Sample records for circulation cooldown tests

  1. Experimental study on natural circulation precooling of cryogenic pump system with gas phase inlet reflux configuration

    NASA Astrophysics Data System (ADS)

    Chen, G. B.; Zhong, Y. K.; Zheng, X. L.; Li, Q. F.; Xie, X. M.; Gan, Z. H.; Huang, Y. H.; Tang, K.; Kong, B.; Qiu, L. M.

    2003-12-01

    A novel gas-phase inlet configuration in the natural circulation system instead of the liquid-phase inlet is introduced to cool down a cryogenic pump system from room temperature to cryogenic temperatures, effectively. The experimental apparatus is illustrated and test process is described. Heat transfer and pressure drop data during the cool-down process are recorded and portrayed. By contrast with liquid-phase inlet configuration, experimental results demonstrate that the natural circulation with the gas-phase inlet configuration is an easier and more controllable way to cool down the pump system and maintain it at cryogenic temperatures.

  2. 40 CFR 86.1335-90 - Cool-down procedure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cold cycle exhaust emission test may begin after a cool-down only when the engine oil and water... Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test Procedures § 86.1335-90 Cool-down procedure. (a) This cool-down procedure applies to Otto-cycle and diesel engines...

  3. 40 CFR 86.1335-90 - Cool-down procedure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cold cycle exhaust emission test may begin after a cool-down only when the engine oil and water... Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test Procedures § 86.1335-90 Cool-down procedure. (a) This cool-down procedure applies to Otto-cycle and diesel engines...

  4. 40 CFR 86.1335-90 - Cool-down procedure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... cold cycle exhaust emission test may begin after a cool-down only when the engine oil and water... Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test Procedures § 86.1335-90 Cool-down procedure. (a) This cool-down procedure applies to Otto-cycle and diesel engines...

  5. Operational experience with the supercritical helium during the TF coils tests campaign of SST-1

    NASA Astrophysics Data System (ADS)

    Panchal, Rohitkumar Natvarlal; Patel, Rakesh; Tank, Jignesh; Mahesuria, Gaurang; Sonara, Dashrath; Tanna, Vipul; Patel, Jayant; Srikanth, G. L. N.; Singh, Manoj; Patel, Ketan; Christian, Dikens; Garg, Atul; Bairagi, Nitn; Gupta, Manoj Kumar; Nimavat, Hiren; Shah, Pankil; Sharma, Rajiv; Pradhan, Subrata

    2012-06-01

    Under the 'SST-1 mission mandate' recently, all the sixteen Steady State Superconducting Tokamak (SST-1) Toroidal Field (TF) magnets have been successfully tested at their nominal currents of 10000 A in cold under supercritical helium (SHe) flow conditions. The TF magnets test campaign have begun in an experimental cryostat since June 2010 with the SST-1 Helium cryogenics facility, which is a 1.3 kW at 4.5 K helium refrigerator-cum-liquefier (HRL) system. The HRL provides ~300 g-s-1supercritical helium (SHe) with cold circulator (CC) as well as ~ 60 g-s-1 without cold circulator to fulfill the forced flow cooling requirements of SST- 1 magnets. In case of single TF coil tests, we can adjust HRL process parameters such that an adequate amount of required supercritical helium is available without the cold circulator. In this paper, the complete process is describing the Process Flow Diagram (PFD) of 1.3 kW at 4.5 K HRL, techniques to generate supercritical helium without using the cold-circulator and the results of the cooldown, steady state characteristics and experience of supercritical helium operations during the TF coils test campaign have been discussed.

  6. Cryogenic expansion joint for large superconducting magnet structures

    DOEpatents

    Brown, Robert L.

    1978-01-01

    An expansion joint is provided that accommodates dimensional changes occurring during the cooldown and warm-up of large cryogenic devices such as superconducting magnet coils. Flattened tubes containing a refrigerant such as gaseous nitrogen (N.sub.2) are inserted into expansion spaces in the structure. The gaseous N.sub.2 is circulated under pressure and aids in the cooldown process while providing its primary function of accommodating differential thermal contraction and expansion in the structure. After lower temperatures are reached and the greater part of the contraction has occured, the N.sub.2 liquefies then solidifies to provide a completely rigid structure at the cryogenic operating temperatures of the device.

  7. Thermo-hydraulic analysis of the cool-down of the EDIPO test facility

    NASA Astrophysics Data System (ADS)

    Lewandowska, Monika; Bagnasco, Maurizio

    2011-09-01

    The first cool-down of the EDIPO (European DIPOle) test facility is foreseen to take place in 2011 by means of the existing 1.2 kW cryoplant at EPFL-CRPP Villigen. In this work, the thermo-hydraulic analysis of the EDIPO cool-down is performed in order both to assess the its duration and to optimize the procedure. The cool-down is driven by the helium flowing in both the outer cooling channel and in the windings connected hydraulically in parallel. We take into account limitations due to the pressure drop in the cooling circuit and the refrigerator capacity as well as heat conduction in the iron yoke. Two schemes of the hydraulic cooling circuit in the EDIPO windings are studied (coils connected in series and coils connected in parallel). The analysis is performed by means of an analytical model complemented by and numerical model. The results indicate that the cool-down to 5 K can be achieved in about 12 days.

  8. 40 CFR 86.1335-90 - Cool-down procedure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...'s internal or external surfaces except for water and air as prescribed in paragraphs (c) and (d) of this section. (c) For water-cooled engines, two types of cooling are permitted: (1) Water may be circulated through the engine's water coolant system. (i) The coolant may be flowed in either direction and...

  9. Thermal Considerations for Reducing the Cooldown and Warmup Duration of the James Webb Space Telescope OTIS Cryo-Vacuum Test

    NASA Technical Reports Server (NTRS)

    Yang, Kan; Glazer, Stuart; Ousley, Wes; Burt, William

    2017-01-01

    The James Webb Space Telescope (JWST), set to launch in 2018, is NASAs next-generation flagship telescope. The Optical Telescope Element (OTE) and Integrated Science Instrument Module (ISIM) contain all of the optical surfaces and instruments to capture and analyze the telescopes infrared targets. The integrated OTE and ISIM are denoted as OTIS, and will be tested as a single unit in a critical thermal-vacuum test in mid-2017 at NASA Johnson Space Centers Chamber A facility. The payload will be evaluated for workmanship and functionality in a 20K simulated flight environment during this thermal-vacuum test. However, the sheer thermal mass of the OTIS payload as well as the restrictive gradient, rate, and contamination-related constraints placed on test components precludes rapid cooldown or warmup to its steady-state cryo-balance condition. Hardware safety considerations precludes injection of helium gas for free molecular heat transfer. Initial thermal analysis predicted that transient radiative cooldown from ambient temperatures, while meeting all limits and constraints, would take 33.3 days; warmup similarly would take 28.4 days. This paper discusses methods used to reduce transition times from the original predictions through modulation of boundary temperatures and environmental conditions. By optimizing helium shroud transition rates and heater usage, as well as rigorously re-examining previously imposed constraints, savings of up to three days on cooldown and up to a week on warmup can be achieved. The efficiencies gained through these methods allow the JWST thermal test team to create faster cooldown and warmup profiles, thus reducing the overall test duration and cost, while keeping all of the required test operations.

  10. Flight Test Results for the NICMOS Cryocooler

    NASA Technical Reports Server (NTRS)

    Dolan, F. X.; McCormick, J. A.; Nellis, G. F.; Sixsmith, H.; Swift, W. L.

    1999-01-01

    In October 1998 a mechanical cryocooler and cryogenic circulator loop were flown on NASA's STS-95 as part of the Hubble Orbital System Test (HOST). The system will be installed on the Hubble Space Telescope (HST) during Service Mission #3 in 2000 and will provide cooling to the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). It will extend the useful life of that instrument by 5 to 10 years. This was the first successful space demonstration of a turbobrayton cryocooler. The cooler is a single stage reverse Brayton type, using low-vibration high-speed miniature turbomachines for the compression and expansion functions. A miniature centrifugal cryogenic circulator is used to deliver refrigerated neon to the instrument. During the mission, the cooler operated without anomalies for approximately 185 hours over a range of conditions to verify its mechanical, thermodynamic and control functions. The cryocooler satisfied all mission objectives including maximum cooldown to near-design operating conditions, warm and cold starts and stops, operation at near-design temperatures, and demonstration of long-term temperature stability. This paper presents a description of the cooler and its operation during the HOST flight.

  11. Shuttle Centaur engine cooldown evaluation and effects of expanded inlets on start transient

    NASA Technical Reports Server (NTRS)

    1987-01-01

    As part of the integration of the RL10 engine into the Shuttle Centaur vehicle, a satisfactory method of conditioning the engine to operating temperatures had to be established. This procedure, known as cooldown, is different from the existing Atlas Centaur due to vehicle configuration and mission profile differenced. The program is described, and the results of a Shuttle Centaur cooldown program are reported. Mission peculiarities cause substantial variation in propellant inlet conditions between the substantiated Atlas Centaur and Shuttle Centaur with the Shuttle Centaur having much larger variation in conditions. A test program was conducted to demonstrate operation of the RL10 engine over the expanded inlet conditions. As a result of this program, the Shuttle Centaur requirements were proven satisfactory. Minor configuration changes incorporated as a result of this program provide substantial reduction in cooldown propellant consumption.

  12. Fast cooldown coaxial pulse tube microcooler

    NASA Astrophysics Data System (ADS)

    Nast, T.; Olson, J. R.; Champagne, P.; Roth, E.; Kaldas, G.; Saito, E.; Loung, V.; McCay, B. S.; Kenton, A. C.; Dobbins, C. L.

    2016-05-01

    We report the development and initial testing of the Lockheed Martin first-article, single-stage, compact, coaxial, Fast Cooldown Pulse Tube Microcryocooler (FC-PTM). The new cryocooler supports cooling requirements for emerging large, high operating temperature (105-150K) infrared focal plane array sensors with nominal cooling loads of ~300 mW @105K @293K ambient. This is a sequel development that builds on our inline and coaxial pulse tube microcryocoolers reported at CEC 20137, ICC188,9, and CEC201510. The new FC-PTM and the prior units all share our long life space technology attributes, which typically have 10 year life requirements1. The new prototype microcryocooler builds on the previous development by incorporating cold head design improvements in two key areas: 1) reduced cool-down time and 2) novel repackaging that greatly reduces envelope. The new coldhead and Dewar were significantly redesigned from the earlier versions in order to achieve a cooldown time of 2-3 minutes-- a projected requirement for tactical applications. A design approach was devised to reduce the cold head length from 115mm to 55mm, while at the same time reducing cooldown time. We present new FC-PTM performance test measurements with comparisons to our previous pulse-tube microcryocooler measurements and design predictions. The FC-PTM exhibits attractive small size, volume, weight, power and cost (SWaP-C) features with sufficient cooling capacity over required ambient conditions that apply to an increasing variety of space and tactical applications.

  13. Fast cool-down coaxial pulse tube microcooler

    NASA Astrophysics Data System (ADS)

    Nast, T.; Olson, J. R.; Champagne, P.; Roth, E.; Kaldas, G.; Saito, E.; Loung, V.; McCay, B. S.; Kenton, A. C.; Dobbins, C. L.

    2016-09-01

    We report the development and initial testing of the Lockheed Martin first-article, single-stage, compact, coaxial, Fast Cooldown Pulse Tube Microcryocooler (FC-PTM). The new cryocooler supports cooling requirements for emerging large, high operating temperature (105-150K) infrared focal plane array sensors with nominal cooling loads of 300 mW @105K @293K ambient. This is a sequel development that builds on our inline and coaxial pulse tube microcryocoolers reported at CEC 20137, ICC188,9, and CEC201510. The new FC-PTM and the prior units all share our long life space technology attributes, which typically have 10 year life requirements1. The new prototype microcryocooler builds on the previous development by incorporating cold head design improvements in two key areas: 1) reduced cool-down time and 2) novel repackaging that greatly reduces envelope. The new coldhead and Dewar were significantly redesigned from the earlier versions in order to achieve a cooldown time of 2-3 minutes- a projected requirement for tactical applications. A design approach was devised to reduce the cold head length from 115mm to 55mm, while at the same time reducing cooldown time. We present new FC-PTM performance test measurements with comparisons to our previous pulse-tube microcryocooler measurements and design predictions. The FC-PTM exhibits attractive small size, volume, weight, power and cost (SWaP-C) features with sufficient cooling capacity over required ambient conditions that apply to an increasing variety of space and tactical applications.

  14. Cool-down and frozen start-up behavior of a grooved water heat pipe

    NASA Technical Reports Server (NTRS)

    Jang, Jong Hoon

    1990-01-01

    A grooved water heat pipe was tested to study its characteristics during the cool-down and start-up periods. The water heat pipe was cooled down from the ambient temperature to below the freezing temperature of water. During the cool-down, isothermal conditions were maintained at the evaporator and adiabatic sections until the working fluid was frozen. When water was frozen along the entire heat pipe, the heat pipe was rendered inactive. The start-up of the heat pipe from this state was studied under several different operating conditions. The results show the existence of large temperature gradients between the evaporator and the condenser, and the moving of the melting front of the working fluid along the heat pipe. Successful start-up was achieved for some test cases using partial gravity assist. The start-up behavior depended largely on the operating conditions.

  15. Effect of cooldown and residual magnetic field on the performance of niobium–copper clad superconducting radio-frequency cavity

    DOE PAGES

    Dhakal, Pashupati; Ciovati, Gianluigi

    2017-11-22

    Here, we present the results of rf measurements on a niobium–copper clad superconducting radio-frequency cavity with different cooldown conditions and residual magnetic field in a vertical test Dewar in order to explore the effect of thermal current induced magnetic field and its trapping on the performance of the cavity. The residual resistance, extracted from the Q 0( T) curves in the temperature range 4.3–1.5 K, showed no dependence on a temperature gradient along the cavity during the cooldown across the critical temperature up to ~50 K m –1. The rf losses due to the trapping of residual magnetic field duringmore » the cavity cooldown were found to be ~4.3 nΩ μT –1, comparable to the values measured in bulk niobium cavities. An increase of residual resistance following multiple cavity quenches was observed along with evidence of trapping of magnetic flux generated by thermoelectric currents.« less

  16. Effect of cooldown and residual magnetic field on the performance of niobium–copper clad superconducting radio-frequency cavity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dhakal, Pashupati; Ciovati, Gianluigi

    Here, we present the results of rf measurements on a niobium–copper clad superconducting radio-frequency cavity with different cooldown conditions and residual magnetic field in a vertical test Dewar in order to explore the effect of thermal current induced magnetic field and its trapping on the performance of the cavity. The residual resistance, extracted from the Q 0( T) curves in the temperature range 4.3–1.5 K, showed no dependence on a temperature gradient along the cavity during the cooldown across the critical temperature up to ~50 K m –1. The rf losses due to the trapping of residual magnetic field duringmore » the cavity cooldown were found to be ~4.3 nΩ μT –1, comparable to the values measured in bulk niobium cavities. An increase of residual resistance following multiple cavity quenches was observed along with evidence of trapping of magnetic flux generated by thermoelectric currents.« less

  17. Design and testing a high fuel volume fraction, externally finned, thermionic emitter.

    NASA Technical Reports Server (NTRS)

    Peelgren, M. L.; Ernst, D. M.

    1971-01-01

    A prototypical, high fuel volume fraction, thermionic emitter body was designed and tested. The emitter body is all tungsten, with a 1.40-cm ID, a 3.23-cm OD, and eight full-length axial fins. The emitter thickness is 0.15 cm while the fins and outer clad are 0.075 cm thick. Different methods of fabrication were used in making the test samples. Stress analysis was performed with a three-dimensional elastic code. Thermal testing of the samples, duplicating calculated radial temperature gradients, heatup and cooldown rates, and emitter body temperatures in operation, was performed with no structural failures noted (six heatup and cooldown cycles per sample). Further emitter analysis and testing is planned.

  18. 49 CFR 193.2505 - Cooldown.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... keeps thermal stresses within design limits during the cooldown period, paying particular attention to the performance of expansion and contraction devices. (b) After cooldown stabilization is reached...

  19. Note: Sub-Kelvin refrigeration with dry-coolers on a rotating system.

    PubMed

    Oguri, S; Ishitsuka, H; Choi, J; Kawai, M; Tajima, O

    2014-08-01

    We developed a cryogenic system on a rotating table that achieves sub-Kelvin conditions. The cryogenic system consists of a helium sorption cooler and a pulse tube cooler in a cryostat mounted on a rotating table. Two rotary-joint connectors for electricity and helium gas circulation enable the coolers to be operated and maintained with ease. We performed cool-down tests under a condition of continuous rotation at 20 rpm. We obtained a temperature of 0.23 K with a holding time of more than 24 h, thus complying with catalog specifications. We monitored the system's performance for four weeks; two weeks with and without rotation. A few-percent difference in conditions was observed between these two states. Most applications can tolerate such a slight difference. The technology developed is useful for various scientific applications requiring sub-Kelvin conditions on rotating platforms.

  20. The Impact of Vocal Cool-down Exercises: A Subjective Study of Singers' and Listeners' Perceptions.

    PubMed

    Ragan, Kari

    2016-11-01

    Using subjective measures, this study investigated singers' and listeners' perceptions of changes in voice condition after vocal cool-down exercises. A single-subject crossover was designed to evaluate whether there were discernible differences in either singer or listener perceptions from pre (no vocal cool downs) to post (with cool downs) test. Subjective questionnaires were completed throughout the study. Twenty classically trained female singers documented self-ratings and perceptual judgments through the Evaluation of the Ability to Sing Easily survey, the Singing Voice Handicap Index, and Self-Perceptual Questionnaires after a 60-minute voice load. Recordings were made and assessed by four expert listeners. The assessed data from the Singing Voice Handicap Index, the Evaluation of the Ability to Sing Easily, and Daily Perceptual Questionnaires show 68%, 67%, and 74% of singers reported improvement, respectively. However, because of significant variability in the underlying scores, the amount of improvement was not deemed to be statistically significant. Expert listeners correctly identified the cool-down week 46% of the time. Singers strongly perceived positive impact from the cool-down exercises on both their speaking and singing voices. Even though the objective data were statistically insignificant, the singers' subjective data clearly indicates a perceived sense of vocal well-being after utilizing the vocal cool-down protocol. The variability in the daily life of a singer (eg, stress, menses, reflux, vocal load, and vocal hygiene) makes it difficult to objectively quantify the impact of vocal cool downs. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  1. Operational experience from LCLS-II cryomodule testing

    NASA Astrophysics Data System (ADS)

    Wang, R.; Hansen, B.; White, M.; Hurd, J.; Atassi, O. Al; Bossert, R.; Pei, L.; Klebaner, A.; Makara, J.; Theilacker, J.; Kaluzny, J.; Wu, G.; Harms, E.

    2017-12-01

    This paper describes the initial operational experience gained from testing Linac Coherent Light Source II (LCLS-II) cryomodules at Fermilab’s Cryomodule Test Facility (CMTF). Strategies for a controlled slow cooldown to 100 K and a fast cooldown past the niobium superconducting transition temperature of 9.2 K will be described. The test stand for the cryomodules at CMTF is sloped to match gradient in the LCLS-II tunnel at Stanford Linear Accelerator (SLAC) laboratory, which adds an additional challenge to stable liquid level control. Control valve regulation, Superconducting Radio-Frequency (SRF) power compensation, and other methods of stabilizing liquid level and pressure in the cryomodule 2.0 K SRF cavity circuit will be discussed. Several different pumping configurations using cold compressors and warm vacuum pumps have been used on the cryomodule 2.0 K return line and the associated results will be described.

  2. Measurements of the Acoustic Speaking Voice After Vocal Warm-up and Cooldown in Choir Singers.

    PubMed

    Onofre, Fernanda; Prado, Yuka de Almeida; Rojas, Gleidy Vannesa E; Garcia, Denny Marco; Aguiar-Ricz, Lílian

    2017-01-01

    The aim of this study was to evaluate the acoustic measurements of the vowel /a/ in modal recording before and after a singing voice resistance test and after 30 minutes of absolute rest in female choir singers. This is a prospective cohort study. A total of 13 soprano choir singers with experience in choir singing were evaluated through analysis of acoustic voice parameters at three points in time: before continuous use of the voice, after vocal warm-up and a singing test 60 minutes in duration respecting the pauses for breathing, and after vocal cooldown and an absolute voice rest for 30 minutes. The fundamental frequency increased after the voice resistance test (P = 0.012) and remained elevated after the 30 minutes of voice rest (P = 0.01). The jitter decreased after the voice resistance test (P = 0.02) and after the 30 minutes of voice rest. A significant difference was detected for the acoustic voice parameters relative average perturbation (RAP), (P = 0.05), and pitch perturbation quotient (PPQ), (P = 0.04), compared with the initial time point. The fundamental frequency increased after 60 minutes of singing and remained elevated after vocal cooldown and absolute rest for 30 minutes, proving an efficient parameter for identifying the changes inherent to voice demand during singing. Copyright © 2017. Published by Elsevier Inc.

  3. Sample Holder for Cryogenic Adhesive Shear Test

    NASA Technical Reports Server (NTRS)

    Ledbetter, F. E.; Clemons, J. M.; White, W. T.; Penn, B.; Semmel, M. L.

    1983-01-01

    Five samples tested in one cooldown. Holder mounted in testing machine. Submerged in cryogenic liquid held in cryostat. Movable crosshead of testing machine moves gradually downward. Samples placed under tension, one after another, starting with top one; each sample fails in turn before next is stressed.

  4. Modeling and Experiments on Fast Cooldown of a 120 Hz Pulse Tube Cryocooler

    NASA Astrophysics Data System (ADS)

    Vanapalli, Srinivas; Lewis, Michael; Grossman, Gershon; Gan, Zhihua; Radebaugh, Ray; Brake, H. J. M. ter

    2008-03-01

    High frequency operation of a pulse tube cryocooler leads to reduced regenerator volume, which results in a reduced heat capacity and a faster cooldown time. A pulse tube cryocooler operating at a frequency of 120 Hz and an average pressure of 3.5 MPa achieved a no-load temperature of 50 K. The cooling power at 80 K was about 3.35 W with a cooldown time from 285 K to 80 K of about 5.5 minutes, even though the additional thermal mass at the cold end due to flanges, screws, heater, and thermometer was 4.2 times that of the regenerator. This fast cooldown is about two to four times faster than that of typical pulse tube cryocoolers and is very attractive to many applications. In this study we measure the cooldown time to 80 K for different cold-end masses and extrapolate to zero cold-end mass. We also present an analytical model for the cooldown time for different cold-end masses and compare the results with the experiments. The model and the extrapolated experimental results indicate that with zero cold-end mass the cooldown time to 80 K with this 120 Hz pulse tube cryocooler would be about 32 s.

  5. Operational Experience from LCLS-II Cryomodule Testing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Renzhuo; Hansen, Benjamin; White, Michael

    This paper describes the initial operational experience gained from testing Linac Coherent Light Source II (LCLS-II) cryomodules at Fermilab’s Cryomodule Test Facility (CMTF). Strategies for a controlled slow cooldown to 100 K and a fast cooldown past the niobium superconducting transition temperature of 9.2 K will be described. The test stand for the cryomodules at CMTF is sloped to match gradient in the LCLS-II tunnel at Stanford Linear Accelerator (SLAC) laboratory, which adds an additional challenge to stable liquid level control. Control valve regulation, Superconducting Radio-Frequency (SRF) power compensation, and other methods of stabilizing liquid level and pressure in themore » cryomodule 2.0 K SRF cavity circuit will be discussed. Several different pumping configurations using cold compressors and warm vacuum pumps have been used on the cryomodule 2.0 K return line and the associated results will be described.« less

  6. Study of the Cooldown and Warmup for the Eight Sectors of the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Liu, L.; Riddone, G.; Tavian, L.

    2004-06-01

    The LHC cryogenic system is based on a five-point feed scheme with eight refrigerators serving the eight sectors of the LHC machine. The paper presents the simplified flow scheme of the eight sectors and the mathematical methods including the program flowchart and the boundary conditions to simulate the cooldown and warmup of these sectors. The methods take into account the effect of the pressure drop across the valves as well as the pressure evolution in the different headers of the cryogenic distribution line. The simulated pressure and temperature profiles of headers of the LHC sector during the cooldown and warmup are given and the temperature evolutions of entire processes of cooldown and warmup are presented. As a conclusion, the functions of the input temperature for the normal and fast cooldown and warmup, the cooldown and warmup time of each sector and the distributions of mass flow rates in each sector are summarized. The results indicate that it is possible to cool down any of the LHC sector within 12.7 days in normal operation and 6.8 days in case of fast operation.

  7. Multipurpose electric furnace system. [for use in Apollo-Soyuz Test Program

    NASA Technical Reports Server (NTRS)

    Mazelsky, R.; Duncan, C. S.; Seidensticker, R. G.; Johnson, R. A.; Mchugh, J. P.; Foust, H. C.; Piotrowski, P. A.

    1974-01-01

    A multipurpose electric furnace system of advanced design for space applications was developed and tested. This system is intended for use in the Apollo-Soyuz Test Program. It consists of the furnace, control package and a helium package for rapid cooldown.

  8. Detailed studies of aviation fuel flowability

    NASA Technical Reports Server (NTRS)

    Mehta, H. K.; Armstrong, R. S.

    1985-01-01

    Six Jet A fuels, with varying compositions, were tested for low temperature flowability in a 190-liter simulator tank that modeled a section of a wing tank of a wide-body commercial airplane. The insulated tank was chilled by circulating coolant through the upper and lower surfaces. Flow-ability was determined as a function of fuel temperature by holdup, the fraction of unflowable fuel remaining in the tank after otherwise complete withdrawal. In static tests with subfreezing tank conditions, hold up varied with temperature and fuel composition. However, a general correlation of two or three classes of fuel type was obtained by plotting holdup as a function of the difference between freezing point and boundary-layer temperature, measured 0.6 cm above the bottom tank surface. Dynamic conditions of vibrations and slosh or rate of fuel withdrawal had very minor effects on holdup. Tests with cooling schedules to represent extreme, cold-day flights showed, at most, slight holdup for any combination of fuel type or dynamic conditions. Tests that superimposed external fuel heating and recirculation during the cooldown period indicates reduced hold up by modification of the low-temperature boundary layer. Fuel heating was just as effective when initiated during the later times of the tests as when applied continuously.

  9. 46 CFR 154.1831 - Persons in charge of transferring liquid cargo in bulk or preparing cargo tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in bulk or a cool-down, warm-up, gas-free, or air-out of each cargo tank; (2) Each transfer of liquid cargo in bulk, and each cool-down, warm-up, gas-free, or air-out of a cargo tank, is supervised by a... in bulk or a cool-down, warm-up, gas-free, or air-out of a cargo tank possesses the qualifications...

  10. 46 CFR 154.1831 - Persons in charge of transferring liquid cargo in bulk or preparing cargo tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... in bulk or a cool-down, warm-up, gas-free, or air-out of each cargo tank; (2) Each transfer of liquid cargo in bulk, and each cool-down, warm-up, gas-free, or air-out of a cargo tank, is supervised by a... in bulk or a cool-down, warm-up, gas-free, or air-out of a cargo tank possesses the qualifications...

  11. 46 CFR 154.1831 - Persons in charge of transferring liquid cargo in bulk or preparing cargo tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in bulk or a cool-down, warm-up, gas-free, or air-out of each cargo tank; (2) Each transfer of liquid cargo in bulk, and each cool-down, warm-up, gas-free, or air-out of a cargo tank, is supervised by a... in bulk or a cool-down, warm-up, gas-free, or air-out of a cargo tank possesses the qualifications...

  12. 46 CFR 154.1831 - Persons in charge of transferring liquid cargo in bulk or preparing cargo tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... in bulk or a cool-down, warm-up, gas-free, or air-out of each cargo tank; (2) Each transfer of liquid cargo in bulk, and each cool-down, warm-up, gas-free, or air-out of a cargo tank, is supervised by a... in bulk or a cool-down, warm-up, gas-free, or air-out of a cargo tank possesses the qualifications...

  13. PIE on Safety-Tested AGR-1 Compact 5-1-1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hunn, John D.; Morris, Robert Noel; Baldwin, Charles A.

    Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High-Temperature Gas-cooled Reactors (HTGRs). AGR-1 was the first in a series of TRISO fuel irradiation experiments initiated in 2006 under the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program; this work continues to be funded by the Department of Energy's Office of Nuclear Energy as part of the Advanced Reactor Technologies (ART) initiative. AGR-1 fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 and irradiated for three years in the Idaho National Laboratory (INL) Advanced Test Reactormore » (ATR) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. PIE is being performed at INL and ORNL to study how the fuel behaved during irradiation, and to examine fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing of irradiated AGR-1 Compact 5-1-1 in the ORNL Core Conduction Cooldown Test Facility (CCCTF) and post-safety testing PIE.« less

  14. 78 FR 7681 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Furnaces and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    .... Description of AFUE Inflation Issues Associated with Omitting Cool-Down and Heat-Up Testing for Two-Stage and... to revise a provision concerning the insulation of the flue collector box in order to ensure the... furnaces and boilers that employ the optional procedure to skip [[Page 7683

  15. 10 CFR Appendix N to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the damper remains open during the cool-down test. For furnaces that employ post purge, measure the... control—cool-down test. For a furnace with adjustable fan control, this time delay will be 3.0 minutes for... 10 Energy 3 2014-01-01 2014-01-01 false Uniform Test Method for Measuring the Energy Consumption...

  16. 10 CFR Appendix N to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the damper remains open during the cool-down test. For furnaces that employ post purge, measure the... control—cool-down test. For a furnace with adjustable fan control, this time delay will be 3.0 minutes for... 10 Energy 3 2011-01-01 2011-01-01 false Uniform Test Method for Measuring the Energy Consumption...

  17. 10 CFR Appendix N to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the damper remains open during the cool-down test. For furnaces that employ post purge, measure the... control—cool-down test. For a furnace with adjustable fan control, this time delay will be 3.0 minutes for... 10 Energy 3 2012-01-01 2012-01-01 false Uniform Test Method for Measuring the Energy Consumption...

  18. 10 CFR Appendix N to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Furnaces and Boilers

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the damper remains open during the cool-down test. For furnaces that employ post purge, measure the... control—cool-down test. For a furnace with adjustable fan control, this time delay will be 3.0 minutes for... 10 Energy 3 2013-01-01 2013-01-01 false Uniform Test Method for Measuring the Energy Consumption...

  19. 49 CFR 193.2505 - Cooldown.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Cooldown. 193.2505 Section 193.2505 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES...

  20. Magnetic Flux Expulsion Studies in Niobium SRF Cavities

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Posen, Sam; Checchin, Mattia; Crawford, Anthony

    2016-06-01

    With the recent discovery of nitrogen doping treatment for SRF cavities, ultra-high quality factors at medium accelerating fields are regularly achieved in vertical RF tests. To preserve these quality factors into the cryomodule, it is important to consider background magnetic fields, which can become trapped in the surface of the cavity during cooldown and cause Q₀ degradation. Building on the recent discovery that spatial thermal gradients during cooldown can significantly improve expulsion of magnetic flux, a detailed study was performed of flux expulsion on two cavities with different furnace treatments that are cooled in magnetic fields amplitudes representative of whatmore » is expected in a realistic cryomodule. In this contribution, we summarize these cavity results, in order to improve understanding of the impact of flux expulsion on cavity performance.« less

  1. Molecular Tagging Velocimetry Development for In-situ Measurement in High-Temperature Test Facility

    NASA Technical Reports Server (NTRS)

    Andre, Matthieu A.; Bardet, Philippe M.; Burns, Ross A.; Danehy, Paul M.

    2015-01-01

    The High Temperature Test Facility, HTTF, at Oregon State University (OSU) is an integral-effect test facility designed to model the behavior of a Very High Temperature Gas Reactor (VHTR) during a Depressurized Conduction Cooldown (DCC) event. It also has the ability to conduct limited investigations into the progression of a Pressurized Conduction Cooldown (PCC) event in addition to phenomena occurring during normal operations. Both of these phenomena will be studied with in-situ velocity field measurements. Experimental measurements of velocity are critical to provide proper boundary conditions to validate CFD codes, as well as developing correlations for system level codes, such as RELAP5 (http://www4vip.inl.gov/relap5/). Such data will be the first acquired in the HTTF and will introduce a diagnostic with numerous other applications to the field of nuclear thermal hydraulics. A laser-based optical diagnostic under development at The George Washington University (GWU) is presented; the technique is demonstrated with velocity data obtained in ambient temperature air, and adaptation to high-pressure, high-temperature flow is discussed.

  2. Treatments To Produce Stabilized Aluminum Mirrors for Cryogenic Uses

    NASA Technical Reports Server (NTRS)

    Zewari, Wahid; Barthelmy, Michael; Ohl, Raymond

    2005-01-01

    Five metallurgical treatments have been tested as means of stabilizing mirrors that are made of aluminum alloy 6061 and are intended for use in cryogenic applications. Aluminum alloy 6061 is favored as a mirror material by many scientists and engineers. Like other alloys, it shrinks upon cool-down from room temperature to cryogenic temperature. This shrinkage degrades the optical quality of the mirror surfaces. Hence, the metallurgical treatments were tested to determine which one could be most effective in minimizing the adverse optical effects of cooldown to cryogenic temperatures. Each of the five metallurgical treatments comprises a multistep process, the steps of which are interspersed with the steps of the mirror-fabrication process. The five metallurgical-treatment/fabrication.- process combinations were compared with each other and with a benchmark fabrication process, in which a mirror is made from an alloy blank by (1) symmetrical rough machining, (2) finish machining to within 0.006 in. (. 0.15 mm) of final dimensions, and finally (3) diamond turning to a mirror finish.

  3. Improving the Testing Environment of a Lab Transition-Edge Sensor: An Exercise in Nulling Earth’s Magnetic Field

    NASA Astrophysics Data System (ADS)

    Melton, Casey; McCammon Lab at University of Wisconsin-Madison

    2018-01-01

    In Dr. Dan McCammon’s lab at the University of Wisconsin-Madison, a special class of x-ray microcalorimeter called a Transition-Edge Sensor, or TES, is being tested in order to identify the strengths and weaknesses of this device in detecting x-ray photons from astronomical sources. The TES is currently housed in a cryogenic refrigerator where it can be tested at superconducting temperatures. Although this refrigerator is equipped with magnetic field shielding to keep magnetic fields out during testing, latent magnetic fields are trapped inside the receptacle at the time of cool-down. To remedy this problem, I built a set of tri-axial Helmholtz coils, which have at their center a uniform volume of magnetic field. This uniform region can be tuned prior to cool-down and nulls the magnetic field that would typically be trapped inside the receptacle. The magnetic field will be monitored inside the receptacle with a tri-axial fluxgate magnetic field sensor, which I began designing in the latter half of the project. This project is still in progress, and will be implemented in the lab in the near future.

  4. Design features and operational characteristics of the Langley pilot transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1974-01-01

    A fan-driven transonic cryogenic tunnel was designed, and its purging, cooldown, and warmup times were determined satisfactory. Cooling with liquid nitrogen is at the power levels required for transonic testing. Good temperature distributions are obtained by using a simple nitrogen injection system.

  5. Hanford spent nuclear fuel hot conditioning system test procedure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cleveland, K.J.

    1997-09-16

    This document provides the test procedures for cold testing of the prototype Hot Conditioning System (HCS) at the 306E Facility. The primary objective of this testing is to confirm design choices and provide data for the detailed design package prior to procurement of the process equipment. The current scope of testing in this document includes a fabricability study of the HCS, equipment performance testing of the HCS components, heat-up and cool-down cycle simulation, and robotic arm testing.

  6. A study of LC-39 cryogenic systems. Part 1: A study of the vacuum insulated transfer lines at Kennedy Space Center. Part 2: Cooldown pressure surges

    NASA Technical Reports Server (NTRS)

    Ludtke, P. R.; Voth, R. O.

    1971-01-01

    The vacuum liquid hydrogen and liquid oxygen transfer lines at Kennedy Space Center were studied to evaluate the feasibility of using a condensing gas such as CO2 inside the vacuum spaces to achieve a condensing-vacuum. The study indicates that at ambient temperature, a maximum vacuum hyphen space pressure of 4000 microns is acceptable for the LH2 transfer lines. In addition, the cooldown procedures for the 14-inch cross-country liquid oxygen line was studied using a simplified mathematical model. Preliminary cooldown times are presented for various heat leak rates to the line and for two vent configurations.

  7. Study of cryogenic propellant systems for loading the space shuttle

    NASA Technical Reports Server (NTRS)

    Voth, R. O.; Steward, W. G.; Hall, W. J.

    1974-01-01

    Computer programs were written to model the liquid oxygen loading system for the space shuttle. The programs allow selection of input data through graphic displays which schematically depict the part of the system being modeled. The computed output is also displayed in the form of graphs and printed messages. Any one of six computation options may be selected. The first four of these pertain to thermal stresses, pressure surges, cooldown times, flow rates and pressures during cooldown. Options five and six deal with possible water hammer effects due to closing of valves, steady flow and transient response to changes in operating conditions after cooldown. Procedures are given for operation of the graphic display unit and minicomputer.

  8. Influence of collector heat capacity and internal conditions of heat exchanger on cool-down process of small gas liquefier

    NASA Astrophysics Data System (ADS)

    Saberimoghaddam, Ali; Bahri Rasht Abadi, Mohammad Mahdi

    2018-01-01

    Joule-Thomson cooling systems are commonly used in gas liquefaction. In small gas liquefiers, transient cool-down time is high. Selecting suitable conditions for cooling down process leads to decrease in time and cost. In the present work, transient thermal behavior of Joule-Thomson cooling system including counter current helically coiled tube in tube heat exchanger, expansion valve, and collector was studied using experimental tests and simulations. The experiments were performed using small gas liquefier and nitrogen gas as working fluid. The heat exchanger was thermally studied by experimental data obtained from a small gas liquefier. In addition, the simulations were performed using experimental data as variable boundary conditions. A comparison was done between presented and conventional methods. The effect of collector heat capacity and convection heat transfer coefficient inside the tubes on system performance was studied using temperature profiles along the heat exchanger.

  9. RSRM nozzle fixed housing cooldown test

    NASA Technical Reports Server (NTRS)

    Bolieau, D. J.

    1989-01-01

    Flight 5 aft segments with nozzles were exposed to -17 F temperatures while awaiting shipment to KSC in February, 1989. No records were found which show that any previous nozzles were exposed to air temperatures as low as those seen by the Flight 5 nozzles. Thermal analysis shows that the temperature of the fixed housing, and forward and aft exit cone components dropped as low as -10 F. Structural analysis of the nozzles at these low temperatures show the forward and aft exit cone adhesive bonds to have a positive margin of safety, based on a 2.0 safety factor. These analyses show the normal and shear stresses in the fixed housing bond as low values. However, the hoop and meridinal stresses were predicted to be in the 4000 psi range; the failure stress allowable of EA913NA adhesive at -7 F. If the bonds did break in directions perpendicular to the surfaces, called bond crazing, no normal bond strength would be lost. Testing was conducted in two phases, showing that no degradation to the adhesive bonds occurred while the Flight 5 nozzles were subjected to subzero temperatures. The results of these tests are documented. Phase 1 testing cooled a full-scale RSRM insulated fixed housing to -13 F, with extensive bondline inspections. Phase 2 testing cooled the witness panel adhesive tensile buttions to -13 F, with failure strengths recorded before, during, and after the cooldown.

  10. Cluster randomised control trial for cricket injury prevention programme (CIPP): a protocol paper.

    PubMed

    Soomro, Najeebullah; Chua, Nina; Freeston, Jonathan; Ferdinands, Rene E D; Sanders, Ross

    2017-09-28

    Injury prevention programmes (IPPs) are effective in reducing injuries among adolescent team sports. However, there is no validated cricket-specific IPP despite the high incidence of musculoskeletal injuries among amateur cricketers. To evaluate whether a cricket injury prevention programme (CIPP) as a pretraining warm-up or post-training cool-down can reduce injury rates in amateur cricket players. CIPP is a cluster randomised controlled trial which includes 36 male amateur club teams having cricket players aged 14-40 years to be randomly assigned to three study arms: warm-up, cool-down and control (n=12 teams, 136 players in each arm). The intervention groups will perform 15 min CIPP either as a pretraining warm-up or a post-training cool-down. The primary outcome measure will be injury incidence per 1000 player hours and the secondary outcome measures will be whether IPP as a warm-up is better than IPP as a cool-down, and the adherence to the intervention. ACTRN 1261700047039. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Integration, commissioning, and performance of the UK FMOS spectrograph

    NASA Astrophysics Data System (ADS)

    Dalton, Gavin B.; Lewis, Ian J.; Tosh, Ian A. J.; Blackburn, Colin; Bonfield, David G.; Brooks, Charles B.; Holmes, Alan R.; Lee, Hanshin; Froud, Tim R.; Akiyama, Masayuki; Tamura, Naoyuki; Takato, Naruhisa

    2008-07-01

    The UK FMOS spectrograph forms part of Subaru's FMOS multi-object infrared spectroscopy facility. The spectrograph was shipped to Hilo in component form in August of 2007. We describe the integration sequence for the spectrograph, the results of cooldown tests using a new chiller unit fitted to the spectrograph at the telescope, and alignment tests of the spectrograph, gratings and OH-suppression masks. We present the first-light observations for the spectrograph from May 2008.

  12. Influence of mobile air-conditioning on vehicle emissions and fuel consumption: a model approach for modern gasoline cars used in Europe.

    PubMed

    Weilenmann, Martin F; Vasic, Ana-Marija; Stettler, Peter; Novak, Philippe

    2005-12-15

    The influence of air-conditioning activity on the emissions and fuel consumption of passenger cars is an important issue, since fleet penetration and use of these systems have reached a high level. Apart from the MOBILE6 study in the United States, little data is available on the impact of air-conditioning devices (A/Cs). Since weather conditions and A/C technologies both differ from those in the U. S., a test series was designed for the European setting. A fleet of six modern gasoline passenger cars was tested in different weather conditions. Separate test series were carried out for the initial cooldown and for the stationary situation of keeping the interior of the vehicle cool. As assumed, CO2 emissions and fuel consumption rise with the thermal load. This also causes a notable rise in CO and hydrocarbons (HCs). Moreover, A/Cs do not stop automatically at low ambient temperatures; if necessary, they produce dry air to demist the windscreen. A model is proposed that shows a constant load for lower temperatures and a linear trend for higher temperatures. The initial cooldown tests highlight significant differences among cars but show that A/C operation for the initial cooling of an overheated passenger compartment does not result in any extra emissions for the fleet as a whole.

  13. 40 CFR 63.323 - Test methods and monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air-perchloroethylene gas-vapor stream on the outlet side of the refrigerated condenser on a dry-to-dry machine, dryer, or reclaimer with a temperature sensor to determine if it is equal to or less than 7.2 °C (45 °F) before the end of the cool-down or drying cycle while the gas-vapor stream is flowing...

  14. 40 CFR 63.323 - Test methods and monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air-perchloroethylene gas-vapor stream on the outlet side of the refrigerated condenser on a dry-to-dry machine, dryer, or reclaimer with a temperature sensor to determine if it is equal to or less than 7.2 °C (45 °F) before the end of the cool-down or drying cycle while the gas-vapor stream is flowing...

  15. Analysis of dewar and transfer line cooldown in Superfluid Helium On-Orbit Transfer Flight Experiment (SHOOT)

    NASA Technical Reports Server (NTRS)

    Ng, Y. S.; Lee, J. H.

    1989-01-01

    The Superfluid Helium On-Orbit Transfer Flight Experiment (SHOOT) is designed to demonstrate the techniques and components required for orbital superfluid (He II) replenishment of observatories and satellites. One of the tasks planned in the experiment is to cool a warm cryogen tank and a warm transfer line to liquid helium temperature. A math model, based on single-phase vapor flow heat transfer, has been developed to predict the cooldown time, component temperature histories, and helium consumption rate, for various initial conditions of the components and for the thermomechanical pump heater powers of 2 W and 0.5 W. This paper discusses the model and the analytical results, which can be used for planning the experiment operations and determining the pump heater power required for the cooldown operation.

  16. Optimization of the cooling profile to achieve crack-free Yb:S-FAP crystals

    NASA Astrophysics Data System (ADS)

    Fang, H. S.; Qiu, S. R.; Zheng, L. L.; Schaffers, K. I.; Tassano, J. B.; Caird, J. A.; Zhang, H.

    2008-08-01

    Yb:S-FAP [Yb 3+:Sr 5(PO 4) 3F] crystals are an important gain medium for diode-pumped laser applications. Growth of 7.0 cm diameter Yb:S-FAP crystals utilizing the Czochralski (CZ) method from SrF 2-rich melts often encounters cracks during the post-growth cool-down stage. To suppress cracking during cool-down, a numerical simulation of the growth system was used to understand the correlation between the furnace power during cool-down and the radial temperature differences within the crystal. The critical radial temperature difference, above which the crystal cracks, has been determined by benchmarking the simulation results against experimental observations. Based on this comparison, an optimal three-stage ramp-down profile was implemented, which produced high-quality, crack-free Yb:S-FAP crystals.

  17. Leak testing and repair of fusion devices

    NASA Astrophysics Data System (ADS)

    Kozman, T. A.

    1983-06-01

    The leak testing, reporting and vacuum leak repair techniques of the MPTF yin-yang number one magnet system, the world's largest superconducting magnet system, are discussed. Based on this experience, techniques are developed for testing and repairing leaks on the 42 MPTF-B magnets. The leak hunting techniques for the yin-yang magnet systems were applied to two helium circuits (the coil bundle and guard vacuum; both require helium flow for magnet cooldown). Additionally, during MPTF-B operation there are warm water plasma shields and piping that require leak checking.

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eddy, N.; Fellenz, B.; Prieto, P.

    The first cryomodule for the beam test facility at the Fermilab New-Muon-Lab building is currently under RF commissioning. Among other diagnostics systems, the transverse position of the helium gas return pipe with the connected 1.3 GHz SRF accelerating cavities is measured along the {approx}15 m long module using a stretched-wire position monitoring system. An overview of the wire position monitor system technology is given, along with preliminary results taken at the initial module cooldown, and during further testing. As the measurement system offers a high resolution, we also discuss options for use as a vibration detector. An electron beam testmore » facility, based on superconducting RF (SRF) TESLA-style cryomodules is currently under construction at the Fermilab New-Muon-Lab (NML) building. The first, so-called type III+, cryomodule (CM-1), equipped with eight 1.3 GHz nine-cell accelerating cavities was recently cooled down to 2 K, and is currently under RF conditioning. The transverse alignment of the cavity string within the cryomodule is crucial for minimizing transverse kick and beam break-up effects, generated by the high-order dipole modes of misaligned accelerating structures. An optimum alignment can only be guaranteed during the assembly of the cavity string, i.e. at room temperatures. The final position of the cavities after cooldown is uncontrollable, and therefore unknown. A wire position monitoring system (WPM) can help to understand the transverse motion of the cavities during cooldown, their final location and the long term position stability after cryo-temperatures are settled, as well as the position reproducibility for several cold-warm cycles. It also may serve as vibration sensor, as the wire acts as a high-Q resonant detector for mechanical vibrations in the low-audio frequency range. The WPM system consists out of a stretched-wire position detection system, provided with help of INFN-Milano and DESY Hamburg, and RF generation and read-out electronics, developed at Fermilab.« less

  19. Non-Intrusive Velocity Measurements with MTV During DCC Event in the HTTF

    NASA Technical Reports Server (NTRS)

    Andre, M. A.; Bardet, P. M.; Cadell, S. R.; Woods, B.; Burns, R. A.; Danehy, P. M.

    2017-01-01

    Velocity profiles are measured using molecular tagging velocimetry (MTV) in the high temperature test facility (HTTF) at Oregon State University during a depressurized conduction cooldown (DCC) event. The HTTF is a quarter scale electrically heated nuclear reactor simulator designed to replicate various accident scenarios. During a DCC, a double ended guillotine break results in the reactor pressure vessel (RPV) depressurizing into the reactor cavity and ultimately leading to air ingress in the reactor core (lock-exchange and gas diffusion). It is critical to understand the resulting buoyancy-driven flow to characterize the reactor self-cooling capacity through natural circulation. During tests conducted at ambient pressure and temperature, the RPV containing helium is opened (via the hot and cold legs) to a large vessel filled with nitrogen to simulate the atmosphere. The velocity profile on the hot leg pipe centerline is recorded at 10 Hz with MTV based on NO tracers. The precision of the velocimetry was measured to be 0.02 m/s in quiescent flow prior to the tests. A helium flow from the RPV is initially observed in the top quarter of the pipe. During the first 20 seconds of the event, helium flows out of the RPV with a maximum velocity below 2 m/s. The velocity profile transitions from parabolic to linear in character and decays slowly over the rest of the recording; peak velocities of 0.2 m/s are observed after 30 min. A counter-flow of nitrogen is also observed intermittently, which occurs at lower velocities (>0.1 m/s).

  20. The Effect of the Wall Contact and Post-Growth C001-Down on Defects in CdTe Crystals Grown by Contactless PVT

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Grasza, K.; Dudley, M.; Raghothamachar, B.; Cai, L.; Durose, K.; Halliday, D.; Boyall, N. M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    In crystal growth, the quality of the final material may depend, among other factors, on its interaction with the walls of the ampoule during and after the growth, and on the rate of the crystal cool-down at the end of ate the process. To investigate the above phenomena, a series of CdTe crystal growth processes was carried out, The crystals were grown by physical vapor transport without contact with the side walls of the silica glass ampoules, applying the Low Supersaturation Nucleation technique. The source temperature was 930 C, the undercooling was a few degrees. The crystals, having the diameter of 25 mm, grew at the rate of a few mm per day. The post-growth cool-down to the room temperature was conducted at different rates, and lasted from a few minutes to four days. The crystals were characterized using chemical etching low temperature luminescence, and Synchrotron White Beam X-ray Topography techniques. The dislocation (etch pit) density was measured and its distribution was analyzed by comparison with Poisson curves and with the Normalized Radial Distribution Correlation Function. It was found that the contact of the crystal with silica leads to a strain field and high (in the 105 sq cm range) dislocation (etch pit) density. Similar defect concentrations were found in crystals subjected to fast post-growth cool-down. Typical EPD values for lower cool-down rates and in regions not affected by wall interactions are in the lower 10(exp 4) sq cm range. In some areas the actual dislocation density was about 10(exp 3) sq cm or even less. No apparent effect of the cool-down rate on polygonization was observed. A fine structure could be discerned in low-temperature PL spectra of crystals with low dislocation density.

  1. Methodology Plan for Minimum Resolvable Temperature Difference (MRTD) Testing of Aircraft Installed Sensors

    DTIC Science & Technology

    2011-03-23

    sensors (e.g., sensor fusion) or use different detector materials to increase spectral bands into the Near IR (NIR). 3. Holst2provides an...a. Detector type: Multi-element MCT SPRITE b. Wavelength: Long wave, 8-12 um c. Cooling system: Integrated Sterling cooler d. Cooldown...A-1 B. COLLIMATOR SYSTEM DESIGN AND EO/ IR TOPICS ................ B-1 C. ATTC FACILITIES AND INSTRUMENTATION

  2. Design, fabrication, and structural testing of a lightweight shadow shield for deep-space application

    NASA Technical Reports Server (NTRS)

    Miao, D.; Barber, J. R.; Dewitt, R. L.

    1977-01-01

    Two full-scale, lightweight, double-sheeted shadow shields were developed as the primary element of a deep-space thermal protection system for liquid-hydrogen propellant tankage. The thermal and mechanical considerations used in s, the method of fabrication, and the environmental testing results on a prototype shield are discussed. Testing consisted of a transient cooldown period, a prolonged cold soak, and a transient warmup. The mechanical and thermal analyses used in the shield design are sufficient to produce a lightweight rugged shadow shield assembly that is structurally adequate for its intended application.

  3. Impact of cool-down conditions at Tc on the superconducting rf cavity quality factor

    NASA Astrophysics Data System (ADS)

    Vogt, J.-M.; Kugeler, O.; Knobloch, J.

    2013-10-01

    Many next-generation, high-gradient accelerator applications, from energy-recovery linacs to accelerator-driven systems (ADS) rely on continuous wave (CW) operation for which superconducting radio-frequency (SRF) systems are the enabling technology. However, while SRF cavities dissipate little power, they must be cooled by liquid helium and for many CW accelerators the complexity as well as the investment and operating costs of the cryoplant can prove to be prohibitive. We investigated ways to reduce the dynamic losses by improving the residual resistance (Rres) of niobium cavities. Both the material treatment and the magnetic shielding are known to have an impact. In addition, we found that Rres can be reduced significantly when the cool-down conditions during the superconducting phase transition of the niobium are optimized. We believe that not only do the cool-down conditions impact the level to which external magnetic flux is trapped in the cavity but also that thermoelectric currents are generated which in turn create additional flux that can be trapped. Therefore, we investigated the generation of flux and the dynamics of flux trapping and release in a simple model niobium-titanium system that mimics an SRF cavity in its helium tank. We indeed found that thermal gradients along the system during the superconducting transition can generate a thermoelectric current and magnetic flux, which subsequently can be trapped. These effects may explain the observed variation of the cavity’s Rres with cool-down conditions.

  4. Cooling the dark energy camera instrument

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schmitt, R.L.; Cease, H.; /Fermilab

    2008-06-01

    DECam, camera for the Dark Energy Survey (DES), is undergoing general design and component testing. For an overview see DePoy, et al in these proceedings. For a description of the imager, see Cease, et al in these proceedings. The CCD instrument will be mounted at the prime focus of the CTIO Blanco 4m telescope. The instrument temperature will be 173K with a heat load of 113W. In similar applications, cooling CCD instruments at the prime focus has been accomplished by three general methods. Liquid nitrogen reservoirs have been constructed to operate in any orientation, pulse tube cryocoolers have been usedmore » when tilt angles are limited and Joule-Thompson or Stirling cryocoolers have been used with smaller heat loads. Gifford-MacMahon cooling has been used at the Cassegrain but not at the prime focus. For DES, the combined requirements of high heat load, temperature stability, low vibration, operation in any orientation, liquid nitrogen cost and limited space available led to the design of a pumped, closed loop, circulating nitrogen system. At zenith the instrument will be twelve meters above the pump/cryocooler station. This cooling system expected to have a 10,000 hour maintenance interval. This paper will describe the engineering basis including the thermal model, unbalanced forces, cooldown time, the single and two-phase flow model.« less

  5. Life test result of Ricor K529N 1watt linear cryocooler

    NASA Astrophysics Data System (ADS)

    Nachman, Ilan; Veprik, Alexander; Pundak, Nachman

    2007-04-01

    The authors summarize the results of the accelerated life testing of the Ricor type K529N 1 Watt linear split Stirling cooler. The test was conducted in the period 2003-2006, during which the cooler accumulated in excess of 27,500 working hours at an elevated ambient temperature, which is equivalent to 45,000 hours at normal ambient conditions, and performed about 7,500 operational cycles including cooldown and steady-state phases. The cryocooler performances were assessed through the cooldown time and power consumption; no visible degradation in performances was observed. After the cooler failure and the compressor disassembling, an electrical short was discovered in the driving coil. The analysis has shown that the wire insulating varnish was not suitable for such elevated temperatures. It is important to note that the cooler under test was taken from the earliest engineering series; in the later manufacturing line military grade wire with high temperature insulation was used, no customer complaints have been recorded in this instance Special attention was paid to the thorough examination of the technical condition of the critical components of the cooler interior. In particular, dynamic piston-cylinder seal, flying leads, internal O-rings and driving coil were examined in the compressor. As to the cold head, we focused on studying the conditions of the dynamic bushing-plunger seal, O-rings and displacer-regenerator. In addition, a leak test was performed to assess the condition of the metallic crushed seals. From the analysis, the authors draw the conclusion that the cooler design is adequate for long life performance (in excess of 20,000 working hours) applications.

  6. Pilot Plant Testing of Hot Gas Building Decontamination Process

    DTIC Science & Technology

    1987-10-30

    last hours of the cooldown (after water traps in the line were installed) showed no detectable contamination from this station. 1 60 CwC -So 0) 0 o j...Since we will not require refrigeration, additional generators probably 0 qlill not be required. Water is trucked to the site. Agent contaminated water ...surface. The gauze was handled by forceps during all of the sampling steps to prevent contamination after the solvent extraction clean-up of the gauze pads

  7. Non-invasive measurement of brain temperature with microwave radiometry: demonstration in a head phantom and clinical case.

    PubMed

    Stauffer, Paul R; Snow, Brent W; Rodrigues, Dario B; Salahi, Sara; Oliveira, Tiago R; Reudink, Doug; Maccarini, Paolo F

    2014-02-01

    This study characterizes the sensitivity and accuracy of a non-invasive microwave radiometric thermometer intended for monitoring body core temperature directly in brain to assist rapid recovery from hypothermia such as occurs during surgical procedures. To study this approach, a human head model was constructed with separate brain and scalp regions consisting of tissue equivalent liquids circulating at independent temperatures on either side of intact skull. This test setup provided differential surface/deep tissue temperatures for quantifying sensitivity to change in brain temperature independent of scalp and surrounding environment. A single band radiometer was calibrated and tested in a multilayer model of the human head with differential scalp and brain temperature. Following calibration of a 500MHz bandwidth microwave radiometer in the head model, feasibility of clinical monitoring was assessed in a pediatric patient during a 2-hour surgery. The results of phantom testing showed that calculated radiometric equivalent brain temperature agreed within 0.4°C of measured temperature when the brain phantom was lowered 10°C and returned to original temperature (37°C), while scalp was maintained constant over a 4.6-hour experiment. The intended clinical use of this system was demonstrated by monitoring brain temperature during surgery of a pediatric patient. Over the 2-hour surgery, the radiometrically measured brain temperature tracked within 1-2°C of rectal and nasopharynx temperatures, except during rapid cooldown and heatup periods when brain temperature deviated 2-4°C from slower responding core temperature surrogates. In summary, the radiometer demonstrated long term stability, accuracy and sensitivity sufficient for clinical monitoring of deep brain temperature during surgery.

  8. Proceedings of the 1993 Particle Accelerator Conference Held in Washington, DC on May 17-20, 1993. Volume 2

    DTIC Science & Technology

    1993-05-20

    up/cool-down cycles have been made. A cool-down procedure which avoids the "Q- virus " problem has been identified. I. INTRODUCTION The first Cornell B...at Cornell the cavity attempt to identify our susceptibility to the "Q- virus ". All was rinsed with methanol sprayed at -40 psi, dried in a class tests...34Q- virus " (see [4] for the most recent summary of outbreaks and causes). The indication that Figure 3. Qo vs Eacc for the cavity test after etching. RF

  9. Efficacy of Cool-Down Exercises In the Practice Regimen of Elite Singers

    NASA Astrophysics Data System (ADS)

    Gottliebson, Renee O.

    Cool-down exercises are routinely prescribed for singers, yet few data exist about the efficacy of active recovery or cooling down of the vocal mechanism. The purpose of the present study was to compare three aspects of vocal function after using different recovery methods following rigorous voice use. Vocal function was assessed using (1) phonation threshold pressure (PTP); (2) acoustic measures (accuracy of tone production, duration of notes and duration of intervals between notes); and (3) measures of subjective perception: perceived phonatory effort (PPE) and Singing Voice Handicap Index (SVHI). Data were collected after 10-minutes of cool-down exercises, complete voice rest, and conversation immediately following a 50-minute voice lesson. Data were collected again 12-24 hours later. Participants included actively performing elite singers (7 women, 2 men) enrolled in the graduate program (M.M., D.M.A.) at the University of Cincinnati's College-Conservatory of Music. While it was expected that PTP estimates after cool downs would be significantly lower than baselines and the other conditions, it turns out that PTP estimates after cool downs were significantly higher at the 80% level of the pitch range. Statistically significant correlations between PTP estimates and PPE scores were found when comparing levels of the participants' pitch ranges (10%, 20%, 80%). Mean PPE scores were highest at the 80% level of the pitch range. The acoustic measures yielded variable results. Cool-down exercises did not result in significantly more accurate tone production and shorter staccato note duration and duration of intervals between staccato notes as compared to baselines and recovery conditions. Instead, participants demonstrated greater accuracy of tone production during baselines and lesser accuracy after voice rest. Staccato notes were significantly shorter in duration after the conversation condition as compared to voice rest. Duration between staccato notes was significantly shorter 12-24 hours after voice rest compared to baselines and the other follow-up conditions. SVHI mean scores were higher during baselines than after the recovery conditions and during follow-up sessions. Statistical significance is noted in comparison of mean SVHI scores 12-24 hours after cool downs (overall lowest mean score) and baselines. The relationship between vocal cool downs and their aerodynamic and acoustic effects remains unclear. What was found was that perhaps the perceived benefit of vocal cool downs is not apparent immediately after their use, but is evident 12-24 hours later. While it appears that conversation may be an acceptable form of active vocal recovery, cool-down exercises may be most beneficial as they raise a conscious awareness of optimum, resonant voice use which may carryover into conversational speech. Future research may benefit from examination of long-term use of vocal cool-down exercises in subsequent vocal performance.

  10. Aerogel Insulation Systems for Space Launch Applications

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.

    2005-01-01

    New developments in materials science in the areas of solution gelation processes and nanotechnology have led to the recent commercial production of aerogels. Concurrent with these advancements has been the development of new approaches to cryogenic thermal insulation systems. For example, thermal and physical characterizations of aerogel beads under cryogenic-vacuum conditions have been performed at the Cryogenics Test Laboratory of the NASA Kennedy Space Center. Aerogel-based insulation system demonstrations have also been conducted to improve performance for space launch applications. Subscale cryopumping experiments show the thermal insulating ability of these fully breathable nanoporous materials. For a properly executed thermal insulation system, these breathable aerogel systems are shown to not cryopump beyond the initial cooldown and thermal stabilization phase. New applications are being developed to augment the thermal protection systems of space launch vehicles, including the Space Shuttle External Tank. These applications include a cold-boundary temperature of 90 K with an ambient air environment in which both weather and flight aerodynamics are important considerations. Another application is a nitrogen-purged environment with a cold-boundary temperature of 20 K where both initial cooldown and launch ascent profiles must be considered. Experimental results and considerations for these flight system applications are discussed.

  11. Dynamic Simulation of AN Helium Refrigerator

    NASA Astrophysics Data System (ADS)

    Deschildre, C.; Barraud, A.; Bonnay, P.; Briend, P.; Girard, A.; Poncet, J. M.; Roussel, P.; Sequeira, S. E.

    2008-03-01

    A dynamic simulation of a large scale existing refrigerator has been performed using the software Aspen Hysys®. The model comprises the typical equipments of a cryogenic system: heat exchangers, expanders, helium phase separators and cold compressors. It represents the 400 W @ 1.8 K Test Facility located at CEA—Grenoble. This paper describes the model development and shows the possibilities and limitations of the dynamic module of Aspen Hysys®. Then, comparison between simulation results and experimental data are presented; the simulation of cooldown process was also performed.

  12. Improvement of cooldown time of LSF9599 flexure-bearing SADA cooler

    NASA Astrophysics Data System (ADS)

    Mullié, Jeroen; vd Groep, Willem; Bruins, Peter; Benschop, Tonny; de Koning, Arjan; Dam, Jacques

    2006-05-01

    Thales Cryogenics has presented the LSF 9599 SADA II flexure cooler in 2005. Based on Thales' well-known moving magnet flexure technology, the LSF 9599 complies with the SADA II specification with respect to performance, envelope and mass. Being the first manufacturer offering a full flexure-bearing supported cooler that fits within the SADA II envelope, Thales Cryogenics has been selected in several new (military) programs with their LSF coolers. For many of these new programs, the cooldown time requirements are more stringent than in the past, whereas at the same time size, complexity and thus thermal mass of the infrared sensor tends to increase. In order to respond to the need created by the combination of these trends, Thales Cryogenics started a development program to optimize cryogenic performance of the LSF 9599 cooler. The main goal for the development program is to reduce the cooldown time, while maintaining the SADA II compatible interface, and maintaining the robustness and proven reliability of the cooler. Within these constraints, the regenerator was further optimized using among others the experience with mixed-gauze regenerators obtained from our pulse tube research. Using the mixed gauze approach, the heat storage capacity of the regenerator is adapted as a function of the temperature profile over the regenerator, thus giving the optimum balance between heat storage capacity and pressure drop. A novel way of constructing the regenerator further decreases shuttle heat losses and other thermal losses in the regenerator. This paper describes the first results of the trade-offs and gives an overview of impact on cooldown times and efficiency figures achieved after the regenerator and displacer optimization.

  13. 120 Hz pulse tube cryocooler for fast cooldown to 50 K

    NASA Astrophysics Data System (ADS)

    Vanapalli, Srinivas; Lewis, Michael; Gan, Zhihua; Radebaugh, Ray

    2007-02-01

    A pulse tube cryocooler operating at 120Hz with 3.5MPa average pressure achieved a no-load temperature of about 49.9K and a cooldown time to 80K of 5.5min. The net refrigeration power at 80K was 3.35W with an efficiency of 19.7% of Carnot when referred to input pressure-volume (PV or acoustic) power. Such low temperatures have not been previously achieved for operating frequencies above 100Hz. The high frequency operation leads to reduced cryocooler volume for a given refrigeration power, which is important to many applications and can enable development of microcryocoolers for microelectromechanical system applications.

  14. Compact scanning tunneling microscope for spin polarization measurements.

    PubMed

    Kim, Seong Heon; de Lozanne, Alex

    2012-10-01

    We present a design for a scanning tunneling microscope that operates in ultrahigh vacuum down to liquid helium temperatures in magnetic fields up to 8 T. The main design philosophy is to keep everything compact in order to minimize the consumption of cryogens for initial cool-down and for extended operation. In order to achieve this, new ideas were implemented in the design of the microscope body, dewars, vacuum chamber, manipulators, support frame, and vibration isolation. After a brief description of these designs, the results of initial tests are presented.

  15. Operational present status and reliability analysis of the upgraded EAST cryogenic system

    NASA Astrophysics Data System (ADS)

    Zhou, Z. W.; Y Zhang, Q.; Lu, X. F.; Hu, L. B.; Zhu, P.

    2017-12-01

    Since the first commissioning in 2005, the cryogenic system for EAST (Experimental Advanced Superconducting Tokamak) has been cooled down and warmed up for thirteen experimental campaigns. In order to promote the refrigeration efficiencies and reliability, the EAST cryogenic system was upgraded gradually with new helium screw compressors and new dynamic gas bearing helium turbine expanders with eddy current brake to improve the original poor mechanical and operational performance from 2012 to 2015. Then the totally upgraded cryogenic system was put into operation in the eleventh cool-down experiment, and has been operated for the latest several experimental campaigns. The upgraded system has successfully coped with various normal operational modes during cool-down and 4.5 K steady-state operation under pulsed heat load from the tokamak as well as the abnormal fault modes including turbines protection stop. In this paper, the upgraded EAST cryogenic system including its functional analysis and new cryogenic control networks will be presented in detail. Also, its operational present status in the latest cool-down experiments will be presented and the system reliability will be analyzed, which shows a high reliability and low fault rate after upgrade. In the end, some future necessary work to meet the higher reliability requirement for future uninterrupted long-term experimental operation will also be proposed.

  16. Pretest analysis document for Semiscale Test S-FS-1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, T.H.

    This report documents the pretest analysis calculation completed with the RELAP5/MOD2/CY21 code for Semiscale Test S-FS-1. The test will simulate the double-ended offset shear of the main steam line at the exit of the broken loop steam generator (downstream of the flow restrictor) and the subsequent plant recovery. The recovery portion of the test consists of a plant stabilization phase and a plant cooldown phase. The recovery procedures involve normal charging/letdown operation, pressurizer heater operation, secondary steam and feed of the unaffected steam generator, and pressurizer auxiliary spray. The test will be terminated after the unaffected steam generator and pressurizermore » pressures and liquid levels are stable, and the average priamry fluid temperature is stable at about 480 K (405/sup 0/F) for at least 10 minutes.« less

  17. Analysis, testing, and operation of the MAGI thermal control system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yi, Sonny; Hall, Jeffrey L.; Kasper, Brian P.

