WorldWideScience

Sample records for transport header temperature

  1. Header integrity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rotvel, F. [ELSAMPROJEKT, Fredericia (Denmark); Sampietri, C. [ENEL, Milano (Italy); Verelst, L. [LABORELEC, Linkebeek (Belgium); Wortel, H. van [TNO, Apeldoorn (Netherlands); Li Ying Zhi [KEMA, Arnhem (Netherlands)

    1998-12-31

    In the late eighties creep cracks in the nozzle-to-header welds of high temperature headers became internationally recognized as a problem in older steam power plants. To study the problem a 2 1/4Cr1Mo service-exposed header, which was scrapped due to creep damage, was made available for testing. A full-scale model was fabricated with partly repaired nozzle to header welds and then tested at increased temperature. Loads included internal pressure and system loads. Damage accumulation and creep crack initiation and growth were predicted and experimentally verified. Conclusions and the practical implications for power plant operation are described. (orig.) 7 refs.

  2. Power raise through improved reactor inlet header temperature measurement at Bruce A Nuclear Generation Station

    International Nuclear Information System (INIS)

    Basu, S.; Bruggemn, D.

    1997-01-01

    Reactor Inlet Header (RIH) temperature has become a factor limiting the performance of the Ontario Hydro Bruce A units. Specifically, the RIH temperature is one of several parameters that is preventing the Bruce A units from returning to 94% power operation. RIH temperature is one of several parameters which affect the critical heat flux in the reactor channel, and hence the integrity of the fuel. Ideally, RIH temperature should be lowered, but this cannot be done without improving the heat transfer performance of the boilers and feedwater pre-heaters. Unfortunately, the physical performance of the boilers and pre-heaters has decayed and continues to decay over time and as a result the RIH temperature has been rising and approaching its defined limit. With an understanding of the current RIH temperature measurement loop and methods available to improve it, a solution to reduce the measurement uncertainty is presented

  3. Remaining life assessment of carbon steel boiler headers by repeated creep testing

    Energy Technology Data Exchange (ETDEWEB)

    Drew, M. [ANSTO, Materials and Engineering Science, New Illawarra Road, Lucas Heights, PMB 1 Menai, NSW 2234 (Australia)]. E-mail: michael.drew@ansto.gov.au; Humphries, S. [ANSTO, Materials and Engineering Science, New Illawarra Road, Lucas Heights, PMB 1 Menai, NSW 2234 (Australia); Thorogood, K. [ANSTO, Materials and Engineering Science, New Illawarra Road, Lucas Heights, PMB 1 Menai, NSW 2234 (Australia); Barnett, N. [BlueScope Steel, P.O. Box 1854, Wollongong, NSW (Australia)

    2006-05-15

    The condition of carbon steel boiler headers that have been in service for over 25 years has been assessed periodically by NDT, dimensional measurements, replication and accelerated creep testing. Historical temperature records were limited, so estimates of effective header temperatures were made from replicas. These estimates were compared with header stub thermocouple readings. At about 280,000 service hours, samples were chain-drilled from the headers for accelerated creep testing. These test results indicated that the headers had satisfactory remaining life. Nine years after the original samples were taken, additional samples were removed from one header at 337,000 service hours. The creep rupture properties measured from the repeated tests were almost identical to the initial results. A mild degree of random, nodular graphite was found in the samples and its effect on creep properties is discussed.

  4. Conceptual design of a chickpea harvesting header

    Directory of Open Access Journals (Sweden)

    H. Golpira

    2013-07-01

    Full Text Available Interest in the development of stripper headers is growing owing to the excessive losses of combine harvesters and costs of manually harvesting for chickpeas. The design of a new concept can enhance the mechanized process for chickpea harvesting. A modified stripper platform was designed, in which passive fingers with V-shape slots removes the pods from the anchored plant. The floating platform was accompanied by a reel to complete the harvesting header. Black-box modeling was used to redesign the functional operators of the header followed by an investigation of the system behavior. Physical models of the platform and reel were modified to determine the crucial variables of the header arrangement during field trials. The slot width was fixed at 40 mm, finger length at 40 mm, keyhole diameter at 10 mm and entrance width at 6 mm; the batted reel at peripheral diameter of 700 mm and speed at 50 rpm. A tractor-mounted experimental harvester was built to evaluate the work quality of the stripper header. The performance of the prototype was tested with respect to losses and results confirmed the efficiency of the modified stripper header for chickpea harvesting. Furthermore, the header with a 1.4 m working width produced the spot work rates of 0.42 ha h-1.

  5. Multi-protocol header generation system

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, David A.; Ignatowski, Michael; Jayasena, Nuwan; Loh, Gabriel

    2017-09-05

    A communication device includes a data source that generates data for transmission over a bus, and a data encoder that receives and encodes outgoing data. An encoder system receives outgoing data from a data source and stores the outgoing data in a first queue. An encoder encodes outgoing data with a header type that is based upon a header type indication from a controller and stores the encoded data that may be a packet or a data word with at least one layered header in a second queue for transmission. The device is configured to receive at a payload extractor, a packet protocol change command from the controller and to remove the encoded data and to re-encode the data to create a re-encoded data packet and placing the re-encoded data packet in the second queue for transmission.

  6. Determination of temperature measurements uncertainties of the heat transport primary system of Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Pomerantz, Marcelo E.; Coutsiers, Eduardo E.; Moreno, Carlos A.

    1999-01-01

    In this work, the systematic errors in temperature measurements in inlet and outlet headers of HTPS coolant channels of Embalse nuclear power plant are evaluated. These uncertainties are necessary for a later evaluation of the channel power maps transferred to the coolant. The power maps calculated in this way are used to compare power distributions using neutronic codes. Therefore, a methodology to correct systematic errors of temperature in outlet feeders and inlet headers is developed in this work. (author)

  7. Enabling IP Header Compression in COTS Routers via Frame Relay on a Simplex Link

    Science.gov (United States)

    Nguyen, Sam P.; Pang, Jackson; Clare, Loren P.; Cheng, Michael K.

    2010-01-01

    NASA is moving toward a networkcentric communications architecture and, in particular, is building toward use of Internet Protocol (IP) in space. The use of IP is motivated by its ubiquitous application in many communications networks and in available commercial off-the-shelf (COTS) technology. The Constellation Program intends to fit two or more voice (over IP) channels on both the forward link to, and the return link from, the Orion Crew Exploration Vehicle (CEV) during all mission phases. Efficient bandwidth utilization of the links is key for voice applications. In Voice over IP (VoIP), the IP packets are limited to small sizes to keep voice latency at a minimum. The common voice codec used in VoIP is G.729. This new algorithm produces voice audio at 8 kbps and in packets of 10-milliseconds duration. Constellation has designed the VoIP communications stack to use the combination of IP/UDP/RTP protocols where IP carries a 20-byte header, UDP (User Datagram Protocol) carries an 8-byte header, and RTP (Real Time Transport Protocol) carries a 12-byte header. The protocol headers total 40 bytes and are equal in length to a 40-byte G.729 payload, doubling the VoIP latency. Since much of the IP/UDP/RTP header information does not change from IP packet to IP packet, IP/UDP/RTP header compression can avoid transmission of much redundant data as well as reduce VoIP latency. The benefits of IP header compression are more pronounced at low data rate links such as the forward and return links during CEV launch. IP/UDP/RTP header compression codecs are well supported by many COTS routers. A common interface to the COTS routers is through frame relay. However, enabling IP header compression over frame relay, according to industry standard (Frame Relay IP Header Compression Agreement FRF.20), requires a duplex link and negotiations between the compressor router and the decompressor router. In Constellation, each forward to and return link from the CEV in space is treated

  8. Page header image | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Page header image. Chestnut farm worker carries basket of harvest chestnuts on shoulders in China. What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map · Copyright · Open access policy · Privacy policy · Research ethics · Transparency · Website usage.

  9. Page header image | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Page header image. What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map · Copyright · Open access policy · Privacy policy · Research ethics · Transparency · Website usage. Follow us; Facebook · Twitter · Youtube · Linked In · RSS Feed. © 2016 IDRC. All rights ...

  10. Testing Header Component of Electricity Power Industry Boiler

    International Nuclear Information System (INIS)

    Soedardjo, S.A; Andryansyah, B; Artahari, Dewi; Natsir, Muhammad; Triyadi, Ari; Farokhi

    2000-01-01

    Testing of header component of Suralaya Unit II electricity power by replication method has been carried out. That header component is cross over pipe which interconnection between Primary and Superheater Outlet Header Secondary Superheater Outlet Header with the operation time over 14 years. The main composition of cross over pipe is 2 1/4 Cr 1 Mo or frequently specified as ferritique steel. The replication testing shown that the damage classification on those cross over pipe in A class based on failure classification from Neubauer and Wedel. Simple calculation in favor of cross over pipe remaining lifetime is about 16.5 years moreover

  11. Threats and surprises behind IPv6 extension headers

    NARCIS (Netherlands)

    Hendriks, Luuk; Velan, Petr; de Oliveira Schmidt, Ricardo; De Boer, Pieter Tjerk; Pras, Aiko

    2017-01-01

    The concept of Extension Headers, newly introduced with IPv6, is elusive and enables new types of threats in the Internet. Simply dropping all traffic containing any Extension Header - a current practice by operators-seemingly is an effective solution, but at the cost of possibly dropping legitimate

  12. Mechanical design of the hot steam headers of the THTR-300 steam generators

    International Nuclear Information System (INIS)

    Blumer, U.; Stumpf, M.

    1988-01-01

    The high pressure steam headers of the THTR steam generators have been subject to special attention during the design phase due to the following reasons: these components are the pressure retaining parts with the heaviest wall thickness in the region of the steam generators; they therefore are sensitive to thermal transient conditions; they are operated in the elevated temperature regime, where creep effects cannot be neglected; there is almost no service experience from fossil steam generators with this type of material (Alloy 800). Safety consideration therefore have been rather extensive and have focussed on two main areas which will be treated in this paper: 1. Analytical investigations on the cyclic material behaviour under all specified operating conditions, taking into account the non-elastic response of the material. 2. Limitation of the consequences of a header rupture by installation of heavy whip restraints. Elastic-plastic-creep analyses: The analyses were performed in different stages and are explained in the corresponding order: Evaluation of the critical location on the header and establishment of a simplified model of a nozzle region for further analysis. Preliminary thermal analyses of all specified transient conditions on simplified procedures, in order to establish a severity ranking of the conditions. Establishment of representative loading blocks. Evaluation of the material properties for thermal and structural, especially non-elastic behaviour. Detailed thermal analyses. Detailed structural analyses of the non-elastic cyclic response. Extrapolation for all cycles and assessment of the results by design codes. Discussion of the results. Header whip restraint design: In addition to the above analysis efforts, heavy whip restraints were provided to assure limitation of the effects of a header failure. This pager shows the measures that were taken to restrain the movement in case of longitudinal and transverse breaks: The anti-whip designs are

  13. Summary report on underground road header environmental control.

    CSIR Research Space (South Africa)

    Belle, BK

    2002-01-01

    Full Text Available The primary objective of the Road Header (RH) environmental control project is to minimise the dust exposure of workers while maintaining adequate ventilation conditions in RH headings in order to optimise the working environment of mine workers...

  14. Transport temperatures observed during the commercial transportation of animals

    Directory of Open Access Journals (Sweden)

    Gianluca Fiore

    2012-03-01

    Full Text Available Current temperature standards and those proposed by the European Food Safety Authority (EFSA were compared with the actual practices of commercial transport in the European Union. Temperature and humidity records recorded for a year on 21 vehicles over 905 journeys were analysed. Differences in temperature and humidity recorded by sensors at four different positions in the vehicles exceeded 10°C between the highest and lowest temperatures in nearly 7% of cases. The number and position of temperature sensors are important to ensure the correct representation of temperature conditions in the different parts of a vehicle. For all journeys and all animal categories, a relatively high percentage of beyond threshold temperatures can be observed in relation to the temperature limits of 30°C and 5°C. Most recorded temperature values lie within the accepted tolerance of ±5°C stipulated in European Community Regulation (EC 1/2005. The temperature thresholds proposed by EFSA would result in a higher percentage of non-compliant conditions which are more pronounced at the lower threshold, compared to the thresholds laid down in Regulation (EC 1/2005. With respect to the different animal categories, the non-compliant temperature occurrences were more frequent in pigs and sheep, in particular with regard to the thresholds proposed by EFSA.

  15. Temperature-dependent Transport Properties of Graphene

    Science.gov (United States)

    Zhong, Bochen; Singh, Amol; Uddin, Ahsan; Koley, Goutam; Webb, Richard

    2014-03-01

    Temperature-dependent transport properties of graphene synthesized by chemical vapor deposition (CVD) on a Cu thin sheet have been investigated. Raman spectra of our samples show good quality of the CVD graphene. We have measured the temperature dependence of conductivity, charge-carrier density and Hall mobility of graphene by patterning them into micrometer-sized Hall bars. Quantum Hall effect has been observed when the temperature is about 60 Kelvin, which is the evidence for single-layer graphene. Furthermore, the results of temperature dependence of Hall mobility indicate that impurity and defect scattering is the primary scattering mechanism at low temperature, while substrate surface polar phonon scattering is dominant at high temperature.

  16. Packet Header Compression for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Pekka KOSKELA

    2016-01-01

    Full Text Available Due to the extensive growth of Internet of Things (IoT, the number of wireless devices connected to the Internet is forecasted to grow to 26 billion units installed in 2020. This will challenge both the energy efficiency of wireless battery powered devices and the bandwidth of wireless networks. One solution for both challenges could be to utilize packet header compression. This paper reviews different packet compression, and especially packet header compression, methods and studies the performance of Robust Header Compression (ROHC in low speed radio networks such as XBEE, and in high speed radio networks such as LTE and WLAN. In all networks, the compressing and decompressing processing causes extra delay and power consumption, but in low speed networks, energy can still be saved due to the shorter transmission time.

  17. TCP with header checksum option for wireless links: An analytical ...

    Indian Academy of Sciences (India)

    In earlier work, it has been shown that adding a TCP header checksum is very useful in differentiating between congestion loss and corruption loss. With the modified TCP, receivers can explicitly indicate corruption of received packets by generating “Explicit Loss Notifications (ELNs).” This paper focuses on an analytical ...

  18. Technology Corner: Analysing E-mail Headers For Forensic Investigation

    Directory of Open Access Journals (Sweden)

    M. Tariq Banday

    2011-06-01

    Full Text Available Electronic Mail (E-Mail, which is one of the most widely used applications of Internet, has become a global communication infrastructure service.  However, security loopholes in it enable cybercriminals to misuse it by forging its headers or by sending it anonymously for illegitimate purposes, leading to e-mail forgeries. E-mail messages include transit handling envelope and trace information in the form of structured fields which are not stripped after messages are delivered, leaving a detailed record of e-mail transactions.  A detailed header analysis can be used to map the networks traversed by messages, including information on the messaging software and patching policies of clients and gateways, etc. Cyber forensic e-mail analysis is employed to collect credible evidence to bring criminals to justice. This paper projects the need for e-mail forensic investigation and lists various methods and tools used for its realization. A detailed header analysis of a multiple tactic spoofed e-mail message is carried out in this paper. It also discusses various possibilities for detection of spoofed headers and identification of its originator. Further, difficulties that may be faced by investigators during forensic investigation of an e-mail message have been discussed along with their possible solutions.

  19. Numerical simulation for i - ii type of distribution header throttle

    International Nuclear Information System (INIS)

    Yuheng, Feng; Wenjun, Hu; Xuedong, Qiao; Zhifeng, Hou

    2009-01-01

    In the simulation of distribution header throttle structure, using the computational fluid dynamic code-CFX, compared with experiment, the reasons of error is discussed and the reliability of this simulation is proved. Authors have checked same types of calculations, particularly introduced the relationship between CFD and experiment. The results will be theoretic base and reference

  20. Transport of nanoparticles in a temperature gradient

    Science.gov (United States)

    Putnam, Shawn; Cahill, David

    2006-03-01

    Thermodiffusion, mass transport in a temperature gradient, is commonly characterized by either the thermodiffusion coefficient DT or the Soret coefficient ST; e.g., at low particle concentration c, the particle flux of a colloidal suspension subjected to a temperature gradient ∇T is J=- cDT∇T-Dc∇c, where Dc is the diffusion coefficient and the Soret coefficient is ST= DT/Dc. We present our measured DT data for aqueous suspensions of charged polystyrene spheres, alumina nanoparticles, and globular proteins of lysozyme. Special emphasis is given to our published work on charged polystyrene spheres with different surface functionalities. For example, in solutions with large concentrations of monovalent salts, 100 mM, DT for 26 nm spheres with carboxyl functionality can be varied within the range -0.9 x10^- 7 cm^2 s-1 K-1 protein solutions of lysozyme.

  1. Dose surveys in two digital mammography units using DICOM headers

    International Nuclear Information System (INIS)

    Tsalafoutas, I.; Michalaki, C.; Papagiannopoulou, C.; Efstathopoulos, E.

    2012-01-01

    Background and objective: Digital mammography units store images in DICOM format. Thus, data regarding the acquisition parameters are available within DICOM headers, including among others, the anode/filter combination, tube potential and tube current exposure time product, compressed breast thickness, entrance surface air kerma (ESAK) and mean glandular dose (MGD). However, manual extraction of these data for the verification of the displayed values' accuracy and for dose survey purposes is time consuming. Our objective was to develop a method that enables the automation of such procedures. Materials and methods: Two hundred mammographic examinations (800 mammograms) performed in two digital units (GE, Essential) were recorded on CD-roms. Using appropriate software (DICOM Info Extractor) all dose related DICOM headers were extracted into a Microsoft Excel based spreadsheet, containing embedded algorithms for the calculation of ESAK and MGD according to Dance et al (Phys. Med. Biol. 45, 2000) methodology. Results: The ESAK and MGD values stored in the DICOM headers were compared with those calculated and in most cases were within ±10%. The basic difference among the two mammographic units is that, the older one calculates MGD assuming a breast composition 50% glandular-50% adipose tissue, while the newer one calculates the actual breast glandularity and stores this value in a DICOM header. The average MGD values were 1.21 mGy and 1.38 mGy, respectively. Conclusion: For the units studied, the ESAK and MGD values stored in DICOM headers are reliable. Utilizing tools for their automatic extraction provides an easy way to perform dose surveys. (authors)

  2. Two-phase refrigerant distribution in a combining/dividing header of a brazed aluminum evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nae Hyun; Byun, Ho Won; Go, Min Geon [School of Mechanical System Engineering, Incheon National University, Incheon (Korea, Republic of)

    2016-12-15

    For a brazed aluminum evaporator, it is very important to distribute the refrigerant (especially the liquid) evenly into each channel. If not, the liquid-deficient channel will be soon dry, and reduce the thermal performance of the evaporator. In this study, tests were conducted for a two pass evaporator having 10 combing channels and 14 dividing channels. Both lower and upper header configurations were considered. Effects of mass flux or vapor quality on flow distribution in the combining/dividing header were investigated. Data are also compared with those obtained from the header having 12 dividing channels. In the lower combining/dividing header, the effect of dividing header length on liquid distribution is different based on vapor quality. The centrifugal force, whose strength depends on header length and vapor quality, appears to play a significant role on flow distribution. In the upper combining/dividing header, the flow distribution is better for the header having shorter header length. The reason was attributed to more uniform height of the liquid pool, which is formed by the drained liquid film from top of the header. The effects of mass flux or vapor quality on flow distribution are also discussed.

  3. Measurement of temperature fluctuations and anomalous transport ...

    Indian Academy of Sciences (India)

    Coulomb collisions in a magnetised plasma give rise to electrical resistivity and particle diffusion across the magnetic field. This diffusion process is known as classical trans- port and can be calculated exactly. For the curved magnetic geometry of a tokamak, the collisional transport is termed as neoclassical transport.

  4. The Effect of Temperature on Moisture Transport in Concrete.

    Science.gov (United States)

    Wang, Yao; Xi, Yunping

    2017-08-09

    Most concrete structures and buildings are under temperature and moisture variations simultaneously. Thus, the moisture transport in concrete is driven by the moisture gradient as well as the temperature gradient. This paper presents an experimental approach for determining the effect of different temperature gradients on moisture distribution profiles in concrete. The effect of elevated temperatures under isothermal conditions on the moisture transport was also evaluated, and found not to be significant. The non-isothermal tests show that the temperature gradient accelerates the moisture transport in concrete. The part of increased moisture transfer due to the temperature gradient can be quantified by a coupling parameter D HT , which can be determined by the present test data. The test results indicated that D HT is not a constant but increases linearly with the temperature variation. A material model was developed for D HT based on the experimental results obtained in this study.

  5. Temperature-dependent gas transport and its correlation with kinetic ...

    Indian Academy of Sciences (India)

    dependent gas transport and its correlation with kinetic diameter in polymer nanocomposite membrane. N K ACHARYA ... For the first time, the permeability and selectivity for nanocomposite membrane are reported as a function of temperature.

  6. Shape optimized headers and methods of manufacture thereof

    Science.gov (United States)

    Perrin, Ian James

    2013-11-05

    Disclosed herein is a shape optimized header comprising a shell that is operative for collecting a fluid; wherein an internal diameter and/or a wall thickness of the shell vary with a change in pressure and/or a change in a fluid flow rate in the shell; and tubes; wherein the tubes are in communication with the shell and are operative to transfer fluid into the shell. Disclosed herein is a method comprising fixedly attaching tubes to a shell; wherein the shell is operative for collecting a fluid; wherein an internal diameter and/or a wall thickness of the shell vary with a change in pressure and/or a change in a fluid flow rate in the shell; and wherein the tubes are in communication with the shell and are operative to transfer fluid into the shell.

  7. Evaluating two process scale chromatography column header designs using CFD.

    Science.gov (United States)

    Johnson, Chris; Natarajan, Venkatesh; Antoniou, Chris

    2014-01-01

    Chromatography is an indispensable unit operation in the downstream processing of biomolecules. Scaling of chromatographic operations typically involves a significant increase in the column diameter. At this scale, the flow distribution within a packed bed could be severely affected by the distributor design in process scale columns. Different vendors offer process scale columns with varying design features. The effect of these design features on the flow distribution in packed beds and the resultant effect on column efficiency and cleanability needs to be properly understood in order to prevent unpleasant surprises on scale-up. Computational Fluid Dynamics (CFD) provides a cost-effective means to explore the effect of various distributor designs on process scale performance. In this work, we present a CFD tool that was developed and validated against experimental dye traces and tracer injections. Subsequently, the tool was employed to compare and contrast two commercially available header designs. © 2014 American Institute of Chemical Engineers.

  8. Phishtest: Measuring the Impact of Email Headers on the Predictive Accuracy of Machine Learning Techniques

    Science.gov (United States)

    Tout, Hicham

    2013-01-01

    The majority of documented phishing attacks have been carried by email, yet few studies have measured the impact of email headers on the predictive accuracy of machine learning techniques in detecting email phishing attacks. Research has shown that the inclusion of a limited subset of email headers as features in training machine learning…

  9. RObust header compression (ROHC) performance for multimedia transmission over 3G/4G wireless networks

    DEFF Research Database (Denmark)

    Fitzek, Frank; Rein, S.; Seeling, P.

    2005-01-01

    Robust Header Compression (ROHC) has recently been proposed to reduce the large protocol header overhead when transmitting voice and other continuous meadi over IP based control stacks in wireless networks. In this paper we evaluate the real-time transmission of GSM encoded voice and H. 26L encod...

  10. Low temperature current transport of Sn-GaAs contacts

    NARCIS (Netherlands)

    Heida, J; Wees, B.J. van; Bakker, Siemon; Klapwijk, T.M.; Alphenaar, B.W.

    1993-01-01

    We measure low temperature current transport properties of superconducting Sn contacts to p+-GaAs. For contacts alloyed at 450-degrees-C, the current-voltage characteristics show a strong dependence on alloying time. The critical temperature of Sn near the superconductor-semiconductor interface

  11. Temperature driven transport of gold nanoparticles physisorbed inside carbon nanotubes

    DEFF Research Database (Denmark)

    Schoen, P.A.E.; Poulikakos, D.; Walther, Jens Honore

    2006-01-01

    We use molecular dynamics simulations to demonstrate the temperature driven mass transport of solid gold nanoparticles, physisorbed inside carbon nanotubes (CNTs). Our results indicate that the nanoparticle experiences a guided motion, in the direction opposite to the direction of the temperature...... affects the nanoparticle motion along the carbon lattice....

  12. Temperature dependent charge transport in poly(3-hexylthiophene) diodes

    Science.gov (United States)

    Rahaman, Abdulla Bin; Sarkar, Atri; Banerjee, Debamalya

    2018-04-01

    In this work, we present charge transport properties of poly(3-hexylthiophene) (P3HT) diodes under dark conditions. Temperature dependent current-voltage (J-V) characteristics shows that charge transport represents a transition from ohomic to trap limited current. The forward current density obeys a power law J˜Vm, m>2 represents the space charge limited current region in presence of traps within the band gap. Frequency dependent conductivity has been studied in a temperature range 150K-473K. The dc conductivity values show Arrhenius like behavior and it gives conductivity activation energy 223 meV. Temperature dependent conductivity indicates a thermodynamic transition of our system.

  13. Damage distribution and remnant life assessment of a super-heater outlet header used for long time

    Energy Technology Data Exchange (ETDEWEB)

    Hiroyuki, Okamura [Science Univ. of Tokyo (Japan); Ryuichi, Ohotani [Kyoto Univ. (Japan); Kazuya, Fujii [Japan Power Engineering and Inspection Corp., Tokyo (Japan); Masashi, Nakashiro; Fumio, Takemasa; Hideo, Umaki; Tomiyasu, Masumura [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1998-11-01

    This paper presents the results of investigation on evaluating damage distribution to base metals and welded joints in the thickness direction and evaluate damage on ligaments. Thick wall tested sample was the superheater outlet header component long term serviced in high pressure and temperature condition in thermal power plant. The simulate unused steel of component material was made from sample by suitable heat treatment, and the extent of damage was assessed based on a comparison of nondestructive and destructive test results between simulate unused and aged samples. Damage evaluation was also made by FEM structural stress analysis. (orig./MM)

  14. Directional transport of droplets on wettability patterns at high temperature

    Science.gov (United States)

    Huang, Shuai; Yin, Shaohui; Chen, Fengjun; Luo, Hu; Tang, Qingchun; Song, Jinlong

    2018-01-01

    Directional transport of liquid has attracted increasing interest owing to its potential of application in lab-on-a-chip, microfluidic devices and thermal management technologies. Although numerous strategies have been developed to achieve directional transport of liquid at low temperature, controlling the directional transport of liquid at high temperature remains to be a challenging issue. In this work, we reported a novel strategy in which different parts of droplet contacted with surface with different wettability patterns, resulting in a discrepant evaporative vapor film to achieve the directional transport of liquid. The experimental results showed that the state of the liquid on wettability patterned surface gradually changed from contact boiling to Leidenfrost state with the increase of substrate temperature Ts, and liquid on superhydrophilic surface was in composite state of contact boiling and Leidenfrost when Ts was higher than 200 °C. Inspired by the different evaporation states of droplet on the wettability boundary, controlling preferential motion of droplets was observed at high temperature. By designing a surface with wettability pattern on which superhydrophobic region and superhydrophilic region are alternately arranged, a controlled directional transport of droplet can be achieved at high temperature.

  15. Temperature dependence of electronic transport property in ferroelectric polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, X.L.; Wang, J.L., E-mail: jlwang@mail.sitp.ac.cn; Tian, B.B.; Liu, B.L.; Zou, Y.H.; Wang, X.D.; Sun, S.; Sun, J.L., E-mail: jlsun@mail.sitp.ac.cn; Meng, X.J.; Chu, J.H.

    2014-10-15

    Highlights: • The ferroelectric polymer was fabricated by Langmuir–Blodgett method. • The electrons as the dominant injected carrier were conformed in the ferroelectric polymer films. • The leakage current conduction mechanisms in ferroelectric polymer were investigated. - Abstract: The leakage current mechanism of ferroelectric copolymer of polyvinylidene fluoride with trifluoroethylene prepared by Langmuir–Blodgett was investigated in the temperature range from 100 K to 350 K. The electron as the dominant injected carrier was observed in the ferroelectric copolymer films. The transport mechanisms in copolymer strongly depend on the temperature and applied voltage. From 100 K to 200 K, Schottky emission dominates the conduction. With temperature increasing, the Frenkel–Poole emission instead of the Schottky emission to conduct the carrier transport. When the temperature gets to 260 K, the leakage current becomes independent of temperature, and the space charge limited current conduction was observed.

  16. Atlantoaxial instability after a header in an amateur soccer player.

    Science.gov (United States)

    Werle, Stephan; Nahleh, Kais Abu; Boehm, Heinrich

    2015-03-01

    Case report and literature review. To report a unique case of atlantoaxial instability after a header in a 37-year-old amateur soccer player and to discuss the injury pattern in relation to the impact of heading. Although there is potential for cervical spine injuries, the rates in soccer are low compared with other contact or even noncontact sports. No cases of acute post-traumatic atlantoaxial instability after heading have ever been reported in a MEDLINE-listed article. A 37-year-old male soccer player experienced acute upper neck pain and transient quadriplegia after heading a long-distance ball on 2 occasions during a match. Imaging revealed atlantoaxial instability. Persistent neurological symptoms on conservative treatment led to his referral to our department. The considerable instability required surgical intervention. Transarticular C1-C2 fixation and posterior fusion with structural iliac crest grafting were performed. The procedure immediately led to complete relief of the neurological symptoms. After an uneventful postoperative recovery, follow-up at 9 months revealed solid fusion. The patient remained symptom free. Heading the ball in soccer can potentially lead to atlantoaxial instability. Ligamentous damage can theoretically be caused by anteriorly directed and rotational overload. However, the causative mechanism remains unclear. Diagnostic workup should consider dynamic imaging in players with transient neurological symptoms after minor trauma to the cervical spine. N/A.

  17. Temperature dependence of transport coefficients of 'simple liquid ...

    African Journals Online (AJOL)

    ... has been investigated. The study carried out at two densities, r* = 0.60 and r* = 0.95. Result shows erratic variations of the shear viscosity in the two lattices structures. KeyWords: Temperature effect, face centred, simple cubic, transport properties, simple liquid. [Global Jnl Pure & Appl. Sci. Vol.9(3) 2003: 403-406] ...

  18. Synthesis, structure and low temperature study of electric transport ...

    Indian Academy of Sciences (India)

    Synthesis, structure and low temperature study of electric transport and magnetic properties of GdSr2MnCrO7. Devinder ... Keywords. Chemical synthesis; X-ray diffraction; electrical properties; magnetic properties. Abstract. The layered perovskite oxide, GdSr2MnCrO7, has been prepared by the standard ceramic method.

  19. Low-temperature localization in the transport properties of self ...

    Indian Academy of Sciences (India)

    Transport properties; scattering mechanisms; low temperature localization. 1. Introduction. The investigation on mixed-valent manganites with per- ovskite structure is on run for the last two decades. Specially, the studies on the hole doped manganites, La1−δAδMnO3. (A = divalent atom) still demands special attention ...

  20. Researching of Covert Timing Channels Based on HTTP Cache Headers in Web API

    Directory of Open Access Journals (Sweden)

    Denis Nikolaevich Kolegov

    2015-12-01

    Full Text Available In this paper, it is shown how covert timing channels based on HTTP cache headers can be implemented using different Web API of Google Drive, Dropbox and Facebook  Internet services.

  1. All-optical 2-bit header recognition and packet switching using polarization bistable VCSELs.

    Science.gov (United States)

    Hayashi, Daisuke; Nakao, Kazuya; Katayama, Takeo; Kawaguchi, Hitoshi

    2015-04-06

    We propose and evaluate an all-optical 2-bit header recognition and packet switching method using two 1.55-µm polarization bistable vertical-cavity surface-emitting lasers (VCSELs) and three optical switches. Polarization bistable VCSELs acted as flip-flop devices by using AND-gate operations of the header and set pulses, together with the reset pulses. Optical packets including 40-Gb/s non-return-to-zero pseudo-random bit-sequence payloads were successfully sent to one of four ports according to the state of two bits in the headers with a 4-bit 500-Mb/s return-to-zero format. The input pulse powers were 17.2 to 31.8 dB lower than the VCSEL output power. We also examined an extension of this method to multi-bit header recognition and packet switching.

  2. Orthogonal transformations for change detection, Matlab code (ENVI-like headers)

    DEFF Research Database (Denmark)

    2007-01-01

    Matlab code to do (iteratively reweighted) multivariate alteration detection (MAD) analysis, maximum autocorrelation factor (MAF) analysis, canonical correlation analysis (CCA) and principal component analysis (PCA) on image data; accommodates ENVI (like) header files.......Matlab code to do (iteratively reweighted) multivariate alteration detection (MAD) analysis, maximum autocorrelation factor (MAF) analysis, canonical correlation analysis (CCA) and principal component analysis (PCA) on image data; accommodates ENVI (like) header files....

  3. 40 Gbit/s NRZ Packet-Length Insensitive Header Extraction for Optical Label Switching Networks

    DEFF Research Database (Denmark)

    Seoane, Jorge; Kehayas, E; Avramopoulos, H.

    2006-01-01

    A simple method for 40 Gbit/s NRZ header extraction based on envelope detection for optical label switching networks is presented. The scheme is insensitive to packet length and spacing and can be single-chip integrated cost-effectively......A simple method for 40 Gbit/s NRZ header extraction based on envelope detection for optical label switching networks is presented. The scheme is insensitive to packet length and spacing and can be single-chip integrated cost-effectively...

  4. Anomalous plasma transport due to electron temperature gradient instability

    International Nuclear Information System (INIS)

    Tokuda, Sinji; Ito, Hiroshi; Kamimura, Tetsuo.

    1979-01-01

    The collisionless drift wave instability driven by an electron temperature inhomogeneity (electron temperature gradient instability) and the enhanced transport processes associated with it are studied using a two-and-a-half dimensional particle simulation code. The simulation results show that quasilinear diffusion in phase space is an important mechanism for the saturation of the electron temperature gradient instability. Also, the instability yields particle fluxes toward the hot plasma regions. The heat conductivity of the electron temperature perpendicular to the magnetic field, T sub(e'), is not reduced by magnetic shear but remains high, whereas the heat conductivity of the parallel temperature, T sub(e''), is effectively reduced, and the instability stabilized. (author)

  5. Brittle fracture tests at low temperature for transport cask materials

    International Nuclear Information System (INIS)

    Kosaki, Akio; Ito, Chihiro; Arai, Taku; Saegusa, Toshiari

    1993-01-01

    The IAEA Regulations for the Safe Transport of Radioactive Material were revised in 1985, and brittle fracture assessment at low temperature for transport packages are now required. This report discusses the applicability of the actual method for brittle fracture assessment of type-B transport cask materials used in JAPAN. The necessity of brittle fracture assessment at low temperature was estimated for each material of type-B transport casks used in Japan and the applicability was investigated. Dynamic fracture toughness values, K Id (J Id ), and RT NDT values of Low-Mn Carbon Steels, that are SA 350 Gr.LF1 Modify and SA 516 Gr.70 material which used in type-B transport cask body, were also obtained to check whether or not an easier and conventional test method, that prescribed in ASME CODE SECTION III, can be substituted for the dynamic fracture test method. And for bolt materials, which include 1.8Ni-0.8Cr-0.3Mo Carbon Steel and type 630 H Stainless Steel, toughness data were obtained for reference. (J.P.N.)

  6. Entropy production and transport in relation to Tokamak temperature profiles

    International Nuclear Information System (INIS)

    Martinell, J.J.; Almaguer, J.A.; Herrera, J.J.E.

    1992-01-01

    The consequences of using the idea of entropy production rate minimization are examined in relation to the shape of radial temperature profiles and the scaling of transport coefficients with temperature in Tokamak discharges. This is done under the assumption that physical processes occur in such a way as to produce relaxed states where an extremal of some relevant quantity (in this case the entropy production) is obtained. The conditions under which the temperature profiles adopt the Gaussian-like shapes observed in Tokamak plasmas are studied. This is possible only for certain scalings of the thermal conductivity with temperature favouring certain models of anomalous transport against others. These results are also dependent on whether or not the current density profile is assumed to be determined by the temperature profile, as in Ohmically heated discharges with constant electric field. In the former case an anomalous electrical resistivity is needed in order to obtain the correct temperature profiles for known models of anomalous thermal conductivity. When the current density is an independent function of radius the electrical resistivity can be classical, and for the thermal diffusivity this approach favours the models based on magnetic fluctuations exhibiting the Ohkawa scaling, as well as a model that employs profile consistency in its derivations. These cases should be relevant to discharges with auxiliary heating. (Author)

  7. Transport lattice models of heat transport in skin with spatially heterogeneous, temperature-dependent perfusion

    Directory of Open Access Journals (Sweden)

    Martin Gregory T

    2004-11-01

    Full Text Available Abstract Background Investigation of bioheat transfer problems requires the evaluation of temporal and spatial distributions of temperature. This class of problems has been traditionally addressed using the Pennes bioheat equation. Transport of heat by conduction, and by temperature-dependent, spatially heterogeneous blood perfusion is modeled here using a transport lattice approach. Methods We represent heat transport processes by using a lattice that represents the Pennes bioheat equation in perfused tissues, and diffusion in nonperfused regions. The three layer skin model has a nonperfused viable epidermis, and deeper regions of dermis and subcutaneous tissue with perfusion that is constant or temperature-dependent. Two cases are considered: (1 surface contact heating and (2 spatially distributed heating. The model is relevant to the prediction of the transient and steady state temperature rise for different methods of power deposition within the skin. Accumulated thermal damage is estimated by using an Arrhenius type rate equation at locations where viable tissue temperature exceeds 42°C. Prediction of spatial temperature distributions is also illustrated with a two-dimensional model of skin created from a histological image. Results The transport lattice approach was validated by comparison with an analytical solution for a slab with homogeneous thermal properties and spatially distributed uniform sink held at constant temperatures at the ends. For typical transcutaneous blood gas sensing conditions the estimated damage is small, even with prolonged skin contact to a 45°C surface. Spatial heterogeneity in skin thermal properties leads to a non-uniform temperature distribution during a 10 GHz electromagnetic field exposure. A realistic two-dimensional model of the skin shows that tissue heterogeneity does not lead to a significant local temperature increase when heated by a hot wire tip. Conclusions The heat transport system model of the

  8. Potential impact of high temperature superconductors on maglev transportation

    Energy Technology Data Exchange (ETDEWEB)

    Hull, J.R.

    1992-02-01

    This report describes the potential impact that high-temperature superconductors (HTSs) may have on transportation by magnetically levitated vehicles. It is not intended as a planning document, but rather as an overview of potential HTS applications to magnetic-levitation (maglev) transportation. The present maglev program in the United States is summarized, and the present status of development of HTSs is described. Areas identified for possible impact on maglev technology are (1) liquid-nitrogen-cooled levitation magnets, (2) magnetic-field shielding of the passenger compartment, (3) superconducting magnetic energy storage for wayside power, (4) superconducting bearings for flywheel energy storage for wayside power, (5) downleads to continuously powered liquid-helium-cooled levitation magnets, and (6) liquid-hydrogen-cooled levitation magnets and linear motor propulsion windings. Major technical issues that remain to be resolved for the use of HTSs in maglev applications include thermal magnetic stability, mechanical properties, and critical current density at liquid-nitrogen temperatures.

  9. Phonon hydrodynamics for nanoscale heat transport at ordinary temperatures

    Science.gov (United States)

    Guo, Yangyu; Wang, Moran

    2018-01-01

    The classical Fourier's law fails in extremely small and ultrafast heat conduction even at ordinary temperatures due to strong thermodynamic nonequilibrium effects. In this work, a macroscopic phonon hydrodynamic equation beyond Fourier's law with a relaxation term and nonlocal terms is derived through a perturbation expansion to the phonon Boltzmann equation around a four-moment nonequilibrium solution. The temperature jump and heat flux tangential retardant boundary conditions are developed based on the Maxwell model of the phonon-boundary interaction. Extensive steady-state and transient nanoscale heat transport cases are modeled by the phonon hydrodynamic model, which produces quantitative predictions in good agreement with available phonon Boltzmann equation solutions and experimental results. The phonon hydrodynamic model provides a simple and elegant mathematical description of non-Fourier heat conduction with a clear and intuitive physical picture. The present work will promote deeper understanding and macroscopic modeling of heat transport in extreme states.

  10. Structural disorder and electron transport in graphene at low temperatures

    Science.gov (United States)

    Bobenko, N. G.; Egorushkin, V. E.; Melnikova, N. V.; Ponomarev, A. N.; Belosludtseva, A. A.; Barkalov, L. D.

    2017-12-01

    A theoretical study of electron transport characteristics of metalized epitaxial graphene with impurities and structural inhomogeneous of the short-range order type was performed. The electron relaxation time, mean free path, and diffusion coefficient were calculated and shown to be of the same order of magnitude as the corresponding values for phonon characteristics. It means that electron scattering on the short-range ordered domains has to be taken into account, especially at low temperatures when it may dominate phonon scattering.

  11. Low-temperature localization in the transport properties of self ...

    Indian Academy of Sciences (India)

    293–298. c Indian Academy of Sciences. Low-temperature localization in the transport properties of self-doped. La0.9Mn0.98Zn0.02O3. K DE1 and S DAS2,∗. 1Neotia Institute of Technology, Management and Science, Jhinga 743 368, India. 2Department of Electronics and Communication Engineering, Guru Ghasidas ...

  12. Electronic Monitoring Of Storage And Transport Temperatures Of ...

    African Journals Online (AJOL)

    change in locations, type of carriage and storage. The data logger was sent back after the vaccination campaign and data were retrieved using a Tinytag Explorer software. The results showed that I-2 vaccine was stored and transported in temperatures within the range of 1.06ºC to 28.77ºC (average17.50ºC). The storage ...

  13. Secured Hash Based Burst Header Authentication Design for Optical Burst Switched Networks

    Science.gov (United States)

    Balamurugan, A. M.; Sivasubramanian, A.; Parvathavarthini, B.

    2017-12-01

    The optical burst switching (OBS) is a promising technology that could meet the fast growing network demand. They are featured with the ability to meet the bandwidth requirement of applications that demand intensive bandwidth. OBS proves to be a satisfactory technology to tackle the huge bandwidth constraints, but suffers from security vulnerabilities. The objective of this proposed work is to design a faster and efficient burst header authentication algorithm for core nodes. There are two important key features in this work, viz., header encryption and authentication. Since the burst header is an important in optical burst switched network, it has to be encrypted; otherwise it is be prone to attack. The proposed MD5&RC4-4S based burst header authentication algorithm runs 20.75 ns faster than the conventional algorithms. The modification suggested in the proposed RC4-4S algorithm gives a better security and solves the correlation problems between the publicly known outputs during key generation phase. The modified MD5 recommended in this work provides 7.81 % better avalanche effect than the conventional algorithm. The device utilization result also shows the suitability of the proposed algorithm for header authentication in real time applications.

  14. Collective excitations and low temperature transport properties of bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Chudzinski, Piotr; Giamarchi, Thierry [DPMC-MaNEP, University of Geneva (Switzerland)

    2011-07-01

    We examine the influence of collective excitations on several transport coefficients (conductivity, magneto-optical conductivity, Nernst effect) for semimetal, bismuth. A longstanding problem of the transport coefficients in this material is the fact that their amplitude and temperature dependences do not obey naive Fermi liquid expectations. For the conductivity, we show that at high temperatures Baber scattering is able to explain quantitatively the DC resistivity experiments, while at low temperatures many-body effects need to be introduced to explain qualitative deviations from the standard T{sup 2} behavior. An atypical feature in magneto-optical conductivity is predicted. The Nernst effect in bismuth was recently the subject of several contradictory theoretical studies. We show that a plasmon physics allows to get a coherent picture and leads to very large values of the Nernst signal. We use two complementary methods- Feynmann diagrams and field theory (Hubbard-Stratonovich transformation). These methods, which go beyond the standard RPA study, allow to set a limit to the validity of our model and to make contact with the other family of semimetals, 1T-TiSe{sub 2}, also subject of recent experimental interest. To complete the discussion of semimetals, we also study the case of graphite.

  15. RObust header compression (ROHC) performance for multimedia transmission over 3G/4G wireless networks

    DEFF Research Database (Denmark)

    Fitzek, Frank; Rein, S.; Seeling, P.

    2005-01-01

    Robust Header Compression (ROHC) has recently been proposed to reduce the large protocol header overhead when transmitting voice and other continuous meadi over IP based control stacks in wireless networks. In this paper we evaluate the real-time transmission of GSM encoded voice and H. 26L encod...... transmission we examine the impact of ROHC on the consumed bandwidth. We find that the bandwidth asvings with ROHC depend on the quantization scale used for the video encoding and the video content and ranges between 5-40% for typical scenarios....

  16. Design and Evaluation of IP Header Compression for Cellular-Controlled P2P Networks

    DEFF Research Database (Denmark)

    Madsen, T.K.; Zhang, Qi; Fitzek, F.H.P.

    2007-01-01

    In this paper we advocate to exploit terminal cooperation to stabilize IP communication using header compression. The terminal cooperation is based on direct communication between terminals using short range communication and simultaneously being connected to the cellular service access point....... The short range link is than used to provide first aid information to heal the decompressor state of the neighboring node in case of a packet loss on the cellular link. IP header compression schemes are used to increase the spectral and power efficiency loosing robustness of the communication compared...

  17. Temperature-dependent transport properties of FeRh

    Science.gov (United States)

    Mankovsky, S.; Polesya, S.; Chadova, K.; Ebert, H.; Staunton, J. B.; Gruenbaum, T.; Schoen, M. A. W.; Back, C. H.; Chen, X. Z.; Song, C.

    2017-04-01

    The finite-temperature transport properties of FeRh compounds are investigated by first-principles density-functional-theory-based calculations. The focus is on the behavior of the longitudinal resistivity with rising temperature, which exhibits an abrupt decrease at the metamagnetic transition point, T =Tm , between ferro- and antiferromagnetic phases. A detailed electronic structure investigation for T ≥0 K explains this feature and demonstrates the important role of (i) the difference of the electronic structure at the Fermi level between the two magnetically ordered states and (ii) the different degree of thermally induced magnetic disorder in the vicinity of Tm, giving different contributions to the resistivity. To support these conclusions, we also describe the temperature dependence of the spin-orbit-induced anomalous Hall resistivity and Gilbert damping parameter. For the various response quantities considered, the impact of thermal lattice vibrations and spin fluctuations on their temperature dependence is investigated in detail. Comparison with corresponding experimental data shows, in general, very good agreement.

  18. Study on temperature-dependent carrier transport for bilayer graphene

    Science.gov (United States)

    Liu, Yali; Li, Weilong; Qi, Mei; Li, Xiaojun; Zhou, Yixuan; Ren, Zhaoyu

    2015-05-01

    In order to investigate the temperature-dependent carrier transport property of the bilayer graphene, graphene films were synthesized on Cu foils by a home-built chemical vapor deposition (CVD) with C2H2. Samples regularity, transmittance (T) and layer number were analyzed by transmission electron microscope (TEM) images, transmittance spectra and Raman spectra. Van Der Pauw method was used for resistivity measurements and Hall measurements at different temperatures. The results indicated that the sheet resistance (Rs), carrier density (n), and mobility (μ) were 1096.20 Ω/sq, 0.75×1012 cm-2, and 7579.66 cm2 V-1 s-1 at room temperature, respectively. When the temperature increased from 0 °C to 240 °C, carrier density (n) increased from 0.66×1012 cm-2 to 1.55×1012 cm-2, sheet resistance (Rs) decreased from 1215.55 Ω/sq to 560.77 Ω/sq, and mobility (μ) oscillated around a constant value 7773.99 cm2 V-1 s-1. The decrease of the sheet resistance (Rs) indicated that the conductive capability of the bilayer graphene film increased with the temperature. The significant cause of the increase of carrier density (n) was the thermal activation of carriers from defects and unconscious doping states. Because the main influence on the carrier mobility (μ) was the lattice defect scattering and a small amount of impurity scattering, the carrier mobility (μ) was temperature-independent for the bilayer graphene.

  19. Providing integrity, authenticity, and confidentiality for header and pixel data of DICOM images.

    Science.gov (United States)

    Al-Haj, Ali

    2015-04-01

    Exchange of medical images over public networks is subjected to different types of security threats. This has triggered persisting demands for secured telemedicine implementations that will provide confidentiality, authenticity, and integrity for the transmitted images. The medical image exchange standard (DICOM) offers mechanisms to provide confidentiality for the header data of the image but not for the pixel data. On the other hand, it offers mechanisms to achieve authenticity and integrity for the pixel data but not for the header data. In this paper, we propose a crypto-based algorithm that provides confidentially, authenticity, and integrity for the pixel data, as well as for the header data. This is achieved by applying strong cryptographic primitives utilizing internally generated security data, such as encryption keys, hashing codes, and digital signatures. The security data are generated internally from the header and the pixel data, thus a strong bond is established between the DICOM data and the corresponding security data. The proposed algorithm has been evaluated extensively using DICOM images of different modalities. Simulation experiments show that confidentiality, authenticity, and integrity have been achieved as reflected by the results we obtained for normalized correlation, entropy, PSNR, histogram analysis, and robustness.

  20. Simulation of neuro-fuzzy model for optimization of combine header setting

    Directory of Open Access Journals (Sweden)

    S Zareei

    2016-09-01

    Full Text Available Introduction The noticeable proportion of producing wheat losses occur during production and consumption steps and the loss due to harvesting with combine harvester is regarded as one of the main factors. A grain combines harvester consists of different sets of equipment and one of the most important parts is the header which comprises more than 50% of the entire harvesting losses. Some researchers have presented regression equation to estimate grain loss of combine harvester. The results of their study indicated that grain moisture content, reel index, cutter bar speed, service life of cutter bar, tine spacing, tine clearance over cutter bar, stem length were the major parameters affecting the losses. On the other hand, there are several researchswhich have used the variety of artificial intelligence methods in the different aspects of combine harvester. In neuro-fuzzy control systems, membership functions and if-then rules were defined through neural networks. Sugeno- type fuzzy inference model was applied to generate fuzzy rules from a given input-output data set due to its less time-consuming and mathematically tractable defuzzification operation for sample data-based fuzzy modeling. In this study, neuro-fuzzy model was applied to develop forecasting models which can predict the combine header loss for each set of the header parameter adjustments related to site-specific information and therefore can minimize the header loss. Materials and Methods The field experiment was conducted during the harvesting season of 2011 at the research station of the Faulty of Agriculture, Shiraz University, Shiraz, Iran. The wheat field (CV. Shiraz was harvested with a Claas Lexion-510 combine harvester. The factors which were selected as main factors influenced the header performance were three levels of reel index (RI (forward speed of combine harvester divided by peripheral speed of reel (1, 1.2, 1.5, three levels of cutting height (CH(25, 30, 35 cm, three

  1. Reducing CO2 emissions in temperature-controlled road transportation using the LDVRP model

    NARCIS (Netherlands)

    Stellingwerf, Helena M.; Kanellopoulos, Argyris; Vorst, van der Jack G.A.J.; Bloemhof, Jacqueline M.

    2018-01-01

    Temperature-controlled transport is needed to maintain the quality of products such as fresh and frozen foods and pharmaceuticals. Road transportation is responsible for a considerable part of global emissions. Temperature-controlled transportation exhausts even more emissions than ambient

  2. Transport and fluctuations in high temperature spheromak plasmas

    International Nuclear Information System (INIS)

    McLean, H.S.; Wood, R.D.; Cohen, B.I.; Hooper, E.B.; Hill, D.N.; Moller, J.M.; Romero-Talamas, C.; Woodruff, S.

    2006-01-01

    Higher electron temperature (T e >350 eV) and reduced electron thermal diffusivity (χ e 2 /s) is achieved in the Sustained Spheromak Physics Experiment (SSPX) by increasing the discharge current=I gun and gun bias flux=ψ gun in a prescribed manner. The internal current and q=safety factor profile derived from equilibrium reconstruction as well as the measured magnetic fluctuation amplitude can be controlled by programming the ratio λ gun =μ 0 I gun /ψ gun . Varying λ gun above and below the minimum energy eigenvalue=λ FC of the flux conserver (∇xB-vector=λ FC B-vector) varies the q profile and produces the m/n=poloidal/toroidal magnetic fluctuation mode spectrum expected from mode-rational surfaces with q=m/n. The highest T e is measured when the gun is driven with λ gun slightly less than λ FC , producing low fluctuation amplitudes ( e as T e increases, differing from Bohm or open field line transport models where χ e increases with T e . Detailed resistive magnetohydrodynamic simulations with the NIMROD code support the analysis of energy confinement in terms of the causal link with the q profile, magnetic fluctuations associated with low-order mode-rational surfaces, and the quality of magnetic surfaces

  3. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Science.gov (United States)

    2010-10-01

    ..., tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel Code... required by § 56.95-10 of this subchapter and PW-41 of section I of the ASME Boiler and Pressure Vessel... section I of the ASME Boiler and Pressure Vessel Code may be provided. [CGFR 68-82, 33 FR 18815, Dec. 18...

  4. Establishing Bedding Requirements during Transport and Monitoring Skin Temperature during Cold and Mild Seasons after Transport for Finishing Pigs.

    Science.gov (United States)

    McGlone, John; Johnson, Anna; Sapkota, Avi; Kephart, Rebecca

    2014-05-21

    The broad aim of this study was to determine whether bedding level in the transport trailer influenced pig performance and welfare. Specifically, the objective was to define the bedding requirements of pigs during transportation in commercial settings during cold and mild weather. Animals (n = 112,078 pigs on 572 trailers) used were raised in commercial finishing sites and transported in trailers to commercial processing plants. Dead on arrival (DOA), non-ambulatory (NA), and total dead and down (D&D) data were collected and skin surface temperatures of the pigs were measured by infrared thermography. Data were collected during winter (Experiment 1) and fall/spring (Experiment 2). Total D&D percent showed no interaction between bedding level and outside air temperature in any experiments. Average skin surface temperature during unloading increased with outside air temperature linearly in both experiments (P transport.

  5. Characteristics of flow distribution in compact parallel flow heat exchangers, part I: Typical inlet header

    International Nuclear Information System (INIS)

    Wang, Chi-Chuan; Yang, Kai-Shing; Tsai, Jhong-Syuan; Chen, Ing Youn

    2011-01-01

    This study experimentally and numerically investigates the single-phase flow into parallel flow heat exchangers with inlet and outlet rectangular headers having square cross section and 9 circular tubes. The effects of inlet flow condition, tube diameter, header size, area ratio, flow directions (Z and U-type), as well as the gravity are investigated. The experimental results indicate that flow distribution for U-type flow is more uniform than Z-type flow. Depending on the inlet volumetric flow rate, the flow ratio at the first several tubes can be lower than 50% of the last tube for Z-type arrangement, and this phenomenon becomes more and more pronounced with the rising velocity at the intake conduit. The mal-distribution can be eased via reducing the branching tube size or increasing the entrance settling distance at the intake conduit. It is found that the influence of gravity on mal-distribution is negligible and the mal-distribution is associated with the jet flow pattern. - Highlights: → The flow distribution into parallel flow heat exchangers with rectangular headers is examined. → The first several tubes may show only 50% flow rate of the last tube. → The mal-distribution becomes more severe with the rising velocity at the intake conduit. → The mal-distribution is mainly associated with the jet flow pattern. → Flow distribution is improved via smaller tubes or increasing the inlet distance at the intake conduit.

  6. TRMM Attitude and VIRS Packets and Header Record L1A V7 (TRMM_1A01) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The Level-1A Product file, ?1A01,? is a concatenation of Header record, Spacecraft Attitude packets, VIRS Housekeeping Data packets, VIRS Science Data packets, QACs,...

  7. TRMM Attitude and TMI Packets and Header Record L1A V7 (TRMM_1A11) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The Level-1A Product file, ?1A11,? is a concatenation of Header record, Spacecraft Attitude packets, TMI Housekeeping packets, TMI Science Data packets, QACs and an...

  8. Change of Muscle Activity as Well as Kinematic and Kinetic Parameters during Headers after Core Muscle Fatigue

    Directory of Open Access Journals (Sweden)

    Stephan Becker

    2017-01-01

    Full Text Available In soccer, headers are a tactical measure and influenced by numerous factors. The goal of this study was to identify whether changes in kinematics and muscular activity, especially of the head-stabilizing muscles, occur during headers when the core musculature is fatigued. In two subgroups, muscular activity (12 amateur players, age 23.6 ± 4.2 years and kinematics and dynamics (29 amateur players, age 23.7 ± 2.8 years were examined during straight headers on a pendulum header. Data were collected before and after the core muscles were fatigued by an exercise program. Telemetric surface EMG, 3D acceleration sensor, force plate, and video recordings were used. Under fatigue, the activity of M. erector spinae and M. rectus abdominis was significantly reduced in the preparation phase of the header. The activity of M. sternocleidomastoideus was significantly increased during the jump phase, and the hip extension angle during maximum arched body tension was significantly reduced under fatigue. Jumping height, acceleration force impulse, and linear head acceleration were also significantly reduced. We conclude that fatigue of the core muscles affects the motion technique of the header and the activity of the muscle groups stabilizing the head. Therefore, the necessity of specific training in soccer should be emphasized from a medical-preventive point of view.

  9. System and method for air temperature control in an oxygen transport membrane based reactor

    Science.gov (United States)

    Kelly, Sean M

    2016-09-27

    A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  10. System and method for temperature control in an oxygen transport membrane based reactor

    Science.gov (United States)

    Kelly, Sean M.

    2017-02-21

    A system and method for temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  11. Temperature-dependent ionic conductivity and transport properties ...

    Indian Academy of Sciences (India)

    Administrator

    the ionic transport. The observed high ionic conductivity is driven by local and segmental motions of the polymer chains, which assist the breaking and reforming of the bonds with the cation.13. A systematic study of LiClO4-doped PVA/mCellulose composite to understand the ion transport behaviour in polymers, the physical ...

  12. Temperature-dependent ionic conductivity and transport properties ...

    Indian Academy of Sciences (India)

    Administrator

    with dc conductivity (σdc) for different LiClO4 weight fractions (p) related to transport dimensionality was also focused. The highest ionic ... Percolation; transport properties; VTF model; ionic conductivity; Williams–Landel–Ferry. 1. Introduction ..... thermodynamic interaction parameter and composites are thermodynamically ...

  13. Development of High-Temperature Transport System for Molten Salt in Pyroprocessing

    International Nuclear Information System (INIS)

    Lee, Sung Ho; Kim, In Tae; Park, Sung Bin

    2014-01-01

    The electrorefining process, which is a key process in pyroprocessing, is composed of two parts, electrorefining to deposit a uranium with a solid cathode and electrowinning to co-deposit TRU and RE with a liquid cadmium cathode (LCC). As the electrorefining operation proceedes, TRU and RE are accumulated in electrolyte LiCl-KCl salt, and after the electrorefining process, the molten salt used in an electrorefining reactor should by transported to the next process, the electrowinning process, to recover U/TRU/RE; Thus, a molten salt transfer system by suction is now being developed. An apparatus for suction transport experiments was designed and constructed for the development of high- temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt. The feasibility of pyro-reprocessing has been demonstrated through many laboratory-scale experiments. In pyroprocessing, a eutectic LiCl-KCl salt was used as a liquid elextrolyte for a recovery of actinides. However, reliable transport technologies for these high temperature liquids have not yet been developed. A preliminary study on high-temperature transport technology for molten salt by suction is now being carried out. In this study, three different salt transport technologies (gravity, suction pump, and centrifugal pump) were investigated to select the most suitable method for molten salt transport. An apparatus for suction transport experiments was designed and installed for the development of high-temperature molten salt transport technology. Basic preliminary suction transport experiments were carried out using the prepared LiC-KCl eutectic salt at 500 .deg. C to observe the transport behavior of LiCl-KCl molten salt. In addition, a PRIDE salt transport system was designed and installed for an engineering-scale salt transport demonstration. Several types of suction transport experiments using molten salt (LiCl-KCl eutectics) for the development of a high-temperature

  14. Sea surface temperature and Ekman transport in the Persian Gulf

    Directory of Open Access Journals (Sweden)

    E. H.

    2002-12-01

    Full Text Available   The wind drift motion of the water which is produced by the stress of the wind exerted upon the surface of the ocean is described by Ekmans theory (1905. Using the mean monthly values for the wind stress and SST, seasonal Ekman transport for the Persian Gulf was computed and contoured. The geostrophic winds have combined with the SST to estimate the effect of cooling due to Ekman transport of colder northern waters and inflow from the Oman Sea. The monthly SST mainly obtained from the 10 10 grided data of Levitus atlas and Hormuz Cruis Experiment for 1997.   Analyses show a NW to SE Ekman transport due to wind stress and significant interannual variability of SST on sea surface in the Persian Gulf. The seasonal variation of SST shows a continental pattern due to severe interaction between the land and sea. But these variations somehow moderates because of Ekman transport in Persian Gulf.

