VPS Process for Copper Components in Thrust Chamber Assemblies

NASA Technical Reports Server (NTRS)

Elam, Sandra; Holmes, Richard; Hickman, Robert; McKechnie, Tim; Thom, George

2005-01-01

For several years, NASA's Marshall Space Flight Center (MSFC) has been working with Plasma Processes, Inc., (PPI) to fabricate thrust chamber liners with GRCop-84. Using the vacuum plasma spray (VPS) process, chamber liners of a variety of shapes and sizes have been created. Each has been formed as a functional gradient material (FGM) that creates a unique protective layer of NiCrAlY on the GRCop-84 liner s hot wall surface. Hot-fire testing was successfully conducted on a subscale unit to demonstrate the liner's durability and performance. Similar VPS technology has also been applied to create functional gradient coatings (FGC) on copper injector faceplates. Protective layers of NiCrAlY and zirconia were applied to both coaxial and impinging faceplate designs. Hot-fire testing is planned for these coated injectors in April 2005. The resulting material systems for both copper alloy components allows them to operate at higher temperatures with improved durability and operating margins.

40 CFR 53.62 - Test procedure: Full wind tunnel test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... accuracy of 5 percent or better (e.g., hot-wire anemometry). For the wind speeds specified in table F-2 of... candidate sampler as a function of aerodynamic particle diameter (Dae) on semi-logarithmic graph paper where...

40 CFR 53.62 - Test procedure: Full wind tunnel test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... accuracy of 5 percent or better (e.g., hot-wire anemometry). For the wind speeds specified in table F-2 of... candidate sampler as a function of aerodynamic particle diameter (Dae) on semi-logarithmic graph paper where...

40 CFR 53.62 - Test procedure: Full wind tunnel test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... accuracy of 5 percent or better (e.g., hot-wire anemometry). For the wind speeds specified in table F-2 of... candidate sampler as a function of aerodynamic particle diameter (Dae) on semi-logarithmic graph paper where...

40 CFR 53.62 - Test procedure: Full wind tunnel test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... accuracy of 5 percent or better (e.g., hot-wire anemometry). For the wind speeds specified in table F-2 of... candidate sampler as a function of aerodynamic particle diameter (Dae) on semi-logarithmic graph paper where...

The Effects of Simulated Wildland Firefighting Tasks on Core Temperature and Cognitive Function under Very Hot Conditions.

PubMed

Williams-Bell, F Michael; Aisbett, Brad; Murphy, Bernadette A; Larsen, Brianna

2017-01-01

Background: The severity of wildland fires is increasing due to continually hotter and drier summers. Firefighters are required to make life altering decisions on the fireground, which requires analytical thinking, problem solving, and situational awareness. This study aimed to determine the effects of very hot (45°C; HOT) conditions on cognitive function following periods of simulated wildfire suppression work when compared to a temperate environment (18°C; CON). Methods: Ten male volunteer firefighters intermittently performed a simulated fireground task for 3 h in both the CON and HOT environments, with cognitive function tests (paired associates learning and spatial span) assessed at baseline (cog 1) and during the final 20-min of each hour (cog 2, 3, and 4). Reaction time was also assessed at cog 1 and cog 4. Pre- and post- body mass were recorded, and core and skin temperature were measured continuously throughout the protocol. Results: There were no differences between the CON and HOT trials for any of the cognitive assessments, regardless of complexity. While core temperature reached 38.7°C in the HOT (compared to only 37.5°C in the CON; p < 0.01), core temperature declined during the cognitive assessments in both conditions (at a rate of -0.15 ± 0.20°C·hr -1 and -0.63 ± 0.12°C·hr -1 in the HOT and CON trial respectively). Firefighters also maintained their pre-exercise body mass in both conditions, indicating euhydration. Conclusions: It is likely that this maintenance of euhydration and the relative drop in core temperature experienced between physical work bouts was responsible for the preservation of firefighters' cognitive function in the present study.

The Effects of Simulated Wildland Firefighting Tasks on Core Temperature and Cognitive Function under Very Hot Conditions

PubMed Central

Williams-Bell, F. Michael; Aisbett, Brad; Murphy, Bernadette A.; Larsen, Brianna

2017-01-01

Background: The severity of wildland fires is increasing due to continually hotter and drier summers. Firefighters are required to make life altering decisions on the fireground, which requires analytical thinking, problem solving, and situational awareness. This study aimed to determine the effects of very hot (45°C; HOT) conditions on cognitive function following periods of simulated wildfire suppression work when compared to a temperate environment (18°C; CON). Methods: Ten male volunteer firefighters intermittently performed a simulated fireground task for 3 h in both the CON and HOT environments, with cognitive function tests (paired associates learning and spatial span) assessed at baseline (cog 1) and during the final 20-min of each hour (cog 2, 3, and 4). Reaction time was also assessed at cog 1 and cog 4. Pre- and post- body mass were recorded, and core and skin temperature were measured continuously throughout the protocol. Results: There were no differences between the CON and HOT trials for any of the cognitive assessments, regardless of complexity. While core temperature reached 38.7°C in the HOT (compared to only 37.5°C in the CON; p < 0.01), core temperature declined during the cognitive assessments in both conditions (at a rate of −0.15 ± 0.20°C·hr−1 and −0.63 ± 0.12°C·hr−1 in the HOT and CON trial respectively). Firefighters also maintained their pre-exercise body mass in both conditions, indicating euhydration. Conclusions: It is likely that this maintenance of euhydration and the relative drop in core temperature experienced between physical work bouts was responsible for the preservation of firefighters' cognitive function in the present study. PMID:29114230

Dose accuracy of a durable insulin pen with memory function, before and after simulated lifetime use and under stress conditions.

PubMed

Xue, Ligang; Mikkelsen, Kristian Handberg

2013-03-01

The objective of this study was to assess the dose accuracy of NovoPen® 5 in delivering low, medium and high doses of insulin before and after simulated lifetime use. A secondary objective was to evaluate the durability of the pen and its memory function under various stress conditions designed to simulate conditions that may be encountered in everyday use of an insulin pen. All testing was conducted according to International Organization for Standardization guideline 11608-1, 2000 for pen injectors. Dose accuracy was measured for the delivery of 1 unit (U) (10 mg), 30 U (300 mg) and 60 U (600 mg) test medium in standard, cool and hot conditions and before and after simulated lifetime use. Dose accuracy was also tested after preconditioning in dry heat storage; cold storage; damp cyclical heat; shock, bump and vibration; free fall and after electrostatic charge and radiated field test. Memory function was tested under all temperature and physical conditions. NovoPen 5 maintained dosing accuracy and memory function at minimum, medium and maximum doses in standard, cool and hot conditions, stress tests and simulated lifetime use. The pens remained intact and retained dosing accuracy and a working memory function at all doses after exposure to variations in temperature and after physical challenge. NovoPen 5 was accurate at all doses tested and under various functionality tests. Its durable design ensured that the dose accuracy and memory function were retained under conditions of stress likely to be encountered in everyday use.

Booster Separation Motor (BSM) Test Fire

NASA Technical Reports Server (NTRS)

2007-01-01

This photograph depicts a hot fire test of the Shuttle Booster Separation Motor (BSM) at the Marshall Space Flight Center (MSFC) test stand 116. The objective of the test was to test the aft heat seal in flight configuration. The function of the motor is to separate the Shuttle vehicle from the boosters that carry it into space.

Hot and Cool Executive Functions in Children with Attention-Deficit/Hyperactivity Disorder and Comorbid Oppositional Defiant Disorder.

PubMed

Antonini, Tanya N; Becker, Stephen P; Tamm, Leanne; Epstein, Jeffery N

2015-09-01

While neuropsychological deficits in both "hot" and "cool" executive functions (EFs) have been documented among individuals with attention-deficit/hyperactivity disorder (ADHD), these EF deficits are not universal across all individuals with this diagnosis. One potential moderator of executive dysfunction may be the presence of comorbid oppositional defiant disorder (ODD). This study examined the association between "hot" and "cool" EFs and comorbid ODD in children with ADHD. Thirty-three children with ADHD and comorbid ODD (ADHD+ODD), 67 with ADHD without ODD (ADHD-ODD), and 30 typically developing controls participated. Children were 7-12 years of age. "Cool" EFs were assessed with a spatial span task and a card sorting test. "Hot" EFs were assessed using a delay discounting task and a gambling task. ADHD-ODD and ADHD+ODD groups performed more poorly on "cool" EF tasks than controls, but did not differ from each other. Furthermore, the number of ADHD symptoms, but not ODD symptoms, was associated with "cool" EF scores. The three groups did not differ on "hot" EF tasks and the number of ADHD or ODD symptoms was unrelated to "hot" EF scores. In sum, children with ADHD presented with "cool" EF deficits which appear to be unrelated to ODD comorbidity. However, "hot" EF deficits were not present among children with ADHD, irrespective of comorbid ODD status.

Amorphous-silicon module hot-spot testing

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.

1985-01-01

Hot spot heating occurs when cell short-circuit current is lower than string operating current. Amorphous cell hot spot are tested to develop the techniques required for performing reverse bias testing of amorphous cells. Also, to quantify the response of amorphous cells to reverse biasing. Guidelines are developed from testing for reducing hot spot susceptibility of amorphous modules and to develop a qualification test for hot spot testing of amorphous modules. It is concluded that amorphous cells undergo hot spot heating similarly to crystalline cells. Comparison of results obtained with submodules versus actual modules indicate heating levels lower in actual modules. Module design must address hot spot testing and hot spot qualification test conducted on modules showed no instabilities and minor cell erosion.

Advanced Vacuum Plasma Spray (VPS) for a Robust, Longlife and Safe Space Shuttle Main Engine (SSME)

NASA Technical Reports Server (NTRS)

Holmes, Richard R.; Elam, Sandra K.; McKechnie, Timothy N.; Power, Christopher A.

2010-01-01

In 1984, the Vacuum Plasma Spray Lab was built at NASA/Marshall Space Flight Center for applying durable, protective coatings to turbine blades for the space shuttle main engine (SSME) high pressure fuel turbopump. Existing turbine blades were cracking and breaking off after five hot fire tests while VPS coated turbine blades showed no wear or cracking after 40 hot fire tests. Following that, a major manufacturing problem of copper coatings peeling off the SSME Titanium Main Fuel Valve Housing was corrected with a tenacious VPS copper coating. A patented VPS process utilizing Functional Gradient Material (FGM) application was developed to build ceramic lined metallic cartridges for space furnace experiments, safely containing gallium arsenide at 1260 degrees centigrade. The VPS/FGM process was then translated to build robust, long life, liquid rocket combustion chambers for the space shuttle main engine. A 5K (5,000 Lb. thrust) thruster with the VPS/FGM protective coating experienced 220 hot firing tests in pristine condition with no wear compared to the SSME which showed blanching (surface pulverization) and cooling channel cracks in less than 30 of the same hot firing tests. After 35 of the hot firing tests, the injector face plates disintegrated. The VPS/FGM process was then applied to spraying protective thermal barrier coatings on the face plates which showed 50% cooler operating temperature, with no wear after 50 hot fire tests. Cooling channels were closed out in two weeks, compared to one year for the SSME. Working up the TRL (Technology Readiness Level) to establish the VPS/FGM process as viable technology, a 40K thruster was built and is currently being tested. Proposed is to build a J-2X size liquid rocket engine as the final step in establishing the VPS/FGM process TRL for space flight.

Robust Low Cost Liquid Rocket Combustion Chamber by Advanced Vacuum Plasma Process

NASA Technical Reports Server (NTRS)

Holmes, Richard; Elam, Sandra; Ellis, David L.; McKechnie, Timothy; Hickman, Robert; Rose, M. Franklin (Technical Monitor)

2001-01-01

Next-generation, regeneratively cooled rocket engines will require materials that can withstand high temperatures while retaining high thermal conductivity. Fabrication techniques must be cost efficient so that engine components can be manufactured within the constraints of shrinking budgets. Three technologies have been combined to produce an advanced liquid rocket engine combustion chamber at NASA-Marshall Space Flight Center (MSFC) using relatively low-cost, vacuum-plasma-spray (VPS) techniques. Copper alloy NARloy-Z was replaced with a new high performance Cu-8Cr-4Nb alloy developed by NASA-Glenn Research Center (GRC), which possesses excellent high-temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability. Functional gradient technology, developed building composite cartridges for space furnaces was incorporated to add oxidation resistant and thermal barrier coatings as an integral part of the hot wall of the liner during the VPS process. NiCrAlY, utilized to produce durable protective coating for the space shuttle high pressure fuel turbopump (BPFTP) turbine blades, was used as the functional gradient material coating (FGM). The FGM not only serves as a protection from oxidation or blanching, the main cause of engine failure, but also serves as a thermal barrier because of its lower thermal conductivity, reducing the temperature of the combustion liner 200 F, from 1000 F to 800 F producing longer life. The objective of this program was to develop and demonstrate the technology to fabricate high-performance, robust, inexpensive combustion chambers for advanced propulsion systems (such as Lockheed-Martin's VentureStar and NASA's Reusable Launch Vehicle, RLV) using the low-cost VPS process. VPS formed combustion chamber test articles have been formed with the FGM hot wall built in and hot fire tested, demonstrating for the first time a coating that will remain intact through the hot firing test, and with no apparent wear. Material physical properties and the hot firing tests are reviewed.

Techniques for hot structures testing

NASA Technical Reports Server (NTRS)

Deangelis, V. Michael; Fields, Roger A.

1990-01-01

Hot structures testing have been going on since the early 1960's beginning with the Mach 6, X-15 airplane. Early hot structures test programs at NASA-Ames-Dryden focused on operational testing required to support the X-15 flight test program, and early hot structures research projects focused on developing lab test techniques to simulate flight thermal profiles. More recent efforts involved numerous large and small hot structures test programs that served to develop test methods and measurement techniques to provide data that promoted the correlation of test data with results from analytical codes. In Nov. 1988 a workshop was sponsored that focused on the correlation of hot structures test data with analysis. Limited material is drawn from the workshop and a more formal documentation is provided of topics that focus on hot structures test techniques used at NASA-Ames-Dryden. Topics covered include the data acquisition and control of testing, the quartz lamp heater systems, current strain and temperature sensors, and hot structures test techniques used to simulate the flight thermal environment in the lab.

The Influence of Non-Nociceptive Factors on Hot Plate Latency in Rats

PubMed Central

Gunn, Amanda; Bobeck, Erin N.; Weber, Ceri; Morgan, Michael M.

2010-01-01

The hot plate is a widely used test to assess nociception. The effect of non-nociceptive factors (weight, sex, activity, habituation, and repeated testing) on hot plate latency was examined. Comparison of body weight and hot plate latency revealed a small but significant inverse correlation (light rats had longer latencies). Habituating rats to the test room for 1 hr prior to testing did not decrease hot plate latency except for female rats tested on Days 2 - 4. Hot plate latency decreased with repeated daily testing, but this was not caused by a decrease in locomotor activity or learning to respond. Activity on the hot plate was consistent across all four trials, and prior exposure to a room temperature plate caused a similar decrease in latency as rats tested repeatedly on the hot plate. Despite this decrease in baseline hot plate latency, there was no difference in morphine antinociceptive potency. The present study shows that weight, habituation to the test room, and repeated testing can alter baseline hot plate latency, but these effects are small and have relatively little impact on morphine antinociception. PMID:20797920

Computational identification of binding energy hot spots in protein-RNA complexes using an ensemble approach.

PubMed

Pan, Yuliang; Wang, Zixiang; Zhan, Weihua; Deng, Lei

2018-05-01

Identifying RNA-binding residues, especially energetically favored hot spots, can provide valuable clues for understanding the mechanisms and functional importance of protein-RNA interactions. Yet, limited availability of experimentally recognized energy hot spots in protein-RNA crystal structures leads to the difficulties in developing empirical identification approaches. Computational prediction of RNA-binding hot spot residues is still in its infant stage. Here, we describe a computational method, PrabHot (Prediction of protein-RNA binding hot spots), that can effectively detect hot spot residues on protein-RNA binding interfaces using an ensemble of conceptually different machine learning classifiers. Residue interaction network features and new solvent exposure characteristics are combined together and selected for classification with the Boruta algorithm. In particular, two new reference datasets (benchmark and independent) have been generated containing 107 hot spots from 47 known protein-RNA complex structures. In 10-fold cross-validation on the training dataset, PrabHot achieves promising performances with an AUC score of 0.86 and a sensitivity of 0.78, which are significantly better than that of the pioneer RNA-binding hot spot prediction method HotSPRing. We also demonstrate the capability of our proposed method on the independent test dataset and gain a competitive advantage as a result. The PrabHot webserver is freely available at http://denglab.org/PrabHot/. leideng@csu.edu.cn. Supplementary data are available at Bioinformatics online.

Hot Deformation Behavior and Dynamic Recrystallization of Medium Carbon LZ50 Steel

NASA Astrophysics Data System (ADS)

Du, Shiwen; Chen, Shuangmei; Song, Jianjun; Li, Yongtang

2017-03-01

Hot deformation and dynamic recrystallization behaviors of a medium carbon steel LZ50 were systematically investigated in the temperature range from 1143 K to 1443 K (870 °C to 1170 °C) at strain rates from 0.05 to 3s-1 using a Gleeble-3500 thermo-simulation machine. The flow stress constitutive equation for hot deformation of this steel was developed with the two-stage Laasraoui equation. The activation energy of the tested steel was 304.27 KJ/mol, which was in reasonable agreement with those reported previously. The flow stress of this steel in hot deformation was mainly controlled by dislocation climb during their intragranular motion. The effect of Zener-Hollomon parameter on the characteristic points of the flow curves was studied, and the dependence of critical strain on peak strain obeyed a linear equation. Dynamic recrystallization was the most important softening mechanism for the tested steel during hot deformation. Kinetic equation of this steel was also established based on the flow stress. The austenite grain size of complete dynamic recrystallization was a power law function of Zener-Hollomon parameter with an exponent of -0.2956. Moreover, the microstructures induced under different deformation conditions were analyzed.

Cold Test Operation of the German VEK Vitrification Plant

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

Fleisch, J.; Schwaab, E.; Weishaupt, M.

2008-07-01

In 2007 the German High-Level Liquid Waste (HLLW) Vitrification plant VEK (Verglasungseinrichtung Karlsruhe) has passed a three months integral cold test operation as final step before entering the hot phase. The overall performance of the vitrification process equipment with a liquid-fed ceramic glass melter as main component proved to be completely in line with the requirements of the regulatory body. The retention efficiency of main radioactive-bearing elements across melter and wet off-gas treatment system exceeded the design values distinctly. The strategy to produce a specified waste glass could be successfully demonstrated. The results of the cold test operation allow enteringmore » the next step of hot commissioning, i.e. processing of approximately 2 m{sup 3} of diluted HLLW. In summary: An important step of the VEK vitrification plant towards hot operation has been the performance of the cold test operation from April to July 2007. This first integral operation was carried out under boundary conditions and rules established for radioactive operation. Operation and process control were carried out following the procedure as documented in the licensed operational manuals. The function of the process technology and the safe operation could be demonstrated. No severe problems were encountered. Based on the positive results of the cold test, application of the license for hot operation has been initiated and is expected in the near future. (authors)« less

The influence of non-nociceptive factors on hot-plate latency in rats.

PubMed

Gunn, Amanda; Bobeck, Erin N; Weber, Ceri; Morgan, Michael M

2011-02-01

The hot plate is a widely used test to assess nociception. The effect of non-nociceptive factors (weight, sex, activity, habituation, and repeated testing) on hot-plate latency was examined. Comparison of body weight and hot-plate latency revealed a small but significant inverse correlation (light rats had longer latencies). Habituating rats to the test room for 1 hour prior to testing did not decrease hot-plate latency except for female rats tested on days 2 to 4. Hot-plate latency decreased with repeated daily testing, but this was not caused by a decrease in locomotor activity or learning to respond. Activity on the hot plate was consistent across all 4 trials, and prior exposure to a room-temperature plate caused a similar decrease in latency as rats tested repeatedly on the hot plate. Despite this decrease in baseline hot-plate latency, there was no difference in morphine antinociceptive potency. The present study shows that weight, habituation to the test room, and repeated testing can alter baseline hot-plate latency, but these effects are small and have relatively little impact on morphine antinociception. This manuscript shows that non-nociceptive factors such as body weight, habituation, and repeated testing can alter hot-plate latency, but these factors do not alter morphine potency. In sum, the hot-plate test is an easy to use and reliable method to assess supraspinally organized nociceptive responses. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

Thermal-Mechanical Testing of Hypersonic Vehicle Structures

NASA Technical Reports Server (NTRS)

Hudson, Larry; Stephens, Craig

2007-01-01

A viewgraph presentation describing thermal-mechanical tests on the structures of hypersonic vehicles is shown. The topics include: 1) U.S. Laboratories for Hot Structures Testing; 2) NASA Dryden Flight Loads Laboratory; 3) Hot Structures Test Programs; 4) Typical Sequence for Hot Structures Testing; 5) Current Hot Structures Testing; and 6) Concluding Remarks.

Voltage verification unit

DOEpatents

Martin, Edward J [Virginia Beach, VA

2008-01-15

A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

Seasonal distribution of net primary production by functional groups in Chihuahuan Desert, and the role of seasonal precipitation

USDA-ARS?s Scientific Manuscript database

In hot deserts, precipitation is the principal driver for net primary production.  This study tested two hypotheses regarding aboveground net primary production (ANPP) and the effects of precipitation on ANPP in the Chihuahuan Desert, with emphasis on differences among seasons and among functional g...

40 CFR 86.138-96 - Hot soak test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Hot soak test. 86.138-96 Section 86...-Duty Vehicles; Test Procedures § 86.138-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately following...

40 CFR 86.138-96 - Hot soak test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Hot soak test. 86.138-96 Section 86...-Duty Vehicles; Test Procedures § 86.138-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately following...

40 CFR 86.138-96 - Hot soak test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Hot soak test. 86.138-96 Section 86...-Duty Vehicles; Test Procedures § 86.138-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately following...

40 CFR 86.138-96 - Hot soak test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Hot soak test. 86.138-96 Section 86...-Duty Vehicles; Test Procedures § 86.138-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately following...

40 CFR 86.138-96 - Hot soak test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hot soak test. 86.138-96 Section 86...-Duty Vehicles; Test Procedures § 86.138-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately following...

CFD assessment of the pollutant environment from RD-170 propulsion system testing

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Mcconnaughey, Paul; Warsi, Saif; Chen, Yen-Sen

1995-01-01

Computational Fluid Dynamics (CFD) technology has been used to assess the exhaust plume pollutant environment of the RD-170 engine hot-firing on the F1 Test Stand at Marshall Space Flight Center. Researchers know that rocket engine hot-firing has the potential for forming thermal nitric oxides (NO(x)), as well as producing carbon monoxide (CO) when hydrocarbon fuels are used. Because of the complicated physics involved, however, little attempt has been made to predict the pollutant emissions from ground-based engine testing, except for simplified methods which can grossly underpredict and/or overpredict the pollutant formations in a test environment. The objective of this work, therefore, has been to develop a technology using CFD to describe the underlying pollutant emission physics from ground-based rocket engine testing. This resultant technology is based on a three-dimensional (3D), viscous flow, pressure-based CFD formulation, where wet CO and thermal NO finite-rate chemistry mechanisms are solved with a Penalty Function method. A nominal hot-firing of a RD-170 engine on the F1 stand has been computed. Pertinent test stand flow physics such as the multiple-nozzle clustered engine plume interaction, air aspiration from base and aspirator, plume mixing with entrained air that resulted in contaminant dilution and afterburning, counter-afterburning due to flame bucket water-quenching, plume impingement on the flame bucket, and restricted multiple-plume expansion and turning have been captured. The predicted total emission rates compared reasonably well with those of the existing hydrocarbon engine hot-firing test data.

Effect of rolling on the high temperature tensile and stress-rupture properties of tungsten fiber-superalloy composites

NASA Technical Reports Server (NTRS)

Petrasek, D. W.

1974-01-01

An investigation was conducted to determine the effects of mechanical working on the 1093 C (2000 F) tensile and stress-rupture strength of tungsten alloy/superalloy composites. Hot pressed composites containing either conventional tungsten lamp filament wire or tungsten-1% ThO2 wire and a nickel base alloy matrix were hot rolled at 1093 C (2000 F). The hot pressed and rolled composite specimens were then tested in tension and stress-rupture at 1093 C (2000 F). Rolling decreased the degree of fiber-matrix reaction as a function of time of exposure at 1093 C (2000 F). The stress-rupture properties of the rolled composites were superior to hot pressed composites containing equivalent diameter fibers. Rolling did not appreciably affect the 1093 C (2000 F) ultimate tensile strength of the composites.

40 CFR 1066.965 - Hot soak test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Hot soak test. 1066.965 Section 1066.965 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... Procedures for Motor Vehicles § 1066.965 Hot soak test. Test vehicles for hot soak emissions as described in...

Evaluating Effects of Heat Stress on Cognitive Function among Workers in a Hot Industry.

PubMed

Mazloumi, Adel; Golbabaei, Farideh; Mahmood Khani, Somayeh; Kazemi, Zeinab; Hosseini, Mostafa; Abbasinia, Marzieh; Farhang Dehghan, Somayeh

2014-01-01

Heat stress, as one of the most common occupational health problems, can impair operators' cognitive processes. The aim of this study was to evaluate the impact of thermal stress on cognitive function among workers in a hot industry. In this cross-sectional study conducted in Malibel Saipa Company in 2013, workers were assigned into two groups: one group were exposed to heat stress (n=35), working in casting unit and the other group working in machining unit (n=35) with a normal air conditioning. Wet Bulb Globe Temperature was measured at three heights of ankle, abdomen, and head. In order to evaluate the effects of heat stress on attention and reaction time, Stroop tests 1, 2, and 3 were conducted before starting the work and during the work. A significant positive correlation was observed between WBGT and test duration (P=0.01) and reaction time of Stroop test 3 (P=0.047), and between number of errors in Stroop tests 1, 2, and 3, during the work (P= 0.001). Moreover, Stroop test 3 showed a significant higher score for both test duration and reaction time of workers in case group. RESULTS of the present study, conducted in a real work environment, confirmed the impairment of cognitive functions, including selective attention and reaction time, under heat stress conditions.

[Meteoadaptogenic properties of peptide drugs in healthy volunteers].

PubMed

Shabanov, P D; Ganapol'skiĭ, V P; Aleksandrov, P V

2007-01-01

The meteoadaptogenic properties of a series of drugs with peptide (cortexin, noopept, dilept) and nonpeptide (vinpotropil) structure were investigated in a climate thermobarocomplex (Tabay, Japan) on a group of healthy volunteers aged 20-24. All the studied drugs produced a meteoadaptogenic action, the extent of which depended on the environmental test conditions (overcooling, overheating, hypobaric hypoxia). Vinpotropil, optimizing a physiological component of the functional state, can be recommended as a meteoadaptogen for both cold and hot climate as well as for hypobaric hypoxia, where it improved the psychological component of the functional state. Cortexin is qualified as an adaptogen and actoprotector only for hypobaric hypoxia conditions (uplands). Noopept, affecting positively a psychological component of the functional state, can be used for rapid adaptation to both cold and hot climate. In the hot climate, noopept also enhanced the physical work capacity. Dilept mostly elevated the psychological component of the functional state and can be considered as a psychomotor enhancer and adaptogen. Therefore, all the drugs studied (vinpotropil, cortexin, noopept and dilept) can be recommended as the agents producing activation, support and recovery of the physical and psychological efficiency under rapidly changing environment conditions.

Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

NASA Astrophysics Data System (ADS)

Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

2011-05-01

Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry1,2,3. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago1. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear. First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test. All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

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

Raab, A. E.; Berger, E.; Freudenthaler, J.

Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesivemore » and abrasive tool wear.First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test.All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.« less

The development of anti-heat stress clothing for construction workers in hot and humid weather.

PubMed

Chan, Albert P C; Guo, Y P; Wong, Francis K W; Li, Y; Sun, S; Han, X

2016-04-01

The purpose of this study was to develop anti-heat stress clothing for construction workers in hot and humid weather. Following DeJonge's functional clothing design process, the design situation was explored, including clothing fabric heat/moisture transporting properties and UV protection and the aspects of clothing ergonomic design (mobility, convenience, and safety). The problem structure was derived from the results of the surveys in three local construction sites, which agreed well with the task requirements and observations. Specifications were consequently described and 30 commercially available fabrics were identified and tested. Fabric testing data and design considerations were inputted in S-smart system to predict the thermal functional performance of the clothing. A new uniform prototype was developed and evaluated. The results of all measurements suggest that the new uniform which incorporated fabrics with superior heat/moisture transporting properties and loose-fitting design could reduce the workers' heat stress and improve their comfort and work performance. Practitioner Summary: The construction workers' uniform currently used in Hong Kong during summer was unsatisfactory. Following DeJonge's functional clothing design process, an anti-heat stress uniform was developed by testing 30 fabrics and predicting clothing thermal functional performance using S-smart system. The new uniform could reduce the workers' heat stress and improve their comfort and work performance.

40 CFR 86.1238-96 - Hot soak test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Hot soak test. 86.1238-96 Section 86... Methanol-Fueled Heavy-Duty Vehicles § 86.1238-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately...

40 CFR 86.1238-96 - Hot soak test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Hot soak test. 86.1238-96 Section 86... Methanol-Fueled Heavy-Duty Vehicles § 86.1238-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately...

40 CFR 86.1238-96 - Hot soak test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Hot soak test. 86.1238-96 Section 86... Methanol-Fueled Heavy-Duty Vehicles § 86.1238-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately...

40 CFR 86.1238-96 - Hot soak test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Hot soak test. 86.1238-96 Section 86... Methanol-Fueled Heavy-Duty Vehicles § 86.1238-96 Hot soak test. (a)(1) Gasoline- and methanol-fueled vehicles. For gasoline- and methanol-fueled vehicles, the hot soak test shall be conducted immediately...

Cardiac autonomic function and hot flashes among perimenopausal and postmenopausal women.

PubMed

Gibson, Carolyn J; Mendes, Wendy Berry; Schembri, Michael; Grady, Deborah; Huang, Alison J

2017-07-01

Abnormalities in autonomic function are posited to play a pathophysiologic role in menopausal hot flashes. We examined relationships between resting cardiac autonomic activity and hot flashes in perimenopausal and postmenopausal women. Autonomic function was assessed at baseline and 12 weeks among perimenopausal and postmenopausal women (n = 121, mean age 53 years) in a randomized trial of slow-paced respiration for hot flashes. Pre-ejection period (PEP), a marker of sympathetic activation, was measured with impedance cardiography. Respiratory sinus arrhythmia (RSA), a marker of parasympathetic activation, was measured with electrocardiography. Participants self-reported hot flash frequency and severity in 7-day symptom diaries. Analysis of covariance models were used to relate autonomic function and hot flash frequency and severity at baseline, and to relate changes in autonomic function to changes in hot flash frequency and severity over 12 weeks, adjusting for age, body mass index, and intervention assignment. PEP was not associated with hot flash frequency or severity at baseline or over 12 weeks (P > 0.05 for all). In contrast, there was a trend toward greater frequency of moderate-to-severe hot flashes with higher RSA at baseline (β = 0.43, P = 0.06), and a positive association between change in RSA and change in frequency of moderate-to-severe hot flashes over 12 weeks (β = 0.63, P = 0.04). Among perimenopausal and postmenopausal women with hot flashes, variations in hot flash frequency and severity were not explained by variations in resting sympathetic activation. Greater parasympathetic activation was associated with more frequent moderate-to-severe hot flashes, which may reflect increased sensitivity to perceiving hot flashes.

Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.

PubMed

Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun

2018-03-01

The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

Fabrication and Testing of a Tubular Thermoelectric Module Based on Oxide Elements

NASA Astrophysics Data System (ADS)

Merkulov, O. V.; Politov, B. V.; Chesnokov, K. Yu.; Markov, A. A.; Leonidov, I. A.; Patrakeev, M. V.

2018-02-01

A thermoelectric module with a tubular design, considered as particularly promising for energy recovery from hot exhaust gases of vehicles was fabricated and successfully tested under laboratory condition. The module included 24 functional oxide elements synthesized by conventional methods. Elements of p-type were made of cobalt-based oxide Ca2.7Bi0.3Co4O9, while n-type elements were produced from manganese-based oxide CaMn0.95Ta0.05O3. The module was assembled using silver paste and clamping mechanisms, with the thermoelectric elements electrically connected in series by metal plates (copper, silver) and placed around the hot tube. The output power of 138 mW was achieved under a temperature gradient of 430°C with a hot side temperature of 514°C. The tested module is characterized by an advantageous manufacturing factor of 0.87 at the contact resistance of 0.44 Ω, but a relatively low output power density per volume and per mass. Possible means by which the module's operational characteristics could be improved are considered.

Hot-Fire Testing of a 1N AF-M315E Thruster

NASA Technical Reports Server (NTRS)

Burnside, Christopher G.; Pedersen, Kevin; Pierce, Charles W.

2015-01-01

This hot-fire test continues NASA investigation of green propellant technologies for future missions. To show the potential for green propellants to replace some hydrazine systems in future spacecraft, NASA Marshall Space Flight Center (MSFC) is continuing to embark on hot-fire test campaigns with various green propellant blends. NASA completed a hot-fire test of a 1N AF-M315E monopropellant thruster at the Marshall Space Flight Center in the small altitude test stand located in building 4205. The thruster is a ground test article used for basic performance determination and catalyst studies. The purpose of the hot-fire testing was for performance determination of a 1N size thruster and form a baseline from which to study catalyst performance and life with follow-on testing to be conducted at a later date. The thruster performed as expected. The result of the hot-fire testing are presented in this paper and presentation.

Executive Functions in Children Who Experience Bullying Situations

PubMed Central

Medeiros, Wandersonia; Torro-Alves, Nelson; Malloy-Diniz, Leandro F.; Minervino, Carla M.

2016-01-01

Bullying is characterized by intentional, repetitive, and persistent aggressive behavior that causes damage to the victim. Many studies investigate the social and emotional aspects related to bullying, but few assess the cognitive aspects it involves. Studies with aggressive individuals indicate impairment in executive functioning and decision-making. The objective of this study was to assess hot and cold executive functions in children who experience bullying. A total of 60 children between 10 and 11 years of age were included in the study. They were divided into four groups: aggressors (bullies), victims, bully-victims, and control. Tests for decision-making, inhibitory control, working memory, and cognitive flexibility were used. The bully group made more unfavorable choices on the Iowa Gambling Task, which may indicate difficulties in the decision-making process. The victim group took longer to complete the Trail Making Test (Part B) than aggressors, suggesting lower cognitive flexibility in victims. The hypothesis that aggressors would have lower performance in other executive functions such as inhibitory control, working memory, and cognitive flexibility has not been confirmed. This study indicates that bullies have an impairment of hot executive functions whereas victims have a comparatively lower performance in cold executive functions. In addition to social and cultural variables, neurocognitive and emotional factors seem to influence the behavior of children in bullying situations. PMID:27616998

Modification of the BAX Salmonella test kit to include a hot start functionality (modification of AOAC Official Method 2003.09).

PubMed

Wallace, F Morgan; DiCosimo, Deana; Farnum, Andrew; Tice, George; Andaloro, Bridget; Davis, Eugene; Burns, Frank R

2011-01-01

In 2010, the BAX System PCR assay for Salmonella was modified to include a hot start functionality designed to keep the reaction enzyme inactive until PCR begins. To validate the assay's Official Methods of Analysis status to include this procedure modification, an evaluation was conducted on four food types that were simultaneously analyzed with the BAX System and either the U.S. Food and Drug Administration's Bacteriological Analytical Manual or the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference method for detecting Salmonella. Identical performance between the BAX System method and the reference methods was observed. Additionally, lysates were analyzed using both the BAX System Classic and BAX System Q7 instruments with identical results using both platforms for all samples tested. Of the 100 samples analyzed, 34 samples were positive for both the BAX System and reference methods, and 66 samples were negative by both the BAX System and reference methods, demonstrating 100% correlation. No instrument platform variation was observed. Additional inclusivity and exclusivity testing using the modified test kit demonstrated the test kit to be 100% accurate in evaluation of test panels of 352 Salmonella strains and 46 non-Salmonella strains.

Modeling Deformation Flow Curves and Dynamic Recrystallization of BA-160 Steel During Hot Compression

NASA Astrophysics Data System (ADS)

Shahriari, Babak; Vafaei, Reza; Mohammad Sharifi, Ehsan; Farmanesh, Khosro

2018-03-01

The hot deformation behavior of a high strength low carbon steel was investigated using hot compression test at the temperature range of 850-1100 °C and under strain rates varying from 0.001 to 1 s-1. It was found that the flow curves of the steel were typical of dynamic recrystallization at the temperature of 950 °C and above; at tested strain rates lower than 1 s-1. A very good correlation between the flow stress and Zener-Hollomon parameter was obtained using a hyperbolic sine function. The activation energy of deformation was found to be around 390 kJ mol-1. The kinetics of dynamic recrystallization of the steel was studied by comparing it with a hypothetical dynamic recovery curve, and the dynamically fraction recrystallized was modeled by the Kolmogorov-Johnson-Mehl-Avrami relation. The Avrami exponent was approximately constant around 1.8, which suggested that the type of nucleation was one of site saturation on grain boundaries and edges.

Exercise training reduces the frequency of menopausal hot flushes by improving thermoregulatory control.

PubMed

Bailey, Tom G; Cable, N Timothy; Aziz, Nabil; Dobson, Rebecca; Sprung, Victoria S; Low, David A; Jones, Helen

2016-07-01

Postmenopausal hot flushes occur due to a reduction in estrogen production causing thermoregulatory and vascular dysfunction. Exercise training enhances thermoregulatory control of sweating, skin and brain blood flow. We aimed to determine if improving thermoregulatory control and vascular function with exercise training alleviated hot flushes. Twenty-one symptomatic women completed a 7-day hot flush questionnaire and underwent brachial artery flow-mediated dilation and a cardiorespiratory fitness test. Sweat rate and skin blood flow temperature thresholds and sensitivities, and middle cerebral artery velocity (MCAv) were measured during passive heating. Women performed 16 weeks of supervised exercise training or control, and measurements were repeated. There was a greater improvement in cardiorespiratory fitness (4.45 mL/kg/min [95% CI: 1.87, 8.16]; P = 0.04) and reduced hot flush frequency (48 hot flushes/wk [39, 56]; P < 0.001) after exercise compared with control. Exercise reduced basal core temperature (0.14°C [0.01, 0.27]; P = 0.03) and increased basal MCAv (2.8 cm/s [1.0, 5.2]; P = 0.04) compared with control. Sweat rate and skin blood flow thresholds occurred approximately 0.19°C and 0.17°C earlier, alongside improved sweating sensitivity with exercise. MCAv decreased during heating (P < 0.005), but was maintained 4.5 cm/s (3.6, 5.5; P < 0.005) higher during heating after exercise compared with control (0.6 cm/s [-0.4, 1.4]). Exercise training that improves cardiorespiratory fitness reduces self-reported hot flushes. Improvements are likely mediated through greater thermoregulatory control in response to increases in core temperature and enhanced vascular function in the cutaneous and cerebral circulations.

Concentrator hot-spot testing, phase 1

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.

1987-01-01

Results of a study to determine the hot-spot susceptibility of concentrator cells, to provide a hot-spot qualification test for concentrator modules, and to provide guidelines for reducing hot-spot susceptibility are presented. Hot-spot heating occurs in a photovoltaic module when the short-circuit current of a cell is lower than the string operating current forcing the cell into reverse bias with a concurrent power dissipation. Although the basis for the concentrator module hot-spot qualification test is the test developed for flat-plate modules, issues, such as providing cell illumination, introduce additional complexities into the testing procedure. The same general guidelines apply for protecting concentrator modules from hot-spot stressing as apply to flat-plate modules. Therefore, recommendations are made on the number of bypass diodes required per given number of series cells per module or source circuit. In addition, a new method for determining the cell temperature in the laboratory or in the field is discussed.

Hot-spot heating in central-station arrays

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.

1983-01-01

Hot spot tests performed on the Sacramento Municipal Utility District (SMUD) verificaton array show that current imbalance occurs, resulting in significant hot spot heating. One cause of current imbalance is differences in the average shunt resistances of parallel cell strings due to cell shunt resistance variations. In depth hot spot tests are performed on the verification array with bypass diodes. The tests had several objectives: (1) a comparison of hot spot temperatures achieved under field conditions with those obtained with the present laboratory hot spot test using similar modules; (2) an assessment of current imbalance versus cross tie frequency; and (3) an assessment of different shadow patterns and shadow densities. Instrumented modules are used to vary the number of cross ties and to measure the test-cell current and back-bias voltage. The widths, lengths, and densities of the shadows are varied to maximize the back bias voltage at maximum power current. An infrared camera is used to indicate the existence of hot spots and estimate temperature increases in conjunction with thermocouples. The results of these hot spot tests indicate a sensitivity of back bias heating to the shadow size (amount of cell coverage) and density.

Microstructural evolution in the HAZ of Inconel 718 and correlation with the hot ductility test

NASA Technical Reports Server (NTRS)

Thompson, R. G.; Genculu, S.

1983-01-01

The nickel-base alloy 718 was evaluated to study the role of preweld heat treatment in reducing or eliminating heat-affected zone hot cracking. Three heat treatments were studied using the Gleeble hot ductility test. A modified hot ductility test was also used to follow the evolution of microstructure during simulated welding thermal cycles. The microstructural evolution was correlated with the hot ductility data in order to evaluate the mechanism of hot cracking in alloy 718. The correlation of hot ductility with microstructure showed that recrystallization, grain growth, and dissolution of precipitates did not in themselves cause any loss of ductility during cooling. Ductility loss during cooling was not initiated until the constitutional liquation of NbC particles was observed in the microstructure. Laves-type phases were found precipitated in the solidified grain boundaries but were not found to correlate with any ductility loss parameter. Mechanisms are reviewed which help to explain how heat treatment controls the hot crack susceptibility of alloy 718 as measured in the hot ductility test.

Hot-spot qualification testing of concentrator modules

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.; Sugimura, R. S.; Ross, R. G., Jr.

1987-01-01

Results of a study to determine the hot-spot susceptibility of concentrator cells, to provide a hot-spot qualification test for concentrator modules, and to provide guidelines for reducing hot-spot susceptibility are presented. Hot-spot heating occurs in a photovoltaic module when the short-circuit current of a cell is lower than the string operating current, forcing the cell into reverse bias with a concurrent power dissipation. Although the basis for the concentrator-module hot-spot qualification test is the test developed for flat-plate modules, issues such as providing cell illumination introduce additional complexities into the testing procedure. The results indicate that the same general guidelines apply to protecting concentrator modules from hot-spot stressing as apply to flat-plate modules, and recommendations are made on the number of bypass diodes required per given number of series cells per module or source circuit. A method for determining the cell temperature in the laboratory or in the field is discussed.

The Contributions of "Hot" and "Cool" Executive Function to Children's Academic Achievement, Learning-Related Behaviors, and Engagement in Kindergarten

ERIC Educational Resources Information Center

Brock, Laura L.; Rimm-Kaufman, Sara E.; Nathanson, Lori; Grimm, Kevin J.

2009-01-01

Executive functioning (EF) refers to higher order thought processes considered foundational for problem-solving. EF has both "cool" cognitive and "hot" emotional components. This study asks: (a) what are the relative contributions of "hot" and "cool" EF to children's academic achievement? (b) What are the relative contributions of "hot" and "cool"…

Modulation of Higher-Order Olfaction Components on Executive Functions in Humans.

PubMed

Fagundo, Ana B; Jiménez-Murcia, Susana; Giner-Bartolomé, Cristina; Islam, Mohammed Anisul; de la Torre, Rafael; Pastor, Antoni; Casanueva, Felipe F; Crujeiras, Ana B; Granero, Roser; Baños, Rosa; Botella, Cristina; Fernández-Real, Jose M; Frühbeck, Gema; Gómez-Ambrosi, Javier; Menchón, José M; Tinahones, Francisco J; Fernández-Aranda, Fernando

2015-01-01

The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both executive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test-WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the ''Sniffin' Sticks'' test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All participants were female, aged between 18 and 60. Results showed that participants with hyposmia displayed worse performance in decision making (IGT; Cohen's-d = 0.91) and cognitive flexibility (WCST; Cohen's-d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants' age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive measures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders.

High temperature ultrasonic testing of materials for internal flaws

DOEpatents

Kupperman, David S.; Linzer, Melvin

1990-01-01

An apparatus is disclosed for nondestructive evaluation of defects in hot terials, such as metals and ceramics, by sonic signals, which includes a zirconia buffer in contact with a hot material being tested, a liquid couplant of borax in contact with the zirconia buffer and the hot material to be tested, a transmitter mounted on the zirconia buffer sending sonic signals through the buffer and couplant into the hot material, and a receiver mounted on the zirconia buffer receiving sonic signals reflected from within the hot material through the couplant and the buffer.

The acute effect of coffee on endothelial function and glucose metabolism following a glucose load in healthy human volunteers.

PubMed

Boon, Evan A J; Croft, Kevin D; Shinde, Sujata; Hodgson, Jonathan M; Ward, Natalie C

2017-09-20

A diet rich in plant polyphenols has been suggested to reduce the incidence of cardiovascular disease and type 2 diabetes mellitus, in part, via improvements in endothelial function. Coffee is a rich source of phenolic compounds including the phenolic acid, chlorogenic acid (CGA). The aim of the study was to investigate the effect of coffee as a whole beverage on endothelial function, blood pressure and blood glucose concentration. Twelve healthy men and women were recruited to a randomised, placebo-controlled, cross-over study, with three treatments tested: (i) 18 g of ground caffeinated coffee containing 300 mg CGA in 200 mL of hot water, (ii) 18 g of decaffeinated coffee containing 287 mg CGA in 200 mL of hot water, and (iii) 200 mL of hot water (control). Treatment beverages were consumed twice, two hours apart, with the second beverage consumed simultaneously with a 75 g glucose load. Blood pressure was recorded and the finger prick glucose test was performed at time = 0 and then every 30 minutes up to 2 hours. Endothelial function, assessed using flow-mediated dilatation (FMD) of the brachial artery, was measured at 1 hour and a blood sample taken at 2 hours to measure plasma nitrate/nitrite and 5-CGA concentrations. The FMD response was significantly higher in the caffeinated coffee group compared to both decaffeinated coffee and water groups (P < 0.001). There was no significant difference in the FMD response between decaffeinated coffee and water. Blood glucose concentrations and blood pressure were not different between the three treatment groups. In conclusion, the consumption of caffeinated coffee resulted in a significant improvement in endothelial function, but there was no evidence for benefit regarding glucose metabolism or blood pressure. Although the mechanism has yet to be elucidated the results suggest that coffee as a whole beverage may improve endothelial function, or that caffeine is the component of coffee responsible for improving FMD.

Hot-cracking studies of Inconel 718 weld- heat-affected zones

NASA Technical Reports Server (NTRS)

Thompson, E. G.

1969-01-01

Hot ductility tests, gas-tungsten-arc fillerless fusion tests, and circle patch-weld-restraint tests were conducted on Inconel 718 to better understand and correlate the weldability /resistance to hot cracking/ of the alloy. A correlation of the test results with composition, heat-treat condition, grain size, and microstructure was made.

SSME main combustion chamber life prediction

NASA Technical Reports Server (NTRS)

Cook, R. T.; Fryk, E. E.; Newell, J. F.

1983-01-01

Typically, low cycle fatigue life is a function of the cyclic strain range, the material properties, and the operating temperature. The reusable life is normally defined by the number of strain cycles that can be accrued before severe material degradation occurs. Reusable life is normally signified by the initiation or propagation of surface cracks. Hot-fire testing of channel wall combustors has shown significant mid-channel wall thinning or deformation during accrued cyclic testing. This phenomenon is termed cyclic-creep and appears to be significantly accelerated at elevated surface temperatures. This failure mode was analytically modelled. The cyclic life of the baseline SSME-MCC based on measured calorimeter heat transfer data, and the life sensitivity of local hot spots caused by injector effects were determined. Four life enhanced designs were assessed.

Behavioral Weight Loss for the Management of Menopausal Hot Flashes: A Pilot Study

PubMed Central

Thurston, Rebecca C.; Ewing, Linda J.; Low, Carissa A.; Christie, Aimee J.; Levine, Michele D.

2014-01-01

Objective Although adiposity has been considered protective against hot flashes, newer data suggest positive relations between flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss to reduce hot flashes. Methods Forty overweight/obese women with hot flashes (≥4/day) were randomized to a behavioral weight loss intervention or to wait list control. Hot flashes were assessed pre- and post-intervention via physiologic monitor, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were tested via Wilcoxon tests. Results Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a main motivator to lose weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg, p<.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-week hot flashes: −63.0) than did women in the control (−28.0, p=.03), a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (e.g., r=.47, p=.006). Conclusions This pilot study showed a behavioral weight loss program to be feasible, acceptable, and effective in producing weight loss among overweight/obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior. PMID:24977456

Hot and cold executive functions in youth with psychotic symptoms.

PubMed

MacKenzie, L E; Patterson, V C; Zwicker, A; Drobinin, V; Fisher, H L; Abidi, S; Greve, A N; Bagnell, A; Propper, L; Alda, M; Pavlova, B; Uher, R

2017-12-01

Psychotic symptoms are common in children and adolescents and may be early manifestations of liability to severe mental illness (SMI), including schizophrenia. SMI and psychotic symptoms are associated with impairment in executive functions. However, previous studies have not differentiated between 'cold' and 'hot' executive functions. We hypothesized that the propensity for psychotic symptoms is specifically associated with impairment in 'hot' executive functions, such as decision-making in the context of uncertain rewards and losses. In a cohort of 156 youth (mean age 12.5, range 7-24 years) enriched for familial risk of SMI, we measured cold and hot executive functions with the spatial working memory (SWM) task (total errors) and the Cambridge Gambling Task (decision-making), respectively. We assessed psychotic symptoms using the semi-structured Kiddie Schedule for Affective Disorders and Schizophrenia interview, Structured Interview for Prodromal Syndromes, Funny Feelings, and Schizophrenia Proneness Instrument - Child and Youth version. In total 69 (44.23%) youth reported psychotic symptoms on one or more assessments. Cold executive functioning, indexed with SWM errors, was not significantly related to psychotic symptoms [odds ratio (OR) 1.36, 95% confidence interval (CI) 0.85-2.17, p = 0.204). Poor hot executive functioning, indexed as decision-making score, was associated with psychotic symptoms after adjustment for age, sex and familial clustering (OR 2.37, 95% CI 1.25-4.50, p = 0.008). The association between worse hot executive functions and psychotic symptoms remained significant in sensitivity analyses controlling for general cognitive ability and cold executive functions. Impaired hot executive functions may be an indicator of risk and a target for pre-emptive early interventions in youth.

Time-of-flight secondary ion mass spectrometry study on the distribution of alendronate sodium in drug-loaded ultra-high molecular weight polyethylene.

PubMed

Liu, Xiaomin; Qu, Shuxin; Lu, Xiong; Ge, Xiang; Leng, Yang

2009-12-01

The aim of this study was to investigate the drug distribution in ultra-high molecular weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN), which was developed to treat particle-induced osteolysis after artificial joint replacements, since the drug distribution in UHMWPE could play a key role in controlling drug release. A mixture of UHMWPE powder and ALN was dried and hot pressed to prepare UHMWPE loaded with ALN (UHMWPE-ALN). Fourier transform infrared spectroscopy analysis demonstrated that the hot press had no effect on the functional groups of ALN in UHMWPE-ALN. X-ray diffraction indicated that there was no phase change of the UHMWPE after hot pressing. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra revealed the existence of characteristic elements and functional groups from ALN in UHMWPE-ALN, such as Na+, C3H8N+, PO3(-) and PO3H(-). In addition, SIMS images suggested that ALN did not agglomerate in UHMWPE-ALN. A small punch test and hardness test were carried out and the results indicated that ALN did not affect the mechanical properties at the present content level. The present study demonstrated that it was feasible to fabricate the un-agglomerated distributed drug in UHMWPE with good mechanical properties. This ALN loaded UHMWPE would have potential application in clinics.

Development and test of electromechanical actuators for thrust vector control

NASA Technical Reports Server (NTRS)

Weir, Rae A.; Cowan, John R.

1993-01-01

A road map of milestones toward the goal of a full scale Redesigned Solid Rocket Motor/Flight Support Motor (RSRM/FSM) hot fire test is discussed. These milestones include: component feasibility, full power system demonstration, SSME hot fire tests, and RSRM hot fire tests. The participation of the Marshall Space Flight Center is emphasized.

40 CFR 86.237-94 - Dynamometer test run, gaseous emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... approximately 7.5 miles (12.1 kilometers) and a hot start drive of approximately 3.6 miles (5.8 kilometers). (b... and hot start test. The cold start test is divided into two periods. The first period, representing..., consists of the remainder of the driving schedule, including engine shutdown. The hot start test is...

40 CFR 86.237-94 - Dynamometer test run, gaseous emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... approximately 7.5 miles (12.1 kilometers) and a hot start drive of approximately 3.6 miles (5.8 kilometers). (b... and hot start test. The cold start test is divided into two periods. The first period, representing..., consists of the remainder of the driving schedule, including engine shutdown. The hot start test is...

40 CFR 86.237-94 - Dynamometer test run, gaseous emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... approximately 7.5 miles (12.1 kilometers) and a hot start drive of approximately 3.6 miles (5.8 kilometers). (b... and hot start test. The cold start test is divided into two periods. The first period, representing..., consists of the remainder of the driving schedule, including engine shutdown. The hot start test is...

Hot corrosion testing of Ni-based alloys and coatings in a modified Dean rig

NASA Astrophysics Data System (ADS)

Steward, Jason Reid

Gas turbine blades are designed to withstand a variety of harsh operating conditions. Although material and coating improvements are constantly administered to increase the mean time before turbine refurbishment or replacement, hot corrosion is still considered as the major life-limiting factor in many industrial and marine gas turbines. A modified Dean rig was designed and manufactured at Tennessee Technological University to simulate the accelerated hot corrosion conditions and to conduct screening tests on the new coatings on Ni-based superalloys. Uncoated Ni-based superalloys, Rene 142 and Rene 80, were tested in the modified Dean rig to establish a testing procedure for Type I hot corrosion. The influence of surface treatments on the hot corrosion resistance was then investigated. It was found that grit-blasted specimens showed inferior hot corrosion resistance than that of the polished counterpart. The Dean rig was also used to test model MCrAlY alloys, pack cementation NiAl coatings, and electro-codeposited MCrAlY coatings. Furthermore, the hot corrosion attack on the coated-specimens were also assessed using a statistical analysis approach.

10 CFR 431.86 - Uniform test method for the measurement of energy efficiency of commercial packaged boilers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Boiler That is Capable of Supplying Either Steam or Hot Water—(A) Testing. For purposes of EPCA, before... supplying either steam or hot water either by testing the boiler in the steam mode or by testing it in both... supplying either steam or hot water either by testing the boiler for both efficiencies in steam mode, or by...

40 CFR 86.099-9 - Emission standards for 1999 and later model year light-duty trucks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... § 86.130-96, diurnal plus hot soak measurements: 2.5 grams per test. (2) For the supplemental two-diurnal test sequence described in § 86.130-96, diurnal plus hot soak measurements: 3.0 grams per test. (B..., diurnal plus hot soak measurements: 2.0 grams per test. (2) For the supplemental two-diurnal test sequence...

40 CFR 86.099-9 - Emission standards for 1999 and later model year light-duty trucks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 86.130-96, diurnal plus hot soak measurements: 2.5 grams per test. (2) For the supplemental two-diurnal test sequence described in § 86.130-96, diurnal plus hot soak measurements: 3.0 grams per test. (B..., diurnal plus hot soak measurements: 2.0 grams per test. (2) For the supplemental two-diurnal test sequence...

Photovoltaic module hot spot durability design and test methods

NASA Technical Reports Server (NTRS)

Arnett, J. C.; Gonzalez, C. C.

1981-01-01

As part of the Jet Propulsion Laboratory's Low-Cost Solar Array Project, the susceptibility of fat-plate modules to hot-spot problems is investigated. Hot-spot problems arise in modules when the cells become back-biased and operate in the negative-voltage quadrant, as a result of short-circuit current mismatch, cell cracking or shadowing. The details of a qualification test for determining the capability of modules of surviving field hot-spot problems and typical results of this test are presented. In addition, recommended circuit-design techniques for improving the module and array reliability with respect to hot-spot problems are presented.

Biochemical markers for cardiovascular disease in recently postmenopausal women with or without hot flashes.

