A fusible heat sink concept for extravehicular activity /EVA/ thermal control

NASA Technical Reports Server (NTRS)

Roebelen, G. J., Jr.

1976-01-01

This paper describes the preliminary design and analysis of a heat sink system, utilizing a phase change slurry material, to be used for astronaut and equipment cooling during manned space missions. During normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a regenerable fusible heat sink. Recharge is accomplished by disconnecting the heat sink from the liquid cooling garment and placing it in an onboard freezer for simultaneous slurry refreeze and power supply recharge.

Liquid-Cooled Garment

NASA Technical Reports Server (NTRS)

1977-01-01

A liquid-cooled bra, offshoot of Apollo moon suit technology, aids the cancer-detection technique known as infrared thermography. Water flowing through tubes in the bra cools the skin surface to improve resolution of thermograph image.

Flexible Fabrics with High Thermal Conductivity for Advanced Spacesuits

NASA Technical Reports Server (NTRS)

Trevino, Luis A.; Bue, Grant; Orndoff, Evelyne; Kesterson, Matt; Connel, John W.; Smith, Joseph G., Jr.; Southward, Robin E.; Working, Dennis; Watson, Kent A.; Delozier, Donovan M.

2006-01-01

This paper describes the effort and accomplishments for developing flexible fabrics with high thermal conductivity (FFHTC) for spacesuits to improve thermal performance, lower weight and reduce complexity. Commercial and additional space exploration applications that require substantial performance enhancements in removal and transport of heat away from equipment as well as from the human body can benefit from this technology. Improvements in thermal conductivity were achieved through the use of modified polymers containing thermally conductive additives. The objective of the FFHTC effort is to significantly improve the thermal conductivity of the liquid cooled ventilation garment by improving the thermal conductivity of the subcomponents (i.e., fabric and plastic tubes). This paper presents the initial system modeling studies, including a detailed liquid cooling garment model incorporated into the Wissler human thermal regulatory model, to quantify the necessary improvements in thermal conductivity and garment geometries needed to affect system performance. In addition, preliminary results of thermal conductivity improvements of the polymer components of the liquid cooled ventilation garment are presented. By improving thermal garment performance, major technology drivers will be addressed for lightweight, high thermal conductivity, flexible materials for spacesuits that are strategic technical challenges of the Exploration

Liquid Cooling/Warming Garment

NASA Technical Reports Server (NTRS)

Koscheyev, Victor S.; Leon, Gloria R.; Dancisak, Michael J.

2010-01-01

The NASA liquid cooling/ventilating garment (LCVG) currently in use was developed over 40 years ago. With the commencement of a greater number of extra-vehicular activity (EVA) procedures with the construction of the International Space Station, problems of astronaut comfort, as well as the reduction of the consumption of energy, became more salient. A shortened liquid cooling/warming garment (SLCWG) has been developed based on physiological principles comparing the efficacy of heat transfer of different body zones; the capability of blood to deliver heat; individual muscle and fat body composition as a basis for individual thermal profiles to customize the zonal sections of the garment; and the development of shunts to minimize or redirect the cooling/warming loop for different environmental conditions, physical activity levels, and emergency situations. The SLCWG has been designed and completed, based on extensive testing in rest, exercise, and antiorthostatic conditions. It is more energy efficient than the LCVG currently used by NASA. The total length of tubing in the SLCWG is approximately 35 percent less and the weight decreased by 20 percent compared to the LCVG. The novel features of the innovation are: 1. The efficiency of the SLCWG to maintain thermal status under extreme changes in body surface temperatures while using significantly less tubing than the LCVG. 2. The construction of the garment based on physiological principles of heat transfer. 3. The identification of the body areas that are most efficient in heat transfer. 4. The inclusion of a hood as part of the garment. 5. The lesser consumption of energy.

Biomedical Use of Aerospace Personal Cooling Garments

NASA Technical Reports Server (NTRS)

Webbon, Bruce W.; Montgomery, Leslie D.; Callaway, Robert K.

1994-01-01

Personal thermoregulatory systems are required during extravehicular activity (EVA) to remove the metabolic heat generated by the suited astronaut. The Extravehicular and Protective Systems (STE) Branch of NASA Ames Research Center has developed advanced concepts or liquid cooling garments for both industrial and biomedical applications for the past 25 years. Examples of this work include: (1) liquid cooled helmets for helicopter pilots and race car drivers; (2) vests for fire and mine rescue personnel; (3) bras to increase the definition of tumors during thermography; (4) lower body garments for young women with erythomelaigia; and (5) whole body garments used by patients with multiple sclerosis (MS). The benefits of the biomedical application of artificial thermoregulation received national attention through two recent events: (1) the liquid-cooled garment technology was inducted into the United States Space Foundation's Space Technology Hall of Fame (1993); and (2) NASA has signed a joint Memorandum of Understanding with the Multiple Sclerosis Association (1994) to share this technology for use with MS patient treatment. The STE Branch is currently pursuing a program to refine thermoregulatory design in light of recent technology developments that might be applicable for use by several medical patient populations. Projects have been initiated to apply thermoregulatory technology for the treatment and/or rehabilitation of patients with spinal cord injuries, multiple sclerosis, migraine headaches, and to help prevent the loss of hair during chemotherapy.

Evaluation of the Efficiency of Liquid Cooling Garments using a Thermal Manikin

DTIC Science & Technology

2005-05-01

temperatures. The software also calculates thermal resistances and evaporative resistances. TM tests were run dry (i.e. no sweating ) and wet (i.e...REPORT DOCUMENTATION PAGE Form ApprovedOMB No . 0704-0188 SECURITY CLASSIFICATION OF REPORT SECURITY CLASSIFICATION OF THIS PAGE SECURITY CLASSIFICATION...OF ABSTRACT 8. M05-17 1. AGENCY USE ONLY (Leave blank) 4. TITLE AND SUBTITLE EVALUATION OF THE EFFICIENCY OF LIQUID COOLING GARMENTS USING A THERMAL

Liquid Cooling Technology Increases Exercise Efficiency

NASA Technical Reports Server (NTRS)

2015-01-01

To keep astronauts' airtight spacesuits from becoming hot and humid, Ames Research Center developed liquid cooling garments that were integrated into each suit's long underwear. Vasper Systems, in San Jose, California, is using the technology in its liquid-cooled compression cuffs, which help people exercise more efficiently by concentrating lactic acid in their muscles.

Development and fabrication of an advanced liquid cooling garment

NASA Technical Reports Server (NTRS)

Leith, J. R.; Hixon, C. W.

1976-01-01

The elastomeric film fin/tube concept which was developed is a composite of polyurethane film, fine expanded silver mesh, a serpentine pattern polyurethane transport tubing and an integral comfort liner, all bonded via adhesive application and vacuum-bagged for final cure. As demonstrated by thermal analysis, the composite garment material is capable of removing a 293 watt (1000 BTU/hr) metabolic load through a head and torso cooling area of .46 sq m (5 sq ft) with tube spacing of slightly under one inch. A total of 60 test elements, each .15m x .15m (6 in. x 6 in.) were fabricated in support of the liquid cooling garment concept development. In parallel with the fabrication of these elements a continuing series of laboratory tests to support the fabrication techniques was carried out. The elements and supporting tests are described.

Cooling Effects of Wearer-Controlled Vaporization for Extravehicular Activity.

PubMed

Tanaka, Kunihiko; Nagao, Daiki; Okada, Kosuke; Nakamura, Koji

2017-04-01

The extravehicular activity suit currently used by the United States in space includes a liquid cooling and ventilation garment (LCVG) that controls thermal conditions. Previously, we demonstrated that self-perspiration for evaporative cooling (SPEC) garment effectively lowers skin temperature without raising humidity in the garment. However, the cooling effect is delayed until a sufficient dose of water permeates and evaporates. In the present study, we hypothesized that wearer-controlled vaporization improves the cooling effect. Six healthy subjects rode a cycle ergometer under loads of 30, 60, 90, and 120 W for durations of 3 min each. Skin temperature and humidity on the back were measured continuously. Subjects wore and tested three garments: 1) a spandex garment without any cooling device (Normal); 2) a simulated LCVG (s-LCVG) or spandex garment knitted with a vinyl tube for flowing and permeating water; and 3) a garment that allowed wearer-controlled vaporization (SPEC-W). The use of s-LCVG reduced skin temperature by 1.57 ± 0.14°C during 12 min of cooling. Wearer-controlled vaporization of the SPEC-W effectively and significantly lowered skin temperature from the start to the end of cycle exercise. This decrease was significantly larger than that achieved using s-LCVG. Humidity in the SPEC-W was significantly lower than that in s-LCVG. This preliminary study suggests that SPEC-W is effective in lowering skin temperature without raising humidity in the garment. The authors think it would be useful in improving the design of a cooling system for extravehicular activity.Tanaka K, Nagao D, Okada K, Nakamura K. Cooling effects of wearer-controlled vaporization for extravehicular activity. Aerosp Med Hum Perform. 2017; 88(4):418-422.

Fire and Ice - Safety, Comfort, and Getting the Firefighters' Job Done

NASA Technical Reports Server (NTRS)

Foley, Tico; Butzer, Melissa

1999-01-01

Daily life for firefighters consists of working with life-threatening hazards in hostile environments. A major hazard is excessive ambient heat. New hazards have arisen from protective gear that was intended to increase survival time of firefighters while finding and rescuing victims. The insulation is so good now that a firefighter's metabolic heat buildup cannot escape. This forces body core temperatures to life threatening levels in about 20 minutes of moderate activity. Using NASA space suit technology, Oceaneering Space Systems developed a liquid cooling garment prototype that will remove up to 250 watts of metabolic heat. After testing and certification as an approved accessory for firefighter use, this garment will be available for use by any individual encapsulated in protective clothing. This demonstration will present a high surface area circulated liquid cooling garment displayed on a mannequin and available for attendees to try on to experience the effects of active cooling.

Evaluation of a liquid cooling garment as a component of the Launch and Entry Suit (LES)

NASA Technical Reports Server (NTRS)

Waligora, J.; Charles, J.; Fritsch, I.; Fortney, S.; Siconolfi, S.; Pepper, L.; Bagian, L.; Kumar, V.

1994-01-01

The LES is a partial pressure suit and a component of the shuttle life support system used during launch and reentry. The LES relies on gas ventilation with cabin air to provide cooling. There are conditions during nominal launch and reentry, landing, and post-landing phases when cabin temperature is elevated. Under these conditions, gas cooling may result in some discomfort and some decrement in orthostatic tolerance. There are emergency conditions involving loss of cabin ECS capability that would challenge crew thermal tolerance. The results of a series of tests are presented. These tests were conducted to assess the effectiveness of a liquid-cooled garment in alleviating thermal discomfort, orthostatic intolerance, and thermal intolerance during simulated mission phases.

NASA Microclimate Cooling Challenges

NASA Technical Reports Server (NTRS)

Trevino, Luis A.

2004-01-01

The purpose of this outline form presentation is to present NASA's challenges in microclimate cooling as related to the spacesuit. An overview of spacesuit flight-rated personal cooling systems is presented, which includes a brief history of cooling systems from Gemini through Space Station missions. The roles of the liquid cooling garment, thermal environment extremes, the sublimator, multi-layer insulation, and helmet visor UV and solar coatings are reviewed. A second section is presented on advanced personal cooling systems studies, which include heat acquisition studies on cooling garments, heat rejection studies on water boiler & radiators, thermal storage studies, and insulation studies. Past and present research and development and challenges are summarized for the advanced studies.

Ice Pack Heat Sink Subsystem - Phase I. [astronaut liquid cooling garment design and testing

NASA Technical Reports Server (NTRS)

Roebelen, G. J., Jr.

1973-01-01

This paper describes the design and test at one-g of a functional laboratory model (non-flight) Ice Pack Heat Sink Subsystem to be used eventually for astronaut cooling during manned space missions. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick connect/disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

High Performance Mars Liquid Cooling and Ventilation Garment Project

NASA Technical Reports Server (NTRS)

Terrier, Douglas; Clayton, Ronald; Whitlock, David; Conger, Bruce

2015-01-01

EVA space suit mobility in micro-gravity is enough of a challenge and in the gravity of Mars, improvements in mobility will enable the suited crew member to efficiently complete EVA objectives. The idea proposed is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area in order to free up the arms and legs by removing the liquid tubes currently used in the ISS EVA suit in the limbs. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased to provide the entire liquid cooling requirement and increase mobility by freeing up the arms and legs. Additional potential benefits of this approach include reduced LCVG mass, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development.

A liquid cooled garment temperature controller based on sweat rate

NASA Technical Reports Server (NTRS)

Chambers, A. B.; Blackaby, J. R.

1972-01-01

An automatic controller for liquid cooled space suits is reported that utilizes human sweat rate as the primary input signal. The controller is so designed that the coolant inlet temperature is inversely proportional to the subject's latent heat loss as evidenced by evaporative water loss.

19. NBS SUIT LAB. STORAGE SHELF WITH LIQUID COOLING VENTILATION ...

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

19. NBS SUIT LAB. STORAGE SHELF WITH LIQUID COOLING VENTILATION GARMENT (LCVG), SUIT GLOVES, WAIST INSERTS, UPPER AND LOWER ARMS (LEFT, FROM TOP TO BOTTOM), LOWER TORSO ASSEMBLIES (LTA) (MIDDLE RIGHT TO LOWER RIGHT). - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

Development of a prototype automatic controller for liquid cooling garment inlet temperature

NASA Technical Reports Server (NTRS)

Weaver, C. S.; Webbon, B. W.; Montgomery, L. D.

1982-01-01

The development of a computer control of a liquid cooled garment (LCG) inlet temperature is descirbed. An adaptive model of the LCG is used to predict the heat-removal rates for various inlet temperatures. An experimental system that contains a microcomputer was constructed. The LCG inlet and outlet temperatures and the heat exchanger outlet temperature form the inputs to the computer. The adaptive model prediction method of control is successful during tests where the inlet temperature is automatically chosen by the computer. It is concluded that the program can be implemented in a microprocessor of a size that is practical for a life support back-pack.

Hemodynamic and thermal responses to head and neck cooling in men and women

NASA Technical Reports Server (NTRS)

Ku, Y. T.; Montgomery, L. D.; Webbon, B. W.

1996-01-01

Personal cooling systems are used to alleviate symptoms of multiple sclerosis and to prevent increased core temperature during daily activities. The objective of this study was to determine the operating characteristics and the physiologic changes produced by short term use of one commercially available thermal control system. A Life Support Systems, Inc. Mark VII portable cooling system and a liquid cooling helmet were used to cool the head and neck regions of 12 female and 12 male subjects (25-55 yr) in this study. The healthy subjects, seated in an upright position at normal room temperature (approximately 21 degrees C), were tested for 30 min with the liquid cooling garment operated at its maximum cooling capacity. Electrocardiograms and scalp and intracranial blood flows were recorded periodically during each test sequence. Scalp, right and left ear, and oral temperatures and cooling system parameters were logged every 5 min. Scalp, right and left ear canal, and oral temperatures were all significantly (P <0.05) reduced by 30 min of head and neck cooling. Oral temperatures decreased approximately 0.2-0.6 degrees C after 30 min and continued to decrease further (approximately 0.1-0.2 degrees C) for a period of approximately 10 min after removal of the cooling helmet. Intracranial blood flow decreased significantly (P < 0.05) during the first 10 min of the cooling period. Both right and left ear temperatures in the women were significantly lower than those of the men during the cooling period. These data indicate that head and neck cooling may be used to reduce core temperature to that needed for symptomatic relief of both male and female multiple sclerosis patients. This study quantifies the operating characteristics of one liquid cooling garment as an example of the information needed to compare the efficiency of other garments operated under different test conditions.

Multifunctional Cooling Garment for Space Suit Environmental Control

NASA Technical Reports Server (NTRS)

Izenson, Michael; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Ferl, Janet; Cencer, Daniel

2015-01-01

Future manned space exploration missions will require space suits with capabilities beyond the current state of the art. Portable Life Support Systems for these future space suits face daunting challenges, since they must maintain healthy and comfortable conditions inside the suit for long-duration missions while minimizing weight and water venting. We have demonstrated the feasibility of an innovative, multipurpose garment for thermal and humidity control inside a space suit pressure garment that is simple, rugged, compact, and lightweight. The garment is a based on a conventional liquid cooling and ventilation garment (LCVG) that has been modified to directly absorb latent heat as well as sensible heat. This hybrid garment will prevent buildup of condensation inside the pressure garment, prevent loss of water by absorption in regenerable CO2 removal beds, and conserve water through use of advanced lithium chloride absorber/radiator (LCAR) technology for nonventing heat rejection. We have shown the feasibility of this approach by sizing the critical components for the hybrid garment, developing fabrication methods, building and testing a proof-of-concept system, and demonstrating by test that its performance is suitable for use in space suit life support systems.

Multifunctional Cooling Garment for Space Suit Environmental Control

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Ferl, Janet

2014-01-01

Future manned space exploration missions will require space suits with capabilities beyond the current state of the art. Portable Life Support Systems for these future space suits face daunting challenges, since they must maintain healthy and comfortable conditions inside the suit for longduration missions while minimizing weight and water venting. We have demonstrated the feasibility of an innovative, multipurpose garment for thermal and humidity control inside a space suit pressure garment that is simple, rugged, compact, and lightweight. The garment is a based on a conventional liquid cooling and ventilation garment (LCVG) that has been modified to directly absorb latent heat as well as sensible heat. This hybrid garment will prevent buildup of condensation inside the pressure garment, prevent loss of water by absorption in regenerable CO2 removal beds, and conserve water through use of advanced lithium chloride absorber/radiator (LCAR) technology for nonventing heat rejection. We have shown the feasibility of this approach by sizing the critical components for the hybrid garment, developing fabrication methods, building and testing a proof-of-concept system, and demonstrating by test that its performance is suitable for use in space suit life support systems.

Postponement of incipient collapse due to work-induced heat stress by limited cooling

NASA Technical Reports Server (NTRS)

Blockley, W. V.

1973-01-01

Four subjects completed five treadmill training sessions under comfortable to cool conditions and were calibrated to find an optimum combination of speed and grade on the treadmill which would produce a metabolic rate of 2000 Btu-hr. Dressed in an Apollo liquid cooling garment, each man underwent a total of four experiments in which the rate of heat extraction from the liquid cooling garment was adjusted to an amount which would cause a storage within the body of 1000 Btu/hr. Physiological measurements included skin temperature at 9 locations, rectal and ear canal probes, and heart rate. The increases in tolerance time for the various subjects and the various methods of emergency cooling, ranged from a low of six minutes to a high of 48 minutes, or from 8 to 102% of the baseline tolerance times. The largest gains were achieved in a subject whose tolerance endpoint was atypical, and whose baseline heat tolerance was unsually low.

Artemyev post-EVA

NASA Image and Video Library

2014-06-19

Cosmonaut Oleg Artemyev, Expedition 40 flight engineer, is photographed still wearing his liquid cooling and ventilation garment after a Russian Extravehicular Activity (EVA). Artemyev is standing in his crew quarters (CQ).

Effects of liquid cooling garments on recovery and performance time in individuals performing strenuous work wearing a firefighter ensemble.

PubMed

Kim, Jung-Hyun; Coca, Aitor; Williams, W Jon; Roberge, Raymond J

2011-07-01

This study investigated the effects of body cooling using liquid cooling garments (LCG) on performance time (PT) and recovery in individuals wearing a fully equipped prototype firefighter ensemble (PFE) incorporating a self-contained breathing apparatus (SCBA). Six healthy male participants (three firefighters and three non-firefighters) completed six experimental sessions in an environmental chamber (35°C, 50% relative humidity), consisting of three stages of 15 min exercise at 75% VO2max, and 10 min rest following each exercise stage. During each session, one of the following six conditions was administered in a randomized order: control (no cooling, CON); air ventilation of exhaust SCBA gases rerouted into the PFE (AV); top cooling garment (TCG); TCG combined with AV (TCG+AV); a shortened whole body cooling garment (SCG), and SCG combined with AV (SCG+AV). Results showed that total PT completed was longer under SCG and SCG+AV compared with CON, AV, TCG, and TCG+AV (p<0.01). Magnitude of core temperature (Tc) elevation was significantly decreased when SCG was utilized (p<0.01), and heart rate recovery rate (10 min) was enhanced under SCG, SCG+AV, TCG, and TCG+AV compared with CON (p<0.05). Estimated Esw rate (kg·h(-1)) was the greatest in CON, 1.62 (0.37), and the least in SCG+AV 0.98 (0.44): (descending order: CON>AV>TCG=TCG+AV>SCG>SCG+AV) without a statistical difference between the conditions (p<0.05). Results of the present study suggest that the application of LCG underneath the PFE significantly improves the recovery during a short period of rest and prolongs performance time in subsequent bouts of exercise. LCG also appears to be an effective method for body cooling that promotes heat dissipation during uncompensable heat stress.

Evaluation of Personal Cooling Systems in Conjunction with Explosive Ordnance Disposal Suits

DTIC Science & Technology

1992-06-01

of thermal comfort and perceived exertion. The results indicated that wearing the EOD suit produces significant increases in thermal physiological...indicated reduced perceived exertion levels and improved thermal comfort when wearing the liquid-cooling garment with a EOD suit. In contrast, the ribbed

Post-exercise cooling techniques in hot, humid conditions.

PubMed

Barwood, Martin James; Davey, Sarah; House, James R; Tipton, Michael J

2009-11-01

Major sporting events are often held in hot and humid environmental conditions. Cooling techniques have been used to reduce the risk of heat illness following exercise. This study compared the efficacy of five cooling techniques, hand immersion (HI), whole body fanning (WBF), an air cooled garment (ACG), a liquid cooled garment (LCG) and a phase change garment (PCG), against a natural cooling control condition (CON) over two periods between and following exercise bouts in 31 degrees C, 70%RH air. Nine males [age 22 (3) years; height 1.80 (0.04) m; mass 69.80 (7.10) kg] exercised on a treadmill at a maximal sustainable work intensity until rectal temperature (T (re)) reached 38.5 degrees C following which they underwent a resting recovery (0-15 min; COOL 1). They then recommenced exercise until T (re) again reached 38.5 degrees C and then undertook 30 min of cooling with (0-15 min; COOL 2A), and without face fanning (15-30 min; COOL 2B). Based on mean body temperature changes (COOL 1), WBF was most effective in extracting heat: CON 99 W; WBF: 235 W; PCG: 141 W; HI: 162 W; ACG: 101 W; LCG: 49 W) as a consequence of evaporating more sweat. Therefore, WBF represents a cheap and practical means of post-exercise cooling in hot, humid conditions in a sporting setting.

Multilayer composite material and method for evaporative cooling

NASA Technical Reports Server (NTRS)

Buckley, Theresa M. (Inventor)

2002-01-01

A multilayer composite material and method for evaporative cooling of a person employs an evaporative cooling liquid that changes phase from a liquid to a gaseous state to absorb thermal energy. The evaporative cooling liquid is absorbed into a superabsorbent material enclosed within the multilayer composite material. The multilayer composite material has a high percentage of the evaporative cooling liquid in the matrix. The cooling effect can be sustained for an extended period of time because of the high percentage of phase change liquid that can be absorbed into the superabsorbent. Such a composite can be used for cooling febrile patients by evaporative cooling as the evaporative cooling liquid in the matrix changes from a liquid to a gaseous state to absorb thermal energy. The composite can be made with a perforated barrier material around the outside to regulate the evaporation rate of the phase change liquid. Alternatively, the composite can be made with an imperveous barrier material or semipermeable membrane on one side to prevent the liquid from contacting the person's skin. The evaporative cooling liquid in the matrix can be recharged by soaking the material in the liquid. The multilayer composite material can be fashioned into blankets, garments and other articles.

Phase II Testing of Liquid Cooling Garments Using a Sweating Manikin, Controlled by a Human Physiological Model

NASA Technical Reports Server (NTRS)

Paul, Heather; Trevino, Luis; Bue,Grant; Rugh, John

2006-01-01

An Advanced Automotive Manikin (ADAM) developed at the National Renewable Energy Laboratory (NREL) is used to evaluate NASA's liquid cooling garments (LCGs) used in advanced space suits for extravehicular applications. The manikin has 120 separate heated/sweating zones and is controlled by a finite element physiological model of the human thermoregulatory system. Previous testing showed the thermal sensation and comfort followed the expected trends as the LCG inlet fluid temperature was changed. The Phase II test data demonstrates the repeatability of ADAM by retesting the baseline LCG. Skin and core temperature predictions using ADAM in an LCG/Arctic suit combination are compared to NASA physiological data to validate the manikin/model. Additional LCG configurations are assessed using the manikin and compared to the baseline LCG. Results can extend to other personal protective clothing, including HAZMAT suits, nuclear/biological/chemical protective suits, and fire protection suits.

Physiological and Thermal Responses of MS Patients to Head and Vest Cooling: A Case Study

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Webbon, Bruce W.; Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Kliss, Mark (Technical Monitor)

1997-01-01

Personal cooling systems are used to alleviate symptoms of multiple sclerosis (MS) and to prevent increased core temperature during daily activities. The objective of this study was to determine the operating characteristics and the physiologic changes produced by short term application of the stationary thermal control system used by most clinical institutions. The Life Enhancement Tech (LET) Mark VII portable cooling system and a lightweight Head-vest active cooling garment were used to cool the head and chest regions of 4 male and 3 female MS patients (30 to 66 yrs. old) in this study. The subjects, seated in an upright position at normal room temperature (approx. 24 C), were tested for 60 min. with the liquid cooling garment (LCG) operated at 50 F. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures, heart rate, respiration, and an activity index were recorded continuously on a U.F.I., Inc., Biolog ambulatory monitor. All temperature responses showed extreme variation among subjects. The cold-sensitive subject's rectal temperature increased initially in response to cooling; the heat sensitive subject's rectal temperature decreased. After 40 min. of cooling and during recovery, all subjects'rectal temperatures decreased. Oral temperatures began to decrease after 30 min. of cooling. After 60 min. of cooling, temperature drops ranged from approx. 0.3 - 0.8 C. Oral temperatures continued to decrease during recovery (approx. 0.2 C). The car temperature of the heat sensitive subject was increased after cooling, other subjects exhibited an ear temperature decrease (0.0 - 0.5 C). These data indicate that head and vest cooling may be used to reduce the oral temperatures of MS patients by the approximate amount needed for symptomatic relief as shown by other researchers. The combination of a small subject population and a large subject variance does not permit us to draw statistical conclusions about the temperature response of MS patients. An individual's heat or cold sensitivity may influence their thermal response to cooling. This factor should be considered in the prescribed use of liquid cooling garments in the therapeutic management of MS.

Enhancement of Cognitive Processing by Multiple Sclerosis Patients Using Liquid Cooling Technology: A Case Study

NASA Technical Reports Server (NTRS)

Montgomery, Leslie D.; Montgomery, Richard W.; Ku, Yu-Tsuan; Luna, Bernadette (Technical Monitor)

1997-01-01

Cognitive dysfunction is a common symptom in patients with multiple sclerosis (MS). This can have a significant impact on the quality of life of both the patient and of their primary care giver. This case study explores the possibility that liquid cooling therapy may be used to enhance the cognitive processing of MS patients in the same way that it provides temporary relief of some physical impairment. Two MS patients were presented a series of pattern discrimination tasks before and after being cooled with a liquid cooling garment for a one hour period. The subject whose ear temperature was reduced during cooling showed greater electroencephalographic (EEG) activity and scored much better on the task after cooling. The patient whose ear temperature was unaffected by cooling showed less EEG activity and degraded performance after the one hour cooling period.

Reexamination of METMAN, Recommendations on Enhancement of LCVG, and Development of New Concepts for EMU Heat Sink

NASA Technical Reports Server (NTRS)

Karimi, Amir

1990-01-01

METMAN is a 41-node transient metabolic computer code developed in 1970 and revised in 1989 by Lockheed Engineering and Sciences, Inc. This program relies on a mathematical model to predict the transient temperature distribution in a body influenced by metabolic heat generation and thermal interaction with the environment. A more complex 315-node model is also available that not only simulates the thermal response of a body exposed to a warm environment, but is also capable of describing the thermal response resulting from exposure to a cold environment. It is important to compare the two models for the prediction of the body's thermal response to metabolic heat generation and exposure to various environmental conditions. Discrepancies between the twi models may warrant an investigation of METMAN to ensure its validity for describing the body's thermal response in space environment. The Liquid Cooling and Ventilation Garment is a subsystem of the Extravehicular Mobility Unit (EMU). This garment, worn under the pressure suit, contains the liquid cooling tubing and gas ventilation manifolds; its purpose is to alleviate or reduce thermal stress resulting from metabolic heat generation. There is renewed interest in modifying this garment through identification of the locus of maximum heat transfer at body-liquid cooled tubing interface. The sublimator is a vital component of the Primary Life Support System (PLSS) in the EMU. It acts as a heat sink to remove heat and humidity from the gas ventilating circuit and the liquid cooling loop of the LCVG. The deficiency of the sublimator is that the ice, used as the heat sink, sublimates into space. There is an effort to minimize water losses in the feedwater circuit of the EMU. This requires developing new concepts to design an alternative heat sink system. Efforts are directed to review and verify the heat transfer formulation of the analytical model employed by METMAN. A conceptual investigation of regenerative non-venting heat-sink subsystem for the EMU is recommended.

Bio-Contamination Control for Spacesuit Garments - A Preliminary Study

NASA Technical Reports Server (NTRS)

Rhodes, Richard; Korona, Adam; Orndoff, Evelyn; Ott, Mark; Poritz, Darwin

2010-01-01

This paper outlines a preliminary study to review, test, and improve upon the current state of spacesuit bio-contamination control. The study includes an evaluation of current and advanced suit materials, ground and on-orbit cleaning methods, and microbial test and analysis methods. The first aspect of this study was to identify potential anti-microbial textiles and cleaning agents, and to review current microbial test methods. The anti-microbial cleaning agent and textile market survey included a review of current commercial-off-the-shelf (COTS) products that could potentially be used as future space flight hardware. This review included replacements for any of the softgood layers that may become contaminated during an extravehicular activity (EVA), including the pressure bladder, liquid cooling garment, and ancillary comfort undergarment. After a series of COTS anti-microbial textiles and clean ing agents were identified, a series of four tests were conducted: (1) a stacked configuration test that was conducted in order to review how bio-contamination would propagate through the various suit layers, (2) a individual materials test that evaluated how well each softgood layer either promoted or repressed growth, (3) a cleaning agent test that evaluated the efficacy on each of the baseline bladders, and (4) an evaluation of various COTS anti-microbial textiles. All antimicrobial COTS materials tested appeared to control bacteria colony forming unit (CFU) growth better than the Thermal Comfort Undergarment (TCU) and ACES Liquid Cooling Garment (LCG)/EMU Liquid Cooling Ventilation Garment (LCVG) materials currently in use. However, a comparison of fungi CFU growth in COTS to current suit materials appeared to vary per material. All cleaning agents tested in this study appeared to inhibit the level of bacteria and fungi growth to acceptable levels for short duration tests. While several trends can be obtained from the current analysis, a series of test improvements are described for future microbial testing.

KENNEDY SPACE CENTER, FLA. - Seen in the photo is one end of the airlock that is installed in the payload bay of orbiter Discovery. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - Seen in the photo is one end of the airlock that is installed in the payload bay of orbiter Discovery. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

KENNEDY SPACE CENTER, FLA. - A worker in the Orbiter Processing Facility checks the open hatch of the airlock in Discovery’s payload bay. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - A worker in the Orbiter Processing Facility checks the open hatch of the airlock in Discovery’s payload bay. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

Comparison of different cooling regimes within a shortened liquid cooling/warming garment on physiological and psychological comfort during exercise

NASA Technical Reports Server (NTRS)

Leon, Gloria R.; Koscheyev, Victor S.; Coca, Aitor; List, Nathan

2004-01-01

The aim of this study was to compare the effectiveness of different cooling regime intensities to maintain physiological and subjective comfort during physical exertion levels comparable to that engaged in during extravehicular activities (EVA) in space. We studied eight subjects (six males, two females) donned in our newly developed physiologically based shortened liquid cooling/warming garment (SLCWG). Rigorous (condition 1) and mild (condition 2) water temperature cooling regimes were compared at physical exertion levels comparable to that performed during EVA to ascertain the effectiveness of a lesser intensity of cooling in maintaining thermal comfort, thus reducing energy consumption in the portable life support system. Exercise intensity was varied across stages of the session. Finger temperature, rectal temperature, and subjective perception of overall body and hand comfort were assessed. Finger temperature was significantly higher in the rigorous cooling condition and showed a consistent increase across exercise stages, likely due to the restriction of heat extraction because of the intensive cold. In the mild cooling condition, finger temperature exhibited an overall decline with cooling, indicating greater heat extraction from the body. Rectal temperature was not significantly different between conditions, and showed a steady increase over exercise stages in both rigorous and mild cooling conditions. Ratings of overall comfort were 30% higher (more positive) and more stable in mild cooling (p<0.001). The mild cooling regime was more effective than rigorous cooling in allowing the process of heat exchange to occur, thus maintaining thermal homeostasis and subjective comfort during physical exertion.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a cameraman films part of Discovery’s payload bay for a special feature on the KSC Web. In the background is the open hatch of the airlock, located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a cameraman films part of Discovery’s payload bay for a special feature on the KSC Web. In the background is the open hatch of the airlock, located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

KENNEDY SPACE CENTER, FLA. - Standing inside Discovery’s payload bay, Carol Scott (right), lead orbiter engineer, talks about her job as part of a special feature for the KSC Web. With his back to the camera is Bill Kallus, Media manager in the KSC Web Studio. Behind Scott can be seen the open hatch of the airlock, which provides support functions such as airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - Standing inside Discovery’s payload bay, Carol Scott (right), lead orbiter engineer, talks about her job as part of a special feature for the KSC Web. With his back to the camera is Bill Kallus, Media manager in the KSC Web Studio. Behind Scott can be seen the open hatch of the airlock, which provides support functions such as airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

Hemodynamic and Thermal Responses to Head and Neck Cooling in Men and Women

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Carbo, Jorge E.; Webbon, Bruce W.

1995-01-01

Personal cooling systems are used to alleviate symptoms of multiple sclerosis and to prevent increased core temperature during daily activities. Configurations of these systems include passive ice vests and circulating liquid cooling garments (LCGs) in the forms of vests, cooling caps and combined head and neck cooling systems. However, little information is available oil the amount or heat that can be extracted from the body with these systems or the physiologic changes produced by routine operation of these systems. The objective of this study was to determine the operating characteristics and the physiologic change, produced by short term use of one commercially available thermal control system.

Shuttle Spacesuit: Fabric/LCVG Model Validation

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Tweed, J.; Zeitlin, C.; Kim, M.-H. Y.; Anderson, B. M.; Cucinotta, F. A.; Ware, J.; Persans, A. E.

2001-01-01

A detailed spacesuit computational model is being developed at the Langley Research Center for radiation exposure evaluation studies. The details of the construction of the spacesuit are critical to estimation of exposures and assessing the risk to the astronaut on EVA. Past evaluations of spacesuit shielding properties assumed the basic fabric lay-up (Thermal Micrometeroid Garment, fabric restraints, and pressure envelope) and Liquid Cooling and Ventilation Garment (LCVG) could be homogenized as a single layer overestimating the protective properties over 60 percent of the fabric area. The present spacesuit model represents the inhomogeneous distributions of LCVG materials (mainly the water filled cooling tubes). An experimental test is performed using a 34-MeV proton beam and highresolution detectors to compare with model-predicted transmission factors. Some suggestions are made on possible improved construction methods to improve the spacesuit's protection properties.

A Laboratory Evaluation of Liquid Cooled Vests for Non-Combatants

DTIC Science & Technology

1986-04-01

intermediate between these extremes have been or could be used by, for example, firefighters, stokers, furnace workers , surgeons (to inhibit sweating ...M., and Stein, R.W. (1976) An ice-cooling garment for mine rescue workers . Report PB-254487, US Department of Commerce, Washington DC, USA. Edwards...ermoregulatory sdeating of three sabjects. All su:-ects stated that the vests co-vide_ so,-e relief from heat stress, but no effects of eat st-ess on

Protective Effects of the Launch/Entry Suit (LES) and the Liquid Cooling Garment(LCG) During Re-entry and Landing After Spaceflight

NASA Technical Reports Server (NTRS)

Perez, Sondra A.; Charles, John B.; Fortner, G. William; Hurst, Victor, IV; Meck, Janice V.

2002-01-01

Heart rate and arterial pressure were measured during shuttle re-entry, landing and initial standing in crewmembers with and without inflated anti-g suits and with and without liquid cooling garments (LCG). Preflight, three measurements were obtained seated, then standing. Prior to and during re-entry, arterial pressure and heart rate were measured every five minutes until wheels stop (WS). Then crewmembers initiated three seated and three standing measurements. In subjects without inflated anti-g suits, SBP and DBP were significantly lower during preflight standing (P = 0.006; P = 0.001 respectively) and at touchdown (TD) (P = 0.001; P = 0.003 respectively); standing SBP was significantly lower after WS. on-LeG users developed significantly higher heart rates during re-entry (P = 0.029, maxG; P = 0.05, TD; P = 0.02, post-WS seated; P = 0.01, post-WS standing) than LCG users. Our data suggest that the anti-g suit is effective, but the combined anti-g suit with LCG is more effective.

Thermal Performance Testing of EMU and CSAFE Liquid Cooling Garments

NASA Technical Reports Server (NTRS)

Rhodes, Richard; Bue, Grant; Hakam, Mark; Radford, Tamara

2013-01-01

Future exploration missions require the development of a new liquid cooling garment (LCG) that offers greater system reliability, is more comfortable, and maximizes thermal performance. To inform the development of a future LCG a thermal performance test was conducted to evaluate three factors: (1) the effect of the thermal comfort undergarment (TCU) on tactile and thermal comfort, (2) the comparable thermal performance of an CSAFE developed engineering evaluation unit (EEU) LCG, which uses a commercial-off-the-shelf (COTS) wicking garment as the base, and (3) the performance of a torso or upper body only LCG configuration to evaluate a proposed auxiliary loop configuration. To evaluate the thermal performance of each configuration a metabolic suit test was conducted, utilizing suited subjects to generate metabolic heat by walking on a treadmill at various speeds. Three (3) test subjects of similar height and weight produced a metabolic load for five tests by either resting (300-600 BTU/hr), walking at a slow pace (1200 BTU/hr), and walking at a brisk pace (2200 BTU/hr). During the test, data was collected that would allow us to track the heat transfer to the LCG and ventilation system to determine the thermal performance of the LCG configurations. Four different test configurations were tested, with one configuration tested twice. The test results show that the CSAFE EEU LCG and EMU LCG had comparable performance. The testing also showed that an auxiliary loop LCG, sized similarly to the shirt-only configuration, should provide adequate cooling for contingency scenarios. Finally, the testing showed the previous analysis that assumed a UA deterioration from the TCU was too conservative and the TCU may prove to be acceptable for future development with additional analysis and testing.

Multi-zone cooling/warming garment

NASA Technical Reports Server (NTRS)

Leon, Gloria R. (Inventor); Koscheyev, Victor S. (Inventor); Dancisak, Michael J. (Inventor)

2006-01-01

A thermodynamically efficient garment for cooling and/or heating a human body. The thermodynamic efficiency is provided in part by targeting the heat exchange capabilities of the garment to specific areas and/or structures of the human body. The heat exchange garment includes heat exchange zones and one or more non-heat exchange zones, where the heat exchange zones are configured to correspond to one or more high density tissue areas of the human body when the garment is worn. A system including the garment can be used to exchange heat with the adjacent HD tissue areas under the control of a feedback control system. Sensed physiological parameters received by the feedback control system can be used to adjust the characteristics of heat exchange fluid moving within the heat exchange garment.

High Performance Torso Cooling Garment

NASA Technical Reports Server (NTRS)

Conger, Bruce

2016-01-01

The concept proposed in this paper is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area, which could facilitate removal of LCVG tubing from the arms and legs, thereby increasing suited crew member mobility. EVA space suit mobility in micro-gravity is challenging, and it becomes even more challenging in the gravity of Mars. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased. This increase in efficiency could provide the required liquid cooling via torso tubing only; no arm or leg LCVG tubing would be required. Benefits of this approach include increased crewmember mobility, reduced LCVG mass, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development. This report describes analysis and test activities performed to evaluate the potential improvements to the thermal performance of the LCVG. Analyses evaluated potential tube shapes for improving the thermal performance of the LCVG. The analysis results fed into the selection of flat flow strips to improve thermal contact with the skin of the suited test subject. Testing of small segments was performed to compare thermal performance of the tubing approach of the current LCVG to the flat flow strips proposed as the new concept. Results of the testing is presented along with recommendations for future development of this new concept.

High Performance Torso Cooling Garment

NASA Technical Reports Server (NTRS)

Conger, Bruce; Makinen, Janice

2016-01-01

The concept proposed in this paper is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area, which could facilitate removal of LCVG tubing from the arms and legs, thereby increasing suited crew member mobility. EVA space suit mobility in micro-gravity is challenging, and it becomes even more challenging in the gravity of Mars. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased. This increase in efficiency could provide the required liquid cooling via torso tubing only; no arm or leg LCVG tubing would be required. Benefits of this approach include increased crewmember mobility, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development. This report describes analysis and test activities performed to evaluate the potential improvements to the thermal performance of the LCVG. Analyses evaluated potential tube shapes for improving the thermal performance of the LCVG. The analysis results fed into the selection of flat flow strips to improve thermal contact with the skin of the suited test subject. Testing of small segments was performed to compare thermal performance of the tubing approach of the current LCVG to the flat flow strips proposed as the new concept. Results of the testing is presented along with recommendations for future development of this new concept.

Implications of Advanced Crew Escape Suit Transpiration for the Orion Program

NASA Technical Reports Server (NTRS)

Bue, Grant; Kuznetz, Lawrence

2009-01-01

Human testing was conducted to more fully characterize the integrated performance of the Advanced Crew Escape Suit (ACES) with liquid cooling provide by an Individual Cooling Unit (ICU) across a broad range of environmental conditions and metabolic rates. Together with a correlation for the ACES Liquid Cooling Garment as a function of inlet temperature, metabolic rate, and crew size, a reasonably conservative correlation for core temperature was achieved for the human thermal model applied to the ACES with ICU cooling. A key observation for this correlation was accounting for transpiration of evaporated sweat through the Gortex(Registered TradeMark) liner of the ACES indicated by as much as 0.6 lbm of sweat evaporated over the course of the 1 hour test profile, most of which could not be attributed to respiration or head sweat evaporation of the crew. Historically it has been assumed that transpiration was not an important design feature of the ACES suit. The correlated human thermal model will show transpiration to be highly useful in hot survival situations for the Orion Program when adequate liquid cooling is not available.

Physiologic Responses Produced by Active and Passive Personal Cooling Vests

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Luna, Bernadette

2000-01-01

Personal thermoregulatory systems which provide chest cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to document and compare the subjects' response to three cooling vests in their recommended configurations. The Life Enhancement Tech (LET) lightweight active cooling vest with cap, the MicroClimate Systems Change of Phase garment (MCS), and the Steele Vest were each used to cool the chest regions of 12 male and 8 female Healthy subjects (21 to 69 yr.) in this study. The subjects, seated in an upright position at normal room temperature (approx. 22 C), were tested for 60 min. with one of the cooling garments. The LET active garment had an initial coolant fluid inlet temperature of 60 F, and was ramped down to 50 F. Oral, right and left ear canal temperatures were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; and respiration were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. For men, all three vests had similar, significant cooling effects. Decreases in the average rectal temperature, oral temperature, and ear canal temperatures were approximately 0.2 C, 0.2 C and 0.1 C, respectively. In contrast to the men, the female subjects wearing the MCS and Steel vests had similar cooling responses in which the core temperature remained elevated and oral and ear canal temperatures did not drop. The LET active garment cooled most of the female subjects in this study; rectal, oral and ear temperature decreased about 0.2 C, 0.3 C and 0.3 C, respectively. These results show that the garment configurations tested do not elicit a similar thermal response in all subjects. A gender difference is evident. The LET active garment configuration was most effective in decreasing temperatures of the female subjects; the MCS vest was least effective. For male subjects, the three vests appear to be more nearly equivalent. The active garment system under study included a cooling cap, which may account for some of the difference in response.

Control of thermal balance by a liquid circulating garment based on a mathematical representation of the human thermoregulatory system. Ph.D. Thesis - California Univ., Berkeley

NASA Technical Reports Server (NTRS)

Kuznetz, L. H.

1976-01-01

Test data and a mathematical model of the human thermoregulatory system were used to investigate control of thermal balance by means of a liquid circulating garment (LCG). The test data were derived from five series of experiments in which environmental and metabolic conditions were varied parametrically as a function of several independent variables, including LCG flowrate, LCG inlet temperature, net environmental heat exchange, surrounding gas ventilation rate, ambient pressure, metabolic rate, and subjective/obligatory cooling control. The resultant data were used to relate skin temperature to LCG water temperature and flowrate, to assess a thermal comfort band, to demonstrate the relationship between metabolic rate and LCG heat dissipation, and so forth. The usefulness of the mathematical model as a tool for data interpretation and for generation of trends and relationships among the various physiological parameters was also investigated and verified.

Space Technology: A study of the significance of recognition for innovators of spinoff technologies. A case study on the impact of the space technology hall of fame award

NASA Technical Reports Server (NTRS)

1993-01-01

This report represents the preliminary effort in studying the significance of recognition for innovators of spinoff technologies. The purpose of this initial year's effort in this area was to gather preliminary data and define the direction for the remainder of the research. This report focuses on the most recent recipients of the Hall of Fame Award, the developers of liquid-cooled garments. Liquid-cooled garments technology and its spinoffs were used as a case study to define and explore the factors involved in technology transfer and to consider the possible incentives in developing commercial applications including the Hall of Fame Award. Through interviews, views of award recipients were obtained on factors encouraging spinoffs as well as impediments to spinoffs. The researchers observed complex inter-relationships among the significant entities (government, individuals, large and small business), the importance of people, the importance of resource availability, and the significance of intrinsic motivation; drew preliminary conclusions pertaining to the direct and indirect influence of recognition like the Hall of Fame Award; and planned the direction for next year's follow-on research.

Determination of Time Required for Materials Exposed to Oxygen to Return to Reduced Flammability

NASA Technical Reports Server (NTRS)

Harper, Susana; Hirsch, David; Smith, Sarah

2009-01-01

Increased material flammability due to exposure to high oxygen concentrations is a concern from both a safety and operational perspective. Localized, high oxygen concentrations can occur when exiting a higher oxygen concentration environment due to material saturation, as well as oxygen entrapment between barrier materials. Understanding of oxygen diffusion and permeation and its correlation to flammability risks can reduce the likelihood of fires while improving procedures as NASA moves to longer missions with increased extravehicular activities in both spacecraft and off-Earth habitats. This paper examines the time required for common spacecraft materials exposed to oxygen to return to reduced flammability after removal from the increased oxygen concentration environment. Specifically, NASA-STD-6001A maximum oxygen concentration testing and ASTM F-1927 permeability testing were performed on Nomex 4 HT90-40, Tiburon 5 Surgical Drape, Cotton, Extravehicular Mobility Unit (EMU) Liquid-Cooled Ventilation Garment, EMU Thermal Comfort Undergarment, EMU Mosite Foam with Spandex Covering, Advanced Crew Escape Suit (ACES) Outer Cross-section, ACES Liquid Cooled Garment (LCG), ACES O2 Hose Material, Minicel 6 Polyethylene Foam, Minicel Polyethylene Foam with Nomex Covering, Pyrell Polyurethane Foam, and Zotek 7 F-30 Foam.

Physiologic and Functional Responses of MS Patients to Body Cooling Using Commercially Available Cooling Garments

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Lee, Hank C.; Luna, Bernadette; Webbon, Bruce W.; Mead, Susan C. (Technical Monitor)

1999-01-01

Personal cooling systems are widely used in industrial and aerospace environments to alleviate thermal stress. Increasingly they are also used by heat sensitive multiple sclerosis (HSMS) patients to relieve symptoms and improve quality of life. There are a variety of cooling systems commercially available to the MS community. However, little information is available regarding the comparative physiological changes produced by routine operation of these various systems. The objective of this study was to document and compare the patient response to two passive cooling vests and one active cooling garment. The Life Enhancement Technology, Inc. (LET) lightweight active cooling vest with cap, the MicroClimate Systems (MCS) Change of Phase garment, and the Steele Vest were each used to cool 13 male and 13 female MS subjects (31 to 67 yr.) in this study. The subjects, seated in an upright position at normal room temperature (approximately 22 C), were tested with one of the cooling garments. Oral, fight and left ear temperatures were logged manually every 5 min. An-n, leg, chest and rectal temperatures; heart rate; and respiration were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. Each subject was given a series of subjective and objective evaluation tests before and after cooling. The LET and Steele vests test groups had similar, significant (P less than 0.01) cooling effects on oral and ear canal temperature, which decreased approximately 0.4 C, and 0.3 C, respectively. Core temperature increased (N.S.) with all three vests during cooling. The LET vest produced the coldest (P less than 0.01) skin temperature. Overall, the LET vest provided the most improvement on subjective and objective performance measures. These results show that the garment configurations tested do not elicit a similar thermal response in all MS patients. Cooling with the LET active garment configuration resulted in the lowest body temperatures for the MS subjects; cooling with the MCS vest was least effective. For functional responses, the LET test group performed better than the other two vests.

Thermal Manikin Evaluation of Passive and Active Cooling Garments to Improve Comfort of Military Body Armor

DTIC Science & Technology

2007-08-01

increased TM evaporative cooling potential approximately 18%. Military use of these garments could allow for increases in sweat evaporation and overall thermal comfort during operational heat exposure.

Cool Sportswear

NASA Technical Reports Server (NTRS)

1982-01-01

New athletic wear design based on the circulating liquid cooling system used in the astronaut's space suits, allows athletes to perform more strenuous activity without becoming overheated. Techni-Clothes gear incorporates packets containing a heat-absorbing gel that slips into an insulated pocket of the athletic garment and is positioned near parts of the body where heat transfer is most efficient. A gel packet is good for about one hour. Easily replaced from a supply of spares in an insulated container worn on the belt. The products, targeted primarily for runners and joggers and any other athlete whose performance may be affected by hot weather, include cooling headbands, wrist bands and running shorts with gel-pack pockets.

Water immersion facility general description, spacecraft design division, crew station branch

NASA Technical Reports Server (NTRS)

1978-01-01

The Water Immersion Facility provides an accurate, safe, neutral buoyancy simulation of zero gravity conditions for development of equipment and procedures, and the training of crews. A detailed description is given of some of the following systems: (1) water tank and support equipment; (2) communications systems; (3) environmental control and liquid cooled garment system (EcS/LCG); (4) closed circuit television system; and (5) medical support system.

KSC-04PD-1133

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Technicians in the Orbiter Processing Facility attach a crane to Discoverys airlock before lifting it for installation. The airlock is located inside the orbiters payload bay and is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, and communications. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005. STS-114 mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

Advanced Design Heat PumpRadiator for EVA Suits

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Chen, Weibo; Passow, Christian; Phillips, Scott; Trevino, Luis

2009-01-01

Absorption cooling using a LiCl/water heat pump can enable lightweight and effective thermal control for EVA suits without venting water to the environment. The key components in the system are an absorber/radiator that rejects heat to space and a flexible evaporation cooling garment that absorbs heat from the crew member. This paper describes progress in the design, development, and testing of the absorber/radiator and evaporation cooling garment. New design concepts and fabrication approaches will significantly reduce the mass of the absorber/radiator. We have also identified materials and demonstrated fabrication approaches for production of a flexible evaporation cooling garment. Data from tests of the absorber/radiator s modular components have validated the design models and allowed predictions of the size and weight of a complete system.

Design and testing of a liquid cooled garment for hot environments.

PubMed

Guo, Tinghui; Shang, Bofeng; Duan, Bin; Luo, Xiaobing

2015-01-01

Liquid cooled garments (LCGs) are considered a viable method to protect individuals from hyperthermia and heat-related illness when working in thermally stressful environments. While the concept of LCGs was proposed over 50 years ago, the design and testing of these systems is undeveloped and stands in need of further study. In this study, a detailed heat transfer model of LCG in a hot environment was built to analyze the effects of different factors on the LCG performance, and to identify the main limitations to achieve maximum performance. An LCG prototype was designed and fabricated. Series of tests were done by a modified thermal manikin method to validate the heat transfer model and to evaluate the thermal properties. Both experimental and predicted results show that the heat flux components match the heat balance equation with an error of less than 10% at different flowrate. Thermal resistance analysis also manifests that the thermal resistance between the cooling water and the ambient (R2) is more sensitive to the flowrate than to the one between the skin surface and the cooling water (R1). When the flowrate increased from 225 to 544 mL/min, R2 decreased from 0.5 to 0.3 °C m(2)/W while R1 almost remained constant. A specific duration time was proposed to assess the durability and an optimized value of 1.68 h/kg was found according to the heat transfer model. The present heat transfer model and specific duration time concept could be used to optimize and evaluate this kind of LCG respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cockrell and Rominger go through de-orbit preparations in the flight deck

NASA Image and Video Library

1996-12-06

STS080-360-002 (19 Nov.-7 Dec. 1996) --- From the commander's station on the port side of the space shuttle Columbia's forward flight deck, astronaut Kenneth D. Cockrell prepares for a minor firing of Reaction Control System (RCS) engines during operations with the Wake Shield Facility (WSF). The activity was recorded with a 35mm camera on flight day seven. The commander is attired in a liquid-cooled biological garment.

LOx breathing system with gas permeable-liquid impermeable heat exchange and delivery hose

DOEpatents

Hall, M.N.

1996-04-30

Life support apparatus is composed of: a garment for completely enclosing a wearer and constructed for preventing passage of gas from the environment surrounding the garment; a portable receptacle holding a quantity of an oxygen-containing fluid in liquid state, the fluid being in a breathable gaseous state when at standard temperature and pressure; a fluid flow member secured within the garment and coupled to the receptacle for conducting the fluid in liquid state from the receptacle to the interior of the garment; and a fluid flow control device connected for causing fluid to flow from the receptacle to the fluid flow member at a rate determined by the breathable air requirement of the wearer, wherein fluid in liquid state is conducted into the interior of the garment at a rate to be vaporized and heated to a breathable temperature by body heat produced by the wearer. 6 figs.

Removal of metabolic heat from man working in a protective suit

NASA Technical Reports Server (NTRS)

Shitzer, A.; Chato, J. C.; Hertig, B. A.

1972-01-01

A water cooled garment was constructed and used to study the characteristics of independent regional cooling of the body in contrast to the current practice of uniform cooling. The cooling pads in the garment were grouped to provide independent control of water inlet temperatures and flow rates to six regions: head, upper torso, lower torso, arms, thighs, and lower legs. Experiments with and without the cooling suit were conducted with five test subjects standing and walking on a treadmill on selected schedules. Steady state and, to a lesser extent, transient characteristics were obtained.

