WorldWideScience

Sample records for human 60-kda heat

  1. Home heating & human health

    NARCIS (Netherlands)

    Jongeneel, Sophie

    2008-01-01

    Human health is influenced by pollutants in the air. Since people spend over 80% of their time indoors, indoor air quality may be more related to health problems than outdoor air qual-ity. Indoor air quality is deteriorating because of energy conservation

  2. Heat transfer from humans wearing clothing

    NARCIS (Netherlands)

    Lotens, W.A.

    1993-01-01

    In this monograph the effects of clothing on human heat transfer are described. The description is based on the physics of heat and mass transfer, depending on the design of the clothing, the climate, and the activity of the wearer. The resulting model has been stepwise implemented in computer

  3. Metabolic heat production by human and animal populations in cities

    Science.gov (United States)

    Stewart, Iain D.; Kennedy, Chris A.

    2017-07-01

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai—the world's most densely populated megacity—at 6.5 W m-2, surpassing heat production by electricity use in buildings (5.8 W m-2) and fuel combustion in vehicles (3.9 W m-2). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  4. Exertional Heat Illness and Human Gene Expression

    National Research Council Canada - National Science Library

    Sonna, L.A; Sawka, M. N; Lilly, C. M

    2007-01-01

    Microarray analysis of gene expression at the level of RNA has generated new insights into the relationship between cellular responses to acute heat shock in vitro, exercise, and exertional heat illness...

  5. Metabolic heat production by human and animal populations in cities.

    Science.gov (United States)

    Stewart, Iain D; Kennedy, Chris A

    2017-07-01

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai-the world's most densely populated megacity-at 6.5 W m -2 , surpassing heat production by electricity use in buildings (5.8 W m -2 ) and fuel combustion in vehicles (3.9 W m -2 ). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  6. Temporal trends in human vulnerability to excessive heat

    Science.gov (United States)

    Sheridan, Scott C.; Allen, Michael J.

    2018-04-01

    Over recent decades, studies have examined various morbidity and mortality outcomes associated with heat exposure. This review explores the collective knowledge of the temporal trends of heat on human health, with regard to the hypothesis that humans are less vulnerable to heat events presently than in the past. Using Web of Science and Scopus, the authors identified all peer-reviewed articles that contained keywords on human impact (e.g. mortality, morbidity) and meteorological component (e.g. heat, heatwave). After sorting, a total of 71 articles, both case studies and epidemiological studies, contained explicit assessments of temporal trends in human vulnerability, and thus were used in this review. Most of the studies utilized mortality data, focused on the developed world, and showed a general decrease in heat sensitivity. Factors such as the implementation of a heat warning system, increased awareness, and improved quality of life were cited as contributing factors that led to the decreased impact of heat. Despite the overall recent decreases in heat vulnerability, spatial variability was shown, and differences with respect to health outcomes were also discussed. Several papers noted increases in heat’s impact on human health, particularly when unprecedented conditions occurred. Further, many populations, from outdoor workers to rural residents, in addition to the populations in much of the developing world, have been significantly underrepresented in research to date, and temporal changes in their vulnerability should be assessed in future studies. Moreover, continued monitoring and improvement of heat intervention is needed; with projected changes in the frequency, duration, and intensity of heat events combined with shifts in demographics, heat will remain a major public health issue moving forward.

  7. Slow brushing reduces heat pain in humans.

    Science.gov (United States)

    Liljencrantz, J; Strigo, I; Ellingsen, D M; Krämer, H H; Lundblad, L C; Nagi, S S; Leknes, S; Olausson, H

    2017-08-01

    C-tactile (CT) afferents are unmyelinated low-threshold mechanoreceptors optimized for signalling affective, gentle touch. In three separate psychophysical experiments, we examined the contribution of CT afferents to pain modulation. In total, 44 healthy volunteers experienced heat pain and CT optimal (slow brushing) and CT sub-optimal (fast brushing or vibration) stimuli. Three different experimental paradigms were used: Concurrent application of heat pain and tactile (slow brushing or vibration) stimulation; Slow brushing, applied for variable duration and intervals, preceding heat pain; Slow versus fast brushing preceding heat pain. Slow brushing was effective in reducing pain, whereas fast brushing or vibration was not. The reduction in pain was significant not only when the CT optimal touch was applied simultaneously with the painful stimulus but also when the two stimuli were separated in time. For subsequent stimulation, the pain reduction was more pronounced for a shorter time interval between brushing and pain. Likewise, the effect was more robust when pain was preceded by a longer duration of brush stimulation. Strong CT-related pain reduction was associated with low anxiety and high calmness scores obtained by a state anxiety questionnaire. Slow brushing - optimal for CT activation - is effective in reducing pain from cutaneous heating. The precise mechanisms for the pain relief are as yet unknown but possible mechanisms include inhibition of nociceptive projection neurons at the level of the dorsal horn as well as analgesia through cortical mechanisms. Slow brushing stimuli - optimal for activation of C-tactile fibres - can reduce pain from cutaneous heating. No such effect was seen with fast brushing or vibration. These observations indicate the role of C-tactile fibres in pain modulation. © 2017 European Pain Federation - EFIC®.

  8. Effects of heat stress on baroreflex function in humans

    Science.gov (United States)

    Crandall, Craig G.; Cui, Jian; Wilson, Thad E.

    2003-01-01

    INTRODUCTION: Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function. METHODS: In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non-pharmacological methods. In addition, the effects of heat stress on post-synaptic vasoconstrictor responsiveness were assessed. RESULTS: Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists. CONCLUSION: Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.

  9. Guidelines for the nomenclature of the human heat shock proteins

    NARCIS (Netherlands)

    Kampinga, Harm H.; Hageman, Jurre; Vos, Michel J.; Kubota, Hiroshi; Tanguay, Robert M.; Bruford, Elspeth A.; Cheetham, Michael E.; Chen, B.; Hightower, Lawrence E.

    The expanding number of members in the various human heat shock protein (HSP) families and the inconsistencies in their nomenclature have often led to confusion. Here, we propose new guidelines for the nomenclature of the human HSP families, HSPH (HSP110), HSPC (HSP90), HSPA (HSP70), DNAJ (HSP40),

  10. Optimization study of using PTC for human body heating dissipation

    Directory of Open Access Journals (Sweden)

    Tiberiu Adrian SALAORU

    2014-06-01

    Full Text Available A better knowledge of the human body heat loses mechanisms is important for both diminishing the number of deaths during the surgical procedures of the patients under effect of full anaesthesia and increasing the efficiency of the Heating, Ventilation and Air Conditioning (HVAC systems. For these studies it is necessary to manufacture a human body mannequin having its surface temperature maintained on a value close to the real human body temperature. A number of PTC (Positive Temperature Coefficient thermistors placed on the entire external surface of the mannequin can be used for this purpose. This paper presents a study of the transient heating regime and the stability of the maintained temperature, performed on these devices.

  11. Barcoding heat shock proteins to human diseases : looking beyond the heat shock response

    NARCIS (Netherlands)

    Kakkar, Vaishali; Meister-Broekema, Melanie; Minoia, Melania; Carra, Serena; Kampinga, Harm H.

    There are numerous human diseases that are associated with protein misfolding and the formation of toxic protein aggregates. Activating the heat shock response (HSR) - and thus generally restoring the disturbed protein homeostasis associated with such diseases - has often been suggested as a

  12. Effects of aqueous humor hydrodynamics on human eye heat transfer under external heat sources.

    Science.gov (United States)

    Tiang, Kor L; Ooi, Ean H

    2016-08-01

    The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-dimensional model of the human eye is developed to investigate the effects AH hydrodynamics have on the human eye temperature under exposure to external heat sources. If the effects of AH flow are negligible, then future models can be developed without taking them into account, thus simplifying the modeling process. Two types of external thermal loads are considered; volumetric and surface irradiation. Results showed that heat convection due to AH flow contributes to nearly 95% of the total heat flow inside the anterior chamber. Moreover, the circulation inside the anterior chamber can cause an upward shift of the location of hotspot. This can have significant consequences to our understanding of heat-induced cataractogenesis. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  13. Human thermal physiological and psychological responses under different heating environments.

    Science.gov (United States)

    Wang, Zhaojun; Ning, Haoran; Ji, Yuchen; Hou, Juan; He, Yanan

    2015-08-01

    Anecdotal evidence suggests that many residents of severely cold areas of China who use floor heating (FH) systems feel warmer but drier compared to those using radiant heating (RH) systems. However, this phenomenon has not been verified experimentally. In order to validate the empirical hypothesis, and research the differences of human physiological and psychological responses in these two asymmetrical heating environments, an experiment was designed to mimic FH and RH systems. The subjects participating in the experiment were volunteer college-students. During the experiment, the indoor air temperature, air speed, relative humidity, globe temperature, and inner surface temperatures were measured, and subjects' heart rate, blood pressure and skin temperatures were recorded. The subjects were required to fill in questionnaires about their thermal responses during testing. The results showed that the subjects' skin temperatures, heart rate and blood pressure were significantly affected by the type of heating environment. Ankle temperature had greatest impact on overall thermal comfort relative to other body parts, and a slightly cool FH condition was the most pleasurable environment for sedentary subjects. The overall thermal sensation, comfort and acceptability of FH were higher than that of RH. However, the subjects of FH felt drier than that of RH, although the relative humidity in FH environments was higher than that of the RH environment. In future environmental design, the thermal comfort of the ankles should be scrutinized, and a FH cool condition is recommended as the most comfortable thermal environment for office workers. Consequently, large amounts of heating energy could be saved in this area in the winter. The results of this study may lead to more efficient energy use for office or home heating systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Human Health Science Building Geothermal Heat Pump Systems

    Energy Technology Data Exchange (ETDEWEB)

    Leidel, James [Oakland Univ., Rochester, MI (United States)

    2014-12-22

    The grant objectives of the DOE grant funded project have been successfully completed. The Human Health Building (HHB) was constructed and opened for occupancy for the Fall 2012 semester of Oakland University. As with any large construction project, some issues arose which all were overcome to deliver the project on budget and on time. The facility design is a geothermal / solar-thermal hybrid building utilizing both desiccant dehumidification and variable refrigerant flow heat pumps. It is a cooling dominant building with a 400 ton cooling design day load, and 150 ton heating load on a design day. A 256 vertical borehole (320 ft depth) ground source heat pump array is located south of the building under the existing parking lot. The temperature swing and performance over 2013 through 2015 shows the ground loop is well sized, and may even have excess capacity for a future building to the north (planned lab facility). The HHB achieve a US Green Building Counsel LEED Platinum rating by collecting 52 of the total 69 available LEED points for the New Construction v.2 scoring checklist. Being Oakland's first geothermal project, we were very pleased with the building outcome and performance with the energy consumption approximately 1/2 of the campus average facility, on a square foot basis.

  15. Barcoding heat shock proteins to human diseases: looking beyond the heat shock response.

    Science.gov (United States)

    Kakkar, Vaishali; Meister-Broekema, Melanie; Minoia, Melania; Carra, Serena; Kampinga, Harm H

    2014-04-01

    There are numerous human diseases that are associated with protein misfolding and the formation of toxic protein aggregates. Activating the heat shock response (HSR)--and thus generally restoring the disturbed protein homeostasis associated with such diseases--has often been suggested as a therapeutic strategy. However, most data on activating the HSR or its downstream targets in mouse models of diseases associated with aggregate formation have been rather disappointing. The human chaperonome consists of many more heat shock proteins (HSPs) that are not regulated by the HSR, however, and researchers are now focusing on these as potential therapeutic targets. In this Review, we summarize the existing literature on a set of aggregation diseases and propose that each of them can be characterized or 'barcoded' by a different set of HSPs that can rescue specific types of aggregation. Some of these 'non-canonical' HSPs have demonstrated effectiveness in vivo, in mouse models of protein-aggregation disease. Interestingly, several of these HSPs also cause diseases when mutated--so-called chaperonopathies--which are also discussed in this Review.

  16. Heat shock proteins on the human sperm surface.

    Science.gov (United States)

    Naaby-Hansen, Soren; Herr, John C

    2010-01-01

    The sperm plasma membrane is known to be critical to fertilization and to be highly regionalized into domains of head, mid- and principal pieces. However, the molecular composition of the sperm plasma membrane and its alterations during genital tract passage, capacitation and the acrosome reaction remains to be fully dissected. A two-dimensional gel-based proteomic study previously identified 98 human sperm proteins which were accessible for surface labelling with both biotin and radioiodine. In this report twelve dually labelled protein spots were excised from stained gels or PDVF membranes and analysed by mass spectrometry (MS) and Edman degradation. Seven members from four different heat shock protein (HSP) families were identified including HYOU1 (ORP150), HSPC1 (HSP86), HSPA5 (Bip), HSPD1 (HSP60), and several isoforms of the two testis-specific HSP70 chaperones HSPA2 and HSPA1L. An antiserum raised against the testis-specific HSPA2 chaperone reacted with three 65kDa HSPA2 isoforms and three high molecular weight surface proteins (78-79kDa, 84kDa and 90-93kDa). These proteins, together with seven 65kDa HSP70 forms, reacted with human anti-sperm IgG antibodies that blocked in vitro fertilization in humans. Three of these surface biotinylated human sperm antigens were immunoprecipitated with a rabbit antiserum raised against a linear peptide epitope in Chlamydia trachomatis HSP70. The results indicate diverse HSP chaperones are accessible for surface labelling on human sperm. Some of these share epitopes with C. trachomatis HSP70, suggesting an association between genital tract infection, immunity to HSP70 and reproductive failure. 2009 Elsevier Ireland Ltd. All rights reserved.

  17. Human local and total heat losses in different temperature.

    Science.gov (United States)

    Wang, Lijuan; Yin, Hui; Di, Yuhui; Liu, Yanfeng; Liu, Jiaping

    2016-04-01

    This study investigates the effects of operative temperature on the local and total heat losses, and the relationship between the heat loss and thermal sensation. 10 local parts of head, neck, chest, abdomen, upper arm, forearm, hand, thigh, leg and foot are selected. In all these parts, convection, radiation, evaporation, respiration, conduction and diffusion heat losses are analyzed when operative temperature is 23, 28, 33 and 37 °C. The local heat losses show that the radiation and convection heat losses are mainly affected by the area of local body, and the heat loss of the thigh is the most in the ten parts. The evaporation heat loss is mainly affected by the distribution of sweat gland, and the heat loss of the chest is the most. The total heat loss of the local body shows that in low temperature, the thigh, leg and chest have much heat loss, while in high temperature, the chest, abdomen, thigh and head have great heat loss, which are useful for clothing design. The heat losses of the whole body show that as the operative temperature increases, the radiation and convection heat losses decrease, the heat losses of conduction, respiration, and diffusion are almost constant, and the evaporation heat loss increases. By comparison, the heat loss ratios of the radiation, convection and sweat evaporation, are in agreement with the previous researches. At last, the formula about the heat loss ratio of convection and radiation is derived. It's useful for thermal comfort evaluation and HVAC (heating, ventilation and air conditioning) design. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Neural correlates of heat-evoked pain memory in humans.

    Science.gov (United States)

    Wang, Liping; Gui, Peng; Li, Lei; Ku, Yixuan; Bodner, Mark; Fan, Gaojie; Zhou, Yong-Di; Dong, Xiao-Wei

    2016-03-01

    The neural processes underlying pain memory are not well understood. To explore these processes, contact heat-evoked potentials (CHEPs) were recorded in humans with electroencephalography (EEG) technique during a delayed matching-to-sample task, a working memory task involving presentations of two successive painful heat stimuli (S-1 and S-2) with different intensities separated by a 2-s interval (the memorization period). At the end of the task, the subject was required to discriminate the stimuli by indicating which (S-1 or S-2) induced more pain. A control task was used, in which no active discrimination was required between stimuli. All event-related potential (ERP) analysis was aligned to the onset of S-1. EEG activity exhibited two successive CHEPs: an N2-P2 complex (∼400 ms after onset of S-1) and an ultralate component (ULC, ∼900 ms). The amplitude of the N2-P2 at vertex, but not the ULC, was significantly correlated with stimulus intensity in these two tasks, suggesting that the N2-P2 represents neural coding of pain intensity. A late negative component (LNC) in the frontal recording region was observed only in the memory task during a 500-ms period before onset of S-2. LNC amplitude differed between stimulus intensities and exhibited significant correlations with the N2-P2 complex. These indicate that the frontal LNC is involved in maintenance of intensity of pain in working memory. Furthermore, alpha-band oscillations observed in parietal recording regions during the late delay displayed significant power differences between tasks. This study provides in the temporal domain previously unidentified neural evidence showing the neural processes involved in working memory of painful stimuli. Copyright © 2016 the American Physiological Society.

  19. Heat effects on drug delivery across human skin

    Science.gov (United States)

    Hao, Jinsong; Ghosh, Priyanka; Li, S. Kevin; Newman, Bryan; Kasting, Gerald B.; Raney, Sam G.

    2016-01-01

    Introduction Exposure to heat can impact the clinical efficacy and/or safety of transdermal and topical drug products. Understanding these heat effects and designing meaningful in vitro and in vivo methods to study them are of significant value to the development and evaluation of drug products dosed to the skin. Areas covered This review provides an overview of the underlying mechanisms and the observed effects of heat on the skin and on transdermal/topical drug delivery, thermoregulation and heat tolerability. The designs of several in vitro and in vivo heat effect studies and their results are reviewed. Expert opinion There is substantial evidence that elevated temperature can increase transdermal/topical drug delivery. However, in vitro and in vivo methods reported in the literature to study heat effects of transdermal/topical drug products have utilized inconsistent study conditions, and in vitro models require better characterization. Appropriate study designs and controls remain to be identified, and further research is warranted to evaluate in vitro-in vivo correlations and the ability of in vitro models to predict in vivo effects. The physicochemical and pharmacological properties of the drug(s) and the drug product, as well as dermal clearance and heat gradients may require careful consideration. PMID:26808472

  20. The urban heat island and its impact on heat waves and human health in Shanghai.

    Science.gov (United States)

    Tan, Jianguo; Zheng, Youfei; Tang, Xu; Guo, Changyi; Li, Liping; Song, Guixiang; Zhen, Xinrong; Yuan, Dong; Kalkstein, Adam J; Li, Furong

    2010-01-01

    With global warming forecast to continue into the foreseeable future, heat waves are very likely to increase in both frequency and intensity. In urban regions, these future heat waves will be exacerbated by the urban heat island effect, and will have the potential to negatively influence the health and welfare of urban residents. In order to investigate the health effects of the urban heat island (UHI) in Shanghai, China, 30 years of meteorological records (1975-2004) were examined for 11 first- and second-order weather stations in and around Shanghai. Additionally, automatic weather observation data recorded in recent years as well as daily all-cause summer mortality counts in 11 urban, suburban, and exurban regions (1998-2004) in Shanghai have been used. The results show that different sites (city center or surroundings) have experienced different degrees of warming as a result of increasing urbanization. In turn, this has resulted in a more extensive urban heat island effect, causing additional hot days and heat waves in urban regions compared to rural locales. An examination of summer mortality rates in and around Shanghai yields heightened heat-related mortality in urban regions, and we conclude that the UHI is directly responsible, acting to worsen the adverse health effects from exposure to extreme thermal conditions.

  1. Heat balance model for a human body in the form of wet bulb globe temperature indices.

    Science.gov (United States)

    Sakoi, Tomonori; Mochida, Tohru; Kurazumi, Yoshihito; Kuwabara, Kohei; Horiba, Yosuke; Sawada, Shin-Ichi

    2018-01-01

    The purpose of this study is to expand the empirically derived wet bulb globe temperature (WBGT) index to a rational thermal index based on the heat balance for a human body. We derive the heat balance model in the same form as the WBGT for a human engaged in moderate intensity work with a metabolic heat production of 174W/m 2 while wearing typical vapor-permeable clothing under shady and sunny conditions. Two important relationships are revealed based on this derivation: (1) the natural wet bulb and black globe temperature coefficients in the WBGT coincide with the heat balance equation for a human body with a fixed skin wettedness of approximately 0.45 at a fixed skin temperature; and (2) the WBGT can be interpreted as the environmental potential to increase skin temperature rather than the heat storage rate of a human body. We propose an adjustment factor calculation method that supports the application of WBGT for humans dressed in various clothing types and working under various air velocity conditions. Concurrently, we note difficulties in adjusting the WBGT by using a single factor for humans wearing vapor-impermeable protective clothing. The WBGT for shady conditions does not need adjustment depending on the positive radiant field (i.e., when a radiant heat source exists), whereas that for the sunny condition requires adjustments because it underestimates heat stress, which may result in insufficient human protection measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Can intradermal administration of angiotensin II influence human heat loss responses during whole body heat stress?

    Science.gov (United States)

    Fujii, Naoto; Meade, Robert D; Paull, Gabrielle; McGinn, Ryan; Foudil-bey, Imane; Akbari, Pegah; Kenny, Glen P

    2015-05-01

    It is unclear if angiotensin II, which can increase the production of reactive oxygen species (oxidative stress), modulates heat loss responses of cutaneous blood flow and sweating. We tested the hypothesis that angiotensin II-induced increases in oxidative stress impair cutaneous perfusion and sweating during rest and exercise in the heat. Eleven young (24 ± 4 yr) healthy adults performed two 30-min cycling bouts at a fixed rate of metabolic heat production (400 W) in the heat (35°C). The first and second exercises were followed by a 20- and 40-min recovery. Four microdialysis fibers were placed in the forearm skin for continuous administration of either: 1) lactated Ringer (control), 2) 10 μM angiotensin II, 3) 10 mM ascorbate (an antioxidant), or 4) a combination of 10 μM angiotensin II + 10 mM ascorbate. Cutaneous vascular conductance (CVC; laser-Doppler perfusion units/mean arterial pressure) and sweating (ventilated capsule) were evaluated at each skin site. Compared with control, angiotensin II reduced both CVC and sweating at baseline resting and during each recovery in the heat (all P 0.05). When ascorbate was coinfused with angiotensin II, the effect of angiotensin II on sweating was abolished (all P > 0.05); however, its effect on CVC at baseline resting and during each recovery remained intact (all P stress, while it impairs sweating through increasing oxidative stress during exposure to an ambient heat stress before and following exercise. Copyright © 2015 the American Physiological Society.

  3. Effect of heat treatment at 600 degree C for 10 hours on human BMP

    International Nuclear Information System (INIS)

    Izawa, H.; Hachiya, Y.; Muramatsu, K.; Narita, Y.; Kawai, T.

    1999-01-01

    Viral infection are an extremely serious in allogeneic bone transplantations. While it is essential to kill viruses such as HIV in allogeneic bone graft, the osteoinductive activity must be preserved. Heat treatment of allogeneic bone graft at 60 degree C for 10 hours is effective in killing viruses such as HIV, but it is unclear to what extent the activity of human bone morphogenetic protein (hBMP) is preserved. In this experiment crude hBMP was extracted from both heated and non-heated human bones which were decalcified by the Urist method. Gelatin capsules containing 5mg of crude hBMP were transplanted into the thigh muscles of 5 week old mice. Human bone samples heated in a water bath at 60 degree C for 10 hours and non-heated samples were each transplanted into 5 mice. At 20 days after transplantation, the heterotopic bone formation was compared by evaluation of X-ray and histologicic analysis. X-rays showed heterotopic bone formation in both heated and non-heated samples. Further, histologic analysis showed that peripheral osteoid tissue had developed into laminar bone formation and interlaminar bone marrow was observed. Heterotopic bone formation was induced by crude hBMP from heated bones in a similar way to crude hBMP from non-heated bones observed in X-ray. There was no significant difference in histologic analysis. The crude hBMP, extracted from bones which were heat-treated at 60 degree C for 10 hours induced heterotopic bone formation similar to that in non-heated bone observed by X-ray and histologic analysis at 20 days after transplantation. This demostrates that the heat-treated bone preserved osteoinduction

  4. Acute volume expansion preserves orthostatic tolerance during whole-body heat stress in humans.

    Science.gov (United States)

    Keller, David M; Low, David A; Wingo, Jonathan E; Brothers, R Matthew; Hastings, Jeff; Davis, Scott L; Crandall, Craig G

    2009-03-01

    Whole-body heat stress reduces orthostatic tolerance via a yet to be identified mechanism(s). The reduction in central blood volume that accompanies heat stress may contribute to this phenomenon. The purpose of this study was to test the hypothesis that acute volume expansion prior to the application of an orthostatic challenge attenuates heat stress-induced reductions in orthostatic tolerance. In seven normotensive subjects (age, 40 +/- 10 years: mean +/- S.D.), orthostatic tolerance was assessed using graded lower-body negative pressure (LBNP) until the onset of symptoms associated with ensuing syncope. Orthostatic tolerance (expressed in cumulative stress index units, CSI) was determined on each of 3 days, with each day having a unique experimental condition: normothermia, whole-body heating, and whole-body heating + acute volume expansion. For the whole-body heating + acute volume expansion experimental day, dextran 40 was rapidly infused prior to LBNP sufficient to return central venous pressure to pre-heat stress values. Whole-body heat stress alone reduced orthostatic tolerance by approximately 80% compared to normothermia (938 +/- 152 versus 182 +/- 57 CSI; mean +/- S.E.M., P body heating completely ameliorated the heat stress-induced reduction in orthostatic tolerance (1110 +/- 69 CSI, P stress results in many cardiovascular and neural responses that directionally challenge blood pressure regulation, reduced central blood volume appears to be an underlying mechanism responsible for impaired orthostatic tolerance in the heat-stressed human.

  5. Calorimetric study on human erythrocyte glycolysis. Heat production in various metabolic conditions.

    Science.gov (United States)

    Minakami, S; de Verdier, C H

    1976-06-01

    The heat production of human erythrocytes was measured on a flow microcalorimeter with simultaneous analyses of lactate and other metabolites. The heat production connected with the lactate formation was about 17 kcal (71 kJ) per mol lactate formed which corresponded to the sum of heat production due to the formation of lactate from glucose and the heat production due to neutralization. The heat production rate increased as the pH of the suspension increased, corresponding to the increase in lactate formation. Glycolytic inhibitors such as fluoride and monoiodoacetate caused a decrease in the rate of heat production, whereas arsenate induced a large transient increase in heat production associated with a transient increase in lactate formation. Decrease in pyruvate concentration was usually associated with increase in heat production, although the decreased pyruvate concentration was coupled with formation of 2,3-bisphosphoglycerate. When inosine, dihydroxyacetone or D-glyceraldehyde was used as a substrate, an increase in the heat production rate was observed. Addition of methylene blue caused an oxygen uptake which was accompanied by a remarkable increase in heat production rate corresponding to about 160 kcal (670 kJ) per mol oxygen consumed. The value for heat production in red cells in the above-mentioned metabolic conditions was considered in relation to earlier known data on free energy and enthalpy changes of the different metabolic steps in the glycolytic pathway.

  6. Molecular mechanisms of anti-aging hormetic effects of mild heat stress on human cells

    DEFF Research Database (Denmark)

    Rattan, Suresh I S; Eskildsen-Helmond, Yvonne E G; Beedholm, Rasmus

    2004-01-01

    of cellular responsiveness to mild and severe heat stress. Furthermore, we are also undertaking comparative studies using non-aging immortal cell lines, such as SV40-transformed human fibroblasts, spontaneous osteosarcoma cells, and telomerase-immortalized human bone marrow cells for establishing differences...

