility of increasing the fissile mass loading limits for specified TRUPACT-II and HalfPACT packages and containers. The results of the scoping study may provide insights and technical guidance for establishing fissile mass loading limits at waste generator sites and at the waste repository. The goal is to reduce costs of transporting fissile material to the WIPP from EM's various closure sites. This report documents the results of the scoping study and demonstrates that it is feasible to significantly increase the fissile mass loading limits in the TRUPACT-II and HalfPACT packages and containers. Depending upon the particular payload containers used, the number of shipments to WIPP could be reduced by at least a factor of 2 and as much as a factor of 16 and the number of total payload containers required ''down-hole'' at WIPP could be reduced by at least a factor of 2 and as much as about 6. These cost savings result simply from applying a more realistic criticality analysis model rather than the very conservative, hypothetical, bounding analysis used to support the existing fissile mass loading limits. However, the applications of existing and developmental computational tools, nuclear data, and experiments from the DOE Nuclear Criticality Safety Program have the potential to further reduce transportation and disposal container costs on the order of 7% to 17%. It is suggested that EM proceed with an effort to do the required formal analyses and pursue SARP supplements to take advantage of these savings. The success of these analyses are dependent upon the availability of the majority of the infrastructure supported by the DOE Nuclear Criticality Safety Program as defined in the Five-Year Plan for the program. Finally, it should be noted that these potential cost

  8. Charge-Transfer Interactions in Organic Functional Materials

    Directory of Open Access Journals (Sweden)

    Bih-Yaw Jin

    2010-08-01

    Full Text Available Our goal in this review is three-fold. First, we provide an overview of a number of quantum-chemical methods that can abstract charge-transfer (CT information on the excited-state species of organic conjugated materials, which can then be exploited for the understanding and design of organic photodiodes and solar cells at the molecular level. We stress that the Composite-Molecule (CM model is useful for evaluating the electronic excited states and excitonic couplings of the organic molecules in the solid state. We start from a simple polyene dimer as an example to illustrate how interchain separation and chain size affect the intercahin interaction and the role of the charge transfer interaction in the excited state of the polyene dimers. With the basic knowledge from analysis of the polyene system, we then study more practical organic materials such as oligophenylenevinylenes (OPVn, oligothiophenes (OTn, and oligophenylenes (OPn. Finally, we apply this method to address the delocalization pathway (through-bond and/or through-space in the lowest excited state for cyclophanes by combining the charge-transfer contributions calculated on the cyclophanes and the corresponding hypothetical molecules with tethers removed. This review represents a step forward in the understanding of the nature of the charge-transfer interactions in the excited state of organic functional materials.

  9. Simulation Study for Cosmic Ray Muons to Detecte Fissile Nuclear Materials%宇宙射线μ子探测裂变核材料的模拟研究

    Institute of Scientific and Technical Information of China (English)

    庞洪超; 刘森林; 王红艳; 杨宏伟

    2011-01-01

    平均能量为3~4 GeV的宇宙射线μ子在海平面的通量约为l/(cm2·min),这些μ子有很强的穿透力,能够穿透目前常用的防护层.μ子与物质作用主要发生小角度库伦散射,散射角与物质的原子序数有关.利用μ子穿过不同物质时所产生的散射角不同来辐射成像,研究v子的累计通量条件下,辨别低、中、高Z三类物质的可行性.%Cosmic ray muons with the mean energy 3-4 GeV shower the Earth at the rate of 1 cm-2·min-1 at sea level. They are highly penetrating, which can penetrate the protective layer of the common use. A muon passing through a material is deflected by many small angle scatters off of the nuclei of the material. The size of the scattering angle is related to the atomic number of the material. Based upon the difference of the scattering angle of muon passing through object, the radiation imaging could be obtained. In this paper, we conclude that it is feasible to use the technique of Muon Tomography to identify the low, medium and high Z three types of material of the muon cumulate flux for a minute.

  10. Automatic graphene transfer system for improved material quality and efficiency

    Science.gov (United States)

    Boscá, Alberto; Pedrós, Jorge; Martínez, Javier; Palacios, Tomás; Calle, Fernando

    2016-02-01

    In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The process is based on the all-fluidic manipulation of the graphene to avoid mechanical damage, strain and contamination, and on the combination of capillary action and electrostatic repulsion between the graphene and its container to ensure a centered sample on top of the target substrate. The improved carrier mobility and yield of the automatically transferred graphene, as compared to that manually transferred, is demonstrated by the optical and electrical characterization of field-effect transistors fabricated on both materials. In particular, 70% higher mobility values, with a 30% decrease in the unintentional doping and a 10% strain reduction are achieved. The system has been developed for lab-scale transfer and proved to be scalable for industrial applications.

  11. Fissile Material Disposition Program: Deep Borehole Disposal Facility PEIS data input report for direct disposal. Direct disposal of plutonium metal/plutonium dioxide in compound metal canisters. Version 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, A.M.; Shaffer, R.J.

    1996-01-15

    The US Department of Energy (DOE) is examining options for disposing of excess weapons-usable nuclear materials [principally plutonium (Pu) and highly enriched uranium (HEU)] in a form or condition that is substantially and inherently more difficult to recover and reuse in weapons production. This report is the data input report for the Programmatic Environmental Impact Statement (PEIS). The PEIS examines the environmental, safety, and health impacts of implementing each disposition alternative on land use, facility operations, and site infrastructure; air quality and noise; water, geology, and soils; biotic, cultural, and paleontological resources; socioeconomics; human health; normal operations and facility accidents; waste management; and transportation. This data report is prepared to assist in estimating the environmental effects associated with the construction and operation of a Deep Borehole Disposal Facility, an alternative currently included in the PEIS. The facility projects under consideration are, not site specific. This report therefore concentrates on environmental, safety, and health impacts at a generic site appropriate for siting a Deep Borehole Disposal Facility.

  12. Fissile Material Disposition Program: Deep Borehole Disposal Facility PEIS data input report for direct disposal. Direct disposal of plutonium metal/plutonium dioxide in compound metal canisters. Version 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, A.M.; Shaffer, R.J.

    1996-01-15

    The US Department of Energy (DOE) is examining options for disposing of excess weapons-usable nuclear materials [principally plutonium (Pu) and highly enriched uranium (HEU)] in a form or condition that is substantially and inherently more difficult to recover and reuse in weapons production. This report is the data input report for the Programmatic Environmental Impact Statement (PEIS). The PEIS examines the environmental, safety, and health impacts of implementing each disposition alternative on land use, facility operations, and site infrastructure; air quality and noise; water, geology, and soils; biotic, cultural, and paleontological resources; socioeconomics; human health; normal operations and facility accidents; waste management; and transportation. This data report is prepared to assist in estimating the environmental effects associated with the construction and operation of a Deep Borehole Disposal Facility, an alternative currently included in the PEIS. The facility projects under consideration are, not site specific. This report therefore concentrates on environmental, safety, and health impacts at a generic site appropriate for siting a Deep Borehole Disposal Facility.

  13. Scaling of heat transfer in granular material in rotating drums

    Science.gov (United States)

    Yohannes, Bereket; Emady, Heather; Pardes, Ingrid; Javed, Maham; Borghard, William; Glasser, Benjamin; Muzzio, Fernando; Cuitino, Alberto

    Several industrial processes involve thermal treatment of granular materials and powders, in devices such as rotating drums, to bring about a desired chemical and/or physical transformation. Developing a better understanding of the heat transfer process can significantly improve the quality of the end product and efficiency. However, there is a lack of predictive models, for example, to predict the evolution of the distribution and average of the particles' temperature, particularly for the purposes of scale-up from laboratory scale experiments to manufacturing scale productions. We used discrete element method (DEM) based simulations to study the distribution of particles' temperature in rotating drums at low temperature. Various physical, mechanical, and thermal properties of particles were considered in the simulations and in the analysis. In addition, the effect of operating conditions such as size of drum, material fill level, and speed of rotation on the heat transfer were investigated. Based on the simulations, we identified timescales relevant to the heat transfer process and developed a relationship between these timescales that can be used to predict the average temperature of particles. We also found that the evolution of the temperature distribution, since different particles may have different temperatures, can be predicted based on these timescales. These findings can be used to predict the required time to heat up all particles to the desired temperature.

  14. Conduit for high temperature transfer of molten semiconductor crystalline material

    Science.gov (United States)

    Fiegl, George (Inventor); Torbet, Walter (Inventor)

    1983-01-01

    A conduit for high temperature transfer of molten semiconductor crystalline material consists of a composite structure incorporating a quartz transfer tube as the innermost member, with an outer thermally insulating layer designed to serve the dual purposes of minimizing heat losses from the quartz tube and maintaining mechanical strength and rigidity of the conduit at the elevated temperatures encountered. The composite structure ensures that the molten semiconductor material only comes in contact with a material (quartz) with which it is compatible, while the outer layer structure reinforces the quartz tube, which becomes somewhat soft at molten semiconductor temperatures. To further aid in preventing cooling of the molten semiconductor, a distributed, electric resistance heater is in contact with the surface of the quartz tube over most of its length. The quartz tube has short end portions which extend through the surface of the semiconductor melt and which are lef bare of the thermal insulation. The heater is designed to provide an increased heat input per unit area in the region adjacent these end portions.

  15. Feasibility of fissile mass assay of spent nuclear fuel using {sup 252}Cf-source-driven frequency-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mattingly, J.K.; Valentine, T.E.; Mihalczo, J.T.

    1996-10-01

    The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a {sup 252}Cf source adjacent to the assembly and correlating source fissions with the response of a bank of {sup 3}He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was calculated for each of these 28 simulated measurements. The magnitude of the cross-spectrum signature follows a smooth upward trend with increasing fissile material ({sup 235}U and {sup 239}Pu) content, and the signature is independent of the concentration of spontaneously fissioning isotopes (e.g., {sup 244}Cm) and ({alpha},n) sources. Furthermore, the cross-spectrum signature is highly sensitive to changes in fissile material content. This feasibility study indicated that the signature would increase {similar_to}100% in response to an increase of only 0.1 g/cm{sup 3} of fissile material.

  16. Fissile materials disposition program plutonium immobilization project baseline formulation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B B; Armantrout, G A; Gray, L; Herman, C C; Shaw, H F; Van Konynenburg, R A

    2000-09-01

    Since 1994 Lawrence Livermore National Laboratory (LLNL), with the help of several other laboratories and university groups, has been the lead laboratory for the Plutonium Immobilization Project (PIP). This involves, among other tasks, the development of a formulation and a fabrication process for a ceramic to be used in the immobilization of excess weapons-usable plutonium. This report reviews the history of the project as it relates to the development of the ceramic form. It describes the sample test plan for the pyrochlore-rich ceramic formulation that was selected, and it specifies the baseline formulation that has been adopted. It also presents compositional specifications (e.g. precursor compositions and mixing recipes) and other form and process specifications that are linked or potentially linked to the baseline formulation.

  17. Minimizing the fissile inventory of the molten salt fast reactor

    OpenAIRE

    Merle-Lucotte, E.; Heuer, D.; Allibert, M.; Doligez, X.; Ghetta, V.

    2009-01-01

    International audience; Molten salt reactors in the configurations presented here, called Molten Salt Fast Reactors (MSFR), have been selected for further studies by the Generation IV International Forum. These reactors may be operated in simplified and safe conditions in the Th/233U fuel cycle with fluoride salts. We present here the concept, before focusing on a possible optimization in term of minimization of the initial fissile inventory. Our studies demonstrate that an inventory of 233U ...

  18. Transferable Deformation-Dipole Model for Ionic Materials

    Science.gov (United States)

    Karaman, Ali; Akdeniz, Zehra; Tosi, Mario P.

    2007-06-01

    A model for the ionic interactions in polyvalent metal halides was originally built for chloroaluminate clusters using an analysis of data on static and dynamic structure of their molecular monomers [for a review see M. P. Tosi, Phys. Chem. Liquids 43, 409 (2005)]. Recently, by continuing the deformation-dipole model calculations, the transferability of the halogen parameters was tested through the calculation of the structure of alkali halides and alkaline-earth halides. In this work we test the usefulness of the deformation-dipole model in the study of ionic materials by examining the transferability of the overlap parameters for the halogen ions across families of halide compounds. Following a comparative discussion of alkali and alkaline-earth halide monomers near equilibrium, results on alkaline-earth halides are given. By using the transferable ionic potential model we also calculate the equilibrium structure of the molecular clusters, as well as the vibrational frequencies of ACl4 compounds (where A = U, Np, Pu, Am and Th).

  19. Energy and charge transfer in nanoscale hybrid materials.

    Science.gov (United States)

    Basché, Thomas; Bottin, Anne; Li, Chen; Müllen, Klaus; Kim, Jeong-Hee; Sohn, Byeong-Hyeok; Prabhakaran, Prem; Lee, Kwang-Sup

    2015-06-01

    Hybrid materials composed of colloidal semiconductor quantum dots and π-conjugated organic molecules and polymers have attracted continuous interest in recent years, because they may find applications in bio-sensing, photodetection, and photovoltaics. Fundamental processes occurring in these nanohybrids are light absorption and emission as well as energy and/or charge transfer between the components. For future applications it is mandatory to understand, control, and optimize the wide parameter space with respect to chemical assembly and the desired photophysical properties. Accordingly, different approaches to tackle this issue are described here. Simple organic dye molecules (Dye)/quantum dot (QD) conjugates are studied with stationary and time-resolved spectroscopy to address the dynamics of energy and ultra-fast charge transfer. Micellar as well as lamellar nanostructures derived from diblock copolymers are employed to fine-tune the energy transfer efficiency of QD donor/dye acceptor couples. Finally, the transport of charges through organic components coupled to the quantum dot surface is discussed with an emphasis on functional devices.

  20. Heat transfer in Rockwool modelling and method of measurement. The effect of natural convection on heat transfer in fibrous materials

    Energy Technology Data Exchange (ETDEWEB)

    Dyrboel, Susanne

    1998-05-01

    Fibrous materials are some of the most widely used materials for thermal insulation. In this project the focus of interest has been on fibrous materials for building application. Interest in improving the thermal properties of insulation materials is increasing as legislation is being tightened to reduce the overall energy consumption. A knowledge of the individual heat transfer mechanisms - whereby heat is transferred within a particular material is an essential tool to improve continuously the thermal properties of the material. Heat is transferred in fibrous materials by four different transfer mechanisms: conduction through air, conduction through fibres, thermal radiation and convection. In a particular temperature range the conduction through air can be regarded as a constant, and conduction through fibres is an insignificant part of the total heat transfer. Radiation, however, constitutes 25-40% of the total heat transfer in light fibrous materials. In Denmark and a number of other countries convection in fibrous materials is considered as non-existent when calculating heat transmission as well as when designing building structures. Two heat transfer mechanisms have been the focus of the current project: radiation heat transfer and convection. The radiation analysis serves to develop a model that can be used in further work to gain a wider knowledge of the way in which the morphology of the fibrous material, i.e. fibre diameter distribution, fibre orientation distribution etc., influences the radiation heat transfer under different conditions. The convection investigation serves to examine whether considering convection as non-existent is a fair assumption to use in present and future building structures. The assumption applied in practically is that convection makes a notable difference only in very thick insulation, at external temperatures below -20 deg. C, and at very low densities. For large thickness dimensions the resulting heat transfer through the

  1. Vibration damping and heat transfer using material phase changes

    Science.gov (United States)

    Kloucek, Petr (Inventor); Reynolds, Daniel R. (Inventor)

    2009-01-01

    A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

  2. The simultaneous neutron and photon interrogation method for fissile and non-fissile element separation in radioactive waste drums

    Energy Technology Data Exchange (ETDEWEB)

    Jallu, F. E-mail: fanny.jallu@cea.fr; Lyoussi, A.; Passard, C.; Payan, E.; Recroix, H.; Nurdin, G.; Buisson, A.; Allano, J

    2000-10-01

    Measuring {alpha}-emitters such as ({sup 234,235,236,238}U, {sup 238,239,240,242,244}Pu, {sup 237}Np, {sup 241,243}Am, ...), in solid radioactive waste allows us to quantify the {alpha}-activity in a drum and then to classify it. The simultaneous photon and neutron interrogation experiment (SIMPHONIE) method dealt with in this paper, combines both active neutron interrogation and induced photofission interrogation techniques simultaneously. Its purpose is to quantify fissile ({sup 235}U, {sup 239,241}Pu, ...) and non-fissile ({sup 236,238}U, {sup 238,240}Pu, ...) elements separately in only one measurement. This paper presents the principle of the method, the experimental setup, and the first experimental results obtained using the DGA/ETCA Linac and MiniLinatron pulsed linear electron accelerators located at Arcueil, France. First studies were carried out with U and Pu bare samples.

  3. Monte Carlo Modeling of Minor Actinide Burning in Fissile Spallation Targets

    Science.gov (United States)

    Malyshkin, Yury; Pshenichnov, Igor; Mishustin, Igor; Greiner, Walter

    2014-06-01

    Minor actinides (MA) present a harmful part of spent nuclear fuel due to their long half-lives and high radio-toxicity. Neutrons produced in spallation targets of Accelerator Driven Systems (ADS) can be used to transmute and burn MA. Non-fissile targets are commonly considered in ADS design. However, additional neutrons from fission reactions can be used in targets made of fissile materials. We developed a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems) for simulating neutron production and transport in different spallation targets. MCADS is suitable for calculating spatial distributions of neutron flux and energy deposition, neutron multiplication factors and other characteristics of produced neutrons and residual nuclei. Several modifications of the Geant4 source code described in this work were made in order to simulate targets containing MA. Results of MCADS simulations are reported for several cylindrical targets made of U+Am, Am or Am2O3 including more complicated design options with a neutron booster and a reflector. Estimations of Am burning rates are given for the considered cases.

  4. Bio-inspired Murray materials for mass transfer and activity

    Science.gov (United States)

    Zheng, Xianfeng; Shen, Guofang; Wang, Chao; Li, Yu; Dunphy, Darren; Hasan, Tawfique; Brinker, C. Jeffrey; Su, Bao-Lian

    2017-04-01

    Both plants and animals possess analogous tissues containing hierarchical networks of pores, with pore size ratios that have evolved to maximize mass transport and rates of reactions. The underlying physical principles of this optimized hierarchical design are embodied in Murray's law. However, we are yet to realize the benefit of mimicking nature's Murray networks in synthetic materials due to the challenges in fabricating vascularized structures. Here we emulate optimum natural systems following Murray's law using a bottom-up approach. Such bio-inspired materials, whose pore sizes decrease across multiple scales and finally terminate in size-invariant units like plant stems, leaf veins and vascular and respiratory systems provide hierarchical branching and precise diameter ratios for connecting multi-scale pores from macro to micro levels. Our Murray material mimics enable highly enhanced mass exchange and transfer in liquid-solid, gas-solid and electrochemical reactions and exhibit enhanced performance in photocatalysis, gas sensing and as Li-ion battery electrodes.

  5. Increasing Boiling Heat Transfer using Low Conductivity Materials.

    Science.gov (United States)

    Rahman, Md Mahamudur; Pollack, Jordan; McCarthy, Matthew

    2015-08-18

    We report the counterintuitive mechanism of increasing boiling heat transfer by incorporating low-conductivity materials at the interface between the surface and fluid. By embedding an array of non-conductive lines into a high-conductivity substrate, in-plane variations in the local surface temperature are created. During boiling the surface temperature varies spatially across the substrate, alternating between high and low values, and promotes the organization of distinct liquid and vapor flows. By systematically tuning the peak-to-peak wavelength of this spatial temperature variation, a resonance-like effect is seen at a value equal to the capillary length of the fluid. Replacing ~18% of the surface with a non-conductive epoxy results in a greater than 5x increase in heat transfer rate at a given superheat temperature. This drastic and counterintuitive increase is shown to be due to optimized bubble dynamics, where ordered pathways allow for efficient removal of vapor and the return of replenishing liquid. The use of engineered thermal gradients represents a potentially disruptive approach to create high-efficiency and high-heat-flux boiling surfaces which are naturally insensitive to fouling and degradation as compared to other approaches.

  6. Study of the Material Transfer Characteristics and Surface Morphology Due to Arc Erosion of PtIr Contact Materials

    Institute of Scientific and Technical Information of China (English)

    WANG Saibei; XIE Ming; YANG Youcai; ZHANG Jiming; CHEN Yongtai; LIU Manmen; YANG Yunfeng; HU Jieqiong; CUI Hao

    2012-01-01

    By means of breaking tests on PtIr contact materials via a JF04C contact material testing machine,it was attempted to elucidate the characterstics of the various surface morphology and material transfer after the arc erosion process caused by break arc.The material transfer characteristics appeared in the experiments were concluded and analyzed.Meanwhile,the morphology of the anode and cathode surface were observed and analyzed by SEM.

  7. PETIs as High-Temperature Resin-Transfer-Molding Materials

    Science.gov (United States)

    Connell, John N.; Smith, Joseph G., Jr.; Hergenrother, Paul M.

    2005-01-01

    Compositions of, and processes for fabricating, high-temperature composite materials from phenylethynyl-terminated imide (PETI) oligomers by resin-transfer molding (RTM) and resin infusion have been developed. Composites having a combination of excellent mechanical properties and long-term high-temperature stability have been readily fabricated. These materials are particularly useful for the fabrication of high-temperature structures for jet-engine components, structural components on highspeed aircraft, spacecraft, and missiles. Phenylethynyl-terminated amide acid oligomers that are precursors of PETI oligomers are easily made through the reaction of a mixture of aromatic diamines with aromatic dianhydrides at high stoichiometric offsets and 4-phenylethynylphthalic anhydride (PEPA) as an end-capper in a polar solvent such as N-methylpyrrolidinone (NMP). These oligomers are subsequently cyclodehydrated -- for example, by heating the solution in the presence of toluene to remove the water by azeotropic distillation to form low-molecular-weight imide oligomers. More precisely, what is obtained is a mixture of PETI oligomeric species, spanning a range of molecular weights, that exhibits a stable melt viscosity of less than approximately 60 poise (and generally less than 10 poise) at a temperature below 300 deg C. After curing of the oligomers at a temperature of 371 deg C, the resulting polymer can have a glass-transition temperature (Tg) as high as 375 C, the exact value depending on the compositions.

  8. A comparative study between transport and criticality safety indexes for fissile uranium nuclearly pure

    Energy Technology Data Exchange (ETDEWEB)

    Moraes da Silva, T. de; Sordi, G.M.A.A. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN (Brazil)]. e-mail: tmsilva@ipen.br

    2006-07-01

    The international and national standards determine that during the transport of radioactive materials the package to be sent should be identified by labels of risks specifying content, activity and the transport index. The result of the monitoring of the package to 1 meter identifies the transport index, TI, which represents the dose rate to 1 meter of this. The transport index is, by definition, a number that represents a gamma radiation that crosses the superficial layer the radioactive material of the package to 1 meter of distance. For the fissile radioactive material that is the one in which a neutron causes the division of the atom, the international standards specify criticality safety index CSI, which is related with the safe mass of the fissile element. In this work it was determined the respective safe mass for each considered enrichment for the compounds of uranium oxides UO{sub 2}, U{sub 3}O{sub 8} and U{sub 3}Si{sub 2}. In the study of CSI it was observed that the value 50 of the expression 50/N being N the number of packages be transported in subcriticality conditions it represents a fifth part of the safe mass of the element uranium or 9% of the smallest mass critical for a transport not under exclusive use. As conclusion of the accomplished study was observed that the transport index starting from 7% of enrichment doesn't present contribution and that criticality safety index is always greater than the transport index. Therefore what the standards demand to specify, the largest value between both indexes, was clearly identified in this study as being the criticality safety index. (Author)

  9. DEVELOPMENT OF THE HS99 AIR TRANSPORT TYPE A FISSILE PACKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, P.; Eberl, K.

    2012-07-10

    An air-transport Type A Fissile radioactive shipping package for the transport of special form uranium sources has been developed by the Savannah River National Laboratory (SRNL) for the Department of Homeland Security. The Package model number is HS99 for Homeland Security Model 99. This paper presents the major design features of the HS99 and highlights engineered materials necessary for meeting the design requirements for this light-weight Type AF packaging. A discussion is provided demonstrating how the HS99 complies with the regulatory safety requirements of the Nuclear Regulatory Commission. The paper summarizes the results of structural testing to specified in 10 CFR 71 for Normal Conditions of Transport and Hypothetical Accident Conditions events. Planned and proposed future missions for this packaging are also addressed.

  10. CFD ANALYSIS FOR HEAT TRANSFER BETWEEN COPPER ENCAPSULATED PHASE CHANGE MATERIAL AND HEAT TRANSFER FLUID

    National Research Council Canada - National Science Library

    M.Premkumar; S.Ramachandran

    2013-01-01

    .... In this study the analysis of heat transfer between PCM and heat transfer fluids (HTF) with Spherical and cylindrical finned encapsulations made of copper are done using computational fluid dynamic (CFD...

  11. Finite element formulation of axisymmetric heat transfer problem for orthotropic materials

    Institute of Scientific and Technical Information of China (English)

    闫相桥; 童剑; 武海鹏

    2003-01-01

    By using Galerkin's method, the finite element formulation is made for axisymmtric heat transfer problems for anisotropic materials from the heat transfer differential equations expressed in terms of heat fluid density. Results of an example show that the heat transfer anisotropy has an important effect on temperature field.

  12. Examining the stability of thermally fissile Th and U isotopes

    Science.gov (United States)

    Kumar, Bharat; Biswal, S. K.; Singh, S. K.; Patra, S. K.

    2015-11-01

    The properties of recently predicted thermally fissile Th and U isotopes are studied within the framework of the relativistic mean-field approach using the axially deformed basis. We calculate the ground, first intrinsic excited state for highly neutron-rich thorium and uranium isotopes. The possible modes of decay such as α decay and β decay are analyzed. We found that neutron-rich isotopes are stable against α decay, however, they are very unstable against β decay. The lifetime of these nuclei is predicted to be tens of seconds against β decay. If these nuclei are utilized before their decay time, a lot of energy can be produced with the help of multifragmentation fission. Also, these nuclei have great implications from the astrophysical point of view. In some cases, we found that the isomeric states with energy range from 2 to 3 MeV and three maxima in the potential energy surface of Th-230228 and U-234228 isotopes.

  13. Synthesis, Transfer, and Characterization of Nanoscale 2-Dimensional Materials

    Science.gov (United States)

    2015-09-01

    image of graphene on copper foil. The inset shows the corresponding white light image. b) Graphene domains transferred to 285-nm SiO2 /Si. c) SEM image...method for system optimization. Graphene adlayers can also be readily imaged in white light by transferring the domains onto 285-nm SiO2 /Si substrate... Graphene domains transferred onto SiO2 /Si are shown in Fig 3b. The unique optical interference between the graphene and oxide layer make the

  14. Extensions to Dynamic System Simulation of Fissile Solution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bernardin, John David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-24

    Previous reports have documented the results of applying dynamic system simulation (DSS) techniques to model a variety of fissile solution systems. The SUPO (Super Power) aqueous homogeneous reactor (AHR) was chosen as the benchmark for comparison of model results to experimental data for steadystate operation.1 Subsequently, DSS was applied to additional AHR to verify results obtained for SUPO and extend modeling to prompt critical excursions, ramp reactivity insertions of various magnitudes and rate, and boiling operations in SILENE and KEWB (Kinetic Experiment Water Boiler).2 Additional models for pressurized cores (HRE: Homogeneous Reactor Experiment), annular core geometries, and accelerator-driven subcritical systems (ADAHR) were developed and results reported.3 The focus of each of these models is core dynamics; neutron kinetics, thermal hydraulics, radiolytic gas generation and transport are coupled to examine the time-based evolution of these systems from start-up through transition to steady-state. A common characteristic of these models is the assumption that (a) core cooling system inlet temperature and flow and (b) plenum gas inlet pressure and flow are held constant; no external (to core) component operations that may result in dynamic change to these parameters are considered. This report discusses extension of models to include explicit reference to cooling structures and radiolytic gas handling. The accelerator-driven subcritical generic system model described in References 3 and 4 is used as a basis for this extension.

  15. Simulator for an Accelerator-Driven Subcritical Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Day, Christy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Determan, John C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-14

    LANL has developed a process to generate a progressive family of system models for a fissile solution system. This family includes a dynamic system simulation comprised of coupled nonlinear differential equations describing the time evolution of the system. Neutron kinetics, radiolytic gas generation and transport, and core thermal hydraulics are included in the DSS. Extensions to explicit operation of cooling loops and radiolytic gas handling are embedded in these systems as is a stability model. The DSS may then be converted to an implementation in Visual Studio to provide a design team the ability to rapidly estimate system performance impacts from a variety of design decisions. This provides a method to assist in optimization of the system design. Once design has been generated in some detail the C++ version of the system model may then be implemented in a LabVIEW user interface to evaluate operator controls and instrumentation and operator recognition and response to off-normal events. Taken as a set of system models the DSS, Visual Studio, and LabVIEW progression provides a comprehensive set of design support tools.

  16. Examining the stability of thermally fissile Th and U isotopes

    CERN Document Server

    Kumar, Bharat; Singh, S K; Patra, S K

    2015-01-01

    The properties of recently predicted thermally fissile Th and U isotopes are studied within the framework of relativistic mean field (RMF) approach using axially deformed basis. We calculated the ground, first intrinsic excited state and matter density for highly neutron-rich thorium and uranium isotopes. The possible modes of decay like $\\alpha$-decay and $\\beta$-decay are analyzed. We found that the neutron-rich isotopes are stable against $\\alpha$-decay, however they are very much unstable against $\\beta$-decay. The life time of these nuclei predicted to be tens of second against $\\beta$-decay. If these nuclei utilize before their decay time, a lots of energy can be produced within the help of multi-fragmentation fission. Also, these nuclei have a great implication in astrophysical point of view. The total nucleonic densities distribution are calculated, from which the clusters inside the parent nuclei are determined. %Most of the thorium isotopes are $\\alpha$ emitters, where as some %of them have short ha...

  17. Simulator for an Accelerator-Driven Subcritical Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Day, Christy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Determan, John C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-14

    LANL has developed a process to generate a progressive family of system models for a fissile solution system. This family includes a dynamic system simulation comprised of coupled nonlinear differential equations describing the time evolution of the system. Neutron kinetics, radiolytic gas generation and transport, and core thermal hydraulics are included in the DSS. Extensions to explicit operation of cooling loops and radiolytic gas handling are embedded in these systems as is a stability model. The DSS may then be converted to an implementation in Visual Studio to provide a design team the ability to rapidly estimate system performance impacts from a variety of design decisions. This provides a method to assist in optimization of the system design. Once design has been generated in some detail the C++ version of the system model may then be implemented in a LabVIEW user interface to evaluate operator controls and instrumentation and operator recognition and response to off-normal events. Taken as a set of system models the DSS, Visual Studio, and LabVIEW progression provides a comprehensive set of design support tools.

  18. Statistics vs. dynamics: hints from systems of intermediate fissility

    Energy Technology Data Exchange (ETDEWEB)

    Vardaci, E; Di Nitto, A; Brondi, A; Rana, G La; Moro, R [Dipartimento di Scienze Fisiche, Universita di Napoli ' Federico II' , 80126 Napoli (Italy); Nadtochy, P; Ordine, A; Boiano, A [Istituto Nazionale di Fisica Nucleare, 80126 Napoli (Italy); Cinausero, M; Prete, G; Rizzi, V [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Padova) (Italy); Gelli, N; Lucarelli, F [Dipartimento di Fisica and Istituto Nazionale di Fisica Nucleare, Firenze (Italy); Knyazheva, G N; Kozulin, E M; Loktev, T A; Smirnov, S, E-mail: Emanuele.Vardaci@na.infn.it [Flerov Laboratory of Nuclear Reactions, JINR, 141980, Dubna (Russian Federation)

    2011-02-01

    Systems of intermediate fissility are characterized by an evaporation residues cross section comparable or larger than the fission cross section, and by a relatively higher probability for charged particle emission in the pre-scission channel. In a theoretical framework in which time scale estimates of the fission process rely on statistical model calculations, the analysis of particle emission in the evaporation residues channel is the source of additional constraints on statistical and dynamical models. This contribution will focus on our statistical and dynamical analysis of a more complete set of data from the system {sup 32}S + {sup 100}Mo at E{sub Lab} = 200 MeV. Statistical model fails in reproducing the whole set of data and no convincing estimate is possible of the fission time scale. In particular, while pre-scission multiplicities can be reproduced without delay, the model strongly overestimates proton and alpha particle multiplicities in the evaporation residues channel irrespective of the statistical model input parameters and prescriptions used for the level density and the transmission coefficients. The analysis of the same set of data with a dynamical model produces a very good agreement with the full set of data and indicates that one-body dissipation plays a dominant role in the fission process, implying a fission delay of 23-25x10{sup -21}s.

  19. DEM simulation of heat transfer in granular materials

    Science.gov (United States)

    Gui, Nan; Xu, Wenkai; Ge, Liang

    2013-07-01

    This study investigates the heat conduction of low conductivity granular particles in a two-dimensional modeling of a rotary drum using discrete element method (DEM) method. The Shannon entropy and Lagrangian mean temperature difference are used for comparative study. The results obtained by these two methods are in accordance with each other. It shows the evolution of heat conduction in rotary drums can be divided into a dynamically dominated stage and a thermodynamically dominated stage. The former is determined mainly by particle mixing and the latter is by particle-particle contact duration. The mechanisms for these two stages are explained and the heat transfer characteristics in these two stages are explored.

  20. Excitation energy transfer in organic materials: from fundamentals to optoelectronic devices.

    Science.gov (United States)

    Laquai, Frédéric; Park, Young-Seo; Kim, Jang-Joo; Basché, Thomas

    2009-07-16

    In this review, we discuss investigations of electronic excitation energy transfer in conjugated organic materials at the bulk and single molecule level and applications of energy transfer in fluorescent and phosphorescent organic light emitting devices. A brief overview of common descriptions of energy transfer mechanisms is given followed by a discussion of some basic photophysics of conjugated materials including the generation of excited states and their subsequent decay through various channels. In particular, various examples of bimolecular excited state annihilation processes are presented. Energy transfer studies at the single molecule level provide a new tool to study electronic couplings in simple donor/acceptor dyads and conjugated polymers. Finally, energy transfer in organic electronic devices is discussed with particular emphasis on triplet emitter doped OLEDs and blends for white light emission.

  1. Control of radioactive wastes and coupling of neutron/gamma measurements: use of radiative capture for the correction of matrix effects that penalize the fissile mass measurement by active neutron interrogation; Controle des dechets radioactifs et couplage de mesures neutron/gamma: exploitation de la capture radiative pour corriger les effets de matrice penalisant la mesure de la masse fissile par interrogation neutronique active

    Energy Technology Data Exchange (ETDEWEB)

    Loche, F

    2006-10-15

    In the framework of radioactive waste drums control, difficulties arise in the nondestructive measurement of fissile mass ({sup 235}U, {sup 239}Pu..) by Active Neutron Interrogation (ANI), when dealing with matrices containing materials (Cl, H...) influencing the neutron flux. The idea is to use the neutron capture reaction (n,{gamma}) to determine the matrix composition to adjust the ANI calibration coefficient value. This study, dealing with 118 litres, homogeneous drums of density less than 0,4 and composed of chlorinated and/or hydrogenated materials, leads to build abacus linking the {gamma} ray peak areas to the ANI calibration coefficient. Validation assays of these abacus show a very good agreement between the corrected and true fissile masses for hydrogenated matrices (max. relative standard deviation: 23 %) and quite good for chlorinated and hydrogenated matrices (58 %). The developed correction method improves the measured values. It may be extended to 0,45 density, heterogeneous drums. (author)

  2. Experimental study of dynamic effects in moisture transfer in building materials

    DEFF Research Database (Denmark)

    Janssen, Hans; Scheffler, Gregor Albrecht; Plagge, Rudolf

    2016-01-01

    of the moisture transfer processes involved. The available evidence primarily stems from imbibition and drainage experiments on soils however, and compared to many other porous media, these tests consider rather permeable materials with relatively dominant liquid transport at comparatively large (de......)saturation rates. The current knowledge may thus not be directly transferable to moisture transfer in porous media on the whole, and dedicated further research is required. This paper responds to that need, by reporting on an experimental investigation of the occurrence of dynamic effects on moisture transfer...... in building materials. Drying and ad-/desorption tests are executed on two building materials, in which moisture contents and moisture potentials are measured simultaneously. These are translated into dynamic retention relations and dynamic storage coefficients, which both distinctly demonstrate that moisture...

  3. The roles of Material Transfer Agreements in genetics databases and Bio-banks

    NARCIS (Netherlands)

    Margoni, T.; Pascuzzi, G.; Izzo, U.; Macilotti, M.

    2013-01-01

    In this paper, we will analyse the role (or better the roles) that a specific document, the Material Transfer Agreement (MTA), has accrued in the exchange of bio-materials between research institutions. We will see how fundamental such documents have become in the most recent years, and that an

  4. Charge transfer and redistribution at interfaces between metals and 2D materials

    NARCIS (Netherlands)

    Bokdam, Menno

    2013-01-01

    Large potential steps are observed at the interfaces between metals and novel 2D materials. They can lower the work function by more than 1 eV, even when the two parts are only weakly interacting. In this thesis the transfer and redistribution of electrons in metal|2D material heterostructures are s

  5. Measurement of fissile mass in large-size containers with a transportable linear accelerator

    Science.gov (United States)

    Romeyer Dherbey, Jacques; Lyoussi, A.; Buisson, A.

    1997-02-01

    The quantification of transuranic material (TRU) in waste packages is a common problem of countries working in the field of nuclear nondestructive inspection. The direct measurement of TRU mass inside large size closed containers is difficult due to several effects, mainly the matrix attenuation and uncertainty on the localization of the radioactive mass. The present document describes the method being developed to assay conditioned waste packages using a transportable linear accelerator which is called Mini- Linatron. The system uses a pulsed electron beam from the Mini-Linatron to produce high energy bremsstrahlung photon bursts from thin metallic converter. The transportable linear accelerator operates at 6, 9 and 11 MeV with a repetition rate between 10 to 300 Hz and a 4.5 microsecond(s) pulse duration. The maximum gamma dose rate is about 23 Gy/mn at 1 m. The photons induce fission in fissile and fertile nuclei. We counted delayed neutrons emitted after each pulse by using Sequential Photon Interrogation and Neutron Counting Signatures technique which has ben developed in this framework. Results of measurements on an experimental active gamma interrogation facility for embedded intermediate and low level wastes are presented. Finally, the advantages and performances of the photofission interrogation technique, the use of a transportable electron linear accelerator as a particle source, and the experimental and electronic details will be discussed.

  6. The use of a transportable linear accelerator for fissile mass measurements

    Science.gov (United States)

    Romeyer Dherbey, J.; Lyoussi, A.; Buisson, A.

    1997-02-01

    The quantification of transuranic material (TRU) in waste packages is a common care of countries working in the field of nuclear nondestructive prospecting. The direct control of TRU mass inside large size closed containers is difficult due to several effects, mainly the matrix attenuation and uncertainty on the localization of the radioactive mass. The present document describes the method being developed to assay conditioned waste packages using a transportable linear accelerator which is called Mini-Linatron. The system uses a pulsed electron beam from the Mini-Linatron to produce high energy bremsstrahlung photon bursts from thin metallic converter. The transportable linear accelerator operates at 6, 9 and 11 MeV with a repetition rate between 10 to 300 Hz and a 4.5 μs pulse duration. The maximum gamma dose rate is about 23 Gy/mn at 1 m. The photons induce fission in fissile and fertile nuclei. We counted delayed neutrons emitted after each pulse. Results of measurements on an experimental active gamma interrogation facility for embedded intermediate and low level wastes are presented.

  7. Material fatigue data and their transferability on components; Schwingfestigkeitskennwerte und ihre Uebertragbarkeit auf das Bauteil

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, J.W.; Thumser, R.; Diemer, A.; Gerth, U.; Kleemann, S. [Bauhaus-Universitaet Weimar (Germany). Materialforschungs- und -pruefanstalt

    2007-07-01

    Material data describe quantitatively relevant material properties. In this paper fatigue relevant data are discussed regarding availability and ability for the application and transferability on components. Local and nominal approach life prediction is considered. The ultimate load of a component can be reliably predicted by the aid of yield strength and tensile strength of the material. The transferability in the endurance regime under fully reversed loading is shortly discussed. For not fully reversed loading a damage parameter, reflecting the mean stress sensitivity according to FKM-guideline, is introduced for local strain approach application. (orig.)

  8. The influence of surface treatment on mass transfer between air and building material

    DEFF Research Database (Denmark)

    Kwiatkowski, Jerzy; Rode, Carsten; Hansen, Kurt Kielsgaard

    2008-01-01

    The processes of mass transfer between air and building structure and in the material influence not only the conditions within the material but also inside the connected air spaces. The material which absorbs and desorbs water vapour can be used to moderate the amplitude of indoor relative humidity...... and therefore to participate in the improvement of the indoor air quality and energy saving. Many parameters influence water vapour exchange between indoor air and building material. The aim of this work is to present the change of mass transfer under different climatic and material conditions. The measurements...... for the experiments: gypsum board and calcium silicate. The wallpaper and paint were used as finishing materials. Impact of the following parameters for changes of RH was studied: coating, temperature and air movement. The measurements showed that acryl paint (diffusion open) can significantly decrease mass uptake...

  9. Characterization of the heat transfer properties of thermal interface materials

    Science.gov (United States)

    Fullem, Travis Z.

    Physicists have studied the thermal conductivity of solids for decades. As a result of these efforts, thermal conduction in crystalline solids is well understood; there are detailed theories describing thermal conduction due to electrons and phonons. Phonon scattering and transmission at solid/solid interfaces, particularly above cryogenic temperatures, is not well understood and more work is needed in this area. The desire to solve engineering problems which require good thermal contact between mating surfaces has provided enhanced motivation for furthering the state of the art on this topic. Effective thermal management is an important design consideration in microelectronic systems. A common technique for removing excess heat from an electronic device is to attach a heatsink to the device; it is desirable to minimize the thermal resistance between the device and the heatsink. This can be accomplished by placing a thermal interface material (TIM) between the two surfaces. Due to the ever-increasing power densities found in electronic components, there is a desire to design better TIMs, which necessitates the ability to characterize TIM bondlines and to better understand the physics of heat conduction through TIM bondlines. A micro Fourier apparatus which employs Pt thin film thermometers of our design has been built and is capable of precisely quantifying the thermal resistance of thermal interface materials. In the present work several types of commercially available TIMs have been studied using this apparatus, including: greases, filled epoxies, and thermally conductive pads. In the case of filled epoxies, bondlines of various thicknesses, ranging from thirty microns to several hundred microns, have been measured. The microstructure of these bondlines has been investigated using optical microscopy and acoustic microscopy. Measured values of thermal conductivity are considered in terms of microstructural features such as percolation networks and filler particle

  10. Electronic properties of the charge transfer material MnPc/F4TCNQ

    Science.gov (United States)

    Rückerl, Florian; Mahns, Benjamin; Dodbiba, Eni; Nikolis, Vasileios; Herzig, Melanie; Büchner, Bernd; Knupfer, Martin; Hahn, Torsten; Kortus, Jens

    2016-09-01

    We present electronic properties of a charge transfer material consisting of Manganese(ii)Phthalocyanine (MnPc) and 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), investigated by means of photoemission spectroscopy and electron energy-loss spectroscopy, as well as supporting density functional theory calculations. We report the successful formation of a bulk material characterized by a strong interaction of the molecular compounds which affects the optical properties significantly. Our investigations reveal a significant charge transfer, whereas the MnPc molecule is oxidized and F4TCNQ is reduced. The valence band data indicate a full charge transfer between the two partners. The electronic excitation spectrum reveals a relatively small energy gap of MnPc/F4TCNQ of about 0.7 eV, which is related to a charge transfer excitation.

  11. Simultaneous Heat and Mass Transfer Model for Convective Drying of Building Material

    Science.gov (United States)

    Upadhyay, Ashwani; Chandramohan, V. P.

    2016-06-01

    A mathematical model of simultaneous heat and moisture transfer is developed for convective drying of building material. A rectangular brick is considered for sample object. Finite-difference method with semi-implicit scheme is used for solving the transient governing heat and mass transfer equation. Convective boundary condition is used, as the product is exposed in hot air. The heat and mass transfer equations are coupled through diffusion coefficient which is assumed as the function of temperature of the product. Set of algebraic equations are generated through space and time discretization. The discretized algebraic equations are solved by Gauss-Siedel method via iteration. Grid and time independent studies are performed for finding the optimum number of nodal points and time steps respectively. A MATLAB computer code is developed to solve the heat and mass transfer equations simultaneously. Transient heat and mass transfer simulations are performed to find the temperature and moisture distribution inside the brick.

  12. Polyoxometalate active charge-transfer material for mediated redox flow battery

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Travis Mark; Hudak, Nicholas; Staiger, Chad; Pratt, Harry

    2017-01-17

    Redox flow batteries including a half-cell electrode chamber coupled to a current collecting electrode are disclosed herein. In a general embodiment, a separator is coupled to the half-cell electrode chamber. The half-cell electrode chamber comprises a first redox-active mediator and a second redox-active mediator. The first redox-active mediator and the second redox-active mediator are circulated through the half-cell electrode chamber into an external container. The container includes an active charge-transfer material. The active charge-transfer material has a redox potential between a redox potential of the first redox-active mediator and a redox potential of the second redox-active mediator. The active charge-transfer material is a polyoxometalate or derivative thereof. The redox flow battery may be particularly useful in energy storage solutions for renewable energy sources and for providing sustained power to an electrical grid.

  13. Development of Novel Electrode Materials for the Electrocatalysis of Oxygen-Transfer and Hydrogen-Transfer Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Brett Kimball [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Throughout this thesis, the fundamental aspects involved in the electrocatalysis of anodic O-transfer reactions and cathodic H-transfer reactions have been studied. The investigation into anodic O-transfer reactions at undoped and Fe(III)[doped MnO2 films] revealed that MnO2 film electrodes prepared by a cycling voltammetry deposition show improved response for DMSO oxidation at the film electrodes vs. the Au substrate. Doping of the MnO2 films with Fe(III) further enhanced electrode activity. Reasons for this increase are believed to involve the adsorption of DMSO by the Fe(III) sites. The investigation into anodic O-transfer reactions at undoped and Fe(III)-doped RuO2 films showed that the Fe(III)-doped RuO2-film electrodes are applicable for anodic detection of sulfur compounds. The Fe(III) sites in the Fe-RuO2 films are speculated to act as adsorption sites for the sulfur species while the Ru(IV) sites function for anodic discharge of H2O to generate the adsorbed OH species. The investigation into cathodic H-transfer reactions, specifically nitrate reduction, at various pure metals and their alloys demonstrated that the incorporation of metals into alloy materials can create a material that exhibits bifunctional properties for the various steps involved in the overall nitrate reduction reaction. The Sb10Sn20Ti70, Cu63Ni37 and Cu25Ni75 alloy electrodes exhibited improved activity for nitrate reduction as compared to their pure component metals. The Cu63Ni37 alloy displayed the highest activity for nitrate reduction. The final investigation was a detailed study of the electrocatalytic activity of cathodic H-transfer reactions (nitrate reduction) at various compositions of Cu-Ni alloy electrodes. Voltammetric response for NO3- at the Cu-Ni alloy electrode is superior to

  14. Temperature Profile of the Solution Vessel of an Accelerator-Driven Subcritical Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Determan, John C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-14

    Dynamic System Simulation (DSS) models of fissile solution systems have been developed and verified against a variety of historical configurations. DSS techniques have been applied specifically to subcritical accelerator-driven systems using fissile solution fuels of uranium. Initial DSS models were developed in DESIRE, a specialized simulation scripting language. In order to tailor the DSS models to specifically meet needs of system designers they were converted to a Visual Studio implementation, and one of these subsequently to National Instrument’s LabVIEW for human factors engineering and operator training. Specific operational characteristics of subcritical accelerator-driven systems have been examined using a DSS model tailored to this particular class using fissile fuel.

  15. Influence of asymmetry and fissility on even-odd effect in fission-fragment yields

    Directory of Open Access Journals (Sweden)

    Rejmund F.

    2010-10-01

    Full Text Available Based on a wide systematics of fragment distributions measured in thermal-neutron induced fission, the even-odd staggering in the fission-fragment element yields is investigated. The asymmetry evolution of the element yield distribution with the fissility of the fissioning nucleus is shown to be for an important part responsible for the decrease of the even-odd staggering with the fissility. The even-odd staggering close to symmetry is shown to be a small contribution to the global even-odd effect, and seems to vary little with the fissility of the nucleus. These experimental observations show that the established interpretation in which the intrinsic excitation energy at scission is accountable for the even-odd staggering amplitude has to be reconsidered.

  16. Temperature Profile of the Solution Vessel of an Accelerator-Driven Subcritical Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Determan, John C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-14

    Dynamic System Simulation (DSS) models of fissile solution systems have been developed and verified against a variety of historical configurations. DSS techniques have been applied specifically to subcritical accelerator-driven systems using fissile solution fuels of uranium. Initial DSS models were developed in DESIRE, a specialized simulation scripting language. In order to tailor the DSS models to specifically meet needs of system designers they were converted to a Visual Studio implementation, and one of these subsequently to National Instrument’s LabVIEW for human factors engineering and operator training. Specific operational characteristics of subcritical accelerator-driven systems have been examined using a DSS model tailored to this particular class using fissile fuel.

  17. Two-scale analysis method for predicting heat transfer performance of composite materials with random grain distribution

    Institute of Scientific and Technical Information of China (English)

    LI Youyun; CUI Junzhi

    2004-01-01

    A two-scale analysis (TSA) method for predicting the heat transfer performance of composite materials with the random distribution of same-scale grains is presented. First the representation of the materials with the random distribution is briefly described. Then the two-scale analysis formulation of heat transfer behavior of the materials with random grain distribution of small periodicity is formally derived by means of construction way for each cell. Finally the numerical result on the heat transfer parameters of composite materials is shown. The numerical result shows that TSA is effective to predict the heat transfer performance of composite materials with random grain distribution.

  18. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    OpenAIRE

    Marzieh Alikhasi; Hakimeh Siadat; Elaheh Beyabanaki; Mohammad Javad Kharazifard

    2015-01-01

    Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials.Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl siloxane (PVS) impressions with square and conical transfer copings using open tray and closed tray ...