PubMed

Tuomikoski, Pauliina; Mikkola, Tomi S; Hämäläinen, Esa; Tikkanen, Matti J; Turpeinen, Ursula; Ylikorkala, Olavi

2010-01-01

Menopausal hot flashes may affect vascular function and perhaps explain conflicting data on cardiovascular disease (CVD) between observational and randomized hormone therapy (HT) studies. We prospectively assessed hot flash status in recently postmenopausal women and related it to a number of biochemical vascular surrogate markers for CVD. Healthy, nonsmoking women (n = 150) exhibiting a broad range (no, mild, moderate, severe) of hot flashes and an onset of menopause within the previous 0.5 to 3 years were studied with laboratory tests for lipids, lipoproteins, apolipoproteins, high-sensitivity C-reactive protein, and sex hormone-binding globulin. Apart from marked differences in hot flashes, the groups showed comparable levels of estrone, estradiol, or free estradiol index. The levels of total cholesterol (3.7-9.1 mmol/L) were similar between the groups (P = 0.744), and hypercholesterolemia (>6.5 mmol/L) was encountered equally often (P = 0.699). No difference was seen in high-, low-, or very low-density lipoproteins, triglycerides, apolipoprotein A-1, apolipoprotein B (or their ratio), or lipoprotein(a) between the groups. The levels of sex hormone-binding globulin and high-sensitivity C-reactive protein correlated negatively with each other (r = -0.204; P = 0.013) but showed no dependence on hot flashes (P = 0.531 and P = 0.215, respectively). No baseline difference in lipid or nonlipid CVD risk factors was observed between women with hot flashes (potential HT users) and women with no or mild hot flashes (potential HT nonusers). This may imply that hot flash status per se cannot explain the difference between observational and randomized trials.

The effects of temporal neck cooling on cognitive function during strenuous exercise in a hot environment: a pilot study.

PubMed

Ando, Soichi; Komiyama, Takaaki; Sudo, Mizuki; Kiyonaga, Akira; Tanaka, Hiroaki; Higaki, Yasuki

2015-05-30

Heat stress potentially has detrimental effects on brain function. Hence, cognitive function may be impaired during physical activity in a hot environment. Skin cooling is often applied in a hot environment to counteract heat stress. However, it is unclear to what extent neck cooling is effective for cognitive impairment during exercise in a hot environment. The purpose of this study was to examine the effects of temporal neck cooling on cognitive function during strenuous exercise in a hot environment. Eight male young participants (mean ± SD, age = 26.1 ± 3.2 years; peak oxygen uptake = 45.6 ± 5.2 ml/kg/min) performed Spatial delayed response (DR) task (working memory) and Go/No-Go task (executive function) at rest and during exercise in the Hot and Hot + Cooling conditions. After the participants completed the cognitive tasks at rest, they cycled the ergometer until their heart rate (HR) reached 160 beats/min. Then, they cycled for 10 min while keeping their HR at 160 beats/min. The cognitive tasks were performed 3 min after their HR reached 160 beats/min. The air temperature was maintained at 35°C and the relative humidity was controlled at 70%. Neck cooling was applied to the backside of the neck by a wet towel and fanning. We used accuracy of the Spatial DR and Go/No-Go tasks and reaction time in the Go/No-Go task to assess cognitive function. Neck cooling temporarily decreased the skin temperature during exercise. The accuracy of the cognitive tasks was lower during exercise than that at rest in the Hot and Hot + Cooling condition (p < 0.05). There were no differences in the accuracy between the Hot and Hot + Cooling conditions (p = 0.98). Neither exercise (p = 0.40) nor cooling (p = 0.86) affected reaction time. These results indicate that temporal neck cooling did not alter cognitive function during strenuous exercise in a hot environment. The present study suggests that temporal neck cooling with a wet towel and fanning is not effective for attenuating impairment of working memory and executive function during strenuous exercise with a short duration in a warm and humid environment.

Respiratory effects of work in retail food stores. III. Pulmonary function findings.

PubMed

Wegman, D H; Eisen, E A; Smith, T J; Greaves, I A; Fine, L J

1987-06-01

Findings are reported from a prospective morbidity study which examined the effects on pulmonary function associated with the particulate and gaseous air contaminants to which retail food store workers are exposed. A total of 685 supermarket employees (including meat wrappers, meat cutters and store clerks) performed standard ventilatory function tests [forced expiratory volume in 1 s (FEV1.0) and forced vital capacity (FVC)] during a base-line survey. Those available four years later (305) were resurveyed in a similar manner. A suggestive chronic effect on pulmonary function was shown in those with high cumulative exposures and allergic history. Among those workers who had continuous exposure to air contaminants in settings with "hot-wire" plastic wrap film cutters the annual rates of change in FEV1.0 and FVC were twice as great as the changes found among comparable workers who were not exposed to fumes from wrapping film. Those who switched from the "hot-wire" to the "cool-rod" cutters during the course of the follow-up had intermediate rates of change in lung function.

High Temperature Materials for Chemical Propulsion Applications

NASA Technical Reports Server (NTRS)

Elam, Sandra; Hickman, Robert; O'Dell, Scott

2007-01-01

Radiation or passively cooled thrust chambers are used for a variety of chemical propulsion functions including apogee insertion, reaction control for launch vehicles, and primary propulsion for planetary spacecraft. The performance of these thrust chambers is limited by the operating temperature of available materials. Improved oxidation resistance and increased operating temperatures can be achieved with the use of thermal barrier coatings such as zirconium oxide (ZrO2) and hafnium oxide (HfO2). However, previous attempts to include these materials showed cracking and spalling of the oxide layer due to poor bonding. Current research at NASA's Marshall Space Flight Center (MSFC) has generated unique, high temperature material options for in-space thruster designs that are capable of up to 2500 C operating temperatures. The research is focused on fabrication technologies to form low cost Iridium,qF_.henium (Ir/Re) components with a ceramic hot wall created as an integral, functionally graded material (FGM). The goal of this effort is to further de?celop proven technologies for embedding a protective ceramic coating within the Ir/Re liner to form a robust functional gradient material. Current work includes the fabrication and testing of subscale samples to evaluate tensile, creep, thermal cyclic/oxidation, and thermophysical material properties. Larger test articles have also being fabricated and hot-fire tested to demonstrate the materials in prototype thrusters at 1O0 lbf thrust levels.

The role of omega-3 on modulation of cognitive deficiency induced by REM sleep deprivation in rats.

PubMed

Nasehi, Mohammad; Nezhad, Seyed Moslem Mousavi; Khakpai, Fatemeh; Zarrindast, Mohammad-Reza

2018-06-02

Prolonged sleep deprivation causes cognitive deficits. In rats, for instance, sleep deprivation weakens spatial learning and long-term potentiation (LTP). We examined the effects of omega-3 on cognitive deficiency induced by REM sleep deprivation (RSD). For this purpose, we used a fear conditioning paradigm, forced swim test (FST) apparatus, and hot plate test. Intravenously omega-3 injection was performed during 3 consecutive days. Rats trained in the fear conditioning apparatus after 24 hours. During conditioning, animals were received foot shocks, either alone or paired with a sound. Sleep deprivation paradigm was carried out in which REM sleep was completely prevented and non-REM sleep was intensely declined for 24 hours. Then, context-dependent retention, anxiety behaviors, and hot plate tests were done. Auditory-dependent retention, anxiety behaviors, and FST were carried out 24 hours later. 24 hours of RSD impaired cognitive function, however intravenously administration of omega-3 improved (0.25, 0.5 and 1 mg/kg) context- or auditory-dependent memory, induced anxiolytic (1 mg/kg), antidepressant (1.25 mg/kg), and anti-nociceptive (0.25 mg/kg) effects. The results revealed that RSD interferes with the neural systems underlying cognitive functions and supports the involvement of omega-3 in the modulation of cognitive functions. Copyright © 2018. Published by Elsevier B.V.

46 CFR 115.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Inspection and testing prior to hot work. 115.710 Section 115.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... AND CERTIFICATION Repairs and Alterations § 115.710 Inspection and testing prior to hot work. (a) An...

46 CFR 176.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Inspection and testing prior to hot work. 176.710 Section 176.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... testing prior to hot work. (a) An inspection for flammable or combustible gases must be conducted by a...

46 CFR 176.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Inspection and testing prior to hot work. 176.710 Section 176.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... testing prior to hot work. (a) An inspection for flammable or combustible gases must be conducted by a...

46 CFR 115.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Inspection and testing prior to hot work. 115.710 Section 115.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... AND CERTIFICATION Repairs and Alterations § 115.710 Inspection and testing prior to hot work. (a) An...

46 CFR 176.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Inspection and testing prior to hot work. 176.710 Section 176.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... testing prior to hot work. (a) An inspection for flammable or combustible gases must be conducted by a...

46 CFR 115.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Inspection and testing prior to hot work. 115.710 Section 115.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... AND CERTIFICATION Repairs and Alterations § 115.710 Inspection and testing prior to hot work. (a) An...

46 CFR 176.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Inspection and testing prior to hot work. 176.710 Section 176.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... testing prior to hot work. (a) An inspection for flammable or combustible gases must be conducted by a...

46 CFR 115.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Inspection and testing prior to hot work. 115.710 Section 115.710 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... AND CERTIFICATION Repairs and Alterations § 115.710 Inspection and testing prior to hot work. (a) An...

46 CFR 115.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Inspection and testing prior to hot work. 115.710... AND CERTIFICATION Repairs and Alterations § 115.710 Inspection and testing prior to hot work. (a) An... involving riveting, welding, burning, or other fire producing actions may be made aboard a vessel: (1...

Hot-Fire Test Results of Liquid Oxygen/RP-2 Multi-Element Oxidizer-Rich Preburners

NASA Technical Reports Server (NTRS)

Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.; Hulka, J. R.

2016-01-01

As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. To supply the oxidizer-rich combustion products to the main injector of the integrated test article, existing subscale preburner injectors from a previous NASA-funded oxidizer-rich staged combustion engine development program were utilized. For the integrated test article, existing and newly designed and fabricated inter-connecting hot gas duct hardware were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. However, before one of the preburners was used in the integrated test article, it was first hot-fire tested at length to prove it could provide the hot exhaust gas mean temperature, thermal uniformity and combustion stability necessary to perform in the integrated test article experiment. This paper presents results from hot-fire testing of several preburner injectors in a representative combustion chamber with a sonic throat. Hydraulic, combustion performance, exhaust gas thermal uniformity, and combustion stability data are presented. Results from combustion stability modeling of these test results are described in a companion paper at this JANNAF conference, while hot-fire test results of the preburner injector in the integrated test article are described in another companion paper.

Hot tearing studies in AA5182

NASA Astrophysics Data System (ADS)

van Haaften, W. M.; Kool, W. H.; Katgerman, L.

2002-10-01

One of the major problems during direct chill (DC) casting is hot tearing. These tears initiate during solidification of the alloy and may run through the entire ingot. To study the hot tearing mechanism, tensile tests were carried out in semisolid state and at low strain rates, and crack propagation was studied in situ by scanning electron microscopy (SEM). These experimentally induced cracks were compared with hot tears developed in an AA5182 ingot during a casting trial in an industrial research facility. Similarities in the microstructure of the tensile test specimens and the hot tears indicate that hot tearing can be simulated by performing tensile tests at semisolid temperatures. The experimental data were compared with existing hot tearing models and it was concluded that the latter are restricted to relatively high liquid fractions because they do not take into account the existence of solid bridges in the crack.

Behavioral weight loss for the management of menopausal hot flashes: a pilot study.

PubMed

Thurston, Rebecca C; Ewing, Linda J; Low, Carissa A; Christie, Aimee J; Levine, Michele D

2015-01-01

Although adiposity has been considered to be protective against hot flashes, newer data suggest positive relationships between hot flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss in reducing hot flashes. Forty overweight or obese women with hot flashes (≥ 4 hot flashes/d) were randomized to either behavioral weight loss intervention or wait-list control. Hot flashes were assessed before and after intervention via physiologic monitoring, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were performed via Wilcoxon tests. Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a major motivator for losing weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg; P < 0.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-wk hot flashes, -63.0) than did women in the control group (-28.0; P = 0.03)-a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (eg, r = 0.47, P = 0.006). This pilot study shows a behavioral weight loss program that is feasible, acceptable, and effective in producing weight loss among overweight or obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior.

The effect of cushion-ram pulsation on hot stamping

NASA Astrophysics Data System (ADS)

Landgrebe, Dirk; Rautenstrauch, Anja; Kunke, Andreas; Polster, Stefan; Kriechenbauer, Sebastian; Mauermann, Reinhard

2016-10-01

Hot stamping is an important technology for manufacturing high-strength components. This technology offers the possibility to achieve significant weight reductions. In this study, cushion-ram pulsation (CRP), a new technology for hot stamping on servo-screw presses, was investigated and applied for hot stamping. Compared to a conventional process, the tests yielded a significantly higher drawing depth. In this paper, the CRP technology and the first test results with hot stamping were described in comparison to the conventional process.

40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (4) If a failure to start occurs during the hot start portion of the test and is caused by engine... stalling. (1) If the engine stalls during the initial idle period of either the cold or hot start test, the engine shall be restarted immediately using the appropriate cold or hot starting procedure and the test...

40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (4) If a failure to start occurs during the hot start portion of the test and is caused by engine... stalling. (1) If the engine stalls during the initial idle period of either the cold or hot start test, the engine shall be restarted immediately using the appropriate cold or hot starting procedure and the test...

40 CFR 86.1336-84 - Engine starting, restarting, and shutdown.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (4) If a failure to start occurs during the hot start portion of the test and is caused by engine... stalling. (1) If the engine stalls during the initial idle period of either the cold or hot start test, the engine shall be restarted immediately using the appropriate cold or hot starting procedure and the test...

46 CFR 176.710 - Inspection and testing prior to hot work.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Inspection and testing prior to hot work. 176.710... testing prior to hot work. (a) An inspection for flammable or combustible gases must be conducted by a... operations involving riveting, welding, burning, or other fire producing actions may be made aboard a vessel...

Performance study of protective clothing against hot water splashes: from bench scale test to instrumented manikin test.

PubMed

Lu, Yehu; Song, Guowen; Wang, Faming

2015-03-01

Hot liquid hazards existing in work environments are shown to be a considerable risk for industrial workers. In this study, the predicted protection from fabric was assessed by a modified hot liquid splash tester. In these tests, conditions with and without an air spacer were applied. The protective performance of a garment exposed to hot water spray was investigated by a spray manikin evaluation system. Three-dimensional body scanning technique was used to characterize the air gap size between the protective clothing and the manikin skin. The relationship between bench scale test and manikin test was discussed and the regression model was established to predict the overall percentage of skin burn while wearing protective clothing. The results demonstrated strong correlations between bench scale test and manikin test. Based on these studies, the overall performance of protective clothing against hot water spray can be estimated on the basis of the results of the bench scale hot water splashes test and the information of air gap size entrapped in clothing. The findings provide effective guides for the design and material selection while developing high performance protective clothing. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

Effects of surface chemistry on hot corrosion life

NASA Technical Reports Server (NTRS)

Fryxell, R. E.; Leese, G. E.

1985-01-01

This program has its primary objective: the development of hot corrosion life prediction methodology based on a combination of laboratory test data and evaluation of field service turbine components which show evidence of hot corrosion. The laboratory program comprises burner rig testing by TRW. A summary of results is given for two series of burner rig tests. The life prediction methodology parameters to be appraised in a final campaign of burner rig tests are outlined.

Development of a valid Simplified Chinese version of the International Hip Outcome Tool (SC-iHOT-33) in young patients having total hip arthroplasty.

PubMed

Li, D H; Wang, W; Li, X; Gao, Y L; Liu, D H; Liu, D L; Xu, W D

2017-01-01

The International Hip Outcome Tool (iHOT-33) is a questionnaire designed for young, active patients with hip disorders. It has proven to be a highly reliable and valid questionnaire. The main purpose of our study was to adapt the iHOT-33 questionnaire into simplified Chinese and to assess its psychometric properties in Chinese patients. The iHOT-33 was cross culturally adapted into Chinese and 138 patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the EuroQol-5D (EQ-5D), and the Chinese version of the iHOT-33(SC-iHOT-33) pre- or postoperatively within 6 months' follow-up. The Cronbach's alpha, intraclass correlation coefficient (ICC), Pearson's correlation coefficient (r), effect size (ES), and standardized response mean (SRM) were calculated to assess the reliability, validity, and responsiveness of the SC-iHOT-33, respectively. Total Cronbach's alpha was 0.965, which represented excellent internal consistency of the SC-iHOT-33. The ICC ranges from 0.866 to 0.929, which shows excellent test-retest reliability. The subscales of SC-iHOT-33 had the highest correlation coefficient (r = 0.812) with the physical function subscales of the WOMAC, as well as good correlation between the social/emotional subscale of the SC-iHOT-33 and the EQ-5D (r = 0.740, r = 0.743). No floor or ceiling effects were found. The ES and SRM values indicated good responsiveness of 2.44 and 2.67, respectively. The SC-iHOT-33 questionnaire is reliable, valid, and responsive for the evaluation of young, Chinese, active patients with hip disorders. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Hot-Film and Hot-Wire Anemometry for a Boundary Layer Active Flow Control Test

NASA Technical Reports Server (NTRS)

Lenahan, Keven C.; Schatzman, David M.; Wilson, Jacob Samuel

2013-01-01

Unsteady active flow control (AFC) has been used experimentally for many years to minimize bluff-body drag. This technology could significantly improve performance of rotorcraft by cleaning up flow separation. It is important, then, that new actuator technologies be studied for application to future vehicles. A boundary layer wind tunnel was constructed with a 1ft-x-3ft test section and unsteady measurement instrumentation to study how AFC manipulates the boundary layer to overcome adverse pressure gradients and flow separation. This unsteady flow control research requires unsteady measurement methods. In order to measure the boundary layer characteristics, both hot-wire and hot-film Constant Temperature Anemometry is used. A hot-wire probe is mounted in the flow to measure velocity while a hot-film array lays on the test surface to measure skin friction. Hot-film sensors are connected to an anemometer, a Wheatstone bridge circuit with an output that corresponds to the dynamic flow response. From this output, the time varying flow field, turbulence, and flow reversal can be characterized. Tuning the anemometers requires a fan test on the hot-film sensors to adjust each output. This is a delicate process as several variables drastically affect the data, including control resistance, signal input, trim, and gain settings.

Hot-Fire Testing of 5N and 22N HPGP Thrusters

NASA Technical Reports Server (NTRS)

Burnside, Christopher G.; Pedersen, Kevin W.; Pierce, Charles W.

2015-01-01

This hot-fire test continues NASA investigation of green propellant technologies for future missions. To show the potential for green propellants to replace some hydrazine systems in future spacecraft, NASA Marshall Space Flight Center (MSFC) is continuing to embark on hot-fire test campaigns with various green propellant blends.NASA completed hot-fire testing of 5N and 22N HPGP thrusters at the Marshall Space Flight Center’s Component Development Area altitude test stand in April 2015. Both thrusters are ground test articles and not flight ready units, but are representative of potential flight hardware with a known path towards flight application. The purpose of the 5N testing was to perform facility check-outs and generate a small set of data for comparison to ECAPS and Orbital ATK data sets. The 5N thruster performed as expected with thrust and propellant flow-rate data generated that are similar to previous testing at Orbital ATK. Immediately following the 5N testing, and using the same facility, the 22N testing was conducted on the same test stand with the purpose of demonstrating the 22N performance. The results of 22N testing indicate it performed as expected.The results of the hot-fire testing are presented in this paper and presentation.

Investigation of the prevalence of Legionella species in domestic hot water systems.

PubMed

Bates, M N; Maas, E; Martin, T; Harte, D; Grubner, M; Margolin, T

2000-06-09

To investigate the prevalence of Legionella spp. in the hot water systems of a representative sample of Wellington domestic residences with electrically heated hot water systems, and to investigate risk factors (eg water temperature, plumbing materials) for such contamination. 100 households with electrically heated hot water systems in the Wellington area were investigated. Samples of hot water from several hot water outlets were collected, and characteristics of the plumbing system were recorded. Water samples and swabs were cultured and further examined by polymerase chain reaction (PCR) and direct fluorescence antibody (DFA) testing to identify Legionella spp. and serogroups. No Legionella spp. were isolated by culture. PCR tested positive for Legionella in specimens from twelve residences. Six of these were also positive by DFA testing. The only environmental factor found to be associated with the presence of Legionella was recent plumbing work on the hot water system. Five of the twelve PCR-positive residences, and four of the six DFA-confirmed residences had hot water delivery temperatures in excess of 60 degrees C. The results suggest that either Legionellae colonise domestic hot water reticulation systems and/or that the organisms are killed during passage through the hot water tank. Both possibilities may be correct. Further work to characterise the microbial ecology of Legionella-positive hot water distribution systems would be useful, as would the development of improved methods for culturing the organisms from potable water.

Imaging-based optical caliper for objects in hot manufacturing processes

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

Huang, Howard

OG Technologies, Inc. (OGT), in conjunction with its industrial and academic partners, proposes to develop an Imaging-Based Optical Caliper (hereafter referred to as OC) for Objects in Hot Manufacturing Processes. The goal is to develop and demonstrate the OC with the synergy of OGT's current technological pool and other innovations to provide a light weight, robust, safe and accurate portable dimensional measurement device for hot objects with integrated wireless communication capacity to enable real time process control. The technical areas of interest in this project are the combination of advanced imaging, Sensor Fusion, and process control. OGT believes that themore » synergistic interactions between its current set of technologies and other innovations could deliver products that are viable and have high impact in the hot manufacture processes, such as steel making, steel rolling, open die forging, and glass industries, resulting in a new energy efficient control paradigm in the operations through improved yield, prolonged tool life and improved quality. In-line dimension measurement and control is of interest to the steel makers, yet current industry focus is on the final product dimension only instead of whole process due to the limit of man power, system cost and operator safety concerns. As sensor technologies advances, the industry started to see the need to enforce better dimensional control throughout the process, but lack the proper tools to do so. OGT along with its industrial partners represent the indigenous effort of technological development to serve the US steel industry. The immediate market that can use and get benefited from the proposed OC is the Steel Industry. The deployment of the OC has the potential to provide benefits in reduction of energy waste, CO2 emission, waste water amount, toxic waste, and so forth. The potential market after further expended function includes Hot Forging and Freight Industries. The OC prototypes were fabricated, and were progressively tested on-site in several steel mill and hot forging facilities for evaluation. Software refinements and new calibration procedures were also carried out to overcome the discovered glitches. Progress was presented to the hot manufacture facilities worldwide. Evidence showed a great interest and practical need for this product. OGT is in the pilot commercialization mode for this new development. The R&D team also successfully developed a 3D measurement function with no additional investment of hardware or equipment to measure low or room temperature object dimensions. Several tests were conducted in the reality environment to evaluate the measurement results. This new application will require additional development in product design.« less

Orbital transfer vehicle oxygen turbopump technology. Volume 3: Hot oxygen testing

NASA Technical Reports Server (NTRS)

Urke, Robert L.

1992-01-01

This report covers the work done in preparation for a liquid oxygen rocket engine turbopump test utilizing high pressure hot oxygen gas for the turbine drive. The turbopump (TPA) is designed to operate with 400 F oxygen turbine drive gas. The goal of this test program was to demonstrate the successful operation of the TPA under simulated engine conditions including the hot oxygen turbine drive. This testing follows a highly successful series of tests pumping liquid oxygen with gaseous nitrogen as the turbine drive gas. That testing included starting of the TPA with no assist to the hydrostatic bearing. The bearing start entailed a rubbing start until the pump generated enough pressure to support the bearing. The articulating, self-centering hydrostatic bearing exhibited no bearing load or stability problems. The TPA was refurbished for the hot gas drive tests and facility work was begun, but unfortunately funding cuts prohibited the actual testing.

Advanced Manufacturing Technologies (AMT): Additive Manufactured Hot Fire Planning and Testing in GRC Cell 32 Project

NASA Technical Reports Server (NTRS)

Fikes, John C.

2014-01-01

The objective of this project is to hot fire test an additively manufactured thrust chamber assembly TCA (injector and thrust chamber). GRC will install the additively manufactured Inconel 625 injector, two additively manufactured (SLM) water cooled Cu-Cr thrust chamber barrels and one additively manufactured (SLM) water cooled Cu-Cr thrust chamber nozzle on the test stand in Cell 32 and perform hot fire testing of the integrated TCA.

Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during a dry season in the tropics

NASA Astrophysics Data System (ADS)

Laban, S.; Oue, H.; Rampisela, D. A.

2018-05-01

Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during the 2nd dry season were analyzed in this study. Actual evapotranspiration (ET) was estimated by Bowen Ratio Energy Budget (BREB) method, potential evaporation (EP) was calculated by Penman method, and irrigation volume of water was measured manually. Meteorological instruments were installed in the experimental field during hot pepper cultivation. Leaf area index increased during the growing stages where the highest LAI of 1.65 in the generative stage. The daily average of ET was 1.94 and EP was 6.71 mm resulting in low Kc. The Kc values were significantly different between stage to stage under T-test analysis (α = 0.05). Moreover, Kc in every stage could be related to soil water content (SWC) in logarithmic function. Totally, ET during hot pepper cultivation was 179.19 mm, while rainfall was 180.0 mm and irrigation water was 27.42 mm. However, there was a water shortages during vegetative and generative stages. This study suggested that consumptive water of hot pepper was complimented by soil and groundwater under the condition of water shortages in the vegetative and generative stages during the 2nd dry season.

Video File - NASA Conducts 2nd RS-25 Engine Hot Fire of 2018 - 2018-02-01

NASA Image and Video Library

2018-02-01

NASA Conducts 2nd RS-25 Engine Hot Fire of 2018. A 365-second hot fire test on Feb. 1, 2018, at NASA’s Stennis Space Center in Mississippi marks the completion of “green run” testing, or flight certification, for all new RS-25 engine flight controllers slated for Exploration Mission-2, the first Space Launch System mission with astronauts on board. In addition to the flight controller, the Feb. 1 hot fire also marked the third test of a 3D printed pogo accumulator assembly for the RS-25 engine.

Operating experience with a 250 kW el molten carbonate fuel cell (MCFC) power plant

NASA Astrophysics Data System (ADS)

Bischoff, Manfred; Huppmann, Gerhard

The MTU MCFC program is carried out by a European consortium comprising the German companies MTU Friedrichshafen GmbH, Ruhrgas AG and RWE Energie AG as well as the Danish company Energi E2 S/A. MTU acts as consortium leader. The company shares a license and technology exchange agreement with Fuel Cell Energy Inc., Danbury, CT, USA (formerly Energy Research Corp., ERC). The program was started in 1990 and covers a period of about 10 years. The highlights of this program to date are: Considerable improvements regarding component stability have been demonstrated on laboratory scale. Manufacturing technology has been developed to a point which enables the consortium to fabricate the porous components on a 250 cm 2 scale. Several large area stacks with 5000-7660 cm 2 cell area and a power range of 3-10 kW have been tested at the facilities in Munich (Germany) and Kyndby (Denmark). These stacks have been supplied by FCE. As far as the system design is concerned it was soon realized that conventional systems do not hold the promise for competitive power plants. A system analysis led to the conclusion that a new innovative design approach is required. As a result the "Hot Module" system was developed by the consortium. A Hot Module combines all the components of a MCFC system operating at the similar temperatures and pressures into a common thermally insulated vessel. In August 1997 the consortium started its first full size Hot Module MCFC test plant at the facilities of Ruhrgas AG in Dorsten, Germany. The stack was assembled in Munich using 292 cell packages purchased from FCE. The plant is based on the consortium's unique and proprietary "Hot Module" concept. It operates on pipeline natural gas and was grid connected on 16 August 1997. After a total of 1500 h of operation, the plant was intentionally shut down in a controlled manner in April 1998 for post-test analysis. The Hot Module system concept has demonstrated its functionality. The safety concept has been convincingly proven, though in part unintentionally. The electrical power level of 155 kW (ca. 60% of maximum power) achieved allows validation of the concept with reasonable degree of confidence. Horizontal stack operation—an essential innovation of the Hot Module concept—is feasible. The fuel processing subsystem worked reliably as expected. After initial problems in the inverter control software, the electrical and control subsystem operated to full satisfaction. Stable automatic operation not only under various load conditions, but also in idle mode, hot parking mode, and grid-independent mode has been demonstrated. Together with progress achieved by FCE in the qualification of large direct fuel cell (DFC) stacks the basis was laid for the next test unit of similar design, which will be operated in Bielefeld, Germany. The pre-tests of the stack took place already in July 1999 with good results. Additionally, projects for the test of the DFC Hot Module operating on biogas and other opportunity fuels are under preparation.

HOT CELL BUILDING, TRA632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA FACING EASTERLY. HOT CELL BUILDING IS AT CENTER LEFT OF VIEW; THE LOW-BAY PROJECTION WITH LADDER IS THE TEST TRAIN ASSEMBLY FACILITY, ADDED IN 1968. MTR BUILDING IS IN LEFT OF VIEW. HIGH-BAY BUILDING AT RIGHT IS THE ENGINEERING TEST REACTOR BUILDING, TRA-642. INL NEGATIVE NO. HD46-32-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Hot gas ingestion test results of a two-poster vectored thrust concept with flow visualization in the NASA Lewis 9- by 15-foot low speed wind tunnel

NASA Technical Reports Server (NTRS)

Johns, Albert L.; Neiner, George; Bencic, Timothy J.; Flood, Joseph D.; Amuedo, Kurt C.

1990-01-01

A 9.2 percent scale STOVL hot gas ingestion model was tested in the NASA Lewis 9 x 15-foot Low-Speed Wind Tunnel. Flow visualization from the Phase 1 test program, which evaluated the hot ingestion phenomena and control techniques, is covered. The Phase 2 test program evaluated the hot gas ingestion phenomena at higher temperatures and used a laser sheet to investigate the flow field. Hot gas ingestion levels were measured for the several forward nozzle splay configurations and with flow control/life improvement devices (LIDs) which reduced the hot gas ingestion. The test was conducted at full scale nozzle pressure ratios and inlet Mach numbers. Results are presented over a range of nozzle pressure ratios at a 10 kn headwind velocity. The Phase 2 program was conducted at exhaust nozzle temperatures up to 1460 R and utilized a sheet laser system for flow visualization of the model flow field in and out of ground effects. The results reported are for nozzle exhaust temperatures up to 1160 R and contain the compressor face pressure and temperature distortions, the total pressure recovery, the inlet temperature rise, and the environmental effects of the hot gas. The environmental effects include the ground plane contours, the model airframe heating, and the location of the ground flow separation.

Hot flashes in breast cancer survivors: Frequency, severity and impact.

PubMed

Chang, Hao-Yuan; Jotwani, Aparna C; Lai, Yeur-Hur; Jensen, Mark P; Syrjala, Karen L; Fann, Jesse R; Gralow, Julie

2016-06-01

To (1) determine the frequency and severity of hot flashes, (2) examine the associations between hot flash frequency and severity and quality of life, and (3) identify the predictors of hot flash activity in breast cancer survivors. The study used a cross-sectional design and mailed survey of 253 breast cancer survivors recruited from a cancer wellness clinic. Participants provided information regarding cancer history, hot flashes, pain intensity, sleep problems, physical functioning, and psychological functioning. About half of the survivors reported at least one hot flash in the past 24 h (45%) or past week (52%). The average frequency of hot flashes was 1.9 in the past 24 h and 1.8 in the past week. Hot flash severity was usually mild or asymptomatic. However, participants with hot flashes reported significantly more sleep problems and higher pain severity than those reporting no hot flashes. Moreover, the severity of hot flashes was associated with more sleep problems, higher pain severity, and more psychological dysfunction. History of hormonal suppression therapy and younger age predicted hot flash activity in the study sample. In breast cancer survivors, hot flashes are common and are associated with unpleasant symptoms and poor quality of life. Research is needed to determine if treatments that reduce the frequency and severity of hot flashes in breast cancer survivors also result in improvements in symptoms such as sleep problems, pain, and psychological dysfunction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hot flashes in breast cancer survivors: Frequency, severity and impact

PubMed Central

Chang, Hao-Yuan; Jotwani, Aparna C.; Lai, Yeur-Hur; Jensen, Mark P.; Syrjala, Karen L.; Fann, Jesse R.; Gralow, Julie

2018-01-01

Purposes To (1) determine the frequency and severity of hot flashes, (2) examine the associations be- tween hot flash frequency and severity and quality of life, and (3) identify the predictors of hot flash activity in breast cancer survivors. Methods The study used a cross-sectional design and mailed survey of 253 breast cancer survivors recruited from a cancer wellness clinic. Participants provided information regarding cancer history, hot flashes, pain intensity, sleep problems, physical functioning, and psychological functioning. Results About half of the survivors reported at least one hot flash in the past 24 h (45%) or past week (52%). The average frequency of hot flashes was 1.9 in the past 24 h and 1.8 in the past week. Hot flash severity was usually mild or asymptomatic. However, participants with hot flashes reported significantly more sleep problems and higher pain severity than those reporting no hot flashes. Moreover, the severity of hot flashes was associated with more sleep problems, higher pain severity, and more psychological dysfunction. History of hormonal suppression therapy and younger age predicted hot flash activity in the study sample. Conclusions In breast cancer survivors, hot flashes are common and are associated with unpleasant symptoms and poor quality of life. Research is needed to determine if treatments that reduce the frequency and severity of hot flashes in breast cancer survivors also result in improvements in symptoms such as sleep problems, pain, and psychological dysfunction. PMID:27065357

40 CFR 86.1227-96 - Test procedures; overview.

Code of Federal Regulations, 2012 CFR

2012-07-01

... evaporative emissions as a consequence of diurnal temperature fluctuation urban driving and hot soaks during...; this test is not required for gaseous-fueled vehicles); and (3) Hot soak losses, which result when the vehicle is parked and the hot engine is turned off, measured by the enclosure technique (see § 86.1238...

Effect of sulfur and magnesium on hot ductility and pitting corrosion for Inconel 690 alloy

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

Liu, K.; Zhang, B.; Zhang, S.

1995-12-31

A series of hot tensile tests has been performed to study the effect of sulfur and magnesium on hot ductility of Inconel 690 alloy. The hot ductility has been evaluated from the reduction of area in hot tensile tests using a Gleeble testing machine. The value of reduction in area decreased with increasing sulfur content in the temperature range from 900 C to 1,200 C. When sulfur content was larger than 0.0025%, a ductility dip appeared, and the greater the sulfur content, the deeper and wider the ductility dip. The Scanning Electron Microscope (SEM) analyses showed that the fracture appearancesmore » changed gradually from transgranular to intergranular with increasing sulfur content, meanwhile sulfur and titanium segregation were observed at grain boundaries. The ductility dip of 690 alloy with relatively higher sulfur content could be inhibited by adding appropriate amount of magnesium. However, excessive addition led to magnesium precipitation, which was detrimental to hot ductility. The pitting test has also been conducted and the results showed that pitting rate obviously increased with increasing sulfur content.« less

Stability of hot electron plasma in the ELMO bumpy torus

NASA Astrophysics Data System (ADS)

Tsang, K. T.; Cheng, C. Z.

The stability of a hot electron plasma in the ELMO Bumpy Torus was investigated using two different models. In the first model, where the hot electron distribution function is assumed to be a delta function in the perpendicular velocity, a stability boundary in addition to those discussed by Nelson and by Van Dam and Lee is found. In the second model, where the hot electron distribution function is assumed to be a Maxwellian in the perpendicular velocity, stability boundaries significantly different from those of the first model are found. Coupling of the Nelson-Van Dam-Lee mode to the compressional Alfven mode is now possible. This leads to a higher permissible core plasma beta value for stable operation.

Are hotspots always hotspots? The relationship between diversity, resource and ecosystem functions in the Arctic.

PubMed

Link, Heike; Piepenburg, Dieter; Archambault, Philippe

2013-01-01

The diversity-ecosystem function relationship is an important topic in ecology but has not received much attention in Arctic environments, and has rarely been tested for its stability in time. We studied the temporal variability of benthic ecosystem functioning at hotspots (sites with high benthic boundary fluxes) and coldspots (sites with lower fluxes) across two years in the Canadian Arctic. Benthic remineralisation function was measured as fluxes of oxygen, silicic acid, phosphate, nitrate and nitrite at the sediment-water interface. In addition we determined sediment pigment concentration and taxonomic and functional macrobenthic diversity. To separate temporal from spatial variability, we sampled the same nine sites from the Mackenzie Shelf to Baffin Bay during the same season (summer or fall) in 2008 and 2009. We observed that temporal variability of benthic remineralisation function at hotspots is higher than at coldspots and that taxonomic and functional macrobenthic diversity did not change significantly between years. Temporal variability of food availability (i.e., sediment surface pigment concentration) seemed higher at coldspot than at hotspot areas. Sediment chlorophyll a (Chl a) concentration, taxonomic richness, total abundance, water depth and abundance of the largest gallery-burrowing polychaete Lumbrineristetraura together explained 42% of the total variation in fluxes. Food supply proxies (i.e., sediment Chl a and depth) split hot- from coldspot stations and explained variation on the axis of temporal variability, and macrofaunal community parameters explained variation mostly along the axis separating eastern from western sites with hot- or coldspot regimes. We conclude that variability in benthic remineralisation function, food supply and diversity will react to climate change on different time scales, and that their interactive effects may hide the detection of progressive change, particularly at hotspots. Time-series of benthic functions and its related parameters should be conducted at both hot- and coldspots to produce reliable predictive models.

Hot-spot heating susceptibility due to reverse bias operating conditions

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.

1985-01-01

Because of field experience (indicating that cell and module degradation could occur as a result of hot spot heating), a laboratory test was developed at JPL to determine hot spot susceptibility of modules. The initial hot spot testing work at JPL formed a foundation for the test development. Test parameters are selected as follows. For high shunt resistance cells, the applied back bias test current is set equal to the test cell current at maximum power. For low shunt resistance cells, the test current is set equal to the cell short circuit current. The shadow level is selected to conform to that which would lead to maximum back bias voltage under the appropriate test current level. The test voltage is determined by the bypass diode frequency. The test conditions are meant to simulate the thermal boundary conditions for 100 mW/sq cm, 40C ambient environment. The test lasts 100 hours. A key assumption made during the development of the test is that no current imbalance results from the connecting of multiparallel cell strings. Therefore, the test as originally developed was applicable for single string case only.

User's Manual and Final Report for Hot-SMAC GUI Development

NASA Technical Reports Server (NTRS)

Yarrington, Phil

2001-01-01

A new software package called Higher Order Theory-Structural/Micro Analysis Code (HOT-SMAC) has been developed as an effective alternative to the finite element approach for Functionally Graded Material (FGM) modeling. HOT-SMAC is a self-contained package including pre- and post-processing through an intuitive graphical user interface, along with the well-established Higher Order Theory for Functionally Graded Materials (HOTFGM) thermomechanical analysis engine. This document represents a Getting Started/User's Manual for HOT-SMAC and a final report for its development. First, the features of the software are presented in a simple step-by-step example where a HOT-SMAC model representing a functionally graded material is created, mechanical and thermal boundary conditions are applied, the model is analyzed and results are reviewed. In a second step-by-step example, a HOT-SMAC model of an actively cooled metallic channel with ceramic thermal barrier coating is built and analyzed. HOT-SMAC results from this model are compared to recently published results (NASA/TM-2001-210702) for two grid densities. Finally, a prototype integration of HOTSMAC with the commercially available HyperSizer(R) structural analysis and sizing software is presented. In this integration, local strain results from HyperSizer's structural analysis are fed to a detailed HOT-SMAC model of the flange-to-facesheet bond region of a stiffened panel. HOT-SMAC is then used to determine the peak shear and peel (normal) stresses between the facesheet and bonded flange of the panel and determine the "free edge" effects.

Hot-wire calibration in subsonic/transonic flow regimes

NASA Technical Reports Server (NTRS)

Nagabushana, K. A.; Ash, Robert L.

1995-01-01

A different approach for calibrating hot-wires, which simplifies the calibration procedure and reduces the tunnel run-time by an order of magnitude was sought. In general, it is accepted that the directly measurable quantities in any flow are velocity, density, and total temperature. Very few facilities have the capability of varying the total temperature over an adequate range. However, if the overheat temperature parameter, a(sub w), is used to calibrate the hot-wire then the directly measurable quantity, voltage, will be a function of the flow variables and the overheat parameter i.e., E = f(u,p,a(sub w), T(sub w)) where a(sub w) will contain the needed total temperature information. In this report, various methods of evaluating sensitivities with different dependent and independent variables to calibrate a 3-Wire hot-wire probe using a constant temperature anemometer (CTA) in subsonic/transonic flow regimes is presented. The advantage of using a(sub w) as the independent variable instead of total temperature, t(sub o), or overheat temperature parameter, tau, is that while running a calibration test it is not necessary to know the recovery factor, the coefficients in a wire resistance to temperature relationship for a given probe. It was deduced that the method employing the relationship E = f (u,p,a(sub w)) should result in the most accurate calibration of hot wire probes. Any other method would require additional measurements. Also this method will allow calibration and determination of accurate temperature fluctuation information even in atmospheric wind tunnels where there is no ability to obtain any temperature sensitivity information at present. This technique greatly simplifies the calibration process for hot-wires, provides the required calibration information needed in obtaining temperature fluctuations, and reduces both the tunnel run-time and the test matrix required to calibrate hotwires. Some of the results using the above techniques are presented in an appendix.

Impact of hot temperature on end-face geometry of LC/UPC connectors

NASA Astrophysics Data System (ADS)

Thongdaeng, Rutsuda; Worasucheepb, Duangrudee; Wangsan, Sathit; Chaichok, Wansan

2014-09-01

The fiber withdrawal of Group 4 (mated-thermal cycle) was observed up to 100 nm as in previous work1. We predict that this withdrawal is mainly caused by the impact of hot temperature (at 75ºC) based on GR-3262 thermal cycle test profile repeated 21 cycles over 7 days; and thus, it was studies here for the purpose of reducing test time. All connectors were separated into four groups: 1) unmated-stored at room temperature, 2) mated-stored at room temperature, 3) unmated-stored at hot temperature, and 4) mated-stored at hot temperature. The hot temperature test was performed on Groups 3 and 4 for 1 hour, while Groups 1 and 2 was left at room temperature. The sample size of each group is 28 LC/UPC connectors. Radius of curvature, fiber height and apex offset were measured before and after that 1 hour. The fiber withdrawal up to 100 nm is found in Group 4 (mated-hot temperature), but no changes are observed in Groups 1-3. These results confirm the impact of hot temperature on fiber height, same as the thermal cycle test in previous work1. Afterward, Group 1-4 were unmated at room temperature for 1 day, 1 week, and 1 month. No significant change in fiber height is found. On the contrary, when Group 1-4 were re-tested as being mated at hot temperature for 1 hour, the fiber withdrawal up to 100 nm is now found in Group 1-3. However, the additional withdrawal up to 50 nm is still observed in Group 4.

Removal of heavy metal ions from aqueous solutions using lignocellulosic fibers

Treesearch

Beom-Goo Lee; Roger M. Rowell

2004-01-01

Spruce, coconut coir, sugarcane bagasse, kenaf bast, kenaf core, and cotton were tested for their ability to remove copper, nickel and zinc ions from aqueous-solutions as a function of their lignin content. The fibers were analyzed for sugar and lignin content and extracted with diethyl ether, ethyl alcohol. hot water, or 1% sodium hydroxide. The order of lignin...

40 CFR 86.1343-88 - Calculations; particulate exhaust emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... cold-start test, grams. (3) PH = Mass particulate measured during the hot-start test, grams. (4) BHP-hr..., grams per test phase. (PH = Pmass for the hot-start test and PC = Pmass for the cold-start test. (2... Exhaust Test Procedures § 86.1343-88 Calculations; particulate exhaust emissions. (a) The final reported...

40 CFR 86.1343-88 - Calculations; particulate exhaust emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... cold-start test, grams. (3) PH = Mass particulate measured during the hot-start test, grams. (4) BHP-hr..., grams per test phase. (PH = Pmass for the hot-start test and PC = Pmass for the cold-start test. (2... Exhaust Test Procedures § 86.1343-88 Calculations; particulate exhaust emissions. (a) The final reported...

Modeling the Hot Ductility of AA6061 Aluminum Alloy After Severe Plastic Deformation

NASA Astrophysics Data System (ADS)

Khamei, A. A.; Dehghani, K.; Mahmudi, R.

2015-05-01

Solutionized AA6061 aluminum alloy was processed by equal-channel angular pressing followed by cold rolling. The hot ductility of the material was studied after severe plastic deformation. The hot tensile tests were carried out in the temperature range of 300-500°C and at the strain rates of 0.0005-0.01 s-1. Depending on the temperature and strain rate, the applied strain level exhibited significant effects on the hot ductility, strain-rate sensitivity, and activation energy. It can be suggested that the possible mechanism dominated the hot deformation during tensile testing is dynamic recovery and dislocation creep. Constitutive equations were developed to model the hot ductility of the severe plastic deformed AA6061 alloy.

HOT CELL BUILDING, TRA632. EAST END OF BUILDING. CAMERA FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. EAST END OF BUILDING. CAMERA FACING WEST. TRUCK ENCLOSURE (1986) TO THE LEFT, SMALL ADDITION IN ITS SHADOW IS ENCLOSURE OVER METAL PORT INTO HOT CELL NO. 1 (THE OLDEST HOT CELL). NOTE PERSONNEL LADDER AND PLATFORM AT LOFT LEVEL USED WHEN SERVICING AIR FILTERS AND VENTS OF CELL NO. 1. INL NEGATIVE NO. HD46-32-4. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

HOT CELL BUILDING, TRA632, INTERIOR. CONTEXTUAL VIEW OF HOT CELL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. CONTEXTUAL VIEW OF HOT CELL NO. 2 FROM STAIRWAY ALONG NORTH WALL. OBSERVATION WINDOW ALONG WEST SIDE BENEATH "CELL 2" SIGN. DOORWAY IN LEFT OF VIEW LEADS TO CELL 1 WORK AREA OR TO EXIT OUTDOORS TO NORTH. RADIATION DETECTION MONITOR TO RIGHT OF DOOR. CAMERA FACING SOUTHWEST. INL NEGATIVE NO. HD46-28-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Biological shielding test of hot cells with high active source 60Co (300 TBq)

NASA Astrophysics Data System (ADS)

Švrčula, P.; Zoul, D.; Zimina, M.; Petříčková, A.; Adamíková, T.; Schulc, M.; Srba, O.

2017-11-01

This article describes a method for testing of the efficiency of the biological shielding of the hot cell facility, which were constructed as a part of the project SUSEN. Ten hot cells and one semi-hot cell are present in the facility Radiochemistry II. The shielding is made from steel plates. In order to demonstrate sufficient efficiency of the biological shielding of the hot cells and a correspondence between measured and contractual values at selected points. The test was done using sealed high activity 60Co sources. The results are also used as a proof of the optimization of radiation protection for the workplace of this type. The results confirm significant optimization of radiation protection at the workplace. The dose received by a staff do not exceed one tens of annual limit during active service. Obtained results fulfill general requirements of radiation protection and will be used for further active service of hot cells facility.

Gas-Centered Swirl Coaxial Liquid Injector Evaluations

NASA Technical Reports Server (NTRS)

Cohn, A. K.; Strakey, P. A.; Talley, D. G.

2005-01-01

Development of Liquid Rocket Engines is expensive. Extensive testing at large scales usually required. In order to verify engine lifetime, large number of tests required. Limited Resources available for development. Sub-scale cold-flow and hot-fire testing is extremely cost effective. Could be a necessary (but not sufficient) condition for long engine lifetime. Reduces overall costs and risk of large scale testing. Goal: Determine knowledge that can be gained from sub-scale cold-flow and hot-fire evaluations of LRE injectors. Determine relationships between cold-flow and hot-fire data.

Influence of Hot-Etching Surface Treatment on Zirconia/Resin Shear Bond Strength

PubMed Central

Lv, Pin; Yang, Xin; Jiang, Ting

2015-01-01

This study was designed to evaluate the effect of hot-etching surface treatment on the shear bond strength between zirconia ceramics and two commercial resin cements. Ceramic cylinders (120 units; length: 2.5 mm; diameter: 4.7 mm) were randomly divided into 12 groups (n = 10) according to different surface treatments (blank control; airborne-particle-abrasion; hot-etching) and different resin cements (Panavia F2.0; Superbond C and B) and whether or not a thermal cycling fatigue test (5°–55° for 5000 cycles) was performed. Flat enamel surfaces, mounted in acrylic resin, were bonded to the zirconia discs (diameter: 4.7 mm). All specimens were subjected to shear bond strength testing using a universal testing machine with a crosshead speed of 1 mm/min. All data were statistically analyzed using one-way analysis of variance and multiple-comparison least significant difference tests (α = 0.05). Hot-etching treatment produced higher bond strengths than the other treatment with both resin cements. The shear bond strength of all groups significantly decreased after the thermal cycling test; except for the hot-etching group that was cemented with Panavia F2.0 (p < 0.05). Surface treatment of zirconia with hot-etching solution enhanced the surface roughness and bond strength between the zirconia and the resin cement. PMID:28793699

Space Shuttle Main Engine Low Pressure Oxidizer Turbo-Pump Inducer Dynamic Environment Characterization through Water Model and Hot-Fire Testing

NASA Technical Reports Server (NTRS)

Arellano, Patrick; Patton, Marc; Schwartz, Alan; Stanton, David

2006-01-01

The Low Pressure Oxidizer Turbopump (LPOTP) inducer on the Block II configuration Space Shuttle Main Engine (SSME) experienced blade leading edge ripples during hot firing. This undesirable condition led to a minor redesign of the inducer blades. This resulted in the need to evaluate the performance and the dynamic environment of the redesign, relative to the current configuration, as part of the design acceptance process. Sub-scale water model tests of the two inducer configurations were performed, with emphasis on the dynamic environment due to cavitation induced vibrations. Water model tests were performed over a wide range of inlet flow coefficient and pressure conditions, representative of the scaled operating envelope of the Block II SSME, both in flight and in ground hot-fire tests, including all power levels. The water test hardware, facility set-up, type and placement of instrumentation, the scope of the test program, specific test objectives, data evaluation process and water test results that characterize and compare the two SSME LPOTP inducers are discussed. In addition, dynamic characteristics of the two water models were compared to hot fire data from specially instrumented ground tests. In general, good agreement between the water model and hot fire data was found, which confirms the value of water model testing for dynamic characterization of rocket engine turbomachinery.

Computational Pollutant Environment Assessment from Propulsion-System Testing

NASA Technical Reports Server (NTRS)

Wang, Ten-See; McConnaughey, Paul; Chen, Yen-Sen; Warsi, Saif

1996-01-01

An asymptotic plume growth method based on a time-accurate three-dimensional computational fluid dynamics formulation has been developed to assess the exhaust-plume pollutant environment from a simulated RD-170 engine hot-fire test on the F1 Test Stand at Marshall Space Flight Center. Researchers have long known that rocket-engine hot firing has the potential for forming thermal nitric oxides, as well as producing carbon monoxide when hydrocarbon fuels are used. Because of the complex physics involved, most attempts to predict the pollutant emissions from ground-based engine testing have used simplified methods, which may grossly underpredict and/or overpredict the pollutant formations in a test environment. The objective of this work has been to develop a computational fluid dynamics-based methodology that replicates the underlying test-stand flow physics to accurately and efficiently assess pollutant emissions from ground-based rocket-engine testing. A nominal RD-170 engine hot-fire test was computed, and pertinent test-stand flow physics was captured. The predicted total emission rates compared reasonably well with those of the existing hydrocarbon engine hot-firing test data.

Monitoring environmental and related performance parameters for a Rankine-cycle turbine electric generator utilizing geothermal energy at the Gila Hot Springs, New Mexico

NASA Astrophysics Data System (ADS)

Starkey, A. H.; Icerman, L.

1984-08-01

The environmental effects associated with the operation of a privately owned Rankine-cycle turbogenerator unit using low temperature geothermal resources in the form of free-flowing hot springs to produce electricity in a remote, rural area were studied. The following conclusions pertain to the operation of the turbogenerator system: (1) the heat exchanger could not provide sufficient freon vapor at the required pressures to provide adequate thermal input to the turbine; (2) conversion or redesign of the condenser and return pump to function adequately represents a problem of unknown difficulty; (3) all pressure and heat transfer tests indicated that a custom designed heat exchanger built on-site would provide adequate vapor at pressures high enough to power a 10-kW (sub e) or perhaps larger generator; and (4) automated control systems are needed for the hot and cold water supplies and the freon return pump.

Radon-enriched hot spring water therapy for upper and lower respiratory tract inflammation.

PubMed

Passali, Desiderio; Gabelli, Giacomo; Passali, Giulio Cesare; Mösges, Ralph; Bellussi, Luisa Maria

2017-08-31

Background Radon-222-enriched hot spring therapy, which is characterized by a safe level of radioactivity, is used for the treatment of rheumatic disorders, and its efficacy has already been studied in several clinical trials. Radon-water inhalation therapy for the treatment of upper and lower airway inflammatory diseases is used in many hot springs centers. However, its application has not been reviewed to date. Methods We systematically searched the PubMed and Scopus databases for clinical trials published in the last 20 years in which objective parameters of upper and lower airway function had been tested before and after radon-enriched inhalation treatment. Results Four prospective studies were found: 1 asthma trial, 1 placebo-controlled chronic rhinosinusitis trial, 1 upper respiratory tract inflammation with nasal obstruction trial, and 1 case-control allergic rhinitis trial. Patients were treated with nasal inhalations of radon-enriched water for 12 to 28 days and were assessed at baseline and after therapy. After 2 weeks of treatment, nasal resistance decreased, flow increased, mucociliary clearance was enhanced, ciliated-to-muciparous cell ratio increased, and %FEV1 increased in asthmatic patients. Conclusion Radon-enriched inhalation therapy improves objective indicators of nasal function in allergic rhinitis and chronic rhinosinusitis, and causes relief of pulmonary obstruction in asthma.

Velocity fluctuations of a heavy particle interacting with a hot and cold gas: Applications to molecular ion traps

NASA Astrophysics Data System (ADS)

Vaca, Christian; Bruinsma, Robijn; Levine, Alex J.

2014-03-01

Understanding the stochastic motion of a heavy particle in a gas of lighter ones is a classic problem in statistical mechanics. Alkemade, MacDonald, and Van Kampen (AMvK) analyzed this problem in one dimension, computing the velocity distribution function of the heavy particle in a perturbation expansion using the ratio of mass of the light to the heavy particle as a small parameter. Novel tests of this theory are now being provided by modern molecular ion traps [arXiv:1310.5190]. In such experiments, the heavy molecular ion interacts with a cold gas used for sympathetic cooling and low density hot gasses that leak into the system. Thus, the heavy ion is maintained in a complex nonequilibrium state due to its interactions with the hot and cold gasses. In this talk, we present an extension of the AMvK model appropriate to these experiments. Using new analytic and computational techniques, we explore the time-dependent velocity distribution function of the molecular ion interacting with the gasses including higher order perturbative corrections necessary to discuss the case in which the ion's mass is not significantly larger than that of the other two species. Using this analysis we address the experimental observation of non-Gaussian velocity distributions of the heavy ions.

A brain-targeted ampakine compound protects against opioid-induced respiratory depression.

PubMed

Dai, Wei; Xiao, Dian; Gao, Xiang; Zhou, Xin-Bo; Fang, Tong-Yu; Yong, Zheng; Su, Rui-Bin

2017-08-15

The use of opioid drugs for pain relief can induce life-threatening respiratory depression. Although naloxone effectively counteracts opioid-induced respiratory depression, it diminishes the efficacy of analgesia. Our studies indicate that ampakines, in particular, a brain-targeted compound XD-8-17C, are able to reverse respiratory depression without affecting analgesia at relatively low doses. Mice and rats were subcutaneously or intravenously injected with the opioid agonist TH-030418 to induce moderate or severe respiratory depression. XD-8-17C was intravenously administered before or after TH-030418. The effect of XD-8-17C on opioid-induced respiratory depression was evaluated in terms of the opioid-induced acute death rate, arterial blood gas analysis and pulmonary function tests. In addition, the hot-plate test was conducted to investigate whether XD-8-17C influenced opioid-induced analgesia. Pre-treatment with XD-8-17C significantly reduced opioid-induced acute death, and increased the median lethal dose of TH-030418 by 4.7-fold. Blood gas analysis and pulmonary function tests demonstrated that post-treatment with XD-8-17C alleviated respiratory depression, as indicated by restoration of arterial blood gas (pO 2 , sO 2 , cK + ) and lung function parameters (respiratory frequency, minute ventilation) to the normal range. The hot-plate test showed that XD-8-17C had no impact on the antinociceptive efficacy of morphine. The ability of XD-8-17C to reverse opioid-induced respiratory depression has the potential to increase the safety and convenience of opioid treatment. These findings contribute to the discovery of novel therapeutic agents that protect against opioid-induced respiratory depression without loss of analgesia. Copyright © 2017 Elsevier B.V. All rights reserved.

NASA Conducts 2nd RS-25 Engine Hot Fire of 2018

NASA Image and Video Library

2018-02-01

A 365-second hot fire test on Feb. 1, 2018, at NASA’s Stennis Space Center in Mississippi marks the completion of “green run” testing, or flight certification, for all new RS-25 engine flight controllers slated for Exploration Mission-2, the first Space Launch System mission with astronauts on board. In addition to the flight controller, the Feb. 1 hot fire also marked the third test of a 3D printed pogo accumulator assembly for the RS-25 engine.

Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

NASA Astrophysics Data System (ADS)

Hohenberger, M.; Albert, F.; Palmer, N. E.; Lee, J. J.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K.; Stoeckl, C.

2014-11-01

In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic-a multichannel, hard x-ray spectrometer operating in the 20-500 keV range-has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ˜300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U Kβ). The detectors impulse response function was measured in situ on NIF short-pulse (˜90 ps) experiments, and in off-line tests.