    2014-01-29

    The Aerospace Corporation has completed the development of the Mineral and Gas Identifier (MAGI) sensor - an airborne multi-spectral infrared instrument that is designed to discriminate surface composition and to detect gas emissions from the environment. Sensor performance was demonstrated in a series of flights aboard a Twin Otter aircraft in December 2011 as a stepping stone to a future satellite sensor design. To meet sensor performance requirements the thermal control system was designed to operate the HgCdTe focal plane array (FPA) at 50 K with a 1.79 W heat rejection load to a 44.7 K sink and the opticalmore » assembly at 100 K with a 7.5 W heat load to a 82.3 K sink. Two commercial off-theshelf (COTS) Sunpower Stirling cryocoolers were used to meet the instrument’s cooling requirements. A thermal model constructed in Thermal Desktop was used to run parametric studies that guided the mechanical design and sized the two cryocoolers. This paper discusses the development, validation, and operation of the MAGI thermal control system. Detailed energy balances and temperature predictions are presented for various test cases to demonstrate the utility and accuracy of the thermal model. Model inputs included measured values of heat lift as a function of input power and cold tip temperature for the two cryocoolers. These measurements were also used to make predictions of the cool-down behavior from ambient conditions. Advanced heater software was developed to meet unique requirements for both sensor cool-down rate and stability at the set point temperatures.« less

  18. Successful Completion of the JWST OGSE2 Cryogenic Test at JSC Chamber-A While Managing Numerous Challenges

    NASA Technical Reports Server (NTRS)

    Park, Sang C.; Brinckerhoff, Pamela; Franck, Randy; Schweickart, Rusty; Thomson, Shaun; Burt, Bill; Ousley, Wes

    2016-01-01

    The James Webb Space Telescope (JWST) Optical Telescope Element (OTE) assembly is the largest optically stable infrared-optimized telescope currently being manufactured and assembled, and scheduled for launch in 2018. The JWST OTE, including the primary mirrors, secondary mirror, and the Aft Optics Subsystems (AOS) are designed to be passively cooled and operate at near 45 degrees Kelvin. Due to the size of its large sunshield in relation to existing test facilities, JWST cannot be optically or thermally tested as a complete observatory-level system at flight temperatures. As a result, the telescope portion along with its instrument complement will be tested as a single unit very late in the program, and on the program schedule critical path. To mitigate schedule risks, a set of 'pathfinder' cryogenic tests will be performed to reduce program risks by demonstrating the optical testing capabilities of the facility, characterizing telescope thermal performance, and allowing project personnel to learn valuable testing lessons off-line. This paper describes the 'pathfinder' cryogenic test program, focusing on the recently completed second test in the series called the Optical Ground Support Equipment 2 (OGSE2) test. The JWST OGSE2 was successfully completed within the allocated project schedule while faced with numerous conflicting thermal requirements during cool-down to the final cryogenic operational temperatures, and during warm-up after the cryo-stable optical tests. The challenges include developing a pre-test cool-down and warm-up profiles without a reliable method to predict the thermal behaviors in a rarified helium environment, and managing the test article hardware safety driven by the project Limits and Constraints (L&C's). Furthermore, OGSE2 test included the time critical Aft Optics Subsystem (AOS), a part of the flight Optical Telescope Element that would need to be placed back in the overall telescope assembly integrations. The OGSE2 test requirements included the strict adherence of the project contamination controls due to the presence of the contamination sensitive flight optical elements. The test operations required close coordination of numerous personnel while they being exposed and trained for the 'final' combined OTE and instrument cryo-test in 2017. This paper will also encompass the OGSE2 thermal data look-back review.

  19. Study of cryogenic propellant systems for loading the space shuttle. Part 2: Hydrogen systems

    NASA Technical Reports Server (NTRS)

    Steward, W. G.

    1975-01-01

    Computer simulation studies of liquid hydrogen fill and vent systems for the space shuttle are studied. The computer programs calculate maximum and minimum permissible flow rates during cooldown as limited by thermal stress considerations, fill line cooldown time, pressure drop, flow rates, vapor content, vent line pressure drop and vent line discharge temperature. The input data for these programs are selected through graphic displays which schematically depict the part of the system being analyzed. The computed output is also displayed in the form of printed messages and graphs. Digital readouts of graph coordinates may also be obtained. Procedures are given for operation of the graphic display unit and the associated minicomputer and timesharing computer.

  20. Electrical heating tests of uranium dioxide external fuel configuration at emitter temperature of 1900 K

    NASA Technical Reports Server (NTRS)

    Diianni, D. C.; Mayer, J. T.

    1974-01-01

    Testing of two fuel clad specimens for thermionic reactor application is described. The annular UO2 fuel was clad on both sides with tungsten; heat rejection was radially inward. The tests were intended to study inner clad stability, fuel redistribution, and fuel melting problems. The specimens were tested in a vacuum chamber using electron bombardment heating. Fuel structural changes were studied using periodic gammagraphs and posttest metallography. The first specimen test was terminated at 50 hours because of a braze failure. The second specimen was tested for 240 hours when an outer clad leak developed due to a tungsten-water reaction. The fuel developed numerous cracks on cooldown but the inner clad remained dimensionally stable. The fuel cover gas did not impede the rate of fuel redistribution. Posttest examination showed the fuel had not melted during operation.

  1. Design features and operational characteristics of the Langley 0.3-meter transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1976-01-01

    Experience with the Langley 0.3 meter transonic cryogenic tunnel, which is fan driven, indicated that such a tunnel presents no unusual design difficulties and is simple to operate. Purging, cooldown, and warmup times were acceptable and were predicted with good accuracy. Cooling with liquid nitrogen was practical over a wide range of operating conditions at power levels required for transonic testing, and good temperature distributions were obtained by using a simple liquid nitrogen injection system. To take full advantage of the unique Reynolds number capabilities of the 0.3 meter transonic tunnel, it was designed to accommodate test sections other than the original, octagonal, three dimensional test section. A 20- by 60-cm two dimensional test section was recently installed and is being calibrated. A two dimensional test section with self-streamlining walls and a test section incorporating a magnetic suspension and balance system are being considered.

  2. Reducing the Liquid Helium Consumption of Superconducting Rock Magnetometers (SRMs) used in Paleomagnetic and Rock Magnetic studies: Gallium Lubrication of Gifford-McMahon Cryocoolers Leads to a Dramatic Increase in Cool-down Efficiency, and a Drop in Liquid Helium Consumption

    NASA Astrophysics Data System (ADS)

    Kirschvink, J. L.

    2015-12-01

    Two-stage Gifford-McMahon helium-gas cryocoolers have been used for the past 40+ years in a wide variety of cryogenic applications, including reducing the liquid helium consumption of SRMs. However, the cooling efficiency depends greatly on the friction of the displacement pistons, which need to be replaced every few years. This and the rising cost of liquid helium are major headaches in the operation of modern paleomagnetic laboratories. Although the development of efficient pulse-tube cryocoolers has eliminated the need for liquid helium in new superconducting magnetometers, there are still nearly 100 older SRMs around the globe that use liquid helium. In a failed attempt to replace the Gifford-McMahon unit on one of Caltech's SRMs with a pulse-tube, we irreversibly contaminated the cylindrical surfaces of the stainless-steel heat exchanger with a thin film of gallium, a non-toxic metal that has a melting temperature of ~ 30˚C. Liquid gallium will diffuse into other metals, altering their surface properties. We noticed that the next cryocooler-assisted cool down of the SRM went nearly twice as fast as in previous cycles, and the helium boiloff rate for the past 2 years has stabilized at less than half of its average over the past 30 years. It seems that the thin layer of gallium may be reducing the sliding friction of the Gifford-McMahon cryocoolers. We recently tested this on a second SRM, with similar results. We found that the inner cryocooler surface reached its equilibrium temperature in about 1/3 of the time that it took in previous cool-down cycles. WSGI also confirmed that this cool-down was unusually efficient compared to other instruments they have built. Subsequent records of the helium gas boiloff show that this system is also running at about half of its former loss rate. Based on these two results, we tentatively recommend this simple procedure any time cold-head swaps are performed on these cryocoolers.

  3. Energy saver A-sector power test results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martin, P.; Flora, R.; Tool, G.

    1982-09-15

    The superconducting magnets and associated cryogenic components in A-sector represent the initial phase of installation of the Fermilab superconducting accelerator, designed to accelerate proton beams to energies of 1 TeV. Installation of the magnets, comprising one-eighth of the ring, was completed in December, 1981. Cooldown and power tests took place in the first half of 1982, concurrent with main ring use for 400 GeV high energy physics. The tests described in this paper involved 151 cryogenic components in the tunnel: 94 dipoles, 24 quadrupoles, 25 spool pieces, 3 feed cans, 4 turn-around boxes and 1 bypass. Refrigeration was supplied bymore » three satellite refrigerators, the Central Helium Liquefier, and two compressor buildings. The magnets were powered by a single power supply.« less

  4. Exploratory screening tests of several alloys and coatings for automobile thermal reactors

    NASA Technical Reports Server (NTRS)

    Oldrieve, R. E.

    1971-01-01

    A total of 23 materials (including uncoated ferritic and austenitic iron-base alloys, uncoated nickel and cobalt-base superalloys, and several different coatings on AISI 304 stainless steel) were screened as test coupons on a rack in an automobile thermal reactor. Test exposures were generally 51 hours including 142 thermal cycles of 10 minutes at 1010 + or - 30 C test coupon temperature and 7-minutes cool-down to about 510 C. Materials that exhibited corrosion resistance better than that of Hastelloy X include: a ferritic iron alloy with 6 weight percent aluminum; three nickel-base superalloys; two diffused-aluminum coatings on AISI 304; and a Ni-Cr slurry-sprayed coating on AISI 304. Preliminary comparison is made on the performance of the directly impinged coupons and a reactor core of the same material.

  5. The Effect of the Wall Contact and Post-Growth, Cool-Down on Defects in CdTe Crystals Grown By 'Contactless' PVT

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Grasza, K.; Dudley, M.; Raghothamachar, B.; Cai, L.; Dunrose, K.; Halliday, D.; Boyall, N. M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    To take a maximum advantage of materials processing in microgravity for understanding the effects of gravity, gravity-independent effects should be minimized. In crystal growth, the quality of the grown crystals may depend, among other factors, on their interaction with the walls of the processing container during and after growth, and on the rate of the crystal cool-down at the end of the process. To investigate the above phenomena, a series of CdTe crystal growth processes was carried out. The crystals were grown by physical vapor transport without contact with the side walls of the silica glass ampoules. To eliminate the effect of the seed quality, and to reduce the number of nuclei and related crystal grains, the Low Supersaturation Nucleation technique was applied. The source temperature was 930 C, the undercooling was a few degrees. The crystals, having the diameter of 25 mm, grew at the rate of a few mm per day. The post-growth cool-down to the room temperature was conducted at different rates, and lasted from a few minutes to four days. The crystals were characterized using chemical etching, low temperature luminescence, and Synchrotron White Beam X-ray Topography techniques. The dislocation (etch pit) density was measured and its distribution was analyzed by comparison with Poisson curves and with the Normalized Radial Distribution Correlation Function. In the regions where the crystal is in contact with silica, the materials show a considerable strain field which extends for a few mm or more from the silica-crystal interface. In the reference crystal grown with contact with the ampoule walls, and when the crystals are cooled at the highest rates, the etch pit/dislocation density is in the high 10(exp 5) per square centimeter region. Typical EPD values for lower cool-down rates are in the lower 10(exp 4) per square centimeter region. In some areas the actual dislocation density was about 10(exp 3) per square centimeter or even less. No apparent effect of the cool-down rate on polygonization was observed. Low temperature PL spectra show, that the dominant peak is (D(sup 0), h) and (A(sup 0), e) for samples with low and high dislocation densities, respectively. For low EPD crystals a peak at 1.45 eV with 21 meV phonon replicas was observed and attributed to donor-acceptor pair to neutral copper-acceptor transition. In high EPD crystals this PL structure was not observed, apparently due to the masking effect of the strong contribution from the dislocation band.

  6. Environmental Qualification of a Single-Crystal Silicon Mirror for Spaceflight Use

    NASA Technical Reports Server (NTRS)

    Hagopian, John; Chambers, John; Rohrback. Scott; Bly, Vincent; Morell, Armando; Budinoff, Jason

    2013-01-01

    This innovation is the environmental qualification of a single-crystal silicon mirror for spaceflight use. The single-crystal silicon mirror technology is a previous innovation, but until now, a mirror of this type has not been qualified for spaceflight use. The qualification steps included mounting, gravity change measurements, vibration testing, vibration- induced change measurements, thermal cycling, and testing at the cold operational temperature of 225 K. Typical mirrors used for cold applications for spaceflight instruments include aluminum, beryllium, glasses, and glass-like ceramics. These materials show less than ideal behavior after cooldown. Single-crystal silicon has been demonstrated to have the smallest change due to temperature change, but has not been spaceflight-qualified for use. The advantage of using a silicon substrate is with temperature stability, since it is formed from a stress-free single crystal. This has been shown in previous testing. Mounting and environmental qualification have not been shown until this testing.

  7. Commissioning and operation of the horizontal test apparatus at SNS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Sang-Ho; Neustadt, Thomas S.; Howell, Matthew P.

    2015-07-01

    The Spallation Neutron Source (SNS) at Oak Ridge National Lab (ORNL) has built, commissioned and operated a Horizontal Test Apparatus (HTA) vessel in the Radiofrequency Test Facility (RFTF) test cave. It can be operated at 4.5 K using the independent Cryogenic Test Facility (CTF). The HTA is designed to be a single cavity version of an SNS cryomodule with the ability to demount and replace the cavity. It provides the functionality for testing a single dressed SNS medium or high beta Superconducting Radiofrequency (SRF) cavity. The HTA is currently being used in support of R&D for in-situ plasma processing ofmore » the cavity's inner niobium surface. The design and commissioning of the HTA at 4.5 K will be presented as well as results from operating the HTA including cool-down, warm-up and steady state operations. Results from plasma processing a warm SCRF cavity in-between cold HTA tests will also be reported.« less

  8. New class of microminiature Joule — Thomson refrigerator and vacuum package

    NASA Astrophysics Data System (ADS)

    Paugh, Robert L.

    1990-12-01

    Progress is reported on the development of a two-stage, fast cooldown Joule — Thomson refrigerator using nitrogen gas and a nitrogen — hydrocarbon gas mixture as the refrigerants. The refrigerator incorporates a microminiature Venturi pump to reduce the pressure of the exhaust of the main boiler to bring the operating temperature of the cold stage to < 70 K in as little as 10 s. The vacuum package for the refrigerator contains no organic materials and is designed to provide a ten year shelf life. Special glass strengthening techniques are being used to achieve cooler survival of acceleration tests of up to 100 000g.

  9. The Critical Thinking Workout.

    ERIC Educational Resources Information Center

    Masters, Terry McDaniel

    1991-01-01

    Presents a critical thinking exercise program, modeled on a physical exercise workout, for elementary teachers to use in the classroom. It includes warm-up exercises, a more strenuous workout, and a cool-down period for the brain. (SM)

  10. BaBar superconducting coil: design, construction and test

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, R A; Berndt, M; Burgess, W

    2001-01-26

    The BABAR Detector, located in the PEP-II B-Factory at the Stanford Linear Accelerator Center, includes a large 1.5 Tesla superconducting solenoid, 2.8 m bore and length 3.7 m. The two layer solenoid is wound with an aluminum stabilized conductor which is graded axially to produce a {+-} 3% field uniformity in the tracking region. This paper summarizes the 3 year design, fabrication and testing program of the superconducting solenoid. The work was carried out by an international collaboration between INFN, LLNL and SLAC. The coil was constructed by Ansaldo Energia. Critical current measurements of the superconducting strand, cable and conductor,more » cool-down, operation with the thermo-siphon cooling, fast and slow discharges, and magnetic forces are discussed in detail.« less

  11. Maintaining Flatness of a Large Aperture Potassium Bromide Beamsplitter Through Mounting and Vibration

    NASA Technical Reports Server (NTRS)

    Losch, Patricia; Lyons, James J., III; Morell, Armando; Heaney, Jim

    1998-01-01

    The Composite Infrared Spectrometer (CIRS) instrument on the Cassini Mission launched in October of 1997. The CIRS instrument contains a mid-infrared (MIR) and a far-infrared interferometer (FIR) and operates at 170 Kelvin. The MIR is a Michelson Fourier transform spectrometer utilizing a 76 mm (3 inch) diameter potassium bromide beamsplitter and compensator pair. The potassium bromide elements were tested to verify effects of cooldown and vibration prior to integration into the instrument. The instrument was then aligned at ambient temperatures, tested cryogenically and re-verified after vibration. 'Me stringent design optical figure requirements for the beamsplitter and compensator included fabrication errors, mounting stresses and vibration load effects. This paper describes the challenges encountered in mounting the elements to minimize distortion and to survive vibration.

  12. Maintaining Flatness of a Large Aperture Potassium Bromide Beamsplitter through Mounting and Vibration

    NASA Technical Reports Server (NTRS)

    Losch, Patricia; Lyons, James, III; Morell, Armando; Heaney, Jim

    1998-01-01

    The Composite Infrared Spectrometer (CIRS) instrument on the Cassini Mission launched in October of 1997. The CIRS instrument contains a mid-infrared and a far-infrared interferometer and operates at 170 Kelvin. The mid-infrared interferometer is a Michelson- type Fourier transform spectrometer utilizing a 3 inch diameter potassium bromide beamsplitter/compensator pair. The potassium bromide elements were tested to verify effects of cooldown and vibration prior to integration into the instrument. The instrument was then aligned at ambient temperatures, tested cryogenically and re-verified after vibration. The stringent design optical figure requirements for the beamsplitter and compensator included fabrication errors, mounting stresses and vibration load effects. This paper describes the challenges encountered in mounting the elements to minimize distortion and to survive vibration.

  13. Final report on testing of TOPAZ II unit Ya-21u: Output power characteristics and system capabilities

    NASA Astrophysics Data System (ADS)

    Luchau, David W.; Sinkevich, Valery G.; Wernsman, Bernard; Mulder, Daniel M.

    1996-03-01

    A final report on the output power characteristics and capabilities of the TOPAZ II Space Nuclear Power Unit Ya-21u is presented. Results showed that after a total of almost 8,000 hours of system testing in the U.S. and Russia, several emergency cooldowns, and three inadvertent air introductions to the interelectrode gap (IEG) that the TOPAZ II demonstrates the potential for providing reliable power in a space environment. Output power optimizations and system characteristics following a shock and vibration test are shown. These tests were performed using electrical heaters that simulate nuclear fuel heating. This paper will focus primarily on the changes in output power characteristics over the lifetime of Ya-21u. All U.S. testing was conducted at the Thermionic System Evaluation Test (TSET) Facility of the New Mexico Engineering Research Institute (NMERI) as a part of the TOPAZ International Program (TIP). TIP is managed by the Air Force Phillips Laboratory (PL) for the Ballistic Missile Defense Organization (BMDO).

  14. Cool-Down and Current Test Results of the KSTAR Prototype TF Coil

    NASA Astrophysics Data System (ADS)

    Oh, Y. K.; Lee, S.; Chu, Y.; Park, K. R.; Yonekawa, H.; Baek, S. H.; Cho, K. W.; Park, Y. M.; Kim, M. K.; Chang, H. S.; Kim, Y. S.; Chang, Y. B.; Lee, Y. J.; Kim, W. C.; Kim, K.; Kwag, S. W.; Lee, S. H.; Yang, S. H.; Lee, S. J.; Bak, J. S.; Lee, G. S.

    2004-06-01

    A prototype toroidal field (TF) coil, TF00 coil, of the Korea Superconducting Tokamak Advanced Research (KSTAR) project has been assembled and tested at the coil test facility in Korea Basic Science Institute (KBSI). The TF00 coil is a real-sized TF coil made of Nb3Sn superconducting cable-in-conduit conductor (CICC). The coil test was conducted by several campaigns according to the objectives. The first campaign, which was carried out by Jan. 2003, has objectives of cooling the coil into operating temperature and finding any defect in the coil such as cold leaks. From the results of the first campaign experiment, any defect in the coil was not found. The second campaign, which was carried out by Aug. 2003, has objectives to get the operating characteristics according to the current ramp up and discharge operations. In this paper, the coil test results are introduced as well as the details of the coil test system setup.

  15. Cool-down flow-rate limits imposed by thermal stresses in LNG pipelines

    NASA Astrophysics Data System (ADS)

    Novak, J. K.; Edeskuty, F. J.; Bartlit, J. R.

    Warm cryogenic pipelines are usually cooled to operating temperature by a small, steady flow of the liquid cryogen. If this flow rate is too high or too low, undesirable stresses will be produced. Low flow-rate limits based on avoidance of stratified two-phase flow were calculated for pipelines cooled with liquid hydrogen or nitrogen. High flow-rate limits for stainless steel and aluminum pipelines cooled by liquid hydrogen or nitrogen were determined by calculating thermal stress in thick components vs flow rate and then selecting some reasonable stress limits. The present work extends these calculations to pipelines made of AISI 304 stainless steel, 6061 aluminum, or ASTM A420 9% nickel steel cooled by liquid methane or a typical natural gas. Results indicate that aluminum and 9% nickel steel components can tolerate very high cool-down flow rates, based on not exceeding the material yield strength.

  16. LCLS-II 1.3 GHz cryomodule design - lessons learned from testing at Fermilab

    NASA Astrophysics Data System (ADS)

    Kaluzny, J.; Hurd, J.; Orlov, Y.; He, Y.; Bossert, R.; Grimm, C.; Schappert, W.; Atassi, O. Al; Wang, R.; Arkan, T.; Theilacker, J.; Klebaner, A.; White, M.; Wu, G.; Makara, J.; Ginsburg, C.; Pei, L.; Holzbauer, J.; Hansen, B.; Stanek, R.; Peterson, T.; Harms, E.

    2017-12-01

    Fermilab’s 1.3 GHz prototype cryomodule for the Linac Coherent Light Source Upgrade (LCLS-II) has been tested at Fermilab’s Cryomodule Test Facility (CMTF). Aspects of the cryomodule design have been studied and tested. The cooldown circuit was used to quickly cool the cavities through the transition temperature, and a heater on the circuit was used to heat incoming helium for warmup. Due to the 0.5% slope of the cryomodule, the liquid level is not constant along the length of the cryomodule. This slope as well as the pressure profile caused liquid level management to be a challenge. The microphonics levels in the cryomodule were studied and efforts were made to reduce them throughout testing. Some of the design approaches and studies performed on these aspects will be presented. Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy. This work was supported, in part, by the LCLS-II Project.

  17. Elastic-Plastic Thermal Stress Analysis of a High-Pressure Cryogenic Storage Tank

    NASA Technical Reports Server (NTRS)

    Barker, J. Mark; Field, Robert E. (Technical Monitor)

    2003-01-01

    The thermal stresses on a cryogenic storage tank contribute strongly to the state of stress of the tank material and its ability to withstand operational stresses. These thermal stresses also affect the growth of any surface damage that might occur in the tank walls. These stresses are particularly of concern during the initial cooldown period for a new tank placed into service, and during any subsequent thermal cycles. A previous preliminary elastic analysis showed that the thermal stress on the inner wall would reach approximately 1,000MPa (145,000 psi). This stress far exceeds the ASTM specified room temperature values for both yield (170MPa) and ultimate (485 MPa) strength for 304L stainless steel. The present analysis determines the thermal stresses using an elastic-plastic model. The commercial software application ANSYS was used to determine the transient spatial temperature profile and the associated spatial thermal stress profiles in a segment of a thick-walled vessel during a typical cooldown process. A strictly elastic analysis using standard material properties for 304L stainless steel showed that the maximum thermal stress on the inner and outer walls was approximately 960 MPa (tensile) and - 270 MPa (compressive) respectively. These values occurred early in the cooldown process, but at different times, An elastic-plastic analysis showed significantly reducing stress, as expected due to the plastic deformation of the material. The maximum stress for the inner wall was approximately 225 MPa (tensile), while the maximum stress for the outer wall was approximately - 130 MPa (compressive).

  18. The Path to High Q-Factors in Superconducting Accelerating Cavities: Flux Expulsion and Surface Resistance Optimization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martinello, Martina

    Accelerating cavities are devices resonating in the radio-frequency (RF) range used to accelerate charged particles in accelerators. Superconducting accelerating cavities are made out of niobium and operate at the liquid helium temperature. Even if superconducting, these resonating structures have some RF driven surface resistance that causes power dissipation. In order to decrease as much as possible the power losses, the cavity quality factor must be increased by decreasing the surface resistance. In this dissertation, the RF surface resistance is analyzed for a large variety of cavities made with different state-of-the-art surface treatments, with the goal of finding the surface treatmentmore » capable to return the highest Q-factor values in a cryomodule-like environment. This study analyzes not only the superconducting properties described by the BCS surface resistance, which is the contribution that takes into account dissipation due to quasi-particle excitations, but also the increasing of the surface resistance due to trapped flux. When cavities are cooled down below their critical temperature inside a cryomodule, there is always some remnant magnetic field that may be trapped increasing the global RF surface resistance. This thesis also analyzes how the fraction of external magnetic field, which is actually trapped in the cavity during the cooldown, can be minimized. This study is performed on an elliptical single-cell horizontally cooled cavity, resembling the geometry of cavities cooled in accelerator cryomodules. The horizontal cooldown study reveals that, as in case of the vertical cooldown, when the cooling is performed fast, large thermal gradients are created along the cavity helping magnetic flux expulsion. However, for this geometry the complete magnetic flux expulsion from the cavity equator is more difficult to achieve. This becomes even more challenging in presence of orthogonal magnetic field, that is easily trapped on top of the cavity equator causing temperature rising. The physics behind the magnetic flux expulsion is also analyzed, showing that during a fast cooldown the magnetic field structures, called vortices, tend to move in the same direction of the thermal gradient, from the Meissner state region to the mixed state region, minimizing the Gibbs free energy. On the other hand, during a slow cool down, not only the vortices movement is limited by the absence of thermal gradients, but, also, at the end of the superconducting transition, the magnetic field concentrates along randomly distributed normal-conducting region from which it cannot be expelled anymore. The systematic study of the surface resistance components performed for the different surface treatments, reveals that the BCS surface resistance and the trapped flux surface resistance have opposite trends as a function of the surface impurity content, defined by the mean free path. At medium field value, the BCS surface resistance is minimized for nitrogen-doped cavities and significantly larger for standard niobium cavities. On the other hand, Nitrogen-doped cavities show larger dissipation due to trapped flux. This is consequence of the bell-shaped trend of the trapped flux sensitivity as a function of the mean free path. Such experimental findings allow also a better understanding of the RF dissipation due to trapped flux. The best compromise between all the surface resistance components, taking into account the possibility of trapping some external magnetic field, is given by light nitrogen-doping treatments. However, the beneficial effects of the nitrogen-doping is completely lost when large amount of magnetic field is trapped during the cooldown, underlying the importance of both cooldown and magnetic field shielding optimization in high quality factors cryomodules.« less

  19. (abstract) Simple Spreadsheet Thermal Models for Cryogenic Applications

    NASA Technical Reports Server (NTRS)

    Nash, A. E.

    1994-01-01

    Self consistent circuit analog thermal models, that can be run in commercial spreadsheet programs on personal computers, have been created to calculate the cooldown and steady state performance of cryogen cooled Dewars. The models include temperature dependent conduction and radiation effects. The outputs of the models provide temperature distribution and Dewar performance information. These models have been used to analyze the Cryogenic Telescope Test Facility (CTTF). The facility will be on line in early 1995 for its first user, the Infrared Telescope Technology Testbed (ITTT), for the Space Infrared Telescope Facility (SIRTF) at JPL. The model algorithm as well as a comparison of the model predictions and actual performance of this facility will be presented.

  20. Simple Spreadsheet Thermal Models for Cryogenic Applications

    NASA Technical Reports Server (NTRS)

    Nash, Alfred

    1995-01-01

    Self consistent circuit analog thermal models that can be run in commercial spreadsheet programs on personal computers have been created to calculate the cooldown and steady state performance of cryogen cooled Dewars. The models include temperature dependent conduction and radiation effects. The outputs of the models provide temperature distribution and Dewar performance information. these models have been used to analyze the SIRTF Telescope Test Facility (STTF). The facility has been brought on line for its first user, the Infrared Telescope Technology Testbed (ITTT), for the Space Infrared Telescope Facility (SIRTF) at JPL. The model algorithm as well as a comparison between the models' predictions and actual performance of this facility will be presented.

  1. Composite Materials for Structural Design.

    DTIC Science & Technology

    1982-03-01

    location of failure initiation. Accurate results for the third require additional considerations not treated here. 49 ABSTRACT Tranverse Shear Deformation...mentioned competing effects so as to minimize the residual thermal stress at the termination of the cool-down phase. Elastic Analysis Consider a symmetric

  2. Effects of a Single-Session Cognitive Enhancement Fitness Program on Serum Brain-Derived Neurotrophic Factor Levels and Cognitive Function in Middle-Aged Women.

    PubMed

    Kim, Hyun Jun; Lee, Sang Yeoup; Lee, Hwa Gyeong; Cho, Yang Hee; Ko, Eun Mi

    2018-03-01

    Few studies have been undertaken to develop cognitive functional improvement-focused exercise programs and determine their effect. The objectives of this study were to evaluate the effects of a cognitive enhancement fitness program (CEFP) on short-term memory and serum brain-derived neurotrophic factor (BDNF) levels according to the cognitive state in middle-aged women. A total of 30 healthy volunteers aged 40-59 years were divided into two groups, that is, a mild cognitive impairment (MCI) group and a non-MCI group based on results from the Korean Dementia Screening Questionnaire. A single-session CEFP was conducted over 50 min and consisted of four parts: warm-up, low intensity interval circulation dance exercises, moderate intensity resistance exercises using elastic bands, and cool-down. Serum BDNF levels were measured by ELISA and short-term memory determined by forward digit/word span test was assessed before and after CEFP. After CEFP, forward digit/word span test scores and BDNF levels increased to median 119.2%/115.1% and 118.7%, respectively. After CEFP, the MCI and non-MCI groups produced higher forward digit span test scores (from 6.7 ± 1.5 to 7.5 ± 1.4 points, p = 0.023 and from 6.2 ± 2.0 to 7.0 ± 2.1 points, P =0.011, respectively). After CEFP, forward word span scores and BDNF levels increased (from 3.5 ± 1.7 to 4.6 ± 1.8 points, p = 0.029 and from 610.8 ± 221.1 to 757.9 ± 267.9 pg/ml, p = 0.017, respectively) in non-MCI group only. No group differences were observed between change in short-term memory and change in BDNF. Short-term memory and BDNF levels after CEFP were found to be negatively correlated with age, but pre- to post-intervention changes in short-term memory and BDNF were not. The present study shows that a single, 50-minute CEFP improved short-term memory and increased serum BDNF levels in healthy middle-aged women, especially those without MCI.

  3. Let's Get Fit!: Fitness Activities for Children with Severe/Profound Disabilities.

    ERIC Educational Resources Information Center

    Modell, Scott J.; Cox, Thomas Alan

    1999-01-01

    Guidelines for developing a physical activity program for students with severe/profound disabilities address medical clearance; levels of participation; staffing; equipment; and program components, including warm-up, range of motion/flexibility activities, aerobics, resistance training, and cool-down. (DB)

  4. Operational and troubleshooting experiences in the SST-1 cryogenic system

    NASA Astrophysics Data System (ADS)

    Mahesuria, G.; Panchal, P.; Panchal, R.; Patel, R.; Sonara, D.; Gupta, N. C.; Srikanth, G. L. N.; Christian, D.; Garg, A.; Bairagi, N.; Patel, K.; Shah, P.; Nimavat, H.; Sharma, R.; Patel, J. C.; Tank, J.; Tanna, V. L.; Pradhan, S.

    2014-01-01

    Recently, the cooldown and current charging campaign have been carried out towards the demonstration of the first successful plasma discharge in the steady state superconducting Tokomak (SST-1). The SST-1 machine consists of cable-in-conduit wound superconducting toroidal as well as poloidal coils, cooled using 1.3 kW at 4.5 K helium refrigerator -cum- liquefier (HRL) system. The cryo system provides the two-phase helium at 0.13 MPa at 4.5 K as well as forced-flow pressurized helium at 0.4 MPa and in addition to 7 g-s-1 liquefaction capacity required for the current leads and other cold mass at 4.5 K. The entire integrated cold masses having different thermo hydraulic resistances cooled with the SST-1 HRL in optimised process parameters. In order to maintain different levels of temperatures and to facilitate smooth and reliable cooldown, warm-up, normal operations as well as to handle abnormal events such as, quench or utilities failures etc., exergy efficient process are adopted for the helium refrigerator-cum-liquefier (HRL) with an installed equivalent capacity of 1.3 kW at 4.5 K. Using the HRL, the cold mass of about 40 tons is being routinely cooled down from ambient temperature to 4.5 K with an average cooldown rate of 0.75 - 1 K-h-1. Long-term cryogenic stable conditions were obtained within 15 days in the superconducting coils and their connecting feeders. Afterwards, all of the cold mass is warmed-up in a controlled manner to ambient temperature. In this paper, we report the recent operational results of the cryogenic system during the first plasma discharge in SST-1 as well as the troubleshooting experiences of the cryogenic plant related hardware.

  5. Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber A

    NASA Technical Reports Server (NTRS)

    Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Garcia, S.; Garza, J.

    2013-01-01

    NASA s Space Environment Simulation Laboratory s (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN cooling with centrifugal pumps, requiring 220,000 liters of LN to cool-down and consuming 180,000 liters per day of LN in steady operation. The LN system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the subcontractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC s request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 68,000 liters to cool-down and less than 91,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system.

  6. Commissioning of the Liquid Nitrogen Thermo-Siphon System for NASA-JSC Chamber-A

    NASA Technical Reports Server (NTRS)

    Homan, J.; Montz, M.; Ganni, V.; Sidi-Yekhlef, A.; Knudsen, P.; Garcia, S.; Garza, J.

    2013-01-01

    NASA's Space Environment Simulation Laboratory's (SESL) Chamber A, located at the Johnson Space Center in Houston Texas has recently implemented major enhancements of its cryogenic and vacuum systems. The new liquid nitrogen (LN2) thermo-siphon system was successfully commissioned in August of 2012. Chamber A, which has 20 K helium cryo-panels (or shrouds ) which are shielded by 80 K nitrogen shrouds, is capable of simulating a deep space environment necessary to perform ground testing of NASA s James Webb Space Telescope (JWST). Chamber A s previous system used forced flow LN2 cooling with centrifugal pumps, requiring 200,000 liters of LN2 to cool-down and consuming 180,000 liters per day of LN2 in steady operation. The LN2 system did not have the reliability required to meet the long duration test of the JWST, and the cost estimate provided in the initial approach to NASA-JSC by the sub-contractor for refurbishment of the system to meet the reliability goals was prohibitive. At NASA-JSC's request, the JLab Cryogenics Group provided alternative options in 2007, including a thermo-siphon, or natural flow system. This system, eliminated the need for pumps and used one tenth of the original control valves, relief valves, and burst disks. After the thermo-siphon approach was selected, JLab provided technical assistance in the process design, mechanical design, component specification development and commissioning oversight, while the installation and commissioning operations of the system was overseen by the Jacobs Technology/ESC group at JSC. The preliminary commissioning data indicate lower shroud temperatures, 70,000 liters to cool-down and less than 90,000 liters per day consumed in steady operation. All of the performance capabilities have exceeded the design goals. This paper will outline the comparison between the original system and the predicted results of the selected design option, and the commissioning results of thermo-siphon system.

  7. Posttest analysis of MIST Test 3109AA using TRAC-PF1/MOD1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Steiner, J.L.; Siebe, D.A.; Boyack, B.E.

    This document discusses a posttest calculation and analysis of Multi-loop Integral System Test (MIST) 3109AA as the nominal test for the MIST program. It is a test of a small-break loss-of-coolant accident (SBLOCA) with a scaled 10-cm{sup 2} break in the B1 cold leg. The test exhibited the major post-SBLOCA phenomena, as expected, including depressurization to saturation, intermittent and interrupted loop flow, boiler-condenser mode cooling, refill, and postrefill cooldown. Full high-pressure injection and auxiliary feedwater were available, reactor coolant pumps were not available, and reactor-vessel vent valves and guard heaters were automatically controlled. Constant level control in the steam-generator secondariesmore » was used after steam-generator secondary refill and symmetric steam-generator pressure control was used. We performed the calculation using TRAC-PF1/MODI. Agreement between test data and the calculation was generally reasonable. All major trends and phenomena were correctly predicted. It is believed that the correct conclusions about trends and phenomena will be reached if the code is used in similar applications.« less

  8. Posttest analysis of MIST Test 3109AA using TRAC-PF1/MOD1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Steiner, J.L.; Siebe, D.A.; Boyack, B.E.

    This document discusses a posttest calculation and analysis of Multi-loop Integral System Test (MIST) 3109AA as the nominal test for the MIST program. It is a test of a small-break loss-of-coolant accident (SBLOCA) with a scaled 10-cm[sup 2] break in the B1 cold leg. The test exhibited the major post-SBLOCA phenomena, as expected, including depressurization to saturation, intermittent and interrupted loop flow, boiler-condenser mode cooling, refill, and postrefill cooldown. Full high-pressure injection and auxiliary feedwater were available, reactor coolant pumps were not available, and reactor-vessel vent valves and guard heaters were automatically controlled. Constant level control in the steam-generator secondariesmore » was used after steam-generator secondary refill and symmetric steam-generator pressure control was used. We performed the calculation using TRAC-PF1/MODI. Agreement between test data and the calculation was generally reasonable. All major trends and phenomena were correctly predicted. It is believed that the correct conclusions about trends and phenomena will be reached if the code is used in similar applications.« less

  9. Naval Air Warfare Center, Aircraft Division at Warminster Environmental Materials Program. Phase 1.

    DTIC Science & Technology

    1992-06-24

    potential for saving significant man -hours: 1) no engine cooldown would be required; 2) no dilution would be needed since the products are available...1 Watertown, MA 02172 Betz MetGhem ...................... ......................... 1 Attn: R. lezzi 4636 Somerton Rd. Trevose

  10. Heated tool for autoclaves

    NASA Technical Reports Server (NTRS)

    Serafini, T. T.; Vanucci, R. D.; Cavano, P. J.; Winters, W. E.

    1980-01-01

    Components made of composite materials are heated in autoclaves by employing electrical resistance heating blankets, thus avoiding need to heat entire autoclave volume. Method provides not only significant energy savings compared to heating entire pressure vessel but offers time savings in accelerated heat-up and cool-down cycles.

  11. Spatial mapping and statistical reproducibility of an array of 256 one-dimensional quantum wires

    NASA Astrophysics Data System (ADS)

    Al-Taie, H.; Smith, L. W.; Lesage, A. A. J.; See, P.; Griffiths, J. P.; Beere, H. E.; Jones, G. A. C.; Ritchie, D. A.; Kelly, M. J.; Smith, C. G.

    2015-08-01

    We utilize a multiplexing architecture to measure the conductance properties of an array of 256 split gates. We investigate the reproducibility of the pinch off and one-dimensional definition voltage as a function of spatial location on two different cooldowns, and after illuminating the device. The reproducibility of both these properties on the two cooldowns is high, the result of the density of the two-dimensional electron gas returning to a similar state after thermal cycling. The spatial variation of the pinch-off voltage reduces after illumination; however, the variation of the one-dimensional definition voltage increases due to an anomalous feature in the center of the array. A technique which quantifies the homogeneity of split-gate properties across the array is developed which captures the experimentally observed trends. In addition, the one-dimensional definition voltage is used to probe the density of the wafer at each split gate in the array on a micron scale using a capacitive model.

  12. Dynamic simulation of 10 kW Brayton cryocooler for HTS cable

    NASA Astrophysics Data System (ADS)

    Chang, Ho-Myung; Park, Chan Woo; Yang, Hyung Suk; Hwang, Si Dole

    2014-01-01

    Dynamic simulation of a Brayton cryocooler is presented as a partial effort of a Korean governmental project to develop 1˜3 km HTS cable systems at transmission level in Jeju Island. Thermodynamic design of a 10 kW Brayton cryocooler was completed, and a prototype construction is underway with a basis of steady-state operation. This study is the next step to investigate the transient behavior of cryocooler for two purposes. The first is to simulate and design the cool-down process after scheduled or unscheduled stoppage. The second is to predict the transient behavior following the variation of external conditions such as cryogenic load or outdoor temperature. The detailed specifications of key components, including plate-fin heat exchangers and cryogenic turbo-expanders are incorporated into a commercial software (Aspen HYSYS) to estimate the temporal change of temperature and flow rate over the cryocooler. An initial cool-down scenario and some examples on daily variation of cryocooler are presented and discussed, aiming at stable control schemes of a long cable system.

  13. Field dependent surface resistance of niobium on copper cavities

    NASA Astrophysics Data System (ADS)

    Junginger, T.

    2015-07-01

    The surface resistance RS of superconducting cavities prepared by sputter coating a niobium film on a copper substrate increases significantly stronger with the applied rf field compared to cavities of bulk material. A possible cause is that the thermal boundary resistance between the copper substrate and the niobium film induces heating of the inner cavity wall, resulting in a higher RS. Introducing helium gas in the cavity, and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by less than 120 mK when RS increases with Eacc by 100 n Ω . This is more than one order of magnitude less than what one would expect from global heating. Additionally, the effects of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for the current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered RS.

  14. Development of a Coaxial Pulse Tube Cryocooler for 77 K Cooling

    NASA Astrophysics Data System (ADS)

    Olson, J. R.; Moore, M.; Evtimov, B.; Jensen, J.; Nast, T. C.

    2006-04-01

    Lockheed Martin's Advanced Technology Center has developed a compact coaxial pulse tube cryocooler for avionics applications. The cooler was designed to deliver in excess of 1W cooling at 77K with a heat rejection temperature of 70°C, and to cool down from ambient temperature in a very short period of time. The cryocooler utilizes our MINI compressor, developed for NASA-GSFC, coupled with a newly-designed coaxial pulse tube designed to approximate the Standard Advanced Dewar Assembly (SADA II) packaging envelope. The cryocooler mass is 1.25 kg. Test data show excellent performance, with cooldown times of less than 6 minutes (coldhead only, with no additional thermal mass attached to the coldhead). Performance data will be shown for a variety of operating conditions. A discussion of low cost pulse tube cryocoolers will also be presented. This cryocooler was developed and tested with Lockheed Martin IRAD funding.

  15. Teaching Softball. Steps to Success.

    ERIC Educational Resources Information Center

    Potter, Diane L.; Brockmeyer, Gretchen A.

    This handbook was written for the instructor of softball. It is a comprehensive guide for individualizing and improving instruction. Essential instructional resources are provided, including: (1) management and safety guidelines; (2) warm-up and cool-down exercises; (3) specification of equipment needs; (4) rating charts for identifying students'…

  16. 49 CFR 193.2513 - Transfer procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Practice.” (2) Before transfer, verify that each receiving container or tank vehicle does not contain any... volume of each receiving container or tank vehicle to ensure that expansion of the incoming fluid due to... partially filled (excluding cooldown heel) container, determine any differences in temperature or specific...

  17. 49 CFR 193.2513 - Transfer procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Practice.” (2) Before transfer, verify that each receiving container or tank vehicle does not contain any... volume of each receiving container or tank vehicle to ensure that expansion of the incoming fluid due to... partially filled (excluding cooldown heel) container, determine any differences in temperature or specific...

  18. 49 CFR 193.2513 - Transfer procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Practice.” (2) Before transfer, verify that each receiving container or tank vehicle does not contain any... volume of each receiving container or tank vehicle to ensure that expansion of the incoming fluid due to... partially filled (excluding cooldown heel) container, determine any differences in temperature or specific...

  19. 49 CFR 193.2513 - Transfer procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Practice.” (2) Before transfer, verify that each receiving container or tank vehicle does not contain any... volume of each receiving container or tank vehicle to ensure that expansion of the incoming fluid due to... partially filled (excluding cooldown heel) container, determine any differences in temperature or specific...

  20. Demonstration of a magnetic refrigerator for high temperature superconducting electric power applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Murphy, R.W.; Zimm, C.B.

    1994-07-29

    This presentation/paper gives an overview of the Oak Ridge National Lab`s collaboration with private industry in developing electric power applications for magnetic refrigeraters which use high temperature superconductors. Highlighted is the lab`s general approach and technical progress towards advancing magnetic refrigeration technology in the 20-80 K range by specifically developing a prototype magnetic cryocooler with could provide 50 W cooling at 40 K. Included is magnet schematics; a listing of the basic components; load points; magnet charge and cooldown; vendor for induction alloying elements; and performance testing. The projects are in collaboration with Astronautics Corporation of America and included aremore » the proposed projects for FY 1995, key personnel, and the fiscal 1994 budgets.« less

  1. Performance, optimization, and latest development of the SRI family of rotary cryocoolers

    NASA Astrophysics Data System (ADS)

    Dovrtel, Klemen; Megušar, Franc

    2017-05-01

    In this paper the SRI family of Le-tehnika rotary cryocoolers is presented (SRI401, SRI423/SRI421 and SRI474). The Stirling coolers cooling power range starts from 0.25W to 0.75W at 77K with available temperature range from 60K to 150K and are fitted to typical dewar detector sizes and powers supply voltages. The DDCA performance optimizing procedure is presented. The procedure includes cooler steady state performance mapping and optimization and cooldown optimization. The current cryogenic performance status and reliability evaluation method and figures are presented on the existing and new units. The latest improved SRI401 demonstrated MTTF close to 25'000 hours and the test is still on going.

  2. Cyclical tests of selected space shuttle TPS metallic materials in a plasma arc tunnel Volume 1: Description of tests and program summary

    NASA Technical Reports Server (NTRS)

    Rinehart, W. A.; Land, D. W.; Painter, J. H.; Williamson, R. A.

    1972-01-01

    Work, concerned with cyclical thermal evaluation of selected space shuttle thermal protection system (TPS) metallic materials in a hypervelocity oxidizing atmosphere that approximated an actual entry environment, is presented. A total of 325 sample test hours were conducted on 21 super-alloy metallic samples at temperatures from 1800 to 2200 F (1256 to 1478 K) without any failures. The 4 x 4 in. (10.2 x 10.2 cm) samples were fabricated from five nickel base alloys and one cobalt base alloy. Eighteen of the samples were cycled 100 times each and the other three samples 50 times each in a test stream emanating from an 8 in. (20.3 cm) diam exit, Mach 4.6, conical nozzle. The test cycle consisted of a 10 min heat pulse to a controlled temperature followed by a 10 min cooldown period. The TD-NiCrAl and TD-NiAlY materials showed the least change in weight, thickness, and physical appearance even though they were subjected to the highest temperature environment.

  3. Studies Related to the Oregon State University High Temperature Test Facility: Scaling, the Validation Matrix, and Similarities to the Modular High Temperature Gas-Cooled Reactor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Richard R. Schultz; Paul D. Bayless; Richard W. Johnson

    2010-09-01

    The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5 year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) beganmore » their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant project. Because the NRC interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC). Since DOE has incorporated the HTTF as an ingredient in the NGNP thermal-fluids validation program, several important outcomes should be noted: 1. The reference prismatic reactor design, that serves as the basis for scaling the HTTF, became the modular high temperature gas-cooled reactor (MHTGR). The MHTGR has also been chosen as the reference design for all of the other NGNP thermal-fluid experiments. 2. The NGNP validation matrix is being planned using the same scaling strategy that has been implemented to design the HTTF, i.e., the hierarchical two-tiered scaling methodology developed by Zuber in 1991. Using this approach a preliminary validation matrix has been designed that integrates the HTTF experiments with the other experiments planned for the NGNP thermal-fluids verification and validation project. 3. Initial analyses showed that the inherent power capability of the OSU infrastructure, which only allowed a total operational facility power capability of 0.6 MW, is inadequate to permit steady-state operation at reasonable conditions. 4. To enable the HTTF to operate at a more representative steady-state conditions, DOE recently allocated funding via a DOE subcontract to HTTF to permit an OSU infrastructure upgrade such that 2.2 MW will become available for HTTF experiments. 5. Analyses have been performed to study the relationship between HTTF and MHTGR via the hierarchical two-tiered scaling methodology which has been used successfully in the past, e.g., APEX facility scaling to the Westinghouse AP600 plant. These analyses have focused on the relationship between key variables that will be measured in the HTTF to the counterpart variables in the MHTGR with a focus on natural circulation, using nitrogen as a working fluid, and core heat transfer. 6. Both RELAP5-3D and computational fluid dynamics (CD-Adapco’s STAR-CCM+) numerical models of the MHTGR and the HTTF have been constructed and analyses are underway to study the relationship between the reference reactor and the HTTF. The HTTF is presently being designed. It has ¼-scaling relationship to the MHTGR in both the height and the diameter. Decisions have been made to design the reactor cavity cooling system (RCCS) simulation as a boundary condition for the HTTF to ensure that (a) the boundary condition is well defined and (b) the boundary condition can be modified easily to achieve the desired heat transfer sink for HTTF experimental operations.« less

  4. Comparing the results of an analytical model of the no-vent fill process with no-vent fill test results for a 4.96 cubic meters (175 cubic feet) tank

    NASA Technical Reports Server (NTRS)

    Taylor, William J.; Chato, David J.

    1993-01-01

    The NASA Lewis Research Center (NASA/LeRC) have been investigating a no-vent fill method for refilling cryogenic storage tanks in low gravity. Analytical modeling based on analyzing the heat transfer of a droplet has successfully represented the process in 0.034 m and 0.142 cubic m commercial dewars using liquid nitrogen and hydrogen. Recently a large tank (4.96 cubic m) was tested with hydrogen. This lightweight tank is representative of spacecraft construction. This paper presents efforts to model the large tank test data. The droplet heat transfer model is found to over predict the tank pressure level when compared to the large tank data. A new model based on equilibrium thermodynamics has been formulated. This new model is compared to the published large scale tank's test results as well as some additional test runs with the same equipment. The results are shown to match the test results within the measurement uncertainty of the test data except for the initial transient wall cooldown where it is conservative (i.e., overpredicts the initial pressure spike found in this time frame).

  5. Cryogenic Two-Phase Flight Experiment: Results overview

    NASA Technical Reports Server (NTRS)

    Swanson, T.; Buchko, M.; Brennan, P.; Bello, M.; Stoyanof, M.

    1995-01-01

    This paper focuses on the flight results of the Cryogenic Two-Phase Flight Experiment (CRYOTP), which was a Hitchhiker based experiment that flew on the space shuttle Columbia in March of 1994 (STS-62). CRYOTP tested two new technologies for advanced cryogenic thermal control; the Space Heat Pipe (SHP), which was a constant conductance cryogenic heat pipe, and the Brilliant Eyes Thermal Storage Unit (BETSU), which was a cryogenic phase-change thermal storage device. These two devices were tested independently during the mission. Analysis of the flight data indicated that the SHP was unable to start in either of two attempts, for reasons related to the fluid charge, parasitic heat leaks, and cryocooler capacity. The BETSU test article was successfully operated with more than 250 hours of on-orbit testing including several cooldown cycles and 56 freeze/thaw cycles. Some degradation was observed with the five tactical cryocoolers used as thermal sinks, and one of the cryocoolers failed completely after 331 hours of operation. Post-flight analysis indicated that this problem was most likely due to failure of an electrical controller internal to the unit.

  6. High-speed furnace uses infrared radiation for controlled brazing

    NASA Technical Reports Server (NTRS)

    Eckles, P. N.

    1966-01-01

    Furnace produces controlled heat for brazing and heat treating metals over a wide range of temperatures by using a near-infrared heat source positioned at one focus of an ellipsoidal reflector mounted below a cylindrical quartz chamber. This furnace maintains a pure atmosphere, has rapid heatup and cooldown, and permits visual observation.

  7. Dynamic simulation of 10 kW Brayton cryocooler for HTS cable

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, Ho-Myung; Park, Chan Woo; Yang, Hyung Suk

    2014-01-29

    Dynamic simulation of a Brayton cryocooler is presented as a partial effort of a Korean governmental project to develop 1∼3 km HTS cable systems at transmission level in Jeju Island. Thermodynamic design of a 10 kW Brayton cryocooler was completed, and a prototype construction is underway with a basis of steady-state operation. This study is the next step to investigate the transient behavior of cryocooler for two purposes. The first is to simulate and design the cool-down process after scheduled or unscheduled stoppage. The second is to predict the transient behavior following the variation of external conditions such as cryogenicmore » load or outdoor temperature. The detailed specifications of key components, including plate-fin heat exchangers and cryogenic turbo-expanders are incorporated into a commercial software (Aspen HYSYS) to estimate the temporal change of temperature and flow rate over the cryocooler. An initial cool-down scenario and some examples on daily variation of cryocooler are presented and discussed, aiming at stable control schemes of a long cable system.« less

  8. Dynamic Simulation of a Periodic 10 K Sorption Cryocooler

    NASA Technical Reports Server (NTRS)

    Bhandari, P.; Rodriguez, J.; Bard, S.; Wade, L.

    1994-01-01

    A transient thermal simulation model has been developed to simulate the dynamic performance of a multiple-stage 10 K sorption cryocooler for spacecraft sensor cooling applications that require periodic quick-cooldown (under 2 minutes) , negligible vibration, low power consumption, and long life (5 to 10 years). The model was specifically designed to represent the Brilliant Eyes Ten-Kelvin Sorption Cryocooler Experiment (BETSCE), but it can be adapted to represent other sorption cryocooler systems as well. The model simulates the heat transfer, mass transfer, and thermodynamic processes in the cryostat and the sorbent beds for the entire refrigeration cycle, and includes the transient effects of variable hydrogen supply pressures due to expansion and overflow of hydrogen during the cooldown operation. The paper describes model limitations and simplifying assumptions, with estimates of errors induced by them, and presents comparisons of performance predictions with ground experiments. An important benefit of the model is its ability to predict performance sensitivities to variations of key design and operational parameters. The insights thus obtained are expected to lead to higher efficiencies and lower weights for future designs.

  9. Impurity Content Optimization to Maximize Q-Factors of Superconducting Resonators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martinello, Martina; Checchin, Mattia; Grassellino, Anna

    2017-05-01

    Quality factor of superconducting radio-frequency (SRF) cavities is degraded whenever magnetic flux is trapped in the cavity walls during the cooldown. In this contribution we study how the trapped flux sensitivity, defined as the trapped flux surface resistance normalized for the amount of trapped flux, depends on the mean free path. A systematic study of a variety of 1.3 GHz cavities with different surface treatments (EP, 120 C bake and different N-doping) is carried out. A bell shaped trend appears for the range of mean free path studied. Over-doped cavities fall at the maximum of this curve defining the largestmore » values of sensitivity. In addition, we have studied the trend of the BCS surface resistance contribution as a function of mean free path, showing that N-doped cavities follow close to the theoretical minimum. Adding these results together we show that the 2/6 N-doping treatment gives the highest Q-factor values at 2 K and 16 MV/m, as long as the magnetic field fully trapped during the cavity cooldown is lower than 10 mG.« less

  10. PIE on Safety-Tested Loose Particles from Irradiated Compact 4-4-2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hunn, John D.; Gerczak, Tyler J.; Morris, Robert Noel

    2016-04-01

    Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High Temperature Gas-cooled Reactors (HTGRs). This work is sponsored by the Department of Energy Office of Nuclear Energy (DOE-NE) through the Advanced Reactor Technologies (ART) Office under the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program. The AGR-1 experiment was the first in a series of TRISO fuel irradiation tests initiated in 2006. The AGR-1 TRISO particles and fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 using laboratory-scale equipment and irradiated for 3 years in themore » Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. Post-irradiation examination was performed at INL and ORNL to study how the fuel behaved during irradiation, and to test fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing and post-safety testing PIE conducted at ORNL on loose particles extracted from irradiated AGR-1 Compact 4-4-2.« less

  11. Containerless processing at high temperatures using acoustic levitation

    NASA Technical Reports Server (NTRS)

    Rey, C. A.; Merkley, D. R.; Hampton, S.; Devos, J.; Mapes-Riordan, D.; Zatarski, M.

    1991-01-01

    Advanced techniques are presented which facilitate the development of inert or reducing atmospheres in excess of 2000 K in order to improve processing of containerless capabilities at higher temperatures and to provide more contamination-free environments. Recent testing, in the laboratory and aboard the NASA KC-135 aircraft, of a high-temperature acoustic positioner demonstrated the effectiveness of a specimen motion damping system and of specimen spin control. It is found that stable positioning can be achieved under ambient and heated conditions, including the transient states of heat-up and cool-down. An incorporated high-temperature levitator was found capable of processing specimens of up to 6-mm diameter in a high-purity environment without the contaminating effects of a container at high temperatures and with relative quiescence.

  12. TRAC-PF1/MOD1 pretest predictions of MIST experiments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boyack, B.E.; Steiner, J.L.; Siebe, D.A.

    Los Alamos National Laboratory is a participant in the Integral System Test (IST) program initiated in June 1983 to provide integral system test data on specific issues and phenomena relevant to post small-break loss-of-coolant accidents (SBLOCAs) in Babcock and Wilcox plant designs. The Multi-Loop Integral System Test (MIST) facility is the largest single component in the IST program. During Fiscal Year 1986, Los Alamos performed five MIST pretest analyses. The five experiments were chosen on the basis of their potential either to approach the facility limits or to challenge the predictive capability of the TRAC-PF1/MOD1 code. Three SBLOCA tests weremore » examined which included nominal test conditions, throttled auxiliary feedwater and asymmetric steam-generator cooldown, and reduced high-pressure-injection (HPI) capacity, respectively. Also analyzed were two ''feed-and-bleed'' cooling tests with reduced HPI and delayed HPI initiation. Results of the tests showed that the MIST facility limits would not be approached in the five tests considered. Early comparisons with preliminary test data indicate that the TRAC-PF1/MOD1 code is correctly calculating the dominant phenomena occurring in the MIST facility during the tests. Posttest analyses are planned to provide a quantitative assessment of the code's ability to predict MIST transients.« less

  13. Training Patterns of Wheelchair Basketball Players in Turkey

    ERIC Educational Resources Information Center

    Tatar, Yasar

    2008-01-01

    The aim of this study was to analyze technical drills, warm-up and cool-down exercises used by wheelchair basketball players of the Turkish league in relation to training sessions. 33 male wheelchair basketball players participated in the study (mean age 26.6[plus or minus]5,95 years). All players reported that they used warm-up exercises before…

  14. Thermal conductance modeling and characterization of the SuperCDMS-SNOLAB sub-Kelvin cryogenic system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dhuley, R. C.; Hollister, M. I.; Ruschman, M. K.

    The detectors of the Super Cryogenic Dark Matter Search experiment at SNOLAB (SuperCDMS SNOLAB) will operate in a seven-layered cryostat with thermal stages between room temperature and the base temperature of 15 mK. The inner three layers of the cryostat, which are to be nominally maintained at 1 K, 250 mK, and 15 mK, will be cooled by a dilution refrigerator via conduction through long copper stems. Bolted and mechanically pressed contacts, at and cylindrical, as well as exible straps are the essential stem components that will facilitate assembly/dismantling of the cryostat. These will also allow for thermal contractions/movements duringmore » cooldown of the sub-Kelvin system. To ensure that these components and their contacts meet their design thermal conductance, prototypes were fabricated and cryogenically tested. The present paper gives an overview of the SuperCDMS SNOLAB sub-Kelvin architecture and its conductance requirements. Results from the conductance measurements tests and from sub-Kelvin thermal modeling are discussed.« less

  15. FRACTURE BEHAVIOR OF ALLOY 600, ALLOY 690, EN82H WELDS AND EN52 WELDS IN WATER

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mills, W.J., Brown, C.M. and Burke, M.G.

    2000-01-11

    The cracking resistance of Alloy 600, Alloy 690 and their welds, EN82H and EN52, was characterized by conducting J{sub IC} rising load tests in air and hydrogenated water and cooldown testing in water under constant-displacement conditions. All test materials displayed excellent toughness in air and high temperature water, but Alloy 690 and the two welds were severely embrittled in low temperature water. In 54 C water with 150 cc H{sub 2}/kg H{sub 2}O, J{sub IC} values were reduced by 70% to 95%, relative to their air counterpart. The toughness degradation was associated with a fracture mechanism transition from microvoid coalescencemore » to intergranular fracture. Comparison of the cracking response in water with that for hydrogen-precharged specimens tested in air demonstrated that susceptibility to low temperature crack propagation (LTCP) is due to hydrogen embrittlement of grain boundaries. The effects of water temperature, hydrogen content and loading rate on LTCP were studied. In addition, testing of specimens containing natural weld defects and as-machined notches was performed to determine if low temperature cracking can initiate at these features. Unlike the other materials, Alloy 600 is not susceptible to LTCP as the toughness in 54 C water remained high and a microvoid coalescence mechanism was operative in both air and water. Cooldown testing of EN82H welds under constant-displacement conditions was performed to determine if LTCP data from rising load J{sub IC}/K{sub Pmax} tests predict the onset of LTCP for other load paths. In these tests, bolt-loaded CT specimens were subjected to 288 C water for up to 1 week, cooled to 54 C and held in 54 C hydrogenated water for 1 week. This cycle was repeated up to 6 times. For two of the three welds tested, critical K{sub I} levels for LTCP under constant-displacement conditions were much higher than rising load K{sub Pmax} values. Bolt-loaded specimens from a third weld were found to exhibit LTCP at K{sub I} levels comparable to K{sub Pmax} values. Although work to date indicates that rising load tests either accurately or conservatively predict the critical conditions for LTCP under constant displacement conditions, the potential for LTCP at K{sub I} levels less than K{sub Pmax} has not been fully evaluated. Annealing at 1093 C reduces or eliminates LTCP susceptibility. The microstructure and mechanical properties for susceptible and nonsusceptible EN82H welds were characterized to identify the key material parameters responsible for LTCP in the as-welded condition. The key microstructural feature associated with LTCP appears to be fine Nb- and Ti-rich carbonitrides decorating grain boundaries. In addition, the higher yield strength for the as-fabricated weld also promotes LTCP because it increases stresses and local hydrogen concentrations ahead of a crack.« less

  16. A Complete Workout for All Runners: From the Novice to the Experienced

    ERIC Educational Resources Information Center

    Andrews-Little, Donya; Crowley, Charles; Jackson, E. Newton

    2014-01-01

    Many people grew up on the principle that a good workout consists of three basic components: warm-up, conditioning bout/activity, and cool-down. For those who participated in competitive athletics, the warm-up period seemed just as long as the activity or workout itself; but it was and remains the most important part of any workout. This article…

  17. An experimental study for a miniature Stirling refrigerator

    NASA Technical Reports Server (NTRS)

    Li, S.; Chen, G.; Huang, Z.; Zhang, F.; Cui, C.; Li, J.

    1985-01-01

    Experimental results of a miniature two-stage Stirling cryocooler are introduced. The influence of filling gas pressure and refrigeration temperature on the refrigerating capacity along with the relationship between parameters was measured. The valley pressure corresponding to the lowest refrigeration temperature and the cooldown time versus operating pressure are discussed. The coefficient of performance and thermodynamic efficiency of the cryocooler are calculated based on experimental data.

  18. Vacuum electrolysis of quartz

    DOEpatents

    King, James Claude

    1976-01-13

    The disclosure is directed to a method for processing quartz used in fabricating crystal resonators such that transient frequency change of resonators exposed to pulse irradiation is virtually eliminated. The method involves heating the crystal quartz in a hydrogen-free atmosphere while simultaneously applying an electric field in the Z-axis direction of the crystal. The electric field is maintained during the cool-down phase of the process.

  19. Passive heating following the prematch warm-up in soccer: examining the time-course of changes in muscle temperature and contractile function.

    PubMed

    Marshall, Paul W M; Cross, Rebecca; Lovell, Ric

    2015-12-01

    This study examined changes in muscle temperature, electrically evoked muscle contractile properties, and voluntary power before and after a soccer specific active warm-up and subsequent rest period. Ten amateur soccer players performed two experimental sessions that involved performance of a modified FIFA 11+ soccer specific warm-up, followed by a 12.5-min rest period where participants were required to wear either normal clothing or a passive electrical heating garment was applied to the upper thigh muscles. Assessments around the warm-up and cool-down included measures of maximal torque, rate of torque development, muscle temperature (Tm), and electrically evoked measures of quadriceps contractile function. Tm was increased after the warm-up by 3.2 ± 0.7°C (P < 0.001). Voluntary and evoked rates of torque development increased after the warm-up between 20% and 30% (P < 0.05), despite declines in both maximal voluntary torque and voluntary activation (P < 0.05). Application of a passive heating garment in the cool-down period after the warm-up did not effect variables measured. While Tm was reduced by 1.4 ± 0.4°C after the rest period (P < 0.001), this value was still higher than pre warm-up levels. Voluntary and evoked rate of torque development remained elevated from pre warm-up levels at the end of the cool-down (P < 0.05). The soccer specific warm-up elevated muscle temperature by 3.2°C and was associated with concomitant increases of between 20% and 30% in voluntary rate of torque development, which seems explained by elevations in rate-dependent measures of intrinsic muscle contractile function. Application of a passive heating garment did not attenuate declines in muscle temperature during a 12.5-min rest period. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  20. SpaceX Dragon Air Circulation System

    NASA Technical Reports Server (NTRS)

    Hernandez, Brenda; Piatrovich, Siarhei; Prina, Mauro

    2011-01-01

    The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

  1. Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors.

    PubMed

    Chiuchiolo, Antonella; Palmieri, Luca; Consales, Marco; Giordano, Michele; Borriello, Anna; Bajas, Hugues; Galtarossa, Andrea; Bajko, Marta; Cusano, Andrea

    2015-10-01

    This contribution presents distributed and multipoint fiber-optic monitoring of cryogenic temperatures along a superconducting power transmission line down to 30 K and over 20 m distance. Multipoint measurements were conducted using fiber Bragg gratings sensors coated with two different functional overlays (epoxy and poly methyl methacrylate (PMMA)) demonstrating cryogenic operation in the range 300-4.2 K. Distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimide). The integrated system has been placed along the 20 m long cryostat of a superconducting power transmission line, which is currently being tested at the European Organization for Nuclear Research (CERN). Cool-down events from 300-30 K have been successfully measured in space and time, confirming the viability of these approaches to the monitoring of cryogenic temperatures along a superconducting transmission line.

  2. Performance of a 10-kJ SMES model cooled by liquid hydrogen thermo-siphon flow for ASPCS study

    NASA Astrophysics Data System (ADS)

    Makida, Y.; Shintomi, T.; Hamajima, T.; Ota, N.; Katsura, M.; Ando, K.; Takao, T.; Tsuda, M.; Miyagi, D.; Tsujigami, H.; Fujikawa, S.; Hirose, J.; Iwaki, K.; Komagome, T.

    2015-12-01

    We propose a new electrical power storage and stabilization system, called an Advanced Superconducting Power Conditioning System (ASPCS), which consists of superconducting magnetic energy storage (SMES) and hydrogen energy storage, converged on a liquid hydrogen station for fuel cell vehicles. A small 10- kJ SMES system, in which a BSCCO coil cooled by liquid hydrogen was installed, was developed to create an experimental model of an ASPCS. The SMES coil is conductively cooled by liquid hydrogen flow through a thermo-siphon line under a liquid hydrogen buffer tank. After fabrication of the system, cooldown tests were carried out using liquid hydrogen. The SMES coil was successfully charged up to a nominal current of 200 A. An eddy current loss, which was mainly induced in pure aluminum plates pasted onto each pancake coils for conduction cooling, was also measured.

  3. Test and evaluation of Apollo 14 composite casting demonstration specimens 6, 9, and 12, phase 1

    NASA Technical Reports Server (NTRS)

    Reger, J. L.

    1971-01-01

    Flight and control specimens 6, 9, and 12 from the Apollo 14 composite casting demonstration were evaluated with respect to the degree of dispersion achieved for mixtures of immiscible materials under one-gravity and low gravity environments. The flight and control capsules 6, 9, and 12 contained paraffin and sodium acetate; paraffin, sodium acetate and argon; and paraffin, sodium acetate and 100 micrometer diameter tungsten microspheres, respectively. The evaluation and documentation utilized photographic and microstructure examinations, density measurements, and droplet size and distribution determinations. In addition, theoretical analyses were performed in order to aid in the understanding of the fluid behavior of the specimens during processing and subsequent solidification. A comparison of evaluated data with the theoretical analyses reveals that although the immiscible materials were uniquely dispersed in a low gravity environment, nonuniform dispersions were obtained primarily due to insufficient initial mixing and an essentially unidirectional thermal gradient during cooldown.

  4. Cryogen free cooling of ASTRO-H SXS Helium Dewar from 300 K to 4 K

    NASA Astrophysics Data System (ADS)

    Kanao, Ken'ichi; Yoshida, Seiji; Miyaoka, Mikio; Tsunematsu, Shoji; Otsuka, Kiyomi; Hoshika, Shunji; Narasaki, Katsuhiro; Mitsuda, Kazuhisa; Yamasaki, Noriko; Takei, Yoh; Fujimoto, Ryuji; Sato, Yoichi; Okamoto, Atsushi; Noda, Hirofumi; DiPirro, Michel J.; Shirron, Peter J.

    2017-12-01

    Soft X-ray Spectrometer instrument (SXS) is one of the primary scientific instruments of ASTRO-H. SXS has a cold detector that is cooled to 50 mK by using a multi-stage Adiabatic Demagnetization Refrigerator (ADR). SXS Dewar containing ADR provides 1.3 K heat sink by using liquid helium in nominal operation. After liquid helium is dried up, 4 K heat sink is provided by using mechanical coolers. Both nominal operation and cryogen free operation were successfully demonstrated. This paper describes the test result of cryogen free operation and cool-down performance from room temperature by using only mechanical coolers without liquid helium. The coolers on the Dewar cooled down cold mass from around 300 K to 4 K with 260 W electric power in 40 days. Cold mass is 35 kg in 4 K area including the helium tank, ADR and detector assembly.

  5. [Cumulative effect of Coriolis acceleration on coronary hemodynamics].

    PubMed

    Lapaev, E V; Bednenko, V S

    1985-01-01

    Time-course variations in coronary circulation and cardiac output were measured in 29 healthy test subjects who performed tests with a continuous cumulation of Coriolis accelerations and in 12 healthy test subjects who were exposed to Coriolis accelerations combined with acute hypoxia. Adaptive changes in coronary circulation were seen. It is recommended to monitor coronary circulation during vestibulometric tests as part of medical expertise of the flying personnel.