  19. Boron as a tracer for material transfer in subduction zones

    Science.gov (United States)

    Rosner, Martin Siegfried

    2003-10-01

    Late Miocene to Quaternary volcanic rocks from the frontal arc to the back-arc region of the Central Volcanic Zone in the Andes show a wide range of delta 11B values (+4 to -7 ‰) and boron concentrations (6 to 60 ppm). Positive delta 11B values of samples from the volcanic front indicate involvement of a 11B-enriched slab component, most likely derived from altered oceanic crust, despite the thick Andean continental lithosphere, and rule out a pure crust-mantle origin for these lavas. The delta 11B values and B concentrations in the lavas decrease systematically with increasing depth of the Wadati-Benioff Zone. This across-arc variation in delta 11B values and decreasing B/Nb ratios from the arc to the back-arc samples are attributed to the combined effects of B-isotope fractionation during progressive dehydration in the slab and a steady decrease in slab-fluid flux towards the back arc, coupled with a relatively constant degree of crustal contamination as indicated by similar Sr, Nd and Pb isotope ratios in all samples. Modelling of fluid-mineral B-isotope fractionation as a function of temperature fits the across-arc variation in delta 11B and we conclude that the B-isotope composition of arc volcanics is dominated by changing delta 11B composition of B-rich slab-fluids during progressive dehydration. Crustal contamination becomes more important towards the back-arc due to the decrease in slab-derived fluid flux. Because of this isotope fractionation effect, high delta 11B signatures in volcanic arcs need not necessarily reflect differences in the initial composition of the subducting slab. Three-component mixing calculations for slab-derived fluid, the mantle wedge and the continental crust based on B, Sr and Nd isotope data indicate that the slab-fluid component dominates the B composition of the fertile mantle and that the primary arc magmas were contaminated by an average addition of 15 to 30 % crustal material. Spät-miozäne bis quartäre Vulkanite der

  20. A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; JIA Li

    2008-01-01

    A new mass transfer model is developped to predict the volatile organic compounds (VOCs) from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds (TVOC) in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the ex-periment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.

  1. Building Thermal Envelope Systems and Materials (BTESM) and research utilization/technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Burn, G. (comp.)

    1990-07-01

    The Monthly Report of the Building Thermal Envelope Systems and Materials (BTESM) Programs is a monthly update of both in-house ORNL projects and subcontract activities in the research areas of building materials, wall systems, foundations, roofs, building diagnostics, and research utilization and technology transfer. Presentations are not stand-alone paragraphs every month. Their principal values are the short-time lapse between accomplishment and reporting and their evolution over a period of several months..

  2. Heat transfer characteristics of coconut oil as phase change material to room cooling application

    Science.gov (United States)

    Irsyad, M.; Harmen

    2017-03-01

    Thermal comfort in a room is one of human needs in the workplace and dwellings, so that the use of air conditioning system in tropical countries is inevitable. This equipment has an impact on the increase of energy consumption. One method of minimizing the energy use is by using the phase change material (PCM) as thermal energy storage. This material utilizes the temperature difference between day and night for the storage and release of thermal energy. PCM development on application as a material for air cooling inlet, partitioning and interior needs to be supported by the study of heat transfer characteristics when PCM absorbs heat from ambient temperature. This study was conducted to determine the heat transfer characteristics on coconut oil as a phase change material. There are three models of experiments performed in this research. Firstly, an experiment was conducted to analyze the time that was needed by material to phase change by varying the temperature. The second experiment analyzed the heat transfer characteristics of air to PCM naturally convection. The third experiment analyzed the forced convection heat transfer on the surface of the PCM container by varying the air velocity. The data of experimental showed that, increasing ambient air temperature resulted in shorter time for phase change. At temperatures of 30°C, the time for phase change of PCM with the thickness of 8 cm was 1700 min, and it was stable at temperatures of 27°C. Increasing air temperature accelerated the phase change in the material. While for the forced convection heat transfer, PCM could reduce the air temperature in the range of 30 to 35°C at about 1 to 2°C, with a velocity of 1-3 m/s.

  3. Hydrogen Transfer in Energetic Materials from ReaxFF and DFT Calculations.

    Science.gov (United States)

    Sergeev, Oleg V; Yanilkin, Alexey V

    2017-04-27

    Energetic materials are characterized by fast and complex chemical reactions. It makes them hardly available for kinetic experiments in relevant conditions and a good target for reactive molecular dynamics simulations. In this work, unimolecular and condensed-phase thermal decomposition of pentaerythritol tetranitrate (PETN) are investigated by ReaxFF molecular dynamics. It is shown that the decomposition kinetics in condensed phase may be described with the activation barrier lower by a factor of 2 than that for isolated molecules. The effect of the intermolecular hydrogen transfer is revealed in condensed phase. Energetic barriers for hydrogen transfer in two energetic materials (methyl nitrate, which is a nitroester as well as PETN, and o-nitrotoluene) are studied with ReaxFF and DFT using nudged elastic band technique. The results indicate that ReaxFF gives significantly lower activation energy for intermolecular hydrogen transfer in nitroesters than different DFT approximations, which explains the molecular dynamics results for PETN.

  4. Mass Transfer Study of Chlorine Dioxide Gas Through Polymeric Packaging Materials

    Science.gov (United States)

    A continuous system for measuring the mass transfer of gaseous chlorine dioxide (ClO2), a strong oxidizing agent and used in food and pharmaceutical packaging, through 10 different types of polymeric packaging material was developed utilizing electrochemical sensor as a detector. Permeability, diff...

  5. Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

    Energy Technology Data Exchange (ETDEWEB)

    McGrail, B. Peter; Brown, Daryl R.; Thallapally, Praveen K.

    2016-08-02

    Methods for releasing associated guest materials from a metal organic framework are provided. Methods for associating guest materials with a metal organic framework are also provided. Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Thermal energy transfer assemblies are provided. Methods for transferring thermal energy are also provided.

  6. Tank 40 final sludge batch 9 chemical and fissile radionuclide characterization results

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kubilius, W. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-06-26

    A sample of Sludge Batch (SB) 9 was pulled from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS)i. The SB9 WAPS sample was also analyzed for chemical composition, including noble metals, and fissile constituents, and these results are reported here. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is fed to the Defense Waste Processing Facility (DWPF) as SB9. At the Savannah River National Laboratory (SRNL), the 3-L Tank 40 SB9 sample was transferred from the shipping container into a 4-L high density polyethylene bottle and solids were allowed to settle. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 547 g sub-sample was removed. This sub-sample was then utilized for all subsequent slurry sample preparations. Eight separate aliquots of the slurry were digested, four with HNO3/HCl (aqua regiaii) in sealed Teflon® vessels and four with NaOH/Na2O2 (alkali or peroxide fusioniii) using Zr crucibles. Three Analytical Reference Glass – 1iv (ARG-1) standards were digested along with a blank for each preparation. Each aqua regia digestion and blank was diluted to 1:100 with deionized water and submitted to Analytical Development (AD) for inductively coupled plasma – atomic emission spectroscopy (ICP-AES) analysis, inductively coupled plasma – mass spectrometry (ICP-MS) analysis, atomic absorption spectroscopy (AA) for As and Se, and cold vapor atomic absorption spectroscopy (CV-AA) for Hg. Equivalent dilutions of the alkali fusion digestions and blank were submitted to AD for ICP-AES analysis. Tank 40 SB9 supernate was collected from a mixed slurry sample in the SRNL Shielded Cells and submitted to AD for ICP-AES, ion chromatography (IC), total base/free OH-/other base, total inorganic

  7. Review on thermal energy storage with phase change: materials, heat transfer analysis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Zalba, Belen; Marin, Jose M. [Dpto. Ingenieria Mecanica, Campus Politecnico, Universidad de Zaragoza, EUITIZ ' EDIFICIO B.3' Maria de Luna 3 (Actur), 50015, Zaragoza (Spain); Cabeza, Luisa F. [Dpt.d' Informatica i Enginyeria Industrial, Escola, Universitaria Politecnica, Universitat de Lleida, CREA, Jaurne 11,69,25001, Lleida (Spain); Mehling, Harald [ZAE Bayem, Division 1: Energy Conversion and Storage, Walther-Meissner-Str. 6, 85748, Garching (Germany)

    2003-02-01

    Thermal energy storage in general, and phase change materials (PCMs) in particular, have been a main topic in research for the last 20 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. In this work, a review has been carried out of the history of thermal energy storage with solid-liquid phase change. Three aspects have been the focus of this review: materials, heat transfer and applications. The paper contains listed over 150 materials used in research as PCMs, and about 45 commercially available PCMs. The paper lists over 230 references. (Author)

  8. Optimization on microlattice materials for sound absorption by an integrated transfer matrix method.

    Science.gov (United States)

    Cai, Xiaobing; Yang, Jun; Hu, Gengkai

    2015-04-01

    Materials with well-defined microlattice structures are superlight, stable, and thus bear great potential in sound absorption. An integrated transfer matrix method (TMM) is proposed to evaluate the sound absorbing efficiency of these lattice materials, in which a massive number of micropores are densely placed. A comparison between integrated TMM and conventional TMM reveals that the proposed approach offers better predictions on sound absorption of microlattice. This approach is then employed to optimize the microlattice material to determine the best pore and porosity that lead to maximum absorbing efficiency capability and minimum required thickness to attain a target sound absorption.

  9. The Effect of Anisotropy of Building Materials on the Moisture Transfer

    Directory of Open Access Journals (Sweden)

    J. Drchalová

    2000-01-01

    Full Text Available The effect of anisotropy of building materials on the moisture transfer in the design of envelope parts of building structures is studied. Two typical fibre containing plate building materials produced in the Czech Republic, Dekalux and Dekalit P, are chosen for the demonstration of this effect. Experimental results show that while for lighter Dekalit P, an order of magnitude difference in the moisture diffusivities k for the two basic orientations, i.e. along and across the plate, is observed, for the heavier Dekalux the differences in k are within the errorbar of the experimental method. As follows from the experimental results, compacting of surface layers of the plates of light fibred materials is very favorable from the point of view of moisture penetration but one should keep in mind that any local damage of the surface layer can result in a considerably faster moisture transfer in the direction along the plate.

  10. Heat transfer at the sintered layer-polysynthetic material interface inside heat micro pipes

    Science.gov (United States)

    Sprinceana, Siviu; Mihai, Ioan

    2016-12-01

    If micro heat pipe heat transfers, the inside working fluid goes through a biphasic state. The flow of the liquid and the vapor thereof by the capillary beds of frittered copper and the layer of capillary polysynthetic material and migration of vapors liquid from the end, takes the heat flow towards the end where a transfer of heat may occur only if there is a difference in temperature between the end of a flat micro heat pipe that gives the acquirer heat and heat flux. The porosity of the material is total pore of the total material volume. In the analysis of heat and mass transfer through porous media, both convective and conductive transfer forms can not be separated, because of the surfaces in contact between the two capillar layers. It had been studied the dependence of the rate of flow of liquid through the frittered porous media, and Reynolds polysynthetic. It tracks changes in the Reynolds number based on the interior capillary porosity. They traced in Mathcad [1] the graphs for changing the Reynolds number of capillary pressure by capillary porosity.

  11. The simulation calculation of acoustics energy transfer through the material structure

    Directory of Open Access Journals (Sweden)

    Zvolenský Peter

    2016-01-01

    Full Text Available The paper deals with the modification of the rail passenger coach floor design aimed at improvement of sound reduction index. Refurbishing was performed by using a new acoustic material with a filamentary microstructure. The materials proposed in research were compared by simulation calculation of acoustic energy transfer trough porous microstructure of filamentary material, and the effect of material porosity on sound reduction index and sound absorption coefficient were observed. This proposed filamentary material can be used in the railway bed structure, too. High degree of noise absorbing, resistance to climate conditions, low specific mass, enable to choose a system of low anti-noise barriers having similar properties as standard high anti-noise walls..

  12. Uncover the Aesthetic Simplicity Associated with Mass Transfer in Energy Materials

    Institute of Scientific and Technical Information of China (English)

    Jiang-Wei Li; Jia Li; Ke-Chun Wen

    2016-01-01

    Aesthetics, referred frequently to as a philosophical term, has played a starring role in forming and evolving a number of aspects of human society, including arts, politics, economics, ethics, etc. Indeed, exploring and investigating the aesthetic phenomena in the scientific field have aroused insightful research findings, which in turn has stimulated research interests in such a science-aesthetics field. In particular, better-evaluated aesthetic aspects of the materials field are expected to be uncovered upon the exceedingly-exposed fundamental breakthroughs in researching the basic structure and functionality of materials. In this report, we glimpse into the aesthetic simplicity of energy materials and comprehend specifically the mass transfer functionalities of key categories of energy materials through an intuitive and bottom-up approach. Our effort aspires to shed new lights on the functionality understanding and manipulation of functional materials in general.

  13. Global nuclear material control model

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, J.S.; Rutherford, D.A.

    1996-05-01

    The nuclear danger can be reduced by a system for global management, protection, control, and accounting as part of a disposition program for special nuclear materials. The development of an international fissile material management and control regime requires conceptual research supported by an analytical and modeling tool that treats the nuclear fuel cycle as a complete system. Such a tool must represent the fundamental data, information, and capabilities of the fuel cycle including an assessment of the global distribution of military and civilian fissile material inventories, a representation of the proliferation pertinent physical processes, and a framework supportive of national or international perspective. They have developed a prototype global nuclear material management and control systems analysis capability, the Global Nuclear Material Control (GNMC) model. The GNMC model establishes the framework for evaluating the global production, disposition, and safeguards and security requirements for fissile nuclear material.

  14. Heat Transfer Characteristics of Liquid-Gas Taylor Flows incorporating Microencapsulated Phase Change Materials

    Science.gov (United States)

    Howard, J. A.; Walsh, P. A.

    2014-07-01

    This paper presents an investigation on the heat transfer characteristics associated with liquid-gas Taylor flows in mini channels incorporating microencapsulated phase change materials (MPCM). Taylor flows have been shown to result in heat transfer enhancements due to the fluid recirculation experienced within liquid slugs which is attributable to the alternating liquid slug and gas bubble flow structure. Microencapsulated phase change materials (MPCM) also offer significant potential with increased thermal capacity due to the latent heat required to cause phase change. The primary aim of this work was to examine the overall heat transfer potential associated with combining these two novel liquid cooling technologies. By investigating the local heat transfer characteristics, the augmentation/degradation over single phase liquid cooling was quantified while examining the effects of dimensionless variables, including Reynolds number, liquid slug length and gas void fraction. An experimental test facility was developed which had a heated test section and allowed MPCM-air Taylor flows to be subjected to a constant heat flux boundary condition. Infrared thermography was used to record high resolution experimental wall temperature measurements and determine local heat transfer coefficients from the thermal entrance point. 30.2% mass particle concentration of the MPCM suspension fluid was examined as it provided the maximum latent heat for absorption. Results demonstrate a significant reduction in experimental wall temperatures associated with MPCM-air Taylor flows when compared with the Graetz solution for conventional single phase coolants. Total enhancement in the thermally developed region is observed to be a combination of the individual contributions due to recirculation within the liquid slugs and also absorption of latent heat. Overall, the study highlights the potential heat transfer enhancements that are attainable within heat exchange devices employing MPCM

  15. A Polarizable and Transferable PHAST CO 2 Potential for Materials Simulation

    KAUST Repository

    Mullen, Ashley L.

    2013-12-10

    Reliable PHAST (Potentials with High Accuracy Speed and Transferability) intermolecular potential energy functions for CO2 have been developed from first principles for use in heterogeneous systems, including one with explicit polarization. The intermolecular potentials have been expressed in a transferable form and parametrized from nearly exact electronic structure calculations. Models with and without explicit many-body polarization effects, known to be important in simulation of interfacial processes, are constructed. The models have been validated on pressure-density isotherms of bulk CO 2 and adsorption in three metal-organic framework (MOF) materials. The present models appear to offer advantages over high quality fluid/liquid state potentials in describing CO2 interactions in interfacial environments where sorbates adopt orientations not commonly explored in bulk fluids. Thus, the nonpolar CO2-PHAST and polarizable CO 2-PHAST* potentials are recommended for materials/interfacial simulations. © 2013 American Chemical Society.

  16. Application of coupled mode theory on radiative heat transfer between layered Lorentz materials

    Science.gov (United States)

    Lin, Chungwei; Wang, Bingnan; Teo, Koon Hoo

    2017-05-01

    The coupled mode theory (CMT) provides a simple and clear framework to analyze the radiation energy exchange between reservoirs. We apply CMT to analyze the radiative heat transfer between layered Lorentz materials whose dielectric functions can be approximated by the Lorentz oscillator model. By comparing the transmissivity computed by the exact solution to that computed by CMT, we find that CMT generally gives a good approximation for this class of materials. The biggest advantage of CMT analysis, in our opinion, is that only the (complex) resonant energies are needed to obtain the radiation energy transfer; the knowledge of the spatial profile of resonances is not required. Several issues, including how to choose the resonant modes, what these modes represent, and the limitation of this method, are discussed. Finally, we also apply the CMT method to the electronic systems, demonstrating the generality of this formalism.

  17. Heat Transfer Modeling of a Charring Material Using Isoconversional Kinetics (Pre-Print)

    Science.gov (United States)

    2016-09-28

    Composite for Open Testing (TACOT) [9], and it corresponds to a lightweight ablative composite . Properties required for typical ablation heat transfer...considered a test case that has been defined to support discussion in the open literature. In this test case, a 3-cm slab of the charring TACOT material...Biochemical Engineering Quarterly, vol. 23, no. 4, pp. 493–496, 2009. 9. Theoretical Ablative Composite for Open Testing (TACOT), Version 2.2, 5th

  18. Numerical study of heat transfer from a wall incorporating a phase change material

    Directory of Open Access Journals (Sweden)

    Bouttout A.

    2013-03-01

    Full Text Available A numerical study of the thermal behavior of walls made up of construction materials used in Algeria and walls containing a phase change materials is presented. The model, based on the enthalpy formulation, is described by an equation of heat transfer. This equation is solved by an implicit method of finite differences and algorithm of Thomas. We analyzed the influence of the wall’s thickness and its composition on the evolution during the time of the temperature of the inside face of thewall.

  19. Optical and thermal characterization of membrane reflector materials for solar orbit transfer vehicles

    Science.gov (United States)

    Farmer, Gregory D.; McGee, Jennie K.; Partch, Russell; Lester, Dean M.

    2002-01-01

    The Air Force Research Laboratory (AFRL), is advancing technologies to enable greater mobility for future AF spacecraft. The Solar Orbit Transfer Vehicle (SOTV) program is developing components for a concept based on a solar thermal rocket and solar thermal power generation. The program is performing ground testing of a thin film membrane concentrator concept. To better understand system performance, a series of optical characterization tests of the membrane material were performed. The objective was to quantify the relationship between membrane optical properties and the concentrator on-orbit transmission performance and thermal profile. During testing we collected reflectivity, absorptivity, transmissivity, and emissivity data for un-coated and coated membrane material. The membrane material tested was fabricated using a flight-qualified polyimide material and proven manufacturing processes. The test results, and system thermal analysis are presented in this paper. The results of this research will be used to refine hardware performance predictions and improve sizing for flight demonstration. .

  20. Modeling the Material Flow and Heat Transfer in Reverse Dual-Rotation Friction Stir Welding

    Science.gov (United States)

    Shi, L.; Wu, C. S.; Liu, H. J.

    2014-08-01

    Reverse dual-rotation friction stir welding (RDR-FSW) is a novel modification of conventional friction stir welding (FSW) process. During the RDR-FSW process, the tool pin and the assisted shoulder are separated and rotate with opposite direction independently, so that there are two material flows with reverse direction. The material flow and heat transfer in RDR-FSW have significant effects on the microstructure and properties of the weld joint. A 3D model is developed to quantitatively analyze the effects of the separated tool pin and the assisted shoulder which rotate in reverse direction on the material flow and heat transfer during RDR-FSW process. Numerical simulation is conducted to predict the temperature profile, material flow field, streamlines, strain rate, and viscosity distributions near the tool. The calculated results show that as the rotation speed of the tool pin increases, the temperature near the tool gets higher, the zone with higher temperature expands, and approximately symmetric temperature distribution is obtained near the tool. Along the workpiece thickness direction, the calculated material flow velocity and its layer thickness near the tool get lowered because the effect of the shoulder is weakened as the distance away from the top surface increases. The model is validated by comparing the predicted values of peak temperature at some typical locations with the experimentally measured ones.

  1. Charge transfer and surface defect healing within ZnO nanoparticle decorated graphene hybrid materials

    Science.gov (United States)

    Pham, Chuyen V.; Repp, Sergej; Thomann, Ralf; Krueger, Michael; Weber, Stefan; Erdem, Emre

    2016-05-01

    To harness the unique properties of graphene and ZnO nanoparticles (NPs) for novel applications, the development of graphene-ZnO nanoparticle hybrid materials has attracted great attention and is the subject of ongoing research. For this contribution, graphene-oxide-ZnO (GO-ZnO) and thiol-functionalized reduced graphene oxide-ZnO (TrGO-ZnO) nanohybrid materials were prepared by novel self-assembly processes. Based on electron paramagnetic resonance (EPR) and photoluminescence (PL) investigations on bare ZnO NPs, GO-ZnO and TrGO-ZnO hybrid materials, we found that several physical phenomena were occurring when ZnO NPs were hybridized with GO and TrGO. The electrons trapped in Zn vacancy defects (VZn-) within the core of ZnO NPs vanished by transfer to GO and TrGO in the hybrid materials, thus leading to the disappearance of the core signals in the EPR spectra of ZnO NPs. The thiol groups of TrGO and sulfur can effectively ``heal'' the oxygen vacancy (VO+) related surface defects of ZnO NPs while oxygen-containing functionalities have low healing ability at a synthesis temperature of 100 °C. Photoexcited electron transfer from the conduction band of ZnO NPs to graphene leads to photoluminescence (PL) quenching of near band gap emission (NBE) of both GO-ZnO and TrGO-ZnO. Simultaneously, electron transfer from graphene to defect states of ZnO NPs is the origin of enhanced green defect emission from GO-ZnO. This observation is consistent with the energy level diagram model of hybrid materials.To harness the unique properties of graphene and ZnO nanoparticles (NPs) for novel applications, the development of graphene-ZnO nanoparticle hybrid materials has attracted great attention and is the subject of ongoing research. For this contribution, graphene-oxide-ZnO (GO-ZnO) and thiol-functionalized reduced graphene oxide-ZnO (TrGO-ZnO) nanohybrid materials were prepared by novel self-assembly processes. Based on electron paramagnetic resonance (EPR) and photoluminescence (PL

  2. Fissile Nuclei Rotation Effect in 235U(n,γf) Process

    Science.gov (United States)

    Danilyan, Gevorg; Granz, Peter; Klenke, Jens; Krakhotin, Vyacheslav; Kuznetsov, Valery; Mezei, Ferenz; Novitsky, Vadim; Pavlov, Valery; Russina, Margarita; Shatalov, Pavel; Wilpert, Thomas

    2009-01-01

    A small shift of an angular distribution of prompt γ-rays relative to the fission axis of 236U* 235U(n,γf) process is presented. This effect has been observed in the experiment at BER-II reactor of BENSC/HMI (Berlin). The sign of the shift depends on the direction of the incident neutron beam polarization. This phenomena can be explained by the rotation of fissile nucleus 236U*, like the effect that has been observed recently at ILL in ternary fission of 235U by cold polarized neutrons. The main surprise of this result is the detection of scission gamma-rays radiated by a fissile nucleus during the time interval of the order of 10-21 s before or after the moment of the neck rupture. Detailed measurements of trigger γ-rays energy dependence are in progress at the neutron beam "MEPHISTO" of FRM-II reactor (Garching).

  3. Transfer matrix method applied to the parallel assembly of sound absorbing materials.

    Science.gov (United States)

    Verdière, Kévin; Panneton, Raymond; Elkoun, Saïd; Dupont, Thomas; Leclaire, Philippe

    2013-12-01

    The transfer matrix method (TMM) is used conventionally to predict the acoustic properties of laterally infinite homogeneous layers assembled in series to form a multilayer. In this work, a parallel assembly process of transfer matrices is used to model heterogeneous materials such as patchworks, acoustic mosaics, or a collection of acoustic elements in parallel. In this method, it is assumed that each parallel element can be modeled by a 2 × 2 transfer matrix, and no diffusion exists between elements. The resulting transfer matrix of the parallel assembly is also a 2 × 2 matrix that can be assembled in series with the classical TMM. The method is validated by comparison with finite element (FE) simulations and acoustical tube measurements on different parallel/series configurations at normal and oblique incidence. The comparisons are in terms of sound absorption coefficient and transmission loss on experimental and simulated data and published data, notably published data on a parallel array of resonators. From these comparisons, the limitations of the method are discussed. Finally, applications to three-dimensional geometries are studied, where the geometries are discretized as in a FE concept. Compared to FE simulations, the extended TMM yields similar results with a trivial computation time.

  4. Parametric Integral Equations Systems Method In Solving Unsteady Heat Transfer Problems For Laser Heated Materials

    Directory of Open Access Journals (Sweden)

    Sawicki Dominik

    2015-09-01

    Full Text Available One of the most popular applications of high power lasers is heating of the surface layer of a material, in order to change its properties. Numerical methods allow an easy and fast way to simulate the heating process inside of the material. The most popular numerical methods FEM and BEM, used to simulate this kind of processes have one fundamental defect, which is the necessity of discretization of the boundary or the domain. An alternative to avoid the mentioned problem are parametric integral equations systems (PIES, which do not require classical discretization of the boundary and the domain while being numerically solved. PIES method was previously used with success to solve steady-state problems, as well as transient heat transfer problems. The purpose of this paper is to test the efficacy of the PIES method with time discretization in solving problem of laser heating of a material, with different pulse shape approximation functions.

  5. Energy transfer and thermal conductivity through inert matrix and nuclear fuel analogous materials

    Energy Technology Data Exchange (ETDEWEB)

    Degueldre, C.; Heimgartner, P.; Graber, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Takano, Masahide; Ohmichi, Toshihiko; Fukuda, Kousaku

    1997-11-01

    Thermal conductivity of zirconia based inert matrix and analogous fuel materials were measured and modelled. Measurements were performed using the laser flash method and systematically applied for binary and ternary zirconia-yttria-erbia as well as quaternary systems including thoria or ceria. Measurements were carried out from room temperature to 1250 K. Thermal conductivity was also modelled taking into account the dopant effect on the lattice parameter of the cubic solid solution, the oxygen vacancy size and their concentration. Experimental and modelled lattice parameter values are compared prior to full justification of the results. In the temperature range from 300 to 950 K, the thermal conductivity of the single phase solid solution with yttria, erbia and ceria as analogous fuel material is about 2 W{center_dot}m{sup -1}K{sup -1}. Energy transfer in these materials is discussed on the basis of both photonic and phononic conductivities. (author)

  6. Advanced stamp geometries and adhesiveless transfer printing modalities for use in deterministic materials assembly

    Science.gov (United States)

    Carlson, Andrew

    Transfer printing has become a robust technique for assembling disparate classes of micro- and nanomaterials into spatially organized, functional arrangements in two and three-dimensional layouts. Such capabilities have made this assembly process invaluable in realizing novel or unusual forms of many high-performance systems, such as flexible electronics, three-dimensional optoelectronics, and bio-compatible or bio-integrated electronic devices. The focus of this thesis is to develop a collection of advanced transfer printing modalities that enable expansion in breadth and diversity of materials and formats that serve as either ink or substrate layers during assembly. Targeted modulation of adhesion at the stamp/nanomaterial interface provides a direct route for enhancing printing efficacy, particularly in 'dry' or adhesiveless systems where intimate contact between the substrate and transferred material is desired. This body of work progresses from several simple, passive techniques that demonstrate either strong or weak levels of stamp adhesion for retrieval and printing, respectively, to more active methods that utilize first dynamic adhesion switching and then ultimately fine control over stamp adhesive strength through the use of targeted mechanical loading. Several examples of assembled devices are discussed to demonstrate the broad utility of these protocols, as well as integration strategies for high throughput, massively parallel printing paradigms.

  7. Measuring Visual Literacy Skills on Students’ Concept Understanding of Genetic Transfer Material

    Science.gov (United States)

    Fibriana, F.; Pamelasari, S. D.; Aulia, L. S.

    2017-04-01

    Visualization is an important skill for all students majoring in natural sciences. Also, the visual literacy skills (VLS) are essential for Microbiology learning. The lecturer can use the external representations (ERs) to visualize the microorganisms and its microenvironment. One of learning materials which are rather difficult to interpret in microbiology is genetic transfer. In this study, we measure the VLS on students’ concept understanding of genetic transfer material using a simple test. The tests were held before and after the lecture on this topic employing a combination of talking drawing with picture and picture model. The results show that in the beginning, students showed their poor visual literacy. After the lecture, students were able to draw their understanding on the genetic transfer in bacteria. Most students’ visual literacy ability improves in the level of acceptable. In conclusion, the students’ ability was improved in the average amount of conceptual knowledge. This result reveals that some students comprehend in the correct level of ability, meaning that they have a high degree of conceptual (propositional) and visual knowledge.

  8. Measuring of fissile isotopes partial antineutrino spectra in direct experiment at nuclear reactor

    CERN Document Server

    Sinev, V V

    2009-01-01

    The direct measuring method is considered to get nuclear reactor antineutrino spectrum. We suppose to isolate partial spectra of the fissile isotopes by using the method of antineutrino spectrum extraction from the inverse beta decay positron spectrum applied at Rovno experiment. This admits to increase the accuracy of partial antineutrino spectra forming the total nuclear reactor spectrum. It is important for the analysis of the reactor core fuel composition and could be applied for non-proliferation purposes.

  9. Fundamental mass transfer modeling of emission of volatile organic compounds from building materials

    Science.gov (United States)

    Bodalal, Awad Saad

    In this study, a mass transfer theory based model is presented for characterizing the VOC emissions from building materials. A 3-D diffusion model is developed to describe the emissions of volatile organic compounds (VOCs) from individual sources. Then the formulation is extended to include the emissions from composite sources (system comprising an assemblage of individual sources). The key parameters for the model (The diffusion coefficient of the VOC in the source material D, and the equilibrium partition coefficient k e) were determined independently (model parameters are determined without the use of chamber emission data). This procedure eliminated to a large extent the need for emission testing using environmental chambers, which is costly, time consuming, and may be subject to confounding sink effects. An experimental method is developed and implemented to measure directly the internal diffusion (D) and partition coefficients ( ke). The use of the method is illustrated for three types of VOC's: (i) Aliphatic Hydrocarbons, (ii) Aromatic Hydrocarbons and ( iii) Aldehydes, through typical dry building materials (carpet, plywood, particleboard, vinyl floor tile, gypsum board, sub-floor tile and OSB). Then correlations for predicting D and ke based solely on commonly available properties such as molecular weight and vapour pressure were proposed for each product and type of VOC. These correlations can be used to estimate the D and ke when direct measurement data are not available, and thus facilitate the prediction of VOC emissions from the building materials using mass transfer theory. The VOC emissions from a sub-floor material (made of the recycled automobile tires), and a particleboard are measured and predicted. Finally, a mathematical model to predict the diffusion coefficient through complex sources (floor adhesive) as a function of time was developed. Then this model (for diffusion coefficient in complex sources) was used to predict the emission rate from

  10. Structures in material transference and vitelline envelope formation in Betta splendens follicles.

    Science.gov (United States)

    Genta, H D

    1996-01-01

    Structures were found by transmission electron microscopy, they were located within follicular cells and the oocyte, and in the interspace between them in follicles of the teleost fish Betta splendens. Some structures with features characteristic or lamellar bodies were found in small follicles. The possible role of these structures in the formation of the vitelline envelope as well as in the material transference is discussed. Vacuoles, vesticles and particles intensely stained were found in the microvilli and the cortical cytoplasm of the oocyte at the onset of vitellogenesis. These results suggest that different substances present in the cellular components of the follicle might be transferred from cell to cell through the extracellular space and through the prolongations that cross the extracellular space.

  11. Transfer model of water-soluble material in saturated/unsaturated ground

    Science.gov (United States)

    Nomura, Shun; Kawai, Katsuyuki; Kakui, Shunsuke; Tachibana, Shinya; Kanazawa, Shinichi; Iizuka, Atsushi

    The ground pollution is one of the most serious environmental issues all over the world now. Industrial wastes discharged from various human activities infiltrate to the ground, diffuse and damage to plants and animals indirectly. Therefore, it is strongly requested to know the transfer behavior of contaminant movement in the ground. In this study, continuous equations and advection-dispersion equation are derived from mass conservation laws in soil, water, air and dissolved material phases. These governing equations are applied to the constitutive model for unsaturated soil and formulated in the framework of the initial boundary value problems with the finite element method The soil/water/air coupled analysis program, DACSAR-M_ad, applied mass transfer equation to is coded. Here, the mass within the ground due to loading is simulated with this code.

  12. Enhancing heat capacity of colloidal suspension using nanoscale encapsulated phase-change materials for heat transfer.

    Science.gov (United States)

    Hong, Yan; Ding, Shujiang; Wu, Wei; Hu, Jianjun; Voevodin, Andrey A; Gschwender, Lois; Snyder, Ed; Chow, Louis; Su, Ming

    2010-06-01

    This paper describes a new method to enhance the heat-transfer property of a single-phase liquid by adding encapsulated phase-change nanoparticles (nano-PCMs), which absorb thermal energy during solid-liquid phase changes. Silica-encapsulated indium nanoparticles and polymer-encapsulated paraffin (wax) nanoparticles have been made using colloid method, and suspended into poly-alpha-olefin (PAO) and water for potential high- and low-temperature applications, respectively. The shells prevent leakage and agglomeration of molten phase-change materials, and enhance the dielectric properties of indium nanoparticles. The heat-transfer coefficients of PAO containing indium nanoparticles (30% by mass) and water containing paraffin nanoparticles (10% by mass) are 1.6 and 1.75 times higher than those of corresponding single-phase fluids. The structural integrity of encapsulation allows repeated use of such nanoparticles for many cycles in high heat generating devices.

  13. Transfer printing techniques for materials assembly and micro/nanodevice fabrication.

    Science.gov (United States)

    Carlson, Andrew; Bowen, Audrey M; Huang, Yonggang; Nuzzo, Ralph G; Rogers, John A

    2012-10-09

    Transfer printing represents a set of techniques for deterministic assembly of micro-and nanomaterials into spatially organized, functional arrangements with two and three-dimensional layouts. Such processes provide versatile routes not only to test structures and vehicles for scientific studies but also to high-performance, heterogeneously integrated functional systems, including those in flexible electronics, three-dimensional and/or curvilinear optoelectronics, and bio-integrated sensing and therapeutic devices. This article summarizes recent advances in a variety of transfer printing techniques, ranging from the mechanics and materials aspects that govern their operation to engineering features of their use in systems with varying levels of complexity. A concluding section presents perspectives on opportunities for basic and applied research, and on emerging use of these methods in high throughput, industrial-scale manufacturing. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Analysis of microencapsulated phase change material slurries and phase change material emulsions as heat transfer fluid and thermal storage material

    OpenAIRE

    Delgado Gracia, Mónica; Zalba Nonay, Belen; Lázaro Fernández, Ana

    2013-01-01

    La presente tesis doctoral trata el análisis de suspensiones y emulsiones de materiales de cambio de fase para su uso como fluido caloportador y material de almacenamiento térmico. El interés de la tesis nace de la actual conyuntura energética. Dentro de la línea de búsqueda de un modelo energético sostenible, el almacenamiento térmico de energía contribuye a la utilización eficiente de la energía. Las aplicaciones del almacenamiento térmico de energía mediante cambio de fase sólido-líquido s...

  15. Donor-acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions.

    Science.gov (United States)

    Stergiou, Anastasios; Pagona, Georgia; Tagmatarchis, Nikos

    2014-01-01

    Graphene research and in particular the topic of chemical functionalization of graphene has exploded in the last decade. The main aim is to increase the solubility and thereby enhance the processability of the material, which is otherwise insoluble and inapplicable for technological applications when stacked in the form of graphite. To this end, initially, graphite was oxidized under harsh conditions to yield exfoliated graphene oxide sheets that are soluble in aqueous media and amenable to chemical modifications due to the presence of carboxylic acid groups at the edges of the lattice. However, it was obvious that the high-defect framework of graphene oxide cannot be readily utilized in applications that are governed by charge-transfer processes, for example, in solar cells. Alternatively, exfoliated graphene has been applied toward the realization of some donor-acceptor hybrid materials with photo- and/or electro-active components. The main body of research regarding obtaining donor-acceptor hybrid materials based on graphene to facilitate charge-transfer phenomena, which is reviewed here, concerns the incorporation of porphyrins and phthalocyanines onto graphene sheets. Through illustrative schemes, the preparation and most importantly the photophysical properties of such graphene-based ensembles will be described. Important parameters, such as the generation of the charge-separated state upon photoexcitation of the organic electron donor, the lifetimes of the charge-separation and charge-recombination as well as the incident-photon-to-current efficiency value for some donor-acceptor graphene-based hybrids, will be discussed.

  16. Nanoengineered materials for liquid-vapour phase-change heat transfer

    Science.gov (United States)

    Cho, H. Jeremy; Preston, Daniel J.; Zhu, Yangying; Wang, Evelyn N.

    2016-12-01

    Liquid-vapour phase change is a useful and efficient process to transfer energy in nature, as well as in numerous domestic and industrial applications. Relatively recent advances in altering surface chemistry, and in the formation of micro- and nanoscale features on surfaces, have led to exciting improvements in liquid-vapour phase-change performance and better understanding of the underlying science. In this Review, we present an overview of the surface, thermal and material science to illustrate how new materials and designs can improve boiling and condensation. There are many parallels between boiling and condensation, such as nucleation of a phase and its departure from a surface; however, the particular set of challenges associated with each phenomenon results in different material designs used in different manners. We also discuss alternative techniques, such as introducing heterogeneous surface chemistry or direct real-time manipulation of the phase-change process, which can offer further control of heat-transfer processes. Finally, long-term robustness is essential to ensure reliability and feasibility but remains a key challenge.

  17. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    Directory of Open Access Journals (Sweden)

    Marzieh Alikhasi

    2016-03-01

    Full Text Available Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials.Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE and 10 regular-body polyvinyl siloxane (PVS impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM. Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM. These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05.Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (P<0.001. Also, the open tray technique showed less angular displacement with the use of PVS impression material. Detail reproduction accuracy was the same in all the groups (P>0.05(.Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction.Keywords: Dental Implants; Dental Impression Materials, Dental Impression Technique

  18. Materials and Physics Challenges for Spin Transfer Torque Magnetic Random Access Memories

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, O.

    2014-10-05

    Magnetic random access memories utilizing the spin transfer torque effect for writing information are a strong contender for non-volatile memories scalable to the 20 nm node, and perhaps beyond. I will here examine how these devices behave as the device size is scaled down from 70 nm size to 20 nm. As device sizes go below ~50 nm, the size becomes comparable to intrinsic magnetic length scales and the device behavior does not simply scale with size. This has implications for the device design and puts additional constraints on the materials in the device.

  19. Transfer matrix method-based approach to study the bi-gyrotropic magnetic materials

    Science.gov (United States)

    Zamani, Mehdi; Hajesmaeili, Hamidreza Nezhad; Zandi, Mohammad Hossein

    2016-08-01

    Optical and magneto-optical (MO) responses in magnetic multilayer systems are calculated by transfer matrix method (TMM). In a bi-gyrotropic medium, electric permittivity (ε) and magnetic permeability (μ) coefficients are in the form of non-diagonal tensors, synchronously, which their non-diagonal elements refer to the existence of anisotropy in such medium. In the present study, in addition to present a TMM based-approach for bi-gyrotropic medium, numerical simulations for studying the amount of optical and MO parameters of the bi-gyrotropic Yttrium Iron Garnet (YIG) material, in both transmission and reflection configurations, have been done.

  20. High pressure induced charge transfer in 3d-4f bimetallic photomagnetic materials.

    Science.gov (United States)

    Wu, Lai-Chin; Nielsen, Morten Bormann; Bremholm, Martin; Madsen, Solveig Røgild; Overgaard, Jacob; Newville, Matt; Chen, Yu-Sheng; Iversen, Bo Brummerstedt

    2015-05-25

    Pressure-induced crystal color change of photo-magnetic materials [Ln(DMF)4(H2O)3(μ-CN)M(CN)5]·H2O, Ln = Y, M = Fe (1), Ln = Y, M = Co (2), Ln = Nd, M = Fe (3) (DMF = N,N-dimethyl formamide) are investigated using variable pressure X-ray Absorption Near-Edge Structure (XANES) spectroscopy and X-ray diffraction. For 1 the effect is caused by ligand-to-metal charge transfer (LMCT) on the iron site.

  1. Evaluation of Glass Density to Support the Estimation of Fissile Mass Loadings from Iron Concentrations in SB6 Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.; Peeler, D.

    2010-12-15

    The Department of Energy - Savannah River (DOE-SR) previously provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of the guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft{reg_sign} Excel{reg_sign} spreadsheet for the evaluation of fissile loading in Sludge Batch 5 glass based on the Fe concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that SRNL provide the necessary information to allow SRR to update the Excel spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 6 (SB6). One of the primary inputs into the fissile loading spreadsheet includes a bounding density for SB6-based glasses. Based on the measured density data of select SB6 variability study glasses, SRNL recommends that SRR utilize the 99/99 Upper Tolerance Limit (UTL) density value at 38% WL (2.823 g/cm{sup 3}) as a bounding density for SB6 glasses to assess the fissile concentration in this glass system. That is, the 2.823 g/cm{sup 3} is recommended as a key (and fixed) input into the fissile concentration spreadsheet for SB6 processing. It should be noted that no changes are needed to the underlying structure of the Excel based spreadsheet to support fissile assessments for SB6. However, SRR should update the other key inputs to the spreadsheet that are based on fissile and Fe concentrations reported from the SB6 Waste Acceptance Product Specification (WAPS) sample. The purpose of this technical report is to present the density measurements that were determined for the SB6 variability study glasses and to conduct a statistical evaluation of these measurements to provide a bounding density value that may be used as input to the Excel{reg_sign} spreadsheet to be employed by SRR to maintain the

  2. Protein standardization V: value transfer. A practical protocol for the assignment of serum protein values from a Reference Material to a Target Material.

    Science.gov (United States)

    Blirup-Jensen, Søren; Johnson, A Myron; Larsen, Marianne

    2008-01-01

    We present a practical protocol for the assignment of values to serum proteins in a Target Material using a Reference Material. This protocol is based on the model of Direct Value Transfer between serum matrices and is intended to improve the value assignment of commercial calibrators using the Reference Material CRM 470 (now labeled ERM-DA 470) or similar reference materials. The procedure describes the general as well as the practical principles involved in the value assignment (with examples). The practical transfer protocol is based on multiple assays of 6 dilutions of the Reference Material and 6 dilutions of the Target Material. The transfer protocol requires several measurements a day repeated on several days, an important prerequisite being that all reconstitutions and dilutions are controlled by weighing thus reducing uncertainty in the transfer. In open systems that allow the use of the Reference Material as calibrator and the Target Material as samples, the proportionality of the two materials (the presence or absence of matrix effects) can now be directly assessed by evaluating a single regression plot. If no matrix effects are found, the regression line will pass through zero with a slope equal to the ratio of the concentrations of the two materials. In closed systems, the dedicated commercial calibrator has to be used as such; the Reference Material and the Target Material are now assayed as samples against this calibrator. Two regression plots are therefore obtained; if no matrix effects are present among the two materials and the calibrator, both the Reference and Target Materials will show zero intercepts, and the ratio of the two slopes will equal the ratio of the concentrations.

  3. Modeling Granular Materials as Compressible Non-Linear Fluids: Heat Transfer Boundary Value Problems

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, M.C.; Tran, P.X.

    2006-01-01

    We discuss three boundary value problems in the flow and heat transfer analysis in flowing granular materials: (i) the flow down an inclined plane with radiation effects at the free surface; (ii) the natural convection flow between two heated vertical walls; (iii) the shearing motion between two horizontal flat plates with heat conduction. It is assumed that the material behaves like a continuum, similar to a compressible nonlinear fluid where the effects of density gradients are incorporated in the stress tensor. For a fully developed flow the equations are simplified to a system of three nonlinear ordinary differential equations. The equations are made dimensionless and a parametric study is performed where the effects of various dimensionless numbers representing the effects of heat conduction, viscous dissipation, radiation, and so forth are presented.

  4. TRANSFER

    African Journals Online (AJOL)

    “Chemistry Department, Kenyatta University, P. 0. Box 43844 ... harvester (X) [L 2] in a manner consistent with the following Forster equation for long range energy transfer [3-7]. .... sensitive foods, chemical reactors and essences. Recently we ...

  5. Charge transfer and triplet states in OPV materials and devices (Presentation Recording)

    Science.gov (United States)

    Dyakonov, Vladimir

    2015-10-01

    Electron back transfer (EBT), potentially occurring after electron transfer from donor to acceptor may populate the lower lying donor or acceptor triplet state and serve as recombination channel.[1] Here we report on studies of charge transfer and triplet states in blends of highly efficient benzodithiophene PTB7 polymer in combination with the fullerene-derivative PC71BM using the spin sensitive optically detected magnetic resonance (ODMR) technique and compare the results with those obtained in P3HT (poly(3- hexylthiophene):PC61BM blends. Although PTB7:PC71BM absorbers yield much higher power conversion efficiencies in solar cells exceeding 7%, we found a significant increase of triplet exciton generation, which was absent in the P3HT based blends. We discuss this observation within the EBT scenario with the emphasis on the influence of morphology, fullerene load, HOMO/LUMO energy and presence of additives (DIO). Suppressing the EBT process by morphology and/or energetics of polymer and molecules is important to achieve the full potential of highly efficient OPV materials. [1] M. Liedtke, et al., JACS 133, 9088 (2011).

  6. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    Science.gov (United States)

    Alikhasi, Marzieh; Siadat, Hakimeh; Kharazifard, Mohammad Javad

    2015-01-01

    Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl siloxane (PVS) impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM). Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM). These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05. Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (Ptray technique showed less angular displacement with the use of PVS impression material. Detail reproduction accuracy was the same in all the groups (P>0.05). Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction. PMID:27252761

  7. Study of Heat Transfer in a Kapok Material from the Convective Heat Transfer Coefficient and the Excitation Pulse of Solicitations External Climatic

    Directory of Open Access Journals (Sweden)

    M. Dieng

    2013-02-01

    Full Text Available The aim of this study is to characterize thermal insulating local material, kapok, from a study in 3 dimensions in Cartesian coordinate and in dynamic frequency regime. From a study a 3 dimensional the heat transfer through a material made of wool kapok (thermal conductivity: &lambda = 0,035 W/m/K; density: &rho = 12, 35 kg/m3; thermal diffusivity: &alpha = 17, 1.10-7 m2 /s is presented. The evolution curves of temperature versus convective heat transfer coefficient have helped highlight the importance of pulse excitation and the depth in the material. The thermal impedance is studied from representations of Nyquist and Bode diagrams allowing characterizing the thermal behavior from thermistors. The evolution of the thermal impedance with the thermal capacity of the material is presented.

  8. Hierarchical Materials Design by Pattern Transfer Printing of Self-Assembled Binary Nanocrystal Superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Paik, Taejong; Yun, Hongseok; Fleury, Blaise; Hong, Sung-Hoon; Jo, Pil Sung; Wu, Yaoting; Oh, Soong-Ju; Cargnello, Matteo; Yang, Haoran; Murray, Christopher B.; Kagan, Cherie R.

    2017-02-08

    We demonstrate the fabrication of hierarchical materials by controlling the structure of highly ordered binary nanocrystal superlattices (BNSLs) on multiple length scales. Combinations of magnetic, plasmonic, semiconducting, and insulating colloidal nanocrystal (NC) building blocks are self-assembled into BNSL membranes via the liquid–interfacial assembly technique. Free-standing BNSL membranes are transferred onto topographically structured poly(dimethylsiloxane) molds via the Langmuir–Schaefer technique and then deposited in patterns onto substrates via transfer printing. BNSLs with different structural motifs are successfully patterned into various meso- and microstructures such as lines, circles, and even three-dimensional grids across large-area substrates. A combination of electron microscopy and grazing incidence small-angle X-ray scattering (GISAXS) measurements confirm the ordering of NC building blocks in meso- and micropatterned BNSLs. This technique demonstrates structural diversity in the design of hierarchical materials by assembling BNSLs from NC building blocks of different composition and size by patterning BNSLs into various size and shape superstructures of interest for a broad range of applications.

  9. Correlation between charge transfer and exchange coupling in carbon-based magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Anh Tuan, E-mail: tuanna@hus.edu.vn [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Science and Technology Department, Vietnam National University, Hanoi, 144 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292 Japan (Japan); Nguyen, Van Thanh; Nguyen, Huy Sinh [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Pham, Thi Tuan Anh [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Faculty of Science, College of Hai Duong, Nguyen Thi Due, Hai Duong (Viet Nam); Do, Viet Thang [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Faculty of Science, Haiphong University, 171 Phan Dang Luu, Kien An, Hai Phong (Viet Nam); Dam, Hieu Chi [Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292 Japan (Japan)

    2015-10-15

    Several forms of carbon-based magnetic materials, i.e. single radicals, radical dimers, and alternating stacks of radicals and diamagnetic molecules, have been investigated using density-functional theory with dispersion correction and full geometry optimization. Our calculated results demonstrate that the C{sub 31}H{sub 15} (R{sub 4}) radical has a spin of ½. However, in its [R{sub 4}]{sub 2} dimer structure, the net spin becomes zero due to antiferromagnetic spin-exchange between radicals. To avoid antiferromagnetic spin-exchange of identical face-to-face radicals, eight alternating stacks, R{sub 4}/D{sub 2m}/R{sub 4} (with m = 3-10), were designed. Our calculated results show that charge transfer (Δn) between R{sub 4} radicals and the diamagnetic molecule D{sub 2m} occurs with a mechanism of spin exchange (J) in stacks. The more electrons that transfer from R{sub 4} to D{sub 2m}, the stronger the ferromagnetic spin-exchange in stacks. In addition, our calculated results show that Δn can be tailored by adjusting the electron affinity (E{sub a}) of D{sub 2m}. The correlation between Δn, E{sub a}, m, and J is discussed. These results give some hints for the design of new ferromagnetic carbon-based materials.