HOT CELL BUILDING, TRA632, INTERIOR. DETAIL OF HOT CELL NO. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. DETAIL OF HOT CELL NO. 2 SHOWS MANIPULATION INSTRUMENTS AND SHIELDED OPERATING WINDOWS. PENETRATIONS FOR OPERATING INSTRUMENTS GO THROUGH SHIELDING ABOVE WINDOWS. CONDUIT FOR UTILITIES AND CONTROLS IS BEHIND METAL CABINET BELOW WINDOWS NEAR FLOOR. CAMERA FACES WEST. WARNING SIGN LIMITS FISSILE MATERIAL TO SPECIFIED NUMBER OF GRAMS OF URANIUM AND PLUTONIUM. INL NEGATIVE NO. HD46-28-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Evaluation of Contact Heat Transfer Coefficient and Phase Transformation during Hot Stamping of a Hat-Type Part

PubMed Central

Kim, Heung-Kyu; Lee, Seong Hyeon; Choi, Hyunjoo

2015-01-01

Using an inverse analysis technique, the heat transfer coefficient on the die-workpiece contact surface of a hot stamping process was evaluated as a power law function of contact pressure. This evaluation was to determine whether the heat transfer coefficient on the contact surface could be used for finite element analysis of the entire hot stamping process. By comparing results of the finite element analysis and experimental measurements of the phase transformation, an evaluation was performed to determine whether the obtained heat transfer coefficient function could provide reasonable finite element prediction for workpiece properties affected by the hot stamping process. PMID:28788046

Stellar by Day, Planetary by Night: Atmospheres of Ultra-Hot Jupiters

NASA Astrophysics Data System (ADS)

Hensley, Kerry

2018-06-01

Move over, hot Jupiters theres an even stranger kind of giant planet in the universe! Ultra-hot Jupiters are so strongly irradiated that the molecules in their atmospheres split apart. What does this mean for heat transport on these planets?Atmospheres of Exotic PlanetsA diagram showing the orbit of an ultra-hot Jupiter and the longitudes at which dissociation and recombination occur. [Bell Cowan 2018]Similar to hot Jupiters, ultra-hot Jupiters are gas giants with atmospheres dominated by molecular hydrogen. What makes them interesting is that their dayside atmospheres are so hot that the molecules dissociate into individual hydrogen atoms more like the atmospheres of stars than planets.Because of the intense stellar irradiation, there is also an extreme temperature difference between the day and night sides of these planets potentially more than 1,000 K! As the stellar irradiation increases, the dayside atmosphere becomes hotter and hotter and the temperature difference between the day and night sides increases.When hot atomic hydrogen is transported into cooler regions (by winds, for instance), it recombines to form H2 molecules and heats the gas, effectively transporting heat from one location to another. This is similar to how the condensation of water redistributes heat in Earths atmosphere but what effect does this phenomenon have on the atmospheres of ultra-hot Jupiters?Maps of atmospheric temperature of molecular hydrogen dissociation fraction for three wind speeds. Click to enlarge. [Bell Cowan 2018]Modeling Heat RedistributionTaylor Bell and Nicolas Cowan (McGill University) used an energy-balance model to estimate the effects of H2 dissociation and recombination on heat transport in ultra-hot Jupiter atmospheres. In particular, they explored the redistribution of heat and how it affects the resultant phase curve the curve that describes the combination of reflected and thermally emitted light from the planet, observed as a function of its phase angle.For reasonable eastward wind speeds, Bell and Cowan found that the recombination of atomic hydrogen shifts the peak of the phase curve in the eastward direction, with the shift becoming more pronounced with increasing eastward wind speed. Additionally, because heat is distributed more evenly across the planet, including this process decreases the amplitude of the phase variations.A Bright Future for Ultra-hot JupitersTheoretical phase curves for three wind speeds. Transits and eclipses have been neglected. [Bell Cowan 2018]While this simple model doesnt include potentially important effects such as the changing atmospheric opacity as a function of longitude or formation of clouds on the planets nightside, this result indicates that caution is required when interpreting phase curves of ultra-hot Jupiters. For example, neglecting recombination means assuming a lower heat transport efficiency, which will require artifically high wind speeds to match observed phase curves.Only a few ultra-hot Jupiters are currently known, but that will soon change. The Transiting Exoplanet Survey Satellite (TESS) mission, which is set to begin its first science observations on June 17, 2018, will search for exoplanets around bright stars, including nearby cool stars and more distant hot stars. The hot stars may play host to these exotic exoplanets, and upcoming observations of ultra-hot Jupiters like KELT-9b will put this theory of heat redistribution to the test.CitationTaylor J. Bell Nicolas B. Cowan 2018 ApJL 857 L20. doi:10.3847/2041-8213/aabcc8

Test method development to evaluate hot, humid air decontamination of materials contaminated with Bacillus anthracis ∆Sterne and B. thuringiensis Al Hakam spores.

PubMed

Buhr, T L; Young, A A; Minter, Z A; Wells, C M; McPherson, D C; Hooban, C L; Johnson, C A; Prokop, E J; Crigler, J R

2012-11-01

To develop test methods and evaluate the survival of Bacillus anthracis ∆Sterne and Bacillus thuringiensis Al Hakam spores after exposure to hot, humid air. Spores (>7 logs) of both strains were dried on six different test materials. Response surface methodology was employed to identify the limits of spore survival at optimal test combinations of temperature (60, 68, 77°C), relative humidity (60, 75, 90%) and time (1, 4, 7 days). No spores survived the harshest test run (77°C, 90% r.h., 7 days), while > 6·5 logs of spores survived the mildest test run (60°C, 60% r.h., 1 day). Spores of both strains inoculated on nylon webbing and polypropylene had greater survival rates at 68°C, 75% r.h., 4 days than spores on other materials. Electron microscopy showed no obvious physical damage to spores using hot, humid air, which contrasted with pH-adjusted bleach decontamination. Test methods were developed to show that hot, humid air effectively inactivates B. anthracis ∆Sterne and B. thuringiensis Al Hakam spores with similar kinetics. Hot, humid air is a potential alternative to conventional chemical decontamination. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Analysis of Flow Behavior of an Nb-Ti Microalloyed Steel During Hot Deformation

NASA Astrophysics Data System (ADS)

Mohebbi, Mohammad Sadegh; Parsa, Mohammad Habibi; Rezayat, Mohammad; Orovčík, L'ubomír

2018-03-01

The hot flow behavior of an Nb-Ti microalloyed steel is investigated through hot compression test at various strain rates and temperatures. By the combination of dynamic recovery (DRV) and dynamic recrystallization (DRX) models, a phenomenological constitutive model is developed to derive the flow stress. The predefined activation energy of Q = 270 kJ/mol and the exponent of n = 5 are successfully set to derive critical stress at the onset of DRX and saturation stress of DRV as functions of the Zener-Hollomon parameter by the classical hyperbolic sine equation. The remaining parameters of the constitutive model are determined by fitting them to the experiments. Through substitution of a normalized strain in the DRV model and considering the interconnections between dependent parameters, a new model is developed. It is shown that, despite its fewer parameters, this model is in good agreement with the experiments. Accurate analyses of flow data along with microstructural analyses indicate that the dissolution of NbC precipitates and its consequent solid solution strengthening and retardation of DRX are responsible for the distinguished behaviors in the two temperature ranges between T < 1100 °C and T ≥ 1100 °C. Nevertheless, it is shown that a single constitutive equation can still be employed for the present steel in the whole tested temperature ranges.

Influence of Ti on the Hot Ductility of High-manganese Austenitic Steels

NASA Astrophysics Data System (ADS)

Liu, Hongbo; Liu, Jianhua; Wu, Bowei; Su, Xiaofeng; Li, Shiqi; Ding, Hao

2017-07-01

The influence of Ti addition ( 0.10 wt%) on hot ductility of as-cast high-manganese austenitic steels has been examined over the temperature range 650-1,250 °C under a constant strain rate of 10-3 s-1 using Gleeble3500 thermal simulation testing machine. The fracture surfaces and particles precipitated at different tensile temperatures were characterized by means of scanning electron microscope and X-ray energy dispersive spectrometry (SEM-EDS). Hot ductility as a function of reduction curves shows that adding 0.10 wt% Ti made the ductility worse in the almost entire range of testing temperatures. The phases' equilibrium diagrams of precipitates in Ti-bearing high-Mn austenitic steel were calculated by the Thermo-Calc software. The calculation result shows that 0.1 wt% Ti addition would cause Ti(C,N) precipitated at 1,499 °C, which is higher than the liquidus temperature of high-Mn austenitic steel. It indicated that Ti(C,N) particles start forming in the liquid high-Mn austenitic steel. The SEM-EDS results show that Ti(C,N) and TiC particles could be found along the austenite grain boundaries or at triple junction, and they would accelerate the extension of the cracks along the grain boundaries.

Creep fatigue life prediction for engine hot section materials (isotropic)

NASA Technical Reports Server (NTRS)

Moreno, Vito; Nissley, David; Lin, Li-Sen Jim

1985-01-01

The first two years of a two-phase program aimed at improving the high temperature crack initiation life prediction technology for gas turbine hot section components are discussed. In Phase 1 (baseline) effort, low cycle fatigue (LCF) models, using a data base generated for a cast nickel base gas turbine hot section alloy (B1900+Hf), were evaluated for their ability to predict the crack initiation life for relevant creep-fatigue loading conditions and to define data required for determination of model constants. The variables included strain range and rate, mean strain, strain hold times and temperature. None of the models predicted all of the life trends within reasonable data requirements. A Cycle Damage Accumulation (CDA) was therefore developed which follows an exhaustion of material ductility approach. Material ductility is estimated based on observed similarities of deformation structure between fatigue, tensile and creep tests. The cycle damage function is based on total strain range, maximum stress and stress amplitude and includes both time independent and time dependent components. The CDA model accurately predicts all of the trends in creep-fatigue life with loading conditions. In addition, all of the CDA model constants are determinable from rapid cycle, fully reversed fatigue tests and monotonic tensile and/or creep data.

Technical Feasibility Evaluation on The Use of A Peltier Thermoelectric Module to Recover Automobile Exhaust Heat

NASA Astrophysics Data System (ADS)

Sugiartha, N.; Sastra Negara, P.

2018-01-01

A thermoelectric module composes of integrated p-n semiconductors as hot and cold side junctions and uses Seebeck effect between them to function as a thermoelectric generator (TEG) to directly convert heat into electrical power. Exhaust heat from engines as otherwise wasted to the atmosphere is one of the heat sources freely available to drive the TEG. This paper evaluates technical feasibility on the use of a Peltier thermoelectric module for energy recovery application of such kind of waste heat. An experimental apparatus has been setup to simulate real conditions of automobile engine exhaust piping system. It includes a square section aluminium ducting, an aluminium fin heat sink and a TEC1 12706 thermoelectric module. A heater and a cooling fan are employed to simulate hot exhaust gas and ambient air flows, respectively. Electrical loading is controlled by resistors. Dependent variables measured during the test are cold and hot side temperatures, open and loaded circuit output voltages and electrical current. The test results revealed a promising application of the Peltier thermoelectric module for the engine exhaust heat recovery, though the loaded output power produced and loaded output voltage are still far lower than the commercially thermoelectric module originally purposed for the TEG application.

HOT CELL BUILDING, TRA632, INTERIOR. HOT CELL NO. 1 (THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. HOT CELL NO. 1 (THE FIRST BUILT) IN LABORATORY 101. CAMERA FACES SOUTHEAST. SHIELDED OPERATING WINDOWS ARE ON LEFT (NORTH) SIDE. OBSERVATION WINDOW IS AT LEFT OF VIEW (ON WEST SIDE). PLASTIC COVERS SHROUD MASTER/SLAVE MANIPULATORS AT WINDOWS IN LEFT OF VIEW. NOTE MINERAL OIL RESERVOIR ABOVE "CELL 1" SIGN, INDICATING LEVEL OF THE FLUID INSIDE THE THICK WINDOWS. HOT CELL HAS BEVELED CORNER BECAUSE A SQUARED CORNER WOULD HAVE SUPPLIED UNNECESSARY SHIELDING. NOTE PUMICE BLOCK WALL AT LEFT OF VIEW. INL NEGATIVE NO. HD46-28-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

The effect of self-administered superficial local hot and cold application methods on pain, functional status and quality of life in primary knee osteoarthritis patients.

PubMed

Aciksoz, Semra; Akyuz, Aygul; Tunay, Servet

2017-12-01

To investigate the effect of the self-administered superficial local hot and cold applications on pain, and the functional status and the quality of life in primary knee osteoarthritis patients. Superficial local hot and cold application is used as a nonpharmacological method for the treatment of knee osteoarthritis. However, various guidelines for the management of knee osteoarthritis have conflicting recommendation for hot and cold therapy. A randomised clinical trial design. The sample consisted of patients (n = 96) who were diagnosed with primary knee osteoarthritis. During the application stage, patients were designated to the hot and cold application groups and administered hot and cold application twice a day for 3 weeks together with standard osteoarthritis treatment. The control group only used standard osteoarthritis treatment. The data were collected with a Descriptive Information Form, a Pain Scale, the WOMAC Osteoarthritis Index, the Nottingham Health Profile (NHP) and a Patient Satisfaction Evaluation Form. Outcome measures included pain intensity, functional status and quality of life. We found decreased primary measurement pain scores and improved functional status scores and quality of life scores after the application programme compared to the pre-application stage in both the hot and cold application groups. Once the application was completed, the pain scores, functional status scores and quality-of-life scores on the second measurements were found to be still statistically lower than the pre-application scores but higher than the first measurement ([p < .001, χ 2  = 48.000; p < .001, χ 2  = 34.000], [p < .001, χ 2  = 22.000; p = .001 χ 2 =14.000] and [p = .005, χ 2  = 16.000; p = .001, χ 2  = 12.500]). There was no difference in the perceived pain, functional status and quality of life between the pre-application, postapplication and 2 weeks postapplication periods of the individuals in three groups (p > .05). It was found that both hot and cold application resulted in a mild improvement in pain, functional status and quality of life, but this improvement was not sufficient to create a significant difference between the groups. This study contributes to the literature on hot and cold application methods as self-management strategies for patients with knee osteoarthritis. © 2017 John Wiley & Sons Ltd.

A reliability as an independent variable (RAIV) methodology for optimizing test planning for liquid rocket engines

NASA Astrophysics Data System (ADS)

Strunz, Richard; Herrmann, Jeffrey W.

2011-12-01

The hot fire test strategy for liquid rocket engines has always been a concern of space industry and agency alike because no recognized standard exists. Previous hot fire test plans focused on the verification of performance requirements but did not explicitly include reliability as a dimensioning variable. The stakeholders are, however, concerned about a hot fire test strategy that balances reliability, schedule, and affordability. A multiple criteria test planning model is presented that provides a framework to optimize the hot fire test strategy with respect to stakeholder concerns. The Staged Combustion Rocket Engine Demonstrator, a program of the European Space Agency, is used as example to provide the quantitative answer to the claim that a reduced thrust scale demonstrator is cost beneficial for a subsequent flight engine development. Scalability aspects of major subsystems are considered in the prior information definition inside the Bayesian framework. The model is also applied to assess the impact of an increase of the demonstrated reliability level on schedule and affordability.

Dual-mode operation of 2D material-base hot electron transistors

PubMed Central

Lan, Yann-Wen; Torres, Jr., Carlos M.; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R.; Lerner, Mitchell B.; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L.

2016-01-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications. PMID:27581550

Dual-mode operation of 2D material-base hot electron transistors.

PubMed

Lan, Yann-Wen; Torres, Carlos M; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R; Lerner, Mitchell B; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L

2016-09-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Long-term high-velocity oxidation and hot corrosion testing of several NiCrAl and FeCrAl base oxide dispersion strengthened alloys

NASA Technical Reports Server (NTRS)

Lowell, C. E.; Deadmore, D. L.; Whittenberger, J. D.

1982-01-01

Several oxide dispersion strengthened (ODS) alloys have been tested for cyclic, long-term, high gas-velocity resistance to oxidation at 1100 C and hot corrosion at 900 C. Both nominally Ni-16Cr-4Al and Fe-20Cr-4.5Al ODS alloys were subjected up to about 2500 cycles, where each cycle consisted of 1 hr in a hot, Mach 0.3 combusted gas stream followed by a 3-min quench in an ambient temperature, Mach 0.3 air blast. For comparison to existing technology, a coated superalloy was simultaneously tested. The ODS iron alloy exhibited clearly superior behavior, surviving 3800 oxidation and 2300 hot corrosion cycles essentially unscathed. While the ODS nickel alloys exhibited adequate oxidation resistance, the long-term hot corrosion resistance could be marginal, since the best life for such alloys under these conditions was only about 1100 cycles. However, the hot corrosion resistance of the ODS Ni-base alloys is excellent in comparison to that of traditional superalloys.

Hot-bench simulation of the active flexible wing wind-tunnel model

NASA Technical Reports Server (NTRS)

Buttrill, Carey S.; Houck, Jacob A.

1990-01-01

Two simulations, one batch and one real-time, of an aeroelastically-scaled wind-tunnel model were developed. The wind-tunnel model was a full-span, free-to-roll model of an advanced fighter concept. The batch simulation was used to generate and verify the real-time simulation and to test candidate control laws prior to implementation. The real-time simulation supported hot-bench testing of a digital controller, which was developed to actively control the elastic deformation of the wind-tunnel model. Time scaling was required for hot-bench testing. The wind-tunnel model, the mathematical models for the simulations, the techniques employed to reduce the hot-bench time-scale factors, and the verification procedures are described.

Menopausal Hot Flashes and Carotid Intima Media Thickness Among Midlife Women.

PubMed

Thurston, Rebecca C; Chang, Yuefang; Barinas-Mitchell, Emma; Jennings, J Richard; Landsittel, Doug P; Santoro, Nanette; von Känel, Roland; Matthews, Karen A

2016-12-01

There has been a longstanding interest in the role of menopause and its correlates in the development of cardiovascular disease (CVD) in women. Menopausal hot flashes are experienced by most midlife women; emerging data link hot flashes to CVD risk indicators. We tested whether hot flashes, measured via state-of-the-art physiologic methods, were associated with greater subclinical atherosclerosis as assessed by carotid ultrasound. We considered the role of CVD risk factors and estradiol concentrations in these associations. A total of 295 nonsmoking women free of clinical CVD underwent ambulatory physiologic hot flash assessments; a blood draw; and carotid ultrasound measurement of intima media thickness and plaque. Associations between hot flashes and subclinical atherosclerosis were tested in regression models controlling for CVD risk factors and estradiol. More frequent physiologic hot flashes were associated with higher carotid intima media thickness (for each additional hot flash: β [SE]=0.004 [0.001]; P=0.0001; reported hot flash: β [SE]=0.008 [0.002]; P=0.002, multivariable) and plaque (eg, for each additional hot flash, odds ratio [95% confidence interval] plaque index ≥2=1.07 [1.003-1.14]; P=0.04, relative to no plaque, multivariable] among women reporting daily hot flashes; associations were not accounted for by CVD risk factors or by estradiol. Among women reporting hot flashes, hot flashes accounted for more variance in intima media thickness than most CVD risk factors. Among women reporting daily hot flashes, frequent hot flashes may provide information about a woman's vascular status beyond standard CVD risk factors and estradiol. Frequent hot flashes may mark a vulnerable vascular phenotype among midlife women. © 2016 American Heart Association, Inc.

Menopausal Hot Flashes and Carotid Intima Media Thickness among Midlife Women

PubMed Central

Thurston, Rebecca C.; Chang, Yuefang; Barinas-Mitchell, Emma; Jennings, J. Richard; Landsittel, Doug P.; Santoro, Nanette; von Känel, Roland; Matthews, Karen A.

2016-01-01

Background and Purpose There has been a longstanding interest in the role of menopause and its correlates in the development of cardiovascular disease (CVD) in women. Menopausal hot flashes are experienced by most midlife women; emerging data link hot flashes to CVD risk indicators. We tested whether hot flashes, measured via state-of-the-art physiologic methods, were associated with greater subclinical atherosclerosis as assessed by carotid ultrasound. We considered the role of CVD risk factors and estradiol concentrations in these associations. Methods 295 nonsmoking women free of clinical CVD underwent ambulatory physiologic hot flash assessments; a blood draw; and carotid ultrasound measurement of IMT and plaque. Associations between hot flashes and subclinical atherosclerosis were tested in regression models controlling for CVD risk factors and estradiol. Results More frequent physiologic hot flashes were associated with higher carotid intima media thickness [IMT; for each additional hot flash: beta (standard error)=.004(.001), p=.0001; reported hot flash: beta (standard error)=.008(.002), p=.002, multivariable] and plaque [e.g., for each additional hot flash, odds ratio (95% confidence interval) plaque index ≥2=1.07(1.003–1.14, p=.04), relative to no plaque, multivariable] among women reporting daily hot flashes; associations were not accounted for by CVD risk factors or by estradiol. Among women reporting hot flashes, hot flashes accounted for more variance in IMT than most CVD risk factors. Conclusions Among women reporting daily hot flashes, frequent hot flashes may provide information about a woman’s vascular status beyond standard CVD risk factors and estradiol. Frequent hot flashes may mark a vulnerable vascular phenotype among midlife women. PMID:27834746

Largo hot water system long range thermal performance test report, addendum

NASA Technical Reports Server (NTRS)

1978-01-01

The test procedure used and the test results obtained during the long range thermal performance tests of the LARGO Solar Hot Water System under natural environmental conditions are presented. Objectives of these tests were to determine the amount of energy collected, the amount of power required for system operation, system efficiency, temperature distribution, and system performance degradation.

Hot piston ring tests

NASA Technical Reports Server (NTRS)

Allen, David J.; Tomazic, William A.

1987-01-01

As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

Increased capability gas generator for Space Shuttle APU. Development/hot restart test report

NASA Technical Reports Server (NTRS)

1980-01-01

The design, fabrication, and testing of an increased capability gas generator for use in space shuttles are described. Results show an unlimited hot restart capability in the range of feed pressures from 400 psi to 80 psi. Effects of vacuum on hot restart were not addressed, and only beginning-of-life bed conditions were tested. No starts with bubbles were performed. A minimum expected life of 35 hours or more is projected, and the design will maintain a surface temperature of 350 F or more.

40 CFR 86.135-90 - Dynamometer procedure.

Code of Federal Regulations, 2012 CFR

2012-07-01

... startup and operation over the first 505 seconds of the driving schedule complete the hot start test. The... 505 seconds of the driving schedule complete the hot start test. The exhaust emissions are diluted... over the prescribed driving schedule may be performed at test point, provided an emission sample is not...

40 CFR 86.135-90 - Dynamometer procedure.

Code of Federal Regulations, 2013 CFR

2013-07-01

... startup and operation over the first 505 seconds of the driving schedule complete the hot start test. The... 505 seconds of the driving schedule complete the hot start test. The exhaust emissions are diluted... over the prescribed driving schedule may be performed at test point, provided an emission sample is not...

[Clinical Trial of Treatment of Cervicogenic Scapulohumeral Periarthritis by Red-hot Needle Therapy Combined with Cupping].

PubMed

Yuan, Tao; Wang, Fen

2015-10-01

To observe the therapeutic effect of red-hot needle therapy combined with cupping for cervicogenic periarthritis of shoulder. Forty-two cases of cervicogenic periarthritis of shoulder were randomized into red-hot needle group and routine acupuncture group (n = 21). For patients of the routine acupuncture group, the filiform needles were applied to Tianzhu (BL 10), Jianjing (GB 21), Jianzhongshu (SI 15), Jianzhen (SI 9), Jianliao (TE 14), Jianyu (LI 15), Jianqian, Tianzong (SI 11) and Ashi-points on the affected side, followed by conducting cupping at the anterior and posterior regions of the affected shoulder, SI 11, GB 21 and SI 15. For patients of the red-hot needle group, the Ashi-points on the affected shoulder were punctured with cauterized filiform needles, following by performing cupping. The treatment was performed once daily and once every other day respectively for two weeks. The shoulder motor function was assessed according to the adjusted Constant-Murley test. After the treatment, the integrated scores of shoulder pain, shoulder-joint activities in daily living and shoulder-joint motion range were significantly increased in both groups compared with pre-treatment in the same one group (P < 0.05) and obviously higher in the red-hot needle group than in the routine acupuncture group (P < 0.05). Of the two 21 cases of shoulder periarthritis patients in the routine acupuncture and red-hot needle groups, 4 and 8 were cured, 14 and 12 experienced improvement, 3 and 1 was invalid, with the effective rates being 85.71% and 95.24%, respectively. The therapeutic effect of the red-hot needle therapy was significantly superior to that of the routine acupuncture (P < 0.05). The red-hot needle therapy combined with cupping is effective in relieving cervicogenic shoulder periarthritis and is remarkably superior to routine acupuncture combined with cupping in improving shoulder periarthritis patients' symptoms.

Laboratory evaluation of thermal protective clothing performance upon hot liquid splash.

PubMed

Gholamreza, Farzan; Song, Guowen

2013-07-01

This study provides an understanding of heat and mass transfer through materials exposed to hot liquid splash, a relatively unexplored hazard in the safety clothing industry. Selected fabrics and layered systems were exposed to three hot liquids to study the effects of hot liquids and configuration. To explore the energy transfer mechanisms, a modified apparatus (based on ASTM F 2701-08) was developed to assess the protection performance provided by a fabric when exposed to a hot liquid. The modified test method allows measurement of the energy absorbed by the sensor, and with the use of a skin model, the time required to produce a second-degree burn injury was predicted. The preliminary testing demonstrated that mass transfer of the hot liquid through the fabric is the main factor contributing to burn injury. Key factors that determine the level of protection that a fabric system provides are summarized.

Chemical processes involved in the initiation of hot corrosion of B-1900 and NASA-TRW VIA. [high temperature tests of superalloys

NASA Technical Reports Server (NTRS)

Fryburg, G. C.; Kohl, F. J.; Stearns, C. A.

1979-01-01

Sodium surface-induced hot corrosion of B-1900 and NASA-TRW VIA alloys at 900 C has been studied, with special attention to the chemical reactions during and immediately after the induction period. Thermogravimetric tests were run and data were obtained by chemical analysis of water soluble metal salts and of residual sulfate. Surface analyses of hot corroded samples were obtained by spectroscopic techniques (ESCA). A chemical mechanism for elucidating Na2SO4-induced hot corrosion is proposed indicating that hot corrosion is initiated by basic fluxing of the protective Al2O3 scale. The sequential, catastrophic corrosion results from molybdenum content. The self-sustaining feature is a consequence of the cyclic nature of the acidic fluxing. It is believed that the mechanism is applicable not only to laboratory results, but also to the practical problem of hot corrosion encountered in gas turbine engines.

Parts, Materials, and Processes Control Program for Expendable Launch Vehicles

DTIC Science & Technology

2015-07-31

burn-in, electrical tests (DWV, room and hot IR, partial discharge when in corona region); perform DPA with SEM/EDX analysis of dielectric...life test; x-ray and vicinal illumination inspection; electrical tests (DWV, room and hot IR, partial discharge when in corona region) Termination...defects; proper voltage derating. Partial discharge testing, corona inception testing up to 60% of rated voltage; CSAM screening; voltage burn

Investigation of Cool and Hot Executive Function in ODD/CD Independently of ADHD

ERIC Educational Resources Information Center

Hobson, Christopher W.; Scott, Stephen; Rubia, Katya

2011-01-01

Background: Children with oppositional defiant disorder/conduct disorder (ODD/CD) have shown deficits in "cool" abstract-cognitive, and "hot" reward-related executive function (EF) tasks. However, it is currently unclear to what extent ODD/CD is associated with neuropsychological deficits, independently of attention deficit hyperactivity disorder…

10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

Code of Federal Regulations, 2010 CFR

2010-01-01

... efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water... PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply Boilers... of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial...

46 CFR 63.25-3 - Electric hot water supply boilers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Electric hot water supply boilers. 63.25-3 Section 63.25... water supply boilers. (a) Electric hot water supply boilers that have a capacity not greater than 454... section except the periodic testing required by paragraph (j) of this section. Electric hot water supply...

Hot and Cool Executive Function and Its Relation to Theory of Mind in Children with and without Autism Spectrum Disorder

ERIC Educational Resources Information Center

Kouklari, Evangelia-Chrysanthi; Thompson, Trevor; Monks, Claire P.; Tsermentseli, Stella

2017-01-01

Previous research has clearly demonstrated that autism spectrum disorder (ASD) involves deficits in multiple neuropsychological functions, such as executive function (EF) and theory of mind (ToM). A conceptual distinction is commonly made between cool and hot EF. In ASD, continued attention has been paid to the cool areas of executive dysfunction.…

Hot-Fire Test Results of an Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged-Combustion Integrated Test Article

NASA Technical Reports Server (NTRS)

Hulka, J. R.; Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.

2016-01-01

As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. For the thrust chamber assembly of the test article, several configurations of new main injectors, using relatively conventional gas-centered swirl coaxial injector elements, were designed and fabricated. The design and fabrication of these main injectors are described in a companion paper at this JANNAF meeting. New ablative combustion chambers were fabricated based on hardware previously used at NASA for testing at similar size and pressure. An existing oxygen/RP-1 oxidizer-rich subscale preburner injector from a previous NASA-funded program, along with existing and new inter-connecting hot gas duct hardware, were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. Results from independent hot-fire tests of the preburner injector in a combustion chamber with a sonic throat are described in companion papers at this JANNAF conference. The resulting integrated test article - which includes the preburner, inter-connecting hot gas duct, main injector, and ablative combustion chamber - was assembled at Test Stand 116 at the East Test Area of the NASA Marshall Space Flight Center. The test article was well instrumented with static and dynamic pressure, temperature, and acceleration sensors to allow the collected data to be used for combustion analysis model development. Hot-fire testing was conducted with main combustion chamber pressures ranging from 1400 to 2100 psia, and main combustion chamber mixture ratios ranging from 2.4 to 2.9. Different levels of fuel film cooling injected from the injector face were examined ranging from none to about 12% of the total fuel flow. This paper presents the hot-fire test results of the integrated test article. Combustion performance, stability, thermal, and compatibility characteristics of both the preburner and the thrust chamber are described. Another companion paper at this JANNAF meeting includes additional and more detailed test data regarding the combustion dynamics and stability characteristics.

Constitutive Model for Hot Deformation of the Cu-Zr-Ce Alloy

NASA Astrophysics Data System (ADS)

Zhang, Yi; Sun, Huili; Volinsky, Alex A.; Wang, Bingjie; Tian, Baohong; Liu, Yong; Song, Kexing

2018-02-01

Hot compressive deformation behavior of the Cu-Zr-Ce alloy has been investigated according to the hot deformation tests in the 550-900 °C temperature range and 0.001-10 s-1 strain rate range. Based on the true stress-true strain curves, the flow stress behavior of the Cu-Zr-Ce alloy was investigated. Microstructure evolution was observed by optical microscopy. Based on the experimental results, a constitutive equation, which reflects the relationships between the stress, strain, strain rate and temperature, has been established. Material constants n, α, Q and ln A were calculated as functions of strain. The equation predicting the flow stress combined with these materials constants has been proposed. The predicted stress is consistent with experimental stress, indicating that developed constitutive equation can adequately predict the flow stress of the Cu-Zr-Ce alloy. Dynamic recrystallization critical strain was determined using the work hardening rate method. According to the dynamic material model, the processing maps for the Cu-Zr and Cu-Zr-Ce alloy were obtained at 0.4 and 0.5 strain. Based on the processing maps and microstructure observations, the optimal processing parameters for the two alloys were determined, and it was found that the addition of Ce can promote the hot workability of the Cu-Zr alloy.

A computational tool to predict the evolutionarily conserved protein-protein interaction hot-spot residues from the structure of the unbound protein.

PubMed

Agrawal, Neeraj J; Helk, Bernhard; Trout, Bernhardt L

2014-01-21

Identifying hot-spot residues - residues that are critical to protein-protein binding - can help to elucidate a protein's function and assist in designing therapeutic molecules to target those residues. We present a novel computational tool, termed spatial-interaction-map (SIM), to predict the hot-spot residues of an evolutionarily conserved protein-protein interaction from the structure of an unbound protein alone. SIM can predict the protein hot-spot residues with an accuracy of 36-57%. Thus, the SIM tool can be used to predict the yet unknown hot-spot residues for many proteins for which the structure of the protein-protein complexes are not available, thereby providing a clue to their functions and an opportunity to design therapeutic molecules to target these proteins. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

16 CFR 1505.51 - Hot surfaces.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

16 CFR 1505.51 - Hot surfaces.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

16 CFR 1505.51 - Hot surfaces.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

Spring 2014 Internship Diffuser Data Analysis

NASA Technical Reports Server (NTRS)

Laigaie, Robert T.; Ryan, Harry M.

2014-01-01

J-2X engine testing on the A-2 test stand at the NASA John C. Stennis Space Center (SSC) has recently concluded. As part of that test campaign, the engine was operated at lower power levels in support of expanding the use of J-2X to other missions. However, the A-2 diffuser was not designed for engine testing at the proposed low power levels. To evaluate the risk of damage to the diffuser, computer simulations were created of the rocket engine exhaust plume inside the 50ft long, water-cooled, altitude-simulating diffuser. The simulations predicted that low power level testing would cause the plume to oscillate in the lower sections of the diffuser. This can possibly cause excessive vibrations, stress, and heat transfer from the plume to the diffuser walls. To understand and assess the performance of the diffuser during low power level engine testing, nine accelerometers and four strain gages were installed around the outer surface of the diffuser. The added instrumentation also allowed for the verification of the rocket exhaust plume computational model. Prior to engine hot-fire testing, a diffuser water-flow test was conducted to verify the proper operation of the newly installed instrumentation. Subsequently, two J-2X engine hot-fire tests were completed. Hot-Fire Test 1 was 11.5 seconds in duration, and accelerometer and strain data verified that the rocket engine plume oscillated in the lower sections of the diffuser. The accelerometers showed very different results dependent upon location. The diffuser consists of four sections, with Section 1 being closest to the engine nozzle and Section 4 being farthest from the engine nozzle. Section 1 accelerometers showed increased amplitudes at startup and shutdown, but low amplitudes while the diffuser was started. Section 3 accelerometers showed the opposite results with near zero G amplitudes prior to and after diffuser start and peak amplitudes to +/- 100G while the diffuser was started. Hot-Fire Test 1 strain gages showed different data dependent on section. Section 1 strains were small, and were in the range of 50 to 150 microstrain, which would result in stresses from 1.45 to 4.35 ksi. The yield stress of the material, A-285 Grade C Steel, is 29.7 ksi. Section 4 strain gages showed much higher values with strains peaking at 1600 microstrain. This strain corresponds to a stress of 46.41 ksi, which is in excess of the yield stress, but below the ultimate stress of 55 to 75 ksi. The decreased accelerations and strain in Section 1, and the increased accelerations and strain in Sections 3 and 4 verified the computer simulation prediction of increased plume oscillations in the lower sections of the diffuser. Hot-Fire Test 2 ran for a duration of 125 seconds. The engine operated at a slightly higher power level than Hot-Fire Test 1 for the initial 35 seconds of the test. After 35 seconds the power level was lowered to Hot-Fire Test 1 levels. The acceleration and strain data for Hot-Fire Test 2 was similar during the initial part of the test. However, just prior to the engine being lowered to the Hot-Fire Test 1 power level, the strain gage data in Section 4 showed a large decrease to strains near zero microstrain from their peak at 1500 microstrain. Future work includes further strain and acceleration data analysis and evaluation.

Hot-crack test for aluminium alloys welds using TIG process

NASA Astrophysics Data System (ADS)

Niel, A.; Deschaux-Beaume, F.; Bordreuil, C.; Fras, G.

2010-06-01

Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

Effects of surface chemistry on hot corrosion life

NASA Technical Reports Server (NTRS)

Fryxell, R. E.; Gupta, B. K.

1984-01-01

Hot corrosion life prediction methodology based on a combination of laboratory test data and field service turbine components, which show evidence of hot corrosion, were examined. Components were evaluated by optical metallography, scanning electron microscopy (SEM), and electron micropulse (EMP) examination.

Hot gas ingestion test results of a two-poster vectored thrust concept with flow visualization in the NASA Lewis 9- x 15-foot low speed wind tunnel

NASA Technical Reports Server (NTRS)

Johns, Albert L.; Neiner, George; Bencic, Timothy J.; Flood, Joseph D.; Amuedo, Kurt C.; Strock, Thomas W.

1990-01-01

A 9.2 percent scale Short Takeoff and Vertical Landing (STOVL) hot gas ingestion model was designed and built by McDonnell Douglas Corporation (MCAIR) and tested in the Lewis Research Center 9 x 15 foot Low Speed Wind Tunnel (LSWT). Hot gas ingestion, the entrainment of heated engine exhaust into the inlet flow field, is a key development issure for advanced short takeoff and vertical landing aircraft. Flow visualization from the Phase 1 test program, which evaluated the hot ingestion phenomena and control techniques, is covered. The Phase 2 test program evaluated the hot gas ingestion phenomena at higher temperatures and used a laser sheet to investigate the flow field. Hot gas ingestion levels were measured for the several forward nozzle splay configurations and with flow control/life improvement devices (LIDs) which reduced the hot gas ingestion. The model support system had four degrees of freedom - pitch, roll, yaw, and vertical height variation. The model support system also provided heated high-pressure air for nozzle flow and a suction system exhaust for inlet flow. The test was conducted at full scale nozzle pressure ratios and inlet Mach numbers. Test and data analysis results from Phase 2 and flow visualization from both Phase 1 and 2 are documented. A description of the model and facility modifications is also provided. Headwind velocity was varied from 10 to 23 kn. Results are presented over a range of nozzle pressure ratios at a 10 kn headwind velocity. The Phase 2 program was conducted at exhaust nozzle temperatures up to 1460 R and utilized a sheet laser system for flow visualization of the model flow field in and out of ground effects. The results reported are for nozzle exhaust temperatures up to 1160 R. These results will contain the compressor face pressure and temperature distortions, the total pressure recovery, the inlet temperature rise, and the environmental effects of the hot gas. The environmental effects include the ground plane contours, the model airframe heating, and the location of the ground flow separation.

VPS GRCop-84 Liner Development Efforts

NASA Technical Reports Server (NTRS)

Elam, Sandra K.; Holmes, Richard; McKechnie, Tim; Hickman, Robert; Pickens, Tim

2003-01-01

For the past several years, NASA's Marshall Space Flight Center (MSFC) has been working with Plasma Processes, Inc. (PPI) to fabricate combustion chamber liners using the Vacuum Plasma Spray (VPS) process. Multiple liners of a variety of shapes and sizes have been created. Each liner has been fabricated with GRCop-84 (a copper alloy with chromium and niobium) and a functional gradient coating (FGC) on the hot wall. While the VPS process offers versatility and a reduced fabrication schedule, the material system created with VPS allows the liners to operate at higher temperatures, with maximum blanch resistance and improved cycle life. A subscal unit (5K lbf thrust class) is being cycle tested in a LOX/Hydrogen thrust chamber assembly at MSFC. To date, over 75 hot-fire tests have been accumulated on this article. Tests include conditions normally detrimental to conventional materials, yet the VPS GRCop-84 liner has yet to show any signs of degradation. A larger chamber (15K lbf thrust class) has also been fabricated and is being prepared for hot-fire testing at MSFC near the end of 2003. Linear liners have been successfully created to further demonstrate the versatility of the process. Finally, scale up issues for the VPS process are being tackled with efforts to fabricate a full size, engine class liner. Specifically, a liner for the SSME's Main Combustion Chamber (MCC) has recently been attempted. The SSME size was chosen for convenience, since its design was readily available and its size was sufficient to tackle specific issues. Efforts to fabricate these large liners have already provided valuable lessons for using this process for engine programs. The material quality for these large units is being evaluated with destructive analysis and these results will be available by the end of 2003.

Dynamic Leading-Edge Stagnation Point Determination Utilizing an Array of Hot-Film Sensors with Unknown Calibration

NASA Technical Reports Server (NTRS)

Ellsworth, Joel C.

2017-01-01

During flight-testing of the National Aeronautics and Space Administration (NASA) Gulfstream III (G-III) airplane (Gulfstream Aerospace Corporation, Savannah, Georgia) SubsoniC Research Aircraft Testbed (SCRAT) between March 2013 and April 2015 it became evident that the sensor array used for stagnation point detection was not functioning as expected. The stagnation point detection system is a self calibrating hot-film array; the calibration was unknown and varied between flights, however, the channel with the lowest power consumption was expected to correspond with the point of least surface shear. While individual channels showed the expected behavior for the hot-film sensors, more often than not the lowest power consumption occurred at a single sensor (despite in-flight maneuvering) in the array located far from the expected stagnation point. An algorithm was developed to process the available system output and determine the stagnation point location. After multiple updates and refinements, the final algorithm was not sensitive to the failure of a single sensor in the array, but adjacent failures beneath the stagnation point crippled the algorithm.

Recombination or mutational hot spots in human mtDNA?

PubMed

Innan, Hideki; Nordborg, Magnus

2002-07-01

Awadalla, Eyre-Walker, and Maynard Smith (1999) recently argued that there might be recombination in human mitochondrial DNA (mtDNA). Their claim was based on their observation of decaying linkage disequilibrium (LD) as a function of physical distance. Their study was much criticized, and follow-up studies have failed to find any evidence for recombination. We argue that the criticisms levied, even if correct, could not possibly explain the findings of Awadalla, Eyre-Walker, and Maynard Smith (1999). Nonetheless, the test proposed by Awadalla, Eyre-Walker, and Maynard Smith (1999 ) is not robust because recombination is not the only explanation for decay of LD. We show that such a pattern can be caused by mutational hot spots as well. However, a closer look at the data suggests that the pattern observed was not caused by mutational hot spots but rather by chance. Thus, there appears to be no evidence for recombination in the mtDNA polymorphism data. In conclusion, we discuss the possibility of detecting recombination in mtDNA and the implications of its existence.

Space shuttle development Motor No. 9 (DM-9), volume 1

NASA Technical Reports Server (NTRS)

Garecht, Diane M.

1990-01-01

The results obtained during the December 23, 1987 static firing of the DM-9 test article are presented. The DM-9 full-scale static test article employed redesigned solid rocket motor (RSRM) field joint capture feature hardware with J-seal insulation configuration, and nozzle-to-case joint radial bolt design with bonded insulation configuration. The nozzle incorporated RSRM components, including a thicker cowl with involuted outer boot ring. The nozzle employed redundant and verifiable seals in all five joints, and room temperature vulcanization backfill in three joints. With very few exceptions, the DM-9 test article was flight configuration. The test was conducted under extreme weather conditions: temperature of 25 F and wind at 15 to 20 mph. Ballistics performance values were within specification requirements. The RSRM field joint (J-seal) insulation configuration functioned as predicted with no indication of hot gases reaching the capture feature O-rings. There was a blowhole in the polysulfide adhesive in the nozzle-to-case joint, but no evidence of hot gases past the wiper O-ring. Nozzle design changes appeared to perform nominally, with the exception of the outer boot ring, which suffered partial structural breakup late in the test. Field joint heaters maintained the controlling resistance temperature device temperature within the specified requirements during heater operation. The thrust vector control system operated properly. The redesigned water deluge system, temperature conditioning equipment, and other test support equipment performed as planned.

Discovery of multiple interacting partners of gankyrin, a proteasomal chaperone and an oncoprotein--evidence for a common hot spot site at the interface and its functional relevance.

PubMed

Nanaware, Padma P; Ramteke, Manoj P; Somavarapu, Arun K; Venkatraman, Prasanna

2014-07-01

Gankyrin, a non-ATPase component of the proteasome and a chaperone of proteasome assembly, is also an oncoprotein. Gankyrin regulates a variety of oncogenic signaling pathways in cancer cells and accelerates degradation of tumor suppressor proteins p53 and Rb. Therefore gankyrin may be a unique hub integrating signaling networks with the degradation pathway. To identify new interactions that may be crucial in consolidating its role as an oncogenic hub, crystal structure of gankyrin-proteasome ATPase complex was used to predict novel interacting partners. EEVD, a four amino acid linear sequence seems a hot spot site at this interface. By searching for EEVD in exposed regions of human proteins in PDB database, we predicted 34 novel interactions. Eight proteins were tested and seven of them were found to interact with gankyrin. Affinity of four interactions is high enough for endogenous detection. Others require gankyrin overexpression in HEK 293 cells or occur endogenously in breast cancer cell line- MDA-MB-435, reflecting lower affinity or presence of a deregulated network. Mutagenesis and peptide inhibition confirm that EEVD is the common hot spot site at these interfaces and therefore a potential polypharmacological drug target. In MDA-MB-231 cells in which the endogenous CLIC1 is silenced, trans-expression of Wt protein (CLIC1_EEVD) and not the hot spot site mutant (CLIC1_AAVA) resulted in significant rescue of the migratory potential. Our approach can be extended to identify novel functionally relevant protein-protein interactions, in expansion of oncogenic networks and in identifying potential therapeutic targets. © 2013 Wiley Periodicals, Inc.

Hypnosis for hot flashes among postmenopausal women study: A study protocol of an ongoing randomized clinical trial

PubMed Central

2011-01-01

Background Hot flashes are a highly prevalent problem associated with menopause and breast cancer treatments. The recent findings from the Women's Health Initiative have important implications for the significance of a non-hormonal, mind-body intervention for hot flashes in breast cancer survivors. Women who take hormone therapy long-term may have a 1.2 to 2.0 fold increased risk of developing breast cancer. In addition, it is now known that hormone therapy with estrogen and progestin is associated with increased risk of cardiovascular disease and stroke. Currently there are limited options to hormone replacement therapy as non-hormonal pharmacological agents are associated with only modest activity and many adverse side effects. Because of this there is a need for more alternative, non-hormonal therapies. Hypnosis is a mind-body intervention that has been shown to reduce self-reported hot flashes by up to 68% among breast cancer survivors, however, the use of hypnosis for hot flashes among post-menopausal women has not been adequately explored and the efficacy of hypnosis in reducing physiologically measured hot flashes has not yet been determined. Methods/design A sample of 180 post-menopausal women will be randomly assigned to either a 5-session Hypnosis Intervention or 5-session structured-attention control with 12 week follow-up. The present study will compare hypnosis to a structured-attention control in reducing hot flashes (perceived and physiologically monitored) in post-menopausal women in a randomized clinical trial. Outcomes will be hot flashes (self-report daily diaries; physiological monitoring; Hot Flash Related Daily Interference Scale), anxiety (State-Trait Anxiety Inventory; Hospital Anxiety and Depression Scale (HADS); anxiety visual analog scale (VAS rating); depression (Center for Epidemiologic Studies Depression Scale), sexual functioning (Sexual Activity Questionnaire), sleep quality (Pittsburgh Sleep Quality Index) and cortisol. Discussion This study will be the first full scale test of hypnosis for hot flashes; one of the first studies to examine both perceived impact and physiologically measured impact of a mind-body intervention for hot flashes using state-of-the-art 24 hour ambulatory physiological monitoring; the first study to examine the effect of hypnosis for hot flashes on cortisol; and the first investigation of the role of cognitive expectancies in treatment of hot flashes in comparison to a Structured-Attention Control. Trial Registration This clinical trial has been registered with ClinicalTrials.gov, a service of the U.S. National Institutes of Health, ClinicalTrials.gov Identifier: NCT01293695. PMID:21989181

Interaction of the Left Dorsolateral Prefrontal Cortex (l-DLPFC) and Right Orbitofrontal Cortex (OFC) in Hot and Cold Executive Functions: Evidence from Transcranial Direct Current Stimulation (tDCS).

PubMed

Nejati, Vahid; Salehinejad, Mohammad Ali; Nitsche, Michael A

2018-01-15

An organizing principle which has recently emerged proposes that executive functions (EF) can be divided into cognitive (cold) and affective/reward-related (hot) processes related to the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) respectively. A controversial question is whether cold and hot EF are functionally and structurally independent or not. This study investigated how the left DLPFC (l-DLPFC) and right OFC (r-OFC) interact in hot and cold EF using transcranial direct current stimulation (tDCS). Twenty-four healthy male subjects received anodal, cathodal and sham tDCS (20 min, 1.5 mA) over the l-DLPFC (F3) and r-OFC (Fp2) with a 72-h interval between each stimulation condition. After five minutes of stimulation, participants underwent a series of cold and hot EF tasks including the Go/No-Go and Tower of Hanoi (TOH) as measures of cold EF and the BART and temporal discounting tasks as measures of hot EF. Inhibitory control mostly benefited from anodal l-DLPFC/cathodal r-OFC tDCS. Planning and problem solving were more prominently affected by anodal l-DLPFC/cathodal r-OFC stimulation, although the reversed electrode position with the anode positioned over the r-OFC also affected some aspects of task performance. Risk-taking behavior and risky decision-making decreased under both anodal l-DLPFC/cathodal r-OFC and anodal r-OFC/cathodal l-DLPFC tDCS. Cold EF rely on DLPFC activation while hot EF rely on both, DLPFC and OFC activation. Results suggest that EF are placed on continuum with lateral and mesial prefrontal areas contributing to cold and hot aspects respectively. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

History of Childhood Maltreatment and College Academic Outcomes: Indirect Effects of Hot Execution Function

PubMed Central

Welsh, Marilyn C.; Peterson, Eric; Jameson, Molly M.

2017-01-01

College students who report a history of childhood maltreatment may be at risk for poor outcomes. In the current study, we conducted an exploratory analysis to examine potential models that statistically mediate associations between aspects of maltreatment and aspects of academic outcome, with a particular focus on executive functions (EF). Consistent with contemporary EF research, we distinguished between relatively “cool” EF tasks (i.e., performed in a context relatively free of emotional or motivational valence) and “hot” EF tasks that emphasize performance under more emotionally arousing conditions. Sixty-one male and female college undergraduates self-reported childhood maltreatment history (emotional abuse and neglect, physical abuse and neglect, and sexual abuse) on the Childhood Trauma Questionnaire (CTQ), and were given two EF measures: (1) Go-No-Go (GNG) test that included a Color Condition (cool); Neutral Face Condition (warm); and Emotion Face condition (hot), and (2) Iowa Gambling Task (IGT), a measure of risky decision making that reflects hot EF. Academic outcomes were: (1) grade point average (GPA: first-semester, cumulative, and semester concurrent with testing), and (2) Student Adaptation to College Questionnaire (SACQ). Correlational patterns suggested two EF scores as potential mediators: GNG reaction time (RT) in the Neutral Face condition, and IGT Block 2 adaptive responding. Indirect effects analyses indicated that IGT Block 2 adaptive responding has an indirect effect on the relationship between CTQ Total score and 1st semester GPA, and between CTQ Emotional Abuse and concurrent GPA. Regarding college adaptation, we identified a consistent indirect effect of GNG Neutral Face RT on the relationship between CTQ Emotional Neglect and SACQ total, academic, social, and personal–emotional adaption scores. Our results demonstrate that higher scores on a child maltreatment history self-report negatively predict college academic outcomes as assessed by GPA and by self-reported adaptation. Further, relatively “hot” EF task performance on the IGT and GNG tasks serves as a link between child maltreatment experiences and college achievement and adaptation, suggesting that hot EF skills may be a fruitful direction for future intervention efforts to improve academic outcomes for this population. PMID:28725204

J-2X Powerpack hot-fire test

NASA Image and Video Library

2008-01-31

The first hot-fire test of the J-2X power pack 1A gas generator was performed Jan. 31 on the A-1 Test Stand at Stennis Space Center. Initial indications are that all test objectives were met. The test was designed as a 3.42-second helium spin start with gas generator ignition and it went the full scheduled duration. Test conductors reported a smooth start with normal shutdown and described the event as a 'good test.' The test was part of the early component testing for the new J-2X engine being built by NASA to power the Ares I and Ares V rockets that will carry humans back to the moon and on to Mars. It was performed as one in a series of 12 scheduled tests. Those tests began last November at Stennis, but the January 31 event represented the first hot-fire test. The Stennis tests are a critical step in the successful development of the J-2X engine.

Hot Ductility Behavior of Boron Containing Microalloyed Steels with Varying Manganese Contents

NASA Astrophysics Data System (ADS)

Brune, Tobias; Senk, Dieter; Walpot, Raphael; Steenken, Bernhard

2015-02-01

The hot ductility is measured for six different steel grades with different microalloying elements and with varying manganese contents using the hot tensile test machine with melting/solidification unit at the Department of Ferrous Metallurgy RWTH Aachen University. To identify the influence of manganese on hot ductility, tests are performed with varying the manganese content from 0.7 to 18.2 wt pct, a high manganese steel. Additionally, the effect of different cooling and strain rates is analyzed by changing the particular rate for selected samples in the minima. To investigate and detect the cause of cracking during testing, the fracture surfaces in the ductility minima are considered with scanning electron microscope-energy dispersive X-ray spectroscopy. Thermodynamic modeling is conducted on basis of the commercial software ThermoCalc©. A sharp decrease of the hot ductility is recognizable at 1398 K (1125 °C), at only 0.7 wt pct manganese because of the low manganese to sulfur ratio. The grades with a Mn content up to 1.9 wt pct show a good ductility with minimal ductility loss. In comparison, the steel grade with 18.2 wt pct has a poor hot ductility. Because of the formation of complex precipitates, where several alloying elements are involved, the influence of boron on hot ductility is not fully clarified. By increasing the cooling rate, the reduction of area values are shifted to smaller values. For high test temperatures, these measured values are decreased for lower strain rates. Thereby, an early drop of the ductility is noticeable for the high temperatures around 1373 K (1100 °C).

Simulator test to study hot-flow problems related to a gas cooled reactor

NASA Technical Reports Server (NTRS)

Poole, J. W.; Freeman, M. P.; Doak, K. W.; Thorpe, M. L.

1973-01-01

An advance study of materials, fuel injection, and hot flow problems related to the gas core nuclear rocket is reported. The first task was to test a previously constructed induction heated plasma GCNR simulator above 300 kW. A number of tests are reported operating in the range of 300 kW at 10,000 cps. A second simulator was designed but not constructed for cold-hot visualization studies using louvered walls. A third task was a paper investigation of practical uranium feed systems, including a detailed discussion of related problems. The last assignment resulted in two designs for plasma nozzle test devices that could be operated at 200 atm on hydrogen.

Hot, humid air decontamination of a C-130 aircraft contaminated with spores of two acrystalliferous Bacillus thuringiensis strains, surrogates for Bacillus anthracis.

PubMed

Buhr, T L; Young, A A; Bensman, M; Minter, Z A; Kennihan, N L; Johnson, C A; Bohmke, M D; Borgers-Klonkowski, E; Osborn, E B; Avila, S D; Theys, A M G; Jackson, P J

2016-04-01

To develop test methods and evaluate survival of Bacillus thuringiensis kurstaki cry(-) HD-1 and B. thuringiensis Al Hakam spores after exposure to hot, humid air inside of a C-130 aircraft. Bacillus thuringiensis spores were either pre-inoculated on 1 × 2 or 2 × 2 cm substrates or aerosolized inside the cargo hold of a C-130 and allowed to dry. Dirty, complex surfaces (10 × 10 cm) swabbed after spore dispersal showed a deposition of 8-10 log10 m(-2) through the entire cargo hold. After hot, humid air decontamination at 75-80°C, 70-90% relative humidity for 7 days, 87 of 98 test swabs covering 0·98 m(2) , showed complete spore inactivation. There was a total of 1·67 log10 live CFU detected in 11 of the test swabs. Spore inactivation in the 98 test swabs was measured at 7·06 log10 m(-2) . Laboratory test methods for hot, humid air decontamination were scaled for a large-scale aircraft field test. The C-130 field test demonstrated that hot, humid air can be successfully used to decontaminate an aircraft. Transition of a new technology from research and development to acquisition at a Technology Readiness Level 7 is unprecedented. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Sims Prototype System 2 test results: Engineering analysis

NASA Technical Reports Server (NTRS)

1978-01-01

The testing, problems encountered, and the results and conclusions obtained from tests performed on the IBM Prototype System, 2, solar hot water system, at the Marshall Space Flight Center Solar Test Facility was described. System 2 is a liquid, non draining solar energy system for supplying domestic hot water to single residences. The system consists of collectors, storage tank, heat exchanger, pumps and associated plumbing and controls.

A&M. Hot liquid waste holding tanks. Camera faces southeast. Located ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot liquid waste holding tanks. Camera faces southeast. Located in vicinity of TAN-616, hot liquid waste treatment plant. Date: November 13, 1953. INEEL negative no. 9159 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Basics of Solar Heating & Hot Water Systems.

ERIC Educational Resources Information Center

American Inst. of Architects, Washington, DC.

In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

Hot wire anemometer measurements in the unheated air flow tests of the SRB nozzle-to-case joint

NASA Technical Reports Server (NTRS)

Ramachandran, N.

1988-01-01

Hot-Wire Anemometer measurements made in the Solid Rocket Booster (SRB) nozzle-to-case joint are discussed. The study was undertaken to glean additional information on the circumferential flow induced in the SRB nozzle joint and the effect of this flow on the insulation bonding flaws. The tests were conducted on a full-scale, 2-D representation of a 65-in long segment of the SRB nozzle joint, with unheated air as the working fluid. Both the flight Mach number and Reynolds number were matched simultaneously and different pressure gradients imposed along the joint face were investigated. Hot-wire anemometers were used to obtain velocity data for different joint gaps and debond configurations. The procedure adopted for hot-wire calibration and use is outlined and the results from the tests summarized.