  15. Design considerations for CRBRP heat transport system piping operating at elevated temperatures

    International Nuclear Information System (INIS)

    Pollono, L.P.; Mello, R.M.

    1979-01-01

    The heat transport system sodium piping for the Clinch River Breeder Reactor Plant (CRBRP) within the reactor containment building must withstand high temperatures for long periods of time. Each phase of the mechanical design process of the piping system is influenced by elevated temperature considerations which include material thermal creep effects, ratchetting caused by rapid temperature transients and stress relaxation, and material degradation effects. The structural design philosophy taken to design the CRBRP piping operating in a high temperature environment is described. The resulting design of the heat transport system piping is presented along with a discussion of special features that resulted from the elevated temperature considerations

  16. Adaptation of microorganisms and their transport systems to high temperatures

    NARCIS (Netherlands)

    Tolner, B; Poolman, B.; Konings, W.N

    1997-01-01

    Growth of Bacteria and Archaea has been observed at temperatures up to 95 and 110 degrees C, respectively. These thermophiles are adapted to environments of high temperature by changes in the membrane lipid composition, higher thermostabilities of the (membrane) proteins, higher turnover rates of

  17. Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells

    Energy Technology Data Exchange (ETDEWEB)

    James E. O' Brien

    2012-03-01

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

  18. Monitoring of temperature-critical transports through mobile vehicle-communication; Ueberwachung temperaturgefuehrter Transporte mit Hilfe mobiler Fahrzeugkommunikation

    Energy Technology Data Exchange (ETDEWEB)

    Erkens, E.; Kopfer, H. [Bremen Univ. (Germany). Lehrstuhl fuer Logistik; Fitsch, M.; Graeser, A. [Bremen Univ. (Germany). Inst. fuer Automatisierungstechnik

    2004-07-01

    This article introduces the upgrading of a communication system used in freight forwarding business with a module for the monitoring of temperature-critical transports. At first, the requirements for monitoring this type of transport are being developed. Afterwards the communication system wapLog is introduced, which is subject to the integration of the monitoring-module. The article concludes with the requirements of the underlaying technical architecture which has been derived from the demands of the temperature-critical goods as well as mobile vehicle communication. (orig.)

  19. Establishing Bedding Requirements during Transport and Monitoring Skin Temperature during Cold and Mild Seasons after Transport for Finishing Pigs

    Directory of Open Access Journals (Sweden)

    John McGlone

    2014-05-01

    Full Text Available The broad aim of this study was to determine whether bedding level in the transport trailer influenced pig performance and welfare. Specifically, the objective was to define the bedding requirements of pigs during transportation in commercial settings during cold and mild weather. Animals (n = 112,078 pigs on 572 trailers used were raised in commercial finishing sites and transported in trailers to commercial processing plants. Dead on arrival (DOA, non-ambulatory (NA, and total dead and down (D&D data were collected and skin surface temperatures of the pigs were measured by infrared thermography. Data were collected during winter (Experiment 1 and fall/spring (Experiment 2. Total D&D percent showed no interaction between bedding level and outside air temperature in any experiments. Average skin surface temperature during unloading increased with outside air temperature linearly in both experiments (P < 0.01. In conclusion, over-use of bedding may be economically inefficient. Pig skin surface temperature could be a useful measure of pig welfare during or after transport.

  20. Synthesis, structure and low temperature study of electric transport ...

    Indian Academy of Sciences (India)

    Abstract. The layered perovskite oxide, GdSr2MnCrO7, has been prepared by the standard ceramic method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group. I4/mmm. The electrical transport properties show that the phase is an electrical insulator and the ...

  1. Temperature dependent transport characteristics of graphene/n-Si diodes

    NARCIS (Netherlands)

    Parui, S.; Ruiter, R.; Zomer, P. J.; Wojtaszek, M.; van Wees, B. J.; Banerjee, T.

    2014-01-01

    Realizing an optimal Schottky interface of graphene on Si is challenging, as the electrical transport strongly depends on the graphene quality and the fabrication processes. Such interfaces are of increasing research interest for integration in diverse electronic devices as they are thermally and

  2. Temperature-dependent ionic conductivity and transport properties ...

    Indian Academy of Sciences (India)

    This paper presents the investigation on physicochemical properties and ionic conductivity of LiClO4-doped poly(vinyl alcohol) (PVA)/modified cellulose composites. The percolative behaviour of LiClO4 with dc conductivity (dc) for different LiClO4 weight fractions (p) related to transport dimensionality was also focused.

  3. Directional droplet transport at high temperature mediated by structural topography

    Science.gov (United States)

    Li, Jing; Hou, Youmin; Chaudhury, Manoj; Yao, Shuhuai; Wang, Zuankai

    2015-11-01

    Controlling droplet dynamics on textured surfaces is of significant importance for a broad range of applications. Despite extensive advances, our ability to control droplet dynamics at high temperature remains limited, in part due to the emergence of complex wetting states complicated by the phase change process at the triple-phase interfaces. When the temperature of the surface is above a critical temperature, a continuous vapor layer separates the droplet from the hot surface, greatly reducing the heat transfer between the droplet and hot surface. In this work, we show that two concurrent wetting states (Leidenfrost and contact boiling) can be manifested in a single droplet by simply manipulating the structural topography. As a result, droplet vectors automatically towards the boiling region that is associated with a large heat transfer efficiency between the liquid and solid. Coupled with a dynamic Leidenfrost model, we show experimentally and analytically that the droplet directional motion depends on the interplay between surface structure and its imposed thermal state. Our basic understanding and ability to control the droplet dynamics at high temperature would find many potential applications in high temperature systems such as spray cooling and fuel injection.

  4. Transport in the high temperature core of toroidal confinement systems

    International Nuclear Information System (INIS)

    Weiland, J.

    1994-01-01

    Recent theoretical and experimental results on confinement of hot plasmas in toroidal devices, particularly tokamaks, are discussed from general principal points of view and related to predictions from a toroidal drift wave model using a full transport matrix including off diagonal terms. A reactive fluid model corresponding to a two pole approximation of the kinetic response is used. This model has the ability to reproduce both adiabatic and isothermal limits of the perpendicular dynamics. 106 refs, 8 figs, 1 tab

  5. Daily Press Headers as a Reinforcement to Brand Identity in Spanish Sport Newspapers both Print and Online

    Directory of Open Access Journals (Sweden)

    Belén PUEBLA MARTÍNEZ

    2015-06-01

    Full Text Available Press headers are to daily newspapers the same as brands are to products. Because a newspaper is an object itself which also participates in a double designing process: from information and from product design; and in both cases this serves the same purpose, that the reader feels attracted and comes back for more every day. On that trip, which takes place either to the newsstand or to the computer, to become visible and unique is of paramount importance and the header is the element that best identifies not only the publication but also the tone of the language that the reader expects to find in it. This study intends to dive into the Spanish sport daily press headers, both print and digital, to establish how newspapers achieve their pretended brand identity.

  6. Asynchronous broadcast for ordered delivery between compute nodes in a parallel computing system where packet header space is limited

    Science.gov (United States)

    Kumar, Sameer

    2010-06-15

    Disclosed is a mechanism on receiving processors in a parallel computing system for providing order to data packets received from a broadcast call and to distinguish data packets received at nodes from several incoming asynchronous broadcast messages where header space is limited. In the present invention, processors at lower leafs of a tree do not need to obtain a broadcast message by directly accessing the data in a root processor's buffer. Instead, each subsequent intermediate node's rank id information is squeezed into the software header of packet headers. In turn, the entire broadcast message is not transferred from the root processor to each processor in a communicator but instead is replicated on several intermediate nodes which then replicated the message to nodes in lower leafs. Hence, the intermediate compute nodes become "virtual root compute nodes" for the purpose of replicating the broadcast message to lower levels of a tree.

  7. Radiative ballistic phonon transport in silicon-nitride membranes at low temperatures

    NARCIS (Netherlands)

    Hoevers, H.F.C.; Ridder, M.L.; Germeau, A.; Bruijn, M.P.; de Korte, P.A.J.; Wiegerink, Remco J.

    2005-01-01

    We studied the phonon transport in free-standing 1 µm thick silicon-nitride membranes at temperatures around 100 mK. By varying the geometry of the membranes and the dimensions of the heater element, we are able to distinguish between radiative and diffuse phonon transport. The data indicate that

  8. Temperature-dependent gas transport and its correlation with kinetic ...

    Indian Academy of Sciences (India)

    2017-05-20

    May 20, 2017 ... have been made to see this trade-off relation at relatively higher temperature. ... drug delivery, etc. Membrane-based separation process on polymer nanocomposite has been extensively discussed in lit- erature. The extraordinary properties of ... in solubility, with increased permeability due to interac-.

  9. Synthesis, structure and low temperature study of electric transport ...

    Indian Academy of Sciences (India)

    1. Introduction. Layered perovskite oxides are a promising group of mixed- conducting materials with potential applications for oxygen- separation membranes, gas sensor devices and electrodes of intermediate-temperature solid oxide fuel cells (Moseley and. Williams 1989; Meixner and Lampe 1996; Skinner and Kil-.

  10. Magnetometry and electrical transport measurements of high temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Mun Keat [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-13

    Prior to preparing and performing measurements in pulsed magnetic fields, it is necessary to characterize them. For the cuprates such as HgBa2CuO4+δ (Hg1201), measurements of the superconducting temperature is essential. This experiment comprises just such a characterization of Hg1201 crystals to be used for pulsed magnetic field measurements.

  11. Influence of Temperature on the Transport Behaviour of Aromatic ...

    African Journals Online (AJOL)

    In this paper, the methodology and results obtained by use of gravimetric method to study the sorption of benzene and toluene in calcite-filled low density polyethylene composite samples at two temperature regimes, 40oC and 65oC were presented. The composite was prepared by compounding low density polyethylene ...

  12. Allowable temperature rise in tubes of the piles: Precautions against boiling

    Energy Technology Data Exchange (ETDEWEB)

    Woods, W.K.

    1945-09-27

    In the design of the pile, it was considered advisable never to impose so great a heat load on any tube that the available header pressure would be insufficient to sweep the tube free of vapor if boiling should accidentally be initiated in the tube. Figures are given for the maximum temperature rises permissible, as function of header pressure and orifice diameter.

  13. Integrated heat transport simulation of high ion temperature plasma of LHD

    International Nuclear Information System (INIS)

    Murakami, S.; Yamaguchi, H.; Sakai, A.

    2014-10-01

    A first dynamical simulation of high ion temperature plasma with carbon pellet injection of LHD is performed by the integrated simulation GNET-TD + TASK3D. NBI heating deposition of time evolving plasma is evaluated by the 5D drift kinetic equation solver, GNET-TD and the heat transport of multi-ion species plasma (e, H, He, C) is studied by the integrated transport simulation code, TASK3D. Achievement of high ion temperature plasma is attributed to the 1) increase of heating power per ion due to the temporal increase of effective charge, 2) reduction of effective neoclassical transport with impurities, 3) reduction of turbulence transport. The reduction of turbulence transport is most significant contribution to achieve the high ion temperature and the reduction of the turbulent transport from the L-mode plasma (normal hydrogen plasma) is evaluated to be a factor about five by using integrated heat transport simulation code. Applying the Z effective dependent turbulent reduction model we obtain a similar time behavior of ion temperature after the C pellet injection with the experimental results. (author)

  14. Temperature-Dependent Charge Transport through Individually Contacted DNA Origami-Based Au Nanowires.

    Science.gov (United States)

    Teschome, Bezu; Facsko, Stefan; Schönherr, Tommy; Kerbusch, Jochen; Keller, Adrian; Erbe, Artur

    2016-10-11

    DNA origami nanostructures have been used extensively as scaffolds for numerous applications such as for organizing both organic and inorganic nanomaterials, studying single molecule reactions, and fabricating photonic devices. Yet, little has been done toward the integration of DNA origami nanostructures into nanoelectronic devices. Among other challenges, the technical difficulties in producing well-defined electrical contacts between macroscopic electrodes and individual DNA origami-based nanodevices represent a serious bottleneck that hinders the thorough characterization of such devices. Therefore, in this work, we have developed a method to electrically contact individual DNA origami-based metallic nanowires using electron beam lithography. We then characterize the charge transport of such nanowires in the temperature range from room temperature down to 4.2 K. The room temperature charge transport measurements exhibit ohmic behavior, whereas at lower temperatures, multiple charge transport mechanisms such as tunneling and thermally assisted transport start to dominate. Our results confirm that charge transport along metallized DNA origami nanostructures may deviate from pure metallic behavior due to several factors including partial metallization, seed inhomogeneities, impurities, and weak electronic coupling among AuNPs. Besides, this study further elucidates the importance of variable temperature measurements for determining the dominant charge transport mechanisms for conductive nanostructures made by self-assembly approaches.

  15. Comparisons of theoretically predicted transport from ion temperature gradient instabilities to L-mode tokamak experiments

    International Nuclear Information System (INIS)

    Kotschenreuther, M.; Wong, H.V.; Lyster, P.L.; Berk, H.L.; Denton, R.; Miner, W.H.; Valanju, P.

    1991-12-01

    The theoretical transport from kinetic micro-instabilities driven by ion temperature gradients is a sheared slab is compared to experimentally inferred transport in L-mode tokamaks. Low noise gyrokinetic simulation techniques are used to obtain the ion thermal transport coefficient X. This X is much smaller than in experiments, and so cannot explain L-mode confinement. Previous predictions based on fluid models gave much greater X than experiments. Linear and nonlinear comparisons with the fluid model show that it greatly overestimates transport for experimental parameters. In addition, disagreements among previous analytic and simulation calculations of X in the fluid model are reconciled

  16. Air Emission Projections During Acid Cleaning of F-Canyon Waste Header No.2

    International Nuclear Information System (INIS)

    CHOI, ALEXANDER

    2004-01-01

    The purpose of this study was to develop the air emission projections for the maintenance operation to dissolve and flush out the scale material inside the F-Canyon Waste Header No.2. The chemical agent used for the dissolution is a concentrated nitric acid solution, so the pollutant of concern is the nitric acid vapor. Under the very conservative operating scenarios considered in this study, it was determined that the highest possible rate of nitric acid emission during the acid flush would be 0.048 lb. per hr. It turns out that this worst-case air emission projection is just below the current exemption limit of 0.05 lb. per hr. for permit applications

  17. MRC2014: Extensions to the MRC format header for electron cryo-microscopy and tomography.

    Science.gov (United States)

    Cheng, Anchi; Henderson, Richard; Mastronarde, David; Ludtke, Steven J; Schoenmakers, Remco H M; Short, Judith; Marabini, Roberto; Dallakyan, Sargis; Agard, David; Winn, Martyn

    2015-11-01

    The MRC binary file format is widely used in the three-dimensional electron microscopy field for storing image and volume data. Files contain a header which describes the kind of data held, together with other important metadata. In response to advances in electron microscopy techniques, a number of variants to the file format have emerged which contain useful additional data, but which limit interoperability between different software packages. Following extensive discussions, the authors, who represent leading software packages in the field, propose a set of extensions to the MRC format standard designed to accommodate these variants, while restoring interoperability. The MRC format is equivalent to the map format used in the CCP4 suite for macromolecular crystallography, and the proposal also maintains interoperability with crystallography software. This Technical Note describes the proposed extensions, and serves as a reference for the standard. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Smooth Information Flow in Temperature Climate Network Reflects Mass Transport

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav; Jajcay, Nikola; Hartman, David; Paluš, Milan

    2017-01-01

    Roč. 27, č. 3 (2017), č. článku 035811. ISSN 1054-1500 R&D Projects: GA ČR GCP103/11/J068; GA MŠk LH14001 Institutional support: RVO:67985807 Keywords : directed network * causal network * Granger causality * climate network * information flow * temperature network Subject RIV: IN - Informatics, Computer Science OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 2.283, year: 2016

  19. High-frequency filtering for low-temperature thermal transport studies in nanostructures

    OpenAIRE

    Torgovkin, Andrii

    2012-01-01

    Filtering of external unwanted RF-noise and thermal noise generated at the high-temperature parts of the measuring circuit is essential for successful measurements of thermal transport of nanostructures at low temperatures. This is because of thermal decoupling of the systems, i.e. the extreme weakness of thermal conduction at sub-Kelvin temperatures, leading easily to overheating even with excess power in sub pW range. We have started to improve the noise filtering in our cryogenic diluti...

  20. Effect of microclimate temperature during transportation of broiler chickens on quality of the pectoralis major muscle.

    Science.gov (United States)

    Dadgar, S; Lee, E S; Leer, T L V; Burlinguette, N; Classen, H L; Crowe, T G; Shand, P J

    2010-05-01

    This study investigated the effect of microclimate temperature during preslaughter transportation on chicken meat quality. Ninety broilers per load of 2,900 were monitored individually during 3 to 4 h of preslaughter transport in an actively ventilated trailer. Six transport test runs were conducted at average ambient temperatures of -27, -22, -17, -5, +4, and +11 degrees C. Birds were classified into 4 groups based upon the temperatures recorded in their immediate surroundings as follows: -16 to 0, 0 to 10, 10 to 20, and 20 to 30 degrees C. Internal body temperatures of the birds were recorded using Thermocron DS1922L iButtons. Birds were slaughtered in a commercial facility and meat quality of the chilled carcasses was evaluated by determination of pH, color, drip loss, thaw loss, cook loss, shear force, water-binding capacity, and pellet cook yield of the pectoralis major muscle. The breast meat from birds exposed to temperatures below 0 degrees C showed a significantly higher (P < 0.05) ultimate pH. Breast meat from birds exposed to temperatures below 0 degrees C showed significantly higher (P < 0.05) ultimate pH, a* value, water-binding capacity, and pellet cook yield and a significantly lower L* compared with breast meat of birds exposed to temperatures above 0 degrees C. The average core body temperatures were significantly lower (P < 0.05) during transport for birds exposed to temperatures below 0 degrees C compared with those exposed to temperatures between 0 and 10 degrees C. The latter birds had significantly lower (P < 0.05) core body temperatures compared with those exposed to temperatures above 10 degrees C. Thaw loss was significantly higher (P < 0.05) for breast meat of birds exposed to temperatures above 20 degrees C during transportation. There was no significant trend for b* value, drip loss, cook loss, or shear values based on environment temperature immediately surrounding the birds. Exposure to temperatures below 0 degrees C increased the

  1. Effects of temperature on graphene oxide deposition and transport in saturated porous media.

    Science.gov (United States)

    Wang, Mei; Gao, Bin; Tang, Deshan; Sun, Huimin; Yin, Xianqiang; Yu, Congrong

    2017-06-05

    Laboratory batch sorption and sand column experiments were conducted to examine the effects of temperature (6 and 24°C) on the retention and transport of GO in water-saturated porous media with different combination of solution ionic strength (IS, 1 and 10mM), sand type (natural and acid-cleaned), and grain size (coarse and fine). Although results from batch sorption experiment showed that temperature affected the sorption of GO onto the sand grains at the low IS, the interactions between GO and the sand were relatively weak, which did make the temperature effect prominent. When the IS was 1mM, experimental temperature showed little effect on GO retention and transport regardless of the medium properties. GO was highly mobile in the sand columns with mass recovery rates ranged from 77.3% to 92.4%. When the IS increased to 10mM, temperature showed notable effects on GO retention and transport in saturated porous media. For all the combinations of sand type and grain size, the higher the temperature was, the less mobile GO particles were. The effects of temperature on GO retention and transport in saturated porous media were further verified though simulations from an advection-dispersion-reaction model. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Fabrication of an improved tube-to-pipe header heat exchanger for the Fuel Failure Mockup (FFM) Facility

    International Nuclear Information System (INIS)

    Prislinger, J.J.; Jones, R.H.

    1977-05-01

    The procedure used in fabricating an improved tube-to-pipe header heat exchanger for the Fuel Failure Mockup (FFM) Facility is described. Superior performance is accomplished at reduced cost with adherence to the ASME Boiler and Pressure Vessel Code. The techniques used and the method of fabrication are described in detail

  3. Advanced High-Temperature, High-Pressure Transport Reactor Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Swanson

    2005-08-30

    The transport reactor development unit (TRDU) was modified to accommodate oxygen-blown operation in support of a Vision 21-type energy plex that could produce power, chemicals, and fuel. These modifications consisted of changing the loop seal design from a J-leg to an L-valve configuration, thereby increasing the mixing zone length and residence time. In addition, the standpipe, dipleg, and L-valve diameters were increased to reduce slugging caused by bubble formation in the lightly fluidized sections of the solid return legs. A seal pot was added to the bottom of the dipleg so that the level of solids in the standpipe could be operated independently of the dipleg return leg. A separate coal feed nozzle was added that could inject the coal upward into the outlet of the mixing zone, thereby precluding any chance of the fresh coal feed back-mixing into the oxidizing zone of the mixing zone; however, difficulties with this coal feed configuration led to a switch back to the original downward configuration. Instrumentation to measure and control the flow of oxygen and steam to the burner and mix zone ports was added to allow the TRDU to be operated under full oxygen-blown conditions. In total, ten test campaigns have been conducted under enriched-air or full oxygen-blown conditions. During these tests, 1515 hours of coal feed with 660 hours of air-blown gasification and 720 hours of enriched-air or oxygen-blown coal gasification were completed under this particular contract. During these tests, approximately 366 hours of operation with Wyodak, 123 hours with Navajo sub-bituminous coal, 143 hours with Illinois No. 6, 106 hours with SUFCo, 110 hours with Prater Creek, 48 hours with Calumet, and 134 hours with a Pittsburgh No. 8 bituminous coal were completed. In addition, 331 hours of operation on low-rank coals such as North Dakota lignite, Australian brown coal, and a 90:10 wt% mixture of lignite and wood waste were completed. Also included in these test campaigns was

  4. Temperatures on Io: Implications to Geophysics, Volcanology, and Volatile Transport

    Science.gov (United States)

    McEwen, A. S.; Isbell, N. R.; Edwards, K. E.; Pearl, J. C.

    1996-03-01

    Voyager 1 IRIS spectra of Io from 4- to 55 micrometers wavelength have been further analyzed. We report two advances here: improved pointing corrections for the IRIS observations and improved background thermal models. The pointing corrections allow detailed mapping of thermal anomalies relative to surface features, thus enabling improved geologic interpretations. The identification of low-temperature (T) thermal anomalies due to cooling flows and pyroclastics, and to determination of Io's heat flow. The background Ts also provide important constraints on models of Io's atmosphere and volatile transfers. A new model for Io's surface that has emerged from this and other studies includes 3 basic thermophysical units: (1) bright, SO2-rich regolith with a high thermal inertia over ~80% of the surface; (2) darker, SO2-poor regolith with a low thermal inertia over ~18% of Io; and (3) high-T hot spots over ~2% of the surface. We present new evidence that unit 2 contains ubiquitous low-T geothermal anomalies from cooling volcanic deposits.

  5. Transport studies in FTU with decoupled temperature and current density profiles

    International Nuclear Information System (INIS)

    Bracco, G.; Buratti, P.; Micozzi, P.; Tudisco, O.

    1994-01-01

    Electron temperature profiles in tokamaks are subject to global constraints that can be attributed either to their link with current profiles, i.e. to MHD stability conditions, a clear example being sawtooth activity, or to other mechanisms like marginal stability. Also a direct effect on transport coefficients was attributed to the current profile. Fast current ramps in FTU ohmic pulses have been used to study the effect of current profile variations on the energy confinement time. The global profile constraint was transiently removed in these pulses, and variations in the shape of temperature profiles could be observed. Modified profiles were also observed in pulses with a strong central radiative sink; in this case the modification was not transient. Finally, the transport properties in the central region have been studied by the analysis of temperature evolution between crashes of very long period sawteeth; very small electron heat transport was found. (author) 6 refs., 5 figs

  6. Integrated electronic transport and thermometry at milliKelvin temperatures and in strong magnetic fields.

    Science.gov (United States)

    Samkharadze, N; Kumar, A; Manfra, M J; Pfeiffer, L N; West, K W; Csáthy, G A

    2011-05-01

    We fabricated a He-3 immersion cell for transport measurements of semiconductor nanostructures at ultra low temperatures and in strong magnetic fields. We have a new scheme of field-independent thermometry based on quartz tuning fork Helium-3 viscometry which monitors the local temperature of the sample's environment in real time. The operation and measurement circuitry of the quartz viscometer is described in detail. We provide evidence that the temperature of two-dimensional electron gas confined to a GaAs quantum well follows the temperature of the quartz viscometer down to 4 mK.

  7. A Review of the Thermodynamic, Transport, and Chemical Reaction Rate Properties of High-temperature Air

    Science.gov (United States)

    Hansen, C Frederick; Heims, Steve P

    1958-01-01

    Thermodynamic and transport properties of high temperature air, and the reaction rates for the important chemical processes which occur in air, are reviewed. Semiempirical, analytic expressions are presented for thermodynamic and transport properties of air. Examples are given illustrating the use of these properties to evaluate (1) equilibrium conditions following shock waves, (2) stagnation region heat flux to a blunt high-speed body, and (3) some chemical relaxation lengths in stagnation region flow.

  8. Low-temperature ballistic transport in nanoscale epitaxial graphene cross junctions

    OpenAIRE

    Weingart, S.; Bock, C.; Kunze, U.; Speck, F.; Seyller, Th.; Ley, L.

    2009-01-01

    We report on the observation of inertial-ballistic transport in nanoscale cross junctions fabricated from epitaxial graphene grown on SiC(0001). Ballistic transport is indicated by a negative bend resistance of R12,43 ~ 170 ohm which is measured in a non-local, four-terminal configuration at 4.2 K and which vanishes as the temperature is increased above 80 K.

  9. Temperature-dependent charge transport mechanisms in carbon sphere/polyaniline composite

    Science.gov (United States)

    Nieves, Cesar A.; Martinez, Luis M.; Meléndez, Anamaris; Ortiz, Margarita; Ramos, Idalia; Pinto, Nicholas J.; Zimbovskaya, Natalya

    2017-12-01

    Charge transport in the temperature range 80 K polyaniline (PANi). PANi was synthesized via the oxidative polymerization of aniline with ammonium peroxydisulfate (APS) in acidic media. The CS/PANi composite was prepared by coating the spheres with a thin polyaniline (PANi) film doped with hydrochloric acid (HCl) in situ during the polymerization process. Temperature dependent conductivity measurements show that three dimensional variable range hopping of electrons between polymeric chains in PANi-filled gaps between CS is the predominant transport mechanism through CS/PANi composites. The high conductivity of the CS/PANi composite makes the material attractive for the fabrication of devices and sensors.

  10. Effects of temperature anisotropy on neoclassical transport in the plateau and banana-plateau regimes

    International Nuclear Information System (INIS)

    Taguchi, Masayoshi

    1999-01-01

    The neoclassical transport theory in a presence of temperature anisotropy is investigated in the low to the intermediate collision frequency regimes for a large aspect-ratio tokamak plasma. The standard procedure for an isotropic plasma in the plateau regime is extended to an anisotropic plasma, and the neoclassical transport coefficients in this regime are explicitly calculated. By interpolating the results in the plateau regime and the previously obtained ones in the banana regime, the expressions for the neoclassical transport coefficients which are continuously valid from the banana to the plateau regimes are presented. (author)

  11. Effects of Temperature on Electron Transport in Arum maculatum Mitochondria 1

    Science.gov (United States)

    Cook, Neil D.; Cammack, Richard

    1985-01-01

    The effects of temperature upon the respiratory pathways of Arum maculatum mitochondria have been studied. The alternate oxidase sustained a greater proportion of the total respiration at low temperatures than at higher temperatures. Arrhenius plots of respiratory activities show two discontinuities, one at 14°C and one at 21°C. The lower temperature discontinuity was associated with electron transport from succinate dehydrogenase to the alternative oxidase, enzymes that face the inner side of the membrane while the higher temperature discontinuity was associated with electron transport from the external NADH dehydrogenase to cytochrome c oxidase, which face the outer side of the membrane. Both discontinuities resulted in a decrease in the activation energy for electron transport on one side of the membrane. Arrhenius plots of transmembrane electron transport showed discontinuities at both 14° and 21°C but the upper discontinuity resulted in an increase in the activation energy. Activation energies determined for the respiratory activities show that above 21°C the exogenous NADH-cytochrome pathway and the succinate-alternative oxidase pathway were lower than those for the NADH-alternative pathway or the succinate cytochrome pathway. PMID:16664411

  12. Low-temperature electrical transport in B-doped ultrananocrystalline diamond film

    International Nuclear Information System (INIS)

    Li, Lin; Zhao, Jing; Hu, Zhaosheng; Quan, Baogang; Li, Junjie; Gu, Changzhi

    2014-01-01

    B-doped ultrananocrystalline diamond (UNCD) films are grown using hot-filament chemical vapor deposition method, and their electrical transport properties varying with temperature are investigated. When the B-doped concentration of UNCD film is low, a step-like increase feature of the resistance is observed with decreasing temperature, reflecting at least three temperature-modified electronic state densities at the Fermi level according to three-dimensional Mott's variable range hopping transport mechanism, which is very different from that of reported B-doped nanodiamond. With increasing B-doped concentration, a superconductive transformation occurs in the UNCD film and the highest transformation temperature of 5.3 K is observed, which is higher than that reported for superconducting nanodiamond films. In addition, the superconducting coherence length is about 0.63 nm, which breaks a reported theoretical and experimental prediction about ultra-nanoscale diamond's superconductivity

  13. Temperature-dependent transport properties of graphene decorated by alkali metal adatoms (Li, K)

    Science.gov (United States)

    Woo, S.; Hemmatiyan, S.; Morrison, T. D.; Rathnayaka, K. D. D.; Lyuksyutov, I. F.; Naugle, D. G.

    2017-12-01

    We report the electrical transport properties of graphene for dilute alkali metal decoration (n ˜ 2 × 1012 cm-2) at cryogenic temperatures. Upon deposition of K and Li atoms at T = 20 K, graphene devices are doped with electrons, and the charge carrier mobility is decreased. As temperature is increased, the number of electrons donated to the graphene and the number of charged scatterers are reduced, and the mobility of the metal decorated graphene is increased. This differs from the typical temperature-dependent transport in undecorated graphene, where the mobility decreases with increasing temperature. To investigate the kinetic behavior of adatoms on graphene, we estimate the hopping time of the Li and K adatoms on graphene based on the migration barrier in the low concentration regime of the metal adatoms by Density Functional Theory calculations. The calculations reveal that these adatoms are mobile even at cryogenic temperatures and become more mobile with increasing temperature, allowing for cluster formation of adatoms. This indicates that the dominant factor in the electron transport on warming is a cluster formation.

  14. Evaluation of intergranular cracks on the ring header cross at Grand Gulf Unit No. 1

    International Nuclear Information System (INIS)

    Czajkowski, C.J.

    1987-01-01

    A metallurgical investigation was performed on a sample of cracked ring header cross material from the Grand Gulf Unit No. 1 Nuclear Power Station. The cracks were located in a 6-7 in (15-17.5 cm) width band running circumferentially below the cross to cap weld with a similar band above the cross to discharger pipe weld. The indications were up to 19 mm in length and 6.0 mm in depth. This particular sample was cut from a cross which had not seen actual service but which had been used to qualify the induction heating stress improvement (IHSI) technique for the Grand Gulf units. The base material was SA 182 material manufactured to SA 403-type WP 304 stainless steel. The investigation consisted of visual/dye penetrant examination, chemical analysis, hardness testing, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The evaluated cracks were intergranular and initiated on the forging's exterior surface. The grain size of the material was larger than ASTM 00 and no definitive corrosive species were found by Energy Dispersive Spectroscopy (EDS). The cracking is considered to be the result of the forging having been overheated/burned during manufacture. (author)

  15. Development of high temperature molten salt transport technology for pyrometallurgical reprocessing

    International Nuclear Information System (INIS)

    Hijikata, Takatoshi; Koyama, Tadafumi

    2009-01-01

    Pyrometallurgical reprocessing technology is currently being focused in many countries for closing actinide fuel cycle because of its favorable economic potential and an intrinsic proliferation-resistant feature due to the inherent difficulty of extracting weapons-usable plutonium. The feasibility of pyrometallurgical reprocessing has been demonstrated through many laboratory scale experiments. Hence the development of the engineering technology necessary for pyrometallurgical reprocessing is a key issue for industrial realization. The development of high-temperature transport technologies for molten salt and liquid cadmium is crucial for pyrometallurgical processing; however, there have been very few transport studies on high-temperature fluids. In this study, a salt transport test rig was installed in an argon glove box with the aim of developing technologies for transporting molten salt at approximately 773 K. The gravitation transport of the molten salt at approximately 773 K could be well controlled at a velocity from 0.1 to 1.2 m/s by adjusting the valve. Consequently, the flow in the molten salt can be controlled from laminar flow to turbulent flow. It was demonstrated that; using a centrifugal pump, molten salt at approximately 773 K could be transported at a controlled rate from 2.5 to 8 dm 3 /min against a 1 m head. (author)

  16. Experimental study of electron temperature gradient influence on impurity turbulent transport in fusion plasmas

    International Nuclear Information System (INIS)

    Villegas, D.

    2010-01-01

    Understanding impurity transport is a key to an optimal regime for a future fusion device. In this thesis, the theoretical and experimental influence of the electron temperature gradient R/L Te on heavy impurity transport is analyzed both in Tore Supra and ASDEX Upgrade. The electron temperature profile is modified locally by heating the plasma with little ECRH power deposited at two different radii. Experimental results have been obtained with the impurity transport code (ITC) which has been completed with a genetic algorithm allowing to determine the transport coefficient profiles with more accuracy. Transport coefficient profiles obtained by a quasilinear gyrokinetic code named QuaLiKiz are consistent with the experimental ones despite experimental uncertainties on gradients. In the core dominated by electron modes, the lower R/L Te the lower the nickel diffusion coefficient. The latter tends linearly to the neoclassical level when the instability threshold is approached. The experimental threshold is in agreement with the one computed by QuaLiKiz. Further out, where the plasma is dominated by ITG, which are independent of R/L Te , both experimental and simulated results show no modification in the diffusion coefficient profile. Furthermore, the convection velocity profile is not modified. This is attributed to a very small contribution of the thermodiffusion (1/Z dependence) in the total convection. On ASDEX, the preliminary results, very different from the Tore Supra ones, show a internal transport barrier for impurities located at the same radius as the strong ECRH power deposit. (author) [fr

  17. Temperature dependent transport of two dimensional electrons in the integral quantum Hall regime

    International Nuclear Information System (INIS)

    Wi, H.P.

    1986-01-01

    This thesis is concerned with the temperature dependent electronic transport properties of a two dimensional electron gas subject to background potential fluctuations and a perpendicular magnetic field. The author carried out an extensive temperature dependent study of the transport coefficients, in the region of an integral quantum plateau, in an In/sub x/Ga/sub 1-x/As/InP heterostructure for 4.2K 10 cm -2 meV -1 ) even at the middle between two Landau levels, which is unexpected from model calculations based on short ranged randomness. In addition, the different T dependent behavior of rho/sub xx/ between the states in the tails and those near the center of a Landau level, indicates the existence of different electron states in a Landau level. Additionally, the author reports T-dependent transport measurements in the transition region between two quantum plateaus in several different materials

  18. Analog performance of vertical nanowire TFETs as a function of temperature and transport mechanism

    Science.gov (United States)

    Martino, Marcio Dalla Valle; Neves, Felipe; Ghedini Der Agopian, Paula; Martino, João Antonio; Vandooren, Anne; Rooyackers, Rita; Simoen, Eddy; Thean, Aaron; Claeys, Cor

    2015-10-01

    The goal of this work is to study the analog performance of tunnel field effect transistors (TFETs) and its susceptibility to temperature variation and to different dominant transport mechanisms. The experimental input characteristic of nanowire TFETs with different source compositions (100% Si and Si1-xGex) has been presented, leading to the extraction of the Activation Energy for each bias condition. These first results have been connected to the prevailing transport mechanism for each configuration, namely band-to-band tunneling (BTBT) or trap assisted tunneling (TAT). Afterward, this work analyzes the analog behavior, with the intrinsic voltage gain calculated in terms of Early voltage, transistor efficiency, transconductance and output conductance. Comparing the results for devices with different source compositions, it is interesting to note how the analog trends vary depending on the source characteristics and the prevailing transport mechanisms. This behavior results in a different suitability analysis depending on the working temperature. In other words, devices with full-Silicon source and non-abrupt junction profile present the worst intrinsic voltage gain at room temperature, but the best results for high temperatures. This was possible since, among the 4 studied devices, this configuration was the only one with a positive intrinsic voltage gain dependence on the temperature variation.

  19. Two-Dimensional Spatial Imaging of Charge Transport in Germanium Crystals at Cryogenic Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Moffatt, Robert [Stanford Univ., CA (United States)

    2016-03-01

    In this dissertation, I describe a novel apparatus for studying the transport of charge in semiconductors at cryogenic temperatures. The motivation to conduct this experiment originated from an asymmetry observed between the behavior of electrons and holes in the germanium detector crystals used by the Cryogenic Dark Matter Search (CDMS). This asymmetry is a consequence of the anisotropic propagation of electrons in germanium at cryogenic temperatures. To better model our detectors, we incorporated this effect into our Monte Carlo simulations of charge transport. The purpose of the experiment described in this dissertation is to test those models in detail. Our measurements have allowed us to discover a shortcoming in our most recent Monte Carlo simulations of electrons in germanium. This discovery would not have been possible without the measurement of the full, two-dimensional charge distribution, which our experimental apparatus has allowed for the first time at cryogenic temperatures.

  20. Thermal-hydraulic analysis of Ignalina NPP compartments response to group distribution header rupture using RALOC4 code

    International Nuclear Information System (INIS)

    Urbonavicius, E.

    2000-01-01

    The Accident Localisation System (ALS) of Ignalina NPP is a containment of pressure suppression type designed to protect the environment from the dangerous impact of the radioactivity. The failure of ALS could lead to contamination of the environment and prescribed public radiation doses could be exceeded. The purpose of the presented analysis is to perform long term thermal-hydraulic analysis of compartments response to Group Distribution Header rupture and verify if design pressure values are not exceeded. (authors)

  1. Transport properties of glass-forming liquids suggest that dynamic crossover temperature is as important as the glass transition temperature.

    Science.gov (United States)

    Mallamace, Francesco; Branca, Caterina; Corsaro, Carmelo; Leone, Nancy; Spooren, Jeroen; Chen, Sow-Hsin; Stanley, H Eugene

    2010-12-28

    It is becoming common practice to partition glass-forming liquids into two classes based on the dependence of the shear viscosity η on temperature T. In an Arrhenius plot, ln η vs 1/T, a strong liquid shows linear behavior whereas a fragile liquid exhibits an upward curvature [super-Arrhenius (SA) behavior], a situation customarily described by using the Vogel-Fulcher-Tammann law. Here we analyze existing data of the transport coefficients of 84 glass-forming liquids. We show the data are consistent, on decreasing temperature, with the onset of a well-defined dynamical crossover η(×), where η(×) has the same value, η(×) ≈ 10(3) Poise, for all 84 liquids. The crossover temperature, T(×), located well above the calorimetric glass transition temperature T(g), marks significant variations in the system thermodynamics, evidenced by the change of the SA-like T dependence above T(×) to Arrhenius behavior below T(×). We also show that below T(×) the familiar Stokes-Einstein relation D/T ∼ η(-1) breaks down and is replaced by a fractional form D/T ∼ η(-ζ), with ζ ≈ 0.85.

  2. Spin Transport in Nondegenerate Si with a Spin MOSFET Structure at Room Temperature

    Science.gov (United States)

    Sasaki, Tomoyuki; Ando, Yuichiro; Kameno, Makoto; Tahara, Takayuki; Koike, Hayato; Oikawa, Tohru; Suzuki, Toshio; Shiraishi, Masashi

    2014-09-01

    Spin transport in nondegenerate semiconductors is expected to pave the way to the creation of spin transistors, spin logic devices, and reconfigurable logic circuits, because room-temperature (RT) spin transport in Si has already been achieved. However, RT spin transport has been limited to degenerate Si, which makes it difficult to produce spin-based signals because a gate electric field cannot be used to manipulate such signals. Here, we report the experimental demonstration of spin transport in nondegenerate Si with a spin metal-oxide-semiconductor field-effect transistor (MOSFET) structure. We successfully observe the modulation of the Hanle-type spin-precession signals, which is a characteristic spin dynamics in nondegenerate semiconductors. We obtain long spin transport of more than 20 μm and spin rotation greater than 4π at RT. We also observe gate-induced modulation of spin-transport signals at RT. The modulation of the spin diffusion length as a function of a gate voltage is successfully observed, which we attribute to the Elliott-Yafet spin relaxation mechanism. These achievements are expected to lead to the creation of practical Si-based spin MOSFETs.

  3. Temperature dependent dielectric properties and ion transportation in solid polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Sengwa, R. J.; Dhatarwal, Priyanka; Choudhary, Shobhna

    2016-05-01

    Solid polymer electrolyte (SPE) film consisted of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blend matrix with lithium tetrafluroborate (LiBF4) as dopant ionic salt and poly(ethylene glycol) (PEG) as plasticizer has been prepared by solution casting method followed by melt pressing. Dielectric properties and ionic conductivity of the SPE film at different temperatures have been determined by dielectric relaxation spectroscopy. It has been observed that the dc ionic conductivity of the SPE film increases with increase of temperature and also the decrease of relaxation time. The temperature dependent relaxation time and ionic conductivity values of the electrolyte are governed by the Arrhenius relation. Correlation observed between dc conductivity and relaxation time confirms that ion transportation occurs with polymer chain segmental dynamics through hopping mechanism. The room temperature ionic conductivity is found to be 4 × 10-6 S cm-1 which suggests the suitability of the SPE film for rechargeable lithium batteries.

  4. Modelling of Temperature Profiles and Transport Scaling in Auxiliary Heated Tokamaks

    DEFF Research Database (Denmark)

    Callen, J.D.; Christiansen, J.P.; Cordey, J.G.

    1987-01-01

    in detail: (i) a heat pinch or excess temperature gradient model with constant coefficients; and (ii) a non-linear heat diffusion coefficient (χ) model. Both models predict weak (lesssim20%) temperature profile responses to physically relevant changes in the heat deposition profile – primarily because...... that result from the models clarify why temperature profiles in many tokamaks are often characterized as exhibiting a high degree of 'profile consistency'. Global transport scaling laws are also derived from the two models. The non-linear model with χ ∝ dT/dr produces a non-linear energy confinement time (L......-mode) scaling with input power, . The constant heat pinch or excess temperature gradient model leads to the offset linear law for the total stored energy W with Pin, W = τinc Pin + W(0), which describes JET auxiliary heating data quite well. It also provides definitions for the incremental energy confinement...

  5. Electron transport in mercury vapor: cross sections, pressure and temperature dependence of transport coefficients and NDC effects★

    Science.gov (United States)

    Mirić, Jasmina; Simonović, Ilija; Petrović, Zoran Lj.; White, Ronald D.; Dujko, Saša

    2017-11-01

    In this work we propose a complete and consistent set of cross sections for electron scattering in mercury vapor. The set is validated through a series of comparisons between swarm data calculated using a multi term theory for solving the Boltzmann equation and Monte Carlo simulations, and the available experimental data. Other sets of cross sections for electron scattering in mercury vapor were also used as input in our numerical codes with the aim of testing their completeness, consistency and accuracy. The calculated swarm parameters are compared with measurements in order to assess the quality of the cross sections in providing data for plasma modeling. In particular, we discuss the dependence of transport coefficients on the pressure and temperature of mercury vapor, and the occurrence of negative differential conductivity (NDC) in the limit of lower values of E/N. We have shown that the phenomenon of NDC is induced by the presence of mercury dimers and that can be controlled by varying either pressure or temperature of mercury vapor. The effective inelastic cross section for mercury dimers is estimated for a range of pressures and temperatures. It is shown that the measured and calculated drift velocities agree very well only if the effective inelastic cross section for mercury dimers and thermal motion of mercury atoms are carefully considered and implemented in numerical calculations. Contribution to the Topical Issue "Physics of Ionized Gases (SPIG 2016)", edited by Goran Poparic, Bratislav Obradovic, Dragana Maric and Aleksandar Milosavljevic.

  6. Influence of Magnetic Field on Electric Charge Transport in Holomiun Thin Films at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Jan Dudas

    2005-01-01

    Full Text Available Holmium thin films were prepared by evaporation in ultrahigh vacuum (UHV and high precision electrical resistance measurements were performed on them as well as on holomium bulk sample in the wide temperature range from 4,2 K up to the room temperature. Electric charge transport is profoundly influenced by the magnetic structure at low temperatures and a "knee-like" resistance anomaly was observed near the transportation from paramagnetic state to basal-plane spiral structure in bulk with the Neel temperature TN=128,9 K and below ~ 122 K in thin Ho films in a thickness range from 98 nm to 215 nm. Unexpected resistance minimum at ~ 9 K and a slope´s charge of the R vs. T curve near ~ 170 K was observed in 215 nm thin film. Application of magnetic field parallel to the substrate and thin film plane for temperatures below ~ 150 K caused the decrease of resistence value with increasing magnetic flux density. Increasing suppression of the TN value up to ~ 5 K with increasing flux density value up to 5 T was observed in Ho films. 

  7. Transport through (Ga,Mn)As nanoislands: Coulomb blockade and temperature dependence of the conductance

    Science.gov (United States)

    Schlapps, Markus; Lermer, Teresa; Geissler, Stefan; Neumaier, Daniel; Sadowski, Janusz; Schuh, Dieter; Wegscheider, Werner; Weiss, Dieter

    2009-09-01

    We report on magnetotransport measurements of nanoconstricted (Ga,Mn)As devices showing very large resistance changes that can be controlled by both an electric and a magnetic field. Based on the bias voltage and temperature-dependent measurements down to the millikelvin range we compare the models currently used to describe transport through (Ga,Mn)As nanoconstrictions. We provide an explanation for the observed spin-valvelike behavior during a magnetic field sweep by means of the magnetization configurations in the device. Furthermore, we prove that Coulomb blockade plays a decisive role for the transport mechanism and show that modeling the constriction as a granular metal describes the temperature and bias dependence of the conductance correctly and allows to estimate the number of participating islands located in the constriction.

  8. [Insulation characteristics of transport containers for organ cultured donor corneas under different ambient temperatures].

    Science.gov (United States)

    Schroeter, J; Meltendorf, C

    2009-08-01

    The aim of this study was to evaluate the ability of different transport containers to maintain an inside temperature between +10 and +40 degrees C, which is supposed to be safe for organ cultured donor corneas in dextran containing culture media, for a period of 24 hours at ambient temperatures of -10, 0, +10 and +50 degrees C. 3 containers were tested: 1. Styrofoam box with 2.5 cm thick walls (Graft-tec, AL.CHI.MI.A., Padova, Italy). 2. Thermos jug 0.5 litre (Primus, Solna, Sweden), a double walled metal jug. 3. ThempShell-22 degrees (VWR International, Darmstadt, Germany), a box of gel filled plastic elements. The containers were exposed to -10, 0, +10 and +50 degrees C for 24 hours each. A continuous temperature recording of the ambient and internal environments was performed using electronic thermometers (Mini Intelligent Logger, Escort). The inside temperature of the styrofoam box reached the outside temperature level after 80 - 230 min for all tested settings. The Thermos jug reached the outside temperature approximately after 5 hours. In contrast, the inside temperature of the TempShell-22 degrees CC was at -10 degrees C outside temperature 21 degrees C after 6 hours, 19 degrees C after 12 hours and 12 degrees C after 24 hours. At an ambient temperature of 0 and +10 degrees C the inside temperature of the TempShell-22 degrees C was 19.2 and 17.8 degrees C respectively after 24 hours. An ambient temperature of + 50 degrees C led to an inside temperature of the TempShell-22 degrees C of 30.5 degrees C after 6, 38.3 degrees C after 12 hours and 47.0 degrees C after 24 hours. A standard Styrofoam box with 2.5 cm thick walls and the tested thermos jug are not suitable to assure a safe temperature range. The TempShell-22 degrees C assures a safe temperature range for low ambient temperatures (-10 to +10 degrees C) for at least 24 hours and for an ambient temperature of +50 degrees C for at least 10 hours. Georg Thieme Verlag KG Stuttgart.New York.

  9. Analysis of flow fields, temperatures and ruthenium transport in the test facility

    International Nuclear Information System (INIS)

    Kaerkelae, T.; Pyykoenen, J.; Auvinen, A.; Jokiniemi, J.

    2008-03-01

    Ruthenium transport experiments were conducted at VTT during years 2002- 2006. Experiments gave information about ruthenium behaviour in air ingress accident conditions. This study complements those experiments with an analysis of the flows and thermal fields in the test system. Temperature profiles were measured at the walls of the experimental facility. Computational fluid dynamics (CFD) simulations used the measured profiles and provided predictions of flows and temperatures inside the furnace. Ruthenium transport was also modelled with CFD. Thermal characterisation of the reactor demonstrated that buoyancy has a significant role during the cooling after the furnace. A hypothesis of the dominant role of RuO2 and RuO3 condensation on reactor walls gave simulation results that are in accordance with radiotracer measurements of deposition in experiments conducted with furnace at 1500K. Actually, RuO3 does not condensate, but it thermal decomposes to RuO2. This does not seem to have effect on result. Particle formation around the furnace exit could be detected from the comparison of modelling results with the measured profiles. In several other experiments ruthenium behaviour is dominated by other issues. These are related to the complex ruthenium chemistry that includes various surface reactions. Thermal equilibrium indicates significant gaseous RuO4 concentration around 1300 K. It seems that seed particles decreased the catalytic decomposition activity of RuO4 to RuO2 around this temperature pushing the gas concentration towards the equilibrium, and further give rise to gaseous RuO4 transport to low temperatures. At higher temperature increasing mass flow rate of RuO2 particles is likely to catalyse (decomposition) reaction of RuO4 to RuO2. (au)

  10. Electron Temperature Fluctuation Measurements and Transport Model Validation at Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    White, Anne [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-06-22

    for studying core turbulence are needed in order to assess the accuracy of gyrokinetic models for turbulent-driven particle, heat and momentum transport. New core turbulence diagnostics at the world-class tokamaks Alcator C-Mod at MIT and ASDEX Upgrade at the Max Planck Institute for Plasma Physics have been designed, developed, and operated over the course of this project. These new instruments are capable of measuring electron temperature fluctuations and the phase angle between density and temperature fluctuations locally and quantitatively. These new data sets from Alcator C-Mod and ASDEX Upgrade are being used to fill key gaps in our understanding of turbulent transport in tokamaks. In particular, this project has results in new results on the topics of the Transport Shortfall, the role of ETG turbulence in tokamak plasmas, profile stiffness, the LOC/SOC transition, and intrinsic rotation reversals. These data are used in a rigorous process of “Transport model validation”, and this group is a world-leader on using turbulence models to design new hardware and new experiments at tokamaks. A correlation electron cyclotron emission (CECE) diagnostic is an instrument used to measure micro-scale fluctuations (mm-scale, compared to the machine size of meters) of electron temperature in magnetically confined fusion plasmas, such as those in tokamaks and stellarators. These micro-scale fluctuations are associated with drift-wave type turbulence, which leads to enhanced cooling and mixing of particles in fusion plasmas and limits achieving the required temperatures and densities for self-sustained fusion reactions. A CECE system can also be coupled with a reflectometer system that measured micro-scale density fluctuations, and from these simultaneous measurements, one can extract the phase between the density (n) and temperature (T) fluctuations, creating an nT phase diagnostic. Measurements of the fluctuations and the phase angle between them are extremely useful for

  11. Two-temperature transport coefficients of SF6-N2 plasma

    Science.gov (United States)

    Yang, Fei; Chen, Zhexin; Wu, Yi; Rong, Mingzhe; Guo, Anxiang; Liu, Zirui; Wang, Chunlin

    2015-10-01

    Sulfur hexafluoride (SF6) is widely adopted in electric power industry, especially in high-voltage circuit breakers and gas-insulated switchgear. However, the use of SF6 is limited by its high liquidation temperature and high global warming potential. Recently, research shows SF6-N2 mixture, which shows environmental friendliness and good electrical properties, may be a feasible substitute for pure SF6. This paper is devoted to the calculation of and transport coefficients of SF6-N2 mixture under both LTE (local thermodynamic equilibrium) and non-LTE condition. The two-temperature mass action law was used to determine the composition. The transport coefficients were calculated by classical Chapman-Enskog method simplified by Devoto. The thermophysical properties are presented for electron temperatures of 300-40 000 K, ratios of electron to heavy species temperature of 1-10 and N2 mole fraction of 0%-100% at atmospheric pressure. The ionization processes under both LTE and non-LTE have been discussed. The results show that deviations from local thermodynamic equilibrium significantly affect the properties of SF6-N2 plasma, especially before the plasma is fully ionized. The different influence of N2 on properties for SF6-N2 plasma in and out of LTE has been found. The results will serve as reliable reference data for computational simulation of the behavior of SF6-N2 plasmas.

  12. Two-temperature transport coefficients of SF6–N2 plasma

    International Nuclear Information System (INIS)

    Yang, Fei; Chen, Zhexin; Wu, Yi; Rong, Mingzhe; Wang, Chunlin; Guo, Anxiang; Liu, Zirui

    2015-01-01

    Sulfur hexafluoride (SF 6 ) is widely adopted in electric power industry, especially in high-voltage circuit breakers and gas-insulated switchgear. However, the use of SF 6 is limited by its high liquidation temperature and high global warming potential. Recently, research shows SF 6 –N 2 mixture, which shows environmental friendliness and good electrical properties, may be a feasible substitute for pure SF 6 . This paper is devoted to the calculation of and transport coefficients of SF 6 –N 2 mixture under both LTE (local thermodynamic equilibrium) and non-LTE condition. The two–temperature mass action law was used to determine the composition. The transport coefficients were calculated by classical Chapman–Enskog method simplified by Devoto. The thermophysical properties are presented for electron temperatures of 300–40 000 K, ratios of electron to heavy species temperature of 1–10 and N 2 mole fraction of 0%–100% at atmospheric pressure. The ionization processes under both LTE and non-LTE have been discussed. The results show that deviations from local thermodynamic equilibrium significantly affect the properties of SF 6 –N 2 plasma, especially before the plasma is fully ionized. The different influence of N 2 on properties for SF 6 –N 2 plasma in and out of LTE has been found. The results will serve as reliable reference data for computational simulation of the behavior of SF 6 –N 2 plasmas

  13. Transport coefficients in high-temperature ionized air flows with electronic excitation

    Science.gov (United States)

    Istomin, V. A.; Oblapenko, G. P.

    2018-01-01

    Transport coefficients are studied in high-temperature ionized air mixtures using the modified Chapman-Enskog method. The 11-component mixture N2/N2+/N /N+/O2/O2+/O /O+/N O /N O+/e- , taking into account the rotational and vibrational degrees of freedom of molecules and electronic degrees of freedom of both atomic and molecular species, is considered. Using the PAINeT software package, developed by the authors of the paper, in wide temperature range calculations of the thermal conductivity, thermal diffusion, diffusion, and shear viscosity coefficients for an equilibrium ionized air mixture and non-equilibrium flow conditions for mixture compositions, characteristic of those in shock tube experiments and re-entry conditions, are performed. For the equilibrium air case, the computed transport coefficients are compared to those obtained using simplified kinetic theory algorithms. It is shown that neglecting electronic excitation leads to a significant underestimation of the thermal conductivity coefficient at temperatures higher than 25 000 K. For non-equilibrium test cases, it is shown that the thermal diffusion coefficients of neutral species and the self-diffusion coefficients of all species are strongly affected by the mixture composition, while the thermal conductivity coefficient is most strongly influenced by the degree of ionization of the flow. Neglecting electronic excitation causes noticeable underestimation of the thermal conductivity coefficient at temperatures higher than 20 000 K.

  14. Temperature and press load stimulation on thermal transport in fibrous and porous composite insulators

    International Nuclear Information System (INIS)

    Rehman, M.A.; Maqsood, A.

    2006-01-01

    Thermal transport properties of synthetic pliable insulators are measured as a function of applied pressure at constant temperatures. Advantageous Transient Plane Source (ATPS) method is used for the simultaneous measurement of thermal conductivity and thermal diffusivity of these materials and heat capacity per unit volume is then calculated. Three samples namely foam, closed cell foam and fiber glass are subjected to press load, taking into account the flexibility and sustainability of the samples and the requirements of the technique used. The thermal data of the samples were determined within the temperature range (300-414K) and pressure range (Normal -15kPa). These materials are used for thermal insulation and temperature control of air-conditioned space, acoustic and sound insulation, agriculture and fishery, sports and leisure goods, building and civil engineering, industrial packaging cold storage ware house, boiler work and other electric appliances, so they are helpful in reducing energy losses. (author)

  15. Electrical and thermal transport properties of chromium in the neighbourhood of the neel temperature

    International Nuclear Information System (INIS)

    Mustaffa Haji Abdullah

    1989-01-01

    The electrical resistivity, thermal conductivity and Lorentz number of polycrystalline chromium have been measured by the methods of potential probe and longitudinal heat flow respectively in the temperature range of 280 - 360 K. The temperature variation of all transport data show anomalous behaviour in the form of a sharp discontinuity at the Neel temperature T N =311.7 K. The anomaly in the resistivity is well understood as due to the increase in the scattering of conduction electrons by the antiferromagnetic moments. The minimum in the total thermal conductivity is possibly attributed to the critical scattering of phonons by the spin fluctuations in the critical region. The minimum in the Lorentz number is in accordance with those of electrical and thermal conductivities. The values of Lorentz numbers are well above the Sommerfeld value. This is an evidence of a large lattice contribution to the thermal conductivity in chromium. (author)

  16. A floor cover to improve temperature distribution and quality preservation in maritime refrigerated container transport of grapes

    NARCIS (Netherlands)

    Lukasse, Leo; Mensink, Manon; Wissink, Edo

    2017-01-01

    Like many other fruits, table grapes depend on accurate temperature management during transport in maritime refrigerated containers. Ideally the temperature inside the container is equal to set point in every location in the container. Unfortunately door-end temperatures are always higher due to

  17. Electrical transport in La1−xCaxMnO3 thin films at low temperatures

    Indian Academy of Sciences (India)

    Electrical transport in La1−xCaxMnO3 thin films at low temperatures. S ANGAPPANE, K SETHUPATHI and G RANGARAJAN. Physics Department, Low Temperature Laboratory, Indian Institute of Technology,. Chennai 600 036, India. Abstract. We report here the low-temperature resistivity of the chemical solution deposited.

  18. Intermediates and transport phenomena in two-temperature synthesis of ZnGeP{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Meng; Yang, Chun-Hui; Lei, Zuo-Tao; Xia, Shi-Xing; Zhu, Chong-Qiang; Sun, Liang; Zhou, Yu-Xiang [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin (China)

    2010-01-15

    High quality semiconducting ternary compound ZnGeP{sub 2} was synthesized by a modified two-temperature technique using high purity elemental zinc, germanium and phosphorus as the starting materials. Transport phenomena of zinc and phosphorus vapors and the major reaction intermediates, taking place in ZnGeP{sub 2} formation, were studied by interrupting the synthesis process using quenching technique as well as by adjusting the temperatures of cold and hot zones. The powder X-ray diffraction analysis showed that the major reaction intermediates were ZnP{sub 2}, Zn{sub 3}P{sub 2}, and GeP, which proportions were changed at the different temperature stages. ZnP{sub 2} was formed in the temperature gradient region and ZnGeP{sub 2} was formed in the hot zone when the temperature of the hot zone was higher than 900 C. The 520-1040 C temperature profile was chosen for the ZnGeP{sub 2} synthesis and charge amount per run reached 200 g. The powder X-ray diffraction pattern of the synthesized ZnGeP{sub 2} compound was in agreement with the standard pattern of ZnGeP{sub 2}. These results demonstrated that the synthesized ZnGeP{sub 2} compound was a single phase. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Electronic spin transport and spin precession in single graphene layers at room temperature.