  10. Hierarchical Materials Design by Pattern Transfer Printing of Self-Assembled Binary Nanocrystal Superlattices.

    Science.gov (United States)

    Paik, Taejong; Yun, Hongseok; Fleury, Blaise; Hong, Sung-Hoon; Jo, Pil Sung; Wu, Yaoting; Oh, Soong-Ju; Cargnello, Matteo; Yang, Haoran; Murray, Christopher B; Kagan, Cherie R

    2017-03-08

    We demonstrate the fabrication of hierarchical materials by controlling the structure of highly ordered binary nanocrystal superlattices (BNSLs) on multiple length scales. Combinations of magnetic, plasmonic, semiconducting, and insulating colloidal nanocrystal (NC) building blocks are self-assembled into BNSL membranes via the liquid-interfacial assembly technique. Free-standing BNSL membranes are transferred onto topographically structured poly(dimethylsiloxane) molds via the Langmuir-Schaefer technique and then deposited in patterns onto substrates via transfer printing. BNSLs with different structural motifs are successfully patterned into various meso- and microstructures such as lines, circles, and even three-dimensional grids across large-area substrates. A combination of electron microscopy and grazing incidence small-angle X-ray scattering (GISAXS) measurements confirm the ordering of NC building blocks in meso- and micropatterned BNSLs. This technique demonstrates structural diversity in the design of hierarchical materials by assembling BNSLs from NC building blocks of different composition and size by patterning BNSLs into various size and shape superstructures of interest for a broad range of applications.

  11. Simulation Analysis of Geometry Condition Influence on Fissile Material n/γPulse Shape Discrimination%裂变材料中子-伽马脉冲形状甄别几何条件影响的模拟分析

    Institute of Scientific and Technical Information of China (English)

    林洪涛; 张全虎; 黎素芬; 李井怀

    2014-01-01

    快中子多重性分析技术是当前核材料衡算领域的热门研究方向。针对中子伽马脉冲形状甄别的效果在探测距离很近时明显变差的实验现象展开了研究。使用GEANT4工具箱模拟了液体闪烁体探测器测量裂变中子伽马的粒子输运过程,并基于计算机模拟数据分析了使用BC-501 A液体闪烁体探测器测量裂变中子时,裂变物质与探测器的距离(几何效率)对中子-伽马甄别效果的影响。分析的结果与实验现象相符,表明在基于液体闪烁体探测器的核材料属性测量中,若单个探头的探测效率较高,裂变中子伽马脉冲叠加会严重影响甄别结果和测量计数。%Fast Neutron Multiplicity Counting has drawn much attention from nuclear material accounting .The reason of bad pulse shape discrimination (PSD) result in near detection is studied .With GEANT4 toolkit, a simulation of the particle transport process of detecting fission neutron and gamma with liquid scintillator was re -alized .Based on the simulation data , the impact of the distance between nuclear material and the detector ( ge-ometry efficiency ) on the PSD in measuring fission neutron by BC -501 A liquid scintillator is discussed in de-tail.The analysis result is generally consistent with the experiment .The analysis show that if the detection effi-ciency of single detector is high , the pile up neutron and gamma may seriously affect the discrimination result and measurement counts.

  12. Numerical analysis of heat, air, and moisture transfers in a wooden building material

    Directory of Open Access Journals (Sweden)

    Mnasri Faiza

    2017-01-01

    Full Text Available The present paper aims to predict the hygrothermal behavior of massive wood panel considered as bio-based building material. In this context, we developed a macroscopic model coupled no linear heat, air, and moisture transfers that incorporates simultaneously the effect of thermal diffusion and infiltration phenomenon on the building material. The model inputs parameters were evaluated experimentally according to the recognized standards of material’s characterization. Therefore, numerous series of hygrothermal calculation were carried out on the 1-D and 2-D configuration in order to assess the dimensionless effect on such wooden material. Two types of boundary conditions were considered and examined. The first are at the material scale of wood drying process. The second type of conditions is at the wall scale, where the conditions of the building ambiance are considered. Moreover, the model sensitivity to the driving potentials coupling and to the parameters variability was considered and examined. It has been found that the coupling in the model had a remarkable impact on both kinetics of temperature and moisture content.

  13. Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

    Directory of Open Access Journals (Sweden)

    Anastasios Stergiou

    2014-09-01

    Full Text Available Graphene research and in particular the topic of chemical functionalization of graphene has exploded in the last decade. The main aim is to increase the solubility and thereby enhance the processability of the material, which is otherwise insoluble and inapplicable for technological applications when stacked in the form of graphite. To this end, initially, graphite was oxidized under harsh conditions to yield exfoliated graphene oxide sheets that are soluble in aqueous media and amenable to chemical modifications due to the presence of carboxylic acid groups at the edges of the lattice. However, it was obvious that the high-defect framework of graphene oxide cannot be readily utilized in applications that are governed by charge-transfer processes, for example, in solar cells. Alternatively, exfoliated graphene has been applied toward the realization of some donor–acceptor hybrid materials with photo- and/or electro-active components. The main body of research regarding obtaining donor–acceptor hybrid materials based on graphene to facilitate charge-transfer phenomena, which is reviewed here, concerns the incorporation of porphyrins and phthalocyanines onto graphene sheets. Through illustrative schemes, the preparation and most importantly the photophysical properties of such graphene-based ensembles will be described. Important parameters, such as the generation of the charge-separated state upon photoexcitation of the organic electron donor, the lifetimes of the charge-separation and charge-recombination as well as the incident-photon-to-current efficiency value for some donor–acceptor graphene-based hybrids, will be discussed.

  14. Numerical Simulation for Effects of Microcapsuled Phase Change Material (mpcm) Distribution on Heat and Moisture Transfer in Porous Textiles

    Science.gov (United States)

    Li, Fengzhi

    In recent years, the use of phase change materials (PCM) to improve heat and moisture transfer properties of clothing has gained considerable attention. The PCM distribution in the clothing impacts heat and moisture transfer properties of the clothing significantly. For describing the mechanisms of heat and moisture transfer in clothing with PCM and investigating the effect of the PCM distribution, a new dynamic model of coupled heat and moisture transfer in porous textiles with PCM was developed. The effect of water content on physical parameters of textiles and heat transfer with phase change in the PCM microcapsules were considered in the model. Meanwhile, the numerical predictions were compared with experimental data, and good agreement was observed between the two, indicating that the model was satisfactory. Also the effects of the PCM distribution on heat transfer in the textiles-PCM microcapsule composites were investigated by using the model.

  15. Influence of temperature-dependent material properties on heat transfer in the turbulent flow over a flat plate

    Science.gov (United States)

    Wehle, F.; Brandt, F.

    The influence of temperature dependence of material properties on heat transfer in a turbulent plate boundary layer is investigated using differential equations for the velocity and temperature fields of even, steady, and compressible boundary layer flows. The results are compared with the well-known material property correction factors of Zhukauskas (1966), Sieder and Tate (1936), and Hufschmidt and Bruck (1968).

  16. Development of a new simulation code for evaluation of criticality transients involving fissile solution boiling

    Energy Technology Data Exchange (ETDEWEB)

    Basoglu, Benan; Yamamoto, Toshihiro; Okuno, Hiroshi; Nomura, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In this work, we report on the development of a new computer code named TRACE for predicting the excursion characteristics of criticality excursions involving fissile solutions. TRACE employs point neutronics coupled with simple thermal-hydraulics. The temperature, the radiolytic gas effects, and the boiling phenomena are estimated using the transient heat conduction equation, a lumped-parameter energy model, and a simple boiling model, respectively. To evaluate the model, we compared our results with the results of CRAC experiments. The agreement in these comparisons is quite satisfactory. (author)

  17. Prompt neutron fission spectrum mean energies for the fissile nuclides and /sup 252/Cf

    Energy Technology Data Exchange (ETDEWEB)

    Holden, N.E.

    1985-01-01

    The international standard for a neutron spectrum is that produced from the spontaneous fission of /sup 252/Cf, while the thermal neutron induced fission neutron spectra for the four fissile nuclides, /sup 233/U, /sup 235/U, /sup 239/Pu, and /sup 241/Pu are of interest from the standpoint of nuclear reactors. The average neutron energies of these spectra are tabulated. The individual measurements are recorded with the neutron energy range measured, the method of detection as well as the average neutron energy for each author. Also tabulated are the measurements of the ratio of mean energies for pairs of fission neutron spectra. 75 refs., 9 tabs. (LEW)

  18. Development of a new simulation code for evaluation of criticality transients involving fissile solution boiling

    Energy Technology Data Exchange (ETDEWEB)

    Basoglu, Benan; Yamamoto, Toshihiro; Okuno, Hiroshi; Nomura, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In this work, we report on the development of a new computer code named TRACE for predicting the excursion characteristics of criticality excursions involving fissile solutions. TRACE employs point neutronics coupled with simple thermal-hydraulics. The temperature, the radiolytic gas effects, and the boiling phenomena are estimated using the transient heat conduction equation, a lumped-parameter energy model, and a simple boiling model, respectively. To evaluate the model, we compared our results with the results of CRAC experiments. The agreement in these comparisons is quite satisfactory. (author)

  19. Nuclear dissipation effects on fission and evaporation in systems of intermediate fissility

    Directory of Open Access Journals (Sweden)

    Gelli N.

    2010-03-01

    Full Text Available The systems of intermediate fissility 132Ce and 158Er have been studied experimentally and theoretically in order to investigate the dissipation properties of nuclear matter. Cross sections of fusion-fission and evaporation residues channels together with charged particles multiplicities in both channels, their spectra, angular correlations and mass-energy distribution of fission fragments have been measured. Theoretical analysis has been performed using multi-dimensional stochastic approach with realistic treatment of particle evaporation. The results of analysis show that full one-body or unusually strong two-body dissipation allows to reproduce experimental data. No temperature dependent dissipation was needed.

  20. Transfer matrix modeling and experimental validation of cellular porous material with resonant inclusions.

    Science.gov (United States)

    Doutres, Olivier; Atalla, Noureddine; Osman, Haisam

    2015-06-01

    Porous materials are widely used for improving sound absorption and sound transmission loss of vibrating structures. However, their efficiency is limited to medium and high frequencies of sound. A solution for improving their low frequency behavior while keeping an acceptable thickness is to embed resonant structures such as Helmholtz resonators (HRs). This work investigates the absorption and transmission acoustic performances of a cellular porous material with a two-dimensional periodic arrangement of HR inclusions. A low frequency model of a resonant periodic unit cell based on the parallel transfer matrix method is presented. The model is validated by comparison with impedance tube measurements and simulations based on both the finite element method and a homogenization based model. At the HR resonance frequency (i) the transmission loss is greatly improved and (ii) the sound absorption of the foam can be either decreased or improved depending on the HR tuning frequency and on the thickness and properties of the host foam. Finally, the diffuse field sound absorption and diffuse field sound transmission loss performance of a 2.6 m(2) resonant cellular material are measured. It is shown that the improvements observed at the Helmholtz resonant frequency on a single cell are confirmed at a larger scale.

  1. Fluorescent material concentration dependency: Förster resonance energy transfer in quasi-solid state DSSCs

    Science.gov (United States)

    Kim, Dong Woo; Jo, Hyun-Jun; Thogiti, Suresh; Yang, Weon Ki; Cheruku, Rajesh; Kim, Jae Hong

    2017-03-01

    Förster resonance energy transfer (FRET) is critical for wide spectral absorption, an increased dye loading, and photocurrent generation of dye-sensitized solar cells (DSSCs). This process consists of organic fluorescent materials (as an energy donor), and an organic dye (as an energy acceptor on TiO2 surfaces) with quasi-solid electrolyte. The judicious choice of the energy donor and acceptor facilitates a strong spectral overlap between the emission and absorption regions of the fluorescent materials and dye. This FRET process enhances the light-harvesting characteristics of quasi-solid state DSSCs. In this study, DSSCs containing different concentrations (0, 1, and 1.5 wt%) of a fluorescent material (FM) as the energy donor are investigated using FRET. The power conversion efficiency of DSSCs containing FMs in a quasi-solid electrolyte increased by 33% over a pristine cell. The optimized cell fabricated with the quasi-solid state DSSC containing 1.0 wt% FM shows a maximum efficiency of 3.38%, with a short-circuit current density (J SC ) of 4.32 mA/cm-2, and an open-circuit voltage (V OC ) of 0.68 V under illumination of simulated solar light (AM 1.5G, 100 mW/cm-2). [Figure not available: see fulltext.

  2. Heat Transfer of Heat Sinking Vest with Phase-change Material

    Institute of Scientific and Technical Information of China (English)

    QIU Yifen; JIANG Nan; WU Wei; ZHANG Guangwei; XIAO Baoliang

    2011-01-01

    To investigate thermal protection effects of heat sinking vest with phase-change material (PCM),human thermoregulation model is introduced,and a thermal mathematical model of heat transfer with phase change has been developed with the enthalpy method.The uniform energy equation is constructed for the whole domain,and the equation is implicitly discreted by control volume and finite difference method.Then the enthalpy in each node is solved by using chasing method to calculate the tridiagonal equations,and the inner surface temperature of PCM could be obtained.According to the human thermoregulation model of heat sinking vest,the dynamic temperature distribution and sweat of the body are solved.Calculation results indicate that the change of core temperature matches the experimental result,and the sweat difference is small.This thermal mathematical model of heat transfer with phase change is credible and appropriate.Through comparing the dynamic temperature distribution and sweat of the body wearing heat sinking vest to results of the body not wearing this clothing,it is evident that wearing heat sinking vest can reduce the body heat load significantly.

  3. Fluid flow modeling of resin transfer molding for composite material wind turbine blade structures.

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, Douglas S. (Montana State University, Bozeman, MT); Rossel, Scott M. (Montana State University, Bozeman, MT)

    2004-06-01

    Resin transfer molding (RTM) is a closed mold process for making composite materials. It has the potential to produce parts more cost effectively than hand lay-up or other methods. However, fluid flow tends to be unpredictable and parts the size of a wind turbine blade are difficult to engineer without some predictive method for resin flow. There were five goals of this study. The first was to determine permeabilities for three fabrics commonly used for RTM over a useful range of fiber volume fractions. Next, relations to estimate permeabilities in mixed fabric lay-ups were evaluated. Flow in blade substructures was analyzed and compared to predictions. Flow in a full-scale blade was predicted and substructure results were used to validate the accuracy of a full-scale blade prediction.

  4. Modeling of Heat Transfer and Ablation of Refractory Material Due to Rocket Plume Impingement

    Science.gov (United States)

    Harris, Michael F.; Vu, Bruce T.

    2012-01-01

    CR Tech's Thermal Desktop-SINDA/FLUINT software was used in the thermal analysis of a flame deflector design for Launch Complex 39B at Kennedy Space Center, Florida. The analysis of the flame deflector takes into account heat transfer due to plume impingement from expected vehicles to be launched at KSC. The heat flux from the plume was computed using computational fluid dynamics provided by Ames Research Center in Moffet Field, California. The results from the CFD solutions were mapped onto a 3-D Thermal Desktop model of the flame deflector using the boundary condition mapping capabilities in Thermal Desktop. The ablation subroutine in SINDA/FLUINT was then used to model the ablation of the refractory material.

  5. Investigation of Electron Transfer-Based Photonic and Electro-Optic Materials and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Bromenshenk, Jerry J; Abbott, Edwin H; Dickensheets, David; Donovan, Richard P; Hobbs, J D; Spangler, Lee; McGuirl, Michele A; Spangler, Charles; Rebane, Aleksander; Rosenburg, Edward; Schmidt, V H; Singel, David J

    2008-03-28

    Montana's state program began its sixth year in 2006. The project's research cluster focused on physical, chemical, and biological materials that exhibit unique electron-transfer properties. Our investigators have filed several patents and have also have established five spin-off businesses (3 MSU, 2 UM) and a research center (MT Tech). In addition, this project involved faculty and students at three campuses (MSU, UM, MT Tech) and has a number of under-represented students, including 10 women and 5 Native Americans. In 2006, there was an added emphasis on exporting seminars and speakers via the Internet from UM to Chief Dull Knife Community College, as well as work with the MT Department of Commerce to better educate our faculty regarding establishing small businesses, licensing and patent issues, and SBIR program opportunities.

  6. Thermal transfer in graphene-interfaced materials: contact resistance and interface engineering.

    Science.gov (United States)

    Wang, Hanxiong; Gong, Jixuan; Pei, Yongmao; Xu, Zhiping

    2013-04-10

    We investigate here heat transfer across interfaces consisting of single- and few-layer graphene sheets between silicon carbides by performing nonequilibrium molecular dynamics simulations. The interfacial thermal conducitivity κI is calculated by considering graphene layers as an interfacial phase. The results indicate that κI decreases with its thickness and heat flux but increases with the environmental temperature. Interface engineering of κI is explored by intercalating molecules between graphene layers. These guest molecules decouple electronic states across the interface, but tune κI slightly, leading to a thermally transparent but electronically insulating interface. These results provide a fundamental understanding in thermal transport across weakly bound interfaces, and design recipes for multifunctional thermal interface materials, composites and thermal management in graphene-based devices.

  7. Nanostructured 2D cellular materials in silicon by sidewall transfer lithography NEMS

    Science.gov (United States)

    Syms, Richard R. A.; Liu, Dixi; Ahmad, Munir M.

    2017-07-01

    Sidewall transfer lithography (STL) is demonstrated as a method for parallel fabrication of 2D nanostructured cellular solids in single-crystal silicon. The linear mechanical properties of four lattices (perfect and defected diamond; singly and doubly periodic honeycomb) with low effective Young’s moduli and effective Poisson’s ratio ranging from positive to negative are modelled using analytic theory and the matrix stiffness method with an emphasis on boundary effects. The lattices are fabricated with a minimum feature size of 100 nm and an aspect ratio of 40:1 using single- and double-level STL and deep reactive ion etching of bonded silicon-on-insulator. Nanoelectromechanical systems (NEMS) containing cellular materials are used to demonstrate stretching, bending and brittle fracture. Predicted edge effects are observed, theoretical values of Poisson’s ratio are verified and failure patterns are described.

  8. APPLICATION OF NOVEL NEUTRON CORRELATION TECHNIQUES TO NUCLEAR MATERIAL MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Sale, K

    2006-06-09

    Confirmation of the fissile mass of a system containing plutonium can be done using neutron multiplicity techniques. This can be accomplished with a detector system that is smaller and less costly than a standard neutron multiplicity counter (NMC). Also the fissile mass of a uranium containing system can be confirmed by passive means. Recent work at Lawrence Livermore National Laboratory has demonstrated that simple slab neutron detectors and a novel approach to data acquisition and analysis can be used to make an accurate measurement of the mass of fissile materials. Purely passive measurement of kilogram quantities of highly enriched uranium (HEU) have also been shown to be feasible. In this paper we discuss calculational tools for assessing the application of these techniques to fissile material transparency regimes. The tools required to adequately model the correlations and their application will be discussed.

  9. Mass transfer in mesoporous materials: the benefit of microscopic diffusion measurement.

    Science.gov (United States)

    Kärger, Jörg; Valiullin, Rustem

    2013-05-01

    We introduce the various options of experimentally observing mass transfer in mesoporous materials. It shall be demonstrated that the exploration of the underlying mechanisms is excessively complicated by the complexity of the phenomena contributing to molecular transport in such systems and their mutual interdependence. Microscopic diffusion measurement by the pulsed field gradient (PFG) technique of NMR offers the unique option to measure both the relative amount of molecules adsorbed and the probability distribution of their displacements over space scales relevant to fundamental adsorption science just as for technological application. These advantages are shown to have cared for a recent breakthrough in our understanding. The examples presented include the measurement of diffusion in purely mesoporous materials and the rationalization of the complex concentration patterns revealed by such studies on the basis of suitably chosen micro-kinetic models. As an interesting feature, transition into the supercritical state is shown to become directly observable by monitoring a jump in the diffusivities during temperature enhancement, occurring at temperatures notably below the bulk critical temperature. PFG NMR studies with hierarchical materials are shown to permit selective diffusion measurement with each of the involved subspaces, in parallel with the measurement of the overall diffusivity as the key parameter for the technological exploitation of such materials. We refer to the occurrence of diffusion hysteresis as a novel phenomenon, found to accompany phase transitions quite in general. Though further complicating the measuring procedure and the correlation between experimental observation and the underlying mechanisms, diffusion hysteresis is doubtlessly among the new options provided by diffusion studies for gaining deeper insight into the structure and dynamics of complex porous systems.

  10. Development of a poly(dimethylacrylamide) based matrix material for solid phase high density peptide array synthesis employing a laser based material transfer

    Science.gov (United States)

    Ridder, Barbara; Foertsch, Tobias C.; Welle, Alexander; Mattes, Daniela S.; von Bojnicic-Kninski, Clemens M.; Loeffler, Felix F.; Nesterov-Mueller, Alexander; Meier, Michael A. R.; Breitling, Frank

    2016-12-01

    Poly(dimethylacrylamide) (PDMA) based matrix materials were developed for laser-based in situ solid phase peptide synthesis to produce high density arrays. In this specific array synthesis approach, amino acid derivatives are embedded into a matrix material, serving as a "solid" solvent material at room temperature. Then, a laser pulse transfers this mixture to the target position on a synthesis slide, where the peptide array is synthesized. Upon heating above the glass transition temperature of the matrix material, it softens, allowing diffusion of the amino acid derivatives to the synthesis surface and serving as a solvent for peptide bond formation. Here, we synthesized PDMA six-arm star polymers, offering the desired matrix material properties, using atom transfer radical polymerization. With the synthesized polymers as matrix material, we structured and synthesized arrays with combinatorial laser transfer. With densities of up to 20,000 peptide spots per cm2, the resolution could be increased compared to the commercially available standard matrix material. Time-of-Flight Secondary Ion Mass Spectrometry experiments revealed the penetration behavior of an amino acid derivative into the prepared acceptor synthesis surface and the effectiveness of the washing protocols.

  11. High-pressure {sup 4}He drift tubes for fissile material detection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui, E-mail: zwang@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Morris, Christopher L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Gray, F.E. [Regis University, Denver, CO 80221 (United States); Bacon, J.D.; Brockwell, M.I.; Chang, D.Y.; Chung, K.; Dai, W.G.; Greene, S.J.; Hogan, G.E.; Lisowski, P.W.; Makela, M.F.; Mariam, F.G.; McGaughey, P.L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mendenhall, M. [California Institute of Technology, Pasadena, CA 91125 (United States); Milner, E.C.; Miyadera, H.; Murray, M.M.; Perry, J.O.; Roybal, J.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); and others

    2013-03-01

    A detector efficiency model based on energy extraction from neutrons is described and used to compare {sup 4}He detectors with liquid scintillators (EJ301/NE-213). Detector efficiency can be divided into three regimes: single neutron scattering, multiple neutron scattering, and a transition regime in-between. For an average fission neutron of 2 MeV, the amount of {sup 4}He needed would be about 1/4 of the amount of the mass of EJ301/NE-213 in the single-scattering regime. For about 50% neutron energy extraction (1 MeV out of 2 MeV), the two types of detectors ({sup 4}He in the transition regime, EJ301 still in the single-scattering regime) have comparable mass, but {sup 4}He detectors can be much larger depending on the number density. A six-tube 11-bar-pressure {sup 4}He detector prototype is built and tested. Individual electrical pulses from the detector are recorded using a 12-bit digitizer. Differences in pulse rise time and amplitudes, due to different energy loss of neutrons and gamma rays, are used for neutron/gamma separation. Several energy spectra are also obtained and analyzed.

  12. Interaction of Radiation with Graphene Based Nanomaterials for Sensing Fissile Materials

    Science.gov (United States)

    2016-03-01

    proceedings articles for this award for this reporting period 7 Enter number of published books or chapter of books for this reporting period 8...the operation wavelength of the graphene-metal plasmonic hybrid devices from mid-IR to near-IR by using dolmen structure design. An effective...under “ Books , or other non- periodical, one-time publications.”Identify for each publication: Author(s), title, journal, volume, year, page numbers

  13. Ultraslow Wave Nuclear Burning of Uranium-Plutonium Fissile Medium on Epithermal Neutrons

    CERN Document Server

    Rusov, V D; Eingorn, M V; Chernezhenko, S A; Kakaev, A A

    2014-01-01

    For a fissile medium, originally consisting of uranium-238, the investigation of fulfillment of the wave burning criterion in a wide range of neutron energies is conducted for the first time, and a possibility of wave nuclear burning not only in the region of fast neutrons, but also for cold, epithermal and resonance ones is discovered for the first time. For the first time the results of the investigation of the Feoktistov criterion fulfillment for a fissile medium, originally consisting of uranium-238 dioxide with enrichments 4.38%, 2.00%, 1.00%, 0.71% and 0.50% with respect to uranium-235, in the region of neutron energies 0.015-10.0eV are presented. These results indicate a possibility of ultraslow wave neutron-nuclear burning mode realization in the uranium-plutonium media, originally (before the wave initiation by external neutron source) having enrichments with respect to uranium-235, corresponding to the subcritical state, in the regions of cold, thermal, epithermal and resonance neutrons. In order to...

  14. Max Phase Materials And Coatings For High Temperature Heat Transfer Applications

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Rodriguez, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Olson, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fuentes, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-19

    Molten salts have been used as heat transfer fluids in a variety of applications within proposed Gen IV nuclear designs and in advanced power system such as Concentrating Solar Power (CSP). However, operating at elevated temperatures can cause corrosion in many materials. This work developed coating technologies for MAX phase materials on Haynes-230 and characterized the corrosion of the coatings in the presence of commercial MgCl2-KCl molten salt. Cold spraying of Ti2AlC and physical vapor deposition (PVD) of Ti2AlC or Zr2AlC were tested to determine the most effective form of coating MAX phases on structural substrates. Corrosion testing at 850°C for 100 hrs showed that 3.9 μm Ti2AlC by PVD was slightly protective while 117 μm Ti2AlC by cold spray and 3.6 μm Zr2AlC by PVD were completely protective. None of the tests showed decomposition of the coating (Ti or Zr) into the salt

  15. Study on metal microparticle content of the material transferred with Absorbing Film Assisted Laser Induced Forward Transfer when using silver absorbing layer

    Energy Technology Data Exchange (ETDEWEB)

    Smausz, T. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary)]. E-mail: tomi@physx.u-szeged.hu; Hopp, B. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Kecskemeti, G. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Bor, Z. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary)

    2006-04-30

    Absorbing Film Assisted Laser Induced Forward Transfer (AFA-LIFT) is a modified LIFT method where a high absorption coefficient thin film coating of a transparent substrate is used to transform the laser energy into kinetic in order to transfer the 'target' material spread on it. This method can be used for the transfer of biomaterials and living cells, which could be damaged by direct irradiation of the laser beam. In previous experiments, {approx}50-100 nm thick metal films have been used as absorbing layer. The transferred material can also contain metal microparticles originating from the absorbing thin film and acting as non-desired impurities in some cases. The aim of our work was to study how the properties (number, size and covered area) of metal particles transferred during the AFA-LIFT process depend on film thickness and the applied fluence. Silver thin films with different thickness (50-400 nm) were used as absorbing layers and real experimental conditions were modeled by a 100 {mu}m thick water layer. The particles transferred without the use of water layer were also studied. The threshold laser fluence for the complete removal of the absorber from the irradiated area was found to strongly increase with increasing film thickness. The deposited micrometer and submicrometer particles were observed with optical microscope and atomic force microscope. Their size ranged from 100 nm to 20 {mu}m and depended on the laser fluence. The increase in fluence resulted in an increasing number of particles of smaller average size.

  16. Feasibility study of fissile mass quantification by photofission delayed gamma rays in radioactive waste packages using MCNPX

    Science.gov (United States)

    Simon, Eric; Jallu, Fanny; Pérot, Bertrand; Plumeri, Stéphane

    2016-12-01

    The feasibility of fissile mass quantification in large, long-lived medium activity radioactive waste packages using photofission delayed gamma rays has been assessed with MCNPX. The detection limit achievable is lower than the expected uranium mass in these waste packages, but the important sensibility to the waste matrix density and sample localization imposes to get an accurate measurement of these parameters. An isotope discrimination method based on gamma-ray ratios has been evaluated showing that photofission delayed gamma rays can be used to measure the fissile mass as well as the total uranium mass.

  17. Dynamic Control of Radiative Heat Transfer with Tunable Materials for Thermal Management in Both Far and Near Fields

    Science.gov (United States)

    Yang, Yue

    The proposed research mainly focuses on employing tunable materials to achieve dynamic control of radiative heat transfer in both far and near fields for thermal management. Vanadium dioxide (VO2), which undergoes a phase transition from insulator to metal at the temperature of 341 K, is one tunable material being applied. The other one is graphene, whose optical properties can be tuned by chemical potential through external bias or chemical doping. (Abstract shortened by ProQuest.).

  18. Numerical Heat Transfer Studies of a Latent Heat Storage System Containing Nano-Enhanced Phase Change Material

    Directory of Open Access Journals (Sweden)

    S F Hosseinizadeh

    2011-01-01

    Full Text Available The heat transfer enhancement in the latent heat thermal energy storage system through dispersion of nanoparticle is reported. The resulting nanoparticle-enhanced phase change materials (NEPCM exhibit enhanced thermal conductivity in comparison to the base material. The effects of nanoparticle volume fraction and some other parameters such as natural convection are studied in terms of solid fraction and the shape of the solid-liquid phase front. It has been found that higher nanoparticle volume fraction result in a larger solid fraction. The present results illustrate that the suspended nanoparticles substantially increase the heat transfer rate and also the nanofluid heat transfer rate increases with an increase in the nanoparticles volume fraction. The increase of the heat release rate of the NEPCM shows its great potential for diverse thermal energy storage application.

  19. Physical aspects of the pulsed laser deposition technique: The stoichiometric transfer of material from target to film

    DEFF Research Database (Denmark)

    Schou, Jørgen

    2009-01-01

    The physical processes of pulsed laser deposition (PLD) change strongly from the initial light absorption in a target to the final deposition and growth of a film. One of the primary advantages of PLD is the stoichiometric transfer of material from target to a film on a substrate. Even for a stoi...

  20. Lithium Ion Coupled Electron-Transfer Rates in Superconcentrated Electrolytes: Exploring the Bottlenecks for Fast Charge-Transfer Rates with LiMn2O4 Cathode Materials.

    Science.gov (United States)

    Nikitina, Victoria A; Zakharkin, Maxim V; Vassiliev, Sergey Yu; Yashina, Lada V; Antipov, Evgeny V; Stevenson, Keith J

    2017-09-19

    The charge-transfer kinetics of lithium ion intercalation into LixMn2O4 cathode materials was examined in dilute and concentrated aqueous and carbonate LiTFSI solutions using electrochemical methods. Distinctive trends in ion intercalation rates were observed between water-based and ethylene carbonate/diethyl carbonate solutions. The influence of the solution concentration on the rate of lithium ion transfer in aqueous media can be tentatively attributed to the process associated with Mn dissolution, whereas in carbonate solutions the rate is influenced by the formation of a concentration-dependent solid electrolyte interface (SEI). Some indications of SEI layer formation at electrode surfaces in carbonate solutions after cycling are detected by X-ray photoelectron spectroscopy. The general consequences related to the application of superconcentrated electrolytes for use in advanced energy storage cathodes are outlined and discussed.

  1. Heat transfer characteristics of d-mannitol as a phase change material for a medium thermal energy system

    Science.gov (United States)

    Shibahara, Makoto; Liu, Qiusheng; Fukuda, Katsuya

    2016-09-01

    Melting process and heat transfer characteristics of d-mannitol were investigated experimentally and numerically to construct a fundamental database of the waste heat recovery systems for ships. d-Mannitol which has relatively high latent heat was selected in this study as a phase-change material for medium thermal energy storage. Experimental results indicate that the melting temperature and latent heat of d-mannitol were affected by the heating rate. The weight of d-mannitol did not decrease with the increase in temperature between 436 and 455 K. Moreover, numerical simulation was conducted using the commercial CFD code, ANSYS FLUENT. On the basis of the numerical simulation, melting process was affected by natural convection at the inner wall. As the heat flux of the cartridge heater input came from the inner wall, the liquid fraction increased from the inner wall to the outer wall through natural convection. The numerical result was compared with the experimental data. The temperature of the numerical simulation was approximately consistent with the experimental data. Moreover, the local heat transfer coefficients at the heater surface were calculated by the result of the numerical simulation. The heat transfer coefficients decreased during the phase change. It was considered that the heat transfer process changed from conductive heat transfer of solid state to natural convection heat transfer of liquid state as the liquid fraction increased with time.

  2. Solution-processed, molecular photovoltaics that exploit hole transfer from non-fullerene, n-type materials

    KAUST Repository

    Douglas, Jessica D.

    2014-05-12

    Solution-processed organic photovoltaic devices containing p-type and non-fullerene n-type small molecules obtain power conversion efficiencies as high as 2.4%. The optoelectronic properties of the n-type material BT(TTI-n12)2 allow these devices to display high open-circuit voltages (>0.85 V) and generate significant charge carriers through hole transfer in addition to the electron-transfer pathway, which is common in fullerene-based devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Charge transfer bands in optical materials and related defect level location

    Science.gov (United States)

    Dorenbos, Pieter

    2017-07-01

    Charge transfer (CT)-bands, electron trapping, hole trapping, electron release, hole release, metal-to-metal-charge transfer, CT-luminescence, anomalous emission, impurity trapped exciton emission, inter-valence charge transfer, pair-emission, tunneling, photo-electron spectroscopy, redox potentials, photo-ionization, thermal-ionization. All these phenomena deal with the transfer of an electron from one atom in a compound to either another atom in the compound or to the ambient, i.e., outside the compound. The energy needed for, or released in, such transfer carries information on the electron binding energy in the defect levels with respect to the host band levels or the levels in the ambient. First the different types of charge transfer between a lanthanide and the host bands, and how they can be used to construct a host referred binding energy (HRBE) diagram, are reviewed. Then briefly the chemical shift model is introduced in order to convert the HRBE diagram into a vacuum referred binding energy diagram (VRBE). Next charge transfer between transition metal elements and host bands and between Bi3+ and host bands are treated, and finally electron transfer from one defect to another and to the ambient. Illustrating examples are provided.

  4. Energy transfer phenomena and radiative processes in silicon nitride based materials for on-chip photonics applications

    Science.gov (United States)

    Li, Rui

    Rare-earth (RE) doping of silicon-based structures provides a valuable approach for light-emitting devices which could be monolithically integrated atop the widespread silicon electronics platform and enables inexpensive integration of on-chip optical components. However, the small excitable fraction of RE ions and the substantial free carrier losses in Si nanostructures severely limit the possibility to achieve net optical gain using traditional Er doped materials, such as Er doped Si-rich oxides (Er:SRO). On the other hand, a novel material platform based on RE-doped silicon nitride (RE:Six) materials has recently revealed unique advantages for on-chip light source. Based on a variety of light emission spectroscopic techniques and rate equation modeling, light emission and energy transfer phenomena were studied to quantitatively assess the benefits of the novel Er and Nd doped SiNx (Er: SiN x and Nd:SiNx) material platform compared to the standard Er:SRO. Efficient energy transfer and nanosecond-time dynamics from SiN x matrices to RE ions with two orders of magnitude larger coupling coefficient than Er:SRO were demonstrated for the first time. The origin of this energy transfer was shown to consist of non-resonant phonon-mediated coupling by temperature-dependent experiments. In addition, a tradeoff between excitation efficiency by energy transfer and emission efficiency, determined by excess Si concentration, was discovered and studied. Although carrier absorption and non-radiative recombination jeopardize the observation of optical gain, differential loss measurements under femtosecond pulsed excitation resulted in the bleaching of the Er ground state absorption by energy transfer in Er:SiN x materials, which bears great hope for the engineering of Si-based lasers. On the other hand, with a superior 4-level system, Nd:SiNx is promising to lase with a lower threshold. To make use of the better field confinement in SiNx due to its higher refractive index, RE

  5. A transfer-matrix approach for estimating the characteristic impedance and wave numbers of limp and rigid porous materials

    Science.gov (United States)

    Song; Bolton

    2000-03-01

    A method for evaluating the acoustical properties of homogeneous and isotropic porous materials that may be modeled as fluids having complex properties is described here. To implement the procedure, a conventional, two-microphone standing wave tube was modified to include: a new sample holder; a section downstream of the sample holder that accommodated a second pair of microphone holders and an approximately anechoic termination. Sound-pressure measurements at two upstream and two downstream locations were then used to estimate the two-by-two transfer matrix of porous material samples. The experimental transfer matrix method has been most widely used in the past to measure the acoustical properties of silencer system components. That procedure was made more efficient here by taking advantage of the reciprocal nature of sound transmission through homogeneous and isotropic porous layers. The transfer matrix of a homogeneous and isotropic, rigid or limp porous layer can easily be used to identify the material's characteristic impedance and wave number, from which other acoustical quantities of interest can be calculated. The procedure has been used to estimate the acoustical properties of a glass fiber material: good agreement was found between the estimated acoustical properties and those predicted by using the formulas of Delany and Bazley.

  6. Synthesis and energy band characterization of hybrid molecular materials based on organic–polyoxometalate charge-transfer salts

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Chunxia [Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou City, Gansu Province (China); Traditional Chinese Medicine College of Gansu, Gansu (China); Bu, Weifeng, E-mail: buwf@lzu.edu.cn [Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou City, Gansu Province (China)

    2014-11-15

    A cationic amphiphilic molecule was synthesized and employed to encapsulate Lindqvist ([M{sub 6}O{sub 19}]{sup 2−}) and Keggin polyoxometalates ([SiM{sub 12}O{sub 40}]{sup 4−}, M=Mo, W) to form hybrid molecules through electrostatic interaction. The X-ray diffraction results illustrate that the former hybrids possess lamellar nanostructures in their solid states, while the latter hybrids show a cubic Im3m packing model with low intensities and poor long-range order. These hybrids have clear charge-transfer characters as shown in their deeper colors and UV–vis diffuse reflectance spectra. According to the reported reduction potentials of the POM acceptors and the band gaps deduced from their diffuse reflectance spectra, we have calculated the theoretical values of the lowest unoccupied molecular orbital (LUMO) position similar to the electron affinity (E{sub A}) of solid materials. Such energy level parameters are comparable to those of electroluminescence and electron-transport materials commonly used in organic electroluminescence devices. These organic–polyoxometalate charge-transfer salts have more advantages, such as higher decomposition temperatures, easier film fabrication and better electron affinities, which presumably would be used for electron-transport materials in the area of the electroluminescence. - Graphical abstract: Hybrid molecular materials with charge-transfer characters formed by a positively charged donor L and acceptors of the Lindqvist-type and Keggin-type POMs have lamellar and cubic structures in their solid state. - Highlights: • Charge-transfer salts are obtained by self-assembling POMs with an anthracene cation. • Their energy parameters are comparable to those of optoelectronic materials in OLEDs. • These POM-based hybrids could be applied in the area of optoelectronic devices.

  7. Effects of material properties on the competition mechanism of heat transfer of a granular bed in rotary cylinders

    Institute of Scientific and Technical Information of China (English)

    Xie Zhi-Yin; Feng Jun-Xiao

    2013-01-01

    Mixing and heat transfer processes of the granular materials within rotary cylinders play a key role in industrial processes.The numerical simulation is carried out by using the discrete element method (DEM) to investigate the influences of material properties on the bed mixing and heat transfer process,including heat conductivity,heat capacity,and shear modulus.Moreover,a new Péclet number is derived to determine the dominant mechanism of the heating rate within the particle bed,which is directly related to thermal and mechanical properties.The system exhibits a faster heating rate with the increase of ratio of thermal conductivity and heat capacity,or the decrease of shear modulus when inter-particle conduction dominates the heating rate; conversely,it shows a fast-mixing bed when particle convection governs the heating rate.The simulation results show good agreement with the theoretical predictions.

  8. Heat transfer and fluid flow analysis of self-healing in metallic materials

    Science.gov (United States)

    Martínez Lucci, J.; Amano, R. S.; Rohatgi, P. K.

    2017-03-01

    This paper explores imparting self-healing characteristics to metal matrices similar to what are observed in biological systems and are being developed for polymeric materials. To impart self-healing properties to metal matrices, a liquid healing method was investigated; the met hod consists of a container filled with low melting alloy acting as a healing agent, embedded into a high melting metal matrix. When the matrix is cracked; self-healing is achieved by melting the healing agent allowing the liquid metal to flow into the crack. Upon cooling, solidification of the healing agent occurs and seals the crack. The objective of this research is to investigate the fluid flow and heat transfer to impart self-healing property to metal matrices. In this study, a dimensionless healing factor, which may help predict the possibility of healing is proposed. The healing factor is defined as the ratio of the viscous forces and the contact area of liquid metal and solid which prevent flow, and volume expansion, density, and velocity of the liquid metal, gravity, crack size and orientation which promote flow. The factor incorporates the parameters that control self-healing mechanism. It was observed that for lower values of the healing factor, the liquid flows, and for higher values of healing factor, the liquid remains in the container and healing does not occur. To validate and identify the critical range of the healing factor, experiments and simulations were performed for selected combinations of healing agents and metal matrices. The simulations were performed for three-dimensional models and a commercial software 3D Ansys-Fluent was used. Three experimental methods of synthesis of self-healing composites were used. The first method consisted of creating a hole in the matrices, and liquid healing agent was poured into the hole. The second method consisted of micro tubes containing the healing agent, and the third method consisted of incorporating micro balloons containing

  9. Heat transfer and fluid flow analysis of self-healing in metallic materials

    Science.gov (United States)

    Martínez Lucci, J.; Amano, R. S.; Rohatgi, P. K.

    2016-06-01

    This paper explores imparting self-healing characteristics to metal matrices similar to what are observed in biological systems and are being developed for polymeric materials. To impart self-healing properties to metal matrices, a liquid healing method was investigated; the met hod consists of a container filled with low melting alloy acting as a healing agent, embedded into a high melting metal matrix. When the matrix is cracked; self-healing is achieved by melting the healing agent allowing the liquid metal to flow into the crack. Upon cooling, solidification of the healing agent occurs and seals the crack. The objective of this research is to investigate the fluid flow and heat transfer to impart self-healing property to metal matrices. In this study, a dimensionless healing factor, which may help predict the possibility of healing is proposed. The healing factor is defined as the ratio of the viscous forces and the contact area of liquid metal and solid which prevent flow, and volume expansion, density, and velocity of the liquid metal, gravity, crack size and orientation which promote flow. The factor incorporates the parameters that control self-healing mechanism. It was observed that for lower values of the healing factor, the liquid flows, and for higher values of healing factor, the liquid remains in the container and healing does not occur. To validate and identify the critical range of the healing factor, experiments and simulations were performed for selected combinations of healing agents and metal matrices. The simulations were performed for three-dimensional models and a commercial software 3D Ansys-Fluent was used. Three experimental methods of synthesis of self-healing composites were used. The first method consisted of creating a hole in the matrices, and liquid healing agent was poured into the hole. The second method consisted of micro tubes containing the healing agent, and the third method consisted of incorporating micro balloons containing

  10. Fastest non-ionic azo dyes and transfer of their thermal isomerisation kinetics into liquid-crystalline materials.

    Science.gov (United States)

    Garcia-Amorós, Jaume; Castro, M Cidália R; Coelho, Paulo; Raposo, M Manuela M; Velasco, Dolores

    2016-04-14

    Push-pull bithienylpyrrole-based azo dyes exhibit thermal isomerisation rates as fast as 1.4 μs in acetonitrile at 298 K becoming, thus, the fastest neutral azo dyes reported so far. These remarkably low relaxation times can be transferred into liquid-crystalline matrices enabling light-triggered oscillations in the optical density of the final material up to 11 kHz under ambient conditions.

  11. Heat transfer and parametric studies of an encapsulated phase change material based cool thermal energy storage system

    Institute of Scientific and Technical Information of China (English)

    CHERALATHAN M.; VELRAJ R.; RENGANARAYANAN S.

    2006-01-01

    This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES)system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase change material at any axial location during the charging period. The results of the model were validated by comparison with experimental results of temperature profiles of HTF and PCM. The model was also used to investigate the effect of porosity, Stanton number, Stefan number and Peclet number on CTES system performance. The results showed that increase in porosity contributes to a higher rate of energy storage. However, for a given geometry and heat transfer coefficient, the mass of PCM charged in the unit decreases as the increase in porosity. The St number as well as the Ste number is also influential in the performance of the unit. The model is a convenient and more suitable method to determine the heat transfer characteristics of CTES system. The results reported are much useful for designing CTES system.

  12. Academic Entrepreneurship and Exchange of Scientific Resources: Material Transfer in Life and Materials Sciences in Japanese Universities

    Science.gov (United States)

    Shibayama, Sotaro; Walsh, John P.; Baba, Yasunori

    2012-01-01

    This study uses a sample of Japanese university scientists in life and materials sciences to examine how academic entrepreneurship has affected the norms and behaviors of academic scientists regarding sharing scientific resources. Results indicate that high levels of academic entrepreneurship in a scientific field are associated with less reliance…

  13. Natural convection heat transfer coefficients in phase change material (PCM) modules with external vertical fins

    Energy Technology Data Exchange (ETDEWEB)

    Castell, Albert; Sole, Cristian; Medrano, Marc; Roca, Joan; Cabeza, Luisa F. [Departament d' Informatica i Enginyeria Industrial, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain); Garcia, Daniel [Departament Projectes d' Enginyeria, Universitat Politecnica de Catalunya, Colom 11, 08222 Terrassa (Spain)

    2008-09-15

    To determine the heat transfer coefficient by natural convection for specific geometries, experimental correlations are used. No correlations were found in the literature for the geometries studied in this work. These geometries consisted of a cylindrical module of 88 mm of diameter and 315 mm height with external vertical fins of 310 mm height and 20 and 40 mm length. To determine the heat transfer coefficient by natural convection, experimental work was done. This module, containing PCM (sodium acetate trihydrate), was situated in the middle upper part of a cylindrical water tank of 440 mm of diameter and 450 mm height. The calculated heat transfer coefficient changed by using external fins, as the heat transfer surface was increased. The temperature variation of the PCM and the water are presented as a function of time, and the heat transfer coefficient for different fins is presented as a function of the temperature difference. Experimental correlations were obtained, presenting the Nusselt number as a function of different dimensionless numbers. Different correlations were analysed to find which one fit better to the experimental data. (author)

  14. The transfer of diatoms from freshwater to footwear materials: An experimental study assessing transfer, persistence, and extraction methods for forensic reconstruction.

    Science.gov (United States)

    Levin, E A; Morgan, R M; Scott, K R; Jones, V J

    2017-09-01

    In recent years there has been growing interest in environmental forms of trace evidence, and ecological trace evidence collected from footwear has proved valuable within casework. Simultaneously, there has been growing awareness of the need for empirical experimentation to underpin forensic inferences. Diatoms are unicellular algae, and each cell (or 'frustule') consists of two valves which are made of silica, a robust material that favours their preservation both in sediments and within forensic scenarios. A series of experiments were carried out to investigate the transfer and persistence of diatoms upon common footwear materials, a recipient surface that has historically been overlooked by studies of persistence. The effectiveness of two novel extraction techniques (jet rinsing, and heating and agitation with distilled water) was compared to the established extraction technique of hydrogen peroxide digestion, for a suite of five common footwear materials: canvas, leather, and 'suede' (representing upper materials), and rubber and polyurethane (representing sole materials). It was observed that the novel extraction technique of heating and agitation with distilled water did not extract fewer diatom valves, or cause increased fragmentation of valves, when compared to peroxide digestion, suggesting that the method may be viable where potentially hazardous chemical reactions may be encountered with the peroxide digestion method. Valves could be extracted from all five footwear materials after 3min of immersion, and more valves were extracted from the rougher, woven upper materials than the smoother sole materials. Canvas yielded the most valves (a mean of 2511/cm(2)) and polyurethane the fewest (a mean of 15/cm(2)). The persistence of diatoms on the three upper materials was addressed with a preliminary pilot investigation, with ten intervals sampled between 0 and 168h. Valves were seen to persist in detectable quantities after 168h on all three upper materials

  15. Mass transfer across combustion gas thermal boundary layers - Power production and materials processing implications

    Science.gov (United States)

    Rosner, D. E.

    1985-01-01

    The effects of Soret diffusion (for vapors) and thermophoresis (for particles) are illustrated using recent optical experiments and boundary layer computations. Mass transfer rate augmentations of up to a factor of 1000 were observed and predicted for submicron-particle capture by cooled solid surfaces, while mass transfer suppressions of more than 10 to the -10th-fold were predicted for 'overheated' surfaces. It is noted that the results obtained are of interest in connection with such technological applications as fly-ash capture in power generation equipment and glass droplet deposition in optical-waveguide manufacture.

  16. Effect of thermal conductivity of tube material on overall heat transfer coefficient of condenser, proposal for correction of HEI code

    Energy Technology Data Exchange (ETDEWEB)

    Banquet, F. [Electricite de France, Villeurbanne (France)

    1996-08-01

    The HEI code, 8th edition, addendum n{degrees}1, which was used for condenser design, makes no distinction between grade 2 titanium characteristics and those of 304L and 316L stainless steels. In 1993 the Electric Power Research Institute (EPRI) published the results of a study on a test condenser: these suggest that the overall heat transfer coefficient of a titanium bundle is substantially higher than that of the same bundle made from stainless steel. The EPRI study inspired the 9th edition of the HEI Standards. To form its own opinion, EDF conducted a study to compare these various design methods and, in particular, to evaluate the effect of the thermal conductivity of materials on the overall heat transfer coefficient; a two-dimensional thermohydraulic code was used, considering different condensers from EDF nuclear power plants. During the study EDF observed that the thermal conductivity values of materials varied greatly depending on the sources, mainly grade 2 titanium and, to a lesser extent, 304L and 316L. It had the thermal conductivity of these materials measured using a highly accurate method in a manufacturer-independent laboratory. In conclusion, EDF considers: The EPRI correction method is wholly acceptable, The HEI 9 code is acceptable on condition that the material correction factors are slightly modified. 5 refs., 11 tabs.

  17. Transfer of genetic material between pathogenic and food-borne yeasts

    DEFF Research Database (Denmark)

    Mentel, M.; Spirek, M.; Jorck-Ramberg, D.

    2006-01-01

    Many pathogenic yeast species are asexual and therefore not involved in intra- or interspecies mating. However, high-frequency transfer of plasmid DNA was observed when pathogenic and food-borne yeasts were grown together. This property could play a crucial role in the spread of virulence and drug...