  6. Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael

    The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, whichmore » are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.« less

  7. Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

    DOE PAGES

    Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael; ...

    2016-11-22

    The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, whichmore » are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.« less

  8. Commissioning the cryogenic system of the first LHC sector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Millet, F.; Claudet, S.; Ferlin, G.

    2007-12-01

    The LHC machine, composed of eight sectors with superconducting magnets and accelerating cavities, requires a complex cryogenic system providing high cooling capacities (18 kW equivalent at 4.5 K and 2.4 W at 1.8 K per sector produced in large cold boxes and distributed via 3.3-km cryogenic transfer lines). After individual reception tests of the cryogenic subsystems (cryogen storages, refrigerators, cryogenic transfer lines and distribution boxes) performed since 2000, the commissioning of the cryogenic system of the first LHC sector has been under way since November 2006. After a brief introduction to the LHC cryogenic system and its specificities, the commissioningmore » is reported detailing the preparation phase (pressure and leak tests, circuit conditioning and flushing), the cool-down sequences including the handling of cryogenic fluids, the magnet powering phase and finally the warm-up. Preliminary conclusions on the commissioning of the first LHC sector will be drawn with the review of the critical points already solved or still pending. The last part of the paper reports on the first operational experience of the LHC cryogenic system in the perspective of the commissioning of the remaining LHC sectors and the beam injection test.« less

  9. Evaluation of a Highly Anticlastic Panel with Tow Overlaps

    NASA Technical Reports Server (NTRS)

    Wu, K. Chauncey; Gurdal, Zafer

    2007-01-01

    A rectangular, variable-stiffness panel with tow overlaps was manufactured using an advanced tow placement machine. The cured panel had large anticlastic imperfections, with measured amplitudes of over two times the average panel thickness. These imperfections were not due to the overall steered-fiber layup or the tow overlaps, but instead resulted from local asymmetries in the laminate that were caused by a manufacturing oversight. In the nominal panel layup, fiber angles vary linearly from 60 degrees on the panel axial centerline to 30 degrees on the parallel edges. A geometrically nonlinear analysis was performed with a -280 degree Fahrenheit thermal load to simulate the postcure cooldown to room temperature. The predicted geometric imperfections correlated well with the measured panel shape. Unique structural test fixtures were then developed which greatly reduced these imperfections, but they also caused prestresses in the panel. Surface imperfections measured after the panel was installed in the test fixtures were used with nonlinear finite element analyses to predict these fixturing-induced prestresses. These prestresses were also included in structural analyses of panel end compression to failure, and the analytical results compared well with test data when both geometric and material nonlinearities were included.

  10. Fuel Reduction for the Mobility Air Forces

    DTIC Science & Technology

    2015-01-01

    turbofan engines is sufficient to move an aircraft at taxi speed on the ground. Commercial carriers regularly use one engine when taxiing.12 For...Similarly, some, but by no means all, of the ground operations fuel use can be eliminated: Turbofan engines require a warm- up and cool-down period...25 Pratt & Whitney, Operating Instructions for the PW4000 Series Commercial Turbofan Engines, online, undated. THEORETICAL  LIMIT  OF

  11. Using the Non-Intrusive Load Monitor for Shipboard Supervisory Control

    DTIC Science & Technology

    2007-06-01

    consists of a NEMA certified enclosure with voltage transducers and a DC power supply inside, appropriately sized current transducers, and a...command to the UEC. UEC starts a 300-second (5 minutes). “GTM __ TRANSITIONING TO COOLDOWN” is displayed on the AMLCD. “ NORM STOP/COOLDOWN...MMA-010, 01 Jul 1992. 80 Appendix A NILM Parts List Nomenclature Manufacturer Part Number Quantity NEMA Enclosure Rittal Corporation

  12. Pre-cooling of ton-scale particle detectors in low radioactivity environments

    NASA Astrophysics Data System (ADS)

    Cappelli, L.; Pagliarone, C. E.; Bucci, C.; D’Aguanno, D.; Erme, G.; Gorla, P.; Kartal, S.; Marignetti, F.

    2018-03-01

    Low radioactivity sites are mandatory to perform searches for rare processes that cannot be studied with particle accelerators and requires low environmental backgrounds. Neutrino-less double β decay or Dark Matter searches must be performed in underground low radioactivity observatories. Large detectors are needed to increase the acceptances and proper cryogenic systems to run dedicated detectors. To reach the working temperatures, refrigerators as Pulse Tubes, Dilution Units are used inside complex cryostats. CUORE, Cryogenic Underground Observatory for Rare Events, is an experiment located at LNGS under the Gran Sasso mountain. So far, it’s the coldest cubic meter and the largest cold mass ever realized. Its 998 TeO2 bolometers need to be kept at temperatures T< 10 mK. Using only Pulse Tubes, CUORE needs several weeks to reach the baseline T. Then a Fast Cooling System has been designed and constructed for a faster precooling of the whole CUORE cold volume. The Fast Cooling System (FCS) consists of a cryostat with heat exchangers that use 3 Gifford-McMahon refrigerators, a 4He compressor, a filtering module and several sensors that allow to monitor and control the system during CUORE cooldown. The present work describes the FCS and summarizes its performances during the first full CUORE cooldown.

  13. Moisture-Induced Delayed Alumina Scale Spallation on a Ni(Pt)Al Coating

    NASA Technical Reports Server (NTRS)

    Smialek, James L.

    2009-01-01

    Delayed interfacial scale failure takes place after cooling for samples of a Ni(Pt)Al-coated CMSX4 single crystal superalloy, cycled at 1150 C for up to 2000 hr. One sample exhibited premature coating grain boundary wrinkling, alumina scale spallation to bare metal, and a final weight loss of 3.3 mg/cm2 . Spallation under ambient conditions was monitored with time after cooldown and was found to continue for 24 hr. This produced up to 0.05 mg/cm2 additional loss for each hold, accumulating 0.7 mg/cm 2 (20 percent of the total) over the course of the test. After test termination, water immersion produced an additional 0.15 mg/cm2 loss. (A duplicate sample produced much less wrinkling and time dependent spalling, maintaining a net weight gain.) The results are consistent with the general phenomena of moisture-induced delayed spallation (MIDS) of mature, distressed alumina scales formed on oxidation resistant M-Al alloys. Relative ambient humidity is discussed as the factor controlling adsorbed moisture, reaction with the substrate, and hydrogen effects on interface strength.

  14. Analysis and test results for a molten salt thermal energy storage system

    NASA Astrophysics Data System (ADS)

    Sterrett, R. H.; Scott, O. L.

    A system has been developed to provide low cost thermal energy storage using molten salt. It consists of a hot tank to store the 565 C (1050 F) salt and a cold tank to store the 289 C (550 F) salt. The hot tank uses internal insulation protected by a liner to enable the use of a carbon steel shell for structural support. Due to the lower salt temperature, the cold tank can be a carbon steel shell with external insulation. This paper describes an analytical method used to predict the thermal performance of such systems and presents experimental data from a Subsystem Research Experiment (SRE) conducted by Martin Marietta Aerospace, Solar Energy Systems under contract from Sandia National Laboratories, Livermore, CA. The results from three of the SRE test cases are compared with the STS model results. These are (1) steady state operation, (2) concurrent charging and discharging, and (3) transient cooldown. The temperature differences between the analytical and experimental results were less than 10%. The internally insulated hot tank performed well.

  15. The Effects of Eight-Month Physical Activity Intervention on Vigilance Performance in Adult Obese Population.

    PubMed

    Monleón, Cristina; Ballester, Rafael; Sanchis, Carlos; Llorens, Francesc; Martín, Marta; Pablos, Ana

    2015-01-01

    We aim to analyze the effects of an 8-month physical activity intervention on cardiorespiratory fitness, body mass index (BMI), and vigilance performance in an adult obese population. We conducted an 8-month physical activity intervention based on dance and rhythmic activities. The weekly frequency was 2 sessions of 1 hr per day. Training sessions were divided into 3 phases: a 10-min warm-up, 40 min of dance and rhythmic activities, and 10 min to cool-down. To assess cardiorespiratory fitness, participants performed a modified version of the 6-min walk test from the Senior Fitness Test battery (Larsson & Mattsson, 2001; Rikli & Jones, 1999). Vigilance performance was measured by means of the psychomotor vigilance task (PVT). Two measurements were performed immediately before and after the intervention. The results revealed that participants improved their cardiorespiratory fitness, BMI, and vigilance performance after the intervention. All in all, findings contribute new empirical evidence to the field that investigates the benefits of physical activity intervention on cognitive processes in obese population.

  16. Optical Fiber Distributed Sensing Structural Health Monitoring (SHM) Strain Measurements Taken During Cryotank Y-Joint Test Article Load Cycling at Liquid Helium Temperatures

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, Winfred S.

    2007-01-01

    This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

  17. Overview of the hydraulic characteristics of the ITER Central Solenoid Model Coil conductors after 15 years of test campaigns

    NASA Astrophysics Data System (ADS)

    Brighenti, A.; Bonifetto, R.; Isono, T.; Kawano, K.; Russo, G.; Savoldi, L.; Zanino, R.

    2017-12-01

    The ITER Central Solenoid Model Coil (CSMC) is a superconducting magnet, layer-wound two-in-hand using Nb3Sn cable-in-conduit conductors (CICCs) with the central channel typical of ITER magnets, cooled with supercritical He (SHe) at ∼4.5 K and 0.5 MPa, operating for approximately 15 years at the National Institutes for Quantum and Radiological Science and Technology in Naka, Japan. The aim of this work is to give an overview of the issues related to the hydraulic performance of the three different CICCs used in the CSMC based on the extensive experimental database put together during the past 15 years. The measured hydraulic characteristics are compared for the different test campaigns and compared also to those coming from the tests of short conductor samples when available. It is shown that the hydraulic performance of the CSMC conductors did not change significantly in the sequence of test campaigns with more than 50 cycles up to 46 kA and 8 cooldown/warmup cycles from 300 K to 4.5 K. The capability of the correlations typically used to predict the friction factor of the SHe for the design and analysis of ITER-like CICCs is also shown.

  18. 3D-FE Modeling of 316 SS under Strain-Controlled Fatigue Loading and CFD Simulation of PWR Surge Line

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohanty, Subhasish; Barua, Bipul; Listwan, Joseph

    In financial year 2017, we are focusing on developing a mechanistic fatigue model of surge line pipes for pressurized water reactors (PWRs). To that end, we plan to perform the following tasks: (1) conduct stress- and strain-controlled fatigue testing of surge-line base metal such as 316 stainless steel (SS) under constant, variable, and random fatigue loading, (2) develop cyclic plasticity material models of 316 SS, (3) develop one-dimensional (1D) analytical or closed-form model to validate the material models and to understand the mechanics associated with 316 SS cyclic hardening and/or softening, (4) develop three-dimensional (3D) finite element (FE) models withmore » implementation of evolutionary cyclic plasticity, and (5) develop computational fluid dynamics (CFD) model for thermal stratification, thermal-mechanical stress, and fatigue of example reactor components, such as a PWR surge line under plant heat-up, cool-down, and normal operation with/without grid-load-following. This semi-annual progress report presents the work completed on the above tasks for a 316 SS laboratory-scale specimen subjected to strain-controlled cyclic loading with constant, variable, and random amplitude. This is the first time that the accurate 3D-FE modeling of the specimen for its entire fatigue life, including the hardening and softening behavior, has been achieved. We anticipate that this work will pave the way for the development of a fully mechanistic-computer model that can be used for fatigue evaluation of safety-critical metallic components, which are traditionally evaluated by heavy reliance on time-consuming and costly test-based approaches. This basic research will not only help the nuclear reactor industry for fatigue evaluation of reactor components in a cost effective and less time-consuming way, but will also help other safety-related industries, such as aerospace, which is heavily dependent on test-based approaches, where a single full-scale fatigue test can cost millions of dollars and require years of effort to conduct. Toward our goal of demonstration of fully mechanistic fatigue evaluation of reactor components, we also started work on developing a component-level computer model of reactor components, such as 316 SS surge line pipe. This requires developing a thermal-mechanical stress analysis model of the reactor surge line, which, in turn, requires time-dependent temperature and stratification information along the boundary of the pipe. Toward that goal, CFD models of surge lines are being developed. In this report, we also present some preliminary results showing the temperature conditions along the surge line wall under reactor heat-up, cool-down, and steady-state power operation.« less

  19. Posttest analysis of MIST Test 320201 using TRAC-PF1/MOD1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Siebe, D.A.; Steiner, J.L.; Boyack, B.E.

    A posttest calculation and analysis of Multi-Loop Integral System Test 320201, a small-break loss-of-coolant accident (SBLOCA) test with a scaled 50-cm{sup 2} cold-leg pump discharge leak, has been completed and is reported herein. It was one in a series of tests, with leak size varied parametrically. Scaled leak sizes included 5, 10, (the nominal, Test 3109AA), and 50 cm{sub 2}. The test exhibited the major post-SBLOCA phenomena, as expected, including depressurization to saturation, interruption of loop flow, boiler-condenser mode cooling, refill, and postrefill cooldown. Full high-pressure injection and auxiliary feedwater were available, reactor coolant pumps were not available, and reactor-vesselmore » vent valves and guard heaters were automatically controlled. Constant level control in the steam-generator (SG) secondaries was used after SG-secondary refill; and symmetric SG pressure control was also used. The sequence of events seen in this test was similar to the sequence of events for much of the nominal test except that events occurred in a shorter time frame as the system inventory was reduced and the system depressurized at a faster rate. The calculation was performed using TRAC-PFL/MOD 1. Agreement between test data and the calculation was generally reasonable. All major trends and phenomena were correctly predicted. We believe that the correct conclusions about trends and phenomena will be reached if the code is used in similar applications.« less

  20. Posttest analysis of MIST Test 320201 using TRAC-PF1/MOD1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Siebe, D.A.; Steiner, J.L.; Boyack, B.E.

    A posttest calculation and analysis of Multi-Loop Integral System Test 320201, a small-break loss-of-coolant accident (SBLOCA) test with a scaled 50-cm[sup 2] cold-leg pump discharge leak, has been completed and is reported herein. It was one in a series of tests, with leak size varied parametrically. Scaled leak sizes included 5, 10, (the nominal, Test 3109AA), and 50 cm[sub 2]. The test exhibited the major post-SBLOCA phenomena, as expected, including depressurization to saturation, interruption of loop flow, boiler-condenser mode cooling, refill, and postrefill cooldown. Full high-pressure injection and auxiliary feedwater were available, reactor coolant pumps were not available, and reactor-vesselmore » vent valves and guard heaters were automatically controlled. Constant level control in the steam-generator (SG) secondaries was used after SG-secondary refill; and symmetric SG pressure control was also used. The sequence of events seen in this test was similar to the sequence of events for much of the nominal test except that events occurred in a shorter time frame as the system inventory was reduced and the system depressurized at a faster rate. The calculation was performed using TRAC-PFL/MOD 1. Agreement between test data and the calculation was generally reasonable. All major trends and phenomena were correctly predicted. We believe that the correct conclusions about trends and phenomena will be reached if the code is used in similar applications.« less

  1. Arc jet testing of a Dynasil dome

    NASA Astrophysics Data System (ADS)

    Burrell, Jack O.; Strobel, Forrest A.

    1999-07-01

    Arc jet testing of the Hera modified ballistic reentry vehicle - 1E (MBRV-1E) nosetip was conducted in June of 1998. The tests were conducted in the Air Force's Arnold Engineering Development Center HEAT-H1 arc plasma test facility in Tullahoma, Tennessee. The MBRV-1 vehicle is a separating short- to medium-range target. The MBRV-1E nosetip incorporates a custom designed quartz dome that is integrated into the nosetip stagnation region. The dome was bonded to the baseline nosetip material, a well characterized carbon-carbon composite material, using a silica based ceramic bond materials. The objectives of the test were to demonstrate the thermal performance and structural integrity of the nosetip design by exposing tip to arc plasma-heated flow simulating the reentry flight environment. Pre-test analysis of the Dynasil dome performed using finite element analysis predicted the dome would survive the test conditions with no failures. Post-test inspection of the dome revealed a hard, opaque coating on the outer surface of the dome. Once removed, the dome was shown to have numerous surface cracks near the stagnation region. In addition to the surface cracks, significant pitting on the surface was observed through both an optical microscope and a scanning electron microscope. Post-test analyses were performed to determine the cause of these surface cracks. It was concluded that the cracks occurred during cooldown, and were a result of significant strength degradation which was caused by the surface pitting.

  2. Using SA508/533 for the HTGR Vessel Material

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Larry Demick

    2012-06-01

    This paper examines the influence of High Temperature Gas-cooled Reactor (HTGR) module power rating and normal operating temperatures on the use of SA508/533 material for the HTGR vessel system with emphasis on the calculated times at elevated temperatures approaching or exceeding ASME Code Service Limits (Levels B&C) to which the reactor pressure vessel could be exposed during postulated pressurized and depressurized conduction cooldown events over its design lifetime.

  3. Musculoskeletal Injury: Risks Prevention and First Aid,

    DTIC Science & Technology

    1986-09-08

    games and sports like tennis and soccer. Management of risks will be discussed, but because of our imprecise knowledge of risk factors only general...College of Sports Medicine Position Statement on Proper and Improper Weight Loss Programs). 3 Female sex has also been implicated as a risk factor for...particular sport of interest should be consulted for specific stretching routines. The cool-down, like the warm-up, is thought to be beneficial in preventing

  4. Evaluation of Heating Methods for Thermal Structural Testing of Large Structures

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Sikora, Joseph G.; Caldwell, Darrell L., Jr.

    1998-01-01

    An experimental study was conducted to evaluate different heating methods for thermal structural testing of large scale structures at temperatures up to 350 F as part of the High Speed Research program. The heating techniques evaluated included: radiative/convective, forced convective, and conductive. The radiative/convective heaters included finned strip heaters, and clear and frosted quartz lamps. The forced convective heating was accomplished by closed loop circulation of heated air. The conductive heater consisted of heating blankets. The tests were conducted on an 1/8 inch thick stainless steel plate in a custom-built oven. The criteria used for comparing the different heating methods included test specimen temperature uniformity, heater response time, and consumed power. The parameters investigated included air circulation in the oven, reflectance of oven walls, and the orientation of the test specimen and heaters (vertical and horizontal). It was found that reflectance of oven walls was not an important parameter. Air circulation was necessary to obtain uniform temperatures only for the vertically oriented specimen. Heating blankets provided unacceptably high temperature non-uniformities. Quartz lamps with internal air circulation had the lowest power consumption levels. Using frosted quartz lamps with closed loop circulation of cool air, and closed loop circulation of heated air provided the fastest response time.

  5. Performance evaluation approach for the supercritical helium cold circulators of ITER

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vaghela, H.; Sarkar, B.; Bhattacharya, R.

    2014-01-29

    The ITER project design foresees Supercritical Helium (SHe) forced flow cooling for the main cryogenic components, namely, the superconducting (SC) magnets and cryopumps (CP). Therefore, cold circulators have been selected to provide the required SHe mass flow rate to cope with specific operating conditions and technical requirements. Considering the availability impacts of such machines, it has been decided to perform evaluation tests of the cold circulators at operating conditions prior to the series production in order to minimize the project technical risks. A proposal has been conceptualized, evaluated and simulated to perform representative tests of the full scale SHe coldmore » circulators. The objectives of the performance tests include the validation of normal operating condition, transient and off-design operating modes as well as the efficiency measurement. A suitable process and instrumentation diagram of the test valve box (TVB) has been developed to implement the tests at the required thermodynamic conditions. The conceptual engineering design of the TVB has been developed along with the required thermal analysis for the normal operating conditions to support the performance evaluation of the SHe cold circulator.« less

  6. Vapor generator steam drum spray head

    DOEpatents

    Fasnacht, Jr., Floyd A.

    1978-07-18

    A typical embodiment of the invention provides a combination feedwater and "cooldown" water spray head that is centrally disposed in the lower portion of a nuclear power plant steam drum. This structure not only discharges the feedwater in the hottest part of the steam drum, but also increases the time required for the feedwater to reach the steam drum shell, thereby further increasing the feedwater temperature before it contacts the shell surface, thus reducing thermal shock to the steam drum structure.

  7. Avionics Integrity Issues Presented during NAECON (National Aerospace and Electronics Convention) 1984.

    DTIC Science & Technology

    1984-12-01

    PLASTIC ABOVE BOOC 2. PTH COPPER SHOULD BE ABOVE 62 ELONGATION, 5OKPSI 3. PTH LIFE IS INCREAS-D WITH LARGER PTH AND POLYIMIDE PWB’S 4. SOLDER JOINT DEFO M...34XTION IS PREDOMINANTLY PLASTIC , THEREFORE HIGH SOLDER DUCTILITY IS IMPORTANT - AVOID SOLDER CONTAMINANTS - AVOID HOT STORAGE OR SLOW COOLDOWN SUMMARY...UTILIZATION OF STEP-STRESS TECHNIQUE o MANAGEMENT CONSIDERATIONS * PLASTIC PARTS AFAILURE ANALYSIS/DPA 0SHELF TIME VS RESCREEN *USE OF ACCELERATED

  8. Thermal Analysis of the ILC Superconductin Quadrupole

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ross, Ian; /Rose-Hulman Inst., Terre Haute /SLAC

    2006-09-13

    Critical to a particle accelerator's functioning, superconducting magnets serve to focus and aim the particle beam. The Stanford Linear Accelerator Center (SLAC) has received a prototype superconducting quadrupole designed and built by the Centro de Investigaciones Energ{acute e}ticas, Medioambientales y Tecnol{acute o}gicas (CIEMAT) to be evaluated for the International Linear Collider (ILC) project. To ensure proper functioning of the magnet, the device must be maintained at cryogenic temperatures by use of a cooling system containing liquid nitrogen and liquid helium. The cool down period of a low temperature cryostat is critical to the success of an experiment, especially a prototypemore » setup such as this one. The magnet and the dewar each contain unique heat leaks and material properties. These differences can lead to tremendous thermal stresses. The system was analyzed mathematically, leading to ideal liquid helium and liquid nitrogen flow rates during the magnet's cool-down to 4.2 K, along with a reasonable estimate of how long this cool-down will take. With a flow rate of ten gaseous liters of liquid nitrogen per minute, the nitrogen shield will take approximately five hours to cool down to 77 K. With a gaseous helium flow rate of sixty liters per minute, the magnet will take at least nineteen hours to cool down to a temperature of 4.2 K.« less

  9. SCALE UP OF CERAMIC WASTE FORMS FOR THE EBR-II SPENT FUEL TREATMENT PROCESS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matthew C. Morrison; Kenneth J. Bateman; Michael F. Simpson

    2010-11-01

    ABSTRACT SCALE UP OF CERAMIC WASTE FORMS FOR THE EBR-II SPENT FUEL TREATMENT PROCESS Matthew C. Morrison, Kenneth J. Bateman, Michael F. Simpson Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 The ceramic waste process is the intended method for disposing of waste salt electrolyte, which contains fission products from the fuel-processing electrorefiners (ER) at the INL. When mixed and processed with other materials, the waste salt can be stored in a durable ceramic waste form (CWF). The development of the CWF has recently progressed from small-scale testing and characterization to full-scale implementation and experimentation using surrogate materialsmore » in lieu of the ER electrolyte. Two full-scale (378 kg and 383 kg) CWF test runs have been successfully completed with final densities of 2.2 g/cm3 and 2.1 g/cm3, respectively. The purpose of the first CWF was to establish material preparation parameters. The emphasis of the second pre-qualification test run was to evaluate a preliminary multi-section CWF container design. Other considerations were to finalize material preparation parameters, measure the material height as it consolidates in the furnace, and identify when cracking occurs during the CWF cooldown process.« less

  10. Fracture mechanics analysis for various fiber/matrix interface loadings

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1991-01-01

    Fiber/matrix (F/M) cracking was analyzed to provide better understanding and guidance in developing F/M interface fracture toughness tests. Two configurations, corresponding to F/M cracking at a broken fiber and at the free edge, were investigated. The effects of mechanical loading, thermal cooldown, and friction were investigated. Each configuration was analyzed for two loadings: longitudinal and normal to the fiber. A nonlinear finite element analysis was performed to model friction and slip at the F/M interface. A new procedure for fitting a square-root singularity to calculated stresses was developed to determine stress intensity factors (K sub I and K sub II) for a bimaterial interface crack. For the case of F/M cracking at a broken fiber with longitudinal loading, crack tip conditions were strongly influenced by interface friction. As a result, an F/M interface toughness test based on this case was not recommended because nonlinear data analysis methods would be required. For the free edge crack configuration, both mechanical and thermal loading caused crack opening, thereby avoiding frictional effects. A F/M interface toughness test based on this configuration would provide data for K(sub I)/K(sub II) ratios of about 0.7 and 1.6 for fiber and radial normal loading, respectively. However, thermal effects must be accounted for in the data analysis.

  11. Fracture mechanics analysis for various fiber/matrix interface loadings

    NASA Technical Reports Server (NTRS)

    Naik, Rajiv A.; Crews, John H., Jr.

    1992-01-01

    Fiber/matrix (F/M) cracking was analyzed to provide better understanding and guidance in developing F/M interface fracture toughness tests. Two configurations, corresponding to F/M cracking at a broken fiber and at the free edge, were investigated. The effects of mechanical loading, thermal cooldown, and friction were investigated. Each configuration was analyzed for two loadings: longitudinal and normal to the fiber. A nonlinear finite element analysis was performed to model friction and slip at the F/M interface. A new procedure for fitting a square-root singularity to calculated stresses was developed to determine stress intensity factors (K sub I and K sub II) for a bimaterial interface crack. For the case of F/M cracking at a broken fiber with longitudinal loading, crack tip conditions were strongly influenced by interface friction. As a result, an F/M interface toughness test based on this case was not recommended because nonlinear data analysis methods would be required. For the free edge crack configuration, both mechanical and thermal loading caused crack opening, theory avoiding fractional effects. A F/M interface toughness test based on this configuration would provide data for K(sub I/K(sub II) ratios of about 0.7 and 1.6 for fiber and radial normal loading, respectively. However, thermal effects must be accounted for in the data analysis.

  12. Fracture mechanics analysis for various fiber/matrix interface loadings

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1991-01-01

    Fiber/matrix (F/M) cracking was analyzed to provide better understanding and guidance in developing F/M interface fracture toughness tests. Two configurations, corresponding to F/M cracking at a broken fiber and at the free edge, were investigated. The effects of mechanical loading, thermal cooldown, and friction were investigated. Each configuration was analyzed for two loadings: longitudinal and normal to the fiber. A nonlinear finite element analysis was performed to model friction and slip at the F/M interface. A new procedure for fitting a square-root singularity to calculated stresses was developed to determine stress intensity factors (K sub I and K sub II) for a bimaterial interface crack. For the case of F/M cracking at a broken fiber with longitudinal loading, crack tip conditions were strongly influenced by interface friction. As a result, an F/M interface toughness test based on this case was not recommended because nonlinear data analysis methods would be required. For the free edge crack configuration, both mechanical and thermal loading caused crack opening, thereby avoiding frictional effects. An F/M interface toughness test based on this configuration would provide data for K(sub I)/K(sub II) ratios of about 0.7 and 1.6 for fiber and radial normal loading, respectively. However, thermal effects must be accounted for in the data analysis.

  13. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection and enumeration system. (a) Identification. An immunomagnetic circulating cancer cell selection and enumeration...

  14. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection and enumeration system. (a) Identification. An immunomagnetic circulating cancer cell selection and enumeration...

  15. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection and enumeration system. (a) Identification. An immunomagnetic circulating cancer cell selection and enumeration...

  16. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection and enumeration system. (a) Identification. An immunomagnetic circulating cancer cell selection and enumeration...

  17. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection and enumeration system. (a) Identification. An immunomagnetic circulating cancer cell selection and enumeration...

  18. MEASUREMENT OF RF LOSSES DUE TO TRAPPED FLUX IN A LARGE-GRAIN NIOBIUM CAVITY

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gianluigi Ciovati; Alex Gurevich

    Trapped magnetic field in superconducting niobium is a well known cause of radio-frequency (RF) residual losses. In this contribution, we present the results of RF tests on a single-cell cavity made of high-purity large grain niobium before and after allowing a fraction of the Earth’s magnetic field to be trapped in the cavity during the cooldown below the critical temperature Tc. This experiment has been done on the cavity before and after a low temperature baking. Temperature mapping allowed us to determine the location of hot-spots with high losses and to measure their field dependence. The results show not onlymore » an increase of the low-field residual resistance, but also a larger increase of the surface resistance for intermediate RF field (higher "medium field Qslope"), which depends on the amount of the trapped flux. These additional field-dependent losses can be described as losses of pinned vortices oscillating under the applied RF magnetic field.« less

  19. Learning Circulant Sensing Kernels

    DTIC Science & Technology

    2014-03-01

    Furthermore, we test learning the circulant sensing matrix/operator and the nonparametric dictionary altogether and obtain even better performance. We...scale. Furthermore, we test learning the circulant sensing matrix/operator and the nonparametric dictionary altogether and obtain even better performance...matrices, Tropp et al.[28] de - scribes a random filter for acquiring a signal x̄; Haupt et al.[12] describes a channel estimation problem to identify a

  20. Thermal Performance of LANDSAT-7 ETM+ Instruments During First Year in Flight

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.

    2000-01-01

    Landsat-7 was successfully launched into orbit on April 15, 1999. After devoting three months to the t bakeout and cool-down of the radiative cooler, and on- t orbit checkout, the Enhanced Thematic Mapper Plus (ETM+) began the normal imaging phase of the mission in mid-July 1999. This paper presents the thermal performance of the ETM+ from mid-July 1999 to mid-May 2000. The flight temperatures are compared to the yellow temperature limits, and worst cold case and worst hot case flight temperature predictions in the 15-orbit mission design profile. The flight temperature predictions were generated by a thermal model, which was correlated to the observatory thermal balance test data. The yellow temperature limits were derived from the flight temperature predictions, plus some margins. The yellow limits work well in flight, so that only several minor changes to them were needed. Overall, the flight temperatures and flight temperature predictions have good agreement. Based on the ETM+ thermal vacuum qualification test, new limits on the imaging time are proposed to increase the average duty cycle, and to resolve the problems experienced by the Mission Operation Team.

  1. Hampson’s type cryocoolers with distributed Joule-Thomson effect for mixed refrigerants closed cycle

    NASA Astrophysics Data System (ADS)

    Maytal, Ben-Zion

    2014-05-01

    Most previous studies on Joule-Thomson cryocoolers of mixed refrigerants in a closed cycle focus on the Linde kind recuperator. The present study focuses on four constructions of Hampson’s kind miniature Joule-Thomson cryocoolers based on finned capillary tubes. The frictional pressure drop along the tubes plays the role of distributed Joule-Thomson expansion so that an additional orifice or any throttle at the cold end is eliminated. The high pressure tube is a throttle and a channel of recuperation at the same time. These coolers are tested within two closed cycle systems of different compressors and different compositions of mixed coolants. All tests were driven by the same level of discharge pressure (2.9 MPa) while the associated suction pressures and the associated reached temperatures are dependent on each particular cryocooler and on the closed cycle system. The mixture of higher specific cooling capacity cannot reach temperatures below 80 K when driven by the smaller compressor. The other mixture of lower specific cooling capacity driven by the larger compressor reaches lower temperatures. The examined parameters are the cooldown period and the reachable temperatures by each cryocooler.

  2. Mechanical qualification of the support structure for MQXF, the Nb 3Sn low-β quadrupole for the high luminosity LHC

    DOE PAGES

    Juchno, M.; Ambrosio, G.; Anerella, M.; ...

    2016-01-26

    Within the scope of the High Luminosity LHC project, the collaboration between CERN and U.S. LARP is developing new low-β quadrupoles using the Nb 3Sn superconducting technology for the upgrade of the LHC interaction regions. The magnet support structure of the first short model was designed and two units were fabricated and tested at CERN and at LBNL. The structure provides the preload to the collars-coils subassembly by an arrangement of outer aluminum shells pre-tensioned with water-pressurized bladders. For the mechanical qualification of the structure and the assembly procedure, superconducting coils were replaced with solid aluminum “dummy coils”, the structuremore » was preloaded at room temperature, and then cooled-down to 77 K. Mechanical behavior of the magnet structure was monitored with the use of strain gauges installed on the aluminum shells, the dummy coils and the axial preload system. As a result, this paper reports on the outcome of the assembly and the cool-down tests with dummy coils, which were performed at CERN and at LBNL, and presents the strain gauge measurements compared to the 3D finite element model predictions.« less

  3. Development of a Molecular Tagging Velocimetry Technique for Non-Intrusive Velocity Measurements in Low-Speed Gas Flows

    NASA Technical Reports Server (NTRS)

    Andre, M. A.; Bardet, P. M.; Cadell, S. R.; Woods, B.; Burns, R. A.; Danehy, P. M.

    2017-01-01

    N2O molecular tagging velocimetry (N2O-MTV) is developed for use in very-high-temperature reactor environments. Tests were carried out to determine the optimum excitation wavelength, tracer concentration, and timing parameters for the laser system. Using NO tracers obtained from photo-dissociation of N2O, velocity profiles are successfully obtained in air, nitrogen, and helium for a large range of parameters: temperature from 295 to 781 K, pressure from 1 to 3 bars, with a velocity precision of 0.01 m/s. Furthermore, by using two read pulses at adjustable time delays, the velocity dynamic range can be increased. An unprecedented dynamic range of 5,000 has been obtained to successfully resolve the flow during a helium blowdown from 1000 m/s down to 0.2 m/s. This technique is also applied to the high-temperature test facility (HTTF) at Oregon State University (OSU) during a depressurized condition cooldown (DCC) event. Details of these measurements are presented in a companion paper. This technique shows a strong potential for fundamental understanding of gas flows in nuclear reactors and to provide benchmark experimental data to validate numerical simulations.

  4. Tube furnace

    DOEpatents

    Foster, Kenneth G.; Frohwein, Eugene J.; Taylor, Robert W.; Bowen, David W.

    1991-01-01

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  5. NUMBER AND TYPE OF OPERATING CYCLES FOR THE FFTF

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boyd, D. C.

    1969-05-15

    The choice of materials and other vessel design decisions necessary to provide the desired life expectancy for the FTR vessel are partially dependent upon estimates of the number and type of reactor shutdowns and startups which may be anticipated. Current estimates of these so-called "cycles" are given, including scram frequency, experimental outage frequency, standard shutdowns and startups, and rapid controlled shutdowns. Also discussed are abnormal heatup or cooldown, and tentative goals for temperature controls. MTR, ETR, and typical PRTR operating histories are tabulated.

  6. Seeded Physical Vapor Transport of Cadmium-Zinc Telluride Crystals: Growth and Characterization

    NASA Technical Reports Server (NTRS)

    Palosz, W.; George, M. A.; Collins, E. E.; Chen, K.-T.; Zhang, Y.; Burger, A.

    1997-01-01

    Crystals of Cd(1-x)Zn(x)Te with x = 0.2 and 40 g in weight were grown on monocrystalline cadmium-zinc telluride seeds by closed-ampoule physical vapor transport with or without excess (Cd + Zn) in the vapor phase. Two post-growth cool-down rates were used. The crystals were characterized using low temperature photoluminescence, atomic force microscopy, chemical etching, X-ray diffraction and electrical measurements. No formation of a second, ZnTe-rich phase was observed.

  7. Freely oriented portable superconducting magnet

    DOEpatents

    Schmierer, Eric N [Los Alamos, NM; Prenger, F Coyne [Los Alamos, NM; Hill, Dallas D [Los Alamos, NM

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  8. Moisture-Induced Delamination Video of an Oxidized Thermal Barrier Coating

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Zhu, Dongming; Cuy, Michael D.

    2008-01-01

    PVD TBC coatings were thermally cycled to near-failure at 1150 C. Normal failure occurred after 200-300 1-hr cycles with only moderate weight gains (0.5 mg/cm2). Delamination and buckling was often delayed until well after cooldown (desktop spallation), but could be instantly induced by the application of water drops, as shown in an accompanying video-recording. Moisture therefore plays a primary role in delayed desktop TBC failure. Hydrogen embrittlement is proposed as the underlying mechanism.

  9. Using a Gravity Model to Predict Circulation in a Public Library System.

    ERIC Educational Resources Information Center

    Ottensmann, John R.

    1995-01-01

    Describes the development of a gravity model based upon principles of spatial interaction to predict the circulation of libraries in the Indianapolis-Marion County Public Library (Indiana). The model effectively predicted past circulation figures and was tested by predicting future library circulation, particularly for a new branch library.…

  10. High-Reynolds Number Circulation Control Testing in the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Milholen, William E., II; Jones, Gregory S.; Chan, David T.; Goodliff, Scott L.

    2012-01-01

    A new capability to test active flow control concepts and propulsion simulations at high Reynolds numbers in the National Transonic Facility at the NASA Langley Research Center is being developed. The first active flow control experiment was completed using the new FAST-MAC semi-span model to study Reynolds number scaling effects for several circulation control concepts. Testing was conducted over a wide range of Mach numbers, up to chord Reynolds numbers of 30 million. The model was equipped with four onboard flow control valves allowing independent control of the circulation control plenums, which were directed over a 15% chord simple-hinged flap. Preliminary analysis of the uncorrected lift data showed that the circulation control increased the low-speed maximum lift coefficient by 33%. At transonic speeds, the circulation control was capable of positively altering the shockwave pattern on the upper wing surface and reducing flow separation. Furthermore, application of the technique to only the outboard portion of the wing demonstrated the feasibility of a pneumatic based roll control capability.

  11. Playing-Related Musculoskeletal Disorders Among Classical Piano Students at Tertiary Institutions in Malaysia: Proportion and Associated Risk Factors.

    PubMed

    Ling, Chia-Ying; Loo, Fung-Chiat; Hamedon, Titi R

    2018-06-01

    Musicians are prone to performance injuries due to the nature of musical practice, and classical pianists are among the groups at high risk for playing-related musculoskeletal disorders (PRMDs). With the growing number of classical pianists in Malaysia, this study aimed to investigate the proportion of PRMDs occurring among classical piano students in tertiary institutions in Malaysia. Associations between gender, practice habits, diet, sports involvement, and PRMD were investigated. A survey was conducted among classical piano students (n=192) at tertiary institutions of Kuala Lumpur and Selangor. Results showed that 35.8% (n=68) students reported having PRMD. The shoulder was the most commonly affected body site, followed by the arm, finger, and wrist. Pain, fatigue, and stiffness were the most cited symptoms by those who suffered from a PRMD. Chi-square analysis showed a significant relationship between the occurrence of PRMD and practice hours (p=0.031), the habit of taking breaks during practice (p=0.045), physical cool-down exercises (p=0.037), and special diet (p=0.007). Multivariate logistic regression analyses confirmed the independent correlation between PRMDs and the lack of taking a break during practice, physical cool-down exercises, and special diet. Because PRMDs are reported at various severity levels, this study should increase awareness of PRMD among classical piano students and encourage injury prevention in musicians in the future to ensure long-lasting music careers.

  12. Study of lubricant circulation in HVAC systems. Volume 1: Description of technical effort and results; Final technical report, March 1995--April 1996

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Biancardi, F.R.; Michels, H.H.; Sienel, T.H.

    1996-10-01

    The purpose of this program was to conduct experimental and analytical efforts to determine lubricant circulation characteristics of new HFC/POE pairs and HFC/mineral oil pairs in a representative central residential HVAC system and to compare their behavior with the traditional HCFC-22/mineral oil (refrigerant/lubricant) pair. A dynamic test facility was designed and built to conduct the experimental efforts. This facility provided a unique capability to visually and physically measure oil circulation rates, on-line, in operating systems. A unique on-line ultraviolet-based measurement device was used to obtain detailed data on the rate and level of lubricant oil circulated within the operating heatmore » pump system. The experimental and analytical data developed during the program are presented as a function of vapor velocity, refrigerant/lubricant viscosity, system features and equipment. Both visual observations and instrumentation were used to understand ``worst case`` oil circulation situations. This report is presented in two volumes. Volume 1 contains a complete description of the program scope, objective, test results summary, conclusions, description of test facility and recommendations for future effort. Volume 2 contains all of the program test data essentially as taken from the laboratory dynamic test facility during the sequence of runs.« less

  13. Experimental Investigation of Natural-Circulation Flow Behavior Under Low-Power/Low-Pressure Conditions in the Large-Scale PANDA Facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Auban, Olivier; Paladino, Domenico; Zboray, Robert

    2004-12-15

    Twenty-five tests have been carried out in the large-scale thermal-hydraulic facility PANDA to investigate natural-circulation and stability behavior under low-pressure/low-power conditions, when void flashing might play an important role. This work, which extends the current experimental database to a large geometric scale, is of interest notably with regard to the start-up procedures in natural-circulation-cooled boiling water reactors. It should help the understanding of the physical phenomena that may cause flow instability in such conditions and can be used for validation of thermal-hydraulics system codes. The tests were performed at a constant power, balanced by a specific condenser heat removal capacity.more » The test matrix allowed the reactor pressure vessel power and pressure to be varied, as well as other parameters influencing the natural-circulation flow. The power spectra of flow oscillations showed in a few tests a major and unique resonance peak, and decay ratios between 0.5 and 0.9 have been found. The remainder of the tests showed an even more pronounced stable behavior. A classification of the tests is presented according to the circulation modes (from single-phase to two-phase flow) that could be assumed and particularly to the importance and the localization of the flashing phenomenon.« less

  14. Circulation and Purification in the LUX-ZEPLIN System Test

    NASA Astrophysics Data System (ADS)

    Alsum, Shaun; Lz Collaboration

    2016-03-01

    LZ is a dark-matter direct detection experiment whose detector is a two-phase TPC using approximately seven tons of active xenon as its scintillator. The xenon must have few electronegative impurities to ensure sufficient electron transport through the drift region. The LZ purification system is being prototyped in the LZ system test, a test platform located at SLAC using about 100kg of Xenon, which consists of gas circulation through a SAES getter. We utilize a dual-phase and a gas-phase heat exchanger to reduce needed cooling power. To achieve this circulation we employ an all metal seal triple diaphragm pump, also prototyped in the System Test. This talk will present early results from the system test as well as some baseline LZ designs. The LUX-ZEPLIN dark matter direct detection experiment.

  15. Moisture-Induced Delamination Video of an Oxidized Thermal Barrier Coating

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Zhu, Dongming; Cuy, Michael D.

    2008-01-01

    PVD TBC coatings were thermally cycled to near-failure at 1150 C. Normal failure occurred after 200 to 300 1-hr cycles with only moderate weight gains (0.5 mg/sq cm). Delamination and buckling was often delayed until well after cooldown (desktop spallation), but could be instantly induced by the application of water drops, as shown in a video clip which can be viewed by clicking on figure 2 of this report. Moisture therefore plays a primary role in delayed desktop TBC failure. Hydrogen embrittlement is proposed as the underlying mechanism.

  16. Testing of a Neon Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin Lee

    2014-01-01

    Cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks is required for future NASA missions. A cryogenic loop heat pipe (CLHP) can provide a closed-loop cooling system for this purpose and has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A neon CLHP was tested extensively in a thermal vacuum chamber using a cryopump as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components. Tests conducted included loop cool-down from the ambient temperature, startup, power cycle, heat removal capability, loop capillary limit and recovery from a dry-out, low power operation, and long duration steady state operation. The neon CLHP demonstrated robust operation. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully by applying power to both the pump and evaporator without any pre-conditioning. It could adapt to changes in the pump power andor evaporator power, and reach a new steady state very quickly. The evaporator could remove heat loads between 0.25W and 4W. When the pump capillary limit was exceeded, the loop could resume its normal function by reducing the pump power. Steady state operations were demonstrated for up to 6 hours. The ability of the neon loop to cool large areas was therefore successfully verified.

  17. Significance of Landsat-7 Spacecraft Level Thermal Balance and Thermal Test for ETM+Instrument

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.

    1999-01-01

    The thermal design and the instrument thermal vacuum (T/V) test of the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) instrument were based on the Landsat-4, 5 and 6 heritage. The ETM+ scanner thermal model was also inherited from Landsat-4, 5 and 6. The temperature predictions of many scanner components in the original thermal model had poor agreement with the spacecraft and instrument integrated sun-pointing safehold (SPSH) thermal balance (T/B) test results. The spacecraft and instrument integrated T/B test led to a change of the Full Aperture Calibrator (FAC) motor stack "solar shield" coating from MIL-C-5541 to multi-layer insulation (MLI) thermal blanket. The temperature predictions of the Auxiliary Electronics Module (AEM) in the thermal model also had poor agreement with the T/B test results. Modifications to the scanner and AEM thermal models were performed to give good agreement between the temperature predictions and the test results. The correlated ETM+ thermal model was used to obtain flight temperature predictions. The flight temperature predictions in the nominal 15-orbit mission profile, plus margins, were used as the yellow limits for most of the ETM+ components. The spacecraft and instrument integrated T/B and TN test also revealed that the standby heater capacity on the Scan Mirror Assembly (SMA) was insufficient when the Earth Background Simulator (EBS) was 1 50C or colder, and the baffle heater possibly caused the coherent noise in the narrow band data when it was on. Also, the cooler cool-down was significantly faster than that in the instrument T/V test, and the coldest Cold Focal Plane Array (CFPA) temperature achieved was colder.

  18. Heat Exchanger Can Assembly for Provision of Helium Coolant Streams for Cryomodule Testing below 2K

    NASA Astrophysics Data System (ADS)

    Smith, E. N.; Eichhorn, R.; Quigley, P.; Sabol, D.; Shore, C.; Widger, D.

    2017-02-01

    A series of heat exchanger can (HXC) assemblies have been designed, constructed and built to utilize existing 4.2 K liquefaction and compressor capabilities to provide helium gas coolant streams of 80 K, 4.5 K, and liquid from 1.6 to 2.0 K for operating cryomodules containing from one to six superconducting RF cavities built for an energy recovery linear accelerator. Designs for the largest assemblies required up to 100 W of cooling at 1.8 K with precise temperature control, especially during cool-down, and up to 2000 W at 80 K (with a 40 K temperature rise). A novel feature of these assemblies was the use of relatively inexpensive brazed stainless steel plate heat exchangers intended for room-temperature operation with water or oil, but which in practice worked well at cryogenic temperatures. The choice of operating temperatures/pressures were to provide single-phase helium flow for better control of coolant distribution in the 80 K and 4.5 K streams, to take advantage of locally elevated heat capacity near the critical point for the 4.5 K stream, and in the region below 2 K to get the best possible Q from the niobium cavities under test.

  19. Elevated circulating level of osteopontin is associated with advanced disease state of non-small cell lung cancer.

    PubMed

    Chang, Yoon Soo; Kim, Hyung Jung; Chang, Joon; Ahn, Chul Min; Kim, Sung Kyu; Kim, Se Kyu

    2007-09-01

    Osteopontin (OPN) plays important roles in tumor progression and metastasis through binding to OPN receptors such as alpha(v)beta(beta) integrin and CD44, and its overexpression in tumor is associated poor clinical outcome of NSCLC patients. Circulating OPN levels, measured by ELISA in 130 NSCLC cases that had not been treated for cancer at the time of sampling, were analyzed according to clinical, pathologic parameters and single nucleotide polymorphisms (SNPs) in the OPN gene promoter. Advanced disease states had higher circulating levels of OPN (T4 versus T1-3, N3 versus N0-2, and M1 versus M0, P=.029, .001, and .001, respectively, Kruskal-Wallis H-test), reflected by higher level of OPN in stage IV than stage I-III (P=.029, Kruskal-Wallis H-test). Among the clinical and pathological parameters including age, gender, smoking status, histologic subtypes and grade of differentiation, smoking status influences circulating OPN level showing higher level of OPN in ex-smokers than current and non-smokers (P=.038, Kruskal-Wallis H-test). Variation at nucleotide (nt) -443 of the OPN gene promoter had no influence on circulating OPN levels, however, patients with G/G at nt -156 showed higher concentrations of OPN than those with G/GG or GG/GG (P=.003, Kruskal-Wallis H-test). A patient with G/G at nt -156 was more frequently diagnosed with advanced stage (IIIB-IV) than with early stage (I-IIIA) NSCLC (P=.048, Mantel-Haenszel-test). In multivariate analysis, stage is the only independent factor influencing circulating level of OPN. Although circulating level of OPN in the patients with bone metastasis was higher than in those without bone metastasis (P=.028, Mann-Whitney U-test), there was no difference in the OPN levels between bone metastasis group and non-bone metastasis group. Given that the elevated levels of OPN is associated with advanced stages of NSCLC, elucidating OPN regulatory mechanisms may contribute to the development of a new therapeutic modality for NSCLC.

  20. Thermal-Mechanical Stress Analysis of PWR Pressure Vessel and Nozzles under Grid Load-Following Mode: Interim Report on the Effect of Cyclic Hardening Material Properties and Pre-existing Cracks on Stress Analysis Results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohanty, Subhasish; Soppet, William; Majumdar, Saurin

    This report provides an update on an assessment of environmentally assisted fatigue for light water reactor components under extended service conditions. This report is a deliverable under the work package for environmentally assisted fatigue as part of DOE’s Light Water Reactor Sustainability Program. In a previous report (September 2015), we presented tensile and fatigue test data and related hardening material properties for 508 low-alloys steel base metal and other reactor metals. In this report, we present thermal-mechanical stress analysis of the reactor pressure vessel and its hot-leg and cold-leg nozzles based on estimated material properties. We also present results frommore » thermal and thermal-mechanical stress analysis under reactor heat-up, cool-down, and grid load-following conditions. Analysis results are given with and without the presence of preexisting cracks in the reactor nozzles (axial or circumferential crack). In addition, results from validation stress analysis based on tensile and fatigue experiments are reported.« less

  1. Eutectic Experiment Development for Space Processing

    NASA Technical Reports Server (NTRS)

    Hopkins, R. H.

    1972-01-01

    A ground base test plan and a specimen evaluation scheme have been developed for the aluminum-copper eutectic solidification experiment to be run in the M518 multipurpose electric furnace during the Skylab mission. Besides thermal and solidification studies a detailed description is given of the quantitative metallographic technique which is appropriate for characterizing eutectic structures. This method should prove a key tool for evaluating specimen microstructure which is the most sensitive indicator of changes produced during solidification. It has been recommended that single grain pre-frozen eutectic specimens be used to simplify microstructural evaluation and to eliminate any porosity in the as-cast eutectic specimens. High purity (99.999%) materials from one supplier should be employed for all experiments. Laboratory studies indicate that porosity occurs in the MRC as-cast eutectic ingots but that this porosity can be eliminated by directional freezing. Chemical analysis shows that the MRC ingots are slightly Al rich and contain about .03% impurity. Because of the impurity content the lower cooldown rate (1.2 C/min) should be used for eutectic freezing if MRC material is used in the M518 furnace.

  2. Effects of a Single-Session Cognitive Enhancement Fitness Program on Serum Brain-Derived Neurotrophic Factor Levels and Cognitive Function in Middle-Aged Women

    PubMed Central

    Kim, Hyun Jun; Lee, Sang Yeoup; Lee, Hwa Gyeong; Cho, Yang Hee; Ko, Eun Mi

    2018-01-01

    Few studies have been undertaken to develop cognitive functional improvement-focused exercise programs and determine their effect. The objectives of this study were to evaluate the effects of a cognitive enhancement fitness program (CEFP) on short-term memory and serum brain-derived neurotrophic factor (BDNF) levels according to the cognitive state in middle-aged women. A total of 30 healthy volunteers aged 40–59 years were divided into two groups, that is, a mild cognitive impairment (MCI) group and a non-MCI group based on results from the Korean Dementia Screening Questionnaire. A single-session CEFP was conducted over 50 min and consisted of four parts: warm-up, low intensity interval circulation dance exercises, moderate intensity resistance exercises using elastic bands, and cool-down. Serum BDNF levels were measured by ELISA and short-term memory determined by forward digit/word span test was assessed before and after CEFP. After CEFP, forward digit/word span test scores and BDNF levels increased to median 119.2%/115.1% and 118.7%, respectively. After CEFP, the MCI and non-MCI groups produced higher forward digit span test scores (from 6.7 ± 1.5 to 7.5 ± 1.4 points, p = 0.023 and from 6.2 ± 2.0 to 7.0 ± 2.1 points, P=0.011, respectively). After CEFP, forward word span scores and BDNF levels increased (from 3.5 ± 1.7 to 4.6 ± 1.8 points, p = 0.029 and from 610.8 ± 221.1 to 757.9 ± 267.9 pg/ml, p = 0.017, respectively) in non-MCI group only. No group differences were observed between change in short-term memory and change in BDNF. Short-term memory and BDNF levels after CEFP were found to be negatively correlated with age, but pre- to post-intervention changes in short-term memory and BDNF were not. The present study shows that a single, 50-minute CEFP improved short-term memory and increased serum BDNF levels in healthy middle-aged women, especially those without MCI. Key points A single 50-minute CEFP comprised 5 minutes of general warm up and mat stretching, 20 minutes of low intensity activities with 8 dance exercises (RPE 11-12), another 20 minutes of moderate intensity activities including 8 resistance exercises using elastic bands ((RPE 13-15), and finally a 5-minute general cool down with yoga. Both MCI and non-MCI groups produced higher forward digit span test scores and had higher serum BDNF levels after CEFP but forward word span scores were increased only in non-MCI. A single 50-minute brain fitness program improved short-term memory and increased serum BDNF levels in healthy middle-aged women, especially those without MCI. PMID:29535584

  3. First Tracer Test After Circulation in Desert Peak 27-15

    DOE Data Explorer

    Rose, Peter

    2013-11-16

    Following the successful stimulation of Desert Peak target EGS well 27-15, a circulation test was initiated by injecting a conservative tracer (1,5-nds) in combination with a reactive tracer (7-amino-1,3-naphthalene disulfonate). The closest production well 74-21 was monitored over the subsequent several months.

  4. 78 FR 19606 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Furnace Fans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    ... electrically-powered devices used in central HVAC systems for the purposes of circulating air through ductwork...- powered device used in a central HVAC system for the purpose of circulating air through ductwork. DOE... included single-phase, electrically-powered devices that circulate air through ductwork in HVAC systems...

  5. Aerogel Insulation Applications for Liquid Hydrogen Launch Vehicle Tanks

    NASA Technical Reports Server (NTRS)

    Fesmire, J. E.; Sass, J.

    2007-01-01

    Aerogel based insulation systems for ambient pressure environments were developed for liquid hydrogen (LH2) tank applications. Solutions to thermal insulation problems were demonstrated for the Space Shuttle External Tank (ET) through extensive testing at the Cryogenics Test Laboratory. Demonstration testing was performed using a 1/10th scale ET LH2 intertank unit and liquid helium as the coolant to provide the 20 K cold boundary temperature. Cryopumping tests in the range of 20K were performed using both constant mass and constant pressure methods. Long-duration tests (up to 10 hours) showed that the nitrogen mass taken up inside the intertank is reduced by a factor of nearly three for the aerogel insulated case as compared to the un-insulated (bare metal flight configuration) case. Test results including thermal stabilization, heat transfer effectiveness, and cryopumping confirm that the aerogel system eliminates free liquid nitrogen within the intertank. Physisorption (or adsorption) of liquid nitrogen within the fine pore structure of aerogel materials was also investigated. Results of a mass uptake method show that the sorption ratio (liquid nitrogen to aerogel beads) is about 62 percent by volume. A novel liquid nitrogen production method of testing the liquid nitrogen physical adsorption capacity of aerogel beads was also performed to more closely approximate the actual launch vehicle cooldown and thermal stabilization effects within the aerogel material. The extraordinary insulating effectiveness of the aerogel material shows that cryopumping is not an open-cell mass transport issue but is strictly driven by thermal communication between warm and cold surfaces. The new aerogel insulation technology is useful to solve heat transfer problem areas and to augment existing thermal protection systems on launch vehicles. Examples are given and potential benefits for producing launch systems that are more reliable, robust, reusable, and efficient are outlined.

  6. Sex differences and the impact of steroid hormones on the developing human brain.

    PubMed

    Neufang, Susanne; Specht, Karsten; Hausmann, Markus; Güntürkün, Onur; Herpertz-Dahlmann, Beate; Fink, Gereon R; Konrad, Kerstin

    2009-02-01

    Little is known about the hormonal effects of puberty on the anatomy of the developing human brain. In a voxel-based morphometry study, sex-related differences in gray matter (GM) volume were examined in 46 subjects aged 8-15 years. Males had larger GM volumes in the left amygdala, whereas females had larger right striatal and bilateral hippocampal GM volumes than males. Sexually dimorphic areas were related to Tanner stages (TS) of pubertal development and to circulating level of steroid hormones in a subsample of 30 subjects. Regardless of sex, amygdala and hippocampal volumes varied as a function of TS and were associated with circulating testosterone (TEST) levels. By contrast, striatal GM volumes were unrelated to pubertal development and circulating steroid hormones. Whole-brain regression analyses revealed positive associations between circulating estrogen levels and parahippocampal GM volumes as well as between TEST levels and diencephalic brain structures. In addition, a negative association was found between circulating TEST and left parietal GM volumes. These data suggest that GM development in certain brain regions is associated with sexual maturation and that pubertal hormones might have organizational effects on the developing human brain.

  7. Thrust Removal Scheme for the FAST-MAC Circulation Control Model Tested in the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Chan, David T.; Milholen, William E., II; Jones, Gregory S.; Goodliff, Scott L.

    2014-01-01

    A second wind tunnel test of the FAST-MAC circulation control semi-span model was recently completed in the National Transonic Facility at the NASA Langley Research Center. The model allowed independent control of four circulation control plenums producing a high momentum jet from a blowing slot near the wing trailing edge that was directed over a 15% chord simple-hinged flap. The model was configured for transonic testing of the cruise configuration with 0deg flap deflection to determine the potential for drag reduction with the circulation control blowing. Encouraging results from analysis of wing surface pressures suggested that the circulation control blowing was effective in reducing the transonic drag on the configuration, however this could not be quantified until the thrust generated by the blowing slot was correctly removed from the force and moment balance data. This paper will present the thrust removal methodology used for the FAST-MAC circulation control model and describe the experimental measurements and techniques used to develop the methodology. A discussion on the impact to the force and moment data as a result of removing the thrust from the blowing slot will also be presented for the cruise configuration, where at some Mach and Reynolds number conditions, the thrust-removed corrected data showed that a drag reduction was realized as a consequence of the blowing.

  8. Radiation from Cardiac Imaging Tests

    MedlinePlus

    ... Bridging Disciplines Circulation at Major Meetings Special Themed Issues Global Impact of the 2017 ACC/AHA Hypertension Guidelines Circulation Supplements Cardiovascular Case Series ECG Challenge Hospitals of History Brigham and ...

  9. Enhancements to the FAST-MAC Circulation Control Model and Recent High-Reynolds Number Testing in the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Milholen, William E., II; Jones, Gregory S.; Chan, David T.; Goodliff, Scott L.; Anders, Scott G.; Melton, Latunia P.; Carter, Melissa B.; Allan, Brian G.; Capone, Francis J.

    2013-01-01

    A second wind tunnel test of the FAST-MAC circulation control model was recently completed in the National Transonic Facility at the NASA Langley Research Center. The model was equipped with four onboard flow control valves allowing independent control of the circulation control plenums, which were directed over a 15% chord simple-hinged flap. The model was configured for low-speed high-lift testing with flap deflections of 30 and 60 degrees, along with the transonic cruise configuration with zero degree flap deflection. Testing was again conducted over a wide range of Mach numbers up to 0.88, and Reynolds numbers up to 30 million based on the mean chord. The first wind tunnel test had poor transonic force and moment data repeatability at mild cryogenic conditions due to inadequate thermal conditioning of the balance. The second test demonstrated that an improvement to the balance heating system significantly improved the transonic data repeatability, but also indicated further improvements are still needed. The low-speed highlift performance of the model was improved by testing various blowing slot heights, and the circulation control was again demonstrated to be effective in re-attaching the flow over the wing at off-design transonic conditions. A new tailored spanwise blowing technique was also demonstrated to be effective at transonic conditions with the benefit of reduced mass flow requirements.

  10. Maternal plasma DNA testing for aneuploidy in pregnancies achieved by assisted reproductive technologies.

    PubMed

    Lambert-Messerlian, Geralyn; Kloza, Edward M; Williams, John; Loucky, Jaroslav; O'Brien, Barbara; Wilkins-Haug, Louise; Mahoney, Maurice J; De Biasio, Pierangela; Borrell, Antoni; Ehrich, Mathias; van den Boom, Dirk; Bombard, Allan T; Deciu, Cosmin; Palomaki, Glenn E

    2014-05-01

    We sought to compare measurements of circulating cell-free DNA as well as Down syndrome test results in women with naturally conceived pregnancies with those conceived using assisted reproductive technologies. Data regarding assisted reproductive technologies were readily available from seven enrollment sites participating in an external clinical validation trial of nested case/control design. Measurements of circulating cell-free fetal and total DNA, fetal fraction (ratio of fetal to total DNA), chromosome-specific z-scores, and karyotype results were available for analysis. Analyses were restricted to 632 euploid (5.2% assisted reproductive technologies) and 73 Down syndrome (13.7% assisted reproductive technologies), including 16 twin pregnancies. No differences were found for fetal or total circulating cell-free DNA, or for the fetal fraction in euploid (P = 0.70) or Down syndrome (P = 0.58) pregnancies by method of conception. There appeared to be systematic z-score reductions for chromosomes 21, 18, and 13 in assisted reproductive technologies versus natural euploid pregnancies (P = 0.048, 0.0032, and 0.36, respectively). Assisted reproductive technologies and naturally conceived pregnancies contribute similar levels of circulating cell-free DNA into maternal circulation. Small differences in the z-scores of pregnancies achieved by assisted reproductive technologies were observed and do not appear to be test-related artifacts. However, the findings need confirmation before any consideration of changes to testing and reporting protocols.

  11. Sensitivity analysis of cool-down strategies for a transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Thibodeaux, J. J.

    1982-01-01

    Guidelines and suggestions substantiated by real-time simulation data to ensure optimum time and energy use of injected liquid nitrogen for cooling the Langley 0.3-Meter Transonic Cryogenic Tunnel (TCT) are presented. It is directed toward enabling operators and researchers to become cognizant of criteria for using the 0.3-m TCT in an energy- or time-efficient manner. Operational recommendations were developed based on information collected from a validated simulator of the 0.3-m TCT and experimental data from the tunnel. Results and trends, however, can be extrapolated to other similarly constructed cryogenic wind tunnels.

  12. Warpage of Large Curved Composite Panels due to Manufacturing Anomalies

    NASA Technical Reports Server (NTRS)

    Starnes, James H., Jr. (Technical Monitor); Ambur, Damadar (Technical Monitor); Ochinero, T. T.; Hyer, M. W.

    2002-01-01

    This paper discusses the influences of a misaligned layer, a resin-rich slightly thicker layer, and a small thermal gradient on the thermally-induced deformations of large curved composite panels during cooldown from their cure temperature. The deformations represent warpage of the panels due to anomalies that occur during layup, consolidation, and cure. Two-dimensional finite element analyses are used The deformations are categorized as to their impact on circumferential and twist warpage metrics. The results are intended to highlight the sensitivity of manufactured panel shape to the various unwanted effects that can occur during manufacturing.

  13. Optimal fabrication processes for unidirectional metal-matrix composites: A computational simulation

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with non-linear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  14. Optimal fabrication processes for unidirectional metal-matrix composites - A computational simulation

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with nonlinear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  15. Flux trapping in multi-loop SQUIDs and its impact on SQUID-based absolute magnetometry

    NASA Astrophysics Data System (ADS)

    Schönau, T.; Zakosarenko, V.; Schmelz, M.; Anders, S.; Meyer, H.-G.; Stolz, R.

    2018-07-01

    The effect of flux trapping on the flux-voltage characteristics of multi-loop SQUID magnetometers was investigated by means of repeated cool-down cycles in a stepwise increased magnetic background field. For a SQUID with N parallel loops, N different flux offsets, each separated by {{{Φ }}}0/N, were observed even in zero magnetic field. These flux offsets further split into a so called fine structure, which can be explained by minor asymmetries in the SQUID design. The observed results are discussed with particular regard to their impact on the previously presented absolute SQUID cascade vector magnetometer.

  16. Reproducibility and calibration of MMC-based high-resolution gamma detectors

    DOE PAGES

    Bates, C. R.; Pies, C.; Kempf, S.; ...

    2016-07-15

    Here, we describe a prototype γ-ray detector based on a metallic magnetic calorimeter with an energy resolution of 46 eV at 60 keV and a reproducible response function that follows a simple second-order polynomial. The simple detector calibration allows adding high-resolution spectra from different pixels and different cool-downs without loss in energy resolution to determine γ-ray centroids with high accuracy. As an example of an application in nuclear safeguards enabled by such a γ-ray detector, we discuss the non-destructive assay of 242Pu in a mixed-isotope Pu sample.

  17. Field estimates of groundwater circulation depths in two mountainous watersheds in the western U.S. and the effect of deep circulation on solute concentrations in streamflow

    NASA Astrophysics Data System (ADS)

    Frisbee, Marty D.; Tolley, Douglas G.; Wilson, John L.

    2017-04-01

    Estimates of groundwater circulation depths based on field data are lacking. These data are critical to inform and refine hydrogeologic models of mountainous watersheds, and to quantify depth and time dependencies of weathering processes in watersheds. Here we test two competing hypotheses on the role of geology and geologic setting in deep groundwater circulation and the role of deep groundwater in the geochemical evolution of streams and springs. We test these hypotheses in two mountainous watersheds that have distinctly different geologic settings (one crystalline, metamorphic bedrock and the other volcanic bedrock). Estimated circulation depths for springs in both watersheds range from 0.6 to 1.6 km and may be as great as 2.5 km. These estimated groundwater circulation depths are much deeper than commonly modeled depths suggesting that we may be forcing groundwater flow paths too shallow in models. In addition, the spatial relationships of groundwater circulation depths are different between the two watersheds. Groundwater circulation depths in the crystalline bedrock watershed increase with decreasing elevation indicative of topography-driven groundwater flow. This relationship is not present in the volcanic bedrock watershed suggesting that both the source of fracturing (tectonic versus volcanic) and increased primary porosity in the volcanic bedrock play a role in deep groundwater circulation. The results from the crystalline bedrock watershed also indicate that relatively deep groundwater circulation can occur at local scales in headwater drainages less than 9.0 km2 and at larger fractions than commonly perceived. Deep groundwater is a primary control on streamflow processes and solute concentrations in both watersheds.

  18. The Clinical Utilization of Circulating Cell Free DNA (CCFDNA) in Blood of Cancer Patients

    PubMed Central

    Elshimali, Yahya I.; Khaddour, Husseina; Sarkissyan, Marianna; Wu, Yanyuan; Vadgama, Jaydutt V.

    2013-01-01

    Qualitative and quantitative testing of circulating cell free DNA (CCFDNA) can be applied for the management of malignant and benign neoplasms. Detecting circulating DNA in cancer patients may help develop a DNA profile for early stage diagnosis in malignancies. The technical issues of obtaining, using, and analyzing CCFDNA from blood will be discussed. PMID:24065096

  19. Effects of menstrual cycle, oral contraception, and training on exercise-induced changes in circulating DHEA-sulphate and testosterone in young women.

    PubMed

    Enea, C; Boisseau, N; Ottavy, M; Mulliez, J; Millet, C; Ingrand, I; Diaz, V; Dugué, B

    2009-06-01

    The objective of this study was to ascertain the effects of menstrual cycle, oral contraception, and training status on the exercise-induced changes in circulating DHEA-sulphate and testosterone in young women. Twenty-eight healthy women were assigned to an untrained group (n = 16) or a trained group (n = 12) depending on their training background. The untrained group was composed of nine oral contraceptive users (OC+) and seven eumenorrheic women (OC-). The trained group was composed of OC+ subjects only. All the OC+ subjects were taking the same low-dose oral contraception. Three laboratory sessions were organised in a randomised order: a prolonged exercise test until exhaustion, a short-term exhaustive exercise test, and a control session. Blood specimens were collected before, during and after the exercise tests and at the same time of the day during the control session. Basal circulating testosterone was significantly lower in trained as compared to untrained subjects. In all subjects, the prolonged exhaustive exercise induced a significant increase in circulating DHEA-s and testosterone. The short-term exercise induced a significant increase in circulating DHEA-s in untrained eumenorrheic and in trained OC users only. Menstrual phases in OC- did not influence the responses. It was found that exhaustive physical exercise induced an increase in circulating DHEA-s and testosterone in young women. Oral contraception may limit short-term exercise-induced changes.

  20. Testing of a heat pump clothes dryer. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McFadden, D.; Dieckmann, J.; Mallory, D.