    Science.gov (United States)

    Tombros, Nikolaos; Jozsa, Csaba; Popinciuc, Mihaita; Jonkman, Harry T; van Wees, Bart J

    2007-08-02

    Electronic transport in single or a few layers of graphene is the subject of intense interest at present. The specific band structure of graphene, with its unique valley structure and Dirac neutrality point separating hole states from electron states, has led to the observation of new electronic transport phenomena such as anomalously quantized Hall effects, absence of weak localization and the existence of a minimum conductivity. In addition to dissipative transport, supercurrent transport has also been observed. Graphene might also be a promising material for spintronics and related applications, such as the realization of spin qubits, owing to the low intrinsic spin orbit interaction, as well as the low hyperfine interaction of the electron spins with the carbon nuclei. Here we report the observation of spin transport, as well as Larmor spin precession, over micrometre-scale distances in single graphene layers. The 'non-local' spin valve geometry was used in these experiments, employing four-terminal contact geometries with ferromagnetic cobalt electrodes making contact with the graphene sheet through a thin oxide layer. We observe clear bipolar (changing from positive to negative sign) spin signals that reflect the magnetization direction of all four electrodes, indicating that spin coherence extends underneath all of the contacts. No significant changes in the spin signals occur between 4.2 K, 77 K and room temperature. We extract a spin relaxation length between 1.5 and 2 mum at room temperature, only weakly dependent on charge density. The spin polarization of the ferromagnetic contacts is calculated from the measurements to be around ten per cent.

  20. Advanced Intermediate Heat Transport Loop Design Configurations for Hydrogen Production Using High Temperature Nuclear Reactors

    International Nuclear Information System (INIS)

    Chang Oh; Cliff Davis; Rober Barner; Paul Pickard

    2005-01-01

    The US Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the high-temperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant (NGNP), may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood. A number of possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermal-hydraulic evaluations and cycle-efficiency evaluations of the different configurations and coolants. The thermal-hydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. The relative sizes of components provide a relative indication of the capital cost associated with the various configurations. Estimates of the overall cycle efficiency of the various

  1. A computational fluid dynamics and effectiveness-NTU based co-simulation approach for flow mal-distribution analysis in microchannel heat exchanger headers

    International Nuclear Information System (INIS)

    Huang, Long; Lee, Moon Soo; Saleh, Khaled; Aute, Vikrant; Radermacher, Reinhard

    2014-01-01

    Refrigerant flow mal-distribution is a practical challenge in most microchannel heat exchangers (MCHXs) applications. Geometry design, uneven heat transfer and pressure drop in the different microchannel tubes are three main reasons leading to the flow mal-distribution. To efficiently and accurately account for these three effects, a new MCHX co-simulation approach is proposed in this paper. The proposed approach combines a detailed header simulation based on computational fluid dynamics (CFD) and a robust effectiveness-based finite volume tube-side heat transfer and refrigerant flow modeling tool. The co-simulation concept is demonstrated on a ten-tube MCHX case study. Gravity effect and uneven airflow effect were numerically analyzed using both water and condensing R134a as the working fluids. The approach was validated against experimental data for an automotive R134a condenser. The inlet header was cut open after the experimental data had been collected. The detailed header geometry was reproduced using the proposed CFD header model. Good prediction accuracy was achieved compared to the experimental data. The presented co-simulation approach is capable of predicting detailed refrigerant flow behavior while accurately predicts the overall heat exchanger performance. - Highlights: •MCHX header flow distribution is analyzed by a co-simulation approach. •The proposed method is capable of simulating both single-phase and two-phase flow. •An actual header geometry is reproduced in the CFD header model. •The modeling work is experimentally validated with good accuracy. •Gravity effect and air side mal-distribution are accounted for

  2. Current transport in Zn/p-Si(100) Schottky barrier diodes at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Karatas, S. [Department of Physics, Faculty of Sciences and Arts, Kahramanmaras Suetcue imam University, 46100 Kahramanmaras (Turkey)]. E-mail: skaratas@ksu.edu.tr; Altindal, S. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500, Ankara (Turkey); Cakar, M. [Department of Chemistry, Faculty of Sciences and Arts, Kahramanmaras Suetcue imam University, 46100 Kahramanmaras (Turkey)

    2005-03-15

    In this study, we have performed behavior of the non-ideal forward bias current-voltage (I-V) and the reverse bias capacitance-voltage (C-V) characteristics of Zn/p-Si (metal-semiconductor) Schottky barrier diode (SBDs) with thin interfacial insulator layer. The forward bias I-V and reverse bias C-V characteristics of SBDs have been studied at the temperatures range of 300-400K. SBD parameters such as ideality factor n, the series resistance (R{sub S}) determined Cheung's functions and Schottky barrier height, {phi}{sub b}, are investigated as functions of temperature. The ideality factor n and R{sub S} were strongly temperature dependent and changed linearly with temperature and inverse temperature, respectively. The zero-bias barrier heights {phi}{sub b0}(I-V) calculated from I-V measurements show an unusual behavior that it was found to increase linearly with the increasing temperature. However, the barrier height {phi}{sub b}(C-V) calculated from C-V measurements at 500kHz frequency decreased linearly with the increasing temperature. The correlation between {phi}{sub b0}(I-V) and {phi}{sub b}(C-V) barrier heights have been explained by taking into account ideality factors n and the tunneling factor ({alpha}{chi}{sup 1/2}{delta}) in the current transport mechanism. Also, the temperature dependence of energy distribution of interface state density (N{sub SS}) was determined from the forward I-V measurements by taking into account the bias dependence of the effective barrier height. The higher values of n and R{sub S} were attributed to the presence of a native insulator on Si surface and to high density of interface states localized at semiconductor-native oxide layer (Si/SiO{sub 2}) interface.

  3. CONTAIN model for simulation of accident localisation system at Ignalina NPP in the case of pressure header rupture

    International Nuclear Information System (INIS)

    Rimkevichius, S.; Chesna, B.

    1997-01-01

    Accident localisation system (ALS) at the Ignalina NPP is a system of rooms intended to reduce the pressure inside the rooms and to limit the release of radiation in the case of loose of coolant accident (LOCA). The analysis of effectiveness of ALS and results of calculations in the case of pressure header (PH) rupture using the code CONTAIN (USA) are described in this paper. The calculations were performed using mass and energy release from the broken PH function obtained from RELAP5 (USA) code calculations. Comparative calculations using design function were performed as well. The balance of energy is analyzed. (author). 12 refs., 3 tab., 13 figs

  4. Precipitation, temperature, and moisture transport variations associated with two distinct ENSO flavors during 1979-2014

    Science.gov (United States)

    Gu, Guojun; Adler, Robert F.

    2016-11-01

    Interannual precipitation and temperature variations during 1979-2014 are investigated by examining the effects of two distinct flavors of the El Niño-Southern Oscillation (ENSO), i.e., the tropical eastern Pacific (EP) and central Pacific (CP) ENSO events. Satellite- and ground-based observations with global coverage are applied including the monthly precipitation data from the Global Precipitation Climatology Project (GPCP) and surface temperature anomalies from the NASA-GISS surface temperature anomaly analysis. Related variations in other water-cycle components including atmospheric moisture transport are also examined by using the outputs from the NASA-Modern Era Retrospective-analysis for Research and Applications (MERRA). While the second leading mode from an EOF analysis of sea surface temperature (SST) anomalies between 30°N and 30°S is dominated by interdecadal-scale variability that is not a focus of this study, the first and third leading modes represent well the EP and CP events, respectively. The corresponding principal components (PC1 and PC3) are then applied as indices to estimate the influences of the two ENSO flavors on various physical components through linear regression. Because of their distinct SST configurations in the tropical Pacific, the two ENSO flavors manifest different spatial features of precipitation anomalies as shown in past studies. Differences can also be readily seen in satellite-retrieved tropospheric layered temperatures and oceanic columnar water vapor content. General agreements between observations and MERRA outputs can be obtained as judged by consistent respective anomalies corresponding to the two ENSO flavors, suggesting that MERRA could provide an accurate account of variations on the interannual time scale. Interannual variations in MERRA vertically integrated moisture transport (VIMT) are further examined to explore possible relations between precipitation and tropospheric moisture transport corresponding to the

  5. Trap density of states in n-channel organic transistors: variable temperature characteristics and band transport

    International Nuclear Information System (INIS)

    Cho, Joung-min; Akiyama, Yuto; Kakinuma, Tomoyuki; Mori, Takehiko

    2013-01-01

    We have investigated trap density of states (trap DOS) in n-channel organic field-effect transistors based on N,N ’-bis(cyclohexyl)naphthalene diimide (Cy-NDI) and dimethyldicyanoquinonediimine (DMDCNQI). A new method is proposed to extract trap DOS from the Arrhenius plot of the temperature-dependent transconductance. Double exponential trap DOS are observed, in which Cy-NDI has considerable deep states, by contrast, DMDCNQI has substantial tail states. In addition, numerical simulation of the transistor characteristics has been conducted by assuming an exponential trap distribution and the interface approximation. Temperature dependence of transfer characteristics are well reproduced only using several parameters, and the trap DOS obtained from the simulated characteristics are in good agreement with the assumed trap DOS, indicating that our analysis is self-consistent. Although the experimentally obtained Meyer-Neldel temperature is related to the trap distribution width, the simulation satisfies the Meyer-Neldel rule only very phenomenologically. The simulation also reveals that the subthreshold swing is not always a good indicator of the total trap amount, because it also largely depends on the trap distribution width. Finally, band transport is explored from the simulation having a small number of traps. A crossing point of the transfer curves and negative activation energy above a certain gate voltage are observed in the simulated characteristics, where the critical V G above which band transport is realized is determined by the sum of the trapped and free charge states below the conduction band edge

  6. Charge transport mechanism and low temperature phase transitions in KIO3

    Science.gov (United States)

    Abdel Kader, M. M.; El-Kabbany, F.; Naguib, H. M.; Gamal, W. M.

    2013-04-01

    Our report deals with the measurement of some electrical properties, namely the ac conductivity σ(ω,T) and the complex dielectric permittivity epsilon*(ω, T) in the temperature interval 95K < T < 280K and at some selected frequencies (0.7kHz - 20kHz) for polycrystalline samples of potassium iodate KIO3 using a computerized RLC meter. The improper character of the ferroelectricity over the mentioned temperature range has been achieved by recording the ferroelectric hysteresis loops. The temperature dependence of each electrical parameter reveals that the compound undergoes two phase transitions at T ≈ 258K and at T ≈ 110K. The frequency dependent conductivity seems to be in accordance with the power law σ(ω,T)αωs(T) and the trend of temperature dependence of the frequency exponent s (0 < s < 1) suggests that the quantum mechanical tunneling (QMT) model is the main mechanism of the charge transport. Comparison with the behavior of the NH4IO3 in the same temperature range was outlined.

  7. The effect of temperature on the photosynthesis and 14C-photosynthetic products transportation and distribution in cucumber

    International Nuclear Information System (INIS)

    Shi Yuelin; Sun Yiezhi; Xu Guimin; Cai Qiyun

    1991-01-01

    The optimum temperature of photosynthesis tended to become higher following the growth of cucumber. The optimum temperature was 30 deg C at the early growth stage and 35 deg C at the late growth stage. Stomatal resistance decreased and transpiration rate increased with increasing of the temperature. Most of the 14 C-photosynthetic products in leaves were transported out at 30 deg C during the day. After one night, more photosynthetic products were transported out under higher temperature. From the early to the middle growth stage, most of the 14 C-photosynthetic products were transported to fruits at 30 deg C. But caulis, leaves and apical point obtained most of the photosynthetic products at 35 deg C. At the late growth stage, most of the 14 C-photosynthetic products were transported to fruits at 35 deg c. At 25 deg C, caulis and leaves got more 14 C-photosynthetic products

  8. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 4: Compositions corresponding to Rankine temperature schedules in part 3

    Science.gov (United States)

    Gordon, S.

    1982-01-01

    The equilibrium compositions corresponding to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. The compositions presented correspond to Rankine temperature schedules.

  9. Self-consistent transport coefficients for average collective motion at moderately high temperatures

    International Nuclear Information System (INIS)

    Yamaji, Shuhei; Hofmann, H.; Samhammer, R.

    1987-01-01

    Linear response theory is applied to compute the coefficients for inertia, friction and local stiffness for slow, large scale nuclear collective motion. It is shown how these coefficients can be defined within a locally harmonic approximation. The latter allows to study the implications arising from a finite local collective frequency. It is only for temperatures around 2 MeV that the zero frequency limit becomes a fair approximation. Friction is found to have a marked temperature dependence. The numerical computations are performed on the basis of a two-center shell model, but allowing the particles and holes to become dressed through effects of the medium. The dependence of the transport coefficients on the parameters of these self-energies is studied. It is argued that the uncertainties are smaller than a factor of 2. (orig.)

  10. Analysis technology on the temperature and thermal stress of the cask for radioactive material transport

    International Nuclear Information System (INIS)

    Shin, L.Y.; Jin, C.Y.; Soo, K.H.; Hwan, C.S.

    2005-01-01

    The cask is used to transport the radioactive materials. It is required to withstand for the thirty minute under the hypothetical fire accident condition of the 800□. According to development of the computer simulation, finite element analysis is applied to the calculation widely. But finite element method for the hypothetical accident conditions is not established in domestic regulations. In this study, the temperature and thermal stress analysis of KSC-4 cask under 800□ fire condition is conducted using by ANSYS 7.0 code. In order to analyze finite elements, two-dimensional model of KSC-4 cask is used. Symmetric boundary, convection, and radiation condition are applied in the analysis. As the results, maximum temperature and thermal stress of the KSC-4 cask is evaluated. (orig.)

  11. Low-Temperature Carrier Transport in Ionic-Liquid-Gated Hydrogen-Terminated Silicon

    Science.gov (United States)

    Sasama, Yosuke; Yamaguchi, Takahide; Tanaka, Masashi; Takeya, Hiroyuki; Takano, Yoshihiko

    2017-11-01

    We fabricated ionic-liquid-gated field-effect transistors on the hydrogen-terminated (111)-oriented surface of undoped silicon. Ion implantation underneath electrodes leads to good ohmic contacts, which persist at low temperatures down to 1.4 K. The sheet resistance of the channel decreases by more than five orders of magnitude as the gate voltage is changed from 0 to -1.6 V at 220 K. This is caused by the accumulation of hole carriers. The sheet resistance shows thermally activated behavior at temperatures below 10 K, which is attributed to hopping transport of the carriers. The activation energy decreases towards zero with increasing carrier density, suggesting the approach to an insulator-metal transition. We also report the variation of device characteristics induced by repeated sweeps of the gate voltage.

  12. LHCb: Dynamically Adaptive Header Generator and Front-End Source Emulator for a 100 Gbps FPGA Based DAQ

    CERN Multimedia

    Srikanth, S

    2014-01-01

    The proposed upgrade for the LHCb experiment envisages a system of 500 Data sources each generating data at 100 Gbps, the acquisition and processing of which is a big challenge even for the current state of the art FPGAs. This requires an FPGA DAQ module that not only handles the data generated by the experiment but also is versatile enough to dynamically adapt to potential inadequacies of other components like the network and PCs. Such a module needs to maintain real time operation while at the same time maintaining system stability and overall data integrity. This also creates a need for a Front-end source Emulator capable of generating the various data patterns, that acts as a testbed to validate the functionality and performance of the Header Generator. The rest of the abstract briefly describes these modules and their implementation. The Header Generator is used to packetize the streaming data from the detectors before it is sent to the PCs for further processing. This is achieved by continuously scannin...

  13. Pipe and bend erosion by pneumatic transport of solids at high temperature: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Klinzing, G. E.; Borzone, L. A.; Yang, Wen-Ching

    1989-06-01

    The erosion of various components of a pneumatic transport line has been studied through basic experiments, commercial-scale test runs and computer simulation. The main objective was to study the effect of the operating variables on the erosion rates of refractory lined straight sections and bends. Temperatures ranging from 22 to 830/degree/C, gas velocities from 12.9 to 34 m/s and solid flow rates from 48 to 225 kg/h were tested in a High Temperature Pneumatic Transport Test Facility. Four kinds of refractory concretes were used as targets. The erodent materials were river sand, coal slag and alumina. The effect of gas velocity and solids slow rate on the erosion rate was correlated in terms of power laws, while temperature effects proved to be more complex, since mechanical properties of both erodent and target materials change with temperature. The erosion of circular bends was evaluated using a computer model that combines computational particle dynamics and experimental data to predict the erosion pattern inside the bend. Experiments on the erosion of wedge samples, performed in the erosion test facility, and data on particle-wall collisions, obtained with the help of high-speed photographic techniques, were the basic set of data used in the simulation. As an alternative to circular radius bends, and experimental study of wear and flow patterns in blinded T-bends was performed. The internal geometry in this kind of bends was determined by the solids deposition, and complex erosion patterns appeared as the operating variables were manipulated. 81 figs., 50 tabs.

  14. Correlation and transport properties for mixtures at constant pressure and temperature

    Science.gov (United States)

    White, Alexander J.; Collins, Lee A.; Kress, Joel D.; Ticknor, Christopher; Clérouin, Jean; Arnault, Philippe; Desbiens, Nicolas

    2017-06-01

    Transport properties of mixtures of elements in the dense plasma regime play an important role in natural astrophysical and experimental systems, e.g., inertial confinement fusion. We present a series of orbital-free molecular dynamics simulations on dense plasma mixtures with comparison to a global pseudo ion in jellium model. Hydrogen is mixed with elements of increasingly high atomic number (lithium, carbon, aluminum, copper, and silver) at a fixed temperature of 100 eV and constant pressure set by pure hydrogen at 2 g/cm 3 , namely, 370 Mbars. We compute ionic transport coefficients, such as self-diffusion, mutual diffusion, and viscosity for various concentrations. Small concentrations of the heavy atoms significantly change the density of the plasma and decrease the transport coefficients. The structure of the mixture evidences a strong Coulomb coupling between heavy ions and the appearance of a broad correlation peak at short distances between hydrogen atoms. The concept of an effective one component plasma is used to quantify the overcorrelation of the light element induced by the admixture of a heavy element.

  15. Relative turbulent transport efficiency and flux-variance relationships of temperature and water vapor

    Science.gov (United States)

    Hsieh, C. I.

    2016-12-01

    This study investigated the relative transport efficiency and flux-variance relationships of temperature and water vapor, and examined the performance of using this method for predicting sensible heat (H) and water vapor (LE) fluxes with eddy-covariance measured flux data at three different ecosystems: grassland, paddy rice field, and forest.The H and LE estimations were found to be in good agreement with the measurements over the three fields. The prediction accuracy of LE could be improved by around 15% if the predictions were obtained by the flux-variance method in conjunction with measured sensible heat fluxes. Moreover, the paddy rice field was found to be a special case where water vapor follows flux-variance relation better than heat does. The flux budget equations of heat and water vapor were applied to explain this phenomenon. Our results also showed that heat and water vapor were transported with the same efficiency above the grassland and rice paddy. For the forest, heat was transported 20% more efficiently than evapotranspiration.

  16. Temperature modulates the effects of ocean acidification on intestinal ion transport in Atlantic cod, Gadus morhua

    Directory of Open Access Journals (Sweden)

    Marian Yong-An Hu

    2016-06-01

    Full Text Available CO2-driven seawater acidification has been demonstrated to enhance intestinal bicarbonate secretion rates in teleosts, leading to an increased release of CaCO3 under simulated ocean acidification scenarios. In this study, we investigated if increasing CO2 levels stimulate the intestinal acid–base regulatory machinery of Atlantic cod (Gadus morhua and whether temperatures at the upper limit of thermal tolerance stimulate or counteract ion regulatory capacities. Juvenile G. morhua were acclimated for four weeks to three CO2 levels (550, 1,200 and 2,200 μatm covering present and near-future natural variability, at optimum (10°C and summer maximum temperature (18°C, respectively. Immunohistochemical analyses revealed the subcellular localization of ion transporters, including Na+/K+-ATPase (NKA, Na+/H+-exchanger 3 (NHE3, Na+/HCO3- cotransporter (NBC1, pendrin-like Cl-/HCO3- exchanger (SLC26a6, V-type H+-ATPase subunit a (VHA and Cl- channel 3 (CLC3 in epithelial cells of the anterior intestine. At 10°C, proteins and mRNA were generally up-regulated for most transporters in the intestinal epithelium after acclimation to higher CO2 levels. This supports recent findings demonstrating increased intestinal HCO3- secretion rates in response to CO2 induced seawater acidification. At 18°C, mRNA expression and protein concentrations of most ion transporters remained unchanged or were even decreased, suggesting thermal compensation. This response may be energetically favorable to retain blood HCO3- levels to stabilize pHe, but may negatively affect intestinal salt and water resorption of marine teleosts in future oceans.

  17. Temperature-mediated polymorphism in molecular crystals: The impact on crystal packing and charge transport

    KAUST Repository

    Stevens, Loah A.

    2015-01-13

    We report a novel synthesis to ultra high purity 7,14-bis((trimethylsilyl)ethynyl)dibenzo[b,def]-chrysene (TMS-DBC) and the use of this material in the growth of single crystals by solution and vapor deposition techniques. We observe that the substrate temperature has a dramatic impact on the crystal growth, producing two distinct polymorphs of TMS-DBC; low temperature (LT) fine red needles and high temperature (HT) large yellow platelets. Single crystal X-ray crystallography confirms packing structures where the LT crystals form a 1D slipped-stack structure, while the HT crystals adopt a 2D brickwork motif. These polymorphs also represent a rare example where both are extremely stable and do not interconvert to the other crystal structure upon solvent or thermal annealing. Single crystal organic field-effect transistors of the LT and HT crystals show that the HT 2D brickwork motif produces hole mobilities as high as 2.1 cm2 V-1 s-1, while the mobility of the 1D structure is significantly lower, at 0.028 cm2 V-1 s-1. Electronic-structure calculations indicate that the superior charge transport in the brickwork polymorph in comparison to the slipped-stack polymorph is due to the presence of an increased dimensionality of the charge migration pathways.

  18. Magneto-transport properties of magnetic tunnelling transistors at low and room temperatures

    International Nuclear Information System (INIS)

    Quang, H D; Huu, C X; Oh, S K; Dang, V S; Sinh, N H; Yu, S C

    2006-01-01

    Si(100)/CoFe/AlO x /CoFe/FeMn/Cu/Ta magnetic tunnelling transistors (MTTs) with differing base thicknesses (W) were investigated. The magneto-transport properties of the MTTs were measured at 77 K and room temperature (RT). We obtained magneto-current ratios of 48.3% and 55.9% for emitter-base bias voltages of 1.45 and 2.0 V, respectively, at 77 K. The transfer ratios are 2.83 x 10 -5 and 1.52 x 10 -4 , respectively, corresponding to bias voltages of 1.45 and 2.0 V. Moreover, the highest tunnel magneto-resistance (TMR) ratios turned out to be 12% and 20% for a base thickness of 30 A at RT and 77 K, respectively. These properties raise not only some fundamental questions regarding the phenomenon of spin-independent tunnelling at low and room temperatures, but also show some promising aspect for magneto-electronic applications. In addition, we attempted to elucidate the reason behind the outstanding TMR effect at low and room temperatures. Finally, the origin of the decrease in the mean free path asymmetry (λ↑/λ↓) was clarified by using x-ray photoelectron spectroscopy profile analysis of the elements existing in the interface between Si and the CoFe base (Co, Fe, Al, Si, O)

  19. Epidermal photonic devices for quantitative imaging of temperature and thermal transport characteristics of the skin

    Science.gov (United States)

    Gao, Li; Zhang, Yihui; Malyarchuk, Viktor; Jia, Lin; Jang, Kyung-In; Chad Webb, R.; Fu, Haoran; Shi, Yan; Zhou, Guoyan; Shi, Luke; Shah, Deesha; Huang, Xian; Xu, Baoxing; Yu, Cunjiang; Huang, Yonggang; Rogers, John A.

    2014-09-01

    Characterization of temperature and thermal transport properties of the skin can yield important information of relevance to both clinical medicine and basic research in skin physiology. Here we introduce an ultrathin, compliant skin-like, or ‘epidermal’, photonic device that combines colorimetric temperature indicators with wireless stretchable electronics for thermal measurements when softly laminated on the skin surface. The sensors exploit thermochromic liquid crystals patterned into large-scale, pixelated arrays on thin elastomeric substrates; the electronics provide means for controlled, local heating by radio frequency signals. Algorithms for extracting patterns of colour recorded from these devices with a digital camera and computational tools for relating the results to underlying thermal processes near the skin surface lend quantitative value to the resulting data. Application examples include non-invasive spatial mapping of skin temperature with milli-Kelvin precision (±50 mK) and sub-millimetre spatial resolution. Demonstrations in reactive hyperaemia assessments of blood flow and hydration analysis establish relevance to cardiovascular health and skin care, respectively.

  20. Nanostructures study of CNT nanofluids transport with temperature-dependent variable viscosity in a muscular tube

    Science.gov (United States)

    Akbar, Noreen Sher; Abid, Syed Ali; Tripathi, Dharmendra; Mir, Nazir Ahmed

    2017-03-01

    The transport of single-wall carbon nanotube (CNT) nanofluids with temperature-dependent variable viscosity is analyzed by peristaltically driven flow. The main flow problem has been modeled using cylindrical coordinates and flow equations are simplified to ordinary differential equations using long wavelength and low Reynolds' number approximation. Analytical solutions have been obtained for axial velocity, pressure gradient and temperature. Results acquired are discussed graphically for better understanding. It is observed that with an increment in the Grashof number the velocity of the governing fluids starts to decrease significantly and the pressure gradient is higher for pure water as compared to single-walled carbon nanotubes due to low density. As the specific heat is very high for pure water as compared to the multi-wall carbon nanotubes, it raises temperature of the muscles, in the case of pure water, as compared to the multi-walled carbon nanotubes. Furthermore, it is noticed that the trapped bolus starts decreasing in size as the buoyancy forces are dominant as compared to viscous forces. This model may be applicable in biomedical engineering and nanotechnology to design the biomedical devices.

  1. Thermodynamic properties and transport coefficients of two-temperature helium thermal plasmas

    Science.gov (United States)

    Guo, Xiaoxue; Murphy, Anthony B.; Li, Xingwen

    2017-03-01

    Helium thermal plasmas are in widespread use in arc welding and many other industrial applications. Simulation of these processes relies on accurate plasma property data, such as plasma composition, thermodynamic properties and transport coefficients. Departures from LTE (local thermodynamic equilibrium) generally occur in some regions of helium plasmas. In this paper, properties are calculated allowing for different values of the electron temperature, T e, and heavy-species temperature, T h, at atmospheric pressure from 300 K to 30 000 K. The plasma composition is first calculated using the mass action law, and the two-temperature thermodynamic properties are then derived. The viscosity, diffusion coefficients, electrical conductivity and thermal conductivity of the two-temperature helium thermal plasma are obtained using a recently-developed method that retains coupling between electrons and heavy species by including the electron-heavy-species collision term in the heavy-species Boltzmann equation. It is shown that the viscosity and the diffusion coefficients strongly depend on non-equilibrium ratio θ (θ ={{T}\\text{e}}/{{T}\\text{h}} ), through the plasma composition and the collision integrals. The electrical conductivity, which depends on the electron number density and ordinary diffusion coefficients, and the thermal conductivity have similar dependencies. The choice of definition of the Debye length is shown to affect the electrical conductivity significantly for θ  >  1. By comparing with literature data, it is shown that the coupling between electrons and heavy species has a significant influence on the electrical conductivity, but not on the viscosity. Plasma properties are tabulated in the supplementary data.

  2. The Transport Properties of Sodium Atoms and the Heat Capacity of Sodium Dimers at High Temperatures

    Science.gov (United States)

    Biolsi, L.; Holland, P. M.

    2010-05-01

    Including the contribution of excited state atoms can improve calculations of dilute gaseous transport properties at high temperatures. For sodium, experimental and/or theoretical information is available about the potential energy curves associated with each of ten low-lying states of the sodium dimer. These include the {X1Σ_g{}+} and {3Σ_u{}{}+} states that dissociate to two ground state 2S sodium atoms and the four {3Σ_g,u{}+, 1Σ _g,u{}+, 1Pi _g,u, 3Pi _g,u} gerade/ungerade pairs of states that dissociate to a ground state 2S atom and an excited state 2P atom. Nine of these are bound states and have been fitted with the Hulburt-Hirschfelder potential, a very good general purpose atom-atom potential. The 3Πg state is not bound and has been fitted with the exponential repulsive potential. We have used these potentials to calculate viscosity collision integrals as a function of temperature, and employed degeneracy-weighted averaging to determine the viscosity and translational contribution to the thermal conductivity of the sodium atoms. These same potentials have been used to calculate the heat capacity, {Cp^o}, of the sodium dimer using an approach that depends on the second virial coefficient and its first two temperature derivatives. Again, the inclusion of molecular states that dissociate to an excited state atom allows {Cp^o} to be determined with improved accuracy at higher temperatures. Thus, thermophysical property calculations for sodium have been extended to 25,000 K. These results are compared with previous results, including heat capacities given in the NIST-JANAF Thermochemical Tables.

  3. Transport through dissipative trapped electron mode and toroidal ion temperature gradient mode in TEXTOR

    International Nuclear Information System (INIS)

    Rogister, A.; Hasselberg, G.; Waelbroeck, F.; Weiland, J.

    1987-12-01

    A self-consistent transport code is used to evaluate how plasma confinement in tokamaks is influenced by the microturbulent fields which are excited by the dissipative trapped electron (DTE) instability. As shown previously, the saturation theory on which the code is based has been developed from first principles. The toroidal coupling resulting from the ion magnetic drifts is neglected; arguments are presented to justify this approximation. The numerical results reproduce well the neo-Alcator scaling law observed experimentally - e.g. in TEXTOR - in non detached ohmic discharges, the confinement degradation which results when auxiliary heating is applied, as well as a large number of other experimental observations. We also assess the possible impact of the toroidal ion temperature gradient mode on energy confinement by estimating the ion thermal flux with the help of the mixing length approximation. (orig./GG)

  4. Relap5/Mod3.1 analysis of main steam header rupture in VVER- 440/213 NPP

    Energy Technology Data Exchange (ETDEWEB)

    Kral, P. [Nuclear Research Inst. Rez (Switzerland)

    1995-12-31

    The presentation is focused on two main topics. First the applied modelling of PGV-4 steam generator for RELAP5 code are described. The results of steady-state calculation under reference conditions are compared against measured data. The problem of longitudinal subdivision of SG tubes is analysed and evaluated. Secondly, a best-estimate analysis of main steam header (MSH) rupture accident in WWER-440/213 NPP is presented. The low reliability of initiation of ESFAS signal `MSH Rupture` leads in this accident to big loss of secondary coolant, full depressurization of main steam system, extremely fast cool-down of both secondary and primary system, opening of PRZ SV-bypass valve with later liquid outflow, potential reaching of secondary criticality by failure of HPIS. 7 refs.

  5. Effect of transport, rest period and temperature on pork quality from different countries

    Directory of Open Access Journals (Sweden)

    Juraj MLYNEK

    2013-06-01

    Full Text Available The aim of the experiment was to assess the pig meat quality in relation to preslaughter conditions and import country. In the experiment, the meat quality of 1980 pigs was evaluated. The animals were divided into three groups according to country of import (Slovakia, Hungary and Netherlands. The following pre-slaughter indicators were evaluated: duration of transport, duration of housing, temperature during housing and transport. The meat quality was judged on the basis of the pH1 value measured 45 minutes after the slaughter in the musculus longissimus dorsi pH1 MLD and in the musculus semimembranosus pH1 MSM. The highest frequency of PSE pale, soft, exudative meat in the MLD was in the group of pigs imported from Slovakia 24.13 percent. These pigs had also statistically significant Plt;0.01 the lowest average pH1 MLD 6.05 in comparison with other imports. The incidence of PSE meat in the MSM was in all evaluated groups above 10 percent. Group of pigs from Slovakia had the lowest value of pH1 MSM 6.23 in comparison with other groups of pigs Plt;0.01. Even though the average length of housing in a slaughterhouse was from 11.26 to 15.43 hours high incidence of PSE meat was recorded. However group of pigs with the longest rest period 15.43 hours Netherlands had significantly higher pH1 MLD and pH1 MSM compared to other imports Plt;0.01. From these results can be concluded that the incidence of PSE meat in evaluated groups is relatively high. Prolonging rest period and lower temperatures had positively influence on the incidence of PSE meat and pH value.

  6. Temperature-tunable wettability on a bioinspired structured graphene surface for fog collection and unidirectional transport.

    Science.gov (United States)

    Song, Yun-Yun; Liu, Yan; Jiang, Hao-Bo; Li, Shu-Yi; Kaya, Cigdem; Stegmaier, Thomas; Han, Zhi-Wu; Ren, Lu-Quan

    2018-02-22

    We designed a type of smart bioinspired wettable surface with tip-shaped patterns by combining polydimethylsiloxane (PDMS) and graphene (PDMS/G). The laser etched porous graphene surface can produce an obvious wettability change between 200 °C and 0 °C due to a change in aperture size and chemical components. We demonstrate that the cooperation of the geometrical structure and the controllable wettability play an important role in water gathering, and surfaces with tip-shaped wettability patterns can quickly drive tiny water droplets toward more wettable regions, so making a great contribution to the improvement of water collection efficiency. In addition, due to the effective cooperation between super hydrophobic and hydrophilic regions of the special tip-shaped pattern, unidirectional water transport on the 200 °C heated PDMS/G surface can be realized. This study offers a novel insight into the design of temperature-tunable materials with interphase wettability that may enhance fog collection efficiency in engineering liquid harvesting equipment, and realize unidirectional liquid transport, which could potentially be applied to the realms of microfluidics, medical devices and condenser design.

  7. Temperature and concentration effects on electrolyte transport across porous thin-film composite nanofiltration membranes: Pore transport mechanisms and energetics of permeation.

    Science.gov (United States)

    Sharma, Ramesh R; Chellam, Shankararaman

    2006-06-01

    The influence of temperature and concentration on nanofilter charge density and electrolyte pore transport mechanisms is reported. Crossflow filtration experiments were performed to measure transport of several electrolytes (NaCl, NaNO3, NaClO4, CaCl2, MgCl2, and MgSO4) across two commercially available thin-film composite nanofiltration membranes in the range 5-41 degrees C. Experiments were also performed with selected salts in the range 1-50 meq/L to quantify concentration effects. Three different approaches, irreversible thermodynamics, extended Nernst-Planck formulation, and theory of rate processes, were employed to interpret retentions of these symmetric and asymmetric electrolytes at varying temperature and concentration. Increasing feed water temperature slightly increased electrolyte reflection coefficients and only weakly increased permeability compared with neutral solutes. Electromigration and convection tended to counteract each other at high fluxes explaining the weak temperature dependence of the reflection coefficient. Changes in membrane surface charge density with temperature were attributed to increased adsorption of electrolytes on the polymer constituting the active layer. Activation energy of permeation for charged solutes was primarily determined by the Donnan potential at the membrane-feed water interface. Electrolyte permeation was shown to be an enthalpy-driven process that resulted in small entropy changes. Increasing sorption capacity with temperature and low sorption energies indicated that co-ion sorption on polymeric membranes was an endothermic physicosorption process, which appears to determine temperature dependence of electrolyte permeation at increased feed concentrations.

  8. Transportation of perishable and refrigerated foods in mylar foil bags and insulated containers: a time-temperature study.

    Science.gov (United States)

    Li, Yanyan; Schrade, John P; Su, Haiyan; Specchio, John J

    2014-08-01

    Data are lacking on the temperature changes of food during transport without the use of refrigerated trucks. The purpose of this study was to evaluate the ability of several insulated and noninsulated containers with or without frozen gel packs to keep perishable and refrigerated foods within the temperature safe zone in relationship to duration of transport. The study was designed to duplicate the practices exhibited by customers purchasing perishable food products from a cash-and-carry business. Approximately 40 perishable food items were evaluated. Four types of containers were tested: a mylar foil bag, a commercial insulated bag, a generic insulated bag, and a commercial insulated blanket. Mixed foods were placed into these containers with or without frozen gel packs, transported in unrefrigerated vehicles, and monitored for 4 h for temperature changes. Two environmental temperatures, room temperature of 21.1°C and a stress temperature of 37.8°C, were evaluated. The internal temperature and surface temperature of the food products in these containers increased slowly but remained well below the U.S. Food and Drug Administration Food Code requirements. The various containers were similar in their ability to retain coolness. The presence of frozen gel packs dramatically enhanced the cold-holding capacity of the containers. The temperature of foods increased more rapidly when stressed in a heated environment. The containers tested used with the frozen gel packs can keep the surface and internal temperatures of various perishable foods (starting at 4.4°C or less) within the Food Code recommendation of under 21.1°C for 4 h. Cash-and-carry businesses should strongly encourage their retail customers to utilize these containers with frozen gel packs to safely transport perishable foods.

  9. Improving xylitol production at elevated temperature with engineered Kluyveromyces marxianus through over-expressing transporters.

    Science.gov (United States)

    Zhang, Jia; Zhang, Biao; Wang, Dongmei; Gao, Xiaolian; Hong, Jiong

    2015-01-01

    Three transporter genes including Kluyveromyces marxianus aquaglyceroporin gene (KmFPS1), Candida intermedia glucose/xylose facilitator gene (CiGXF1) or glucose/xylose symporter gene (CiGXS1) were over-expressed in K. marxianus YZJ017 to improve xylitol production at elevated temperatures. The xylitol production of YZJ074 that harbored CiGXF1 was improved to 147.62g/L in Erlenmeyer flask at 42°C. In fermenter, 99.29 and 149.60g/L xylitol were produced from 99.55 and 151.91g/L xylose with productivity of 4.14 and 3.40g/L/h respectively at 42°C. Even at 45°C, YZJ074 could produce 101.30g/L xylitol from 101.41g/L xylose with productivity of 2.81g/L/h. Using fed-batch fermentation through repeatedly adding non-sterilized substrate directly, YZJ074 could produce 312.05g/L xylitol which is the highest yield reported to date. The engineered strains YZJ074 which can produce xylitol at elevated temperatures is an excellent foundation for xylitol bioconversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Transport mechanisms through PE-CVD coatings: influence of temperature, coating properties and defects on permeation of water vapour

    International Nuclear Information System (INIS)

    Kirchheim, Dennis; Jaritz, Montgomery; Hopmann, Christian; Dahlmann, Rainer; Mitschker, Felix; Awakowicz, Peter; Gebhard, Maximilian; Devi, Anjana; Brochhagen, Markus; Böke, Marc

    2017-01-01

    Gas transport mechanisms through plastics are usually described by the temperature-dependent Arrhenius-model and compositions of several plastic layers are represented by the CLT. When it comes to thin films such as plasma-enhanced chemical vapour deposition (PE-CVD) or plasma-enhanced atomic layer deposition (PE-ALD) coatings on substrates of polymeric material, a universal model is lacking. While existing models describe diffusion through defects, these models presume that permeation does not occur by other means of transport mechanisms. This paper correlates the existing transport models with data from water vapour transmission experiments. (paper)

  11. Temperature and Relative Humidity Inside Trailers During Finishing Pig Loading and Transport in Cold and Mild Weather

    Directory of Open Access Journals (Sweden)

    John McGlone

    2014-09-01

    Full Text Available The effect of bedding levels and trailer compartment on internal trailer temperature and relative humidity (RH during loading and transport of finishing pigs was evaluated in cold and mild weather. Three levels of bedding were used in each experiment: 0.6 m3, 1.2 m3, and 2.4 m3. In mild weather, internal temperatures were lower when 1.2 m3 or 2.4 m3 of bedding were used during loading and transport compared to 0.6 m3 (P < 0.05. Internal trailer temperature increased in a quadratic fashion in the top front compartment when 1.2 m3 was used (P < 0.05, and in a linear fashion in the top rear compartment when 2.4 m3 were used in cold weather (P < 0.05. In mild weather, temperature increased linearly in the top front compartment with heavy bedding levels. Relative humidity increased in a linear fashion in the top front compartment with 0.6 m3, bottom front with 1.2 m3, and top front with 1.2 m3 in cold weather (P < 0.05. In general, temperature and RH increased as bedding levels increased in both cold and mild temperatures. Excess bedding can absorb more moisture, resulting in transport loss and decreased animal welfare.

  12. Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature

    Science.gov (United States)

    Eckels, David E.; Hass, William J.

    1989-05-30

    A sample transport, sample introduction, and flame excitation system for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses.

  13. Simulation of uranium transport with variable temperature and oxidation potential: The computer program THCC [Thermo-Hydro-Chemical Coupling

    International Nuclear Information System (INIS)

    Carnahan, C.L.

    1986-12-01

    A simulator of reactive chemical transport has been constructed with the capabilities of treating variable temperatures and variable oxidation potentials within a single simulation. Homogeneous and heterogeneous chemical reactions are simulated at temperature-dependent equilibrium, and changes of oxidation states of multivalent elements can be simulated during transport. Chemical mass action relations for formation of complexes in the fluid phase are included explicitly within the partial differential equations of transport, and a special algorithm greatly simplifies treatment of reversible precipitation of solid phases. This approach allows direct solution of the complete set of governing equations for concentrations of all aqueous species and solids affected simultaneously by chemical and physical processes. Results of example simulations of transport, along a temperature gradient, of uranium solution species under conditions of varying pH and oxidation potential and with reversible precipitation of uraninite and coffinite are presented. The examples illustrate how inclusion of variable temperature and oxidation potential in numerical simulators can enhance understanding of the chemical mechanisms affecting migration of multivalent waste elements

  14. Thermodynamic properties and transport coefficients of a two-temperature polytetrafluoroethylene vapor plasma for ablation-controlled discharge applications

    Science.gov (United States)

    Wang, Haiyan; Wang, Weizong; Yan, Joseph D.; Qi, Haiyang; Geng, Jinyue; Wu, Yaowu

    2017-10-01

    Ablation-controlled plasmas have been used in a range of technical applications where local thermodynamic equilibrium (LTE) is often violated near the wall due to the strong cooling effect caused by the ablation of wall materials. The thermodynamic and transport properties of ablated polytetrafluoroethylene (PTFE) vapor, which determine the flowing plasma behavior in such applications, are calculated based on a two-temperature model at atmospheric pressure. To our knowledge, no data for PTFE have been reported in the literature. The species composition and thermodynamic properties are numerically determined using the two-temperature Saha equation and the Guldberg-Waage equation according to van de Sanden et al’s derivation. The transport coefficients, including viscosity, thermal conductivity and electrical conductivity, are calculated with the most recent collision interaction potentials using Devoto’s electron and heavy-particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) in the frame of the Chapman-Enskog method. Results are computed for different degrees of thermal non-equilibrium, i.e. the ratio of electron to heavy-particle temperatures, from 1 to 10, with electron temperature ranging from 300 to 40 000 K. Plasma transport properties in the LTE state obtained from the present work are compared with existing published results and the causes for the discrepancy analyzed. The two-temperature plasma properties calculated in the present work enable the modeling of wall ablation-controlled plasma processes.

  15. Effect of disorder on carrier transport in ZnO thin films grown by atomic layer deposition at different temperatures

    Science.gov (United States)

    Saha, D.; Das, Amit. K.; Ajimsha, R. S.; Misra, P.; Kukreja, L. M.

    2013-07-01

    We have grown ˜200 nm thick ZnO films on (0001) sapphire substrates using atomic layer deposition at different substrate temperatures ranging from ˜150 to 350 °C. X-ray diffraction and photoluminescence spectra of these films showed that crystalline and compositional native defects were strongly dependent on the substrate temperature. Room temperature Hall measurement showed that all the films were degenerate with carrier concentration exceeding the Mott's critical density nc required for metallic conduction. The lowest value of room temperature resistivity ˜3.6 × 10-3 Ω cm was achieved for the film deposited at ˜200 °C, which had an estimated carrier concentration ˜5.7 × 1019 cm-3 and mobility ˜30 cm2/V s. The films deposited both below and above ˜200 °C showed increased resistivity and decreased mobility presumably due to the intensified defects and deteriorated crystalline quality of these films. To investigate the effect of disorder on the underlying charge transport mechanisms in these films, the electrical resistivity was measured in the temperature range of ˜4.2 to 300 K. The films grown at ˜150, 300, and 350 °C were found to be semiconducting in the entire range of the measurement temperature due to the intensified disorder which impeded the metallic transport in these films. However, the films grown at ˜200 and 250 °C showed a transition from metallic to semiconducting transport behaviour at lower temperatures due to the reduced defects and improved crystalline quality of these films. The observed semiconducting behaviour below the transition temperature for these films could be well explained by considering quantum corrections to the Boltzmann conductivity which includes the effect of disorder induced weak localization and coulomb electron-electron interactions.

  16. Modeling heat and mass transport phenomena at higher temperatures in solar distillation systems - The Chilton-Colburn analogy

    Energy Technology Data Exchange (ETDEWEB)

    Tsilingiris, P.T. [Department of Energy Engineering, Heat Transfer Laboratory, Technological Education Institution of Athens, A. Spyridonos Street, GR 122 10 Egaleo, Athens (Greece)

    2010-02-15

    In the present investigation efforts have been devoted towards developing an analysis suitable for heat and mass transfer processes modeling in solar distillation systems, when they are operating at higher temperatures. For this purpose the use of Lewis relation is not new although its validity is based on the assumptions of identical boundary layer concentration and temperature distributions, as well as low mass flux conditions, which are not usually met in solar distillation systems operating at higher temperatures associated with considerable mass transfer rates. The present analysis, taking into consideration these conditions and the temperature dependence of all pertinent thermophysical properties of the saturated binary mixture of water vapor and dry air, leads to the development of an improved predictive accuracy model. This model, having undergone successful first order validation against earlier reported measurements from the literature, appears to offer more accurate predictions of the transport processes and mass flow rate yield of solar stills when operated at elevated temperatures. (author)

  17. Transportation

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Here is the decree of the thirtieth of July 1998 relative to road transportation, to trade and brokerage of wastes. It requires to firms which carry out a road transportation as well as to traders and to brokers of wastes to declare their operations to the prefect. The declaration has to be renewed every five years. (O.M.)

  18. Kinetics of bicarbonate transport in human red blood cell membranes at body temperature.

    Science.gov (United States)

    Gasbjerg, P K; Knauf, P A; Brahm, J

    1996-12-01

    We studied unidirectional [14C]HCO3- efflux from human resealed red cell ghosts with 1 mM acetazolamide under self-exchange conditions at pH = pH(i = o) 7.4-9.0 and 0-38 degrees C by means of the Millipore-Swinnex and continuous flow tube filtering techniques. 14CO2 loss from cells to efflux medium and further to the atmosphere was insignificant. [14C]HCO3- efflux was determined at pH 7.8, 38 degrees C under symmetric variation of the HCO3- concentrations (C(i = o)), and asymmetric conditions: C(i) varied, C(o) constant, or C(o) varied, C(i) constant. MM-fit, Jeff = Jmaxeff x C x (C + K1/2)-1, used to describe the concentration dependence of Jeff,o when only C(o) varied, yields at C(i) = 50 mM: K1/2o = 3.8 mMJ, Jmaxeff.o = 20 nmol cm-2 s-1; at C(i) = 165 mM: K1/2o = 10 mM, Jmaxeff.o = 32 nmol cm-2 s-1. When C(i) varied, noncompetitive self inhibition by HCO3- binding (inhibitor constant K1) to an intracellular site was included (MS-fit). Under conditions of (a) symmetry: C(i = o) = 9-600 mM, K1/2s = 173 mM, K1 = 172 mM, and Jmaxeff,s = 120 nmol cm-2 s-1, (b) asymmetry: C(o) = 50 mM, K1/2i = 116 mM, K1 = 136 mM, and Jmaxeff,i = 92 nmol cm-2 s-1. All flux parameters accord with the ping-pong model for anion exchange. The data for C(i) temperature at 0-38 degrees C, indicating that the transmembrane anion transport is controlled by several rate constants with different temperature dependencies. Jeff,s was not significantly affected by increasing pH(i = o) from 7.4 to 7.8, but it decreased by 50% when pH was raised to 9.0.

  19. Gap structure of iron-pnictide superconductors from low-temperature heat transport

    Science.gov (United States)

    Reid, Jean-Philippe

    2010-03-01

    The structure of the superconducting gap provides important clues on the symmetry of the order parameter and the pairing mechanism. Here I describe how measurements of the thermal conductivity at very low temperature can be used to determine whether nodes are present in the gap function of a particular superconductor, and how the application of a magnetic field probes the low-energy quasiparticle excitations. Measurements on hole-doped and electron-doped pnictide superconductors, Ba1-xKxFe2As2 [1] and Ba(Fe1-xCox)2As2 [2], reveal a negligible residual linear term at T->0, showing that the gap of these two superconductors has no nodes, at least in the basal plane. In both pnictides, a small field is found to be very effective in exciting quasiparticles, showing that the gap must be very small in some direction on the Fermi surface. In Ba(Fe1-xCox)2As2, the evolution with doping x is as follows: at low x, the gap is large everywhere on the Fermi surface, and beyond optimal doping the minimum gap becomes progressively smaller. I discuss what these features tell us about the nature of the superconducting state in pnictide superconductors. * Measurements of heat transport performed in collaboration with X.-G. Luo, H. Shakeripour, M.A. Tanatar, N. Doiron-Leyraud and L. Taillefer. [1] X.-G. Luo et al., Phys. Rev. B 80, 140503 (2009). [2] M.A. Tanatar et al., arXiv:0907.1276.

  20. Evidence for modified transport due to sheared E x B flows in high-temperature plasmas

    International Nuclear Information System (INIS)

    Groebner, R.J.; Burrell, K.H.; Austin, M.E.

    1994-11-01

    Sheared mass flows are generated in many fluids and are often important for the dynamics of instabilities in these fluids. Similarly, large values of the E x B velocity have been observed in magnetic confinement machines and there is theoretical and experimental evidence that sufficiently large shear in this velocity may stabilize important instabilities. Two examples of this phenomenon have been observed in the DIII-D tokamak. In the first example, sufficient heating power can lead to the L-H transition, a rapid improvement in confinement in the boundary layer of the plasma. For discharges with heating power close to the threshold required to get the transition, changes in the edge radial electric field are observed to occur prior to the transition itself. In the second example, certain classes of discharges with toroidal momentum input from neutral beam injection exhibit a further improvement of confinement in the plasma core leading to a regime called the VH-mode. In both examples, the region of improved confinement is characterized by an increase of shear in the radial electric field E r , reduced levels of turbulence and increases in gradients of temperatures and densities. These observations are consistent with the hypothesis that the improved confinement is caused by an increase in shear of the E x B velocity which leads to a reduction of turbulence. For the VH-mode, the dominant term controlling E r is the toroidal rotation v φ , indicating that the E r profile is controlled by the source and transport of toroidal momentum

  1. Application of the Finite Elemental Analysis to Modeling Temperature Change of the Vaccine in an Insulated Packaging Container during Transport.

    Science.gov (United States)

    Ge, Changfeng; Cheng, Yujie; Shen, Yan

    2013-01-01

    This study demonstrated an attempt to predict temperatures of a perishable product such as vaccine inside an insulated packaging container during transport through finite element analysis (FEA) modeling. In order to use the standard FEA software for simulation, an equivalent heat conduction coefficient is proposed and calculated to describe the heat transfer of the air trapped inside the insulated packaging container. The three-dimensional, insulated packaging container is regarded as a combination of six panels, and the heat flow at each side panel is a one-dimension diffusion process. The transit-thermal analysis was applied to simulate the heat transition process from ambient environment to inside the container. Field measurements were carried out to collect the temperature during transport, and the collected data were compared to the FEA simulation results. Insulated packaging containers are used to transport temperature-sensitive products such as vaccine and other pharmaceutical products. The container is usually made of an extruded polystyrene foam filled with gel packs. World Health Organization guidelines recommend that all vaccines except oral polio vaccine be distributed in an environment where the temperature ranges between +2 to +8 °C. The primary areas of concern in designing the packaging for vaccine are how much of the foam thickness and gel packs should be used in order to keep the temperature in a desired range, and how to prevent the vaccine from exposure to freezing temperatures. This study uses numerical simulation to predict temperature change within an insulated packaging container in vaccine cold chain. It is our hope that this simulation will provide the vaccine industries with an alternative engineering tool to validate vaccine packaging and project thermal equilibrium within the insulated packaging container.

  2. Implementation of Fully Coupled Heat and Mass Transport Model to Determine Temperature and Moisture State at Elevated Temperatures

    DEFF Research Database (Denmark)

    Pecenko, R.; Hozjan, Tomaz; Svensson, Staffan

    2014-01-01

    The aim of this study is to present precise numerical formulation to determine temperature and moisture state of timber in the situation prior pyrolysis. The strong formulations needed for an accurate description of the physics are presented and discussed as well as their coupling terms. From the...

  3. Pacemaker syndrome with sub-acute left ventricular systolic dysfunction in a patient with a dual-chamber pacemaker: consequence of lead switch at the header.

    Science.gov (United States)

    Khurwolah, Mohammad Reeaze; Vezi, Brian Zwelethini

    In the daily practice of pacemaker insertion, the occurrence of atrial and ventricular lead switch at the pacemaker box header is a rare and unintentional phenomenon, with less than five cases reported in the literature. The lead switch may have dire consequences, depending on the indication for the pacemaker. One of these consequences is pacemaker syndrome, in which the normal sequence of atrial and ventricular activation is impaired, leading to sub-optimal ventricular filling and cardiac output. It is important for the attending physician to recognise any worsening of symptoms in a patient who has recently had a permanent pacemaker inserted. In the case of a dual-chamber pacemaker, switching of the atrial and ventricular leads at the pacemaker box header should be strongly suspected. We present an unusual case of pacemaker syndrome and right ventricular-only pacinginduced left ventricular systolic dysfunction in a patient with a dual-chamber pacemaker.

  4. Transportation

    National Research Council Canada - National Science Library

    Allshouse, Michael; Armstrong, Frederick Henry; Burns, Stephen; Courts, Michael; Denn, Douglas; Fortunato, Paul; Gettings, Daniel; Hansen, David; Hoffman, Douglas; Jones, Robert

    2007-01-01

    .... The ability of the global transportation industry to rapidly move passengers and products from one corner of the globe to another continues to amaze even those wise to the dynamics of such operations...

  5. Temperature dependent current transport properties in Cu{sub 2}ZnSnS{sub 4} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Danilson, Mati, E-mail: mati.danilson@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Kask, Erkki, E-mail: erkki.kask@ttu.ee [Department of Physics, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Pokharel, Nikhil, E-mail: pokharel.nikhil@gmail.com [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Department of Natural Sciences (Physics), Kathmandu University, PO Box 6250 Dhulikhel (Nepal); Grossberg, Maarja, E-mail: Maarja.Grossberg@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Kauk-Kuusik, Marit, E-mail: marit.kauk-kuusik@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Varema, Tiit, E-mail: Tiit.Varema@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krustok, Jüri, E-mail: juri.krustok@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Department of Physics, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

    2015-05-01

    Quaternary semiconductor compound Cu{sub 2}ZnSnS{sub 4} (CZTS) is a promising non-toxic absorber material for solar cells made from earth abundant elements. In this study temperature dependencies (T = 10-300 K) of current-voltage (J-V) characteristics and external quantum efficiency (EQE) spectra of CZTS monograin layer solar cells were measured in order to clarify current transport in CZTS that is still not fully understood. Three different temperature ranges can be distinguished from the temperature dependence of the series resistance (R{sub s}) obtained from J-V measurements and the effective bandgap energy (E{sub g}{sup ⁎}) determined from the EQE spectra. Thermally activated conductivity, Mott's variable-range hopping conductivity, and very low temperature (< 40 K) blocking of the interface recombination were observed. - Highlights: • Cu{sub 2}ZnSnS{sub 4} monograin layer solar cell temperature dependent parameters were studied. • Thermally activated conductivity at temperatures T > 90 K • Mott's variable-range hopping conductivity at temperatures T = 90-40 K • Very low temperature (< 40 K) blocking of interface recombination was observed.

  6. Thermophilic P-loop transport ATPases : Enzyme function and energetics at high temperature

    NARCIS (Netherlands)

    Pretz, Monika Gyöngyi

    2007-01-01

    Primary transport ATPases are divided into several superfamilies; amongst others including ATPases of the ABC transporter superfamily, the F-ATPase superfamily or the motor ATPases of the General Secretory (Sec) pathway. Motor proteins from these superfamilies show a low sequence similarity, except

  7. The transport phenomena during the growth of ZnTe crystal by the temperature gradient solution growth technique

    Science.gov (United States)

    Yin, Liying; Jie, Wanqi; Wang, Tao; Zhou, Boru; Yang, Fan

    2017-03-01

    A numerical model is developed to simulate the temperature field, the thermosolutal convection, the solute segregation and the growth interface morphology during the growth of ZnTe crystal from Te rich solution by the temperature gradient solution growth (TGSG) technique. Effects of the temperature gradient on the transport phenomena, the growth interface morphology and the growth rate are examined. The influences of the latent heat and the thermal conductivity of ZnTe crystal on the transport phenomena and the growth interface are also discussed. We find that the mass transfer of ZnTe in the solution is very slow because of the low diffusion coefficient and the lack of mixing in the lower part of the solution. During the growth, dilute solution with high density and low growth temperature accumulates in the central region of the growth interface, making the growth interface change into two distinct parts. The inner part is very concave, while the outer part is relatively flat. Growth conditions in front of the two parts of the growth interface are different. The crystalline quality of the inner part of the ingot is predicted to be worse than that of the outer part. High temperature gradient can significantly increase the growth rate, and avoid the diffusion controlled growth to some extent.

  8. Transport current density at temperatures up to 25 K of Cu/Ag composite sheathed 122-type tapes and wires

    Science.gov (United States)

    Liu, Shifa; Lin, Kaili; Yao, Chao; Zhang, Xianping; Dong, Chiheng; Wang, Dongliang; Awaji, Satoshi; Kumakura, Hiroaki; Ma, Yanwei

    2017-11-01

    The fabrication of iron-based superconductors with high transport critical current density (J c) and low cost is a crucial determinant of whether they can be used for practical applications. In this paper, Cu/Ag composite sheathed Sr0.6K0.4Fe2As2 (Sr122) tapes and Ba0.6K0.4Fe2As2 (Ba122) round wires were fabricated via an ex situ powder-in-tube method and heat-treated by the hot pressing and hot isostatic pressing process respectively. In order to thoroughly reveal the application potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconductors, transport J c of tapes and wires in high fields at temperatures up to 25 K was measured. High transport J c of 4.4 × 104 A cm-2 at 4.2 K and 3.6 × 103 A cm-2 at 20 K in 10 T was achieved in Cu/Ag composite sheathed Sr122 tapes. Transport J c of Ba122 wires is 9.4 × 103 A cm-2 at 4.2 K and 1.9 × 103 A cm-2 at 20 K in 10 T. These results demonstrate the great potential of Cu/Ag composite sheathed ‘122’ iron pnictide superconducting tapes and wires for high-field applications at intermediate temperatures around 20 K, which can be easily obtained by using cryocoolers.

  9. Heat Transport upon River-Water Infiltration investigated by Fiber-Optic High-Resolution Temperature Profiling

    Science.gov (United States)

    Vogt, T.; Schirmer, M.; Cirpka, O. A.

    2010-12-01

    Infiltrating river water is of high relevance for drinking water supply by river bank filtration as well as for riparian groundwater ecology. Quantifying flow patterns and velocities, however, is hampered by temporal and spatial variations of exchange fluxes. In recent years, heat has become a popular natural tracer to estimate exchange rates between rivers and groundwater. Nevertheless, field investigations are often limited by insufficient sensors spacing or simplifying assumptions such as one-dimensional flow. Our interest lies in a detailed local survey of river water infiltration at a restored river section at the losing river Thur in northeast Switzerland. Here, we measured three high-resolution temperature profiles along an assumed flow path by means of distributed temperature sensing (DTS) using fiber optic cables wrapped around poles. Moreover, piezometers were equipped with standard temperature sensors for a comparison to the DTS data. Diurnal temperature oscillations were tracked in the river bed and the riparian groundwater and analyzed by means of dynamic harmonic regression and subsequent modeling of heat transport with sinusoidal boundary conditions to quantify seepage velocities and thermal diffusivities. Compared to the standard temperature sensors, the DTS data give a higher vertical resolution, facilitating the detection of process- and structure-dependent patterns of the spatiotemporal temperature field. This advantage overcompensates the scatter in the data due to instrument noise. In particular, we could demonstrate the impact of heat conduction through the unsaturated zone on the riparian groundwater by the high resolution temperature profiles.