  18. Wheeled Vehicle Clutches, Transmissions, and Transfers. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle clutches, transmissions, and transfer cases. It provides the basic…

  19. Conjugate Heat Transfer and Thermal Mechanical Analysis for the Fast Spectrum Neutron Source for Materials Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Olivas, Eric Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-04

    A conjugate heat transfer and thermal structural analysis was completed, with the objective of determining the following: Lead bismuth eutectic (LBE) peak temperature, free convective velocity patterns in the LBE, peak beam window temperature, and thermal stress/deformation in the window.

  20. Transfer of genetic material between pathogenic and food-borne yeasts

    DEFF Research Database (Denmark)

    Mentel, M.; Spirek, M.; Jorck-Ramberg, D.

    2006-01-01

    Many pathogenic yeast species are asexual and therefore not involved in intra- or interspecies mating. However, high-frequency transfer of plasmid DNA was observed when pathogenic and food-borne yeasts were grown together. This property could play a crucial role in the spread of virulence and drug...... resistance factors among yeasts....

  1. Gentle transfer method for water- and acid/alkali-sensitive 2D materials for (S)TEM study

    Science.gov (United States)

    Lin, Junhao; Lin, Yung-Chang; Wang, Xinsheng; Xie, Liming; Suenaga, Kazutomo

    2016-11-01

    We report a method in making transmission electron microscopy sample for both CVD-grown and exfoliated 2D materials without etching process, thus gentle to those 2D materials that are sensitive to water and reactive etchants. Large-scale WS2 monolayer grown on glass, NbS2 atomic layers grown on exfoliated h-BN flakes, and water-sensitive exfoliated TiS2 flakes are given as representative examples. We show that the as-transferred samples not only retain excellent structural integrity down to atomic scale but also have little oxidations, presumably due to the minimum contact with water/etchants. This method paves the way for atomic scale structural and chemical investigations in sensitive 2D materials.

  2. Low cost transportable device for transference of atmosphere sensitive materials from glove box to SEM

    DEFF Research Database (Denmark)

    Bentzen, Janet Jonna; Saxild, Finn B.

    Moisture or air sensitive materials are often encountered within several highly important fields such as catalyst R&D, pharmaceutical R&D, and battery R&D. Essential to all materials research and development is microstructure characterization, which often implies electron microscopy. Entering the...

  3. Merton and Ziman's modes of science: the case of biological and similar material transfer agreements

    NARCIS (Netherlands)

    Rodriguez, Victor

    2007-01-01

    This paper makes a connection between recent studies on research materials exchange and its effect on the progress of science. Academia fears that scientific development could be hampered by the privatised practices of research material exchange. Since post-academic science represents a sufficient d

  4. Generalized thermoelastic interaction in functional graded material with fractional order three-phase lag heat transfer

    Institute of Scientific and Technical Information of China (English)

    Ibrahim A. Abbas

    2015-01-01

    The present work is concerned with the solution of a problem on thermoelastic interactions in a functional graded material due to thermal shock in the context of the fractional order three-phase lag model. The governing equations of fractional order generalized thermoelasticity with three-phase lag model for functionally graded materials (FGM) (i.e., material with spatially varying material properties) are established. The analytical solution in the transform domain is obtained by using the eigenvalue approach. The inversion of Laplace transform is done numerically. The graphical results indicate that the fractional parameter has significant effects on all the physical quantities. Thus, we can consider the theory of fractional order generalized thermoelasticity an improvement on studying elastic materials.

  5. Effect of Borehole Material on Analytical Solutions of the Heat Transfer Model of Ground Heat Exchangers Considering Groundwater Flow

    Directory of Open Access Journals (Sweden)

    Sangwoo Park

    2016-04-01

    Full Text Available Groundwater flow is one of the most important factors for the design of a ground heat exchanger (GHEX since the thermal environment of the ground around the buried GHEX is significantly affected by heat convection due to the groundwater flow. Several preceding studies have been conducted to develop analytical solutions to the heat transfer model of GHEX with consideration of groundwater flow. One of these solutions is the combined heat transfer model of conduction and convection. However, the developed combined analytical models are inapplicable to all of the configurations of ordinary GHEXs because these solutions assume that the inner part of the borehole is thermally inert or consists of the same material as that of the surrounding ground. In this paper, the applicability of the combined solid cylindrical heat source model, which is the most suitable to energy piles until now, was evaluated by performing a series of numerical analyses. In the numerical analysis, the inner part of the borehole was modeled as two different materials (i.e., permeable ground formation and impermeable fill such as concrete to evaluate applicability of the analytical solution along with different diameter-length (D/L ratios of borehole. In a small value of the D/L ratio, the analytical solution to the combined heat transfer model is in good agreement with the result of numerical analysis. On the other hand, when increasing the D/L ratio, the analytical solution significantly overestimates the effect of groundwater flow on the heat transfer of GHEXs because the analytical solution disregards the existence of the impermeable region in the borehole. Consequently, such tendency is more critical in the GHEX with a large D/L ratio such as large-diameter energy piles.

  6. A one-dimensional material transfer model for HECTR version 1. 5

    Energy Technology Data Exchange (ETDEWEB)

    Geller, A.S.; Wong, C.C.

    1991-08-01

    HECTR (Hydrogen Event Containment Transient Response) is a lumped-parameter computer code developed for calculating the pressure-temperature response to combustion in a nuclear power plant containment building. The code uses a control-volume approach and subscale models to simulate the mass, momentum, and energy transfer occurring in the containment during a loss-of-collant-accident (LOCA). This document describes one-dimensional subscale models for mass and momentum transfer, and the modifications to the code required to implement them. Two problems were analyzed: the first corresponding to a standard problem studied with previous HECTR versions, the second to experiments. The performance of the revised code relative to previous HECTR version is discussed as is the ability of the code to model the experiments. 8 refs., 5 figs., 3 tabs.

  7. Empirical Validation of Heat Transfer Performance Simulation of Graphite/PCM Concrete Materials for Thermally Activated Building System

    Directory of Open Access Journals (Sweden)

    Jin-Hee Song

    2017-01-01

    Full Text Available To increase the heat capacity in lightweight construction materials, a phase change material (PCM can be introduced to building elements. A thermally activated building system (TABS with graphite/PCM concrete hollow core slab is suggested as an energy-efficient technology to shift and reduce the peak thermal load in buildings. An evaluation of heat storage and dissipation characteristics of TABS in graphite/PCM concrete has been conducted using dynamic simulations, but empirical validation is necessary to acceptably predict the thermal behavior of graphite/PCM concrete. This study aimed to validate the thermal behavior of graphite/PCM concrete through a three-dimensional transient heat transfer simulation. The simulation results were compared to experimental results from previous studies of concrete and graphite/PCM concrete. The overall thermal behavior for both materials was found to be similar to experiment results. Limitations in the simulation modeling, which included determination of the indoor heat transfer coefficient, assumption of constant thermal conductivity with temperature, and assumption of specimen homogeneity, led to slight differences between the measured and simulated results.

  8. Scaling Laws and Mesoscopic Modeling of Heat Transfer in Nanofibrous Materials and Composites

    Science.gov (United States)

    2013-11-26

    buckypaper, and other materials composed of carbon nanotubes (CNTs), individual CNTs are bound together by van der Waals forces and form entangled...for nanofibrous materials based on carbon nanotubes (CNTs) are investigated by performing a multiscale computational study combining atomistic...composition on the ejection and transport of polymer molecules and carbon nanotubes in matrix-assisted pulsed laser evaporation, Appl. Phys. A 105, 529

  9. Numerical simulation on heat transfer performance of vertical U-tube with different borehole fill materials

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Heat exchange performance of vertical U-tube heat exchanger was studiedwith two different borehole fill materials and CFD software. Borehole surface temperature and water temperature distribution were simulated on the condition of continuous operation for 8 h in winter with inlet water temperature being 10 ℃. The results show that there is no obvious difference on heat exchanger performance between the two different borehole fill materials.

  10. In vitro study of reduction of stress transferred onto tissues around implants using a resilient material in maxillary implant overdentures.

    Science.gov (United States)

    Kanazawa, Manabu; Minakuchi, Shunsuke; Hayakawa, Iwao; Hirano, Shigezo; Uchida, Tatsuro

    2007-03-01

    The purpose of this in vitro study was to investigate the effect of hardness on the reduction of stress transferred to tissues around implants using a resilient material applied to the female parts of the ball attachment in maxillary implant overdentures. A cast chrome-cobalt framework was mounted onto a maxillary acrylic edentulous model, which contained two implants and four strain gauges attached to the implant. Ball abutments were screwed into the implant. One abutment was connected to a dedicated metal cap embedded in the housing, while the others were connected to resilient test materials with four different hardnesses. Loads were applied using a universal testing machine with a magnitude of 50 N. The sums of the absolute values recorded from the four strain gauges were used for stress evaluation. The measured strains were analyzed statistically using two-way ANOVA and multiple comparisons. A resilient material with hardness 90 exhibited strains that did not differ significantly from the control. In contrast, the other resilient materials showed significantly reduced strains under all conditions. In this limited study, application of resilient silicone materials with approximate hardness 80 to the female parts of ball attachments significantly reduced the stress on the tissues around the implant.

  11. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    Science.gov (United States)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  12. Spectral emissivity measurements of land-surface materials and related radiative transfer simulations

    Science.gov (United States)

    Wan, Z.; Ng, D.; Dozier, J.

    1994-01-01

    Spectral radiance measurements have been made in the laboratory and in the field for deriving spectral emissivities of some land cover samples with a spectroradiometer and an auxiliary radiation source in the wavelength range 2.5-14.5 micrometers. A easy and quick four-step method (four steps to measure the sample and a diffuse reflecting plate surface under sunshine and shadowing conditions, respectively) has been used for simultaneous determination of surface temperature and emissivity. We emphasized in-situ measurements in combination with radiative transfer simulations, and an error analysis for basic assumptions in deriving spectral emissivity of land-surface samples from thermal infrared measurements.

  13. Materials for Fluorescence Resonance Energy Transfer Analysis: Beyond Traditional Donor-Acceptor Combinations

    Science.gov (United States)

    2006-01-01

    Received: November 2, 2005 [1] “10th Spiers Memorial Lecture. Transfer mechanisms of elec- tronic excitation”: T. F.rster, Discuss. Faraday Soc. 1959, 27...GmbH & Co. KGaA, Weinheim www.angewandte.org [98] S. A. Kushon, K. D. Ley , K. Bradford, R. M. Jones, D. McBranch, D. Whitten, Langmuir 2002, 18, 7245...Bergstedt, X. B. Shi, F. Rininsland, S. A. Kushon, W. S. Xia, K. D. Ley , K. Achyuthan, D. McBranch, Proc. Natl. Acad. Sci. USA 2004, 101, 7511. [101] S. W

  14. Flow and Heat Transfer in Micro Pin Fin Heat Sinks with Nano-Encapsulated Phase Change Materials

    CERN Document Server

    Rajabifar, Bahram; Zhang, Yuwen; Khanna, Sanjeev K

    2016-01-01

    In this paper, a 3D conjugated heat transfer model for Nano-Encapsulated Phase Change Materials (NEPCMs) cooled Micro Pin Fin Heat Sink (MPFHS) is presented. The governing equations of flow and heat transfer are solved using a finite volume method based on collocated grid and the results are validated with the available data reported in the literature. The effect of nanoparticles volume fraction (C = 0.1, 0.2, 0.3), inlet velocity (Vin = 0.015, 0.030, 0.045 m/s), and bottom wall temperature (Twall = 299.15, 303.15, 315.15, 350.15 K) are studied on Nusselt and Euler numbers as well as temperature contours in the system. The results indicate that significant heat transfer enhancement is achieved when using NEPCM slurry as an advanced coolant. The maximum Nusselt number when NEPCM slurry (C = 0.3) with Vin = 0.015, 0.030, 0.045 (m/s) is employed, are 2.27, 1.81, 1.56 times higher than the ones with base fluid, respectively. However, with increasing bottom wall temperature, the Nusselt number first increases then...

  15. Control of intrachain charge transfer in model systems for block copolymer photovoltaic materials.

    Science.gov (United States)

    Johnson, Kerr; Huang, Ya-Shih; Huettner, Sven; Sommer, Michael; Brinkmann, Martin; Mulherin, Rhiannon; Niedzialek, Dorota; Beljonne, David; Clark, Jenny; Huck, Wilhelm T S; Friend, Richard H

    2013-04-01

    We report the electronic properties of the conjugated coupling between a donor polymer and an acceptor segment serving as a model for the coupling in conjugated donor-acceptor block copolymers. These structures allow the study of possible intrachain photoinduced charge separation, in contrast to the interchain separation achieved in conventional donor-acceptor blends. Depending on the nature of the conjugated linkage, we observe varying degrees of modification of the excited states, including the formation of intrachain charge transfer excitons. The polymers comprise a block (typically 18 repeat units) of P3HT, poly(3-hexyl thiophene), coupled to a single unit of F8-TBT (where F8 is dioctylfluorene, and TBT is thiophene-benzothiadiazole-thiophene). When the P3HT chain is linked to the TBT unit, we observe formation of a localized charge transfer state, with red-shifted absorption and emission. Independent of the excitation energy, this state is formed very rapidly (<40 fs) and efficiently. Because there is only a single TBT unit present, there is little scope for long-range charge separation and it is relatively short-lived, <1 ns. In contrast, when the P3HT chain and TBT unit are separated by the wider bandgap F8 unit, there is little indication for modification of either ground or excited electronic states, and longer-lived charge separated states are observed.

  16. Molten Salt Heat Transport Loop: Materials Corrosion and Heat Transfer Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Kumar Sridharan; Dr. Mark Anderson; Dr. Michael Corradini; Dr. Todd Allen; Luke Olson; James Ambrosek; Daniel Ludwig

    2008-07-09

    An experimental system for corrosion testing of candidate materials in molten FLiNaK salt at 850 degree C has been designed and constructed. While molten FLiNaK salt was the focus of this study, the system can be utilized for evaluation of materials in other molten salts that may be of interest in the future. Using this system, the corrosion performance of a number of code-certified alloys of interest to NGNP as well as the efficacy of Ni-electroplating have been investigated. The mechanisums underlying corrosion processes have been elucidated using scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy of the materials after the corrosion tests, as well as by the post-corrosion analysis of the salts using inductively coupled plasma (ICP) and neutron activation analysis (NAA) techniques.

  17. XCHEM-1D: A Heat Transfer/Chemical Kinetics Computer Program for multilayered reactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Gross, R.J.; Baer, M.R.; Hobbs, M.L.

    1993-10-01

    An eXplosive CHEMical kinetics code, XCHEM, has been developed to solve the reactive diffusion equations associated with thermal ignition of energetic materials. This method-of-lines code uses stiff numerical methods and adaptive meshing to resolve relevant combustion physics. Solution accuracy is maintained between multilayered materials consisting of blends of reactive components and/or inert materials. Phase change and variable properties are included in one-dimensional slab, cylindrical and spherical geometries. Temperature-dependent thermal properties have been incorporated and the modification of thermal conductivities to include decomposition effects are estimated using solid/gas volume fractions determined by species fractions. Gas transport properties, including high pressure corrections, have also been included. Time varying temperature, heat flux, convective and thermal radiation boundary conditions, and layer to layer contact resistances have also been implemented.

  18. A novel method for measuring the diffusion, partition and convective mass transfer coefficients of formaldehyde and VOC in building materials.

    Directory of Open Access Journals (Sweden)

    Jianyin Xiong

    Full Text Available The diffusion coefficient (D(m and material/air partition coefficient (K are two key parameters characterizing the formaldehyde and volatile organic compounds (VOC sorption behavior in building materials. By virtue of the sorption process in airtight chamber, this paper proposes a novel method to measure the two key parameters, as well as the convective mass transfer coefficient (h(m. Compared to traditional methods, it has the following merits: (1 the K, D(m and h(m can be simultaneously obtained, thus is convenient to use; (2 it is time-saving, just one sorption process in airtight chamber is required; (3 the determination of h(m is based on the formaldehyde and VOC concentration data in the test chamber rather than the generally used empirical correlations obtained from the heat and mass transfer analogy, thus is more accurate and can be regarded as a significant improvement. The present method is applied to measure the three parameters by treating the experimental data in the literature, and good results are obtained, which validates the effectiveness of the method. Our new method also provides a potential pathway for measuring h(m of semi-volatile organic compounds (SVOC by using that of VOC.

  19. Effect of Mold Coating Materials and Thickness on Heat Transfer in Permanent Mold Casting of Aluminum Alloys

    Science.gov (United States)

    Hamasaiid, A.; Dargusch, M. S.; Davidson, C. J.; Tovar, S.; Loulou, T.; Rezaï-Aria, F.; Dour, G.

    2007-06-01

    In permanent mold casting or gravity die casting (GDC) of aluminum alloys, die coating at the casting-mold interface is the most important single factor controlling heat transfer and, hence, it has the greatest influence on the solidification rate and development of microstructure. This investigation studies the influence of coating thickness, coating composition, and alloy composition on the heat transfer at the casting-mold interface. Both graphite and TiO2-based coatings have been investigated. Two aluminum alloys have been investigated: Al-7Si-0.3Mg and Al-9Si-3Cu. Thermal histories throughout the die wall have been recorded by fine type-K thermocouples. From these measurements, die surface temperatures and heat flux density have been evaluated using an inverse method. Casting surface temperature was measured by infrared pyrometry, and the interfacial heat-transfer coefficient (HTC) has been determined using these combined pieces of information. While the alloy is liquid, the coating material has only a weak influence over heat flow and the thermal contact resistance seems to be governed more by coating porosity and thickness. The HTC decreases as the coating thickness increases. However, as solidification takes place and the HTC decreases, the HTC of graphite coating remains higher than that of ceramic coatings of similar thickness. After the formation of an air gap at the interface, the effect of coating material vanishes. The peak values of HTC and the heat flux density are larger for Al-7Si-0.3Mg than for Al-9Si-3Cu. Consequently, the apparent solidification time of Al-9Si-3Cu is larger than that of Al-7Si-0.3Mg and it increases with coating thickness.

  20. Does the Transfer of Forest Reproductive Material Significantly Affect Local Tree Diversity?

    NARCIS (Netherlands)

    Kramer, K.; Geburek, Thomas; Jansen, Simon

    2016-01-01

    Genetic variation within tree species is an important component
    of forest biodiversity. It enables forest ecosystems to adapt to
    environmental changes and it provides genetic material for
    breeding to sustainably increase production. In the framework of
    forestry activities, tree

  1. Near Field Heat Transfer between Random Composite Materials: Applications and Limitations

    Science.gov (United States)

    Santiago, Eva Yazmin; Esquivel-Sirvent, Raul

    2017-02-01

    We present a theoretical study of the limits and bounds of using effective medium approximations in the calculation of the near field radiative heat transfer between a composite system made of Au nanoparticles in a SiC host and an homogeneous SiC slab. The effective dielectric function of the composite slab is calculated using three different approximations: Maxwell-Garnett, Bruggeman, and Looyenga's. In addition, we considered an empirical fit to the effective dielectric function by Grundquist and Hunderi. We show that the calculated value of the heat flux in the near field is dependent on the model, and the difference in the effective dielectric function is larger around the plasmonic response of the Au nanoparticles. This, in turn, accounts for the difference in the near field radiative heat flux. For all values of filling fractions, the Looyenga approximation gives a lower bound for the heat flux.

  2. Near field heat transfer between random composite materials. Applications and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, Eva Yazmin; Esquivel-Sirvent, Raul [Univ. Nacional Autonoma de Mexico (Mexico). Inst. de Fisica

    2017-05-01

    We present a theoretical study of the limits and bounds of using effective medium approximations in the calculation of the near field radiative heat transfer between a composite system made of Au nanoparticles in a SiC host and an homogeneous SiC slab. The effective dielectric function of the composite slab is calculated using three different approximations: Maxwell-Garnett, Bruggeman, and Looyenga's. In addition, we considered an empirical fit to the effective dielectric function by Grundquist and Hunderi. We show that the calculated value of the heat flux in the near field is dependent on the model, and the difference in the effective dielectric function is larger around the plasmonic response of the Au nanoparticles. This, in turn, accounts for the difference in the near field radiative heat flux. For all values of filling fractions, the Looyenga approximation gives a lower bound for the heat flux.

  3. Experimental study of plasma energy transfer and material erosion under ELM-like heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E., E-mail: garkusha@ipp.kharkov.u [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Makhlaj, V.A.; Chebotarev, V.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Landman, I. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Tereshin, V.I.; Aksenov, N.N.; Bandura, A.N. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)

    2009-06-15

    Main features of plasma-surface interaction and energy transfer to tokamak plasma facing components are studied at different heat loads in ELM simulation experiments with the plasma gun QSPA Kh-50. Repetitive plasma exposures of tungsten, graphite and different combined W-C targets were performed at the pulse duration of 0.25 ms and the heat loads varied in the range 0.2-2.5 MJ/m{sup 2}. The onset of vapor shield in front of the surface was investigated. The evaporation is immediately followed by a saturation of surface heat load if further increasing the impact energy. The presence of graphite essentially decreases the heat flux to the nearby tungsten surface, which is due to the carbon vapor shield. Droplet splashing at the tungsten surface and formation of hot spots on the graphite surface are discussed.

  4. Optics and materials research for controlled radiant energy transfer in energy efficient buildings

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Haas, T.E.

    1990-01-01

    During the past year important progress has been made in regard to uncovering and solving several key problems with respect to developing a lithium-based, monolithic, completely inorganic, reflectivity-modulating, robust electronic window to the point where its technology transfer can be smoothly accomplished. The major problems remaining to be solved are: (a) develop a counterelectrode layer which, as part of the multilayer window structure, is optically and electrochemically satisfactory; (b) develop an optically transparent lithium ion/water vapor blocking layer to prevent the irreversible loss of lithium; (c) develop an optically transparent capping layer; and (d) develop a recipe(s) necessary to obtain robust prototype electrochromic windows by a production-worthy process, such as reactive magnetron sputtering. 1 tab.

  5. Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces.

    Science.gov (United States)

    Rückerl, Florian; Waas, Daniel; Büchner, Bernd; Knupfer, Martin; Zahn, Dietrich R T; Haidu, Francisc; Hahn, Torsten; Kortus, Jens

    2017-01-01

    Manganese phthalocyanine (MnPc) is a member of the family of transition-metal phthalocyanines, which combines interesting electronic behavior in the fields of organic and molecular electronics with local magnetic moments. MnPc is characterized by hybrid states between the Mn 3d orbitals and the π orbitals of the ligand very close to the Fermi level. This causes particular physical properties, different from those of the other phthalocyanines, such as a rather small ionization potential, a small band gap and a large electron affinity. These can be exploited to prepare particular compounds and interfaces with appropriate partners, which are characterized by a charge transfer from or to MnPc. We summarize recent spectroscopic and theoretical results that have been achieved in this regard.

  6. Effect of transverse vibrations of fissile nuclei on the angular and spin distributions of low-energy fission fragments

    Science.gov (United States)

    Bunakov, V. E.; Kadmensky, S. G.; Lyubashevsky, D. E.

    2016-05-01

    It is shown that A. Bohr's classic theory of angular distributions of fragments originating from low-energy fission should be supplemented with quantum corrections based on the involvement of a superposition of a very large number of angular momenta L m in the description of the relative motion of fragments flying apart along the straight line coincidentwith the symmetry axis. It is revealed that quantum zero-point wriggling-type vibrations of the fissile system in the vicinity of its scission point are a source of these angular momenta and of high fragment spins observed experimentally.

  7. Heat Transfer Modeling of Phase Change Materials in Multiple Plates Heat Exchanger

    Directory of Open Access Journals (Sweden)

    M. Alipanah

    2013-12-01

    Full Text Available Nowadays, given the increasing importance of energy sources, the possibility of energy storage in the heat exchangers through the Phase Change Materials (PCM and releasing it when needed have been extremely essential. This study seeks to model the domestic water heat system in which the paraffin is as the phase change material and it stores the solar energy. The behavior of a PCM plate was studied by writing the governing equations and solving them as the one-dimensional, implicit method and through numerical calculation of the method equations. Given the confirmed accuracy of performed modeling by the results of similar studies for the complete melting and solidification of PCM, the application of this system seems appropriate for the solar domestic water heaters.

  8. 1-D Heat Transfer in Multilayer Materials Using a Finite Volume Approach

    Science.gov (United States)

    2014-01-01

    that the material density and specific heat do not change over the time interval being evaluated. The net energy rates due to conduction , convection , and...heat fluxes due to conduction , convection , and radiation, other thermodynamic phenomena (e.g. ablation heating or cooling) could be incorporated into...of the cell interfaces. The present work considered heat fluxes due to conduction , convection , and radiation, but other heat fluxes (e.g., due to

  9. Technology Transfer Opportunities for the Construction Engineering Community: Materials and Diagnostics.

    Science.gov (United States)

    1986-02-27

    34 .. CC .0 clj 0 C.C. -" C 4)4) 0 C.27 ROOF BLISTER VALVE Charles Korhonen U.S. Army Cold Regions Research and Engineering Laboratory Annually, the Army...7122 (within Illinois). REFERENCES 1. A. Kumar, E. C. Segan, and J. Bukowski , "Ceramic Coated Anodes for Cathodic Protection," Materials Performance...Chief of Engineers. References: (Available from the author) 1. "Roof Moisture Surveys: Yesterday, Today and Tomorrow," by Wayne Tobiasson and Charles

  10. Full control of heat transfer in single-particle structural materials

    Science.gov (United States)

    Yang, S.; Xu, L. J.; Wang, R. Z.; Huang, J. P.

    2017-09-01

    Thermal metamaterials have been applied to implement thermal phenomena, such as invisibility, illusion, and refraction. However, during the fabrication, they probably have complicated issues which are on account of the complicated structures. To get around this, here we put forward a single-particle structure. The theory helps to simplify the existing methods, which will undoubtedly contribute to the efficiency of fabrication. For clarity, we show the simulation and experimental results of thermal invisibility and illusion based on our proposed single-particle structural materials. Moreover, by tailoring the shape factor of the single particle appropriately, we can simultaneously realize thermal invisibility and illusion with only one device. The adjustable area fraction also indicates that these types of structural materials are highly adaptable. Such a single-particle device may have broad applications in misleading infrared detection. This work not only opens an avenue to design thermal materials based on single-particle structures but also holds for other physical fields like electrostatics, magnetostatics, and particle dynamics.

  11. Electron and proton transfer assemblies and new porous materials from nanometer-scale building blocks

    Science.gov (United States)

    Johnson, Stacy Ann

    Elegant examples of molecular engineering are found in nature that make our current small devices seem primitive. By using naturally occurring examples we can better imagine how to construct useful three dimensional nanoscaled devices. Electron and proton transfer composites were prepared using a multilayer film growth technique, in which single anionic sheets derived from inorganic solids are interleaved with cationic polyelectrolytes. This method allows for the growth of concentric monolayers of redox-active polymers on high-surface-area silica supports, and for vectorial electron transfer reactions through the layers of the "onion." Photoinduced charge separation has been observed in composites consisting of an inner polycationic layer of poly(styrene- co-N-vinylbenzyl-N'-methyl-4,4 '-bipyridine), and an outer polycationic layer of poly[Ru(bpy) 2(vbpy)]2+, vbpy = 4-vinyl-4'-methyl- 2,2'-bipyridine, bpy = 2,2' -bipyridine, which are separated by a thin inorganic sheet of Zr(HOPO 3)2·H2O. Following the logic of the proton transport mechanism found in biological membranes, a photosensitive proton pump was constructed using the same electrostatic adsorption technique. This composite was prepared with a polymeric form of a luminescent ruthenium complex, poly[Ru(bpy) 2(bpm)]2+, bpy = 2,2'-bipyridine bpm = 2,2'-bipyrimidine. The pH of a solution in which the composites were suspended changed reversibly when irradiated with visible light. A series of microporous polymer replicas were synthesized using inorganic templates. Zeolites were used as templates to prepare microporous polymer replicas with nanometer sized pore networks. Phenol-formaldehyde polymers were synthesized and cured within the channel networks of zeolites Y, beta, and L. Dissolution of the aluminosilicate framework in aqueous IHF yields an organic replica. The zeolite template exerts important topological effects on the structure and physical properties of the replica. A similar process is described

  12. Titanium-oxo cluster with 9-anthracenecarboxylate antennae: a fluorescent and photocurrent transfer material.

    Science.gov (United States)

    Wu, Yin-Yin; Lu, Xiao-Wen; Qi, Miao; Su, Hu-Chao; Zhao, Xiao-Wei; Zhu, Qin-Yu; Dai, Jie

    2014-07-21

    Attention has been paid to titanium-oxo clusters (TOCs) modified with functional molecules, because they can be considered as model systems for dye-sensitized titanium oxides in terms of their information in structures and electron transfer. We select 9-anthracenecarboxylate (9-AC) as a photoactive ligand and prepare two model compounds, [Ti6O6(O(i)Pr)6(9-AC)6] (1) and [Ti6O4(O(i)Pr)6(cat)4(9-AC)2] (2) (where cat = catecholate). Structures of the TOCs and the dye-TOC linkage are characterized by single-crystal analysis. Solvent-induced fluorescence change is observed for the cluster solution, and the fluorescence can be turned off by irradiating and on by oxygen bubbling. Photoinduced Ti(III) is responsible for the fluorescence extinction. The photocurrent conversion property of the clusters is examined by use of a three-electrode cell with cluster-coated indium tin oxide (ITO) electrodes. The results indicate that 9-AC is an effective photosensitizer and cluster 1 shows higher photocurrent intensity for its multiantenna structure in comparison with that of 2. Density of states for cluster 1 is calculated, in which the discrete energy bands of Ti6O24 include a number of new energy levels for the contribution of 9-AC molecules.

  13. Oxygen transfer materials with catalytic properties for biomass gasification[Dissertation 17302

    Energy Technology Data Exchange (ETDEWEB)

    Pecho, J.

    2007-06-15

    By application of olivine as bed material in a biomass gasifier such as the FICFB type (Fast Internal Circulating Fluidized Bed) in Guessing, Austria, an improvement of the gasification process was observed. Reduction of tars was measured and oxygen increase in the process was calculated. However, it took a while before these properties became clear. Aim of the project was to elucidate the mechanism with which olivine influences the system and to find a new material with improved properties for the gasification process. There were some factors which had be taken into account, e.g., amount of free lattice oxygen, reaction enthalpy, selectivity, mechanical and chemical stability, costs, desulphurization and decarbonisation. Several studies have shown that natural olivine ((Fe{sub x}Mg{sub 1-x}){sub 2}SiO{sub 4}) lowers tar formation in fluidized bed gasification of biomass. According to most authors, the phenomenon is related to the presence of iron oxide (Fe{sub 2}O{sub 3}) which is, e.g., formed during the calcination of olivine in air. To elucidate the role of the iron oxide, synthetic olivine with a molar ratio of Fe:Mg equal to unity has been exposed to gases that contained either wet methane or wet toluene as the only carbon source in a thermobalance interfaced to on-line gas analysis. The results provide strong evidence that the conversion of the carbon species is dominated by the stoichiometric reaction of binary iron oxide with hydrocarbons in the beginning of the reaction while catalytic reactions such as steam reforming contribute little to the observed tar reduction. This reaction path straightforwardly explains the influence of the olivine's origin or the pre-treatment on its chemical reactivity as it was reported by the various authors. To improve the catalytic properties and oxygen capacity of bed materials, we put our focus on perovskite type oxides La{sub x}Sr{sub 1-x}Cr{sub y}Mn{sub 1-y}O{sub 3} and Ba{sub 0.3}Sr{sub 0.7}Fe{sub 0.9}Mn{sub 0.1}O

  14. Integration of III-V materials and Si-CMOS through double layer transfer process

    Science.gov (United States)

    Lee, Kwang Hong; Bao, Shuyu; Fitzgerald, Eugene; Tan, Chuan Seng

    2015-03-01

    A method to integrate III-V compound semiconductor and SOI-CMOS on a common Si substrate is demonstrated. The SOI-CMOS layer is temporarily bonded on a Si handle wafer. Another III-V/Si substrate is then bonded to the SOI-CMOS containing handle wafer. Finally, the handle wafer is released to realize the SOI-CMOS on III-V/Si hybrid structure on a common substrate. Through this method, high temperature III-V materials growth can be completed without the presence of the temperature sensitive CMOS layer, hence damage to the CMOS layer is avoided.

  15. Repackaging of High Fissile TRU Waste at the Transuranic Waste Processing Center - 13240

    Energy Technology Data Exchange (ETDEWEB)

    Oakley, Brian; Heacker, Fred [WAI, TRU Waste Processing Center, 100 WIPP Road Lenoir City, TN 37771 (United States); McMillan, Bill [DOE, Oak Ridge Operations, Bldg. 2714, Oak Ridge, TN 37830 (United States)

    2013-07-01

    Twenty-six drums of high fissile transuranic (TRU) waste from Oak Ridge National Laboratory (ORNL) operations were declared waste in the mid-1980's and placed in storage with the legacy TRU waste inventory for future treatment and disposal at the Waste Isolation Pilot Plant (WIPP). Repackaging and treatment of the waste at the TRU Waste Packaging Center (TWPC) will require the installation of additional equipment and capabilities to address the hazards for handling and repackaging the waste compared to typical Contact Handled (CH) TRU waste that is processed at the TWPC, including potential hydrogen accumulation in legacy 6M/2R packaging configurations, potential presence of reactive plutonium hydrides, and significant low energy gamma radiation dose rates. All of the waste is anticipated to be repackaged at the TWPC and certified for disposal at WIPP. The waste is currently packaged in multiple layers of containers which presents additional challenges for repackaging activities due to the potential for the accumulation of hydrogen gas in the container headspace in quantities than could exceed the Lower Flammability Limit (LFL). The outer container for each waste package is a stainless steel 0.21 m{sup 3} (55-gal) drum which contains either a 0.04 m{sup 3} or 0.06 m{sup 3} (10-gal or 15-gal) 6M drum. The inner 2R container in each 6M drum is ∼12 cm (5 in) outside diameter x 30-36 cm (12-14 in) long and is considered to be a > 4 liter sealed container relative to TRU waste packaging criteria. Inside the 2R containers are multiple configurations of food pack cans, pipe nipples, and welded capsules. The waste contains significant quantities of high burn-up plutonium oxides and metals with a heavy weight percentage of higher atomic mass isotopes and the subsequent in-growth of significant quantities of americium. Significant low energy gamma radiation is expected to be present due to the americium in-growth. Radiation dose rates on inner containers are estimated

  16. High-flexibility combinatorial peptide synthesis with laser-based transfer of monomers in solid matrix material.

    Science.gov (United States)

    Loeffler, Felix F; Foertsch, Tobias C; Popov, Roman; Mattes, Daniela S; Schlageter, Martin; Sedlmayr, Martyna; Ridder, Barbara; Dang, Florian-Xuan; von Bojničić-Kninski, Clemens; Weber, Laura K; Fischer, Andrea; Greifenstein, Juliane; Bykovskaya, Valentina; Buliev, Ivan; Bischoff, F Ralf; Hahn, Lothar; Meier, Michael A R; Bräse, Stefan; Powell, Annie K; Balaban, Teodor Silviu; Breitling, Frank; Nesterov-Mueller, Alexander

    2016-06-14

    Laser writing is used to structure surfaces in many different ways in materials and life sciences. However, combinatorial patterning applications are still limited. Here we present a method for cost-efficient combinatorial synthesis of very-high-density peptide arrays with natural and synthetic monomers. A laser automatically transfers nanometre-thin solid material spots from different donor slides to an acceptor. Each donor bears a thin polymer film, embedding one type of monomer. Coupling occurs in a separate heating step, where the matrix becomes viscous and building blocks diffuse and couple to the acceptor surface. Furthermore, we can consecutively deposit two material layers of activation reagents and amino acids. Subsequent heat-induced mixing facilitates an in situ activation and coupling of the monomers. This allows us to incorporate building blocks with click chemistry compatibility or a large variety of commercially available non-activated, for example, posttranslationally modified building blocks into the array's peptides with >17,000 spots per cm(2).

  17. Melting of nanoparticle-enhanced phase change material inside an enclosure heated by laminar heat transfer fluid flow

    Science.gov (United States)

    Elbahjaoui, Radouane; El Qarnia, Hamid; El Ganaoui, Mohammed

    2016-05-01

    The proposed work presents a numerical investigation of the melting of a phase change material (PCM: Paraffin wax P116) dispersed with nanoparticles (Al2O3) in a latent heat storage unit (LHSU). The latter is composed of a number of vertical and identical slabs of nano-enhanced phase change material (NEPCM) separated by rectangular channels through which passes heat transfer fluid (HTF: water). A mathematical model based on the conservation equations of mass, momentum and energy has been developed. The resulting equations are discretized using the finite volume approach. The numerical model has been validated by experimental and numerical results published in literature. Numerical investigations have been conducted to evaluate the effects of the volumetric fraction of nanoparticles, HTF mass flow rate and inlet temperature on the latent heat storage unit's thermal behaviour and performance. Modelling results show that the volumetric fraction, HTF mass flow rate and inlet temperature need to be designed to achieve a significant improvement in thermal performance. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  18. High-flexibility combinatorial peptide synthesis with laser-based transfer of monomers in solid matrix material

    Science.gov (United States)

    Loeffler, Felix F.; Foertsch, Tobias C.; Popov, Roman; Mattes, Daniela S.; Schlageter, Martin; Sedlmayr, Martyna; Ridder, Barbara; Dang, Florian-Xuan; von Bojničić-Kninski, Clemens; Weber, Laura K.; Fischer, Andrea; Greifenstein, Juliane; Bykovskaya, Valentina; Buliev, Ivan; Bischoff, F. Ralf; Hahn, Lothar; Meier, Michael A. R.; Bräse, Stefan; Powell, Annie K.; Balaban, Teodor Silviu; Breitling, Frank; Nesterov-Mueller, Alexander

    2016-06-01

    Laser writing is used to structure surfaces in many different ways in materials and life sciences. However, combinatorial patterning applications are still limited. Here we present a method for cost-efficient combinatorial synthesis of very-high-density peptide arrays with natural and synthetic monomers. A laser automatically transfers nanometre-thin solid material spots from different donor slides to an acceptor. Each donor bears a thin polymer film, embedding one type of monomer. Coupling occurs in a separate heating step, where the matrix becomes viscous and building blocks diffuse and couple to the acceptor surface. Furthermore, we can consecutively deposit two material layers of activation reagents and amino acids. Subsequent heat-induced mixing facilitates an in situ activation and coupling of the monomers. This allows us to incorporate building blocks with click chemistry compatibility or a large variety of commercially available non-activated, for example, posttranslationally modified building blocks into the array's peptides with >17,000 spots per cm2.

  19. The theory of laser materials processing heat and mass transfer in modern technology

    CERN Document Server

    Schulz, Wolfgang

    2017-01-01

    The revised edition of this important reference volume presents an expanded overview of the analytical and numerical approaches employed when exploring and developing modern laser materials processing techniques. The book shows how general principles can be used to obtain insight into laser processes, whether derived from fundamental physical theory or from direct observation of experimental results. The book gives readers an understanding of the strengths and limitations of simple numerical and analytical models that can then be used as the starting-point for more elaborate models of specific practical, theoretical or commercial value. Following an introduction to the mathematical formulation of some relevant classes of physical ideas, the core of the book consists of chapters addressing key applications in detail: cutting, keyhole welding, drilling, arc and hybrid laser-arc welding, hardening, cladding and forming. The second edition includes a new a chapter on glass cutting with lasers, as employed in the ...

  20. Bi-gyrotropic single-negative magnetic materials in the presence of longitudinal magnetization: A transfer matrix approach

    Science.gov (United States)

    Hajesmaeili, Hamidreza Nezhad; Zamani, Mehdi; Zandi, Mohammad Hossein

    2017-05-01

    In a single-negative medium, electric permittivity (ɛ) or magnetic permeability (μ) coefficients are negative. In order to use the potential of magnetic metamaterials, in the present study, we have investigated bi-gyrotropic single-negative magnetic materials (BSNMMs) having their ɛ and μ in the form of non-diagonal tensors. At first, we have introduced a transfer matrix method (TMM)-based approach for studying optical and magneto-optical (MO) properties of BSNMMs and multilayer structures containing them in the case of longitudinal configuration of magnetization. Then, we have studied numerical computation on the reflection geometry for both ɛ-negative and μ-negative typical BSNMMs for different permittivity and permeability values.

  1. An efficient method and device for transfer of semisolid materials into solid-state NMR spectroscopy rotors.

    Science.gov (United States)

    Hisao, Grant S; Harland, Michael A; Brown, Robert A; Berthold, Deborah A; Wilson, Thomas E; Rienstra, Chad M

    2016-04-01

    The study of mass-limited biological samples by magic angle spinning (MAS) solid-state NMR spectroscopy critically relies upon the high-yield transfer of material from a biological preparation into the MAS rotor. This issue is particularly important for maintaining biological activity and hydration of semi-solid samples such as membrane proteins in lipid bilayers, pharmaceutical formulations, microcrystalline proteins and protein fibrils. Here we present protocols and designs for rotor-packing devices specifically suited for packing hydrated samples into Pencil-style 1.6 mm, 3.2 mm standard, and 3.2 mm limited speed MAS rotors. The devices are modular and therefore readily adaptable to other rotor and/or ultracentrifugation tube geometries.

  2. Measurement and modeling of energetic-material mass transfer to soil-pore water - Project CP-1227 final technical report.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Sallaberry, Cedric M.; Webb, Stephen Walter; Phelan, James M.; Hadgu, Teklu

    2006-05-01

    Military test and training ranges operate with live-fire engagements to provide realism important to the maintenance of key tactical skills. Ordnance detonations during these operations typically produce minute residues of parent explosive chemical compounds. Occasional low-order detonations also disperse solid-phase energetic material onto the surface soil. These detonation remnants are implicated in chemical contamination impacts to groundwater on a limited set of ranges where environmental characterization projects have occurred. Key questions arise regarding how these residues and the environmental conditions (e.g., weather and geostratigraphy) contribute to groundwater pollution. This final report documents the results of experimental and simulation model development for evaluating mass transfer processes from solid-phase energetics to soil-pore water.

  3. Theoretical Investigation on the Electron and Energy Transfer between Peripheral Carrier Transport Groups and Central Chromophores in Electroluminescent Materials

    Institute of Scientific and Technical Information of China (English)

    潘玉钰; 刘丹丹; 许海; 刘晓冬; 孙冠楠; 杨兵; 马於光

    2012-01-01

    The molecular materials with structures of luminescent core and peripheral carrier groups (e.g. carbazoles), have exhibited high-performance in organic light-emitting diodes (OLEDs). Present work is to understand the basic process of electronic and energy exchange between the peripheral functional groups and the central core through quantum chemical analysis. As an example, 4,7-bis(9,9-bis(6-(9H-carbazol-9-yl)hexyl)-9H-fluoren-2-yl)benzo[c]- [1,2,5]thiadiazole (TCBzC) is investigated in regards to optoelectronic properties using density functional theory (DFT). The results suggest that the forbidden transition from peripheral carbazole to the central chromophore core makes for separated electrical and optical properties, and high performance electroluminescence (EL) is mainly at- tributed to the energy-transfer from carbazoles to the fluorene derivative core.

  4. The influence of radical transfer and scavenger materials in various concentrations on the gamma radiolysis of phenol

    Science.gov (United States)

    Kozmér, Zsuzsanna; Takács, Erzsébet; Wojnárovits, László; Alapi, Tünde; Hernádi, Klára; Dombi, András

    2016-07-01

    The influence of a radical scavenger (tert-butanol (t-BuOH)) and two radical transfer materials (formic acid (HCOOH) and formate anion (HCOO-)) on the radical set during radiolysis of a simple model compound, phenol (PhOH, 1.0×10-4 mol L-1) is discussed in this study. PhOH solutions were irradiated with γ-rays, in the presence of 1.0×10-3, 5.0×10-2 and 5.0×10-1 mol L-1t-BuOH, HCOOH or HCOONa under deoxygenated and O2-saturated reaction conditions. The rate of transformation of PhOH increased significantly in the presence of dissolved O2. The radical transfer or scavenger materials used reduced the rates of transformation of PhOH in O2-saturated solutions to a similar degree. The simultaneous presence of O2 and the organic additives in excess proportionally to PhOH results in the conversion of the radical set to less reactive intermediates (t-•OOBuOH, HO2• or O2•-), which made minor contribution to the transformation of PhOH. Under oxygenated conditions, t-BuOH and HCOOH in low concentrations slightly promoted the degradation, as opposed to HCOO- which reduced it. However, using higher additive concentrations, their competitive reactions for the primary intermediates came into prominence, thus they reduced the efficiency of PhOH decomposition. HO2• and O2•-, and also the carbon-centred radicals formed (order of their reactivity t-•BuOH>•COOH> CO2•-) have only a minor contribution to the degradation of PhOH, and the reactions of •OH+PhOH and eaq-+PhOH are the significant processes.

  5. Fissility of actinide nuclei induced by 60-130 MeV photons; Fissionabilidade de nucleos actnideos induzida por fotons de energia 60-130 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Morcelle, Viviane; Tavares, Odilon A.P

    2004-06-15

    Nuclear fissilities obtained from recent photofission reaction cross section measurements carried out at Saskatchewan Accelerator Laboratory (Saskatoon, Canada) in the energy range 60-130 MeV for {sup 232} Th, {sup 233} U, {sup 235} U, {sup 238} U, and {sup 237} Np nuclei have been analysed in a systematic way. To this aim, a semiempirical approach has been developed based on the quasi-deuteron nuclear photoabsorption model followed by the process of competition between neutron evaporation and fission for the excited nucleus. The study reproduces satisfactorily well the increasing trend of nuclear fissility with parameter Z{sup 2}=A. (author)

  6. Effect of Different Disinfectants on Staphylococcus aureus and Candida albicans Transferred to Alginate and Polyvinylsiloxane Impression Materials

    Directory of Open Access Journals (Sweden)

    Fereydoun Parnia

    2009-12-01

    Full Text Available Background and aims. Several products have been marketed for disinfecting impression materials. The present study evaluated the effect of Deconex, Micro 10, Alprocid and Unisepta Plus sprays on Staphylococcus aureus and Candida albicans transferred to alginate and polyvinylsiloxane impression materials. Materials and methods. A total of 180 impressions of a maxillary model (90 alginate and 90 polyvinylsiloxane impressions were taken for the purpose of this in vitro study. Half of the impressions were infected with Staphylococcus aureus and the other half were infected with Candida albicans. Then the microorganisms were cultured and their counts were determined. Subsequently, the impressions were divided into groups of 15 impressions each. Each group was disinfected with Deconex, Micro10, Alprocid and Unisepta Plus according to manufacturers' instructions except for the control group. The culturing procedure was repeated after disinfection and microbial counts were determined again. Data was analyzed by ANOVA and paired-sample t-test. Results. There were statistically significant differences in the means of S. aureus and C. albicans counts before and after the use of disinfectants (P < 0.05. The use of the four disinfectants reduced S. aureus counts to zero in 80% of the cases. There were no statistically significant differences in S. aureus count reductions between the four disinfectants evaluated (P = 0.31. Micro 10 was more effective on alginate; Deconex was more efficient for polyvinylsiloxane and Alprocid had a better efficacy in both impression materials in eliminating C. albicans (P < 0.05. Conclusion. All the disinfectants evaluated have high disinfecting postentials.

  7. Measurement of Nucleate Pool Boiling Heat Transfer Limit using Fuel Cladding Material

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chi Young; Shin, Chang Hwan; Oh, Dong Seok; Chun, Tae Hyun; In, Wang Kee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Zircaloy has been widely used as a fuel cladding material of light water reactor for more than three decades because it has a lower neutron absorption cross section and cracking rate. Recently, HANA-6 has been developed in KAERI (Korea Atomic Energy Research Institute) as the advanced fuel cladding for high burn-up fuel. Generally, under the normal and accident operating conditions of a nuclear reactor, the nuclear fuel cladding of zirconium based alloys undergoes the surface change, and the oxide layer can be formed. In such a case, the previous CHF correlations should be assessed and examined using the experimental results for not a fresh zircaloy surface but an oxidized one, to predict and examine the thermal margin and safety of a nuclear reactor core. Therefore, the experimental data using the oxidized zircaloy surface need to be provided quantitatively. In this paper, the CHF in saturated water pool boiling is measured and discussed using the specimens of zircaloy-4, HANA-6, and oxidized zircaloy-4 in high temperature air environment. The CHF of zircaloy-4, HANA-6, and oxidized surface was tested. Zircaloy-4 and HANA-6 had a similar CHF performance. This is because both are the zirconium based alloys, and appear the almost same water contact angle. On the other hands, the oxidized specimen became to be higher CHF than plain zircaloy-4 and HANA-6 specimens, due to smaller water contact angle (i. e., good hydrophilicity of specimen). The Kandlikar's (2001) correlation reasonably predicted the present experimental data.

  8. Arsenic Contamination in Food-chain: Transfer of Arsenic into Food Materials through Groundwater Irrigation

    Science.gov (United States)

    Joardar, J.C.; Parvin, S.; Correll, Ray; Naidu, Ravi

    2006-01-01

    Arsenic contamination in groundwater in Bangladesh has become an additional concern vis-à-vis its use for irrigation purposes. Even if arsenic-safe drinking-water is assured, the question of irrigating soils with arsenic-laden groundwater will continue for years to come. Immediate attention should be given to assess the possibility of accumulating arsenic in soils through irrigation-water and its subsequent entry into the food-chain through various food crops and fodders. With this possibility in mind, arsenic content of 2,500 water, soil and vegetable samples from arsenic-affected and arsenic-unaffected areas were analyzed during 1999–2004. Other sources of foods and fodders were also analyzed. Irrigating a rice field with groundwater containing 0.55 mg/L of arsenic with a water requirement of 1,000 mm results in an estimated addition of 5.5 kg of arsenic per ha per annum. Concentration of arsenic as high as 80 mg per kg of soil was found in an area receiving arsenic-contaminated irrigation. A comparison of results from affected and unaffected areas revealed that some commonly-grown vegetables, which would usually be suitable as good sources of nourishment, accumulate substantially-elevated amounts of arsenic. For example, more than 150 mg/kg of arsenic has been found to be accumulated in arum (kochu) vegetable. Implications of arsenic ingested in vegetables and other food materials are discussed in the paper. PMID:17366772

  9. Mineralogy and microstructure of roofing slate: thermo-optical behaviour and fissility

    Directory of Open Access Journals (Sweden)

    García-Guinea, J.