Experimentally Determined Overall Heat Transfer Coefficients for Spacesuit Liquid Cooled Garments

NASA Technical Reports Server (NTRS)

Bue, Grant; Rhodes, Richard; Anchondo, Ian; Westheimer, David; Campbell, Colin; Vogel, Matt; Vonaue, Walt; Conger, Bruce; Stein, James

2015-01-01

A Human-In-The-Loop (HITL) Portable Life Support System 2.0 (PLSS 2.0) test has been conducted at NASA Johnson Space Center in the PLSS Development Laboratory from October 27, 2014 to December 19, 2014. These closed-loop tests of the PLSS 2.0 system integrated with human subjects in the Mark III Suit at 3.7 psi to 4.3 psi above ambient pressure performing treadmill exercise at various metabolic rates from standing rest to 3000 BTU/hr (880 W). The bulk of the PLSS 2.0 was at ambient pressure but effluent water vapor from the Spacesuit Water Membrane Evaporator (SWME) and the Auxiliary Membrane Evaporator (Mini-ME), and effluent carbon dioxide from the Rapid Cycle Amine (RCA) were ported to vacuum to test performance of these components in flight-like conditions. One of the objectives of this test was to determine the overall heat transfer coefficient (UA) of the Liquid Cooling Garment (LCG). The UA, an important factor for modeling the heat rejection of an LCG, was determined in a variety of conditions by varying inlet water temperature, flow rate, and metabolic rate. Three LCG configurations were tested: the Extravehicular Mobility Unit (EMU) LCG, the Oceaneering Space Systems (OSS) LCG, and the OSS auxiliary LCG. Other factors influencing accurate UA determination, such as overall heat balance, LCG fit, and the skin temperature measurement, will also be discussed.

Experimentally Determined Heat Transfer Coefficients for Spacesuit Liquid Cooled Garments

NASA Technical Reports Server (NTRS)

Bue, Grant; Watts, Carly; Rhodes, Richard; Anchondo, Ian; Westheimer, David; Campbell, Colin; Vonau, Walt; Vogel, Matt; Conger, Bruce

2015-01-01

A Human-In-The-Loop (HITL) Portable Life Support System 2.0 (PLSS 2.0) test has been conducted at NASA Johnson Space Center in the PLSS Development Laboratory from October 27, 2014 to December 19, 2014. These closed-loop tests of the PLSS 2.0 system integrated with human subjects in the Mark III Suit at 3.7 psi to 4.3 psi above ambient pressure performing treadmill exercise at various metabolic rates from standing rest to 3000 BTU/hr (880 W). The bulk of the PLSS 2.0 was at ambient pressure but effluent water vapor from the Spacesuit Water Membrane Evaporator (SWME) and the Auxiliary Membrane Evaporator (Mini-ME), and effluent carbon dioxide from the Rapid Cycle Amine (RCA) were ported to vacuum to test performance of these components in flight-like conditions. One of the objectives of this test was to determine the heat transfer coefficient (UA) of the Liquid Cooling Garment (LCG). The UA, an important factor for modeling the heat rejection of an LCG, was determined in a variety of conditions by varying inlet water temperature, flowrate, and metabolic rate. Three LCG configurations were tested: the Extravehicular Mobility Unit (EMU) LCG, the Oceaneering Space Systems (OSS) LCG, and the OSS auxiliary LCG. Other factors influencing accurate UA determination, such as overall heat balance, LCG fit, and the skin temperature measurement, will also be discussed.

Lox breathing system with gas permeable-liquid impermeable heat exchange and delivery hose

DOEpatents

Hall, Mark N.

1996-01-01

Life support apparatus composed of: a garment (2): for completely enclosing a wearer and constructed for preventing passage of gas from the environment surrounding the garment (2); a portable receptacle (6) holding a quantity of an oxygen-containing fluid in liquid state, the fluid being in a breathable gaseous; state when at standard temperature and pressure; a fluid flow member (16) secured within the garment (2) and coupled to the receptacle (6) for conducting the fluid in liquid state from the receptacle (6) to the interior of the garment (2); and a fluid flow control device (14) connected for causing fluid to flow from the receptacle (6) to the fluid flow member (16) at a rate determined by the breathable air requirement of the wearer, wherein fluid in liquid state is conducted into the interior of the garment (2) at a rate to be vaporized and heated to a breathable temperature by body heat produced by the wearer.

SIMULATION OF A BIOFEEDBACK MICROCLIMATE COOLING SYSTEM USING A HUMAN THERMOREGULATION MODEL

DTIC Science & Technology

2017-02-01

garment (LCG) The rate of LCG heat removal from the human body depends on coolant inlet temperature (Tin), clothing insulation worn over the LCG, flow...The efficiency η is equal to one when the outer clothing has sufficient insulation and the heat exchange between LCG and the external environment...0.27 m2·ºC·W-1 (1.73 clo). Insulation of protective ensembles prevent the LCG from absorbing heat from the environment (circulating liquid temperature

Ice pack heat sink subsystem - Phase 1, Volume 1

NASA Technical Reports Server (NTRS)

Roebelen, G. J., Jr.

1973-01-01

The design, development, fabrication, and test at one-g of a functional laboratory model (non-flight) ice pack heat sink subsystem to be used eventually for astronaut cooling during manned space missions are discussed. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick connect/disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

Biomedical Application of Aerospace Personal Cooling Systems

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Webbon, Bruce W.; Kliss, Mark (Technical Monitor)

1997-01-01

Personal thermoregulatory systems which are used by astronauts to alleviate thermal stress during extravehicular activity have been applied to the therapeutic management of multiple sclerosis. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive and two active cooling vests and to measure the body temperature and circulatory changes produced by each cooling vest configuration. The MicroClimate Systems and the Life Enhancement Tech(LET) lightweight liquid cooling vests, the Steele Vest and LET's Zipper Front Garment were used to cool the chest region of 10 male and female subjects (25 to 55 yr.) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approx.22C), were tested for 60 min. with the cooling system operated at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. In general, the male and female subjects' oral and ear temperature responses to cooling were similar for all vest configurations tested. Oral temperatures during the recovery period were significantly (P<0.05) lower than during the control period, approx. 0.2 - 0.5C, for both men and women wearing any of the four different garments. The corresponding ear temperatures were significantly (P<0.05) decreased approx.0.2 - 0.4C by the end of the recovery period. Compared to the control period, no significant differences were found in rectal temperatures during cooling and recovery periods.

Thermal Performance Testing of EMU and OSS Liquid Cooling Garments

NASA Technical Reports Server (NTRS)

Rhodes, Richard; Bue, Grant; Hakam, Mary

2012-01-01

A test was conducted to evaluate three factors influencing the thermal performance of liquid cooling garments (LCG): (1) the comparable thermal performance of an Oceaneering developed engineering evaluation unit (EEU) prototype LDG, (2) the effect of the thermal comfort undergarment (TCU), and (3) the performance of a torso or upper body only LCG configuration. To evaluate the thermal performance of each configuration a metabolic test was conducted, utilizing suited subjects to generate the metabolic heat. For this study three (3) test subjects of similar health and weight produced a metabolic load on the LDG configuration by either resting (300-600 BTU/hr), walking at a slow pace (1200 BRU/hr), and walking at a brisk pace (2200 BTU/hr), as outlined in Figure 1, the metabolic profile. During the test, oxygen consumption, heart rate, relative humidity, air flow, inlet and outlet air pressure, inlet and outlet air temperature, delta air temperature, water flow (100 lb/hr), inlet water temperature (64 F), delta water temperature, water pressure, core body temperature, skin temperature, and sweat loss data was recorded. Four different test configurations were tested, with one configuration tested twice, as outlined in Table 1. The test was conducted with the suit subjects wearing the Demonstrator Suit, pressurized to vent pressure (approximately 0.5 psig). The demonstrator suit has an integrated ventilation duct system and was used to create a relevant environment with a captured ventilation return, an integrated vent tree, and thermal insulation from the environment.

Advanced worker protection system. Topical report, Phase I

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

Myers, J.

1995-07-01

The Department of Energy (DOE) is in the process of defining the magnitude and diversity of Decontamination and Decommissioning (D&D) obligations at its numerous sites. The DOE believes that existing technologies are inadequate to solve many challenging problems such as how to decontaminate structures and equipment cost effectively, what to do with materials and wastes generated, and how to adequately protect workers and the environment. Preliminary estimates show a tremendous need for effective use of resources over a relatively long period (over 30 years). Several technologies are being investigated which can potentially reduce D&D costs while providing appropriate protection tomore » DOE workers. The DOE recognizes that traditional methods used by the EPA in hazardous waste site clean up activities are insufficient to provide the needed protection and worker productivity demanded by DOE D&D programs. As a consequence, new clothing and equipment which can adequately protect workers while providing increases in worker productivity are being sought for implementation at DOE sites. This project will result in the development of an Advanced Worker Protection System (AWPS). The AWPS will be built around a life support backpack that uses liquid air to provide cooling as well as breathing gas to the worker. The backpack will be combined with advanced protective garments, advanced liquid cooling garment, respirator, communications, and support equipment to provide improved worker protection, simplified system, maintenance, and dramatically improve worker productivity through longer duration work cycles.« less

A Thermal Physiological Comparison of Two HazMat Protective Ensembles With and Without Active Convective Cooling

NASA Technical Reports Server (NTRS)

Williamson, Rebecca; Carbo, Jorge; Luna, Bernadette; Webbon, Bruce W.

1998-01-01

Wearing impermeable garments for hazardous materials clean up can often present a health and safety problem for the wearer. Even short duration clean up activities can produce heat stress injuries in hazardous materials workers. It was hypothesized that an internal cooling system might increase worker productivity and decrease likelihood of heat stress injuries in typical HazMat operations. Two HazMat protective ensembles were compared during treadmill exercise. The different ensembles were created using two different suits: a Trelleborg VPS suit representative of current HazMat suits and a prototype suit developed by NASA engineers. The two life support systems used were a current technology Interspiro Spirolite breathing apparatus and a liquid air breathing system that also provided convective cooling. Twelve local members of a HazMat team served as test subjects. They were fully instrumented to allow a complete physiological comparison of their thermal responses to the different ensembles. Results showed that cooling from the liquid air system significantly decreased thermal stress. The results of the subjective evaluations of new design features in the prototype suit were also highly favorable. Incorporation of these new design features could lead to significant operational advantages in the future.

Personal cooling in nuclear power stations. Final report

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

Kamon, E.

1983-03-01

Two approaches to personal, non-restrictive cooling of workers exposed to high-temperature work environments in nuclear power plants were evaluated. Both approaches involved a cooling garment designed to be worn under the protective clothing donned in penetration into radiation areas. One garmet was developed to cool by direct body contact with small packets of frozen water enclosed in the pockets of a shirt. The other garmets cooled by circulating a cooled liquid through capillaries in a vest and head cap (System A) or a vest (System B). Testing was conducted in a laboratory simulation of high ambient temperature (55/sup 0/C) andmore » moderate metabolic heat production (200 to 300 kcal/h). Exposure time without cooling (control) was 52 minutes (Group 1) for the workloads demanding 200 kcal/h (48 minutes for Group 2). A long garmet with 7.2 kg of frozen water (LFWG) increased mean exposure time over the control by 242% (163% for the same garmet with 6.2 kg of frozen water). A short-version garmet with 3.8 kg of frozen water (SFWG) increased the stay time by 115%. The circulating-liquid garmets increased mean exposure time 35% (System A) and 27% (System B) over the control. In field observation, the LFWG with 6.2 kg of frozen water improved stay time by 125%.« less

Evaporative Cooling and Dehumidification Garment for Portable Life Support Systems

NASA Technical Reports Server (NTRS)

Izenson, Michael; Chen, Weibo; Bue, Grant

2013-01-01

This paper describes the design and development of an innovative thermal and humidity control system for future space suits. The system comprises an evaporation cooling and dehumidification garment (ECDG) and a lithium chloride absorber radiator (LCAR). The ECDG absorbs heat and water vapor from inside the suit pressure garment, while the LCAR rejects heat to space without venting water vapor. The ECDG is built from thin, flexible patches with coversheets made of non-porous, water-permeable membranes that -enclose arrays of vapor flow passages. Water vapor from inside the spacesuit diffuses across the water permeable membranes, enters the vapor flow channels, and then flows to the LCAR, thus dehumidifying the internal volume of the space suit pressure garment. Additional water evaporation inside the ECDG provides cooling for sensible heat loads. -The heat released from condensation and absorption in the LCAR is rejected to the environment by thermal radiation. We have assembled lightweight and flexible ECDG pouches from prototypical materials and measured their performance in a series of separate effects tests under well-controlled, prototypical conditions. Sweating hot plate tests at typical space suit pressures show that ECDG pouches can absorb over 60 W/ft of latent heat and 20 W/ft of sensible heat from the pressure garment environment. These results are in good agreement with the predictions of our analysis models.

You can't eat moon rocks. [aerospace technology spinoffs assessment

NASA Technical Reports Server (NTRS)

Kubokawa, C. C.

1976-01-01

The effects produced by the aerospace program are investigated. The technology developed from aerospace-related research, development, and manufacturing has been made available to the public for its use through the NASA Technology Utilization Program. A description is presented of 'spinoffs' of NASA's aerospace programs which are used on a daily basis by the public. Attention is given to the liquid cooled garment technology, meal systems for the elderly, the zinc-rich coating, the emergency blanket, the flexible urethane foam Temper Foam, the 'Fog-Away Coating', and composite graphite equipment.

Biomedical technical transfer. Applications of NASA science and technology

NASA Technical Reports Server (NTRS)

1976-01-01

Lower body negative pressure testing in cardiac patients has been completed as well as the design and construction of a new leg negative unit for evaluating heart patients. This technology is based on NASA research, using vacuum chambers to stress the cardiovascular system during space flight. Additional laboratory tests of an intracranial pressure transducer, have been conducted. Three new biomedical problems to which NASA technology is applicable are also identified. These are: a communication device for the speech impaired, the NASA development liquid-cooled garment, and miniature force transducers for heart research.

ADVANCED WORKER PROTECTION SYSTEM

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

Judson Hedgehock

2001-03-16

From 1993 to 2000, OSS worked under a cost share contract from the Department of Energy (DOE) to develop an Advanced Worker Protection System (AWPS). The AWPS is a protective ensemble that provides the user with both breathing air and cooling for a NIOSH-rated duration of two hours. The ensemble consists of a liquid air based backpack, a Liquid Cooling Garment (LCG), and an outer protective garment. The AWPS project was divided into two phases. During Phase 1, OSS developed and tested a full-scale prototype AWPS. The testing showed that workers using the AWPS could work twice as long asmore » workers using a standard SCBA. The testing also provided performance data on the AWPS in different environments that was used during Phase 2 to optimize the design. During Phase 1, OSS also performed a life-cycle cost analysis on a representative clean up effort. The analysis indicated that the AWPS could save the DOE millions of dollars on D and D activities and improve the health and safety of their workers. During Phase 2, OSS worked to optimize the AWPS design to increase system reliability, to improve system performance and comfort, and to reduce the backpack weight and manufacturing costs. To support this design effort, OSS developed and tested several different generations of prototype units. Two separate successful evaluations of the ensemble were performed by the International Union of Operation Engineers (IUOE). The results of these evaluations were used to drive the design. During Phase 2, OSS also pursued certifying the AWPS with the applicable government agencies. The initial intent during Phase 2 was to finalize the design and then to certify the system. OSS and Scott Health and Safety Products teamed to optimize the AWPS design and then certify the system with the National Institute of Occupational Health and Safety (NIOSH). Unfortunately, technical and programmatic difficulties prevented us from obtaining NIOSH certification. Despite the inability of NIOSH to certify the design, OSS was able to develop and successfully test, in both the lab and in the field, a prototype AWPS. They clearly demonstrated that a system which provides cooling can significantly increase worker productivity by extending the time they can function in a protective garment. They were also able to develop mature outer garment and LCG designs that provide considerable benefits over current protective equipment, such as self donning and doffing, better visibility, and machine washable. A thorough discussion of the activities performed during Phase 1 and Phase 2 is presented in the AWPS Final Report. The report also describes the current system design, outlines the steps needed to certify the AWPS, discusses the technical and programmatic issues that prevented the system from being certified, and presents conclusions and recommendations based upon the seven year effort.« less

Liquid-circulating garment controls thermal balance

NASA Technical Reports Server (NTRS)

Kuznetz, L. H.

1977-01-01

Experimental data and mathematical model of human thermoregulatory system have been used to investigate use of liquid-circulatory garment (LCG) to control thermal balance. Model proved useful as accurate simulator of such variables as sweat rate, skin temperature, core temperature, and radiative, evaporative, and LCG heat loss.

A simple theoretical model of heat and moisture transport in multi-layer garments in cool ambient air.

PubMed

Wissler, Eugene H; Havenith, George

2009-03-01

Overall resistances for heat and vapor transport in a multilayer garment depend on the properties of individual layers and the thickness of any air space between layers. Under uncomplicated, steady-state conditions, thermal and mass fluxes are uniform within the garment, and the rate of transport is simply computed as the overall temperature or water concentration difference divided by the appropriate resistance. However, that simple computation is not valid under cool ambient conditions when the vapor permeability of the garment is low, and condensation occurs within the garment. Several recent studies have measured heat and vapor transport when condensation occurs within the garment (Richards et al. in Report on Project ThermProject, Contract No. G6RD-CT-2002-00846, 2002; Havenith et al. in J Appl Physiol 104:142-149, 2008). In addition to measuring cooling rates for ensembles when the skin was either wet or dry, both studies employed a flat-plate apparatus to measure resistances of individual layers. Those data provide information required to define the properties of an ensemble in terms of its individual layers. We have extended the work of previous investigators by developing a rather simple technique for analyzing heat and water vapor transport when condensation occurs within a garment. Computed results agree well with experimental results reported by Richards et al. (Report on Project ThermProject, Contract No. G6RD-CT-2002-00846, 2002) and Havenith et al. (J Appl Physiol 104:142-149, 2008). We discuss application of the method to human subjects for whom the rate of sweat secretion, instead of the partial pressure of water on the skin, is specified. Analysis of a more complicated five-layer system studied by Yoo and Kim (Text Res J 78:189-197, 2008) required an iterative computation based on principles defined in this paper.

Operational Characteristics of Four Commercially Available Personal Cooling Vests

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Lee, Hank C.; Webbon, Bruce W.; Kliss, Mark (Technical Monitor)

1997-01-01

Personal thermoregulatory systems which provide chest cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive and two active cooling vests, and to measure the body temperature and circulatory changes produced by each cooling vest configuration. The MicroClimate Systems and the Life Enhancement Tech(LET) lightweight liquid cooling vests, the Steele Vest and LET's Zipper Front Garment were used to cool the chest region of 11 male and 10 female subjects (25 to 55 yr.) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approx.21 C), were tested for 60 min. with the cooling system operated at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a URI Inc. Biolog ambulatory monitor. In general, the male and female subjects' rectal and ear temperature responses to cooling were similar for all vest configurations tested. Oral temperatures during the recovery period were significantly (P<0.05) lower than during the control period, approx.0.2 - 0.5 C, for both men and women wearing any of the four different garments. The corresponding car temperatures were significantly (P<0.05) decreased approx.0.2 - 0.3 C by the end of the recovery period. Compared to the control period, no significant differences were found in rectal temperatures during cooling and recovery periods. These results show that all vest configurations elicit a similar thermal response in both male and female subject groups. However, subject population variance was rather large and may have masked differences between the vests. One vest may prove more effective than another for a given individual, and experience is the only means of determining this.

Ice pack heat sink subsystem, phase 2. [astronaut life support cooling system

NASA Technical Reports Server (NTRS)

Roebelen, G. J., Jr.; Kellner, J. D.

1975-01-01

The report describes the design, development, fabrication, and test at one gravity of a prototype ice pack heat sink subsystem to be used eventually for astronaut cooling during manned space missions; the investigation of thermal storage material with the objective of uncovering materials with heats of fusion and/or solution in the range of 300 Btu/lb (700 kilojoules/kilogram); and the planned procedure for implementing an ice pack heat sink subsystem flight experiment. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

Risk of Orthostatic Intolerance During Re-Exposure to Gravity

NASA Technical Reports Server (NTRS)

Platts, Steven; Stenger, Michael B.; Lee, Stuart M. C.; Westby, Christian M.; Phillips, Tiffany R.; Arzeno, Natalia M.; Johnston, Smith; Mulugeta, Lealem

2015-01-01

Post-spaceflight orthostatic intolerance remains a significant concern to NASA. In Space Shuttle missions, astronauts wore anti-gravity suits and liquid cooling garments to protect against orthostatic intolerance during re-entry and landing, but in-flight exercise and the end-of-mission fluid loading failed to protect approximately 30% of Shuttle astronauts when these garments were not worn. The severity of the problem appears to be increased after long-duration space flight. Five of six US astronauts could not complete a 10-minutes upright-posture tilt testing on landing day following 4-5 month stays aboard the Mir space station. The majority of these astronauts had experienced no problems of orthostatic intolerance following their shorter Shuttle flights. More recently, four of six US astronauts could not complete a tilt test on landing day following approximately 6 month stays on the International Space Station. Similar observations were made in the Soviet and Russian space programs, such that some cosmonauts wear the Russian compression garments (Kentavr) up to 4 days after landing. Future exploration missions, such as those to Mars or Near Earth Objects, will be long duration, and astronauts will be landing on planetary bodies with no ground-support teams. The occurrence of severe orthostatic hypotension could threaten the astronauts' health and safety and success of the mission.

Exit Presentation

NASA Technical Reports Server (NTRS)

Melone, Kate

2016-01-01

Skills Acquired: Tensile Testing: Prepare materials and setting up the tensile tests; Collect and interpret (messy) data. Outgassing Testing: Understand TML (Total Mass Loss) and CVCM (Collected Volatile Condensable Material); Collaboration with other NASA centers. Z2 (NASA's Prototype Space Suit Development) Support: Hands on building mockups of components; Analyze data; Work with others, understanding what both parties need in order to make a run successful. LCVG (Liquid Cooling and Ventilation Garment) Flush and Purge Console: Both formal design and design review process; How to determine which components to use - flow calculations, pressure ratings, size, etc.; Hazard Analysis; How to make design tradeoffs.

ASDA - Advanced Suit Design Analyzer computer program

NASA Technical Reports Server (NTRS)

Bue, Grant C.; Conger, Bruce C.; Iovine, John V.; Chang, Chi-Min

1992-01-01

An ASDA model developed to evaluate the heat and mass transfer characteristics of advanced pressurized suit design concepts for low pressure or vacuum planetary applications is presented. The model is based on a generalized 3-layer suit that uses the Systems Integrated Numerical Differencing Analyzer '85 in conjunction with a 41-node FORTRAN routine. The latter simulates the transient heat transfer and respiratory processes of a human body in a suited environment. The user options for the suit encompass a liquid cooled garment, a removable jacket, a CO2/H2O permeable layer, and a phase change layer.

Gearing Up for the Big Game...and More

NASA Technical Reports Server (NTRS)

2004-01-01

Bill Elkins, a member of the U.S. Space Foundation's Space Technology Hall of Fame, is using his experience in developing cooling garments for use in sports and medicine. His company, CoolSystems, has developed the Game Ready[TM] Accelerated Recovery System. Game Ready[TM] ergonomic wraps are designed to custom fit the ankle, knee, back, torso, shoulder, elbow, and wrist and provide deep tissue cooling therapy with intermittent compression to reduce pain, swelling, and tissue damage. Recharge[TM] cooling garments have been developed to lower core body temperature in people with heat-sensitive multiple sclerosis, reducing symptoms such as fatigue, decreased balance, impaired vision, and decreased endurance. The company currently is collaborating with Stanford University Medical Center's Stanford Stroke Center to investigate the effectiveness of discrete hypothermia in stroke and head trauma patients.

Article comprising a garment or other textile structure for use in controlling body temperature

DOEpatents

Butzer, Melissa J.

2000-01-01

There is disclosed an article for use in cooling body temperature which comprises a garment having a coat and pant, with each having a body section adapted to receive a portion of the torso of the wearer and extensions from the body section to receive the wearer's limbs. The garment includes a system for circulating temperature controlling fluid from a suitable source through patches removably received in pockets in each of body section and extensions.

Operational Characteristics of Two Commercially Available Personal Cooling Vests

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Webbon, Bruce W.; Luna, Bernadette (Technical Monitor)

1996-01-01

Personal thermoregulatory systems which provide chest cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive cooling vests, and to measure the body temperature and circulatory changes produced by each cooling vest configuration. A Life Enhancement Technologies, (LET) ice vest garment and a Steele, Inc. vest were used to cool the chest region of 11 male subjects (25 to 55 yr) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approximately 21 C) were tested for 60 min. with the cooling system operating at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. No significant differences were found in either the oral or ear temperature responses to the two vests. However, the rectal and mean skin temperatures at the end of the cooling period were both significantly lower (P less than 0.05), approximately 0.2 and 1.9 C, respectively for the LET vest than for the Steele garment. These data show that different vest configurations may produce different thermal responses in healthy male subjects which should be considered in the use of these cooling garments.

Integration methods for thermosensitive gel systems in garments

NASA Astrophysics Data System (ADS)

Reich, A.; Rödel, H.; Stoll, A.; Liske, A.; Zehm, D.

2017-10-01

Humans live and work under severe thermophysiological conditions, which are characterized by extreme temperatures and humidities. Furthermore, additional burdens can arise from physical activities of the human body or the work conditions (resulting in psychological stress) [1]. The thermoregulation of the human body compensates such situations and maintains the core body temperature at 37°C (98,6 °F). The currently used systems for supporting human thermoregulation, such as PCM-equipped surface structures or mobile water-based cooling units have the disadvantage that the running cooling process is neither switchable nor reversible. Another promising possibility for a personal cooling is the use of temperature-dependent superabsorbers (so-called LCST and UCST) in garments, which absorb the human sweat and transmit it to the environment by evaporation. Cooling during evaporation results in heat transfer from the human body.

Cooling vest

NASA Technical Reports Server (NTRS)

Kosmo, J.; Kane, J.; Coverdale, J.

1977-01-01

Inexpensive vest of heat-sealable urethane material, when strapped to person's body, presents significant uncomplicated cooling system for environments where heavy accumulation of metabolic heat exists. Garment is applicable to occupations where physical exertion is required under heavy protective clothing.

Next-Generation Evaporative Cooling Systems for the Advanced Extravehicular Mobility Unit Portable Life Support System

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Anchondo, Ian; Bue, Grant C.; Campbell, Colin; Colunga, Aaron

2012-01-01

The development of the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is currently underway at NASA Johnson Space Center. The AEMU PLSS features two new evaporative cooling systems, the Reduced Volume Prototype Spacesuit Water Membrane Evaporator (RVP SWME), and the Auxiliary Cooling Loop (ACL). The RVP SWME is the third generation of hollow fiber SWME hardware, and like its predecessors, RVP SWME provides nominal crewmember and electronics cooling by flowing water through porous hollow fibers. Water vapor escapes through the hollow fiber pores, thereby cooling the liquid water that remains inside of the fibers. This cooled water is then recirculated to remove heat from the crewmember and PLSS electronics. Major design improvements, including a 36% reduction in volume, reduced weight, and more flight like back-pressure valve, facilitate the packaging of RVP SWME in the AEMU PLSS envelope. In addition to the RVP SWME, the Auxiliary Cooling Loop (ACL), was developed for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feed-water assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the RVP SWME, but is only 25% of the size of RVP SWME, providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a SOV reduction in size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The development of these evaporative cooling systems will contribute to a more robust and comprehensive AEMU PLSS.

Apollo experience report: Assessment of metabolic expenditures. [extravehicular activity

NASA Technical Reports Server (NTRS)

Waligora, J. M.; Hawkins, W. R.; Humbert, G. F.; Nelson, L. J.; Vogel, S. J.; Kuznetz, L. H.

1975-01-01

A significant effort was made to assess the metabolic expenditure for extravehicular activity on the lunar surface. After evaluation of the real-time data available to the flight controller during extravehicular activity, three independent methods of metabolic assessment were chosen based on the relationship between heart rate and metabolic production, between oxygen consumption and metabolic production, and between the thermodynamics of the liquid-cooled garment and metabolic production. The metabolic assessment procedure is analyzed and discussed. Real-time use of this information by the Apollo flight surgeon is discussed. Results and analyses of the Apollo missions and comments concerning future applications are included.

STS-57 MS2 Sherlock dons EMU upper torso with technicians' help at JSC's WETF

NASA Technical Reports Server (NTRS)

1992-01-01

STS-57 Mission Specialist 2 (MS2) Nancy J. Sherlock, wearing the liquid cooling and ventilation garment (LCVG) and an extravehicular mobility unit (EMU) lower torso, squats under the EMU upper torso and prepares to raise her arms into the sleeves. Technicians stand on either side of Sherlock and are ready to assist her in donning the upper torso. When fully suited the platform Sherlock is on will be lowered into the 25 foot deep pool located in JSC's Weightless Environment Training Facility (WETF) Bldg 29. During the underwater simulation, Sherlock will practice extravehicular activity (EVA) procedures.

Finger heat flux/temperature as an indicator of thermal imbalance with application for extravehicular activity.

PubMed

Koscheyev, Victor S; Leon, Gloria R; Coca, Aitor

2005-11-01

The designation of a simple, non-invasive, and highly precise method to monitor the thermal status of astronauts is important to enhance safety during extravehicular activities (EVA) and onboard emergencies. Finger temperature (Tfing), finger heat flux, and indices of core temperature (Tc) [rectal (Tre), ear canal (Tec)] were assessed in 3 studies involving different patterns of heat removal/insertion from/to the body by a multi-compartment liquid cooling/warming garment (LCWG). Under both uniform and nonuniform temperature conditions on the body surface, Tfing and finger heat flux were highly correlated with garment heat flux, and also highly correlated with each other. Tc responses did not adequately reflect changes in thermal balance during the ongoing process of heat insertion/removal from the body. Overall, Tfing/finger heat flux adequately reflected the initial destabilization of thermal balance, and therefore appears to have significant potential as a useful index for monitoring and maintaining thermal balance and comfort in extreme conditions in space as well as on Earth. c2005 Elsevier Ltd. All rights reserved.

Superficial cooling does not decrease core body temperature before, during, or after exercise in an American football uniform.

PubMed

Lopez, Rebecca M; Eberman, Lindsey E; Cleary, Michelle A

2012-12-01

The purpose of this study was to identify the effects of superficial cooling on thermoregulatory responses while exercising in a hot humid environment while wearing an American football uniform. Nine male and female subjects wore a superficial cooling garment while in a cooling (CS) experimental condition or a no cooling (NCS) control condition during an exercise task consisting of warm-up (WU), exercise (EX), and recovery (R). The exercise task simulated an American football conditioning session with subjects wearing a full American football uniform and performing anaerobic and aerobic exercises in a hot humid environment. Subjects were allowed to drink water ad libitum during rest breaks. During the WU, EX, and R periods, core body temperature (T(c)) was measured to assess the effect of the cooling garment. Neither baseline resting before warm-up T(c) nor after warm-up T(c) was significantly different between trials. No significant differences in exercise T(c) between conditions were found. Time to return to baseline T(c) revealed no significant differences between the experimental and control conditions. The authors found that the volume of fluid consumed was 34% less in the experimental condition (711.1 ± 188.0 ml) compared with the control condition (1,077.8 ± 204.8 ml). The findings indicate that the cooling garment was not effective in blunting the rise in T(c) during warm-up, attenuating a rise in T(c) during intermittent exercise, or in increasing a return to baseline T(c) during a resting recovery period in a hot humid environment while wearing an American football uniform.

Development of an advanced rocket propellant handler's suit.

PubMed

Doerr, D F

2001-01-01

Most launch vehicles and satellites in the US inventory rely upon the use of hypergolic rocket propellants, many of which are toxic to humans. These fuels and oxidizers, such as hydrazine and nitrogen tetroxide have threshold limit values as low as 0.01 PPM. It is essential to provide space workers handling these agents whole body protection as they are universally hazardous not only to the respiratory system, but the skin as well. This paper describes a new method for powering a whole body protective garment to assure the safety of ground servicing crews. A new technology has been developed through the small business innovative research program at the Kennedy Space Center. Currently, liquid air is used in the environmental control unit (ECU) that powers the propellant handlers suit (PHE). However, liquid air exhibits problems with attitude dependence, oxygen enrichment, and difficulty with reliable quantity measurement. The new technology employs the storage of the supply air as a supercritical gas. This method of air storage overcomes all of three problems above while maintaining high density storage at relatively low vessel pressures (<7000 kPa or approximately 1000 psi). A one hour prototype ECU was developed and tested to prove the feasibility of this concept. This was upgraded by the design of a larger supercritical dewar capable of holding 7 Kg of air, a supply which provides a 2 hour duration to the PHE. A third version is being developed to test the feasibility of replacing existing air cooling methodology with a liquid cooled garment for relief of heat stress in this warm Florida environment. Testing of the first one hour prototype yielded data comparable to the liquid air powered predecessor, but enjoyed advantages of attitude independence and oxygen level stability. Thermal data revealed heat stress relief at least as good as liquid air supplied units. The application of supercritical air technology to this whole body protective ensemble marked an advancement in the state-of-the-art in personal protective equipment. Not only was long duration environmental control provided, but it was done without a high pressure vessel. The unit met human performance needs for attitude independence, oxygen stability and relief of heat stress. This supercritical air (and oxygen) technology is suggested for microgravity applications in life support such as the Extravehicular Mobility Unit. c 2001. Elsevier Science Ltd. All rights reserved.

Development of an advanced rocket propellant handler's suit

NASA Technical Reports Server (NTRS)

Doerr, D. F.

2001-01-01

Most launch vehicles and satellites in the US inventory rely upon the use of hypergolic rocket propellants, many of which are toxic to humans. These fuels and oxidizers, such as hydrazine and nitrogen tetroxide have threshold limit values as low as 0.01 PPM. It is essential to provide space workers handling these agents whole body protection as they are universally hazardous not only to the respiratory system, but the skin as well. This paper describes a new method for powering a whole body protective garment to assure the safety of ground servicing crews. A new technology has been developed through the small business innovative research program at the Kennedy Space Center. Currently, liquid air is used in the environmental control unit (ECU) that powers the propellant handlers suit (PHE). However, liquid air exhibits problems with attitude dependence, oxygen enrichment, and difficulty with reliable quantity measurement. The new technology employs the storage of the supply air as a supercritical gas. This method of air storage overcomes all of three problems above while maintaining high density storage at relatively low vessel pressures (<7000 kPa or approximately 1000 psi). A one hour prototype ECU was developed and tested to prove the feasibility of this concept. This was upgraded by the design of a larger supercritical dewar capable of holding 7 Kg of air, a supply which provides a 2 hour duration to the PHE. A third version is being developed to test the feasibility of replacing existing air cooling methodology with a liquid cooled garment for relief of heat stress in this warm Florida environment. Testing of the first one hour prototype yielded data comparable to the liquid air powered predecessor, but enjoyed advantages of attitude independence and oxygen level stability. Thermal data revealed heat stress relief at least as good as liquid air supplied units. The application of supercritical air technology to this whole body protective ensemble marked an advancement in the state-of-the-art in personal protective equipment. Not only was long duration environmental control provided, but it was done without a high pressure vessel. The unit met human performance needs for attitude independence, oxygen stability and relief of heat stress. This supercritical air (and oxygen) technology is suggested for microgravity applications in life support such as the Extravehicular Mobility Unit. c 2001. Elsevier Science Ltd. All rights reserved.

Development of an advanced rocket propellant handler's suit

NASA Astrophysics Data System (ADS)

Doerr, DonaldF.

2001-08-01

Most launch vehicles and satellites in the US inventory rely upon the use of hypergolic rocket propellants, many of which are toxic to humans. These fuels and oxidizers, such as hydrazine and nitrogen tetroxide have threshold limit values as low as 0.01 PPM. It is essential to provide space workers handling these agents whole body protection as they are universally hazardous not only to the respiratory system, but the skin as well. This paper describes a new method for powering a whole body protective garment to assure the safety of ground servicing crews. A new technology has been developed through the small business innovative research program at the Kennedy Space Center. Currently, liquid air is used in the environmental control unit (ECU) that powers the propellant handlers suit (PHE). However, liquid air exhibits problems with attitude dependence, oxygen enrichment, and difficulty with reliable quantity measurement. The new technology employs the storage of the supply air as a supercritical gas. This method of air storage overcomes all of three problems above while maintaining high density storage at relatively low vessel pressures (<7000 kPa or ˜1000 psi). A one hour prototype ECU was developed and tested to prove the feasibility of this concept. This was upgraded by the design of a larger supercritical dewar capable of holding 7 Kg of air, a supply which provides a 2 hour duration to the PHE. A third version is being developed to test the feasibility of replacing existing air cooling methodology with a liquid cooled garment for relief of heat stress in this warm Florida environment. Testing of the first one hour prototype yielded data comprobable to the liquid air powered predecessor, but enjoyed advantages of attitude independence and oxygen level stability. Thermal data revealed heat stress relief at least as good as liquid air supplied units. The application of supercritical air technology to this whole body protective ensemble marked an advancement in the state-of-the-art in personal protective equipment. Not only was long duration environmental control provided, but it was done without a high pressure vessel. The unit met human performance needs for attitude independence, oxygen stability, and relief of heat stress. This supercritical air (and oxygen) technology is suggested for microgravity applications in life support such as the Extravehicular Mobility Unit.

Physiologic and thermal responses of male and female patients with multiple sclerosis to head and neck cooling

NASA Technical Reports Server (NTRS)

Ku, Y. T.; Montgomery, L. D.; Wenzel, K. C.; Webbon, B. W.; Burks, J. S.

1999-01-01

Personal cooling systems are used to alleviate symptoms of multiple sclerosis and to prevent increased core temperature during daily activities. The objective of this study was to determine the thermal and physiologic responses of patients with multiple sclerosis to short-term maximal head and neck cooling. A Life Support Systems, Inc. Mark VII portable cooling system and a liquid cooling helmet were used to cool the head and neck regions of 24 female and 26 male patients with multiple sclerosis in this study. The subjects, seated in an upright position at normal room temperature (approximately 22 degrees C), were cooled for 30 min by the liquid cooling garment, which was operated at its maximum cooling capacity. Oral, right, and left ear temperatures and cooling system parameters were logged manually every 5 min. Forearm, calf, chest, and rectal temperatures, heart rate, and respiration rate were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. This protocol was performed during the winter and summer to investigate the seasonal differences in the way patients with multiple sclerosis respond to head and neck cooling. No significant differences were found between the male and female subject group's mean rectal or oral temperature responses during any phase of the experiment. The mean oral temperature decreased significantly (P < 0.05) for both groups approximately 0.3 degrees C after 30 min of cooling and continued to decrease further (approximately 0.1-0.2 degrees C) for a period of approximately 15 min after removal of the cooling helmet. The mean rectal temperatures decreased significantly (P < 0.05) in both male and female subjects in the winter studies (approximately 0.2-0.3 degrees C) and for the male subjects during the summer test (approximately 0.2 degrees C). However, the rectal temperature of the female subjects did not change significantly during any phase of the summer test. These data indicate that head and neck cooling may, in general, be used to reduce the oral and body temperatures of both male and female patients with multiple sclerosis by the approximate amount needed for symptomatic relief as shown by other researchers. However, thermal response of patients with multiple sclerosis may be affected by gender and seasonal factors, which should be considered in the use of liquid cooling therapy.

External Cooling Coupled to Reduced Extremity Pressure Device

NASA Technical Reports Server (NTRS)

Kuznetz, Lawrence H.

2011-01-01

Although suited astronauts are currently cooled with a Liquid Cooled Ventilation Garment (LCVG), which can remove up to 85 percent of body heat, their effectiveness is limited because cooling must penetrate layers of skin, muscle, fat, bone, and tissue to reach the bloodstream, where its effect is prominent. Vasoconstriction further reduces the effectiveness by limiting arterial flow when exposed to cold (the frostbite response), resulting in a time constant on the order of 20 minutes from application to maximum effect. This delay can be crucial in severe exposure to hypo- or hyper-thermic conditions, compromising homeostasis. The purpose of this innovation is to provide a lightweight, effective means of delivering heat or cold from an external source directly to the bloodstream. The effectiveness of this ECCREP (External Cooling Coupled to Reduced Extremity Pressure) device is based on not having to penetrate layers of skin, muscle, fat, and tissue, thereby avoiding the thermal lag associated with their mass and heat capacity. This is accomplished by means of an outer boot operating at a slightly reduced pressure than the rest of the body, combined with an inner boot cooled or heated by an external source via water or chemicals. Heat transfer from the external source to the foot takes place by means of circulating water or flexible heat pipes.

Control of liquid cooling garments: technical control of body heat storage.

PubMed

Hexamer, M; Werner, J

1996-07-01

This paper describes a concept of how liquid cooling garments (LCG) can be automatically controlled by the objective physiological state. The technically controlled parameter was mean body temperature which was calculated from the measured rectal and mean skin temperature. This was motivated by the fact that mean body temperature is the basis for estimating body heat storage, a commonly used measure of thermal strain. Here the setpoint of mean body temperature was the individual value taken in a preceeding resting period and it was the task of the technical controller to keep the actual value of mean body temperature as close as possible to the setpoint. The most important tuning parameters of the controller were the weighting coefficients for rectal and mean skin temperature in the calculation for mean body temperature. The ratio of these two coefficients determined the degree of compensation for any rectal temperature shift by changing mean skin temperature. Test experiments were carried out (n = 5) in which the controller was able to clamp mean body temperature to the setpoint thereby preventing heat storage. Although exercise rate (75 W) was the same, sweating and warm discomfort occurred in some cases due to the individual rectal temperature rise. Another source of discomfort were delays or paradoxical time courses of rectal temperature at the start or end of exercise which were responsible for a delayed onset of cooling or heating. To avoid these effects, the oxygen consumption signal, which is very fast and directly correlated to the exercise rate, was added to the control loop. Each increase of this parameter above its resting level lowered suit temperature. As heat storage should not be completely rejected by this new signal pathway, the controller for mean body temperature still remained active. The repetition of the experiments showed that the load error in the control loop was smaller and the comfort level in transient phases higher. For a further improvement of this concept it is recommended that the weighting coefficients be tuned to the individual requirements.

Non-Venting Thermal and Humidity Control for EVA Suits

NASA Technical Reports Server (NTRS)

Izenson, Mike; Chen, Weibo; Bue, Grant

2011-01-01

Future EVA suits need processes and systems to control internal temperature and humidity without venting water to the environment. This paper describes an absorption-based cooling and dehumidification system as well as laboratory demonstrations of the key processes. There are two main components in the system: an evaporation cooling and dehumidification garment (ECDG) that removes both sensible heat and latent heat from the pressure garment, and an absorber radiator that absorbs moisture and rejects heat to space by thermal radiation. This paper discusses the overall design of both components, and presents recent data demonstrating their operation. We developed a design and fabrication approach to produce prototypical heat/water absorbing elements for the ECDG, and demonstrated by test that these elements could absorb heat and moisture at a high flux. Proof-of-concept tests showed that an ECDG prototype absorbs heat and moisture at a rate of 85 W/ft under conditions that simulate operation in an EVA suit. The heat absorption was primarily due to direct absorption of water vapor. It is possible to construct large, flexible, durable cooling patches that can be incorporated into a cooling garment with this system. The proof-of-concept test data was scaled to calculate area needed for full metabolic loads, thus showing that it is feasible to use this technology in an EVA suit. Full-scale, lightweight absorber/radiator modules have also been built and tested. They can reject heat at a flux of 33 W/ft while maintaining ECDG operation at conditions that will provide a cool and dry environment inside the EVA suit.

Muscle-Cooling Intervention to Reduce Fatigue and Fatigue-Induced Tremor in Novice and Experienced Surgeons: A Preliminary Investigation.

PubMed

Jensen, Lauren; Dancisak, Michael; Korndorffer, James

2016-10-01

A localized, intermittent muscle-cooling protocol was implemented to determine cooling garment efficacy in reducing upper extremity muscular fatigue and tremor in novice ( n  = 10) and experienced surgeons ( n  = 9). Subjects wore a muscle-cooling garment while performing multiple trials of a forearm exercise and paired suturing task to induce muscular fatigue and exercise-induced tremor. A reduction in tremor amplitude and an extension in time to fatigue were expected with muscle cooling as compared with control trials. Each subject completed an intervention session (5°C cooling condition) and a control session (32°C or thermal neutral condition). A paired samples t test indicated that tremor amplitude was significantly reduced ( t [8] = 1.89458; p  < 0.05) in experienced surgeons in two dimensions (up and down, and back and forth). Tremor amplitude was reduced in novice surgeons but the effect was not significant. Time to fatigue and suture time improved in both cohorts with muscle cooling, but the effect did not reach significance. Results from the pilot work suggest muscle cooling as an intervention for reduction of fatigue and tremor is very promising, warranting further investigation. Surgical specialties that require prolonged procedures might benefit more from this intervention.

Physiological Responses to Microclimate Cooling Used By the Air Soldier Dressed at MOPP 4 in an Extreme Desert Condition: Effects of Six Configurations

DTIC Science & Technology

2012-12-01

USARIEM TECHNICAL REPORT PHYSIOLOGICAL RESPONSES TO MICROCLIMATE COOLING USED BY THE AIR SOLDIER DRESSED AT MOPP 4 IN AN...2012 2. REPORT TYPE 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Physiological Responses to Microclimate Cooling Used By the Air Soldier 5b. GRANT... Microclimate Cooling System MCG HI – Air Warrior Microclimate Cooling Garment Used in High Cooling Configuration MCG LO - Air Warrior Microclimate

Long Duration Testing of a Spacesuit Water Membrane Evaporator Prototype

NASA Technical Reports Server (NTRS)

Bue, Grant C.; Makinen, Janice; Cox, Marlon; Watts, Carly; Campbell, Colin; Vogel, Matthew; Colunga, Aaron

2011-01-01

The Spacesuit Water Membrane Evaporator (SWME) is a heat-rejection device that is being developed to perform thermal control for advanced spacesuits. Cooling is achieved by circulating water from the liquid cooling garment (LCG) through hollow fibers (HoFi?s), which are small hydrophobic tubes. Liquid water remains within the hydrophobic tubes, but water vapor is exhausted to space, thereby removing heat. A SWME test article was tested over the course of a year, for a total of 1200 cumulative hours. In order to evaluate SWME tolerance to contamination due to constituents caused by distillation processes, these constituents were allowed to accumulate in the water as evaporation occurred. A test article was tested over the course of a year for a total of 1200 cumulative hours. The heat rejection performance of the SWME degraded significantly--below 700 W, attributable to the accumulation of rust in the circulating loop and biofilm growth. Bubble elimination capability, a feature that was previously proven with SWME, was compromised during the test, most likely due to loss of hydrophobic properties of the hollow fibers. The utilization of water for heat rejection was shown not to be dependent on test article, life cycle, heat rejection rate, or freezing of the membranes.

Long Duration Testing of a Spacesuit Water Membrane Evaporator Prototype

NASA Technical Reports Server (NTRS)

Bue, Grant C.; Makinen, Janice; Cox, Marlon; Watts, Carly; Campbell, Colin; Vogel, Matthew; Colunga, Aaron; Conger, Bruce

2012-01-01

The Spacesuit Water Membrane Evaporator (SWME) is a heat-rejection device that is being developed to perform thermal control for advanced spacesuits. Cooling is achieved by circulating water from the liquid cooling garment (LCG) through hollow fibers (HoFi s), which are small hydrophobic tubes. Liquid water remains within the hydrophobic tubes, but water vapor is exhausted to space, thereby removing heat. A SWME test article was tested over the course of a year, for a total of 600 cumulative hours. In order to evaluate SWME tolerance to contamination due to constituents caused by distillation processes, these constituents were allowed to accumulate in the water as evaporation occurred. A test article was tested over the course of a year for a total of 600 cumulative hours. The heat rejection performance of the SWME degraded significantly--below 700 W, attributable to the accumulation of rust in the circulating loop and biofilm growth. Bubble elimination capability, a feature that was previously proven with SWME, was compromised during the test, most likely due to loss of hydrophobic properties of the hollow fibers. The utilization of water for heat rejection was shown not to be dependent on test article, life cycle, heat rejection rate, or freezing of the membranes.

The Effects of Liquid Cooling Garments on Post-Space Flight Orthostatic Intolerance

NASA Technical Reports Server (NTRS)

Billica, Roger; Kraft, Daniel

1997-01-01

Post space flight orthostatic intolerance among Space Shuttle crew members following exposure to extended periods of microgravity has been of significant concern to the safety of the shuttle program. Following the Challenger accident, flight crews were required to wear launch and entry suits (LES). It was noted that overall, there appeared to be a higher degree of orthostatic intolerance among the post-Challenger crews (approaching 30%). It was hypothesized that the increased heat load incurred when wearing the LES, contributed to an increased degree of orthostatic intolerance, possibly mediated through increased peripheral vasodilatation triggered by the heat load. The use of liquid cooling garments (LCG) beneath the launch and entry suits was gradually implemented among flight crews in an attempt to decrease heat load, increase crew comfort, and hopefully improve orthostatic tolerance during reentry and landing. The hypothesis that the use of the LCG during reentry and landing would decrease the degree of orthostasis has not been previously tested. Operational stand-tests were performed pre and post flight to assess crewmember's cardiovascular system's ability to respond to gravitational stress. Stand test and debrief information were collected and databased for 27 space shuttle missions. 63 crewpersons wearing the LCG, and 70 crewpersons not wearing the LCG were entered into the database for analysis. Of 17 crewmembers who exhibited pre-syncopal symptoms at the R+O analysis, 15 were not wearing the LCG. This corresponds to a 21% rate of postflight orthostatic intolerance among those without the LCG, and a 3% rate for those wearing LCG. There were differences in these individual's average post-flight maximal systolic blood pressure, and lower minimal Systolic Blood pressures in those without LCG. Though other factors, such as type of fluid loading, and exercise have improved concurrently with LCG introduction, from this data analysis, it appears that LCG usage provided a significant degree of protection from post-flight orthostatic intolerance.

MS Grunsfeld and Linnehan on middeck after EVA 1

NASA Image and Video Library

2002-03-04

STS109-349-027 (4 March 2002) --- Astronauts John M. Grunsfeld and Richard M. Linnehan, STS-109 payload commander and mission specialist, respectively, wearing the liquid cooling and ventilation garment that complements the Extravehicular Mobility Unit (EMU) space suit, are photographed on the mid deck of the Space Shuttle Columbia after the mission’s first session of extravehicular activity (EVA). The EVA-1 team replaced one of the telescope’s two second-generation solar arrays, which is also known as SA2, and a Diode Box Assembly. The solar array was replaced with a new, third-generation solar array, which is called SA3. The space walkers also did some prep work for STS-109’s other space walks.

Effects of a whole-body spandex garment on rectal temperature and oxygen consumption in healthy dogs.

PubMed

Reimer, S Brent; Schulz, Kurt S; Mason, David R; Jones, James H

2004-01-01

To determine whether a full-body spandex garment would alter rectal temperatures of healthy dogs at rest in cool and warm environments. Prospective study. 10 healthy dogs. Each dog was evaluated at a low (20 degrees to 25 degrees C [68 degrees to 77 degrees F]) or high (30 degrees to 35 degrees C [86 degrees to 95 degrees F]) ambient temperature while wearing or not wearing a commercially available whole-body spandex garment designed for dogs. Oxygen consumption was measured by placing dogs in a flow-through indirect calorimeter for 90 to 120 minutes. Rectal temperature was measured before dogs were placed in the calorimeter and after they were removed. Rectal temperature increased significantly more at the higher ambient temperature than at the lower temperature and when dogs were not wearing the garment than when they were wearing it. The specific rate of oxygen consumption was significantly higher at the lower ambient temperature than at the higher temperature. Results suggest that wearing a snug spandex body garment does not increase the possibility that dogs will overheat while in moderate ambient temperatures. Instead, wearing such a garment may enable dogs to better maintain body temperature during moderate heat loading. These results suggest that such garments might be used for purposes such as wound or suture protection without causing dogs to overheat.

Development of a Prototype Water Pump for Future Space Suit Applications

NASA Technical Reports Server (NTRS)

Hartman, David; Hodgson, Edward; Dionne, Steven; Gervais, Edward, III; Trevino, Luis

2009-01-01

NASA's next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew's liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

Development of a Prototype Water Pump for Future Space Suit Applications

NASA Technical Reports Server (NTRS)

Hartman, David; Hodgson, Edward; Gervais, Edward, III; Trevino, Luis

2008-01-01

NASA s next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew s liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

Spacesuit Evaporator-Absorber-Radiator (SEAR)

NASA Technical Reports Server (NTRS)

Hodgson, Ed; Izenson, Mike; Chan, Weibo; Bue, Grant C.

2012-01-01

For decades advanced spacesuit developers have pursued a regenerable, robust nonventing system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA s Spacesuit Water Membrane Evaporator (SWME), and Creare s Lithium Chloride Absorber Radiator (LCAR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. This water vapor is then captured by solid LiCl in the LCAR with a high enthalpy of absorption, resulting in sufficient temperature lift to reject heat to space by radiation. After the sortie, the LCAR would be heated up and dried in a regenerator to drive off and recover the absorbed evaporant. A engineering development prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The LCAR was able to stably reject 75 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios.

Personal cooling in hot workings

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

Tuck, M.A.

1999-07-01

The number of mines experiencing climatic difficulties worldwide is increasing. In a large number of cases these climatic difficulties are confined to working areas only or to specific locations within working areas. Thus the problem in these mines can be described as highly localized, due to a large extent not to high rock temperatures but due to machine heat loads and low airflow rates. Under such situations conventional means of controlling the climate can be inapplicable and/or uneconomic. One possible means of achieving the required level of climatic control, to ensure worker health and safety whilst achieving economic gains, ismore » to adopt a system of active man cooling. This is the reverse of normal control techniques where the cooling power of the ventilating air is enhanced in some way. Current methods of active man cooling include ice jackets and various umbilical cord type systems. These have numerous drawbacks, such as limited useful exposure times and limitations to worker mobility. The paper suggests an alternative method of active man cooling than those currently available and reviews the design criteria for such a garment. The range of application of such a garment is discussed, under both normal and emergency situations.« less

Pre-cooling for endurance exercise performance in the heat: a systematic review

PubMed Central

2012-01-01

Background Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research. Methods The MEDLINE, EMBASE, CINAHL, Web of Science and SPORTDiscus databases were searched in May 2012 for studies evaluating the effectiveness of pre-cooling to enhance endurance exercise performance in hot environmental conditions (≥ 28°C). Studies involving participants with increased susceptibility to heat strain, cooling during or between bouts of exercise, and protocols where aerobic endurance was not the principle performance outcome were excluded. Potential publications were assessed by two independent reviewers for inclusion and quality. Means and standard deviations of exercise performance variables were extracted or sought from original authors to enable effect size calculations. Results In all, 13 studies were identified. The majority of studies contained low participant numbers and/or absence of sample size calculations. Six studies used cold water immersion, four crushed ice ingestion and three cooling garments. The remaining study utilized mixed methods. Large heterogeneity in methodological design and exercise protocols was identified. Effect size calculations indicated moderate evidence that cold water immersion effectively improved endurance performance, and limited evidence that ice slurry ingestion improved performance. Cooling garments were ineffective. Most studies failed to document or report adverse events. Low participant numbers in each study limited the statistical power of certain reported trends and lack of blinding could potentially have introduced either participant or researcher bias in some studies. Conclusions Current evidence indicates cold water immersion may be the most effective method of pre-cooling to improve endurance performance in hot conditions, although practicality must be considered. Ice slurry ingestion appears to be the most promising practical alternative. Interestingly, cooling garments appear of limited efficacy, despite their frequent use. Mechanisms behind effective pre-cooling remain uncertain, and optimal protocols have yet to be established. Future research should focus on standardizing exercise performance protocols, recruiting larger participant numbers to enable direct comparisons of effectiveness and practicality for each method, and ensuring potential adverse events are evaluated. PMID:23249542

Physiological and perceptual effects of a cooling garment during simulated industrial work in the heat.