  7. A contrastive analysis of laser heating between the human and guinea pig cochlea by numerical simulations.

    Science.gov (United States)

    Zhang, Kaiyin; Zhang, Yulong; Li, Ji; Wang, Qiuling

    2016-05-23

    The photo-thermal effect has been hypothesised to be one of the most possible biophysical mechanisms for laser-cochlea stimulation. However, there is a lack of studies to date for direct assessing laser heating in humans due to the large body of evidence required to demonstrate safety and efficacy. Instead, the majority focus on animals like the guinea pig, from which a number of valuable results have been gained. However, in light of the increasing need to improve laser safety, it has became necessary to find out whether studies on animals can shed light on safe laser parameters in the human cochlea. Hence, we conducted this contrastive analysis of laser heating between the human and guinea pig cochlea with the aim of assisting further investigations in this field. In this work, a 3D symmetrical model was adopted to simplify the spiraled cochlea. With attention focused on the effect of heat conduction, the time-dependent heat equation was solved using finite element method with the COMSOL Script. In the simulations, cochleae with different sizes and various boundary thermal conditions were utilized. Laser heating in both cochleae has a similar trend. In the first stage, or at the beginning of the laser heating, both cochleae increased their temperatures rapidly. In the second stage in which the laser heating reached a quasi-steady stage, the peak temperatures began to rise slowly as more laser pulses were applied. However, three differences of the laser heating were observed. The first is regarding the temperature rise. The results show that laser heating in guinea pig is higher than that in human under the same laser parameters. The second difference is the fluctuation of temperature rise at the center of the modiolus. There is a larger fluctuation of temperature rise in the guinea pig cochlea, compared with that in the human cochlea. The third one is the time for reaching a steady thermal state. The results show that the guinea pig cochlea takes longer time to

  8. Estimation and harvesting of human heat power for wearable electronic devices

    International Nuclear Information System (INIS)

    Dziurdzia, P; Brzozowski, I; Bratek, P; Gelmuda, W; Kos, A

    2016-01-01

    The paper deals with the issue of self-powered wearable electronic devices that are capable of harvesting free available energy dissipated by the user in the form of human heat. The free energy source is intended to be used as a secondary power source supporting primary battery in a sensor bracelet. The main scope of the article is a presentation of the concept for a measuring setup used to quantitative estimation of heat power sources in different locations over the human body area. The crucial role in the measurements of the human heat plays a thermoelectric module working in the open circuit mode. The results obtained during practical tests are confronted with the requirements of the dedicated thermoelectric generator. A prototype design of a human warmth energy harvester with an ultra-low power DC-DC converter based on the LTC3108 circuit is analysed

  9. Tumor necrosis factor alpha selectively sensitizes human immunodeficiency virus-infected cells to heat and radiation

    International Nuclear Information System (INIS)

    Wong, G.H.; McHugh, T.; Weber, R.; Goeddel, D.V.

    1991-01-01

    We report here that infection of the human T-cell line HUT-78 with human immunodeficiency virus (HIV) increases its sensitivity to heat and radiation toxicity. A possible explanation for this result may be the reduced expression of manganous superoxide dismutase (MnSOD) in HIV-infected cells compared to uninfected cells. Tumor necrosis factor alpha (TNF-alpha) further sensitizes HIV-infected cells but not uninfected cells to heat and radiation. This is consistent with the ability of TNF-alpha to induce the expression of MnSOD in uninfected but not in HIV-infected cells. HIV-infected HUT-78 cell lines engineered to overexpress MnSOD are more resistant to heat and radiation than HIV-infected cells that do not overexpress MnSOD. However, treatment with TNF-alpha still sensitizes these cells to heat and radiation

  10. Humans as a Source of Heat and Air Pollution

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    This is the first part of a planned research into the effect of the human being on the indoor climate. The results are among other things intended for CFD calculations. This part deals with the influence from breathing, smoking, bioeffluents and vapour. The results are mainly based on measurement...

  11. Fetal calf serum heat inactivation and lipopolysaccharide contamination influence the human T lymphoblast proteome and phosphoproteome

    Directory of Open Access Journals (Sweden)

    Rahman Hazir

    2011-11-01

    Full Text Available Abstract Background The effects of fetal calf serum (FCS heat inactivation and bacterial lipopolysaccharide (LPS contamination on cell physiology have been studied, but their effect on the proteome of cultured cells has yet to be described. This study was undertaken to investigate the effects of heat inactivation of FCS and LPS contamination on the human T lymphoblast proteome. Human T lymphoblastic leukaemia (CCRF-CEM cells were grown in FCS, either non-heated, or heat inactivated, having low ( Results A total of four proteins (EIF3M, PRS7, PSB4, and SNAPA were up-regulated when CCRF-CEM cells were grown in media supplemented with heat inactivated FCS (HE as compared to cells grown in media with non-heated FCS (NHE. Six proteins (TCPD, ACTA, NACA, TCTP, ACTB, and ICLN displayed a differential phosphorylation pattern between the NHE and HE groups. Compared to the low concentration LPS group, regular levels of LPS resulted in the up-regulation of three proteins (SYBF, QCR1, and SUCB1. Conclusion The present study provides new information regarding the effect of FCS heat inactivation and change in FCS-LPS concentration on cellular protein expression, and post-translational modification in human T lymphoblasts. Both heat inactivation and LPS contamination of FCS were shown to modulate the expression and phosphorylation of proteins involved in basic cellular functions, such as protein synthesis, cytoskeleton stability, oxidative stress regulation and apoptosis. Hence, the study emphasizes the need to consider both heat inactivation and LPS contamination of FCS as factors that can influence the T lymphoblast proteome.

  12. Muscular heat and mechanical pain sensitivity after lengthening contractions in humans and animals.

    Science.gov (United States)

    Queme, Fernando; Taguchi, Toru; Mizumura, Kazue; Graven-Nielsen, Thomas

    2013-11-01

    Mechanical sensitivity of muscle nociceptors was previously shown to increase 2 days after lengthening contractions (LC), but heat sensitivity was not different despite nerve growth factor (NGF) being upregulated in the muscle during delayed-onset muscle soreness (DOMS). The discrepancy of these results and lack of other reports drove us to assess heat sensitivity during DOMS in humans and to evaluate the effect of NGF on the heat response of muscle C-fibers. Pressure pain thresholds and pain intensity scores to intramuscular injection of isotonic saline at 48°C and capsaicin were recorded in humans after inducing DOMS. The response of single unmyelinated afferents to mechanical and heat stimulations applied to their receptive field was recorded from muscle-nerve preparations in vitro. In humans, pressure pain thresholds were reduced but heat and capsaicin pain responses were not increased during DOMS. In rats, the mechanical but not the heat sensitivity of muscle C-fibers was increased in the LC group. NGF applied to the receptive field facilitated the heat sensitivity relative to the control. The absence of facilitated heat sensitivity after LC, despite the NGF sensitization, may be explained if the NGF concentration produced after LC is not sufficient to sensitize nociceptor response to heat. This article presents new findings on the basic mechanisms underlying hyperalgesia during DOMS, which is a useful model to study myofascial pain syndrome, and the role of NGF on muscular nociception. This might be useful in the search for new pharmacologic targets and therapeutic approaches. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  13. Effect of short-term exercise-heat acclimation on ventilatory and cerebral blood flow responses to passive heating at rest in humans.

    Science.gov (United States)

    Fujii, Naoto; Tsuji, Bun; Honda, Yasushi; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-09-01

    Hyperthermia induces hyperventilation and cerebral hypoperfusion in resting humans. We tested the hypothesis that short-term exercise-heat acclimation would alleviate those effects. Twenty healthy male subjects were divided into two groups that performed exercise training in the heat (TR-HEAT, n = 10) or cold (TR-COLD, n = 10). Before and after the training, the subjects in both groups participated in passive-heat tests at rest. Training was performed at 37°C (TR-HEAT) or 10°C (TR-COLD) and entailed four 20-min bouts of cycling at 50% peak oxygen uptake separated by 10-min recoveries daily for 6 consecutive days. After TR-HEAT, esophageal temperature was lowered when measured before and during passive heating, as was the esophageal temperature threshold for cutaneous active vasodilation, whereas plasma volume was increased (all P heat acclimation were not all induced by TR-COLD (all P > 0.05). TR-HEAT had no significant effect on passive heating-induced increases in minute ventilation, even when evaluated as the esophageal temperature threshold for increases in minute ventilation and the slope relating minute ventilation to esophageal temperature (all P > 0.05). By contrast, TR-HEAT attenuated the passive heating-induced reduction in the cerebral vascular conductance index (middle cerebral artery mean blood velocity/mean arterial pressure) (all P heating (all P > 0.05). These data suggest that in resting heated humans, short-term heat acclimation achieved through moderate-intensity exercise training (i.e., 50% peak oxygen uptake) in the heat does not influence hyperthermia-induced hyperventilation, but it does potentially attenuate cerebral hypoperfusion. Copyright © 2015 the American Physiological Society.

  14. The human heat balance in the city of Novi Sad (Serbia

    Directory of Open Access Journals (Sweden)

    Krajić Aleksandar

    2012-01-01

    Full Text Available This analysis is based on the human heat balance according to the bioclimatic man-environment heat exchange model created by Krzysztof Błażejczyk. The final result of the human heat balance model points to biothermal weather situations for the outdoor recreational needs. In this analysis, middles daily meteorological data (of climatological station of Novi Sad were used for two extreme months, January and July. In this work, it is analyzed two periods, the first is for 1992-2010. and the second is for year 2010. The aim is to show how weather can be evaluated for recreational needs which the health resource of Novi Sad and to point out the shortcomings when it comes to multi-year analysis. The objective of this article has been to present a bioclimatic analysis of city Novi Sad and how weather variables come together in order to give a climate meaning on human organism.

  15. Heat Exchange in “Human body - Thermal protection - Environment” System

    Science.gov (United States)

    Khromova, I. V.

    2017-11-01

    This article is devoted to the issues of simulation and calculation of thermal processes in the system called “Human body - Thermal protection - Environment” under low temperature conditions. It considers internal heat sources and convective heat transfer between calculated elements. Overall this is important for the Heat Transfer Theory. The article introduces complex heat transfer calculation method and local thermophysical parameters calculation method in the system called «Human body - Thermal protection - Environment», considering passive and active thermal protections, thermophysical and geometric properties of calculated elements in a wide range of environmental parameters (water, air). It also includes research on the influence that thermal resistance of modern materials, used in special protective clothes development, has on heat transfer in the system “Human body - Thermal protection - Environment”. Analysis of the obtained results allows adding of the computer research data to experiments and optimizing of individual life-support system elements, which are intended to protect human body from exposure to external factors.

  16. Peripheral and central components of habituation of heat pain perception and evoked potentials in humans.

    Science.gov (United States)

    Greffrath, Wolfgang; Baumgärtner, Ulf; Treede, Rolf-Detlef

    2007-12-05

    For the neurophysiological examination of nociceptive pathways, contact-heat evoked potentials (contact-heat EPs) are elicited by repetitive brief noxious heat stimuli. Suppression of heat responses in primary nociceptive neurons during repetitive stimulation has been shown in animal models in vivo and in vitro. We now investigated whether heat pain and contact-heat EPs in humans display equivalent signs of habituation. Heat pain and EPs were elicited in 16 volunteers with a contact thermode (30 degrees Cs(-1)). Heat pulses at three intensities (pain threshold, moderate noxious and maximum available) were applied to the right forearm either by moving the thermode after each pulse to variable locations or when fixed to one location (inter-stimulus intervals 8-10s). Contact-heat EPs consisted of an early negativity in temporal leads (N1), followed by a biphasic response at the vertex (N2-P2). Pain ratings and contact-heat EPs (N1 and N2-P2 components) displayed significant temperature dependence. N2-P2 correlated positively with ratings. With stimulation at variable locations, both measures slowly decreased with time constants tau of 2 min (ratings) and 12 min (EPs). With stimulation at a fixed location, habituation was much faster for both, ratings (tau=10s) and EPs (tau=33 s). As a consequence, both measures were significantly reduced (pheat pain perception and contact-heat EPs display signs of rapid habituation when stimulation is restricted to a fixed location and thus, reflect fatigue of peripheral nociceptive neurons. Habituation within the central nervous system is slower and less pronounced.

  17. Thermoreceptive innervation of human glabrous and hairy skin: a contact heat evoked potential analysis.

    Science.gov (United States)

    Granovsky, Yelena; Matre, Dagfinn; Sokolik, Alexander; Lorenz, Jürgen; Casey, Kenneth L

    2005-06-01

    The human palm has a lower heat detection threshold and a higher heat pain threshold than hairy skin. Neurophysiological studies of monkeys suggest that glabrous skin has fewer low threshold heat nociceptors (AMH type 2) than hairy skin. Accordingly, we used a temperature-controlled contact heat evoked potential (CHEP) stimulator to excite selectively heat receptors with C fibers or Adelta-innervated AMH type 2 receptors in humans. On the dorsal hand, 51 degrees C stimulation produced painful pinprick sensations and 41 degrees C stimuli evoked warmth. On the glabrous thenar, 41 degrees C stimulation produced mild warmth and 51 degrees C evoked strong but painless heat sensations. We used CHEP responses to estimate the conduction velocities (CV) of peripheral fibers mediating these sensations. On hairy skin, 41 degrees C stimuli evoked an ultra-late potential (mean, SD; N wave latency: 455 (118) ms) mediated by C fibers (CV by regression analysis: 1.28 m/s, N=15) whereas 51 degrees C stimuli evoked a late potential (N latency: 267 (33) ms) mediated by Adelta afferents (CV by within-subject analysis: 12.9 m/s, N=6). In contrast, thenar responses to 41 and 51 degrees C were mediated by C fibers (average N wave latencies 485 (100) and 433 (73) ms, respectively; CVs 0.95-1.35 m/s by regression analysis, N=15; average CV=1.7 (0.41) m/s calculated from distal glabrous and proximal hairy skin stimulation, N=6). The exploratory range of the human and monkey palm is enhanced by the abundance of low threshold, C-innervated heat receptors and the paucity of low threshold AMH type 2 heat nociceptors.

  18. Human Thermal Comfort and Heat Stress in an Outdoor Urban Arid Environment: A Case Study

    Directory of Open Access Journals (Sweden)

    A. M. Abdel-Ghany

    2013-01-01

    Full Text Available To protect humans from heat stress risks, thermal comfort and heat stress potential were evaluated under arid environment, which had never been made for such climate. The thermal indices THI, WBGT, PET, and UTCI were used to evaluate thermal comfort and heat stress. RayMan software model was used to estimate the PET, and the UTCI calculator was used for UTCI. Dry and wet bulb temperatures (Td, Tw, natural wet bulb temperature (Tnw, and globe temperature (Tg were measured in a summer day to be used in the calculation. The results showed the following. (i The thermal sensation and heat stress levels can be evaluated by either the PET or UTCI scales, and both are valid for extremely high temperature in the arid environment. (ii In the comfort zone, around 75% of individuals would be satisfied with the surrounding environment and feel comfortable during the whole day. (iii Persons are exposed to strong heat stress and would feel uncomfortable most of the daytime in summer. (iv Heat fatigue is expected with prolonged exposure to sun light and activity. (v During the daytime, humans should schedule their activities according to the highest permissible values of the WBGT to avoid thermal shock.

  19. Effect of a patent foramen ovale in humans on thermal responses to passive cooling and heating.

    Science.gov (United States)

    Davis, James T; Hay, Madeline W; Hardin, Alyssa M; White, Matthew D; Lovering, Andrew T

    2017-12-01

    Humans with a patent foramen ovale (PFO) have a higher esophageal temperature (T esoph ) than humans without a PFO (PFO-). Thus the presence of a PFO might also be associated with differences in thermal responsiveness to passive cooling and heating such as shivering and hyperpnea, respectively. The purpose of this study was to determine whether thermal responses to passive cooling and heating are different between PFO- subjects and subjects with a PFO (PFO+). We hypothesized that compared with PFO- subjects PFO+ subjects would cool down more rapidly and heat up slower and that PFO+ subjects who experienced thermal hyperpnea would have a blunted increase in ventilation. Twenty-seven men (13 PFO+) completed two trials separated by >48 h: 1 ) 60 min of cold water immersion (19.5 ± 0.9°C) and 2 ) 30 min of hot water immersion (40.5 ± 0.2°C). PFO+ subjects had a higher T esoph before and during cold water and hot water immersion ( P heating. NEW & NOTEWORTHY Patent foramen ovale (PFO) is found in ~25-40% of the population. The presence of a PFO appears to be associated with a greater core body temperature and blunted ventilatory responses during passive heating. The reason for this blunted ventilatory response to passive heating is unknown but may suggest differences in thermal sensitivity in PFO+ subjects compared with PFO- subjects. Copyright © 2017 the American Physiological Society.

  20. Induction of Heat Shock Protein Expression in Cervical Epithelial Cells by Human Semen

    Directory of Open Access Journals (Sweden)

    J. C. Jeremias

    1999-01-01

    Full Text Available Objective: The 70kD heat shock protein (Hsp70, induced when cells are subjected to environmental stress, prevents the denaturation and incorrect folding of polypeptides and may expedite replication and transmission of DNA and RNA viruses. We analyzed whether messenger RNA (mRNA for Hsp70 was expressed following exposure of a cultured human cervical cell line (HeLa cells to human semen or in cervical cells from sexually active women.

  1. Modelling flow and heat transfer around a seated human body by computational fluid dynamics

    DEFF Research Database (Denmark)

    Sørensen, Dan Nørtoft; Voigt, Lars Peter Kølgaard

    2003-01-01

    A database (http://www.ie.dtu.dk/manikin) containing a detailed representation of the surface geometry of a seated female human body was created from a surface scan of a thermal manikin (minus clothing and hair). The radiative heat transfer coefficient and the natural convection flow around...... of the computational manikin has all surface features of a human being; (2) the geometry is an exact copy of an experimental thermal manikin, enabling detailed comparisons between calculations and experiments....

  2. Phenylephrine-induced elevations in arterial blood pressure are attenuated in heat-stressed humans

    Science.gov (United States)

    Cui, Jian; Wilson, Thad E.; Crandall, Craig G.

    2002-01-01

    To test the hypothesis that phenylephrine-induced elevations in blood pressure are attenuated in heat-stressed humans, blood pressure was elevated via steady-state infusion of three doses of phenylephrine HCl in 10 healthy subjects in both normothermic and heat stress conditions. Whole body heating significantly increased sublingual temperature by 0.5 degrees C, muscle sympathetic nerve activity (MSNA), heart rate, and cardiac output and decreased total peripheral vascular resistance (TPR; all P blood pressure (MAP; P > 0.05). At the highest dose of phenylephrine, the increase in MAP and TPR from predrug baselines was significantly attenuated during the heat stress [DeltaMAP 8.4 +/- 1.2 mmHg; DeltaTPR 0.96 +/- 0.85 peripheral resistance units (PRU)] compared with normothermia (DeltaMAP 15.4 +/- 1.4 mmHg, DeltaTPR 7.13 +/- 1.18 PRU; all P blood pressure, as well as the slope of the relationship between heart rate and systolic blood pressure, respectively, was similar between thermal conditions (each P > 0.05). These data suggest that phenylephrine-induced elevations in MAP are attenuated in heat-stressed humans without affecting baroreflex control of MSNA or heart rate.

  3. Skin cooling maintains cerebral blood flow velocity and orthostatic tolerance during tilting in heated humans

    Science.gov (United States)

    Wilson, Thad E.; Cui, Jian; Zhang, Rong; Witkowski, Sarah; Crandall, Craig G.

    2002-01-01

    Orthostatic tolerance is reduced in the heat-stressed human. The purpose of this project was to identify whether skin-surface cooling improves orthostatic tolerance. Nine subjects were exposed to 10 min of 60 degrees head-up tilting in each of four conditions: normothermia (NT-tilt), heat stress (HT-tilt), normothermia plus skin-surface cooling 1 min before and throughout tilting (NT-tilt(cool)), and heat stress plus skin-surface cooling 1 min before and throughout tilting (HT-tilt(cool)). Heating and cooling were accomplished by perfusing 46 and 15 degrees C water, respectively, though a tube-lined suit worn by each subject. During HT-tilt, four of nine subjects developed presyncopal symptoms resulting in the termination of the tilt test. In contrast, no subject experienced presyncopal symptoms during NT-tilt, NT-tilt(cool), or HT-tilt(cool). During the HT-tilt procedure, mean arterial blood pressure (MAP) and cerebral blood flow velocity (CBFV) decreased. However, during HT-tilt(cool), MAP, total peripheral resistance, and CBFV were significantly greater relative to HT-tilt (all P heat-stressed humans.

  4. Association between human and animal thermal comfort indices and physiological heat stress indicators in dairy calves.

    Science.gov (United States)

    Kovács, L; Kézér, F L; Ruff, F; Szenci, O; Jurkovich, V

    2018-06-06

    Warm summer episodes have a significant effect on the overall health and well-being of young cattle; however, it is not known which temperature measure should be used for estimating heat stress in dairy calves. In this study, generalized linear mixed-effects models were used to estimate the relationships between thermal comfort indices and animal-based heat stress indicators in sixteen Holstein bull calves that were housed in individual calf hutches. Data were collected under continental weather characteristics over a 5-day period: day 1 (lower-temperature day), days 2 and 3 (heat stress days), and a 2-day post-stress period. Relative humidity, ambient temperature, the heat index, the humidex and five different temperature-humidity indices (THI) were used as thermal indices. Physiological variables monitored included respiratory rate, rectal temperature, ear skin temperature and heart rate. The heat index and the humidex measuring human thermal comfort were more closely associated with physiological measures than were the ambient temperature or the THIs (in case of heat index: R 2 = 0.87 for respiratory rate, R 2 = 0.63 for rectal temperature, R 2 = 0.70 for ear skin temperature, and R 2 = 0.78 for heart rate, respectively; in case of humidex: R 2 = 0.85 for respiratory rate, R 2 = 0.60 for rectal temperature, R 2 = 0.68 for ear skin temperature, and R 2 = 0.75 for heart rate, respectively). Based on our results, parameters of human outdoor comfort seem better to estimate heat stress in dairy calves in a continental region than those of THIs or ambient temperature. Copyright © 2018. Published by Elsevier Inc.

  5. Human thermal sensation and comfort in a non-uniform environment with personalized heating.

    Science.gov (United States)

    Deng, Qihong; Wang, Runhuai; Li, Yuguo; Miao, Yufeng; Zhao, Jinping

    2017-02-01

    Thermal comfort in traditionally uniform environment is apparent and can be improved by increasing energy expenses. To save energy, non-uniform environment implemented by personalized conditioning system attracts considerable attention, but human response in such environment is unclear. To investigate regional- and whole-body thermal sensation and comfort in a cool environment with personalized heating. In total 36 subjects (17 males and 19 females) including children, adults and the elderly, were involved in our experiment. Each subject was first asked to sit on a seat in an 18°C chamber (uniform environment) for 40min and then sit on a heating seat in a 16°C chamber (non-uniform environment) for another 40min after 10min break. Subjects' regional- and whole-body thermal sensation and comfort were surveyed by questionnaire and their skin temperatures were measured by wireless sensors. We statistically analyzed subjects' thermal sensation and comfort and their skin temperatures in different age and gender groups and compared them between the uniform and non-uniform environments. Overall thermal sensation and comfort votes were respectively neutral and just comfortable in 16°C chamber with personalized heating, which were significantly higher than those in 18°C chamber without heating (pthermal sensation and comfort was consistent in subjects of different age and gender. However, adults and the females were more sensitive to the effect of personalized heating and felt cooler and less comfort than children/elderly and the males respectively. Variations of the regional thermal sensation/comfort across human body were consistent with those of skin temperature. Personalized heating significantly improved human thermal sensation and comfort in non-uniform cooler environment, probably due to the fact that it increased skin temperature. However, the link between thermal sensation/comfort and variations of skin temperature is rather complex and warrant further

  6. EFFECT OF HEAT PRECONDITIONING BY MICROWAVE HYPERTHERMIA ON HUMAN SKELETAL MUSCLE AFTER ECCENTRIC EXERCISE

    Directory of Open Access Journals (Sweden)

    Norio Saga

    2008-03-01

    Full Text Available The purpose of this study was to clarify whether heat preconditioning results in less eccentric exercise-induced muscle damage and muscle soreness, and whether the repeated bout effect is enhanced by heat preconditioning prior to eccentric exercise. Nine untrained male volunteers aged 23 ± 3 years participated in this study. Heat preconditioning included treatment with a microwave hyperthermia unit (150 W, 20 min that was randomly applied to one of the subject's arms (MW; the other arm was used as a control (CON. One day after heat preconditioning, the subjects performed 24 maximal isokinetic eccentric contractions of the elbow flexors at 30°·s-1 (ECC1. One week after ECC1, the subjects repeated the procedure (ECC2. After each bout of exercise, maximal voluntary contraction (MVC, range of motion (ROM of the elbow joint, upper arm circumference, blood creatine kinase (CK activity and muscle soreness were measured. The subjects experienced both conditions at an interval of 3 weeks. MVC and ROM in the MW were significantly higher than those in the CON (p < 0.05 for ECC1; however, the heat preconditioning had no significant effect on upper arm circumference, blood CK activity, or muscle soreness following ECC1 and ECC2. Heat preconditioning may protect human skeletal muscle from eccentric exercise-induced muscle damage after a single bout of eccentric exercise but does not appear to promote the repeated bout effect after a second bout of eccentric exercise

  7. Comparative evaluation of human heat stress indices on selected hospital admissions in Sydney, Australia.

    Science.gov (United States)

    Goldie, James; Alexander, Lisa; Lewis, Sophie C; Sherwood, Steven

    2017-08-01

    To find appropriate regression model specifications for counts of the daily hospital admissions of a Sydney cohort and determine which human heat stress indices best improve the models' fit. We built parent models of eight daily counts of admission records using weather station observations, census population estimates and public holiday data. We added heat stress indices; models with lower Akaike Information Criterion scores were judged a better fit. Five of the eight parent models demonstrated adequate fit. Daily maximum Simplified Wet Bulb Globe Temperature (sWBGT) consistently improved fit more than most other indices; temperature and heatwave indices also modelled some health outcomes well. Humidity and heat-humidity indices better fit counts of patients who died following admission. Maximum sWBGT is an ideal measure of heat stress for these types of Sydney hospital admissions. Simple temperature indices are a good fallback where a narrower range of conditions is investigated. Implications for public health: This study confirms the importance of selecting appropriate heat stress indices for modelling. Epidemiologists projecting Sydney hospital admissions should use maximum sWBGT as a common measure of heat stress. Health organisations interested in short-range forecasting may prefer simple temperature indices. © 2017 The Authors.

  8. Convective Heat Transfer Coefficients of the Human Body under Forced Convection from Ceiling

    DEFF Research Database (Denmark)

    Kurazumi, Yoshihito; Rezgals, Lauris; Melikov, Arsen Krikor

    2014-01-01

    The average convective heat transfer coefficient for a seated human body exposed to downward flow from above was determined. Thermal manikin with complex body shape and size of an average Scandinavian female was used. The surface temperature distribution of the manikin’s body was as the skin...... of the convective heat transfer coefficient of the whole body (hc [W/(m2•K)]) was proposed: hc=4.088+6.592V1.715 for a seated naked body at 20ºC and hc=2.874+7.427V1.345 for a seated naked body at 26ºC. Differences in the convective heat transfer coefficient of the whole body in low air velocity range, V

  9. Combined facial heating and inhalation of hot air do not alter thermoeffector responses in humans

    Science.gov (United States)

    Wingo, Jonathan E.; Low, David A.; Keller, David M.; Kimura, Kenichi

    2015-01-01

    The influence of thermoreceptors in human facial skin on thermoeffector responses is equivocal; furthermore, the presence of thermoreceptors in the respiratory tract and their involvement in thermal homeostasis has not been elucidated. This study tested the hypothesis that hot air directed on the face and inhaled during whole body passive heat stress elicits an earlier onset and greater sensitivity of cutaneous vasodilation and sweating than that directed on an equal skin surface area away from the face. Six men and two women completed two trials separated by ∼1 wk. Participants were passively heated (water-perfused suit; core temperature increase ∼0.9°C) while hot air was directed on either the face or on the lower leg (counterbalanced). Skin blood flux (laser-Doppler flowmetry) and local sweat rate (capacitance hygrometry) were measured at the chest and one forearm. During hot-air heating, local temperatures of the cheek and leg were 38.4 ± 0.8°C and 38.8 ± 0.6°C, respectively (P = 0.18). Breathing hot air combined with facial heating did not affect mean body temperature onsets (P = 0.97 and 0.27 for arm and chest sites, respectively) or slopes of cutaneous vasodilation (P = 0.49 and 0.43 for arm and chest sites, respectively), or the onsets (P = 0.89 and 0.94 for arm and chest sites, respectively), or slopes of sweating (P = 0.48 and 0.65 for arm and chest sites, respectively). Based on these findings, respiratory tract thermoreceptors, if present in humans, and selective facial skin heating do not modulate thermoeffector responses during passive heat stress. PMID:26157054

  10. Influence of prolonged storage process, pasteurization, and heat treatment on biologically-active human milk proteins.