    1998-09-01

    Full Text Available The mineralogy and microstructure, which affect the slaty cleavage, are linked with the strong preferred orientation of phyllosilicates and this enables the rock to be split into large, thin, flat sheets. Roofing slate samples with different commercial fissilities have been analyzed by radioluminescence (RL, thermoluminescence (3DTL, by X-ray diffraction (XRD, by scanning electron microscopy (SEM using the back-scattered mode (BSEI and by electron microprobe (EMP. They are made up of white micas, chlorite, quartz, detrital feldspars, ilmenite, pyrite, rutile apatite and tourmaline. Texturally, all consist of silt-sized clasts of detrital quartz, feldspars, chlorite-mica stacks, muscovite and ilmenite in a recrystalline, lepidoblastic matrix of white micas and chlorite with quartz lenses, all showing a very strong preferred orientation. The luminescence emission centers are a low broad blue band around the 400 nm spectra positions linked with alkali losses and formation of [AlO4]º defects; a peak at 473 nm interpreted as a the first thermal step (150-300ºC of a non-isothermal dehydroxylation of the slate phyllosilicates; and a 568 nm peak which agrees with Mn2+ point defects in aluminosilicate lattices. The studies on the slaty cleavage could be significant because Spain is the largest producer of roofing slate tiles in the world (87% of world production.

    La exfoliación de las pizarras depende fundamentalmente de su mineralogía y microestructura, especialmente de la fuerte orientación de los filosilicatos. Esta propiedad permite hendir o abrir las pizarras de techar en láminas muy grandes, delgadas y planas. Se han analizado varias pizarras de techar con diferentes calidades comerciales, correspondientes a diferentes grados de físibilidad, por radioluminiscencia (RL, termoluminiscencia espectral (TL3D, difracción de rayos X (DRX, microscopía electrónica de barrido (MEB utilizando el modo backscattered (BSEI

  10. Material Transfer in Boundary of the Compressor Fins%压缩机散热片附面层内物质的传递

    Institute of Scientific and Technical Information of China (English)

    许大钊; 刘海江

    2013-01-01

    分析了附面层内质量传递、动量传递以及能量传递的基本特性,运用质量守恒定律、动量定理以及能量守恒定律等基本物理原理,描述了附面层内物质传递的基本方程以及附面层内物质传递对附面层厚度的影响.%This paper has analyzed the basic characteristics of the mass transfer,momentum transfer and energy transfer in the bounder layer.The mass conservation law,momentum theorem and energy conservation law have been applied to describe the basic equation of the mterial transfer in the bounder layer and the influence of material transfer on thickness of the boundary layer.

  11. Heat transfer within hydrodissection fluids: An analysis of thermal conduction and convection using liquid and gel materials.

    Science.gov (United States)

    Johnson, Alexander; Brace, Christopher

    2015-01-01

    Interventional oncology procedures such as thermal ablation are becoming widely used for many tumours in the liver, kidney and lung. Thermal ablation refers to the focal destruction of tissue by generating cytotoxic temperatures in the treatment zone. Hydrodissection - separating tissues with fluids - protects healthy tissues adjacent to the ablation treatment zone to improve procedural safety, and facilitate more aggressive power application or applicator placement. However, fluids such as normal saline and 5% dextrose in water (D5W) can migrate into the peritoneum, reducing their protective efficacy. As an alternative, a thermo-gelable poloxamer 407 (P407) solution has been recently developed to facilitate hydrodissection procedures. We hypothesise that the P407 gel material does not provide convective heat dissipation from the ablation site, and therefore may alter the heat transfer dynamics compared to liquid materials during hydrodissection-assisted thermal ablation. The purpose of this study was to investigate the heat dissipation mechanics within D5W, liquid P407 and gel P407 hydrodissection barriers. Overall it was shown that the gel P407 dissipated heat primarily through conduction, whereas the liquid P407 and D5W dissipated heat through convection. Furthermore, the rate of temperature change within the gel P407 was greater than liquid P407 and D5W. Testing to evaluate the in vivo efficacy of the fluids with different modes of heat dissipation seems warranted for further study.

  12. Control of structural inheritance on thrust initiation and material transfer in accretionary wedges

    Science.gov (United States)

    Leever, Karen; Geersen, Jacob; Ritter, Malte; Lieser, Kathrin; Behrmann, Jan

    2016-04-01

    Faults in the incoming sediment layer are commonly observed in subduction zone settings and well developed in the incoming plate off Sumatra. To investigate how they affect the structural development of the accretionary wedge, we conducted a series of 2D analogue tectonic experiments in which a 2 cm thick quartz sand layer on top of a thin detachment layer of glass beads was pulled against a rigid backstop by a basal conveyor belt in a 20cm wide box with glass walls. A gap at the base of the back wall avoids entrainment of the glass beads. At regular spacing of either 2.3, 5.5 or 7.8 cm (fractions of the thrust sheet length in the reference model), conjugate pairs of weakness zones dipping 60deg were created by cutting the sand layer with a thin (1 mm) metal blade. Both the undisturbed sand and the pre-cuts have an angle of internal friction of ~29o, but their cohesion is different by 50 Pa (110 Pa for the undisturbed material, 60 Pa along the pre-cuts). Friction of the glass beads is ~24deg. The experiments are monitored with high resolution digital cameras; displacement fields derived from digital image correlation are used to constrain fault activity. In all experiments, a critically tapered wedge developed with a surface slope of 7.5deg. In the reference model (no weakness zones in the input section), the position of new thrust faults is controlled by the frontal slope break. The average length of the thrust sheets is 11 cm and the individual thrusts accommodate on average 8 cm displacement each. The presence of weakness zones causes thrust initiation at a position different from the reference case, and affects their dip. For a fault spacing of 7.8 cm (or 75% of the reference thrust sheet length), every single incoming weakness zone causes the formation of a new thrust, thus resulting in thrust sheets shorter than the equilibrium case. In addition, less displacement is accommodated on each thrust. As a consequence, the frontal taper is smaller than expected

  13. Protein standardization IV: Value transfer procedure for the assignment of serum protein values from a reference preparation to a target material.

    Science.gov (United States)

    Blirup-Jensen, S; Johnson, A M; Larsen, M

    2001-11-01

    A new approach for the assignment of values to serum proteins in a target material using a reference preparation has been developed. The procedure describes the general as well as the practical principles involved in the value assignment (with examples). Two models have been developed: 1) The direct value transfer between serum matrices and 2) the indirect value transfer from a pure protein preparation to a serum protein material. The necessary mathematical equations are developed and explained. The data reduction and statistical evaluation are discussed. The practical procedure (the transfer protocol) is based on six dilutions of the reference preparation assayed together with six dilutions of the target material. In this way imprecision is reduced and the proportionality of the two materials (i.e. the presence or absence of matrix effects) can be assessed directly by evaluating a single regression plot. If no matrix effects are found, the regression line will pass through zero with a slope equal to the ratio of the concentrations of the two materials. The transfer protocol is based on a multiple point value assignment obtained by several measurements a day repeated on several days, an important prerequisite being that all reconstitutions and dilutions are controlled by weighing.

  14. Characterization of a suspect nuclear fuel rod in a case of illegal international traffic of fissile material.

    Science.gov (United States)

    Capannesi, G; Vicini, C; Rosada, A; Avino, P

    2010-06-15

    This case study describes the characterization of a suspect rod of nuclear fuel seized in Italy: on request of the coroner, the characterization concerned the kind and the conditions of the rod, the amount and the specific characteristics of the species present in it, with particular attention to their possible use chemical and/or nuclear plants. The methodology used was based on radiochemical analyses (gammagraphic and gamma-spectrometry) whereas the comparison was performed by means of a fuel reference element working in the TRIGA nuclear reactor at Research Center of ENEA-Casaccia. The results show clearly how the exhibit was an element of nuclear fuel, how long it was irradiated, and the amount of (239)Pu produced and the (235)U consumed. Finally, even if the seized rod was briefly radiated at the "zero power" and traces of fission products and plutonium were found, it would be still usable as "fresh" fuel in a reactor type TRIGA if it had not been intercepted by Italian police authorities.

  15. APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE AND CHLORIDE FROM LEGACY FISSILE MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, R.; Peters, T.

    2011-11-01

    Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and the Savannah River Site (SRS) HB-Line Facility designed, developed, tested, and successfully deployed a production-scale system for the distillation of sodium chloride (NaCl) and potassium chloride (KCl) from plutonium oxide (PuO{sub 2}). Subsequent efforts adapted the vacuum salt distillation (VSD) technology for the removal of chloride and fluoride from less-volatile halide salts at the same process temperature and vacuum. Calcium chloride (CaCl{sub 2}), calcium fluoride (CaF{sub 2}), and plutonium fluoride (PuF{sub 3}) were of particular concern. To enable the use of the same operating conditions for the distillation process, SRNL employed in situ exchange reactions to convert the less-volatile halide salts to compounds that facilitated the distillation of halide without removal of plutonium. SRNL demonstrated the removal of halide from CaCl{sub 2}, CaF{sub 2} and PuF{sub 3} below 1000 C using VSD technology.

  16. Blend Down Monitoring System Fissile Mass Flow Monitor Implementation at the ElectroChemical Plant, Zelenogorsk, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, T.

    2005-11-11

    The implementation plans and preparations for installation of the Fissile Mass Flow Monitor (FMFM) equipment at the ElectroChemical Plant (ECP), Zelenogorsk, Russia, are presented in this report. The FMFM, developed at Oak Ridge National Laboratory, is part of the Blend Down Monitoring System (BDMS), developed for the U.S. Department of Energy Highly Enriched Uranium (HEU) Transparency Implementation Program. The BDMS provides confidence to the United States that the Russian nuclear facilities supplying the lower-assay ({approx}4%) product low enriched uranium (P-LEU) to the United States from down-blended weapons-grade HEU are meeting the nonproliferation goals of the government-to-government HEU Purchase Agreement, signed between the Russian Federation and the United States in 1993. The first BDMS has been operational at Ural Electrochemical Integrated Plant, Novouralsk, since February 1999 and is successfully providing HEU transparency data to the United States. The second BDMS was installed at ECP in February 2003. The FMFM makes use of a set of thermalized californium-252 ({sup 252}Cf) spontaneous neutron sources for a modulated fission activation of the UF{sub 6} gas stream for measuring the {sup 235}U fissile mass flow rate. To do this, the FMFM measures the transport time of the fission fragments created from the fission activation process under the modulated source to the downstream detectors by detecting the delayed gamma rays from the fission fragments. The FMFM provides unattended, nonintrusive measurements of the {sup 235}U mass flow in the HEU, LEU blend stock, and P-LEU process legs. The FMFM also provides the traceability of the HEU flow to the product process leg. This report documents the technical installation requirements and the expected operational characteristics of the ECP FMFM.

  17. Frequency-selective near-field radiative heat transfer between photonic crystal slabs: a computational approach for arbitrary geometries and materials.

    Science.gov (United States)

    Rodriguez, Alejandro W; Ilic, Ognjen; Bermel, Peter; Celanovic, Ivan; Joannopoulos, John D; Soljačić, Marin; Johnson, Steven G

    2011-09-09

    We demonstrate the possibility of achieving enhanced frequency-selective near-field radiative heat transfer between patterned (photonic-crystal) slabs at designable frequencies and separations, exploiting a general numerical approach for computing heat transfer in arbitrary geometries and materials based on the finite-difference time-domain method. Our simulations reveal a tradeoff between selectivity and near-field enhancement as the slab-slab separation decreases, with the patterned heat transfer eventually reducing to the unpatterned result multiplied by a fill factor (described by a standard proximity approximation). We also find that heat transfer can be further enhanced at selective frequencies when the slabs are brought into a glide-symmetric configuration, a consequence of the degeneracies associated with the nonsymmorphic symmetry group.

  18. Detecting fission from special nuclear material sources

    Science.gov (United States)

    Rowland, Mark S.; Snyderman, Neal J.

    2012-06-05

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a graphing component that displays the plot of the neutron distribution from the unknown source over a Poisson distribution and a plot of neutrons due to background or environmental sources. The system further includes a known neutron source placed in proximity to the unknown source to actively interrogate the unknown source in order to accentuate differences in neutron emission from the unknown source from Poisson distributions and/or environmental sources.

  19. Significant effect of electron transfer between current collector and active material on high rate performance of Li4Ti5O12

    Institute of Scientific and Technical Information of China (English)

    Pan Hui-Lin; Hu Yong-Sheng; Li Hong; Chen Li-Quan

    2011-01-01

    The rate and cycling performances of the electrode materials are affected by many factors in a practical complicated electrode process.Learning about the limiting step in a practical electrochemical reaction is very important to effectively improve the electrochemical performances of the electrode materials.Li4TisO12,as a zero-strain material,has been considered as a promising anode material for long life Li-ion batteries.In this study,our results show that the Li4Ti5O12 pasted on Cu or graphite felt current collector exhibits unexpectedly higher rate performance than on Al current collector.For Li4Ti5O12,the electron transfer between current collector and active material is the critical factor that affects its rate and cycling performances.

  20. The Statistics of Emission and Detection of Neutrons and Photons from Fissile Samples for Safeguard Applications

    Energy Technology Data Exchange (ETDEWEB)

    Enqvist, Andreas

    2008-03-15

    One particular purpose of nuclear safeguards, in addition to accounting for known materials, is the detection, identifying and quantifying unknown material, to prevent accidental and clandestine transports and uses of nuclear materials. This can be achieved in a non-destructive way through the various physical and statistical properties of particle emission and detection from such materials. This thesis addresses some fundamental aspects of nuclear materials and the way they can be detected and quantified by such methods. Factorial moments or multiplicities have long been used within the safeguard area. These are low order moments of the underlying number distributions of emission and detection. One objective of the present work was to determine the full probability distribution and its dependence on the sample mass and the detection process. Derivation and analysis of the full probability distribution and its dependence on the above factors constitutes the first part of the thesis. Another possibility of identifying unknown samples lies in the information in the 'fingerprints' (pulse shape distribution) left by a detected neutron or photon. A study of the statistical properties of the interaction of the incoming radiation (neutrons and photons) with the detectors constitutes the second part of the thesis. The interaction between fast neutrons and organic scintillation detectors is derived, and compared to Monte Carlo simulations. An experimental approach is also addressed in which cross correlation measurements were made using liquid scintillation detectors. First the dependence of the pulse height distribution on the energy and collision number of an incoming neutron was derived analytically and compared to numerical simulations. Then an algorithm was elaborated which can discriminate neutron pulses from photon pulses. The resulting cross correlation graphs are analyzed and discussed whether they can be used in applications to distinguish possible

  1. Blend Down Monitoring System Fissile Mass Flow Monitor and its Implementation at the Siberian Chemical Enterprise, Seversk, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, T

    2005-07-28

    In this paper the implementation plans and preparations for installation of the Fissile Mass Flow Monitor (FMFM) equipment at the Siberian Chemical Enterprise (SChE), Seversk, Russia, are presented. The FMFM, developed by Oak Ridge National Laboratory, is part of the Blend Down Monitoring System (BDMS) for the U.S. Department of Energy Highly Enriched Uranium (HEU) Transparency Implementation Program. The BDMS provides confidence to the United States that the Russian nuclear facilities supplying the lower assay ({approx}4%) product low enriched uranium (PLEU) to the United States from down-blended weapon-grade HEU are meeting the nonproliferation goals of the government-to-government HEU purchase agreement signed between the Russian Federation and the United States in 1993. The first BDMS has been operational at Ural Electrochemical Integrated Plant, Novouralsk, since February 1999. The second BDMS has been operational at Electro Chemical Plant, Zelenogorsk, since March 2003. These systems are successfully providing HEU transparency data to the United States. The third BDMS was successfully installed on the HEU down-blending tee in the SChE Enrichment Plant in October 2004. The FMFM makes use of a set of thermalized {sup 252}Cf spontaneous neutron sources for modulated fission activation of the UF{sub 6} gas stream for measuring the {sup 235}U fissile mass flow rate. To do this, the FMFM measures the transport time of the fission fragments created from the fission activation process under the modulated source to the downstream detectors by detecting the delayed gamma rays from the fission fragments retained in the flow. The FMFM provides unattended nonintrusive measurements of the {sup 235}U mass flow of the UF{sub 6} gas in the blending tee legs of HEU, the LEU blend stock, and the resulting P-LEU. The FMFM also confirms that highly enriched UF{sub 6} gas identified in the HEU leg flows through the blending tee into the P-LEU leg. This report contains details of

  2. Photofission cross section and fissility of pre-actinide and intermediate-mass nuclei by 120- and 145-MeV Compton backscattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Terranova, M.L. [Istituto Nazionale di Fisica Nucleare, Rome (Italy); Kezerashvili, G. Ya.; Milov, A.M. [Russian Academy of Sciences, Moscow (Russian Federation). Budker Inst. of Nuclear Physics] [and others

    1997-09-01

    Cross section measurements for photofission induced in {sup 209} Bi, {sup natP}b, {sup 197} Au, {sup nat} Pt, nat{sub w}, {sup 181} Ta, {sup 51} V and {sup nat} Ti by 120- and 145-MeV quasi-monochromatic photon beams have been performed at the ROKK-1M facility (BINP, Novosibirsk). The fission yields have been obtained using Makrofol sheets as solid-state fission track detectors. Nuclear fissility values have been deduced on the basis of Levinger`s modified quasi-deuteron model of photonuclear interaction, and compared with available literature data. The trend of fissility in the 60-145 MeV energy range has been analysed for various target nuclei as function of energy and of parameter Z{sup 2}/A. (author) 30 refs., 6 figs., 4 tabs.

  3. Hydrogen transfer reaction of cyclohexanone with 2-propanol catalysed by CeO2-ZnO materials: Promoting effect of ceria

    Indian Academy of Sciences (India)

    Braja Gopal Mishra; G Ranga Rao; B Poongodi

    2003-10-01

    Ce-Zn-O mixed oxides were prepared by amorphous citrate process and decomposition of the corresponding acetate precursors. The resulting materials were characterised by TGA, XRD, UV-Vis-DRS, EPR, SEM and surface area measurements. XRD and DRS results indicated fine dispersion of the ceria component in the ZnO matrix. EPR results clearly indicate the presence of oxygen vacancy and defect centres in the composite oxide. Addition of CeO2 to ZnO produced mixed oxides of high surface area compared to the pure ZnO. Hydrogen transfer reaction was carried out on these catalytic materials to investigate the effect of rare earth oxide on the activity of ZnO. Addition of ceria into zinc oxide was found to increase the catalytic activity for hydrogen transfer reaction. The catalytic activity also depended on the method of preparation. Citrate process results in uniformly dispersed mixed oxide with higher catalytic activity.

  4. THERMAL UPGRADING OF 9977 RADIOACTIVE MATERIAL (RAM) TYPE B PACKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.; Abramczyk, G.

    2012-03-26

    The 9977 package is a radioactive material package that was originally certified to ship Heat Sources and RTG contents up to 19 watts and it is now being reviewed to significantly expand its contents in support of additional DOE missions. Thermal upgrading will be accomplished by employing stacked 3013 containers, a 3013 aluminum spacer and an external aluminum sleeve for enhanced heat transfer. The 7th Addendum to the original 9977 package Safety Basis Report describing these modifications is under review for the DOE certification. The analyses described in this paper show that this well-designed and conservatively analyzed package can be upgraded to carry contents with decay heat up to 38 watts with some simple design modifications. The Model 9977 package has been designed as a replacement for the Department of Transportation (DOT) Fissile Specification 6M package. The 9977 package is a very versatile Type B package which is certified to transport and store a wide spectrum of radioactive materials. The package was analyzed quite conservatively to increase its usefulness and store different payload configurations. Its versatility is evident from several daughter packages such as the 9978 and H1700, and several addendums where the payloads have been modified to suit the Shipper's needs without additional testing.

  5. Porcelain enamel neutron absorbing material

    Science.gov (United States)

    Iverson, Daniel C.

    1990-01-01

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

  6. Final Technical Report for the Energy Frontier Research Center Understanding Charge Separation and Transfer at Interfaces in Energy Materials (EFRC:CST)

    Energy Technology Data Exchange (ETDEWEB)

    Vanden Bout, David A. [Univ. of Texas, Austin, TX (United States)

    2015-09-14

    Our EFRC was founded with the vision of creating a broadly collaborative and synergistic program that would lead to major breakthroughs in the molecular-level understanding of the critical interfacial charge separation and charge transfer (CST) processes that underpin the function of candidate materials for organic photovoltaic (OPV) and electrical-energy-storage (EES) applications. Research in these energy contexts shares an imposing challenge: How can we understand charge separation and transfer mechanisms in the presence of immense materials complexity that spans multiple length scales? To address this challenge, our 50-member Center undertook a total of 28 coordinated research projects aimed at unraveling the CST mechanisms that occur at interfaces in these nanostructured materials. This rigorous multi-year study of CST interfaces has greatly illuminated our understanding of early-timescale processes (e.g., exciton generation and dissociation dynamics at OPV heterojunctions; control of Li+-ion charging kinetics by surface chemistry) occurring in the immediate vicinity of interfaces. Program outcomes included: training of 72 graduate student and postdoctoral energy researchers at 5 institutions and spanning 7 academic disciplines in science and engineering; publication of 94 peer-reviewed journal articles; and dissemination of research outcomes via 340 conference, poster and other presentations. Major scientific outcomes included: implementation of a hierarchical strategy for understanding the electronic communication mechanisms and ultimate fate of charge carriers in bulk heterojunction OPV materials; systematic investigation of ion-coupled electron transfer processes in model Li-ion battery electrode/electrolyte systems; and the development and implementation of 14 unique technologies and instrumentation capabilities to aid in probing sub-ensemble charge separation and transfer mechanisms.

  7. Heat and Mass Transfer in the Chemical Vapor Deposition of Silicon Carbide in a Porous Carbon-Carbon Composite Material for a Heat Shield

    Science.gov (United States)

    Reznik, S. V.; Mikhailovskii, K. V.; Prosuntsov, P. V.

    2017-03-01

    Physical and mathematical simulations of the chemical vapor deposition of silicon carbide in a porous carbon-carbon composite material in a chemical vapor deposition reactor for formation of a matrix of a carbon-ceramic composite material for a heat shield of an aerospace aircraft have been performed. Results of parametric calculations of the heat and mass transfer at the macro- and microlevels in representative elements of the microstructure of carbon-carbon composite materials different in residual porosity at different temperatures in the reaction zone of the reactor are presented. Features of compaction of the pore space of a carbon-carbon composite material by a silicon-carbide matrix depending on the technological parameters of the reaction medium were analyzed.

  8. Analysis of Electron and Antineutrino Energy Spectra from Fissile Samples under Irradiation based on Gross Theory of Beta-decay

    Science.gov (United States)

    Yoshida, T.; Tachibana, T.; Chiba, S.

    2016-06-01

    We applied the gross theory of β-decay to calculate the reactor electron and antineutrino ({{{bar ν }}{e}}) spectra emitted from 235,238U and 239,241Pu by summing up all the contributions from a large number of decaying fission-products (FPs). We make it clear what kinds of transition types and FP nuclides are important to shape the lepton spectra. After taking the ambiguity in the current data for fission yields and Qβ-values into account, we suggested a possibility that the high-energy part of the widely referred electron-spectra by Schreckenbach et al., almost only one experimental data set available now, might possibly be too low. Arguments on a special role of the odd(Z)-odd(N) nuclides and on the consistency between U-238 and other fissiles in the experimental data lead to the importance of a new and independent measurement of electron energy spectra which could be converted into the reactor {{{bar ν }}{e}} spectra.

  9. Synthesis of neutron-rich transuranic nuclei in fissile spallation targets

    CERN Document Server

    Mishustin, Igor; Pshenichnov, Igor; Greiner, Walter

    2014-01-01

    A possibility of synthesizing neutron-reach super-heavy elements in spallation targets of Accelerator Driven Systems (ADS) is considered. A dedicated software called Nuclide Composition Dynamics (NuCoD) was developed to model the evolution of isotope composition in the targets during a long-time irradiation by intense proton and deuteron beams. Simulation results show that transuranic elements up to Bk-249 can be produced in multiple neutron capture reactions in macroscopic quantities. However, the neutron flux achievable in a spallation target is still insufficient to overcome the so-called fermium gap. Further optimization of the target design, in particular, by including moderating material and covering it by a reflector will turn ADS into an alternative source of transuranic elements in addition to nuclear fission reactors.

  10. Study on heat transfer characteristics of the one side-heated vertical channel with inserted porous materials applied as a vessel cooling system

    Directory of Open Access Journals (Sweden)

    Shinji Kuriyama

    2015-08-01

    Full Text Available In the very high temperature reactor (VHTR, which is a next generation nuclear reactor system, ceramics are used as a fuel coating material and graphite is used as a core structural material. Even if a depressurization accident occurs and the reactor power goes up instantly, the temperature of the core will change only slowly. This is because the thermal capacity of the core is so high. Therefore, the VHTR system can passively remove the decay heat of the core by natural convection and radiation from the surface of the reactor pressure vessel. The objectives of this study are to investigate the heat transfer characteristics of natural convection of a one-side heated vertical channel with inserted porous materials of high porosity and also to develop the passive cooling system for the VHTR. An experiment was carried out using a one-side heated vertical rectangular channel. To obtain the heat transfer and fluid flow characteristics of the vertical channel with inserted porous material, we have also carried out a numerical analysis using a commercial Computational Fluid Dynamics (CFD code. This paper describes the thermal performances of the one-side heated vertical rectangular channel with an inserted copper wire of high porosity.

  11. Investigation of electronic band structure and charge transfer mechanism of oxidized three-dimensional graphene as metal-free anodes material for dye sensitized solar cell application

    Science.gov (United States)

    Loeblein, Manuela; Bruno, Annalisa; Loh, G. C.; Bolker, Asaf; Saguy, Cecile; Antila, Liisa; Tsang, Siu Hon; Teo, Edwin Hang Tong

    2017-10-01

    Dye-sensitized solar cells (DSSCs) offer an optimal trade-off between conversion-efficiency and low-cost fabrication. However, since all its electrodes need to fulfill stringent work-function requirements, its materials have remained unchanged since DSSC's first report early-90s. Here we describe a new material, oxidized-three-dimensional-graphene (o-3D-C), with a band gap of 0.2 eV and suitable electronic band-structure as alternative metal-free material for DSSCs-anodes. o-3D-C/dye-complex has a strong chemical bonding via carboxylic-group chemisorption with full saturation after 12 sec at capacity of ∼450 mg/g (600x faster and 7x higher than optimized metal surfaces). Furthermore, fluorescence quenching of life-time by 28-35% was measured demonstrating charge-transfer from dye to o-3D-C.

  12. Non-Planar Nano-Scale Fin Field Effect Transistors on Textile, Paper, Wood, Stone, and Vinyl via Soft Material-Enabled Double-Transfer Printing

    KAUST Repository

    Rojas, Jhonathan Prieto

    2015-05-01

    The ability to incorporate rigid but high-performance nano-scale non-planar complementary metal-oxide semiconductor (CMOS) electronics with curvilinear, irregular, or asymmetric shapes and surfaces is an arduous but timely challenge in enabling the production of wearable electronics with an in-situ information-processing ability in the digital world. Therefore, we are demonstrating a soft-material enabled double-transfer-based process to integrate flexible, silicon-based, nano-scale, non-planar, fin-shaped field effect transistors (FinFETs) and planar metal-oxide-semiconductor field effect transistors (MOSFETs) on various asymmetric surfaces to study their compatibility and enhanced applicability in various emerging fields. FinFET devices feature sub-20 nm dimensions and state-of-the-art, high-κ/metal gate stack, showing no performance alteration after the transfer process. A further analysis of the transferred MOSFET devices, featuring 1 μm gate length exhibits ION ~70 μA/μm (VDS = 2 V, VGS = 2 V) and a low sub-threshold swing of around 90 mV/dec, proving that a soft interfacial material can act both as a strong adhesion/interposing layer between devices and final substrate as well as a means to reduce strain, which ultimately helps maintain the device’s performance with insignificant deterioration even at a high bending state.

  13. High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers

    CERN Document Server

    Maciariello, Fausto; Butcher, Mark; Calviani, Marco; Folch, Ramon; Kain, Verena; Karagiannis, Konstantinos; Lamas Garcia, Inigo; Lechner, Anton; Nuiry, Francois-Xavier; Steele, Genevieve; Uythoven, Jan

    2016-01-01

    In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the resul...

  14. Preparation of Highly Dispersed Reduced Graphene Oxide Decorated with Chitosan Oligosaccharide as Electrode Material for Enhancing the Direct Electron Transfer of Escherichia coli.

    Science.gov (United States)

    Luo, Zhimin; Yang, Dongliang; Qi, Guangqin; Yuwen, Lihui; Zhang, Yuqian; Weng, Lixing; Wang, Lianhui; Huang, Wei

    2015-04-29

    Water-dispersed reduced graphene oxide/chitosan oligosaccharide (RGO-CTSO) was prepared by chemical reduction of graphene oxide and synchronous functionalization with biocompatible chitosan oligosaccharide (CTSO). ζ potential measurement indicated that RGO-CTSO was highly stable in the acidic aqueous solution. RGO-CTSO was used to modify glassy carbon electrode (GCE) as the growth template of Escherichia coli (E. coli). The enhanced direct electron transfer of E. coli on the RGO-CTSO-modified GCE was studied by cyclic voltammetry. Compared with GCE or RGO-modified GCE, RGO-CTSO-modified GCE was more suitable for the adhesion growth of E. coli to improve direct electron transfer. The biocompatibility and versatility of RGO-CTSO made it promising for use as an anode material in microbial fuel cells.

  15. Layer-by-Layer Assembled Films of Perylene Diimide- and Squaraine-Containing Metal-Organic Framework-like Materials: Solar Energy Capture and Directional Energy Transfer.

    Science.gov (United States)

    Park, Hea Jung; So, Monica C; Gosztola, David; Wiederrecht, Gary P; Emery, Jonathan D; Martinson, Alex B F; Er, Süleyman; Wilmer, Christopher E; Vermeulen, Nicolaas A; Aspuru-Guzik, Alán; Stoddart, J Fraser; Farha, Omar K; Hupp, Joseph T

    2016-09-28

    We demonstrate that thin films of metal-organic framework (MOF)-like materials, containing two perylenediimides (PDICl4, PDIOPh2) and a squaraine dye (S1), can be fabricated by layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and facilitate directional energy transfer. Due to the high spectral overlap and oriented transition dipole moments of the donor (PDICl4 and PDIOPh2) and acceptor (S1) components, directional long-range energy transfer from the bluest to reddest absorber was successfully demonstrated in the multicomponent MOF-like films. These findings have significant implications for the development of solar energy conversion devices based on MOFs.

  16. VOC mass transfer characteristic features of dry building materials%干建材挥发性有机化合物传质特性

    Institute of Scientific and Technical Information of China (English)

    宋伟; 孔庆媛; 李洪枚

    2012-01-01

    This paper is inclined to present our research findings on the characteristic features of the VOC mass transfer in the dry building materials and their influence on the environment while developing the corresponding testing methods. As is known, volatile organiccompounds (VOC) emission/adsorption mass transfer is one of the most significant factors causing indoor air pollution. It may bring about serious toxic effects on human health through indoor use of wooden or metallic furniture. For this purpose, we would like to discuss the inadequacies of current methods and models in this connection and then introduce our improved mass transfer mechanism based on the analytical model of describing VOC emission/adsorption of dry materials in static chamber with Laplace Transform on the equatiori both of Fick' s second law and indoor mass equilibrium theory under a series of rational boundary and initial conditions. Specific discussion has been given in this paper to the form of the model, which is featured with our analysis of the dominant relation between independent and dependent variables. What's more, we have developed a method for testing all the key VOC mass transfer parameters (the initial emission concentration, the diffusion coefficient and partition coefficient) through experiments in static chamber and specific numerical calculation while giving necessary deduction to the model. Thus, we have determined the materials' mass transfer characteristics in combination with the proper selection of environmental chambers in three days, which is worthy of reference to engineering practice. In addition, we have also laid out and conducted experiments involving various VOC from wood furniture with different degrees of complexity typical for the common dry materials, in which application effects of both the model and method were profoundly analyzed. According to the experimental data, we have shown all the correlation coefficients that could meet the demands of the

  17. Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry

    Science.gov (United States)

    Gupta, Sanju; Irihamye, Aline

    2015-03-01

    Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py-1SO3), 1-pyrenemethylamine salt (Py - Me-NH2) and Pluronic® P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr_LPE) are characterized by a combination of analytical (microscopy and spectroscopy) techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs) namely, monolayer graphene, Gr_LPE (the one prepared with Pluronic® P-123), graphene oxide (GO) and its reduced form (rGO) on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c) [for electron transfer], myoglobin (Mb) [for oxygen storage] and horseradish peroxidase (HRP) [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET) kinetics and attempt to determine the rate constant (kET) using two different analytical approaches namely, linear sweep voltammetry and Laviron's theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure) upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical wiring of the redox centers (with an

  18. Nonlinear transient heat transfer and thermoelastic analysis of thick-walled FGM cylinder with temperature-dependent material properties using Hermitian transfinite element

    Energy Technology Data Exchange (ETDEWEB)

    Azadi, Mohammad [Sharif University of Technology, Tehran (Iran, Islamic Republic of); Azadi, Mahboobeh [Shiraz University, Shiraz (Iran, Islamic Republic of)

    2009-10-15

    Nonlinear transient heat transfer and thermoelastic stress analyses of a thick-walled FGM cylinder with temperature dependent materials are performed by using the Hermitian transfinite element method. Temperature-dependency of the material properties has not been taken into account in transient thermoelastic analysis, so far. Due to the mentioned dependency, the resulting governing FEM equations of transient heat transfer are highly nonlinear. Furthermore, in all finite element analysis performed so far in the field, Lagrangian elements have been used. To avoid an artificial local heat source at the mutual boundaries of the elements, Hermitian elements are used instead in the present research. Another novelty of the present paper is simultaneous use of the transfinite element method and updating technique. Time variations of the temperature, displacements, and stresses are obtained through a numerical Laplace inversion. Finally, results obtained considering the temperature-dependency of the material properties are compared with those derived based on temperature independency assumption. Furthermore, the temperature distribution and the radial and circumferential stresses are investigated versus time, geometrical parameters and index of power law. Results reveal that the temperature-dependency effect is significant

  19. Controlled Environment Specimen Transfer

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Zandbergen, Henny W.; Hansen, Thomas Willum

    2014-01-01

    Specimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking an environme...

  20. Heat transfer and material temperature conditions in the leading edge area of impingement-cooled turbine vanes

    Science.gov (United States)

    Berg, H. P.; Pfaff, K.; Hennecke, D. K.

    The resultant effects on the cooling effectiveness at the leading edge area of an impingement-cooled turbine vane by varying certain geometrical parameters is described with reference to local internal heat transfer coefficients determined from experiment and temperature calculations. The local heat transfer on the cooling-air side is determined experimentally with the aid of the analogy between heat- and mass transfer. The impingement cooling is provided from an inserted sheet-metal containing a single row of holes. The Reynolds Number and several of the cooling geometry parameters were varied. The results demonstrate the high local resolution of the method of measurement, which allows improved analytical treatment of the leading-edge cooling configuration. These experiments also point to the necessity of not always performing model tests under idealized conditions. This becomes very clear in the case of the tests performed on an application-oriented impingement-cooling configuration like that often encountered in engine manufacture. In conclusion, as an example, temperature calculations are employed to demonstrate the effect on the cooling effectiveness of varying the distances between insert and inner surface of the leading edge. It shows how the effectiveness of the leading edge cooling can be increased by simple geometrical measures, which results in a considerable improvement in service life.

  1. Analytical prediction of forced convective heat transfer of fluids embedded with nanostructured materials (nanofluids)

    Indian Academy of Sciences (India)

    V Vasu; K Rama Krishna; A C S Kumar

    2007-09-01

    Nanofluids are a new class of heat transfer fluids developed by suspending nanosized solid particles in liquids. Larger thermal conductivity of solid particles compared to the base fluid such as water, ethylene glycol, engine oil etc. significantly enhances their thermal properties. Several phenomenological models have been proposed to explain the anomalous heat transfer enhancement in nanofluids. This paper presents a systematic literature survey to exploit the characteristics of nanofluids, viz., thermal conductivity, specific heat and other thermal properties. An empirical correlation for the thermal conductivity of Al2O3 + water and Cu + water nanofluids, considering the effects of temperature, volume fraction and size of the nanoparticle is developed and presented. A correlation for the evaluation of Nusselt number is also developed and presented and compared in graphical form. This enhanced thermophysical and heat transfer characteristics make fluids embedded with nanomaterials as excellent candidates for future applications.

  2. INTENSITY AND QUALITY IMPROVEMENT OF HARD AND SUPER-HARD MATERIAL SAWING BY TRANSFERRING PLANE CIRCULAR MOTION TO BLANK

    Directory of Open Access Journals (Sweden)

    M. G. Kiselev

    2011-01-01

    Full Text Available The paper considers an experimental evaluation of the influence of a plane periodic circular motion which is transferred to a blank on the intensity of its sawing and quality of its machined surface. Description of a modernized industrial sawing section has been given in the paper. The section is used for sawing various types of specimens (jasper, quartz glass, corundum as under conventional machining conditions so while transferring them a circular motion along a closed path with a shape being like an ellipse. It has been established that in comparison with machining under conventional conditions transfer of such motion to a blank makes it possible significantly (by 2.5-3.9-fold to improve sawing intensity and simultaneously to reduce Ra value of their sawed surfaces by 1.9-3.0-fold. The obtained results have allowed to make a qualitative description of a mechanism which reveals an influence of a blank circular motion on higher intensity of its sawing and quality of the machined surface.

  3. Commercial objectives, technology transfer, and systems analysis for fusion power development

    Science.gov (United States)

    Dean, Stephen O.

    1988-03-01

    Fusion is an essentially inexhaustible source of energy that has the potential for economically attractive commercial applications with excellent safety and environmental characteristics. The primary focus for the fusion-energy development program is the generation of centralstation electricity. Fusion has the potential, however, for many other applications. The fact that a large fraction of the energy released in a DT fusion reaction is carried by high-energy neutrons suggests potentially unique applications. These include breeding of fissile fuels, production of hydrogen and other chemical products, transmutation or “burning” of various nuclear or chemical wastes, radiation processing of materials, production of radioisotopes, food preservation, medical diagnosis and medical treatment, and space power and space propulsion. In addition, fusion R&D will lead to new products and new markets. Each fusion application must meet certain standards of economic and safety and environmental attractiveness. For this reason, economics on the one hand, and safety and environment and licensing on the other hand, are the two primary criteria for setting long-range commercial fusion objectives. A major function of systems analysis is to evaluate the potential of fusion against these objectives and to help guide the fusion R&D program toward practical applications. The transfer of fusion technology and skills from the national laboratories and universities to industry is the key to achieving the long-range objective of commercial fusion applications.

  4. Testing thermocline filler materials and molten-salt heat transfer fluids for thermal energy storage systems used in parabolic trough solar power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Michael James; Hlava, Paul Frank; Brosseau, Douglas A.

    2004-07-01

    Parabolic trough power systems that utilize concentrated solar energy to generate electricity are a proven technology. Industry and laboratory research efforts are now focusing on integration of thermal energy storage as a viable means to enhance dispatchability of concentrated solar energy. One option to significantly reduce costs is to use thermocline storage systems, low-cost filler materials as the primary thermal storage medium, and molten nitrate salts as the direct heat transfer fluid. Prior thermocline evaluations and thermal cycling tests at the Sandia National Laboratories' National Solar Thermal Test Facility identified quartzite rock and silica sand as potential filler materials. An expanded series of isothermal and thermal cycling experiments were planned and implemented to extend those studies in order to demonstrate the durability of these filler materials in molten nitrate salts over a range of operating temperatures for extended timeframes. Upon test completion, careful analyses of filler material samples, as well as the molten salt, were conducted to assess long-term durability and degradation mechanisms in these test conditions. Analysis results demonstrate that the quartzite rock and silica sand appear able to withstand the molten salt environment quite well. No significant deterioration that would impact the performance or operability of a thermocline thermal energy storage system was evident. Therefore, additional studies of the thermocline concept can continue armed with confidence that appropriate filler materials have been identified for the intended application.

  5. Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry

    Directory of Open Access Journals (Sweden)

    Sanju Gupta

    2015-03-01

    Full Text Available Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py–1SO3, 1-pyrenemethylamine salt (Py − Me-NH2 and Pluronic® P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr_LPE are characterized by a combination of analytical (microscopy and spectroscopy techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs namely, monolayer graphene, Gr_LPE (the one prepared with Pluronic® P-123, graphene oxide (GO and its reduced form (rGO on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c [for electron transfer], myoglobin (Mb [for oxygen storage] and horseradish peroxidase (HRP [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET kinetics and attempt to determine the rate constant (kET using two different analytical approaches namely, linear sweep voltammetry and Laviron’s theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical wiring of the redox centers

  6. Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sanju, E-mail: sanju.gupta@wku.edu [Department of Physics and Astronomy, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101-3576 (United States); Biotechnology Center, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101-3576 (United States); Irihamye, Aline [Gatton Academy of Mathematics and Science in Kentucky, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101-3576 (United States)

    2015-03-15

    Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py–1SO{sub 3}), 1-pyrenemethylamine salt (Py − Me-NH{sub 2}) and Pluronic{sup ®} P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr-LPE) are characterized by a combination of analytical (microscopy and spectroscopy) techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs) namely, monolayer graphene, Gr-LPE (the one prepared with Pluronic{sup ®} P-123), graphene oxide (GO) and its reduced form (rGO) on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c) [for electron transfer], myoglobin (Mb) [for oxygen storage] and horseradish peroxidase (HRP) [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET) kinetics and attempt to determine the rate constant (k{sub ET}) using two different analytical approaches namely, linear sweep voltammetry and Laviron’s theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure) upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical

  7. An investigation of using a phase-change material to improve the heat transfer in a small electronic module for an airborne radar application

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1990-10-01

    Finding new and improved means of cooling small electronic packages are of great importance to today's electronic packaging engineer. Thermal absorption through the use of a material which changes phase is an attractive alternative. Taking advantage of the heat capacity of a material's latent heat of fusion is shown to absorb heat away from the electronics, thus decreasing the overall temperature rise of the system. The energy equation is formulated in terms of enthalpy and discretized using a finite-difference method. A FORTRAN program to solve the discretized equations is presented which can be used to analyze heat conduction in a rectangular region undergoing an isothermal phase change. An analysis of heat transfer through a miniature radar electronic module cooled by a phase-change reservoir is presented, illustrating the method's advantages over conventional heat sinks. 41 refs., 11 figs., 2 tabs.

  8. moisture transfer

    Directory of Open Access Journals (Sweden)

    Don Kulasiri

    2005-01-01

    model drying porous materials. Coupled partial differential equations governing the moisture and heat transfer can be solved using numerical techniques, and in this paper we solve them analytically in a setting suitable for industrial drying situations. We discuss the nature of the solutions using the physical properties of Pinus radiata. It is shown that the temperature gradients play a significant role in deciding the moisture profiles within the material when thickness is large and that models based only on moisture potential gradients may not be sufficient to explain the drying phenomena in moist porous materials.

  9. Ultrafast Excited-State Dynamics of Diketopyrrolopyrrole (DPP)-Based Materials: Static versus Diffusion-Controlled Electron Transfer Process

    KAUST Repository

    Alsulami, Qana

    2015-06-25

    Singlet-to-triplet intersystem crossing (ISC) and photoinduced electron transfer (PET) of platinum(II) containing diketopyrrolopyrrole (DPP) oligomer in the absence and presence of strong electron-acceptor tetracyanoethylene (TCNE) were investigated using femtosecond and nanosecond transient absorption spectroscopy with broadband capabilities. The role of platinum(II) incorporation in those photophysical properties was evaluated by comparing the excited-state dynamics of DPP with and without the metal centers. The steady-state measurements reveal that platinum(II) incorporation facilitates dramatically the interactions between DPP-Pt(acac) and TCNE, resulting in charge transfer (CT) complex formation. The transient absorption spectra in the absence of TCNE reveal ultrafast ISC of DPP-Pt(acac) followed by their long-lived triplet state. In the presence of TCNE, PET from the excited DPP-Pt(acac) and DPP to TCNE, forming the radical ion pairs. The ultrafast PET which occurs statically from DPP-Pt(acac) to TCNE in picosecond regime, is much faster than that from DPP to TCNE (nanosecond time scale) which is diffusion-controlled process, providing clear evidence that PET rate is eventually controlled by the platinum(II) incorporation.

  10. Visualization of heat transfer in material for varians of boundary value with Relaxation Iteration Gauss-Seidel method

    Science.gov (United States)

    Basuki, Imam; Cari; Suparmi

    2017-01-01

    The research was aimed to know the effect of initial boundary value to the heat propagation rate pattern using iterations over Gauss-Seidel relaxation method and to analyze the exact value of each node descritization profile of test material. This study was an analytical study to fine analytical an numerical solution. Result from this study is that the pattern of variation of the boundary or initial conditions of a material with regard conductivity value remains at steady state the exact value of the smallest are in the same iteration value. The indicates that the value of the thermal equilibrium tend to be at the same iteration. Result from study showed that the pattern of initial boundary values that causes steady state of heat propagation of test material that has smallest exact similar to the iteration value.

  11. The synergistic effect between effective mass and built-in electric field for the transfer of carriers in nonlinear optical materials.

    Science.gov (United States)

    Li, Mengmeng; Dai, Ying; Ma, Xiangchao; Li, Zhujie; Huang, Baibiao

    2015-07-21

    Recent experiments have demonstrated that the typical nonlinear optical material K3B6O10Br can be an excellent photocatalyst under ultraviolet (UV) light irradiation. To understand the origin of the photocatalytic activity and further improve its photocatalytic efficiency to develop alternative photocatalysts, the built-in electric field and the electron effective mass and their synergistic effect on transfer and the separation of carriers in K3B6O10X (X = Br, Cl) were investigated by means of first-principles calculations. Our results show that the built-in electric field and the smallest effective mass of holes in K3B6O10Br are both along the [001] direction. In contrast, the effective masses of electrons are isotropic because of the spherically symmetric s orbitals at the conduction band minimum (CBM). Therefore, the electric field can promote efficient transfer and separation of the photogenerated carriers along the [001] direction. As a consequence, the synergistic effect of built-in electric field and the isotropy of the electron effective mass results in the {001} surface, to which most of the carriers will accumulate, showing the highest photocatalytic activity. Similar results can also be obtained for a K3B6O10Cl crystal considering the analogous structure with that of K3B6O10Br. The present study may provide theoretical insight to develop the photocatalytic performance of nonlinear optical materials.

  12. Anisotropic electron-transfer mobilities in diethynyl-indenofluorene-dione crystals as high-performance n-type organic semiconductor materials: remarkable enhancement by varying substituents.

    Science.gov (United States)

    Zhang, Xiao-Yu; Huang, Jin-Dou; Yu, Juan-Juan; Li, Peng; Zhang, Wei-Ping; Frauenheim, Thoma

    2015-10-14

    In this study, the electron-transfer properties of alkynylated indenofluorene-diones with various substituents (SiMe3, SiPr3, and SiPh3) that function as n-type organic semiconductors were comparatively investigated at the first-principles DFT level based on the Marcus-Hush theory. The reorganization energies are calculated by the adiabatic potential-energy surface method, and the coupling terms are evaluated through a direct adiabatic model. The maximum value of the electron-transfer mobility of SiPr3 is 0.485 cm(2) V(-1) s(-1), which appears at the orientation angle of the conducting channel on the reference plane a-b near to 172°/352°. The predicted maximum electron mobility value of SiPr3 is nearly 26 times larger than that of SiPh3. This may be attributed to the largest number of intermolecular π-π interactions. In addition, the mobilities in all three crystals show remarkable anisotropic behavior. The calculated results indicate that SiPr3 could be an ideal candidate as a high-performance n-type organic semiconductor material. Our investigations not only give us an opportunity to completely understand the charge transport mechanisms, but also provide guidelines for designing materials for electronic applications.

  13. Transfer of Teaching Materials between Universities: Where Is the Boundary between Legitimate Transaction and Violation of Moral Intellectual Property Rights?

    Science.gov (United States)

    Maiwald, Matthias; Harrington, Kathy

    2012-01-01

    Intellectual property rights have various facets. The best-known one is copyright, enabling the owner to legally utilise intellectual materials. However, there is a separate set of legal entitlements, termed moral intellectual property rights. The purpose of these is to prevent false attribution, damage to an author's reputation and some forms of…

  14. Role of tentacles and protein loading on pore accessibility and mass transfer in cation exchange materials for proteins.

    Science.gov (United States)

    Thomas, Helen; Coquebert de Neuville, Bertrand; Storti, Giuseppe; Morbidelli, Massimo; Joehnck, Matthias; Schulte, Michael

    2013-04-12

    In protein chromatography, the size of the protein determines which fraction of pores it can access within a resin and at which rate of diffusion. Moreover, in the presence of grafted polymers like in advanced materials, adsorbed proteins and electrolytes complicate the interaction pore-protein. In this study, we evaluated in a comparative way the behavior of Fractogel EMD SO3 (M) and (S), "tentacle"-type, strong cation exchangers, as well as a reference material without tentacles, all of which are commonly used for protein purification. ISEC experiments were carried out with a set of Dextran tracers of largely different molecular size covering the typical range of protein sizes. Experimental values of porosity (internal and external to the particles) as well as of pore diffusion coefficients have been measured at different NaCl concentrations and under protein loading. These results provide useful insights into the complex interplay among mentioned factors: first, the presence of tentacles induces size exclusion selectivity in the materials; second, the salt induces conformational changes of the tentacles, leading to porosities larger than expected in tentacle materials; third, protein adsorption mainly leads to a reduction of porosity due to pore space occupied by the protein and to a decrease of pore diffusion coefficient.

  15. Influence of Material Coating on the Heat Transfer in a Layered Cu-SiC-Cu Systems

    Directory of Open Access Journals (Sweden)

    Strojny-Nędza A.

