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Sample records for sns diagnostics summary

  1. STATUS OF VARIOUS SNS DIAGNOSTIC SYSTEMS

    SciTech Connect

    Blokland, Willem; Purcell, J David; Patton, Jeff; Pelaia II, Tom; Sundaram, Madhan; Pennisi, Terry R

    2007-01-01

    The Spallation Neutron Source (SNS) accelerator systems are ramping up to deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. Enhancements or additions have been made to several instrument systems to support the ramp up in intensity, improve reliability, and/or add functionality. The Beam Current Monitors now support increased rep rates, the Harp system now includes charge density calculations for the target, and a new system has been created to collect data for the beam accounting and present the data over the web and to the operator consoles. The majority of the SNS beam instruments are PC-based and their configuration files are now managed through the Oracle relational database. A new version for the wire scanner software was developed to add features to correlate the scan with beam loss, parking in the beam, and measuring the longitudinal beam current. This software is currently being tested. This paper also includes data from the selected instruments.

  2. Experience with the SNS LabVIEW/EPICS-Based Diagnostics Instruments

    SciTech Connect

    Blokland, Willem; Assadi, Saeed

    2004-11-10

    The SNS Diagnostics Group uses rack-mounted PCs running LabVIEW and EPICS to implement its instruments as network attached devices. Many of these instruments, such as wire scanners and beam position monitors, come from the partner labs. The final integration and testing is done at SNS. We have now gone through several commissioning runs with success. This paper describes the integration, the commissioning, and the physics performance of the devices.

  3. Summary Report on Synchronization, Diagnostics and Instrumentation

    SciTech Connect

    Arne Freyberger

    2005-03-19

    The proceedings of Working Group 4 of the 2005 Energy Recovery Linac (ERL) workshop are summarized. Working Group 4 dealt with the challenging topic of beam diagnostics for ERL machines. Energy Recovery Linacs represent a challenge for beam diagnostics from several perspectives; invasive versus non-invasive diagnostics, longitudinal and transverse beam diagnostics, overall machine timing/synchronization and machine protection. Beam diagnostics for an ERL can benefit strongly from the experience at third generation light sources, recirculating linacs and presently operating ERLs. During the workshop there were presentations from all these communities, representing a large range operation experience in beam diagnostics. A brief summary Working Group 4 discussion is presented in this paper.

  4. SNS application programming plan.

    SciTech Connect

    Chu, C. M.; Galambos, J. D.; Wei, J.; Allen, C.; McGehee, P. M.; Malitsky, N.

    2001-01-01

    The plan for Spallation Neutron Source accelerator physics application programs is presented. These high level applications involve processing and managing information from the diagnostic instruments, the machine control system, models and static databases and will be used to investigate and control beam behavior. Primary components include an SNS global database and Java-based XAL Application Toolkit. A key element in the SNS application programs is time synchronization of data used in these applications, due to the short pulse (1 ms), pulsed (60 Hz) nature of the device. The data synchronization progress is also presented.

  5. Active beam position stabilization of pulsed lasers for long-distance ion profile diagnostics at the Spallation Neutron Source (SNS).

    PubMed

    Hardin, Robert A; Liu, Yun; Long, Cary; Aleksandrov, Alexander; Blokland, Willem

    2011-02-14

    A high peak-power Q-switched laser has been used to monitor the ion beam profiles in the superconducting linac at the Spallation Neutron Source (SNS). The laser beam suffers from position drift due to movement, vibration, or thermal effects on the optical components in the 250-meter long laser beam transport line. We have designed, bench-tested, and implemented a beam position stabilization system by using an Ethernet CMOS camera, computer image processing and analysis, and a piezo-driven mirror platform. The system can respond at frequencies up to 30 Hz with a high position detection accuracy. With the beam stabilization system, we have achieved a laser beam pointing stability within a range of 2 μrad (horizontal) to 4 μrad (vertical), corresponding to beam drifts of only 0.5 mm × 1 mm at the furthest measurement station located 250 meters away from the light source.

  6. SNS BEAM COMMISSIONING TOOLS AND EXPERIENCE

    SciTech Connect

    Shishlo, Andrei P; Galambos, John D

    2008-01-01

    The Spallation Neutron Source (SNS) successfully met the primary construction project completion milestones in April 2006. An important ingredient of this successful commissioning was the development and use of software tools. With the increasing digitalization of beam diagnostics and increasing complexity of Integrated Control Systems of large accelerators, the need for high level software tools is critical for smooth commissioning. At SNS a special Java based infrastructure called XAL was prepared for beam commissioning. XAL provides a hierarchal view of the accelerator, is data base configured, and includes a physics model of the beam. This infrastructure and individual applications development along with a historical time line of the SNS commissioning will be discussed.

  7. Summary I - Accelerator Ion sources, Fundamentals and Diagnostics

    SciTech Connect

    Moehs, Douglas P.

    2007-08-10

    The 11th International Symposium on the Production and Neutralization of Negative Ions and Beams was held in Santa Fe, New Mexico on September 12-15, 2006 and was hosted by Los Alamos National Laboratory. This summary covers the first three oral sessions of the symposium.

  8. Diagnostic guidelines for bipolar disorder: a summary of the International Society for Bipolar Disorders Diagnostic Guidelines Task Force Report.

    PubMed

    Ghaemi, S Nassir; Bauer, Michael; Cassidy, Frederick; Malhi, Gin S; Mitchell, Philip; Phelps, James; Vieta, Eduard; Youngstrom, Eric

    2008-02-01

    The Diagnostic Guidelines Task Force of the International Society for Bipolar Disorders (ISBD) presents in this document and this special issue a summary of the current nosological status of bipolar illness, a discussion of possible revisions to current DSM-IV and ICD-10 definitions, an examination of the relevant literature, explication of areas of consensus and dissensus, and proposed definitions that might guide clinicians in the most valid approach to diagnosis of these conditions given the current state of our knowledge.

  9. SNS programming environment user's guide

    SciTech Connect

    Tennille, G.M.; Howser, L.M.; Humes, D.C.; Cronin, C.K.; Bowen, J.T.; Drozdowski, J.M.; Utley, J.A.; Flynn, T.M.; Austin, B.A.

    1992-02-01

    The computing environment is briefly described for the Supercomputing Network Subsystem (SNS) of the Central Scientific Computing Complex of NASA Langley. The major SNS computers are a CRAY-2, a CRAY Y-MP, a CONVEX C-210, and a CONVEX C-220. The software is described that is common to all of these computers, including: the UNIX operating system, computer graphics, networking utilities, mass storage, and mathematical libraries. Also described is file management, validation, SNS configuration, documentation, and customer services.

  10. SNS programming environment user's guide

    NASA Technical Reports Server (NTRS)

    Tennille, Geoffrey M.; Howser, Lona M.; Humes, D. Creig; Cronin, Catherine K.; Bowen, John T.; Drozdowski, Joseph M.; Utley, Judith A.; Flynn, Theresa M.; Austin, Brenda A.

    1992-01-01

    The computing environment is briefly described for the Supercomputing Network Subsystem (SNS) of the Central Scientific Computing Complex of NASA Langley. The major SNS computers are a CRAY-2, a CRAY Y-MP, a CONVEX C-210, and a CONVEX C-220. The software is described that is common to all of these computers, including: the UNIX operating system, computer graphics, networking utilities, mass storage, and mathematical libraries. Also described is file management, validation, SNS configuration, documentation, and customer services.

  11. SNS Cryogenic Systems Commissioning

    SciTech Connect

    D. Hatfield; F. Casagrande; I. Campisi; P. Gurd; M. Howell; D. Stout; H. Strong; D. Arenius; J. Creel; K. Dixon; V. Ganni; and P. Knudsen

    2005-08-29

    The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented.

  12. The SNS RFQ Commissioning

    SciTech Connect

    Ratti, A.; Ayers, J.; Doolittle, L.; DiGennaro, R.; Gough, R.A.; Hoff, M.; Keller, R.; MacGill, J.; Staples, J.; Thomae, R.; Virostek, S.; Yourd, R.; Aleksandrov, A.

    2002-08-16

    LBNL has built for the Spallation Neutron Source (SNS) project a 402.5 MHz RFQ that is designed to accelerate up to 60 mA H{sup -} from 65 keV to 2.5 MeV [1]. A one millisecond pulse length at 60 Hz provides a 6% duty factor. The RFQ has now been built, conditioned at full duty factor and tested with beam. This paper will present results from the final installation, tuning and beam commissioning. Beam measurements include acceleration and transport efficiencies and transverse emittances. The LEBT optics were tuned for best results. Performance testing of the RF power distribution is also discussed here.

  13. SNS Cryogenic Systems Commissioning

    NASA Astrophysics Data System (ADS)

    Hatfield, D.; Casagrande, F.; Campisi, I.; Gurd, P.; Howell, M.; Stout, D.; Strong, H.; Arenius, D.; Creel, J.; Dixon, K.; Ganni, V.; Knudsen, P.

    2006-04-01

    The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented.

  14. Commissioning Experience of SNS

    SciTech Connect

    Plum, Michael A

    2007-07-01

    The Spallation Neutron Source accelerator complex consists of a 2.5 MeV H{sup -} front-end injector system, a 186 MeV normal-conducting linear accelerator, a 1 GeV superconducting linear accelerator, an accumulator ring, and associated beam transport lines. The linac was commissioned in five discrete runs, starting in 2002 and completed in 2005. The accumulator ring and associated beam transport lines were commissioned in two runs in January-February and April 2006. With the completed commissioning of the SNS accelerator, the facility has begun initial low-power operations. In the course of beam commissioning, most beam performance parameters and beam intensity goals have been achieved at low duty factor. A number of beam dynamics measurements have been performed, including emittance evolution, transverse coupling in the ring, beam instability thresholds, and beam distributions on the target. The commissioning results, achieved beam performance and initial operating experience of the SNS linac will be presented.

  15. SNS second target station moderator performance update

    SciTech Connect

    Gallmeier, Franz X.

    2010-03-08

    In its first years of operations of its first target station, the Spallation Neutron Source (SNS) is working towards a facility upgrade by a megawatt-class second target station operated at 20 Hz repetition rate, which is intended to complement the existing ORNL neutron sources, the first SNS target station and the HFIR reactor, with high-intensity cold neutron beams.The first round of optimization calculations converged on larger-volume cylindrical para-hydrogen moderators placed in wing configuration on top and bottom of a flat mercury target, pre-moderated by layers of ambient water and surrounded by beryllium reflector. The metric of these optimization calculations was time-averaged and energy-integrated neutron brightness below 5 meV with the requirement to be able to serve 20 ports with neutrons. A summary of these calculations will be given including lessons learned from the variety of simulated configurations and detailed neutron performance characteristics like spectral intensities, emission time distributions, local variations of moderator brightness at the viewed areas, and sensitivity of the optimization metric to optimized parameters for the most promising configuration.

  16. The stationarity paradigm revisited: Hypothesis testing using diagnostics, summary metrics, and DREAM(ABC)

    NASA Astrophysics Data System (ADS)

    Sadegh, Mojtaba; Vrugt, Jasper A.; Xu, Chonggang; Volpi, Elena

    2015-11-01

    Many watershed models used within the hydrologic research community assume (by default) stationary conditions, that is, the key watershed properties that control water flow are considered to be time invariant. This assumption is rather convenient and pragmatic and opens up the wide arsenal of (multivariate) statistical and nonlinear optimization methods for inference of the (temporally fixed) model parameters. Several contributions to the hydrologic literature have brought into question the continued usefulness of this stationary paradigm for hydrologic modeling. This paper builds on the likelihood-free diagnostics approach of Vrugt and Sadegh and uses a diverse set of hydrologic summary metrics to test the stationary hypothesis and detect changes in the watersheds response to hydroclimatic forcing. Models with fixed parameter values cannot simulate adequately temporal variations in the summary statistics of the observed catchment data, and consequently, the DREAM(ABC) algorithm cannot find solutions that sufficiently honor the observed metrics. We demonstrate that the presented methodology is able to differentiate successfully between watersheds that are classified as stationary and those that have undergone significant changes in land use, urbanization, and/or hydroclimatic conditions, and thus are deemed nonstationary.

  17. Summary

    NASA Astrophysics Data System (ADS)

    Habing, H.

    2004-07-01

    Summaries of conferences consist of subjective views of the reviewer, on what he remarked, of what he thought was important. And yet some of these remarks may be of interest to all participants. The event called "inspiration" may happen when scientist A gets an idea because of a brilliant or of stupid remark she heard when scientist B gave a summary. So, what is a good review? A review that broadens the perspective of at least some people in the audience. I hope that my attempt works. Let's see.

  18. Transverse beam stability measurement and analysis for the SNS accumulator ring

    NASA Astrophysics Data System (ADS)

    Xie, Zaipeng; Deibele, Craig; Schulte, Michael J.; Hu, Yu-Hen

    2015-07-01

    A field-programmable gate array (FPGA)-based transverse feedback damper system was implemented in the Spallation Neutron Source (SNS) accumulator ring with the intention to stabilize the electron-proton (e-p) instability in the frequency range of 1-300 MHz. The transverse feedback damper could also be used as a diagnostic tool by measuring the beam transfer function (BTF). An analysis of the BTF measurements provides the stability diagram for the production beam at SNS. This paper describes the feedback damper system and its setup as the BTF diagnostic tool. Experimental BTF results are presented and beam stability is analyzed by use of the BTF measurements for the SNS accumulator ring.

  19. Patient radiation exposure in diagnostic radiology examinations: an overview. Summary report

    SciTech Connect

    Burkhart, R.L.

    1983-08-01

    The report surveys the published data on entrance skin exposure received by patients during diagnostic radiology examinations. It provides a reference source to aid radiology facilities in determining whether the amount of exposure received by their patients is appropriate for the diagnostic procedures employed.

  20. INSTABILITY ISSUES AT THE SNS STORAGE RING

    SciTech Connect

    ZHANG,S.Y.

    1999-06-28

    The impedance and beam instability issues of the SNS storage ring is reviewed, and the effort toward solutions at the BNL is reported. Some unsettled issues are raised, indicating the direction of planned works.

  1. ICTP-IAEA Workshop on Dense Magnetized Plasma and Plasma Diagnostics: an executive summary

    NASA Astrophysics Data System (ADS)

    Gribkov, V. A.; Mank, G.; Markowicz, A.; Miklaszewski, R.; Tuniz, C.; Crespo, M. L.

    2011-12-01

    The Workshop on Dense Magnetized Plasma and Plasma Diagnostics was held from 15 to 26 November 2010 at the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy. It was attended by 60 participants, including 15 lecturers, 2 tutors and 37 trainees, representing 25 countries.

  2. A COMPACTRIO-BASED BEAM LOSS MONITOR FOR THE SNS RF TEST CAVE

    SciTech Connect

    Blokland, Willem; Armstrong, Gary A

    2009-01-01

    An RF Test Cave has been built at the Spallation Neutron Source (SNS) to be able to test RF cavities without interfering the SNS accelerator operations. In addition to using thick concrete wall to minimize radiation exposure, a Beam Loss Monitor (BLM) must abort the operation within 100 usec when the integrated radiation within the cave exceeds a threshold. We choose the CompactRIO platform to implement the BLM based on its performance, cost-effectiveness, and rapid development. Each in/output module is connected through an FPGA to provide point-by-point processing. Every 10 usec the data is acquired analyzed and compared to the threshold. Data from the FPGA is transferred using DMA to the real-time controller, which communicates to a gateway PC to talk to the SNS control system. The system includes diagnostics to test the hardware and integrates the losses in real-time. In this paper we describe our design, implementation, and results

  3. Beam diagnostics, collimation, injection/extraction, targetry, accidents and commissioning: Working group C&G summary report

    SciTech Connect

    Mokhov, N.V.; Hasegawa, K.; Henderson, S.; Schmidt, R.; Tomizawa, M.; Wittenburg, K.; /DESY

    2006-11-01

    The performance of accelerators with high beam power or high stored beam energy is strongly dependent on the way the beam is handled, how beam parameters are measured and how the machine is commissioned. Two corresponding working groups have been organized for the Workshop: group C ''Beam diagnostics, collimation, injection/extraction and targetry'' and group G ''Commissioning strategies and procedures''. It has been realized that the issues to be discussed in these groups are interlaced with the participants involved and interested in the above topics, with an extremely important subject of beam-induced accidents as additional topic. Therefore, we have decided to combine the group sessions as well as this summary report. Status, performance and outstanding issues of each the topic are described in the sections below, with additional observations and proposals by the joint group at the end.

  4. Summary of Glaucoma Diagnostic Testing Accuracy: An Evidence-Based Meta-Analysis

    PubMed Central

    Ahmed, Saad; Khan, Zainab; Si, Francie; Mao, Alex; Pan, Irene; Yazdi, Fatemeh; Tsertsvadze, Alexander; Hutnik, Cindy; Moher, David; Tingey, David; Trope, Graham E.; Damji, Karim F.; Tarride, Jean-Eric; Goeree, Ron; Hodge, William

    2016-01-01

    Background New glaucoma diagnostic technologies are penetrating clinical care and are changing rapidly. Having a systematic review of these technologies will help clinicians and decision makers and help identify gaps that need to be addressed. This systematic review studied five glaucoma technologies compared to the gold standard of white on white perimetry for glaucoma detection. Methods OVID® interface: MEDLINE® (In-Process & Other Non-Indexed Citations), EMBASE®, BIOSIS Previews®, CINAHL®, PubMed, and the Cochrane Library were searched. A gray literature search was also performed. A technical expert panel, information specialists, systematic review method experts and biostatisticians were used. A PRISMA flow diagram was created and a random effect meta-analysis was performed. Results A total of 2,474 articles were screened. The greatest accuracy was found with frequency doubling technology (FDT) (diagnostic odds ratio (DOR): 57.7) followed by blue on yellow perimetry (DOR: 46.7), optical coherence tomography (OCT) (DOR: 41.8), GDx (DOR: 32.4) and Heidelberg retina tomography (HRT) (DOR: 17.8). Of greatest concern is that tests for heterogeneity were all above 50%, indicating that cutoffs used in these newer technologies were all very varied and not uniform across studies. Conclusions Glaucoma content experts need to establish uniform cutoffs for these newer technologies, so that studies that compare these technologies can be interpreted more uniformly. Nevertheless, synthesized data at this time demonstrate that amongst the newest technologies, OCT has the highest glaucoma diagnostic accuracy followed by GDx and then HRT. PMID:27540437

  5. Practice Bulletin No. 162 Summary: Prenatal Diagnostic Testing for Genetic Disorders.

    PubMed

    2016-05-01

    Prenatal genetic diagnostic testing is intended to determine, with as much certainty as possible, whether a specific genetic disorder or condition is present in the fetus. In contrast, prenatal genetic screening is designed to assess whether a patient is at increased risk of having a fetus affected by a genetic disorder. Originally, prenatal genetic testing focused primarily on Down syndrome (trisomy 21), but now it is able to detect a broad range of genetic disorders. Although it is necessary to perform amniocentesis or chorionic villus sampling (CVS) to definitively diagnose most genetic disorders, in some circumstances, fetal imaging with ultrasonography, echocardiography, or magnetic resonance imaging may be diagnostic of a particular structural fetal abnormality that is suggestive of an underlying genetic condition.The objective of prenatal genetic testing is to detect health problems that could affect the woman, fetus, or newborn and provide the patient and her obstetrician-gynecologist or other obstetric care provider with enough information to allow a fully informed decision about pregnancy management. Prenatal genetic testing cannot identify all abnormalities or problems in a fetus, and any testing should be focused on the individual patient's risks, reproductive goals, and preferences. It is important that patients understand the benefits and limitations of all prenatal screening and diagnostic testing, including the conditions for which tests are available and the conditions that will not be detected by testing. It also is important that patients realize that there is a broad range of clinical presentations, or phenotypes, for many genetic disorders and that results of genetic testing cannot predict all outcomes. Prenatal genetic testing has many benefits, including reassuring patients when results are normal, identifying disorders for which prenatal treatment may provide benefit, optimizing neonatal outcomes by ensuring the appropriate location for

  6. Summary and early findings from a second generation information monitoring and diagnostic system

    SciTech Connect

    Piette, Mary Ann; Kinney, Satkartar; Bourassa, Norman; Kinney, Kristopher L.; Shockman, Christine

    2003-04-02

    Private sector commercial office buildings are challenging environments for energy efficiency projects. This challenge is related to the complexity of business environments that involve ownership, operation, and tenant relationships. This research project was developed to examine the environment for building operations and identify causes of inefficient use of energy related to technical and organizational issues. This paper discusses a second-generation Information Monitoring and Diagnostic System (IMDS) installed at a leased office building in Sacramento, California. The underlying principle of this project is that high quality building performance data can help show where energy is being used and how buildings systems actually perform. Such data are an important first step toward improving building energy efficiency. This project has demonstrated that the IMDS is valuable to the building operators at the Sacramento site. The building operators not only accept the technology, but it has become the core of their day-to-day building control concepts. One objective of this project was to evaluate the costs and benefits of the IMDS. The system cost about $0.70 per square foot, which includes the design, hardware, software, and installation, which is about 30% less than the previous IMDS in San Francisco. A number of operational problems have been identified with the IMDS.

  7. Establishing an Ongoing Binational U.S.-Mexico Border Climate Diagnostic Summary: Developing a Prototype and Navigating the Institutional Landscape

    NASA Astrophysics Data System (ADS)

    Garfin, G.; Varady, R.; Morehouse, B.; Wilder, M.; Crawford, B.

    2007-05-01

    In its eighth report to the President and Congress of the United States, the Good Neighbor Environmental Board (an independent federal advisory committee, that advises the President and Congress on environmental practices and infrastructure needs along the U.S. border with Mexico) noted that management of water resources issues along the U.S. border with Mexico would be aided by data and information sharing. They encouraged agencies and institutions to make data accessible, and to exchange data and information, even on a limited or ad hoc basis, in order to build trust and the capacity for managers and staff on both sides of the border to collaborate and work together to solve problems of mutual interest. Although climate is merely one factor affecting decision makers, it can often be the "straw that breaks the camel's back." Along the arid and semiarid U.S. border with Mexico, population growth, industrialization, increasing water consumption, and other factors have exacerbated societal vulnerability to naturally occurring persistent climate phenomena, such as drought. In 2006, scientists from institutions in the U.S. and Mexico agreed to collaborate to address decision makers' pressing needs for climate information, by developing a climate diagnostic and outlook product in a format usable and easily accessible by managers and policy makers. The Border Climate Summary (Resumen del Climate de la Frontera), modeled after monthly climate newsletters produced in the U.S., provides a tangible and simple information tool to strengthen the basic capacity for climate information to be usefully incorporated into decision processes. The Summary provides forecasts and value-added information on temperature, precipitation, and drought within the region. However, in order for the Summary to be effective at reaching its intended audiences, collaborators must break through barriers posed by regulatory and institutional control. They must also identify key insertion points for

  8. Application of optical emission spectroscopy for the SNS H- ion source plasma studies

    NASA Astrophysics Data System (ADS)

    Han, B. X.; Stockli, M. P.; Welton, R. F.; Murray, S. N.; Pennisi, T. R.; Santana, M.

    2015-04-01

    The SNS H- ion source is a dual-frequency RF-driven (13.56-MHz low power continuous RF superimposed by 2-MHz high power pulsed RF with ˜1.0 ms pulse length at 60 Hz), Cs-enhanced ion source. This paper discusses the applications of optical emission spectroscopy for the ion source plasma conditioning, cesiation, failure diagnostics, and studies of plasma build-up and outage issues.

  9. SNS Emittance Scanner, Increasing Sensitivity and Performance through Noise Mitigation ,Design, Implementation and Results

    SciTech Connect

    Pogge, J.

    2006-11-20

    The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The SNS MEBT Emittance Harp consists of 16 X and 16 Y wires, located in close proximity to the RFQ, Source, and MEBT Choppers. Beam Studies for source and LINAC commissioning required an overall increase in sensitivity for halo monitoring and measurement, and at the same time several severe noise sources had to be effectively removed from the harp signals. This paper is an overview of the design approach and techniques used in increasing gain and sensitivity while maintaining a large signal to noise ratio for the emittance scanner device. A brief discussion of the identification of the noise sources, the mechanism for transmission and pick up, how the signals were improved and a summary of results.

  10. nEDM at SNS

    SciTech Connect

    Clayton, Steven

    2014-07-30

    This PowerPoint presentation covered the following topics: Overview; participants in the collaboration; the experimental method and Free Precession Method descriptions; and then experimental design elements, ending with a summary. A new nEDM experiment is under development with a goal sensitivity 90% CL σd < (3-5) x 10-28 e-cm in 300 live-days; Free precession method: SQUIDS to read out the 3He precession frequency, Scintillation signal for the n relative precession frequency; Dressed spin method: Strong RF field to match n and 3He effective magnetic moments; Modulation/feedback of dressing parameter based on scintillation signal; and, Ongoing development/demonstration of many aspects of the apparatus (a subset was shown here).

  11. PROGRESS IN DESIGN OF THE SNS LINAC

    SciTech Connect

    R. HARDEKOPF

    2000-11-01

    The Spallation Neutron Source (SNS) is a six-laboratory collaboration to build an intense pulsed neutron facility at Oak Ridge, TN. The linac design has evolved from the conceptual design presented in 1997 to achieve higher initial performance and to incorporate desirable upgrade features. The linac will initially produce 2-MW beam power using a combination of radio-frequency quadruple (RFQ) linac, drift-tube linac (DTL), coupled-cavity linac (CCL), and superconducting-cavity linac (SCL). Designs of each of these elements support the high peak intensity and high quality beam required for injection into the SNS accumulator ring. This paper will trace the evolution of the linac design, the cost and performance factors that drove architecture decisions, and the progress made in the R&D program.

  12. 2-K pump down studies at SNS

    NASA Astrophysics Data System (ADS)

    Howell, M.; Casagrande, F.; DeGraff, B.; Ganni, V.; Kim, S.-H.; Knudsen, P.; Martinez, M.; Morris, B.; Neustadt, T.; Norton, R.; Scanlon, C.; Strong, H.; Vandygriff, D.; Wilson, G.

    2015-12-01

    The Spallation Neutron Source (SNS) linear accelerator (LINAC) consists of 81 superconducting radio frequency (SRF) cavities cooled to 2.1 K by a cryogenic refrigeration system. The 2-K cold box consists of four stages of cold compressors with liquid nitrogen cooled variable speed motors. Transitioning from 4.5-K operation to 2.1-K operation in the cryomodules involves pumping the cryomodules down from approximately 1 bar to 0.040 bar. This effort is conducted through the use of several sequences developed as a collaborative effort between Thomas Jefferson National Accelerator Facility (TJNAF) and SNS personnel during the original commissioning of the SNS cryogenic system. Over the last ten years, multiple lessons have been learned about VFD behavior, thermal stability, procedural development and refining the sequences. From 2012 to 2014, there were multiple pump down iterations that were not successful. Studies have been conducted to determine the cause of these unsuccessful iterations. The results of these studies including components replaced and aspects that have not yet been solved are presented in this paper. Future plans to refine the sequence and determine the cause of unsuccessful pump downs will also be presented.

  13. LONGITUDINAL SPACE CHARGE EFFECT FOR SNS

    SciTech Connect

    ZHANG,S.Y.; WENG,W.T.

    1998-06-22

    One of performance requirements of the Spallation Neutron Source (SNS) is to keep the uncontrolled beam loss in the storage ring to less than 2 x 10{sup {minus}4} per pulse. For 2 MW SNS, the maximum beam intensity is N = 2 x 10{sup 14} protons per ring. Since the bunch lengthening has impact on both the extraction beam loss and the lowering of e-p instability threshold, the longitudinal space charge effect requires attentions. Such a space charge effect has been studied both analytically and using computer simulations. The longitudinal space charge effect, which is a defocusing force below transition, is a plausible source of the bunch leakage. In this article, the total RF potential, which takes into account the space charge effect together with the RF power, is used to provide analytical predictions for the bunch lengthening. The prediction is confirmed by the computer simulation. It is found that for 2 MW SNS storage ring, the longitudinal space charge induced bunch leakage into the interbunch gap is not significant. Therefore, corrections to the longitudinal space charge impedance, such as the proposed ferrite insertion in the PSR ring, are probably not necessary. Applying an RF voltage ramping from 20 KV to 40 KV during the multiturn injection can further cut the bunch leakage to a negligible degree. The same approach applied to the PSR shows that the longitudinal space charge effect does cause sizable bunch leakage at the intensity limit encountered there.

  14. SNS EXTRACTION FAST KICKER SYSTEM DEVELOPMENT.

    SciTech Connect

    ZHANG,W.; SANDBERG,J.; LAMBIASE,R.; LEE,Y.Y.; LOCKEY,R.; MI,J.; NEHRING,T.; PAI,C.; TSOUPAS,N.; TUOZZOLO,J.; WARBURTON,D.; WEI,J.; RUST,K.; CUTLER,R.

    2003-06-15

    The SNS Extraction Fast Kicker System is a very high power, high repetition rate pulsed power system. It was design and developed at Brookhaven National Laboratory. This system will consist of fourteen identical high voltage, high current modulators, and their auxiliary control and charging systems. The modulators will drive fourteen extraction magnet sections located inside of the SNS accumulator ring. The required kicker field rise time is 200 ns, a pulse flattop of 700 ns, a pulse repetition rate of 60 pulse-per-second. A 2500 Ampere per modulator output is required to reach the extraction kicker magnetic field strength. This design features a Blumlein Pulse-Forming-Network based topology, a low beam impedance termination, a fast current switching thyratron, and low inductance capacitor banks. It has a maximum charging voltage of 50kV, an open circuit output of 100kV, and a designed maximum pulsed current output of 4kA per modulator. The overall system output will be multiple GVA with 60 Pulse-per-second repetition rate. A prototype modulator has been successfully built and tested well above the SNS requirement. The modulator system production is in progress.

  15. Results of the SNS front end commissioning at Berkeley Lab

    SciTech Connect

    Ratti, A.; Ayers, J.J.; Doolittle, L.; Greer, J.B.; Keller, R.; Lewis, S.; Lionberger, C.; Monroy, M.; Pruyn, J.; Staples, J.W.; Syversrude, D.; Thomae, R.; Virostek, S.; Aleksandrov, A.; Shea, T.; SNS Accelerator Physics Group; SNS Beam Diagnostics Collaboration

    2002-08-16

    The Front-End Systems (FES) for the Spallation Neutron Source (SNS) project comprise an rf-driven H{sup -} ion source, an electrostatic 2-lens LEBT, a 2.5 MeV RFQ, followed by a 14-quadrupole, 4-rebuncher MEBT including traveling-wave fast choppers. The nominal 2.5 MeV H{sup -} beam has a current of 38 mA at a repetition rate of 60 Hz and 1 ms pulse length, for a macro duty-factor of 6%, and is chopped at a rate of approximately 1 MHz with a mini duty-factor of 68%. The normalized rms beam emittance at the MEBT exit, matching the first tank of a 402.5 MHz Alvarez linac, is measured to be approximately 0.3 {pi} mm mrad. Diagnostic elements include wire scanners, BPMs, fast current monitors, a slit-harp emittance device and RFQ field monitoring probes. The results of the beam commissioning and the operation of the RFQ and diagnostic instrumentation are reported. The entire FES was shut down at LBNL at the end of May 2002 and will be recommissioned at ORNL prior to installation of the drift-tube linac.

  16. Modulator considerations for the SNS RF system

    SciTech Connect

    Tallerico, P.J.; Reass, W.A.

    1998-12-31

    The Spallation Neutron Source (SNS) is an intense neutron source for neutron scattering experiments. The project is in the research stage, with construction funding beginning next year. The SNS is comprised of an ion source, a 1,000 MeV, H{sup {minus}} linear accelerator, an accumulator ring, a neutron producing target, and experimental area to utilize the scattering of the neutrons. The linear accelerator is RF driven, and the peak beam current is 27 mA and the beam duty factor is 5.84%. The peak RF power required is 104 MW, and the H{sup {minus}} beam pulse length is 0.97 ms at a 60 Hz repetition rate. The RF pulses must be about 0.1 ms longer than the beam pulses, due to the Q of the accelerating cavities, and the time required to establish control of the cavity fields. The modulators for the klystrons in this accelerator are discussed in this paper. The SNS is designed to be expandable, so the beam power can be doubled or even quadrupled in the future. One of the double-power options is to double the beam pulse length and duty factor. The authors are specifying the klystrons to operate in this twice-duty-factor mode, and the modulator also should be expandable to 2 ms pulses at 60 Hz. Due to the long pulse length and low RF frequency of 805 MHz, the klystron power is specified at 2.5 MW peak, and the RF system will have 56 klystrons at 805 MHz, and three 1.25 MW peak power klystrons at 402.5 MHz for the low energy portion of the accelerator. The low frequency modulators are conventional floating-deck modulation anode control systems.

  17. Haematological cancers: improving outcomes. A summary of updated NICE service guidance in relation to Specialist Integrated Haematological Malignancy Diagnostic Services (SIHMDS).

    PubMed

    Snowden, John A; O'Connell, Susan; Hawkins, James; Dalley, Chris; Jack, Andrew; Mannari, Deepak; McNamara, Chris; Scott, Mike; Shenton, Geoff; Soilleux, Elizabeth; Macbeth, Fergus

    2017-04-07

    Haematological malignancies are a diverse group of cancers that affect the blood, bone marrow and lymphatic systems. Laboratory diagnosis of haematological malignancies is dependent on combining several technologies, including morphology, immunophenotyping, cytogenetics and molecular genetics correlated clinical details and classification according to the current WHO guidelines. The concept of the Specialised Integrated Haematological Malignancy Diagnostic Services (SIHMDS) has evolved since the UK National Institute for Health and Care Excellence (NICE) Improving Outcomes Guidance (IOG) in 2003 and subsequently various models of delivery have been established. As part of the 2016 update to the NICE IOG, these models were systematically evaluated and recommendations produced to form the basis for quality standards for future development of SIHMDS. We provide a summary of the systematic review and recommendations. Although the recommendations pertain to the UK National Health Service (NHS), they have relevance to the modern delivery of diagnostic services internationally.

  18. A facile inexpensive route for SnS thin film solar cells with SnS2 buffer

    NASA Astrophysics Data System (ADS)

    Gedi, Sreedevi; Minna Reddy, Vasudeva Reddy; Pejjai, Babu; Jeon, Chan-Wook; Park, Chinho; K. T., Ramakrishna Reddy

    2016-05-01

    Environment-friendly SnS based thin film solar cells with SnS2 as buffer layer were successfully fabricated from a facile inexpensive route, chemical bath deposition (CBD). Layer studies revealed that as-grown SnS and SnS2 films were polycrystalline; (1 1 1)/(0 0 1) peaks as the preferred orientation; 1.3 eV/2.8 eV as optical band gaps; and showed homogeneous microstructure with densely packed grains respectively. Ionization energy and electron affinity values were found by applying photoemission yield spectroscopy (PYS) to the CBD deposited SnS and SnS2 films for the first time. These values obtained as 5.3 eV and 4.0 eV for SnS films; 6.9 eV and 4.1 eV for SnS2 films. The band alignment of SnS/SnS2 junction showed TYPE-II heterostructure. The estimated conduction and valance band offsets were 0.1 eV and 1.6 eV respectively. The current density-voltage (J-V) measurements of the cell showed open circuit voltage (Voc) of 0.12 V, short circuit current density (Jsc) of 10.87 mA cm-2, fill factor (FF) of 39% and conversion efficiency of 0.51%.

  19. SNS Laser Stripping for H- Injection

    SciTech Connect

    V.V. Danilov, Y. Liu, K.B. Beard, V.G. Dudnikov, R.P. Johnson, Michelle D. Shinn

    2009-05-01

    The ORNL spallation neutron source (SNS) user facility requires a reliable, intense beams of protons. The technique of H- charge exchange injection into a storage ring or synchrotron has the potential to provide the needed beam currents, but it will be limited by intrinsic limitations of carbon and diamond stripping foils. A laser in combination with magnetic stripping has been used to demonstrate a new technique for high intensity proton injection, but several problems need to be solved before a practical system can be realized. Technology developed for use in Free Electron Lasers is being used to address the remaining challenges to practical implementation of laser controlled H- charge exchange injection for the SNS. These technical challenges include (1) operation in vacuum, (2) the control of the UV laser beam to synchronize with the H- beam and to shape the proton beam, (3) the control and stabilization of the Fabry-Perot resonator, and (4) protection of the mirrors from radiation.

  20. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.; Bratica, Robyn; Dempsey, Jack R.; Karle, Jessica

    2009-01-01

    This article presents summaries of recent crisis management publications. The first article summarized provides a review of research documenting that even when children are not physically proximal to a national disaster (9/11), they may still have negative reactions. The second article summarized is an examination of the PTSD diagnostic criterion…

  1. SECONDARY ELECTRON PRODUCTION AT THE SNS STORAGE RING COLLIMATOR.

    SciTech Connect

    ZHANG,S.Y.

    1999-03-29

    Secondary electron (SE) production is briefly reviewed. If the collimator of the SNS storage ring allows proton beam scraping to take place, the electron yield might be quite large. At the AGS Booster, by steering the Au{sup 31+} ion beam into the electrostatic inflector, beam scraping effect on SE production is studied. The results of this experiment can be translated into the situation of proton beam scraping at the SNS collimator. It seems sufficient to support a new look of the SNS ring collimator design.

  2. NEUTRONICS ANALYSES FOR SNS TARGETS DEPOSITIONS

    SciTech Connect

    Popova, Irina I; Remec, Igor; Gallmeier, Franz X

    2016-01-01

    In order to deposit Spallation Neutron Source (SNS) spent facility components replaced due to end-of-life radiation-induced material damage or burn-up, or because of mechanical failure or design improvements, waste classification analyses are being performed. These analyses include an accurate estimate of the radionuclide inventory, on which base components are classified and an appropriate container for transport and storage is determined. After the choice for the container is made, transport calculations are performed for the facility component to be placed inside the container, ensuring compliance with waste management regulations. When necessary, additional shielding is added. Most of the effort is concentrated on the target deposition, which normally takes place once or twice per year. Additionally, the second target station (STS) is in a process of design and waste management analyses for the STS target are being developed to support a deposition plan

  3. EXPERIENCE WITH THE SNS SC LINAC

    SciTech Connect

    Zhang, Yan; Aleksandrov, Alexander V; Allen, Christopher K; Campisi, Isidoro E; Cousineau, Sarah M; Danilov, Viatcheslav; Galambos, John D; Holmes, Jeffrey A; Jeon, Dong-O; Kim, Sang-Ho; Pelaia II, Tom; Plum, Michael A; Shishlo, Andrei P

    2008-01-01

    The SNS superconducting linac (SCL) is designed to deliver 1 GeV, up to 1.56-MW pulsed H- beams for neutron production. Commissioning of the accelerator systems was completed in June 2006, and the maximum beam energy achieved was approximately 952 MeV. In 2007, the SCL was successfully tuned for 1.01-GeV beam during a test operation. In the linac tune-up, phase scan signature matching, drifting beam measurement, and linac radio frequency cavity phase scaling were applied. In this paper, we will introduce the experiences with the SCL, including the tune-up, beam loss, and beam activation, and briefly discuss beam parameter measurements

  4. Comparison Analysis among Large Amount of SNS Sites

    NASA Astrophysics Data System (ADS)

    Toriumi, Fujio; Yamamoto, Hitoshi; Suwa, Hirohiko; Okada, Isamu; Izumi, Kiyoshi; Hashimoto, Yasuhiro

    In recent years, application of Social Networking Services (SNS) and Blogs are growing as new communication tools on the Internet. Several large-scale SNS sites are prospering; meanwhile, many sites with relatively small scale are offering services. Such small-scale SNSs realize small-group isolated type of communication while neither mixi nor MySpace can do that. However, the studies on SNS are almost about particular large-scale SNSs and cannot analyze whether their results apply for general features or for special characteristics on the SNSs. From the point of view of comparison analysis on SNS, comparison with just several types of those cannot reach a statistically significant level. We analyze many SNS sites with the aim of classifying them by using some approaches. Our paper classifies 50,000 sites for small-scale SNSs and gives their features from the points of network structure, patterns of communication, and growth rate of SNS. The result of analysis for network structure shows that many SNS sites have small-world attribute with short path lengths and high coefficients of their cluster. Distribution of degrees of the SNS sites is close to power law. This result indicates the small-scale SNS sites raise the percentage of users with many friends than mixi. According to the analysis of their coefficients of assortativity, those SNS sites have negative values of assortativity, and that means users with high degree tend to connect users with small degree. Next, we analyze the patterns of user communication. A friend network of SNS is explicit while users' communication behaviors are defined as an implicit network. What kind of relationships do these networks have? To address this question, we obtain some characteristics of users' communication structure and activation patterns of users on the SNS sites. By using new indexes, friend aggregation rate and friend coverage rate, we show that SNS sites with high value of friend coverage rate activate diary postings

  5. Synthesis, photocatalytic and antimicrobial properties of SnO2, SnS2 and SnO2/SnS2 nanostructure.

    PubMed

    Fakhri, Ali; Behrouz, Sajjad; Pourmand, Melika

    2015-08-01

    Nanoscale SnO2, SnS2 and SnO2/SnS2 were synthesized by hydrothermal treatment method and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH) and UV-vis spectra. The photocatalytic activity of SnO2, SnS2 and SnO2/SnS2 were tested with Enrofloxacin antibiotic. The tetragonal and hexagonal SnO2 and SnS2 phase was confirmed through XRD, respectively. The photocatalytic results indicated that the SnO2/SnS2 enhanced the photocatalytic activity and could be effectively used as photocatalyst for degradation of Enrofloxacin antibiotic pollutant. The results of antibacterial experiment under visible light irradiation demonstrate that the SnO2/SnS2 nanocomposite exhibit enhanced antibacterial efficiency compared with pure SnO2 and SnS2. The antifungal activity of the nanoscale SnO2, SnS2 and SnO2/SnS2 against Candida albicans was assessed using the disc-diffusion susceptibility tests. It was seen that the antifungal activity of SnO2/SnS2 nanocomposite is higher than the pure SnO2 and SnS2 toward pathogenic C. albicans.

  6. Brain anatomy alterations associated with Social Networking Site (SNS) addiction.

    PubMed

    He, Qinghua; Turel, Ofir; Bechara, Antoine

    2017-03-23

    This study relies on knowledge regarding the neuroplasticity of dual-system components that govern addiction and excessive behavior and suggests that alterations in the grey matter volumes, i.e., brain morphology, of specific regions of interest are associated with technology-related addictions. Using voxel based morphometry (VBM) applied to structural Magnetic Resonance Imaging (MRI) scans of twenty social network site (SNS) users with varying degrees of SNS addiction, we show that SNS addiction is associated with a presumably more efficient impulsive brain system, manifested through reduced grey matter volumes in the amygdala bilaterally (but not with structural differences in the Nucleus Accumbens). In this regard, SNS addiction is similar in terms of brain anatomy alterations to other (substance, gambling etc.) addictions. We also show that in contrast to other addictions in which the anterior-/ mid- cingulate cortex is impaired and fails to support the needed inhibition, which manifests through reduced grey matter volumes, this region is presumed to be healthy in our sample and its grey matter volume is positively correlated with one's level of SNS addiction. These findings portray an anatomical morphology model of SNS addiction and point to brain morphology similarities and differences between technology addictions and substance and gambling addictions.

  7. Brain anatomy alterations associated with Social Networking Site (SNS) addiction

    PubMed Central

    He, Qinghua; Turel, Ofir; Bechara, Antoine

    2017-01-01

    This study relies on knowledge regarding the neuroplasticity of dual-system components that govern addiction and excessive behavior and suggests that alterations in the grey matter volumes, i.e., brain morphology, of specific regions of interest are associated with technology-related addictions. Using voxel based morphometry (VBM) applied to structural Magnetic Resonance Imaging (MRI) scans of twenty social network site (SNS) users with varying degrees of SNS addiction, we show that SNS addiction is associated with a presumably more efficient impulsive brain system, manifested through reduced grey matter volumes in the amygdala bilaterally (but not with structural differences in the Nucleus Accumbens). In this regard, SNS addiction is similar in terms of brain anatomy alterations to other (substance, gambling etc.) addictions. We also show that in contrast to other addictions in which the anterior-/ mid- cingulate cortex is impaired and fails to support the needed inhibition, which manifests through reduced grey matter volumes, this region is presumed to be healthy in our sample and its grey matter volume is positively correlated with one’s level of SNS addiction. These findings portray an anatomical morphology model of SNS addiction and point to brain morphology similarities and differences between technology addictions and substance and gambling addictions. PMID:28332625

  8. The Inelastic Instrument suite at the SNS

    SciTech Connect

    Granroth, Garrett E; Abernathy, Douglas L; Ehlers, Georg; Hagen, Mark E; Herwig, Kenneth W; Mamontov, Eugene; Ohl, Michael E; Wildgruber, Christoph U

    2008-01-01

    Abstract The instruments in the extensive suite of spectrometers at the SNS are in various stages of installation and commissioning. The Back Scattering Spectrometer (BASIS) is installed and is in commissioning. It's near backscattering analyzer crystals provide the 3 eV resolution as expected. BASIS will enter the user program in the fall of 2007. The ARCS wide angular-range thermal to epithermal neutron spectrometer will come on line in the fall of 2007 followed shortly by the Cold Neutron Chopper Spectrometer. These two direct geometry instruments provide moderate resolution and the ability to trade resolution for flux. In addition both instruments have detector coverage out to 140o to provide a large Q range. The SEQUOIA spectrometer, complete in 2008, is the direct geometry instrument that will provide fine resolution in the thermal to epithermal range. The Spin-Echo spectrometer, to be completed on a similar time scale, will provide the finest energy resolution worldwide. The HYSPEC spectrometer, available no later than 2011, will provide polarized capabilities and optimized flux in the thermal energy range. Finally, the Vision chemical spectrometer will use crystal analyzers to study energy transfers into the epithermal range

  9. HIGH LEVEL RF FOR THE SNS RING.

    SciTech Connect

    ZALTSMAN,A.; BLASKIEWICZ,M.; BRENNAN,J.; BRODOWSKI,J.; METH,M.; SPITZ,R.; SEVERINO,F.

    2002-06-03

    A high level RF system (HLRF) consisting of power amplifiers (PA's) and ferrite loaded cavities is being designed and built by Brookhaven National Laboratory (BNL) for the Spallation Neutron Source (SNS) project. It is a fixed frequency, two harmonic system whose main function is to maintain a gap for the kicker rise time. Three cavities running at the fundamental harmonic (h=l) will provide 40 kV and one cavity at the second harmonic (h=2) will provide 20 kV. Each cavity has two gaps with a design voltage of 10 kV per gap and will be driven by a power amplifier (PA) directly adjacent to it. The PA uses a 600kW tetrode to provide the necessary drive current. The anode of the tetrode is magnetically coupled to the downstream cell of the cavity. Drive to the PA will be provided by a wide band, solid state amplifier located remotely. A dynamic tuning scheme will be implemented to help compensate for the effect of beam loading.

  10. RF Processing of the Couplers for the SNS Superconducting Cavities

    SciTech Connect

    Y.Kang; I.E. Campisi; D. Stout; A. Vassioutchenko; M. Stirbet; M. Drury; T. Powers

    2005-07-10

    All eighty-one fundamental power couplers for the 805 MHz superconducting cavities of the SNS linac have been RF conditioned and installed in the cryomodules successfully. The couplers were RF processed at JLAB or at the SNS in ORNL: more than forty couplers have been RF conditioned in the SNS RF Test Facility (RFTF) after the first forty couplers were conditioned at JLAB. The couplers were conditioned up to 650 kW forward power at 8% duty cycle in traveling and standing waves. They were installed on the cavities in the cryomodules and then assembled with the airside waveguide transitions. The couplers have been high power RF tested with satisfactory accelerating field gradients in the cooled cavities.

  11. Effect of indium and antimony doping in SnS single crystals

    SciTech Connect

    Chaki, Sunil H. Chaudhary, Mahesh D.; Deshpande, M.P.

    2015-03-15

    Highlights: • Single crystals growth of pure SnS, indium doped SnS and antimony doped SnS by direct vapour transport (DVT) technique. • Doping of In and Sb occurred in SnS single crystals by cation replacement. • The replacement mechanism ascertained by EDAX, XRD and substantiated by Raman spectra analysis. • Dopants concentration affects the optical energy bandgap. • Doping influences electrical transport properties. - Abstract: Single crystals of pure SnS, indium (In) doped SnS and antimony (Sb) doped SnS were grown by direct vapour transport (DVT) technique. Two doping concentrations of 5% and 15% each were employed for both In and Sb dopants. Thus in total five samples were studied viz., pure SnS (S1), 5% In doped SnS (S2), 15% In doped SnS (S3), 5% Sb doped SnS (S4) and 15% Sb doped SnS (S5). The grown single crystal samples were characterized by evaluating their surface microstructure, stoichiometric composition, crystal structure, Raman spectroscopy, optical and electrical transport properties using appropriate techniques. The d.c. electrical resistivity and thermoelectric power variations with temperature showed semiconducting and p-type nature of the as-grown single crystal samples. The room temperature Hall Effect measurements further substantiated the semiconducting and p-type nature of the as-grown single crystal samples. The obtained results are deliberated in detail.

  12. The 1st Baltic Osseointegration Academy and Lithuanian University of Health Sciences Consensus Conference 2016. Summary and Consensus Statements: Group II - Peri-Implantitis Diagnostics and Decision Tree

    PubMed Central

    Dursun, Erhan; Galindo-Moreno, Pablo; Juodzbalys, Gintaras; López-Martínez, Jesús; O'Valle, Francisco; Padial-Molina, Miguel; Ramanauskaite, Ausra

    2016-01-01

    ABSTRACT Introduction The task of Group 2 was to review and update the existing data concerning clinical and genetic methods of diagnostics of peri-implantitis. Special interest was paid to the peri-implant crevicular fluid (PICF) overview including analysis of enzymes and biomarkers and microbial profiles from implants. Material and Methods The main areas of interest were as follows: effect of smoking and history of periodontitis, prosthetic treatment mistakes, excess cement, overloading, general diseases influence on peri-implantitis development. The systematic review and/or meta-analysis were registered in PROSPERO, an international prospective register of systematic reviews: http://www.crd.york.ac.uk/PROSPERO/. The literature in the corresponding areas of interest was searched and reported using the PRISMA (Preferred Reporting Item for Systematic Review and Meta-Analysis) Statement: http://www.prisma-statement.org/. The method of preparation of systematic reviews of the literature based on comprehensive search strategies was discussed and standardized. The summary of the materials and methods employed by the authors in preparing the systematic review and/or meta-analysis is presented in Preface chapter. Results The results and conclusions of the review process are presented in the respective papers. The group′s general commentaries, consensus statements, clinical recommendations and implications for research are presented in this article. PMID:27833736

  13. Influence of reaction conditions for the fabrication of Cu2SnS3 and Cu3SnS4 in ethylene glycol

    NASA Astrophysics Data System (ADS)

    Gusain, Meenakshi; Rawat, Pooja; Nagarajan, Rajamani

    2015-05-01

    Cubic Cu2SnS3 and tetragonal Cu3SnS4 have been synthesized successfully using thiourea complexes of copper and tin in ethylene glycol by a simple change in the mode of mixing the reactants. While cubic Cu2SnS3 resulted from one-pot synthesis, mixing the colloids of copper and tin in ethylene glycol yielded tetragonal Cu3SnS4. The phases were characterized by high resolution powder x-ray diffraction (PXRD), UV-vis, Raman spectroscopy, SEM-EDX, HR-TEM and SAED measurements. Optical band gap of 0.92 eV (for Cu2SnS3) and 1.35 eV (for Cu3SnS4) were deduced from UV-vis spectroscopy data.

  14. How does personality matter? An investigation of the impact of extraversion on individuals' SNS use.

    PubMed

    Deng, Shengli; Liu, Yong; Li, Hongxiu; Hu, Feng

    2013-08-01

    The fast proliferation of social networking sites (SNS) offers Internet users new possibilities for developing and maintaining their social network. Despite a growing interest in SNS, less research attention has been paid to SNS usage from the perspective of personality, that is, the Big Five personality traits. This study develops a model to elucidate how extraversion, an important dimension of personality, affects the perceptions of SNS users and their continuance intention. The research model is empirically tested with answers gained from 221 usable questionnaires. The results indicate that extraversion positively affects perceived satisfaction, supplementary entertainment, and critical mass directly, and indirectly influences both playfulness and SNS continuance intention.

  15. DESIGN OF BEAM-EXTRACTION SEPTUM MAGNET FOR THE SNS.

    SciTech Connect

    TSOUPAS,N.; LEE,Y.Y.; RANK,J.; TUOZZOLO,J.

    2001-06-18

    The beam-extraction process from the SNS accumulator ring [1,2] requires a Lambertson septum magnet. In this paper we discuss the geometrical and magnetic field requirements of the magnet and present results obtained from two and three dimensional magnetic field calculations that shows the field quality in the regions of interest of the septum magnet.

  16. Opportunities for Neutrino Physics at the Spallation Neutron Source (SNS)

    SciTech Connect

    Efremenko, Yuri; Hix, William Raphael

    2009-01-01

    In this paper we discuss opportunities for a neutrino program at the Spallation Neutrons Source (SNS) being commissioning at ORNL. Possible investigations can include study of neutrino-nuclear cross sections in the energy rage important for supernova dynamics and neutrino nucleosynthesis, search for neutrino-nucleus coherent scattering, and various tests of the standard model of electro-weak interactions.

  17. Implications of the PSR instability for the SNS

    SciTech Connect

    Blaskiewicz, M.

    2000-06-30

    The Los Alamos Proton Storage Ring suffers from a violent, high frequency, transverse instability at high beam current. The Spallation Neutron Source will be similar to the PSR and one must insure that the PSR instability will not keep SNS from reaching its design goal. Efforts toward understanding the instability are described.

  18. Overview of Privacy in Social Networking Sites (SNS)

    NASA Astrophysics Data System (ADS)

    Powale, Pallavi I.; Bhutkar, Ganesh D.

    2013-07-01

    Social Networking Sites (SNS) have become an integral part of communication and life style of people in today's world. Because of the wide range of services offered by SNSs mostly for free of cost, these sites are attracting the attention of all possible Internet users. Most importantly, users from all age groups have become members of SNSs. Since many of the users are not aware of the data thefts associated with information sharing, they freely share their personal information with SNSs. Therefore, SNSs may be used for investigating users' character and social habits by familiar or even unknown persons and agencies. Such commercial and social scenario, has led to number of privacy and security threats. Though, all major issues in SNSs need to be addressed, by SNS providers, privacy of SNS users is the most crucial. And therefore, in this paper, we have focused our discussion on "privacy in SNSs". We have discussed different ways of Personally Identifiable Information (PII) leakages from SNSs, information revelation to third-party domains without user consent and privacy related threats associated with such information sharing. We expect that this comprehensive overview on privacy in SNSs will definitely help in raising user awareness about sharing data and managing their privacy with SNSs. It will also help SNS providers to rethink about their privacy policies.

  19. COMPUTATIONAL BEAM DYNAMICS STUDIES FOR IMPROVING THE RING INJECTION AND EXTRACTION SYSTEMS IN SNS

    SciTech Connect

    Holmes, Jeffrey A; Cousineau, Sarah M; Plum, Michael A; Wang, Jian-Guang

    2008-01-01

    The ring injection and extraction systems must function as designed in order for the Spallation Neutron Source (SNS) to achieve its specified performance. In commissioning and early operations we have encountered problems that have been traced to these systems. We experienced high beam losses in and around the injection dump, the rectification of which has necessitated ongoing study and development by a multidisciplinary team. Results already include a number of enhancements of existing features and the addition of new elements and diagnostics. The problem in the extraction region stems from tilted beam distributions observed in the ring-to-target beam transport line (RTBT) and on the target, thus complicating the control of the beam-on-target distribution. This indicates the inadvertent introduction of x-y beam coupling somewhere upstream of the RTBT. The present paper describes computational studies, using the ORBIT Code, addressed at the detailed understanding and solution of these problems.

  20. STATUS OF NEW 2.5 MEV TEST FACILITY AT SNS

    SciTech Connect

    Aleksandrov, Alexander V; Champion, Mark; Crofford, Mark T; Kang, Yoon W; Menshov, Alexander A; Roseberry, Jr., R Tom; Stockli, Martin P; Webster, Anthony W; Welton, Robert F; Zhukov, Alexander P

    2014-01-01

    A new 2.5MeV beam test facility is being built at SNS. It consists of a 65 keV H- ion source, a 2.5MeV RFQ, a beam line with various beam diagnostics and a 6 kW beam dump. The facility is capable of producing one-ms-long pulses at 60Hz repetition rate with up to 50mA peak current. The commissioning with reduced average beam power is planned for fall 2014 to verify operation of all systems. The full power operation is scheduled to begin in 2015. The status of the facility will be presented as well as a discussion of the future R&D program.

  1. ABCB1 as predominant resistance mechanism in cells with acquired SNS-032 resistance

    PubMed Central

    Rothweiler, Florian; Voges, Yvonne; Balónová, Barbora; Blight, Barry A.; Cinatl, Jindrich

    2016-01-01

    The CDK inhibitor SNS-032 had previously exerted promising anti-neuroblastoma activity via CDK7 and 9 inhibition. ABCB1 expression was identified as major determinant of SNS-032 resistance. Here, we investigated the role of ABCB1 in acquired SNS-032 resistance. In contrast to ABCB1-expressing UKF-NB-3 sub-lines resistant to other ABCB1 substrates, SNS-032-adapted UKF-NB-3 (UKF-NB-3rSNS- 032300nM) cells remained sensitive to the non-ABCB1 substrate cisplatin and were completely re-sensitized to cytotoxic ABCB1 substrates by ABCB1 inhibition. Moreover, UKF-NB-3rSNS-032300nM cells remained similarly sensitive to CDK7 and 9 inhibition as UKF-NB-3 cells. In contrast, SHEPrSNS-0322000nM, the SNS-032-resistant sub-line of the neuroblastoma cell line SHEP, displayed low level SNS-032 resistance also when ABCB1 was inhibited. This discrepancy may be explained by the higher SNS-032 concentrations that were used to establish SHEPrSNS-0322000nM cells, since SHEP cells intrinsically express ABCB1 and are less sensitive to SNS-032 (IC50 912 nM) than UKF-NB-3 cells (IC50 153 nM). In conclusion, we show that ABCB1 expression represents the primary (sometimes exclusive) resistance mechanism in neuroblastoma cells with acquired resistance to SNS-032. Thus, ABCB1 inhibitors may increase the SNS-032 efficacy in ABCB1-expressing cells and prolong or avoid resistance formation. PMID:27517323

  2. A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors

    NASA Astrophysics Data System (ADS)

    Fernandes, P. A.; Salomé, P. M. P.; da Cunha, A. F.