Hot deformation behaviors and processing maps of B{sub 4}C/Al6061 neutron absorber composites

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

Li, Yu-Li

In this study, the hot deformation behaviors of 30 wt.% B{sub 4}C/Al6061 neutron absorber composites (NACs) have been investigated by conducting isothermal compression tests at temperatures ranging from 653 K to 803 K and strain rates from 0.01 to 10 s{sup −1}. It was found that, during hot compression, the B{sub 4}C/Al6061 NACs exhibited a steady flow characteristic which can be expressed by the Zener-Hollomon parameter as a hyperbolic-sine function of flow stress. High average activation energy (185.62 kJ/mol) of B{sub 4}C/Al6061 NACs is noted in current study owing to the high content of B{sub 4}C particle. The optimum hotmore » working conditions for B{sub 4}C/Al6061 NACs are found to be 760–803 K/0.01–0.05 s{sup −1} based on processing map and microstructure evolution. Typical material instabilities are thought to be attributed to void formation, adiabatic shear bands (ASB), particle debonding, and matrix cracking. Finally, the effect of the plastic deformation zones (PDZs) on the microstructure evolution in this 30 wt.% B{sub 4}C/Al6061 composite is found to be very important. - Highlights: •The hot deformation behavior of the 30 wt.% B{sub 4}C/Al6061 NACs was first analyzed. •The 3D efficiency map and the instability map are developed. •The optimum hot working conditions were identified and validated by SEM and TEM. •The hot deformation schematic diagram of 30 wt.% B{sub 4}C/Al6061 NACs is developed.« less

Digital Image Correlation Techniques Applied to Large Scale Rocket Engine Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.

2016-01-01

Rocket engine hot-fire ground testing is necessary to understand component performance, reliability and engine system interactions during development. The J-2X upper stage engine completed a series of developmental hot-fire tests that derived performance of the engine and components, validated analytical models and provided the necessary data to identify where design changes, process improvements and technology development were needed. The J-2X development engines were heavily instrumented to provide the data necessary to support these activities which enabled the team to investigate any anomalies experienced during the test program. This paper describes the development of an optical digital image correlation technique to augment the data provided by traditional strain gauges which are prone to debonding at elevated temperatures and limited to localized measurements. The feasibility of this optical measurement system was demonstrated during full scale hot-fire testing of J-2X, during which a digital image correlation system, incorporating a pair of high speed cameras to measure three-dimensional, real-time displacements and strains was installed and operated under the extreme environments present on the test stand. The camera and facility setup, pre-test calibrations, data collection, hot-fire test data collection and post-test analysis and results are presented in this paper.

Modeling and FE Simulation of Quenchable High Strength Steels Sheet Metal Hot Forming Process

NASA Astrophysics Data System (ADS)

Liu, Hongsheng; Bao, Jun; Xing, Zhongwen; Zhang, Dejin; Song, Baoyu; Lei, Chengxi

2011-08-01

High strength steel (HSS) sheet metal hot forming process is investigated by means of numerical simulations. With regard to a reliable numerical process design, the knowledge of the thermal and thermo-mechanical properties is essential. In this article, tensile tests are performed to examine the flow stress of the material HSS 22MnB5 at different strains, strain rates, and temperatures. Constitutive model based on phenomenological approach is developed to describe the thermo-mechanical properties of the material 22MnB5 by fitting the experimental data. A 2D coupled thermo-mechanical finite element (FE) model is developed to simulate the HSS sheet metal hot forming process for U-channel part. The ABAQUS/explicit model is used conduct the hot forming stage simulations, and ABAQUS/implicit model is used for accurately predicting the springback which happens at the end of hot forming stage. Material modeling and FE numerical simulations are carried out to investigate the effect of the processing parameters on the hot forming process. The processing parameters have significant influence on the microstructure of U-channel part. The springback after hot forming stage is the main factor impairing the shape precision of hot-formed part. The mechanism of springback is advanced and verified through numerical simulations and tensile loading-unloading tests. Creep strain is found in the tensile loading-unloading test under isothermal condition and has a distinct effect on springback. According to the numerical and experimental results, it can be concluded that springback is mainly caused by different cooling rats and the nonhomogengeous shrink of material during hot forming process, the creep strain is the main factor influencing the amount of the springback.

40 CFR 1066.820 - Composite calculations for FTP exhaust emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... composite gaseous test results as a mass-weighted value, e [emission]-FTPcomp, in grams per mile using the... UDDS test interval (generally known as bag 1 and bag 2), in grams. D ct = the measured driving distance... emissions determined from the hot-start UDDS test interval in grams. This is the hot-stabilized portion from...

16 CFR § 1505.51 - Hot surfaces.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CHILDREN Policies and Interpretations § 1505.51 Hot surfaces. (a) Test probe. Section 1505.6(g)(2) defines... inches long. To test for accessibility using this test probe, it shall be inserted no more than 3 inches into any opening in the toy. Unless the probe contacts a surface within 3 inches of the plane of the...

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.

Space Launch System Base Heating Test: Environments and Base Flow Physics

NASA Technical Reports Server (NTRS)

Mehta, Manish; Knox, Kyle S.; Seaford, C. Mark; Dufrene, Aaron T.

2016-01-01

The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen- hydrogen rocket engines in the core-stage and two 5-segment solid rocket boosters and as a result six hot supersonic plumes interact within the aft section of the vehicle during ight. Due to the complex nature of rocket plume-induced ows within the launch vehicle base during ascent and a new vehicle con guration, sub-scale wind tunnel testing is required to reduce SLS base convective environment uncertainty and design risk levels. This hot- re test program was conducted at the CUBRC Large Energy National Shock (LENS) II short-duration test facility to simulate ight from altitudes of 50 kft to 210 kft. The test program is a challenging and innovative e ort that has not been attempted in 40+ years for a NASA vehicle. This presentation discusses the various trends of base convective heat ux and pressure as a function of altitude at various locations within the core-stage and booster base regions of the two-percent SLS wind tunnel model. In-depth understanding of the base ow physics is presented using the test data, infrared high-speed imaging and theory. The normalized test design environments are compared to various NASA semi- empirical numerical models to determine exceedance and conservatism of the ight scaled test-derived base design environments. Brief discussion of thermal impact to the launch vehicle base components is also presented.

Space Launch System Base Heating Test: Environments and Base Flow Physics

NASA Technical Reports Server (NTRS)

Mehta, Manish; Knox, Kyle S.; Seaford, C. Mark; Dufrene, Aaron T.

2016-01-01

The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen-hydrogen rocket engines in the core-stage and two 5-segment solid rocket boosters and as a result six hot supersonic plumes interact within the aft section of the vehicle during flight. Due to the complex nature of rocket plume-induced flows within the launch vehicle base during ascent and a new vehicle configuration, sub-scale wind tunnel testing is required to reduce SLS base convective environment uncertainty and design risk levels. This hot-fire test program was conducted at the CUBRC Large Energy National Shock (LENS) II short-duration test facility to simulate flight from altitudes of 50 kft to 210 kft. The test program is a challenging and innovative effort that has not been attempted in 40+ years for a NASA vehicle. This paper discusses the various trends of base convective heat flux and pressure as a function of altitude at various locations within the core-stage and booster base regions of the two-percent SLS wind tunnel model. In-depth understanding of the base flow physics is presented using the test data, infrared high-speed imaging and theory. The normalized test design environments are compared to various NASA semi-empirical numerical models to determine exceedance and conservatism of the flight scaled test-derived base design environments. Brief discussion of thermal impact to the launch vehicle base components is also presented.

A full-scale STOVL ejector experiment

NASA Technical Reports Server (NTRS)

Barankiewicz, Wendy S.

1993-01-01

The design and development of thrust augmenting short take-off and vertical landing (STOVL) ejectors has typically been an iterative process. In this investigation, static performance tests of a full-scale vertical lift ejector were performed at primary flow temperatures up to 1560 R (1100 F). Flow visualization (smoke generators, yarn tufts and paint dots) was used to assess inlet flowfield characteristics, especially around the primary nozzle and end plates. Performance calculations are presented for ambient temperatures close to 480 R (20 F) and 535 R (75 F) which simulate 'seasonal' aircraft operating conditions. Resulting thrust augmentation ratios are presented as functions of nozzle pressure ratio and temperature. Full-scale experimental tests such as this are expensive, and difficult to implement at engine exhaust temperatures. For this reason the utility of using similarity principles -- in particular, the Munk and Prim similarity principle for isentropic flow -- was explored. At different primary temperatures, exit pressure contours are compared for similarity. A nondimensional flow parameter is then shown to eliminate primary nozzle temperature dependence and verify similarity between the hot and cold flow experiments. Under the assumption that an appropriate similarity principle can be established, then properly chosen performance parameters should be similar for both hot flow and cold flow model tests.

Transient Pressure Test Article (TPTA) 1.1 and 1.1A, volume 1

NASA Technical Reports Server (NTRS)

Rebells, Clarence A.

1988-01-01

This final test report presents the results obtained during the static hot firing and cold-gas high Q tests of the first Transient Pressure Test Article (TPTA) 1.1. The TPTA consisted of field test joints A and B, which were the original RSRM J-insulation configuration, with a metal capture feature. It also consisted of a flight configuration nozzle-to-case test joint (Joint D) with shorter vent slots. Fluorocarbon O-rings were used in all the test joints. The purpose of the TPTA tests is to evaluate and characterize the RSMR field and nozzle-to-case joints under the influence of ignition and strut loads during liftoff anf high Q. All objectives of the cold-gas high Q (TPTA 1.1A) test were met and all measurements were close to predicted values. During the static hot-firing test (TPTA 1.1), the motor was inadvertently plugged by the quench injector plug, making it a more severe test, although no strut loads were applied. The motor was depressurized after approximately 11 min using an auxiliary system, and no anomalies were noted. In the static hot-firing test, pressure was incident on the insulation and the test joint gaps were within the predicted range. During the static hot-firing test, no strut loads were applied because the loading system malfunctioned. For this test, all measurements were within range of similar tests performed without strut loads.

Determination of hot-spot susceptibility of multistring photovoltaic modules in a central-station application

NASA Technical Reports Server (NTRS)

Gonzalez, C. C.; Weaver, R. W.; Ross, R. G., Jr.; Spencer, R.; Arnett, J. C.

1984-01-01

Part of the effort of the Jet Propulsion Laboratory (JPL) Flat-Plate Solar Array Project (FSA) includes a program to improve module and array reliability. A collaborative activity with industry dealing with the problem of hot-spot heating due to the shadowing of photovoltaic cells in modules and arrays containing several paralleled cell strings is described. The use of multiparallel strings in large central-station arrays introduces the likelihood of unequal current sharing and increased heating levels. Test results that relate power dissipated, current imbalance, cross-strapping frequency, and shadow configuration to hot-spot heating levels are presented. Recommendations for circuit design configurations appropriate to central-station applications that reduce the risk of hot-spot problems are offered. Guidelines are provided for developing hot-spot tests for arrays when current imbalance is a threat.

Diversity and Ecological Functions of Crenarchaeota in Terrestrial Hot Springs of Tengchong, China

NASA Astrophysics Data System (ADS)

Li, W.; Song, Z.; Chen, J.; Jiang, H.; Zhou, E.; Wang, F.; Xiao, X.; Zhang, C.

2010-12-01

The diversity and potential ecological functions of Crenarchaeota were investigated in eight terrestrial hot springs (pH: 2.8-7.7; temperature: 43.6-96 C) located in Tengchong, China, using 16S rRNA gene phylogenetic analysis. A total of 826 crenarchaeotal clones were analyzed and a total of 47 Operational taxonomic units (OTUs) were identified. Most (93%) of the identified OTUs were closely related (89-99%) to those retrieved from hot springs and other thermal environments. Our data showed that temperature may predominate over pH in affecting crenarchaeotal diversity in Tengchong hot springs. Crenarchaeotal diversity in moderate-temperature (59 to 77 C) hot springs was the highest, indicating that the moderate-temperature hot springs are more inclusive for Crenarchaeota. To understand what ecological functions these Crenarchaeota may play in Tengchong hot springs, we isolated the environmental RNA and constructed four cDNA clone libraries of the archaeal accA gene that encodes Acetyl CoA carboxylase. The accA gene represents one of the key enzymes responsible for the CO2 fixation in the 3-hydroxypropionate/4-hydroxybutyrate pathway. The results of phylogenetic analysis showed all the transcribed accA gene sequences can be classified into three large clusters, with the first one being affiliated with marine crenarchaeota, the second one with cultured crenarchaeota, and the third one with Chlorobi (Green sulfur bacteria), which have been proved to employ the 3-hydroxypropionate/4-hydroxybutyrate pathway. The long-branch distances of the phylogenetic tree suggest that these sequences represent novel accA-like gene. Our results also showed that sequences of the accA-like gene from the same hot spring belonged to one cluster, which suggests that a single crenarchaeotal group may fix CO2 via 3-hydroxypropionate/4-hydroxybutyrate pathway in the investigated hot springs.

HOT CELL BUILDING, TRA632. WHILE STEEL BEAMS DEFINE FUTURE WALLS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. WHILE STEEL BEAMS DEFINE FUTURE WALLS OF THE BUILDING, SHEET STEEL DEFINES THE HOT CELL "BOX" ITSELF. THREE OPERATING WINDOWS ON LEFT; ONE VIEWING WINDOW ON RIGHT. TUBES WILL CONTAIN SERVICE AND CONTROL LEADS. SPACE BETWEEN INNER AND OUTER BOX WALLS WILL BE FILLED WITH SHIELDED WINDOWS AND BARETES CONCRETE. CAMERA FACES SOUTHEAST. INL NEGATIVE NO. 7933. Unknown Photographer, ca. 5/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

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

Chen, B.; Lu, S. X.; Li, C. H.

In an atrium measured 120 m by 180 m by 36.5 m high, fire tests were conducted under 'natural filling' and 'mechanical exhaust' conditions by hot smoke test method. The fire size was 8 MW released by an ethanol pool of 3.6 m in diameter. The distribution of vertical temperature profiles above the fire source and the gas layer temperatures were measured. From these measurements, it was shown that the fans successfully exhausted hot smoke to control descending of hot smoke layer and temperature rising rate. The hot smoke layer can be maintained at about 30 m which was almostmore » 2 times of hot layer height in 'natural filling' condition. The temperature risings in both conditions were too low to cause thermal damage to the structure, only 18.6 K and 12 K. The centerline temperature above the fire source and the height of hot smoke layer were calculated using the plume models. The calculated results agreed well with the conclusions obtained from the experiment results.« less

Life testing of a nine-couple hybrid thermoelectric panel

NASA Technical Reports Server (NTRS)

Bifano, W. J.

1973-01-01

Life test data are presented for a nine couple thermoelectric panel of hybrid couples tested at an average hot junction temperature of 840 C (1113 K). In the hybrid couple, a hollow cylinder of p-type Si-Ge is used to encapsulate a segmented PbTe/Si-Ge n-leg. The output power and internal resistance of the panel as well as the resistances of the individual hybrid couples are presented as functions of test time covering a period of more than 4200 hours. Test results indicated improved stability relative to hybrid couples tested at higher temperatures. Thermal cycling of the panel resulted in an order of magnitude increase in room temperature resistance. However, very little change in resistance at operating temperatures was noted following the thermal cycles.

Toolkit for testing scientific CCD cameras

NASA Astrophysics Data System (ADS)

Uzycki, Janusz; Mankiewicz, Lech; Molak, Marcin; Wrochna, Grzegorz

2006-03-01

The CCD Toolkit (1) is a software tool for testing CCD cameras which allows to measure important characteristics of a camera like readout noise, total gain, dark current, 'hot' pixels, useful area, etc. The application makes a statistical analysis of images saved in files with FITS format, commonly used in astronomy. A graphical interface is based on the ROOT package, which offers high functionality and flexibility. The program was developed in a way to ensure future compatibility with different operating systems: Windows and Linux. The CCD Toolkit was created for the "Pie of the Sky" project collaboration (2).

Generalized Constitutive-Based Theoretical and Empirical Models for Hot Working Behavior of Functionally Graded Steels

NASA Astrophysics Data System (ADS)

Vanini, Seyed Ali Sadough; Abolghasemzadeh, Mohammad; Assadi, Abbas

2013-07-01

Functionally graded steels with graded ferritic and austenitic regions including bainite and martensite intermediate layers produced by electroslag remelting have attracted much attention in recent years. In this article, an empirical model based on the Zener-Hollomon (Z-H) constitutive equation with generalized material constants is presented to investigate the effects of temperature and strain rate on the hot working behavior of functionally graded steels. Next, a theoretical model, generalized by strain compensation, is developed for the flow stress estimation of functionally graded steels under hot compression based on the phase mixture rule and boundary layer characteristics. The model is used for different strains and grading configurations. Specifically, the results for αβγMγ steels from empirical and theoretical models showed excellent agreement with those of experiments of other references within acceptable error.

Thermal Shock and Ablation Behavior of Tungsten Nozzle Produced by Plasma Spray Forming and Hot Isostatic Pressing

NASA Astrophysics Data System (ADS)

Wang, Y. M.; Xiong, X.; Zhao, Z. W.; Xie, L.; Min, X. B.; Yan, J. H.; Xia, G. M.; Zheng, F.

2015-08-01

Tungsten nozzle was produced by plasma spray forming (PSF, relative density of 86 ± 2%) followed by hot isostatic pressing (HIPing, 97 ± 2%) at 2000 °C and 180 MPa for 180 min. Scanning electron microscope, x-ray diffractometer, Archimedes method, Vickers hardness, and tensile tests have been employed to study microstructure, phase composition, density, micro-hardness, and mechanical properties of the parts. Resistance of thermal shock and ablation behavior of W nozzle were investigated by hot-firing test on solid rocket motor (SRM). Comparing with PSF nozzle, less damage was observed for HIPed sample after SRM test. Linear ablation rate of nozzle made by PSF was (0.120 ± 0.048) mm/s, while that after HIPing reduced to (0.0075 ± 0.0025) mm/s. Three types of ablation mechanisms including mechanical erosion, thermophysical erosion, and thermochemical ablation took place during hot-firing test. The order of degree of ablation was nozzle throat > convergence > dilation inside W nozzle.

Hot film wall shear instrumentation for compressible boundary layer transition research

NASA Technical Reports Server (NTRS)

Schneider, Steven P.

1992-01-01

Experimental and analytical studies of hot film wall shear instrumentation were performed. A new hot film anemometer was developed and tested. The anemometer performance was not quite as good as that of commercial anemometers, but the cost was much less and testing flexibility was improved. The main focus of the project was a parametric study of the effect of sensor size and substrate material on the performance of hot film surface sensors. Both electronic and shock-induced flow experiments were performed to determine the sensitivity and frequency response of the sensors. The results are presented in Michael Moen's M.S. thesis, which is appended. A condensed form of the results was also submitted for publication.

HOT CELL BUILDING, TRA632. CONTEXTUAL AERIAL VIEW OF HOT CELL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. CONTEXTUAL AERIAL VIEW OF HOT CELL BUILDING, IN VIEW AT LEFT, AS YET WITHOUT ROOF. PLUG STORAGE BUILDING LIES BETWEEN IT AND THE SOUTH SIDE OF THE MTR BUILDING AND ITS WING. NOTE CONCRETE DRIVE BETWEEN ROLL-UP DOOR IN MTR BUILDING AND CHARGING FACE OF PLUG STORAGE. REACTOR SERVICES BUILDING (TRA-635) WILL COVER THIS DRIVE AND BUTT UP TO CHARGING FACE. DOTTED LINE IS ON ORIGINAL NEGATIVE. TRA PARKING LOT IN LEFT CORNER OF THE VIEW. CAMERA FACING NORTHWESTERLY. INL NEGATIVE NO. 8274. Unknown Photographer, 7/2/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Parts, Materials, and Processes Control Program for Expendable Launch Vehicles

DTIC Science & Technology

2015-05-21

CSAM, thermal shock, voltage burn-in, electrical tests (DWV, room and hot IR, partial discharge when in corona region); perform DPA with SEM/EDX...controls to eliminate dielectric defects; proper voltage derating. Partial discharge testing, corona inception testing up to 60% of rated voltage...voltage burn-in; DWV; room and hot IR; life test; partial discharge when in corona region B-7 Table B-5. Metallized Plastic Capacitors

Thermal Characterization of Epoxy Adhesive by Hotfire Testing

NASA Technical Reports Server (NTRS)

Spomer, Ken A.; Haddock, M. Reed; McCool, Alex (Technical Monitor)

2001-01-01

This paper describes subscale solid-rocket motor hot-fire testing of epoxy adhesives in flame surface bondlines to evaluate heat-affected depth, char depth and ablation rate. Hot-fire testing is part of an adhesive down-selection program on the Space Shuttle Solid Rocket Motor Nozzle to provide additional confidence in the down-selected adhesives. The current nozzle structural adhesive bond system is being replaced due to obsolescence. Prior to hot-fire testing, adhesives were tested for chemical, physical and mechanical properties, which resulted in the selection of two potential replacement adhesives, Resin Technology Group's TIGA 321 and 3M's EC2615XLW. Hot-fire testing consisted of four forty-pound charge (FPC) motors fabricated in configurations that would allow side-by-side comparison testing of the candidate replacement adhesives with the current RSRM adhesives. Results of the FPC motor testing show that: 1) the phenolic char depths on radial bondlines is approximately the same and vary depending on the position in the blast tube regardless of which adhesive was used, 2) the replacement candidate adhesive char depths are equivalent to the char depths of the current adhesives, 3) the heat-affected depths of the candidate and current adhesives are equivalent, and 4) the ablation rates for both replacement adhesives were equivalent to the current adhesives.

Numb rats walk - a behavioural and fMRI comparison of mild and moderate spinal cord injury.

PubMed

Hofstetter, Christoph P; Schweinhardt, Petra; Klason, Tomas; Olson, Lars; Spenger, Christian

2003-12-01

Assessment of sensory function serves as a sensitive measure for predicting the functional outcome following spinal cord injury in patients. However, little is known about loss and recovery of sensory function in rodent spinal cord injury models as most tests of sensory functions rely on behaviour and thus motor function. We used functional magnetic resonance imaging (fMRI) to investigate cortical and thalamic BOLD-signal changes in response to limb stimulation following mild or moderate thoracic spinal cord weight drop injury in Sprague-Dawley rats. While there was recovery of close to normal hindlimb motor function as determined by open field locomotor testing following both degrees of injury, recovery of hindlimb sensory function as determined by fMRI and hot plate testing was only seen following mild injury and not following moderate injury. Thus, moderate injury can lead to near normal hindlimb motor function in animals with major sensory deficits. Recovered fMRI signals following mild injury had a partly altered cortical distribution engaging also ipsilateral somatosensory cortex and the cingulate gyrus. Importantly, thoracic spinal cord injury also affected sensory representation of the upper nonaffected limbs. Thus, cortical and thalamic activation in response to forelimb stimulation was significantly increased 16 weeks after spinal cord injury compared to control animals. We conclude that both forelimb and hindlimb cortical sensory representation is altered following thoracic spinal cord injury. Furthermore tests of sensory function that are independent of motor behaviour are needed in rodent spinal cord injury research.

Chronodiagnostic acquisition of recovery speed of heart rate under bathing stress.

PubMed

Ishijima, M; Togawa, T

1999-11-01

Cycling on an ergometer is one effective means of measuring cardiovascular function while applying stress on the heart. Bathing in a hot water bath applies a low stress to the heart. The electrocardiograms of a healthy adult male (aged 35 at the start of study) were recorded while taking a hot water bath with no electrode attached to the body over a period of 2 years (376 days over a 762 day period). The recovery speed following the initial overshoot of the heart rate (HR) was observed. The bathtub was designed for the automatic acquisition of ECG data. Immediately after immersion in the tub, the HR reached a peak within 20 s and then exponentially decreased toward the lowest rate in the 120 s of bathing. The initial recovery speed of the HR from the stress of bathing had a specific rhythm in the subject. Spectrum analysis of the speed series indicated that slow recovery speed appeared in cyclic periods of approximately 1 year, 42 days and 17 days. The methodology may provide a chronodiagnostic index of an exercise test for cardiovascular function.

Flight Demonstration of a Shock Location Sensor Using Constant Voltage Hot-Film Anemometry

NASA Technical Reports Server (NTRS)

Moes, Timothy R.; Sarma, Garimella R.; Mangalam, Siva M.

1997-01-01

Flight tests have demonstrated the effectiveness of an array of hot-film sensors using constant voltage anemometry to determine shock position on a wing or aircraft surface at transonic speeds. Flights were conducted at the NASA Dryden Flight Research Center using the F-15B aircraft and Flight Test Fixture (FTF). A modified NACA 0021 airfoil was attached to the side of the FTF, and its upper surface was instrumented to correlate shock position with pressure and hot-film sensors. In the vicinity of the shock-induced pressure rise, test results consistently showed the presence of a minimum voltage in the hot-film anemometer outputs. Comparing these results with previous investigations indicate that hot-film anemometry can identify the location of the shock-induced boundary layer separation. The flow separation occurred slightly forward of the shock- induced pressure rise for a laminar boundary layer and slightly aft of the start of the pressure rise when the boundary layer was tripped near the airfoil leading edge. Both minimum mean output and phase reversal analyses were used to identify the shock location.

Comparison of fundamental and simulative test methods for evaluating permanent deformation of hot mix asphalt

DOT National Transportation Integrated Search

2002-10-01

Rutting has long been a problem in hot mix asphalt (HMA) pavement. Through the years, researchers have used different kinds of fundamental and simulative test methods to estimate the rutting performance of HMA. It has been recognized that most fundam...

Channel Wall Nozzle Hot-fire Tests

NASA Image and Video Library

2018-03-16

A subscale channel wall nozzle is hot-fire tested in November 2017 at NASA's Marshall Space Flight Center. The nozzle was fabricated using three separate, state-of-the-art, advanced manufacturing technologies including a new process called Laser Wire Direct Closeout that was co-developed and advanced at Marshall.

Centrally mediated antinociceptive effects of cannabinoid receptor ligands in rat models of nociception

PubMed Central

Hama, Aldric; Sagen, Jacqueline

2011-01-01

The endogenous nonapeptide hemopressin (HE) demonstrates potent block of the cannabinoid subtype-1 (CB1) receptor in vitro and robust antinociception in vivo. The current study evaluated the effects of centrally administered HE in mechanistically distinct pre-clinical rat models of pain—the hot plate test and the hind paw formalin test. The non-subtype selective CB receptor agonist WIN 55,212-2 was tested concurrently as a positive control. In the hot plate test, neither intrathecal (i.t.) HE nor WIN 55,212-2 significantly altered the latency to respond to noxious heat. By contrast, i.t. HE and WIN 55,212-2 significantly reduced pain-related behaviors in the formalin test. Possible HE functionality as a CB1 receptor antagonist at the spinal level was evaluated in the formalin test. Intrathecal pretreatment with HE did not attenuate the antinociceptive effect of i.t. WIN 55,212-2. However, pretreatment with the CB1 receptor antagonist rimonabant did; i.t. rimonabant pretreatment was not antinociceptive. Potential supraspinal antinociceptive activity of HE was also evaluated. Whereas intracerebroventricular (i.c.v.) injection of WIN 55,212-2 reduced pain-related behaviors in the formalin test, interestingly, i.c.v. HE increased behaviors. In the current study, an antinociceptive effect with the CB receptor ligand HE was obtained under the specific condition of tissue injury and not in the uninjured state. Thus, HE could be a useful analgesic peptide with a novel spinal mechanism of action. PMID:21958947

Hot corrosion of four superalloys - HA-188, S-57, IN-617, and TD-NiCrAl

NASA Technical Reports Server (NTRS)

Santoro, G. J.

1979-01-01

Cyclic oxidation and hot corrosion tests of two cobalt-base and two nickel-base alloys are reported. The alloys were exposed to maximum temperatures of 900 and 1000 C in a Mach 0.3 burner rig whose flame was doped with various concentrations of sea salt and sodium sulfate for hot corrosion tests. The test data were subjected to a regression analysis for the development of model equations relating corrosion to temperature and for the effects of salt concentration and composition on corrosion. The corrosion resistance varied with temperature, sea salt concentration, and salt composition, concluding that the S-57 cobalt-base alloy was the most hot corrosion-resistant alloy, and the TD-NiCrAl nickel-base alloy was the least resistant. However, under straight oxidation conditions, the TD-NiCrAl was most resistant, while S-57 was the least resistant alloy.

Induction of colonic aberrant crypts in mice by feeding apparent N-nitroso compounds derived from hot dogs

PubMed Central

Davis, Michael E; Lisowyj, Michal P; Zhou, Lin; Wisecarver, James L; Gulizia, James M; Shostrom, Valerie K; Naud, Nathalie; Corpet, Denis E; Mirvish, Sidney S

2012-01-01

Nitrite-preserved meats (e.g., hot dogs) may help cause colon cancer because they contain N-nitroso compounds. We tested whether purified hot-dog-derived total apparent N-nitroso compounds (ANC) could induce colonic aberrant crypts, which are putative precursors of colon cancer. We purified ANC precursors in hot dogs and nitrosated them to produce ANC. In preliminary tests, CF1 mice received 1 or 3 i.p. injections of 5mg azoxymethane (AOM)/kg. In Experiments 1 and 2, female A/J mice received ANC in diet. In Experiment 1, ANC dose initially dropped sharply because the ANC precursors had mostly decomposed but, later in Experiment 1 and throughout Experiment 2, ANC remained at 85 nmol/g diet. Mice were killed after 8 (AOM tests) or 17–34 (ANC tests) wk. Median numbers of aberrant crypts in the distal 2 cm of the colon for 1 and 3 AOM injections, CF1 controls, ANC (Experiment 1), ANC (Experiment 2),and untreated A/J mice were 31, 74, 12, 20, 12, and 5–6, with P < 0.01 for both ANC tests. Experiment 2 showed somewhat increased numbers of colonic mucin-depleted foci in the ANC-treated group. We conclude that hot-dog-derived ANC induced significant numbers of aberrant crypts in the mouse colon. PMID:22293095

Application of annular centrifugal contactors in the hot test of the improved total partitioning process for high level liquid waste.

PubMed

Duan, Wuhua; Chen, Jing; Wang, Jianchen; Wang, Shuwei; Feng, Xiaogui; Wang, Xinghai; Li, Shaowei; Xu, Chao

2014-08-15

High level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, (90)Sr, (137)Cs, etc., and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P&T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. An improved total partitioning process, including a TRPO (tri-alkylphosphine oxide) process for the removal of actinides, a CESE (crown ether strontium extraction) process for the removal of Sr, and a CECE (calixcrown ether cesium extraction) process for the removal of Cs, has been developed to treat Chinese HLLW. A 160-hour hot test of the improved total partitioning process was carried out using 72-stage 10-mm-dia annular centrifugal contactors (ACCs) and genuine HLLW. The hot test results showed that the average DFs of total α activity, Sr and Cs were 3.57 × 10(3), 2.25 × 10(4) and 1.68 × 10(4) after the hot test reached equilibrium, respectively. During the hot test, 72-stage 10-mm-dia ACCs worked stable, continuously with no stage failing or interruption of the operation. Copyright © 2014 Elsevier B.V. All rights reserved.

Physiological and performance responses to a training camp in the heat in professional Australian football players.

PubMed

Racinais, Sebastien; Buchheit, Martin; Bilsborough, Johann; Bourdon, Pitre C; Cordy, Justin; Coutts, Aaron J

2014-07-01

To examine the physiological and performance responses to a heat-acclimatization camp in highly trained professional team-sport athletes. Eighteen male Australian Rules Football players trained for 2 wk in hot ambient conditions (31-33°C, humidity 34-50%). Players performed a laboratory-based heat-response test (24-min walk + 24 min seated; 44°C), a YoYo Intermittent Recovery Level 2 Test (YoYoIR2; indoor, temperate environment, 23°C) and standardized training drills (STD; outdoor, hot environment, 32°C) at the beginning and end of the camp. The heat-response test showed partial heat acclimatization (eg, a decrease in skin temperature, heart rate, and sweat sodium concentration, P < .05). In addition, plasma volume (PV, CO rebreathing, +2.68 [0.83; 4.53] mL/kg) and distance covered during both the YoYoIR2 (+311 [260; 361] m) and the STD (+45.6 [13.9; 77.4] m) increased postcamp (P < .01). None of the performance changes showed clear correlations with PV changes (r < .24), but the improvements in running STD distance in hot environment were correlated with changes in hematocrit during the heat-response test (r = -.52, 90%CI [-.77; -.12]). There was no clear correlation between the performance improvements in temperate and hot ambient conditions (r < .26). Running performance in both hot and temperate environments was improved after a football training camp in hot ambient conditions that stimulated heat acclimatization. However, physiological and performance responses were highly individual, and the absence of correlations between physical-performance improvements in hot and temperate environments suggests that their physiological basis might differ.

Menopausal hot flashes: Randomness or rhythmicity

NASA Astrophysics Data System (ADS)

Kronenberg, Fredi

1991-10-01

Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.

100-lbf LO2/CH4 RCS Thruster Testing and Validation

NASA Technical Reports Server (NTRS)

Barnes, Frank; Cannella, Matthew; Gomez, Carlos; Hand, Jeffrey; Rosenberg, David

2009-01-01

100 pound thrust liquid Oxygen-Methane thruster sized for RCS (Reaction Control System) applications. Innovative Design Characteristics include: a) Simple compact design with minimal part count; b) Gaseous or Liquid propellant operation; c) Affordable and Reusable; d) Greater flexibility than existing systems; e) Part of NASA'S study of "Green Propellants." Hot-fire testing validated performance and functionality of thruster. Thruster's dependence on mixture ratio has been evaluated. Data has been used to calculate performance parameters such as thrust and Isp. Data has been compared with previous test results to verify reliability and repeatability. Thruster was found to have an Isp of 131 s and 82 lbf thrust at a mixture ratio of 1.62.

In-flight comparisons of boundary-layer and wake measurement probes for incompressible flow

NASA Technical Reports Server (NTRS)

Mertaugh, L. J., Jr.

1972-01-01

The results are presented of in-flight comparisons of a number of boundary-layer and wake measurement probes suitable for low-speed flight-test investigations. The tested boundary-layer probes included a traversing total-pressure probe and a hot-film probe mounted on an internally-mounted drive mechanism, a curved and a straight boundary-layer rake, and a traversing hot-film probe with an externally-mounted drive mechanism. The wake measuring devices included a traversing, self-aligning probe, a wake rake, and an integrating wake rate. The boundary-layer data are compared with a common reference velocity profile and comments given regarding the accuracy of the static-pressure and total-pressure measurements. Discussions on the various calibration presentations used with hot-wire and hot-film sensors and various aspects of improving the accuracy of hot-film sensor results are given in the appendix of this report.

Calculation of plasma dielectric response in inhomogeneous magnetic field near electron cyclotron resonance

NASA Astrophysics Data System (ADS)

Evstatiev, Evstati; Svidzinski, Vladimir; Spencer, Andy; Galkin, Sergei

2014-10-01

Full wave 3-D modeling of RF fields in hot magnetized nonuniform plasma requires calculation of nonlocal conductivity kernel describing the dielectric response of such plasma to the RF field. In many cases, the conductivity kernel is a localized function near the test point which significantly simplifies numerical solution of the full wave 3-D problem. Preliminary results of feasibility analysis of numerical calculation of the conductivity kernel in a 3-D hot nonuniform magnetized plasma in the electron cyclotron frequency range will be reported. This case is relevant to modeling of ECRH in ITER. The kernel is calculated by integrating the linearized Vlasov equation along the unperturbed particle's orbits. Particle's orbits in the nonuniform equilibrium magnetic field are calculated numerically by one of the Runge-Kutta methods. RF electric field is interpolated on a specified grid on which the conductivity kernel is discretized. The resulting integrals in the particle's initial velocity and time are then calculated numerically. Different optimization approaches of the integration are tested in this feasibility analysis. Work is supported by the U.S. DOE SBIR program.

Comparison of an indirect tri-planar myofascial release (MFR) technique and a hot pack for increasing range of motion.

PubMed

Kain, Jay; Martorello, Laura; Swanson, Edward; Sego, Sandra

2011-01-01

The purpose of the randomized clinical study was to scientifically assess which intervention increases passive range of motion most effectively: the indirect tri-planar myofascial release (MFR) technique or the application of hot packs for gleno-humeral joint flexion, extension, and abduction. A total of 31 participants from a sample of convenience were randomly assigned to examine whether or not MFR was as effective in increasing range of motion as hot packs. The sample consisted of students at American International College. Students were randomly assigned to two groups: hot pack application (N=13) or MFR technique (N=18). The independent variable was the intervention, either the tri-planar MFR technique or the hot pack application. Group one received the indirect tri-planar MFR technique once for 3min. Group two received one hot pack application for 20min. The dependent variables, passive gleno-humeral shoulder range of motion in shoulder flexion, shoulder extension, and shoulder abduction, were taken pre- and post-intervention for both groups. Data was analyzed through the use of a two-way factorial design with mixed-factors ANOVA. Prior to conducting the study, inter-rater reliability was established using three testers for goniometric measures. A 2 (type of intervention: hot packs or MFR) by 2 (pre-test or post-test) mixed-factors ANOVA was calculated. Significant increases in range of motion were found for flexion, extension and abduction when comparing pre-test scores to post-test scores. The results of the ANOVA showed that for passive range of motion no differences were found for flexion, extension and abduction between the effectiveness of hot packs and MFR. For each of the dependent variables measured, MFR was shown to be as effective as hot packs in increasing range of motion, supporting the hypothesis. Since there was no significant difference between the types of intervention, both the hot pack application and the MFR technique were found to be equally effective in increasing passive range of motion of the joint in flexion, extension, and abduction of the gleno-humeral joint. The indirect tri-planar intervention could be considered more effective as an intervention in terms of time spent with a patient and the number of patients seen in a 20-min period. No equipment is required to carry out the MFR intervention, whereby using a hot pack requires the hot pack, towels, and a hydraculator unit with the use of the indirect tri-planar intervention, a therapist could treat four to five patients in the time it would take for one standard hot pack treatment of 20min, less the hands-on intervention of the therapist. Copyright © 2009 Elsevier Ltd. All rights reserved.

COMPARATIVE U.S./USSR TESTS OF A HOT-SIDE ELECTROSTATIC PRECIPITATOR

EPA Science Inventory

The report describes a U.S./USSR cooperative test program to quantify and characterize particulate emissions from a U.S. coal-burning power plant boiler, equipped with a hot-side electrostatic precipitator, at Duke Power Co.'s Allen Steam Station in March 1976. U.S. and Soviet eq...

Development of a test to measure the tendency for a hot-mix asphalt to segregate

DOT National Transportation Integrated Search

2000-02-01

Hot Mix Asphalt tends to segregate during handling and placement. The use of a test to determine the tendency to segregate would assist the user in determining when a mix gradation needs adjustment to avoid construction of a segregated pavement or wh...

Verification test report on a solar heating and hot water system

NASA Technical Reports Server (NTRS)

1978-01-01

Information is provided on the development, qualification and acceptance verification of commercial solar heating and hot water systems and components. The verification includes the performances, the efficiences and the various methods used, such as similarity, analysis, inspection, test, etc., that are applicable to satisfying the verification requirements.

Raising test scores vs. teaching higher order thinking (HOT): senior science teachers' views on how several concurrent policies affect classroom practices

NASA Astrophysics Data System (ADS)

Zohar, Anat; Alboher Agmon, Vered

2018-04-01

This study investigates how senior science teachers viewed the effects of a Raising Test Scores policy and its implementation on instruction of higher order thinking (HOT), and on teaching thinking to students with low academic achievements.

Evaluating the impacts of reducing the number of hot mix asphalt plant testing acceptance criteria on mix variability.

DOT National Transportation Integrated Search

2012-11-01

The acceptance testing of Hot Mix Asphalt (HMA) conducted at the HMA production facility is an : important portion of the overall acceptance process used by the Connecticut Department of : Transportation (ConnDOT) for paving projects. In 2004, ConnDO...

Analysis of difficulties in mathematics learning on students with guardian personality type in problem-solving HOTS geometry test

NASA Astrophysics Data System (ADS)

Karimah, R. K. N.; Kusmayadi, T. A.; Pramudya, I.

2018-04-01

Learning in the current 2013 curriculum is based on contextual issues based on questions that can encourage students to think broadly. HOTS is a real-life based assessment of everyday life, but in practice, the students are having trouble completing the HOTS issue. Learning difficulty is also influenced by personality type Based on the fact that the real difference one can see from a person is behavior. Kersey classifies the personality into 4 types, namely Idealist, Rational, Artisan, and Guardian. The researcher focuses on the type of guardian personality that is the type of personality that does not like the picture. This study aims to describe the difficulty of learning mathematics in students with a type of guardian personality in the completion of Geometry materials especially in solving HOTS. This research type is descriptive qualitative research. Instruments used in this study were the researchers themselves, personality class test sheets, learning difficulty test sheets in the form of HOTS Geometry test, and interview guides. The results showed that students with guardian personality it was found that a total of 3.37 % difficulties of number fact skill, 4.49 % difficulties of arithmetics skill, 37.08 % difficulties of information skill, 31.46% difficulties of language skill, 23.60 % difficulties of visual-spatial skill.

LAMOST telescope reveals that Neptunian cousins of hot Jupiters are mostly single offspring of stars that are rich in heavy elements.

PubMed

Dong, Subo; Xie, Ji-Wei; Zhou, Ji-Lin; Zheng, Zheng; Luo, Ali

2018-01-09

We discover a population of short-period, Neptune-size planets sharing key similarities with hot Jupiters: both populations are preferentially hosted by metal-rich stars, and both are preferentially found in Kepler systems with single-transiting planets. We use accurate Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 4 (DR4) stellar parameters for main-sequence stars to study the distributions of short-period [Formula: see text] Kepler planets as a function of host star metallicity. The radius distribution of planets around metal-rich stars is more "puffed up" compared with that around metal-poor hosts. In two period-radius regimes, planets preferentially reside around metal-rich stars, while there are hardly any planets around metal-poor stars. One is the well-known hot Jupiters, and the other one is a population of Neptune-size planets ([Formula: see text]), dubbed "Hoptunes." Also like hot Jupiters, Hoptunes occur more frequently in systems with single-transiting planets although the fraction of Hoptunes occurring in multiples is larger than that of hot Jupiters. About [Formula: see text] of solar-type stars host Hoptunes, and the frequencies of Hoptunes and hot Jupiters increase with consistent trends as a function of [Fe/H]. In the planet radius distribution, hot Jupiters and Hoptunes are separated by a "valley" at approximately Saturn size (in the range of [Formula: see text]), and this "hot-Saturn valley" represents approximately an order-of-magnitude decrease in planet frequency compared with hot Jupiters and Hoptunes. The empirical "kinship" between Hoptunes and hot Jupiters suggests likely common processes (migration and/or formation) responsible for their existence.

LAMOST telescope reveals that Neptunian cousins of hot Jupiters are mostly single offspring of stars that are rich in heavy elements

NASA Astrophysics Data System (ADS)

Dong, Subo; Xie, Ji-Wei; Zhou, Ji-Lin; Zheng, Zheng; Luo, Ali

2018-01-01

We discover a population of short-period, Neptune-size planets sharing key similarities with hot Jupiters: both populations are preferentially hosted by metal-rich stars, and both are preferentially found in Kepler systems with single-transiting planets. We use accurate Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 4 (DR4) stellar parameters for main-sequence stars to study the distributions of short-period 1d

The Development of Expansion Plug Wedge Test for Clad Tubing Structure Mechanical Property Evaluation

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

Wang, Jy-An John; Jiang, Hao

2016-01-12

To determine the tensile properties of irradiated fuel cladding in a hot cell, a simple test was developed at the Oak Ridge National Laboratory (ORNL) and is described fully in US Patent Application 20060070455, “Expanded plug method for developing circumferential mechanical properties of tubular materials.” This method is designed for testing fuel rod cladding ductility in a hot cell using an expandable plug to stretch a small ring of irradiated cladding material. The specimen strain is determined using the measured diametrical expansion of the ring. This method removes many complexities associated with specimen preparation and testing. The advantages are themore » simplicity of measuring the test component assembly in the hot cell and the direct measurement of the specimen’s strain. It was also found that cladding strength could be determined from the test results.« less

Calculations of heavy ion charge state distributions for nonequilibrium conditions

NASA Technical Reports Server (NTRS)

Luhn, A.; Hovestadt, D.

1985-01-01

Numerical calculations of the charge state distributions of test ions in a hot plasma under nonequilibrium conditions are presented. The mean ionic charges of heavy ions for finite residence times in an instantaneously heated plasma and for a non-Maxwellian electron distribution function are derived. The results are compared with measurements of the charge states of solar energetic particles, and it is found that neither of the two simple cases considered can explain the observations.

Green Monopropellant Status at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Burnside, Christopher G.; Pierce, Charles W.; Pedersen, Kevin W.

2016-01-01

NASA Marshall Space Flight Center is continuing investigations into the use of green monopropellants as a replacement for hydrazine in spacecraft propulsion systems. Work to date has been to push technology development through multiple activities designed to understand the capabilities of these technologies. Future work will begin to transition to mission pull as these technologies are mature while still keeping a solid goal of pushing technology development as opportunities become available. The AF-M315E activities began with hot-fire demonstration testing of a 1N monopropellant thruster in FY 14 and FY15. Following successful completion of the preliminary campaign, changes to the test stand to accommodate propellant conditioning capability and better control of propellant operations was incorporated to make testing more streamlined. The goal is to conduct hot-fire testing with warm and cold propellants using the existing feed system and original thruster design. Following the 1N testing, a NASA owned 100 mN thruster will be hot-fire tested in the same facility to show feasibility of scaling to smaller thrusters for cubesat applications. The end goal is to conduct a hot-fire test of an integrated cubesat propulsion system using an SLM printed propellant tank, an MSFC designed propulsion system electronic controller and the 100 mN thruster. In addition to the AF-M315E testing, MSFC is pursuing hot-fire testing with LMP-103S. Following our successful hot-fire testing of the 22N thruster in April 2015, a test campaign was proposed for a 440N LMP-103S thruster with Orbital ATK and Plasma Processes. This activity was funded through the Space Technology Mission Directorate (STMD) ACO funding call in the last quarter of CY15. Under the same funding source a test activity with Busek and Glenn Research Center for testing of 5N AF-M315E thrusters was proposed and awarded. Both activities are in-work with expected completion of hot-fire testing by the end of FY17. MSFC is continuing to coordinate with the AF and academia on understanding the chemical reactions that occur in AF-M315E. An on-going investigation of the catalyst bed species using Raman Spectroscopy through the NASA Technology Research Fellowship Program (NSTRF) is looking for ways to minimize the amount of computation required by understanding the intermediate species created in the catalyst bed. The MSFC team is also working with commercial partners through Cooperative Agreement Notices (CAN's). Partnerships with commercial and academia include work in non-catalytic ignition of AF-M315, spark ignition of hybrid cubesat systems, printed SLM tanks, and dual-mode (electric and chemical) propulsion systems is continuing.

Initial Simulations of RF Waves in Hot Plasmas Using the FullWave Code

NASA Astrophysics Data System (ADS)

Zhao, Liangji; Svidzinski, Vladimir; Spencer, Andrew; Kim, Jin-Soo

2017-10-01

FullWave is a simulation tool that models RF fields in hot inhomogeneous magnetized plasmas. The wave equations with linearized hot plasma dielectric response are solved in configuration space on adaptive cloud of computational points. The nonlocal hot plasma dielectric response is formulated by calculating the plasma conductivity kernel based on the solution of the linearized Vlasov equation in inhomogeneous magnetic field. In an rf field, the hot plasma dielectric response is limited to the distance of a few particles' Larmor radii, near the magnetic field line passing through the test point. The localization of the hot plasma dielectric response results in a sparse matrix of the problem thus significantly reduces the size of the problem and makes the simulations faster. We will present the initial results of modeling of rf waves using the Fullwave code, including calculation of nonlocal conductivity kernel in 2D Tokamak geometry; the interpolation of conductivity kernel from test points to adaptive cloud of computational points; and the results of self-consistent simulations of 2D rf fields using calculated hot plasma conductivity kernel in a tokamak plasma with reduced parameters. Work supported by the US DOE ``SBIR program.

Assessment of hot flushes and vaginal dryness among obese women undergoing bariatric surgery.

PubMed

Goughnour, S L; Thurston, R C; Althouse, A D; Freese, K E; Edwards, R P; Hamad, G G; McCloskey, C; Ramanathan, R; Bovbjerg, D H; Linkov, F

2016-01-01

Menopausal symptoms are associated with a negative impact on the quality of life, leading women to seek medical treatment. Obesity has been linked to higher levels of menopausal symptoms such as hot flushes. This assessment will explore whether the prevalence and bother of hot flushes and vaginal dryness change from pre- to post-bariatric surgery among obese midlife women. This study is a longitudinal analysis of data from 69 women (ages 35-72 years) undergoing bariatric surgery with reported reproductive histories and menopausal symptoms at preoperative and 6-month postoperative visits. Prevalence of and degree of bother of hot flushes and vaginal dryness at pre- and post-surgery were compared using McNemar's test and Wilcoxon signed-rank test. The reported degree of bother of symptoms associated with hot flushes decreased from pre- to post-surgery (p < 0.01). There was no significant change in the prevalence of hot flushes or vaginal dryness in the overall study sample. The degree of bother of symptoms associated with hot flushes among midlife women may decrease after bariatric surgery. These results highlight important secondary gains, including less bothersome menopausal symptoms, for women who choose bariatric surgery for weight loss.

Hot Ductility Behaviors in the Weld Heat-Affected Zone of Nitrogen-Alloyed Fe-18Cr-10Mn Austenitic Stainless Steels

NASA Astrophysics Data System (ADS)

Moon, Joonoh; Lee, Tae-Ho; Hong, Hyun-Uk

2015-04-01

Hot ductility behaviors in the weld heat-affected zone (HAZ) of nitrogen-alloyed Fe-18Cr-10Mn austenitic stainless steels with different nitrogen contents were evaluated through hot tension tests using Gleeble simulator. The results of Gleeble simulations indicated that hot ductility in the HAZs deteriorated due to the formation of δ-ferrite and intergranular Cr2N particles. In addition, the amount of hot ductility degradation was strongly affected by the fraction of δ-ferrite.

Investigation of a Mercury-Argon Hot Cathode Discharge

NASA Astrophysics Data System (ADS)

Wamsley, Robert Charles

Classical absorption and laser induced fluorescence (LIF) experiments are used to investigate processes in the cathode region of a Hg-Ar hot cathode discharge. The absorption and LIF measurements are used to test the qualitative understanding and develop a quantitative model of a hot cathode discharge. The main contribution of this thesis is a model of the negative glow region that demonstrates the importance of Penning ionization to the ionization balance in the negative glow. We modeled the excited argon balance equation using a Monte Carlo simulation. In this simulation we used the trapped radiative decay rate of the resonance levels and the Penning ionization rate as the dominant loss terms in the balance equation. The simulated data is compared to and found to agree with absolute excited argon densities measured in a classical absorption experiment. We found the primary production rate per unit volume of excited Ar atoms in the simulation is sharply peaked near the cathode hot spot. We used the ion production rate from this simulation and a Green's function solution to the ambipolar diffusion equation to calculate the contribution of Penning ionization to the total ion density. We compared the results of this calculation to our experimental values of the Hg ^+ densities in the negative glow. We found that Penning ionization is an important and possibly the dominant ionization process in the negative glow.

Smart SERS Hot Spots: Single Molecules Can Be Positioned in a Plasmonic Nanojunction Using Host-Guest Chemistry.

PubMed

Kim, Nam Hoon; Hwang, Wooseup; Baek, Kangkyun; Rohman, Md Rumum; Kim, Jeehong; Kim, Hyun Woo; Mun, Jungho; Lee, So Young; Yun, Gyeongwon; Murray, James; Ha, Ji Won; Rho, Junsuk; Moskovits, Martin; Kim, Kimoon

2018-04-04

Single-molecule surface-enhanced Raman spectroscopy (SERS) offers new opportunities for exploring the complex chemical and biological processes that cannot be easily probed using ensemble techniques. However, the ability to place the single molecule of interest reliably within a hot spot, to enable its analysis at the single-molecule level, remains challenging. Here we describe a novel strategy for locating and securing a single target analyte in a SERS hot spot at a plasmonic nanojunction. The "smart" hot spot was generated by employing a thiol-functionalized cucurbit[6]uril (CB[6]) as a molecular spacer linking a silver nanoparticle to a metal substrate. This approach also permits one to study molecules chemically reluctant to enter the hot spot, by conjugating them to a moiety, such as spermine, that has a high affinity for CB[6]. The hot spot can accommodate at most a few, and often only a single, analyte molecule. Bianalyte experiments revealed that one can reproducibly treat the SERS substrate such that 96% of the hot spots contain a single analyte molecule. Furthermore, by utilizing a series of molecules each consisting of spermine bound to perylene bisimide, a bright SERS molecule, with polymethylene linkers of varying lengths, the SERS intensity as a function of distance from the center of the hot spot could be measured. The SERS enhancement was found to decrease as 1 over the square of the distance from the center of the hot spot, and the single-molecule SERS cross sections were found to increase with AgNP diameter.

Validation of a Computational Model for the SLS Core Stage Oxygen Tank Diffuser Concept and the Low Profile Diffuser - An Advanced Development Design for the SLS

NASA Technical Reports Server (NTRS)

Brodnick, Jacob; Richardson, Brian; Ramachandran, Narayanan

2015-01-01

The Low Profile Diffuser (LPD) project originated as an award from the Marshall Space Flight Center (MSFC) Advanced Development (ADO) office to the Main Propulsion Systems Branch (ER22). The task was created to develop and test an LPD concept that could produce comparable performance to a larger, traditionally designed, ullage gas diffuser while occupying a smaller volume envelope. Historically, ullage gas diffusers have been large, bulky devices that occupy a significant portion of the propellant tank, decreasing the tank volume available for propellant. Ullage pressurization of spacecraft propellant tanks is required to prevent boil-off of cryogenic propellants and to provide a positive pressure for propellant extraction. To achieve this, ullage gas diffusers must slow hot, high-pressure gas entering a propellant tank from supersonic speeds to only a few meters per second. Decreasing the incoming gas velocity is typically accomplished through expansion to larger areas within the diffuser which has traditionally led to large diffuser lengths. The Fluid Dynamics Branch (ER42) developed and applied advanced Computational Fluid Dynamics (CFD) analysis methods in order to mature the LPD design from and initial concept to an optimized test prototype and to provide extremely accurate pre-test predictions of diffuser performance. Additionally, the diffuser concept for the Core Stage of the Space Launch System (SLS) was analyzed in a short amount of time to guide test data collection efforts of the qualification of the device. CFD analysis of the SLS diffuser design provided new insights into the functioning of the device and was qualitatively validated against hot wire anemometry of the exterior flow field. Rigorous data analysis of the measurements was performed on static and dynamic pressure data, data from two microphones, accelerometers and hot wire anemometry with automated traverse. Feasibility of the LPD concept and validation of the computational model were demonstrated by the test data.

Functional Roles of Acetylated Histone Marks at Mouse Meiotic Recombination Hot Spots

PubMed Central

Wu, Zhen; Fallahi, Mohammad; Ouizem, Souad; Liu, Qin; Li, Weimin; Costi, Roberta; Roush, William R.; Bois, Philippe R. J.

2016-01-01

ABSTRACT Meiotic recombination initiates following the formation of DNA double-strand breaks (DSBs) by the Spo11 endonuclease early in prophase I, at discrete regions in the genome coined “hot spots.” In mammals, meiotic DSB site selection is directed in part by sequence-specific binding of PRDM9, a polymorphic histone H3 (H3K4Me3) methyltransferase. However, other chromatin features needed for meiotic hot spot specification are largely unknown. Here we show that the recombinogenic cores of active hot spots in mice harbor several histone H3 and H4 acetylation and methylation marks that are typical of open, active chromatin. Further, deposition of these open chromatin-associated histone marks is dynamic and is manifest at spermatogonia and/or pre-leptotene-stage cells, which facilitates PRDM9 binding and access for Spo11 to direct the formation of DSBs, which are initiated at the leptotene stage. Importantly, manipulating histone acetylase and deacetylase activities established that histone acetylation marks are necessary for both hot spot activity and crossover resolution. We conclude that there are functional roles for histone acetylation marks at mammalian meiotic recombination hot spots. PMID:27821479

Manufacture of low carbon astroloy turbine disk shapes by hot isostatic pressing. Volume 2, project 1

NASA Technical Reports Server (NTRS)

Eng, R. D.; Evans, D. J.

1979-01-01

The performance of a hot isotatic pressed disk installed in an experimental engine and exposed to realistic operating conditions in a 150-hour engine test and a 1000 cycle endurance test is documented. Post test analysis, based on visual, fluorescent penetrant and dimensional inspection, revealed no defects in the disk and indicated that the disk performed satisfactorily.

Hot cracking susceptibility of fillers 52 and 82 in alloy 690 welding

NASA Astrophysics Data System (ADS)

Wu, Weite; Tsai, C. H.

1999-02-01

The hot cracking susceptibility of fillers 52 and 82 in a alloy 690 weldment is analyzed by the Varestraint test. Weld characteristics, microstructure, hardness distribution, and thermal analysis of the two filler metals are also examined. The weld metal of both fillers develops an extremely dense oxide layer. A stainless steel brush cannot remove the oxide layer, and a grinder may be needed between weld passes to assure a sound weld. Differential temperature analysis (DTA) shows that filler 82 has a lower melting point and a wider melting/solidification temperature differential (Δ T). These characteristics correlate with greater hot cracking susceptibility of filler 82 than 52 in Varestraint tests. The hot cracks are intergranular and are caused by elements segregating in grain boundies.