    Science.gov (United States)

    Chang, Jih-Chin; Chen, Chao-Huei; Fang, Li-Jung; Tsai, Chi-Ren; Chang, Yu-Chuan; Wang, Teh-Ming

    2013-12-01

    The bioactive proteins in human milk may be influenced by prolonged storage process, pasteurization, and heat treatment. This study was conducted to evaluate the effects of these procedures. Three forms of human milk - freshly expressed, frozen at -20°C for a prolonged duration, and pasteurized milk - were collected from 14 healthy lactating mothers and a milk bank. The concentrations of major bioactive proteins (secretory immunoglobulin A, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits. Changes in these proteins by heat treatment at 40°C or 60°C for 30 minutes were further evaluated. The mean concentrations of lactoferrin and secretory immunoglobulin A were significantly reduced by 66% and 25.9%, respectively, in pasteurized milk compared with those in freshly-expressed milk. Heat treatment at 40°C or 60°C did not cause significant changes in lactoferrin and secretory immunoglobulin A, but there was an apparent increase in lysozyme (p = 0.016). There were no significant differences in leptin level among these three forms of milk prior to (p = 0.153) or after heat treatment (p = 0.053). Various freezing/heating/pasteurization processes applied to human milk prior to delivery to neonates could affect the concentration of immunomodulatory proteins, especially lactoferrin, secretory immunoglobulin A, and lysozyme. Leptin was unaffected by the various handling processes tested. Fresh milk was found to be the best food for neonates. Further studies are warranted to evaluate the functional activity of these proteins and their effects on infants' immunological status. Copyright © 2013. Published by Elsevier B.V.

  11. A heterogeneous human tissue mimicking phantom for RF heating and MRI thermal monitoring verification.

    Science.gov (United States)

    Yuan, Yu; Wyatt, Cory; Maccarini, Paolo; Stauffer, Paul; Craciunescu, Oana; Macfall, James; Dewhirst, Mark; Das, Shiva K

    2012-04-07

    This paper describes a heterogeneous phantom that mimics a human thigh with a deep-seated tumor, for the purpose of studying the performance of radiofrequency (RF) heating equipment and non-invasive temperature monitoring with magnetic resonance imaging (MRI). The heterogeneous cylindrical phantom was constructed with an outer fat layer surrounding an inner core of phantom material mimicking muscle, tumor and marrow-filled bone. The component materials were formulated to have dielectric and thermal properties similar to human tissues. The dielectric properties of the tissue mimicking phantom materials were measured with a microwave vector network analyzer and impedance probe over the frequency range of 80-500 MHz and at temperatures of 24, 37 and 45 °C. The specific heat values of the component materials were measured using a differential scanning calorimeter over the temperature range of 15-55 °C. The thermal conductivity value was obtained from fitting the curves obtained from one-dimensional heat transfer measurement. The phantom was used to verify the operation of a cylindrical four-antenna annular phased array extremity applicator (140 MHz) by examining the proton resonance frequency shift (PRFS) thermal imaging patterns for various magnitude/phase settings (including settings to focus heating in tumors). For muscle and tumor materials, MRI was also used to measure T1/T2* values (1.5 T) and to obtain the slope of the PRFS phase change versus temperature change curve. The dielectric and thermal properties of the phantom materials were in close agreement to well-accepted published results for human tissues. The phantom was able to successfully demonstrate satisfactory operation of the tested heating equipment. The MRI-measured thermal distributions matched the expected patterns for various magnitude/phase settings of the applicator, allowing the phantom to be used as a quality assurance tool. Importantly, the material formulations for the various tissue types

  12. Periodic heat shock accelerated the chondrogenic differentiation of human mesenchymal stem cells in pellet culture.

    Directory of Open Access Journals (Sweden)

    Jing Chen

    Full Text Available Osteoarthritis (OA is one of diseases that seriously affect elderly people's quality of life. Human mesenchymal stem cells (hMSCs offer a potential promise for the joint repair in OA patients. However, chondrogenic differentiation from hMSCs in vitro takes a long time (∼ 6 weeks and differentiated cells are still not as functionally mature as primary isolated chondrocytes, though chemical stimulations and mechanical loading have been intensively studied to enhance the hMSC differentiation. On the other hand, thermal stimulations of hMSC chondrogenesis have not been well explored. In this study, the direct effects of mild heat shock (HS on the differentiation of hMSCs into chondrocytes in 3D pellet culture were investigated. Periodic HS at 41 °C for 1 hr significantly increased sulfated glycosaminoglycan in 3D pellet culture at Day 10 of chondrogenesis. Immunohistochemical and Western Blot analyses revealed an increased expression of collagen type II and aggrecan in heat-shocked pellets than non heat-shocked pellets on Day 17 of chondrogenesis. In addition, HS also upregulated the expression of collagen type I and X as well as heat shock protein 70 on Day 17 and 24 of differentiation. These results demonstrate that HS accelerated the chondrogenic differentiation of hMSCs and induced an early maturation of chondrocytes differentiated from hMSCs. The results of this study will guide the design of future protocols using thermal treatments to facilitate cartilage regeneration with human mesenchymal stem cells.

  13. Calorimetry Minisensor for the Localised Measurement of Surface Heat Dissipated from the Human Body.

    Science.gov (United States)

    Socorro, Fabiola; Rodríguez de Rivera, Pedro Jesús; Rodríguez de Rivera, Manuel

    2016-11-06

    We have developed a calorimetry sensor that can perform a local measurement of the surface heat dissipated from the human body. The operating principle is based on the law of conductive heat transfer: heat dissipated by the human body passes across a thermopile located between the individual and a thermostat. Body heat power is calculated from the signals measured by the thermopile and the amount of power dissipated across the thermostat in order to maintain a constant temperature. The first prototype we built had a detection area measuring 6 × 6 cm², while the second prototype, which is described herein, had a 2 × 2 cm² detection area. This new design offers three advantages over the initial one: (1) greater resolution and three times greater thermal sensitivity; (2) a twice as fast response; and (3) it can take measurements from smaller areas of the body. The sensor has a 5 mW resolution, but the uncertainty is greater, up to 15 mW, due to the measurement and calculation procedure. The order of magnitude of measurements made in healthy subjects ranged from 60 to 300 mW at a thermostat temperature of 28 °C and an ambient room temperature of 21 °C. The values measured by the sensor depend on the ambient temperature and the thermostat's temperature, while the power dissipated depends on the individual's metabolism and any physical and/or emotional activity.

  14. Oligonol supplementation modulates plasma volume and osmolality and sweating after heat load in humans.

    Science.gov (United States)

    Lee, JeongBeom; Shin, YoungOh; Murota, Hiroyuki

    2015-05-01

    Oligonol is a low-molecular-weight polyphenol that possesses antioxidant and anti-inflammatory properties. This study investigated the effects of Oligonol supplementation on sweating response, plasma volume (PV), and osmolality (Osm) after heat load in human volunteers. We conducted a placebo-controlled crossover trial. Participants took a daily dose of 200 mg Oligonol or placebo for 1 week. After a 2-week washout period, the subjects were switched to the other study arm. As a heat load, half-body immersion into hot water (42°C±0.5°C for 30 min) was performed in an automated climate chamber. Tympanic and mean body temperature (Tty, mTb) and whole-body sweat loss volume (WBSLV) were measured. Changes in PV, Osm, and serum levels of aldosterone and sodium were analyzed. Oligonol intake attenuated increases in Tty, mTb, and WBSLV after heat load compared with the placebo (Pbody temperature and excessive sweating under heat load in healthy humans, but interpretation of the results requires caution due to the potent diuretic effect of Oligonol.

  15. Heat Transfer Behavior across the Dentino-Enamel Junction in the Human Tooth.

    Directory of Open Access Journals (Sweden)

    Lin Niu

    Full Text Available During eating, the teeth usually endure the sharply temperature changes because of different foods. It is of importance to investigate the heat transfer and heat dissipation behavior of the dentino-enamel junction (DEJ of human tooth since dentine and enamel have different thermophysical properties. The spatial and temporal temperature distributions on the enamel, dentine, and pulpal chamber of both the human tooth and its discontinuous boundaries, were measured using infrared thermography using a stepped temperature increase on the outer boundary of enamel crowns. The thermal diffusivities for enamel and dentine were deduced from the time dependent temperature change at the enamel and dentine layers. The thermal conductivities for enamel and dentine were calculated to be 0.81 Wm-1K-1 and 0.48 Wm-1K-1 respectively. The observed temperature discontinuities across the interfaces between enamel, dentine and pulp-chamber layers were due to the difference of thermal conductivities at interfaces rather than to the phase transformation. The temperature gradient distributes continuously across the enamel and dentine layers and their junction below a temperature of 42°C, whilst a negative thermal resistance is observed at interfaces above 42°C. These results suggest that the microstructure of the dentin-enamel junction (DEJ junction play an important role in tooth heat transfer and protects the pulp from heat damage.

  16. Effects of different CMV-heat-inactivation-methods on growth factors in human breast milk.

    Science.gov (United States)

    Goelz, Rangmar; Hihn, Eva; Hamprecht, Klaus; Dietz, Klaus; Jahn, Gerhard; Poets, Christian; Elmlinger, Martin

    2009-04-01

    Preterm infants can inoculate virulent cytomegalovirus (CMV) through their mothers' raw breast milk. Complete virus inactivation is achieved only by heat treatment, but the effect on growth factors has never been assessed systematically. Insulin-like-growth-factor-1-, IGF-2-, insulin-like-growth-factor-binding-protein-2-, and IGFBP-3-concentrations were measured, before and after heating, in 51 breast-milk-samples from 28 mothers, and epidermal-growth-factor-concentrations in a subgroup of 35 samples from 22 mothers. Two heating methods were applied: Short-term (5 s) pasteurisation at 62, 65, and 72 degrees C, and long-term Holder-Pasteurisation (30 min) at 63 degrees C. IGF-1, IGF-2, IGFBP-2, and IGFBP-3 were measured by RIA, and EGF by ELISA. Heating for 30 min decreased significantly IGF-1 by 39.4%, IGF-2 by 9.9%, IGFBP-2 by 19.1%, and IGFBP-3 by 7.0%. In contrast, IGF-1, IGF-2, IGFBP-2, and IGFBP-3 were not altered significantly when using a short heating duration of 5 s, irrespective of the level of temperature, except for IGF-2 at 62 degrees C for 5 s (p = 0.041) and IGFBP-2 at 72 degrees C for 5 s (p = 0.025). Neither long- nor short-time heating methods changed the concentration of EGF. Only short heating methods (5 s, 62-72 degrees C) can preserve, almost completely, the concentrations of IGFs in human milk, whereas Holder-Pasteurization does not.

  17. Influence of Prolonged Storage Process, Pasteurization, and Heat Treatment on Biologically-active Human Milk Proteins

    Directory of Open Access Journals (Sweden)

    Jih-Chin Chang

    2013-12-01

    Conclusion: Various freezing/heating/pasteurization processes applied to human milk prior to delivery to neonates could affect the concentration of immunomodulatory proteins, especially lactoferrin, secretory immunoglobulin A, and lysozyme. Leptin was unaffected by the various handling processes tested. Fresh milk was found to be the best food for neonates. Further studies are warranted to evaluate the functional activity of these proteins and their effects on infants' immunological status.

  18. Exercise induces the release of heat shock protein 72 from the human brain in vivo

    OpenAIRE

    Lancaster, G. I.; Møller, K.; Nielsen, B.; Secher, N. H.; Febbraio, M. A.; Nybo, L.

    2004-01-01

    The present study tested the hypothesis that in response to physical stress the human brain has the capacity to release heat shock protein 72 (Hsp72) in vivo. Therefore, 6 humans (males) cycled for 180 minutes at 60% of their maximal oxygen uptake, and the cerebral Hsp72 response was determined on the basis of the internal jugular venous to arterial difference and global cerebral blood flow. At rest, there was a net balance of Hsp72 across the brain, but after 180 minutes of exercise, we were...

  19. Design of wearable hybrid generator for harvesting heat energy from human body depending on physiological activity

    Science.gov (United States)

    Kim, Myoung-Soo; Kim, Min-Ki; Kim, Kyongtae; Kim, Yong-Jun

    2017-09-01

    We developed a prototype of a wearable hybrid generator (WHG) that is used for harvesting the heat energy of the human body. This WHG is constructed by integrating a thermoelectric generator (TEG) in a circular mesh polyester knit fabric, circular-shaped pyroelectric generator (PEG), and quick sweat-pickup/dry-fabric. The fabric packaging enables the TEG part of the WHG to generate energy steadily while maintaining a temperature difference in extreme temperature environments. Moreover, when the body sweats, the evaporation heat of the sweat leads to thermal fluctuations in the WHG. This phenomenon further leads to an increase in the output power of the WHG. These characteristics of the WHG make it possible to produce electrical energy steadily without reduction in the conversion efficiency, as both TEG and PEG use the same energy source of the human skin and the ambient temperature. Under a temperature difference of ˜6.5 °C and temperature change rate of ˜0.62 °C s-1, the output power and output power density of the WHG, respectively, are ˜4.5 nW and ˜1.5 μW m-2. Our hybrid approach will provide a framework to enhance the output power of the wearable generators that harvest heat energy from human body in various environments.

  20. Selective activation of human heat shock gene transcription by nitrosourea antitumor drugs mediated by isocyanate-induced damage and activation of heat shock transcription factor.

    Science.gov (United States)

    Kroes, R A; Abravaya, K; Seidenfeld, J; Morimoto, R I

    1991-01-01

    Treatment of cultured human tumor cells with the chloroethylnitrosourea antitumor drug 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) selectively induces transcription and protein synthesis of a subset of the human heat shock or stress-induced genes (HSP90 and HSP70) with little effect on other stress genes or on expression of the c-fos, c-myc, or beta-actin genes. The active component of BCNU and related compounds appears to be the isocyanate moiety that causes carbamoylation of proteins and nucleic acids. Transcriptional activation of the human HSP70 gene by BCNU is dependent on the heat shock element and correlates with the level of heat shock transcription factor and its binding to the heat shock element in vivo. Unlike activation by heat or heavy metals, BCNU-mediated activation is strongly dependent upon new protein synthesis. This suggests that BCNU-induced, isocyanate-mediated damage to newly synthesized protein(s) may be responsible for activation of the heat shock transcription factor and increased transcription of the HSP90 and HSP70 genes. Images PMID:2052560

  1. Effect of human skin grafts on whole-body heat loss during exercise heat stress: a case report.

    Science.gov (United States)

    Ganio, Matthew S; Gagnon, Daniel; Stapleton, Jill; Crandall, Craig G; Kenny, Glen P

    2013-01-01

    When exposed to heat stress, increases in cutaneous blood flow and sweating in well-healed grafted skin are severely attenuated, which could impair whole-body heat loss if skin grafts cover a large portion of total body surface area (TBSA). It is unknown to what extent whole-body heat loss is impaired when skin grafts cover a significant (eg, >50%) proportion of TBSA. The authors examined whole-body heat exchange during and after 60 min of cycling exercise in the heat (35°C; 25% relative humidity), at a fixed rate of metabolic heat production (~400 W) in a woman (age, 36 years; mass, 78.2 kg) with well-healed (17+ years) skin grafts covering 75% of TBSA. Her responses were compared with two noninjured control subjects. Whole-body evaporative and dry heat exchange were measured by direct calorimetry. While exercising in the same ambient conditions and at the same rate of heat production, relative evaporative heat loss of nongrafted skin in the grafted subject (ie, evaporative heat loss per m) was nearly twice that of the control subjects. However, total rate of evaporative heat loss reached only 59% of the amount required for heat balance in the skin-grafted subject compared with 92 ± 3% in controls. Thus, the increase in core temperature was 2-fold greater for the grafted (1.22°C) vs control (0.61 ± 0.19°C) individuals. This case study demonstrates that a large area of grafted skin greatly diminishes maximum evaporative heat loss during exercise in the heat, making a compensable environment for control subjects uncompensable for skin-grafted individuals.

  2. CFD heat transfer simulation of the human upper respiratory tract for oronasal breathing condition

    Directory of Open Access Journals (Sweden)

    Kambiz Farahmand

    2012-01-01

    Full Text Available Injuries due to inhalation of hot gas are commonly encountered when dealing with fire and combustible material, which is harmful and threatens human life. In the literature, various studies have been conducted to investigate heat and mass transfer characteristics in the human respiratory tract (HRT. This study focuses on assessing the injury taking place in the upper human respiratory tract and identifying acute tissue damage, based on level of exposure. A three-dimensional heat transfer simulation is performed using Computational Fluid Dynamics (CFD software to study the temperature profile through the upper HRT consisting of the nasal cavity, oral cavity, trachea, and the first two generations of bronchi. The model developed is for the simultaneous oronasal breathing during the inspiration phase with a high volumetric flow rate of 90 liters/minute and the inspired air temperature of 100 degrees Celsius. The geometric model depicting the upper HRT is generated based on the data available and literature cited. The results of the simulation give the temperature distribution along the center and the surface tissue of the respiratory tract. This temperature distribution will help to assess the level of damage induced in the upper respiratory tract and appropriate treatment for the damage. A comparison of nasal breathing, oral breathing, and oronasal breathing is performed. Temperature distribution can be utilized in the design of the respirator systems where inlet temperature is regulated favoring the human body conditions.

  3. Improved numerical modelling of heat transfer in human tissue exposed to RF

    International Nuclear Information System (INIS)

    Prishvin, Mikheil; Zaridze, Revaz; Bit-Babik, Georgi; Faraone, Antonio

    2010-01-01

    Full text: A novel numerical model to simulate thermal response of human body tissues exposed to RF energy is presented in this article. It is based on a new algorithm for the construction of a realistic blood vessel network, a new model of blood flow velocity distribution and an approach to solve the bio-heat equation in human tissue with variable and initially unknown blood temperature distribution. The algorithm generates a discrete 3D representation of both arterial and venous vascular networks and a continuous blood velocity vector field for arbitrary enclosed geome tries required to represent the complex anatomy of human body and blood flow. The results obtained in this article by applying the developed method to realistic exposure con ditions demonstrates relative difference in thermal response of the exposed tissue compared to results obtained by conventional bio-heat equation with constant blood perfusion and temperature. The developed technique may provide more accurate and realistic modelling in thermal dosimetry studies of human body RF exposure.

  4. Prostaglandins with antiproliferative activity induce the synthesis of a heat shock protein in human cells

    International Nuclear Information System (INIS)

    Santoro, M.G.; Garaci, E.; Amici, C.

    1989-01-01

    Prostaglandins (PGs)A 1 and J 2 were found to potently suppress the proliferation of human K562 erythroleukemia cells and to induce the synthesis of a 74-kDa protein (p74) that was identified as a heat shock protein related to the major 70-kDa heat shock protein group. p74 synthesis was stimulated at doses of PGA 1 and PGJ 2 that inhibited cell replication, and its accumulation ceased upon removal of the PG-induced proliferation block. PGs that did not affect K562 cell replication did not induce p74 synthesis. p74 was found to be localized mainly in the cytoplasm of PG-treated cells, but moderate amounts were found also in dense areas of the nucleus after PGJ 2 treatment. p74 was not necessarily associated with cytotoxicity or with inhibition of cell protein synthesis. The results described support the hypothesis that synthesis of the 70-kDa heat shock proteins is associated with changes in cell proliferation. The observation that PGs can induce the synthesis of heat shock proteins expands our understanding of the mechanism of action of these compounds whose regulatory role is well known in many physiological phenomena, including the control of fever production

  5. Formation of tRNA granules in the nucleus of heat-induced human cells

    International Nuclear Information System (INIS)

    Miyagawa, Ryu; Mizuno, Rie; Watanabe, Kazunori; Ijiri, Kenichi

    2012-01-01

    Highlights: ► tRNAs are tranlocated into the nucleus in heat-induced HeLa cells. ► tRNAs form the unique granules in the nucleus. ► tRNA ganules overlap with nuclear stress granules. -- Abstract: The stress response, which can trigger various physiological phenomena, is important for living organisms. For instance, a number of stress-induced granules such as P-body and stress granule have been identified. These granules are formed in the cytoplasm under stress conditions and are associated with translational inhibition and mRNA decay. In the nucleus, there is a focus named nuclear stress body (nSB) that distinguishes these structures from cytoplasmic stress granules. Many splicing factors and long non-coding RNA species localize in nSBs as a result of stress. Indeed, tRNAs respond to several kinds of stress such as heat, oxidation or starvation. Although nuclear accumulation of tRNAs occurs in starved Saccharomyces cerevisiae, this phenomenon is not found in mammalian cells. We observed that initiator tRNA Met (Meti) is actively translocated into the nucleus of human cells under heat stress. During this study, we identified unique granules of Meti that overlapped with nSBs. Similarly, elongator tRNA Met was translocated into the nucleus and formed granules during heat stress. Formation of tRNA granules is closely related to the translocation ratio. Then, all tRNAs may form the specific granules.

  6. Wearing graduated compression stockings augments cutaneous vasodilation in heat-stressed resting humans.

    Science.gov (United States)

    Fujii, Naoto; Nikawa, Toshiya; Tsuji, Bun; Kondo, Narihiko; Kenny, Glen P; Nishiyasu, Takeshi

    2017-05-01

    We investigated whether graduated compression induced by stockings enhances cutaneous vasodilation in passively heated resting humans. Nine habitually active young men were heated at rest using water-perfusable suits, resulting in a 1.0 °C increase in body core temperature. Heating was repeated twice on separate occasions while wearing either (1) stockings that cause graduated compression (pressures of 26.4 ± 5.3, 17.5 ± 4.4, and 6.1 ± 2.0 mmHg at the ankle, calf, and thigh, respectively), or (2) loose-fitting stockings without causing compression (Control). Forearm vascular conductance during heating was evaluated by forearm blood flow (venous occlusion plethysmography) divided by mean arterial pressure to estimate heat-induced cutaneous vasodilation. Body core (esophageal), skin, and mean body temperatures were measured continuously. Compared to the Control, forearm vascular conductance during heating was higher with graduated compression stockings (e.g., 23.2 ± 5.5 vs. 28.6 ± 5.8 units at 45 min into heating, P = 0.001). In line with this, graduated compression stockings resulted in a greater sensitivity (27.5 ± 8.3 vs. 34.0 ± 9.4 units °C -1 , P = 0.02) and peak level (25.5 ± 5.8 vs. 29.7 ± 5.8 units, P = 0.004) of cutaneous vasodilation as evaluated from the relationship between forearm vascular conductance with mean body temperature. In contrast, the mean body temperature threshold for increases in forearm vascular conductance did not differ between the Control and graduated compression stockings (36.5 ± 0.1 vs. 36.5 ± 0.2 °C, P = 0.85). Our results show that graduated compression associated with the use of stockings augments cutaneous vasodilation by modulating sensitivity and peak level of cutaneous vasodilation in relation to mean body temperature. However, the effect of these changes on whole-body heat loss remains unclear.

  7. Experimental characterization of the BSD MAPA for heating of the human thigh

    International Nuclear Information System (INIS)

    Guerquin-Kern, J.L.; Hagmann, M.J.; Levin, R.L.; Glatstein, E.J.

    1985-01-01

    The authors began a series of experiments in order to characterize a Mini-Annular Phased Array (MAPA) applicator from the BSD Medical Corp. prior to possible clinical implementation at NIH. Heating patterns have been measured in simple cylindrical phantoms as well as a full-sized phantom-filled half-mannequin which is representative of the part of the human body that is below the waist. Implantable electric field probes have been used as well as non-perturbing temperature probes in these tests. The authors describe the relationship of measurements of the external electric field to changes in the heating pattern caused by lateral displacement of the phantom relative to the MAPA. The dependence of usable bandwidth upon phantom size and position, as well as upon the degree of bolus filling, is also described. Several recent tests made using two different types of helical coil applicators with the phantom-filled half-mannequin are also described for comparison

  8. Molecular action mechanisms of solar infrared radiation and heat on human skin.

    Science.gov (United States)

    Akhalaya, M Ya; Maksimov, G V; Rubin, A B; Lademann, J; Darvin, M E

    2014-07-01

    The generation of ROS underlies all solar infrared-affected therapeutic and pathological cutaneous effects. The signaling pathway NF-kB is responsible for the induced therapeutic effects, while the AP-1 for the pathological effects. The different signaling pathways of infrared-induced ROS and infrared-induced heat shock ROS were shown to act independently multiplying the influence on each other by increasing the doses of irradiation and/or increasing the temperature. The molecular action mechanisms of solar infrared radiation and heat on human skin are summarized and discussed in detail in the present paper. The critical doses are determined. Protection strategies against infrared-induced skin damage are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. The effect of simulated flash heating pasteurisation and Holder pasteurisation on human milk oligosaccharides.

    Science.gov (United States)

    Daniels, Brodie; Coutsoudis, Anna; Autran, Chloe; Amundson Mansen, Kimberly; Israel-Ballard, Kiersten; Bode, Lars

    2017-08-01

    Human milk oligosaccharides (HMOs) have important protective functions in human milk. A low-cost remote pasteurisation temperature-monitoring system has been designed using FoneAstra, a cell phone-based networked sensing system to monitor simulated flash heat pasteurisation. To compare the pasteurisation effect on HMOs of the FoneAstra FH method with the current Sterifeed Holder method used by human milk banks. Donor human milk samples (n = 48) were obtained from a human milk bank and pasteurised using the two pasteurisation methods. HMOs were purified from samples and labelled before separation using high-performance liquid chromatography. Concentrations of total HMOs, sialylated and fucosylated HMOs and individual HMOs using the two pasteurisation methods were compared using repeated-measures ANOVA. The study demonstrated no difference in total concentration of HMOs between the two pasteurisation methods and a small but significant increase in the total concentration of HMOs regardless of pasteurisation methods compared with controls (unpasteurised samples) (pmilk and therefore is a possible alternative for providing safely sterilised human milk for low- and middle-income countries.

  10. Changes in dermal interstitial ATP levels during local heating of human skin.

    Science.gov (United States)

    Gifford, Jayson R; Heal, Cory; Bridges, Jarom; Goldthorpe, Scott; Mack, Gary W

    2012-12-15

    Heating skin is believed to activate vanilloid type III and IV transient receptor potential ion channels (TRPV3, TRPV4, respectively), resulting in the release of ATP into the interstitial fluid. We examined the hypothesis that local skin heating would result in an accumulation of ATP in the interstitial fluid that would be related with a rise in skin blood flow (SkBF) and temperature sensation. Two microdialysis probes were inserted into the dermis on the dorsal aspect of the forearm in 15 young, healthy subjects. The probed skin was maintained at 31°C, 35°C, 39°C and 43°C for 8 min periods, during which SkBF was monitored as cutaneous vascular conductance (CVC). Dialysate was collected and analysed for ATP ([ATP](d)) using a luciferase-based assay, and ratings of perceived warmth were taken at each temperature. At a skin temperature of 31°C, [ATP](d) averaged 18.93 ± 4.06 nm and CVC averaged 12.57 ± 1.59% peak. Heating skin to 35°C resulted in an increase in CVC (17.63 ± 1.27% peak; P ATP](d). Heating skin to 39°C and 43°C resulted in a decreased [ATP](d) (5.88 ± 1.68 nm and 8.75 ± 3.44 nm, respectively; P ATP does not occur during local heating, and therefore does not have a role in temperature sensation or the dilator response in human skin. Nevertheless, the low threshold of dilatation (35°C) indicates a possible role for the TRPV3, TRPV4 channels or the sensitization of other ion channels in mediating the dilator response.