    2010-06-01

    Thin films of Cu2SnS3 and Cu3SnS4 were grown by sulfurization of dc magnetron sputtered Sn-Cu metallic precursors in a S2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu2SnS3 phase changes. For a temperature of 350 °C the films were composed of tetragonal (I-42m) Cu2SnS3. The films sulfurized at a maximum temperature of 400 °C presented a cubic (F-43m) Cu2SnS3 phase. On increasing the temperature up to 520 °C, the Sn content of the layer decreased and orthorhombic (Pmn21) Cu3SnS4 was formed. The phase identification and structural analysis were performed using x-ray diffraction (XRD) and electron backscattered diffraction (EBSD) analysis. Raman scattering analysis was also performed and a comparison with XRD and EBSD data allowed the assignment of peaks at 336 and 351 cm-1 for tetragonal Cu2SnS3, 303 and 355 cm-1 for cubic Cu2SnS3, and 318, 348 and 295 cm-1 for the Cu3SnS4 phase. Compositional analysis was done using energy dispersive spectroscopy and induced coupled plasma analysis. Scanning electron microscopy was used to study the morphology of the layers. Transmittance and reflectance measurements permitted the estimation of absorbance and band gap. These ternary compounds present a high absorbance value close to 104 cm-1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu2SnS3, 0.96 eV for cubic (F-43m) Cu2SnS3 and 1.60 eV for orthorhombic (Pmn21) Cu3SnS4. A hot point probe was used for the determination of semiconductor conductivity type. The results show that all the samples are p-type semiconductors. A four-point probe was used to obtain the resistivity of these samples. The resistivities for tetragonal Cu2SnS3, cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4 are 4.59 × 10-2 Ω cm, 1.26 × 10-2 Ω cm, 7.40 × 10-4 Ω cm, respectively.

  3. Interceptive Beam Diagnostics - Signal Creation and Materials Interactions

    SciTech Connect

    Plum, Michael

    2004-11-10

    The focus of this tutorial will be on interceptive beam diagnostics such as wire scanners, screens, and harps. We will start with an overview of the various ways beams interact with materials to create signals useful for beam diagnostics systems. We will then discuss the errors in a harp or wire scanner profile measurement caused by errors in wire position, number of samples, and signal errors. Finally we will apply our results to two design examples-the SNS wire scanner system and the SNS target harp.

  4. Motif of misfit layer compounds (SnS) xTS 2 (T=Ti, V, Nb, Ta) in the matrix of SnS 2

    NASA Astrophysics Data System (ADS)

    Abramov, S. P.

    1999-09-01

    The possibility of T (T=Ti, V, Nb, Ta) insertion in the layer matrix of SnS 2 (when T≪Sn) presents a special case of intercalation for the specific interactions that are inherent in the misfit layer compounds (SnS) xTS 2 ( x≈1). FT Raman spectra of T xSnS 2 (T=Ti, V) with x≪1 testify to the SnS 2 matrix that is invariable with respect to a charge transfer from T to SnS 2 layers as compared with the pristine SnS 2. At the same time the T xSnS 2 structure ( x≪1) taken as a whole has substantial features in the UV-IR spectra as compared with the pristine SnS 2 but is still a semiconductor at least in the case of T=Ti. This points out in the cluster manner of TS 2 insertion in the matrix of SnS 2 with the interactions that are typical of the misfit layer compounds (SnS) xTS 2 in which metallic conductivity occurs in the TS 2 layers.

  5. MODEL BENCHMARK WITH EXPERIMENT AT THE SNS LINAC

    SciTech Connect

    Shishlo, Andrei P; Aleksandrov, Alexander V; Liu, Yun; Plum, Michael A

    2016-01-01

    The history of attempts to perform a transverse match-ing in the Spallation Neutron Source (SNS) superconduct-ing linac (SCL) is discussed. The SCL has 9 laser wire (LW) stations to perform non-destructive measurements of the transverse beam profiles. Any matching starts with the measurement of the initial Twiss parameters, which in the SNS case was done by using the first four LW stations at the beginning of the superconducting linac. For years the consistency between data from all LW stations could not be achieved. This problem was resolved only after significant improvements in accuracy of the phase scans of the SCL cavities, more precise analysis of all available scan data, better optics planning, and the initial longitudi-nal Twiss parameter measurements. The presented paper discusses in detail these developed procedures.

  6. Shielding Design of the Spallation Neutron Source (SNS)

    SciTech Connect

    Johnson, J.O.

    1998-09-17

    The shielding design is important for the construction of an intense high-energy accelerator facility like the proposed Spallation Neutron Source (SNS) due to its impact on conventional facility design, maintenance operations, and since the cost for the radiation shielding shares a considerable part of the total facility costs. A calculational strategy utilizing coupled high energy Monte Carlo calculations and multi-dimensional discrete ordinates calculations, along with semi-empirical calculations, was implemented to perform the conceptual design shielding assessment of the proposed SNS. Biological shields have been designed and assessed for the proton beam transport system and associated beam dumps, the target station, and the target service cell and general remote maintenance cell. Shielding requirements have been assessed with respect to weight, space, and dose-rate constraints for operating, shutdown, and accident conditions. A discussion of the proposed facility design, conceptual design shielding requirements, calculational strategy, source terms, preliminary results and conclusions, and recommendations for additional analyses are presented.

  7. IGBT Gate Driver Upgrades to the HVCM at the SNS

    SciTech Connect

    Solley, Dennis J; Anderson, David E; Patel, Gunjan P; Peplov, Vladimir V; Saethre, Robert B; Wezensky, Mark W

    2012-01-01

    The SNS at ORNL has been fully operational since 2006 and in September 2009, the design goal of 1MW of sustained beam power on target was achieved. Historically, the high voltage converter modulators (HVCM) have been a known problem area and, in order to reach another SNS milestone of 90% availability, a new gate driver was one of several areas targeted to improve the overall reliability of the HVCM systems. The drive capability and fault protection of the large IGBT modules in the HVCM were specifically addressed to improve IGBT switching characteristics and provide enhanced troubleshooting and monitoring capabilities for the critical IGBT/driver pair. This paper outlines the work involved; the result obtained and documents the driver s long-term performance. Enhanced features, designed to be used in conjunction with a new controller presently under development, will also be discussed.

  8. LASER BEAM PROFILE MONITOR DEVELOPMENT AT BNL FOR SNS.

    SciTech Connect

    CONNOLLY,R.; CAMERON,P.; CUPOLO,J.; GASSNER,D.; GRAU,M.; KESSELMAN,M.; PENG,S.; SIKORA,R.

    2002-05-06

    A beam profile monitor for H-beams based on laser photoneutralization is being developed at Brookhaven National Laboratory (BNL) for use on the Spallation Neutron Source (SNS) [l]. An H ion has a first ionization potential of 0.75eV and can be neutralized by light from a Nd:YAG laser (h=1064nm). To measure beam profiles, a narrow laser beam is passed through the ion beam neutralizing a portion of the H-beam struck by the laser. The laser trajectory is stepped across the ion beam. At each laser position, the reduction of the beam current caused by the laser is measured. A proof-of-principle experiment was done earlier at 750keV. This paper reports on measurements made on 200MeV beam at BNL and with a compact scanner prototype at Lawrence Berkeley National Lab on beam from the SNS RFQ.

  9. TRACKING TESTS FOR THE SNS FAST INJECTION BUMP POWER SUPPLY

    SciTech Connect

    ENG,W.CUTLER,R.DEWAN,S.ET AL.

    2004-07-05

    The tracking requirement of the SNS Fast Injection Bump power supplies is described. In addition to the usual tracking between the load current and the input reference of a power supply, these power supplies must also track between pairs of units under slightly different loads. This paper describes the use of a current-null test to measure tracking performances. For the actual tests, a single dummy magnet load was used to measure the tracking between the first two production units at the manufacturer's facility. Using the Yokogawa WE7000 waveform. PC-based measurement instrument, input and output waveforms are digitized and stored in data files. A program written for this application is then used to extract data from these files to construct, analyze the waveforms and characterize the power supply performance. Results of the measurements of two SNS Fast Injection Bump power supplies will be presented in this paper.

  10. Method Producing an SNS Superconducting Junction with Weak Link Barrier

    NASA Technical Reports Server (NTRS)

    Hunt, Brian D. (Inventor)

    1999-01-01

    A method of producing a high temperature superconductor Josephson element and an improved SNS weak link barrier element is provided. A YBaCuO superconducting electrode film is deposited on a substrate at a temperature of approximately 800 C. A weak link barrier layer of a nonsuperconducting film of N-YBaCuO is deposited over the electrode at a temperature range of 520 C. to 540 C. at a lower deposition rate. Subsequently a superconducting counter-electrode film layer of YBaCuO is deposited over the weak link barrier layer at approximately 800 C. The weak link barrier layer has a thickness of approximately 50 A and the SNS element can be constructed to provide an edge geometry junction.

  11. SnS2 Thin Film Deposition by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Jaber, Abdallah Yahia; Alamri, Saleh Noaiman; Aida, Mohammed Salah

    2012-06-01

    Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

  12. SNS LINAC Wire Scanner System : Signal Levels and Accuracy.

    SciTech Connect

    Plum, M. A.; Christensen, W.; Myer, R. E.; Rose, C. R.

    2002-01-01

    The linac wire scanner system for the Spallation Neutron Source (SNS) at Oak Ridge, TN, USA, calls for 5 units in the medium energy beam transport (MEBT), 5 in the drift tube linac (DTL), and 10 in the coupled cavity linac (CCL). In this paper we present expected signal levels and an analysis of the error in the beam size measurement as functions of wire position and electrical signal errors.

  13. EPICS V4 Evaluation for SNS Neutron Data

    SciTech Connect

    Kasemir, Kay; Pearson, Matthew R; Guyotte, Greg S

    2015-01-01

    Version 4 of the Experimental Physics and Industrial Control System (EPICS) toolkit allows defining application-specific structured data types (pvData) and offers a network protocol for their efficient exchange (pvAccess). We evaluated V4 for the transport of neutron events from the detectors of the Spallation Neutron Source (SNS) to data acquisition and experiment monitoring systems. This includes the comparison of possible data structures, performance tests, and experience using V4 in production on a beam line.

  14. Microphonics and Lorentz Transfer Function Measurements on the SNS Cryomodules

    SciTech Connect

    Jean Delayen; G. Davis

    2003-09-01

    As part of the acceptance tests, we have performed a number of measurements of microphonics levels and frequency spectra on the SNS cryomodules. These measurements are particularly important since those cryomodules may be used in the high-energy section of the RIA driver, a low-current CW accelerator. Measurements of the complete transfer functions between rf field modulation and cavity resonant frequency have also been performed.

  15. Electron-cloud simulation results for the PSR and SNS

    SciTech Connect

    Pivi, M.; Furman, M.A.

    2002-07-08

    We present recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source (SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR) at Los Alamos. In particular, a complete refined model for the secondary emission process including the so called true secondary, rediffused and backscattered electrons has been included in the simulation code.

  16. HIGH INTENSITY EFFECTS IN THE SNS ACCUMULATOR RING

    SciTech Connect

    Holmes, Jeffrey A; Cousineau, Sarah M; Danilov, Viatcheslav; Plum, Michael A; Shishlo, Andrei P

    2008-01-01

    Currently operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, RF bunching, and beam scattering, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. At each stage of the power ramp-up, we use all available resources to understand and to minimize beam losses. From the standpoint of beam dynamics, the losses observed so far under normal operating conditions have not involved collective phenomena. We are now entering the intensity regime in which this may change. In dedicated high intensity beam studies, we have already observed resistive wall, extraction kicker impedance-driven, and electron cloud activities. The analysis and simulation of this data are important ongoing activities at SNS. This paper discusses the status of this work, as well as other considerations necessary to the successful full power operation of SNS.

  17. The First ASME Code Stamped Cryomodule at SNS

    SciTech Connect

    Howell, M P; Crofford, M T; Douglas, D L; Kim, S -H; Steward, S T; Strong, W H; Afanador, R; Hannah, B S; Saunders, J; Mammosser, J D

    2012-07-01

    The first spare cryomodule for the Spallation Neutron Source (SNS) has been designed, fabricated, and tested by SNS personnel. The approach to design for this cryomodule was to hold critical design features identical to the original design such as bayonet positions, coupler positions, cold mass assembly, and overall footprint. However, this is the first SNS cryomodule that meets the pressure requirements put forth in the 10 CFR 851: Worker Safety and Health Program. The most significant difference is that Section VIII of the ASME Boiler and Pressure Vessel Code was applied to the vacuum vessel of this cryomodule. Applying the pressure code to the helium vessels within the cryomodule was considered. However, it was determined to be schedule prohibitive because it required a code case for materials that are not currently covered by the code. Good engineering practice was applied to the internal components to verify the quality and integrity of the entire cryomodule. The design of the cryomodule, fabrication effort, and cryogenic test results will be reported in this paper.

  18. WATER PURITY DEVELOPMENT FOR THE COUPLED CAVITY LINAC (CCL) AND DRIFT TUBE LINAC (DTL) STRUCTURES OF THE SPALLATION NEUTRON SOURCE (SNS) LINAC

    SciTech Connect

    D. KATONAK; J. BERNARDIN; S. HOPKINS

    2001-06-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the proton beam. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems. One of the primary components in the DTL and CCL water cooling systems, is a water purification system that is responsible for minimizing erosion, corrosion, scaling, biological growth, and hardware activation. The water purification system consists of filters, ion exchange resins, carbon beds, an oxygen scavenger, a UV source, and diagnostic instrumentation. This paper reviews related issues associated with water purification and describes the mechanical design of the SNS Linac water purification system.

  19. Synthesis and Size Dependent Reflectance Study of Water Soluble SnS Nanoparticles

    PubMed Central

    Xu, Ying; Al-Salim, Najeh; Tilley, Richard D.

    2012-01-01

    Near-monodispersed water soluble SnS nanoparticles in the diameter range of 3–6 nm are synthesized by a facile, solution based one-step approach using ethanolamine ligands. The optimal amount of triethanolamine is investigated. The effect of further heat treatment on the size of these SnS nanoparticles is discussed. Diffuse reflectance study of SnS nanoparticles agrees with predictions from quantum confinement model.

  20. Numerical modeling of the SNS H- ion source

    NASA Astrophysics Data System (ADS)

    Veitzer, Seth A.; Beckwith, Kristian R. C.; Kundrapu, Madhusudhan; Stoltz, Peter H.

    2015-04-01

    Ion source rf antennas that produce H- ions can fail when plasma heating causes ablation of the insulating coating due to small structural defects such as cracks. Reducing antenna failures that reduce the operating capabilities of the Spallation Neutron Source (SNS) accelerator is one of the top priorities of the SNS H- Source Program at ORNL. Numerical modeling of ion sources can provide techniques for optimizing design in order to reduce antenna failures. There are a number of difficulties in developing accurate models of rf inductive plasmas. First, a large range of spatial and temporal scales must be resolved in order to accurately capture the physics of plasma motion, including the Debye length, rf frequencies on the order of tens of MHz, simulation time scales of many hundreds of rf periods, large device sizes on tens of cm, and ion motions that are thousands of times slower than electrons. This results in large simulation domains with many computational cells for solving plasma and electromagnetic equations, short time steps, and long-duration simulations. In order to reduce the computational requirements, one can develop implicit models for both fields and particle motions (e.g. divergence-preserving ADI methods), various electrostatic models, or magnetohydrodynamic models. We have performed simulations using all three of these methods and have found that fluid models have the greatest potential for giving accurate solutions while still being fast enough to perform long timescale simulations in a reasonable amount of time. We have implemented a number of fluid models with electromagnetics using the simulation tool USim and applied them to modeling the SNS H- ion source. We found that a reduced, single-fluid MHD model with an imposed magnetic field due to the rf antenna current and the confining multi-cusp field generated increased bulk plasma velocities of > 200 m/s in the region of the antenna where ablation is often observed in the SNS source. We report

  1. INCREASED UNDERSTANDING OF BEAM LOSSES FROM THE SNS LINAC PROTON EXPERIMENT

    SciTech Connect

    Aleksandrov, Alexander V; Shishlo, Andrei P; Plum, Michael A; Lebedev, Valerie; Laface, Emanuele; Galambos, John D

    2013-01-01

    Beam loss is a major concern for high power hadron accelerators such as the Spallation Neutron Source (SNS). An unexpected beam loss in the SNS superconducting linac (SCL) was observed during the power ramp up and early operation. Intra-beam-stripping (IBS) loss, in which interactions between H- particles within the accelerated bunch strip the outermost electron, was recently identified as a possible cause of the beam loss. A set of experiments using proton beam acceleration in the SNS linac was conducted, which supports IBS as the primary beam loss mechanism in the SNS SCL.

  2. PLANS FOR A NEUTRON EDM EXPERIMENT AT SNS

    SciTech Connect

    ITO, TAKEYASU

    2007-01-31

    The electric dipole moment of the neutron, leptons, and atoms provide a unique window to Physics Beyond the Standard Model. They are currently developing a new neutron EDM experiment (the nEDM Experiment). This experiment, which will be run at the 8.9 {angstrom} Neutron Line at the Fundamental Neutron Physics Beamline (FNPB) at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory, will search for the neutron EDM with a sensitivity two orders of magnitude higher than the present limit. In this paper, the motivation for the experiment, the experimental method, and the present status of the experiment are discussed.

  3. PERFORMANCE OF AND UPGRADES TO THE SNS COLLIMATOR SYSTEMS

    SciTech Connect

    Plum, Michael A; Abdou, Ashraf A; Jacobs, Lorelei L; Janney, Jim G; Geoghegan, Patrick J; McTeer, Stephen Mark; Popova, Irina; Ferguson, Phillip D; Zhukov, Alexander P

    2009-01-01

    As the Spallation Neutron Source (SNS) beam power is increased, the collimator systems are becoming correspondingly more important. The High Energy Beam Transport (HEBT) transverse collimators are now routinely used during neutron production. We are in the process of redesigning the HEBT momentum collimation system due to problems with gas production from radiolysis. The Ring collimators are designed for two-stage operation but to date they are mainly used in one-stage mode. In this paper we will discuss the status, the operational performance, and upgrades to the collimation systems.

  4. Status of the SNS Ring Power Ramp UP

    SciTech Connect

    Plum, Michael A; Aleksandrov, Alexander V; Allen, Christopher K; Cousineau, Sarah M; Danilov, Viatcheslav; Galambos, John D; Holmes, Jeffrey A; Jeon, Dong-O; Pelaia II, Tom; Shishlo, Andrei P; Zhang, Yan

    2008-01-01

    Beam was first circulated in the Spallation Neutron Source (SNS) ring in January 2006. Since that time we have been working to raise the beam power to the design value of 1.4 MW. In general the power ramp up has been proceeding very well, but several issues have been uncovered. Examples include poor transmission of the waste beams in the injection dump beam line, and cross-plane coupling in the ring to target beam transport line. In this paper we will discuss these issues and present an overall status of the ring and the transport beam lines.

  5. Synthesis and Raman analysis of SnS nanoparticles synthesized by PVP assisted polyol method

    SciTech Connect

    Baby, Benjamin Hudson; Mohan, D. Bharathi

    2015-06-24

    SnS film was prepared by a simple drop casting method after synthesizing SnS nanoparticles by using PVP assisted polyol method. Confocal Raman study was carried out for the as deposited and annealed (150, 300 and 400 °C) films at two different excitation wavelengths 514 and 785 nm. At the excitation wavelength of 514 nm, the Raman modes showed for a mixed phase of SnS and SnS{sub 2} up to 150 °C and then only a pure SnS phase was observed up to 400 °C due to the dissociation of SnS{sub 2} in to SnS by releasing S. The increase in intensity of Raman (A{sub g} and B{sub 3g}) as well as IR (B{sub 3u}) active modes of SnS are observed with increasing annealing temperature at excitation wavelength 785 nm due to the increased crystallinity and inactiveness of SnS{sub 2} modes. X-ray diffraction confirming the formation of a single phase of SnS while the greater homogeneity in both size and shape of SnS nanoparticles were confirmed through surface morphology from SEM.

  6. The synthesis of multi-structured SnS nanocrystals toward enhanced performance for photovoltaic devices.

    PubMed

    Guo, Xin; Xie, Hao-Jun; Zheng, Jia-Wei; Xu, Hao; Wang, Qian-Kun; Li, Yan-Qing; Lee, Shuit-Tong; Tang, Jian-Xin

    2015-01-21

    The synthesis of multi-scale SnS nanostructures with favorable fluorescence is facilely accomplished via a well-excogitated gentle process, involving simple precursors, stabilized chemical medium and primitive ligand exchange. The fabricated SnS nanocrystals can be adopted as hole transporting materials in photovoltaic devices for enhancing its power conversion efficiency.

  7. RADIATION-RESISTANT FIBER OPTIC STRAIN SENSORS FOR SNS TARGET INSTRUMENTATION

    SciTech Connect

    Blokland, Willem; Bryan, Jeff; Riemer, Bernie; Sangrey, Robert L; Wendel, Mark W; Liu, Yun

    2016-01-01

    Measurement of stresses and strains in the mercury tar-get vessel of the Spallation Neutron Source (SNS) is important to understand the structural dynamics of the target. This work reports the development of radiation-resistant fiber optic strain sensors for the SNS target in-strumentation.

  8. Annealing effect for SnS thin films prepared by high-vacuum evaporation

    SciTech Connect

    Revathi, Naidu Bereznev, Sergei; Loorits, Mihkel; Raudoja, Jaan; Lehner, Julia; Gurevits, Jelena; Traksmaa, Rainer; Mikli, Valdek; Mellikov, Enn; Volobujeva, Olga

    2014-11-01

    Thin films of SnS are deposited onto molybdenum-coated soda lime glass substrates using the high-vacuum evaporation technique at a substrate temperature of 300 °C. The as-deposited SnS layers are then annealed in three different media: (1) H{sub 2}S, (2) argon, and (3) vacuum, for different periods and temperatures to study the changes in the microstructural properties of the layers and to prepare single-phase SnS photoabsorber films. It is found that annealing the layers in H{sub 2}S at 400 °C changes the stoichiometry of the as-deposited SnS films and leads to the formation of a dominant SnS{sub 2} phase. Annealing in an argon atmosphere for 1 h, however, causes no deviations in the composition of the SnS films, though the surface morphology of the annealed SnS layers changes significantly as a result of a 2 h annealing process. The crystalline structure, surface morphology, and photosensitivity of the as-deposited SnS films improves significantly as the result of annealing in vacuum, and the vacuum-annealed films are found to exhibit promising properties for fabricating complete solar cells based on these single-phase SnS photoabsorber layers.

  9. Perceptions of Teachers and Students towards Educational Application of SNS and Its Educational Effects in Middle School Class

    ERIC Educational Resources Information Center

    Lee, June; Lee, Yunoug; Kim, Mi Hwa

    2015-01-01

    SNS use by youth is a growing trend. However, there is a lack of studies on how the application of SNS can contribute to learning and public education for youth. As SNS was not originally developed for educational purposes, there is a possibility that it can be used for meaningful educational activity or that its application can lead to the…

  10. Radiation transport analyses in support of the SNS Target Station Neutron Beam Line Shutters Title I Design

    SciTech Connect

    Miller, T.M.; Pevey, R.E.; Lillie, R.A.; Johnson, J.O.

    2000-12-01

    A detailed radiation transport analysis of the Spallation Neutron Source (SNS) shutters is important for the construction of the SNS because of its impact on conventional facility design, normal operation of the facility, and maintenance operations. Thus far the analysis of the SNS shutter travel gaps has been completed. This analysis was performed using coupled Monte Carlo and multi-dimensional discrete ordinates calculations.

  11. Pd and Au Contacts to SnS: Thermodynamic Predictions and Annealing Study

    NASA Astrophysics Data System (ADS)

    Gurunathan, Ramya L.; Nasr, Joseph; Cordell, Jacob J.; Banai, Rona A.; Abraham, Michael; Cooley, Kayla A.; Horn, Mark; Mohney, Suzanne E.

    2016-12-01

    Tin(II) sulfide (SnS) is emerging as an attractive p-type absorber layer material for thin film photovoltaics, which motivates the search for Ohmic, low-resistance contacts for SnS. In this study, Pd and Au contacts were prepared on sputter-deposited SnS films and electrically characterized both as-deposited and after annealing of the contacts. Ternary phase diagrams were also calculated to help predict whether the chosen metals would react with the SnS film. Pd was expected to react with the SnS film, while Au was expected to be in thermodynamic equilibrium. The Pd contacts appeared reactive, and their resistance was minimized with post-deposition annealing at 400°C, while the Au contacts showed little change upon annealing and remained unreactive.

  12. Developing a Research Agenda to Optimize Diagnostic Imaging in the Emergency Department: An Executive Summary of the 2015 Academic Emergency Medicine Consensus Conference.

    PubMed

    Marin, Jennifer R; Mills, Angela M

    2015-12-01

    The 2015 Academic Emergency Medicine consensus conference, "Diagnostic Imaging in the Emergency Department: A Research Agenda to Optimize Utilization" was held on May 12, 2015, with the goal of developing a high-priority research agenda on which to base future research. The specific aims of the conference were to (1) understand the current state of evidence regarding emergency department (ED) diagnostic imaging use and identify key opportunities, limitations, and gaps in knowledge; (2) develop a consensus-driven research agenda emphasizing priorities and opportunities for research in ED diagnostic imaging; and (3) explore specific funding mechanisms available to facilitate research in ED diagnostic imaging. Over a 2-year period, the executive committee and other experts in the field convened regularly to identify specific areas in need of future research. Six content areas within emergency diagnostic imaging were identified before the conference and served as the breakout groups on which consensus was achieved: clinical decision rules; use of administrative data; patient-centered outcomes research; training, education, and competency; knowledge translation and barriers to imaging optimization; and comparative effectiveness research in alternatives to traditional computed tomography use. The executive committee invited key stakeholders to assist with the planning and to participate in the consensus conference to generate a multidisciplinary agenda. There were a total of 164 individuals involved in the conference and spanned various specialties, including general emergency medicine, pediatric emergency medicine, radiology, surgery, medical physics, and the decision sciences.

  13. Photoresponsive field-effect transistors based on multilayer SnS2 nanosheets

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Huang, Le; Wei, Zhongming

    2017-03-01

    2D SnS{}2 nanosheets are exfoliated by micromechanical exfoliation technique from SnS{}2 single crystals which are synthesized by CVT methods. Monolayer SnS{}2 nanosheet has been obtained and the Raman spectrum shows that A{}1{{g}} mode of monolayer SnS{}2 shows a slight softening compared with bulk SnS{}2 single crystal. The field effect transistors (FETs) based on multilayer SnS{}2 nanosheets have been fabricated, of which the electrical and photoelectrical properties have been measured. Under dark condition, with {V}{{sd}} of 1 V, our SnS{}2 FET shows n-type behavior. The carrier mobility of the FETs reach 3.51 {{{cm}}}2{{{V}}}-1{{{s}}}-1 and the ‘ON/OFF’ ratio is about 5× {10}2. The SnS{}2 FET is also illuminated under 532 nm laser with the power of 500 mW/cm{}2. The light absorption causes an increment of carrier mobility (from 3.51 {{{cm}}}2{{{V}}}-1{{{s}}}-1 under dark condition to 3.85 {{{cm}}}2{{{V}}}-1{{{s}}}-1 under 532 nm laser illumination with the power of 500 mW/cm{}2) of SnS{}2. The responsivity (R) and detectivity of our multilayer device under 500 mW/cm{}2 532 nm is 2.08 A/W and 6× {10}6 J, respectively. All the above properties indicate the potential of SnS{}2 nanosheets to be used as FETs and phototransistors.

  14. Developing a Research Agenda to Optimize Diagnostic Imaging in the Emergency Department: An Executive Summary of the 2015 Academic Emergency Medicine Consensus Conference.

    PubMed

    Marin, Jennifer R; Mills, Angela M

    2015-12-01

    The 2015 Academic Emergency Medicine (AEM) consensus conference, "Diagnostic Imaging in the Emergency Department: A Research Agenda to Optimize Utilization," was held on May 12, 2015, with the goal of developing a high-priority research agenda on which to base future research. The specific aims of the conference were to: 1) understand the current state of evidence regarding emergency department (ED) diagnostic imaging utilization and identify key opportunities, limitations, and gaps in knowledge; 2) develop a consensus-driven research agenda emphasizing priorities and opportunities for research in ED diagnostic imaging; and 3) explore specific funding mechanisms available to facilitate research in ED diagnostic imaging. Over a 2-year period, the executive committee and other experts in the field convened regularly to identify specific areas in need of future research. Six content areas within emergency diagnostic imaging were identified prior to the conference and served as the breakout groups on which consensus was achieved: clinical decision rules; use of administrative data; patient-centered outcomes research; training, education, and competency; knowledge translation and barriers to imaging optimization; and comparative effectiveness research in alternatives to traditional computed tomography use. The executive committee invited key stakeholders to assist with planning and to participate in the consensus conference to generate a multidisciplinary agenda. There were 164 individuals involved in the conference spanning various specialties, including emergency medicine (EM), radiology, surgery, medical physics, and the decision sciences. This issue of AEM is dedicated to the proceedings of the 16th annual AEM consensus conference as well as original research related to emergency diagnostic imaging.

  15. Next Generation H- Ion Sources for the SNS

    NASA Astrophysics Data System (ADS)

    Welton, R. F.; Stockli, M. P.; Murray, S. N.; Crisp, D.; Carmichael, J.; Goulding, R. H.; Han, B.; Tarvainen, O.; Pennisi, T.; Santana, M.

    2009-03-01

    The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H- ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H- ion source based on an A1N ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to ˜100 mA (60 Hz, 1 ms) have been observed and sustained currents >60 mA (60 Hz, 1 ms) have been demonstrated on the test stand. Accelerated beam currents of ˜40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H- beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

  16. Next Generation H{sup -} Ion Sources for the SNS

    SciTech Connect

    Welton, R. F.; Stockli, M. P.; Murray, S. N.; Crisp, D.; Carmichael, J.; Goulding, R. H.; Han, B.; Pennisi, T.; Santana, M.; Tarvainen, O.

    2009-03-12

    The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H- ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H- ion source based on an A1N ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to {approx}100 mA(60 Hz, 1 ms) have been observed and sustained currents >60 mA(60 Hz, 1 ms) have been demonstrated on the test stand. Accelerated beam currents of {approx}40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H- beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

  17. Spallation Neutron Source SNS Diamond Stripper Foil Development

    SciTech Connect

    Shaw, Robert W; Plum, Michael A; Wilson, Leslie L; Feigerle, Charles S.; Borden, Michael J.; Irie, Y.; Sugai, I; Takagi, A

    2007-01-01

    Diamond stripping foils are under development for the SNS. Freestanding, flat 300 to 500 {micro}g/cm{sup 2} foils as large as 17 x 25 mm{sup 2} have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 15 {micro}C of protons, approximately 64% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 C of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (640 keV H{sup -}) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.

  18. Tin Compensation for the SnS Based Optoelectronic Devices

    NASA Astrophysics Data System (ADS)

    Wang, S. F.; Wang, W.; Fong, W. K.; Yu, Y.; Surya, C.

    2017-01-01

    In this paper we report the growth of high quality SnS thin films with good crystallinity deposited on two-dimensional (2D) mica substrates. It is believed that the 2D nature of SnS, with strong intra-layer covalent bonds and weak inter-layer van der Waals interactions, is responsible for its relative insensitivity to lattice mismatch. We also investigated the reduction of Sn vacancies in the material using Sn-compensation technique during the material growth process. The experimental results clearly demonstrated substantial enhancements in the electrical and structural properties for films deposited using Sn-compensation technique. A mobility of 51 cm2  V‑1 s‑1 and an XRD rocking curve full width at half maximum of 0.07° were obtained. Sn-compensated SnS/GaN:Si heterojunctions were fabricated and significant improvement in both the I-V characteristics and the spectral responsivities of the devices were characterized.

  19. Tin Compensation for the SnS Based Optoelectronic Devices

    PubMed Central

    Wang, S. F.; Wang, W.; Fong, W. K.; Yu, Y.; Surya, C.

    2017-01-01

    In this paper we report the growth of high quality SnS thin films with good crystallinity deposited on two-dimensional (2D) mica substrates. It is believed that the 2D nature of SnS, with strong intra-layer covalent bonds and weak inter-layer van der Waals interactions, is responsible for its relative insensitivity to lattice mismatch. We also investigated the reduction of Sn vacancies in the material using Sn-compensation technique during the material growth process. The experimental results clearly demonstrated substantial enhancements in the electrical and structural properties for films deposited using Sn-compensation technique. A mobility of 51 cm2  V−1 s−1 and an XRD rocking curve full width at half maximum of 0.07° were obtained. Sn-compensated SnS/GaN:Si heterojunctions were fabricated and significant improvement in both the I-V characteristics and the spectral responsivities of the devices were characterized. PMID:28045033

  20. High Power RF Test Facility at the SNS

    SciTech Connect

    Y.W. Kang; D.E. Anderson; I.E. Campisi; M. Champion; M.T. Crofford; R.E. Fuja; P.A. Gurd; S. Hasan; K.-U. Kasemir; M.P. McCarthy; D. Stout; J.Y. Tang; A.V. Vassioutchenko; M. Wezensky; G.K. Davis; M. A. Drury; T. Powers; M. Stirbet

    2005-05-16

    RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavities have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducting and superconducting accelerating cavities and components.

  1. Next Generation H- Ion Sources for the SNS

    SciTech Connect

    Welton, Robert F; Carmichael, Justin R; Carr, Jr, Jerry; Crisp, Danny W; Goulding, Richard Howell; Han, Baoxi; Pennisi, Terry R; Murray Jr, S N; Stockli, Martin P; Tarvainen, Olli A; Santana, Manuel

    2009-01-01

    The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H{sup -} ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H{sup -} ion source based on an AlN ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to {approx}100 mA (60Hz, 1ms) have been observed and sustained currents >60 mA (60Hz, 1ms) have been demonstrated on the test stand. Accelerated beam currents of {approx}40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H{sup -} beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

  2. SNS Sample Activation Calculator Flux Recommendations and Validation

    SciTech Connect

    McClanahan, Tucker C.; Gallmeier, Franz X.; Iverson, Erik B.; Lu, Wei

    2015-02-01

    The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) uses the Sample Activation Calculator (SAC) to calculate the activation of a sample after the sample has been exposed to the neutron beam in one of the SNS beamlines. The SAC webpage takes user inputs (choice of beamline, the mass, composition and area of the sample, irradiation time, decay time, etc.) and calculates the activation for the sample. In recent years, the SAC has been incorporated into the user proposal and sample handling process, and instrument teams and users have noticed discrepancies in the predicted activation of their samples. The Neutronics Analysis Team validated SAC by performing measurements on select beamlines and confirmed the discrepancies seen by the instrument teams and users. The conclusions were that the discrepancies were a result of a combination of faulty neutron flux spectra for the instruments, improper inputs supplied by SAC (1.12), and a mishandling of cross section data in the Sample Activation Program for Easy Use (SAPEU) (1.1.2). This report focuses on the conclusion that the SAPEU (1.1.2) beamline neutron flux spectra have errors and are a significant contributor to the activation discrepancies. The results of the analysis of the SAPEU (1.1.2) flux spectra for all beamlines will be discussed in detail. The recommendations for the implementation of improved neutron flux spectra in SAPEU (1.1.3) are also discussed.

  3. Graphene contacts to a HfSe2/SnS2 heterostructure.

    PubMed

    Su, Shanshan; Das, Protik; Ge, Supeng; Lake, Roger K

    2017-02-14

    Two-dimensional (2D) heterostructures and all-2D contacts are of high interest for electronic device applications, and the SnS2/HfSe2 bilayer heterostructure with graphene contacts has some unique, advantageous properties. The SnS2/HfSe2 heterostructure is interesting because of the strong intermixing of the two conduction bands and the large work function of the SnS2. The band lineup of the well separated materials indicates a type II heterostructure, but the conduction band minimum of the SnS2/HfSe2 bilayer is a coherent superposition of the orbitals from the two layers with a spectral weight of 60% on the SnS2 and 40% on the HfSe2 for AA stacking. These relative weights can be either increased or reversed by an applied vertical field. A 3×3 supercell of graphene and a 2×2 supercell of SnS2/HfSe2 have a lattice mismatch of 0.1% and both the SnS2/HfSe2 conduction band at M and the graphene Dirac point at K are zone-folded to Γ. Placing graphene on the SnS2/HfSe2 bilayer results in large n-type charge transfer doping of the SnS2/HfSe2 bilayer, on the order of 10(13)/cm(2), and the charge transfer is accompanied by a negative Schottky barrier contact for electron injection from the graphene into the SnS2/HfSe2 bilayer conduction band. Binding energies and the anti-crossing gaps of the graphene and the SnS2/HfSe2 electronic bands both show that the coupling of graphene to the HfSe2 layer is significantly larger than its coupling to the SnS2 layer. A tunneling Hamiltonian estimate of the contact resistance of the graphene to the SnS2/HfSe2 heterostructure predicts an excellent low-resistance contact.

  4. Graphene contacts to a HfSe2/SnS2 heterostructure

    NASA Astrophysics Data System (ADS)

    Su, Shanshan; Das, Protik; Ge, Supeng; Lake, Roger K.

    2017-02-01

    Two-dimensional (2D) heterostructures and all-2D contacts are of high interest for electronic device applications, and the SnS2/HfSe2 bilayer heterostructure with graphene contacts has some unique, advantageous properties. The SnS2/HfSe2 heterostructure is interesting because of the strong intermixing of the two conduction bands and the large work function of the SnS2. The band lineup of the well separated materials indicates a type II heterostructure, but the conduction band minimum of the SnS2/HfSe2 bilayer is a coherent superposition of the orbitals from the two layers with a spectral weight of 60% on the SnS2 and 40% on the HfSe2 for AA stacking. These relative weights can be either increased or reversed by an applied vertical field. A 3 ×3 supercell of graphene and a 2 ×2 supercell of SnS2/HfSe2 have a lattice mismatch of 0.1% and both the SnS2/HfSe2 conduction band at M and the graphene Dirac point at K are zone-folded to Γ . Placing graphene on the SnS2/HfSe2 bilayer results in large n-type charge transfer doping of the SnS2/HfSe2 bilayer, on the order of 1013/cm2, and the charge transfer is accompanied by a negative Schottky barrier contact for electron injection from the graphene into the SnS2/HfSe2 bilayer conduction band. Binding energies and the anti-crossing gaps of the graphene and the SnS2/HfSe2 electronic bands both show that the coupling of graphene to the HfSe2 layer is significantly larger than its coupling to the SnS2 layer. A tunneling Hamiltonian estimate of the contact resistance of the graphene to the SnS2/HfSe2 heterostructure predicts an excellent low-resistance contact.

  5. Development of SnS2/RGO nanosheet composite for cost-effective aqueous hybrid supercapacitors

    NASA Astrophysics Data System (ADS)

    Chauhan, Himani; Singh, Manoj K.; Kumar, Praveen; Hashmi, Safir Ahmad; Deka, Sasanka

    2017-01-01

    The development of low cost supercapacitor cells with unique capacitive properties is essential for many domestic and industrial purposes. Here we report the first ever application of SnS2-reduced graphene oxide (SnS2/RGO) layered nanocomposite as a superior electrode material for symmetric aqueous hybrid supercapacitors. We synthesized SnS2/RGO nanocomposite comprised of nanosheets of SnS2 and graphene oxide via a one-pot hydrothermal approach. in situ as-synthesized SnS2/RGO is devised for the first time to give high specific capacitance 500 Fg-1, energy density 16.67 Wh kg-1 and power density 488 W kg-1. The cell retains 95% charge/discharge cycle stability up to 1000 cycles. In-short, the SnS2/RGO nanosheet composite presented is a novel and advanced material for application in high stability moderate value hybrid supercapacitors. All the currently available surveys in literature state the potential applicability of SnS2 as the anode material for reversible lithium/sodium ion batteries (LIBs/NIBs) but there is a lack of equivalent studies on electrochemical capacitors. We filled up this knowledge gap by the use of the same material in a cost-effective, highly active hybrid supercapacitor application by utilizing its pseudocapacitance property combined with the layered capacitance property of graphene sheets.

  6. Development of SnS2/RGO nanosheet composite for cost-effective aqueous hybrid supercapacitors.

    PubMed

    Chauhan, Himani; Singh, Manoj K; Kumar, Praveen; Hashmi, Safir Ahmad; Deka, Sasanka

    2017-01-13

    The development of low cost supercapacitor cells with unique capacitive properties is essential for many domestic and industrial purposes. Here we report the first ever application of SnS2-reduced graphene oxide (SnS2/RGO) layered nanocomposite as a superior electrode material for symmetric aqueous hybrid supercapacitors. We synthesized SnS2/RGO nanocomposite comprised of nanosheets of SnS2 and graphene oxide via a one-pot hydrothermal approach. in situ as-synthesized SnS2/RGO is devised for the first time to give high specific capacitance 500 Fg(-1), energy density 16.67 Wh kg(-1) and power density 488 W kg(-1). The cell retains 95% charge/discharge cycle stability up to 1000 cycles. In-short, the SnS2/RGO nanosheet composite presented is a novel and advanced material for application in high stability moderate value hybrid supercapacitors. All the currently available surveys in literature state the potential applicability of SnS2 as the anode material for reversible lithium/sodium ion batteries (LIBs/NIBs) but there is a lack of equivalent studies on electrochemical capacitors. We filled up this knowledge gap by the use of the same material in a cost-effective, highly active hybrid supercapacitor application by utilizing its pseudocapacitance property combined with the layered capacitance property of graphene sheets.

  7. Origins of varying carrier concentration in Cu2SnS3 photovoltaic absorbers

    NASA Astrophysics Data System (ADS)

    Baranowski, Lauryn; Zawadzki, Pawel; Lany, Stephan; Tumas, William; Ginley, David; Toberer, Eric; Zakutayev, Andriy

    2014-03-01

    Within the Cu-Sn-S family of earth abundant photovoltaic absorbers, the Cu2SnS3 phase is predicted to be the most promising absorber material [P. Zawadzki, et al.]. To date there has been limited synthetic work on the Cu2SnS3 phase, particularly the carrier concentration. In this study, we develop an understanding of the effects of RF sputtering growth conditions on the hole concentrations of Cu2SnS3 absorber films, and use these results to identify the underlying causes of the observed variations in carrier concentration. Two effects are identified that control the carrier concentration in Cu2SnS3 films. The first effect, which occurs during Cu-rich growth, is isostructural alloying with a metallic Cu3SnS4 phase, which gives rise to hole concentrations above 1019 cm-3. The second effect is that, when the Cu2SnS3 films are grown under Sn-rich conditions, varying the S chemical potential during film deposition gives 1018-1019 cm-3 holes. This variation in carrier concentration with S chemical potential can be explained by a Cu vacancy defect model. Understanding the origins of the varying doping density in Cu2SnS3 films allows for targeted growth to achieve desired carrier concentrations for device integration.

  8. Diagnostic Development on NSTX

    SciTech Connect

    A.L. Roquemore; D. Johnson; R. Kaita; et al

    1999-12-16

    Diagnostics are described which are currently installed or under active development for the newly commissioned NSTX device. The low aspect ratio (R/a less than or equal to 1.3) and low toroidal field (0.1-0.3T) used in this device dictate adaptations in many standard diagnostic techniques. Technical summaries of each diagnostic are given, and adaptations, where significant, are highlighted.

  9. Design and Prototyping of an Ionization Profile Monitor for the SNS Accumulator Ring

    SciTech Connect

    Bartkoski, Dirk A; Deibele, Craig E; Polsky, Yarom

    2014-12-01

    An ionization profile monitor (IPM) has been designed for the Spallation Neutron Source (SNS) accumulator ring. Utilizing ionized electrons produced by beam-gas ionization, the SNS IPM uses a 120 kV bias potential to overcome beam space charge and accelerate electrons towards a movable particle detector. A 300 G magnetic field is used to confine the transverse electron motion, resulting in profile errors at the estimated 7% level. With a system bandwidth of 17.5 MHz. The SNS IPM is capable of measuring turn-by-turn beam profiles for a fully accumulated beam. This paper presents a description of the system and design.

  10. Sol-gel processed Cu2SnS3 films for photovoltaics

    NASA Astrophysics Data System (ADS)

    Dias, Sandra; Banavoth, Murali; Krupanidhi, S. B.

    2013-06-01

    Cu2SnS3 films have been processed by the sol-gel route. Differential Scanning Calorimetry (DSC) study was done to observe the phase transformations and to ascertain the deposition temperature. X-ray diffraction (XRD) confirms the phase formation of Cu2SnS3 . The texture coefficient analysis shows the preferential orientation of the (112) facet. Scanning electron microscopy reveals the morphology of the film. Energy Dispersive Spectroscopy (EDS) was used for compositional studies. Raman spectrum shows the peaks corresponding to the tetragonal phase of Cu2SnS3.

  11. HIGH RESOLUTION EMITTANCE MEASUREMENTS AT SNS FRONT END

    SciTech Connect

    Aleksandrov, Alexander V; Zhukov, Alexander P

    2013-01-01

    The Spallation Neutron Source (SNS) linac accelerates an H- beam from 2.5MeV up to 1GeV. Recently the emittance scanner in the MEBT (2.5 MeV) was upgraded. In addition to the slit - harp measurement, we now can use a slit installed on the same actuator as the harp. In combination with a faraday cup located downstream in DTL part of the linac, it represents a classical slit-slit emittance measurement device. While a slit slit scan takes much longer, it is immune to harp related problems such as wire cross talk, and thus looks promising for accurate halo measurements. Time resolution of the new device seems to be sufficient to estimate the amount of beam in the chopper gap (the scanner is downstream of the chopper), and probably to measure its emittance. This paper describes the initial measurements with the new device and some model validation data.

  12. REDUCING BEAM COUPLING IMPEDANCES IN SNS RING EXTRACTION KICKERS

    SciTech Connect

    S.S. KURENNOY; D. DAVINO; Y. LEE

    2001-06-01

    The Spallation Neutron Source (SNS) Accumulator ring extraction system [1] includes 14 modules of window-frame ferrite pulsing kicker magnets with the rise time of about 200 ns. Their contribution to the beam coupling impedances is a serious concern. The kicker impedances, as well as its deflecting magnetic field versus time, are studied using detailed 3-D MAFIA modeling. Various design options, external circuit resistances, and a range of ferrite permeabilities are explored. A kicker module with wide conductor windings around the ferrite behind the kicker current sheet suggests a significant reduction of the kicker transverse and longitudinal coupling impedances. This design provides a good extraction field performance, as demonstrated by electromagnetic simulations. Results of measurements for a small model are also presented.

  13. REDUCING BEAM COUPLING IMPEDANCES IN SNS RING EXTRACTION KICKERS

    SciTech Connect

    Kurennoy, S.; Davino, D.; Lee, Y. Y.

    2001-01-01

    The Spallation Neutron Source (SNS) Accumulator ring extraction system includes 14 modules of windowframe ferrite pulsing kicker magnets with the rise time of about 200 ns. Their contribution to the beam coupling impedances is a serious concern. The kicker impedances, as well as its deflecting magnetic field versus time, are studied using detailed 3-D MAFIA modeling. Various design options, external circuit resistances, and a range of ferrite permeabilities are explored. A kicker module with wide conductor windings around the ferrite behind the kicker current sheet suggests a significant reduction of the kicker transverse and longitudinal coupling impedances. This design provides a good extraction field performance, as demonstrated by electromagnetic simulations. Results of measurements for a small model are also presented.

  14. Error studies for SNS Linac. Part 1: Transverse errors

    SciTech Connect

    Crandall, K.R.

    1998-12-31

    The SNS linac consist of a radio-frequency quadrupole (RFQ), a drift-tube linac (DTL), a coupled-cavity drift-tube linac (CCDTL) and a coupled-cavity linac (CCL). The RFQ and DTL are operated at 402.5 MHz; the CCDTL and CCL are operated at 805 MHz. Between the RFQ and DTL is a medium-energy beam-transport system (MEBT). This error study is concerned with the DTL, CCDTL and CCL, and each will be analyzed separately. In fact, the CCL is divided into two sections, and each of these will be analyzed separately. The types of errors considered here are those that affect the transverse characteristics of the beam. The errors that cause the beam center to be displaced from the linac axis are quad displacements and quad tilts. The errors that cause mismatches are quad gradient errors and quad rotations (roll).

  15. H- AND PROTON BEAM LOSS COMPARISON AT SNS SUPERCONDUCTING LINAC

    SciTech Connect

    Aleksandrov, Alexander V; Galambos, John D; Plum, Michael A; Shishlo, Andrei P

    2012-01-01

    A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H- and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H- + H- -> H- + H0 + e is presented. Earlier, a short description of these studies was presented in [1].

  16. SNS Ring Operational Experience and Power Ramp Up Status

    SciTech Connect

    Plum, Michael A

    2009-01-01

    The SNS Ring has now been operating for about 3.5 years, and our march continues to increase the beam power to the full design value of 1.4 MW. The Ring is a loss-limited machine, and in general the radioactivation levels are good, but there are some unanticipated hot spots that we are working to improve. High intensity collective effects such as space-charge and beam instability have had minimal impact on beam operations to date. The cross plane coupling issue in the ring to target beam transport line has been solved. We will also discuss the status of equipment upgrades in the high-energy beam transport beam line, the injection-dump beam transport line, the ring, and the ring-to-target beam transport line.

  17. SEQUOIA: A Newly Operating Chopper Spectrometer at the SNS

    SciTech Connect

    Kolesnikov, Alexander I; Sherline, Todd E; Clancy, James P; Ross, Kathyrn; Ruff, Jacob; Gaulin, Bruce D.; Nagler, Stephen E

    2010-01-01

    A fine resolution chopper spectrometer (SEQUOIA) recently received first neutrons at the SNS. The commissioning phase of the instrument is underway. SEQUOIA is designed to utilize neutrons of an incident energy (Ei) between 10-2000 meV. A monochromatic beam is provided on a sample, 20 m from the decoupled ambient temperature H2O moderator, by filtering the white beam with a Fermi chopper located 18 m from the source. After interacting with the sample, neutrons are detected by an array of 3He linear position sensitive tubes located on a vertical cylinder with a radius of 5.5 m. This contribution presents current results from the commissioning experiments and compares SEQUOIA s actual and predicted performance. These commissioning experiments include characterization of the beam by monitors, determination of the chopper phase offsets, and runs with V and C4H2I2S. The predicted performance is provided by analytical calculations and Monte Carlo simulations.

  18. Self-catalytic solution-liquid-liquid-solid (SLLS) growth of tapered SnS nanorods

    NASA Astrophysics Data System (ADS)

    Cho, Ki-Hyun; Sung, Yun-Mo

    2013-04-01

    Taper-shaped SnS nanorods were synthesized via mild chemistry, and the self-catalytic solution-liquid-liquid-solid (SLLS) process was proposed as a crystal growth mechanism. There exists a distinct difference in our SLLS growth compared to the well-known SLS growth in that we injected Sn precursors into a hot trioctylphosphine sulfide (TOPS) solution, which is a reverse process of the general SLS growth. This reverse process could prevent the oxidation of Sn precursors and thus it could facilitate the growth of SnS nanorods, since the surface of Sn clusters and droplets could be momentarily passivated by TOPS molecules. Without addition of extra catalyst nanoparticles, the nucleation and growth of SnS nanorods was induced by liquid Sn droplets. Spherical Sn tips existing at the top of the nanorods evidence the self-catalytic growth. The SLLS growth was proposed based upon the large Sn clusters existing at the bottom of the SnS nanorods in an intermediate stage (5 s) of the growth and the tapered morphology of the nanorods. The growth of SnS nanorods could progress by the upward diffusion of Sn atoms from large liquid Sn clusters along the surface of the SnS nanorods to the interfacial liquid layers (neck area) and the diffusion of S decomposed from TOPS in the solution to the neck area. SnS nanorods showed a direct energy band gap of ~1.6 eV, determined by using the Kubelka-Munk transformation of UV-visible spectra. This self-catalytic SLLS growth produced high-quality and single crystalline SnS nanorods within only 15 s at 290 °C.Taper-shaped SnS nanorods were synthesized via mild chemistry, and the self-catalytic solution-liquid-liquid-solid (SLLS) process was proposed as a crystal growth mechanism. There exists a distinct difference in our SLLS growth compared to the well-known SLS growth in that we injected Sn precursors into a hot trioctylphosphine sulfide (TOPS) solution, which is a reverse process of the general SLS growth. This reverse process could

  19. The RF power system for the SNS linac

    SciTech Connect

    Tallerico, P.J.; Reass, W.A.

    1998-12-31

    The initial goal of the SNS project is to produce a 1 MW average beam of protons with short pulse lengths onto a neutron-producing target. The objective of the SNS RF system is to generate 117 MW peak of pulsed 805 MHz microwave power with an accelerated beam pulse length of 1.04 ms at a 60 Hz repetition rate. The power system must be upgradeable in peak power to deliver 2 MW average power to the neutron target. The RF system also requires about 3 MW peak of RF power at 402.5 MHz, but that system is not discussed here. The design challenge is to produce an RF system at minimum cost, that is very reliable and economical to operate. The combination of long pulses and high repetition rates make conventional solutions, such as the pulse transformer and transmission line method, very expensive. The klystron, with a modulating anode, and 1.5 MW of peak output power is the baseline RF amplifier, an 56 are required in the baseline design. The authors discuss four power system configurations that are the candidates for the design. The baseline design is a floating-deck modulating anode system. A second power system being investigated is the fast-pulsed power supply, that can be turned on and off with a rise time of under 0.1 ms. This could eliminate the need for a modulator, and drastically reduce the energy storage requirements. A third idea is to use a pulse transformer with a series IGBT switch and a bouncer circuit on the primary side, as was done for the TESLA modulator. A fourth method is to use a series IGBT switch at high voltage, and not use a pulse transformer. The authors discuss the advantages and problems of these four types of power systems, but they emphasize the first two.

  20. Electrical and optical properties of SnS2/WSe2 van der Waals Heterojunction FETs

    NASA Astrophysics Data System (ADS)

    Zubair, Ahmad; Nourbakhsh, Amirhasan; Dresselhaus, Mildred; Palacios, Tomas

    Two dimensional crystals based on atomically thin films of transition metal dichalcogenides offer an exciting platform for various optoelectronic applications. Their unique crystal properties make them particularly attractive for van der Waals heterostructures which open up an additional degree of freedom to tailor the material properties into new physics and device applications. In this work, we explore, for the first time, the optoelectronic properties of van der Waals SnS2/WSe2 heterojunction. WSe2 is an ambipolar semiconductor while SnS2 is an n-type wide bandgap semiconductor. We use the pickup and dry transfer methods to fabricate SnS2/WSe2 heterojunction transistors (hetero-FETs). We observe negative differential transconductance in the SnS2/WSe2 hetero-FET. Also, the heterostructure couples strongly to incident light and shows high photovoltaic responsivity which can find applications in nano-devices such as photo-detectors and solar cells.

  1. Raman analysis of monoclinic Cu2SnS3 thin films

    NASA Astrophysics Data System (ADS)

    Berg, Dominik M.; Djemour, Rabie; Gütay, Levent; Siebentritt, Susanne; Dale, Phillip J.; Fontane, Xavier; Izquierdo-Roca, Victor; Pérez-Rodriguez, Alejandro

    2012-05-01

    Secondary phases like Cu2SnS3 are major obstacles for kesterite thin film solar cell applications. We prepare Cu2SnS3 using identical annealing conditions as used for the kesterite films. By x-ray diffraction, the crystal structure of Cu2SnS3 was identified as monoclinic. Polarization-dependent Raman investigations allowed the identification of the dominant peaks at 290 cm-1 and 352 cm-1 with the main A' symmetry vibrational modes from the monoclinic Cu2SnS3 phase. Furthermore, micro-resolved Raman investigations revealed local variations in the spectra that are attributed to a secondary phase (possibly Cu2Sn3S7). This exemplifies the abilities of micro-resolved Raman measurements in the detection of secondary phases.

  2. Bifacial solar cell with SnS absorber by vapor transport deposition

    SciTech Connect

    Wangperawong, Artit; Hsu, Po-Chun; Yee, Yesheng; Herron, Steven M.; Clemens, Bruce M.; Cui, Yi; Bent, Stacey F.

    2014-10-27

    The SnS absorber layer in solar cell devices was produced by vapor transport deposition (VTD), which is a low-cost manufacturing method for solar modules. The performance of solar cells consisting of Si/Mo/SnS/ZnO/indium tin oxide (ITO) was limited by the SnS layer's surface texture and field-dependent carrier collection. For improved performance, a fluorine doped tin oxide (FTO) substrate was used in place of the Mo to smooth the topography of the VTD SnS and to make bifacial solar cells, which are potentially useful for multijunction applications. A bifacial SnS solar cell consisting of glass/FTO/SnS/CdS/ZnO/ITO demonstrated front- and back-side power conversion efficiencies of 1.2% and 0.2%, respectively.

  3. Self-catalytic solution-liquid-liquid-solid (SLLS) growth of tapered SnS nanorods.

    PubMed

    Cho, Ki-Hyun; Sung, Yun-Mo

    2013-05-07

    Taper-shaped SnS nanorods were synthesized via mild chemistry, and the self-catalytic solution-liquid-liquid-solid (SLLS) process was proposed as a crystal growth mechanism. There exists a distinct difference in our SLLS growth compared to the well-known SLS growth in that we injected Sn precursors into a hot trioctylphosphine sulfide (TOPS) solution, which is a reverse process of the general SLS growth. This reverse process could prevent the oxidation of Sn precursors and thus it could facilitate the growth of SnS nanorods, since the surface of Sn clusters and droplets could be momentarily passivated by TOPS molecules. Without addition of extra catalyst nanoparticles, the nucleation and growth of SnS nanorods was induced by liquid Sn droplets. Spherical Sn tips existing at the top of the nanorods evidence the self-catalytic growth. The SLLS growth was proposed based upon the large Sn clusters existing at the bottom of the SnS nanorods in an intermediate stage (5 s) of the growth and the tapered morphology of the nanorods. The growth of SnS nanorods could progress by the upward diffusion of Sn atoms from large liquid Sn clusters along the surface of the SnS nanorods to the interfacial liquid layers (neck area) and the diffusion of S decomposed from TOPS in the solution to the neck area. SnS nanorods showed a direct energy band gap of ∼1.6 eV, determined by using the Kubelka-Munk transformation of UV-visible spectra. This self-catalytic SLLS growth produced high-quality and single crystalline SnS nanorods within only 15 s at 290 °C.