Overview of Current Hot Water Propulsion Activities at Berlin University of Technology

NASA Astrophysics Data System (ADS)

Kolditz, M.; Pilz, N.; Adirim, H.; Rudloff, P.; Gorsch, M.; Kron, M.

2004-10-01

The AQUARIUS working group has been founded in 1991 on the initiative of students at the Institute of Aeronautics and Astronautics at Berlin University of Technology. It works mainly on the development, manufacturing and testing of hot water propulsion systems. Upon having launched numerous single stage rockets, a two stage hot water rocket (AQUARIUS X-PRO) was developed and launched for the first time in world history. In order to perform thrust experiments for a deeper understanding of the propulsion efficiency and the influence of varying nozzle parameters on exhaust characteristics, a dedicated hot water test facility has been built. For more than five years,ground-based take-off assistance systems for future reusable launch vehicles have been the subject of intense investigation.

Controlled-Temperature Hot-Air Gun

NASA Technical Reports Server (NTRS)

Munoz, M. C.

1986-01-01

Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

Genome-wide identification and characterisation of HOT regions in the human genome.

PubMed

Li, Hao; Liu, Feng; Ren, Chao; Bo, Xiaochen; Shu, Wenjie

2016-09-15

HOT (high-occupancy target) regions, which are bound by a surprisingly large number of transcription factors, are considered to be among the most intriguing findings of recent years. An improved understanding of the roles that HOT regions play in biology would be afforded by knowing the constellation of factors that constitute these domains and by identifying HOT regions across the spectrum of human cell types. We characterised and validated HOT regions in embryonic stem cells (ESCs) and produced a catalogue of HOT regions in a broad range of human cell types. We found that HOT regions are associated with genes that control and define the developmental processes of the respective cell and tissue types. We also showed evidence of the developmental persistence of HOT regions at primitive enhancers and demonstrate unique signatures of HOT regions that distinguish them from typical enhancers and super-enhancers. Finally, we performed a dynamic analysis to reveal the dynamical regulation of HOT regions upon H1 differentiation. Taken together, our results provide a resource for the functional exploration of HOT regions and extend our understanding of the key roles of HOT regions in development and differentiation.

Hot Ductility and Compression Deformation Behavior of TRIP980 at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Zhang, Mei; Li, Haiyang; Gan, Bin; Zhao, Xue; Yao, Yi; Wang, Li

2018-02-01

The hot ductility tests of a kind of 980 MPa class Fe-0.31C (wt pct) TRIP steel (TRIP980) with the addition of Ti/V/Nb were conducted on a Gleeble-3500 thermomechanical simulator in the temperatures ranging from 873 K to 1573 K (600 °C to 1300 °C) at a constant strain rate of 0.001 s-1. It is found that the hot ductility trough ranges from 873 K to 1123 K (600 °C to 850 °C). The recommended straightening temperatures are from 1173 K to 1523 K (900 °C to 1250 °C). The isothermal hot compression deformation behavior was also studied by means of Gleeble-3500 in the temperatures ranging from 1173 K to 1373 K (900 °C to 1100 °C) at strain rates ranging from 0.01 s-1 to 10 s-1. The results show that the peak stress decreases with the increasing temperature and the decreasing strain rate. The deformation activation energy of the test steel is 436.7 kJ/mol. The hot deformation equation of the steel has been established, and the processing maps have been developed on the basis of experimental data and the principle of dynamic materials model (DMM). By analyzing the processing maps of strains of 0.5, 0.7, and 0.9, it is found that dynamic recrystallization occurs in the peak power dissipation efficiency domain, which is the optimal area of hot working. Finally, the factors influencing hot ductility and thermal activation energy of the test steel were investigated by means of microscopic analysis. It indicates that the additional microalloying elements play important roles both in the loss of hot ductility and in the enormous increase of deformation activation energy for the TRIP980 steel.

Low-temperature bonded glass-membrane microfluidic device for in vitro organ-on-a-chip cell culture models

NASA Astrophysics Data System (ADS)

Pocock, Kyall J.; Gao, Xiaofang; Wang, Chenxi; Priest, Craig; Prestidge, Clive A.; Mawatari, Kazuma; Kitamori, Takehiko; Thierry, Benjamin

2015-12-01

The integration of microfluidics with living biological systems has paved the way to the exciting concept of "organson- a-chip", which aims at the development of advanced in vitro models that replicate the key features of human organs. Glass based devices have long been utilised in the field of microfluidics but the integration of alternative functional elements within multi-layered glass microdevices, such as polymeric membranes, remains a challenge. To this end, we have extended a previously reported approach for the low-temperature bonding of glass devices that enables the integration of a functional polycarbonate porous membrane. The process was initially developed and optimised on specialty low-temperature bonding equipment (μTAS2001, Bondtech, Japan) and subsequently adapted to more widely accessible hot embosser units (EVG520HE Hot Embosser, EVG, Austria). The key aspect of this method is the use of low temperatures compatible with polymeric membranes. Compared to borosilicate glass bonding (650 °C) and quartz/fused silica bonding (1050 °C) processes, this method maintains the integrity and functionality of the membrane (Tg 150 °C for polycarbonate). Leak tests performed showed no damage or loss of integrity of the membrane for up to 150 hours, indicating sufficient bond strength for long term cell culture. A feasibility study confirmed the growth of dense and functional monolayers of Caco-2 cells within 5 days.

Low-temperature bonding process for the fabrication of hybrid glass-membrane organ-on-a-chip devices

NASA Astrophysics Data System (ADS)

Pocock, Kyall J.; Gao, Xiaofang; Wang, Chenxi; Priest, Craig; Prestidge, Clive A.; Mawatari, Kazuma; Kitamori, Takehiko; Thierry, Benjamin

2016-10-01

The integration of microfluidics with living biological systems has paved the way to the exciting concept of "organs-on-a-chip," which aims at the development of advanced in vitro models that replicate the key features of human organs. Glass-based devices have long been utilized in the field of microfluidics but the integration of alternative functional elements within multilayered glass microdevices, such as polymeric membranes, remains a challenge. To this end, we have extended a previously reported approach for the low-temperature bonding of glass devices that enables the integration of a functional polycarbonate porous membrane. The process was initially developed and optimized on specialty low-temperature bonding equipment (μTAS2001, Bondtech, Japan) and subsequently adapted to more widely accessible hot embosser units (EVG520HE Hot Embosser, EVG, Austria). The key aspect of this method is the use of low temperatures compatible with polymeric membranes. Compared to borosilicate glass bonding (650°C) and quartz/fused silica bonding (1050°C) processes, this method maintains the integrity and functionality of the membrane (Tg 150°C for polycarbonate). Leak tests performed showed no damage or loss of integrity of the membrane for up to 150 h, indicating sufficient bond strength for long-term cell culture. A feasibility study confirmed the growth of dense and functional monolayers of Caco-2 cells within 5 days.

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

Eric Larsen; Art Watkins; Timothy R. McJunkin

The U.S. Department of Energy (DOE) created the National Spent Nuclear Fuel Program (NSNFP) to manage DOE’s spent nuclear fuel (SNF). One of the NSNFP’s tasks is to prepare spent nuclear fuel for storage, transportation, and disposal at the national repository. As part of this effort, the NSNFP developed a standardized canister for interim storage and transportation of SNF. These canisters will be built and sealed to American Society of Mechanical Engineers (ASME) Section III, Division 3 requirements. Packaging SNF usually is a three-step process: canister loading, closure welding, and closure weld verification. After loading SNF into the canisters, themore » canisters must be seal welded and the welds verified using a combination of visual, surface eddy current, and ultrasonic inspection or examination techniques. If unacceptable defects in the weld are detected, the defective sections of weld must be removed, re-welded, and re-inspected. Due to the high contamination and/or radiation fields involved with this process, all of these functions must be performed remotely in a hot cell. The prototype apparatus to perform these functions is a floor-mounted carousel that encircles the loaded canister; three stations perform the functions of welding, inspecting, and repairing the seal welds. A welding operator monitors and controls these functions remotely via a workstation located outside the hot cell. The discussion describes the hardware and software that have been developed and the results of testing that has been done to date.« less

High gas velocity oxidation and hot corrosion testing of oxide dispersion-strengthened nickel-base alloys

NASA Technical Reports Server (NTRS)

Deadmore, D. L.; Lowell, C. E.

1975-01-01

Several oxide dispersion strengthened (ODS) nickel-base alloys were tested in high velocity gases for cyclic oxidation resistance at temperatures to 1200 C and times to 500 hours and for hot corrosion resistance at 900 C for 200 hours. Nickel-chromium-aluminum ODS alloys were found to have superior resistance to oxidation and hot corrosion when compared to bare and coated nickel-chromium ODS alloys. The best of the alloys tested had compositions of nickel - 15.5 to 16 weight percent chromium with aluminum weight percents between 4.5 and 5.0. All of the nickel-chromium-aluminum ODS materials experienced small weight losses (less than 16 mg/sq cm).

A unique high heat flux facility for testing hypersonic engine components

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Gladden, Herbert J.

1990-01-01

This paper describes the Hot Gas Facility, a unique, reliable, and cost-effective high-heat-flux facility for testing hypersonic engine components developed at the NASA Lewis Research Center. The Hot Gas Facility is capable of providing heat fluxes ranging from 200 Btu/sq ft per sec on flat surfaces up to 8000 Btu/sq ft per sec at a leading edge stagnation point. The usefulness of the Hot Gas Facility for the NASP community was demonstrated by testing hydrogen-cooled structures over a range of temperatures and pressures. Ranges of the Reynolds numbers, Prandtl numbers, enthalpy, and heat fluxes similar to those expected during hypersonic flights were achieved.

Cold Helium Pressurization for Liquid Oxygen / Liquid Methane Propulsion Systems: Fully-Integrated Initial Hot-Fire Test Results

NASA Technical Reports Server (NTRS)

Morehead, R. L.; Atwell, M. J.; Melcher, J. C.; Hurlbert, E. A.

2016-01-01

A prototype cold helium active pressurization system was incorporated into an existing liquid oxygen (LOX) / liquid methane (LCH4) prototype planetary lander and hot-fire tested to collect vehicle-level performance data. Results from this hot-fire test series were used to validate integrated models of the vehicle helium and propulsion systems and demonstrate system effectiveness for a throttling lander. Pressurization systems vary greatly in complexity and efficiency between vehicles, so a pressurization performance metric was also developed as a means to compare different active pressurization schemes. This implementation of an active repress system is an initial sizing draft. Refined implementations will be tested in the future, improving the general knowledge base for a cryogenic lander-based cold helium system.

The Effects of Hot Corrosion Pits on the Fatigue Resistance of a Disk Superalloy

NASA Technical Reports Server (NTRS)

Gabb, Timothy P.; Telesman, Jack; Hazel, Brian; Mourer, David P.

2009-01-01

The effects of hot corrosion pits on low cycle fatigue life and failure modes of the disk superalloy ME3 were investigated. Low cycle fatigue specimens were subjected to hot corrosion exposures producing pits, then tested at low and high temperatures. Fatigue lives and failure initiation points were compared to those of specimens without corrosion pits. Several tests were interrupted to estimate the fraction of fatigue life that fatigue cracks initiated at pits. Corrosion pits significantly reduced fatigue life by 60 to 98 percent. Fatigue cracks initiated at a very small fraction of life for high temperature tests, but initiated at higher fractions in tests at low temperature. Critical pit sizes required to promote fatigue cracking were estimated, based on measurements of pits initiating cracks on fracture surfaces.

Study on the influence of three-grid assembly thermal deformation on breakdown times and an ion extraction process

NASA Astrophysics Data System (ADS)

Mingming, SUN; Yanhui, JIA; Yongjie, HUANG; Juntai, YANG; Xiaodong, WEN; Meng, WANG

2018-04-01

In order to study the influence of three-grid assembly thermal deformation caused by heat accumulation on breakdown times and an ion extraction process, a hot gap test and a breakdown time test are carried out to obtain thermal deformation of the grids when the thruster is in 5 kW operation mode. Meanwhile, the fluid simulation method and particle-in-cell-Monte Carlo collision (PIC-MCC) method are adopted to simulate the ion extraction process according to the previous test results. The numerical calculation results are verified by the ion thruster performance test. The results show that after about 1.2 h operation, the hot gap between the screen grid and the accelerator grid reduce to 0.25–0.3 mm, while the hot gap between the accelerator grid and the decelerator grid increase from 1 mm to about 1.4 mm when the grids reach thermal equilibrium, and the hot gap is almost unchanged. In addition, the breakdown times experiment shows that 0.26 mm is the minimal safe hot gap for the grid assembly as the breakdown times improves significantly when the gap is smaller than this value. Fluid simulation results show that the plasma density of the screen grid is in the range 6 × 1017–6 × 1018 m13 and displays a parabolic characteristic, while the electron temperature gradually increases along the axial direction. The PIC-MCC results show that the current falling of an ion beam through a single aperture is significant. Meanwhile, the intercepted current of the accelerator grid and the decelerator grid both increase with the change in the hot gap. The ion beam current has optimal perveance status without thermal deformation, and the intercepted current of the accelerator grid and the decelerator grid are 3.65 mA and 6.26 mA, respectively. Furthermore, under the effect of thermal deformation, the ion beam current has over-perveance status, and the intercepted current of the accelerator grid and the decelerator grid are 10.46 mA and 18.24 mA, respectively. Performance test results indicate that the breakdown times increase obviously. The intercepted current of the accelerator grid and the decelerator grid increases to 13 mA and 16.5 mA, respectively, due to the change in the hot gap after 1.5 h operation. The numerical calculation results are well consistent with performance test results, and the error comes mainly from the test uncertainty of the hot gap.

Hot Corrosion of Single-Crystal NiAl-X Alloys

NASA Technical Reports Server (NTRS)

Nesbitt, James A.

1998-01-01

Several single-crystal NiAl-X alloys (X=Hf, Ti, Cr, Ga) underwent hot corrosion testing in a Mach 0.3 burner rig at 900 deg. C for 300 1-hr cycles. The surface morphology after testing consisted of either mounds or an inward, uniform-type of attack which preserved surface features. It was observed that the surface morphology was affected by the surface preparation treatments. Microstructurally, the hot corrosion attack initiated as pits but evolved to a rampant attack consisting of the rapid inward growth of Al2O3. Electropolishing and chemical milling produced many pits and grooves on the surface. However, the presence of pits and grooves did not appear to strongly influence the hot corrosion response. Attack on many samples was strongly localized which was attributed to compositional inhomogeneity within the samples. It was found that increasing the Ti content from 1% to 5 % degraded the hot corrosion response of these alloys. In contrast, the addition of 1-2% Cr reduced the susceptibility of these alloys to hot corrosion attack and negated the deleterious effect of the 4-5% Ti addition.

Using hot lab to increase pre-service physics teacher’s critical thinking skills related to the topic of RLC circuit

NASA Astrophysics Data System (ADS)

Malik, A.; Setiawan, A.; Suhandi, A.; Permanasari, A.; Samsudin, A.; Safitri, D.; Lisdiani, S. A. S.; Sapriadil, S.; Hermita, N.

2018-05-01

This research purposes to explore the used of Higher Order Thinking Laboratory (HOT-Lab) in enhancing the critical thinking skills of pre-service teachers related to the topic of Resistors, Inductors, Capacitor (RLC circuit). This study utilised a quasi-experiment method with Pretest-Posttest Control Group design. The sample of the study was 60 students that were divided into two groups covering in experiment and control group, consists of 30 students. The instrument for measuring critical thinking skills is essay test. Data has been analyzed using normalized gain average, effect size, and t-test. The results show that students’ critical thinking skills using the HOT Lab are higher than the verification lab. Using HOT-lab was implemented in the form of activity in the laboratory can improve high-order thinking skills. Hence, it was concluded that the use of HOT Lab had a greater impact on improving students’ critical thinking skills on RLC topic. Finally, HOT Lab can be used for other physics topics.

Risk Factors, Pathophysiology, and Treatment of Hot Flashes in Cancer

PubMed Central

Fisher, William I.; Johnson, Aimee K.; Elkins, Gary R.; Otte, Julie L.; Burns, Debra S.; Yu, Menggang; Carpenter, Janet S.

2012-01-01

Hot flashes are prevalent and severe symptoms that can interfere with mood, sleep, and quality of life for women and men with cancer. The purpose of this article is to review existing literature on the risk factors, pathophysiology, and treatment of hot flashes in persons with cancer. Electronic searches were conducted to identify relevant, English-language literature published through June 15, 2012. Results indicated that risk factors for hot flashes in cancer include patient-related factors (eg, age, race/ethnicity, educational level, smoking history, cardiovascular risk including BMI, and genetics) and disease-related factors (eg, cancer diagnosis, and dose/type of treatment). In addition, although the pathophysiology of hot flashes has remained elusive, these symptoms are likely attributable to disruptions in thermoregulation and neurochemicals. Therapies that have been offered or tested fall into 4 broad categories: pharmacological, nutraceutical, surgical, and complementary/behavioral strategies. The evidence base for this broad range of therapies varies, with some treatments not yet having been fully tested or showing equivocal results. The evidence base surrounding all therapies is evaluated to enhance hot flash treatment decision making by clinicians and patients. PMID:23355109

A Versatile Rocket Engine Hot Gas Facility

NASA Technical Reports Server (NTRS)

Green, James M.

1993-01-01

The capabilities of a versatile rocket engine facility, located in the Rocket Laboratory at the NASA Lewis Research Center, are presented. The gaseous hydrogen/oxygen facility can be used for thermal shock and hot gas testing of materials and structures as well as rocket propulsion testing. Testing over a wide range of operating conditions in both fuel and oxygen rich regimes can be conducted, with cooled or uncooled test specimens. The size and location of the test cell provide the ability to conduct large amounts of testing in short time periods with rapid turnaround between programs.

On the characteristics of caloric nystagmus in healthy persons. [in response to caloric stimuli

NASA Technical Reports Server (NTRS)

Bodo, D.; Baranova, V. P.; Matsnev, E. I.; Yakovleva, M. Y.

1974-01-01

The asymmetry of reflex activity of labyrinths and directional preponderance of the reaction were studied on healthy persons subjected to caloric tests. Calorization with hot water was accompanied by less pronounced reactions in all parameters of nystagmus than analogous indices at cold water stimulation. The symmetry of labyrinth function shifted to the right in individuals with greater activity of the left central vestibular formations, analogous to right handedness behavior. It is concluded that asymmetry of reflex nystagmus in healthy persons can be due to a certain preponderance of functional activity in structures of the left hemisphere of the brain.

Visualizing Stress and Temperature Distribution During Elevated Temperature Deformation of IN-617 Using Nanomechanical Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Zhang, Yang; Wang, Hao; Tomar, Vikas

2018-04-01

This work presents direct measurements of stress and temperature distribution during the mesoscale microstructural deformation of Inconel-617 (IN-617) during 3-point bending tests as a function of temperature. A novel nanomechanical Raman spectroscopy (NMRS)-based measurement platform was designed for simultaneous in situ temperature and stress mapping as a function of microstructure during deformation. The temperature distribution was found to be directly correlated to stress distribution for the analyzed microstructures. Stress concentration locations are shown to be directly related to higher heat conduction and result in microstructural hot spots with significant local temperature variation.

A feature-based approach to modeling protein-protein interaction hot spots.

PubMed

Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

2009-05-01

Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to pi-related interactions, especially pi . . . pi interactions.

Hot piston ring/cylinder liner materials: Selection and evaluation

NASA Technical Reports Server (NTRS)

Sliney, Harold E.

1988-01-01

In current designs of the automotive (kinematic) Stirling engine, the piston rings are made of a reinforced polymer and are located below the pistons because they cannot withstand the high temperatures in the upper cylinder area. Theoretically, efficiency could be improved if hot piston rings were located near the top of the pistons. Described is a program to select piston ring and cylinder coating materials to test this theory. Candidate materials were screened, then subjected to a pin or disk friction and wear test machine. Tests were performed in hydrogen at specimen temperatures up to 760 C to simulate environmental conditions in the region of the hot piston ring reversal. Based on the results of these tests, a cobalt based alloy, Stellite 6B, was chosen for the piston rings and PS200, which consists of a metal-bonded chromium carbide matrix with dispersed solid lubricants, was chosen as the cylinder coating. Tests of a modified engine and a baseline engine showed that the hot ring reduced specific fuel consumption by up to 7 percent for some operating conditions and averaged about 3 percent for all conditions evaluated. Related applications of high-temperature coatings for shaft seals and as back-up lubricants are also described.

Summary of LOX/CH4 Thruster Technology Development at NASA/MSFC

NASA Technical Reports Server (NTRS)

Greene, Sandra Elam

2015-01-01

In recent years, a variety of injectors for liquid oxygen (LOX) and methane (CH4) propellant systems have been designed, fabricated, and demonstrated with hot-fire testing at Marshall Space Flight Center (MSFC). Successful designs for liquid methane (LCH4) and gaseous methane (GCH4) have been developed. A variety of chambers, including a transpiration cooled design, along with uncooled ablatives and refractory metals, have also been hot-fire tested by MSFC for use with LOX/LCH4 injectors. Hot-fire testing has also demonstrated multiple ignition source options. Heat flux data for selected injectors has been gathered by testing with a calorimeter chamber. High performance and stable combustion have been demonstrated, along with designs for thrust levels ranging from 500 to 7,000 lbf. The newest LOX/CH4 injector and chamber developed by MSFC have been fabricated with additive manufacturing techniques and include unique design features to investigate regenerative cooling with methane. This low cost and versatile hardware offers a design for 4,000 lbf thrust and will be hot-fire tested at MSFC in 2015. Its design and operation can easily be scaled for use in systems with thrust levels up to 25,000 lbf.

HOT CELL BUILDING, TRA632. ELEVATIONS FOR SOUTH, NORTH AND WEST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. ELEVATIONS FOR SOUTH, NORTH AND WEST SIDES OF 1958 EXTENSION. H.K. FERGUSON CO. 895-MTR-ETR-632-A3, 12/1958. INL INDEX NO. 531-0632-00-279-101926, REV. 3. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

A comparison of dynamic mechanical properties of processing-tomato peel as affected by hot lye and infrared radiation heating for peeling

USDA-ARS?s Scientific Manuscript database

This study investigated the viscoelastic characteristics of tomato skins subjected to conventional hot lye peeling and emerging infrared-dry peeling by using dynamic mechanical analysis (DMA). Three DMA testing modes, including temperature ramp, frequency sweep, and creep behavior test, were conduct...

HOT CELL BUILDING, TRA632, INTERIOR. CELL 3, "HEAVY" CELL. CAMERA ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. CELL 3, "HEAVY" CELL. CAMERA FACES WEST TOWARD BUILDING EXIT. OBSERVATION WINDOW AT LEFT EDGE OF VIEW. INL NEGATIVE NO. HD46-28-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Additively Manufactured Combustion Devices Components for LOX/Methane Applications

NASA Technical Reports Server (NTRS)

Greene, Sandra Elam; Protz, Christopher; Garcia, Chance; Goodman, Dwight; Baker, Kevin

2016-01-01

Marshall Space Flight Center (MSFC) has designed, fabricated, and hot-fire tested a variety of successful injectors, chambers, and igniters for potential liquid oxygen (LOX) and methane (CH4) systems since 2005. The most recent efforts have focused on components with additive manufacturing (AM) to include unique design features, minimize joints, and reduce final machining efforts. Inconel and copper alloys have been used with AM processes to produce a swirl coaxial injector and multiple methane cooled thrust chambers. The initial chambers included unique thermocouple ports for measuring local coolant channel temperatures along the length of the chamber. Results from hot-fire testing were used to anchor thermal models and generate a regeneratively cooled thruster for a 4,000 lbf LOX/CH4 engine. The completed thruster will be hot-fire tested in the summer of 2016 at MSFC. The thruster design can also be easily scaled and used on a 25,000 lbf engine. To further support the larger engine design, an AM gas generator injector has been designed. Hot-fire testing on this injector is planned for the summer of 2016 at MSFC.

Solvent-accessible surface area: How well can be applied to hot-spot detection?

PubMed

Martins, João M; Ramos, Rui M; Pimenta, António C; Moreira, Irina S

2014-03-01

A detailed comprehension of protein-based interfaces is essential for the rational drug development. One of the key features of these interfaces is their solvent accessible surface area profile. With that in mind, we tested a group of 12 SASA-based features for their ability to correlate and differentiate hot- and null-spots. These were tested in three different data sets, explicit water MD, implicit water MD, and static PDB structure. We found no discernible improvement with the use of more comprehensive data sets obtained from molecular dynamics. The features tested were shown to be capable of discerning between hot- and null-spots, while presenting low correlations. Residue standardization such as rel SASAi or rel/res SASAi , improved the features as a tool to predict ΔΔGbinding values. A new method using support machine learning algorithms was developed: SBHD (Sasa-Based Hot-spot Detection). This method presents a precision, recall, and F1 score of 0.72, 0.81, and 0.76 for the training set and 0.91, 0.73, and 0.81 for an independent test set. Copyright © 2013 Wiley Periodicals, Inc.

Reducing tool wear by partial cladding of critical zones in hot form tool by laser metal deposition

NASA Astrophysics Data System (ADS)

Vollmer, Robert; Sommitsch, Christof

2017-10-01

This paper points out a production method to reduce tool wear in hot stamping applications. Usually tool wear can be observed at locally strongly stressed areas superimposed with gliding movement between blank and tool surface. The shown solution is based on a partial laser cladding of the tool surface with a wear resistant coating to increase the lifespan of tool inserts. Preliminary studies showed good results applying a material combination of tungsten carbide particles embedded in a metallic matrix. Different Nickel based alloys welded on hot work tool steel (1.2343) were tested mechanically in the interface zone. The material with the best bonding characteristic is chosen and reinforced with spherical tungsten carbide particles in a second laser welding step. Since the machining of tungsten carbides is very elaborate a special manufacturing strategy is developed to reduce the milling effort as much as possible. On special test specimens milling tests are carried out to proof the machinability. As outlook a tool insert of a b-pillar is coated to perform real hot forming tests.

Developmental trends of hot and cool executive function in school-aged children with and without autism spectrum disorder: Links with theory of mind.

PubMed

Kouklari, Evangelia-Chrysanthi; Tsermentseli, Stella; Monks, Claire P

2018-03-26

The development of executive function (EF) in autism spectrum disorder (ASD) has been investigated using only "cool"-cognitive EF tasks while there is limited knowledge regarding the development of "hot"-affective EF. Although cool EF development and its links to theory of mind (ToM) have been widely examined, understanding of the influence of hot EF to ToM mechanisms is minimal. The present study introduced a longitudinal design to examine the developmental changes in cool and hot EF of children with ASD (n = 45) and matched (to age and IQ) controls (n = 37) as well as the impact of EF on ToM development over a school year. For children with ASD, although selective cool (working memory and inhibition) and hot (affective decision making) EF domains presented age-related improvements, they never reached the performance level of the control group. Early cool working memory predicted later ToM in both groups but early hot delay discounting predicted later ToM only in the ASD group. No evidence was found for the reverse pattern (early ToM predicting later EF). These findings suggest that improvements in some EF aspects are evident in school age in ASD and highlight the crucial role that both cool and hot EF play in ToM development.

Time to B. cereus about hot chocolate.

PubMed Central

Nelms, P K; Larson, O; Barnes-Josiah, D

1997-01-01

OBJECTIVE: To determine the cause of illnesses experienced by employees of a Minneapolis manufacturing plant after drinking hot chocolate bought from a vending machine and to explore the prevalence of similar vending machine-related illnesses. METHODS: The authors inspected the vending machines at the manufacturing plant where employees reported illnesses and at other locations in the city where hot chocolate beverages were sold in machines. Tests were performed on dry mix, water, and beverage samples and on machine parts. RESULTS: Laboratory analyses confirmed the presence of B. cereus in dispensed beverages at a concentration capable of causing illness (170,000 count/gm). In citywide testing of vending machines dispensing hot chocolate, 7 of the 39 licensed machines were found to be contaminated, with two contaminated machines having B. cereus levels capable of causing illness. CONCLUSIONS: Hot chocolate sold in vending machines may contain organisms capable of producing toxins that under favorable conditions, can induce illness. Such illnesses are likely to be underreported. Even low concentrations of B. cereus may be dangerous for vulnerable populations such as the aged or immunosuppressed. Periodic testing of vending machines is thus warranted. The relationship between cleaning practices and B. cereus contamination is an issue for further study. PMID:9160059

Time to B. cereus about hot chocolate.

PubMed

Nelms, P K; Larson, O; Barnes-Josiah, D

1997-01-01

To determine the cause of illnesses experienced by employees of a Minneapolis manufacturing plant after drinking hot chocolate bought from a vending machine and to explore the prevalence of similar vending machine-related illnesses. The authors inspected the vending machines at the manufacturing plant where employees reported illnesses and at other locations in the city where hot chocolate beverages were sold in machines. Tests were performed on dry mix, water, and beverage samples and on machine parts. Laboratory analyses confirmed the presence of B. cereus in dispensed beverages at a concentration capable of causing illness (170,000 count/gm). In citywide testing of vending machines dispensing hot chocolate, 7 of the 39 licensed machines were found to be contaminated, with two contaminated machines having B. cereus levels capable of causing illness. Hot chocolate sold in vending machines may contain organisms capable of producing toxins that under favorable conditions, can induce illness. Such illnesses are likely to be underreported. Even low concentrations of B. cereus may be dangerous for vulnerable populations such as the aged or immunosuppressed. Periodic testing of vending machines is thus warranted. The relationship between cleaning practices and B. cereus contamination is an issue for further study.

Application of High Speed Digital Image Correlation in Rocket Engine Hot Fire Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Schmidt, Tim

2016-01-01

Hot fire testing of rocket engine components and rocket engine systems is a critical aspect of the development process to understand performance, reliability and system interactions. Ground testing provides the opportunity for highly instrumented development testing to validate analytical model predictions and determine necessary design changes and process improvements. To properly obtain discrete measurements for model validation, instrumentation must survive in the highly dynamic and extreme temperature application of hot fire testing. Digital Image Correlation has been investigated and being evaluated as a technique to augment traditional instrumentation during component and engine testing providing further data for additional performance improvements and cost savings. The feasibility of digital image correlation techniques were demonstrated in subscale and full scale hotfire testing. This incorporated a pair of high speed cameras to measure three-dimensional, real-time displacements and strains installed and operated under the extreme environments present on the test stand. The development process, setup and calibrations, data collection, hotfire test data collection and post-test analysis and results are presented in this paper.

Solar-energy heats a transportation test center--Pueblo, Colorado

NASA Technical Reports Server (NTRS)

1981-01-01

Petroleum-base, thermal energy transport fluid circulating through 583 square feet of flat-plate solar collectors accumulates majority of energy for space heating and domestic hot-water of large Test Center. Report describes operation, maintenance, and performance of system which is suitable for warehouses and similar buildings. For test period from February 1979 to January 1980, solar-heating fraction was 31 percent, solar hot-water fraction 79 percent.

Searching for biogeochemical hot spots in three dimensions: soil C and N cycling in hydropedologic settings in a northern hardwood forest

Treesearch

J.L. Morse; S.F. Werner; C.P. Gillin; C.L. Goodale; S.W. Bailey; K.J. McGuire; P.M. Groffman

2014-01-01

Understanding and predicting the extent, location, and function of biogeochemical hot spots at the watershed scale is a frontier in environmental science. We applied a hydropedologic approach to identify (1) biogeochemical differences among morphologically distinct hydropedologic settings and (2) hot spots of microbial carbon (C) and nitrogen (N) cycling activity in a...

Evaluation of the antinociceptive activities of enaminone compounds on the formalin and hot plate tests in mice

NASA Astrophysics Data System (ADS)

Masocha, Willias; Kombian, Samuel B.; Edafiogho, Ivan O.

2016-02-01

Recently, we found that methyl 4-(4‧-bromophenyl)aminocyclohex-3-en-6-methyl-2-oxo-1-oate (E139), an anticonvulsant enaminone, has antinociceptive activity in the hot plate test. In this study we evaluated the antinociceptive activity of five anilino enaminones E139, ethyl 4-(4‧-chlorophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (E121), ethyl 4-(4‧-bromophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (E122), methyl 4-(4‧-chlorophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (E138) and ethyl 4-(4‧-fluorophenyl)amino-6-methyl-2-oxocyclohex-3-en-1-oate (BRG 19) using the formalin and hot plate tests. E139 has been reported to exert its effects via enhancement of extracellular GABA levels, thus tiagabine, a GABA transporter inhibitor, was evaluated as a control together with indomethacin. Tiagabine had antinociceptive activity in both phase 1 (neurogenic pain) and phase 2 (inflammatory pain) of the formalin test, whereas indomethacin had activity only in phase 2. E139 and E138 had antinociceptive activity in both phases of the formalin test, whereas E121 had activity only in phase 1 and BRG 19 had activity only in phase 2. E122 had no significant activity in either phase. In the hot plate test only E139 had antinociceptive activity. Administration of either bicuculline, a GABAA receptor antagonist, or CGP 35348, a GABAB receptor antagonist, blocked the antinociceptive activity of E139. In conclusion our results indicate that E139 has antinociceptive activity in the formalin and hot plate tests that are dependent on GABA receptors.

Predicting melt rheology for hot-melt extrusion by means of a simple Tg-measurement.

PubMed

Bochmann, Esther S; Üstüner, Elgin E; Gryczke, Andreas; Wagner, Karl G

2017-10-01

The feasibility of predicting melt rheology by using the glass transition temperature (T g ) of a desired amorphous solid dispersion (ASD) for hot-melt extrusion (HME) and other melt based processes is presented. Three groups of three different active pharmaceutical ingredients (APIs) or plasticizer/copovidone mixtures, with identical glass transition in rheological testing, were used. Their rheological behavior as a function of temperature and frequency were analyzed by means of small amplitude oscillatory shear (SAOS) on an oscillatory rheometer. The zero-shear viscosity (η 0 ) identified at 150°C was compared to T g , measured by differential scanning calorimetry (DSC) and SAOS. A strong correlation between η 0 and T g was identified, independent of the API or plasticizer used to achieve T g of the mixture. To evaluate and rate the discrepancy in η 0 of the different mixtures at same T g , hot-melt extrusion trials were conducted to measure torque and mean residence time. In this paper, carbamazepine, dipyridamole, indomethacin, ibuprofen, polyethylene glycol (PEG 1500) in vinylpyrrolidone-vinyl acetate copolymer (copovidone) as matrix polymer were used. Copyright © 2017. Published by Elsevier B.V.

Efficacy of Common Analgesics for Postsurgical Pain in Rats

PubMed Central

Waite, Megan E; Tomkovich, Ashleigh; Quinn, Tammie L; Schumann, Alan P; Dewberry, L Savannah; Totsch, Stacie K; Sorge, Robert E

2015-01-01

Each year, millions of rats undergo surgery for research purposes and receive analgesics to alleviate pain. We sought to evaluate the efficacy of common analgesics in tests of hot-plate nociception and postsurgical pain by using the Rat Grimace Scale. Rats received a single dose of one of several drug–dose combinations and were tested by using the hot-plate test (acute pain) or after laparotomy (with either prophylactic or intraoperative analgesic). The efficacy of analgesics for hot-plate pain was generally not predictive of efficacy for surgical pain. Carprofen and ketoprofen were rarely effective in any of the conditions tested. With the exception of the opioid buprenorphine, several of the drugs we tested required higher-than-recommended doses to alleviate pain. Taken together, our data suggest that current analgesic use frequently is insufficient, and many rats may experience significant postsurgical pain even when analgesics are used in commonly recommended doses. PMID:26224443

On the measurement of turbulent fluctuations in high-speed flows using hot wires and hot films

NASA Technical Reports Server (NTRS)

Acharya, M.

1978-01-01

A hot wire has a limited life in high speed wind-tunnel flows because it is typically subjected to large dynamic loads. As a consequence hot films and modified hot wires are frequently used for turbulence measurements in such flows. However, the fluctuation sensitivities of such probes are reduced because of various factors, leading to erroneous results. This paper describes the results of tests on some sensors in both subsonic and supersonic boundary-layer flows. A simple technique to determine dynamic calibration correction factors for the sensitivities is also presented.

Comparison of electron transport calculations in warm dense matter using the Ziman formula

DOE PAGES

Burrill, D. J.; Feinblum, D. V.; Charest, M. R. J.; ...

2016-02-10

The Ziman formulation of electrical conductivity is tested in warm and hot dense matter using the pseudo-atom molecular dynamics method. Several implementation options that have been widely used in the literature are systematically tested through a comparison to the accurate, but expensive Kohn–Sham density functional theory molecular dynamics (KS-DFT-MD) calculations. As a result, the comparison is made for several elements and mixtures and for a wide range of temperatures and densities, and reveals a preferred method that generally gives very good agreement with the KS-DFT-MD results, but at a fraction of the computational cost.

Hot cracking susceptibility of fillers 52 and 82 in alloy 690 welding

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

Wu, W.; Tsai, C.H.

1999-02-01

The hot cracking susceptibility of fillers 52 and 82 in a alloy 690 weldment is analyzed by the Varestraint test. Weld characteristics, microstructure, hardness distribution, and thermal analysis of the two filler metals are also examined. The weld metal of both fillers develops an extremely dense oxide layer. A stainless steel brush cannot remove the oxide layer, and a grinder may be needed between weld passes to assure a sound weld. Differential temperature analysis (DTA) shows that filler 82 has a lower melting point and a wider melting/solidification temperature differential ({Delta} T). These characteristics correlate with greater hot cracking susceptibilitymore » of filler 82 than 52 in Varestraint tests. The hot cracks are intergranular and are caused by elements segregating in grain boundaries.« less

General structure of fermion two-point function and its spectral representation in a hot magnetized medium

NASA Astrophysics Data System (ADS)

Das, Aritra; Bandyopadhyay, Aritra; Roy, Pradip K.; Mustafa, Munshi G.

2018-02-01

We have systematically constructed the general structure of the fermion self-energy and the effective quark propagator in the presence of a nontrivial background such as a hot magnetized medium. This is applicable to both QED and QCD. The hard thermal loop approximation has been used for the heat bath. We have also examined transformation properties of the effective fermion propagator under some of the discrete symmetries of the system. Using the effective fermion propagator we have analyzed the fermion dispersion spectra in a hot magnetized medium along with the spinor for each fermion mode obtained by solving the modified Dirac equation. The fermion spectra is found to reflect the discrete symmetries of the two-point functions. We note that for a chirally symmetric theory the degenerate left- and right-handed chiral modes in vacuum or in a heat bath get separated and become asymmetric in the presence of a magnetic field without disturbing the chiral invariance. The obtained general structure of the two-point functions is verified by computing the three-point function, which agrees with the existing results in one-loop order. Finally, we have computed explicitly the spectral representation of the two-point functions which would be very important to study the spectral properties of the hot magnetized medium corresponding to QED and QCD with background magnetic field.

Dynamic Response of X-37 Hot Structure Control Surfaces Exposed to Controlled Reverberant Acoustic Excitation

NASA Technical Reports Server (NTRS)

Grosveld, Ferdinand W.; Rizzi, Stephen A.; Rice, Chad E.

2004-01-01

This document represents a compilation of three informal reports from reverberant acoustic tests performed on X-37 hot structure control surfaces in the NASA Langley Research Center Structural Acoustics Loads and Transmission (SALT) facility. The first test was performed on a carbon-silicone carbide flaperon subcomponent on February 24, 2004. The second test was performed on a carbon-carbon ruddervator subcomponent on May 27, 2004. The third test was performed on a carbon-carbon flaperon subcomponent on June 30, 2004.

Hot spot detection, segmentation, and identification in PET images

NASA Astrophysics Data System (ADS)

Blaffert, Thomas; Meetz, Kirsten

2006-03-01

Positron Emission Tomography (PET) images provide functional or metabolic information from areas of high concentration of [18F]fluorodeoxyglucose (FDG) tracer, the "hot spots". These hot spots can be easily detected by the eye, but delineation and size determination required e.g. for diagnosis and staging of cancer is a tedious task that demands for automation. The approach for such an automated hot spot segmentation described in this paper comprises three steps: A region of interest detection by the watershed transform, a heart identification by an evaluation of scan lines, and the final segmentation of hot spot areas by a local threshold. The region of interest detection is the essential step, since it localizes the hot spot identification and the final segmentation. The heart identification is an example of how to differentiate between hot spots. Finally, we demonstrate the combination of PET and CT data. Our method is applicable to other techniques like SPECT.

Reactivating Catalytic Surface: Insights into the Role of Hot Holes in Plasmonic Catalysis.

PubMed

Peng, Tianhuan; Miao, Junjian; Gao, Zhaoshuai; Zhang, Linjuan; Gao, Yi; Fan, Chunhai; Li, Di

2018-03-01

Surface plasmon resonance of coinage metal nanoparticles is extensively exploited to promote catalytic reactions via harvesting solar energy. Previous efforts on elucidating the mechanisms of enhanced catalysis are devoted to hot electron-induced photothermal conversion and direct charge transfer to the adsorbed reactants. However, little attention is paid to roles of hot holes that are generated concomitantly with hot electrons. In this work, 13 nm spherical Au nanoparticles with small absorption cross-section are employed to catalyze a well-studied glucose oxidation reaction. Density functional theory calculation and X-ray absorption spectrum analysis reveal that hot holes energetically favor transferring catalytic intermediates to product molecules and then desorbing from the surface of plasmonic catalysts, resulting in the recovery of their catalytic activities. The studies shed new light on the use of the synergy of hot holes and hot electrons for plasmon-promoted catalysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development and efficiency assessment of process lubrication for hot forging

NASA Astrophysics Data System (ADS)

Kargin, S.; Artyukh, Viktor; Ignatovich, I.; Dikareva, Varvara

2017-10-01

The article considers innovative technologies in testing and production of process lubricants for hot bulk forging. There were developed new compositions of eco-friendly water-graphite process lubricants for hot extrusion and forging. New approaches to efficiency assessment of process lubricants are developed and described in the following article. Laboratory and field results are presented.

Difference in the action mechanism of radon inhalation and radon hot spring water drinking in suppression of hyperuricemia in mice

PubMed Central

Etani, Reo; Kataoka, Takahiro; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori

2016-01-01

Although radon therapy is indicated for hyperuricemia, the underlying mechanisms of action have not yet been elucidated in detail. Therefore, we herein examined the inhibitory effects of radon inhalation and hot spring water drinking on potassium oxonate (PO)–induced hyperuricemia in mice. Mice inhaled radon at a concentration of 2000 Bq/m3 for 24 h or were given hot spring water for 2 weeks. Mice were then administrated PO at a dose of 500 mg/kg. The results obtained showed that serum uric acid levels were significantly increased by the administration of PO. Radon inhalation or hot spring water drinking significantly inhibited elevations in serum uric acid levels through the suppression of xanthine oxidase activity in the liver. Radon inhalation activated anti-oxidative functions in the liver and kidney. These results suggest that radon inhalation inhibits PO-induced hyperuricemia by activating anti-oxidative functions, while hot spring water drinking may suppress PO-induced elevations in serum uric acid levels through the pharmacological effects of the chemical compositions dissolved in it. PMID:27021217

The Influence of Chlorella and Its Hot Water Extract Supplementation on Quality of Life in Patients with Breast Cancer

PubMed Central

Noguchi, Naoto; Maruyama, Isao; Yamada, Akira

2014-01-01

A self-control, randomized, and open-label clinical trial was performed to test the effects of the unicellular green algae Chlorella and hot water extract supplementation on quality of life (QOL) in patients with breast cancer. Forty-five female patients with breast cancer who were living at home and not hospitalized were randomly assigned to 3 groups receiving vitamin mix tablet (control), Chlorella granules (test food-1), or Chlorella extract drink (test food-2) daily for one month. The Functional Assessment of Cancer Therapy-Breast (FACT-B), the Izumo scale for abdominal symptom-specific QOL, and a narrative-form questionnaire were used to determine outcomes. Data of thirty-six subjects were included for final analysis. FACT-B scores at presupplementation found no significant group differences in all subscales. Scores on the breast cancer subscale in the Chlorella granule group significantly increased during the supplementation period (P = 0.042). Fifty percent of the Chlorella extract group reported positive effects by the test food such as reduction of fatigue and improvements of dry skin (P < 0.01 versus control group). The findings suggested the beneficial effects of Chlorella on breast cancer-related QOL and of Chlorella extract on vitality status in breast cancer patients. These findings need to be confirmed in a larger study. PMID:24799942

Thermal Analysis of the Fastrac Chamber/Nozzle

NASA Technical Reports Server (NTRS)

Davis, Darrell

2001-01-01

This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the Fastrac 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

Thermal Analysis of the MC-1 Chamber/Nozzle

NASA Technical Reports Server (NTRS)

Davis, Darrell W.; Phelps, Lisa H. (Technical Monitor)

2001-01-01

This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the MC-1 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

Predicting hot spots in protein interfaces based on protrusion index, pseudo hydrophobicity and electron-ion interaction pseudopotential features

PubMed Central

Xia, Junfeng; Yue, Zhenyu; Di, Yunqiang; Zhu, Xiaolei; Zheng, Chun-Hou

2016-01-01

The identification of hot spots, a small subset of protein interfaces that accounts for the majority of binding free energy, is becoming more important for the research of drug design and cancer development. Based on our previous methods (APIS and KFC2), here we proposed a novel hot spot prediction method. For each hot spot residue, we firstly constructed a wide variety of 108 sequence, structural, and neighborhood features to characterize potential hot spot residues, including conventional ones and new one (pseudo hydrophobicity) exploited in this study. We then selected 3 top-ranking features that contribute the most in the classification by a two-step feature selection process consisting of minimal-redundancy-maximal-relevance algorithm and an exhaustive search method. We used support vector machines to build our final prediction model. When testing our model on an independent test set, our method showed the highest F1-score of 0.70 and MCC of 0.46 comparing with the existing state-of-the-art hot spot prediction methods. Our results indicate that these features are more effective than the conventional features considered previously, and that the combination of our and traditional features may support the creation of a discriminative feature set for efficient prediction of hot spots in protein interfaces. PMID:26934646

Contact thermal shock test of ceramics

NASA Technical Reports Server (NTRS)

Rogers, W. P.; Emery, A. F.

1992-01-01

A novel quantitative thermal shock test of ceramics is described. The technique employs contact between a metal-cooling rod and hot disk-shaped specimen. In contrast with traditional techniques, the well-defined thermal boundary condition allows for accurate analyses of heat transfer, stress, and fracture. Uniform equibiaxial tensile stresses are induced in the center of the test specimen. Transient specimen temperature and acoustic emission are monitored continuously during the thermal stress cycle. The technique is demonstrated with soda-lime glass specimens. Experimental results are compared with theoretical predictions based on a finite-element method thermal stress analysis combined with a statistical model of fracture. Material strength parameters are determined using concentric ring flexure tests. Good agreement is found between experimental results and theoretical predictions of failure probability as a function of time and initial specimen temperature.

Hydration and Hot Yoga: Encouragement, Behaviors, and Outcomes.

PubMed

Mace Firebaugh, Casey J; Eggleston, Brandon

2017-01-01

Currently, the literature on hot yoga is lacking, and there is still much to understand regarding the safety of these practices. However, one point of safety often emphasized is hydration during the practice of hot yoga. The aim of this study was to examine hydration encouragement by hot yoga instructors and hydration behaviors and related outcomes by hot yoga participants. A cross-sectional study ( n = 700) collected self-report data on demographics, types and frequency of yoga practiced, hydration behaviors, and self-report measures of adverse outcomes experienced by participants during hot yoga. Associations between hydration encouragement, protective behaviors, and adverse outcomes were analyzed through Chi-square tests. Every protective hydration behavior was significantly associated with instructor encouragement ( P < 0.05). Hydration before or during hot yoga participation was associated with a lower occurrence of dehydration symptoms ( P < 0.05). Hot yoga instructors hold a key role in encouraging hydration and student safety outcomes.

Effects of gas temperature on nozzle damping experiments on cold-flow rocket motors

NASA Astrophysics Data System (ADS)

Sun, Bing-bing; Li, Shi-peng; Su, Wan-xing; Li, Jun-wei; Wang, Ning-fei

2016-09-01

In order to explore the impact of gas temperature on the nozzle damping characteristics of solid rocket motor, numerical simulations were carried out by an experimental motor in Naval Ordnance Test Station of China Lake in California. Using the pulse decay method, different cases were numerically studied via Fluent along with UDF (User Defined Functions). Firstly, mesh sensitivity analysis and monitor position-independent analysis were carried out for the computer code validation. Then, the numerical method was further validated by comparing the calculated results and experimental data. Finally, the effects of gas temperature on the nozzle damping characteristics were studied in this paper. The results indicated that the gas temperature had cooperative effects on the nozzle damping and there had great differences between cold flow and hot fire test. By discussion and analysis, it was found that the changing of mainstream velocity and the natural acoustic frequency resulted from gas temperature were the key factors that affected the nozzle damping, while the alteration of the mean pressure had little effect. Thus, the high pressure condition could be replaced by low pressure to reduce the difficulty of the test. Finally, the relation of the coefficients "alpha" between the cold flow and hot fire was got.

Conservation of hot regions in protein-protein interaction in evolution.

PubMed

Hu, Jing; Li, Jiarui; Chen, Nansheng; Zhang, Xiaolong

2016-11-01

The hot regions of protein-protein interactions refer to the active area which formed by those most important residues to protein combination process. With the research development on protein interactions, lots of predicted hot regions can be discovered efficiently by intelligent computing methods, while performing biology experiments to verify each every prediction is hardly to be done due to the time-cost and the complexity of the experiment. This study based on the research of hot spot residue conservations, the proposed method is used to verify authenticity of predicted hot regions that using machine learning algorithm combined with protein's biological features and sequence conservation, though multiple sequence alignment, module substitute matrix and sequence similarity to create conservation scoring algorithm, and then using threshold module to verify the conservation tendency of hot regions in evolution. This research work gives an effective method to verify predicted hot regions in protein-protein interactions, which also provides a useful way to deeply investigate the functional activities of protein hot regions. Copyright © 2016. Published by Elsevier Inc.

Investigation Leads to Improved Understanding of Space Shuttle RSRM Internal Insulation Joints

NASA Technical Reports Server (NTRS)

McWhorter, Bruce B.; Bolton, Doug E.; Hicken, Steve V.; Allred, Larry D.; Cook, Dave J.

2003-01-01

The Space Shuttle Reusable Solid Rocket Motor (RSRM) uses an internal insulation J-joint design for the mated insulation interface between two assembled RSRM segments. In this assembled (mated) segment configuration, this J-joint design serves as a thermal barrier to prevent hot gases from affecting the case field joint metal surfaces and O-rings. A pressure sensitive adhesive (PSA) provides some adhesion between the two mated insulation surfaces. In 1995, after extensive testing, a new ODC-free PSA (free of ozone depleting chemicals) was selected for flight on RSRM-55 (STS-78). Post-flight inspection revealed that the J-joint, equipped with the new ODC-free PSA, did not perform well. Hot gas seeped inside the J-joint interface. Although not a flight safety threat, the J-joint hot gas intrusion on RSRM-55 was a mystery to the investigators since the PSA had previously worked well on a full-scale static test. A team was assembled to study the J-joint and PSA further. All J-joint design parameters, measured data, and historical performance data were re-reviewed and evaluated by subscale testing and analysis. Although both the ODC-free and old PSA were weakened by humidity, the ODC-free PSA strength was lower to start with. Another RSRM full-scale static test was conducted in 1998 and intentionally duplicated the gas intrusion. This test, along with many concurring tests, showed that if a J-joint was 1) mated with the new ODC-free PSA, 2) exposed to a history of high humidity (Kennedy Space Center levels), and 3) also a joint which experienced significant but normal joint motion (J-joint deformation resulting from motor pressurization dynamics) then that J-joint would open (allow gas intrusion) during motor operation. When all of the data from the analyses, subscale tests, and full-scale tests were considered together, a theory emerged. Most of the joint motion on the RSRM occurs early in motor operation at which point the J-joints are pulled into tension. If the new PSA has been weakened due to humidity, then the J-joint will partially pull apart (inboard side), and the J-joint surfaces will be charred by exposure to hot gases. After early operation, a J-joint that has been pulled apart will come back together as the J-joint deformation decreases. This J-joint heating event is relatively short and occurs only during the first part of motor operation. Internal instrumentation was developed for another full-scale static test in February 2000. The static test instrumentation did indeed prove this theory to be correct. Post-test inspection revealed very similar charring characteristics as observed on RSRM-55. This experience of the development of a new PSA, its testing, the RSRM-55 flight, followed by the J-joint investigation led to good 'lessons learned' and to an additional fundamental understanding of the RSRM J-joint function.

Materials Processing Research and Development

DTIC Science & Technology

2010-08-01

3 2.2.1 Cavitation during Hot-Torsion Testing of Ti-6Al-4V .................................................... 3 2.2.2 The Effect of Strain...during Hot Torsion Testing of Ti-6Al-4V ........................................................................................ 4 2.2.4 Effect of...8 2.5.3 Systematic Approach to Microstructure Design of Ni-Base Alloys Using Classical Nucleation and Growth Relations Coupled with Phase

46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

Code of Federal Regulations, 2010 CFR

2010-10-01

... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted as...

Hot-Fire Test of Liquid Oxygen/Hydrogen Space Launch Mission Injector Applicable to Exploration Upper Stage

NASA Technical Reports Server (NTRS)

Barnett, Greg; Turpin, Jason; Nettles, Mindy

2015-01-01

This task is to hot-fire test an existing Space Launch Mission (SLM) injector that is applicable for all expander cycle engines being considered for the exploration upper stage. The work leverages investment made in FY 2013 that was used to additively manufacture three injectors (fig. 1) all by different vendors..

9 CFR 78.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... classification under this part. “B” branded. Branding with a hot iron the letter “B” high on the left hip near... semen plasma test, and the standard plate test. Dairy cattle. All cattle, regardless of age or sex or... and the Veterinarian in Charge; and (b)(1) Permanently identified by a “V” hot brand high on the hip...

46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

Code of Federal Regulations, 2013 CFR

2013-10-01

... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted as...

46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

Code of Federal Regulations, 2011 CFR

2011-10-01

... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted as...

46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

Code of Federal Regulations, 2014 CFR

2014-10-01

... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted as...

46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

Code of Federal Regulations, 2012 CFR

2012-10-01

... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted as...

Effect of Stress and Strain Path on Cavity Closure During Hot Working of an Alpha/Beta Titanium Alloy (Preprint)

DTIC Science & Technology

2007-07-01

damage totally. 15. SUBJECT TERMS Ti- 6Al - 4V , strain, stress, cavity closure, hot working, titanium alloy 16. SECURITY CLASSIFICATION OF: 17...stress state on deformation and cavitation during hot working of Ti- 6Al - 4V was established via torsion-compression and reversed-torsion tests...strain path and stress state on deformation and cavitation during hot working of Ti- 6Al - 4V was established via torsion-compression and reversed

A&M. Hot liquid waste treatment building (TAN616). Contextual view, facing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot liquid waste treatment building (TAN-616). Contextual view, facing south. Wall of hot shop (TAN-607) with high bay at left of view. Lower-roofed building at left edge of view is TAN- 633, hot cell annex. Complex at center of view is TAN-616. Tall metal building with gable roof is TAN-615. Photographer: Ron Paarmann. Date: September 22, 1997. INEEL negative no. HD-20-2-2 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Effects of surface chemistry on hot corrosion life: Overview

NASA Technical Reports Server (NTRS)

Merutka, J.

1982-01-01

This program concentrates on analyzing a limited number of hot corroded components from the field and the carrying out of a series of controlled laboratory experiments to establish the effects of oxide scale and coating chemistry on hot corrosion life. This is to be determined principally from the length of the incubation period, the investigation of the mechanisms of hot corrosion attack, and the fitting of the data generated from the test exposure experiments to an empirical life prediction model.

What Temperature of Coffee Exceeds the Pain Threshold? Pilot Study of a Sensory Analysis Method as Basis for Cancer Risk Assessment.

PubMed

Dirler, Julia; Winkler, Gertrud; Lachenmeier, Dirk W

2018-06-01

The International Agency for Research on Cancer (IARC) evaluates "very hot (>65 °C) beverages" as probably carcinogenic to humans. However, there is a lack of research regarding what temperatures consumers actually perceive as "very hot" or as "too hot". A method for sensory analysis of such threshold temperatures was developed. The participants were asked to mix a very hot coffee step by step into a cooler coffee. Because of that, the coffee to be tasted was incrementally increased in temperature during the test. The participants took a sip at every addition, until they perceive the beverage as too hot for consumption. The protocol was evaluated in the form of a pilot study using 87 participants. Interestingly, the average pain threshold of the test group (67 °C) and the preferred drinking temperature (63 °C) iterated around the IARC threshold for carcinogenicity. The developed methodology was found as fit for the purpose and may be applied in larger studies.

Hot and Spicy versus Cool and Minty as an Example of Organic Structure-Activity Relationships

NASA Astrophysics Data System (ADS)

Kimbrough, Doris R.

1997-07-01

There are two classes of substances that activate neural receptors that are involved in temperature perception. Structures of substances found in spices and food that we normally associate with "hot" (or spicy) and "cool" (or minty) flavors are presented and discussed. Functional group similarities within the two groups provide an interesting example of the relationship between molecular structure and molecular function in organic chemistry.

