The Experts below are selected from a list of 18864 Experts worldwide ranked by ideXlab platform
Andrea Kurz - One of the best experts on this subject based on the ideXlab platform.
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effects of a Circulating Water garment and forced air warming on body heat content and core temperature
Anesthesiology, 2004Co-Authors: Akiko Taguchi, D I Sessler, Jebadurai Ratnaraj, Barbara Kabon, Neeru Sharma, Rainer Lenhardt, Andrea KurzAbstract:Background:Forced-air warming is sometimes unable to maintain perioperative normothermia. Therefore, the authors 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 rand
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forced air warming maintains intraoperative normothermia better than Circulating Water mattresses
Anesthesia & Analgesia, 1993Co-Authors: Andrea Kurz, Martin Kurz, Gerald Poeschl, Barbara Faryniak, Gerhard Redl, Werner HacklAbstract:The hypothesis that forced-air warming preserves core temperature better than Circulating-Water mattresses was tested in: (a) 16 adults undergoing major maxillofacial surgery, including radical node resection and flap reconstruction; (b) 53 adults undergoing hip arthroplasty, having approximately 25% of their body surface area available for warming; (c) 20 infants undergoing minor maxillofacial surgery; and (d) 10 young children undergoing pelvic or femoral osteotomies. Patients having each type of surgery were randomly assigned to forced-air warming (approximately 40 degrees C) or conductive warming using a full-length Circulating-Water mattress at 40 degrees C. Forced-air warming was applied to the legs of the adults undergoing maxillofacial surgery and to one arm, the shoulders, and the neck in the adults undergoing hip arthroplasty; a U-shaped, tubular forced-air cover was positioned around the pediatric patients. Core temperatures increased in all patients given forced-air warming and decreased or remained constant in those without active warming. Furthermore, we needed to decrease the temperature of the warmer from high to medium (approximately 37 degrees C) in most patients assigned to forced-air warming to prevent hyperthermia. After 15 h of anesthesia, rectal temperatures in the adults undergoing maxillofacial surgery were 3.4 degrees C higher in the forced-air group (P < 0.01). After 4 h of anesthesia, esophageal temperatures had increased 0.8 +/- 0.5 degrees C in the patients warmed with forced-air and decreased 0.8 +/- 0.3 degrees C in those warmed by Circulating-Water mattresses (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Shaobo Hou - One of the best experts on this subject based on the ideXlab platform.
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An open Reversed Brayton cylce with Regeneration Using Moist Air for Air Conditioning Cooled by Circulating Water
Published by Elsevier B.V., 2011Co-Authors: Shaobo Hou, Shuanshi FanAbstract:AbstractThis paper presents an open reversed Brayton cycle with regeneration (ORBCR) using moist air for air conditioning cooled by Circulating Water, and proves its feasibility through performance simulation. Its refrigeration depends mainly on the sensible heat of air and the latent heat of Water vapor, its performance is more efficient than a conventional air-cycle, and the utilization of turbo-machinery makes it possible. The adoption of this cycle will make air-conditioned room more comfortable and reduce initial cost because of the very low temperature air obtained. The sensitivity analyses of coefficient of performance (COP) of the cycle without regeneration and the equivalent coefficient of performance (COPE) of the cycle with regeneration to the efficiency of compressor (ηc) and the efficiency of compressor (ηt), and the results of both cycles are also given. The simulation results show that the COPE of this system depends mainly on the temperature before turbine (T7),ηc andηt, and varies with the wet bulb temperature of the outdoor air (Twet). Humid air is a perfect working fluid for central air conditioning and no cost to the user. The ORBCR is more efficient because of the use of the return air to cool Water, and then to cool the air before turbine
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an open reversed brayton cycle with regeneration using moist air for deep freeze cooled by Circulating Water
International Journal of Thermal Sciences, 2009Co-Authors: Shaobo Hou, Hefei ZhangAbstract:Abstract This paper presents an open reversed Brayton cycle with regeneration using moist air for deep freeze cooled by Circulating Water, and proves its feasibility through performance simulation. Pinch technology is used to analyze the cooling of the wet air after compressor and the Water used for cooling wet air after compressor. Its refrigeration depends mainly on the sensible heat of air and the latent heat of Water vapor, its performance is more efficient than a conventional air-cycle, and the utilization of turbo-machinery makes it possible. The adoption of this cycle will make deep freeze easily and reduce initial cost because very low temperature, about −55 °C, air is obtained. The sensitivity analysis of coefficient of performance to the efficiency of compressor and the efficiency of compressor, and the results of the cycle are also given. The simulation results show that the COP of this system depends on the temperature before turbine, the efficiency of compressor and the efficiency of compressor, and varies with the wet bulb temperature of the outdoor air. Humid air is a perfect working fluid for deep freeze with no cost to the user.