  4. Effects of Na and secondary phases on physical properties of SnS thin film after sulfurization process

    NASA Astrophysics Data System (ADS)

    Kawano, Yu; Kodani, Yuto; Chantana, Jakapan; Minemoto, Takashi

    2016-09-01

    2.48%-efficient SnS thin film solar cell is obtained under thermal evaporation method by optimizing growth temperature. The method to fabricate SnS films is limited by growth temperature, which should not be over 200 °C to prevent re-evaporation of SnS. To further enhance SnS grains, SnS films were annealed in H2S gas from 200 to 500 °C, namely sulfurization process. SnS grain size was increased with sulfurization temperature of above 400 °C however, secondary phase grains on film’s surface were observed owing to the accumulated Na, diffused from soda-lime glass substrate into the film, thus deteriorating film’s quality, implied by Urbach energy.

  5. Thickness-dependent structure and properties of SnS2 thin films prepared by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Seo, Wondeok; Shin, Seokyoon; Ham, Giyul; Lee, Juhyun; Lee, Seungjin; Choi, Hyeongsu; Jeon, Hyeongtag

    2017-03-01

    Tin disulfide (SnS2) thin films were deposited by a thermal atomic layer deposition (ALD) method at low temperatures. The physical, chemical, and electrical characteristics of SnS2 were investigated as a function of the film thickness. SnS2 exhibited a (001) hexagonal plane peak at 14.9° in the X-ray diffraction (XRD) results and an A1g peak at 311 cm‑1 in the Raman spectra. These results demonstrate that SnS2 thin films grown at 150 °C showed a crystalline phase at film thicknesses above 11.2 nm. The crystallinity of the SnS2 thin films was evaluated by a transmission electron microscope (TEM). The X-ray photoelectron spectroscopy (XPS) analysis revealed that SnS2 consisted of Sn4+ and S2‑ valence states. Both the optical band gap and the transmittance of SnS2 decreased as the film thickness increased. The band gap of SnS2 decreased from 3.0 to 2.4 eV and the transmittance decreased from 85 to 32% at a wavelength of 400 nm. In addition, the resistivity of the thin film SnS2 decreased from 1011 to 106 Ω·cm as the film thickness increased.

  6. DOUBLE-WALL COLLIMATOR DESIGN OF THE SNS PROJECT.

    SciTech Connect

    SIMOS,N.; LUDEWIG,H.; CATALAN-LASHERAS,N.; CRIVELLO,S.

    2001-06-18

    The collimator absorber array of the Spallation Neutron Source (SNS) project is responsible for stopping the 1.0 GeV protons that are in the halo of the beam. It is estimated that 0.1% of the 2 MW beam will be intercepted by the adopted collimating scheme implemented at various sections of the beam transport and accumulation. This paper summarizes the conceptual design of the collimator absorber as well as the supporting detailed analysis that were performed and guided the design process. Key requirement in the design process is the need for the collimator beam tube to minimize beam impedance while closely following its beta function. Due to lack of available experimental data, the long-term behavior of irradiated materials in an environment where they interface with coolant flow becomes an issue. Uncertainties in the long-term behavior prompted a special double-wall design that will enable not only beam halo interception but also the efficient transfer of deposited energy both under normal and off-normal conditions to the coolant flow. The thermo-mechanical response of the double wall beam tube and of a particle bed surrounding it are discussed in detail in the paper.

  7. Rotating Target Development for SNS Second Target Station

    SciTech Connect

    McManamy, Thomas J; Rennich, Mark J; Crawford, Roy K; Geoghegan, Patrick J; Janney, Jim G

    2010-01-01

    A rotating target for the second target station (STS) at SNS has been identified as an option along with a mercury target. Evaluation of the rotating target alternative for STS has started at 1.5 MW which is considered an upper bound for the power. Previous preconceptual design work for a 3 MW rotating target is being modified for the lower power level. Transient thermal analysis for a total loss of active water cooling has been done for a simplified 2D model of the target and shielding monolith which shows that peak temperatures are well below the level at which tungsten vaporization by steam could exceed site boundary dose limits. Design analysis and integration configuration studies have been done for the target-moderator-reflector assembly which maximizes the number of neutron beam lines and provides for replacement of the target and moderators. Target building hot cell arrangement for this option will be described. An option for operation in rough vacuum without a proton beam window using Ferro fluid seals on a vertical shaft is being developed. A full scale prototypic drive module based on the 3 MW preconceptual design has been fabricated and successfully tested with a shaft and mock up target supplied by the ESS-Bilbao team. Overall planning leading to decision between mercury and the rotating target in 2011 will be discussed

  8. Advanced Gate Drive for the SNS High Voltage Converter Modulator

    SciTech Connect

    Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; Anderson, D.E.; /Oak Ridge

    2009-05-07

    SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.

  9. Bilayer SnS2: Tunable stacking sequence by charging and loading pressure

    NASA Astrophysics Data System (ADS)

    Bacaksiz, C.; Cahangirov, S.; Rubio, A.; Senger, R. T.; Peeters, F. M.; Sahin, H.

    2016-03-01

    Employing density functional theory-based methods, we investigate monolayer and bilayer structures of hexagonal SnS2, which is a recently synthesized monolayer metal dichalcogenide. Comparison of the 1 H and 1 T phases of monolayer SnS2 confirms the ground state to be the 1 T phase. In its bilayer structure we examine different stacking configurations of the two layers. It is found that the interlayer coupling in bilayer SnS2 is weaker than that of typical transition-metal dichalcogenides so that alternative stacking orders have similar structural parameters and they are separated with low energy barriers. A possible signature of the stacking order in the SnS2 bilayer has been sought in the calculated absorbance and reflectivity spectra. We also study the effects of the external electric field, charging, and loading pressure on the characteristic properties of bilayer SnS2. It is found that (i) the electric field increases the coupling between the layers at its preferred stacking order, so the barrier height increases, (ii) the bang gap value can be tuned by the external E field and under sufficient E field, the bilayer SnS2 can become a semimetal, (iii) the most favorable stacking order can be switched by charging, and (iv) a loading pressure exceeding 3 GPa changes the stacking order. The E-field tunable band gap and easily tunable stacking sequence of SnS2 layers make this 2D crystal structure a good candidate for field effect transistor and nanoscale lubricant applications.

  10. 78 FR 32612 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility... previously published Notice of Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment...

  11. 78 FR 16448 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility... previously published Notice of Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment...

  12. 77 FR 67595 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility... Rulemaking (NPRM) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee will meet...

  13. 78 FR 23872 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility... previously published Notice of Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment...

  14. 78 FR 1166 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility... previously published Notice of Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment...

  15. 78 FR 10582 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-14

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility... previously published Notice of Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment...

  16. Unlocking the potential of SnS2: Transition metal catalyzed utilization of reversible conversion and alloying reactions

    NASA Astrophysics Data System (ADS)

    Huang, Zhi Xiang; Wang, Ye; Liu, Bo; Kong, Dezhi; Zhang, Jun; Chen, Tupei; Yang, Hui Ying

    2017-01-01

    The alloying-dealloying reactions of SnS2 proceeds with the initial conversion reaction of SnS2 with lithium that produces Li2S. Unfortunately, due to the electrochemical inactivity of Li2S, the conversion reaction of SnS2 is irreversible, which significantly limit its potential applications in lithium-ion batteries. Herein, a systematic understanding of transition metal molybdenum (Mo) as a catalyst in SnS2 anode is presented. It is found that Mo catalyst is able to efficiently promote the reversible conversion of Sn to SnS2. This leads to the utilization of both conversion and alloying reactions in SnS2 that greatly increases lithium storage capability of SnS2. Mo catalyst is introduced in the form of MoS2 grown directly onto self-assembled vertical SnS2 nanosheets that anchors on three-dimensional graphene (3DG) creating a hierarchal nanostructured named as SnS2/MoS2/3DG. The catalytic effect results in a significantly enhanced electrochemical properties of SnS2/MoS2/3DG; a high initial Coulombic efficiency (81.5%) and high discharge capacities of 960.5 and 495.6 mA h g‑1 at current densities of 50 and 1000 mA g‑1, respectively. Post cycling investigations using ex situ TEM and XPS analysis verifies the successful conversion reaction of SnS2 mediated by Mo. The successful integration of catalyst on alloying type metal sulfide anode creates a new avenue towards high energy density lithium anodes.

  17. Unlocking the potential of SnS2: Transition metal catalyzed utilization of reversible conversion and alloying reactions.

    PubMed

    Huang, Zhi Xiang; Wang, Ye; Liu, Bo; Kong, Dezhi; Zhang, Jun; Chen, Tupei; Yang, Hui Ying

    2017-01-19

    The alloying-dealloying reactions of SnS2 proceeds with the initial conversion reaction of SnS2 with lithium that produces Li2S. Unfortunately, due to the electrochemical inactivity of Li2S, the conversion reaction of SnS2 is irreversible, which significantly limit its potential applications in lithium-ion batteries. Herein, a systematic understanding of transition metal molybdenum (Mo) as a catalyst in SnS2 anode is presented. It is found that Mo catalyst is able to efficiently promote the reversible conversion of Sn to SnS2. This leads to the utilization of both conversion and alloying reactions in SnS2 that greatly increases lithium storage capability of SnS2. Mo catalyst is introduced in the form of MoS2 grown directly onto self-assembled vertical SnS2 nanosheets that anchors on three-dimensional graphene (3DG) creating a hierarchal nanostructured named as SnS2/MoS2/3DG. The catalytic effect results in a significantly enhanced electrochemical properties of SnS2/MoS2/3DG; a high initial Coulombic efficiency (81.5%) and high discharge capacities of 960.5 and 495.6 mA h g(-1) at current densities of 50 and 1000 mA g(-1), respectively. Post cycling investigations using ex situ TEM and XPS analysis verifies the successful conversion reaction of SnS2 mediated by Mo. The successful integration of catalyst on alloying type metal sulfide anode creates a new avenue towards high energy density lithium anodes.

  18. Unlocking the potential of SnS2: Transition metal catalyzed utilization of reversible conversion and alloying reactions

    PubMed Central

    Huang, Zhi Xiang; Wang, Ye; Liu, Bo; Kong, Dezhi; Zhang, Jun; Chen, Tupei; Yang, Hui Ying

    2017-01-01

    The alloying-dealloying reactions of SnS2 proceeds with the initial conversion reaction of SnS2 with lithium that produces Li2S. Unfortunately, due to the electrochemical inactivity of Li2S, the conversion reaction of SnS2 is irreversible, which significantly limit its potential applications in lithium-ion batteries. Herein, a systematic understanding of transition metal molybdenum (Mo) as a catalyst in SnS2 anode is presented. It is found that Mo catalyst is able to efficiently promote the reversible conversion of Sn to SnS2. This leads to the utilization of both conversion and alloying reactions in SnS2 that greatly increases lithium storage capability of SnS2. Mo catalyst is introduced in the form of MoS2 grown directly onto self-assembled vertical SnS2 nanosheets that anchors on three-dimensional graphene (3DG) creating a hierarchal nanostructured named as SnS2/MoS2/3DG. The catalytic effect results in a significantly enhanced electrochemical properties of SnS2/MoS2/3DG; a high initial Coulombic efficiency (81.5%) and high discharge capacities of 960.5 and 495.6 mA h g−1 at current densities of 50 and 1000 mA g−1, respectively. Post cycling investigations using ex situ TEM and XPS analysis verifies the successful conversion reaction of SnS2 mediated by Mo. The successful integration of catalyst on alloying type metal sulfide anode creates a new avenue towards high energy density lithium anodes. PMID:28102356

  19. Analysis of SnS2 hyperdoped with V proposed as efficient absorber material.

    PubMed

    Seminovski, Yohanna; Palacios, Pablo; Wahnón, Perla

    2014-10-01

    Intermediate-band materials can improve the photovoltaic efficiency of solar cells through the absorption of two subband-gap photons that allow extra electron-hole pair formations. Previous theoretical and experimental findings support the proposal that the layered SnS2 compound, with a band-gap of around 2 eV, is a candidate for an intermediate-band material when it is doped with a specific transition-metal. In this work we characterize vanadium doped SnS2 using density functional theory at the dilution level experimentally found and including a dispersion correction combined with the site-occupancy-disorder method. In order to analyze the electronic characteristics that depend on geometry, two SnS2 polytypes partially substituted with vanadium in symmetry-adapted non-equivalent configurations were studied. In addition the magnetic configurations of vanadium in a SnS2 2H-polytype and its comparison with a 4H-polytype were also characterized. We demonstrate that a narrow intermediate-band is formed, when these dopant atoms are located in different layers. Our theoretical predictions confirm the recent experimental findings in which a paramagnetic intermediate-band material in a SnS2 2H-polytype with 10% vanadium concentration is obtained.

  20. Analysis of SnS2 hyperdoped with V proposed as efficient absorber material

    NASA Astrophysics Data System (ADS)

    Seminovski, Yohanna; Palacios, Pablo; Wahnón, Perla

    2014-10-01

    Intermediate-band materials can improve the photovoltaic efficiency of solar cells through the absorption of two subband-gap photons that allow extra electron-hole pair formations. Previous theoretical and experimental findings support the proposal that the layered SnS2 compound, with a band-gap of around 2 eV, is a candidate for an intermediate-band material when it is doped with a specific transition-metal. In this work we characterize vanadium doped SnS2 using density functional theory at the dilution level experimentally found and including a dispersion correction combined with the site-occupancy-disorder method. In order to analyze the electronic characteristics that depend on geometry, two SnS2 polytypes partially substituted with vanadium in symmetry-adapted non-equivalent configurations were studied. In addition the magnetic configurations of vanadium in a SnS2 2H-polytype and its comparison with a 4H-polytype were also characterized. We demonstrate that a narrow intermediate-band is formed, when these dopant atoms are located in different layers. Our theoretical predictions confirm the recent experimental findings in which a paramagnetic intermediate-band material in a SnS2 2H-polytype with 10% vanadium concentration is obtained.

  1. The SNS/HFIR Web Portal System for SANS

    SciTech Connect

    Campbell, Stuart I; Miller, Stephen D; Bilheux, Jean-Christophe; Reuter, Michael A; Peterson, Peter F; Kohl, James Arthur; Trater, James R; Vazhkudai, Sudharshan S; Lynch, Vickie E

    2010-01-01

    In a busy world, continuing with the status-quo, to do things the way we are already familiar, often seems to be the most efficient way to conduct our work. We look for the value-add to decide if investing in a new method is worth the effort. How shall we evaluate if we have reached this tipping point for change? For contemporary researchers, understanding the properties of the data is a good starting point. The new generation of neutron scattering instruments being built are higher resolution and produce one or more orders of magnitude larger data than the previous generation of instruments. For instance, we have grown out of being able to perform some important tasks with our laptops the data are too big and the computations would simply take too long. These large datasets can be problematic as facility users now begin to grapple with many of the same issues faced by more established computing communities. These issues include data access, management, and movement, data format standards, distributed computing, and collaboration among others. The Neutron Science Portal has been architected, designed, and implemented to provide users with an easy-to-use interface for managing and processing data, while also keeping an eye on meeting modern cybersecurity requirements imposed on institutions. The cost of entry for users has been lowered by utilizing a web interface providing access to backend portal resources. Users can browse or search for data which they are allowed to see, data reduction applications can be run without having to load the software, sample activation calculations can be performed for SNS and HFIR beamlines, McStas simulations can be run on TeraGrid and ORNL computers, and advanced analysis applications such as those being produced by the DANSE project can be run. Behind the scenes is a live cataloging system which automatically catalogs and archives experiment data via the data management system, and provides proposal team members access to their

  2. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2011-01-01

    This article presents summaries of three articles relevant to school crisis response: (1) "Factors Contributing to Posttraumatic Growth," summarized by Steve DeBlois; (2) "Psychological Debriefing in Cross-Cultural Contexts" (Stacey Rice); and (3) "Brain Abnormalities in PTSD" (Sunny Windingstad). The first summary reports the findings of a…

  3. Solid state synthesis and spectral investigations of nanostructure SnS2.

    PubMed

    Kiruthigaa, G; Manoharan, C; Raju, C; Jayabharathi, J; Dhanapandian, S

    2014-08-14

    Nanometer sized SnS2 particles were synthesised by solid state reaction between tin chloride and thiourea in air at 150-350°C. The structural, morphological and optical properties were characterized by using X-ray diffraction (XRD), FT-IR, FT-Raman, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) and UV-Vis spectra. The X-ray diffraction (XRD) pattern of the product was indexed to the hexagonal phase of SnS2. Crystallite size, microstrain and dislocation density were evaluated from the XRD data. EDS analysis indicated that the elemental ratio was similar to tin disulphide (SnS2). The blue shift in the absorption edge was observed from the UV-Vis spectrum. The photoluminescence spectra showed two emission peaks corresponding to blue and red emission.

  4. Solid state synthesis and spectral investigations of nanostructure SnS2

    NASA Astrophysics Data System (ADS)

    Kiruthigaa, G.; Manoharan, C.; Raju, C.; Jayabharathi, J.; Dhanapandian, S.

    2014-08-01

    Nanometer sized SnS2 particles were synthesised by solid state reaction between tin chloride and thiourea in air at 150-350 °C. The structural, morphological and optical properties were characterized by using X-ray diffraction (XRD), FT-IR, FT-Raman, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) and UV-Vis spectra. The X-ray diffraction (XRD) pattern of the product was indexed to the hexagonal phase of SnS2. Crystallite size, microstrain and dislocation density were evaluated from the XRD data. EDS analysis indicated that the elemental ratio was similar to tin disulphide (SnS2). The blue shift in the absorption edge was observed from the UV-Vis spectrum. The photoluminescence spectra showed two emission peaks corresponding to blue and red emission.

  5. Properties of SnS thin films grown by physical vapour deposition

    NASA Astrophysics Data System (ADS)

    Ganchev, M.; Vitanov, P.; Sendova-Vassileva, M.; Popkirov, G.; Dikov, H.

    2016-02-01

    Thin films of tin sulfide (SnS) were prepared by thermal evaporation technique on glass substrates and on n-type Si substrate and their physical properties were studied. The phase of the obtained thin films before and after thermal treatment was confirmed by X-ray diffraction analysis and Raman spectra. Optical transmission and reflection spectra were measured in the wavelength range 300-1800 nm, and the data were used to determine the direct and indirect optical band gaps. Four-point measurements have revealed that SnS thin film exhibits p-type conduction. Current-voltage characteristics of the SnS/ n-Si structures demonstrate strong photosensitivity and photovoltaic effect. However, in order to be able to evaluate the potential applicability of this heterojunction for photovoltaic or electronic devices, further study and technological optimization has to be conducted.

  6. A QUEST FOR SYSTEM FRIENDLINESS WITH THE SNS ION BEAM BUNCH SHAPE MONITOR

    SciTech Connect

    Dickson, Richard W; Aleksandrov, Alexander V

    2012-01-01

    A new system for measuring the SNS ion beam longitudinal profile was recently upgraded to operational status. The hardware for this device was developed and delivered by Institute of Nuclear Research to the SNS as a part of its initial construction. The supplied LabVIEW user interface software was intended for proof-of-operation and initial setup of the instrument. While satisfactory for this, it was tedious to use in a practical context and lacked any form of interface to the SNS EPICS based control system. This paper will describe the software features added to make this instrument both easily tunable to the prevalent beam conditions by system engineers and easily usable by accelerator physicists only interested in its output data.

  7. Beam Loss due to Foil Scattering in the SNS Accumulator Ring

    SciTech Connect

    Holmes, Jeffrey A; Plum, Michael A

    2012-01-01

    In order to better understand the contribution of scattering from the primary stripper foil to losses in the SNS ring, we have carried out calculations using the ORBIT Code aimed at evaluating these losses. These calculations indicate that the probability of beam loss within one turn following a foil hit is ~1.8 10-8 , where is the foil thickness in g/cm2, assuming a carbon foil. Thus, for a typical SNS stripper foil of thickness = 390 g/cm2, the probability of loss within one turn of a foil hit is ~7.0 10-6. This note describes the calculations used to arrive at this result, presents the distribution of these losses around the SNS ring, and compares the calculated results with observed ring losses for a well-tuned production beam.

  8. Development of the activation analysis calculational methodology for the Spallation Neutron Source (SNS)

    SciTech Connect

    Odano, N.; Johnson, J.O.; Charton, L.A.; Barnes, J.M.

    1998-03-01

    For the design of the proposed Spallation Neutron Source (SNS), activation analyses are required to determine the radioactive waste streams, on-line material processing requirements remote handling/maintenance requirements, potential site contamination and background radiation levels. For the conceptual design of the SNS, the activation analyses were carried out using the high-energy transport code HETC96 coupled with MCNP to generate the required nuclide production rates for the ORIHET95 isotope generation code. ORIHET95 utilizes a matrix-exponential method to study the buildup and decay of activities for any system for which the nuclide production rates are known. In this paper, details of the developed methodology adopted for the activation analyses in the conceptual design of the SNS are presented along with some typical results of the analyses.

  9. Structural stability and electronic properties of low-index surfaces of SnS

    SciTech Connect

    Tritsaris, Georgios A.; Malone, Brad D.; Kaxiras, Efthimios

    2014-05-07

    Thin film photovoltaic cells are increasingly important for cost-effective solar energy harvesting. Layered SnS is a promising absorber material due to its high optical absorption in the visible and good doping characteristics. We use first-principles calculations based on density functional theory to study structures of low-index surfaces of SnS using stoichiometric and oxygen-containing structural models, in order to elucidate their possible effect on the efficiency of the photovoltaic device. We find that the surface energy is minimized for the surface with orientation parallel to the layer stacking direction. Compared to stoichiometric surfaces, the oxygen-containing surfaces exhibit fewer electronic states near the band gap. This reduction of near-gap surface states by oxygen should reduce recombination losses at grain boundaries and interfaces of the SnS absorber, and should be beneficial to the efficiency of the solar cell.

  10. KF addition to Cu2SnS3 thin films prepared by sulfurization process

    NASA Astrophysics Data System (ADS)

    Nakashima, Mitsuki; Fujimoto, Junya; Yamaguchi, Toshiyuki; Sasano, Junji; Izaki, Masanobu

    2017-04-01

    Cu2SnS3 thin films were fabricated by sulfurization with KF addition and applied to photovoltaic devices. Two methods, two-stage annealing and the use of four-layer precursors, were employed, and the quantity of NaF and KF and the annealing temperature were changed. By electron probe microanalysis (EPMA), the Cu/Sn mole ratio was found to range from 0.81 to 1.51. The X-ray diffraction (XRD) patterns and Raman spectra indicated that the fabricated thin films had a monoclinic Cu2SnS3 structure. The Cu2SnS3 thin films fabricated by two-stage annealing had a close-packed structure and a pinhole-free surface morphology. The best solar cell in this study showed V oc of 293 mV, which surpassed the previously reported value.

  11. Carbon dots decorated vertical SnS2 nanosheets for efficient photocatalytic oxygen evolution

    NASA Astrophysics Data System (ADS)

    Cheng, Zhongzhou; Wang, Fengmei; Shifa, Tofik Ahmed; Liu, Kaili; Huang, Yun; Liu, Quanlin; Jiang, Chao; He, Jun

    2016-08-01

    Metal sulfides are highly desirable materials for photocatalytic water splitting because of their appropriate energy bands. However, the poor stability under light illumination in water hinders their wide applications. Here, two-dimensional SnS2 nanosheets, along with carbon dots of the size around 10 nm, are uniformly grown on fluorine doped tin oxide glasses with a layer of nickel nanoparticles. Significantly, strong light absorption and enhanced photocurrent density are achieved after integration of SnS2 nanosheets with carbon dots. Notably, the rate of oxygen evolution reached up to 1.1 mmol g-1 h-1 under simulated sunlight irradiation featuring a good stability.

  12. Mining Archived HYSPEC User Data to Analyze the Prompt Pulse at the SNS

    SciTech Connect

    Smith, Michael B.; Iverson, Erik B.; Gallmeier, Franz X.; Winn, Barry L.

    2015-10-01

    The Hybrid-Spectrometer (HYSPEC) is one of 17 instruments currently operated at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratories (ORNL). The secondary spectrometer of this instrument is located inside an out-building off the north side of the SNS instrument hall. HYSPEC has experienced a larger background feature than similar inelastic instruments since its commissioning in 2011. This background feature is caused by a phenomenon known as the “prompt pulse” which is an essential part of neutron production in a pulsed spallation source but comes with unfortunate side effects.

  13. Cross Space: The Exploration of SNS-Based Writing Activities in a Multimodal Learning Environment

    ERIC Educational Resources Information Center

    Lee, Kwang-Soon; Kim, Bong-Gyu

    2016-01-01

    This study explores the positive learning effect of formulating English sentences via Social Network Service (SNS; "Kakao-Talk") on less proficient L2 university students' (LPSs') writing, when the application is utilized as a tool to link in and out-of class activities in a multimodal-learning environment. Its objective is also to…

  14. BEAM-LOSS DRIVEN DESIGN OPTIMIZATION FOR THE SPALLATION NEUTRON SOURCE (SNS) RING.

    SciTech Connect

    WEI,J.; BEEBE-WANG,J.; BLASKIEWICZ,M.; CAMERON,P.; DANBY,G.; GARDNER,C.J.; JACKSON,J.; LEE,Y.Y.; LUDEWIG,H.; MALITSKY,N.; RAPARIA,D.; TSOUPAS,N.; WENG,W.T.; ZHANG,S.Y.

    1999-03-29

    This paper summarizes three-stage design optimization for the Spallation Neutron Source (SNS) ring: linear machine design (lattice, aperture, injection, magnet field errors and misalignment), beam core manipulation (painting, space charge, instabilities, RF requirements), and beam halo consideration (collimation, envelope variation, e-p issues etc.).

  15. Research on SNS and Education: The State of the Art and Its Challenges

    ERIC Educational Resources Information Center

    Rodríguez-Hoyos, Carlos; Haya Salmón, Ignacio; Fernández-Díaz, Elia

    2015-01-01

    This paper presents, for further discussion, a review of the scientific literature produced internationally on the use of Social Network Sites (SNS) in different levels of education and settings. A total of 62 articles published in international scientific journals with peer review have been analysed. The main objective of this paper is to discuss…

  16. Solid-State Fabrication of SnS2/C Nanospheres for High-Performance Sodium Ion Battery Anode.

    PubMed

    Wang, Jingjing; Luo, Chao; Mao, Jianfeng; Zhu, Yujie; Fan, Xiulin; Gao, Tao; Mignerey, Alice C; Wang, Chunsheng

    2015-06-03

    Tin disulfide (SnS2) has emerged as a promising anode material for sodium ion batteries (NIBs) due to its unique layered structure, high theoretical capacity, and low cost. Conventional SnS2 nanomaterials are normally synthesized using hydrothermal method, which is time-consuming and difficult to scale up for mass production. In this study, we develop a simple solid-state reaction method, in which the carbon-coated SnS2 (SnS2/C) anode materials were synthesized by annealing metallic Sn, sulfur powder, and polyacrylonitrile in a sealed vacuum glass tube. The SnS2/C nanospheres with unique layered structure exhibit a high reversible capacity of 660 mAh g(-1) at a current density of 50 mA g(-1) and maintain at 570 mAh g(-1) for 100 cycles with a degradation rate of 0.14% per cycle, demonstrating one of the best cycling performances in all reported SnS2/C anodes for NIBs to date. The superior cycling stability of SnS2/C electrode is attributed to the stable nanosphere morphology and structural integrity during charge/discharge cycles as evidenced by ex situ characterization.

  17. Electronic Structure and Defect Physics of Tin Sulfides: SnS, Sn2S3 , and Sn S2

    NASA Astrophysics Data System (ADS)

    Kumagai, Yu; Burton, Lee A.; Walsh, Aron; Oba, Fumiyasu

    2016-07-01

    The tin sulfides SnS, Sn2S3 , and Sn S2 are investigated for a wide variety of applications such as photovoltaics, thermoelectrics, two-dimensional electronic devices, Li ion battery electrodes, and photocatalysts. For these applications, native point defects play important roles, but only those of SnS have been investigated theoretically in the literature. In this study, we consider the band structures, band-edge positions, and thermodynamical stability of the tin sulfides using a density functional that accounts for van der Waals corrections and the G W0 approximation. We revisit the point-defect properties, namely, electronic and atomic structures and energetics of defects, in SnS and newly examine those in Sn S2 and Sn2S3 with a comparison to those in SnS. We find that Sn S2 shows contrasting defect properties to SnS: Undoped SnS shows p -type behavior, whereas Sn S2 shows n type, which are mainly attributed to the tin vacancies and tin interstitials, respectively. We also find that the defect features in Sn2S3 can be described as a combination of those in SnS and Sn S2 , intrinsically Sn2S3 showing n -type behavior. However, the conversion to p type can be attained by doping with a large monovalent cation, namely, potassium. The ambipolar dopability, coupled with the earth abundance of its constituents, indicates great potential for electronic applications, including photovoltaics.

  18. Nanostructured SnS with inherent anisotropic optical properties for high photoactivity

    NASA Astrophysics Data System (ADS)

    Patel, Malkeshkumar; Chavda, Arvind; Mukhopadhyay, Indrajit; Kim, Joondong; Ray, Abhijit

    2016-01-01

    In view of the worldwide energy challenge in the 21st century, the technology of semiconductor-based photoelectrochemical (PEC) water splitting has received considerable attention as an alternative approach for solar energy harvesting and storage. Two-dimensional (2D) structures such as nanosheets have the potential to tap the solar energy by unlocking the functional properties at the nanoscale. Tin(ii) sulfide is a fascinating solar energy material due to its anisotropic material properties. In this manuscript, we report on exploiting the 2D structure modulated optical properties of nanocrystalline SnS thin film synthesized by chemical spray pyrolysis using ambient transport in the harvesting of solar energy. We obtained the nanostructured SnS with well-preserved dimensions and morphologies with one step processing. The work demonstrates that the intrinsically ordered SnS nanostructure on FTO coated glass can tap the incident radiation in an efficient manner. The structure-property relationship to explain the photo-response in nanocrystalline-SnS is verified experimentally and theoretically. The novel design scheme for antireflection coating along with the anisotropic properties of SnS is conceived for realizing a PEC cell. The developed PEC cell consists of a SnS photoanode which shows considerably high photocurrent density of 7 mA cm-2 with aqueous media under AM 1.5G, 100 mW cm-2 exposure with notably stable operation. Electrochemical impedance spectroscopy revealed that a non-ideal capacitive behavior as well as drift assisted transport across the solid-state interface is responsible for such a high photo-current density in the nanocrystalline-SnS photoanode.In view of the worldwide energy challenge in the 21st century, the technology of semiconductor-based photoelectrochemical (PEC) water splitting has received considerable attention as an alternative approach for solar energy harvesting and storage. Two-dimensional (2D) structures such as nanosheets have the

  19. Making Record-efficiency SnS Solar Cells by Thermal Evaporation and Atomic Layer Deposition.

    PubMed

    Jaramillo, Rafael; Steinmann, Vera; Yang, Chuanxi; Hartman, Katy; Chakraborty, Rupak; Poindexter, Jeremy R; Castillo, Mariela Lizet; Gordon, Roy; Buonassisi, Tonio

    2015-05-22

    Tin sulfide (SnS) is a candidate absorber material for Earth-abundant, non-toxic solar cells. SnS offers easy phase control and rapid growth by congruent thermal evaporation, and it absorbs visible light strongly. However, for a long time the record power conversion efficiency of SnS solar cells remained below 2%. Recently we demonstrated new certified record efficiencies of 4.36% using SnS deposited by atomic layer deposition, and 3.88% using thermal evaporation. Here the fabrication procedure for these record solar cells is described, and the statistical distribution of the fabrication process is reported. The standard deviation of efficiency measured on a single substrate is typically over 0.5%. All steps including substrate selection and cleaning, Mo sputtering for the rear contact (cathode), SnS deposition, annealing, surface passivation, Zn(O,S) buffer layer selection and deposition, transparent conductor (anode) deposition, and metallization are described. On each substrate we fabricate 11 individual devices, each with active area 0.25 cm(2). Further, a system for high throughput measurements of current-voltage curves under simulated solar light, and external quantum efficiency measurement with variable light bias is described. With this system we are able to measure full data sets on all 11 devices in an automated manner and in minimal time. These results illustrate the value of studying large sample sets, rather than focusing narrowly on the highest performing devices. Large data sets help us to distinguish and remedy individual loss mechanisms affecting our devices.

  20. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2011-01-01

    This column features summaries of five research articles relevant to school crisis response. The first, "High School Teachers' Experiences With Suicidal Students," summarized by Robyn Bratica, offers the results of a study examining high school teachers' experiences with suicidal students and suggests that contact with suicidal students is very…

  1. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2012-01-01

    In this column, members of the NASP Crisis Management in the Schools Interest Group provide summaries of three studies relevant to school crisis response. The first study investigated the prevalence of posttraumatic stress disorder (PTSD) among rescue workers. The second article explored the Child and Family Traumatic Stress Intervention, which is…

  2. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2009-01-01

    This article presents summaries of three recent crisis management publications: (1) "School Violence: Associations With Control, Security/Enforcement, Educational/Therapeutic Approaches, and Demographic Factors," reviewed by Ashlee Barton; (2) "The Relationship Between Cognitive Coping Styles and PTSD in Survivors of Traffic Accidents," summarized…

  3. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2009-01-01

    This article presents summaries of four recent crisis management publications: (1) "Crisis Intervention for Children/Caregivers Exposed to Intimate Partner Violence," summarized by Donna DeVaughn Kreskey; (2) "Predictors of Trauma Reactions Following the 9/11 Terrorist Attacks," summarized by Kelly O'Connor; (3) "Cognitive Coping Styles and PTSD…

  4. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2009-01-01

    This article presents summaries of three recent crisis management publications: (1) "The Impact of School Violence on School Personnel," summarized by Kimberly de Deaux; (2) "Children Exposed to War/Terrorism," summarized by Jennifer DeFago; and (3) "Suicide Survivors Seeking Mental Health Services," summarized by Kimberly de Deaux. The first…

  5. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2010-01-01

    This column features summaries of research articles from 3 recent crisis management publications. The first, "School Shootings and Counselor Leadership: Four Lessons from the Field" summarized by Kristi Fenning, was conducted as the result of the increased demand for trained crisis personnel on school campuses. Survey participants were…

  6. Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.

    2009-01-01

    This article presents summaries of two recent crisis management publications: (1) "Social Validity of the CISM Model for School Crisis Intervention," summarized by Jack R. Dempsey; and (2) "School Violence: Associations With Control, Security/Enforcement, Educational/Therapeutic Approaches, and Demographic Factors," summarized by Ashlee Barton.…

  7. Combinatorial development of Cu2SnS3 as an earth abundant photovoltaic absorber

    NASA Astrophysics Data System (ADS)

    Baranowski, Lauryn L.

    The development of high efficiency, earth abundant photovoltaic absorbers is critical if photovoltaics are to be implemented on the TW scale. Although traditional thin films absorbers such as Cu(In,Ga)Se2 and CdTe have achieved over 20% device efficiencies, the ultimately scalability of these devices may be limited by elemental scarcity and toxicity issues. To date, the most successful earth abundant thin film absorber is Cu2ZnSn(S,Se) 4, which has achieved 12.6% efficiency as of 2014. However, chemical complexity and disorder issues with this material have made the path to higher efficiency CZTSSe devices unclear. As a result, many researchers are now exploring alternative earth abundant absorber materials. In this thesis, we apply our "rapid development" methodology to the exploration of alternative photovoltaic absorbers. The rapid development (RD) methodology, consisting of exploration, research, and development stages, uses complementary theory and experiment to assess candidate materials and down-select in each stage. The overall result is that, in the time span of ~2-3 years, we are able to rapidly go from tens of possible absorber materials to 1-2 working PV device prototypes. Here, we demonstrate the RD approach as applied to the Cu-Sn-S system. We begin our investigation of the Cu-Sn-S system by evaluating the thermodynamic stability, electrical transport, electronic structure, and optical and defect properties of candidate materials using complementary theory and experiment. We find that Cu2SnS3 is the most promising absorber candidate because of its strong optical absorption, tunable doping, and wide stability range. Our other candidate compounds suffer from serious flaws that preclude them from being successful photovoltaic absorbers, including too high experimental conductivity (Cu4SnS4), or poor hole transport and low absorption coefficient (Cu4Sn7S16). Next, we investigate the doping and defect physics of Cu2SnS 3. We identify the origins of the

  8. Synthesis of tin monosulfide (SnS) nanoparticles using surfactant free microemulsion (SFME) with the single microemulsion scheme

    NASA Astrophysics Data System (ADS)

    Tarkas, Hemant S.; Marathe, Deepak M.; Mahajan, Mrunal S.; Muntaser, Faisal; Patil, Mahendra B.; Tak, Swapnil R.; Sali, Jaydeep V.

    2017-02-01

    Synthesis of monomorphic, SnS nanoparticles without using a capping agent is a difficult task with chemical route of synthesis. This paper reports on synthesis of tin monosulfide (SnS) nanopartilces with dimension in the quantum-dot regime using surfactant free microemulsion with single microemulsion scheme. This has been achieved by reaction in microreactors in the CME (C: chlorobenzene, M: methanol and E: ethylene glycol) microemulsion system. This is an easy and controllable chemical route for synthesis of SnS nanoparticles. Nanoparticle diameter showed prominent dependence on microemulsion concentration and marginal dependence on microemulsion temperature in the temperature range studied. The SnS nanoparticles formed with this method form stable dispersion in Tolune.

  9. SnS Thin Films Prepared by Chemical Spray Pyrolysis at Different Substrate Temperatures for Photovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Sall, Thierno; Soucase, Bernabé Marí; Mollar, Miguel; Sans, Juan Angel

    2017-03-01

    The preparation and analysis of morphological, structural, optical, vibrational and compositional properties of tin monosulfide (SnS) thin films deposited on glass substrate by chemical spray pyrolysis is reported herein. The growth conditions were evaluated to reduce the presence of residual phases different to the SnS orthorhombic phase. X-ray diffraction spectra revealed the polycrystalline nature of the SnS films with orthorhombic structure and a preferential grain orientation along the (111) direction. At high substrate temperature (450°C), a crystalline phase corresponding to the Sn2S3 phase was observed. Raman spectroscopy confirmed the dominance of the SnS phase and the presence of an additional Sn2S3 phase. Scanning electron microscopy (SEM) images reveal that the SnS film morphology depends on the substrate temperature. Between 250°C and 350°C, SnS films were shaped as rounded grains with some cracks between them, while at substrate temperatures above 400°C, films were denser and more compact. Energy-dispersive x-ray spectroscopy (EDS) analysis showed that the stoichiometry of sprayed SnS films improved with the increase of substrate temperature and atomic force microscopy micrographs showed films well covered at 350°C resulting in a rougher and bigger grain size. Optical and electrical measurements showed that the optical bandgap and the resistivity decreased when the substrate temperature increased, and smaller values, 1.46 eV and 60 Ω cm, respectively, were attained at 450°C. These SnS thin films could be used as an absorber layer for the development of tandem solar cell devices due to their high absorbability in the visible region with optimum bandgap energy.

  10. SnS Thin Films Prepared by Chemical Spray Pyrolysis at Different Substrate Temperatures for Photovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Sall, Thierno; Soucase, Bernabé Marí; Mollar, Miguel; Sans, Juan Angel

    2017-01-01

    The preparation and analysis of morphological, structural, optical, vibrational and compositional properties of tin monosulfide (SnS) thin films deposited on glass substrate by chemical spray pyrolysis is reported herein. The growth conditions were evaluated to reduce the presence of residual phases different to the SnS orthorhombic phase. X-ray diffraction spectra revealed the polycrystalline nature of the SnS films with orthorhombic structure and a preferential grain orientation along the (111) direction. At high substrate temperature (450°C), a crystalline phase corresponding to the Sn2S3 phase was observed. Raman spectroscopy confirmed the dominance of the SnS phase and the presence of an additional Sn2S3 phase. Scanning electron microscopy (SEM) images reveal that the SnS film morphology depends on the substrate temperature. Between 250°C and 350°C, SnS films were shaped as rounded grains with some cracks between them, while at substrate temperatures above 400°C, films were denser and more compact. Energy-dispersive x-ray spectroscopy (EDS) analysis showed that the stoichiometry of sprayed SnS films improved with the increase of substrate temperature and atomic force microscopy micrographs showed films well covered at 350°C resulting in a rougher and bigger grain size. Optical and electrical measurements showed that the optical bandgap and the resistivity decreased when the substrate temperature increased, and smaller values, 1.46 eV and 60 Ω cm, respectively, were attained at 450°C. These SnS thin films could be used as an absorber layer for the development of tandem solar cell devices due to their high absorbability in the visible region with optimum bandgap energy.

  11. Low-Temperature Electrical Characteristics of Si-Based Device with New Tetrakis NiPc-SNS Active Layer

    NASA Astrophysics Data System (ADS)

    Yavuz, Arzu Büyükyağci; Carbas, Buket Bezgın; Sönmezoğlu, Savaş; Soylu, Murat

    2016-01-01

    A new tetrakis 4-(2,5-di-2-thiophen-2-yl-pyrrol-1-yl)-substituted nickel phthalocyanine (NiPc-SNS) has been synthesized. This synthesized NiPc-SNS thin film was deposited on p-type Si substrate using the spin coating method (SCM) to fabricate a NiPc-SNS/ p-Si heterojunction diode. The temperature-dependent electrical characteristics of the NiPc-SNS/ p-Si heterojunction with good rectifying behavior were investigated by current-voltage ( I- V) measurements between 50 K and 300 K. The results indicate that the ideality factor decreases while the barrier height increases with increasing temperature. The barrier inhomogeneity across the NiPc-SNS/ p-Si heterojunction reveals a Gaussian distribution at low temperatures. These results provide further evidence of the more complicated mechanisms occurring in this heterojunction. Based on these findings, NiPc-SNS/ p-Si junction diodes are feasible for use in low-temperature applications.

  12. Experimental Plasma Research project summaries

    SciTech Connect

    1980-09-01

    This report contains descriptions of the activities supported by the Experimental Plasma Research Branch of APP. The individual project summaries were prepared by the principal investigators and include objectives and milestones for each project. The projects are arranged in six research categories: Plasma Properties; Plasma Heating; Plasma Diagnostics; Atomic, Molecular and Nuclear Physics; Advanced Superconducting Materials; and the Fusion Plasma Research Facility (FPRF). Each category is introduced with a statement of objectives and recent progress and followed by descriptions of individual projects. An overall budget summary is provided at the beginning of the report.

  13. DESIGN AND DEVELOPMENT OF THE SNS RING VACUUM INSTRUMENTATION AND CONTROL SYSTEMS.

    SciTech Connect

    HSEUH,H.C.; SMART,L.A.; TANG,J.Y.

    2001-06-18

    BNL is undertaking the design, construction and commissioning of the Spallation Neutron Source (SNS) accumulator ring and the beam transport lines [l]. Ultrahigh vacuum of 10{sup {minus}9} Torr is required in the accumulator ring to minimize beam-gas ionization, a contributing factor to the e-p instability observed in a few high-intensity proton storage rings. All vacuum instrumentation must be capable of local and remote operation to achieve a reliable vacuum system, especially in this extremely high intensity accelerator. The design and development of the SNS ring vacuum instrumentation and control through the Experimental Physics and Industrial Control System (EPICS) distributed real-time software tools are presented.

  14. (abstract) All Epitaxial Edge-geometry SNS Devices with Doped PBCO and YBCO Normal Layers

    NASA Technical Reports Server (NTRS)

    Barner, J. B.; Hunt, B. D.; Foote, M. C.

    1995-01-01

    We will present our results on tapered-edge-geometry SNS weak link fabricated from c-axis oriented base-, counterelectrode and normal layers using a variety of processing conditions. To date, we have employed a variety of different normal materials (Co-doped YBCO, Y-doped PBCO, Ca-doped PBCO). We have been examining the junction fabrication process in detail and we will present our methods. In particular, we have been examining both epitaxial and non-epitaxial milling mask overlayers and we will present a comparison of both methods. These devices behave similar to the expectations of the resisively shunted junction model and conventional SNS proximity effect models but with some differences which will be discussed. We will present the detailed systematics of our junctions including device parameters versus temperature, rf and dc magnetic response for the various processing conditions.

  15. Design, construction, and initial operation of the SNS MEBT chopper system

    SciTech Connect

    Hardekopf, R. A.

    2004-01-01

    The chopper system for the Spallation Neutron Source (SNS) provides a gap in the beans for clean extraction from the accumulator ring. It consists of a pre-chopper in the low-energy bean transport (LEBT) and a faster chopper in the medium-energy beam transport (MEBT). We report here on the final design, fabrication, installation, and first beans tests of the MEBT chopper. The traveling-wave deflector is a meander-line design that matches the propagation of the deflecting pulse with the velocity of the beam at 2.5 MeV, after the radio-frequency quadrupole (RFQ) acceleration stage. The pulses uses a series of fast-risetime MOSFET transistors to generate the deflecting pulses of +- 2.5 kV with rise and fall times of 10 ns. We describe the design and fabrication of the meander line and pulsers and report on the first operation during initial beam tests at SNS.

  16. Plasma ignition schemes for the SNS radio-frequency driven H- source

    SciTech Connect

    Schenkel, T.; Staples, J.W.; Thomae, W.; Reijonen, J.; Gough, R.A.; Leung, K.N.; Keller, R.

    2001-09-06

    The H{sup -} ion source for the Spallation Neutron Source (SNS) is a cesiated, radio-frequency driven (2 MHz) multicusp volume source which operates at a duty cycle of 6% (1 ms pulses and 60 Hz). In pulsed RF driven plasma sources, ignition of the plasma affects the stability of source operation and the antenna lifetime. We are reporting on investigations of different ignition schemes, based on secondary electron generation in the plasma chamber by UV light, a hot filament, a low power RF plasma (cw, 13.56 MHz), as well as source operation solely with the high power (40 kW) 2 MHz RF. We find that the dual frequency, single antenna scheme is most attractive for the operating conditions of the SNS H{sup -} source.

  17. Computational Fluid Dynamics in Support of the SNS Liquid Mercury Thermal-Hydraulic Analysis

    SciTech Connect

    Siman-Tov, M.; Wendel, M.W.; Yoder, G.L.

    1999-11-14

    Experimental and computational thermal-hydraulic research is underway to support the liquid mercury target design for the Spallation Neutron Source (SNS) facility. The SNS target will be subjected to internal nuclear heat generation that results from pulsed proton beam collisions with the mercury nuclei. Recirculation and stagnation zones within the target are of particular concern because of the likelihood that they will result in local hot spots and diminished heat removal from the target structure. Computational fluid dynamics (CFD) models are being used as a part of this research. Recent improvements to the 3D target model include the addition of the flow adapter which joins the inlet/outlet coolant pipes to the target body and an updated heat load distribution at the new baseline proton beam power level of 2 MW. Two thermal-hydraulic experiments are planned to validate the CFD model.

  18. Edge effects in the magnetic interference pattern of a ballistic SNS junction

    NASA Astrophysics Data System (ADS)

    Meier, Hendrik; Fal'ko, Vladimir I.; Glazman, Leonid I.

    2016-05-01

    We investigate the Josephson critical current Ic(Φ ) of a wide superconductor-normal metal-superconductor (SNS) junction as a function of the magnetic flux Φ threading it. Electronic trajectories reflected from the side edges alter the function Ic(Φ ) as compared to the conventional Fraunhofer-type dependence. At weak magnetic fields, B ≲Φ0/d2 , the edge effect lifts zeros in Ic(Φ ) and gradually shifts the minima of that function toward half-integer multiples of the flux quantum. At B >Φ0/d2 , the edge effect leads to an accelerated decay of the critical current Ic(Φ ) with increasing Φ . At larger fields, eventually, the system is expected to cross into a regime of "classical" mesoscopic fluctuations that is specific for wide ballistic SNS junctions with rough edges.

  19. N-type conduction in SnS by anion substitution with Cl

    NASA Astrophysics Data System (ADS)

    Yanagi, Hiroshi; Iguchi, Yuki; Sugiyama, Taiki; Kamiya, Toshio; Hosono, Hideo

    2016-05-01

    Relatively nontoxic, earth-abundant Cl was incorporated into n-type SnS as a dopant. The existence of impurity phases was carefully identified in Sn(S1- x - y Cl x )-dense ceramics. The highest electron mobility (8.3 cm2 V-1 s-1) in n-type conduction was achieved in samples with x ≥ 0.005. Cl concentration is critical for conduction-type conversion, whereas carrier density and electron mobility are determined by sulfur-site deficiency. Carrier transport is explained by grain boundary potential barrier scattering in undoped p-type samples and by ionized impurity scattering in Cl-doped n-type samples.

  20. CONSTRUCTION AND POWER TEST OF THE EXTRACTION KICKER MAGNET FOR SNS ACCUMULATOR RING.

    SciTech Connect

    PAI, C.; HAHN, H.; HSEUH, H.; LEE, Y.; MENG, W.; MI,J.; SANDBERG, J.; TODD, R.; ET AL.

    2005-05-16

    Two extraction kicker magnet assemblies that contain seven individual pulsed magnet modules each will kick the proton beam vertically out of the SNS accumulator ring into the aperture of the extraction Lambertson septum magnet. The proton beam then travels to the 1.4 MW SNS target assembly. The 14 kicker magnets and major components of the kicker assembly have been fabricated in BNL. The inner surfaces of the kicker magnets were coated with TiN to reduce the secondary electron yield. All 14 PFN power supplies have been built, tested and delivered to OWL. Before final installation, a partial assembly of the kicker system with three kicker magnets was assembled to test the functions of each critical component in the system. In this paper we report the progress of the construction of the kicker components, the TIN coating of the magnets, the installation procedure of the magnets and the full power test of the kicker with the PFN power supply.

  1. Fast Monte Carlo simulation of a dispersive sample on the SEQUOIA spectrometer at the SNS

    SciTech Connect

    Granroth, Garrett E; Chen, Meili; Kohl, James Arthur; Hagen, Mark E; Cobb, John W

    2007-01-01

    Simulation of an inelastic scattering experiment, with a sample and a large pixilated detector, usually requires days of time because of finite processor speeds. We report simulations on an SNS (Spallation Neutron Source) instrument, SEQUOIA, that reduce the time to less than 2 hours by using parallelization and the resources of the TeraGrid. SEQUOIA is a fine resolution (∆E/Ei ~ 1%) chopper spectrometer under construction at the SNS. It utilizes incident energies from Ei = 20 meV to 2 eV and will have ~ 144,000 detector pixels covering 1.6 Sr of solid angle. The full spectrometer, including a 1-D dispersive sample, has been simulated using the Monte Carlo package McStas. This paper summarizes the method of parallelization for and results from these simulations. In addition, limitations of and proposed improvements to current analysis software will be discussed.

  2. Background Neutron Studies for Coherent Elastic Neutrino-Nucleus Scattering Measurements at the SNS

    NASA Astrophysics Data System (ADS)

    Markoff, Diane; Coherent Collaboration

    2015-10-01

    The COHERENT collaboration has proposed to measure coherent, elastic neutrino-nucleus scattering (CE νNS) cross sections on several nuclear targets using neutrinos produced at the Spallation Neutron Source (SNS) located at the Oak Ridge National Laboratory. The largest background of concern arises from beam-induced, fast neutrons that can mimic a nuclear recoil signal event in the detector. Multiple technologies of neutron detection have been employed at prospective experiment sites at the SNS. Analysis of these data have produced a consistent picture of the backgrounds expected for a CE νNS measurement. These background studies show that at suitable locations, the fast neutrons of concern arrive mainly in the prompt 1.3 μs window and the neutrons in the delayed window are primarily of lower energies that are relatively easier to shield.

  3. Achieving optimum carrier concentrations in p-doped SnS thermoelectrics.

    PubMed

    Bhattacharya, Sandip; Gunda, N S Harsha; Stern, Robin; Jacobs, Stéphane; Chmielowski, Radoslaw; Dennler, Gilles; Madsen, Georg K H

    2015-04-14

    Tin(II)sulfide, SnS, is a commercially viable and environmentally friendly thermoelectric material. Recently it was shown how the carrier concentration and the thermoelectric power factor can be optimized by Ag-doping in a sulphur rich environment. Theoretical calculations lead to a fairly accurate estimation of the carrier concentration, whereas the potential of doping with Li(+) is strongly overestimated. Two principally ubiquitous effects that can result in decreasing the hole concentration, namely the formation of coupled defect complexes and oxidation of the dopant, are discussed as possible origins of this disagreement. It is shown that oxidation limits the chemical potential of Li beyond that already set by the formation of Li2S. This work serves as a comprehensive guide to achieve an efficient p-doped SnS thermoelectric material.

  4. Development of a fast traveling-wave beam chopper for the SNS project

    SciTech Connect

    Kurennoy, S.S.; Power, J.F.

    1998-12-31

    High current and stringent restrictions on beam losses, below 1 nA/m, in the designed linac for the Spallation Neutron Source (SNS) require clean and fast--with the rise time from 2% to 98% less than 2.5 ns--beam chopping in its front end, at the beam energy 2.5 MeV. The development of new traveling-wave deflecting current structures based on meander lines is discussed. Three-dimensional time-domain computer simulations with MAFIA are used to study transient effects in the chopper and to optimize current structure design. Two options for the fast pulsed voltage generator--based on FETs and vacuum tubes--are considered, and their advantages and shortcomings for the SNS chopper are discussed.

  5. A novel theory on the origin of the genetic code: a GNC-SNS hypothesis.

    PubMed

    Ikehara, Kenji; Omori, Yoko; Arai, Rieko; Hirose, Akiko

    2002-04-01

    We have previously proposed an SNS hypothesis on the origin of the genetic code (Ikehara and Yoshida 1998). The hypothesis predicts that the universal genetic code originated from the SNS code composed of 16 codons and 10 amino acids (S and N mean G or C and either of four bases, respectively). But, it must have been very difficult to create the SNS code at one stroke in the beginning. Therefore, we searched for a simpler code than the SNS code, which could still encode water-soluble globular proteins with appropriate three-dimensional structures at a high probability using four conditions for globular protein formation (hydropathy, alpha-helix, beta-sheet, and beta-turn formations). Four amino acids (Gly [G], Ala [A], Asp [D], and Val [V]) encoded by the GNC code satisfied the four structural conditions well, but other codes in rows and columns in the universal genetic code table do not, except for the GNG code, a slightly modified form of the GNC code. Three three-amino acid systems ([D], Leu and Tyr; [D], Tyr and Met; Glu, Pro and Ile) also satisfied the above four conditions. But, some amino acids in the three systems are far more complex than those encoded by the GNC code. In addition, the amino acids in the three-amino acid systems are scattered in the universal genetic code table. Thus, we concluded that the universal genetic code originated not from a three-amino acid system but from a four-amino acid system, the GNC code encoding [GADV]-proteins, as the most primitive genetic code.

  6. (abstract) Epitaxial High-T(sub c) SNS Weak Links on Silicon-on-Sapphire Substrates

    NASA Technical Reports Server (NTRS)

    Hunt, B. D.; Barner, J. B.; Foote, M. C.; Vasquez, R. P.; Schoelkopf, R. J.; Phillips, T. G.; Zmuidzinas, J.

    1994-01-01

    High-T(sub c) SNS weak links are expected to prove useful as high frequency sources and detectors. Recent studies with low-T(sub c) Josephson mixers using shunted tunnel junctions at 100 GHz show good initial performance, and modeling suggests that these results should extrapolate to higher frequencies if larger I(sub c)R(sub n) products can be achieved. Progress on this work will be reported.

  7. Electron-cloud updated simulation results for the PSR, and recent results for the SNS

    SciTech Connect

    Pivi, M.; Furman, M.A.

    2002-05-29

    Recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source (SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR) at Los Alamos are presented in this paper. A refined model for the secondary emission process including the so called true secondary, rediffused and backscattered electrons has recently been included in the electron-cloud code.

  8. BEAM STOP DESIGN METHODOLOGY AND DESCRIPTION OF A NEW SNS BEAM STOP

    SciTech Connect

    Polsky, Yarom; Plum, Michael A; Geoghegan, Patrick J; Jacobs, Lorelei L; Lu, Wei; McTeer, Stephen Mark

    2010-01-01

    The design of accelerator components such as magnets, accelerator cavities and beam instruments tends to be a fairly standardized and collective effort within the particle accelerator community with well established performance, reliability and, in some cases, even budgetary criteria. Beam stop design, by contrast, has been comparatively subjective historically with much more general goals. This lack of rigor has lead to a variety of facility implementations with limited standardization and minimal consensus on approach to development within the particle accelerator community. At the Spallation Neutron Source (SNS), for example, there are four high power beam stops in use, three of which have significantly different design solutions. This paper describes the design of a new off-momentum beam stop for the SNS. The technical description of the system will be complemented by a discussion of design methodology. This paper presented an overview of the new SNS HEBT off-momentum beam stop and outlined a methodology for beam stop system design. The new beam stop consists of aluminium and steel blocks cooled by a closed-loop forced-air system and is expected to be commissioned this summer. The design methodology outlined in the paper represents a basic description of the process, data, analyses and critical decisions involved in the development of a beam stop system.

  9. RF Conditioning and Testing of Fundamental Power Couplers for SNS Superconducting Cavity Production

    SciTech Connect

    M. Stirbet; G.K. Davis; M. A. Drury; C. Grenoble; J. Henry; G. Myneni; T. Powers; K. Wilson; M. Wiseman; I.E. Campisi; Y.W. Kang; D. Stout

    2005-05-16

    The Spallation Neutron Source (SNS) makes use of 33 medium beta (0.61) and 48 high beta (0.81) superconducting cavities. Each cavity is equipped with a fundamental power coupler, which should withstand the full klystron power of 550 kW in full reflection for the duration of an RF pulse of 1.3 msec at 60 Hz repetition rate. Before assembly to a superconducting cavity, the vacuum components of the coupler are submitted to acceptance procedures consisting of preliminary quality assessments, cleaning and clean room assembly, vacuum leak checks and baking under vacuum, followed by conditioning and RF high power testing. Similar acceptance procedures (except clean room assembly and baking) were applied for the airside components of the coupler. All 81 fundamental power couplers for SNS superconducting cavity production have been RF power tested at JLAB Newport News and, beginning in April 2004 at SNS Oak Ridge. This paper gives details of coupler processing and RF high power-assessed performances.