    1995-05-01

    The integration of a heat pump heat source into a clothes dryer has been investigated by several U.S. and foreign appliance developers and manufacturers but no commercial or residential heat pump clothes dryers are currently available in North America. The objectives of this effort were to: (1) Evaluate a heat pump dryer prototype relative to residential dryer performance tests. (2) Quantify the product limitations. (3) Suggest design changes that would reduce the impact of the limitations or that have a positive impact on the benefits. (4) Position the product relative to utility DSM/IRP opportunities (e.g., reduced connected load, or energymore » conservation). (5) Develop preliminary cost data The program evaluated the performance of a prototype closed-cycle heat pump clothes dryer designed and built by the Nyle Corporation. The prototype design goals were: (1) Drying times equivalent to a conventional electric clothes dryer. (2) 60% reduction in energy consumption. (3) Effective lint removal (to prevent coil fouling). (4) Cool-down mode performance similar to conventional dryer. (5) 20 lb load capacity. (6) Low temperature dry for reduced clothes wrinkle. Test results indicated that the closed-cycle heat pump met some of the above mentioned goals but it fell short with respect to energy savings and dry time. Performance improvement recommendations were developed for the closed-cycle dryer approach. In addition, the closed-cycle design potential was compared to an open-cycle heat pump dryer configuration.« less

  1. Psycho-physiological analysis of an aerobic dance programme for women

    PubMed Central

    Rockefeller, Kathleen A.; Burke, E. J.

    1979-01-01

    The purpose of this study was to determine: (1) the energy cost and (2) the psycho-physiological effects of an aerobic dance programme in young women. Twenty-one college-age women participated 40 minutes a day, three days a week, for a 10-week training period. Each work session included a five-minute warm-up period, a 30-minute stimulus period (including walk-runs) and a five-minute cool-down period. During the last four weeks of the training period, the following parameters were monitored in six of the subjects during two consecutive sessions: perceived exertion (RPE) utilising the Borg 6-20 scale, Mean = 13.19; heart rate (HR) monitored at regular intervals during the training session, Mean = 166.37; and estimated caloric expenditure based on measured oxygen consumption (V̇O2) utilising a Kofranyi-Michaelis respirometer, Mean = 289.32. Multivariate analysis of variance (MANOVA) computed between pre and post tests for the six dependent variables revealed a significant approximate F-ratio of 5.72 (p <.05). Univariate t-test analysis of mean changes revealed significant pre-post test differences for V̇O2 max expressed in ml/kg min-1, maximal pulmonary ventilation, maximal working capacity on the bicycle ergometer, submaximal HR and submaximal RPE. Body weight was not significantly altered. It was concluded that the aerobic dance training programme employed was of sufficient intensity to elicit significant physiological and psycho-physiological alterations in college-age women. PMID:465914

  2. Powering of an HTS dipole insert-magnet operated standalone in helium gas between 5 and 85 K

    NASA Astrophysics Data System (ADS)

    van Nugteren, J.; Kirby, G.; Bajas, H.; Bajko, M.; Ballarino, A.; Bottura, L.; Chiuchiolo, A.; Contat, P.-A.; Dhallé, M.; Durante, M.; Fazilleau, P.; Fontalva, A.; Gao, P.; Goldacker, W.; ten Kate, H.; Kario, A.; Lahtinen, V.; Lorin, C.; Markelov, A.; Mazet, J.; Molodyk, A.; Murtomäki, J.; Long, N.; Perez, J.; Petrone, C.; Pincot, F.; de Rijk, G.; Rossi, L.; Russenschuck, S.; Ruuskanen, J.; Schmitz, K.; Stenvall, A.; Usoskin, A.; Willering, G.; Yang, Y.

    2018-06-01

    This paper describes the standalone magnet cold testing of the high temperature superconducting (HTS) magnet Feather-M2.1-2. This magnet was constructed within the European funded FP7-EUCARD2 collaboration to test a Roebel type HTS cable, and is one of the first high temperature superconducting dipole magnets in the world. The magnet was operated in forced flow helium gas with temperatures ranging between 5 and 85 K. During the tests a magnetic dipole field of 3.1 T was reached inside the aperture at a current of 6.5 kA and a temperature of 5.7 K. These values are in agreement with the self-field critical current of the used SuperOx cable assembled with Sunam tapes (low-performance batch), thereby confirming that no degradation occurred during winding, impregnation, assembly and cool-down of the magnet. The magnet was quenched many tens of times by ramping over the critical current and no degradation nor training was evident. During the tests the voltage over the coil was monitored in the microvolt range. An inductive cancellation wire was used to remove the inductive component, thereby significantly reducing noise levels. Close to the quench current, drift was detected both in temperature and voltage over the coil. This drifting happens in a time scale of minutes and is a clear indication that the magnet has reached its limit. All quenches happened approximately at the same average electric field and thus none of the quenches occurred unexpectedly.

  3. Method of Generating Transient Equivalent Sink and Test Target Temperatures for Swift BAT

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.

    2004-01-01

    The NASA Swift mission has a 600-km altitude and a 22 degrees maximum inclination. The sun angle varies from 45 degrees to 180 degrees in normal operation. As a result, environmental heat fluxes absorbed by the Burst Alert Telescope (BAT) radiator and loop heat pipe (LHP) compensation chambers (CCs) vary transiently. Therefore the equivalent sink temperatures for the radiator and CCs varies transiently. In thermal performance verification testing in vacuum, the radiator and CCs radiated heat to sink targets. This paper presents an analytical technique for generating orbit transient equivalent sink temperatures and a technique for generating transient sink target temperatures for the radiator and LHP CCs. Using these techniques, transient target temperatures for the radiator and LHP CCs were generated for three thermal environmental cases: worst hot case, worst cold case, and cooldown and warmup between worst hot case in sunlight and worst cold case in the eclipse, and three different heat transport values: 128 W, 255 W, and 382 W. The 128 W case assumed that the two LHPs transport 255 W equally to the radiator. The 255 W case assumed that one LHP fails so that the remaining LHP transports all the waste heat from the detector array to the radiator. The 382 W case assumed that one LHP fails so that the remaining LHP transports all the waste heat from the detector array to the radiator, and has a 50% design margin. All these transient target temperatures were successfully implemented in the engineering test unit (ETU) LHP and flight LHP thermal performance verification tests in vacuum.

  4. Development and evaluation of endurance test system for ventricular assist devices.

    PubMed

    Sumikura, Hirohito; Homma, Akihiko; Ohnuma, Kentaro; Taenaka, Yoshiyuki; Takewa, Yoshiaki; Mukaibayashi, Hiroshi; Katano, Kazuo; Tatsumi, Eisuke

    2013-06-01

    We developed a novel endurance test system that can arbitrarily set various circulatory conditions and has durability and stability for long-term continuous evaluation of ventricular assist devices (VADs), and we evaluated its fundamental performance and prolonged durability and stability. The circulation circuit of the present endurance test system consisted of a pulsatile pump with a small closed chamber (SCC), a closed chamber, a reservoir and an electromagnetic proportional valve. Two duckbill valves were mounted in the inlet and outlet of the pulsatile pump. The features of the circulation circuit are as follows: (1) the components of the circulation circuit consist of optimized industrial devices, giving durability; (2) the pulsatile pump can change the heart rate and stroke length (SL), as well as its compliance using the SCC. Therefore, the endurance test system can quantitatively reproduce various circulatory conditions. The range of reproducible circulatory conditions in the endurance test circuit was examined in terms of fundamental performance. Additionally, continuous operation for 6 months was performed in order to evaluate the durability and stability. The circulation circuit was able to set up a wide range of pressure and total flow conditions using the SCC and adjusting the pulsatile pump SL. The long-term continuous operation test demonstrated that stable, continuous operation for 6 months was possible without leakage or industrial device failure. The newly developed endurance test system demonstrated a wide range of reproducible circulatory conditions, durability and stability, and is a promising approach for evaluating the basic characteristics of VADs.

  5. Comparative efficacy of antigen and antibody detection tests for human trichinellosis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ivanoska, D.; Cuperlovic, K.; Gamble, H.R.

    1989-02-01

    Sera collected from patients with suspected or confirmed exposure to Trichinella spiralis were tested for circulating parasite antigens and antiparasite antibodies. Using an immunoradiometric assay, excretory--secretory antigens from muscle-stage larvae of T. spiralis were detected in the sera of 47% of 62 patients with clinical trichinellosis and 13% of 39 patients without clinical signs but suspected of exposure to infected meat. In comparison, antibodies were detected using an indirect immunofluorescent test in the circulation of 100% of the 62 patients with clinical trichinellosis and 46% of the 39 patients with suspected exposure. The presence of antibodies specific to excretory-secretory productsmore » of T. spiralis muscle larvae was confirmed in the majority of the samples tested by a monoclonal antibody-based competitive inhibition assay. These results indicate that antibody detection is a more sensitive diagnostic method for human trichinellosis, but that antigen detection might be a useful confirmatory test because it is a direct demonstration of parasite products in the circulation.« less

  6. COBRA-WC pretest predictions and post-test analysis of the FOTA temperature distribution during FFTF natural-circulation transients

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khan, E.U.; George, T.L.; Rector, D.R.

    The natural circulation tests of the Fast Flux Test Facility (FFTF) demonstrated a safe and stable transition from forced convection to natural convection and showed that natural convection may adequately remove decay heat from the reactor core. The COBRA-WC computer code was developed by the Pacific Northwest laboratory (PNL) to account for buoyancy-induced coolant flow redistribution and interassembly heat transfer, effects that become important in mitigating temperature gradients and reducing reactor core temperatures when coolant flow rate in the core is low. This report presents work sponsored by the US Department of Energy (DOE) with the objective of checking themore » validity of COBRA-WC during the first 220 seconds (sec) of the FFTF natural-circulation (plant-startup) tests using recorded data from two instrumented Fuel Open Test Assemblies (FOTAs). Comparison of COBRA-WC predictions of the FOTA data is a part of the final confirmation of the COBRA-WC methodology for core natural-convection analysis.« less

  7. An investigation of voids formation mechanisms and their effects on freeze and thaw processes of lithium and lithium fluoride

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.; Yang, Jae-Young

    1991-01-01

    The mechanisms of void formation during the cooldown and freezing of lithium coolant within the primary loop of SP-100 type systems are investigated. These mechanisms are: (1) homogeneous nucleation; (2) heterogeneous nucleation; (3) normal segregation of helium gas dissolved in liquid lithium; and (4) shrinkage of lithium during freezing. To evaluate the void formation potential due to segregation, a numerical scheme that couples the freezing and mass diffusion processes in both the solid and liquid regions is developed. The results indicated that the formation of He bubbles is unlikely by either homogeneous or heterogeneous nucleation during the cooldown process. However, homogeneous nucleation of He bubbles following the segregation of dissolved He in liquid lithium ahead of the solid-liquid interface is likely to occur. Results also show that total volume of He void is insignificant when compared to that of shrinkage voids. In viewing this, the subsequent research focuses on the effects of shrinkage void forming during freezing of lithium on subsequent thaw processes are investigated using a numerical scheme that is based on a single (solid/liquid) cell approach. The cases of lithium-fluoride are also investigated to show the effect of larger volume shrinkage upon freezing on the freeze and thaw processes. Results show that a void forming at the wall appreciably reduces the solid-liquid interface velocity, during both freeze and thaw, and causes a substantial rise in the wall temperature during thaw. However, in the case of Li, the maximum wall temperature was much lower than the melting temperature of PWC-11, which is used as the structure material in the SP-100 system. Hence, it is included that a formation of hot spots is unlikely during the startup or restart of the SP-100 system.

  8. Ultra-high field magnets for whole-body MRI

    NASA Astrophysics Data System (ADS)

    Warner, Rory

    2016-09-01

    For whole-body MRI, an ultra-high field (UHF) magnet is currently defined as a system operating at 7 T or above. Over 70 UHF magnets have been built, all with the same technical approach originally developed by Magnex Scientific Ltd. The preferred coil configuration is a compensated solenoid. In this case, the majority of the field is generated by a simple long solenoid that stretches the entire length of the magnet. Additional coils are wound on a separate former outside the main windings with the purpose of balancing the homogeneity. Most of the magnets currently in operation are passively shielded systems where the magnet is surrounded by a steel box of 200-870 tonnes of carbon steel. More recently actively shielded magnets have been built for operation at 7 T; in this case the stray field is controlled by with reverse turns wound on a separate former outside the primary coils. Protection against quench damage is much more complex with an actively shielded magnet design due to the requirement to prevent the stray field from increasing during a quench. In the case of the 7 T 900 magnet this controlled by combining some of the screening coils into each section of the protection circuit. Correction of the field variations caused by manufacturing tolerances and environmental effects are made with a combination of superconducting shims and passive shims. Modern UHF magnets operate in zero boil-off mode with the use of cryocoolers with cooling capacity at 4.2 K. Although there are no cryogen costs associated with normal operation UHF magnets require a significant volume (10 000-20 000 l) of liquid helium for the cool-down. Liquid helium is expensive therefore new methods of cool-down using high-power cryocoolers are being implemented to reduce the requirement.

  9. Investigation of the possibility of using residual heat reactor energy

    NASA Astrophysics Data System (ADS)

    Aminov, R. Z.; Yurin, V. E.; Bessonov, V. N.

    2017-11-01

    The largest contribution to the probable frequency of core damage is blackout events. The main component of the heat capacity at each reactor within a few minutes following a blackout is the heat resulting from the braking of beta-particles and the transfer of gamma-ray energy by the fission fragments and their decay products, which is known as the residual heat. The power of the residual heat changes gradually over a long period of time and for a VVER-1000 reactor is about 15-20 MW of thermal power over 72 hours. Current cooldown systems increase the cost of the basic nuclear power plants (NPP) funds without changing the amount of electricity generated. Such systems remain on standby, accelerating the aging of the equipment and accordingly reducing its reliability. The probability of system failure increases with the duration of idle time. Furthermore, the reactor residual heat energy is not used. A proposed system for cooling nuclear power plants involves the use of residual thermal power to supply the station’s own needs in emergency situations accompanied by a complete blackout. The thermal power of residual heat can be converted to electrical energy through an additional low power steam turbine. In normal mode, the additional steam turbine generates electricity, which makes it possible to ensure spare NPP and a return on the investment in the reservation system. In this work, experimental data obtained from a Balakovo NPP was analyzed to determine the admissibility of cooldown of the reactors through the 2nd circuit over a long time period, while maintaining high-level parameters for the steam generated by the steam generators.

  10. Elastic-plastic finite element analyses of an unidirectional, 9 vol percent tungsten fiber reinforced copper matrix composite

    NASA Technical Reports Server (NTRS)

    Sanfeliz, Jose G.

    1993-01-01

    Micromechanical modeling via elastic-plastic finite element analyses were performed to investigate the effects that the residual stresses and the degree of matrix work hardening (i.e., cold-worked, annealed) have upon the behavior of a 9 vol percent, unidirectional W/Cu composite, undergoing tensile loading. The inclusion of the residual stress-containing state as well as the simulated matrix material conditions proved to be significant since the Cu matrix material exhibited plastic deformation, which affected the subsequent tensile response of the composite system. The stresses generated during cooldown to room temperature from the manufacturing temperature were more of a factor on the annealed-matrix composite, since they induced the softened matrix to plastically flow. This event limited the total load-carrying capacity of this matrix-dominated, ductile-ductile type material system. Plastic deformation of the hardened-matrix composite during the thermal cooldown stage was not considerable, therefore, the composite was able to sustain a higher stress before showing any appreciable matrix plasticity. The predicted room temperature, stress-strain response, and deformation stages under both material conditions represented upper and lower bounds characteristic of the composite's tensile behavior. The initial deformation stage for the hardened material condition showed negligible matrix plastic deformation while for the annealed state, its initial deformation stage showed extensive matrix plasticity. Both material conditions exhibited a final deformation stage where the fiber and matrix were straining plastically. The predicted stress-strain results were compared to the experimental, room temperature, tensile stress-strain curve generated from this particular composite system. The analyses indicated that the actual thermal-mechanical state of the composite's Cu matrix, represented by the experimental data, followed the annealed material condition.

  11. Innovative design of composite structures: Axisymmetric deformations of unsymmetrically laminated cylinders loaded in axial compression

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Paraska, P. J.

    1990-01-01

    The study focuses on the axisymmetric deformation response of unsymmetrically laminate cylinders loaded in axial compression by known loads. A geometrically nonlinear analysis is used. Though buckling is not studied, the deformations can be considered to be the prebuckling response. Attention is directed at three 16 layer laminates: a (90 sub 8/0 sub 8) sub T; a (0 sub 8/90 sub 8) sub T and a (0/90) sub 4s. The symmetric laminate is used as a basis for comparison, while the two unsymmetric laminates were chosen because they have equal but opposite bending-stretching effects. Particular attention is given to the influence of the thermally-induced preloading deformations that accompany the cool-down of any unsymmetric laminate from the consolidation temperature. Simple support and clamped boundary conditions are considered. It is concluded that: (1) The radial deformations of an unsymmetric laminate are significantly larger than the radial deformations of a symmetric laminate, although for both symmetric and unsymmetric laminates the large deformations are confined to a boundary layer near the ends of the cylinder; (2) For this nonlinear problem the length of the boundary layer is a function of the applied load; (3) The sign of the radial deformations near the supported end of the cylinder depends strongly on the sense (sign) of the laminate asymmetry; (4) For unsymmetric laminates, ignoring the thermally-induced preloading deformations that accompany cool-down results in load-induced deformations that are under predicted; and (5) The support conditions strongly influence the response but the influence of the sense of asymmetry and the influence of the thermally-induced preloading deformations are independent of the support conditions.

  12. Report on the status of linear drive coolers for the Department of Defense Standard Advanced Dewar Assembly (SADA)

    NASA Astrophysics Data System (ADS)

    Salazar, William

    2003-01-01

    The Standard Advanced Dewar Assembly (SADA) is the critical module in the Department of Defense (DoD) standardization effort of scanning second-generation thermal imaging systems. DoD has established a family of SADA's to address requirements for high performance (SADA I), mid-to-high performance (SADA II), and compact class (SADA III) systems. SADA's consist of the Infrared Focal Plane Array (IRFPA), Dewar, Command and Control Electronics (C&CE), and the cryogenic cooler. SADA's are used in weapons systems such as Comanche and Apache helicopters, the M1 Abrams Tank, the M2 Bradley Fighting Vehicle, the Line of Sight Antitank (LOSAT) system, the Improved Target Acquisition System (ITAS), and Javelin's Command Launch Unit (CLU). DOD has defined a family of tactical linear drive coolers in support of the family of SADA's. The Stirling linear drive cryo-coolers are utilized to cool the SADA's Infrared Focal Plane Arrays (IRFPAs) to their operating cryogenic temperatures. These linear drive coolers are required to meet strict cool-down time requirements along with lower vibration output, lower audible noise, and higher reliability than currently fielded rotary coolers. This paper will (1) outline the characteristics of each cooler, (2) present the status and results of qualification tests, and (3) present the status and test results of efforts to increase linear drive cooler reliability.

  13. A Study with Computer-Based Circulation Data of the Non-Use and Use of a Large Academic Library. Final Report.

    ERIC Educational Resources Information Center

    Lubans, John, Jr.; And Others

    Computer-based circulation systems, it is widely believed, can be utilized to provide data for library use studies. The study described in this report involves using such a data base to analyze aspects of library use and non-use and types of users. Another major objective of this research was the testing of machine-readable circulation data…

  14. A model for metastable magnetism in the hidden-order phase of URu2Si2

    NASA Astrophysics Data System (ADS)

    Boyer, Lance; Yakovenko, Victor M.

    2018-01-01

    We propose an explanation for the experiment by Schemm et al. (2015) where the polar Kerr effect (PKE), indicating time-reversal symmetry (TRS) breaking, was observed in the hidden-order (HO) phase of URu2Si2. The PKE signal on warmup was seen only if a training magnetic field was present on cool-down. Using a Ginzburg-Landau model for a complex order parameter, we show that the system can have a metastable ferromagnetic state producing the PKE, even if the HO ground state respects TRS. We predict that a strong reversed magnetic field should reset the PKE to zero.

  15. Low cost microminiature refrigerators for large unit volume applications

    NASA Technical Reports Server (NTRS)

    Duboc, R. M., Jr.

    1983-01-01

    Photolithographic techniques were employed to fabricate small Joule-Thomson refrigerators in laminated substrates. The gas passages of a J-T refrigerator are formed by etching channels as narrow as 50 microns and as shallow as 5 microns in glass plates which are laminated together. Circular refrigerators on the order of 1.5 centimeters in diameter and .75 millimeters thick were produced which cool down to cryogenic temperatures in a few seconds, using Argon or Nitrogen, with no vacuum or radiation insulation. Smaller refrigerators are developed for both faster cooldown and low refrigeration capacity applications. By using this technology, custom refrigerators can be designed to meet specific application requirements.

  16. Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

    NASA Technical Reports Server (NTRS)

    Chervenak, J. A.; Adams, J. A.; Bandler, S. B.; Busch, S. E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, J. P.; hide

    2012-01-01

    We have produced a variety of superconducting transition edge sensor array designs for microcalorimetric detection of x-rays. Arrays are characterized with a time division SQUID multiplexer such that greater than 10 devices from an array can be measured in the same cooldown. Designs include kilo pixel scale arrays of relatively small sensors (-75 micron pitch) atop a thick metal heatsinking layer as well as arrays of membrane-isolated devices on 250 micron and up to 600 micron pitch. We discuss fabrication and performance of microstripline wiring at the small scales achieved to date. We also address fabrication issues with reduction of absorber contact area in small devices.

  17. A Solid Nitrogen Cooled MgB2 “Demonstration” Coil for MRI Applications

    PubMed Central

    Yao, Weijun; Bascuñán, Juan; Kim, Woo-Seok; Hahn, Seungyong; Lee, Haigun; Iwasa, Yukikazu

    2009-01-01

    A 700-mm bore superconducting magnet was built and operated in our laboratory to demonstrate the feasibility of newly developed MgB2 superconductor wire for fabricating MRI magnets. The magnet, an assembly of 10 coils each wound with a reacted and s-glass insulated wire ~1-km long, was immersed in solid nitrogen rather than in a bath of liquid cryogen. This MgB2 magnet was designed to operate in the temperature range 10–15 K, maintained by a cryocooler. A combination of this “wide” temperature range and immersion of the winding in solid nitrogen enables this magnet to operate under conditions not possible with a low temperature superconductor (LTS) counterpart. Tested individually at 13 K, each coil could carry current up to 100 A. When assembled into the magnet, some coils, however, became resistive, causing the magnet to prematurely quench at currents ranging from 79 A to 88 A, at which point the magnet generated a center field of 0.54 T. Despite the presence of a large volume (50 liters) of solid nitrogen in the cold body, cooldown from 77 K to 10 K went smoothly. PMID:20390056

  18. Design, fabrication and test of a hydrogen heat pipe. [extruding and grooving 6063-T6 aluminum tubes for cryogenic heat pipes

    NASA Technical Reports Server (NTRS)

    Alario, J.

    1979-01-01

    Re-entrant groove technology was extended to hydrogen heat pipes. Parametric analyses are presented which optimize the theoretical design while considering the limitations of state-of-the-art extrusion technology. The 6063-T6 aluminum extrusion is 14.6 mm OD with a wall thickness of 1.66 mm and contains 20 axial grooves which surround a central 9.3 mm diameter vapor core. Each axial groove is 0.775 mm diameter with a 0.33 mm opening. An excess vapor reservoir is provided at the evaporator to minimize the pressure containment hazard during ambient storage. Modifications to the basic re-entrant groove profile resulted in improved overall performance. While the maximum heat transport capacity decreased slightly to 103 w-m the static wicking height increased markedly to 4.5 cm. The heat pipe became operational between 20 and 30 K after a cooldown from 77 K without any difficulty. Steady state performance data taken over a 19 to 23 K temperature range indicated: (1) maximum heat transport capacity of 5.4 w-m; (2) static wicking height of 1.42 cm; and (3) overall heat pipe conductance of 1.7 watts/deg C.

  19. Modeling and design of a high efficiency hybrid heat pump clothes dryer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    TeGrotenhuis, Ward; Butterfield, Andrew; Caldwell, Dustin

    Computational modeling is used to design a hybrid heat pump clothes dryer capable of saving 50% of the energy used by residential clothes dryers with comparable drying times. The model represents the various stages of a drying cycle from warm-up through constant drying rate and falling drying rate phases and finishing with a cooldown phase. The model is fit to data acquired from a U.S. commercial standard vented electric dryer, and when a hybrid heat pump system is added, the energy factor increases from 3.0 lbs/kWh to 5.7-6.0 lbs/kWh, depending on the increase in blower motor power. The hybrid heatmore » pump system is designed from off-the-shelf components and includes a recuperative heat exchanger, an electric element, and an R-134a vapor compression heat pump. Parametric studies of element power and heating element use show a trade-off between energy savings and cycle time. Results show a step-change in energy savings from heat pump dryers currently marketed in the U.S. based on performance represented by Enery Star from standardized DOE testing.« less

  20. Effects of 8-week Pilates exercise program on menopausal symptoms and lumbar strength and flexibility in postmenopausal women

    PubMed Central

    Lee, Haelim; Caguicla, Joy Matthew Cuasay; Park, Sangseo; Kwak, Dong Jick; Won, Deuk-Yeon; Park, Yunjin; Kim, Jeeyoun; Kim, Myungki

    2016-01-01

    The aim of this study was to investigate the effects of an 8-week Pilates exercise program on menopausal symptoms and lumbar strength and flexibility in postmenopausal women. In total, 74 postmenopausal women were recruited and randomly allocated to a Pilates exercise group (n=45) and a control group (n=29). Menopausal symptoms were measured through a questionnaire, while lumbar strength was measured through a lumbar extension machine, and lumbar flexibility was measured through sit-and-reach and trunk lift tests performed before and after the Pilates exercise program, respectively. The Pilates exercises consisted of 7–10 min for warm-up, 35–40 min for the main program modified from Pilates Academy International, and 5–7 min for the cool-down, and were performed 3 times a week for 8 weeks. The results showed a significant decrease in menopausal symptoms except urogenital symptoms. Also, the results presented a significant increase in lumbar strength and flexibility after 8 weeks of the Pilates exercise program. We concluded that an 8-week Pilates exercise program is effective in decreasing menopausal symptoms and increasing lumbar strength and flexibility. PMID:27419122

  1. Effects of 8-week Pilates exercise program on menopausal symptoms and lumbar strength and flexibility in postmenopausal women.

    PubMed

    Lee, Haelim; Caguicla, Joy Matthew Cuasay; Park, Sangseo; Kwak, Dong Jick; Won, Deuk-Yeon; Park, Yunjin; Kim, Jeeyoun; Kim, Myungki

    2016-06-01

    The aim of this study was to investigate the effects of an 8-week Pilates exercise program on menopausal symptoms and lumbar strength and flexibility in postmenopausal women. In total, 74 postmenopausal women were recruited and randomly allocated to a Pilates exercise group (n=45) and a control group (n=29). Menopausal symptoms were measured through a questionnaire, while lumbar strength was measured through a lumbar extension machine, and lumbar flexibility was measured through sit-and-reach and trunk lift tests performed before and after the Pilates exercise program, respectively. The Pilates exercises consisted of 7-10 min for warm-up, 35-40 min for the main program modified from Pilates Academy International, and 5-7 min for the cool-down, and were performed 3 times a week for 8 weeks. The results showed a significant decrease in menopausal symptoms except urogenital symptoms. Also, the results presented a significant increase in lumbar strength and flexibility after 8 weeks of the Pilates exercise program. We concluded that an 8-week Pilates exercise program is effective in decreasing menopausal symptoms and increasing lumbar strength and flexibility.

  2. Laboratory Surveillance of Rabies in Humans, Domestic Animals, and Bats in Madagascar from 2005 to 2010

    PubMed Central

    Reynes, Jean-Marc; Andriamandimby, Soa Fy; Razafitrimo, Girard Marcelin; Razainirina, Josette; Jeanmaire, Elisabeth Marie; Bourhy, Hervé; Heraud, Jean-Michel

    2011-01-01

    Background. Rabies virus (RABV) has circulated in Madagascar at least since the 19th century. Objectives. To assess the circulation of lyssavirus in the island from 2005 to 2010. Materials and Methods. Animal (including bats) and human samples were tested for RABV and other lyssavirus using antigen, ribonucleic acid (RNA), and antibodies detection and virus isolation. Results. Half of the 437 domestic or tame wild terrestrial mammal brains tested were found RABV antigen positive, including 54% of the 341 dogs tested. This percentage ranged from 26% to 75% across the period. Nine of the 10 suspected human cases tested were laboratory confirmed. RABV circulation was confirmed in 34 of the 38 districts sampled. No lyssavirus RNA was detected in 1983 bats specimens. Nevertheless, antibodies against Lagos bat virus were detected in the sera of 12 among 50 Eidolon dupreanum specimens sampled. Conclusion. More than a century after the introduction of the vaccine, rabies still remains endemic in Madagascar. PMID:21991442

  3. Themes on circulation in the third world.

    PubMed

    Chapman, M; Prothero, R M

    1983-01-01

    "This article focuses upon circulation, or reciprocal flows of people, with specific reference to Third World societies." Aspects considered include attempts to standardize terminology and to formulate typologies of population movement; the development of explanatory models of circulation and modernization, social networks, family welfare, and capitalism; and "the transfer of methods and concepts to societies and populations different from those from which they initially evolved and in which they were first tested." excerpt

  4. The Effect of Cathode Composition on the Thermal Characteristics of Lithium-Ion Cells

    NASA Technical Reports Server (NTRS)

    Vaidyanathan, Hari; Rao, Gopalakrishna M.

    1999-01-01

    The specific thermal capacity and heat dissipation rate for lithium ion cells containing LiNiO2 and mixed oxide (75%LiCoO2+ 25%LiNiO2) as cathode materials are compared. The experimental measurements were made using a radiative calorimeter consisting of a copper chamber maintained at -168 C by circulating liquid nitrogen and enclosed in a vacuum bell jar. The specific thermal capacity was determined based on warm-up and cool-down transients. The heat dissipation rate was calculated from the values measured for heat radiated and stored, and the resulting values were corrected for conductive heat dissipation through the leads. The specific heat was 1.117 J/ C-g for the LiNiO2 cell and 0.946 J/ C-g for the 75%LiCoO2,25%LiNiO2 cell. Endothermic cooling at the beginning of charge was very apparent for the cell containing 75%LiCoO2,25%LiNiO2 as the cathode. Exothermic heating began at a higher state of charge for the cell with the 75%LiCoO2,25%LiNiO2 cathode compared to the LiNiO2 cathode cell. During discharge, the rate of heat dissipation increased with increase in the discharge current for both types of cells. The maximum heat dissipated at C/5 discharge was 0.065 W and 0.04 W for the LiNiO2 and 75%LiCoO2,25%LiNiO2 cells, respectively, The thermoneutral potential showed variability toward the end of discharge. The plateau region of the curves was used to calculate average thermoneutral potentials of 3.698 V and 3.837 V for the LiNiO2 cell and the 75%LiCoO2,25%LiNiO2 cell, respectively.

  5. High performance millimeter-wave microstrip circulators and isolators

    NASA Technical Reports Server (NTRS)

    Shih, Ming; Pan, J. J.

    1990-01-01

    Millimeter wave systems, phased array antennas, and high performance components all require wideband circulators (and isolators) to perform diplexing and switching, to improve isolation and Voltage Standing Wave Ratio (VSWR), and to construct IMPATT diode reflection amplifiers. Presently, most of the millimeter-wave circulators and isolators are available in the configurations of waveguide or stripline, both of which suffer from the shortcomings of bulky size/weight, narrow bandwidth, and poor compatibility with monolithic millimeter-wave integrated circuits (MMIC). MMW microstrip circulators/isolators can eliminate or improve these shortcomings. Stub-tuned microstrip circulator configuration were developed utilizing the electromagnetic fields perturbation technique, the adhesion problems of microstrip metallization on new ferrite substrate were overcome, the fabrication, assembly, packaging techniques were improved, and then successfully designed, fabricated a Ka band circulator which has isolation and return loss of greater than 16dB, insertion loss less than 0.7dB. To assess the steady and reliable performance of the circulator, a temperature cycling test was done over the range of -20 to +50 C for 3 continuous cycles and found no significant impact or variation of circulator performance.

  6. Calibrating the ECCO ocean general circulation model using Green's functions

    NASA Technical Reports Server (NTRS)

    Menemenlis, D.; Fu, L. L.; Lee, T.; Fukumori, I.

    2002-01-01

    Green's functions provide a simple, yet effective, method to test and calibrate General-Circulation-Model(GCM) parameterizations, to study and quantify model and data errors, to correct model biases and trends, and to blend estimates from different solutions and data products.

  7. First Cryo-Vacuum Test of the JWST Integrated Science Instrument Module

    NASA Astrophysics Data System (ADS)

    Kimble, Randy A.; Antonille, S. R.; Balzano, V.; Comber, B. J.; Davila, P. S.; Drury, M. D.; Glasse, A.; Glazer, S. D.; Lundquist, R.; Mann, S. D.; McGuffey, D. B.; Novo-Gradac, K. J.; Penanen, K.; Ramey, D. D.; Sullivan, J.; Van Campen, J.; Vila, M. B.

    2014-01-01

    The integration and test program for the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) calls for three cryo-vacuum tests of the ISIM hardware. The first is a risk-reduction test aimed at checking out the test hardware and procedures; this will be followed by two formal verification tests that will bracket other key aspects of the environmental test program (e.g. vibration and acoustics, EMI/EMC). The first of these cryo-vacuum tests, the risk-reduction test, was executed at NASA’s Goddard Space Flight Center starting in late August, 2013. Flight hardware under test included two (of the eventual four) flight instruments, the Mid-Infrared Instrument (MIRI) and the Fine Guidance Sensor/Near-Infrared Imager and Slitless Spectrograph (FGS/NIRISS), mounted to the ISIM structure, as well as the ISIM Electronics Compartment (IEC). The instruments were cooled to their flight operating temperatures 40K for FGS/NIRISS, ~6K for MIRI) and optically tested against a cryo-certified telescope simulator. Key goals for the risk reduction test included: 1) demonstration of controlled cooldown and warmup, stable control at operating temperature, and measurement of heat loads, 2) operation of the science instruments with ISIM electronics systems at temperature, 3) health trending of the science instruments against instrument-level test results, 4) measurement of the pupil positions and six degree of freedom alignment of the science instruments against the simulated telescope focal surface, 5) detailed optical characterization of the NIRISS instrument, 6) verification of the signal-to-noise performance of the MIRI, and 7) exercise of the Onboard Script System that will be used to operate the instruments in flight. In addition, the execution of the test is expected to yield invaluable logistical experience - development and execution of procedures, communications, analysis of results - that will greatly benefit the subsequent verification tests. At the time of this submission, the hardware had reached operating temperature and was partway through the cryo test program. We report here on the test configuration, the overall process, and the results that were ultimately obtained.

  8. Structural coloration signals condition, parental investment, and circulating hormone levels in Eastern bluebirds (Sialia sialis).

    PubMed

    Grindstaff, Jennifer L; Lovern, Matthew B; Burtka, Jennifer L; Hallmark-Sharber, Alesia

    2012-08-01

    Many of the brilliant plumage coloration displays of birds function as signals to conspecifics. One species in which the function of plumage ornaments has been assessed is the Eastern bluebird (Sialia sialis). Studies of a population breeding in Alabama (USA) have established that plumage ornaments signal quality, parental investment, and competitive ability in both sexes. Here we tested the additional hypotheses that (1) Eastern bluebird plumage ornamentation signals nest defense behavior in heterospecific competitive interactions and (2) individual variation in plumage ornamentation reflects underlying differences in circulating hormone levels. We also tested the potential for plumage ornaments to signal individual quality and parental investment in a population breeding in Oklahoma (USA). We found that Eastern bluebirds with more ornamented plumage are in better condition, initiate breeding earlier in the season, produce larger clutches, have higher circulating levels of the stress hormone corticosterone, and more ornamented males have lower circulating androgen levels. Plumage coloration was not related to nest defense behavior. Thus, plumage ornamentation may be used by both sexes to assess the physiological condition and parental investment of prospective mates. Experimental manipulations of circulating hormone levels during molt are needed to define the role of hormones in plumage ornamentation.

  9. SASSYS pretest analysis of the THORS-SHRS experiments. [LMFBR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bordner, G.L.; Dunn, F.E.

    The THORS Facility at ORNL was recently modified to allow the testing of two parallel 19-pin simulated fueled subassemblies under natural circulation conditions similar to those that might occur during a partial failure of the shutdown heat removal system (SHRS) of a liquid-metal fast breeder reactor. The planned experimental program included a series of tests at various inlet plenum temperatures to determine boiling threshold power levels and the power range for stable boiling during natural circulation operation. Pretest calculations were performed at ANL, which supplement those carried out at ORNL for the purposes of validating the SASSYS model in themore » natural circulation regime and of providing data which would be useful in planning the experiments.« less

  10. Performance of Control System Using Microcontroller for Sea Water Circulation

    NASA Astrophysics Data System (ADS)

    Indriani, A.; Witanto, Y.; Pratama, A. S.; Supriyadi; Hendra; Tanjung, A.

    2018-02-01

    Now a day control system is very important rule for any process. Control system have been used in the automatic system. Automatic system can be seen in the industrial filed, mechanical field, electrical field and etc. In industrial and mechanical field, control system are used for control of motion component such as motor, conveyor, machine, control of process made of product, control of system and soon. In electrical field, control system can met for control of electrical system as equipment or part electrical like fan, rice cooker, refrigerator, air conditioner and etc. Control system are used for control of temperature and circulation gas, air and water. Control system of temperature and circulation of water also can be used for fisher community. Control system can be create by using microcontroller, PLC and other automatic program [1][2]. In this paper we will focus on the close loop system by using microcontroller Arduino Mega to control of temperature and circulation of sea water for fisher community. Performance control system is influenced by control equipment, sensor sensitivity, test condition, environment and others. The temperature sensor is measured using the DS18S20 and the sea water clarity sensor for circulation indicator with turbidity sensor. From the test results indicated that this control system can circulate sea water and maintain the temperature and clarity of seawater in a short time.

  11. Tungsten and beryllium armour development for the JET ITER-like wall project

    NASA Astrophysics Data System (ADS)

    Maier, H.; Hirai, T.; Rubel, M.; Neu, R.; Mertens, Ph.; Greuner, H.; Hopf, Ch.; Matthews, G. F.; Neubauer, O.; Piazza, G.; Gauthier, E.; Likonen, J.; Mitteau, R.; Maddaluno, G.; Riccardi, B.; Philipps, V.; Ruset, C.; Lungu, C. P.; Uytdenhouwen, I.; EFDA contributors, JET

    2007-03-01

    For the ITER-like wall project at JET the present main chamber CFC tiles will be exchanged with Be tiles and in parallel a fully tungsten-clad divertor will be prepared. Therefore three R&D programmes were initiated: Be coatings on Inconel as well as Be erosion markers were developed for the first wall of the main chamber. High heat flux screening and cyclic loading tests carried out on the Be coatings on Inconel showed excellent performance, above the required power and energy density. For the divertor a conceptual design for a bulk W horizontal target plate was investigated, with the emphasis on minimizing electromagnetic forces. The design consisted of stacks of W lamellae of 6 mm width that were insulated in the toroidal direction. High heat flux tests of a test module were performed with an electron beam at an absorbed power density up to 9 MW m-2 for more than 150 pulses and finally with increasing power loads leading to surface temperatures in excess of 3000 °C. No macroscopic failure occurred during the test while SEM showed the development of micro-cracks on the loaded surface. For all other divertor parts R&D was performed to provide the technology to coat the 2-directional CFC material used at JET with thin tungsten coatings. The W-coated CFC tiles were subjected to heat loads with power densities ranging up to 23.5 MW m-2 and exposed to cyclic heat loading for 200 pulses at 10.5 MW m-2. All coatings developed cracks perpendicular to the CFC fibres due to the stronger contraction of the coating upon cool-down after the heat pulses.

  12. Circulating microRNA as candidates for early embryonic viability in cattle

    USDA-ARS?s Scientific Manuscript database

    Blood borne extracellular vesicles (EVs; i.e. exosomes and microvesicles) carrying microRNA (miRNA) may make excellent biomarkers of disease conditions and different physiologic states, including pregnancy status. We tested the hypothesis that circulating EV-derived miRNA might differentiate pregnan...

  13. Thermal Vacuum Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin

    2016-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and to verify its ability to cool large areas or components in the 3 degrees Kelvin temperature range. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully by simply applying power to both the capillary pump and the evaporator plate without pre-conditioning. It could adapt to a rapid heat load change and quickly reach a new steady state. Heat removal between 10 megawatts and 140 megawatts was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  14. Tests of Parameterized Langmuir Circulation Mixing in the Oceans Surface Mixed Layer II

    DTIC Science & Technology

    2017-08-11

    inertial oscillations in the ocean are governed by three-dimensional processes that are not accounted for in a one-dimensional simulation , and it was...Unlimited 52 Paul Martin (228) 688-5447 Recent large-eddy simulations (LES) of Langmuir circulation (LC) within the surface mixed layer (SML) of...used in the Navy Coastal Ocean Model (NCOM) and tested for (a) a simple wind-mixing case, (b) simulations of the upper ocean thermal structure at Ocean

  15. Development of a Cryogenic Thermal Distortion Measurement Facility for Testing the James Webb Space Telescope Instrument Support Integration Module 2-D Test Assemblies

    NASA Technical Reports Server (NTRS)

    Miller, Franklin; Bagdanove, paul; Blake, Peter; Canavan, Ed; Cofie, Emmanuel; Crane, J. Allen; Dominquez, Kareny; Hagopian, John; Johnston, John; Madison, Tim; hide

    2007-01-01

    The James Webb Space Telescope Instrument Support Integration Module (ISIM) is being designed and developed at the Goddard Space Flight Center. The ISM Thermal Distortion Testing (ITDT) program was started with the primary objective to validate the ISM mechanical design process. The ITDT effort seeks to establish confidence and demonstrate the ability to predict thermal distortion in composite structures at cryogenic temperatures using solid element models. This-program's goal is to better ensure that ISIM meets all the mechanical and structural requirements by using test results to verify or improve structural modeling techniques. The first step to accomplish the ITDT objectives was to design, and then construct solid element models of a series 2-D test assemblies that represent critical building blocks of the ISIM structure. Second, the actual test assemblies consisting of composite tubes and invar end fittings were fabricated and tested for thermal distortion. This paper presents the development of the GSFC Cryo Distortion Measurement Facility (CDMF) to meet the requirements of the ISIM 2-D test. assemblies, and other future ISIM testing needs. The CDMF provides efficient cooling with both a single, and two-stage cryo-cooler. Temperature uniformity of the test assemblies during thermal transients and at steady state is accomplished by using sapphire windows for all of the optical ports on the radiation shields and by using .thermal straps to cool the test assemblies. Numerical thermal models of the test assemblies were used to predict the temperature uniformity of the parts during cooldown and at steady state. Results of these models are compared to actual temperature data from the tests. Temperature sensors with a 0.25K precision were used to insure that test assembly gradients did not exceed 2K lateral, and 4K axially. The thermal distortions of two assemblies were measured during six thermal cycles from 320K to 35K using laser interferometers. The standard deviation for all of the distortion measurements is less than 0.5 microns, which falls within the ISIM requirement of 3 microns.

  16. Using Time-Series Regression to Predict Academic Library Circulations.

    ERIC Educational Resources Information Center

    Brooks, Terrence A.

    1984-01-01

    Four methods were used to forecast monthly circulation totals in 15 midwestern academic libraries: dummy time-series regression, lagged time-series regression, simple average (straight-line forecasting), monthly average (naive forecasting). In tests of forecasting accuracy, dummy regression method and monthly mean method exhibited smallest average…

  17. A Wind Tunnel Model to Explore Unsteady Circulation Control for General Aviation Applications

    NASA Technical Reports Server (NTRS)

    Cagle, Christopher M.; Jones, Gregory S.

    2002-01-01

    Circulation Control airfoils have been demonstrated to provide substantial improvements in lift over conventional airfoils. The General Aviation Circular Control model is an attempt to address some of the concerns of this technique. The primary focus is to substantially reduce the amount of air mass flow by implementing unsteady flow. This paper describes a wind tunnel model that implements unsteady circulation control by pulsing internal pneumatic valves and details some preliminary results from the first test entry.

  18. Genetically elevated levels of circulating triglycerides and brachial-ankle pulse wave velocity in a Chinese population.

    PubMed

    Yao, W-M; Zhang, H-F; Zhu, Z-Y; Zhou, Y-L; Liang, N-X; Xu, D-J; Zhou, F; Sheng, Y-H; Yang, R; Gong, L; Yin, Z-J; Chen, F-K; Cao, K-J; Li, X-L

    2013-04-01

    Elevated levels of circulating triglycerides and increased arterial stiffness are associated with cardiovascular disease. Numerous studies have reported an association between levels of circulating triglycerides and arterial stiffness. We used Mendelian randomization to test whether this association is causal. We investigated the association between circulating triglyceride levels, the apolipoprotein A-V (ApoA5) -1131T>C single nucleotide polymorphism and brachial-ankle pulse wave velocity (baPWV) by examining data from 4421 subjects aged 18-74 years who were recruited from the Chinese population. baPWV was significantly associated with the levels of circulating triglycerides after adjusting for age, sex, body mass index (BMI), systolic blood pressure, heart rate, waist-to-hip ratio, antihypertensive treatment and diabetes mellitus status. The -1131C allele was associated with a 5% (95% confidence interval 3-8%) increase in circulating triglycerides (adjusted for age, sex, BMI, waist-to-hip ratio, diabetes mellitus and antihypertensive treatment). Instrumental variable analysis showed that genetically elevated levels of circulating triglycerides were not associated with increased baPWV. These results do not support the hypothesis that levels of circulating triglycerides have a causal role in the development of arterial stiffness.

  19. Liquefied Natural Gas Transfer

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Chicago Bridge & Iron Company's tanks and associated piping are parts of system for transferring liquefied natural gas from ship to shore and storing it. LNG is a "cryogenic" fluid meaning that it must be contained and transferred at very low temperatures, about 260 degrees below Fahrenheit. Before the LNG can be pumped from the ship to the storage tanks, the two foot diameter transfer pipes must be cooled in order to avoid difficulties associated with sharp differences of temperature between the supercold fluid and relatively warm pipes. Cooldown is accomplished by sending small steady flow of the cryogenic substance through the pipeline; the rate of flow must be precisely controlled or the transfer line will be subjected to undesirable thermal stress.

  20. Modeling heat and moisture transport in firefighter protective clothing during flash fire exposure

    NASA Astrophysics Data System (ADS)

    Chitrphiromsri, Patirop; Kuznetsov, Andrey V.

    2005-01-01

    In this paper, a model of heat and moisture transport in firefighter protective clothing during a flash fire exposure is presented. The aim of this study is to investigate the effect of coupled heat and moisture transport on the protective performance of the garment. Computational results show the distribution of temperature and moisture content in the fabric during the exposure to the flash fire as well as during the cool-down period. Moreover, the duration of the exposure during which the garment protects the firefighter from getting second and third degree burns from the flash fire exposure is numerically predicted. A complete model for the fire-fabric-air gap-skin system is presented.

  1. Using mechanobiological mimicry of red blood cells to extend circulation times of hydrogel microparticles

    PubMed Central

    Merkel, Timothy J.; Jones, Stephen W.; Herlihy, Kevin P.; Kersey, Farrell R.; Shields, Adam R.; Napier, Mary; Luft, J. Christopher; Wu, Huali; Zamboni, William C.; Wang, Andrew Z.; Bear, James E.; DeSimone, Joseph M.

    2011-01-01

    It has long been hypothesized that elastic modulus governs the biodistribution and circulation times of particles and cells in blood; however, this notion has never been rigorously tested. We synthesized hydrogel microparticles with tunable elasticity in the physiological range, which resemble red blood cells in size and shape, and tested their behavior in vivo. Decreasing the modulus of these particles altered their biodistribution properties, allowing them to bypass several organs, such as the lung, that entrapped their more rigid counterparts, resulting in increasingly longer circulation times well past those of conventional microparticles. An 8-fold decrease in hydrogel modulus correlated to a greater than 30-fold increase in the elimination phase half-life for these particles. These results demonstrate a critical design parameter for hydrogel microparticles. PMID:21220299

  2. Evidence of Schmallenberg virus circulation in ruminants in Greece.

    PubMed

    Chaintoutis, Serafeim C; Kiossis, Evangelos; Giadinis, Nektarios D; Brozos, Christos N; Sailleau, Corinne; Viarouge, Cyril; Bréard, Emmanuel; Papanastassopoulou, Maria; Zientara, Stéphan; Papadopoulos, Orestis; Dovas, Chrysostomos I

    2014-01-01

    During March 2013, we investigated the presence and the levels of Schmallenberg virus (SBV) circulation in three dairy cow herds and three sheep flocks in Central Macedonia, Greece. In two cow herds, a high number of abortions had been observed during the winter. Six bulk-tank milk samples and 147 individual sera were screened for SBV-specific antibodies by ELISA. Positive reactions were obtained from 5 out of 6 bulk-tank milk samples, 58 out of 90 sera from the 3 cow herds, and 2 sera from 2 of the 3 sheep flocks. Twenty-two ELISA-positive sera were tested by serum neutralization test (SNT). SNT confirmed the presence of neutralizing antibodies against SBV in all samples tested, with titers ranging between 1:32 and ≥1:256. No neutralizing antibodies against Akabane virus (AKAV) or Shamonda virus (SHAV) were detected, indicating that neutralizing antibodies against SBV do not cross react with AKAV or SHAV in SNT. ELISA testing of bulk-tank milk samples proved to be convenient and reliable. None of the tested sera was found positive for SBV by real-time RT-PCR, indicating that the sampling was conducted past the viremia stage. This is the first report of SBV circulation in Greece.

  3. Study of lubricant circulation in HVAC systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Biancardi, F.; Sienel, T.; Pandy, D.

    1997-02-01

    This program was aimed at understanding refrigerant/lubricant circulation issues, developing test data and approximate models that can predict operating regimes where good oil management can be assured. A dynamic test facility was constructed and used to examine oil return under varying system operating conditions. The development of industry guidelines for system reliability in using the new refrigerant blends was a goal of this program. To validate the guidelines, techniques and predictions, this dynamic test facility was used to obtain data to compare to the analytical predictions. The overall program approach undertaken to meet this objective was: (1) to identify poormore » oil return scenarios and, therefore, the worst case oil return parameters for conventional residential HVAC systems using HCFC-22 and mineral oils, in terms of compressor, suction and exhaust line vapor velocity, and refrigerant viscosity requirements; (2) design and instrument a test apparatus that simulates such conditions, as well as those that might be achieved with HFC and POE mixtures and HFCs and mineral oils; (3) conduct tests with the range of baseline refrigerants and lubricant mixtures to provide experimental data; and (4) prepare, present and interpret the test data to provide an expanded understanding of the phenomena required for good oil circulation in split-system heat pump systems. To convert this general approach into the program specifics, three major tasks were defined and pursued. These are described briefly here and in greater detail in the report body as Task 1, Task 2, and Task 3. The report prepared for ARTI as part of the MCLR Project Number 665-53100 is described in Volumes 1 and 2, ``Study of Lubricant Circulation in the HVAC Systems,`` October 1996, from the same authors as this publication. This record consists of the overheads used in the presentation.« less

  4. Flaviviruses in Europe: Complex Circulation Patterns and Their Consequences for the Diagnosis and Control of West Nile Disease

    PubMed Central

    Beck, Cécile; Jimenez-Clavero, Miguel Angel; Leblond, Agnès; Durand, Benoît; Nowotny, Norbert; Leparc-Goffart, Isabelle; Zientara, Stéphan; Jourdain, Elsa; Lecollinet, Sylvie

    2013-01-01

    In Europe, many flaviviruses are endemic (West Nile, Usutu, tick-borne encephalitis viruses) or occasionally imported (dengue, yellow fever viruses). Due to the temporal and geographical co-circulation of flaviviruses in Europe, flavivirus differentiation by diagnostic tests is crucial in the adaptation of surveillance and control efforts. Serological diagnosis of flavivirus infections is complicated by the antigenic similarities among the Flavivirus genus. Indeed, most flavivirus antibodies are directed against the highly immunogenic envelope protein, which contains both flavivirus cross-reactive and virus-specific epitopes. Serological assay results should thus be interpreted with care and confirmed by comparative neutralization tests using a panel of viruses known to circulate in Europe. However, antibody cross-reactivity could be advantageous in efforts to control emerging flaviviruses because it ensures partial cross-protection. In contrast, it might also facilitate subsequent diseases, through a phenomenon called antibody-dependent enhancement mainly described for dengue virus infections. Here, we review the serological methods commonly used in WNV diagnosis and surveillance in Europe. By examining past and current epidemiological situations in different European countries, we present the challenges involved in interpreting flavivirus serological tests and setting up appropriate surveillance programs; we also address the consequences of flavivirus circulation and vaccination for host immunity. PMID:24225644

  5. Transonic Drag Reduction Through Trailing-Edge Blowing on the FAST-MAC Circulation Control Model

    NASA Technical Reports Server (NTRS)

    Chan, David T.; Jones, Gregory S.; Milholen, William E., II; Goodliff, Scott L.

    2017-01-01

    A third wind tunnel test of the FAST-MAC circulation control semi-span model was completed in the National Transonic Facility at the NASA Langley Research Center where the model was configured for transonic testing of the cruise configuration with 0deg flap detection to determine the potential for transonic drag reduction with the circulation control blowing. The model allowed independent control of four circulation control plenums producing a high momentum jet from a blowing slot near the wing trailing edge that was directed over a 15% chord simple-hinged ap. Recent upgrades to transonic semi-span flow control testing at the NTF have demonstrated an improvement to overall data repeatability, particularly for the drag measurement, that allows for increased confidence in the data results. The static thrust generated by the blowing slot was removed from the wind-on data using force and moment balance data from wind-o thrust tares. This paper discusses the impact of the trailing-edge blowing to the transonic aerodynamics of the FAST-MAC model in the cruise configuration, where at flight Reynolds numbers, the thrust-removed corrected data showed that an overall drag reduction and increased aerodynamic efficiency was realized as a consequence of the blowing.

  6. Use of tandem circulation wells to measure hydraulic conductivity without groundwater extraction

    NASA Astrophysics Data System (ADS)

    Goltz, Mark N.; Huang, Junqi; Close, Murray E.; Flintoft, Mark J.; Pang, Liping

    2008-09-01

    Conventional methods to measure the hydraulic conductivity of an aquifer on a relatively large scale (10-100 m) require extraction of significant quantities of groundwater. This can be expensive, and otherwise problematic, when investigating a contaminated aquifer. In this study, innovative approaches that make use of tandem circulation wells to measure hydraulic conductivity are proposed. These approaches measure conductivity on a relatively large scale, but do not require extraction of groundwater. Two basic approaches for using circulation wells to measure hydraulic conductivity are presented; one approach is based upon the dipole-flow test method, while the other approach relies on a tracer test to measure the flow of water between two recirculating wells. The approaches are tested in a relatively homogeneous and isotropic artificial aquifer, where the conductivities measured by both approaches are compared to each other and to the previously measured hydraulic conductivity of the aquifer. It was shown that both approaches have the potential to accurately measure horizontal and vertical hydraulic conductivity for a relatively large subsurface volume without the need to pump groundwater to the surface. Future work is recommended to evaluate the ability of these tandem circulation wells to accurately measure hydraulic conductivity when anisotropy and heterogeneity are greater than in the artificial aquifer used for these studies.

  7. Influenza (Flu) Viruses

    MedlinePlus

    ... UPDATE: Parotitis and Influenza FAQ Parotitis and Influenza Algorithm: Interpreting Influenza Testing Results When Influenza is Circulating Algorithm: Interpreting Influenza Testing Results When Influenza is NOT ...

  8. Fabrication and Characterization of Diffusion Bonds for Silicon Carbide

    NASA Technical Reports Server (NTRS)

    Halbig, Michael; Singh, Mrityunjay; Martin, Richard E.; Cosgriff, Laura M.

    2007-01-01

    Diffusion bonds of silicon carbide (SiC) were fabricated using several different types of titanium (Ti) based interlayers between the SiC substrates. The interlayers were an alloyed Ti foil, a pure Ti foil, and a physically vapor deposited (PVD) Ti coating. Microscopy was conducted to evaluate the cross-sections of the resulting bonds. Microprobe analysis identified reaction formed phases in the diffusion bonded region. Uniform and well adhered bonds were formed between the SiC substrates. In the case where the alloyed Ti foil or a thick Ti coating (i.e. 20 micron) was used as the interlayer, microcracks and several phases were present in the diffusion bonds. When a thinner interlayer was used (i.e. 10 micron PVD Ti), no microcracks were observed and only two reaction formed phases were present. The two phases were preferred and fully reacted phases that did not introduce thermal stresses or microcracks during the cool-down stage after processing. Diffusion bonded samples were evaluated with the non-destructive evaluation (NDE) methods of pulsed thermography and immersion ultrasonic testing. Joined SiC substrates that were fully bonded and that had simulated bond flaws in the interlayer were also evaluated using immersion ultrasound. Pull testing was conducted on the bonds to determine the tensile strength. To demonstrate the joining approach for a complex multilayered component for a low NOx injector application, the diffusion bonding approach was used to join three 4" diameter SiC discs that contained complex fuel and air flow channels.

  9. Co-Production of Electricity and Hydrogen Using a Novel Iron-based Catalyst

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hilaly, Ahmad; Georgas, Adam; Leboreiro, Jose

    2011-09-30

    The primary objective of this project was to develop a hydrogen production technology for gasification applications based on a circulating fluid-bed reactor and an attrition resistant iron catalyst. The work towards achieving this objective consisted of three key activities: Development of an iron-based catalyst suitable for a circulating fluid-bed reactor; Design, construction, and operation of a bench-scale circulating fluid-bed reactor system for hydrogen production; Techno-economic analysis of the steam-iron and the pressure swing adsorption hydrogen production processes. This report describes the work completed in each of these activities during this project. The catalyst development and testing program prepared and iron-basedmore » catalysts using different support and promoters to identify catalysts that had sufficient activity for cyclic reduction with syngas and steam oxidation and attrition resistance to enable use in a circulating fluid-bed reactor system. The best performing catalyst from this catalyst development program was produced by a commercial catalyst toll manufacturer to support the bench-scale testing activities. The reactor testing systems used during material development evaluated catalysts in a single fluid-bed reactor by cycling between reduction with syngas and oxidation with steam. The prototype SIP reactor system (PSRS) consisted of two circulating fluid-bed reactors with the iron catalyst being transferred between the two reactors. This design enabled demonstration of the technical feasibility of the combination of the circulating fluid-bed reactor system and the iron-based catalyst for commercial hydrogen production. The specific activities associated with this bench-scale circulating fluid-bed reactor systems that were completed in this project included design, construction, commissioning, and operation. The experimental portion of this project focused on technical demonstration of the performance of an iron-based catalyst and a circulating fluid-bed reactor system for hydrogen production. Although a technology can be technically feasible, successful commercial deployment also requires that a technology offer an economic advantage over existing commercial technologies. To effective estimate the economics of this steam-iron process, a techno-economic analysis of this steam iron process and a commercial pressure swing adsorption process were completed. The results from this analysis described in this report show the economic potential of the steam iron process for integration with a gasification plant for coproduction of hydrogen and electricity.« less

  10. Design, manufacture, and test of coolant pump-motor assembly for Brayton power conversion system

    NASA Technical Reports Server (NTRS)

    Gabacz, L. E.

    1973-01-01

    The design, development, fabrication, and testing of seven coolant circulating pump-motor assemblies are discussed. The pump-motor assembly is driven by the nominal 44.4-volt, 400-Hz, 3-phase output of a nominal 56-volt dc input inverter. The pump-motor assembly will be used to circulate Dow Corning 200 liquid coolant for use in a Brayton cycle space power system. The pump-motor assembly develops a nominal head of 70 psi at 3.7 gpm with an over-all efficiency of 26 percent. The design description, drawings, photographs, reliability results, and developmental and acceptance test results are included.

  11. Smoothing Forecasting Methods for Academic Library Circulations: An Evaluation and Recommendation.

    ERIC Educational Resources Information Center

    Brooks, Terrence A.; Forys, John W., Jr.

    1986-01-01

    Circulation time-series data from 50 midwest academic libraries were used to test 110 variants of 8 smoothing forecasting methods. Data and methodologies and illustrations of two recommended methods--the single exponential smoothing method and Brown's one-parameter linear exponential smoothing method--are given. Eight references are cited. (EJS)

  12. In Vitro Simulation and Validation of the Circulation with Congenital Heart Defects

    PubMed Central

    Figliola, Richard S.; Giardini, Alessandro; Conover, Tim; Camp, Tiffany A.; Biglino, Giovanni; Chiulli, John; Hsia, Tain-Yen

    2010-01-01

    Despite the recent advances in computational modeling, experimental simulation of the circulation with congenital heart defect using mock flow circuits remains an important tool for device testing, and for detailing the probable flow consequences resulting from surgical and interventional corrections. Validated mock circuits can be applied to qualify the results from novel computational models. New mathematical tools, coupled with advanced clinical imaging methods, allow for improved assessment of experimental circuit performance relative to human function, as well as the potential for patient-specific adaptation. In this review, we address the development of three in vitro mock circuits specific for studies of congenital heart defects. Performance of an in vitro right heart circulation circuit through a series of verification and validation exercises is described, including correlations with animal studies, and quantifying the effects of circuit inertiance on test results. We present our experience in the design of mock circuits suitable for investigations of the characteristics of the Fontan circulation. We use one such mock circuit to evaluate the accuracy of Doppler predictions in the presence of aortic coarctation. PMID:21218147

  13. Circulating miR-423_5p fails as a biomarker for systemic ventricular function in adults after atrial repair for transposition of the great arteries.

    PubMed

    Tutarel, Oktay; Dangwal, Seema; Bretthauer, Julia; Westhoff-Bleck, Mechthild; Roentgen, Philipp; Anker, Stefan D; Bauersachs, Johann; Thum, Thomas

    2013-07-15

    Recently, the microRNA miR-423_5p was identified as a biomarker for left ventricular heart failure. Its role in patients with a systemic right ventricle and reduced ejection fraction after atrial repair for transposition of the great arteries has not been evaluated. In 41 patients and 10 age- and sex-matched healthy controls circulating miR-423_5p concentration was measured and correlated to clinical parameters, cardiac functional parameters assessed by magnetic resonance imaging, and cardiopulmonary exercise testing. Levels of circulating miR-423_5p showed no difference between patients and controls. Further, there was no correlation between miR-423_5p and parameters of cardiopulmonary exercise testing or imaging findings. In patients with a systemic right ventricle and reduced ejection fraction miR-423_5p levels are not elevated. Therefore, circulating miR-423_5p is not a useful biomarker for heart failure in this patient group. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Development of a hydraulic model of the human systemic circulation

    NASA Technical Reports Server (NTRS)

    Sharp, M. K.; Dharmalingham, R. K.

    1999-01-01

    Physical and numeric models of the human circulation are constructed for a number of objectives, including studies and training in physiologic control, interpretation of clinical observations, and testing of prosthetic cardiovascular devices. For many of these purposes it is important to quantitatively validate the dynamic response of the models in terms of the input impedance (Z = oscillatory pressure/oscillatory flow). To address this need, the authors developed an improved physical model. Using a computer study, the authors first identified the configuration of lumped parameter elements in a model of the systemic circulation; the result was a good match with human aortic input impedance with a minimum number of elements. Design, construction, and testing of a hydraulic model analogous to the computer model followed. Numeric results showed that a three element model with two resistors and one compliance produced reasonable matching without undue complication. The subsequent analogous hydraulic model included adjustable resistors incorporating a sliding plate to vary the flow area through a porous material and an adjustable compliance consisting of a variable-volume air chamber. The response of the hydraulic model compared favorably with other circulation models.

  15. Observing a fictitious stressful event: haematological changes, including circulating leukocyte activation.

    PubMed

    Mian, Rubina; Shelton-Rayner, Graham; Harkin, Brendan; Williams, Paul

    2003-03-01

    The aim of this study was to assess the effect of watching a psychological stressful event on the activation of leukocytes in healthy human volunteers. Blood samples were obtained from 32 healthy male and female subjects aged between 20 and 26 years before, during and after either watching an 83-minute horror film that none of the subjects had previously seen (The Texas Chainsaw Massacre, 1974) or by sitting quietly in a room (control group). Total differential cell counts, leukocyte activation as measured by the nitroblue tetrazolium (NBT) test, heart rate and blood pressure (BP) measurements were taken at defined time points. There were significant increases in peripheral circulating leukocytes, the number of activated circulating leukocytes, haemoglobin (Hb) concentration and haematocrit (Hct) in response to the stressor. These were accompanied by significant increases in heart rate, systolic and diastolic BP (P<0.05 from baseline). This is the first reported study on the effects of observing a psychologically stressful, albeit fictitious event on circulating leukocyte numbers and the state of leukocyte activation as determined by the nitrotetrazolium test.

  16. Flu and People with Diabetes

    MedlinePlus

    ... UPDATE: Parotitis and Influenza FAQ Parotitis and Influenza Algorithm: Interpreting Influenza Testing Results When Influenza is Circulating Algorithm: Interpreting Influenza Testing Results When Influenza is NOT ...

  17. The 1997/98 El Nino: A Test for Climate Models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lu, R; Dong, B; Cess, R D

    Version 3 of the Hadley Centre Atmospheric Model (HadAM3) has been used to demonstrate one means of comparing a general circulation model with observations for a specific climate perturbation, namely the strong 1997/98 El Nino. This event was characterized by the collapse of the tropical Pacific's Walker circulation, caused by the lack of a zonal sea surface temperature gradient during the El Nino. Relative to normal years, cloud altitudes were lower in the western portion of the Pacific and higher in the eastern portion. HadAM3 likewise produced the observed collapse of the Walker circulation, and it did a reasonable jobmore » of reproducing the west/east cloud structure changes. This illustrates that the 1997/98 El Nino serves as a useful means of testing cloud-climate interactions in climate models.« less

  18. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System.

    PubMed

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Thus, we can conclude that a simulator system using an extracorporeal circulation system can be set to different models of dialyzers, and that the reproduced treatment scenarios can be used for simulation training.

  19. Seasonal changes in the atmospheric heat balance simulated by the GISS general circulation model

    NASA Technical Reports Server (NTRS)

    Stone, P. H.; Chow, S.; Helfand, H. M.; Quirk, W. J.; Somerville, R. C. J.

    1975-01-01

    Tests of the ability of numerical general circulation models to simulate the atmosphere have focussed so far on simulations of the January climatology. These models generally present boundary conditions such as sea surface temperature, but this does not prevent testing their ability to simulate seasonal changes in atmospheric processes that accompany presented seasonal changes in boundary conditions. Experiments to simulate changes in the zonally averaged heat balance are discussed since many simplified models of climatic processes are based solely on this balance.

  20. Localization of quenches and mechanical disturbances in the Mu2e transport solenoid prototype using acoustic emission technique

    DOE PAGES

    Marchevsky, M.; Ambrosio, G.; Lamm, M.; ...

    2016-02-12

    Acoustic emission (AE) detection is a noninvasive technique allowing the localization of the mechanical events and quenches in superconducting magnets. Application of the AE technique is especially advantageous in situations where magnet integrity can be jeopardized by the use of voltage taps or inductive pickup coils. As the prototype module of the transport solenoid (TS) for the Mu2e experiment at Fermilab represents such a special case, we have developed a dedicated six-channel AE detection system and accompanying software aimed at localizing mechanical events during the coil cold testing. The AE sensors based on transversely polarized piezoceramic washers combined with cryogenicmore » preamplifiers were mounted at the outer surface of the solenoid aluminum shell, with a 60° angular step around the circumference. Acoustic signals were simultaneously acquired at a rate of 500 kS/s, prefiltered and sorted based on their arrival time. Next, based on the arrival timing, angular and axial coordinates of the AE sources within the magnet structure were calculated. Furthermore, we present AE measurement results obtained during cooldown, spot heater firing, and spontaneous quenching of the Mu2e TS module prototype and discuss their relevance for mechanical stability assessment and quench localization.« less

  1. Cross-reactions of sera from dogs infected with Angiostrongylus vasorum in commercially available Dirofilaria immitis test kits.

    PubMed

    Schnyder, Manuela; Deplazes, Peter

    2012-11-13

    Dirofilaria immitis and Angiostrongylus vasorum are both important potentially fatal canine nematodes with overlapping endemic areas, especially in Europe. The preadult and adult stages of both species are living in the Arteria pulmonalis and the right heart, and diagnostically detectable circulating parasite antigens have been demonstrated for both species. For the detection of D. immitis infections, a variety of commercial tests have been developed, however, they have not been evaluated for cross-reactions against circulating antigens of A. vasorum. In this study, potential cross-reactions of sera from 16 dogs, which were experimentally infected with A. vasorum and which had circulating antigens as confirmed by a species-specific ELISA, were evaluated for the detection of A. vasorum antigen in six commercially available D. immitis test kits. In three fast tests (Witness® Dirofilaria, SensPERT® Canine Heartworm, SNAP® 4Dx® Plus), all sera were negative. One fast membrane ELISA (SNAP® HTWM RT Test) was positive with four sera (25%), and one serum delivered a non-valid result twice. In the PetChek® HTWM PF Test, depending on the interpretation protocol, 5 or 8 dogs (31.2 - 50%) were positive. With the DiroCHEK®-ELISA, a single A. vasorum-infected dog (6.2%) tested positive. Due to potential cross-reactions with A. vasorum in commercially available test kits for the detection of D. immitis antigen, the simultaneous use of highly specific diagnostic methods for the differentiation of these two canine heart worms is recommended.