  10. New applications of high-temperature solar energy for the production of transportable fuels and chemicals and for energy storage

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-19

    The solar fuels and chemicals study was limited to the examination of processes requiring temperatures in excess of 1000/sup 0/K since lower temperature processes had already been examined in studies concerned with the application of waste heat from nuclear power plants to industrial processes. In developing the carbon cycle processes, the primary activity included an extensive literature search and the thermodynamic evaluation of a number of candidate chemical cycles. Although both hydrogen and carbon closed- and open-loop chemical cycles were studied, it was concluded that the carbon cycles offered sufficient additional potential to warrant concentrating on them in subsequent work. The section on new ideas for transportable fuels presents the elements of a new concept for a carbon cycle recovery technique to produce transportable fuels. The elements discussed are sources of carbon dioxide, solar energy reduction of CO/sub 2/, potential carbon cycles, and use of carbon monoxide as fuel and feedstocks. Another section presents some new concepts for the use of high-temperature solar energy in the production of essential materials and for closed-loop chemical storage, as well as for the production of hydrogen as a fuel and open-loop applications. Potential problem areas pertinent to solar-derived fuels and chemicals have been identified. These problems are primarily associated with the limited high temperature experience in industry and include materials compatibility, separation of reaction products, development of solid electrolytes and high-temperature electrodes, selective emission of receiver coatings at high temperature, and a lack of chemical kinetics data, and high-temperature thermodynamic data.

  11. Effects of temperature on bacterial transport and destruction in bioretention media: field and laboratory evaluations.

    Science.gov (United States)

    Zhang, Lan; Seagren, Eric A; Davis, Allen P; Karns, Jeffrey S

    2012-06-01

    Microbial activities are significantly influenced by temperature. This study investigated the effects of temperature on the capture and destruction of bacteria from urban stormwater runoff in bioretention media using 2-year field evaluations coupled with controlled laboratory column studies. Field data from two bioretention cells show that the concentration of indicator bacteria (fecal coliforms and Escherichia coli) was reduced during most storm events, and that the probability of meeting specific water quality criteria in the discharge was increased. Indicator bacteria concentration in the input flow typically increased with higher daily temperature. Although bacterial removal efficiency was independent of temperature in the field and laboratory, column tests showed that bacterial decay coefficients in conventional bioretention media (CBM) increase exponentially with elevated temperature. Increases in levels of protozoa and heterotrophic bacteria associated with increasing temperature appear to contribute to faster die-off of trapped E. coli in CBM via predation and competition.

  12. Effects of sintering temperature on structural and electrical transport properties of zinc ferrites prepared by sol-gel route

    International Nuclear Information System (INIS)

    Anis-ur-Rehman, M.; Malik, M.A.; Ahmad, I.; Nasir, S.; Mubeen, M.; Abdullah, A.

    2011-01-01

    The effects of sintering temperature on the structural and electrical transport properties of nanocrystalline zinc ferrites are reported. The zinc ferrites were prepared by WOWS sol-gel synthesis route. The prepared sample was sintered at temperatures 500 deg. C, 700 deg. C and 900 deg. C respectively for 2 h. X-ray Diffraction (XRD) technique was used to describe the structural properties. The crystallite size, lattice parameters and porosity of samples were measured from the analysis of XRD data. The average crystallite size for each sample was measured using the Scherrer formula by considering the most intense (3 1 1) peak. The dielectric constant (e), dielectric loss tangent (tan theta ) and AC electrical conductivity of nanocrystalline Zn ferrites are investigated as a function of frequency and sintering temperature. All the electrical properties are explained in accordance with MaxwellWagner model and Koops phenomenological theory. (author)

  13. Modelling of tokamak plasmas with internal transport barriers using ion temperature gradient based models

    International Nuclear Information System (INIS)

    Kinsey, J.E.; Waltz, R.E.; Staebler, G.M.; St.John, H.

    1999-01-01

    The dynamic formation of an internal transport barrier resulting from an ExB driven bifurcation has been demonstrated in simulations of a DIII-D NCS discharge with an L-mode edge using the GLF23 model. Taking the sources, sinks, equilibrium, and the density profile from a power balance analysis, the thermal and toroidal momentum transport were simultaneously evolved while computing the effects of rotational shear stabilization. As the bifurcation point is approached, the mode growth rate and ExB shear become tangential and the profiles exhibit a dithering behavior. The input power, in particular the toroidal momentum, is sufficient to overcome the ITB threshold and a bifurcation in both the momentum and heat flux is observed. While the ion thermal and momentum transport show an significant improvement in confinement, the electron thermal transport remains anomalous due to the continued presence of the ETG mode. Comparing JET OS discharges to DIII-DNCS discharges, it is found that the ExB shear rate needs to be enhanced by a factor 2.65 in order to obtain profiles consistent with experimental data. Future work will focus on improving the robustness and efficiency of numerical techniques to allow wider application and increased predictive capability needed to conduct power threshold studies of internal transport barriers. (author)

  14. Low temperature transport in p-doped InAs nanowires

    DEFF Research Database (Denmark)

    Upadhyay, Shivendra; Jespersen, Thomas Sand; Madsen, Morten Hannibal

    2013-01-01

    We present low temperature electrical measurements of p-type Indium Arsenide nanowires grown via molecular beam epitaxy using Beryllium as a dopant. Growth of p-type wires without stacking faults is demonstrated. Devices in field-effect geometries exhibit ambipolar behavior, and the temperature...

  15. Concurrent aggregation and transport of graphene oxide in saturated porous media: Roles of temperature, cation type, and electrolyte concentration.

    Science.gov (United States)

    Wang, Mei; Gao, Bin; Tang, Deshan; Yu, Congrong

    2018-01-02

    Simultaneous aggregation and retention of nanoparticles can occur during their transport in porous media. In this work, the concurrent aggregation and transport of GO in saturated porous media were investigated under the conditions of different combinations of temperature, cation type (valence), and electrolyte concentration. Increasing temperature (6-24 °C) at a relatively high electrolyte concentration (i.e., 50 mM for Na + , 1 mM for Ca 2+ , 1.75 mM for Mg 2+ , and 0.03 and 0.05 mM for Al 3+ ) resulted in enhanced GO retention in the porous media. For instance, when the temperature increased from 6 to 24 °C, GO recovery rate decreased from 31.08% to 6.53% for 0.03 mM Al 3+ and from 27.11% to 0 for 0.05 mM Al 3+ . At the same temperature, increasing cation valence and electrolyte concentration also promoted GO retention. Although GO aggregation occurred in the electrolytes during the transport, the deposition mechanisms of GO retention in the media depended on cation type (valence). For 50 mM Na + , surface deposition via secondary minima was the dominant GO retention mechanism. For multivalent cation electrolytes, GO aggregation was rapid and thus other mechanisms such as physical straining and sedimentation also played important roles in controlling GO retention in the media. After passing through the columns, the GO particles in the effluents showed better stability with lower initial aggregation rates. This was probably because less stable GO particles with lower surface charge densities in the porewater were filtered by the porous media, resulting in more stable GO particle with higher surface charge densities in the effluents. An advection-dispersion-reaction model was applied to simulate GO breakthrough curves and the simulations matched all the experimental data well. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Nonlinear features of the electron temperature gradient mode and electron thermal transport in tokamaks

    International Nuclear Information System (INIS)

    Kaw, P.K.; Singh, R.; Weiland, J.G.

    2001-01-01

    Analytical investigations of several linear and nonlinear features of ETG turbulence are reported. The linear theory includes effects such as finite beta induced electromagnetic shielding, coupling to electron magnetohydrodynamic modes like whistlers etc. It is argued that nonlinearly, turbulence and transport are dominated by radially extended modes called 'streamers'. A nonlinear mechanism generating streamers based on a modulational instability theory of the ETG turbulence is also presented. The saturation levels of the streamers using a Kelvin Helmholtz secondary instability mechanism are calculated and levels of the electron thermal transport due to streamers are estimated. (author)

  17. Current transport modeling and experimental study of THz room temperature ballistic deflection transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kaushal, Vikas; Margala, Martin [Department of Electrical and Computer Engineering, University of Massachusetts Lowell, MA, 01854 (United States); Yu Qiaoyan; Ampadu, Paul; Guarino, Gregg; Sobolewski, Roman, E-mail: vikas_kaushal@student.uml.ed [Department of Electrical and Computer Engineering, University of Rochester, NY, 14627 (United States)

    2009-11-15

    In this paper, two different theoretical models, Comsol Multiphysics{sup TM} (a Finite Element Analysis tool), and a field solver Atlas/Blaze from Silvaco, are compared qualitatively to study the effect of the deflector position, its size and electric field on the charge transport and its distribution along the channel, resulting in current outputs and leakages in ballistic deflection transistors (BDT). Silvaco simulations and experimental results were then used to study the lateral charge transport as a result of variation in electric field distribution, which controls the charge current along the channel in BDT. The electric field dependence of gain is also studied with experimental and theoretical results.

  18. Current transport modeling and experimental study of THz room temperature ballistic deflection transistors

    International Nuclear Information System (INIS)

    Kaushal, Vikas; Margala, Martin; Yu Qiaoyan; Ampadu, Paul; Guarino, Gregg; Sobolewski, Roman

    2009-01-01

    In this paper, two different theoretical models, Comsol Multiphysics TM (a Finite Element Analysis tool), and a field solver Atlas/Blaze from Silvaco, are compared qualitatively to study the effect of the deflector position, its size and electric field on the charge transport and its distribution along the channel, resulting in current outputs and leakages in ballistic deflection transistors (BDT). Silvaco simulations and experimental results were then used to study the lateral charge transport as a result of variation in electric field distribution, which controls the charge current along the channel in BDT. The electric field dependence of gain is also studied with experimental and theoretical results.

  19. High temperature structural design and R and Ds for heat transport system components of FBR 'Monju'

    International Nuclear Information System (INIS)

    Sumikawa, Masaharu; Nakagawa, Yukio; Fukuda, Yoshio; Sukegawa, Masayuki; Ishizaki, Tairo.

    1980-01-01

    The machines and equipments of cooling system for the fast breeder prototype reactor ''Monju'' are operated in creep temperature region, and the upper limit temperature to apply the domestic structural design standard for nuclear machines and equipment is exceeded, therefore the guideline for high temperature structural design is being drawn up, reflecting the results of recent research and development, by the Power Reactor and Nuclear Fuel Development Corp. and others. In order to obtain the basic data for the purpose, the tests on the high temperature characteristics of main structural members and structural elements were carried out, and eight kinds of the inelastic structural analysis program ''HI-EPIC'' series were developed, thus the fundamental technologies of structural desigh in non-linear region were established. Also in the non-linear region, enormous physical quantities must be evaluated, and in the design method based on real elastic analysis, many design diagrams must be employed, therefore for the purpose of improving the reliability of evaluation, the automatic evaluation program ''HI-TEP'' was developed, and preparation has been made for the design of actual machines. The high temperature structural design in ''Monju'', the development of inelastic structural analysis program and high temperature structural analysis evaluation program, and the development of high temperature structures and materials are described. (Kako, I.)

  20. Transport properties of N2 gas at cryogenic temperatures. [computation of viscosity and thermal conductivity

    Science.gov (United States)

    Pearson, W. E.

    1974-01-01

    The viscosity and thermal conductivity of nitrogen gas for the temperature range 5 K - 135 K have been computed from the second Chapman-Enskog approximation. Quantum effects, which become appreciable at the lower temperatures, are included by utilizing collision integrals based on quantum theory. A Lennard-Jones (12-6) potential was assumed. The computations yield viscosities about 20 percent lower than those predicted for the high end of this temperature range by the method of corresponding states, but the agreement is excellent when the computed values are compared with existing experimental data.

  1. Colloid-associated plutonium aged at room temperature: evaluating its transport velocity in saturated coarse-grained granites.

    Science.gov (United States)

    Xie, Jinchuan; Lin, Jianfeng; Wang, Yu; Li, Mei; Zhang, Jihong; Zhou, Xiaohua; He, Yifeng

    2015-01-01

    The fate and transport of colloidal contaminants in natural media are complicated by physicochemical properties of the contaminants and heterogeneous characteristics of the media. Size and charge exclusion are two key microscopic mechanisms dominating macroscopic transport velocities. Faster velocities of colloid-associated actinides than that of (3)H2O were consistently indicated in many studies. However, dissociation/dissolution of these sorbed actinides (e.g., Pu and Np), caused by their redox reactions on mineral surfaces, possibly occurred under certain chemical conditions. How this dissolution is related to transport velocities remains unanswered. In this study, aging of the colloid-associated Pu (pseudo-colloid) at room temperature and transport through the saturated coarse-grained granites were performed to study whether Pu could exhibit slower velocity than that of (3)H2O (UPu/UT colloidal granite particles took place during the aging period. The relative velocity of UPu/UT declined from 1.06 (unaged) to 0.745 (135 d) over time. Size exclusion limited to the uncharged nano-sized particles could not explain such observed UPu/UT colloid-associated Pu(IV) was observed in the aged suspensions. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Electronic spin transport and spin precession in single graphene layers at room temperature

    NARCIS (Netherlands)

    Tombros, Nikolaos; Jozsa, Csaba; Popinciuc, Mihaita; Jonkman, Harry T.; van Wees, Bart J.

    2007-01-01

    Electronic transport in single or a few layers of graphene is the subject of intense interest at present. The specific band structure of graphene, with its unique valley structure and Dirac neutrality point separating hole states from electron states, has led to the observation of new electronic

  3. Temperature impact on cementitious materials carbonation - description of water transport influence

    International Nuclear Information System (INIS)

    Drouet, E.

    2010-11-01

    Carbonation is the major cause of degradation of reinforced concrete structures. It leads to rebar corrosion and cracking of the concrete cover. In the framework of radioactive waste management, cement-based materials used as building material for structures or containers would be simultaneously submitted to heating (due to the waste thermal output), subsequent drying and atmospheric carbon dioxide. Such environmental conditions are expected to modify the carbonation mechanisms (with respect to temperature). In order to describe their long-term evolution of material, a double approach was developed, combining the description of carbonation and drying for temperatures up to 80 C to complement available data at ambient temperature. The present work focuses on the durability study of four hardened cement pastes; two of them are derived from the reference formulations selected by Andra (CEM I and CEM V) and a low-pH mix. The first experimental campaign focuses on moisture transfer. The effect of temperature on drying is investigated through water vapour desorption experiments. The first desorption isotherms of four hardened cement pastes was characterized at 20, 50 and 80 C. The results show a significant influence of the temperature. For a given relative humidity (RH) the water content equilibrium is always reduced temperature is increased and the starting point of capillary condensation is shifted towards higher RHs. The experimental campaign is complemented through modelling activities. The impact of temperature on the first desorption isotherms is effectively described using the Clausius-Clapeyron equation (characterization of the isosteric heat of adsorption). The intrinsic permeability to water is evaluated through inverse analysis by reprocessing the experimental weight loss of initially saturated samples submitted to constant environmental conditions. The intrinsic permeability appears to increase with temperature in relation to the observed microstructure

  4. Directional transport of high-temperature Janus droplets mediated by structural topography

    Science.gov (United States)

    Li, Jing; Hou, Youmin; Liu, Yahua; Hao, Chonglei; Li, Minfei; Chaudhury, Manoj K.; Yao, Shuhuai; Wang, Zuankai

    2016-06-01

    Directed motion of liquid droplets is of considerable importance in various water and thermal management technologies. Although various methods to generate such motion have been developed at low temperature, they become rather ineffective at high temperature, where the droplet transits to a Leidenfrost state. In this state, it becomes challenging to control and direct the motion of the highly mobile droplets towards specific locations on the surface without compromising the effective heat transfer. Here we report that the wetting symmetry of a droplet can be broken at high temperature by creating two concurrent thermal states (Leidenfrost and contact-boiling) on a topographically patterned surface, thus engendering a preferential motion of a droplet towards the region with a higher heat transfer coefficient. The fundamental understanding and the ability to control the droplet dynamics at high temperature have promising applications in various systems requiring high thermal efficiency, operational security and fidelity.

  5. Supercurrent transport properties in Nd substituted TlSr2CaCu2O7 high temperature superconductor

    International Nuclear Information System (INIS)

    Andrew Das Arulsamy; Abd Shukor, R.

    1999-01-01

    The transport critical current density, J ct of TI(Sr 1-x Nd x ) 2 CaCu 2 O 7 (x= 0.1, 0.2 and 0.3) high temperature superconductors were measured at various temperatures. X-ray diffraction patterns indicate that all samples consist of mainly of the 1212 phase. The variation of J ct with Nd concentration, temperature and T c were scaled using a universal function. By plotting J ct versus T n c (x) and [1-(T/T c ) 2 ] m , we can divide the temperature dependencies of J ct into two regions. In each region, a linear relationship is suggested to hold between J ct and [1-(T/T c ) 2 ] m . For x=0.1, a relatively large exponent m in the range 40 - 50 K is observed, but a lower value is observed for a higher temperature range, 55 - 60 K. Average m for x = 0. 1 in the range 40 - 70 K is 1.8 but for x=0.2 and 0.3, m is 0.6 and 1.2, respectively. This can be interpreted as an indication that there is a change in the elementary flux pinning force which is responsible for sustaining the supercurrent. A self-field approximation indicates that Nd substitution lowers the distance between pinning centers (L c ). (author)

  6. Temperature modulation of oxygen transport in a diving mammal (Balaenoptera acutorostrata).

    Science.gov (United States)

    Brix, O; Condò, S G; Bardgard, A; Tavazzi, B; Giardina, B

    1990-10-15

    The functional properties of haemoglobin from the Lesser Rorqual whale (Balaenoptera acutorostrata) have been characterized as a function of the heterotropic effector concentrations and temperature. The results obtained suggest the existence of sophisticated modulation mechanisms based on the interplay of organic phosphates, carbon dioxide, lactate and temperature. These, together with the very small apparent heat of oxygenation (delta H) of oxygen binding, have been physiologically interpreted on the basis of the specific metabolic needs of this diving mammal.

  7. Impact of compression on gas transport in non-woven gas diffusion layers of high temperature polymer electrolyte fuel cells

    Science.gov (United States)

    Froning, Dieter; Yu, Junliang; Gaiselmann, Gerd; Reimer, Uwe; Manke, Ingo; Schmidt, Volker; Lehnert, Werner

    2016-06-01

    Gas transport in non-woven gas diffusion layers of a high-temperature polymer electrolyte fuel cell was calculated with the Lattice Boltzmann method. The underlying micro structure was taken from two sources. A real micro structure was analyzed in the synchrotron under the impact of a compression mask mimicking the channel/rib structure of a flow field. Furthermore a stochastic geometry model based on synchrotron X-ray tomography studies was applied. The effect of compression is included in the stochastic model. Gas transport in these micro structures was simulated and the impact of compression was analyzed. Fiber bundles overlaying the micro structure were identified which affect the homogeneity of the gas flow. There are significant deviations between the impact of compression on effective material properties for this type of gas diffusion layers and the Kozeny-Carman equation.

  8. Transport characteristics of n-ZnO/p-Si heterojunction as determined from temperature dependent current–voltage measurements

    Energy Technology Data Exchange (ETDEWEB)

    Djiokap, S.R. Tankio, E-mail: stive.tankiodjiokap@nmmu.ac.za; Urgessa, Z.N.; Mbulanga, C.M.; Venter, A.; Botha, J.R.

    2016-01-01

    Zinc oxide (ZnO) nanorods have been synthesized by a two-step chemical bath deposition process on silicon substrates having different dopant densities and orientations. Scanning electron microscopy and X-ray diffraction analysis reveal that the orientation of the Si substrate does not affect the orientation, distribution or crystallinity of the nanostructures. The electrical properties of the ZnO/Si heterojunction are also investigated by current–voltage (I–V) measurements. The ideality factor is found to be 2.6 at 295 K, indicating that complex current transport mechanisms are at play. Temperature dependent I–V characteristics have been used to determine the dominant transport mechanism. The experimental results suggest that in the low bias region the current is dominated by a trap assisted multi-step tunneling process.

  9. Transport characteristics of n-ZnO/p-Si heterojunction as determined from temperature dependent current-voltage measurements

    Science.gov (United States)

    Djiokap, S. R. Tankio; Urgessa, Z. N.; Mbulanga, C. M.; Venter, A.; Botha, J. R.

    2016-01-01

    Zinc oxide (ZnO) nanorods have been synthesized by a two-step chemical bath deposition process on silicon substrates having different dopant densities and orientations. Scanning electron microscopy and X-ray diffraction analysis reveal that the orientation of the Si substrate does not affect the orientation, distribution or crystallinity of the nanostructures. The electrical properties of the ZnO/Si heterojunction are also investigated by current-voltage (I-V) measurements. The ideality factor is found to be 2.6 at 295 K, indicating that complex current transport mechanisms are at play. Temperature dependent I-V characteristics have been used to determine the dominant transport mechanism. The experimental results suggest that in the low bias region the current is dominated by a trap assisted multi-step tunneling process.

  10. Types and analysis of defects in welding junctions of the header to steam generator shells on power-generating units with VVER-1000

    Science.gov (United States)

    Ozhigov, L. S.; Voevodin, V. N.; Mitrofanov, A. S.; Vasilenko, R. L.

    2016-10-01

    Investigation objects were metal templates, which were cut during the repair of welding junction no. 111 (header to the steam generator shell) on a power-generating unit with VVER-1000 of the South-Ukraine NPP, and substances of mud depositions collected from walls of this junction. Investigations were carried out using metallography, optical microscopy, and scanning electron microscopy with energy dispersion microanalysis by an MMO-1600-AT metallurgical microscope and a JEOL JSM-7001F scanning electron microscope with the Shottky cathode. As a result of investigations in corrosion pits and mud depositions in the area of welding junction no. 111, iron and copper-enriched particles were revealed. It is shown that, when contacting with the steel header surface, these particles can form microgalvanic cells causing reactions of iron dissolution and the pit corrosion of metal. Nearby corrosion pits in metal are microcracks, which can be effect of the stress state of metal under corrosion pits along with revealed effects of twinning. The hypothesis is expressed that pitting corrosion of metal occurred during the first operation period of the power-generating unit in the ammonia water chemistry conditions (WCC). The formation of corrosion pits and nucleating cracks from them was stopped with the further operation under morpholine WCC. The absence of macrocracks in metal of templates verifies that, during operation, welding junction no. 111 operated under load conditions not exceeding the permissible ones by design requirements. The durability of the welding junction of the header to the steam generator shell significantly depends on the technological schedule of chemical cleaning and steam generator shut-down cooling.

  11. Aerobic scope and cardiovascular oxygen transport is not compromised at high temperatures in the toad Rhinella marina.

    Science.gov (United States)

    Overgaard, Johannes; Andersen, Jonas L; Findsen, Anders; Pedersen, Pil B M; Hansen, Kasper; Ozolina, Karlina; Wang, Tobias

    2012-10-15

    Numerous recent studies convincingly correlate the upper thermal tolerance limit of aquatic ectothermic animals to reduced aerobic scope, and ascribe the decline in aerobic scope to failure of the cardiovascular system at high temperatures. In the present study we investigate whether this 'aerobic scope model' applies to an air-breathing and semi-terrestrial vertebrate Rhinella marina (formerly Bufo marinus). To quantify aerobic scope, we measured resting and maximal rate of oxygen consumption at temperatures ranging from 10 to 40°C. To include potential effects of acclimation, three groups of toads were acclimated chronically at 20, 25 and 30°C, respectively. The absolute difference between resting and maximal rate of oxygen consumption increased progressively with temperature and there was no significant decrease in aerobic scope, even at temperature immediately below the lethal limit (41-42°C). Haematological and cardiorespiratory variables were measured at rest and immediately after maximal activity at benign (30°C) and critically high (40°C) temperatures. Within this temperature interval, both resting and active heart rate increased, and there was no indication of respiratory failure, judged from high arterial oxygen saturation, P(O2) and [Hb(O2)]. With the exception of elevated resting metabolic rate for cold-acclimated toads, we found few differences in the thermal responses between acclimation groups with regard to the cardiometabolic parameters. In conclusion, we found no evidence for temperature-induced cardiorespiratory failure in R. marina, indicating that maintenance of aerobic scope and oxygen transport is unrelated to the upper thermal limit of this air-breathing semi-terrestrial vertebrate.

  12. The physics of nanoelectronics transport and fluctuation phenomena at low temperatures

    CERN Document Server

    Heikkila, Tero T

    2013-01-01

    Advances in nanotechnology have allowed physicists and engineers to miniaturize electronic structures to the limit where finite-size related phenomena start to impact their properties. This book discusses such phenomena and models made for their description. The book starts from the semiclassical description of nonequilibrium effects, details the scattering theory used for quantum transport calculations, and explains the main interference effects. It also describes how to treat fluctuations and correlations, how interactions affect transport through small islands, and how superconductivity modifies these effects. The last two chapters describe new emerging fields related with graphene and nanoelectromechanics. The focus of the book is on the phenomena rather than formalism, but the book still explains in detail the main models constructed for these phenomena. It also introduces a number of electronic devices, including the single-electron transistor, the superconducting tunnel junction refrigerator, and the s...

  13. Modelling of neutron absorbers in high temperature reactors by combined transport diffusion methods

    OpenAIRE

    Fen, V.; Lebedev, M.; Sarytchev, V.; Scherer, W.

    1992-01-01

    Today, the neutron-physical description of strong neutron absorbing materials for control and shut-down of nuclear power plants is performed using combined transport and diffusion methods. Two of these approaches are described and compared in this paper. The method of equivalent cross-sections has been developed at the KFA-Jülich Institute for Safety Research and Reactor Technology (ISR) and was widely used for all german HTR reactor concepts. The Obninsk Institute for Nuclear Power Engineeri...

  14. Fully Relativistic Temperature-Dependent Electronic Transport Properties of Magnetic Alloys From the First Principles.

    Czech Academy of Sciences Publication Activity Database

    Wagenknecht, David; Carva, K.; Turek, Ilja

    2017-01-01

    Roč. 53, č. 11 (2017), č. článku 1700205. ISSN 0018-9464 R&D Projects: GA ČR GA15-13436S Institutional support: RVO:68081723 Keywords : electronic transport * magnetic alloys * ab initio theory Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.243, year: 2016

  15. Turbulent heat transport in two- and three-dimensional temperature fields

    Energy Technology Data Exchange (ETDEWEB)

    Samaraweera, Don Sarath Abesiri [Univ. of California, Berkeley, CA (United States)

    1978-03-01

    A fundamental numerical study of turbulent heat and mass transport processes in two- and three-dimensional convective flows is presented. The model of turbulence employed is the type referred to as a second-order closure. In this scheme transport equations for all nonzero components of the Reynolds stress tensor, for the isotropic dissipation rate of turbulent kinetic energy, for all nonzero scalar flux tensor components and for the mean square scalar fluctuations are solved by a finite difference method along with the mean momentum and mean enthalpy (or concentration) equations. The model used for the stresses was developed earlier. Parallel ideas were utilised in obtaining a model for turbulent heat and mass transfer processes. The study has focused especially on the problem of nonaxisymmetric convective heat and mass transport in pipes, which arises when the boundary conditions are not axisymmetric. The few available experimental data on such situations have indicated anisotropy in effective diffusivities. To expand the available data base an experiment was conducted to obtain heat transfer measurements in strong three-dimensional heating conditions. Numerical procedures especially suitable for incorporation of second-order turbulent closure models have been developed. The effect of circumferential conduction in the tube material, which is influential in the asymmetric heating data currently available, was accounted for directly by extending the finite difference calculations into the pipe wall. The principal goal of predicting three-dimensional scalar transfer has been achieved.

  16. (1)H-NMR and charge transport in metallic polypyrrole at ultra-low temperatures and high magnetic fields.

    Science.gov (United States)

    Jugeshwar Singh, K; Clark, W G; Ramesh, K P; Menon, Reghu

    2008-11-19

    The temperature dependence of conductivity, proton spin relaxation time (T(1)) and magnetoconductance (MC) in metallic polypyrrole (PPy) doped with PF(6)(-) have been carried out at mK temperatures and high magnetic fields. At T50 K-relaxation is due to the dipolar interaction modulated by the reorientation of the symmetric PF(6) groups following the Bloembergen, Purcell and Pound (BPP) model. The data analysis shows that the Korringa ratio is enhanced by an order of magnitude. The positive and negative MC at TmK is due to the contributions from weak localization and Coulomb-correlated hopping transport, respectively. The role of EEI is observed to be consistent in conductivity, T(1) and MC data, especially at T<1 K.

  17. Effects of Incubation Temperature and Transportation Stress on Yolk Utilization, Small Intestine Development, and Post-Hatch Performance of High-Yield Broiler Chicks

    OpenAIRE

    Barri, Adriana

    2008-01-01

    Growth and performance parameters of broiler chicks depend on adequate development of the small intestine. Stressors such as elevated or decreased temperatures during incubation and post-hatch transportation may have an effect on the gastrointestinal development of the broiler chick. The objective of the first study was to investigate the effects of elevated embryonic incubation temperature (IT) on post-hatch relative nutrient transporter gene expression, integrity of the intestinal epithel...

  18. Influence of temperature on oxygen permeation through ion transport membrane to feed a biomass gasifier

    Science.gov (United States)

    Antonini, T.; Foscolo, P. U.; Gallucci, K.; Stendardo, S.

    2015-11-01

    Oxygen-permeable perovskite membranes with mixed ionic-electronic conducting properties can play an important role in the high temperature separation of oxygen from air. A detailed design of a membrane test module is presented, useful to test mechanical resistance and structural stability of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) capillary membrane in the reactor environment. Preliminary experimental results of membrane permeation tests highlight the positive effect of temperature on perovskite materials. This behaviour is also confirmed by a computational model of char combustion with oxygen permeated through the membrane module, when it is placed inside a gasifier reactor to provide the necessary input of heat to the gasification endothermic process. The results show that the temperature affects the oxygen permeation of the BSCF membrane remarkably.

  19. Temperature-Dependent Polarization in Field-Effect Transport and Photovoltaic Measurements of Methylammonium Lead Iodide.

    Science.gov (United States)

    Labram, John G; Fabini, Douglas H; Perry, Erin E; Lehner, Anna J; Wang, Hengbin; Glaudell, Anne M; Wu, Guang; Evans, Hayden; Buck, David; Cotta, Robert; Echegoyen, Luis; Wudl, Fred; Seshadri, Ram; Chabinyc, Michael L

    2015-09-17

    While recent improvements in the reported peak power conversion efficiency (PCE) of hybrid organic-inorganic perovskite solar cells have been truly astonishing, there are many fundamental questions about the electronic behavior of these materials. Here we have studied a set of electronic devices employing methylammonium lead iodide ((MA)PbI3) as the active material and conducted a series of temperature-dependent measurements. Field-effect transistor, capacitor, and photovoltaic cell measurements all reveal behavior consistent with substantial and strongly temperature-dependent polarization susceptibility in (MA)PbI3 at temporal and spatial scales that significantly impact functional behavior. The relative PCE of (MA)PbI3 photovoltaic cells is observed to reduce drastically with decreasing temperature, suggesting that such polarization effects could be a prerequisite for high-performance device operation.

  20. Heat balance in the catalyst layer and the boundary condition for heat transport equation in a low-temperature fuel cell

    Science.gov (United States)

    Kulikovsky, A. A.

    We consider heat balance in the catalyst layer of a low-temperature fuel cell. Based on the heat transport equation in the layer, the exact boundary condition for the problem of heat transport in the cell is obtained. The limits of validity of the resulting expression are discussed.

  1. Transport properties of natural gas through polyethylene nanocomposites at high temperature and pressure

    DEFF Research Database (Denmark)

    Adewole, Jimoh K.; Jensen, Lars; Al-Mubaiyedh, Usamah A.

    2012-01-01

    High density polyethylene (HDPE)/clay nanocomposites containing nanoclay concentrations of 1, 2.5, and 5 wt% were prepared by a melt blending process. The effects of various types of nanoclays and their concentrations on permeability, solubility, and diffusivity of natural gas in the nanocomposites...... at constant temperature had little influence on the permeability, whereas increasing the temperature from 30 to 70 degrees C significantly increased the permeability of the gas. Additionally, the effect of crystallinity on permeability, solubility, and diffusivity was investigated. Thus, the permeability...

  2. Transport of temperature and humidity variance and covariance in the marine surface layer

    DEFF Research Database (Denmark)

    Sempreviva, A.M.; Højstrup, J.

    1998-01-01

    they have never been shown together in the literature. For this purpose an extensive set of humidity and temperature turbulence data from two heights in a marine environment has been analysed. We discuss and compare our results with results from earlier studies for a range of stability from near...

  3. Temperature dependent electrical transport characteristics of BaTiO3 modified lithium borate glasses

    Directory of Open Access Journals (Sweden)

    Vanita Thakur

    2015-08-01

    Full Text Available The glass samples with composition (70B2O3-29Li2O-1Dy2O3-xBT; x = 0, 10 and 20 weight percent, have been prepared by conventional melt quench technique. The dielectric measurements as a function of temperature have been carried out on these samples in the frequency range 1 Hz-10 MHz. The dielectric relaxation characteristics of these samples have been studied by analyzing dielectric spectroscopy, dielectric loss, electric modulus formulation and electrical conductivity spectroscopy. It is found that the dielectric permittivity of the samples increases with an increase in the temperature and BT content. The frequency dependent ac conductivity has been analyzed using Jonscher’s universal power law whereas non exponential KWW function has been invoked to fit the experimental data of the imaginary part of the electric modulus. The values of the activation energy determined from the electric modulus and that from dc conductivity have been found to be quite close to each other suggesting that the same type of charge barriers are involved in the relaxation and the conduction mechanisms. The stretched exponent (β and the power exponent (n have been found to be temperature and composition dependent. The decrease in n with an increase in temperature further suggested that the ac conduction mechanism of the studied samples follows the correlated barrier hopping (CBH model.

  4. Temperature dependency of virus and nanoparticle transport and retention in saturated porous media

    Science.gov (United States)

    The influence of temperature (4 and 20 °C) on virus and nanoparticle attachment in columns packed with quartz sand was studied under various physiochemical conditions. Fitted values of the attachment rate coefficient (katt) and the solid fraction that contributed to attachment (Sf) were found to be...

  5. Biosynthesis of intestinal microvillar proteins. Low temperature arrests both processing and intracellular transport

    DEFF Research Database (Denmark)

    Danielsen, E M; Hansen, Gert Helge; Cowell, G M

    1989-01-01

    The effect of culture at 20 degrees C on biosynthesis of microvillar enzymes was studied in pig small intestinal mucosal explants. At this temperature, aminopeptidase N (EC 3.4.11.2) and sucrase-isomaltase (EC 3.2.1.48-10) both accumulated intracellularly, predominantly in their transient, high m...

  6. Biosynthesis of intestinal microvillar proteins. Low temperature arrests both processing and intracellular transport

    DEFF Research Database (Denmark)

    Danielsen, E M; Hansen, Gert Helge; Cowell, G M

    1989-01-01

    The effect of culture at 20 degrees C on biosynthesis of microvillar enzymes was studied in pig small intestinal mucosal explants. At this temperature, aminopeptidase N (EC 3.4.11.2) and sucrase-isomaltase (EC 3.2.1.48-10) both accumulated intracellularly, predominantly in their transient, high...

  7. Finite-temperature charge transport in the one-dimensional Hubbard model

    NARCIS (Netherlands)

    Jin, F.; Steinigeweg, R.; Heidrich-Meisner, F.; Michielsen, K.; De Raedt, H.

    2015-01-01

    We study the charge conductivity of the one-dimensional repulsive Hubbard model at finite temperature using the method of dynamical quantum typicality, focusing at half filling. This numerical approach allows us to obtain current autocorrelation functions from systems with as many as 18 sites, way

  8. High-temperature stability of electron transport in semiconductors with strong spin-orbital interaction

    Science.gov (United States)

    Tomaka, G.; Grendysa, J.; ŚliŻ, P.; Becker, C. R.; Polit, J.; Wojnarowska, R.; Stadler, A.; Sheregii, E. M.

    2016-05-01

    Experimental results of the magnetotransport measurements (longitudinal magnetoresistance Rx x and the Hall resistance Rx y) are presented over a wide interval of temperatures for several samples of Hg1 -xCdxTe (x ≈0.13 -0.15 ) grown by MBE—thin layers (thickness about 100 nm) strained and not strained and thick ones with thickness about 1 μ m . An amazing temperature stability of the SdH-oscillation period and amplitude is observed in the entire temperature interval of measurements up to 50 K. Moreover, the quantum Hall effect (QHE) behavior of the Hall resistance is registered in the same temperature interval. These peculiarities of the Rx x and Rx y for strained thin layers are interpreted using quantum Hall conductivity (QHC) on topologically protected surface states (TPSS) [C. Brüne et al., Phys. Rev. Lett. 106, 126803 (2011), 10.1103/PhysRevLett.106.126803]. In the case of not strained layers it is assumed that the QHC on the TPSS (or on the resonant interface states) contributes also to the conductance of the bulk samples.

  9. Growth and Low Temperature Transport Measurements of Pure and Doped Bismuth Selenide

    DEFF Research Database (Denmark)

    Mlack, Jerome Thomas

    pressure vapor-solid growth. The growth method yields a variety of nanostructures, and materials analysis shows ordered structures of bismuth selenide in all cases. Low-temperature measurements of as-grown nanostructures indicate tunable carrier density in all samples. By doping the nanostructures...

  10. Study of point defects in non crystalline alloys by high temperature mass transport experiments

    International Nuclear Information System (INIS)

    Limoge, Y.

    1986-09-01

    We present in this communication the results of new experiments designed to study the mass transport mechanism in non-crystalline metallic alloys. They are based on the isothermal measurement of the crystallization kinetics, either without constraint or under electron irradiation or hydrostatic pressure. These experiments show that in the alloys studied, (FeNi) 8 (Pb) 2 and Ni 6 Nb 4 ), irradiation enhances the diffusion on the one hand, and on the other that there exist an activation volume for diffusion, of the order of one atomic volume. We discuss then the atomic model of diffusion needed to explain our results

  11. Temperature mapping of trucks transporting fertile eggs and day-old chicks: Efficiency and/or acclimatization?

    Directory of Open Access Journals (Sweden)

    Aérica C. Nazareno

    2015-02-01

    Full Text Available The aim of this study was to evaluate the thermal profiles of trucks used for transporting fertile eggs and day-old chicks. This study was carried out in a broiler hatchery in the State of Sao Paulo. The experiment was conducted during three months, in which six egg loads and 11 chick loads were observed. Thermal profile assessments were performed in an environmental controlled trucks with thermal control and following dimensions: 7.5 x 2.6 x 2.5 m for eggs, and 8.0 x 2.5 x 2.5 m for chicks. The maximum transport capacities were approximately of 592 boxes of eggs and 630 boxes of chicks, distributed all over the lorry. The thermal profiles were assessed at five-minutes-interval for eggs and in ten-minutes-interval for chicks, using thermal variables such as temperature, relative humidity and specific enthalpy. Geostatistics was used to model spatial dependency (by kriging. The results showed that the acclimatization in trucks was deficient. The loads were found to be submitted to an incompatible temperature, showing a huge thermal variety in the body trucks.

  12. temperature

    Directory of Open Access Journals (Sweden)

    G. Polt

    2015-10-01

    Full Text Available In-situ X-ray diffraction was applied to isotactic polypropylene with a high volume fraction of α-phase (α-iPP while it has been compressed at temperatures below and above its glass transition temperature Tg. The diffraction patterns were evaluated by the Multi-reflection X-ray Profile Analysis (MXPA method, revealing microstructural parameters such as the density of dislocations and the size of coherently scattering domains (CSD-size. A significant difference in the development of the dislocation density was found compared to compression at temperatures above Tg, pointing at a different plastic deformation mechanism at these temperatures. Based on the individual evolutions of the dislocation density and CSD-size observed as a function of compressive strain, suggestions for the deformation mechanisms occurring below and above Tg are made.

  13. The effects of temperature and motility on the advective transport of a deep subsurface bacteria through saturated sediment

    Energy Technology Data Exchange (ETDEWEB)

    McCaulou, Douglas Ray [Univ. of Arizona, Tucson, AZ (United States)

    1993-01-01

    Replicate column experiments were done to quantify the effects of temperature and bacterial motility on advective transport through repacked, but otherwise unaltered, natural aquifer sediment. The bacteria used in this study, A0500, was a flagellated, spore-forming rod isolated from the deep subsurface at DOE`s Savannah River Laboratory. Motility was controlled by turning on flagellar metabolism at 18°C but off at 40°α), estimated using a steady-state filtration model. The observed greater microsphere removal at the higher temperature agreed with the physical-chemical model, but bacteria removal at 18{degrees}C was only half that at 4°C. The sticking efficiency for non-motile A0500 (4°C) was over three times that of the motile A0500 (18°C), 0.073 versus 0.022 respectively. Analysis of complete breakthrough curves using a non-steady, kinetically limited, transport model to estimate the time scales of attachment and detachment suggested that motile A 0500 bacteria traveled twice as far as non-motile A 0500 bacteria before becoming attached. Once attached, non-motile colloids detached on the time scale of 9 to 17 days. The time scale for detachment of motile A0500 bacteria was shorter, 4 to 5 days. Results indicate that bacterial attachment was reversible and detachment was enhanced by bacterial motifity. The kinetic energy of bacterial motility changed the attachment-detachment kinetics in favor of the detached state. The chemical factors responsible for the enhanced transport are not known. However, motility may have caused weakly held bacteria to detach from the secondary minimum, and possibly from the primary minimum, as described by DLVO theory.

  14. Transported Low-Temperature Geothermal Energy for Thermal End Uses Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhiyao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gluesenkamp, Kyle R [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mehdizadeh Momen, Ayyoub [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Li, Jan-Mou [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    The use of geothermal energy is an emerging area for improving the nation’s energy resiliency. Conventionally, geothermal energy applications have focused on power generation using high temperature hydrothermal resources or enhanced geothermal systems. However, many low temperature (below 150°C/300°F) geothermal resources are also available but have not been fully utilized. For example, it is estimated that 25 billion barrels of geothermal fluid (mostly water and some dissolved solids) at 176°F to 302°F (80°C to 150°C) is coproduced annually at oil and gas wells in the United States (DOE 2015). The heat contained in coproduced geothermal fluid (also referred as “coproduced water”) is typically wasted because the fluid is reinjected back into the ground without extracting the heat.

  15. Superconductivity and low temperature electrical transport in B-doped CVD nanocrystalline diamond

    Directory of Open Access Journals (Sweden)

    Milos Nesladek, Jiri J. Mares, Dominique Tromson, Christine Mer, Philippe Bergonzo, Pavel Hubik and Jozef Kristofik

    2006-01-01

    Full Text Available In this work, we report on superconductivity (SC found in thin B-doped nanocrystalline diamond films, prepared by the PE-CVD technique. The thickness of the films varies from about 100 to 400 nm, the films are grown on low-alkaline glass at substrate temperatures of about 500–700 °C. The SIMS measurements show that films can be heavily doped with boron in concentrations in the range of 3×1021 cm−3. The Raman spectra show Fano resonances, confirming the substitutional B-incorporation. The low temperature magnetotransport measurements reveal a positive magnetoresistance. The SC transition is observed at about Tc=1.66 K. A simple theory exploiting the concept of weak localization accounting for this transition is proposed.

  16. Influence of the binder nature and the temperature on the chloride transport through cementitious materials

    International Nuclear Information System (INIS)

    Nguyen, Th.S.

    2006-09-01

    The objective of this work is to document the effect of the temperature on the chloride diffusion through cement-based materials. The chloride diffusion coefficient, the penetration profiles and the chloride interactions with the solid phase were highlighted. The materials were CEM I and CEM V/A mortars and pastes. They were cured in wet room (21 ± 2 C, 90% relative humidity) for 1 month in the case of CEM I and 3 months in the case of CEM V before the experiments started. The temperature levels were 5, 21, 35 and 80 C.In addition, microstructure analyses were carried on using X-rays diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The experimental results were then used to continue to develop the numerical code, MsDiff, developed in our research group. A good agreement between the numerical concentration profiles and the experimental ones was found. (author)

  17. Spectral functions in finite temperature SU(3) gauge theory and applications to transport phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Haas, Michael

    2014-12-10

    In this thesis, gluon spectral functions in SU(3) gauge theory are calculated at finite temperature. The temperature range covers the confining regime below T{sub c} to the high temperature regime, where perturbation theory is applicable. The numerical tool is the Maximum Entropy Method (MEM) employing euclidean, non-perturbative, Landau gauge gluon propagators, obtained with the Functional Renormalisation Group and Lattice QCD, as input. The spectral function is related to the propagators by an integral equation. MEM is a complex multidimensional optimisation algorithm to invert such integral equations, corresponding to an analytic continuation of the numerical data. A continuation of a discreet set of data cannot be unambiguous. The occuring ambiguities are resolved by introducing a priori knowledge of the asymptotic shape of the spectral function, in the form of a model function. Thereby, MEM simultaneously optimizes the spectral function to the input propagators and the model, leading to a unique model-dependent solution. Standard-MEM assumes positive definite spectral functions, whereas gluons show a violation of positivity in the spectral function, due to confinement. Therefore, an extended-MEM algorithm is proposed. The main application of this thesis is the calculation of the shear viscosity in units of the entropy density. A Kubo relation connects shear viscosity to the low frequency limit of a certain energy-momentum tensor correlation function. For this correlation function a loop representation of finite order in terms of gluon spectral functions is derived. That allows to calculate (η)/(s) from first principles in SU(3) for the first time for arbitrary temperatures. Further, a mapping of the SU(3) results for (η)/(s) to QCD is proposed.

  18. Highly efficient organic solar Cells based on a robust room-temperature solution-processed copper iodide hole transporter

    KAUST Repository

    Zhao, Kui

    2015-07-30

    Achieving high performance and reliable organic solar cells hinges on the development of stable and energetically suitable hole transporting buffer layers in tune with the electrode and photoactive materials of the solar cell stack. Here we have identified solution-processed copper(I) iodide (CuI) thin films with low-temperature processing conditions as an effective hole–transporting layer (HTL) for a wide range of polymer:fullerene bulk heterojunction (BHJ) systems. The solar cells using CuI HTL show higher power conversion efficiency (PCE) in standard device structure for polymer blends, up to PCE of 8.8%, as compared with poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL, for a broad range of polymer:fullerene systems. The CuI layer properties and solar cell device behavior are shown to be remarkably robust and insensitive to a wide range of processing conditions of the HTL, including processing solvent, annealing temperature (room temperature up to 200 °C), and film thickness. CuI is also shown to improve the overall lifetime of solar cells in the standard architecture as compared to PEDOT:PSS. We further demonstrate promising solar cell performance when using CuI as top HTL in an inverted device architecture. The observation of uncommon properties, such as photoconductivity of CuI and templating effects on the BHJ layer formation, are also discussed. This study points to CuI as being a good candidate to replace PEDOT:PSS in solution-processed solar cells thanks to the facile implementation and demonstrated robustness of CuI thin films.

  19. Optoelectronic devices, low temperature preparation methods, and improved electron transport layers

    KAUST Repository

    Eita, Mohamed S.

    2016-08-04

    An optoelectronic device such as a photovoltaic device which has at least one layer, such as an electron transport layer, which comprises a plurality of alternating, oppositely charged layers including metal oxide layers. The metal oxide can be zinc oxide. The plurality of layers can be prepared by layer-by-layer processing in which alternating layers are built up step-by-step due to electrostatic attraction. The efficiency of the device can be increased by this processing method compared to a comparable method like sputtering. The number of layers can be controlled to improve device efficiency. Aqueous solutions can be used which is environmentally friendly. Annealing can be avoided. A quantum dot layer can be used next to the metal oxide layer to form a quantum dot heterojunction solar device.

  20. Gas Transport Properties of PEBAX®/Room Temperature Ionic Liquid Gel Membranes

    Czech Academy of Sciences Publication Activity Database

    Bernardo, P.; Jansen, J. C.; Bazzarelli, F.; Tasselli, F.; Fuoco, A.; Friess, K.; Izák, Pavel; Jarmarová, Veronika; Kačírková, Marie; Clarizia, G.

    2012-01-01

    Roč. 97, SI (2012), s. 73-82 ISSN 1383-5866. [Conference on Ionic Liquids in Separation and Purification Technology (ILSEPT) /1./. Sitges, 04.09.2011-07.09.2011] R&D Projects: GA ČR GAP106/10/1194 Grant - others:RFCS(XE) RFCR-CT-2010-00009 Institutional support: RVO:67985858 Keywords : room temperature ionic liquid * ionic liquid * polymer gel Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.894, year: 2012

  1. Comparative High Field Magneto-transport Of Rare Earth Oxypnictides With Maximum Transition Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Balakirev, Fedor F [Los Alamos National Laboratory; Migliori, A [MPA-NHMFL; Riggs, S [NHMFL-FSU; Hunte, F [NHMFL-FSU; Gurevich, A [NHMFL-FSU; Larbalestier, D [NHMFL-FSU; Boebinger, G [NHMFL-FSU; Jaroszynski, J [NHMFL-FSU; Ren, Z [CHINA; Lu, W [CHINA; Yang, J [CHINA; Shen, X [CHINA; Dong, X [CHINA; Zhao, Z [CHINA; Jin, R [ORNL; Sefat, A [ORNL; Mcguire, M [ORNL; Sales, B [ORNL; Christen, D [ORNL; Mandrus, D [ORNL

    2008-01-01

    We compare magnetotransport of the three iron-arsenide-based compounds ReFeAsO (Re=La, Sm, Nd) in very high DC and pulsed magnetic fields up to 45 and 54 T, respectively. Each sample studied exhibits a superconducting transition temperature near the maximum reported to date for that particular compound. While high magnetic fields do not suppress the superconducting state appreciably, the resistivity, Hall coefficient, and critical magnetic fields, taken together, suggest that the phenomenology and superconducting parameters of the oxypnictide superconductors bridges the gap between MgB{sub 2} and YBCO.

  2. Low-Temperature Modification of ZnO Nanoparticles Film for Electron-Transport Layers in Perovskite Solar Cells.

    Science.gov (United States)

    Han, Gill Sang; Shim, Hyun-Woo; Lee, Seongha; Duff, Matthew L; Lee, Jung-Kun

    2017-06-09

    An electron-transport layer (ETL) that selectively collects photogenerated electrons is an important constituent of halide perovskite solar cells (PSCs). Although TiO 2 films are widely used as ETL of PSCs, the processing of TiO 2 films with high electron mobility requires high-temperature annealing and TiO 2 dissociates the perovskite layer through a photocatalytic reaction. Here, we report an effective surface-modification method of a room-temperature processed ZnO nanoparticles (NPs) layer as an alternative to the TiO 2 ETL. A combination of simple UV exposure and nitric acid treatment effectively removes the hydroxyl group and passivates surface defects in ZnO NPs. The surface modification of ZnO NPs increases the power conversion efficiency (PCE) of PSCs to 14 % and decreases the aging of PSCs under light soaking. These results suggest that the surface-modified ZnO film can be a good ETL of PSCs and provide a path toward low-temperature processing of efficient and stable PSCs that are compatible with flexible electronics. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Non-equilibrium temperatures and heat transport in nanosystems with defects, described by a tensorial internal variable

    Directory of Open Access Journals (Sweden)

    Restuccia Liliana

    2016-06-01

    Full Text Available The paper deals with the meaning of non-equilibrium temperatures in nanosystems with an internal variable, describing defects inside them, and implications on heat transport. In equilibrium all definitions of temperature lead to the same value, but in nonequilibrium steady states they lead to different values, giving information on different degrees of freedom. We discuss the caloric and entropic non-equilibrium temperatures and the relations among them, in defective nanosystems (crystals with dislocations or porous channels, carbon nanotubes in a solid matrix and so on, crossed by an external energy flux. Here, we present a model for nanocrystals with dislocation defects submitted to an external energy flux. The dislocations may have a strong influence on the effective thermal conductivity, and their own dynamics may be coupled in relevant way to the heat flux dynamics. In the linear case the constitutive relations, the rate equations for the internal variable and the heat flux are worked out and a generalized telegraphic heat equation is derived in the anisotropic and isotropic case, describing the thermal disturbances with finite velocity.

  4. Evaluation of stability of allergen extracts for sublingual immunotherapy during transport under unfavourable temperature conditions with an innovative thermal insulating packaging.

    Science.gov (United States)

    Puccinelli, P; Natoli, V; Dell'albani, I; Scurati, S; Incorvaia, C; Barbieri, S; Masieri, S; Frati, F

    2013-10-01

    Many pharmaceutical and biotechnological products are temperature-sensitive and should normally be kept at a controlled temperature, particularly during transport, in order to prevent the loss of their stability and activity. Therefore, stability studies should be performed for temperature-sensitive products, considering product characteristics, typical environmental conditions, and anticipating environmental extremes that may occur during product transport in a specific country. Staloral products for sublingual immunotherapy are temperature sensitive and are labelled for maintenance under refrigerated conditions (2-8°C). Given the peculiar climatic context of Italy and the great temperature fluctuations that may occur during transport, this study was aimed at evaluating the impact of a new engineered thermal insulating packaging for Staloral. In particular, the purpose was to assess whether the new packaging could create a container condition able to preserve the stability and immunological activity of the product during the transport phase throughout Italy. The results showed that the range of temperatures that can affect the product, in the area surrounding the product packaging, may reach a peak of 63°C during transport under the most unfavourable climatic conditions, i.e. in a non-refrigerated van during the summer season, from the site of production in France to the patient's house in Catania, the city with the highest temperatures in Italy. However, the highest temperature reached inside the vaccine did not exceed 45°C over a period of about 2 h. The ELISA inhibition test on samples subjected to the extreme temperature conditions previously defined (45°C) showed an immunological activity higher than 75% of that initially measured and was comparable to those obtained with samples stored at controlled temperature (5°C). This means that, even in the worst case scenario, the structure of the allergen extracts is not influenced and the vaccine potency is

  5. Response of the global surface ozone distribution to Northern Hemisphere sea surface temperature changes: implications for long-range transport

    Science.gov (United States)

    Yi, Kan; Liu, Junfeng; Ban-Weiss, George; Zhang, Jiachen; Tao, Wei; Cheng, Yanli; Tao, Shu

    2017-07-01

    The response of surface ozone (O3) concentrations to basin-scale warming and cooling of Northern Hemisphere oceans is investigated using the Community Earth System Model (CESM). Idealized, spatially uniform sea surface temperature (SST) anomalies of ±1 °C are individually superimposed onto the North Pacific, North Atlantic, and North Indian oceans. Our simulations suggest large seasonal and regional variability in surface O3 in response to SST anomalies, especially in the boreal summer. The responses of surface O3 associated with basin-scale SST warming and cooling have similar magnitude but are opposite in sign. Increasing the SST by 1 °C in one of the oceans generally decreases the surface O3 concentrations from 1 to 5 ppbv. With fixed emissions, SST increases in a specific ocean basin in the Northern Hemisphere tend to increase the summertime surface O3 concentrations over upwind regions, accompanied by a widespread reduction over downwind continents. We implement the integrated process rate (IPR) analysis in CESM and find that meteorological O3 transport in response to SST changes is the key process causing surface O3 perturbations in most cases. During the boreal summer, basin-scale SST warming facilitates the vertical transport of O3 to the surface over upwind regions while significantly reducing the vertical transport over downwind continents. This process, as confirmed by tagged CO-like tracers, indicates a considerable suppression of intercontinental O3 transport due to increased tropospheric stability at lower midlatitudes induced by SST changes. Conversely, the responses of chemical O3 production to regional SST warming can exert positive effects on surface O3 levels over highly polluted continents, except South Asia, where intensified cloud loading in response to North Indian SST warming depresses both the surface air temperature and solar radiation, and thus photochemical O3 production. Our findings indicate a robust linkage between basin-scale SST

  6. Response of the global surface ozone distribution to Northern Hemisphere sea surface temperature changes: implications for long-range transport

    Directory of Open Access Journals (Sweden)

    K. Yi

    2017-07-01

    Full Text Available The response of surface ozone (O3 concentrations to basin-scale warming and cooling of Northern Hemisphere oceans is investigated using the Community Earth System Model (CESM. Idealized, spatially uniform sea surface temperature (SST anomalies of ±1 °C are individually superimposed onto the North Pacific, North Atlantic, and North Indian oceans. Our simulations suggest large seasonal and regional variability in surface O3 in response to SST anomalies, especially in the boreal summer. The responses of surface O3 associated with basin-scale SST warming and cooling have similar magnitude but are opposite in sign. Increasing the SST by 1 °C in one of the oceans generally decreases the surface O3 concentrations from 1 to 5 ppbv. With fixed emissions, SST increases in a specific ocean basin in the Northern Hemisphere tend to increase the summertime surface O3 concentrations over upwind regions, accompanied by a widespread reduction over downwind continents. We implement the integrated process rate (IPR analysis in CESM and find that meteorological O3 transport in response to SST changes is the key process causing surface O3 perturbations in most cases. During the boreal summer, basin-scale SST warming facilitates the vertical transport of O3 to the surface over upwind regions while significantly reducing the vertical transport over downwind continents. This process, as confirmed by tagged CO-like tracers, indicates a considerable suppression of intercontinental O3 transport due to increased tropospheric stability at lower midlatitudes induced by SST changes. Conversely, the responses of chemical O3 production to regional SST warming can exert positive effects on surface O3 levels over highly polluted continents, except South Asia, where intensified cloud loading in response to North Indian SST warming depresses both the surface air temperature and solar radiation, and thus photochemical O3 production. Our findings indicate a robust linkage

  7. Effect of rotational speed modulation on heat transport in a fluid layer with temperature dependent viscosity and internal heat source

    Directory of Open Access Journals (Sweden)

    B.S. Bhadauria

    2014-12-01

    Full Text Available In this paper, a theoretical investigation has been carried out to study the combined effect of rotation speed modulation and internal heating on thermal instability in a temperature dependent viscous horizontal fluid layer. Rayleigh–Bénard momentum equation with Coriolis term has been considered to describe the convective flow. The system is rotating about it is own axis with non-uniform rotational speed. In particular, a time-periodic and sinusoidally varying rotational speed has been considered. A weak nonlinear stability analysis is performed to find the effect of modulation on heat transport. Nusselt number is obtained in terms of amplitude of convection and internal Rayleigh number, and depicted graphically for showing the effects of various parameters of the system. The effect of modulated rotation speed is found to have a stabilizing effect for different values of modulation frequency. Further, internal heating and thermo-rheological parameters are found to destabilize the system.

  8. Thermally Stable Mesoporous Perovskite Solar Cells Incorporating Low-Temperature Processed Graphene/Polymer Electron Transporting Layer.

    Science.gov (United States)

    Tong, Shi Wun; Balapanuru, Janardhan; Fu, Deyi; Loh, Kian Ping

    2016-11-02

    In the short time since its discovery, perovskite solar cells (PSCs) have attained high power conversion efficiency but their lack of thermal stability remains a barrier to commercialization. Among the experimentally accessible parameter spaces for optimizing performance, identifying an electron transport layer (ETL) that forms a thermally stable interface with perovskite and which is solution-processable at low-temperature will certainly be advantageous. Herein, we developed a mesoporous graphene/polymer composite with these advantages when used as ETL in CH 3 NH 3 PbI 3 PSCs, and a high efficiency of 13.8% under AM 1.5G solar illumination could be obtained. Due to the high heat transmission coefficient and low isoelectric point of mesoporous graphene-based ETL, the PSC device enjoys good chemical and thermal stability. Our work demonstrates that the mesoporous graphene-based scaffold is a promising ETL candidate for high performance and thermally stable PSCs.