PubMed

Butts, Cory L; Smith, Cody R; Ganio, Matthew S; McDermott, Brendon P

2017-03-01

Evaluate physiological and perceptual responses using a phase change cooling (PCC) garment during simulated work in the heat. Twenty males wearing compression undergarments, coverall suit, gloves, and hard-hat, completed two randomly assigned trials (with PCC inserts or control, CON) of simulated industrial tasks in the heat (34.2 ± 0.05 °C, 54.7 ± 0.3%RH). Trials consisted of two 20 min work bouts, a maximum performance bout, and 10 min of recovery. Physiological strain index (PSI) was lower during PCC after the second work bout and during recovery (all P < 0.05). PCC reduced heat storage (27.0 ± 7.6 W m -2 ) compared to CON (42.7 ± 9.9 W m -2 , P < 0.001). Perceptual strain index (PeSI) was reduced with PCC compared to CON (P < 0.001), however performance outcomes were not different between trials (P = 0.10). PCC during work in the heat attenuated thermal, physiological, and perceptual strain. This PCC garment could increase safety and reduce occupational heat illness risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Petty, Brian; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2015-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only approximately 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini-ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2014-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini- ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Thermoregulation and heat exchange in a nonuniform thermal environment during simulated extended EVA. Extravehicular activities

NASA Technical Reports Server (NTRS)

Koscheyev, V. S.; Leon, G. R.; Hubel, A.; Nelson, E. D.; Tranchida, D.

2000-01-01

BACKGROUND: Nonuniform heating and cooling of the body, a possibility during extended duration extravehicular activities (EVA), was studied by means of a specially designed water circulating garment that independently heated or cooled the right and left sides of the body. The purpose was to assess whether there was a generalized reaction on the finger in extreme contradictory temperatures on the body surface, as a potential heat status controller. METHOD: Eight subjects, six men and two women, were studied while wearing a sagittally divided experimental garment with hands exposed in the following conditions: Stage 1 baseline--total body garment inlet water temperature at 33 degrees C; Stage 2--left side inlet water temperature heated to 45 degrees C; right side cooled to 8 degrees C; Stage 3--left side inlet water temperature cooled to 8 degrees C, right side heated to 45 degrees C. RESULTS: Temperatures on each side of the body surface as well as ear canal temperature (Tec) showed statistically significant Stage x Side interactions, demonstrating responsiveness to the thermal manipulations. Right and left finger temperatures (Tfing) were not significantly different across stages; their dynamic across time was similar. Rectal temperature (Tre) was not reactive to prevailing cold on the body surface, and therefore not informative. Subjective perception of heat and cold on the left and right sides of the body was consistent with actual temperature manipulations. CONCLUSIONS: Tec and Tre estimates of internal temperature do not provide accurate data for evaluating overall thermal status in nonuniform thermal conditions on the body surface. The use of Tfing has significant potential in providing more accurate information on thermal status and as a feedback method for more precise thermal regulation of the astronaut within the EVA space suit.

Cryotherapy Reinvented: Application of Phase Change Material for Recovery in Elite Soccer.

PubMed

Clifford, Tom; Abbott, Will; Kwiecien, Susan Y; Howatson, Glyn; McHugh, Malachy P

2018-05-01

To examine whether donning lower-body garments fitted with cooled phase change material (PCM) would enhance recovery after a soccer match. In a randomized, crossover design, 11 elite soccer players from the reserve squad of a team in the second-highest league in England wore PCM cooled to 15°C (PCM cold ) or left at ambient temperature (PCM amb ; sham control) for 3 h after a soccer match. To assess recovery, countermovement jump height, maximal isometric voluntary contraction (MIVC), muscle soreness, and the adapted Brief Assessment of Mood Questionnaire (BAM+) were measured before 12, 36, and 60 h after each match. A belief questionnaire was completed preintervention and postintervention to determine the perceived effectiveness of each garment. Results are comparisons between the 2 conditions at each time point postmatch. MIVC at 36 h postmatch was greater with PCM cold versus PCM warm (P = .01; ES = 1.59; 95% CI, 3.9-17.1%). MIVC also tended to be higher at 60 h postmatch (P = .05; ES = 0.85; 95% CI, -0.4% to 11.1%). Muscle soreness was 26.5% lower in PCM cold versus PCM warm at 36 h (P = .02; ES = 1.7; 95% CI, -50.4 to -16.1 mm) and 24.3% lower at 60 h (P = .04; ES = 1.1; 95% CI, -26.9 to -0.874 mm). There were no between-conditions differences in postmatch countermovement jump height or BAM+ (P > .05). The belief questionnaire revealed that players felt the PCM cold was more effective than the PCM amb after the intervention (P = .004). PCM cooling garments provide a practical means of delivering prolonged postexercise cooling and thereby accelerate recovery in elite soccer players.

Thermoregulation and heat exchange in a nonuniform thermal environment during simulated extended EVA. Extravehicular activities.

PubMed

Koscheyev, V S; Leon, G R; Hubel, A; Nelson, E D; Tranchida, D

2000-06-01

Nonuniform heating and cooling of the body, a possibility during extended duration extravehicular activities (EVA), was studied by means of a specially designed water circulating garment that independently heated or cooled the right and left sides of the body. The purpose was to assess whether there was a generalized reaction on the finger in extreme contradictory temperatures on the body surface, as a potential heat status controller. Eight subjects, six men and two women, were studied while wearing a sagittally divided experimental garment with hands exposed in the following conditions: Stage 1 baseline--total body garment inlet water temperature at 33 degrees C; Stage 2--left side inlet water temperature heated to 45 degrees C; right side cooled to 8 degrees C; Stage 3--left side inlet water temperature cooled to 8 degrees C, right side heated to 45 degrees C. Temperatures on each side of the body surface as well as ear canal temperature (Tec) showed statistically significant Stage x Side interactions, demonstrating responsiveness to the thermal manipulations. Right and left finger temperatures (Tfing) were not significantly different across stages; their dynamic across time was similar. Rectal temperature (Tre) was not reactive to prevailing cold on the body surface, and therefore not informative. Subjective perception of heat and cold on the left and right sides of the body was consistent with actual temperature manipulations. Tec and Tre estimates of internal temperature do not provide accurate data for evaluating overall thermal status in nonuniform thermal conditions on the body surface. The use of Tfing has significant potential in providing more accurate information on thermal status and as a feedback method for more precise thermal regulation of the astronaut within the EVA space suit.

Skin Temperatures During Unaided Egress: Unsuited and While Wearing the NASA Launch and Entry or Advanced Crew Escape Suits

NASA Technical Reports Server (NTRS)

Woodruff, Kristin K.; Lee, Stuart M. C.; Greenisen, Michael C.; Schneider, Suzanne M.

2000-01-01

The two flight suits currently worn by crew members during Shuttle launch and landing, the Launch and Entry Suit (LES) and the Advanced Crew Escape Suit (ACES), are designed to protect crew members in the case of emergency. Although the Liquid Cooling Garment (LCG) worn under the flight suits was designed to counteract the heat storage of the suits, the suits may increase thermal stress and limit the astronaut's egress capabilities. The purpose of this study was to assess the thermal loads experienced by crew members during a simulated emergency egress before and after spaceflight. Comparisons of skin temperatures were made between the preflight unsuited and suited conditions. between the pre- and postflight suited conditions, and between the two flight suits.

Humidifier Development and Applicability to the Next Generation Portable Life Support System

NASA Technical Reports Server (NTRS)

Conger, Bruce C.; Barnes, Bruce G.; Sompayrac, Robert G.; Paul, Heather L.

2011-01-01

A development effort at the NASA Johnson Space Center investigated technologies to determine whether a humidifier would be required in the Portable Life Support System (PLSS) envisioned for future exploration missions. The humidifier has been included in the baseline PLSS schematic since performance testing of the Rapid Cycle Amine (RCA) indicates that the RCA over-dries the ventilation gas stream. Performance tests of a developmental humidifier unit and commercial off-the-shelf (COTS) units were conducted in December 2009. Following these tests, NASA revisited the need for a humidifier via system analysis. Results of this investigation indicate that it is feasible to meet humidity requirements without the humidifier if other changes are made to the PLSS ventilation loop and the Liquid Cooling and Ventilation Garment (LCVG).

Efficacy of Wrist/Palm Warming as an EVA Countermeasure to Maintain Finger Comfort in Cold Conditions During EVA

NASA Technical Reports Server (NTRS)

Koscheyev, Victor S.; Leon, Gloria R.; Trevino, Robert C.

2000-01-01

This study explored the effectiveness of local wrist/palm warming as a potential countermeasure for providing finger comfort during extended duration EVA. Methods: Six subjects (5 males and 1 female) were evaluated in a sagitally divided liquid cooling/warming garment (LCWG) with modified liquid cooling/warming (LCW) gloves in three different experimental conditions. Condition 1: Stage 1- no LCWG; chamber adaptation with LCW glove inlet water temperature 33 C; Stage 2-LCW glove inlet water temperature cooled to 8 C; Stage 3-LCW glove inlet water temperature warmed to 45 C; Condition 2: Stage1-LCWG and LCW glove inlet water temperature 33 C; Stage 2-LCWG inlet temperature cooled to 31 C, LCW gloves, 8 C; Stage 3-LCWG inlet water temperature remains at 31 C, LCW glove inlet water temperature warmed to 45 C; Condition 3: Stage l -LCWG and LCW gloves 33 C; Stage 2-LCWG inlet water temperature cooled to 28 C, LCW gloves, 8 C; Stage 3-LCWG remains at 28 C, LCW glove water temperature warmed to 45 C. Results: Wrist/palm area warming significantly increased finger temperature (Tfing) and blood perfusion in Stage 3 compared to Stage 2. The LCW gloves were most effective in increasing Stage 3 Tfing in Condition 1; and in increasing blood perfusion in Conditions 1 and 2 compared to Condition 3. Ratings of subjective perception of heat in the hand and overall body heat were higher at Stage 3 than Stage 2, with no significant differences across Conditions. Conclusions: Local wrist/palm warming was effective in increasing blood circulation to the distal extremities, suggesting the potential usefulness of this technique for increasing astronaut thermal comfort during EVA while decreasing power requirements. The LCW gloves were effective in heating the highly cooled fingers when the overall body was in a mild heat deficit.

Drug smuggling using clothing impregnated with cocaine.

PubMed

McDermott, Seán D; Power, John D

2005-11-01

A case study is presented where a woman travelling from South America to the Republic of Ireland was detained at Dublin Airport and articles of clothing she had in her luggage were found to be impregnated with cocaine. The study shows that the amount of powder recovered from the garments was approximately 14% of the total weight of the garments. The cocaine was in the form of cocaine hydrochloride and the purity was approximately 80%. An examination of the garments under filtered light highlighted the areas exposed to cocaine and indicated that the method of impregnation was by pouring liquid containing cocaine onto the clothing.

Use of Thermoregulatory Models to Enhance Space Shuttle and Space Station operations and Review of Human Thermoregulatory Control

NASA Technical Reports Server (NTRS)

Pisacane, V. L.; Kuznetz, L. H.; Logan, J. S.; Clark, J. B.; Wissler, E. H.

2007-01-01

Thermoregulation in the space environment is critical for survival, especially in off- nominal operations. In such cases, mathematical models of thermoregulation are frequently employed to evaluate safety-of-flight issues in various human mission scenarious. In this study, the 225-node Wissler model and the 41-Node Metabolic Man model are employed to evaluate the effects of such a scenario. Metabolic loads on astronauts wearing the advanced crew escape suit (ACES) and liquid cooled ventilation garment (LCVG) are imposed on astronauts exposed to elevated cabin temperatures resulting from a systems failure. The study indicates that the performance of the ACES/LCVG cooling system is marginal. Increases in workload and or cabin temperature above nominal will increase rectal temperature, stored heat load, heart rate, and sweating, which could lead to deficits in the performance of cognitive and motor tasks. This is of concern as the ACES/LCVG is employed during Shuttle decent when the likelihood of a safe landing may be compromised. The study indicates that the most effective mitigation strategy would be to decrease the LCVG inlet temperature.

A portable personal cooling system for mine rescue operations

NASA Technical Reports Server (NTRS)

Webbon, B.; Williams, B.; Kirk, P.; Elkins, W.; Stein, R.

1977-01-01

Design of a portable personal cooling system to reduce physiological stress in high-temperature, high-humidity conditions is discussed. The system, based on technology used in the thermal controls of space suits, employs a combination of head and thoracic insulation and cooling through a heat sink unit. Average metabolic rates, heart rates, rectal temperature increase and sweat loss were monitored for test subjects wearing various configurations of the cooling system, as well as for a control group. The various arrangements of the cooling garment were found to provide significant physiological benefits; however, increases in heat transfer rate of the cooling unit and more effective insulation are suggested to improve the system's function.

Protective supplied-breathing-air garment

DOEpatents

Childers, E.L.; von Hortenau, E.F.

1982-05-28

A breathing-air garment for isolating a wearer from hostile environments containing toxins or irritants is disclosed. The garment includes a suit and a separate head-protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air-delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air-delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit sealed with an adhesive sealing flap.

Heat stress control in the TMI-2 (Three Mile Island Unit 2) defueling and decontamination activities

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

Schork, J.S.; Parfitt, B.A.

During the initial stages of the Three Mile Island Unit 2 (TMI-2) defueling and decontamination activities for the reactor building, it was realized that the high levels of loose radioactive contamination would require the use of extensive protective clothing by entry personnel. While there was no doubt that layered protective clothing protects workers from becoming contaminated, it was recognized that these same layers of clothing would impose a very significant heat stress burden. To prevent the potentially serious consequences of a severe reaction to heat stress by workers in the hostile environment of the TMI-2 reactor building and yet maintainmore » the reasonable work productivity necessary to perform the recovery adequately, an effective program of controlling worker exposure to heat stress had to be developed. Body-cooling devices produce a flow of cool air, which is introduced close to the skin to remove body heat through convection and increased sweat evaporation. The cooling effect produced by the Vortex tube successfully protected the workers from heat stress, however, there were several logistical and operational problems that hindered extensive use of these devices. The last type of cooling garment examined was the frozen water garment (FWG) developed by Elizier Kamon at the Pennsylvania State University as part of an Electric Power Research Institute research grant. Personal protection, i.e., body cooling, engineering controls, and administrative controls, have been implemented successfully.« less

Water Vapor Permeability of the Advanced Crew Escape Suit

NASA Technical Reports Server (NTRS)

Bue, Grant; Kuznetz, Larry; Gillis, David; Jones, Jeffery; Daniel, Brian; Gernhardt, Michael; Hamilton, Douglas

2009-01-01

Crew Exploration Vehicle (CEV) crewmembers are expected to return to earth wearing a suit similar to the current Advanced Crew Escape Suit (ACES). To ensure optimum cognitive performance, suited crewmembers must maintain their core body temperature within acceptable limits. There are currently several options for thermal maintenance in the post-landing phase. These include the current baseline, which uses an ammonia boiler, purge flow using oxygen in the suit, accessing sea water for liquid cooling garment (LCG) cooling and/or relying on the evaporative cooling capacity of the suit. These options vary significantly in mass, power, engineering and safety factors, with relying on the evaporative cooling capacity of the suit being the least difficult to implement. Data from previous studies indicates that the evaporative cooling capacity of the ACES was much higher than previously expected, but subsequent tests were performed for longer duration and higher metabolic rates to better define the water vapor permeability of the ACES. In these tests five subjects completed a series of tests performing low to moderate level exercise in order to control for a target metabolic rate while wearing the ACES in an environmentally controlled thermal chamber. Four different metabolic profiles at a constant temperature of 95 F and relative humidity of 50% were evaluated. These tests showed subjects were able to reject about twice as much heat in the permeable ACES as they were in an impermeable suit that had less thermal insulation. All of the heat rejection differential is attributed to the increased evaporation capability through the Gortex bladder of the suit.

Management of the Post-Shuttle Extravehicular Mobility Unit (EMU) Water Circuits

NASA Technical Reports Server (NTRS)

Steele, John W.; Etter, David; Rector, Tony; Hill, Terry; Wells, Kevin

2011-01-01

The EMU incorporates two separate water circuits for the rejection of metabolic heat from the astronaut and the cooling of electrical components. The first (the Transport Water Loop) circulates in a semi-closed-loop manner and absorbs heat into a Liquid Coolant and Ventilation Garment (LCVG) warn by the astronaut. The second (the Feed Water Loop) provides water to a cooling device (Sublimator) with a porous plate, and that water subsequently sublimates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. Efforts are underway to streamline the use of a water processing kit (ALCLR) that is being used to periodically clean and disinfect the Transport Loop Water. Those efforts include a fine tuning of the duty cycle based on a review of prior performance data as well as an assessment of a fixed installation of this kit into the EMU backpack or within on-orbit EMU interface hardware. Furthermore, testing is being conducted to ensure compatibility between the International Space Station (ISS) Water Processor Assembly (WPA) effluent and the EMU Sublimator as a prelude to using the WPA effluent as influent to the EMU Feed Water loop. This work is undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post-Shuttle 6-year service life.

Management of the Post-Shuttle Extravehicular Mobility Unit (EMU) Water Circuits

NASA Technical Reports Server (NTRS)

Steele, John W.; Etter, David; Rector, Tony; Hill, Terry; Wells, Kevin

2012-01-01

The EMU incorporates two separate water circuits for the rejection of metabolic heat from the astronaut and the cooling of electrical components. The first (the Transport Water Loop) circulates in a semi-closed-loop manner and absorbs heat into a Liquid Coolant and Ventilation Garment (LCVG) worn by the astronaut. The second (the Feed-water Loop) provides water to a cooling device (Sublimator) with a porous plate, and that water subsequently sublimates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. Efforts are underway to streamline the use of a water processing kit (ALCLR) that is being used to periodically clean and disinfect the Transport Loop Water. Those efforts include a fine tuning of the duty cycle based on a review of prior performance data as well as an assessment of a fixed installation of this kit into the EMU backpack, within on-orbit EMU interface hardware or as a stand-alone unit. Furthermore, testing is being conducted to ensure compatibility between the International Space Station (ISS) Water Processor Assembly (WPA) effluent and the EMU Sublimator as a prelude to using the WPA effluent as influent to the EMU Feed Water loop. This work is undertaken to reduce the crewtime and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a 6-year service life.

An improved thermoregulatory model for cooling garment applications with transient metabolic rates

NASA Astrophysics Data System (ADS)

Westin, Johan K.

Current state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving thermal comfort and cognitive performance. In this study, we adopt the Fiala thermoregulatory model, which has previously demonstrated state-of-the-art predictive abilities in air environments, for use in LCG environments. We validate the numerical formulation with analytical solutions to the bioheat equation, and find our model to be accurate and stable with a variety of different grid configurations. We then compare the thermoregulatory model's tissue temperature predictions with experimental data where individuals, equipped with an LCG, exercise according to a 700 W rectangular type activity schedule. The root mean square (RMS) deviation between the model response and the mean experimental group response is 0.16°C for the rectal temperature and 0.70°C for the mean skin temperature, which is within state-of-the-art variations. However, with a mean absolute body heat storage error 3¯ BHS of 9.7 W˙h, the model fails to satisfy the +/-6.5 W˙h accuracy that is required for the automatic LCG cooling control development. In order to improve model predictions, we modify the blood flow dynamics of the thermoregulatory model. Instead of using step responses to changing requirements, we introduce exponential responses to the muscle blood flow and the vasoconstriction command. We find that such modifications have an insignificant effect on temperature predictions. However, a new vasoconstriction dependency, i.e. the rate of change of hypothalamus temperature weighted by the hypothalamus error signal (DeltaThy˙ dThy/dt), proves to be an important signal that governs the thermoregulatory response during conditions of simultaneously increasing core and decreasing skin temperatures, which is a common scenario in LCG environments. With the new ?DeltaThy˙dThy /dt dependency in the vasoconstriction command, the 3¯ BHS for the exercise period is reduced by 59% (from 12.9 W˙h to 5.2 W˙h). Even though the new 3¯ BHS of 5.8 W˙h for the total activity schedule is within the target accuracy of +/-6.5 W˙h, 3¯ BHS fails to stay within the target accuracy during the entire activity schedule. With additional improvements to the central blood pool formulation, the LCG boundary condition, and the agreement between model set-points and actual experimental initial conditions, it seems possible to achieve the strict accuracy that is needed for automatic cooling control development.

Drawing of the Buddy Secondary Life Support System

NASA Image and Video Library

1970-12-22

S70-56965 (December 1970) --- Drawing of the newly developed Buddy Secondary Life Support System (BSLSS). The life-sustaining system will be provided for the first time on the Apollo 14 lunar landing mission. The two flexible hoses, to be used on the second Apollo 14 extravehicular activity (EVA), will be among the paraphernalia on the Modular Equipment Transporter (MET) or two-wheeled workshop, and readily accessible in an emergency. During EVAs the Portable Life Support System (PLSS) supplies the astronaut with breathing and suit-pressurizing oxygen and water flow for the liquid-cooling garment -- a suit of knitted long underwear with thin tubing woven in the torso and limbs. The tubes carry water from a reservoir in the PLSS, and the circulating water serves to carry the astronaut's metabolic heat to a heat exchanger in the PLSS. Before the BSLSS was devised, the emergency tank was required to furnish not only suit pressure and breathing oxygen, but also cooling through a high oxygen flow rate. The BSLSS, by sharing the water supply between the two crewmen, stretches the time of the emergency oxygen from about 40 minutes to 60 to 75 minutes.

Spacesuit Evaporator-Absorber-Radiator (SEAR)

NASA Technical Reports Server (NTRS)

Bue, Grant C.; Hodgson, Ed; Izenso, Mike; Chan, Weibo; Cupples, Scott

2011-01-01

For decades advanced spacesuit developers have pursued a regenerable, robust non-venting system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA's Spacesuit Water Membrane Evaporator (SWME), and Creare's lithium chloride Heat Pump Radiator (HPR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. The SEAR is evacuated at the onset of operations and thereafter, the water vapor absorption rate of the HPR maintains a low pressure environment for the SWME to evaporate effectively. This water vapor captured by solid LiCl in the HPR with a high enthalpy of absorption, results in sufficient temperature lift to reject most of the heat to space by radiation. After the sortie, the HPR would be heated up in a regenerator to drive off and recover the absorbed evaporant. A one-fourth scale prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The HPR was able to stably reject 60 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios.

NASA Tech Briefs, August 2005

NASA Technical Reports Server (NTRS)

2005-01-01

Topics include: Hidden Identification on Parts: Magnetic Machine-Readable Matrix Symbols; System for Processing Coded OFDM Under Doppler and Fading; Multipurpose Hyperspectral Imaging System; Magnetic-Flux-Compensated Voltage Divider; High-Performance Satellite/Terrestrial-Network Gateway; Internet-Based System for Voice Communication With the ISS; Stripline/Microstrip Transition in Multilayer Circuit Board; Dual-Band Feed for a Microwave Reflector Antenna; Quadratic Programming for Allocating Control Effort; Range Process Simulation Tool; Simulator of Space Communication Networks; Computing Q-D Relationships for Storage of Rocket Fuels; Contour Error Map Algorithm; Portfolio Analysis Tool; Glass Frit Filters for Collecting Metal Oxide Nanoparticles; Anhydrous Proton-Conducting Membranes for Fuel Cells; Portable Electron-Beam Free-Form Fabrication System; Miniature Laboratory for Detecting Sparse Biomolecules; Multicompartment Liquid-Cooling/Warming Protective Garments; Laser Metrology for an Optical-Path-Length Modulator; PCM Passive Cooling System Containing Active Subsystems; Automated Electrostatics Environmental Chamber; Estimating Aeroheating of a 3D Body Using a 2D Flow Solver; Artificial Immune System for Recognizing Patterns; Computing the Thermodynamic State of a Cryogenic Fluid; Safety and Mission Assurance Performance Metric; Magnetic Control of Concentration Gradient in Microgravity; Avionics for a Small Robotic Inspection Spacecraft; and Simulation of Dynamics of a Flexible Miniature Airplane.

Thermal Performance Testing of EMU and CSAFE Liquid Cooling Gannents

NASA Technical Reports Server (NTRS)

Rhodes, Richard; Bue, Grant; Meginnis, Ian; Hakam, Mary; Radford, Tamara

2013-01-01

Future exploration missions require the development of a new liquid cooling garment (LCG) to support the next generation extravehicular activity (EVA) suit system. The new LCG must offer greater system reliability, optimal thermal performance as required by mission directive, and meet other design requirements including improved tactile comfort. To advance the development of a future LCG, a thermal performance test was conducted to evaluate: (1) the comparable thermal performance of the EMU LCG and the CSAFE developed engineering evaluation unit (EEU) LCG, (2) the effect of the thermal comfort undergarment (TCU) on the EMU LCG tactile and thermal comfort, and (3) the performance of a torso or upper body only LCG shirt to evaluate a proposed auxiliary loop. To evaluate the thermal performance of each configuration, a metabolic test was conducted using the Demonstrator Spacesuit to create a relevant test environment. Three (3) male test subjects of similar height and weight walked on a treadmill at various speeds to produce three different metabolic loads - resting (300-600 BTU/hr), walking at a slow pace (1200 BTU/hr), and walking at a brisk pace (2200 BTU/hr). Each subject participated in five tests - two wearing the CSAFE full LCG, one wearing the EMU LCG without TCUs, one wearing the EMU LCG with TCUs, and one with the CSAFE shirt-only. During the test, performance data for the breathing air and cooling water systems and subject specific data was collected to define the thermal performance of the configurations. The test results show that the CSAFE EEU LCG and EMU LCG with TCU had comparable performance. The testing also showed that an auxiliary loop LCG, sized similarly to the shirt-only configuration, should provide adequate cooling for contingency scenarios. Finally, the testing showed that the TCU did not significantly hinder LCG heat transfer, and may prove to be acceptable for future suit use with additional analysis and testing.

Cool Vest

NASA Technical Reports Server (NTRS)

1982-01-01

ILC, Dover Division's lightweight cooling garment, called Cool Vest was designed to eliminate the harmful effects of heat stress; increases tolerance time in hot environments by almost 300 percent. Made of urethane-coated nylon used in Apollo, it works to keep the body cool, circulating chilled water throughout the lining by means of a small battery-powered pump. A pocket houses the pump, battery and the coolant which can be ice or a frozen gel, a valve control allows temperature regulation. One version is self-contained and portable for unrestrained movement, another has an umbilical line attached to an external source of coolant, such as standard tap water, when extended mobility is not required. It is reported from customers that the Cool Vest pays for itself in increased productivity in very high temperatures.

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

NASA Astrophysics Data System (ADS)

Chitrphiromsri, Patirop; Kuznetsov, Andrey V.

2005-01-01

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

Cooling Vest

NASA Technical Reports Server (NTRS)

1983-01-01

Because quadriplegics are unable to perspire below the level of spinal injury, they cannot tolerate heat stress. A cooling vest developed by Ames Research Center and Upjohn Company allows them to participate in outdoor activities. The vest is an adaptation of Ames technology for thermal control garments used to remove excess body heat of astronauts. The vest consists of a series of corrugated channels through which cooled water circulates. Its two outer layers are urethane coated nylon, and there is an inner layer which incorporates the corrugated channels. It can be worn as a backpack or affixed to a wheelchair. The unit includes a rechargeable battery, mini-pump, two quart reservoir and heat sink to cool the water.

Thermal exchanges and temperature stress

NASA Technical Reports Server (NTRS)

Webb, P.

1975-01-01

Thermal comfort during space flight is discussed. Heat production of man during space flight and wear loss as a mean of dissipating heat are described. Water cooled garments are also considered, along with tolerance for extreme heat and body heat storage. Models of human temperature regulation are presented in the form of documented FORTRAN programs.

Impact of a Protective Vest and Spacer Garment on Exercise-Heat Strain

DTIC Science & Technology

2008-01-01

or condi- tioning (air cooling/ dehumidification ) is used due to increased weight, noise, and cost. Thermal manikin and modeling analyses at 1 m/s...of sphericity was violated, F values were adjusted using Greenhouse -Geisser or Huynh-Feldt values as appropriate. Tukey’s HSD pro- cedure was used to

Efforts to Reduce International Space Station Crew Maintenance Time in the Management of the Extravehicular Mobility Unit Transport Loop Water Quality

NASA Technical Reports Server (NTRS)

Etter,David; Rector, Tony; Boyle, robert; Zande, Chris Vande

2012-01-01

The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR - Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post- Shuttle 6-year service life.

Efforts to Reduce International Space Station Crew Maintenance for the Management of the Extravehicular Mobility Unit Transport Loop Water Quality

NASA Technical Reports Server (NTRS)

Steele, John W.; Etter, David; Rector, Tony; Boyle, Robert; Vandezande, Christopher

2013-01-01

The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with on-orbit ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post-Shuttle 6-year service life.

Thermoregulatory and Perceptual Effects of a Percooling Garment Worn Underneath an American Football Uniform.

PubMed

Keen, Megan L; Miller, Kevin C; Zuhl, Micah N

2017-11-01

Keen, ML, Miller, KC, and Zuhl, MN. Thermoregulatory and perceptual effects of a percooling garment worn underneath an American football uniform. J Strength Cond Res 31(11): 2983-2991, 2017-American football athletes are at the highest risk of developing exertional heat illness (EHI). We investigated whether percooling (i.e., cooling during exercise) garments affected perceptual or physiological variables in individuals exercising in the heat while wearing football uniforms. Twelve male participants (age = 24 ± 4 year, mass = 80.1 ± 8.5 kg, height = 182.5 ± 10.4 cm) completed this cross-over, counterbalanced study. On day 1, we measured peak oxygen consumption (V[Combining Dot Above]O2). On days 2 and 3, participants wore percooling garments with (ICE) or without (CON) ice packs over the femoral and brachial arteries. They donned a football uniform and completed 3, 20-minute bouts of treadmill exercise at ∼50% of peak V[Combining Dot Above]O2 (∼33° C, ∼42% relative humidity) followed by a 10-minute rest period. Ice packs were replaced every 20 minutes. Rating of perceived exertion (RPE), thermal sensation, and thirst sensation were measured before and after each exercise bout. Environmental symptoms questionnaire (ESQ) responses and urine specific gravity (Usg) were measured pretesting and after the last exercise bout. V[Combining Dot Above]O2, change in heart rate (ΔHR), and change in rectal temperature (ΔTrec) were measured every 5 minutes. Sweat rate, sweat volume, and percent hypohydration were calculated. No interactions (F17,187 ≤ 1.6, p ≥ 0.1) or main effect of cooling condition (F1,11 ≤ 1.4, p ≥ 0.26) occurred for ΔTrec, ΔHR, thermal sensation, thirst, RPE, ESQ, or Usg. No differences between conditions occurred for sweat volume, sweat rate, or percent hypohydration (t11 ≤ 0.7, p ≥ 0.25). V[Combining Dot Above]O2 differed between conditions over time (F15,165 = 3.3, p < 0.001); ICE was lower than CON at 30, 55, and 70 minutes (p ≤ 0.05). It is unlikely that these garments would prevent EHI or minimize dehydration in football athletes.

Reducing heat stress under thermal insulation in protective clothing: microclimate cooling by a 'physiological' method.

PubMed

Glitz, K J; Seibel, U; Rohde, U; Gorges, W; Witzki, A; Piekarski, C; Leyk, D

2015-01-01

Heat stress caused by protective clothing limits work time. Performance improvement of a microclimate cooling method that enhances evaporative and to a minor extent convective heat loss was tested. Ten male volunteers in protective overalls completed a work-rest schedule (130 min; treadmill: 3 × 30 min, 3 km/h, 5% incline) with or without an additional air-diffusing garment (climatic chamber: 25°C, 50% RH, 0.2 m/s wind). Heat loss was supported by ventilating the garment with dry air (600 l/min, ≪5% RH, 25°C). Ventilation leads (M ± SD, n = 10, ventilated vs. non-ventilated) to substantial strain reduction (max. HR: 123 ± 12 b/min vs. 149 ± 24 b/min) by thermal relief (max. core temperature: 37.8 ± 0.3°C vs. 38.4 ± 0.4°C, max. mean skin temperature: 34.7 ± 0.8°C vs. 37.1 ± 0.3°C) and offers essential extensions in performance and work time under thermal insulation. Heat stress caused by protective clothing limits work time. Performance can be improved by a microclimate cooling method that supports evaporative and to a minor extent convective heat loss. Sweat evaporation is the most effective thermoregulatory mechanism for heat dissipation and can be enhanced by insufflating dry air into clothing.

Comparison between required clothing insulation and that actually worn by workers exposed to artificial cold.

PubMed

Aptel, M

1988-12-01

Required Clothing Insulation (IREQ) is a new thermal index submitted to the International Organisation for Standardisation (ISO) for discussion. It is designed to prevent general body cooling and is based on an analysis of heat exchanges. The thermal clothing insulation actually worn (lcl) is estimated using a new method, also submitted to ISO. IREQ of 54 workers exposed to artificial cold (air temperature between -30 degrees C and +10 degrees C) was compared with lcl actually worn by these workers. The results of the present study show that, on average, the workers choose accurately lcl they need if their IREQ is below and up to 1.5 clo. Moreover, these workers prefer to wear garments which provide them with thermal comfort. If IREQ of workers is higher than 1.5-2 clo (i e, workers exposed to -20 degrees C), it is difficult for them to increase their thermal insulation with additional garments. Although their lcl is not sufficient, there is no risk of gradual body cooling because of their continuous time exposure (CTE) which is shorter than the calculated Duration Limited Exposure (DLE). On the other hand, Wind Chill Index (WCI), which is proposed to prevent local cooling, is better adapted to prevent cold injuries than physiological thermal strain; for example, impairment of manual dexterity cannot be prevented with this index.

Personal, closed-cycle cooling and protective apparatus and thermal battery therefor

DOEpatents

Klett, James W.; Klett, Lynn B.

2004-07-20

A closed-cycle apparatus for cooling a living body includes a heat pickup body or garment which permits evaporation of an evaporating fluid, transmission of the vapor to a condenser, and return of the condensate to the heat pickup body. A thermal battery cooling source is provided for removing heat from the condenser. The apparatus requires no external power and provides a cooling system for soldiers, race car drivers, police officers, firefighters, bomb squad technicians, and other personnel who may utilize protective clothing to work in hostile environments. An additional shield layer may simultaneously provide protection from discomfort, illness or injury due to harmful atmospheres, projectiles, edged weapons, impacts, explosions, heat, poisons, microbes, corrosive agents, or radiation, while simultaneously removing body heat from the wearer.

Cooling Properties of the Shuttle Advanced Crew Escape Spacesuit: Results of an Environmental Chamber Experiment

NASA Technical Reports Server (NTRS)

Hamilton, Douglas; Gillis, David; Bue, Grant; Son, Chan; Norcross, Jason; Kuznetz, Larry; Chapman, Kirt; Chhipwadia, Ketan; McBride, Tim

2008-01-01

The shuttle crew wears the Advanced Crew Escape Spacesuit (ACES) to protect themselves from cabin decompression and to support bail out during landing. ACES is cooled by a liquid-cooled garment (LCG) that interfaces to a heat exchanger that dumps heat into the cabin. The ACES outer layer is made of Gore-Tex(Registered TradeMark), permitting water vapor to escape while containing oxygen. The crew can only lose heat via insensible water losses and the LCG. Under nominal landing operations, the average cabin temperature rarely exceeds 75 F, which is adequate for the ACES to function. Problem A rescue shuttle will need to return 11 crew members if the previous mission suffers a thermal protection system failure, preventing it from returning safely to Earth. Initial analysis revealed that 11 crew members in the shuttle will increase cabin temperature at wheel stop above 80 F, which decreases the ACES ability to keep crew members cool. Air flow in the middeck of the shuttle is inhomogeneous and some ACES may experience much higher temperatures that could cause excessive thermal stress to crew members. Methods A ground study was conducted to measure the cooling efficiency of the ACES at 75 F, 85 F, and 95 F at 50% relative humidity. Test subjects representing 5, 50, and 95 percentile body habitus of the astronaut corps performed hand ergometry keeping their metabolic rate at 400, 600, and 800 BTU/hr for one hour. Core temperature was measured by rectal probe and skin, while inside and outside the suit. Environmental chamber wall and cooling unit inlet and outlet temperatures were measured using high-resolution thermistors ( 0.2 C). Conclusions Under these test conditions, the ACES was able to protect the core temperature of all test subjects, however thermal stress due to high insensible losses and skin temperature and skin heat flow may impact crew performance. Further research should be performed to understand the impact on cognitive performance.

Thermoregulatory and Orthostatic Responses to Wearing the Advanced Crew Escape Suit

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Jacobs, Tamara N.; McDaniel, Angela; Schneider, Suzanne M.

2006-01-01

Current NASA flight rules limit the maximum cabin temperature (23.9 C) during re-entry and landing to protect crewmembers from heat stress while wearing the Advanced Crew Escape Suit (ACES) and Liquid Cooling Garment (LCG). The primary purpose of this ground-based project was to determine whether the LCG could provide adequate cooling if ambient temperature reached 26.7 "C. The secondary objective was to determine whether there would be a graded effect of ambient temperature profiles with maximum temperatures of 23.9 (LO), 26.7 (MPD), and 29.4 C (HI). METHODS: Eight subjects underwent a 5-h temperature profile (22.8,26.7 C) in an environmental chamber while wearing the ACES and LCG. Subjects controlled the amount of cooling provided by the LCG. Core (T(sub core)),skin temperatures (T(sub sk)) and heart rate (HR) were measured every 15-min. A 10-minute stand test was administered pre- and post-chamber. Additionally, 4 subjects underwent the three 5-h temperature profiles (LO, MID, and HI) with the same measurements. RESULTS: In the 8 subjects completing the MID profile, T(sub core), and T(sub sk) decreased from the start' to the end of the chamber stay. Subjects completed the stand test without signs of orthostatic intolerance. In the 4 subjects who underwent all 3 profiles, there was no discernible pattern in T(sub core), T(sub sk), and HR responses across the temperature profiles. CONCLUSIONS: In the range of temperatures tested, subjects were able to sufficiently utilize the self-selected cooling to avoid any potential deleterious effects of wearing the ACES. However, these subjects were not microgravity exposed, which has been suggested to impair thermoregulation.

Testing of Disposable Protective Garments Against Isocyanate Permeation From Spray Polyurethane Foam Insulation.

PubMed

Mellette, Michael P; Bello, Dhimiter; Xue, Yalong; Yost, Michael; Bello, Anila; Woskie, Susan

2018-05-12

Diisocyanates (isocyanates), including methylene diphenyl diisocyanate (MDI), are the primary reactive components of spray polyurethane foam (SPF) insulation. They are potent immune sensitizers and a leading cause of occupational asthma. Skin exposure to isocyanates may lead to both irritant and allergic contact dermatitis and possibly contribute to systemic sensitization. More than sufficient evidence exists to justify the use of protective garments to minimize skin contact with aerosolized and raw isocyanate containing materials during SPF applications. Studies evaluating the permeation of protective garments following exposure to SPF insulation do not currently exist. To conduct permeation testing under controlled conditions to assess the effectiveness of common protective gloves and coveralls during SPF applications using realistic SPF product formulations. Five common disposable garment materials [disposable latex gloves (0.07 mm thickness), nitrile gloves (0.07 mm), vinyl gloves (0.07 mm), polypropylene coveralls (0.13 mm) and Tyvek coveralls (0.13 mm)] were selected for testing. These materials were cut into small pieces and assembled into a permeation test cell system and coated with a two-part slow-rise spray polyurethane foam insulation. Glass fiber filters (GFF) pretreated with 1-(9-anthracenylmethyl)piperazine) (MAP) were used underneath the garment to collect permeating isocyanates. GFF filters were collected at predetermined test intervals between 0.75 and 20.00 min and subsequently analyzed using liquid chromatography-tandem mass spectrometry. For each garment material, we assessed (i) the cumulative concentration of total isocyanate, including phenyl isocyanate and three MDI isomers, that effectively permeated the material over the test time; (ii) estimated breakthrough detection time, average permeation rate, and standardized breakthrough time; from which (iii) recommendations were developed for the use of similar protective garments following contamination by two-component spray polyurethane foam systems and the limitations of such protective garments were identified. Each type of protective garment material demonstrated an average permeation rate well below the ASTM method F-739 standardized breakthrough rate threshold of 100.0 ng/cm2 min-1. Disposable latex gloves displayed the greatest total isocyanate permeation rate (4.11 ng/cm2 min-1), followed by the vinyl and nitrile gloves, respectively. The Tyvek coverall demonstrated a greater average rate of isocyanate permeation than the polypropylene coveralls. Typical isocyanate loading was in the range of 900 to 15,000 ng MDI/cm2. Permeation test data collected during this study indicated that each type of protective garment evaluated, provided a considerable level of protection (i.e. 10-110-fold reduction from the level of direct exposure) against the isocyanate component of the SPF insulation mixture. Nitrile gloves and polypropylene coveralls demonstrated the lowest rate of permeation and the lowest cumulative permeation of total isocyanate for each garment type.

Cardiovascular effects of anti-G suit and cooling garment during space shuttle re-entry and landing.

PubMed

Perez, Sondra A; Charles, John B; Fortner, G William; Hurst, Victor; Meck, Janice V

2003-07-01

Many cardiovascular changes associated with spaceflight reduce the ability of the cardiovascular system to oppose gravity on return to Earth, leaving astronauts susceptible to orthostatic hypotension during re-entry and landing. Consequently, an anti-G suit was developed to protect arterial pressure during re-entry. A liquid cooling garment (LCG) was then needed to alleviate the thermal stress resulting from use of the launch and entry suit. We studied 34 astronauts on 22 flights (4-16 d). Subjects were studied 10 d before launch and on landing day. Preflight, crewmembers were suited with their anti-G suits set to the intended inflation for re-entry. Three consecutive measurements of heart rate and arterial pressure were obtained while seated and then again while standing. Three subjects who inflated the anti-G suits also donned the LCG for landing. Arterial pressure and heart rate were measured every 5 min during the de-orbit maneuver, through maximum G-loading (max-G) and touch down (TD). After TD, crew-members again initiated three seated measurements followed by three standing measurements. Astronauts with inflated anti-G suits had higher arterial pressure than those who did not have inflated anti-G suits during re-entry and landing (133.1 +/- 2.5/76.1 +/- 2.1 vs. 128.3 +/- 4.2/79.3 +/- 2.9, de-orbit; 157.3 +/- 4.5/102.1 +/- 3.6 vs. 145.2 +/- 10.5/95.7 + 5.5, max-G; 159.6 +/- 3.9/103.7 +/- 3.3 vs. 134.1 +/- 5.1/85.7 +/- 3.1, TD). In the group with inflated anti-G suits, those who also wore the LCG exhibited significantly lower heart rates than those who did not (75.7 +/- 11.5 vs. 86.5 +/- 6.2, de-orbit; 79.5 +/- 24.8 vs. 112.1 +/- 8.7, max-G; 84.7 +/- 8.0 vs. 110.5 +/- 7.9, TD). The anti-G suit is effective in supporting arterial pressure. The addition of the LCG lowers heart rate during re-entry.

Cardiovascular effects of anti-G suit and cooling garment during space shuttle re-entry and landing

NASA Technical Reports Server (NTRS)

Perez, Sondra A.; Charles, John B.; Fortner, G. William; Hurst, Victor 4th; Meck, Janice V.

2003-01-01

BACKGROUND: Many cardiovascular changes associated with spaceflight reduce the ability of the cardiovascular system to oppose gravity on return to Earth, leaving astronauts susceptible to orthostatic hypotension during re-entry and landing. Consequently, an anti-G suit was developed to protect arterial pressure during re-entry. A liquid cooling garment (LCG) was then needed to alleviate the thermal stress resulting from use of the launch and entry suit. METHODS: We studied 34 astronauts on 22 flights (4-16 d). Subjects were studied 10 d before launch and on landing day. Preflight, crewmembers were suited with their anti-G suits set to the intended inflation for re-entry. Three consecutive measurements of heart rate and arterial pressure were obtained while seated and then again while standing. Three subjects who inflated the anti-G suits also donned the LCG for landing. Arterial pressure and heart rate were measured every 5 min during the de-orbit maneuver, through maximum G-loading (max-G) and touch down (TD). After TD, crew-members again initiated three seated measurements followed by three standing measurements. RESULTS: Astronauts with inflated anti-G suits had higher arterial pressure than those who did not have inflated anti-G suits during re-entry and landing (133.1 +/- 2.5/76.1 +/- 2.1 vs. 128.3 +/- 4.2/79.3 +/- 2.9, de-orbit; 157.3 +/- 4.5/102.1 +/- 3.6 vs. 145.2 +/- 10.5/95.7 + 5.5, max-G; 159.6 +/- 3.9/103.7 +/- 3.3 vs. 134.1 +/- 5.1/85.7 +/- 3.1, TD). In the group with inflated anti-G suits, those who also wore the LCG exhibited significantly lower heart rates than those who did not (75.7 +/- 11.5 vs. 86.5 +/- 6.2, de-orbit; 79.5 +/- 24.8 vs. 112.1 +/- 8.7, max-G; 84.7 +/- 8.0 vs. 110.5 +/- 7.9, TD). CONCLUSIONS: The anti-G suit is effective in supporting arterial pressure. The addition of the LCG lowers heart rate during re-entry.

Augmentation of blood circulation to the fingers by warming distant body areas

NASA Technical Reports Server (NTRS)

Koscheyev, V. S.; Leon, G. R.; Paul, S.; Tranchida, D.; Linder, I. V.

2000-01-01

Future activities in space will require greater periods of time in extreme environments in which the body periphery will be vulnerable to chilling. Maintaining the hands and fingers in comfortable conditions enhances finger flexibility and dexterity, and thus effects better work performance. We have evaluated the efficacy of promoting heat transfer and release by the extremities by increasing the blood flow to the periphery from more distant parts of the body. The experimental garment paradigm developed by the investigators was used to manipulate the temperature of different body areas. Six subjects, two females and four males, were evaluated in a stage-1 baseline condition, with the inlet temperature of the circulating water in the liquid cooling/warming garment (LCWG) at 33 degrees C. At stage 2 the total LCWG water inlet temperature was cooled to 8 degrees C, and at stage 3 the inlet water temperature in specific segments of the LCWG was warmed (according to protocol) to 45 degrees C, while the inlet temperature in the rest of the LCWG was maintained at 8 degrees C. The following four body-area-warming conditions were studied in separate sessions: (1) head, (2) upper torso/arm, (3) upper torso/arm/head, and (4) legs/feet. Skin temperature, heat flux and blood perfusion of the fingers, and subjective perception of thermal sensations and overall physical comfort were assessed. Finger temperature (T(fing)) analyses showed a statistically significant condition x stage interaction. Post-hoc comparisons (T(fing)) indicated that at stage 3, the upper torso/arm/head warming condition was significantly different from the head, upper torso/arm and legs/feet conditions, showing an increase in T(fing). There was a significant increase in blood perfusion in the fingers at stage 3 in all conditions. Subjective perception of hand warmth, and overall physical comfort level significantly increased in the stage 3 upper torso/arm/head condition. The findings indicate that physiological methods to enhance heat transfer by the blood to the periphery within protective clothing provide an additional tool for increasing total and local human comfort in extreme environments.

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

PubMed

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

2015-12-01

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

Advanced Thermal Status Control of Crews in EVA and Escape Suits

NASA Astrophysics Data System (ADS)

Koscheyev, V. S.; Coca, A.; Leon, G. R.

Over the course of the manned space program, there has been an accumulation of experience on methods to control the thermal status of astronauts in open space. However, there remains a significant need for a simple method to monitor the astronaut's level of heat exchange during EVA, particularly in an emergency period, or during crew escape. The liquid cooling/warming tubing system that covers the body surface creates considerable complexity for evaluating the body's overall thermal response. Moreover, the methods used to monitor core temperature (Tc) are problematic in regard to their invasiveness and accuracy. NASA is currently attempting to develop a unified methodology for protection during EVA and crew escape that would necessarily include the control of astronaut thermal status. The findings from our research program have significant implications for solving this still-vexing problem. Our experimental paradigm centers on the assessment of thermodynamic processes with subjects donned in a specially designed symmetrically divided multi-compartment liquid cooling/warming garment consisting of 16 zones, 8 on each side of the body (hands, forearms, shoulders, torso, head, thighs, calves and feet). This garment configuration enables the study of heat exchange under nonuniform temperatures on the body surface by systematically varying the proportions of nonuniform temperatures (warm/cold) in different experimental conditions. Tc was assessed by rectal (Tr), esophageal (Tes), and ear canal temperature (Tec). Skin temperature (Tsk) was measured by a total of 26 sensors placed symmetrically on the left and right sides of the body, the main magistral vessels (carotid, brachial, femoral), and local vessel networks. We paid particular attention to the thermal status of the fingers by measuring blood perfusion, temperature (Tfing), heat flux, and thermal/comfort perception. The monitoring of Tfing and heat flux in different experimental conditions was highly informative. These indices were the first evidence of changing thermal conditions in the body, and reflected the development of a heat deficit or heat accumulation, depending on the specific experimental protocol (rest, exercise). There was a strong positive correlation between heat accumulation or deficit and Tfing (r = +0.80), and a highly significant negative correlation with Tr (r = -0.87). Standard indices of Tc, i.e., Tr, Tes, and Tec were not very accurate. Further, under exercise or extreme hot/cold environments in which there is a large amount of heat storage/dissipation from the body, the informativeness of the Tfing index degraded, likely because the maximal amount of vessel vasodilation/vasoconstriction had already occurred, and there was a restriction of blood flow through the fingers. It is important to note that these vessel/blood flow changes could also occur in space if the life support system is not responding adequately to stabilize comfort. Our findings strongly suggest that physiological parameters for Tfing and heat flux as a surveyor of comfort can be established, and that they will be reliable indices of thermal homeostasis. For Tfing, these boundaries likely range from 31.5-35.0°C for rest and exercise conditions. Outside of this range, there is a commencement of heat deficit/accumulation; to stabilize comfort, this thermal stress must be actively and forcefully restrained by countermeasures implemented through the life support system. This is particularly important in emergency situations during which thermal status information is crucial for rapidly instituting countermeasures. Because of the high sensitivity of the fingers to changing overall body thermal conditions, we propose that a finger ring with embedded sensors to monitor Tfing or heat flux intensity and establish optimal boundaries for comfort support will be highly effective in enhancing astronaut safety. This device has the potential to simplify and increase the reliability of methods for controlling the thermal status of astronauts while donned in protective suits during liftoff, EVA, and re-entry. In combination with a shortened liquid cooling/warming garment and gloves which we are developing in our laboratory, this thermal control paradigm may provide a common system that is highly responsive, lightweight, energy efficient, and unified for different stages and conditions of space flights.

Provisioning cooling elements for chillerless data centers

DOEpatents

Chainer, Timothy J.; Parida, Pritish R.

2016-12-13

Systems and methods for cooling include one or more computing structure, an inter-structure liquid cooling system that includes valves configured to selectively provide liquid coolant to the one or more computing structures; a heat rejection system that includes one or more heat rejection units configured to cool liquid coolant; and one or more liquid-to-liquid heat exchangers that include valves configured to selectively transfer heat from liquid coolant in the inter-structure liquid cooling system to liquid coolant in the heat rejection system. Each computing structure further includes one or more liquid-cooled servers; and an intra-structure liquid cooling system that has valves configured to selectively provide liquid coolant to the one or more liquid-cooled servers.

Provisioning cooling elements for chillerless data centers

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

Chainer, Timothy J.; Parida, Pritish R.

Systems and methods for cooling include one or more computing structure, an inter-structure liquid cooling system that includes valves configured to selectively provide liquid coolant to the one or more computing structures; a heat rejection system that includes one or more heat rejection units configured to cool liquid coolant; and one or more liquid-to-liquid heat exchangers that include valves configured to selectively transfer heat from liquid coolant in the inter-structure liquid cooling system to liquid coolant in the heat rejection system. Each computing structure further includes one or more liquid-cooled servers; and an intra-structure liquid cooling system that has valvesmore » configured to selectively provide liquid coolant to the one or more liquid-cooled servers.« less

Guide to Altitude Decompression Sickness Research

DTIC Science & Technology

2010-05-01

Night Vision Goggles (NVGs) and effects of hypoxia on PRK surgery recovery, F-16 APECS, F-22 Cooling Garment, U-2 Full Pressure Suit, Aircrew...1. Severity 0 No pain 1-2 Mild 3-4 Moderate 5-7 Strong 8-9 Severe 10 Strongest imaginable 2. Intermittent vs . Constant a...symptoms. 2. Intermittent vs . Constant Paresthesia a. Intermittent (Transient) is defined as lasting fewer than 60 seconds each occurrence, in a

Protective supplied breathing air garment

DOEpatents

Childers, Edward L.; von Hortenau, Erik F.

1984-07-10

A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

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

Chainer, Timothy J.; Parida, Pritish R.

Systems and methods for cooling include one or more computing structure, an inter-structure liquid cooling system that includes valves configured to selectively provide liquid coolant to the one or more computing structures; a heat rejection system that includes one or more heat rejection units configured to cool liquid coolant; and one or more liquid-to-liquid heat exchangers that include valves configured to selectively transfer heat from liquid coolant in the inter-structure liquid cooling system to liquid coolant in the heat rejection system. Each computing structure further includes one or more liquid-cooled servers; and an intra-structure liquid cooling system that has valvesmore » configured to selectively provide liquid coolant to the one or more liquid-cooled servers.« less

A Review of Aircraft Cabin Conditioning for Operations in Australia

DTIC Science & Technology

1980-10-01

Balance for Thermal Comfort 17 3.4 Liquid Conditioned Garments 18 3.5 Environmental Requirements for Electronic Equipment 19 4. THERMAL LOAD- ON AIRCRAFT...References to these two aspects are given by Nunneley and James (1977). 3.3 Physiological Heat Balance for Thermal Comfort The heat balance for thermal ...

Materials considerations in the design of a metal-hydride heat pump for an advanced extravehicular mobility unit

NASA Technical Reports Server (NTRS)

Liebert, B. E.

1986-01-01

A metal-hydride heat pump (HHP) has been proposed to provide an advanced regenerable nonventing thermal sink for the liquid-cooled garment worn during an extravehicular activity (EVA). The conceptual design indicates that there is a potential for significant advantages over the one presently being used by shuttle crew personnel as well as those that have been proposed for future use with the space station. Compared to other heat pump designs, a HHP offers the potential for extended use with no electrical power requirements during the EVA. In addition, a reliable, compact design is possible due to the absence of moving parts other than high-reliability check valves. Because there are many subtleties in the properties of metal hydrides for heat pump applications, it is essential that a prototype hydride heat pump be constructed with the selected materials before a committment is made for the final design. Particular care must be given to the evaporator heat exchanger worn by the astronaut since the performance of hydride heat pumps is generally heat transfer limited.