  10. Recent Advances in the Performance and Understanding of the SNS Ion Source

    NASA Astrophysics Data System (ADS)

    Welton, R. F.; Stockli, M. P.; Murray, S. N.; Keller, R.

    2005-04-01

    The ion source developed for the Spallation Neutron Source (SNS) by Lawrence Berkeley National Laboratory (LBNL), is a radio frequency, multi-cusp source designed to produce ˜ 40 mA of H- with a normalized rms emittance of less than 0.2 pi mm mrad. To date, the source has been utilized in the commissioning of the SNS accelerator and has already demonstrated stable, satisfactory operation at beam currents of ˜30 mA with duty-factors of ˜0.1% for operational periods of several weeks. Once the SNS is fully operational in 2008, a beam current duty-factor of 6% (1 ms pulse length, 60 Hz repetition rate) will be required in order to inject the accelerator. To ascertain the capability of the source to deliver beams at this high duty-factor over sustained time periods, several experimental runs have been conducted, each ˜1 week in length, in which the ion source was continuously operated on a dedicated test stand. The results of these tests are reported as well as a theory of the Cs release and transport processes which were derived from these data. The theory was then employed to develop a more effective source conditioning procedure as well as an improved Cs collar design. Initial results of tests employing a Cs collar with enhanced surface ionization geometry are also discussed.

  11. Energetic alignment in nontoxic SnS quantum dot-sensitized solar cell employing spiro-OMeTAD as the solid-state electrolyte.

    PubMed

    Oda, Yoshiaki; Shen, Heping; Zhao, Lin; Li, Jianbao; Iwamoto, Mitsumasa; Lin, Hong

    2014-06-01

    An environmentally friendly solid-state quantum dot sensitized solar cell (ss-QDSSC) was prepared by combining colloidal SnS QDs as the sensitizer and organic hole scavenger spiro-OMeTAD (2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)9,9'-spirobifluorene) as the solid-state electrolyte, and the energy alignment of SnS and TiO2 was investigated. The bandgap of colloidal SnS QDs increased with decreasing particle size from 14 to 4 nm due to an upshift of the conduction band and a downshift of the valence band. In TiO2/SnS heterojunctions, the conduction band minimum (CBM) difference between TiO2 and SnS was as large as ∼0.8 eV; this difference decreased with decreasing particle size, but was sufficient for electron injection from SnS nanoparticles of any size into TiO2. Meanwhile, the sensitizer regeneration driving force, that is, the difference between the valence band maximum (VBM) of SnS and the work function of the electrolyte, showed an opposite behaviour with the SnS size due to a downward shift of the SnS VB. Consequently, smaller SnS QDs should result in a more efficient charge transfer in heterojunctions, revealing the advantages of QDs vs larger particles as sensitizers. This prediction was confirmed by the improved photovoltaic performance of ss-QDSSCs modified with SnS nanoparticles, which peaked for 5-6 nm sized SnS nanoparticles due to the balance between electron injection and sunlight absorption.

  12. Energetic alignment in nontoxic SnS quantum dot-sensitized solar cell employing spiro-OMeTAD as the solid-state electrolyte

    PubMed Central

    Oda, Yoshiaki; Shen, Heping; Zhao, Lin; Li, Jianbao; Iwamoto, Mitsumasa; Lin, Hong

    2014-01-01

    An environmentally friendly solid-state quantum dot sensitized solar cell (ss-QDSSC) was prepared by combining colloidal SnS QDs as the sensitizer and organic hole scavenger spiro-OMeTAD (2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)9,9′-spirobifluorene) as the solid-state electrolyte, and the energy alignment of SnS and TiO2 was investigated. The bandgap of colloidal SnS QDs increased with decreasing particle size from 14 to 4 nm due to an upshift of the conduction band and a downshift of the valence band. In TiO2/SnS heterojunctions, the conduction band minimum (CBM) difference between TiO2 and SnS was as large as ∼0.8 eV; this difference decreased with decreasing particle size, but was sufficient for electron injection from SnS nanoparticles of any size into TiO2. Meanwhile, the sensitizer regeneration driving force, that is, the difference between the valence band maximum (VBM) of SnS and the work function of the electrolyte, showed an opposite behaviour with the SnS size due to a downward shift of the SnS VB. Consequently, smaller SnS QDs should result in a more efficient charge transfer in heterojunctions, revealing the advantages of QDs vs larger particles as sensitizers. This prediction was confirmed by the improved photovoltaic performance of ss-QDSSCs modified with SnS nanoparticles, which peaked for 5–6 nm sized SnS nanoparticles due to the balance between electron injection and sunlight absorption. PMID:27877682

  13. Executive summary

    NASA Technical Reports Server (NTRS)

    Ayon, Juan A.

    1992-01-01

    The Astrotech 21 Optical Systems Technology Workshop was held in Pasadena, California on March 6-8, 1991. The purpose of the workshop was to examine the state of Optical Systems Technology at the National Aeronautics Space Administration (NASA), and in industry and academia, in view of the potential Astrophysics mission set currently being considered for the late 1990's through the first quarter of the 21st century. The principal result of the workshop is this publication, which contains an assessment of the current state of the technology, and specific technology advances in six critical areas of optics, all necessary for the mission set. The workshop was divided into six panels, each of about a dozen experts in specific fields, representing NASA, industry, and academia. In addition, each panel contained expertise that spanned the spectrum from x-ray to submillimeter wavelengths. This executive summary contains the principal recommendations of each panel. The six technology panels and their chairs were: (1) Wavefront Sensing, Control, and Pointing, Thomas Pitts, Itek Optical Systems, A Division of Litton; (2) Fabrication, Roger Angel, Steward Observatory, University of Arizona; (3) Materials and Structures, Theodore Saito, Lawrence Livermore National Laboratory; (4) Optical Testing, James Wyant, WYKO Corporation; (5) Optical Systems Integrated Modeling, Robert R. Shannon, Optical Sciences Center, University of Arizona; and (6) Advanced Optical Instruments Technology, Michael Shao, Jet Propulsion Laboratory, California Institute of Technology. This Executive Summary contains the principal recommendations of each panel.

  14. Numerical modeling of the SNS H{sup −} ion source

    SciTech Connect

    Veitzer, Seth A.; Beckwith, Kristian R. C.; Kundrapu, Madhusudhan; Stoltz, Peter H.

    2015-04-08

    Ion source rf antennas that produce H- ions can fail when plasma heating causes ablation of the insulating coating due to small structural defects such as cracks. Reducing antenna failures that reduce the operating capabilities of the Spallation Neutron Source (SNS) accelerator is one of the top priorities of the SNS H- Source Program at ORNL. Numerical modeling of ion sources can provide techniques for optimizing design in order to reduce antenna failures. There are a number of difficulties in developing accurate models of rf inductive plasmas. First, a large range of spatial and temporal scales must be resolved in order to accurately capture the physics of plasma motion, including the Debye length, rf frequencies on the order of tens of MHz, simulation time scales of many hundreds of rf periods, large device sizes on tens of cm, and ion motions that are thousands of times slower than electrons. This results in large simulation domains with many computational cells for solving plasma and electromagnetic equations, short time steps, and long-duration simulations. In order to reduce the computational requirements, one can develop implicit models for both fields and particle motions (e.g. divergence-preserving ADI methods), various electrostatic models, or magnetohydrodynamic models. We have performed simulations using all three of these methods and have found that fluid models have the greatest potential for giving accurate solutions while still being fast enough to perform long timescale simulations in a reasonable amount of time. We have implemented a number of fluid models with electromagnetics using the simulation tool USim and applied them to modeling the SNS H- ion source. We found that a reduced, single-fluid MHD model with an imposed magnetic field due to the rf antenna current and the confining multi-cusp field generated increased bulk plasma velocities of > 200 m/s in the region of the antenna where ablation is often observed in the SNS source. We report

  15. Effect of post-deposition annealing on the growth and properties of cubic SnS films

    NASA Astrophysics Data System (ADS)

    Chalapathi, U.; Poornaprakash, B.; Park, Si-Hyun

    2017-03-01

    We report a detailed investigation of the effect of post-deposition annealing on the growth and physical properties of chemically grown cubic SnS films. Chemically deposited cubic SnS films were subjected to annealing in a graphite box with loaded elemental sulfur under N2 at 150-350 °C for 10, 30, and 60 min in order to understand the grain growth and morphology of the films. Films annealed at 150-250 °C for 10 min showed improved grain size and a more uniform grain morphology. Films annealed at 150-250 °C for 30 and 60 min showed a decrease in the grain size and non-uniform grain morphology for the cubic SnS phase. Films annealed at 300 and 350 °C for 10 min revealed the formation of minor secondary phase SnS2, and the grain morphology changed from round shape to flake-like. Longer annealing at 300 and 350 °C improved the extent of the SnS2 phase, and it was found to be the dominant phase after annealing at 350 °C for 60 min. The direct optical band gap of SnS films is 1.75-1.67 eV, depending on the annealing temperature and time. The films exhibited p-type electrical conductivity. The films annealed at 250 °C for 10 min showed a higher hole mobility of 77.7 cm2V-1s-1. Thus, lower annealing temperatures and shorter annealing times are favorable conditions to produce high-quality cubic SnS films.

  16. Integrated diagnostics

    NASA Technical Reports Server (NTRS)

    Hunthausen, Roger J.

    1988-01-01

    Recently completed projects in which advanced diagnostic concepts were explored and/or demonstrated are summarized. The projects begin with the design of integrated diagnostics for the Army's new gas turbine engines, and advance to the application of integrated diagnostics to other aircraft subsystems. Finally, a recent project is discussed which ties together subsystem fault monitoring and diagnostics with a more complete picture of flight domain knowledge.

  17. Theoretical perspective on the electronic, magnetic and optical properties of Zn-doped monolayer SnS2

    NASA Astrophysics Data System (ADS)

    Sun, Lili; Zhou, Wei; Liu, Yanyu; Yu, Dandan; Liang, Yinghua; Wu, Ping

    2016-12-01

    The electronic, magnetic and optical properties of Zn-doped monolayer SnS2 have been theoretically investigated with the density functional theory. Numerical results reveal that monolayer SnS2 can be easily synthesized by cleaving its bulk crystal. Besides, the Zn doping in monolayer SnS2 is energetically favored under the S-rich with respect to the Sn-rich condition. The doped system exhibits the magnetic ground states due to the formation of defect states above the Fermi level, which are introduced by the hybridization between S-3p states and a small amount of Sn-4d states. The room temperature ferromagnetism can also be realized in Zn-doped monolayer SnS2. The injection of Zn can enhance the absorption efficiency of solar spectrum, especially in the near-infrared light region. Moreover, the Zn doping can enhance the photocatalytic activity for both the oxygen and hydrogen evolution reactions in the monolayer SnS2.

  18. Effect of ethylene glycol on the growth of hexagonal SnS 2 nanoplates and their optical properties

    NASA Astrophysics Data System (ADS)

    Zhu, Yunqing; Chen, Yiqing; Liu, Lizhu

    2011-08-01

    Hexagonal SnS 2 particles were synthesized via a solvothermal method using a mixture of ethylene glycol (EG) and distilled water as solvent. Hexagonal SnS 2 nanoplates of more regular morphology were obtained when the volumetric ratio of EG to distilled water (EG:H 2O) decreased from 4:1 to 1:4. The effect of EG on the growth of hexagonal SnS 2 nanoplates was investigated and a growth restraint mechanism in [0 0 1] was proposed. A large band gap of 3.52 eV of the hexagonal SnS 2 nanoplates may facilitate electron injection from photo-excited dye molecules in dye-sensitized solar cells (DSSCs). A photoluminescence (PL) peak at 761 nm under excitation at 507 nm was also observed in the hexagonal SnS 2 nanoplates. The 761 nm emission, which is within the absorption band of the Ru-based dye, is expected to make sufficient utilization of solar energy in DSSCs.

  19. Development of companion diagnostics

    SciTech Connect

    Mankoff, David A.; Edmonds, Christine E.; Farwell, Michael D.; Pryma, Daniel A.

    2015-12-12

    The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient’s cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods as companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has “hit” the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2–targeted therapy. Lastly, the review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic.

  20. Development of companion diagnostics

    DOE PAGES

    Mankoff, David A.; Edmonds, Christine E.; Farwell, Michael D.; ...

    2015-12-12

    The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient’s cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods asmore » companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has “hit” the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2–targeted therapy. Lastly, the review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic.« less

  1. Development of Companion Diagnostics.

    PubMed

    Mankoff, David A; Edmonds, Christine E; Farwell, Michael D; Pryma, Daniel A

    2016-01-01

    The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient's cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods as companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has "hit" the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2-targeted therapy. The review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic.

  2. BEAM EXTRACTION FROM THE SNS RING AND DESIGN OF EXTRACTION KICKERS.

    SciTech Connect

    TSOUPAS, N.; BLASKIEWICZ, M.; LEE, Y.Y.; MI, J.L.; SOUKAS, A.; WANG, J.G.; WEI, J.; ZHANG, S.Y.

    2000-06-30

    The accumulator ring of the Spallation Neutron Source (SNS) [1] will accumulate a proton beam, injected from a LINAC, into a single bunch containing {approximately} 2.1 x 10{sup 14} protons at a maximum energy of 1.3 GeV. The single bunch with length {approximately}650 nsec and a gap of {approximately}290 nsec will circulate into the accumulator ring for {approximately}1.0 msec before it is extracted into the RTBT transfer line. The accumulation, extraction frequency is set at 60 Hz. This paper discusses the extraction process and the requirements of the fast beam extraction system.

  3. Laser and optical system for laser assisted hydrogen ion beam stripping at SNS

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Rakhman, A.; Menshov, A.; Webster, A.; Gorlov, T.; Aleksandrov, A.; Cousineau, S.

    2017-03-01

    Recently, a high-efficiency laser assisted hydrogen ion (H-) beam stripping was successfully carried out in the Spallation Neutron Source (SNS) accelerator. The experiment was not only an important step toward foil-less H- stripping for charge exchange injection, it also set up a first example of using megawatt ultraviolet (UV) laser source in an operational high power proton accelerator facility. This paper reports in detail the design, installation, and commissioning result of a macro-pulsed multi-megawatt UV laser system and laser beam transport line for the laser stripping experiment.

  4. SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

    NASA Astrophysics Data System (ADS)

    Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

    2016-05-01

    The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

  5. Effect of thickness on electrical properties of SILAR deposited SnS thin films

    NASA Astrophysics Data System (ADS)

    Akaltun, Yunus; Astam, Aykut; Cerhan, Asena; ćayir, Tuba

    2016-03-01

    Tin sulfide (SnS) thin films of different thickness were prepared on glass substrates by successive ionic layer adsorption and reaction (SILAR) method at room temperature using tin (II) chloride and sodium sulfide aqueous solutions. The thicknesses of the films were determined using spectroscopic ellipsometry measurements and found to be 47.2, 65.8, 111.0, and 128.7nm for 20, 25, 30 and 35 deposition cycles respectively. The electrical properties of the films were investigated using d.c. two-point probe method at room temperature and the results showed that the resistivity was found to decrease with increasing film thickness.

  6. A Fusing Switch for Fault Suppression in the SNS High Voltage Converter Modulators

    SciTech Connect

    Kemp, Mark A.; Burkhart, Craig; Nguyen, Minh N.; Anderson, David E.; /Oak Ridge

    2009-08-03

    The High Voltage Converter Modulators (HVCMs) at the Spallation Neutron Source (SNS) have operated in excess of a combined 250,000 hours. Performance and reliability improvements to the HVCM are ongoing to increase modulator availability as accelerator system demands increase. There is a relatively large amount of energy storage in the HVCMs, {approx}180 kJ. This energy has the potential to dump into unsuppressed faults, cause damage, and increase the time to repair. The 'fusing switch' concept involves isolation of this stored energy from the location of the most common faults. This paper introduces this concept and its application to the HVCMs.

  7. New nanocrystalline materials: a previously unknown simple cubic phase in the SnS binary system.

    PubMed

    Rabkin, Alexander; Samuha, Shmuel; Abutbul, Ran E; Ezersky, Vladimir; Meshi, Louisa; Golan, Yuval

    2015-03-11

    We report a new phase in the binary SnS system, obtained as highly symmetric nanotetrahedra. Due to the nanoscale size and minute amounts of these particles in the synthesis yield, the structure was exclusively solved using electron diffraction methods. The atomic model of the new phase (a = 11.7 Å, P2(1)3) was deduced and found to be associated with the rocksalt-type structure. Kramers-Kronig analysis predicted different optical and electronic properties for the new phase, as compared to α-SnS.

  8. Investigation of novel heterojunction: P-type SnS coated n-type ZnO nanowire

    NASA Astrophysics Data System (ADS)

    Bu, Ian Y. Y.

    2015-12-01

    SnS coated ZnO nanowires heterojunctional solar cells were fabricated using a combination of hydrothermal synthesis and chemical bath deposition (CBD) method. The synthesized materials and devices were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), photoluminescence emission spectroscopy, Uv-Vis spectroscopy and electrical measurements. SEM imaging of the sample revealed that the CBD SnS coating bunches the underlying ZnO nanowires due to the large capillary force it experiences during the drying process. Both of the EDS and XRD measurements confirm the presence of SnS and SnO2. Optoelectronic measurement confirms that the fabricated device exhibit high absorbance (∼80%) and exhibit photovoltaic behaviour.

  9. Taking Stress Response out of the Box: Stability, Discontinuity, and Temperament Effects on HPA and SNS across Social Stressors in Mother-Infant Dyads

    ERIC Educational Resources Information Center

    Laurent, Heidemarie K.; Ablow, Jennifer C.; Measelle, Jeffrey

    2012-01-01

    This study investigated continuity and stability of hypothalamic-pituitary-adrenal (HPA) and sympathetic nervous system (SNS) response measures in mother-infant dyads across 2 different types of social stress sessions. Synchrony of response trajectories across systems (SNS-HPA coordination) and partners (mother-infant attunement) was addressed, as…

  10. Influence of growth conditions on the electrochemical synthesis of SnS thin films and their optical properties

    NASA Astrophysics Data System (ADS)

    Kafashan, Hosein; Jamali-Sheini, Farid; Ebrahimi-Kahrizsangi, Reza; Yousefi, Ramin

    2016-03-01

    Tin sulfide (SnS) thin films were prepared by electrodeposition onto fluorine-doped tin oxide (FTO) glass substrates using an aqueous solution containing SnCl2 and Na2S2O3 at various deposition potentials ( E) and bath concentrations. The pH value and temperature of the solution were kept constant. The deposited films were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), photoluminescence (PL), and ultraviolet-visible (UV-Vis) spectroscopy. The FESEM images demonstrated that changes in the deposition potential ( E) and solution concentration led to marked changes in the morphology of the deposited SnS films. Energy-dispersive X-ray analysis (EDXA) results showed that the Sn/S atomic ratio strongly depended on both the solution concentration and the deposition potential. To obtain an Sn/S atomic ratio approximately equal to 1, the optimal Sn2+/S2O 3 2- molar ratio and E parameter were 1/8 and -1.0 V, respectively. The XRD patterns showed that the synthesized SnS was obviously polycrystalline, with an orthorhombic structure. The effects of the variations of bath concentration and deposition potential on the band-gap energy ( E g) were studied using PL and UV-Vis experiments. The PL spectra of all the SnS films contained two peaks in the visible region and one peak in the infrared (IR) region. The UV-Vis spectra showed that the optical band-gap energy varies from 1.21 to 1.44 eV.

  11. Hierarchical Graphene-Encapsulated Hollow SnO2@SnS2 Nanostructures with Enhanced Lithium Storage Capability.

    PubMed

    Xu, Wangwang; Xie, Zhiqiang; Cui, Xiaodan; Zhao, Kangning; Zhang, Lei; Dietrich, Grant; Dooley, Kerry M; Wang, Ying

    2015-10-14

    Complex hierarchical structures have received tremendous attention due to their superior properties over their constitute components. In this study, hierarchical graphene-encapsulated hollow SnO2@SnS2 nanostructures are successfully prepared by in situ sulfuration on the backbones of hollow SnO2 spheres via a simple hydrothermal method followed by a solvothermal surface modification. The as-prepared hierarchical SnO2@SnS2@rGO nanocomposite can be used as anode material in lithium ion batteries, exhibiting excellent cyclability with a capacity of 583 mAh/g after 100 electrochemical cycles at a specific current of 200 mA/g. This material shows a very low capacity fading of only 0.273% per cycle from the second to the 100th cycle, lower than the capacity degradation of bare SnO2 hollow spheres (0.830%) and single SnS2 nanosheets (0.393%). Even after being cycled at a range of specific currents varied from 100 mA/g to 2000 mA/g, hierarchical SnO2@SnS2@rGO nanocomposites maintain a reversible capacity of 664 mAh/g, which is much higher than single SnS2 nanosheets (374 mAh/g) and bare SnO2 hollow spheres (177 mAh/g). Such significantly improved electrochemical performance can be attributed to the unique hierarchical hollow structure, which not only effectively alleviates the stress resulting from the lithiation/delithiation process and maintaining structural stability during cycling but also reduces aggregation and facilitates ion transport. This work thus demonstrates the great potential of hierarchical SnO2@SnS2@rGO nanocomposites for applications as a high-performance anode material in next-generation lithium ion battery technology.

  12. A novel method of synthesis of small band gap SnS nanorods and its efficient photocatalytic dye degradation.

    PubMed

    Das, Dipika; Dutta, Raj Kumar

    2015-11-01

    A facile one pot method has been developed for synthesis of stable (ξ=-37.5 mV), orthorhombic structured SnS nanorods capped with mercaptoacetic acid by precipitation method. The SnS nanorods were measured to be about 45 nm long with a diameter of 20 nm, as studied by transmission electron microscopy (TEM). The band gap of the MAA capped SnS nanorods was 1.81 eV, measured by diffused reflectance spectroscopy and was larger than the bulk SnS. The relative positions of highest valence band and lowest conduction band were determined from theoretical band structure calculation as 1.58 eV and -0.23 eV, respectively. The UV-Visible-NIR fluorescence emission spectrum of the SnS nanorods revealed intense emission peak at 1000 nm (1.239 eV) and weaker peaks at 935 nm, 1080 nm, 1160 nm which is likely to be due to Sn(2+) vacancies. The as-synthesized SnS nanorods exhibited more than 95% sunlight induced photocatalytic degradation of trypan blue in 4 h, following first order kinetics with high rate of degradation (k) (0.0124 min(-1)). The observed dye degradation is attributable to generation of reactive oxygen species (ROS), confirmed from terephthalic acid assay. The ROS generation has been explained on the basis of interaction between photoexcited electrons from conduction band with molecular oxygen adhered to the surface of nanorods owing to favourable redox potentials of O2/O2(-) (-0.20 eV) in normal hydrogen electrode (NHE) scale.

  13. Kinematic and kinetic comparisons of transfemoral amputee gait using C-Leg and Mauch SNS prosthetic knees.

    PubMed

    Segal, Ava D; Orendurff, Michael S; Klute, Glenn K; McDowell, Martin L; Pecoraro, Janice A; Shofer, Jane; Czerniecki, Joseph M

    2006-01-01

    The C-Leg (Otto Bock, Duderstadt, Germany) is a microprocessor-controlled prosthetic knee that may enhance amputee gait. This intrasubject randomized study compared the gait biomechanics of transfemoral amputees wearing the C-Leg with those wearing a common noncomputerized prosthesis, the Mauch SNS (Ossur, Reykjavik, Iceland). After subjects had a 3-month acclimation period with each prosthetic knee, typical gait biomechanical data were collected in a gait laboratory. At a controlled walking speed (CWS), peak swing phase knee-flexion angle decreased for the C-Leg group compared with the Mauch SNS group (55.2 degrees +/- 6.5 degrees vs 64.41 degrees +/- 5.8 degrees , respectively; p = 0.005); the C-Leg group was similar to control subjects' peak swing knee-flexion angle (56.0 degrees +/- 3.4 degrees ). Stance knee-flexion moment increased for the C-Leg group compared with the Mauch SNS group (0.142 +/- 0.05 vs 0.067 +/- 0.07 N"m, respectively; p = 0.01), but remained significantly reduced compared with control subjects (0.477 +/- 0.1 N"m). Prosthetic limb step length at CWS was less for the C-Leg group compared with the Mauch SNS group (0.66 +/- 0.04 vs 0.70 +/- 0.06 m, respectively; p = 0.005), which resulted in increased symmetry between limbs for the C-Leg group. Subjects also walked faster with the C-Leg versus the Mauch SNS (1.30 +/- 0.1 vs 1.21 +/- 0.1 m/s, respectively; p = 0.004). The C-Leg prosthetic limb vertical ground reaction force decreased compared with the Mauch SNS (96.3 +/- 4.7 vs 100.3 +/- 7.5 % body weight, respectively; p = 0.0092).

  14. Chemical vapor deposition of thin crystals of layered semiconductor SnS2 for fast photodetection application.

    PubMed

    Su, Guoxiong; Hadjiev, Viktor G; Loya, Phillip E; Zhang, Jing; Lei, Sidong; Maharjan, Surendra; Dong, Pei; M Ajayan, Pulickel; Lou, Jun; Peng, Haibing

    2015-01-14

    Layered two-dimensional (2D) semiconductors, such as MoS(2) and SnS(2), have been receiving intensive attention due to their technological importance for the next-generation electronic/photonic applications. We report a novel approach to the controlled synthesis of thin crystal arrays of SnS(2) at predefined locations on chip by chemical vapor deposition with seed engineering and have demonstrated their application as fast photodetectors with photocurrent response time ∼ 5 μs. This opens a pathway for the large-scale production of layered 2D semiconductor devices, important for applications in integrated nanoelectronic/photonic systems.

  15. Project summary

    NASA Technical Reports Server (NTRS)

    1991-01-01

    California Polytechnic State University's design project for the 1990-91 school year was the design of a close air support aircraft. There were eight design groups that participated and were given requests for proposals. These proposals contained mission specifications, particular performance and payload requirements, as well as the main design drivers. The mission specifications called for a single pilot weighing 225 lb with equipment. The design mission profile consisted of the following: (1) warm-up, taxi, take off, and accelerate to cruise speed; (2) dash at sea level at 500 knots to a point 250 nmi from take off; (3) combat phase, requiring two combat passes at 450 knots that each consist of a 360 deg turn and an energy increase of 4000 ft. - at each pass, half of air-to-surface ordnance is released; (4) dash at sea level at 500 knots 250 nmi back to base; and (5) land with 20 min of reserve fuel. The request for proposal also specified the following performance requirements with 50 percent internal fuel and standard stores: (1) the aircraft must be able to accelerate from Mach 0.3 to 0.5 at sea level in less than 20 sec; (2) required turn rates are 4.5 sustained g at 450 knots at sea level; (3) the aircraft must have a reattack time of 25 sec or less (reattack time was defined as the time between the first and second weapon drops); (4) the aircraft is allowed a maximum take off and landing ground roll of 2000 ft. The payload requirements were 20 Mk 82 general-purpose free-fall bombs and racks; 1 GAU-8A 30-mm cannon with 1350 rounds; and 2 AIM-9L Sidewinder missiles and racks. The main design drivers expressed in the request for proposal were that the aircraft should be survivable and maintainable. It must be able to operate in remote areas with little or no maintenance. Simplicity was considered the most important factor in achieving the former goal. In addition, the aircraft must be low cost both in acquisition and operation. The summaries of the aircraft

  16. SNS 2.1K Cold Box Turn-down Studies

    SciTech Connect

    F. Casagrande; P.A. Gurd; D.R. Hatfield; M.P. Howell; W.H. Strong; D. Arenius; J. Creel; V. Ganni; P. Knudsen

    2006-06-26

    The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is nearing completion. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The 2.1K cold box consists of four stages of centrifugal compressors with LN2-cooled variable speed electric motors and magnetic bearings. The cryogenic system successfully supported the Linac beam commissioning at both 4.2K and 2.1K and has been fully operational since June 2005. This paper describes the control principles utilized and the experimental results obtained for the SNS cold compressors turn-down capability to about 30% of the design flow, and possible limitation of the frequency dependent power factor of the cold compressor electric motors, which was measured for the first time during commissioning. These results helped to support the operation of the Linac over a very broad and stable cold compressor operating flow range (refrigeration capacity) and pressure. This in turn helped to optimize the cryogenic system operating parameters, minimizing the utilities and improving the system reliability and availability.

  17. Linear optics correction and observation of electron proton instability in the SNS accumulator ring

    NASA Astrophysics Data System (ADS)

    Liu, Zhengzheng

    The accumulator ring of the Spallation Neutron Source is a high intensity proton storage ring. The choice of its operating tunes is critical. There was a relatively large tune discrepancy ˜ 0.2 between model prediction and real measurement. As a consequence, it was not possible to set the lattice using the model calculation. The orbit response matrix (ORM) method, as programmed in the application code LOCO, was employed to solve the optics discrepancy and calibrate the linear model. Offline study shows that we can attribute most of the tune discrepancy to the errors of quadrupole magnet power supplies, which is up to 2.9%. The results and discussions of proved and potential optics improvement are presented in detail in the thesis. Due to the high intensity of proton beam and the similarity of SNS and PSR, collective instabilities, especially the electron-proton (e-p) instability, pose potential limitations on the peak intensity and therefore become major concerns in the SNS power-up plan. Therefore, although the e-p instability has not emerged in the normal neutron productions yet, we have manipulated the machine setting to observe it in a series of experiments. It shows that, the buncher voltage has little effect on instability threshold and that the instability has a strong dependence on proton bunch shape. Moreover, a potential mitigation of the e-p instability involves the use of a flat top current profile with a short tail. Detailed observation and discussion can be found in the thesis.

  18. Mesoscopic lateral S/N/S weak links: Josephson effects and Josephson-like vortex flow

    NASA Astrophysics Data System (ADS)

    Carapella, G.; Sabatino, P.; Gombos, M.

    2017-02-01

    We report an experimental and numerical study of magneto-transport properties of mesoscopic lateral S/N/S superconducting weak links where the N region is made of the same material as the S banks, though with strongly reduced critical temperature. Magnetoresistance oscillations and clear dc and ac Josephson effects are observed. Experimental results are analyzed in the framework of the time-dependent Ginzburg-Landau model for mesoscopic type II superconductors with an inhomogeneous critical temperature. The analysis suggests that dissipative branches of the current-voltage curve of the weak link in the presence of a magnetic field are accounted for by moving ‘Josephson-like’ vortices. These relatively fast excitations are anisotropic as per the ordinary Josephson vortex in tunnel junctions, but have a normal core like the ordinary Abrikosov vortex in plain superconducting strips. Moreover, unlike the vortex in tunneling junctions, in the lateral S/N/S weak link, the extension of the moving vortex is larger than the extension of the static one. Further, we report in some detail on the lateral proximity effect, and the deviations from the ideality of the current-phase relation of this kind of lateral weak link in the Josephson regime.

  19. Wavelength-Shifting-Fiber Scintillation Detectors for Thermal Neutron Imaging at SNS

    SciTech Connect

    Clonts, Lloyd G; Cooper, Ronald G; Crow, Lowell; Diawara, Yacouba; Ellis, E Darren; Funk, Loren L; Hannan, Bruce W; Hodges, Jason P; Richards, John D; Riedel, Richard A; Wang, Cai-Lin

    2012-01-01

    We have developed wavelength-Shifting-fiber Scintillator Detector (SSD) with 0.3 m2 area per module. Each module has 154 x 7 pixels and a 5 mm x 50 mm pixel size. Our goal is to design a large area neutron detector offering higher detection efficiency and higher count-rate capability for Time-Of-Flight (TOF) neutron diffraction in Spallation Neutron Source (SNS). A ZnS/6LiF scintillator combined with a novel fiber encoding scheme was used to record the neutron events. A channel read-out-card (CROC) based digital-signal processing electronics and position-determination algorithm was applied for neutron imaging. Neutron-gamma discrimination was carried out using pulse-shape discrimination (PSD). A sandwich flat-scintillator detector can have detection efficiency close to He-3 tubes (about 10 atm). A single layer flat-scintillator detector has count rate capability of 6,500 cps/cm2, which is acceptable for powder diffractometers at SNS.

  20. Amines free environmentally friendly rapid synthesis of Cu2SnS3 nanoparticles

    NASA Astrophysics Data System (ADS)

    Lokhande, A. C.; Pawar, S. A.; Jo, Eunjin; He, Mingrui; Shelke, A.; Lokhande, C. D.; Kim, Jin Hyeok

    2016-08-01

    Cubic and tetragonal structured Cu2SnS3 (CTS) nanoparticles are rapidly synthesized within a short reaction time of 5 min using low cost amine free octadecene (ODE) solvent by hot injection technique. The effects of precursor concentration, sulfur source and reaction time on the CTS nanoparticle synthesis are studied. The crystal structure, size, phase purity, atomic composition, oxidation state and optical properties of these nanoparticles are studied in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and UV-visible spectroscopy techniques. Spherical shaped particles in the size range of 25-30 nm are obtained with atomic composition in close agreement with the stoichiometry of Cu2SnS3. The reaction mechanism of CTS nanoparticle formation is proposed. The synthesized cubic and tetragonal structured CTS nanoparticles exhibit optimal band gaps of 1.23 eV and 1.45 eV, respectively, suitable for use in photovoltaic applications.

  1. Programming PLCS under EPICS at the SNS Project : Further Experiences in Collaboration

    SciTech Connect

    P. A. Gurd; W. H. Strong; J. D. Creel

    2003-10-01

    The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Tennessee by a partnership of six national laboratories. The control system components for the SNS were produced by personnel at the collaborating laboratories, by vendors of the equipment, and by commercial contractors. A number of different approaches were used to provide the programming for both the programmable logic controllers (PLCs) and the input-output controllers (IOCs) which were all based on the Experimental Physics and Industrial Control System (EPICS). For conventional facilities, both the PLCs and the IOCs were programmed under a commercial contract. The PLCs for the high power radio frequency system (HPRF) were programmed by the vendors of the equipment, while the IOCs were programmed by the collaborating laboratory. Finally, while the IOCs for the cryogenic systems were programmed at Oak Ridge, three different approaches were used to produce the PLC programming: some were programmed at Oak Ridge, some at TJNAF, and some at vendor sites. This paper discusses the status of the PLCs in the control system and the integration challenges encountered in the various approaches.

  2. RF Distribution System for High Power Test of the SNS Cryomodule

    SciTech Connect

    Lee, Sung-Woo; Kang, Yoon W; Broyles, Michael R; Crofford, Mark T; Geng, Xiaosong; Kim, Sang-Ho; Phibbs, Curtis L; Strong, William Herb; Peglow, Robert C; Vassioutchenko, Alexandre V

    2012-01-01

    A four-way waveguide RF power distribution system for testing the Spallation Neutron Source (SNS) multi-cavity cryomodule to investigate the collective behavior has been developed. A single klystron operating at 805MHz for 1.3 msec at 60Hz powers the 4-way waveguide splitter to deliver up to 400 kW to individual cavities. Each cavity is fed through a combination of waveguide splitters and vector modulators (VM) to provide independent magnitude and phase controls. The waveguide vector modulator consists of two quadrature hybrids and two motorized waveguide phase shifters. The phase shifters and the assembled waveguide vector modulators were individually tested and characterized for low power and high RF power in the SNS RF test facility. Precise calibrations of magnitude and phase were performed to generate the look up tables (LUTs) to provide operational references during the cryomodule test. An I-Q demodulator module was developed and utilized to measure relative phases in pulsed high RF power operation. PLC units were developed for mechanical control of the phase shifters. Initial low/high power measurements were made using LabVIEW. An operation algorithm has been implemented into EPICS control for the cryomodule test stand.

  3. 77 FR 53163 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-31

    ... TRANSPORTATION BARRIERS COMPLIANCE BOARD 36 CFR Part 1195 RIN 3014-AA40 Medical Diagnostic Equipment.... ACTION: Notice of advisory committee meeting. SUMMARY: The Medical Diagnostic Equipment Accessibility...) on Medical Diagnostic Equipment Accessibility Standards. See 77 FR 6916 (February 9, 2012). The...

  4. Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

    NASA Astrophysics Data System (ADS)

    Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook

    2017-04-01

    Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

  5. High-T(sub c) Edge-geometry SNS Weak Links on Silicon-on-sapphire Substrates

    NASA Technical Reports Server (NTRS)

    Hunt, B.; Foote, M.; Pike, W.; Barner, J.; Vasquez, R.

    1994-01-01

    High-quality superconductor/normal-metal/superconductor(SNS) edge-geometry weak links have been produced on silicon-on-sapphire (SOS) substrates using a new SrTiO(sub 3)/'seed layer'/cubic-zirconia (YS2) buffer system.

  6. Photo-enhanced salt-water splitting using orthorhombic Ag8SnS6 photoelectrodes in photoelectrochemical cells

    NASA Astrophysics Data System (ADS)

    Cheng, Kong-Wei; Tsai, Wei-Tseng; Wu, Yu-Hsuan

    2016-06-01

    Orthorhombic Ag8SnS6 photoelectrodes are prepared on various substrates via reactive sulfurization using the radio-frequency magnetron sputtering of silver-tin metal precursors. Evaluations of the photoelectrochemical performances of Ag8SnS6 photoelectrodes with various levels of silver content are carried out in various aqueous solutions. X-ray diffraction patterns and Hall measurements of samples after a three-stage sulfurization process show that all samples are the pure orthorhombic Ag8SnS6 phase with n-type conductivity. The energy band gaps, carrier concentrations, and mobilities of samples on glass substrates are 1.31-1.33 eV, 7.07 × 1011-8.52 × 1012 cm-3, and 74.9-368 cm2 V-1 s-1, respectively, depending on the [Ag]/[Ag+Sn] molar ratio in samples. The highest photoelectrochemical performances of orthorhombic Ag8SnS6 photoelectrodes in aqueous 0.35 M Na2S + 0.25 M K2SO3 and 0.5 M NaCl solutions are respectively 2.09 and 2.5 mA cm-2 at an applied voltages of 0.9 and 1.23 V vs. a reversible hydrogen electrode under light irradiation with a light intensity of 100 mW cm-2 from a 300-W Xe lamp.

  7. One-step diffusion membrane assisted CBD synthesis and characterization of Cu2SnS3 thin films

    NASA Astrophysics Data System (ADS)

    Becerra, R. A.; Correa, J. M.; Suarez, H.; Gordillo, G.

    2014-04-01

    This paper present a novel method for growing thin films of Cu2SnS3 (CTS) using a solution-based chemical route consisting of simultaneous precipitation of Cu2-xS and SnS2 performed by diffusion membranes assisted CBD technique. Diffusion membranes are used to optimize the kinetic growth through a moderate control of the releasing metal into the solution. The conditions in terms of concentration of metal species, sulfide anion and temperature required for the precipitation of the Cu2SnS3 compound were determined through a study of chemical equilibrium of the system SnCl2, Na3C6H5O7·2H2O, CuCl2 and Na2S2O3·5H2O. These conditions were obtained solving the equilibrium equations with the help of the Visual MINTEQ 3.0 package, supported on the program MINTEQA2. X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the structural properties of the CTS films. Optical, morphological and electrical properties were also studied by spectral transmittance, atomic force microscopy (AFM) and resistivity vs temperature measurements. XRD and Raman measurements confirmed the formation of the Cu2SnS3 phase.

  8. Vanadium Nitride Nanowire Supported SnS2 Nanosheets with High Reversible Capacity as Anode Material for Lithium Ion Batteries.

    PubMed

    Balogun, Muhammad-Sadeeq; Qiu, Weitao; Jian, Junhua; Huang, Yongchao; Luo, Yang; Yang, Hao; Liang, Chaolun; Lu, Xihong; Tong, Yexiang

    2015-10-21

    The vulnerable restacking problem of tin disulfide (SnS2) usually leads to poor initial reversible capacity and poor cyclic stability, which hinders its practical application as lithium ion battery anode (LIB). In this work, we demonstrated an effective strategy to improve the first reversible capacity and lithium storage properties of SnS2 by growing SnS2 nanosheets on porous flexible vanadium nitride (VN) substrates. When evaluating lithium-storage properties, the three-dimensional (3D) porous VN coated SnS2 nanosheets (denoted as CC-VN@SnS2) yield a high reversible capacity of 75% with high specific capacity of about 819 mAh g(-1) at a current density of 0.65 A g(-1). Remarkable cyclic stability capacity of 791 mAh g(-1) after 100 cycles with excellent capacity retention of 97% was also achieved. Furthermore, discharge capacity as high as 349 mAh g(-1) is still retained after 70 cycles even at a elevated current density of 13 A g(-1). The excellent performance was due to the conductive flexible VN substrate support, which provides short Li-ion and electron pathways, accommodates large volume variation, contributes to the capacity, and provides mechanical stability, which allows the electrode to maintain its structural stability.

  9. A look ahead: Status of the SNS external antenna ion source and the new RFQ test stand

    SciTech Connect

    Welton, R. F. Aleksandrov, A.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, M.; Kang, Y.; Santana, M.; Stockli, M. P.; Dudnikov, V. G.

    2015-04-08

    The U.S. Spallation Neutron Source (SNS) now operates with ∼1 MW of beam power to target with the near-term goal of delivering 1.4 MW. Plans are being considered to incorporate a second target station into the facility which will require ∼2.8 MW of beam power. Presently, H{sup −} beam pulses (∼1 ms, 60 Hz) are produced by an RF-driven, Cs-enhanced, multi-cusp ion source which injects beam into an RFQ (Radio Frequency Quadrupole) accelerator that, in turn, feeds the SNS Linac. Currently the source/RFQ system delivers ∼35 mA of pulsed current to the linac which is mostly sufficient for 1.4 MW operations while ∼50 mA are needed for the second target station upgrade. This paper provides a look forward for the SNS by providing (i) the present and future SNS source/RFQ beam requirements and our plans to achieve these, (ii) a description and status of the external antenna ion source being developed for the replacement of the current internal antenna ion source, and (iii) a description and status of the newly constructed RFQ test facility.

  10. Lithiation of Li2SnO3 and Li2SnS3 in context of Li-ion battery materials

    NASA Astrophysics Data System (ADS)

    Howard, Jason; Holzwarth, N. A. W.

    The closed pack layered crystal material (space group 15 (C 2 / c)) Li2 SnO3 has been studied as a possible anode material since the late 1990's. The material undergoes an irreversible decomposition to Li2 O and LiX Sn alloys during the first lithiation cycle. The crystal material Li2 SnS3 of the same structure was recently proposed as an electrolyte material. The question is posed whether Li2 SnS3 would be a good electrolyte or whether it could function as an anode material similar to Li2 SnO3 . In this research a model is proposed for the lithiation process of Li2 SnO3 and Li2 SnS3 ; Li - Li2 SnS3 interfaces are also examined. The results show Li2 SnO3 begins to decompose at approximately Li2 + 0 . 5 SnO3 . In Li2 SnS3 the lithiation process shows it can lithiate to Li2 + 1 SnS3 without significant lattice distortion, volume expansion, or decomposition. Li - Li2 SnS3 interfaces are shown to be unstable, showing the formation of Li2 S . Supported by NSF Grant DMR-1105485 and DMR-1507942.

  11. The implementation of the graphics of program EAGLE: A numerical grid generation code on NASA Langley SNS computer system

    NASA Technical Reports Server (NTRS)

    Houston, Johnny L.

    1989-01-01

    Program EAGLE (Eglin Arbitrary Geometry Implicit Euler) Numerical Grid Generation System is a composite (multi-block) algebraic or elliptic grid generation system designed to discretize the domain in and/or around any arbitrarily shaped three dimensional regions. This system combines a boundary conforming surface generation scheme and includes plotting routines designed to take full advantage of the DISSPLA Graphics Package (Version 9.0). Program EAGLE is written to compile and execute efficiently on any Cray machine with or without solid state disk (SSD) devices. Also, the code uses namelist inputs which are supported by all Cray machines using the FORTRAN compiler CFT77. The namelist inputs makes it easier for the user to understand the inputs and operation of Program EAGLE. EAGLE's numerical grid generator is constructed in the following form: main program, EGG (executive routine); subroutine SURFAC (surface generation routine); subroutine GRID (grid generation routine); and subroutine GRDPLOT (grid plotting routines). The EAGLE code was modified to use on the NASA-LaRC SNS computer (Cray 2S) system. During the modification a conversion program was developed for the output data of EAGLE's subroutine GRID to permit the data to be graphically displayed by IRIS workstations, using Plot3D. The code of program EAGLE was modified to make operational subroutine GRDPLOT (using DI-3000 Graphics Software Packages) on the NASA-LaRC SNS Computer System. How to implement graphically, the output data of subroutine GRID was determined on any NASA-LaRC graphics terminal that has access to the SNS Computer System DI-300 Graphics Software Packages. A Quick Reference User Guide was developed for the use of program EAGLE on the NASA-LaRC SNS Computer System. One or more application program(s) was illustrated using program EAGLE on the NASA LaRC SNS Computer System, with emphasis on graphics illustrations.

  12. Layer-dependent properties of SnS2 and SnSe2 two-dimensional materials

    NASA Astrophysics Data System (ADS)

    Gonzalez, Joseph M.; Oleynik, Ivan I.

    2016-09-01

    The layer-dependent structural, electronic, and vibrational properties of SnS2 and SnSe2 are investigated using first-principles density functional theory (DFT). The in-plane lattice constants, interlayer distances and binding energies are found to be layer-independent. Bulk SnS2 and SnSe2 are both indirect band gap semiconductors with Eg=2.18 and 1.07 eV , respectively. Few-layer and monolayer 2D systems also possess an indirect band gap, which is increased to 2.41 and 1.69 eV for single layers of SnS2 and SnSe2. The effective mass theory of 2D excitons, which takes into account the combined effect of the anisotropy, nonlocal 2D screening and layer-dependent 3D screening, predicts strong excitonic effects. The binding energy of indirect excitons in monolayer samples, Ex˜0.9 eV , is substantially reduced to Ex=0.14 eV in bulk SnS2 and Ex=0.09 eV in bulk SnSe2. The layer-dependent Raman spectra display a strong decrease of intensities of the Raman active A1 g mode upon decreasing the number of layers down to a monolayer, by a factor of 7 in the case of SnS2 and a factor of 20 in the case of SnSe2, which can be used to identify the number of layers in a 2D sample.

  13. Strain-induced indirect-to-direct band-gap transition in bulk SnS2

    NASA Astrophysics Data System (ADS)

    Ram, Babu; Singh, Abhishek K.

    2017-02-01

    While SnS2 is an earth-abundant large-band-gap semiconductor material, the indirect nature of the band gap limits its applications in light harvesting or detection devices. Here, using density functional theory in combination with the many-body perturbation theory, we report indirect-to-direct band-gap transition in bulk SnS2 under moderate, 2.98 % uniform biaxial tensile (BT) strain. Further enhancement of the BT strain up to 9.75 % leads to a semiconductor-to-metal transition. The strain-induced weakening of the interaction of the in-plane orbitals modifies the dispersion as well as the character of the valence- and the conduction-band edges, leading to the transition. A quasiparticle direct band gap of 2.17 eV at the Γ point is obtained at 2.98 % BT strain. By solving the Bethe-Salpeter equation to include excitonic effects on top of the partially self-consistent GW0 calculation, we study the dielectric functions, optical oscillator strength, and exciton binding energy as a function of the applied strain. At 2.98 % BT strain, our calculations show the relatively high exciton binding energy of 170 meV, implying strongly coupled excitons in SnS2. The effect of strain on vibrational properties, including Raman spectra, is also investigated. The Raman shift of both in-plane (E2g 1) and out-of plane (A1 g) modes decreases with the applied BT strain, which can be probed experimentally. Furthermore, SnS2 remains dynamically stable up to 9.75 % BT strain, at which it becomes metallic. A strong coupling between the applied strain and the electronic and optical properties of SnS2 can significantly broaden the applications of this material in strain-detection and optoelectronic devices.

  14. [Thalassaemia diagnostics].

    PubMed

    Kusters, Elske; Kerkhoffs, Jean-Louis H; van Rossum, André P

    2014-01-01

    The thalassaemias are characterised by quantitative aberrations in the production of the globin chains that make up haemoglobin, and are a subgroup of the haemoglobinopathies. In this LabQuiz we show how thalassaemia carrier status can be indicated in the results of regular laboratory tests, and discuss the laboratory diagnostics that can confirm or rule out thalassaemia. In these two cases we will present a man of Moroccan descent, and two brothers of Filipino descent, all with anaemia and microcytosis. We show it is possible to differentiate between iron-deficiency anaemia and thalassaemia carrier status on the basis of a complete blood count and measurement of ferritin levels, and which laboratory diagnostics can be subsequently performed in order to confirm a suspicion of thalassaemia. The background section discusses the properties and pitfalls of routine laboratory diagnostics for the thalassaemias, and thalassaemia diagnostics in the Dutch newborn screening programme.

  15. Estimate of Dose and Residual Activity in the SNS Ring Collimation Straight

    NASA Astrophysics Data System (ADS)

    Ludewig, H.; Simos, N.; Davino, D.; Cousineau, S.; Catalan-Lasheras, N.; Brodowski, J.; Tuozzolo, J.; Longo, C.; Mullany, B.; Raparia, D.

    2003-12-01

    The collimation system in the SNS ring includes a two-stage collimator consisting of a halo scraper and an appropriate fixed aperture collimator. This unit is placed between the first quadru-pole and the first doublet in the collimation straight section of the ring. The entire structure is surrounded by an outer shield structure. The downstream dose to the doublet and the attached corrector magnet will be estimated for normal operating conditions. In addition, the activities of cooling water, tunnel air, and dose to cables will be estimated. The dose at the flange locations will be estimated following machine shutdown. Finally, the implied dose to surroundings during the removal of an exposed collimator will be made.

  16. SUPERCONDUCTING LINAC UPGRADE PLAN FOR THE SECOND TARGET STATION PROJECT AT SNS

    SciTech Connect

    Kim, Sang-Ho; Doleans, Marc; Galambos, John D; Howell, Matthew P; Mammosser, John

    2015-01-01

    The beam power of the Linac for the Second Target Station (STS) at the Spallation Neutron Source (SNS) will be doubled to 2.8 MW. For the energy upgrade, seven additional cryomodules will be installed in the reserved space at the end of the linac tunnel to produce linac output energy of 1.3 GeV. The cryomodules for STS will have the same physical length but will incorporate some design changes based on the lessons learned from operational experience over the last 10 years and from the high beta spare cryomodule developed in house. The average macro-pulse beam current for the STS will be 38 mA which is about a 40 % increase from the present beam current for 1.4 MW operation. Plans for the new cryomodules and for the existing cryomodules to support higher beam current for the STS are presented in this paper.

  17. Development of the neutron electric dipole moment experiment at the SNS

    NASA Astrophysics Data System (ADS)

    Cooper, Martin D.

    2009-10-01

    The nEDM Collaboration is preparing an experiment to run at the Spallation Neutron Source (SNS) to search for the neutron electric dipole moment (EDM) experiment with a sensitivity of <10-27 e.cm based on the scheme of Golub and Lamoreaux. The collaboration has been pursuing a R&D program to establish the technical feasibility of the design. Many results have been obtained from independent experiments that demonstrate the EDM experiment should work. The data from a number of these preparatory measurements will be presented and discussed in terms of their importance to the final design. The engineering of the project is now ready to produce shop drawings, so a comprehensive picture of the apparatus can be presented.

  18. PRELIMINARY DESIGN OF THE BEAM LOSS MONITORING SYSTEM FOR THE SNS.

    SciTech Connect

    WITKOVER,R.; GASSNER,D.

    2002-05-06

    The SNS to be built at Oak Ridge National Laboratory will provide a high average intensity 1 GeV beam to produce spallation neutrons. Loss of a even small percentage of this intense beam would result in high radiation. The Beam Loss Monitor (ELM) system must detect such small, long term losses yet be capable of measuring infrequent short high losses. The large dynamic range presents special problems for the system design. Ion chambers will be used as the detectors. A detector originally designed for the FNAL Tevatron, was considered but concerns about ion collection times and low collection efficiency at high loss rates favor a new design. The requirements and design concepts of the proposed approach will be presented. Discussion of the design and testing of the ion chambers and the analog j-Point end electronics will be presented. The overall system design will be described.

  19. Next Generation IGBT Switch Plate Development for the SNS High Voltage Converter Modulator

    SciTech Connect

    Kemp, Mark A.; Burkhart, Craig; Nguyen, Minh N.; Anderson, David E.; /Oak Ridge

    2008-09-18

    The RF source High Voltage Converter Modulator (HVCM) systems installed on the Spallation Neutron Source (SNS) have operated well in excess of 200,000 hours, during which time numerous failures have occurred. An improved Insulated Gate Bipolar Transistor (IGBT) switch plate is under development to help mitigate these failures. The new design incorporates two significant improvements. The IGBTs are upgraded to 4500 V, 1200 A, press-pack devices, which increase the voltage margin, facilitate better cooling, and eliminate explosive disassembly of the package in the event of device failure. The upgrade to an advanced IGBT gate drive circuit decreases switching losses and improves fault-condition response. The upgrade design and development status will be presented.

  20. Model of a SNS Electrostatic LEBT with a Near-Ground Beam Chopper

    NASA Astrophysics Data System (ADS)

    Han, B. X.; Stockli, M. P.

    2009-03-01

    The low energy beam transport (LEBT) of the Spallation Neutron Source (SNS) accelerator consists of two electrostatic lenses, of which the second is split into four electrically-isolated segments. Adding fast pulsed voltages to the lens high voltage creates the transverse fields required for beam chopping. Electric sparks, however, create transients that enter the fast high-voltage switches, which are occasionally damaged and cause machine downtime. This work models a new configuration of the electrostatic LEBT, which chops the beam with four shielded, near-ground electrodes between the two lenses. The model shows that the new configuration can match the RFQ injection requirements and sufficiently deflect the beam in the phase-space using the same chopping voltages as in the baseline LEBT.

  1. Recent Performance of and Plasma Outage Studies with the SNS H- Source

    SciTech Connect

    Stockli, Martin P; Han, Baoxi; Murray Jr, S N; Pennisi, Terry R; Piller, Chip; Santana, Manuel; Welton, Robert F

    2016-01-01

    SNS ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised RFQ, which requires higher RF power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ~55-kW 2-MHz plasma pulses reflecting ~90% of the continuous ~300W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly-detuned 13-MHz match. Lowering the H2 also increased the H- beam current to ~55 mA, and increased the transmission by ~7%.

  2. Ballistic and diffusive regimes in current-phase relations of graphene SNS heterojunctions

    NASA Astrophysics Data System (ADS)

    Kratz, Philip; Amet, Francois; Watson, Christopher; Moler, Kathryn; Ke, Chung; Borzenets, Ivan; Watanabe, Kenji; Taniguchi, Takashi; Deacon, Russell; Yamamoto, Michihisa; Bomze, Yuriy; Tarucha, Seigo; Finkelstein, Gleb

    Current-phase relations (CPRs) are an indirect measurement of the energy distribution of phase-coherent modes in Josephson junctions through the spectral supercurrent near equilibrium, probing low-energy excitations not accessible by transport. We report on planned experimental measurements of the CPRs of gated, high-mobility (105 cm2/Vs) single-layer graphene SNS heterojunctions in ring geometries with superconducting MoRe alloy contacts, inductively read out with a scanning superconducting quantum interference device (SQUID) magnetometer. The graphene layers are encapsulated on both sides with hexagonal-BN (h-BN). We will address the CPR dependence on experimentally tunable parameters (temperature, carrier density, and channel length), and possible crossovers between the ballistic and diffusive regimes.

  3. Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions

    SciTech Connect

    Black-Schaffer, Annica M.

    2010-04-06

    We use a tight-binding Bogoliubov-de Gennes (BdG) formalism to self-consistently calculate the proximity effect, Josephson current, and local density of states in ballistic graphene SNS Josephson junctions. Both short and long junctions, with respect to the superconducting coherence length, are considered, as well as different doping levels of the graphene. We show that self-consistency does not notably change the current-phase relationship derived earlier for short junctions using the non-selfconsistent Dirac-BdG formalism but predict a significantly increased critical current with a stronger junction length dependence. In addition, we show that in junctions with no Fermi level mismatch between the N and S regions superconductivity persists even in the longest junctions we can investigate, indicating a diverging Ginzburg-Landau superconducting coherence length in the normal region.

  4. Advanced valve motor operator diagnostic system

    SciTech Connect

    Thibault, C.

    1989-01-01

    A brief summary of the current use of diagnostic applications to motor-operated valves (MOVs) to satisfy the requirements of IE Bulletin 85-03, IE 85-03 (Supplement 1), and preventive maintenance applications is presented in this paper. This paper explains a new system for diagnostics, signature analysis, and direct measurement of actual load on MOV in the closed direction. This advanced valve motor operator diagnostic system (AVMODS) system comprises two complementary segments: (1) valve motor operator diagnostic system (V-MODS) and (2) motor current signature analysis (MCSA). AVMODS technical considerations regarding V-MODS and MCSA are discussed.

  5. Effects of SNS activation on SSRI-induced sexual side effects differ by SSRI.

    PubMed

    Ahrold, Tierney K; Meston, Cindy M

    2009-01-01

    Selective serotonin reuptake inhibitors (SSRIs) are associated with significant sexual side effects. By definition, all SSRIs increase overall serotonin (5HT) by binding to serotonin autoreceptors (5HT(IA)); however, each SSRI has a unique portfolio of secondary binding properties to other neurotransmitters such as norepinephrine (NE). As 5HT(IA) receptors mediate NE neurotransmission, SSRIs that are highly selective for 5HT(IA) are more likely to reduce NE efficiency; however, in SSRIs that are less selective for 5HT(IA), this could be counteracted by secondary binding to NE. Norepinephrine is the major neurotransmitter of the sympathetic nervous system (SNS), which has been shown to mediate genital arousal in women; thus, it is possible that increasing SNS activity in women taking SSRIs that are highly selective for 5HT(IA) may counteract sexual side effects in those women. To test this hypothesis, we conducted a reanalysis of Meston (2004)'s 8-week, double-blind, cross-over, placebo-controlled study of the effects of ephedrine (50 mg taken 1 h prior to sexual activity) on self-reported sexual functioning of women taking paroxetine (N = 5), sertraline (N = 7), or fluoxetine (N = 7). As predicted, women taking SSRIs, which are highly selective for 5HT(IA) (sertraline, paroxetine), showed improvement in sexual arousal and orgasm. By contrast, women taking SSRIs, which are less selective for 5HT(IA) relative to NE (fluoxetine), showed no change or decrease in sexual functioning. These findings have implications for treating certain SSRI-induced sexual side effects.