  9. Dynamical renormalization group approach to transport in ultrarelativistic plasmas: The electrical conductivity in high temperature QED

    International Nuclear Information System (INIS)

    Boyanovsky, Daniel; Vega, Hector J. de; Wang Shangyung

    2003-01-01

    The dc electrical conductivity of an ultrarelativistic QED plasma is studied in real time by implementing the dynamical renormalization group. The conductivity is obtained from the real-time dependence of a dissipative kernel closely related to the retarded photon polarization. Pinch singularities in the imaginary part of the polarization are manifest as secular terms that grow in time in the perturbative expansion of this kernel. The leading secular terms are studied explicitly and it is shown that they are insensitive to the anomalous damping of hard fermions as a result of a cancellation between self-energy and vertex corrections. The resummation of the secular terms via the dynamical renormalization group leads directly to a renormalization group equation in real time, which is the Boltzmann equation for the (gauge invariant) fermion distribution function. A direct correspondence between the perturbative expansion and the linearized Boltzmann equation is established, allowing a direct identification of the self-energy and vertex contributions to the collision term. We obtain a Fokker-Planck equation in momentum space that describes the dynamics of the departure from equilibrium to leading logarithmic order in the coupling. This equation determines that the transport time scale is given by t tr =24 π/e 4 T ln(1/e). The solution of the Fokker-Planck equation approaches asymptotically the steady-state solution as ∼e -t/(4.038...t tr ) . The steady-state solution leads to the conductivity σ=15.698 T/e 2 ln(1/e) to leading logarithmic order. We discuss the contributions beyond leading logarithms as well as beyond the Boltzmann equation. The dynamical renormalization group provides a link between linear response in quantum field theory and kinetic theory

  10. 'Anomalous electron transport' with 'Giant Current Density' at room temperature observed with nanogranular materials

    International Nuclear Information System (INIS)

    Koops, Hans W.P.

    2013-01-01

    Focused electron beam induced deposition is a novel bottom up nano-structurization technology. An electron beam of high power density is used to generate nano- structures with dimensions > 20 nm, but being composed from amorphous or nanogranular materials with crystals of 2 to 5 nm diameter embedded in a Fullerene matrix. Those compounds are generated in general by secondary or low energy electrons in layers of inorganic, organic, organometallic compounds absorbed to the sample. Those are converted into nanogranular materials by the electron beam following chemical and physical laws, as given by 'Mother Nature'. Metals and amorphous mixtures of chemical compounds from metals are normal resistors, which can carry a current density J 2 . Nanogranular composites like Au/C or Pt/C with metal nanocrystals embedded in a Fullerene matrix have hopping conduction with 0-dimensional Eigen-value characteristics and show 'anomalous electron transport' and can carry 'Giant Current Densities' with values from > 1 MA/cm 2 to 0.1 GA/cm 2 without destruction of the materials. However the area connecting the nanogranular material with a metal with a 3-dimensional electron gas needs to be designed, that the flowing current is reduced to the current density values which the 3-D metal can support without segregation. The basis for a theoretical explanation of the phenomenon can be geometry quantization for Coulomb blockade, of electron surface orbitals around the nanocrystals, hopping conduction, and the limitation of the density of states for phonons in geometry confined non percolated granular materials with strong difference in mass and orientation. Several applications in electronics, signal generators, light sources, detectors, and solar energy harvesting are suggested. (author)

  11. Reactions and mass transport in high temperature co-electrolysis of steam/CO2 mixtures for syngas production

    Science.gov (United States)

    Kim, Si-Won; Kim, Hyoungchul; Yoon, Kyung Joong; Lee, Jong-Ho; Kim, Byung-Kook; Choi, Wonjoon; Lee, Jong-Heun; Hong, Jongsup

    2015-04-01

    High temperature co-electrolysis of steam/CO2 mixtures using solid oxide cells has been proposed as a promising technology to mitigate climate change and power fluctuation of renewable energy. To make it viable, it is essential to control the complex reacting environment in their fuel electrode. In this study, dominant reaction pathway and species transport taking place in the fuel electrode and their effect on the cell performance are elucidated. Results show that steam is a primary reactant in electrolysis, and CO2 contributes to the electrochemical performance subsequently in addition to the effect of steam. CO2 reduction is predominantly governed by thermochemical reactions, whose influence to the electrochemical performance is evident near limiting currents. Chemical kinetics and mass transport play a significant role in co-electrolysis, given that the reduction reactions and diffusion of steam/CO2 mixtures are slow. The characteristic time scales determined by the kinetics, diffusion and materials dictate the cell performance and product compositions. The fuel electrode design should account for microstructure and catalysts for steam electrolysis and thermochemical CO2 reduction in order to optimize syngas production and store electrical energy effectively and efficiently. Syngas yield and selectivity are discussed, showing that they are substantially influenced by operating conditions, fuel electrode materials and its microstructure.

  12. Anomalous ion thermal transport in hot ion plasmas by the ion temperature gradient mode

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.Y.; Horton, W. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies); Coppi, B. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Research Lab. of Electronics)

    1992-01-01

    Experiments show that the observed radial profiles of the ion thermal conductivity {chi}{sub i} have the opposite shapes with those obtained from the ion temperature gradient mode ({eta}{sub i} mode) turbulence model by the traditional mixing length estimate. In this work, this radial profile problem is reconsidered with an electromagnetic study of the linear stability of the toroidal {eta}{sub i} mode and a new rule for choosing the mixing length. It is first shown that the electromagnetic effect gives a significant stabilizing effect on the toroidal {eta}{sub i} mode, and that the observed reduction of {chi}{sub i}(r) in the core region can be explained by this electromagnetic effect. Secondly, in view of earlier numerical simulations showing the transfer of fluctuation energy to larger scales that those for the fastest growth rate, as well as fluctuation measurements indicating longer radial correlation lengths, a new mixing length formula is proposed to explain the radial increase of the {chi}{sub i}. It is shown the new formula fits well the observed {chi}{sub i}(r) profiles in two TFTR supershot discharges and also gives the scaling law in the current and the magnetic field which agrees better with experiment than the conventional formula.

  13. Anomalous ion thermal transport in hot ion plasmas by the ion temperature gradient mode

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.Y.; Horton, W. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Coppi, B. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Research Lab. of Electronics

    1992-08-01

    Experiments show that the observed radial profiles of the ion thermal conductivity {chi}{sub i} have the opposite shapes with those obtained from the ion temperature gradient mode ({eta}{sub i} mode) turbulence model by the traditional mixing length estimate. In this work, this radial profile problem is reconsidered with an electromagnetic study of the linear stability of the toroidal {eta}{sub i} mode and a new rule for choosing the mixing length. It is first shown that the electromagnetic effect gives a significant stabilizing effect on the toroidal {eta}{sub i} mode, and that the observed reduction of {chi}{sub i}(r) in the core region can be explained by this electromagnetic effect. Secondly, in view of earlier numerical simulations showing the transfer of fluctuation energy to larger scales that those for the fastest growth rate, as well as fluctuation measurements indicating longer radial correlation lengths, a new mixing length formula is proposed to explain the radial increase of the {chi}{sub i}. It is shown the new formula fits well the observed {chi}{sub i}(r) profiles in two TFTR supershot discharges and also gives the scaling law in the current and the magnetic field which agrees better with experiment than the conventional formula.

  14. Anomalous ion thermal transport in hot ion plasmas by the ion temperature gradient mode

    International Nuclear Information System (INIS)

    Kim, J.Y.; Horton, W.; Coppi, B.

    1992-01-01

    Experiments show that the observed radial profiles of the ion thermal conductivity χ i have the opposite shapes with those obtained from the ion temperature gradient mode (η i mode) turbulence model by the traditional mixing length estimate. In this work, this radial profile problem is reconsidered with an electromagnetic study of the linear stability of the toroidal η i mode and a new rule for choosing the mixing length. It is first shown that the electromagnetic effect gives a significant stabilizing effect on the toroidal η i mode, and that the observed reduction of χ i (r) in the core region can be explained by this electromagnetic effect. Secondly, in view of earlier numerical simulations showing the transfer of fluctuation energy to larger scales that those for the fastest growth rate, as well as fluctuation measurements indicating longer radial correlation lengths, a new mixing length formula is proposed to explain the radial increase of the χ i . It is shown the new formula fits well the observed χ i (r) profiles in two TFTR supershot discharges and also gives the scaling law in the current and the magnetic field which agrees better with experiment than the conventional formula

  15. High field electron-spin transport and observation of the Dyakonov-Perel spin relaxation of drifting electrons in low temperature-grown gallium arsenide

    International Nuclear Information System (INIS)

    Miah, M. Idrish

    2008-01-01

    High field electron-spin transport in low temperature-grown gallium arsenide is studied. We generate electron spins in the samples by optical pumping. During transport, we observe the Dyakonov-Perel (DP) [M.I. Dyakonov, V.I. Perel, Zh. Eksp. Teor. Fiz. 60 (1971) 1954] spin relaxation of the drifting electrons. The results are discussed and are compared with those obtained in calculations of the DP spin relaxation frequency of the hot electrons. A good agreement is obtained

  16. High field electron-spin transport and observation of the Dyakonov-Perel spin relaxation of drifting electrons in low temperature-grown gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M. Idrish [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong-4331 (Bangladesh)], E-mail: m.miah@griffith.edu.au

    2008-11-17

    High field electron-spin transport in low temperature-grown gallium arsenide is studied. We generate electron spins in the samples by optical pumping. During transport, we observe the Dyakonov-Perel (DP) [M.I. Dyakonov, V.I. Perel, Zh. Eksp. Teor. Fiz. 60 (1971) 1954] spin relaxation of the drifting electrons. The results are discussed and are compared with those obtained in calculations of the DP spin relaxation frequency of the hot electrons. A good agreement is obtained.

  17. The Effect of Post-Baking Temperature and Thickness of ZnO Electron Transport Layers for Efficient Planar Heterojunction Organometal-Trihalide Perovskite Solar Cells

    OpenAIRE

    Kun-Mu Lee; Chuan-Jung Lin; Yin-Hsuan Chang; Ting-Han Lin; Vembu Suryanarayanan; Ming-Chung Wu

    2017-01-01

    Solution-processed zinc oxide (ZnO)-based planar heterojunction perovskite photovoltaic device is reported in this study. The photovoltaic device benefits from the ZnO film as a high-conductivity and high-transparent electron transport layer. The optimal electron transport layer thickness and post-baking temperature for ZnO are systematically studied by scanning electron microscopy, photoluminescence and time-resolved photoluminescence spectroscopy, and X-ray diffraction. Optimized perovskite...

  18. Temperature and frequency dependence of transport phenomena in co-doped rare earth oxides nanoparticles for ITSOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, A. [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Park Road, Islamabad 44000 (Pakistan); School of Science and Technology, University of Management and Technology, Sialkot Campus, Shahabpura Road, Sialkot 51310 (Pakistan); Saleemi, A.S. [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Park Road, Islamabad 44000 (Pakistan); Anis-ur-Rehman, M., E-mail: marehman@comsats.edu.pk [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Park Road, Islamabad 44000 (Pakistan)

    2015-05-25

    Highlights: • Phase pure ceria (Gd–La and Gd–Nd co-doped) as electrolytes for fuel cells. • Facile synthesis is done with composite mediated hydrothermal method. • Significant variation in transport properties with doping concentration is observed. • The Raman spectra confirmed the targeted doping and increase of vacancy sites. • Maximum conductivity achieved was 1.78 S cm{sup −1} for Ce{sub 0.5}Gd{sub 0.25}Nd{sub 0.25}O{sub δ} at 600 °C. - Abstract: The present study is focused on the conductivity enhancement of the doped ceria. Composite mediated hydrothermal method (CMHM) was employed to produce the material. X-ray diffraction was used to determine phase of nanocrystalline Ce{sub 1−2x}Gd{sub x}La{sub x}O{sub δ} and Ce{sub 1−2x}Gd{sub x}Nd{sub x}O{sub δ} (x = 0.1, 0.25). Conduction mechanism (dc conductivity and ac conductivity) in prepared samples was observed as a function of temperature and frequency. DC conductivity was measured in temperature range 300–700 °C. AC conductivity was measured in frequency range 1 kHz to 3 MHz at temperatures 300, 400, 500, 600, and 700 °C. The enhancement in conductivity was observed due to availability of oxygen vacancy sites which was dependent on composition. The Raman measurements supported the electrical conductivity results and more vacancy sites were observed in Raman spectrum in samples which showed maximum conductivities. The maximum conductivity achieved was 1.78 S cm{sup −1} (at 600 °C) for Ce{sub 0.5}Gd{sub 0.25}Nd{sub 0.25}O{sub δ}, which is quite a higher value in these compounds. This made this material a potential candidate for its use as an electrolyte material for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs)

  19. Integrating distributed temperature sensing and geological characterization to quantify spatiotemporal variability in subsurface heat transport within the Critical Zone

    Science.gov (United States)

    Lin, Y. F. F.; Stumpf, A.; Luo, Y.; Kumar, P.

    2015-12-01

    data show that the temperature variations in amplitudes and trends are correlated with previous characterizations of the geology and hydrogeological properties. Through continuous collection of data, we hope to understand how subsurface heat transport is correlated with climate change and agricultural practices on a larger temporal scale.

  20. Coherent quantum transport in disordered systems: II. Temperature dependence of carrier diffusion coefficients from the time-dependent wavepacket diffusion method

    International Nuclear Information System (INIS)

    Zhong, Xinxin; Zhao, Yi; Cao, Jianshu

    2014-01-01

    The time-dependent wavepacket diffusion method for carrier quantum dynamics (Zhong and Zhao 2013 J. Chem. Phys. 138 014111), a truncated version of the stochastic Schrödinger equation/wavefunction approach that approximately satisfies the detailed balance principle and scales well with the size of the system, is applied to investigate the carrier transport in one-dimensional systems including both the static and dynamic disorders on site energies. The predicted diffusion coefficients with respect to temperature successfully bridge from band-like to hopping-type transport. As demonstrated in paper I (Moix et al 2013 New J. Phys. 15 085010), the static disorder tends to localize the carrier, whereas the dynamic disorder induces carrier dynamics. For the weak dynamic disorder, the diffusion coefficients are temperature-independent (band-like property) at low temperatures, which is consistent with the prediction from the Redfield equation, and a linear dependence of the coefficient on temperature (hopping-type property) only appears at high temperatures. In the intermediate regime of dynamic disorder, the transition from band-like to hopping-type transport can be easily observed at relatively low temperatures as the static disorder increases. When the dynamic disorder becomes strong, the carrier motion can follow the hopping-type mechanism even without static disorder. Furthermore, it is found that the memory time of dynamic disorder is an important factor in controlling the transition from the band-like to hopping-type motions. (paper)

  1. Inverted Organic Solar Cells with Low-Temperature Al-Doped-ZnO Electron Transport Layer Processed from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Qianni Zhang

    2018-01-01

    Full Text Available The aqueous-based Zn-ammine complex solutions represent one of the most promising routes to obtain the ZnO electron transport layer (ETL at a low temperature in inverted organic solar cells (OSCs. However, to dope the ZnO film processed from the Zn-ammine complex solutions is difficult since the introduction of metal ions into the Zn-ammine complex is a nontrivial process as ammonium hydroxide tends to precipitate metal salts due to acid-base neutralization reactions. In this paper, we investigate the inverted OSCs with Al-doped-ZnO ETL made by immersion of metallic Al into the Zn-ammine precursor solution. The effects of ZnO layer with different immersion time of Al on film properties and solar cell performance have been studied. The results show that, with the Al-doped-ZnO ETL, an improvement of the device performance could be obtained compared with the device with the un-doped ZnO ETL. The improved device performance is attributed to the enhancement of charge carrier mobility leading to a decreased charge carrier recombination and improved charge collection efficiency. The fabricated thin film transistors with the same ZnO or AZO films confirm the improved electrical characteristics of the Al doped ZnO film.

  2. Low-temperature thermal reduction of graphene oxide: In situ correlative structural, thermal desorption, and electrical transport measurements

    Science.gov (United States)

    Lipatov, Alexey; Guinel, Maxime J.-F.; Muratov, Dmitry S.; Vanyushin, Vladislav O.; Wilson, Peter M.; Kolmakov, Andrei; Sinitskii, Alexander

    2018-01-01

    Elucidation of the structural transformations in graphene oxide (GO) upon reduction remains an active and important area of research. We report the results of in situ heating experiments, during which electrical, mass spectrometry, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM) measurements were carried out correlatively. The simultaneous electrical and temperature programmed desorption measurements allowed us to correlate the onset of the increase in the electrical conductivity of GO by five orders of magnitude at about 150 °C with the maxima of the rates of desorption of H2O, CO, and CO2. Interestingly, this large conductivity change happens at an intermediate level of the reduction of GO, which likely corresponds to the point when the graphitic domains become large enough to enable percolative electronic transport. We demonstrate that the gas desorption is intimately related to (i) the changes in the chemical structure of GO detected by XPS and Raman spectroscopy and (ii) the formation of nanoscopic holes in GO sheets revealed by TEM. These in situ observations provide a better understanding of the mechanism of the GO thermal reduction.

  3. Computational method to predict thermodynamic, transport, and flow properties for the modified Langley 8-foot high-temperature tunnel

    Science.gov (United States)

    Venkateswaran, S.; Hunt, L. Roane; Prabhu, Ramadas K.

    1992-01-01

    The Langley 8 foot high temperature tunnel (8 ft HTT) is used to test components of hypersonic vehicles for aerothermal loads definition and structural component verification. The test medium of the 8 ft HTT is obtained by burning a mixture of methane and air under high pressure; the combustion products are expanded through an axisymmetric conical contoured nozzle to simulate atmospheric flight at Mach 7. This facility was modified to raise the oxygen content of the test medium to match that of air and to include Mach 4 and Mach 5 capabilities. These modifications will facilitate the testing of hypersonic air breathing propulsion systems for a wide range of flight conditions. A computational method to predict the thermodynamic, transport, and flow properties of the equilibrium chemically reacting oxygen enriched methane-air combustion products was implemented in a computer code. This code calculates the fuel, air, and oxygen mass flow rates and test section flow properties for Mach 7, 5, and 4 nozzle configurations for given combustor and mixer conditions. Salient features of the 8 ft HTT are described, and some of the predicted tunnel operational characteristics are presented in the carpet plots to assist users in preparing test plans.

  4. Temperature control transport system

    Science.gov (United States)

    Schabron, John F; Sorini-Wong, Susan S

    2014-12-09

    Embodiments of the inventive technology may involve the use of layered, insulated PCM assemblage that itself comprises: modular insulating foam material 8 that, upon establishment as part of the assemblage, defines inner foam material sides 9 and outer foam material sides 10; thin reflective material 11 established against (whether directly in contact with or not) at least either the inner foam material sides or the outer foam materials sides, and modular, enclosed PCM sections 12 established between the modular insulating foam material and the interior center.

  5. Isolating lattice from electronic contributions in thermal transport measurements of metals and alloys above ambient temperature and an adiabatic model

    Science.gov (United States)

    Criss, Everett M.; Hofmeister, Anne M.

    2017-06-01

    From femtosecond spectroscopy (fs-spectroscopy) of metals, electrons and phonons reequilibrate nearly independently, which contrasts with models of heat transfer at ordinary temperatures (T > 100 K). These electronic transfer models only agree with thermal conductivity (k) data at a single temperature, but do not agree with thermal diffusivity (D) data. To address the discrepancies, which are important to problems in solid state physics, we separately measured electronic (ele) and phononic (lat) components of D in many metals and alloys over ˜290-1100 K by varying measurement duration and sample length in laser-flash experiments. These mechanisms produce distinct diffusive responses in temperature versus time acquisitions because carrier speeds (u) and heat capacities (C) differ greatly. Electronic transport of heat only operates for a brief time after heat is applied because u is high. High Dele is associated with moderate T, long lengths, low electrical resistivity, and loss of ferromagnetism. Relationships of Dele and Dlat with physical properties support our assignments. Although kele reaches ˜20 × klat near 470 K, it is transient. Combining previous data on u with each D provides mean free paths and lifetimes that are consistent with ˜298 K fs-spectroscopy, and new values at high T. Our findings are consistent with nearly-free electrons absorbing and transmitting a small fraction of the incoming heat, whereas phonons absorb and transmit the majority. We model time-dependent, parallel heat transfer under adiabatic conditions which is one-dimensional in solids, as required by thermodynamic law. For noninteracting mechanisms, k≅ΣCikiΣCi/(ΣCi2). For metals, this reduces to k = klat above ˜20 K, consistent with our measurements, and shows that Meissner’s equation (k≅klat + kele) is invalid above ˜20 K. For one mechanism with multiple, interacting carriers, k≅ΣCiki/(ΣCi). Thus, certain dynamic behaviors of electrons and phonons in metals have been

  6. Temperature-dependent electrical characteristics and carrier transport mechanism of p-Cu2ZnSnS4/n-GaN heterojunctions

    Science.gov (United States)

    Niteesh Reddy, Varra; Reddy, M. Siva Pratap; Gunasekhar, K. R.; Lee, Jung-Hee

    2018-04-01

    This work explores the temperature-dependent electrical characteristics and carrier transport mechanism of Au/p-Cu2ZnSnS4/n-type GaN heterojunction (HJ) diodes with a CZTS interlayer. The electrical characteristics were examined by current-voltage-temperature, turn-on voltage-temperature and series resistance-temperature in the high-temperature range of 300-420 K. It is observed that an exponential decrease in the series resistance ( R S) and increase in the ideality factor ( n) and barrier height ( ϕ b) with increase in temperature. The thermal coefficient ( K j) is determined to be - 1.3 mV K-1 at ≥ 300 K. The effective ϕ b is determined to be 1.21 eV. This obtained barrier height is consistent with the theoretical one. The characteristic temperature ( T 0) resulting from the Cheung's functions [d V/d(ln I) vs. I and H( I) vs. I], is seen that there is good agreement between the T 0 values from both Cheung's functions. The relevant carrier transport mechanisms of Au/p-CZTS/n-type GaN HJ are explained based on the thermally decreased energy band gap of n-type GaN layers, thermally activated deep donors and increased further activated shallow donors.

  7. Characterization of temperature-dependent carrier transport in disordered indium-tin-oxide/poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate)/polyfluorene/Ca/Al polymer structures

    International Nuclear Information System (INIS)

    Jiang, Joe-Air; Wang, Jen-Cheng; Fang, Chia-Hui; Wu, Ya-Fen; Teng, Jen-Wei; Chen, Yu-Ting; Fan, Ping-Lin; Nee, Tzer-En

    2011-01-01

    The temperature-dependent electrical characteristics of polyfluorene-based polymer structures over a temperature range from 200 to 300 K are systematically investigated in this study. Initially, using the definitions of the Berthelot-type model, it is found that the sample exhibits a higher Berthelot-type temperature T B with high driving voltage, indicating that carrier transport in a disordered system manifests Berthelot-type behaviors. The ideal current density-voltage curve for the polymer structures given the carrier transmit mechanism is further elucidated by taking into account the ohmic conduction, trap charge limited current, and Mott and Gurney model of space charge limited current. The proposed procedure is simple and can be used to characterize the material with reasonable accuracy. We also study the density of the traps H t , and the characteristic energy of the distribution E t to better understand the carrier-transport process in organic materials and structures.

  8. Correlation between electrical transport, microstructure and room temperature ferromagnetism in 200 keV Ni{sup 2+} ion implanted zinc oxide (ZnO) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, B. [Gautam Buddha University, Department of Applied Sciences, Greater Noida (India); Ghosh, S.; Srivastava, P. [Indian Institute of Technology Delhi, Nanostech Laboratory, New Delhi (India); Kumar, P.; Kanjilal, D. [Aruna Asaf Ali Marg, Inter University Accelerator Centre, New Delhi (India)

    2012-05-15

    We report variable temperature resistivity measurements and mechanisms related to electrical conduction in 200 keV Ni{sup 2+} ion implanted ZnO thin films deposited by vapor phase transport. The dc electrical resistivity versus temperature curves show that all polycrystalline ZnO films are semiconducting in nature. In the room temperature range they exhibit band conduction and conduction due to thermionic emission of electrons from grain boundaries present in the polycrystalline films. In the low temperature range, nearest neighbor hopping (NNH) and variable range hopping (VRH) conduction are observed. The detailed conduction mechanism of these films and the effects of grain boundary (GB) barriers on the electrical conduction process are discussed. An attempt is made to correlate electrical conduction behavior and previously observed room temperature ferromagnetism of these films. (orig.)

  9. MO-E-17A-01: BEST IN PHYSICS (IMAGING) - Calculating SSDE From CT Exams Using Size Data Available in the DICOM Header of CT Localizer Radiographs

    International Nuclear Information System (INIS)

    McMillan, K; Bostani, M; McNitt-Gray, M; McCollough, C

    2014-01-01

    Purpose: To demonstrate the feasibility of using existing data stored within the DICOM header of certain CT localizer radiographs as a patient size metric for calculating CT size-specific dose estimates (SSDE). Methods: For most Siemens CT scanners, the CT localizer radiograph (topogram) contains a private DICOM field that stores an array of numbers describing AP and LAT attenuation-based measures of patient dimension. The square root of the product of the AP and LAT size data, which provides an estimate of water-equivalent-diameter (WED), was calculated retrospectively from topogram data of 20 patients who received clinically-indicated abdomen/pelvis (n=10) and chest (n=10) scans (WED-topo). In addition, slice-by-slice water-equivalent-diameter (WED-image) and effective diameter (ED-image) values were calculated from the respective image data. Using TG-204 lookup tables, size-dependent conversion factors were determined based upon WED-topo, WED-image and ED-image values. These conversion factors were used with the reported CTDIvol to calculate slice-by-slice SSDE for each method. Averaging over all slices, a single SSDE value was determined for each patient and size metric. Patientspecific SSDE and CTDIvol values were then compared with patientspecific organ doses derived from detailed Monte Carlo simulations of fixed tube current scans. Results: For abdomen/pelvis scans, the average difference between liver dose and CTDIvol, SSDE(WED-topo), SSDE(WED-image), and SSDE(ED-image) was 18.70%, 8.17%, 6.84%, and 7.58%, respectively. For chest scans, the average difference between lung dose and CTDIvol, SSDE(WED-topo), SSDE(WED-image), and SSDE(ED-image) was 25.80%, 3.33%, 4.11%, and 7.66%, respectively. Conclusion: SSDE calculated using WED derived from data in the DICOM header of the topogram was comparable to SSDE calculated using WED and ED derived from axial images; each of these estimated organ dose to within 10% for both abdomen/pelvis and chest CT examinations

  10. The influence of temperature and simulated transport conditions of diagnostic samples on real-time polymerase chain reaction for the detection of Tritrichomonas foetus DNA.

    Science.gov (United States)

    Clavijo, Alfonso; Erol, Erdal; Sneed, Loyd; Sun, Feng; Swinford, Amy

    2011-09-01

    Bovine trichomoniasis is a sexually transmitted disease in cattle that causes considerable economic loss due to abortions and infertility. In vitro culture of the organisms is the traditional method for diagnosis. However, culture cannot differentiate Tritrichomonas foetus from other, closely related nonpathogenic protozoa. Recently, a quantitative real-time polymerase chain reaction (qPCR) was developed for the differential diagnosis of trichomoniasis. The objective of the current work was to evaluate the effect of different simulated transport conditions on samples containing T. foetus for the diagnosis of trichomoniasis using culture and qPCR. Results indicate that transport temperatures of 4-20°C for 1-3 days before culture will reduce or temporarily inhibit parasite replication but maintain viability. Testing of samples by either culture or qPCR would be expected to give positive results. However, diagnosis of trichomonads by both methods was negatively affected when specimens were maintained at transport temperatures of 42°C for 24 hr or more. The current study stresses the importance of ensuring that clinical samples arrive to the diagnostic laboratory within 24-48 hr and of avoiding temperature transport conditions above 37°C in order to achieve an accurate diagnosis of trichomoniasis in cattle.

  11. TRITIUM PERMEATION AND TRANSPORT IN THE GASOLINE PRODUCTION SYSTEM COUPLED WITH HIGH TEMPERATURE GAS-COOLED REACTORS (HTGRS)

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim; Mike Patterson

    2011-05-01

    This paper describes scoping analyses on tritium behaviors in the HTGR-integrated gasoline production system, which is based on a methanol-to-gasoline (MTG) plant. In this system, the HTGR transfers heat and electricity to the MTG system. This system was analyzed using the TPAC code, which was recently developed by Idaho National Laboratory. The global sensitivity analyses were performed to understand and characterize tritium behaviors in the coupled HTGR/MTG system. This Monte Carlo based random sampling method was used to evaluate maximum 17,408 numbers of samples with different input values. According to the analyses, the average tritium concentration in the product gasoline is about 3.05×10-3 Bq/cm3, and 62 % cases are within the tritium effluent limit (= 3.7x10-3 Bq/cm3[STP]). About 0.19% of released tritium is finally transported from the core to the gasoline product through permeations. This study also identified that the following four parameters are important concerning tritium behaviors in the HTGR/MTG system: (1) tritium source, (2) wall thickness of process heat exchanger, (3) operating temperature, and (4) tritium permeation coefficient of process heat exchanger. These four parameters contribute about 95 % of the total output uncertainties. This study strongly recommends focusing our future research on these four parameters to improve modeling accuracy and to mitigate tritium permeation into the gasol ine product. If the permeation barrier is included in the future study, the tritium concentration will be significantly reduced.

  12. Amorphous Tin Oxide as a Low-Temperature-Processed Electron-Transport Layer for Organic and Hybrid Perovskite Solar Cells

    KAUST Repository

    Barbe, Jeremy

    2017-02-08

    Chemical bath deposition (CBD) of tin oxide (SnO) thin films as an electron-transport layer (ETL) in a planar-heterojunction n-i-p organohalide lead perovskite and organic bulk-heterojunction (BHJ) solar cells is reported. The amorphous SnO (a-SnO) films are grown from a nontoxic aqueous bath of tin chloride at a very low temperature (55 °C) and do not require postannealing treatment to work very effectively as an ETL in a planar-heterojunction n-i-p organohalide lead perovskite or organic BHJ solar cells, in lieu of the commonly used ETL materials titanium oxide (TiO) and zinc oxide (ZnO), respectively. Ultraviolet photoelectron spectroscopy measurements on the glass/indium-tin oxide (ITO)/SnO/methylammonium lead iodide (MAPbI)/2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene device stack indicate that extraction of photogenerated electrons is facilitated by a perfect alignment of the conduction bands at the SnO/MAPbI interface, while the deep valence band of SnO ensures strong hole-blocking properties. Despite exhibiting very low electron mobility, the excellent interfacial energetics combined with high transparency (E > 4 eV) and uniform substrate coverage make the a-SnO ETL prepared by CBD an excellent candidate for the potentially low-cost and large-scale fabrication of organohalide lead perovskite and organic photovoltaics.

  13. Effect of sorbed methanol, current, and temperature on multicomponent transport in nafion-based direct methanol fuel cells.

    Science.gov (United States)

    Rivera, Harry; Lawton, Jamie S; Budil, David E; Smotkin, Eugene S

    2008-07-24

    The CO2 in the cathode exhaust of a liquid feed direct methanol fuel cell (DMFC) has two sources: methanol diffuses through the membrane electrode assembly (MEA) to the cathode where it is catalytically oxidized to CO2; additionally, a portion of the CO2 produced at the anode diffuses through the MEA to the cathode. The potential-dependent CO2 exhaust from the cathode was monitored by online electrochemical mass spectrometry (ECMS) with air and with H2 at the cathode. The precise determination of the crossover rates of methanol and CO2, enabled by the subtractive normalization of the methanol/air to the methanol/H2 ECMS data, shows that methanol decreases the membrane viscosity and thus increases the diffusion coefficients of sorbed membrane components. The crossover of CO2 initially increases linearly with the Faradaic oxidation of methanol, reaches a temperature-dependent maximum, and then decreases. The membrane viscosity progressively increases as methanol is electrochemically depleted from the anode/electrolyte interface. The crossover maximum occurs when the current dependence of the diffusion coefficients and membrane CO2 solubility dominate over the Faradaic production of CO2. The plasticizing effect of methanol is corroborated by measurements of the rotational diffusion of TEMPONE (2,2,6,6-tetramethyl-4-piperidone N-oxide) spin probe by electron spin resonance spectroscopy. A linear inverse relationship between the methanol crossover rate and current density confirms the absence of methanol electro-osmotic drag at concentrations relevant to operating DMFCs. The purely diffusive transport of methanol is explained in terms of current proton solvation and methanol-water incomplete mixing theories.

  14. Amorphous Tin Oxide as a Low-Temperature-Processed Electron-Transport Layer for Organic and Hybrid Perovskite Solar Cells.

    Science.gov (United States)

    Barbé, Jérémy; Tietze, Max L; Neophytou, Marios; Murali, Banavoth; Alarousu, Erkki; Labban, Abdulrahman El; Abulikemu, Mutalifu; Yue, Wan; Mohammed, Omar F; McCulloch, Iain; Amassian, Aram; Del Gobbo, Silvano

    2017-04-05

    Chemical bath deposition (CBD) of tin oxide (SnO 2 ) thin films as an electron-transport layer (ETL) in a planar-heterojunction n-i-p organohalide lead perovskite and organic bulk-heterojunction (BHJ) solar cells is reported. The amorphous SnO 2 (a-SnO 2 ) films are grown from a nontoxic aqueous bath of tin chloride at a very low temperature (55 °C) and do not require postannealing treatment to work very effectively as an ETL in a planar-heterojunction n-i-p organohalide lead perovskite or organic BHJ solar cells, in lieu of the commonly used ETL materials titanium oxide (TiO 2 ) and zinc oxide (ZnO), respectively. Ultraviolet photoelectron spectroscopy measurements on the glass/indium-tin oxide (ITO)/SnO 2 /methylammonium lead iodide (MAPbI 3 )/2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene device stack indicate that extraction of photogenerated electrons is facilitated by a perfect alignment of the conduction bands at the SnO 2 /MAPbI 3 interface, while the deep valence band of SnO 2 ensures strong hole-blocking properties. Despite exhibiting very low electron mobility, the excellent interfacial energetics combined with high transparency (E gap,optical > 4 eV) and uniform substrate coverage make the a-SnO 2 ETL prepared by CBD an excellent candidate for the potentially low-cost and large-scale fabrication of organohalide lead perovskite and organic photovoltaics.

  15. Effects of interactive transport and scavenging of smoke on the calculated temperature change resulting from large amounts of smoke

    International Nuclear Information System (INIS)

    MacCracken, M.C.; Walton, J.J.

    1984-12-01

    Several theoretical studies with numerical models have shown that substantial land-surface cooling can occur if very large amounts (approx. 100 x 10 12 = 100 Tg) of highly absorbing sooty-particles are injected high into the troposphere and spread instantaneously around the hemisphere (Turco et al., 1983; Covey et al. 1984; MacCracken, 1983). A preliminary step beyond these initial calculations has been made by interactively coupling the two-layer, three-dimensional Oregon State University general circulation model (GCM) to the three-dimensional GRANTOUR trace species model developed at the Lawrence Livermore National Laboratory. The GCM simulation includes treatment of tropospheric dynamics and thermodynamics and the effect of soot on solar radiation. The GRANTOUR simulation includes treatment of particle transport and scavenging by precipitation, although no satisfactory verification of the scavenging algorithm has yet been possible. We have considered the climatic effects of 150 Tg (i.e., the 100 Mt urban war scenario from Turco et al., 1983) and of 15 Tg of smoke from urban fires over North America and Eurasia. Starting with a perpetual July atmospheric situation, calculation of the climatic effects as 150 Tg of smoke are spread slowly by the winds, rather than instantaneously dispersed as in previous calculations, leads to some regions of greater cooling under the denser parts of the smoke plumes and some regions of less severe cooling where smoke arrival is delayed. As for the previous calculations, mid-latitude decreases of land surface air temperature for the 150 Tg injection are greater than 15 0 C after a few weeks. For a 15 Tg injection, however, cooling of more than several degrees centigrade only occurs in limited regions under the dense smoke plumes present in the first few weeks after the injection. 10 references, 9 figures

  16. Temperature-Dependent Electrical Properties and Carrier Transport Mechanisms of TMAH-Treated Ni/Au/Al2O3/GaN MIS Diode

    Science.gov (United States)

    Reddy, M. Siva Pratap; Puneetha, Peddathimula; Reddy, V. Rajagopal; Lee, Jung-Hee; Jeong, Seong-Hoon; Park, Chinho

    2016-11-01

    The temperature-dependent electrical properties and carrier transport mechanisms of tetramethylammonium hydroxide (TMAH)-treated Ni/Au/Al2O3/GaN metal-insulator-semiconductor (MIS) diodes have been investigated by current-voltage ( I- V) and capacitance-voltage ( C- V) measurements. The experimental results reveal that the barrier height ( I- V) increases whereas the ideality factor decreases with increasing temperature. The TMAH-treated Ni/Au/Al2O3/GaN MIS diode showed nonideal behaviors which indicate the presence of a nonuniform distribution of interface states ( N SS) and effect of series resistance ( R S). The obtained R S and N SS were found to decrease with increasing temperature. Furthermore, it was found that different transport mechanisms dominated in the TMAH-treated Ni/Au/Al2O3/GaN MIS diode. At 150 K to 250 K, Poole-Frenkel emission (PFE) was found to be responsible for the reverse leakage, while Schottky emission (SE) was the dominant mechanism at high electric fields in the temperature range from 300 K to 400 K. Feasible energy band diagrams and possible carrier transport mechanisms for the TMAH-treated Ni/Au/Al2O3/GaN MIS diode are discussed based on PFE and SE.

  17. A Surface-Layer Study of the Transport and Dissipation of Turbulent Kinetic Energy and the Variances of Temperature, Humidity and CO_2

    Science.gov (United States)

    Hackerott, João A.; Bakhoday Paskyabi, Mostafa; Reuder, Joachim; de Oliveira, Amauri P.; Kral, Stephan T.; Marques Filho, Edson P.; Mesquita, Michel dos Santos; de Camargo, Ricardo

    2017-11-01

    We discuss scalar similarities and dissimilarities based on analysis of the dissipation terms in the variance budget equations, considering the turbulent kinetic energy and the variances of temperature, specific humidity and specific CO_2 content. For this purpose, 124 high-frequency sampled segments are selected from the Boundary Layer Late Afternoon and Sunset Turbulence experiment. The consequences of dissipation similarity in the variance transport are also discussed and quantified. The results show that, for the convective atmospheric surface layer, the non-dimensional dissipation terms can be expressed in the framework of Monin-Obukhov similarity theory and are independent of whether the variable is temperature or moisture. The scalar similarity in the dissipation term implies that the characteristic scales of the atmospheric surface layer can be estimated from the respective rate of variance dissipation, the characteristic scale of temperature, and the dissipation rate of temperature variance.

  18. Temperature in the Primary Heat Transport Pump Bearing of the Nuclear Power Plant 'Embalse Rio Tercero' in view of the Cutting of the Service Water

    International Nuclear Information System (INIS)

    Raffo, J.L

    2001-01-01

    This study contains the analysis of the Primary Heat Transport Pump Bearing of the Nuclear Power Plant 'Embalse Rio Tercero', Cordoba, Argentine, in view of the cutting of the Service Water refrigeration which cools the Gland Seal System.This takes two ways: One is the study of the temperature rise of the water that cools the carbon bearing and the time involved.This is supported upon manuals and drawings.The other, on the temperature distribution in different operating conditions.This has been done by the simulation of the normal and transient conditions in the software COSMOS/M

  19. Growth of Escherichia coli O157:H7 and Listeria monocytogenes in packaged fresh-cut romaine mix at fluctuating temperatures during commercial transport, retail storage, and display.

    Science.gov (United States)

    Zeng, Wenting; Vorst, Keith; Brown, Wyatt; Marks, Bradley P; Jeong, Sanghyup; Pérez-Rodríguez, Fernando; Ryser, Elliot T

    2014-02-01

    Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study-the first using commercial time/temperature profiles to assess the microbial risk of leafy greens-should be useful in filling some of the data gaps in current risk assessments for leafy greens.

  20. Low-temperature solution-processed hydrogen molybdenum and vanadium bronzes for an efficient hole-transport layer in organic electronics.

    Science.gov (United States)

    Xie, Fengxian; Choy, Wallace C H; Wang, Chuandao; Li, Xinchen; Zhang, Shaoqing; Hou, Jianhui

    2013-04-11

    A simple one-step method is reported to synthesize low-temperature solution-processed transition metal oxides (TMOs) of molybdenum oxide and vanadium oxide with oxygen vacancies for a good hole-transport layer (HTL). The oxygen vacancy plays an essential role for TMOs when they are employed as HTLs: TMO films with excess oxygen are highly undesirable for their application in organic electronics. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Transport characteristics of Pd Schottky barrier diodes on epitaxial n-GaSb as determined from temperature dependent current–voltage measurements

    Energy Technology Data Exchange (ETDEWEB)

    Venter, A., E-mail: andre.venter@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Murape, D.M.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Auret, F.D. [Department of Physics, University of the Pretoria, Lynnwood Road, Pretoria 0002 (South Africa)

    2015-01-01

    The temperature dependent transport characteristics of Pd/n-GaSb:Te Schottky contacts with low and saturating reverse current are investigated by means of current–voltage measurements between 80 K and 320 K. The apparent barrier height and ideality factor increase with a decrease in temperature. Neither thermionic nor thermionic field emission can explain the low temperature characteristics of these diodes. Instead, evidence is presented for barrier inhomogeneity across the metal/semiconductor contact. A plot of the barrier height, ϕ{sub b} vs. 1/2kT revealed a double Gaussian distribution for the barrier height with ϕ{sub b,mean} assuming values of 0.59 eV ± 0.07 (80–140 K) and 0.25 eV ± 0.12 (140–320 K) respectively. - Highlights: • Transport characteristics of Pd/epitaxial n-GaSb:Te SBDs are studied by means of I-V-T measurements. • SBDs have remarkably low and saturating reverse current – of the lowest ever reported for GaSb. • Transport behaviour is explained by considering electronic states present on the GaSb surface. • Evidence is presented for barrier inhomogeneity across the metal-semiconductor contact.

  2. Low temperature ballistic spin transport in the S=1/2 antiferromagnetic Heisenberg chain compound SrCuO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Maeter, H.; Klauss, H.H. [Institut fuer Festkoerperphysik, TU Dresden (Germany); Zvyagin, A.A. [Institut fuer Festkoerperphysik, TU Dresden (Germany); Institute for Low Temperature Physics and Engineering, NAS of Ukraine, Kharkov (Ukraine); Luetkens, H.; Pascua, G.; Shermadini, Z. [Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute, Villigen (Switzerland); Hess, C.; Hlubek, N.; Buechner, B. [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung, Dresden (Germany); Saint-Matin, R.; Revcolevschi, A. [Laboratoire de Physico-Chimie de L' Etat Solide, ICMMO, UMR 8182, Universite Paris-Sud, Orsay (France)

    2011-07-01

    For one-dimensional quantum spin chain systems recent experimental and theoretical studies indicate unexpectedly large, in some cases diverging spin and heat transport coefficients. Local probes, like e.g. muon spin relaxation ({mu}SR) can indirectly characterize the spin transport properties of low dimensional systems via the magnetic field dependence of the spin lattice relaxation rate {lambda}(B). For diffusive spin transport {lambda}{proportional_to}B{sup -0.5} is expected. For the ground state of the isotropic spin-1/2 antiferromagnetic Heisenberg chain the eigenstates of the Heisenberg Hamiltonian dominate the spin transport, which is then ballistic. Using the Mueller ansatz {lambda}{proportional_to}B{sup -1} is expected in this case. For SrCuO{sub 2} we find {lambda}{proportional_to}B{sup -0.9(3)}. This result is temperature independent for 5 K{<=}T {<=}300 K. Within conformal field theory and using the Mueller ansatz we conclude ballistic spin transport in SrCuO{sub 2}.

  3. Specifications for refrigerating transport. More rigid temperature specifications for cooling transport; Anforderungen im Transportkaeltebereich. Erhoehte Anforderungen beim Kuehltransport wegen verschaerfter Temperaturvorschriften

    Energy Technology Data Exchange (ETDEWEB)

    Grosskopf, P. [Frigoblock Grosskopf GmbH, Essen (Germany)

    2002-09-01

    The recommendations of the Federal Institute of Consumer Health Protection and Veterinary Medicine (Bundesinstitut fuer gesundheitlichen Verbraucherschutz und Veterinaermedizin, BgVV), which sums up all German and European temperature specifications for fresh and refrigerated products, as well as the new Ordinance on Refrigerated food (Verordnung ueber tiefgefrorene Lebensmittel, TLMV) and the new German Ordinance on Food Hygiene (Lebensmittelhygieneverordnjung,LMHV) including temperature monitoring specifications according to HACCP, induced these associations to draw up practical recommendations and guidelines for their members. [German] Die Temperaturempfehlungen des Bundesinstituts fuer gesundheitlichen Verbraucherschutz und Veterinaermedizin (BgVV), die alle deutschen und europaeischen Temperaturvorschriften fuer Frisch- und Tiefkuehlprodukte zusammenfassen sowie die Neufassung der Verordnung ueber tiefgefrorene Lebensmittel (TLMV) und die neue bundeseinheitliche Lebensmittelhygiene-Verordnung (LMHV) inkl. der Temperaturueberwachungsvorschriften gemaess HACCP, haben die betroffenen Verbaende veranlasst, entsprechende Praxisempfehlungen und Leitlinien fuer ihre Mitglieder zu erarbeiten. (orig.)

  4. Temperature dependent charge transport studies across thermodynamic glass transition in P3HT:PCBM bulk heterojunction: insight from J-V and impedance spectroscopy

    Science.gov (United States)

    Sarkar, Atri; Rahaman, Abdulla Bin; Banerjee, Debamalya

    2018-03-01

    Temperature dependent charge transport properties of P3HT:PCBM bulk heterojunction are analysed by dc and ac measurements under dark conditions across a wide temperature range of 110-473 K, which includes the thermodynamic glass transition temperature (Tg ˜320 K) of the system. A change from Ohmic conduction to space charge limited current conduction at higher (⩾1.2 V) applied bias voltages above  ⩾200 K is observed from J-V characteristics. From capacitance-voltage (C-V) measurement at room temperature, the occurrence of a peak near the built-in voltage is observed below the dielectric relaxation frequency, originating from the competition between drift and diffusion driven motions of charges. Carrier concentration (N) is calculated from C-V measurements taken at different temperatures. Room temperature mobility values at various applied bias voltages are in accordance with that obtained from transient charge extraction by linearly increasing voltage measurement. Sample impedance is measured over five decades of frequency across temperature range by using lock-in detection. This data is used to extract temperature dependence of carrier mobility (μ), and dc conductivity (σ_dc ) which is low frequency extrapolation of ac conductivity. An activation energy of  ˜126 meV for the carrier hopping process at the metal-semiconductor interface is estimated from temperature dependence of σ_dc . Above T g, μ levels off to a constant value, whereas σ_dc starts to decrease after a transition knee at T g that can be seen as a combined effect of changes in μ and N. All these observed changes across T g can be correlated to enhanced polymer motion above the glass transition.

  5. Study of Exciton Hopping Transport in PbS Colloidal Quantum Dot Thin Films Using Frequency- and Temperature-Scanned Photocarrier Radiometry

    Science.gov (United States)

    Hu, Lilei; Mandelis, Andreas; Melnikov, Alexander; Lan, Xinzheng; Hoogland, Sjoerd; Sargent, Edward H.

    2017-01-01

    Solution-processed colloidal quantum dots (CQDs) are promising materials for realizing low-cost, large-area, and flexible photovoltaic devices. The study of charge carrier transport in quantum dot solids is essential for understanding energy conversion mechanisms. Recently, solution-processed two-layer oleic-acid-capped PbS CQD solar cells with one layer treated with tetrabutylammonium iodide (TBAI) serving as the main light-absorbing layer and the other treated with 1,2-ethanedithiol (EDT) acting as an electron-blocking/hole-extraction layer were reported. These solar cells demonstrated a significant improvement in power conversion efficiency of 8.55% and long-term air stability. Coupled with photocarrier radiometry measurements, this work used a new trap-state mediated exciton hopping transport model, specifically for CQD thin films, to unveil and quantify exciton transport mechanisms through the extraction of hopping transport parameters including exciton lifetimes, hopping diffusivity, exciton detrapping time, and trap-state density. It is shown that PbS-TBAI has higher trap-state density than PbS-EDT that results in higher PbS-EDT exciton lifetimes. Hopping diffusivities of both CQD thin film types show similar temperature dependence, particularly higher temperatures yield higher hopping diffusivity. The higher diffusivity of PbS-TBAI compared with PbS-EDT indicates that PbS-TBAI is a much better photovoltaic material than PbS-EDT. Furthermore, PCR temperature spectra and deep-level photothermal spectroscopy provided additional insights to CQD surface trap states: PbS-TBAI thin films exhibit a single dominant trap level, while PbS-EDT films with lower trap-state densities show multiple trap levels.

  6. Substrate Temperature Effect on Charge Transport Performance of ZnO Electron Transport Layer Prepared by a Facile Ultrasonic Spray Pyrolysis in Polymer Solar Cells

    Directory of Open Access Journals (Sweden)

    Jiang Cheng

    2015-01-01

    Full Text Available A novel ultrasonic spray pyrolysis for high-quality ZnO films based on zinc-ammonia solution was achieved in air. To investigate the structural and optical properties as well as the performance of polymer solar cells (PSCs, ZnO films at different substrate temperatures and thicknesses were prepared. The performance of poly(3-hexylthiophene:[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM based PSC was found to be improved due to the ZnO films. The crystal structure and roughness of the ZnO films fabricated at different temperatures were found to affect the performance of PSCs. The optimized power conversion efficiency was found to be maximum for PSCs with ZnO films prepared at 200°C. The growth process of these ZnO films is very simple, cost-effective, and compatible for larger-scale PSC preparation. The precursor used for spray pyrolysis is environmentally friendly and helps to achieve ZnO film preparation at a relative low temperature.

  7. The low temperature specific heat and electrical transport, magnetic properties of Pr{sub 0.65}Ca{sub 0.35}MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Han, Zhiyong, E-mail: zyhan@cauc.edu.cn

    2017-02-01

    The magnetic properties, electrical transport properties, and low temperature specific heat of polycrystalline perovskite manganese oxide Pr{sub 0.65}Ca{sub 0.35}MnO{sub 3} have been investigated experimentally. It is found that there exists cluster glass state in the sample at low temperature besides the antiferromagnetic insulating state. With the increase of magnetic field, antiferromagnetic insulating state converts to ferromagnetic metal state and the Debye temperature decreases gradually. In addition, the low temperature electron specific heat in zero magnetic field is obviously larger than that of ordinary rare-earth manganites oxide and this phenomenon is related to the itinerant electrons in ferromagnetic cluster state and the disorder in Pr{sub 0.65}Ca{sub 0.35}MnO{sub 3}. - Highlights: • There exists cluster glass state in the sample at low temperature besides the antiferromagnetic insulating state. • With the increase of magnetic field, antiferromagnetic insulating state converts to ferromagnetic metal state. • Low temperature electron specific heat in zero magnetic field is larger than that of ordinary rare-earth manganites oxide.

  8. CFD analysis of moderator flow and temperature fields inside a vertical calandria vessel of nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kansal, Anuj Kumar, E-mail: akansal@barc.gov.in [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Joshi, Jyeshtharaj B., E-mail: jbjoshi@gmail.com [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Maheshwari, Naresh Kumar, E-mail: nmahesh@barc.gov.in [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Vijayan, Pallippattu Krishnan, E-mail: vijayanp@barc.gov.in [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2015-06-15

    Highlights: • 3D CFD of vertical calandria vessel. • Spatial distribution of volumetric heat generation. • Effect of Archimedes number. • Non-dimensional analysis. - Abstract: Three dimensional computational fluid dynamics (CFD) analysis has been performed for the moderator flow and temperature fields inside a vertical calandria vessel of nuclear reactor under normal operating condition using OpenFOAM CFD code. OpenFOAM is validated by comparing the predicted results with the experimental data available in literature. CFD model includes the calandria vessel, calandria tubes, inlet header and outlet header. Analysis has been performed for the cases of uniform and spatial distribution of volumetric heat generation. Studies show that the maximum temperature in moderator is lower in the case of spatial distribution of heat generation as compared to that in the uniform heat generation in calandria. In addition, the effect of Archimedes number on maximum and average moderator temperature was investigated.

  9. Transport properties of bilayer graphene due to charged impurity scattering: Temperature-dependent screening and substrate effects

    Science.gov (United States)

    Linh, Dang Khanh; Khanh, Nguyen Quoc

    2018-03-01

    We calculate the zero-temperature conductivity of bilayer graphene (BLG) impacted by Coulomb impurity scattering using four different screening models: unscreened, Thomas-Fermi (TF), overscreened and random phase approximation (RPA). We also calculate the conductivity and thermal conductance of BLG using TF, zero- and finite-temperature RPA screening functions. We find large differences between the results of the models and show that TF and finite-temperature RPA give similar results for diffusion thermopower Sd. Using the finite-temperature RPA, we calculate temperature and density dependence of Sd in BLG on SiO2, HfO2 substrates and suspended BLG for different values of interlayer distance c and distance between the first layer and the substrate d.

  10. Effect of room temperature transport vials on DNA quality and phylogenetic composition of faecal microbiota of elderly adults and infants.

    LENUS (Irish Health Repository)

    Hill, Cian J

    2016-05-01

    Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults.

  11. Investigation on cause of outage of Wide Range Monitor (WRM) in High Temperature engineering Test Reactor (HTTR). Transport operation toward investigation for cause of outage

    International Nuclear Information System (INIS)

    Shinohara, Masanori; Sawahata, Hiroaki; Kawamoto, Taiki; Saito, Kenji; Takada, Shoji; Yoshida, Naoaki; Isozaki, Ryosuke; Katsuyama, Kozo; Motegi, Toshihiro

    2012-08-01

    An event, in which one of WRMs were disabled to detect the neutron flux in the reactor core, occurred during the period of reactor shut down of HTTR in March, 2010. The actual life time of WRM was unexpectedly shorter than the past developed life time. Investigation of the cause of the outage of WRM toward the recovery of the life time up to the developed life is one of the issues to develop the technology basis of High Temperature Gas cooled Reactor (HTGR). Then, a post irradiation examination was planned to specify the damaged part causing the event in the WRM was also planned. For the investigation, the X-ray computed tomography scanner in Fuels Monitoring Facility (FMF). This report describes the preliminary investigation on the cause of outage of the WRM. The results of study for transportation method of the irradiated WRM from HTTR to FMF is also reported with the record to complete the transport operation. (author)

  12. Conductivity Modulation of Gold Thin Film at Room Temperature via All-Solid-State Electric-Double-Layer Gating Accelerated by Nonlinear Ionic Transport.

    Science.gov (United States)

    Asano, Tetsuya; Kaneko, Yukihiro; Omote, Atsushi; Adachi, Hideaki; Fujii, Eiji

    2017-02-15

    We demonstrated the field-effect conductivity modulation of a gold thin film by all-solid-state electric-double-layer (EDL) gating at room temperature using an epitaxially grown oxide fast lithium conductor, La 2/3-x Li 3x TiO 3 (LLT), as a solid electrolyte. The linearly increasing gold conductivity with increasing gate bias demonstrates that the conductivity modulation is indeed due to carrier injection by EDL gating. The response time becomes exponentially faster with increasing gate bias, a result of the onset of nonlinear ionic transportation. This nonlinear dynamic response indicates that the ionic motion-driven device can be much faster than would be estimated from a linear ionic transport model.

  13. One-Dimensional Reactive Transport Modeling of CO2 Storage Systems - Change in Cap Rock Porosity Triggered by Pressure and Temperature Dependent CO2-Water-Rock Interactions

    Science.gov (United States)

    Hemme, C.; van Berk, W.

    2015-12-01

    In carbon capture and storage (CCS) systems supercritical CO2 is injected into a reservoir and dissolves in the reservoir brine. Subsequently, CO2(aq) diffuses into the cap rock to regions of lower total pressure and temperature and triggers CO2-water-rock interactions that are coupled with mass transport and result in precipitation and/or dissolution of minerals along the CO2 migration path. Such hydrogeochemical interactions change porosities and are responsible for the improvement or deterioration of the long term integrity of the system. This study presents a semi-generic hydrogeochemical model based on chemical equilibrium thermodynamics, data from several CO2 storage systems, and plausible assumptions regarding non-available data. One-dimensional reactive transport modeling is performed by using the U.S.G.S. PHREEQC code (3.1.4-8929; phreeqc.dat database) to identify and quantify the loss or gain of total porosity affected by hydrogeochemical reactions driven by diffusive mass transport exposed to pressure and temperature gradients. A fine spatial and temporal discretization, the use of non-reactive tracers, and a broad variety of modeling scenarios enable the calculation of the relevant timescale for simulations of long-term storage of CO2 and the consideration of the pressure dependent mass action law constants along the CO2 migration path. Modeling results show that the relevant timescale for simulations of long-term storage of CO2 is in the range of 106 years, and that pressure/temperature conditions, heterogeneities (veins and fractures) and the mineralogical composition of the cap rock have the strongest influence on the increase in cap rock porosity (maximum increase from initial 5 % to 7.5 %). Critical parameter combinations - total pressure effects are crucial - could put long-term integrity at risks. Nevertheless, a wide range of conditions and parameter combinations for safe CO2 storage is identified by other modeling scenarios.

  14. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 2: Compositions corresponding to Kelvin temperature schedules in part 1

    Science.gov (United States)

    Gordon, S.

    1982-01-01

    The equilibrium compositions that correspond to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. Initially 55 gaseous species and 3 coin condensed species were considered in the calculations. Only 17 of these 55 gaseous species had equilibrium mole fractions greater than 0.000005 for any of the conditions studied and therefore these were the only ones retained in the final tables.

  15. Determination of transient fluid temperature using the inverse method

    Directory of Open Access Journals (Sweden)

    Jaremkiewicz Magdalena

    2014-03-01

    Full Text Available This paper proposes an inverse method to obtain accurate measurements of the transient temperature of fluid. A method for unit step and linear rise of temperature is presented. For this purpose, the thermometer housing is modelled as a full cylindrical element (with no inner hole, divided into four control volumes. Using the control volume method, the heat balance equations can be written for each of the nodes for each of the control volumes. Thus, for a known temperature in the middle of the cylindrical element, the distribution of temperature in three nodes and heat flux at the outer surface were obtained. For a known value of the heat transfer coefficient the temperature of the fluid can be calculated using the boundary condition. Additionally, results of experimental research are presented. The research was carried out during the start-up of an experimental installation, which comprises: a steam generator unit, an installation for boiler feed water treatment, a tray-type deaerator, a blow down flashvessel for heat recovery, a steam pressure reduction station, a boiler control system and a steam header made of martensitic high alloy P91 steel. Based on temperature measurements made in the steam header using the inverse method, accurate measurements of the transient temperature of the steam were obtained. The results of the calculations are compared with the real temperature of the steam, which can be determined for a known pressure and enthalpy.

  16. Development of Tritium Permeation Analysis Code and Tritium Transport in a High Temperature Gas-Cooled Reactor Coupled with Hydrogen Production System

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim; Mike Patterson

    2010-06-01

    Abstract – A tritium permeation analyses code (TPAC) was developed by Idaho National Laboratory for the purpose of analyzing tritium distributions in very high temperature reactor (VHTR) systems, including integrated hydrogen production systems. A MATLAB SIMULINK software package was used in developing the code. The TPAC is based on the mass balance equations of tritium-containing species and various forms of hydrogen coupled with a variety of tritium sources, sinks, and permeation models. In the TPAC, ternary fission and neutron reactions with 6Li, 7Li 10B, and 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of tritium and H2 through pipes, vessels, and heat exchangers were considered as main tritium transport paths. In addition, electroyzer and isotope exchange models were developed for analyzing hydrogen production systems, including high temperature electrolysis and sulfur-iodine processes.

  17. Application of thermohydraulic dispatcher in low temperature district heating systems for decreasing heat carrier transportation energy cost and increasing reliability of heat supply

    Science.gov (United States)

    Yavorovsky, Y. V.; Romanov, D. O.; Sennikov, V. V.; Sultanguzin, I. A.; Malenkov, A. S.; Zhigulina, E. V.; Lulaev, A. V.