Synthesis and characterization of polymer layers for control of fluid transport

NASA Astrophysics Data System (ADS)

Vatansever, Fehime

The level of wetting of fiber surface with liquids is an important characteristic of fibrous materials. It is related to fiber surface energy and the structure of the material. Surface energy can be changed by surface modification via the grafting methodologies that have been reported for introducing new and stable functionality to fibrous substrates without changing bulk properties. Present work is dedicated to synthesis and characterization of macromolecular layers grafted to fiber surface in order to achieve directional liquid transport for the modified fabric. Modification technique used here is based on formation of stable polymer layer on fabric surface using "grafting to" technique. Specifically, modification of fabric with wettability gradient for facilitated one way-liquid transport, and pointed modification of yarn-based channels on textile microfluidic device for directional liquid transport are reported here. First, fabric was activated with alkali (NaOH) solution. Second, poly (glycidyl methacrylate) (PGMA) was deposited on fabric as an anchoring layer. Finally, polymers of interest were grafted to surface through the epoxy functionality of PGMA. Effect of polymer grafting on the wicking property of the fabric has been evaluated by vertical wicking technique at the each step of surface modification. The results shows that wicking performance of fabric can be altered by grafting of a thin nanoscale polymeric film. For the facilitated liquid transport, the gradient polymer coating was created using "grafting to" technique and its dependence on the grafting temperature. Wettability gradient from hydrophilic to hydrophobic (change in water contact angle from 0 to 140 degrees on fabric) was achieved by grafting of polystyrene (PS) and polyacrylic acid (PAA) sequentially with concentration gradient. This study proposes that fabric with wettability gradient property can be used to transfer sweat from skin and support moisture management when it is used in a laminated garment structure. For cooling performance evaluation, modified fabrics were tested with surface differential scanning calorimeter, and improved cooling effect was found with the fabric that has wettability gradient. Directional liquid transport can be achieved on amphiphilic fabric. To this end, fabric consisting of PET and PP yarn is fabricated. Activation and PGMA deposition yields an array of highly reactive PET channels that are constrained by hydrophobic PP boundaries. Aqueous solutions are transported in the channels by capillary forces where the direction of the liquid transport is defined by pH-response of the grafted polymers. The system of pH-selective channels in the developed textile based microfluidic chip could find analytical applications and can be used for smart cloth.

Evaluation of Foam Coolants.

DTIC Science & Technology

HYPERGOLIC ROCKET PROPELLANTS, * FOAM , FILM COOLING, FILM COOLING, LIQUID COOLING, LIQUID ROCKET FUELS, ADDITIVES, HEAT TRANSFER, COOLANTS, LIQUID PROPELLANT ROCKET ENGINES, LIQUID COOLING, CAPTIVE TESTS, FEASIBILITY STUDIES.

Thermal management of liquid direct cooled split disk laser

NASA Astrophysics Data System (ADS)

Yang, Huomu; Feng, Guoying; Zhou, Shouhuan

2015-02-01

The thermal effects of a liquid direct cooled split disk laser are modeled and analytically solved. The analytical solutions with the consideration of longitudinal cooling liquid temperature rise have been given to describe the temperature distribution in the split disk and cooling liquid based on the hydrodynamics and heat transfer. The influence of cooling liquid, liquid flowing velocity, thickness of cooling channel and of disk gain medium can also be got from the analytical solutions.

Thermoelectric-enhanced, liquid-based cooling of a multi-component electronic system

DOEpatents

Chainer, Timothy J; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E

2015-11-10

Methods are provided for facilitating cooling of an electronic component. The methods include providing: a liquid-cooled structure, a thermal conduction path coupling the electronic component and the liquid-cooled structure, a coolant loop in fluid communication with a coolant-carrying channel of the liquid-cooled structure, and an outdoor-air-cooled heat exchange unit coupled to facilitate heat transfer from the liquid-cooled structure via, at least in part, the coolant loop. The thermoelectric array facilitates transfer of heat from the electronic component to the liquid-cooled structure, and the heat exchange unit cools coolant passing through the coolant loop by dissipating heat from the coolant to outdoor ambient air. In one implementation, temperature of coolant entering the liquid-cooled structure is greater than temperature of the outdoor ambient air to which heat is dissipated.

Thermoelectric-enhanced, liquid-based cooling of a multi-component electronic system

DOEpatents

Chainer, Timothy J; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E

2015-05-12

Apparatus and method are provided for facilitating cooling of an electronic component. The apparatus includes a liquid-cooled structure, a thermal conduction path coupling the electronic component and the liquid-cooled structure, a coolant loop in fluid communication with a coolant-carrying channel of the liquid-cooled structure, and an outdoor-air-cooled heat exchange unit coupled to facilitate heat transfer from the liquid-cooled structure via, at least in part, the coolant loop. The thermoelectric array facilitates transfer of heat from the electronic component to the liquid-cooled structure, and the heat exchange unit cools coolant passing through the coolant loop by dissipating heat from the coolant to outdoor ambient air. In one implementation, temperature of coolant entering the liquid-cooled structure is greater than temperature of the outdoor ambient air to which heat is dissipated.

Data center cooling system

DOEpatents

Chainer, Timothy J; Dang, Hien P; Parida, Pritish R; Schultz, Mark D; Sharma, Arun

2015-03-17

A data center cooling system may include heat transfer equipment to cool a liquid coolant without vapor compression refrigeration, and the liquid coolant is used on a liquid cooled information technology equipment rack housed in the data center. The system may also include a controller-apparatus to regulate the liquid coolant flow to the liquid cooled information technology equipment rack through a range of liquid coolant flow values based upon information technology equipment temperature thresholds.

Floating Loop System For Cooling Integrated Motors And Inverters Using Hot Liquid Refrigerant

DOEpatents

Hsu, John S [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Coomer, Chester [Knoxville, TN; Marlino, Laura D [Oak Ridge, TN

2006-02-07

A floating loop vehicle component cooling and air-conditioning system having at least one compressor for compressing cool vapor refrigerant into hot vapor refrigerant; at least one condenser for condensing the hot vapor refrigerant into hot liquid refrigerant by exchanging heat with outdoor air; at least one floating loop component cooling device for evaporating the hot liquid refrigerant into hot vapor refrigerant; at least one expansion device for expanding the hot liquid refrigerant into cool liquid refrigerant; at least one air conditioning evaporator for evaporating the cool liquid refrigerant into cool vapor refrigerant by exchanging heat with indoor air; and piping for interconnecting components of the cooling and air conditioning system.

Biomedical Support of U.S. Extravehicular Activity

NASA Technical Reports Server (NTRS)

Gernhardt, Michael L.; Dervay, J. P.; Gillis, D.; McMann, H. J.; Thomas, K. S.

2007-01-01

The world's first extravehicular activity (EVA) was performed by A. A. Leonov on March 18, 1965 during the Russian Voskhod-2 mission. The first US EVA was executed by Gemini IV astronaut Ed White on June 3, 1965, with an umbilical tether that included communications and an oxygen supply. A hand-held maneuvering unit (HHMU) also was used to test maneuverability during the brief EVA; however the somewhat stiff umbilical limited controlled movement. That constraint, plus difficulty returning through the vehicle hatch, highlighted the need for increased thermal control and improved EVA ergonomics. Clearly, requirements for a useful EVA were interrelated with the vehicle design. The early Gemini EVAs generated requirements for suits providing micro-meteor protection, adequate visual field and eye protection from solar visual and infrared radiation, gloves optimized for dexterity while pressurized, and thermal systems capable of protecting the astronaut while rejecting metabolic heat during high workloads. Subsequent Gemini EVAs built upon this early experience and included development of a portable environmental control and life support systems (ECLSS) and an astronaut maneuvering unit. The ECLSS provided a pressure vessel and controller with functional control over suit pressure, oxygen flow, carbon dioxide removal, humidity, and temperature control. Gemini EVA experience also identified the usefulness of underwater neutral buoyancy and altitude chamber task training, and the importance of developing reliable task timelines. Improved thermal management and carbon dioxide control also were required for high workload tasks. With the Apollo project, EVA activity was primarily on the lunar surface; and suit durability, integrated liquid cooling garments, and low suit operating pressures (3.75 pounds per square inch absolute [psia] or 25.8 kilopascal [kPa],) were required to facilitate longer EVAs with ambulation and significant physical workloads with average metabolic rates of 1000 BTU/hr and peaks of up to 2200 BTU/hr. Mobility was further augmented with the Lunar Roving Vehicle. The Apollo extravehicular mobility unit (EMU) was made up of over 15 components, ranging from a biomedical belt for capturing and transmitting biomedical data, urine and fecal containment systems, a liquid cooling garment, communications cap, a modular portable life support system (PLSS), a boot system, thermal overgloves, and a bubble helmet with eye protection. Apollo lunar astronauts performed successful EVAs on the lunar surface from a 5 psia (34.4 kPa) 100% oxygen environment in the Lunar Lander. A maximum of three EVAs were performed on any mission. For Skylab a modified A7LB suit, used for Apollo 15, was selected. The Skylab astronaut life support assembly (ALSA) provided umbilical support through the life support umbilical (LSU) and used open loop oxygen flow, rather than closed-loop as in Apollo missions. Thermal control was provided by liquid water circulated by spacecraft pumps and electrical power also was provided from the spacecraft via the umbilical. The cabin atmosphere of 5 psia (34.4 kPa), 70% oxygen, provided a normoxic atmosphere and because of the very low nitrogen partial pressures, no special protocols were required to protect against decompression sickness (DCS) as was the case with the Apollo spacecraft with a 5 psi, 100% oxygen environment.

High-Performance Computing Data Center Warm-Water Liquid Cooling |

Science.gov Websites

Computational Science | NREL Warm-Water Liquid Cooling High-Performance Computing Data Center Warm-Water Liquid Cooling NREL's High-Performance Computing Data Center (HPC Data Center) is liquid water Liquid cooling technologies offer a more energy-efficient solution that also allows for effective

Protective supplied breathing air garment

DOEpatents

Childers, E.L.; Hortenau, E.F. von.

1984-07-10

A breathing air garment is disclosed for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap. 17 figs.

Gradient Compression Garments as a Countermeasure to Post-Space Flight Orthostatic Intolerance: Potential Interactions with the Maximum Absorbency Garment

NASA Technical Reports Server (NTRS)

Lee, S. M. C.; Laurie, S. S.; Macias, B. R.; Willig, M.; Johnson, K.; Stenger, M. B.

2017-01-01

Astronauts and cosmonauts may experience symptoms of orthostatic intolerance during re-entry, landing, and for several days post-landing following short- and long-duration spaceflight. Presyncopal symptoms have been documented in approximately 20% of short-duration and greater than 60% of long-duration flyers on landing day specifically during 5-10 min of controlled (no countermeasures employed at the time of testing) stand tests or 80 deg head-up tilt tests. Current operational countermeasures to orthostatic intolerance include fluid loading prior to and whole body cooling during re-entry as well as compression garments that are worn during and for up to several days after landing. While both NASA and the Russian space program have utilized compression garments to protect astronauts and cosmonauts traveling on their respective vehicles, a "next-generation" gradient compression garment (GCG) has been developed and tested in collaboration with a commercial partner to support future space flight missions. Unlike previous compression garments used operationally by NASA that provide a single level of compression across only the calves, thighs, and lower abdomen, the GCG provides continuous coverage from the feet to below the pectoral muscles in a gradient fashion (from approximately 55 mm Hg at the feet to approximately 16 mmHg across the abdomen). The efficacy of the GCG has been demonstrated previously after a 14-d bed rest study without other countermeasures and after short-duration Space Shuttle missions. Currently the GCG is being tested during a stand test following long-duration missions (6 months) to the International Space Station. While results to date have been promising, interactions of the GCG with other space suit components have not been examined. Specifically, it is unknown whether wearing the GCG over NASA's Maximum Absorbency Garment (MAG; absorbent briefs worn for the collection of urine and feces while suited during re-entry and landing) will interfere with the effectiveness of the GCG or conversely whether the GCG will reduce the fluid absorption capabilities of the MAG. Methods: This operational, directed study, will (1) determine whether the effectiveness of the GCG is affected by the MAG with regard to cardiovascular responses to head-up tilt, the standard orthostatic intolerance test employed for astronauts and bed rest subjects; (2) determine whether the effectiveness of the MAG is compromised by the GCG tested by injecting a standard fluid volume (950 ml in 3 separate simulated "urine voids") at a standardized rate (30 ml/sec); and (3) determine whether comfort is affected by wearing the MAG under the GCG using a standardized questionnaire. Results from this study will guide future development and operational use of the GCG and MAG to maximize crew health, safety, and comfort.

Helmet Exhalation Capture System (HECS) Sizing Evaluation for an Advanced Space Suit Portable Life Support System

NASA Technical Reports Server (NTRS)

Paul, Heather L.; Waguespack, Glenn M.; Paul, Thomas H.; Conger, Bruce C.

2008-01-01

As part of NASA s initiative to develop an advanced portable life support system (PLSS), a baseline schematic has been chosen that includes gaseous oxygen in a closed circuit ventilation configuration. Supply oxygen enters the suit at the back of the helmet and return gases pass over the astronaut s body to be extracted at the astronaut s wrists and ankles through the liquid cooling and ventilation garment (LCVG). The extracted gases are then treated using a rapid cycling amine (RCA) system for carbon dioxide and water removal and activated carbon for trace gas removal before being mixed with makeup oxygen and reintroduced into the helmet. Thermal control is provided by a suit water membrane evaporator (SWME). As an extension of the original schematic development, NASA evaluated several Helmet Exhalation Capture System (HECS) configurations as alternatives to the baseline. The HECS configurations incorporate the use of full contact masks or non-contact masks to reduce flow requirements within the PLSS ventilation subsystem. The primary scope of this study was to compare the alternatives based on mass and volume considerations; however other design issues were also briefly investigated. This paper summarizes the results of this sizing analysis task.

Thermoregulatory models of safety-for-flight issues for space operations

NASA Astrophysics Data System (ADS)

Pisacane, V. L.; Kuznetz, L. H.; Logan, J. S.; Clark, J. B.; Wissler, E. H.

2006-10-01

This study investigates the use of a mathematical model for thermoregulation as a tool in safety-of-flight issues and proposed solutions for mission operations of the Space Shuttle and the International Space Station. Specifically, this study assesses the effects of elevated cabin temperature and metabolic loads on astronauts wearing the Advanced Crew Escape Suit (ACES) and the Liquid Cooled Ventilation Garment (LCVG). The 225-node Wissler model is validated by comparison with two ground-based human subject tests, firefighters, and surrogate astronauts under anomalous conditions that show good agreement. Subsequent simulations indicate that the performance of the ACES/LCVG is marginal. Increases in either workload or cabin temperature from the nominal will increase rectal temperature, stored heat load, heart rate, and sweating leading to possible deficits in the ability of the astronauts to perform cognitive and motor tasks that could affect the safety of the mission, especially the safe landing of the Shuttle. Specific relationships are given between cabin temperature and metabolic rate that define the threshold for decreased manual dexterity and loss of tracking skills. Model results indicate that the most effective mitigation strategy would be to decrease the LCVG inlet temperature. Methods of accomplishing this are also proposed.

Seminar 14 - Desiccant Enhanced Air Conditioning: Desiccant Enhanced Evaporative Air Conditioning (Presentation)

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

Kozubal, E.

2013-02-01

This presentation explains how liquid desiccant based coupled with an indirect evaporative cooler can efficiently produce cool, dry air, and how a liquid desiccant membrane air conditioner can efficiently provide cooling and dehumidification without the carryover problems of previous generations of liquid desiccant systems. It provides an overview to a liquid desiccant DX air conditioner that can efficiently provide cooling and dehumidification to high latent loads without the need for reheat, explains how liquid desiccant cooling and dehumidification systems can outperform vapor compression based air conditioning systems in hot and humid climates, explains how liquid desiccant cooling and dehumidification systemsmore » work, and describes a refrigerant free liquid desiccant based cooling system.« less

V-SUIT Model Validation Using PLSS 1.0 Test Results

NASA Technical Reports Server (NTRS)

Olthoff, Claas

2015-01-01

The dynamic portable life support system (PLSS) simulation software Virtual Space Suit (V-SUIT) has been under development at the Technische Universitat Munchen since 2011 as a spin-off from the Virtual Habitat (V-HAB) project. The MATLAB(trademark)-based V-SUIT simulates space suit portable life support systems and their interaction with a detailed and also dynamic human model, as well as the dynamic external environment of a space suit moving on a planetary surface. To demonstrate the feasibility of a large, system level simulation like V-SUIT, a model of NASA's PLSS 1.0 prototype was created. This prototype was run through an extensive series of tests in 2011. Since the test setup was heavily instrumented, it produced a wealth of data making it ideal for model validation. The implemented model includes all components of the PLSS in both the ventilation and thermal loops. The major components are modeled in greater detail, while smaller and ancillary components are low fidelity black box models. The major components include the Rapid Cycle Amine (RCA) CO2 removal system, the Primary and Secondary Oxygen Assembly (POS/SOA), the Pressure Garment System Volume Simulator (PGSVS), the Human Metabolic Simulator (HMS), the heat exchanger between the ventilation and thermal loops, the Space Suit Water Membrane Evaporator (SWME) and finally the Liquid Cooling Garment Simulator (LCGS). Using the created model, dynamic simulations were performed using same test points also used during PLSS 1.0 testing. The results of the simulation were then compared to the test data with special focus on absolute values during the steady state phases and dynamic behavior during the transition between test points. Quantified simulation results are presented that demonstrate which areas of the V-SUIT model are in need of further refinement and those that are sufficiently close to the test results. Finally, lessons learned from the modelling and validation process are given in combination with implications for the future development of other PLSS models in V-SUIT.

Use of once-through treat gas to remove the heat of reaction in solvent hydrogenation processes

DOEpatents

Nizamoff, Alan J.

1980-01-01

In a coal liquefaction process wherein feed coal is contacted with molecular hydrogen and a hydrogen-donor solvent in a liquefaction zone to form coal liquids and vapors and coal liquids in the solvent boiling range are thereafter hydrogenated to produce recycle solvent and liquid products, the improvement which comprises separating the effluent from the liquefaction zone into a hot vapor stream and a liquid stream; cooling the entire hot vapor stream sufficiently to condense vaporized liquid hydrocarbons; separating condensed liquid hydrocarbons from the cooled vapor; fractionating the liquid stream to produce coal liquids in the solvent boiling range; dividing the cooled vapor into at least two streams; passing the cooling vapors from one of the streams, the coal liquids in the solvent boiling range, and makeup hydrogen to a solvent hydrogenation zone, catalytically hydrogenating the coal liquids in the solvent boiling range and quenching the hydrogenation zone with cooled vapors from the other cooled vapor stream.

The impact of design variables and aftercare regime on the long-term performance of pressure garments.

PubMed

Macintyre, Lisa; Gilmartin, Sian; Rae, Michelle

2007-01-01

We sought to establish the impact of pressure garment design variables, moisturizer use, and laundry method on the ability of pressure garments to maintain their pressure delivering potential, indicated here by garment tension, over time and use. Twenty-six sets of three replicate pressure garment sleeves were constructed from four powernet fabrics, using three reduction factors and six sleeve dimensions. These pressure garment sleeves were extended for 23 hours on static cylinder models followed by hand or machine laundry up to 28 times. Some sleeves were additionally exposed to moisturizers during their extension. Garment tension and dimensions were measured before and during the simulated wear and wash period to indicate each garment's ability to maintain its tension and therefore pressure throughout a period of "use." The results of the investigation were analyzed in groups where each group contained only 1 variable, thereby allowing the variables with the most significant impact on tension degradation to be identified. The investigation confirmed that all pressure garments lost tension and therefore pressure delivering ability over time and use. It further revealed that pressure garments designed to exert greater pressures degraded faster than those designed to exert lower pressures. Contact between pressure garments and moisturizers accelerated tension degradation, and machine-washing pressure garments tended to prolong their pressure-delivering properties compared with hand-washing them. To maintain the initial pressure delivered by pressure garments, powernet fabrics should be prestressed before being designed/constructed and they should be machine-washed by patients.

Space Shuttle Hot Cabin Emergency Responses

NASA Technical Reports Server (NTRS)

Stepaniak, P.; Effenhauser, R. K.; McCluskey, R.; Gillis, D. B.; Hamilton, D.; Kuznetz, L. H.

2005-01-01

Methods: Human thermal tolerance, countermeasures, and thermal model data were reviewed and compared to existing shuttle ECS failure temperature and humidity profiles for each failure mode. Increases in core temperature associated with cognitive impairment was identified, as was metabolic heat generation of crewmembers, temperature monitoring, and communication capabilities after partial power-down and other limiting factors. Orbiter landing strategies and a hydration and salt replacement protocol were developed to put wheels on deck in each failure mode prior to development of significant cognitive impairment or collapse of crewmembers. Thermal tradeoffs for use of the Advanced Crew Escape Suit (ACES), Liquid Cooling Garment, integrated G-suit and Quick Don Mask were examined. candidate solutions involved trade-offs or conflicts with cabin oxygen partial pressure limits, system power-downs to limit heat generation, risks of alternate and emergency landing sites or compromise of Mode V-VIII scenarios. Results: Rehydration and minimized cabin workloads are required in all failure modes. Temperature/humidity profiles increase rapidly in two failure modes, and deorbit is recommended without the ACES, ICU and g-suit. This latter configuration limits several shuttle approach and landing escape modes and requires communication modifications. Additional data requirements were identified and engineering simulations were recommended to develop more current shuttle temperature and humidity profiles. Discussion: After failure of the shuttle ECS, there is insufficient cooling capacity of the ACES to protect crewmembers from rising cabin temperature and humidity. The LCG is inadequate for cabin temperatures above 76 F. Current shuttle future life policy makes it unlikely that major engineering upgrades necessary to address this problem will occur.

Metal hydride heat pump engineering demonstration and evaluation model

NASA Technical Reports Server (NTRS)

Lynch, Franklin E.

1993-01-01

Future generations of portable life support systems (PLSS's) for space suites (extravehicular mobility units or EMU's) may require regenerable nonventing thermal sinks (RNTS's). For purposes of mobility, a PLSS must be as light and compact as possible. Previous venting PLSS's have employed water sublimators to reject metabolic and equipment heat from EMU's. It is desirable for long-duration future space missions to minimize the use of water and other consumables that need to be periodically resupplied. The emission of water vapor also interferes with some types of instrumentation that might be used in future space exploration. The test article is a type of RNTS based on a metal hydride heat pump (MHHP). The task of reservicing EMU's after use must be made less demanding in terms of time, procedures, and equipment. The capability for quick turnaround post-EVA servicing (30 minutes) is a challenging requirement for many of the RNTS options. The MHHP is a very simple option that can be regenerated in the airlock within the 30 minute limit by the application of a heating source and a cooling sink. In addition, advanced PLSS's must provide a greater degree of automatic control, relieving astronauts of the need to manually adjust temperatures in their liquid cooled ventilation garments (LCVG's). The MHHP includes automatic coolant controls with the ability to follow thermal load swings from minimum to maximum in seconds. The MHHP includes a coolant loop subsystem with pump and controls, regeneration equipment for post-EVA servicing, and a PC-based data acquisition and control system (DACS).

Methods for forming wellbores in heated formations

DOEpatents

Guimerans, Rosalvina Ramona; Mansure, Arthur James

2012-09-25

A method for forming a wellbore in a heated formation includes flowing liquid cooling fluid to a bottom hole assembly in a wellbore in a heated formation. At least a portion of the liquid cooling fluid is vaporized at or near a region to be cooled. Vaporizing the liquid cooling fluid absorbs heat from the region to be cooled.

Simulation Studies on Cooling of Cryogenic Propellant by Gas Bubbling

NASA Astrophysics Data System (ADS)

Sandilya, Pavitra; Saha, Pritam; Sengupta, Sonali

Injection cooling was proposed to store cryogenic liquids (Larsen et al. [1], Schmidt [2]). When a non-condensable gas is injected through a liquid, the liquid component would evaporate into the bubble if its partial pressure in the bubble is lower than its vapour pressure. This would tend to cool the liquid. Earlier works on injection cooling was analysed by Larsen et al. [1], Schmidt [2], Cho et al. [3] and Jung et al. [4], considering instantaneous mass transfer and finite heat transfer between gas bubble and liquid. It is felt that bubble dynamics (break up, coalescence, deformation, trajectory etc.) should also play a significant role in liquid cooling. The reported work are based on simple assumptions like single bubble, zero bubble deformation, and no inter-bubble interactions. Hence in this work, we propose a lumped parameter model considering both heat and mass interactions between bubble and the liquid to gain a preliminary insight into the cooling phenomenon during gas injection through a liquid.

Ghanaian Women's Perceptions of the Quality of Ready-to-Wear Garments

ERIC Educational Resources Information Center

Fianu, Docea A. G.; Aryee-Atta, Salome N. A.

2008-01-01

Women can choose among many options with regard to ready-to-wear (RTW) clothing; for example, they can purchase imported or domestically produced garments, or they can select custom-made or second-hand garments. In Ghana, women have traditionally preferred imported RTW garments to RTW garments produced within the country. In this study,…

An Enhanced Personal Cooling Garment for Aircrew

DTIC Science & Technology

2002-04-01

Thermal Comfort Thermal comfort was rated by the subject on a scale of 1 (so cold I am helpless) to 13 (so hot I am...0- N-EC ~25 0 -25 -50 - 0 30 60 90 120 150 180 Time (min) Figure 6 - Mean Heat Flow (uncooled sites) Rating of Thermal Comfort Ratings of thermal ... comfort for group C and N are shown in Figure 7. 12 SC-AC 11 9• C-EC 6--- 5 4 3- 0 30 60 90 120 150 180 Time (min) Figure 7 - Rating of Thermal Comfort

Cycles in metabolism and heat loss

NASA Technical Reports Server (NTRS)

Annis, J. F.; Troutman, S. J.; Webb, P.

1974-01-01

Using calorimetric techniques, subjects' metabolism, thermoregulation, and body temperatures were monitored continuously for 24-hour days, using three types of experimental routines. A water cooling garment (WCG) was used for direct calorimetry, while partitional calorimetry was used to establish a non-suited comparison for one of the routines. In this replicated routine, called the quiet day, the subjects were sedentary throughout the daytime hours and slept normally at night. Results indicate that the WCG may act to reduce 24-hour total oxygen consumption (VO2) or heat production, possibly due to the lowered energy cost of thermoregulation.

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

Chen, Dafen; Jiang, Jiuchun; Kim, Gi-Heon

Choosing a proper cooling method for a lithium-ion (Li-ion) battery pack for electric drive vehicles (EDVs) and making an optimal cooling control strategy to keep the temperature at a optimal range of 15 degrees C to 35 degrees C is essential to increasing safety, extending the pack service life, and reducing costs. When choosing a cooling method and developing strategies, trade-offs need to be made among many facets such as costs, complexity, weight, cooling effects, temperature uniformity, and parasitic power. This paper considers four cell-cooling methods: air cooling, direct liquid cooling, indirect liquid cooling, and fin cooling. To evaluate theirmore » effectiveness, these methods are assessed using a typical large capacity Li-ion pouch cell designed for EDVs from the perspective of coolant parasitic power consumption, maximum temperature rise, temperature difference in a cell, and additional weight used for the cooling system. We use a state-of-the-art Li-ion battery electro-chemical thermal model. The results show that under our assumption an air-cooling system needs 2 to 3 more energy than other methods to keep the same average temperature; an indirect liquid cooling system has the lowest maximum temperature rise; and a fin cooling system adds about 40% extra weight of cell, which weighs most, when the four kinds cooling methods have the same volume. Indirect liquid cooling is a more practical form than direct liquid cooling though it has slightly lower cooling performance.« less

Review and status of liquid-cooling technology for gas turbines

NASA Technical Reports Server (NTRS)

Vanfossen, G. J., Jr.; Stepka, F. S.

1979-01-01

A review was conducted of liquid-cooled turbine technology. Selected liquid-cooled systems and methods are presented along with an assessment of the current technology status and requirements. A comprehensive bibliography is presented.

NREL, LiquidCool Solutions Partner on Energy-Efficient Cooling for

Science.gov Websites

denser and generate more heat. Liquid cooling, including the LiquidCool Solutions technology, offers a more energy-efficient solution that also allows for effective reuse of the heat rejected by the water, depending on the coolant temperature and heat exchanger specifications. These water temperatures

Space Suit Portable Life Support System (PLSS) 2.0 Human-in-the-Loop (HITL) Testing

NASA Technical Reports Server (NTRS)

Watts, Carly; Vogel, Matthew

2016-01-01

The space suit Portable Life Support System (PLSS) 2.0 represents the second integrated prototype developed and tested to mature a design that uses advanced technologies to reduce consumables, improve robustness, and provide additional capabilities over the current state of the art. PLSS 2.0 was developed in 2012, with extensive functional evaluations and system performance testing through mid-2014. In late 2014, PLSS 2.0 was integrated with the Mark III space suit in an ambient laboratory environment to facilitate manned testing, designated PLSS 2.0 Human-in-the-Loop (HITL) testing, in which the PLSS prototype performed the primary life support functions, including suit pressure regulation, ventilation, carbon dioxide control, and cooling of the test subject and PLSS avionics. The intent of this testing was to obtain subjective test subject feedback regarding qualitative aspects of PLSS 2.0 performance such as thermal comfort, sounds, smells, and suit pressure fluctuations due to the cycling carbon dioxide removal system, as well as to collect PLSS performance data over a range of human metabolic rates from 500-3000 Btu/hr. Between October 27 and December 18, 2014, nineteen two-hour simulated EVA test points were conducted in which suited test subjects walked on a treadmill to achieve a target metabolic rate. Six test subjects simulated nominal and emergency EVA conditions with varied test parameters including metabolic rate profile, carbon dioxide removal control mode, cooling water temperature, and Liquid Cooling and Ventilation Garment (state of the art or prototype). The nineteen test points achieved more than 60 hours of test time, with 36 hours accounting for simulated EVA time. The PLSS 2.0 test article performed nominally throughout the test series, confirming design intentions for the advanced PLSS. Test subjects' subjective feedback provided valuable insight into thermal comfort and perceptions of suit pressure fluctuations that will influence future advanced PLSS design and testing strategies.

Liquid metal cooled nuclear reactor plant system

DOEpatents

Hunsbedt, Anstein; Boardman, Charles E.

1993-01-01

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting for fuel decay during reactor shutdown, or heat produced during a mishap. The reactor system is enhanced with sealing means for excluding external air from contact with the liquid metal coolant leaking from the reactor vessel during an accident. The invention also includes a silo structure which resists attack by leaking liquid metal coolant, and an added unique cooling means.

Magnetic suspension using high temperature superconducting cores

NASA Technical Reports Server (NTRS)

Scurlock, R. G.

1992-01-01

The development of YBCO high temperature superconductors, in wire and tape forms, is rapidly approaching the point where the bulk transport current density j vs magnetic field H characteristics with liquid nitrogen cooling will enable its use in model cores. On the other hand, BSCCO high temperature superconductor in wire form has poor j-H characteristics at 77 K today, although with liquid helium or hydrogen cooling, it appears to be superior to NbTi superconductor. Since liquid nitrogen cooling is approx. 100 times cheaper than liquid helium cooling, the use of YBCO is very attractive for use in magnetic suspension. The design is discussed of a model core to accommodate lift and drag loads up to 6000 and 3000 N respectively. A comparison is made between the design performance of a liquid helium cooled NbTi (or BSCCO) superconducting core and a liquid nitrogen cooled YBCO superconducting core.

Method and apparatus of cryogenic cooling for high temperature superconductor devices

DOEpatents

Yuan, Xing; Mine, Susumu

2005-02-15

A method and apparatus for providing cryogenic cooling to HTS devices, in particular those that are used in high-voltage electric power applications. The method involves pressurizing liquid cryogen to above one atmospheric pressure to improve its dielectric strength, while sub-cooling the liquid cryogen to below its saturation temperature in order to improve the performance of the HTS components of the device. An apparatus utilizing such a cooling method consists of a vessel that contains a pressurized gaseous cryogen region and a sub-cooled liquid cryogen bath, a liquid cryogen heating coupled with a gaseous cryogen venting scheme to maintain the pressure of the cryogen to a value in a range that corresponds to optimum dielectric strength of the liquid cryogen, and a cooling system that maintains the liquid cryogen at a temperature below its boiling point to improve the performance of HTS materials used in the device.

High-Efficiency Helical Coil Electromagnetic Launcher and High Power Hall-Effect Switch

DTIC Science & Technology

2008-02-29

also given that demonstrate significant launcher performance benefits by super-cooling the armature (i.e., using liquid nitrogen ). 14. ABSTRACT... liquid nitrogen temperatures). A computer model for a magnetically-controlled Hall-effect switch is developed. The model is constructed in the PSpice...of super-cooling is demonstrated with liquid nitrogen cooling and indicates super-cooled EML operation is desirable if cryo-cooling is practical for

Liquid rocket engine fluid-cooled combustion chambers

NASA Technical Reports Server (NTRS)

1972-01-01

A monograph on the design and development of fluid cooled combustion chambers for liquid propellant rocket engines is presented. The subjects discussed are (1) regenerative cooling, (2) transpiration cooling, (3) film cooling, (4) structural analysis, (5) chamber reinforcement, and (6) operational problems.

Liquid metal cooled nuclear reactors with passive cooling system

DOEpatents

Hunsbedt, Anstein; Fanning, Alan W.

1991-01-01

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of cooling medium flow circuits which cooperate to remove and carry heat away from the fuel core upon loss of the normal cooling flow circuit to areas external thereto.

Effect of Compression Garments on Physiological Responses After Uphill Running.

PubMed

Struhár, Ivan; Kumstát, Michal; Králová, Dagmar Moc

2018-03-01

Limited practical recommendations related to wearing compression garments for athletes can be drawn from the literature at the present time. We aimed to identify the effects of compression garments on physiological and perceptual measures of performance and recovery after uphill running with different pressure and distributions of applied compression. In a random, double blinded study, 10 trained male runners undertook three 8 km treadmill runs at a 6% elevation rate, with the intensity of 75% VO2max while wearing low, medium grade compression garments and high reverse grade compression. In all the trials, compression garments were worn during 4 hours post run. Creatine kinase, measurements of muscle soreness, ankle strength of plantar/dorsal flexors and mean performance time were then measured. The best mean performance time was observed in the medium grade compression garments with the time difference being: medium grade compression garments vs. high reverse grade compression garments. A positive trend in increasing peak torque of plantar flexion (60º·s-1, 120º·s-1) was found in the medium grade compression garments: a difference between 24 and 48 hours post run. The highest pain tolerance shift in the gastrocnemius muscle was the medium grade compression garments, 24 hour post run, with the shift being +11.37% for the lateral head and 6.63% for the medial head. In conclusion, a beneficial trend in the promotion of running performance and decreasing muscle soreness within 24 hour post exercise was apparent in medium grade compression garments.

Liquid cooled counter flow turbine bucket

DOEpatents

Dakin, James T.

1982-09-21

Means and a method are provided whereby liquid coolant flows radially outward through coolant passages in a liquid cooled turbine bucket under the influence of centrifugal force while in contact with countercurrently flowing coolant vapor such that liquid is entrained in the flow of vapor resulting in an increase in the wetted cooling area of the individual passages.

Data center cooling method

DOEpatents

Chainer, Timothy J.; Dang, Hien P.; Parida, Pritish R.; Schultz, Mark D.; Sharma, Arun

2015-08-11

A method aspect for removing heat from a data center may use liquid coolant cooled without vapor compression refrigeration on a liquid cooled information technology equipment rack. The method may also include regulating liquid coolant flow to the data center through a range of liquid coolant flow values with a controller-apparatus based upon information technology equipment temperature threshold of the data center.

Clothing creator trademark : Business plan

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

Stern, B.

SYMAGERY has developed a patented process to manufacture clothing without direct human labor. This CLOTHING CREATOR{trademark}, will have the ability to produce two (2) perfect garments every 45 seconds or one (1) every 30 seconds. The process will combine Computer Integrated Manufacturing (CIM) technology with heat molding and ultrasonic bonding/cutting techniques. This system for garment production, will have the capacity to produce garments of higher quality and at lower productions costs than convention cut and sew methods. ADVANTAGES of the process include: greatly reduced production costs; increased quality of garments; reduction in lead time; and capacity to make new classmore » of garments. This technology will accommodate a variety of knit, woven and nonwoven materials containing a majority of synthetic fibers. Among the many style of garments that could be manufactured by this process are: work clothing, career apparel, athletic garments, medical disposables, health care products, activewear, haz/mat garments, military clothing, cleanroom clothing, outdoor wear, upholstery, and highly contoured stuffed toy shells. 3 refs.« less

Thermal Conductivity of Polymer Copoly(Ethylene Vinyl Acetate)/Nano-Filler Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Lin, Y.; Sun, Y. P.

2007-01-01

The development of flexible, thermally conductive fabrics and plastic tubes for the Liquid Cooling and Ventilation Garment (LCVG) are needed to reduce weight and improve the mobility, comfort, and performance of future spacesuits. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As a continuation of our work on the improvement of thermal conductivity (TC) of polymeric materials, nanocomposites were prepared from copoly(ethylene vinyl acetate), trade name Elvax 260 , metallized carbon nanofibers (CNFs), nickel (Ni) nanostrands, boron nitride both alone and as mixtures with aluminum powder. The nanocomposites were prepared by melt mixing at various loading levels and subsequently fabricated into several material forms (i.e., ribbons, tubes, and compression molded plaques) for analysis. Ribbons and tubes were extruded to form samples in which the nanoparticles were aligned in the direction of flow. The degree of dispersion and alignment of the nanoparticles were investigated using high-resolution scanning electron microscopy. Tensile properties of the aligned samples were determined at room temperature. TC measurements were performed using a laser flash (Nanoflash ) technique. The TC of the samples was measured in both the direction of alignment as well as transverse. Tubing of comparable dimensions to that used in the LCVG was extruded from select compositions and the thermal conductivities of the tubes measured.

Innovation Incubator: LiquidCool Solutions Technical Evaluation. Laboratory Study and Demonstration Results of a Directed-Flow, Liquid Submerged Server for High-Efficiency Data Centers

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

Kozubal, Eric J

LiquidCool Solutions (LCS) has developed liquid submerged server (LSS) technology that changes the way computer electronics are cooled. The technology provides an option to cool electronics by the direct contact flow of dielectric fluid (coolant) into a sealed enclosure housing all the electronics of a single server. The intimate dielectric fluid contact with electronics improves the effectiveness of heat removal from the electronics.

The roles of garment design and scene complexity in the daytime conspicuity of high-visibility safety apparel.

PubMed

Sayer, James R; Buonarosa, Mary Lynn

2008-01-01

This study examines the effects of high-visibility garment design on daytime pedestrian conspicuity in work zones. Factors assessed were garment color, amount of background material, pedestrian arm motion, scene complexity, and driver age. The study was conducted in naturalistic conditions on public roads in real traffic. Drivers drove two passes on a 31-km route and indicated when they detected pedestrians outfitted in the fluorescent garments. The locations of the vehicle and the pedestrian were recorded. Detection distances between fluorescent yellow-green and fluorescent red-orange garments were not significantly different, nor were there any significant two-way interactions involving garment color. Pedestrians were detected at longer distances in lower complexity scenes. Arm motion significantly increased detection distances for pedestrians wearing a Class 2 vest, but had little added benefit on detection distances for pedestrians wearing a Class 2 jacket. Daytime detection distances for pedestrians wearing Class 2 or Class 3 garments are longest when the complexity of the surround is low. The more background information a driver has to search through, the longer it is likely to take the driver to locate a pedestrian--even when wearing a high-visibility garment. These findings will provide information to safety garment manufacturers about characteristics of high-visibility safety garments which make them effective for daytime use.

Use of compression garments by women with lymphoedema secondary to breast cancer treatment.

PubMed

Longhurst, E; Dylke, E S; Kilbreath, S L

2018-02-19

This aim of this study was to determine the use of compression garments by women with lymphoedema secondary to breast cancer treatment and factors which underpin use. An online survey was distributed to the Survey and Review group of the Breast Cancer Network Australia. The survey included questions related to the participants' demographics, breast cancer and lymphoedema medical history, prescription and use of compression garments and their beliefs about compression and lymphoedema. Data were analysed using principal component analysis and multivariable logistic regression. Compression garments had been prescribed to 83% of 201 women with lymphoedema within the last 5 years, although 37 women had discontinued their use. Even when accounting for severity of swelling, type of garment(s) and advice given for use varied across participants. Use of compression garments was driven by women's beliefs that they were vulnerable to progression of their disease and that compression would prevent its worsening. Common reasons given as to why women had discontinued their use included discomfort, and their lymphoedema was stable. Participant characteristics associated with discontinuance of compression garments included their belief that (i) the garments were not effective in managing their condition, (ii) experienced mild-moderate swelling and/or (iii) had experienced swelling for greater than 5 years. The prescription of compression garments for lymphoedema is highly varied and may be due to lack of underpinning evidence to inform treatment.

The influence of liquid-gas velocity ratio on the noise of the cooling tower

NASA Astrophysics Data System (ADS)

Yang, Bin; Liu, Xuanzuo; Chen, Chi; Zhao, Zhouli; Song, Jinchun

2018-05-01

The noise from the cooling tower has a great influence on psychological performance of human beings. The cooling tower noise mainly consists of fan noise, falling water noise and mechanical noise. This thesis used DES turbulence model with FH-W model to simulate the flow and sound pressure field in cooling tower based on CFD software FLUENT and analyzed the influence of different kinds noise, which affected by diverse factors, on the cooling tower noise. It can be concluded that the addition of cooling water can reduce the turbulence and vortex noise of the rotor fluid field in the cooling tower at some extent, but increase the impact noise of the liquid-gas two phase. In general, the cooling tower noise decreases with the velocity ratio of liquid to gas increasing, and reaches the lowest when the velocity ratio of liquid to gas is close to l.

Layering garments during rest and exercise in the cold (8°C): wearer responses and comparability with selected fabric properties.

PubMed

MacRae, Braid A; Laing, Raechel M; Wilson, Cheryl A; Niven, Brian E

2014-01-01

How garments contribute to performance of the clothing system during wear is of interest, as is understanding the value of using fabric properties to inform end-use characteristics. To investigate the influences of layering upper-body garments, four fabrics were used to construct two first-layer garments (wool and polyester) and two outer-layer garments (wool and membrane laminate). Over six sessions, 10 moderately trained males wore each first-layer garment as a single layer and in combination with each outer-layer garment while resting, running and walking in cold environmental conditions (8 ± 1°C, 81 ± 4% RH). Here, the type of garment arrangement worn (fabric type or number of layers) had little influence on heart rate, core body temperature and change in body mass. Weighted mean covered skin temperature was warmer and weighted mean next-to-skin vapour pressure was typically higher (following the onset of exercise) with two layers versus one. Differences among fabrics for individual properties were typically overstated compared to differences among corresponding garments for physiological and psychophysical variables under the conditions of this study. These findings inform the interpretation of particular fabric properties and highlight issues to be acknowledged during development/refinement of fabric test methods. We examined the way in which selected fibre, fabric and garment (layering) characteristics contribute to performance of the clothing system during wear under cold conditions. Selected properties of the constituent fabrics were found to provide limited insight into how garments perform during wear under the conditions of this study.

Liquid over-feeding air conditioning system and method

DOEpatents

Mei, Viung C.; Chen, Fang C.

1993-01-01

A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant.

77 FR 51514 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary Affirmative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-812] Steel Wire Garment Hangers... preliminary determination in the antidumping duty investigation of steel wire garment hangers from the... withdrawing its participation from this investigation.\\5\\ \\1\\ See Steel Wire Garment Hangers From the...

77 FR 66952 - Steel Wire Garment Hangers From the People's Republic of China: Antidumping Duty Administrative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-08

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... (``the Department'') is conducting the third administrative review of steel wire garment hangers from the... Wire Garment Hangers From the People's Republic of China: Preliminary Results and Preliminary...

77 FR 73424 - Steel Wire Garment Hangers From Taiwan: Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-583-849] Steel Wire Garment Hangers... ``ITC''), the Department is issuing an antidumping duty order on steel wire garment hangers from Taiwan... antidumping duty investigation of steel wire garment hangers from Taiwan.\\1\\ On November 29, 2012, the ITC...

77 FR 72884 - Steel Wire Garment Hangers From Taiwan

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-06

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-1197 (Final)] Steel Wire Garment Hangers... injured by reason of imports of steel wire garment hangers from Taiwan, provided for in subheading 7326.20... notification of a preliminary determination by Commerce that imports of steel wire garment hangers from Taiwan...

75 FR 42685 - Steel Wire Garment Hangers From the People's Republic of China: Initiation of Anti-Circumvention...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-22

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers...-circumvention inquiry to determine whether certain imports of steel wire garment hangers from the Socialist Republic of Vietnam (``Vietnam'') are circumventing the antidumping duty order on steel wire garment...

77 FR 75973 - Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Final Affirmative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

... DEPARTMENT OF COMMERCE International Trade Administration [C-552-813] Certain Steel Wire Garment...) determines that countervailable subsidies are being provided to producers and exporters of steel wire garment... Companies). \\1\\ See Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Initiation of...

77 FR 28354 - Steel Wire Garment Hangers From the People's Republic of China: Extension of Time Limit for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-14

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... International Trade Compliance Analyst, Office 9, regarding Third Administrative Review of Steel Wire Garment..., Import Administration; regarding the Antidumping Duty Administrative Review of Steel Garment Wire Hangers...

High visibility safety apparel and nighttime conspicuity of pedestrians in work zones.

PubMed

Sayer, James R; Mefford, Mary Lynn

2004-01-01

Every year numerous occupational fatalities result from pedestrians being struck by motor vehicles intruding into work zones. Attributes of retroreflective personal safety garments on pedestrian conspicuity at night were assessed in a field study. Using instrumented vehicles on a closed track, participants drove through simulated work zones attempting to detect pedestrians located in the work zones. Configuration of the retroreflective trim, trim color, placement in the work zone, and driver age significantly affected pedestrian conspicuity. Intensity and the amount of retroreflective trim did not. Personal safety garments incorporating retroreflective trim significantly improve pedestrian conspicuity in work zones. The results emphasize the importance of retroreflective trim on personal safety garments, particularly if the trim is located on garment sleeves. We examine the design attributes that contribute to making a personal safety garment conspicuous. The results have implications regarding preferred garment designs, industry standards, and service life of personal safety garments.

16 CFR 1616.31 - Labeling, recordkeeping, retail display and guaranties.

Code of Federal Regulations, 2010 CFR

2010-01-01

... process of manufacture of each production unit of articles of children's sleepwear, or fabrics or related... production unit or by style. A style is a garment design or grouping, preselected by the manufacturer. A... garment design or on the garment packages. A style is a garment design or grouping, preselected by the...

75 FR 68758 - Steel Wire Garment Hangers From the People's Republic of China: Preliminary Results and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-09

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... first administrative review of the antidumping duty order on steel wire garment hangers from the People... steel wire garment hangers (``hangers'') from the PRC. See Notice of Antidumping Duty Order: Steel Wire...

77 FR 40853 - Steel Wire Garment Hangers From the People's Republic of China: Partial Rescission of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-11

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... administrative review of the antidumping duty order on steel wire garment hangers from the People's Republic of... the Secretary of Commerce ``Third Administrative Review of Steel Wire Garment Hangers from China...

77 FR 14002 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Notice of Postponement of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... DEPARTMENT OF COMMERCE International Trade Administration [C-552-813] Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Notice of Postponement of Preliminary Determination in the... investigation of steel wire garment hangers from the Socialist Republic of Vietnam. See Steel Wire Garment...

77 FR 73430 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary Affirmative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... DEPARTMENT OF COMMERCE International Trade Administration [C-552-813] Steel Wire Garment Hangers... respect to imports of steel wire garment hangers from the Socialist Republic of Vietnam (Vietnam) with the... Department of Commerce building. \\3\\ See Steel Wire Garment Hangers From the Socialist Republic of Vietnam...

77 FR 3737 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Initiation of Countervailing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-25

... DEPARTMENT OF COMMERCE International Trade Administration [C-552-813] Steel Wire Garment Hangers... countervailing duty (CVD) petition concerning imports of steel wire garment hangers from the Socialist Republic...). See Petition for the Imposition of Antidumping Duties on Steel Wire Garment Hangers from Taiwan and...

78 FR 8107 - Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Countervailing Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-05

... DEPARTMENT OF COMMERCE International Trade Administration [C-552-813] Certain Steel Wire Garment... Department is issuing a countervailing duty order on certain steel wire garment hangers from the Socialist... its final determination in the countervailing duty investigation of certain steel wire garment hangers...

76 FR 28953 - Steel Wire Garment Hangers From the People's Republic of China: Extension of Time Limits for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-19

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... administrative review of the antidumping duty order on steel wire garment hangers from the People's Republic of... Trade Compliance Analyst, Office 9, regarding the Second Administrative Review of Steel Wire Garment...

77 FR 9701 - Steel Wire Garment Hangers From Taiwan And Vietnam

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

...)] Steel Wire Garment Hangers From Taiwan And Vietnam Determinations On the basis of the record \\1... injured by reason of imports from Taiwan and Vietnam of steel wire garment hangers, provided for in... the United States at less than fair value (LTFV) and steel wire garment hangers from Vietnam that are...

78 FR 70271 - Steel Wire Garment Hangers From the People's Republic of China: Preliminary Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-25

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... the antidumping duty order on steel wire garment hangers from the People's Republic of China (``PRC... comment on these preliminary results. \\1\\ See Notice of Antidumping Duty Order: Steel Wire Garment Hangers...

Alternative Compression Garments

NASA Technical Reports Server (NTRS)

Stenger, M. B.; Lee, S. M. C.; Ribeiro, L. C.; Brown, A. K.; Westby, C. M.; Platts, S. H.

2011-01-01

Orthostatic intolerance after spaceflight is still an issue for astronauts as no in-flight countermeasure has been 100% effective. Future anti-gravity suits (AGS) may be similar to the Shuttle era inflatable AGS or may be a mechanical compression device like the Russian Kentavr. We have evaluated the above garments as well as elastic, gradient compression garments of varying magnitude and determined that breast-high elastic compression garments may be a suitable replacement to the current AGS. This new garment should be more comfortable than the AGS, easy to don and doff, and as effective a countermeasure to orthostatic intolerance. Furthermore, these new compression garments could be worn for several days after space flight as necessary if symptoms persisted. We conducted two studies to evaluate elastic, gradient compression garments. The purpose of these studies was to evaluate the comfort and efficacy of an alternative compression garment (ACG) immediately after actual space flight and 6 degree head-down tilt bed rest as a model of space flight, and to determine if they would impact recovery if worn for up to three days after bed rest.

A comparison of the effects of a special gynaecological garment and music in reducing the anxiety related to gynaecological examination.

PubMed

Kocabaş, Pembegül; Khorshid, Leyla

2012-03-01

To investigate the effect of a special gynaecological garment and music plus the special gynaecological garment on reducing the state anxiety related to gynaecological examination. Gynaecological examination is one of the most common anxiety-producing medical procedures and causes embarrassment and discomfort. Few studies have focused on the effect of a gynaecological garment on anxiety associated with gynaecological examinations. The patients were allocated to one of three groups, one control and two experimental. While the patients in the control group were subjected to the normal outpatient procedure, the patients in the first experimental group were dressed in a special gynaecological garment. In the control group, gynaecological examinations were performed with a traditional one-piece drape. In addition to wearing the special gynaecological garment, the women in the garment + music group listened to music during the gynaecological examination. The State Anxiety Inventory Form was applied to the patients in all three groups before and after gynaecological examination. The state anxiety level after gynaecological examination in patients in the control group was found to be higher, but it was found to be lower in patients in both the first experimental group (garment) and the second experimental group (garment + music). The state anxiety level was found to be more reduced in the experimental groups than in the control group. The state anxiety level after gynaecological examination was found to be higher in single patients in the second experimental group. The special gynaecological garments are effective in reducing the state anxiety associated with gynaecological examination. It should be taken into consideration that women perceived state anxiety during the gynaecological examinations. To allay anxiety associated with gynaecological examination in women, a special garment may be considered. © 2011 Blackwell Publishing Ltd.

Synthetic garments enhance comfort, thermoregulatory response, and athletic performance compared with traditional cotton garments.

PubMed

Hooper, David R; Cook, Brendan M; Comstock, Brett A; Szivak, Tunde K; Flanagan, Shawn D; Looney, David P; DuPont, William H; Kraemer, William J

2015-03-01

The ability of a fabric to transfer moisture is referred to as "wicking," and an increase in this property may have benefits in terms of comfort and thermoregulation. However, this phenomenon has not been studied in the context of sporting-type activities. Therefore, the purpose of this study is to assess whether comfort, thermal physiological parameters, and physical performance can be affected by the garment that is used. Ten men (age: 27.5 ± 4.4 years; height: 169.3 ± 14.2 cm; weight: 80.05 ± 10.87 kg) and 10 women (age: 26.8 ± 3.7 years; height: 166.6 ± 4.46 cm; weight: 64.63 ± 4.49 kg) volunteered to participate in the study. A within-group crossover counterbalanced design was used that included the Illinois Agility Run (IAR) and the Multistage Fitness Test (MSFT). The IAR was also performed while wearing protective padding. The protocol was completed on 2 occasions, once while wearing a cotton garment (C) and again while wearing a polyester (P) garment. Questionnaires referring to sensations of various components of comfort were completed after each test. The P garment provided significantly (p ≤ 0.05) greater comfort in men and women after both the IAR and the MSFT. The P garment led to significantly (p ≤ 0.05) improved performance during the IAR in women. The P garment also provided significantly (p ≤ 0.05) greater body mass loss during the protocol in women. This study demonstrated dramatic increases in the comfort of P garments, including while using protective equipment. This study also discovered the influence of P garments on anaerobic tasks and also revealed dramatic sex differences, where women seem to be much more sensitive to the benefits of P garments. Strength and conditioning coaches should be aware of the dramatic impact of garment choice, in aerobic and anaerobic tasks, particularly in women.

Development of Gradient Compression Garments for Protection Against Post Flight Orthostatic Intolerance

NASA Technical Reports Server (NTRS)

Stenger, M. B.; Lee, S. M. C.; Westby, C. M.; Platts, S. H.

2010-01-01

Orthostatic intolerance after space flight is still an issue for astronaut health. No in-flight countermeasure has been 100% effective to date. NASA currently uses an inflatable anti-gravity suit (AGS) during reentry, but this device is uncomfortable and loses effectiveness upon egress from the Shuttle. The Russian Space Agency currently uses a mechanical counter-pressure garment (Kentavr) that is difficult to adjust alone, and prolonged use may result in painful swelling at points where the garment is not continuous (feet, knees, and groin). To improve comfort, reduce upmass and stowage requirements, and control fabrication and maintenance costs, we have been evaluating a variety of gradient compression, mechanical counter-pressure garments, constructed from spandex and nylon, as a possible replacement for the current AGS. We have examined comfort and cardiovascular responses to knee-high garments in normovolemic subjects; thigh-high garments in hypovolemic subjects and in astronauts after space flight; and 1-piece, breast-high garments in hypovolemic subjects. These gradient compression garments provide 55 mmHg of compression over the ankle, decreasing linearly to 35 mmHg at the knee. In thigh-high versions the compression continues to decrease to 20 mmHg at the top of the leg, and for breast-high versions, to 15 mmHg over the abdomen. Measures of efficacy include increased tilt survival time, elevated blood pressure and stroke volume, and lower heart-rate response to orthostatic stress. Results from these studies indicate that the greater the magnitude of compression and the greater the area of coverage, the more effective the compression garment becomes. Therefore, we are currently testing a 3-piece breast-high compression garment on astronauts after short-duration flight. We chose a 3-piece garment consisting of thigh-high stockings and shorts, because it is easy to don and comfortable to wear, and should provide the same level of protection as the 1-piece breast-high garments evaluated in hypovolemic test subjects.

Cooling vests with phase change materials: the effects of melting temperature on heat strain alleviation in an extremely hot environment.