  6. Effects and Correction of Closed Orbit Magnet Errors in the SNS Ring

    SciTech Connect

    Bunch, S.C.; Holmes, J.

    2004-01-01

    We consider the effect and correction of three types of orbit errors in SNS: quadrupole displacement errors, dipole displacement errors, and dipole field errors. Using the ORBIT beam dynamics code, we focus on orbit deflection of a standard pencil beam and on beam losses in a high intensity injection simulation. We study the correction of these orbit errors using the proposed system of 88 (44 horizontal and 44 vertical) ring beam position monitors (BPMs) and 52 (24 horizontal and 28 vertical) dipole corrector magnets. Correction is carried out numerically by adjusting the kick strengths of the dipole corrector magnets to minimize the sum of the squares of the BPM signals for the pencil beam. In addition to using the exact BPM signals as input to the correction algorithm, we also consider the effect of random BPM signal errors. For all three types of error and for perturbations of individual magnets, the correction algorithm always chooses the three-bump method to localize the orbit displacement to the region between the magnet and its adjacent correctors. The values of the BPM signals resulting from specified settings of the dipole corrector kick strengths can be used to set up the orbit response matrix, which can then be applied to the correction in the limit that the signals from the separate errors add linearly. When high intensity calculations are carried out to study beam losses, it is seen that the SNS orbit correction system, even with BPM uncertainties, is sufficient to correct losses to less than 10-4 in nearly all cases, even those for which uncorrected losses constitute a large portion of the beam.

  7. SIMULATION AND MOCKUP OF SNS JET-FLOW TARGET WITH WALL JET FOR CAVITATION DAMAGE MITIGATION

    SciTech Connect

    Wendel, Mark W; Geoghegan, Patrick J; Felde, David K

    2014-01-01

    Pressure waves created in liquid mercury pulsed spallation targets at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory induce cavitation damage on the stainless steel target container. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. Severe through-wall cavitation damage on an internal wall near the beam entrance window has been observed in spent-targets. Surprisingly though, there is very little damage on the walls that bound an annular mercury channel that wraps around the front and outside of the target. The mercury flow through this channel is characterized by smooth, attached streamlines. One theory to explain this lack of damage is that the uni-directional flow biases the direction of the collapsing cavitation bubble, reducing the impact pressure and subsequent damage. The theory has been reinforced by in-beam separate effects data. For this reason, a second-generation SNS mercury target has been designed with an internal wall jet configuration intended to protect the concave wall where damage has been observed. The wall jet mimics the annular flow channel streamlines, but since the jet is bounded on only one side, the momentum is gradually diffused by the bulk flow interactions as it progresses around the cicular path of the target nose. Numerical simulations of the flow through this jet-flow target have been completed, and a water loop has been assembled with a transparent test target in order to visualize and measure the flow field. This paper presents the wall jet simulation results, as well as early experimental data from the test loop.

  8. SnS thin films prepared by H2S-free process and its p-type thin film transistor

    NASA Astrophysics Data System (ADS)

    Ran, Fan-Yong; Xiao, Zewen; Hiramatsu, Hidenori; Ide, Keisuke; Hosono, Hideo; Kamiya, Toshio

    2016-01-01

    Polycrystalline SnS thin films were fabricated by a H2S-free process combing pulsed laser deposition at room temperature and post-deposition thermal annealing in Ar. Thermal annealing improved the crystalline quality of the SnS films and the best films were obtained by 400 °C annealing. The obtained SnS films exhibited p-type conduction with the highest Hall mobility of 28 cm2/(V ṡ s) and the carrier densities of 1.5 × 1015 - 1.8 × 1016 cm-3. The SnS TFT exhibited p-type operation with a field effect mobility and an on-off drain current ratio of 0.4 cm2/(V ṡ s) and 20, respectively.

  9. Astrovirus Diagnostics

    PubMed Central

    Pérot, Philippe; Lecuit, Marc; Eloit, Marc

    2017-01-01

    Various methods exist to detect an astrovirus infection. Current methods include electron microscopy (EM), cell culture, immunoassays, polymerase chain reaction (PCR) and various other molecular approaches that can be applied in the context of diagnostic or in surveillance studies. With the advent of metagenomics, novel human astrovirus (HAstV) strains have been found in immunocompromised individuals in association with central nervous system (CNS) infections. This work reviews the past and current methods for astrovirus detection and their uses in both research laboratories and for medical diagnostic purposes. PMID:28085120

  10. A Cross-Cultural Examination of SNS Usage Intensity and Managing Interpersonal Relationships Online: The Role of Culture and the Autonomous-Related Self-Construal.

    PubMed

    Lee, Soon Li; Kim, Jung-Ae; Golden, Karen Jennifer; Kim, Jae-Hwi; Park, Miriam Sang-Ah

    2016-01-01

    Perception of the autonomy and relatedness of the self may be influenced by one's experiences and social expectations within a particular cultural setting. The present research examined the role of culture and the Autonomous-Related self-construal in predicting for different aspects of Social Networking Sites (SNS) usage in three Asian countries, especially focusing on those aspects serving interpersonal goals. Participants in this cross-cultural study included 305 university students from Malaysia (n = 105), South Korea (n = 113), and China (n = 87). The study explored specific social and interpersonal behaviors on SNS, such as browsing the contacts' profiles, checking for updates, and improving contact with SNS contacts, as well as the intensity of SNS use, hypothesizing that those with high intensity of use in the Asian context may be doing so to achieve the social goal of maintaining contact and keeping updated with friends. Two scales measuring activities on other users' profiles and contact with friends' profiles were developed and validated. As predicted, some cross-cultural differences were found. Koreans were more likely to use SNS to increase contact but tended to spend less time browsing contacts' profiles than the Malaysians and Chinese. The intensity of SNS use differed between the countries as well, where Malaysians reported higher intensity than Koreans and Chinese. Consistent with study predictions, Koreans were found with the highest Autonomous-Related self-construal scores. The Autonomous-Related self-construal predicted SNS intensity. The findings suggest that cultural contexts, along with the way the self is construed in different cultures, may encourage different types of SNS usage. The authors discuss study implications and suggest future research directions.

  11. A Cross-Cultural Examination of SNS Usage Intensity and Managing Interpersonal Relationships Online: The Role of Culture and the Autonomous-Related Self-Construal

    PubMed Central

    Lee, Soon Li; Kim, Jung-Ae; Golden, Karen Jennifer; Kim, Jae-Hwi; Park, Miriam Sang-Ah

    2016-01-01

    Perception of the autonomy and relatedness of the self may be influenced by one's experiences and social expectations within a particular cultural setting. The present research examined the role of culture and the Autonomous-Related self-construal in predicting for different aspects of Social Networking Sites (SNS) usage in three Asian countries, especially focusing on those aspects serving interpersonal goals. Participants in this cross-cultural study included 305 university students from Malaysia (n = 105), South Korea (n = 113), and China (n = 87). The study explored specific social and interpersonal behaviors on SNS, such as browsing the contacts' profiles, checking for updates, and improving contact with SNS contacts, as well as the intensity of SNS use, hypothesizing that those with high intensity of use in the Asian context may be doing so to achieve the social goal of maintaining contact and keeping updated with friends. Two scales measuring activities on other users' profiles and contact with friends' profiles were developed and validated. As predicted, some cross-cultural differences were found. Koreans were more likely to use SNS to increase contact but tended to spend less time browsing contacts' profiles than the Malaysians and Chinese. The intensity of SNS use differed between the countries as well, where Malaysians reported higher intensity than Koreans and Chinese. Consistent with study predictions, Koreans were found with the highest Autonomous-Related self-construal scores. The Autonomous-Related self-construal predicted SNS intensity. The findings suggest that cultural contexts, along with the way the self is construed in different cultures, may encourage different types of SNS usage. The authors discuss study implications and suggest future research directions. PMID:27148100

  12. Tuning band gap of monolayer and bilayer SnS2 by strain effect and external electric field: A first principles calculations

    NASA Astrophysics Data System (ADS)

    Rahman, Abeera; Shin, Young-Han

    Recently many efforts have been paid to two-dimensional layered metal dichalcogenides (LMDs). Among them MoS2 has become a prototype LMD, and recent studies show surprising and rich new physics emerging in other van der Waals materials such as layered SnS2 [1-4]. SnS2 is a semiconducting earth-abundant material and Sn is a group IV element replacing the transition metal in MoS2. SnS2 shows new possibilities in various potential applications. However, the knowledge on basic properties of layered SnS2 is still not well understood. In this study, we consider two types of structures; 1T with P 3 m 1 (164) space group and 1H with P63 / mmc (194) space group. Our first principles calculations show that the 1T structure for SnS2 is more stable than the 1H structure whereas latter is more stable for MoS2. Moreover,in contrast to MoS2,SnS2 shows an indirect band gap both for 1T and 1H structures while 1T MoS2 is metallic and 1H has a direct band gap. We also study strain effect in the range of 0-10% on the band structure for monolayer and bilayer SnS2 (both for 1T and 1H structures).We find significant change in their band gaps. We also investigate the bilayer SnS2 with and without out-of-plane stress. This research was supported by Brain Korea 21 Plus Program and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planning (NRF-2014M3A7B4049367, NRF-2014R1A2A1A1105089).

  13. Thermoelectric SnS and SnS-SnSe solid solutions prepared by mechanical alloying and spark plasma sintering: Anisotropic thermoelectric properties

    PubMed Central

    Asfandiyar; Wei, Tian-Ran; Li, Zhiliang; Sun, Fu-Hua; Pan, Yu; Wu, Chao-Feng; Farooq, Muhammad Umer; Tang, Huaichao; Li, Fu; Li, Bo; Li, Jing-Feng

    2017-01-01

    P–type SnS compound and SnS1−xSex solid solutions were prepared by mechanical alloying followed by spark plasma sintering (SPS) and their thermoelectric properties were then studied in different compositions (x = 0.0, 0.2, 0.5, 0.8) along the directions parallel (//) and perpendicular (⊥) to the SPS–pressurizing direction in the temperature range 323–823 Κ. SnS compound and SnS1−xSex solid solutions exhibited anisotropic thermoelectric performance and showed higher power factor and thermal conductivity along the direction ⊥ than the // one. The thermal conductivity decreased with increasing contents of Se and fell to 0.36 W m−1 K−1 at 823 K for the composition SnS0.5Se0.5. With increasing selenium content (x) the formation of solid solutions substantially improved the electrical conductivity due to the increased carrier concentration. Hence, the optimized power factor and reduced thermal conductivity resulted in a maximum ZT value of 0.64 at 823 K for SnS0.2Se0.8 along the parallel direction. PMID:28240324

  14. Thermoelectric SnS and SnS-SnSe solid solutions prepared by mechanical alloying and spark plasma sintering: Anisotropic thermoelectric properties.

    PubMed

    Asfandiyar; Wei, Tian-Ran; Li, Zhiliang; Sun, Fu-Hua; Pan, Yu; Wu, Chao-Feng; Farooq, Muhammad Umer; Tang, Huaichao; Li, Fu; Li, Bo; Li, Jing-Feng

    2017-02-27

    P-type SnS compound and SnS1-xSex solid solutions were prepared by mechanical alloying followed by spark plasma sintering (SPS) and their thermoelectric properties were then studied in different compositions (x = 0.0, 0.2, 0.5, 0.8) along the directions parallel (//) and perpendicular (⊥) to the SPS-pressurizing direction in the temperature range 323-823 Κ. SnS compound and SnS1-xSex solid solutions exhibited anisotropic thermoelectric performance and showed higher power factor and thermal conductivity along the direction ⊥ than the // one. The thermal conductivity decreased with increasing contents of Se and fell to 0.36 W m(-1) K(-1) at 823 K for the composition SnS0.5Se0.5. With increasing selenium content (x) the formation of solid solutions substantially improved the electrical conductivity due to the increased carrier concentration. Hence, the optimized power factor and reduced thermal conductivity resulted in a maximum ZT value of 0.64 at 823 K for SnS0.2Se0.8 along the parallel direction.

  15. Synthesis of Ag2O and Ag co-modified flower-like SnS2 composites with enhanced photocatalytic activity under solar light irradiation

    NASA Astrophysics Data System (ADS)

    Deng, Lu; Zhu, Zhenfeng; Liu, Liu; Liu, Hui

    2017-01-01

    Three-dimensional Ag2O and Ag co-modified flower-like SnS2 composites have been synthesized through a facile hydrothermal and photoreduction process. The physical and chemical properties of Ag2O and Ag co-modified flower-like SnS2 composites were carefully studied by using XRD, SEM, TEM, UV-vis diffuse reflectance spectra (DRS) and XPS. The photocatalytic activity of the as-prepared products was evaluated by photocatalytic decolorization of Rhodamine B (Rh B) aqueous solution at ambient temperature under solar light irradiation. The photocatalytic result shows that Ag2O and Ag co-modified flower-like SnS2 composites exhibit enhanced photocatalytic activity compared with that of pure SnS2. Three of the Ag2O and Ag co-modified flower-like SnS2 composites form the Z-scheme systems, because of their unique charge-carrier transfer process, the oxidation/reduction ability of photogenerated holes and electrons could be enhanced. Therefore, the new Ag2O and Ag co-modified flower-like SnS2 composites possess a favorable photocatalytic activity, and it can be a promising candidate for the solar energy conversion process.

  16. Obstacle course: users' maneuverability and movement efficiency when using Otto Bock C-Leg, Otto Bock 3R60, and CaTech SNS prosthetic knee joints.

    PubMed

    Meier, Margrit R; Hansen, Andrew H; Gard, Steven A; McFadyen, Angus K

    2012-01-01

    The performance and movement efficiency of prosthesis users while traversing a multisectional obstacle course (OC) were evaluated using a crossover design with random allocation of three prosthetic knee joints: the SNS (CaTech; Dayton, Ohio) the C-Leg (Otto Bock; Duderstadt, Germany), and the 3R60 (Otto Bock). Twelve users completed the OC twice with each joint, once without and once with a mental loading task (MLT). The performance was objectively assessed using time measurement from digital video recordings, and the Total Heart Beat Index was used to estimate movement efficiency. A 1 mo familiarization period was provided for each knee joint before data collection. It took longer to complete the OC with the 3R60 compared with either the SNS or the C-Leg. No significant time differences were found between the C-Leg and the SNS, but differences between the 3R60 and the SNS (slalom and rock sections) and between the 3R60 and the C-Leg (rock section) were observed. Within the simulated sand section, two participants fell with the C-Leg, one with the 3R60, and none with the SNS. Movement efficiency without MLT was similar between all joints, but with an MLT a significant decrease in movement efficiency was observed with the C-Leg. Previous experience using an SNS had no influence on the results.

  17. Thermoelectric SnS and SnS-SnSe solid solutions prepared by mechanical alloying and spark plasma sintering: Anisotropic thermoelectric properties

    NASA Astrophysics Data System (ADS)

    Asfandiyar; Wei, Tian-Ran; Li, Zhiliang; Sun, Fu-Hua; Pan, Yu; Wu, Chao-Feng; Farooq, Muhammad Umer; Tang, Huaichao; Li, Fu; Li, Bo; Li, Jing-Feng

    2017-02-01

    P–type SnS compound and SnS1‑xSex solid solutions were prepared by mechanical alloying followed by spark plasma sintering (SPS) and their thermoelectric properties were then studied in different compositions (x = 0.0, 0.2, 0.5, 0.8) along the directions parallel (//) and perpendicular (⊥) to the SPS–pressurizing direction in the temperature range 323–823 Κ. SnS compound and SnS1‑xSex solid solutions exhibited anisotropic thermoelectric performance and showed higher power factor and thermal conductivity along the direction ⊥ than the // one. The thermal conductivity decreased with increasing contents of Se and fell to 0.36 W m‑1 K‑1 at 823 K for the composition SnS0.5Se0.5. With increasing selenium content (x) the formation of solid solutions substantially improved the electrical conductivity due to the increased carrier concentration. Hence, the optimized power factor and reduced thermal conductivity resulted in a maximum ZT value of 0.64 at 823 K for SnS0.2Se0.8 along the parallel direction.

  18. Efficient electron transfer kuramite Cu3SnS4 nanosheet thin film towards platinum-free cathode in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Chen, Shan-Long; Tao, Jie; Shu, Hai-Bo; Tao, Hai-Jun; Tang, Yu-Xin; Shen, Yi-Zhou; Wang, Tao; Pan, Lei

    2017-02-01

    The density-functional theory calculations in this work clearly revealed that the kuramite-structure Cu3SnS4 material possessing the metallic characteristic, result in the higher charge transfer between I3- ions and the Cu3SnS4 surfaces, and the rapid redox transfer reaction of I3-/I- in dye-sensitized solar cells system. Then, a feasible and mild solution method was proposed to in-situ synthesize Cu-rich kuramite-structure Cu3SnS4 thin film on FTO substrate, and the acquired thin film was used directly as counter electrode to assemble dye-sensitized solar cells without any post-treatments. The obtained-Cu3SnS4 nanosheet film had good bonding strength, expanded surface area, low photoelectron charge transfer resistance at the counter electrode/electrolyte interface, and great catalytic activity toward the reduction of I3-/I- ions. Power conversion efficiency of 7.80% was obtained by utilizing Cu3SnS4 nanosheet as counter electrode, which was superior to that of Pt electrode (6.52%). Our results demonstrate the earth-abundant and low-cost kuramite Cu3SnS4 is an alternative Pt-free counter electrode material in dye-sensitized solar cells.

  19. Preparation of SnS2 colloidal quantum dots and their application in organic/inorganic hybrid solar cells

    PubMed Central

    2011-01-01

    Dispersive SnS2 colloidal quantum dots have been synthesized via hot-injection method. Hybrid photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3",7"dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline SnS2 quantum dots as electron acceptor have been studied. Photoluminescence measurement has been performed to study the surfactant effect on the excitons splitting process. The photocurrent of solar cells with the hybrid depends greatly on the ligands exchange as well as the device heat treatment. AFM characterization has demonstrated morphology changes happening upon surfactant replacement and annealing, which can explain the performance variation of hybrid solar cells. PMID:21711811

  20. Band alignment in SnS thin-film solar cells: Possible origin of the low conversion efficiency

    NASA Astrophysics Data System (ADS)

    Burton, Lee A.; Walsh, Aron

    2013-04-01

    Tin sulfide is an attractive absorber material for low-cost thin-film solar cells. Despite the ideal physical properties of bulk SnS, the photovoltaic conversion efficiencies achieved in devices to date have been no greater than 2%. Assessment of the valence band energy of the stable orthorhombic phase of SnS reveals a low ionisation potential (4.7 eV) in comparison to typical absorber materials (CdTe, CuInSe2, and Cu2ZnSnS4). A band mis-alignment is therefore predicted with commonly used back contact and buffer layers. Alternative configurations are proposed that should improve device performance.

  1. Tuning electronic structure of SnS2 nanosheets by vertical electric field: a first-principles investigation

    NASA Astrophysics Data System (ADS)

    Guo, Peng; Wang, Tianxing; Xia, Congxin; Jia, Yu

    2016-07-01

    Based on density functional theory, we investigated band gap tuning in transition-metal dichalcogenides SnS2 nanosheets by external electric fields applied perpendicular to the layers. We show that the fundamental band gap value of 2H and 4H SnS2 multilayer structures continuously decreases with increasing strength of applied electric fields, eventually rendering them metallic. We interpret our results in the light of the giant Stark effect and obtain a robust relationship, which is essentially characterized by the interlayer spacing, for the rate of band gap change with applied external field. And it is also valid for monolayer structure, though it need very large electric filed to make the gap change.

  2. HVCM Topology Enhancements to Support a Power Upgrade Required by a Second Target Station (STS) at SNS

    SciTech Connect

    Solley, Dennis J; Anderson, David E; Patel, Gunjan P; Peplov, Vladimir V; Saethre, Robert B; Wezensky, Mark W

    2012-01-01

    This paper discusses the topology used in the HVCMs at SNS to process power for both the cold and warm linac sections of the klystron gallery in support of extended operations at the megawatt level. In anticipation of a second target station and higher anticipated power levels, an enhancement to the present topology is being investigated. SPICE circuit simulations and preliminary experimental data will be presented.

  3. n-type conversion of SnS by isovalent ion substitution: Geometrical doping as a new doping route

    PubMed Central

    Ran, Fan-Yong; Xiao, Zewen; Toda, Yoshitake; Hiramatsu, Hidenori; Hosono, Hideo; Kamiya, Toshio

    2015-01-01

    Tin monosulfide (SnS) is a naturally p-type semiconductor with a layered crystal structure, but no reliable n-type SnS has been obtained by conventional aliovalent ion substitution. In this work, carrier polarity conversion to n-type was achieved by isovalent ion substitution for polycrystalline SnS thin films on glass substrates. Substituting Pb2+ for Sn2+ converted the majority carrier from hole to electron, and the free electron density ranged from 1012 to 1015 cm−3 with the largest electron mobility of 7.0 cm2/(Vs). The n-type conduction was confirmed further by the position of the Fermi level (EF) based on photoemission spectroscopy and electrical characteristics of pn heterojunctions. Density functional theory calculations reveal that the Pb substitution invokes a geometrical size effect that enlarges the interlayer distance and subsequently reduces the formation energies of Sn and Pb interstitials, which results in the electron doping. PMID:26020855

  4. Surface functionalized Cu2Zn1- x Cd x SnS4 quinternary alloyed nanostructure for DNA sensing

    NASA Astrophysics Data System (ADS)

    Ibraheam, A. S.; Al-Douri, Y.; Voon, C. H.; Foo, K. L.; Azizah, N.; Gopinath, S. C. B.; Ameri, M.; Ibrahim, Sattar S.

    2017-03-01

    A sensing plate of extended Cu2Zn1- x Cd x SnS4 quinternary alloy nanostructures, fabricated on an oxidized silicon substrate by the sol-gel method, is reported in this paper. The fabricated device was characterized and analyzed via field emission-scanning electron microscopy, X-ray diffraction (XRD), and photoluminescence (PL). The XRD peaks shifted towards the lower angle side alongside increasing concentration of cadmium. The average diameter of the Cu2Zn1- x Cd x SnS4 quinternary alloy nanostructures falls between 21.55 and 43.12 nm, while the shift of the PL bandgap was from 1.81 eV ( x = 0) to 1.72 eV ( x = 1). The resulting Cu2Zn1- x Cd x SnS4 quinternary alloy nanostructures components were functionalized with oligonucleotides probe DNA molecules and interacted with the target, exhibiting good sensing capabilities due to its large surface-to-volume ratio. The fabrication, immobilization, and hybridization processes were analyzed via representative current-voltage ( I- V) plots. Its electrical profile shows that the device is capable to distinguish biomolecules. Its high performance was evident from the linear relationship between the probe DNA from cervical cancer and the target DNA, showing its applicability for medical applications.

  5. Progress on Study of Electric Breakdown in Superfluid Liquid Helium for the SNS nEDM Experiment

    NASA Astrophysics Data System (ADS)

    Wei, Wanchun; Beck, Douglas; Bouman, Nathaniel; Cianciolo, Vince; Clayton, Steven; Crawford, Christopher; Currie, Scott; Griffith, William; Ito, Takeyasu; Ramsey, John; Schmid, Richardo; Seidel, George; Stanislaus, Shirvel; Tang, Zhaowen; Wagner, Daniel; Williamson, Steven; Yao, Weijun; SNS nEDM Collaboration

    2016-09-01

    The SNS nEDM collaboration is developing an experiment to search for the neutron's electric dipole moment (EDM) to be run at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. As the experimental sensitivity depends linearly on the strength of applied electric field, it is of critical importance to achieve a strong and stable electric field in the storage region of ultracold neutrons (UCN) in superfluid helium. However, the phenomenon of electric breakdown in liquid helium is poorly understood, and as such a major R&D effort is under way. We have developed an apparatus to test various coating materials on electrodes of 12 cm diameter and study breakdown in liquid helium at temperatures as low as 0.4 K and pressures between saturated vapor pressure and 1 atm. Meanwhile, a small test apparatus has been used to study various aspects of breakdown phenomenon. In this talk, the present status of our effort, implication of findings on the SNS nEDM experiment and future plans will be presented.

  6. Evaluation of SNS Beamline Shielding Configurations using MCNPX Accelerated by ADVANTG

    SciTech Connect

    Risner, Joel M; Johnson, Seth R.; Remec, Igor; Bekar, Kursat B.

    2015-01-01

    Shielding analyses for the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory pose significant computational challenges, including highly anisotropic high-energy sources, a combination of deep penetration shielding and an unshielded beamline, and a desire to obtain well-converged nearly global solutions for mapping of predicted radiation fields. The majority of these analyses have been performed using MCNPX with manually generated variance reduction parameters (source biasing and cell-based splitting and Russian roulette) that were largely based on the analyst's insight into the problem specifics. Development of the variance reduction parameters required extensive analyst time, and was often tailored to specific portions of the model phase space. We previously applied a developmental version of the ADVANTG code to an SNS beamline study to perform a hybrid deterministic/Monte Carlo analysis and showed that we could obtain nearly global Monte Carlo solutions with essentially uniform relative errors for mesh tallies that cover extensive portions of the model with typical voxel spacing of a few centimeters. The use of weight window maps and consistent biased sources produced using the FW-CADIS methodology in ADVANTG allowed us to obtain these solutions using substantially less computer time than the previous cell-based splitting approach. While those results were promising, the process of using the developmental version of ADVANTG was somewhat laborious, requiring user-developed Python scripts to drive much of the analysis sequence. In addition, limitations imposed by the size of weight-window files in MCNPX necessitated the use of relatively coarse spatial and energy discretization for the deterministic Denovo calculations that we used to generate the variance reduction parameters. We recently applied the production version of ADVANTG to this beamline analysis, which substantially streamlined the analysis process. We also tested importance function

  7. 'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 3: Anti-Yo/CDR2, anti-Nb/AP3B2, PCA-2, anti-Tr/DNER, other antibodies, diagnostic pitfalls, summary and outlook.

    PubMed

    Jarius, S; Wildemann, B

    2015-09-17

    Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.

  8. Integrated modeling/analyses of thermal-shock effects in SNS targets

    SciTech Connect

    Taleyarkhan, R.P.; Haines, J.

    1996-06-01

    In a spallation neutron source (SNS), extremely rapid energy pulses are introduced in target materials such as mercury, lead, tungsten, uranium, etc. Shock phenomena in such systems may possibly lead to structural material damage beyond the design basis. As expected, the progression of shock waves and interaction with surrounding materials for liquid targets can be quite different from that in solid targets. The purpose of this paper is to describe ORNL`s modeling framework for `integrated` assessment of thermal-shock issues in liquid and solid target designs. This modeling framework is being developed based upon expertise developed from past reactor safety studies, especially those related to the Advanced Neutron Source (ANS) Project. Unlike previous separate-effects modeling approaches employed (for evaluating target behavior when subjected to thermal shocks), the present approach treats the overall problem in a coupled manner using state-of-the-art equations of state for materials of interest (viz., mercury, tungsten and uranium). That is, the modeling framework simultaneously accounts for localized (and distributed) compression pressure pulse generation due to transient heat deposition, the transport of this shock wave outwards, interaction with surrounding boundaries, feedback to mercury from structures, multi-dimensional reflection patterns & stress induced (possible) breakup or fracture.

  9. Transport of polarized 3He for the nEDM experiment at the SNS

    NASA Astrophysics Data System (ADS)

    Rao, Thomas; Beck, Douglas; Koivuniemi, Jaakko; Silvera, Ike; Williamson, Steven; Yao, Weijun; nEDM Collaboration

    2016-09-01

    The neutron electric dipole moment (nEDM) experiment at the ORNL SNS aims to determine the neutron's electric dipole moment to an accuracy of 5.4 x 10-28 e cm by measuring the Lamor precession of neutrons using the spin dependent reaction n +3He =>p +3H +764KeV. In the experiment polarized 3He is injected into a free surface of 4He, and then brought to the measurement cell and removed once it depolarizes. The proposed transport method for the 3He, the heat flush mechanism, must be tested. In the heat flush mechanism a thermal gradient along a long pipe, generates phonons whose collisions with 3He, drives 3He transport to the cold end of the pipe. Tests of the heat flush mechanism by measuring the change in 3He concentration at the cold end of a long pipe, using a capacitive pressure sensor, are underway at Harvard University. Work supported in part by NSF Grants PHY-1440011 and PHY-1506416.

  10. Josephson current in finite-lenght nanowire SNS junctions with Majorana fermions

    NASA Astrophysics Data System (ADS)

    Aguado, Ramon; Prada, Elsa; San Jose, Pablo

    2012-02-01

    The dc Josephson effect (JE) through infinite-lenght junctions of one-dimensional topological superconductors exhibits an anomalous 4π periodic phase (φ) dependence which originates from a parity-protected level crossing of zero-energy Majorana bound states (MBS) at φ=π. This ``fractional'' JE provides an important experimental detection tool for MBS. In this talk, I will discuss the JE in more realistic SNS junctions of arbitrary transparency and when both the normal and the nanowire regions are of finite length, namely beyond the short-junction and infinite topological superconductor limits. In general, the spectrum of Andreev bound states can become rather intricate and dense as opposed to the infinite-lenght case. Moreover, the low-energy spectrum around φ=π shows always anticrossings, originated from hybridization of four MBS, which may preclude the experimental observation of the fractional JE. At finite bias voltages, Landau-Zener dynamics involving the MBS and quasi-continuum Andreev levels gives rise to a nontrivial ac Josephson current. Interestingly, the ac current phase diagram as a function of the Josephson frequency/normal transmission shows fractional JE regions which are tunable through bias/gate voltages.

  11. Circuit theory of multiple Andreev reflections in diffusive SNS junctions: The incoherent case

    NASA Astrophysics Data System (ADS)

    Bezuglyi, E. V.; Bratus', E. N.; Shumeiko, V. S.; Wendin, G.; Takayanagi, H.

    2000-12-01

    The incoherent regime of multiple Andreev reflections (MAR) is studied in long diffusive SNS junctions at applied voltages larger than the Thouless energy. Incoherent MAR are treated as a transport problem in energy space by means of a circuit theory for an equivalent electrical network. The current through NS interfaces is explained in terms of diffusion flows of electrons and holes through ``tunnel'' and ``Andreev'' resistors. These resistors in diffusive junctions play roles analogous to the normal and Andreev reflection coefficients in Octavio-Tinkham-Blonder-Klapwijk theory for ballistic junctions. The theory is applied to the subharmonic gap structure (SGS); simple analytical results are obtained for the distribution function and current spectral density for the limiting cases of resistive and transparent NS interfaces. In the general case, the exact solution is found in terms of chain fractions, and the current is calculated numerically. SGS shows qualitatively different behavior for even and odd subharmonic numbers n=2Δ/eV, and the maximum slopes of the differential resistance correspond to the gap subharmonics, eV=2Δ/n. The influence of inelastic scattering on the subgap anomalies of the differential resistance is analyzed.

  12. Cu2SnS3 nanostructures for inorganic-organic hybrid infrared photodetector applications

    NASA Astrophysics Data System (ADS)

    Dias, Sandra; Krupanidhi, S. B.

    2016-10-01

    Cu2SnS3 (CTS) nanostructures were synthesized using the solvothermal method and used in a CTS-polymer inorganic-organic hybrid device to study the enhancement in the infrared (IR) photoresponse. The structural and optical properties of the CTS nanostructures were measured. The IR photoresponse was measured for both the P3HT-PCBM polymer blend and various concentrations of CTS in P3HT-PCBM. The responsivity, sensitivity, external quantum efficiency and specific detectivity were found to be 19.4 mA W-1, 1.4, 3.01% and 7.97 × 108 Jones respectively for the P3HT:PCBM = 1:1 sample and 211.5 mA W-1, 3.6, 32.8% and 8.7 × 109 Jones respectively for CTS:P3HT:PCBM = 12:1:1 sample at 1 V bias and 477.7 mW cm-2 IR illumination intensity. The photoresponse was also measured under 1550 nm laser illumination of 1100 mW cm-2 intensity. The time dependent photoresponse showed good cyclic stability over time for different ON-OFF cycles. CTS nanostructures prove to be beneficial in enhancing the photoresponse of the IR photodetector device.

  13. Experimental Results Obtained with Air Liquide Cold Compression System: CERN LHC and SNS Projects

    NASA Astrophysics Data System (ADS)

    Delcayre, F.; Courty, J.-C.; Hamber, F.; Hilbert, B.; Monneret, E.; Toia, J.-L.

    2006-04-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high-capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC will be detailed. The principles of control for the CCC in series will be detailed.

  14. Hypothalamic ΔFosB prevents age-related metabolic decline and functions via SNS

    PubMed Central

    Nagano, Kenichi; Rowe, Glenn C.; Gori, Francesca; Baron, Roland

    2017-01-01

    The ventral hypothalamus (VHT) integrates several physiological cues to maintain glucose homeostasis and energy balance. Aging is associated with increased glucose intolerance but the underlying mechanisms responsible for age-related metabolic decline, including neuronal signaling in the VHT, remain elusive. We have shown that mice with VHT-targeted overexpression of ΔFosB, a splice variant of the AP1 transcription factor FosB, exhibit increased energy expenditure, leading to decreased adiposity. Here, we show that VHT-targeted overexpression of ΔFosB also improves glucose tolerance, increases insulin sensitivity in target organs and thereby suppresses insulin secretion. These effects are also observed by the overexpression of dominant negative JunD, demonstrating that they occur via AP1 antagonism within the VHT. Furthermore, the improved glucose tolerance and insulin sensitivity persisted in aged animals overexpressing ΔFosB in the VHT. These beneficial effects on glucose metabolism were abolished by peripheral sympathectomy and α-adrenergic, but not β-adrenergic, blockade. Taken together, our results show that antagonizing AP1 transcription activity in the VHT leads to a marked improvement in whole body glucose homeostasis via activation of the SNS, conferring protection against age-related impairment in glucose metabolism. These findings may open novel avenues for therapeutic intervention in diabetes and age-related glucose intolerance. PMID:28121620

  15. The Nanoscale Ordered MAterials Diffractometer NOMAD at the Spallation Neutron Source SNS

    NASA Astrophysics Data System (ADS)

    Neuefeind, Jörg; Feygenson, Mikhail; Carruth, John; Hoffmann, Ron; Chipley, Kenneth K.

    2012-09-01

    The Nanoscale Ordered MAterials Diffractometer (NOMAD) is neutron time-of-flight diffractometer designed to determine pair distribution functions of a wide range of materials ranging from short range ordered liquids to long range ordered crystals. Due to a large neutron flux provided by the Spallation Neutron Source SNS and a large detector coverage neutron count-rates exceed comparable instruments by one to two orders of magnitude. This is achieved while maintaining a relatively high momentum transfer resolution of a δQ/Q ˜0.8% FWHM (typical), and a possible δQ/Q of 0.24% FWHM (best). The real space resolution is related to the maximum momentum transfer; a maximum momentum transfer of 50 Å-1 can be obtained routinely and the maximum momentum transfer given by the detector configuration and the incident neutron spectrum is 125 Å. High stability of the source and the detector allow small contrast isotope experiments to be performed. A detailed description of the instrument is given and the results of experiments with standard samples are discussed.

  16. Recent performance and ignition tests of the pulsed SNS H- source for 1-MW neutron production

    NASA Astrophysics Data System (ADS)

    Stockli, Martin P.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R. F.

    2015-04-01

    After acquiring several reliable spare targets, SNS ramped the beam power from 850 kW to 1.4 MW, which required an increase in H- beam pulse length from 0.88 to 1.0 ms at 60 Hz. This increase initially produced slow 2-MHz power ramp-ups and, after several weeks of uninterrupted operation, it produced plasma outages every time the pulse length was raised above ˜0.95 ms. Similar outages were previously observed towards the end of long service cycles, which were believed to indicate that the breakdown voltage of the high purity hydrogen started to exceed the induced electric fields. In 2011 the RF was reconfigured to start with 10 cycles of 1.96 MHz, which yielded the shortest H- beam rise times and apparently eliminated those plasma outages. The new, pulse-length dependent outages were eliminated by increasing the initial frequency to 1.985 MHz. However, careful frequency studies are unable to justify this frequency. In addition, the paper discusses the issues and solutions for the electron-dump voltage, which starts to sag and become unstable after several weeks of high current operation. At the request of the authors and the Proceedings Editor this article has been updated to include References 3-13, which were present in the author's original submission but were lost during manuscript processing in the Proceedings Editor's office. The updated article was published on 5 May 2015.

  17. Gamma Dose Calculations in the Target Service Cell of the SNS

    SciTech Connect

    Azmy, Y.Y.; Johnson, J.O.; Lillie, R.A.; Santoro, R.T.

    1999-11-14

    Calculations of the gamma dose rates inside and outside of the Target Service Cell (TSC) of the Spallation Neutron Source (SNS) are complicated by the large size of the structure, large volume of air (internal void), optical thickness of the enclosing walls, and multiplicity of radiation sources. Furthermore, a reasonably detailed distribution of the dose rate over the volume of the TSC, and on the outside of its walls is necessary in order to optimize electronic instrument locations, and plan access control. For all these reasons a deterministic transport method was preferred over Monte Carlo, The three- dimensional neutral particle transport code TORT was employed for this purpose with support from other peripheral codes in the Discrete Ordinates of Oak Ridge System (DOORS). The computational model for the TSC is described and the features of TORT and its companion codes that enable such a difficult calculation are discussed. Most prominent is the presence of severe ray effects in the air cavity of the TSC that persists in the transport through the concrete walls and is pronounced throughout the problem volume. Initial attempts at eliminating ray effects from the computed results using the newly developed three-dimensional uncollided flux and first collided source code GRTUNCL3D are described.

  18. Control System for the SNS H- Source Test Stand Allison Scanner

    SciTech Connect

    Long, Cary D; Stockli, Martin P; Gorlov, Timofey V; Han, Baoxi; Pennisi, Terry R; Murray Jr, S N

    2010-01-01

    SNS is currently in progress of a multi-year plan to ramp ion beam power to the initial design power of 1.4 MW. Key to reaching this goal is understanding and improving the operation of the H- ion source. An Allison scanner was installed on the ion source test stand to support this improvement. This paper will discuss the hardware and the software control system of the installed Allison scanner. The hardware for the system consists of several parts. The heart of the system is the scanner head, complete with associated bias plates, slits, and signal detector. There are two analog controlled high voltage power supplies to bias the plates in the head, and a motor with associated controller to position the head in the beam. A multifunction data acquisition card reads the signals from the signal detector, as well as supplying the analog voltage control for the power supplies. To synchronize data acquisition with the source, the same timing signal that is used to trigger the source itself is used to trigger data acquisition. Finally, there is an industrial PC to control the rest of the hardware. Control software was developed using National Instruments LabVIEW, and consists of two parts, a data acquisition program to control the hardware, and a stand alone application for offline user data analysis.

  19. Exciton luminescence from Cu2SnS3 bulk crystals

    NASA Astrophysics Data System (ADS)

    Aihara, Naoya; Matsumoto, Yusuke; Tanaka, Kunihiko

    2016-02-01

    The optical properties of Cu2SnS3 (CTS) bulk crystals grown by chemical vapor transport were studied by photoluminescence (PL) spectroscopy. The PL spectra from the CTS bulk crystals were analyzed as a function of excitation power and temperature. The main phase of the as-grown samples was determined to be monoclinic CTS by Raman spectroscopy. The observed PL spectra from the CTS bulk crystals were composed of peaks corresponding to free-exciton, two bound-excitons, and donor-acceptor pair recombination luminescence. The peak energies for the free-exciton and two bound-exciton emissions were 0.9317, 0.9291, and 0.9260 eV, respectively, at temperature of 4.2 K. The bound-exciton luminescence was not observed above 30 K. The thermal activation energies for the free-exciton and two bound-exciton emissions were 6.5, 4.8, and 5.2 meV, respectively. The fundamental band gap in the CTS bulk crystals was expected to be ca. 0.94 eV.

  20. Synthesis of Earth-abundant Cu2SnS3 for Solar Cells

    NASA Astrophysics Data System (ADS)

    Tiwari, D.; Chaudhuri, T. K.

    2011-07-01

    Cu2SnS3 (CTS) is an emerging semiconducting absorber layer material for solar cells having energy band gap of around 1 eV. In this work CTS powders has been synthesized from metal salts using different sulphur sources. It is found that thiourea yielded pure CTS. The composition of the prepared material has been confirmed by X-ray diffraction (XRD), which shows the CTS powder to be nanocrystalline with triclinic phase. Also the time of the completion of reaction has been optimized by studying the XRD pattern of the product at different time interval of reaction. The diffuse reflectance spectrum of CTS depicts the energy band gap for the sample to be 1.1 eV. The electrical measurement of the pellet of the CTS powders proves the material to have p-type conduction with thermoelectric coefficient of 95μV/K as determined from hot-probe method. The electrical conductivity of the pellet is 10-32 mho/cm.

  1. Recent performance of the SNS H- ion source and low-energy beam transport system

    NASA Astrophysics Data System (ADS)

    Stockli, Martin P.; Ewald, K. D.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Tang, J.; Welton, R.

    2014-02-01

    Recent measurements of the H- beam current show that SNS is injecting about 55 mA into the RFQ compared to ˜45 mA in 2010. Since 2010, the H- beam exiting the RFQ dropped from ˜40 mA to ˜34 mA, which is sufficient for 1 MW of beam power. To minimize the impact of the RFQ degradation, the service cycle of the best performing source was extended to 6 weeks. The only degradation is fluctuations in the electron dump voltage towards the end of some service cycles, a problem that is being investigated. Very recently, the RFQ was retuned, which partly restored its transmission. In addition, the electrostatic low-energy beam transport system was reengineered to double its heat sinking and equipped with a thermocouple that monitors the temperature of the ground electrode between the two Einzel lenses. The recorded data show that emissions from the source at high voltage dominate the heat load. Emissions from the partly Cs-covered first lens cause the temperature to peak several hours after starting up. On rare occasions, the temperature can also peak due to corona discharges between the center ground electrode and one of the lenses.

  2. Recent performance of the SNS H(-) ion source and low-energy beam transport system.

    PubMed

    Stockli, Martin P; Ewald, K D; Han, B X; Murray, S N; Pennisi, T R; Piller, C; Santana, M; Tang, J; Welton, R

    2014-02-01

    Recent measurements of the H(-) beam current show that SNS is injecting about 55 mA into the RFQ compared to ∼45 mA in 2010. Since 2010, the H(-) beam exiting the RFQ dropped from ∼40 mA to ∼34 mA, which is sufficient for 1 MW of beam power. To minimize the impact of the RFQ degradation, the service cycle of the best performing source was extended to 6 weeks. The only degradation is fluctuations in the electron dump voltage towards the end of some service cycles, a problem that is being investigated. Very recently, the RFQ was retuned, which partly restored its transmission. In addition, the electrostatic low-energy beam transport system was reengineered to double its heat sinking and equipped with a thermocouple that monitors the temperature of the ground electrode between the two Einzel lenses. The recorded data show that emissions from the source at high voltage dominate the heat load. Emissions from the partly Cs-covered first lens cause the temperature to peak several hours after starting up. On rare occasions, the temperature can also peak due to corona discharges between the center ground electrode and one of the lenses.

  3. Plasma emission spectroscopy for operating and developing the Spallation Neutron Source (SNS) H- ion sources

    SciTech Connect

    Han, Baoxi; Welton, Robert F; Murray Jr, S N; Pennisi, Terry R; Santana, Manuel; Stockli, Martin P

    2014-01-01

    An RF-driven, Cs-enhanced H- ion source feeds the SNS accelerator with a high current (typically >50 mA), ~1.0 ms pulsed beam at 60 Hz. To achieve the persistent high current beam for several weeks long service cycles, each newly installed ion source undergoes a rigorous conditioning and cesiation processes. Plasma conditioning outgases the system and sputter-cleans the ion conversion surfaces. A cesiation process immediately following the plasma conditioning releases Cs to provide coverage on the ion conversion surfaces. The effectiveness of the ion source conditioning and cesiation is monitored with plasma emission spectroscopy using a high-sensitivity optical spectrometer. Plasma emission spectroscopy is also used to provide a mean for diagnosing and confirming a failure of the insulating coating of the ion source RF antenna which is immersed in the plasma. Emissions of composition elements of the antenna coating material, Na emission being the most significant, drastically elevate to signal a failure when it happens. Plasma spectra of the developmental ion source with an AlN chamber and an external RF antenna are also briefly discussed.

  4. Recent Performance and Ignition Tests of the pulsed SNS H- Source for 1-MW Neutron Production

    SciTech Connect

    Stockli, Martin P; Han, Baoxi; Murray, Jr, S N; Pennisi, Terry R; Piller, Chip; Santana, Manuel; Welton, Robert F

    2015-01-01

    After acquiring several reliable spare targets, SNS ramped the beam power from 850 kW to 1.4 MW, which required an increase in H- beam pulse length from 0.88 to 1.0 ms at 60 Hz. This increase initially produced slow 2-MHz power ramp-ups and, after several weeks of uninterrupted operation, it produced plasma outages every time the pulse length was raised above ~0.95 ms. Similar outages were previously observed towards the end of long service cycles, which were believed to indicate that the breakdown voltage of the high purity hydrogen started to exceed the induced electric fields. In 2011 the RF was reconfigured to start with 10 cycles of 1.96 MHz, which yielded the shortest H- beam rise times and apparently eliminated those plasma outages. The new, pulse-length dependent outages were eliminated by increasing the initial frequency to 1.985 MHz. However, careful frequency studies are unable to justify this frequency. In addition, the paper discusses the issues and solutions for the electron-dump voltage, which starts to sag and become unstable after several weeks of high current operation.

  5. Non-monotonic effect of growth temperature on carrier collection in SnS solar cells

    SciTech Connect

    Chakraborty, R.; Steinmann, V.; Mangan, N. M.; Brandt, R. E.; Poindexter, J. R.; Jaramillo, R.; Mailoa, J. P.; Hartman, K.; Polizzotti, A.; Buonassisi, T.; Yang, C.; Gordon, R. G.

    2015-05-18

    We quantify the effects of growth temperature on material and device properties of thermally evaporated SnS thin-films and test structures. Grain size, Hall mobility, and majority-carrier concentration monotonically increase with growth temperature. However, the charge collection as measured by the long-wavelength contribution to short-circuit current exhibits a non-monotonic behavior: the collection decreases with increased growth temperature from 150 °C to 240 °C and then recovers at 285 °C. Fits to the experimental internal quantum efficiency using an opto-electronic model indicate that the non-monotonic behavior of charge-carrier collection can be explained by a transition from drift- to diffusion-assisted components of carrier collection. The results show a promising increase in the extracted minority-carrier diffusion length at the highest growth temperature of 285 °C. These findings illustrate how coupled mechanisms can affect early stage device development, highlighting the critical role of direct materials property measurements and simulation.

  6. A NEW DIFFERENTIAL AND ERRANT BEAM CURRENT MONITOR FOR THE SNS* ACCELERATOR

    SciTech Connect

    Blokland, Willem; Peters, Charles C

    2013-01-01

    A new Differential and errant Beam Current Monitor (DBCM) is being implemented for both the Spallation Neutron Source's Medium Energy Beam Transport (MEBT) and the Super Conducting Linac (SCL) accelerator sections. These new current monitors will abort the beam when the difference between two toroidal pickups exceeds a threshold. The MEBT DBCM will protect the MEBT chopper target, while the SCL DBCM will abort beam to minimize fast beam losses in the SCL cavities. The new DBCM will also record instances of errant beam, such as beam dropouts, to assist in further optimization of the SNS Accelerator. A software Errant Beam Monitor was implemented on the regular BCM hardware to study errant beam pulses. The new system will take over this functionality and will also be able to abort beam on pulse-to-pulse variations. Because the system is based on the FlexRIO hardware and programmed in LabVIEW FPGA, it will be able to abort beam in about 5 us. This paper describes the development, implementation, and initial test results of the DBCM, as well as errant beam examples.

  7. Josephson critical current of long SNS junctions in the presence of a magnetic field

    NASA Astrophysics Data System (ADS)

    Meier, Hendrik; Fal'Ko, Vladimir I.; Glazman, Leonid I.

    We evaluate the Josephson critical current of a long and wide two-dimensional superconductor-normal metal-superconductor (SNS) junction, taking into account the effect of electron reflection off the side edges of the junction. Considering clean junctions, we find that the effect of edges alters the usual Fraunhofer-like dependence of the Josephson critical current Ic on the magnetic flux Φ. At relatively weak fields, B <~Φ0 /W2 , the edge effect lifts zeros of the Ic (Φ) dependence and gradually shifts the maxima of that function by Φ0 / 2 . (Here W is the width of the junction and Φ0 the magnetic flux quantum.) At higher fields, B >~Φ0 /W2 , the edge effect leads to an accelerated decay of the critical current Ic (Φ) with increasing Φ. Our results are robust with respect to the roughness of realistic boundaries. Finally, we discuss the role of mesoscopic fluctuations of Ic (Φ) originating from the scattering off the edges, and compare our findings to recent experiments.

  8. Recent Performance of the SNS H- ion source and low-energy beam transport system

    SciTech Connect

    Stockli, Martin P; Ewald, Kerry D; Han, Baoxi; Murray Jr, S N; Pennisi, Terry R; Piller, Chip; Santana, Manuel; Tang, Johnny Y; Welton, Robert F

    2014-01-01

    Recent measurements of the H beam current show that SNS is injecting about 55 mA into the RFQ compared to 45 mA in 2010. Since 2010, the H beam exiting the RFQ dropped from 40 mA to 34 mA, which is sufficient for 1 MW of beam power. To minimize the impact of the RFQ degradation, the service cycle of the best performing source was extended to 6 weeks. The only degradation is fluctuations in the electron dump voltage towards the end of some service cycles, a problem that is being investigated. Very recently, the RFQ was retuned, which partly restored its transmission. In addition, the electrostatic low-energy beam transport system was reengineered to double its heat sinking and equipped with a thermocouple that monitors the temperature of the ground electrode between the two Einzel lenses. The recorded data show that emissions from the source at high voltage dominate the heat load. Emissions from the partly Cs-covered first lens cause the temperature to peak several hours after starting up. On rare occasions, the temperature can also peak due to corona discharges between the center ground electrode and one of the lenses.

  9. Fabrication and sulfurization of Cu2SnS3 thin films with tuning the concentration of Cu-Sn-S precursor ink

    NASA Astrophysics Data System (ADS)

    Wang, Chi-Jie; Shei, Shih-Chang; Chang, Shih-Chang; Chang, Shoou-Jinn

    2016-12-01

    In this study, Cu-Sn-S nanoinks were synthesized by combining chelating polyetheramine to Cu, Sn, S powders of various concentrations. X-ray diffraction patterns indicate that nanoinks synthesized at low concentrations are composed almost entirely of binary phases SnS and Cu2S. Synthesizing nanoinks at higher concentrations decreased the quantity of binary phase and led to the appearance of ternary phase Cu4SnS4. Following sulfurization, single phase Cu2SnS3 (CTS) thin film was obtained from nanoinks of low concentration; however, impurities, such as Cu2S were detected in the thin film obtained from nanoinks of high concentration. This can be attributed to the fact that lower concentrations reduce the reactivity of all the elements. As a result, the SnS phase reacted more readily and more rapidly, resulting in the early formation of a stoichiometric CTS thin film during sulfurization. Under these reaction conditions, Cu2S and SnS transform into CTS and thereby prevent the formation of unwanted phases of Cu2S and Cu4SnS4. Raman spectra revealed that second phase Cu2S phase remained in the high-concentration samples, due to an increase in reactivity due to the participation of a greater proportion of the copper in the reaction. The surface microstructure of low-concentration samples display closely packed Cu2SnS3 grains with a flat morphology and an atomic composition ratio of Cu:Sn:S = 34.69:15.90:49.41, which is close to stoichiometric. Hall measurement revealed that low-concentration sample has superior electrical properties; i.e., a hole concentration of 5.23 × 1017 cm-3, mobility of 14.2 cm2/V-s, and optical band-gap energy of 1.346 eV, which are suitable for thin-film solar cells.

  10. [Diagnostic Management of Exophthalmos].

    PubMed

    Klingenstein, A; Hintschich, C

    2017-01-01

    Exophthalmos is a common and important symptom in orbital consultation. It can be either uni- or bilateral. A wide spectrum of benign and malignant diseases has to be considered and evaluated for differential diagnosis, in order to maintain complete ocular function and to lead the patient to adequate therapy. Exophthalmos can be accompanied by variable symptoms, ranging from neurogenic or myogenic to corneal alterations. Symptoms at presentation depend on the underlying disease and may manifest systemically. Interdisciplinary teamwork is essential for diagnostics and therapy of exophthalmos. In addition to ophthalmological routine diagnostics, various supplementary examinations are available which are of importance for disease monitoring. Exact radiological imaging is important for the detailed visualisation of the pathology, surgery as well as treatment planning. Magnetic resonance imaging (MRI) and computed tomography (CT) are the standard imaging techniques used. Contrast enhancement and specific sequences can answer specific problems in detail. Combined positron emission tomography (PET) with CT permits evaluation of metabolic and morphological data and is employed in diagnosis of meningioma, lymphoma and metastases. In summary, the reader should learn important differential diagnoses and accompanying symptoms of exophthalmos, thus enabling essential clinical examinations and adequate imaging.

  11. Diagnostic Classification Models: Thoughts and Future Directions

    ERIC Educational Resources Information Center

    Henson, Robert A.

    2009-01-01

    The paper by Drs. Rupp and Templin provides a much needed step toward the general application of diagnostic classification modeling (DCMs). The authors have provided a summary of many of the concepts that one must consider to properly apply a DCM (which ranges from model selection and estimation, to assessing the appropriateness of the model using…

  12. Salivary diagnostics

    PubMed Central

    Lee, J.M.; Garon, E.; Wong, D.T.

    2010-01-01

    The ability to monitor health status, disease onset and progression, and treatment outcome through non-invasive means is a most desirable goal in the health care promotion and delivery. There are three prerequisites to materialize this goal: specific biomarkers associated with a health or disease state; a non-invasive approach to detect and monitor the biomarkers; and the technologies to discriminate the biomarkers. A national initiative catalyzed by the National Institute of Dental & Craniofacial Research (NIDCR) has created a roadmap to achieve these goals through the use of oral fluids as the diagnostic medium to scrutinize the health and/or disease status of individuals. Progress has shown this is an ideal opportunity to bridge state of the art saliva-based biosensors, optimized to disease discriminatory salivary biomarkers, for diagnostic applications. Oral fluid being the ‘mirror of body’ is a perfect medium to be explored for health and disease surveillance. The translational applications and opportunities are enormous. PMID:19627522

  13. NASA Information Summaries.

    ERIC Educational Resources Information Center

    Mar, May 1987, 1988

    1988-01-01

    This document consists of 11 "NASA Information Summaries" grouped together: (1) "Our Planets at a Glance" (PMS-010); (2) "Space Shuttle Mission Summary: 1985-1986" (PMS-005); (3) "Astronaut Selection and Training" (PMS-019); (4) "Space Station" (PMS-008); (5) "Materials Processing in…

  14. NFSMI Research Summary

    ERIC Educational Resources Information Center

    Nettles, Mary Frances

    2014-01-01

    The NFSMI Research Summary is a continuing series of summaries reporting recently completed research and research-based resources funded by the National Food Service Management Institute. The following research studies are summarized in this article: (1) Succession Planning for Management Level Staff in School Nutrition Programs; (2)…

  15. Sulfurization Growth of SnS Thin Films and Experimental Determination of Valence Band Discontinuity for SnS-Related Solar Cells

    NASA Astrophysics Data System (ADS)

    Sugiyama, Mutsumi; Murata, Yoshitsuna; Shimizu, Tsubasa; Ramya, Kottadi; Venkataiah, Chinna; Sato, Tomoaki; Ramakrishna Reddy, K. T.

    2011-05-01

    Tin sulphide is considered to be a potential candidate for the development of low cost polycrystalline thin film solar cells. The advantages of using sulfurization process to grow SnS films were demonstrated. Polycrystalline p-type SnS films were obtained by a simple dry process at 300 °C for 90 min. The sulfurization condition depends on the deposition method of the Sn precursor. Using single-phase SnS films, band discontinuities at SnS/CdS and SnO2/SnS heterointerfaces were measured by X-ray photoelectron spectroscopy. The valence band offsets were determined to be approximately 1.5 eV for SnS/CdS and 3.5 eV for SnO2/SnS interfaces. Using these values and the energy band gaps of the corresponding layers, the energy band diagram was developed. It indicated that the SnS/CdS heterojunction is of TYPE-II form of heterostructure. This result indicated that SnS-related solar cells with CdS as window layer do not have an ideal band structure that could give high conversion efficiency.

  16. Nano-flower and nano-wall SnS2 films fabricated with controllable shape and size by the PECVD method

    NASA Astrophysics Data System (ADS)

    Cheng, L. L.; Liu, M. H.; Wang, S. C.; Wang, M. X.; Wang, G. D.; Zhou, Q. Y.; Chen, Z. Q.

    2013-01-01

    In the present work, SnS2 films are deposited from solid source materials of S, Na2S2O3 ṡ 5H2O and SnCl4 ṡ 5H2O by the plasma-enhanced chemical vapor deposition (PECVD) method. Through controlling the deposition parameters, SnS2 films with nano-flower and nano-wall structure can be deposited without using any additives. By changing the deposition parameters, such as the molar ratio of S/Sn in source material, deposition temperature and the different kinds of sulfur source materials, SnS2 films with different morphology, building block and chemical composition can be produced. Furthermore, the formation mechanisms of the obtained morphologies have also been studied. It is mainly based on the crystal growth habit and the influence of the concentration of the sulfur radical in the vicinity of the growing surface. Moreover, the optical properties of SnS2 films have also been discussed. Due to the small size of SnS2 nanostructures, optical band gaps display the significant blue shift.