    2017-11-01

    Low pressure district heating systems have low breakdown rate and allow decreasing heat carrier transportation energy cost by means of avoiding throttling of available water head. One of the basic elements of such systems is thermohydraulic dispatcher (THD) which separates primary circuit and secondary circuit (or circuits) that allows avoiding mutual hydraulic influence of circuits on each other and reducing water heads of network pumps. Analysis of perspective ways of using thermohydraulic dispatcher (THD) in low temperature district heating systems is made in this paper. Principal scheme and mathematical model of low pressure and temperature district heating system based on CHP generation with THD are considered. The main advantages of such systems are pointed out.

  18. A newly developed container for safe, easy, and cost-effective overnight transportation of tissues and organs by electrically keeping tissue or organ temperature at 3 to 6°C.

    Science.gov (United States)

    Ohkawara, H; Kitagawa, T; Fukushima, N; Ito, T; Sawa, Y; Yoshimine, T

    2012-05-01

    As there is only one skin procurement organization in Japan the Japan Skin Bank Network (JSBN), all skin grafts procured in Japan are sent by a commercialized delivery system. Preliminarily, bottles containing saline were transported in a cardboard box using a so-called "cooled home delivery service" using a truck with a refrigerated cargo container. During transportation the temperature in the cardboard box increased to 18°C in summer and decreased to -5°C in winter. For these reasons, we investigated whether a newly developed container "Medi Cube" would be useful to transport skin grafts. Four bottles with a capacity of 300 mL containing 150 mL of saline in a Medi Cube container were transported from Osaka to the JSBN in Tokyo between 4 PM and 10 AM using a commercialized cooled home delivery service. Two bottles were transported in a Medi Cube container without phase change materials (PCM) in winter and summer, respectively. Another two bottles were transported in the Medi Cube with PCMs in winter. The temperatures inside saline, inside a transportation container, and outside the container, and air temperature were monitored continuously with a recordable thermometer. The temperatures inside saline and inside a Medi Cube container were maintained between 3 and 6°C, even when the temperature outside the container increased during parking. The temperature inside a Medi Cube container without PCM decreased to -3°C when the inside of the cargo container was overcooled in winter. However, the temperatures inside saline and inside a Medi Cube container with PCM were between 3 and 6°C, even when the temperature outside the container decreased to below 0°C in winter. A Medi Cube container with PCM provided a safe, easy, and cost-effective method for overnight transportation of skin grafts. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Osmolality, temperature, and membrane lipid composition modulate the activity of betaine transporter BetP in Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Ozcan, Nuran; Ejsing, Christer S.; Shevchenko, Andrej

    2007-01-01

    , BetP, is instantly activated in response to an increasing cytoplasmic K(+) concentration. Importantly, it is also activated by chill stress independent of osmotic stress. We show that the activation of BetP by both osmotic stress and chill stress is altered in C. glutamicum cells grown at and adapted...... to low temperatures. BetP from cold-adapted cells is less sensitive to osmotic stress. In order to become susceptible for chill activation, cold-adapted cells in addition needed a certain amount of osmotic stimulation, indicating that there is cross talk of these two types of stimuli at the level of Bet......P activity. We further correlated the change in BetP regulation properties in cells grown at different temperatures to changes in the lipid composition of the plasma membrane. For this purpose, the glycerophospholipidome of C. glutamicum grown at different temperatures was analyzed by mass spectrometry using...

  20. Impact of Temperature and Hydrological Residence Time on the Fate and Transport of Iron and Organic Carbon in Subalpine Wetlands

    Science.gov (United States)

    Schneider, L. M.; Borch, T.; Rhoades, C.; Pallud, C. E.

    2015-12-01

    Wetlands contain one third of the planet's soil carbon (C) and are characterized by markedly different chemical and physical environments than terrestrial ecosystems. The hydrologic residence time and temperature in wetlands influences their redox conditions and thus biogeochemical reaction rates. In these environments, transformation and movement of C and iron (Fe) are closely linked due to the sorption of organic C by solid Fe(III)-phases. Therefore, changes in Fe biogeochemical cycling will influence the size and turnover rate of soil C pools, which could negatively impact water quality and C storage. We examined the effects of hydrologic residence time and temperature on reduction of autochtonous Fe(III)-oxides. Fe(II)-export rates, used as a lower bound for bulk Fe(III)-reduction rates, and dissolved organic carbon (DOC) export rates were measured on intact mineral soil cores using flow-through reactor experiments exposed to temperatures based on mean annual conditions (6°, 12°, and 18°C). Soils were from a slope and a depressional subalpine wetland (USDA Fraser Experimental Forest, CO, USA), characterized by different hydrologic residence times, were compared. In the depressional wetland we observed the shallower soil depths have higher overall Fe(II)-export rates than the deeper soil depths. As temperature increases, Fe(II)-export rate increases, with a more than doubling in magnitude from 12 to 18° C. In comparing sites that are continuously inundated to those that are seasonally inundated, surprisingly we see higher Fe(II)-export rates in the seasonally inundated sites for all temperatures and depths. In the slope wetland we observed an opposite trend with depth and with temperature, with Fe(II)-export rates declining by almost an order of magnitude between 6 and 12°C. In addition, our results showed a positive correlation between Fe(II)-export rates and DOC export rates suggesting Fe(III)-reduction exerts a biogeochemical control on water quality

  1. Room-temperature nonlinear transport phenomena in low-dimensional Ni-Nb-Zr-H glassy alloys and its device

    Energy Technology Data Exchange (ETDEWEB)

    Fukuhara, Mikio; Yoshida, Hajime [Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba, Sendai, 980-8577 (Japan)

    2014-05-15

    We report the room-temperature switching and Coulomb blockade effects in three–terminal glassy alloy field effect transistor (GAFET), using the millimeter sized glassy alloy. By applying dc and ac voltages to a gate electrode, GAFET can be switched from a metallic conducting state to an insulating state with Coulomb oscillation at a period of 14 μV at room temperature. The transistor showed the three-dimensional Coulomb diamond structure. The fabrication of a low-energy controllable device throws a new light on cluster electronics without wiring.

  2. Metal/dielectric thermal interfacial transport considering cross-interface electron-phonon coupling: Theory, two-temperature molecular dynamics, and thermal circuit

    Science.gov (United States)

    Lu, Zexi; Wang, Yan; Ruan, Xiulin

    2016-02-01

    The standard two-temperature equations for electron-phonon coupled thermal transport across metal/nonmetal interfaces are modified to include the possible coupling between metal electrons with substrate phonons. The previous two-temperature molecular dynamics (TT-MD) approach is then extended to solve these equations numerically at the atomic scale, and the method is demonstrated using Cu/Si interface as an example. A key parameter in TT-MD is the nonlocal coupling distance of metal electrons and nonmetal phonons, and here we use two different approximations. The first is based on Overhauser's "joint-modes" concept, while we use an interfacial reconstruction region as the length scale of joint region rather than the phonon mean-free path as in Overhauser's original model. In this region, the metal electrons can couple to the joint phonon modes. The second approximation is the "phonon wavelength" concept where electrons couple to phonons nonlocally within the range of one phonon wavelength. Compared with the original TT-MD, including the cross-interface electron-phonon coupling can slightly reduce the total thermal boundary resistance. Whether the electron-phonon coupling within the metal block is nonlocal or not does not make an obvious difference in the heat transfer process. Based on the temperature profiles from TT-MD, we construct a new mixed series-parallel thermal circuit. We show that such a thermal circuit is essential for understanding metal/nonmetal interfacial transport, while calculating a single resistance without solving temperature profiles as done in most previous studies is generally incomplete. As a comparison, the simple series circuit that neglects the cross-interface electron-phonon coupling could overestimate the interfacial resistance, while the simple parallel circuit in the original Overhauser's model underestimates the total interfacial resistance.

  3. Influence of the binder nature and the temperature on the chloride transport through cementitious materials; Influence de la nature du liant et de la temperature sur le transport des chlorures dans les materiaux cimentaires

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Th.S

    2006-09-15

    The objective of this work is to document the effect of the temperature on the chloride diffusion through cement-based materials. The chloride diffusion coefficient, the penetration profiles and the chloride interactions with the solid phase were highlighted. The materials were CEM I and CEM V/A mortars and pastes. They were cured in wet room (21 {+-} 2 C, 90% relative humidity) for 1 month in the case of CEM I and 3 months in the case of CEM V before the experiments started. The temperature levels were 5, 21, 35 and 80 C.In addition, microstructure analyses were carried on using X-rays diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The experimental results were then used to continue to develop the numerical code, MsDiff, developed in our research group. A good agreement between the numerical concentration profiles and the experimental ones was found. (author)

  4. Animal Thermoregulation and the Operative Environmental (Equivalent) Temperature. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Process.

    Science.gov (United States)

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Thermoregulation is defined as the ability of an organism to modify its body temperature. This…

  5. The study on the neoclassical transport analysis using ECE measured temperature profiles in the LHD long pulse plasma

    International Nuclear Information System (INIS)

    Sasao, Hajime; Watanabe, Kiyomasa; Inagaki, Shigeru

    2000-01-01

    The purpose of this paper is to show the change of the neoclassical transport and the radial electric field in the long pulse LHD plasmas by using the experimental ECE data. The neoclassical heat flux, which the neo-classical theory predicts, changes due to the change of the radial electric field. The increase of H ions injected by Neutral Beam Injection (NBI) in He discharge produce effect on the electric field. There is the threshold of H quantity on the change of the electric field polarity. (author)

  6. Plataformas de colheita e colheita manual com trilha mecânica sobre a qualidade de sementes de arroz ( Oryza sativa, L. Harvest header and manual harvest with mechanical strip on rice ( Oryza sativa, L. seeds quality

    Directory of Open Access Journals (Sweden)

    Daniel Fernandez Franco

    1999-06-01

    Full Text Available Durante a colheita do arroz irrigado ocorrem perdas e danos físicos e fisiológicos às sementes. No final da década de oitenta, surgiram as plataformas recolhedoras, que retiram ou arrancam o grão ao invés de cortar a panícula, porém, pouco se conhece a respeito dos danos físicos e fisiológicos que este sistema de plataforma pode causar às sementes. Este trabalho teve por objetivo avaliar os danos mecânicos causados às sementes dos cultivares de arroz BR-IRGA 409 e BR-IRGA 410, por três formas de colheita: (a colheita manual e trilha mecânica; (b colheita com plataforma de corte; (c colheita com plataforma recolhedora. Quando a colheita foi mecânica, realizou-se a coleta das amostras diretamente no graneleiro. O delineamento experimental foi blocos ao acaso, com seis repetições. Os resultados demonstraram que as sementes de arroz irrigado dos cultivares estudados não apresentaram diferenças significativas em suas qualidades físicas e fisiológicas, quando colhidas com plataforma de corte e com a plataforma recolhedora. Estes dois métodos de colheita, porém, apresentaram danos significativamente maiores quando comparados à colheita manual e trilha mecânica.During irrigated rice harvesting occur losses and physical and phisiological seed damage. Late 80's, appeared the strippers headers that strip the grain, instead of cutting the spike. However, little is know about physical and phisiological seed damage by harvest header. The objective of this work was to evaluate the mechanical damage caused to BR-IRGA 409 and BR-IRGA 410 rice cultivars by three harvesting methods: (a manual harvesting and mechanical strip; (b cutterbar harvesting and; (c stripper header harvesting. Samples were collected directly in the grain tank when the harvest was mechanical. The experimental design was randomized blocks with six replications. Results demonstrated that the rice seeds of the studied variety didn't showed significant differences in

  7. The Effect of Post-Baking Temperature and Thickness of ZnO Electron Transport Layers for Efficient Planar Heterojunction Organometal-Trihalide Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Kun-Mu Lee

    2017-11-01

    Full Text Available Solution-processed zinc oxide (ZnO-based planar heterojunction perovskite photovoltaic device is reported in this study. The photovoltaic device benefits from the ZnO film as a high-conductivity and high-transparent electron transport layer. The optimal electron transport layer thickness and post-baking temperature for ZnO are systematically studied by scanning electron microscopy, photoluminescence and time-resolved photoluminescence spectroscopy, and X-ray diffraction. Optimized perovskite solar cells (PSCs show an open-circuit voltage, a short-circuit current density, and a fill factor of 1.04 V, 18.71 mA/cm2, and 70.2%, respectively. The highest power conversion efficiency of 13.66% was obtained when the device was prepared with a ZnO electron transport layer with a thickness of ~20 nm and when post-baking at 180 °C for 30 min. Finally, the stability of the highest performance ZnO-based PSCs without encapsulation was investigated in detail.

  8. Transport in microcrystalline silicon thin films deposited at low temperature by hot-wire chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bouree, Jean-Eric [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS UMR 7647, Ecole Polytechnique, 91128 Palaiseau (France)]. E-mail: jean-eric.bouree@polytechnique.edu; Jadkar, Sandesh R. [School of Energy Studies, Department of Physics, University of Pune, Pune 411 007 (India); Kasouit, Samir [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS UMR 7647, Ecole Polytechnique, 91128 Palaiseau (France); Vanderhaghen, Regis [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS UMR 7647, Ecole Polytechnique, 91128 Palaiseau (France)

    2006-04-20

    This work is focused on the determination of the variation of local mobility of charge carriers with thickness (< 1 {mu}m) for undoped microcrystalline silicon layers deposited by the hot-wire chemical vapor deposition technique. We observed that the temperature of the layers T {sub s} evolves with the deposition time, once the tungsten filament has been heated from room temperature to a fixed definite value. Thus, experiments have been realized by fixing the gas pressure (41 mTorr), the dilution of silane in hydrogen (50%), by setting the filament temperature (1600 deg. C) and letting the time run. An average substrate temperature T {sub s,av} has been defined, whose value depends on deposition time. As a result, the local mobility deduced from time-resolved microwave conductivity increases almost linearly with T {sub s,av} up to 193 deg. C, i.e. with thickness up to 400 nm corresponding approximately to the amorphous-microcrystalline transition and then increases sublinearly up to T {sub s,av} = 221 deg. C, i.e. a 900-nm-thick layer. These results, compatible with the highest AM1.5 efficiency (> 9%) reported so far for p-i-n {mu}c-Si:H solar cells realized at T {sub s} = 185 deg. C [S. Klein, F. Finger, R. Carius, T. Dylla, B. Rech, M. Grimm, L. Houben, M. Stutzmann, Thin Solid Films 430 (2003) 202], suggest that in the range of T {sub s,av} from 190 deg. C to 220 deg. C, hydrogen plays a dominant role in the HWCVD growth of {mu}c-Si:H films.

  9. SIMULATION OF TEMPERATURE AND TRANSPORT LOAD IMPACT ON FORMATION AND DEVELOPMENT OF CRACKS ON ASPHALT-CONCRETE ROAD SURFACES

    OpenAIRE

    I. S. Melnikova

    2012-01-01

    An analysis of statistical data has shown that about 60 % of all types of road surface destructions and damages in the Republic of Belarus are attributed to cracks (separate, frequent and cracks network). The process of cracks formation in the asphalt concrete pavement is rather complicated and it is affected by a number of factors. The most important and determining factors are character and value of traffic loads, temperature action, road pavement structure, properties of materials used for...

  10. Low-temperature magnetoresistance study of electrical transport in N- and B-doped ultrananocrystalline and nanocrystalline diamond films

    Czech Academy of Sciences Publication Activity Database

    Nesládek, M.; Tromson, D.; Bergonzo, P.; Hubík, Pavel; Mareš, Jiří J.; Krištofik, Jozef; Kindl, Dobroslav; Williams, O.A.; Gruen, D.

    2006-01-01

    Roč. 15, - (2006), s. 607-613 ISSN 0925-9635 R&D Projects: GA AV ČR(CZ) IAA1010404; GA ČR(CZ) GA202/06/0040 Institutional research plan: CEZ:AV0Z10100521 Keywords : U-NCD * NCD * doping * low-temperature doping * weak localisation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.935, year: 2006

  11. Time Trends and Predictors of Abnormal Postoperative Body Temperature in Infants Transported to the Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Hedwig Schroeck

    2016-01-01

    Full Text Available Background. Despite increasing adoption of active warming methods over the recent years, little is known about the effectiveness of these interventions on the occurrence of abnormal postoperative temperatures in sick infants. Methods. Preoperative and postoperative temperature readings, patient characteristics, and procedural factors of critically ill infants at a single institution were retrieved retrospectively from June 2006 until May 2014. The primary endpoints were the incidence and trend of postoperative hypothermia and hyperthermia on arrival at the intensive care units. Univariate and adjusted analyses were performed to identify factors independently associated with abnormal postoperative temperatures. Results. 2,350 cases were included. 82% were normothermic postoperatively, while hypothermia and hyperthermia each occurred in 9% of cases. During the study period, hypothermia decreased from 24% to 2% (p<0.0001 while hyperthermia remained unchanged (13% in 2006, 8% in 2014, p=0.357. Factors independently associated with hypothermia were higher ASA status (p=0.02, lack of intraoperative convective warming (p<0.001 and procedure date before 2010 (p<0.001. Independent associations for postoperative hyperthermia included lower body weight (p=0.01 and procedure date before 2010 (p<0.001. Conclusions. We report an increase in postoperative normothermia rates in critically ill infants from 2006 until 2014. Careful monitoring to avoid overcorrection and hyperthermia is recommended.

  12. Mathematical modelling of powder material motion and transportation in high-temperature flow core during plasma coatings application

    Science.gov (United States)

    Bogdanovich, V. I.; Giorbelidze, M. G.

    2018-03-01

    A problem of mathematical modelling of powder material motion and transportation in gas thermal flow core has been addressed. Undertaken studies indicate significant impact on dynamics of motion of sprayed particles of phenomenological law for drag coefficient and accounting momentum loss of a plasma jet upon acceleration of these particles and their diameter. It is determined that at great dispersion of spraying particles, they reach detail surface at different velocity and significant particles separation takes place at spraying spot. According to the results of mathematical modelling, requirements for admissible dispersion of diameters of particles used for spraying have been formulated. Research has also allowed reducing separation of particles at the spraying spot due to the selection of the method of powder feed to the anode channel of the plasma torch.

  13. The hotline in the grid. Higher temperatures with overhead lines can help to transport additional electricity; Der heisse Draht im Netz. Hoehere Temperaturen bei Freileitungen koennen helfen, Stromueberschuesse zu transportieren

    Energy Technology Data Exchange (ETDEWEB)

    Michels, Andreas; Friedrich, Uwe

    2016-11-01

    The electricity grid that has been used for decades reaches its limits when transporting increasing amounts of electricity over long distances. There are already limiting bottlenecks. One way to integrate more wind and solar power into the grid is provided by overhead lines with a higher maximum temperature. These can transport more electricity, enabling grid congestion to be avoided. One problem, though, is that metals expand more at high temperatures. As a result the line lengthens and sags more. However, special high-temperature conductors can provide a remedy here.

  14. Coiling Temperature Control Using Temperature Measurement Method for the Hot Rolled Strip in the Water Cooling Banks

    Science.gov (United States)

    Nakagawa, Shigemasa; Tachibana, Hisayoshi; Honda, Tatsuro; Uematsu, Chihiro

    In the hot strip mill, the quality of the strip greatly depends on the cooling process between the last stand in the finishing mill and the coilers. Therefore, it is important to carefully control the coiling temperature to regulate the mechanical properties of the strip. To realize high accuracy of coiling temperature, a new coiling temperature control using temperature measurement method for the hot rolled strip in the water cooling banks has been developed. The features of the new coiling temperature control are as follows: (i) New feedforward control adjusts ON/OFF swiching of cooling headers according to the strip temperature measured in the water cooling banks. (ii) New feedforward control is achieved by dynamic control function. This coiling temperature control has been in operation successfully since 2008 at Kashima Steel Works and improved the accuracy of coiling temperature of high strength steel considerably.

  15. Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

    Science.gov (United States)

    Romero-Trigueros, Cristina; Doval Miñarro, Marta; González Duperón, Esther; González Ferradás, Enrique

    2017-10-01

    Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID) is studied. Two reference gas mixtures (40 and 5 µg m-3 nominal concentration benzene in air) were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C) and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C). When measuring a concentration of 0.5 µg m-3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m-3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m-3), biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm-3 - corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

  16. Pengaruh Temperatur, Massa Zink, Substrat Dan Waktu Tahan Terhadap Struktur Dan Morfologi Zno Hasil Sintesis Dengan Metode Chemical Vapour Transport (CVT

    Directory of Open Access Journals (Sweden)

    Arisela Distyawan

    2013-09-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Material Zink Oksida (ZnO telah berhasil disintesis menggunakan metode Chemical Vapour Transport dengan bahan dasar prekursor berupa serbuk Zn yang dipanaskan hingga mencapai temperatur uap dalam furnace horisontal. Adapun variasi yang diberikan dalam penelitian adalah berupa temperatur pemanasan (850, 900, dan 950oC, massa prekursor Zn (0,15, 0,25, dan 0,35g, lama waktu sputtering substrat (90 dan 180 detik, dan waktu tahan khusus untuk mengetahui initial growth ZnO (10, 20, 30, 40, 50, dan 60 menit. Pembentukan Zink Oksida (ZnO dikonfirmasi melalui data X-RD, dimana telah terbentuk material ZnO dengan struktur hexagonal wurtzite. Berdarsarkan data XRD juga diketahui ukuran kristal pada sampel sputtering 90 detik mengalami penurunan bersamaan penambahan massa Zn. Dari hasil pengamatan SEM didapatkan bahwa morfologi permukaan lapisan tipis ZnO terdiri dari berbagai macam bentuk berupa nanoparticle, nanowires, nanorods, dan nanotetrapod. Lapisan Zno paling tebal sebesar ±350 nm pada sampel 950oC-0,15g sputter 90 detik. Semakin tinggi temperatur operasi berdampak peningkatan ukuran partikel. Pengujian FTIR turut menguatkan terbentuknya lapisan tipis di permukaan substrat Alumina. Hal ini didasarkan terjadinya penyerapan vibrasi yang membentuk lekukan pada kisaran area 509 cm-1 dari masing-masing sampel.

  17. Multiband transport and nonmetallic low-temperature state of K0.50Na0.24Fe1.52Se2

    Science.gov (United States)

    Ryu, Hyejin; Wolff-Fabris, F.; Warren, J. B.; Uhlarz, M.; Wosnitza, J.; Petrovic, C.

    2015-03-01

    We report evidence for multiband transport and an insulating low-temperature normal state in superconducting K0.50Na0.24Fe1.52Se2 with Tc ~ 20 K. The temperature-dependent upper critical field Hc2 is well described by a two-band model. After the superconductivity is suppressed by applying pulsed magnetic field at low temperature, the normal-state resistance is found to increase logarithmically as T --> 0. This is similar as for high-Tc copper oxides and granular superconductors, suggesting that the superconductor-insulator transition is related to intrinsic nanoscale phase separation. Work at Brookhaven is supported by the U.S. DOE under Contract No. DE-AC02-98CH10886 and in part by the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the U.S. DOE, Office for Basic Energy Science (C.P.). We acknowledge the support of the HLD at HZDR, member of the European Magnet Field Laboratory (EMFL). C.P. acknowledges support by the Alexander von Humboldt Foundation.

  18. Single step synthesis of ZnS quantum dots and their microstructure characterization and electrical transport below room temperature

    Science.gov (United States)

    Mukherjee, P. S.; Patra, S.; Chakraborty, G.; Pradhan, S. K.; Meikap, A. K.

    2016-09-01

    Low dimensional cubic phase ZnS quantum dots (QDs) are formed by mechanical alloying the stoichiometric mixture of Zn and S powders at room temperature. During milling process the primary mixed phase ZnS is formed at about 3.5 h of milling and strain less single phase (cubic) ZnS QDs are formed with ∼4.5 nm in size after 20 h of milling. Detailed microstructure study has been done by both Rietveld analysis of x-ray diffraction pattern and high resolution transmission electron microscope images. Dc resistivity decreases with increasing temperature which can be explained by three-dimensional hopping conduction mechanisms. Observed negative magnetoconductivity has been analyzed by wave function shrinkage model. Alternating current conductivity can be described by the correlated barrier hopping conduction mechanism. Analysis of complex impedance indicates that the grain boundary resistance is found to be dominating over the grain resistance. Relaxation behavior has been explained by the analysis of the electric modulus.

  19. SIMULATION OF TEMPERATURE AND TRANSPORT LOAD IMPACT ON FORMATION AND DEVELOPMENT OF CRACKS ON ASPHALT-CONCRETE ROAD SURFACES

    Directory of Open Access Journals (Sweden)

    I. S. Melnikova

    2012-01-01

    Full Text Available An analysis of statistical data has shown that about 60 % of all types of road surface destructions and damages in the Republic of Belarus are attributed to cracks (separate, frequent and cracks network. The process of cracks formation in the asphalt concrete pavement is rather complicated and it is affected by a number of factors. The most important and determining factors are character and value of traffic loads, temperature action, road pavement structure, properties of materials used for its layers. Some regularities of the cracks formation and development in the asphalt-concrete layers of the pavement have been established on the basis of the physical and mathematical modeling. Application of a finite  element  method for  calculations  has made it possible to determine  numerical values of compressive and tensile stresses arising due to temperature action and traffic load, deflection of road pavement constructive layers. The paper contains recommendations for a road pavement design and repair of asphalt-concrete pavements which have been made on the basis of the obtained data analysis.

  20. Evolution of Late Pliocene heat transport to high latitudes: Centennial-scale d18O and Mg/Ca-based temperature records from ODP Site 984 (Bjorn Drift).

    Science.gov (United States)

    Bartoli, G.; Sarnthein, M.; Weinelt, M.; Lea, D.; Erlenkeuser, H.

    2003-04-01

    A general increase in surface water salinity and deep ventilation in the Carribean after 4.2 Ma suggests that the final closure of the Panama Isthmus may have led to an increased heat transport to the northern high latitudes (Haug &Tiedemann, 1998). In turn, this enhanced transport may have provided additional moisture for the built-up of the Greenland ice sheet, as reflected by a sudden increase in ice rafting in the northern North Atlantic after 2.7 Ma (Jansen et al. 2000). To test this hypothesis, we compare sea surface and deep-water temperature records at ODP Site 984. Sediments at this site monitor the surface water inflow to the Greenland Sea. In particular, we focus on two time windows i) 3.1 - 3.4 Ma, prior to, and ii) 2.6 - 2.9 Ma, subsequent to the onset of Quaternary-style glaciation. Major objectives are to search for precursor signals for the major climatic change about 2.74 Ma ago and to trace back short-term Dansgaard-Oescher climate instability, in particular, whether it is a feature specific of Late Pleistocene scenarios with the presence of large continental ice sheets. Multicentennial-scale sea surface temperature records based on Mg/Ca and d18O data of the planktonic foraminifer Globigerina bulloides (ODP Site 984) are employed to trace variations in the strength of the Irminger Current. First results suggest that glacial-to-interglacial amplitudes only reached 2 C (8-10 C) in the older interval and increased to 5 C (8-13 C) during the younger time window and thus indeed confirm an enhanced transport of warm water to high latitudes after the final closure of Panama. In contrast, the d18O amplitudes of 1per mil (1.8-2.8 per mil) remain constant over both time windows, either reflecting a parallel increase in salinity transport and/or a significant waxing of ice volume along with the closure.

  1. Effect of room temperature transport vials on DNA quality and phylogenetic composition of faecal microbiota of elderly adults and infants.

    Science.gov (United States)

    Hill, Cian J; Brown, Jillian R M; Lynch, Denise B; Jeffery, Ian B; Ryan, C Anthony; Ross, R Paul; Stanton, Catherine; O'Toole, Paul W

    2016-05-10

    Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults. Use of the storage vials increased the quality of extracted bacterial DNA by reduction of DNA shearing. When infant and elderly datasets were examined separately, no differences in microbiota composition were observed due to storage. When the two datasets were combined, there was a difference according to a Wilcoxon test in the relative proportions of Faecalibacterium, Sporobacter, Clostridium XVIII, and Clostridium XlVa after 1 week's storage compared to immediately extracted samples. After 2 weeks' storage, Bacteroides abundance was also significantly different, showing an apparent increase from week 1 to week 2. The microbiota composition of infant samples was more affected than that of elderly samples by storage, with significantly higher Spearman distances between paired freshly extracted and stored samples (p < 0.001). When the microbiota profiles were analysed at the operational taxonomic unit (OTU) level, three infant datasets in the study did not cluster together, while only one elderly dataset did not. The lower microbiota diversity of the infant gut microbiota compared to the elderly gut microbiota (p < 0.001) means that any alteration in the infant datasets has a proportionally larger effect. The commercial storage vials appear

  2. Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

    Directory of Open Access Journals (Sweden)

    C. Romero-Trigueros

    2017-10-01

    Full Text Available Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID is studied. Two reference gas mixtures (40 and 5 µg m−3 nominal concentration benzene in air were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C. When measuring a concentration of 0.5 µg m−3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m−3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m−3, biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm−3 – corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

  3. Streamflow, sediment-transport, and water-temperature characteristics of the three small watersheds in the Alsea River basin, Oregon

    Science.gov (United States)

    Harris, David Dell; Williams, Robert Charles

    1971-01-01

    Data collected during the prelogging period 1959-65 indicate an average annual runoff for Needle Branch and Deer and Flynn Creeks of 74.2, 75.1, and 77.7 inches, respectively. The measured precipitation at Flynn Creek of 92.9 inches was 5 inches less than at either Needle Branch or Deer Creek. Unit flood runoff during the prelogging period was found to be lowest on Flynn Creek and highest on Needle Branch. On Needle Branch, there appear to be two distinct low-flow patterns, one for a saturated and one for an unsaturated soil condition. The average annual sediment yield was highest on Flynn Creek, 321 tons per square mile, and lowest on Needle Branch, 166 tons per square mile. Maximum water temperatures were 62?F on Flynn Creek and 61?F on Needle Branch and Deer Creek.

  4. Effect of the Temperature, External Magnetic Field, and Transport Current on Electrical Properties, Vortex Structure Evolution Processes, and Phase Transitions in Subsystems of Superconducting Grains and "Weak Links" of Granular Two-Level High-Temperature Superconductor YBa2Cu3O7-δ

    Science.gov (United States)

    Derevyanko, V. V.; Sukhareva, T. V.; Finkel', V. A.

    2018-03-01

    The temperature dependences of the resistivity of granular high-temperature superconductor YBa2Cu3O7-δ ρ( T) are measured at various transverse external magnetic fields 0 ≤ H ext ≤ 100 Oe in the temperature range from the resistivity onset temperature T ρ = 0 to the superconducting transition critical temperature T c at the transport current density from 50 to 2000 mA/cm2. The effect of the external magnetic field and transport current density on the kinetics of phase transitions in both subsystems of granular two-level HTSC ( T = T c2J, T c1g, T c ) is determined. The feasibility of the topological phase transition, i.e., the Berezinsky-Kosterlitz-Thouless transition, in the Josephson medium at T c2J < T BKT < T c1g "in transport current" is established, and its feasibility conditions are studied.

  5. Temperature and impurity transport studies of heated tokamak plasmas by means of a collisional-radiative model of x-ray emission from Mo30+ to Mo39+

    International Nuclear Information System (INIS)

    Pacella, D.; Fournier, K. B.; Zerbini, M.; Finkenthal, M.; Mattioli, M.; May, M. J.; Goldstein, W. H.

    2000-01-01

    This work presents and interprets, by means of detailed atomic calculations, observations of L-shell (n=3→n=2) transitions in highly ionized molybdenum, the main intrinsic heavy impurity in the Frascati tokamak upgrade plasmas. These hot plasmas were obtained by additional electron cyclotron resonance heating (ECRH), at the frequency of 140 Ghz, during the current ramp-up phase of the discharge. Injecting 400 kW on axis and 800 kW slightly off axis, the peak central electron temperature reached 8.0 and 7.0 keV, respectively, for a time much longer than the ionization equilibrium time of the molybdenum ions. X-ray emissions from rarely observed high charge states, Mo 30+ to Mo 39+ , have been studied with moderate spectral resolution (λ/Δλ∼150) and a time resolution of 5 ms. A sophisticated collisional-radiative model for the study of molybdenum ions in plasmas with electron temperature in the range 4-20 keV is presented. The sensitivity of the x-ray emission to the temperature and to impurity transport processes is discussed. This model has been then used to investigate two different plasma scenarios. In the first regime the ECRH heating occurs on axis during the current ramp up phase, when the magnetic shear is evolving from negative to zero up to the half radius. The spectrum is well reproduced with the molybdenum ions in coronal equilibrium and with a central impurity peaking. In the second regime, at the beginning of the current flat top when magnetic shear is monotonic and sawtoothing activity is appearing, the lowest charge states (Mo 33+ to Mo 30+ ), populated off axis, are affected by anomalous transport and the total molybdenum profile is found to be flat up to the half radius. We conclude with the presentation of ''synthetic spectra'' computed for even higher temperature plasmas that are expected in future experiments with higher ECRH power input. (c) 2000 The American Physical Society

  6. Low temperature transport and thermodynamic properties of the Zintl compound Yb11AlSb9: A new Kondo lattice semiconductor

    International Nuclear Information System (INIS)

    Magnavita, E.T.; Rettori, C.; Osorio-Guillén, J.M.; Ferreira, F.F.; Mendonça-Ferreira, L.; Avila, M.A.; Ribeiro, R.A.

    2016-01-01

    A thorough transport and thermodynamic investigation of flux-grown single crystals of the ternary Zintl phase Yb 11 AlSb 9 , combined with first-principles density functional theory calculations, shows that this compound is a metal above T ≈ 100 K and a semiconductor with small hybridization gap at low-T. The general behavior resembles those of Kondo lattice semiconductors, although some of the measured properties are strongly sample dependent, as often seen in hybridized f-electron materials. We thus suggest that Yb 11 AlSb 9 can be considered as a new Yb-based Kondo lattice semiconductor joining the family of strongly correlated electron systems. - Highlights: • First characterization at low temperatures of Yb 11 AlSb 9 . • Yb 11 AlSb 9 has a small, field dependent hybridization gap at low-T. • Yb 11 AlSb 9 can be considered as a new Kondo lattice semiconductor.

  7. Ratchetting behavior of primary heat transport (PHT) piping material SA-333 carbon steel subjected to cyclic loads at room temperature

    International Nuclear Information System (INIS)

    Kulkarni, S.; Desai, Y.M.; Kant, T.; Reddy, G.R.; Gupta, C.; Chakravarthy, J.K.

    2004-01-01

    Ratchetting behavior of SA-333 Gr. 6 carbon steel used as primary heat transport (PHT) piping material has been investigated with three constitutive models proposed by Armstrong-Frederick, Chaboche and Ohno-Wang involving different hardening rules. Performance of the above mentioned models have been evaluated for a broad set of uniaxial and biaxial loading histories. The uniaxial ratchetting simulations have been performed for a range of stress ratios (R) by imposing different stress amplitudes and mean stress conditions. Numerical simulations indicated significant ratchetting and opening of hysteresis loop for negative stress ratio with constant mean stress. Application of cyclic stress without mean stress (R = -1.0) has been observed to produce negligible ratchet-strain accumulation in the material. Simulation under the biaxial stress condition was based on modeling of an internally pressurized thin walled pipe subjected to cyclic bending load. Numerical results have been validated with the experiments as per simulation conditions. All three models have been found to predict the observed accumulation of circumferential strain with increasing number of cycles. However, the Armstrong Frederick (A-F) model was found to be inadequate in simulating the ratchetting response for both uniaxial as well as biaxial loading cases. The A-F model actually over-predicted the ratchetting strain in comparison with the experimental strain values. On the other hand, results obtained with the Chaboche and the Ohno-Wang models for both the uniaxial as well as biaxial loading histories have been observed to closely simulate the experimental results. The Ohno-Wang model resulted in better simulation for the presents sets of experimental results in comparison with the Chaboche model. It can be concluded that the Ohno-Wang model suited well compared to the Chaboche model for above sets of uniaxial and biaxial loading histories. (authors)

  8. A novel gel-based method for self-collection and ambient temperature postal transport of urine for PCR detection of Chlamydia trachomatis.

    Science.gov (United States)

    Bialasiewicz, S; Whiley, D M; Buhrer-Skinner, M; Bautista, C; Barker, K; Aitken, S; Gordon, R; Muller, R; Lambert, S B; Debattista, J; Nissen, M D; Sloots, T P

    2009-04-01

    The aim of this study was to develop a novel urine transport method to be used in self-collection-based screening for Chlamydia trachomatis. The method needed to be suitable for C trachomatis PCR detection, be economical and suitable for transport by standard envelope mailing. An anhydrous gel composed of super-absorbent polymer and buffering agent was used to desiccate urine into a dry granulous state, which could subsequently be reconstituted upon arrival at a laboratory. DNA was then extracted from the reconstituted solution using the Roche MagNA Pure protocol for the detection of C trachomatis by PCR. Collections of urine specimens from three populations with widely differing chlamydia prevalence (100%,n = 56; 47%, n = 70; 3%, n = 97) were used. We determined the gel method's impact on C trachomatis PCR sensitivity and specificity using neat and gel-processed urine specimens. An equine herpes virus PCR was used to test for assay inhibition. Overall, the sensitivity of the gel-based method ranged from 94.6-100% compared with neat urine, with a specificity of 100%. No PCR inhibition or decrease in analytical sensitivity was observed using the gel-processed extracts. The gel-based method was found to be suitable for the detection of C trachomatis by PCR. In addition, its ease of use, effectiveness at ambient temperature and low cost makes it well-suited for self-collection kits used in population-based C trachomatis screening, particularly for geographically and socially isolated individuals.

  9. Electrical transport and temperature coefficient of resistance in polycrystalline La{sub 0.7−x}Ag{sub x}Ca{sub 0.3}MnO{sub 3} pellets: Analysis in terms of a phase coexistence transport model and phase separation model

    Energy Technology Data Exchange (ETDEWEB)

    Phong, P.T., E-mail: ptphong.nh@khanhhoa.edu.vn [Department of Advanced Materials Chemistry, Dongguk University, 707 Suckjang-dong, Gyeongju-Si, Gyeonbuk 780-714 (Korea, Republic of); Nha Trang Pedagogic College, 01 Nguyen Chanh Street, Nha Trang, Khanh Hoa (Viet Nam); Nguyen, L.H. [Nha Trang Pedagogic College, 01 Nguyen Chanh Street, Nha Trang, Khanh Hoa (Viet Nam); Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Ha Noi (Viet Nam); Manh, D.H.; Phuc, N.X. [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Ha Noi (Viet Nam); Lee, I.-J. [Department of Advanced Materials Chemistry, Dongguk University, 707 Suckjang-dong, Gyeongju-Si, Gyeonbuk 780-714 (Korea, Republic of)

    2013-09-15

    The temperature dependent resistivity and temperature coefficient of resistance of Ag doped La{sub 0.7−x}Ag{sub x}Ca{sub 0.3}MnO{sub 3} polycrystalline pellets (x=0, 0.05, 0.10, 0.15, and 0.20) are investigated. Ag substitution enhances the conductivity of this system. The Curie temperature also increases from 260 to 283 K with increasing Ag content. Using phase-coexistence transport model and phase separation model, we calculated the resistivity as a function of temperature and the temperature coefficient of resistivity (TCR) behavior. Comparing the calculated maximum TCR, we found that it is related to activation energy, transition temperature, and disorder in doped manganites. The relationship between the proposed TCR behavior and the transport parameters can suggest conditions improving TCR{sub max} of doped manganites for the use of the bolometric infrared detectors.

  10. Room-Temperature and Solution-Processable Cu-Doped Nickel Oxide Nanoparticles for Efficient Hole-Transport Layers of Flexible Large-Area Perovskite Solar Cells.

    Science.gov (United States)

    He, Qiqi; Yao, Kai; Wang, Xiaofeng; Xia, Xuefeng; Leng, Shifeng; Li, Fan

    2017-12-06

    Flexible perovskite solar cells (PSCs) using plastic substrates have become one of the most attractive points in the field of thin-film solar cells. Low-temperature and solution-processable nanoparticles (NPs) enable the fabrication of semiconductor thin films in a simple and low-cost approach to function as charge-selective layers in flexible PSCs. Here, we synthesized phase-pure p-type Cu-doped NiO x NPs with good electrical properties, which can be processed to smooth, pinhole-free, and efficient hole transport layers (HTLs) with large-area uniformity over a wide range of film thickness using a room-temperature solution-processing technique. Such a high-quality inorganic HTL allows for the fabrication of flexible PSCs with an active area >1 cm 2 , which have a power conversion efficiency over 15.01% without hysteresis. Moreover, the Cu/NiO x NP-based flexible devices also demonstrate excellent air stability and mechanical stability compared to their counterpart fabricated on the pristine NiO x films. This work will contribute to the evolution of upscaling flexible PSCs with a simple fabrication process and high device performances.

  11. Use of electrical imaging and distributed temperature sensing methods to characterize surface water–groundwater exchange regulating uranium transport at the Hanford 300 Area, Washington

    Science.gov (United States)

    Slater, Lee D.; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Mwakanyamale, Kisa; Versteeg, Roelof J.; Ward, Andy; Strickland, Christopher; Johnson, Carole D.; Lane, John W.

    2010-01-01

    We explored the use of continuous waterborne electrical imaging (CWEI), in conjunction with fiber‐optic distributed temperature sensor (FO‐DTS) monitoring, to improve the conceptual model for uranium transport within the Columbia River corridor at the Hanford 300 Area, Washington. We first inverted resistivity and induced polarization CWEI data sets for distributions of electrical resistivity and polarizability, from which the spatial complexity of the primary hydrogeologic units was reconstructed. Variations in the depth to the interface between the overlying coarse‐grained, high‐permeability Hanford Formation and the underlying finer‐grained, less permeable Ringold Formation, an important contact that limits vertical migration of contaminants, were resolved along ∼3 km of the river corridor centered on the 300 Area. Polarizability images were translated into lithologic images using established relationships between polarizability and surface area normalized to pore volume (Spor). The FO‐DTS data recorded along 1.5 km of cable with a 1 m spatial resolution and 5 min sampling interval revealed subreaches showing (1) temperature anomalies (relatively warm in winter and cool in summer) and (2) a strong correlation between temperature and river stage (negative in winter and positive in summer), both indicative of reaches of enhanced surface water–groundwater exchange. The FO‐DTS data sets confirm the hydrologic significance of the variability identified in the CWEI and reveal a pattern of highly focused exchange, concentrated at springs where the Hanford Formation is thickest. Our findings illustrate how the combination of CWEI and FO‐DTS technologies can characterize surface water–groundwater exchange in a complex, coupled river‐aquifer system.

  12. Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble

    Science.gov (United States)

    Carmelo, J. M. P.; Prosen, T.

    2017-01-01

    Whether in the thermodynamic limit, vanishing magnetic field h → 0, and nonzero temperature the spin stiffness of the spin-1/2 XXX Heisenberg chain is finite or vanishes within the grand-canonical ensemble remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we provide an upper bound on the stiffness and show that within that ensemble it vanishes for h → 0 in the thermodynamic limit of chain length L → ∞, at high temperatures T → ∞. Our approach uses a representation in terms of the L physical spins 1/2. For all configurations that generate the exact spin-S energy and momentum eigenstates such a configuration involves a number 2S of unpaired spins 1/2 in multiplet configurations and L - 2 S spins 1/2 that are paired within Msp = L / 2 - S spin-singlet pairs. The Bethe-ansatz strings of length n = 1 and n > 1 describe a single unbound spin-singlet pair and a configuration within which n pairs are bound, respectively. In the case of n > 1 pairs this holds both for ideal and deformed strings associated with n complex rapidities with the same real part. The use of such a spin 1/2 representation provides useful physical information on the problem under investigation in contrast to often less controllable numerical studies. Our results provide strong evidence for the absence of ballistic transport in the spin-1/2 XXX Heisenberg chain in the thermodynamic limit, for high temperatures T → ∞, vanishing magnetic field h → 0 and within the grand-canonical ensemble.

  13. Low temperature transport anomaly in Cr substituted (La{sub 0.67}Sr{sub 0.33})MnO{sub 3} manganites

    Energy Technology Data Exchange (ETDEWEB)

    Tank, Tejas M., E-mail: tejas.physics2020@gmail.com [Solid State Physics Laboratory, Department of Physics, Barkatullah University, Bhopal-462 026 (India); Shelke, Vilas [Solid State Physics Laboratory, Department of Physics, Barkatullah University, Bhopal-462 026 (India); Das, Sarmistha; Rana, D.S. [Department of Physics, Indian Institute of Scientific Education and Research, Bhopal-462 023 (India); Thaker, C.M. [M.V.M. Science and Home Science College, Rajkot-360 005 (India); Samatham, S.S.; Ganesan, V. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore-452 001 (India); Sanyal, S.P. [Solid State Physics Laboratory, Department of Physics, Barkatullah University, Bhopal-462 026 (India)

    2017-06-15

    Highlights: • The effect of Cr substitution at the Mn-site of La{sub 0.67}Sr{sub 0.33}MnO{sub 3} has been studied. • Electrical and magnetic behaviors correlate with various theoretical models. • First time the low temperature transport anomaly has been explained in terms of e-e scattering phenomenon. • This study shows that FM interaction among Cr{sup 3+} and Mn{sup 3+} is like to the traditional Mn{sup 3+}-O{sup 2−}-Mn{sup 4+} process. - Abstract: The structural, electrical, and magnetic properties of La{sub 0.67}Sr{sub 0.33}Mn{sub 1−x}Cr{sub x}O{sub 3} (0 ≤ x ≤ 0.10) manganites have been studied by substitution of antiferromagnetic trivalent Cr ion at Mn-site. Systematic efforts have been carried out to understand the electrical resistivity behavior in the ferromagnetic metallic and paramagnetic semi-conducting phases of Cr substituted La{sub 0.67}Sr{sub 0.33}Mn{sub 1−x}Cr{sub x}O{sub 3} manganites. Polycrystalline samples show a resistivity minimum at a temperature (T{sub min}) of <40 K in the ferromagnetic metallic phase. T{sub min} shifts to higher temperatures on application of magnetic fields. The appearance of this resistivity minimum was analyzed by fittings the data according to the model that considers e-e scattering caused by enhanced Coulombic interactions. The electrical resistivity data has been best fitted in the metallic and semiconducting regime using various models. Present results suggest that intrinsic magnetic inhomogeneity like Cr{sup 3+} ions in these strongly electron-correlated manganite systems is originating due to the existence of the ferromagnetic interactions.

  14. Structural features and high-temperature transport in SrFe0.7Mo0.3O3-δ

    Science.gov (United States)

    Merkulov, O. V.; Markov, A. A.; Patrakeev, M. V.; Leonidov, I. A.; Shalaeva, E. V.; Tyutyunnik, A. P.; Kozhevnikov, V. L.

    2018-02-01

    The complex oxide SrFe0.7Mo0.3O3-δ was obtained by combustion of the organometallic precursor in air followed by annealing in an argon flow at 1350 °C, and characterized with the help of X-ray and electron diffraction methods. Oxygen nonstoichiometry and electrical conductivity data were collected in the oxygen partial pressure range from 10-19 to 0.5 atm at temperatures 750-950 °C. The as-prepared single phase oxide SrFe0.7Mo0.3O3-δ with the cubic double perovskite structure (SG Fm3m) is shown to undergo a structural transition to the tetragonal double perovskite phase (SG I4mmm) in the result of reducing treatment at pO2 = 10-12 atm and 950 °C. The ordered phases are characterized by a strong anti-site disordering of iron and molybdenum and nearly zero long-range ordering parameter. The maximal concentration of n-type carriers is about four times larger than of p-type carriers in the studied limits of oxygen pressure and temperature. The mobility of p-type carriers is found to vary within 0.02-0.03 cm2 V-1 s-1 with the migration energy of about 0.4 eV, while the n-type mobility being approximately twice higher does not practically depend on temperature. Such features as good electrical conductivity, which can rise up to 40 S cm-1 in reducing conditions and a considerable amount of oxygen vacancies favorable for fast oxygen ion transport are beneficial for application of SrFe0.7Mo0.3O3-δ as anode material in SOFCs and oxygen membrane for hydrogen generation by a water splitting.

  15. Enhancing the Performance of Quantum Dot Light-Emitting Diodes Using Room-Temperature-Processed Ga-Doped ZnO Nanoparticles as the Electron Transport Layer

    KAUST Repository

    Cao, Sheng

    2017-04-19

    Colloidal ZnO nanoparticle (NP) films are recognized as efficient electron transport layers (ETLs) for quantum dot light-emitting diodes (QD-LEDs) with good stability and high efficiency. However, because of the inherently high work function of such films, spontaneous charge transfer occurs at the QD/ZnO interface in such a QD-LED, thus leading to reduced performance. Here, to improve the QD-LED performance, we prepared Ga-doped ZnO NPs with low work functions and tailored band structures via a room-temperature (RT) solution process without the use of bulky organic ligands. We found that the charge transfer at the interface between the CdSe/ZnS QDs and the doped ZnO NPs was significantly weakened because of the incorporated Ga dopants. Remarkably, the as-assembled QD-LEDs, with Ga-doped ZnO NPs as the ETLs, exhibited superior luminances of up to 44 000 cd/m2 and efficiencies of up to 15 cd/A, placing them among the most efficient red-light QD-LEDs ever reported. This discovery provides a new strategy for fabricating high-performance QD-LEDs by using RT-processed Ga-doped ZnO NPs as the ETLs, which could be generalized to improve the efficiency of other optoelectronic devices.

  16. Low temperature transport and thermodynamic properties of the Zintl compound Yb{sub 11}AlSb{sub 9}: A new Kondo lattice semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Magnavita, E.T. [CCNH, Universidade Federal do ABC (UFABC), Santo André, SP, 09210-580 (Brazil); Rettori, C. [CCNH, Universidade Federal do ABC (UFABC), Santo André, SP, 09210-580 (Brazil); Instituto de Física “Gleb Wataghin”, UNICAMP, Campinas, SP, 13083-970 (Brazil); Osorio-Guillén, J.M. [Instituto de Física, Universidad de Antioquia UdeA, Calle 70 No 52-21, Medellín (Colombia); Ferreira, F.F.; Mendonça-Ferreira, L.; Avila, M.A.; Ribeiro, R.A. [CCNH, Universidade Federal do ABC (UFABC), Santo André, SP, 09210-580 (Brazil)

    2016-06-05

    A thorough transport and thermodynamic investigation of flux-grown single crystals of the ternary Zintl phase Yb{sub 11} AlSb{sub 9}, combined with first-principles density functional theory calculations, shows that this compound is a metal above T ≈ 100 K and a semiconductor with small hybridization gap at low-T. The general behavior resembles those of Kondo lattice semiconductors, although some of the measured properties are strongly sample dependent, as often seen in hybridized f-electron materials. We thus suggest that Yb{sub 11} AlSb{sub 9} can be considered as a new Yb-based Kondo lattice semiconductor joining the family of strongly correlated electron systems. - Highlights: • First characterization at low temperatures of Yb{sub 11}AlSb{sub 9}. • Yb{sub 11}AlSb{sub 9} has a small, field dependent hybridization gap at low-T. • Yb{sub 11}AlSb{sub 9} can be considered as a new Kondo lattice semiconductor.

  17. Quench behavior of Sr{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2}/Ag tapes with AC and DC transport currents at different temperature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi [Key Laboratory of Applied Superconductivity, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Institute of Science, Information Engineering University, Zhengzhou 450001 (China); Zhang, Guomin, E-mail: gmzhang@mail.iee.ac.cn [Key Laboratory of Applied Superconductivity, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Hua [Institute of Science, Information Engineering University, Zhengzhou 450001 (China); Li, Zhenming; Liu, Wei [China Electric Power Research Institute, Beijing 100192 (China); Jing, Liwei [Key Laboratory of Applied Superconductivity, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yu, Hui; Liu, Guole [Key Laboratory of Applied Superconductivity, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China)

    2016-09-15

    Highlights: • Quench behavior of Sr{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2}/ Ag tape with AC transport current was reported for the first time. • The measurement are performed as a function of different temperature (20 K–30 K), transport current (AC and DC) and operating frequency (50 Hz–250 Hz). • The study is concentrated on the research of quench development, and the discussions of NZPV and MQE values. - Abstract: In applications, superconducting wires may carry AC or DC transport current. Thus, it is important to understand the behavior of normal zone propagation in conductors and magnets under different current conditions in order to develop an effective quench protection system. In this paper, quench behavior of Ag sheathed Sr{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2} (Sr-122 in the family of iron-based superconductor) tapes with AC and DC transport current is reported. The measurements are performed as a function of different temperature (20 K–30 K), varying transport current and operating frequency (50 Hz–250 Hz). The focus of the research is the minimum quench energy (MQE), the normal zone propagation velocity (NZPV) and the comparison of the related results with AC and DC transport current.

  18. An integrated model of tritium transport and corrosion in Fluoride Salt-Cooled High-Temperature Reactors (FHRs) – Part I: Theory and benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Stempien, John D., E-mail: john.stempien@inl.gov; Ballinger, Ronald G., E-mail: hvymet@mit.edu; Forsberg, Charles W., E-mail: cforsber@mit.edu

    2016-12-15

    Highlights: • A model was developed for use with FHRs and benchmarked with experimental data. • Model results match results of tritium diffusion experiments. • Corrosion simulations show reasonable agreement with molten salt loop experiments. • This is the only existing model of tritium transport and corrosion in FHRs. • Model enables proposing and evaluating tritium control options in FHRs. - Abstract: The Fluoride Salt-Cooled High-Temperature Reactor (FHR) is a pebble bed nuclear reactor concept cooled by a liquid fluoride salt known as “flibe” ({sup 7}LiF-BeF{sub 2}). A model of TRITium Diffusion EvolutioN and Transport (TRIDENT) was developed for use with FHRs and benchmarked with experimental data. TRIDENT is the first model to integrate the effects of tritium production in the salt via neutron transmutation, with the effects of the chemical redox potential, tritium mass transfer, tritium diffusion through pipe walls, tritium uptake by graphite, selective chromium attack by tritium fluoride, and corrosion product mass transfer. While data from a forced-convection polythermal loop of molten salt containing tritium did not exist for comparison, TRIDENT calculations were compared to data from static salt diffusion tests in flibe and flinak (0.465LiF-0.115NaF-0.42KF) salts. In each case, TRIDENT matched the transient and steady-state behavior of these tritium diffusion experiments. The corrosion model in TRIDENT was compared against the natural convection flow-loop experiments at the Oak Ridge National Laboratory (ORNL) from the 1960s and early 1970s which used Molten Salt Reactor Experiment (MSRE) fuel-salt containing UF{sub 4}. Despite the lack of data required by TRIDENT for modeling the loops, some reasonable results were obtained. The TRIDENT corrosion rates follow the experimentally observed dependence on the square root of the product of the chromium solid-state diffusion coefficient with time. Additionally the TRIDENT model predicts mass

  19. Characteristics of the oil transport network in the South of Mexico

    Science.gov (United States)

    Juárez, R.; Fernández, I. Y.; Guzmán, L.

    2017-01-01

    We present a study of some organizational properties of the oil transport network of the Mexican oil company (PEMEX) in a region of the State of Tabasco. Particularly, the generalized centrality and the distribution of connectivities are calculated in order to evaluate some aspects of the structure of the network. We find that the connectivities (k) are characterized by a degree distribution which follows a power-law function of the form, P(k)~k -λ, with λ = 2.6. Moreover, our procedure permits to evalute the importance of lines (ducts) and nodes, which can be wells, production headers, separation batteries and petrochemical complexes.

  20. Electronic transport measurements in the electron-doped high-temperature superconductor Praseodymium(2-x) Cerium(x) Copper (II) oxide(4+-delta)

    Science.gov (United States)

    Bach, Paul Leonard

    2011-12-01

    This thesis is composed of four major parts centered around the electron-doped superconductor Pr2-xCexCuO4+/-delta: angular magnetoresistance studies of antiferromagnetism, doping effects of oxygenation, Tc enhancement by the creation of superlattices, and comparison of high-temperature resistivity with the pnictides. The first part focuses on transport measurements of the magnetism in Pr2-xCexCuO4+/-delta and La 2-xCexCuO4+/-delta. It was found that the thermal evolution of the angular dependence of magnetoresistance in Pr 2-xCexCuO4+/-delta can be used to determine the Neel temperature in that material. This angular magnetoresistance technique was also applied to La2-xCexCuO4+/-delta ; evidence for antiferromagnetism in this system was observed as well. This section additionally develops angular magnetoresistance as a useful probe in other cuprate projects here described. The second part investigates over-oxygenated and irradiated Pr2-x CexCuO4+/-delta, in under- and optimal dopings. Resistivity, Hall effect, and angular magnetoresistance measurements show oxygen both doping and disordering the system, in agreement with over-doped films. The evolution of both the Hall effect and angular magnetoresistance shows that over-oxygenation results in significant changes in the number of charge carriers, regardless of the increase in scattering incurred. Additionally, this study indicates that annealing primarily removes apical oxygen, rather than other proposed behaviors. The third part studies multi-layer films of Pr2-xCex CuO4+/-delta and La2-xCexCuO 4+/-delta. These superlattices exhibit a significant Tc enhancement over component layers' T cs. Interface effects are excluded as a source of this Tc increase based upon critical current measurments. The Tc enhancement is found to be due to charge redistribution. Based on Hall and angular magnetoresistance measurements, the result of this redistribution is slightly net-under-doped films. The fourth part uses Pr2-xCexCuO4

  1. Cold priming drives the sub-cellular antioxidant systems to protect photosynthetic electron transport against subsequent low temperature stress in winter wheat

    DEFF Research Database (Denmark)

    Li, Xiangnan; Cai, Jian; Liu, Fulai

    2014-01-01

    Low temperature seriously depresses the growth of wheat through inhibition of photosynthesis, while earlier cold priming may enhance the tolerance of plants to subsequent low temperature stress. Here, winter wheat plants were firstly cold primed (5.2°C lower temperature than the ambient temperatu...

  2. Compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2 as substitutes for SF6 to reduce global warming potential

    Science.gov (United States)

    Zhong, Linlin; Rong, Mingzhe; Wang, Xiaohua; Wu, Junhui; Han, Guiquan; Han, Guohui; Lu, Yanhui; Yang, Aijun; Wu, Yi

    2017-07-01

    C5F10O has recently been found to be a very promising alternative to SF6. This paper is devoted to the investigation of compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2. Firstly, the partition functions and enthalpies of formation for a few molecules (CxFy and CxFyO) which are likely to exist in the mixtures, are calculated based on the G4(MP2) theory. The isomers of the above molecules are selected according to their Gibbs energy. The compositions of C5F10O-CO2-O2 mixtures are then determined using the minimization of the Gibbs free energy. Next, the thermodynamic properties (mass density, specific enthalpy, and specific heat) are derived from the previously calculated compositions. Lastly, the transport coefficients (electrical conductivity, viscosity, and thermal conductivity) are calculated based on Chapman-Enskog method. It is found that, as an arc quenching gas, C5F10O could not recombine into itself with the temperature decreasing down to room temperature after the arc extinction. Besides, the key species at room temperature are always CF4, CO2, and C4F6 if graphite is not considered. When taken into account, graphite will replace C4F6 as one of the dominate particles. The mixing of CO2 with C5F10O plasma significantly affects the thermodynamic properties (e.g. vanishing and/or shifting of the peaks in specific heat) and transport coefficients (e.g. reducing viscosity and changing the number of peaks in thermal conductivity), while the addition of O2 with C5F10O-CO2 mixtures has no remarkable influence on both thermodynamic and transport properties.

  3. A cost effective model for appropriate administration of red cell units and salvaging un-transfused red cell units by using temperature sensitive indicators for blood component transportation in a hospital setting

    Directory of Open Access Journals (Sweden)

    Aseem K Tiwari

    2015-01-01

    Full Text Available Background: A rule called "30-min rule" defines that red cell unit cannot be used if it has been out of blood bank refrigerator for over 30 min. This rule is useful to guide initiation of transfusion, but is inadequate for deciding whether to reuse or discard units received-back at blood transfusion services (BTS. A simple cost-effective temperature-sensitive indicator was evaluated to decide upon reuse (cold chain was uninterrupted or discard (where cold chain was interrupted in a simulation exercise. Materials and Methods: Temperature-sensitive indicators TH-F™ that irreversibly changed color from white to red demonstrated that heat excursion has occurred and the cumulative temperature has exceeded 10°C for over 30 min, were used in outdated red cells for simulating units, which are not used and received-back. These units were also tagged with a standard temperature monitoring device, which was a re-usable credit card sized device, which would log the actual time and temperature. In few units percent hemolysis was also calculated. Results: Statistically insignificant elevation in average temperature was noted in 102 simulated units at the time of return to BTS (Δ 0.04°C, despite the fact that these units were in the transport box for over 4 h. The average supernatant hemoglobin in these units was 0.24%, much below the prescribed threshold. Conclusion: Transportation of blood in controlled conditions with temperature-sensitive indicator is a cost-effective model to save blood, a precious human resource.