D I Sessler - One of the best experts on this subject based on the ideXlab platform.
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Circulating Water garment or the combination of a Circulating Water mattress and forced air cover to maintain core temperature during major upper abdominal surgery
BJA: British Journal of Anaesthesia, 2010Co-Authors: Silvia Perezprotto, D I Sessler, L F Reynolds, Mohamed H Bakri, Edward J Mascha, Jacek B Cywinski, Brian M Parker, Maged ArgaliousAbstract:Abstract Background A recent heat-balance study in volunteers suggested that greater efficacy of Circulating-Water garments (CWGs) results largely from increased heat transfer across the posterior skin surface since heat transfer across the anterior skin surface was similar with Circulating-Water and forced-air. We thus tested the hypothesis that the combination of a Circulating-Water mattress (CWM) and forced-air warming prevents core temperature reduction during major abdominal surgery no worse than a CWG does. Methods Fifty adult patients aged between 18 and 85 yr old, undergoing major abdominal surgery, were randomly assigned to intraoperative warming with a combination of forced-air and a CWM or with a CWG (Allon ThermoWrap). Core temperature was measured in the distal oesophagus. Non-inferiority of the CWM to the CWG on change from baseline to median intraoperative temperature was assessed using a one-tailed Student’s t-test with an equivalency buffer of −0.5°C. Results Data analysis was restricted to 16 CWG and 20 CWM patients who completed the protocol. Core temperature increased in both groups during the initial hours of surgery. We had sufficient evidence (P=0.001), to conclude that the combination of a CWM and forced-air warming was non-inferior to a CWG in preventing temperature reduction, with mean (95% CI) difference in the temperature change between the CWM and the CWG groups (CWM−CWG) of 0.46°C (−0.09°C, 1.00°C). Conclusions The combination of a CWM and forced-air warming is significantly non-inferior in maintaining intraoperative core temperature than a CWG. Trial registry: This trial has been registered at clinical trials.gov , identifier: NCT 00651898.
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effects of a Circulating Water garment and forced air warming on body heat content and core temperature
Anesthesiology, 2004Co-Authors: Akiko Taguchi, D I Sessler, Jebadurai Ratnaraj, Barbara Kabon, Neeru Sharma, Rainer Lenhardt, Andrea KurzAbstract:Background:Forced-air warming is sometimes unable to maintain perioperative normothermia. Therefore, the authors 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 rand
Hefei Zhang - One of the best experts on this subject based on the ideXlab platform.
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an open reversed brayton cycle with regeneration using moist air for deep freeze cooled by Circulating Water
International Journal of Thermal Sciences, 2009Co-Authors: Shaobo Hou, Hefei ZhangAbstract:Abstract This paper presents an open reversed Brayton cycle with regeneration using moist air for deep freeze cooled by Circulating Water, and proves its feasibility through performance simulation. Pinch technology is used to analyze the cooling of the wet air after compressor and the Water used for cooling wet air after compressor. Its refrigeration depends mainly on the sensible heat of air and the latent heat of Water vapor, its performance is more efficient than a conventional air-cycle, and the utilization of turbo-machinery makes it possible. The adoption of this cycle will make deep freeze easily and reduce initial cost because very low temperature, about −55 °C, air is obtained. The sensitivity analysis of coefficient of performance to the efficiency of compressor and the efficiency of compressor, and the results of the cycle are also given. The simulation results show that the COP of this system depends on the temperature before turbine, the efficiency of compressor and the efficiency of compressor, and varies with the wet bulb temperature of the outdoor air. Humid air is a perfect working fluid for deep freeze with no cost to the user.