  17. High-quality SnO2@SnS2 core-shell heterojunctions: Designed construction, mechanism and photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Yang, Junyou; Qu, Qiuliang; Zhu, Pinwen; Li, Weixin

    2015-01-01

    High-quality SnO2@SnS2 core-shell heterojunctions have been constructed through sulfurization of SnO2 nanoflowers self-sacrificial templates with H2S gas at relatively low temperature in this paper. The unreacted SnO2 core and the in-situ synthesized SnS2 shell are in good crystallinity with a low lattice mismatch interface. The formation mechanism of the core-shell heterostructures have been examined by experiments and theoretic computation from the perspectives of both adsorption and diffusion. When used as photoanode in all-solid-state semiconductor-sensitized solar cells, the SnO2@SnS2 core-shell heterojunctions based hybrid solar cell shows a promising conversion efficiency of 1.45% under 1 sun illumination, which is over 5 times than that of SnS2 quantum dot sensitized SnO2 electrode made by the common chemistry bath deposition method. The enhanced photovoltaic performance is contributed to the unique structure of SnO2@SnS2 core-shell heterojunctions which provide highly covered sensitizers and favored interface for suppressing the charge recombination from SnO2 to electrolyte. This strategy and understanding can be extended to other nanostructure core-shell architecture and fields.

  18. The SNS/HFIR Web Portal System How Can it Help Me?

    SciTech Connect

    Miller, Stephen D; Geist, Al; Herwig, Kenneth W; Peterson, Peter F; Reuter, Michael A; Ren, Shelly; Bilheux, Jean-Christophe; Campbell, Stuart I; Kohl, James Arthur; Vazhkudai, Sudharshan S; Cobb, John W; Lynch, Vickie E; Chen, Meili; Trater, James R

    2010-01-01

    Abstract. In a busy world, continuing with the status-quo, to do things the way we are already familiar, often seems to be the most efficient way to conduct our work. We look for the value-add to decide if investing in a new method is worth the effort. How shall we evaluate if we have reached this tipping point for change? For contemporary researchers, understanding the properties of the data is a good starting point. The new generation of neutron scattering instruments being built are higher resolution and produce one or more orders of magnitude larger data than the previous generation of instruments. For instance, we have grown out of being able to perform some important tasks with our laptops the data are too big and the computations would simply take too long. These large datasets can be problematic as facility users now begin to grapple with many of the same issues faced by more established computing communities. These issues include data access, management, and movement, data format standards, distributed computing, and collaboration among others. The Neutron Science Portal has been architected, designed, and implemented to provide users with an easy-to-use interface for managing and processing data, while also keeping an eye on meeting modern cybersecurity requirements imposed on institutions. The cost of entry for users has been lowered by utilizing a web interface providing access to backend portal resources. Users can browse or search for data which they are allowed to see, data reduction applications can be run without having to load the software, sample activation calculations can be performed for SNS and HFIR beamlines, McStas simulations can be run on TeraGrid and ORNL computers, and advanced analysis applications such as those being produced by the DANSE project can be run. Behind the scenes is a live cataloging system which automatically catalogs and archives experiment data via the data management system, and provides proposal team members access

  19. Rotorcraft Diagnostics

    NASA Technical Reports Server (NTRS)

    Haste, Deepak; Azam, Mohammad; Ghoshal, Sudipto; Monte, James

    2012-01-01

    Health management (HM) in any engineering systems requires adequate understanding about the system s functioning; a sufficient amount of monitored data; the capability to extract, analyze, and collate information; and the capability to combine understanding and information for HM-related estimation and decision-making. Rotorcraft systems are, in general, highly complex. Obtaining adequate understanding about functioning of such systems is quite difficult, because of the proprietary (restricted access) nature of their designs and dynamic models. Development of an EIM (exact inverse map) solution for rotorcraft requires a process that can overcome the abovementioned difficulties and maximally utilize monitored information for HM facilitation via employing advanced analytic techniques. The goal was to develop a versatile HM solution for rotorcraft for facilitation of the Condition Based Maintenance Plus (CBM+) capabilities. The effort was geared towards developing analytic and reasoning techniques, and proving the ability to embed the required capabilities on a rotorcraft platform, paving the way for implementing the solution on an aircraft-level system for consolidation and reporting. The solution for rotorcraft can he used offboard or embedded directly onto a rotorcraft system. The envisioned solution utilizes available monitored and archived data for real-time fault detection and identification, failure precursor identification, and offline fault detection and diagnostics, health condition forecasting, optimal guided troubleshooting, and maintenance decision support. A variant of the onboard version is a self-contained hardware and software (HW+SW) package that can be embedded on rotorcraft systems. The HM solution comprises components that gather/ingest data and information, perform information/feature extraction, analyze information in conjunction with the dependency/diagnostic model of the target system, facilitate optimal guided troubleshooting, and offer

  20. 1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS.

    SciTech Connect

    LAMBIASE,R.ENG,W.SANDBERG,J.DEWAN,S.HOLMES,R.RUST,K.ZENG,J.

    2004-03-10

    This paper describes simulation and experimental results for a 1400A, {+-} 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m{Omega}, 160{micro}H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500{micro}s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase shifted (O{sup o}, 60{sup o} & 120{sup o}) converters each with 40 kHz switching frequency (IGBT at 20kHz), has been achieved. In this paper, the circuit topology, relevant system specifications and experimental results that meet the requirements of the power supply are described in detail. A unique six pulse SCR rectifier circuit with capacitor storage has been implemented to achieve minimum pulse width to meet required performance during current fall time below 50A due to the very narrow pulse width and non-linearity from IGBT turn-on/off times.

  1. Carbon nanotubes-nanoflake-like SnS2 nanocomposite for direct electrochemistry of glucose oxidase and glucose sensing.

    PubMed

    Li, Juan; Yang, Zhanjun; Tang, Yan; Zhang, Yongcai; Hu, Xiaoya

    2013-03-15

    Multi-walled carbon nanotubes (MWCNTs)-nanoflake-like SnS(2) nanocomposite were designed for immobilization of glucose oxidase (GOx). The direct electrochemistry of GOx and glucose sensing at MWCNTs-SnS(2) modified glassy carbon electrode were studied. Compared with single MWCNTs or SnS(2), the MWCNTs-SnS(2) film has larger surface area and provides a more favorable microenvironment for facilitating the electron transfer between enzyme and electrode surface. The properties of GOx/MWCNTs-SnS(2) were examined by scanning electron microscopy, UV-vis spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry. The immobilized enzyme on MWCNTs-SnS(2) composite film retained its native structure and bioactivity and showed a surface controlled, reversible two-proton and two-electron transfer reaction with a apparent electron transfer rate constant of 3.96 s(-1). The constructed glucose biosensor exhibits wider linear range from 2.0×10(-5) M to 1.95×10(-3) M, much lower detection limit of 4.0×10(-6) M at signal-to-noise of 3 and higher sensitivity of 21.65 mA M(-1) cm(-2) than our previous nanoflake-like SnS(2)-based glucose sensor. The proposed biosensor has excellent selectivity, good reproducibility, and acceptable operational stability and can be successfully applied in the reagentless glucose sensing at -0.43 V. This MWCNTs-SnS(2) composite provides a new avenue for immobilizing proteins and fabricating excellent biosensors.

  2. Development of nanodiamond foils for H- stripping to Support the Spallation Neutron Source (SNS) using hot filament chemical vapor deposition

    SciTech Connect

    Vispute, R D; Ermer, Henry K; Sinsky, Phillip; Seiser, Andrew; Shaw, Robert W; Wilson, Leslie L

    2014-01-01

    Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a small foil about the size of a postage stamp is critical to the operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control film thickness. The results are discussed in the light of development of nanodiamond foils that

  3. Mitigation of the electron-cloud effect in the PSR and SNS proton storage rings by tailoring the bunch profile

    SciTech Connect

    Pivi, M.; Furman, M.A.

    2003-05-20

    For the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electroncloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal bunch profile at fixed bunch charge, resulting in a significant decrease in the electron-cloud effect. We briefly discuss the experimental difficulties expected in the implementation of this cure.

  4. Ternary Cu2SnS3 cabbage-like nanostructures: large-scale synthesis and their application in Li-ion batteries with superior reversible capacity

    NASA Astrophysics Data System (ADS)

    Qu, Baihua; Li, Hongxing; Zhang, Ming; Mei, Lin; Chen, Libao; Wang, Yanguo; Li, Qiuhong; Wang, Taihong

    2011-10-01

    In this paper, novel ternary Cu2SnS3 cabbage-like nanostructures are synthesized on a large scale via a facile solvothermal route. The individual Cu2SnS3 cabbage-like hierarchitecture is constructed from 2D nanosheets with thickness of about 15.6 nm. The Cu2SnS3 electrodes exhibit an initial reversible capacity of 842 mAh g-1 and still reach 621 mAh g-1 after 50 cycles. Such an admirable performance could be related to their 3D porous structural features as well as the high electrical conductivity induced by Cu. The electrochemical properties of the 3D hierarchical nanostructures imply its potential application in high energy density Li-ion batteries.

  5. Biofuels: Project summaries

    SciTech Connect

    Not Available

    1994-07-01

    The US DOE, through the Biofuels Systems Division (BSD) is addressing the issues surrounding US vulnerability to petroleum supply. The BSD goal is to develop technologies that are competitive with fossil fuels, in both cost and environmental performance, by the end of the decade. This document contains summaries of ongoing research sponsored by the DOE BSD. A summary sheet is presented for each project funded or in existence during FY 1993. Each summary sheet contains and account of project funding, objectives, accomplishments and current status, and significant publications.

  6. Climate Monitoring and Diagnostics Laboratory No. 18. Summary report, 1989

    SciTech Connect

    Komhyr, W.D.; Rosson, R.M.

    1990-12-01

    Contents: CMDL station information; observatory reports; aerosols and radiation monitoring group; carbon cycle group; ozone group; acquisition and data management; air quality group; nitrous oxide and halocarbons group; a joint U.S./U.S.S.R. experiment for the study of desert dust and its impact on local meteorological conditions and climate; annual ozone cycle and decade trend at South Pole; wintertime black carbon aerosol measurements over the southwestern United States, December 1989; cooperative programs; precipitation chemistry; continuous aerosol monitoring with the epiphaniometer at mlo; antarctic ultraviolet spectroradiometer monitoring program; chemical resolution of fine aerosol mass at mlo: the role of organic matter; artificial windshielding of precipitation gauges in the arctic; UVB monitoring data from Rockville, Maryland; Robertson-Berger UVB meter; the CSIRO latitudinal gradient study: methane data from air samples collected at Cape Grim, Tasmania; secular variation in the carbon-13 content of atmospheric carbon dioxide; snow bunting nesting study at Barrow, Alaska; optical depth retrieval with the sunphotometer; tropospheric nitrogen oxide during spring at Barrow; chemical analyses of atmospheric particulates and gases at mlo; a temperature inversion climatology for barrow: 1976-1985; the global precipitation chemistry project; radioactivity in the surface air at brw, mlo, smo, and spo; total nitrate variations at Mauna Loa; seasonal and latitudinal trends in the (13)c/(12)c ratio of methane; aerosol constituents at American Samoa, November 1989; update on the o-ring bias; trends of the carbon isotopi composition of atmospheric methane in the southern hemisphere; bromine and surface ozone atmospheric chemistry at Barrow, Alaska, during spring 1989; USGS Barrow Observatory; radon from distant continents detected at the Mauna Loa Observatory.

  7. Summary report for CF6 jet engine diagnostics program

    NASA Technical Reports Server (NTRS)

    Fasching, W. A.; Stricklin, R.

    1982-01-01

    Cockpit cruise recordings and test cell data in conjunction with hardware inspection results from airline overhaul shops were analyzed to define the extent and magnitude of performance deterioration of the General Electric CF6 high bypass turbofan engines. The magnitude of Short Term deterioration from the Long Term was isolated and the individual damage mechanisms that were the cause for the majority of the performance deterioration were identified. A potential for reduction in compressor clearance and a potential for improvement in turbine roundness, which corresponds to cruise SFC reductions of 0.38 and 0.36 percent, respectively, were identified.

  8. Influence of the deposition parameters on the properties of SnS2 films prepared by PECVD method combined with solid sources

    NASA Astrophysics Data System (ADS)

    Wang, Shengming; Wang, Shicai; Chen, Junfeng; Liu, Pei; Chen, Ming; Xiong, Hao; Guo, Fu; Liu, Minghai

    2014-09-01

    Hexagonal tin disulfide (SnS2) films were deposited by plasma-enhanced chemical vapor deposition (PECVD) method combined with solid sources, in which SnCl4·5H2O and Na2S2O3 were used as the tin and sulfur sources, respectively. Nano-sheet and nano-flower structure SnS2 films were obtained under different experimental conditions. The nano-sheet SnS2 films were built by irregular nanoplates with 400 ± 100 nm in length and 10 nm in thickness. And the nano-flower SnS2 films consisted of uniform nano-flowers in size with the diameter being around 1 μm. The influence of different substrates, the annealing treatment and the substrate temperature on the crystal structure, surface morphology, chemical composition, and optical properties of the SnS2 films were systemically discussed. The results show that the crystal structure and surface morphology have some differences in the films deposited on different substrates. After annealing treatment, the crystallinity of the SnS2 films increases, and at the same time, the internal stress reduces. However, there is no change in the stress direction. The surface morphology of the films turns into nano-flower from nano-sheet when the substrate temperature increases. The corresponding optical band gaps of the films are 2.68, 2.86, and 2.95 eV, which all show significant blue shift mainly due to the quantum confinement effect.

  9. Fabrication of solar cells based on Cu2ZnSnS4 prepared from Cu2SnS3 synthesized using a novel chemical procedure

    NASA Astrophysics Data System (ADS)

    Correa, John M.; Becerra, Raúl A.; Ramírez, Asdrubal A.; Gordillo, Gerardo

    2016-11-01

    Solar cells based on kesterite-type Cu2ZnSnS4 (CZTS) thin films were fabricated using a chemical route to prepare the CZTS films, consisting in sequential deposition of Cu2SnS3 (CTS) and ZnS thin films followed by annealing at 550 °C in nitrogen atmosphere. The CTS compound was prepared in a one-step process using a novel chemical procedure consisting of simultaneous precipitation of Cu2S and SnS2 performed by diffusion membranes assisted CBD (chemical bath deposition) technique. Diffusion membranes were used to optimize the kinetic growth through a moderate control of release of metal ions into the work solution. As the conditions for the formation in one step of the Cu2SnS3 compound have not yet been reported in literature, special emphasis was put on finding the parameters that allow growing the Cu2SnS3 thin films by simultaneous precipitation of Cu2S and SnS2. For that, we propose a methodology that includes numerical solution of the equilibrium equations that were established through a study of the chemical equilibrium of the system SnCl2, Na3C6H5O7·2H2O, CuCl2 and Na2S2O3·5H2O. The formation of thin films of CTS and CZTS free of secondary phases grown with a stoichiometry close to that corresponding to the Cu2SnS3 and Cu2ZnSnS4 phases, was verified through measurements of X-ray diffraction (XRD) and Raman spectroscopy. Solar cell with an efficiency of 4.2%, short circuit current of 16.2 mA/cm2 and open-circuit voltage of 0.49 V was obtained.

  10. SnS2- Compared to SnO2-Stabilized S/C Composites toward High-Performance Lithium Sulfur Batteries.

    PubMed

    Li, Xiaona; Lu, Yue; Hou, Zhiguo; Zhang, Wanqun; Zhu, Yongchun; Qian, Yitai; Liang, Jianwen; Qian, Yitai

    2016-08-03

    The common sulfur/carbon (S/C) composite cathodes in lithium sulfur batteries suffer gradual capacity fading over long-term cycling incurred by the poor physical confinement of sulfur in a nonpolar carbon host. In this work, these issues are significantly relieved by introducing polar SnO2 or SnS2 species into the S/C composite. SnO2- or SnS2-stabilized sulfur in porous carbon composites (SnO2/S/C and SnS2/S/C) have been obtained through a baked-in-salt or sealed-in-vessel approach at 245 °C, starting from metallic tin (mp 231.89 °C), excess sulfur, and porous carbon. Both of the in situ-formed SnO2 and SnS2 in the two composites could ensure chemical interaction with lithium polysulfide (LiPS) intermediates proven by theoretical calculation. Compared to SnO2/S/C, the SnS2/S/C sample affords a more appropriate binding effect and shows lower charge transfer resistance, which is important for the efficient redox reaction of the adsorbed LiPS intermediates during cycling. When used as cathodes for Li-S batteries, the SnS2/S/C composite with sulfur loading of 78 wt % exhibits superior electrochemical performance. It delivers reversible capacities of 780 mAh g(-1) after 300 cycles at 0.5 C. When further coupled with a Ge/C anode, the full cell also shows good cycling stability and efficiency.

  11. Beaches National Summary

    EPA Pesticide Factsheets

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes a national summary report about beach closings and advisories for the previous year's swimming season.

  12. Solution-processable glass LiI-Li4SnS4 superionic conductors for all-solid-state Li-ion batteries

    DOE PAGES

    Kern Ho Park; Oh, Dae Yang; Choi, Young Eun; ...

    2015-12-22

    The new, highly conductive (4.1 × 10–4 S cm–1 at 30 °C), highly deformable, and dry-air-stable glass 0.4LiI-0.6Li4SnS4 is prepared using a homogeneous methanol solution. Furthermore, the solution process enables the wetting of any exposed surface of the active materials with highly conductive solidified electrolytes (0.4LiI-0.6Li4SnS4), resulting in considerable improvements in electrochemical performances of these electrodes over conventional mixture electrodes.

  13. Site environmental report summary

    SciTech Connect

    Not Available

    1992-12-31

    In this summary of the Fernald 1992 Site Environmental Report the authors will describe the impact of the Fernald site on man and the environment and provide results from the ongoing Environmental Monitoring Program. Also included is a summary of the data obtained from sampling conducted to determine if the site complies with DOE, US Environmental Protection Agency (USEPA), and Ohio EPA (OEPA) requirements. These requirements are set to protect both man and the environment.

  14. Multidisciplinary molecular diagnostics: the 9th European meeting on molecular diagnostics.

    PubMed

    Loonen, Anne J M; Schuurman, Rob; van den Brule, Adriaan J C

    2016-01-01

    This report presents a summary of the 9th European Meeting on Molecular Diagnostics held in Noordwijk, The Netherlands, 14-16 October 2015. This 3-day conference covered many relevant topics in the field of molecular diagnostics in humans, including infectious disease, oncology, outbreak management, population-based cancer screening, standardization and quality control, chronic diseases and pharmacogenetics. Beyond these different areas, shared values are new technologies and novel technical and clinical applications. Approximately 450 participants, the majority coming from European countries, attended the meeting. Besides high quality scientific presentations, more than 35 diagnostic companies presented their latest innovations, altogether in an informal and inspiring scientific ambience.

  15. The SNS/HFIR Web Portal System - How Can it Help Me?

    NASA Astrophysics Data System (ADS)

    Miller, Stephen D.; Geist, Al; Herwig, Kenneth W.; Peterson, Peter F.; Reuter, Michael A.; Ren, Shelly; Bilheux, Jean-Christophe; Campbell, Stuart I.; Kohl, James A.; Vazhkudai, Sudharshan S.; Cobb, John W.; Lynch, Vickie E.; Chen, Meili; Trater, James R.; Smith, Bradford C.; (William Swain, Tom; Huang, Jian; Mikkelson, Ruth; Mikkelson, Dennis; een, Mar K. L. Gr

    2010-11-01

    In a busy world, continuing with the status-quo, to do things the way we are already familiar, often seems to be the most efficient way to conduct our work. We look for the value-add to decide if investing in a new method is worth the effort. How shall we evaluate if we have reached this tipping point for change? For contemporary researchers, understanding the properties of the data is a good starting point. The new generation of neutron scattering instruments being built are higher resolution and produce one or more orders of magnitude larger data than the previous generation of instruments. For instance, we have grown out of being able to perform some important tasks with our laptops - the data are too big and the computations would simply take too long. These large datasets can be problematic as facility users now begin to grapple with many of the same issues faced by more established computing communities. These issues include data access, management, and movement, data format standards, distributed computing, and collaboration among others. The Neutron Science Portal has been architected, designed, and implemented to provide users with an easy-to-use interface for managing and processing data, while also keeping an eye on meeting modern cybersecurity requirements imposed on institutions. The cost of entry for users has been lowered by utilizing a web interface providing access to backend portal resources. Users can browse or search for data which they are allowed to see, data reduction applications can be run without having to load the software, sample activation calculations can be performed for SNS and HFIR beamlines, McStas simulations can be run on TeraGrid and ORNL computers, and advanced analysis applications such as those being produced by the DANSE project can be run. Behind the scenes is a "live cataloging" system which automatically catalogs and archives experiment data via the data management system, and provides proposal team members access to

  16. Relation between SNs and GRBs in a quark-deconfinement model

    NASA Astrophysics Data System (ADS)

    Drago, Alessandro; Pagliara, Giuseppe; Pagliaroli, Giulia; Villante, Francesco; Vissani, Francesco

    We discuss a model in which compact stars can release a huge amount of energy by combusting neutrons and protons into deconfined quarks. In this way quark deconfinement can constitute the inner engine of at least a fraction of the "long" GRBs. We show that the release of energy due to quark deconfinement is consistent with the standard scenario describing the fate of massive stars. The main role played by quark deconfinement is to provide an extra flux of neutrinos, which can revitalize the explosion. This is specially important in the case of marginally failed SNs, in which the fall-back is small. A rapid rotation of the progenitor can also help in reducing the fall-back, and in providing to the compact star the time delay needed to deconfine quarks. We discuss the temporal structure of GRBs and the possible interpretation of GRBs in which a time delay exists between the SN explosion and the GRB. We also discuss the various active periods of the GRB in terms of progressive rearrangements of the compact star at the center. In conclusion, we show that a model for GRBs based on quark deconfinement is not alternative to the collapsar-hypernova model, but at the contrary it completes that model in the cases of small fall-back, after a marginally failed SN explosion. 1) Berezhiani Z., Bombaci I., Drago A., Frontera F. and Lavagno A. "Gamma-ray bursts from delayed collapse of neutron stars to quark matter stars". Astrophys. J. 586 (2003) 1250 2) Drago, A., Lavagno, A. and Pagliara, G. "Effects of color superconductivity on the structure and formation of compact stars". Phys. Rev. D69 (2004) 057505 3) Drago, A. and Pagliara, G. "Quiescent times in Gamma-Ray-Bursts: hints of a dormant inner engine". Astrophys. J. 665 (2007) 1227 4) Alford, M., Blaschke D., Drago A., Klahn T., Pagliara G. and Schaffner-Bielich J. "Quark matter in compact stars?". Nature 445 (2007) E7 5) Drago A., Lavagno A. and Parenti I. "Burning of a hadronic star into a quark or a hybrid star". Astrophys

  17. Preparation and characterization of sphere-like Cu2SnS3 nanoparticles and their dropcasted thin films

    NASA Astrophysics Data System (ADS)

    Shadrokh, Zohreh; Yazdani, Ahmad; Eshghi, Hosein

    2017-01-01

    Ternary sphere-like Cu2SnS3(CTS) semiconductor and 2D hexagonal sheets were synthesized via a simple solvothermal method using PVP as the surface ligand at two temperatures of 180 and 220 °C. The structural, morphological, and chemical compositions as well as optical properties of as-synthesized CTS particles were characterized using X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray spectrometry (EDS), field emission scanning electron microscopy (FESEM), and UV–Vis spectroscopy. The size of sphere-like particles and the side length of hexagonal sheets were within the range of 120–140 nm and 500 nm–2 {{μ }}{{m}}, respectively. FESEM, XRD, and EDS were analyzed to investigate the mechanism of the morphological evolution of CTS particles. CTS particles showed proliferation of Sn atomic ratio, which is strongly sensitive to reaction temperature and, highly affects the increase of band gap energy from 1.36 to 1.53 eV due to generation metal defects and formation SnS2. The optical analysis via the transmittance and reflectance reveals that the band-gap energy of dropcasted CTS thin films decreases after annealing due to grain growth and change of chemical compositions. Photo-responses of CTS nanocrystal thin films indicated a considerable increase in the conductivity of the films under light illumination. All these results showed the potential of these films for solar cell applications.

  18. V-doped SnS2: a new intermediate band material for a better use of the solar spectrum.

    PubMed

    Wahnón, Perla; Conesa, José C; Palacios, Pablo; Lucena, Raquel; Aguilera, Irene; Seminovski, Yohanna; Fresno, Fernando

    2011-12-07

    Intermediate band materials can boost photovoltaic efficiency through an increase in photocurrent without photovoltage degradation thanks to the use of two sub-bandgap photons to achieve a full electronic transition from the valence band to the conduction band of a semiconductor structure. After having reported in previous works several transition metal-substituted semiconductors as able to achieve the electronic structure needed for this scheme, we propose at present carrying out this substitution in sulfides that have bandgaps of around 2.0 eV and containing octahedrally coordinated cations such as In or Sn. Specifically, the electronic structure of layered SnS(2) with Sn partially substituted by vanadium is examined here with first principles quantum methods and seen to give favourable characteristics in this respect. The synthesis of this material in nanocrystalline powder form is then undertaken and achieved using solvothermal chemical methods. The insertion of vanadium in SnS(2) is found to produce an absorption spectrum in the UV-Vis-NIR range that displays a new sub-bandgap feature in agreement with the quantum calculations. A photocatalytic reaction-based test verifies that this sub-bandgap absorption produces highly mobile electrons and holes in the material that may be used for the solar energy conversion, giving experimental support to the quantum calculations predictions.

  19. Magnetic properties and cation ordering of nanopowders of the synthetic analogue of kuramite, Cu3SnS4

    NASA Astrophysics Data System (ADS)

    Benedetto, Francesco Di; Borrini, Daniele; Caneschi, Andrea; Fornaciai, Gabriele; Innocenti, Massimo; Lavacchi, Alessandro; Massa, Carlo Andrea; Montegrossi, Giordano; Oberhauser, Werner; Pardi, Luca A.; Romanelli, Maurizio

    2011-06-01

    An extensive characterisation of the magnetic properties of synthetic powders of kuramite, with formal composition Cu3SnS4, was performed. Powders were investigated through superconducting quantum interference device (SQUID) magnetometry, electron paramagnetic resonance (EPR) spectroscopy, X-ray powder diffraction (XRPD), scanning and transmission electron microscopies (SEM and TEM) and microanalysis. SEM and TEM reveal the presence of nanodimensioned particles. XRPD clearly shows that Cu3SnS4 crystallised in a cubic sphalerite-type structural model, in spite of the stannite-type tetragonal structure described for the natural phase. This difference arises from a full random distribution of cations. Synthetic kuramite nanopowders exhibit a marked paramagnetism, originated by the presence of Cu(II), definitely assessed by EPR measurements. Moreover, the overall magnetic behaviour of the sample cannot be simply ascribed to diluted paramagnetism, and this suggests the presence of strong superexchange interactions among Cu(II) ions even at room temperature. The main consequences of these results are the definitive assessment of the chemical formula Cu(I)2Cu(II)SnS4 and of a random distribution of Cu(II), Cu(I) and Sn(IV) ions within the available tetrahedral sites.

  20. The influence of color information on the recognition of color diagnostic and noncolor diagnostic objects.

    PubMed

    Bramão, Inês; Inácio, Filomena; Faísca, Luís; Reis, Alexandra; Petersson, Karl Magnus

    2011-01-01

    In the present study, the authors explore in detail the level of visual object recognition at which perceptual color information improves the recognition of color diagnostic and noncolor diagnostic objects. To address this issue, 3 object recognition tasks with different cognitive demands were designed: (a) an object verification task; (b) a category verification task; and (c) a name verification task. The authors found that perceptual color information improved color diagnostic object recognition mainly in tasks for which access to the semantic knowledge about the object was necessary to perform the task; that is, in category and name verification. In contrast, the authors found that perceptual color information facilitates noncolor diagnostic object recognition when access to the object's structural description from long-term memory was necessary--that is, object verification. In summary, the present study shows that the role of perceptual color information in object recognition is dependent on color diagnosticity.

  1. Origins of gene, genetic code, protein and life: comprehensive view of life systems from a GNC-SNS primitive genetic code hypothesis.

    PubMed

    Ikehara, K

    2002-03-01

    We have investigated the origin of genes, the genetic code, proteins and life using six indices (hydropathy, alpha-helix, beta-sheet and beta-turn formabilities, acidic amino acid content and basic amino acid content) necessary for appropriate three-dimensional structure formation of globular proteins. From the analysis of microbial genes, we have concluded that newly-born genes are products of nonstop frames (NSF) on antisense strands of microbial GC-rich genes [GC-NSF(a)] and from SNS repeating sequences [(SNS)n] similar to the GC-NSF(a) (S and N mean G or C and either of four bases, respectively). We have also proposed that the universal genetic code used by most organisms on the earth presently could be derived from a GNC-SNS primitive genetic code. We have further presented the [GADV]-protein world hypothesis of the origin of life as well as a hypothesis of protein production, suggesting that proteins were originally produced by random peptide formation of amino acids restricted in specific amino acid compositions termed as GNC-, SNS- and GC-NSF(a)-0th order structures of proteins. The [GADV]-protein world hypothesis is primarily derived from the GNC-primitive genetic code hypothesis. It is also expected that basic properties of extant genes and proteins could be revealed by considerations based on the scenario with four stages.

  2. Intriguing substitution of conducting layer triggered enhancement of thermoelectric performance in misfit-layered (SnS)1.2(TiS2)2

    NASA Astrophysics Data System (ADS)

    Yin, Cong; Hu, Qing; Wang, Guoyu; Huang, Tianyu; Zhou, Xiaoyuan; Zhang, Xiong; Dou, Yunwei; Kang, Bin; Tang, Jun; Liu, Ning; Ang, Ran

    2017-01-01

    We have systematically investigated the thermoelectric properties of misfit-layered chalcogenide (SnS)1.2(TiS2)2. Surprisingly, an unexpected Cu and Co substitution in the conducting TiS2 layer, acceptor dopant, can induce an exotic enhancement of thermoelectric performance. In particular, the value of dimensionless figure of merit ZT has increased by 33.3% and up to 0.42 at 720 K for Cu-substituted (SnS)1.2(Cu0.02Ti0.98S2)2. The present findings demonstrate that large effective mass and low carrier concentration are responsible for the emergence of large Seebeck coefficient and high power factor. Furthermore, the enhanced disorder effect due to the substitution accounts for the decrease of electronic thermal conductivity, while the increased phonon scattering of interlayer between SnS and TiS2 layers leads to the reduction of phononic thermal conductivity. Consequently, the Cu- and Co-substituted (SnS)1.2(TiS2)2 could be considered as a promising candidate of thermoelectric materials.

  3. Sensory neuron-specific sodium channel SNS is abnormally expressed in the brains of mice with experimental allergic encephalomyelitis and humans with multiple sclerosis

    NASA Astrophysics Data System (ADS)

    Black, Joel A.; Dib-Hajj, Sulayman; Baker, David; Newcombe, Jia; Cuzner, M. Louise; Waxman, Stephen G.

    2000-10-01

    Clinical abnormalities in multiple sclerosis (MS) have classically been considered to be caused by demyelination and/or axonal degeneration; the possibility of molecular changes in neurons, such as the deployment of abnormal repertoires of ion channels that would alter neuronal electrogenic properties, has not been considered. Sensory Neuron-Specific sodium channel SNS displays a depolarized voltage dependence, slower activation and inactivation kinetics, and more rapid recovery from inactivation than classical "fast" sodium channels. SNS is selectively expressed in spinal sensory and trigeminal ganglion neurons within the peripheral nervous system and is not expressed within the normal brain. Here we show that sodium channel SNS mRNA and protein, which are not present within the cerebellum of control mice, are expressed within cerebellar Purkinje cells in a mouse model of MS, chronic relapsing experimental allergic encephalomyelitis. We also demonstrate SNS mRNA and protein expression within Purkinje cells from tissue obtained postmortem from patients with MS, but not in control subjects with no neurological disease. These results demonstrate a change in sodium channel expression in neurons within the brain in an animal model of MS and in humans with MS and suggest that abnormal patterns of neuronal ion channel expression may contribute to clinical abnormalities such as ataxia in these disorders.

  4. Report on Partial Findings of an Ongoing Research: Social Networking Sites (SNS) as a Platform to Support Teaching and Learning in Secondary Schools

    ERIC Educational Resources Information Center

    Bt. Ubaidullah, Nor Hasbiah; Samsuddin, Khairulanuar; Bt. Fabil, Norsikin; Bt. Mahadi, Norhayati

    2011-01-01

    This paper reports the partial findings of a survey that was carried out in the analysis phase of an ongoing research for the development of a prototype of a Social Networking Site (SNS) to support teaching and learning in secondary schools. For the initial phase of the study, a quantitative research method was used based on a survey involving 383…

  5. A facile phosphine-free colloidal synthesis of Cu2SnS3 and Cu2ZnSnS4 nanorods with a controllable aspect ratio.

    PubMed

    Wang, Jian-Jun; Liu, Pai; Ryan, Kevin M

    2015-09-18

    Cu2SnS3 (CTS) nanorods were synthesized with a controllable aspect ratio via a facile phosphine-free colloidal synthesis. This synthesis can be readily extended to obtain Cu2ZnSnS4 (CZTS) nanorods with tunable Zn content.

  6. Ternary SnS2–xSex Alloys Nanosheets and Nanosheet Assemblies with Tunable Chemical Compositions and Band Gaps for Photodetector Applications

    PubMed Central

    Yu, Jing; Xu, Cheng-Yan; Li, Yang; Zhou, Fei; Chen, Xiao-Shuang; Hu, Ping-An; Zhen, Liang

    2015-01-01

    Ternary metal dichalcogenides alloys exhibit compositionally tunable optical properties and electronic structure, and therefore, band gap engineering by controllable doping would provide a powerful approach to promote their physical and chemical properties. Herein we obtained ternary SnS2−xSex alloys with tunable chemical compositions and optical properties via a simple one-step solvothermal process. Raman scattering and UV-vis-NIR absorption spectra reveal the composition-related optical features, and the band gaps can be discretely modulated from 2.23 to 1.29 eV with the increase of Se content. The variation tendency of band gap was also confirmed by first-principles calculations. The change of composition results in the difference of crystal structure as well as morphology for SnS2−xSex solid solution, namely, nanosheets assemblies or nanosheet. The photoelectrochemical measurements indicate that the performance of ternary SnS2−xSex alloys depends on their band structures and morphology characteristics. Furthermore, SnS2−xSex photodetectors present high photoresponsivity with a maximum of 35 mA W−1 and good light stability in a wide range of spectral response from ultraviolet to visible light, which renders them promising candidates for a variety of optoelectronic applications. PMID:26616539

  7. Summaries of Research - 1980.

    DTIC Science & Technology

    1980-01-01

    r AD-A124 289 SUMMARI ES OF RESEARCH - 98O(U) NAVAL MEDICAL RESEARCH 1/ INST B ETHESDA MD f98O UNCASFE F/G6/ S32 361111 *’~ A 12.0 1111L 25 1111...MICROCOPY RESOLUTION TEST CHART N~lONAL BUREAU OF STANDARDS 1963-A NAVAL MEDICAL RESEARCH INSTITUTE BETHESDA, MARYLAND SUMMARIES OF RESEARCH 1980 J...Vorosmarti, CAPT, MC, USN .0 Commanding Officer Naval Medical Rmearcdh Inotutuse I NAVAL MEICl4AL, RESEAR:i AND IEVEIOIPMENI O:OMMANI) ,v KEY TO

  8. Crisis Management: Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.; Dorman, Sally; Anderson, Luke; McNair, Daniel

    2013-01-01

    This article presents summaries of three studies relevant to school crisis response. The first report, "A Framework for International Crisis Intervention" (Sally Dorman), is a review of how existing crisis intervention models (including the NASP PREPaRE model) have been adapted for international use. The second article, "Responding…

  9. Executive Summaries: CIL '90.

    ERIC Educational Resources Information Center

    Elsweiler, John A., Jr.; And Others

    1990-01-01

    Presents summaries of 12 papers presented at the 1990 Computers in Libraries Conference. Topics discussed include online searching; microcomputer-based serials management; microcomputer-based workstations; online public access catalogs (OPACs); multitype library networking; CD-ROM searches; locally mounted online databases; collection evaluation;…

  10. Summary of Session III

    SciTech Connect

    Furman, M.A.

    2002-06-19

    This is a summary of the talks presented in Session III ''Simulations of Electron-Cloud Build Up'' of the Mini-Workshop on Electron-Cloud Simulations for Proton and Positron Beams ECLOUD-02, held at CERN, 15-18 April 2002.

  11. Crisis Management Research Summaries

    ERIC Educational Resources Information Center

    Brock, Stephen E., Ed.; Zhe, Elizabeth; Torem, Chris; Comeaux, Natashia; Dempsey, Allison

    2010-01-01

    This article presents a summary of recent crisis management publications. The first research report summarized, "Predictors of PTSD," was a study of predictor variables for responses to the World Trade Center attack. The second paper, "Effective Mental Health Response to Catastrophic Events," looked at effective responses following Hurricane…

  12. Project Summary and Conclusions

    NASA Technical Reports Server (NTRS)

    Sawin, Charles

    1999-01-01

    A top level summary of activities conducted throughout the course of the EDOMP in response to initial concerns at the outset of the program is provided. Significant findings from the investigations are summarized, together with resulting countermeasures that were implemented and flight rules that were developed in response to these findings. Subsequent paragraphs provide more information; details will be found in the referenced sections.

  13. SCES2016 Summary: Experiment

    SciTech Connect

    Thompson, Joe David

    2016-08-03

    Experimental results presented during the 2016 International Conference on Strongly Correlated Electron Systems (SECS2016) not only reflect the breadth of topics being explored in the field of strongly correlated systems but also the remarkable progress in discovery and understanding that is being made from their study. Lastly, this brief summary highlights just a few of the exciting experimental developments discussed at SCES2016.

  14. Saturn IB Launch Summary

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This chart provides a launch summary of the Saturn IB launch vehicle as of 1973. Developed by the Marshall Space Flight Center (MSFC) as an interim vehicle in MSFC's 'building block' approach to the Saturn rocket development, the Saturn IB utilized Saturn I technology to further develop and refine the larger boosters and the Apollo spacecraft capabilities required for the marned lunar missions.

  15. Healthcare. Executive Summary

    ERIC Educational Resources Information Center

    Carnevale, Anthony P.; Smith, Nicole; Gulish, Artem; Beach, Bennett H.

    2012-01-01

    This executive summary highlights several findings about healthcare. These are: (1) Healthcare is 18 percent of the U.S. economy, twice as high as in other countries; (2) There are two labor markets in healthcare: high-skill, high-wage professional and technical jobs and low-skill, low-wage support jobs; (3) Demand for postsecondary education in…

  16. NHS clinical knowledge summaries.

    PubMed

    Richards, Derek

    2009-01-01

    The UK National Health Service (NHS) Clinical Knowledge Summaries, formerly known as PRODIGY, are part of the National Library for Health and provide a source of evidence-based information and practical know-how relating to the common conditions managed in primary care.

  17. National NIF Diagnostic Program Fiscal Year 2002 Second Quarter Report

    SciTech Connect

    MacGowan, B

    2002-04-01

    Since October 2001 the development of the facility diagnostics for NIF has been funded by the NIF Director through the National NIF Diagnostic Program (NNDP). The current emphasis of the NNDP is on diagnostics for the early NIF quad scheduled to be available for experiment commissioning in FY03. During the past six months the NNDP has set in place processes for funding diagnostics, developing requirements for diagnostics, design reviews and monthly status reporting. Those processes are described in an interim management plan for diagnostics (''National NIF Diagnostic Program Interim Plan'', NIF-0081315, April 2002) and a draft Program Execution Plan (''Program Execution Plan for the National NlF Diagnostic Program'', NIF-0072083, October 2001) and documents cited therein. Work has been funded at Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Naval Research Laboratory (NRL), Sandia National Laboratories (SNL), Bechtel Nevada at Los Alamos and Santa Barbara. There are no major technical risks with the early diagnostics. The main concerns relate to integration of the diagnostics into the facility, all such issues are being worked. This report is organized to show the schedule and budget status and a summary of Change Control Board actions for the past six months. The following sections then provide short descriptions of the status of each diagnostic. Where design reviews or requirements documents are cited, the documents are available on the Diagnostics file server or on request.

  18. Evaluation of back contact in spray deposited SnS thin film solar cells by impedance analysis.

    PubMed

    Patel, Malkeshkumar; Ray, Abhijit

    2014-07-09

    The role of back metal (M) contact in sprayed SnS thin film solar cells with a configuration Glass/F:SnO2/In2S3/SnS/M (M = Graphite, Cu, Mo, and Ni) was analyzed and discussed in the present study. Impedance spectroscopy was employed by incorporating constant phase elements (CPE) in the equivalent circuit to investigate the degree of inhomogeneity associated with the heterojunction and M/SnS interfaces. A best fit to Nyquist plot revealed a CPE exponent close to unity for thermally evaporated Cu, making it an ideal back contact. The Bode phase plot also exhibited a higher degree of disorders associated with other M/SnS interfaces. The evaluation scheme is useful for other emerging solar cells developed from low cost processing schemes like spray deposition, spin coating, slurry casting, electrodeposition, etc.

  19. An investigation of the SNS Josephson junction as a three-terminal device. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Meissner, H.; Prans, G. P.

    1973-01-01

    A particular phenomenon of the SNS Josephson junction was investigated; i.e., control by a current entering the normal region and leaving through one of the superconducting regions. The effect of the control current on the junction was found to be dependent upon the ration of the resistances of the two halves of the N layer. A low frequency, lumped, nonlinear model was proposed to describe the electrical characteristics of the device, and a method was developed to plot the dynamic junction resistance as a function of junction current. The effective thermal noise temperature of the sample was determined. Small signal linearized analysis of the device suggests its use as an impedance transformer, although geometric limitations must be overcome. Linear approximation indicates that it is reciprocal and no power gain is possible. It is felt that, with suitable metallurgical and geometrical improvements, the device has promise to become a superconducting transistor.

  20. Eco-friendly p-type Cu2SnS3 thermoelectric material: crystal structure and transport properties

    PubMed Central

    Shen, Yawei; Li, Chao; Huang, Rong; Tian, Ruoming; Ye, Yang; Pan, Lin; Koumoto, Kunihito; Zhang, Ruizhi; Wan, Chunlei; Wang, Yifeng

    2016-01-01

    As a new eco-friendly thermoelectric material, copper tin sulfide (Cu2SnS3) ceramics were experimentally studied by Zn-doping. Excellent electrical transport properties were obtained by virtue of 3-dimensionally conductive network for holes, which are less affected by the coexistence of cubic and tetragonal phases that formed upon Zn subsitition for Sn; a highest power factors ~0.84 mW m−1 K−2 at 723 K was achieved in the 20% doped sample. Moreover, an ultralow lattice thermal conductivity close to theoretical minimum was observed in these samples, which could be related to the disordering of atoms in the coexisting cubic and tetragonal phases and the interfaces. Thanks to the phonon-glass-electron-crystal features, a maximum ZT ~ 0.58 was obtained at 723 K, which stands among the tops for sulfide thermoelectrics at the same temperature. PMID:27666524

  1. Analysis of electrical conduction mechanism in the high temperature range of the nanostructured photoabsorber Cu2SnS3

    NASA Astrophysics Data System (ADS)

    Lahlali, S.; Essaleh, L.; Belaqziz, M.; Chehouani, H.; Djessas, K.; Viallet, B.

    2016-11-01

    The dynamic electrical conduction in the bulk ternary semiconductor compound Cu2SnS3 is studied for the first time in the high temperature range from 300 °C to 440 °C in the frequency range 1 kHz-1 MHz. New activation energy for conduction mechanism is obtained and its frequency dependence is analyzed. The Cole-Cole representation is almost half circular indicating a single contribution to total electrical conduction through the material. The activation energy for the mean relaxation process, obtained separately from the analysis of imaginary part Z″ of complex impedance Z* and from the equivalent electric circuit, is estimated to be (942 ± 74) meV . The correlated barrier hopping model is considered to analyze the experimental data. The results are compared with those obtained previously in low temperature range.

  2. Three-dimensional particle trajectories and waste beam losses in injection dump beam line of SNS accumulator ring

    SciTech Connect

    Wang, Jian-Guang; Plum, Michael A

    2008-01-01

    The SNS ring injection dump beam line has been suffering high beam losses since its commissioning. In order to understand the mechanisms of the beam losses, we have performed 3D simulation studies of the beam line. The 3D models consist of three injection chicane dipoles and one injection dump septum magnet. 3D particle trajectories in the models are computed. We then extend particle optics calculations to the injection dump. Our studies have clearly shown some design and operation problems, that cause beam losses in the injection dump beam line. These include incorrect chicane dipole settings, incorrect position of a chicane dipole, too small aperture of injection dump septum, and inadequate focusing downstream. This paper reports our findings and the remedies to the injection beam loss problems.

  3. Air-Stable, High-Conduction Solid Electrolytes of Arsenic-Substituted Li4SnS4

    SciTech Connect

    Sahu, Gayatri; Lin, Zhan; Li, Juchuan; Liu, Zengcai; Dudney, Nancy J; Liang, Chengdu

    2014-01-01

    Lithium-ion-conducting solid electrolytes show promise for enabling high-energy secondary battery chemistries and solving safety issues associated with conventional lithium batteries. Achieving the combination of high ionic conductivity and outstanding chemical stability in solid electrolytes is a grand challenge for the synthesis of solid electrolytes. Herein we report the design of aliovalent substitution of Li4SnS4 to achieve high conduction and excellent air stability based on the hard and soft acids and bases theory. The composition of Li3.833Sn0.833As 0.166S4 has a high ionic conductivity of 1.39 mS/cm 1 at 25 C. Considering the high Li+ transference number, this phase conducts Li+ as well as carbonate-based liquid electrolytes. This research also addresses the compatibility of the sulfide-based solid electrolytes through chemical passivation.

  4. Light induced phase change in Cu2-xZn1.3SnS4 thin films

    NASA Astrophysics Data System (ADS)

    Kumar Samji, Sunil; Tiwari, Brajesh; Krishna Surendra, M.; Ramachandra Rao, M. S.

    2014-04-01

    Cu2ZnSnS4 and its alloy based thin film solar cells have shown better photovoltaic performance under Cu-poor and Zn-rich conditions. However, the effect of Cu-stoichiometry on the coexistence of kesterite (KS), stannite and/or partially disordered kesterite (PD-KS) phases and their influence on photovoltaic performance is not clearly understood. Raman studies were carried out on Cu2-xZn1.3SnS4 (x = 0, 0.3, and 0.5) thin films by changing the intensity of the incident laser beam. It was observed that both Cu-stoichiometry and incident laser beam intensity induce a disorder in the system. Disorder induced transformation of KS (I4¯) to PD-KS (I4¯2m) is explained by Raman studies.

  5. Eco-friendly p-type Cu2SnS3 thermoelectric material: crystal structure and transport properties

    NASA Astrophysics Data System (ADS)

    Shen, Yawei; Li, Chao; Huang, Rong; Tian, Ruoming; Ye, Yang; Pan, Lin; Koumoto, Kunihito; Zhang, Ruizhi; Wan, Chunlei; Wang, Yifeng

    2016-09-01

    As a new eco-friendly thermoelectric material, copper tin sulfide (Cu2SnS3) ceramics were experimentally studied by Zn-doping. Excellent electrical transport properties were obtained by virtue of 3-dimensionally conductive network for holes, which are less affected by the coexistence of cubic and tetragonal phases that formed upon Zn subsitition for Sn; a highest power factors ~0.84 mW m‑1 K‑2 at 723 K was achieved in the 20% doped sample. Moreover, an ultralow lattice thermal conductivity close to theoretical minimum was observed in these samples, which could be related to the disordering of atoms in the coexisting cubic and tetragonal phases and the interfaces. Thanks to the phonon-glass-electron-crystal features, a maximum ZT ~ 0.58 was obtained at 723 K, which stands among the tops for sulfide thermoelectrics at the same temperature.

  6. Vacuum System Upgrade for Extended Q-Range Small-Angle Neutron Scattering Diffractometer (EQ-SANS) at SNS

    SciTech Connect

    Stone, Christopher M.; Williams, Derrick C.; Price, Jeremy P.

    2016-09-23

    The Extended Q-Range Small-Angle Neutron Scattering Diffractometer (EQ-SANS) instrument at the Spallation Neutron Source (SNS), Oak Ridge, Tennessee, incorporates a 69m3 detector vessel with a vacuum system which required an upgrade with respect to performance, ease of operation, and maintenance. The upgrade focused on improving pumping performance as well as optimizing system design to minimize opportunity for operational error. This upgrade provided the following practical contributions: Reduced time required to evacuate from atmospheric pressure to 2mTorr from 500-1,000 minutes to 60-70 minutes Provided turn-key automated control with a multi-faceted interlock for personnel and machine safety.

  7. Coherent neutrino-nucleus scattering detection with a CsI[Na] scintillator at the SNS spallation source

    NASA Astrophysics Data System (ADS)

    Collar, J. I.; Fields, N. E.; Hai, M.; Hossbach, T. W.; Orrell, J. L.; Overman, C. T.; Perumpilly, G.; Scholz, B.

    2015-02-01

    We study the possibility of using CsI[Na] scintillators as an advantageous target for the detection of coherent elastic neutrino-nucleus scattering (CENNS), using the neutrino emissions from the SNS spallation source at Oak Ridge National Laboratory. The response of this material to low-energy nuclear recoils like those expected from this process is characterized. Backgrounds are studied using a 2 kg low-background prototype crystal in a dedicated radiation shield. The conclusion is that a planned 14 kg detector should measure approximately 550 CENNS events per year above a demonstrated ~ 7 keVnr low-energy threshold, with a signal-to-background ratio sufficient for a first measurement of the CENNS cross-section. The cross-section for the 208Pb(νe ,e-)208Bi reaction, of interest for future supernova neutrino detection, can be simultaneously obtained.

  8. GLOVEBOX GLOVE CHARACTERIZATION SUMMARY

    SciTech Connect

    Korinko, P.

    2012-05-14

    A task was undertaken to determine primarily the permeation behavior of various glove compounds from four manufacturers. As part of the basic characterization task, the opportunity to obtain additional mechanical and thermal properties presented itself. Consequently, a total of fifteen gloves were characterized for permeation, Thermogravimetric Analysis, Puncture Resistance, Tensile Properties and Dynamic Mechanical Analysis. Detailed reports were written for each characterization technique used. This report contains the summary of the results.

  9. Summaries of Research 1986

    DTIC Science & Technology

    1986-01-01

    IMMUNOSORBENT ASSAY LEGIONELLA LEGIONNAIRES # DISEASE AD A174 390 NMRI 86-0022 CHRISTnAN CL CATRON PW FLYNN ET WEATHERSBY PK IN VIVO MICROUBBLE DETECTION...ENVIRONMENTAL MEDICINE, INFECTIOUS DISEASES , DIVING MEDICINE, AND IMMUNOBIOLOGY AND TRANSPLANTATION RESEARCH. THIS ISSUE OF THE SUMMARIES OF RESEARCH... DISEASES 198b JAN;153(l):98-108 CASUALTY CARE N.A. BACTERIAL TOXINS DOGS ENDOTOXINS LIPOPOLYSACCHARIDES MICE AD A165 068 NMRI 86-0002 CHERNOW B ROTH BL

  10. Research Summaries of 1989

    DTIC Science & Technology

    1989-01-01

    0 M--_- NAVAL MEDICAL _ RESEARCH INSTITUTE / _- BETHESDA, MARYLAND = DTI ’N ELECTE I ’ll ’ JUNO 3199J’: ~ss RESEARCH SUMMARIES OF 1989 LARRY W...LAUGHLIN, CAPT, MC, USN COMMANDING OFFICER NAVAL MEDICAL RESEARCH INSTITUTE NAVAL MEDICAL RESEARCH AND DEVELOPMENT COMMAND 91-00890 fr’,i ~v - - 1 042i...OF MONITORING ORGANIZATION Naval Medical Research (If applicable) Naval Medical Command Institute 6c. ADDRESS (Gty, State, and ZIP Code) 7b. ADDRESS

  11. ULSGEN (Uplink Summary Generator)

    NASA Technical Reports Server (NTRS)

    Wang, Y.-F.; Schrock, M.; Reeve, T.; Nguyen, K.; Smith, B.

    2014-01-01

    Uplink is an important part of spacecraft operations. Ensuring the accuracy of uplink content is essential to mission success. Before commands are radiated to the spacecraft, the command and sequence must be reviewed and verified by various teams. In most cases, this process requires collecting the command data, reviewing the data during a command conference meeting, and providing physical signatures by designated members of various teams to signify approval of the data. If commands or sequences are disapproved for some reason, the whole process must be restarted. Recording data and decision history is important for traceability reasons. Given that many steps and people are involved in this process, an easily accessible software tool for managing the process is vital to reducing human error which could result in uplinking incorrect data to the spacecraft. An uplink summary generator called ULSGEN was developed to assist this uplink content approval process. ULSGEN generates a web-based summary of uplink file content and provides an online review process. Spacecraft operations personnel view this summary as a final check before actual radiation of the uplink data. .

  12. Expression of sodium channel SNS/PN3 and ankyrin(G) mRNAs in the trigeminal ganglion after inferior alveolar nerve injury in the rat.

    PubMed

    Bongenhielm, U; Nosrat, C A; Nosrat, I; Eriksson, J; Fjell, J; Fried, K

    2000-08-01

    The inferior alveolar nerve is a sensory branch of the trigeminal nerve that is frequently damaged, and such nerve injuries can give rise to persistent paraesthesia and dysaesthesia. The mechanisms behind neuropathic pain following nerve injury is poorly understood. However, remodeling of voltage-gated sodium channels in the neuronal membrane has been proposed as one possible mechanism behind injury-induced ectopic hyperexcitability. The TTX-resistant sodium channel SNS/PN3 has been implicated in the development of neuropathic pain after spinal nerve injury. We here study the effect of chronic axotomy of the inferior alveolar nerve on the expression of SNS/PN3 mRNA in trigeminal sensory neurons. The organization of sodium channels in the neuronal membrane is maintained by binding to ankyrin, which help link the sodium channel to the membrane skeleton. Ankyrin(G), which colocalizes with sodium channels in the initial segments and nodes of Ranvier, and is necessary for normal neuronal sodium channel function, could be essential in the reorganization of the axonal membrane after nerve injury. For this reason, we here study the expression of ankyrin(G) in the trigeminal ganglion and the localization of ankyrin(G) protein in the inferior alveolar nerve after injury. We show that SNS/PN3 mRNA is down-regulated in small-sized trigeminal ganglion neurons following inferior alveolar nerve injury but that, in contrast to the persistent loss of SNS/PN3 mRNA seen in dorsal root ganglion neurons following sciatic nerve injury, the levels of SNS/PN3 mRNA appear to normalize within a few weeks. We further show that the expression of ankyrin(G) mRNA also is downregulated after nerve lesion and that these changes persist for at least 13 weeks. This decrease in the ankyrin(G) mRNA expression could play a role in the reorganization of sodium channels within the damaged nerve. The changes in the levels of SNS/PN3 mRNA in the trigeminal ganglion, which follow the time course for

  13. Trends in Laboratory Diagnostic Methods in Periodontology.

    PubMed

    Bolerázska, Beáta; Mareková, Mária; Markovská, Neda

    2016-01-01

    This work presents a summary of current knowledge on the laboratory diagnosis of periodontitis. It focuses on the theoretical foundations and is supplemented with new knowledge. It subsequently describes specifically the laboratory diagnosis methods of periodontitis: the protein expression of inflammation, oral microbiology and molecular diagnostics. Periodontitis is a serious disease worldwide and its confirmed association with systemic diseases means its severity is increasing. Its laboratory diagnosis has the potential to rise to the level of clinical and diagnostic imaging. The transfer of diagnostic methods from laboratory to clinical use is increasingly used in the prevention and monitoring of the exacerbation and treatment of periodontal disease, as well as of its impact on systemic disease.

  14. A facile one-pot hydrothermal method to produce SnS2/reduced graphene oxide with flake-on-sheet structures and their application in the removal of dyes from aqueous solution.

    PubMed

    Bian, Xiujie; Lu, Xiaofeng; Xue, Yanpeng; Zhang, Chengcheng; Kong, Lirong; Wang, Ce

    2013-09-15

    In this article, we report a novel one-pot synthesis of SnS2/reduced graphene oxide (rGO) flake-on-sheet nanocomposites via in situ reduction of graphene oxide (GO) by Sn(2+) under hydrothermal conditions. The morphology and structure of the obtained product were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction instrument (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The adsorption characteristics of the SnS2/rGO nanocomposites were examined using an organic dye Rhodamine B (RhB) as adsorbate. SnS2/rGO exhibited superior adsorption behavior for RhB. The adsorption kinetics and adsorption isotherm were investigated. The adsorption of RhB by SnS2/rGO was well fitted to the Langmuir isotherm model, and the resultant kinetic data were well described by pseudo-second-order model.

  15. Diagnostic Algorithm Benchmarking

    NASA Technical Reports Server (NTRS)

    Poll, Scott

    2011-01-01

    A poster for the NASA Aviation Safety Program Annual Technical Meeting. It describes empirical benchmarking on diagnostic algorithms using data from the ADAPT Electrical Power System testbed and a diagnostic software framework.

  16. Prenatal Genetic Diagnostic Tests

    MedlinePlus

    ... Education & Events Advocacy For Patients About ACOG Prenatal Genetic Diagnostic Tests Home For Patients Search FAQs Prenatal ... Pamphlets - Spanish FAQ164, September 2016 PDF Format Prenatal Genetic Diagnostic Tests Pregnancy What is prenatal genetic testing? ...

  17. Diagnostics for ITER

    SciTech Connect

    Donne, A. J. H.; Hellermann, M. G. von; Barnsley, R.

    2008-10-22

    After an introduction into the specific challenges in the field of diagnostics for ITER (specifically high level of nuclear radiation, long pulses, high fluxes of particles to plasma facing components, need for reliability and robustness), an overview will be given of the spectroscopic diagnostics foreseen for ITER. The paper will describe both active neutral-beam based diagnostics as well as passive spectroscopic diagnostics operating in the visible, ultra-violet and x-ray spectral regions.