  11. Responses to hyperthermia. Optimizing heat dissipation by convection and evaporation: Neural control of skin blood flow and sweating in humans.

    Science.gov (United States)

    Smith, Caroline J; Johnson, John M

    2016-04-01

    Under normothermic, resting conditions, humans dissipate heat from the body at a rate approximately equal to heat production. Small discrepancies between heat production and heat elimination would, over time, lead to significant changes in heat storage and body temperature. When heat production or environmental temperature is high the challenge of maintaining heat balance is much greater. This matching of heat elimination with heat production is a function of the skin circulation facilitating heat transport to the body surface and sweating, enabling evaporative heat loss. These processes are manifestations of the autonomic control of cutaneous vasomotor and sudomotor functions and form the basis of this review. We focus on these systems in the responses to hyperthermia. In particular, the cutaneous vascular responses to heat stress and the current understanding of the neurovascular mechanisms involved. The available research regarding cutaneous active vasodilation and vasoconstriction is highlighted, with emphasis on active vasodilation as a major responder to heat stress. Involvement of the vasoconstrictor and active vasodilator controls of the skin circulation in the context of heat stress and nonthermoregulatory reflexes (blood pressure, exercise) are also considered. Autonomic involvement in the cutaneous vascular responses to direct heating and cooling of the skin are also discussed. We examine the autonomic control of sweating, including cholinergic and noncholinergic mechanisms, the local control of sweating, thermoregulatory and nonthermoregulatory reflex control and the possible relationship between sudomotor and cutaneous vasodilator function. Finally, we comment on the clinical relevance of these control schemes in conditions of autonomic dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Effect of using heat-inactivated serum with the Abbott human T-cell lymphotropic virus type III antibody test.

    OpenAIRE

    Jungkind, D L; DiRenzo, S A; Young, S J

    1986-01-01

    The Abbott enzyme immunoassay (Abbott Laboratories, North Chicago, Ill.) for human T-cell lymphotropic virus type III (HTLV-III) antibody was evaluated to determine the effect of using heat-inactivated (56 degrees C for 30 min) serum as the sample. Each of 58 nonreactive serum samples gave a higher A492 value when tested after heat inactivation. Ten of the samples became reactive after heating. Heat-inactivated serum should not be used in the current Abbott HTLV-III antibody test, because thi...

  13. Climate extremes in urban area and their impact on human health: the summer heat waves

    Science.gov (United States)

    Baldi, Marina

    2014-05-01

    Shanghai, which is particularly prone to heat waves, recorded the hottest summer in over 50 years. During the event, the maximum number of daily deaths was 317, 42% above the non-heat day average, even though an heat warning system in operation. In this study results from the analysis of heat waves events in Italian cities is presented. Indices representative of extremely hot conditions have been taken into account and results of the analysis of indices such as the number of summer days (SU), number of tropical nights (TR), maxima and minima of daily maximum and minimum temperatures (TXx, TXn, TNx, TNn, respectively), exceedances over fixed thresholds is presented. Results show a clear increase in the past decades of the numbers of days affected by heat events. Some considerations are also presented about the impact on human health of the longest events occurred in the Country.

  14. Formation of tRNA granules in the nucleus of heat-induced human cells

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Ryu [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Department of Biological Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan); Mizuno, Rie [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Watanabe, Kazunori, E-mail: watanabe@ric.u-tokyo.ac.jp [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Ijiri, Kenichi [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Department of Biological Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer tRNAs are tranlocated into the nucleus in heat-induced HeLa cells. Black-Right-Pointing-Pointer tRNAs form the unique granules in the nucleus. Black-Right-Pointing-Pointer tRNA ganules overlap with nuclear stress granules. -- Abstract: The stress response, which can trigger various physiological phenomena, is important for living organisms. For instance, a number of stress-induced granules such as P-body and stress granule have been identified. These granules are formed in the cytoplasm under stress conditions and are associated with translational inhibition and mRNA decay. In the nucleus, there is a focus named nuclear stress body (nSB) that distinguishes these structures from cytoplasmic stress granules. Many splicing factors and long non-coding RNA species localize in nSBs as a result of stress. Indeed, tRNAs respond to several kinds of stress such as heat, oxidation or starvation. Although nuclear accumulation of tRNAs occurs in starved Saccharomyces cerevisiae, this phenomenon is not found in mammalian cells. We observed that initiator tRNA{sup Met} (Meti) is actively translocated into the nucleus of human cells under heat stress. During this study, we identified unique granules of Meti that overlapped with nSBs. Similarly, elongator tRNA{sup Met} was translocated into the nucleus and formed granules during heat stress. Formation of tRNA granules is closely related to the translocation ratio. Then, all tRNAs may form the specific granules.

  15. VIP/PACAP receptor mediation of cutaneous active vasodilation during heat stress in humans.

    Science.gov (United States)

    Kellogg, Dean L; Zhao, Joan L; Wu, Yubo; Johnson, John M

    2010-07-01

    Vasoactive intestinal peptide (VIP) is implicated in cutaneous active vasodilation in humans. VIP and the closely related pituitary adenylate cyclase activating peptide (PACAP) act through several receptor types: VIP through VPAC1 and VPAC2 receptors and PACAP through VPAC1, VPAC2, and PAC1 receptors. We examined participation of VPAC2 and/or PAC1 receptors in cutaneous vasodilation during heat stress by testing the effects of their specific blockade with PACAP6-38. PACAP6-38 dissolved in Ringer's was administered by intradermal microdialysis at one forearm site while a control site received Ringer's solution. Skin blood flow was monitored by laser-Doppler flowmetry (LDF). Blood pressure was monitored noninvasively and cutaneous vascular conductance (CVC) calculated. A 5- to 10-min baseline period was followed by approximately 70 min of PACAP6-38 (100 microM) perfusion at one site in normothermia and a 3-min period of body cooling. Whole body heating was then performed to engage cutaneous active vasodilation and was maintained until CVC had plateaued at an elevated level at all sites for 5-10 min. Finally, 58 mM sodium nitroprusside was perfused through both microdialysis sites to effect maximal vasodilation. No CVC differences were found between control and PACAP6-38-treated sites during normothermia (19 +/- 3%max untreated vs. 20 +/- 3%max, PACAP6-38 treated; P > 0.05 between sites) or cold stress (11 +/- 2%max untreated vs. 10 +/- 2%max, PACAP6-38 treated, P > 0.05 between sites). PACAP6-38 attenuated the increase in CVC during whole body heating when compared with untreated sites (59 +/- 3%max untreated vs. 46 +/- 3%max, PACAP6-38 treated, P < 0.05). We conclude that VPAC2 and/or PAC1 receptor activation is involved in cutaneous active vasodilation in humans.

  16. Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans.

    Science.gov (United States)

    Brunt, Vienna E; Howard, Matthew J; Francisco, Michael A; Ely, Brett R; Minson, Christopher T

    2016-09-15

    A recent 30 year prospective study showed that lifelong sauna use reduces cardiovascular-related and all-cause mortality; however, the specific cardiovascular adaptations that cause this chronic protection are currently unknown. We investigated the effects of 8 weeks of repeated hot water immersion ('heat therapy') on various biomarkers of cardiovascular health in young, sedentary humans. We showed that, relative to a sham group which participated in thermoneutral water immersion, heat therapy increased flow-mediated dilatation, reduced arterial stiffness, reduced mean arterial and diastolic blood pressure, and reduced carotid intima media thickness, with changes all on par or greater than what is typically observed in sedentary subjects with exercise training. Our results show for the first time that heat therapy has widespread and robust effects on vascular function, and as such, could be a viable treatment option for improving cardiovascular health in a variety of patient populations, particularly those with limited exercise tolerance and/or capabilities. The majority of cardiovascular diseases are characterized by disorders of the arteries, predominantly caused by endothelial dysfunction and arterial stiffening. Intermittent hot water immersion ('heat therapy') results in elevations in core temperature and changes in cardiovascular haemodynamics, such as cardiac output and vascular shear stress, that are similar to exercise, and thus may provide an alternative means of improving health which could be utilized by patients with low exercise tolerance and/or capabilities. We sought to comprehensively assess the effects of 8 weeks of heat therapy on biomarkers of vascular function in young, sedentary subjects. Twenty young, sedentary subjects were assigned to participate in 8 weeks (4-5 times per week) of heat therapy (n = 10; immersion in a 40.5°C bath sufficient to maintain rectal temperature ≥ 38.5°C for 60 min per session) or thermoneutral water

  17. The Effect of Simulated Flash-Heat Pasteurization on Immune Components of Human Milk

    Directory of Open Access Journals (Sweden)

    Brodie Daniels

    2017-02-01

    Full Text Available A pasteurization temperature monitoring system has been designed using FoneAstra, a cellphone-based networked sensing system, to monitor simulated flash-heat (FH pasteurization. This study compared the effect of the FoneAstra FH (F-FH method with the Sterifeed Holder method currently used by human milk banks on human milk immune components (immunoglobulin A (IgA, lactoferrin activity, lysozyme activity, interleukin (IL-8 and IL-10. Donor milk samples (N = 50 were obtained from a human milk bank, and pasteurized. Concentrations of IgA, IL-8, IL-10, lysozyme activity and lactoferrin activity were compared to their controls using the Student’s t-test. Both methods demonstrated no destruction of interleukins. While the Holder method retained all lysozyme activity, the F-FH method only retained 78.4% activity (p < 0.0001, and both methods showed a decrease in lactoferrin activity (71.1% Holder vs. 38.6% F-FH; p < 0.0001 and a decrease in the retention of total IgA (78.9% Holder vs. 25.2% F-FH; p < 0.0001. Despite increased destruction of immune components compared to Holder pasteurization, the benefits of F-FH in terms of its low cost, feasibility, safety and retention of immune components make it a valuable resource in low-income countries for pasteurizing human milk, potentially saving infants’ lives.

  18. Small heat shock proteins potentiate amyloid dissolution by protein disaggregases from yeast and humans.

    Directory of Open Access Journals (Sweden)

    Martin L Duennwald

    Full Text Available How small heat shock proteins (sHsps might empower proteostasis networks to control beneficial prions or disassemble pathological amyloid is unknown. Here, we establish that yeast sHsps, Hsp26 and Hsp42, inhibit prionogenesis by the [PSI+] prion protein, Sup35, via distinct and synergistic mechanisms. Hsp42 prevents conformational rearrangements within molten oligomers that enable de novo prionogenesis and collaborates with Hsp70 to attenuate self-templating. By contrast, Hsp26 inhibits self-templating upon binding assembled prions. sHsp binding destabilizes Sup35 prions and promotes their disaggregation by Hsp104, Hsp70, and Hsp40. In yeast, Hsp26 or Hsp42 overexpression prevents [PSI+] induction, cures [PSI+], and potentiates [PSI+]-curing by Hsp104 overexpression. In vitro, sHsps enhance Hsp104-catalyzed disaggregation of pathological amyloid forms of α-synuclein and polyglutamine. Unexpectedly, in the absence of Hsp104, sHsps promote an unprecedented, gradual depolymerization of Sup35 prions by Hsp110, Hsp70, and Hsp40. This unanticipated amyloid-depolymerase activity is conserved from yeast to humans, which lack Hsp104 orthologues. A human sHsp, HspB5, stimulates depolymerization of α-synuclein amyloid by human Hsp110, Hsp70, and Hsp40. Thus, we elucidate a heretofore-unrecognized human amyloid-depolymerase system that could have applications in various neurodegenerative disorders.

  19. Epitopes of microbial and human heat shock protein 60 and their recognition in myalgic encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Amal Elfaitouri

    Full Text Available Myalgic encephalomyelitis (ME, also called Chronic Fatigue Syndrome, a common disease with chronic fatigability, cognitive dysfunction and myalgia of unknown etiology, often starts with an infection. The chaperonin human heat shock protein 60 (HSP60 occurs in mitochondria and in bacteria, is highly conserved, antigenic and a major autoantigen. The anti-HSP60 humoral (IgG and IgM immune response was studied in 69 ME patients and 76 blood donors (BD (the Training set with recombinant human and E coli HSP60, and 136 30-mer overlapping and targeted peptides from HSP60 of humans, Chlamydia, Mycoplasma and 26 other species in a multiplex suspension array. Peptides from HSP60 helix I had a chaperonin-like activity, but these and other HSP60 peptides also bound IgG and IgM with an ME preference, theoretically indicating a competition between HSP60 function and antibody binding. A HSP60-based panel of 25 antigens was selected. When evaluated with 61 other ME and 399 non-ME samples (331 BD, 20 Multiple Sclerosis and 48 Systemic Lupus Erythematosus patients, a peptide from Chlamydia pneumoniae HSP60 detected IgM in 15 of 61 (24% of ME, and in 1 of 399 non-ME at a high cutoff (p<0.0001. IgM to specific cross-reactive epitopes of human and microbial HSP60 occurs in a subset of ME, compatible with infection-induced autoimmunity.

  20. The Effect of Simulated Flash-Heat Pasteurization on Immune Components of Human Milk.

    Science.gov (United States)

    Daniels, Brodie; Schmidt, Stefan; King, Tracy; Israel-Ballard, Kiersten; Amundson Mansen, Kimberly; Coutsoudis, Anna

    2017-02-22

    A pasteurization temperature monitoring system has been designed using FoneAstra, a cellphone-based networked sensing system, to monitor simulated flash-heat (FH) pasteurization. This study compared the effect of the FoneAstra FH (F-FH) method with the Sterifeed Holder method currently used by human milk banks on human milk immune components (immunoglobulin A (IgA), lactoferrin activity, lysozyme activity, interleukin (IL)-8 and IL-10). Donor milk samples ( N = 50) were obtained from a human milk bank, and pasteurized. Concentrations of IgA, IL-8, IL-10, lysozyme activity and lactoferrin activity were compared to their controls using the Student's t -test. Both methods demonstrated no destruction of interleukins. While the Holder method retained all lysozyme activity, the F-FH method only retained 78.4% activity ( p pasteurization, the benefits of F-FH in terms of its low cost, feasibility, safety and retention of immune components make it a valuable resource in low-income countries for pasteurizing human milk, potentially saving infants' lives.

  1. Thermal response of rat fibroblasts stably transfected with the human 70-kDa heat shock protein-encoding gene

    International Nuclear Information System (INIS)

    Li, G.C.; Li, Ligeng; Liu, Yunkang; Mak, J.Y.; Chen, Lili; Lee, W.M.F.

    1991-01-01

    The major heat shock protein hsp70 is synthesized by cells of a wide variety of organisms in response to heat shock or other environmental stresses and is assumed to play an important role in protecting cells from thermal stress. The authors have tested this hypothesis directly by transfecting a constitutively expressed recombinant human hsp70-encoding gene into rat fibroblasts and examining the relationship between the levels of human hsp70 expressed and thermal resistance of the stably transfected rat cells. Successful transfection and expression of the gene for human hsp70 were characterized by RNA hybridization analysis, low-dimensional gel electrophoresis, and immunoblot analysis. When individual cloned cell lines were exposed to 45C and their thermal survivals were determined by colony-formation assay, they found that the expression of human hsp70 conferred heat resistance to the rat cells. These results reinforce the hypothesis that hsp70 has a protective function against thermal stress

  2. Novel mitochondria-targeted heat-soluble proteins identified in the anhydrobiotic Tardigrade improve osmotic tolerance of human cells.

    Directory of Open Access Journals (Sweden)

    Sae Tanaka

    Full Text Available Tardigrades are able to tolerate almost complete dehydration through transition to a metabolically inactive state, called "anhydrobiosis". Late Embryogenesis Abundant (LEA proteins are heat-soluble proteins involved in the desiccation tolerance of many anhydrobiotic organisms. Tardigrades, Ramazzottius varieornatus, however, express predominantly tardigrade-unique heat-soluble proteins: CAHS (Cytoplasmic Abundant Heat Soluble and SAHS (Secretory Abundant Heat Soluble proteins, which are secreted or localized in most intracellular compartments, except the mitochondria. Although mitochondrial integrity is crucial to ensure cellular survival, protective molecules for mitochondria have remained elusive. Here, we identified two novel mitochondrial heat-soluble proteins, RvLEAM and MAHS (Mitochondrial Abundant Heat Soluble, as potent mitochondrial protectants from Ramazzottius varieornatus. RvLEAM is a group3 LEA protein and immunohistochemistry confirmed its mitochondrial localization in tardigrade cells. MAHS-green fluorescent protein fusion protein localized in human mitochondria and was heat-soluble in vitro, though no sequence similarity with other known proteins was found, and one region was conserved among tardigrades. Furthermore, we demonstrated that RvLEAM protein as well as MAHS protein improved the hyperosmotic tolerance of human cells. The findings of the present study revealed that tardigrade mitochondria contain at least two types of heat-soluble proteins that might have protective roles in water-deficient environments.

  3. Effect of heat treatment of wood on the morphology, surface roughness and penetration of simulated and human blood.

    Science.gov (United States)

    Rekola, J; Lassila, L V J; Nganga, S; Ylä-Soininmäki, A; Fleming, G J P; Grenman, R; Aho, A J; Vallittu, P K

    2014-01-01

    Wood has been used as a model material for the development of novel fiber-reinforced composite bone substitute biomaterials. In previous studies heat treatment of wood was perceived to significantly increase the osteoconductivity of implanted wood material. The objective of this study was to examine some of the changing attributes of wood materials that may contribute to improved biological responses gained with heat treatment. Untreated and 140°C and 200°C heat-treated downy birch (Betula pubescens Ehrh.) were used as the wood materials. Surface roughness and the effect of pre-measurement grinding were measured with contact and non-contact profilometry. Liquid interaction was assessed with a dipping test using two manufactured liquids (simulated blood) as well as human blood. SEM was used to visualize possible heat treatment-induced changes in the hierarchical structure of wood. The surface roughness was observed to significantly decrease with heat treatment. Grinding methods had more influence on the surface contour and roughness than heat treatment. The penetration of the human blood in the 200°C heat-treated exceeded that in the untreated and 140°C heat-treated materials. SEM showed no significant change due to heat treatment in the dry-state morphology of the wood. The results of the liquid penetration test support previous findings in literature concerning the effects of heat treatment on the biological response to implanted wood. Heat-treatment has only a marginal effect on the surface contour of wood. The highly specialized liquid conveyance system of wood may serve as a biomimetic model for the further development of tailored fiber-composite materials.

  4. Dynamic Simulation of Human Thermoregulation and Heat Transfer for Spaceflight Applications

    Science.gov (United States)

    Miller, Thomas R.; Nelson, David A.; Bue, Grant; Kuznetz, Lawrence

    2011-01-01

    Models of human thermoregulation and heat transfer date from the early 1970s and have been developed for applications ranging from evaluating thermal comfort in spacecraft and aircraft cabin environments to predicting heat stress during EVAs. Most lumped or compartment models represent the body as an assemblage cylindrical and spherical elements which may be subdivided into layers to describe tissue heterogeneity. Many existing models are of limited usefulness in asymmetric thermal environments, such as may be encountered during an EVA. Conventional whole-body clothing models also limit the ability to describe local surface thermal and evaporation effects in sufficient detail. A further limitation is that models based on a standard man model are not readily scalable to represent large or small subjects. This work describes development of a new human thermal model derived from the 41-node man model. Each segment is divided into four concentric, constant thickness cylinders made up of a central core surrounded by muscle, fat, and skin, respectively. These cylinders are connected by the flow of blood from a central blood pool to each part. The central blood pool is updated at each time step, based on a whole-body energy balance. Results show the model simulates core and surface temperature histories, sweat evaporation and metabolic rates which generally are consistent with controlled exposures of human subjects. Scaling rules are developed to enable simulation of small and large subjects (5th percentile and 95th percentile). Future refinements will include a clothing model that addresses local surface insulation and permeation effects and developing control equations to describe thermoregulatory effects such as may occur with prolonged weightlessness or with aging.

  5. Heat, Human Performance, and Occupational Health: A Key Issue for the Assessment of Global Climate Change Impacts.

    Science.gov (United States)

    Kjellstrom, Tord; Briggs, David; Freyberg, Chris; Lemke, Bruno; Otto, Matthias; Hyatt, Olivia

    2016-01-01

    Ambient heat exposure is a well-known health hazard, which reduces human performance and work capacity at heat levels already common in tropical and subtropical areas. Various health problems have been reported. Increasing heat exposure during the hottest seasons of each year is a key feature of global climate change. Heat exhaustion and reduced human performance are often overlooked in climate change health impact analysis. Later this century, many among the four billion people who live in hot areas worldwide will experience significantly reduced work capacity owing to climate change. In some areas, 30-40% of annual daylight hours will become too hot for work to be carried out. The social and economic impacts will be considerable, with global gross domestic product (GDP) losses greater than 20% by 2100. The analysis to date is piecemeal. More analysis of climate change-related occupational health impact assessments is greatly needed.

  6. Human body heat for powering wearable devices: From thermal energy to application

    International Nuclear Information System (INIS)

    Thielen, Moritz; Sigrist, Lukas; Magno, Michele; Hierold, Christofer; Benini, Luca

    2017-01-01

    Highlights: • A complete system optimization for wearable thermal harvesting from body heat to the application is proposed. • State-of-the-art thermal harvesters and DC-DC converters are compared and classified. • Extensive simulation and experiments are carried out to characterize the harvesting performance. • A case study demonstrates the feasibility to supply a multi-sensor wearables only from body heat. - Abstract: Energy harvesting is the key technology to enable self-sustained wearable devices for the Internet of Things and medical applications. Among various types of harvesting sources such as light, vibration and radio frequency, thermoelectric generators (TEG) are a promising option due to their independence of light conditions or the activity of the wearer. This work investigates scavenging of human body heat and the optimization of the power conversion efficiency from body core to the application. We focus on the critical interaction between thermal harvester and power conditioning circuitry and compare two approaches: (1) a high output voltage, low thermal resistance μTEG combined with a high efficiency actively controlled single inductor DC-DC converter, and (2) a high thermal resistance, low electric resistance mTEG in combination with a low-input voltage coupled inductors based DC-DC converter. The mTEG approach delivers up to 65% higher output power per area in a lab setup and 1–15% in a real-world experiment on the human body depending on physical activity and environmental conditions. Using off-the-shelf and low-cost components, we achieve an average power of 260 μW (μTEG) to 280 μW (mTEG) and power densities of 13 μW cm"−"2 (μTEG) to 14 μW cm"−"2 (mTEG) for systems worn on the human wrist. With the small and lightweight harvesters optimized for wearability, 16% (mTEG) to 24% (μTEG) of the theoretical maximum efficiency is achieved in a worst-case scenario. This efficiency highly depends on the application specific conditions

  7. Expression of Heat Shock Proteins in Human Fibroblast Cells under Magnetic Resonant Coupling Wireless Power Transfer

    Directory of Open Access Journals (Sweden)

    Kohei Mizuno

    2015-10-01

    Full Text Available Since 2007, resonant coupling wireless power transfer (WPT technology has been attracting attention and has been widely researched for practical use. Moreover, dosimetric evaluation has also been discussed to evaluate the potential health risks of the electromagnetic field from this WPT technology based on the International Commission on Non-Ionizing Radiation Protection (ICNIRP guidelines. However, there has not been much experimental evaluation of the potential health risks of this WPT technology. In this study, to evaluate whether magnetic resonant coupling WPT induces cellular stress, we focused on heat shock proteins (Hsps and determined the expression level of Hsps 27, 70 and 90 in WI38VA13 subcloned 2RA human fibroblast cells using a western blotting method. The expression level of Hsps under conditions of magnetic resonant coupling WPT for 24 h was not significantly different compared with control cells, although the expression level of Hsps for cells exposed to heat stress conditions was significantly increased. These results suggested that exposure to magnetic resonant coupling WPT did not cause detectable cell stress.

  8. Morphological response of human rotavirus to ultra-violet radiation, heat and disinfectants

    International Nuclear Information System (INIS)

    Rodgers, F.G.; Hufton, P.; Kurzawska, E.; Molloy, C.; Morgan, S.

    1985-01-01

    The morphological damage induced in human rotavirus particles by exposure to UV radiation (254 nm) increased progressively with length of treatment. Exposure of the virus in suspension to 9000 ergs/cm 2 /s removed the smooth capsid layer from 50% of particles after 1 min and from all the virions within 10 min. By this time, the number of stain-penetrated or empty particles increased markedly, along with the appearance of virus-derived debris in the form of disrupted and isolated capsomeres. After treatment for 120 min no intact virus particles were observed. The action of wet (100 0 C) or dry (60 0 C) heat resulted in changes similar to those effected by UV radiation. Sodium hypochlorite, cetrimide and 70% ethanol induced a rapid loss of the outer capsid layer, but, compared with UV radiation or heat, a slower increase in the number of stain-penetrated particles was noted. Chlorhexidine and phenol had effects on virus structure only after extended periods of exposure, whilst glutaraldehyde treatment had little influence on virus morphology. Glutaraldehyde 2% v/v would appear to be most suitable for the disinfection of rotavirus-containing electron microscope grids before their examination. (author)

  9. Changes in relative fit of human heat stress indices to cardiovascular, respiratory, and renal hospitalizations across five Australian urban populations

    Science.gov (United States)

    Goldie, James; Alexander, Lisa; Lewis, Sophie C.; Sherwood, Steven C.; Bambrick, Hilary

    2018-03-01

    Various human heat stress indices have been developed to relate atmospheric measures of extreme heat to human health impacts, but the usefulness of different indices across various health impacts and in different populations is poorly understood. This paper determines which heat stress indices best fit hospital admissions for sets of cardiovascular, respiratory, and renal diseases across five Australian cities. We hypothesized that the best indices would be largely dependent on location. We fit parent models to these counts in the summers (November-March) between 2001 and 2013 using negative binomial regression. We then added 15 heat stress indices to these models, ranking their goodness of fit using the Akaike information criterion. Admissions for each health outcome were nearly always higher in hot or humid conditions. Contrary to our hypothesis that location would determine the best-fitting heat stress index, we found that the best indices were related largely by health outcome of interest, rather than location as hypothesized. In particular, heatwave and temperature indices had the best fit to cardiovascular admissions, humidity indices had the best fit to respiratory admissions, and combined heat-humidity indices had the best fit to renal admissions. With a few exceptions, the results were similar across all five cities. The best-fitting heat stress indices appear to be useful across several Australian cities with differing climates, but they may have varying usefulness depending on the outcome of interest. These findings suggest that future research on heat and health impacts, and in particular hospital demand modeling, could better reflect reality if it avoided "all-cause" health outcomes and used heat stress indices appropriate to specific diseases and disease groups.

  10. Changes in relative fit of human heat stress indices to cardiovascular, respiratory, and renal hospitalizations across five Australian urban populations.

    Science.gov (United States)

    Goldie, James; Alexander, Lisa; Lewis, Sophie C; Sherwood, Steven C; Bambrick, Hilary

    2018-03-01

    Various human heat stress indices have been developed to relate atmospheric measures of extreme heat to human health impacts, but the usefulness of different indices across various health impacts and in different populations is poorly understood. This paper determines which heat stress indices best fit hospital admissions for sets of cardiovascular, respiratory, and renal diseases across five Australian cities. We hypothesized that the best indices would be largely dependent on location. We fit parent models to these counts in the summers (November-March) between 2001 and 2013 using negative binomial regression. We then added 15 heat stress indices to these models, ranking their goodness of fit using the Akaike information criterion. Admissions for each health outcome were nearly always higher in hot or humid conditions. Contrary to our hypothesis that location would determine the best-fitting heat stress index, we found that the best indices were related largely by health outcome of interest, rather than location as hypothesized. In particular, heatwave and temperature indices had the best fit to cardiovascular admissions, humidity indices had the best fit to respiratory admissions, and combined heat-humidity indices had the best fit to renal admissions. With a few exceptions, the results were similar across all five cities. The best-fitting heat stress indices appear to be useful across several Australian cities with differing climates, but they may have varying usefulness depending on the outcome of interest. These findings suggest that future research on heat and health impacts, and in particular hospital demand modeling, could better reflect reality if it avoided "all-cause" health outcomes and used heat stress indices appropriate to specific diseases and disease groups.