A comparative study on the effect of "black cohosh" and "evening primrose oil" on menopausal hot flashes.

PubMed

Mehrpooya, Maryam; Rabiee, Soghra; Larki-Harchegani, Amir; Fallahian, Amir-Mohammad; Moradi, Abbas; Ataei, Sara; Javad, Masoumeh Taravati

2018-01-01

Hot flashes are considered to be a common experience for menopausal women and they can compromise the quality of life. The objective of this study is to assess the efficacy of Cimicifuga racemosa in comparison with evening primrose oil (EPO) in postmenopausal women with menopause-related symptoms. This study was performed on 80 postmenopausal women with hot flashes. The participants were randomly divided into two groups by blocked randomization. The participants of one group received black cohosh and the other group received EPO for 8 weeks. The severity and number of hot flashes and quality of life were measured by four-point scale, and the Menopause-Specific Quality of Life (MENQOL) questionnaire at pre-intervention, 1 st , 4 th , and 8 th weeks after treatment. Data were analyzed in SPSS Version 16 using independent t -test, Chi-square, and Fisher's exact test. Average severity of hot flashes in both groups and number of hot flashes in black cohosh group in 8 th week were significantly lower than 1 st week ( P < 0.001), but number of hot flashes in primrose oil group in 8 th week showed no significant differences ( P = 0.32). The number of hot flashes and quality of life score in black cohosh arm compared to EPO showed a significant decrease in the 8 th week ( P < 0.05). All MENQOL scores were significantly improved in two groups ( P < 0.05), but the percentage of improvement in black cohosh arm was significantly superior to EPO group. Both herbs were effective in reduction of severity of hot flashes and improvement of the quality of life, but it seems that black cohosh is more effective than primrose oil because it was able to reduce the number of hot flashes too.

A virus-binding hot spot on human angiotensin-converting enzyme 2 is critical for binding of two different coronaviruses.

PubMed

Wu, Kailang; Chen, Lang; Peng, Guiqing; Zhou, Wenbo; Pennell, Christopher A; Mansky, Louis M; Geraghty, Robert J; Li, Fang

2011-06-01

How viruses evolve to select their receptor proteins for host cell entry is puzzling. We recently determined the crystal structures of NL63 coronavirus (NL63-CoV) and SARS coronavirus (SARS-CoV) receptor-binding domains (RBDs), each complexed with their common receptor, human angiotensin-converting enzyme 2 (hACE2), and proposed the existence of a virus-binding hot spot on hACE2. Here we investigated the function of this hypothetical hot spot using structure-guided biochemical and functional assays. The hot spot consists of a salt bridge surrounded by hydrophobic tunnel walls. Mutations that disturb the hot spot structure have significant effects on virus/receptor interactions, revealing critical energy contributions from the hot spot structure. The tunnel structure at the NL63-CoV/hACE2 interface is more compact than that at the SARS-CoV/hACE2 interface, and hence RBD/hACE2 binding affinities are decreased either by NL63-CoV mutations decreasing the tunnel space or by SARS-CoV mutations increasing the tunnel space. Furthermore, NL63-CoV RBD inhibits hACE2-dependent transduction by SARS-CoV spike protein, a successful application of the hot spot theory that has the potential to become a new antiviral strategy against SARS-CoV infections. These results suggest that the structural features of the hot spot on hACE2 were among the driving forces for the convergent evolution of NL63-CoV and SARS-CoV.

A pdf-Free Change Detection Test Based on Density Difference Estimation.

PubMed

Bu, Li; Alippi, Cesare; Zhao, Dongbin

2018-02-01

The ability to detect online changes in stationarity or time variance in a data stream is a hot research topic with striking implications. In this paper, we propose a novel probability density function-free change detection test, which is based on the least squares density-difference estimation method and operates online on multidimensional inputs. The test does not require any assumption about the underlying data distribution, and is able to operate immediately after having been configured by adopting a reservoir sampling mechanism. Thresholds requested to detect a change are automatically derived once a false positive rate is set by the application designer. Comprehensive experiments validate the effectiveness in detection of the proposed method both in terms of detection promptness and accuracy.

Capsicum and capsaicin--a review: case report of the use of hot peppers in child abuse.

PubMed

Tominack, R L; Spyker, D A

1987-01-01

Capsaicin, the active principle of hot peppers of the genus Capsicum, exhibits broad bioactivity. It targets neuronal structures which contain substance P, clinically seen as gastrointestinal and dermatologic irritation, bronchospasm and fibrinolysis. As a research tool, capsaicin profoundly alters neurologic anatomy and function. We review the toxicity of capsaicin and comment briefly on the use of hot peppers in child abuse.

Hot and Cool Forms of Inhibitory Control and Externalizing Behavior in Children of Mothers Who Smoked during Pregnancy: An Exploratory Study

ERIC Educational Resources Information Center

Huijbregts, Stephan C. J.; Warren, Alison J.; de Sonneville, Leo M. J.; Swaab-Barneveld, Hanna

2008-01-01

This study examined whether children exposed to prenatal smoking show deficits in "hot" and/or "cool" executive functioning (EF). Hot EF is involved in regulation of affect and motivation, whereas cool EF is involved in handling abstract, decontextualized problems. Forty 7 to 9-year-old children (15 exposed to prenatal smoking, 25 non-exposed)…

Modeling RF Fields in Hot Plasmas with Parallel Full Wave Code

NASA Astrophysics Data System (ADS)

Spencer, Andrew; Svidzinski, Vladimir; Zhao, Liangji; Galkin, Sergei; Kim, Jin-Soo

2016-10-01

FAR-TECH, Inc. is developing a suite of full wave RF plasma codes. It is based on a meshless formulation in configuration space with adapted cloud of computational points (CCP) capability and using the hot plasma conductivity kernel to model the nonlocal plasma dielectric response. The conductivity kernel is calculated by numerically integrating the linearized Vlasov equation along unperturbed particle trajectories. Work has been done on the following calculations: 1) the conductivity kernel in hot plasmas, 2) a monitor function based on analytic solutions of the cold-plasma dispersion relation, 3) an adaptive CCP based on the monitor function, 4) stencils to approximate the wave equations on the CCP, 5) the solution to the full wave equations in the cold-plasma model in tokamak geometry for ECRH and ICRH range of frequencies, and 6) the solution to the wave equations using the calculated hot plasma conductivity kernel. We will present results on using a meshless formulation on adaptive CCP to solve the wave equations and on implementing the non-local hot plasma dielectric response to the wave equations. The presentation will include numerical results of wave propagation and absorption in the cold and hot tokamak plasma RF models, using DIII-D geometry and plasma parameters. Work is supported by the U.S. DOE SBIR program.

A feature-based approach to modeling protein–protein interaction hot spots

PubMed Central

Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

2009-01-01

Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to π–related interactions, especially π · · · π interactions. PMID:19273533

Change in resonance parameters of a linear molecule as it bends: Evidence in electron-impact vibrational transitions of hot COS and CO2 molecules*

NASA Astrophysics Data System (ADS)

Hoshino, Masamitsu; Ishijima, Yohei; Kato, Hidetoshi; Mogi, Daisuke; Takahashi, Yoshinao; Fukae, Katsuya; Limão-Vieira, Paulo; Tanaka, Hiroshi; Shimamura, Isao

2016-04-01

Inelastic and superelastic electron-impact vibrational excitation functions of hot carbonyl sulphide COS (and hot CO2) are measured for electron energies from 0.5 to 3.0 eV (1.5 to 6.0 eV) and at a scattering angle of 90°. Based on the vibrational populations and the principle of detailed balance, these excitation functions are decomposed into contributions from state-to-state vibrational transitions involving up to the second bending overtone (030) in the electronically ground state. Both the 2Π resonance for COS around 1.2 eV and the 2Πu resonance for CO2 around 3.8 eV are shifted to lower energies as the initial vibrational state is excited in the bending mode. The width of the resonance hump for COS changes only little as the molecule bends, whereas that of the overall boomerang resonance for CO2 becomes narrower. The angular distribution of the electrons resonantly scattered by hot COS and hot CO2 is also measured. The different shapes depending on the vibrational transitions and gas temperatures are discussed in terms of the symmetry of the vibrational wave functions. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

Hotspots in Hindsight

NASA Astrophysics Data System (ADS)

Julian, B. R.; Foulger, G. R.; Hatfield, O.; Jackson, S.; Simpson, E.; Einbeck, J.; Moore, A.

2014-12-01

Torsvik et al. [2006] suggest that the original locations of large igneous provinces ("LIPs") and kimberlites, and current locations of melting anomalies (hot-spots) lie preferentially above the margins of two Large Lower-Mantle Shear Velocity Provinces" (LLSVPs), at the base of the mantle, and that the correlation has a high significance level (> 99.9999%). They conclude the LLSVP margins are Plume-Generation Zones, and deep-mantle plumes cause hotspots and LIPs. This conclusion raises questions about what physical processes could be responsible, because, for example the LLSVPs are likely dense and not abnormally hot [Trampert et al., 2004]. The supposed LIP-hotspot-LLSVP correlations probably are examples of the "Hindsight Heresy" [Acton, 1959], of basing a statistical test upon the same data sample that led to the initial formulation of a hypothesis. In doing this, many competing hypotheses will have been considered and rejected, but this fact will not be taken into account in statistical assessments. Furthermore, probabilities will be computed for many subsets and combinations of the data, and the best-correlated cases will be cited, but this fact will not be taken into account either. Tests using independent hot-spot catalogs and mantle models suggest that the actual significance levels of the correlations are two or three orders of magnitude smaller than claimed. These tests also show that hot spots correlate well with presumably shallowly rooted features such as spreading plate boundaries. Consideration of the kimberlite dataset in the context of geological setting suggests that their apparent association with the LLSVP margins results from the fact that the Kaapvaal craton, the site of most of the kimberlites considered, lies in Southern Africa. These observations raise questions about the distinction between correlation and causation and underline the necessity to take geological factors into account. Fig: Left: Cumulative distributions of distances from hotspots to nearest ridge for 5 hotspot lists; heavy red curve: Distribution function for a random point on Earth's surface. Hotspots are closer to ridges than expected at random. Right: For each list, the probability of at least as many random points being as close to a ridge. Values to right have higher significance.

Silanated Surface Treatment: Effects on the Bond Strength to Lithium Disilicate Glass-Ceramic.

PubMed

Baratto, Samantha Schaffer Pugsley; Spina, Denis Roberto Falcão; Gonzaga, Carla Castiglia; Cunha, Leonardo Fernandes da; Furuse, Adilson Yoshio; Baratto Filho, Flares; Correr, Gisele Maria

2015-10-01

The aim of this study was to evaluate the effect of silanization protocols on the bond strength of two resin cements to a lithium disilicate glass-ceramic. Thirty-two ceramic discs were assigned to 2 groups (n=16): G1 - dual-cured resin cement and G2 - light-cured resin cement. Four subgroups were evaluated according to the used silanization protocol. The glass-ceramic was etched with 10% hydrofluoric acid for 20 s and silane was applied for 1 min, as follows: CTL - according to the manufacturer's instructions; HA - dried with hot air; NWA - washed and dried with water and air at room temperature; HWA - washed and dried with hot water and hot air. Thereafter, adhesive was applied and light-cured for 20 s. Silicon molds were used to prepare resin cement cylinders (1x1 mm) on the ceramic surface. The specimens were stored in deionized water at 37 °C for 48 h and subjected to a micro-shear test. The data were submitted to statistical analysis (?#61537;=0.05). Group G1 showed higher bond strengths than G2, except for the CTL and NWA subgroups. Differences as function of the silanization protocol were only observed in G1: HWA (25.13±6.83)≥HA (22.95±7.78)≥CTL(17.44±7.24) ≥NWA(14.63±8.76). For G2 there was no difference among the subgroups. In conclusion, the silanization protocol affected the resin cement/ceramic bond strengths, depending on the material. Washing/drying with hot water and/or hot air increased only the bond strength of the dual-cured resin cement.

Apparatus for Hot Impact Testing of Material Specimens

NASA Technical Reports Server (NTRS)

Pawlik, Ralph J.; Choi, Sung R.

2006-01-01

An apparatus for positioning and holding material specimens is a major subsystem of a system for impact testing of the specimens at temperatures up to 1,500 C. This apparatus and the rest of the system are designed especially for hot impact testing of advanced ceramics, composites, and coating materials. The apparatus includes a retaining fixture on a rotating stage on a vertically movable cross support driven by a linear actuator. These components are located below a furnace wherein the hot impact tests are performed (see Figure 1). In preparation for a test, a specimen is mounted on the retaining fixture, then the cross support is moved upward to raise the specimen, through an opening in the bottom of the furnace, to the test position inside the furnace. On one side of the furnace there is another, relatively small opening on a direct line to the specimen. Once the specimen has become heated to the test temperature, the test is performed by using an instrumented external pressurized-gas-driven gun to shoot a projectile through the side opening at the specimen.

High Velocity Oxidation and Hot Corrosion Resistance of Some ODS Alloys

NASA Technical Reports Server (NTRS)

Lowell, C. E.; Deadmore, D. L.

1977-01-01

Several oxide dispersion strengthened (ODS) alloys were tested for cyclic, high velocity, oxidation, and hot corrosion resistance. These results were compared to the resistance of an advanced, NiCrAl coated superalloy. An ODS FeCrAl were identified as having sufficient oxidation and hot corrosion resistance to allow potential use in an aircraft gas turbine without coating.

A&M. Hot liquid waste treatment building (TAN616). Camera facing southwest. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot liquid waste treatment building (TAN-616). Camera facing southwest. Oblique view of east and north walls. Note three corrugated pipes at lower left indicating location of underground hot waste storage tanks. Photographer: Ron Paarmann. Date: September 22, 1997. INEEL negative no. HD-20-1-4 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Hot forging of roll-cast high aluminum content magnesium alloys

NASA Astrophysics Data System (ADS)

Kishi, Tomohiro; Watari, Hisaki; Suzuki, Mayumi; Haga, Toshio

2017-10-01

This paper reports on hot forging of high aluminum content magnesium alloy sheets manufactured using horizontal twin-roll casting. AZ111 and AZ131 were applied for twin-roll casting, and a hot-forging test was performed to manufacture high-strength magnesium alloy components economically. For twin-roll casting, the casting conditions of a thick sheet for hot forging were investigated. It was found that twin-roll casting of a 10mm-thick magnesium alloy sheet was possible at a roll speed of 2.5m/min. The grain size of the cast strip was 50 to 70µm. In the hot-forging test, blank material was obtained from as-cast strip. A servo press machine with a servo die cushion was used to investigate appropriate forging conditions (e.g., temperature, forging load, and back pressure) for twin-roll casts (TRCs) AZ111 and AZ131. It was determined that high aluminum content magnesium alloy sheets manufactured using twin-roll casting could be forged with a forging load of 150t and a back pressure of 3t at 420 to 430°C. Applying back pressure during hot forging effectively forged a pin-shaped product.

Metagenomic Analysis of Hot Springs in Central India Reveals Hydrocarbon Degrading Thermophiles and Pathways Essential for Survival in Extreme Environments.

PubMed

Saxena, Rituja; Dhakan, Darshan B; Mittal, Parul; Waiker, Prashant; Chowdhury, Anirban; Ghatak, Arundhuti; Sharma, Vineet K

2016-01-01

Extreme ecosystems such as hot springs are of great interest as a source of novel extremophilic species, enzymes, metabolic functions for survival and biotechnological products. India harbors hundreds of hot springs, the majority of which are not yet explored and require comprehensive studies to unravel their unknown and untapped phylogenetic and functional diversity. The aim of this study was to perform a large-scale metagenomic analysis of three major hot springs located in central India namely, Badi Anhoni, Chhoti Anhoni, and Tattapani at two geographically distinct regions (Anhoni and Tattapani), to uncover the resident microbial community and their metabolic traits. Samples were collected from seven distinct sites of the three hot spring locations with temperature ranging from 43.5 to 98°C. The 16S rRNA gene amplicon sequencing of V3 hypervariable region and shotgun metagenome sequencing uncovered a unique taxonomic and metabolic diversity of the resident thermophilic microbial community in these hot springs. Genes associated with hydrocarbon degradation pathways, such as benzoate, xylene, toluene, and benzene were observed to be abundant in the Anhoni hot springs (43.5-55°C), dominated by Pseudomonas stutzeri and Acidovorax sp., suggesting the presence of chemoorganotrophic thermophilic community with the ability to utilize complex hydrocarbons as a source of energy. A high abundance of genes belonging to methane metabolism pathway was observed at Chhoti Anhoni hot spring, where methane is reported to constitute >80% of all the emitted gases, which was marked by the high abundance of Methylococcus capsulatus . The Tattapani hot spring, with a high-temperature range (61.5-98°C), displayed a lower microbial diversity and was primarily dominated by a nitrate-reducing archaeal species Pyrobaculum aerophilum . A higher abundance of cell metabolism pathways essential for the microbial survival in extreme conditions was observed at Tattapani. Taken together, the results of this study reveal a novel consortium of microbes, genes, and pathways associated with the hot spring environment.

Solar power satellite 50 kW VKS-7773 cw klystron evaluation

NASA Technical Reports Server (NTRS)

Larue, A. D.

1977-01-01

A test program for evaluating the electrical characteristics of a cw, 50 kW power output klystron at 2.45 GHz is described. The tube tested was an 8-cavity klystron, the VKS-7773 which had been in storage for seven years. Tests included preliminary testing of the tube, cold tests of microwave components, tests of the electromagnet, and first and second hot tests of the tube. During the second hot test, the tuner in the fifth cavity went down to air, preventing any further testing. Cause of failure is not known, and recommendations are to repair and modify the tube, then proceed with testing as before to meet program objectives.

Empirical correlations of the performance of vapor-anode PX-series AMTEC cells

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

Huang, L.; Merrill, J.M.; Mayberry, C.

Power systems based on AMTEC technology will be used for future NASA missions, including a Pluto-Express (PX) or Europa mission planned for approximately year 2004. AMTEC technology may also be used as an alternative to photovoltaic based power systems for future Air Force missions. An extensive development program of Alkali-Metal Thermal-to-Electric Conversion (AMTEC) technology has been underway at the Vehicle Technologies Branch of the Air Force Research Laboratory (AFRL) in Albuquerque, New Mexico since 1992. Under this program, numerical modeling and experimental investigations of the performance of the various multi-BASE tube, vapor-anode AMTEC cells have been and are being performed.more » Vacuum testing of AMTEC cells at AFRL determines the effects of changing the hot and cold end temperatures, T{sub hot} and T{sub cold}, and applied external load, R{sub ext}, on the cell electric power output, current-voltage characteristics, and conversion efficiency. Test results have traditionally been used to provide feedback to cell designers, and to validate numerical models. The current work utilizes the test data to develop empirical correlations for cell output performance under various working conditions. Because the empirical correlations are developed directly from the experimental data, uncertainties arising from material properties that must be used in numerical modeling can be avoided. Empirical correlations of recent vapor-anode PX-series AMTEC cells have been developed. Based on AMTEC theory and the experimental data, the cell output power (as well as voltage and current) was correlated as a function of three parameters (T{sub hot}, T{sub cold}, and R{sub ext}) for a given cell. Correlations were developed for different cells (PX-3C, PX-3A, PX-G3, and PX-5A), and were in good agreement with experimental data for these cells. Use of these correlations can greatly reduce the testing required to determine electrical performance of a given type of AMTEC cell over a wide range of operating conditions.« less

Calibrating/testing meters in hot water test bench VM7

NASA Astrophysics Data System (ADS)

Kling, E.; Stolt, K.; Lau, P.; Mattiasson, K.

A Hot Water Test Bench, VM7, has been developed and constructed for the calibration and testing of volume and flowmeters, in a project at the National Volume Measurement Laboratory at the Swedish National Testing and Research Institute. The intended area of use includes use as a reference at audit measurements, e.g. for accredited laboratories, calibration of meters for the industry and for the testing of hot water meters. The objective of the project, which was initiated in 1989, was to design equipment with stable flow and with a minimal temperature drop even at very low flow rates. The principle of the design is a closed system with two pressure tanks at different pressures. The water is led from the high pressure tank through the test object and the volume standard, in the form of master meters or a piston prover alternatively, to the low pressure tank. Calibrations/tests are made comparing the indication of the test object to that of master meters covering the current flow rate. These are, in the same test cycle, calibrated to the piston prover. Alternatively, the test object can be calibrated directly to the piston prover.

Test methods and response surface models for hot, humid air decontamination of materials contaminated with dirty spores of Bacillus anthracis ∆Sterne and Bacillus thuringiensis Al Hakam.

PubMed

Buhr, T L; Young, A A; Barnette, H K; Minter, Z A; Kennihan, N L; Johnson, C A; Bohmke, M D; DePaola, M; Cora-Laó, M; Page, M A

2015-11-01

To develop test methods and evaluate survival of Bacillus anthracis ∆Sterne or Bacillus thuringiensis Al Hakam on materials contaminated with dirty spore preparations after exposure to hot, humid air using response surface modelling. Spores (>7 log10 ) were mixed with humic acid + spent sporulation medium (organic debris) or kaolin (dirt debris). Spore samples were then dried on five different test materials (wiring insulation, aircraft performance coating, anti-skid, polypropylene, and nylon). Inoculated materials were tested with 19 test combinations of temperature (55, 65, 75°C), relative humidity (70, 80, 90%) and time (1, 2, 3 days). The slowest spore inactivation kinetics was on nylon webbing and/or after addition of organic debris. Hot, humid air effectively decontaminates materials contaminated with dirty Bacillus spore preparations; debris and material interactions create complex decontamination kinetic patterns; and B. thuringiensis Al Hakam is a realistic surrogate for B. anthracis. Response surface models of hot, humid air decontamination were developed which may be used to select decontamination parameters for contamination scenarios including aircraft. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

A calibration loop to test hot-wire response under supercritical conditions

NASA Astrophysics Data System (ADS)

Radulović, Ivana; Vukoslavčević, P. V.; Wallace, J. M.

2004-11-01

A calibration facility to test the response of hot-wires in CO2 flow under supercritical conditions has been designed and constructed. It is capable of inducing variable speeds at different temperatures and pressures in the ranges of 0.15 - 2 m/s, 15 - 70 deg. C and 1 - 100 bar. The facility is designed as a closed loop with a test section, pump, electrical heater, DC motor and different regulating and measuring devices. The test section is a small tunnel, with a diffuser, honeycomb, screens and a nozzle to provide a uniform flow with a low turbulence level. The speed variation is created by a sealed, magnetic driven gear pump, with a variable rpm DC motor. Using the electrical heater and regulating the amount of CO2 in the facility, the desired temperature and pressure can be reached. The dimensions of the instalation are minimized to reduce the heat, pump power required, and CO2 consumption and to optimize safety. Preliminary testing of a single hot-wire velocity sensor at constant pressure (80 bar) and variable speed and temperature will be briefly described. The hot-wire probes calibrated in this loop will be used to measure turbulence properties in supercritical CO2 in support of improved designs of nuclear reactors to be cooled by supercritical fluids.

Detection of surface carbon and hydrocarbons in hot spot regions of niobium superconducting rf cavities by Raman spectroscopy

DOE PAGES

Cao, C.; Argonne National Lab.; Ford, D.; ...

2013-06-26

Raman microscopy/spectroscopy measurements are presented on high purity niobium (Nb) samples, including pieces from hot spot regions of a tested superconducting rf cavity that exhibit a high density of etch pits. Measured spectra are compared with density functional theory calculations of Raman-active, vibrational modes of possible surface Nb-O and Nb-H complexes. The Raman spectra inside particularly rough pits in all Nb samples show clear differences from surrounding areas, exhibiting enhanced intensity and sharp peaks. While some of the sharp peaks are consistent with calculated NbH and NbH 2 modes, there is better overall agreement with C-H modes in chain-type hydrocarbons.more » Other spectra reveal two broader peaks attributed to amorphous carbon. Niobium foils annealed to >2000°C in high vacuum develop identical Raman peaks when subjected to cold working. Regions with enhanced C and O have also been found by SEM/EDX spectroscopy in the hot spot samples and cold-worked foils, corroborating the Raman results. Such regions with high concentrations of impurities are expected to suppress the local superconductivity and this may explain the correlation between hot spots in superconducting rf (SRF) cavities and the observation of a high density of surface pits. Finally, the origin of localized high carbon and hydrocarbon regions is unclear at present but it is suggested that particular processing steps in SRF cavity fabrication may be responsible.« less

Detection of surface carbon and hydrocarbons in hot spot regions of niobium superconducting rf cavities by Raman spectroscopy

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

Cao, C.; Argonne National Lab.; Ford, D.

Raman microscopy/spectroscopy measurements are presented on high purity niobium (Nb) samples, including pieces from hot spot regions of a tested superconducting rf cavity that exhibit a high density of etch pits. Measured spectra are compared with density functional theory calculations of Raman-active, vibrational modes of possible surface Nb-O and Nb-H complexes. The Raman spectra inside particularly rough pits in all Nb samples show clear differences from surrounding areas, exhibiting enhanced intensity and sharp peaks. While some of the sharp peaks are consistent with calculated NbH and NbH 2 modes, there is better overall agreement with C-H modes in chain-type hydrocarbons.more » Other spectra reveal two broader peaks attributed to amorphous carbon. Niobium foils annealed to >2000°C in high vacuum develop identical Raman peaks when subjected to cold working. Regions with enhanced C and O have also been found by SEM/EDX spectroscopy in the hot spot samples and cold-worked foils, corroborating the Raman results. Such regions with high concentrations of impurities are expected to suppress the local superconductivity and this may explain the correlation between hot spots in superconducting rf (SRF) cavities and the observation of a high density of surface pits. Finally, the origin of localized high carbon and hydrocarbon regions is unclear at present but it is suggested that particular processing steps in SRF cavity fabrication may be responsible.« less

Hot Ductility of the 17-4 PH Stainless Steels

NASA Astrophysics Data System (ADS)

Herrera Lara, V.; Guerra Fuentes, L.; Covarrubias Alvarado, O.; Salinas Rodriguez, A.; Garcia Sanchez, E.

2016-03-01

The mechanisms of loss of hot ductility and the mechanical behavior of 17-4 PH alloys were investigated using hot tensile testing at temperatures between 700 and 1100 °C and strain rates of 10-4, 10-2, and 10-1 s-1. Scanning electron microscopy was used in conjunction with the results of the tensile tests to find the temperature region of loss of ductility and correlate it with cracking observed during processing by hot upsetting prior to ring rolling. It is reported that 17-4 PH alloys lose ductility in a temperature range around 900 °C near to the duplex austenite + ferrite phase field. Furthermore, it is found that niobium carbides precipitated at austenite/ferrite interfaces and grain boundaries have a pronounced effect on the mechanical behavior of the alloy during high-temperature deformation.

Highly Extensible Programmed Biosensing Circuits with Fast Memory

DTIC Science & Technology

2011-12-16

single-cell imaging in microfluidic environment. Yeast strain YTS2ab_1 has constitutive Hog1-eGFP production and thus upon a step function of sorbitol ...expect a sorbitol pulse to cause Hog1-NeGFP to localize to the nucleus, and the resulting Hog1-Hot1 interaction to drive nuclear fluorescence...YTS2ab_3 – W303-A background, hot1D::loxP, hog1D::loxP, HO::Hog1:Hog1-NeGFP_Hot1:Hot1-CeGFP Time = 5 min prior to Sorbitol Pulse (A) Brightfield, 63X Oil

Single Particle Damage Events in Candidate Star Camera Sensors

NASA Technical Reports Server (NTRS)

Marshall, Paul; Marshall, Cheryl; Polidan, Elizabeth; Wacyznski, Augustyn; Johnson, Scott

2005-01-01

Si charge coupled devices (CCDs) are currently the preeminent detector in star cameras as well as in the near ultraviolet (uv) to visible wavelength region for astronomical observations in space and in earth-observing space missions. Unfortunately, the performance of CCDs is permanently degraded by total ionizing dose (TID) and displacement damage effects. TID produces threshold voltage shifts on the CCD gates and displacement damage reduces the charge transfer efficiency (CTE), increases the dark current, produces dark current nonuniformities and creates random telegraph noise in individual pixels. In addition to these long term effects, cosmic ray and trapped proton transients also interfere with device operation on orbit. In the present paper, we investigate the dark current behavior of CCDs - in particular the formation and annealing of hot pixels. Such pixels degrade the ability of a CCD to perform science and also can present problems to the performance of star camera functions (especially if their numbers are not correctly anticipated). To date, most dark current radiation studies have been performed by irradiating the CCDs at room temperature but this can result in a significantly optimistic picture of the hot pixel count. We know from the Hubble Space Telescope (HST) that high dark current pixels (so-called hot pixels or hot spikes) accumulate as a function of time on orbit. For example, the HST Advanced Camera for Surveys/Wide Field Camera instrument performs monthly anneals despite the loss of observational time, in order to partially anneal the hot pixels. Note that the fact that significant reduction in hot pixel populations occurs for room temperature anneals is not presently understood since none of the commonly expected defects in Si (e.g. divacancy, E center, and A-center) anneal at such a low temperature. A HST Wide Field Camera 3 (WFC3) CCD manufactured by E2V was irradiated while operating at -83C and the dark current studied as a function of temperature while the CCD was warmed to a sequence of temperatures up to a maximum of +30C. The device was then cooled back down to -83 and re-measured. Hot pixel populations were tracked during the warm-up and cool-down. Hot pixel annealing began below 40C and the anneal process was largely completed before the detector reached +3OC. There was no apparent sharp temperature dependence in the annealing. Although a large fraction of the hot pixels fell below the threshold to be counted as a hot pixel, they nevertheless remained warmer than the remaining population. The details of the mechanism for the formation and annealing of hot pixels is not presently understood, but it appears likely that hot pixels are associated with displacement damage occurring in high electric field regions.

Associations between and development of cool and hot executive functions across early childhood.

PubMed

O'Toole, Sarah; Monks, Claire P; Tsermentseli, Stella

2018-03-01

This study explored the development of cool and hot EF skills across early childhood. Children 4.5- to 5.5-years-old (N = 80) completed performance-based assessments of cool EF (inhibition and working memory), hot EF (affective decision-making and delay of gratification) at three time points across 12 months. Cool EF task performance was consistently correlated with early childhood, but hot EF task performance was not. Performance on cool EF tasks showed significant improvements over early childhood, but performance on hot EF tasks did not. During early childhood performance on delay of gratification and affective decision-making tasks may therefore be unrelated and show limited sensitivity to improvement. Statement of contribution What is already known about cool and hot EF An EF model has been proposed that distinguishes between cool-cognitive and hot-affective skills. Findings regarding whether cool and hot EF are distinct in early childhood are mixed. Hot EF skills, compared to cool EF abilities, are thought to develop more gradually. What the present study adds to understanding of cool and hot EF Performance on cool EF tasks and hot delay of gratification were associated in early childhood. Performance on hot EF tasks was not related, meaning they do not tap the same underlying factor. Age related gains in hot EF were not found, but 5-year-olds had better hot EF than 4-year-olds. © 2017 The British Psychological Society.

HOT CELL BUILDING, TRA632. FIRST FLOOR FOUNDATION PLAN SHOWS SECTIONALIZED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. FIRST FLOOR FOUNDATION PLAN SHOWS SECTIONALIZED FLOOR LOADINGS AND CONCRETE SLAB THICKNESSES, A TYPICAL FEATURE OF NUCLEAR ARCHITECTURE. IDAHO OPERATIONS OFFICE MTR-632-IDO-2, 11/1952. INL INDEX NO. 531-0632-62-396-110561, REV. 1. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

75 FR 4618 - Office of Hazardous Materials Safety; Notice of Applications for Special Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-28

... desired, include a self-addressed stamped postcard showing the special permit number. FOR FURTHER... lieu of the hot water bath test. (modes 1, 2, 3, 4, 5). 14954-N Zotos International, 49 CFR 173.306(a... lieu of the hot water bath test. (mode 1). 14956-N American Type Culture 49 CFR 173.196, 178.609 To...

Single element injector testing for STME injector technology

NASA Technical Reports Server (NTRS)

Hulka, J.; Schneider, J. A.; Davis, J.

1992-01-01

An oxidizer-swirled coaxial element injector is being developed for application in the liquid oxygen/gaseous hydrogen Space Transportation Main Engine (STME) for the National Launch System (NLS) vehicle. This paper reports on the first two parts of a four part single injector element study for optimization of the STME injector design. Measurements of Rupe mixing efficiency and atomization characteristics are reported for single element versions of injection elements from two multielement injectors that have been recently hot fire tested. Rather than attempting to measure a definitive mixing efficiency or droplet size parameters of these injector elements, the purpose of these experiments was to provide a baseline comparison for evaluating future injector element design modifications. Hence, all the experiments reported here were conducted with cold flow simulants to nonflowing, ambient conditions. Mixing experiments were conducted with liquid/liquid simulants to provide economical trend data. Atomization experiments were conducted with liquid/gas simulants without backpressure. The results, despite significant differences from hot fire conditions, were found to relate to mixing and atomization parameters deduced from the hot fire testing, suggesting that these experiments are valid for trend analyses. Single element and subscale multielement hot fire testing will verify optimized designs before committing to fullscale fabrication.

Development of a test device to characterize thermal protective performance of fabrics against hot steam and thermal radiation

NASA Astrophysics Data System (ADS)

Su, Yun; Li, Jun

2016-12-01

Steam burns severely threaten the life of firefighters in the course of their fire-ground activities. The aim of this paper was to characterize thermal protective performance of flame-retardant fabrics exposed to hot steam and low-level thermal radiation. An improved testing apparatus based on ASTM F2731-11 was developed in order to simulate the routine fire-ground conditions by controlling steam pressure, flow rate and temperature of steam box. The thermal protective performance of single-layer and multi-layer fabric system with/without an air gap was studied based on the calibrated tester. It was indicated that the new testing apparatus effectively evaluated thermal properties of fabric in hot steam and thermal radiation. Hot steam significantly exacerbated the skin burn injuries while the condensed water on the skin’s surface contributed to cool down the skin tissues during the cooling. Also, the absorbed thermal energy during the exposure and the cooling was mainly determined by the fabric’s configuration, the air gap size, the exposure time and the existence of hot steam. The research provides a effective method to characterize the thermal protection of fabric in complex conditions, which will help in optimization of thermal protection performance of clothing and reduction of steam burn.

Using iron line reverberation and spectroscopy to distinguish Kerr and non-Kerr black holes

NASA Astrophysics Data System (ADS)

Jiang, Jiachen; Bambi, Cosimo; Steiner, James F.

2015-05-01

The iron Kα line commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole candidates is produced by the illumination of a cold accretion disk by a hot corona. In this framework, the activation of a new flaring region in the hot corona imprints a time variation on the iron line spectrum. Future X-ray facilities with high time resolution and large effective areas may be able to measure the so-called 2-dimensional transfer function; that is, the iron line profile detected by a distant observer as a function of time in response to an instantaneous flare from the X-ray primary source. This work is a preliminary study to determine if and how such a technique can provide more information about the spacetime geometry around the compact object than the already possible measurements of the time-integrated iron line profile. Within our simplified model, we find that a measurement of iron line reverberation can improve constraints appreciably given a sufficiently strong signal, though that most of the information is present in the time-integrated spectrum. Our aim is to test the Kerr metric. We find that current X-ray facilities and data are unable to provide strong tests of the Kerr nature of supermassive black hole candidates. We consider an optimistic case of 105 iron line photons from a next-generation data set. With such data, the reverberation model improves upon the spectral constraint by an order of magnitude.

Thermal degradation of wood fibers during hot-pressing of MDF composites. Part I, Relative effects and benefits of thermal exposure

Treesearch

Jerrold E. Winandy; Andrzej M. Krzysik

2007-01-01

This research evaluated the potential of wood fiber to chemically decompose during hot-pressing. We evaluated changes in carbohydrate composition and structure as a function of multiple press temperatures (180°, 200°, and 220°C) and an array of hot-pressing durations from 180 to 2500 s. Results show how this thermal degradation in chemical composition directly results...

Cold Helium Pressurization for Liquid Oxygen/Liquid Methane Propulsion Systems: Fully-Integrated Hot-Fire Test Results

NASA Technical Reports Server (NTRS)

Morehead, R. L.; Atwell, M. J.; Melcher, J. C.; Hurlbert, E. A.

2016-01-01

Hot-fire test demonstrations were successfully conducted using a cold helium pressurization system fully integrated into a liquid oxygen (LOX) / liquid methane (LCH4) propulsion system (Figure 1). Cold helium pressurant storage at near liquid nitrogen (LN2) temperatures (-275 F and colder) and used as a heated tank pressurant provides a substantial density advantage compared to ambient temperature storage. The increased storage density reduces helium pressurant tank size and mass, creating payload increases of 35% for small lunar-lander sized applications. This degree of mass reduction also enables pressure-fed propulsion systems for human-rated Mars ascent vehicle designs. Hot-fire test results from the highly-instrumented test bed will be used to demonstrate system performance and validate integrated models of the helium and propulsion systems. A pressurization performance metric will also be developed as a means to compare different active pressurization schemes.

Advances in Hot-Structure Development

NASA Technical Reports Server (NTRS)

Rivers, H. Kevin; Glass, David E.

2006-01-01

The National Aeronautics and Space Administration has actively participated in the development of hot structures technology for application to hypersonic flight systems. Hot structures have been developed for vehicles including the X-43A, X-37, and the Space Shuttle. These trans-atmospheric and atmospheric entry flight systems that incorporate hot-structures technology are lighter weight and require less maintenance than those that incorporate parasitic, thermal-protection materials that attach to warm or cool substructure. The development of hot structures requires a thorough understanding of material performance in an extreme environment, boundary conditions and load interactions, structural joint performance, and thermal and mechanical performance of integrated structural systems that operate at temperatures ranging from 1500 C to 3000 C, depending on the application. This paper will present recent advances in the development of hot structures, including development of environmentally durable, high temperature leading edges and control surfaces, integrated thermal protection systems, and repair technologies. The X-43A Mach-10 vehicle utilized carbon/carbon (C/C) leading edges on the nose, horizontal control surface, and vertical tail. The nose and vertical and horizontal tail leading edges were fabricated out of a 3:1 biased, high thermal conductivity C/C. The leading edges were coated with a three-layer coating comprised of a SiC conversion of the C/C, followed by a CVD layer of SiC, followed by a thin CVD layer of HfC. Work has also been performed on the development of an integrated structure and was focused on both hot and warm (insulated) structures and integrated fuselage/tank/TPS systems. The objective was to develop integrated multifunctional airframe structures that eliminate fragile external thermal-protection systems and incorporate the insulating function within the structure. The approach taken to achieve this goal was to develop candidate hypersonic airframe concepts, including structural arrangement, load paths, thermal-structural wall design, thermal accommodation features, and integration of major components, optimize thermalstructural configurations, and validate concepts through a building block test program and generate data to improve and validate analytical and design tools.

Fastrac Nozzle Design, Performance and Development

NASA Technical Reports Server (NTRS)

Peters, Warren; Rogers, Pat; Lawrence, Tim; Davis, Darrell; DAgostino, Mark; Brown, Andy

2000-01-01

With the goal of lowering the cost of payload to orbit, NASA/MSFC (Marshall Space Flight Center) researched ways to decrease the complexity and cost of an engine system and its components for a small two-stage booster vehicle. The composite nozzle for this Fastrac Engine was designed, built and tested by MSFC with fabrication support and engineering from Thiokol-SEHO (Science and Engineering Huntsville Operation). The Fastrac nozzle uses materials, fabrication processes and design features that are inexpensive, simple and easily manufactured. As the low cost nozzle (and injector) design matured through the subscale tests and into full scale hot fire testing, X-34 chose the Fastrac engine for the propulsion plant for the X-34. Modifications were made to nozzle design in order to meet the new flight requirements. The nozzle design has evolved through subscale testing and manufacturing demonstrations to full CFD (Computational Fluid Dynamics), thermal, thermomechanical and dynamic analysis and the required component and engine system tests to validate the design. The Fastrac nozzle is now in final development hot fire testing and has successfully accumulated 66 hot fire tests and 1804 seconds on 18 different nozzles.

Video File - NASA on a Roll Testing Space Launch System Flight Engines

NASA Image and Video Library

2017-08-09

Just two weeks after conducting another in a series of tests on new RS-25 rocket engine flight controllers for NASA’s Space Launch System (SLS) rocket, engineers at NASA’s Stennis Space Center in Mississippi completed one more hot-fire test of a flight controller on August 9, 2017. With the hot fire, NASA has moved a step closer in completing testing on the four RS-25 engines which will power the first integrated flight of the SLS rocket and Orion capsule known as Exploration Mission 1.

Hot surface temperatures of domestic appliances.

PubMed

Bassett, Malcolm; Arild, Anne-Helene

2002-09-01

Domestic appliances are burning people. In the European Union, accidents requiring hospital treatment due to burns from hot objects account for between 0 and 1% of all such accidents. Young children are particularly at risk. These reported accidents requiring hospital treatment are also likely to be a small proportion of the total number of burns from hot objects. There is a lack of hard evidence about the level of accidents, typical consumer expectation and use, and on the state of the art of appliances. Results of technical laboratory tests carried out on products are used to demonstrate the state of the art and also show how consumer expectations could be changing. Results of a survey into accidents, based on a written questionnaire following telephone contact, provide information on non-hospital cases. Results of tests on products show that there are significant differences in the temperatures of touchable surfaces, even in products of the same type. Typically, these differences are due to variations in design and/or materials of construction. Some products are hot enough to burn skin. Accident research indicates that non-hospital medical practices are treating burn injuries, which are therefore not being included into the current accident statistics. For products with the same function, some types of design or materials of construction are safer, with lower surface temperatures. Many product standards have no or unnecessarily high limits on surface temperatures. Many standards do not address the realities of who is using their products, for what purpose or where they are located. Some standards use unreasonable general limitations and exclusions that allow products with higher surface temperatures than they should have. Many standards rely on the experience factor for avoiding injury that is no longer valid, with the increased availability of safer products of the same type. A major field of work ahead is to carry out more surveys and in-depth studies of non-fatal accidents and injuries.

Method and apparatus for determining weldability of thin sheet metal

DOEpatents

Goodwin, Gene M.; Hudson, Joseph D.

1988-01-01

A fixture is provided for testing thin sheet metal specimens to evaluate hot-cracking sensitivity for determining metal weldability on a heat-to-heat basis or through varying welding parameters. A test specimen is stressed in a first direction with a load selectively adjustable over a wide range and then a weldment is passed along over the specimen in a direction transverse to the direction of strain to evaluate the hot-cracking characteristics of the sheet metal which are indicative of the weldability of the metal. The fixture provides evaluations of hot-cracking sensitivity for determining metal weldability in a highly reproducible manner with minimum human error.

Hot section viewing system

NASA Technical Reports Server (NTRS)

Morey, W. W.

1983-01-01

The objective of the hot section viewing program is to develop a prototype optical system for viewing the interior of a gas turbine combustor during high temperature, high pressure operation in order to produce a visual record of some causes of premature hot section failures. The program began by identifying and analyzing system designs that would provide clearest images while being able to survive the hostile environment inside the combustion chamber. Different illumination methods and computer techniques for image enhancement and analysis were examined during a preliminary test phase. In the final phase of the program the prototype system was designed and fabricated and is currently being tested on a high pressure combustor rig.

Application of an Energy-Based Life Prediction Model to Bithermal and Thermomechanical Fatigue

NASA Technical Reports Server (NTRS)

Radhakrishnan, V. M.; Kalluri, Sreeramesh; Halford, Gary R.

1994-01-01

The inelastic hysteresis energy applied to the material in a cycle is used as the basis for predicting nonisothermal fatigue life of a wrought cobalt-base superalloy, Haynes 188, from isothermal fatigue data. Damage functions that account for hold-time effects and time-dependent environmental phenomena such as oxidation and hot corrosion are proposed in terms of the inelastic hysteresis energy per cycle. The proposed damage functions are used to predict the bithermal and thermomechanical fatigue lives of Haynes 188 between 316 and 760 C from isothermal fatigue data. Predicted fatigue lives of all but two of the nonisothermal tests are within a factor of 1.5 of the experimentally observed lives.

Protein-protein interface analysis and hot spots identification for chemical ligand design.

PubMed

Chen, Jing; Ma, Xiaomin; Yuan, Yaxia; Pei, Jianfeng; Lai, Luhua

2014-01-01

Rational design for chemical compounds targeting protein-protein interactions has grown from a dream to reality after a decade of efforts. There are an increasing number of successful examples, though major challenges remain in the field. In this paper, we will first give a brief review of the available methods that can be used to analyze protein-protein interface and predict hot spots for chemical ligand design. New developments of binding sites detection, ligandability and hot spots prediction from the author's group will also be described. Pocket V.3 is an improved program for identifying hot spots in protein-protein interface using only an apo protein structure. It has been developed based on Pocket V.2 that can derive receptor-based pharmacophore model for ligand binding cavity. Given similarities and differences between the essence of pharmacophore and hot spots for guiding design of chemical compounds, not only energetic but also spatial properties of protein-protein interface are used in Pocket V.3 for dealing with protein-protein interface. In order to illustrate the capability of Pocket V.3, two datasets have been used. One is taken from ASEdb and BID having experimental alanine scanning results for testing hot spots prediction. The other is taken from the 2P2I database containing complex structures of protein-ligand binding at the original protein-protein interface for testing hot spots application in ligand design.

Laboratory accelerated stripping simulator for hot mix asphalt.

DOT National Transportation Integrated Search

2005-01-18

Moisture susceptibility of hot mix asphalt (HMA) pavements continues to be a major pavement distress. Past research : has primarily focused on HMA stripping prevention through material component evaluation/testing and addition of : preventative addit...

Performance Testing of Hot-Mix Asphalt Aggregates

DOT National Transportation Integrated Search

1999-12-01

Hot mix asphalt (HMA) pavements are subject to thermal cracking, fatigue cracking, rutting, stripping, raveling, and freeze-thaw damage. Some of these distresses are directly affected by the choice of aggregates. Particle shape, surface texture, part...

Quality control analysis : part I : asphaltic concrete.

DOT National Transportation Integrated Search

1964-11-01

This report deals with the statistical evaluation of results from several hot mix plants to determine the pattern of variability with respect to bituminous hot mix characteristics. : Individual tests results when subjected to frequency distribution i...

A&M. Hot liquid waste building (TAN616). Interior of evaporator control ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot liquid waste building (TAN-616). Interior of evaporator control room. Date: 1962. INEEL negative no. 62-6824 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Sodium sulfate - Deposition and dissolution of silica

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.

1989-01-01

The hot-corrosion process for SiO2-protected materials involves deposition of Na2SO4 and dissolution of the protective SiO2 scale. Dew points for Na2SO4 deposition are calculated as a function of pressure, sodium content, and sulfur content. Expected dissolution regimes for SiO2 are calculated as a function of Na2SO4 basicity. Controlled-condition burner-rig tests on quartz verify some of these predicted dissolution regimes. The basicity of Na2SO4 is not always a simple function of P(SO3). Electrochemical measurements of an (Na2O) show that carbon creates basic conditions in Na2SO4, which explains the extensive corrosion of SiO2-protected materials containing carbon, such as SiC.

Temperature-induced changes in neuromuscular function: central and peripheral mechanisms.

PubMed

Goodman, D; Hancock, P A; Runnings, D W; Brown, S L

1984-10-01

Three series of experimental tests were conducted on subjects under both elevated and depressed thermal conditions. Tripartite series consisted of whole-body immersion excepting the head, whole-body immersion excepting the head and response limb, and immersion of the discrete-response limb. Measures of physiological and behavioural responses were made at sequential .4 degrees C changes during whole-body immersions and approximately 5 degrees C changes of water temperature during the immersion of a limb only. Results suggested that velocity of nerve conduction decreased with thermal depression. Premotor, motor, simple, and choice reaction times varied differentially as a function of the hot and cold conditions. Implications of these differential effects on neuromuscular function are examined with respect to person-machine performance in artificially induced or naturally occurring extremes of ambient temperature.

Modeling bistatic spectral measurements of temporally evolving reflected and emitted energy from a distant and receding target

NASA Astrophysics Data System (ADS)

Cusumano, Salvatore J.; Fiorino, Steven T.; Bartell, Richard J.; Krizo, Matthew J.; Bailey, William F.; Beauchamp, Rebecca L.; Marciniak, Michael A.

2011-01-01

The Air Force Institute of Technology's Center for Directed Energy developed the High Energy Laser End-to-End Operational Simulation (HELEEOS) model in part to quantify the performance variability in laser propagation created by the natural environment during dynamic engagements. As such, HELEEOS includes a fast-calculating, first principles, worldwide surface-to-100 km, atmospheric propagation, and characterization package. This package enables the creation of profiles of temperature, pressure, water vapor content, optical turbulence, atmospheric particulates, and hydrometeors as they relate to line-by-line layer transmission, path, and background radiance at wavelengths from the ultraviolet to radio frequencies. In the current paper an example of a unique high fidelity simulation of a bistatic, time-varying five band multispectral remote observation of energy delivered on a distant and receding test object is presented for noncloudy conditions with aerosols. The multispectral example emphasizes atmospheric effects using HELEEOS, the interaction of the energy and the test object, the observed reflectance, and subsequent hot spot generated. A model of a sensor suite located on the surface is included to collect the diffuse reflected in-band laser radiation and the emitted radiance of the hot spot in four separate and spatially offset midwave infrared and longwave infrared bands. Particular care is taken in modeling the bidirectional reflectance distribution function of the delivered energy/target interaction to account for both the coupling of energy into the test object and the changes in reflectance as a function of temperature. The architecture supports any platform-target-observer geometry, geographic location, season, and time of day, and it provides for correct contributions of the sky-earth background. The simulation accurately models the thermal response, kinetics, turbulence, base disturbance, diffraction, and signal-to-noise ratios.

Characteristics of volatile organic compounds (VOCs) from the evaporative emissions of modern passenger cars

NASA Astrophysics Data System (ADS)

Yue, Tingting; Yue, Xin; Chai, Fahe; Hu, Jingnan; Lai, Yitu; He, Liqang; Zhu, Rencheng

2017-02-01

Volatile organic compounds (VOCs) from vehicle evaporative emissions contribute substantially to photochemical air pollution. Yet, few studies of the characteristics of VOCs emitted from vehicle evaporative emissions have been published. We investigate the characteristics of 57 VOCs in hot soak, 24 h diurnal and 48 h diurnal emissions by applying the Sealed Housing Evaporative Determination unit (SHED) test to three modern passenger cars (one US Tier 2 and two China IV vehicles) using two different types of gasoline. The characteristics of the VOCs from the hot soak, 24 h diurnal and 48 h diurnal emissions were different due to their different emission mechanisms. In the hot soak emissions, toluene, isopentane/n-pentane, and 2,2,4-trimethylpentane were dominant species. In the 24 h and 48 h diurnal emissions, isopentane and n-pentane were dominant species. Toluene was the third most dominant component in the 24 h diurnal emissions but decreased by a mass of 42%-80% in the 48 h diurnal emissions. In the hot soak, 24 h diurnal and 48 h diurnal emissions, alkanes were generally the dominant hydrocarbons, followed by aromatics and olefins. However, owing to different evaporative emission mechanisms, the weight percentages of the aromatic hydrocarbons decreased and the weight percentages of the alkanes increased from the hot soak test to the 24 h diurnal and 48 h diurnal tests for each vehicle. The dominant contributors to the ozone formation potentials (OFPs) were also different in the hot soak, 24 h diurnal and 48 h diurnal emissions. The OFPs (g O3/g VOC) of the hot soak emissions were higher than those of the 24 h and 48 h diurnal emissions. In addition, the combined effect of decreasing the olefin and aromatic contents of gasoline on vehicle evaporative emissions was investigated. The aromatics all decreased substantially in the hot soak, 24 h and 48 h diurnal emissions, and the total masses of the VOCs and OFPs decreased, with the greatest reduction occurring in the hot soak emissions when the fuel aromatic and olefin contents were reduced.

The 2003 Goddard Rocket Replica Project: A Reconstruction of the World's First Functional Liquid Rocket System

NASA Technical Reports Server (NTRS)

Farr, R. A.; Elam, S. K.; Hicks, G. D.; Sanders, T. M.; London, J. R.; Mayne, A. W.; Christensen, D. L.

2003-01-01

As a part of NASA s 2003 Centennial of Flight celebration, engineers and technicians at Marshall Space Flight Center (MSFC), Huntsville, Alabama, in cooperation with the Alabama-Mississippi AIAA Section, have reconstructed historically accurate, functional replicas of Dr. Robert H. Goddard s 1926 first liquid- fuel rocket. The purposes of this project were to clearly understand, recreate, and document the mechanisms and workings of the 1926 rocket for exhibit and educational use, creating a vital resource for researchers studying the evolution of liquid rocketry for years to come. The MSFC team s reverse engineering activity has created detailed engineering-quality drawings and specifications describing the original rocket and how it was built, tested, and operated. Static hot-fire tests, as well as flight demonstrations, have further defined and quantified the actual performance and engineering actual performance and engineering challenges of this major segment in early aerospace history.

Functional genes and thermophilic microorganisms responsible for arsenite oxidation from the shallow sediment of an untraversed hot spring outlet.

PubMed

Yang, Ye; Mu, Yao; Zeng, Xian-Chun; Wu, Weiwei; Yuan, Jie; Liu, Yichen; Guoji, E; Luo, Feng; Chen, Xiaoming; Li, Hao; Wang, Jianing

2017-05-01

Hot Springs have unique geochemical features. Microorganisms-mediated arsenite oxidation is one of the major biogeochemical processes occurred in some hot springs. This study aimed to understand the diversities of genes and microorganisms involved in arsenite oxidation from the outlet of an untraversed hot spring located at an altitude of 4226 m. Microcosm assay indicated that the microbial community from the hot spring was able to efficiently oxidize As(III) using glucose, lactic acid, yeast extract or sodium bicarbonate as the sole carbon source. The microbial community contained 7 phyla of microorganisms, of which Proteobacteria and Firmicutes are largely dominant; this composition is unique and differs significantly from those of other described hot springs. Twenty one novel arsenite oxidase genes were identified from the samples, which are affiliated with the arsenite oxidase families of α-Proteobacteria, β-Proteobacteria or Archaea; this highlights the high diversity of the arsenite-oxidizing microorganisms from the hot spring. A cultivable arsenite-oxidizer Chelatococcu sp. GHS311 was also isolated from the sample using enrichment technique. It can completely convert 75.0 mg/L As(III) into As(V) in 18 days at 45 °C. The arsenite oxidase of GHS311 shares the maximal sequence identity (84.7%) to that of Hydrogenophaga sp. CL3, a non-thermotolerant bacterium. At the temperature lower than 30 °C or higher than 65 °C, the growth of this strain was completely inhibited. These data help us to better understand the diversity and functional features of the thermophilic arsenite-oxidizing microorganisms from hot springs.

Plasmonic hot electron transport drives nano-localized chemistry

PubMed Central

Cortés, Emiliano; Xie, Wei; Cambiasso, Javier; Jermyn, Adam S.; Sundararaman, Ravishankar; Narang, Prineha; Schlücker, Sebastian; Maier, Stefan A.

2017-01-01

Nanoscale localization of electromagnetic fields near metallic nanostructures underpins the fundamentals and applications of plasmonics. The unavoidable energy loss from plasmon decay, initially seen as a detriment, has now expanded the scope of plasmonic applications to exploit the generated hot carriers. However, quantitative understanding of the spatial localization of these hot carriers, akin to electromagnetic near-field maps, has been elusive. Here we spatially map hot-electron-driven reduction chemistry with 15 nm resolution as a function of time and electromagnetic field polarization for different plasmonic nanostructures. We combine experiments employing a six-electron photo-recycling process that modify the terminal group of a self-assembled monolayer on plasmonic silver nanoantennas, with theoretical predictions from first-principles calculations of non-equilibrium hot-carrier transport in these systems. The resulting localization of reactive regions, determined by hot-carrier transport from high-field regions, paves the way for improving efficiency in hot-carrier extraction science and nanoscale regio-selective surface chemistry. PMID:28348402

Chemical characteristics and anti-proliferation activities of Ganoderma tsugae polysaccharides.

PubMed

Chien, Rao-Chi; Yen, Ming-Tsung; Tseng, Yu-Hsiu; Mau, Jeng-Leun

2015-09-05

Polysaccharides were extracted by hot-water and hot-alkali from four forms of Ganoderma tsugae including mature and baby Ling chih, mycelium and filtrate. Different profiles of proximate composition and monosaccharide constituents, and element contents were found in the extracted polysaccharides from different extractions and different forms. The molecular weight distributions of polysaccharides were 2.8×10(4)-6.5×10(5)Da and their infrared spectra were comparable. The hot-alkali extracted polysaccharides exhibited better anti-proliferation on IMR32 cells than the hot-water extracted polysaccharides, which were in turn more effective than the hot-water extracts. Besides, most hot-water extracts and both extracted polysaccharides exhibited an anti-proliferation effect on Hep G2 cells. However, the hot-water extracts showed less effective in anti-proliferation of IMR32 and Hep G2 cells. Based on the anti-tumor effects, both polysaccharides could be prepared for use in the formulation of nutraceuticals and functional foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phthalate metabolite levels and menopausal hot flashes in midlife women.