Zohuri Bahman - One of the best experts on this subject based on the ideXlab platform.
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INNOVATIVE OPEN AIR BRAYTON COMBINED CYCLE SYSTEMS FOR THE NEXT GENERATION NUCLEAR POWER PLANTS
2014Co-Authors: Zohuri BahmanAbstract:The purpose of this research was to model and analyze a nuclear heated multi-turbine power conversion system operating with atmospheric air as the working fluid. The air is heated by a molten salt, or liquid metal, to gas heat exchanger reaching a peak temperature of 660 0C. The effects of adding a recuperator or a bottoming steam cycle have been addressed. The calculated results are intended to identify paths for future work on the next generation nuclear power plant (GEN-IV). This document describes the proposed system in sufficient detail to communicate a good understanding of the overall system, its components, and intended uses. The architecture is described at the conceptual level, and does not replace a detailed design document. The main part of the study focused on a Brayton -- Rankine Combined Cycle system and a Recuperated Brayton Cycle since they offer the highest overall efficiencies. Open Air Brayton power cycles also require low cooling Water flows relative to other power cycles. Although the Recuperated Brayton Cycle achieves an overall efficiency slightly less that the Brayton -- Rankine Combined Cycle, it is completely free of a Circulating Water system and can be used in a desert climate. Detailed results of modeling a combined cycle Brayton-Rankine power conversion system are presented. The Rankine bottoming cycle appears to offer a slight efficiency advantage over the recuperated Brayton cycle. Both offer very significant advantages over current generation Light Water Reactor steam cycles. The combined cycle was optimized as a unit and lower pressure Rankine systems seem to be more efficient. The combined cycle requires a lot less Circulating Water than current power plants. The open-air Brayton systems appear to be worth investigating, if the higher temperatures predicted for the Next Generation Nuclear Plant do materialize.Nuclear EngineeringDoctoralUniversity of New Mexico. Dept. of Chemical and Nuclear EngineeringMcDaniel, Patrickde Oliveira, CassianoPrinja, AnilShen, Yu-Li
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INNOVATIVE OPEN AIR BRAYTON COMBINED CYCLE SYSTEMS FOR THE NEXT GENERATION NUCLEAR POWER PLANTS
UNM Digital Repository, 2014Co-Authors: Zohuri BahmanAbstract:The purpose of this research was to model and analyze a nuclear heated multi-turbine power conversion system operating with atmospheric air as the working fluid. The air is heated by a molten salt, or liquid metal, to gas heat exchanger reaching a peak temperature of 660 0C. The effects of adding a recuperator or a bottoming steam cycle have been addressed. The calculated results are intended to identify paths for future work on the next generation nuclear power plant (GEN-IV). This document describes the proposed system in sufficient detail to communicate a good understanding of the overall system, its components, and intended uses. The architecture is described at the conceptual level, and does not replace a detailed design document. The main part of the study focused on a Brayton -- Rankine Combined Cycle system and a Recuperated Brayton Cycle since they offer the highest overall efficiencies. Open Air Brayton power cycles also require low cooling Water flows relative to other power cycles. Although the Recuperated Brayton Cycle achieves an overall efficiency slightly less that the Brayton -- Rankine Combined Cycle, it is completely free of a Circulating Water system and can be used in a desert climate. Detailed results of modeling a combined cycle Brayton-Rankine power conversion system are presented. The Rankine bottoming cycle appears to offer a slight efficiency advantage over the recuperated Brayton cycle. Both offer very significant advantages over current generation Light Water Reactor steam cycles. The combined cycle was optimized as a unit and lower pressure Rankine systems seem to be more efficient. The combined cycle requires a lot less Circulating Water than current power plants. The open-air Brayton systems appear to be worth investigating, if the higher temperatures predicted for the Next Generation Nuclear Plant do materialize