  2. Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin

    2016-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components in the 3K temperature range. A copper plate with attached electrical heaters was used to simulate the heat source, and heat was collected by the CLHP evaporator and transferred to the cryocooler for ultimate heat rejection. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully without pre-conditioning by simply applying power to both the capillary pump and the evaporator plate. It could adapt to rapid changes in the heat load, and reach a new steady state very quickly. Heat removal between 10mW and 140mW was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  3. Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin Lee

    2015-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components in the 3K temperature range. A copper plate with attached electrical heters was used to simulate the heat source, and heat was collected by the CLHP evaporator and transferred to the cryocooler for ultimate heat rejection. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully without pre-conditioning by simply applying power to both the capillary pump and the evaporator plate. It could adapt to rapid changes in the heat load, and reach a new steady state very quickly. Heat removal between 10mW and 140mW was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  4. Flu: What to Do If You Get Sick

    MedlinePlus

    ... UPDATE: Parotitis and Influenza FAQ Parotitis and Influenza Algorithm: Interpreting Influenza Testing Results When Influenza is Circulating Algorithm: Interpreting Influenza Testing Results When Influenza is NOT ...

  5. SPES-2, AP600 intergral system test S01007 2 inch CL to core make-up tank pressure balance line break

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bacchiani, M.; Medich, C.; Rigamonti, M.

    1995-09-01

    The SPES-2 is a full height, full pressure experimental test facility reproducing the Westinghouse AP600 reactor with a scaling factor of 1/395. The experimental plant, designed and operated by SIET in Piacenza, consists of a full simulation of the AP600 primary core cooling system including all the passive and active safety systems. In 1992, Westinghouse, in cooperation with ENEL (Ente Nazionale per l` Energia Elettrica), ENEA (Enter per le numove Technlogie, l` Energia e l` Ambient), Siet (Societa Informazioni Esperienze Termoidraulich) and ANSALDO developed an experimental program to test the integrated behaviour of the AP600 passive safety systems. The SPES-2more » test matrix, concluded in November 1994, has examined the AP600 passive safety system response for a range of small break LOCAs at different locations on the primary system and on the passive system lines; single steam generator tube ruptures with passive and active safety systems and a main steam line break transient to demonstrate the boration capability of passive safety systems for rapid cooldown. Each of the tests has provided detailed experimental results for verification of the capability of the analysis methods to predict the integrated passive safety system behaviour. Cold and hot shakedown tests have been performed on the facility to check the characteristics of the plant before starting the experimental campaign. The paper first presents a description of the SPES-2 test facility then the main results of S01007 test {open_quotes}2{close_quotes} Cold Leg (CL) to Core Make-up Tank (CMT) pressure balance line break{close_quotes} are reported and compared with predictions performed using RELAP5/mod3/80 obtained by ANSALDO through agreement with U.S.N.R.C. (U.S. Nuclear Regulatory Commission). The SPES-2 nodalization and all the calculations here presented were performed by ANSALDO and sponsored by ENEL as a part of pre-test predictions for SPES-2.« less

  6. Comet assay and micronucleus test in circulating erythrocytes of Cyprinus carpio specimens exposed in situ to lake waters treated with disinfectants for potabilization.

    PubMed

    Buschini, A; Martino, A; Gustavino, B; Monfrinotti, M; Poli, P; Rossi, C; Santoro, M; Dörr, A J M; Rizzoni, M

    2004-02-14

    The detection of a possible genotoxic effect of surface water treated with disinfectants for potabilization is the aim of the present work. The Comet assay and the micronucleus test were applied in circulating erythrocytes of Cyprinus carpio. Young specimens (20-30 g) were exposed in experimental basins, built within the potabilization plant of Castiglione del Lago (Perugia, Italy). In this plant the water of the Trasimeno Lake is treated and disinfected for potabilization before it is distributed to the people in the net of drinkable water. A continuous flow of water at a constant rate was supplied to basins; the water was continuously treated at a constant concentration with one of the three tested disinfectants (sodium hypochlorite, peracetic acid and chloride dioxide), one control basin being supplied with untreated water. Three sampling campaigns were performed: October 2000, February 2001 and June 2001. Repeated blood samplings through intracardiac punctures allowed to follow the same fish populations after different exposure times: before introduction of the disinfectant, and 10 or 20 days afterwards. An additional blood sampling was performed 3 h after addition of the disinfectant in other, simultaneously exposed, fish populations. Genotoxic damage was shown in fish exposed to water disinfected with sodium hypochlorite and chloride dioxide. The Comet assay showed an immediate response, i.e. DNA damage that was induced directly in circulating erythrocytes, whereas micronuclei reached their highest frequencies at later sampling times, when a genotoxic damage in stem cells of the cephalic kidney is expressed in circulating erythrocytes. The quality of the untreated surface water seems to be the most important parameter for the long-term DNA damage in circulating erythrocytes.

  7. Widespread circulation of a new echovirus 30 variant causing aseptic meningitis and non-specific viral illness, South-East France, 2013.

    PubMed

    Nougairede, Antoine; Bessaud, Mael; Thiberville, Simon-Djamel; Piorkowski, Geraldine; Ninove, Laetitia; Zandotti, Christine; Charrel, Remi N; Guilhem, Noel; de Lamballerie, Xavier

    2014-09-01

    Human enteroviruses (HEVs) are major cause of aseptic meningitis. A new outbreak of E-30 occurred between April and September 2013 in Marseille, South-East France. Better understand what happen locally when an E-30 outbreak occurs. Laboratory data (identification and characterization of circulating E-30 strains by partial/complete genome sequencing) were analyzed together with clinical data from emergency ward of the public hospital of Marseille. Compared with data from previous years, we observed an excess of HEV infections between April and September 2013. A total of 202 patients were tested positive of which 79% (160/202) had a cerebrospinal fluid tested positive. Because we performed genotyping using clinical specimens, we obtained representative molecular data related to patients tested positive and found a majority (105/119) of echoviruses 30 (E-30). Phylogenetic analysis revealed that E-30 circulating in Europe since 2000 belong to a unique lineage and showed at the intra-genogroup level the temporal circulation of E-30. Molecular data also indicated that majority of E-30 detected (92%) were almost identical. Compared with data from previous years, this outbreak was finally associated with an excess of patients admitted to an emergency ward for meningitis but also for non-specific viral illness. Our data provide new insights into microevolution of E-30: almost all E-30 emerged from local circulation of one parental virus. Moreover, our findings showed that HEV outbreaks cause an excess of emergency ward consultations but probably also an excess of consultations to general practitioners who receive majority of the non-specific viral illness. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Relationships between hormones and aggressive behavior in green anole lizards: an analysis using structural equation modeling.

    PubMed

    Yang, Eun-Jin; Wilczynski, Walter

    2002-09-01

    We investigated the relationship between aggressive behavior and circulating androgens in the context of agonistic social interaction and examined the effect of this interaction on the androgen-aggression relationship in response to a subsequent social challenge in male Anolis carolinensis lizards. Individuals comprising an aggressive encounter group were exposed to an aggressive conspecific male for 10 min per day during a 5-day encounter period, while controls were exposed to a neutral stimulus for the same period. On the sixth day, their responses to an intruder test were observed. At intervals, individuals were sacrificed to monitor plasma androgen levels. Structural equation modeling (SEM) was used to test three a priori interaction models of the relationship between social stimulus, aggressive behavior, and androgen. Model 1 posits that exposure to a social stimulus influences androgen and aggressive behavior independently. In Model 2, a social stimulus triggers aggressive behavior, which in turn increases circulating levels of androgen. In Model 3, exposure to a social stimulus influences circulating androgen levels, which in turn triggers aggressive behavior. During the 5 days of the encounter period, circulating testosterone (T) levels of the aggressive encounter group followed the same pattern as their aggressive behavioral responses, while the control group did not show significant changes in their aggressive behavior or T level. Our SEM results supported Model 2. A means analysis showed that during the intruder test, animals with 5 days of aggressive encounters showed more aggressive responses than did control animals, while their circulating androgen levels did not differ. This further supports Model 2, suggesting that an animal's own aggressive behavior may trigger increases in levels of plasma androgen. Copyright 2002 Elsevier Science (USA)

  9. Heat exchanger-ingot casting/slicing process, phase 1: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

    NASA Technical Reports Server (NTRS)

    Schmid, F.; Khattak, C. P.

    1977-01-01

    A controlled growth, heat-flow and cool-down process is described that yielded silicon with a high degree of single crystallinity. Even when the seed melted out, very large grains formed. Solar cell samples made from cast material yielded conversion efficiency of over 9%. Representative characterizations of grown silicon demonstrated a dislocation density of less than 100/sq cm and a minority carrier diffusion length of 31 micron. The source of silicon carbide in silicon ingots was identified to be from graphite retainers in contact with silica crucibles. Higher growth rates were achieved with the use of a graphite plug at the bottom of the silica crucible.

  10. System of cryogenic security of the superconducting accelerator of relativistic nuclei-nuclotron

    NASA Astrophysics Data System (ADS)

    Agapov, N. N.; Lipchenko, V. I.; Mazarskij, V. L.; Makarov, L. G.; Sukhanova, A. K.

    The system of cryogenic security of the Nuclotron (superconducting accelerator of relativistic nuclei) is described. The system consists of three helium liquefiers KGU-16004/5. Refrigeration in each liquefier is performed by three preliminary cool-down turboexpanders and a vapor-liquid turboexpander. In this case the refrigeration of the KGU-1600/4.5 liquefiers reaches 1700 W. The system of gas preparation is composed of driers operating at the surrounding temperature. Purification from the admixtures of oxygen, nitrogen, neon, hydrogen and other gases is carried out in low-temperature blocks built in the helium liquefiers KGU-1600/4.5. To store the helium, there are ten 20 cu m receivers under a pressure of 3MPA.

  11. Donation after brain circulation determination of death.

    PubMed

    Dalle Ave, Anne L; Bernat, James L

    2017-02-23

    The fundamental determinant of death in donation after circulatory determination of death is the cessation of brain circulation and function. We therefore propose the term donation after brain circulation determination of death [DBCDD]. In DBCDD, death is determined when the cessation of circulatory function is permanent but before it is irreversible, consistent with medical standards of death determination outside the context of organ donation. Safeguards to prevent error include that: 1] the possibility of auto-resuscitation has elapsed; 2] no brain circulation may resume after the determination of death; 3] complete circulatory cessation is verified; and 4] the cessation of brain function is permanent and complete. Death should be determined by the confirmation of the cessation of systemic circulation; the use of brain death tests is invalid and unnecessary. Because this concept differs from current standards, consensus should be sought among stakeholders. The patient or surrogate should provide informed consent for organ donation by understanding the basis of the declaration of death. In cases of circulatory cessation, such as occurs in DBCDD, death can be defined as the permanent cessation of brain functions, determined by the permanent cessation of brain circulation.

  12. Influence of voluntary control of masticatory side and rhythm on cerebral hemodynamics.

    PubMed

    Hasegawa, Yoko; Ono, Takahiro; Sakagami, Joe; Hori, Kazuhiro; Maeda, Yoshinobu; Hamasaki, Toshimitsu; Nokubi, Takashi

    2011-02-01

    The aim of this study was to investigate the influence on cerebral hemodynamics of voluntary control of masticatory side and rhythm during gum chewing. Blood flow velocity in the middle cerebral artery was measured using transcranial Doppler ultrasonography to evaluate cerebral circulation in healthy volunteers. Heart rate and masseter muscle activity were recorded simultaneously. Volunteers performed three tasks: (1) free gum chewing, (2) gum chewing in which mastication was limited to the right side, and (3) gum chewing in which mastication was limited to the right side and rhythm was set at 1.0 Hz. Changes in cerebral circulation during pre-task, on-task, and post-task periods were analyzed using random effects model, and differences in cerebral circulation and muscle activity between tasks were analyzed using the Friedman test. In all tasks, on-task cerebral circulation was greater than pre-task. Muscle activity and masticatory rhythm varied between tasks, whereas the rate of increase in cerebral circulation did not differ significantly among tasks. These results suggest that cerebral circulation is activated during gum chewing, irrespective of voluntary control of masticatory side and rhythm.

  13. People at High Risk of Developing Flu-Related Complications

    MedlinePlus

    ... UPDATE: Parotitis and Influenza FAQ Parotitis and Influenza Algorithm: Interpreting Influenza Testing Results When Influenza is Circulating Algorithm: Interpreting Influenza Testing Results When Influenza is NOT ...

  14. Serologic and Molecular Evidence of Vaccinia Virus Circulation among Small Mammals from Different Biomes, Brazil

    PubMed Central

    Miranda, Júlia B.; Borges, Iara A.; Campos, Samantha P.S.; Vieira, Flávia N.; de Ázara, Tatiana M.F.; Marques, Fernanda A.; Costa, Galileu B.; Luis, Ana Paula M.F.; de Oliveira, Jaqueline S.; Ferreira, Paulo César P.; Bonjardim, Cláudio Antônio; da Silva, Silvio L.M.; Eiras, Álvaro E.; Abrahão, Jônatas S.; Kroon, Erna G.; Drumond, Betânia P.; Paglia, Adriano P.

    2017-01-01

    Vaccinia virus (VACV) is a zoonotic agent that causes a disease called bovine vaccinia, which is detected mainly in milking cattle and humans in close contact with these animals. Even though many aspects of VACV infection have been described, much is still unknown about its circulation in the environment and its natural hosts/reservoirs. To investigate the presence of Orthopoxvirus antibodies or VACV DNA, we captured small rodents and marsupials in 3 areas of Minas Gerais state, Brazil, and tested their samples in a laboratory. A total of 336 animals were tested; positivity ranged from 18.1% to 25.5% in the 3 studied regions located in different biomes, including the Atlantic Forest and the Cerrado. Analysis of nucleotide sequences indicated co-circulation of VACV groups I and II. Our findings reinforce the possible role played by rodents and marsupials in VACV maintenance and its transmission chain. PMID:28518030

  15. Modeling of circulating fluised beds for post-combustion carbon capture

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, A.; Shadle, L.; Miller, D.

    2011-01-01

    A compartment based model for a circulating fluidized bed reactor has been developed based on experimental observations of riser hydrodynamics. The model uses a cluster based approach to describe the two-phase behavior of circulating fluidized beds. Fundamental mass balance equations have been derived to describe the movement of both gas and solids though the system. Additional work is being performed to develop the correlations required to describe the hydrodynamics of the system. Initial testing of the model with experimental data shows promising results and highlights the importance of including end effects within the model.

  16. Circulation Control Model Experimental Database for CFD Validation

    NASA Technical Reports Server (NTRS)

    Paschal, Keith B.; Neuhart, Danny H.; Beeler, George B.; Allan, Brian G.

    2012-01-01

    A 2D circulation control wing was tested in the Basic Aerodynamic Research Tunnel at the NASA Langley Research Center. A traditional circulation control wing employs tangential blowing along the span over a trailing-edge Coanda surface for the purpose of lift augmentation. This model has been tested extensively at the Georgia Tech Research Institute for the purpose of performance documentation at various blowing rates. The current study seeks to expand on the previous work by documenting additional flow-field data needed for validation of computational fluid dynamics. Two jet momentum coefficients were tested during this entry: 0.047 and 0.114. Boundary-layer transition was investigated and turbulent boundary layers were established on both the upper and lower surfaces of the model. Chordwise and spanwise pressure measurements were made, and tunnel sidewall pressure footprints were documented. Laser Doppler Velocimetry measurements were made on both the upper and lower surface of the model at two chordwise locations (x/c = 0.8 and 0.9) to document the state of the boundary layers near the spanwise blowing slot.

  17. Dynamic leaching and fractionation of trace elements from environmental solids exploiting a novel circulating-flow platform.

    PubMed

    Mori, Masanobu; Nakano, Koji; Sasaki, Masaya; Shinozaki, Haruka; Suzuki, Shiho; Okawara, Chitose; Miró, Manuel; Itabashi, Hideyuki

    2016-02-01

    A dynamic flow-through microcolumn extraction system based on extractant re-circulation is herein proposed as a novel analytical approach for simplification of bioaccessibility tests of trace elements in sediments. On-line metal leaching is undertaken in the format of all injection (AI) analysis, which is a sequel of flow injection analysis, but involving extraction under steady-state conditions. The minimum circulation times and flow rates required to determine the maximum bioaccessible pools of target metals (viz., Cu, Zn, Cd, and Pb) from lake and river sediment samples were estimated using Tessier's sequential extraction scheme and an acid single extraction test. The on-line AIA method was successfully validated by mass balance studies of CRM and real sediment samples. Tessier's test in on-line AI format demonstrated to be carried out by one third of extraction time (6h against more than 17 h by the conventional method), with better analytical precision (<9.2% against >15% by the conventional method) and significant decrease in blank readouts as compared with the manual batch counterpart. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Preventing the Flu: Good Health Habits Can Help Stop Germs

    MedlinePlus

    ... UPDATE: Parotitis and Influenza FAQ Parotitis and Influenza Algorithm: Interpreting Influenza Testing Results When Influenza is Circulating Algorithm: Interpreting Influenza Testing Results When Influenza is NOT ...

  19. [Hot topics of circulating tumor DNA testing in breast cancer].

    PubMed

    Liu, Y H; Zhou, B; Xu, L; Xin, L

    2017-02-01

    The progress of gene detection technologies represented by next generation sequencing (NGS) and digital PCR laid a foundation for studies of circulating tumor DNA (ctDNA) in breast cancer. In 2014, the NGS workgroup organized by the College of American Pathologists (CAP) published the College of American Pathologists ' Laboratory Standards for Next - Generation Sequencing Clinical Tests, which provides a blueprint for the standardization of gene testing. In 2015, the Guidelines for Diagnostic Next - generation Sequencing published by the European Society of Human Genetics claimed that NGS is unacceptable in clinical practice before studies guided by guidelines are approved. Although existing studies show the benefits of ctDNA testing in disease monitoring and prognosis analyzing, we have a ways to go to normalize the procedure and build strict detection criteria.

  20. [Research on the feasibility of a magnetic-coupling-driven axial flow blood pump].

    PubMed

    Yu, Xiaoqing; Ding, Wenxiang; Wang, Wei; Chen, En; Jiang, Zuming; Zou, Wenyan

    2004-02-01

    A new-designed axial flow blood pump, dived by magnetic coupling and using internal hollow brushless DC motor and inlet and outlet in line with impeller, was tested in mimic circuit. The results showed good performance of the new pump and indicated that its hydrodynamic characteristic can meet the demands of clinical extracorporeal circulation and auxiliary circulation.

  1. The utilization of circulating cell-free fetal DNA testing and decrease in invasive diagnostic procedures: an institutional experience.

    PubMed

    Pettit, K E; Hull, A D; Korty, L; Jones, M C; Pretorius, D H

    2014-10-01

    To characterize the patient population utilizing circulating cell-free fetal DNA (ccffDNA) testing at a large academic center and evaluate trends in the performance of invasive diagnostic procedures. A retrospective cohort study of all patients who underwent cell-free DNA testing from May to December 2012 was performed. During the study period, 206 patients had cell-free DNA testing. Of those, 75% (155/206) were of ages ⩾ 35 years. Of those undergoing ccffDNA testing, 41% had positive aneuploidy screening and 38% had abnormal ultrasound findings. Only 7% of the patients with negative ccffDNA testing opted for an invasive diagnostic procedure compared with 60% with positive testing (P<0.01). The rate of invasive procedures decreased from 5.9% of all visits to the center during a similar 8-month period in 2010 to 4.1% of all visits during the study period (P<0.01). Our data suggest that ccffDNA testing leads to reduced uptake of invasive procedures.

  2. High Levels of Peripheral Blood Circulating Plasma Cells as a Specific Risk Factor for Progression of Smoldering Multiple Myeloma

    PubMed Central

    Bianchi, Giada; Kyle, Robert A.; Larson, Dirk R.; Witzig, Thomas E.; Kumar, Shaji; Dispenzieri, Angela; Morice, William G.; Rajkumar, S. Vincent

    2012-01-01

    Smoldering multiple myeloma (SMM) carries a 50% risk of progression to multiple myeloma (MM) or related malignancy within the first 5 years following diagnosis. The goal of this study was to determine if high levels of circulating plasma cells (PCs) are predictive of SMM transformation within the first 2–3 years from diagnosis. Ninety-one patients diagnosed with SMM at Mayo Clinic from January 1994 through January 2007 who had testing for circulating PCs using an immunofluorescent assay and adequate follow up to ascertain disease progression, were studied. High level of circulating PCs was defined as absolute peripheral blood PCs >5000 ×106/L and/or > 5% cytoplasmic immunoglobulin (Ig) positive PCs per 100 peripheral blood mononuclear cells. Patients with high circulating PCs (14 of 91 patients, 15%) were significantly more likely to progress to active disease within 2 years compared with patients without high circulating PCs, 71% versus 25%, respectively, P=0.001. Corresponding rates for progression within 3 years were 86% versus 35%, respectively, P<0.001. Overall survival (OS) after both SMM diagnosis and MM diagnosis was also significantly different. High levels of circulating PCs identify SMM patients with an elevated risk of progression within the first 2 to 3 years following diagnosis. PMID:22902364

  3. Do Circulating Tumor Cells, Exosomes, and Circulating Tumor Nucleic Acids Have Clinical Utility?

    PubMed Central

    Gold, Bert; Cankovic, Milena; Furtado, Larissa V.; Meier, Frederick; Gocke, Christopher D.

    2016-01-01

    Diagnosing and screening for tumors through noninvasive means represent an important paradigm shift in precision medicine. In contrast to tissue biopsy, detection of circulating tumor cells (CTCs) and circulating tumor nucleic acids provides a minimally invasive method for predictive and prognostic marker detection. This allows early and serial assessment of metastatic disease, including follow-up during remission, characterization of treatment effects, and clonal evolution. Isolation and characterization of CTCs and circulating tumor DNA (ctDNA) are likely to improve cancer diagnosis, treatment, and minimal residual disease monitoring. However, more trials are required to validate the clinical utility of precise molecular markers for a variety of tumor types. This review focuses on the clinical utility of CTCs and ctDNA testing in patients with solid tumors, including somatic and epigenetic alterations that can be detected. A comparison of methods used to isolate and detect CTCs and some of the intricacies of the characterization of the ctDNA are also provided. PMID:25908243

  4. Mendelian Randomization Studies Do Not Support a Role for Raised Circulating Triglyceride Levels Influencing Type 2 Diabetes, Glucose Levels, or Insulin Resistance

    PubMed Central

    De Silva, N. Maneka G.; Freathy, Rachel M.; Palmer, Tom M.; Donnelly, Louise A.; Luan, Jian'an; Gaunt, Tom; Langenberg, Claudia; Weedon, Michael N.; Shields, Beverley; Knight, Beatrice A.; Ward, Kirsten J.; Sandhu, Manjinder S.; Harbord, Roger M.; McCarthy, Mark I.; Smith, George Davey; Ebrahim, Shah; Hattersley, Andrew T.; Wareham, Nicholas; Lawlor, Debbie A.; Morris, Andrew D.; Palmer, Colin N.A.; Frayling, Timothy M.

    2011-01-01

    OBJECTIVE The causal nature of associations between circulating triglycerides, insulin resistance, and type 2 diabetes is unclear. We aimed to use Mendelian randomization to test the hypothesis that raised circulating triglyceride levels causally influence the risk of type 2 diabetes and raise normal fasting glucose levels and hepatic insulin resistance. RESEARCH DESIGN AND METHODS We tested 10 common genetic variants robustly associated with circulating triglyceride levels against the type 2 diabetes status in 5,637 case and 6,860 control subjects and four continuous outcomes (reflecting glycemia and hepatic insulin resistance) in 8,271 nondiabetic individuals from four studies. RESULTS Individuals carrying greater numbers of triglyceride-raising alleles had increased circulating triglyceride levels (SD 0.59 [95% CI 0.52–0.65] difference between the 20% of individuals with the most alleles and the 20% with the fewest alleles). There was no evidence that the carriers of greater numbers of triglyceride-raising alleles were at increased risk of type 2 diabetes (per weighted allele odds ratio [OR] 0.99 [95% CI 0.97–1.01]; P = 0.26). In nondiabetic individuals, there was no evidence that carriers of greater numbers of triglyceride-raising alleles had increased fasting insulin levels (SD 0.00 per weighted allele [95% CI −0.01 to 0.02]; P = 0.72) or increased fasting glucose levels (0.00 [−0.01 to 0.01]; P = 0.88). Instrumental variable analyses confirmed that genetically raised circulating triglyceride levels were not associated with increased diabetes risk, fasting glucose, or fasting insulin and, for diabetes, showed a trend toward a protective association (OR per 1-SD increase in log10 triglycerides: 0.61 [95% CI 0.45–0.83]; P = 0.002). CONCLUSIONS Genetically raised circulating triglyceride levels do not increase the risk of type 2 diabetes or raise fasting glucose or fasting insulin levels in nondiabetic individuals. One explanation for our results is that raised circulating triglycerides are predominantly secondary to the diabetes disease process rather than causal. PMID:21282362

  5. Mendelian randomization studies do not support a role for raised circulating triglyceride levels influencing type 2 diabetes, glucose levels, or insulin resistance.

    PubMed

    De Silva, N Maneka G; Freathy, Rachel M; Palmer, Tom M; Donnelly, Louise A; Luan, Jian'an; Gaunt, Tom; Langenberg, Claudia; Weedon, Michael N; Shields, Beverley; Knight, Beatrice A; Ward, Kirsten J; Sandhu, Manjinder S; Harbord, Roger M; McCarthy, Mark I; Smith, George Davey; Ebrahim, Shah; Hattersley, Andrew T; Wareham, Nicholas; Lawlor, Debbie A; Morris, Andrew D; Palmer, Colin N A; Frayling, Timothy M

    2011-03-01

    The causal nature of associations between circulating triglycerides, insulin resistance, and type 2 diabetes is unclear. We aimed to use Mendelian randomization to test the hypothesis that raised circulating triglyceride levels causally influence the risk of type 2 diabetes and raise normal fasting glucose levels and hepatic insulin resistance. We tested 10 common genetic variants robustly associated with circulating triglyceride levels against the type 2 diabetes status in 5,637 case and 6,860 control subjects and four continuous outcomes (reflecting glycemia and hepatic insulin resistance) in 8,271 nondiabetic individuals from four studies. Individuals carrying greater numbers of triglyceride-raising alleles had increased circulating triglyceride levels (SD 0.59 [95% CI 0.52-0.65] difference between the 20% of individuals with the most alleles and the 20% with the fewest alleles). There was no evidence that the carriers of greater numbers of triglyceride-raising alleles were at increased risk of type 2 diabetes (per weighted allele odds ratio [OR] 0.99 [95% CI 0.97-1.01]; P = 0.26). In nondiabetic individuals, there was no evidence that carriers of greater numbers of triglyceride-raising alleles had increased fasting insulin levels (SD 0.00 per weighted allele [95% CI -0.01 to 0.02]; P = 0.72) or increased fasting glucose levels (0.00 [-0.01 to 0.01]; P = 0.88). Instrumental variable analyses confirmed that genetically raised circulating triglyceride levels were not associated with increased diabetes risk, fasting glucose, or fasting insulin and, for diabetes, showed a trend toward a protective association (OR per 1-SD increase in log(10) triglycerides: 0.61 [95% CI 0.45-0.83]; P = 0.002). Genetically raised circulating triglyceride levels do not increase the risk of type 2 diabetes or raise fasting glucose or fasting insulin levels in nondiabetic individuals. One explanation for our results is that raised circulating triglycerides are predominantly secondary to the diabetes disease process rather than causal.

  6. Circulating Mesenchymal Stem Cells Microparticles in Patients with Cerebrovascular Disease

    PubMed Central

    Cho, Yeon Hee; Kang, Ho Young; Hyung, Na Kyum; Kim, Donghee; Lee, Ji Hyun; Nam, Ji Yoon; Bang, Oh Young

    2012-01-01

    Preclinical and clinical studies have shown that the application of CD105+ mesenchymal stem cells (MSCs) is feasible and may lead to recovery after stroke. In addition, circulating microparticles are reportedly functional in various disease conditions. We tested the levels of circulating CD105+ microparticles in patients with acute ischemic stroke. The expression of CD105 (a surface marker of MSCs) and CXCR4 (a CXC chemokine receptor for MSC homing) on circulating microparticles was evaluated by flow cytometry of samples from 111 patients and 50 healthy subjects. The percentage of apoptotic CD105 microparticles was determined based on annexin V (AV) expression. The relationship between serum levels of CD105+/AV− microparticles, stromal cells derived factor-1α (SDF-1α), and the extensiveness of cerebral infarcts was also evaluated. CD105+/AV− microparticles were higher in stroke patients than control subjects. Correlation analysis showed that the levels of CD105+/AV− microparticles increased as the baseline stroke severity increased. Multivariate testing showed that the initial severity of stroke was independently associated with circulating CD105+/AV− microparticles (OR, 1.103 for 1 point increase in the NIHSS score on admission; 95% CI, 1.032–1.178) after adjusting for other variables. The levels of CD105+/CXCR4+/AV− microparticles were also increased in patients with severe disability (r = 0.192, p = 0.046 for NIHSS score on admission), but were decreased with time after stroke onset (r = −0.204, p = 0.036). Risk factor profiles were not associated with the levels of circulating microparticles or SDF-1α. In conclusion, our data showed that stroke triggers the mobilization of MSC-derived microparticles, especially in patients with extensive ischemic stroke. PMID:22615882

  7. Cross-reactions of sera from dogs infected with Angiostrongylus vasorum in commercially available Dirofilaria immitis test kits

    PubMed Central

    2012-01-01

    Background Dirofilaria immitis and Angiostrongylus vasorum are both important potentially fatal canine nematodes with overlapping endemic areas, especially in Europe. The preadult and adult stages of both species are living in the Arteria pulmonalis and the right heart, and diagnostically detectable circulating parasite antigens have been demonstrated for both species. For the detection of D. immitis infections, a variety of commercial tests have been developed, however, they have not been evaluated for cross-reactions against circulating antigens of A. vasorum. Methods In this study, potential cross-reactions of sera from 16 dogs, which were experimentally infected with A. vasorum and which had circulating antigens as confirmed by a species-specific ELISA, were evaluated for the detection of A. vasorum antigen in six commercially available D. immitis test kits. Results In three fast tests (Witness® Dirofilaria, SensPERT® Canine Heartworm, SNAP® 4Dx® Plus), all sera were negative. One fast membrane ELISA (SNAP® HTWM RT Test) was positive with four sera (25%), and one serum delivered a non-valid result twice. In the PetChek® HTWM PF Test, depending on the interpretation protocol, 5 or 8 dogs (31.2 – 50%) were positive. With the DiroCHEK®-ELISA, a single A. vasorum-infected dog (6.2%) tested positive. Conclusions Due to potential cross-reactions with A. vasorum in commercially available test kits for the detection of D. immitis antigen, the simultaneous use of highly specific diagnostic methods for the differentiation of these two canine heart worms is recommended. PMID:23148786

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoder Jr, Graydon L; Heatherly, Dennis Wayne; Williams, David F

    A small molten fluoride salt experiment has been constructed and tested to develop experimental techniques for application in liquid fluoride salt systems. There were five major objectives in developing this test apparatus: Allow visual observation of the salt during testing (how can lighting be introduced, how can pictures be taken, what can be seen) Determine if IR photography can be used to examine components submerged in the salt Determine if the experimental configuration provides salt velocity sufficient for collection of corrosion data for future experimentation Determine if a laser Doppler velocimeter can be used to quantify salt velocities. Acquire naturalmore » circulation heat transfer data in fluoride salt at temperatures up to 700oC All of these objectives were successfully achieved during testing with the exception of the fourth: acquiring velocity data using the laser Doppler velocimeter. This paper describes the experiment and experimental techniques used, and presents data taken during natural circulation testing.« less

  9. Vaccination: Who Should Do It, Who Should Not and Who Should Take Precautions

    MedlinePlus

    ... UPDATE: Parotitis and Influenza FAQ Parotitis and Influenza Algorithm: Interpreting Influenza Testing Results When Influenza is Circulating Algorithm: Interpreting Influenza Testing Results When Influenza is NOT ...

  10. The Effects of Pressure on Gases in Solution: Possible Insights to Improve Microbubble Filtration for Extracorporeal Circulation

    PubMed Central

    Herbst, Daniel P.

    2013-01-01

    Abstract: Improvements in micropore arterial line filter designs used for extracorporeal circulation are still needed because microbubbles larger than the rated pore sizes are being detected beyond the filter outlet. Linked to principles governing the function of micropore filters, fluid pressures contained in extracorporeal circuits also influence the behavior of gas bubbles and the extent to which they are carried in a fluid flow. To better understand the relationship between pressure and microbubble behavior, two ex vivo test circuits with and without inline resistance were designed to assess changes in microbubble load with changes in pressure. Ultrasound Doppler probes were used to measure and compare the quality and quantity of microbubbles generated in each test circuit. Analysis of microbubble load was separated into two distinct phases, the time periods during and immediately after bubble generation. Although microbubble number decreased similarly in both test circuits, changes in microbubble volume were significant only in the test circuit with inline resistance. The test circuit with inline resistance also showed a decrease in the rate of volume transferred across each ultrasound Doppler probe and the microbubble number and size range measured in the postbubble generation period. The present research proposes that fluid pressures contained in extracorporeal circuits may be used to affect gases in solution as a possible method to improve microbubble filtration during extracorporeal circulation. PMID:23930378

  11. The effects of pressure on gases in solution: possible insights to improve microbubble filtration for extracorporeal circulation.

    PubMed

    Herbst, Daniel P

    2013-06-01

    Improvements in micropore arterial line filter designs used for extracorporeal circulation are still needed because microbubbles larger than the rated pore sizes are being detected beyond the filter outlet. Linked to principles governing the function of micropore filters, fluid pressures contained in extracorporeal circuits also influence the behavior of gas bubbles and the extent to which they are carried in a fluid flow. To better understand the relationship between pressure and microbubble behavior, two ex vivo test circuits with and without inline resistance were designed to assess changes in microbubble load with changes in pressure. Ultrasound Doppler probes were used to measure and compare the quality and quantity of microbubbles generated in each test circuit. Analysis of microbubble load was separated into two distinct phases, the time periods during and immediately after bubble generation. Although microbubble number decreased similarly in both test circuits, changes in microbubble volume were significant only in the test circuit with inline resistance. The test circuit with inline resistance also showed a decrease in the rate of volume transferred across each ultrasound Doppler probe and the microbubble number and size range measured in the postbubble generation period. The present research proposes that fluid pressures contained in extracorporeal circuits may be used to affect gases in solution as a possible method to improve microbubble filtration during extracorporeal circulation.

  12. Development of circulation control technology for powered-lift STOL aircraft

    NASA Technical Reports Server (NTRS)

    Englar, Robert J.

    1987-01-01

    The flow entraining capabilities of the Circulation Control Wing high lift system were employed to provide an even stronger STOL potential when synergistically combined with upper surface mounted engines. The resulting configurations generate very high supercirculation lift in addition to a vertical component of the pneumatically deflected engine thrust. A series of small scale wind tunnel tests and full scale static thrust deflection tests are discussed which provide a sufficient data base performance. These tests results show thrust deflections of greater than 90 deg produced pneumatically by nonmoving aerodynamic surfaces, and the ability to maintain constant high lift while varying the propulsive force from high thrust recovery required for short takeoff to high drag generation required for short low speed landings.

  13. ISP33 standard problem on the PACTEL facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Purhonen, H.; Kouhia, J.; Kalli, H.

    ISP33 is the first OECD/NEA/CSNI standard problem related to VVER type of pressurized water reactors. The reference reactor of the PACTEL test facility, which was used to carry out the ISP33 experiment, is the VVER-440 reactor, two of which are located near the Finnish city of Loviisa. The objective of the ISP33 test was to study the natural circulation behaviour of VVER-440 reactors at different coolant inventories. Natural circulation was considered as a suitable phenomenon to focus on by the first VVER related ISP due to its importance in most accidents and transients. The behaviour of the natural circulation wasmore » expected to be different compared to Western type of PWRs as a result of the effect of horizontal steam generators and the hot leg loop seals. This ISP was conducted as a blind problem. The experiment was started at full coolant inventory. Single-phase natural circulation transported the energy from the core to the steam generators. The inventory was then reduced stepwise at about 900 s intervals draining 60 kg each time from the bottom of the downcomer. the core power was about 3.7% of the nominal value. The test was terminated after the cladding temperatures began to rise. ATHLET, CATHARE, RELAP5 (MODs 3, 2.5 and 2), RELAP4/MOD6, DINAMIKA and TECH-M4 codes were used in 21 pre- and 20 posttest calculations submitted for the ISP33.« less

  14. Tumor and circulating biomarkers in patients with second-line hepatocellular carcinoma from the randomized phase II study with tivantinib

    PubMed Central

    Rimassa, Lorenza; Abbadessa, Giovanni; Personeni, Nicola; Porta, Camillo; Borbath, Ivan; Daniele, Bruno; Salvagni, Stefania; Van Laethem, Jean-Luc; Van Vlierberghe, Hans; Trojan, Jörg; De Toni, Enrico N.; Weiss, Alan; Miles, Steven; Gasbarrini, Antonio; Lencioni, Monica; Lamar, Maria E.; Wang, Yunxia; Shuster, Dale; Schwartz, Brian E.; Santoro, Armando

    2016-01-01

    ARQ 197-215 was a randomized placebo-controlled phase II study testing the MET inhibitor tivantinib in second-line hepatocellular carcinoma (HCC) patients. It identified tumor MET as a key biomarker in HCC. Aim of this research was to study the prognostic and predictive value of tumor (MET, the receptor tyrosine kinase encoded by the homonymous MNNG-HOS transforming gene) and circulating (MET, hepatocyte growth factor [HGF], alpha-fetoprotein [AFP], vascular endothelial growth factor [VEGF]) biomarkers in second-line HCC. Tumor MET-High status was centrally assessed by immunohistochemistry. Circulating biomarkers were centrally analyzed on serum samples collected at baseline and every 4-8 weeks, using medians as cut-off to determine High/Low status. Tumor MET, tested in 77 patients, was more frequently High after (82%) versus before (40%) sorafenib. A significant interaction (p = 0.04) between tivantinib and baseline tumor MET in terms of survival was observed. Baseline circulating MET and HGF (102 patients) High status correlated with shorter survival (HR 0.61, p = 0.03, and HR 0.60, p = 0.02, respectively), while the association between AFP (104 patients) or VEGF (103 patients) status and survival was non-significant. Conclusions: Tumor MET levels were higher in patients treated with sorafenib. Circulating biomarkers such as MET and HGF may be prognostic in second-line HCC. These results need to be confirmed in larger randomized clinical trials. PMID:27579536

  15. What Influences Public Library Adult Patrons to Choose the Books They Borrow.

    ERIC Educational Resources Information Center

    Goldhor, Herbert

    This study was conducted in l978/79 to test the hypothesis that the circulation of books put in a prominent display location would increase because of the tendency of adults to select books in public libraries by browsing, rather than looking for specific titles. The circulation of all copies of a sample of ll5 titles from the adult individual…

  16. The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery.

    PubMed

    Yuruk, Koray; Bezemer, Rick; Euser, Mariska; Milstein, Dan M J; de Geus, Hilde H R; Scholten, Evert W; de Mol, Bas A J M; Ince, Can

    2012-09-01

    OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n = 10) or a miniaturized extracorporeal circulation system (n = 10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300 ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7 ± 3.3 vs 24.7 ± 2.0%; P = 0.03; and 6.42 ± 0.75 vs 5.41 ± 0.64 mmol/l; P < 0.01). The density of perfused vessels with a diameter <25 µm (i.e. perfused vessel density) decreased slightly in the conventional extracorporeal circulation-treated group from 16.4 ± 3.8 to 12.8 ± 3.3 mm/mm(2) (P < 0.01) and remained stable in the miniaturized extracorporeal circulation-treated group (16.3 ± 2.7 and 15.2 ± 2.9 mm/mm(2) before and during the pump, respectively). Plasma neutrophil gelatinase-associated lipocalin levels were increased following the use of extracorporeal circulation in both groups, and no differences were observed between the groups. Plasma creatinine levels and creatinine clearance were not affected by CABG surgery or CPB. CONCLUSIONS The results from this relatively small study suggest that the use of the miniaturized extracorporeal circulation system is associated with a statistically significant (but clinically insignificant) reduction in haemodilution and microcirculatory hypoperfusion compared with the use of the conventional extracorporeal circulation system.

  17. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

    PubMed Central

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Background: Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives: The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. Materials and Methods: In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. Results: The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Conclusions: Thus, we can conclude that a simulator system using an extracorporeal circulation system can be set to different models of dialyzers, and that the reproduced treatment scenarios can be used for simulation training. PMID:26981503

  18. Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa.

    PubMed

    Bachanek-Bankowska, Katarzyna; Mero, Herieth R; Wadsworth, Jemma; Mioulet, Valerie; Sallu, Raphael; Belsham, Graham J; Kasanga, Christopher J; Knowles, Nick J; King, Donald P

    2016-11-01

    Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce C T values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n=71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Liquid biopsy: a step forward towards precision medicine in urologic malignancies.

    PubMed

    Di Meo, Ashley; Bartlett, Jenni; Cheng, Yufeng; Pasic, Maria D; Yousef, George M

    2017-04-14

    There is a growing trend towards exploring the use of a minimally invasive "liquid biopsy" to identify biomarkers in a number of cancers, including urologic malignancies. Multiple aspects can be assessed in circulating cell-free DNA, including cell-free DNA levels, integrity, methylation and mutations. Other prospective liquid biopsy markers include circulating tumor cells, circulating RNAs (miRNA, lncRNAs and mRNAs), cell-free proteins, peptides and exosomes have also emerged as non-invasive cancer biomarkers. These circulating molecules can be detected in various biological fluids, including blood, urine, saliva and seminal plasma. Liquid biopsies hold great promise for personalized medicine due to their ability to provide multiple non-invasive global snapshots of the primary and metastatic tumors. Molecular profiling of circulating molecules has been a stepping-stone to the successful introduction of several non-invasive multi-marker tests into the clinic. In this review, we provide an overview of the current state of cell-free DNA-based kidney, prostate and bladder cancer biomarker research and discuss the potential utility other circulating molecules. We will also discuss the challenges and limitations facing non-invasive cancer biomarker discovery and the benefits of this growing area of translational research.

  20. An investigation of anticyclonic circulation in the southern Gulf of Riga during the spring period

    NASA Astrophysics Data System (ADS)

    Soosaar, Edith; Maljutenko, Ilja; Raudsepp, Urmas; Elken, Jüri

    2014-04-01

    Previous studies of the gulf-type Region of Freshwater Influence (ROFI) have shown that circulation near the area of freshwater inflow sometimes becomes anticyclonic. Such a circulation is different from basic coastal ocean buoyancy-driven circulation where an anticyclonic bulge develops near the source and a coastal current is established along the right hand coast (in the northern hemisphere), resulting in the general cyclonic circulation. The spring (from March to June) circulation and spreading of river discharge water in the southern Gulf of Riga (GoR) in the Baltic Sea was analyzed based on the results of a 10-year simulation (1997-2006) using the General Estuarine Transport Model (GETM). Monthly mean currents in the upper layer of the GoR revealed a double gyre structure dominated either by an anticyclonic or cyclonic gyre in the near-head southeastern part and corresponding cyclonic/anticyclonic gyre in the near-mouth northwestern part of the gulf. Time series analysis of PCA and vorticity, calculated from velocity data and model sensitivity tests, showed that in spring the anticyclonic circulation in the upper layer of the southern GoR is driven primarily by the estuarine type density field. This anticyclonic circulation is enhanced by easterly winds but blocked or even reversed by westerly winds. The estuarine type density field is maintained by salt flux in the northwestern connection to the Baltic Proper and river discharge in the southern GoR.

  1. An investigation of anticyclonic circulation in the southern Gulf of Riga during the spring period

    NASA Astrophysics Data System (ADS)

    Soosaar, Edith; Maljutenko, Ilja; Raudsepp, Urmas; Elken, Jüri

    2015-04-01

    Previous studies of the gulf-type Region of Freshwater Influence (ROFI) have shown that circulation near the area of freshwater inflow sometimes becomes anticyclonic. Such a circulation is different from basic coastal ocean buoyancy-driven circulation where an anticyclonic bulge develops near the source and a coastal current is established along the right hand coast (in the northern hemisphere), resulting in the general cyclonic circulation. The spring (from March to June) circulation and spreading of river discharge water in the southern Gulf of Riga (GoR) in the Baltic Sea was analyzed based on the results of a 10-year simulation (1997-2006) using the General Estuarine Transport Model (GETM). Monthly mean currents in the upper layer of the GoR revealed a double gyre structure dominated either by an anticyclonic or cyclonic gyre in the near-head southeastern part and corresponding cyclonic/anticyclonic gyre in the near-mouth northwestern part of the gulf. Time series analysis of PCA and vorticity, calculated from velocity data and model sensitivity tests, showed that in spring the anticyclonic circulation in the upper layer of the southern GoR is driven primarily by the estuarine type density field. This anticyclonic circulation is enhanced by easterly winds but blocked or even reversed by westerly winds. The estuarine type density field is maintained by salt flux in the northwestern connection to the Baltic Proper and river discharge in the southern GoR.

  2. Investigation of Natural Circulation Instability and Transients in Passively Safe Small Modular Reactors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ishii, Mamoru

    The NEUP funded project, NEUP-3496, aims to experimentally investigate two-phase natural circulation flow instability that could occur in Small Modular Reactors (SMRs), especially for natural circulation SMRs. The objective has been achieved by systematically performing tests to study the general natural circulation instability characteristics and the natural circulation behavior under start-up or design basis accident conditions. Experimental data sets highlighting the effect of void reactivity feedback as well as the effect of power ramp-up rate and system pressure have been used to develop a comprehensive stability map. The safety analysis code, RELAP5, has been used to evaluate experimental results andmore » models. Improvements to the constitutive relations for flashing have been made in order to develop a reliable analysis tool. This research has been focusing on two generic SMR designs, i.e. a small modular Simplified Boiling Water Reactor (SBWR) like design and a small integral Pressurized Water Reactor (PWR) like design. A BWR-type natural circulation test facility was firstly built based on the three-level scaling analysis of the Purdue Novel Modular Reactor (NMR) with an electric output of 50 MWe, namely NMR-50, which represents a BWR-type SMR with a significantly reduced reactor pressure vessel (RPV) height. The experimental facility was installed with various equipment to measure thermalhydraulic parameters such as pressure, temperature, mass flow rate and void fraction. Characterization tests were performed before the startup transient tests and quasi-steady tests to determine the loop flow resistance. The control system and data acquisition system were programmed with LabVIEW to realize the realtime control and data storage. The thermal-hydraulic and nuclear coupled startup transients were performed to investigate the flow instabilities at low pressure and low power conditions for NMR-50. Two different power ramps were chosen to study the effect of startup power density on the flow instability. The experimental startup transient results showed the existence of three different flow instability mechanisms, i.e., flashing instability, condensation induced flow instability, and density wave oscillations. In addition, the void-reactivity feedback did not have significant effects on the flow instability during the startup transients for NMR-50. ii Several initial startup procedures with different power ramp rates were experimentally investigated to eliminate the flow instabilities observed from the startup transients. Particularly, the very slow startup transient and pressurized startup transient tests were performed and compared. It was found that the very slow startup transients by applying very small power density can eliminate the flashing oscillations in the single-phase natural circulation and stabilize the flow oscillations in the phase of net vapor generation. The initially pressurized startup procedure was tested to eliminate the flashing instability during the startup transients as well. The pressurized startup procedure included the initial pressurization, heat-up, and venting process. The startup transient tests showed that the pressurized startup procedure could eliminate the flow instability during the transition from single-phase flow to two-phase flow at low pressure conditions. The experimental results indicated that both startup procedures were applicable to the initial startup of NMR. However, the pressurized startup procedures might be preferred due to short operating hours required. In order to have a deeper understanding of natural circulation flow instability, the quasi-steady tests were performed using the test facility installed with preheater and subcooler. The effect of system pressure, core inlet subcooling, core power density, inlet flow resistance coefficient, and void reactivity feedback were investigated in the quasi-steady state tests. The experimental stability boundaries were determined between unstable and stable flow conditions in the dimensionless stability plane of inlet subcooling number and Zuber number. To predict the stability boundary theoretically, linear stability analysis in the frequency domain was performed at four sections of the natural circulation test loop. The flashing phenomena in the chimney section was considered as an axially uniform heat source. And the dimensionless characteristic equation of the pressure drop perturbation was obtained by considering the void fraction effect and outlet flow resistance in the core section. The theoretical flashing boundary showed some discrepancies with previous experimental data from the quasi-steady state tests. In the future, thermal non-equilibrium was recommended to improve the accuracy of flashing instability boundary. As another part of the funded research, flow instabilities of a PWR-type SMR under low pressure and low power conditions were investigated experimentally as well. The NuScale reactor design was selected as the prototype for the PWR-type SMR. In order to experimentally study the natural circulation behavior of NuScale iii reactor during accidental scenarios, detailed scaling analyses are necessary to ensure that the scaled phenomena could be obtained in a laboratory test facility. The three-level scaling method is used as well to obtain the scaling ratios derived from various non-dimensional numbers. The design of the ideally scaled facility (ISF) was initially accomplished based on these scaling ratios. Then the engineering scaled facility (ESF) was designed and constructed based on the ISF by considering engineering limitations including laboratory space, pipe size, and pipe connections etc. PWR-type SMR experiments were performed in this well-scaled test facility to investigate the potential thermal hydraulic flow instability during the blowdown events, which might occur during the loss of coolant accident (LOCA) and loss of heat sink accident (LOHS) of the prototype PWR-type SMR. Two kinds of experiments, normal blowdown event and cold blowdown event, were experimentally investigated and compared with code predictions. The normal blowdown event was experimentally simulated since an initial condition where the pressure was lower than the designed pressure of the experiment facility, while the code prediction of blowdown started from the normal operation condition. Important thermal hydraulic parameters including reactor pressure vessel (RPV) pressure, containment pressure, local void fraction and temperature, pressure drop and natural circulation flow rate were measured and analyzed during the blowdown event. The pressure and water level transients are similar to the experimental results published by NuScale [51], which proves the capability of current loop in simulating the thermal hydraulic transient of real PWR-type SMR. During the 20000s blowdown experiment, water level in the core was always above the active fuel assemble during the experiment and proved the safety of natural circulation cooling and water recycling design of PWR-type SMR. Besides, pressure, temperature, and water level transient can be accurately predicted by RELAP5 code. However, the oscillations of natural circulation flow rate, water level and pressure drops were observed during the blowdown transients. This kind of flow oscillations are related to the water level and the location upper plenum, which is a path for coolant flow from chimney to steam generator and down comer. In order to investigate the transients start from the opening of ADS valve in both experimental and numerical way, the cold blow-down experiment is conducted. For the cold blowdown event, different from setting both reactor iv pressure vessel (RPV) and containment at high temperature and pressure, only RPV was heated close to the highest designed pressure and then open the ADS valve, same process was predicted using RELAP5 code. By doing cold blowdown experiment, the entire transients from the opening of ADS can be investigated by code and benchmarked with experimental data. Similar flow instability observed in the cold blowdown experiment. The comparison between code prediction and experiment data showed that the RELAP5 code can successfully predict the pressure void fraction and temperature transient during the cold blowdown event with limited error, but numerical instability exists in predicting natural circulation flow rate. Besides, the code is lack of capability in predicting the water level related flow instability observed in experiments.« less

  3. Disturbances in Pro-Oxidant-Antioxidant Balance after Passive Body Overheating and after Exercise in Elevated Ambient Temperatures in Athletes and Untrained Men

    PubMed Central

    Pilch, Wanda; Szygula, Zbigniew; Tyka, Anna K.; Palka, Tomasz; Tyka, Aleksander; Cison, Tomasz; Pilch, Pawel; Teleglow, Aneta

    2014-01-01

    The aim of the study was to investigate pro-oxidant-antioxidant balance in two series of examinations with two types of stressors (exogenous heat and the combined exogenous and endogenous heat) in trained and untrained men. The exogenous stressor was provided by Finnish sauna session, whereas the combined stressor was represented by the exercise in elevated ambient temperature. The men from the two groups performed the physical exercise on a cycle ergometer with the load of 53±2% maximal oxygen uptake at the temperature of 33±1°C and relative humidity of 70% until their rectal temperature rose by 1.2°C. After a month from completion of the exercise test the subjects participated in a sauna bathing session with the temperature of 96±2°C, and relative humidity of 16±5%. 15-minutes heating and 2-minute cool-down in a shower with the temperature of 20°C was repeated until rectal temperature rose by 1.2°C compared to the initial value. During both series of tests rectal temperature was measured at 5-minute intervals. Before both series of tests and after them body mass was measured and blood samples were taken for biochemical tests. Serum total protein, serum concentration of lipid peroxidation products and serum antioxidants were determined. The athletes were characterized by higher level of antioxidant status and lower concentration of lipid peroxidation products. Physical exercise at elevated ambient temperature caused lower changes in oxidative stress indices compared to sauna bathing. Sauna induced a shift in pro-oxidant-antioxidant balance towards oxidation, which was observed less intensively in the athletes compared to the untrained men. This leads to the conclusion that physical exercise increases tolerance to elevated ambient temperature and oxidative stress. PMID:24465535

  4. PWR-related integral safety experiments in the PKL 111 test facility SBLOCA under beyond-design-basis accident conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Weber, P.; Umminger, K.J.; Schoen, B.

    1995-09-01

    The thermal hydraulic behavior of a PWR during beyond-design-basis accident scenarios is of vital interest for the verification and optimization of accident management procedures. Within the scope of the German reactor safety research program experiments were performed in the volumetrically scaled PKL 111 test facility by Siemens/KWU. This highly instrumented test rig simulates a KWU-design PWR (1300 MWe). In particular, the latest tests performed related to a SBLOCA with additional system failures, e.g. nitrogen entering the primary system. In the case of a SBLOCA, it is the goal of the operator to put the plant in a condition where themore » decay heat can be removed first using the low pressure emergency core cooling system and then the residual heat removal system. The experimental investigation presented assumed the following beyond-design-basis accident conditions: 0.5% break in a cold leg, 2 of 4 steam generators (SGs) isolated on the secondary side (feedwater- and steam line-valves closed), filled with steam on the primary side, cooldown of the primary system using the remaining two steam generators, high pressure injection system only in the two loops with intact steam generators, if possible no operator actions to reach the conditions for residual heat removal system activation. Furthermore, it was postulated that 2 of the 4 hot leg accumulators had a reduced initial water inventory (increased nitrogen inventory), allowing nitrogen to enter the primary system at a pressure of 15 bar and nearly preventing the heat transfer in the SGs ({open_quotes}passivating{close_quotes} U-tubes). Due to this the heat transfer regime in the intact steam generators changed remarkably. The primary system showed self-regulating system effects and heat transfer improved again (reflux-condenser mode in the U-tube inlet region).« less

  5. Comparison between supervised and partly supervised cardiac rehabilitation protocols in hypertensive patients: a randomized controlled trial.

    PubMed

    Parreira, Larissa Barreto; de Oliveira Vitorino, Priscila Valverde; Jardim, Paulo Cesar Brandao Veiga; Sousa, Ana Luiza Lima; Jardim, Thiago Veiga; de Moura Sousa, Watila; Justo, Alberto Fenrando Oliveira; Barroso, Weimar Kunz Sebba

    2018-04-13

    Hypertension (HTN) is the main cause of cardiovascular diseases accounting for one third of global mortality. Physical exercise reduces the incidence and prevalence of HTN and cardiovascular morbidity and mortality. Exercises recommended for hypertensive patients include supervised cardiac rehabilitation, which occurs in rehabilitation centers, and partly supervised rehabilitation, with individual prescription of exercises conducted at patients' residences. Compare clinical and functional parameters of hypertensive patients subjected to two cardiac rehabilitation protocols: supervised and partly supervised. Hypertensive patients stage I or II were randomly divided into group one (G1) (partly supervised cardiac rehabilitation) and group two (G2) (supervised cardiac rehabilitation). All patients performed warm-up, aerobic exercise, strength training and cool-down. Participants' assessments conducted before and after intervention included: physical examination, six-minute walk test, cardiac stress test, metabolic tests, and central and peripheral blood pressure measurements. A total of 61 patients (mean age 60.3±11.3 years , 78.7% women) were randomized (30 in G1 and 31 in G2). At the end of the intervention, G1 increased 30.6 meters (p=0.004) and G2 increased 55.0 meters (p>0.001) the distance covered in the six-minute walk test. G2 showed an increase in the maximum oxygen consumption from 24.7±8.6 mlO2/Kg/min to 28.4±7.5 mlO2/Kg/min (p=0.003). Compliance with the intervention was similar in G1 and G2 (77.5±11% x 82±10%; p=0.654). Participants from both groups improved their physical fitness and showed satisfactory compliance and tolerability to the interventions. Supervised exercise was more effective in improving muscle strength and some physical fitness parameters. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Automatic control of cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Balakrishna, S.

    1989-01-01

    Inadequate Reynolds number similarity in testing of scaled models affects the quality of aerodynamic data from wind tunnels. This is due to scale effects of boundary-layer shock wave interaction which is likely to be severe at transonic speeds. The idea of operation of wind tunnels using test gas cooled to cryogenic temperatures has yielded a quantrum jump in the ability to realize full scale Reynolds number flow similarity in small transonic tunnels. In such tunnels, the basic flow control problem consists of obtaining and maintaining the desired test section flow parameters. Mach number, Reynolds number, and dynamic pressure are the three flow parameters that are usually required to be kept constant during the period of model aerodynamic data acquisition. The series of activity involved in modeling, control law development, mechanization of the control laws on a microcomputer, and the performance of a globally stable automatic control system for the 0.3-m Transonic Cryogenic Tunnel (TCT) are discussed. A lumped multi-variable nonlinear dynamic model of the cryogenic tunnel, generation of a set of linear control laws for small perturbation, and nonlinear control strategy for large set point changes including tunnel trajectory control are described. The details of mechanization of the control laws on a 16 bit microcomputer system, the software features, operator interface, the display and safety are discussed. The controller is shown to provide globally stable and reliable temperature control to + or - 0.2 K, pressure to + or - 0.07 psi and Mach number to + or - 0.002 of the set point value. This performance is obtained both during large set point commands as for a tunnel cooldown, and during aerodynamic data acquisition with intrusive activity like geometrical changes in the test section such as angle of attack changes, drag rake movements, wall adaptation and sidewall boundary-layer removal. Feasibility of the use of an automatic Reynolds number control mode with fixed Mach number control is demonstrated.

  7. The 160 TES bolometer read-out using FDM for SAFARI

    NASA Astrophysics Data System (ADS)

    Hijmering, R. A.; den Hartog, R. H.; van der Linden, A. J.; Ridder, M.; Bruijn, M. P.; van der Kuur, J.; van Leeuwen, B. J.; van Winden, P.; Jackson, B.

    2014-07-01

    For the read out of the Transition Edge Sensors (TES) bolometer arrays of the SAFARI instrument on the Japanese background-limited far-IR SPICA mission SRON is developing a Frequency Domain Multiplexing (FDM) read-out system. The next step after the successful demonstration of the read out of 38 TES bolometers using FDM was to demonstrate the FDM readout of the required 160 TES bolometers. Of the 160 LC filter and TES bolometer chains 151 have been connected and after cooldown 148 of the resonances could be identified. Although initial operation and locking of the pixels went smoothly the experiment revealed several complications. In this paper we describe the 160 pixel FDM set-up, show the results and discuss the issues faced during operation of the 160 pixel FDM experiment.

  8. Thermal–mechanical stress analysis of pressurized water reactor pressure vessel with/without a preexisting crack under grid load following conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohanty, Subhasish; Soppet, William K.; Majumdar, Saurin

    In this paper, we present thermal-mechanical stress analysis of a pressurized water reactor pressure vessel and its hot-leg and cold-leg nozzles. Results are presented from thermal and thermal-mechanical stress analysis under reactor heat-up, cool-down, and grid load-following conditions. Analysis results are given with and without the presence of preexisting crack in the reactor nozzle (axial crack in hot leg nozzle). From the model results it is found that the stress-strain states are significantly higher in case of presence of crack than without crack. In conclusion, the stress-strain state under grid load following condition are more realistic compared to the stress-strainmore » state estimated assuming simplified transients.« less

  9. Chronic Osteomyelitis of the Distal Femur Treated with Resection and Delayed Endoprosthetic Reconstruction: A Report of Three Cases.

    PubMed

    Ryan, Sean; Eward, William; Brigman, Brian; Zura, Robert

    2017-01-01

    Chronic osteomyelitis involving the distal femur often results in amputation or arthrodesis. This article presents three cases of chronic osteomyelitis treated with a staged approach culminating in endoprosthetic reconstruction. Stage one involved resection of infected bone and placement of an intramedullary nail spanning the bony defect between proximal femur and tibia, with antibiotic cement packed around the nail. Patients were then placed on long-term IV +/- oral antibiotics to clear the infection. A "cooldown" period was then used between stages where patients were off antibiotics and inflammatory markers were monitored for signs of remaining infection. Stage two then involved reconstruction of the distal femur and knee with an endoprosthesis. In the appropriate patient, this treatment strategy offers another option in this challenging population.

  10. The Windowless Gaseous Tritium Source (WGTS) of the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Heizmann, Florian; Seitz-Moskaliuk, Hendrik; KATRIN Collaboration

    2017-09-01

    The Karlsruhe Tritium Neutrino Experiment (KATRIN) will perform a direct, kinematics-based measurement of the neutrino mass with a sensitivity of 200 meV (90 % C. L.), which will be reached after 3 years of measurement time. The neutrino mass is obtained by investigating the shape of the energy spectrum of tritium β-decay electrons close to the endpoint at 18.6 keV with a spectrometer of MAC-E filter type. This contribution reviews the current status of the tritium source cryostat and magnet system which is currently in its first cool-down phase. Furthermore, the next steps of the comprehensive pre-tritium measurement programme to characterise the apparatus and investigate important systematics are outlined. This work is supported by BMBF (05A14VK2) and the Helmholtz Association.

  11. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peterson, T. J.; Weisend, II, J. G.

    The TESLA collaboration developed a unique variant of SRF cryomodule designs, the chief feature being use of the large, low pressure helium vapor return pipe as the structural support backbone of the cryomodule. Additional innovative features include all cryogenic piping within the cryomodule (no parallel external cryogenic transfer line), long strings of RF cavities within a single cryomodule, and cryomodules connected in series. Several projects, including FLASH and XFEL at DESY, LCLS-II at SLAC, and the ILC technical design have adopted this general design concept. Advantages include saving space by eliminating the external transfer line, relatively tight packing of RFmore » cavities along the beamline due to fewer warm-cold transitions, and potentially lower costs. However, a primary disadvantage is the relative lack of independence for warm-up, replacement, and cool-down of individual cryomodules.« less

  12. Thermal–mechanical stress analysis of pressurized water reactor pressure vessel with/without a preexisting crack under grid load following conditions

    DOE PAGES

    Mohanty, Subhasish; Soppet, William K.; Majumdar, Saurin; ...

    2016-10-26

    In this paper, we present thermal-mechanical stress analysis of a pressurized water reactor pressure vessel and its hot-leg and cold-leg nozzles. Results are presented from thermal and thermal-mechanical stress analysis under reactor heat-up, cool-down, and grid load-following conditions. Analysis results are given with and without the presence of preexisting crack in the reactor nozzle (axial crack in hot leg nozzle). From the model results it is found that the stress-strain states are significantly higher in case of presence of crack than without crack. In conclusion, the stress-strain state under grid load following condition are more realistic compared to the stress-strainmore » state estimated assuming simplified transients.« less

  13. Exercise following myocardial infarction. Current recommendations.

    PubMed

    Leon, A S

    2000-05-01

    Cardiac rehabilitation services are comprehensive long term programmes designed to limit the physiological and psychological effects of cardiovascular disease (CVD), control cardiac symptoms and reduce the risk of subsequent CVD events by stabilising or partially reversing the underlying atherosclerosis process through risk factor modification. Exercise training is the cornerstone of such programmes. Ideally, exercise conditioning or training for the stable cardiac patient should include a combination of cardiorespiratory endurance (aerobic) training, arm exercises and muscular conditioning resistance (strength) training. Flexibility exercises should also be performed, usually as part of the warm-up and cool-down routines preceding and following endurance and strength training. This review discusses the potential physiological, psychological and health benefits of regular exercise and provides guidelines for exercise training for the rehabilitation of post-myocardial infarction patients following hospitalisation.

  14. Usutu virus persistence and West Nile virus inactivity in the Emilia-Romagna region (Italy) in 2011.

    PubMed

    Calzolari, Mattia; Bonilauri, Paolo; Bellini, Romeo; Albieri, Alessandro; Defilippo, Francesco; Tamba, Marco; Tassinari, Massimo; Gelati, Antonio; Cordioli, Paolo; Angelini, Paola; Dottori, Michele

    2013-01-01

    The circulation of West Nile virus and Usutu virus was detected in the Emilia-Romagna region in 2008 and 2009. To evaluate the extent of circulation of both viruses, environmental surveillance, based on bird and mosquito testing, was conducted in 2008 and gradually improved over the years. In February-March 2009-2011, 5,993 hibernating mosquitoes were manually sampled, out of which 80.1% were Culex pipiens; none tested positive for the viruses. From 2008 to 2011, 946,213 mosquitoes, sampled between May and October, were tested; 86.5% were Cx. pipiens. West Nile virus was detected in 32 Cx. pipiens pools, and Usutu virus was detected in 229 mosquito pools (217 Cx. pipiens, 10 Aedes albopictus, one Anopheles maculipennis s.l., and one Aedes caspius). From 2009 to 2011, of 4,546 birds collected, 42 tested positive for West Nile virus and 48 for Usutu virus. West Nile virus and Usutu virus showed different patterns of activity during the 2008-2011 surveillance period. West Nile virus was detected in 2008, 2009, and 2010, but not in 2011. Usutu virus, however, was continuously active throughout 2009, 2010, and 2011. The data strongly suggest that both viruses overwinter in the surveyed area rather than being continually reintroduced every season. The lack of hibernating mosquitoes testing positive for the viruses and the presence of positive birds sampled early in the season support the hypothesis that the viruses overwinter in birds rather than in mosquitoes. Herd immunity in key bird species could explain the decline of West Nile virus observed in 2011, while the persistence of Usutu virus may be explained by not yet identified reservoirs. Reported results are comparable with a peri-Mediterranean circulation of the West Nile virus lineage 1 related strain, which became undetectable in the environment after two to three years of obvious circulation.

  15. Sub-cooled liquid nitrogen cryogenic system with neon turbo-refrigerator for HTS power equipment

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Hirai, H.; Nara, N.; Ozaki, S.; Hirokawa, M.; Eguchi, T.; Hayashi, H.; Iwakuma, M.; Shiohara, Y.

    2014-01-01

    We developed a prototype sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The system consists of a neon turbo-Brayton refrigerator with a LN sub-cooler and LN circulation pump unit. The neon refrigerator has more than 2 kW cooling power at 65 K. The LN sub-cooler is a plate-fin type heat exchanger and is installed in a refrigerator cold box. In order to carry out the system performance tests, a dummy cryostat having an electric heater was set instead of a HTS power equipment. Sub-cooled LN is delivered into the sub-cooler by the LN circulation pump and cooled within it. After the sub-cooler, sub-cooled LN goes out from the cold box to the dummy cryostat, and comes back to the pump unit. The system can control an outlet sub-cooled LN temperature by adjusting refrigerator cooling power. The refrigerator cooling power is automatically controlled by the turbo-compressor rotational speed. In the performance tests, we increased an electric heater power from 200 W to 1300 W abruptly. We confirmed the temperature fluctuation was about ±1 K. We show the cryogenic system details and performance test results in this paper.

  16. Serologic evidence of exposure to Rift Valley fever virus detected in Tunisia

    PubMed Central

    Bosworth, A.; Ghabbari, T.; Dowall, S.; Varghese, A.; Fares, W.; Hewson, R.; Zhioua, E.; Chakroun, M.; Tiouiri, H.; Ben Jemaa, M.; Znazen, A.; Letaief, A.