PubMed

Ziv-Gal, Ayelet; Gallicchio, Lisa; Chiang, Catheryne; Ther, Sara N; Miller, Susan R; Zacur, Howard A; Dills, Russell L; Flaws, Jodi A

2016-04-01

During the menopausal transition, a woman's reproductive capacity declines, her hormone milieu changes, and her risk of hot flashes increases. Exposure to phthalates, which can be found in personal care products, can also result in altered reproductive function. Here, we investigated the associations between phthalate metabolite levels and midlife hot flashes. Eligible women (45-54 years of age) provided detailed information on hot flashes history and donated urine samples (n=195). Urinary phthalate metabolite levels were measured by HPLC-MS/MS. A higher total sum of phthalate metabolites commonly found in personal care products was associated with an increased risk of ever experiencing hot flashes (odds ratio (OR)=1.45; 95% confidence interval (CI)=1.07-1.96), hot flashes in the past 30days (OR=1.43; 95%CI=1.04-1.96), and more frequent hot flashes (OR=1.47; 95%CI=1.06-2.05). These data suggest that some phthalate exposures from personal care products are associated with menopausal hot flashes in women. Copyright © 2016 Elsevier Inc. All rights reserved.

Phthalate metabolite levels and menopausal hot flashes in midlife women

PubMed Central

Ziv-Gal, Ayelet; Gallicchio, Lisa; Chiang, Catheryne; Ther, Sara N.; Miller, Susan R.; Zacur, Howard A.; Dills, Russell L.; Flaws, Jodi A.

2016-01-01

During the menopausal transition, a woman’s reproductive capacity declines, her hormone milieu changes, and her risk of hot flashes increases. Exposure to phthalates, which can be found in personal-care products, can also result in altered reproductive function. Here, we investigated the associations between phthalate metabolite levels and midlife hot flashes. Eligible women (45–54 years of age) provided detailed information on hot flashes history and donated urine samples (n=195). Urinary phthalate metabolite levels were measured by HPLC-MS/MS. A higher total sum of phthalate metabolites commonly found in personal-care products was associated with an increased risk of ever experiencing hot flashes (odds ratio (OR)=1.45; 95% confidence interval (CI)= 1.07–1.96), hot flashes in the past 30 days (OR=1.43; 95%CI=1.04–1.96), and more frequent hot flashes (OR=1.47; 95%CI=1.06–2.05). These data suggest that some phthalate exposures from personal care products are associated with menopausal hot flashes in women. PMID:26867866

Difference in the action mechanism of radon inhalation and radon hot spring water drinking in suppression of hyperuricemia in mice.

PubMed

Etani, Reo; Kataoka, Takahiro; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori

2016-06-01

Although radon therapy is indicated for hyperuricemia, the underlying mechanisms of action have not yet been elucidated in detail. Therefore, we herein examined the inhibitory effects of radon inhalation and hot spring water drinking on potassium oxonate (PO)-induced hyperuricemia in mice. Mice inhaled radon at a concentration of 2000 Bq/m(3) for 24 h or were given hot spring water for 2 weeks. Mice were then administrated PO at a dose of 500 mg/kg. The results obtained showed that serum uric acid levels were significantly increased by the administration of PO. Radon inhalation or hot spring water drinking significantly inhibited elevations in serum uric acid levels through the suppression of xanthine oxidase activity in the liver. Radon inhalation activated anti-oxidative functions in the liver and kidney. These results suggest that radon inhalation inhibits PO-induced hyperuricemia by activating anti-oxidative functions, while hot spring water drinking may suppress PO-induced elevations in serum uric acid levels through the pharmacological effects of the chemical compositions dissolved in it. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

NASA Concludes Summer of RS-25 Testing

NASA Image and Video Library

2017-08-30

NASA engineers closed a summer of hot fire testing Aug. 30 for flight controllers on RS-25 engines that will help power the new Space Launch System (SLS) rocket being built to carry astronauts to deep-space destinations, including Mars. The 500-second hot fire an RS-25 engine flight controller unit on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Mississippi marked another step toward the nation’s return to human deep-space exploration missions.

Video File - RS-25 Engine Test 2017-08-30

NASA Image and Video Library

2017-08-30

NASA engineers closed a summer of hot fire testing Aug. 30 for flight controllers on RS-25 engines that will help power the new Space Launch System (SLS) rocket being built to carry astronauts to deep-space destinations, including Mars. The 500-second hot fire an RS-25 engine flight controller unit on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Mississippi marked another step toward the nation’s return to human deep-space exploration missions.

A Study of the Effects of Insulation Gaps on Building Heat Loss

DTIC Science & Technology

1980-04-01

the Guarded Hot Box. Figure 4, taken from ASTM C-236, shows the essential details of the Guarded Hot Box Test Apparatus. Details of the Johns - Manville Research...The walls are 1-3/- inches thick and are of sandwich construction, with a core of 2 pcf polyvinyl-chloride foam ( Johns - Manville Vinylcel) with faces...Council of Canada (NRC) ane at the Johns - Manville Research Center, was installed and tested as a wall. The test history of that pane] is shown in Table 3

Raising Test Scores vs. Teaching Higher Order Thinking (HOT): Senior Science Teachers' Views on How Several Concurrent Policies Affect Classroom Practices

ERIC Educational Resources Information Center

Zohar, Anat; Alboher Agmon, Vered

2018-01-01

Purpose: This study investigates how senior science teachers viewed the effects of a Raising Test Scores policy and its implementation on instruction of higher order thinking (HOT), and on teaching thinking to students with low academic achievements. Background: The study was conducted in the context of three concurrent policies advocating: (a)…

HOT CELL BUILDING, TRA632, INTERIOR. WRIGHT 3TON HOIST ON EAST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. WRIGHT 3-TON HOIST ON EAST SIDE OF CELL 2. SIGN AT LEFT OF VIEW SAYS, "...DO NOT BRING FISSILE MATERIAL INTO AREA WITHOUT APPROVAL." CAMERA FACES NORTHWEST. INL NEGATIVE NO. HD46-29-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Uniform test method for the measurement of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water heaters). 431.106 Section 431.106 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL...

10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Uniform test method for the measurement of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water heaters). 431.106 Section 431.106 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL...

10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Uniform test method for the measurement of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water heaters). 431.106 Section 431.106 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL...

10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Uniform test method for the measurement of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water heaters). 431.106 Section 431.106 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL...

Disturbance Impacts on Thermal Hot Spots and Hot Moments at the Peatland-Atmosphere Interface

NASA Astrophysics Data System (ADS)

Leonard, R. M.; Kettridge, N.; Devito, K. J.; Petrone, R. M.; Mendoza, C. A.; Waddington, J. M.; Krause, S.

2018-01-01

Soil-surface temperature acts as a master variable driving nonlinear terrestrial ecohydrological, biogeochemical, and micrometeorological processes, inducing short-lived or spatially isolated extremes across heterogeneous landscape surfaces. However, subcanopy soil-surface temperatures have been, to date, characterized through isolated, spatially discrete measurements. Using spatially complex forested northern peatlands as an exemplar ecosystem, we explore the high-resolution spatiotemporal thermal behavior of this critical interface and its response to disturbances by using Fiber-Optic Distributed Temperature Sensing. Soil-surface thermal patterning was identified from 1.9 million temperature measurements under undisturbed, trees removed and vascular subcanopy removed conditions. Removing layers of the structurally diverse vegetation canopy not only increased mean temperatures but it shifted the spatial and temporal distribution, range, and longevity of thermal hot spots and hot moments. We argue that linking hot spots and/or hot moments with spatially variable ecosystem processes and feedbacks is key for predicting ecosystem function and resilience.

Multiphysical FE-analysis of a front-end bending phenomenon in a hot strip mill

NASA Astrophysics Data System (ADS)

Ilmola, Joonas; Seppälä, Oskari; Leinonen, Olli; Pohjonen, Aarne; Larkiola, Jari; Jokisaari, Juha; Putaansuu, Eero

2018-05-01

In hot steel rolling processes, a slab is generally rolled to a transfer bar in a roughing process and to a strip in a hot strip rolling process. Over several rolling passes the front-end may bend upward or downward due to asymmetrical rolling conditions causing entry problems in the next rolling pass. Many different factors may affect the front-end bending phenomenon and are very challenging to measure. Thus, a customized finite element model is designed and built to simulate the front-end bending phenomenon in a hot strip rolling process. To simulate the functioning of the hot strip mill precisely, automated controlling logic of the mill must be considered. In this paper we studied the effect of roll bite friction conditions and amount of reduction on the front-end bending phenomenon in a hot strip rolling process.

Gravitational Lensing Effect on the Two-Point Correlation of Hot Spots in the Cosmic Microwave Background.

PubMed

Takada; Komatsu; Futamase

2000-04-20

We investigate the weak gravitational lensing effect that is due to the large-scale structure of the universe on two-point correlations of local maxima (hot spots) in the two-dimensional sky map of the cosmic microwave background (CMB) anisotropy. According to the Gaussian random statistics, as most inflationary scenarios predict, the hot spots are discretely distributed, with some characteristic angular separations on the last scattering surface that are due to oscillations of the CMB angular power spectrum. The weak lensing then causes pairs of hot spots, which are separated with the characteristic scale, to be observed with various separations. We found that the lensing fairly smooths out the oscillatory features of the two-point correlation function of hot spots. This indicates that the hot spot correlations can be a new statistical tool for measuring the shape and normalization of the power spectrum of matter fluctuations from the lensing signatures.

Transcriptional specificity in various p53-mutant cells.

PubMed

Okaichi, Kumio; Izumi, Nanaka; Takamura, Yuma; Fukui, Shoichi; Kudo, Takashi

2013-03-01

Mutation of the tumor suppressor gene p53 is the most common genetic alteration observed in human tumors. However, the relationship between the mutation point of p53 and the transcriptional specificity is not so obvious. We prepared Saos-2 cells with various mutations of p53 that are found in human tumors, and examined the resulting transcriptional alterations in the cells. Loss of function and gain of function were observed in all p53 mutants. Hot-spot mutations of p53 are frequently found in tumor cells. We compared hot-spot mutations and other mutations of p53 and found that a more than 2-fold transcription of CADPS2, PIWIL4 and TRIM9 was induced by hot spot mutations, but not by other mutations. As PIWIL4 suppresses the p16(INK4A) and ARF pathway, restraining cell growth and genomic instability, induction of PIWIL4 expression may be one reason why hot-spot mutations are frequently found in tumor cells.

Hot-spot durability testing of amorphous cells and modules

NASA Technical Reports Server (NTRS)

Gonzalez, Charles; Jetter, Elizabeth

1985-01-01

This paper discusses the results of a study to determine the hot-spot susceptibility of amorphous-silicon (a-Si) cells and modules, and to provide guidelines for reducing that susceptibility. Amorphous-Si cells are shown to have hot-spot susceptibility levels similar to crystalline-silicon (C-Si) cells. This premise leads to the fact that the same general guidelines must apply to protecting a-Si cells from hot-spot stressing that apply to C-Si cells. Recommendations are made on ways of reducing a-Si module hot-spot susceptibility including the traditional method of using bypass diodes and a new method unique to thin-film cells, limiting the string current by limiting cell area.

Leaf Oil Body Functions as a Subcellular Factory for the Production of a Phytoalexin in Arabidopsis1[W

PubMed Central

Shimada, Takashi L.; Takano, Yoshitaka; Shimada, Tomoo; Fujiwara, Masayuki; Fukao, Yoichiro; Mori, Masashi; Okazaki, Yozo; Saito, Kazuki; Sasaki, Ryosuke; Aoki, Koh; Hara-Nishimura, Ikuko

2014-01-01

Oil bodies are intracellular structures present in the seed and leaf cells of many land plants. Seed oil bodies are known to function as storage compartments for lipids. However, the physiological function of leaf oil bodies is unknown. Here, we show that leaf oil bodies function as subcellular factories for the production of a stable phytoalexin in response to fungal infection and senescence. Proteomic analysis of oil bodies prepared from Arabidopsis (Arabidopsis thaliana) leaves identified caleosin (CLO3) and α-dioxygenase (α-DOX1). Both CLO3 and α-DOX1 were localized on the surface of oil bodies. Infection with the pathogenic fungus Colletotrichum higginsianum promoted the formation of CLO3- and α-DOX1-positive oil bodies in perilesional areas surrounding the site of infection. α-DOX1 catalyzes the reaction from α-linolenic acid (a major fatty acid component of oil bodies) to an unstable compound, 2-hydroperoxy-octadecatrienoic acid (2-HPOT). Intriguingly, a combination of α-DOX1 and CLO3 produced a stable compound, 2-hydroxy-octadecatrienoic acid (2-HOT), from α-linolenic acid. This suggests that the colocalization of α-DOX1 and CLO3 on oil bodies might prevent the degradation of unstable 2-HPOT by efficiently converting 2-HPOT into the stable compound 2-HOT. We found that 2-HOT had antifungal activity against members of the genus Colletotrichum and that infection with C. higginsianum induced 2-HOT production. These results defined 2-HOT as an Arabidopsis phytoalexin. This study provides, to our knowledge, the first evidence that leaf oil bodies produce a phytoalexin under a pathological condition, which suggests a new mechanism of plant defense. PMID:24214535

Validation of hot-poured crack sealant performance-based guidelines.

DOT National Transportation Integrated Search

2017-06-01

This report summarizes a comprehensive research effort to validate thresholds for performance-based guidelines and : grading system for hot-poured asphalt crack sealants. A series of performance tests were established in earlier research and : includ...

A&M. Hot liquid waste building (TAN616) under construction. Camera facing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot liquid waste building (TAN-616) under construction. Camera facing northeast. Date: November 25, 1953. INEEL negative no. 9232 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Correlation of Wissler Human Thermal Model Blood Flow and Shiver Algorithms

NASA Technical Reports Server (NTRS)

Bue, Grant; Makinen, Janice; Cognata, Thomas

2010-01-01

The Wissler Human Thermal Model (WHTM) is a thermal math model of the human body that has been widely used to predict the human thermoregulatory response to a variety of cold and hot environments. The model has been shown to predict core temperature and skin temperatures higher and lower, respectively, than in tests of subjects in crew escape suit working in a controlled hot environments. Conversely the model predicts core temperature and skin temperatures lower and higher, respectively, than in tests of lightly clad subjects immersed in cold water conditions. The blood flow algorithms of the model has been investigated to allow for more and less flow, respectively, for the cold and hot case. These changes in the model have yielded better correlation of skin and core temperatures in the cold and hot cases. The algorithm for onset of shiver did not need to be modified to achieve good agreement in cold immersion simulations

Effects of surface chemistry on hot corrosion life

NASA Technical Reports Server (NTRS)

Fryxell, R. E.

1984-01-01

Baseline burner rig hot corrosion with Udimet 700, Rene' 80; uncoated and with RT21, Codep, or NiCoCrAlY coatings were tested. Test conditions are: 900C, hourly thermal cycling, 0.5 ppm sodium as NaCl in the gas stream, velocity 0.3 Mach. The uncoated alloys exhibited substantial typical sulfidation in the range of 140 to 170 hours. The aluminide coatings show initial visual evidence of hot corrosion at about 400 hours, however, there is no such visual evidence for the NiCoCrAlY coatings. The turbine components show sulfidation. The extent of this distress appeared to be inversely related to the average length of mission which may, reflect greater percentage of operating time near ground level or greater percentage of operation time at takeoff conditions (higher temperatures). In some cases, however, the location of maximum distress did not exhibit the structural features of hot corrosion.

Monte Carlo tests of the ELIPGRID-PC algorithm

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

Davidson, J.R.

1995-04-01

The standard tool for calculating the probability of detecting pockets of contamination called hot spots has been the ELIPGRID computer code of Singer and Wickman. The ELIPGRID-PC program has recently made this algorithm available for an IBM{reg_sign} PC. However, no known independent validation of the ELIPGRID algorithm exists. This document describes a Monte Carlo simulation-based validation of a modified version of the ELIPGRID-PC code. The modified ELIPGRID-PC code is shown to match Monte Carlo-calculated hot-spot detection probabilities to within {plus_minus}0.5% for 319 out of 320 test cases. The one exception, a very thin elliptical hot spot located within a rectangularmore » sampling grid, differed from the Monte Carlo-calculated probability by about 1%. These results provide confidence in the ability of the modified ELIPGRID-PC code to accurately predict hot-spot detection probabilities within an acceptable range of error.« less

Criticality conditions of heterogeneous energetic materials under shock loading

NASA Astrophysics Data System (ADS)

Nassar, Anas; Rai, Nirmal Kumar; Sen, Oishik; Udaykumar, H. S.

2017-06-01

Shock interaction with the microstructural heterogeneities of energetic materials can lead to the formation of locally heated regions known as hot spots. These hot spots are the potential sites where chemical reaction may be initiated. However, the ability of a hot spot to initiate chemical reaction depends on its size, shape and strength (temperature). Previous study by Tarver et al. has shown that there exists a critical size and temperature for a given shape (spherical, cylindrical, and planar) of the hot spot above which reaction initiation is imminent. Tarver et al. assumed a constant temperature variation in the hot spot. However, the meso-scale simulations show that the temperature distribution within a hot spot formed from processes such as void collapse is seldom constant. Also, the shape of a hot spot can be arbitrary. This work is an attempt towards development of a critical hot spot curve which is a function of loading strength, duration and void morphology. To achieve the aforementioned goal, mesoscale simulations are conducted on porous HMX material. The process is repeated for different loading conditions and void sizes. The hot spots formed in the process are examined for criticality depending on whether they will ignite or not. The metamodel is used to obtain criticality curves and is compared with the critical hot spot curve of Tarver et al.

INNOVATIVE INSTRUMENTATION AND ANALYSIS OF THE TEMPERATURE MEASUREMENT FOR HIGH TEMPERATURE GASIFICATION

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

Seong W. Lee

During this reporting period, the literature survey including the gasifier temperature measurement literature, the ultrasonic application and its background study in cleaning application, and spray coating process are completed. The gasifier simulator (cold model) testing has been successfully conducted. Four factors (blower voltage, ultrasonic application, injection time intervals, particle weight) were considered as significant factors that affect the temperature measurement. The Analysis of Variance (ANOVA) was applied to analyze the test data. The analysis shows that all four factors are significant to the temperature measurements in the gasifier simulator (cold model). The regression analysis for the case with the normalizedmore » room temperature shows that linear model fits the temperature data with 82% accuracy (18% error). The regression analysis for the case without the normalized room temperature shows 72.5% accuracy (27.5% error). The nonlinear regression analysis indicates a better fit than that of the linear regression. The nonlinear regression model's accuracy is 88.7% (11.3% error) for normalized room temperature case, which is better than the linear regression analysis. The hot model thermocouple sleeve design and fabrication are completed. The gasifier simulator (hot model) design and the fabrication are completed. The system tests of the gasifier simulator (hot model) have been conducted and some modifications have been made. Based on the system tests and results analysis, the gasifier simulator (hot model) has met the proposed design requirement and the ready for system test. The ultrasonic cleaning method is under evaluation and will be further studied for the gasifier simulator (hot model) application. The progress of this project has been on schedule.« less

Hot carrier-assisted intrinsic photoresponse in graphene.

PubMed

Gabor, Nathaniel M; Song, Justin C W; Ma, Qiong; Nair, Nityan L; Taychatanapat, Thiti; Watanabe, Kenji; Taniguchi, Takashi; Levitov, Leonid S; Jarillo-Herrero, Pablo

2011-11-04

We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation (of wavelength 850 nanometers) at the p-n interface leads to striking six-fold photovoltage patterns as a function of bottom- and top-gate voltages. These patterns, together with the measured spatial and density dependence of the photoresponse, provide strong evidence that nonlocal hot carrier transport, rather than the photovoltaic effect, dominates the intrinsic photoresponse in graphene. This regime, which features a long-lived and spatially distributed hot carrier population, may offer a path to hot carrier-assisted thermoelectric technologies for efficient solar energy harvesting.

Deducing material quality in cast and hot-forged steels by new bending test

NASA Astrophysics Data System (ADS)

Valberg, Henry; Langøy, Morten; Nedreberg, Mette; Helvig, Torgeir

2017-10-01

A special bend test has been developed and applied for the purpose of characterization and comparison of the material ductility in crankpin steel discs manufactured by casting, or casting subsequently followed by hot open-die forging (ODF) or closed-die forging (CDF). The bending test specimen consists of a small rectangular plate of material with a round hole cut out in the middle. The "eye-shape" specimens were cut out from various positions either near to the surface of, or from the interior of the discs. The test method revealed differences in ductility for the investigated materials, and for different depth positions inside the discs. The roughening of the specimen surface on the top-side of the specimen bend also varied dependent on the processing method for the material. Current results show that this test method is useful for evaluation of material quality in differently processed material. Experimental bend test results are presented for differently processed variants of the same material, i.e., crankpin discs either made by solely casting or casting subsequently followed by hot working either by ODF or CDF.

Effects of Hot Streak Shape on Rotor Heating in a High-Subsonic Single-Stage Turbine

NASA Technical Reports Server (NTRS)

Dorney, Daniel J.; Gundy-Burlet, Karen L.; Norvig, Peter (Technical Monitor)

1999-01-01

Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location (clocking) of the hot streak relative to the first-stage vane airfoils can be used to minimize the adverse effects of the hot streak. The effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have also been evaluated. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine operating in high subsonic flow. In addition to a simulation of the baseline turbine, simulations have been performed for circular and elliptical hot streaks of varying sizes in an effort to represent different combustor designs. The predicted results for the baseline simulation show good agreement with the available experimental data. The results of the hot streak simulations indicate: that a) elliptical hot streaks mix more rapidly than circular hot streaks, b) for small hot streak surface area the average rotor temperature is not a strong function of hot streak temperature ratio or shape, and c) hot streaks with larger surface area interact with the secondary flows at the rotor hub endwall, generating an additional high temperature region.

A&M. A&M building (TAN607). Camera facing east. From left to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. A&M building (TAN-607). Camera facing east. From left to right, pool section, hot shop, cold shop, and machine shop. Biparting doors to hot shop are in open position behind shroud. Four rail tracks lead to hot shop and cold shop. Date: August 20, 1954. INEEL negative no. 11706 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

A&M. TAN607 third floor plan for hot shop. Crane control ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. TAN-607 third floor plan for hot shop. Crane control rooms and their shielding windows. Plenum. Wall rack for manipulators in hot shop. Ralph M. Parsons 902-3-ANP-607-A 103. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 034-0607-00-693-106755 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

The Effect of Stress and Hot Corrosion on Nickel-Base Superalloys

DTIC Science & Technology

1985-03-01

in a degradation of material properties and reduced component life. Allen and Whitlow(6). stated that superalloys in combustion turbine environments...pins are tested in combustion gas streams at elevated temperatures. A hot corrosion environment is usually simulated by burning a sulfur-containing fuel...corrosion attack frequently observed on combustion turbine blades retrieved from service. Figure 1 shows the effect of salt thickness on hot corrosion

Key paediatric messages from Amsterdam

PubMed Central

Barben, Jürg; Bohlin, Kajsa; Everard, Mark L.; Hall, Graham; Pijnenburg, Mariëlle; Priftis, Kostas N.; Rusconi, Franca; Midulla, Fabio

2016-01-01

The Paediatric Assembly of the European Respiratory Society (ERS) maintained its high profile at the 2015 ERS International Congress in Amsterdam. There were symposia on preschool wheeze, respiratory sounds and cystic fibrosis; an educational skills workshop on paediatric respiratory resuscitation; a hot topic session on risk factors and early origins of respiratory diseases; a meet the expert session on paediatric lung function test reference values; and the annual paediatric grand round. In this report the Chairs of the Paediatric Assembly's Groups highlight the key messages from the abstracts presented at the Congress. PMID:27730186

Calculation of the fast ion tail distribution for a spherically symmetric hot spot

NASA Astrophysics Data System (ADS)

McDevitt, C. J.; Tang, X.-Z.; Guo, Z.; Berk, H. L.

2014-10-01

The fast ion tail for a spherically symmetric hot spot is computed via the solution of a simplified Fokker-Planck collision operator. Emphasis is placed on describing the energy scaling of the fast ion distribution function in the hot spot as well as the surrounding cold plasma throughout a broad range of collisionalities and temperatures. It is found that while the fast ion tail inside the hot spot is significantly depleted, leading to a reduction of the fusion yield in this region, a surplus of fast ions is observed in the neighboring cold plasma region. The presence of this surplus of fast ions in the neighboring cold region is shown to result in a partial recovery of the fusion yield lost in the hot spot.

Calculation of recovery plasticity in multistage hot forging under isothermal conditions.

PubMed

Zhbankov, Iaroslav G; Perig, Alexander V; Aliieva, Leila I

2016-01-01

A widely used method for hot forming steels and alloys, especially heavy forging, is the process of multistage forging with pauses between stages. The well-known effect which accompanies multistage hot forging is metal plasticity recovery in comparison with monotonic deformation. A method which takes into consideration the recovery of plasticity in pauses between hot deformations of a billet under isothermal conditions is proposed. This method allows the prediction of billet forming limits as a function of deformation during the forging stage and the duration of the pause between the stages. This method takes into account the duration of pauses between deformations and the magnitude of subdivided deformations. A hot isothermal upsetting process with pauses was calculated by the proposed method. Results of the calculations have been confirmed with experimental data.

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

Binder, I.

TiC/Ni compositions with 10, 20, and 40 percent nickel were tested for transverse rupture strengths up to 1600 deg C. Transverse bend, cantilever beam, hot deformation, and hot extrusion experiments were performed in order to study the onset of plastic deformation. These materials were plastically deformed, and their microstructures were studied to learn about the mode of deiormation, plastic flow of the nickel binder, and alignment of the carbide grains. Other refractory hardmetal compositions, both single phase and cemented, were tested in transverse rupture up to 1600 deg C and were also subjected to various forms of hot deformation. Transversemore » strength peaks, versus temperature, were found for each material in the range 800 to 1500 deg C. Reasons for this behavior are developed. Microstructures of these materials were examined in connection with the strength tests and deformation studies. (auth)« less

Influence of oxcarbazepine on the antinociceptive action of morphine and metamizole in mice.

PubMed

Pakulska, Wanda; Czarnecka, Elzbieta

2009-01-01

Numerous methods of management applied in order to obtain higher therapeutic efficacy of drugs with minimum adverse effects include taking advantage of interactions taking place between individual agents. Analgesics are combined with drugs belonging to other therapeutic groups, including, more and more frequently, antiepileptic agents. The influence of oxcarbazepine (10 mg/kg) on the antinociceptive effect of morphine (10 mg/kg) and metamizole (500 mg/kg) was investigated in mice using the hot-plate and tail-flick tests. All drugs were injected intraperitoneally (i.p.). Oxcarbazepine was administered 30 min prior to the injection of analgesic drugs. The reactions to noxious stimuli were measured 30, 60 and 90 min after the administration of an analgesic. The study was further conducted for 10 days with repeated drug doses. Single administration of oxcarbazepine enhanced the antinociceptive effect of a single dose of morphine, and 10-day administration led to a decrease of morphine tolerance in the hot-plate test. Oxcarbazepine administered in a single dose did not affect significantly the antinociceptive effect of metamizole in either of the tests. Multiple administration of oxcarbazepine enhanced the antinociceptive effect of metamizole in the hot-plate test. Oxcarbazepine alone, administered in a single and repeated doses, demonstrated an antinociceptive effect, but only for the hot-plate test, which indicates involvement of supraspinal structures in antinociception.

Field trials of asphalt rubber hot mix in Virginia.

DOT National Transportation Integrated Search

1995-01-01

Four test sections using asphalt rubber hot mix were placed in Virginia during the period of 1990 through 1993. The purpose of these installations was to familiarize both contractors and Virginia Department of Transportation (VDOT) personnel with the...

5. VIEW TO THE SOUTHEAST OF THE HOT BAY AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW TO THE SOUTHEAST OF THE HOT BAY AND ATTACHED OPERATING GALLERIES ALONG THE WEST SIDE OF THE BAY. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV

Influence of the cooling method on the structure of 55AlZn coatings

NASA Astrophysics Data System (ADS)

Mendala, J.

2011-05-01

In metallization processes, metals or metal alloys are used which have a low melting point and good anticorrosion properties. Moreover, they must form durable intermetallic compounds with iron or its alloys. The most common hot-dip metallization technology involves galvanizing, however, molten multi-component metal alloys are used as well. An addition of aluminium to the zinc bath causes an increase in corrosion resistance of the obtained coatings. The article presents results of tests of obtaining coatings by the batch hot-dip method in an 55AlZn bath. Kinetics of the coating growth in the tested alloys were determined in the changeable conditions of bath temperature, dip time and type of cooling. The structure of coatings and their phase composition were revealed. As a result of the tests performed, it has been found that an increase in total thickness of the coatings as a function of the dipping time at a constant temperature is almost of a parabolic nature, whereas an increase in the transient layer is of a linear nature. The structure was identified by the XRD analysis and the morphology of the coatings was tested by means of SEM. It has been found that the cooling process with the use of higher rates of cooling causes a size reduction of the structure in the outer layer and a reduction of thickness of both the intermediate diffusion layer and the whole coating by ca. 25 %.

Milestones Towards Hot CMC Structures for Operational Space Rentry Vehicles

NASA Astrophysics Data System (ADS)

Hald, H.; Weihs, H.; Reimer, T.

2002-01-01

Hot structures made of ceramic matrix composites (CMC) for space reentry vehicles play a key role regarding feasibility of advanced and reusable future space transportation systems. Thus realization of applicable flight hardware concerning hot primary structures like a nose cap or body flaps and thermal protection systems (TPS) requires system competence w.r.t. sophisticated know how in material processing, manufacturing and qualification of structural components and in all aspects from process control, use of NDI techniques, arc jet testing, hot structure testing to flight concept validation. This goal has been achieved so far by DLR while following a dedicated development road map since more than a decade culminating at present in the supply of the nose cap system for NASA's X-38; the flight hardware has been installed successfully in October 2001. A number of unique hardware development milestones had to be achieved in the past to finally reach this level of system competence. It is the intention of this paper to highlight the most important technical issues and achievements from the essential projects and developments to finally provide a comprehensive insight into DLR's past and future development road map w.r.t. CMC hot structures for space reentry vehicles. Based on DLR's C/C-SiC material which is produced with the inhouse developed liquid silicon infiltration process (LSI) the development strategy first concentrated on basic material properties evaluation in various arc jet testing facilities. As soon as a basic understanding of oxidation and erosion mechanisms had been achieved further efforts concentrated on inflight verification of both materials and design concepts for hot structures. Consequently coated and uncoated C/C-SiC specimens were integrated into the ablative heat shield of Russian FOTON capsules and they were tested during two missions in 1992 and 1994. Following on, a hot structure experiment called CETEX which principally was a kind of a little nose cap had been developed and tested during the EXPRESS mission in 1995. These three flight tests were the first ones in Europe carried out with such a kind of material and hot structural concept and manifold lessons learned w.r.t. material behaviour and structural design performance under the severe environment conditions of ballistic capsule reentry could be achieved. Within an ESA program called FESTIP we developed a new design concept for a rigid surface TPS based on CMC's which should be adaptable to the outer side of a cryogenic tank structure of a future SSTO vehicle. Special TPS concept features are (flat) integral stiffened CMC panels, hot CMC fasteners for outside attachment capability, thermal displacement compensation, sealing and insulation, provision of a purge gap etc. Two test samples have been constructed and manufactured in close cooperation with industrial companies and finally they were tested very successfully under realistic thermal and mechanical loading conditions. A further key technology is high temperature fastening of shell like CMC components; here two new CMC based fastener concepts featuring a combination of screwing and riveting methods could be developed and qualified even under high temperature fatigue loads within ESA and national German programs. In addition high temperature testing technology has been matured over years and some extraordinary tests of components like the EMA bearing for the X-38 body flaps designed and manufactured by MAN-T could be tested very successfully. Finally these developments put DLR in the position to develop and provide the nose cap system for X-38 from NASA and some of the most demanding basic features will be highlighted briefly (details in a separate paper). Reflecting the described developments and considering near future programs like CRV and other ongoing experimental developments it is obvious that we now entered a state of transition from basic technology development towards operational use of such kind of materials and structures.

Tidd hot gas clean up program. Final report

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

NONE

This Final Report on the Tidd Hot Gas Clean Up Program covers the period from initial Proof-of-Concept testing in August, 1990, through final equipment inspections in May, 1995. The Tidd Hot Gas Clean Up (HGCU) system was installed in the Tidd Pressurized Fluidized Bed Combustion (PFBC) Demonstration Plant, which is the first utility-scale PFBC plant in the United States. Detailed design work on the project began in July, 1990, and site construction began in December, 1991. Initial operation of the system occurred in May, 1992, and the hot gas filter was commissioned in October, 1992. The test program ended inmore » March, 1995, when the Tidd Plant was shut down following its four-year test program. Section 1.0 of this report is an executive summary of the project covering the project background, system description, test results and conclusions. Section 2.0 is an introduction covering the program objectives and schedule. Section 3.0 provides detailed descriptions of the system and its major components. Section 4.0 provides detailed results of all testing including observations and posttest inspection results. Sections 5.0 and 6.0 list the program conclusions and recommendations, respectively. Appendix I is a report prepared by Southern Research Institute on the properties of Tidd PFBC ash sampled during the test program. Appendix II is a report prepared by Westinghouse STC on the performance of candle filter fail-safe regenerator devices.« less

Ground/Flight Correlation of Aerodynamic Loads with Structural Response

NASA Technical Reports Server (NTRS)

Mangalam, Arun S.; Davis, Mark C.

2009-01-01

Ground and flight tests provide a basis and methodology for in-flight characterization of the aerodynamic and structural performance through the monitoring of the fluid-structure interaction. The NF-15B flight tests of the Intelligent Flight Control System program provided a unique opportunity to test the correlation of aerodynamic loads with points of flow attaching and detaching from the surface, which are also known as flow bifurcation points, as observed in a previous wind tunnel test performed at the U.S. Air Force Academy (Colorado Springs, Colorado). Moreover, flight tests, along with the subsequent unsteady aerodynamic tests in the NASA Transonic Dynamics Tunnel (TDT), provide a basis using surface flow sensors as means of assessing the aeroelastic performance of flight vehicles. For the flight tests, the NF-15B tail was instrumented with hot-film sensors and strain gages for measuring root-bending strains. This data were gathered via selected sideslip maneuvers performed at level flight and subsonic speeds. The aerodynamic loads generated by the sideslip maneuver resulted in a structural response, which were then compared with the hot-film sensor signals. The hot-film sensor signals near the stagnation region were found to be highly correlated with the root-bending strains. For the TDT tests, a flexible wing section developed under the U.S. Air Force Research Lab SensorCraft program was instrumented with strain gages, accelerometers, and hot-film sensors at two span stations. The TDT tests confirmed the correlation between flow bifurcation points and the wing structural response to tunnel-generated gusts. Furthermore, as the wings structural modes were excited by the gusts, a gradual phase change between the flow bifurcation point and the structural mode occurred during a resonant condition.

Space transportation booster engine thrust chamber technology, large scale injector

NASA Technical Reports Server (NTRS)

Schneider, J. A.

1993-01-01

The objective of the Large Scale Injector (LSI) program was to deliver a 21 inch diameter, 600,000 lbf thrust class injector to NASA/MSFC for hot fire testing. The hot fire test program would demonstrate the feasibility and integrity of the full scale injector, including combustion stability, chamber wall compatibility (thermal management), and injector performance. The 21 inch diameter injector was delivered in September of 1991.

HOT CELL BUILDING, TRA632, INTERIOR. WINDOWED ROOM IS OFFICE; NEXT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. WINDOWED ROOM IS OFFICE; NEXT DOOR WAS DARKROOM, AND THIRD DOOR LED TO ANOTHER OFFICE. ALL ARE ALONG NORTH WALL OF BUILDING (ETR EXTENSION OF 1958). CAMERA FACES NORTHEAST. PUMICE BLOCK WALLS. INL NEGATIVE NO. HD46-29-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Effect of seasonal changes in use patterns and cold inlet water temperature on water-heating loads

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

Abrams, D.W.; Shedd, A.C.

This paper presents long-term test data obtained in 20 commercial buildings and 16 residential sites. The information illustrates the effects of variations in hot water load determinants and the effect on energy use. It also is useful as a supplement to the load profiles presented in the ASHRAE Handbooks and other design references. The commercial facilities include supermarkets, fast-food restaurants, full-service restaurants, commercial kitchens, a motel, a nursing home, a hospital, a bakery, and laundry facilities. The residential sites ere selected to provide test sites with higher-than-average hot water use. They include 13 single-family detached residences, one 14-unit apartment building,more » and two apartment laundries. Test data are available at measurement intervals of 1 minute for the residential sites and 15 minutes for the commercial sites. Summary data in tabular and graphical form are presented for average daily volumetric hot water use and cold inlet water temperature. Measured cold inlet water temperature and volumetric hot water use figures are compared to values typically used for design and analysis. Conclusions are offered regarding the effect of cold water inlet temperature and variations in hot water use on water-heating load and energy use. Recommendations for the use of the information presented in water-heating system design, performance optimization, and performance analysis conclude the paper.« less

How self-reported hot flashes may relate to affect, cognitive performance and sleep.

PubMed

Regestein, Quentin; Friebely, Joan; Schiff, Isaac

2015-08-01

To explain the controversy about whether midlife women who self-report hot flashes have relatively increased affective symptoms, poor cognitive performance or worse sleep. Retrospective data from 88 women seeking relief from bothersome day and night hot flashes were submitted to mixed linear regression modeling to find if estimated hot flashes, as measured by Women's Health Questionnaire (WHQ) items, or diary-documented hot flashes recorded daily, were associated with each other, or with affective, cognitive or sleep measures. Subjects averaged 6.3 daytime diary-documented hot flashes and 2.4 nighttime diary-documented hot flashes per 24h. Confounder-controlled diary-documented hot flashes but not estimated hot flashes were associated with increased Leeds anxiety scores (F=4.9; t=2.8; p=0.01) and Leeds depression scores (3.4; 2.5; 0.02), decreased Stroop Color-Word test performance (9.4; 3.5; 0.001), increased subjective sleep disturbance (effect size=0.83) and increased objective sleep disturbance (effect size=0.35). Hot flash effects were small to moderate in size. Univariate but not multivariate analyses revealed that all hot flash measures were associated with all affect measures. Different measures of hot flashes associated differently with affect, cognition and sleep. Only nighttime diary-document hot flash consistently correlated with any affect measures in multivariate analyses. The use of differing measures for hot flashes, affect, cognition and sleep may account for the continually reported inconsistencies in menopause study outcomes. This problem impedes forging a consensus on whether hot flashes correlate with neuropsychological symptoms. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The vibrational excitation of hot molecules by low energy electron impact

NASA Astrophysics Data System (ADS)

Kato, H.; Ohkawa, M.; Hoshino, M.; Campbell, L.; Brunger, M. J.; Tanaka, H.

2010-01-01

We report vibrational excitation functions and angular distributions for electron scattering from the ground vibrational quantum (000), the bending vibrational quantum (010) and the unresolved first bending overtone (020) and symmetric stretch (100) modes of the ground-electronic state in hot (750 K) carbon dioxide (CO2) molecules. The excitation function measurements were carried out at incident electron energies in the range of 1-9 eV, and at the electron scattering angles of 30°, 60°, 90° and 120°.

Hot gas ingestion characteristics and flow visualization of a vectored thrust STOVL concept

NASA Technical Reports Server (NTRS)

Johns, Albert L.; Neiner, George H.; Bencic, Timothy J.; Flood, Joseph D.; Amuedo, Kurt C.; Strock, Thomas W.; Williams, Ben R.

1990-01-01

A 9.2 percent scale short takeoff and vertical landing (STOVL) hot gas ingestion model was designed and built by McDonnell Douglas Corporation (MCAIR) and tested in the NASA Lewis Research Center 9- by 15-Foot Low Speed Wind Tunnel (LSWT). Hot gas ingestion, the entrainment of heated engine exhaust into the inlet flow field, is a key development issue for advanced short takeoff and vertical landing aircraft. The Phase 1 test program, conducted by NASA Lewis and McDonnell Douglas Corporation, evaluated the hot ingestion phenomena and control techniques and Phase 2 test program which was conducted by NASA Lewis are both reported. The Phase 2 program was conducted at exhaust nozzles temperatures up to 1460 R and utilized a sheet laser system for flow visualization of the model flow field in and out of ground effects. Hot gas ingestion levels were measured for the several forward nozzle splay configurations and with flow control/lift improvement devices which reduced the hot gas ingestion. The model support system had four degrees of freedom, heated high pressure air for nozzle flow, and a suction system exhaust for inlet flow. The headwind (freestream) velocity for Phase 1 was varied from 8 to 90 kn, with primary data taken in the 8 to 23 kn headwind velocity range. Phase 2 headwind velocity varied from 10 to 23 kn. Results of both Phase 1 and 2 are presented. A description of the model, facility, a new model support system, and a sheet laser illumination system are also provided. Results are presented over a range of main landing gear height (model height) above the ground plane at a 10 kn headwind velocity. The results contain the compressor face pressure and temperature distortions, total pressure recovery, compressor face temperature rise, and the environmental effects of the hot gas. The environmental effects include the ground plane temperature and pressure distributions, model airframe heating, and the location of the ground flow separation. Results from the sheet laser flow visualization test are also shown.

Space shuttle orbit maneuvering engine, reusable thrust chamber program. Task 6: Data dump hot fuel element investigation

NASA Technical Reports Server (NTRS)

Nurick, W. H.

1974-01-01

An evaluation of reusable thrust chambers for the space shuttle orbit maneuvering engine was conducted. Tests were conducted using subscale injector hot-fire procedures for the injector configurations designed for a regenerative cooled engine. The effect of operating conditions and fuel temperature on combustion chamber performance was determined. Specific objectives of the evaluation were to examine the optimum like-doublet element geometry for operation at conditions consistent with a fuel regeneratively cooled engine (hot fuel, 200 to 250 F) and the sensitivity of the triplet injector element to hot fuels.

High-Temperature Modal Survey of a Hot-Structure Control Surface

NASA Technical Reports Server (NTRS)

Spivey, Natalie D.

2011-01-01

Ground vibration tests are routinely conducted for supporting flutter analysis for subsonic and supersonic vehicles; however, for hypersonic vehicles, thermoelastic vibration testing techniques are neither well established nor routinely performed. New high-temperature material systems, fabrication technologies and high-temperature sensors expand the opportunities to develop advanced techniques for performing ground vibration tests at elevated temperatures. When high-temperature materials, which increase in stiffness when heated, are incorporated into a hot-structure that contains metallic components that decrease in stiffness when heated, the interaction between those materials can affect the hypersonic flutter analysis. A high-temperature modal survey will expand the research database for hypersonics and improve the understanding of this dual-material interaction. This report discusses the vibration testing of the carbon-silicon carbide Ruddervator Subcomponent Test Article, which is a truncated version of a full-scale hot-structure control surface. Two series of room-temperature modal test configurations were performed in order to define the modal characteristics of the test article during the elevated-temperature modal survey: one with the test article suspended from a bungee cord (free-free) and the second with it mounted on the strongback (fixed boundary). Testing was performed in the NASA Dryden Flight Research Center Flight Loads Laboratory Large Nitrogen Test Chamber.

Reliability of Ceramic Column Grid Array Interconnect Packages Under Extreme Temperatures

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni

2011-01-01

A paper describes advanced ceramic column grid array (CCGA) packaging interconnects technology test objects that were subjected to extreme temperature thermal cycles. CCGA interconnect electronic package printed wiring boards (PWBs) of polyimide were assembled, inspected nondestructively, and, subsequently, subjected to ex - treme-temperature thermal cycling to assess reliability for future deep-space, short- and long-term, extreme-temperature missions. The test hardware consisted of two CCGA717 packages with each package divided into four daisy-chained sections, for a total of eight daisy chains to be monitored. The package is 33 33 mm with a 27 27 array of 80%/20% Pb/Sn columns on a 1.27-mm pitch. The change in resistance of the daisy-chained CCGA interconnects was measured as a function of the increasing number of thermal cycles. Several catastrophic failures were observed after 137 extreme-temperature thermal cycles, as per electrical resistance measurements, and then the tests were continued through 1,058 thermal cycles to corroborate and understand the test results. X-ray and optical inspection have been made after thermal cycling. Optical inspections were also conducted on the CCGA vs. thermal cycles. The optical inspections were conclusive; the x-ray images were not. Process qualification and assembly is required to optimize the CCGA assembly, which is very clear from the x-rays. Six daisy chains were open out of seven daisy chains, as per experimental test data reported. The daisy chains are open during the cold cycle, and then recover during the hot cycle, though some of them also opened during the hot thermal cycle..

Environmental and functional benefits and trade-offs of hot in-place recycling treatment techniques : final project report.

DOT National Transportation Integrated Search

2016-12-01

Surface recycling is suitable for pavements with minor cracks limited to 25-50 mm in depth. Hot-in-place recycling (HIR) process includes drying and heating the upper layers, scarifying the soft asphalt, mixing the scarified material with a rejuvenat...

Using Innovative Technologies for Manufacturing Rocket Engine Hardware

NASA Technical Reports Server (NTRS)

Betts, E. M.; Eddleman, D. E.; Reynolds, D. C.; Hardin, N. A.

2011-01-01

Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As the United States enters into the next space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, rapid manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on NASA s Space Launch System (SLS) upper stage engine, J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator (GG) discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using a workhorse gas generator (WHGG) test fixture at MSFC's East Test Area, the duct was subjected to extreme J-2X hot gas environments during 7 tests for a total of 537 seconds of hot-fire time. The duct underwent extensive post-test evaluation and showed no signs of degradation. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

Hydrocarbon Liquid Production from Biomass via Hot-Vapor-Filtered Fast Pyrolysis and Catalytic Hydroprocessing of the Bio-oil

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

Elliott, Douglas C.; Wang, Huamin; French, Richard

2014-08-14

Hot-vapor filtered bio-oils were produced from two different biomass feedstocks, oak and switchgrass, and the oils were evaluated in hydroprocessing tests for production of liquid hydrocarbon products. Hot-vapor filtering reduced bio-oil yields and increased gas yields. The yields of fuel carbon as bio-oil were reduced by ten percentage points by hot-vapor filtering for both feedstocks. The unfiltered bio-oils were evaluated alongside the filtered bio-oils using a fixed bed catalytic hydrotreating test. These tests showed good processing results using a two-stage catalytic hydroprocessing strategy. Equal-sized catalyst beds, a sulfided Ru on carbon catalyst bed operated at 220°C and a sulfided CoMomore » on alumina catalyst bed operated at 400°C were used with the entire reactor at 100 atm operating pressure. The products from the four tests were similar. The light oil phase product was fully hydrotreated so that nitrogen and sulfur were below the level of detection, while the residual oxygen ranged from 0.3 to 2.0%. The density of the products varied from 0.80 g/ml up to 0.86 g/ml over the period of the test with a correlated change of the hydrogen to carbon atomic ratio from 1.79 down to 1.57, suggesting some loss of catalyst activity through the test. These tests provided the data needed to assess the suite of liquid fuel products from the process and the activity of the catalyst in relationship to the existing catalyst lifetime barrier for the technology.« less

How Do Earth-Sized, Short-Period Planets Form?

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-08-01

Matching theory to observation often requires creative detective work. In a new study, scientists have used a clever test to reveal clues about the birth of speedy, Earth-sized planets.Former Hot Jupiters?Artists impression of a hot Jupiter with an evaporating atmosphere. [NASA/Ames/JPL-Caltech]Among the many different types of exoplanets weve observed, one unusual category is that of ultra-short-period planets. These roughly Earth-sized planets speed around their host stars at incredible rates, with periods of less than a day.How do planets in this odd category form? One popular theory is that they were previously hot Jupiters, especially massive gas giants orbiting very close to their host stars. The close orbit caused the planets atmospheres to be stripped away, leaving behind only their dense cores.In a new study, a team of astronomers led by Joshua Winn (Princeton University) has found a clever way to test this theory.Planetary radius vs. orbital period for the authors three statistical samples (colored markers) and the broader sample of stars in the California Kepler Survey. [Winn et al. 2017]Testing MetallicitiesStars hosting hot Jupiters have an interesting quirk: they typically have metallicities that are significantly higher than an average planet-hosting star. It is speculated that this is because planets are born from the same materials as their host stars, and hot Jupiters require the presence of more metals to be able to form.Regardless of the cause of this trend, if ultra-short-period planets are in fact the solid cores of former hot Jupiters, then the two categories of planets should have hosts with the same metallicity distributions. The ultra-short-period-planet hosts should therefore also be weighted to higher metallicities than average planet-hosting stars.To test this, the authors make spectroscopic measurements and gather data for a sample of stellar hosts split into three categories:64 ultra-short-period planets (orbital period shorter than a day)23 hot Jupiters (larger than 4 times Earths radius and orbital period shorter than 10 days)243 small hot planets (smaller than 4 times Earths radius and orbital period between 1 and 10 days)They then compare the metallicity distributions of these three groups.Back to the Drawing BoardMetallicity distributions of the three statistical samples. The hot-Jupiter hosts (orange) have different distribution than the others; it is weighted more toward higher metallicities. [Winn et al. 2017]Winn and collaborators find that hosts of ultra-short-period planets do not have the same metallicity distribution as hot-Jupiter hosts; the metallicities of hot-Jupiter hosts are significantly higher. The metallicity distributions for hosts of ultra-short-period planets and hosts of small hot planets were statistically indistinguishable, however.These results strongly suggest that the majority of ultra-short-period planets are not the cores of former hot Jupiters. Alternative options include the possibility that they are the cores of smaller planets, such as sub-Neptunes, or that they are the short-period extension of the distribution of close-in, small rocky planets that formed by core accretion.This narrowing of the options for the formation of ultra-short-period planets is certainly intriguing. We can hope to further explore possibilities in the future after the Transiting Exoplanet Survey Satellites (TESS) comes online next year; TESS is expected to discover many more ultra-short-period planets that are too faint for Kepler to detect.CitationJoshua N. Winn et al 2017 AJ 154 60. doi:10.3847/1538-3881/aa7b7c

Metagenomic Analysis of Hot Springs in Central India Reveals Hydrocarbon Degrading Thermophiles and Pathways Essential for Survival in Extreme Environments

PubMed Central

Saxena, Rituja; Dhakan, Darshan B.; Mittal, Parul; Waiker, Prashant; Chowdhury, Anirban; Ghatak, Arundhuti; Sharma, Vineet K.

2017-01-01

Extreme ecosystems such as hot springs are of great interest as a source of novel extremophilic species, enzymes, metabolic functions for survival and biotechnological products. India harbors hundreds of hot springs, the majority of which are not yet explored and require comprehensive studies to unravel their unknown and untapped phylogenetic and functional diversity. The aim of this study was to perform a large-scale metagenomic analysis of three major hot springs located in central India namely, Badi Anhoni, Chhoti Anhoni, and Tattapani at two geographically distinct regions (Anhoni and Tattapani), to uncover the resident microbial community and their metabolic traits. Samples were collected from seven distinct sites of the three hot spring locations with temperature ranging from 43.5 to 98°C. The 16S rRNA gene amplicon sequencing of V3 hypervariable region and shotgun metagenome sequencing uncovered a unique taxonomic and metabolic diversity of the resident thermophilic microbial community in these hot springs. Genes associated with hydrocarbon degradation pathways, such as benzoate, xylene, toluene, and benzene were observed to be abundant in the Anhoni hot springs (43.5–55°C), dominated by Pseudomonas stutzeri and Acidovorax sp., suggesting the presence of chemoorganotrophic thermophilic community with the ability to utilize complex hydrocarbons as a source of energy. A high abundance of genes belonging to methane metabolism pathway was observed at Chhoti Anhoni hot spring, where methane is reported to constitute >80% of all the emitted gases, which was marked by the high abundance of Methylococcus capsulatus. The Tattapani hot spring, with a high-temperature range (61.5–98°C), displayed a lower microbial diversity and was primarily dominated by a nitrate-reducing archaeal species Pyrobaculum aerophilum. A higher abundance of cell metabolism pathways essential for the microbial survival in extreme conditions was observed at Tattapani. Taken together, the results of this study reveal a novel consortium of microbes, genes, and pathways associated with the hot spring environment. PMID:28105025

Construction and testing of crumb rubber modified hot mix asphalt pavement.

DOT National Transportation Integrated Search

1999-12-01

This research project was structured toward addressing that portion of ISTEA which directs the individual states to conduct studies on the recyclability of crumb rubber modified : (CRM) hot mix asphalt (HMA) and the technical performance of CRMHMA pa...

Precise method of compensating radiation-induced errors in a hot-cathode-ionization gauge with correcting electrode

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

Saeki, Hiroshi, E-mail: saeki@spring8.or.jp; Magome, Tamotsu, E-mail: saeki@spring8.or.jp

2014-10-06

To compensate pressure-measurement errors caused by a synchrotron radiation environment, a precise method using a hot-cathode-ionization-gauge head with correcting electrode, was developed and tested in a simulation experiment with excess electrons in the SPring-8 storage ring. This precise method to improve the measurement accuracy, can correctly reduce the pressure-measurement errors caused by electrons originating from the external environment, and originating from the primary gauge filament influenced by spatial conditions of the installed vacuum-gauge head. As the result of the simulation experiment to confirm the performance reducing the errors caused by the external environment, the pressure-measurement error using this method wasmore » approximately less than several percent in the pressure range from 10{sup −5} Pa to 10{sup −8} Pa. After the experiment, to confirm the performance reducing the error caused by spatial conditions, an additional experiment was carried out using a sleeve and showed that the improved function was available.« less

Photo-ionization of aluminum in a hot cavity for the selective production of exotic species project

NASA Astrophysics Data System (ADS)

Scarpa, D.; Makhathini, L.; Tomaselli, A.; Grassi, D.; Corradetti, S.; Manzolaro, M.; Vasquez, J.; Calderolla, M.; Rossignoli, M.; Monetti, A.; Andrighetto, A.; Prete, G.

2014-02-01

SPES (Selective Production of Exotic Species) is an Isotope Separation On-Line (ISOL) based accelerator facility that will be built in the Legnaro-Istituto Nazionale di Fisica Nucleare (INFN) Laboratory (Italy), intended to provide intense neutron-rich radioactive ion beams obtained by proton-induced fission of a uranium carbide (UCx) target. Besides this main target material, silicon carbide (SiC) will be the first to be used to deliver p-rich beams. This target will also validate the functionality of the SPES facility with aluminum beam as result of impinging SiC target with proton beam. In the past, off line studies on laser photoionization of aluminum have been performed in Pavia Spectroscopy Laboratory and in Laboratori Nazionali di Legnaro; a XeCl excimer laser was installed in order to test the laser ionization in the SPES hot cavity. With the new Wien filter installed a better characterization of the ionization process in terms of efficiency was performed and results are discussed.

Studies for aluminum photoionization in hot cavity for the selective production of exotic species projecta)

NASA Astrophysics Data System (ADS)

Scarpa, D.; Vasquez, J.; Tomaselli, A.; Grassi, D.; Biasetto, L.; Cavazza, A.; Corradetti, S.; Manzolaro, M.; Montano, J.; Andrighetto, A.; Prete, G.

2012-02-01

Selective production of exotic species (SPES) is an ISOL-based accelerator facility that will be built in the Legnaro INFN Laboratory (Italy), intended to provide an intense neutron-rich radioactive ion beams obtained by proton induced fission of an uranium carbide target. Beside this main target, a silicon carbide (SiC) target will the first to be used to deliver some p-rich beams. This target will validate also the functionality of the SPES facility with aluminum beam as result of hitting SiC target with protons. In the past off-line studies on laser photoionization of aluminum have performed in Pavia Spectroscopy Laboratory and in Laboratori Nazionali di Legnaro where, recently, a XeCl excimer laser was installed in order to test the laser ionization in the SPES hot cavity. Results are promising to justify further studies with this technique, aiming a better characterization of the SPES ion extraction capability under laser photoionization.

Dynamic Recrystallization Behavior of AISI 422 Stainless Steel During Hot Deformation Processes

NASA Astrophysics Data System (ADS)

Ahmadabadi, R. Mohammadi; Naderi, M.; Mohandesi, J. Aghazadeh; Cabrera, Jose Maria

2018-02-01

In this work, hot compression tests were performed to investigate the dynamic recrystallization (DRX) process of a martensitic stainless steel (AISI 422) at temperatures of 950, 1000, 1050, 1100 and 1150 °C and strain rates of 0.01, 0.1 and 1 s-1. The dependency of strain-hardening rate on flow stress was used to estimate the critical stress for the onset of DRX. Accordingly, the critical stress to peak stress ratio was calculated as 0.84. Moreover, the effect of true strain was examined by fitting stress values to an Arrhenius type constitutive equation, and then considering material constants as a function of strain by using a third-order polynomial equation. Finally, two constitutive models were used to investigate the competency of the strain-dependent constitutive equations to predict the flow stress curves of the studied steel. It was concluded that one model offers better precision on the flow stress values after the peak stress, while the other model gives more accurate results before the peak stress.

Menopausal Hot Flashes and White Matter Hyperintensities

PubMed Central

Thurston, Rebecca C.; Aizenstein, Howard J.; Derby, Carol A.; Sejdić, Ervin; Maki, Pauline M.