  4. GHRSST Level 2P Western Pacific Regional Skin Sea Surface Temperature from the Multifunctional Transport Satellite 1R (MTSAT-1R) (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multi-functional Transport Satellites (MTSAT) are a series of geostationary weather satellites operated by the Japan Meteorological Agency (JMA). MTSAT carries an...

  5. GHRSST Level 2P Western Pacific Regional Skin Sea Surface Temperature from the Multifunctional Transport Satellite 2 (MTSAT-2) (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multi-functional Transport Satellites (MTSAT) are a series of geostationary weather satellites operated by the Japan Meteorological Agency (JMA). MTSAT carries an...

  6. The behaviour of transport from the fission products caesium and strontium in coated particles for high temperature reactors under irradiation conditions

    International Nuclear Information System (INIS)

    Zoller, P.

    1976-07-01

    At first survey is given about existing knowledge of the behaviour of caesium and strontium fission product transport in coated particles. In order to describe the complicated fission product transport mechanisms under irradiation conditions a suitable calculating model (SLIPPER) is taken over and modified to the special problems of an irradiation experiment. Fundamentally, the fission product transport is represented by the two contributions of diffusion and recoil, at which the diffusion is described by effective diffusion coefficients. In difference of that the possibility of a two-phase-diffusion is examined for the Cs diffusion in the fuel kernel. The model application on measuring results from irradiation experiments of KFA-Juelich and Mol-Belgien allowed the explanation from the characteristic of fission product transport in coated particles under irradiation conditions and produced effective diffusion coefficients for the fission products Cs and Sr. (orig.) [de

  7. Electric field-induced hole transport in copper(i) thiocyanate (CuSCN) thin-films processed from solution at room temperature

    KAUST Repository

    Pattanasattayavong, Pichaya

    2013-01-01

    The optical, structural and charge transport properties of solution-processed films of copper(i) thiocyanate (CuSCN) are investigated in this work. As-processed CuSCN films of ∼20 nm in thickness are found to be nano-crystalline, highly transparent and exhibit intrinsic hole transporting characteristics with a maximum field-effect mobility in the range of 0.01-0.1 cm2 V-1 s-1. © 2013 The Royal Society of Chemistry.

  8. Transport properties of silver telluride in the solid and liquid states; Etude des proprietes de transport dans le tellurure d'argent Ag{sub 2}Te aux hautes temperatures a l'etat solide et a l'etat liquide

    Energy Technology Data Exchange (ETDEWEB)

    Pham, N.T. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-01-01

    Measurements of the electrical resistivity, Hall coefficient and thermoelectric power have been carried out for silver telluride over a large temperature range including both solid and liquid states. The analysis of the experimental data shows that in the solid state the transport properties are governed by an ambipolar process with an electron mobility much higher than the hole mobility ({mu}{sub n} = 10*{mu}{sub p}). It is found that the temperature dependence of the electron mobility can be represented by a T{sup -3} law. Deviations from the stoichiometric composition Ag{sub 2}Te have been studied. For all specimens, melting is accompanied by discontinuous variations in the transport properties. Above the melting point, the magnitude of the measured parameters and their temperature dependence show that liquid silver telluride behaves as a semiconductor. The contribution of Ag{sup +} ions to transport phenomena is suggested to account for the behaviour of the electrical properties. Experimental data have been analysed in terms of conventional theories. (author) [French] Les mesures de la resistivite electrique, du coefficient de Hall et du pouvoir thermoelectrique ont ete effectuees sur le tellurure d'argent dans un large domaine de temperature couvrant l'etat solide et l'etat liquide. L'analyse des resultats experimentaux obtenus a l'etat solide montre que les proprietes de transport sont gouvernees par le processus ambipolaire avec une mobilite des electrons beaucoup plus grande que celle des trous ({mu}{sub n} 10*{mu}{sub p}). On trouve que la mobilite des electrons varie avec la temperature suivant la loi T{sup -3}. Les ecarts de la composition stoechiometrique Ag{sub 2}Te ont ete etudies. Pour tous les echantillons, la fusion est caracterisee par des variations discontinues des proprietes de transport. Au dessus du point de fusion, la grandeur des parametres mesures ainsi que leur variation avec la temperature montrent que le

  9. Development of CANDU 6 Primary Heat Transport System Modeling Program

    International Nuclear Information System (INIS)

    Seo, Hyung-beom; Kim, Sung-min; Park, Joong-woo; Kim, Kwang-su; Ko, Dae-hack; Han, Bong-seob

    2007-01-01

    NUCIRC is a steady-state thermal-hydraulic code used for design and performance analyses of CANDU Heat Transport System. The code is used to build PHT model in Wolsong NPP and to calculate channel flow distribution. Wolsong NPP has to calculate channel flow distribution and quality of coolant at the ROH header after every outage by OPP (Operating Policy and Principal). PHT modeling work is time consuming which need a lot of operation experience and specialty. It is very difficult to build PHT model as plant operator in two weeks which is obligate for plant operation after every outage. That is why Wolsong NPP develop NUMODEL (NUcirc MODELing) with many-years experience and a know-how of using NUCIRC code. NUMODEL is computer program which is used to create PHT model based on utilizing NUCIRC code

  10. Low-temperature magnetothermal transport investigation of a Ni-based superconductor BaNi2As2: evidence for fully gapped superconductivity.

    Science.gov (United States)

    Kurita, N; Ronning, F; Tokiwa, Y; Bauer, E D; Subedi, A; Singh, D J; Thompson, J D; Movshovich, R

    2009-04-10

    We have performed low-temperature specific heat and thermal conductivity measurements of the Ni-based superconductor BaNi2As2 (T{c}=0.7 K) in a magnetic field. In a zero field, thermal conductivity shows T-linear behavior in the normal state and exhibits a BCS-like exponential decrease below T{c}. The field dependence of the residual thermal conductivity extrapolated to zero temperature is indicative of a fully gapped superconductor. This conclusion is supported by the analysis of the specific heat data, which are well fit by the BCS temperature dependence from T{c} down to the lowest temperature of 0.1 K.

  11. Conserved histidine of metal transporter AtNRAMP1 is crucial for optimal plant growth under manganese deficiency at chilling temperatures

    NARCIS (Netherlands)

    Ihnatowicz, A.; Siwinska, J.; Meharg, A.A.; Carey, M.; Koornneef, M.; Reymond, M.

    2014-01-01

    Manganese (Mn) is an essential nutrient required for plant growth, in particular in the process of photosynthesis. Plant performance is influenced by various environmental stresses including contrasting temperatures, light or nutrient deficiencies. The molecular responses of plants exposed to such

  12. Use of Temperature, Humidity, and Slaughter Condemnation Data to Predict Increases in Transport Losses in Three Classes of Swine and Resulting Foregone Revenue

    Directory of Open Access Journals (Sweden)

    Erik Peterson

    2017-05-01

    Full Text Available The United States Department of Agriculture (USDA Animal and Plant Health Inspection Service (APHIS conducts weekly surveillance of slaughter condemnation rates to provide early warning for emerging diseases and to monitor health trends in swine. Swine deaths in-transit are an animal welfare concern and represent lost revenue for the swine industry. This retrospective observational study used ambient temperature and humidity data from weather stations near United States slaughter plants collected from 2010 to 2015 to predict the incidence and risk of death among swine in-transit and just prior to slaughter. The risk of death for market swine at a heat index (HI, which combines the effects of temperature and humidity, indicating moderately hot weather conditions between 85 and 92°F was 1.37 times greater than that of the baseline temperature range of 54–79°F. The risk of death for cull sows at an HI between 85 and 92°F was 1.93 times greater than that of average temperatures ranging from 54 to 79°F. Roaster swine (weigh < 220 lbs and often used for whole carcass roasting, however, had 0.80 times the risk when the HI was 85–92°F compared to a baseline temperature of 54–79°F. The risk of death for roaster swine at a minimum temperature between 40 and 50°F was 1.21 times greater than that of average temperatures ranging from 54 to 79°F. The risk of death for market swine at a minimum temperature range of 40–50°F was 0.97 times that of average temperatures ranging from 54 to 79°F. And for cull sows, the risk of death at a minimum temperature range of 40–50°F was 0.81 times the risk at the average temperature ranging from 54 to 79°F. Across the study period, cumulative foregone revenue, or revenue not realized due to swine condemnations, for all swine was $18.6 million and $4.3 million for cold temperatures and high HI ranges above the baseline, respectively. Marginal foregone revenue per hog in hotter months is higher due

  13. Anomaly Detection of IP Header Threats

    OpenAIRE

    S.H.C. Haris, Ghossoon M. Waleed, R.B. Ahmad & M.A.H.A. Ghani

    2011-01-01

    Threats have become a big problem since the past few years as computerviruses are widely recognized as a significant computer threat. However, the roleof Information Technology security must be revisit again since it is too often. ITsecurity managers find themselves in the hopeless situation of trying to uphold amaximum of security as requested from management. At the same time they areconsidered an obstacle in the way of developing and introducing newapplications into business and government...

  14. Experimental study of thermodynamic and transport properties of binary mixtures of poly(ethylene glycol diacrylate and alcohols at different temperatures

    Directory of Open Access Journals (Sweden)

    Vuksanović Jelena M.

    2015-01-01

    Full Text Available Experimental density r, refractive index nD and viscosity h data of three binary systems of poly(ethylene glycol diacrylate (PEGDA + ethanol, + 1-propanol, and + 1-butanol were measured at eight temperatures from (288.15 to 323.15 K, with temperature step of 5 K, and at atmospheric pressure. The experimental data were correlated as a function of PEGDA mole fraction and temperature. Densities and refractive indices of the investigated mixtures could be fitted well with exponential function vs. composition, including temperature dependence of parameters, while in the case of viscosities polynomial function fits well over a mixture’s composition. In the case of temperature correlation, all three properties (ρ, lnη and nD exhibit linear trend. The viscosity modeling was performed using four models: UNIFAC-VISCO, ASOG-VISCO, Mc-Allister and Teja-Rice. For application of UNIFAC-VISCO model interaction parameters of following groups were determined: CH2=CH/CH3, CH2=CH/CH2, CH2=CH/OH, CH2=CH/CH2O and CH2=CH/COO. Also, in the same way binary interaction parameters used in ASOG-VISCO of the following groups were determined: CH2=CH/CH2, CH2=CH/OH, CH2=CH/CH2O and CH2=CH/COO. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  15. Thermal ionization and plasma state of high temperature vapor of UO2, Cs, and Na: Effect on the heat and radiation transport properties of the vapor phase

    International Nuclear Information System (INIS)

    Karow, H.U.

    1979-01-01

    The paper deals with the question how far the thermophysical state and the convective and radiative heat transport properties of vaporized reactor core materials are affected by the thermal ionization existing in the actual vapor state. The materials under consideration here are: nuclear oxide fuel (UO 2 ), Na (as the LMFBR coolant material), and Cs (alkaline fission product, partly retained in the fuel of the core zone). (orig./RW) [de

  16. InAlN/InGaN/GaN double heterostructure with improved carrier confinement and high-temperature transport performance grown by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Zhao, Yi; Xue, Jun Shuai; Zhang, Jin Cheng; Zhou, Xiao Wei; Zhang, Ya Chao; Hao, Yue

    2015-01-01

    A nearly lattice-matched InAlN/InGaN/GaN double heterostructure (DH) and traditional InAlN/GaN single heterostructure (SH) were grown by metal–organic chemical vapor deposition. The InN mole fraction of InGaN channel was deduced by XRD and photoluminescence. The electrical properties were characterized by capacitance-voltage and temperature-dependent Hall measurements. Both results revealed that the InAlN/InGaN/GaN DH possessed superior carrier confinement over traditional InAlN/GaN SH owing to the back barrier formed at the InGaN/GaN interface, which prevents the spilling over of carriers and thus remarkably improves the transport performance at high temperature. Furthermore, a thin InGaN layer was preferable for carrier channel applications to a thick one. (paper)

  17. Transport properties of YBa2Cu3O7-x thin films formed by plasma-enhanced metalorganic chemical vapor deposition at reduced temperatures

    Science.gov (United States)

    Zhao, J.; Norris, P.; Peterson, T. L.; Maartense, I.; Chern, C. S.; Lu, P.; Kear, B.; Li, Y. Q.; Gallois, B.

    1992-04-01

    YBa2Cu3O7-x superconducting thin films with a high transition temperature of 90.7 K and a high critical current density of 4.1×106 A/cm2 at 77.7 K and 0 T were prepared by a plasma-enhanced metalorganic chemical vapor deposition process. The films with sharp transition and critical current density ≳2×106 A/cm2 were also formed in situ on LaAlO3 at a substrate temperature as low as 640 °C. Magnetic susceptibility measurements of the as deposited films show sharp superconducting transition temperatures with narrow widths <0.3 K.

  18. Temperature dependence of DC transport characteristics for a two-dimensional electron gas in an undoped Si/SiGe heterostructure

    Science.gov (United States)

    Chou, Kuan-Yu; Hsu, Nai-Wen; Su, Yi-Hsin; Chou, Chung-Tao; Chiu, Po-Yuan; Chuang, Yen; Li, Jiun-Yun

    2018-02-01

    We investigate DC characteristics of a two-dimensional electron gas (2DEG) in an undoped Si/SiGe heterostructure and its temperature dependence. An insulated-gate field-effect transistor was fabricated, and transfer characteristics were measured at 4 K-300 K. At low temperatures (T tunneling from the buried channel to the surface channel. Finally, the drain current is saturated again at large gate biases due to parallel conduction of buried and surface channels. By increasing the temperature, an abrupt increase in threshold voltage is observed at T ˜ 45 K and it is speculated that negatively charged impurities at the Al2O3/Si interface are responsible for the threshold voltage shift. At T > 45 K, the current saturation and negative transconductance disappear and the device acts as a normal transistor.

  19. Impact of interannual variability (1979-1986) of transport and temperature on ozone as computed using a two-dimensional photochemical model

    Science.gov (United States)

    Jackman, Charles H.; Douglass, Anne R.; Chandra, Sushil; Stolarski, Richard S.; Rosenfield, Joan E.; Kaye, Jack A.

    1991-01-01

    Values of the monthly mean heating rates and the residual circulation characteristics were calculated using NMC data for temperature and the solar backscattered UV ozone for the period between 1979 and 1986. The results were used in a two-dimensional photochemical model in order to examine the effects of temperature and residual circulation on the interannual variability of ozone. It was found that the calculated total ozone was more sensitive to variations in interannual residual circulation than in the interannual temperature. The magnitude of the modeled ozone variability was found to be similar to the observed variability, but the observed and modeled year-to-year deviations were, for the most part, uncorrelated, due to the fact that the model did not account for most of the QBO forcing and for some of the observed tropospheric changes.

  20. Thermodynamic and transport properties of (1-Butanol + 1,4-Butanediol) at temperatures from (298.15 to 318.15) K

    International Nuclear Information System (INIS)

    Zorebski, Edward; Geppert-Rybczynska, Monika

    2010-01-01

    Densities and kinematic viscosities have been measured for (1-butanol + 1,4-butanediol) over the temperature range from (298.15 to 318.15) K. The speeds of sound within the temperature range from (293.15 to 318.15) K have been measured as well. Using these results and literature values of isobaric heat capacities, the molar volumes, isentropic and isothermal compressibility coefficients, molar isentropic and isothermal compressibilities, isochoric heat capacities as well as internal pressures were calculated. Also the corresponding excess and deviation values (excess molar volumes, excess isentropic and isothermal compressibility coefficients, excess molar isentropic and isothermal compressibilities, different defined deviation speed of sound and dynamic viscosity deviations) were calculated. The excess values are negative over the whole concentration and temperature range. The excess and deviation values are expressed by Redlich-Kister polynomials and discussed in terms of the variations of the structure of the system caused by the participation of the two different alcohol molecules in the dynamic intermolecular association process through hydrogen bonding at various temperatures. The predictive abilities of Grunberg-Nissan and McAllister equations for viscosities of mixtures have also been examined.

  1. Kinetics and transport at AMTEC electrodes. II - Temperature dependence of the interfacial impedance of Na(g)/porous Mo/Na-Beta-double prime alumina

    Science.gov (United States)

    Williams, R. M.; Jeffries-Nakamura, B.; Underwood, M. L.; Bankston, C. P.; Kummer, J. T.

    1990-01-01

    The exchange current, transfer coefficient, mass-transport parameters, and electrode capacitance at the Na(g)/porous Mo/Na-Beta-double prime alumina solid electrolyte (BASE) phase boundary have been evaluated from 740 to 1220 K. The transfer coefficient exhibits a value close to 0.5 and the exchange current is dominated by collision frequency, with no significant activation energy. Since the porous Mp-electrode adopts a fairly regular microstructure on the BASE surface, the magnitude of the exchange current of mature electrodes directly depends on the actual contact zone of the porous metal film with the BASE ceramic, and decreases slightly as grain growth occurs. The exchange currents and the mass-transport parameters derived for very porous, thin Mo electrodes indicate that the charge-transfer reaction occurs at a small fraction of the interface. High-frequency limiting capacitance and resistance values due to the interface show potential dependence and a value on the order of 1 F/sq m and 0.1-1.0 Ohm-sq cm.

  2. Simultaneous fermentation of glucose and xylose at elevated temperatures co-produces ethanol and xylitol through overexpression of a xylose-specific transporter in engineered Kluyveromyces marxianus.

    Science.gov (United States)

    Zhang, Biao; Zhang, Jia; Wang, Dongmei; Han, Ruixiang; Ding, Rui; Gao, Xiaolian; Sun, Lianhong; Hong, Jiong

    2016-09-01

    Engineered Kluyveromyces marxianus strains were constructed through over-expression of various transporters for simultaneous co-fermentation of glucose and xylose. The glucose was converted into ethanol, whereas xylose was converted into xylitol which has higher value than ethanol. Over-expressing xylose-specific transporter ScGAL2-N376F mutant enabled yeast to co-ferment glucose and xylose and the co-fermentation ability was obviously improved through increasing ScGAL2-N376F expression. The production of glycerol was blocked and acetate production was reduced by disrupting gene KmGPD1. The obtained K. marxianus YZJ119 utilized 120g/L glucose and 60g/L xylose simultaneously and produced 50.10g/L ethanol and 55.88g/L xylitol at 42°C. The yield of xylitol from consumed xylose was over 98% (0.99g/g). Through simultaneous saccharification and co-fermentation at 42°C, YZJ119 produced a maximal concentration of 44.58g/L ethanol and 32.03g/L xylitol or 29.82g/L ethanol and 31.72g/L xylitol, respectively, from detoxified or non-detoxified diluted acid pretreated corncob. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Temperature Dependent Electrical Transport in Al/Poly(4-vinyl phenol/p-GaAs Metal-Oxide-Semiconductor by Sol-Gel Spin Coating Method

    Directory of Open Access Journals (Sweden)

    Şadan Özden

    2016-01-01

    Full Text Available Deposition of poly(4-vinyl phenol insulator layer is carried out by applying the spin coating technique onto p-type GaAs substrate so as to create Al/poly(4-vinyl phenol/p-GaAs metal-oxide-semiconductor (MOS structure. Temperature was set to 80–320 K while the current-voltage (I-V characteristics of the structure were examined in the study. Ideality factor (n and barrier height (ϕb values found in the experiment ranged from 3.13 and 0.616 eV (320 K to 11.56 and 0.147 eV (80 K. Comparing the thermionic field emission theory and thermionic emission theory, the temperature dependent ideality factor behavior displayed that thermionic field emission theory is more valid than the latter. The calculated tunneling energy was 96 meV.

  4. Crystal structure and high temperature transport properties of Yb-filled p-type skutterudites YbxCo2.5Fe1.5Sb12

    KAUST Repository

    Dong, Yongkwan

    2014-01-01

    Partially Yb-filled Fe substituted polycrystalline p-type skutterudites with nominal compositions YbxCo2.5Fe1.5Sb 12, with varying filler concentrations x, were synthesized by reacting the constituent elements and subsequent solid state annealing, followed by densification by hot-pressing. The compositions and filling fractions were confirmed with a combination of Rietveld refinement and elemental analysis. Their thermoelectric properties were evaluated from 300 to 800 K. The Seebeck coefficients for the specimens increase with increasing temperature and plateau at around 750 K. The thermal conductivity decreases with increasing Yb filling fraction, and bipolar conduction becomes evident and increases at elevated temperatures. A maximum ZT value of 0.8 was obtained at 750 K for Yb 0.47Co2.6Fe1.4Sb12. The thermoelectric properties and potential for further optimization are discussed in light of our results. © 2013 Elsevier Inc.

  5. Inorganic Lead Halide Perovskite Single Crystals: Phase-Selective Low-Temperature Growth, Carrier Transport Properties, and Self-Powered Photodetection

    KAUST Repository

    Saidaminov, Makhsud I.

    2016-12-06

    A rapid, low-temperature, and solution-based route is developed for growing large-sized cesium lead halide perovskite single crystals under ambient conditions. An ultralow minority carrier concentration was measured in CsPbBr3 (≈108 holes per cm3, much lower than in any other lead halide perovskite and crystalline silicon), which enables to realize self-powered photodetectors with a high ON/OFF ratio (105).

  6. The transport of a radio-active species by adsorption and diffusion through a porous medium in the presence of a temperature gradient

    International Nuclear Information System (INIS)

    Faircloth, R.L.; Thomas, R.B.

    1976-01-01

    A theoretical treatment is given of the migration of fission products through a porous medium in the presence of a temperature gradient. The system is simplified by considering the behaviour in an idealised single pore in which movement is occurring by a combination of gas phase and surface diffusion, the distribution between these modes of transfer being governed by the adsorption isotherm constant. The effect of carrier gas flow within the pore is also considered. (author)

  7. Rare-Earth Ions in Niobium-Based Devices as a Quantum Memory: Magneto-Optical Effects on Room Temperature Electrical Transport

    Science.gov (United States)

    2016-09-01

    TECHNICAL REPORT 3050 September 2016 Rare-Earth Ions in Niobium-based Devices as a Quantum Memory Magneto-Optical Effects on Room Temperature...Advanced Systems and Applied Sciences Division iii EXECUTIVE SUMMARY Rare-earth ions are useful for the implementation of quantum memory . In...the films and devices so they can properly designed and optimized for utility as quantum memory . We find that the magnetic field has a strong effect

  8. Ultralow-temperature heat transport in the quantum spin liquid candidate Ca10Cr7O28 with a bilayer kagome lattice

    Science.gov (United States)

    Ni, J. M.; Liu, Q. Y.; Yu, Y. J.; Cheng, E. J.; Huang, Y. Y.; Liu, Z. Y.; Wang, X. J.; Sui, Y.; Li, S. Y.

    2018-03-01

    Recently, a novel material with a bilayer kagome lattice Ca10Cr7O28 was proposed to be a gapless quantum spin liquid, due to the lack of long-range magnetic order and the observation of broad diffuse excitations. Here, we present the ultralow-temperature thermal conductivity measurements on single crystals of Ca10Cr7O28 to detect its low-lying magnetic excitations. At finite temperatures, with increasing magnetic fields, the thermal conductivity exhibits a clear dip around 6 T, which may correspond to a crossover in the magnetic ground state. At the zero-temperature limit, no residual linear term is found at any fields, indicating the absence of gapless itinerant fermionic excitations. Therefore, if the spinons do exist, they are either localized or gapped. In the gapped case, the fitting of our data gives a small gap, Δ ˜0.27 (2 ) K. These results put strong constraints on the theoretical description of the ground state in this quantum spin liquid candidate.

  9. Effect of transport temperature of ovaries on in vitro maturation of canine oocytes collected in different stages of the estrous cycle

    OpenAIRE

    Leda Maria Costa Pereira; Paulo Ricardo Oliveira Bersano; Maria Denise Lopes

    2015-01-01

    Foi avaliada a influencia do ciclo estral e temperatura de transporte de ovários na maturação in vitro de oócitos caninos. As cadelas foram categorizadas em dois grupos baseados no estagio do ciclo estral – anestro ou diestro. Um ovário por par coletado foi transportado em solução fisiológica 0,9% a 4°C enquanto o outro foi transportado a 37°C. Então, os ovários foram seccionados em PBS para a liberação dos complexos cumulus oocito (COCs). Um total de 345 COCs (n = 186 oocitos obtidos de cade...

  10. The coat protein of Alternanthera mosaic virus is the elicitor of a temperature-sensitive systemic necrosis in Nicotiana benthamiana, and interacts with a host boron transporter protein

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyoun-Sub, E-mail: hyounlim@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Nam, Jiryun, E-mail: jilyoon@naver.com [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Seo, Eun-Young, E-mail: sey22@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Nam, Moon, E-mail: moonlit51@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Vaira, Anna Maria, E-mail: a.vaira@ivv.cnr.it [Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, 10300 Baltimore Avenue B-010A, Beltsville, MD 20705 (United States); Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, Torino 10135 (Italy); Bae, Hanhong, E-mail: hanhongbae@ynu.ac.kr [School of Biotechnology, Yeungnam University, Geongsan 712-749 (Korea, Republic of); Jang, Chan-Yong, E-mail: sunbispirit@gmail.com [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Cheol Ho, E-mail: chlee1219@hanmail.net [Department of Chemical and Biological Engineering, Seokyoung University, Seoul 136-704 (Korea, Republic of); Kim, Hong Gi, E-mail: hgkim@cnu.ac.kr [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Roh, Mark, E-mail: marksroh@gmail.com [Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, 10300 Baltimore Avenue B-010A, Beltsville, MD 20705 (United States); Laboratory of Floriculture and Plant Physiology, School of Bio-Resource Science, Dankook University, Cheonan, Chungnam 330-714 (Korea, Republic of); Hammond, John, E-mail: john.hammond@ars.usda.gov [Floral and Nursery Plants Research Unit, US National Arboretum, USDA-ARS, 10300 Baltimore Avenue B-010A, Beltsville, MD 20705 (United States)

    2014-03-15

    Different isolates of Alternanthera mosaic virus (AltMV; Potexvirus), including four infectious clones derived from AltMV-SP, induce distinct systemic symptoms in Nicotiana benthamiana. Virus accumulation was enhanced at 15 °C compared to 25 °C; severe clone AltMV 3-7 induced systemic necrosis (SN) and plant death at 15 °C. No interaction with potexvirus resistance gene Rx was detected, although SN was ablated by silencing of SGT1, as for other cases of potexvirus-induced necrosis. Substitution of AltMV 3-7 coat protein (CP{sub SP}) with that from AltMV-Po (CP{sub Po}) eliminated SN at 15 °C, and ameliorated symptoms in Alternanthera dentata and soybean. Substitution of only two residues from CP{sub Po} [either MN(13,14)ID or LA(76,77)IS] efficiently ablated SN in N. benthamiana. CP{sub SP} but not CP{sub Po} interacted with Arabidopsis boron transporter protein AtBOR1 by yeast two-hybrid assay; N. benthamiana homolog NbBOR1 interacted more strongly with CP{sub SP} than CP{sub Po} in bimolecular fluorescence complementation, and may affect recognition of CP as an elicitor of SN. - Highlights: • Alternanthera mosaic virus CP is an elicitor of systemic necrosis in N. benthamiana. • Virus-induced systemic necrosis is enhanced at 15 °C compared to 25 °C. • Induction of systemic necrosis is dependent on as few as two CP amino acid residues. • These residues are at subunit interfaces within the same turn of the virion helix. • Inducer/non-inducer CPs interact differentially with a boron transporter protein.

  11. Hole-transporting transistors and circuits based on the transparent inorganic semiconductor copper(I) thiocyanate (CuSCN) processed from solution at room temperature

    KAUST Repository

    Pattanasattayavong, Pichaya

    2012-12-27

    The wide bandgap and highly transparent inorganic compound copper(I) thiocyanate (CuSCN) is used for the first time to fabricate p-type thin-film transistors processed from solution at room temperature. By combining CuSCN with the high-k relaxor ferroelectric polymeric dielectric P(VDF-TrFE-CFE), we demonstrate low-voltage transistors with hole mobilities on the order of 0.1 cm2 V-1 s-1. By integrating two CuSCN transistors, unipolar logic NOT gates are also demonstrated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Experimental constraints on transport

    International Nuclear Information System (INIS)

    Luce, T.C.; Petty, K.H.; Burrell, K.H.; Forest, C.B.; Gohil, P.; Groebner, R.J.; De Haas, J.C.M.; James, R.A.; Makowski, M.A.

    1994-12-01

    Characterization of the cross-field energy transport in magnetic confinement experiments in a manner applicable to the accurate assessment of future machine performance continues to be a challenging goal. Experimental results from the DIII-D tokamak in the areas of dimensionless scaling and non-diffusive transport represent progress toward this goal. Dimensionless scaling shows how beneficial the increase in machine size and magnetic field is for future devices. The experiments on DIII-D are the first to determine separately the electron and ion scaling with normalized gyroradius ρ * ; the electrons scale as expected from gyro-Bohm class theories, while the ions scale consistent with the Goldston empirical scaling. This result predicts an increase in transport relative to Bohm diffusion as ρ * decreases in future devices. The existence of distinct ρ * scalings for ions and electrons cautions against a physical interpretation of one-fluid or global analysis. The second class of experiments reported here are the first to demonstrate the existence of non-diffusive energy transport. Electron cyclotron heating was applied at the half radius; the electron temperature profile remains substantially peaked. Power balance analysis indicates that heat must flow in the direction of increasing temperature, which is inconsistent with purely diffusive transport. The dynamics of electron temperature perturbations indicate the presence in the heat flux of a term dependent on temperature rather than its gradient. These two observations strongly constrain the types of models which can be applied to cross-field heat transport

  13. Morphology and electronic transport of polycrystalline silicon films deposited by SiF sub 4 /H sub 2 at a substrate temperature of 200 deg. C

    CERN Document Server

    Hazra, S; Ray, S

    2002-01-01

    Undoped and phosphorous doped polycrystalline silicon (poly-Si) films were deposited using a SiF sub 4 /H sub 2 gas mixture at a substrate temperature of 200 deg. C by radio frequency plasma enhanced chemical vapor deposition (rf-PECVD). Fourier transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD) experiments reveal that the present poly-Si films are equivalent to the poly-Si films deposited at high temperature (>600 deg. C). XRD and scanning electron microscope observations show that the crystalline quality of slightly P-doped film is better compared to that of undoped poly-Si films. Phosphorus atom concentration in the slightly P-doped poly-Si film is 5.0x10 sup 1 sup 6 atoms/cm sup 3. Association of a few phosphorous atoms in the silicon matrix enhances crystallization as eutectic-forming metals do. Dark conductivity of slightly P-doped film is 4 orders of magnitude higher, although mobility-lifetime product (eta mu tau) is 2 orders of magnitude lower than that of undoped film. The presence o...

  14. Effect of transport temperature of ovaries on in vitro maturation of canine oocytes collected in different stages of the estrous cycle

    Directory of Open Access Journals (Sweden)

    Leda Maria Costa Pereira

    2015-06-01

    Full Text Available Foi avaliada a influencia do ciclo estral e temperatura de transporte de ovários na maturação in vitro de oócitos caninos. As cadelas foram categorizadas em dois grupos baseados no estagio do ciclo estral – anestro ou diestro. Um ovário por par coletado foi transportado em solução fisiológica 0,9% a 4°C enquanto o outro foi transportado a 37°C. Então, os ovários foram seccionados em PBS para a liberação dos complexos cumulus oocito (COCs. Um total de 345 COCs (n = 186 oocitos obtidos de cadelas em anestro e 159 em diestro foi cultivado em TCM 199 suplementado com HEPES, piruvato de sódio, cisteina, hormônio folículo estimulante (FSH, gonadotrofina coriônica humana (hCG, estrógeno (E2 e fator de crescimento epidermal (EGF. Apos 72h de maturação, os COCs foram desnudados, fixados e corados para avaliação da maturação nuclear. O teste de Fisher foi utilizado para avaliar as diferenças entre os grupos. O nível de significância adotado foi de 0,05. Os oócitos obtidos de cadelas em diestro transportados a 4°C apresentaram maior frequência de oócitos no estagio de metáfase II (21,1% que os mantidos na temperatura de 37°C (p < 0,01. De forma similar, houve maior frequência de oócitos nos estágios de metáfase II (11,2% nos ovários obtidos de cadelas em anestro e transportados a 4°C que nos ovários mantidos a 37°C (p < 0,05. Concluiu-se que a temperatura de transporte influencia os resultados de viabilidade oocitária canina e a maturação in vitro, independentemente do estagio reprodutivo da fêmea.

  15. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  16. Charge carrier transport in Cu(In,Ga)Se2 thin-film solar-cells studied by electron beam induced current and temperature and illumination dependent current voltage analysis

    International Nuclear Information System (INIS)

    Nichterwitz, Melanie

    2012-01-01

    This work contributes to the understanding of generation dependent charge-carrier transport properties in Cu(In,Ga)Se 2 (CIGSe)/ CdS/ ZnO solar cells and a consistent model for the electronic band diagram of the heterojunction region of the device is developed. Cross section electron-beam induced current (EBIC) and temperature and illumination dependent current voltage (IV) measurements are performed on CIGSe solar cells with varying absorber layer compositions and CdS thickness. For a better understanding of possibilities and limitations of EBIC measurements applied on CIGSe solar cells, detailed numerical simulations of cross section EBIC profiles for varying electron beam and solar cell parameters are performed and compared to profiles obtained from an analytical description. Especially the effects of high injection conditions are considered. Even though the collection function of the solar cell is not independent of the generation function of the electron beam, the local electron diffusion length in CIGSe can still be extracted. Grain specific values ranging from (480±70) nm to (2.3±0.2) μm are determined for a CuInSe 2 absorber layer and a value of (2.8±0.3) μm for CIGSe with a Ga-content of 0.3. There are several models discussed in literature to explain generation dependent charge carrier transport, all assuming a high acceptor density either located in the CIGSe layer close to the CIGSe/CdS interface (p + layer), within the CdS layer or at the CdS/ZnO interface. In all models, a change in charge carrier collection properties is caused by a generation dependent occupation probability of the acceptor type defect state and the resulting potential distribution throughout the device. Numerical simulations of EBIC and IV data are performed with parameters according to these models. The model that explains the experimental data best is that of a p + layer at the CIGSe/CdS interface and acceptor type defect states at the CdS/ZnO interface. The p + layer leads

  17. Chamber transport

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2001-01-01

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system

  18. CANDU fuel compression tests at elevated temperatures

    International Nuclear Information System (INIS)

    Koehn, E.; Chan, J.K.; Langman, V.J.; Hadaller, G.I.; Fortman, R.A.

    1995-01-01

    An inlet header large break loss of coolant accident (LOCA) in CANDU reactors with fuelling against flow can cause the fuel to shift in the channels with a consequent reactivity insertion. This results in an increased fuel power transient, and a potential increase in the mialyzed consequences for such events. As the reactor's age and the channel axial gaps increase, the magnitude of the predicted power u-dmient increases. A design solution to reduce the power transient is to limit the amount of fuel movement by reducing the channel axial gap. This solution was implemented into Ontario Hydro's Bruce B and Darlington reactors. A consequence of a reduced channel axial gap is the potential for the fuel column axial expansion to become constrained by the channel end components in large break LOCAs. This experimental program investigated the effects of pellet cracking and elevated sheath temperatures on the ability of the fuel elements, of the 37-element bundle design, to sustain axial loads. The unirradiated fuel elements tested were either in the as-received condition or with the U0 2 fuel pellets cracked in a mechanical process to simulate the effect of inufflation. The load deformation characteristics demonstrated that, for a given amount of axial compression. the loads sustainable by the elements at elevated sheath temperatures were low. As a result. excess axial expansion would be easily accommodated without further challenge to pressure tube integrity. (author)

  19. Oxygen transport and degradation properties of high-temperature membranes for CO{sub 2}-free power plants; Sauerstofftransport und Degradationsverhalten von Hochtemperaturmembranen fuer CO{sub 2}-freie Kraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Schlehuber, Dominic

    2010-07-01

    This thesis deals with membranes for oxygen separation from air for high temperature application in fossil power plants within the scope of the oxyfuel-process. Different perovskite membrane materials (ABO3-ae) were investigated concerning the oxygen transport and their chemical stability under operation condition. The association between oxygen transport properties and both the thermodynamic boundary conditions as well as the material properties (membrane thickness and surface properties) was studied. One possibility to achieve higher oxygen fluxes through the membrane is to reduce the thickness. In this case the influence of surface processes on the overall permeation becomes noteworthy. The effect of different membrane surface modifications on the permeation rate was investigated. For example it could be confirmed, that a porous layer on the membrane surface significantly increases the permeation flux due to the compensation of surface exchange limitations. Beyond that, degradation processes during the operation under power plant condition were investigated. Special attention was attached to the influence of degradation on the permeation flux during long term operation. Thereby kinetic demixing of the membrane material was observed. (orig.)

  20. The role of correlations in the determination of the transport properties of LaCl{sub 3} in high temperature molten eutectic LiCl-KCl

    Energy Technology Data Exchange (ETDEWEB)

    Samin, Adib; Wu, Evan; Zhang, Jinsuo [The Ohio State Univ., Columbus, OH (United States). Dept. of Mechanical and Aerospace Engineering

    2017-10-01

    It is important to develop an accurate assessment of fundamental data of lanthanides in high temperature molten salts to enable an efficient application of pyroprocessing. This requires a careful consideration of uncertainties in the reported results. In this study, cyclic voltammetry (CV) tests of LaCl{sub 3} in KCl-LiCl molten salt were conducted at low concentration levels in the molten salt at 723 K and at several scan rates. The CV signals were subsequently analyzed through the conventional CV analysis and using a BET-based model through a nonlinear least-squares fitting procedure. It was determined that the parameters of the model were strongly correlated and the support plane procedure was implemented to assign joint confidence intervals for the diffusivity of lanthanum. Accounting for the correlations led to a significant increase in the uncertainty of the reported diffusivity which led to better agreement with the literature. Accounting for the correlations may be important for higher concentration levels.

  1. Caracterização das publicações periódicas em fonoaudiologia e neurociências: estudo sobre os tipos e temas de artigos e visibilidade na área de linguagem Periodicals' profile in speech-language and hearing pathology and neurosciences: study on types and headers of the language area articles, and their visibility

    Directory of Open Access Journals (Sweden)

    Sandrelli Virginio de Vasconcelos

    2009-03-01

    Full Text Available TEMA: caracterização das publicações periódicas em Fonoaudiologia e Neurociências: estudo sobre os tipos e temas de artigos e visibilidade na área de linguagem. OBJETIVO: caracterizar as publicações periódicas em Fonoaudiologia estudando os artigos da área de Linguagem relacionados às Neurociências no período de 2002 a 2006. CONCLUSÃO: ficou evidente um aumento crescente de publicações em Linguagem e em Neurociências nos últimos cinco anos. Contudo, o número de publicações em determinados temas como a Dislexia, a Doença de Alzheimer e o Transtorno do Déficit de Atenção / Hiperatividade ainda mostra-se resumido.BACKGROUND: periodicals' profile in speechlanguage and hearing pathology and neurosciences: study on types and headers of the language articles, and their visibility. PURPOSE: to characterize periodicals in SpeechLanguage Pathology and Hearing, studying the articles of the Language's area related to Neurosciences in the period from 2002 to 2006. CONCLUSION: increasing publication in Language and Neurosciences in the last five years has been evident. However, number of publications in certain headers, such as dyslexia, Alzheimer's disease and AttentionDeficit/Hyperactivity Disorder are still abridged.

  2. Transport Coefficients of Fluids

    CERN Document Server

    Eu, Byung Chan

    2006-01-01

    Until recently the formal statistical mechanical approach offered no practicable method for computing the transport coefficients of liquids, and so most practitioners had to resort to empirical fitting formulas. This has now changed, as demonstrated in this innovative monograph. The author presents and applies new methods based on statistical mechanics for calculating the transport coefficients of simple and complex liquids over wide ranges of density and temperature. These molecular theories enable the transport coefficients to be calculated in terms of equilibrium thermodynamic properties, and the results are shown to account satisfactorily for experimental observations, including even the non-Newtonian behavior of fluids far from equilibrium.

  3. Undulator Transportation Test Results

    International Nuclear Information System (INIS)

    Wolf, Zachary

    2010-01-01

    A test was performed to determine whether transporting and handling the undulators makes any changes to their properties. This note documents the test. No significant changes to the test undulator were observed. After the LCLS undulators are tuned and fiducialized in the Magnetic Measurement Facility (MMF), they must be transported to storage buildings and transported to the tunnel. It has been established that the undulators are sensitive to temperature. We wish to know whether the undulators are also sensitive to the vibrations and shocks of transportation. To study this issue, we performed a test in which an undulator was measured in the MMF, transported to the tunnel, brought back to the MMF, and re-measured. This note documents the test and the results.

  4. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....

  5. Neurotransmitter transporters

    DEFF Research Database (Denmark)

    Gether, Ulrik; Andersen, Peter H; Larsson, Orla M

    2006-01-01

    The concentration of neurotransmitters in the extracellular space is tightly controlled by distinct classes of membrane transport proteins. This review focuses on the molecular function of two major classes of neurotransmitter transporter that are present in the cell membrane of neurons and....../or glial cells: the solute carrier (SLC)1 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of glutamate, and the SLC6 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of dopamine, 5-HT, norepinephrine, glycine and GABA....... Recent research has provided substantial insight into the structure and function of these transporters. In particular, the recent crystallizations of bacterial homologs are of the utmost importance, enabling the first reliable structural models of the mammalian neurotransmitter transporters...

  6. Artificial oxygen transport protein

    Science.gov (United States)

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  7. Transport properties of liquids

    International Nuclear Information System (INIS)

    Rajagopal, K.

    1976-07-01

    The transport coefficients, self diffusivity, dinamical viscosity,total viscosity (i.e., the first and second viscosity coefficient) and thermal conductivity, are calculated at several temperatures and saturation pressures for the Argon, Krypton and Xenon liquids, from the Mie otential and the hard sphere theory. (L.C.) [pt

  8. Paleoclassical electron heat transport

    International Nuclear Information System (INIS)

    Callen, J.D.

    2005-01-01

    Radial electron heat transport in low collisionality, magnetically-confined toroidal plasmas is shown to result from paleoclassical Coulomb collision processes (parallel electron heat conduction and magnetic field diffusion). In such plasmas the electron temperature equilibrates along magnetic field lines a long length L, which is the minimum of the electron collision length and a maximum effective half length of helical field lines. Thus, the diffusing field lines induce a radial electron heat diffusivity M ≅ L/(πR 0q ) ∼ 10 >> 1 times the magnetic field diffusivity η/μ 0 ≅ ν e (c/ω p ) 2 . The paleoclassical electron heat flux model provides interpretations for many features of 'anomalous' electron heat transport: magnitude and radial profile of electron heat diffusivity (in tokamaks, STs, and RFPs), Alcator scaling in high density plasmas, transport barriers around low order rational surfaces and near a separatrix, and a natural heat pinch (or minimum temperature gradient) heat flux form. (author)

  9. Temperature Data Evaluation

    International Nuclear Information System (INIS)

    Gillespie, David

    2003-01-01

    Groundwater temperature is sensitive to the competing processes of heat flow from below the advective transport of heat by groundwater flow. Because groundwater temperature is sensitive to conductive and advective processes, groundwater temperature may be utilized as a tracer to further constrain the uncertainty of predictions of advective radionuclide transport models constructed for the Nevada Test Site (NTS). Since heat transport, geochemical, and hydrologic models for a given area must all be consistent, uncertainty can be reduced by devaluing the weight of those models that do not match estimated heat flow. The objective of this study was to identify the quantity and quality of available heat flow data at the NTS. One-hundred-forty-five temperature logs from 63 boreholes were examined. Thirteen were found to have temperature profiles suitable for the determination of heat flow values from one or more intervals within the boreholes. If sufficient spatially distributed heat flow values are obtained, a heat transport model coupled to a hydrologic model may be used to reduce the uncertainty of a nonisothermal hydrologic model of the NTS

  10. Formation of indium-doped zinc oxide thin films using chemical spray techniques: The importance of acetic acid content in the aerosol solution and the substrate temperature for enhancing electrical transport

    International Nuclear Information System (INIS)

    Castaneda, L.; Garcia-Valenzuela, A.; Zironi, E.P.; Canetas-Ortega, J.; Terrones, M.; Maldonado, A.

    2006-01-01

    Indium-doped zinc oxide (ZnO:In) thin films were grown on glass substrates using the chemical spray technique. The effects of the acetic acid content in the starting solution (c AA ), as well as the substrate temperature (T S ), were studied. Our results demonstrate that when c AA is extremely low, the resistivity values of the zinc oxide (ZnO) thin films become relatively high (in the order of 4 x 10 -2 Ω cm). When the c AA is increased at a fixed temperature, the resistivity of the films decreases, reaching values as low as 4 x 10 -3 Ω cm for thin films deposited at 525 deg. C. The electron mobility could also increase to a maximum value of 10.5 cm 2 /(V s) for films deposited at 500 deg. C. We also observed an enhancement in the electrical transport properties of the films by varying T S ; the lowest resistivity values occurred in films deposited at T S between 475 and 525 deg. C. In addition, the relative intensity of the diffraction peaks associated with the crystallographic planes is strongly affected by the c AA concentration. X-ray diffraction studies reveal the polycrystalline nature of the films exhibiting a hexagonal wurtzite type, with a preferential orientation of the film depending on the acetic acid concentration. Film morphology was also affected by varying c AA , as grains with distinct geometrical shapes were observed. Finally, the optical transmittance of all these films was found to be higher than 85%

  11. Portable Body Temperature Conditioner

    Science.gov (United States)

    2014-12-01

    patients become hypothermic after severe injury due to environmental exposure during transport. These patients also have decreased thermoregulation due to...based on the load demand to conserve power consumption 4 Requires glycol solution to prevent H20 freezing at cold ambient temperatures 3. Product...three days. To encompass the range of the temperature to be used during the Patient Simulation testing (15oC – 40oC); cold (15oC), neutral (25oC

  12. Measurement of temperature fluctuations and anomalous transport ...

    Indian Academy of Sciences (India)

    (b) Displacement of plasma from the centre of the vacuum vessel; horizontal displacement ¡А ( ve means ... vacuum vessel) and the ion saturation current Б× drawn by the pair is obtained by measur- ing the voltage drop ... sheared E- xB rotation (plasma rotation) as observed in other machines [8]. The fluctuation induced ...

  13. Transport properties of cobalt at low temperatures

    DEFF Research Database (Denmark)

    Radharkishna, P.; Nielsen, Mourits

    1965-01-01

    Measurements are made of electrical resistivity, absolute thermoelectric power, and thermal conductivity of polycrystalline cobalt between 1.2 and 6 K; results are discussed on basis of inter-electronic scattering.......Measurements are made of electrical resistivity, absolute thermoelectric power, and thermal conductivity of polycrystalline cobalt between 1.2 and 6 K; results are discussed on basis of inter-electronic scattering....

  14. Molecular Dynamics study of transport properties (self-diffusion, shear viscosity, thermal conductivity) in CMAS liquids at elevated temperature and pressure: Relations between coordination statistics, activation energy and activation volume. (Invited)

    Science.gov (United States)

    Spera, F. J.; Martin, B.; Creamer, J. B.; Nevins, D.; Cutler, I.; Ghiorso, M. S.; Tikunoff, D.

    2010-12-01

    Empirical Potential Molecular Dynamics (EPMD) simulations have been carried out for molten MgSiO3, Mg2SiO4, CaMgSi2O6, CaAl2Si2O8 and 1-bar eutectic liquid in the binary system CaMgSi2O6-CaAl2Si2O8 using a Coulomb-Born-Mayer-van der Waals pair potential form and the potential parameters from Matsui (1996, GRL 23:395) for the system CaO-MgO-Al2O3-SiO2. Simulations were performed in the microcanonical ensemble (NEV) with 8000 atoms, a 1 fs time step, and simulation durations up to 2 ns. Computations were carried out every 500 K over a temperature range of 2500 - 5000 K along 10-20 isochores for each composition to insure good coverage in P-T space. During run T and P fluctuations, giving the uncertainty of state point coordinates was typically ± 30 K and ± 0.5 GPa, respectively. Coordination statistics are determined by counting nearest neighbor configurations up to a cutoff defined by the first minima of the pair correlation function. A complete set of coordination statistics was collected at each state point for each composition. At each state point self-diffusivity of each atom was determined from the Einstein relation between Mean Square Displacement and time. Shear viscosity was computed for a subset of state points using Green-Kubo linear response theory, by studying the autocorrelated regressions of spontaneous fluctuations of appropriate components of the stress tensor. Thermodynamic models (and EOS) for each liquid previously developed from these simulations based on combining the Rosenfeld-Tarazona (1998, Mol Phys 95:141) potential energy-temperature scaling law with the Universal EOS (1986, J Phys C, 19:L467) enable self-consistent computation of liquid sound speeds and isochoric heat capacity used to develop phonon thermal conductivity values at high T and P. Self-diffusivity, shear viscosity and phonon thermal conductivity values from the MD simulations vary systematically with composition, temperature and pressure. These systematic relations correlate

  15. Study of the iodine transport mechanisms in a nuclear accidental medium by high temperature mass spectrometry in the framework of the 'CHIP' (Iodine Chemistry in the reactor coolant system) program. I - Thermodynamics of CsOH vaporization; Etude des mecanismes de transport de l iode en milieu nucleaire accidentel par spectrometrie de masse haute temperature dans le cadre du programme CHIP (CHimie de l Iode dans le circuit Primaire). I - Thermodynamique de la vaporisation de CsOH

    Energy Technology Data Exchange (ETDEWEB)

    Roki, F.Z.; Ohnet, M.N.; Jacquemain, D. [IRSN, DPAM, SEREA, Laboratoire d Essais Analytiques, Centre de Cadarache, BP 3, 13115 St Paul-Lez- Durance Cedex, (France); Chatillon, C. [Laboratoire de Thermodynamique et Physico-Chimie Metallurgiques (associe au CNRS, UMR 5614), BP 75 - 38402 Saint Martin d Heres, (France)

    2006-07-01

    Iodine is one of the fission products which vaporizes in a complex chemical medium and can be transported under different gaseous forms in the PWR primary coolant system during a severe nuclear accident. The 'CHIP' analytical program has been implemented to study in a first time, the quaternary complex systems of the type Cs-I-O-H. In this system, the CsOH(l or s) vaporization is an important element. A study by high temperature mass spectrometry shows that the vapor species are the CsOH(g), its dimers Cs{sub 2}O{sub 2}H{sub 2}(g) and its trimers Cs{sub 3}O{sub 3}H{sub 3}(g). For this last specie, no thermodynamic determination has been done until today. The quantitative exploitation of the vapor pressures leads to the determination of the dimerization enthalpy reaction: (CsOH){sub 2}(g)=2 CsOH(g) {delta}H(average)(298.14 K)136.5 {+-} 3.85 kJ.mol{sup -1} (calculated with the third thermodynamic law). (O.M.)

  16. Temperature and leaf wax d

    NARCIS (Netherlands)

    Thomas, E.K.; Clemens, S.C.; Prell, W.L.; Herbert, T.D.; Huang, Y.S.; Liu, Z.; Sinninghe Damsté, J.S.; Sun, Y.; Wen, X.

    2014-01-01

    Orbital-scale precipitation isotope records can elucidate climate forcing mechanisms and provide benchmarks for climate model validation. The ability to differentiate the influence of temperature, seasonality, and vapor transport history on precipitation isotope proxies is critical to both

  17. Sediment Transport

    DEFF Research Database (Denmark)

    Liu, Zhou

    Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2...

  18. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... This analysis starts with a review of ocean transportation demand and supply including projections of ship capacity demand and world shipbuilding capacity under various economic and political assumptions...

  19. Charge Injection and Transport in Organic Nanofibers

    DEFF Research Database (Denmark)

    Kjelstrup-Hansen, Jakob; Bøggild, Peter; Rubahn, H. G.

    2007-01-01

    We investigate the carrier injection and transport in individual para-hexaphenylene nanofibers by electrical transport measurements at different temperatures. The injected current shows much weaker temperature dependence than what would be anticipated from a simplistic model that considers the in...

  20. Phytoplankton Temperature Adaptation: Upstream or Local Temperature?

    Science.gov (United States)

    van Sebille, E.; Hellweger, F. L.; Calfee, B. C.; Chandler, J. W.; Zinser, E. R.; Fredrick, N. D.

    2016-02-01

    Biogeography studies that aim to understand the role of environmental variables are typically based on local conditions. However, in cases with substantial translocation, like for planktonic organisms carried by ocean currents, selection may happen upstream and the local environmental factors may not be representative of those that shaped the local population. Here we use an agent-based model of microbes in the global surface ocean to explore this effect for temperature. We simulate up to 25 million individual cells belonging to up to 50 species with different temperature optima. Microbes are moved around the globe based on a hydrodynamic model, and grow and die based on local temperature. The optimum temperature at each location and time is defined as the optimum temperature of the most abundant species. This allows us to quantify the role of currents using the "advective temperature differential" metric, which is the optimum temperature of the model with advection minus that from the model without advection. Our results suggest that the differential depends on the location and growth rate. Poleward-flowing currents, like the Gulf Stream, generally experience cooling and the differential is positive. For slow-growing microbes like heterotrophic bacteria, the differential can be up to 4 °C in these areas. In other words, ignoring currents introduces an error of up to 4 °C in a biogeographic analysis. We compare our model to observations of optimum growth temperature for phytoplankton. Accounting for the effect of currents leads to a slightly better agreement with observations, but there is large variability in the observations and the improvement is not statistically significant. Image Description: Advective temperature differential (DTopt) across the global ocean, defined as the difference between optimum temperatures from simulation with and without advective transport. Population average growth rate = 0.14/d.

  1. Spent fuel transporting vessel

    International Nuclear Information System (INIS)

    Kumagaya, Takeshi.

    1995-01-01

    A large number of annular cooling fins are disposed each at an equal distance on the outer circumferential surface of a vessel main body. An electric power generation module is disposed on the surface of the cooling fins. The electric power generation module comprises a plurality of thermoelectric power generation elements. In each of the thermoelectric generation elements, the inner side thereof in contact with the surface of the cooling fin is at a high temperature while the outer side thereof is at a low temperature nearly equal with an atmospheric temperature. A predetermined amount of electric power is generated by seebeck effect due to the temperature difference. The electric power is always stored in a battery. Accordingly, even if a power generator of a ship should fail and power supply is stopped during transportation of the vessels for spent nuclear fuels, an appropriate amount of electric power can be supplied to a cooling device of the ship. (I.N.)

  2. Solitonic Josephson Thermal Transport

    Science.gov (United States)

    Guarcello, Claudio; Solinas, Paolo; Braggio, Alessandro; Giazotto, Francesco

    2018-03-01

    We explore the coherent thermal transport sustained by solitons through a long Josephson junction as a thermal gradient across the system is established. We observe that a soliton causes the heat current through the system to increase. Correspondingly, the junction warms up in conjunction with the soliton, with temperature peaks up to, e.g., approximately 56 mK for a realistic Nb-based proposed setup at a bath temperature Tbath=4.2 K . The thermal effects on the dynamics of the soliton are also discussed. Markedly, this system inherits the topological robustness of the solitons. In view of these results, the proposed device can effectively find an application as a superconducting thermal router in which the thermal transport can be locally mastered through solitonic excitations, whose positions can be externally controlled through a magnetic field and a bias current.

  3. Metal temperature monitoring in corrosive gases at high temperature and high thermal flows; Monitoreo de temperaturas de metal en gases corrosivos a alta temperatura y altos flujos termicos

    Energy Technology Data Exchange (ETDEWEB)

    Huerta Espino, Mario; Martinez Flores, Marco Antonio; Martinez Villafane, Alberto; Porcayo Calderon, Jesus; Gomez Guzman, Roberto; Reyes Cervantes, Fernando [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    The direct measurement of metal temperatures during operation in superheater, reheater, and water wall tubes in zones exposed to high thermal flows is of great interest for the operation and analysis of the correct functioning of a steam generator. The operation temperature measurement of these zones differs very much of the monitored temperature in headers in the dead chamber, since the temperature measured in this zone is the steam temperature that does not reflect the one detected in the gas zone. For this reason, the thermocouples implant in gas zones will detect the real metal temperature and the incidence that some operation variables might have on it (Martinez et al., (1990). [Espanol] La medicion directa de temperaturas de metal durante operacion en tubos de sobrecalentador, recalentador y pared de agua en zonas expuestas a altos flujos termicos es de gran interes para la operacion y analisis del buen funcionamiento de un generador de vapor. La medicion de la temperatura de operacion de estas zonas, difiere mucho de la temperatura monitoreada en cabezales en zona de camara muerta, ya que la temperatura registrada en esta zona es la de vapor que no es un reflejo de la detectada en zona de gases. Por esta razon, la implantacion de termopares en zona de gases detectara la temperatura de metal real y la incidencia que algunas variables de operacion tengan sobre esta (Martinez et al., 1990).

  4. Ultrafast Thermal Transport at Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Cahill, David [Univ. of Illinois, Champaign, IL (United States); Murphy, Catherine [Univ. of Illinois, Champaign, IL (United States); Martin, Lane [Univ. of Illinois, Champaign, IL (United States)

    2014-10-21

    Our research program on Ultrafast Thermal Transport at Interfaces advanced understanding of the mesoscale science of heat conduction. At the length and time scales of atoms and atomic motions, energy is transported by interactions between single-particle and collective excitations. At macroscopic scales, entropy, temperature, and heat are the governing concepts. Key gaps in fundamental knowledge appear at the transitions between these two regimes. The transport of thermal energy at interfaces plays a pivotal role in these scientific issues. Measurements of heat transport with ultrafast time resolution are needed because picoseconds are the fundamental scales where the lack of equilibrium between various thermal excitations becomes a important factor in the transport physics. A critical aspect of our work has been the development of experimental methods and model systems that enabled more precise and sensitive investigations of nanoscale thermal transport.

  5. Animal Transports

    Directory of Open Access Journals (Sweden)

    Diana Ludrovcová

    2016-08-01

    Full Text Available Purpose and Originality: The research is aimed to the animal transports issue, from two points of view – first is the animal cruelty and second is the policy and economic consideration. The goal is to acquaint the readers with the transports risks and its cruelty and evaluation of the economic, political aspects for he involved countries. The study is oriented on more points of view, what is rare in works with a similar theme. Method: This paper examines many issues and examinations from different authors and subsequently summarized the findings with authors own knowledge to one expanded unit. Results: Results proves, that livestock transports have negative impact on animal´s health, environment. Number of transported animals is rising every year. Society: Research familiarize the society with the animal transports, cruelty against animals during them, and influence of transports on some countries, their economy, policy. People get better informed and can form their own opinion on this topic. They may start acting, undertaking some steps to improve the present situation, what could help a lot to animals and environment. Limitations / further research: Future research could show progress and improvement of transports, quality of food supply and economics.

  6. Transport phenomena II essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena II covers forced convention, temperature distribution, free convection, diffusitivity and the mechanism of mass transfer, convective mass transfer, concentration

  7. Transport Phenomena.

    Science.gov (United States)

    Shah, D. B.

    1984-01-01

    Describes a course designed to achieve a balance between exposing students to (1) advanced topics in transport phenomena, pointing out similarities and differences between three transfer processes and (2) common methods of solving differential equations. (JN)

  8. Nicaragua - Transportation

    Data.gov (United States)

    Millennium Challenge Corporation — The evaluation examines impacts of the Transportation Project in three ways. First, we calculate economic rates of return associated with reduced user costs for each...

  9. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... In ocean transportation economics we present investment and operating costs as well as the results of a study of financing of shipping. Similarly, a discussion of government aid to shipping is presented.