    2015-01-01

    Rift Valley fever virus (RVFv) is capable of causing dramatic outbreaks amongst economically important animal species and is capable of causing severe symptoms and mortality in humans. RVFv is known to circulate widely throughout East Africa; serologic evidence of exposure has also been found in some northern African countries, including Mauritania. This study aimed to ascertain whether RVFv is circulating in regions beyond its known geographic range. Samples from febrile patients (n = 181) and nonfebrile healthy agricultural and slaughterhouse workers (n = 38) were collected during the summer of 2014 and surveyed for exposure to RVFv by both serologic tests and PCR. Of the 219 samples tested, 7.8% of nonfebrile participants showed immunoglobulin G reactivity to RVFv nucleoprotein and 8.3% of febrile patients showed immunoglobulin M reactivity, with the latter samples indicating recent exposure to the virus. Our results suggest an active circulation of RVFv and evidence of human exposure in the population of Tunisia. PMID:26740887

  17. USSR Report, Space Biology and Aerospace Medicine, Vol. 18, No. 5, September-October 1984

    DTIC Science & Technology

    1984-11-20

    Exchange and Pulmonary Circulation in Man 34 Regional Circulation During Testing on Isokinetic Dynamometer Following 14-Day Bedrest 39 Primate...Indicator of Animal Adaptation to Altitude Hypoxia . 71 Distinctions of Rat Lymphatic Organ Reactions to Acute Stress Factor During Hypokinesia...14, 40, 51].^ Experimental validation of the energy principle of noise effects made it possible to turn to estimation of its equivalent level. The

  18. Circulating DNA and its methylation level in inflammatory bowel disease and related colon cancer.

    PubMed

    Bai, Xuming; Zhu, Yaqun; Pu, Wangyang; Xiao, Li; Li, Kai; Xing, Chungen; Jin, Yong

    2015-01-01

    Both of chronic inflammation and abnormal immune in inflammatory bowel disease can induce colon cancer. Previous research showed that cell apoptosis and necrosis become the main source of circulating DNA in the peripheral blood during tumorigenesis that reduced along with methylation degree. However, its role in the process of colitis transforming to colon cancer is not clarified. Drinking 3% DSS was used to establish colitis model, while 3% dextran sodium sulfate (DSS) combined with azo oxidation methane (AOM) intraperitoneal injection was applied to establish colitis related colon cancer model. Circulating DNA and its methylation level in peripheral blood were tested. Morphology observation, HE staining, and p53 and β-catenin expression detection confirmed that drinking 3% DSS and 3% DSS combined with AOM intraperitoneal injection can successfully establish colitis and colitis associated colorectal cancer models. Circulating DNA level in colitis and colon cancer mice increased by gradient compared with control, while significant difference was observed between each other. Circulating DNA methylation level decreased obviously in colitis and colon cancer, and significant difference was observed between each other. Abnormal protein expression, circulating DNA and its methylation level in ulcerative colitis associated colorectal tissues change in gradient, suggesting that circulating DNA and its methylation level can be treated as new markers for colitis cancer transformation that has certain significance to explore the mechanism of human ulcerative colitis canceration.

  19. Critical rate of electrolyte circulation for preventing zinc dendrite formation in a zinc-bromine redox flow battery

    NASA Astrophysics Data System (ADS)

    Yang, Hyeon Sun; Park, Jong Ho; Ra, Ho Won; Jin, Chang-Soo; Yang, Jung Hoon

    2016-09-01

    In a zinc-bromine redox flow battery, a nonaqueous and dense polybromide phase formed because of bromide oxidation in the positive electrolyte during charging. This formation led to complicated two-phase flow on the electrode surface. The polybromide and aqueous phases led to different kinetics of the Br/Br- redox reaction; poor mixing of the two phases caused uneven redox kinetics on the electrode surface. As the Br/Br- redox reaction was coupled with the zinc deposition reaction, the uneven redox reaction on the positive electrode was accompanied by nonuniform zinc deposition and zinc dendrite formation, which degraded battery stability. A single-flow cell was operated at varying electrolyte circulation rates and current densities. Zinc dendrite formation was observed after cell disassembly following charge-discharge testing. In addition, the flow behavior in the positive compartment was observed by using a transparent version of the cell. At low rate of electrolyte circulation, the polybromide phase clearly separated from the aqueous phase and accumulated at the bottom of the flow frame. In the corresponding area on the negative electrode, a large amount of zinc dendrites was observed after charge-discharge testing. Therefore, a minimum circulation rate should be considered to avoid poor mixing of the positive electrolyte.

  20. 21 CFR 862.1130 - Blood volume test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blood volume test system. 862.1130 Section 862....1130 Blood volume test system. (a) Identification. A blood volume test system is a device intended to measure the circulating blood volume. Blood volume measurements are used in the diagnosis and treatment of...

  1. In vivo acoustic and photoacoustic focusing of circulating cells

    NASA Astrophysics Data System (ADS)

    Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.

    2016-03-01

    In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models.

  2. In vivo acoustic and photoacoustic focusing of circulating cells

    PubMed Central

    Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.

    2016-01-01

    In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models. PMID:26979811

  3. Circulating tumor cells in clinical research and monitoring patients with colorectal cancer

    PubMed Central

    Burz, Claudia; Pop, Vlad-Vasile; Buiga, Rares; Daniel, Sur; Samasca, Gabriel; Aldea, Cornel; Lupan, Iulia

    2018-01-01

    Colorectal cancer remains a frequent disease to which screening and target therapy exist, but despite this is still marked by a high mortality rate. Even though radical surgery may be performed in many cases, patients relapse with metastatic disease. Circulating tumor cells were incriminated for tumor recurrence, that's why vigorous research started on their field. Owning prognostic and predictive value, it was revealed their usefulness in disease monitoring. Moreover, they may serve as liquid biopsies for genetic tests in cases where tissue biopsy is contraindicated or cannot be performed. In spite of these advantages, they were not included in clinical guidelines, despite CellSearch and many other detection methods were developed to ease the identification of circulating tumor cells. This review highlights the implication of circulating tumor cells in metastasis cascade, intrinsic tumor cells mechanisms and correlations with clinical parameters along with their utility for medical practice and detection techniques. PMID:29849961

  4. Circulating Tumor Cells Versus Circulating Tumor DNA in Colorectal Cancer: Pros and Cons

    PubMed Central

    Tan, Carlyn Rose C.; Zhou, Lanlan

    2016-01-01

    Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) are emerging noninvasive multifunctional biomarkers in liquid biopsy allowing for early diagnosis, accurate prognosis, therapeutic target selection, spatiotemporal monitoring of metastasis, as well as monitoring response and resistance to treatment. CTCs and ctDNA are released from different tumor types at different stages and contribute complementary information for clinical decision. Although big strides have been taken in technology development for detection, isolation and characterization of CTCs and sensitive and specific detection of ctDNA, CTC-, and ctDNA-based liquid biopsies may not be widely adopted for routine cancer patient care until the suitability, accuracy, and reliability of these tests are validated and more standardized protocols are corroborated in large, independent, prospectively designed trials. This review covers CTC- and ctDNA-related technologies and their application in colorectal cancer. The promise of CTC-and ctDNA-based liquid biopsies is envisioned. PMID:27516729

  5. Circulating Tumor Cells Versus Circulating Tumor DNA in Colorectal Cancer: Pros and Cons.

    PubMed

    Tan, Carlyn Rose C; Zhou, Lanlan; El-Deiry, Wafik S

    2016-06-01

    Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) are emerging noninvasive multifunctional biomarkers in liquid biopsy allowing for early diagnosis, accurate prognosis, therapeutic target selection, spatiotemporal monitoring of metastasis, as well as monitoring response and resistance to treatment. CTCs and ctDNA are released from different tumor types at different stages and contribute complementary information for clinical decision. Although big strides have been taken in technology development for detection, isolation and characterization of CTCs and sensitive and specific detection of ctDNA, CTC-, and ctDNA-based liquid biopsies may not be widely adopted for routine cancer patient care until the suitability, accuracy, and reliability of these tests are validated and more standardized protocols are corroborated in large, independent, prospectively designed trials. This review covers CTC- and ctDNA-related technologies and their application in colorectal cancer. The promise of CTC-and ctDNA-based liquid biopsies is envisioned.

  6. Evaluation of Two Commercial Enzyme-Linked Immunosorbent Assay Kits for the Detection of Human Circulating Metrnl.

    PubMed

    Zheng, Si-Li; Li, Zhi-Yong; Zhang, Zheng; Wang, Dong-Sheng; Xu, Jian; Miao, Chao-Yu

    2018-04-01

    Metrnl is a newly discovered secreted protein with neurotrophic activity and metabolic effect, while in earlier studies its circulating level in human was not explored. We evaluated two commercial enzyme-linked immunosorbent assay kits (DY7867-05, R&D Systems and SK00478-02, Aviscera Bioscience) for the detection of human circulating Metrnl. The DY7867-05 kit showed superiority over the SK00478-02 kit since it generated better curve fitting degree, smaller variation among tests, higher inter-assay reproducibility and better specificity, and could effectively detect human Metrnl in six types of blood samples. Subsequent analysis was performed using the DY7867-05 kit. Sample storage conditions were investigated. No gender difference in circulating Metrnl levels was found, while people with newly diagnosed type 2 diabetes mellitus (T2DM) had significantly lower Metrnl levels compared to the healthy controls.

  7. The dynamics of the Snowball Earth Hadley circulation for off-equatorial and seasonally varying insolation

    NASA Astrophysics Data System (ADS)

    Voigt, A.

    2013-11-01

    I study the Hadley circulation of a completely ice-covered Snowball Earth through simulations with a comprehensive atmosphere general circulation model. Because the Snowball Earth atmosphere is an example of a dry atmosphere, these simulations allow me to test to what extent dry theories and idealized models capture the dynamics of realistic dry Hadley circulations. Perpetual off-equatorial as well as seasonally varying insolation is used, extending a previous study for perpetual on-equatorial (equinox) insolation. Vertical diffusion of momentum, representing the momentum transport of dry convection, is fundamental to the momentum budgets of both the winter and summer cells. In the zonal budget, it is the primary process balancing the Coriolis force. In the meridional budget, it mixes meridional momentum between the upper and the lower branch and thereby decelerates the circulation. Because of the latter, the circulation intensifies by a factor of three when vertical diffusion of momentum is suppressed. For seasonally varying insolation, the circulation undergoes rapid transitions from the weak summer into the strong winter regime. Consistent with previous studies in idealized models, these transitions result from a mean-flow feedback, because of which they are insensitive to the treatment of vertical diffusion of momentum. Overall, the results corroborate previous findings for perpetual on-equatorial insolation. They demonstrate that descriptions of realistic dry Hadley circulations, in particular their strength, need to incorporate the vertical momentum transport by dry convection, a process that is neglected in most dry theories and idealized models. An improved estimate of the strength of the Snowball Earth Hadley circulation will also help to better constrain the climate of a possible Neoproterozoic Snowball Earth and its deglaciation threshold.

  8. The dynamics of the Snowball Earth Hadley circulation for off-equatorial and seasonally-varying insolation

    NASA Astrophysics Data System (ADS)

    Voigt, A.

    2013-08-01

    I study the Hadley circulation of a completely ice-covered Snowball Earth through simulations with a comprehensive atmosphere general circulation model. Because the Snowball Earth atmosphere is an example of a dry atmosphere, these simulations allow me to test to what extent dry theories and idealized models capture the dynamics of dry Hadley circulations. Perpetual off-equatorial as well as seasonally-varying insolation is used, extending a previous study for perpetual on-equatorial (equinox) insolation. Vertical diffusion of momentum, representing the momentum transport of dry convection, is fundamental to the momentum budgets of both the winter and summer cells. In the zonal budget, it is the primary process balancing the Coriolis force. In the meridional budget, it mixes meridional momentum between the upper and the lower branch and thereby decelerates the circulation. Because of the latter, the circulation intensifies by a factor of three when vertical diffusion of momentum is suppressed. For seasonally-varying insolation, the circulation undergoes rapid transitions from the weak summer into the strong winter regime. Consistent with previous studies in idealized models, these transitions result from a mean-flow feedback, because of which they are insensitive to the treatment of vertical diffusion of momentum. Overall, the results corroborate previous findings for perpetual on-equatorial insolation. They demonstrate that an appropriate description of dry Hadley circulations, in particular their strength, needs to incorporate the vertical momentum transport by dry convection, a process that is neglected in most dry theories and idealized models. An improved estimate of the strength of the Snowball Earth Hadley circulation will also help to better constrain the climate of a possible Neoproterozoic Snowball Earth and its deglaciation threshold.

  9. Effect of circulation on wastewater treatment by Lemna gibba and Lemna minor (floating aquatic macrophytes).

    PubMed

    Demirezen Yilmaz, Dilek; Akbulut, Hatice

    2011-01-01

    In this study, laboratory tests were performed in order to examine growth characteristics of floating aquatic macrophytes (Lemna gibba and Lemna minor) in the presence of wastewater with circulation. The results showed that circulation of the waste water enhanced the kinetics of the process, as compared to the control systems. However, prolonged application of high circulation level had a different effect. In the presence of circulation with aquatic plants, there was additional 85.3-88.2% for BODs and 59.6-66.8% for COD decreases in the water quality indicators. In this study, the effectiveness of L. gibba and L. minor with circulation addition for the removal of four heavy metals (Pb, Ni, Mn, and Cu) from waste water was also investigated. Results from analysis confirmed the accumulation of different metals within the plant and a corresponding decrease of metals in the waste water. At the end of the study of circulation, L. gibba provided the metal removal for Cu, Pb, Ni, and Mn in the waste water as the ratio of 57%, 60%, 60%, and 62%, respectively. In this context, the best results were obtained when the action of L. gibba and L. minor plants, was combined with that of circulation. It is shown that in the presence of L. gibba and L. minor plants that are supplemented with circulation, the national standards of biochemical oxygen demand (BOD5) 27-33 mgL(-1) and chemical oxygen demand (COD) 62-78 mgL(-1) for L. minor and L. gibba, respectively, were reached after treatment. The new results can be used for design calculations regarding expected removal of pollutants by aquatic floating plants.

  10. An Oceanic General Circulation Model (OGCM) investigation of the Red Sea circulation: 2. Three-dimensional circulation in the Red Sea

    NASA Astrophysics Data System (ADS)

    Sofianos, Sarantis S.; Johns, William E.

    2003-03-01

    The three-dimensional circulation of the Red Sea is studied using a set of Miami Isopycnic Coordinate Ocean Model (MICOM) simulations. The model performance is tested against the few available observations in the basin and shows generally good agreement with the main observed features of the circulation. The main findings of this analysis include an intensification of the along-axis flow toward the coasts, with a transition from western intensified boundary flow in the south to eastern intensified flow in the north, and a series of strong seasonal or permanent eddy-like features. Model experiments conducted with different forcing fields (wind-stress forcing only, surface buoyancy forcing only, or both forcings combined) showed that the circulation produced by the buoyancy forcing is stronger overall and dominates the wind-driven part of the circulation. The main circulation pattern is related to the seasonal buoyancy flux (mostly due to the evaporation), which causes the density to increase northward in the basin and produces a northward surface pressure gradient associated with the downward sloping of the sea surface. The response of the eastern boundary to the associated mean cross-basin geostrophic current depends on the stratification and β-effect. In the northern part of the basin this results in an eastward intensification of the northward surface flow associated with the presence of Kelvin waves while in the south the traditional westward intensification due to Rossby waves takes place. The most prominent gyre circulation pattern occurs in the north where a permanent cyclonic gyre is present that is involved in the formation of Red Sea Outflow Water (RSOW). Beneath the surface boundary currents are similarly intensified southward undercurrents that carry the RSOW to the sill to flow out of the basin into the Indian Ocean.

  11. NASA High-Reynolds Number Circulation Control Research - Overview of CFD and Planned Experiments

    NASA Technical Reports Server (NTRS)

    Milholen, W. E., II; Jones, Greg S.; Cagle, Christopher M.

    2010-01-01

    A new capability to test active flow control concepts and propulsion simulations at high Reynolds numbers in the National Transonic Facility at the NASA Langley Research Center is being developed. This technique is focused on the use of semi-span models due to their increased model size and relative ease of routing high-pressure air to the model. A new dual flow-path high-pressure air delivery station has been designed, along with a new high performance transonic sem -si pan wing model. The modular wind tunnel model is designed for testing circulation control concepts at both transonic cruise and low-speed high-lift conditions. The ability of the model to test other active flow control techniques will be highlighted. In addition, a new higher capacity semi-span force and moment wind tunnel balance has been completed and calibrated to enable testing at transonic conditions.

  12. Response to perturbations for granular flow in a hopper

    NASA Astrophysics Data System (ADS)

    Wambaugh, John F.; Behringer, Robert P.; Matthews, John V.; Gremaud, Pierre A.

    2007-11-01

    We experimentally investigate the response to perturbations of circular symmetry for dense granular flow inside a three-dimensional right-conical hopper. These experiments consist of particle tracking velocimetry for the flow at the outer boundary of the hopper. We are able to test commonly used constitutive relations and observe granular flow phenomena that we can model numerically. Unperturbed conical hopper flow has been described as a radial velocity field with no azimuthal component. Guided by numerical models based upon continuum descriptions, we find experimental evidence for secondary, azimuthal circulation in response to perturbation of the symmetry with respect to gravity by tilting. For small perturbations we can discriminate between constitutive relations, based upon the agreement between the numerical predictions they produce and our experimental results. We find that the secondary circulation can be suppressed as wall friction is varied, also in agreement with numerical predictions. For large tilt angles we observe the abrupt onset of circulation for parameters where circulation was previously suppressed. Finally, we observe that for large tilt angles the fluctuations in velocity grow, independent of the onset of circulation.

  13. The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

    PubMed Central

    Yuruk, Koray; Bezemer, Rick; Euser, Mariska; Milstein, Dan M.J.; de Geus, Hilde H.R.; Scholten, Evert W.; de Mol, Bas A.J.M.; Ince, Can

    2012-01-01

    OBJECTIVES To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery using conventional extracorporeal circulation systems has been associated with significantly reduced microcirculatory perfusion, but it remains unknown whether this could be prevented by an mECC system. Here, we aimed to test the hypothesis that microcirculatory perfusion decreases with the use of a conventional extracorporeal circulation system and would be preserved with the use of an miniaturized extracorporeal circulation system. METHODS Microcirculatory density and perfusion were assessed using sublingual side stream dark-field imaging in patients undergoing on-pump coronary artery bypass graft (CABG) surgery before, during and after the use of either a conventional extracorporeal circulation system (n = 10) or a miniaturized extracorporeal circulation system (n = 10). In addition, plasma neutrophil gelatinase-associated lipocalin and creatinine levels and creatinine clearance were assessed up to 5 days post-surgery to monitor renal function. RESULTS At the end of the CPB, one patient in the miniaturized extracorporeal circulation-treated group and five patients in the conventional extracorporeal circulation-treated group received one bag of packed red blood cells (300 ml). During the CPB, the haematocrit and haemoglobin levels were slightly higher in the miniaturized extracorporeal circulation-treated patients compared with the conventional extracorporeal circulation-treated patients (27.7 ± 3.3 vs 24.7 ± 2.0%; P = 0.03; and 6.42 ± 0.75 vs 5.41 ± 0.64 mmol/l; P < 0.01). The density of perfused vessels with a diameter <25 µm (i.e. perfused vessel density) decreased slightly in the conventional extracorporeal circulation-treated group from 16.4 ± 3.8 to 12.8 ± 3.3 mm/mm2 (P < 0.01) and remained stable in the miniaturized extracorporeal circulation-treated group (16.3 ± 2.7 and 15.2 ± 2.9 mm/mm2 before and during the pump, respectively). Plasma neutrophil gelatinase-associated lipocalin levels were increased following the use of extracorporeal circulation in both groups, and no differences were observed between the groups. Plasma creatinine levels and creatinine clearance were not affected by CABG surgery or CPB. CONCLUSIONS The results from this relatively small study suggest that the use of the miniaturized extracorporeal circulation system is associated with a statistically significant (but clinically insignificant) reduction in haemodilution and microcirculatory hypoperfusion compared with the use of the conventional extracorporeal circulation system. PMID:22700685

  14. Development and Characterization of the Bonding and Integration Technologies Needed for Fabricating Silicon Carbide Based Injector Components

    NASA Technical Reports Server (NTRS)

    Halbig,Michael C.; Singh, Mrityunjay

    2008-01-01

    Advanced ceramic bonding and integration technologies play a critical role in the fabrication and application of silicon carbide based components for a number of aerospace and ground based applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. Ceramic to ceramic diffusion bonding and ceramic to metal brazing technologies are being developed for this injector application. For the diffusion bonding technology, titanium interlayers (coatings and foils) were used to aid in the joining of silicon carbide (SiC) substrates. The influence of such variables as surface finish, interlayer thickness, and processing time were investigated. Electron microprobe analysis was used to identify the reaction formed phases. In the diffusion bonds, an intermediate phase, Ti5Si3Cx, formed that is thermally incompatible in its thermal expansion and caused thermal stresses and cracking during the processing cool-down. Thinner interlayers of pure titanium and/or longer processing times resulted in an optimized microstructure. Tensile tests on the joined materials resulted in strengths of 13-28 MPa depending on the SiC substrate material. Nondestructive evaluation using ultrasonic immersion showed well formed bonds. For the joining technology of brazing Kovar fuel tubes to silicon carbide, preliminary development of the joining approach has begun. Various technical issues and requirements for the injector application are addressed.

  15. Microcomputer based controller for the Langley 0.3-meter Transonic Cryogenic Tunnel

    NASA Technical Reports Server (NTRS)

    Balakrishna, S.; Kilgore, W. Allen

    1989-01-01

    Flow control of the Langley 0.3-meter Transonic Cryogenic Tunnel (TCT) is a multivariable nonlinear control problem. Globally stable control laws were generated to hold tunnel conditions in the presence of geometrical disturbances in the test section and precisely control the tunnel states for small and large set point changes. The control laws are mechanized as four inner control loops for tunnel pressure, temperature, fan speed, and liquid nitrogen supply pressure, and two outer loops for Mach number and Reynolds number. These integrated control laws have been mechanized on a 16-bit microcomputer working on DOS. This document details the model of the 0.3-m TCT, control laws, microcomputer realization, and its performance. The tunnel closed loop responses to small and large set point changes were presented. The controller incorporates safe thermal management of the tunnel cooldown based on thermal restrictions. The controller was shown to provide control of temperature to + or - 0.2K, pressure to + or - 0.07 psia, and Mach number to + or - 0.002 of a given set point during aerodynamic data acquisition in the presence of intrusive geometrical changes like flexwall movement, angle-of-attack changes, and drag rake traverse. The controller also provides a new feature of Reynolds number control. The controller provides a safe, reliable, and economical control of the 0.3-m TCT.

  16. Performance of the supercritical helium cooling loop for the JET divertor cryopump

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Obert, W.; Mayaux, C.; Barth, K.

    1996-12-31

    A supercritical helium cooling loop for the two JET divertor cryopumps has been tested, commissioned and is operational practically uninterrupted for over one year. Operation experience under a number of different boundary and transient conditions have been obtained. The flow of the supercritical helium (6 g/s, 2.7 bar) is driven by the main compressor of the JET helium refrigerator passing a heat exchanger where it is subcooled to 4.1 K before entering the two cryopumps which are an assembly of two 60 m long and 20 mm diameter corrugated stainless steel tubes. By using a dedicated cold ejector which ismore » driven by the main flow and where the expansion from 12 bar to 2.7 bar takes place increases the flow of supercritical helium up to {approximately}17 g/s. The steady state thermal load to the cooling loop of the cryopump is < 80 W but during transient conditions in particular due to nuclear heating in the active phase of JET considerably higher transient heat loads can be accepted by the loop. Details about the steady state and transient thermal conditions as well as the cooldown and warm up behavior of the loop and the interaction of the supercritical loop with the operation of other plant equipment will be discussed in the paper.« less

  17. Moisture-Induced Alumina Scale Spallation: The Hydrogen Factor

    NASA Technical Reports Server (NTRS)

    Smialek, James L.

    2009-01-01

    For some time our community has been concerned with interfacial spallation of protective alumina scales, not just upon immediate cooldown, but as a time-delayed phenomenon. Moisture-induced delayed spallation (MIDS) and desktop spallation (DTS) of TBC's refer to this process. It is most apparent for relatively adherent alumina scales that have survived cool down in a dry environment, built up considerable thickness and strain energy, and have been somewhat damaged, such as by cyclic oxidation cracking. Indeed, a "sweet zone" can be defined that maximizes the observed effect as a function of all the relevant factors. Moisture has been postulated to serve as a source of interfacial hydrogen embrittlement derived from reaction with aluminum in the alloy at an exposed interface. The purpose of this monograph is to trace the close analogy of this phenomenon to other hydrogen effects, such as embrittlement of aluminides and blistering of alloys and anodic alumina films. A formalized, top-down, logic tree structure is presented as a guide to this discussion. A theoretical basis for interfacial weakening by hydrogen is first cited, as are demonstrations of hydrogen as a reaction product or detected interfacial species. Further support is provided by critical experiments that produce the same moisture effect, but by isolating hydrogen from other potential causative factors. These experiments include tests in H2-containing atmospheres or cathodic hydrogen charging.

  18. Linear-drive cryocoolers for the Department of Defense standard advanced dewar assembly (SADA)

    NASA Astrophysics Data System (ADS)

    Tate, Garin S.

    2005-05-01

    The Standard Advanced Dewar Assembly (SADA) is the critical module in the Department of Defense (DoD) standardization of scanning second-generation thermal imaging systems. The DoD has established a family of SADAs to fulfill a range of performance requirements for various platforms. The SADA consists of the Infrared Focal Plane Array (IRFPA), Dewar, Command & Control Electronics (C&CE), and the cryogenic cooler, and is used in platforms such as the Apache helicopter, the M1A2 Abrams main battle tank, the M2 Bradley Infantry Fighting Vehicle, and the Javelin Command Launch Unit (CLU). In support of the family of SADAs, the DoD defined a complementary family of tactical linear drive cryocoolers. The Stirling cycle linear drive cryocoolers are utilized to cool the Infrared Focal Plane Arrays (IRFPAs) in the SADAs. These coolers are required to have low input power, a quick cool-down time, low vibration output, low audible noise, and a higher reliability than currently fielded rotary coolers. These coolers must also operate in a military environment with its inherent high vibration level and temperature extremes. This paper will (1) outline the characteristics of each cryocooler, (2) present the status and results of qualification tests, (3) present the status of production efforts, and (4) present the status of efforts to increase linear drive cooler reliability.

  19. Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype.

    PubMed

    Herbst, Daniel P

    2014-09-01

    Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient's systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependent t tests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set at p < .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26-33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique.

  20. Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype

    PubMed Central

    Herbst, Daniel P.

    2014-01-01

    Abstract: Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient’s systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependent t tests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set at p < .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26–33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique. PMID:26357790

  1. PHISICS/RELAP5-3D RESULTS FOR EXERCISES II-1 AND II-2 OF THE OECD/NEA MHTGR-350 BENCHMARK

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strydom, Gerhard

    2016-03-01

    The Idaho National Laboratory (INL) Advanced Reactor Technologies (ART) High-Temperature Gas-Cooled Reactor (HTGR) Methods group currently leads the Modular High-Temperature Gas-Cooled Reactor (MHTGR) 350 benchmark. The benchmark consists of a set of lattice-depletion, steady-state, and transient problems that can be used by HTGR simulation groups to assess the performance of their code suites. The paper summarizes the results obtained for the first two transient exercises defined for Phase II of the benchmark. The Parallel and Highly Innovative Simulation for INL Code System (PHISICS), coupled with the INL system code RELAP5-3D, was used to generate the results for the Depressurized Conductionmore » Cooldown (DCC) (exercise II-1a) and Pressurized Conduction Cooldown (PCC) (exercise II-2) transients. These exercises require the time-dependent simulation of coupled neutronics and thermal-hydraulics phenomena, and utilize the steady-state solution previously obtained for exercise I-3 of Phase I. This paper also includes a comparison of the benchmark results obtained with a traditional system code “ring” model against a more detailed “block” model that include kinetics feedback on an individual block level and thermal feedbacks on a triangular sub-mesh. The higher spatial fidelity that can be obtained by the block model is illustrated with comparisons of the maximum fuel temperatures, especially in the case of natural convection conditions that dominate the DCC and PCC events. Differences up to 125 K (or 10%) were observed between the ring and block model predictions of the DCC transient, mostly due to the block model’s capability of tracking individual block decay powers and more detailed helium flow distributions. In general, the block model only required DCC and PCC calculation times twice as long as the ring models, and it therefore seems that the additional development and calculation time required for the block model could be worth the gain that can be obtained in the spatial resolution« less

  2. Female Hamster Preference for Odors is Not Regulated by Circulating Gonadal Hormones

    PubMed Central

    Eidson, Lori N.; Maras, Pamela M.; Epperson, Erin; Petrulis, Aras

    2009-01-01

    Proceptive and receptive behaviors of female rodents, such as golden hamsters, are often regulated by changes in circulating levels of ovarian hormones. However, less is known about how ovarian hormones might regulate female hamster’s attraction and preference for volatile odor from males. To evaluate this, we assessed female preference by recording investigation and proximity to male and female volatile odorants in a Y-maze across all days of the estrous cycle (Experiment 1 & 2) or following ovariectomy (Experiment 3). In Experiment 1, female subjects were tested four times, once on each day of their estrous cycle. Females showed a preference for male odors on diestrus day 1 and to a lesser degree on proestrus, but showed no preference on the day of behavioral estrus. Irrespective of cycle day, preference was apparent in the first few days of testing and disappeared by the fourth day, suggesting that repeated testing attenuated female preference. To avoid this problem, in Experiment 2 each animal was tested only on one day of the 4-day estrous cycle. Female preference for male volatile odors over those from females was observed on each day of their estrous cycle, including estrus. Moreover, following gonadectomy (Experiment 3) female hamsters still preferred male volatile odors to those of females. Taken together, this suggests that circulating levels of gonadal hormones do not influence preference for male volatile odors in female hamsters. PMID:17374544

  3. Development and Analysis of Cold Trap for Use in Fission Surface Power-Primary Test Circuit

    NASA Technical Reports Server (NTRS)

    Wolfe, T. M.; Dervan, C. A.; Pearson, J. B.; Godfroy, T. J.

    2012-01-01

    The design and analysis of a cold trap proposed for use in the purification of circulated eutectic sodium potassium (NaK-78) loops is presented. The cold trap is designed to be incorporated into the Fission Surface Power-Primary Test Circuit (FSP-PTC), which incorporates a pumped NaK loop to simulate in-space nuclear reactor-based technology using non-nuclear test methodology as developed by the Early Flight Fission-Test Facility. The FSP-PTC provides a test circuit for the development of fission surface power technology. This system operates at temperatures that would be similar to those found in a reactor (500-800 K). By dropping the operating temperature of a specified percentage of NaK flow through a bypass containing a forced circulation cold trap, the NaK purity level can be increased by precipitating oxides from the NaK and capturing them within the cold trap. This would prevent recirculation of these oxides back through the system, which may help prevent corrosion.

  4. PROTEIN METABOLISM AND EXCHANGE AS INFLUENCED BY CONSTRICTION OF THE VENA CAVA

    PubMed Central

    McKee, Frank W.; Hyatt, Robert E.; Wilt, William G.; Tishkoff, Garson H.; Whipple, George H.

    1949-01-01

    Further studies of ascitic fluid production and related factors in dogs with constriction of the vena cava above the diaphragm are reported. Whole dog plasma given intravenously to such animals produces a rise in circulating plasma protein to normal levels, but increases the output of ascitic fluid with a loss of protein via the ascites equivalent to 72, 76, and 65 per cent respectively, of the injected protein. Forced ingestion of water in excess of the test animal's normal needs and desires produces no significant changes in the circulating plasma protein level or in ascitic fluid production. Amino acid growth mixtures given intravenously in distilled water cause weight loss, elevation of circulating plasma proteins, a slightly negative nitrogen balance, but no ascitic fluid production. Amino acid growth mixtures given intravenously in normal saline cause depression of the circulating plasma proteins, negative nitrogen balance, and significant ascitic fluid production. Ascitic fluid given intravenously to the test animals causes a marked depression of circulating plasma proteins, a marked increase in ascitic fluid production containing the equivalent of 116 and 98 per cent of the injected protein, and a negative nitrogen balance. Ascitic fluid given orally produces a marked depression of circulating plasma proteins, and a marked increase in ascitic fluid secretion, containing the equivalent of 66, 66, and 54 per cent respectively, of the ingested protein. Sodium chloride is a dominant factor in some of these experiments where abundant ascites production is recorded. Protein levels and intake are important, but take second place to sodium. Ascitic fluids show electrophoretic patterns which are almost identical to the plasma patterns. The A/G ratios are often equal in ascitic fluid and plasma, sometimes even lower in the ascitic fluid. This emphasizes the ease with which globulins pass cell or other membrane barriers in these experiments. PMID:18143588

  5. Liquid Biopsy in Non-Small Cell Lung Cancer

    PubMed Central

    Molina-Vila, Miguel A.; Mayo-de-las-Casas, Clara; Giménez-Capitán, Ana; Jordana-Ariza, Núria; Garzón, Mónica; Balada, Ariadna; Villatoro, Sergi; Teixidó, Cristina; García-Peláez, Beatriz; Aguado, Cristina; Catalán, María José; Campos, Raquel; Pérez-Rosado, Ana; Bertran-Alamillo, Jordi; Martínez-Bueno, Alejandro; Gil, María-de-los-Llanos; González-Cao, María; González, Xavier; Morales-Espinosa, Daniela; Viteri, Santiago; Karachaliou, Niki; Rosell, Rafael

    2016-01-01

    Liquid biopsy analyses are already incorporated in the routine clinical practice in many hospitals and oncology departments worldwide, improving the selection of treatments and monitoring of lung cancer patients. Although they have not yet reached its full potential, liquid biopsy-based tests will soon be as widespread as “standard” biopsies and imaging techniques, offering invaluable diagnostic, prognostic, and predictive information. This review summarizes the techniques available for the isolation and analysis of circulating free DNA and RNA, exosomes, tumor-educated platelets, and circulating tumor cells from the blood of cancer patients, presents the methodological challenges associated with each of these materials, and discusses the clinical applications of liquid biopsy testing in lung cancer. PMID:28066769

  6. Chicken egg yolk antibodies (IgY) for detecting circulating antigens of Schistosoma japonicum.

    PubMed

    Cai, Yu-Chun; Guo, Jian; Chen, Shao-Hong; Tian, Li-Guang; Steinmann, Peter; Chen, Mu-Xin; Li, Hao; Ai, Lin; Chen, Jia-Xu

    2012-09-01

    IgY isolated from egg yolk has been widely used in immunodiagnostic tests, including tests to detect circulating antigen (soluble egg antigen or SEA) of Schistosoma japonicum. A sandwich ELISA was established using a combination of anti-S. japonicum SEA-IgY polyclonal antibodies and IgM monoclonal antibodies. To explore sensitivity and specificity of the sandwich ELISA, serum samples from 43 patients infected with S. japonicum were tested. All acute cases and 91.3% of the chronic cases showed a positive reaction. Only 5% of the control sera from healthy persons gave a positive response. Cross-reactions with antibodies to nine other parasites were rare. The developed immunoassay is reasonably sensitive and specific. It could be used for field research and treatment efficacy assessments. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. A Formative Evaluation of Me Now, Unit I, Digestion and Circulation, Life Sciences for the Educable Mentally Handicapped Intermediate Grades (11-13 years).

    ERIC Educational Resources Information Center

    Robinson, James T.; Tolman, Richard R.

    In order to evaluate Unit I (Digestion and Circulation) of the Me Now series of Life Sciences for the Educable Mentally Handicapped, 139 students in an experimental group (mean IQ 72.04; mean CA 144.9 months) and 154 control subjects (mean IQ 70.2; mean CA 148.3 months) were pre- and post-tested following instruction in the Me Now series…

  8. The circulating transcriptome as a source of non-invasive cancer biomarkers: concepts and controversies of non-coding and coding RNA in body fluids

    PubMed Central

    Fernandez-Mercado, Marta; Manterola, Lorea; Larrea, Erika; Goicoechea, Ibai; Arestin, María; Armesto, María; Otaegui, David; Lawrie, Charles H

    2015-01-01

    The gold standard for cancer diagnosis remains the histological examination of affected tissue, obtained either by surgical excision, or radiologically guided biopsy. Such procedures however are expensive, not without risk to the patient, and require consistent evaluation by expert pathologists. Consequently, the search for non-invasive tools for the diagnosis and management of cancer has led to great interest in the field of circulating nucleic acids in plasma and serum. An additional benefit of blood-based testing is the ability to carry out screening and repeat sampling on patients undergoing therapy, or monitoring disease progression allowing for the development of a personalized approach to cancer patient management. Despite having been discovered over 60 years ago, the clear clinical potential of circulating nucleic acids, with the notable exception of prenatal diagnostic testing, has yet to translate into the clinic. The recent discovery of non-coding (nc) RNA (in particular micro(mi)RNAs) in the blood has provided fresh impetuous for the field. In this review, we discuss the potential of the circulating transcriptome (coding and ncRNA), as novel cancer biomarkers, the controversy surrounding their origin and biology, and most importantly the hurdles that remain to be overcome if they are really to become part of future clinical practice. PMID:26119132

  9. Effects of land cover change on the tropical circulation in a GCM

    NASA Astrophysics Data System (ADS)

    Jonko, Alexandra Karolina; Hense, Andreas; Feddema, Johannes Jan

    2010-09-01

    Multivariate statistics are used to investigate sensitivity of the tropical atmospheric circulation to scenario-based global land cover change (LCC), with the largest changes occurring in the tropics. Three simulations performed with the fully coupled Parallel Climate Model (PCM) are compared: (1) a present day control run; (2) a simulation with present day land cover and Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 greenhouse gas (GHG) projections; and (3) a simulation with SRES A2 land cover and GHG projections. Dimensionality of PCM data is reduced by projection onto a priori specified eigenvectors, consisting of Rossby and Kelvin waves produced by a linearized, reduced gravity model of the tropical circulation. A Hotelling T 2 test is performed on projection amplitudes. Effects of LCC evaluated by this method are limited to diabatic heating. A statistically significant and recurrent signal is detected for 33% of all tests performed for various combinations of parameters. Taking into account uncertainties and limitations of the present methodology, this signal can be interpreted as a Rossby wave response to prescribed LCC. The Rossby waves are shallow, large-scale motions, trapped at the equator and most pronounced in boreal summer. Differences in mass and flow fields indicate a shift of the tropical Walker circulation patterns with an anomalous subsidence over tropical South America.

  10. Dobrava Virus Carried by the Yellow-Necked Field Mouse Apodemus flavicollis, Causing Hemorrhagic Fever with Renal Syndrome in Romania

    PubMed Central

    Panculescu-Gatej, Raluca Ioana; Sirbu, Anca; Dinu, Sorin; Waldstrom, Maria; Heyman, Paul; Murariu, Dimitru; Petrescu, Angela; Szmal, Camelia; Oprisan, Gabriela; Lundkvist, Åke

    2014-01-01

    Abstract Hemorrhagic fever with renal syndrome (HFRS) has been confirmed by serological methods during recent years in Romania. In the present study, focus-reduction neutralization tests (FRNT) confirmed Dobrava hantavirus (DOBV) as the causative agent in some HFRS cases, but could not distinguish between DOBV and Saaremaa virus (SAAV) infections in other cases. DOBV was detected by a DOBV-specific TaqMan assay in sera of nine patients out of 22 tested. Partial sequences of the M genomic segment of DOBV were obtained from sera of three patients and revealed the circulation of two DOBV lineages in Romania. Investigation of rodents trapped in Romania found three DOBV-positive Apodemus flavicollis out of 83 rodents tested. Two different DOBV lineages were also detected in A. flavicollis as determined from partial sequences of the M and S genomic segments. Sequences of DOBV in A. flavicollis were either identical or closely related to the sequences obtained from the HFRS patients. The DOBV strains circulating in Romania clustered in two monophyletic groups, together with strains from Slovenia and the north of Greece. This is the first evidence for the circulation of DOBV in wild rodents and for a DOBV etiology of HFRS in Romania. PMID:24746107

  11. Dobrava virus carried by the yellow-necked field mouse Apodemus flavicollis, causing hemorrhagic fever with renal syndrome in Romania.

    PubMed

    Panculescu-Gatej, Raluca Ioana; Sirbu, Anca; Dinu, Sorin; Waldstrom, Maria; Heyman, Paul; Murariu, Dimitru; Petrescu, Angela; Szmal, Camelia; Oprisan, Gabriela; Lundkvist, Ake; Ceianu, Cornelia S

    2014-05-01

    Hemorrhagic fever with renal syndrome (HFRS) has been confirmed by serological methods during recent years in Romania. In the present study, focus-reduction neutralization tests (FRNT) confirmed Dobrava hantavirus (DOBV) as the causative agent in some HFRS cases, but could not distinguish between DOBV and Saaremaa virus (SAAV) infections in other cases. DOBV was detected by a DOBV-specific TaqMan assay in sera of nine patients out of 22 tested. Partial sequences of the M genomic segment of DOBV were obtained from sera of three patients and revealed the circulation of two DOBV lineages in Romania. Investigation of rodents trapped in Romania found three DOBV-positive Apodemus flavicollis out of 83 rodents tested. Two different DOBV lineages were also detected in A. flavicollis as determined from partial sequences of the M and S genomic segments. Sequences of DOBV in A. flavicollis were either identical or closely related to the sequences obtained from the HFRS patients. The DOBV strains circulating in Romania clustered in two monophyletic groups, together with strains from Slovenia and the north of Greece. This is the first evidence for the circulation of DOBV in wild rodents and for a DOBV etiology of HFRS in Romania.

  12. Carbon capture test unit design and development using amine-based solid sorbent

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Breault, Ronald W.; Spenik, James L.; Shadle, Lawrence J.

    This study presents the design and development of a reactor system and the subsequent modifications to evaluate an integrated process to scrub carbon dioxide (CO 2) from synthetic flue gas using amine based solid sorbents. The paper presents the initial system design and then discusses the various changes implemented to address the change in sorbent from a 180 μm Geldart group B material to a 115 μm Geldart group A material as well as issues discovered during experimental trials where the major obstacle in system operation was the ability to maintain a constant circulation of a solid sorbent stemming frommore » this change in sorbent material. The system primarily consisted of four fluid beds, through which an amine impregnated solid sorbent was circulated and adsorption, pre-heat, regeneration, and cooling processes occurred. Instrumentation was assembled to characterize thermal, hydrodynamic, and gas adsorption performance in this integrated unit. A series of shakedown tests were performed and the configuration altered to meet the needs of the sorbent performance and achieve desired target capture efficiencies. Finally, methods were identified, tested, and applied to continuously monitor critical operating parameters including solids circulation rate, adsorbed and desorbed CO 2, solids inventories, and pressures.« less

  13. Studies of heat source driven natural convection

    NASA Technical Reports Server (NTRS)

    Kulacki, F. A.; Nagle, M. E.; Cassen, P.

    1974-01-01

    Natural convection energy transport in a horizontal layer of internally heated fluid with a zero heat flux lower boundary, and an isothermal upper boundary, has been studied. Quantitative information on the time-mean temperature distribution and the fluctuating component of temperature about the mean temperature in steady turbulent convection are obtained from a small thermocouple inserted into the layer through the upper bounding plate. Data are also presented on the development of temperature at several vertical positions when the layer is subject to both a sudden increase and to a sudden decrease in power input. For changes of power input from zero to a value corresponding to a Rayleigh number much greater than the critical linear stability theory value, a slight hysteresis in temperature profiles near the upper boundary is observed between the heat-up and cool-down modes.

  14. Low-temperature overpressurization protection system setpoint analysis using RETRAN-02/MOD5 for Salem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dodson, R.J.; Feltus, M.A.

    The low-temperature overpressurization protection system (LTOPS) is designed to protect the reactor pressure vessel (RPV) from brittle failure during startup and cooldown maneuvers in Westinghouse pressurized water reactors. For the Salem power plants, the power-operated relief valves (PORVs) mitigate pressure increases above a setpoint where an operational startup transient may put the RPV in the embrittlement fracture zone. The Title 10, Part 50, Code of Federal Regulations Appendix G limit, given by plant technical specifications, conservatively bounds the maximum pressure allowed during those transients where the RPV can suffer brittle fracture (usually below 350{degrees}F). The Appendix G limit is amore » pressure versus temperature curve that is more restrictive at lower RPV temperatures and allows for higher pressures as the temperature approaches the upper bounding fracture temperature.« less

  15. Initial NIST AC QHR Measurements

    PubMed Central

    Cage, M. E.; Shields, S. H.; Jeffery, A.

    2004-01-01

    We demonstrate that dc quantized Hall resistance (dc QHR) guideline properties and dc and ac QHR values can be measured without changing sample probe lead connections at the QHR device, and report ac QHR values that converge to the dc QHR value when using four-terminal-pair ac QHR measurements. This was accomplished during one cooldown using single-series and quadruple-series connections outside the sample probe. The QHR was measured from 0 Hz to 5500 Hz in 1:1 ratio at 20 µA to ±1 part in 107 uncertainties with a poor-quality QHR device. A good device would allow an order of magnitude smaller uncertainties over this frequency range. We exchanged positions of the QHR device and reference resistor in the bridge and remeasured the resistance ratios to remove dominant ac bridge effects. PMID:27366620

  16. An allowable cladding peak temperature for spent nuclear fuels in interim dry storage

    NASA Astrophysics Data System (ADS)

    Cha, Hyun-Jin; Jang, Ki-Nam; Kim, Kyu-Tae

    2018-01-01

    Allowable cladding peak temperatures for spent fuel cladding integrity in interim dry storage were investigated, considering hydride reorientation and mechanical property degradation behaviors of unirradiated and neutron irradiated Zr-Nb cladding tubes. Cladding tube specimens were heated up to various temperatures and then cooled down under tensile hoop stresses. Cool-down specimens indicate that higher heat-up temperature and larger tensile hoop stress generated larger radial hydride precipitation and smaller tensile strength and plastic hoop strain. Unirradiated specimens generated relatively larger radial hydride precipitation and plastic strain than did neutron irradiated specimens. Assuming a minimum plastic strain requirement of 5% for cladding integrity maintenance in interim dry storage, it is proposed that a cladding peak temperature during the interim dry storage is to keep below 250 °C if cladding tubes are cooled down to room temperature.

  17. Filling the Void: A Comprehensive Survey of the Intergalactic Medium at z 1 Using STIS/COS Archival Spectra

    NASA Astrophysics Data System (ADS)

    Khaire, Vikram

    2017-08-01

    There exists a large void in our understanding of the intergalactic medium (IGM) at z=0.5-1.5, spanning a significant cosmic time of 4 Gyr. This hole resulted from a paucity of near-UV QSO spectra, which were historically very expensive to obtain. However, with the advent of COS and the HST UV initiative, sufficient STIS/COS NUV spectra have finally become available, enabling the first statistical analyses. We propose a comprehensive study of the z 1 IGM using the Ly-alpha forest of 26 archival QSO spectra. This analysis will: (1) measure the distribution of HI absorbers to several percent precision down to log NHI < 13 to test our model of the IGM, and determine the extragalactic UV background (UVB) at that epoch; (2) measure the Ly-alpha forest power spectrum to 12%, providing another precision test of LCDM and our theory of the IGM; (3) measure the thermal state of the IGM, which reflects the balance of heating (photoheating, HI/HeII reionization) and cooling (Hubble expansion) of cosmic baryons, and directly verify the predicted cooldown of IGM gas after reionization for the first time; (4) generate high-quality reductions, coadds, and continuum fits that will be released to the public to enable other science cases. These results, along with our state-of-the-art hydrodynamical simulations, and theoretical models of the UVB, will fill the 4 Gyr hole in our understanding of the IGM. When combined with existing HST and ground-based data from lower and higher z, they will lead to a complete, empirical description of the IGM from HI reionization to the present, spanning more than 10 Gyr of cosmic history, adding substantially to Hubble's legacy of discovery on the IGM.

  18. Six-Month Lower Limb Aerobic Exercise Improves Physical Function in Young-Old, Old-Old, and Oldest-Old Adults.

    PubMed

    Cho, Chaeyoon; Han, Changwan; Sung, Misun; Lee, Chaewon; Kim, Minji; Ogawa, Yoshiko; Kohzuki, Masahiro

    2017-08-01

    The effect of aerobic exercise on physical function and mental health in various adult age groups (young-old, 65-74; old-old, 75-84; oldest-old, ≥ 85 years) is unclear. The aim of this study was to investigate the effects of the Kohzuki Exercise Program (KEP) on physical function and mental health in these age groups. The KEP consisted of 40-min supervised sessions 3 times per week for 6 months as follows: 5 min of warm-up, 30 min of lower limb aerobic exercise, and 5 min of cool-down. A total of 50 participants (22 young-old, 20 old-old, and 8 oldest-old) who participated in the KEP completed at least 88% of the sessions. In statistical analysis, 3 (group: oldest-old, old-old, young-old) × 2 (time: baseline and after 6 months) analyses of variance were used to determine if there were significant main and interaction effects. Significant interactions were probed using the post-hoc paired t test. The Short Physical Performance Battery (SPPB) score showed significant group × time interactions after 6 months (p = 0.031). In the post-hoc test, oldest-old (p < 0.001), old-old (p < 0.001), and young-old (p < 0.01) groups had significantly better physical function after 6 months. However, none of the mental health measures showed group × time interactions at 6-month. Our results suggest that a 6-month KEP led to improved physical function in oldest-old, old-old, and young-old adults. The KEP was effective for oldest-old adults in particular. The KEP exhibits good adherence, making it suitable for a wide age range in society.

  19. Effects of block copolymer properties on nanocarrier protection from in vivo clearance

    PubMed Central

    D’Addio, Suzanne M.; Saad, Walid; Ansell, Steven M.; Squiers, John J.; Adamson, Douglas; Herrera-Alonso, Margarita; Wohl, Adam R.; Hoye, Thomas R.; Macosko, Christopher W.; Mayer, Lawrence D.; Vauthier, Christine; Prud’homme, Robert K.

    2012-01-01

    Drug nanocarrier clearance by the immune system must be minimized to achieve targeted delivery to pathological tissues. There is considerable interest in finding in vitro tests that can predict in vivo clearance outcomes. In this work, we produce nanocarriers with dense PEG layers resulting from block copolymer-directed assembly during rapid precipitation. Nanocarriers are formed using block copolymers with hydrophobic blocks of polystyrene (PS), poly-ε-caprolactone (PCL), poly-D,L-lactide (PLA), or poly-lactide-co-glycolide (PLGA), and hydrophilic blocks of polyethylene glycol (PEG) with molecular weights from 1.5 kg/mol to 9 kg/mol. Nanocarriers with paclitaxel prodrugs are evaluated in vivo in Foxn1nu mice to determine relative rates of clearance. The amount of nanocarrier in circulation after 4 h varies from 10% to 85% of initial dose, depending on the block copolymer. In vitro complement activation assays are conducted in an effort to correlate the protection of the nanocarrier surface from complement binding and activation and in vivo circulation. Guidelines for optimizing block copolymer structure to maximize circulation of nanocarriers formed by rapid precipitation and directed assembly are proposed, relating to the relative size of the hydrophilic and hydrophobic block, the hydrophobicity of the anchoring block, the absolute size of the PEG block, and polymer crystallinity. The in vitro results distinguish between the poorly circulating PEG5k-PCL9k and the better circulating nanocarriers, but could not rank the better circulating nanocarriers in order of circulation time. Analysis of PEG surface packing on monodisperse 200 nm latex spheres indicates that the sizes of the hydrophobic PCL, PS, and PLA blocks are correlated with the PEG blob size, and possibly the clearance from circulation. Suggestions for next step in vitro measurements are made. PMID:22732478

  20. Modeling bronchial circulation with application to soluble gas exchange: description and sensitivity analysis.

    PubMed

    Bui, T D; Dabdub, D; George, S C

    1998-06-01

    The steady-state exchange of inert gases across an in situ canine trachea has recently been shown to be limited equally by diffusion and perfusion over a wide range (0.01-350) of blood solubilities (betablood; ml . ml-1 . atm-1). Hence, we hypothesize that the exchange of ethanol (betablood = 1,756 at 37 degrees C) in the airways depends on the blood flow rate from the bronchial circulation. To test this hypothesis, the dynamics of the bronchial circulation were incorporated into an existing model that describes the simultaneous exchange of heat, water, and a soluble gas in the airways. A detailed sensitivity analysis of key model parameters was performed by using the method of Latin hypercube sampling. The model accurately predicted a previously reported experimental exhalation profile of ethanol (R2 = 0.991) as well as the end-exhalation airstream temperature (34.6 degrees C). The model predicts that 27, 29, and 44% of exhaled ethanol in a single exhalation are derived from the tissues of the mucosa and submucosa, the bronchial circulation, and the tissue exterior to the submucosa (which would include the pulmonary circulation), respectively. Although the concentration of ethanol in the bronchial capillary decreased during inspiration, the three key model outputs (end-exhaled ethanol concentration, the slope of phase III, and end-exhaled temperature) were all statistically insensitive (P > 0.05) to the parameters describing the bronchial circulation. In contrast, the model outputs were all sensitive (P < 0.05) to the thickness of tissue separating the core body conditions from the bronchial smooth muscle. We conclude that both the bronchial circulation and the pulmonary circulation impact soluble gas exchange when the entire conducting airway tree is considered.

  1. Phase shift method to estimate solids circulation rate in circulating fluidized beds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ludlow, James Christopher; Panday, Rupen; Shadle, Lawrence J.

    2013-01-01

    While solids circulation rate is a critical design and control parameter in circulating fluidized bed (CFB) reactor systems, there are no available techniques to measure it directly at conditions of industrial interest. Cold flow tests have been conducted at NETL in an industrial scale CFB unit where the solids flow has been the topic of research in order to develop an independent method which could be applied to CFBs operating under the erosive and corrosive high temperatures and pressures of a coal fired boiler or gasifier. The dynamic responses of the CFB loop to modest modulated aeration flows in themore » return leg or standpipe were imposed to establish a periodic response in the unit without causing upset in the process performance. The resulting periodic behavior could then be analyzed with a dynamic model and the average solids circulation rate could be established. This method was applied to the CFB unit operated under a wide range of operating conditions including fast fluidization, core annular flow, dilute and dense transport, and dense suspension upflow. In addition, the system was operated in both low and high total solids inventories to explore the influence of inventory limiting cases on the estimated results. The technique was able to estimate the solids circulation rate for all transport circulating fluidized beds when operating above upper transport velocity, U{sub tr2}. For CFB operating in the fast fluidized bed regime (i.e., U{sub g}< U{sub tr2}), the phase shift technique was not successful. The riser pressure drop becomes independent of the solids circulation rate and the mass flow rate out of the riser does not show modulated behavior even when the riser pressure drop does.« less

  2. Cytologic characteristics of circulating epithelioid cells in pancreatic disease.

    PubMed

    Rosenbaum, Matthew W; Cauley, Christy E; Kulemann, Birte; Liss, Andrew S; Castillo, Carlos Fernandez-Del; Warshaw, Andrew L; Lillemoe, Keith D; Thayer, Sarah P; Pitman, Martha B

    2017-05-01

    Circulating epithelioid cells (CECs), also known as circulating tumor, circulating cancer, circulating epithelial, or circulating nonhematologic cells, are a prognostic factor in various malignancies that can be isolated via various protocols. In the current study, the authors analyzed the cytomorphologic characteristics of CECs isolated by size in a cohort of patients with benign and malignant pancreatic diseases to determine whether cytomorphological features could predict CEC origin. Blood samples were collected from 9 healthy controls and 171 patients with pancreatic disease who were presenting for surgical evaluation before treatment. Blood was processed with the ScreenCell size-based filtration device. Evaluable CECs were analyzed in a blinded fashion for cytomorphologic characteristics, including cellularity; nucleoli; nuclear size, irregularity, variability, and hyperchromasia; and nuclear-to-cytoplasmic ratio. Statistical differences between variables were analyzed via the Fisher exact test. No CECs were identified among the 9 normal healthy controls. Of the 115 patients with CECs (positive or suspicious for), 25 had nonmalignant disease and 90 had malignancy. There were no significant differences in any of the cytologic criteria noted between groups divided by benign versus malignant, neoplastic versus nonneoplastic, or pancreatic ductal adenocarcinoma versus neuroendocrine tumor. CECs were observed in patients with malignant and nonmalignant pancreatic disease, but not in healthy controls. There were no morphologic differences observed between cells from different pancreatic diseases, suggesting that numerous conditions may be associated with CECs in the circulation and that care must be taken not to overinterpret cells identified by cytomorphology as indicative of circulating tumor cells of pancreatic cancer. Additional studies are required to determine the origin and clinical significance of these cells. Cancer Cytopathol 2017;125:332-340. © 2017 American Cancer Society. © 2017 American Cancer Society.

  3. Increased plasma levels of circulating cell-free mitochondrial DNA in suicide attempters: associations with HPA-axis hyperactivity

    PubMed Central

    Lindqvist, D; Fernström, J; Grudet, C; Ljunggren, L; Träskman-Bendz, L; Ohlsson, L; Westrin, Å

    2016-01-01

    Preclinical data suggest that chronic stress may cause cellular damage and mitochondrial dysfunction, potentially leading to the release of mitochondrial DNA (mtDNA) into the bloodstream. Major depressive disorder has been associated with an increased amount of mtDNA in leukocytes from saliva samples and blood; however, no previous studies have measured plasma levels of free-circulating mtDNA in a clinical psychiatric sample. In this study, free circulating mtDNA was quantified in plasma samples from 37 suicide attempters, who had undergone a dexamethasone suppression test (DST), and 37 healthy controls. We hypothesized that free circulating mtDNA would be elevated in the suicide attempters and would be associated with hypothalamic–pituitary–adrenal (HPA)-axis hyperactivity. Suicide attempters had significantly higher plasma levels of free-circulating mtDNA compared with healthy controls at different time points (pre- and post-DST; all P-values<2.98E−12, Cohen's d ranging from 2.55 to 4.01). Pre-DST plasma levels of mtDNA were positively correlated with post-DST cortisol levels (rho=0.49, P<0.003). Suicide attempters may have elevated plasma levels of free-circulating mtDNA, which are related to impaired HPA-axis negative feedback. This peripheral index is consistent with an increased cellular or mitochondrial damage. The specific cells and tissues contributing to plasma levels of free-circulating mtDNA are not known, as is the specificity of this finding for suicide attempters. Future studies are needed in order to better understand the relevance of increased free-circulating mtDNA in relation to the pathophysiology underlying suicidal behavior and depression. PMID:27922635

  4. Aneurysms of the anterior and posterior cerebral circulation: comparison of the morphometric features.

    PubMed

    Tykocki, Tomasz; Kostkiewicz, Bogusław

    2014-09-01

    Intracranial aneurysms (IAs) located in the posterior circulation are considered to have higher annual bleed rates than those in the anterior circulation. The aim of the study was to compare the morphometric factors differentiating between IAs located in the anterior and posterior cerebral circulation. A total number of 254 IAs diagnosed between 2009 and 2012 were retrospectively analyzed. All patients qualified for diagnostic, three-dimensional rotational angiography. IAs were assigned to either the anterior or posterior cerebral circulation subsets for the analysis. Means were compared with a t-test. The univariate and stepwise logistic regression analyses were used to determine the predictors of morphometric differences between the groups. For the defined predictors, ROC (receiver-operating characteristic) curves and interactive dot diagrams were calculated with the cutoff values of the morphometric factors. The number of anterior cerebral circulation IAs was 179 (70.5 %); 141 (55.5 %) aneurysms were ruptured. Significant differences between anterior and posterior circulation IAs were found for: the parent artery size (5.08 ± 1.8 mm vs. 3.95 ± 1.5 mm; p < 0.05), size ratio (2.22 ± 0.9 vs. 3.19 ± 1.8; p < 0.045) and aspect ratio (AR) (1.91 ± 0.8 vs. 2.75 ± 1.8; p = 0.02). Predicting factors differentiating anterior and posterior circulation IAs were: the AR (OR = 2.20; 95 % CI 1.80-270; Is 270 correct or should it be 2.70 and parent artery size (OR = 0.44; 95 % CI 0.38-0.54). The cutoff point in the ROC curve was 2.185 for the AR and 4.89 mm for parent artery size. Aspect ratio and parent artery size were found to be predictive morphometric factors in differentiating between anterior and posterior cerebral IAs.

  5. Sex differences in visuospatial abilities persist during induced hypogonadism

    PubMed Central

    Guerrieri, Gioia M.; Wakim, Paul G.; Keenan, P.A.; Schenkel, Linda A; Berlin, Kate; Gibson, Carolyn J.; Rubinow, David R.; Schmidt, Peter J.

    2016-01-01

    Background Despite well-established sex differences in the performance on tests of several cognitive domains (e.g., visuospatial ability), few studies in humans have evaluated if these sex differences are evident both in the presence of circulating sex hormones and during sex steroid hormonal suppression. Sex differences identified in the relative absence of circulating levels of estradiol and testosterone suggest that differences in brain structure or function exist independent of current hormonal environment and are more likely a reflection of differing developmental exposures and/or genetic substrates. Objective To evaluate cognitive performance in healthy eugonadal men and women before and again during GnRH agonist-induced hypogonadism. Methods Men (n = 16) and women (n = 15) without medical or psychiatric illness were matched for IQ. Cognitive tests were performed at baseline (when eugonadal) and after 68 weeks of GnRH agonist-induced gonadal suppression. The test batteries included measures of verbal and spatial memory, spatial ability, verbal fluency, motor speed/dexterity, and attention/concentration. Data were analyzed using repeated-measures models. Results During both eugonadism and hypogonadism, men performed significantly better than women on several measures of visuospatial performance including mental rotation, line orientation, Money Road Map, Porteus maze, and complex figure drawing. Although some test performances showed an effect of hormone treatment, the majority of these differences reflected an improved performance during hypogonadism compared with baseline (and probably reflected practice effects). Conclusion The well-documented male advantage in visuospatial performance, which we observed during eugonadal conditions, was maintained in the context of short-term suppression of gonadal function in both men and women. These findings suggest that, in humans, sex differences in visuospatial performance are not merely dependent on differences in the current circulating sex steroid environment. Thus sex differences in visuospatial performance in adulthood could reflect early developmental effects of sex steroid exposure or other environmental exposures differing across the sexes as our data confirm that these differences are independent of circulating estradiol or testosterone levels in men and women. PMID:26719236

  6. Sex differences in visuospatial abilities persist during induced hypogonadism.

    PubMed

    Guerrieri, Gioia M; Wakim, Paul G; Keenan, P A; Schenkel, Linda A; Berlin, Kate; Gibson, Carolyn J; Rubinow, David R; Schmidt, Peter J

    2016-01-29

    Despite well-established sex differences in the performance on tests of several cognitive domains (e.g., visuospatial ability), few studies in humans have evaluated if these sex differences are evident both in the presence of circulating sex hormones and during sex steroid hormonal suppression. Sex differences identified in the relative absence of circulating levels of estradiol and testosterone suggest that differences in brain structure or function exist independent of current hormonal environment and are more likely a reflection of differing developmental exposures and/or genetic substrates. To evaluate cognitive performance in healthy eugonadal men and women before and again during GnRH agonist-induced hypogonadism. Men (n=16) and women (n=15) without medical or psychiatric illness were matched for IQ. Cognitive tests were performed at baseline (when eugonadal) and after 6-8 weeks of GnRH agonist-induced gonadal suppression. The test batteries included measures of verbal and spatial memory, spatial ability, verbal fluency, motor speed/dexterity, and attention/concentration. Data were analyzed using repeated-measures models. During both eugonadism and hypogonadism, men performed significantly better than women on several measures of visuospatial performance including mental rotation, line orientation, Money Road Map, Porteus maze, and complex figure drawing. Although some test performances showed an effect of hormone treatment, the majority of these differences reflected an improved performance during hypogonadism compared with baseline (and probably reflected practice effects). The well-documented male advantage in visuospatial performance, which we observed during eugonadal conditions, was maintained in the context of short-term suppression of gonadal function in both men and women. These findings suggest that, in humans, sex differences in visuospatial performance are not merely dependent on differences in the current circulating sex steroid environment. Thus sex differences in visuospatial performance in adulthood could reflect early developmental effects of sex steroid exposure or other environmental exposures differing across the sexes as our data confirm that these differences are independent of circulating estradiol or testosterone levels in men and women. Published by Elsevier Ltd.

  7. Detection and Characterization of Circulating Tumor Associated Cells in Metastatic Breast Cancer.

    PubMed

    Mu, Zhaomei; Benali-Furet, Naoual; Uzan, Georges; Znaty, Anaëlle; Ye, Zhong; Paolillo, Carmela; Wang, Chun; Austin, Laura; Rossi, Giovanna; Fortina, Paolo; Yang, Hushan; Cristofanilli, Massimo

    2016-09-30

    The availability of blood-based diagnostic testing using a non-invasive technique holds promise for real-time monitoring of disease progression and treatment selection. Circulating tumor cells (CTCs) have been used as a prognostic biomarker for the metastatic breast cancer (MBC). The molecular characterization of CTCs is fundamental to the phenotypic identification of malignant cells and description of the relevant genetic alterations that may change according to disease progression and therapy resistance. However, the molecular characterization of CTCs remains a challenge because of the rarity and heterogeneity of CTCs and technological difficulties in the enrichment, isolation and molecular characterization of CTCs. In this pilot study, we evaluated circulating tumor associated cells in one blood draw by size exclusion technology and cytological analysis. Among 30 prospectively enrolled MBC patients, CTCs, circulating tumor cell clusters (CTC clusters), CTCs of epithelial-mesenchymal transition (EMT) and cancer associated macrophage-like cells (CAMLs) were detected and analyzed. For molecular characterization of CTCs, size-exclusion method for CTC enrichment was tested in combination with DEPArray™ technology, which allows the recovery of single CTCs or pools of CTCs as a pure CTC sample for mutation analysis. Genomic mutations of TP53 and ESR1 were analyzed by targeted sequencing on isolated 7 CTCs from a patient with MBC. The results of genomic analysis showed heterozygous TP53 R248W mutation from one single CTC and pools of three CTCs, and homozygous TP53 R248W mutation from one single CTC and pools of two CTCs. Wild-type ESR1 was detected in the same isolated CTCs. The results of this study reveal that size-exclusion method can be used to enrich and identify circulating tumor associated cells, and enriched CTCs were characterized for genetic alterations in MBC patients, respectively.

  8. Levels of free fatty acids (FFA) are associated with insulin resistance but do not explain the relationship between adiposity and insulin resistance in Hispanic Americans: the IRAS Family Study.

    PubMed

    Miller, Melissa R; Pereira, Rocio I; Langefeld, Carl D; Lorenzo, Carlos; Rotter, Jerome I; Chen, Yii-Der Ida; Bergman, Richard N; Wagenknecht, Lynne E; Norris, Jill M; Fingerlin, Tasha E

    2012-09-01

    We investigated whether free fatty acids (FFA) mediate the association between adiposity and insulin resistance in the Hispanic-American families of the Insulin Resistance Atherosclerosis Family Study. In 815 Hispanic individuals in the Insulin Resistance Atherosclerosis Family Study, we tested for association between the following: 1) levels of adiposity [body mass index (BMI), visceral and sc adipose tissue area (VAT and SAT)] and circulating levels of FFA; 2) levels of circulating FFA and insulin sensitivity (S(I)); and 3) levels of adiposity and S(I), additionally testing to see whether levels of FFA mediated or modified the relationship between adiposity and S(I.) After adjusting for age, sex, clinic site, and admixture, increasing levels of BMI, VAT, and SAT were weakly associated with increasing levels of circulating FFA (BMI: P = 0.024; VAT: P = 2.33 × 10(-3); SAT: P = 0.018; percent variation explained: ∼1.00%). Increasing levels of circulating FFA were associated with decreasing S(I) (P = 8.10 × 10(-11)). Increasing BMI, VAT, and SAT were also associated with decreasing S(I) (BMI: P = 4.98 × 10(-71); VAT: P = 1.48 × 10(-64); SAT: P = 4.21 × 10(-62)), but this relationship was not significantly mediated by FFA. VAT, but not BMI or SAT, interacts with levels of FFA to influence S(I) (P = 0.021). Although levels of circulating FFA are associated both with increasing adiposity and decreasing S(I), they do not appear to mediate the association between levels of adiposity and S(I) in this large cohort of Hispanic-Americans. These results may indicate that FFA contribute to insulin resistance independent of adiposity.

  9. Two Years After the Schmallenberg Virus Epidemic in the Netherlands: Does the Virus still Circulate?

    PubMed

    Veldhuis, A M B; Mars, M H; Roos, C A J; van Wuyckhuise, L; van Schaik, G

    2017-02-01

    Two years after the introduction of the Schmallenberg virus in north-western Europe, it is unknown whether the virus is still circulating in countries that were the first to be confronted with it. When the population-level immunity declines in Europe, reintroduction or the re-emergence of SBV in Europe might eventually result in an outbreak of similar magnitude of that seen in 2011-2012. The Netherlands was part of the primary outbreak region of SBV in 2011. The aim of this study was to determine whether SBV circulated amongst dairy herds in the Netherlands in 2013, and if so, to which extent. For this purpose, the presence of SBV-specific antibodies in naive cattle was investigated. A total of 394 dairy farms were sampled between October and December 2013 by collecting five serum samples per herd. Antibodies were detected in 1.1% [95% confidence interval (CI): 0.7-1.7)] of the animals. All seropositive animals were single reactors per herd and were at least 8 months old at sampling. As these results were inconclusive in demonstrating freedom of SBV circulation, a more in-depth investigation was initiated to provide more insight: an additional sample of 20 youngstock within the same age category (including the five initially sampled animals) was collected from 17 of the 21 positive herds and tested for SBV-specific antibodies. This resulted in 9 antibody-positive test results of 316 samples. Again, the positive samples were single reactors within the sample obtained from each farm, which is unlikely given the characteristics of SBV. Therefore, assuming the single reactors as false-positive, this survey showed with 95% confidence that the maximum possible prevalence of herds with SBV circulation in the Netherlands was <1% in 2013. © 2015 Blackwell Verlag GmbH.