    2017-06-01

    Full Text Available This paper describes the process of obtaining Cu-SiC-Cu systems by way of spark plasma sintering. A monocrystalline form of silicon carbide (6H-SiC type was applied in the experiment. Additionally, silicon carbide samples were covered with a layer of tungsten and molybdenum using chemical vapour deposition (CVD technique. Microstructural examinations and thermal properties measurements were performed. A special attention was put to the metal-ceramic interface. During annealing at a high temperature, copper reacts with silicon carbide. To prevent the decomposition of silicon carbide two types of coating (tungsten and molybdenum were applied. The effect of covering SiC with the aforementioned elements on the composite’s thermal conductivity was analyzed. Results were compared with the numerical modelling of heat transfer in Cu-SiC-Cu systems. Certain possible reasons behind differences in measurements and modelling results were discussed.

  16. Graphene and graphene-like two-denominational materials based fluorescence resonance energy transfer (FRET) assays for biological applications.

    Science.gov (United States)

    Tian, Feng; Lyu, Jing; Shi, Jingyu; Yang, Mo

    2017-03-15

    In the past decades, Förster resonance energy transfer (FRET) has been applied in many biological applications to reveal the biological information at the nanoscale. Recently, graphene and graphene-like two-dimensional (2D) nanomaterials started to be used in FRET assays as donors or acceptors including graphene oxide (GO), graphene quantum dot (GQD), graphitic-carbon nitride nanosheets (g-C3N4) and transition metal dichalcogenides (e.g. MoS2, MnO2, and WS2). Due to the remarkable properties such as large surface to volume ratio, tunable energy band, photoluminescence and excellent biocompatibility, these 2D nanomaterials based FRET assays have shown great potential in various biological applications. This review summarizes the recent development of graphene and graphene-like 2D nanomaterials based FRET assays in applications of biosensing, bioimaging, and drug delivery monitoring.

  17. Effect of superheat, mold, and casting materials on the metal/mold interfacial heat transfer during solidification in graphite-lined permanent molds

    Science.gov (United States)

    Prabhu, K. Narayan; Suresha, K. M.

    2004-10-01

    Heat transfer during the solidification of an Al-Cu-Si alloy (LM4) and commercial pure tin in single steel, graphite, and graphite-lined metallic (composite) molds was investigated. Experiments were carried out at three different superheats. In the case of composite molds, the effect of the thickness of the graphite lining and the outer wall on heat transfer was studied. Temperatures at known locations inside the mold and casting were used to solve the Fourier heat conduction equation inversely to yield the casting/mold interfacial heat flux transients. Increased melt superheats and higher thermal conductivity of the mold material led to an increase in the peak heat flux at the metal/mold interface. Factorial experiments indicated that the mold material had a significant effect on the peak heat flux at the 5% level of significance. The ratio of graphite lining to outer steel wall and superheat had a significant effect on the peak heat flux in significance range varying between 5 and 25%. A heat flux model was proposed to estimate the maximum heat flux transients at different superheat levels of 25 to 75 °C for any metal/mold combinations having a thermal diffusivity ratio (α R) varying between 0.25 and 6.96. The heat flow models could be used to estimate interfacial heat flux transients from the thermophysical properties of the mold and cast materials and the melt superheat. Metallographic analysis indicated finer microstructures for castings poured at increased melt superheats and cast in high-thermal diffusivity molds.

  18. Materials

    Science.gov (United States)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  19. Vapor shielding effects on energy transfer from plasma-gun generated ELM-like transient loads to material surfaces

    Science.gov (United States)

    Kikuchi, Y.; Sakuma, I.; Asai, Y.; Onishi, K.; Isono, W.; Nakazono, T.; Nakane, M.; Fukumoto, N.; Nagata, M.

    2016-02-01

    Energy transfer processes from ELM-like pulsed helium (He) plasmas with a pulse duration of ˜0.1 ms to aluminum (Al) and tungsten (W) surfaces were experimentally investigated by the use of a magnetized coaxial plasma gun device. The surface absorbed energy density of the He pulsed plasma on the W surface measured with a calorimeter was ˜0.44 MJ m-2, whereas it was ˜0.15 MJ m-2 on the Al surface. A vapor layer in front of the Al surface exposed to the He pulsed plasma was clearly identified by Al neutral emission line (Al i) measured with a high time resolution spectrometer, and fast imaging with a high-speed visible camera filtered around the Al i emission line. On the other hand, no clear evaporation in front of the W surface exposed to the He pulsed plasma was observed in the present condition. Discussions on the reduction in the surface absorbed energy density on the Al surface are provided by considering the latent heat of vaporization and radiation cooling due to the Al vapor cloud.

  20. Research of Macroscopic Regularities of Heat and Mass Transfer at the Ignition Condition of a Liquid High-Energy Material by an Immersed Source with a Limited Energy Capacity

    Directory of Open Access Journals (Sweden)

    Dmitrii O. Glushkov

    2014-04-01

    Full Text Available We carried out a numerical and experimental investigation of heat and mass transfer at the ignition condition of a liquid high-energy material by a typical immersed source with a limited energy capacity, being a small, intensely heated metallic particle. The numerical research is made on the basis of a model taking into account a group of interrelated physicochemical processes (thermal conductivity, diffusion, convection, mixing, and radiative heat transfer with phase transitions (evaporation of the liquid and crystallization of the particle's material. We established such terminal conditions for the immersion energy source that prevent inflammation of the high-energy material.

  1. DETERMINATION OF THERMOPHYSICAL PROPERTIES OF FERMENTED WHEAT RAW MATERIALS IN THE STUDY OF PROCESSES OF HEAT- AND MASS TRANSFER

    Directory of Open Access Journals (Sweden)

    A. V. Pribytkov

    2014-01-01

    Full Text Available Summary. The article presents the results of a study of thermophysical properties of fermented wheat raw materials used are described in this experimental method, explained the behavior of graphic curves under different external conditions, given the opportunity to use the results. Possibilities of application of physical characteristics in the design of various designs dryers. Introduced the concept of the fermented wheat feedstock described the appearance of the product and the conditions for its receipt, showing the influence of temperature and moisture on the investigational product. Shows the design of the stand to determine the thermal characteristics of the fermented wheat raw materials using the method of transient thermal regime and describes how it works. Introduced empirical regression equation adequately describe thermal characteristics. Depending on the results of the study are the coefficients of thermal conductivity, specific heat, thermal diffusivity on the moisture content and temperature. The linear dependence shows that with increasing temperature and moisture content of the physical characteristics increase.

  2. Numerical Simulation of the Heat Transfer Behavior of a Zigzag Plate Containing a Phase Change Material for Combustion Heat Recovery and Power Generation

    Directory of Open Access Journals (Sweden)

    Peilun Wang

    2016-01-01

    Full Text Available This study presents a numerical analysis of the melting process of phase change materials (PCMs within a latent heat thermal energy storage (LHTES system employing zigzag plate. The numerical model used NaCl-MgCl2 mixture as PCMs and hot air as heat transfer fluid (HTF. An experimental system was built to validate the model, and the experimental data agrees reasonably well with the simulation results. The simulation results revealed the effects of the Reynolds and Stefan numbers and the surface topography of the zigzag plate on the charging process. Besides, the effect of the relationship between Reynolds and Stefan numbers on the charging process under a new boundary condition employing a fixed input power was studied. It is found that by modifying the shape of the zigzag plate surface it is feasible to enhance the heat transfer of the LHTES unit remarkably. The melting rate of PCMs increases with the value of Ste or Re numbers with only one of them changing; however, the melting rate of PCMs decreases with the increasing Ste (or decreasing Re in a fixed input power condition.

  3. Parameterizing complex reactive force fields using multiple objective evolutionary strategies (MOES): Part 2: transferability of ReaxFF models to C-H-N-O energetic materials.

    Science.gov (United States)

    Rice, Betsy M; Larentzos, James P; Byrd, Edward F C; Weingarten, N Scott

    2015-02-10

    The Multiple Objective Evolutionary Strategies (MOES) algorithm was used to parametrize force fields having the form of the reactive models ReaxFF (van Duin, A. C. T.; Dasgupta, S.; Lorant, F.; Goddard, W. A. J. Phys. Chem. A 2001, 105, 9396) and ReaxFF-lg (Liu, L.; Liu, Y.; Zybin, S. V.; Sun, H.; Goddard, W. A. J. Phys. Chem. A 2011, 115, 11016) in an attempt to produce equal or superior ambient state crystallographic structural results for cyclotrimethylene trinitramine (RDX). Promising candidates were then subjected to molecular dynamics simulations of five other well-known conventional energetic materials to assess the degree of transferability of the models. Two models generated through the MOES search were shown to have performance better than or as good as ReaxFF-lg in describing the six energetic systems modeled. This study shows that MOES is an effective and efficient method to develop complex force fields.

  4. (d,p)-transfer induced fission of heavy radioactive beams

    CERN Document Server

    Veselsky, Martin

    2012-01-01

    (d,p)-transfer induced fission is proposed as a tool to study low energy fission of exotic heavy nuclei. Primary goal is to directly determine the fission barrier height of proton-rich fissile nuclei, preferably using the radio-active beams of isotopes of odd elements, and thus confirm or exclude the low values of fission barrier heights, typically extracted using statistical calculations in the compound nucleus reactions at higher excitation energies. Calculated fission cross sections in transfer reactions of the radioactive beams show sufficient sensitivity to fission barrier height. In the probable case that fission rates will be high enough, mass asymmetry of fission fragments can be determined. Results will be relevant for nuclear astrophysics and for production of super-heavy nuclei. Transfer induced fission offers a possibility for systematic study the low energy fission of heavy exotic nuclei at the ISOLDE.

  5. Enhanced heat transfer through filler-polymer interface by surface-coupling agent in heat-dissipation material: A non-equilibrium molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kouichi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan); Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Kitsunezuka, Masashi; Shinma, Atsushi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan)

    2013-11-21

    Developing a composite material of polymers and micrometer-sized fillers with higher heat conductance is crucial to realize modular packaging of electronic components at higher densities. Enhancement mechanisms of the heat conductance of the polymer-filler interfaces by adding the surface-coupling agent in such a polymer composite material are investigated through the non-equilibrium molecular dynamics (MD) simulation. A simulation system is composed of α-alumina as the filler, bisphenol-A epoxy molecules as the polymers, and model molecules for the surface-coupling agent. The inter-atomic potential between the α-alumina and surface-coupling molecule, which is essential in the present MD simulation, is constructed to reproduce the calculated energies with the electronic density-functional theory. Through the non-equilibrium MD simulation runs, we find that the thermal resistance at the interface decreases significantly by increasing either number or lengths of the surface-coupling molecules and that the effective thermal conductivity of the system approaches to the theoretical value corresponding to zero thermal-resistance at the interface. Detailed analyses about the atomic configurations and local temperatures around the interface are performed to identify heat-transfer routes through the interface.

  6. The status of psychic reality in adolescence. An adult female patient's quasi-adolescent material and the analyst's counter transference response.

    Science.gov (United States)

    Eiguer, A

    1996-12-01

    The author holds that the crisis of adolescence is in fact one of psychic reality, its elements being loss of boundaries, externalisation and the involvement of a third party. In this view, it is essential to conceive of adolescence differently from adulthood, in that, for example, an adolescent's acting out may not be solely a matter of regression but to a considerable extent a consequence of his or her physical development. It is noted that the boundaries between psychic and material reality are fluid throughout life and that adolescents crave identificatory models. The author stresses the importance of the psychic reality of the other in the adolescent's crisis. After considering various views, including those of Freud, on psychic reality and the crises of adolescence, he illustrates his thesis by the clinical example of two adolescent episodes of perversion forming part of an adult female patient's material. In the author's view, these instances of acting out had helped the patient to regain her auto-erotic capacity in the pleasure of fantasy life. He considers that a mutative interpretation must touch upon the primal fantasy and therefore involve the entire person of the analyst in the transference.

  7. The influence of various occlusal materials on stresses transferred to implant-supported prostheses and supporting bone: a three-dimensional finite-element study.

    Science.gov (United States)

    Sevimay, Mujde; Usumez, Aslihan; Eskitascioglu, Gurcan

    2005-04-01

    The aim of this numerical analysis was to evaluate the amount and localization of stress that occurs with various materials used in implant-crown design under functional forces. Computer-aided design techniques and a finite-element stress analysis method were used for evaluation. A 4.1 x 10-mm implant placed in the mandibular second premolar area was simulated and analyzed. Simulation and analysis were performed with the use of COSMOS/M software and Pro/Engineer 2000i on a Dual Pentium III 1-GHz computer. Crown designs were as follows: porcelain fused to noble metal crown, porcelain fused to base metal crown, In-Ceram porcelain crown, and IPS Empress 2 porcelain crown. A 300-N vertical force was applied to the centric relation stop points of the crowns. The results of this study indicated that different types of restorative materials play an important role in the amount and distribution of the stresses in the superstructure and the implant. The highest stress values were observed in the IPS Empress 2 porcelain crown design (600 MPa). Porcelain fused to base metal and In-Ceram framework designs transferred less stress to abutment. Type of restorative materials used in implant crown designs are significant factors in the amount and distribution of the stresses on superstructure and implant under functional forces. Porcelain fused to base metal (149 MPa) and In-Ceram (173 MPa) crown designs induced higher von Mises stress values within the framework than porcelain fused to noble metal (108 MPa) and IPS Empress 2 (119 MPa) porcelain crown designs.

  8. 影响有机热载体炉安全运行的危险因素分析%Analysis on Risk Factors Affecting the Safe Operation of the Organic Heat Transfer Material Heaters

    Institute of Scientific and Technical Information of China (English)

    程明

    2013-01-01

      有机热载体炉具有经济、环保、节能等优点。文章针对有机热载体炉的特点,分析了其在运行时影响安全的危险因素。%organic heat transfer material heaters have economic, environmental protection, energy saving etc. The paper analyzes its risk factors while operating, which affects the safety, to the characteristics of organic heat transfer material heaters.

  9. First Industrial Tests of a Drum Monitor Matrix Correction for the Fissile Mass Measurement in Large Volume Historic Metallic Residues with the Differential Die-away Technique

    Energy Technology Data Exchange (ETDEWEB)

    Antoni, R.; Passard, C.; Perot, B.; Batifol, M.; Vandamme, J.C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 St Paul-lez-Durance, (France); Grassi, G. [AREVA NC, 1 place Jean-Millier, 92084 Paris-La-Defense cedex (France)

    2015-07-01

    The fissile mass in radioactive waste drums filled with compacted metallic residues (spent fuel hulls and nozzles) produced at AREVA La Hague reprocessing plant is measured by neutron interrogation with the Differential Die-away measurement Technique (DDT. In the next years, old hulls and nozzles mixed with Ion-Exchange Resins will be measured. The ion-exchange resins increase neutron moderation in the matrix, compared to the waste measured in the current process. In this context, the Nuclear Measurement Laboratory (NML) of CEA Cadarache has studied a matrix effect correction method, based on a drum monitor ({sup 3}He proportional counter inside the measurement cavity). A previous study performed with the NML R and D measurement cell PROMETHEE 6 has shown the feasibility of method, and the capability of MCNP simulations to correctly reproduce experimental data and to assess the performances of the proposed correction. A next step of the study has focused on the performance assessment of the method on the industrial station using numerical simulation. A correlation between the prompt calibration coefficient of the {sup 239}Pu signal and the drum monitor signal was established using the MCNPX computer code and a fractional factorial experimental design composed of matrix parameters representative of the variation range of historical waste. Calculations have showed that the method allows the assay of the fissile mass with an uncertainty within a factor of 2, while the matrix effect without correction ranges on 2 decades. In this paper, we present and discuss the first experimental tests on the industrial ACC measurement system. A calculation vs. experiment benchmark has been achieved by performing dedicated calibration measurement with a representative drum and {sup 235}U samples. The preliminary comparison between calculation and experiment shows a satisfactory agreement for the drum monitor. The final objective of this work is to confirm the reliability of the

  10. Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Anderson, Mark; Allen, Todd; Corradini, Michael

    2012-01-30

    The goal of this NERI project was to perform research on high temperature fluoride and chloride molten salts towards the long-term goal of using these salts for transferring process heat from high temperature nuclear reactor to operation of hydrogen production and chemical plants. Specifically, the research focuses on corrosion of materials in molten salts, which continues to be one of the most significant challenges in molten salts systems. Based on the earlier work performed at ORNL on salt properties for heat transfer applications, a eutectic fluoride salt FLiNaK (46.5% LiF-11.5%NaF-42.0%KF, mol.%) and a eutectic chloride salt (32%MgCl2-68%KCl, mole %) were selected for this study. Several high temperature candidate Fe-Ni-Cr and Ni-Cr alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, were exposed to molten FLiNaK with the goal of understanding corrosion mechanisms and ranking these alloys for their suitability for molten fluoride salt heat exchanger and thermal storage applications. The tests were performed at 850C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion was noted to occur predominantly from dealloying of Cr from the alloys, an effect that was particularly pronounced at the grain boundaries Alloy weight-loss due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys weight-loss was also found to correlate to the concentration of carbon present for the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. Experiments involving molten salt exposures of Incoloy-800H in Incoloy-800H crucibles under an argon cover gas showed a significantly lower corrosion for this alloy than when tested in a graphite crucible. Graphite significantly accelerated alloy corrosion due to the reduction of Cr from solution by graphite and formation

  11. The study of electromagnetic wave propagation in photonic crystals via planewave based transfer (scattering) matrix method with active gain material applications

    Science.gov (United States)

    Li, Ming

    In this dissertation, a set of numerical simulation tools are developed under previous work to efficiently and accurately study one-dimensional (1D), two-dimensional (2D), 2D slab and three-dimensional (3D) photonic crystal structures and their defects effects by means of spectrum (transmission, reflection, absorption), band structure (dispersion relation), and electric and/or magnetic fields distribution (mode profiles). Further more, the lasing property and spontaneous emission behaviors are studied when active gain materials are presented in the photonic crystal structures. First, the planewave based transfer (scattering) matrix method (TMM) is described in every detail along with a brief review of photonic crystal history (Chapter 1 and 2). As a frequency domain method, TMM has the following major advantages over other numerical methods: (1) the planewave basis makes Maxwell's Equations a linear algebra problem and there are mature numerical package to solve linear algebra problem such as Lapack and Scalapack (for parallel computation). (2) Transfer (scattering) matrix method make 3D problem into 2D slices and link all slices together via the scattering matrix (S matrix) which reduces computation time and memory usage dramatically and makes 3D real photonic crystal devices design possible; and this also makes the simulated domain no length limitation along the propagation direction (ideal for waveguide simulation). (3) It is a frequency domain method and calculation results are all for steady state, without the influences of finite time span convolution effects and/or transient effects. (4) TMM can treat dispersive material (such as metal at visible light) naturally without introducing any additional computation; and meanwhile TMM can also deal with anisotropic material and magnetic material (such as perfectly matched layer) naturally from its algorithms. (5) Extension of TMM to deal with active gain material can be done through an iteration procedure with gain

  12. Experience of air transport of nuclear fuel material in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, T.; Toguri, D. [Transnuclear, LTD. (AREVA group), Tokyo (Japan); Kawasaki, M. [Japan Nuclear Cycle Development Inst., Muramatsu, Ibaraki (Japan)

    2004-07-01

    Certified Reference Materials (hereafter called as to CRMs), which are indispensable for Quality Assurance and Material Accountability in nuclear fuel plants, are being provided by overseas suppliers to Japanese nuclear entities as Type A package (non-fissile) through air transport. However, after the criticality accident at JCO in Japan, special law defining nuclear disaster countermeasures (hereafter called as to the LAW) has been newly enforced in June 2000. Thereafter, nuclear fuel materials must meet not only to the existing transport regulations but also to the LAW for its transport.

  13. Heat Transfer Organic Materials: Robust Polymer Films with the Outstanding Thermal Conductivity Fabricated by the Photopolymerization of Uniaxially Oriented Reactive Discogens.

    Science.gov (United States)

    Kang, Dong-Gue; Park, Minwook; Kim, Dae-Yoon; Goh, Munju; Kim, Namil; Jeong, Kwang-Un

    2016-11-09

    For the development of advanced heat transfer organic materials (HTOMs) with excellent thermal conductivities, triphenylene-based reactive discogens, 2,3,6,7,10,11-hexakis(but-3-enyloxy)triphenylene (HABET) and 4,4',4″,4‴,4'''',4'''''-(triphenylene-2,3,6,7,10,11-hexaylhexakis(oxy))hexakis(butane-1-thiol) (THBT), were synthesized as discotic liquid crystal (DLC) monomers and cross-linkers, respectively. A temperature-composition phase diagram of HABET-THBT mixtures was first established based on their thermal and microscopic analyses. From the experimental results, it was realized that the thermal conductivity of DLC HTOM was strongly affected by the molecular organizations on a macroscopic length scale. Macroscopic orientation of self-assembled columns in DLC HTOMs was effectively achieved under the rotating magnetic fields and successfully stabilized by the photopolymerization. The DLC HTOM polymer-stabilized at the LC phase exhibited the remarkable thermal conductivity above 1 W/mK. When the DLC HTOM was macroscopically oriented, the thermal conductivity was estimated to be 3 W/mK along the in-plane direction of DLC molecule. The outstanding thermal conductivity of DLC HTOM should be originated not only from the high content of two-dimensional aromatic discogens but also from the macroscopically oriented and self-assembled DLC. The newly developed DLC HTOM with an outstanding thermal conductivity as well as with an excellent mechanical sustainability can be applied as directional heat dissipating materials in electronic and display devices.

  14. Advanced research workshop: nuclear materials safety

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, L J; Moshkov, M M

    1999-01-28

    The Advanced Research Workshop (ARW) on Nuclear Materials Safety held June 8-10, 1998, in St. Petersburg, Russia, was attended by 27 Russian experts from 14 different Russian organizations, seven European experts from six different organizations, and 14 U.S. experts from seven different organizations. The ARW was conducted at the State Education Center (SEC), a former Minatom nuclear training center in St. Petersburg. Thirty-three technical presentations were made using simultaneous translations. These presentations are reprinted in this volume as a formal ARW Proceedings in the NATO Science Series. The representative technical papers contained here cover nuclear material safety topics on the storage and disposition of excess plutonium and high enriched uranium (HEU) fissile materials, including vitrification, mixed oxide (MOX) fuel fabrication, plutonium ceramics, reprocessing, geologic disposal, transportation, and Russian regulatory processes. This ARW completed discussions by experts of the nuclear materials safety topics that were not covered in the previous, companion ARW on Nuclear Materials Safety held in Amarillo, Texas, in March 1997. These two workshops, when viewed together as a set, have addressed most nuclear material aspects of the storage and disposition operations required for excess HEU and plutonium. As a result, specific experts in nuclear materials safety have been identified, know each other from their participation in t he two ARW interactions, and have developed a partial consensus and dialogue on the most urgent nuclear materials safety topics to be addressed in a formal bilateral program on t he subject. A strong basis now exists for maintaining and developing a continuing dialogue between Russian, European, and U.S. experts in nuclear materials safety that will improve the safety of future nuclear materials operations in all the countries involved because of t he positive synergistic effects of focusing these diverse backgrounds of

  15. Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Anderson, Mark; Allen, Todd; Corradini, Michael

    2012-01-30

    The goal of this NERI project was to perform research on high temperature fluoride and chloride molten salts towards the long-term goal of using these salts for transferring process heat from high temperature nuclear reactor to operation of hydrogen production and chemical plants. Specifically, the research focuses on corrosion of materials in molten salts, which continues to be one of the most significant challenges in molten salts systems. Based on the earlier work performed at ORNL on salt properties for heat transfer applications, a eutectic fluoride salt FLiNaK (46.5% LiF-11.5%NaF-42.0%KF, mol.%) and a eutectic chloride salt (32%MgCl2-68%KCl, mole %) were selected for this study. Several high temperature candidate Fe-Ni-Cr and Ni-Cr alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, were exposed to molten FLiNaK with the goal of understanding corrosion mechanisms and ranking these alloys for their suitability for molten fluoride salt heat exchanger and thermal storage applications. The tests were performed at 850C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion was noted to occur predominantly from dealloying of Cr from the alloys, an effect that was particularly pronounced at the grain boundaries Alloy weight-loss due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys weight-loss was also found to correlate to the concentration of carbon present for the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. Experiments involving molten salt exposures of Incoloy-800H in Incoloy-800H crucibles under an argon cover gas showed a significantly lower corrosion for this alloy than when tested in a graphite crucible. Graphite significantly accelerated alloy corrosion due to the reduction of Cr from solution by graphite and formation

  16. Coupled calculation of external heat transfer and material temperatures of convection-cooled turbine blades. Final report; Gekoppelte Berechnung des aeusseren Waermeuebergangs und der Materialtemperaturen konvektionsgekuehlter Turbinenschaufeln. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Heselhaus, A.

    1997-05-01

    In this work a hybrid program system consisting of a 3D finite-volume Navier-Stokes flow solver and a 3D finite-element heat conduction solver has been developed. It enables the coupled calculation of structure temperatures in diabatic solid/fluid configurations. The grids of both the finite element and the finite volume computational domain may be completely independent. The coupled program fully resolves the thermal interaction between heat transfer and the resulting material temperatures. The developed coupling algorithm is numerically stable, conservative and works without the need to define ambient temperatures in the flowfield. This allows for the simulation of any solid/fluid configuration. When simulating combined blade/endwall cooling or filmcooling, only a coupled procedure is capable to completely account for the interaction between all relevant thermal parameters. It is found that the coupled calculation of convective cooling in a realistic guide vane leads locally to 45 K higher and 107 K lower blade temperatures than the uncoupled calculation. This shows that accounting for the thermal interaction between the flow and the structure offers both potential to save cooling air and a lower margin of safety when designing cooling systems close to the thermal limits of the blade material. (orig.) [Deutsch] Im Rahmen der vorliegenden Arbeit wurde ein Verfahren zur Berechnung der Temperaturverteilung in diabat umstroemten Koerpern entwickelt, bei dem ein 3D-Finite Volumen Navier-Stokes Stroemungsloeser und ein 3D-Finite Elemente Waermeleitungsloeser zu einem hybriden Programmsystem gekoppelt werden. Dabei besteht die Moeglichkeit, voellig unabhaengige Rechennetze fuer Stroemung und Struktur zu verwenden. Mit dem gekoppelten Verfahren kann die Wechselwirkung zwischen resultierenden Materialtemperaturen und dem davon rueck-beeinflussten Waermeuebergang beruecksichtigt werden. Weiterhin ist der hier entwickelte, stabile und konservative Kopplungsalgorithmus nicht

  17. Measurement of the neutron capture cross section of the fissile isotope $^{235}$U with the CERN n_TOF Total Absorption Calorimeter and a fission tagging based on micromegas detectors

    CERN Document Server

    Mendoza, E; Cano-Ott, D; Guerrero, C; Berthoumieux, E; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Becvár, F; Belloni, F; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Gunsing, F; Gurusamy, P; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kawano, T; Kivel, N; Koehler, P; Kokkoris, M; Korschinek, G; Krticka, M; Kroll, J; Langer, C; Lampoudis, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Martínez, T; Mastinu, P F; Mastromarco, M; Massimi, C; Meaze, M; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondelaers, W; Paradela, C; Pavlik, A; Perkowski, J; Pignatari, M; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Schillebeeckx, P; Schmidt, S; Schumann, D; Stetcu, I; Sabaté, M; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T; Zugec, P

    2014-01-01

    Actual and future nuclear technologies require more accurate nuclear data on the (n, $\\gamma$) cross sections and $\\alpha$-ratios of fissile isotopes. Their measurement presents several difficulties, mainly related to the strong fission $\\gamma$-ray background competing with the weaker $\\gamma$-ray cascades used as the experimental signature of the (n, $\\gamma$) process. A specific setup has been used at the CERN n_TOF facility in 2012 for the measurement of the (n,$\\gamma$ ) cross section and $\\alpha$- ratios of fissile isotopes and used for the case of the $^{235}$U isotope. The setup consists in a set of micromegas fission detectors surrounding $^{235}$U samples and placed inside the segmented BaF$_2$ Total Absorption Calorimeter.

  18. Measurement of the Neutron Capture Cross Section of the Fissile Isotope 235U with the CERN n_TOF Total Absorption Calorimeter and a Fission Tagging Based on Micromegas Detectors

    CERN Document Server

    Balibrea, J; Cano-Ott, D; Guerrero, C; Berthoumieux, E; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Gunsing, F; Gurusamy, P; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kawano, T; Kivel, N; Koehler, P; Kokkoris, M; Korschinek, G; Krtička, M; Kroll, J; Langer, C; Lampoudis, C; Lederer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Martínez, T; Mastinu, P F; Mastromarco, M; Massimi, C; Meaze, M; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondelaers, W; Paradela, C; Pavlik, A; Perkowski, J; Pignatari, M; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Schillebeeckx, P; Schmidt, S; Schumann, D; Stetcu, I; Sabaté, M; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiß, C; Wright, T J; Žugec, P

    Current and future nuclear technologies require more accurate nuclear data on (n,γ) cross sections and the α-ratios of fissile isotopes. Their measurement presents several difficulties, mainly related to the strong fission γ-ray background competing with the weaker γ-ray cascades used as the experimental signature of the (n,γ) process. A specific setup was used at the CERN n_TOF facility in 2012 for the measurement of the (n,γ) cross section and α-ratios of fissile isotopes and used for the case of the 235U isotope. The setup consists of a set of micromegas fission detectors surrounding the 235U samples all placed inside a segmented BaF2 Total Absorption Calorimeter.

  19. The safety of radioactive materials transport; La surete des transports de matieres radioactives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The rule of the radioactive materials transport contains two different objectives: the safety, or physical protection, consists in preventing the losses, the disappearances, the thefts and the diversions of the nuclear materials (useful materials for weapons); the high civil servant of defence near the Minister of Economy, Finance and Industry is the responsible authority; the safety consists in mastering the risks of irradiation, contamination and criticality presented by the radioactive and fissile materials transport, in order that man and environment do not undergo the nuisances. The control of the safety is within the competence of the Asn. (N.C.)

  20. Radionuclide transfer. Radionuklid Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, G.B.

    1993-01-01

    The research project described here had the aim to obtain further information on the transfer of nuclides during pregnancy and lactation. The tests were carried out in mini-pigs and rats receiving unchanging doses of radionuclides with the food. The following findings were revealed for the elements examined: Fe, Se, Cs and Zn were characterized by very high transfer levels in the mother, infant and foetus. A substantial uptake by the mother alone was observed for Co, Ag and Mn. The uptake by the foetus and infant here was 1 to 10 times lower. A preferential concentration in certain tissues was seen for Sr and Tc; the thyroid levels of Tc were about equally high in mothers and infants, while Sr showed less accumulation in the maternal bone. The lanthanide group of substances (Ce, Eu and Gd as well as Y and Ru) were only taken up to a very limited extent. The uptake of the examined radionuclides (Fe, Co, Ag, Ce) with the food ingested was found here to be ten times greater in rats as compared to mini-pigs. This showed that great caution must be observed, if the behaviour of radionuclides in man is extrapolated from relevant data obtained in rodents. (orig./MG)

  1. Programmable Technologies for Micro- and Nano-Scale Pattern and Material Transfer and Possible Applications for Control of Self-Assembly

    Science.gov (United States)

    2003-04-01

    is sometimes a consideration. INFORMATION MATERIAL INFORMATION INFORMATION MATERIAL ENERGY INFORMATION E ATERGY ENERGY MATERIA ,," MATERIAL ENsERGY...50 cm/sec MANY FLOW-GUIDED 25 Few 0lSmm 3 Ise4 MANY THERMAL SPRAY >500 -50 5-50 cm/sec MANY PLASMA SPRAY >500 >5 1_ _ MANY Figure 9. Characteristics

  2. Intelligent nuclear material surveillance system for DUPIC facility

    Energy Technology Data Exchange (ETDEWEB)

    Song, D. Y.; Lee, S. Y.; Ha, J. H.; Go, W. I.; Kim, H. D. [KAERI, Taejon (Korea, Republic of)

    2003-07-01

    DUPIC Fuel Development Facility (DFDF) is the facility to fabricate CANDU-type fuel from spent PWR fuel material without any separation of fissile elements and fission products. Unattended continuous surveillance systems for safeguards of nuclear facility result in large amounts of image and radiation data, which require much time and effort to inspect. Therefore, it is necessary to develop system that automatically pinpoints and diagnoses the anomalies from data. In this regards, this paper presents a novel concept of the continuous surveillance system that integrates visual image and radiation data by the use of neural networks. This surveillance system is operating for safeguards of the DFDF in KAERI.

  3. An examination of electronic file transfer between host and microcomputers for the AMPMODNET/AIMNET (Army Material Plan Modernization Network/Acquisition Information Management Network) classified network environment

    Energy Technology Data Exchange (ETDEWEB)

    Hake, K.A.

    1990-11-01

    This report presents the results of investigation and testing conducted by Oak Ridge National Laboratory (ORNL) for the Project Manager -- Acquisition Information Management (PM-AIM), and the United States Army Materiel Command Headquarters (HQ-AMC). It concerns the establishment of file transfer capabilities on the Army Materiel Plan Modernization (AMPMOD) classified computer system. The discussion provides a general context for micro-to-mainframe connectivity and focuses specifically upon two possible solutions for file transfer capabilities. The second section of this report contains a statement of the problem to be examined, a brief description of the institutional setting of the investigation, and a concise declaration of purpose. The third section lays a conceptual foundation for micro-to-mainframe connectivity and provides a more detailed description of the AMPMOD computing environment. It gives emphasis to the generalized International Business Machines, Inc. (IBM) standard of connectivity because of the predominance of this vendor in the AMPMOD computing environment. The fourth section discusses two test cases as possible solutions for file transfer. The first solution used is the IBM 3270 Control Program telecommunications and terminal emulation software. A version of this software was available on all the IBM Tempest Personal Computer 3s. The second solution used is Distributed Office Support System host electronic mail software with Personal Services/Personal Computer microcomputer e-mail software running with IBM 3270 Workstation Program for terminal emulation. Test conditions and results are presented for both test cases. The fifth section provides a summary of findings for the two possible solutions tested for AMPMOD file transfer. The report concludes with observations on current AMPMOD understanding of file transfer and includes recommendations for future consideration by the sponsor.

  4. Transfer Pricing

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo

    2014-01-01

    Against a background of rather mixed evidence about transfer pricing practices in multinational enterprises (MNEs) and varying attitudes on the part of tax authorities, this paper explores how multiple aims in transfer pricing can be pursued across four different transfer pricing regimes. A MNE h...

  5. Pragmatic Transfer.

    Science.gov (United States)

    Kasper, Gabriele

    1992-01-01

    Attempting to clarify the concept of pragmatic transfer, this article proposes as a basic distinction Leech/Thomas' dichotomy of sociopragmatics versus pragmalinguistics, presenting evidence for transfer at both levels. Issues discussed include pragmatic universals in speech act realization, conditions for pragmatic transfer, communicative…

  6. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  7. Förster resonant energy transfer from an inorganic quantum well to a molecular material: Unexplored aspects, losses, and implications to applications

    Energy Technology Data Exchange (ETDEWEB)

    Itskos, G., E-mail: itskos@ucy.ac.cy [Experimental Condensed Matter Physics Laboratory, Department of Physics, University of Cyprus, Nicosia 1678 (Cyprus); Othonos, A. [Laboratory of Ultrafast Science, Department of Physics, University of Cyprus, Nicosia 1678 (Cyprus); Choulis, S. A. [Molecular Electronics and Photonics Research Unit, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Limassol 3603 (Cyprus); Iliopoulos, E. [Microelectronics Research Group, IESL, FORTH and Physics Department, University of Crete, P.O. Box 1385, 71110 Heraklion-Crete (Greece)

    2015-12-07

    A systematic investigation of Förster resonant energy transfer (FRET) is reported within a hybrid prototype structure based on nitride single quantum well (SQW) donors and light emitting polymer acceptors. Self-consistent Schrödinger-Poisson modeling and steady-state and time-resolved photoluminescence experiments were initially employed to investigate the influence of a wide structural parameter space on the emission quantum yield of the nitride component. The optimized SQW heterostructures were processed into hybrid structures with spin-casted overlayers of polyfluorenes. The influence of important unexplored aspects of the inorganic heterostructure such as SQW confinement, content, and doping on the dipole-dipole coupling was probed. Competing mechanisms to the FRET process associated with interfacial recombination and charge transfer have been studied and their implications to device applications exploiting FRET across heterointerfaces have been discussed.

  8. Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Charles J Werth; Albert J Valocchi, Hongkyu Yoon

    2011-05-21

    Previous studies have found that organic acids, organic bases, and detergent-like chemicals change surface wettability. The wastewater and NAPL mixtures discharged at the Hanford site contain such chemicals, and their proportions likely change over time due to reaction-facilitated aging. The specific objectives of this work were to (1) determine the effect of organic chemical mixtures on surface wettability, (2) determine the effect of organic chemical mixtures on CCl4 volatilization rates from NAPL, and (3) accurately determine the migration, entrapment, and volatilization of organic chemical mixtures. Five tasks were proposed to achieve the project objectives. These are to (1) prepare representative batches of fresh and aged NAPL-wastewater mixtures, (2) to measure interfacial tension, contact angle, and capillary pressure-saturation profiles for the same mixtures, (3) to measure interphase mass transfer rates for the same mixtures using micromodels, (4) to measure multiphase flow and interphase mass transfer in large flow cell experiments, all using the same mixtures, and (5) to modify the multiphase flow simulator STOMP in order to account for updated P-S and interphase mass transfer relationships, and to simulate the impact of CCl4 in the vadose zone on groundwater contamination. Results and findings from these tasks and summarized in the attached final report.

  9. Collection of Digital Audio-visual Material Preservation and Backup Data Transfer%典藏音像资料保存与数字化备份转移

    Institute of Scientific and Technical Information of China (English)

    李浚

    2011-01-01

    According to the audio and video material carrier form, storage media technical features type classification accord- ing to different types of collection, audio-visual materials of corresponding preserving method proposed. In audio and video material carrier storage life could not infinite long cases, and many early video data broadcast devices will be eliminated, causing many valuable audio-visual material will collapse of reality, audio-visual materials need to put forward the urgency views. Finally talk about how video data provide detailed digital transfer methods.%根据音像资料载体形式、存储媒介技术特点进行类型划分,针对不同类型的典藏音像资料提出各种相应的保存方法。在音像资料载体保存期不可能无限长的情况下,以及很多早期音像资料播放设备即将被淘汰,致使许多珍贵声像资料面·临无法使用的现实,为此提出音像资料迫切需要数字化的观点。最后为音像资料怎样数字化转移提供了详细方法

  10. Coupled transfers; Transferts couples

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, X.; Lauriat, G.; Jimenez-Rondan, J. [Universite de Marne-la-Vallee, Lab. d' Etudes des Transferts d' Energie et de Matiere (LETEM), 77 (France); Bouali, H.; Mezrhab, A. [Faculte des Sciences, Dept. de Physique, Lab. de Mecanique et Energetique, Oujda (Morocco); Abid, C. [Ecole Polytechnique Universitaire de Marseille, IUSTI UMR 6595, 13 Marseille (France); Stoian, M.; Rebay, M.; Lachi, M.; Padet, J. [Faculte des Sciences, Lab. de Thermomecanique, UTAP, 51 - Reims (France); Mladin, E.C. [Universitaire Polytechnique Bucarest, Faculte de Genie Mecanique, Bucarest (Romania); Mezrhab, A. [Faculte des Sciences, Lab. de Mecanique et Energetique, Dept. de Physique, Oujda (Morocco); Abid, C.; Papini, F. [Ecole Polytechnique, IUSTI, 13 - Marseille (France); Lorrette, C.; Goyheneche, J.M.; Boechat, C.; Pailler, R. [Laboratoire des Composites ThermoStructuraux, UMR 5801, 33 - Pessac (France); Ben Salah, M.; Askri, F.; Jemni, A.; Ben Nasrallah, S. [Ecole Nationale d' Ingenieurs de Monastir, Lab. d' Etudes des Systemes Thermiques et Energetiques (Tunisia); Grine, A.; Desmons, J.Y.; Harmand, S. [Laboratoire de Mecanique et d' Energetique, 59 - Valenciennes (France); Radenac, E.; Gressier, J.; Millan, P. [ONERA, 31 - Toulouse (France); Giovannini, A. [Institut de Mecanique des Fluides de Toulouse, 31 (France)

    2005-07-01

    emitter: a rational energy use; heat transfers inside glass furnaces - influence of the bath heating parameters on the temperature field; radiant heat transfer and conduction in transient regime in semi-transparent, anisotropic and non-grey environments; about the role of diffusion inside a water droplets spray; modeling of the convective drying of a polymer in aqueous solution; influence of water on the thermal conductivity of carbon/phenolic resin composite materials during pyrolysis; study of the action of vibrations on the birth of thermo-solute convection in a porous environment, with or without gravity; evaporation in hydrophobous porous environment; impact of metallic foams structure on transport properties: morphological measurements and simulation at the pore scale; inertial two-phase flows inside metallic foams. (J.S.)

  11. Transferability of ASTM/NIST alanine-polyethylene recipe at ISS. American Society for Testing and Materials/National Institute for Standards and Technology. Istituto Superiore de Sanita

    Science.gov (United States)

    De Angelis C; Fattibene; Onori; Petetti; Bartolotta; Sansone Santamaria A

    2000-05-01

    Alanine-polyethylene solid state dosimeters were prepared at Istituto Superiore di Sanita (ISS) following the recipe proposed by National Institute of Standards and Technology (NIST) with the goal of testing its transferability. Dosimeters were prepared using 95% alanine and 5% polyethylene, by weight. They are rugged and of increased sensitivity, repeatability and reproducibility as respect to the ISS alanine-paraffin pellets. Reproducibility of about 1% was obtained at 10 Gy and at 3 Gy if one single pellet or a stack of five dosimeters were used, respectively.

  12. Numerical heat transfer studies of the fatty acids for different heat exchanger materials on the performance of a latent heat storage system

    Energy Technology Data Exchange (ETDEWEB)

    Atul Sharma; Lee Dong Won; Jun Un Park [Korea Institute of Energy Research, Daejeon (Korea). Solar Thermal Research Centre; Buddhi, D. [Devi Ahilya University, Indore (India). Thermal Energy Storage Laboratory

    2005-11-01

    Theoretical investigations of fatty acids as a phase change material (PCM) for energy storage system have been conducted in this study. The selected fatty acids were capric acid, lauric acid, myristic acid, palmitic acid and stearic acid. For the two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Glass, stainless steel, tin, aluminium mixed, aluminium and copper were used as heat exchanger materials in the numerical calculations. Theoretical results show that capric acid was found good compatibility with latent heat storage system. The large value of thermal conductivity of heat exchanger materials did not make significant contribution on the melt fraction. (author)

  13. Standard Practices for Simulated Service Testing for Corrosion of Metallic Containment Materials for Use With Heat-Transfer Fluids in Solar Heating and Cooling Systems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1980-01-01

    1.1 These practices cover test procedures simulating field service for evaluating the performance under corrosive conditions of metallic containment materials in solar heating and cooling systems. All test results relate to the performance of the metallic containment material only as a part of a metal/fluid pair. Performance in these test procedures, taken by itself, does not necessarily constitute an adequate basis for acceptance or rejection of a particular metal/fluid pair in solar heating and cooling systems, either in general or in a particular design. 1.2 These practices describe test procedures used to evaluate the resistance to deterioration of metallic containment materials in the several conditions that may occur in operation of solar heating and cooling systems. These conditions include: (1) operating full flow; (2) stagnant empty vented; (3) stagnant, closed to atmosphere, non-draindown; and (4) stagnant, closed to atmosphere, draindown. 1.3 The recommended practices cover the following three te...

  14. Dexter energy transfer pathways.

    Science.gov (United States)

    Skourtis, Spiros S; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M; Beratan, David N

    2016-07-19

    Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor-acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways.

  15. Solar Energy: Heat Transfer.

    Science.gov (United States)

    Knapp, Henry H., III

    This module on heat transfer is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The…

  16. Determination of the fission barrier height in fission of heavy radioactive beams induced by the (d,p)-transfer

    CERN Multimedia

    A theoretical framework is described, allowing to determine the fission barrier height using the observed cross sections of fission induced by the (d,p)-transfer with accuracy, which is not achievable in another type of low-energy fission of neutron-deficient nuclei, the $\\beta$-delayed fission. The primary goal is to directly determine the fission barrier height of proton-rich fissile nuclei, preferably using the radio-active beams of isotopes of odd elements, and thus confirm or exclude the low values of fission barrier heights, typically extracted using statistical calculations in the compound nucleus reactions at higher excitation energies. Calculated fission cross sections in transfer reactions of the radioactive beams show sufficient sensitivity to fission barrier height. In the probable case that fission rates will be high enough, mass asymmetry of fission fragments can be determined. Results will be relevant for nuclear astrophysics and for production of super-heavy nuclei. Transfer induced fission of...

  17. Transfer of aflatoxin B1 and fumonisin B1 from naturally contaminated raw materials to beer during an industrial brewing process.

    Science.gov (United States)

    Pietri, A; Bertuzzi, T; Agosti, B; Donadini, G

    2010-10-01

    The aim of this research was to determine the fate of aflatoxins (AFs) and fumonisins (FBs) naturally occurring in raw materials (maize grit and malted barley) during four industrial brewing processes. The aflatoxin B(1) (AFB(1)) level in raw materials varied from 0.31 to 14.85 microg kg(-1), while the fumonisin B(1) (FB(1)) level (only in maize grit) varied from 1146 to 3194 microg kg(-1). The concentration in finished beer ranged from 0.0015 to 0.022 microg l(-1) for AFB(1) and from 37 to 89 microg l(-1) for FB(1); the other aflatoxins and fumonisin B(2) were not found in beer samples. The average percentage of toxins recovered in finished beer, referring to the amounts contained in raw materials, were 1.5% +/- 0.8% for AFB(1) and 50.7% +/- 4.7% for FB(1). These results were mainly due to the different solubility of the two mycotoxins during the mashing process. If raw materials comply with the limits fixed by European Commission Regulations, the contribution of a moderate daily consumption of beer to AFB(1) and FB(1) intake does not contribute significantly to the exposure of the consumer.

  18. Analysis of Material Transfer From a Soft Workpiece to a Hard Tool: Part II-Experimental Verification of the Proposed Lump Growth Model

    NARCIS (Netherlands)

    Rooij, de M.B.; Schipper, D.J.

    2001-01-01

    In this study, the lump growth model, described in an accompanying paper (de Rooij and Schipper, 2000) is validated by means of experiments performed on a deepdrawing simulator. In the experiments, the influence of material and roughness properties of both sheet and tool on the galling behavior is d

  19. Layer-by-Layer Assembled Films of Perylene Diimide- and Squaraine-Containing Metal-Organic Framework-like Materials: Solar Energy Capture and Directional Energy Transfer

    NARCIS (Netherlands)

    Park, H. J.; So, M. C.; Gosztola, D.; Wiederrecht, G. P.; Emery, J. D.; Martinson, A. B. F.; Er, S.; Wilmer, C. E.; Vermeulen, N. A.; Aspuru-Guzik, A.; Stoddart, J. F.; Farha, O. K.; Hupp, J. T.

    2016-01-01

    We demonstrate that thin films of metal organic framework (MOF)-like materials, containing two perylenedlimides (PDICl4, PDIOPh2) and a squaraine dye (S1); can be fabricated by, layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and

  20. Development of corrosion testing equipment under heat transfer and irradiation conditions to evaluate corrosion resistance of materials used in acid recovery evaporator. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Motooka, Takafumi; Numata, Masami; Kiuchi, Kiyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-01-01

    We have been evaluated the safety for corrosion of various metals applied to acid recovery evaporators by the mock-up tests using small scaled equipment and the reference tests in laboratories with small specimens. These tests have been conducted under-radioactive environment. The environment in practical reprocessing plants has many radioactive species. Therefore, the effect of irradiation on corrosion should be evaluated in detail. In this study, we have developed the corrosion testing equipment, which is employed to simulate environments in the acid recovery evaporators. This report describes the specification of corrosion testing equipment and the results of primary, reference and hot tests. Using the equipment, the corrosion test under heat transfer and irradiation conditions have been carried out for 930 hours in safety. It is expectable that useful corrosion test data in radioactive environment are accumulated with this equipment in future, and help the adequate choice of corrosion test condition in laboratories. (author)

  1. Resin Transfer Molding:A Novel Shaping Process for Composite Materials%树脂传递模塑-复合材料成型新工艺

    Institute of Scientific and Technical Information of China (English)

    马青松; 陈朝辉; 郑文伟; 胡海峰; 肖加余

    2000-01-01

    Resin Transfer Molding(RTM),a novel shaping process with many special advantages for polymer matrix composites has developed very rapidly in recent years. This paper reviewed the procedure and survey of research and application of RTM,and development prospects were introduced at the end.%树脂传递模塑是一种新型的树脂基复合材料成型方法,具有许多独特的优点,近年来发展迅速。本文全面综述了该方法的工艺过程及研究应用概况,介绍了今后进一步发展的方向。

  2. Modeling of the Dynamics of Non-radiative Energy Transfer in Tm3+, Tb3+: LiYF4-Based Electronic Materials

    Science.gov (United States)

    Castañeda-Miranda, A.; Castaño, V. M.

    2017-08-01

    The fluorescent decay of the levels 3H4 and 3F4 of Tm3+ in LiYF4 crystals doped with Tb3+ and Eu3+ was mathematically modeled to estimate the optimal doping levels to maximize the laser emission at 1.5 μm of the transition 3H4 → 3F4. The analysis is carried out both through the solution of the master energy transfer equations that govern the non-radiative processes of energy and Monte Carlo simulations. The analysis is improved with the experimental data of the fluorescence decay to include quadrupole and dipole interactions simultaneously. The importance of considering these interactions is that the optimal concentrations of impurities predicted for these luminescent systems are lower than those reported with the use of traditional models.

  3. Transfer Pricing

    DEFF Research Database (Denmark)

    Rohde, Carsten; Rossing, Christian Plesner

    trade internally as the units have to decide what prices should be paid for such inter-unit transfers. One important challenge is to uncover the consequences that different transfer prices have on the willingness in the organizational units to coordinate activities and trade internally. At the same time...