PubMed

Gao, Chuansi; Kuklane, Kalev; Holmér, Ingvar

2011-06-01

A previous study by the authors using a heated thermal manikin showed that the cooling rates of phase change material (PCM) are dependent on temperature gradient, mass, and covering area. The objective of this study was to investigate if the cooling effects of the temperature gradient observed on a thermal manikin could be validated on human subjects in extreme heat. The subjects wore cooling vests with PCMs at two melting temperatures (24 and 28°C) and fire-fighting clothing and equipment, thus forming three test groups (vest24, vest28 and control group without the vest). They walked on a treadmill at a speed of 5 km/h in a climatic chamber (air temperature = 55°C, relative humidity = 30%, vapour pressure = 4,725 Pa, and air velocity = 0.4 m/s). The results showed that the PCM vest with a lower melting temperature (24°C) has a stronger cooling effect on the torso and mean skin temperatures than that with a higher melting temperature (28°C). Both PCM vests mitigate peak core temperature increase during the resting recovery period. The two PCM vests tested, however, had no significant effect on the alleviation of core temperature increase during exercise in the heat. To study the possibility of effective cooling of core temperature, cooling garments with PCMs at even lower melting temperatures (e.g. 15°C) and a larger covering area should be investigated.

Assessment of external heat transfer coefficient during oocyte vitrification in liquid and slush nitrogen using numerical simulations to determine cooling rates.

PubMed

Santos, M V; Sansinena, M; Zaritzky, N; Chirife, J

2012-01-01

In oocyte vitrification, plunging directly into liquid nitrogen favor film boiling and strong nitrogen vaporization. A survey of literature values of heat transfer coefficients (h) for film boiling of small metal objects with different geometries plunged in liquid nitrogen revealed values between 125 to 1000 W per per square m per K. These h values were used in a numerical simulation of cooling rates of two oocyte vitrification devices (open-pulled straw and Cryotop), plunged in liquid and slush nitrogen conditions. Heat conduction equation with convective boundary condition was considered a linear mathematical problem and was solved using the finite element method applying the variational formulation. COMSOL Multiphysics was used to simulate the cooling process of the systems. Predicted cooling rates for OPS and Cryotop when cooled at -196 degree C (liquid nitrogen) or -207 degree C (average for slush nitrogen) for heat transfer coefficients estimated to be representative of film boiling, indicated lowering the cooling temperature produces only a maximum 10 percent increase in cooling rates; confirming the main benefit of plunging in slush over liquid nitrogen does not arise from their temperature difference. Numerical simulations also demonstrated that a hypothetical four-fold increase in the cooling rate of vitrification devices when plunging in slush nitrogen would be explained by an increase in heat transfer coefficient. This improvement in heat transfer (i.e., high cooling rates) in slush nitrogen is attributed to less or null film boiling when a sample is placed in slush (mixture of liquid and solid nitrogen) because it first melts the solid nitrogen before causing the liquid to boil and form a film.

Impact of using scatter-mimicking beams instead of standard beams to measure penetration when assessing the protective value of radiation-protective garments.

PubMed

Jones, A Kyle; Pasciak, Alexander S; Wagner, Louis K

2018-03-01

Use standardized methods to determine how assessment of protective value of radiation-protective garments changes under conditions employing standard beam qualities, scatter-mimicking primary beams, and a modified H p (10) measurement. The shielding properties of radiation-protective garments depend on the spectrum of beam energies striking the garment and the attenuation properties of materials used to construct the garment, including x-ray fluorescence produced by these materials. In this study the primary beam spectra employed during clinical interventional radiology and cardiology procedures (clinical primary beams, CPB) were identified using radiation dose structured reports (RDSR) and fluoroscope log data. Monte Carlo simulation was used to determine the scattered radiation spectra produced by these CPB during typical clinical application. For these scattered spectra, scatter-mimicking primary beams (SMPB) were determined using numerical optimization-based spectral reconstruction that adjusted kV and filtration to produce the SMPB that optimally matched the scattered spectrum for each CPB. The penetration of a subset of SMPB through four radiation-protective garments of varying compositions and nominal thicknesses was measured using a geometry specified by the International Electrotechnical Commission (IEC). The diagnostic radiological index of protection (DRIP), which increases with increasing penetration through a garment, was calculated using these measurements. Penetration through the same garments was measured for standard beams specified by the American Society of Testing and Materials (ASTM). Finally, 10 mm of PMMA was affixed to the inside of each garment and the DRIP remeasured in this configuration to simulate H p (10). The SMPB based on actual CPB were in general characterized by lower kV (range 60-76) and higher half-value layer (HVL, range 3.44-4.89 mm Al) than standard beam qualities specified by ASTM (kV range 70-85; HVL range 3.4-4.0 mm Al). A lead garment of nominal thickness 0.5 mm (D) had a DRIP of 0.8%, two lead-free garments of 0.5 mm nominal thickness had DRIPs of 1.2% (A) and 2.2% (B), and a lead-free bilayer (C) had a DRIP of 1.4%. When standard beam qualities specified by the ASTM were used, the DRIP for D was 2.2%, 175% higher than the DRIP measured using SMPB, and for A, B, and C was 2.8%, 3.2%, and 2.9%, respectively. This was 133%, 45%, and 107% higher than the DRIP measured using SMPB. Differences between the DRIP of lead-alternative garments and the lead garment were reduced when measured with 10 mm of PMMA. Using this method, the measured DRIPs were 2.2% (A), 3.1% (B), 2.5% (C), and 2.3% (D). Penetration of radiation through radiation-protective garments depended strongly on the methods and X-ray spectra used for evaluation. The DRIP was higher (i.e., protective value was lower) for lead-alternative garments than for lead garments in this evaluation. The DRIP was lower for all garments when SMPB based on actual clinical beam quality data were used to measure penetration compared to ASTM standard beams. Differences in penetration between lead-alternative and lead garments were less when the DRIP was measured with 10 mm of PMMA between the garment and the chamber. © 2018 American Association of Physicists in Medicine.

Liquid over-feeding air conditioning system and method

DOEpatents

Mei, V.C.; Chen, F.C.

1993-09-21

A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant. 1 figure.

Spinoff from a Moonsuit

NASA Technical Reports Server (NTRS)

1989-01-01

Hypohidrotic ectodermal dysplasia refers to the absence of sweat glands which allow body heat to escape. Children with the disease become overheated quickly and suffer from a number of related afflictions. Several have been assisted by Life Support Systems, Inc., a NASA spinoff company which manufactures a garment cooled by a heat exchanger powered by a minipump through a network of fluid-filled tubes. The suits are used by firefighters, crop dusting pilots, workers in hazardous industries, etc. The company was founded by a former NASA contractor employee. When Sara Moody, whose nephew Stevie Roper has HED, contacted Langley Research Center, she was referred to LSSI. With help from PoFolks Restaurant Corporation and others, she raised $5,000 for a suit for Stevie. LSSI agreed to manufacture the suit at cost. After receiving the suit, Stevie's life improved dramatically, and Sara Moody established the HED Foundation. Through the foundation, other children have also received cool suits.

78 FR 8105 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Antidumping Duty Order

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-05

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-812] Steel Wire Garment Hangers...''), the Department is issuing an antidumping duty order on steel wire garment hangers from the Socialist... investigation of steel wire garment hangers from Vietnam.\\1\\ On January 28, 2013, pursuant to section 735(d) of...

77 FR 75980 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Final Determination of Sales...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-812] Steel Wire Garment Hangers... less than fair value (``LTFV'') in the antidumping investigation of steel wire garment hangers from the... Determination of sales at LTFV. We continue to determine that steel wire garment hangers from Vietnam are being...

78 FR 28803 - Steel Wire Garment Hangers From the People's Republic of China: Final Results of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-16

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... review of the antidumping duty order on steel wire garment hangers from the People's Republic of China..., 2010, through September 30, 2011. \\1\\ See Steel Wire Garment Hangers from the People's Republic of...

77 FR 70993 - Steel Wire Garment Hangers From the People's Republic of China: 2011-2012 Initiation of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-28

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... for a new shipper review (``NSR'') of the antidumping duty order on steel wire garment hangers from... antidumping duty order on steel wire garment hangers from the PRC (``the Order'') was published on October 6...

77 FR 50713 - Steel Wire Garment Hangers From Taiwan and Vietnam; (Corrected Notice) Scheduling of the Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

...)] Steel Wire Garment Hangers From Taiwan and Vietnam; (Corrected Notice) Scheduling of the Final Phase of... the United States is materially retarded, by reason of subsidized imports from Vietnam of steel wire garment hangers and less- than-fair-value imports from Taiwan and Vietnam of steel wire garment hangers...

77 FR 50160 - Steel Wire Garment Hangers From Taiwan and Vietnam; Scheduling of the Final Phase of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-20

...)] Steel Wire Garment Hangers From Taiwan and Vietnam; Scheduling of the Final Phase of Countervailing Duty... States is materially retarded, by reason of subsidized imports from Taiwan of steel wire garment hangers and less- than-fair-value imports from Taiwan and Vietnam of steel wire garment hangers, provided for...

77 FR 19191 - Steel Wire Garment Hangers From the People's Republic of China: Amended Final Results of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... results of the second administrative review of the antidumping duty order on steel wire garment hangers... not change the current rates of any other parties. \\1\\ See Steel Wire Garment Hangers From the People...

77 FR 12553 - Steel Wire Garment Hangers From the People's Republic of China: Final Results and Final Partial...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-01

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... duty order \\1\\ on steel wire garment hangers from the People's Republic of China (``PRC'').\\2\\ We gave... Duty Order: Steel Wire Garment Hangers From the People's Republic of China, 73 FR 58111 (October 6...

Study on the integration approaches to CAD/CAPP/FMS in garment CIMS

NASA Astrophysics Data System (ADS)

Wang, Xiankui; Tian, Wensheng; Liu, Chengying; Li, Zhizhong

1995-08-01

Computer integrated manufacturing system (CIMS), as an advanced methodology, has been applied in many industry fields. There is, however, little research on the application of CIMS in the garment industry, especially on the integrated approach to CAD, CAPP, and FMS in garment CIMS. In this paper, the current situations of CAD, CAPP, and FMS in the garment industry are discussed, and information requirements between them as well as the integrated approaches are also investigated. The representation of the garments' product data by the group technology coding is proposed. Based on the group technology, a shared data base as an integration element can be constructed, which leads to the integration of CAD/CAPP/FMS in garment CIMS.

Determining localized garment insulation values from manikin studies: computational method and results.

PubMed

Nelson, D A; Curlee, J S; Curran, A R; Ziriax, J M; Mason, P A

2005-12-01

The localized thermal insulation value expresses a garment's thermal resistance over the region which is covered by the garment, rather than over the entire surface of a subject or manikin. The determination of localized garment insulation values is critical to the development of high-resolution models of sensible heat exchange. A method is presented for determining and validating localized garment insulation values, based on whole-body insulation values (clo units) and using computer-aided design and thermal analysis software. Localized insulation values are presented for a catalog consisting of 106 garments and verified using computer-generated models. The values presented are suitable for use on volume element-based or surface element-based models of heat transfer involving clothed subjects.

Liquid cooled approaches for high density avionics

NASA Astrophysics Data System (ADS)

Levasseur, Robert

Next-generation aircraft will require avionics that provide greater system performance in a smaller volume, a process that requires highly developed thermal management techniques. To meet this need, a liquid-cooled approach has been developed to replace the conventional air-cooled approach for high-power applications. Liquid-cooled chassis and flow-through modules have been developed to limit junction temperatures to acceptable levels. Liquid cooling also permits emergency operation after loss of coolant for longer time intervals, which is desirable for flight-critical airborne applications. Activity to date has emphasized the development of chassis and modules that support the US Department of Defense's (DoD) two-level maintenance initiative as governed by the Joint Integrated Avionics Working Group (JIAWG).

Physiological and Psychological Responses during Exercise and Recovery in a Cold Environment Is Gender-Related Rather Than Fabric-Related

PubMed Central

Cernych, Margarita; Baranauskiene, Neringa; Eimantas, Nerijus; Kamandulis, Sigitas; Daniuseviciute, Laura; Brazaitis, Marius

2017-01-01

We evaluated gender-specific effects of two types of undergarments on exercise-induced physiological and psychological stress and subsequent recovery in cold conditions for male and female participants. Ten healthy men and eleven healthy women (25.0 ± 1.5 versus 23.4 ± 1.2 years old, respectively) completed the experimental session twice with two different types of undergarments: polyester or merino wool leggings and long-sleeve tops; specifically, merino fabric had greater thermal resistance and water absorbency, and less water vapor as well as air permeability than polyester. Experimental sessions involved performing 1 h of exercise on a cycle ergometer at 8°C ambient temperature and 55% relative humidity, holding at 70–80 revolutions per minute and 60% of each participant’s predetermined maximal power output (assessed by maximal oxygen uptake test), followed by 1 h recovery in the same environment. Every 5 min during exercise and every 10 min during recovery, rectal temperature, heart rate, subjective ratings for thermal, shivering/sweating and clothing wetness sensations, and clothing next-to-skin and outer side surface temperature and humidity on the chest, back and thigh were recorded. All participants experienced high physiological stress (assessed by physiological strain index) during exercise. No significant gender differences were found in core temperature or heart rate changes during exercise, but women cooled down faster during recovery. Next-to-skin humidity was similar between genders and different garment sets during exercise and recovery, but such temperatures at the chest during exercise and at the thigh during exercise and recovery were lower in women with both sets of garments. Subjective thermal sensations were similar in all cases. In the last 20 min of cycling, women started to feel wetter than men (P < 0.05) for both garment sets. Shivering was reported as stronger in women in the last 10 min of recovery. Most of the changes in the garment microclimates during exercise and recovery in the cold were associated with gender-related differences rather than with fabric-related differences. PMID:28824518

NREL Evaluates Aquarius Liquid-Cooled High-Performance Computing Technology

Science.gov Websites

HPC and influence the modern data center designer towards adoption of liquid cooling. Our shared technology. Aquila and Sandia chose NREL's HPC Data Center for the initial installation and evaluation because the data center is configured for liquid cooling, along with the required instrumentation to

Asetek's Warm-Water Liquid Cooling System Yields Energy Cost Savings at

Science.gov Websites

NREL | Energy Systems Integration Facility | NREL Asetek Asetek's Warm-Water Liquid Cooling System Yields Energy Cost Savings at NREL Asetek's RackCDU liquid cooling system was installed and tested at the Energy Systems Integration Facility's (ESIF's) ultra-energy-efficient high-performance

Morphing Compression Garments for Space Medicine and Extravehicular Activity Using Active Materials.

PubMed

Holschuh, Bradley T; Newman, Dava J

2016-02-01

Compression garments tend to be difficult to don/doff, due to their intentional function of squeezing the wearer. This is especially true for compression garments used for space medicine and for extravehicular activity (EVA). We present an innovative solution to this problem by integrating shape changing materials-NiTi shape memory alloy (SMA) coil actuators formed into modular, 3D-printed cartridges-into compression garments to produce garments capable of constricting on command. A parameterized, 2-spring analytic counterpressure model based on 12 garment and material inputs was developed to inform garment design. A methodology was developed for producing novel SMA cartridge systems to enable active compression garment construction. Five active compression sleeve prototypes were manufactured and tested: each sleeve was placed on a rigid cylindrical object and counterpressure was measured as a function of spatial location and time before, during, and after the application of a step voltage input. Controllable active counterpressures were measured up to 34.3 kPa, exceeding the requirement for EVA life support (29.6 kPa). Prototypes which incorporated fabrics with linear properties closely matched analytic model predictions (4.1%/-10.5% error in passive/active pressure predictions); prototypes using nonlinear fabrics did not match model predictions (errors >100%). Pressure non-uniformities were observed due to friction and the rigid SMA cartridge structure. To our knowledge this is the first demonstration of controllable compression technology incorporating active materials, a novel contribution to the field of compression garment design. This technology could lead to easy-to-don compression garments with widespread space and terrestrial applications.

Immune functions of the garment workers.

PubMed

Sultana, R; Ferdous, K J; Hossain, M; Zahid, M S H; Islam, L N

2012-10-01

Occupational exposure to cotton dust, fibers, metal fumes and different chemicals used in the aparrel manufacturing industries cause a wide range of physical and psychological health problems in the garment workers that may also affect their immune function. To assess the immune system function in garment workers. A total of 45 workers of a garment factory, and 41 control subjects, not exposed to the garment working environment were enrolled in this study. In the study subjects, the complement system function was assessed as bactericidal activity on Escherichia coli DH5α cells using the standard plate count method. Serum complement components C3 and C4 were measured by immunoprecipitation, and IgG was measured by immunonephelometry. The bactericidal activity of serum complement in the garment workers (range: 93.5%-99.9%) was significantly (p<0.01) lower than that in the controls (range: 98.6%-100%). The heat-inactivated serum of the workers showed a significantly enhanced bactericidal activity. In the garment workers, the mean levels of complement C3, and C4 were 1.75 and 0.26 g/L, respectively that were close to those of the controls. The mean IgG level in the garment workers was 13.5 g/L that was significantly (p<0.001) higher than that in the controls. Working in a garment factory may affect the immune system.

Individual thermal profiles as a basis for comfort improvement in space and other environments

NASA Technical Reports Server (NTRS)

Koscheyev, V. S.; Coca, A.; Leon, G. R.; Dancisak, M. J.

2002-01-01

BACKGROUND: The development of individualized countermeasures to address problems in thermoregulation is of considerable importance for humans in space and other extreme environments. A methodology is presented for evaluating minimal/maximal heat flux from the total human body and specific body zones, and for assessing individual differences in the efficiency of heat exchange from these body areas. The goal is to apply this information to the design of individualized protective equipment. METHODS: A multi-compartment conductive plastic tubing liquid cooling/warming garment (LCWG) was developed. Inlet water temperatures of 8-45 degrees C were imposed sequentially to specific body areas while the remainder of the garment was maintained at 33 degrees C. RESULTS: There were significant differences in heat exchange level among body zones in both the 8 degrees and 45 degrees C temperature conditions (p < 0.001). The greatest amount of heat was absorbed/released by the following areas: thighs (8 degrees C: -2.12 +/- 0.14 kcal min(-1); 45 degrees C: +1.58 +/- 0.23); torso (8 degrees C: -2.12 +/- 0.13 kcal min(-1); 45 degrees C: +1.31 +/- 0.27); calves (8 degrees C: -1.59 +/- 0.26 kcal min(-1); 45 degrees C: +1.53 +/- 0.24); and forearms (8 degrees C: -1.67 +/- 0.29 kcal x min(-1); 45 degrees C: +1.45 +/- 0.20). These are primarily zones with relatively large muscle mass and adipose tissue. Calculation of absorption/release heat rates standardized per unit tube length and flow rate instead of zonal surface area covered showed that there was significantly greater heat transfer in the head, hands, and feet (p < 0.001). The areas in which there was considerable between-subject variability in rates of heat transfer and thus most informative for individual profile design were the torso, thighs, shoulders, and calves or forearms. CONCLUSIONS: The methodology developed is sensitive to individual differences in the process of heat exchange and variations in different body areas, depending on their size and tissue mass content. The design of individual thermal profiles is feasible for better comfort of astronauts on long-duration missions and personnel in other extreme environments.

76 FR 27994 - First Administrative Review of Steel Wire Garment Hangers From the People's Republic of China...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-13

... of Steel Wire Garment Hangers From the People's Republic of China: Final Results and Final Partial... antidumping duty order on steel wire garment hangers from the People's Republic of China (``PRC'').\\1\\ We gave... period of review (``POR''), March 25, 2008, through November 30, 2009. \\1\\ See Steel Wire Garment Hangers...

National Workplace Literacy Program. Garment-Related Bilingual (English & Chinese) T.V. Broadcast Lessons. Book II: Episodes 16-27.

ERIC Educational Resources Information Center

Chinatown Manpower Project, Inc., New York, NY.

This publication contains a series of 12 garment-related bilingual (English and Chinese) television broadcast lessons that were produced to augment an earlier series of 15 lessons. The objective of these television lessons is to teach garment-related English terminology to the garment workers who cannot attend classes in the National Workplace…

Cooling for a rotating anode X-ray tube

DOEpatents

Smither, Robert K.

1998-01-01

A method and apparatus for cooling a rotating anode X-ray tube. An electromagnetic motor is provided to rotate an X-ray anode with cooling passages in the anode. These cooling passages are coupled to a cooling structure located adjacent the electromagnetic motor. A liquid metal fills the passages of the cooling structure and electrical power is provided to the motor to rotate the anode and generate a rotating magnetic field which moves the liquid metal through the cooling passages and cooling structure.

Use of a Garment as an Alternative to Body Painting in Equine Musculoskeletal Anatomy Teaching.

PubMed

Sattin, Mariana M; Silva, Vickitoriana K A; Leandro, Rafael M; Foz Filho, Roberto P P; De Silvio, Mauricio M

Living anatomy is gaining increasing popularity as an alternative to the use of preserved cadaver specimens in musculoskeletal anatomy teaching. This article describes the development of a garment painted with musculoskeletal structures as an alternative to body painting. Garments offer some advantages over traditional body painting in anatomy teaching. The technique can be used across different disciplines, enhances students' ability to identify anatomic structures in living bodies, and provides insights into the topography of one or more body systems at the same time. The fact that garments are amenable to palpation by large groups of students with no damage to the painting favors repeated use in hands-on wet labs. Garments such as the one described in this article introduce a novel approach to interdisciplinary teaching and learning, which can be combined with traditional anatomy teaching methods. The first garment produced depicts part of the equine musculoskeletal system. Steps in garment construction are highlighted and indications, advantages, and limitations of the method discussed.

Passive cooling system for liquid metal cooled nuclear reactors with backup coolant flow path

DOEpatents

Hunsbedt, Anstein; Boardman, Charles E.

1993-01-01

A liquid metal cooled nuclear fission reactor plant having a passive auxiliary safety cooling system for removing residual heat resulting from fuel decay during reactor shutdown, or heat produced during a mishap. This reactor plant is enhanced by a backup or secondary passive safety cooling system which augments the primary passive auxiliary cooling system when in operation, and replaces the primary system when rendered inoperable.

Passive cooling system for top entry liquid metal cooled nuclear reactors

DOEpatents

Boardman, Charles E.; Hunsbedt, Anstein; Hui, Marvin M.

1992-01-01

A liquid metal cooled nuclear fission reactor plant having a top entry loop joined satellite assembly with a passive auxiliary safety cooling system for removing residual heat resulting from fuel decay during shutdown, or heat produced during a mishap. This satellite type reactor plant is enhanced by a backup or secondary passive safety cooling system which augments the primary passive auxiliary cooling system when in operation, and replaces the primary cooling system when rendered inoperative.

Liquid-cooling technology for gas turbines review and status

NASA Technical Reports Server (NTRS)

Vanfossen, G. J., Jr.; Stepka, F. S.

1978-01-01

A review of research related to liquid cooling of gas turbines was conducted and an assessment of the state of the art was made. Various methods of liquid cooling turbines were reviewed. Examples and results with test and demonstrator turbines utilizing these methods along with the advantages and disadvantages of the various methods are discussed.

Lamp for generating high power ultraviolet radiation

DOEpatents

Morgan, Gary L.; Potter, James M.

2001-01-01

The apparatus is a gas filled ultraviolet generating lamp for use as a liquid purifier. The lamp is powred by high voltage AC, but has no metallic electrodes within or in contact with the gas enclosure which is constructed as two concentric quartz cylinders sealed together at their ends with the gas fill between the cylinders. Cooling liquid is pumped through the volume inside the inner quartz cylinder where an electrically conductive pipe spaced from the inner cylinder is used to supply the cooling liquid and act as the high voltage electrode. The gas enclosure is enclosed within but spaced from a metal housing which is connected to operate as the ground electrode of the circuit and through which the treated fluid flows. Thus, the electrical circuit is from the central pipe, and through the cooling liquid, the gas enclosure, the treated liquid on the outside of the outer quartz cylinder, and to the housing. The high voltage electrode is electrically isolated from the source of cooling liquid by a length of insulated hose which also supplies the cooling liquid.

Specific cooling capacity of liquid nitrogen

NASA Technical Reports Server (NTRS)

Kilgore, R. A.; Adcock, J. B.

1977-01-01

The assumed cooling process and the method used to calculate the specific cooling capacity of liquid nitrogen are described, and the simple equation fitted to the calculated specific cooling capacity data, together with the graphical form calculated values of the specific cooling capacity of nitrogen for stagnation temperatures from saturation to 350 K and stagnation pressures from 1 to 10 atmospheres, are given.

Method for passive cooling liquid metal cooled nuclear reactors, and system thereof

DOEpatents

Hunsbedt, Anstein; Busboom, Herbert J.

1991-01-01

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of partitions surrounding the reactor vessel in spaced apart relation forming intermediate areas for circulating heat transferring fluid which remove and carry away heat from the reactor vessel.

Liquid cooling applications on automotive exterior LED lighting

NASA Astrophysics Data System (ADS)

Aktaş, Mehmet; Şenyüz, Tunç; Şenyıldız, Teoman; Kılıç, Muhsin

2018-02-01

In this study cooling of a LED unit with heatsink and liquid cooling block which is used in automotive head lamp applications has been investigated numerically and experimentally. Junction temperature of a LED which is cooled with heatsink and liquid cooling block obtained in the experiment. 23°C is used both in the simulation and the experiment phase. Liquid cooling block material is choosed aluminium (Al) and polyamide. All tests and simulation are performed with three different flow rate. Temperature distribution of the designed product is investigated by doing the numerical simulations with a commercially software. In the simulations, fluid flow is assumed to be steady, incompressible and laminar and 3 dimensional (3D) Navier-Stokes equations are used. According to the calculations it is obtained that junction temperature is higher in the heatsink design compared to block cooled one. By changing the block material, it is desired to investigate the variation on the LED junction temperature. It is found that more efficient cooling can be obtained in block cooling by using less volume and weight. With block cooling lifetime of LED can be increased and flux loss can be decreased with the result of decreased junction temperature.

Pressure garment design tool to monitor exerted pressures.

PubMed

Macintyre, Lisa; Ferguson, Rhona

2013-09-01

Pressure garments are used in the treatment of hypertrophic scarring following serious burns. The use of pressure garments is believed to hasten the maturation process, reduce pruritus associated with immature hypertrophic scars and prevent the formation of contractures over flexor joints. Pressure garments are normally made to measure for individual patients from elastic fabrics and are worn continuously for up to 2 years or until scar maturation. There are 2 methods of constructing pressure garments. The most common method, called the Reduction Factor method, involves reducing the patient's circumferential measurements by a certain percentage. The second method uses the Laplace Law to calculate the dimensions of pressure garments based on the circumferential measurements of the patient and the tension profile of the fabric. The Laplace Law method is complicated to utilise manually and no design tool is currently available to aid this process. This paper presents the development and suggested use of 2 new pressure garment design tools that will aid pressure garment design using the Reduction Factor and Laplace Law methods. Both tools calculate the pressure garment dimensions and the mean pressure that will be exerted around the body at each measurement point. Monitoring the pressures exerted by pressure garments and noting the clinical outcome would enable clinicians to build an understanding of the implications of particular pressures on scar outcome, maturation times and patient compliance rates. Once the optimum pressure for particular treatments is known, the Laplace Law method described in this paper can be used to deliver those average pressures to all patients. This paper also presents the results of a small scale audit of measurements taken for the fabrication of pressure garments in two UK hospitals. This audit highlights the wide range of pressures that are exerted using the Reduction Factor method and that manual pattern 'smoothing' can dramatically change the actual Reduction Factors used. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Clinical Evaluation of Protective Garments with Respect to Garment Characteristics and Manufacturer Label Information.

PubMed

Lichliter, Andrew; Weir, Victor; Heithaus, Robert Evans; Gipson, Sean; Syed, Almas; West, James; Rees, Chet

2017-01-01

To test operator exposures inside radiation protection garments in a simulated clinical setup, examining trends related to multiple characteristics. Sixteen garment models containing lead or nonlead materials and a suspended device (Zero-Gravity) were tested for operator exposure from X rays scattered from an acrylic patient phantom. Weight and surface area were determined. The operator phantom was a wooden frame containing a dosimeter in its cavity. Garments were draped over the frame, and the setup was placed in a typical working position. There was substantial variability in exposures for all garments, ranging from 0.52 to 13.8 µSv/h (mean, 5.39 µSv/h ± 3.82), with a 12-fold difference for garments labeled 0.5 mm Pb equivalent. Most of the especially poor protectors were nonlead, even when not lightweight. Nonlead models were not more protective per weight overall. For closed-back garments labeled 0.5 mm Pb equivalent, mean exposures were lower for lead than for nonlead materials (mean, 1.48 µSv/h ± 0.434 vs 6.26 µSv/h ± 5.13, respectively). Density per exposure -1 was lower for lead than nonlead materials in the 0.5-mm Pb equivalent group, counter to advertised claims. Open-back configurations were lighter than closed (3.3 kg vs 6.0 kg, respectively), with similar mean exposures (5.30 µSv/h vs 5.39 µSv/h, respectively). The lowest exposure was 0.52 µSv/h (9.8% of the mean of all garments) for the suspended device. Operator exposure in a realistic interventional setup is highly variable for similarly labeled protective garments, highlighting the necessity of internal validation when considering nonlead and lightweight models. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Pressure prediction model for compression garment design.

PubMed

Leung, W Y; Yuen, D W; Ng, Sun Pui; Shi, S Q

2010-01-01

Based on the application of Laplace's law to compression garments, an equation for predicting garment pressure, incorporating the body circumference, the cross-sectional area of fabric, applied strain (as a function of reduction factor), and its corresponding Young's modulus, is developed. Design procedures are presented to predict garment pressure using the aforementioned parameters for clinical applications. Compression garments have been widely used in treating burning scars. Fabricating a compression garment with a required pressure is important in the healing process. A systematic and scientific design method can enable the occupational therapist and compression garments' manufacturer to custom-make a compression garment with a specific pressure. The objectives of this study are 1) to develop a pressure prediction model incorporating different design factors to estimate the pressure exerted by the compression garments before fabrication; and 2) to propose more design procedures in clinical applications. Three kinds of fabrics cut at different bias angles were tested under uniaxial tension, as were samples made in a double-layered structure. Sets of nonlinear force-extension data were obtained for calculating the predicted pressure. Using the value at 0° bias angle as reference, the Young's modulus can vary by as much as 29% for fabric type P11117, 43% for fabric type PN2170, and even 360% for fabric type AP85120 at a reduction factor of 20%. When comparing the predicted pressure calculated from the single-layered and double-layered fabrics, the double-layered construction provides a larger range of target pressure at a particular strain. The anisotropic and nonlinear behaviors of the fabrics have thus been determined. Compression garments can be methodically designed by the proposed analytical pressure prediction model.

Fire Resistant, Moisture Barrier Membrane

NASA Technical Reports Server (NTRS)

St.Clair, Terry L. (Inventor)

2000-01-01

A waterproof and breathable, fire-resistant laminate is provided for use in tents, garments, shoes, and covers, especially in industrial, military and emergency situations. The laminate permits water vapor evaporation while simultaneously preventing liquid water penetration. Further, the laminate is fire-resistant and significantly reduces the danger of toxic compound production when exposed to flame or other high heat source. The laminate may be applied to a variety of substrates and is comprised of a silicone rubber and plurality of fire-resistant, inherently thermally-stable polyimide particles.

Fire Resistant, Moisture Barrier Membrane

NASA Technical Reports Server (NTRS)

St.Clair, Terry L. (Inventor)

1998-01-01

A waterproof and breathable, fire-resistant laminate is provided for use in tents, garments, shoes, and covers, especially in industrial, military and emergency situations. The laminate permits water vapor evaporation while simultaneously preventing liquid water penetration. Further, the laminate is fire-resistant and significantly reduces the danger of toxic compound production when exposed to flame or other high heat source. The laminate may be applied to a variety of substrates and is comprised of a silicone rubber and plurality of fire-resistant, inherently thermally-stable polyimide particles.

NASA Tech Briefs, January 2010

NASA Technical Reports Server (NTRS)

2010-01-01

Topics covered include: Cryogenic Flow Sensor; Multi-Sensor Mud Detection; Gas Flow Detection System; Mapping Capacitive Coupling Among Pixels in a Sensor Array; Fiber-Based Laser Transmitter for Oxygen A-Band Spectroscopy and Remote Sensing; Low-Profile, Dual-Wavelength, Dual-Polarized Antenna; Time-Separating Heating and Sensor Functions of Thermistors in Precision Thermal Control Applications; Cellular Reflectarray Antenna; A One-Dimensional Synthetic-Aperture Microwave Radiometer; Electrical Switching of Perovskite Thin-Film Resistors; Two-Dimensional Synthetic-Aperture Radiometer; Ethernet-Enabled Power and Communication Module for Embedded Processors; Electrically Variable Resistive Memory Devices; Improved Attachment in a Hybrid Inflatable Pressure Vessel; Electrostatic Separator for Beneficiation of Lunar Soil; Amorphous Rover; Space-Frame Antenna; Gear-Driven Turnbuckle Actuator; In-Situ Focusing Inside a Thermal Vacuum Chamber; Space-Frame Lunar Lander; Wider-Opening Dewar Flasks for Cryogenic Storage; Silicon Oxycarbide Aerogels for High-Temperature Thermal Insulation; Supercapacitor Electrolyte Solvents with Liquid Range Below -80 C; Designs and Materials for Better Coronagraph Occulting Masks; Fuel-Cell-Powered Vehicle with Hybrid Power Management; Fine-Water-Mist Multiple-Orientation-Discharge Fire Extinguisher; Fuel-Cell Water Separator; Turbulence and the Stabilization Principle; Improved Cloud Condensation Nucleus Spectrometer; Better Modeling of Electrostatic Discharge in an Insulator; Sub-Aperture Interferometers; Terahertz Mapping of Microstructure and Thickness Variations; Multiparallel Three-Dimensional Optical Microscopy; Stabilization of Phase of a Sinusoidal Signal Transmitted Over Optical Fiber; Vacuum-Compatible Wideband White Light and Laser Combiner Source System; Optical Tapers as White-Light WGM Resonators; EPR Imaging at a Few Megahertz Using SQUID Detectors; Reducing Field Distortion in Magnetic Resonance Imaging; Fluorogenic Cell-Based Biosensors for Monitoring Microbes; A Constant-Force Resistive Exercise Unit; GUI to Facilitate Research on Biological Damage from Radiation; On-Demand Urine Analyzer; More-Realistic Digital Modeling of a Human Body; and Advanced Liquid-Cooling Garment Using Highly Thermally Conductive Sheets.

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

NASA Astrophysics Data System (ADS)

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

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

The influence of the mould cooling temperature on the surface appearance and the internal quality of ESR ingots

NASA Astrophysics Data System (ADS)

Kubin, M.; Ofner, B.; Holzgruber, H.; Schneider, R.; Enzenhofer, D.; Filzwieser, A.; Konetschnik, S.

2016-07-01

One of the main benefits of the ESR process is to obtain an ingot surface which is smooth and allows a subsequent forging operation without any surface dressing. The main influencing factor on surface quality is the precise controlling of the process such as melt rate and electrode immersion depth. However, the relatively strong cooling effect of water as a cooling medium can result in the solidification of the meniscus of the liquid steel on the boundary liquid steel and slag which is most likely the origin of surface defects. The usage of different cooling media like ionic liquids, a salt solution which can be heated up to 250°C operating temperature might diminish the meniscus solidification phenomenon. This paper shows the first results of the usage of an ionic liquid as a mould cooling medium. In doing so, 210mm diameter ESR ingots were produced with the laboratory scale ESR furnace at the university of applied science using an ionic liquid cooling device developed by the company METTOP. For each trial melt different inlet and outlet temperatures of the ionic liquid were chosen and the impact on the surface appearance and internal quality were analyzed. Furthermore the influence on the energy balance is also briefly highlighted. Ultimately, an effect of the usage of ionic liquids as a cooling medium could be determined and these results will be described in detail within the scope of this paper.

Hemodynamic changes during whole body surface cooling and lower body negative pressure

NASA Technical Reports Server (NTRS)

Raven, P. B.; Pape, G.; Taylor, W. F.; Gaffney, F. A.; Blomqvist, C. G.

1981-01-01

Six young healthy male subjects were studied to evaluate the use of whole body surface cooling (WBSC) as an antiorthostatic intervention. Previous studies have demonstrated that perfusion of an Apollo cooling garment with 16 C water produced a significant increase in stroke volume and decrease in heart rate at rest and during lower body negative pressure (LBNP). However, optimal perfusion temperatures have not been determined. The present study examined the effects of WBSC using perfusion of water at a temperature of 10 C. This perfusion temperature produced a greater decrease in mean skin temperature than water at 16 C (4 C drop compared to 2 C). The hemodynamic effects were also more prominent with 10 C water as shown by the increase in stroke volume of 11% at rest and of 35% during LBNP at -50 torr compared to control measurements at ambient temperature. Heart rates were lowered significantly (8 beats/min) and systolic arterial blood pressure was higher (8 torr). Cooling with 10 C water produced a slight increase in muscle tone, reflected by a small but significant increase (+84 ml/min) in oxygen uptake. These data suggest that WBSC is an effective nonpharmacologic means of controlling preload and deserves further investigation as an antiorthostatic intervention.

Protective garment ventilation system

NASA Technical Reports Server (NTRS)

Lang, R. (Inventor)

1970-01-01

A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

Rocket nozzle coolant channel thermal analysis program (E25107)

NASA Technical Reports Server (NTRS)

Thompson, W. R.

1972-01-01

A complete description of the liquid cooled rocket nozzle analysis program (E25107) is presented, including a users manual, program listing, and a sample problem. The program is recommended for use in designing liquid cooled rocket nozzles. In addition, it is adaptable to any system in which a liquid-cooled tubular structure is used to contain and direct the flow of a hot gas.

Mixed cryogen cooling systems for HTS power applications: A status report of progress in Korea University

NASA Astrophysics Data System (ADS)

Song, Jung-Bin; Lee, Haigun

2012-12-01

A cooling system employing a solid cryogen (SC), such as solid nitrogen (SN2), was recently reported for high-temperature superconducting (HTS) applications. However, thermal contact between the SC and the HTS can be degraded by repeated overcurrent runs, resulting in 'thermal dry-out'. Novel cryogens, SC with small amounts of liquid cryogen, have been suggested to overcome this problem. Such cooling systems rely on the small amount of liquid cryogen to facilitate heat exchange so as to fully exploit the heat capacity of the solid cryogen. This paper presents a description and summary of recent activities at Korea University related to cooling systems employing mixed cryogens of solid-liquid nitrogen, solid argon-liquid nitrogen, and solid nitrogen-liquid neon.

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

Vaporization Would Cool Primary Battery

NASA Technical Reports Server (NTRS)

Bhandari, Pradeep; Miyake, Robert N.

1991-01-01

Temperature of discharging high-power-density primary battery maintained below specified level by evaporation of suitable liquid from jacket surrounding battery, according to proposal. Pressure-relief valve regulates pressure and boiling temperature of liquid. Less material needed in cooling by vaporization than in cooling by melting. Technique used to cool batteries in situations in which engineering constraints on volume, mass, and location prevent attachment of cooling fins, heat pipes, or like.

A protocol for monitoring soft tissue motion under compression garments during drop landings.

PubMed

Mills, Chris; Scurr, Joanna; Wood, Louise

2011-06-03

This study used a single-subject design to establish a valid and reliable protocol for monitoring soft tissue motion under compression garments during drop landings. One male participant performed six 40 cm drop landings onto a force platform, in three compression conditions (none, medium high). Five reflective markers placed on the thigh under the compression garment and five over the garment were filmed using two cameras (1000 Hz). Following manual digitisation, marker coordinates were reconstructed and their resultant displacements and maximum change in separation distance between skin and garment markers were calculated. To determine reliability of marker application, 35 markers were attached to the thigh over the high compression garment and filmed. Markers were then removed and re-applied on three occasions; marker separation and distance to thigh centre of gravity were calculated. Results showed similar ground reaction forces during landing trials. Significant reductions in the maximum change in separation distance between markers from no compression to high compression landings were reported. Typical errors in marker movement under and over the garment were 0.1mm in medium and high compression landings. Re-application of markers showed mean typical errors of 1mm in marker separation and <3mm relative to thigh centre of gravity. This paper presents a novel protocol that demonstrates sufficient sensitivity to detect reductions in soft tissue motion during landings in high compression garments compared to no compression. Additionally, markers placed under or over the garment demonstrate low variance in movement, and the protocol reports good reliability in marker re-application. Copyright © 2011 Elsevier Ltd. All rights reserved.

Contribution of garment fit and style to thermal comfort at the lower body

NASA Astrophysics Data System (ADS)

Mert, Emel; Böhnisch, Sonja; Psikuta, Agnes; Bueno, Marie-Ange; Rossi, René M.

2016-12-01

The heat and mass transfer between the human body and the environment is not only affected by the properties of the fabric, but also by the size of the air gap thickness and the magnitude of the contact area between the body and garment. In this clothing-human-environment system, there is also an interaction between the clothing and the physiological response of the wearer. Therefore, the aim of this study was to evaluate the distribution of the air gap thickness and the contact area for the male lower body in relation to the garment fit and style using a three-dimensional (3D) body scanning method with a manikin. Moreover, their relation with the physiological response of the lower body was analysed using the physiological modelling. The presented study showed that the change in the air gap thickness and the contact area due to garment fit was greater for legs than the pelvis area due to regional differences of the body. Furthermore, the garment style did not have any effect on the core temperature or total water loss of the lower body, whereas the effect of garment fit on the core temperature and total water loss of lower body was observed only for 40 °C of ambient temperature. The skin temperatures were higher for especially loose garments at thigh than the tight garments. Consequently, the results of this study indicated that the comfort level of the human body for a given purpose can be adjusted by selection of fabric type and the design of ease allowances in the garment depending on the body region.

Heat dissipation for microprocessor using multiwalled carbon nanotubes based liquid.

PubMed

Hung Thang, Bui; Trinh, Pham Van; Chuc, Nguyen Van; Khoi, Phan Hong; Minh, Phan Ngoc

2013-01-01

Carbon nanotubes (CNTs) are one of the most valuable materials with high thermal conductivity (2000 W/m · K compared with thermal conductivity of Ag 419 W/m · K). This suggested an approach in applying the CNTs in thermal dissipation system for high power electronic devices, such as computer processor and high brightness light emitting diode (HB-LED). In this work, multiwalled carbon nanotubes (MWCNTs) based liquid was made by COOH functionalized MWCNTs dispersed in distilled water with concentration in the range between 0.2 and 1.2 gram/liter. MWCNT based liquid was used in liquid cooling system to enhance thermal dissipation for computer processor. By using distilled water in liquid cooling system, CPU's temperature decreases by about 10°C compared with using fan cooling system. By using MWCNT liquid with concentration of 1 gram/liter MWCNTs, the CPU's temperature decreases by 7°C compared with using distilled water in cooling system. Theoretically, we also showed that the presence of MWCNTs reduced thermal resistance and increased the thermal conductivity of liquid cooling system. The results have confirmed the advantages of the MWCNTs for thermal dissipation systems for the μ -processor and other high power electronic devices.

Immersion Cooling of Electronics in DoD Installations

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

Coles, Henry; Herrlin, Magnus

A considerable amount of energy is consumed to cool electronic equipment in data centers. A method for substantially reducing the energy needed for this cooling was demonstrated. The method involves immersing electronic equipment in a non-conductive liquid that changes phase from a liquid to a gas. The liquid used was 3M Novec 649. Two-phase immersion cooling using this liquid is not viable at this time. The primary obstacles are IT equipment failures and costs. However, the demonstrated technology met the performance objectives for energy efficiency and greenhouse gas reduction. Before commercialization of this technology can occur, a root cause analysismore » of the failures should be completed, and the design changes proven.« less

Thermal Conductivity of Copoly(ethylene vinyl acetate)/Nano-Filler Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G.; Lin, Y.; Sun, Y. P.

2007-01-01

The development of flexible, thermally conductive fabrics and plastic tubes for the Liquid Cooling and Ventilation Garment (LCVG) are needed to reduce weight and improve the mobility, comfort, and performance of future spacesuits. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As a continuation of our work on the improvement of thermal conductivity (TC) of polymeric materials, nanocomposites were prepared from copoly(ethylene vinyl acetate), trade name Elvax 260TradeMark), metallized carbon nanofibers (CNFs), nickel (Ni) nanostrands, boron nitride both alone and as mixtures with aluminum powder. The nanocomposites were prepared by melt mixing at various loading levels and subsequently fabricated into several material forms (i.e., ribbons, tubes, and compression molded plaques) for analysis. Ribbons and tubes were extruded to form samples in which the nanoparticles were aligned in the direction of flow. The degree of dispersion and alignment of the nanoparticles were investigated using high-resolution scanning electron microscopy. Tensile properties of the aligned samples were determined at room temperature. TC measurements were performed using a laser flash (Nanoflash(TradeMark) technique. The TC of the samples was measured in both the direction of alignment as well as transverse. Tubing of comparable dimensions to that used in the LCVG was extruded from select compositions and the thermal conductivities of the tubes measured.

Space Suit Radiator Performance in Lunar and Mars Environments

NASA Technical Reports Server (NTRS)

Nabity, James; Mason, Georgia; Copeland, Robert; Libberton, Kerry; Stephan, Ryan; Trevino, Luis; Paul, Heather

2005-01-01

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to thus become the single largest expendable during an eight hour EVA. We can significantly reduce the amount of expendable water consumed in the sublimator by using a radiator to reject heat from the Astronaut during an EVA. Last year we reported on the design and initial operational assessment tests of our novel radiator designated the Radiator And Freeze Tolerant heat eXchanger (RAFT-X). Herein, we report on tests conducted in the NASA Johnson Space Center Chamber E Thermal Vacuum Test Facility. Up to 260 W (900 Btu/h) of heat were rejected in Lunar and Mars environments with temperatures as cold as -170 C (- 275 F). Further, the RAFT-X endured several freeze / thaw cycles and in fact, the heat exchanger was completely frozen three times without any apparent damage to the unit.

Combined refrigeration system with a liquid pre-cooling heat exchanger

DOEpatents

Gaul, Christopher J.

2003-07-01

A compressor-pump unit for use in a vapor-compression refrigeration system is provided. The compressor-pump unit comprises a driving device including a rotatable shaft. A compressor is coupled with a first portion of the shaft for compressing gaseous refrigerant within the vapor-compression refrigeration system. A liquid pump is coupled with a second portion of the shaft for receiving liquid refrigerant having a first pressure and for discharging the received liquid refrigerant at a second pressure with the second pressure being higher than the first pressure by a predetermined amount such that the discharged liquid refrigerant is subcooled. A pre-cooling circuit is connected to the liquid pump with the pre-cooling circuit being exposed to the gaseous refrigerant whereby the gaseous refrigerant absorbs heat from the liquid refrigerant, prior to the liquid refrigerant entering the liquid pump.

Wing-Nacelle-Propeller Tests - Comparative Tests of Liquid-Cooled and Air-Cooled Engine Nacelles

NASA Technical Reports Server (NTRS)

Wood, Donald H.

1934-01-01

This report gives the results of measurements of the lift, drag, and propeller characteristics of several wing and nacelle combinations with a tractor propeller. The nacelles were so located that the propeller was about 31% of the wing chord directly ahead of the leading edge of the wing, a position which earlier tests (NASA Report No. 415) had shown to be efficient. The nacelles were scale models of an NACA cowled nacelle for a radial air-cooled engine, a circular nacelle with the V-type engine located inside and the radiator for the cooling liquid located inside and the radiator for the type, and a nacelle shape simulating the housing which would be used for an extension shaft if the engine were located entirely within the wing. The propeller used in all cases was a 4-foot model of Navy No. 4412 adjustable metal propeller. The results of the tests indicate that, at the angles of attack corresponding to high speeds of flight, there is no marked advantage of one type of nacelle over the others as far as low drag is concerned, since the drag added by any of the nacelles in the particular location ahead of the wing is very small. The completely cowled nacelle for a radial air-cooled engine appears to have the highest drag, the liquid-cooled engine appears to have the highest drag, the liquid-cooled engine nacelle with external radiator slightly less drag. The liquid-cooled engine nacelle with radiator in the cowling hood has about half the drag of the cowled radial air-cooled engine nacelle. The extension-shaft housing shows practically no increase in drag over that of the wing alone. A large part of the drag of the liquid-cooled engine nacelle appears to be due to the external radiator. The maximum propulsive efficiency for a given propeller pitch setting is about 2% higher for the liquid-cooled engine nacelle with the radiator in the cowling hood than that for the other cowling arrangements.

Method and apparatus for high-efficiency direct contact condensation

DOEpatents

Bharathan, D.; Parent, Y.; Hassani, A.V.

1999-07-20

A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions, and the geometric properties of the contact medium. 39 figs.

Method and apparatus for high-efficiency direct contact condensation

DOEpatents

Bharathan, Desikan; Parent, Yves; Hassani, A. Vahab

1999-01-01

A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions. and the geometric properties of the contact medium.

Evaluation of three-dimensional virtual perception of garments

NASA Astrophysics Data System (ADS)

Aydoğdu, G.; Yeşilpinar, S.; Erdem, D.

2017-10-01

In recent years, three-dimensional design, dressing and simulation programs came into prominence in the textile industry. By these programs, the need to produce clothing samples for every design in design process has been eliminated. Clothing fit, design, pattern, fabric and accessory details and fabric drape features can be evaluated easily. Also, body size of virtual mannequin can be adjusted so more realistic simulations can be created. Moreover, three-dimensional virtual garment images created by these programs can be used while presenting the product to end-user instead of two-dimensional photograph images. In this study, a survey was carried out to investigate the visual perception of consumers. The survey was conducted for three different garment types, separately. Questions about gender, profession etc. was asked to the participants and expected them to compare real samples and artworks or three-dimensional virtual images of garments. When survey results were analyzed statistically, it is seen that demographic situation of participants does not affect visual perception and three-dimensional virtual garment images reflect the real sample characteristics better than artworks for each garment type. Also, it is reported that there is no perception difference depending on garment type between t-shirt, sweatshirt and tracksuit bottom.

A right to live: girl workers in the Bangladeshi garment industry.

PubMed

Wahra, G N; Rahman, F

1995-06-01

According to a survey conducted in 1989, there are 772 approved and registered garment factories in Bangladesh. These factories employ approximately 300,000 individuals, 90% of whom are women. A more recent estimate in a Bangladeshi newspaper, however, posits that up to five million people are directly or indirectly dependent upon the garment industry. Many of the women who work in Bangladesh's garment factories are under age 15 years. In some countries, such as the US, the employment of such young individuals constitutes a violation of child labor laws. Therefore, under the Harkin Bill, the US will no longer import garments produced by children younger than age 15 years. Many garment workers under age 15 years have already been put out of work or will soon be terminated. The authors explain that while the intent of the Harkin Bill may be to protect children, it is difficult to adopt the moral high ground in a poor country like Bangladesh. Regardless of one's age in Bangladesh, having a job may be the only way to survive. No job often means no food or shelter. The authors discuss women in the garment industry, one girl's case, alternative employment opportunities, and the future.

RF cavity using liquid dielectric for tuning and cooling

DOEpatents

Popovic, Milorad [Warrenville, IL; Johnson, Rolland P [Newport News, VA

2012-04-17

A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

Wet/dry cooling tower and method

DOEpatents

Glicksman, Leon R.; Rohsenow, Warren R.

1981-01-01

A wet/dry cooling tower wherein a liquid to-be-cooled is flowed along channels of a corrugated open surface or the like, which surface is swept by cooling air. The amount of the surface covered by the liquid is kept small compared to the dry part thereof so that said dry part acts as a fin for the wet part for heat dissipation.

High-Thermal-Conductivity Fabrics

NASA Technical Reports Server (NTRS)

Chibante, L. P. Felipe

2012-01-01

Heat management with common textiles such as nylon and spandex is hindered by the poor thermal conductivity from the skin surface to cooling surfaces. This innovation showed marked improvement in thermal conductivity of the individual fibers and tubing, as well as components assembled from them. The problem is centered on improving the heat removal of the liquid-cooled ventilation garments (LCVGs) used by astronauts. The current design uses an extensive network of water-cooling tubes that introduces bulkiness and discomfort, and increases fatigue. Range of motion and ease of movement are affected as well. The current technology is the same as developed during the Apollo program of the 1960s. Tubing material is hand-threaded through a spandex/nylon mesh layer, in a series of loops throughout the torso and limbs such that there is close, form-fitting contact with the user. Usually, there is a nylon liner layer to improve comfort. Circulating water is chilled by an external heat exchanger (sublimator). The purpose of this innovation is to produce new LCVG components with improved thermal conductivity. This was addressed using nanocomposite engineering incorporating high-thermalconductivity nanoscale fillers in the fabric and tubing components. Specifically, carbon nanotubes were added using normal processing methods such as thermoplastic melt mixing (compounding twin screw extruder) and downstream processing (fiber spinning, tubing extrusion). Fibers were produced as yarns and woven into fabric cloths. The application of isotropic nanofillers can be modeled using a modified Nielsen Model for conductive fillers in a matrix based on Einstein s viscosity model. This is a drop-in technology with no additional equipment needed. The loading is limited by the ability to maintain adequate dispersion. Undispersed materials will plug filtering screens in processing equipment. Generally, the viscosity increases were acceptable, and allowed the filled polymers to still be processed.The novel feature is that fabrics do not inherently possess good thermal conductivity. In fact, fabrics are used for thermal insulation, not heat removal. The technology represents the first material that is a wearable fabric, based on company textiles and materials that will significantly conduct heat.

Numerical simulation of the heat transfer at cooling a high-temperature metal cylinder by a flow of a gas-liquid medium

NASA Astrophysics Data System (ADS)

Makarov, S. S.; Lipanov, A. M.; Karpov, A. I.

2017-10-01

The numerical modeling results for the heat transfer during cooling a metal cylinder by a gas-liquid medium flow in an annular channel are presented. The results are obtained on the basis of the mathematical model of the conjugate heat transfer of the gas-liquid flow and the metal cylinder in a two-dimensional nonstationary formulation accounting for the axisymmetry of the cooling medium flow relative to the cylinder longitudinal axis. To solve the system of differential equations the control volume approach is used. The flow field parameters are calculated by the SIMPLE algorithm. To solve iteratively the systems of linear algebraic equations the Gauss-Seidel method with under-relaxation is used. The results of the numerical simulation are verified by comparing the results of the numerical simulation with the results of the field experiment. The calculation results for the heat transfer parameters at cooling the high-temperature metal cylinder by the gas-liquid flow are obtained with accounting for evaporation. The values of the rate of cooling the cylinder by the laminar flow of the cooling medium are determined. The temperature change intensity for the metal cylinder is analyzed depending on the initial velocity of the liquid flow and the time of the cooling process.

Variable-thermoinsulation garments with a microprocessor temperature controller.

PubMed

Kurczewska, Agnieszka; Leánikowski, Jacek

2008-01-01

This paper presents the concept of active variable thermoinsulation clothing for users working in low temperatures. Those garments contain heating inserts regulated by a microprocessor temperature controller. This paper also presents the results of tests carried out on the newly designed garments.

Contribution of garment fit and style to thermal comfort at the lower body.