  10. Serological Evidence of Lyssaviruses among Bats on Southwestern Indian Ocean Islands.

    PubMed

    Mélade, Julien; McCulloch, Stewart; Ramasindrazana, Beza; Lagadec, Erwan; Turpin, Magali; Pascalis, Hervé; Goodman, Steven M; Markotter, Wanda; Dellagi, Koussay

    2016-01-01

    We provide serological evidence of lyssavirus circulation among bats on southwestern Indian Ocean (SWIO) islands. A total of 572 bats belonging to 22 species were collected on Anjouan, Mayotte, La Réunion, Mauritius, Mahé and Madagascar and screened by the Rapid Fluorescent Focus Inhibition Test for the presence of neutralising antibodies against the two main rabies related lyssaviruses circulating on the African continent: Duvenhage lyssavirus (DUVV) and Lagos bat lyssavirus (LBV), representing phylogroups I and II, respectively. A total of 97 and 42 sera were able to neutralise DUVV and LBV, respectively. No serum neutralised both DUVV and LBV but most DUVV-seropositive bats (n = 32/220) also neutralised European bat lyssavirus 1 (EBLV-1) but not Rabies lyssavirus (RABV), the prototypic lyssavirus of phylogroup I. These results highlight that lyssaviruses belonging to phylogroups I and II circulate in regional bat populations and that the putative phylogroup I lyssavirus is antigenically closer to DUVV and EBLV-1 than to RABV. Variation between bat species, roost sites and bioclimatic regions were observed. All brain samples tested by RT-PCR specific for lyssavirus RNA were negative.

  11. A potential flight evaluation of an upper-surface-blowing/circulation-control-wing concept

    NASA Technical Reports Server (NTRS)

    Riddle, Dennis W.; Eppel, Joseph C.

    1987-01-01

    The technology data base for powered lift aircraft design has advanced over the last 15 years. NASA's Quiet Short Haul Research Aircraft (QSRA) has provided a flight verification of upper surface blowing (USB) technology. The A-6 Circulation Control Wing flight demonstration aricraft has provide data for circulation control wing (CCW) technology. Recent small scale wind tunnel model tests and full scale static flow turning test have shown the potential of combining USB with CCW technology. A flight research program is deemed necessary to fully explore the performance and control aspects of CCW jet substitution for the mechanical USB Coanda flap. The required hardware design would also address questions about the development of flight weight ducts and CCW jets and the engine bleed-air capabilities vs requirements. NASA's QSRA would be an optimum flight research vehicle for modification to the USB/CCW configuration. The existing QSRA data base, the design simplicity of the QSRA wing trailing edge controls, availability of engine bleed-air, and the low risk, low cost potential of the suggested program is discussed.

  12. Rabies Virus Exposure of Brazilian Free-ranging Wildlife from Municipalities without Clinical Cases in Humans or in Terrestrial Wildlife.

    PubMed

    Marcelo Azevedo de Paula Antunes, João; de Castro Demoner, Larissa; Morosini de Andrade Cruvinel, Tatiana; Paula Kataoka, Ana; Fátima Alves Martorelli, Luzia; Puglia Machado, Gustavo; Megid, Jane

    2017-07-01

    Rabies is a zoonosis that causes thousands of animal and human deaths worldwide. Serological studies provide information concerning rabies virus circulation among animals and humans. We evaluated the circulation of the rabies virus in wildlife in nine municipalities of São Paulo State, Brazil. We took blood samples from 27 terrestrial animals of nine different mammalian species in locations without cases of rabies in human and wild terrestrial mammals. Sera were tested with the use of the rapid fluorescent focus inhibition test (RFFIT) for the detection of rabies virus-neutralizing antibodies (RVNA). The RFFIT was positive in 100% of the samples, with many (81.48%) showing protective titer levels (>0.5 IU/mL) with other samples (18.52%) showing titers representing exposure (<0.5 IU/mL). We report RVNA in novel species (e.g., Alouatta caraya and Tapyrus terrestris). Wild animals were exposed to rabies virus in municipalities without a history of human rabies cases, which demonstrated a need for research to understand the role of these animals in the circulation and transmission of the disease.

  13. Objective assessment of biomagnetic devices and alternative clinical therapies using infrared thermal imaging

    NASA Astrophysics Data System (ADS)

    Rockley, Graham J.

    2001-03-01

    The overwhelming introduction of magnetic devices and other alternative therapies into the health care market prompts the need for objective evaluation of these techniques through the use of infrared thermal imaging. Many of these therapies are reported to promote the stimulation of blood flow or the relief of pain conditions. Infrared imaging is an efficient tool to assess such changes in the physiological state. Therefore, a thermal imager can help document and substantiate whether these therapies are in fact providing an effective change to the local circulation. Thermal images may also indicate whether the change is temporary or sustained. As a specific case example, preliminary findings will be presented concerning the use of magnets and the effect they have on peripheral circulation. This will include a discussion of the recommended protocols for this type of infrared testing. This test model can be applied to the evaluation of other devices and therapeutic procedures which are reputed to affect circulation such as electro acupuncture, orthopedic footwear and topical ointments designed to relieve pain or inflammation.

  14. ENDEMIC ORTHOPOXVIRUS CIRCULATING IN PROCYONIDS IN MEXICO.

    PubMed

    Gallardo-Romero, Nadia F; Aréchiga-Ceballos, Nidia; Emerson, Ginny L; Martínez-Martínez, Flor O; Doty, Jeffrey B; Nakazawa, Yoshinori J; Rendón-Franco, Emilio; Muñoz-García, Claudia I; Villanueva-García, Claudia; Ramírez-Cid, Citlali; Gama-Campillo, Lilia M; Gual-Sill, Fernando; Aguilar-Setién, Álvaro; Carroll, Darin S

    2016-07-01

    Limited serosurveillance studies suggested that orthopoxviruses (OPXV) are widespread in the US (e.g., Raccoonpox virus, Skunkpox virus, Volepox virus) and Brazil (Vaccinia virus); however, their animal reservoir(s) remain unconfirmed. Mexican mammal diversity includes several species related to those in which evidence for OPXV infections has been found (Oryzomys, Peromyscus, Microtus, and Procyonidae). The presence of these groups of mammals in Mexico and the evidence of their possible involvement in the maintenance of OPXV in nature suggest the same or similar OPXV are circulating in Mexico. We tested 201 sera from 129 procyonids via modified enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) to estimate OPXV antibody prevalence in these animals. We detected a prevalence of 16.67% in Nasua narica (white-nosed coati), 35% in Procyon lotor (raccoon), and 30.4% in Bassariscus astutus (ring-tailed cat) when tested by either ELISA or WB. Western blot results presented protein bands consistent with the size of some OPXV immunodominant bands (14, 18, 32, 36, and 62 kDa). These results support the hypothesis that OPXV circulate in at least three genera of Procyonidae in Central and Southeast Mexico.

  15. Prevalence of diatom frustules in non-vegetarian foodstuffs and its implications in interpreting identification of diatom frustules in drowning cases.

    PubMed

    Yen, Law Yen; Jayaprakash, P T

    2007-07-20

    Detection of diatom frustules in bone marrow (diatom test) is used for diagnosing ante-mortem drowning where the usual signs of drowning are not present in dead bodies recovered from water. However, controversies over the reliability of diatom test results are continuing. There have been indications on the possibilities of diatoms entering into systemic circulation from atmospheric air, food and drink. While diatoms have been demonstrated in the gut content of edible marine forms such as shrimps and clams, the present study, for the first time, provides empirical evidence on the prevalence as well as abundance of diatom frustules in the samples of cooked non-vegetarian foodstuffs that impend human consumption in Kelantan, Malaysia. It is found that 50 g each of cleaned and cooked prawns and of clams impending human consumption contain about 8360 and 29,054 diatom frustules, respectively. A person accustomed to prawn and clam food would be ingesting an estimated 2 million diatoms in a single year. Considering the suggestion that detection of five diatom frustules in 10 g of bone marrow would suffice for concluding drowning as mode of death, and the fact that there is yet no proof that diatom frustules do not enter into the human systemic circulation through the digestive tract, the estimated number of diatom frustules routinely ingested acquires significance since entry of a few of such ingested frustules into the systemic circulation can lead to false positive test results. The findings of this research raise two important issues: first, population based routine food related diatom ingestion requires to be estimated, and, second, studies have to be initiated to categorically prove or disprove the possibility of entry of diatom frustules into the systemic circulation via the digestive tract.

  16. Long-Term Heating to Improve Receiver Performance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Glatzmaier, Greg C.; Cable, Robert; Newmarker, Marc

    The buildup of hydrogen in the heat transfer fluid (HTF) that circulates through components of parabolic trough power plants decreases receiver thermal efficiency, and ultimately, it decreases plant performance and electricity output. The generation and occurrence of hydrogen in the HTF provides the driving force for hydrogen to permeate from the HTF through the absorber tube wall and into the receiver annulus. Getters adsorb hydrogen from the annulus volume until they saturate and are no longer able to maintain low hydrogen pressure. The increase in hydrogen pressure within the annulus significantly degrades thermal performance of the receiver and decreases overallmore » power-plant efficiency. NREL and Acciona Energy North America (Acciona) are developing a method to control the levels of dissolved hydrogen in the circulating HTF. The basic approach is to remove hydrogen from the expansion tanks of the HTF subsystem at a rate that maintains hydrogen in the circulating HTF to a target level. Full-plant steady-state models developed by the National Renewable Energy Laboratory (NREL) predict that if hydrogen is removed from the HTF within the expansion tanks, the HTF that circulates through the collector field remains essentially free of hydrogen until the HTF returns to the power block in the hot headers. One of the key findings of our modeling is the prediction that hydrogen will reverse-permeate out of the receiver annulus if dissolved hydrogen in the HTF is kept sufficiently low. To test this prediction, we performed extended heating of an in-service receiver that initially had high levels of hydrogen in its annulus. The heating was performed using NREL's receiver test stand. Results of our testing showed that receiver heat loss steadily decreased with daily heating, resulting in a corresponding improvement in receiver thermal efficiency.« less

  17. The Twist Tensor Nuclear Norm for Video Completion.

    PubMed

    Hu, Wenrui; Tao, Dacheng; Zhang, Wensheng; Xie, Yuan; Yang, Yehui

    2017-12-01

    In this paper, we propose a new low-rank tensor model based on the circulant algebra, namely, twist tensor nuclear norm (t-TNN). The twist tensor denotes a three-way tensor representation to laterally store 2-D data slices in order. On one hand, t-TNN convexly relaxes the tensor multirank of the twist tensor in the Fourier domain, which allows an efficient computation using fast Fourier transform. On the other, t-TNN is equal to the nuclear norm of block circulant matricization of the twist tensor in the original domain, which extends the traditional matrix nuclear norm in a block circulant way. We test the t-TNN model on a video completion application that aims to fill missing values and the experiment results validate its effectiveness, especially when dealing with video recorded by a nonstationary panning camera. The block circulant matricization of the twist tensor can be transformed into a circulant block representation with nuclear norm invariance. This representation, after transformation, exploits the horizontal translation relationship between the frames in a video, and endows the t-TNN model with a more powerful ability to reconstruct panning videos than the existing state-of-the-art low-rank models.

  18. Role of circulation in European heatwaves using flow analogues

    NASA Astrophysics Data System (ADS)

    Jézéquel, Aglaé; Yiou, Pascal; Radanovics, Sabine

    2018-02-01

    The intensity of European heatwaves is connected to specific synoptic atmospheric circulation. Given the relatively small number of observations, estimates of the connection between the circulation and temperature require ad hoc statistical methods. This can be achieved through the use of analogue methods, which allow to determine a distribution of temperature conditioned to the circulation. The computation of analogues depends on a few parameters. In this article, we evaluate the influence of the variable representing the circulation, the size of the domain of computation, the length of the dataset, and the number of analogues on the reconstituted temperature anomalies. We tested the sensitivity of the reconstitution of temperature to these parameters for four emblematic recent heatwaves: June 2003, August 2003, July 2006 and July 2015. The paper provides general guidelines for the use of flow analogues to investigate European summer heatwaves. We found that Z500 is better suited than SLP to simulate temperature anomalies, and that rather small domains lead to better reconstitutions. The dataset length has an important influence on the uncertainty. We conclude by a set of recommendations for an optimal use of analogues to probe European heatwaves.

  19. Do circulating tumor cells, exosomes, and circulating tumor nucleic acids have clinical utility? A report of the association for molecular pathology.

    PubMed

    Gold, Bert; Cankovic, Milena; Furtado, Larissa V; Meier, Frederick; Gocke, Christopher D

    2015-05-01

    Diagnosing and screening for tumors through noninvasive means represent an important paradigm shift in precision medicine. In contrast to tissue biopsy, detection of circulating tumor cells (CTCs) and circulating tumor nucleic acids provides a minimally invasive method for predictive and prognostic marker detection. This allows early and serial assessment of metastatic disease, including follow-up during remission, characterization of treatment effects, and clonal evolution. Isolation and characterization of CTCs and circulating tumor DNA (ctDNA) are likely to improve cancer diagnosis, treatment, and minimal residual disease monitoring. However, more trials are required to validate the clinical utility of precise molecular markers for a variety of tumor types. This review focuses on the clinical utility of CTCs and ctDNA testing in patients with solid tumors, including somatic and epigenetic alterations that can be detected. A comparison of methods used to isolate and detect CTCs and some of the intricacies of the characterization of the ctDNA are also provided. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  20. High T3, Low T4 Serum Levels in Mct8 Deficiency Are Not Caused by Increased Hepatic Conversion through Type I Deiodinase

    PubMed Central

    Wirth, Eva K.; Rijntjes, Eddy; Meyer, Franziska; Köhrle, Josef; Schweizer, Ulrich

    2015-01-01

    Background The Allan-Herndon-Dudley syndrome is a severe psychomotor retardation accompanied by specific changes in circulating thyroid hormone levels (high T3, low T4). These are caused by mutations in the thyroid hormone transmembrane transport protein monocarboxylate transporter 8 (MCT8). Objective: To test the hypothesis that circulating low T4 and high T3 levels are caused by enhanced conversion of T4 via increased activity of hepatic type I deiodinase (Dio1). Methods We crossed mice deficient in Mct8 with mice lacking Dio1 activity in hepatocytes. Translation of the selenoenzyme Dio1 was abrogated by hepatocyte-specific inactivation of selenoprotein biosynthesis. Results Inactivation of Dio1 activity in the livers of global Mct8-deficient mice does not restore normal circulating thyroid hormone levels. Conclusions Our data suggest that although hepatic Dio1 activity is increased in Mct8-deficient mice, it does not cause the observed abnormal circulating thyroid hormone levels. Since global inactivation of Dio1 in Mct8-deficient mice does normalize circulating thyroid hormone levels, the underlying mechanism and relevant tissues involved remain to be elucidated. PMID:26601078

  1. High T3, Low T4 Serum Levels in Mct8 Deficiency Are Not Caused by Increased Hepatic Conversion through Type I Deiodinase.

    PubMed

    Wirth, Eva K; Rijntjes, Eddy; Meyer, Franziska; Köhrle, Josef; Schweizer, Ulrich

    2015-09-01

    The Allan-Herndon-Dudley syndrome is a severe psychomotor retardation accompanied by specific changes in circulating thyroid hormone levels (high T3, low T4). These are caused by mutations in the thyroid hormone transmembrane transport protein monocarboxylate transporter 8 (MCT8). To test the hypothesis that circulating low T4 and high T3 levels are caused by enhanced conversion of T4 via increased activity of hepatic type I deiodinase (Dio1). We crossed mice deficient in Mct8 with mice lacking Dio1 activity in hepatocytes. Translation of the selenoenzyme Dio1 was abrogated by hepatocyte-specific inactivation of selenoprotein biosynthesis. Inactivation of Dio1 activity in the livers of global Mct8-deficient mice does not restore normal circulating thyroid hormone levels. Our data suggest that although hepatic Dio1 activity is increased in Mct8-deficient mice, it does not cause the observed abnormal circulating thyroid hormone levels. Since global inactivation of Dio1 in Mct8-deficient mice does normalize circulating thyroid hormone levels, the underlying mechanism and relevant tissues involved remain to be elucidated.

  2. Effect of circulating tissue factor on hypercoagulability in type 2 diabetes mellitus studied by rheometry and dielectric blood coagulometry.

    PubMed

    Uchimura, Isao; Kaibara, Makoto; Nagasawa, Masayuki; Hayashi, Yoshihito

    2016-01-01

    Hypercoagulability in type 2 diabetes mellitus (T2DM) patients increases their risk of cardiovascular diseases. The aim of this work was to investigate the hypercoagulation mechanism in T2DM patients in terms of circulating tissue factor (TF). Whole blood coagulation tests by damped oscillation rheometry and dielectric blood coagulometry (DBCM) were performed. The average coagulation time was significantly shorter for T2DM patients than for healthy controls. In vitro addition of either anti-TF or anti-activated factor VII (FVIIa) antibody to hypercoagulable blood samples prolonged coagulation times for one group of patients, while coagulation times remained short for another group. The levels of circulating TF were estimated in the former group by measuring the coagulation times for blood samples from healthy subjects with addition of various concentrations of TF and comparing them with the coagulation times for the group. The results indicated that the levels of circulating TF were on the order of subpicomolar at most. Circulating TF is at least partially responsible for a hypercoagulable group of T2DM patients, while an abnormality in the intrinsic coagulation pathway probably occurs in the other group.

  3. Growth hormone in sports: detecting the doped or duped.

    PubMed

    Ho, Ken K Y; Nelson, Anne E

    2011-01-01

    Doping with growth hormone (GH) is banned; however, there is anecdotal evidence that it is widely abused. GH is reportedly often used in combination with anabolic steroids at high doses for several months. Development of a robust test for detecting GH has been challenging since recombinant human 22-kDa GH used in doping is indistinguishable analytically from endogenous GH and there are wide physiological fluctuations in circulating GH concentrations. One approach to GH testing is based on measurement of different circulating GH isoforms using immunoassays that differentiate between 22-kDa and other GH isoforms. Administration of 22-kDa GH results in a change in its abundance relative to other endogenous pituitary GH isoforms. The differential isoform method is, however, limited by its short time window of detection. A second approach that extends the time window of detection is based on detection of increased levels of circulating GH-responsive proteins, such as the insulin-like growth factor (IGF) axis and collagen peptides. As age and gender are the major determinants of variability for IGF-I and the collagen markers, a test based on these markers must take these factors into account. Extensive data now validate the GH-responsive marker approach, and implementation is largely dependent on establishing an assured supply of standardized assays. Robust tests are available to detect GH and enforce the ban on its abuse in sports. Novel approaches that include gene expression and proteomic profiling must continue to be pursued to expand the repertoire of testing approaches available and to maintain deterrence of GH doping. Copyright © 2011 S. Karger AG, Basel.

  4. Immunodiagnosis of Fasciola gigantica Infection Using Monoclonal Antibody-Based Sandwich ELISA and Immunochromatographic Assay for Detection of Circulating Cathepsin L1 Protease

    PubMed Central

    Anuracpreeda, Panat; Chawengkirttikul, Runglawan; Sobhon, Prasert

    2016-01-01

    Background Tropical fasciolosis caused by Fasciola gigantica infection is one of the major diseases infecting ruminants in the tropical regions of Africa and Asia including Thailand. Parasitological diagnosis of fasciolosis is often unreliable and possesses low sensitivity. Therefore, the detection of circulating parasite antigens is thought to be a better alternative for diagnosis of fasciolosis, as it reflects the real parasite burden. Methods In this study, we have produced a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1 (rFgCatL1), and developed both sandwich enzyme-linked immunosorbent assay (sandwich ELISA) and immunochromatographic (IC) test for rapid detection of circulating cathepsin L1 protease (CatL1) in the sera from mice experimentally and cattle naturally infected with Fasciola gigantica. MoAb 4E3 and biotinylated rabbit anti-recombinant CatL1 antibody were selected due to their high reactivities and specificities. Results The lower detection limits of sandwich ELISA and IC test were 3 pg/ml and 0.256 ng/ml, respectively. Sandwich ELISA and IC test could detect F. gigantica infection from day 1 to 35 post infection. In experimental mice, the sensitivity, specificity and accuracy were 95%, 100% and 98.6% (for sandwich ELISA), and 93%, 100% and 98.2% (for IC test), while in natural cattle they were 98.3%, 100% and 99.5% (for sandwich ELISA), and 96.7%, 100% and 99.1% (for IC test). Conclusions These two assay methods showed high efficiencies and precisions for diagnosis of fasciolosis by F. gigantica. PMID:26731402

  5. Immunodiagnosis of Fasciola gigantica Infection Using Monoclonal Antibody-Based Sandwich ELISA and Immunochromatographic Assay for Detection of Circulating Cathepsin L1 Protease.

    PubMed

    Anuracpreeda, Panat; Chawengkirttikul, Runglawan; Sobhon, Prasert

    2016-01-01

    Tropical fasciolosis caused by Fasciola gigantica infection is one of the major diseases infecting ruminants in the tropical regions of Africa and Asia including Thailand. Parasitological diagnosis of fasciolosis is often unreliable and possesses low sensitivity. Therefore, the detection of circulating parasite antigens is thought to be a better alternative for diagnosis of fasciolosis, as it reflects the real parasite burden. In this study, we have produced a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1 (rFgCatL1), and developed both sandwich enzyme-linked immunosorbent assay (sandwich ELISA) and immunochromatographic (IC) test for rapid detection of circulating cathepsin L1 protease (CatL1) in the sera from mice experimentally and cattle naturally infected with Fasciola gigantica. MoAb 4E3 and biotinylated rabbit anti-recombinant CatL1 antibody were selected due to their high reactivities and specificities. The lower detection limits of sandwich ELISA and IC test were 3 pg/ml and 0.256 ng/ml, respectively. Sandwich ELISA and IC test could detect F. gigantica infection from day 1 to 35 post infection. In experimental mice, the sensitivity, specificity and accuracy were 95%, 100% and 98.6% (for sandwich ELISA), and 93%, 100% and 98.2% (for IC test), while in natural cattle they were 98.3%, 100% and 99.5% (for sandwich ELISA), and 96.7%, 100% and 99.1% (for IC test). These two assay methods showed high efficiencies and precisions for diagnosis of fasciolosis by F. gigantica.

  6. Estradiol concentrations and working memory performance in women of reproductive age.

    PubMed

    Hampson, Elizabeth; Morley, Erin E

    2013-12-01

    Estrogen has been proposed to exert a regulatory influence on the working memory system via actions in the female prefrontal cortex. Tests of this hypothesis have been limited almost exclusively to postmenopausal women and pharmacological interventions. We explored whether estradiol discernibly influences working memory within the natural range of variation in concentrations characteristic of the menstrual cycle. The performance of healthy women (n=39) not using hormonal contraceptives, and a control group of age- and education-matched men (n=31), was compared on a spatial working memory task. Cognitive testing was done blind to ovarian status. Women were retrospectively classified into low- or high-estradiol groups based on the results of radioimmunoassays of saliva collected immediately before and after the cognitive testing. Women with higher levels of circulating estradiol made significantly fewer errors on the working memory task than women tested under low estradiol. Pearson's correlations showed that the level of salivary estradiol but not progesterone was correlated inversely with the number of working memory errors produced. Women tested at high levels of circulating estradiol tended to be more accurate than men. Superior performance by the high estradiol group was seen on the working memory task but not on two control tasks, indicating selectivity of the effects. Consistent with previous studies of postmenopausal women, higher levels of circulating estradiol were associated with better working memory performance. These results add further support to the hypothesis that the working memory system is modulated by estradiol in women, and show that the effects can be observed under non-pharmacological conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Borehole model for simulation transport geothermal heat with heat pipe system and with forced circulation of heat carrier

    NASA Astrophysics Data System (ADS)

    Jakubský, Michal; Lenhard, Richard; Vantúch, Martin; Malcho, Milan

    2012-04-01

    In the call OPVaV-2008/2.2/01-SORO Operational Programme Research and Development - knowledge and technology transfer from research and development into practice (ITMS-26220220057), whose strategic goal is "Device to use low-potential geothermal heat without forced circulation of heat carrier deep in the well "in the Department of Energy laboratory techniques to construct a simulator of transport low potential of geothermal energy in comparative test-drilling in the laboratory. The article describes a device that was designed as a scale model of two deep boreholes each of which withdraws the earth's heat by heat transfer technology and heat carrier. Device using forced circulation of heat carrier will respond in the construction of equipment currently used to transport heat from deep borehole. As the heat carrier will be used CO2. Facilities without using forced circulation of heat carrier, the new technology, which will be used as heat carrier ammonia (NH3).

  8. Increased beta-adrenergic responsiveness induced by 14 days exposure to simulated microgravity

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Polet, J. L.; Engelke, K. A.; Hoffler, G. W.; Lane, L. D.; Blomqvist, C. G.

    1995-01-01

    Increased sensitivity of end-organ responses to neuroendocrine stimuli as a result of prolonged exposure to the relative inactivity of microgravity has recently been hypothesized. This notion is based on the inverse relationship between circulating norepinephrine and beta-adrenoreceptor sensitivity. The beta-adrenoreceptor activity is reduced in individuals who have elevated plasma norepinephrine as a result of regular exposure to upright posture and physical exercise. In contrast, adrenoreceptor hypersensitivity has been reported in patients with dysautonomias in which circulating catecholamines are absent or reduced. Taken together, these studies and the observation that circulating plasma norepinephrine has been reduced during spaceflight and in groundbased simulations of microgravity prompt the suggestion that adrenoreceptor hypersensitivity may be a consequence of the adaptation to spaceflight. We conducted an experiment designed to measure cardiovascular responses to adrenoreceptor agonists in human subjects before and after prolonged exposure to 6 deg head-down tilt (HDT) to test the hypothesis that adaptation to microgravity increases adrenoreceptor responsiveness, and that this adaptation is associated with reduced levels of circulating norepinephrine.

  9. Molecular detection and genetic characterization of circulating measles virus in northern Italy.

    PubMed

    Piccirilli, Giulia; Chiereghin, Angela; Pascucci, Maria Grazia; Frasca, Gabriella; Zuntini, Roberta; Ferrari, Simona; Gabrielli, Liliana; Landini, Maria Paola; Lazzarotto, Tiziana

    2016-08-01

    Laboratory diagnosis of measles virus (MV) infection and genetic characterization of circulating MV play an essential role in measles surveillance, allowing proper interventions to interrupt endemic transmission. We describe results obtained using serological and molecular methods to confirm MV infection among suspected cases reported in a large region in the north of Italy during 2010-2014 and the genotyping of the MV strains detected. Three hundred seventy-two samples (361 urine and 11 oral fluids) were tested for MV-RNA detection. In 281 cases, the serological results for MV-IgM detection were also available. A total of 276 cases were classified as confirmed measles and MV-RNA detection resulted positive for 239/276 cases. Nucleotide sequence analysis revealed sporadic cases of genotypes D9 and different circulations of endemic MV strains (D8, D4 and B3). This data suggests that there is still an unvaccinated part of the population maintaining the endemic circulation of MV in Italy. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Idealised modelling of ocean circulation driven by conductive and hydrothermal fluxes at the seabed

    NASA Astrophysics Data System (ADS)

    Barnes, Jowan M.; Morales Maqueda, Miguel A.; Polton, Jeff A.; Megann, Alex P.

    2018-02-01

    Geothermal heating is increasingly recognised as an important factor affecting ocean circulation, with modelling studies suggesting that this heat source could lead to first-order changes in the formation rate of Antarctic Bottom Water, as well as a significant warming effect in the abyssal ocean. Where it has been represented in numerical models, however, the geothermal heat flux into the ocean is generally treated as an entirely conductive flux, despite an estimated one third of the global geothermal flux being introduced to the ocean via hydrothermal sources. A modelling study is presented which investigates the sensitivity of the geothermally forced circulation to the way heat is supplied to the abyssal ocean. An analytical two-dimensional model of the circulation is described, which demonstrates the effects of a volume flux through the ocean bed. A simulation using the NEMO numerical general circulation model in an idealised domain is then used to partition a heat flux between conductive and hydrothermal sources and explicitly test the sensitivity of the circulation to the formulation of the abyssal heat flux. Our simulations suggest that representing the hydrothermal flux as a mass exchange indeed changes the heat distribution in the abyssal ocean, increasing the advective heat transport from the abyss by up to 35% compared to conductive heat sources. Consequently, we suggest that the inclusion of hydrothermal fluxes can be an important addition to course-resolution ocean models.

  11. Contribution made by parabiosis to the understanding of energy balance regulation

    PubMed Central

    Harris, Ruth

    2013-01-01

    Parabiosis is a chronic preparation that allows exchange of whole blood between two animals. It has been used extensively to test for involvement of circulating factors in feedback regulation of physiological systems. The total blood volume of each animal exchanges approximately ten times each day, therefore, factors that are rapidly cleared from the circulation do not reach equilibrium across the parabiotic union whereas those with a long half-life achieve a uniform concentration and bioactivity in both members of a pair. Involvement of a circulating factor in the regulation of energy balance was first demonstrated when one member of a pair of parabiosed rats became hyperphagic and obese following bilateral lesioning of the ventromedial hypothalamus. The non-lesioned partner stopped eating, lost a large amount of weight and appeared to be responding to a circulating “satiety” factor released by the obese rat. These results were confirmed using different techniques to induce obesity in one member of a pair. Studies with phenotypically similar ob/ob obese and db/db diabetic mice indicated that the obese mouse lacked a circulating signal that regulated energy balance, whereas the diabetic mouse appeared insensitive to such a signal. Positional cloning studies identified leptin as the circulating factor and subsequent parabiosis studies confirmed leptin’s ability to exchange effectively between parabionts. These studies also suggest the presence of additional unidentified factors that influence body composition. PMID:23470554

  12. A Targeted Q-PCR-Based Method for Point Mutation Testing by Analyzing Circulating DNA for Cancer Management Care.

    PubMed

    Thierry, Alain R

    2016-01-01

    Circulating cell-free DNA (cfDNA) is a valuable source of tumor material available with a simple blood sampling enabling a noninvasive quantitative and qualitative analysis of the tumor genome. cfDNA is released by tumor cells and exhibits the genetic and epigenetic alterations of the tumor of origin. Circulating cell-free DNA (cfDNA) analysis constitutes a hopeful approach to provide a noninvasive tumor molecular test for cancer patients. Based upon basic research on the origin and structure of cfDNA, new information on circulating cell-free DNA (cfDNA) structure, and specific determination of cfDNA fragmentation and size, we revisited Q-PCR-based method and recently developed a the allele-specific-Q-PCR-based method with blocker (termed as Intplex) which is the first multiplexed test for cfDNA. This technique, named Intplex(®) and based on a refined Q-PCR method, derived from critical observations made on the specific structure and size of cfDNA. It enables the simultaneous determination of five parameters: the cfDNA total concentration, the presence of a previously known point mutation, the mutant (tumor) cfDNA concentration (ctDNA), the proportion of mutant cfDNA, and the cfDNA fragmentation index. Intplex(®) has enabled the first clinical validation of ctDNA analysis in oncology by detecting KRAS and BRAF point mutations in mCRC patients and has demonstrated that a blood test could replace tumor section analysis for the detection of KRAS and BRAF mutations. The Intplex(®) test can be adapted to all mutations, genes, or cancers and enables rapid, highly sensitive, cost-effective, and repetitive analysis. As regards to the determination of mutations on cfDNA Intplex(®) is limited to the mutational status of known hotspot mutation; it is a "targeted approach." However, it offers the opportunity in detecting quantitatively and dynamically mutation and could constitute a noninvasive attractive tool potentially allowing diagnosis, prognosis, theranostics, therapeutic monitoring, and follow-up of cancer patients expanding the scope of personalized cancer medicine.

  13. Analysis of rabies diagnosis in dogs and cats in the state of São Paulo, Brazil.

    PubMed

    Castilho, Juliana Galera; Achkar, Samira Maria; de Novaes Oliveira, Rafael; Mori, Enio; Carnieli, Pedro; Macedo, Carla Isabel

    2018-05-08

    The genetic lineage of rabies virus (RABV) associated with dogs has not been found in the state of São Paulo since 1998, and all cases of rabies in domestic animals reported since then have involved the RABV lineage that circulates in bats. As there has been a change in the rabies transmission cycle in cats and dogs, we decided to analyze the tests used to diagnose rabies in these animals in the 15-year period from 2002 to 2016 in the state of São Paulo. During this period, 85,508 central nervous system (CNS) samples from dogs and cats were submitted to the Rabies Diagnosis Section at the Pasteur Institute of São Paulo for testing. All of the samples were tested by the fluorescent antibody test (FAT) and at least one of the following three tests: mouse inoculation test (MIT), rabies tissue culture infection test (RTCIT) and reverse transcription polymerase chain reaction (RT-PCR). Of all the samples tested, twenty were positive in at least one of these assays. Four other positive samples were identified at other institutions in the state of São Paulo. Of the twenty samples that tested positive at the Pasteur Institute of São Paulo, nine were tested by FAT, and the results were subsequently confirmed by other techniques; five gave inconclusive results, and therefore, other techniques had to be used as soon as possible in case the samples were positive; and six were negative by FAT and positive by one or more of the following tests: RTCIT, MIT and RT-PCR. Genetic typing of isolates from eighteen samples identified them as the lineage circulating in bats. In light of this finding, which indicates that genetic lineages associated with bats are circulating in domestic animals in the state of São Paulo, when the results of FAT carried out with samples from aggressive cats and dogs are inconclusive, complementary tests should be used. Decomposing samples and samples for which FAT was inconclusive should be tested using molecular techniques so that a definitive result can be obtained quickly and timely post-exposure prophylaxis can be administered to exposed individuals.

  14. Electrostimulation of muscles as a method for the treatment and prophylaxis of hemodynamic disturbances during prolonged hypokinesia

    NASA Technical Reports Server (NTRS)

    Dukhin, Y. O.; Zhukovskyy, L. Y.

    1980-01-01

    Hemodynamic and periopheral circulation indexes were recorded before, at the end of, and 5 days after 10 days of electrostimulation for 45 min daily, at rest and after a physical loading test. It was found that stroke and minute volume, cardiac output, and regional circulation improved and heart rate and peripheral resistance decreased. The functional state of the cardiac muscle and vascular tone are improved by electrostimulation of selected groups of skeletal muscles.

  15. [The physiology of the isolated dog pancreas--the influence of the actual blood glucose level on the blood circulation in the pancreas].

    PubMed

    Hempfling, H; Husemann, B

    1975-06-01

    1. Glucose loading tests were undertaken on isolated pancreas or pancreas-duodenal preparations. 2. In 75% of cases a vasodilatation can be observed which leads to enhanced blood circulation under constant pressure in the isolated organ. 3. This vasodilatation persists until the level of blood sugar has normalized. 4. The experiment being carried out on an isolated organ, external factors such as the vagus nerve, do not become active.

  16. Non-Invasive Assessment of Liver Function

    PubMed Central

    Helmke, Steve; Colmenero, Jordi; Everson, Gregory T.

    2015-01-01

    Purpose of review It is our opinion that there is an unmet need in Hepatology for a minimally- or noninvasive test of liver function and physiology. Quantitative liver function tests (QLFTs) define the severity and prognosis of liver disease by measuring the clearance of substrates whose uptake or metabolism is dependent upon liver perfusion or hepatocyte function. Substrates with high affinity hepatic transporters exhibit high “first-pass” hepatic extraction and their clearance measures hepatic perfusion. In contrast, substrates metabolized by the liver have low first-pass extraction and their clearance measures specific drug metabolizing pathways. Recent Findings We highlight one QLFT, the dual cholate test, and introduce the concept of a disease severity index (DSI) linked to clinical outcome that quantifies the simultaneous processes of hepatocyte uptake, clearance from the systemic circulation, clearance from the portal circulation, and portal-systemic shunting. Summary It is our opinion that dual cholate is a relevant test for defining disease severity, monitoring the natural course of disease progression, and quantifying the response to therapy. PMID:25714706

  17. Non-invasive prenatal testing using cell-free fetal DNA in maternal circulation.

    PubMed

    Liao, Gary J W; Gronowski, Ann M; Zhao, Zhen

    2014-01-20

    The identification of cell-free fetal DNA (cffDNA) in maternal circulation has made non-invasive prenatal testing (NIPT) possible. Maternal plasma cell free DNA is a mixture of maternal and fetal DNA, of which, fetal DNA represents a minor population in maternal plasma. Therefore, methods with high sensitivity and precision are required to detect and differentiate fetal DNA from the large background of maternal DNA. In recent years, technical advances in the molecular analysis of fetal DNA (e.g., digital PCR and massively parallel sequencing (MPS)) has enabled the successful implementation of noninvasive testing into clinical practice, such as fetal sex assessment, RhD genotyping, and fetal chromosomal aneuploidy detection.With the ability to decipher the entire fetal genome from maternal plasma DNA, we foresee that an increased number of non-invasive prenatal tests will be available for detecting many single-gene disorders in the near future. This review briefly summarizes the technical aspects of the NIPT and application of NIPT in clinical practice.

  18. Basophil degranulation induced by oral poison ivy antigen.

    PubMed

    Shelley, W B; Resnik, S S

    1965-08-01

    Seven subjects shown by patch test to be sensitive to poison ivy oleoresin were challenged with graded oral doses of ivy extract. In each instance the circulating basophil leukocytes showed significant degranulation within one hour of challenge. This finding was interpreted as evidence of the presence of immediate-type circulating antibody to ivy antigen in these subjects. No drop in the absolute basophil count was noted, but with higher oral doses the degranulation persisted for several days. Thirteen control subjects showed no change in the basophil morphology or count, indicating that the resin at these levels was not toxic to this cell. All but one of the sensitive subjects showed objective patch test evidence of hyposensitization following the intensive three-week course of oral poison ivy antigen.

  19. Effects of pore pressure and mud filtration on drilling rates in a permeable sandstone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Black, A.D.; DiBona, B.; Sandstrom, J.

    1983-10-01

    During laboratory drilling tests in a permeable sandstone, the effects of pore pressure and mud filtration on penetration rates were measured. Four water-base muds were used to drill four saturated sandstone samples. The drilling tests were conducted at constant borehole pressure with different back pressures maintained on the filtrate flowing from the bottom of the sandstone samples. Bit weight was also varied. Filtration rates were measured while drilling and with the bit off bottom and mud circulating. Penetration rates were found to be related to the difference between the filtration rates measured while drilling and circulating. There was no observedmore » correlation between standard API filtration measurements and penetration rate.« less

  20. Effects of pore pressure and mud filtration on drilling rates in a permeable sandstone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Black, A.D.; Dearing, H.L.; DiBona, B.G.

    1985-09-01

    During laboratory drilling tests in a permeable sandstone, the effects of pore pressure and mud filtration on penetration rates were measured. Four water-based muds were used to drill four saturated sandstone samples. The drilling tests were conducted at constant borehole pressure while different backpressures were maintained on the filtrate flowing from the bottom of the sandstone samples. Bit weight was varied also. Filtration rates were measured while circulating mud during drilling and with the bit off bottom. Penetration rates were found to be related qualitatively to the difference between the filtration rates measured while drilling and circulating. There was nomore » observed correlation between standard API filtration measurements and penetration rate.« less

  1. Hybridoma cell agglutination as a novel test to detect circulating antigen of Schistosoma japonicum.

    PubMed

    Li, Yong-Long; Liu, Wenqi; Ruppel, Andreas

    2003-01-01

    We developed a serodiagnostic test which is based on the agglutination of hybridoma cells. In the presence of specific antigen, agglutination of the fixed and stained cells occurs and can be visualized in analogy to traditional erythrocyte agglutination. The procedures were developed with a murine cell line producing a monoclonal antibody against a schistosome gut protein and sera of patients and mice infected with Schistosoma japonicum. This test is capable of detecting circulating antigen during pre-patency in mice infected with 50 cercariae. Its sensitivity was high with acute schistosomiasis japonica (97%, n = 32) and moderate with chronic cases (75%, n = 57). No positive reactions were obtained with healthy persons (n = 78) or patients infected with other parasites (Chlonorchis sinensis, n = 20; Paragonimus westermani, n = 20; Plasmodium vivax, n = 10) or suffering from lupus erythomatodus (n = 5) or mononucleosis (n = 10).

  2. Pretest analysis of natural circulation on the PWR model PACTEL with horizontal steam generators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kervinen, T.; Riikonen, V.; Ritonummi, T.

    A new tests facility - parallel channel tests loop (PACTEL)- has been designed and built to simulate the major components and system behavior of pressurized water reactors (PWRs) during postulated small- and medium-break loss-of-coolant accidents. Pretest calculations have been performed for the first test series, and the results of these calculations are being used for planning experiments, for adjusting the data acquisition system, and for choosing the optimal position and type of instrumentation. PACTEL is a volumetrically scaled (1:305) model of the VVER-440 PWR. In all the calculated cases, the natural circulation was found to be effective in removing themore » heat from the core to the steam generator. The loop mass flow rate peaked at 60% mass inventory. The straightening of the loop seals increased the mass flow rate significantly.« less

  3. Molecular Characteristics of Influenza Virus Type B Lineages Circulating in Poland.

    PubMed

    Bednarska, K; Hallmann-Szelińska, E; Kondratiuk, K; Rabczenko, D; Brydak, L B

    2016-01-01

    From the time of the Hong Kong pandemic of 1968-1969, vaccines against influenza are trivalent, containing two subtypes of influenza type A: A/H1N1/ and A/H3N2/, and influenza type B. In 1980, circulation of the new Yamagata and Victoria lineages of influenza B virus was noted. Since both lineages have continued to circulate, the second lineage of influenza B was included into the trivalent vaccine as of the 2013/2014 epidemic season. In Poland, co-circulation of influenza type A and B has been registered over many seasons, although type A has predominated. According to the ACIP recommendations, quadrivalent vaccines against influenza are administered in some continents due to circulation of the B-Yamagata and B-Victoria lineages. Currently, only trivalent vaccines against influenza are available in Poland. The aim of the present research was to determine which of the two influenza type B lineages, or possibly both, would be isolated in Poland. The study was conducted with the use of RT-PCR. Generally, in the 2014/2015 epidemic season in Poland, circulation of type B virus was confirmed in 34 % of influenza cases. A total of 89 specimens of influenza B were tested, including co-infections of influenza B with influenza A subtypes: A/H1N1/pdm09 and A/H3N2/. The findings were that only lineage B-Yamagata circulates in the Polish population. Therefore, vaccines available on the Polish market do not require the introduction of a fourth component.

  4. e-NIHSS: an Expanded National Institutes of Health Stroke Scale Weighted for Anterior and Posterior Circulation Strokes.

    PubMed

    Olivato, Silvia; Nizzoli, Silvia; Cavazzuti, Milena; Casoni, Federica; Nichelli, Paolo Frigio; Zini, Andrea

    2016-12-01

    The National Institutes of Health Stroke Scale (NIHSS) is the most widespread clinical scale used in patients presenting with acute stroke. The merits of the NIHSS include simplicity, quickness, and agreement between clinicians. The clinical evaluation on posterior circulation stroke remains still a limit of NIHSS. We assessed the application of a new version of NIHSS, the e-NIHSS (expanded NIHSS), adding specific elements in existing items to explore signs/symptoms of a posterior circulation stroke. A total of 22 consecutive patients with suspected vertebrobasilar stroke were compared with 25 patients with anterior circulation stroke using NIHSS and e-NIHSS. We compared the NIHSS and e-NIHSS scores obtained by the 2 examiners, in patients with posterior circulation infarct (POCI), using the Wilcoxon test. Patients with POCI evaluated with e-NIHSS had an average of 2 points higher than patients evaluated with classical NIHSS. The difference was statistically significant (P < .05), weighted by the new expanded items. The NIHSS is a practical scale model, with high reproducibility between trained, different examiners, focused on posterior circulation strokes, with the same total score and number of items of the existing NIHSS. The e-NHISS could improve the sensitivity of NIHSS in posterior circulation stroke and could have an impact on clinical trials, as well as on outcomes. Further studies are needed to investigate a larger number of patients and the correlation between the e-NIHSS score and neuroimaging findings. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  5. Long Duration Testing of a Spacesuit Water Membrane Evaporator Prototype

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Makinen, Janice; Cox, Marlon; Watts, Carly; Campbell, Colin; Vogel, Matthew; Colunga, Aaron

    2011-01-01

    The Spacesuit Water Membrane Evaporator (SWME) is a heat-rejection device that is being developed to perform thermal control for advanced spacesuits. Cooling is achieved by circulating water from the liquid cooling garment (LCG) through hollow fibers (HoFi?s), which are small hydrophobic tubes. Liquid water remains within the hydrophobic tubes, but water vapor is exhausted to space, thereby removing heat. A SWME test article was tested over the course of a year, for a total of 1200 cumulative hours. In order to evaluate SWME tolerance to contamination due to constituents caused by distillation processes, these constituents were allowed to accumulate in the water as evaporation occurred. A test article was tested over the course of a year for a total of 1200 cumulative hours. The heat rejection performance of the SWME degraded significantly--below 700 W, attributable to the accumulation of rust in the circulating loop and biofilm growth. Bubble elimination capability, a feature that was previously proven with SWME, was compromised during the test, most likely due to loss of hydrophobic properties of the hollow fibers. The utilization of water for heat rejection was shown not to be dependent on test article, life cycle, heat rejection rate, or freezing of the membranes.

  6. Long Duration Testing of a Spacesuit Water Membrane Evaporator Prototype

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Makinen, Janice; Cox, Marlon; Watts, Carly; Campbell, Colin; Vogel, Matthew; Colunga, Aaron; Conger, Bruce

    2012-01-01

    The Spacesuit Water Membrane Evaporator (SWME) is a heat-rejection device that is being developed to perform thermal control for advanced spacesuits. Cooling is achieved by circulating water from the liquid cooling garment (LCG) through hollow fibers (HoFi s), which are small hydrophobic tubes. Liquid water remains within the hydrophobic tubes, but water vapor is exhausted to space, thereby removing heat. A SWME test article was tested over the course of a year, for a total of 600 cumulative hours. In order to evaluate SWME tolerance to contamination due to constituents caused by distillation processes, these constituents were allowed to accumulate in the water as evaporation occurred. A test article was tested over the course of a year for a total of 600 cumulative hours. The heat rejection performance of the SWME degraded significantly--below 700 W, attributable to the accumulation of rust in the circulating loop and biofilm growth. Bubble elimination capability, a feature that was previously proven with SWME, was compromised during the test, most likely due to loss of hydrophobic properties of the hollow fibers. The utilization of water for heat rejection was shown not to be dependent on test article, life cycle, heat rejection rate, or freezing of the membranes.

  7. Detection of dengue virus serotypes 1, 2 and 3 in selected regions of Kenya: 2011-2014.

    PubMed

    Konongoi, Limbaso; Ofula, Victor; Nyunja, Albert; Owaka, Samuel; Koka, Hellen; Makio, Albina; Koskei, Edith; Eyase, Fredrick; Langat, Daniel; Schoepp, Randal J; Rossi, Cynthia Ann; Njeru, Ian; Coldren, Rodney; Sang, Rosemary

    2016-11-04

    Dengue fever, a mosquito-borne disease, is associated with illness of varying severity in countries in the tropics and sub tropics. Dengue cases continue to be detected more frequently and its geographic range continues to expand. We report the largest documented laboratory confirmed circulation of dengue virus in parts of Kenya since 1982. From September 2011 to December 2014, 868 samples from febrile patients were received from hospitals in Nairobi, northern and coastal Kenya. The immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) was used to test for the presence of IgM antibodies against dengue, yellow fever, West Nile and Zika. Reverse transcription polymerase chain reaction (RT-PCR) utilizing flavivirus family, yellow fever, West Nile, consensus and sero type dengue primers were used to detect acute arbovirus infections and determine the infecting serotypes. Representative samples of PCR positive samples for each of the three dengue serotypes detected were sequenced to confirm circulation of the various dengue serotypes. Forty percent (345/868) of the samples tested positive for dengue by either IgM ELISA (14.6 %) or by RT-PCR (25.1 %). Three dengue serotypes 1-3 (DENV1-3) were detected by serotype specific RT-PCR and sequencing with their numbers varying from year to year and by region. The overall predominant serotype detected from 2011-2014 was DENV1 accounting for 44 % (96/218) of all the serotypes detected, followed by DENV2 accounting for 38.5 % (84/218) and then DENV3 which accounted for 17.4 % (38/218). Yellow fever, West Nile and Zika was not detected in any of the samples tested. From 2011-2014 serotypes 1, 2 and 3 were detected in the Northern and Coastal parts of Kenya. This confirmed the occurrence of cases and active circulation of dengue in parts of Kenya. These results have documented three circulating serotypes and highlight the need for the establishment of active dengue surveillance to continuously detect cases, circulating serotypes, and determine dengue fever disease burden in the country and region.

  8. Properties of Controlled Low Strength Material with Circulating Fluidized Bed Combustion Ash and Recycled Aggregates

    PubMed Central

    Weng, Tsai-Lung; Cheng, An; Chao, Sao-Jeng; Hsu, Hui-Mi

    2018-01-01

    This study aims to investigate the effect of adding circulating fluidized bed combustion (CFBC) ash, desulfurization slag, air-cooled blast-furnace slag and coal bottom ash to the controlled low-strength material (CLSM). Test methods include slump flow test, ball drop test, water soluble chloride ion content measurement, compressive strength and length change measurement. The results show that (1) the use of CFBC hydration ash with desulfurization slag of slump flow is the best, and the use of CFBC hydration ash with coal bottom ash and slump flow is the worst; (2) CFBC hydration ash with desulfurization slag and chloride ion content is the highest; (3) 24 h ball drop test (diameter ≤ 76 mm), and test results are 70 mm to 76 mm; (4) CFBC hydration ash with desulfurization slag and compression strength is the highest, with the coal bottom ash being the lowest; increase of CFBC hydration ash can reduce compressive strength; and (5) the water-quenched blast furnace slag and CFBC hydration ash would expand, which results in length changes of CLSM specimens. PMID:29724055

  9. Investigation of natural circulation instability and transients in passively safe novel modular reactor

    NASA Astrophysics Data System (ADS)

    Shi, Shanbin

    The Purdue Novel Modular Reactor (NMR) is a new type small modular reactor (SMR) that belongs to the design of boiling water reactor (BWR). Specifically, the NMR is one third the height and area of a conventional BWR reactor pressure vessel (RPV) with an electric output of 50 MWe. The fuel cycle length of the NMR-50 is extended up to 10 years due to optimized neutronics design. The NMR-50 is designed with double passive engineering safety system. However, natural circulation BWRs (NCBWR) could experience certain operational difficulties due to flow instabilities that occur at low pressure and low power conditions. Static instabilities (i.e. flow excursion (Ledinegg) instability and flow pattern transition instability) and dynamic instabilities (i.e. density wave instability and flashing/condensation instability) pose a significant challenge in two-phase natural circulation systems. In order to experimentally study the natural circulation flow instability, a proper scaling methodology is needed to build a reduced-size test facility. The scaling analysis of the NMR uses a three-level scaling method, which was developed and applied for the design of the Purdue Multi-dimensional Integral Test Assembly (PUMA). Scaling criteria is derived from dimensionless field equations and constitutive equations. The scaling process is validated by the RELAP5 analysis for both steady state and startup transients. A new well-scaled natural circulation test facility is designed and constructed based on the scaling analysis of the NMR-50. The experimental facility is installed with different equipment to measure various thermal-hydraulic parameters such as pressure, temperature, mass flow rate and void fraction. Characterization tests are performed before the startup transient tests and quasi-steady tests to determine the loop flow resistance. The controlling system and data acquisition system are programmed with LabVIEW to realize the real-time control and data storage. The thermal-hydraulic and nuclear coupled startup transients are performed to investigate the flow instabilities at low pressure and low power conditions. Two different power ramps are chosen to study the effect of power density on the flow instability. The experimental startup transient tests show the existence of three different flow instability mechanisms during the low pressure startup transients, i.e., flashing instability, condensation induced instability, and density wave oscillations. Flashing instability in the chimney section of the test loop and density wave oscillation are the main flow instabilities observed when the system pressure is below 0.5 MPa. They show completely different type of oscillations, i.e., intermittent oscillation and sinusoidal oscillation, in void fraction profile during the startup transients. In order to perform nuclear-coupled startup transients with void reactivity feedback, the Point Kinetics model is utilized to calculate the transient power during the startup transients. In addition, the differences between the electric resistance heaters and typical fuel element are taken into account. The reactor power calculated shows some oscillations due to flashing instability during the transients. However, the void reactivity feedback does not have significant influence on the flow instability during the startup procedure for the NMR-50. Further investigation of very small power ramp on the startup transients is carried out for the thermal-hydraulic startup transients. It is found that very small power density can eliminate the flashing oscillation in the single phase natural circulation and stabilize the flow oscillations in the phase of net vapor generation. Furthermore, initially pressurized startup procedure is investigated to eliminate the main flow instabilities. The results show that the pressurized startup procedure can suppress the flashing instability at low pressure and low power conditions. In order to have a deep understanding of natural circulation flow instability, the quasi-steady tests are performed using the test facility installed with preheater and subcooler. The effects of system pressure, core inlet subcooling, core power density, inlet flow resistance coefficient, and void reactivity feedback are investigated in the quasi-steady state tests. The stability boundaries are determined between unstable and stable flow conditions in the dimensionless stability plane of inlet subcooling number and Zuber number. In order to predict the stability boundary theoretically, linear stability analysis in the frequency domain is performed at four sections of the loop. The flashing in the chimney is considered as an axially uniform heat source. The dimensionless characteristic equation of the pressure drop perturbation is obtained by considering the void fraction effect and outlet flow resistance in the chimney section. The flashing boundary shows some discrepancies with previous experimental data from the quasi-steady state tests. In the future, thermal non-equilibrium is recommended to improve the accuracy of flashing instability boundary.

  10. Core cooling under accident conditions at the high flux beam reactor (HFBR)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tichler, P.; Cheng, L.; Fauske, H.

    In certain accident scenarios, e.g. loss of coolant accidents (LOCA) all forced flow cooling is lost. Decay heating causes a temperature increase in the core coolant and the resulting thermal buoyancy causes a reversal of the flow direction to a natural circulation mode. Although there was experimental evidence during the reactor design period (1958--1963) that the heat removal capacity in the fully developed natural circulation cooling mode was relatively high, it was not possible to make a confident prediction of the heat removal capacity during the transition from downflow to natural circulation. In a LOCA scenario where even limited fuelmore » damage occurs and natural circulation is established, fission product gases could be carried from the damaged fuel by steam into areas where operator access is required to maintain the core in a coolable configuration. This would force evacuation of the building and lead to extensive core damage. As a result the HFBR was shut down by the Department of Energy (DOE) and an extensive review of the HFBR was initiated. In an effort to address this issue BNL developed a model designed to predict the heat removal limit during flow reversal that was found to be in good agreement with the test results. Currently a thermal-hydraulic test program is being developed to provide a more realistic and defensible estimate of the flow reversal heat removal limit so that the reactor power level can be increased.« less

  11. Flow rate and temperature characteristics in steady state condition on FASSIP-01 loop during commissioning

    NASA Astrophysics Data System (ADS)

    Juarsa, M.; Giarno; Rohman, A. N.; Heru K., G. B.; Witoko, J. P.; Sony Tjahyani, D. T.

    2018-02-01

    The need for large-scale experimental facilities to investigate the phenomenon of natural circulation flow rate becomes a necessity in the development of nuclear reactor safety management. The FASSIP-01 loop has been built to determine the natural circulation flow rate performance in the large-scale media and aimed to reduce errors in the results for its application in the design of new generation reactors. The commissioning needs to be done to define the capability of the FASSIP-01 loop and to prescribe the experiment limitations. On this commissioning, two scenarios experimental method has been used. The first scenario is a static condition test which was conducted to verify measurement system response during 24 hours without electrical load in heater and cooler, there is water and no water inside the rectangular loop. Second scenario is a dynamics condition that aims to understand the flow rate, a dynamic test was conducted using heater power of 5627 watts and coolant flow rate in the HSS loop of 9.35 LPM. The result of this test shows that the temperature characterization on static test provide a recommendation, that the experiments should be done at night because has a better environmental temperature stability compared to afternoon, with stable temperature around 1°C - 3°C. While on the dynamic test, the water temperature difference between the inlet-outlets in the heater area is quite large, about 7 times the temperature difference in the cooler area. The magnitude of the natural circulation flow rate calculated is much larger at about 300 times compared to the measured flow rate with different flow rate profiles.

  12. Serological diagnosis of Taenia solium in pigs: No measurable circulating antigens and antibody response following exposure to Taenia saginata oncospheres.

    PubMed

    Dorny, P; Dermauw, V; Van Hul, A; Trevisan, C; Gabriël, S

    2017-10-15

    Taenia solium taeniasis/cysticercosis is a zoonosis included in the WHO's list of neglected tropical diseases. Accurate diagnostic tools for humans and pigs are needed to monitor intervention outcomes. Currently used diagnostic tools for porcine cysticercosis all have drawbacks. Serological tests are mainly confronted with problems of specificity. More specifically, circulating antigen detecting tests cross-react with Taenia hydatigena and the possibility of transient antigens as a result of aborted infections is suspected. Furthermore, the hypothesis has been raised that hatched ingested eggs of other Taenia species may lead to a transient antibody response or to the presence of circulating antigen detectable by serological tests used for porcine cysticercosis. Here we describe the results of a study that consisted of oral administration of Taenia saginata eggs to five piglets followed by serological testing during five weeks and necropsy aiming at studying possible cross reactions in serological tests used for porcine cysticercosis. The infectivity of the eggs was verified by in vitro hatching and by experimental infection of a calf. One piglet developed acute respiratory disease and died on day 6 post infection. The remaining four piglets did not show any clinical signs until euthanasia. None of the serum samples from four piglets collected between days 0 and 35 post infection gave a positive reaction in the B158/B60 Ag-ELISA and in a commercial Western blot for antibody detection. In conclusion, this study showed that experimental exposure of four pigs to T. saginata eggs did not result in positive serologies for T. solium. These results may help interpreting serological results in monitoring of T. solium control programmes. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Pre-test analysis of protected loss of primary pump transients in CIRCE-HERO facility

    NASA Astrophysics Data System (ADS)

    Narcisi, V.; Giannetti, F.; Del Nevo, A.; Tarantino, M.; Caruso, G.

    2017-11-01

    In the frame of LEADER project (Lead-cooled European Advanced Demonstration Reactor), a new configuration of the steam generator for ALFRED (Advanced Lead Fast Reactor European Demonstrator) was proposed. The new concept is a super-heated steam generator, double wall bayonet tube type with leakage monitoring [1]. In order to support the new steam generator concept, in the framework of Horizon 2020 SESAME project (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors), the ENEA CIRCE pool facility will be refurbished to host the HERO (Heavy liquid mEtal pRessurized water cOoled tubes) test section to investigate a bundle of seven full scale bayonet tubes in ALFRED-like thermal hydraulics conditions. The aim of this work is to verify thermo-fluid dynamic performance of HERO during the transition from nominal to natural circulation condition. The simulations have been performed with RELAP5-3D© by using the validated geometrical model of the previous CIRCE-ICE test section [2], in which the preceding heat exchanger has been replaced by the new bayonet bundle model. Several calculations have been carried out to identify thermal hydraulics performance in different steady state conditions. The previous calculations represent the starting points of transient tests aimed at investigating the operation in natural circulation. The transient tests consist of the protected loss of primary pump, obtained by reducing feed-water mass flow to simulate the activation of DHR (Decay Heat Removal) system, and of the loss of DHR function in hot conditions, where feed-water mass flow rate is absent. According to simulations, in nominal conditions, HERO bayonet bundle offers excellent thermal hydraulic behavior and, moreover, it allows the operation in natural circulation.

  14. Dependence of the 0.7 anomaly on the curvature of the potential barrier in quantum wires

    NASA Astrophysics Data System (ADS)

    Smith, L. W.; Al-Taie, H.; Lesage, A. A. J.; Sfigakis, F.; See, P.; Griffiths, J. P.; Beere, H. E.; Jones, G. A. C.; Ritchie, D. A.; Hamilton, A. R.; Kelly, M. J.; Smith, C. G.

    2015-06-01

    Ninety-eight one-dimensional channels defined using split gates fabricated on a GaAs/AlGaAs heterostructure are measured during one cooldown at 1.4 K. The devices are arranged in an array on a single chip and are individually addressed using a multiplexing technique. The anomalous conductance feature known as the "0.7 structure" is studied using statistical techniques. The ensemble of data shows that the 0.7 anomaly becomes more pronounced and occurs at lower values as the curvature of the potential barrier in the transport direction decreases. This corresponds to an increase in the effective length of the device. The 0.7 anomaly is not strongly influenced by other properties of the conductance related to density. The curvature of the potential barrier appears to be the primary factor governing the shape of the 0.7 structure at a given T and B .

  15. Cure Schedule for Stycast 2651/Catalyst 11.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kropka, Jamie Michael; McCoy, John D.

    2017-11-01

    The Henkel technical data sheet (TDS) for Stycast 2651/Catalyst 11 lists three alternate cure schedules for the material, each of which would result in a different state of reaction and different material properties. Here, a cure schedule that attains full reaction of the material is defined. The use of this cure schedule will eliminate variance in material properties due to changes in the cure state of the material, and the cure schedule will serve as the method to make material prior to characterizing properties. The following recommendation was motivated by (1) a desire to cure at a single temperature formore » ease of manufacture and (2) a desire to keep the cure temperature low (to minimize residual stress build-up associated with the cooldown from the cure temperature to room temperature) without excessively limiting the cure reaction due to vitrification (i.e., material glass transition temperature, T g, exceeding cure temperature).« less

  16. Cross-stacked carbon nanotubes assisted self-separation of free-standing GaN substrates by hydride vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Wei, Tongbo; Yang, Jiankun; Wei, Yang; Huo, Ziqiang; Ji, Xiaoli; Zhang, Yun; Wang, Junxi; Li, Jinmin; Fan, Shoushan

    2016-06-01

    We report a novel method to fabricate high quality 2-inch freestanding GaN substrate grown on cross-stacked carbon nanotubes (CSCNTs) coated sapphire by hydride vapor phase epitaxy (HVPE). As nanoscale masks, these CSCNTs can help weaken the interface connection and release the compressive stress by forming voids during fast coalescence and also block the propagation of threading dislocations (TDs). During the cool-down process, thermal stress-induced cracks are initiated at the CSCNTs interface with the help of air voids and propagated all over the films which leads to full self-separation of FS-GaN substrate. Raman and photoluminescence spectra further reveal the stress relief and crystalline improvement of GaN with CSCNTs. It is expected that the efficient, low cost and mass-producible technique may enable new applications for CNTs in nitride optoelectronic fields.

  17. Nematic phase in the CE-regime of colossal magnetoresistive manganites

    NASA Astrophysics Data System (ADS)

    Ochoa, Emily; Sen, Cengiz; Dagotto, Elbio; Lamar/UTK Collaboration

    We report nematic phase tendencies around the first order CE transition in the two-orbital double exchange model with Jahn-Teller phonons at electronic density n = 0 . 5 . Starting with a random state at high temperatures, we employ a careful cool-down method using a Monte Carlo algorithm. We then monitor the spin structure factor S (q) of the CE phase as a function of temperature. Near the critical temperature, S (q) grows with decreasing temperature for both right- and left-ordered CE ladders, followed by a spontaneous symmetry breaking into one or the other as the critical temperature is achieved. Below the critical temperature a pure CE state with a staggered charge order is obtained. Our results are similar to those observed in pnictides in earlier studies. Lamar University Office of Undergraduate Research, and U.S. Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division.

  18. Far-infrared and 3D imaging for doneness assessment in chicken breast

    NASA Astrophysics Data System (ADS)

    Tao, Yang; Ibarra, Juan G.

    2001-03-01

    Sensor fusion of infrared imaging and range imaging was proposed to estimate internal temperature on just cooked chicken breasts. An infrared camera operating at 8-12 microns registered surface temperature of cooked meat samples, while a single line structured light system located the thickest region of the meat target. In this region of interest, a combined time series/neural network method is applied to correlate the internal and external temperatures during the cool-down process. Experimental verification in a pilot plant oven is presented. To ensure food safety, a mandatory regulation requires all poultry processors in the U.S.A to verify that all ready-to-eat products reach a minimum endpoint temperature (71¦C for chicken breast), but no current assay can do a non-invasively inspection of all the samples. The proposed system has the potential for on-line inspection of ready-to-eat meat for food quality and safety.

  19. Numerical Stress Analysis during Cooldown and Compressive Loading in an Imperfect Nb 3Sn Wire

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    d’Hauthuille, Luc; Zhai, Yuhu

    In this paper, high field superconductors are critical to the success of next step magnetic fusion confinement devices such as ITER and DEMO. The low-temperature superconducting material that is currently favored for these applications, Nb 3Sn, is susceptible to performance due to its brittleness and high strain-sensitivity. Under extreme loads, an irreversible degradation in the maximum critical current density has been shown to occur and believed to be strongly influenced by two factors: plasticity and cracked filaments. Cracks in filaments are induced when sufficiently high stress concentrations occur in the wire. In this paper, we explore using finite element analysismore » the impact that voids have on the stress distributions and peak stresses under two loading conditions: transverse compressive loading in a 2D model, and a full cool down phase in a 3D model.« less

  20. Silicon materials task of the low-cost solar array project. Phase 4: Effects of impurities and processing on silicon solar cells

    NASA Technical Reports Server (NTRS)

    Hopkins, R. H.; Hanes, M. H.; Davis, J. R.; Rohatgi, A.; Raichoudhury, P.; Mollenkopf, H. C.

    1981-01-01

    The results of the study form a basis for silicon producers, wafer manufacturers, and cell fabricators to develop appropriate cost-benefit relationships for the use of less pure, less costly solar grade silicon. Cr is highly mobile in silicon even at temperatures as low as 600 C. Contrasting with earlier data for Mo, Ti, and V, Cr concentrations vary from place to place in polycrystalline silicon wafers and the electrically-active Cr concentration in the polysilicon is more than an order of magnitude smaller than would be projected from single crystal impurity data. We hypothesize that Cr diffuses during ingot cooldown after growth, preferentially segregates to grain and becomes electrically deactivated. Accelerated aging data from Ni-contaminated silicon imply that no significant impurity-induced cell performance reduction should be expected over a twenty year device lifetime.

  1. Concepts for a low-vibration and cryogen-free tabletop dilution refrigerator

    NASA Astrophysics Data System (ADS)

    Uhlig, Kurt

    2017-10-01

    The purpose of this article is to describe several concepts of how to cool a modern tabletop dilution refrigerator (DR) with a cryogen-free pulse tube cryocooler (PTC). Tabletop DRs have come more and more into the focus of scientists, recently, because they offer easy access to the mixing chamber mounting plate from all directions and because of their very short cooldown times. However, these milli-Kelvin coolers are precooled with LHe which makes their handling inconvenient and often expensive. In the paper it is explained how a cryocooler can be directly coupled to a DR unit making the use of LHe superfluous. Furthermore, concepts are discussed where a tabletop DR is cooled by a remote PTC; PTC and DR are mounted in separate vacuum containers which are connected by a stainless steel bellows tube. This kind of apparatus would offer an extremely low level of vibration at the mixing chamber mounting plate.

  2. Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mG

    DOE PAGES

    Romanenko, A.; Grassellino, A.; Crawford, A. C.; ...

    2014-12-10

    Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here, we show that a complete expulsion of the magnetic flux can be performed and leads to: (1) record quality factors Q > 2 x 10¹¹ up to accelerating gradient of 22 MV/m; (2) Q ~ 3 x 10¹⁰ at 2 K and 16 MV/m in up to 190 mG magnetic fields. This is achieved by large thermal gradients at the normal/superconducting phase front during the cooldown. Our findingsmore » open up a way to ultra-high quality factors at low temperatures and show an alternative to the sophisticated magnetic shielding implemented in modern superconducting accelerators.« less

  3. Cross-stacked carbon nanotubes assisted self-separation of free-standing GaN substrates by hydride vapor phase epitaxy.

    PubMed

    Wei, Tongbo; Yang, Jiankun; Wei, Yang; Huo, Ziqiang; Ji, Xiaoli; Zhang, Yun; Wang, Junxi; Li, Jinmin; Fan, Shoushan

    2016-06-24

    We report a novel method to fabricate high quality 2-inch freestanding GaN substrate grown on cross-stacked carbon nanotubes (CSCNTs) coated sapphire by hydride vapor phase epitaxy (HVPE). As nanoscale masks, these CSCNTs can help weaken the interface connection and release the compressive stress by forming voids during fast coalescence and also block the propagation of threading dislocations (TDs). During the cool-down process, thermal stress-induced cracks are initiated at the CSCNTs interface with the help of air voids and propagated all over the films which leads to full self-separation of FS-GaN substrate. Raman and photoluminescence spectra further reveal the stress relief and crystalline improvement of GaN with CSCNTs. It is expected that the efficient, low cost and mass-producible technique may enable new applications for CNTs in nitride optoelectronic fields.