  18. LEAP 1992: Conference summary

    SciTech Connect

    Dover, C.B.

    1992-12-01

    We present a summary of the many new results in antiproton ([bar p]) physics presented at the LEAP '92 conference, in the areas of meson spectroscopy, [bar N]N scattering, annihilation and spin observables, strangeness and charm production, [bar N] annihilation in nuclei, atomic physics with very low energy [bar p]'s, the exploration of fundamental symmetries and interactions with [bar p] (CP, T, CPT, gravitation), and the prospects for new [bar p] facilities at ultralow energies or energies above the LEAR regime ([ge] 2 GeV/c).

  19. LEAP 1992: Conference summary

    SciTech Connect

    Dover, C.B.

    1992-12-01

    We present a summary of the many new results in antiproton ({bar p}) physics presented at the LEAP `92 conference, in the areas of meson spectroscopy, {bar N}N scattering, annihilation and spin observables, strangeness and charm production, {bar N} annihilation in nuclei, atomic physics with very low energy {bar p}`s, the exploration of fundamental symmetries and interactions with {bar p} (CP, T, CPT, gravitation), and the prospects for new {bar p} facilities at ultralow energies or energies above the LEAR regime ({ge} 2 GeV/c).

  20. IAU Symposium 317 Summary

    NASA Astrophysics Data System (ADS)

    Gratton, Raffaele G.

    2016-08-01

    The assembly of the halo yields fundamental information on the formation and evolution of galaxies: this was quite exhaustively discussed at this very important symposium. I present a brief personal summary of the meeting, outlining those points that I found more exciting and suggestive. I also remarked a few areas that were possibly not enough expanded. I found this research field extremely interesting and I think there are great expectations for new developments in the next few years, thanks to the new large spectroscopic surveys and the ESA GAIA satellite.

  1. Space Shuttle Missions Summary

    NASA Technical Reports Server (NTRS)

    Bennett, Floyd V.; Legler, Robert D.

    2011-01-01

    This document has been produced and updated over a 21-year period. It is intended to be a handy reference document, basically one page per flight, and care has been exercised to make it as error-free as possible. This document is basically "as flown" data and has been compiled from many sources including flight logs, flight rules, flight anomaly logs, mod flight descent summary, post flight analysis of mps propellants, FDRD, FRD, SODB, and the MER shuttle flight data and inflight anomaly list. Orbit distance traveled is taken from the PAO mission statistics.

  2. Summaries of Research 1984.

    DTIC Science & Technology

    1984-01-01

    34 -111.1.1 .U-T-r-’ Ln NAVAL MEDICAL N RESEARCH INSTITUTE * BETHESDA.f MARYLAND VkS I OF SUMMARIES OF RESEARCH 1984 WI R.L. SPHAR. CAPT. MC, US...Commanding Officer Naval Medical Research Institute -NAVAL MEDICAL RESEARCH AND DEVELOPMENT COMMAND -~ r ale; its * 86 10 01 153 KEY TO CITATIONS NMRI 83...PERFORMING ORGANIZATION 6b OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Naval Medical Research (if applicable) Institute Naval Medical Command 6c

  3. National water summary available

    NASA Astrophysics Data System (ADS)

    In response to a Congressional Directive of 1977, the U.S. Geological Survey has been compiling reports discussing source, use, and disposition of surface water and groundwater in the United States. The latest, “National Water Summary 1987—Hydrologic Events and Water Supply and Use,” published as USGS Water Supply Paper 2350, by Jerry E. Carr, Edith B. Chase, Richard W. Paulson, and David W. Moody (compilers) is immediately available from local USGS Publications Offices or from the Books and Open-file Reports Section, U.S. Geological Survey, Federal Center, Box 25425, Denver, CO 80225; cost is $31.

  4. Atomistic Description of Thiostannate-Capped CdSe Nanocrystals: Retention of Four-Coordinate SnS4 Motif and Preservation of Cd-Rich Stoichiometry

    PubMed Central

    2016-01-01

    Colloidal semiconductor nanocrystals (NCs) are widely studied as building blocks for novel solid-state materials. Inorganic surface functionalization, used to displace native organic capping ligands from NC surfaces, has been a major enabler of electronic solid-state devices based on colloidal NCs. At the same time, very little is known about the atomistic details of the organic-to-inorganic ligand exchange and binding motifs at the NC surface, severely limiting further progress in designing all-inorganic NCs and NC solids. Taking thiostannates (K4SnS4, K4Sn2S6, K6Sn2S7) as typical examples of chalcogenidometallate ligands and oleate-capped CdSe NCs as a model NC system, in this study we address these questions through the combined application of solution 1H NMR spectroscopy, solution and solid-state 119Sn NMR spectroscopy, far-infrared and X-ray absorption spectroscopies, elemental analysis, and by DFT modeling. We show that through the X-type oleate-to-thiostannate ligand exchange, CdSe NCs retain their Cd-rich stoichiometry, with a stoichiometric CdSe core and surface Cd adatoms serving as binding sites for terminal S atoms of the thiostannates ligands, leading to all-inorganic (CdSe)core[Cdm(Sn2S7)yK(6y-2m)]shell (taking Sn2S76– ligand as an example). Thiostannates SnS44– and Sn2S76– retain (distorted) tetrahedral SnS4 geometry upon binding to NC surface. At the same time, experiments and simulations point to lower stability of Sn2S64– (and SnS32–) in most solvents and its lower adaptability to the NC surface caused by rigid Sn2S2 rings. PMID:25597625

  5. In situ capping for size control of monochalcogenides (ZnS, CdS, and SnS) nanocrystals produced by anaerobic metal-reducing bacteria

    SciTech Connect

    Jang, Gyoung Gug; Jacobs, Christopher B.; Ivanov, Ilia N.; Joshi, Pooran C.; Meyer, III, Harry M.; Kidder, Michelle; Armstrong, Beth L.; Datskos, Panos G.; Graham, David E.; Moon, Ji -Won

    2015-07-24

    Metal monochalcogenide quantum dot nanocrystals of ZnS, CdS and SnS were prepared by anaerobic, metal-reducing bacteria using in situ capping by oleic acid or oleylamine. Furthermore, the capping agent preferentially adsorbs on the surface of the nanocrystal, suppressing the growth process in the early stages, thus leading to production of nanocrystals with a diameter of less than 5 nm.

  6. Taking stress response out of the box: stability, discontinuity, and temperament effects on HPA and SNS across social stressors in mother-infant dyads.

    PubMed

    Laurent, Heidemarie K; Ablow, Jennifer C; Measelle, Jeffrey

    2012-01-01

    This study investigated continuity and stability of hypothalamic-pituitary-adrenal (HPA) and sympathetic nervous system (SNS) response measures in mother-infant dyads across 2 different types of social stress sessions. Synchrony of response trajectories across systems (SNS-HPA coordination) and partners (mother-infant attunement) was addressed, as were associations with infant temperament. Primiparous mothers and their 18-month-old infants (n = 86 dyads) completed an attachment stressor--Strange Situation (Ainsworth, Blehar, Waters, & Wall, 1978)--at Session 1 and challenge stressors--cleanup task and emotion task battery--at Session 2. Mother and infant saliva samples collected to index pre-stress, stress, and post-stress response during each session were assayed for cortisol (HPA marker) and salivary alpha-amylase (sAA; SNS marker). Multilevel modeling of cortisol/sAA trajectories across sessions revealed rank-order stability in mother/infant stress measures but discontinuity in absolute levels; cortisol trajectories were higher during attachment stress, and sAA trajectories were higher during challenge stress. Varying degrees of mother-infant attunement were found across sessions/systems. Infant surgency predicted higher stress measures, and negative affect and effortful control predicted lower stress measures, though associations depended on session/system. Findings are discussed in terms of advancing a multisystemic, contextual definition of developing stress responsiveness.

  7. Syntheses of Cu2SnS3 and Cu2ZnSnS4 nanoparticles with tunable Zn/Sn ratios under multibubble sonoluminescence conditions.

    PubMed

    Park, Jongpil; Song, Miyeon; Jung, Won Mok; Lee, Won Young; Kim, Hanggeun; Kim, Youngkwon; Hwang, Chahwan; Shim, Il-Wun

    2013-08-07

    Cu2ZnSnS4 (CZTS) nanoparticles were synthesized by sonochemical reactions under multibubble sonoluminescence (MBSL) conditions. First, Cu2SnS3 (CTS) nanoparticles were synthesized by the sonochemical method with a 91.3% yield. Second, ZnS was coated on Cu2SnS3 nanoparticles by the same method. Then, they were transformed into CZTS nanoparticles of 90-300 nm diameter by heating them at 450 °C for 1 hour. The ratios between Zn and Sn could be controlled from 0.20 to 1.32 by adjusting the relative concentrations of Cu2SnS3 and ZnCl2. With relatively lower Zn : Sn ratios (0.20-0.41), there was a mixture of CTS and CZTS nanoparticles. The prepared nanoparticles show different band gaps from 1.19 to 1.52 eV depending on the zinc to tin ratio. In this sonochemical method without using any toxic or high temperature solvents, the specific stoichiometric element ratios in CZTS were controllable on demand and their experimental results were always reproducible in separate syntheses. The CZTS nanoparticles were investigated by using X-ray diffraction, a UV-Vis spectrophotometer, a scanning electron microscope, Raman spectroscopy, and a high resolution-transmission electron microscope.

  8. Intern Summary Reports

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Topics covered include: Probe Station Antenna Range; LERCIP 2004 Summary; L.E.R.C.I.P. Internship Summary; Hubble Space Telescope Bi-Stem Thermal Shield Analyses; GRABER - the Duct Tape of Space and JIMO Heat Conducting Foam; CDF and PDF Comparison Between Humacao, Puerto Rico and Florida; Development of the On-board Aircraft Network; Development of the Planar Inlet Design and Analysis Process (PINDAP); An Overview of My 2004 Summer Internship [Non-destructive Evaluation]; My Summer Experience as an Administrative Officer Assistant [in the Safety and Assurance Directorate Office]; Programming an Experiment Control System; Reducing the Cation Exchange Capacity of Lithium Clay to Form Better Dispersed; Polymer-Clay Nanocomposites; Feasibility of EB Welded Hastelloy X and Combination of Refractory Metals; My Work in the NASA Glenn History Office and Records Management Office; Education, Technology, and Media: A Peak into My Summer Internship at NASA Glenn Research Center in Cleveland, Ohio; [The Engineering and Technical Services Directorate at the Glenn Research Center]; Drinking Water Database; Design of an EXB Probe; and Texturing Carbon-carbon Composite Radiator Surfaces Utilizing Atomic Oxygen.

  9. Mineral Commodity Summaries 2011

    USGS Publications Warehouse

    ,

    2011-01-01

    Each chapter of the 2011 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2010 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is included in the two-page synopsis. Mineral Commodity Summaries 2011 contains new chapters on iron oxide pigments, wollastonite, and zeolites. The chapters on mica (natural), scrap and flake and mica (natural), sheet have been combined into a single chapter - mica (natural). Abbreviations and units of measure, and definitions of selected terms used in the report, are in Appendix A and Appendix B, respectively. "Appendix C - Reserves and Resources" has been divided into "Part A - Resource/Reserve Classification for Minerals" and "Part B - Sources of Reserves Data," including some information that was previously in this introduction. A directory of USGS minerals information country specialists and their responsibilities is Appendix D. The USGS continually strives to improve the value of its publications to users. Constructive comments and suggestions by readers of the MCS 2011 are welcomed.

  10. Summary of the 4th Nordic Symposium on Digital Pathology

    PubMed Central

    Lundström, Claes; Waltersson, Marie; Persson, Anders; Treanor, Darren

    2017-01-01

    The Nordic symposium on digital pathology (NDP) was created to promote knowledge exchange across stakeholders in health care, industry, and academia. In 2016, the 4th NDP installment took place in Linköping, Sweden, promoting development and collaboration in digital pathology for the benefit of routine care advances. This article summarizes the symposium, gathering 170 attendees from 13 countries. This summary also contains results from a survey on integrated diagnostics aspects, in particular radiology-pathology collaboration. PMID:28382222

  11. 76 FR 54193 - Fiscal Year 2012 Veterinary Import/Export, Diagnostic Services, and Export Certification for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ... Animal and Plant Health Inspection Service Fiscal Year 2012 Veterinary Import/Export, Diagnostic Services... Inspection Service, USDA. ACTION: Notice. SUMMARY: This notice pertains to user fees charged for Veterinary..., animal products, birds, germ plasm, organisms, and vectors; for certain veterinary diagnostic...

  12. Giant piezoelectricity of monolayer group IV monochalcogenides: SnSe, SnS, GeSe, and GeS

    NASA Astrophysics Data System (ADS)

    Fei, Ruixiang; Li, Wenbin; Li, Ju; Yang, Li

    2015-10-01

    We predict enormous, anisotropic piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe, and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their piezoelectric coefficients are about one to two orders of magnitude larger than those of other 2D materials, such as MoS2 and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique "puckered" C2v symmetry and electronic structure of monolayer group IV monochalcogenides. Given the achieved experimental advances in the fabrication of monolayers, their flexible character, and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  13. Giant piezoelectricity of monolayer group IV monochalcogenides: SnSe, SnS, GeSe, and GeS

    SciTech Connect

    Fei, Ruixiang; Yang, Li; Li, Wenbin; Li, Ju

    2015-10-26

    We predict enormous, anisotropic piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe, and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their piezoelectric coefficients are about one to two orders of magnitude larger than those of other 2D materials, such as MoS{sub 2} and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique “puckered” C{sub 2v} symmetry and electronic structure of monolayer group IV monochalcogenides. Given the achieved experimental advances in the fabrication of monolayers, their flexible character, and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  14. Monte-Carlo simulations of a high-resolution backscattering spectrometer on the SNS - Long Wavelength Target Station

    NASA Astrophysics Data System (ADS)

    Bordallo, H. N.; Herwig, K. W.

    2001-03-01

    It is proposed to build an inverse geometry spectrometer to provide extremely high energy resolution (0.2 μeV FWHM, elastic) at the Long Wavelength Target Station (LWTS) at SNS. The design employs mica analyzers in close to backscattering geometry (final neutron wavelength of 20 ÅAnalytical calculations and Monte Carlo simulations (using the McStas package) have been used to optimize the layout of individual components and to estimate the instrument performance. This design requires a long initial guide section of 63 m from moderator to sample in order to achieve the timing resolution necessary for the desired δω. The LWTS will provide the high flux of long wavelength neutrons at the requisite pulse rate required by the spectrometer design. The resolution of this spectrometer lies between that routinely achieved by spin echo techniques and the design goal of the high power target station backscattering spectrometer. Covering this niche in energy resolution will allow systematic studies over the large dynamic range required by many disciplines. Molecular biology, for example, often requires systematic studies of many similar molecules under slightly different conditions, requiring a large range of energy/timing resolutions for optimum study.

  15. Atom-Thin SnS2-xSex with Adjustable Compositions by Direct Liquid Exfoliation from Single Crystals.

    PubMed

    Yang, Zhanhai; Liang, Hui; Wang, Xusheng; Ma, Xinlei; Zhang, Tao; Yang, Yanlian; Xie, Liming; Chen, Dong; Long, Yujia; Chen, Jitao; Chang, Yunjie; Yan, Chunhua; Zhang, Xinxiang; Zhang, Xueji; Ge, Binghui; Ren, Zhian; Xue, Mianqi; Chen, Genfu

    2016-01-26

    Two-dimensional (2D) chalcogenide materials are fundamentally and technologically fascinating for their suitable band gap energy and carrier type relevant to their adjustable composition, structure, and dimensionality. Here, we demonstrate the exfoliation of single-crystal SnS2-xSex (SSS) with S/Se vacancies into an atom-thin layer by simple sonication in ethanol without additive. The introduction of vacancies at the S/Se site, the conflicting atomic radius of sulfur in selenium layers, and easy incorporation with an ethanol molecule lead to high ion accessibility; therefore, atom-thin SSS flakes can be effectively prepared by exfoliating the single crystal via sonication. The in situ pyrolysis of such materials can further adjust their compositions, representing tunable activation energy, band gap, and also tunable response to analytes of such materials. As the most basic and crucial step of the 2D material field, the successful synthesis of an uncontaminated and atom-thin sample will further push ahead the large-scale applications of 2D materials, including, but not limited to, electronics, sensing, catalysis, and energy storage fields.

  16. Recent performance of the SNS H{sup −} ion source and low-energy beam transport system

    SciTech Connect

    Stockli, Martin P. Ewald, K. D.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Tang, J.; Welton, R.

    2014-02-15

    Recent measurements of the H{sup −} beam current show that SNS is injecting about 55 mA into the RFQ compared to ∼45 mA in 2010. Since 2010, the H{sup −} beam exiting the RFQ dropped from ∼40 mA to ∼34 mA, which is sufficient for 1 MW of beam power. To minimize the impact of the RFQ degradation, the service cycle of the best performing source was extended to 6 weeks. The only degradation is fluctuations in the electron dump voltage towards the end of some service cycles, a problem that is being investigated. Very recently, the RFQ was retuned, which partly restored its transmission. In addition, the electrostatic low-energy beam transport system was reengineered to double its heat sinking and equipped with a thermocouple that monitors the temperature of the ground electrode between the two Einzel lenses. The recorded data show that emissions from the source at high voltage dominate the heat load. Emissions from the partly Cs-covered first lens cause the temperature to peak several hours after starting up. On rare occasions, the temperature can also peak due to corona discharges between the center ground electrode and one of the lenses.

  17. Plasma emission spectroscopy for operating and developing the Spallation Neutron Source (SNS) H{sup −} ion sources

    SciTech Connect

    Han, B. X. Welton, R. F.; Murray, S. N.; Pennisi, T. R.; Santana, M.; Stockli, M. P.

    2014-02-15

    A RF-driven, Cs-enhanced H{sup −} ion source feeds the SNS accelerator with a high current (typically >50 mA), ∼1.0 ms pulsed beam at 60 Hz. To achieve the persistent high current beam for several weeks long service cycles, each newly installed ion source undergoes a rigorous conditioning and cesiation processes. Plasma conditioning outgases the system and sputter-cleans the ion conversion surfaces. A cesiation process immediately following the plasma conditioning releases Cs to provide coverage on the ion conversion surfaces. The effectiveness of the ion source conditioning and cesiation is monitored with plasma emission spectroscopy using a high-sensitivity optical spectrometer. Plasma emission spectroscopy is also used to provide a means for diagnosing and confirming a failure of the insulating coating of the ion source RF antenna which is immersed in the plasma. Emissions of composition elements of the antenna coating material, Na emission being the most significant, drastically elevate to signal a failure when it happens. Plasma spectra of the developmental ion source with an AlN (aluminum nitrite) chamber and an external RF antenna are also briefly discussed.

  18. SNS junctions in nanowires with spin-orbit coupling: role of confinement and helicity on the sub-gap spectrum

    NASA Astrophysics Data System (ADS)

    Cayao, Jorge; Prada, Elsa; San-Jose, Pablo; Aguado, Ramón

    2015-03-01

    We study normal transport and the sub-gap spectrum of superconductor-normal-superconductor (SNS) junctions made of semiconducting nanowires with strong Rashba spin-orbit coupling. We focus, in particular, on the role of confinement effects in long ballistic junctions. In the normal regime, scattering at the two contacts gives rise to two distinct features in conductance, Fabry-Perot resonances and Fano dips. The latter arise in the presence of a strong Zeeman field B that removes a spin sector in the leads (helical leads), but not in the central region. Conversely, a helical central region between non-helical leads exhibits helical gaps of half-quantum conductance, with superimposed helical Fabry-Perot oscillations. These normal features translate into distinct subgap states when the leads become superconducting. In particular, Fabry-Perot resonances within the helical gap become parity-protected zero-energy states (parity crossings, related to Yu-Shiba-Rusinov bound states), well below the critical field Bc at which the superconducting leads become topological. As a function of Zeeman field or Fermi energy, these zero-modes oscillate around zero energy, forming characteristic loops, which evolve continuously into Majorana bound states as B exceeds Bc.

  19. SNS junctions in nanowires with spin-orbit coupling: Role of confinement and helicity on the subgap spectrum

    NASA Astrophysics Data System (ADS)

    Cayao, Jorge; Prada, Elsa; San-Jose, Pablo; Aguado, Ramón

    2015-01-01

    We study normal transport and the subgap spectrum of superconductor-normal-superconductor (SNS) junctions made of semiconducting nanowires with strong Rashba spin-orbit coupling. We focus, in particular, on the role of confinement effects in long ballistic junctions. In the normal regime, scattering at the two contacts gives rise to two distinct features in conductance: Fabry-Perot resonances and Fano dips. The latter arise in the presence of a strong Zeeman field B that removes a spin sector in the leads (helical leads), but not in the central region. Conversely, a helical central region between nonhelical leads exhibits helical gaps of half-quantum conductance, with superimposed helical Fabry-Perot oscillations. These normal features translate into distinct subgap states when the leads become superconducting. In particular, Fabry-Perot resonances within the helical gap become parity-protected zero-energy states (parity crossings), well below the critical field Bc at which the superconducting leads become topological. As a function of Zeeman field or Fermi energy, these zero modes oscillate around zero energy, forming characteristic loops, which evolve continuously into Majorana bound states as B exceeds Bc. The relation with the physics of parity crossings of Yu-Shiba-Rusinov bound states is discussed.

  20. The Viking project. [summary

    NASA Technical Reports Server (NTRS)

    Soffen, G. A.

    1977-01-01

    The Viking project launched two unmanned spacecraft to Mars in 1975 for scientific exploration with special emphasis on the search for life. Each spacecraft consisted of an orbiter and a lander. The landing sites were finally selected after the spacecraft were in orbit. Thirteen investigations were performed: three mapping experiments from the orbiter, one atmospheric investigation during the lander entry phase, eight experiments on the surface of the planet, and one using the spacecraft radio and radar systems. The experiments on the surface dealt principally with biology, chemistry, geology, and meteorology. Seventy-eight scientists have participated in the 13 teams performing these experiments. This paper is a summary of the project and an introduction to the articles that follow.

  1. TFTR diagnostic vacuum controller

    SciTech Connect

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller.

  2. Diagnostic Lumbar Puncture

    PubMed Central

    Doherty, Carolynne M; Forbes, Raeburn B

    2014-01-01

    Diagnostic Lumbar Puncture is one of the most commonly performed invasive tests in clinical medicine. Evaluation of an acute headache and investigation of inflammatory or infectious disease of the nervous system are the most common indications. Serious complications are rare, and correct technique will minimise diagnostic error and maximise patient comfort. We review the technique of diagnostic Lumbar Puncture including anatomy, needle selection, needle insertion, measurement of opening pressure, Cerebrospinal Fluid (CSF) specimen handling and after care. We also make some quality improvement suggestions for those designing services incorporating diagnostic Lumbar Puncture. PMID:25075138

  3. What Is Diagnostic Testing?

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  4. Automatic Generation of Conditional Diagnostic Guidelines.

    PubMed

    Baldwin, Tyler; Guo, Yufan; Syeda-Mahmood, Tanveer

    2016-01-01

    The diagnostic workup for many diseases can be extraordinarily nuanced, and as such reference material text often contains extensive information regarding when it is appropriate to have a patient undergo a given procedure. In this work we employ a three task pipeline for the extraction of statements indicating the conditions under which a procedure should be performed, given a suspected diagnosis. First, we identify each instance in the text where a procedure is being recommended. Next we examine the context around these recommendations to extract conditional statements that dictate the conditions under which the recommendation holds. Finally, corefering recommendations across the document are linked to produce a full recommendation summary. Results indicate that each underlying task can be performed with above baseline performance, and the output can be used to produce concise recommendation summaries.

  5. Automatic Generation of Conditional Diagnostic Guidelines

    PubMed Central

    Baldwin, Tyler; Guo, Yufan; Syeda-Mahmood, Tanveer

    2016-01-01

    The diagnostic workup for many diseases can be extraordinarily nuanced, and as such reference material text often contains extensive information regarding when it is appropriate to have a patient undergo a given procedure. In this work we employ a three task pipeline for the extraction of statements indicating the conditions under which a procedure should be performed, given a suspected diagnosis. First, we identify each instance in the text where a procedure is being recommended. Next we examine the context around these recommendations to extract conditional statements that dictate the conditions under which the recommendation holds. Finally, corefering recommendations across the document are linked to produce a full recommendation summary. Results indicate that each underlying task can be performed with above baseline performance, and the output can be used to produce concise recommendation summaries. PMID:28269823

  6. National NIF Diagnostic Program Fiscal Year 2002 Third Quarter Report

    SciTech Connect

    MacGowan, B

    2002-07-01

    Since October 2001, the development of the facility diagnostics for NIF has been funded by the NIF Director through the National NIF Diagnostic Program (NNDP). The current emphasis of the NNDP is on diagnostics for the early NIF quad scheduled to be available for experiment commissioning in FY03. During the past nine months, the NNDP has set in place processes for funding diagnostics, developing requirements for diagnostics, design reviews, and monthly status reporting. Work has been funded at Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), the Naval Research Laboratory (NRL), Sandia National Laboratories (SNL), and Bechtel Nevada at Los Alamos and Santa Barbara. There are no major technical risks with the early diagnostics. The main concerns relate to integration of the diagnostics into the facility; all such issues are being worked. This report is organized to show the schedule and budget status and a summary of Change Control Board actions for the past three months. The following sections then provide short descriptions of the status of each diagnostic. Where design reviews or requirements documents are cited, the documents are available on the Diagnostics file server or on request.

  7. Delinquency Prevention Works. Program Summary.

    ERIC Educational Resources Information Center

    Bilchik, Shay

    The Office of Juvenile Justice and Delinquency Prevention (OJJDP) compiled this summary in order to assist states and jurisdictions in their delinquency prevention efforts. The summary provides a synthesis of current information on a broad range of programs and strategies which seek to prevent delinquency. The theory of risk-focused prevention is…

  8. The formation of IRIS diagnostics. III. Near-ultraviolet spectra and images

    SciTech Connect

    Pereira, T. M. D.; Leenaarts, J.; De Pontieu, B.; Carlsson, M.; Uitenbroek, H. E-mail: jorritl@astro.uio.no E-mail: mats.carlsson@astro.uio.no

    2013-12-01

    The Mg II h and k lines are the prime chromospheric diagnostics of NASA's Interface Region Imaging Spectrograph (IRIS). In the previous papers of this series, we used a realistic three-dimensional radiative magnetohydrodynamics model to calculate the h and k lines in detail and investigated how their spectral features relate to the underlying atmosphere. In this work, we employ the same approach to investigate how the h and k diagnostics fare when taking into account the finite resolution of IRIS and different noise levels. In addition, we investigate the diagnostic potential of several other photospheric lines and near-continuum regions present in the near-ultraviolet (NUV) window of IRIS and study the formation of the NUV slit-jaw images. We find that the instrumental resolution of IRIS has a small effect on the quality of the h and k diagnostics; the relations between the spectral features and atmospheric properties are mostly unchanged. The peak separation is the most affected diagnostic, but mainly due to limitations of the simulation. The effects of noise start to be noticeable at a signal-to-noise ratio (S/N) of 20, but we show that with noise filtering one can obtain reliable diagnostics at least down to a S/N of 5. The many photospheric lines present in the NUV window provide velocity information for at least eight distinct photospheric heights. Using line-free regions in the h and k far wings, we derive good estimates of photospheric temperature for at least three heights. Both of these diagnostics, in particular the latter, can be obtained even at S/Ns as low as 5.

  9. Building Diagnostic Market Deployment - Final Report

    SciTech Connect

    Katipamula, Srinivas; Gayeski, N.

    2012-04-01

    The work described in this report was done as part of a Cooperative Research and Development Agreement (CRADA) between the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL) and KGS Building LLC (KGS). PNNL and KGS both believe that the widespread adoption of automated fault de4tection and diagnostic (AFDD) tools will result in significant reduction to energy and peak energy consumption. The report provides an introduction, and summary of the various tasks performed under the CRADA. The CRADA project had three major focus areas: 1) Technical Assistance for Whole Building Energy Diagnostician (WBE) Commercialization, 2) Market Transfer of the Outdoor Air/Economizer Diagnostician (OAE), and 3) Development and Deployment of Automated Diagnostics to Improve Large Commercial Building Operations.

  10. Epidemiology of and Diagnostic Strategies for Toxoplasmosis

    PubMed Central

    Dardé, Marie-Laure

    2012-01-01

    Summary: The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies. PMID:22491772

  11. Automotive Diagnostic Technologies.

    ERIC Educational Resources Information Center

    Columbus State Community Coll., OH.

    This document contains materials developed for and about the automotive diagnostic technologies tech prep program of the South-Western City Schools in Ohio. Part 1 begins with a map of the program, which begins with an automotive/diagnostic technologies program in grades 11 and 12 that leads to entry-level employment or a 2-year automotive…

  12. Rethinking the Discharge Summary: A Focus on Handoff Communication

    PubMed Central

    Lenert, Leslie A.; Sakaguchi, Farrant H.; Weir, Charlene R.

    2014-01-01

    The discharge summary is one of the most critical documents in medical care settings, but it is prone to systematic lapses that compromise the continuity of care. Discontinuity is fostered not only by incomplete inclusion of data (such as pending labs or medication reconciliations) but also by failure to document clinical reasoning and unfinished diagnostic workups. To correct these problems, the authors propose the Situation-Background-Assessment-Recommendation (SBAR) format for discharge summaries. SBAR is already used for handoffs the way Subjective-Objective-Assessment-Plan is for progress notes. The SBAR format supports the concise presentation of relevant information along with guidance for action. It shifts the paradigm and purpose of the discharge summary away from being a “Captain’s Log” (a historical record of the events, actions taken, and their consequences during hospitalization) towards being a handoff document (a tool for communication between health professionals aimed at insuring continuity of care.) To test SBAR as a template for discharge summaries, the authors have initiated a study to document the impact of the SBAR model on the quality of trainees’ thinking in discharge summaries. PMID:24448037

  13. Mineral commodity summaries 2014

    USGS Publications Warehouse

    ,

    2014-01-01

    Each chapter of the 2014 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2013 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is included in the two-page synopsis. Abbreviations and units of measure, and definitions of selected terms used in the report, are in Appendix A and Appendix B, respectively. “Appendix C—Reserves and Resources” includes “Part A—Resource/Reserve Classification for Minerals” and “Part B—Sources of Reserves Data.” A directory of USGS minerals information country specialists and their responsibilities is Appendix D. The USGS continually strives to improve the value of its publications to users. Constructive comments and suggestions by readers of the MCS 2014 are welcomed.

  14. Current Intelligence Bulletins: summaries

    SciTech Connect

    Not Available

    1986-07-24

    Summaries are provided for the 47 Current Intelligence Bulletins issued to date by NIOSH; any revisions in NIOSH policy made after a bulletin was issued are included. Subjects of the bulletins include the following: chloroprene; trichloroethylene; ethylene-dibromide; chrome pigment; asbestos exposure; hexamethylphosphoric-triamide; polychlorinated biphenyls; 4,4'-diaminodipheylmethane; chloroform; radon daughters; dimethylcarbamoyl-chloride; diethylcarbamoyl-chloride; explosive azide hazard; inorganic arsenic; nitrosamines; metabolic precursors of beta-naphtylamine; 2-nitropropane; acryonitrile; 2,4-diaminoanisole; tetrachloroethylene; trimellitic-anhydride; ethylene-thiourea; ethylene-dibromide and disulfiram, toxic interaction; direct blue 6, direct black 38, direct brown 95, benzidine derived dyes; ethylene-dichloride; NIAX catalyst ESN; chloroethanes, review of toxicity; vinyl halides, carcinogenicity; glycidyl ethers; epichlorohydrin; smoking and the occupational environment; arsine poisoning in the workplace; radiofrequency sealers and heaters; formaldehyde; ethylene-oxide; silica flour; ethylene-dibromide; vibration syndrome; glycol ethers; 2,3,7,8-tetrachlorodibenzo-p-dioxin; 1,3-butadiene; cadmium; monohalomethanes; dinitrotoluenes; polychlorinated biphenyls in electrical equipment fires or failures; methylene-chloride; and 4,4' methylenedianiline.

  15. Mineral commodity summaries 2013

    USGS Publications Warehouse

    ,

    2013-01-01

    Each chapter of the 2013 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2012 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is included in the two-page synopsis. Abbreviations and units of measure, and definitions of selected terms used in the report, are in Appendix A and Appendix B, respectively. “Appendix C—Reserves and Resources” includes “Part A—Resource/Reserve Classification for Minerals” and “Part B—Sources of Reserves Data.” A directory of USGS minerals information country specialists and their responsibilities is Appendix D. The USGS continually strives to improve the value of its publications to users. Constructive comments and suggestions by readers of the MCS 2013 are welcomed.

  16. Fertilizer summary data 1990

    SciTech Connect

    Berry, J.T.; Hargett, N.L.

    1991-05-01

    Fertilizer Summary Data, published biennially by the National Fertilizer and Environmental Research Center (NFERC), combines fertilizer application and consumption statistics, crop acreage, and farm income/expense data by state and region for the period 1970 through 1990. This sixteenth edition contains statistics on commercial fertilizers sold for farm and nonfarm use, fertilizer distribution by class, and the leading fertilizer grades. Fertilizers are classified as single- or multiple-nutrient materials. Single-nutrient fertilizers, such as anhydrous ammonia (82-0-0), contain only one primary plant nutrient. Multiple-nutrient fertilizers contain two or more plant nutrients and include the ammonium phosphates and grades manufactured by dry or fluid mixing or chemical processing. In some cases, States report materials used in blending multiple-nutrient fertilizers as single-nutrient ingredients lather than the final manufactured product. Fertilizer consumption statistics for 1970 through 1980 are from US Department of Agriculture annual reports. Annual consumption data for 1985 through 1990 are based on the tabulation of individual state fertilizer tonnage reports submitted annually to TVA for inclusion in the National record of fertilizer consumption, Commercial Fertilizers. Crop statistics, fertilizer application rates, and farm income and expense data are supplied by the National Agricultural Statistics Service and the Economic Research Service, USDA.

  17. Summary of Vulcan Calculations

    SciTech Connect

    Colvin, J.D.

    2000-03-23

    This is a summary of the results of my calculations compared to Elisabeth Wolfrum's data on the Vulcan imprint experiments. The material strength makes essentially no difference to the growth of perturbations seeded by the laser imprint. For the low-intensity case (30 J laser energy, beam intensity of 0.5 x 10{sup 12} W/cm{sup 2}) the thin (2 microns) Al foil melts quickly from the front (driven) surface and decompresses quickly from the back surface, so there is actually only a fraction of the foil that is solid and compressed, and then for only a short time. And this solid fraction is not accelerating much during this short time. In particular, the shock (which is at about 250 kbar when it is about half way through the foil) travels entirely through the foil in about 0.25 ns. At 0.3 ns the ablation front is 0.6 {micro}m in from the original position of the front surface, the next 0.6 {micro}m is melted, so only the back 0.8 {micro}m is solid and compressed. This solid portion, though, is not moving much; the place where the imprinted perturbations are growing is back at the ablation front, where the perturbations are clearly growing fluid-like. By 0.5 ns the entire foil is melted and decompressing from both ends. Thus, the actual foil distortion looks little different with and without strength.

  18. Diagnostics of Nanodusty Plasma

    NASA Astrophysics Data System (ADS)

    Greiner, Franko; Groth, Sebastian; Tadsen, Bejamin; Piel, Alexander

    2015-11-01

    The diagnostic of nanodusty plasmas, i.e. plasmas including nano-sized dust particles, is a challenging task. For both, the diagnostic of the nanodusty plasma itself, and the in-situ diagnostic of the nanoparticles, no standard diagnostic exist. Nanodust particle size and density can be estimated using light scattering techniques, namely kinetic Mie ellipsometry and extinction measurements. The charge of the nanoparticles can be estimated from the analysis of dust density waves (DDW). Parameters like the electron density, which give information about the plasma itself, may be deduced from the DDW analysis. We present detailed investigations on nanodust in a reactive Argon-Acetylene plasma created in an rf-driven parallel plate reactor at low pressure using the above mentioned portfolio of diagnostic. Funded by DFG under contract SFB TR-24/A2.

  19. Rayleigh Scattering Diagnostics Workshop

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard (Compiler)

    1996-01-01

    The Rayleigh Scattering Diagnostics Workshop was held July 25-26, 1995 at the NASA Lewis Research Center in Cleveland, Ohio. The purpose of the workshop was to foster timely exchange of information and expertise acquired by researchers and users of laser based Rayleigh scattering diagnostics for aerospace flow facilities and other applications. This Conference Publication includes the 12 technical presentations and transcriptions of the two panel discussions. The first panel was made up of 'users' of optical diagnostics, mainly in aerospace test facilities, and its purpose was to assess areas of potential applications of Rayleigh scattering diagnostics. The second panel was made up of active researchers in Rayleigh scattering diagnostics, and its purpose was to discuss the direction of future work.

  20. Sample size recalculation in sequential diagnostic trials.

    PubMed

    Tang, Liansheng Larry; Liu, Aiyi

    2010-01-01

    Before a comparative diagnostic trial is carried out, maximum sample sizes for the diseased group and the nondiseased group need to be obtained to achieve a nominal power to detect a meaningful difference in diagnostic accuracy. Sample size calculation depends on the variance of the statistic of interest, which is the difference between receiver operating characteristic summary measures of 2 medical diagnostic tests. To obtain an appropriate value for the variance, one often has to assume an arbitrary parametric model and the associated parameter values for the 2 groups of subjects under 2 tests to be compared. It becomes more tedious to do so when the same subject undergoes 2 different tests because the correlation is then involved in modeling the test outcomes. The calculated variance based on incorrectly specified parametric models may be smaller than the true one, which will subsequently result in smaller maximum sample sizes, leaving the study underpowered. In this paper, we develop a nonparametric adaptive method for comparative diagnostic trials to update the sample sizes using interim data, while allowing early stopping during interim analyses. We show that the proposed method maintains the nominal power and type I error rate through theoretical proofs and simulation studies.

  1. Recent performance and ignition tests of the pulsed SNS H{sup −} source for 1-MW neutron production

    SciTech Connect

    Stockli, Martin P. Han, B. X.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R. F.

    2015-04-08

    After acquiring several reliable spare targets, SNS ramped the beam power from 850 kW to 1.4 MW, which required an increase in H{sup −} beam pulse length from 0.88 to 1.0 ms at 60 Hz. This increase initially produced slow 2-MHz power ramp-ups and, after several weeks of uninterrupted operation, it produced plasma outages every time the pulse length was raised above ∼0.95 ms. Similar outages were previously observed towards the end of long service cycles, which were believed to indicate that the breakdown voltage of the high purity hydrogen started to exceed the induced electric fields. In 2011 the RF was reconfigured to start with 10 cycles of 1.96 MHz, which yielded the shortest H{sup −} beam rise times and apparently eliminated those plasma outages. The new, pulse-length dependent outages were eliminated by increasing the initial frequency to 1.985 MHz. However, careful frequency studies are unable to justify this frequency. In addition, the paper discusses the issues and solutions for the electron-dump voltage, which starts to sag and become unstable after several weeks of high current operation. At the request of the authors and the Proceedings Editor this article has been updated to include References 3–13, which were present in the author’s original submission but were lost during manuscript processing in the Proceedings Editor's office. The updated article was published on 5 May 2015.

  2. Evaporation Mechanism of Sn and SnS from Liquid Fe: Part III. Effect of C on Sn Removal

    NASA Astrophysics Data System (ADS)

    Jung, Sung-Hoon; Kang, Youn-Bae; Seo, Jeong-Do; Park, Joong-Kil; Choi, Joo

    2015-02-01

    To understand the effect of C on Sn evaporation from liquid iron in the view of ferrous scrap recycling, the evaporation of Sn from various liquid Fe-C-S-Sn alloys was experimentally investigated. A series of gas-liquid reactions was carried out at 1873 K (1600 °C) using an electromagnetic levitation melting technique, where mass transfers in gas phase and liquid phase did not significantly affect the reaction rate. It was found that CS2(g) is a major gas species evaporating from Fe-C-S alloy (initial S content [pct S]0: 0.028 to 0.502 mass pct), and Fe-C-S-Sn alloy ([pct S]0: 0.063 to 0.560 mass pct), thereby competing with SnS for S in the liquid alloy. A model equation for the evaporation rate of CS2(g) was established using the experimental data for the Fe-C-S alloys. The chemical reaction rate constant for the CS2(g) evaporation () was obtained as 4.24 × 10-12 m7 mol-2 s-1, and the residual rate constant () was 4.24 × 10-16 m7 mol-2 s-1, both at 1873 K (1600 °C). Roll of C on the evaporation of Sn in Fe-C-Sn alloy was confirmed to be the increase of activity coefficient of Sn. By taking into account (1) the evaporation of Sn(g), SnS(g), and CS2(g), and (2) the increasing activity coefficient of Sn and S by C, a comprehensive model for the evaporation rate of Sn and S in the Fe-C-Sn-S alloy was developed. The calculation results by the developed model in the present study showed good agreement with the experimental results. Some applications of the current model are presented in the view of increasing the Sn removal rate.

  3. Polyethylene glycol-assisted growth of Cu2SnS3 promising absorbers for thin film solar cell applications

    NASA Astrophysics Data System (ADS)

    Kahraman, S.; Çetinkaya, S.; Yaşar, S.; Bilican, İ.

    2014-09-01

    In this paper, we report, for the first time, the results of the polyethylene glycol- (PEG) assisted preparation and characterization of high-quality and well-crystallized Cu2SnS3 (CTS) thin films obtained using sol-gel spin-coating method and a subsequent annealing in a sulphur atmosphere. Structural, morphological, compositional, electrical and optical investigations were carried out. The X-ray diffraction patterns of the samples proved the polycrystalline nature and preferred crystallization of the films. No peak referring to other binary or ternary phases were detected in the patterns. The intensity of the preferred orientation and crystallite size of the films increased with increasing PEG content. This trend yielded an improvement in photo-transient currents of the PEG-assisted growth of CTS films. The scanning electron microscopy images revealed that the CTS films have continuous, dense and agglomeration-like morphology. Through energy dispersive X-ray spectroscopy studies, it has been deduced that the samples consist of Cu, Sn and S of which atomic percentages were consistent with Cu/Sn and S/metal initial ratios. The agglomerated morphology of the samples has been attributed to increasing PEG content. A remarkable enhancement was observed in photo-transient currents of p-n junction of the produced films along with increasing PEG content. Through resistivity-temperature measurements, three impurity level electrical activation energy values for each film were found. Optical band gap values of the films were estimated via absorbance-wavelength behaviours and decreased with increasing PEG content. It has been revealed that PEG-assisted growth of CTS thin films is a promising way to improve its photovoltaic characteristics.

  4. Synthesis, Electrical Conductivity, and Crystal Structure of Cu 4Sn 7S 16and Structure Refinement of Cu 2SnS 3

    NASA Astrophysics Data System (ADS)

    Chen, Xue-an; Wada, Hiroaki; Sato, Akira; Mieno, Masahiro

    1998-08-01

    Single crystals of Cu 4Sn 7S 16and Cu 2SnS 3were prepared by the conventional solid state reaction method. Their crystal structures were determined from single-crystal X-ray data. Cu 4Sn 7S 16is of a new structure type with rhombohedral symmetry: R-3 m, a=7.372(1), c=36.010(7) Å, Z=3, R=0.018 for 522 structure factors and 36 variable parameters. Its crystal structure may be described as a defect variant of the spinel-type. In the unit cell, 3/4 of the tetrahedral sites and 1/8 of the octahedral sites are occupied by Cu +, while 7/8 of the octahedral sites are occupied by Sn 4+ions. The compound can therefore be formulated as (Cu 0.75□ 0.25)(Sn 1.75Cu 0.25)S 4. Cu 2SnS 3has the unit cell formula Cu 2.665(7)Sn 1.335(7)S 4( Z=2) and it is isotypic with the tetragonal stannite [Cu 2(Fe, Zn)SnS 4] structure: I-42 m, a=5.413(1), c=10.824(1) Å, R=0.030 for 281 reflections and 16 variables. In the case of Cu 2SnS 3, the positions of the Cu and Sn atoms of stannite are occupied by the composite atoms M1 [43.6(2) at.% Sn+56.4(2) at.% Cu] and M2 [46.3(3) at.% Sn+53.7(3) at.% Cu], respectively, while those of the (Fe, Zn) atoms are replaced by only Cu atoms. Electrical conductivity measurements confirm the expected semiconducting behavior of Cu 4Sn 7S 16, and XPS analysis reveals the presence of only Cu +in Cu 4Sn 7S 16.

  5. Characterization of a Novel Melanocortin Receptor-Containing Node in the SNS Outflow Circuitry to Brown Adipose Tissue Involved in Thermogenesis1

    PubMed Central

    Vaughan, C.H.; Shrestha, Y.B.; Bartness, T.J.

    2012-01-01

    The melanocortins (MC) can affect interscapular brown adipose tissue (IBAT) thermogenesis via its sympathetic nervous system (SNS) innervation. We chose a site of high MC4-receptor (MC4-R) mRNA co-localization with SNS outflow neurons to IBAT, the subzona incerta (subZI) to test whether IBAT thermogenesis could be increased or decreased. We first performed immunohistochemical characterization of the subZI and found neurons and/or fibers in this area positive for melanin concentrating hormone, oxytocin, arginine vasopressin, agouti-related protein and alpha-melanocyte stimulating hormone. Functional characterization of the subZI was tested via site-specific microinjections. The MC3/4-R agonist, melanotan II [MTII (0.025, 0.05 and 0.075 nmol)], and specific MC4-R agonist (cyclo [ß-Ala-His-D-Phe-Arg-Trp-Glu]-NH2; 0.024 nmol) both significantly increased IBAT temperature (TIBAT) and pretreatment with the MC4R antagonist, HS024 (0.072 nmol) blocked the MC4-R agonist-induced increased TIBAT in conscious, freely moving Siberian hamsters. Injection of the MC4-R antagonist alone significantly decreased TIBAT up to 3 h post injection. Collectively, these results highlight the identification of a brain area that possesses high concentrations of MC4-R mRNA and SNS outflow neurons to IBAT that has not been previously reported to be involved in the control of TIBAT. These results add to previously identified neural nodes that are components of the central circuits controlling thermogenesis. PMID:21802070

  6. Diagnostics on Z (invited)

    NASA Astrophysics Data System (ADS)

    Nash, T. J.; Derzon, M. S.; Chandler, G. A.; Fehl, D. L.; Leeper, R. J.; Porter, J. L.; Spielman, R. B.; Ruiz, C.; Cooper, G.; McGurn, J.; Hurst, M.; Jobe, D.; Torres, J.; Seaman, J.; Struve, K.; Lazier, S.; Gilliland, T.; Ruggles, L. A.; Simpson, W. A.; Adams, R.; Seaman, J. A.; Wenger, D.; Nielsen, D.; Riley, P.; French, R.; Stygar, B.; Wagoner, T.; Sanford, T. W. L.; Mock, R.; Asay, J.; Hall, C.; Knudson, M.; Armijo, J.; McKenney, J.; Hawn, R.; Schroen-Carey, D.; Hebron, D.; Cutler, T.; Dropinski, S.; Deeney, C.; LePell, P. D.; Coverdale, C. A.; Douglas, M.; Cuneo, M.; Hanson, D.; Bailey, J. E.; Lake, P.; Carlson, A.; Wakefield, C.; Mills, J.; Slopek, J.; Dinwoodie, T.; Idzorek, G.

    2001-01-01

    The 100 ns, 20 MA pinch-driver Z is surrounded by an extensive set of diagnostics. There are nine radial lines of sight set at 12° above horizontal and each of these may be equipped with up to five diagnostic ports. Instruments routinely fielded viewing the pinch from the side with these ports include x-ray diode arrays, photoconducting detector arrays, bolometers, transmission grating spectrometers, time-resolved x-ray pinhole cameras, x-ray crystal spectrometers, calorimeters, silicon photodiodes, and neutron detectors. A diagnostic package fielded on axis for viewing internal pinch radiation consists of nine lines of sight. This package accommodates virtually the same diagnostics as the radial ports. Other diagnostics not fielded on the axial or radial ports include current B-dot monitors, filtered x-ray scintillators coupled by fiber optics to streak cameras, streaked visible spectroscopy, velocity interferometric system for any reflector, bremsstrahlung cameras, and active shock breakout measurement of hohlraum temperature. The data acquisition system is capable of recording up to 500 channels and the data from each shot is available on the Internet. A major new diagnostic presently under construction is the BEAMLET backlighter. We will briefly describe each of these diagnostics and present some of the highest-quality data from them.

  7. Cable Diagnostic Focused Initiative

    SciTech Connect

    Hartlein, R.A.; Hampton, R.N.

    2010-12-30

    This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

  8. Melioidosis Diagnostic Workshop, 20131

    PubMed Central

    AuCoin, David; Baccam, Prasith; Baggett, Henry C.; Baird, Rob; Bhengsri, Saithip; Blaney, David D.; Brett, Paul J.; Brooks, Timothy J.G.; Brown, Katherine A.; Chantratita, Narisara; Cheng, Allen C.; Dance, David A.B.; Decuypere, Saskia; Defenbaugh, Dawn; Gee, Jay E.; Houghton, Raymond; Jorakate, Possawat; Lertmemongkolchai, Ganjana; Limmathurotsakul, Direk; Merlin, Toby L.; Mukhopadhyay, Chiranjay; Norton, Robert; Peacock, Sharon J.; Rolim, Dionne B.; Simpson, Andrew J.; Steinmetz, Ivo; Stoddard, Robyn A.; Stokes, Martha M.; Sue, David; Tuanyok, Apichai; Whistler, Toni; Wuthiekanun, Vanaporn; Walke, Henry T.

    2015-01-01

    Melioidosis is a severe disease that can be difficult to diagnose because of its diverse clinical manifestations and a lack of adequate diagnostic capabilities for suspected cases. There is broad interest in improving detection and diagnosis of this disease not only in melioidosis-endemic regions but also outside these regions because melioidosis may be underreported and poses a potential bioterrorism challenge for public health authorities. Therefore, a workshop of academic, government, and private sector personnel from around the world was convened to discuss the current state of melioidosis diagnostics, diagnostic needs, and future directions. PMID:25626057

  9. First-principles study of defect formation in the photovoltaic semiconductor Cu2SnS3 for comparison with Cu2ZnSnS4 and CuInSe2

    NASA Astrophysics Data System (ADS)

    Nishihara, Hironori; Maeda, Tsuyoshi; Shigemi, Akio; Wada, Takahiro

    2016-04-01

    The formation energies of neutral Cu, Sn, and S vacancies in monoclinic Cu2SnS3 were calculated by first-principles pseudopotential calculations using plane-wave basis functions in typical points in a schematic ternary phase diagram of a Cu-Sn-S system. The formation energy of a Cu atom vacancy in Cu2SnS3 under the Cu-poor condition has been calculated to be 0.23 eV, which is considerably smaller than those of Sn and S vacancies in Cu2SnS3. The results have been compared with those in Cu2SnZnS4 and CuInSe2 calculated with the same version of program code. The formation energy of a Cu atom vacancy in Cu2SnS3 under the Cu-poor condition is smaller than those for Cu2SnZnS4 (0.40 eV) and CuInSe2 (0.50 eV). The results indicate that Cu vacancies are easily formed in Cu2SnS3 under the Cu-poor condition as is the case with Cu2ZnSnS4 and CuInSe2. In this respect, Cu2SnS3 has the appropriate character of a light-absorbing material for thin-film solar cells, as is the case with Cu2ZnSnS4 and CuInSe2.

  10. Summary of The History Manifesto.

    PubMed

    Jacobs, Noortje

    2016-06-01

    This essay provides a brief, impartial summary of some main points of The History Manifesto, of the debate among historians that it has engendered, and of its connection to previous debates in and about the history of the sciences.

  11. No more summaries for wonks

    NASA Astrophysics Data System (ADS)

    Black, Richard

    2015-04-01

    IPCC assessments present an unparalleled opportunity for climate science to speak directly to power. Re-thinking the summaries written for policymakers would enable scientists to communicate far more effectively with political leaders and the public.

  12. Long term performance session summary

    SciTech Connect

    Hanauer, S.

    1996-05-01

    This paper presents brief summaries of reports given on plutonium disposal. Topics include: performance of waste forms; glass leaching; ceramic leaching; safeguards and security issues; safeguards of vitrification; and proliferation risks of geologic disposal.

  13. 40 CFR 25.8 - Responsiveness summaries.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Responsiveness Summaries prepared by agencies receiving EPA financial assistance shall also include evaluations... responsiveness summary requirements, these analyses need only be prepared and submitted with the final...

  14. AdaNET executive summary

    NASA Technical Reports Server (NTRS)

    Digman, R. Michael

    1988-01-01

    The goal of AdaNET is to transfer existing and emerging software engineering technology from the Federal government to the private sector. The views and perspectives of the current project participants on long and short term goals for AdaNET; organizational structure; resources and returns; summary of identified AdaNET services; and the summary of the organizational model currently under discussion are presented.

  15. Reuse in Practice Workshop Summary

    DTIC Science & Technology

    1990-04-01

    FUNDING NUMERS Reuse in Practice Workshop Summary MDA 903 89 C 0003 T-R2-597.2 6. AUTHOR (S) James Baldo, Jr. 7. PERFORMING ORGANIZATION NAME(S) AND...written by the author , summaries of working groups written by the chairpersons and rapporteurs, and a collection of position papers submitted by the...Software Engineering Institute (SEI), Association for Computing Machinery (ACM), or the Strategic Defense Initiative Organization (SDIO). The author

  16. Radioactive diagnostic agent

    SciTech Connect

    Shigematsu, A.; Aihara, M.; Matsuda, M.; Suzuki, A.; Tsuya, A.

    1984-02-07

    A radioactive diagnostic agent for renal cortex, adrenal cortex, myocardium, brain stem, spinal nerve, etc., which comprises as an essential component monoiodoacetic acid wherein the iodine atom is radioactive.

  17. Fermilab recycler diagnostics

    SciTech Connect

    Martin Hu

    2001-07-24

    The Fermilab Recycler Ring is a permanent magnet storage ring for the storage and cooling of antiprotons. The following note describes the diagnostic tools currently available for commissioning, as well as the improvements and upgrades planned for the near future.

  18. Principles of plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Hutchinson, Ian H.

    The physical principles, techniques, and instrumentation of plasma diagnostics are examined in an introduction and reference work for students and practicing scientists. Topics addressed include basic plasma properties, magnetic diagnostics, plasma particle flux, and refractive-index measurements. Consideration is given to EM emission by free and bound electrons, the scattering of EM radiation, and ion processes. Diagrams, drawings, graphs, sample problems, and a glossary of symbols are provided.

  19. Laser fluorescence diagnostics

    NASA Astrophysics Data System (ADS)

    Kozlov, V. K.; Krasilnikov, D. M.; Turkin, V. V.

    1995-01-01

    This paper descsribes the development of an apparatus, method, and practical recommendation on using fluorescence diagnostics in alimentary-intestinal tract surgery and analyses of blood serum and plasma for investigating influence of various drug preparations on a human organism. The report of the firm Israel Aircraft Industries on the high efficiency of using fluorescent analysis in early diagnostics of rectum, lung, and breast cancer has stimulated our publication.

  20. Engineering Annual Summary 1999

    SciTech Connect

    Dimolitsas, S.; Gerich, C.

    2000-04-11

    a 100 percent data capture rate. came to an end. Within an intense three-month period, Engineering effectively transitioned its 150 employees working on this project to other Laboratory projects. We leveraged our competence in microsystems and biosciences to establish a robust technical presence in the field of biological and chemical weapons defense. This year, we saw successful operational tests of several hand-held versions of our analytical instruments. Concurrently, we saw our efforts in information technologies and medical devices pay off significantly, when both these areas grew robustly. In the operations area, Engineering underwent an important change in its technology investment strategy. In 1998, we consolidated our nine technical thrust areas into five Engineering Technology Centers and restructured these centers to form the Engineering Science and Technology Program, reporting directly to my office. In 1999, we completed the selection of four of the five Directors to lead each of these areas and moved from startup to true enterprise. This 1999 Summary highlights these five Centers.

  1. Engineering Annual Summary 1998

    SciTech Connect

    Dimolitsas, S

    1999-05-01

    Unlike most research and development laboratories, Lawrence Livermore National Laboratory (LLNL) is responsible for delivering production-ready designs. Unlike most industry, LLNL is responsible for R and D that must significantly increase the nation's security. This rare combination of production engineering expertise and national R and D agenda identifies LLNL as one of the few organizations today that conducts cutting-edge engineering on grand-scale problems, while facing enormous technical risk and undergoing diligent scrutiny of its budget, schedule, and performance. On the grand scale, cutting-edge technologies are emerging from our recent ventures into ''Xtreme Engineering{trademark}.'' Basically, we must integrate and extend technologies concurrently and then push them to their extreme, such as building very large structures but aligning them with extreme precision. As we extend these technologies, we push the boundaries of engineering capabilities at both poles: microscale and ultrascale. Today, in the ultrascale realm, we are building NIF, the world's largest laser, which demands one of the world's most complex operating systems with 9000 motors integrated through over 500 computers to control 60,000 points for every laser shot. On the other pole, we have fabricated the world's smallest surgical tools and the smallest instruments for detecting biological and chemical agents used by antiterrorists. Later in this Annual Summary, we highlight some of our recent innovations in the area of Xtreme Engineering, including large-scale computer simulations of massive structures such as major bridges to prepare retrofitting designs to withstand earthquakes. Another feature is our conceptual breakthrough in developing the world's fastest airplane, HyperSoar, which can reach anywhere in the planet in two hours at speeds of 6700 mph. In the last few years, Engineering has significantly pushed the technology in structural mechanics and micro-instrumentation. For example

  2. Research Update: Prediction of high figure of merit plateau in SnS and solid solution of (Pb,Sn)S

    NASA Astrophysics Data System (ADS)

    Hao, Shiqiang; Dravid, Vinayak P.; Kanatzidis, Mercouri G.; Wolverton, Christopher

    2016-10-01

    Direct conversion between thermal and electrical energy can be achieved by thermoelectric materials, which provide a viable route for power generation and solid state refrigeration. Here, we use a combination of energetic, electronic, and vibrational first-principles based results to predict the figure of merit performance in hole doped single crystals of SnS and (Pb,Sn)S. We find high ZT values for both materials, specifically for (Pb,Sn)S along the b-axis. Both SnS and (Pb,Sn)S have excellent power factors when doped, due to a combination of increased electrical conductivity (due to doping) and a significantly enhanced Seebeck coefficient obtained by a doping-induced multiband effect. Anharmonic phonon calculations combined with a Debye-Calloway model show that the lattice thermal conductivity of both compounds is low, due to intrinsic anharmonicity, and is lowered further by the random, solid solution nature of the cation sublattice of (Pb,Sn)S. (Pb,Sn)S exhibits a high ZT plateau ranging from 1.3 at 300 K to 1.9 at 800 K. The overall ZT of the hole doped (Pb,Sn)S crystals is predicted to outperform most of the current state-of-the-art thermoelectric sulfide materials.