2015-01-01

Objective Hot flashes are the classic menopausal symptom. Emerging data links hot flashes to cardiovascular disease (CVD) risk, yet how hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes - measured via physiologic monitor and self-report - and white matter hyperintensities (WMH) among midlife women. Methods Twenty midlife women ages 40-60 without clinical CVD, with their uterus and both ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy and questionnaires to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Test of a priori hypotheses regarding relations between physiologically-monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models. Results More physiologically-monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index [beta(standard error)=.0002 (.0001), p=.03]. Findings persisted controlling for sleep characteristics and additional CVD risk factors. No relations were observed for self-reported hot flashes. Conclusions More physiologically-monitored hot flashes during sleep were associated with greater WMH burden among midlife women free of clinical CVD. Results suggest that relations between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health. PMID:26057822

Ground/Flight Correlation of Aerodynamic Loads with Structural Response

NASA Technical Reports Server (NTRS)

Mangalam, Arun S.; Davis, Mark C.

2009-01-01

United States Air Force Research Laboratory (AFRL) ground tests at the NASA Transonic Dynamics Tunnel (TDT) and NASA flight tests provide a basis and methodology for in-flight characterization of the aeroelastic performance through the monitoring of the fluid-structure interaction using surface flow sensors. NASA NF-15B flight tests provided a unique opportunity to test the correlation of aerodynamic loads with sectional flow attachment/detachment points, also known as flow bifurcation points (FBPs), as observed in previous wind tunnel tests. The NF-15B tail was instrumented with hot-film sensors and strain gages for measuring root-bending strains. These data were gathered via selected sideslip maneuvers performed at level flight and subsonic speeds. The aerodynamic loads generated by the sideslip maneuver resulted in root-bending strains and hot-film sensor signals near the stagnation region that were highly correlated. For the TDT tests, a flexible wing section developed under the AFRL SensorCraft program was instrumented with strain gages, accelerometers, and hot-film sensors at multiple span stations. The TDT tests provided data showing a gradual phase change between the FBP and the structural mode occurred during a resonant condition as the wings structural modes were excited by the tunnel-generated gusts.

Orbital transfer vehicle 3000 LBF thrust chamber assembly hot fire test program

NASA Technical Reports Server (NTRS)

Schneider, Judy; Hayden, Warren R.

1988-01-01

The Aerojet Orbital Transfer Vehicle (OTV) Thrust Chamber Assembly (TCA) concept consists of a hydrogen cooled chamber, and annular injector, and an oxygen cooled centerbody. The hot fire testing of a heat sink version of the chamber with only the throat section using hydrogen cooling is documented. Hydraulic performance of the injector and cooled throat were verified by water flow testing prior to TCA assembly. The cooled throat was proof tested to 3000 psia to verify the integrity of the codeposited EF nickel-cobalt closeout. The first set of hot fire tests were conducted with a heat sink throat to obtain heat flux information. After demonstration of acceptable heat fluxes, the heat sink throat was replaced with the LH2 cooled throat section. Fourteen tests were conducted with a heat sink chamber and throat at chamber pressures of 85 to 359 psia. The injector face was modified at this time to add more face coolant flow. Ten tests were then conducted at chamber pressures of 197 to 620 psia. Actual heat fluxes at the higher chamber pressure range were 23 percent higher than the average of 10 Btu/in 2 predicted.

Completion of evaluation of manufacturing processes for B/Al composites containing 0.2mm diameter boron fibers

NASA Technical Reports Server (NTRS)

Moore, T. J.; Moorhead, P. E.

1980-01-01

Four fabricators produced a total of 54 B/1100 Al, B/6061 Al, and B/2024 Al panels for evaluation. The 8 ply unidirectional, 45 to 50 volume percent, panels were made using 0.20 mm diameter boron fibers which were obtained from a single supplier. Hot press consolidation was carried out in vacuum except for one set of dry woven tape panels which were hot pressed in air. A single testing contractor conducted nondestructive inspection, metallography, fractography and mechanical property tests. The mechanical property tests included 21 and 260 C tensile tests and 21 C shear tests. Panel quality, as measured by nondestructive evaluation, was generally good as were the 21 C tensile properties. The panels hot pressed in air delaminated in the shear tests. Shear strength values were lower in these panels. But tensile strengths were not affected by the delaminations because of the relation between the tensile loading direction and the delaminations. Composite tensile strength was found to be proportional to the volume percent boron and the aluminum matrix rather than to the tape used or fabrication technique. Suitability of these composites for 260 C service was confirmed by tensile tests.

Hot corrosion of the B2 nickel aluminides

NASA Technical Reports Server (NTRS)

Ellis, David L.

1993-01-01

The hot corrosion behavior of the B2 nickel aluminides was studied to determine the inherent hot corrosion resistance of the beta nickel aluminides and to develop a mechanism for the hot corrosion of the beta nickel aluminides. The effects of the prior processing of the material, small additions of zirconium, stoichiometry of the materials, and preoxidation of the samples were also examined. Additions of 2, 5, and 15 w/o chromium were used to determine the effect of chromium on the hot corrosion of the beta nickel aluminides and the minimum amount of chromium necessary for good hot corrosion resistance. The results indicate that the beta nickel aluminides have inferior inherent hot corrosion resistance despite their excellent oxidation resistance. Prior processing and zirconium additions had no discernible effect on the hot corrosion resistance of the alloys. Preoxidation extended the incubation period of the alloys only a few hours and was not considered to be an effective means of stopping hot corrosion. Stoichiometry was a major factor in determining the hot corrosion resistance of the alloys with the higher aluminum alloys having a definitely superior hot corrosion resistance. The addition of chromium to the alloys stopped the hot corrosion attack in the alloys tested. From a variety of experimental results, a complex hot corrosion mechanism was proposed. During the early stages of the hot corrosion of these alloys the corrosion is dominated by a local sulphidation/oxidation form of attack. During the intermediate stages of the hot corrosion, the aluminum depletion at the surface leads to a change in the oxidation mechanism from a protective external alumina layer to a mixed nickel-aluminum spinel and nickel oxide that can occur both externally and internally. The material undergoes extensive cracking during the later portions of the hot corrosion.

Irradiation Maintains Functional Components of Dry Hot Peppers (Capsicum annuum L.) under Ambient Storage

PubMed Central

Iqbal, Qumer; Amjad, Muhammad; Asi, Muhammad Rafique; Nawaz, Aamir; Khan, Samiya Mahmood; Ariño, Agustin; Ahmad, Tanveer

2016-01-01

Hot peppers used as natural flavoring and coloring agents are usually irradiated in prepacked form for decontamination. The effects of gamma radiation on the stability of functional components such as capsaicinoids and antioxidant compounds (carotenoids, ascorbic acid and total phenolics) were investigated in hot peppers (Capsicum annuum). Whole dried peppers packed in polyethylene bags were gamma irradiated at 0 (control), 2, 4, and 6 kGy and subsequently stored at 25 °C for 90 days. The irradiation dose did not substantially affect the initial contents of capsaicinoids, ascorbic acid and total phenolics, though the concentration of carotenoids declined by 8% from the control (76.9 mg/100 g) to 6 kGy radiation dose (70.7 mg/100 g). Similarly, during storage for 90 days at ambient temperature the concentrations of capsaicinoids and total phenolics remained fairly stable with mean percent reductions from 3.3% to 4.2%, while the levels of total carotenoids and ascorbic acid significantly (p < 0.05) declined by 12% and 14%, respectively. Overall, neither irradiation nor subsequent ambient storage could appreciably influence the contents of functional components in hot peppers. These results revealed that gamma irradiation up to 6 kGy can be safely used for decontamination to meet the needs for overseas markets without compromising product quality. PMID:28231158

Irradiation Maintains Functional Components of Dry Hot Peppers (Capsicum annuum L.) under Ambient Storage.

PubMed

Iqbal, Qumer; Amjad, Muhammad; Asi, Muhammad Rafique; Nawaz, Aamir; Khan, Samiya Mahmood; Ariño, Agustin; Ahmad, Tanveer

2016-09-12

Hot peppers used as natural flavoring and coloring agents are usually irradiated in prepacked form for decontamination. The effects of gamma radiation on the stability of functional components such as capsaicinoids and antioxidant compounds (carotenoids, ascorbic acid and total phenolics) were investigated in hot peppers ( Capsicum annuum ). Whole dried peppers packed in polyethylene bags were gamma irradiated at 0 (control), 2, 4, and 6 kGy and subsequently stored at 25 °C for 90 days. The irradiation dose did not substantially affect the initial contents of capsaicinoids, ascorbic acid and total phenolics, though the concentration of carotenoids declined by 8% from the control (76.9 mg/100 g) to 6 kGy radiation dose (70.7 mg/100 g). Similarly, during storage for 90 days at ambient temperature the concentrations of capsaicinoids and total phenolics remained fairly stable with mean percent reductions from 3.3% to 4.2%, while the levels of total carotenoids and ascorbic acid significantly ( p < 0.05) declined by 12% and 14%, respectively. Overall, neither irradiation nor subsequent ambient storage could appreciably influence the contents of functional components in hot peppers. These results revealed that gamma irradiation up to 6 kGy can be safely used for decontamination to meet the needs for overseas markets without compromising product quality.

Prediction of Hot Tearing Using a Dimensionless Niyama Criterion

NASA Astrophysics Data System (ADS)

Monroe, Charles; Beckermann, Christoph

2014-08-01

The dimensionless form of the well-known Niyama criterion is extended to include the effect of applied strain. Under applied tensile strain, the pressure drop in the mushy zone is enhanced and pores grow beyond typical shrinkage porosity without deformation. This porosity growth can be expected to align perpendicular to the applied strain and to contribute to hot tearing. A model to capture this coupled effect of solidification shrinkage and applied strain on the mushy zone is derived. The dimensionless Niyama criterion can be used to determine the critical liquid fraction value below which porosity forms. This critical value is a function of alloy properties, solidification conditions, and strain rate. Once a dimensionless Niyama criterion value is obtained from thermal and mechanical simulation results, the corresponding shrinkage and deformation pore volume fractions can be calculated. The novelty of the proposed method lies in using the critical liquid fraction at the critical pressure drop within the mushy zone to determine the onset of hot tearing. The magnitude of pore growth due to shrinkage and deformation is plotted as a function of the dimensionless Niyama criterion for an Al-Cu alloy as an example. Furthermore, a typical hot tear "lambda"-shaped curve showing deformation pore volume as a function of alloy content is produced for two Niyama criterion values.

Orbital Circularization of Hot and Cool Kepler Eclipsing Binaries

NASA Astrophysics Data System (ADS)

Van Eylen, Vincent; Winn, Joshua N.; Albrecht, Simon

2016-06-01

The rate of tidal circularization is predicted to be faster for relatively cool stars with convective outer layers, compared to hotter stars with radiative outer layers. Observing this effect is challenging because it requires large and well-characterized samples that include both hot and cool stars. Here we seek evidence of the predicted dependence of circularization upon stellar type, using a sample of 945 eclipsing binaries observed by Kepler. This sample complements earlier studies of this effect, which employed smaller samples of better-characterized stars. For each Kepler binary we measure e cos ω based on the relative timing of the primary and secondary eclipses. We examine the distribution of e cos ω as a function of period for binaries composed of hot stars, cool stars, and mixtures of the two types. At the shortest periods, hot-hot binaries are most likely to be eccentric; for periods shorter than four days, significant eccentricities occur frequently for hot-hot binaries, but not for hot-cool or cool-cool binaries. This is in qualitative agreement with theoretical expectations based on the slower dissipation rates of hot stars. However, the interpretation of our results is complicated by the largely unknown ages and evolutionary states of the stars in our sample.

Protein protein interactions: organization, cooperativity and mapping in a bottom-up Systems Biology approach

NASA Astrophysics Data System (ADS)

Keskin, Ozlem; Ma, Buyong; Rogale, Kristina; Gunasekaran, K.; Nussinov, Ruth

2005-06-01

Understanding and ultimately predicting protein associations is immensely important for functional genomics and drug design. Here, we propose that binding sites have preferred organizations. First, the hot spots cluster within densely packed 'hot regions'. Within these regions, they form networks of interactions. Thus, hot spots located within a hot region contribute cooperatively to the stability of the complex. However, the contributions of separate, independent hot regions are additive. Moreover, hot spots are often already pre-organized in the unbound (free) protein states. Describing a binding site through independent local hot regions has implications for binding site definition, design and parametrization for prediction. The compactness and cooperativity emphasize the similarity between binding and folding. This proposition is grounded in computation and experiment. It explains why summation of the interactions may over-estimate the stability of the complex. Furthermore, statistically, charge-charge coupling of the hot spots is disfavored. However, since within the highly packed regions the solvent is screened, the electrostatic contributions are strengthened. Thus, we propose a new description of protein binding sites: a site consists of (one or a few) self-contained cooperative regions. Since the residue hot spots are those conserved by evolution, proteins binding multiple partners at the same sites are expected to use all or some combination of these regions.

Effects of hot compression deformation temperature on the microstructure and properties of Al-Zr-La alloys

NASA Astrophysics Data System (ADS)

Yue, Xian-hua; Liu, Chun-fang; Liu, Hui-hua; Xiao, Su-fen; Tang, Zheng-hua; Tang, Tian

2018-02-01

The main goal of this study is to investigate the microstructure and electrical properties of Al-Zr-La alloys under different hot compression deformation temperatures. In particular, a Gleeble 3500 thermal simulator was used to carry out multi-pass hot compression tests. For five-pass hot compression deformation, the last-pass deformation temperatures were 240, 260, 300, 340, 380, and 420°C, respectively, where the first-pass deformation temperature was 460°C. The experimental results indicated that increasing the hot compression deformation temperature with each pass resulted in improved electrical conductivity of the alloy. Consequently, the flow stress was reduced after deformation of the samples subjected to the same number of passes. In addition, the dislocation density gradually decreased and the grain size increased after hot compression deformation. Furthermore, the dynamic recrystallization behavior was effectively suppressed during the hot compression process because spherical Al3Zr precipitates pinned the dislocation movement effectively and prevented grain boundary sliding.

Freezing Range, Melt Quality, and Hot Tearing in Al-Si Alloys

NASA Astrophysics Data System (ADS)

Uludağ, Muhammet; Çetin, Remzi; Dispinar, Derya

2018-02-01

In this study, three different aluminum-silicon alloys (A356, A413, and A380) that have different solidification morphology and solidification ranges were examined with an aim to evaluate the hot tearing susceptibility. T-shape mold and Constrained Rod Casting (CRC) mold were used for the characterization. Reduced Pressure Test (RPT) was used to quantify the casting quality by measuring bifilm index. It was found that bifilm index and solidification range have an important role on the hot tearing formation. As it is known, bifilms can cause porosity and in this case, it was shown that porosity formed by bifilms decreased hot tearing tendency. As the freezing range of alloy increases, bifilms find the time to unravel that reduces hot tearing. However, for eutectic alloy (A413), due to zero freezing range, regardless of bifilm content, hot tearing was never observed. A380.1 alloy had the highest tendency for hot tearing due to having the highest freezing range among the alloys investigated in this work.

Dynamic programming-based hot spot identification approach for pedestrian crashes.

PubMed

Medury, Aditya; Grembek, Offer

2016-08-01

Network screening techniques are widely used by state agencies to identify locations with high collision concentration, also referred to as hot spots. However, most of the research in this regard has focused on identifying highway segments that are of concern to automobile collisions. In comparison, pedestrian hot spot detection has typically focused on analyzing pedestrian crashes in specific locations, such as at/near intersections, mid-blocks, and/or other crossings, as opposed to long stretches of roadway. In this context, the efficiency of the some of the widely used network screening methods has not been tested. Hence, in order to address this issue, a dynamic programming-based hot spot identification approach is proposed which provides efficient hot spot definitions for pedestrian crashes. The proposed approach is compared with the sliding window method and an intersection buffer-based approach. The results reveal that the dynamic programming method generates more hot spots with a higher number of crashes, while providing small hot spot segment lengths. In comparison, the sliding window method is shown to suffer from shortcomings due to a first-come-first-serve approach vis-à-vis hot spot identification and a fixed hot spot window length assumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Creep of Sylramic-iBN Fiber Tows at Elevated Temperature in Air and in Silicic Acid-Saturated Steam

DTIC Science & Technology

2015-06-01

elements, R type control thermocouples and a 90-mm (3.5-in.) hot zone; reproduced from Armani [15] All tests employed an alumina susceptor (ceramic...Furnace Leff (500) = 39.9mm T = 500°C, Steam 45 4.1.2 Strain Measurement In this work tensile creep tests were performed using a dead-weight... strain and the strain rate of the specimen in the hot test section. These methods are briefly recapitulated here. Extension of the fiber tow

Effect of Temperature on the Fracture Toughness of Hot Isostatically Pressed 304L Stainless Steel

NASA Astrophysics Data System (ADS)

Cooper, A. J.; Brayshaw, W. J.; Sherry, A. H.

2018-03-01

Herein, we have performed J- Resistance multi-specimen fracture toughness testing of hot isostatically pressed (HIP'd) and forged 304L austenitic stainless steel, tested at elevated (300 °C) and cryogenic (- 140 °C) temperatures. The work highlights that although both materials fail in a pure ductile fashion, stainless steel manufactured by HIP displays a marked reduction in fracture toughness, defined using J 0.2BL, when compared to equivalently graded forged 304L, which is relatively constant across the tested temperature range.

Behavioral phenotyping of mice in pharmacological and toxicological research.

PubMed

Karl, Tim; Pabst, Reinhard; von Hörsten, Stephan

2003-07-01

The evaluation of behavioral effects is an important component for the in vivo screening of drugs or potentially toxic compounds in mice. Ideally, such screening should be composed of monitoring general health, sensory functions, and motor abilities, right before specific behavioral domains are tested. A rational strategy in the design and procedure of testing as well as an effective composition of different well-established and reproducible behavioral tests can minimize the risk of false positive and false negative results in drug screening. In the present review we describe such basic considerations in planning experiments, selecting strains of mice, and propose groups of behavioral tasks suitable for a reliable detection of differences in specific behavioral domains in mice. Screening of general health and neurophysiologic functions (reflexes, sensory abilities) and motor function (pole test, wire hang test, beam walking, rotarod, accelerod, and footprint) as well as specific hypothesis-guided testing in the behavioral domains of learning and memory (water maze, radial maze, conditioned fear, and avoidance tasks), emotionality (open field, hole board, elevated plus maze, and object exploration), nociception (tail flick, hot plate), psychiatric-like conditions (porsolt swim test, acoustic startle response, and prepulse inhibition), and aggression (isolation-induced aggression, spontaneous aggression, and territorial aggression) are described in further detail. This review is designed to describe a general approach, which increases reliability of behavioral screening. Furthermore, it provides an overview on a selection of specific procedures suitable for but not limited to behavioral screening in pharmacology and toxicology.

Subscale Carbon-Carbon Nozzle Extension Development and Hot Fire Testing in Support of Upper Stage Liquid Rocket Engines

NASA Technical Reports Server (NTRS)

Gradl, Paul; Valentine, Peter; Crisanti, Matthew; Greene, Sandy Elam

2016-01-01

Upper stage and in-space liquid rocket engines are optimized for performance through the use of high area ratio nozzles to fully expand combustion gases to low exit pressures increasing exhaust velocities. Due to the large size of such nozzles and the related engine performance requirements, carbon-carbon (C/C) composite nozzle extensions are being considered for use in order to reduce weight impacts. NASA and industry partner Carbon-Carbon Advanced Technologies (C-CAT) are working towards advancing the technology readiness level of large-scale, domestically-fabricated, C/C nozzle extensions. These C/C extensions have the ability to reduce the overall costs of extensions relative to heritage metallic and composite extensions and to decrease weight by 50%. Material process and coating developments have advanced over the last several years, but hot fire testing to fully evaluate C/C nozzle extensions in relevant environments has been very limited. NASA and C-CAT have designed, fabricated and hot fire tested multiple subscale nozzle extension test articles of various C/C material systems, with the goal of assessing and advancing the manufacturability of these domestically producible materials as well as characterizing their performance when subjected to the typical environments found in a variety of liquid rocket and scramjet engines. Testing at the MSFC Test Stand 115 evaluated heritage and state-of-the-art C/C materials and coatings, demonstrating the capabilities of the high temperature materials and their fabrication methods. This paper discusses the design and fabrication of the 1.2k-lbf sized carbon-carbon nozzle extensions, provides an overview of the test campaign, presents results of the hot fire testing, and discusses potential follow-on development work.

KFC2: a knowledge-based hot spot prediction method based on interface solvation, atomic density, and plasticity features.

PubMed

Zhu, Xiaolei; Mitchell, Julie C

2011-09-01

Hot spots constitute a small fraction of protein-protein interface residues, yet they account for a large fraction of the binding affinity. Based on our previous method (KFC), we present two new methods (KFC2a and KFC2b) that outperform other methods at hot spot prediction. A number of improvements were made in developing these new methods. First, we created a training data set that contained a similar number of hot spot and non-hot spot residues. In addition, we generated 47 different features, and different numbers of features were used to train the models to avoid over-fitting. Finally, two feature combinations were selected: One (used in KFC2a) is composed of eight features that are mainly related to solvent accessible surface area and local plasticity; the other (KFC2b) is composed of seven features, only two of which are identical to those used in KFC2a. The two models were built using support vector machines (SVM). The two KFC2 models were then tested on a mixed independent test set, and compared with other methods such as Robetta, FOLDEF, HotPoint, MINERVA, and KFC. KFC2a showed the highest predictive accuracy for hot spot residues (True Positive Rate: TPR = 0.85); however, the false positive rate was somewhat higher than for other models. KFC2b showed the best predictive accuracy for hot spot residues (True Positive Rate: TPR = 0.62) among all methods other than KFC2a, and the False Positive Rate (FPR = 0.15) was comparable with other highly predictive methods. Copyright © 2011 Wiley-Liss, Inc.

Qualification of a precise and easy-to-handle sweat casting imprint method for the prediction and quantification of anti-perspirant efficacy.

PubMed

Keyhani, R; Scheede, S; Thielecke, I; Wenck, H; Schmucker, R; Schreiner, V; Ennen, J; Herpens, A

2009-06-01

A time- and cost-effective sweat casting method using the forearm as test site to assess the efficacy of several anti-perspirant formulations with a low number of test subjects has been evaluated and qualified. The imprint sweat casting method is based on a 2-component silcone-imprint technique to measure the efficacy of more than eight products in parallel with the same test subject. In studies using aluminum chlorohydrate (ACH) formulations as test anti-perspirants, a clear-cut correlation could be demonstrated between sweat gland activities measured by the imprint method and gravimetric measurement of sweat gland activities. Concentration-dependent inhibition of sweat gland activity could be observed with the imprint technique up to an ACH concentration of 15%, and all formulations containing 2% ACH or above resulted in statistically significant reduction of sweat gland activity (P < 0.001) when compared with untreated control areas. Furthermore, the SDs of individual studies using the imprint technique were in a range of +/-20% of sweat gland activity, which can be regarded rather low for in vivo measurements of a complex process like sweat secretion. A group-wise comparison between the measurements of anti-perspirant activity as determined by the imprint protocol and the Food and Drug Administration (FDA) Guideline compliant gravimetric hot-room protocol revealed that the test results for anti-perspirant activity obtained with the imprint protocol are similar to those obtained with the hot-room protocol. Moreover, the data generated with the imprint protocol have a high predictive value for the outcome of a later guideline-compliant hot-room test. As the imprint casting method tends to be a little more sensitive for formulations with low anti-perspirant activity, and seems to be associated with less interassay variability than the standard gravimetric hot-room test, the imprint casting method may select products which later fail to pass the standard gravimetric hot-room test. Meanwhile the imprint sweat casting has proven to be a robust method useful to support efficacy-oriented product development. Therefore, in later stages of utilization it might even evolve into an efficient claim substantiation tool.

Cool Flame Quenching

NASA Technical Reports Server (NTRS)

Pearlman, Howard; Chapek, Richard

2001-01-01

Cool flame quenching distances are generally presumed to be larger than those associated with hot flames, because the quenching distance scales with the inverse of the flame propagation speed, and cool flame propagation speeds are often times slower than those associated with hot flames. To date, this presumption has never been put to a rigorous test, because unstirred, non-isothermal cool flame studies on Earth are complicated by natural convection. Moreover, the critical Peclet number (Pe) for quenching of cool flames has never been established and may not be the same as that associated with wall quenching due to conduction heat loss in hot flames, Pe approx. = 40-60. The objectives of this ground-based study are to: (1) better understand the role of conduction heat loss and species diffusion on cool flame quenching (i.e., Lewis number effects), (2) determine cool flame quenching distances (i.e, critical Peclet number, Pe) for different experimental parameters and vessel surface pretreatments, and (3) understand the mechanisms that govern the quenching distances in premixtures that support cool flames as well as hot flames induced by spark-ignition. Objective (3) poses a unique fire safety hazard if conditions exist where cool flame quenching distances are smaller than those associated with hot flames. For example, a significant, yet unexplored risk, can occur if a multi-stage ignition (a cool flame that transitions to a hot flame) occurs in a vessel size that is smaller than that associated with the hot quenching distance. To accomplish the above objectives, a variety of hydrocarbon-air mixtures will be tested in a static reactor at elevated temperature in the laboratory (1g). In addition, reactions with chemical induction times that are sufficiently short will be tested aboard NASA's KC-135 microgravity (mu-g) aircraft. The mu-g results will be compared to a numerical model that includes species diffusion, heat conduction, and a skeletal kinetic mechanism, following the work on diffusion-controlled cool flames by Fairlie et,al., 2000.

Performance of a hypersonic hot fuselage structure with a carbon dioxide frost projected, nonintegral cryogenic tank

NASA Technical Reports Server (NTRS)

Sharpe, E. L.; Jackson, L. R.

1975-01-01

A model which consisted of a hot structure and a nonintegral tank protected by a carbon dioxide frost thermal protection system was tested under the following conditions: (1) room temperature loading and (2) heating and loading corresponding to the Mach 8 flight of an air-breathing launch vehicle. In the simulated flight tests, liquid nitrogen inside the tank was withdrawn at the rate fuel would be consumed. Prior to each simulated flight test, carbon dioxide was cryodeposited in the insulation surrounding the tank; during the tests, subliming CO2 frost absorbed heat and provided a purge gas for the space between the tank and the structure. A method of flame spraying the joints between panels with a nickel-aluminum material was developed to prevent excessive leakage of the purge gas through the outer structure. The tests indicated that the hot structure (with a joint repaired by riveting), the nonintegral tank and suspension system, and the carbon dioxide frost thermal protection system provide a workable concept with predictable performance.

Long-term performance of a hot in-place recycling project final report.

DOT National Transportation Integrated Search

2016-08-01

This report documents the construction and long-term performance of a hot in-place recycled (HIPR) : project on SR 542. HIPR project selection, mix design, construction and testing are described. It was shown that : the HIPR process successfully reha...

Expanded clay hot mix study : final report: part I.

DOT National Transportation Integrated Search

1969-04-01

This is part I of a two part final report on expanded clay hot mix to: (1) evaluate the use of various expanded clay bituminous mixtures under high traffic counts, (2) accumulate through experience testing, suitable information on the physical proper...

Steel slag in hot mix asphalt concrete : final report

DOT National Transportation Integrated Search

2000-04-01

In September 1994, steel slag test and control sections were constructed in Oregon to evaluate the use of steel slag in hot mix asphalt concrete (HMAC). This report covers the construction and five-year performance of a pavement constructed with 30% ...

POTENTIAL AIR TOXICS HOT SPOTS IN TRUCK TERMINALS AND CABS

EPA Science Inventory

All three types of testing sites — upwind and downwind traffic — met the established definition for a hot spot by having periods with concentrations of pollutants that exceeded the EPA’s screening values. Most frequently, the pollutants with concentrations...

Vacuum-Induction, Vacuum-Arc, and Air-Induction Melting of a Complex Heat-Resistant Alloy

NASA Technical Reports Server (NTRS)

Decker, R. F.; Rowe, John P.; Freeman, J. W.

1959-01-01

The relative hot-workability and creep-rupture properties at 1600 F of a complex 55Ni-20Cr-15Co-4Mo-3Ti-3Al alloy were evaluated for vacuum-induction, vacuum-arc, and air-induction melting. A limited study of the role of oxygen and nitrogen and the structural effects in the alloy associated with the melting process was carried out. The results showed that the level of boron and/or zirconium was far more influential on properties than the melting method. Vacuum melting did reduce corner cracking and improve surface during hot-rolling. It also resulted in more uniform properties within heats. The creep-rupture properties were slightly superior in vacuum heats at low boron plus zirconium or in heats with zirconium. There was little advantage at high boron levels and air heats were superior at high levels of boron plus zirconium. Vacuum heats also had fewer oxide and carbonitride inclusions although this was a function of the opportunity for separation of the inclusions from high oxygen plus nitrogen heats. The removal of phosphorous by vacuum melting was not found to be related to properties. Oxygen plus nitrogen appeared to increase ductility in creep-rupture tests suggesting that vacuum melting removes unidentified elements detrimental to ductility. Oxides and carbonitrides in themselves did not initiate microcracks. Carbonitrides in the grain boundaries of air heats did initiate microcracks. The role of microcracking from this source and as a function of oxygen and nitrogen content was not clear. Oxygen and nitrogen did intensify corner cracking during hot-rolling but were not responsible for poor surface which resulted from rolling heats melted in air.

HOT CELL BUILDING, TRA632. FLOOR PLAN OF EXPANSION SHOWS LOCATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. FLOOR PLAN OF EXPANSION SHOWS LOCATION OF NEW CELLS, "HEAVY" CELL AT WEST END, "LIGHT" CELLS AT EAST. MOCK-UP AND STORAGE AREAS IN SOUTH HALF OF FLOOR. H.K. FERGUSON 895-MTR-ETR-632-A1, 12/1958. INL INDEX NO. 531-0632-00-279-101924, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Hot Corrosion Test Facility at the NASA Lewis Special Projects Laboratory

NASA Technical Reports Server (NTRS)

Robinson, Raymond C.; Cuy, Michael D.

1994-01-01

The Hot Corrosion Test Facility (HCTF) at the NASA Lewis Special Projects Laboratory (SPL) is a high-velocity, pressurized burner rig currently used to evaluate the environmental durability of advanced ceramic materials such as SiC and Si3N4. The HCTF uses laboratory service air which is preheated, mixed with jet fuel, and ignited to simulate the conditions of a gas turbine engine. Air, fuel, and water systems are computer-controlled to maintain test conditions which include maximum air flows of 250 kg/hr (550 lbm/hr), pressures of 100-600 kPa (1-6 atm), and gas temperatures exceeding 1500 C (2732 F). The HCTF provides a relatively inexpensive, yet sophisticated means for researchers to study the high-temperature oxidation of advanced materials, and the injection of a salt solution provides the added capability of conducting hot corrosion studies.

Effluent characterization from a conical pressurized fluid bed

NASA Technical Reports Server (NTRS)

Priem, R. J.; Rollbuhler, R. J.; Patch, R. W.

1977-01-01

To obtain useable corrosion and erosion results it was necessary to have data with several levels of particulate matter in the hot gases. One level of particulate loading was as low as possible so that ideally no erosion and only corrosion occurred. A conical fluidized bed was used to obtain some degree of filtration through the top of the bed which would not be highly fluidized. This would minimize the filtration required for the hot gases or conversely the amount of particulate matter in the hot gases after a given level of filtration by cyclones and/or filters. The data obtained during testing characterized the effluent from the bed at different test conditions. A range of bed heights, coal flows, air flows, limestone flows, and pressure are represented. These tests were made to determine the best operating conditions prior to using the bed to determine erosion and corrosion rates of typical turbine blade materials.

Construction of a High Temperature Teg Measurement System for the Evaluation of Thermoelectric Oxide Modules

NASA Astrophysics Data System (ADS)

Populoh, S.; Trottmann, M.; Brunko, O. C.; Thiel, P.; Weidenkaff, A.

2013-08-01

A dedicated test stand was developed and built to characterize the efficiency, power output and open circuit voltage of various thermoelectric generators (TEGs) based on tellurides, heusler compounds and thermoelectric oxides. The test stand allows measurements of TEGs of sizes up to 4 cm × 4 cm at hot side temperatures up to 1150 K in different atmospheres. Special care was taken about the heat flux measurement by precise measurement of the temperature distribution within the reference block. In order to demonstrate the functionality of the test stand thermoelectric oxide modules (TOM) were built from n-type perovskite-type manganates and p-type cuprates. The modules were tested regarding their stability, maximum power output and efficiency at temperatures up to 1100 K. The TOMs withstand large temperature gradients and operated in ambient air yielding high power densities.

[A randomized controlled trial: acclimatization training on the prevention of motion sickness in hot-humid environment].

PubMed

Zhang, Lei; Mao, Jun-Feng; Wu, Xiao-Nong; Bao, Ying-Chun

2014-05-01

Incidence and severity of motion sickness (MS) in hot-humid environment are extremely high. We tried to know the effect of two-stage training for reducing incidence and severity of ms. Sixty male subjects were divided into experimental group and control group randomly. Subjects in experimental group received: (2) adaptation training including sitting, walking and running in hot lab. After adaptation confirmation based on subjective feeling, rectal temperature, heart rate, blood Pressure, sweat rates and sweat salt concentration, we tested both groups by Coriolis acceleration revolving chair test and recorded Graybiel's score and grading of severity to evaluate whether adaptation training was useful; (2) Anti-dizzy training 3m later of deacclimatization contained revolving chair training for 10 times. Then we did the same test as mentioned above to evaluate effect of anti-dizzy training. RESULST: Graybiel' s score and grading of severity had no difference between two groups through acclimatization training (P > 0.05). While they had difference through anti-dizzy training (P < 0.01). Adaptation training seems useless for reducing incidence and severity of MS in hot-humid environment, but anti-dizzy training is useful.

Creep fatigue life prediction for engine hot section materials (isotropic)

NASA Technical Reports Server (NTRS)

Moreno, V.

1983-01-01

The Hot Section Technology (HOST) program, creep fatigue life prediction for engine hot section materials (isotropic), is reviewed. The program is aimed at improving the high temperature crack initiation life prediction technology for gas turbine hot section components. Significant results include: (1) cast B1900 and wrought IN 718 selected as the base and alternative materials respectively; (2) fatigue test specimens indicated that measurable surface cracks appear early in the specimen lives, i.e., 15% of total life at 871 C and 50% of life at 538 c; (3) observed crack initiation sites are all surface initiated and are associated with either grain boundary carbides or local porosity, transgrannular cracking is observed at the initiation site for all conditions tested; and (4) an initial evaluation of two life prediction models, representative of macroscopic (Coffin-Mason) and more microscopic (damage rate) approaches, was conducted using limited data generated at 871 C and 538 C. It is found that the microscopic approach provides a more accurate regression of the data used to determine crack initiation model constants, but overpredicts the effect of strain rate on crack initiation life for the conditions tested.

THE ORIGIN OF THE HOT GAS IN THE GALACTIC HALO: TESTING GALACTIC FOUNTAIN MODELS' X-RAY EMISSION

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

Henley, David B.; Shelton, Robin L.; Kwak, Kyujin

2015-02-20

We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements of the emission from the Milky Way's hot halo. These measurements are from 110 sight lines, spanning the full range of Galactic longitudes. We find that a magnetohydrodynamical simulation of a supernova-driven interstellar medium, which features a flow of hot gas from the disk to the halo, reproduces the temperature but significantly underpredicts the 0.5-2.0 keV surface brightness of the halo (by two orders of magnitude, if we compare the median predicted and observed values). This is true for versions of the model with and without anmore » interstellar magnetic field. We consider different reasons for the discrepancy between the model predictions and the observations. We find that taking into account overionization in cooled halo plasma, which could in principle boost the predicted X-ray emission, is unlikely in practice to bring the predictions in line with the observations. We also find that including thermal conduction, which would tend to increase the surface brightnesses of interfaces between hot and cold gas, would not overcome the surface brightness shortfall. However, charge exchange emission from such interfaces, not included in the current model, may be significant. The faintness of the model may also be due to the lack of cosmic ray driving, meaning that the model may underestimate the amount of material transported from the disk to the halo. In addition, an extended hot halo of accreted material may be important, by supplying hot electrons that could boost the emission of the material driven out from the disk. Additional model predictions are needed to test the relative importance of these processes in explaining the observed halo emission.« less

The Origin of the Hot Gas in the Galactic Halo: Testing Galactic Fountain Models' X-Ray Emission

NASA Astrophysics Data System (ADS)

Henley, David B.; Shelton, Robin L.; Kwak, Kyujin; Hill, Alex S.; Mac Low, Mordecai-Mark

2015-02-01

We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements of the emission from the Milky Way's hot halo. These measurements are from 110 sight lines, spanning the full range of Galactic longitudes. We find that a magnetohydrodynamical simulation of a supernova-driven interstellar medium, which features a flow of hot gas from the disk to the halo, reproduces the temperature but significantly underpredicts the 0.5-2.0 keV surface brightness of the halo (by two orders of magnitude, if we compare the median predicted and observed values). This is true for versions of the model with and without an interstellar magnetic field. We consider different reasons for the discrepancy between the model predictions and the observations. We find that taking into account overionization in cooled halo plasma, which could in principle boost the predicted X-ray emission, is unlikely in practice to bring the predictions in line with the observations. We also find that including thermal conduction, which would tend to increase the surface brightnesses of interfaces between hot and cold gas, would not overcome the surface brightness shortfall. However, charge exchange emission from such interfaces, not included in the current model, may be significant. The faintness of the model may also be due to the lack of cosmic ray driving, meaning that the model may underestimate the amount of material transported from the disk to the halo. In addition, an extended hot halo of accreted material may be important, by supplying hot electrons that could boost the emission of the material driven out from the disk. Additional model predictions are needed to test the relative importance of these processes in explaining the observed halo emission.

Persistence of forage fish ‘hot spots’ and its association with foraging Steller sea lions (Eumetopias jubatus) in southeast Alaska

NASA Astrophysics Data System (ADS)

Gende, Scott M.; Sigler, Michael F.

2006-02-01

Whereas primary and secondary productivity at oceanic 'hotspots' may be a function of upwelling and temperature fronts, the aggregation of higher-order vertebrates is a function of their ability to search for and locate these areas. Thus, understanding how predators aggregate at these productive foraging areas is germane to the study of oceanic hot spots. We examined the spatial distribution of forage fish in southeast Alaska for three years to better understand Steller sea lion ( Eumetopias jubatus) aggregations and foraging behavior. Energy densities (millions KJ/km 2) of forage fish were orders of magnitude greater during the winter months (November-February), due to the presence of schools of overwintering Pacific herring ( Clupea pallasi). Within the winter months, herring consistently aggregated at a few areas, and these areas persisted throughout the season and among years. Thus, our study area was characterized by seasonally variable, highly abundant but highly patchily distributed forage fish hot spots. More importantly, the persistence of these forage fish hot spots was an important characteristic in determining whether foraging sea lions utilized them. Over 40% of the variation in the distribution of sea lions on our surveys was explained by the persistence of forage fish hot spots. Using a simple spatial model, we demonstrate that when the density of these hot spots is low, effort necessary to locate these spots is minimized when those spots persist through time. In contrast, under similar prey densities but lower persistence, effort increases dramatically. Thus an important characteristic of pelagic hot spots is their persistence, allowing predators to predict their locations and concentrate search efforts accordingly.

Molecular interfaces for plasmonic hot electron photovoltaics

NASA Astrophysics Data System (ADS)

Pelayo García de Arquer, F.; Mihi, Agustín; Konstantatos, Gerasimos

2015-01-01

The use of self-assembled monolayers (SAMs) to improve and tailor the photovoltaic performance of plasmonic hot-electron Schottky solar cells is presented. SAMs allow the simultaneous control of open-circuit voltage, hot-electron injection and short-circuit current. To that end, a plurality of molecule structural parameters can be adjusted: SAM molecule's length can be adjusted to control plasmonic hot electron injection. Modifying SAMs dipole moment allows for a precise tuning of the open-circuit voltage. The functionalization of the SAM can also be selected to modify short-circuit current. This allows the simultaneous achievement of high open-circuit voltages (0.56 V) and fill-factors (0.58), IPCE above 5% at the plasmon resonance and maximum power-conversion efficiencies of 0.11%, record for this class of devices.The use of self-assembled monolayers (SAMs) to improve and tailor the photovoltaic performance of plasmonic hot-electron Schottky solar cells is presented. SAMs allow the simultaneous control of open-circuit voltage, hot-electron injection and short-circuit current. To that end, a plurality of molecule structural parameters can be adjusted: SAM molecule's length can be adjusted to control plasmonic hot electron injection. Modifying SAMs dipole moment allows for a precise tuning of the open-circuit voltage. The functionalization of the SAM can also be selected to modify short-circuit current. This allows the simultaneous achievement of high open-circuit voltages (0.56 V) and fill-factors (0.58), IPCE above 5% at the plasmon resonance and maximum power-conversion efficiencies of 0.11%, record for this class of devices. Electronic supplementary information (ESI) available: Contact-potential differentiometry measurements, FTIR characterization, performance statistics and gold devices. See DOI: 10.1039/c4nr06356b

Comparative study of hamstring and quadriceps strengthening treatments in the management of knee osteoarthritis.

PubMed

Al-Johani, Ahmed H; Kachanathu, Shaji John; Ramadan Hafez, Ashraf; Al-Ahaideb, Abdulaziz; Algarni, Abdulrahman D; Meshari Alroumi, Abdulmohesn; Alanezi, Aqeel M

2014-06-01

[Purpose] Osteoarthritis (OA) of the knee is the most common form of joint disease. It is one of the major causes of impaired function that reduces quality of life (QOL) worldwide. The purpose of this study was to compare exercise treatments for hamstring and quadriceps strength in the management of knee osteoarthritis. [Subjects and Methods] Forty patients with OA knee, aged 50-65 years were divided into 2 groups. The first group (57.65±4.78 years) received hot packs and performed strengthening exercises for the quadriceps and hamstring, and stretching exercises for the hamstring. The second group (58.15±5.11 years) received hot packs and performed strengthening exercises for only the quadriceps, and stretching exercise for the hamstring. Outcome measures were the WOMAC (Western Ontario and McMaster Universities OA index questionnaire), Visual Analogue Scale (VAS) assessment of pain, the Fifty-Foot Walk Test (FWS), and Handheld dynamometry. [Results] There was a significant difference between the groups. The first group showed a more significant result than the second group. [Conclusion] Strengthening of the hamstrings in addition to strengthening of the quadriceps was shown to be beneficial for improving subjective knee pain, range of motion and decreasing the limitation of functional performance of patients with knee osteoarthritis.

Casein Kinase II Regulation of the Hot1 Transcription Factor Promotes Stochastic Gene Expression*

PubMed Central

Burns, Laura T.; Wente, Susan R.

2014-01-01

In Saccharomyces cerevisiae, Hog1 MAPK is activated and induces a transcriptional program in response to hyperosmotic stress. Several Hog1-responsive genes exhibit stochastic transcription, resulting in cell-to-cell variability in mRNA and protein levels. However, the mechanisms governing stochastic gene activity are not fully defined. Here we uncover a novel role for casein kinase II (CK2) in the cellular response to hyperosmotic stress. CK2 interacts with and phosphorylates the Hot1 transcription factor; however, Hot1 phosphorylation is not sufficient for controlling the stochastic response. The CK2 protein itself is required to negatively regulate mRNA expression of Hot1-responsive genes and Hot1 enrichment at target promoters. Single-cell gene expression analysis reveals altered activation of Hot1-targeted STL1 in ck2 mutants, resulting in a bimodal to unimodal shift in expression. Together, this work reveals a novel CK2 function during the hyperosmotic stress response that promotes cell-to-cell variability in gene expression. PMID:24817120

Thermal Infrared Hot Spot and Dependence on Canopy Geometry

NASA Technical Reports Server (NTRS)

Smith, James A.; Ballard, Jerrell R., Jr.; Smith, David E. (Technical Monitor)

2001-01-01

We perform theoretical calculations of the canopy thermal infrared (TIR) hot spot using a first principles 3-D model described earlier. Various theoretical canopies of varying leaf size and for differing canopy height are used to illustrate the magnitude of the TIR effect. Our results are similar to predicted behavior in the reflective hot spot as a function of canopy geometry and comparable to TIR measurements from the literature and our own simple ground experiments. We apply the MODTRAN atmospheric code to estimate the at-sensor variation in brightness temperature with view direction in the solar principal plane. For simple homogeneous canopies, we predict canopy thermal infrared hot spot variations of 2 degrees C at the surface with respect to nadir viewing. Dependence on leaf size is weak as long as the ratio of leaf size to canopy height is maintained. However, the angular width of the hot spot increases as the ratio of leaf diameter to canopy height increases. Atmospheric effects minimize but do not eliminate the TIR hot spot at satellite altitudes.

40 CFR 93.109 - Criteria and procedures for determining conformity of transportation plans, programs, and...

Code of Federal Regulations, 2011 CFR

2011-07-01

...) through (k) of this section explain when the budget, interim emissions, and hot-spot tests are required... § 93.115 Project from a conforming plan and TIP § 93.116 CO, PM10, and PM2.5 hot-spots. § 93.117 PM10... Currently conforming plan and TIP § 93.116 CO, PM10, and PM2.5 hot-spots. § 93.117 PM10 and PM2.5 control...

40 CFR 93.109 - Criteria and procedures for determining conformity of transportation plans, programs, and...

Code of Federal Regulations, 2010 CFR

2010-07-01

...) through (k) of this section explain when the budget, interim emissions, and hot-spot tests are required... § 93.115 Project from a conforming plan and TIP § 93.116 CO, PM10, and PM2.5 hot-spots. § 93.117 PM10... Currently conforming plan and TIP § 93.116 CO, PM10, and PM2.5 hot-spots. § 93.117 PM10 and PM2.5 control...

A&M. Hot cell addition (TAN633). Floor plan, elevations. Arrangement of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Hot cell addition (TAN-633). Floor plan, elevations. Arrangement of monorail along corridor, four hot cells, plug access openings, viewing windows, photo darkroom. Ralph M. Parsons 1229-13-ANP/GE-3-633-A-1. Date: December 1956 as redrawn in August 1998. Approved by INEEL Classification Office for public release. INEEL index code no. 034-0633-00-693-107315 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Hot air balloons fill gap in atmospheric and sensing platforms

NASA Astrophysics Data System (ADS)

Watson, Steven M.; Price, Russ

Eric Edgerton was having a problem he could not solve: how to noninvasively collect in situ incinerator plume data. So he called in the Air Force and learned about its Atmospheric and Sensor Test Platform program; its platform is a manned hot air balloon. Many investigators are discovering the advantages of hot air balloons as stable, inexpensive platforms for performing in situ atmospheric measurements. Some are also using remote sensing capabilities on the balloon platforms.

Oxidation of boron nitride in an arc heated jet.

NASA Technical Reports Server (NTRS)

Buckley, J. D.

1971-01-01

Two grades of hot pressed boron nitride and a boron nitride composite were subjected to oxidation tests in a 2.5 megawatt atmospheric arc jet. The results showed that fabrication and/or composition influenced thermal shock and oxidation resistance. Changes in surface structure and recession due to oxidation suggest correlation with specimen composition. The boron nitride composite reacted with the oxygen in the hot subsonic airstream to produce a glassy coating on the hot face surface.

Brain blood flow and cardiovascular responses to hot flashes in postmenopausal women

PubMed Central

Lucas, Rebekah A. I.; Ganio, Matthew S.; Pearson, James; Crandall, Craig G.

2012-01-01

Objective This study tested two related hypotheses: 1) that brain blood flow is reduced during the postmenopausal hot flash; and, 2) the magnitude of this reduction in brain blood flow is greater during hot flashes where blood pressure is reduced. Methods Eleven healthy, normotensive, postmenopausal women rested in a temperature-controlled laboratory (~25°C) for approximately 120 minutes while waiting for a hot flash to occur. The onset of a hot flash was objectively identified by an abrupt increase in sternal sweat rate (capacitance hygrometry). Middle cerebral artery blood velocity (MCAv, transcranial Doppler) and mean arterial pressure (Finometer®) were measured continuously. Each hot flash was divided into 8 equal segments and the segment with the largest reduction in MCAv and mean arterial pressure identified for each hot flash. Results Twenty-five hot flashes occurred during the experimental sessions (lasting 6.2 ± 2.8 min, 3 ± 1 hot flashes per participant). Seventy-six percent of hot flashes were accompanied by a clear reduction (greater than 5%) in brain blood flow. For all hot flashes, the average maximum decrease in MCAv was 12 ± 9% (7 ± 6 cm.s−1). This value did not correlate with corresponding changes in mean arterial pressure (R=0.36). Conclusion These findings demonstrate that hot flashes are often accompanied by clear reductions in brain blood flow that do not correspond with acute reductions in mean arterial blood pressure. PMID:23435027

Are menopausal hot flashes an evolutionary byproduct of postpartum warming?

PubMed

Sievert, Lynnette Leidy; Masley, Allison

2015-04-01

Hot flashes are commonly associated with menopause, and some researchers have questioned whether the widespread phenomenon may somehow be adaptive. It has been hypothesized that hot flashes were selected to occur during the hypoestrogenic postpartum period as a mechanism to warm infants. The purpose of this study was to test whether postpartum hot flashes are similar to hot flashes associated with menopause and whether postpartum hot flashes are concordant with breast-feeding episodes. Women who gave birth within the past year (n = 20) and a comparison group of women who had not given birth in the past 2 years (n = 14) participated in interviews and anthropometric measures. All wore ambulatory skin conductance monitors for a mean of 6.5 hours during afternoons and early evenings. New mothers also recorded breast-feeding episodes. Objectively measured and subjectively reported hot flashes were compared between groups and in relation to breast-feeding and other variables. Age of infants ranged from 4 days to 11 months. New mothers were more likely to report feeling warmer than the comparison group (100% vs 7%) but were not significantly more likely to demonstrate hot flashes (35% vs 50%) or to report hot flashes (30% vs 21%) during the study period. Of 75 breast-feeding episodes, only 4% were concurrent with an objective hot flash, and only 9% were concurrent with a subjective hot flash. This study does not support the hypothesis that menopausal-like hot flashes evolved to warm infants during the postpartum period.

Hot Deformation Behavior and Pulse Current Auxiliary Isothermal Forging of Hot Pressing Sintering TiAl Based Alloys

PubMed Central

Shi, Chengcheng; Jiang, Shaosong; Zhang, Kaifeng

2017-01-01

This paper focuses on the fabrication of as-forged Ti46.5Al2Cr1.8Nb-(W, B) alloy via pulse current auxiliary isothermal forging (PCIF). The starting material composed of near gamma (NG) microstructure was fabricated by adopting pre-alloyed powders via hot pressing sintering (HPS) at 1300 °C. Isothermal compression tests were conducted at a strain rate range of 0.001–0.1 s−1 and a temperature range of 1125–1275 °C to establish the constitutive model and processing map. The optimal hot deformation parameters were successfully determined (in a strain rate range of 10−3–2.5 × 10−3 s−1 and temperature range of 1130–1180 °C) based on the hot processing map and microstructure observation. Accordingly, an as-forged TiAl based alloy without cracks was successfully fabricated by PCIF processing at 1175 °C with a nominal strain rate of 10−3 s−1. Microstructure observation indicated that complete dynamic recrystallization (DRX) and phase transformation of γ→α2 occurred during the PCIF process. The elongation of as-forged alloy was 136%, possessing a good secondary hot workability, while the sintered alloy was only 66% when tested at 900 °C with a strain rate of 2 × 10−4 s−1. PMID:29258198

Hot Deformation Behavior and Pulse Current Auxiliary Isothermal Forging of Hot Pressing Sintering TiAl Based Alloys.

PubMed

Shi, Chengcheng; Jiang, Shaosong; Zhang, Kaifeng

2017-12-16

This paper focuses on the fabrication of as-forged Ti46.5Al2Cr1.8Nb-(W, B) alloy via pulse current auxiliary isothermal forging (PCIF). The starting material composed of near gamma (NG) microstructure was fabricated by adopting pre-alloyed powders via hot pressing sintering (HPS) at 1300 °C. Isothermal compression tests were conducted at a strain rate range of 0.001-0.1 s -1 and a temperature range of 1125-1275 °C to establish the constitutive model and processing map. The optimal hot deformation parameters were successfully determined (in a strain rate range of 10 -3 -2.5 × 10 -3 s -1 and temperature range of 1130-1180 °C) based on the hot processing map and microstructure observation. Accordingly, an as-forged TiAl based alloy without cracks was successfully fabricated by PCIF processing at 1175 °C with a nominal strain rate of 10 -3 s -1 . Microstructure observation indicated that complete dynamic recrystallization (DRX) and phase transformation of γ→α₂ occurred during the PCIF process. The elongation of as-forged alloy was 136%, possessing a good secondary hot workability, while the sintered alloy was only 66% when tested at 900 °C with a strain rate of 2 × 10 -4 s -1 .

Chemical processes involved in the initiation of hot corrosion of B-1900 and NASA-TRW VIA

NASA Technical Reports Server (NTRS)

Fryburg, G. C.; Kohl, F. J.; Stearns, C. A.

1979-01-01

Sodium sulfate induced hot corrosion of B-1900 and NASA-TRW VIA at 900 C was studied with special emphasis on the chemical reactions occurring during and immediately after the induction period. Thermogravimetric tests were run for set periods of time after which the samples were washed with water and water soluable metal salts and/or residual sulfates were analyzed chemically. Element distributions within the oxide layer were obtained from electron microprobe X-ray micrographs. A third set of samples were subjected to surface analysis by X-ray photoelectron spectroscopy. Evolution of SO2 was monitored throughout many of the hot corrosion tests. Results are interpreted in terms of acid-base fluxing mechanisms.

Ice-cooled vest for work in hot mines

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

Not Available

1979-04-01

A specially designed ice-cooled vest is worn while working in hot environments where cooling the mine air is not possible. The vest holds a total of 44 individual ice cells in packets that are firmly held near the wearer's skin. These ice cells remove heat from the wearer, reducing heat stress and increasing comfort. Laboratory testing at Pennsylvania State University showed that the cooling vest greatly prolongs the time that men can work in hot environments. Rescue men, wearing breathing apparatus and working in very humid air at 96/sup 0/F were able to work about 40% longer when using themore » vest. The vest has also been tested for several months in a chemical plant.« less

RS-88 Pad Abort Demonstrator Thrust Chamber Assembly Testing at NASA Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Farr, Rebecca A.; Sanders, Timothy M.

1990-01-01

This paper documents the effort conducted to collect hot-tire dynamic and acoustics environments data during 50,000-lb thrust lox-ethanol hot-fire rocket testing at NASA Marshall Space Flight Center (MSFC) in November-December 2003. This test program was conducted during development testing of the Boeing Rocketdyne RS-88 development engine thrust chamber assembly (TCA) in support of the Orbital Space Plane (OSP) Crew Escape System Propulsion (CESP) Program Pad Abort Demonstrator (PAD). In addition to numerous internal TCA and nozzle measurements, induced acoustics environments data were also collected. Provided here is an overview of test parameters, a discussion of the measurements, test facility systems and test operations, and a quality assessment of the data collected during this test program.

Deletion of exons 3-9 encompassing a mutational hot spot in the DMD gene presents an asymptomatic phenotype, indicating a target region for multiexon skipping therapy.

PubMed

Nakamura, Akinori; Fueki, Noboru; Shiba, Naoko; Motoki, Hirohiko; Miyazaki, Daigo; Nishizawa, Hitomi; Echigoya, Yusuke; Yokota, Toshifumi; Aoki, Yoshitsugu; Takeda, Shin'ichi

2016-07-01

Few cases of dystrophinopathy show an asymptomatic phenotype with mutations in the 5' (exons 3-7) hot spot in the Duchenne muscular dystrophy (DMD) gene. Our patient showed increased serum creatine kinase levels at 12 years of age. A muscle biopsy at 15 years of age led to a diagnosis of Becker muscular dystrophy. The patient showed a slight decrease in cardiac function at the age of 21 years and was administered a β-blocker, but there was no muscle involvement even at the age of 27 years. A deletion of exons 3-9 encompassing a mutational hot spot in the DMD gene was detected, and dystrophin protein expression was ∼15% that of control level. We propose that in-frame deletion of exons 3-9 may produce a functional protein, and that multiexon skipping therapy targeting these exons may be feasible for severe dystrophic patients with a mutation in the 5' hot spot of the DMD gene.

Durability Testing of Commercial Ceramic Materials

NASA Technical Reports Server (NTRS)

Schienle, J. L.

1996-01-01

Technical efforts by AlliedSignal Engines in DOE/NASA-funded project from February, 1978 through December, 1995 are reported in the fields ceramic materials for gas turbine engines and cyclic thermal durability testing. A total of 29 materials were evaluated in 40 cyclic oxidation exposure durability tests. Ceramic test bars were cyclically thermally exposed to a hot combustion environment at temperatures up to 1371 C (2500 F) for periods of up to 3500 hours, simulating conditions typically encountered by hot flowpath components in an automotive gas turbine engine. Before and after exposure, quarter-point flexure strength tests were performed on the specimens, and fractography examinations including scanning electron microscopy (SEM) were performed to determine failure origins.

Comparative performance of rubber modified hot mix asphalt under ALF loading.

DOT National Transportation Integrated Search

2003-08-01

Experiment 2 at the Louisiana ALF site involved determining the engineering benefits of using powdered rubber (PRM) in hot mix asphalt mixes. Three full scale test sections were constructed and subjected to increasing loads from the ALF. Lane 2-1 inc...