PubMed

Mert, Emel; Böhnisch, Sonja; Psikuta, Agnes; Bueno, Marie-Ange; Rossi, René M

2016-12-01

The heat and mass transfer between the human body and the environment is not only affected by the properties of the fabric, but also by the size of the air gap thickness and the magnitude of the contact area between the body and garment. In this clothing-human-environment system, there is also an interaction between the clothing and the physiological response of the wearer. Therefore, the aim of this study was to evaluate the distribution of the air gap thickness and the contact area for the male lower body in relation to the garment fit and style using a three-dimensional (3D) body scanning method with a manikin. Moreover, their relation with the physiological response of the lower body was analysed using the physiological modelling. The presented study showed that the change in the air gap thickness and the contact area due to garment fit was greater for legs than the pelvis area due to regional differences of the body. Furthermore, the garment style did not have any effect on the core temperature or total water loss of the lower body, whereas the effect of garment fit on the core temperature and total water loss of lower body was observed only for 40 °C of ambient temperature. The skin temperatures were higher for especially loose garments at thigh than the tight garments. Consequently, the results of this study indicated that the comfort level of the human body for a given purpose can be adjusted by selection of fabric type and the design of ease allowances in the garment depending on the body region.

The views of children and young people on the use of silk garments for the treatment of eczema: a nested qualitative study within the CLOTHing for the relief of Eczema Symptoms (CLOTHES) randomized controlled trial.

PubMed

Wake, E V; Batchelor, J; Lawton, S; Thomas, K S; Harrison, E F; Cowdell, F C

2018-01-01

Many children suffer with skin diseases but to date most dermatological research has been done 'on' rather than 'with' children; in this study we actively sought the experiences of children and young people. Atopic eczema (AE) is a chronic, itchy, inflammatory skin condition that affects around 20% of children and can impact on the health and wellbeing of children and their families. The role of specialist clothing in the management of AE is poorly understood. The aim of this study, which was nested in a randomized controlled trial, was to qualitatively examine child participants' experiences of using silk garments for the treatment of AE. Eighteen children aged 5-15 years, who took part in the CLOTHing for the relief of Eczema Symptoms (CLOTHES) trial, participated in age-appropriate individual interviews or focus groups. Thematic analysis generated four themes directly related to the silk garments: (i) expectations of the garments; (ii) wearing the garments; (iii) asking if the garments helped; and (iv) thoughts about the garments. The conclusions from this nested qualitative study are that there was some limited improvement in eczema for some children but that the hoped-for 'miracle cure' did not transpire. A mixed picture of knowledge, beliefs and experiences of using the silk garments emerged. Engaging children in the evaluation of the garments provided first-hand nuanced insights that enhanced understanding of the CLOTHES study as a whole. This nested study demonstrates that children can and indeed want to be engaged in dermatological research in meaningful ways that add to our understanding of treatment options. © 2017 British Association of Dermatologists.

Optimization analysis of the motor cooling method in semi-closed single screw refrigeration compressor

NASA Astrophysics Data System (ADS)

Wang, Z. L.; Shen, Y. F.; Wang, Z. B.; Wang, J.

2017-08-01

Semi-closed single screw refrigeration compressors (SSRC) are widely used in refrigeration and air conditioning systems owing to the advantages of simple structure, balanced forces on the rotor, high volumetric efficiency and so on. In semi-closed SSRCs, motor is often cooled by suction gas or injected refrigerant liquid. Motor cooling method will changes the suction gas temperature, this to a certain extent, is an important factor influencing the thermal dynamic performance of a compressor. Thus the effects of motor cooling method on the performance of the compressor must be studied. In this paper mathematical models of motor cooling process by using these two methods were established. Influences of motor cooling parameters such as suction gas temperature, suction gas quantity, temperature of the injected refrigerant liquid and quantity of the injected refrigerant liquid on the thermal dynamic performance of the compressor were analyzed. The performances of the compressor using these two kinds of motor cooling methods were compared. The motor cooling capacity of the injected refrigerant liquid is proved to be better than the suction gas. All analysis results obtained can be useful for optimum design of the motor cooling process to improve the efficiency and the energy efficiency of the compressor.

Physical and psychological health problems of garment workers in the Fiji.

PubMed

Chand, Anand

2006-09-01

This paper unravels the physical and psychological health problems of garment workers in Fiji. It is based on research work done between 1997-2007. Majority of the garment workers are women. The main physical health problems faced by workers are: 'Occupational fatigue syndrome', body pains, obesity, and bladder and kidney problems. The major psychological problems work stress and depression. Work stress and depression are caused by 'intensification of work' to meet daily targets, strict factory rules and regulations, poor pay, poor working conditions, in-human abuse, and fear of job loss. Since garment workers do not have much education and skills they have no other option but to work for the garment industry and suffer in silence.

DEMONSTRATION OF WATERBASED PLATEN ADHESIVES FOR GARMENT SCREEN PRINTERS

EPA Science Inventory

The paper discusses a demonstration of waterbased platen adhesives as a viable alternative to the organic-based aerosol adhesives that are predominantly used by garment screen printers to affix garments or fabric pieces to print platens. o demonstrate this, the effectiveness of s...

Biological Isolation Garment

NASA Technical Reports Server (NTRS)

1976-01-01

A spinoff of astronaut's biological garment will allow hospital patients who are highly vulnerable to infection to leave their sterile habitats for several hours, carrying their germ free environment with them. Garments can be used in any of some 200 hospitals where isolation rooms are installed to treat leukemia.

An insight into Newton's cooling law using fractional calculus

NASA Astrophysics Data System (ADS)

Mondol, Adreja; Gupta, Rivu; Das, Shantanu; Dutta, Tapati

2018-02-01

For small temperature differences between a heated body and its environment, Newton's law of cooling predicts that the instantaneous rate of change of temperature of any heated body with respect to time is proportional to the difference in temperature of the body with the ambient, time being measured in integer units. Our experiments on the cooling of different liquids (water, mustard oil, and mercury) did not fit the theoretical predictions of Newton's law of cooling in this form. The solution was done using both Caputo and Riemann-Liouville type fractional derivatives to check if natural phenomena showed any preference in mathematics. In both cases, we find that cooling of liquids has an identical value of the fractional derivative of time that increases with the viscosity of the liquid. On the other hand, the cooling studies on metal alloys could be fitted exactly by integer order time derivative equations. The proportionality constant between heat flux and temperature difference was examined with respect to variations in the depth of liquid and exposed surface area. A critical combination of these two parameters signals a change in the mode of heat transfer within liquids. The equivalence between the proportionality constants for the Caputo and Riemann-Liouville type derivatives is established.

Experimental Investigation of Shear Driven Liquid Films for Film Cooling Applications in Liquid Rocket Engines

DTIC Science & Technology

2012-12-01

6 1.1.1 Differences Between Hot-Fire at Subcritical Conditions and Cold Flow ........10 1.1.2 Differences at Supercritical Conditions...cooling. 1.1.2 Differences at Supercritical Conditions Liquid film cooling is expected to behave even more differently at supercritical conditions...phase will behave more like the mixing of two gases of dissimilar densities. Once enough heat is imparted into the supercritical fuel film, it

Liquid-cooling technology for gas turbines - Review and status

NASA Technical Reports Server (NTRS)

Van Fossen, G. J., Jr.; Stepka, F. S.

1978-01-01

After a brief review of past efforts involving the forced-convection cooling of gas turbines, the paper surveys the state of the art of the liquid cooling of gas turbines. Emphasis is placed on thermosyphon methods of cooling, including those utilizing closed, open, and closed-loop thermosyphons; other methods, including sweat, spray and stator cooling, are also discussed. The more significant research efforts, design data, correlations, and analytical methods are mentioned and voids in technology are summarized.

Analysis of temperature distribution in liquid-cooled turbine blades

NASA Technical Reports Server (NTRS)

Livingood, John N B; Brown, W Byron

1952-01-01

The temperature distribution in liquid-cooled turbine blades determines the amount of cooling required to reduce the blade temperature to permissible values at specified locations. This report presents analytical methods for computing temperature distributions in liquid-cooled turbine blades, or in simplified shapes used to approximate sections of the blade. The individual analyses are first presented in terms of their mathematical development. By means of numerical examples, comparisons are made between simplified and more complete solutions and the effects of several variables are examined. Nondimensional charts to simplify some temperature-distribution calculations are also given.

Thermal comfort following immersion.

PubMed

Guéritée, Julien; Redortier, Bernard; House, James R; Tipton, Michael J

2015-02-01

Unlike thermal comfort in air, little research has been undertaken exploring thermal comfort around water sports. We investigated the impact of swimming and cooling in air after swimming on thermal comfort. After 10 min of swimming-and-resting cycles in 28°C water, volunteers wearing two types of garments or in swim briefs, faced winds in 24°C air, at rest or when stepping. Thermal comfort was significantly higher during swimming than resting. Post-immersion, following maximum discomfort, in 45 of 65 tests thermal comfort improved although mean skin temperature was still cooling (0.26 [SD 0.19] °C·min(-1) - max was 0.89°C·min(-1)). When thermal comfort was re-established mean skin temperature was lower than at maximal discomfort in 39 of 54 tests (0.81 [SD 0.58] °C - max difference was 2.68°C). The reduction in thermal discomfort in this scenario could be due to the adaptation of thermoreceptors, or to reductions in cooling rates to levels where discomfort was less stimulated. The relief from the recent discomfort may explain why, later, thermal comfort returned to initial levels in spite of poorer thermal profiles. Copyright © 2014 Elsevier Inc. All rights reserved.

Gauging Systems Monitor Cryogenic Liquids

NASA Technical Reports Server (NTRS)

2009-01-01

Rocket fuel needs to stay cool - super cool, in fact. The ability to store gas propellants like liquid hydrogen and oxygen at cryogenic temperatures (below -243 F) is crucial for space missions in order to reduce their volumes and allow their storage in smaller (and therefore, less costly) tanks. The Agency has used these cryogenic fluids for vehicle propellants, reactants, and life support systems since 1962 with the Centaur upper stage rocket, which was powered with liquid oxygen and liquid hydrogen. During proposed long-duration missions, super-cooled fluids will also be used in space power systems, spaceports, and lunar habitation systems. In the next generation of launch vehicles, gaseous propellants will be cooled to and stored for extended periods at even colder temperatures than currently employed via a process called densification. Densification sub-cools liquids to temperatures even closer to absolute zero (-459 F), increasing the fluid s density and shrinking its volume beyond common cryogenics. Sub-cooling cryogenic liquid hydrogen, for instance, from 20 K (-423 F) to 15 K (-432.4 F) reduces its mass by 10 percent. These densified liquid gases can provide more cost savings from reduced payload volume. In order to benefit from this cost savings, the Agency is working with private industry to prevent evaporation, leakage, and other inadvertent loss of liquids and gases in payloads - requiring new cryogenic systems to prevent 98 percent (or more) of boil-off loss. Boil-off occurs when cryogenic or densified liquids evaporate, and is a concern during launch pad holds. Accurate sensing of propellants aboard space vehicles is also critical for proper engine shutdown and re-ignition after launch, and zero boil-off fuel systems are also in development for the Altair lunar lander.

30 CFR 250.217 - What solid and liquid wastes and discharges information and cooling water intake information must...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What solid and liquid wastes and discharges... of Exploration Plans (ep) § 250.217 What solid and liquid wastes and discharges information and cooling water intake information must accompany the EP? The following solid and liquid wastes and...

Passive cooling safety system for liquid metal cooled nuclear reactors

DOEpatents

Hunsbedt, Anstein; Boardman, Charles E.; Hui, Marvin M.; Berglund, Robert C.

1991-01-01

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of partitions surrounding the reactor vessel in spaced apart relation forming intermediate areas for circulating heat transferring fluid which remove and carry away heat from the reactor vessel. The passive cooling system includes a closed primary fluid circuit through the partitions surrounding the reactor vessel and a partially adjoining secondary open fluid circuit for carrying transferred heat out into the atmosphere.

Indirect passive cooling system for liquid metal cooled nuclear reactors

DOEpatents

Hunsbedt, Anstein; Boardman, Charles E.

1990-01-01

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting from fuel decay during reactor shutdown. The passive cooling system comprises a plurality of partitions surrounding the reactor vessel in spaced apart relation forming intermediate areas for circulating heat transferring fluid which remove and carry away heat from the reactor vessel. The passive cooling system includes a closed primary fluid circuit through the partitions surrounding the reactor vessel and a partially adjoining secondary open fluid circuit for carrying transferred heat out into the atmosphere.

Liquid-liquid phase separation and solidification behavior of Al55Bi36Cu9 monotectic alloy with different cooling rates

NASA Astrophysics Data System (ADS)

Bo, Lin; Li, Shanshan; Wang, Lin; Wu, Di; Zuo, Min; Zhao, Degang

2018-03-01

The cooling rate has a significant effect on the solidification behavior and microstructure of monotectic alloy. In this study, different cooling rate was designed through casting in the copper mold with different bore diameters. The effects of different cooling rate on the solidification behavior of Al55Bi36Cu9 (at.%) immiscible alloy have been investigated. The liquid-liquid phase separation of Al55Bi36Cu9 immiscible alloy melt was investigated by resistivity test. The solidification microstructure and phase analysis of Al55Bi36Cu9 immiscible alloy were performed by the SEM and XRD, respectively. The results showed that the liquid-liquid phase separation occurred in the solidification of Al55Bi36Cu9 monotectic melt from 917 °C to 653 °C. The monotectic temperature, liquid phase separation temperature and immiscibility zone of Al55Bi36Cu9 monotectic alloy was lower than those of Al-Bi binary monotectic alloy. The solidification morphology of Al55Bi36Cu9 monotectic alloy was very sensitive to the cooling rate. The Al/Bi core-shell structure formed when Al55Bi36Cu9 melt was cast in the copper mold with a 8 mm bore diameter.

High-Efficiency Helical Coil Electromagnetic Launcher

DTIC Science & Technology

2006-08-31

significant launcher performance benefits by super-cooling the conductor in the armature (i.e., liquid nitrogen temperatures). 20061102530 14. ABSTRACT...i.e., liquid nitrogen temperatures). 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION 18. NUMBER 19a. NAME OF RESPONSIBLE PERSON...31 Liquid Nitrogen Cooled Armature

Standardized Curriculum for Commercial Garment and Apparel Construction.

ERIC Educational Resources Information Center

Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

Standardized curricula are provided for two courses for the secondary vocational education program in Mississippi: commercial garment and apparel construction I and II. The seven units in commercial garment and apparel construction I are as follows: orientation; securing a job; human relations; safety; maintenance; needle trade techniques; and…

Perceived Fashionability of a Garment as Inferred from the Age and Body Type of the Wearer.

ERIC Educational Resources Information Center

Clayton, Ruth; And Others

1987-01-01

Ninety college-aged females rated the fashionability of six garments worn by nine models representing three age levels and three body types. Results show respondents used age and body type cues as well as fashion detail to judge garment fashionability. (Author/CH)

76 FR 27007 - Steel Wire Garment Hangers From the People's Republic of China: Affirmative Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers... Administration, Department of Commerce. Preliminary Determination We preliminarily determine that steel wire... Act of 1930, as amended (``the Act''). See Notice of Antidumping Duty Order: Steel Wire Garment...

78 FR 7452 - Steel Wire Garment Hangers From Vietnam; Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-01

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-487 and 731-TA-1198 (Final)] Steel Wire...), that an industry in the United States is materially injured by reason of imports of steel wire garment... duty orders on steel wire garment hangers from Vietnam. Background The Commission instituted these...

Comprehensive evaluation of garment assembly line with simulation

NASA Astrophysics Data System (ADS)

Xu, Y.; Thomassey, S.; Chen, Y.; Zeng, X.

2017-10-01

In this paper, a comprehensive evaluation system is established to assess the garment production performance. It is based on performance indicators and supported with the corresponding results obtained by manual calculation or computer simulation. The assembly lines of a typical men’s shirt are taken as the study objects. With the comprehensive evaluation results, garments production arrangement scenarios are better analysed and then the appropriate one is supposed to be put into actual production. This will be a guidance given to companies on quick decision-making and multi-objective optimization of garment production.

Helium dilution refrigeration system

DOEpatents

Roach, Patrick R.; Gray, Kenneth E.

1988-01-01

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains .sup.3 He and .sup.4 He liquids which are precooled by a coupled container containing .sup.3 He liquid, enabling the phase separation of a .sup.3 He rich liquid phase from a dilute .sup.3 He-.sup.4 He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the .sup.3 He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute .sup.3 He-.sup.4 He liquid phase.

Helium dilution refrigeration system

DOEpatents

Roach, P.R.; Gray, K.E.

1988-09-13

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

Reproducibility of repeated measurements with the Kikuhime pressure sensor under pressure garments in burn scar treatment.

PubMed

Van den Kerckhove, Eric; Fieuws, Steffen; Massagé, Patrick; Hierner, Robert; Boeckx, Willy; Deleuze, Jean-Paul; Laperre, Jan; Anthonissen, Mieke

2007-08-01

This study investigated the reproducibility of repeated measurements with the Kikuhime pressure sensor under two different types of pressure garments used in the treatment and prevention of scars after burns. Also efficiency of garments was assessed in clinical circumstances by assessing pressure loss and residual pressure after 1 month. Intra- and inter-observer reproducibility and repeated measurements with 1-month time lapse were examined on 55 sites in 26 subjects by means of intra-class correlation coefficients and standard error of measurements. Results showed good to excellent ICC and low SEMs in the two conditions. There was a significant difference in pressure after 1 month between elastic tricot and weft knit garments, although evolution of pressure loss after 1 month was similar. Concerning different locations, there was a significant difference in pressure loss after 1 month between gloves and sleeves with the largest pressure loss for sleeves. Considering these results we concluded that the Kikuhime pressure sensor provides valid and reliable information and can be used in comparative clinical trials to evaluate pressure garments used in burn scar treatment. Secondly, elastic tricot garments in our study tended to have higher clinical pressures but both types of garments had similar pressure loss over time.

Application of the diagnostic radiological index of protection to protective garments

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

Pasciak, Alexander S.; Jones, A. Kyle, E-mail: kyle.jones@mdanderson.org; Wagner, Louis K.

2015-02-15

Purpose: Previously, the diagnostic radiological index of protection (DRIP) was proposed as a metric for quantifying the protective value of radioprotective garments. The DRIP is a weighted sum of the percent transmissions of different radiation beams through a garment. Ideally, the beams would represent the anticipated stray radiation encountered during clinical use. However, it is impractical to expect a medical physicist to possess the equipment necessary to accurately measure transmission of scattered radiation. Therefore, as a proof of concept, the authors tested a method that applied the DRIP to clinical practice. Methods: Primary beam qualities used in interventional cardiology andmore » radiology were observed and catalogued. Based on the observed range of beam qualities, five representative clinical primary beam qualities, specified by kV and added filtration, were selected for this evaluation. Monte Carlo simulations were performed using these primary beams as source definitions to generate scattered spectra from the clinical primary beams. Using numerical optimization, ideal scatter mimicking primary beams, specified by kV and added aluminum filtration, were matched to the scattered spectra according to half- and quarter-value layers and spectral shape. To within reasonable approximation, these theoretical scatter-mimicking primary beams were reproduced experimentally in laboratory x ray beams and used to measure transmission through pure lead and protective garments. For this proof of concept, the DRIP for pure lead and the garments was calculated by assigning equal weighting to percent transmission measurements for each of the five beams. Finally, the areal density of lead and garments was measured for consideration alongside the DRIP to assess the protective value of each material for a given weight. Results: The authors identified ideal scatter mimicking primary beams that matched scattered spectra to within 0.01 mm for half- and quarter-value layers in copper and within 5% for the shape function. The corresponding experimental scatter-mimicking primary beams matched the Monte Carlo generated scattered spectra with maximum deviations of 6.8% and 6.6% for half- and quarter-value layers. The measured DRIP for 0.50 mm lead sheet was 2.0, indicating that it transmitted, on average, 2% of incident radiation. The measured DRIP for a lead garment and one lead-alternative garment closely matched that for pure lead of 0.50 mm thickness. The DRIP for other garments was substantially higher than 0.50 mm lead (3.9–5.4), indicating they transmitted about twice as much radiation. When the DRIP was plotted versus areal density, it was clear that, of the garments tested, none were better than lead on a weight-by-weight basis. Conclusions: A method for measuring the DRIP for protective garments using scatter-mimicking primary beams was developed. There was little discernable advantage in protective value per unit weight for lead-alternative versus lead-only garments. Careful consideration must be given to the balance of protection and weight when choosing a lead-alternative protective garment with a lower specified “lead equivalence,” e.g., 0.35 mm. The DRIP has the potential to resolve this dilemma. Reporting the DRIP relative to areal density is an ideal metric for objective comparisons of protective garment performance, considering both protective value in terms of transmission of radiation and garment weight.« less

High-Efficiency, Low-Weight Power Transformer

NASA Technical Reports Server (NTRS)

Welsh, J. P.

1986-01-01

Technology for design and fabrication of radically new type of conductioncooled high-power (25 kVA) lightweight transformer having outstanding thermal and electrical characteristics. Fulfills longstanding need for conduction-cooled transformers and magnetics with low internal thermal resistances. Development techniques limited to conductive heat transfer, since other techniques such as liquid cooling, forced liquid cooling, and evaporative cooling of transformers impractical in zero-gravity space environment. Transformer uniquely designed: mechanical structure also serves as thermal paths for conduction cooling of magnetic core and windings.

Comparison of heat transfer in liquid and slush nitrogen by numerical simulation of cooling rates for French straws used for sperm cryopreservation.

PubMed

Sansinena, M; Santos, M V; Zaritzky, N; Chirife, J

2012-05-01

Slush nitrogen (SN(2)) is a mixture of solid nitrogen and liquid nitrogen, with an average temperature of -207 °C. To investigate whether plunging a French plastic straw (commonly used for sperm cryopreservation) in SN(2) substantially increases cooling rates with respect to liquid nitrogen (LN(2)), a numerical simulation of the heat conduction equation with convective boundary condition was used to predict cooling rates. Calculations performed using heat transfer coefficients in the range of film boiling confirmed the main benefit of plunging a straw in slush over LN(2) did not arise from their temperature difference (-207 vs. -196 °C), but rather from an increase in the external heat transfer coefficient. Numerical simulations using high heat transfer (h) coefficients (assumed to prevail in SN(2)) suggested that plunging in SN(2) would increase cooling rates of French straw. This increase of cooling rates was attributed to a less or null film boiling responsible for low heat transfer coefficients in liquid nitrogen when the straw is placed in the solid-liquid mixture or slush. In addition, predicted cooling rates of French straws in SN(2) tended to level-off for high h values, suggesting heat transfer was dictated by heat conduction within the liquid filled plastic straw. Copyright © 2012 Elsevier Inc. All rights reserved.

Heat-driven liquid metal cooling device for the thermal management of a computer chip

NASA Astrophysics Data System (ADS)

Ma, Kun-Quan; Liu, Jing

2007-08-01

The tremendous heat generated in a computer chip or very large scale integrated circuit raises many challenging issues to be solved. Recently, liquid metal with a low melting point was established as the most conductive coolant for efficiently cooling the computer chip. Here, by making full use of the double merits of the liquid metal, i.e. superior heat transfer performance and electromagnetically drivable ability, we demonstrate for the first time the liquid-cooling concept for the thermal management of a computer chip using waste heat to power the thermoelectric generator (TEG) and thus the flow of the liquid metal. Such a device consumes no external net energy, which warrants it a self-supporting and completely silent liquid-cooling module. Experiments on devices driven by one or two stage TEGs indicate that a dramatic temperature drop on the simulating chip has been realized without the aid of any fans. The higher the heat load, the larger will be the temperature decrease caused by the cooling device. Further, the two TEGs will generate a larger current if a copper plate is sandwiched between them to enhance heat dissipation there. This new method is expected to be significant in future thermal management of a desk or notebook computer, where both efficient cooling and extremely low energy consumption are of major concern.

Information technology equipment cooling method

DOEpatents

Schultz, Mark D.

2015-10-20

According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools air utilized by the rack of information technology equipment to cool the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat generated by the rack of information technology equipment.

To cool, but not too cool: that is the question--immersion cooling for hyperthermia.

PubMed

Taylor, Nigel A S; Caldwell, Joanne N; Van den Heuvel, Anne M J; Patterson, Mark J

2008-11-01

Patient cooling time can impact upon the prognosis of heat illness. Although ice-cold-water immersion will rapidly extract heat, access to ice or cold water may be limited in hot climates. Indeed, some have concerns regarding the sudden cold-water immersion of hyperthermic individuals, whereas others believe that cutaneous vasoconstriction may reduce convective heat transfer from the core. It was hypothesized that warmer immersion temperatures, which induce less powerful vasoconstriction, may still facilitate rapid cooling in hyperthermic individuals. Eight males participated in three trials and were heated to an esophageal temperature of 39.5 degrees C by exercising in the heat (36 degrees C, 50% relative humidity) while wearing a water-perfusion garment (40 degrees C). Subjects were cooled using each of the following methods: air (20-22 degrees C), cold-water immersion (14 degrees C), and temperate-water immersion (26 degrees C). The time to reach an esophageal temperature of 37.5 degrees C averaged 22.81 min (air), 2.16 min (cold), and 2.91 min (temperate). Whereas each of the between-trial comparisons was statistically significant (P < 0.05), cooling in temperate water took only marginally longer than that in cold water, and one cannot imagine that the 45-s cooling time difference would have any meaningful physiological or clinical implications. It is assumed that this rapid heat loss was due to a less powerful peripheral vasoconstrictor response, with central heat being more rapidly transported to the skin surface for dissipation. Although the core-to-water thermal gradient was much smaller with temperate-water cooling, greater skin and deeper tissue blood flows would support a superior convective heat delivery. Thus, a sustained physiological mechanism (blood flow) appears to have countered a less powerful thermal gradient, resulting in clinically insignificant differences in heat extraction between the cold and temperate cooling trials.

Liquid cooling of aircraft engines

NASA Technical Reports Server (NTRS)

Weidinger, Hanns

1931-01-01

This report presents a method for solving the problem of liquid cooling at high temperatures, which is an intermediate method between water and air cooling, by experiments on a test-stand and on an airplane. A utilizable cooling medium was found in ethylene glycol, which has only one disadvantage, namely, that of combustibility. The danger, however is very slight. It has one decided advantage, that it simultaneously serves as protection against freezing.

Quick connect coupling

NASA Technical Reports Server (NTRS)

Lomax, Curtis (Inventor); Webbon, Bruce (Inventor)

1995-01-01

A cooling apparatus includes a container filled with a quantity of coolant fluid initially cooled to a solid phase, a cooling loop disposed between a heat load and the container, a pump for circulating a quantity of the same type of coolant fluid in a liquid phase through the cooling loop, and a pair of couplings for communicating the liquid phase coolant fluid into the container in a direct interface with the solid phase coolant fluid.

30 CFR 250.248 - What solid and liquid wastes and discharges information and cooling water intake information must...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What solid and liquid wastes and discharges...) § 250.248 What solid and liquid wastes and discharges information and cooling water intake information must accompany the DPP or DOCD? The following solid and liquid wastes and discharges information and...

Critical Current Test of Liquid Hydrogen Cooled HTC Superconductors under External Magnetic Field

NASA Astrophysics Data System (ADS)

Shirai, Yasuyuki; Shiotsu, Masahiro; Tatsumoto, Hideki; Kobayashi, Hiroaki; Naruo, Yoshihiro; Nonaka, Satoshi; Inatani, Yoshifumi

High-Tc (HTC) superconductors including MgB2 will show excellent properties under temperature of Liquid Hydrogen (LH2:20K), which has large latent heat and low viscosity coefficient. In order to design and fabricate the LH2 cooled superconducting energy devices, we must clear the cooling property of LH2 for superconductors, the cooling system and safety design of LH2 cooled superconducting devices and electro-magnetic property evaluation of superconductors (BSCCO, REBCO and MgB2) and their magnets cooled by LH2. As the first step of the study, an experimental setup which can be used for investigating heat transfer characteristics of LH2 in a pool and also in forced flow (circulation loop with a pump), and also for evaluation of electro-magnetic properties of LH2 cooled superconductors under external magnetic field (up to 7 T). In this paper, we will show a short sketch of the experimental set-up, practical experiences in safety operation of liquid hydrogen cooling system and example test results of critical current evaluation of HTC superconductors cooled by LH2.

Degradation of fluorescent high-visibility colors used in safety garments for the Australian railway industry.

PubMed

Vijayan, Arun; Islam, Saniyat; Jones, Michael; Padhye, Rajiv; Arnold, Lyndon

2016-02-01

This study investigated the compliance of four fluorescent orange high-visibility garment substrates that are predominantly used in the Australian railway industry. While Special Purpose Orange (SPO), a shade of the Fluorescent orange (Fl-orange) is recommended by most Australian states as the high-visibility background color of a safety garment, there appear to be variations in the background color of clothing used by line-workers and rail contractors. The color of the garment was assessed for compliance with the Australian Standard AS/NZS 1906.2.2010 for high-visibility materials for safety garments. The results were also compared with ANSI Z535.2011 and BS EN ISO 20471.2013 Standards. Photometric and colorimetric assessments of the background color of the garment substrates were performed using a spectrophotometer and were evaluated for compliance with the Standards after washing and exposure to UV. The spectrophotometry measurements showed that Fl-orange background color for all samples except one complied with the AS/NZS 1906.2 Standard for daytime high-visibility garments after 20 washes but failed to comply after exposure to UV. It was also found that the chromaticity coordinates of the corners of the Fl-orange color space, specified in the AS/NZS 1906.4.2010 Standard are much wider and yellower when compared with the ANSI Z535.1.2011 and BS EN ISO 20471.2013 Standards. The sample that failed to comply with the Australian and American Standards however complied with the ISO Standard. Irrespective of the Standard used, the research has shown the degrading effect of washing and light exposure and raises the questions as to how regularly, and under what conditions high-visibility garments need to be replaced. These findings will provide information for safety garment manufacturers about the characteristics and performance of high-visibility safety garments which make them conspicuous during daytime use. This research recommends that colors for railway workers should be chosen based on the conspicuity, commercial viability, reproducibility and durability rather than simply adopting standards from other industry domains or other countries. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

Tolerence for work-induced heat stress in men wearing liquidcooled garments

NASA Technical Reports Server (NTRS)

Blockley, W. V.; Roth, H. P.

1971-01-01

An investigation of the heat tolerance in men unable to dispose of metabolic heat as fast as it is produced within the body is discussed. Examinations were made of (a) the effect of work rate (metabolic rate) on tolerance time when body heat storage rate is a fixed quantity, and (b) tolerance time as a function of metabolic rate when heat loss is terminated after a thermal quasi-equilibrium was attained under comfortable conditions of heat transfer. The nature of the physiological mechanisms involved in such heat stress situations, and the possibility of using prediction techniques to establish standard procedures in emergencies involving cooling system failures are also discussed.

A comprehensive approach to evaluating and classifying sun-protective clothing.

PubMed

Downs, N J; Harrison, S L

2018-04-01

National standards for clothing designed to protect the wearer from the harmful effects of solar ultraviolet radiation (UVR) have been implemented in Australia/New Zealand, Europe and the U.S.A. Industry standards reflect the need to protect the skin by covering a considerable proportion of the potentially exposed body surface area (BSA) and by reducing UVR-transmission through fabric (the Ultraviolet Protection Factor; UPF). This research aimed to develop a new index for rating sun-protective clothing that incorporates the BSA coverage of the garment in addition to the UPF of the fabric. A mannequin model was fixed to an optical bench and marked with horizontal lines at 1-cm intervals. An algorithm (the Garment Protector Factor; GPF) was developed based on the number of lines visible on the clothed vs. unclothed mannequin and the UPF of the garment textile. This data was collected in 2015/16 and analysed in 2016. The GPF weights fabric UPF by BSA coverage above the minimum required by international sun-protective clothing standards for upper-body, lower-body and full-body garments. The GPF increases with BSA coverage of the garment and fabric UPF. Three nominal categories are proposed for the GPF: 0 ≤ GPF < 3 for garments that 'meet' minimum standards; 3 ≤ GPF < 6 for garments providing 'good' sun protection; and GPF ≥ 6 indicating 'excellent' protection. Adoption of the proposed rating scheme should encourage manufacturers to design sun-protective garments that exceed the minimum standard for BSA coverage, with positive implications for skin cancer prevention, consumer education and sun-protection awareness. © 2017 British Association of Dermatologists.

Space Flight Orthostatic Intolerance Protection

NASA Technical Reports Server (NTRS)

Luty, Wei

2009-01-01

This paper summarizes investigations conducted on different orthostatic intolerance protection garments. This paper emphasizes on the engineering and operational aspects of the project. The current Shuttle pneumatic Anti-G Suit or AGS at 25 mmHg (0.5 psi) and customized medical mechanical compressive garments (20-30 mmHg) were tested on human subjects. The test process is presented. The preliminary results conclude that mechanical compressive garments can ameliorate orthostatic hypotension in hypovolemic subjects. A mechanical compressive garment is light, small and works without external pressure gas source; however the current garment design does not provide an adjustment to compensate for the loss of mass and size in the lower torso during long term space missions. It is also difficult to don. Compression garments that do not include an abdominal component are less effective countermeasures than garments which do. An early investigation conducted by the Human Adaptation and Countermeasures Division at Johnson Space Center (JSC) has shown there is no significant difference between the protection function of the AGS (at 77 mmHg or 1.5 psi) and the Russian anti-g suit, Kentavr (at 25 mmHg or 0.5 psi). Although both garments successfully countered hypovolemia-induced orthostatic intolerance, the Kentavr provided protection by using lower levels of compression pressure. This more recent study with a lower AGS pressure shows that pressures at 20-30 mmHg is acceptable but protection function is not as effective as higher pressure. In addition, a questionnaire survey with flight crewmembers who used both AGS and Kentavr during different missions was also performed.

LIQUID METAL REACTOR COOLING SYSTEMS

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

Aberdam, M.; Gros, G.

1965-02-01

This report is part of a series of bibliographies. The specific purpose of this report is to describe the various elements of the cooling systems in the principal liquid-metal-cooled reactors now operating, being contsructed, or in the design stage. The information given is drawn from reports or publicatios received during or before September 1964.

Investigation of Jet Impingement Cooling Using High Prandtl Number Fluids and Ammonia for Military Applications

DTIC Science & Technology

2004-03-01

interesting application of liquid jets impinging over a surface is for the cooling of microelectronics. Wadsworth and Mudawar [29] performed an...and I. Mudawar , Cooling of a Multiple Electronic Module by Means of Confined Two-Dimensional Jets of Dielectric Liquid, Journal of Heat Transfer, vol

Mount makes liquid nitrogen-cooled gamma ray detector portable

NASA Technical Reports Server (NTRS)

Fessler, T. E.

1966-01-01

Liquid nitrogen-cooled gamma ray detector system is made portable by attaching the detector to a fixture which provides a good thermal conductive path between the detector and the liquid nitrogen in a dewar flask and a low heat leak path between the detector and the external environment.

77 FR 3731 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam and Taiwan: Initiation of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-25

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-812, A-583-849] Steel Wire...'') petition concerning imports of steel wire garment hangers from Vietnam and Taiwan filed in proper form on..., as amended (the ``Act''), Petitioners allege that imports of steel wire garment hangers from Vietnam...

76 FR 14918 - Steel Wire Garment Hangers From the People's Republic of China: Partial Rescission of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers From the People's Republic of China: Partial Rescission of Antidumping Duty Administrative Review... administrative review of the antidumping duty order on steel wire garment hangers from the People's Republic of...

77 FR 28356 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam and Taiwan: Postponement of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-14

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-812, A-583-849] Steel Wire... investigations of steel wire garment hangers from the Socialist Republic of Vietnam (``Vietnam'') and Taiwan.\\1...\\ See Steel Wire Garment Hangers From the Socialist Republic of Vietnam and Taiwan: Initiation of...

77 FR 806 - Steel Wire Garment Hangers From Taiwan and Vietnam; Institution of Antidumping and Countervailing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-06

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-487 and 731-TA-1197-1198 (Preliminary)] Steel Wire Garment Hangers From Taiwan and Vietnam; Institution of Antidumping and Countervailing Duty... Vietnam of steel wire garment hangers, provided for in subheading 7326.20 of the Harmonized Tariff...

Algorithmic cooling in liquid-state nuclear magnetic resonance

NASA Astrophysics Data System (ADS)

Atia, Yosi; Elias, Yuval; Mor, Tal; Weinstein, Yossi

2016-01-01

Algorithmic cooling is a method that employs thermalization to increase qubit purification level; namely, it reduces the qubit system's entropy. We utilized gradient ascent pulse engineering, an optimal control algorithm, to implement algorithmic cooling in liquid-state nuclear magnetic resonance. Various cooling algorithms were applied onto the three qubits of C132-trichloroethylene, cooling the system beyond Shannon's entropy bound in several different ways. In particular, in one experiment a carbon qubit was cooled by a factor of 4.61. This work is a step towards potentially integrating tools of NMR quantum computing into in vivo magnetic-resonance spectroscopy.

An ergonomic garment design for elderly Turkish men.

PubMed

Civitci, S Sule

2004-05-01

This paper presents an ergonomic garment design for elderly Turkish men. The purpose of this study was to determine elderly men's demands, needs and problems in regard to clothing and to design an ergonomic garment in the light of this knowledge. The sample consisted of 120 elderly men living in Ankara, the capital city of Turkey, and its province. A questionnaire was prepared and given to these people in order to determine their clothing demands and needs. It was established that most of our subjects need functional garments. An ergonomic garment has been designed using the obtained data. It was found that the design of clothing for the elderly requires attention to bodily changes from aging in order to facilitate and raise the quality of life. Specific suggestions are made to elderly people and to the ready-to-wear sector.

21 CFR 878.4350 - Cryosurgical unit and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... and accessories. (a) Identification—(1) Cryosurgical unit with a liquid nitrogen cooled cryoprobe and accessories. A cryosurgical unit with a liquid nitrogen cooled cryoprobe and accessories is a device intended...

The seasonal performance of a liquid-desiccant air conditioner

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

Lowenstein, A.; Novosel, D.

1995-08-01

Prior reports on liquid-desiccant systems have focused on their steady-state operation at ARI design conditions. By studying their performance during an entire cooling season, the computer modeling presented here shows that liquid-desiccant systems can have a very high seasonal coefficient of performance (COP). For a liquid-desiccant system that uses a double-effect boiler, COPs ranging from 1.44 in a humid location (Houston) to 2.24 in a dry location (Phoenix) are achieved by fully exploiting indirect evaporative cooling and providing only the minimum latent cooling needed to meet the loads on the building. This minimizes the amount of water absorbed by themore » desiccant and, hence, the amount of thermal energy needed to regenerate it. In applications where latent loads are very high, such as processing the high volumes of ventilation air required to maintain good indoor air quality, the liquid-desiccant air conditioner again has an advantage over vapor-compression equipment. In this study, a liquid-desiccant system is modeled that cools and dehumidifies only the ventilation air of an office building in Atlanta. Although processing an airstream that is only 25% of the total air delivered to the building, the liquid-desiccant system is able to meet 52% of the building`s seasonal cooling requirements and reduce the building`s peak electrical demand by about 47%.« less

Apparatus for the liquefaction of natural gas and methods relating to same

DOEpatents

Turner, Terry D [Ammon, ID; Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID

2009-09-22

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates a vapor from the liquid natural gas. A portion of the liquid gas is used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line or recirculation within the system for further processing.

Apparatus for the liquefaction of a gas and methods relating to same

DOEpatents

Turner, Terry D [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID

2009-12-29

Apparatuses and methods are provided for producing liquefied gas, such as liquefied natural gas. In one embodiment, a liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream may be sequentially pass through a compressor and an expander. The process stream may also pass through a compressor. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. A portion of the liquid gas may be used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line.

Early cessation of pressure garment therapy results in scar contraction and thickening

PubMed Central

DeBruler, Danielle M.; Zbinden, Jacob C.; Baumann, Molly E.; Blackstone, Britani N.; Malara, Megan M.; Bailey, J. Kevin

2018-01-01

Pressure garment therapy is often prescribed to improve scar properties following full-thickness burn injuries. Pressure garment therapy is generally recommended for long periods of time following injury (1–2 years), though it is plagued by extremely low patient compliance. The goal of this study was to examine the effects of early cessation of pressure garment therapy on scar properties. Full-thickness burn injuries were created along the dorsum of red Duroc pigs. The burn eschar was excised and wound sites autografted with split-thickness skin. Scars were treated with pressure garments within 1 week of injury and pressure was maintained for either 29 weeks (continuous pressure) or for 17 weeks followed by cessation of pressure for an additional 12 weeks (pressure released); scars receiving no treatment served as controls. Scars that underwent pressure garment therapy were significantly smoother and less contracted with decreased scar height compared to control scars at 17 weeks. These benefits were maintained in the continuous pressure group until week 29. In the pressure released group, grafts significantly contracted and became more raised, harder and rougher after the therapy was discontinued. Pressure cessation also resulted in large changes in collagen fiber orientation and increases in collagen fiber thickness. The results suggest that pressure garment therapy effectively improves scar properties following severe burn injury; however, early cessation of the therapy results in substantial loss of these improvements. PMID:29897933

Early cessation of pressure garment therapy results in scar contraction and thickening.

PubMed

DeBruler, Danielle M; Zbinden, Jacob C; Baumann, Molly E; Blackstone, Britani N; Malara, Megan M; Bailey, J Kevin; Supp, Dorothy M; Powell, Heather M

2018-01-01

Pressure garment therapy is often prescribed to improve scar properties following full-thickness burn injuries. Pressure garment therapy is generally recommended for long periods of time following injury (1-2 years), though it is plagued by extremely low patient compliance. The goal of this study was to examine the effects of early cessation of pressure garment therapy on scar properties. Full-thickness burn injuries were created along the dorsum of red Duroc pigs. The burn eschar was excised and wound sites autografted with split-thickness skin. Scars were treated with pressure garments within 1 week of injury and pressure was maintained for either 29 weeks (continuous pressure) or for 17 weeks followed by cessation of pressure for an additional 12 weeks (pressure released); scars receiving no treatment served as controls. Scars that underwent pressure garment therapy were significantly smoother and less contracted with decreased scar height compared to control scars at 17 weeks. These benefits were maintained in the continuous pressure group until week 29. In the pressure released group, grafts significantly contracted and became more raised, harder and rougher after the therapy was discontinued. Pressure cessation also resulted in large changes in collagen fiber orientation and increases in collagen fiber thickness. The results suggest that pressure garment therapy effectively improves scar properties following severe burn injury; however, early cessation of the therapy results in substantial loss of these improvements.

Physicochemical processes in embryonic plant tissue during the transition to the state of cold anabiosis and storage at liquid nitrogen temperature

NASA Astrophysics Data System (ADS)

Khodko, A. T.; Lysak, Yu. S.

2017-10-01

Critical opalescence phenomenon was observed in the cytoplasm of garlic embryonic tissue—meristem—upon cooling in liquid nitrogen vapor, indicating liquid-liquid phase transition in the system. It was established that cells of the meristem tissue survive the cooling-thawing cycle. We suggest that the transition of meristem tissue to the state of anabiosis is mainly due to a drastic slowing of the diffusion in the cytoplasm caused by the passage of the solution through the critical point, followed by the formation of a dispersed system—a highly concentrated emulsion—as a result of a liquid-liquid phase transition. This macrophase separation is characteristic of polymer-solvent systems. We established the regime of cooling down to liquid nitrogen temperature and subsequent thawing in the cryopreservation cycle for the biological object under study, which ensures the preservation of tissue viability.

Lumped Multi-Bubble Analysis of Injection Cooling System for Storage of Cryogenic Liquids

NASA Astrophysics Data System (ADS)

Saha, Pritam; Sandilya, Pavitra

2017-12-01

Storage of cryogenic liquids is a critical issue in many cryogenic applications. Subcooling of the liquid by bubbling a gas has been suggested to extend the storage period by reducing the boil-off loss. Liquid evaporation into the gas may cause liquid subcooling by extracting the latent heat of vaporization from the liquid. The present study aims at studying the factors affecting the liquid subcooling during gas injection. A lumped parameter model is presented to capture the effects of bubble dynamics (coalescence, breakup, deformation etc.) on the heat and mass transport between the gas and the liquid. The liquid subcooling has been estimated as a function of the key operating variables such as gas flow rate and gas injection temperature. Numerical results have been found to predict the change in the liquid temperature drop reasonably well when compared with the previously reported experimental results. This modelling approach can therefore be used in gauging the significance of various process variables on the liquid subcooling by injection cooling, as well as in designing and rating an injection cooling system.

76 FR 1134 - Steel Wire Garment Hangers From the People's Republic of China: Extension of Time Limit for Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-07

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-918] Steel Wire Garment Hangers From the People's Republic of China: Extension of Time Limit for Final Results of the Antidumping Duty...'') published the preliminary results of this administrative review. See Steel Wire Garment Hangers From the...

Liquid rocket engine self-cooled combustion chambers

NASA Technical Reports Server (NTRS)

1977-01-01

Self-cooled combustion chambers are chambers in which the chamber wall temperature is controlled by methods other than fluid flow within the chamber wall supplied from an external source. In such chambers, adiabatic wall temperature may be controlled by use of upstream fluid components such as the injector or a film-coolant ring, or by internal flow of self-contained materials; e.g. pyrolysis gas flow in charring ablators, and the flow of infiltrated liquid metals in porous matrices. Five types of self-cooled chambers are considered in this monograph. The name identifying the chamber is indicative of the method (mechanism) by which the chamber is cooled, as follows: ablative; radiation cooled; internally regenerative (Interegen); heat sink; adiabatic wall. Except for the Interegen and heat sink concepts, each chamber type is discussed separately. A separate and final section of the monograph deals with heat transfer to the chamber wall and treats Stanton number evaluation, film cooling, and film-coolant injection techniques, since these subjects are common to all chamber types. Techniques for analysis of gas film cooling and liquid film cooling are presented.

Cooling-capacity characteristics of Helium-4 JT cryocoolers

NASA Astrophysics Data System (ADS)

Wang, Y. L.; Liu, D. L.; Gan, Z. H.; Guo, Y. X.; Shen, Y. W.; Chen, S. F.

2017-12-01

Cooling capacity of a Helium-4 JT cryocooler may be achieved at a temperature higher than liquid helium temperature. The latent cooling capacity, which should be obtained at liquid helium temperature, is defined as a special part of cooling capacity. With the thermodynamic analysis on steady working conditions of a Helium-4 JT cryocooler, its cooling capacity and temperature characteristics are presented systematically. The effects of precooling temperature and high pressure on the cooling capacity and latent cooling capacity are illustrated. Furthermore, the JT cryocoolers using hydrogen and neon as the working fluids are also discussed. It is shown that helium JT cryocooler has a special cooling capacity characteristic which does not exist in JT cryocoolers using other pure working fluids.

Gradient Compression Stockings may Prevent Recovery after Bed Rest Deconditioning

NASA Technical Reports Server (NTRS)

Stenger, Michael B.; Lee, Stuart M.; Westby, Christian M.; Willig, Michael C.; Platts, Steven H.

2011-01-01

Introduction: Astronauts continue to wear a compression garment during and immediately after landing to prevent orthostatic intolerance (OI). We recently developed a custom-fitted, 3-piece garment that consists of thigh-high stockings with biker-style shorts that provides continuous, gradient compression: 55 mmHg at the ankle that decreases to approximately 20 mmHg at the top of the leg and 15 mmHg over the abdomen. This garment has been shown to be effective in preventing symptoms of OI during a short stand test after Space Shuttle missions, but symptoms may persist for several days after a long-duration mission in some astronauts. The purpose of this study was to confirm the effectiveness of wearing these elastic, gradient compression garments during orthostatic testing after 2 weeks of 6 degree head-down tilt bed rest as a model of spaceflight and to determine whether they would impact recovery after bed rest. Methods: Eight (5 treatment, 3 control) of 16 subjects have completed this study to-date. All subjects wore the 3-piece garment from waking until tilt testing (3 h) as a simulation of the timeline for astronauts on landing day (BR+0). Control subjects removed the garment after the tilt test. Treatment subjects wore the garment for the remainder of the day and wore lower compression thigh-high only garments on the day after bed rest (BR+1). Blood pressure, heart rate, and stroke volume responses to a 15-min 80 degree head-up tilt test were determined before 2 weeks of 6 degree head-down tilt, and on BR+0 and BR+1. Plasma volume (PV) was measured before each of these test sessions. Data are mean SE. Results: Compression garments prevented signs of OI on BR+0; all subjects in both groups completed the full 15-min test. Heart rate responses to tilt were lower on BR+0 than all other test days. Control subjects demonstrated a marginal PV decrease after bed rest, but showed typical recovery the day after bed rest (BR+0: 2.32 plus or minus 0.15 L to BR+1: 2.79 plus or minus 0.15 L). Treatment subjects did not recover PV the day after bed rest (BR+0: 2.61 plus or minus 0.23 L to BR+1: 2.61 plus or minus 0.23 L). Conclusion: Abdomen-high compression garments, which are effective in preventing post-bed rest orthostatic intolerance, may slow recovery of PV. Modified garments with reduced compression may be necessary to prevent prolonging recovery.

Pressure garment therapy alone and in combination with silicone for the prevention of hypertrophic scarring: randomized controlled trial with intraindividual comparison.

PubMed

Steinstraesser, Lars; Flak, Ewa; Witte, Bernd; Ring, Andrej; Tilkorn, Daniel; Hauser, Jörg; Langer, Stefan; Steinau, Hans-Ulrich; Al-Benna, Sammy

2011-10-01

Published trials evaluating pressure garment and/or silicone therapy as a treatment for hypertrophic burn scarring are of poor quality and highly susceptible to bias. The authors' aim was to compare the efficacy of pressure garment therapy alone and in combination with silicone gel sheet or spray therapy for the prevention of hypertrophic scarring. The authors conducted an open, single-center, randomized controlled study with intraindividual comparison of study preparations and control to standard treatment. Forty-three consecutive patients with two comparable areas of split-thickness graft burn wounds were recruited into the study, and 38 patients were followed up for 18 months. All patients received compression garments and were randomized to one of two treatment groups: (1) self-drying silicone spray and compression versus compression alone and (2) silicone sheeting and compression versus compression alone. Clinical assessment, measurement of scar redness, height, and photographic documentation of each treated area were performed at different visits over an 18-month follow-up period. Significance was tested using repeated-measures analyses and Wilcoxon paired-sample signed rank tests. Use of pressure garment therapy alone produced results equivalent to those of combined silicone and pressure garment therapy in the prevention of hypertrophic scars. The efficacy of silicone spray therapy was comparable to that of silicone gel sheet therapy in the prevention of hypertrophic scars. Patients treated with silicone spray had fewer side effects when compared with the silicone sheet group. Multimodal therapy with silicone and pressure garment therapy failed to prevent hypertrophic scars beyond that observed with pressure garment therapy alone. Therapeutic, II.

The effects of compression garments on intermittent exercise performance and recovery on consecutive days.

PubMed

Duffield, Rob; Edge, Johann; Merrells, Robert; Hawke, Emma; Barnes, Matt; Simcock, David; Gill, Nicholas

2008-12-01

The aim of this study was to determine whether compression garments improve intermittent-sprint performance and aid performance or self-reported recovery from high-intensity efforts on consecutive days. Following familiarization, 14 male rugby players performed two randomized testing conditions (with or without garments) involving consecutive days of a simulated team sport exercise protocol, separated by 24 h of recovery within each condition and 2 weeks between conditions. Each day involved an 80-min high-intensity exercise circuit, with exercise performance determined by repeated 20-m sprints and peak power on a cart dynamometer (single-man scrum machine). Measures of nude mass, heart rate, skin and tympanic temperature, and blood lactate (La-) were recorded throughout each day; also, creatine kinase (CK) and muscle soreness were recorded each day and 48 h following exercise. No differences (P=.20 to 0.40) were present between conditions on either day of the exercise protocol for repeated 20-m sprint efforts or peak power on a cart dynamometer. Heart rate, tympanic temperature, and body mass did not significantly differ between conditions; however, skin temperature was higher under the compression garments. Although no differences (P=.50) in La- or CK were present, participants felt reduced levels of perceived muscle soreness in the ensuing 48 h postexercise when wearing the garments (2.5+/-1.7 vs 3.5+/-2.1 for garment and control; P=.01). The use of compression garments did not improve or hamper simulated team-sport activity on consecutive days. Despite benefits of reduced self-reported muscle soreness when wearing garments during and following exercise each day, no improvements in performance or recovery were apparent.

Vitrification and levitation of a liquid droplet on liquid nitrogen.

PubMed

Song, Young S; Adler, Douglas; Xu, Feng; Kayaalp, Emre; Nureddin, Aida; Anchan, Raymond M; Maas, Richard L; Demirci, Utkan

2010-03-09

The vitrification of a liquid occurs when ice crystal formation is prevented in the cryogenic environment through ultrarapid cooling. In general, vitrification entails a large temperature difference between the liquid and its surrounding medium. In our droplet vitrification experiments, we observed that such vitrification events are accompanied by a Leidenfrost phenomenon, which impedes the heat transfer to cool the liquid, when the liquid droplet comes into direct contact with liquid nitrogen. This is distinct from the more generally observed Leidenfrost phenomenon that occurs when a liquid droplet is self-vaporized on a hot plate. In the case of rapid cooling, the phase transition from liquid to vitrified solid (i.e., vitrification) and the levitation of droplets on liquid nitrogen (i.e., Leidenfrost phenomenon) take place simultaneously. Here, we investigate these two simultaneous physical events by using a theoretical model containing three dimensionless parameters (i.e., Stefan, Biot, and Fourier numbers). We explain theoretically and observe experimentally a threshold droplet radius during the vitrification of a cryoprotectant droplet in the presence of the Leidenfrost effect.

Vitrification and levitation of a liquid droplet on liquid nitrogen

PubMed Central

Song, Young S.; Adler, Douglas; Xu, Feng; Kayaalp, Emre; Nureddin, Aida; Anchan, Raymond M.; Maas, Richard L.; Demirci, Utkan

2010-01-01

The vitrification of a liquid occurs when ice crystal formation is prevented in the cryogenic environment through ultrarapid cooling. In general, vitrification entails a large temperature difference between the liquid and its surrounding medium. In our droplet vitrification experiments, we observed that such vitrification events are accompanied by a Leidenfrost phenomenon, which impedes the heat transfer to cool the liquid, when the liquid droplet comes into direct contact with liquid nitrogen. This is distinct from the more generally observed Leidenfrost phenomenon that occurs when a liquid droplet is self-vaporized on a hot plate. In the case of rapid cooling, the phase transition from liquid to vitrified solid (i.e., vitrification) and the levitation of droplets on liquid nitrogen (i.e., Leidenfrost phenomenon) take place simultaneously. Here, we investigate these two simultaneous physical events by using a theoretical model containing three dimensionless parameters (i.e., Stefan, Biot, and Fourier numbers). We explain theoretically and observe experimentally a threshold droplet radius during the vitrification of a cryoprotectant droplet in the presence of the Leidenfrost effect. PMID:20176969

16 CFR 1120.3 - Products deemed to be substantial product hazards.

Code of Federal Regulations, 2014 CFR

2014-01-01

... equivalent to sizes 2T to 16: (i) Garments in girls' size Large (L) and boys' size Large (L) are equivalent to girls' or boys' size 12, respectively. Garments in girls' and boys' sizes smaller than Large (L... range of 2T to 12. (ii) Garments in girls' size Extra-Large (XL) and boys' size Extra-Large (XL) are...

16 CFR § 1120.3 - Products deemed to be substantial product hazards.

Code of Federal Regulations, 2013 CFR

2013-01-01

... equivalent to sizes 2T to 16: (i) Garments in girls' size Large (L) and boys' size Large (L) are equivalent to girls' or boys' size 12, respectively. Garments in girls' and boys' sizes smaller than Large (L... range of 2T to 12. (ii) Garments in girls' size Extra-Large (XL) and boys' size Extra-Large (XL) are...