  11. Prediction of heat-illness symptoms with the prediction of human vascular response in hot environment under resting condition.

    Science.gov (United States)

    Aggarwal, Yogender; Karan, Bhuwan Mohan; Das, Barsa Nand; Sinha, Rakesh Kumar

    2008-04-01

    The thermoregulatory control of human skin blood flow is vital to maintain the body heat storage during challenges of thermal homeostasis under heat stress. Whenever thermal homeostasis disturbed, the heat load exceeds heat dissipation capacity, which alters the cutaneous vascular responses along with other body physiological variables. Whole body skin blood flow has been calculated from the forearm blood flow. Present model has been designed using electronics circuit simulator (Multisim 8.0, National Instruments, USA), is to execute a series of predictive equations for early prediction of physiological parameters of young nude subjects during resting condition at various level of dry heat stress under almost still air to avoid causalities associated with hot environmental. The users can execute the model by changing the environmental temperature in degrees C and exposure time in minutes. The model would be able to predict and detect the changes in human vascular responses along with other physiological parameters and from this predicted values heat related-illness symptoms can be inferred.

  12. Intelligent Integration between Human Simulated Intelligence and Expert Control Technology for the Combustion Process of Gas Heating Furnace

    Directory of Open Access Journals (Sweden)

    Yucheng Liu

    2014-01-01

    Full Text Available Due to being poor in control quality of the combustion process of gas heating furnace, this paper explored a sort of strong robust control algorithm in order to improve the control quality of the combustion process of gas heating furnace. The paper analyzed the control puzzle in the complex combustion process of gas heating furnace, summarized the cybernetics characteristic of the complex combustion process, researched into control strategy of the uncertainty complex control process, discussed the control model of the complex process, presented a sort of intelligent integration between human-simulated intelligence and expert control technology, and constructed the control algorithm for the combustion process controlling of gas heating furnace. The simulation results showed that the control algorithm proposed in the paper is not only better in dynamic and steady quality of the combustion process, but also obvious in energy saving effect, feasible, and effective in control strategy.

  13. Vasomotion in human skin before and after local heating recorded with laser Doppler flowmetry. A method for induction of vasomotion

    DEFF Research Database (Denmark)

    Kastrup, J; Bülow, J; Lassen, N A

    1989-01-01

    neurogenic origin. A method for induction of regular amplified alpha-oscillations was discovered and evaluated. When heating the skin locally to 42 degrees C the blood cell flux increased and the pre-heating alpha- and beta-oscillations disappeared. During the post-heating period, amplified regular rhythmic......Rhythmical variations in blood cell flux in human skin have been studied using laser Doppler flowmetry. The fluctuations in blood cell flux could be divided into two different categories named alpha- and beta-oscillations with a median frequency of 6.8 min-1 and 1.5 min-1, respectively...... alpha-oscillations appeared. At the end of the post-heating period beta-oscillations re-appeared....

  14. PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70-KILODALTON HEAT SHOCK PROTEIN HSPA2

    Science.gov (United States)

    THE PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70 kDa HEAT SHOCK PROTEIN HSPA2* Gabor Huszar1, Kathryn Stone2, David Dix3 and Lynne Vigue11The Sperm Physiology Laboratory, Department of Obstetrics and Gynecology, 2 W.M. Keck Foundatio...

  15. A mathematical model of endovascular heat transfer for human brain cooling

    Science.gov (United States)

    Salsac, Anne-Virginie; Lasheras, Juan Carlos; Yon, Steven; Magers, Mike; Dobak, John

    2000-11-01

    Selective cooling of the brain has been shown to exhibit protective effects in cerebral ischemia, trauma, and spinal injury/ischemia. A multi-compartment, unsteady thermal model of the response of the human brain to endovascular cooling is discussed and its results compared to recent experimental data conducted with sheep and other mammals. The model formulation is based on the extension of the bioheat equation, originally proposed by Pennes(1) and later modified by Wissler(2), Stolwijk(3) and Werner and Webb(4). The temporal response of the brain temperature and that of the various body compartments to the cooling of the blood flowing through the common carotid artery is calculated under various scenarios. The effect of the boundary conditions as well as the closure assumptions used in the model, i.e. perfusion rate, metabolism heat production, etc. on the cooling rate of the brain are systematically investigated. (1) Pennes H. H., “Analysis of tissue and arterial blood temperature in the resting forearm.” J. Appl. Physiol. 1: 93-122, 1948. (2) Wissler E. H., “Steady-state temperature distribution in man”, J. Appl. Physiol., 16: 764-740, 1961. (3) Stolwick J. A. J., “Mathematical model of thermoregulation” in “Physiological and behavioral temperature regulation”, edited by J. D. Hardy, A. P. Gagge and A. J. Stolwijk, Charles C. Thomas Publisher, Springfiels, Ill., 703-721, 1971. (4) Werner J., Webb P., “A six-cylinder model of human thermoregulation for general use on personal computers”, Ann. Physiol. Anthrop., 12(3): 123-134, 1993.

  16. Human cadaver retina model for retinal heating during corneal surgery with a femtosecond laser

    Science.gov (United States)

    Sun, Hui; Fan, Zhongwei; Yun, Jin; Zhao, Tianzhuo; Yan, Ying; Kurtz, Ron M.; Juhasz, Tibor

    2014-02-01

    Femtosecond lasers are widely used in everyday clinical procedures to perform minimally invasive corneal refractive surgery. The intralase femtosecond laser (AMO Corp. Santa Ana, CA) is a common example of such a laser. In the present study a numerical simulation was developed to quantify the temperature rise in the retina during femtosecond intracorneal surgery. Also, ex-vivo retinal heating due to laser irradiation was measured with an infrared thermal camera (Fluke Corp. Everett, WA) as a validation of the simulation. A computer simulation was developed using Comsol Multiphysics to calculate the temperature rise in the cadaver retina during femtosecond laser corneal surgery. The simulation showed a temperature rise of less than 0.3 degrees for realistic pulse energies for the various repetition rates. Human cadaver retinas were irradiated with a 150 kHz Intralase femtosecond laser and the temperature rise was measured withan infrared thermal camera. Thermal camera measurements are in agreement with the simulation. During routine femtosecond laser corneal surgery with normal clinical parameters, the temperature rise is well beneath the threshold for retina damage. The simulation predictions are in agreement with thermal measurements providing a level of experimental validation.

  17. Human recombinant factor VIIa may improve heat intolerance in mice by attenuating hypothalamic neuronal apoptosis and damage.

    Science.gov (United States)

    Hsu, Chuan-Chih; Chen, Sheng-Hsien; Lin, Cheng-Hsien; Yung, Ming-Chi

    2014-10-01

    Intolerance to heat exposure is believed to be associated with hypothalamo-pituitary-adrenocortical (HPA) axis impairment [reflected by decreases in blood concentrations of both adrenocorticotrophic-hormone (ACTH) and corticosterone]. The purpose of this study was to determine the effect of human recombinant factor VIIa (rfVIIa) on heat intolerance, HPA axis impairment, and hypothalamic inflammation, ischemic and oxidative damage, and apoptosis in mice under heat stress. Immediately after heat stress (41.2 °C for 1 h), mice were treated with vehicle (1 mL/kg of body weight) or rfVIIa (65-270 µg/kg of body weight) and then returned to room temperature (26 °C). Mice still alive on day 4 of heat exposure were considered survivors. Cellular ischemia markers (e.g., glutamate, lactate-to-pyruvate ratio), oxidative damage markers (e.g., nitric oxide metabolite, hydroxyl radials), and pro-inflammatory cytokines (e.g., interleukin-6, interleukin-1β, tumor necrosis factor-α) in hypothalamus were determined. In addition, blood concentrations of both ACTH and corticosterone were measured. Hypothalamic cell damage was assessed by determing the neuronal damage scores, whereas the hypothalamic cell apoptosis was determined by assessing the numbers of cells stained with terminal deoxynucleotidyl transferase-mediated αUTP nick-end labeling, caspase-3-positive cells, and platelet endothelial cell adhesion molecula-1-positive cells in hypothalamus. Compared with vehicle-treated heated mice, rfVIIa-treated heated mice had significantly higher fractional survival (8/10 vs 1/10), lesser thermoregulatory deficit (34.1 vs 24.8 °C), lesser extents of ischemic, oxidative, and inflammatory markers in hypothalamus, lesser neuronal damage scores and apoptosis in hypothalamus, and lesser HPA axis impairment. Human recombinant factor VIIa appears to exert a protective effect against heatstroke by attenuating hypothalamic cell apoptosis (due to ischemic, inflammatory, and oxidative damage

  18. Mathematical Model for Localised and Surface Heat Flux of the Human Body Obtained from Measurements Performed with a Calorimetry Minisensor

    Science.gov (United States)

    Socorro, Fabiola; Rodríguez de Rivera, Pedro Jesús; Rodríguez de Rivera, Miriam

    2017-01-01

    The accuracy of the direct and local measurements of the heat power dissipated by the surface of the human body, using a calorimetry minisensor, is directly related to the calibration rigor of the sensor and the correct interpretation of the experimental results. For this, it is necessary to know the characteristics of the body’s local heat dissipation. When the sensor is placed on the surface of the human body, the body reacts until a steady state is reached. We propose a mathematical model that represents the rate of heat flow at a given location on the surface of a human body by the sum of a series of exponentials: W(t) = A0 + ∑Aiexp(−t/τi). In this way, transient and steady states of heat dissipation can be interpreted. This hypothesis has been tested by simulating the operation of the sensor. At the steady state, the power detected in the measurement area (4 cm2) varies depending on the sensor’s thermostat temperature, as well as the physical state of the subject. For instance, for a thermostat temperature of 24 °C, this power can vary between 100–250 mW in a healthy adult. In the transient state, two exponentials are sufficient to represent this dissipation, with 3 and 70 s being the mean values of its time constants. PMID:29182567

  19. Mathematical Model for Localised and Surface Heat Flux of the Human Body Obtained from Measurements Performed with a Calorimetry Minisensor.

    Science.gov (United States)

    Socorro, Fabiola; Rodríguez de Rivera, Pedro Jesús; Rodríguez de Rivera, Miriam; Rodríguez de Rivera, Manuel

    2017-11-28

    The accuracy of the direct and local measurements of the heat power dissipated by the surface of the human body, using a calorimetry minisensor, is directly related to the calibration rigor of the sensor and the correct interpretation of the experimental results. For this, it is necessary to know the characteristics of the body's local heat dissipation. When the sensor is placed on the surface of the human body, the body reacts until a steady state is reached. We propose a mathematical model that represents the rate of heat flow at a given location on the surface of a human body by the sum of a series of exponentials: W ( t ) = A ₀ + ∑A i exp( -t / τ i ). In this way, transient and steady states of heat dissipation can be interpreted. This hypothesis has been tested by simulating the operation of the sensor. At the steady state, the power detected in the measurement area (4 cm²) varies depending on the sensor's thermostat temperature, as well as the physical state of the subject. For instance, for a thermostat temperature of 24 °C, this power can vary between 100-250 mW in a healthy adult. In the transient state, two exponentials are sufficient to represent this dissipation, with 3 and 70 s being the mean values of its time constants.

  20. [The effect of heat stress on the cytoskeleton and cell cycle of human umbilical vein endothelial cell in vitro].

    Science.gov (United States)

    Pan, Zhiguo; Shao, Yu; Geng, Yan; Chen, Jinghe; Su, Lei

    2015-08-01

    To study the effect of heat stress on the cytoskeleton and cell cycle of human umbilical vein endothelial cell ( HUVEC ) in vitro. HUVEC was cultured in vitro in 5%CO(2) medium at 37 centigrade ( control group ) or 43 centigrade ( heat stress group ) for 1 hour. Coomassie brilliant blue R-250 staining was used to determine the effect of heat stress on the cytoskeleton. The cells in heat stress group were subsequently cultured at 37 centigradein 5%CO(2) medium after heat stress for 1 hour, and cell cycle of HUVEC was determined at 0, 6, 12, 18 and 24 hours with flow cytometry. Under light microscopy normal cytoskeleton was observed in control group, but thicker and shorter cytoskeleton was found after a rise of temperature, and stress fibers were found in heat stress group. The DNA content of HUVEC at all time points in G0/G1 stage was 38.07%-55.19% after heat stress. The DNA content in control group was 48.57%, and it was 54.06%, 55.19%, 48.23%, 38.07%, and 41.03% at 0, 6, 12, 18, 24 hours in G0/G1 stage in heat stress group. DNA content in S phase was 35.33%-48.18%. The DNA content in control group was 44.62%, and it was 35.33%, 39.50%, 42.50%, 48.18%, and 47.99% at 0, 6, 12, 18, 24 hours in S stage in heat stress group. DNA content in G2/M phase was 5.31%-13.75%. The DNA content in control group was 6.81, and it was 10.61%, 5.31%, 9.27%,13.75%, and 10.98% at 0, 6, 12, 18, 24 hours in G2/M stage in heat stress group. It was demonstrated that compared with control group, the DNA content in G0/G1 stage was significantly increased when the HUVEC were separated from heat stress within 6 hours, and it recovered at a similar level as control group at 12 hours. Heat stress can change the cytoskeleton of HUVEC, and cause stagnation at G0/G1 stage in cell cycle.

  1. Microcalorimetric measurements of heat production in human erythrocytes. IV. Comparison between different calorimetric techniques, suspension media, and preparation methods.

    Science.gov (United States)

    Monti, M; Wadsö, I

    1976-10-01

    Heat production in human erythrocytes from healthy subjects has been measured under different experimental conditions. Simultaneous measurements were made on the same samples using different types of microcalorimeters: a static ampoule calorimeter, an air perfusion calorimeter, and a flow calorimeter. Obtained heat effect values for specified standard conditions, P degrees, were within uncertainty limits the same for the different calorimeters. Cells were suspended either in autologous plasma or in a phosphate buffer. P degrees values for buffer suspensions were significantly higher than those for plasma suspensions. Erythrocyte samples prepared by the column adsorption technique gave higher P degrees values than those obtained by a conventional centrifugation procedure.

  2. Effects of passive heating on central blood volume and ventricular dimensions in humans

    DEFF Research Database (Denmark)

    Crandall, C.G.; Wilson, T.E.; Marving, J.

    2008-01-01

    Mixed findings regarding the effects of whole-body heat stress on central blood volume have been reported. This study evaluated the hypothesis that heat stress reduces central blood volume and alters blood volume distribution. Ten healthy experimental and seven healthy time control (i.e. non-heat...... stressed) subjects participated in this protocol. Changes in regional blood volume during heat stress and time control were estimated using technetium-99m labelled autologous red blood cells and gamma camera imaging. Whole-body heating increased internal temperature (> 1.0 degrees C), cutaneous vascular...... conductance (approximately fivefold), and heart rate (52 +/- 2 to 93 +/- 4 beats min(-1)), while reducing central venous pressure (5.5 +/- 07 to 0.2 +/- 0.6 mmHg) accompanied by minor decreases in mean arterial pressure (all P heat stress reduced the blood volume of the heart (18 +/- 2%), heart...

  3. Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans.

    Science.gov (United States)

    Romero, Steven A; Gagnon, Daniel; Adams, Amy N; Cramer, Matthew N; Kouda, Ken; Crandall, Craig G

    2017-01-01

    Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P lower limb heating improves both macro- and microvascular dilator function in an age dependent manner. We demonstrate that lower limb heating acutely improves macro- and microvascular dilator function within the atherosclerotic prone vasculature of the leg in aged adults. These findings provide evidence for a potential therapeutic use of chronic lower limb heating to improve vascular health in primary aging and various disease conditions. Copyright © 2017 the American Physiological Society.

  4. Differential heat shock response of primary human cell cultures and established cell lines

    DEFF Research Database (Denmark)

    Richter, W W; Issinger, O G

    1986-01-01

    degrees C treatment, whereas in immortalized cell lines usually 90% of the cells were found in suspension. Enhanced expression of the major heat shock protein (hsp 70) was found in all heat-treated cells. In contrast to the primary cell cultures, established and transformed cell lines synthesized...

  5. Temperature and blood flow distribution in the human leg during passive heat stress.

    Science.gov (United States)

    Chiesa, Scott T; Trangmar, Steven J; González-Alonso, José

    2016-05-01

    The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. Copyright © 2016 the American Physiological Society.

  6. Performance and Costs of Ductless Heat Pumps in Marine-Climate High-Performance Homes -- Habitat for Humanity The Woods

    Energy Technology Data Exchange (ETDEWEB)

    Lubliner, Michael [Building America Partnership for Improved Residential Construction, Olympia, WA (United States). Washington States Univ. Energy Program; Howard, Luke [Building America Partnership for Improved Residential Construction, Olympia, WA (United States). Washington States Univ. Energy Program; Hales, David [Building America Partnership for Improved Residential Construction, Olympia, WA (United States). Washington States Univ. Energy Program; Kunkle, Rick [Building America Partnership for Improved Residential Construction, Olympia, WA (United States). Washington States Univ. Energy Program; Gordon, Andy [Building America Partnership for Improved Residential Construction, Olympia, WA (United States). Washington States Univ. Energy Program; Spencer, Melinda [Building America Partnership for Improved Residential Construction, Olympia, WA (United States). Washington States Univ. Energy Program

    2016-02-18

    The Woods is a Habitat for Humanity (HFH) community of ENERGY STAR Homes Northwest (ESHNW)-certified homes located in the marine climate of Tacoma/Pierce County, Washington. This research report builds on an earlier preliminary draft 2014 BA report, and includes significant billing analysis and cost effectiveness research from a collaborative, ongoing Ductless Heat Pump (DHP)research effort for Tacoma Public Utilities (TPU) and Bonneville Power Administration (BPA). This report focuses on the results of field testing, modeling, and monitoring of ductless mini-split heat pump hybrid heating systems in seven homes built and first occupied at various times between September 2013 and October 2014. The report also provides WSU documentation of high-performance home observations, lessons learned, and stakeholder recommendations for builders of affordable high-performance housing such as HFH. Tacoma Public Utilities (TPU) and Bonneville Power Administration (BPA). This report focuses on the results of field testing, modeling, and monitoring of ductless mini-split heat pump hybrid heating systems in seven homes built and first occupied at various times between September 2013 and October 2014. The report also provides WSU documentation of high-performance home observations, lessons learned, and stakeholder recommendations for builders of affordable high-performance housing such as HFH.

  7. Oligonol Supplementation Affects Leukocyte and Immune Cell Counts after Heat Loading in Humans

    Directory of Open Access Journals (Sweden)

    Jeong Beom Lee

    2014-06-01

    Full Text Available Oligonol is a low-molecular-weight form of polyphenol and has antioxidant and anti-inflammatory activity, making it a potential promoter of immunity. This study investigates the effects of oligonol supplementation on leukocyte and immune cell counts after heat loading in 19 healthy male volunteers. The participants took a daily dose of 200 mg oligonol or a placebo for 1 week. After a 2-week washout period, the subjects were switched to the other study arm. After each supplement, half-body immersion into hot water was made, and blood was collected. Then, complete and differential blood counts were performed. Flow cytometry was used to enumerate and phenotype lymphocyte subsets. Serum concentrations of interleukin (IL-1β and IL-6 in blood samples were analyzed. Lymphocyte subpopulation variables included counts of total T cells, B cells, and natural killer (NK cells. Oligonol intake attenuated elevations in IL-1β (an 11.1-fold change vs. a 13.9-fold change immediately after heating; a 12.0-fold change vs. a 12.6-fold change 1h after heating and IL-6 (an 8.6-fold change vs. a 9.9-fold change immediately after heating; a 9.1-fold change vs. a 10.5-fold change 1h after heating immediately and 1 h after heating in comparison to those in the placebo group. Oligonol supplementation led to significantly higher numbers of leukocytes (a 30.0% change vs. a 21.5% change immediately after heating; a 13.5% change vs. a 3.5% change 1h after heating and lymphocytes (a 47.3% change vs. a 39.3% change immediately after heating; a 19.08% change vs. a 2.1% change 1h after heating relative to those in the placebo group. Oligonol intake led to larger increases in T cells, B cells, and NK cells at rest (p < 0.05, p < 0.05, and p < 0.001, respectively and immediately after heating (p < 0.001 in comparison to those in the placebo group. In addition, levels of T cells (p < 0.001 and B cells (p < 0.001 were significantly higher 1 h after heating in comparison to those in

  8. Calcitonin gene-related peptide modulates heat nociception in the human brain - An fMRI study in healthy volunteers

    DEFF Research Database (Denmark)

    Asghar, Mohammad Sohail; Becerra, Lino; Larsson, Henrik B.W.

    2016-01-01

    Background: Intravenous infusion of calcitonin-gene-related-peptide (CGRP) provokes headache and migraine in humans. Mechanisms underlying CGRP-induced headache are not fully clarified and it is unknown to what extent CGRP modulates nociceptive processing in the brain. To elucidate this we recorded...... cortex. Sumatriptan injection reversed these changes. Conclusion: The changes in BOLD-signals in the brain after CGRP infusion suggests that systemic CGRP modulates nociceptive transmission in the trigeminal pain pathways in response to noxious heat stimuli....

  9. The effects of the 1996–2012 summer heat events on human mortality in Slovakia

    Directory of Open Access Journals (Sweden)

    Výberči Dalibor

    2015-09-01

    Full Text Available The impacts of summer heat events on the mortality of the Slovak population, both in total and for selected population sub-groups, are the foci of this study. This research is the first of its kind, focusing on a given population, and therefore one priority was to create a knowledge base for the issue and to basically evaluate existing conditions for the heat-mortality relationship in Slovakia. This article also aims to fill a void in current research on these issues in Europe. In addition to overall effects, we focused individually on the major historical heat events which occurred in the summers of 2007, 2010 and 2012. During the heat events, a non-negligible negative response in mortality was recorded and fatal effects were more pronounced during particularly strong heat events and periods which lasted for two or more days. In general, females and the elderly were the most sensitive groups in the population and mortality was characterized by several specific effects in individual population groups. The most extreme heat periods were commonly followed by a deficit in mortality, corresponding to a short-term mortality displacement, the pattern of which varied in specific cases. In general, displaced mortality appeared to compensate for a large part of heat-induced excess deaths.

  10. Adaptations and mechanisms of human heat acclimation: Applications for competitive athletes and sports.

    Science.gov (United States)

    Périard, J D; Racinais, S; Sawka, M N

    2015-06-01

    Exercise heat acclimation induces physiological adaptations that improve thermoregulation, attenuate physiological strain, reduce the risk of serious heat illness, and improve aerobic performance in warm-hot environments and potentially in temperate environments. The adaptations include improved sweating, improved skin blood flow, lowered body temperatures, reduced cardiovascular strain, improved fluid balance, altered metabolism, and enhanced cellular protection. The magnitudes of adaptations are determined by the intensity, duration, frequency, and number of heat exposures, as well as the environmental conditions (i.e., dry or humid heat). Evidence is emerging that controlled hyperthermia regimens where a target core temperature is maintained, enable more rapid and complete adaptations relative to the traditional constant work rate exercise heat acclimation regimens. Furthermore, inducing heat acclimation outdoors in a natural field setting may provide more specific adaptations based on direct exposure to the exact environmental and exercise conditions to be encountered during competition. This review initially examines the physiological adaptations associated with heat acclimation induction regimens, and subsequently emphasizes their application to competitive athletes and sports. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Ocular blood flow decreases during passive heat stress in resting humans

    OpenAIRE

    Ikemura, Tsukasa; Miyaji, Akane; Kashima, Hideaki; Yamaguchi, Yuji; Hayashi, Naoyuki

    2013-01-01

    Background Heat stress induces various physiological changes and so could influence ocular circulation. This study examined the effect of heat stress on ocular blood flow. Findings Ocular blood flow, end-tidal carbon dioxide (P ETCO2) and blood pressure were measured for 12 healthy subjects wearing water-perfused tube-lined suits under two conditions of water circulation: (1) at 35°C (normothermia) for 30 min and (2) at 50°C for 90 min (passive heat stress). The blood-flow velocities in the s...

  12. Chaperone activity of human small heat shock protein-GST fusion proteins.

    Science.gov (United States)

    Arbach, Hannah; Butler, Caley; McMenimen, Kathryn A

    2017-07-01

    Small heat shock proteins (sHsps) are a ubiquitous part of the machinery that maintains cellular protein homeostasis by acting as molecular chaperones. sHsps bind to and prevent the aggregation of partially folded substrate proteins in an ATP-independent manner. sHsps are dynamic, forming an ensemble of structures from dimers to large oligomers through concentration-dependent equilibrium dissociation. Based on structural studies and mutagenesis experiments, it is proposed that the dimer is the smallest active chaperone unit, while larger oligomers may act as storage depots for sHsps or play additional roles in chaperone function. The complexity and dynamic nature of their structural organization has made elucidation of their chaperone function challenging. HspB1 and HspB5 are two canonical human sHsps that vary in sequence and are expressed in a wide variety of tissues. In order to determine the role of the dimer in chaperone activity, glutathione-S-transferase (GST) was genetically linked as a fusion protein to the N-terminus regions of both HspB1 and HspB5 (also known as Hsp27 and αB-crystallin, respectively) proteins in order to constrain oligomer formation of HspB1 and HspB5, by using GST, since it readily forms a dimeric structure. We monitored the chaperone activity of these fusion proteins, which suggest they primarily form dimers and monomers and function as active molecular chaperones. Furthermore, the two different fusion proteins exhibit different chaperone activity for two model substrate proteins, citrate synthase (CS) and malate dehydrogenase (MDH). GST-HspB1 prevents more aggregation of MDH compared to GST-HspB5 and wild type HspB1. However, when CS is the substrate, both GST-HspB1 and GST-HspB5 are equally effective chaperones. Furthermore, wild type proteins do not display equal activity toward the substrates, suggesting that each sHsp exhibits different substrate specificity. Thus, substrate specificity, as described here for full-length GST

  13. Distinct Skeletal Muscle Gene Regulation from Active Contraction, Passive Vibration, and Whole Body Heat Stress in Humans.

    Science.gov (United States)

    Petrie, Michael A; Kimball, Amy L; McHenry, Colleen L; Suneja, Manish; Yen, Chu-Ling; Sharma, Arpit; Shields, Richard K

    2016-01-01

    Skeletal muscle exercise regulates several important metabolic genes in humans. We know little about the effects of environmental stress (heat) and mechanical stress (vibration) on skeletal muscle. Passive mechanical stress or systemic heat stress are often used in combination with many active exercise programs. We designed a method to deliver a vibration stress and systemic heat stress to compare the effects with active skeletal muscle contraction. The purpose of this study is to examine whether active mechanical stress (muscle contraction), passive mechanical stress (vibration), or systemic whole body heat stress regulates key gene signatures associated with muscle metabolism, hypertrophy/atrophy, and inflammation/repair. Eleven subjects, six able-bodied and five with chronic spinal cord injury (SCI) participated in the study. The six able-bodied subjects sat in a heat stress chamber for 30 minutes. Five subjects with SCI received a single dose of limb-segment vibration or a dose of repetitive electrically induced muscle contractions. Three hours after the completion of each stress, we performed a muscle biopsy (vastus lateralis or soleus) to analyze mRNA gene expression. We discovered repetitive active muscle contractions up regulated metabolic transcription factors NR4A3 (12.45 fold), PGC-1α (5.46 fold), and ABRA (5.98 fold); and repressed MSTN (0.56 fold). Heat stress repressed PGC-1α (0.74 fold change; p muscle contraction. Vibration induced FOXK2 (p muscle contractions. Understanding these responses may assist in developing regenerative rehabilitation interventions to improve muscle cell development, growth, and repair.