  4. Quantification of ion or atom transfer phenomena in materials implanted by nuclear methods; Quantification de phenomenes de transferts ioniques ou atomiques dans des materiaux implantes par la mise en oeuvre de methodes nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Oudadesse, Hassane [Clermont-Ferrand-2 Univ., 63 - Aubiere (France)

    1998-05-18

    Knowledge of transfer of the constituents of a system from regions of higher to lower concentration is of interest for implanted bio-materials. It allows determining the rate at which this material is integrated in a living material. To evaluate the ossification kinetics and to study the bio-functionality in corals of Ca and Sr, irradiations with a 10{sup 13} n.cm{sup -2}.s{sup -1} was performed, followed by the examination of changes in the localization of these elements. By using PIXE analysis method the distribution of Ca, P, Sr, Zn and Fe in the implant, bone and bone-implant interfaces were determined. Thus, it was shown that resorption of coral in sheep is achieved in 5 months after implantation and is identical to the cortical tissues 4 months after implantation in animals as for instance in hares. We have analyzed the tissues from around the prostheses extracted from patients. The samples were calcined and reduced to powder weighting some milligrams. We have adopted for this study the PIXE analysis method. The samples were irradiated by a proton beam of 3 MeV and about 400 {mu}m diameter. The results show the presence of the elements Ti, Fe, Cr, Ni or Zn according to the type of the implanted prosthesis. This dispersal of the metallic ions and atoms contaminate the tissues. The transfer factors translate the exchanges between bone and the implanted material. The solvatation phenomenon and the electric charge equilibrium explain the transfer order of cations Mg{sup 2+}, Ca{sup 2+} and Sr{sup 2+} and of the anion PO{sub 4}{sup 3-}. We have also determined these factors for the elements Ti, Cr and Ni. An original technique to study the bone bio-functionality was used. Use of phosphate derivatives labelled by {sup 99m}Tc allows obtaining information about the fixation of radioactive tracer. It was found that only after the eighth month at the implantation the neo-formed bone fixes the MDP (methyl diphosphate) labelled by {sup 99m}Tc in a similar way as in the

  5. 屋顶绿化植物对废弃物转化基质的适应性研究%Study on the Adaptability of Plants for Roof Greening to Base Materials Transferred from Waste

    Institute of Scientific and Technical Information of China (English)

    周媛; 陈法志; 谭庆; 许林; 郭彩霞; 童俊; 戢小梅; 董艳芳

    2011-01-01

    [目的]研究屋顶绿化植物对废弃物转化基质的适应性.[方法]采用正交试验法,进行4因素3水平正交试验,以4种工农业废弃物粉煤灰、煤渣、秸秆和园林废弃物为基质,试验8种景天属植物的适应性情况.[结果]适宜屋顶绿化的废弃物转化基质配方为粉煤灰、煤渣、秸秆、园林废弃物,比例分别为1:1:1:1、1:2:2:2:2:1:2:1;8种景天属植物中佛甲草、垂盆草、宽叶佛甲草、德景天、费菜与八宝景天对废弃物转化基质适应性较强.[结论]废弃物转化基质应用于屋顶绿化中具有广阔的市场前景.%[ Objective ] To study the adaptability of roof greening plants in base materials transferred from waste. [ Method ] By applying the orthogonal test of 4 factors and 3 levels, 4 kinds of industrial and agricultural waste ( fly ash, slag, straw and waste of garden plants) are used to study the adaptability of 8 species of Sedum. [ Result] The proper volume ratio of fly ash, slag, straw and waste of garden plants for making suitable base materials were 1∶1∶ 1∶ 1, 1∶2∶ 2∶2 and 2∶ 1∶2∶ 1. Among the 8 test species, S. lineare, S. sarmentosum Bunge, S. hybridum Immergrunchett, S. aizoon and S. spectable Boreau are of higher adaptability to the base materials transferred from waste. [ Conclusion] The application of waste-transferred base materials enjoys a promising marketing future in roof greening.

  6. New method for simulation of VOC emission from building materials and measurement of mass transfer parameters%建材VOC散发过程模拟与传质参数测定新方法

    Institute of Scientific and Technical Information of China (English)

    宋伟; 孔庆媛; 李洪枚

    2013-01-01

    建材中挥发性有机化合物(VOC)的散发是一个复杂传质过程.为准确把握传质特性,首先建立了一套描述干建材散发行为的显性完全解析模型,适用于模拟对人体最不利的无换气情况;代入有关文献中的传质参数预测了环境舱浓度,与文献中对应的实验数据及数值算法预测值吻合良好.然后基于对模型的分析提出一套简便快捷的实验方法,能够利用不同VOC背景值下干建材在密闭舱中散发的平衡浓度或逐时浓度,求取预测散发过程的4个重要的传质参数:可散发浓度C0、扩散系数D、分配系数K和对流传质系数hm;实验部分测算了两类密度板中甲醛散发的C0、D、K、hm,代入数值算法预测了密闭舱和直流舱的环境舱浓度,与实验数据吻合良好.该套模型和测定方法能够应用于建材散发的模拟研究.%Emission of volatile organic compounds (VOC) from building materials is a complex process of mass transfer. To have a clear picture of mass transfer characteristics, this paper first established an explicitly fully analytical model describing VOC emission behavior from dry building materials, which is applicable to emission simulation in static chamber that is most unfavorable to human health. The VOC concentration in the chamber predicted based on the mass transfer parameters in literature is in good agreement with corresponding experimental data and numerical calculation in literature. Based on this model, an experimental method is proposed for convenient, rapid and simultaneous measurement of four important mass transfer parameters for VOC emission prediction (emittable concentration C0, diffusion coefficient D, partition coefficient K and convection mass transfer coefficient hm) by making use of emission equilibrium or process concentration in a static chamber at a series of background concentrations. With the values of C0, D, K and hm for formaldehyde emission mass transfer obtained

  7. Impact of cementitious materials decalcification on transfer properties: application to radioactive waste deep repository; Influence de la decalcification de materiaux cimentaires sur les proprietes de transfert: application au stockage profond de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Perlot, C

    2005-09-15

    Cementitious materials have been selected to compose the engineering barrier system (EBS) of the French radioactive waste deep repository, because of concrete physico-chemical properties: the hydrates of the cementitious matrix and the pH of the pore solution contribute to radionuclides retention; furthermore the compactness of these materials limits elements transport. The confinement capacity of the system has to be assessed while a period at least equivalent to waste activity (up to 100.000 years). His durability was sustained by the evolution of transfer properties in accordance with cementitious materials decalcification, alteration that expresses structure long-term behavior. Then, two degradation modes were carried out, taking into account the different physical and chemical solicitations imposed by the host formation. The first mode, a static one, was an accelerated decalcification test using nitrate ammonium solution. It replicates the EBS alteration dues to underground water. Degradation kinetic was estimated by the amount of calcium leached and the measurement of the calcium hydroxide dissolution front. To evaluate the decalcification impact, samples were characterized before and after degradation in term of microstructure (porosity, pores size distribution) and of transfer properties (diffusivity, gas and water permeability). The influence of cement nature (ordinary Portland cement, blended cement) and aggregates type (lime or siliceous) was observed: experiments were repeated on different mortars mixes. On this occasion, an essential reflection on this test metrology was led. The second mode, a dynamical degradation, was performed with an environmental permeameter. It recreates the EBS solicitations ensured during the re-saturation period, distinguished by the hydraulic pressure imposed by the geologic layer and the waste exothermicity. This apparatus, based on triaxial cell functioning, allows applying on samples pressure drop between 2 and 10 MPa and

  8. "Transfer Shock" or "Transfer Ecstasy?"

    Science.gov (United States)

    Nickens, John M.

    The alleged characteristic drop in grade point average (GPA) of transfer students and the subsequent rise in GPA was investigated in this study. No statistically significant difference was found in first term junior year GPA between junior college transfers and native Florida State University students after the variance accounted for by the…

  9. 脂肪酸类相变材料传热及液相渗漏的研究进展%Review on heat transfer and liquid phase leakage of fatty acids phase change materials

    Institute of Scientific and Technical Information of China (English)

    黄雪; 崔英德; 张步宁; 冯光炷; 尹国强

    2014-01-01

    能源的大量消耗使得储热技术研究越来越重要,相变材料作为一种有效的潜热储热材料在潜热储热系统中占据重要地位。脂肪酸相变材料因其来源广泛,具有共熔和共结晶特点、相变焓高和清洁可再生等优点受到广泛关注,但脂肪酸相变材料也存在热导率低和固-液相转变时液相渗漏等缺点。本文对国内外脂肪酸相变材料的传热和渗漏进行了综述与讨论,就热导率低的缺点提出了强化传热的方式,通过建立传热模型研究其导热行为并预测传热系数;就渗漏问题提出4种有效解决液相渗漏的方法,分析了各种方法的优缺点。对节能环保要求越来越高的今天,解决脂肪酸相变材料的传热和渗漏已成为热点问题。最后对脂肪酸相变材料的发展前景进行展望。%With increasing energy consumption,energy storage techniques are becoming more and more important. The phase change materials (PCM),which are efficient latent heat thermal storage materials,play an important role in the latent heat thermal storage system. Fatty acids PCM because of its rich resources,characteristics of eutectic and cocrystallization,large latent heat,cleanness and renewableness have attracted extensive attention. However , poor heat conductivity , leakage in solid-liquid phase change are the disadvantages. In this paper,fatty acids PCM heat transfer and leakage are reviewed and heat transfer enhancement to resolve the shortcoming of low thermal conductivity is discussed. A thermal heat transfer model is established and the behavior of heat transfer is predicted,and coefficient on leakage issues raised. Four solutions of liquid leakage are proposed and their advantages and disadvantages are analyzed. The prospects of fatty acids PCM are presented.

  10. Synthesis, crystal growth and characterization of bioactive material: 2-amino-1H-benzo[d]imidazol-3-ium salicylate single crystal-a proton transfer molecular complex

    Science.gov (United States)

    Fathima, K. Saiadali; Anitha, K.

    2017-05-01

    The 1:1 molecular adducts 2-aminobenzimidazolium salicylate (ABIS) single crystal was synthesized and grown from 2-aminobenzimidazole (ABI) as a donor and salicylic acid (SA) as an acceptor. The cell parameter was determined using single crystal X-Ray diffraction method and the complex ABIS belongs to monoclinic system. The spectroscopic studies showed that ABIS crystal was an ion pair complex. The FTIR and Raman spectra showed that the presence of O-H, C=N, C=O vibration which confirms the proton transfer from SA to ABI. The UV-Vis spectrum exhibited a visible band at 359nm for ABIS due to the salicylate anion of the molecule. Further the antimicrobial activity of ABIS complex against Staphylococcus aureus, klebsiella pneumonia, Pseudomonas eruginos and E.coli pathogens was investigated. So the complex molecule inhibits both Gram positive and Gram negative bacterial. It is found that benzimidazole with aminogroup at position 2 increases the general antimicrobial activities of ABIS crystal.

  11. Influence factors for induced airflow of bulk materials in chute transfer station%溜槽转运过程中落料诱导气流的影响因素

    Institute of Scientific and Technical Information of China (English)

    李小川; 王启立; 刘颀; 李强; 罗会清; 胡亚非; 杨豪

    2015-01-01

    Induced airflow caused by falling bulk materials in chute transportation process was the chief cause of dust fugitive. In order to explore the main influence factors for induced airflow in chute transfer station, the inclination angleγ, diameterD and lengthL of the circular chute, the mass flow rate of materialmp, the induced airflow velocityug and the effective induced air flowQ were studied. The conclusions are as follows: Induced flow is effected by the chute inclination angleγ from two aspects of energy transformation and material arrangement, and with theγ increasing, the induced airflow velocityug increases, but for the chute of different lengths, theug increases as theγ increases with different increasing trend. The exponent ofug-γ curve increases with the increase inL. In chute transfer process, the induced airflow velocity is dropped by reducing the dispersity of material of falling process and reducing the contact area of material with each other. For the 110 mm diameter chute, the power index of fitting curve withug andL is about 0.64. An important factor of the formation of the effective flow or occurring the "back mixing phenomenon" of the induced airflow is the chute diameterD. Choosing the fit chute diameter can strengthen the capacity of dust carrying of the induced airflow. Chute transfer process improves the proportion of core zone material of the flowing material, so that it makes the increase speed ofug slow down with the increase ofmp, and 0.15th power is proportional toug andmp.%溜槽转运过程中产生的诱导气流是散料输送过程扬尘的主要诱因,本文作者通过研究圆形溜槽的倾角 γ和直径D、溜槽长度L、物料的质量流量mp及有效诱导气流量Q等参数对诱导气流速度ug的影响,分析影响溜槽转运诱导气流的主要因素.结果表明:溜槽倾角γ从能量转化和物料排布两方面影响诱导气流,诱导气流速度ug随γ增大而增大,但不同L的溜槽,ug随γ增大而

  12. Summary Report for Concentrating Solar Power Thermal Storage Workshop: New Concepts and Materials for Thermal Energy Storage and Heat-Transfer Fluids, May 20, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, G.

    2011-08-01

    This document summarizes a workshop on thermal energy storage for concentrating solar power (CSP) that was held in Golden, Colorado, on May 20, 2011. The event was hosted by the U.S. Department of Energy (DOE), the National Renewable Energy Laboratory, and Sandia National Laboratories. The objective was to engage the university and laboratory research communities to identify and define research directions for developing new high-temperature materials and systems that advance thermal energy storage for CSP technologies. This workshop was motivated, in part, by the DOE SunShot Initiative, which sets a very aggressive cost goal for CSP technologies -- a levelized cost of energy of 6 cents per kilowatt-hour by 2020 with no incentives or credits.

  13. The Study of Electromagnetic Wave Propogation in Photonic Crystals Via Planewave Based Transfer (Scattering) Matrix Method with Active Gain Material Applications

    Energy Technology Data Exchange (ETDEWEB)

    LI, Ming [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    In this dissertation, a set of numerical simulation tools are developed under previous work to efficiently and accurately study one-dimensional (1D), two-dimensional(2D), 2D slab and three-dimensional (3D) photonic crystal structures and their defects effects by means of spectrum (transmission, reflection, absorption), band structure (dispersion relation), and electric and/or magnetic fields distribution (mode profiles). Furthermore, the lasing property and spontaneous emission behaviors are studied when active gain materials are presented in the photonic crystal structures. Various physical properties such as resonant cavity quality factor, waveguide loss, propagation group velocity of electromagnetic wave and light-current curve (for lasing devices) can be obtained from the developed software package.

  14. Intramolecular charge transfer and Z-scan studies of a semiorganic nonlinear optical material sodium acid phthalate hemihydrate: a vibrational spectroscopic study.

    Science.gov (United States)

    Sajan, D; Vijayan, N; Safakath, K; Philip, Reji; Joe, I Hubert

    2011-07-28

    FT-IR and Raman spectra of the nonlinear optical material sodium acid phthalate hemihydrate crystal have been recorded and analyzed. The equilibrium geometry, bonding features, and harmonic vibrational wavenumbers have been investigated with the help of the B3LYP density functional theory method. A detailed interpretation of the vibrational spectra was carried out with the aid of normal coordinate analysis following the scaled quantum mechanical force field methodology. The natural bond orbital analysis confirms the occurrence of strong intermolecular hydrogen bonding in the molecule. Nonlinear optical absorption of the sample has been studied at 532 nm using single 5 ns laser pulses, employing the open-aperture Z-scan technique. It is found that the NaAPH molecule is a potential candidate for optical limiting applications. © 2011 American Chemical Society

  15. Optimizing the position of insulating materials in flat roofs exposed to sunshine to gain minimum heat into buildings under periodic heat transfer conditions.

    Science.gov (United States)

    Shaik, Saboor; Talanki, Ashok Babu Puttranga Setty

    2016-05-01

    Building roofs are responsible for the huge heat gain in buildings. In the present work, an analysis of the influence of insulation location inside a flat roof exposed directly to the sun's radiation was performed to reduce heat gain in buildings. The unsteady thermal response parameters of the building roof such as admittance, transmittance, decrement factor, and time lags have been investigated by solving a one-dimensional diffusion equation under convective periodic boundary conditions. Theoretical results of four types of walls were compared with the experimental results available in literature. The results reveal that the roof with insulation placed at the outer side and at the center plane of the roof is the most energy efficient from the lower decrement factor point of view and the roof with insulation placed at the center plane and the inner side of the roof is the best from the highest time lag point of view among the seven studied configurations. The composite roof with expanded polystyrene insulation located at the outer side and at the center plane of the roof is found to be the best roof from the lowest decrement factor (0.130) point of view, and the composite roof with resin-bonded mineral wool insulation located at the center plane and at the inner side of the roof is found to be energy efficient from the highest time lag point (9.33 h) of view among the seven configurations with five different insulation materials studied. The optimum fabric energy storage thicknesses of reinforced cement concrete, expanded polystyrene, foam glass, rock wool, rice husk, resin-bonded mineral wool, and cement plaster were computed. From the results, it is concluded that rock wool has the least optimum fabric energy storage thickness (0.114 m) among the seven studied building roof materials.

  16. Performance Testing of Molten Regolith Electrolysis with Transfer of Molten Material for the Production of Oxygen and Metals on the Moon

    Science.gov (United States)

    Sibille, Laurent; Sadoway, Donald; Tripathy, Prabhat; Standish, Evan; Sirk, Aislinn; Melendez, Orlando; Stefanescu, Doru

    2010-01-01

    Previously, we have demonstrated the production of oxygen by electrolysis of molten regolith simulants at temperatures near 1600 C. Using an inert anode and suitable cathode, direct electrolysis (no supporting electrolyte) of the molten silicate is carried out, resulting in the production of molten metallic products at the cathode and oxygen gas at the anode. Initial direct measurements of current efficiency have confirmed that the process offer potential advantages of high oxygen production rates in a smaller footprint facility landed on the moon, with a minimum of consumables brought from Earth. We now report the results of a scale-up effort toward the goal of achieving production rates equivalent to 1 metric ton O2/year, a benchmark established for the support of a lunar base. We previously reported on the electrochemical behavior of the molten electrolyte as dependent on anode material, sweep rate and electrolyte composition in batches of 20-200g and at currents of less than 0.5 A. In this paper, we present the results of experiments performed at currents up to 10 Amperes) and in larger volumes of regolith simulant (500 g - 1 kg) for longer durations of electrolysis. The technical development of critical design components is described, including: inert anodes capable of passing continuous currents of several Amperes, container materials selection, direct gas analysis capability to determine the gas components co-evolving with oxygen. To allow a continuous process, a system has been designed and tested to enable the withdrawal of cathodically-reduced molten metals and spent molten oxide electrolyte. The performance of the withdrawal system is presented and critiqued. The design of the electrolytic cell and the configuration of the furnace were supported by modeling the thermal environment of the system in an effort to realize a balance between external heating and internal joule heating. We will discuss the impact these simulations and experimental findings have

  17. Energy storage and heat transfer characteristics of ground heat exchanger with phase change backfill materials%相变材料回填地埋管换热器蓄能传热特性

    Institute of Scientific and Technical Information of China (English)

    杨卫波; 孙露露; 吴晅

    2014-01-01

    points for the application of GSHP. In this paper, a new type of GHE with phase change backfill materials was presented to change its thermal response characteristics and heat transfer performance. Theoretically, the thermal interference radius of soil can be reduced by the phase change of phase change materials (PCM), and the energy storage performance of GHE can be improved due to the release of phase change latent heat. In order to further investigate the influences of solid-liquid phase change of phase change backfill materials on energy storage and heat transfer performance of GHE, a quasi-three dimensional heat transfer model with phase change was developed for the vertical U-bend GHE, which couples the one-dimensional fluid heat transfer in vertical direction with the two-dimensional soil transient heat transfer in level. The model was discreted by the control volume method and solved by the apparent heat capacity method. Based on the numerical solution of the model, the influences of solid-liquid phase change of PCM on energy storage performance of GHE and thermal response characteristics of soil temperature around GHE were analyzed for winter and summer mode respectively. The effects of phase change temperature and phase change latent heat of PCM on the thermal diffusivity and energy storage characteristics of GHE were discussed. The results indicate that under same conditions, the soil temperature variations trend is slow down and the thermal interference region is reduced due to the heat extraction and release during the phase change of PCM. The heat exchange performance of GHE can be evidently improved by backfilling materials with low and high phase change temperature for summer and winter respectively. At the same time, the energy storage performance can be enhanced by grouting the materials with large latent heat. The study is significant for releasing the thermal interference region of soil and improving the energy storage and heat transfer performance of

  18. Characterization of dynamic thermal control schemes and heat transfer pathways for incorporating variable emissivity electrochromic materials into a space suit heat rejection system

    Science.gov (United States)

    Massina, Christopher James

    The feasibility of conducting long duration human spaceflight missions is largely dependent on the provision of consumables such as oxygen, water, and food. In addition to meeting crew metabolic needs, water sublimation has long served as the primary heat rejection mechanism in space suits during extravehicular activity (EVA). During a single eight hour EVA, approximately 3.6 kg (8 lbm) of water is lost from the current suit. Reducing the amount of expended water during EVA is a long standing goal of space suit life support systems designers; but to date, no alternate thermal control mechanism has demonstrated the ability to completely eliminate the loss. One proposed concept is to convert the majority of a space suit's surface area into a radiator such that the local environment can be used as a radiative thermal sink for rejecting heat without mass loss. Due to natural variations in both internal (metabolic) loads and external (environmental) sink temperatures, radiative transport must be actively modulated in order to maintain an acceptable thermal balance. Here, variable emissivity electrochromic devices are examined as the primary mechanism for enabling variable heat rejection. This dissertation focuses on theoretical and empirical evaluations performed to determine the feasibility of using a full suit, variable emissivity radiator architecture for space suit thermal control. Operational envelopes are described that show where a given environment and/or metabolic load combination may or may not be supported by the evaluated thermal architecture. Key integration considerations and guidelines include determining allowable thermal environments, defining skin-to-radiator heat transfer properties, and evaluating required electrochromic performance properties. Analysis also considered the impacts of dynamic environmental changes and the architecture's extensibility to EVA on the Martian surface. At the conclusion of this work, the full suit, variable emissivity

  19. Technology Transfer and Commercialization

    Science.gov (United States)

    Martin, Katherine; Chapman, Diane; Giffith, Melanie; Molnar, Darwin

    2001-01-01

    During concurrent sessions for Materials and Structures for High Performance and Emissions Reduction, the UEET Intellectual Property Officer and the Technology Commercialization Specialist will discuss the UEET Technology Transfer and Commercialization goals and efforts. This will include a review of the Technology Commercialization Plan for UEET and what UEET personnel are asked to do to further the goals of the Plan. The major goal of the Plan is to define methods for how UEET assets can best be infused into industry. The National Technology Transfer Center will conduct a summary of its efforts in assessing UEET technologies in the areas of materials and emissions reduction for commercial potential. NTTC is assisting us in completing an inventory and prioritization by commercialization potential. This will result in increased exposure of UEET capabilities to the private sector. The session will include audience solicitation of additional commercializable technologies.

  20. Multiscale conformal pattern transfer

    Science.gov (United States)

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-06-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics.

  1. Technology Transfer and Commercialization

    Science.gov (United States)

    Martin, Katherine; Chapman, Diane; Giffith, Melanie; Molnar, Darwin

    2001-01-01

    During concurrent sessions for Materials and Structures for High Performance and Emissions Reduction, the UEET Intellectual Property Officer and the Technology Commercialization Specialist will discuss the UEET Technology Transfer and Commercialization goals and efforts. This will include a review of the Technology Commercialization Plan for UEET and what UEET personnel are asked to do to further the goals of the Plan. The major goal of the Plan is to define methods for how UEET assets can best be infused into industry. The National Technology Transfer Center will conduct a summary of its efforts in assessing UEET technologies in the areas of materials and emissions reduction for commercial potential. NTTC is assisting us in completing an inventory and prioritization by commercialization potential. This will result in increased exposure of UEET capabilities to the private sector. The session will include audience solicitation of additional commercializable technologies.

  2. Technology Transfer

    Science.gov (United States)

    Smith, Nanette R.

    1995-01-01

    The objective of this summer's work was to attempt to enhance Technology Application Group (TAG) ability to measure the outcomes of its efforts to transfer NASA technology. By reviewing existing literature, by explaining the economic principles involved in evaluating the economic impact of technology transfer, and by investigating the LaRC processes our William & Mary team has been able to lead this important discussion. In reviewing the existing literature, we identified many of the metrics that are currently being used in the area of technology transfer. Learning about the LaRC technology transfer processes and the metrics currently used to track the transfer process enabled us to compare other R&D facilities to LaRC. We discuss and diagram impacts of technology transfer in the short run and the long run. Significantly, it serves as the basis for analysis and provides guidance in thinking about what the measurement objectives ought to be. By focusing on the SBIR Program, valuable information regarding the strengths and weaknesses of this LaRC program are to be gained. A survey was developed to ask probing questions regarding SBIR contractors' experience with the program. Specifically we are interested in finding out whether the SBIR Program is accomplishing its mission, if the SBIR companies are providing the needed innovations specified by NASA and to what extent those innovations have led to commercial success. We also developed a survey to ask COTR's, who are NASA employees acting as technical advisors to the SBIR contractors, the same type of questions, evaluating the successes and problems with the SBIR Program as they see it. This survey was developed to be implemented interactively on computer. It is our hope that the statistical and econometric studies that can be done on the data collected from all of these sources will provide insight regarding the direction to take in developing systematic evaluations of programs like the SBIR Program so that they can

  3. Blastocyst Transfer

    OpenAIRE

    sprotocols

    2014-01-01

    ### Method: Blastocyst transfer is usually performed 24 hours after aggregation when the morulae have become expanded blastocysts and on the same day as injection. A little time is given between injection and transfer to allow blastocysts to re-expand. **The Recipient** Careful selection of the recipient is most important as the pups are the end result of a lot of hard work. Two strains of mice are used:RB Swiss and (CBA*C57BL6/J)f1. RB Swiss are quiet and make excellent mothers ...

  4. Heat transfer

    CERN Document Server

    Holman, J P

    2010-01-01

    As one of the most popular heat transfer texts, Jack Holman's "Heat Transfer" is noted for its clarity, accessible approach, and inclusion of many examples and problem sets. The new tenth edition retains the straight-forward, to-the-point writing style while covering both analytical and empirical approaches to the subject. Throughout the book, emphasis is placed on physical understanding while, at the same time, relying on meaningful experimental data in those situations that do not permit a simple analytical solution. New examples and templates provide students with updated resources for computer-numerical solutions.

  5. Quasi-white light emission involving Förster resonance energy transfer in a new organic inorganic tin chloride based material (AMPS)[SnCl6]H2O

    Science.gov (United States)

    Dammak, Thameur; Abid, Younes

    2017-04-01

    This work deals with optical properties of a new organic inorganic material: 3, 3‧-Diaminodiphenyl-sulfone tin chloride with the formula (C12H14N2O2S)[SnCl6]H2O abbreviated as (AMPS)[SnCl6]H2O. Single crystals of (AMPS)[SnCl6]H2O were elaborated by the solvent evaporation method and investigated by X-ray diffraction, optical absorption (OA), photoluminescence (PL) and photoluminescence excitation (PLE). The crystal structure is composed of discrete [SnCl6] anions surrounded by organic (AMPS) cations and H2O molecules. For optical investigations, thin films have been prepared by spin-coating method from the ethanol solution of the material. Photoluminescence measurements show a quasi-white light and intense emission which can be observed even with naked eye at room temperature. This emission is believed to be due to excitonic recombination involving a Förster resonance energy transfer mechanism in which (AMPS) molecule acts as a donor and [SnCl6] molecule acts as an acceptor. Moreover, the temperature dependence study of the photoluminescence in term of Varshni and Arrhenius models reveals the free character of the inorganic exciton and shows that the organic exciton is rather localized.

  6. 颗粒材料余热回收系统中传热系数的确定%Determination of Heat Transfer Coefficient in Waste Heat Recovery System of Granular Material

    Institute of Scientific and Technical Information of China (English)

    顾永敏; 戴苏明

    2012-01-01

    固体颗粒状的陶粒在生产过程中存在着丰富的余热资源,但回收系统中传热系数的确定比流体工质的更为复杂。基于某陶粒生产企业节能项目的研发,对颗粒材料余热回收系统中传热系数的确定进行了探讨。研究结果比较符合设计预期,对颗粒材料余热回收技术具有工程指导价值。%Rich waste heat exists in the manufacturing process of solid granular ceramsite. But it is much more complex to determine heat transfer coefficient of a solid heat recovery system than liquid working medium. Combined with the research of a ceramic enterprise' s energy-saving project, studies are carried out to determine the heat trans- fer coefficient of granular material waste heat recovery system. The results roughly satisfy the anticipated design and have practical engineering value for the developing of the waste heat recovery technology of granular material.

  7. Advanced Materials Technology

    Science.gov (United States)

    Blankenship, C. P. (Compiler); Teichman, L. A. (Compiler)

    1982-01-01

    Composites, polymer science, metallic materials (aluminum, titanium, and superalloys), materials processing technology, materials durability in the aerospace environment, ceramics, fatigue and fracture mechanics, tribology, and nondestructive evaluation (NDE) are discussed. Research and development activities are introduced to the nonaerospace industry. In order to provide a convenient means to help transfer aerospace technology to the commercial mainstream in a systematic manner.

  8. Transfer Timing

    OpenAIRE

    2003-01-01

    sim present Simulation Presentation Interactive Media Element This IME is used in the Computer Communications and Networks class offered in the Graduate School of Operations and Information Sciences. This introductory computer networking course provides the theory and principles of networking and communications protocols. This IME is used to help students understand data transfer options. CS3502 Computer Communications and Networks

  9. Sophisticated transfer

    NARCIS (Netherlands)

    Reinhart, T.

    2006-01-01

    On the eve of the Iraq war, fears were expressed in different circles that under the cover of war, Israel may attempt a transfer of Palestinians in the “seam line” area of the northern West Bank (Kalkilya, Tulkarem). Last week, the army produced a scene from this scenario. On April 2 at 3 AM, a larg

  10. Geo energy research and development: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Traeger, R.K.

    1982-03-01

    Sandia Geo Energy Programs related to geothermal, coal, oil and gas, and synfuel resources have provided a useful mechanism for transferring laboratory technologies to private industry. Significant transfer of hardware, computer programs, diagnostics and instrumentation, advanced materials, and in situ process understanding has occurred through US/DOE supported programs in the past five years. The text briefly reviews the technology transfer procedures and summarizes 32 items that have been transferred and another 20 technologies that are now being considered for possible transfer to industry. A major factor in successful transfer has been personal interactions between Sandia engineers and the technical staff from private industry during all aspects of the technology development.

  11. Influence of materials with high thermal conductivity on heat transfer of regenerative chamber%高热导率材料对蓄热室传热的影响

    Institute of Scientific and Technical Information of China (English)

    刘慧; 李亚冰; 陈文仲

    2012-01-01

    The regenerative high temperature air combustion technology was used to instead of square hole type pottery clay heat exchanger in traditional tower zinc distillation furnace. Parts of the materials in regenerative chamber were improved. Heat resistant steel balls with high thermal conductivity were used to replace some heat retainers. The temperature distribution and the power change of the improved regenerative chamber were numerically simulated. Results show that the uniformity of temperature distribution in regenerative chamber is obviously improved,and the heat transfer effect at the end of regenerative chamber is increased. The high temperature zone transfers to tail area, which is effectively used,and preheating temperature of air is dramatically increased.%采用蓄热式高温空气燃烧技术代替传统塔式锌精馏炉方孔式陶土换热器技术,并对蓄热室的部分材料进行改进.用热导率较高的耐热钢小球代替部分蓄热体,并采用数值模拟对改进后的蓄热室温度分布及功率的变化进行考查.结果表明,蓄热室内温度分布的均匀性明显提高,尾部蓄热室传热效果增强.高温段向尾部偏移,有效利用了蓄热室的尾部区域,且预热空气温度得到显著提高.

  12. Integrated Performance Testing Workshop - Supplemental Materials (Scripts and Procedures)

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Gregory A.

    2014-02-01

    A variety of performance tests are described relating to: Material Transfers; Emergency Evacuation; Alarm Response Assessment; and an Enhanced Limited Scope Performance Test (ELSPT). Procedures are given for: nuclear material physical inventory and discrepancy; material transfers; and emergency evacuation.

  13. Transfer functions

    Science.gov (United States)

    Taback, I.

    1979-01-01

    The vulnerability of electronic equipment to carbon fibers is studied. The effectiveness of interfaces, such as filters, doors, window screens, and cabinets, which affect the concentration, exposure, or deposition of carbon fibers on both (internal and external) sides of the interface is examined. The transfer function of multilayer aluminum mesh, wet and dry, polyurethane foam, and window screen are determined as a function of air velocity. FIlters installed in typical traffic control boxes and air conditioners are also considered.

  14. Lunar Materials Handling System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of bulk materials and products into and out of process equipment in support of lunar and Mars in...

  15. Development and implementation of a new pneumatic transfer system for materials irradiation at IEA-R1 reactor; Desenvolvimento e implementacao de um novo sistema pneumatico de transferencia para irradiacao de materiais no reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Alberto de Jesus

    2011-07-01

    Pneumatic Transfer Systems (PTS) are classified as mechanical equipment largely operated all over the world for transport of a huge sort of objects, samples and materials located at nearly terminals or even at separated ones. System applicability is often recognized in many activities, such as medicine (hospital settings, clinical analysis labs), industry (steel, automobiles, mining, chemical, food, construction), trading (gas station, movies, supermarkets, banks, e-commerce) and federal agencies (post services, federal courts, public enterprises). In the nuclear settings, PTS shows also a vast array of applications, being a part of radioisotope production, as well as short-lived radiopharmaceuticals, including 67 Ga, 201 Tl, 18 F and 123 I-ultra pure. Besides, PTS are also used at radioactive waste management plants and research institutes that apply neutron activation analysis (NAA). This work was directed toward the design and operation of a new PTS for the IEA-R1 nuclear research reactor settled at Instituto de Pesquisas Energeticas e Nucleares (IPEN) for NAA application. With this aim, it was calculated the charge of reactor core grid plate and sample transport testing. Neutron flux at irradiating position was determined as 3,70 {+-} 0,26 10{sup 12} n cm{sup -2} s{sup -1}. (author)

  16. Accelerating fissile fuel breeding in FBR with natural safety features%加速增产核燃料的天然安全“核热泉”快中子增殖堆

    Institute of Scientific and Technical Information of China (English)

    吕应中

    2012-01-01

    为保证21世纪中国经济的持续稳定地高速增长,必须充分发挥核能的巨大潜力,使之配合其他可再生能源同步增长,及早大规模替代煤炭等化石能源.由于目前国内大量兴建的核电站以压水堆为主,需要消费大量天然铀资源,倚靠廉价铀供应难于维持长期增长,必须依靠快中子增殖生产人造裂变燃料——钚,才能摆脱天然铀原料短缺的束缚.然而,传统的快中子增殖堆的核燃料增产速度较慢,难于配合中国核电的高速增长.本文介绍一种先进快中于增殖堆(AFBR)方案,其中利用在线连续换料的空心球形燃料元件,依靠载热剂的出人口之间的温度差实现满功率自然循环,可以成倍地提高燃料比功率与核燃料增殖速度.本快中子增殖堆改进了俄罗斯称为“天然安全”的BREST铅冷快堆设计方案,成为无须人为控制的“核热泉”,它能在不设置加压泵及高位铅池的情况下,自动按外部负荷需要供应必要的热量,完全依靠自然循环将全部裂变热能及停堆后堆芯余热散出,不至对环境产生放射性污染.%To guarantee the rapid growth of the Chinese economy in 21" century, nuclear energy should be fully exploited, together with other renewable energies to replace coal and other depletive fossil fuels. Unfortunately, the major Chinese nuclear power plants under construction are mostly PWRs that would consume a lot of natural uranium during their operations. The availability of cheap natural uranium could seriously constraint the Chinese nuclear power development, unless artificial fissile fuel-plutonium is supplied from fast breeder reactors. The fissile nuclei production rate in the traditional fast breeders, however, seems too slow to match the rapid growth of nuclear power. A concept of the advanced fast breeder (AFBR) is introduced, therefore, to greatly accelerating the fissile fuel breeding process. In said breeder, the spherical hollow

  17. Heat transfer

    CERN Document Server

    Jorge, Kubie; Thomas, Grassie

    2012-01-01

    A core task of engineers is to analyse energy related problems. The analytical treatment is usually based on principles of thermodynamics, fluid mechanics and heat transfer, but is increasingly being handled computationally.This unique resource presents a practical textbook, written for both undergraduates and professionals, with a series of over 60 computer workbooks on an accompanying CD.The book emphasizes how complex problems can be deconstructed into a series of simple steps. All thermophysical property computations are illustrated using diagrams within text and on the compani

  18. LIFE Materials: Overview of Fuels and Structural Materials Issues Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J

    2008-09-08

    The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spent nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission

  19. Preparation and heat transfer enhancement performance of eutectic mixture of fatty acids as phase change material%脂肪酸低熔混合物的制备及强化传热研究

    Institute of Scientific and Technical Information of China (English)

    包艳华; 王庭慰

    2011-01-01

    利用差示扫描最热仪测定了羊蜡酸-棕榈酸二元混合物的热性能,确定其低熔混合物配比,并采用激光导热仪分析了添加微米级导热填料对提高该低熔混合物作为相变材料(PCM)的导热性的效果.结果表明,将20质量份数的改性sic粉加人100份PCM中,其导热率增加100%且相容性较好.而添加同量的α-Al2O3粉和玻璃粉,其导热率分别提高66%和44%.DSC热性能分析表明,填料的使用会使PCM的熔点增加3~5℃,但随着添加量的增加熔点基本保持不变,而熔融焓则会随着添加剂量的增加而递减.以上结果表明,对导热率提高效果最明显的是改性SiC粉.%The thennal property of euteclic mixture of capric-palmitic acid as phase change material ( PCM) is determined by the method of differential scanning calorimeter( DSC) . The heat transfer enhancement performance of the eutectic mixture is investigated by the method of laser thermal conductivity device, using thermal conducting fillers like modified caborundum ( SiC) powder, alumina ( α-Al2O3) powder or glass dust. The results show that Lhe thermal conductivity of the PCM increases hy 2. 0 times with adding 20 mass fraction of modified SiC powder, while with the same addition of α-Al2O3 powder or glass dust, the conductivity increases hy 1 . 66 or I . 44 , respectively. The thermal analysis indicates that the addition of additives increases the melting temperature to nearly a constant value,while the fusion enthalpy deceases with the increase of the addition of additives. The best result of heat transfer enhancement performance is observed when modified caborundum powder is used as additive.

  20. Zirconium carbonitride pellets by internal sol gel and spark plasma sintering as inert matrix fuel material

    Science.gov (United States)

    Hedberg, Marcus; Cologna, Marco; Cambriani, Andrea; Somers, Joseph; Ekberg, Christian

    2016-10-01

    Inert matrix fuel is a fuel type where the fissile material is blended with a solid diluent material. In this work zirconium carbonitride microspheres have been produced by internal sol gel technique, followed by carbothermal reduction. Material nitride purities in the produced materials ranged from Zr(N0.45C0.55) to Zr(N0.74C0.26) as determined by X-ray diffraction and application of Vegard's law. The zirconium carbonitride microspheres have been pelletized by spark plasma sintering (SPS) and by conventional cold pressing and sintering. In all SPS experiments cohesive pellets were formed. Maximum final density reached by SPS at 1700 °C was 87% theoretical density (TD) compared to 53% TD in conventional sintering at 1700 °C. Pore sizes in all the produced pellets were in the μm scale and no density gradients could be observed by computer tomography.

  1. The first stage of BFS integrated system for nuclear materials control and accounting. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    The BFS computerized accounting system is a network-based one. It runs in a client/server mode. The equipment used in the system includes a computer network consisting of: One server computer system, including peripheral hardware and three client computer systems. The server is located near the control room of the BFS-2 facility outside of the `stone sack` to ensure access during operation of the critical assemblies. Two of the client computer systems are located near the assembly tables of the BFS-1 and BFS-2 facilities while the third one being the Fissile Material Storage. This final report details the following topics: Computerized nuclear material accounting methods; The portal monitoring system; Test and evaluation of item control technology; Test and evaluation of radiation based nuclear material measurement equipment; and The integrated demonstration of nuclear material control and accounting methods.

  2. DYNAMIC HEAT TRANSFER OF BRICK WALL FILLED WITH PHASE CHANGE MATERIALS (PCM) UNDER FLUCTUATING TEMPERATURES%交变温度作用下填充PCM砖墙的动态传热特性

    Institute of Scientific and Technical Information of China (English)

    吴梁玉; 陈永平; 张程宾; 施明恒

    2012-01-01

    采用enthalpy-porosity法建立交变温度作用下填充相变材料(PCM)的砖墙内伴有熔化和凝固相变过程的动态传热模型并进行数值计算,比较实心砖墙与PCM砖墙的室内侧壁温响应变化,分析讨论墙体中PCM填充份额和PCM填充空间分布对墙体动态传热过程的影响,并对填充PCM墙体结构进行性能评价.研究结果表明,填充PCM的砖墙结构由于其孔隙中填充的PCM通过熔化/凝固相变作用蓄存了潜热,有效削弱了外界温度变化对室内壁温的影响,对室内温度起到削峰填谷的作用.随着砖墙中填充PCM份额的增加,室内侧温度的波动幅度明显减小,且对室外交变温度作用的滞后效果也相应得到增强.对于相同的PCM填充份额,PCM的填充分布方式对砖墙的保温性能和温度滞后效果也存在一定影响,但影响并不明显.%A model for thermal conduction accompanied with solidification and melting processes was developed by enthalpy-porosity technique and numerically analyzed to investigate the dynamic heat transfer characteristics of the brick wall filled with Phase Change Materials (PCM). The dynamic heat transfer characteristic, which is represented by inside wall surface temperature response, of brick wall filled with PCM was evaluated and compared with that of solid brick wall. The effects of PCM amount as well as spatial distribution of PCM on the dynamic heat transfer characteristic of the brick wall were investigated and discussed. It is indicated that the influence of outdoor temperature fluctuation on indoor temperature is weaken due to the filling of PCM, which can store latent heat via solidification or melting processes. In addition, with the increasing filling amount of PCM, the fluctuation of inside wall surface temperature is obviously smoothed. Correspondingly, the hysteresis in response to the outdoor temperature fluctuation is enhanced. However, unlike the PCM amount, the spatial distribution of PCM

  3. La política social y la recomposición material del consenso: la centralidad de los programas de Transferencia de Renta Condicionada: el caso argentino Social policy and the material reform of the agreement: the central character of the programs of Conditioned Income Transfer: the Argentinian case

    Directory of Open Access Journals (Sweden)

    Silvia Fernández Soto

    2013-03-01

    Full Text Available En el marco de una estrategia global de recomposición material del consenso, analizamos el programa de Transferencia de Renta Condicionada, Asignación Universal por hijo para protección social (AUH en Argentina. Desde una perspectiva amplia y compleja de análisis de la política social, identificamos problemas en relación a la orientación y sentido ético político que persigue, en un contexto de disputa de las perspectivas de protección social. Analizamos algunas tensiones centrales: la relación de las condiciones y formas de organización del trabajo y las desigualdades contemporáneas con las formas de protección social; el papel de las condicionalidades y las tensiones con perspectivas universalistas.In the context of an overall strategy of material reform of the agreement, we have analyzed the program of Conditioned Income Transfer, Universal Allocation per Child for social protection (AUH - Asignación Universal per hijo in Argentina. From a broad and complex analysis of the social policy, we have identified problems related to the orientation and political ethical sense in a disputing context of the perspectives of social protection. We have analyzed some central tensions: the relationship between the conditions and forms of work organization and inequalities and the contemporary forms of social protection; the role of conditions and tensions and the universal perspective.

  4. Les transitions énergétiques urbaines du XIXe au XXIe siècle : de la biomasse aux combustibles fossiles et fissiles à Paris (France).

    OpenAIRE

    Kim, Eun Hye

    2013-01-01

    Increasing urban natural resource consumption and particularly fossil energy consumption is one of the important factors of global environment alteration. To understand the socioecological transition process for the city, we characterize it as a natral resource dependant system in material and ecological terms. Cities rnobilize a technical system to draw the external natural resource. Therefore, externality is a fundamental character of urban metabolism. We focus in this work on the relations...

  5. Assessment of fissionable material behaviour in fission chambers

    Energy Technology Data Exchange (ETDEWEB)

    Cabellos, O., E-mail: oscar.cabellos@upm.e [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Department of Nuclear Engineering, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Fernandez, P. [Department of Nuclear Engineering, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Rapisarda, D. [Laboratorio Nacional de Fusion, EURATOM-CIEMAT, 28040 Madrid (Spain); Garcia-Herranz, N. [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, 28006 Madrid (Spain); Department of Nuclear Engineering, Universidad Politecnica de Madrid, 28006 Madrid (Spain)

    2010-06-21

    A comprehensive study is performed in order to assess the pertinence of fission chambers coated with different fissile materials for high neutron flux detection. Three neutron scenarios are proposed to study the fast component of a high neutron flux: (i) high neutron flux with a significant thermal contribution such as BR2, (ii) DEMO magnetic fusion reactor, and (iii) IFMIF high flux test module. In this study, the inventory code ACAB is used to analyze the following questions: (i) impact of different deposits in fission chambers; (ii) effect of the irradiation time/burn-up on the concentration; (iii) impact of activation cross-section uncertainties on the composition of the deposit for all the range of burn-up/irradiation neutron fluences of interest. The complete set of nuclear data (decay, fission yield, activation cross-sections, and uncertainties) provided in the EAF2007 data library are used for this evaluation.

  6. Nucleate boiling heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Saiz Jabardo, J.M. [Universidade da Coruna (Spain). Escola Politecnica Superior], e-mail: mjabardo@cdf.udc.es

    2009-07-01

    Nucleate boiling heat transfer has been intensely studied during the last 70 years. However boiling remains a science to be understood and equated. In other words, using the definition given by Boulding, it is an 'insecure science'. It would be pretentious of the part of the author to explore all the nuances that the title of the paper suggests in a single conference paper. Instead the paper will focus on one interesting aspect such as the effect of the surface microstructure on nucleate boiling heat transfer. A summary of a chronological literature survey is done followed by an analysis of the results of an experimental investigation of boiling on tubes of different materials and surface roughness. The effect of the surface roughness is performed through data from the boiling of refrigerants R-134a and R-123, medium and low pressure refrigerants, respectively. In order to investigate the extent to which the surface roughness affects boiling heat transfer, very rough surfaces (4.6 {mu}m and 10.5 {mu}m ) have been tested. Though most of the data confirm previous literature trends, the very rough surfaces present a peculiar behaviour with respect to that of the smoother surfaces (Ra<3.0 {mu}m). (author)

  7. LIFE Materials: Overview of Fuels and Structural Materials Issues Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J

    2008-09-08

    The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spent nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission

  8. Long Term Transfer Effect of Metaphoric Allusion.

    Science.gov (United States)

    Hayes, David A.; Mateja, John A.

    A study was conducted to investigate the long term transfer effect of metaphoric allusion used to clarify unfamiliar subject matter. Forty-nine high school students were given unfamiliar prose materials variously augmented by metaphoric allusion. The subjects' immediate performance on a transfer task was compared to their performance on an…

  9. Heat-transfer data for hydrogen

    Science.gov (United States)

    Mc Carthy, J. R.; Miller, W. S.; Okuda, A. S.; Seader, J. D.

    1970-01-01

    Information is given regarding experimental heat-transfer data compiled for the turbulent flow of hydrogen within straight, electrically heated, round cross section tubes. Tube materials, test conditions, parameters studied, and generalized conclusions are presented.

  10. Development of Neutron Probes for Characterization of Hazardous Materials in the Sub-surface Medium

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, Raymond Patrick; McGrath, Christopher Andrew; Lopez, Juan Carlos

    2002-08-01

    Neutron probes are being developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the detection, identification and quantification of hazardous materials in the ground. Such materials include plutonium, uranium, americium, chlorine and fluorine. Both a Neutron Gamma (NG) probe and a Prompt Fission Neutron (PFN) probe are being developed. The NG probe is used primarily for nuclide identification and quantification measurements. The PFN is used mostly for the detection and measurement of fissile material, but also for the determination of thermal neutron macroscopic absorption cross sections of the various elements comprising the ground matrix. Calibration of these probes will be carried out at the INEEL using an indoor facility that has been designed for this activity.

  11. Development of Neutron Probes for Characterization of Hazardous Materials in the Sub-surface Medium

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, R.P.; McGrath, C.A.; Lopez, J.C.

    2002-05-15

    Neutron probes are being developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the detection, identification and quantification of hazardous materials in the ground. Such materials include plutonium, uranium, americium, chlorine and fluorine. Both a Neutron Gamma (NG) probe and a Prompt Fission Neutron (PFN) probe are being developed. The NG probe is used primarily for nuclide identification and quantification measurements. The PFN is used mostly for the detection and measurement of fissile material, but also for the determination of thermal neutron macroscopic absorption cross sections of the various elements comprising the ground matrix. Calibration of these probes will be carried out at the INEEL using an indoor facility that has been designed for this activity.

  12. 高温熔融盐壳管式相变换热器的传热特性%Heat Transfer Performances of High-Temperature Shell-Tube Heat Exchanger with Molten-Salt Phase Change Materials

    Institute of Scientific and Technical Information of China (English)

    左远志; 杨晓西; 丁静

    2011-01-01

    建立了高温熔融盐壳管式相变换热器的同心套管模型.采用Fluent软件,分析了在考虑相变区域自然对流条件下,熔融盐流体与相变材料的物性参数、内管进口温度与进口流向等因素对液相率与熔化时间的影响,并在熔融盐传热-蓄热实验平台上进行了试验研究.发现:考虑相变区域自然对流时,总的熔化时间减少16.2%;模拟得到的壳侧相变材料温度随时间的变化趋势与实验结果趋于一致.结果表明,可采用熔融盐相变区域特殊测点温度超过相变材料的熔点,并升至与内管流体进口温度相近时所耗费的时间作为壳管式相变换热器内相变材料完全熔化的判据.%In this paper, first, a concentric circular tube model for the shell-tube heat exchanger with molten-salt phase change materials (PCMs) is established. Then, the liquid fraction and the total melting time, which are affected by the thermal-physical parameters of the molten salt fluid and the PCMs as well as by the inlet velocity and the flow direction of the inner tube, are analyzed with Fluent, by taking into consideration the natural convection in the PCMs region. Finally, some experiments are carried out on a test platform of molten-salt heat transfer. The resuits show that the total melting time nearly decreases by 16. 2% considering the natural convection in the PCMs region, and that the simulated temperature of PCMs at the shell side varies with time,which has a tendency similar to that of the experimental results. Thus, it comes to the conclusion that, when the temperature of the specific measuring point in the PCMs region exceeds the melting point of PCMs and rises to the tube inlet temperature, the correspending time cost can be used as the criterion of melting ending of PCMs.