16 CFR 1120.3 - Products deemed to be substantial product hazards.

Code of Federal Regulations, 2012 CFR

2012-01-01

... equivalent to sizes 2T to 16: (i) Garments in girls' size Large (L) and boys' size Large (L) are equivalent to girls' or boys' size 12, respectively. Garments in girls' and boys' sizes smaller than Large (L... range of 2T to 12. (ii) Garments in girls' size Extra-Large (XL) and boys' size Extra-Large (XL) are...

Garment Counting in a Textile Warehouse by Means of a Laser Imaging System

PubMed Central

Martínez-Sala, Alejandro Santos; Sánchez-Aartnoutse, Juan Carlos; Egea-López, Esteban

2013-01-01

Textile logistic warehouses are highly automated mechanized places where control points are needed to count and validate the number of garments in each batch. This paper proposes and describes a low cost and small size automated system designed to count the number of garments by processing an image of the corresponding hanger hooks generated using an array of phototransistors sensors and a linear laser beam. The generated image is processed using computer vision techniques to infer the number of garment units. The system has been tested on two logistic warehouses with a mean error in the estimated number of hangers of 0.13%. PMID:23628760

Garment counting in a textile warehouse by means of a laser imaging system.

PubMed

Martínez-Sala, Alejandro Santos; Sánchez-Aartnoutse, Juan Carlos; Egea-López, Esteban

2013-04-29

Textile logistic warehouses are highly automated mechanized places where control points are needed to count and validate the number of garments in each batch. This paper proposes and describes a low cost and small size automated system designed to count the number of garments by processing an image of the corresponding hanger hooks generated using an array of phototransistors sensors and a linear laser beam. The generated image is processed using computer vision techniques to infer the number of garment units. The system has been tested on two logistic warehouses with a mean error in the estimated number of hangers of 0.13%.

Innovative, wearable snap connector technology for improved device networking in electronic garments

NASA Astrophysics Data System (ADS)

Kostrzewski, Andrew A.; Lee, Kang S.; Gans, Eric; Winterhalter, Carole A.; Jannson, Tomasz P.

2007-04-01

This paper discusses Physical Optics Corporation's (POC) wearable snap connector technology that provides for the transfer of data and power throughout an electronic garment (e-garment). These connectors resemble a standard garment button and can be mated blindly with only one hand. Fully compatible with military clothing, their application allows for the networking of multiple electronic devices and an intuitive method for adding/removing existing components from the system. The attached flexible cabling also permits the rugged snap connectors to be fed throughout the standard webbing found in military garments permitting placement in any location within the uniform. Variations of the snap electronics/geometry allow for integration with USB 2.0 devices, RF antennas, and are capable of transferring high bandwidth data streams such as the 221 Mbps required for VGA video. With the trend towards providing military officers with numerous electronic devices (i.e., heads up displays (HMD), GPS receiver, PDA, etc), POC's snap connector technology will greatly improve cable management resulting in a less cumbersome uniform. In addition, with electronic garments gaining widespread adoption in the commercial marketplace, POC's technology is finding applications in such areas as sporting good manufacturers and video game technology.

Confounding compression: the effects of posture, sizing and garment type on measured interface pressure in sports compression clothing.

PubMed

Brophy-Williams, Ned; Driller, Matthew William; Shing, Cecilia Mary; Fell, James William; Halson, Shona Leigh; Halson, Shona Louise

2015-01-01

The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P < 0.001). Oversized tights applied significantly less pressure than manufacturer-recommended size or undersized tights (P < 0.001), yet no significant differences were apparent between different-sized leggings. Standing posture resulted in significantly higher mean pressure application than a seated posture for both tights and leggings (P < 0.001 and P = 0.002, respectively). Pressure was different across landmarks, with analyses revealing a pressure profile that was neither strictly graduated nor progressive in nature. The pressure applied by sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.

Liquid helium-cooled MOSFET preamplifier for use with astronomical bolometer

NASA Technical Reports Server (NTRS)

Goebel, J. H.

1977-01-01

A liquid helium-cooled p-channel enhancement mode MOSFET, the 3N167, is found to have sufficiently low noise for use as a preamplifier with helium-cooled bolometers that are used in infrared astronomy. Its characteristics at 300, 77, and 4.2 K are presented. It is also shown to have useful application with certain photoconductive and photovoltaic infrared detectors.

Towards High-Frequency Shape Memory Alloy Actuators Incorporating Liquid Metal Energy Circuits

NASA Astrophysics Data System (ADS)

Hartl, Darren; Mingear, Jacob; Bielefeldt, Brent; Rohmer, John; Zamarripa, Jessica; Elwany, Alaa

2017-12-01

Large shape memory alloy (SMA) actuators are currently limited to applications with low cyclic actuation frequency requirements due to their generally poor heat transfer rates. This limitation can be overcome through the use of distributed body heating methods such as induction heating or by accelerated cooling methods such as forced convection in internal cooling channels. In this work, a monolithic SMA beam actuator containing liquid gallium-indium alloy-filled channels is fabricated through additive manufacturing. These liquid metal channels enable a novel multi-physical thermal control system, allowing for increased heating and cooling rates to facilitate an increased cyclic actuation frequency. Liquid metal flowing in the channels performs the dual tasks of inductively heating the surrounding SMA material and then actively cooling the SMA via forced internal fluid convection. A coupled thermoelectric model, implemented in COMSOL, predicts a possible fivefold increase in the cyclic actuation frequency due to these increased thermal transfer rates when compared to conventional SMA forms having external heating coils and being externally cooled via forced convection. The first ever experimental prototype SMA actuator of this type is described and, even at much lower flow rates, is shown to exhibit a decrease in cooling time of 40.9%.

Thermal Analysis of the ILC Superconductin Quadrupole

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

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

2006-09-13

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

Note: control of liquid helium supply to cryopanels of Kolkata superconducting cyclotron.

PubMed

Bhattacharyya, T K; Pal, G

2015-02-01

The Kolkata superconducting cyclotron utilises liquid helium to cool the main magnet niobium-titanium (NbTi) coil and the cryopanels. Three liquid helium cooled cryopanels, placed inside the dees of the radio-frequency system, maintain the high vacuum in the acceleration region of the superconducting cyclotron. The small cryostat placed inside the cryogenic distribution manifold located at the basement of the superconducting cyclotron building supplies liquid helium in parallel branches to three cold heads, used for cooling their associated cryopanels. The level in the cryostat has to be maintained at an optimum value to ensure uninterrupted flow of liquid helium to these three cold heads. This paper describes the transfer function of the overall system, its tuning parameters, and discusses the actual control of cryostat level by using these parameters.

Boson peak in deeply cooled confined water: a possible way to explore the existence of the liquid-to-liquid transition in water.

PubMed

Wang, Zhe; Liu, Kao-Hsiang; Le, Peisi; Li, Mingda; Chiang, Wei-Shan; Leão, Juscelino B; Copley, John R D; Tyagi, Madhusudan; Podlesnyak, Andrey; Kolesnikov, Alexander I; Mou, Chung-Yuan; Chen, Sow-Hsin

2014-06-13

The boson peak in deeply cooled water confined in nanopores is studied with inelastic neutron scattering. We show that in the (P, T) plane, the locus of the emergence of the boson peak is nearly parallel to the Widom line below ∼ 1600 bar. Above 1600 bar, the situation is different and from this difference the end pressure of the Widom line is estimated. The frequency and width of the boson peak correlate with the density of water, which suggests a method to distinguish the hypothetical "low-density liquid" and "high-density liquid" phases in deeply cooled water.

Interfacial condensation induced by sub-cooled liquid jet

NASA Astrophysics Data System (ADS)

Rame, Enrique; Balasubramaniam, R.

2016-11-01

When a sub-cooled liquid jet impinges on the free surface between a liquid and its vapor, vapor will condense at a rate dependent on the sub-cooling, the jet strength and fluid properties. In 1966 and during the examination of a different type of condensation flow, Shekriladeze found an approximate result, valid at large condensation rates, that decouples the flow in the liquid phase from that of the vapor, without putting it in the context of a formal asymptotic approximation. In this talk we will develop an asymptotic approximation that contains Shekriladze's result, and extend the calculations to the case when a non-condensable gas is present in the vapor phase.

Thermal Conductivity of Ethylene Vinyl Acetate Copolymer/Carbon Nanofiller Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Lin, Y.; Sun, Y. P.

2007-01-01

To reduce weight and increase the mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As an approach to raise the thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax 260), it was compounded with three types of carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG). In addition, other nanofillers including metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum were also compounded with Elvax 260 in the melt at various loading levels. In an attempt to improve compatibility between Elvax 260 and the nanofillers, MWCNTs and EG were modified by surface coating and through noncovalent and covalent attachment of organic molecules containing alkyl groups. Ribbons of the nanocomposites were extruded to form samples in which the nanofillers were aligned in the direction of flow. Samples were also fabricated by compression molding to yield nanocomposites in which the nanofillers were randomly oriented. Mechanical properties of the aligned samples were determined by tensile testing while the degree of dispersion and alignment of nanoparticles were investigated using high-resolution scanning electron microscopy. TC measurements were performed using a laser flash (Nanoflash ) technique. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction. Additionally, tubing was also extruded from select nanocomposite compositions and the TC and mechanical flexibility measured.

Thermal Conductivity of Ethylene Vinyl Acetate Copolymer/Nanofiller Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Lin, Y.; Sun, Y. P.

2007-01-01

To reduce weight and increase the mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As an approach to raise the thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax 260), it was compounded with three types of carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG). In addition, other nanofillers including metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum were also compounded with Elvax 260 in the melt at various loading levels. In an attempt to improve compatibility between Elvax 260 and the nanofillers, MWCNTs and EG were modified by surface coating and through noncovalent and covalent attachment of organic molecules containing alkyl groups. Ribbons of the nanocomposites were extruded to form samples in which the nanofillers were aligned in the direction of flow. Samples were also fabricated by compression molding to yield nanocomposites in which the nanofillers were randomly oriented. Mechanical properties of the aligned samples were determined by tensile testing while the degree of dispersion and alignment of nanoparticles were investigated using high-resolution scanning electron microscopy. TC measurements were performed using a laser flash (Nanoflash ) technique. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction. Additionally, tubing was also extruded from select nanocomposite compositions and the TC and mechanical flexibility measured.

Thermal Conductivity of Ethylene Vinyl Acetate Copolymer/Nanofiller Blends

NASA Technical Reports Server (NTRS)

Ghose, Sayata; Watson, Kent A.; Working, Dennis C.; Connell, John W.; Smith, Joseph G., Jr.; Lin, Y.; Sun, Y. P.

2007-01-01

To reduce weight and increase the mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As an approach to raise the thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax(TM)260), it was compounded with three types of carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG). In addition, other nanofillers including metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum were also compounded with Elvax(TM) 260 in the melt at various loading levels. In an attempt to improve compatibility between Elvax 260 and the nanofillers, MWCNTs and EG were modified by surface coating and through noncovalent and covalent attachment of organic molecules containing alkyl groups. Ribbons of the nanocomposites were extruded to form samples in which the nanofillers were aligned in the direction of flow. Samples were also fabricated by compression molding to yield nanocomposites in which the nanofillers were randomly oriented. Mechanical properties of the aligned samples were determined by tensile testing while the degree of dispersion and alignment of nanoparticles were investigated using high-resolution scanning electron microscopy. TC measurements were performed using a laser flash (Nanoflash(TM)) technique. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction. Additionally, tubing was also extruded from select nanocomposite compositions and the TC and mechanical flexibility measured.

Liquid over-feeding refrigeration system and method with integrated accumulator-expander-heat exchanger

DOEpatents

Mei, Viung C.; Chen, Fang C.

1997-01-01

A refrigeration system having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle.

Liquid over-feeding refrigeration system and method with integrated accumulator-expander-heat exchanger

DOEpatents

Mei, V.C.; Chen, F.C.

1997-04-22

A refrigeration system is described having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle. 4 figs.

The Garment Industry Development Corporation: A Case Study of a Sectoral Employment Development Approach. Sectoral Employment Development Learning Project Case Studies Series.

ERIC Educational Resources Information Center

Conway, Maureen

The Garment Industry Development Corporation (GIDC) was founded in 1984 by a 3-member partnership that included the local union, industry associations, and local government. GIDC's goal was to support New York City's garment industry, which had been steadily losing jobs. GIDC exhibits the following characteristics of sectoral initiatives: it…

Homeworking: Home Office or Home Sweatshop? Report on Current Conditions of Homeworkers in Toronto's Garment Industry. NALL Working Paper.

ERIC Educational Resources Information Center

Ng, Roxana; Wong, Renita Yuk-Lin; Choi, Angela

The current conditions of home workers in the garment industry in Toronto, Canada, were examined through in-depth telephone interviews with 30 Chinese-speaking immigrant women who were employed as home workers in 1999. The paper dicusses the formal training and informal learning experiences of immigrant woman who are garment workers. A comparison…

A cryogenic tensile testing apparatus for micro-samples cooled by miniature pulse tube cryocooler

NASA Astrophysics Data System (ADS)

Chen, L. B.; Liu, S. X.; Gu, K. X.; Zhou, Y.; Wang, J. J.

2015-12-01

This paper introduces a cryogenic tensile testing apparatus for micro-samples cooled by a miniature pulse tube cryocooler. At present, tensile tests are widely applied to measure the mechanical properties of materials; most of the cryogenic tensile testing apparatus are designed for samples with standard sizes, while for non-standard size samples, especially for microsamples, the tensile testing cannot be conducted. The general approach to cool down the specimens for tensile testing is by using of liquid nitrogen or liquid helium, which is not convenient: it is difficult to keep the temperature of the specimens at an arbitrary set point precisely, besides, in some occasions, liquid nitrogen, especially liquid helium, is not easily available. To overcome these limitations, a cryogenic tensile testing apparatus cooled by a high frequency pulse tube cryocooler has been designed, built and tested. The operating temperatures of the developed tensile testing apparatus cover from 20 K to room temperature with a controlling precision of ±10 mK. The apparatus configurations, the methods of operation and some cooling performance will be described in this paper.

The development of a cryogenic over-pressure pump

NASA Astrophysics Data System (ADS)

Alvarez, M.; Cease, H.; Flaugher, B.; Flores, R.; Garcia, J.; Lathrop, A.; Ruiz, F.

2014-01-01

A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed-loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL).

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

Narumanchi, S.; Bennion, K.; DeVoto, D.

This report describes the research into advanced liquid cooling, integrated power module cooling, high temperature air cooled power electronics, two-phase cooling for power electronics, and electric motor thermal management by NREL's Power Electronics group in FY13.

Atomizer with liquid spray quenching

DOEpatents

Anderson, Iver E.; Osborne, Matthew G.; Terpstra, Robert L.

1998-04-14

Method and apparatus for making metallic powder particles wherein a metallic melt is atomized by a rotating disk or other atomizer at an atomizing location in a manner to form molten droplets moving in a direction away from said atomizing location. The atomized droplets pass through a series of thin liquid quenching sheets disposed in succession about the atomizing location with each successive quenching sheet being at an increasing distance from the atomizing location. The atomized droplets are incrementally cooled and optionally passivated as they pass through the series of liquid quenching sheets without distorting the atomized droplets from their generally spherical shape. The atomized, cooled droplets can be received in a chamber having a collection wall disposed outwardly of the series of liquid quenching sheets. A liquid quenchant can be flowed proximate the chamber wall to carry the cooled atomized droplets to a collection chamber where atomized powder particles and the liquid quenchant are separated such that the liquid quenchant can be recycled.

Atomizer with liquid spray quenching

DOEpatents

Anderson, I.E.; Osborne, M.G.; Terpstra, R.L.

1998-04-14

Method and apparatus are disclosed for making metallic powder particles wherein a metallic melt is atomized by a rotating disk or other atomizer at an atomizing location in a manner to form molten droplets moving in a direction away from said atomizing location. The atomized droplets pass through a series of thin liquid quenching sheets disposed in succession about the atomizing location with each successive quenching sheet being at an increasing distance from the atomizing location. The atomized droplets are incrementally cooled and optionally passivated as they pass through the series of liquid quenching sheets without distorting the atomized droplets from their generally spherical shape. The atomized, cooled droplets can be received in a chamber having a collection wall disposed outwardly of the series of liquid quenching sheets. A liquid quenchant can be flowed proximate the chamber wall to carry the cooled atomized droplets to a collection chamber where atomized powder particles and the liquid quenchant are separated such that the liquid quenchant can be recycled. 6 figs.

Experimental investigation of temperature rise in bone drilling with cooling: A comparison between modes of without cooling, internal gas cooling, and external liquid cooling.

PubMed

Shakouri, Ehsan; Haghighi Hassanalideh, Hossein; Gholampour, Seifollah

2018-01-01

Bone fracture occurs due to accident, aging, and disease. For the treatment of bone fractures, it is essential that the bones are kept fixed in the right place. In complex fractures, internal fixation or external methods are used to fix the fracture position. In order to immobilize the fracture position and connect the holder equipment to it, bone drilling is required. During the drilling of the bone, the required forces to chip formation could cause an increase in the temperature. If the resulting temperature increases to 47 °C, it causes thermal necrosis of the bone. Thermal necrosis decreases bone strength in the hole and, subsequently, due to incomplete immobilization of bone, fracture repair is not performed correctly. In this study, attempts have been made to compare local temperature increases in different processes of bone drilling. This comparison has been done between drilling without cooling, drilling with gas cooling, and liquid cooling on bovine femur. Drilling tests with gas coolant using direct injection of CO 2 and N 2 gases were carried out by internal coolant drill bit. The results showed that with the use of gas coolant, the elevation of temperature has limited to 6 °C and the thermal necrosis is prevented. Maximum temperature rise reached in drilling without cooling was 56 °C, using gas and liquid coolant, a maximum temperature elevation of 43 °C and 42 °C have been obtained, respectively. This resulted in decreased possibility of thermal necrosis of bone in drilling with gas and liquid cooling. However, the results showed that the values obtained with the drilling method with direct gas cooling are independent of the rotational speed of drill.

Floating loop method for cooling integrated motors and inverters using hot liquid refrigerant

DOEpatents

Hsu, John S.; Ayers, Curtis W.; Coomer, Chester; Marlino, Laura D.

2007-03-20

A method for cooling vehicle components using the vehicle air conditioning system comprising the steps of: tapping the hot liquid refrigerant of said air conditioning system, flooding a heat exchanger in the vehicle component with said hot liquid refrigerant, evaporating said hot liquid refrigerant into hot vapor refrigerant using the heat from said vehicle component, and returning said hot vapor refrigerant to the hot vapor refrigerant line in said vehicle air conditioning system.

Cotton Dust Exposure and Resulting Respiratory Disorders Among Home-Based Garment Workers.

PubMed

Silpasuwan, Pimpan; Prayomyong, Somchit; Sujitrat, Dusit; Suwan-Ampai, Plernpit

2016-03-01

Cotton dust exposures and resulting respiratory disorders among Thai home-based garment workers in Bangkok were explored. Structured interviews focused on occupational health assessments of respiratory disorders; workflow process observations, lung function screening tests, and garment dust density assessments were used to gather data. Results revealed that garment workers in this study had worked in home-based tailoring an average of 14.88 years; 88.5% reported average health status, only 2.6% currently smoked cigarettes, and 8.6% had impaired lung function. The prevalence of respiratory disorders in this occupational group was 25%. Significant respiratory tract signs and symptoms were associated with lung function capacity (odds ratio [OR] = 52.15, 95% confidence interval [CI] = [6.49, 419.60]). Long work hours and few preventive behaviors were significantly associated with respiratory disorders (OR = 2.89 and OR = 10.183, respectively). Improving working conditions at home and minimizing fabric dust exposure among garment workers are recommended. © 2015 The Author(s).

Note: Control of liquid helium supply to cryopanels of Kolkata superconducting cyclotron

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

Bhattacharyya, T. K., E-mail: tamal@vecc.gov.in; Pal, G.

2015-02-15

The Kolkata superconducting cyclotron utilises liquid helium to cool the main magnet niobium-titanium (NbTi) coil and the cryopanels. Three liquid helium cooled cryopanels, placed inside the dees of the radio-frequency system, maintain the high vacuum in the acceleration region of the superconducting cyclotron. The small cryostat placed inside the cryogenic distribution manifold located at the basement of the superconducting cyclotron building supplies liquid helium in parallel branches to three cold heads, used for cooling their associated cryopanels. The level in the cryostat has to be maintained at an optimum value to ensure uninterrupted flow of liquid helium to these threemore » cold heads. This paper describes the transfer function of the overall system, its tuning parameters, and discusses the actual control of cryostat level by using these parameters.« less

Coal liquefaction quenching process

DOEpatents

Thorogood, Robert M.; Yeh, Chung-Liang; Donath, Ernest E.

1983-01-01

There is described an improved coal liquefaction quenching process which prevents the formation of coke with a minimum reduction of thermal efficiency of the coal liquefaction process. In the process, the rapid cooling of the liquid/solid products of the coal liquefaction reaction is performed without the cooling of the associated vapor stream to thereby prevent formation of coke and the occurrence of retrograde reactions. The rapid cooling is achieved by recycling a subcooled portion of the liquid/solid mixture to the lower section of a phase separator that separates the vapor from the liquid/solid products leaving the coal reactor.

Rotating bubble membrane radiator

DOEpatents

Webb, Brent J.; Coomes, Edmund P.

1988-12-06

A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

Garment Selection for Cleanrooms and Controlled Environments for Spacecraft

DTIC Science & Technology

1991-04-01

visually undetectable, making it diffi- cult for a worker to select a treated garment. The optimal solution has been to weave a grid of synthetic coated ...make the base fabric static-dis- sipative must be selected carefully. Nylon- coated conductive yarns are readily subject to acid attack, while...Cations (+ ) which must be eliminated from garments include sodium, potassium, lithi- um, aluminum, boron , and arsenic. The standard mtwhod for

Coalition Warfare Program Tactile Situation Awareness System for Aviation Applications: System Development

DTIC Science & Technology

2014-01-01

Advancement, specifically Mr. Ed McDaniel and Mr. Dan Seifert, who managed and pushed forward the Small Business Innovative Research (SBIR) process ...achievements. TSAS is a garment containing vibrotactile stimulators (called tactors) partially covering the torso. The garment provides aircraft flight...awareness. Working in conjunction with two SBIR companies, the recent CWP TSAS effort advanced the state of tactile cueing and delivered TSAS garments

Allergic contact dermatitis associated with reactive dyes in a dark garment: a case report.

PubMed

Moreau, Linda; Goossens, An

2005-09-01

In this study, we present a case of a patient who has not been occupationally exposed to reactive dyes, but did present with a dermatitis from wearing a dark cotton garment. The patient experienced reactivation of his dermatitis when rewearing a new unwashed dark T-shirt made of 100% cotton (in fact, the patient reported that it had to be washed at least 3 times before the skin reaction disappeared). He presented positive patch tests to 6 reactive dyes from Chemotechnique textile series. The clothing could not be proved as the true cause of the dermatitis, but resolution occurred upon removal of the suspected garment. This suggests that contact allergy to the reactive dyes (he did not react to any other dyes and his garment was a natural fabric) was likely responsible. With this report, we would like to emphasize that reactive dyes, as a class, should be considered as potential allergens, both occupationally and from non-occupational exposure such as garments. If garments containing reactive dyes are not properly rinsed in the manufacturing process, we believe that excess of dye can be retained that may cause allergic contact dermatitis (ACD). As the reactive dyes and their hydrolysis products are very water-soluble, they can be easily washed off to prevent ACD.

Observing microphysical structures and hydrometeor phase in convection with ARM active sensors

NASA Astrophysics Data System (ADS)

Riihimaki, L.; Comstock, J. M.; Luke, E. P.; Thorsen, T. J.; Fu, Q.

2016-12-01

The existence and distribution of super-cooled liquid water within convective clouds impacts the microphysical processes responsible for cloud radiative and lifetime effects. Yet few observations of cloud phase are available within convection and associated stratiform anvils. Here we identify super-cooled liquid layers within convection and associated stratiform clouds using measured radar Doppler spectra from vertically pointing Ka-band cloud radar and Raman Lidar, capitalizing on the strengths of both instruments. Observations from these sensors are used to show that liquid exists in patches within the cloud, rather than in uniform layers, impacting the growth and formation of ice. While a depolarization lidar like the Raman Lidar is a trusted measurement for identifying super-cooled liquid, the lidar attenuates at an optical depth of around three, limiting its ability to probe the full cloud. The use of the radar Doppler spectra is particularly valuable for this purpose because it allows observations within optically thicker clouds. We demonstrate a new method for identifying super-cooled liquid objectively from the radar Doppler spectra using machine-learning techniques.

Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation of a New Concept in Ultra Efficient Air Conditioning

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

Kozubal, E.; Woods, J.; Burch, J.

2011-01-01

NREL has developed the novel concept of a desiccant enhanced evaporative air conditioner (DEVap) with the objective of combining the benefits of liquid desiccant and evaporative cooling technologies into an innovative 'cooling core.' Liquid desiccant technologies have extraordinary dehumidification potential, but require an efficient cooling sink. DEVap's thermodynamic potential overcomes many shortcomings of standard refrigeration-based direct expansion cooling. DEVap decouples cooling and dehumidification performance, which results in independent temperature and humidity control. The energy input is largely switched away from electricity to low-grade thermal energy that can be sourced from fuels such as natural gas, waste heat, solar, or biofuels.

First signal from a broadband cryogenic preamplifier cooled by circulating liquid nitrogen in a 7 T Fourier transform ion cyclotron resonance mass spectrometer.

PubMed

Choi, Myoung Choul; Lee, Jeong Min; Lee, Se Gyu; Choi, Sang Hwan; Choi, Yeon Suk; Lee, Kyung Jae; Kim, SeungYong; Kim, Hyun Sik; Stahl, Stefan

2012-12-18

Despite the outstanding performance of Fourier transform ion cyclotron/mass spectrometry (FTICR/MS), the complexity of the cellular proteome or natural compounds presents considerable challenges. Sensitivity is a key performance parameter of a FTICR mass spectrometer. By improving this parameter, the dynamic range of the instrument can be increased to improve the detection signal of low-abundance compounds or fragment ion peaks. In order to improve sensitivity, a cryogenic detection system was developed by the KBSI (Korean Basic Science Institute) in collaboration with Stahl-Electronics (Mettenheim, Germany). A simple, efficient liquid circulation cooling system was designed and a cryogenic preamplifier implemented inside a FTICR mass spectrometer. This cooling system circulates a cryoliquid from a Dewar to the "liquid circulation unit" through a CF flange to cool a copper block and a cryopreamplifier; the cooling medium is subsequently exhausted into the air. The cryopreamplifier can be operated over a very wide temperature range, from room temperature to low temperature environments (4.2 K). First, ion signals detected by the cryopreamplifier using a circulating liquid nitrogen cooling system were observed and showed a signal-to-noise ratio (S/N) about 130% better than that obtained at room temperature.

Film-Cooling Heat-Transfer Measurements Using Liquid Crystals

NASA Technical Reports Server (NTRS)

Hippensteele, Steven A.

1997-01-01

The following topics are discussed: (1) The Transient Liquid-Crystal Heat-Transfer Technique; (2) 2-D Film-Cooling Heat-Transfer on an AlliedSignal Vane; and (3) Effects of Tab Vortex Generators on Surface Heat Transfer. Downstream of a Jet in Crossflow.

Cryogenic filter method produces super-pure helium and helium isotopes

NASA Technical Reports Server (NTRS)

Hildebrandt, A. F.

1964-01-01

Helium is purified when cooled in a low pressure environment until it becomes superfluid. The liquid helium is then filtered through iron oxide particles. Heating, cooling and filtering processes continue until the purified liquid helium is heated to a gas.

Market study: Biological isolation garment

NASA Technical Reports Server (NTRS)

1975-01-01

The biological isolation garment was originally designed for Apollo astronauts to wear upon their return to earth from the moon to avoid the possibility of their contaminating the environment. The concept has been adapted for medical use to protect certain patients from environmental contamination and the risk of infection. The nature and size of the anticipated market are examined with certain findings and conclusions relative to clinical acceptability and potential commercial viability of the biological isolation garment.

Cleanroom Garment Silicone Contamination

NASA Technical Reports Server (NTRS)

Geer, Wayne; Lepage, Colette

2006-01-01

The slide presentation reviews actions taken at Goddard Space Flight Center (GSFC) to eliminate contamination by silicone in clean rooms. Background information includes facilities and hardware affected by silicon contamination, a discussion of the negative aspects of silicone contamination, clean room garments, and how the problem was identified at GSFC. Actions taken by the GSFC Contamination Engineering Group and lessons learned are detailed. Results include: awareness of the silicone issue in laundry, increase in infrastructure and support of the testing lab, establishment of protocols for garment verification, closer relationship established with laundry and converter, specifications for laundry services and garments were strengthened, all consumables are tested before use in clean rooms, and established procedures were used to identify and treat silicone found on face masks.

Influence of coolant injector configuration on film cooling effectiveness for gaseous and liquid film coolants

NASA Astrophysics Data System (ADS)

Shine, S. R.; Sunil Kumar, S.; Suresh, B. N.

2012-05-01

An experimental investigation is conducted to bring out the effects of coolant injector configuration on film cooling effectiveness, film cooled length and film uniformity associated with gaseous and liquid coolants. A series of measurements are performed using hot air as the core gas and gaseous nitrogen and water as the film coolants in a cylindrical test section simulating a thrust chamber. Straight and compound angle injection at two different configurations of 30°-10° and 45°-10° are investigated for the gaseous coolant. Tangential injection at 30° and compound angle injection at 30°-10° are examined for the liquid coolant. The analysis is based on measurements of the film-cooling effectiveness and film uniformity downstream of the injection location at different blowing ratios. Measured results showed that compound angle configuration leads to lower far-field effectiveness and shorter film length compared to tangential injection in the case of liquid film cooling. For similar injector configurations, effectiveness along the stream wise direction showed flat characteristics initially for the liquid coolant, while it was continuously dropping for the gaseous coolant. For liquid coolant, deviations in temperature around the circumference are very low near the injection point, but increases to higher values for regions away from the coolant injection locations. The study brings out the existance of an optimum gaseous film coolant injector configuration for which the effectiveness is maximum.

Determination of heat transfer coefficients in plastic French straws plunged in liquid nitrogen.

PubMed

Santos, M Victoria; Sansinena, M; Chirife, J; Zaritzky, N

2014-12-01

The knowledge of the thermodynamic process during the cooling of reproductive biological systems is important to assess and optimize the cryopreservation procedures. The time-temperature curve of a sample immersed in liquid nitrogen enables the calculation of cooling rates and helps to determine whether it is vitrified or undergoes phase change transition. When dealing with cryogenic liquids, the temperature difference between the solid and the sample is high enough to cause boiling of the liquid, and the sample can undergo different regimes such as film and/or nucleate pool boiling. In the present work, the surface heat transfer coefficients (h) for plastic French straws plunged in liquid nitrogen were determined using the measurement of time-temperature curves. When straws filled with ice were used the cooling curve showed an abrupt slope change which was attributed to the transition of film into nucleate pool boiling regime. The h value that fitted each stage of the cooling process was calculated using a numerical finite element program that solves the heat transfer partial differential equation under transient conditions. In the cooling process corresponding to film boiling regime, the h that best fitted experimental results was h=148.12±5.4 W/m(2) K and for nucleate-boiling h=1355±51 W/m(2) K. These values were further validated by predicting the time-temperature curve for French straws filled with a biological fluid system (bovine semen-extender) which undergoes freezing. Good agreement was obtained between the experimental and predicted temperature profiles, further confirming the accuracy of the h values previously determined for the ice-filled straw. These coefficients were corroborated using literature correlations. The determination of the boiling regimes that govern the cooling process when plunging straws in liquid nitrogen constitutes an important issue when trying to optimize cryopreservation procedures. Furthermore, this information can lead to improvements in the design of cooling devices in the cryobiology field. Copyright © 2014 Elsevier Inc. All rights reserved.

High field solenoids for muon cooling

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

Green, M.A.; Eyssa, Y.; Kenny, S.

1999-09-08

The proposed cooling system for the muon collider will consist of a 200 meter long line of alternating field straight solenoids interspersed with bent solenoids. The muons are cooled in all directions using a 400 mm long section liquid hydrogen at high field. The muons are accelerated in the forward direction by about 900 mm long, 805 MHz RF cavities in a gradient field that goes from 6 T to -6 T in about 300 mm. The high field section in the channel starts out at an induction of about 2 T in the hydrogen. As the muons proceed downmore » the cooling channel, the induction in the liquid hydrogen section increases to inductions as high as 30 T. The diameter of the liquid hydrogen section starts at 750 mm when the induction is 2 T. As the induction in the cooling section goes up, the diameter of the liquid hydrogen section decreases. When the high field induction is 30 T, the diameter of the liquid hydrogen section is about 80 mm. When the high field solenoid induction is below 8.5 T or 9T, niobium titanium coils are proposed for generating .the magnetic field. Above 8.5 T or 9 T to about 20 T, graded niobium tin and niobium titanium coils would be used at temperatures down to 1.8 K. Above 20 T, a graded bybrid magnet system is proposed, where the high field magnet section (above 20 T) is either a conventional water cooled coil section or a water cooled Bitter type coil. Two types of superconducting coils have been studied. They include; epoxy impregnated intrinsically stable coils, and cable in conduit conductor (CICC) coils with helium in the conduit.« less

Substitution of PFAS chemistry in outdoor apparel and the impact on repellency performance.

PubMed

Hill, Philippa J; Taylor, Mark; Goswami, Parikshit; Blackburn, Richard S

2017-08-01

Intensifying legislation and increased research on the toxicological and persistent nature of per- and polyfluoroalkyl substances (PFASs) have recently influenced the direction of liquid repellent chemistry use; environmental, social, and sustainability responsibilities are at the crux. Without PFAS chemistry, it is challenging to meet current textile industry liquid repellency requirements, which is a highly desirable property, particularly in outdoor apparel where the technology helps to provide the wearer with essential protection from adverse environmental conditions. Herein, complexities between required functionality, legislation and sustainability within outdoor apparel are discussed, and fundamental technical performance of commercially available long-chain (C8) PFASs, shorter-chain (C6) PFASs, and non-fluorinated repellent chemistries finishes are evaluated comparatively. Non-fluorinated finishes provided no oil repellency, and were clearly inferior in this property to PFAS-finished fabrics that demonstrated good oil-resistance. However, water repellency ratings were similar across the range of all finished fabrics tested, all demonstrating a high level of resistance to wetting, and several non-fluorinated repellent fabrics provide similar water repellency to long-chain (C8) PFAS or shorter-chain (C6) PFAS finished fabrics. The primary repellency function required in outdoor apparel is water repellency, and we would propose that the use of PFAS chemistry for such garments is over-engineering, providing oil repellency that is in excess of user requirements. Accordingly, significant environmental and toxicological benefits could be achieved by switching outdoor apparel to non-fluorinated finishes without a significant reduction in garment water-repellency performance. These conclusions are being supported by further research into the effect of laundering, abrasion and ageing of these fabrics. Copyright © 2017 Elsevier Ltd. All rights reserved.

A critical review of liquid helium temperature high frequency pulse tube cryocoolers for space applications

NASA Astrophysics Data System (ADS)

Wang, B.; Gan, Z. H.

2013-08-01

The importance of liquid helium temperature cooling technology in the aerospace field is discussed, and the results indicate that improving the efficiency of liquid helium cooling technologies, especially the liquid helium high frequency pulse tube cryocoolers, is the principal difficulty to be solved. The state of the art and recent developments of liquid helium high frequency pulse tube cryocoolers are summarized. The main scientific challenges for high frequency pulse tube cryocoolers to efficiently reach liquid helium temperatures are outlined, and the research progress addressing those challenges are reviewed. Additionally some possible solutions to the challenges are pointed out and discussed.

Pilot Field Test: Use of a Compression Garment During a Stand Test After Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Laurie, S. S.; Stenger, M. B.; Phillips, T. R.; Lee, S. M. C.; Cerisano, J.; Kofman, I.; Reschke, M.

2016-01-01

Orthostatic intolerance (OI) is a concern for astronauts returning from long-duration space flight. One countermeasure that has been used to protect against OI after short-duration bed rest and space flight is the use of lower body and abdominal compression garments. However, since the end of the Space Shuttle era we have not been able to test crewmembers during the first 24 hours after landing on Earth. NASA's Pilot Field Test provided us the opportunity to test cardiovascular responses of crewmembers wearing the Russian Kentavr compression garment during a stand test at multiple time points throughout the first 24 hours after landing. HYPOTHESIS We hypothesized that the Kentavr compression garment would prevent an increase in heart rate (HR) >15 bpm during a 3.5-min stand test. METHODS: The Pilot Field Test was conducted up to 3 times during the first 24 hours after crewmembers returned to Earth: (1) either in a tent adjacent to the Soyuz landing site in Kazakhstan (approx.1 hr) or after transportation to the Karaganda airport (approx. 4 hr); (2) during a refueling stop in Scotland (approx.12 hr); and (3) upon return to NASA Johnson Space Center (JSC) (approx.24 hr). We measured HR and arterial pressure (finger photoplethysmography) for 2 min while the crewmember was prone and throughout 3.5 min of quiet standing. Eleven crewmembers consented to participate; however, 2 felt too ill to start the test and 1 stopped 30 sec into the stand portion of the test. Of the remaining 8 crewmembers, 2 did not wear the Russian Kentavr compression garment. Because of inclement weather at the landing site, 5 crewmembers were flown by helicopter to the Karaganda airport before initial testing and received intravenous saline before completing the stand test. One of these crewmembers wore only the portion of the Russian Kentavr compression garment that covered the lower leg and thus lacked thigh and abdominal compression. All crewmembers continued wearing the Russian Kentavr compression garment during the second testing session in Scotland, but none wore it during testing at JSC. RESULTS: The mean Delta HR from the supine to standing position in the 8 crewmembers measured pre-flight or 60 days after return from long-duration space flight was 9.8 bpm. During the first few hours after landing from long-duration space flight, the mean Delta HR of the 6 crewmembers who wore the Russian Kentavr compression garment in Kazakhstan or Karaganda was +14 bpm and the change in mean arterial pressure (Delta MAP) was +0.8 mmHg, while the 2 crewmembers who did not wear the Russian Kentavr compression garment had a Delta HR of +38 bpm and a Delta MAP of +1.1 mmHg. In Scotland, 4 crewmembers wore the Russian Kentavr compression garment and had a Delta HR of +7.4 bpm while the 3 crewmembers who did not wear it had a Delta HR of +25.0 bpm. Seven crewmembers were tested upon return to JSC approx. 24 hr after landing, but none wore the Russian Kentavr compression garment and their Delta HR was 16.0 bpm. CONCLUSIONS: These are the first stand-test data to be collected from long-duration crewmembers during the first 24 hr of re-adaptation to gravity on Earth. The Delta HR measured in crewmembers who completed the stand-test while wearing Kentavr within the first approx.4 hours after returning to Earth was only slightly elevated from pre-flight Delta HR, while the few subjects who did not wear the Russian Kentavr compression garment had a much larger increase in HR in order to maintain arterial pressure throughout 3.5-min of standing. These data demonstrate the effectiveness of a compression garment in preventing large increases in HR during a 3.5 min stand test after long-duration space flight. However, the fact that three crewmembers were too ill to complete the test or was not able to complete 3.5 min of standing despite wearing the Russian Kentavr compression garment indicates that wearing a compression garment does not resolve all problems crewmembers face during the period of re-adaptation immediately after return to Earth's gravity.

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

Code of Federal Regulations, 2011 CFR

2011-10-01

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

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

Code of Federal Regulations, 2014 CFR

2014-10-01

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

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

Code of Federal Regulations, 2012 CFR

2012-10-01

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

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

Code of Federal Regulations, 2013 CFR

2013-10-01

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

Development of a Very Dense Liquid Cooled Compute Platform

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

Hughes, Phillip N.; Lipp, Robert J.

2013-12-10

The objective of this project was to design and develop a prototype very energy efficient high density compute platform with 100% pumped refrigerant liquid cooling using commodity components and high volume manufacturing techniques. Testing at SLAC has indicated that we achieved a DCIE of 0.93 against our original goal of 0.85. This number includes both cooling and power supply and was achieved employing some of the highest wattage processors available.

Cooling of Gas Turbines, IV - Calculated Temperature Distribution in the Trailing Part of a Turbine Blade Using Direct Liquid Cooling

NASA Technical Reports Server (NTRS)

Brown, W. Byron; Monroe, William R.

1947-01-01

A theoretical analysis of the temperature distribution through the trailing portion of a blade near the coolant passages of liquid cooled gas turbines was made. The analysis was applied to obtain the hot spot temperatures at the trailing edge and influence of design variables. The effective gas temperature was varied from 2000 degrees to 5000 degrees F in each investigation.

Utilizing of inner porous structure in injection moulds for application of special cooling method

NASA Astrophysics Data System (ADS)

Seidl, M.; Bobek, J.; Šafka, J.; Habr, J.; Nováková, I.; Běhálek, L.

2016-04-01

The article is focused on impact evaluation of controlled inner structure of production tools and new cooling method on regulation of thermal processes for injection moulding technology. The mould inserts with porous structure were cooled by means of liquid CO2 which is very progressive cooling method and enables very fast and intensive heat transfer among the plastic product, the production tool and cooling medium. The inserts were created using rapid prototype technology (DLSM) and they had a bi-component structure consisting of thin compact surface layer and defined porous inner structure of open cell character where liquid CO2 was flowing through. This analyse includes the evaluation of cooling efficiency for different inner structures and different time profiles for dosing of liquid CO2 into the porous structure. The thermal processes were monitored using thermocouples and IR thermal analyse of product surface and experimental device. Intensive heat removal influenced also the final structure and the shape and dimensional accuracy of the moulded parts that were made of semi-crystalline polymer. The range of final impacts of using intensive cooling method on the plastic parts was defined by DSC and dimensional analyses.

Trap seal for open circuit liquid cooled turbines

DOEpatents

Grondahl, Clayton M.; Germain, Malcolm R.

1980-01-01

An improved trap seal for open circuit liquid cooled turbines is disclosed. The trap seal of the present invention includes an annular recess formed in the supply conduit of cooling channels formed in the airfoil of the turbine buckets. A cylindrical insert is located in the annular recesses and has a plurality of axial grooves formed along the outer periphery thereof and a central recess formed in one end thereof. The axial grooves and central recess formed in the cylindrical insert cooperate with the annular recess to define a plurality of S-shaped trap seals which permit the passage of liquid coolant but prohibit passage of gaseous coolant.

Design study of steady-state 30-tesla liquid-neon-cooled magnet

NASA Technical Reports Server (NTRS)

Prok, G. M.; Brown, G. V.

1976-01-01

A design for a 30-tesla, liquid-neon-cooled magnet was reported which is capable of continuous operation. Cooled by nonboiling, forced-convection heat transfer to liquid neon flowing at 2.8 cu m/min in a closed, pressurized heat-transfer loop and structurally supported by a tapered structural ribbon, the tape-wound coils with a high-purity-aluminum conductor will produce over 30 teslas for 1 minute at 850 kilowatts. The magnet will have an inside diameter of 7.5 centimeters and an outside diameter of 54 centimeters. The minimum current density at design field will be 15.7 kA/sq cm.

Comparison of three types of full‐body compression garments on throwing and repeat‐sprint performance in cricket players

PubMed Central

Duffield, Rob; Portus, Marc

2007-01-01

Objective To compare the effects of three types of full‐body compression garments (Skins, Adidas and Under Armour) on repeat‐sprint and throwing performance in cricket players. Methods Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat‐sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre‐exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O2 saturation and O2 partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. Results No significant differences (p>0.05) were evident in repeat‐sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p<0.05) were observed by way of higher mean skin temperature, lower 24 h postexercise CK values and lower 24 h postexercise ratings of muscle soreness when wearing compression garments. Analysis between respective brands of compression garments revealed no statistical differences (p>0.05). Conclusions No benefit was noted when wearing compression garments for repeat‐sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness. PMID:17341589

Comparison of three types of full-body compression garments on throwing and repeat-sprint performance in cricket players.

PubMed

Duffield, Rob; Portus, Marc

2007-07-01

To compare the effects of three types of full-body compression garments (Skins, Adidas and Under Armour) on repeat-sprint and throwing performance in cricket players. Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat-sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre-exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O(2) saturation and O(2) partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. No significant differences (p>0.05) were evident in repeat-sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p<0.05) were observed by way of higher mean skin temperature, lower 24 h postexercise CK values and lower 24 h postexercise ratings of muscle soreness when wearing compression garments. Analysis between respective brands of compression garments revealed no statistical differences (p>0.05). No benefit was noted when wearing compression garments for repeat-sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness.

Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement

NASA Technical Reports Server (NTRS)

Lundin, Bruce T; Povolny, John H; Chelko, Louis J

1949-01-01

Data obtained from an extensive investigation of the cooling characteristics of four multicylinder, liquid-cooled engines have been analyzed and a correlation of both the cylinder-head temperatures and the coolant heat rejections with the primary engine and coolant variables was obtained. The method of correlation was previously developed by the NACA from an analysis of the cooling processes involved in a liquid-cooled-engine cylinder and is based on the theory of nonboiling, forced-convection heat transfer. The data correlated included engine power outputs from 275 to 1860 brake horsepower; coolant flows from 50 to 320 gallons per minute; coolants varying in composition from 100 percent water to 97 percent ethylene glycol and 3 percent water; and ranges of engine speed, manifold pressure, carburetor-air temperature, fuel-air ratio, exhaust-gas pressure, ignition timing, and coolant temperature. The effect on engine cooling of scale formation on the coolant passages of the engine and of boiling of the coolant under various operating conditions is also discussed.

STUDY PROGRAM FOR TURBO-COOLER FOR PRODUCING ENGINE COOLING AIR.

DTIC Science & Technology

VANES , STAGNATION POINT, DECELERATION, ACCELERATION, SUPERSONIC DIFFUSERS, TURBINE BLADES , EVAPOTRANSPIRATION, LIQUID COOLED, HEAT TRANSFER, GAS BEARINGS, SEALS...HYPERSONIC AIRCRAFT , COOLING + VENTILATING EQUIPMENT), (*GAS TURBINES , COOLING + VENTILATING EQUIPMENT), HYPERSONIC FLOW, AIR COOLED, AIRCRAFT ... ENGINES , FEASIBILITY STUDIES, PRESSURE, SUPERSONIC CHARACTERISTICS, DESIGN, HEAT EXCHANGERS, COOLING (U) AXIAL FLOW TURBINES , DUCT INLETS, INLET GUIDE

Exposure of women to trace elements through the skin by direct contact with underwear clothing.

PubMed

Nguyen, Thao; Saleh, Mahmoud A

2017-01-02

Heavy metals pose a potential danger to human health when present in textile materials. In the present study, inductive coupled plasma mass spectrometry (ICPMS) was used to determine the concentrations and the identity of extractable inorganic elements from different brands of women undergarments. A total of 120 samples consisting of 63 cottons, 44 nylons and 13 polyesters manufactured in 14 different countries having different colors were analyzed for their extractable metals contents. Elements analyzed were Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Se, Sr, Ti, V and Zn. Cotton undergarments were rich in Al, Fe and Zn, nylon undergarments had high levels of Cr, Cu and Al, while polyester fabrics contained higher levels of Ni and Fe compared to cotton or nylon. With respect to manufacturing countries, China, Egypt and India showed the highest concentrations of metals in all fabrics. With respect to the color, black garments were characteristic by high concentration of Fe, blue colors with Cu, brown garments with Fe and Cu, green garments with Cu and Fe, pink garments with Al, purple garments with Al and Cu and red garments with Cr, Zn and Al. The consumer should be made aware of the potential dangers of these metals in their clothing.

The Effects of Compression-Garment Pressure on Recovery After Strenuous Exercise.

PubMed

Hill, Jessica; Howatson, Glyn; van Someren, Ken; Gaze, David; Legg, Hayley; Lineham, Jack; Pedlar, Charles

2017-09-01

Compression garments are frequently used to facilitate recovery from strenuous exercise. To identify the effects of 2 different grades of compression garment on recovery indices after strenuous exercise. Forty-five recreationally active participants (n = 26 male and n = 19 female) completed an eccentric-exercise protocol consisting of 100 drop jumps, after which they were matched for body mass and randomly but equally assigned to a high-compression pressure (HI) group, a low-compression pressure (LOW) group, or a sham ultrasound group (SHAM). Participants in the HI and LOW groups wore the garments for 72 h postexercise; participants in the SHAM group received a single treatment of 10-min sham ultrasound. Measures of perceived muscle soreness, maximal voluntary contraction (MVC), countermovement-jump height (CMJ), creatine kinase (CK), C-reactive protein (CRP), and myoglobin (Mb) were assessed before the exercise protocol and again at 1, 24, 48, and 72 h postexercise. Data were analyzed using a repeated-measures ANOVA. Recovery of MVC and CMJ was significantly improved with the HI compression garment (P < .05). A significant time-by-treatment interaction was also observed for jump height at 24 h postexercise (P < .05). No significant differences were observed for parameters of soreness and plasma CK, CRP, and Mb. The pressures exerted by a compression garment affect recovery after exercise-induced muscle damage, with higher pressure improving recovery of muscle function.

The gendered workplaces of women garment workers in Istanbul.

PubMed

Can, Başak

2017-10-01

Drawing on 20 semi-structured interviews with women garment workers in a low-income neighbourhood of Istanbul, and observations in the ateliers where they worked, this article examines their work experiences in the gendered and sexualised work atmosphere of garment workshops. There are three interrelated levels upon which the gender-related issues emerge in women garment workers' stories. The first set of discourses portrays young female garment workers in highly sexualised terms, and the second concerns the use of kinship vocabulary and avoidance of impersonal work relationships. That is, women workers' experiences in capitalist production sites were trivialised and regulated through the sexualisation of their bodies and the deployment of kinship idioms while addressing their role at the workplace. The third level analyses women's submissive, subversive or contradictory responses to these gendered disciplinary techniques and representations, i.e. the construction of their subjectivities. These three levels point to two things: first, cultural presumptions about marriage, women's sexuality and reproductive cycles are materialised at the workplace. Second, gendered instantiations of these presumptions in a specific work environment are both informed by their familial roles (such as daughter, wife, mother, widowed) and inform their future reproductive preferences (whether they marry, have a child, get a divorce, etc.). This article shows how the ways in which women's difference is construed and acted upon in the garment industry are inseparable from women's reproductive decisions.

9 CFR 590.530 - Liquid egg cooling.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Liquid egg cooling. 590.530 Section 590.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Sanitary, Processing...

9 CFR 590.530 - Liquid egg cooling.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Liquid egg cooling. 590.530 Section 590.530 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Sanitary, Processing...

Pressure mapping and performance of the compression bandage/garment for venous leg ulcer treatment.

PubMed

Ghosh, S; Mukhopadhyay, A; Sikka, M; Nagla, K S

2008-08-01

A study has been conducted on the commercially available compression bandages as regards their performance with time. Pressure mapping of these bandages has been done using a fabricated pressure-measuring device on a mannequin leg to see the effect on pressure due to creep, fabric friction and angle of bandaging. The results show that the creep behavior, frictional behavior and the angle of bandaging have a significant effect on the pressure profile generated by the bandages during application. The regression analysis shows that the surface friction restricts the slippage in a multilayer system. Also the diameters of the limb and the amount of stretch given to the bandage during application have definite impact on the bandage pressure. In case of compression garments, washing improves the pressure generated but not to the extent of the pressure of a virgin garment. Comparing the two compression materials i.e. bandage and garment, it is found that the presence of higher percentage of elastomeric material and a highly close construction in case of garment provides better holding power and a more homogeneous pressure distribution.

Smart garments for emergency operators: the ProeTEX project.

PubMed

Curone, Davide; Secco, Emanuele Lindo; Tognetti, Alessandro; Loriga, Giannicola; Dudnik, Gabriela; Risatti, Michele; Whyte, Rhys; Bonfiglio, Annalisa; Magenes, Giovanni

2010-05-01

Financed by the European Commission, a consortium of 23 European partners, consisting of universities, research institutions, industries, and organizations operating in the field of emergency management, is developing a new generation of "smart" garments for emergency-disaster personnel. Garments integrate newly developed wearable and textile solutions, such as commercial portable sensors and devices, in order to continuously monitor risks endangering rescuers' lives. The system enables detection of health-state parameters of the users (heart rate, breathing rate, body temperature, blood oxygen saturation, position, activity, and posture) and environmental variables (external temperature, presence of toxic gases, and heat flux passing through the garments), to process data and remotely transmit useful information to the operation manager. The European-integrated project, called ProeTEX (Protection e-Textiles: Micro-Nano-Structured fiber systems for Emergency-Disaster Wear) started on February, 2006 and will end on July, 2010. During this 4.5 years period, three subsequent generations of sensorized garments are being released. This paper proposes an overview of the project and gives a description of the second-generation prototypes, delivered at the end of 2008.

Tests of Five Full-Scale Propellers in the Presence of a Radial and a Liquid-Cooled Engine Nacelle, Including Tests of Two Spinners

NASA Technical Reports Server (NTRS)

Biermann, David; Hartman, Edwin P

1938-01-01

Wind-tunnel tests are reported of five 3-blade 10-foot propellers operating in front of a radial and a liquid-cooled engine nacelle. The range of blade angles investigated extended from 15 degrees to 45 degrees. Two spinners were tested in conjunction with the liquid-cooled engine nacelle. Comparisons are made between propellers having different blade-shank shapes, blades of different thickness, and different airfoil sections. The results show that propellers operating in front of the liquid-cooled engine nacelle had higher take-off efficiencies than when operating in front of the radial engine nacelle; the peak efficiency was higher only when spinners were employed. One spinner increased the propulsive efficiency of the liquid-cooled unit 6 percent for the highest blade-angle setting investigated and less for lower blade angles. The propeller having airfoil sections extending into the hub was superior to one having round blade shanks. The thick propeller having a Clark y section had a higher take-off efficiency than the thinner one, but its maximum efficiency was possibly lower. Of the three blade sections tested, Clark y, R.A.F. 6, and NACA 2400-34, the Clark y was superior for the high-speed condition, but the R.A.F. 6 excelled for the take-off condition.

Cooling rate dependence of the glass transition at free surfaces

NASA Astrophysics Data System (ADS)

Streit-Nierobisch, S.; Gutt, C.; Paulus, M.; Tolan, M.

2008-01-01

In situ x-ray reflectivity measurements are used to determine the cooling rate dependent freezing of capillary waves on the oligomer poly(propylene glycol). Only above the glass transition temperature TG can the surface roughness σ be described by the capillary wave model for simple liquids, whereas the surface fluctuations are frozen-in at temperatures below TG . As the state of a glass forming liquid strongly depends on its thermal history, this effect occurs for fast cooling rates already at a higher temperature than for slow cooling. For the fastest cooling rates a very large shift of TG up to 240K compared to the bulk value of 196K was observed.

Design of a smart ECG garment based on conductive textile electrode and flexible printed circuit board.

PubMed

Cai, Zhipeng; Luo, Kan; Liu, Chengyu; Li, Jianqing

2017-08-09

A smart electrocardiogram (ECG) garment system was designed for continuous, non-invasive and comfortable ECG monitoring, which mainly consists of four components: Conductive textile electrode, garment, flexible printed circuit board (FPCB)-based ECG processing module and android application program. Conductive textile electrode and FPCB-based ECG processing module (6.8 g, 55 mm × 53 mm × 5 mm) are identified as two key techniques to improve the system's comfort and flexibility. Preliminary experimental results verified that the textile electrodes with circle shape, 40 mm size in diameter, and 5 mm thickness sponge are best suited for the long-term ECG monitoring application. The tests on the whole system confirmed that the designed smart garment can obtain long-term ECG recordings with high signal quality.