  4. Cross-stacked carbon nanotubes assisted self-separation of free-standing GaN substrates by hydride vapor phase epitaxy

    PubMed Central

    Wei, Tongbo; Yang, Jiankun; Wei, Yang; Huo, Ziqiang; Ji, Xiaoli; Zhang, Yun; Wang, Junxi; Li, Jinmin; Fan, Shoushan

    2016-01-01

    We report a novel method to fabricate high quality 2-inch freestanding GaN substrate grown on cross-stacked carbon nanotubes (CSCNTs) coated sapphire by hydride vapor phase epitaxy (HVPE). As nanoscale masks, these CSCNTs can help weaken the interface connection and release the compressive stress by forming voids during fast coalescence and also block the propagation of threading dislocations (TDs). During the cool-down process, thermal stress-induced cracks are initiated at the CSCNTs interface with the help of air voids and propagated all over the films which leads to full self-separation of FS-GaN substrate. Raman and photoluminescence spectra further reveal the stress relief and crystalline improvement of GaN with CSCNTs. It is expected that the efficient, low cost and mass-producible technique may enable new applications for CNTs in nitride optoelectronic fields. PMID:27340030

  5. The liquid nitrogen and supercritical helium cooling loop for the jet pumped divertor cryopump

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Obert, W.; Mayaux, C.; Perinic, G.

    1994-12-31

    A key element for the new experimental phase of the European fusion experiment JET is a new cryopump which will be installed inside the torus in order to pump the new divertor configuration. A forced flow of liquid nitrogen and supercritical helium has been chosen for the cooling of the cryoshields and cryocondensation panels for this cryopump. The reasons for this selection are to minimize the inventory of cryogens (to minimize nuclear heating) good heat transfer conditions and minimum time for transient conditions such as cool-down, regeneration and warm-up. The flow of supercritical helium will be driven by the mainmore » compressor of the refrigerator and enhanced by a dedicated cold ejector. The peak load during the plasma pulse will be absorbed by the high thermal capacity of the bulk supercritical helium inside the cryocondensation panel.« less

  6. Recovering from conflict in romantic relationships: a developmental perspective.

    PubMed

    Salvatore, Jessica E; Kuo, Sally I-Chun; Steele, Ryan D; Simpson, Jeffry A; Collins, W Andrew

    2011-03-01

    This study adopted a developmental perspective on recovery from conflict in romantic relationships. Participants were 73 young adults (target participants), studied since birth, and their romantic partners. A novel observational coding scheme was used to evaluate each participant's degree of conflict recovery, operationalized as the extent to which the participant disengaged from conflict during a 4-min "cool-down" task immediately following a 10-min conflict discussion. Conflict recovery was systematically associated with developmental and dyadic processes. Targets who were rated as securely attached more times in infancy recovered from conflict better, as did their romantic partners. Concurrently, having a romantic partner who displayed better recovery predicted more positive relationship emotions and greater relationship satisfaction. Prospectively, target participants' early attachment security and their partners' degree of conflict recovery interacted to predict relationship stability 2 years later, such that having a partner who recovered from conflict better buffered targets with insecure histories.

  7. Magnetic flux studies in horizontally cooled elliptical superconducting cavities

    DOE PAGES

    Martinello, M.; Checchin, M.; Grassellino, A.; ...

    2015-07-29

    Previous studies on magnetic flux expulsion as a function of cooldown procedures for elliptical superconducting radio frequency (SRF) niobium cavities showed that when the cavity beam axis is placed parallel to the helium cooling flow and sufficiently large thermal gradients are achieved, all magnetic flux could be expelled and very low residual resistance could be achieved. In this paper, we investigate flux trapping for the case of resonators positioned perpendicularly to the helium cooling flow, which is more representative of how SRF cavities are cooled in accelerators and for different directions of the applied magnetic field surrounding the resonator. Wemore » show that different field components have a different impact on the surface resistance, and several parameters have to be considered to fully understand the flux dynamics. A newly discovered phenomenon of concentration of flux lines at the cavity top leading to temperature rise at the cavity equator is presented.« less

  8. Numerical Stress Analysis during Cooldown and Compressive Loading in an Imperfect Nb 3Sn Wire

    DOE PAGES

    d’Hauthuille, Luc; Zhai, Yuhu

    2017-07-11

    In this paper, high field superconductors are critical to the success of next step magnetic fusion confinement devices such as ITER and DEMO. The low-temperature superconducting material that is currently favored for these applications, Nb 3Sn, is susceptible to performance due to its brittleness and high strain-sensitivity. Under extreme loads, an irreversible degradation in the maximum critical current density has been shown to occur and believed to be strongly influenced by two factors: plasticity and cracked filaments. Cracks in filaments are induced when sufficiently high stress concentrations occur in the wire. In this paper, we explore using finite element analysismore » the impact that voids have on the stress distributions and peak stresses under two loading conditions: transverse compressive loading in a 2D model, and a full cool down phase in a 3D model.« less

  9. Nonlinear effects in thermal stress analysis of a solid propellant rocket motor

    NASA Technical Reports Server (NTRS)

    Francis, E. C.; Peeters, R. L.; Murch, S. A.

    1976-01-01

    Direct characterization procedures were used to determine the relaxation modulus as a function of time, temperature, and state of strain. Using the quasi-elastic method of linearviscoelasticity, these properties were employed in a finite element computer code to analyze a thick-walled, nonlinear viscoelastic cylinder in the state of plane strain bonded to a thin (but stiff) elastic casing and subjected to slow thermal cooling. The viscoelastic solution is then expressed as a sequence of elastic finite element solutions. The strain-dependent character of the relaxation modulus is included by replacing the single relaxation curve used in the linear viscoelastic theory by a family of relaxation functions obtained at various strain levels. These functions may be regarded as a collection of stress histories or responses to specific loads (in this case, step strains) with which the cooldown solution is made to agree by iterations on the modulus and strain level.

  10. HIGH-TEMPERATURE SAFETY TESTING OF IRRADIATED AGR-1 TRISO FUEL

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stempien, John D.; Demkowicz, Paul A.; Reber, Edward L.

    High-Temperature Safety Testing of Irradiated AGR-1 TRISO Fuel John D. Stempien, Paul A. Demkowicz, Edward L. Reber, and Cad L. Christensen Idaho National Laboratory, P.O. Box 1625 Idaho Falls, ID 83415, USA Corresponding Author: john.stempien@inl.gov, +1-208-526-8410 Two new safety tests of irradiated tristructural isotropic (TRISO) coated particle fuel have been completed in the Fuel Accident Condition Simulator (FACS) furnace at the Idaho National Laboratory (INL). In the first test, three fuel compacts from the first Advanced Gas Reactor irradiation experiment (AGR-1) were simultaneously heated in the FACS furnace. Prior to safety testing, each compact was irradiated in the Advanced Testmore » Reactor to a burnup of approximately 15 % fissions per initial metal atom (FIMA), a fast fluence of 3×1025 n/m2 (E > 0.18 MeV), and a time-average volume-average (TAVA) irradiation temperature of about 1020 °C. In order to simulate a core-conduction cool-down event, a temperature-versus-time profile having a peak temperature of 1700 °C was programmed into the FACS furnace controllers. Gaseous fission products (i.e., Kr-85) were carried to the Fission Gas Monitoring System (FGMS) by a helium sweep gas and captured in cold traps featuring online gamma counting. By the end of the test, a total of 3.9% of an average particle’s inventory of Kr-85 was detected in the FGMS traps. Such a low Kr-85 activity indicates that no TRISO failures (failure of all three TRISO layers) occurred during the test. If released from the compacts, condensable fission products (e.g., Ag-110m, Cs-134, Cs-137, Eu-154, Eu-155, and Sr-90) were collected on condensation plates fitted to the end of the cold finger in the FACS furnace. These condensation plates were then analyzed for fission products. In the second test, five loose UCO fuel kernels, obtained from deconsolidated particles from an irradiated AGR-1 compact, were heated in the FACS furnace to a peak temperature of 1600 °C. This test had two primary goals. First, the test was intended to assess the retention of fission products in loose kernels without the effects of the other TRISO layers (buffer, IPyC, SiC, and OPyC) or the graphitic matrix material comprising the compact. Second, this test served as an evaluation of the FACS fission product condensation plate collection efficiency.« less

  11. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lisowski, Darius D.; Kraus, Adam R.; Bucknor, Matthew D.

    A 1/2 scale test facility has been constructed at Argonne National Laboratory to study the heat removal performance and natural circulation flow patterns in a Reactor Cavity Cooling System (RCCS). Our test facility, the Natural convection Shutdown heat removal Test Facility (NSTF), supports the broader goal of developing an inherently safe and fully passive ex-vessel decay heat removal for advanced reactor designs. The project, initiated in 2010 to support the Advanced Reactor Technologies (ART), Small Modular Reactor (SMR), and Next Generation Nuclear Plant (NGNP) programs, has been conducting experimental operations since early 2014. The following paper provides a summary ofmore » some primary design features of the 26-m tall test facility along with a description of the data acquisition suite that guides our experimental practices. Specifics of the distributed fiber optic temperature measurements will be discussed, which introduces an unparalleled level of data density that has never before been implemented in a large scale natural circulation test facility. Results from our test series will then be presented, which provide insight into the thermal hydraulic behavior at steady-state and transient conditions for varying heat flux levels and exhaust chimney configuration states. (C) 2016 Elsevier B.V. All rights reserved.« less

  12. HepPar1-Positive Circulating Microparticles Are Increased in Subjects with Hepatocellular Carcinoma and Predict Early Recurrence after Liver Resection

    PubMed Central

    Abbate, Valeria; Marcantoni, Margherita; Giuliante, Felice; Vecchio, Fabio M.; Gatto, Ilaria; Mele, Caterina; Saviano, Antonio; Arciuolo, Damiano; Gaetani, Eleonora; Ferrari, Maria C.; Giarretta, Igor; Ardito, Francesco; Riccardi, Laura; Nicoletti, Alberto; Ponziani, Francesca R.; Gasbarrini, Antonio; Pompili, Maurizio; Pola, Roberto

    2017-01-01

    Circulating microparticles (MPs) are novel potential biomarkers in cancer patients. Their role in hepatocellular carcinoma (HCC) is under intensive investigation. In this study, we tested the hypothesis that MPs expressing the antigen HepPar1 are increased in the blood of subjects with HCC and may serve as markers of early recurrence after liver resection (LR). We studied 15 patients affected by HCC undergoing LR, and used flow cytometry to assess the number of circulating HepPar1+ MPs. Ten subjects without HCC (five with liver cirrhosis and five with healthy livers) were used as controls. After LR, HCC patients underwent a follow-up to check for early recurrence, which occurred in seven cases. The number of circulating HepPar1+ MPs was significantly higher in subjects affected by HCC, compared to individuals without cancer (p < 0.01). We also found that, among HCC patients, the number of circulating HepPar1+ MPs, measured before LR, was significantly higher in those who displayed early recurrence compared to those without recurrence (p = 0.02). Of note, other types of circulating MPs, such as those derived from endothelial cells (CD144+) or those produced by the activated endothelium (CD144+/CD62+), were not associated with HCC, nor could they predict HCC recurrence. HepPar1+ MPs deserve further investigation as novel biomarkers of disease and prognosis in HCC patients. PMID:28498353

  13. Public speaking stress-induced neuroendocrine responses and circulating immune cell redistribution in irritable bowel syndrome.

    PubMed

    Elsenbruch, Sigrid; Lucas, Ayscha; Holtmann, Gerald; Haag, Sebastian; Gerken, Guido; Riemenschneider, Natalie; Langhorst, Jost; Kavelaars, Annemieke; Heijnen, Cobi J; Schedlowski, Manfred

    2006-10-01

    Augmented neuroendocrine stress responses and altered immune functions may play a role in the manifestation of functional gastrointestinal (GI) disorders. We tested the hypothesis that IBS patients would demonstrate enhanced psychological and endocrine responses, as well as altered stress-induced redistribution of circulating leukocytes and lymphocytes, in response to an acute psychosocial stressor when compared with healthy controls. Responses to public speaking stress were analyzed in N = 17 IBS patients without concurrent psychiatric conditions and N = 12 healthy controls. At baseline, immediately following public speaking, and after a recovery period, state anxiety, acute GI symptoms, cardiovascular responses, serum cortisol and plasma adrenocorticotropic hormone (ACTH) were measured, and numbers of circulating leukocytes and lymphocyte subpopulations were analyzed by flow cytometry. Public speaking led to significant cardiovascular activation, a significant increase in ACTH, and a redistribution of circulating leukocytes and lymphocyte subpopulations, including significant increases in natural killer cells and cytotoxic/suppressor T cells. IBS patients demonstrated significantly greater state anxiety both at baseline and following public speaking. However, cardiovascular and endocrine responses, as well as the redistribution of circulating leukocytes and lymphocyte subpopulations after public speaking stress, did not differ for IBS patients compared with controls. In IBS patients without psychiatric comorbidity, the endocrine response as well as the circulation pattern of leukocyte subpopulations to acute psychosocial stress do not differ from healthy controls in spite of enhanced emotional responses. Future studies should discern the role of psychopathology in psychological and biological stress responses in IBS.

  14. Influence of depression and anxiety on circulating endothelial progenitor cells in patients with acute coronary syndromes.

    PubMed

    Felice, Francesca; Di Stefano, Rossella; Pini, Stefano; Mazzotta, Gianfranco; Bovenzi, Francesco M; Bertoli, Daniele; Abelli, Marianna; Borelli, Lucia; Cardini, Alessandra; Lari, Lisa; Gesi, Camilla; Michi, Paola; Morrone, Doralisa; Gnudi, Luigi; Balbarini, Alberto

    2015-05-01

    Circulating endothelial progenitor cells (EPCs) are related to endothelial function and progression of coronary artery disease. There is evidence of decreased numbers of circulating EPCs in patients with a current episode of major depression. We investigated the relationships between the level of circulating EPCs and depression and anxiety in patients with acute coronary syndrome (ACS). Patients with ACS admitted to three Cardiology Intensive Care Units were evaluated by the SCID-I to determine the presence of lifetime and/or current mood and anxiety disorders according to DSM-IV criteria. The EPCs were defined as CD133(+) CD34(+) KDR(+) and evaluated by flow cytometry. All patients underwent standardized cardiological and psychopathological evaluations. Parametric and nonparametric statistical tests were performed where appropriate. Out of 111 ACS patients, 57 were found to have a DSM-IV lifetime or current mood or anxiety disorder at the time of the inclusion in the study. The ACS group with mood or anxiety disorders showed a significant decrease in circulating EPC number compared with ACS patients without affective disorders. In addition, EPC levels correlated negatively with severity of depression and anxiety at index ACS episode. The current study indicates that EPCs circulate in decreased numbers in ACS patients with depression or anxiety and, therefore, contribute to explore new perspectives in the pathophysiology of the association between cardiovascular disorders and affective disorders. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Mechanical Characterization of Thermomechanical Matrix Residual Stresses Incurred During MMC Processing

    NASA Technical Reports Server (NTRS)

    Castelli, Michael G.

    1998-01-01

    In recent years, much effort has been spent examining the residual stress-strain states of advanced composites. Such examinations are motivated by a number of significant concerns that affect composite development, processing, and analysis. The room-temperature residual stress states incurred in many advanced composite systems are often quite large and can introduce damage even prior to the first external mechanical loading of the material. These stresses, which are induced during the cooldown following high-temperature consolidation, result from the coefficient of thermal expansion mismatch between the fiber and matrix. Experimental techniques commonly used to evaluate composite internal residual stress states are non-mechanical in nature and generally include forms of x-ray and neutron diffraction. Such approaches are usually complex, involving a number of assumptions and limitations associated with a wide range of issues, including the depth of penetration, the volume of material being assessed, and erroneous effects associated with oriented grains. Furthermore, and more important to the present research, these techniques can assess only "single time" stress in the composite. That is, little, if any, information is obtained that addresses the time-dependent point at which internal stresses begin to accumulate, the manner in which the accumulation occurs, and the presiding relationships between thermoelastic, thermoplastic, and thermoviscous behaviors. To address these critical issues, researchers at the NASA Lewis Research Center developed and implemented an innovative mechanical test technique to examine in real time, the time-dependent thermomechanical stress behavior of a matrix alloy as it went through a consolidation cycle.

  16. Bonding and Integration Technologies for Silicon Carbide Based Injector Components

    NASA Technical Reports Server (NTRS)

    Halbig, Michael C.; Singh, Mrityunjay

    2008-01-01

    Advanced ceramic bonding and integration technologies play a critical role in the fabrication and application of silicon carbide based components for a number of aerospace and ground based applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. Ceramic to ceramic diffusion bonding and ceramic to metal brazing technologies are being developed for this injector application. For the diffusion bonding, titanium interlayers (PVD and foils) were used to aid in the joining of silicon carbide (SiC) substrates. The influence of such variables as surface finish, interlayer thickness (10, 20, and 50 microns), processing time and temperature, and cooling rates were investigated. Microprobe analysis was used to identify the phases in the bonded region. For bonds that were not fully reacted an intermediate phase, Ti5Si3Cx, formed that is thermally incompatible in its thermal expansion and caused thermal stresses and cracking during the processing cool-down. Thinner titanium interlayers and/or longer processing times resulted in stable and compatible phases that did not contribute to microcracking and resulted in an optimized microstructure. Tensile tests on the joined materials resulted in strengths of 13-28 MPa depending on the SiC substrate material. Non-destructive evaluation using ultrasonic immersion showed well formed bonds. For the joining technology of brazing Kovar fuel tubes to silicon carbide, preliminary development of the joining approach has begun. Various technical issues and requirements for the injector application are addressed.

  17. Effects of Health Qigong Exercises on Relieving Symptoms of Parkinson's Disease.

    PubMed

    Liu, Xiao Lei; Chen, Shihui; Wang, Yongtai

    2016-01-01

    The purpose of this study was to investigate the effects of Health Qigong on the treatment and releasing symptoms of Parkinson's disease (PD). Fifty-four moderate PD patients ( N = 54) were randomly divided into experimental and control groups. Twenty-eight PD patients were placed in the experimental group in which the prescribed medication plus Health Qigong exercise will be used as intervention. The other 26 PD patients as the control group were treated only with regular medication. Ten-week intervention had been conducted for the study, and participants completed the scheduled exercises 5 times per week for 60 minutes each time (10 minutes for warm-up, 40 minutes for the exercise, and 10 minutes for cooldown). Data which included the muscle hardness, one-legged blind balance, physical coordination, and stability was collected before, during, and after the intervention. Comparisons were made between the experimental and control groups through the Repeated Measures ANOVA. The results showed that PD patients demonstrate a significant improvement in muscle hardness, the timed "up and go," balance, and hand-eye coordination (the turn-over-jars test). There were no significant differences between the two groups in gender, age, and course of differences ( P < 0.05). The study concluded that Health Qigong exercises could reduce the symptoms of Parkinson's disease and improve the body functions of PD patients in both the mild and moderate stages. It can be added as an effective treatment of rehabilitation therapy for PD.

  18. Effects of Health Qigong Exercises on Relieving Symptoms of Parkinson's Disease

    PubMed Central

    Liu, Xiao Lei; Wang, Yongtai

    2016-01-01

    The purpose of this study was to investigate the effects of Health Qigong on the treatment and releasing symptoms of Parkinson's disease (PD). Fifty-four moderate PD patients (N = 54) were randomly divided into experimental and control groups. Twenty-eight PD patients were placed in the experimental group in which the prescribed medication plus Health Qigong exercise will be used as intervention. The other 26 PD patients as the control group were treated only with regular medication. Ten-week intervention had been conducted for the study, and participants completed the scheduled exercises 5 times per week for 60 minutes each time (10 minutes for warm-up, 40 minutes for the exercise, and 10 minutes for cooldown). Data which included the muscle hardness, one-legged blind balance, physical coordination, and stability was collected before, during, and after the intervention. Comparisons were made between the experimental and control groups through the Repeated Measures ANOVA. The results showed that PD patients demonstrate a significant improvement in muscle hardness, the timed “up and go,” balance, and hand-eye coordination (the turn-over-jars test). There were no significant differences between the two groups in gender, age, and course of differences (P < 0.05). The study concluded that Health Qigong exercises could reduce the symptoms of Parkinson's disease and improve the body functions of PD patients in both the mild and moderate stages. It can be added as an effective treatment of rehabilitation therapy for PD. PMID:27891159

  19. FXR activation by obeticholic acid or nonsteroidal agonists induces a human-like lipoprotein cholesterol change in mice with humanized chimeric liver.

    PubMed

    Papazyan, Romeo; Liu, Xueqing; Liu, Jingwen; Dong, Bin; Plummer, Emily M; Lewis, Ronald D; Roth, Jonathan D; Young, Mark A

    2018-06-01

    Obeticholic acid (OCA) is a selective farnesoid X receptor (FXR) agonist that regulates bile acid and lipid metabolism. FXR activation induces distinct changes in circulating cholesterol among animal models and humans. The mechanistic basis of these effects has been elusive because of difficulties in studying lipoprotein homeostasis in mice, which predominantly package circulating cholesterol in HDLs. Here, we tested the effects of OCA in chimeric mice whose livers are mostly composed (≥80%) of human hepatocytes. Chimeric mice exhibited a human-like ratio of serum LDL cholesterol (LDL-C) to HDL cholesterol (HDL-C) at baseline. OCA treatment in chimeric mice increased circulating LDL-C and decreased circulating HDL-C levels, demonstrating that these mice closely model the cholesterol effects of FXR activation in humans. Mechanistically, OCA treatment increased hepatic cholesterol in chimeric mice but not in control mice. This increase correlated with decreased SREBP-2 activity and target gene expression, including a significant reduction in LDL receptor protein. Cotreatment with atorvastatin reduced total cholesterol, rescued LDL receptor protein levels, and normalized serum LDL-C. Treatment with two clinically relevant nonsteroidal FXR agonists elicited similar lipoprotein and hepatic changes in chimeric mice, suggesting that the increase in circulating LDL-C is a class effect of FXR activation.

  20. Effect of circulating tissue factor on hypercoagulability in type 2 diabetes mellitus studied by rheometry and dielectric blood coagulometry

    PubMed Central

    Uchimura, Isao; Kaibara, Makoto; Nagasawa, Masayuki; Hayashi, Yoshihito

    2016-01-01

    Background: Hypercoagulability in type 2 diabetes mellitus (T2DM) patients increases their risk of cardiovascular diseases. Objective: The aim of this work was to investigate the hypercoagulation mechanism in T2DM patients in terms of circulating tissue factor (TF). Methods: Whole blood coagulation tests by damped oscillation rheometry and dielectric blood coagulometry (DBCM) were performed. Results: The average coagulation time was significantly shorter for T2DM patients than for healthy controls. In vitro addition of either anti-TF or anti-activated factor VII (FVIIa) antibody to hypercoagulable blood samples prolonged coagulation times for one group of patients, while coagulation times remained short for another group. The levels of circulating TF were estimated in the former group by measuring the coagulation times for blood samples from healthy subjects with addition of various concentrations of TF and comparing them with the coagulation times for the group. The results indicated that the levels of circulating TF were on the order of subpicomolar at most. Conclusions: Circulating TF is at least partially responsible for a hypercoagulable group of T2DM patients, while an abnormality in the intrinsic coagulation pathway probably occurs in the other group. PMID:27858671

  1. Linking the South Atlantic Meridional Overturning Circulation and the Global Monsoons

    NASA Astrophysics Data System (ADS)

    Lopez, H.; Dong, S.; Goni, G. J.; Lee, S. K.

    2016-02-01

    This study tested the hypothesis whether low frequency decadal variability of the South Atlantic meridional heat transport (SAMHT) influences decadal variability of the global monsoons. A multi-century run from a state-of-the-art coupled general circulation model is used as basis for the analysis. Our findings indicate that multi-decadal variability of the South Atlantic Ocean plays a key role in modulating atmospheric circulation via interhemispheric changes in Atlantic Ocean heat content. Weaker SAMHT produces anomalous ocean heat divergence over the South Atlantic resulting in negative ocean heat content anomaly about 15 years later. This, in turn, forces a thermally direct anomalous interhemispheric Hadley circulation in the atmosphere, transporting heat from the northern hemisphere (NH) to the southern hemisphere (SH) and moisture from the SH to the NH, thereby intensify (weaken) summer (winter) monsoon in the NH and winter (summer) monsoon in the SH. Results also show that anomalous atmospheric eddies, both transient and stationary, transport heat northward in both hemispheres producing eddy heat flux convergence (divergence) in the NH (SH) around 15-30°, reinforcing the anomalous Hadley circulation. Overall, SAMHT decadal variability leads its atmospheric response by about 15 years, suggesting that the South Atlantic is a potential predictor of global climate variability.

  2. Development of the Technologies for Stabilization Treatment of the Water of the Recycling Cooling Systems at Thermal Power Plants

    NASA Astrophysics Data System (ADS)

    Vlasov, S. M.; Chichirova, N. D.; Chichirov, A. A.; Vlasova, A. Yu.; Filimonova, A. A.; Prosvirnina, D. V.

    2018-02-01

    A turbine-condensate cooling system is one of the less stable and most hard-to-control systems of maintaining optimal water chemistry. A laboratory recycling cooling water test facility, UVO-0.3, was developed for physical simulation of innovative zero-discharge water chemistry conditions and improvement of technological flowcharts of stabilization treatment of the initial and circulating water of the recycling cooling systems at thermal power plants. Experiments were conducted in the UVO-0.3 facility to investigate the processes that occur in the recycling water supply system and master new technologies of stabilization of the initial and circulating water. It is shown that, when using untreated initial water, scaling cannot be prevented even under low concentration levels. The main reason for the activation of scale depositing is the desorption of carbon dioxide that results in alkalization of the circulating water and, as a consequence, a displacement of the chemical reaction equilibrium towards the formation of slightly soluble hardness ions. Some techniques, viz., liming and alkalization of the initial water and the by-pass treatment of the circulating water, are considered. New engineering solutions have been developed for reducing the amount of scale-forming substances in the initial and circulating water. The best results were obtained by pretreating the initial water with alkalizing agents and simultaneously bypassing and treating part of the circulating water. The obtained experimental data underlie the process flowcharts of stabilization treatment of the initial and circulating TPP water that ensure scale-free and noncorrosive operation and meet the corresponding environmental requirements. Under the bypassing, the specific rates of the agents and the residual hardness are reduced compared with the conventional pretreatment.

  3. Canine parvovirus (CPV-2) variants circulating in Nigerian dogs

    PubMed Central

    Apaa, T. T.; Daly, J. M.; Tarlinton, R. E.

    2016-01-01

    Canine parvovirus type 2 (CPV-2) is a highly contagious viral disease with three variants (CPV-2a, CPV-2b and CPV-2c) currently circulating in dogs worldwide. The main aim of this study was to determine the prevalent CPV-2 variant in faecal samples from 53 dogs presenting with acute gastroenteritis suspected to be and consistent with CPV-2 to Nigerian Veterinary Clinics in 2013–2014. Seventy-five per cent of these dogs tested positive for CPV-2 in a commercial antigen test and/or by PCR. Partial sequencing of the VP2 gene of six of these demonstrated them to be CPV-2a. Most of the dogs (60 per cent) were vaccinated, with 74 per cent of them puppies less than six months old. PMID:27933190

  4. Crosswinds Effect on the Thermal Performance of Wet Cooling Towers Under Variable Operating Conditions

    NASA Astrophysics Data System (ADS)

    Chen, You Liang; Shi, Yong Feng; Hao, Jian Gang; Chang, Hao; Sun, Feng Zhong

    2018-01-01

    In order to quantitatively analyze the influence of the variable operating parameters on the cooling performance of natural draft wet cooling towers (NDWCTs), a hot model test system was set up with adjustable ambient temperature and humidity, circulating water flowrate and temperature. In order to apply the hot model test results to the real tower, the crosswind Froude number is defined. The results show that the crosswind has a negative effect on the thermal performance of the cooling tower, and there is a critical crosswind velocity corresponding to the lowest cooling efficiency. According to the crosswind Froude number similarity, when the ambient temperature decreases, or the circulating water flowrate and temperature increase, the cooling tower draft force will increase, and the critical crosswind velocity will increase correspondingly.

  5. Thermograpic study of upper extremities in patients with cerebral palsy

    NASA Astrophysics Data System (ADS)

    Lampe, R.; Kawelke, S.; Mitternacht, J.; Turova, V.; Blumenstein, T.; Alves-Pinto, A.

    2015-03-01

    Trophic disorders like reduced skin blood circulation are well-known epiphenomenon of cerebral palsy (CP). They can influence quality of life and can lead to skin damages and, as a consequence, to decubitus. Therefore, it is important to analyse temperature regulation in patients with CP. Thermal imaging camera FLIR BCAM SD was used to study the dependency of skin blood circulation in upper extremities of patients with CP on hand dominance, hand force and hand volume. The hand force was evaluated using a conventional dynamometer. The hand volume was measured with a volumeter. A cold stress test for hands was applied in 22 patients with CP and 6 healthy subjects. The warming up process after the test was recorded with the thermal camera. It was confirmed that the hands of patients warm up slower comparing to healthy persons. The patients' working hands warm up faster than non-working ones. A slight correlation was established between the hand grip force of the working hands and their warm up time. No correlation was found between the warming up time and the volume of the hand. The results confirm our assumption that there is a connection of peripheral blood circulation to upper limb motor functions.

  6. Analytical detection of influenza A(H3N2)v and other A variant viruses from the USA by rapid influenza diagnostic tests.

    PubMed

    Balish, Amanda; Garten, Rebecca; Klimov, Alexander; Villanueva, Julie

    2013-07-01

    The performance of rapid influenza diagnostic tests (RIDTs) that detect influenza viral nucleoprotein (NP) antigen has been reported to be variable. Recent human infections with variant influenza A viruses that are circulating in pigs prompted the investigation of the analytical reactivity of RIDTs with these variant viruses. To determine analytical reactivity of seven FDA-cleared RIDTs with influenza A variant viruses in comparison with the reactivity with recently circulating seasonal influenza A viruses. Tenfold serial dilutions of cell culture-grown seasonal and variant influenza A viruses were prepared and tested in duplicate with seven RIDTs. All RIDTs evaluated in this study detected the seasonal influenza A(H3N2) virus, although detection limits varied among assays. All but one examined RIDT identified the influenza A(H1N1)pdm09 virus. However, only four of seven RIDTs detected all influenza A(H3N2)v, A(H1N2)v, and A(H1N1)v viruses. Reduced sensitivity of RIDTs to variant influenza viruses may be due to amino acid differences between the NP proteins of seasonal viruses and the NP proteins from viruses circulating in pigs. Clinicians should be aware of the limitations of RIDTs to detect influenza A variant viruses. Specimens from patients with influenza-like illness in whom H3N2v is suspected should be sent to public health laboratories for additional diagnostic testing. Published 2012. This article is a US Government work and is in the public domain in the USA.

  7. Myasthenic syndrome: effect of choline, plasmapheresis and tests for circulating factor.

    PubMed Central

    Kranz, H; Caddy, D J; Williams, A M; Gay, W

    1980-01-01

    In a patient with myasthenic syndrome neuro-muscular transmission was characterised by depression and facilitation. The relative extent of these two processes varied between muscles, and in the one muscle with time. Guanidine HCl treatment corrected the electrophysiological defect. Oral choline increased muscle action potential amplitude in response to single shocks. Intravenous choline produced features indicating cholinergic autonomic stimulation. Pimozide and plasmapheresis had no effect. Animal in-vivo and in-vitro studies performed to detect a circulating factor which interferes with neuro-muscular transmission were negative. PMID:6110709

  8. Results of the Winter Flow Experiments Conducted on December 7-8, February 7-8, and February 28-29, 1992

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dressen, Donald S.; Beikmann, Mel

    A winter flow regime has been proposed as a method of maintaining a non-freezing environment following the loss of circulation in the HDR Reservoir test facility when ambient temperature is below 32 °F. The regime, as presently envisioned, would automatically convert the surface facility from reservoir circulation to low rate reservoir production through the entire operating system except the EE-3A wellhead, the EE-2A x-mas tree, and the make-up/feed pump/water supply system.

  9. Monitoring estuarine circulation and ocean waste dispersion using an integrated satellite-aircraft-drogue approach. [Continental Shelf and Delaware Bay

    NASA Technical Reports Server (NTRS)

    Klemas, V. (Principal Investigator); Davis, G. R.; Wang, H.

    1975-01-01

    The author has identified the following significant results. An integrated satellite-aircraft-drogue approach was developed which employs remotely tracked expendable drogues together with satellite and aircraft observations of oil slicks, waste plumes, and natural tracers, such as suspended sediment. Tests conducted on the Continental Shelf and in Delaware Bay indicate that the system provides a cost effective means of monitoring current circulation and verifying oil slick and ocean waste dispersion models even under severe environmental conditions.

  10. Circulation, Water Temperature, and Larval Settlement Over the Inner Continental Shelves of the Santa Barbara Channel, California

    NASA Astrophysics Data System (ADS)

    Fewings, M. R.; Washburn, L.; Ohlmann, C.; Blanchette, C.; Caselle, J.; Gotschalk, C.

    2008-12-01

    We use seven-year time series of wind stress, water velocity, and temperature in 15-18 m water depth to describe the circulation and water temperature over the inner continental shelves of the Channel Islands and California mainland in the Santa Barbara Basin. This area is strongly influenced by the California Current upwelling system. In turn, the water circulation in the Santa Barbara Basin influences the local marine ecosystem by affecting the water temperature and the supply of nutrients and larval fish and invertebrates. Larvae and nutrients traveling from the coast to the open ocean and back again must somehow pass through the inner shelf. The water circulation over the inner continental shelf of the Northern Channel Islands has not been described. Due to the shallowness of the water, an inner shelf has different physical dynamics than either the surfzone or the middle and outer continental shelf. We discuss the relative importance of upwelling- favorable along-shelf winds and of cross-shelf winds as forcing mechanisms for coastal upwelling circulations over the inner shelf; test whether the cross-shelf wind stress and surface gravity waves are important for cross-shelf circulation in the Santa Barbara Basin; and describe the subtidal patterns of water temperature, stratification, and velocity around the Channel Islands and their relation to observed larval settlement patterns. Cross-shelf circulation and the movement of water masses into and out of the Basin have implications for settlement and recruitment of many coastal species, including the economically important kelp rockfish, kelp bass, and sea urchin. Understanding the circulation of the Santa Barbara Basin and its inner shelves is a precursor to determining the source locations of the planktonic larvae. That information on source locations is essential for the design, siting, and assessment of existing and future marine protected areas in California and elsewhere.

  11. Next-generation sequencing of circulating tumor DNA to predict recurrence in triple-negative breast cancer patients with residual disease after neoadjuvant chemotherapy.

    PubMed

    Chen, Yu-Hsiang; Hancock, Bradley A; Solzak, Jeffrey P; Brinza, Dumitru; Scafe, Charles; Miller, Kathy D; Radovich, Milan

    2017-01-01

    Next-generation sequencing to detect circulating tumor DNA is a minimally invasive method for tumor genotyping and monitoring therapeutic response. The majority of studies have focused on detecting circulating tumor DNA from patients with metastatic disease. Herein, we tested whether circulating tumor DNA could be used as a biomarker to predict relapse in triple-negative breast cancer patients with residual disease after neoadjuvant chemotherapy. In this study, we analyzed samples from 38 early-stage triple-negative breast cancer patients with matched tumor, blood, and plasma. Extracted DNA underwent library preparation and amplification using the Oncomine Research Panel consisting of 134 cancer genes, followed by high-coverage sequencing and bioinformatics. We detected high-quality somatic mutations from primary tumors in 33 of 38 patients. TP53 mutations were the most prevalent (82%) followed by PIK3CA (16%). Of the 33 patients who had a mutation identified in their primary tumor, we were able to detect circulating tumor DNA mutations in the plasma of four patients (three TP53 mutations, one AKT1 mutation, one CDKN2A mutation). All four patients had recurrence of their disease (100% specificity), but sensitivity was limited to detecting only 4 of 13 patients who clinically relapsed (31% sensitivity). Notably, all four patients had a rapid recurrence (0.3, 4.0, 5.3, and 8.9 months). Patients with detectable circulating tumor DNA had an inferior disease free survival ( p  < 0.0001; median disease-free survival: 4.6 mos. vs. not reached; hazard ratio = 12.6, 95% confidence interval: 3.06-52.2). Our study shows that next-generation circulating tumor DNA sequencing of triple-negative breast cancer patients with residual disease after neoadjuvant chemotherapy can predict recurrence with high specificity, but moderate sensitivity. For those patients where circulating tumor DNA is detected, recurrence is rapid.

  12. Detection and capture of single circulating melanoma cells using photoacoustic flowmetry

    NASA Astrophysics Data System (ADS)

    O'Brien, Christine; Mosley, Jeffrey; Goldschmidt, Benjamin S.; Viator, John A.

    2010-02-01

    Photoacoustic flowmetry has been used to detect single circulating melanoma cells in vitro. Circulating melanoma cells are those cells that travel in the blood and lymph systems to create secondary tumors and are the hallmark of metastasis. This technique involves taking blood samples from patients, separating the white blood and melanoma cells from whole blood and irradiating them with a pulsed laser in a flowmetry set up. Rapid, visible wavelength laser pulses on the order of 5 ns can induce photoacoustic waves in melanoma cells due to their melanin content, while surrounding white blood cells remain acoustically passive. We have developed a system that identifies rare melanoma cells and captures them in 50 microliter volumes using suction applied near the photoacoustic detection chamber. The 50 microliter sample is then diluted and the experiment is repeated using the new sample until only a melanoma cell remains. We have tested this system on dyed microspheres ranging in size from 300 to 500 microns. Capture of circulating melanoma cells may provide the opportunity to study metastatic cells for basic understanding of the spread of cancer and to optimize patient specific therapies.

  13. On the Use of Satellite Altimetry to Detect Ocean Circulation's Magnetic Signals

    NASA Astrophysics Data System (ADS)

    Saynisch, J.; Irrgang, C.; Thomas, M.

    2018-03-01

    Oceanic magnetic signals are sensitive to ocean velocity, salinity, and heat content. The detection of respective signals with global satellite magnetometers would pose a very valuable source of information. While tidal magnetic fields are already detected, electromagnetic signals of the ocean circulation still remain unobserved from space. We propose to use satellite altimetry to construct proxy magnetic signals of the ocean circulation. These proxy time series could subsequently be fitted to satellite magnetometer data. The fitted data could be removed from the observations or the fitting constants could be analyzed for physical properties of the ocean, e.g., the heat budget. To test and evaluate this approach, synthetic true and proxy magnetic signals are derived from a global circulation model of the ocean. Both data sets are compared in dependence of location and time scale. We study and report when and where the proxy data describe the true signal sufficiently well. Correlations above 0.6 and explained variances of above 80% can be reported for large parts of the Antarctic ocean, thus explaining the major part of the global, subseasonal magnetic signal.

  14. Sustainable water desalination and electricity generation in a separator coupled stacked microbial desalination cell with buffer free electrolyte circulation.

    PubMed

    Chen, Xi; Liang, Peng; Wei, Zhimou; Zhang, Xiaoyuan; Huang, Xia

    2012-09-01

    A separator coupled circulation stacked microbial desalination cell (c-SMDC-S) was constructed to stabilize the pH imbalances in MDCs without buffer solution and achieved the stable desalination. The long-term operation of c-SMDC-S, regular stacked MDC (SMDC) and no separator coupled circulation SMDC (c-SMDC) were tested. The SMDC and c-SMDC could only stably operate for 1 week and 1 month owing to dramatic anolyte pH decrease and serious biofilm growth on the air cathode, respectively. The c-SMDC-S gained in anolyte alkalinity and operated stably for about 60 days without the thick biofilm growth on cathode. Besides, the chemical oxygen demand removal and coulombic efficiency were 64 ± 6% and 30 ± 2%, higher than that of SMDC and c-SMDC, respectively. It was concluded that the circulation of alkalinity could remove pH imbalance while the separator could expand the operation period and promote the conversion of organic matter to electricity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Circulating GLP-1 in infants born small-for-gestational-age: breast-feeding versus formula-feeding.

    PubMed

    Díaz, M; Bassols, J; Sebastiani, G; López-Bermejo, A; Ibáñez, L; de Zegher, F

    2015-10-01

    Prenatal growth restraint associates with the risk for later diabetes, particularly if such restraint is followed by postnatal formula-feeding (FOF) rather than breast-feeding (BRF). Circulating incretins can influence the neonatal programming of hypothalamic setpoints for appetite and energy expenditure, and are thus candidate mediators of the long-term effects exerted by early nutrition. We have tested this concept by measuring (at birth and at age 4 months) the circulating concentrations of glucagon-like peptide-1 (GLP-1) in BRF infants born appropriate-for-gestational-age (AGA; n=63) and in small-for-gestational-age (SGA) infants receiving either BRF (n=28) or FOF (n=26). At birth, concentrations of GLP-1 were similar in AGA and SGA infants. At 4 months, pre-feeding GLP-1 concentrations were higher than at birth; SGA-BRF infants had GLP-1 concentrations similar to those in AGA-BRF infants but SGA-FOF infants had higher concentrations. In conclusion, nutrition appears to influence the circulating GLP-1 concentrations in SGA infants and may thereby modulate long-term diabetes risk.

  16. The Kmif (Kveim-induced macrophage migration inhibition factor) test in sarcoidosis

    PubMed Central

    Williams, W. Jones; Pioli, E.; Jones, D. J.; Dighero, M.

    1972-01-01

    Circulating lymphocytes from 30 patients with sarcoidosis when stimulated in vitro with Kveim-induced macrophage migration factor, the Kmif test, produced a guinea-pig macrophage migration inhibition factor in 21 of 30 cases (70%). In those patients not on steroids the results showed a good correlation with the cutaneous Kveim test. One positive test was found in 16 normal subjects. Our results suggest that the Kmif test may prove a useful rapid alternative to the Kveim test. PMID:4675181

  17. Reliability of Tin Silver Copper and mixed solders under variable loading conditions

    NASA Astrophysics Data System (ADS)

    Jaradat, Younis

    Industry use of lead free solder joints necessitates accurate modeling in predicting life in service. Yet, current extrapolations of accelerated test results do not actuate realistic conditions. This research focuses on joint properties of Pb-mixed and Pb-free solder alloys in order to explain material behavior subject to certain test conditions, i.e., varying cycling amplitudes. Additionally, this research will begin with extensive studies on backward compatible solder joints from the material's behavior to its reliability under displacement and load controlled fatigue tests. We address the evolution of the joint's microstructure ergo its properties and performance (mixed solder joints). The present work reports results of reflowing 30 mil SAC305 balls onto Cu, and ENIG coated BGA pads with different amounts of SnPb paste, aging and/or cycling the joints and inspecting the microstructure by cross polarizer microscopy and SEM. We found that the addition of small amounts of Pb had significant effects on solidification during cool-down from reflow, and consequently the initial microstructure. In terms of the varying cycling amplitude study, we note how realistic service conditions are almost never well approximated by cycling with fixed amplitudes. Recent results have demonstrated the consistent breakdown of common damage accumulation rules. In isothermal cycling tests the remaining life, after a step-down in amplitude, was invariably shorter than predicted by such a rule, while a step-up tended to have the opposite effect. The present work offers a mechanistic explanation for this and the basis for a practical approach to the assessment of life under service conditions. Realistic BGA joints were cycled individually in a micromechanical tester, monitoring the solder stiffness and the inelastic energy deposition. Cycling was seen to first cause rapid hardening, followed by leveling off in a 'cyclic saturation' stage and eventually the initiation and growth of a crack until failure. A temporary increase in amplitude during cycling caused a lasting reduction in hardness, and thus enhanced inelastic energy deposition and damage evolution, after the fact. This factor dominates during repeated increases and decreases, eventually shortening the remaining life dramatically

  18. 10 CFR Appendix D1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Clothes Dryers

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Uniform Test Method for Measuring the Energy Consumption... Appendix D1 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Clothes... without heated or unheated forced air circulation to remove moisture from the clothing, remove wrinkles or...

  19. 10 CFR Appendix D2 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Clothes Dryers

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Uniform Test Method for Measuring the Energy Consumption... Appendix D2 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Clothes... forced air circulation to remove moisture from the clothing, remove wrinkles or prevent wrinkling of the...

  20. 10 CFR Appendix D1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Clothes Dryers

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Uniform Test Method for Measuring the Energy Consumption... Appendix D1 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Clothes... without heated or unheated forced air circulation to remove moisture from the clothing, remove wrinkles or...

  1. 10 CFR Appendix C to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Dishwashers

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Preconditioning cycle means any cycle that includes a fill, circulation, and drain to ensure that the water lines... truncated normal cycle without a test load if the dishwasher does not heat water in the normal cycle. 2.6.2... water temperatures encountered in the test cycle. 3.4 Water pressure gauge. The water pressure gauge...

  2. Isolation and genetic characterization of Toxoplasma gondii from the gray wolf Canis lupus

    USDA-ARS?s Scientific Manuscript database

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study feral gray wolf (Canis lupus) from Minnesota were examined for T. gondii infection. Antibodies to T. gondii were detected in 130 (52.4%) of 248 wolves tested by the modified agglutination test...

  3. Forecasting Techniques and Library Circulation Operations: Implications for Management.

    ERIC Educational Resources Information Center

    Ahiakwo, Okechukwu N.

    1988-01-01

    Causal regression and time series models were developed using six years of data for home borrowing, average readership, and books consulted at a university library. The models were tested for efficacy in producing short-term planning and control data. Combined models were tested in establishing evaluation measures. (10 references) (Author/MES)

  4. Design modification for the modular helium reactor for higher temperature operation and reliability studies for nuclear hydrogen production processes

    NASA Astrophysics Data System (ADS)

    Reza, S. M. Mohsin

    Design options have been evaluated for the Modular Helium Reactor (MHR) for higher temperature operation. An alternative configuration for the MHR coolant inlet flow path is developed to reduce the peak vessel temperature (PVT). The coolant inlet path is shifted from the annular path between reactor core barrel and vessel wall through the permanent side reflector (PSR). The number and dimensions of coolant holes are varied to optimize the pressure drop, the inlet velocity, and the percentage of graphite removed from the PSR to create this inlet path. With the removal of ˜10% of the graphite from PSR the PVT is reduced from 541°C to 421°C. A new design for the graphite block core has been evaluated and optimized to reduce the inlet coolant temperature with the aim of further reduction of PVT. The dimensions and number of fuel rods and coolant holes, and the triangular pitch have been changed and optimized. Different packing fractions for the new core design have been used to conserve the number of fuel particles. Thermal properties for the fuel elements are calculated and incorporated into these analyses. The inlet temperature, mass flow and bypass flow are optimized to limit the peak fuel temperature (PFT) within an acceptable range. Using both of these modifications together, the PVT is reduced to ˜350°C while keeping the outlet temperature at 950°C and maintaining the PFT within acceptable limits. The vessel and fuel temperatures during low pressure conduction cooldown and high pressure conduction cooldown transients are found to be well below the design limits. The reliability and availability studies for coupled nuclear hydrogen production processes based on the sulfur iodine thermochemical process and high temperature electrolysis process have been accomplished. The fault tree models for both these processes are developed. Using information obtained on system configuration, component failure probability, component repair time and system operating modes and conditions, the system reliability and availability are assessed. Required redundancies are made to improve system reliability and to optimize the plant design for economic performance. The failure rates and outage factors of both processes are found to be well below the maximum acceptable range.

  5. REVIEW OF PROPOSED METHODOLOGY FOR A RISK- INFORMED RELAXATION TO ASME SECTION XI APPENDIX G

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dickson, Terry L; Kirk, Mark

    2010-01-01

    The current regulations, as set forth by the United States Nuclear Regulatory Commission (NRC), to insure that light-water nuclear reactor pressure vessels (RPVs) maintain their structural integrity when subjected to planned normal reactor startup (heat-up) and shut-down (cool-down) transients are specified in Appendix G to 10 CFR Part 50, which incorporates by reference Appendix G to Section XI of the American Society of Mechanical Engineers (ASME) Code. The technical basis for these regulations are now recognized by the technical community as being conservative and some plants are finding it increasingly difficult to comply with the current regulations. Consequently, the nuclearmore » industry has developed, and submitted to the ASME Code for approval, an alternative risk-informed methodology that reduces the conservatism and is consistent with the methods previously used to develop a risk-informed revision to the regulations for accidental transients such as pressurized thermal shock (PTS). The objective of the alternative methodology is to provide a relaxation to the current regulations which will provide more operational flexibility, particularly for reactor pressure vessels with relatively high irradiation levels and radiation sensitive materials, while continuing to provide reasonable assurance of adequate protection to public health and safety. The NRC and its contractor at Oak Ridge National Laboratory (ORNL) have recently performed an independent review of the industry proposed methodology. The NRC / ORNL review consisted of performing probabilistic fracture mechanics (PFM) analyses for a matrix of cool-down and heat-up rates, permutated over various reactor geometries and characteristics, each at multiple levels of embrittlement, including 60 effective full power years (EFPY) and beyond, for various postulated flaw characterizations. The objective of this review is to quantify the risk of a reactor vessel experiencing non-ductile fracture, and possible subsequent failure, over a wide range of normal transient conditions, when the maximum allowable thermal-hydraulic boundary conditions, derived from both the current ASME code and the industry proposed methodology, are imposed on the inner surface of the reactor vessel. This paper discusses the results of the NRC/ORNL review of the industry proposal including the matrices of PFM analyses, results, insights, and conclusions derived from these analyses.« less

  6. The susceptibility of circulating human influenza viruses to tizoxanide, the active metabolite of nitazoxanide.

    PubMed

    Tilmanis, Danielle; van Baalen, Carel; Oh, Ding Yuan; Rossignol, Jean-Francois; Hurt, Aeron C

    2017-11-01

    Nitazoxanide is a thiazolide compound that was originally developed as an anti-parasitic agent, but has recently been repurposed for the treatment of influenza virus infections. Thought to exert its anti-influenza activity via the inhibition of hemagglutinin maturation and intracellular trafficking in infected cells, the effectiveness of nitazoxanide in treating patients with non-complicated influenza is currently being assessed in phase III clinical trials. Here, we describe the susceptibility of 210 seasonal influenza viruses to tizoxanide, the active circulating metabolite of nitazoxanide. An optimised cell culture-based focus reduction assay was used to determine the susceptibility of A(H1N1)pdm09, A(H3N2), and influenza B viruses circulating in the southern hemisphere from the period March 2014 to August 2016. Tizoxanide showed potent in vitro antiviral activity against all influenza viruses tested, including neuraminidase inhibitor-resistant viruses, allowing the establishment of a baseline level of susceptibility for each subtype. Median EC 50 values (±IQR) of 0.48 μM (0.33-0.71), 0.62 μM (0.56-0.75), 0.66 μM (0.62-0.69), and 0.60 μM (0.51-0.67) were obtained for A(H1N1)pdm09, A(H3N2), B(Victoria lineage), and B(Yamagata lineage) influenza viruses respectively. There was no significant difference in the median baseline tizoxanide susceptibility for each influenza subtype tested. This is the first report on the susceptibility of circulating viruses to tizoxanide. The focus reduction assay format described is sensitive, robust, and less laborious than traditional cell based antiviral assays, making it highly suitable for the surveillance of tizoxanide susceptibility in circulating seasonal influenza viruses. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Adherence and Coagulation Assays in Dabigatran-treated Patients With Atrial Fibrillation

    ClinicalTrials.gov

    2017-09-12

    Atrial Fibrillation; Medication Adherence; Blood Coagulation Tests; Anticoagulants; Circulating, Hemorrhagic Disorder; Drug Effect; Drug Use; Drug Toxicity; Drug Intolerance; Blood Clot; Blood Coagulation Disorder; Laboratory Problem; Bleeding; Thrombosis

  8. Brain natriutetic peptide test

    MedlinePlus

    ... having blood drawn are slight but may include: Excessive bleeding Fainting or feeling lightheaded Hematoma (blood accumulating ... College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation . 2013;128(16):e240- ...

  9. Liquid biopsy in pancreatic cancer: the beginning of a new era

    PubMed Central

    Yadav, Dipesh Kumar; Bai, Xueli; Yadav, Rajesh Kumar; Singh, Alina; Li, Guogang; Ma, Tao; Chen, Wei; Liang, Tingbo

    2018-01-01

    With dismal survival rate pancreatic cancer remains one of the most aggressive and devastating malignancy. Predominantly, due to the absence of a dependable methodology for early identification and limited therapeutic options for advanced disease. However, it takes over 17 years to develop pancreatic cancer from initiation of mutation to metastatic cancer; therefore, if diagnosed early; it may increase overall survival dramatically, thus, providing a window of opportunity for early detection. Recently, genomic expression analysis defined 4 subtypes of pancreatic cancer based on mutated genes. Hence, we need simple and standard, minimally invasive test that can monitor those altered genes or their associated pathways in time for the success of precision medicine, and liquid biopsy seems to be one answer to all these questions. Again, liquid biopsy has an ability to pair with genomic tests. Additionally, liquid biopsy based development of circulating tumor cells derived xenografts, 3D organoids system, real-time monitoring of genetic mutations by circulating tumor DNA and exosome as the targeted drug delivery vehicle holds lots of potential for the treatment and cure of pancreatic cancer. At present, diagnosis of pancreatic cancer is frantically done on the premise of CA19-9 and radiological features only, which doesn't give a picture of genetic mutations and epigenetic alteration involved. In this manner, the current diagnostic paradigm for pancreatic cancer diagnosis experiences low diagnostic accuracy. This review article discusses the current state of liquid biopsy in pancreatic cancer as diagnostic and therapeutic tools and future perspectives of research in the light of circulating tumor cells, circulating tumor DNA and exosomes.

  10. Circulating miR-128 as a potential diagnostic biomarker for glioma.

    PubMed

    Liang, Ruo-Fei; Li, Mao; Yang, Yuan; Wang, Xiang; Mao, Qing; Liu, Yan-Hui

    2017-09-01

    miR-128 in circulation is a promising marker for early diagnosis of glioma. A meta-analysis was performed to evaluate the diagnostic accuracy and clinical value of circulating miR-128 in patients with glioma. A comprehensive literature search for relevant published articles (last search updated on December 29, 2016) was conducted in the Chinese Biomedical Literature Database, PubMed, and Embase. The quality assessment of diagnostic accuracy studies (QUADAS) tool was used to score the quality of the eligible studies. Meta-Disc 1.4 software was used to test for heterogeneity and to perform the meta-analysis. The three studies included in our study enrolled a total of 191 patients with glioma and 73 individuals without tumor. Using a fixed-effect model analysis, the summary assessments revealed that the pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 0.89 (95% CI: 0.84-0.93), 0.90 (95% CI: 0.81-0.96), 8.07 (95% CI: 4.21-15.46), and 0.13 (95% CI: 0.09-0.19), respectively. The diagnostic odds ratio (DOR) of miR-128 was 65.00 (95% CI: 26.90-157.10), indicating that the overall accuracy of the miR-128 test for detecting glioma was high. The value of I 2 was 0.0%, indicating that there was no significant heterogeneity among studies. The present meta-analysis showed that circulating miR-128 might be a promising noninvasive biomarker for diagnosing glioma. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Real-Time RT-PCR Assays for Detection and Genotyping of West Nile Virus Lineages Circulating in Africa.

    PubMed

    Fall, Gamou; Faye, Martin; Weidmann, Manfred; Kaiser, Marco; Dupressoir, Anne; Ndiaye, El Hadj; Ba, Yamar; Diallo, Mawlouth; Faye, Ousmane; Sall, Amadou Alpha

    2016-12-01

    West Nile virus (WNV) is an emerging arbovirus, circulating worldwide between birds and mosquitoes, which impacts human and animal health. Since the mid-1990s, WNV outbreaks have emerged in Europe and America and represent currently the primary cause of encephalitis in the United States. WNV exhibits a great genetic diversity with at least eight different lineages circulating in the world, and four (1, 2, Koutango, and putative new) are present in Africa. These different WNV lineages are not readily differentiated by serology, and thus, rapid molecular tools are required for diagnostic. We developed here real-time RT-PCR assays for detection and genotyping of African WNV lineages. The specificity of the assays was tested using other flaviviruses circulating in Africa. The sensitivity was determined by testing serial 10-fold dilutions of viruses and RNA standards. The assays provided good specificity and sensitivity and the analytical detection limit was 10 copies/reaction. The RT-PCR assays allowed the detection and genotyping of all WNV isolates in culture medium, human serum, and vertebrate tissues, as well as in field and experimental mosquito samples. Comparing the ratios of genome copy number/infectious virion (plaque-forming units), our study finally revealed new insight on the replication of these different WNV lineages in mosquito cells. Our RT-PCR assays are the first ones allowing the genotyping of all WNV African variants, and this may have important applications in surveillance and epidemiology in Africa and also for monitoring of their emergence in Europe and other continents.

  12. Measuring Global Surface Pressures on a Circulation Control Concept Using Pressure Sensitive Paint

    NASA Technical Reports Server (NTRS)

    Watkins, Anthony N.; Lipford, William E.; Leighty, Bradley D.; Goodman, Kyle Z.; Goad, William K.

    2012-01-01

    This report will present the results obtained from the Pressure Sensitive Paint (PSP) technique on a circulation control concept model. This test was conducted at the National Transonic Facility (NTF) at the NASA Langley Research Center. PSP was collected on the upper wing surface while the facility was operating in cryogenic mode at 227 K (-50 oF). The test envelope for the PSP portion included Mach numbers from 0.7 to 0.8 with angle of attack varying between 0 and 8 degrees and a total pressure of approximately 168 kPa (24.4 psi), resulting in a chord Reynolds number of approximately 15 million. While the PSP results did exhibit high levels of noise in certain conditions (where the oxygen content of the flow was very small), some conditions provided good correlation between the PSP and pressure taps, showing the ability of the PSP technique. This work also served as a risk reduction opportunity for future testing in cryogenic conditions at the NTF.

  13. Jet penetration into a riser operated in dense suspension upflow: experimental and model comparisons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shadle, L.J.; Ludlow, C.J.; Spenik, J.L.

    2008-05-13

    Solids tracers were used to characterize the penetration of a gas-solids jet directed toward the center of the 0.3-m diameter, circulating fluidized bed (CFB) riser. The penetration was measured by tracking phosphorescent particles illuminated immediately prior to injection into the riser. Photosensors and piezoelectric detectors were traversed across the radius of the riser at various axial positions to detect the phosphorescent jet material and particles traveling in the radial direction. Local particle velocities were measured at various radial positions, riser heights, and azimuthal angles using an optical fiber probe. Four (4) variables were tested including the jet velocity, solids feedmore » rate into the jet, the riser velocity, and overall CFB circulation rate over 8 distinct test cases with the central, or base case, repeated each time the test series was conducted. In addition to the experimental measurements made, the entire riser with a side feed jet of solids was simulated using the Eulerian-Eulerian computer model MFIX.« less

  14. Fibromax-based nonalcoholic fatty liver disease in chronic obstructive pulmonary disease patients with obstructive sleep apnea: Methodological considerations

    PubMed Central

    Monneret, Denis

    2017-01-01

    The relationship between nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) has been well demonstrated, but remains to be evidenced in chronic obstructive pulmonary disease (COPD). Recently, Viglino et al. (Eur Respir J, 2017) attempted to determine the prevalence of liver fibrosis, steatosis and nonalcoholic steatohepatitis (NASH) in COPD patients, some of whom had OSA, basing the NAFLD diagnostic on three circulating biomarker-based liver scores: the FibroTest, SteatoTest and NashTest, from the Fibromax® panel. Among the main findings, the absence of OSA treatment emerged as independently associated with liver fibrosis and steatosis, when compared to effective treatment. However, besides the low number of treated patients, no polysomnographic respiratory data was provided, making it difficult to differentiate the impact of OSA from that of COPD in NAFLD prevalence. Furthermore, NAFLD diagnosis relied exclusively on circulating biomarker-based liver scores, without histological, imagery or other liver exploratory methods. Therefore, in this article, some methodological points are reminded and discussed, including the choice of OSA measurements, and the significance of ActiTest and AshTest scores from Fibromax® in this pathophysiological context. PMID:29225775

  15. A Blood-based Test for the Detection of ROS1 and RET Fusion Transcripts from Circulating Ribonucleic Acid Using Digital Polymerase Chain Reaction

    PubMed Central

    Mellert, Hestia S.; Alexander, Kristin E.; Jackson, Leisa P.; Pestano, Gary A.

    2018-01-01

    We have developed novel methods for the isolation and characterization of tumor-derived circulating ribonucleic acid (cRNA) for blood-based liquid biopsy. Robust detection of cRNA recovered from blood represents a solution to a critical unmet need in clinical diagnostics. The test begins with the collection of whole blood into blood collection tubes containing preservatives that stabilize cRNA. Cell-free, exosomal, and platelet-associated RNA is isolated from plasma in this test system. The cRNA is reverse transcribed to complementary DNA (cDNA) and amplified using digital polymerase chain reaction (dPCR). Samples are evaluated for both the target biomarker as well as a control gene. Test validation included limit of detection, accuracy, and robustness studies with analytic samples. The method developed as a result of these studies reproducibly detect multiple fusion variants for ROS1 (C-Ros proto-oncogene 1; 8 variants) and RET (rearranged during transfection proto-oncogene; 8 variants). The sample processing workflow has been optimized so that test results can consistently be generated within 72 hours of sample receipt. PMID:29683453

  16. Seroprevalence of Toscana virus infection in Tunisia.

    PubMed

    Fezaa, Ons; Bahri, Olfa; Alaya Bouafif, Nissaf Ben; Triki, Henda; Bouattour, Ali

    2013-12-01

    The main objective of this study was to assess the prevalence of IgG antibodies against Toscana virus (TOSV) by an ELISA test and to determine the extent of its circulation in Tunisia. An indirect ELISA test was performed to detect anti-TOSV IgG. The results were compared to those of an indirect fluorescent antibody (IFA) test. The survey tested 494 healthy people from various regions of Tunisia by ELISA for anti-TOSV IgG; 47 people (9.5%) were found to be positive. Seroprevalence varied by bioclimatic region and gender. Two hundred and twelve samples, randomly chosen from the same selected population and tested with ELISA, were retested using an IFA for IgG antibodies. An 85% concordance between the IFA and ELISA was obtained (kappa=0.650). These serological data confirm the circulation of TOSV in different bioclimatic zones in Tunisia where the vector sand flies are found. The detection of IgG against TOSV suggests that the diagnosis of TOSV infection is often neglected, as this virus often causes asymptomatic infections, with only a few patients developing severe illnesses involving neurological manifestations. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  17. Circulating vaccine-derived polioviruses: current state of knowledge.

    PubMed Central

    Kew, Olen M.; Wright, Peter F.; Agol, Vadim I.; Delpeyroux, Francis; Shimizu, Hiroyuki; Nathanson, Neal; Pallansch, Mark A.

    2004-01-01

    Within the past 4 years, poliomyelitis outbreaks associated with circulating vaccine-derived polioviruses (cVDPVs) have occurred in Hispaniola (2000-01), the Philippines (2001), and Madagascar (2001-02). Retrospective studies have also detected the circulation of endemic cVDPV in Egypt (1988-93) and the likely localized spread of oral poliovirus vaccine (OPV)-derived virus in Belarus (1965-66). Gaps in OPV coverage and the previous eradication of the corresponding serotype of indigenous wild poliovirus were the critical risk factors for all cVDPV outbreaks. The cVDPV outbreaks were stopped by mass immunization campaigns using OPV. To increase sensitivity for detecting vaccine-derived polioviruses (VDPVs), in 2001 the Global Polio Laboratory Network implemented additional testing requirements for all poliovirus isolates under investigation. This approach quickly led to the recognition of the Philippines and Madagascar cVDPV outbreaks, but of no other current outbreaks. The potential risk of cVDPV emergence has increased dramatically in recent years as wild poliovirus circulation has ceased in most of the world. The risk appears highest for the type 2 OPV strain because of its greater tendency to spread to contacts. The emergence of cVDPVs underscores the critical importance of eliminating the last pockets of wild poliovirus circulation, maintaining universally high levels of polio vaccine coverage, stopping OPV use as soon as it is safely possible to do so, and continuing sensitive poliovirus surveillance into the foreseeable future. Particular attention must be given to areas where the risks for wild poliovirus circulation have been highest, and where the highest rates of polio vaccine coverage must be maintained to suppress cVDPV emergence. PMID:15106296

  18. Combination of TOPEX/POSEIDON Data with a Hydrographic Inversion for Determination of the Oceanic General Circulation and its Relation to Geoid Accuracy

    NASA Technical Reports Server (NTRS)

    Ganachaud, Alexandre; Wunsch, Carl; Kim, Myung-Chan; Tapley, Byron

    1997-01-01

    A global estimate of the absolute oceanic general circulation from a geostrophic inversion of in situ hydrographic data is tested against and then combined with an estimate obtained from TOPEX/POSEIDON altimetric data and a geoid model computed using the JGM-3 gravity-field solution. Within the quantitative uncertainties of both the hydrographic inversion and the geoid estimate, the two estimates derived by very different methods are consistent. When the in situ inversion is combined with the altimetry/geoid scheme using a recursive inverse procedure, a new solution, fully consistent with both hydrography and altimetry, is found. There is, however, little reduction in the uncertainties of the calculated ocean circulation and its mass and heat fluxes because the best available geoid estimate remains noisy relative to the purely oceanographic inferences. The conclusion drawn from this is that the comparatively large errors present in the existing geoid models now limit the ability of satellite altimeter data to improve directly the general ocean circulation models derived from in situ measurements. Because improvements in the geoid could be realized through a dedicated spaceborne gravity recovery mission, the impact of hypothetical much better, future geoid estimates on the circulation uncertainty is also quantified, showing significant hypothetical reductions in the uncertainties of oceanic transport calculations. Full ocean general circulation models could better exploit both existing oceanographic data and future gravity-mission data, but their present use is severely limited by the inability to quantify their error budgets.

  19. The vertical distribution of nutrients and oxygen 18 in the upper Arctic Ocean

    NASA Astrophysics Data System (ADS)

    BjöRk, GöRan

    1990-09-01

    The observed vertical nutrient distribution including a maximum at about 100 m depth in the Arctic Ocean is investigated using a one-dimensional time-dependent circulation model together with a simple biological model. The circulation model includes a shelf-forced circulation. This is thought to take place in a box from which the outflow is specified regarding temperature and volume flux at different salinities. It has earlier been shown that the circulation model is able to reproduce the observed mean salinity and temperature stratification in the Arctic Ocean. Before introducing nutrients in the model a test is performed using the conservative tracer δ18 (18O/16O ratio) as one extra state variable in order to verify the circulation model. It is shown that the field measurements can be simulated. The result is, however, rather sensitive to the tracer concentration in the Bering Strait inflow. The nutrients nitrate, phosphate, and silicate are then treated by coupling a simple biological model to the circulation model. The biological model describes some overall effects of production, sinking, and decomposition of organic matter. First a standard case of the biological model is presented. This is followed by some modified cases. It is shown that the observed nutrient distribution including the maximum can be generated. The available nutrient data from the Arctic Ocean are not sufficient to decide which among the cases is the most likely to occur. One case is, however, chosen as the best case. A nutrient budget and estimates of the magnitudes of the new production are presented for this case.

  20. Erythropoietin induces bone marrow and plasma fibroblast growth factor 23 during acute kidney injury.

    PubMed

    Toro, Luis; Barrientos, Víctor; León, Pablo; Rojas, Macarena; Gonzalez, Magdalena; González-Ibáñez, Alvaro; Illanes, Sebastián; Sugikawa, Keigo; Abarzúa, Néstor; Bascuñán, César; Arcos, Katherine; Fuentealba, Carlos; Tong, Ana María; Elorza, Alvaro A; Pinto, María Eugenia; Alzamora, Rodrigo; Romero, Carlos; Michea, Luis

    2018-05-01

    It is accepted that osteoblasts/osteocytes are the major source for circulating fibroblast growth factor 23 (FGF23). However, erythropoietic cells of bone marrow also express FGF23. The modulation of FGF23 expression in bone marrow and potential contribution to circulating FGF23 has not been well studied. Moreover, recent studies show that plasma FGF23 may increase early during acute kidney injury (AKI). Erythropoietin, a kidney-derived hormone that targets erythropoietic cells, increases in AKI. Here we tested whether an acute increase of plasma erythropoietin induces FGF23 expression in erythropoietic cells of bone marrow thereby contributing to the increase of circulating FGF23 in AKI. We found that erythroid progenitor cells of bone marrow express FGF23. Erythropoietin increased FGF23 expression in vivo and in bone marrow cell cultures via the homodimeric erythropoietin receptor. In experimental AKI secondary to hemorrhagic shock or sepsis in rodents, there was a rapid increase of plasma erythropoietin, and an induction of bone marrow FGF23 expression together with a rapid increase of circulating FGF23. Blockade of the erythropoietin receptor fully prevented the induction of bone marrow FGF23 and partially suppressed the increase of circulating FGF23. Finally, there was an early increase of both circulating FGF23 and erythropoietin in a cohort of patients with severe sepsis who developed AKI within 48 hours of admission. Thus, increases in plasma erythropoietin and erythropoietin receptor activation are mechanisms implicated in the increase of plasma FGF23 in AKI. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

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