  14. Inhibition of c-Kit signaling is associated with reduced heat and cold pain sensitivity in humans.

    Science.gov (United States)

    Ceko, Marta; Milenkovic, Nevena; le Coutre, Philipp; Westermann, Jörg; Lewin, Gary R

    2014-07-01

    The tyrosine kinase receptor c-Kit is critically involved in the modulation of nociceptive sensitivity in mice. Ablation of the c-Kit gene results in hyposensitivity to thermal pain, whereas activation of c-Kit produces hypersensitivity to noxious heat, without altering sensitivity to innocuous mechanical stimuli. In this study, we investigated the role of c-Kit signaling in human pain perception. We hypothesized that subjects treated with Imatinib or Nilotinib, potent inhibitors of tyrosine kinases including c-Kit but also Abl1, PDFGFRα, and PDFGFRβ, that are used to treat chronic myeloid leukemia (CML), would experience changes in thermal pain sensitivity. We examined 31 asymptomatic CML patients (14 male and 17 female) receiving Imatinib/Nilotinib treatment and compared them to 39 age- and sex-matched healthy controls (12 male and 27 female). We used cutaneous heat and cold stimulation to test normal and noxious thermal sensitivity, and a grating orientation task to assess tactile acuity. Thermal pain thresholds were significantly increased in the Imatinib/Nilotinib-treated group, whereas innocuous thermal and tactile thresholds were unchanged compared to those in the control group. In conclusion, our findings suggest that the biological effects of c-Kit inhibition are comparable in mice and humans in that c-Kit activity is required to regulate thermal pain sensitivity but does not affect innocuous thermal and mechanical sensation. The effect on experimental heat pain observed in our study is comparable to those of several common analgesics; thus modulation of the c-Kit pathway can be used to specifically modulate noxious heat and cold sensitivity in humans. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  15. Communicating the deadly consequences of global warming for human heat stress

    Science.gov (United States)

    Matthews, Tom K. R.; Wilby, Robert L.; Murphy, Conor

    2017-04-01

    In December of 2015, the international community pledged to limit global warming to below 2 °C above preindustrial (PI) to prevent dangerous climate change. However, to what extent, and for whom, is danger avoided if this ambitious target is realized? We address these questions by scrutinizing heat stress, because the frequency of extremely hot weather is expected to continue to rise in the approach to the 2 °C limit. We use analogs and the extreme South Asian heat of 2015 as a focusing event to help interpret the increasing frequency of deadly heat under specified amounts of global warming. Using a large ensemble of climate models, our results confirm that global mean air temperature is nonlinearly related to heat stress, meaning that the same future warming as realized to date could trigger larger increases in societal impacts than historically experienced. This nonlinearity is higher for heat stress metrics that integrate the effect of rising humidity. We show that, even in a climate held to 2 °C above PI, Karachi (Pakistan) and Kolkata (India) could expect conditions equivalent to their deadly 2015 heatwaves every year. With only 1.5 °C of global warming, twice as many megacities (such as Lagos, Nigeria, and Shanghai, China) could become heat stressed, exposing more than 350 million more people to deadly heat by 2050 under a midrange population growth scenario. The results underscore that, even if the Paris targets are realized, there could still be a significant adaptation imperative for vulnerable urban populations.

  16. Communicating the deadly consequences of global warming for human heat stress.

    Science.gov (United States)

    Matthews, Tom K R; Wilby, Robert L; Murphy, Conor

    2017-04-11

    In December of 2015, the international community pledged to limit global warming to below 2 °C above preindustrial (PI) to prevent dangerous climate change. However, to what extent, and for whom, is danger avoided if this ambitious target is realized? We address these questions by scrutinizing heat stress, because the frequency of extremely hot weather is expected to continue to rise in the approach to the 2 °C limit. We use analogs and the extreme South Asian heat of 2015 as a focusing event to help interpret the increasing frequency of deadly heat under specified amounts of global warming. Using a large ensemble of climate models, our results confirm that global mean air temperature is nonlinearly related to heat stress, meaning that the same future warming as realized to date could trigger larger increases in societal impacts than historically experienced. This nonlinearity is higher for heat stress metrics that integrate the effect of rising humidity. We show that, even in a climate held to 2 °C above PI, Karachi (Pakistan) and Kolkata (India) could expect conditions equivalent to their deadly 2015 heatwaves every year. With only 1.5 °C of global warming, twice as many megacities (such as Lagos, Nigeria, and Shanghai, China) could become heat stressed, exposing more than 350 million more people to deadly heat by 2050 under a midrange population growth scenario. The results underscore that, even if the Paris targets are realized, there could still be a significant adaptation imperative for vulnerable urban populations.

  17. Ocular blood flow decreases during passive heat stress in resting humans.

    Science.gov (United States)

    Ikemura, Tsukasa; Miyaji, Akane; Kashima, Hideaki; Yamaguchi, Yuji; Hayashi, Naoyuki

    2013-12-06

    Heat stress induces various physiological changes and so could influence ocular circulation. This study examined the effect of heat stress on ocular blood flow. Ocular blood flow, end-tidal carbon dioxide (P(ET)CO2) and blood pressure were measured for 12 healthy subjects wearing water-perfused tube-lined suits under two conditions of water circulation: (1) at 35 °C (normothermia) for 30 min and (2) at 50 °C for 90 min (passive heat stress). The blood-flow velocities in the superior temporal retinal arteriole (STRA), superior nasal retinal arteriole (SNRA), and the retinal and choroidal vessels (RCV) were measured using laser-speckle flowgraphy. Blood flow in the STRA and SNRA was calculated from the integral of a cross-sectional map of blood velocity. PETCO2 was clamped at the normothermia level by adding 5% CO2 to the inspired gas. Passive heat stress had no effect on the subjects' blood pressures. The blood-flow velocity in the RCV was significantly lower after 30, 60 and 90 min of passive heat stress than the normothermic level, with a peak decrease of 18 ± 3% (mean ± SE) at 90 min. Blood flow in the STRA and SNRA decreased significantly after 90 min of passive heat stress conditions, with peak decreases of 14 ± 3% and 14 ± 4%, respectively. The findings of this study suggest that passive heat stress decreases ocular blood flow irrespective of the blood pressure or arterial partial pressure of CO2.

  18. Effects of face/head and whole body cooling during passive heat stress on human somatosensory processing.

    Science.gov (United States)

    Nakata, Hiroki; Namba, Mari; Kakigi, Ryusuke; Shibasaki, Manabu

    2017-06-01

    We herein investigated the effects of face/head and whole body cooling during passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs) at C4' and Fz electrodes. Fourteen healthy subjects received a median nerve stimulation at the left wrist. SEPs were recorded at normothermic baseline (Rest), when esophageal temperature had increased by ~1.2°C (heat stress: HS) during passive heating, face/head cooling during passive heating (face/head cooling: FHC), and after HS (whole body cooling: WBC). The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4' and P14, N18, P22, and N30 at Fz were evaluated. Latency indicated speed of the subcortical and cortical somatosensory processing, while amplitude reflected the strength of neural activity. Blood flow in the internal and common carotid arteries (ICA and CCA, respectively) and psychological comfort were recorded in each session. Increases in esophageal temperature due to HS significantly decreased the amplitude of N60, psychological comfort, and ICA blood flow in the HS session, and also shortened the latencies of SEPs (all, P body temperature. Copyright © 2017 the American Physiological Society.

  19. Heat-related deaths in hot cities: estimates of human tolerance to high temperature thresholds.

    Science.gov (United States)

    Harlan, Sharon L; Chowell, Gerardo; Yang, Shuo; Petitti, Diana B; Morales Butler, Emmanuel J; Ruddell, Benjamin L; Ruddell, Darren M

    2014-03-20

    In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90-97 °F; 32.2-36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

  20. Distinct Skeletal Muscle Gene Regulation from Active Contraction, Passive Vibration, and Whole Body Heat Stress in Humans.

    Directory of Open Access Journals (Sweden)

    Michael A Petrie

    Full Text Available Skeletal muscle exercise regulates several important metabolic genes in humans. We know little about the effects of environmental stress (heat and mechanical stress (vibration on skeletal muscle. Passive mechanical stress or systemic heat stress are often used in combination with many active exercise programs. We designed a method to deliver a vibration stress and systemic heat stress to compare the effects with active skeletal muscle contraction.The purpose of this study is to examine whether active mechanical stress (muscle contraction, passive mechanical stress (vibration, or systemic whole body heat stress regulates key gene signatures associated with muscle metabolism, hypertrophy/atrophy, and inflammation/repair.Eleven subjects, six able-bodied and five with chronic spinal cord injury (SCI participated in the study. The six able-bodied subjects sat in a heat stress chamber for 30 minutes. Five subjects with SCI received a single dose of limb-segment vibration or a dose of repetitive electrically induced muscle contractions. Three hours after the completion of each stress, we performed a muscle biopsy (vastus lateralis or soleus to analyze mRNA gene expression.We discovered repetitive active muscle contractions up regulated metabolic transcription factors NR4A3 (12.45 fold, PGC-1α (5.46 fold, and ABRA (5.98 fold; and repressed MSTN (0.56 fold. Heat stress repressed PGC-1α (0.74 fold change; p < 0.05; while vibration induced FOXK2 (2.36 fold change; p < 0.05. Vibration similarly caused a down regulation of MSTN (0.74 fold change; p < 0.05, but to a lesser extent than active muscle contraction. Vibration induced FOXK2 (p < 0.05 while heat stress repressed PGC-1α (0.74 fold and ANKRD1 genes (0.51 fold; p < 0.05.These findings support a distinct gene regulation in response to heat stress, vibration, and muscle contractions. Understanding these responses may assist in developing regenerative rehabilitation interventions to improve muscle cell

  1. Response of Urban Systems to Climate Change in Europe: Heat Stress Exposure and the Effect on Human Health

    Science.gov (United States)

    Stevens, Catherine; Thomas, Bart; Grommen, Mart

    2015-04-01

    Climate change is driven by global processes such as the global ocean circulation and its variability over time leading to changing weather patterns on regional scales as well as changes in the severity and occurrence of extreme events such as heavy rain- and windstorms, floods, drought, heat waves, etc. The summer 2003 European heat wave was the hottest summer on record in Europe over the past centuries leading to health crises in several countries like France and caused up to 70.000 excess deaths over four months in Central and Western Europe. The main risks induced by global climate change in urbanised areas are considered to be overheating and resulting health effects, increased exposure to flood events, increased damage losses from extreme weather conditions but also shortages in the provision of life-sustaining services. Moreover, the cities themselves create specific or inherent risks and urban adaptation is often very demanding. As most of Europe's inhabitants live in cities, it is of particular relevance to examine the impact of climate variability on urban areas and their populations. The present study focusses on the identification of heat stress variables related to human health and the extraction of this information by processing daily temperature statistics of local urban climate simulations over multiple timeframes of 20 years and three different European cities based on recent, near future and far future global climate predictions. The analyses have been conducted in the framework of the NACLIM FP7 project funded by the European Commission involving local stakeholders such as the cities of Antwerp (Belgium), Berlin (Germany) and Almada (Portugal) represented by different climate and urban characteristics. Apart from the urban-rural temperature increment (urban heat island effect), additional heat stress parameters such as the average number of heat wave days together with their duration and intensities have been covered during this research. In a

  2. Discovering a Reliable Heat-Shock Factor-1 Inhibitor to Treat Human Cancers: Potential Opportunity for Phytochemists

    Directory of Open Access Journals (Sweden)

    Murugesan Velayutham

    2018-04-01

    Full Text Available Heat-shock factor-1 (HSF-1 is an important transcription factor that regulates pathogenesis of many human diseases through its extensive transcriptional regulation. Especially, it shows pleiotropic effects in human cancer, and hence it has recently received increased attention of cancer researchers. After myriad investigations on HSF-1, the field has advanced to the phase where there is consensus that finding a potent and selective pharmacological inhibitor for this transcription factor will be a major break-through in the treatment of various human cancers. Presently, all reported inhibitors have their limitations, made evident at different stages of clinical trials. This brief account summarizes the advances with tested natural products as HSF-1 inhibitors and highlights the necessity of phytochemistry in this endeavor of discovering a potent pharmacological HSF-1 inhibitor.

  3. A Novel mouse model of enhanced proteostasis: Full-length human heat shock factor 1 transgenic mice

    International Nuclear Information System (INIS)

    Pierce, Anson; Wei, Rochelle; Halade, Dipti; Yoo, Si-Eun; Ran, Qitao; Richardson, Arlan

    2010-01-01

    Research highlights: → Development of mouse overexpressing native human HSF1 in all tissues including CNS. → HSF1 overexpression enhances heat shock response at whole-animal and cellular level. → HSF1 overexpression protects from polyglutamine toxicity and favors aggresomes. → HSF1 overexpression enhances proteostasis at the whole-animal and cellular level. -- Abstract: The heat shock response (HSR) is controlled by the master transcriptional regulator heat shock factor 1 (HSF1). HSF1 maintains proteostasis and resistance to stress through production of heat shock proteins (HSPs). No transgenic model exists that overexpresses HSF1 in tissues of the central nervous system (CNS). We generated a transgenic mouse overexpressing full-length non-mutant HSF1 and observed a 2-4-fold increase in HSF1 mRNA and protein expression in all tissues studied of HSF1 transgenic (HSF1 +/0 ) mice compared to wild type (WT) littermates, including several regions of the CNS. Basal expression of HSP70 and 90 showed only mild tissue-specific changes; however, in response to forced exercise, the skeletal muscle HSR was more elevated in HSF1 +/0 mice compared to WT littermates and in fibroblasts following heat shock, as indicated by levels of inducible HSP70 mRNA and protein. HSF1 +/0 cells elicited a significantly more robust HSR in response to expression of the 82 repeat polyglutamine-YFP fusion construct (Q82YFP) and maintained proteasome-dependent processing of Q82YFP compared to WT fibroblasts. Overexpression of HSF1 was associated with fewer, but larger Q82YFP aggregates resembling aggresomes in HSF1 +/0 cells, and increased viability. Therefore, our data demonstrate that tissues and cells from mice overexpressing full-length non-mutant HSF1 exhibit enhanced proteostasis.

  4. Role of capsaicin- and heat-sensitive afferents in stimulation of acupoint-induced pain and analgesia in humans.

    Science.gov (United States)

    Lei, Jing; Ye, Gang; Wu, Jiang-Tao; Pertovaara, Antti; You, Hao-Jun

    2017-09-01

    We investigated role of capsaicin-sensitive afferents within and without the areas of Zusanli (ST36)/Shangjuxu (ST37) acupoints along the stomach (ST) meridian in the perception and modulation of pain assessed by visual analog scale of pain and its distribution rated by subjects, pressure pain threshold (PPT), and heat pain threshold (HPT) in humans. Compared with the treatment of non-acupoint area, capsaicin (100µg/50µl) administered into either ST36 or ST37 acupoint caused the strongest pain intensity and the most extensive pain distribution, followed by rapid onset, bilateral, long-lasting secondary mechanical hyperalgesia and slower onset secondary heat hypoalgesia (1day after the capsaicin treatment). Between treatments of different acupoints, capsaicin administrated into the ST36 acupoint exhibited the stronger pain intensity and more widespread pain distribution compared with the treatment of ST37 acupoint. A period of 30- to 45-min, but not 15-min, 43°C heating-needle stimulation applied to the ST36 acupoint significantly enhanced the HPT, and had no effect on PPT. Upon trapezius muscle pain elicited by the i.m. injection of 5.8% saline, pre-emptive treatment of the contralateral ST36 acupoint with 43°C heating-needle stimulation alleviated the ongoing muscle pain, reduced painful area, and reversed the decrease in HPT. It is suggested that (1) pain elicited from the acupoint and non-acupoint areas differs significantly, which are supposed to be dependent on the different distributions and contributions of capsaicin-sensitive afferents. (2) Non-painful heat stimulation is a valid approach in prevention of ongoing muscle pain with associated post-effects of peripheral and central sensitization. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. In vitro investigation of heat transfer phenomenon in human immature teeth.

    Science.gov (United States)

    Talebi, Maryam; Moghimi, Sahar; Shafagh, Mina; Kalani, Hadi; Mazhari, Fatemeh

    2014-01-01

    Background and aims. Heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp). Geometrical characteristics of immature teeth are different from those of mature teeth. The purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the use of LED light-curing units (LCU). Materials and methods. This study was performed on the second mandibular premolars. This experimental investiga-tion was carried out for recording temperature variations of different sites of tooth and two dimensional finite element models were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the model validation phase. Results. Overall, thermal stimulation for 30 seconds with a low-intensity LED LCU increased the temperature from 28°C to 38°C in IIT (intact immature tooth) and PIT (cavity-prepared immature tooth). When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C. The results of the experimental tests and mathematical modeling illustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth; therefore, further studies are required to determine thermal conductivity of immature teeth.

  6. a-Adrenergic vasoconstrictor responsiveness is preserved in the heated human leg

    DEFF Research Database (Denmark)

    Keller, David M; Sander, Mikael; Stallknecht, Bente Merete

    2010-01-01

    This study tested the hypothesis that passive leg heating attenuates a-adrenergic vasoconstriction within that limb. Femoral blood flow (FBF, femoral artery ultrasound Doppler) and femoral vascular conductance (FVC, FBF/mean arterial blood pressure), as well as calf muscle blood flow (Calf...

  7. Feasibility of measuring thermoregulation during RF heating of the human calf muscle using MR based methods

    NARCIS (Netherlands)

    Simonis, Frank F J; Petersen, Esben T; Lagendijk, JJW; van den Berg, CAT

    PURPOSE: One of the main safety concerns in MR is heating of the subject due to radiofrequency (RF) exposure. Recently was shown that local peak temperatures can reach dangerous values and the most prominent parameter for accurate temperature estimations is thermoregulation. Therefore, the goal of

  8. Human mortality impacts of the 2015 summer heat spells in Slovakia

    Science.gov (United States)

    Výberči, Dalibor; Labudová, Lívia; Eštóková, Milada; Faško, Pavol; Trizna, Milan

    2017-07-01

    In 2015, Central Europe experienced an unusually warm summer season. For a great majority of climatic stations around Slovakia, it had been the warmest summer ever recorded over their entire instrumental observation period. In this study, we investigate the mortality effects of hot days' sequences during that particular summer on the Slovak population. In consideration of the range of available mortality data, the position of 2015 is analysed within the years 1996-2015. Over the given 20-year period, the summer heat spells of 2015 were by far the most severe from a meteorological point of view, and clearly the deadliest with the total of almost 540 excess deaths. In terms of impacts, an extraordinary 10-day August heat spell was especially remarkable. The massive lethal effects of heat would have likely been even more serious under normal circumstances, since the number of premature deaths appeared to be partially reduced due to a non-standard mortality pattern in the first quarter of the year. The heat spells of the extremely warm summer of 2015 in Slovakia are notable not just for their short-term response in mortality. It appears that in a combination with the preceding strong influenza season, they subsequently affected mortality conditions in the country in the following months up until the end of the year. The impacts described above were rather different for selected population subgroups (men and women, the elderly). Both separately and as a part of the annual mortality cycle, the 2015 summer heat spells may represent a particularly valuable source of information for public health.

  9. Radial Pressure Pulse and Heart Rate Variability in Heat- and Cold-Stressed Humans

    Directory of Open Access Journals (Sweden)

    Chin-Ming Huang

    2011-01-01

    Full Text Available This study aims to explore the effects of heat and cold stress on the radial pressure pulse (RPP and heart rate variability (HRV. The subjects immersed their left hand into 45°C and 7°C water for 2 minutes. Sixty healthy subjects (age 25±4 yr; 29 men and 31 women were enrolled in this study. All subjects underwent the supine temperature measurements of the bilateral forearms, brachial arterial blood pressure, HRV and RPP with a pulse analyzer in normothermic conditions, and thermal stresses. The power spectral low-frequency (LF and high-frequency (HF components of HRV decreased in the heat test and increased in the cold test. The heat stress significantly reduced radial augmentation index (AIr (P<.05, but the cold stress significantly increased AIr (P<.01. The spectral energy of RPP did not show any statistical difference in 0∼10 Hz region under both conditions, but in the region of 10∼50 Hz, there was a significant increase (P<.01 in the heat test and a significant decrease in the cold test (P<.01. The changes in AIr induced by heat and cold stress were significantly negatively correlated with the spectral energy in the region of 10∼50 Hz (SE10−50 Hz but not in the region of 0∼10 Hz (SE0−10 Hz. The results demonstrated that the SE10−50 Hz, which only possessed a small percentage in total pulse energy, presented more physiological characteristics than the SE0−10 Hz under the thermal stresses.

  10. Radial Pressure Pulse and Heart Rate Variability in Heat- and Cold-Stressed Humans

    Science.gov (United States)

    Huang, Chin-Ming; Chang, Hsien-Cheh; Kao, Shung-Te; Li, Tsai-Chung; Wei, Ching-Chuan; Chen, Chiachung; Liao, Yin-Tzu; Chen, Fun-Jou

    2011-01-01

    This study aims to explore the effects of heat and cold stress on the radial pressure pulse (RPP) and heart rate variability (HRV). The subjects immersed their left hand into 45°C and 7°C water for 2 minutes. Sixty healthy subjects (age 25 ± 4 yr; 29 men and 31 women) were enrolled in this study. All subjects underwent the supine temperature measurements of the bilateral forearms, brachial arterial blood pressure, HRV and RPP with a pulse analyzer in normothermic conditions, and thermal stresses. The power spectral low-frequency (LF) and high-frequency (HF) components of HRV decreased in the heat test and increased in the cold test. The heat stress significantly reduced radial augmentation index (AIr) (P < .05), but the cold stress significantly increased AIr (P < .01). The spectral energy of RPP did not show any statistical difference in 0 ~ 10 Hz region under both conditions, but in the region of 10 ~ 50 Hz, there was a significant increase (P < .01) in the heat test and a significant decrease in the cold test (P < .01). The changes in AIr induced by heat and cold stress were significantly negatively correlated with the spectral energy in the region of 10 ~ 50 Hz (SE10−50 Hz) but not in the region of 0 ~ 10 Hz (SE0−10 Hz). The results demonstrated that the SE10−50 Hz, which only possessed a small percentage in total pulse energy, presented more physiological characteristics than the SE0−10 Hz under the thermal stresses. PMID:21113292

  11. Heat-Related Deaths in Hot Cities: Estimates of Human Tolerance to High Temperature Thresholds

    Directory of Open Access Journals (Sweden)

    Sharon L. Harlan

    2014-03-01

    Full Text Available In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥65 during the months May–October for years 2000–2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90–97 °F; 32.2‒36.1 °C were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C. Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C and males <65 years (ATmax = 102 °F; 38.9 °C. Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

  12. Temporal summation of heat pain in humans: Evidence supporting thalamocortical modulation.

    Science.gov (United States)

    Tran, Tuan D; Wang, Heng; Tandon, Animesh; Hernandez-Garcia, Luis; Casey, Kenneth L

    2010-07-01

    Noxious cutaneous contact heat stimuli (48 degrees C) are perceived as increasingly painful when the stimulus duration is extended from 5 to 10s, reflecting the temporal summation of central neuronal activity mediating heat pain. However, the sensation of increasing heat pain disappears, reaching a plateau as stimulus duration increases from 10 to 20s. We used functional magnetic resonance imaging (fMRI) in 10 healthy subjects to determine if active central mechanisms could contribute to this psychophysical plateau. During heat pain durations ranging from 5 to 20s, activation intensities in the bilateral orbitofrontal cortices and the activation volume in the left primary (S1) somatosensory cortex correlated only with perceived stimulus intensity and not with stimulus duration. Activation volumes increased with both stimulus duration and perceived intensity in the left lateral thalamus, posterior insula, inferior parietal cortex, and hippocampus. In contrast, during the psychophysical plateau, both the intensity and volume of thalamic and cortical activations in the right medial thalamus, right posterior insula, and left secondary (S2) somatosensory cortex continued to increase with stimulus duration but not with perceived stimulus intensity. Activation volumes in the left medial and right lateral thalamus, and the bilateral mid-anterior cingulate, left orbitofrontal, and right S2 cortices also increased only with stimulus duration. The increased activity of specific thalamic and cortical structures as stimulus duration, but not perceived intensity, increases is consistent with the recruitment of a thalamocortical mechanism that participates in the modulation of pain-related cortical responses and the temporal summation of heat pain. Published by Elsevier B.V.

  13. The heat shock protein response following eccentric exercise in human skeletal muscle is unaffected by local NSAID infusion

    DEFF Research Database (Denmark)

    Mikkelsen, U R; Paulsen, G; Schjerling, P

    2013-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are widely consumed in relation to pain and injuries in skeletal muscle, but may adversely affect muscle adaptation probably via inhibition of prostaglandin synthesis. Induction of heat shock proteins (HSP) represents an important adaptive response...... in muscle subjected to stress, and in several cell types including cardiac myocytes prostaglandins are important in induction of the HSP response. This study aimed to determine the influence of NSAIDs on the HSP response to eccentric exercise in human skeletal muscle. Healthy males performed 200 maximal...

  14. HEATING AND ULTRAVIOLET LIGHT ACTIVATE ANTI-STRESS GENE FUNCTIONS IN HUMANS

    Directory of Open Access Journals (Sweden)

    Victor Fadeevitch Semenkov

    2015-07-01

    Full Text Available All types of cell stress are accompanied by the activation of anti-stress genes that can suppress ROS synthesis. We hypothesized that different environmental factors would affect organisms through the activation of anti-stress genes by autologous serum (AS proteins, followed by the synthesis of molecules that increase cell resistance to oxidative stress. The goal of this work was to study the influence of AS on ROS production by peripheral blood neutrophils isolated from donors in different age groups. Neutrophils were isolated from 59 donors (38-94 years old. AS was heated at 100˚C for 30 sec. or irradiated by ultraviolet light (UV at 200-280 nm and 8 W for 10 min. Neutrophils were exposed to heat shock at 42˚C for 1 min. (short-term heating stress or 43˚C for 10 min., followed by the determination of the chemiluminescence reaction induced by zymosan. AS can increase or decrease ROS production by neutrophils depending on the structure of the proteins in the serum; these structures can be changed by heating or UV treatment and the temperature of their interaction (4˚C or 37˚C. We propose that the effect of environmental factors on AS proteins can cause an adverse increase in oxidative stress levels due to the functional reduction of anti-stress genes. We found a negative correlation between the quantity of intracellular Hsp70 and levels of intracellular ROS production following 10 minutes of heat shock at 43°C. Short-term heating stress (1 minute at 42°C was followed by a prominent reduction in ROS production. This effect may be a result of the impact of the hormone adrenaline on the functions of anti-stress genes. Indeed, the same effect was observed after treatment of the neutrophils with adrenaline at concentrations of 10-4 M and 10-5 M. In contrast, dexamethasone from the other stress hormone group did not evoke the same effect at the same concentrations.

  15. In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth

    OpenAIRE

    Maryam Talebi; Sahar Moghimi; Mina Shafagh; Hadi Kalani; Fatemeh Mazhari

    2014-01-01

    Background and aims. Heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp). Geometrical characteristics of immature teeth are different from those of mature teeth. The purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the use of LED light-curing units (LCU). Materials and methods. This study was performed on the second ...

  16. In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth

    Directory of Open Access Journals (Sweden)

    Maryam Talebi

    2014-12-01

    Full Text Available Background and aims. Heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp. Geometrical characteristics of immature teeth are different from those of mature teeth. The purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the use of LED light-curing units (LCU. Materials and methods. This study was performed on the second mandibular premolars. This experimental investiga-tion was carried out for recording temperature variations of different sites of tooth and two dimensional finite element mod-els were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the mod-el validation phase. Results. Overall, thermal stimulation for 30 seconds with a low-intensity LED LCU increased the temperature from 28°C to 38°C in IIT (intact immature tooth and PIT (cavity-prepared immature tooth. When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C. The results of the experimental tests and mathematical modeling il-lustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth; therefore, further studies are re-quired to determine thermal conductivity of immature teeth.