Smart Rehabilitation Garment for posture monitoring.

PubMed

Wang, Q; Chen, W; Timmermans, A A A; Karachristos, C; Martens, J B; Markopoulos, P

2015-08-01

Posture monitoring and correction technologies can support prevention and treatment of spinal pain or can help detect and avoid compensatory movements during the neurological rehabilitation of upper extremities, which can be very important to ensure their effectiveness. We describe the design and development of Smart Rehabilitation Garment (SRG) a wearable system designed to support posture correction. The SRG combines a number of inertial measurement units (IMUs), controlled by an Arduino processor. It provides feedback with vibration on the garment, audible alarm signals and visual instruction through a Bluetooth connected smartphone. We discuss the placement of sensing modules, the garment design, the feedback design and the integration of smart textiles and wearable electronics which aimed at achieving wearability and ease of use. We report on the system's accuracy as compared to optical tracker method.

The length and time scales of water's glass transitions

NASA Astrophysics Data System (ADS)

Limmer, David T.

2014-06-01

Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

The length and time scales of water's glass transitions.

PubMed

Limmer, David T

2014-06-07

Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

A Multi-Center Controlled Study of the Acute and Chronic Effects of Cooling Therapy for MS

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Schwid, Steven W.; Cutter, Gary; Murray, Ronald; Bowen, James; Pellegrino, Richard; Guisado, Raul; Webbon, Bruce W.; DeVincenzi, Donald (Technical Monitor)

2000-01-01

To determine the acute and chronic effects of cooling therapy on patients with MS using objective functional performance measures and self-assessed measures of fatigue. Cooling demyelinated nerves can reduce conduction block, potentially improving symptoms of MS. Significant acute and chronic effects of cooling have not been demonstrated in a multi-center, controlled, blinded study using objective measures of neurologic function. Patients (N=84) with definite MS, mild to moderate disability (EDSS less than 6.0), and self-reported heat sensitivity were enrolled at 5 study sites. Acute effects of cooling were assessed by randomly assigning subjects to high-dose or low-dose cooling for one hour using an active cooling vest and cap (Life Enhancement Technologies, Santa Clara, CA). Settings were individualized to maintain the cooling garments at 55 F for the high-dose treatment and 70 F for the low-dose treatment. Both patients and examining investigators were blinded to treatment assignments. The MSFC and visual acuity/contrast sensitivity were assessed before and 30 minutes after treatment. The following week, subjects had an identical visit with the alternate cooling treatment. Chronic effects of cooling were assessed by randomly assigning the same subjects to unblinded daily home cooling or observation for 4 weeks. All subjects completed the Rochester Fatigue Diary (RFD) twice weekly and subjective measures of strength, cognition, and energy level daily. At the end of the period, subjects completed the Modified Fatigue Impact Scale (MFIS) and underwent another high-dose cooling session with assessment of the MSFC and vision. After a one-week washout period, subjects crossed over to the alternate 4-week treatment. Oral temperatures were reduced with both acute treatments (0.8 +/- .06 F, high and 0.5 +/- .06 F, low). While mean MSFC did not change significantly during individual cooling sessions, post hoc analysis pooling the 3 high-dose cooling sessions revealed an improvement in MSFC scores (acute phase 0.064 +/- 0.020, p = 0.0013; chronic phase 0.044 +/- 0.021, p = 0.0368) from before to after cooling. The change in MSFC scores during the acute cooling sessions was not related to the extent of change in oral temperatures. Both the RFD score and the MFIS indicate a significantly lower fatigue level during the cooling month compared to observation (RFD, 2.53 +/- 0.83,p = 0.0033; MFIS 7.63 +/- 1.56, p = 0.0001).

Performance of the dark energy camera liquid nitrogen cooling system

NASA Astrophysics Data System (ADS)

Cease, H.; Alvarez, M.; Alvarez, R.; Bonati, M.; Derylo, G.; Estrada, J.; Flaugher, B.; Flores, R.; Lathrop, A.; Munoz, F.; Schmidt, R.; Schmitt, R. L.; Schultz, K.; Kuhlmann, S.; Zhao, A.

2014-01-01

The Dark Energy Camera, the Imager and its cooling system was installed onto the Blanco 4m telescope at the Cerro Tololo Inter-American Observatory in Chile in September 2012. The imager cooling system is a LN2 two-phase closed loop cryogenic cooling system. The cryogenic circulation processing is located off the telescope. Liquid nitrogen vacuum jacketed transfer lines are run up the outside of the telescope truss tubes to the imager inside the prime focus cage. The design of the cooling system along with commissioning experiences and initial cooling system performance is described. The LN2 cooling system with the DES imager was initially operated at Fermilab for testing, then shipped and tested in the Blanco Coudé room. Now the imager is operating inside the prime focus cage. It is shown that the cooling performance sufficiently cools the imager in a closed loop mode, which can operate for extended time periods without maintenance or LN2 fills.

Nano scale dynamics of bubble nucleation in confined liquid subjected to rapid cooling: Effect of solid-liquid interfacial wettability

NASA Astrophysics Data System (ADS)

Hasan, Mohammad Nasim; Rabbi, Kazi Fazle; Mukut, K. M.; Tamim, Saiful Islam; Faisal, A. H. M.

2017-06-01

This study focuses on the occurrence of bubble nucleation in a liquid confined in a nano scale confinement and subjected to rapid cooling at one of its wall. Due to the very small size scale of the present problem, we adopt the molecular dynamics (MD) approach. The liquid (Argon) is confined within two solid (Platinum) walls. The temperature of the upper wall of the confinement is maintained at 90 K while the lower wall is being cooled rapidly to 50 K from initial equilibrium temperature of 90 K within 0.1 ns. This results in the nucleation and formation of nanobubbles in the liquid. The pattern of bubble nucleation has been studied for three different conditions of solid-liquid interfacial wettability such as hydrophilic, hydrophobic and neutral. Behavior of bubble nucleation is significantly different in the three case of solid-liquid interfacial wettability. In case of the hydrophobic confinement (weakly adsorbing), the liquid cannot achieve deeper metastability; vapor layers appear immediately on the walls. In case of the neutral confinement (moderately adsorbing), bubble nucleation is promoted by the walls where the nucleation is heterogeneous. In case of the hydrophilic walls (strongly adsorbing) bubbles are developed inside the liquid; that is the nucleation process is homogeneous. The variation in bubble nucleation under different conditions of surface wettability has been studied by the analysis of number density distribution, spatial temperature distribution, spatial number density distribution and heat flux through the upper and lower walls of the confinement. The present study indicates that the variation of heat transfer efficiency due to different surface wettability has significant effect on the size, shape and location of bubble nucleation in case rapid cooling of liquid in nano confinement.

Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases from Internal-Combustion Engines

NASA Technical Reports Server (NTRS)

Gerrish, Harold C; Tessmann, Arthur M

1935-01-01

The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.

Summary of Laboratory and Field Comfort Studies on Candidate Fabrics for a Year-Round Uniform

DTIC Science & Technology

1986-06-01

differences were particularly sharp under wearing conditions involving mild to heavy sweating at the skin- garment interface. 5 The evaluation of comfort using...34 would be inter- preted as meaning that the garment was "mildly scratchy". If no comment was made by the wearer, a rating of 5, "totally comfortable...25 women used in this study had no difficulty in detecting these differences even though the garments were presented randomly without identifying

New model system in radiation cryochemistry:. hyperquenched glassy water

NASA Astrophysics Data System (ADS)

Bednarek, Janusz; Plonka, Andrzej; Hallbrucker, Andreas; Mayer, Erwin

1999-08-01

Radicals generated by high-energy irradiation of liquid water, short-lived at ambient temperature, can be studied at cryogenic temperatures after irradiating water and dilute aqueous solutions in their glassy states which can be obtained by so-called hyperquenching of the liquids at cooling rates of ˜10 6-10 7 K s -1. In the glassy states of hyperquenched dilute aqueous solutions there is no problem with phase separation and radiolysis of glassy water is quite distinct from radiolysis of polycrystalline ice obtained from liquid water on slow-cooling in liquid nitrogen.

Metal Alloy Compositions And Process Background Of The Invention

DOEpatents

Flemings, Merton C.; Martinez-Ayers, Raul A.; de Figueredo, Anacleto M.; Yurko, James A.

2003-11-11

A skinless metal alloy composition free of entrapped gas and comprising primary solid discrete degenerate dendrites homogeneously dispersed within a secondary phase is formed by a process wherein the metal alloy is heated in a vessel to render it a liquid. The liquid is then rapidly cooled while vigorously agitating it under conditions to avoid entrapment of gas while forming solid nuclei homogeneously distributed in the liquid. Agitation then is ceased when the liquid contains a small fraction solid or the liquid-solid alloy is removed from the source of agitation while cooling is continued to form the primary solid discrete degenerate dendrites in liquid secondary phase. The solid-liquid mixture then can be formed such as by casting.

Compression Stockings May Ameliorate Orthostatic Intolerance in Astronauts After Short-Duration Space Flight

NASA Technical Reports Server (NTRS)

Platts, Steven H.; Lee, Stuart M. C.; Westby, Christian M.; Ribeiro, L. Christine; Stenger, Michael B.

2011-01-01

Orthostatic intolerance following spaceflight has been observed since the early days of manned spaceflight, and no countermeasure has been 100% effective. During re-entry NASA astronauts currently wear an inflatable anti-gravity suit (AGS) which compresses the legs and abdomen, but this device is uncomfortable and loses effectiveness upon egress from the Space Shuttle. We previously reported that foot-to-thigh, gradient compression stockings were comfortable and effective during standing after Shuttle missions. More recently we showed in a ground-based model of spaceflight that the addition of splanchnic compression to the foot-to-thigh compression stockings, creating foot-to-breast high compression, improved orthostatic tolerance in hypovolemic subjects to a level similar to the AGS. Purpose: To evaluate a new three-piece, foot-to-breast high gradient compression garment as a countermeasure to post-spaceflight orthostatic intolerance. Methods: Fourteen astronauts completed this experiment (7 control, 7 treatment) following Space Shuttle missions lasting 12-16 days. Treatment subjects were custom-fitted for a three-piece, foot-to-breast high compression garment consisting of shorts and foot-to-thigh stockings. The garments were constructed to provide 55 mmHg compression at the ankle and decreased gradually to 15 mmHg over the abdomen. Orthostatic testing occurred 30 days before flight (without garments) and 2 hours after flight (with garments for treatment group only) on landing day. Blood pressure (BP) and heart rate (HR) were acquired for 2 minutes while the subject lay prone and then for 3.5 minutes after the subject stood. Data are reported as mean +/- SE. Results: The compression garment successfully prevented the tachycardia and hypotension typically seen post-spaceflight. On landing day, treatment subjects had a smaller change in HR (11+/-1 vs. 21+/-4 beats/min, p< or =0.05) and no decrease in systolic BP (2+/-4 vs. -9+/-2 mmHg, p< or =0.05). Garments also received good comfort ratings and were relatively easy to don. Conclusion: In this small group of astronauts, foot-to-breast high gradient compression garments seem to have prevented these negative effects of spaceflight on the cardiovascular responses to standing.

Field-Based Pre-Cooling for On-Court Tennis Conditioning Training in the Heat

PubMed Central

Duffield, Rob; Bird, Stephen P.; Ballard, Robert J.

2011-01-01

The present study investigated the effects of pre-cooling for on- court, tennis-specific conditioning training in the heat. Eight highly-trained tennis players performed two on-court conditioning sessions in 35°C, 55% Relative Humidity. Sessions were randomised, involved either a pre-cooling or control session, and consisted of 30-min of court- based, tennis movement drills. Pre-cooling involved 20-min of an ice-vest and cold towels to the head/neck and legs, followed by warm-up in a cold compression garment. On-court movement distance was recorded by 1Hz Global Positioning Satellite (GPS) devices, while core temperature, heart rate and perceptual exertion and thermal stress were also recorded throughout the session. Additionally, mass and lower-body peak power during repeated counter-movement jumps were measured before and after each session. No significant performance differences were evident between conditions, although a moderate-large effect (d = 0.7-1.0; p > 0.05) was evident for total (2989 ± 256 v 2870 ± 159m) and high-intensity (805 ± 340 v 629 ± 265m) distance covered following pre-cooling. Further, no significant differences were evident between conditions for rise in core temperature (1.9 ± 0.4 v 2. 2 ± 0.4°C; d > 0.9; p > 0.05), although a significantly smaller change in mass (0.9 ± 0.3 v 1. 3 ± 0.3kg; p < 0.05) was present following pre-cooling. Perceived thermal stress and exertion were significantly lower (d > 1.0; p < 0.05) during the cooling session. Finally, lower-body peak power did not differ between conditions before or after training (d < 0.3; p > 0.05). Conclusions: Despite trends for lowered physiological load and increased distances covered following cooling, the observed responses were not significantly different or as explicit as previously reported laboratory-based pre-cooling research. Key points Pre-cooling did not significantly enhance training performance or reduce physiological load for tennis training in the heat, although trends indicate some benefits for both. Pre-cooling can reduce perceptual strain of on-court tennis training in the heat to improve perceptual load of training sessions. Court-side pre-cooling may not be of sufficient volume to invoke large physiological changes. PMID:24149886

Apparatus for the liquefaction of natural gas and methods relating to same

DOEpatents

Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID; Turner, Terry D [Ammon, ID; Carney, Francis H [Idaho Falls, ID

2009-09-29

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream.

Information technology equipment cooling system

DOEpatents

Schultz, Mark D.

2014-06-10

According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools warm air generated by the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat from the rack of information technology equipment.

Complexity of Sizing for Space Suit Applications

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Benson, Elizabeth

2009-01-01

The `fit? of a garment is often considered to be a subjective measure of garment quality. However, some experts attest that a complaint of poor garment fit is a symptom of inadequate or excessive ease, the space between the garment and the wearer. Fit has traditionally been hard to quantify, and space suits are an extreme example, where fit is difficult to measure but crucial for safety and operability. A proper space suit fit is particularly challenging because of NASA?s need to fit an incredibly diverse population (males and females from the 1st to 99th percentile) while developing a minimum number of space suit sizes. Because so few sizes are available, the available space suits must be optimized so that each fits a large segment of the population without compromising the fit of any one wearer.

Factors associated with knowledge about breastfeeding among female garment workers in Dhaka city.

PubMed

Afrose, Lucen; Banu, Bilkis; Ahmed, Kazi R; Khanom, Khurshida

2012-01-01

Knowledge about breastfeeding among women is very important for healthy children. The present study aims to determine the level of knowledge and factors associated with knowledge on breastfeeding among female garment workers in a selected garment factory in Dhaka city. A cross-sectional study was conducted among 200 female garment workers in the reproductive age group (15-49 years). Data were collected through a pre-tested questionnaire using the face-to-face interview method. Bivariate and multivariate analysis was done to determine the association between sociodemographic variables and knowledge on breastfeeding. The study showed that, overall the level of knowledge regarding breastfeeding is very poor (88%) among the study subjects. Most of the respondents have very poor knowledge regarding advantages of exclusive breastfeeding (89%) and breastfeeding (100%). In contrast, a majority have good knowledge on duration of exclusive breastfeeding (74%) and breastfeeding (66%). No significant association was found between the knowledge score of breastfeeding with remaining socio-demographic variables like age, marital status, family income and expenditure. Education is significantly (p<0.001) associated with a higher total knowledge score of breastfeeding. Women with secondary level of education had a significantly higher (p<0.001) level of total knowledge score than other categories (illiterate, primary and higher secondary) of education. A large proportion of female garment workers had inadequate knowledge regarding breastfeeding. It is also important that health education on breastfeeding is urgently provided to the female garments workers of Bangladesh.

A heat transfer model for incorporating carbon foam fabrics in firefighter's garment

NASA Astrophysics Data System (ADS)

Elgafy, Ahmed; Mishra, Sarthak

2014-04-01

In the present work, a numerical study was performed to predict and investigate the performance of a thermal protection system for firefighter's garment consisting of carbon foam fabric in both the outer shell and the thermal liner elements. Several types of carbon foam with different thermal conductivity, porosity, and density were introduced to conduct a parametric study. Additionally, the thickness of the introduced carbon foam fabrics was varied to acquire optimum design. Simulation was conducted for a square planar 2D geometry of the clothing comprising of different fabric layers and a double precision pressure-based implicit solver, under transient state condition was used. The new anticipated thermal protection system was tested under harsh thermal environmental conditions that firefighters are exposed to. The parametric study showed that employing carbon foam fabric with one set of designed parameters, weight reduction of 33 % in the outer shell, 56 % in the thermal liner and a temperature reduction of 2 % at the inner edge of the garment was achieved when compared to the traditional firefighter garment model used by Song et al. (Int J Occup Saf Ergon 14:89-106, 2008). Also, carbon foam fabric with another set of designed parameters resulted in a weight reduction of 25 % in the outer shell, 28 % in the thermal liner and a temperature reduction of 6 % at the inner edge of the garment. As a result, carbon foam fabrics make the firefighter's garment more protective, durable, and lighter in weight.

Efficacy of Liquid, Air, and Phase Change Material Torso Cooling During Light Exercise While Wearing NBC Clothing

DTIC Science & Technology

1998-03-01

and Thermal Comfort 6 Blood Sampling 6 Statistical Analyses 6 RESULTS 7 Indices of Hydration Status 7 Liquid-Cooling and PCM Cooling Vests...of Uncooled Sites 12 Vapour Pressure 12 Ratings of Thermal Comfort and Perceived Exertion 18 Indices of Heat Tolerance 18 DISCUSSION 20...ill Figures 8A and B Changes in ratings of thermal comfort of the torso and whole body during light exercise at 40°C and 30% relative humidity while

Liquid cooled data center design selection

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

Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

Input data, specifying aspects of a thermal design of a liquid cooled data center, is obtained. The input data includes data indicative of ambient outdoor temperature for a location of the data center; and/or data representing workload power dissipation for the data center. The input data is evaluated to obtain performance of the data center thermal design. The performance includes cooling energy usage; and/or one pertinent temperature associated with the data center. The performance of the data center thermal design is output.

Cooling and solidification of heavy hydrocarbon liquid streams

DOEpatents

Antieri, Salvatore J.; Comolli, Alfred G.

1983-01-01

A process and apparatus for cooling and solidifying a stream of heavy hydrocarbon material normally boiling above about 850.degree. F., such as vacuum bottoms material from a coal liquefaction process. The hydrocarbon stream is dropped into a liquid bath, preferably water, which contains a screw conveyor device and the stream is rapidly cooled, solidified and broken therein to form discrete elongated particles. The solid extrudates or prills are then dried separately to remove substantially all surface moisture, and passed to further usage.

Effects of a Circulating-water Garment and Forced-air Warming on Body Heat Content and Core Temperature

PubMed Central

Taguchi, Akiko; Ratnaraj, Jebadurai; Kabon, Barbara; Sharma, Neeru; Lenhardt, Rainer; Sessler, Daniel I.

2005-01-01

Background: Forced-air warming is sometimes unable to maintain perioperative normothermia. We therefore compared heat transfer, regional heat distribution, and core rewarming of forced-air warming with a novel circulating-water garment. Methods: Nine volunteers were each evaluated on two randomly ordered study days. They were anesthetized and cooled to a core temperature near 34°C. The volunteers were subsequently warmed for 2.5 hours with either a circulating-water garment or forced-air cover. Overall, heat balance was determined from the difference between cutaneous heat loss (thermal flux transducers) and metabolic heat production (oxygen consumption). Average arm and leg (peripheral) tissue temperatures were determined from 18 intramuscular needle thermocouples, 15 skin thermal flux transducers, and “deep” arm and foot thermometers. Results: Heat production (≈ 60 kcal/h) and loss (≈45 kcal/h) were similar with each treatment before warming. The increase in heat transfer across anterior portions of the skin surface was similar with each warming system (≈65 kcal/h). Forced-air warming had no effect on posterior heat transfer whereas circulating-water transferred 21 ± 9 kcal/h through the posterior skin surface after a half hour of warming. Over 2.5 h, circulating-water thus increased body heat content 56% more than forced air. Core temperatures thus increased faster than with circulating water than forced air, especially during the first hour, with the result that core temperature was 1.1 ± 0.7°C greater after 2.5 h (P < 0.001). Peripheral tissue heat content increased twice as much as core heat content with each device, but the core-to-peripheral tissue temperature gradient remained positive throughout the study. Conclusions: The circulating-water system transferred more heat than forced air, with the difference resulting largely from posterior heating. Circulating water rewarmed patients 0.4°C/h faster than forced air. A substantial peripheral-to-core tissue-temperature gradient with each device indicated that peripheral tissues insulated the core, thus slowing heat transfer. PMID:15114200

Cooled electronic system with thermal spreaders coupling electronics cards to cold rails

DOEpatents

Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

2013-07-23

Liquid-cooled electronic systems are provided which include an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket or removal of the card from the socket. A liquid-cooled cold rail is disposed at the one end of the socket, and a thermal spreader couples the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The thermally conductive extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

Method of fabricating a cooled electronic system

DOEpatents

Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

2014-02-11

A method of fabricating a liquid-cooled electronic system is provided which includes an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket. The method includes providing a liquid-cooled cold rail at the one end of the socket, and a thermal spreader to couple the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

Influence of Cooling Condition on the Performance of Grinding Hardened Layer in Grind-hardening

NASA Astrophysics Data System (ADS)

Wang, G. C.; Chen, J.; Xu, G. Y.; Li, X.

2018-02-01

45# steel was grinded and hardened on a surface grinding machine to study the effect of three different cooling media, including emulsion, dry air and liquid nitrogen, on the microstructure and properties of the hardened layer. The results show that the microstructure of material surface hardened with emulsion is pearlite and no hardened layer. The surface roughness is small and the residual stress is compressive stress. With cooling condition of liquid nitrogen and dry air, the specimen surface are hardened, the organization is martensite, the surface roughness is also not changed, but high hardness of hardened layer and surface compressive stress were obtained when grinding using liquid nitrogen. The deeper hardened layer grinded with dry air was obtained and surface residual stress is tensile stress. This study provides an experimental basis for choosing the appropriate cooling mode to effectively control the performance of grinding hardened layer.

Comparison of immersed liquid and air cooling of NASA's Airborne Information Management System

NASA Technical Reports Server (NTRS)

Hoadley, A. W.; Porter, A. J.

1992-01-01

The Airborne Information Management System (AIMS) is currently under development at NASA Dryden Flight Research Facility. The AIMS is designed as a modular system utilizing surface mounted integrated circuits in a high-density configuration. To maintain the temperature of the integrated circuits within manufacturer's specifications, the modules are to be filled with Fluorinert FC-72. Unlike ground based liquid cooled computers, the extreme range of the ambient pressures experienced by the AIMS requires the FC-72 be contained in a closed system. This forces the latent heat absorbed during the boiling to be released during the condensation that must take within the closed module system. Natural convection and/or pumping carries the heat to the outer surface of the AIMS module where the heat transfers to the ambient air. This paper will present an evaluation of the relative effectiveness of immersed liquid cooling and air cooling of the Airborne Information Management System.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Comparison of immersed liquid and air cooling of NASA's Airborne Information Management System

NASA Astrophysics Data System (ADS)

Hoadley, A. W.; Porter, A. J.

1992-07-01

The Airborne Information Management System (AIMS) is currently under development at NASA Dryden Flight Research Facility. The AIMS is designed as a modular system utilizing surface mounted integrated circuits in a high-density configuration. To maintain the temperature of the integrated circuits within manufacturer's specifications, the modules are to be filled with Fluorinert FC-72. Unlike ground based liquid cooled computers, the extreme range of the ambient pressures experienced by the AIMS requires the FC-72 be contained in a closed system. This forces the latent heat absorbed during the boiling to be released during the condensation that must take within the closed module system. Natural convection and/or pumping carries the heat to the outer surface of the AIMS module where the heat transfers to the ambient air. This paper will present an evaluation of the relative effectiveness of immersed liquid cooling and air cooling of the Airborne Information Management System.

Technology advancement of the electrochemical CO2 concentrating process

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Heppner, D. B.; Hallick, T. M.; Woods, R. R.

1979-01-01

Two multicell, liquid-cooled, advanced electrochemical depolarized carbon dioxide concentrator modules were fabricated. The cells utilized advanced, lightweight, plated anode current collectors, internal liquid cooling and lightweight cell frames. Both were designed to meet the carbon dioxide removal requirements of one-person, i.e., 1.0 kg/d (2.2 lb/d).

High-Performance Computing Data Center | Computational Science | NREL

Science.gov Websites

liquid cooling to achieve its very low PUE, then captures and reuses waste heat as the primary heating dry cooler that uses refrigerant in a passive cycle to dissipate heat-is reducing onsite water Measuring efficiency through PUE Warm-water liquid cooling Re-using waste heat from computing components

Splash bar for cooling tower fill assembly

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

Stackhouse, D.W.; Heidl, S.C.

1987-11-10

A crossflow cooling tower fill assembly for allowing liquid to fall down through the fill assembly and for allowing cooling air to flow through the fill assembly transverse to the flow of the liquid in order to cool the liquid is described. The assembly comprises: longitudinal splash bars; and means for supporting the splash bars so that the splash bars are substantially horizontal and parallel to one another and arranged in vertically spaced, substantially horizontal planes. The splash bars in each plane are horizontally spaced from one another to allow the liquid to fall down between the splash bars tomore » the planes of splash bars below. Each splash bar includes a substantially horizontal, longitudinally extending top web member having (1) longitudinally extending, downwardly projecting vertical side web members, both of the side web members having a lower longitudinal edge with a longitudinally extending, inwardly projecting flange, and (2) at least one longitudinally extending, downardly projecting rib web member between the side web members. Each rib web member has a lower longitudinal edge with a longitudinally extending, laterally projecting flange.« less

Liquid Hydrogen Recirculation System for Forced Flow Cooling Test of Superconducting Conductors

NASA Astrophysics Data System (ADS)

Shirai, Y.; Kainuma, T.; Shigeta, H.; Shiotsu, M.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.; Yoshinaga, S.

2017-12-01

The knowledge of forced flow heat transfer characteristics of liquid hydrogen (LH2) is important and necessary for design and cooling analysis of high critical temperature superconducting devices. However, there are few test facilities available for LH2 forced flow cooling for superconductors. A test system to provide a LH2 forced flow (∼10 m/s) of a short period (less than 100 s) has been developed. The test system was composed of two LH2 tanks connected by a transfer line with a controllable valve, in which the forced flow rate and its period were limited by the storage capacity of tanks. In this paper, a liquid hydrogen recirculation system, which was designed and fabricated in order to study characteristics of superconducting cables in a stable forced flow of liquid hydrogen for longer period, was described. This LH2 loop system consists of a centrifugal pump with dynamic gas bearings, a heat exchanger which is immersed in a liquid hydrogen tank, and a buffer tank where a test section (superconducting wires or cables) is set. The buffer tank has LHe cooled superconducting magnet which can produce an external magnetic field (up to 7T) at the test section. A performance test was conducted. The maximum flow rate was 43.7 g/s. The lowest temperature was 22.5 K. It was confirmed that the liquid hydrogen can stably circulate for 7 hours.

Conduction Cooling of a Niobium SRF Cavity Using a Cryocooler

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

Feldman, Joshua; Geelhoed, Michael; Dhuley, Ram

Superconducting Radio Frequency (SRF) cavities are the primary choice for accelerating charged particles in high-energy research accelerators. Institutions like Fermilab use SRF cavities because they enable significantly higher gradients and quality factors than normal-conducting RF cavities and DC voltage cavities. To cool the SRF cavities to low temperatures (typically around 2 K), liquid helium refrigerators are used. Producing and maintaining the necessary liquid helium requires large, elaborate cryogenic plants involving dewars, compressors, expansion engines, and recyclers. The cost, complexity, and space required for such plants is part of the reason that industry has not yet adopted SRF-based accelerators. At themore » Illinois Accelerator Research Center (IARC) at Fermilab, our team seeks to make SRF technology accessible not only to large research accelerators, but to industry as well. If we eliminate the complexity associated with liquid helium plants, SRF-based industrial accelerators may finally become a reality. One way to do this is to eliminate the use of liquid helium baths altogether and develop a brand-new cooling technique for SRF cavities: conduction cooling using a cryocooler. Recent advances in SRF technology have made it possible to operate SRF cavities at 4 K, a temperature easily achievable using commercial cryocoolers. Our IARC team is taking advantage of this technology to cool SRF cavities.« less

Internal-liquid-film-cooling Experiments with Air-stream Temperatures to 2000 Degrees F. in 2- and 4-inch-diameter Horizontal Tubes

NASA Technical Reports Server (NTRS)

Kinney, George R; Abramson, Andrew E; Sloop, John L

1952-01-01

Report presents the results of an investigation conducted to determine the effectiveness of liquid-cooling films on the inner surfaces of tubes containing flowing hot air. Experiments were made in 2- and 4-inch-diameter straight metal tubes with air flows at temperatures from 600 degrees to 2000 degrees F. and diameter Reynolds numbers from 2.2 to 14 x 10(5). The film coolant, water, was injected around the circumference at a single axial position on the tubes at flow rates from 0.02 to .24 pound per second per foot of tube circumference (0.8 to 12 percent of the air flow). Liquid-coolant films were established and maintained around and along the tube wall in concurrent flow with the hot air. The results indicated that, in order to film cool a given surface area with as little coolant flow as possible, it may be necessary to limit the flow of coolant introduced at a single axial position and to introduce it at several axial positions. The flow rate of inert coolant required to maintain liquid-film cooling over a given area of tube surface can be estimated when the gas-flow conditions are known by means of a generalized plot of the film-cooling data.

Cold-stage microscopy system for fast-frozen liquids.

PubMed

Talmon, Y; Davis, H T; Scriven, L E; Thomas, E L

1979-06-01

The least artifact-laden fixation technique for examining colloidal suspensions, microemulsions, and other microstructured liquids in the electron microscope appears to be thermal fixation, i.e., ultrafast freezing of the liquid specimen. For rapid-enough cooling and for observation in TEM/STEM a thin sample is needed. The need is met by trapping a thin layer ( approximately 100 nm) of liquid between two polyimide films ( approximately 40 nm thickness) mounted on copper grids and immersing the resulting sandwich in liquid nitrogen at its melting point. For liquids containing water, polyimides films are used since this polymer is far less susceptible to the electron beam damage observed for the commonly used polymer films such as Formvar and collodion in contact with ice. Transfer of the frozen sample into the microscope column without deleterious frost deposition and warming is accomplished with a new transfer module for the cooling stage of the JEOL JEM-100CX microscope, which makes a true cold stage out of a device originally intended for cooling specimens inside the column. Sample results obtained with the new fast-freeze, cold-stage microscopy system are given.

A Freezable Heat Exchanger for Space Suit Radiator Systems

NASA Technical Reports Server (NTRS)

Nabity, James A.; Mason, Georgia R.; Copeland, Robert J.; Trevino, Luis a.

2008-01-01

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut s metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. Radiators have no moving parts and are thus highly reliable. Past freezable radiators have been too heavy, but the weight can be greatly reduced by placing a small and freeze tolerant heat exchanger between the astronaut and radiator, instead of making the very large radiator freeze tolerant. Therefore, the key technological innovation to improve space suit radiator performance was the development of a lightweight and freezable heat exchanger that accommodates the variable heat load generated by the astronaut. Herein, we present the heat transfer performance of a newly designed heat exchanger that endured several freeze / thaw cycles without any apparent damage. The heat exchanger was also able to continuously turn down or turn up the heat rejection to follow the variable load.

Structural relaxation and thermal conductivity of high-pressure formed, high-density di-n-butyl phthalate glass and pressure induced departures from equilibrium state

NASA Astrophysics Data System (ADS)

Johari, G. P.; Andersson, Ove

2017-06-01

We report a study of structural relaxation of high-density glasses of di-n-butyl phthalate (DBP) by measuring thermal conductivity, κ, under conditions of pressure and temperature (p,T) designed to modify both the vibrational and configurational states of a glass. Various high-density glassy states of DBP were formed by (i) cooling the liquid under a fixed high p and partially depressurizing the glass, (ii) isothermal annealing of the depressurized glass, and (iii) pressurizing the glass formed by cooling the liquid under low p. At a given low p, κ of the glass formed by cooling under high p is higher than that of the glass formed by cooling under low p, and the difference increases as glass formation p is increased. κ of the glass formed under 1 GPa is ˜20% higher at ambient p than κ of the glass formed at ambient p. On heating at low p, κ decreases until the glass to liquid transition range is reached. This is the opposite of the increase in κ observed when a glass formed under a certain p is heated under the same p. At a given high p, κ of the low-density glass formed by cooling at low p is lower than that of the high-density glass formed by cooling at that high p. On heating at high p, κ increases until the glass to liquid transition range is reached. The effects observed are due to a thermally assisted approach toward equilibrium at p different from the glass formation p. In all cases, the density, enthalpy, and entropy would change until the glasses become metastable liquids at a fixed p, thus qualitatively relating κ to variation in these properties.

Electrostimulation's enhancement of recovery during a rugby preseason.

PubMed

Beaven, C Martyn; Cook, Christian; Gray, David; Downes, Paul; Murphy, Ian; Drawer, Scott; Ingram, John R; Kilduff, Liam P; Gill, Nicholas

2013-01-01

Rugby preseason training involves high-volume strength and conditioning training, necessitating effective management of the recovery-stress state to avoid overtraining and maximize adaptive gains. Compression garments and an electrostimulation device have been proposed to improve recovery by increasing venous blood flow. These devices were assessed using salivary testosterone and cortisol, plasma creatine kinase, and player questionnaires to determine sleep quality, energy level, mood, and enthusiasm. Twenty-five professional rugby players were assigned to 1 of 2 treatments (compression garment or a concurrent combination of electrostimulation and compression) in a crossover design over 2 × 2-wk training blocks. Substantial benefits were observed in self-assessed energy levels (effect size [ES] 0.86), and enthusiasm (ES 0.80) as a result of the combined treatment when compared with compression-garment use. The combination treatment had no discernable effect on salivary hormones, with no treatment effect observed. The electrostimulation device did tend to accelerate the return of creatine kinase to baseline levels after 2 preseason rugby games when compared with the compression-garment intervention (ES 0.61; P = .08). Electrostimulation elicited psychometric and physiological benefits reflective of an improved recovery-stress state in professional male rugby players when combined with a lower-body compression garment.

The experience of scar management for adults with burns: An interpretative phenomenological analysis.

PubMed

Martin, C; Bonas, S; Shepherd, L; Hedges, E

2016-09-01

Burns can have both physical and psychological effects on individuals. Pressure garments and silicone gels are used to improve the aesthetic appearance and functions of the skin, but these treatments have been associated with various physical, emotional, sexual and social difficulties. Interpretative phenomenological analysis (IPA) was used to explore participants' experiences of scar management. IPA examines individual experiences before comparing results across cases, and is suited to capture the different ways in which individuals experience a phenomena as well as cautiously looking at patterns across cases. Eight burn patients who had experienced scar management, including pressure garments, were interviewed. Two superordinate themes were identified: Assimilation of Pressure Garment Identity, and Psychosocial Functions of the Pressure Garments. The findings offered insight into the positive and negative experiences of scar management, describing the diverse personal and social functions of the pressure garments and how they became integrated into participants' identities. By understanding the individual nature of these experiences, healthcare professionals can enhance support around these issues and potentially aid adherence to treatment. Further research with different demographic groups as well as for other burn treatments would be useful to develop and contextualise these findings. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Thermal conductance of space suit insulations, thermal micrometeroid garments, and other insulations

NASA Technical Reports Server (NTRS)

Richardson, D. L.; Stevens, J. M.

1976-01-01

The thermal protection capabilities of development and operational thermal micrometeroid garments and other insulations were evaluated. The relationship among sample thermal conductance, surface temperature, and compressive loads was empirically defined.

Self-contained clothing system provides protection against hazardous environments

NASA Technical Reports Server (NTRS)

1966-01-01

Self-contained clothing system protects personnel against hazardous environments. The clothing has an environmental control system and a complete protection envelope consisting of an outer garment, inner garment, underwear, boots, gloves, and helmet.

Optimal bus temperature for thermal comfort during a cool day.

PubMed

Velt, K B; Daanen, H A M

2017-07-01

A challenge for electric buses is to minimize heating and cooling power to maximally extend the driving range, but still provide sufficient thermal comfort for the driver and passengers. Therefore, we investigated the thermal sensation (TS) and thermal comfort (TC) of passengers in buses during a cool day (temperature 13.4 ± 0.5 °C, relative humidity (RH) 60 ± 5.8%) typical for the Dutch temperate maritime climate. 28 Males and 72 females rated TS and TC and gave information on age, stature, body weight and worn garments. The temperature in the bus of 22.5 ± 1.1 °C and RH of 59.9 ± 5.8% corresponded to a slightly warm feeling (TS = 0.85 ± 1.06) and TC of 0.39 ± 0.65. TS related significantly to bus temperature, clothing insulation and age. Linear regression based on these parameters showed that the temperature in the bus corresponding to TC = 0 and TS = 0 would have been 20.9 ± 0.6 °C. In conclusion, a 1.6 °C lower bus temperature during the investigated cool day probably would have led to less thermal discomfort and energy savings of electrical busses. The methodology to relate climatic measurements to subjective assessments is currently employed in a wider climatic range and may prove to be useful to find a better balance between thermal comfort and energy savings of the bus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-Shock Garment

NASA Technical Reports Server (NTRS)

1996-01-01

Ames Research Center developed a prototype pressure suit for hemophiliac children, based on research of astronauts' physiological responses in microgravity. Zoex Corporation picked up the design and patents and developed an anti-shock garment for paramedic use. Marketed by Dyna Med, the suit reverses the effect of shock on the body's blood distribution by applying counterpressure to the legs and abdomen, returning blood to vital organs and stabilizing body pressure until the patient reaches a hospital. The DMAST (Dyna Med Anti-Shock Trousers) employ lower pressure than other shock garments, and are non-inflatable.

Evaluation of the health risks to garment workers in the city of Xambrê-PR, Brazil.

PubMed

Sant'Ana, Marco Antônio; Kovalechen, Fabrício

2012-01-01

This study evaluated the risks for cardiovascular disease and the life habits of garment industry workers in northwestern Paraná state, Brazil. The following parameters were assessed: body composition, cardiorespiratory fitness, eating habits and physical activities by garment industry workers. Cardiovascular risk was observed in some of the studied subjects, in the form of high BMI and reduced maximal oxygen uptake. The development of a workplace quality-of-life program is suggested, aiming to stimulate the development of physical activities to improve the cardiovascular conditioning of workers.

Thermal control structure and garment

DOEpatents

Klett, James W [Knoxville, TN; Cameron, Christopher Stan [Sanford, NC

2012-03-13

A flexible thermally conductive structure. The structure generally includes a plurality of thermally conductive yarns, at least some of which are at least partially disposed adjacent to an elastomeric material. Typically, at least a portion of the plurality of thermally conductive yarns is configured as a sheet. The yarns may be constructed from graphite, metal, or similar materials. The elastomeric material may be formed from urethane or silicone foam that is at least partially collapsed, or from a similar material. A thermal management garment is provided, the garment incorporating a flexible thermally conductive structure.

Simplified thermochemistry of oxygen in lithium and sodium for liquid metal cooling systems

NASA Technical Reports Server (NTRS)

Tower, L. K.

1972-01-01

Plots of oxygen chemical potential against composition of lithium-oxygen solutions and sodium-oxygen solutions for a range of temperature were constructed. For each liquid metal two such plots were prepared. For one plot ideal solution behavior was assumed. For the other plot, existing solubility limit data for oxygen in the liquid metal were used to determine a first-order term for departure from ideality. The use of the plots in evaluating the oxygen gettering capability of refractory metals in liquid metal cooling systems is illustrated by a simple example involving lithium, oxygen, and hafnium.

Superconducting magnet cooling system

DOEpatents

Vander Arend, Peter C.; Fowler, William B.

1977-01-01

A device is provided for cooling a conductor to the superconducting state. The conductor is positioned within an inner conduit through which is flowing a supercooled liquid coolant in physical contact with the conductor. The inner conduit is positioned within an outer conduit so that an annular open space is formed therebetween. Through the annular space is flowing coolant in the boiling liquid state. Heat generated by the conductor is transferred by convection within the supercooled liquid coolant to the inner wall of the inner conduit and then is removed by the boiling liquid coolant, making the heat removal from the conductor relatively independent of conductor length.

Liquid Acquisition Device Testing with Sub-Cooled Liquid Oxygen

NASA Technical Reports Server (NTRS)

Jurns, John M.; McQuillen, John B.

2008-01-01

When transferring propellant in space, it is most efficient to transfer single phase liquid from a propellant tank to an engine. In earth s gravity field or under acceleration, propellant transfer is fairly simple. However, in low gravity, withdrawing single-phase fluid becomes a challenge. A variety of propellant management devices (PMD) are used to ensure single-phase flow. One type of PMD, a liquid acquisition device (LAD) takes advantage of capillary flow and surface tension to acquire liquid. Previous experimental test programs conducted at NASA have collected LAD data for a number of cryogenic fluids, including: liquid nitrogen (LN2), liquid oxygen (LOX), liquid hydrogen (LH2), and liquid methane (LCH4). The present work reports on additional testing with sub-cooled LOX as part of NASA s continuing cryogenic LAD development program. Test results extend the range of LOX fluid conditions examined, and provide insight into factors affecting predicting LAD bubble point pressures.

Work, gender roles, and health: neglected mental health issues among female workers in the ready-made garment industry in Bangladesh

PubMed Central

Akhter, Sadika; Rutherford, Shannon; Akhter Kumkum, Feroza; Bromwich, David; Anwar, Iqbal; Rahman, Aminur; Chu, Cordia

2017-01-01

Background Traditionally, women in Bangladesh stayed at home in their role as daughter, wife, or mother. In the 1980s, economic reforms created a job market for poor, uneducated rural women in the ready-made garment industry, mostly located in urban areas. This increased participation in paid work has changed the gender roles of these women. Women’s earnings support their family, but they are also separated from their children, with impacts on their mental health and well-being. This study explores the lived experience of women in Bangladesh working in the ready-made garment industry as they strive to be mothers and family providers, often in high-stress conditions. Methods The study was conducted in two industrial areas of Dhaka over 8 months. Data collection included a literature review, 20 in-depth interviews with married female garment workers, and 14 key-informant interviews with officials from the Ministry of Labour and Employment, health-service providers within the garment factories, factory managers, and representatives of the Bangladesh Garment Manufacturers and Exporters Association. The data collected were analyzed thematically. Results Poverty was a key motivating factor for female migrant workers to move from rural areas. Their children stay in their village with their grandparents, because of their mothers’ work conditions and the lack of childcare. The women reported stress, anxiety, restlessness, and thoughts of suicide, due to the double burden of work and separation from their children and family support. Further, they cannot easily access government hospital services due to their long work hours, and the limited medical services provided in the workplace do not meet their needs. Conclusion In order to improve the health and well-being of female garment workers, steps should be taken to develop health interventions to meet the needs of this important group of workers who are contributing significantly to the economic development of the country. PMID:28860866

Work, gender roles, and health: neglected mental health issues among female workers in the ready-made garment industry in Bangladesh.

PubMed

Akhter, Sadika; Rutherford, Shannon; Akhter Kumkum, Feroza; Bromwich, David; Anwar, Iqbal; Rahman, Aminur; Chu, Cordia

2017-01-01

Traditionally, women in Bangladesh stayed at home in their role as daughter, wife, or mother. In the 1980s, economic reforms created a job market for poor, uneducated rural women in the ready-made garment industry, mostly located in urban areas. This increased participation in paid work has changed the gender roles of these women. Women's earnings support their family, but they are also separated from their children, with impacts on their mental health and well-being. This study explores the lived experience of women in Bangladesh working in the ready-made garment industry as they strive to be mothers and family providers, often in high-stress conditions. The study was conducted in two industrial areas of Dhaka over 8 months. Data collection included a literature review, 20 in-depth interviews with married female garment workers, and 14 key-informant interviews with officials from the Ministry of Labour and Employment, health-service providers within the garment factories, factory managers, and representatives of the Bangladesh Garment Manufacturers and Exporters Association. The data collected were analyzed thematically. Poverty was a key motivating factor for female migrant workers to move from rural areas. Their children stay in their village with their grandparents, because of their mothers' work conditions and the lack of childcare. The women reported stress, anxiety, restlessness, and thoughts of suicide, due to the double burden of work and separation from their children and family support. Further, they cannot easily access government hospital services due to their long work hours, and the limited medical services provided in the workplace do not meet their needs. In order to improve the health and well-being of female garment workers, steps should be taken to develop health interventions to meet the needs of this important group of workers who are contributing significantly to the economic development of the country.

The assessment of erythema and thickness on burn related scars during pressure garment therapy as a preventive measure for hypertrophic scarring.

PubMed

Van den Kerckhove, Eric; Stappaerts, Karel; Fieuws, Steffen; Laperre, Jan; Massage, Patrick; Flour, Mieke; Boeckx, Willy

2005-09-01

The aim of this study was threefold: (1) Assess the pressure loss of two types of pressure garments that are used in the treatment of hypertrophic scars after burn injury, (2) investigate the influence of two different levels of compression on erythema and thickness of burn scars and (3) examine the association between erythema and thickness. The study was a prospective trial in which 76 burn scars in 60 patients were objectively assessed with the Minolta Chromameter CR-300 for erythema and with the Dermascan C for thickness of the scar over a period of 3 months. Each patient was randomly assigned to a "normal" or "lower" compression class treatment, with respectively mean values of 15 and 10 mmHg pressure after wearing the garment for 1 month. Measurements for both parameters were taken at 0, 1, 2 and 3 months of treatment. Pressure garments with "normal" compression did lose significantly more compression over 1 month (4.82 mmHg) than did the garments from the low compression class (2.57 mmHg). Scars that were treated with garments from a "normal" compression class did score significantly better for thickness compared to the "low" compression class. The difference in thickness was most evident at 1 month. Thereafter no further significant improvement between the two different treatments over time could be obtained. This difference was not found for erythema. Positive correlations could be found between erythema and thickness values at all of the three test points while changes in erythema and thickness only correlated significantly after the first month. The pattern of change of both parameters correlated at a high level of significance after 3 months of treatment. These data suggest that pressure garments that deliver a pressure of at least 15 mmHg pressure tend to accelerate scar maturation and that measurements of the pattern of change of the erythema can be used to predict changes in scar thickness and vice versa.

Theoretical analysis and experimental investigation on performance of the thermal shield of accelerator cryomodules by thermo-siphon cooling of liquid nitrogen

NASA Astrophysics Data System (ADS)

Datta, T. S.; Kar, S.; Kumar, M.; Choudhury, A.; Chacko, J.; Antony, J.; Babu, S.; Sahu, S. K.

2015-12-01

Five beam line cryomodules with total 27 superconducting Radio Frequency (RF) cavities are installed and commissioned at IUAC to enhance the energy of heavy ion from 15 UD Pelletron. To reduce the heat load at 4.2 K, liquid nitrogen (LN2) cooled intermediate thermal shield is used for all these cryomodules. For three linac cryomodules, concept of forced flow LN2 cooling is used and for superbuncher and rebuncher, thermo-siphon cooling is incorporated. It is noticed that the shield temperature of superbuncher varies from 90 K to 110 K with respect to liquid nitrogen level. The temperature difference can't be explained by using the basic concept of thermo-siphon with the heat load on up flow line. A simple thermo-siphon experimental set up is developed to simulate the thermal shield temperature profile. Mass flow rate of liquid nitrogen is measured with different heat load on up flow line for different liquid levels. It is noticed that small amount of heat load on down flow line have a significant effect on mass flow rate. The present paper will be investigating the data generated from the thermosiphon experimental set up and a theoretical analysis will be presented here to validate the measured temperature profile of the cryomodule shield.

An unusual type of polymorphism in a liquid crystal

DOE PAGES

Li, Lin; Salamonczyk, Miroslaw; Shadpour, Sasan; ...

2018-02-19

Polymorphism is a remarkable concept in chemistry, materials science, computer science, and biology. Whether it is the ability of a material to exist in two or more crystal structures, a single interface connecting to two different entities, or alternative phenotypes of an organism, polymorphism determines function and properties. In materials science, polymorphism can be found in an impressively wide range of materials, including crystalline materials, minerals, metals, alloys, and polymers. Here in this paper we report on polymorphism in a liquid crystal. A bent-core liquid crystal with a single chiral side chain forms two structurally and morphologically significantly different liquidmore » crystal phases solely depending on the cooling rate from the isotropic liquid state. On slow cooling, the thermodynamically more stable oblique columnar phase forms, and on rapid cooling, a not heretofore reported helical microfilament phase. Since structure determines function and properties, the structural color for these phases also differs.« less

An unusual type of polymorphism in a liquid crystal

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

Li, Lin; Salamonczyk, Miroslaw; Shadpour, Sasan

Polymorphism is a remarkable concept in chemistry, materials science, computer science, and biology. Whether it is the ability of a material to exist in two or more crystal structures, a single interface connecting to two different entities, or alternative phenotypes of an organism, polymorphism determines function and properties. In materials science, polymorphism can be found in an impressively wide range of materials, including crystalline materials, minerals, metals, alloys, and polymers. Here in this paper we report on polymorphism in a liquid crystal. A bent-core liquid crystal with a single chiral side chain forms two structurally and morphologically significantly different liquidmore » crystal phases solely depending on the cooling rate from the isotropic liquid state. On slow cooling, the thermodynamically more stable oblique columnar phase forms, and on rapid cooling, a not heretofore reported helical microfilament phase. Since structure determines function and properties, the structural color for these phases also differs.« less

Potential impact of high temperature superconductors on MAGLEV transportation

NASA Astrophysics Data System (ADS)

Hull, J. R.

1992-02-01

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

The influence of a menthol and ethanol soaked garment on human temperature regulation and perception during exercise and rest in warm, humid conditions.

PubMed

Gillis, D Jason; Barwood, M J; Newton, P S; House, J R; Tipton, M J

2016-05-01

This study assessed whether donning a garment saturated with menthol and ethanol (M/E) can improve evaporative cooling and thermal perceptions versus water (W) or nothing (CON) during low intensity exercise and rest in warm, humid conditions often encountered in recreational/occupational settings. It was hypothesised there would be no difference in rectal (Tre) and skin (Tsk) temperature, infra-red thermal imagery of the chest/back, thermal comfort (TC) and rating of perceived exertion (RPE) between M/E, W and CON, but participants would feel cooler in M/E versus W or CON. Six volunteers (mean [SD] 22 [4] years, 72.4 [7.4] kg and 173.6 [3.7] cm) completed (separate days) three, 60-min tests in 30°C, 70%rh, in a balanced order. After 15-min of seated rest participants donned a dry (CON) or 80mL soaked (M/E, W) long sleeve shirt appropriate to their intervention. They then undertook 30-min of low intensity stepping at a rate of 12steps/min on a 22.5cm box, followed by 15-min of seated rest. Measurements included heart rate (HR), Tre, Tsk (chest/back/forearm), thermal imaging (back/chest), thermal sensation (TS), TC and RPE. Data were reported every fifth minute as they changed from baseline and the area under the curves were compared by condition using one-way repeated measures ANOVA, with an alpha level of 0.05. Tre differed by condition, with the largest heat storage response observed in M/E (p<0.05). Skin temperature at the chest/back/forearm, and thermal imaging of the chest all differed by condition, with the greatest rate of heat loss observed in W and M/E respectively (p<0.01). Thermal sensation differed by condition, with the coolest sensations observed in M/E (p<0.001). No other differences were observed. Both M/E and W enhanced evaporative cooling compared CON, but M/E causes cooler sensations and a heat storage response, both of which are likely mediated by menthol. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experimental evidence for a liquid-liquid crossover in deeply cooled confined water.

PubMed

Cupane, Antonio; Fomina, Margarita; Piazza, Irina; Peters, Judith; Schirò, Giorgio

2014-11-21

In this work we investigate, by means of elastic neutron scattering, the pressure dependence of mean square displacements (MSD) of hydrogen atoms of deeply cooled water confined in the pores of a three-dimensional disordered SiO2 xerogel; experiments have been performed at 250 and 210 K from atmospheric pressure to 1200 bar. The "pressure anomaly" of supercooled water (i.e., a mean square displacement increase with increasing pressure) is observed in our sample at both temperatures; however, contrary to previous simulation results and to the experimental trend observed in bulk water, the pressure effect is smaller at lower (210 K) than at higher (250 K) temperature. Elastic neutron scattering results are complemented by differential scanning calorimetry data that put in evidence, besides the glass transition at about 170 K, a first-order-like endothermic transition occurring at about 230 K that, in view of the neutron scattering results, can be attributed to a liquid-liquid crossover. Our results give experimental evidence for the presence, in deeply cooled confined water, of a crossover occurring at about 230 K (at ambient pressure) from a liquid phase predominant at 210 K to another liquid phase predominant at 250 K; therefore, they are fully consistent with the liquid-liquid transition hypothesis.

Armored garment for protecting

DOEpatents

Purvis, James W [Albuquerque, NM; Jones, II, Jack F.; Whinery, Larry D [Albuquerque, NM; Brazfield, Richard [Albuquerque, NM; Lawrie, Catherine [Tijeras, NM; Lawrie, David [Tijeras, NM; Preece, Dale S [Watkins, CO

2009-08-11

A lightweight, armored protective garment for protecting an arm or leg from blast superheated gases, blast overpressure shock, shrapnel, and spall from a explosive device, such as a Rocket Propelled Grenade (RPG) or a roadside Improvised Explosive Device (IED). The garment has a ballistic sleeve made of a ballistic fabric, such as an aramid fiber (e.g., KEVLAR.RTM.) cloth, that prevents thermal burns from the blast superheated gases, while providing some protection from fragments. Additionally, the garment has two or more rigid armor inserts that cover the upper and lower arm and protect against high-velocity projectiles, shrapnel and spall. The rigid inserts can be made of multiple plies of a carbon/epoxy composite laminate. The combination of 6 layers of KEVLAR.RTM. fabric and 28 plies of carbon/epoxy laminate inserts (with the inserts being sandwiched in-between the KEVLAR.RTM. layers), can meet the level IIIA fragmentation minimum V.sub.50 requirements for the US Interceptor Outer Tactical Vest.

Flight test evaluation of an RAF high altitude partial pressure protective assembly

NASA Technical Reports Server (NTRS)

Ashworth, G. R.; Putnam, T. W.; Dana, W. J.; Enevoldson, E. K.; Winter, W. R.

1979-01-01

A partial pressure suit was evaluated during tests in an F-104 and F-15 as a protective garment for emergency descents. The garment is an pressure jerkin and modified anti-g suit combined with an oronasal mask. The garment can be donned and doffed at the aircraft to minimize thermal buildup. The oronasal mask was favored by the pilots due to its immobility on the face during high g-loading. The garment was chosen to provide optimum dexterity for the pilot, which is not available in a full pressure suit, while protecting the pilot at altitudes up to 18,288 meters, during a cabin decompression, and subsequent aircraft descent. During cabin decompressions in the F-104 and F-15, cabin pressure altitude was measured at various aircraft angles of attack, Mach numbers, and altitudes to determine the effect of the aerodynamic slipstream on the cabin altitude.