  3. Peculiarities in electrical and optical properties of Cu2Zn1- x Mn x SnS4 films obtained by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Orletskii, I. G.; Mar'yanchuk, P. D.; Solovan, M. N.; Maistruk, E. V.; Kozyarskii, D. P.

    2016-03-01

    Thin films of Cu2Zn1- x Mn x SnS4 (0 ≤ x ≤ 1) solid solutions have been obtained for the first time by the spray pyrolysis of aqueous salt solutions (copper, zinc, manganese, and tin chlorides and thiourea) at a temperature of T S = 563 K. The films possess specific electric conductivities within σ ≈ 35-422 Ω-1 cm-1 and optical bandgap width E g op that increases with the manganese content from 1.54 eV ( x = 0) to 2.25 eV ( x = 1). Electrical and optical properties of the obtained films have been studied and analyzed based on a model of polycrystalline materials with grain boundaries. The energy barriers Eb between grains have been determined. The dependence of the bandgap of Cu2Zn1- x Mn x SnS4 (0 ≤ x ≤ 1) solid solutions on the composition has been established using the results of measurements of the optical transmission and absorption coefficients.

  4. Determination of sulfur in crude oil using high-resolution continuum source molecular absorption spectrometry of the SnS molecule in a graphite furnace.

    PubMed

    Cadorim, Heloisa R; Pereira, Éderson R; Carasek, Eduardo; Welz, Bernhard; de Andrade, Jailson B

    2016-01-01

    An analytical method for the determination of sulfur, as the tin mono-sulfide (SnS) molecule, in crude oil using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) has been developed. The molecular absorbance of the SnS has been measured using the wavelength at 271.624 nm and the crude oil samples were prepared as micro-emulsions due to their high viscosity. Several chemical modifiers (Ir, Pd, Ru, Zr) were tested and palladium was chosen, because it exhibited the best performance. The heating program was optimized by comparing the pyrolysis and vaporization curves obtained for an aqueous sulfur standard and a micro-emulsion of a crude oil certified reference material (CRM). The optimum pyrolysis and vaporization temperatures were found to be 600 and 2000°C, respectively. The limit of detection and the characteristic mass using micro-emulsion analysis of crude oil samples were 5.8 and 13.3 ng S. Accuracy and precision of the method has been evaluated using two crude oil CRM (NIST 2721 and NIST 2722), showing good agreement with the informed or certified values.

  5. Economic Effects of the Spallation Neutron Source (SNS) and the Joint Institute for Neutron Sciences (JINS) on the State of Tennessee

    SciTech Connect

    Univ of TN, Center for Business Research

    2002-12-18

    This report provides an analysis of the economic impacts arising from the construction and operation of the Spallation Neutron Source (SNS) and Joint Institute of Neutron Science (JINS) facilities on the State of Tennessee. The study was conducted by the Center for Business and Economic Research (CBER) at the University of Tennessee, Knoxville, in cooperation with the Oak Ridge National Laboratory (ORNL) and the Science Alliance at UTK. Estimates provided are based on data provided by ORNL and the Office of Research at UTK. The estimates contained in the report quantify the income, employment, and sales tax revenue which will be generated by the activities of the SNS and JINS by accounting for the (1) direct impacts, those arising directly from the expenditures for the construction and operation of the facilities; (2) indirect impacts, those arising from the visitors to the facilities and from facility expenditures in Tennessee; and (3) multiplier impacts, those arising from the ripple effects created as new income is spent and respent in the state economy.

  6. Preparation and characterization of Cu2SnS3 ternary semiconductor nanostructures via the spray pyrolysis technique for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Adelifard, Mehdi; Bagheri Mohagheghi, Mohamad Mehdi; Eshghi, Hosein

    2012-03-01

    Thin films of Cu2SnS3 have been deposited by the spray pyrolysis technique. Various Sn/Cu molar ratios (from 0.0 to 1.0) were applied, which allowed the study of the copper tin sulfide phase. Structural, morphological and compositional analyses have been carried out using x-ray diffraction, field emission scanning electron microscopy and energy dispersive spectroscopy. The pure CuS thin film showed the covellite phase with hexagonal crystal structure, and with increasing the Sn/Cu molar ratio, the films grown were crystallized with triclinic Cu2SnS3 ternary phase. Optical measurement analysis showed that the deposited layers have a relatively high absorption coefficient (~105 cm-1) in the visible spectrum, about one order of magnitude higher than in other published reports. Also these layers presented a reduction of about 1 eV in the values of band gap from 2.57 to 1.58 eV with an increment in the Sn/Cu molar ratio from 0.0 to 1.0. The electrical properties studies showed that all these samples are p-type semiconductors and the resistivity decreases with increasing the Sn/Cu molar ratio.

  7. Second harmonic generation response of the cubic chalcogenides Ba(6-x)Srx[Ag(4-y)Sn(y/4)](SnS4)4

    NASA Astrophysics Data System (ADS)

    Haynes, Alyssa S.; Liu, Te-Kun; Frazer, Laszlo; Lin, Jyun-Fan; Wang, Shuo-Yu; Ketterson, John B.; Kanatzidis, Mercouri G.; Hsu, Kuei-Fang

    2017-04-01

    We synthesized the barium/strontium solid solution sequence Ba6-xSrx[Ag(4-y)Sn(y/4)](SnS4)4 for nonlinear optical (NLO) applications in the infrared (IR) via a flux synthesis route. All title compounds are isotypic, crystallizing in the cubic space group I 4 ̅3d and are composed of a three-dimensional (3D) anionic framework of alternating corner-sharing SnS4 and AgS4 tetrahedra charge balanced by Ba and Sr. The shrinkage of Ba/Sr-S bond lengths causes the tetrahedra in the anionic framework to become more distorted, which results in a tunable band gap from 1.58 to 1.38 eV with increasing x values. The performance of the barium limit (x=0) is also superior to that of Sr (x=6), but surprisingly second harmonic generation (SHG) of the solid solution remains strong and is insensitive to the value of x over the range 0-3.8. Results show that the non-type-I phase-matched SHG produced by these cubic chalcogenides display intensities higher than the benchmark AgGaSe2 from 600 to 1000 nm.

  8. Does Writing Summaries Improve Memory for Text?

    ERIC Educational Resources Information Center

    Spirgel, Arie S.; Delaney, Peter F.

    2016-01-01

    In five experiments, we consistently found that items included in summaries were better remembered than items omitted from summaries. We did not, however, find evidence that summary writing was better than merely restudying the text. These patterns held with shorter and longer texts, when the text was present or absent during the summary writing,…

  9. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  10. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  11. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  12. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  13. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  14. Instrumentation Working Group Summary

    NASA Technical Reports Server (NTRS)

    Zaller, Michelle; Miake-Lye, Richard

    1999-01-01

    The Instrumentation Working Group compiled a summary of measurement techniques applicable to gas turbine engine aerosol precursors and particulates. An assessment was made of the limits, accuracy, applicability, and technology readiness of the various techniques. Despite advances made in emissions characterization of aircraft engines, uncertainties still exist in the mechanisms by which aerosols and particulates are produced in the near-field engine exhaust. To adequately assess current understanding of the formation of sulfuric acid aerosols in the exhaust plumes of gas turbine engines, measurements are required to determine the degree and importance of sulfur oxidation in the turbine and at the engine exit. Ideally, concentrations of all sulfur species would be acquired, with emphasis on SO2 and SO3. Numerous options exist for extractive and non-extractive measurement of SO2 at the engine exit, most of which are well developed. SO2 measurements should be performed first to place an upper bound on the percentage of SO2 oxidation. If extractive and non-extractive techniques indicate that a large amount of the fuel sulfur is not detected as SO2, then efforts are needed to improve techniques for SO3 measurements. Additional work will be required to account for the fuel sulfur in the engine exhaust. Chemical Ionization Mass Spectrometry (CI-MS) measurements need to be pursued, although a careful assessment needs to be made of the sampling line impact on the extracted sample composition. Efforts should also be placed on implementing non-intrusive techniques and extending their capabilities by maximizing exhaust coverage for line-of-sight measurements, as well as development of 2-D techniques, where feasible. Recommendations were made to continue engine exit and combustor measurements of particulates. Particulate measurements should include particle size distribution, mass fraction, hydration properties, and volatile fraction. However, methods to ensure that unaltered

  15. Revisiting Tversky's diagnosticity principle

    PubMed Central

    Evers, Ellen R. K.; Lakens, Daniël

    2013-01-01

    Similarity is a fundamental concept in cognition. In 1977, Amos Tversky published a highly influential feature-based model of how people judge the similarity between objects. The model highlights the context-dependence of similarity judgments, and challenged geometric models of similarity. One of the context-dependent effects Tversky describes is the diagnosticity principle. The diagnosticity principle determines which features are used to cluster multiple objects into subgroups. Perceived similarity between items within clusters is expected to increase, while similarity between items in different clusters decreases. Here, we present two pre-registered replications of the studies on the diagnosticity effect reported in Tversky (1977). Additionally, one alternative mechanism that has been proposed to play a role in the original studies, an increase in the choice for distractor items (a substitution effect, see Medin et al., 1995), is examined. Our results replicate those found by Tversky (1977), revealing an average diagnosticity-effect of 4.75%. However, when we eliminate the possibility of substitution effects confounding the results, a meta-analysis of the data provides no indication of any remaining effect of diagnosticity. PMID:25161638

  16. MJO Simulation Diagnostics

    SciTech Connect

    Waliser, D; Sperber, K; Hendon, H; Kim, D; Maloney, E; Wheeler, M; Weickmann, K; Zhang, C; Donner, L; Gottschalck, J; Higgins, W; Kang, I; Legler, D; Moncrieff, M; Schubert, S; Stern, W; Vitart, F; Wang, B; Wang, W; Woolnough, S

    2008-06-02

    The Madden-Julian Oscillation (MJO) interacts with, and influences, a wide range of weather and climate phenomena (e.g., monsoons, ENSO, tropical storms, mid-latitude weather), and represents an important, and as yet unexploited, source of predictability at the subseasonal time scale. Despite the important role of the MJO in our climate and weather systems, current global circulation models (GCMs) exhibit considerable shortcomings in representing this phenomenon. These shortcomings have been documented in a number of multi-model comparison studies over the last decade. However, diagnosis of model performance has been challenging, and model progress has been difficult to track, due to the lack of a coherent and standardized set of MJO diagnostics. One of the chief objectives of the US CLIVAR MJO Working Group is the development of observation-based diagnostics for objectively evaluating global model simulations of the MJO in a consistent framework. Motivation for this activity is reviewed, and the intent and justification for a set of diagnostics is provided, along with specification for their calculation, and illustrations of their application. The diagnostics range from relatively simple analyses of variance and correlation, to more sophisticated space-time spectral and empirical orthogonal function analyses. These diagnostic techniques are used to detect MJO signals, to construct composite life-cycles, to identify associations of MJO activity with the mean state, and to describe interannual variability of the MJO.

  17. Diagnostic dry bone histology in human paleopathology.

    PubMed

    de Boer, H H Hans; Van der Merwe, A E Lida

    2016-10-01

    Paleopathology is the study of trauma and disease as may be observed in ancient (human) remains. In contrast to its central role in current medical practice, microscopy plays a rather modest role in paleopathology. This is at least partially due to the differences between fresh and decomposed (i.e., skeletonized or "dry bone") tissue samples. This review discusses these differences and describes how they affect the histological analysis of paleopathological specimens. First, we provide a summary of some general challenges related to the histological analysis of palaeopathological specimens. Second, the reader is introduced in bone tissue histology and bone tissue dynamics. The remainder of the paper is dedicated to the diagnostic value of dry bone histology. Its value and limitations are illustrated by comparing several well-studied paleopathological cases with similar contemporary, clinical cases. This review illustrates that due to post-mortem loss of soft tissue, a limited number of disorders display pathognomonic features during histological analysis of skeletonized human remains. In the remainder of cases, histology may help to narrow down the differential diagnosis or is diagnostically unspecific. A comprehensive, multidisciplinary diagnostic approach therefore remains essential. Clin. Anat. 29:831-843, 2016. © 2016 Wiley Periodicals, Inc.

  18. Los Alamos x-ray characterization facilities for plasma diagnostics

    SciTech Connect

    Day, R.H.; Blake, R.L.; Stradling, G.L.; Trela, W.J.; Bartlett, R.J.

    1986-01-01

    A summary is given of characteristics of x-ray sources used by Los Alamos National Laboratory to calibrate various x-ray diagnostic packages and components. Included are D.C. sourcs in electron impact and fluorescence modes, a pulsed laser source for soft x rays with 100 ps time resolution, Febetron pulsed electron impact sources, and both EUV and x-ray synchrotron beamlines.

  19. Beamlet laser diagnostics

    SciTech Connect

    Burkhart, S.C.; Behrendt, W.C.; Smith, I.

    1996-06-01

    Beamlet is instrumented extensively to monitor the performance of the overall laser system and many of its subsystems. Beam diagnostics, installed in key locations, are used to fully characterize the beam during its propagation through the multipass cavity and the laser`s output section. This article describes the diagnostics stations located on Beamlet and discusses the design, calibration, and performance of the Beamlet calorimeters. The authors used Nova`s diagnostics packages to develop the Beamlet design to determine beam energy, spatial profile, temporal profile, and other beam parameters. Technologic improvements within the last several years in controls, charge-coupled device (CCD) cameras, and fast oscilloscopes have allowed the authors to obtain more accurate measurements on the Beamlet laser system. They briefly cover some of these techniques, including a description of their LabVIEW based data acquisition system.

  20. [Peripheral neuropathies: Diagnostic strategy].

    PubMed

    Magy, L

    2017-02-28

    Diagnosing a peripheral neuropathy is sometimes challenging, as the causes are diverse and the clinical pictures heterogeneous. Overall, diagnosing a patient with peripheral neuropathy will require some knowledge in almost every field of medicine. Therefore, it appears crucial to adopt a diagnostic strategy that is based on solid clinical and neurophysiological grounds. The present paper describes a three-step diagnostic strategy: (1) to delineate a clinico-pathologic entity from clinical and electrodiagnostic findings; (2) to propose a list of plausible causes based on step one, history and clinical context; (3) to use appropriate workup in order to determine the cause or mechanism of the neuropathy. The three steps of this diagnostic strategy necessitate a high level of expertise and interaction between physicians is highly desirable. Finally, an aggressive course and a severe impairment should lead to relentlessly look for a curable cause.

  1. [Molecular diagnostics in pathology].

    PubMed

    Stenzinger, A; Penzel, R; Endris, V; Weichert, W

    2013-05-01

    Tissue-based molecular diagnostics is a fast growing diagnostic field, which already complements morphologic classifications in many cases. Pathology based molecular diagnosis is performed almost exclusively on paraffin embedded material and always in conjunction with histopathology. Besides the classic field of tissue based detection of pathogenic organisms such as bacteria, viruses and fungi, molecular diagnostics of tumor tissue is one of the current hot topics in oncology. In this context the detection of predictive molecular biomarkers, such as specific mutations, allows patient stratification for individually tailored treatment strategies and thereby is one of the key components of individualized patient care in oncology. The rapidly growing number of clinically relevant predictive biomarkers together with impressive technical advances, specifically the development of massive parallel sequencing, will modify the care of patients with malignant diseases. Pathology, therefore, has returned in the very center of interdisciplinary patient care.

  2. ORION laser target diagnostics.

    PubMed

    Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P

    2012-10-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  3. Wind energy systems: program summary

    SciTech Connect

    1980-05-01

    The Federal Wind Energy Program (FWEP) was initiated to provide focus, direction and funds for the development of wind power. Each year a summary is prepared to provide the American public with an overview of government sponsored activities in the FWEP. This program summary describes each of the Department of Energy's (DOE) current wind energy projects initiated or renewed during FY 1979 (October 1, 1978 through September 30, 1979) and reflects their status as of April 30, 1980. The summary highlights on-going research, development and demonstration efforts and serves as a record of progress towards the program objectives. It also provides: the program's general management structure; review of last year's achievements; forecast of expected future trends; documentation of the projects conducted during FY 1979; and list of key wind energy publications.

  4. Summary Report of Working Group 6: Laser-Plasma Acceleration

    SciTech Connect

    Leemans, Wim P.; Downer, Michael; Siders, Craig

    2006-07-01

    A summary is given of presentations and discussions in theLaser-Plasma Acceleration Working Group at the 2006 Advanced AcceleratorConcepts Workshop. Presentation highlights include: widespreadobservation of quasi-monoenergetic electrons; good agreement betweenmeasured and simulated beam properties; the first demonstration oflaser-plasma acceleration up to 1 GeV; single-shot visualization of laserwakefield structure; new methods for measuring<100 fs electronbunches; and new methods for "machining" laser-plasma acceleratorstructures. Discussion of future direction includes: developing a roadmapfor laser-plasma acceleration beyond 1 GeV; a debate over injection andguiding; benchmarking simulations with improved wake diagnostics;petawatt laser technology for future laser-plasmaaccelerators.

  5. [Complex diagnostics of osteosarcomas].

    PubMed

    Muradov, Kh K; Sadykhova, G G

    2014-01-01

    It was analyzed the examination results of 156 patients with osteosarcoma. The data show that definition of histogenetic source, diagnostics and prognosis of treatment results are possible and expedient in case of analysis of signs reflecting tumor cells specificity. These signs may be determined by using of clinical parameters, X-ray imaging and light microscopy in case of moderately and highly differentiated sarcomas. Ample opportunities of flow citometry and immunohistochemistry allow to perform histogenetic identification, differential diagnostics and prognosis for low-grade sarcomas.

  6. Diagnostic hematology of reptiles.

    PubMed

    Stacy, Nicole I; Alleman, A Rick; Sayler, Katherine A

    2011-03-01

    The hematologic evaluation of reptiles is an indispensable diagnostic tool in exotic veterinary practice. The diversity of reptile species, their characteristic physiologic features, and effects of intrinsic and extrinsic factors present unique challenges for accurate interpretation of the hemogram. Combining the clinical presentation with hematologic findings provides valuable information in the diagnosis and monitoring of disease and helps guide the clinician toward therapy and further diagnostic testing. This article outlines the normal and pathologic morphology of blood cells of reptile species. The specific comparative aspects of reptiles are emphasized, and structural and functional abnormalities in the reptilian hemogram are described.

  7. SNS Injection Foil Experience

    SciTech Connect

    Cousineau, Sarah M; Galambos, John D; Kim, Sang-Ho; Ladd, Peter; Luck, Chris; Peters, Charles C; Polsky, Yarom; Shaw, Robert W; Macek, Robert James; Raparia, Deepak; Plum, Michael A

    2010-01-01

    The Spallation Neutron Source comprises a 1 GeV, 1.4 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H0 excited states created during the H charge exchange injection into the accumulator ring, the stripper foil is located inside one of the chicane dipoles. This has some interesting consequences that were not fully appreciated until the beam power reached about 840 kW. One consequence was sudden failure of the stripper foil system due to convoy electrons stripped from the incoming H beam, which circled around to strike the foil bracket and cause bracket failure. Another consequence is that convoy electrons can reflect back up from the electron catcher and strike the foil and bracket. An additional contributor to foil system failure is vacuum breakdown due to the charge developed on the foil by secondary electron emission. In this paper we will detail these and other interesting failure mechanisms, and describe the improvements we have made to mitigate them.

  8. Equivalent Diagnostic Classification Models

    ERIC Educational Resources Information Center

    Maris, Gunter; Bechger, Timo

    2009-01-01

    Rupp and Templin (2008) do a good job at describing the ever expanding landscape of Diagnostic Classification Models (DCM). In many ways, their review article clearly points to some of the questions that need to be answered before DCMs can become part of the psychometric practitioners toolkit. Apart from the issues mentioned in this article that…

  9. Sexual Addiction: Diagnostic Problems

    ERIC Educational Resources Information Center

    Giugliano, John R.

    2009-01-01

    In recent years clinicians report a great deal of concern about definition, diagnostic assessment, and treatment modalities when dealing with what might be called out-of-control sexual behavior. Many terms have been used to describe the phenomenon of problematic sexual behavior. Many of these concepts overlap, some are no longer popular, and some…

  10. Rocket Engine Oscillation Diagnostics

    NASA Technical Reports Server (NTRS)

    Nesman, Tom; Turner, James E. (Technical Monitor)

    2002-01-01

    Rocket engine oscillating data can reveal many physical phenomena ranging from unsteady flow and acoustics to rotordynamics and structural dynamics. Because of this, engine diagnostics based on oscillation data should employ both signal analysis and physical modeling. This paper describes an approach to rocket engine oscillation diagnostics, types of problems encountered, and example problems solved. Determination of design guidelines and environments (or loads) from oscillating phenomena is required during initial stages of rocket engine design, while the additional tasks of health monitoring, incipient failure detection, and anomaly diagnostics occur during engine development and operation. Oscillations in rocket engines are typically related to flow driven acoustics, flow excited structures, or rotational forces. Additional sources of oscillatory energy are combustion and cavitation. Included in the example problems is a sampling of signal analysis tools employed in diagnostics. The rocket engine hardware includes combustion devices, valves, turbopumps, and ducts. Simple models of an oscillating fluid system or structure can be constructed to estimate pertinent dynamic parameters governing the unsteady behavior of engine systems or components. In the example problems it is shown that simple physical modeling when combined with signal analysis can be successfully employed to diagnose complex rocket engine oscillatory phenomena.

  11. Tele diagnostic by web

    NASA Astrophysics Data System (ADS)

    Sugiyama, Shigeki

    2006-03-01

    Because of the development of multimedia technologies like Web and Internet, it now becomes possible to think about Tele Medicine and Tele Diagnostic for a distant place where no doctors and no nurses are situated at or are available. And also some kind of intelligence can be added onto them, which makes possible to give certain kind of medical treatment assistance or suggestions for a patient from a computer diagnostic base through the Internetworking. For doing this, here considers about a basic system of "Tele Diagnostic for a remote place" where it dose not have a doctor and a medical assistance. In order to implement the system, JAVA, VRML, HTML, and CORTONA are used as a basic language and a viewer. And also in order to add a kind of intelligence, Augmented Knowledge In Agent (AKIA) by using Back Propagation Neural Networks (BPNN) is used. And by this study, here can introduce the system that has the following basic mechanisms; By inputting physical data like temperature or blood pressure, the system would show a diagnostic assistance by TEXT. And also the bad place of body would be shown graphically if there were any. The system can be put onto Web, so that anybody could have this assistance at any place ubiquitously only if a person has Internetworking access.

  12. ESPC Integrated Skill Diagnostics

    DTIC Science & Technology

    2015-09-30

    monitoring systems for gauging performance of the ESPC. This is an integral part of the overall ESPC goal of developing a global coupled system between...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. ESPC Integrated Skill Diagnostics Maria Flatau Naval...quantitative skill metrics to assess the advancements in the Earth System Prediction Capability (ESPC). This work will also implement automated

  13. Diagnostic peritoneal lavage - slideshow

    MedlinePlus

    ... Indication URL of this page: //medlineplus.gov/ency/presentations/100159.htm Diagnostic peritoneal lavage - series—Indication To use the sharing features on this page, please enable JavaScript. Go to slide 1 out of 4 Go to slide 2 ...

  14. Diagnostics for induction accelerators

    SciTech Connect

    Fessenden, T.J.

    1996-04-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960`s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore`s Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail.

  15. Diagnosing Diagnostic Language Assessment

    ERIC Educational Resources Information Center

    Lee, Yong-Won

    2015-01-01

    Diagnostic language assessment (DLA) is gaining a lot of attention from language teachers, testers, and applied linguists. With a recent surge of interest in DLA, there seems to be an urgent need to assess where the field of DLA stands at the moment and develop a general sense of where it should be moving in the future. The current article, as the…

  16. Beam Diagnostics for FACET

    SciTech Connect

    Li, S.Z.; Hogan, M.J.; /SLAC

    2011-08-19

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to about 20 {micro}m long and focussed to about 10 {micro}m wide. Characterization of the beam-plasma interaction requires complete knowledge of the incoming beam parameters on a pulse-to-pulse basis. FACET diagnostics include Beam Position Monitors, Toroidal current monitors, X-ray and Cerenkov based energy spectrometers, optical transition radiation (OTR) profile monitors and coherent transition radiation (CTR) bunch length measurement systems. The compliment of beam diagnostics and their expected performance are reviewed. Beam diagnostic measurements not only provide valuable insights to the running and tuning of the accelerator but also are crucial for the PWFA experiments in particular. Beam diagnostic devices are being set up at FACET and will be ready for beam commissioning in summer 2011.

  17. MSFC Skylab operations support summary

    NASA Technical Reports Server (NTRS)

    Martin, J. R.

    1974-01-01

    A summary of the actions and problems involved in preparing the Skylab-one vehicle is presented. The subjects discussed are: (1) flight operations support functions and organization, (2) launch operations and booster flight support functions and organization, (3) Skylab launch vehicle support teams, (4) Skylab orbital operations support performance analysis, (5) support manning and procedures, and (6) data support and facilities.

  18. The Second National Conference Summary.

    ERIC Educational Resources Information Center

    Chai, Carolyn

    In this summary of the 1978 National Conference on Asians in America and Asian Americans, conference proceedings, as well as papers and panel discussions, are briefly outlined. Workshops on foreign policy, immigration, Asian identity, education and employment, Indo-Chinese in the United States, teaching English to immigrants, racism and…

  19. User Guide for State Summaries

    EPA Pesticide Factsheets

    The EPA developed state-level summaries of chemical and water use using the project database developed from FracFocus 1.0 disclosures with some limited background information on oil and gas production, geology, and regulations for the state.

  20. Separations innovative concepts: Project summary

    SciTech Connect

    Lee, V.E.

    1988-05-01

    This project summary includes the results of 10 innovations that were funded under the US Department's Innovative Concept Programs. The concepts address innovations that can substantially reduce the energy used in industrial separations. Each paper describes the proposed concept, and discusses the concept's potential energy savings, market applications, technical feasibility, prior work and state of the art, and future development needs.

  1. Subsystems component definitions summary program

    NASA Technical Reports Server (NTRS)

    Scott, A. Don; Thomas, Carolyn C.; Simonsen, Lisa C.; Hall, John B., Jr.

    1991-01-01

    A computer program, the Subsystems Component Definitions Summary (SUBCOMDEF), was developed to provide a quick and efficient means of summarizing large quantities of subsystems component data in terms of weight, volume, resupply, and power. The program was validated using Space Station Freedom Program Definition Requirements Document data for the internal and external thermal control subsystem. Once all component descriptions, unit weights and volumes, resupply, and power data are input, the user may obtain a summary report of user-specified portions of the subsystem or of the entire subsystem as a whole. Any combination or all of the parameters of wet and dry weight, wet and dry volume, resupply weight and volume, and power may be displayed. The user may vary the resupply period according to individual mission requirements, as well as the number of hours per day power consuming components operate. Uses of this program are not limited only to subsystem component summaries. Any applications that require quick, efficient, and accurate weight, volume, resupply, or power summaries would be well suited to take advantage of SUBCOMDEF's capabilities.

  2. Adult Functional Competency: A Summary.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Div. of Extension.

    The Adult Performance Level (APL) project summary specifies the competencies which are functional to economic and educational success in society and describes devices developed for assessing those competencies. The APL theory of functional competency identifies adult needs in general knowledge areas (consumer economics, occupational knowledge,…

  3. Institutional Effectiveness Summary Report, 2001.

    ERIC Educational Resources Information Center

    Burless, Bridget

    This document discusses institutional effectiveness at Florence-Darlington Technical College (FDTC) (South Carolina) for the 2000-2001 academic year. Full and/or interim report summaries are provided for advising procedures, library resources, and for the following departments: Accounting, Automated Office, Office Systems Technology, Health Care…

  4. Biomass energy systems program summary

    SciTech Connect

    1980-07-01

    Research programs in biomass which were funded by the US DOE during fiscal year 1978 are listed in this program summary. The conversion technologies and their applications have been grouped into program elements according to the time frame in which they are expected to enter the commercial market. (DMC)

  5. Project English Summaries, March 1970.

    ERIC Educational Resources Information Center

    Haughey, Charles F.; And Others

    Information concerning Project English, which is being carried out at 14 universities and 1 State Department of Education through the support of the Office of Education, is provided in summary format. Project English is concerned with the development of English curriculum for Grades K through 12 and with the development of curriculum for…

  6. Moriond Electroweak 2006: Theory summary

    SciTech Connect

    Lykken, Joseph D.; /Fermilab

    2006-07-01

    A concise look at the big picture of particle physics, including the status of the Standard Model, neutrinos, supersymmetry, extra dimensions and cosmology. Based upon the theoretical summary presented at the XLIst Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, 11-18 March 2006.

  7. Band alignment at the Cu2SnS3/In2S3 interface measured by X-ray photoemission spectroscopy

    NASA Astrophysics Data System (ADS)

    Jia, Hongjie; Cheng, Shuying; Zhang, Hong; Yu, Jinling; Lai, Yunfeng

    2015-10-01

    This paper focused on investigating the band alignment at the Cu2SnS3 (CTS)/In2S3 heterojunction interface by X-ray photoemission spectroscopy. An In2S3 over-layer was grown on a CTS thin film, which was grown by sulfurization of vacuum thermal evaporated Sn-Cu metallic precursors in a H2S:N2 atmosphere. The valence band offset (VBO) at the CTS/In2S3 interface was measured to be 1.27 ± 0.10 eV. The conduction band offset (CBO) was calculated from the measured VBO, giving (0.58 ± 0.10) eV. These values show that the CBO has a spike-like behavior and the interface is a 'type I'.

  8. The Use of Integrated Electronic Data Capture and Analysis for Accelerator Construction and Commissioning: Pansophy from the SNS Towards the ILC

    SciTech Connect

    J. P. Ozelis; V. Bookwalter; B. Madre; C. E. Reece

    2005-05-01

    Jefferson Lab has extensively used a proprietary web-based system (Pansophy) that integrates commercial database, data analysis, document archiving and retrieval, and user interface software, as a coherent knowledge management product during the construction of the cryomodules for the SNS Superconducting Linac, providing elements of process and procedure control, data capture and review, and data mining and analysis. With near real-time and potentially global access to production data, process monitoring and performance analyses could be pursued in a timely manner, providing crucial feedback. The extensibility, portability, and accessibility of Pansophy via universally available software components provide the essential features needed in any information and project management system capable of meeting the needs of future accelerator construction efforts, requiring an unprecedented level of regional and international coordination and collaboration, to which Pansophy is well suited.

  9. [Optimisation of diagnostics and differential diagnostics disseminated pulmonary tuberculosis].

    PubMed

    Demikhova, O V; Karpina, N L; Lepekha, L N; Bagirov, M A; Amansakhedov, R B

    2012-01-01

    One of the reasons of dramatic situation with tuberculosis in Russia is untimely diagnostics of tuberculosis. The aim of the study was to identify the causes of diagnostic mistakes when we deal with disseminated pulmonary tuberculosis at current stage and to modernize the diagnostic process. The analysis of the diagnostic activity of the consultative diagnostic center of Central Tuberculosis Research Institute of Russian Academy Medical Sciences for 2011 was performed with special attention on the results of the survey of 505 patients with pulmonary dissemination. The frequency of discrepancies of disseminated pulmonary tuberculosis diagnostics was 96.1%. Based on the studies carried out the main causes diagnostic mistakes in patients with disseminated pulmonary tuberculosis were determined. New directions of improving of tuberculosis diagnostics were developed: overall high-technology examination of patient, adherence to the diagnostic procedure, developed by consultative diagnostic center of Central Tuberculosis Research Institute (CTRI), timely performing fiber-optic bronchoscopy with complex biopsy and diagnostic surgery procedures, further training of primary health care doctors. Implementation of proposed activities will significantly (by 3-5 times) reduce the time for diagnostics of respiratory system disease.

  10. Optimization of low cost, non toxic, earth abundant p-type Cu2SnS3 thin film for Photovoltaic application

    NASA Astrophysics Data System (ADS)

    Chaudhari, J. J.; Patel, S.; Joshi, U. S.

    2016-09-01

    Cu2SnS3 (CTS) is one of promising candidate as an absorber material for thin film solar cell. Because of relatively higher prize of Indium and hazardous environmental impact of processing of Gallium, CTS is suitable alternative candidate to Cu2SnS3 (CIGS) based solar cell as its constituent elements such as copper, tin and sulphur are abundantly available in earth's crust. CTS is ternary semiconductor and its energy band gap is 1.5eV, which is perfectly matched with solar energy spectrum for maximum transfer of solar energy into electrical energy through photovoltaic action. The primary methods for the synthesis of CTS are Thermal evaporation, electrochemical, sputtering and wet chemical methods. Here in this paper we have optimized a low cost non-vacuum solution process method for the synthesis of CTS without any external sulfurization. The X-ray diffraction studies showed the formation of phase with the peaks corresponding to (112), (220) and (312) planes. Chemical Solution Deposition (CSD) for the synthesis of CTS is suitable for large area deposition and it includes several routes like solvothermal methods, direct liquid coating and nano ink based technique. The metal Chloride salts and thiourea is used as a source of sulphur to synthesize CTS solution and homogeneous thin films of CTS deposited on glass substrate using spin coating method. Use of abrasive solvent like hydrazine and hydrogen sulphide gas which are used to synthesize CTS thin film have detrimental effect on environment, we report eco friendly solvent based approach to synthesize CTS at low temperature 200 °C.

  11. 3D-QSAR and molecular docking studies on derivatives of MK-0457, GSK1070916 and SNS-314 as inhibitors against Aurora B kinase.

    PubMed

    Zhang, Baidong; Li, Yan; Zhang, Huixiao; Ai, Chunzhi

    2010-11-02

    Development of anticancer drugs targeting Aurora B, an important member of the serine/threonine kinases family, has been extensively focused on in recent years. In this work, by applying an integrated computational method, including comparative molecular field analysis (CoMFA), comparative molecular similarity indices analysis (CoMSIA), homology modeling and molecular docking, we investigated the structural determinants of Aurora B inhibitors based on three different series of derivatives of 108 molecules. The resultant optimum 3D-QSAR models exhibited (q(2) = 0.605, r(2) (pred) = 0.826), (q(2) = 0.52, r(2) (pred) = 0.798) and (q(2) = 0.582, r(2) (pred) = 0.971) for MK-0457, GSK1070916 and SNS-314 classes, respectively, and the 3D contour maps generated from these models were analyzed individually. The contour map analysis for the MK-0457 model revealed the relative importance of steric and electrostatic effects for Aurora B inhibition, whereas, the electronegative groups with hydrogen bond donating capacity showed a great impact on the inhibitory activity for the derivatives of GSK1070916. Additionally, the predictive model of the SNS-314 class revealed the great importance of hydrophobic favorable contour, since hydrophobic favorable substituents added to this region bind to a deep and narrow hydrophobic pocket composed of residues that are hydrophobic in nature and thus enhanced the inhibitory activity. Moreover, based on the docking study, a further comparison of the binding modes was accomplished to identify a set of critical residues that play a key role in stabilizing the drug-target interactions. Overall, the high level of consistency between the 3D contour maps and the topographical features of binding sites led to our identification of several key structural requirements for more potency inhibitors. Taken together, the results will serve as a basis for future drug development of inhibitors against Aurora B kinase for various tumors.

  12. DIAGNOSTICS OF BNL ERL

    SciTech Connect

    POZDEYEV,E.; BEN-ZVI, I.; CAMERON, P.; GASSNER, D.; KAYRAN, D.; ET AL.

    2007-06-25

    The ERL Prototype project is currently under development at the Brookhaven National Laboratory. The ERL is expected to demonstrate energy recovery of high-intensity beams with a current of up to a few hundred milliamps, while preserving the emittance of bunches with a charge of a few nanocoulombs produced by a high-current SRF gun. To successfully accomplish this task the machine will include beam diagnostics that will be used for accurate characterization of the three dimensional beam phase space at the injection and recirculation energies, transverse and longitudinal beam matching, orbit alignment, beam current measurement, and machine protection. This paper outlines requirements on the ERL diagnostics and describes its setup and modes of operation.

  13. ICF diagnostics. Revision 1

    SciTech Connect

    Coleman, L.W.

    1982-12-17

    In the past several years there have been significant advances and accomplishments in the field of Inertial Confinement Fusion (ICF) research which are directly attributable to an active experimental program supported by the development and applications of sophisticated and specialized diagnostics instruments and techniques. The continued development of high temporal-and spatial-resolution diagnostics, although with a somewhat different technical emphasis than previously, is essential for maintaining progress in ICF. With the generation of inertial fusion drivers now becoming available progress toward higher density compression of fusion fuel will be attained at the expense of temperature, and consequently emissions from the targets will be limited. At the same time since the targets are being driven to higher density they are more opaque to the low-to-moderate energy x-rays (up to a few keV) and particles (alpha particles, protons, and knock-on charged particles) that have been utilized for diagnosing target performance.

  14. Viral Hemorrhagic Fever Diagnostics

    PubMed Central

    Racsa, Lori D.; Kraft, Colleen S.; Olinger, Gene G.; Hensley, Lisa E.

    2016-01-01

    There are 4 families of viruses that cause viral hemorrhagic fever (VHF), including Filoviridae. Ebola virus is one virus within the family Filoviridae and the cause of the current outbreak of VHF in West Africa. VHF-endemic areas are found throughout the world, yet traditional diagnosis of VHF has been performed in large reference laboratories centered in Europe and the United States. The large amount of capital needed, as well as highly trained and skilled personnel, has limited the availability of diagnostics in endemic areas except in conjunction with governmental and nongovernmental entities. However, rapid diagnosis of VHF is essential to efforts that will limit outbreaks. In addition, increased global travel suggests VHF diagnoses may be made outside of the endemic areas. Thus, understanding how to diagnose VHF is imperative for laboratories worldwide. This article reviews traditional and current diagnostic modalities for VHF. PMID:26354968

  15. Cardiovascular modeling and diagnostics

    SciTech Connect

    Kangas, L.J.; Keller, P.E.; Hashem, S.; Kouzes, R.T.

    1995-12-31

    In this paper, a novel approach to modeling and diagnosing the cardiovascular system is introduced. A model exhibits a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. Potentially, a model will be incorporated into a cardiovascular diagnostic system. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the variables of an individual at a given time are used for diagnosis. This approach also exploits sensor fusion to optimize the utilization of biomedical sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  16. Advances in diagnostic radiology.

    PubMed

    Runge, Val M

    2010-12-01

    Recent advances in diagnostic radiology are discussed on the basis of current publications in Investigative Radiology. Publications in the journal during 2009 and 2010 are reviewed, evaluating developments by modality and anatomic region. Technological advances continue to play a major role in the evolution and clinical practice of diagnostic radiology, and as such constitute a major publication focus. In the past 2 years, this includes advances in both magnetic resonance and computed tomography (in particular, the advent of dual energy computed tomography). An additional major focus of publications concerns contrast media, and in particular continuing research involving nephrogenic systemic fibrosis, its etiology, and differentiation of the gadolinium chelates on the basis of in vivo stability.

  17. Endodontic diagnostic terminology update.

    PubMed

    McClannahan, Scott B; Baisden, Michael K; Bowles, Walter R

    2011-01-01

    Determination of the etiology of the patient's chief complaint and a correct diagnosis are paramount prior to a recommendation of endodontic therapy. Reproduction of the patient's chief complaint is critical. If the chief complaint cannot be reproduced, consider consultation with or referral to an endodontist or orofacial pain specialist. The diagnostic terminology presented in this update provides for a more accurate description and communication of the health or pathological conditions of both pulpal and apical tissues. This information is summarized in Table I.

  18. PROcess Based Diagnostics PROBE

    NASA Technical Reports Server (NTRS)

    Clune, T.; Schmidt, G.; Kuo, K.; Bauer, M.; Oloso, H.

    2013-01-01

    Many of the aspects of the climate system that are of the greatest interest (e.g., the sensitivity of the system to external forcings) are emergent properties that arise via the complex interplay between disparate processes. This is also true for climate models most diagnostics are not a function of an isolated portion of source code, but rather are affected by multiple components and procedures. Thus any model-observation mismatch is hard to attribute to any specific piece of code or imperfection in a specific model assumption. An alternative approach is to identify diagnostics that are more closely tied to specific processes -- implying that if a mismatch is found, it should be much easier to identify and address specific algorithmic choices that will improve the simulation. However, this approach requires looking at model output and observational data in a more sophisticated way than the more traditional production of monthly or annual mean quantities. The data must instead be filtered in time and space for examples of the specific process being targeted.We are developing a data analysis environment called PROcess-Based Explorer (PROBE) that seeks to enable efficient and systematic computation of process-based diagnostics on very large sets of data. In this environment, investigators can define arbitrarily complex filters and then seamlessly perform computations in parallel on the filtered output from their model. The same analysis can be performed on additional related data sets (e.g., reanalyses) thereby enabling routine comparisons between model and observational data. PROBE also incorporates workflow technology to automatically update computed diagnostics for subsequent executions of a model. In this presentation, we will discuss the design and current status of PROBE as well as share results from some preliminary use cases.

  19. 78 FR 11216 - Enforcement Actions Summary

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... SECURITY Transportation Security Administration Enforcement Actions Summary AGENCY: Transportation Security Administration, DHS. ACTION: Notice of availability. SUMMARY: The Transportation Security Administration (TSA) is..., Transportation Security Administration, 601 South 12th Street, Arlington, VA......

  20. 76 FR 9357 - Enforcement Actions Summary

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... SECURITY Transportation Security Administration Enforcement Actions Summary AGENCY: Transportation Security Administration, DHS. ACTION: Notice of Availability. SUMMARY: The Transportation Security Administration (TSA) is..., TSA-2, Transportation Security Administration, 601 South 12th Street,......

  1. Summary Report of Journal Operations, 2006

    ERIC Educational Resources Information Center

    American Psychologist, 2007

    2007-01-01

    This article provides a summary report of American Psychological Association journal operations, 2006. This summary is compiled from the 2006 annual reports of the Council of Editors and from Central Office records.

  2. Microsphere based saliva diagnostics

    NASA Astrophysics Data System (ADS)

    Rissin, David M.; DiCesare, Christopher; Hayman, Ryan B.; Blicharz, Timothy M.; Walt, David R.

    2005-11-01

    Saliva presents a minimally invasive alternative medium to blood for performing diagnostics1. Microsphere sensors for ions, small organic molecules, and proteins are currently being developed and optical microarrays containing thousands of these sensors will be used for simultaneous multi-analyte analysis. The fiber bundle platform in use is 1mm in diameter and contains approximately 50,000 individually addressable 3.1μm fibers, each with an etched well capable of housing a single 3.1μm microsphere sensor. Micron-sized bead-based chemistries are produced in house, followed by deposition onto a fiber-optic bundle platform, allowing for multiplexed analysis. The ultimate goal is to develop a universal diagnostic system using saliva as the diagnostic medium. This platform will permit multiplexed analysis of a sample by integrating microfluidics with the optical arrays loaded with sensors capable of detecting relevant biomarkers associated with a wide range of disease states. Disease states that are currently under investigation include end stage renal disease (ESRD) and Sjoegrens Syndrome (SS).

  3. Microgravity Combustion Diagnostics Workshop

    NASA Technical Reports Server (NTRS)

    Santoro, Gilbert J. (Editor); Greenberg, Paul S. (Editor); Piltch, Nancy D. (Editor)

    1988-01-01

    Through the Microgravity Science and Applications Division (MSAD) of the Office of Space Science and Applications (OSSA) at NASA Headquarters, a program entitled, Advanced Technology Development (ATD) was promulgated with the objective of providing advanced technologies that will enable the development of future microgravity science and applications experimental flight hardware. Among the ATD projects one, Microgravity Combustion Diagnostics (MCD), has the objective of developing advanced diagnostic techniques and technologies to provide nonperturbing measurements of combustion characteristics and parameters that will enhance the scientific integrity and quality of microgravity combustion experiments. As part of the approach to this project, a workshop was held on July 28 and 29, 1987, at the NASA Lewis Research Center. A small group of laser combustion diagnosticians met with a group of microgravity combustion experimenters to discuss the science requirements, the state-of-the-art of laser diagnostic technology, and plan the direction for near-, intermediate-, and long-term programs. This publication describes the proceedings of that workshop.

  4. [Histopathological meniscus diagnostic].

    PubMed

    Fisseler-Eckhoff, A; Müller, K-M

    2009-06-01

    Menisci fulfill many functions within the complex biomechanics of the knee joint. In the case of meniscus lesions, sparing arthroscopic resections and operative refixation are the treatments of choice. With regard to diagnostics, this means that in general terms, the histopathologic diagnostics are carried out on detached meniscus fragments of between 5 mm and 2 cm in size. An experienced pathologist's knowledge of physiologically possible cellular and fibrous histological meniscus damage, as opposed to nonphysiological change regarded as normal with respect to age, is essential during a diagnostic meniscus evaluation. The clinician expects clear statements from the pathologist regarding the severity of previous or secondary degenerative meniscus damage, the age and type of traumatic tears, and appraisal of the relationship between trauma and meniscus damage from an insurance point of view. Close cooperation between the clinician and the pathologist allows for fast and unambiguous correlation of anamnesis, the clinical picture, and morphological reporting so that cases involving insurance problems - which are numerous, often long-term, and often unsatisfactory - can be clarified quickly.

  5. Alpha Particle Diagnostic

    SciTech Connect

    Fisher, Ray, K.

    2009-05-13

    The study of burning plasmas is the next frontier in fusion energy research, and will be a major objective of the U.S. fusion program through U.S. collaboration with our international partners on the ITER Project. For DT magnetic fusion to be useful for energy production, it is essential that the energetic alpha particles produced by the fusion reactions be confined long enough to deposit a significant fraction of their initial ~3.5 MeV energy in the plasma before they are lost. Development of diagnostics to study the behavior of energetic confined alpha particles is a very important if not essential part of burning plasma research. Despite the clear need for these measurements, development of diagnostics to study confined the fast confined alphas to date has proven extremely difficult, and the available techniques remain for the most part unproven and with significant uncertainties. Research under this grant had the goal of developing diagnostics of fast confined alphas, primarily based on measurements of the neutron and ion tails resulting from alpha particle knock-on collisions with the plasma deuterium and tritium fuel ions. One of the strengths of this approach is the ability to measure the alphas in the hot plasma core where the interesting ignition physics will occur.

  6. CF 6 engine diagnostics

    NASA Technical Reports Server (NTRS)

    Stricklin, R.

    1981-01-01

    A summary of the activities which led to defining deterioration rates of the CF6 family of engines, a description of what was learned, and an identification of means of conserving fuel based upon the program findings are presented. The program to define the deterioration levels and modes for the CF6 family of engines involved four distinct phases: analysis of inbound engine test results, analysis of airline cruise data, analysis of airline test cell data resulting from testing of refurbished engines, and inspection of engine hardware.

  7. Research Summaries for Normal Birth

    PubMed Central

    Romano, Amy M.

    2006-01-01

    In this column, the author presents summaries of four current research studies that further support the benefits of normal birth. The topics of the studies address the benefits of the hands-and-knees position in labor, postmenopausal urinary incontinence, the impact on perinatal outcomes of coached versus uncoached pushing during the second stage of labor, and the impact of the duration of breastfeeding on the likelihood of developing type-2 diabetes later in life.

  8. Summary of Technical Operations, 1991

    DTIC Science & Technology

    1992-01-01

    34Can We Rely on Fault Tolerant Sys- tems?," and Dr. Jean - Claude Laprie, a director at CNRS-LAAS, Toulouse, France, 14 1991 Summary of Technical...Redesign ( DAMMS -R). The domain model will be used in both the Operational Movement Program and Highway Operations Team subsystems of DAMMS -R. Project...SEI will use the model as a basis for designing reusable software packages to be used initially for DAMMS -R and subsequently for ATCCS battlefield

  9. Summary

    SciTech Connect

    Powell, Danny H; Elwood Jr, Robert H

    2011-01-01

    An effective risk assessment system is needed to address the threat posed by an active or passive insider who, acting alone or in collusion, could attempt diversion or theft of nuclear material. The material control and accountability (MC&A) system effectiveness tool (MSET) is a self-assessment or inspection tool utilizing probabilistic risk assessment (PRA) methodology to calculate the system effectiveness of a nuclear facility's material protection, control, and accountability (MPC&A) system. The MSET process is divided into four distinct and separate parts: (1) Completion of the questionnaire that assembles information about the operations of every aspect of the MPC&A system; (2) Conversion of questionnaire data into numeric values associated with risk; (3) Analysis of the numeric data utilizing the MPC&A fault tree and the SAPHIRE computer software; and (4) Self-assessment using the MSET reports to perform the effectiveness evaluation of the facility's MPC&A system. The process should lead to confirmation that mitigating features of the system effectively minimize the threat, or it could lead to the conclusion that system improvements or upgrades are necessary to achieve acceptable protection against the threat. If the need for system improvements or upgrades is indicated when the system is analyzed, MSET provides the capability to evaluate potential or actual system improvements or upgrades. A facility's MC&A system can be evaluated at a point in time. The system can be reevaluated after upgrades are implemented or after other system changes occur. The total system or specific subareas within the system can be evaluated. Areas of potential system improvement can be assessed to determine where the most beneficial and cost-effective improvements should be made. Analyses of risk importance factors show that sustainability is essential for optimal performance and reveals where performance degradation has the greatest impact on total system risk. The risk importance factors show the amount of risk reduction achievable with potential upgrades and the amount of risk reduction achieved after upgrades are completed. Applying the risk assessment tool gives support to budget prioritization by showing where budget support levels must be sustained for MC&A functions most important to risk. Results of the risk assessment are also useful in supporting funding justifications for system improvements that significantly reduce system risk. The functional model, the system risk assessment tool, and the facility evaluation questionnaire are valuable educational tools for MPC&A personnel. These educational tools provide a framework for ongoing dialogue between organizations regarding the design, development, implementation, operation, assessment, and sustainability of MPC&A systems. An organization considering the use of MSET as an analytical tool for evaluating the effectiveness of its MPC&A system will benefit from conducting a complete MSET exercise at an existing nuclear facility.

  10. Summary

    SciTech Connect

    Blandford, Roger; /KIPAC, Menlo Park

    2007-10-22

    The first International GLAST Symposium was held at Stanford, with less than a year to launch. Recent advances in the TeV and MeV ranges augur well for GLAST making major discoveries in GeV astronomy. Expectations for observations of several source types and backgrounds are summarized, along with some remaining organizational challenges.

  11. 2012 HIV Diagnostics Conference: the molecular diagnostics perspective.

    PubMed

    Branson, Bernard M; Pandori, Mark

    2013-04-01

    2012 HIV Diagnostic Conference Atlanta, GA, USA, 12-14 December 2012. This report highlights the presentations and discussions from the 2012 National HIV Diagnostic Conference held in Atlanta (GA, USA), on 12-14 December 2012. Reflecting changes in the evolving field of HIV diagnostics, the conference provided a forum for evaluating developments in molecular diagnostics and their role in HIV diagnosis. In 2010, the HIV Diagnostics Conference concluded with the proposal of a new diagnostic algorithm which included nucleic acid testing to resolve discordant screening and supplemental antibody test results. The 2012 meeting, picking up where the 2010 meeting left off, focused on scientific presentations that assessed this new algorithm and the role played by RNA testing and new developments in molecular diagnostics, including detection of total and integrated HIV-1 DNA, detection and quantification of HIV-2 RNA, and rapid formats for detection of HIV-1 RNA.

  12. Summary Street: Interactive Computer Support for Writing

    ERIC Educational Resources Information Center

    Wade-Stein, David; Kintsch, Eileen

    2004-01-01

    Summary Street is educational software based on latent semantic analysis (LSA), a computer method for representing the content of texts. The classroom trial described here demonstrates the power of LSA to support an educational goal by providing automatic feedback on the content of students' summaries. Summary Street provides this feedback in an…

  13. 7 CFR 3402.12 - Project summary.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Project summary. 3402.12 Section 3402.12 Agriculture Regulations of the Department of Agriculture (Continued) NATIONAL INSTITUTE OF FOOD AND AGRICULTURE FOOD AND... Application § 3402.12 Project summary. Using the Project Summary, Form NIFA-2003, applicants must...

  14. 7 CFR 3402.12 - Project summary.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Project summary. 3402.12 Section 3402.12 Agriculture Regulations of the Department of Agriculture (Continued) NATIONAL INSTITUTE OF FOOD AND AGRICULTURE FOOD AND... Application § 3402.12 Project summary. Using the Project Summary, Form NIFA-2003, applicants must...

  15. 31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and... DEVELOPMENT BANDS (MDBs) § 26.3 Availability of Environmental Impact Assessment Summaries (EIA Summaries)...

  16. Planetary Transmission Diagnostics

    NASA Technical Reports Server (NTRS)

    Lewicki, David G. (Technical Monitor); Samuel, Paul D.; Conroy, Joseph K.; Pines, Darryll J.

    2004-01-01

    This report presents a methodology for detecting and diagnosing gear faults in the planetary stage of a helicopter transmission. This diagnostic technique is based on the constrained adaptive lifting algorithm. The lifting scheme, developed by Wim Sweldens of Bell Labs, is a time domain, prediction-error realization of the wavelet transform that allows for greater flexibility in the construction of wavelet bases. Classic lifting analyzes a given signal using wavelets derived from a single fundamental basis function. A number of researchers have proposed techniques for adding adaptivity to the lifting scheme, allowing the transform to choose from a set of fundamental bases the basis that best fits the signal. This characteristic is desirable for gear diagnostics as it allows the technique to tailor itself to a specific transmission by selecting a set of wavelets that best represent vibration signals obtained while the gearbox is operating under healthy-state conditions. However, constraints on certain basis characteristics are necessary to enhance the detection of local wave-form changes caused by certain types of gear damage. The proposed methodology analyzes individual tooth-mesh waveforms from a healthy-state gearbox vibration signal that was generated using the vibration separation (synchronous signal-averaging) algorithm. Each waveform is separated into analysis domains using zeros of its slope and curvature. The bases selected in each analysis domain are chosen to minimize the prediction error, and constrained to have the same-sign local slope and curvature as the original signal. The resulting set of bases is used to analyze future-state vibration signals and the lifting prediction error is inspected. The constraints allow the transform to effectively adapt to global amplitude changes, yielding small prediction errors. However, local wave-form changes associated with certain types of gear damage are poorly adapted, causing a significant change in the

  17. Invasive mycoses: diagnostic challenges.

    PubMed

    Ostrosky-Zeichner, Luis

    2012-01-01

    Despite the availability of newer antifungal drugs, outcomes for patients with invasive fungal infections (IFIs) continue to be poor, in large part due to delayed diagnosis and initiation of appropriate antifungal therapy. Standard histopathologic diagnostic techniques are often untenable in at-risk patients, and culture-based diagnostics typically are too insensitive or nonspecific, or provide results after too long a delay for optimal IFI management. Newer surrogate markers of IFIs with improved sensitivity and specificity are needed to enable earlier diagnosis and, ideally, to provide prognostic information and/or permit therapeutic monitoring. Surrogate assays should also be accessible and easy to implement in the hospital. Several nonculture-based assays of newer surrogates are making their way into the medical setting or are currently under investigation. These new or up-and-coming surrogates include antigens/antibodies (mannan and antimannan antibodies) or fungal metabolites (d-arabinitol) for detection of invasive candidiasis, the Aspergillus cell wall component galactomannan used to detect invasive aspergillosis, or the fungal cell wall component and panfungal marker β-glucan. In addition, progress continues with use of polymerase chain reaction- or other nucleic acid- or molecular-based assays for diagnosis of either specific or generic IFIs, although the various methods must be better standardized before any of these approaches can be more fully implemented into the medical setting. Investigators are also beginning to explore the possibility of combining newer surrogate markers with each other or with more standard diagnostic approaches to improve sensitivity, specificity, and capacity for earlier diagnosis, at a time when fungal burden is still relatively low and more responsive to antifungal therapy.

  18. Diagnostic and vaccine chapter.

    PubMed

    Wolfram, J H; Kokanov, S K; Verkhovsky, O A

    2010-10-01

    The first report in this chapter describes the development of a killed composite vaccine. This killed vaccine is non-infectious to humans, other animals, and the environment. The vaccine has low reactivity, is non-abortive, and does not induce pathomorphological alterations to the organs of vaccinated animals. The second report of this chapter describes the diagnostic value of a competitive enzyme-linked immunosorbent assay for detecting Brucella-specific antibodies and its ability to discriminate vaccinated cattle from infected cattle. The results indicated that the competitive enzyme-linked immunosorbent assay is more sensitive than traditional tests for detecting antibodies to Brucella abortus in naturally and experimentally infected cattle.

  19. Diagnostics for hybrid reactors

    NASA Astrophysics Data System (ADS)

    Orsitto, Francesco Paolo

    2012-06-01

    The Hybrid Reactor(HR) can be considered an attractive actinide-burner or a fusion assisted transmutation for destruction of transuranic(TRU) nuclear waste. The hybrid reactor has two important subsystems: the tokamak neutron source and the blanket which includes a fuel zone where the TRU are placed and a tritium breeding zone. The diagnostic system for a HR must be as simple and robust as possible to monitor and control the plasma scenario, guarantee the protection of the machine and monitor the transmutation.

  20. [Molecular diagnostics in neuropathology].

    PubMed

    Dietmaier, W; Lorenz, J; Riemenschneider, M J

    2015-03-01

    As in only few other areas of oncology, molecular markers in neurooncology have become an integral part of clinical decision-making. This development is driven by a bustling scientific activity exploring the molecular basis and pathogenesis of human brain tumors. In addition, a high percentage of brain tumor patients are included in clinical studies in which molecular markers are assessed and linked with clinical informativeness. First steps towards more differentiated therapeutic strategies against brain tumors have thus been taken. The implementation in the clinical and diagnostic routine requires a detailed knowledge and a close collaboration between all medical disciplines involved.