  17. Intradermal administration of magnesium sulphate and magnesium chloride produces hypesthesia to mechanical but hyperalgesia to heat stimuli in humans

    Directory of Open Access Journals (Sweden)

    Ikemoto Tatsunori

    2009-08-01

    Full Text Available Abstract Background Although magnesium ions (Mg2+ are known to display many similar features to other 2+ charged cations, they seem to have quite an important and unique role in biological settings, such as NMDA blocking effect. However, the role of Mg2+ in the neural transmission system has not been studied as sufficiently as calcium ions (Ca2+. To clarify the sensory effects of Mg2+ in peripheral nervous systems, sensory changes after intradermal injection of Mg2+ were studied in humans. Methods Magnesium sulphate, magnesium chloride and saline were injected into the skin of the anterior region of forearms in healthy volunteers and injection-induced irritating pain ("irritating pain", for short, tactile sensation, tactile pressure thresholds, pinch-pain changes and intolerable heat pain thresholds of the lesion were monitored. Results Flare formation was observed immediately after magnesium sulphate or magnesium chloride injection. We found that intradermal injections of magnesium sulphate and magnesium chloride transiently caused irritating pain, hypesthesia to noxious and innocuous mechanical stimulations, whereas secondary hyperalgesia due to mechanical stimuli was not observed. In contrast to mechanical stimuli, intolerable heat pain-evoking temperature was significantly decreased at the injection site. In addition to these results, spontaneous pain was immediately attenuated by local cooling. Conclusion Membrane-stabilizing effect and peripheral NMDA-blocking effect possibly produced magnesium-induced mechanical hypesthesia, and extracellular cation-induced sensitization of TRPV1 channels was thought to be the primary mechanism of magnesium-induced heat hyperalgesia.

  18. Mechano-sensitive nociceptors are required to detect heat pain thresholds and cowhage itch in human skin.

    Science.gov (United States)

    Weinkauf, B; Dusch, M; van der Ham, J; Benrath, J; Ringkamp, M; Schmelz, M; Rukwied, R

    2016-02-01

    Mechano-sensitive and mechano-insensitive C-nociceptors in human skin differ in receptive field sizes and electrical excitation thresholds, but their distinct functional roles are yet unclear. After blocking the lateral femoral cutaneous nerve (NCFL) in eight healthy male subjects (3-mL Naropin(®) 1%), we mapped the skin innervation territory being anaesthetic to mechanical pin prick but sensitive to painful transcutaneous electrical stimuli. Such 'differentially anaesthetic zones' indicated that the functional innervation with mechano-sensitive nociceptors was absent but the innervation with mechano-insensitive nociceptors remained intact. In these areas, we explored heat pain thresholds, low pH-induced pain, cowhage- and histamine-induced itch, and axon reflex flare. In differentially anaesthetic skin, heat pain thresholds were above the cut-off of 50°C (non-anaesthetized skin 47 ± 0.4°C). Pain ratings to 30 μL pH 4 injections were reduced compared to non-anaesthetized skin (48 ± 9 vs. 79 ± 6 VAS; p pain. The mechano-sensitive nociceptors are crucial for cowhage-induced itch and for the assessment of heat pain thresholds. © 2015 European Pain Federation - EFIC®

  19. Anti-inflammatory heat shock protein 70 genes are positively associated with human survival

    DEFF Research Database (Denmark)

    Singh, Ripudaman; Kølvraa, Steen; Bross, Peter Gerd

    2010-01-01

    A positive relationship between stress tolerance and longevity has been observed in several model systems. That the same correlation is applicable in humans and that it may be open to experimental manipulation for extending human lifespan requires studies on association of stress genes with longe......A positive relationship between stress tolerance and longevity has been observed in several model systems. That the same correlation is applicable in humans and that it may be open to experimental manipulation for extending human lifespan requires studies on association of stress genes...... the opportunity to perform survival analysis on these subjects. Haplotype relative risk, and genotype relative risk were calculated to measure the effects of haplotypes and genotypes on human survival in a sex-specific manner. A significant association of HSPA1A-AA (RR=3.864; p=0.016) and HSPA1B-AA (RR=2.764; p=0...

  20. The effect of heat- or ultra violet ozone-treatment of titanium on complement deposition from human blood plasma.

    Science.gov (United States)

    Linderbäck, Paula; Harmankaya, Necati; Askendal, Agneta; Areva, Sami; Lausmaa, Jukka; Tengvall, Pentti

    2010-06-01

    Titanium (Ti) is a well known metallic biomaterial extensively used in dental, orthopaedic-, and occasionally also in blood contacting applications. It integrates well to bone and soft tissues, and is shown upon blood plasma contact to activate the intrinsic pathway of coagulation and bind complement factor 3b. The material properties depend largely on those of the nm-thick dense layer of TiO(2) that becomes rapidly formed upon contact with air and water. The spontaneously formed amorphous Ti-oxide has a pzc approximately 5-6 and its water solubility is at the order of 1-2 micromolar. It is often subjected to chemical- and heat treatments in order to increase the anatase- and rutile crystallinity, to modify the surface topography and to decrease the water solubility. In this work, we prepared sol-gel derived titanium and smooth PVD titanium surfaces, and analysed their oxide and protein deposition properties in human blood plasma before and after annealing at 100-500 degrees C or upon UVO-treatment for up to 96 hours. The blood plasma results show that complement deposition vanished irreversibly after heat treatment at 250-300 degrees C for 30 minutes or after UVO exposure for 24 hours or longer. XPS and infrared spectroscopy indicated change of surface water/hydroxyl binding upon the heat- and UVO treatments, and increased Ti oxidation. XRD analysis confirmed an increased crystallinity and both control (untreated) and annealed smooth titanium displayed low XRD-signals indicating some nanocrystallinity, with predominantly anatase phase. The current results show that the behaviour of titanium dioxide in blood contact can be controlled through relatively simple means, such as mild heating and illumination in UV-light, which both likely irreversibly change the stoichiometry and structure of the outmost layers of titanium dioxide and its OH/H(2)O binding characteristics. (c) 2010 Elsevier Ltd. All rights reserved.

  1. Review on modeling heat transfer and thermoregulatory responses in human body.

    Science.gov (United States)

    Fu, Ming; Weng, Wenguo; Chen, Weiwang; Luo, Na

    2016-12-01

    Several mathematical models of human thermoregulation have been developed, contributing to a deep understanding of thermal responses in different thermal conditions and applications. In these models, the human body is represented by two interacting systems of thermoregulation: the controlling active system and the controlled passive system. This paper reviews the recent research of human thermoregulation models. The accuracy and scope of the thermal models are improved, for the consideration of individual differences, integration to clothing models, exposure to cold and hot conditions, and the changes of physiological responses for the elders. The experimental validated methods for human subjects and manikin are compared. The coupled method is provided for the manikin, controlled by the thermal model as an active system. Computational Fluid Dynamics (CFD) is also used along with the manikin or/and the thermal model, to evaluate the thermal responses of human body in various applications, such as evaluation of thermal comfort to increase the energy efficiency, prediction of tolerance limits and thermal acceptability exposed to hostile environments, indoor air quality assessment in the car and aerospace industry, and design protective equipment to improve function of the human activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The role of the molecular chaperone heat shock protein A2 (HSPA2 in regulating human sperm-egg recognition

    Directory of Open Access Journals (Sweden)

    Brett Nixon

    2015-01-01

    Full Text Available One of the most common lesions present in the spermatozoa of human infertility patients is an idiopathic failure of sperm-egg recognition. Although this unique cellular interaction can now be readily by-passed by assisted reproductive strategies such as intracytoplasmic sperm injection (ICSI, recent large-scale epidemiological studies have encouraged the cautious use of this technology and highlighted the need for further research into the mechanisms responsible for defective sperm-egg recognition. Previous work in this field has established that the sperm domains responsible for oocyte interaction are formed during spermatogenesis prior to being dynamically modified during epididymal maturation and capacitation in female reproductive tract. While the factors responsible for the regulation of these sequential maturational events are undoubtedly complex, emerging research has identified the molecular chaperone, heat shock protein A2 (HSPA2, as a key regulator of these events in human spermatozoa. HSPA2 is a testis-enriched member of the 70 kDa heat shock protein family that promotes the folding, transport, and assembly of protein complexes and has been positively correlated with in vitro fertilization (IVF success. Furthermore, reduced expression of HSPA2 from the human sperm proteome leads to an impaired capacity for cumulus matrix dispersal, sperm-egg recognition and fertilization following both IVF and ICSI. In this review, we consider the evidence supporting the role of HSPA2 in sperm function and explore the potential mechanisms by which it is depleted in the spermatozoa of infertile patients. Such information offers novel insights into the molecular mechanisms governing sperm function.

  3. Heat Shock Protein 70 Enhances Mucosal Immunity against Human Norovirus When Coexpressed from a Vesicular Stomatitis Virus Vector

    Science.gov (United States)

    Ma, Yuanmei; Duan, Yue; Wei, Yongwei; Liang, Xueya; Niewiesk, Stefan; Oglesbee, Michael

    2014-01-01

    ABSTRACT Human norovirus (NoV) accounts for 95% of nonbacterial gastroenteritis worldwide. Currently, there is no vaccine available to combat human NoV as it is not cultivable and lacks a small-animal model. Recently, we demonstrated that recombinant vesicular stomatitis virus (rVSV) expressing human NoV capsid protein (rVSV-VP1) induced strong immunities in mice (Y. Ma and J. Li, J. Virol. 85:2942–2952, 2011). To further improve the safety and efficacy of the vaccine candidate, heat shock protein 70 (HSP70) was inserted into the rVSV-VP1 backbone vector. A second construct was generated in which the firefly luciferase (Luc) gene was inserted in place of HSP70 as a control for the double insertion. The resultant recombinant viruses (rVSV-HSP70-VP1 and rVSV-Luc-VP1) were significantly more attenuated in cell culture and viral spread in mice than rVSV-VP1. At the inoculation dose of 1.0 × 106 PFU, rVSV-HSP70-VP1 triggered significantly higher vaginal IgA than rVSV-VP1 and significantly higher fecal and vaginal IgA responses than rVSV-Luc-VP1, although serum IgG and T cell responses were similar. At the inoculation dose of 5.0 × 106 PFU, rVSV-HSP70-VP1 stimulated significantly higher T cell, fecal, and vaginal IgA responses than rVSV-VP1. Fecal and vaginal IgA responses were also significantly increased when combined vaccination of rVSV-VP1 and rVSV-HSP70 was used. Collectively, these data indicate that (i) insertion of an additional gene (HSP70 or Luc) into the rVSV-VP1 backbone further attenuates the VSV-based vaccine in vitro and in vivo, thus improving the safety of the vaccine candidate, and (ii) HSP70 enhances the human NoV-specific mucosal and T cell immunities triggered by a VSV-based human NoV vaccine. IMPORTANCE Human norovirus (NoV) is responsible for more than 95% of acute nonbacterial gastroenteritis worldwide. Currently, there is no vaccine for this virus. Development of a live attenuated vaccine for human NoV has not been possible because it is

  4. Numerical modeling of heat and mass transfer in the human eye under millimeter wave exposure.

    Science.gov (United States)

    Karampatzakis, Andreas; Samaras, Theodoros

    2013-05-01

    Human exposure to millimeter wave (MMW) radiation is expected to increase in the next several years. In this work, we present a thermal model of the human eye under MMW illumination. The model takes into account the fluid dynamics of the aqueous humor and predicts a frequency-dependent reversal of its flow that also depends on the incident power density. The calculated maximum fluid velocity in the anterior chamber and the temperature rise at the corneal apex are reported for frequencies from 40 to 100 GHz and different values of incident power density. Copyright © 2013 Wiley Periodicals, Inc.

  5. Modeling and simulation of heat distribution in human skin caused by laser irradiation

    NARCIS (Netherlands)

    Luan, Y.; Dams, S.D.

    2009-01-01

    Study of light-based skin rejuvenation needs prospective insights of mechanism of laser tissue interaction. A well-built model plays a key role in predicting temperature distribution in human skin exposed to laser irradiation. Therefore, it not only provides guidance for in vitro experiment, but

  6. Regional relation between skin blood flow and sweating to passive heating and local administration of acetylcholine in young, healthy humans.

    Science.gov (United States)

    Smith, Caroline J; Kenney, W Larry; Alexander, Lacy M

    2013-04-01

    Regional variation in sweating over the human body is widely recognized yet variation in vasomotor responses and mechanisms causing this variation remain unclear. This study aimed to explore the relation between regional sweating rates (RSR) and skin blood flow (SkBF) responses to thermal and pharmacological stimuli in young, healthy subjects. In nine subjects (23 ± 3 yr), intradermal microdialysis (MD) probes were inserted into the ventral forearm, abdomen, thigh, and lower back and perfused with lactated Ringer solution. RSR over each MD membrane were measured using ventilated capsules with a laser Doppler probe housed in each capsule for measurement of red cell flux (laser Doppler flux, LDF) as an index of SkBF. Subjects completed a whole body heating protocol to 1°C rise in oral temperature and an acetylcholine dose response (ACh 1 × 10(-7)-0.1 M; mean skin temperature 34°C). Maximal LDF were obtained at the end of both protocols (50 mM sodium nitroprusside).During heating RSR varied among sites (P back versus other sites (P back: r = 0.86 ± 0.04) but not latter stages of heating. No differences in RSR (P = 0.160) or SkBF (LDF, P = 0.841) were observed between sites during ACh perfusion. Taken together, these data suggest that increases in SkBF are necessary to initiate and increase sweating, but further rises in RSR are not fully dependent on SkBF in a dose-response manner. Furthermore, RSR cannot be explained by cholinergic sensitivity or variation in SkBF.

  7. Frequency of Extreme Heat Event as a Surrogate Exposure Metric for Examining the Human Health Effects of Climate Change.

    Directory of Open Access Journals (Sweden)

    Crystal Romeo Upperman

    Full Text Available Epidemiological investigation of the impact of climate change on human health, particularly chronic diseases, is hindered by the lack of exposure metrics that can be used as a marker of climate change that are compatible with health data. Here, we present a surrogate exposure metric created using a 30-year baseline (1960-1989 that allows users to quantify long-term changes in exposure to frequency of extreme heat events with near unabridged spatial coverage in a scale that is compatible with national/state health outcome data. We evaluate the exposure metric by decade, seasonality, area of the country, and its ability to capture long-term changes in weather (climate, including natural climate modes. Our findings show that this generic exposure metric is potentially useful to monitor trends in the frequency of extreme heat events across varying regions because it captures long-term changes; is sensitive to the natural climate modes (ENSO events; responds well to spatial variability, and; is amenable to spatial/temporal aggregation, making it useful for epidemiological studies.

  8. Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pennypacker, Carl R.; Perelson, A.S.; Nys, N.; Nelson, G.; Sessler, D.I.

    1993-12-15

    Temperatures as low as 42 C, maintained for a little as 25 minutes, inactivate {approx}25% of HIV. Furthermore, human immunodeficiency virus (HIV)-infected T-cells are more sensitive to heat than healthy lymphocytes and susceptibility increases when the cells are pre-sensitized by exposure to tumor necrosis factor. Thus, induction of a whole-body hyperthermia, or hyperthermia specifically limited to tissues having a high viral load, are potential antiviral therapies for acquired immunodeficiency disease (AIDS). Accordingly, we incorporated therapeutic hyperthermia into an existing mathematical model which evaluates the interaction between HIV and CD4{sup +} T cells. Given the assumptions and limitations of this model, the results indicate that a daily therapy, reducing the population of actively infected cells by 40% or infectious virus by 50%, would effectively reverse the depletion of T cells. In contrast, a daily reduction of 20% of either actively infected cells or infectious virus would have a marginal effect. However, reduction by 20% of both actively infected cells and infectious virus could restore T cell numbers, assuming that permanent damage had not been inflicted on the thymus. Whole-body hyperthermia seems unlikely to be clinically useful, unless it can be induced non-invasively without general anesthesia. In contrast, heating directed specifically to areas of viral concentration may be effective and have a suitable risk/benefit ratio.

  9. High Level Soluble Expression and ATPase Characterization of Human Heat Shock Protein GRP78.

    Science.gov (United States)

    Wu, Shuang; Zhang, Hongpeng; Luo, Miao; Chen, Ke; Yang, Wei; Bai, Lei; Huang, Ailong; Wang, Deqiang

    2017-02-01

    Human GRP78 has been shown to promote cancer progression and is regarded as a novel target for anticancer drugs. However, generation of recombinant full-length GRP78 remains challenging. This report demonstrates that E. coli autoinduction is an excellent method for the preparation of active recombinant GRP78 protein. The final yield was approximately 50 mg/liter of autoinduction culture. Gel-filtration experiments confirmed that the chaperone is a monomer. The purified human GRP78 catalyzed the conversion of ATP to ADP without requiring metal ions as cofactors. Three mutants, T38A, T229A, and S300A, exhibited much lower activity than wild-type GRP78, indicating that the active sites of the ATPase are located at the negatively charged cavity. Three mutants in the negatively charged cavity region dramatically reduced GRP78 activity, further confirming the region as the site of ATPase activity.

  10. Numerical model of heat transfer in the human eye with consideration of fluid dynamics of the aqueous humour

    Energy Technology Data Exchange (ETDEWEB)

    Karampatzakis, Andreas; Samaras, Theodoros, E-mail: theosama@auth.g [Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2010-10-07

    In this work we present a new 3D numerical model for heat transfer in the human eye, which takes into account the aqueous humour flow in the anterior chamber. We show that consideration of this phenomenon in the calculations alters the temperature distribution on the corneal and lens surfaces, without, however, noticeably changing their absolute values. The most notable effect is that the coolest area of the cornea moves at a point of 2 mm inferior to its geometric centre. The maximum velocity of the fluid in the anterior chamber was found to be 3.36 x 10{sup -4} m s{sup -1}. The effect of the flow on displacing the cool area of the corneal surface temperature is counterbalanced by assuming anisotropic thermal conductivity. The model was implemented in the case of an artificial intraocular lens to show the resulting temperature variations.

  11. Numerical model of heat transfer in the human eye with consideration of fluid dynamics of the aqueous humour.

    Science.gov (United States)

    Karampatzakis, Andreas; Samaras, Theodoros

    2010-10-07

    In this work we present a new 3D numerical model for heat transfer in the human eye, which takes into account the aqueous humour flow in the anterior chamber. We show that consideration of this phenomenon in the calculations alters the temperature distribution on the corneal and lens surfaces, without, however, noticeably changing their absolute values. The most notable effect is that the coolest area of the cornea moves at a point of 2 mm inferior to its geometric centre. The maximum velocity of the fluid in the anterior chamber was found to be 3.36 × 10(-4) m s(-1). The effect of the flow on displacing the cool area of the corneal surface temperature is counterbalanced by assuming anisotropic thermal conductivity. The model was implemented in the case of an artificial intraocular lens to show the resulting temperature variations.

  12. Numerical model of heat transfer in the human eye with consideration of fluid dynamics of the aqueous humour

    International Nuclear Information System (INIS)

    Karampatzakis, Andreas; Samaras, Theodoros

    2010-01-01

    In this work we present a new 3D numerical model for heat transfer in the human eye, which takes into account the aqueous humour flow in the anterior chamber. We show that consideration of this phenomenon in the calculations alters the temperature distribution on the corneal and lens surfaces, without, however, noticeably changing their absolute values. The most notable effect is that the coolest area of the cornea moves at a point of 2 mm inferior to its geometric centre. The maximum velocity of the fluid in the anterior chamber was found to be 3.36 x 10 -4 m s -1 . The effect of the flow on displacing the cool area of the corneal surface temperature is counterbalanced by assuming anisotropic thermal conductivity. The model was implemented in the case of an artificial intraocular lens to show the resulting temperature variations.

  13. [Heat-induced symptomatology in human teeth. An in-vitro study].

    Science.gov (United States)

    Baldissara, P; Bortolini, S; Papale, G; Scotti, R

    1998-09-01

    Various dental procedures can generate thermal increase in the dental pulp, in particular if they are incorrectly conducted. In literature the pulp cells are considered very heat sensitive. In this study the symptomatological response of patients during and after thermal administration to the dental crown has been recorded. The analysis of the symptomatology was used as an indication for the definition of the threshold of thermal damage. Twelve healthy teeth of four patients programmed for extraction were subdivided into six couples of homologous teeth. One tooth out of each couple was used for the immediate in vivo recording of the symptoms; the other, once extracted, was used to determine the thermal increase applied through the insertion of a thermocouple sensor. In each couple of teeth the thermal stimulus was equal. The average thermal increase was 11.2 degrees C. Pain starts at temperatures ranging from 39.5 to 50.4 degrees C with an average of 44.6 degrees C. This agrees with classical physiological data which reports the threshold of pain at 45 degrees C. The threshold of pain registered suggests that at temperatures below 44.6 degrees C damage to the dental pulp is improbable, at least in healthy teeth. The limit of 45 degrees C appears, therefore, to be a probable safe threshold, contrary to what is reported in literature.

  14. Cerebral responses to exercise and the influence of heat stress in human fatigue.

    Science.gov (United States)

    Robertson, Caroline V; Marino, Frank E

    2017-01-01

    There are a number of mechanisms thought to be responsible for the onset of fatigue during exercise-induced hyperthermia. A greater understanding of the way in which fatigue develops during exercise could be gleaned from the studies which have examined the maintenance of cerebral blood flow through the process of cerebral autoregulation. Given that cerebral blood flow is a measure of the cerebral haemodynamics, and might reflect a level of brain activation, it is useful to understand the implications of this response during exercise and in the development of fatigue. It is known that cerebral blood flow is significantly altered under certain conditions such as altitude and exacerbated during exercise induced - hyperthermia. In this brief review we consider the processes of cerebral autoregulation predominantly through the measurement of cerebral blood flow and contrast these responses between exercise undertaken in normothermic versus heat stress conditions in order to draw some conclusions about the role cerebral blood flow might play in determining fatigue. Copyright © 2016. Published by Elsevier Ltd.

  15. A review of heat transfer in human tooth--experimental characterization and mathematical modeling.

    Science.gov (United States)

    Lin, Min; Xu, Feng; Lu, Tian Jian; Bai, Bo Feng

    2010-06-01

    With rapid advances in modern dentistry, high-energy output instruments (e.g., dental lasers and light polymerizing units) are increasingly employed in dental surgery for applications such as laser assisted tooth ablation, bleaching, hypersensitivity treatment and polymerization of dental restorative materials. Extreme high temperature occurs within the tooth during these treatments, which may induce tooth thermal pain (TTP) sensation. Despite the wide application of these dental treatments, the underlying mechanisms are far from clear. Therefore, there is an urgent need to better understand heat transfer (HT) process in tooth, thermally induced damage of tooth, and the corresponding TTP. This will enhance the design and optimization of clinical treatment strategies. This paper presents the state-of-the-art of the current understanding on HT in tooth, with both experimental study and mathematical modeling reviewed. Limitations of the current experimental and mathematical methodologies are discussed and potential solutions are suggested. Interpretation of TTP in terms of thermally stimulated dentinal fluid flow is also discussed. Copyright (c) 2010 Academy of Dental Materials. All rights reserved.

  16. Caribbean Heat Threatens Health, Well-being and the Future of Humanity.

    Science.gov (United States)

    Macpherson, Cheryl C; Akpinar-Elci, Muge

    2015-07-01

    Climate change has substantial impacts on public health and safety, disease risks and the provision of health care, with the poor being particularly disadvantaged. Management of the associated health risks and changing health service requirements requires adequate responses at local levels. Health-care providers are central to these responses. While climate change raises ethical questions about its causes, impacts and social justice, medicine and bioethics typically focus on individual patients and research participants rather than these broader issues. We broaden this focus by examining awareness among health-care providers in the Caribbean region, where geographic and socioeconomic features pose particular vulnerabilities to climate change. In focus groups, Caribbean providers described rises in mosquito-borne, flood-related, heat-related, respiratory and mental illnesses, and attributed these to local impacts of climate change. Their discussions showed that the significance of these impacts differs in different Caribbean nations, raising policy and social justice questions. Bioethics and public health ethics are situated to frame, inform and initiate public and policy dialog about values and scientific evidence associated with climate change. We urge readers to initiate such dialog within their own institutions about the context-dependent nature of the burdens of climate change, and values and policies that permit it to worsen.

  17. The heat shock protein 90 inhibitor 17-AAG suppresses growth and induces apoptosis in human cholangiocarcinoma cells.

    Science.gov (United States)

    Zhang, Jianjun; Zheng, Zhichao; Zhao, Yan; Zhang, Tao; Gu, Xiaohu; Yang, Wei

    2013-11-01

    The aim of this study was to investigate the effects of 17-Allylamino-17-demethoxygeldanamycin (17-AAG), a heat shock protein 90 (HSP90) inhibitor, on the proliferation, cell cycle, and apoptosis of human cholangiocarcinoma (CCA) cells. Cell proliferation and cell cycle distribution were measured by the MTT assay and flow cytometry analysis, respectively. Induction of apoptosis was determined by flow cytometry and Hoechst staining. The expressions of cleaved poly ADP-ribose polymerase (PARP), Bcl-2, Survivin, and Cyclin B1 were detected by Western blot analysis. The activity of caspase-3 was also examined. We found that 17-AAG inhibited cell growth and induced G2/M cell cycle arrest and apoptosis in CCA cells together with the down-regulation of Bcl-2, Survivin and Cyclin B1, and the up-regulation of cleaved PARP. Moreover, increased caspase-3 activity was also observed in CCA cells treated with 17-AAG. In conclusion, our data suggest that the inhibition of HSP90 function by 17-AAG may provide a promising therapeutic strategy for the treatment of human CCA.

  18. Relationship between muscle water and glycogen recovery after prolonged exercise in the heat in humans.

    Science.gov (United States)

    Fernández-Elías, Valentín E; Ortega, Juan F; Nelson, Rachael K; Mora-Rodriguez, Ricardo

    2015-09-01

    It is usually stated that glycogen is stored in human muscle bound to water in a proportion of 1:3 g. We investigated this proportion in biopsy samples during recovery from prolonged exercise. On two occasions, nine aerobically trained subjects ([Formula: see text] = 54.4 ± 1.05 mL kg(-1) min(-1); mean ± SD) dehydrated 4.6 ± 0.2 % by cycling 150 min at 65 % [Formula: see text] in a hot-dry environment (33 ± 4 °C). One hour after exercise subjects ingested 250 g of carbohydrates in 400 mL of water (REHLOW) or the same syrup plus water to match fluid losses (i.e., 3170 ± 190 mL; REHFULL). Muscle biopsies were obtained before, 1 and 4 h after exercise. In both trials muscle water decreased from pre-exercise similarly by 13 ± 6 % and muscle glycogen by 44 ± 10 % (P recovery, glycogen levels were similar in both trials (79 ± 15 and 87 ± 18 g kg(-1) dry muscle; P = 0.20) while muscle water content was higher in REHFULL than in REHLOW (3814 ± 222 vs. 3459 ± 324 g kg(-1) dm, respectively; P recovery ratio 1:3) while during REHFULL this ratio was higher (1:17). Our findings agree with the long held notion that each gram of glycogen is stored in human muscle with at least 3 g of water. Higher ratios are possible (e.g., during REHFULL) likely due to water storage not bound to glycogen.

  19. Skin blood flow and local temperature independently modify sweat rate during passive heat stress in humans.

    Science.gov (United States)

    Wingo, Jonathan E; Low, David A; Keller, David M; Brothers, R Matthew; Shibasaki, Manabu; Crandall, Craig G

    2010-11-01

    Sweat rate (SR) is reduced in locally cooled skin, which may result from decreased temperature and/or parallel reductions in skin blood flow. The purpose of this study was to test the hypotheses that decreased skin blood flow and decreased local temperature each independently attenuate sweating. In protocols I and II, eight subjects rested supine while wearing a water-perfused suit for the control of whole body skin and internal temperatures. While 34°C water perfused the suit, four microdialysis membranes were placed in posterior forearm skin not covered by the suit to manipulate skin blood flow using vasoactive agents. Each site was instrumented for control of local temperature and measurement of local SR (capacitance hygrometry) and skin blood flow (laser-Doppler flowmetry). In protocol I, two sites received norepinephrine to reduce skin blood flow, while two sites received Ringer solution (control). All sites were maintained at 34°C. In protocol II, all sites received 28 mM sodium nitroprusside to equalize skin blood flow between sites before local cooling to 20°C (2 sites) or maintenance at 34°C (2 sites). In both protocols, individuals were then passively heated to increase core temperature ~1°C. Both decreased skin blood flow and decreased local temperature attenuated the slope of the SR to mean body temperature relationship (2.0 ± 1.2 vs. 1.0 ± 0.7 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased skin blood flow, P = 0.01; 1.2 ± 0.9 vs. 0.07 ± 0.05 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased local temperature, P = 0.02). Furthermore, local cooling delayed the onset of sweating (mean body temperature of 37.5 ± 0.4 vs. 37.6 ± 0.4°C, P = 0.03). These data demonstrate that local cooling attenuates sweating by independent effects of decreased skin blood flow and decreased local skin temperature.