  13. Alternative technical summary report for immobilized disposition in deep boreholes: Immobilized disposal of plutonium in coated ceramic pellets in grout without canisters, Version 4.0. Fissile materials disposition program

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, A.M.

    1996-08-23

    This paper summarizes and compares the immobilized and direct borehole disposition alternatives previously presented in the alternative technical summary. The important design concepts, facility features and operational procedures are first briefly described. This is followed by a discussion of the issues that affect the evaluation of each alternative against the programmatic assessment criteria that have been established for selecting the preferred alternatives for plutonium disposition.

  14. Characterization of DWPF recycle condensate tank materials

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-01

    A Defense Waste Processing Facility (DWPF) Recycle Condensate Tank (RCT) sample was delivered to the Savannah River National Laboratory (SRNL) for characterization with particular interest in the concentration of I-129, U-233, U-235, total U, and total Pu. Since a portion of Salt Batch 8 will contain DWPF recycle materials, the concentration of I-129 is important to undertand for salt batch planning purposes. The chemical and physical characterizations are also needed as input to the interpretation of future work aimed at determining the propensity of the RCT material to foam, and methods to remediate any foaming potential. According to DWPF the Tank Farm 2H evaporator has experienced foaming while processing DWPF recycle materials. The characterization work on the RCT samples has been completed and is reported here. The composition of the Sludge Batch 8 (SB8) RCT material is largely a low base solution of 0.2M NaNO2 and 0.1M NaNO3 with a small amount of formate present. Insoluble solids comprise only 0.05 wt.% of the slurry. The solids appear to be largely sludge-like solids based on elemental composition and SEM-EDS analysis. The sample contains an elevated concentration of I-129 (38x) and substantial 59% fraction of Tc-99, as compared to the incoming SB8 Tank 40 feed material. The Hg concentration is 5x, when compared to Fe, of that expected based on sludge carryover. The total U and Pu concentrations are reduced significantly, 0.536 wt.% TS and 2.42E-03 wt.% TS, respectively, with the fissile components, U-233, U-235, Pu-239, and Pu-241, an order of magnitude lower in concentration than those in the SB8 Tank 40 DWPF feed material. This report will be revised to include the foaming study requested in the TTR and outlined in the TTQAP when that work is concluded.

  15. Technology transfer by multinationals

    OpenAIRE

    Kostyantyn Zuzik

    2003-01-01

    The paper analyses the issue of technology transfer by multinational corporations. The following questions are explored: (a) world market of technologies, the role of MNCs (b) Choice of the technology transfer mode, Dunning's OLI-theory as a factor of the choice of the mode of transfer (c) measurement and profitability of technology transfer (d) transfer of technology through partnerships, JVs, alliances and through M&As (e) aspects of technology transfer by services multinationals. Paper uti...

  16. Technology transfer by multinationals

    OpenAIRE

    2003-01-01

    The paper analyses the issue of technology transfer by multinational corporations. The following questions are explored: (a) world market of technologies, the role of MNCs (b) Choice of the technology transfer mode, Dunning's OLI-theory as a factor of the choice of the mode of transfer (c) measurement and profitability of technology transfer (d) transfer of technology through partnerships, JVs, alliances and through M&As (e) aspects of technology transfer by services multinationals. Paper uti...

  17. Boiling heat transfer modern developments and advances

    CERN Document Server

    Lahey, Jr, RT

    2013-01-01

    This volume covers the modern developments in boiling heat transfer and two-phase flow, and is intended to provide industrial, government and academic researchers with state-of-the-art research findings in the area of multiphase flow and heat transfer technology. Special attention is given to technology transfer, indicating how recent significant results may be used for practical applications. The chapters give detailed technical material that will be useful to engineers and scientists who work in the field of multiphase flow and heat transfer. The authors of all chapters are members of the

  18. 10 CFR 74.15 - Nuclear material transaction reports.

    Science.gov (United States)

    2010-01-01

    ... for transfers and receipts, shall submit a Nuclear Material Transaction Report, in computer-readable.... Each licensee who transfers the material shall submit a Nuclear Material Transaction Report in computer.... Each licensee who receives the material shall submit a Nuclear Material Transaction Report in...

  19. Contrast Materials

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Contrast Materials What are contrast materials and how do they ... material? Pregnancy and contrast materials What are contrast materials and how do they work? Contrast materials, also ...

  20. Heat Transfer Basics and Practice

    CERN Document Server

    Böckh, Peter

    2012-01-01

    The book provides an easy way to understand the fundamentals of heat transfer. The reader will acquire the ability to design and analyze heat exchangers. Without extensive derivation of the fundamentals, the latest correlations for heat transfer coefficients and their application are discussed. The following topics are presented - Steady state and transient heat conduction - Free and forced convection - Finned surfaces - Condensation and boiling - Radiation - Heat exchanger design - Problem-solving After introducing the basic terminology, the reader is made familiar with the different mechanisms of heat transfer. Their practical application is demonstrated in examples, which are available in the Internet as MathCad files for further use. Tables of material properties and formulas for their use in programs are included in the appendix. This book will serve as a valuable resource for both students and engineers in the industry. The author’s experience indicates that students, after 40 lectures and exercises ...

  1. Energy transfer and downconversion near-infrared material of Tb{sup 3+} and Yb{sup 3+} doped Ca{sub 5}(BO{sub 3}){sub 3}F

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Dejian; Li, Jin-Yan [School of Metallurgy and Chemistry Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China); Lin, Huihong, E-mail: linhh@hstc.edu.cn [School of Chemical and Environmental Engineering, Hanshan Normal University, Chaozhou 521041, Guangdong (China); Zhang, Jingxiang [School of Chemical and Environmental Engineering, Hanshan Normal University, Chaozhou 521041, Guangdong (China)

    2016-11-01

    Yb{sup 3+} and Tb{sup 3+} singly doped and Tb{sup 3+}–Yb{sup 3+} co-doped Ca{sub 5}(BO{sub 3}){sub 3}F phosphors were prepared by a solid state reaction method. The luminescence emission and excitation spectra as well as the luminescence decay curves were investigated. The emission bands of Yb{sup 3+} ion are located around 1000 nm, matching well with the optimal response of Si-based solar cells. Tb{sup 3+} can be a sensitizer for Yb{sup 3+} in the host. The energy transfer from Tb{sup 3+} to Yb{sup 3+} was investigated, the energy transfer mechanism was proposed as cooperative energy transfer. Tb{sup 3+} concentration dependent quantum efficiency was calculated and the maximum efficiency approached 115.5%.

  2. A Delayed Neutron Counting System for the Analysis of Special Nuclear Materials

    Science.gov (United States)

    Sellers, Madison Theresa

    Nuclear forensic analysis is a modem science that uses numerous analytical techniques to identify and attribute nuclear materials in the event of a nuclear explosion, radiological terrorist attack or the interception of illicit nuclear material smuggling. The Canadian Department of National Defence has participated in recent international exercises that have highlighted the Nation's requirement to develop nuclear forensics expertise, protocol and capabilities, specifically pertaining to the analysis of special nuclear materials (SNM). A delayed neutron counting (DNC) system has been designed and established at the Royal Military College of Canada (RMC) to enhance the Government's SNM analysis capabilities. This analytical technique complements those already at RMC by providing a rapid and non-destructive method for the analysis of the fissile isotopes of both uranium (U) and plutonium (Pu). The SLOWPOKE-2 reactor at RMC produces a predominately thermal neutron flux. These neutrons induce fission in the SNM isotopes 233U, 235U and 239Pu releasing prompt fast neutrons, energy and radioactive fission fragments. Some of these fission fragments undergo beta - decay and subsequently emit neutrons, which can be recorded by an array of sensitive 3He detectors. The significant time period between the fission process and the release of these neutrons results in their identification as 'delayed neutrons'. The recorded neutron spectrum varies with time and the count rate curve is unique to each fissile isotope. In-house software, developed by this project, can analyze this delayed neutron curve and provides the fissile mass in the sample. Extensive characterization of the DNC system has been performed with natural U samples with 235 U content ranging from 2--7 microg. The system efficiency and dead time behaviour determined by the natural uranium sample analyses were validated by depleted uranium samples with similar quantities of 235 U resulting in a typical relative error of

  3. Boiling Heat Transfer in Circulating Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    张利斌; 李修伦

    2001-01-01

    A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39 mm ID and 2.0 m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum.The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data.

  4. Boiling Heat Transfer in Circulating Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39mm ID and 2.0m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum. The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data.

  5. Modeling ozone mass transfer in reclaimed wastewater.

    Science.gov (United States)

    Jiang, Pan; Chen, Hsiao-Ting; Babcock, Roger W; Stenstrom, Michael K

    2009-01-01

    Ozone mass transfer in reclaimed water was evaluated at pilot scale to determine mass-transfer characteristics and reaction kinetics and to assess the use of oxygen as a surrogate to measure this process. Tests were conducted in a 40-L/min pilot plant over a 3-year period. Nonsteady-state mass-transfer analyses for both oxygen and ozone were performed for superficial gas flow rates ranging from 0.13m/min to 0.40m/min. The psi factor, which is the ratio of volumetric mass-transfer coefficients of ozone to oxygen, was determined. The decrease in oxygen transfer rate caused by contaminants in reclaimed water was only 10 to 15% compared to tap water. A simple mathematical model was developed to describe transfer rate and steady state ozone concentration. Ozone decay was modeled accurately as a pseudo first-order reaction between ozone and ozone-demanding materials.

  6. Mechanics in Composite Materials and Process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae Gil

    1993-03-15

    This book includes introduction of composite materials, stress, in-plane stiffness of laminates strain rate, ply stress, failure criterion and bending, composite materials micromechanics, composite plates and micromechanics of composite materials. It also deals with process of composite materials such as autoclave vacuum bag degassing process, connection of composite materials, filament winding process, resin transfer molding, sheet molding compound and compression molding.

  7. Novel Scintillating Materials Based on Phenyl-Polysiloxane for Neutron Detection and Monitoring

    CERN Document Server

    Degerlier, M; Gramegna, F; Marchi, T; Palma, M Dalla; Cinausero, M; Maggioni, G; Quaranta, A; Collazuol, G; Bermudez, J

    2013-01-01

    Neutron detectors are extensively used at many nuclear research facilities across Europe. Their application range covers many topics in basic and applied nuclear research: in nuclear structure and reaction dynamics (reaction reconstruction and decay studies); in nuclear astrophysics (neutron emission probabilities); in nuclear technology (nuclear data measurements and in-core/off-core monitors); in nuclear medicine (radiation monitors, dosimeters); in materials science (neutron imaging techniques); in homeland security applications (fissile materials investigation and cargo inspection). Liquid scintillators, widely used at present, have however some drawbacks given by toxicity, flammability, volatility and sensitivity to oxygen that limit their duration and quality. Even plastic scintillators are not satisfactory because they have low radiation hardness and low thermal stability. Moreover organic solvents may affect their optical properties due to crazing. In order to overcome these problems, phenyl-polysilox...

  8. Heat Transfer in Glass, Aluminum, and Plastic Beverage Bottles

    Science.gov (United States)

    Clark, William M.; Shevlin, Ryan C.; Soffen, Tanya S.

    2010-01-01

    This paper addresses a controversy regarding the effect of bottle material on the thermal performance of beverage bottles. Experiments and calculations that verify or refute advertising claims and represent an interesting way to teach heat transfer fundamentals are described. Heat transfer coefficients and the resistance to heat transfer offered…

  9. Heat Transfer in Glass, Aluminum, and Plastic Beverage Bottles

    Science.gov (United States)

    Clark, William M.; Shevlin, Ryan C.; Soffen, Tanya S.

    2010-01-01

    This paper addresses a controversy regarding the effect of bottle material on the thermal performance of beverage bottles. Experiments and calculations that verify or refute advertising claims and represent an interesting way to teach heat transfer fundamentals are described. Heat transfer coefficients and the resistance to heat transfer offered…

  10. Transfer Readiness Pilot Study.

    Science.gov (United States)

    Scott-Skillman, Thelma; And Others

    The California Community Colleges (CCC) has implemented a prototype model for determining student transfer readiness as a primary means of assessing community college transfer effectiveness. This report provides definitions of transfer readiness and guidelines for colleges participating in the CCC transfer readiness study. First, a memorandum from…

  11. Making benefit transfers work

    DEFF Research Database (Denmark)

    Bateman, I.J.; Brouwer, R.; Ferrini, S.

    We develop and test guidance principles for benefits transfers. These argue that when transferring across relatively similar sites, simple mean value transfers are to be preferred but that when sites are relatively dissimilar then value function transfers will yield lower errors. The paper also...

  12. Lunar Materials Handling System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of lunar soil into and out of process equipment in support of in situ resource utilization...

  13. Cryogenic heat transfer

    CERN Document Server

    Barron, Randall F

    2016-01-01

    Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

  14. Iron(II) tetrakis(diaquaplatinum)octacarboxyphthalocyanine supported on multi-walled carbon nanotube platform: an efficient functional material for enhancing electron transfer kinetics and electrocatalytic oxidation of formic acid

    CSIR Research Space (South Africa)

    Mamuru, SA

    2010-10-01

    Full Text Available electrochemical response in terms of (i) electron transfer towards outer-sphere redox probe, (ii) catalytic rate constant, and (iii) tolerance towards CO poisoning during formic acid oxidation. The results clearly suggest that the MWCNT–PtFeOCPc is a promising...

  15. Ballistic Thermal Transfer in Nanosystems

    Directory of Open Access Journals (Sweden)

    A. A. Barinov

    2016-01-01

    Full Text Available This work is concerned with analysis of cross-plane thermal transfer in nanofilms.The paper presents a developed general model of phonon radiation transfer (EPRT based on the Boltzmann transport equation. The EPRT model assumes that the thermal transfer inside a dielectric or metal medium between two metal walls is maintained at different temperatures. These walls are like heat reservoirs; their surfaces are blackbodies. The paper first presents a model of the phonon radiation transfer of the absolute blackbodies in a wide range of temperatures where a model of the ballistic thermal transfer is applicable. It conducts a comparative analysis between phonon radiation transfer and electromagnetic radiation.The basic equation is a formula to calculate a phonon radiation intensity of the absolute blackbody depending on the temperature. Therefore, the formula for the total intensity of phonons is similar to the Stefan-Boltzmann law. The main difference of phonon radiation transfer is that a value of the phonon Stefan-Boltzmann constant is affected by temperature and properties of materials (average acoustic waves in solid bodies and Debye temperature. This can be seen from the curves for Si, Ge, and Diamond.The paper presents a received analytical equation for effective thermal conductivity using a heat flux in a cross-plane direction. The results obtained show the size and temperature dependences of the effective thermal conductivity of silicon, germanium and diamond nanofilms for the ballistic transport in the cross-plane direction. Finally, the paper compares the calculated results with those of available models of different foreign authors, which are in good compliance.

  16. Transplacental transfer of environmental genotoxins

    DEFF Research Database (Denmark)

    Autrup, Herman; Vestergaard, Astrid Beck; Okkels, Henrik

    1995-01-01

    Transplacental transfer of genotoxic material has been determined by measuring the polycyclic aromatic hydrocarbon-albumin adduct level in serum isolated from the mother and the umbilical cord using a competitive ELISA assay and the antibody (8E11) against benzo[a]pyrene (B[a]P) tetrols. Smoking ...... that local production of incomplete combustion products, like vehicle exhaust or heat generation, is the major contributing factor to genotoxic compounds in the general environment....

  17. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  18. Scanning of Vehicles for Nuclear Materials

    CERN Document Server

    Katz, J I

    2014-01-01

    Might a nuclear-armed terrorist group or state use ordinary commerce to deliver a nuclear weapon by smuggling it in a cargo container or vehicle? This delivery method would be the only one available to a sub-state actor, and it might enable a state to make an unattributed attack. Detection of a weapon or fissile material smuggled in this manner is difficult because of the large volume and mass available for shielding. Here I review methods for screening cargo containers to detect the possible presence of nuclear threats. Because of the large volume of innocent international commerce, and the cost and disruption of secondary screening by opening and inspection, it is essential that the method be rapid and have a low false-positive rate. Shielding can prevent the detection of neutrons emitted spontaneously or by induced fission. The two promising methods are muon tomography and high energy X-radiography. If they do not detect a shielded threat object they can detect the shield itself.

  19. Effectof Material Ratio on Phase Transfer Rate of Calcium Ions During Reaction between Calcium Sulfate Dihydrate and Ammonium Carbonate%二水硫酸钙与碳酸铵反应过程中物料比对钙离子相转移速率的影响

    Institute of Scientific and Technical Information of China (English)

    陈昌国; 周加贝; 夏素兰; 王子宁; 宫源; 刘仕忠

    2015-01-01

    选择二水硫酸钙晶须为研究对象,在温度、搅拌速度、料浆浓度不变的条件下,探究了二水硫酸钙与碳酸铵反应过程中物料比 n(NH 4)2 CO 3:nCaSO 4∙2 H 2 O 对钙离子相转移速率的影响。结果表明,物料比在1.05∶1~1.4∶1之间时,生成的碳酸钙沉淀于溶液中,钙离子相转移是溶解-结晶过程,二水硫酸钙转化率和碳酸钙颗粒粒径均随物料比增大而增大,即相转移速率与物料比成正比。%Calcium sulfate dihydrate whiskers were applied under constant temperature,stirring speed and slurry concentration.The material ratio of n(NH 4 )2 CO 3 ∶nCaSO 4 ∙2 H 2 O was changed to study its effect on phase transfer of calcium ions during the reaction between calcium sulfate dihydrate and ammonium car-bonate.The result showed that calcium carbonate crystals were precipitate in solution as the material ratio between 1.05∶1 and 1.4∶1,so corresponding mechanism of calcium ions phase transfer was dissolution-precipitation.It could found that both the conversion rate of calcium sulfate dihydrate and the calcium car-bonate particles size were increased with the increasing value of materials ratio.It indicated that the phase transfer rate of calcium ions was proportional to the material ratio.

  20. Standard test method for non-destructive assay of nuclear material in waste by passive and active neutron counting using a differential Die-away system

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method covers a system that performs nondestructive assay (NDA) of uranium or plutonium, or both, using the active, differential die-away technique (DDT), and passive neutron coincidence counting. Results from the active and passive measurements are combined to determine the total amount of fissile and spontaneously-fissioning material in drums of scrap or waste. Corrections are made to the measurements for the effects of neutron moderation and absorption, assuming that the effects are averaged over the volume of the drum and that no significant lumps of nuclear material are present. These systems are most widely used to assay low-level and transuranic waste, but may also be used for the measurement of scrap materials. The examples given within this test method are specific to the second-generation Los Alamos National Laboratory (LANL) passive-active neutron assay system. 1.1.1 In the active mode, the system measures fissile isotopes such as 235U and 239Pu. The neutrons from a pulsed, 14-MeV ne...

  1. Characterization of the ORNL MVST Waste Tanks After Transfer of Sludge from BVEST, GAAT, and OHF Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.M.

    2001-03-23

    Over the last several years most of the sludge and liquid from the Liquid Low-Level Waste (LLLW) tanks at ORNL has been transferred and consolidated in the Melton Valley Storage Tanks (MVST). The contents of the MVST tanks at the time the sludge samples were collected for this report included the original inventory in the MVSTs along with the sludge and liquid from the Bethel Valley Evaporator Service Tanks (BVEST), Old Hydrofracture (OHF) tanks, and most of the Gunite and Associated Tanks (GAAT). During the spring and summer of 2000 the MVST composite sludge was sampled and characterized to validate the radiochemical content and to ensure regulatory compliance. This report only discusses the analytical characterization of the sludge from the MVST waste tanks (except for W-29 and W-30). The isotopic data presented in this report supports the position that fissile isotopes of uranium ({sup 233}U and {sup 235}U) and plutonium ({sup 239}Pu and {sup 241}Pu) were ''denatured'' as required by the administrative controls stated in the ORNL LLLW waste acceptance criteria (WAC). In general, the MVST sludge was found to be hazardous by RCRA characteristics based on total analysis of chromium, mercury, and lead. Also, the alpha activity due to transuranic isotopes was well above the 100 nCi/g limit for TRU waste. The characteristics of the MVST sludge relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat, were estimated from the data in this report and found to be far below the upper boundary for any of the remote-handled transuranic waste (RH-TRU) requirements for disposal of the waste in WIPP.

  2. 基于离散单元法的丝状颗粒传热数学模型%Model of heat transfer in filamentous granular materials based on discrete element method

    Institute of Scientific and Technical Information of China (English)

    朱立平; 袁竹林; 闫亚明; 罗登山; 王宏生; 李斌

    2012-01-01

    丝状颗粒作为一类长径比较大的非球形颗粒,其传热特性及相关技术广泛应用于工农业生产的诸多领域.但目前颗粒在运动过程中传热问题的研究还很不充分,特别是对于丝状颗粒,更是缺乏有效的数学模型进行描述.从颗粒传热机理出发,提出了一种基于离散单元法的丝状颗粒传热模型,模型中综合考虑了颗粒碰撞(接触)传热、颗粒的内部导热以及颗粒与气体间的对流换热.利用该模型,对固定床中堆积丝状颗粒的热量迁移过程进行了数值模拟,着重比较了各种传热方式对传热过程的影响.研究表明,对流换热对整体传热量的贡献较大.此外,还获得了不同工况下颗粒温度随时间的变化规律.%Filamentous particle is a kind of non-spherical particles with large aspect ratio. It has been widely applied in industrial and agricultural processes. However, the heat transfer phenomenon about particles is not well understood, especially the filamentous particle. In this study, in order to describe the heat transfer process of filamentous particle, a new mathematical model based on the discrete element method was proposed through the analysis of heat transfer mechanisms. The impact heat transfer between particles, the internal heat conduction and the convection heat exchange between gas and particles were considered in this model, and then it was used to numerically study the heat transfer process of filamentous particles in a fixed bed. Comparing the mechanisms with each other, it showed that the convection heat exchange had greater contribution to the total heat transfer. In addition, the simulation results revealed some internal temperature rules in filamentous particles under different operating conditions.

  3. Heat storage system adapted for incongruently melting heat storage materials and congruently melting heat storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, J.L.

    1980-12-30

    A heat storage article adapted for prevention of stratification of incongruently melting heat storage materials, such as eutectic salts, and adapted for use with congruently melting heat storage materials, such as paraffins. The article is comprised of a concrete stone composition, a certain portion of which is comprised of metallic heat transfer materials in order to increase heat transfer through the concrete structure. The concrete structure has an internal cavity which is filled with either the eutectic salt material or the paraffin material.

  4. Waste Transfer Stations

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    tion and transport is usually the most costly part of any waste management system; and when waste is transported over a considerable distance or for a long time, transferring the waste from the collection vehicles to more efficient transportation may be economically beneficial. This involves...... a transfer station where the transfer takes place. These stations may also be accessible by private people, offering flexibility to the waste system, including facilities for bulky waste, household hazardous waste and recyclables. Waste transfer may also take place on the collection route from small...... describes the main features of waste transfer stations, including some considerations about the economical aspects on when transfer is advisable....

  5. Some stakes in heat transfer; Quelques enjeux en transferts thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Saulnier, J.B. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France). Laboratoire d`Etudes Thermiques (LET)

    1998-10-01

    Heat transfer is strongly involved in many scientific and technologic domains and the French heat transfer laboratories and networks cooperating is this field are first located. The analysis of the main industrial activities demanding heat transfer competence helps on first to identify some up-to-date technological challenges. It appears clearly that connections are to be reinforced between disciplines like heat transfer, fluid mechanics, combustion, material science, optics, biology... Scientific objectives are then scanned through, by spitting the research activities between mature topics (radiation, particularly in semi-transparent media; convection and thermo-convective instabilities; heat transfer in porous media...), emerging (heat transfer with change of phase, convective heat transfer enhancement by active control in the boundary layer, inverse techniques...) and incipient ones. Among some promising new topics, let us mention microscale heat transfer, and also bio-heat transfer. (authors)

  6. Special nuclear materials cutoff exercise: Issues and lessons learned. Volume 1: Summary of exercise

    Energy Technology Data Exchange (ETDEWEB)

    Libby, R.A.; Davis, C. [Pacific Northwest Lab., Richland, WA (United States); Segal, J.E.; Stanbro, W.D. [Los Alamos National Lab., NM (United States)

    1995-08-01

    In a September 1993 address to the United Nations General Assembly, President Clinton announced a new nonproliferation and export control policy that established a framework for US efforts to prevent the proliferation of weapons of mass destruction. The new policy proposed that the US undertake a comprehensive approach to the growing accumulation of fissile material. One of the key elements was for the US to support a special nuclear materials (SNM) multilateral convention prohibiting the production of highly enriched uranium (HEU) or plutonium for nuclear explosives purposes or outside of international safeguards. This policy is often referred to as the President`s Cutoff Initiative or the Fissile Material Cutoff Treaty (FMCT). Because both the US Department of Energy (DOE) and foreign reprocessing facilities similar to PUREX will likely to be inspected under a FMCT, the DOE Office of Arms Control and Nonproliferation, Negotiations and Analysis Division (DOE/NN-41) tasked Pacific Northwest Laboratory (PNL) to perform an information gathering exercise, the PUREX Exercise, using the Plutonium-Uranium Extraction (PUREX) Plant located on the Hanford Site in Washington State. PUREX is a former production reactor fuel reprocessing plant currently undergoing a transition to a ``decontamination and decommissioning (D&D) ready`` mode. The PUREX Exercise was conducted March 29--30, 1994, to examine aspects of the imposition of several possible cutoff regimes and to study verification of non-production of SNM for nuclear weapons purposes or outside of safeguards. A follow-up activity to further examine various additional verification regimes was held at Los Alamos National Laboratory (LANL) on May 10, 1994.

  7. Hydrogen bonded supramolecular materials

    CERN Document Server

    Li, Zhan-Ting

    2015-01-01

    This book is an up-to-date text covering topics in utilizing hydrogen bonding for constructing functional architectures and supramolecular materials. The first chapter addresses the control of photo-induced electron and energy transfer. The second chapter summarizes the formation of nano-porous materials. The following two chapters introduce self-assembled gels, many of which exhibit unique functions. Other chapters cover the advances in supramolecular liquid crystals and the versatility of hydrogen bonding in tuning/improving the properties and performance of materials. This book is designed

  8. Nanoparticle enhanced ionic liquid heat transfer fluids

    Science.gov (United States)

    Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.

    2014-08-12

    A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.

  9. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  10. Science Transfer to Turkey

    National Research Council Canada - National Science Library

    Gasimov, Zaur

    2016-01-01

    Transfers between Europe's margins Surely one of the most significant contributions of transfer studies has been its challenge to critically re-think the intra-imperial and inter-imperial relations of Eurasian history...

  11. Introduction to heat transfer

    CERN Document Server

    SUNDÉN, B

    2012-01-01

    Presenting the basic mechanisms for transfer of heat, Introduction to Heat Transfer gives a deeper and more comprehensive view than existing titles on the subject. Derivation and presentation of analytical and empirical methods are provided for calculation of heat transfer rates and temperature fields as well as pressure drop. The book covers thermal conduction, forced and natural laminar and turbulent convective heat transfer, thermal radiation including participating media, condensation, evaporation and heat exchangers.

  12. Transfer of gaming

    NARCIS (Netherlands)

    Korteling, J.E.

    2012-01-01

    An overview is provided of the activities and results op GATE WP 4.4 entiteld Transfer of Gaming (ToG). This work package has produced the principles and methodologies concerning optimalization and measurement of transfer of training in serious gaming. In addition, true transfer of job-specific comp

  13. Diazo transfer for azido-functional surfaces

    Directory of Open Access Journals (Sweden)

    Laura Russo

    2011-04-01

    Full Text Available Preparation of azido-functionalized polymers is gaining increasing attention. We wish to report an innovative, novel strategy for azido functionalization of polymeric materials, coupling plasma technology and solution processed diazo transfer reactions. This novel approach allows the azido group to be introduced downstream of the material preparation, thus preserving its physicochemical and mechanical characteristics, which can be tailored a priori according to the desired application. The whole process involves the surface plasma functionalization of a material with primary amino groups, followed by a diazo transfer reaction, which converts the amino functionalities into azido groups that can be exploited for further chemoselective reactions. The diazo transfer reaction is performed in a heterogeneous phase, where the azido group donor is in solution. Chemical reactivity of the azido functionalities was verified by subsequent copper-catalyzed azide-alkyne cycloaddition.

  14. Heat transfer and thermal control

    Science.gov (United States)

    Crosbie, A. L.

    Radiation heat transfer is considered along with conduction heat transfer, heat pipes, and thermal control. Attention is given to the radiative properties of a painted layer containing nonspherical pigment, bidirectional reflectance measurements of specular and diffuse surfaces with a simple spectrometer, the radiative equilibrium in a general plane-parallel environment, and the application of finite-element techniques to the interaction of conduction and radiation in participating medium, a finite-element approach to combined conductive and radiative heat transfer in a planar medium. Heat transfer in irradiated shallow layers of water, an analytical and experimental investigation of temperature distribution in laser heated gases, numerical methods for the analysis of laser annealing of doped semiconductor wafers, and approximate solutions of transient heat conduction in a finite slab are also examined. Consideration is also given to performance testing of a hydrogen heat pipe, heat pipe performance with gravity assist and liquid overfill, vapor chambers for an atmospheric cloud physics laboratory, a prototype heat pipe radiator for the German Direct Broadcasting TV Satellite, free convection in enclosures exposed to compressive heating, and a thermal analysis of a multipurpose furnace for material processing in space.

  15. Energy conservation in refrigerating machines by combining of thermo-static expansion valve and interior heat transfer material; Energieeinsparung in Kaelteanlagen durch Kombination von thermostatischem Expansionsventil und innerem Waermeuebertrager

    Energy Technology Data Exchange (ETDEWEB)

    Tambovtsev, Alexander

    2007-12-15

    The invention of the refrigerating machine enables to generate cold energy in any needed amount and at any desired temperature. However, cold energy generation requires driving energy. The target of this dissertation is to reduce the energy consumption of refrigerating plants considerably by means of an intelligent combination of the thermo-static expansion valve and the interior heat transfer medium. This combination should not deteriorate the reliability nor incur additional costs. Until today the two known components thermo-static expansion valve and interior heat transfer medium are considered as incompatible, because the simple connection of both components leads to an unstable control behaviour. After a detailed analysis of the causes for this instability the hypothesis is made, a stable working area can be found by means of a deliberate ''deterioration'' of the internal heat transfer medium. This ''deterioration'' can be e.g. a bypass of a part of the high-pressure flow or a parallel flow arrangement of the flows in the heat transfer medium. This hypothesis was primarily proved by experiments, but also by simulation calculations. A test stand was set-up for this purpose, which was used to test various configurations and control strategies. A considerable reduction of the energy consumption compared to conventional arrangements was achieved. (orig.) [German] Die Erfindung der Kaeltemaschine macht es moeglich, dass heute zu beliebiger Zeit Kaelte in benoetigter Menge und gewuenschter Temperatur erzeugt werden kann. Aber fuer die Kaelteerzeugung braucht man Antriebsenergie. Das Ziel dieser Doktorarbeit besteht darin, mit einer intelligenten Kombination von thermostatischem Expansionsventil (TEV) und innerem Waermeuebertrager (IWUe) den Energieverbrauch von Kaelteanlagen deutlich zu verringern, ohne dass dies zu einer Verschlechterung der Zuverlaessigkeit oder wesentlichen Mehrkosten fuehrt. Bis heute gelten die beiden

  16. Double-layered cell transfer technology for bone regeneration.

    Science.gov (United States)

    Akazawa, Keiko; Iwasaki, Kengo; Nagata, Mizuki; Yokoyama, Naoki; Ayame, Hirohito; Yamaki, Kazumasa; Tanaka, Yuichi; Honda, Izumi; Morioka, Chikako; Kimura, Tsuyoshi; Komaki, Motohiro; Kishida, Akio; Izumi, Yuichi; Morita, Ikuo

    2016-09-14

    For cell-based medicine, to mimic in vivo cellular localization, various tissue engineering approaches have been studied to obtain a desirable arrangement of cells on scaffold materials. We have developed a novel method of cell manipulation called "cell transfer technology", enabling the transfer of cultured cells onto scaffold materials, and controlling cell topology. Here we show that using this technique, two different cell types can be transferred onto a scaffold surface as stable double layers or in patterned arrangements. Various combinations of adherent cells were transferred to a scaffold, amniotic membrane, in overlapping bilayers (double-layered cell transfer), and transferred cells showed stability upon deformations of the material including folding and trimming. Transplantation of mesenchymal stem cells from periodontal ligaments (PDLSC) and osteoblasts, using double-layered cell transfer significantly enhanced bone formation, when compared to single cell type transplantation. Our findings suggest that this double-layer cell transfer is useful to produce a cell transplantation material that can bear two cell layers. Moreover, the transplantation of an amniotic membrane with PDLSCs/osteoblasts by cell transfer technology has therapeutic potential for bone defects. We conclude that cell transfer technology provides a novel and unique cell transplantation method for bone regeneration.

  17. Armas brasileiras na América Central: um estudo sob a perspectiva da Política Nacional de Exportação de Material de Emprego Militar - PNEMEM (1974-1991 Brazilian arms in Central America: a study in the perspective of the Brazilian's Arms Transfer Policy - PNEMEM (1974-1991

    Directory of Open Access Journals (Sweden)

    Carlos Federico Domínguez Avila

    2009-06-01

    Full Text Available O artigo avalia a Política Nacional de Exportação de Material de Emprego Militar e seu impacto nas relações brasileiro-centro-americanas durante os anos 1970 e 1980. Parte-se do critério que o comércio internacional de armas implica relevantes consequências políticas, econômicas e estratégicas, especialmente quando se trata de transferências para países em conflito interno ou regional. O texto utiliza fontes primárias resgatadas no Arquivo Histórico do Ministério das Relações Exteriores do Brasil (AHMRE.The paper explores the Brazilian's Arms Transfer Policy and its impact in the Brazilian-Central American relations between 1970 and 1990. The text suggests that arms transfer has relevant politics, economics and strategic consequences, particularly in countries with national or regional conflicts. The paper uses some information from the Brazil's Foreign Affairs Archives.

  18. Standards for compatibility of printed circuit and component lead materials

    Science.gov (United States)

    1968-01-01

    Study of packaging of microminiature electronic components reveals methods of improving compatibility of lead materials, joining techniques, transfer molding concepts, printed circuit board materials, and process and material specifications.

  19. Preliminary concepts: materials management in an internationally safeguarded nuclear-waste geologic repository

    Energy Technology Data Exchange (ETDEWEB)

    Ostenak, C.A.; Whitty, W.J.; Dietz, R.J.

    1979-11-01

    Preliminary concepts of materials accountability are presented for an internationally safeguarded nuclear-waste geologic repository. A hypothetical reference repository that receives nuclear waste for emplacement in a geologic medium serves to illustrate specific safeguards concepts. Nuclear wastes received at the reference repository derive from prior fuel-cycle operations. Alternative safeguards techniques ranging from item accounting to nondestructive assay and waste characteristics that affect the necessary level of safeguards are examined. Downgrading of safeguards prior to shipment to the repository is recommended whenever possible. The point in the waste cycle where international safeguards may be terminate depends on the fissile content, feasibility of separation, and practicable recoverability of the waste: termination may not be possible if spent fuels are declared as waste.

  20. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  1. Transfer function combinations

    KAUST Repository

    Zhou, Liang

    2012-10-01

    Direct volume rendering has been an active area of research for over two decades. Transfer function design remains a difficult task since current methods, such as traditional 1D and 2D transfer functions, are not always effective for all data sets. Various 1D or 2D transfer function spaces have been proposed to improve classification exploiting different aspects, such as using the gradient magnitude for boundary location and statistical, occlusion, or size metrics. In this paper, we present a novel transfer function method which can provide more specificity for data classification by combining different transfer function spaces. In this work, a 2D transfer function can be combined with 1D transfer functions which improve the classification. Specifically, we use the traditional 2D scalar/gradient magnitude, 2D statistical, and 2D occlusion spectrum transfer functions and combine these with occlusion and/or size-based transfer functions to provide better specificity. We demonstrate the usefulness of the new method by comparing to the following previous techniques: 2D gradient magnitude, 2D occlusion spectrum, 2D statistical transfer functions and 2D size based transfer functions. © 2012 Elsevier Ltd.

  2. Making benefit transfers work

    DEFF Research Database (Denmark)

    Bateman, I.J.; Brouwer, R.; Ferrini, S.

    We develop and test guidance principles for benefits transfers. These argue that when transferring across relatively similar sites, simple mean value transfers are to be preferred but that when sites are relatively dissimilar then value function transfers will yield lower errors. The paper also...... provides guidance on the appropriate specification of transferable value functions arguing that these should be developed from theoretical rather than ad-hoc statistical principles. These principles are tested via a common format valuation study of water quality improvements across five countries. Results...... support our various hypotheses providing a set of principles for future transfer studies. The application also considers new ways of incorporating distance decay, substitution and framing effects within transfers and presents a novel water quality ladder....

  3. Making benefit transfers work

    DEFF Research Database (Denmark)

    Bateman, I. J.; Brouwer, R.; Ferrini, S.

    2011-01-01

    We develop and test guidance principles for benefits transfers. These argue that when transferring across relatively similar sites, simple mean value transfers are to be preferred but that when sites are relatively dissimilar then value function transfers will yield lower errors. The paper also...... provides guidance on the appropriate specification of transferable value functions arguing that these should be developed from theoretical rather than ad-hoc statistical principles. These principles are tested via a common format valuation study of water quality improvements across five countries. Results...... support our various hypotheses providing a set of principles for future transfer studies. The application also considers new ways of incorporating distance decay, substitution and framing effects within transfers and presents a novel water quality ladder....

  4. DNA deposition through laser induced forward transfer.

    Science.gov (United States)

    Colina, M; Serra, P; Fernández-Pradas, J M; Sevilla, L; Morenza, J L

    2005-02-15

    Laser induced forward transfer (LIFT) is a laser direct write technique that appears to be specially adequate for the production of biosensors, since it permits to deposit patterns of biomolecules with high spatial resolution. In the LIFT technique, a laser pulse is focused on a thin film of the material to be transferred through a transparent support, and under the action of the laser pulse, a small fraction of the film is transferred to a receptor substrate that is placed parallel to the film-support system. In the case of biomolecules transfer, the thin film consists in a liquid solution containing the biomolecules. In this work, microarrays of two different cDNAs have been both spotted by LIFT and pin microspotting onto a poly-L-lysine treated glass slide. Once transferred, all the microarrays have been submitted to hybridization with the complementary strands of the spotted cDNAs, each one tagged with a different fluorochrome. Comparative fluorescence scanner analyses have revealed that the microarrays transferred through LIFT are equivalent to those transferred through pin microspotting in terms of signal intensity and gene discrimination capacity, and that the action of the laser pulse does not result in significant damage of the transferred DNA.

  5. Geothermal Heat Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Basmajian, V.V.

    1986-01-28

    This patent describes a heat transfer apparatus which consists of: heat exchanging means for orientation in the earth below ground substantially vertically, having a hollow conduit of length from top to bottom much greater than the span across the hollow conduit orthogonal to its length with a top, bottom and an intermediate portion contiguous and communicating with the top and bottom portions for allowing thermally conductive fluid to flow freely between the top, intermediate and bottom portions for immersion in thermally conductive fluid in the region around the heat exchanging means for increasing the heat flow between the latter and earth when inserted into a substantially vertical borehole in the earth with the top portion above the bottom portion. The heat exchanger consists of heat exchanging conduit means in the intermediate portion for carrying refrigerant. The heat exchanging conduit consisting of tubes of thermally conductive material for carrying the refrigerant and extending along the length of the hollow conduit for a tube length that is less than the length of the hollow conduit. The hollow conduit is formed with port means between the top and the plurality of tubes for allowing the thermally conductive fluid to pass in a flow path embracing the tubes, the bottom portion, an outer channel around the hollow conduit and the port means.

  6. Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

    NARCIS (Netherlands)

    Taha, T.J.; Thakur, D.B.; van der Meer, Theodorus H.

    2012-01-01

    In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon nan

  7. Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

    NARCIS (Netherlands)

    Taha, T.J.; Thakur, D.B.; Meer, van der T.H.

    2012-01-01

    In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon nan

  8. Studying on the Heat Transfer Performance of New Wall Materials in Hot Summer and Cold Winter Zone%夏热冬冷地区新型墙体材料传热性能研究

    Institute of Scientific and Technical Information of China (English)

    李尚梅; 傅俊萍; 杨伟军; 谢武刚

    2011-01-01

    In this paper, a theoretical analysis is carried out on the thermal insulation of wall material, according to a rule in design standard for energy efficiency in hot summer and cold winter zone, conducting a thermal insulation property checking calculation for four kinds of wall materials: new wall materials of autoclaved aerated concrete block and normal concrete small-sized hollow block, traditional wall materials of common clay brick and experimental wall material of hollow plaster slab. Also through testing on insulation on single hollow plaster slab in cold winter, a conclusion has been drawn that thermal performance of building envelope is related to the difference of indoor and outdoor relative humidity in hot summer and cold winter zone.%根据夏热冬冷地区国家节能标准规范验算了新型墙体材料蒸压加气混凝土砌块及普通混凝土小型空心砌块墙体、传统的红色粘土砖墙体以及实验所用的石膏空心砌块墙体的保温隔热性能。并通过对石膏空心砌块墙体材料进行冬季保温测试,得出夏热冬冷地区围护结构热工性能与室内外相对湿度差值有关。

  9. 76 FR 44761 - Remittance Transfers

    Science.gov (United States)

    2011-07-27

    ... Electronic Fund Transfer Act (EFTA), as an example of money transfer instruments Federal credit unions (FCUs... receiving international and domestic electronic fund transfers'' after the words ``money orders'' from... checks, money orders, and other similar transfer instruments, including international and...

  10. Probability of Detection Demonstration Transferability

    Science.gov (United States)

    Parker, Bradford H.

    2008-01-01

    The ongoing Mars Science Laboratory (MSL) Propellant Tank Penetrant Nondestructive Evaluation (NDE) Probability of Detection (POD) Assessment (NESC activity) has surfaced several issues associated with liquid penetrant POD demonstration testing. This presentation lists factors that may influence the transferability of POD demonstration tests. Initial testing will address the liquid penetrant inspection technique. Some of the factors to be considered in this task are crack aspect ratio, the extent of the crack opening, the material and the distance between the inspection surface and the inspector's eye.

  11. Utrecht Radiative Transfer Courses

    Science.gov (United States)

    Rutten, R. J.

    2003-01-01

    The Utrecht course ``The Generation and Transport of Radiation'' teaches basic radiative transfer to second-year students. It is a much-expanded version of the first chapter of Rybicki & Lightman's ``Radiative Processes in Astrophysics''. After this course, students understand why intensity is measured per steradian, have an Eddington-Barbier feel for optically thick line formation, and know that scattering upsets LTE. The text is a computer-aided translation by Ruth Peterson of my 1992 Dutch-language course. My aim is to rewrite this course in non-computer English and make it web-available at some time. In the meantime, copies of the Peterson translation are made yearly at Uppsala -- ask them, not me. Eventually it should become a textbook. The Utrecht course ``Radiative Transfer in Stellar Atmospheres'' is a 30-hour course for third-year students. It treats NLTE line formation in plane-parallel stellar atmospheres at a level intermediate between the books by Novotny and Boehm-Vitense, and Mihalas' ``Stellar Atmospheres''. After this course, students appreciate that epsilon is small, that radiation can heat or cool, and that computers have changed the field. This course is web-available since 1995 and is regularly improved -- but remains incomplete. Eventually it should become a textbook. The three Utrecht exercise sets ``Stellar Spectra A: Basic Line Formation'', ``Stellar Spectra B: LTE Line Formation'', and ``Stellar Spectra C: NLTE Line Formation'' are IDL-based computer exercises for first-year, second-year, and third-year students, respectively. They treat spectral classification, Saha-Boltzmann population statistics, the curve of growth, the FAL-C solar atmosphere model, the role of H-minus in the solar continuum, LTE formation of Fraunhofer lines, inversion tactics, the Feautrier method, classical lambda iteration, and ALI computation. The first two sets are web-available since 1998; the third will follow. Acknowledgement. Both courses owe much to previous

  12. Electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Abouimrane, Ali; Belharouak, Ilias

    2017-01-31

    A process for forming a surface-treatment layer on an electroactive material includes heating the electroactive material and exposing the electroactive material to a reducing gas to form a surface-treatment layer on the electroactive material, where the surface-treatment layer is a layer of partial reduction of the electroactive material.

  13. An adaptive simulation model for analysis of nuclear material shipping operations

    Energy Technology Data Exchange (ETDEWEB)

    Boerigter, S.T.; Sena, D.J.; Fasel, J.H.

    1998-12-31

    Los Alamos has developed an advanced simulation environment designed specifically for nuclear materials operations. This process-level simulation package, the Process Modeling System (ProMoS), is based on high-fidelity material balance criteria and contains intrinsic mechanisms for waste and recycle flows, contaminant estimation and tracking, and material-constrained operations. Recent development efforts have focused on coupling complex personnel interactions, personnel exposure calculations, and stochastic process-personnel performance criteria to the material-balance simulation. This combination of capabilities allows for more realistic simulation of nuclear material handling operations where complex personnel interactions are required. They have used ProMoS to assess fissile material shipping performance characteristics at the Los Alamos National Laboratory plutonium facility (TA-55). Nuclear material shipping operations are ubiquitous in the DOE complex and require the largest suite of varied personnel interacting in a well-timed manner to accomplish the task. They have developed a baseline simulation of the present operations and have estimated the operational impacts and requirement of the pit production mission at TA-55 as a result of the SSM-PEIS. Potential bottlenecks have been explored and mechanisms for increasing operational efficiency are identified.

  14. Calculating proper transfer prices

    Energy Technology Data Exchange (ETDEWEB)

    Dorkey, F.C. (Meliora Research Associates, Rochester, NY (United States)); Jarrell, G.A. (Univ. of Rochester, NY (United States))

    1991-01-01

    This article deals with developing a proper transfer pricing method. Decentralization is as American as baseball. While managers laud the widespread benefits of both decentralization and baseball, they often greet the term transfer price policy with a yawn. Since transfer prices are as critical to the success of decentralized firms as good pitchers are to baseball teams, this is quite a mistake on the part of our managers. A transfer price is the price charged to one division for a product or service that another division produced or provided. In many, perhaps most, decentralized organizations, the transfer pricing policies actually used are grossly inefficient and sacrifice the potential advantages of decentralization. Experience shows that far too many companies have transfer pricing policies that cost them significantly in foregone growth and profits.

  15. Waste Transfer Stations

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    tion and transport is usually the most costly part of any waste management system; and when waste is transported over a considerable distance or for a long time, transferring the waste from the collection vehicles to more efficient transportation may be economically beneficial. This involves...... a transfer station where the transfer takes place. These stations may also be accessible by private people, offering flexibility to the waste system, including facilities for bulky waste, household hazardous waste and recyclables. Waste transfer may also take place on the collection route from small...... satellite collection vehicles to large compacting vehicles that cannot effectively travel small streets and alleys within the inner city or in residential communities with narrow roads. However, mobile transfer is not dealt with in this chapter, which focuses on stationary transfer stations. This chapter...

  16. Strategic Transfer Pricing

    OpenAIRE

    Michael Alles; Srikant Datar

    1998-01-01

    Most research into cost systems has focused on their motivational implications. This paper takes a different approach, by developing a model where two oligopolistic firms strategically select their cost-based transfer prices. Duopoly models frequently assume that firms game on their choice of prices. Product prices, however, are ultimately based on the firms' transfer prices that communicate manufacturing costs to marketing departments. It is for this reason that transfer prices will have a s...

  17. Effective Bayesian Transfer Learning

    Science.gov (United States)

    2010-03-01

    insufficient (most models) and models where clusters containing more than a few variables are too costly (e.g., stereopsis ). 10 Models where...detections 2D hypoth 3D hypoth 32 Stanford Traffic Vision: Year 1 Summary PI: Thrun •! Developed transfer machine learning technique. •! Transfer at...Detection, classification, and prediction of vehicular traffic . •! Is an application of Transfer Learning to the Visual Domain •! Impact: May make

  18. Wireless power transfer system

    OpenAIRE

    Arai, Hiroyuki

    2012-01-01

    This paper presents a survey of recent wireless power transfer systems. The issue of wireless power transfer is to achieve a highly efficient system with small positioning errors of the facilities setting. Several theories have been presented to obtain precise system design. This paper presents a summary of design theory for short range power transfer systems and detailed formulations based on a circuit model and an array of infinitesimal dipoles. In addition to these theories, this paper in...

  19. Keypoint Transfer Segmentation

    OpenAIRE

    Wachinger, C.; Toews, M.; Langs, G.; Wells, W.; Golland, P.

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for th...

  20. PLUGGING AND UNPLUGGING OF WASTE TRANSFER PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    This project, which began in FY97, involves both the flow loop research on plugging and unplugging of waste transfer pipelines, and the large-scale industrial equipment test of plugging locating and unplugging technologies. In FY98, the related work was performed under the project name ''Mixing, Settling, and Pipe Unplugging of Waste Transfer Lines.'' The mixing, settling, and pipeline plugging and unplugging are critical to the design and maintenance of a waste transfer pipeline system, especially for the High-Level Waste (HLW) pipeline transfer. The major objective of this work is to recreate pipeline plugging conditions for equipment testing of plug locating and removal and to provide systematic operating data for modification of equipment design and enhancement of performance of waste transfer lines used at DOE sites. As the waste tank clean-out and decommissioning program becomes active at the DOE sites, there is an increasing potential that the waste slurry transfer lines will become plugged and unable to transport waste slurry from one tank to another or from the mixing tank to processing facilities. Transfer systems may potentially become plugged if the solids concentration of the material being transferred increases beyond the capability of the prime mover or if upstream mixing is inadequately performed. Plugging can occur due to the solids' settling in either the mixing tank, the pumping system, or the transfer lines. In order to enhance and optimize the slurry's removal and transfer, refined and reliable data on the mixing, sampling, and pipe unplugging systems must be obtained based on both laboratory-scale and simulated in-situ operating conditions.