  10. Transport service

    CERN Multimedia

    C. Cerruti / FI

    2006-01-01

    A large number of pallet-crates (panières grillagées), which are used for transporting equipment and for removals, have been dispatched to various locations around the CERN site. We kindly request all users who may have such crates in their possession and no longer need them to make the necessary arrangements (EDH request to the Transport Group) to return them to Building 133, as we currently have no more in stock. Claude CERRUTI / FI-PI

  11. RF transport

    CERN Document Server

    Choroba, Stefan

    2013-01-01

    This paper deals with the techniques of transport of high-power radiofrequency (RF) power from a RF power source to the cavities of an accelerator. Since the theory of electromagnetic waves in waveguides and of waveguide components is very well explained in a number of excellent text books it will limit itself on special waveguide distributions and on a number of, although not complete list of, special problems which sometimes occur in RF power transportation systems.

  12. Public transport

    OpenAIRE

    Lethbridge, Jane

    2008-01-01

    Public transport plays an essential role in enabling people from low income and other disadvantaged groups to access employment and services. It also contributes to the development of social networks and social capital, by helping people to visit friends and relatives and take part in community and other social activities. Public policy makers have begun to recognise that adequate public transport provision can play an important role in reducing social exclusion. [Taken from introductory para...

  13. Drone transportation of blood products.

    Science.gov (United States)

    Amukele, Timothy; Ness, Paul M; Tobian, Aaron A R; Boyd, Joan; Street, Jeff

    2017-03-01

    Small civilian unmanned aerial vehicles (drones) are a novel way to transport small goods. To the best of our knowledge there are no studies examining the impact of drone transport on blood products, describing approaches to maintaining temperature control, or component physical characteristics during drone transport. Six leukoreduced red blood cell (RBC) and six apheresis platelet (PLT) units were split using sterile techniques. The larger parent RBC and PLT units, as well as six unthawed plasma units frozen within 24 hours of collection (FP24), were placed in a cooler, attached to the drone, and flown for up to 26.5 minutes with temperature logging. Ambient temperatures during the experimental window ranged between -1 and 18°C across 2 days. The difference between the ambient and unit temperatures was approximately 20°C for PLT and FP24 units. After flight, the RBC parent units were centrifuged and visually checked for hemolysis; the PLTs were checked for changes in mean PLT volumes (MPVs), pH, and PLT count; and the frozen air bubbles on the back of the FP24 units were examined for any changes in size or shape, as evidence of thawing. There was no evidence of RBC hemolysis; no significant changes in PLT count, pH, or MPVs; and no changes in the FP24 bubbles. The temperature of all units was maintained during transport and flight. There was no adverse impact of drone transport on RBC, PLT, or FP24 units. These findings suggest that drone transportation systems are a viable option for the transportation of blood products. © 2016 AABB.

  14. Transport Properties of Liquid Metals

    International Nuclear Information System (INIS)

    Kart, H.H.

    2004-01-01

    Transport properties of Pd, Ag pure metals and their binary alloys are investigated by using molecular dynamics simulation. Quantum Sutton-Chen (Q-SC) many-body potential is used to define the interactions between the atoms. The effects of temperature and concentration on the transport properties such as diffusion and viscosity of the metals are analysed. The simulation results are in good agreement with the experimental and theoretical values

  15. Potential wine ageing during transportation

    Directory of Open Access Journals (Sweden)

    Jung Rainer

    2014-01-01

    Full Text Available In a global world, wineries have to satisfy the demand of consumers who wish to drink high quality wines from countries all over the world. To fulfill this request wines have to be transported, crossing thereby great distances from the place of production to the consumer country. At the Institute of Enology of Hochschule Geisenheim University examinations with White-, Rosé- and Red-Wines of different origins which had been transported over longer distances within Europe (Portugal, France, Italy to Germany by trucks were carried out. Shipping of wines was simulated in a climatized cabinet to analyze the influence on wine quality during this way and conditions of transportation. Time and temperature profiles were based on real transport situtations which were recorded during shipping from Germany to Japan using data loggers. White, Rosé and Red wines were transported during 6 to 8 weeks and then were analytically and sensorically compared to those which were stored at a constant temperature of 15 ∘C. Besides the effect of temperature, the movements and vibrations encountered by the wines were also examined. Analytically wines were analyzed for general analytical parameters with Fourier-Transformation-Infrared-Spectroscopie (FTIR, Colour differences (Spectralphotometrie and free and total sulfuric acid with Flow-Injection-Analysis (FIA. Sensory examinations with a trained panel were performed in difference tests in form of rankings and triangular tests. Summarizing the results from the different tests it could be found that transportation had an influence on the potential ageing of wines depending on the wine matrix. Especially high and varying temperatures during transportations over a longer distance and time had negative influences on wine quality. Also the movement of wine at higher temperatures had showed a negative effect whereas transport at cool temperatures even below 0 ∘C did not influence wine characteristics. Sophisticated

  16. Temperature measurement

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003400.htm Temperature measurement To use the sharing features on this page, please enable JavaScript. The measurement of body temperature can help detect illness. It can also monitor ...

  17. Interfacility transports.

    Science.gov (United States)

    Blackwell, Thomas H

    2002-02-01

    Financial pressures exerted by managed care organizations toward hospitals to improve efficiencies and to lower total healthcare costs continue to force physicians and administrators to reevaluate operations and practices. This shifting of risk exposure from insurers to providers has resulted in many mergers, acquisitions, and affiliations, so as to form integrated health systems that reduce repetition and duplication of services. Therefore, as these integrated systems develop, along with the emergence of tertiary care, regional referral, and specialty hospitals, the need for patient transfers between such facilities will expand. The decision to move patients between facilities is a multicomponent process comprising health, safety, financial, and legal concerns. Interfacility transportation of patients has been performed over the past 20 to 30 years. Whereas ground transport services were prominent in the 1970s, air medical programs using helicopters and fixed-wing aircraft have recently become widespread. Both hospital-based and private agencies have continued to develop programs for efficiently and expeditiously transporting critically ill or injured patients, many requiring complex life-support devices. The Practice Management Committee of the American College of Emergency Physicians recently updated the 1990 policy statement on interfacility transfers, and two position statements are available from the National Association of EMS Physicians on criteria for air medical transport and medical direction for interfacility transport services. This review provides an overview of transportation systems and services available and assists physicians in understanding the various modes and characteristics of systems available. Personnel configurations and capabilities, physiological limitations, inherent requirements for equipment and patient preparation, and legal issues involved with transferring patients are also outlined.

  18. Heat transport through atomic contacts.

    Science.gov (United States)

    Mosso, Nico; Drechsler, Ute; Menges, Fabian; Nirmalraj, Peter; Karg, Siegfried; Riel, Heike; Gotsmann, Bernd

    2017-05-01

    Heat transport and dissipation at the nanoscale severely limit the scaling of high-performance electronic devices and circuits. Metallic atomic junctions serve as model systems to probe electrical and thermal transport down to the atomic level as well as quantum effects that occur in one-dimensional (1D) systems. Whereas charge transport in atomic junctions has been studied intensively in the past two decades, heat transport remains poorly characterized because it requires the combination of a high sensitivity to small heat fluxes and the formation of stable atomic contacts. Here we report heat-transfer measurements through atomic junctions and analyse the thermal conductance of single-atom gold contacts at room temperature. Simultaneous measurements of charge and heat transport reveal the proportionality of electrical and thermal conductance, quantized with the respective conductance quanta. This constitutes a verification of the Wiedemann-Franz law at the atomic scale.

  19. Travel and transport

    DEFF Research Database (Denmark)

    Bill, Jan; Roesdahl, Else

    2007-01-01

    On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments......On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments...

  20. Optimal transport

    CERN Document Server

    Eckmann, B

    2008-01-01

    At the close of the 1980s, the independent contributions of Yann Brenier, Mike Cullen and John Mather launched a revolution in the venerable field of optimal transport founded by G Monge in the 18th century, which has made breathtaking forays into various other domains of mathematics ever since. The author presents a broad overview of this area.

  1. Transport fuel

    DEFF Research Database (Denmark)

    Ronsse, Frederik; Jørgensen, Henning; Schüßler, Ingmar

    2014-01-01

    Worldwide, the use of transport fuel derived from biomass increased four-fold between 2003 and 2012. Mainly based on food resources, these conventional biofuels did not achieve the expected emission savings and contributed to higher prices for food commod - ities, especially maize and oilseeds...

  2. Nuclear transport

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    Here is given the decree (2001/1199) of the 10. of december 2001 relative to the passing of safety rules concerning the maritime transport of spent fuels, plutonium and high-level radioactive wastes contained in packages. (O.M.)

  3. Transport system

    NARCIS (Netherlands)

    Drenth, K.F.

    1999-01-01

    The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a

  4. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Affonso Lourenco; Evren Ozbayoglu; Lei Zhou

    2002-01-30

    This is the second quarterly progress report for Year 3 of the ACTS project. It includes a review of progress made in: (1) Flow Loop development and (2) research tasks during the period of time between Oct 1, 2001 and Dec. 31, 2001. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Collection System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  5. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30

    The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

  6. Nonlinear chiral transport phenomena

    Science.gov (United States)

    Chen, Jiunn-Wei; Ishii, Takeaki; Pu, Shi; Yamamoto, Naoki

    2016-06-01

    We study the nonlinear responses of relativistic chiral matter to the external fields such as the electric field E , gradients of temperature and chemical potential, ∇T and ∇μ . Using the kinetic theory with Berry curvature corrections under the relaxation time approximation, we compute the transport coefficients of possible new electric currents that are forbidden in usual chirally symmetric matter but are allowed in chirally asymmetric matter by parity. In particular, we find a new type of electric current proportional to ∇μ ×E due to the interplay between the effects of the Berry curvature and collisions. We also derive an analog of the "Wiedemann-Franz" law specific for anomalous nonlinear transport in relativistic chiral matter.

  7. 49 CFR 195.102 - Design temperature.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Design temperature. 195.102 Section 195.102... PIPELINE Design Requirements § 195.102 Design temperature. (a) Material for components of the system must be chosen for the temperature environment in which the components will be used so that the pipeline...

  8. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu

    2000-07-30

    ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

  9. Fundamental aspects of plasma chemical physics transport

    CERN Document Server

    Capitelli, Mario; Laricchiuta, Annarita

    2013-01-01

    Fundamental Aspects of Plasma Chemical Physics: Tranpsort develops basic and advanced concepts of plasma transport to the modern treatment of the Chapman-Enskog method for the solution of the Boltzmann transport equation. The book invites the reader to consider actual problems of the transport of thermal plasmas with particular attention to the derivation of diffusion- and viscosity-type transport cross sections, stressing the role of resonant charge-exchange processes in affecting the diffusion-type collision calculation of viscosity-type collision integrals. A wide range of topics is then discussed including (1) the effect of non-equilibrium vibrational distributions on the transport of vibrational energy, (2) the role of electronically excited states in the transport properties of thermal plasmas, (3) the dependence of transport properties on the multitude of Saha equations for multi-temperature plasmas, and (4) the effect of the magnetic field on transport properties. Throughout the book, worked examples ...

  10. High temperature pipeline design

    Energy Technology Data Exchange (ETDEWEB)

    Greenslade, J.G. [Colt Engineering, Calgary, AB (Canada). Pipelines Dept.; Nixon, J.F. [Nixon Geotech Ltd., Calgary, AB (Canada); Dyck, D.W. [Stress Tech Engineering Inc., Calgary, AB (Canada)

    2004-07-01

    It is impractical to transport bitumen and heavy oil by pipelines at ambient temperature unless diluents are added to reduce the viscosity. A diluted bitumen pipeline is commonly referred to as a dilbit pipeline. The diluent routinely used is natural gas condensate. Since natural gas condensate is limited in supply, it must be recovered and reused at high cost. This paper presented an alternative to the use of diluent to reduce the viscosity of heavy oil or bitumen. The following two basic design issues for a hot bitumen (hotbit) pipeline were presented: (1) modelling the restart problem, and, (2) establishing the maximum practical operating temperature. The transient behaviour during restart of a high temperature pipeline carrying viscous fluids was modelled using the concept of flow capacity. Although the design conditions were hypothetical, they could be encountered in the Athabasca oilsands. It was shown that environmental disturbances occur when the fluid is cooled during shut down because the ground temperature near the pipeline rises. This can change growing conditions, even near deeply buried insulated pipelines. Axial thermal loads also constrain the design and operation of a buried pipeline as higher operating temperatures are considered. As such, strain based design provides the opportunity to design for higher operating temperature than allowable stress based design methods. Expansion loops can partially relieve the thermal stress at a given temperature. As the design temperature increase, there is a point at which above grade pipelines become attractive options, although the materials and welding procedures must be suitable for low temperature service. 3 refs., 1 tab., 10 figs.

  11. Charge and spin transport in mesoscopic superconductors

    Directory of Open Access Journals (Sweden)

    M. J. Wolf

    2014-02-01

    Full Text Available Background: Non-equilibrium charge transport in superconductors has been investigated intensely in the 1970s and 1980s, mostly in the vicinity of the critical temperature. Much less attention has been paid to low temperatures and the role of the quasiparticle spin.Results: We report here on nonlocal transport in superconductor hybrid structures at very low temperatures. By comparing the nonlocal conductance obtained by using ferromagnetic and normal-metal detectors, we discriminate charge and spin degrees of freedom. We observe spin injection and long-range transport of pure, chargeless spin currents in the regime of large Zeeman splitting. We elucidate charge and spin transport by comparison to theoretical models.Conclusion: The observed long-range chargeless spin transport opens a new path to manipulate and utilize the quasiparticle spin in superconductor nanostructures.

  12. 14 CFR 29.1157 - Carburetor air temperature controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 29... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature...

  13. 14 CFR 25.1157 - Carburetor air temperature controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 25... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature...

  14. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  15. Transport losses in finisher pigs: impact of transport distance and season of the year

    Directory of Open Access Journals (Sweden)

    Eva Voslarova

    2017-01-01

    Full Text Available Objective The death of animals during transport for slaughter is a major factor indicating the level of welfare in transported animals. The aim of this study was to assess mortality related to the commercial transport of finisher pigs for slaughter in the Czech Republic. Methods The inspectors of the State Veterinary Administration of the Czech Republic recorded the numbers of finisher pigs transported to processing plants in the Czech Republic for slaughter and the mortality in these pigs in relation to transport in the period from 2009 to 2014. Results Our results show that the likelihood of death losses in transported pigs increases with increasing transport distance. The transport-related mortality ranged from 0.049% in pigs transported for distances below 50 km to 0.145% in pigs transported for distances exceeding 300 km. The impact of external air temperature on the transport-related mortality found in our study clearly shows that current transport practices fail to ensure the welfare of pigs transported under other than moderate weather. Particularly cold temperatures below −2°C were associated with increased death losses in winter transport. Conclusion Despite a decreasing trend in the mortality of finisher pigs transported for slaughter in Europe, our study suggests that current transport conditions are not efficient at ensuring the welfare of pigs during transport for longer distances and the protection of pigs against the negative impact of extreme ambient temperatures. Further research should focus on developing practical guidelines to improve the welfare of pigs in transit accordingly.

  16. Spin transport in graphene nanostructures

    NARCIS (Netherlands)

    Guimaraes, M. H. D.; van den Berg, J. J.; Vera-Marun, I. J.; Zomer, P. J.; van Wees, B. J.

    2014-01-01

    Graphene is an interesting material for spintronics, showing long spin relaxation lengths even at room temperature. For future spintronic devices it is important to understand the behavior of the spins and the limitations for spin transport in structures where the dimensions are smaller than the

  17. Quantum transport in semiconductor nanowires

    NARCIS (Netherlands)

    Van Dam, J.

    2006-01-01

    This thesis describes a series of experiments aimed at understanding the low-temperature electrical transport properties of semiconductor nanowires. The semiconductor nanowires (1-100 nm in diameter) are grown from nanoscale gold particles via a chemical process called vapor-liquid-solid (VLS)

  18. Quantum transport in carbon nanotubes

    NARCIS (Netherlands)

    Jarillo-Herrero, P.D.

    2005-01-01

    Electronic transport through nanostructures can be very different from trans- port in macroscopic conductors, especially at low temperatures. Carbon na- notubes are tiny cylinders made of carbon atoms. Their remarkable electronic and mechanical properties, together with their small size (a few nm in

  19. Thermal energy storage and transport

    Science.gov (United States)

    Hausz, W.

    1980-01-01

    The extraction of thermal energy from large LWR and coal fired plants for long distance transport to industrial and residential/commercial users is analyzed. Transport of thermal energy as high temperature water is shown to be considerably cheaper than transport as steam, hot oil, or molten salt over a wide temperature range. The delivered heat is competitive with user-generated heat from oil, coal, or electrode boilers at distances well over 50 km when the pipeline operates at high capacity factor. Results indicate that thermal energy storage makes meeting of even very low capacity factor heat demands economic and feasible and gives the utility flexibility to meet coincident electricity and heat demands effectively.

  20. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2003-01-01

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.

  1. Transporter Classification Database (TCDB)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Transporter Classification Database details a comprehensive classification system for membrane transport proteins known as the Transporter Classification (TC)...

  2. Plasma thermal energy transport: theory and experiments

    International Nuclear Information System (INIS)

    Coppi, B.

    Experiments on the transport across the magnetic field of electron thermal energy are reviewed (Alcator, Frascati Torus). In order to explain the experimental results, a transport model is described that reconfirmed the need to have an expression for the local diffusion coefficient with a negative exponent of the electron temperature

  3. Charge transport in organic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ortmann, Frank

    2009-07-01

    The understanding of charge transport is one of the central goals in the research on semiconducting crystals. For organic crystals this is particularly complicated due to the strength of the electron-phonon interaction which requires the description of a seamless transition between the limiting cases of a coherent band-transport mechanism and incoherent hopping. In this thesis, charge transport phenomena in organic crystals are studied by theoretical means. A theory for charge transport in organic crystals is developed which covers the whole temperature range from low T, where it reproduces an expression from the Boltzmann equation for band transport, via elevated T, where it generalizes Holstein's small-polaron theory to finite bandwidths, up to high T, for which a temperature dependence equal to Marcus' electron-transfer theory is obtained. Thereby, coherent band transport and thermally induced hopping are treated on equal footing while simultaneously treating the electron-phonon interaction non-perturbatively. By avoiding the approximation of narrow polaron bands the theory allows for the description of large and small polarons and serves as a starting point for computational studies. The theoretical description is completed by using ab initio material parameters for the selected crystals under study. These material parameters are taken from density functional theory calculations for durene, naphthalene, and guanine crystals. Besides the analysis of the transport mechanism, special focus is put on the study of the relationship between mobility anisotropy and structure of the crystals. This study is supported by a 3D-visualization method for the transport channels in such crystals which has been derived in this thesis. (orig.)

  4. Proton Transport

    Science.gov (United States)

    Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The transport of protons across membranes is an essential process for both bioenergetics of modern cells and the origins of cellular life. All living systems make use of proton gradients across cell walls to convert environmental energy into a high-energy chemical compound, adenosine triphosphate (ATP), synthesized from adenosine diphosphate. ATP, in turn, is used as a source of energy to drive many cellular reactions. The ubiquity of this process in biology suggests that even the earliest cellular systems were relying on proton gradient for harvesting environmental energy needed to support their survival and growth. In contemporary cells, proton transfer is assisted by large, complex proteins embedded in membranes. The issue addressed in this Study was: how the same process can be accomplished with the aid of similar but much simpler molecules that could have existed in the protobiological milieu? The model system used in the study contained a bilayer membrane made of phospholipid, dimyristoylphosphatidylcholine (DMPC) which is a good model of the biological membranes forming cellular boundaries. Both sides of the bilayer were surrounded by water which simulated the environment inside and outside the cell. Embedded in the membrane was a fragment of the Influenza-A M$_2$ protein and enough sodium counterions to maintain system neutrality. This protein has been shown to exhibit remarkably high rates of proton transport and, therefore, is an excellent model to study the formation of proton gradients across membranes. The Influenza M$_2$ protein is 97 amino acids in length, but a fragment 25 amino acids long. which contains a transmembrane domain of 19 amino acids flanked by three amino acids on each side. is sufficient to transport protons. Four identical protein fragments, each folded into a helix, aggregate to form small channels spanning the membrane. Protons are conducted through a narrow pore in the middle of the channel in response to applied voltage. This

  5. National transportation statistics 2011

    Science.gov (United States)

    2011-04-01

    Compiled and published by the U.S. Department of Transportation's Bureau of Transportation Statistics (BTS), National Transportation Statistics presents information on the U.S. transportation system, including its physical components, safety record, ...

  6. Temperature metrology

    International Nuclear Information System (INIS)

    Fischer, J; Fellmuth, B

    2005-01-01

    The majority of the processes used by the manufacturing industry depend upon the accurate measurement and control of temperature. Thermal metrology is also a key factor affecting the efficiency and environmental impact of many high-energy industrial processes, the development of innovative products and the health and safety of the general population. Applications range from the processing, storage and shipment of perishable foodstuffs and biological materials to the development of more efficient and less environmentally polluting combustion processes for steel-making. Accurate measurement and control of temperature is, for instance, also important in areas such as the characterization of new materials used in the automotive, aerospace and semiconductor industries. This paper reviews the current status of temperature metrology. It starts with the determination of thermodynamic temperatures required on principle because temperature is an intensive quantity. Methods to determine thermodynamic temperatures are reviewed in detail to introduce the underlying physical basis. As these methods cannot usually be applied for practical measurements the need for a practical temperature scale for day-to-day work is motivated. The International Temperature Scale of 1990 and the Provisional Low Temperature Scale PLTS-2000 are described as important parts of the International System of Units to support science and technology. Its main importance becomes obvious in connection with industrial development and international markets. Every country is strongly interested in unique measures, in order to guarantee quality, reproducibility and functionability of products. The eventual realization of an international system, however, is only possible within the well-functioning organization of metrological laboratories. In developed countries the government established scientific institutes have certain metrological duties, as, for instance, the maintenance and dissemination of national

  7. Thermodynamic and transport properties of fluids

    Science.gov (United States)

    Fessler, T. E.

    1980-01-01

    Computer program subroutine FLUID calculates thermodynamic and transport properties of pure fluids in liquid, gas, or two-phase (liquid/gas) conditions. Program determines thermodynamic state from assigned values for temperature and density, pressure and density, temperature and pressure, pressure and entropy, or pressure and enthalpy.

  8. High Temperature Resistant Exhaust Valve Spindle

    DEFF Research Database (Denmark)

    Bihlet, Uffe Ditlev

    Transport by ship remains the most economical and environmentally friendly mode of transport with a very low weight specific CO2 footprint. Further increase of the fuel efficiency of large ships will results in a higher internal engine temperature. To allow this without compromising the reliabili...

  9. TCP with header checksum option for wireless links: An analytical ...

    Indian Academy of Sciences (India)

    TCP was designed for wired networks, where packet losses are mainly due to congestion. In today's world, more and more people use their mobile devices to access the Internet either for work or entertainment, where TCP runs over wireless links and is subjected to more corruption losses as compared to congestion losses.

  10. Techniques for the Detection of Faulty Packet Header Modifications

    Science.gov (United States)

    2014-03-12

    by comparing packets sent against packets received at the other end by cataloging mini-hashes on a third-party server. This approach can be used to...pp. 263–297, Aug. 2000. [42] “IEEE standard for information technology– telecommunications and information exchange between systems–local and...metropolitan area networks–specific requirements part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer

  11. TCP with header checksum option for wireless links: An analytical ...

    Indian Academy of Sciences (India)

    Balakrishnan et al ... performing re-transmissions of any lost data to avoid coarse timeouts. ..... future. Also from the protocol rules, the value of W (tk) can only be equal to one (timeout case) or to Wth(t) (successful loss recovery). Note that the channel ...

  12. TRANSPORT PROPERTIES FOR REFRIGERANT MIXTURES

    Directory of Open Access Journals (Sweden)

    V. Geller

    2014-06-01

    Full Text Available A set of models to predict viscosity and thermal conductivity of refrigerant mixtures is developed. A general model for viscosity and thermal conductivity use the three contributions sum form (the dilute-gas terms, the residual terms, and the liquid terms. The corresponding states model is recommended to predict the dense gas transport properties over a range of reduced density from 0 to 2. It is shown that the RHS model provides the most reliable results for the saturated-liquid and the compressed-liquid transport properties over a range of given temperatures from 0,5 to 0,95.

  13. Electron heat transport analysis of low-collisionality plasmas in the neoclassical-transport-optimized configuration of LHD

    International Nuclear Information System (INIS)

    Murakami, Sadayoshi; Yamada, Hiroshi; Wakasa, Arimitsu

    2002-01-01

    Electron heat transport in low-collisionality LHD plasma is investigated in order to study the neoclassical transport optimization effect on thermal plasma transport with an optimization level typical of so-called ''advanced stellarators''. In the central region, a higher electron temperature is obtained in the optimized configuration, and transport analysis suggests the considerable effect of neoclassical transport on the electron heat transport assuming the ion-root level of radial electric field. The obtained experimental results support future reactor design in which the neoclassical and/or anomalous transports are reduced by magnetic field optimization in a non-axisymmetric configuration. (author)

  14. Development of a cell sheet transportation technique for regenerative medicine.

    Science.gov (United States)

    Oie, Yoshinori; Nozaki, Takayuki; Takayanagi, Hiroshi; Hara, Susumu; Hayashi, Ryuhei; Takeda, Shizu; Mori, Keisuke; Moriya, Noboru; Soma, Takeshi; Tsujikawa, Motokazu; Saito, Kazuo; Nishida, Kohji

    2014-05-01

    A transportation technique for cell sheets is necessary to standardize regenerative medicine. The aim of this article is to develop and evaluate a new transportation technique for cell sheets. We developed a transportation container with three basic functions: the maintenance of interior temperature, air pressure, and sterility. The interior temperature and air pressure were monitored by a recorder. Human oral mucosal epithelial cells obtained from two healthy volunteers were cultured on temperature-responsive culture dishes. The epithelial cell sheets were transported via an airplane between the Osaka University and Tohoku University using the developed cell transportation container. Histological and immunohistochemical analyses and flow cytometric analyses for cell viability and cell purity were performed for the cell sheets before and 12 h after transportation to assess the influence of transportation on the cell sheets. Sterility tests and screening for endotoxin and mycoplasma in the cell sheets were performed before and after transportation. During transportation via an airplane, the temperature inside the container was maintained above 32°C, and the changes in air pressure remained within 10 hPa. The cell sheets were well stratified and successfully harvested before and after transportation. The expression patterns of keratin 3/76, p63, and MUC16 were equivalent before and after transportation. However, the expression of ZO-1 in the cell sheet after transportation was slightly weaker than that before transportation. The cell viability was 72.0% before transportation and 77.3% after transportation. The epithelial purity was 94.6% before transportation and 87.9% after transportation. Sterility tests and screening for endotoxin and mycoplasma were negative for all cell sheets. The newly developed transportation technique for air travel is essential technology for regenerative medicine and promotes the standardization and spread of regenerative therapies.

  15. Formation and collapse of internal transport barrier

    International Nuclear Information System (INIS)

    Fukuyama, A.; Itoh, K.; Itoh, S.I.; Yagi, M.

    1999-01-01

    A theoretical model of internal transport barrier (ITB) is developed. The transport model based on the self-sustained turbulence theory of the current-diffusive ballooning mode is extended to include the effects of ExB rotation shear. Delayed formation of ITB is observed in transport simulations. The influence of finite gyroradius is also discussed. Simulation of the current ramp-up experiment successfully described the radial profile of density, temperature and safety factor. A model of ITB collapse due to magnetic braiding is proposed. Sudden enhancement of transport triggered by overlapping of magnetic islands terminates ITB. The possibility of destabilizing global low-n modes is also discussed. (author)

  16. Calculation of the thermodynamic and transport properties of aqueous species at high pressures and temperatures: Correlation algorithms for ionic species and equation of state predictions to 5 kb and 1000°C

    Science.gov (United States)

    Shock, Everett L.; Helgeson, Harold C.

    1988-08-01

    Correlation algorithms permit prediction of species-dependent parameters in revised equations of state ( TANGER and HELGESON, 1988) for aqueous ions and electrolytes which can be used together with values at 25°C and 1 bar of the standard partial molal entropies ( S0), volumes ( V0), and heat capacities ( C0p) of the ions to calculate their standard partial molal thermodynamic properties at pressures and temperatures to 5 kb and 1000°C. Values of V0 and C0p at 25°C and 1 bar have been calculated for 128 aqueous ions from analysis of published experimental data or from correlations of these properties with S0. Equation of state parameters have also been generated for these ions and examples are given of predicted standard partial molal thermodynamic properties of representative cations and anions at high pressures and temperatures. Close agreement between independently predicted and experimentally determined equilibrium constants for acid anion dissociation reactions at high temperatures supports the validity and generality of the predictive algorithms.

  17. Transport phenomena of aluminium oxide in metal halide lamps

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, S; Markus, T [Institute for Energy Research, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany); Niemann, U [Philips GmbH, Research Laboratories, PO Box 500145, Aachen, D-52085 (Germany)], E-mail: s.fischer@fz-juelich.de

    2008-07-21

    A better understanding of the transport phenomena observed in metal halide lamps can be achieved using computer-based model calculations. The chemical transport of aluminium oxide in advanced high-pressure discharge vessels was calculated as a function of temperature and composition of the salt mixture relevant to the lamp. Below 1773 K chemical transport is the prevailing process; above this temperature the vaporization and condensation of the envelope material-aluminium oxide-become more important. The results of the calculations show that the amount of transported alumina increases linearly with the number of iteration cycles and exponentially with the temperature gradient.

  18. Nonlinear heat and particle transport due to collisional drift waves

    Energy Technology Data Exchange (ETDEWEB)

    Nishi-kawa, K.I.; Hatori, T.; Terashima, Y.

    1977-03-01

    The nonlinear evolution of unstable modes which govern transport processes in magnetically confined plasmas were investigated. A nonlinear theory of unstable collisional drift wave, and the consequent nonlinear transport were extended to include electron and ion temperature gradients. Thermal transport properties are discussed and basic equations are given.

  19. Thermodynamic and transport properties of gaseous tetrafluoromethane in chemical equilibrium

    Science.gov (United States)

    Hunt, J. L.; Boney, L. R.

    1973-01-01

    Equations and in computer code are presented for the thermodynamic and transport properties of gaseous, undissociated tetrafluoromethane (CF4) in chemical equilibrium. The computer code calculates the thermodynamic and transport properties of CF4 when given any two of five thermodynamic variables (entropy, temperature, volume, pressure, and enthalpy). Equilibrium thermodynamic and transport property data are tabulated and pressure-enthalpy diagrams are presented.

  20. Evaluation of the stress response of heifers during transportation

    Science.gov (United States)

    To evaluate the stress associated with transportation; 22 heifers (326 ± 47 kg) were randomly assigned to a control (Con) or transport (Tran) group. On d 0, 12 h prior to the transportation, heifers were weighed and fitted with an indwelling rectal temperature (RT) probe, jugular catheters, and hear...

  1. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    Considerable experience has now been gained with the various beam transport lines, and a number of minor changes have been made to improve the ease of operation. These include: replacement of certain little-used slits by profile monitors (harps or scanners); relocation of steering magnets, closer to diagnostic harps or profile scanners; installation of a scanner inside the isocentric neutron therapy system; and conversion of a 2-doublet quadrupole telescope (on the neutron therapy beamline) to a 2-triplet telescope. The beam-swinger project has been delayed by very late delivery of the magnet iron to the manufacturer, but is now progressing smoothly. The K=600 spectrometer magnets have now been delivered and are being assembled for field mapping. The x,y-table with its associated mapping equipment is complete, together with the driver software. One of the experimental areas has been dedicated to the production of collimated neutron beams and has been equipped with a bending magnet and beam dump, together with steel collimators fixed at 4 degrees intervals from 0 degrees to 16 degrees. Changes to the target cooling and shielding system for isotope production have led to a request for much smaller beam spot sizes on target, and preparations have been made for rearrangement of the isotope beamline to permit installation of quadrupole triplets on the three beamlines after the switching magnet. A practical system of quadrupoles for matching beam properties to the spectrometer has been designed. 6 figs

  2. Transports under surveillance

    International Nuclear Information System (INIS)

    Jouette, I.

    2016-01-01

    Each year 770.000 nuclear transports are performed in France representing less than 3% of the transport of dangerous materials. This article review various aspects of nuclear transport: modes of transportation, packages, current legislation, safety and surveillance. A map presents the transport route of vitrified wastes from Sellafield plant to the Zwilag storing center in Switzerland at one moment this transport crosses France and another map presents the transport routes involved in the nuclear fuel cycle in France. (A.C.)

  3. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  4. EQUINE THERMOREGULATORY RESPONSES DURING SUMMERTIME ROAD TRANSPORT AND STALL CONFINEMENT

    Directory of Open Access Journals (Sweden)

    ANGELA R. GREEN

    2007-04-01

    Full Text Available Thermoregulatory responses of horses subjected to summer-time road transport and stall confinement were investigated in this study. Six mature geldings were transported 168 km in a 4-horse trailer and were monitored while tethered in their stalls, on alternate days. Core body temperature (GT demonstrated negligible response during transport, but GT following transport was higher than GT for non-transport. GT tended to increase with increased temperature humidity index (THI. THI within the trailer was greatest for positions near the front, and was influenced by daily weather which varied over experiment days from heat stress conditions to moderate discomfort.

  5. elevated temperatures

    African Journals Online (AJOL)

    2007-10-12

    Oct 12, 2007 ... crystals were heated to temperatures in the range 200- 270”C; The third precipitate phase was tentatively ... studied using X—ray diffraction techniques while their .... n noexpt-Q/RT) (3) where n0 is a constant, Q is the activation energy for the overall precipitation process, R is the molar gas constant and T.

  6. Animal transport and welfare with special emphasis on transport time and vibration

    OpenAIRE

    Aradom, Samuel

    2013-01-01

    Farm animals are transported several times during their lifetime and often long distances, and most of them are to slaughter. During transport they are exposed to a number of stress inducing factors. The main objective of the thesis work was to study the welfare of pigs, cows and bulls during transport from farm to abattoir. Parameters such as cortisol, glucose, lactate, creatine kinease, behaviour, carcass pH, temperature, relative humidity, THI and vibration were used to evaluate welfare of...

  7. Nanoscale thermal transport

    Science.gov (United States)

    Cahill, David G.; Ford, Wayne K.; Goodson, Kenneth E.; Mahan, Gerald D.; Majumdar, Arun; Maris, Humphrey J.; Merlin, Roberto; Phillpot, Simon R.

    2003-01-01

    Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid-solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime—experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The

  8. Transporting particulate material

    Science.gov (United States)

    Aldred, Derek Leslie [North Hollywood, CA; Rader, Jeffrey A [North Hollywood, CA; Saunders, Timothy W [North Hollywood, CA

    2011-08-30

    A material transporting system comprises a material transporting apparatus (100) including a material transporting apparatus hopper structure (200, 202), which comprises at least one rotary transporting apparatus; a stationary hub structure (900) constraining and assisting the at least one rotary transporting apparatus; an outlet duct configuration (700) configured to permit material to exit therefrom and comprising at least one diverging portion (702, 702'); an outlet abutment configuration (800) configured to direct material to the outlet duct configuration; an outlet valve assembly from the material transporting system venting the material transporting system; and a moving wall configuration in the material transporting apparatus capable of assisting the material transporting apparatus in transporting material in the material transporting system. Material can be moved from the material transporting apparatus hopper structure to the outlet duct configuration through the at least one rotary transporting apparatus, the outlet abutment configuration, and the outlet valve assembly.

  9. Plant Transporter Identification

    DEFF Research Database (Denmark)

    Larsen, Bo

    Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....

  10. Survey of transport environments of circus tigers (Panthera tigris).

    Science.gov (United States)

    Nevill, Christian H; Friend, Ted H; Toscano, Michael J

    2004-06-01

    The type of equipment used to transport circus tigers, environmental factors experienced during transport, and resultant body temperatures of tigers transported were surveyed during hot and cold weather conditions with six different circus tiger acts. Dataloggers recorded interior and exterior temperatures, relative humidity, and radiant heat at 5-min intervals during each trip. Microdataloggers fed to the tigers recorded body temperature and were recovered from eight Bengal (Panthera tigris tigris), Siberian (P. t. altaica), or Bengal-Sumatran (P. t. tigris-P. t. sumatrae) cross tigers from four different circuses. Three basic types of systems were used by circus acts to transport tigers: freestanding cages mounted on wheels that were winched or pushed into a semitrailer for transport, cages built into the trailer itself, and weather-resistant units transported on flatbed railcars or flatbed truck trailers. The highest temperature encountered inside a trailer was 37.3 degrees C in hot weather conditions, but overall, temperatures were usually between 21.1-26.7 degrees C. Temperature inside the trailers did not appear to be affected by movement and did not generally exceed ambient temperatures, indicating adequate insulation and passive ventilation. During cold weather trips, the lowest temperature inside the trailers was -1.1 degrees C, occurring during an overnight stop. Interior temperatures during cold weather transport stayed 2-6 degrees C warmer than ambient temperatures. The body temperatures of the tigers were unaffected by extreme temperatures. The only changes observed in body temperature were increases of 1-2 degrees C caused by activity and excitement associated with loading in several groups of tigers, regardless of whether it was hot or cold weather. Whenever measured, carbon monoxide and ammonia were below the detectable concentrations of 10 and 1 ppm. respectively. Overall, transport did not appear to have any adverse effects on the tigers' ability

  11. Transportation and the environment.

    NARCIS (Netherlands)

    Banister, D.; Anderton, K.; Bonilla, D.; Givoni, M.; Schwanen, T.

    2011-01-01

    The growth of CO2-intensive transport, mobility and the impact of transport on the environment are reviewed. The recent global exponential growth in transport is unsustainable and must end unless the transport sector can decarbonize. The paper examines solutions for low-carbon transport systems; the

  12. Transport diffusion in deformed carbon nanotubes

    Science.gov (United States)

    Feng, Jiamei; Chen, Peirong; Zheng, Dongqin; Zhong, Weirong

    2018-03-01

    Using non-equilibrium molecular dynamics and Monte Carlo methods, we have studied the transport diffusion of gas in deformed carbon nanotubes. Perfect carbon nanotube and various deformed carbon nanotubes are modeled as transport channels. It is found that the transport diffusion coefficient of gas does not change in twisted carbon nanotubes, but changes in XY-distortion, Z-distortion and local defect carbon nanotubes comparing with that of the perfect carbon nanotube. Furthermore, the change of transport diffusion coefficient is found to be associated with the deformation factor. The relationship between transport diffusion coefficient and temperature is also discussed in this paper. Our results may contribute to understanding the mechanism of molecular transport in nano-channel.

  13. Stochastic Energetics of Quantum Transport

    OpenAIRE

    Ghosh, Pulak Kumar; Ray, Deb Shankar

    2006-01-01

    We examine the stochastic energetics of directed quantum transport due to rectification of non-equilibrium thermal fluctuations. We calculate the quantum efficiency of a ratchet device both in presence and absence of an external load to characterize two quantifiers of efficiency. It has been shown that the quantum current as well as efficiency in absence of load (Stokes efficiency) is higher as compared to classical current and efficiency, respectively, at low temperature. The conventional ef...

  14. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  15. Nanoscale hotspots due to nonequilibrium thermal transport

    International Nuclear Information System (INIS)

    Sinha, Sanjiv; Goodson, Kenneth E.

    2004-01-01

    Recent experimental and modeling efforts have been directed towards the issue of temperature localization and hotspot formation in the vicinity of nanoscale heat generating devices. The nonequilibrium transport conditions which develop around these nanoscale devices results in elevated temperatures near the heat source which can not be predicted by continuum diffusion theory. Efforts to determine the severity of this temperature localization phenomena in silicon devices near and above room temperature are of technological importance to the development of microelectronics and other nanotechnologies. In this work, we have developed a new modeling tool in order to explore the magnitude of the additional thermal resistance which forms around nanoscale hotspots from temperatures of 100-1000K. The models are based on a two fluid approximation in which thermal energy is transferred between ''stationary'' optical phonons and fast propagating acoustic phonon modes. The results of the model have shown excellent agreement with experimental results of localized hotspots in silicon at lower temperatures. The model predicts that the effect of added thermal resistance due to the nonequilibrium phonon distribution is greatest at lower temperatures, but is maintained out to temperatures of 1000K. The resistance predicted by the numerical code can be easily integrated with continuum models in order to predict the temperature distribution around nanoscale heat sources with improved accuracy. Additional research efforts also focused on the measurements of the thermal resistance of silicon thin films at higher temperatures, with a focus on polycrystalline silicon. This work was intended to provide much needed experimental data on the thermal transport properties for micro and nanoscale devices built with this material. Initial experiments have shown that the exposure of polycrystalline silicon to high temperatures may induce recrystallization and radically increase the thermal

  16. temperature overspecification

    Directory of Open Access Journals (Sweden)

    Mehdi Dehghan

    2001-01-01

    Full Text Available Two different finite difference schemes for solving the two-dimensional parabolic inverse problem with temperature overspecification are considered. These schemes are developed for indentifying the control parameter which produces, at any given time, a desired temperature distribution at a given point in the spatial domain. The numerical methods discussed, are based on the (3,3 alternating direction implicit (ADI finite difference scheme and the (3,9 alternating direction implicit formula. These schemes are unconditionally stable. The basis of analysis of the finite difference equation considered here is the modified equivalent partial differential equation approach, developed from the 1974 work of Warming and Hyett [17]. This allows direct and simple comparison of the errors associated with the equations as well as providing a means to develop more accurate finite difference schemes. These schemes use less central processor times than the fully implicit schemes for two-dimensional diffusion with temperature overspecification. The alternating direction implicit schemes developed in this report use more CPU times than the fully explicit finite difference schemes, but their unconditional stability is significant. The results of numerical experiments are presented, and accuracy and the Central Processor (CPU times needed for each of the methods are discussed. We also give error estimates in the maximum norm for each of these methods.

  17. Advanced Transportation Institute 2009.

    Science.gov (United States)

    2009-09-01

    The eighth version of the Advanced Transportation Institute (ATI-09) was conducted in 2009 to encourage high school students to pursue careers in the field of transportation engineering. The University Transportation Center for Alabama partnered with...

  18. State transportation statistics 2009

    Science.gov (United States)

    2009-01-01

    The Bureau of Transportation Statistics (BTS), a part of DOTs Research and Innovative Technology Administration (RITA), presents State Transportation Statistics 2009, a statistical profile of transportation in the 50 states and the District of Col...

  19. Correlation of point defects in CdZnTe with charge transport:application to room-temperature X-ray and gamma-ray detectors. Final Technical Report

    International Nuclear Information System (INIS)

    Giles, Nancy C.

    2003-01-01

    The primary goal of this project has been to characterize and identify point defects (e.g., impurities, vacancies, vacancy-impurity complexes, etc.) in CdZnTe and determine the mechanisms by which these defects influence the carrier μτproducts. Special attention is given to the role of shallow donors, shallow acceptors, and deeper acceptors. There are two experimental focus areas in the project: (1) liquid-helium photoluminescence (PL) and PL excitation spectroscopy are used to identify and characterize donors and acceptors and to determine zinc molar fraction; and (2) electron paramagnetic resonance (EPR) and photoinduced EPR experiments are performed at liquid-helium temperature to identify paramagnetic point defects and to determine the concentration of these defects. Results from the two experimental focus areas are correlated with detector performance parameters (e.g., electron and hole μτ products), crystal growth conditions, and microstructure analyses

  20. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  1. Water/rock interactions and mass transport within a thermal gradient Application to the confinement of high level nuclear waste; Interactions solide/solution et transferts de matiere dans un gradient de temperature. Application au confinement des dechets nucleaires de haute-activite

    Energy Technology Data Exchange (ETDEWEB)

    Poinssot, Ch. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Entreposage et de Stockage des Dechets]|[Ecole Normale Superieure, 92 - Fontenay-aux-Roses (France). Laboratoire de Geologie

    1998-12-31

    The initial stage of a high level nuclear waste disposal will be characterised by a large heat release within the near-field environment of the canisters. This heat flux caused by radioactive decay will lead to an increase of temperature and a subsequent thermal gradient between the `hot` canisters and the `cold`geological medium. In addition, this thermal gradient will decrease with time due to the heat decay although it could last hundred years. What will be the consequences of such a thermal field varying both on space and time for the alteration of the different constituents of the near field environment. In particular, what could be the effects on the radionuclides migration in the accidental case of an early breach of a canister during the thermal stage? This study brings significant answers to these questions in the light of a performance assessment study. This work is supported by a triple methodological approach involving experimental studies, modelling calculations and a natural analogues study. This complete work demonstrates that a thermal gradient leads to a large re-distribution of elements within the system: some elements are incorporated in the solid phases of the hot end (Si, Zr, Ca) whereas some others are in those of the cold end (Fe, Al, Zn). The confrontation of the results of very simple experiments with the results of a model built on equilibrium thermodynamics allow us to evidence the probable mechanisms causing this mass transport: out-of-equilibrium thermodiffusion processes coupled to irreversible precipitation. Moreover, the effects of the variation of temperatures with time is studied by the way of a natural system which underwent a similar temperature evolution as a disposal and which was initially rich in uranium: the Jurassic Alpine bauxites. In addition, part of the initial bauxite escaped this temperature transformations due to their incorporation in outer thrusting nappes. They are used as a reference. (author)

  2. Journal of transportation engineering

    National Research Council Canada - National Science Library

    1983-01-01

    The Journal of Transportation Engineering contains technical and professional articles on the planning, design, construction, maintenance, and operation of air, highway, rail, and urban transportation...

  3. Saxton Transportation Operations Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Saxton Transportation Operations Laboratory (Saxton Laboratory) is a state-of-the-art facility for conducting transportation operations research. The laboratory...

  4. Smart Growth and Transportation

    Science.gov (United States)

    Describes the relationship between smart growth and transportation, focusing smart and sustainable street design, transit-oriented development, parking management, sustainable transportation planning, and related resources.

  5. 49 CFR 173.224 - Packaging and control and emergency temperatures for self-reactive materials.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Packaging and control and emergency temperatures... Administrator. (5) Control temperature. Column 5 specifies the control temperature in °C. Temperatures are specified only when temperature controls are required (see § 173.21(f)). (6) Emergency temperature. Column 6...

  6. Certification testing at low temperatures

    International Nuclear Information System (INIS)

    Noss, P.W.; Ammerman, D.J.

    2004-01-01

    Regulations governing the transport of radioactive materials require that most hypothetical accident condition tests or analyses consider the effects of the environmental temperature that most challenges package performance. For many packages, the most challenging temperature environment is the cold condition (-29 C according to U.S. regulations), primarily because the low temperature causes the highest free drop impact forces due to the higher strength of many energy-absorbing materials at this temperature. If it is decided to perform low temperature testing, it is only necessary that the relevant parts of the package have the required temperature prior to the drop. However, the details of performing a drop at low temperature can have a large influence on testing cost and technical effectiveness. The selection of the test site, the chamber and type of chilling equipment, instrumentation, and even the time of year are all important. Control of seemingly minor details such as the effect on internal pressure, placement of monitoring thermocouples, the thermal time constant of the test article, and icing of equipment are necessary to ensure a successful low temperature test. This paper will discuss these issues and offer suggestions based on recent experience

  7. From chemical mapping to pressure temperature deformation micro-cartography: mineralogical evolution and mass transport in thermo-mechanic disequilibrium systems: application to meta-pelites and confinement nuclear waste materials; De l'imagerie chimique a la micro-cartographie Pression-Temperature-Deformation: evolution mineralogique et transport de matiere dans des systemes en desequilibre thermomecanique. Applications aux metapelites et aux materiaux de stockage de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, V. de

    2006-03-15

    The mineralogical composition of metamorphic rocks or industrial materials evolves when they are submitted to thermomechanical disequilibria, i.e. a spatial or temporal pressure and temperature evolution, or chemical disequilibria as variations in redox conditions, pH... For example, during low temperature metamorphic processes, rocks re-equilibrate only partially, and thus record locally thermodynamic equilibria increasing so the spatial chemical heterogeneities. Understanding the P-T evolution of such systems and deciphering modalities of their mineralogical transformation imply to recognize and characterize the size of these local 'paleo-equilibria', and so to have a spatial chemical information at least in 2 dimensions. In order to get this information, microprobe X-ray fluorescence maps have been used. Computer codes have been developed with Matlab to quantify these maps in view of thermo-barometric estimations. In this way, P-T maps of mineral crystallisation were produced using the multi-equilibria thermodynamic technique. Applications on two meta-pelites from the Sambagawa blue-schist belt (Japan) and from the Caledonian eclogitic zone in Spitsbergen, show that quantitative chemical maps are a powerful tool to retrieve the metamorphic history of rocks. From these chemical maps have been derived maps of P-T-time-redox-deformation that allow to characterize P-T conditions of minerals formation, and so, the P-T path of the sample, the oxidation state of iron in the chlorite phase. As a result, we underline the relation between deformation and crystallisation, and propose a relative chronology of minerals crystallisation and deformations. The Fe{sup 3+} content map in chlorite calculated by thermodynamic has also been validated by a {mu}-XANES mapping at the iron K-edge measured at the ESRF (ID24) using an innovative method. Another application relates to an experimental study of clay materials, main components of an analogical model of a nuclear

  8. Formation of Indium-Doped Zinc Oxide Thin Films Using Ultrasonic Spray Pyrolysis: The Importance of the Water Content in the Aerosol Solution and the Substrate Temperature for Enhancing Electrical Transport

    Science.gov (United States)

    Biswal, Rajesh; Castañeda, Luis; Moctezuma, Rosario; Vega-Pérez, Jaime; De La Luz Olvera, María; Maldonado, Arturo

    2012-01-01

    Indium doped zinc oxide [ZnO:In] thin films have been deposited at 430°C on soda-lime glass substrates by the chemical spray technique, starting from zinc acetate and indium acetate. Pulverization of the solution was done by ultrasonic excitation. The variations in the electrical, structural, optical, and morphological characteristics of ZnO:In thin films, as a function of both the water content in the starting solution and the substrate temperature, were studied. The electrical resistivity of ZnO:In thin films is not significantly affected with the increase in the water content, up to 200 mL/L; further increase in water content causes an increase in the resistivity of the films. All films show a polycrystalline character, fitting well with the hexagonal ZnO wurtzite-type structure. No preferential growth in samples deposited with the lowest water content was observed, whereas an increase in water content gave rise to a (002) growth. The surface morphology of the films shows a consistency with structure results, as non-geometrical shaped round grains were observed in the case of films deposited with the lowest water content, whereas hexagonal slices, with a wide size distribution were observed in the other cases. In addition, films deposited with the highest water content show a narrow size distribution. PMID:28817056

  9. Transport modeling of L/H transition in Tokamaks

    International Nuclear Information System (INIS)

    Fuji, Y.; Fukuyama, A.; Itoh, K.; Itoh, S.I.

    1995-01-01

    In order to study the particle transport and the mechanism of the L/H transition in tokamaks, a one-dimensional transport code which describes the toroidal and poloidal plasma rotation as well as the radial electric field has been developed. The neoclassical transport, turbulent transport and ion orbit loss are included. Using a turbulent transport model based on the current diffusive high-n ballooning mode and a fixed temperature profile, the density profile in a steady state and the dependence on the edge temperature are studied. With high edge temperature, the density gradient near the edge becomes steep and a H-mode like density profile is obtained. The preliminary calculation including heat transport is also presented. 10 refs., 3 figs

  10. Two-point model for divertor transport

    International Nuclear Information System (INIS)

    Galambos, J.D.; Peng, Y.K.M.

    1984-04-01

    Plasma transport along divertor field lines was investigated using a two-point model. This treatment requires considerably less effort to find solutions to the transport equations than previously used one-dimensional (1-D) models and is useful for studying general trends. It also can be a valuable tool for benchmarking more sophisticated models. The model was used to investigate the possibility of operating in the so-called high density, low temperature regime

  11. Hadrons at finite temperature

    CERN Document Server

    Mallik, Samirnath

    2016-01-01

    High energy laboratories are performing experiments in heavy ion collisions to explore the structure of matter at high temperature and density. This elementary book explains the basic ideas involved in the theoretical analysis of these experimental data. It first develops two topics needed for this purpose, namely hadron interactions and thermal field theory. Chiral perturbation theory is developed to describe hadron interactions and thermal field theory is formulated in the real-time method. In particular, spectral form of thermal propagators is derived for fields of arbitrary spin and used to calculate loop integrals. These developments are then applied to find quark condensate and hadron parameters in medium, including dilepton production. Finally, the non-equilibrium method of statistical field theory to calculate transport coefficients is reviewed. With technical details explained in the text and appendices, this book should be accessible to researchers as well as graduate students interested in thermal ...

  12. ECRH and electron heat transport in tokamaks

    International Nuclear Information System (INIS)

    Zou, X.L.; Giruzzi, G.; Dumont, R.J.

    2003-01-01

    It has been observed during the ECRH experiments in tokamaks that the shape of the electron temperature profile in stationary regimes is not very sensitive to the ECRH power deposition i.e. the temperature profile remains peaked at the center even though the ECRH power deposition is off-axis. Various models have been invoked for the interpretation of this profile resilience phenomenon: the inward heat pinch, the critical temperature gradient, the Self-Organized Criticality, etc. Except the pinch effect, all of these models need a specific form of the diffusivity in the heat transport equation. In this work, our approach is to solve a simplified time-dependent heat transport equation analytically in cylindrical geometry. The features of this analytical solution are analyzed, in particular the relationship between the temperature profile resilience and the Eigenmode of the physical system with respect to the heat transport phenomenon. Finally, applications of this analytical solution for the determination of the transport coefficient and the polarization of the EC waves are presented. It has been shown that the solution of the simplified transport equation in a finite cylinder is a Fourier-Bessel series. This series represents in fact a decomposition of the heat source in Eigenmode, which are characterized by the Bessel functions of order 0. The physical interpretation of the Eigenmodes is the following: when the heat source is given by a Bessel function of order 0, the temperature profile has exactly the same form as the source at every time. At the beginning of the power injection, the effectiveness of the temperature response is the same for each Eigenmode, and the response in temperature, having the same form as the source, is local. Conversely, in the later phase of the evolution, the effectiveness of the temperature response for each Eigenmode is different: the higher the order, the lower the effectiveness. In this case the response in temperature appears as

  13. Transport properties of inertial confinement fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Issanova, M.K.; Kodanova, S.K.; Ramazanov, T.S. [IETP, Al-Farabi Kazakh National University, Almaty (Kazakhstan); Hoffmann, D.H.H. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)

    2016-06-15

    In this paper the transport properties of non-isothermal dense deuterium-tritium plasmas were studied. Based on the effective interaction potentials between particles, the Coulomb logarithm for a two-temperature nonisothermal dense plasma was obtained. These potentials take into consideration long-range multi-particle screening effects and short-range quantum-mechanical effects in two-temperature plasmas. Transport processes in such plasmas were studied using the Coulomb logarithm. The obtained results were compared with the theoretical works of other authors and with the results of molecular dynamics simulations. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Water-transporting proteins

    DEFF Research Database (Denmark)

    Zeuthen, Thomas

    2010-01-01

    . In the K(+)/Cl(-) and the Na(+)/K(+)/2Cl(-) cotransporters, water is entirely cotransported, while water transport in glucose uniporters and Na(+)-coupled transporters of nutrients and neurotransmitters takes place by both osmosis and cotransport. The molecular mechanism behind cotransport of water...... transport. Epithelial water transport is energized by the movements of ions, but how the coupling takes place is uncertain. All epithelia can transport water uphill against an osmotic gradient, which is hard to explain by simple osmosis. Furthermore, genetic removal of aquaporins has not given support...... to osmosis as the exclusive mode of transport. Water cotransport can explain the coupling between ion and water transport, a major fraction of transepithelial water transport and uphill water transport. Aquaporins enhance water transport by utilizing osmotic gradients and cause the osmolarity...

  15. Physical protection of radioactive material in transport

    International Nuclear Information System (INIS)

    1975-01-01

    Safety in the transport of radioactive material is ensured by enclosing the material, when necessary, in packaging which prevents its dispersal and which absorbs to any adequate extent any radiation emitted by the material. Transport workers, the general public and the environment are thus protected against the harmful effects of the radioactive material. The packaging also serves the purpose of protecting its contents against the effects of rough handling and mishaps under normal transport conditions, and against the severe stresses and high temperatures that could be encountered in accidents accompanied by fires. If the radioactive material is also fissile, special design features are incorporated to prevent any possibility of criticality under normal transport conditions and in accidents. The safe transport requirements are designed to afford protection against unintentional opening of packages in normal handling and transport conditions and against damage in severe accident conditions; whereas the physical protection requirements are designed to prevent intentional opening of packages and deliberate damage. This clearly illustrates the difference in philosophical approach underlying the requirements for safe transport and for physical protection during transport. This difference in approach is, perhaps, most easily seen in the differing requirements for marking of consignments. While safety considerations dictate that packages be clearly labelled, physical protection considerations urge restraint in the use of special labels. Careful consideration must be given to such differences in approach in any attempt to harmonize the safety and physical protection aspects of transport. (author)

  16. Hydrate Technology For Transporting Natural Gas

    OpenAIRE

    Dawe, R. A.

    2003-01-01

    Natural gas hydrate (NGH) is a viable alternative to LNG (Liquefied Natural Gas) or pipelines for the transportation of natural gas from source to demand. It involves three stages: production, transportation and re-gasification. The production of the hydrate occurs at pressures >50 bar at temperatures ~10oC in the presence of water and natural gas (particularly methane, ethane, propane). Transportation is by insulated bulk carrier at around –5 oC and atmospheric pressure or 0 oC at 10 bar, an...

  17. Performance Analysis of Solution Transportation Absorption Chiller

    Science.gov (United States)

    Kiani, Behdad; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    Thermally activated advanced absorption cycles are considered promising candidates to replace CFCs, HCFCs and HFCs for residential and commercial applications. In such absorption systems, it is desirable to utilize the waste heat from industries for heating and cooling applications in commercial and residential sectors. For this purpose, it is necessary to transport energy over some distance because the waste heat source and demand are generally located apart from each other. Transportation of steam, hot water or chilled water requires high construction costs for insulation. There is an efficient method of energy transportation using absorption system called “ Solution Transportation Absorption System (STA)”. The solution is transported at an ambient temperature so that tube-insulations not required. This paper shows the simulation of the abovementioned system and the optimal result, using mathematical optimization. The optimum system with industry‧s waste heat utilization is obtained. At the end, the effect on the pollution emission and energy conservation is obtained.

  18. Modelling of Transport Phenomena

    OpenAIRE

    K., Itoh; S.-I., Itoh; A., Fukuyama

    1993-01-01

    In this review article, we discuss key features of the transport phenomena and theoretical modelling to understand them. Experimental observations have revealed the nature of anomalous transport, i.e., the enhancement of the transport coefficients by the gradients of the plasma profiles, the pinch phenomena, the radial profile of the apomalous transport coefficients, the variation of the transport among the Bohm diffusion, Pseudo-classical confinement, L-mode and variety of improved confineme...

  19. Magnetic type transportation system

    International Nuclear Information System (INIS)

    Kobama, Masao.

    1981-01-01

    Purpose: To enable automatic transportation of nuclear substances with optional setting for the transportation distance, even for a long distance, facilitating the automation of the transportation and decreasing the space for the installation of a direction converging section of the transporting path. Constitution: A transporting vehicle having a pair of permanent magnets or ferromagnetic bodies mounted with a predetermined gap to each other along the transporting direction is provided in the transporting path including a bent direction change section for transporting specimens such as nuclear materials, and a plurality of driving vehicles having permanent magnets or ferromagnetic bodies for magnetically attracting the transporting vehicle from outside of the transporting path are arranged to the outside of the transporting path. At least one of the driving vehicles is made to run along the transporting direction of the transporting path by a driving mechanism incorporating running section such as an endless chain to drive the transportation vehicle, and the transporting vehicle is successively driven by each of the driving mechanisms. (Kawakami, Y.)

  20. Charge Transport in LDPE Nanocomposites Part II—Computational Approach

    Directory of Open Access Journals (Sweden)

    Anh T. Hoang

    2016-03-01

    Full Text Available A bipolar charge transport model is employed to investigate the remarkable reduction in dc conductivity of low-density polyethylene (LDPE based material filled with uncoated nanofillers (reported in the first part of this work. The effect of temperature on charge transport is considered and the model outcomes are compared with measured conduction currents. The simulations reveal that the contribution of charge carrier recombination to the total transport process becomes more significant at elevated temperatures. Among the effects caused by the presence of nanoparticles, a reduced charge injection at electrodes has been found as the most essential one. Possible mechanisms for charge injection at different temperatures are therefore discussed.