  20. Analysis and simulation of heat transfer in human tooth during the curing of orthodontic appliance and food ingestion

    Directory of Open Access Journals (Sweden)

    J Velazquez-Lopez

    2016-01-01

    Full Text Available The aim of this study was to analyze and simulate the heat transfer in the human tooth undergoing fixed orthodontic appliances and food intake. An in vivo representative mathematic model of a layered thermographic profile was developed during the LED curing of Gemini bracket 0.022 in slot (conventional ligating system and Transbond XT adhesive. The characterization of the layered thermic response allowed to identify if during the LED curing process, according to manufacturer's specification (light curing unit, adhesive can induce pulpar necrosis. The profile's thermographic model was the simulation basis of many conditions such as food intake, due to in vivo metrology is affected by the impossibility of a correct apparatus position and the physiologic function of the oral cavity which is exposed to uncontrollable temperature changes. The metrology was carried out with a T-440 thermographic camera during LED curing bracket, using a LED curing light (Elipar S10 placed at 3 ± 1 mm for 5 s at each mesial and distal surface. The thermography outcomes were analyzed in the FLIR Tools Software, Microsoft Excel 2013 and SPSS 22. To adjust the mathematic model error, in vitro studies were performed on third molars for the purpose of realizing extreme exposition temperature condition tests caused by the LED curing unit without jeopardizing the human tooth vitality as would it be on in vivo experimentation. The bracket curing results according to manufacturer's conditions reached 39°C in vivo temperatures and 47°C on in vitro tests, which does not jeopardize human tooth vitality as said by previous researches, although, an LED curing precise protocol established by the manufacturer's LED curing light is sustained.

  1. Human Thermal Comfort and Heat Removal Efficiency for Ventilation Variants in Passenger Cars

    Directory of Open Access Journals (Sweden)

    Saboora Khatoon

    2017-10-01

    Full Text Available The realization of a comfortable thermal environment with low energy consumption and improved ventilation in a car has become the aim of manufacturers in recent decades. Novel ventilation concepts with more flexible cabin usage and layouts are appealing owing to their potential for improving passenger comfort and driving power. In this study, three variant ventilation concepts are investigated and their performance is compared with respect to energy efficiency and human comfort of the driver and passenger in front and a child in the rear compartment. FLUENT 16.0, a commercial three-dimensional (3D software, are used for the simulation. A surface-to-surface radiation model is applied under transient conditions for a car parked in summer conditions with its engine in the running condition. The results for the standard Fanger’s model and modified Fanger’s model are analyzed, discussed, and compared for the driver, passenger, and child. The modified Fanger’s model determines the thermal sensation on the basis of mean arterial pressure.

  2. Analysis of human factors on urban heat island and simulation of urban thermal environment in Lanzhou city, China

    Science.gov (United States)

    Pan, Jinghu

    2015-01-01

    Urban heat island (UHI) effect is a global phenomenon caused by urbanization. Because of the number and complexity of factors contributing to the urban thermal environment, traditional statistical methods are insufficient for acquiring data and analyzing the impact of human activities on the thermal environment, especially for identifying which factors are dominant. The UHI elements were extracted using thermal infrared remote sensing data to retrieve the land surface temperatures of Lanzhou city, and then adopting an object-oriented fractal net evolution approach to create an image segmentation of the land surface temperature (LST). The effects of urban expansion on the urban thermal environment were quantitatively analyzed. A comprehensive evaluation system of the urban thermal environment was constructed, the spatial pattern of the urban thermal environment in Lanzhou was assessed, and principal influencing factors were identified using spatial principal component analysis (SPCA) and multisource spatial data. We found that in the last 20 years, the UHI effect in Lanzhou city has been strengthened, as the UHI ratio index has increased from 0.385 in 1993 to 0.579 in 2001 and to 0.653 in 2011. The UHI expansion had a spatiotemporal consistency with the urban expansion. The four major factors that affect the spatial pattern of the urban thermal environment in Lanzhou can be ranked in the following order: landscape configuration, anthropogenic heat release, urban construction, and gradient from man-made to natural land cover. These four together accounted for 91.27% of the variance. A linear model was thus successfully constructed, implying that SPCA is helpful in identifying major contributors to UHI. Regression analysis indicated that the instantaneous LST and the simulated thermal environment have a good linear relationship, the correlation coefficient between the two reached 0.8011, highly significant at a confidence level of 0.001.

  3. Critical role of heat shock protein 27 in bufalin-induced apoptosis in human osteosarcomas: a proteomic-based research.

    Directory of Open Access Journals (Sweden)

    Xian-biao Xie

    Full Text Available Bufalin is the primary component of the traditional Chinese herb "Chan Su". Evidence suggests that this compound possesses potent anti-tumor activities, although the exact molecular mechanism(s is unknown. Our previous study showed that bufalin inhibited growth of human osteosarcoma cell lines U2OS and U2OS/MTX300 in culture. Therefore, this study aims to further clarify the in vitro and in vivo anti-osteosarcoma effects of bufalin and its molecular mechanism of action. We found bufalin inhibited both methotrexate (MTX sensitive and resistant human osteosarcoma cell growth and induced G2/M arrest and apoptosis. Using a comparative proteomics approach, 24 differentially expressed proteins following bufalin treatment were identified. In particular, the level of an anti-apoptotic protein, heat shock protein 27 (Hsp27, decreased remarkably. The down-regulation of Hsp27 and alterations of its partner signaling molecules (the decrease in p-Akt, nuclear NF-κB p65, and co-immunoprecipitated cytochrome c/Hsp27 were validated. Hsp27 over-expression protected against bufalin-induced apoptosis, reversed the dephosphorylation of Akt and preserved the level of nuclear NF-κB p65 and co-immunoprecipitated Hsp27/cytochrome c. Moreover, bufalin inhibited MTX-resistant osteosarcoma xenograft growth, and a down-regulation of Hsp27 in vivo was observed. Taken together, bufalin exerted potent anti-osteosarcoma effects in vitro and in vivo, even in MTX resistant osteosarcoma cells. The down-regulation of Hsp27 played a critical role in bufalin-induced apoptosis in osteosarcoma cells. Bufalin may have merit to be a potential chemotherapeutic agent for osteosarcoma, particularly in MTX-resistant groups.

  4. Human-derived physiological heat shock protein 27 complex protects brain after focal cerebral ischemia in mice.

    Directory of Open Access Journals (Sweden)

    Shinichiro Teramoto

    Full Text Available Although challenging, neuroprotective therapies for ischemic stroke remain an interesting strategy for countering ischemic injury and suppressing brain tissue damage. Among potential neuroprotective molecules, heat shock protein 27 (HSP27 is a strong cell death suppressor. To assess the neuroprotective effects of HSP27 in a mouse model of transient middle cerebral artery occlusion, we purified a "physiological" HSP27 (hHSP27 from normal human lymphocytes. hHSP27 differed from recombinant HSP27 in that it formed dimeric, tetrameric, and multimeric complexes, was phosphorylated, and contained small amounts of αβ-crystallin and HSP20. Mice received intravenous injections of hHSP27 following focal cerebral ischemia. Infarct volume, neurological deficit scores, physiological parameters, and immunohistochemical analyses were evaluated 24 h after reperfusion. Intravenous injections of hHSP27 1 h after reperfusion significantly reduced infarct size and improved neurological deficits. Injected hHSP27 was localized in neurons on the ischemic side of the brain. hHSP27 suppressed neuronal cell death resulting from cytochrome c-mediated caspase activation, oxidative stress, and inflammatory responses. Recombinant HSP27 (rHSP27, which was artificially expressed and purified from Escherichia coli, and dephosphorylated hHSP27 did not have brain protective effects, suggesting that the phosphorylation of hHSP27 may be important for neuroprotection after ischemic insults. The present study suggests that hHSP27 with posttranslational modifications provided neuroprotection against ischemia/reperfusion injury and that the protection was mediated through the inhibition of apoptosis, oxidative stress, and inflammation. Intravenously injected human HSP27 should be explored for the treatment of acute ischemic strokes.

  5. Analysis of a self-propelling sheet with heat transfer through non-isothermal fluid in an inclined human cervical canal.

    Science.gov (United States)

    Walait, Ahsan; Siddiqui, A M; Rana, M A

    2018-02-13

    The present theoretical analysis deals with biomechanics of the self-propulsion of a swimming sheet with heat transfer through non-isothermal fluid filling an inclined human cervical canal. Partial differential equations arising from the mathematical modeling of the proposed model are solved analytically. Flow variables like pressure gradient, propulsive velocity, fluid velocity, time mean flow rate, fluid temperature, and heat-transfer coefficients are analyzed for the pertinent parameters. Striking features of the pumping characteristics are explored. Propulsive velocity of the swimming sheet becomes faster for lower Froude number, higher Reynolds number, and for a vertical channel. Temperature and peak value of the heat-transfer coefficients below the swimming sheet showed an increase by the increment of Brinkmann number, inclination, pressure difference over wavelength, and Reynolds number whereas these quantities decrease with increasing Froude number. Aforesaid parameters have shown opposite effects on the peak value of the heat-transfer coefficients below and above the swimming sheet. Relevance of the current results to the spermatozoa transport with heat transfer through non-isothermal cervical mucus filling an inclined human cervical canal is also explored.

  6. Methods of evaluating protective clothing relative to heat and cold stress: thermal manikin, biomedical modeling, and human testing.

    Science.gov (United States)

    O'Brien, Catherine; Blanchard, Laurie A; Cadarette, Bruce S; Endrusick, Thomas L; Xu, Xiaojiang; Berglund, Larry G; Sawka, Michael N; Hoyt, Reed W

    2011-10-01

    Personal protective equipment (PPE) refers to clothing and equipment designed to protect individuals from chemical, biological, radiological, nuclear, and explosive hazards. The materials used to provide this protection may exacerbate thermal strain by limiting heat and water vapor transfer. Any new PPE must therefore be evaluated to ensure that it poses no greater thermal strain than the current standard for the same level of hazard protection. This review describes how such evaluations are typically conducted. Comprehensive evaluation of PPE begins with a biophysical assessment of materials using a guarded hot plate to determine the thermal characteristics (thermal resistance and water vapor permeability). These characteristics are then evaluated on a thermal manikin wearing the PPE, since thermal properties may change once the materials have been constructed into a garment. These data may be used in biomedical models to predict thermal strain under a variety of environmental and work conditions. When the biophysical data indicate that the evaporative resistance (ratio of permeability to insulation) is significantly better than the current standard, the PPE is evaluated through human testing in controlled laboratory conditions appropriate for the conditions under which the PPE would be used if fielded. Data from each phase of PPE evaluation are used in predictive models to determine user guidelines, such as maximal work time, work/rest cycles, and fluid intake requirements. By considering thermal stress early in the development process, health hazards related to temperature extremes can be mitigated while maintaining or improving the effectiveness of the PPE for protection from external hazards.

  7. Human psychophysics and rodent spinal neurones exhibit peripheral and central mechanisms of inflammatory pain in the UVB and UVB heat rekindling models.

    Science.gov (United States)

    O'Neill, Jessica; Sikandar, Shafaq; McMahon, Stephen B; Dickenson, Anthony H

    2015-09-01

    Translational research is key to bridging the gaps between preclinical findings and the patients, and a translational model of inflammatory pain will ideally induce both peripheral and central sensitisation, more effectively mimicking clinical pathophysiology in some chronic inflammatory conditions. We conducted a parallel investigation of two models of inflammatory pain, using ultraviolet B (UVB) irradiation alone and UVB irradiation with heat rekindling. We used rodent electrophysiology and human quantitative sensory testing to characterise nociceptive processing in the peripheral and central nervous systems in both models. In both species, UVB irradiation produces peripheral sensitisation measured as augmented evoked activity of rat dorsal horn neurones and increased perceptual responses of human subjects to mechanical and thermal stimuli. In both species, UVB with heat rekindling produces central sensitisation. UVB irradiation alone and UVB with heat rekindling are translational models of inflammation that produce peripheral and central sensitisation, respectively. The predictive value of laboratory models for human pain processing is crucial for improving translational research. The discrepancy between peripheral and central mechanisms of pain is an important consideration for drug targets, and here we describe two models of inflammatory pain that involve ultraviolet B (UVB) irradiation, which can employ peripheral and central sensitisation to produce mechanical and thermal hyperalgesia in rats and humans. We use electrophysiology in rats to measure the mechanically- and thermally-evoked activity of rat spinal neurones and quantitative sensory testing to assess human psychophysical responses to mechanical and thermal stimulation in a model of UVB irradiation and in a model of UVB irradiation with heat rekindling. Our results demonstrate peripheral sensitisation in both species driven by UVB irradiation, with a clear mechanical and thermal hypersensitivity of

  8. Inhibition of inducible heat shock protein-70 (hsp72 enhances bortezomib-induced cell death in human bladder cancer cells.

    Directory of Open Access Journals (Sweden)

    Wei Qi

    Full Text Available The proteasome inhibitor bortezomib (Velcade is a promising new agent for bladder cancer therapy, but inducible cytoprotective mechanisms may limit its potential efficacy. We used whole genome mRNA expression profiling to study the effects of bortezomib on stress-induced gene expression in a panel of human bladder cancer cell lines. Bortezomib induced strong upregulation of the inducible HSP70 isoforms HSPA1A and HSPA1B isoforms of Hsp72 in 253J B-V and SW780 (HSPA1A(high cells, but only induced the HSPA1B isoform in UM-UC10 and UM-UC13 (HSPA1A(low cells. Bortezomib stimulated the binding of heat shock factor-1 (HSF1 to the HSPA1A promoter in 253JB-V but not in UM-UC13 cells. Methylation-specific PCR revealed that the HSPA1A promoter was methylated in the HSPA1A(low cell lines (UM-UC10 and UM-UC13, and exposure to the chromatin demethylating agent 5-aza-2'-deoxycytidine restored HSPA1A expression. Overexpression of Hsp72 promoted bortezomib resistance in the UM-UC10 and UM-UC13 cells, whereas transient knockdown of HSPA1B further sensitized these cells to bortezomib, and exposure to the chemical HSF1 inhibitor KNK-437 promoted bortezomib sensitivity in the 253J B-V cells. Finally, shRNA-mediated stable knockdown of Hsp72 in 253J B-V promoted sensitivity to bortezomib in vitro and in tumor xenografts in vivo. Together, our results provide proof-of-concept for using Hsp72 inhibitors to promote bortezomib sensitivity in bladder cancers and suggest that selective targeting of HSPA1B could produce synthetic lethality in tumors that display HSPA1A promoter methylation.

  9. Comparative Survival Rates of Human-Derived Probiotic Lactobacillus paracasei and L. salivarius Strains during Heat Treatment and Spray Drying

    Science.gov (United States)

    Gardiner, G. E.; O'Sullivan, E.; Kelly, J.; Auty, M. A. E.; Fitzgerald, G. F.; Collins, J. K.; Ross, R. P.; Stanton, C.

    2000-01-01

    Spray drying of skim milk was evaluated as a means of preserving Lactobacillus paracasei NFBC 338 and Lactobacillus salivarius UCC 118, which are human-derived strains with probiotic potential. Our initial experiments revealed that NFBC 338 is considerably more heat resistant in 20% (wt/vol) skim milk than UCC 118 is; the comparable decimal reduction times were 11.1 and 1.1 min, respectively, at 59°C. An air outlet temperature of 80 to 85°C was optimal for spray drying; these conditions resulted in powders with moisture contents of 4.1 to 4.2% and viable counts of 3.2 × 109 CFU/g for NFBC 338 and 5.2 × 107 CFU/g for UCC 118. Thus, L. paracasei NFBC 338 survived better than L. salivarius UCC 118 during spray drying; similar results were obtained when we used confocal scanning laser microscopy and LIVE/DEAD BacLight viability staining. In addition, confocal scanning laser microscopy revealed that the probiotic lactobacilli were located primarily in the powder particles. Although both spray-dried cultures appeared to be stressed, as shown by increased sensitivity to NaCl, bacteriocin production by UCC 118 was not affected by the process, nor was the activity of the bacteriocin peptide. The level of survival of NFBC 338 remained constant at ∼1 × 109 CFU/g during 2 months of powder storage at 4°C, while a decline in the level of survival of approximately 1 log (from 7.2 × 107 to 9.5 × 106 CFU/g) was observed for UCC 118 stored under the same conditions. However, survival of both Lactobacillus strains during powder storage was inversely related to the storage temperature. Our data demonstrate that spray drying may be a cost-effective way to produce large quantities of some probiotic cultures. PMID:10831444

  10. Cloning, characterization, and heat stress-induced redistribution of a protein homologous to human hsp27 in the zebrafish Danio rerio

    International Nuclear Information System (INIS)

    Mao Li; Bryantsev, Anton L.; Chechenova, Maria B.; Shelden, Eric A.

    2005-01-01

    Hsp27 is a small heat shock protein (shsp) regulating stress tolerance and increasingly thought to play roles in tissue homeostasis and differentiation. The zebrafish Danio rerio is an important model for the study of developmental processes, but little is known regarding shsps in this animal. Here, we report the sequence, expression, regulation, and function of a zebrafish protein (zfHsp27) homologous to human Hsp27. zfHsp27 contains three conserved phosphorylatable serines and a cysteine important for regulation of apoptosis, but it lacks much of a C-terminal tail domain and shows low homology in two putative actin interacting domains that are features of mammalian Hsp27. zfHsp27 mRNA is most abundant in adult skeletal muscle and heart and is upregulated during early embryogenesis. zfHsp27 expressed in mammalian fibroblasts was phosphorylated in response to heat stress and anisomycin, and this phosphorylation was prevented by treatment with SB202190, an inhibitor of p38 MAPK. Expression of zfHsp27 and human Hsp27 in mammalian fibroblasts promoted a similar degree of tolerance to heat stress. zfHsp27 fusion proteins entered the nucleus and associated with the cytoskeleton of heat stressed cells in vitro and in zebrafish embryos. These results reveal conservation in regulation and function of mammalian and teleost Hsp27 proteins and define zebrafish as a new model for the study of Hsp27 function

  11. Effect of the Evaporative Cooling on the Human Thermal Comfort and Heat Stress in a Greenhouse under Arid Conditions

    Directory of Open Access Journals (Sweden)

    A. M. Abdel-Ghany

    2013-01-01

    Full Text Available Thermal sensation and heat stress were evaluated in a plastic greenhouse, with and without evaporative cooling, under arid climatic conditions in Riyadh, Saudi Arabia. Suitable thermal comfort and heat stress scales were selected for the evaluation. Experiments were conducted in hot sunny days to measure the required parameters (i.e., the dry and wet bulb temperatures, globe temperature, natural wet bulb temperature, and solar radiation flux in the greenhouse. The results showed that in the uncooled greenhouse, workers are exposed to strong heat stress and would feel very hot most of the day time; they are safe from heat stress risk and would feel comfortable during night. An efficient evaporative cooling is necessary during the day to reduce heat stress and to improve the comfort conditions and is not necessary at night. In the cooled greenhouse, workers can do any activity: except at around noon they should follow a proposed working schedule, in which the different types of work were scheduled along the daytimes based on the heat stress value. To avoid heat stress and to provide comfort conditions in the greenhouses, the optimum ranges of relative humidity and air temperature are 48–55% and 24–28°C, respectively.

  12. Effects of Long-Term Exposure to 60 GHz Millimeter-Wavelength Radiation on the Genotoxicity and Heat Shock Protein (Hsp Expression of Cells Derived from Human Eye

    Directory of Open Access Journals (Sweden)

    Shin Koyama

    2016-08-01

    Full Text Available Human corneal epithelial (HCE-T and human lens epithelial (SRA01/04 cells derived from the human eye were exposed to 60 gigahertz (GHz millimeter-wavelength radiation for 24 h. There was no statistically significant increase in the micronucleus (MN frequency in cells exposed to 60 GHz millimeter-wavelength radiation at 1 mW/cm2 compared with sham-exposed controls and incubator controls. The MN frequency of cells treated with bleomycin for 1 h provided positive controls. The comet assay, used to detect DNA strand breaks, and heat shock protein (Hsp expression also showed no statistically significant effects of exposure. These results indicate that exposure to millimeter-wavelength radiation has no effect on genotoxicity in human eye cells.

  13. Performance and Costs of Ductless Heat Pumps in Marine-Climate High-Performance Homes -- Habitat for Humanity The Woods

    Energy Technology Data Exchange (ETDEWEB)

    Lubliner, Michael [Washington State Univ., Pullman, WA (United States); Howard, Luke [Washington State Univ., Pullman, WA (United States); Hales, David [Washington State Univ., Pullman, WA (United States); Kunkle, Rick [Washington State Univ., Pullman, WA (United States); Gordon, Andy [Washington State Univ., Pullman, WA (United States); Spencer, Melinda [Washington State Univ., Pullman, WA (United States)

    2016-02-23

    This final Building America Partnership report focuses on the results of field testing, modeling, and monitoring of ductless mini-split heat pump hybrid heating systems in seven homes built and first occupied at various times between September 2013 and October 2014. The report also provides WSU documentation of high-performance home observations, lessons learned, and stakeholder recommendations for builders of affordable high-performance housing.

  14. Heat pumps: heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pielke, R

    1976-01-01

    The author firstly explains in a general manner the functioning of the heat pump. Following a brief look at the future heat demand and the possibilities of covering it, the various methods of obtaining energy (making use of solar energy, ground heat, and others) and the practical applications (office heating, swimming pool heating etc.) are explained. The author still sees considerable difficulties in using the heat pump at present on a large scale. Firstly there is not enough maintenance personnel available, secondly the electricity supply undertakings cannot provide the necessary electricity on a wide basis without considerable investments. Other possibilities to save energy or to use waste energy are at present easier and more economical to realize. Recuperative and regenerative systems are described.

  15. Study of thermal threshold and counter-measures for human body in oceanic working environment. 1st Report. Heat balance model and heat storage index; Shonetsu kankyoka no kaiyo sagyo ni okeru netsuteki genkai to onnetsu taisaku ni kansuru kenkyu. 1. Netsu shushi model to onnetsu shisu

    Energy Technology Data Exchange (ETDEWEB)

    Fukuchi, N. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Nakamura, M. [Tokyo Gakugei University, Tokyo (Japan); Murayama, M.

    1996-12-31

    Identification was intended on effects of such thermal factors as metabolic amount, environmental temperature and humidity, and clothing resistance on human body temperatures during works under hot environments. Therefore, measurements were carried out on human skin temperatures, rectum temperatures and humidity inside clothing, while amount of motion, environmental temperature, and clothing are changed in a constant temperature room and under a sun irradiation environment. Furthermore, a heat balance model was prepared, which divides the objects into an outer shell layer whose temperature changes depending on the result of this experiment and into a core having constant temperature characteristics. An equation to derive skin temperatures was introduced from the model. The equation formulated a calculation formula for heat accumulation in human body, which can be used as a hot heat index. Relationship between thermal factors and heat storage amount was investigated to consider a thermal limit for a physical work. An equation to derive skin temperatures was confirmed capable of expressing general change in skin temperatures, being proved by comparison with experiments. Calculation formulas for amount of heat stored in human body were shown capable of expressing influence of different thermal factors, the expression being useful as a hot heat index. Calculating the human body heat storage is very largely affected by effect of sweat to dissipate heat, hence it is necessary to improve the accuracy including that for body temperature adjusting reactions. 17 refs., 17 figs., 5 tabs.

  16. Study of thermal threshold and counter-measures for human body in oceanic working environment. 1st Report. Heat balance model and heat storage index; Shonetsu kankyoka no kaiyo sagyo ni okeru netsuteki genkai to onnetsu taisaku ni kansuru kenkyu. 1. Netsu shushi model to onnetsu shisu

    Energy Technology Data Exchange (ETDEWEB)

    Fukuchi, N [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Nakamura, M [Tokyo Gakugei University, Tokyo (Japan); Murayama, M

    1997-12-31

    Identification was intended on effects of such thermal factors as metabolic amount, environmental temperature and humidity, and clothing resistance on human body temperatures during works under hot environments. Therefore, measurements were carried out on human skin temperatures, rectum temperatures and humidity inside clothing, while amount of motion, environmental temperature, and clothing are changed in a constant temperature room and under a sun irradiation environment. Furthermore, a heat balance model was prepared, which divides the objects into an outer shell layer whose temperature changes depending on the result of this experiment and into a core having constant temperature characteristics. An equation to derive skin temperatures was introduced from the model. The equation formulated a calculation formula for heat accumulation in human body, which can be used as a hot heat index. Relationship between thermal factors and heat storage amount was investigated to consider a thermal limit for a physical work. An equation to derive skin temperatures was confirmed capable of expressing general change in skin temperatures, being proved by comparison with experiments. Calculation formulas for amount of heat stored in human body were shown capable of expressing influence of different thermal factors, the expression being useful as a hot heat index. Calculating the human body heat storage is very largely affected by effect of sweat to dissipate heat, hence it is necessary to improve the accuracy including that for body temperature adjusting reactions. 17 refs., 17 figs., 5 tabs.

  17. Field tests on human tolerance to (LNG) fire radiant heat exposure, and attenuation effects of clothing and other objects

    International Nuclear Information System (INIS)

    Raj, Phani K.

    2008-01-01

    A series of field tests exposing mannequins clothed with civilian clothing to a 3 m x 3 m square liquefied natural gas (LNG) pool fire was conducted. Both single layer clothing and double layer clothing were used. The radiant heat flux incident outside the clothing and incident on the skin covered by clothing were measured using wide-angle radiometers, for durations of 100-200 s (per test). The levels of heat flux incident on the clothing were close to 5 kW/m 2 . The magnitude of the radiant heat attenuation factor (AF) across the thickness was determined. AF varies between 2 and higher for cotton and polyester clothing (thickness 0.286-1.347 mm); AF value of 6 was measured for 1.347 mm thickness. Single sheet newspaper held about 5 cm in front of mannequins and exposed to incident flux of 5 kW/m 2 resulted in AF of 5, and AF of 8 with double sheets. AF decreases linearly with increasing heat flux values and linearly increases with thickness. The author exposed himself, in normal civilian clothing (of full sleeve cotton/polyester shirt and jean pants), to radiant heat from a LNG fire. The exposure was for several tens of seconds to heat flux levels ranging from 3.5 kW/m 2 to 5 + kW/m 2 (exposure times from 25 s to 97 s at average heat flux values in the 4 kW/m 2 and 5 kW/m 2 range). Occasionally, he was exposed to (as high as) 7 kW/m 2 for durations of several seconds. He did not suffer any unbearable or even severe pain nor did he experience blisters or burns or any other injury on the unprotected skin of his body. The incident heat fluxes on the author were measured by a hand-held radiometer (with digital display) as well as by strapped on wide-angle radiometers connected to a computer. He could withstand the US regulatory criterion of 5 kW/m 2 (for 30 s) without suffering any damage or burns. Temperature measured on author's skin covered by clothing did not rise above the normal body temperature even after 200 s of exposure to 4 kW/m 2 average heat flux

  18. Neural and non-neural control of skin blood flow during isometric handgrip exercise in the heat stressed human

    DEFF Research Database (Denmark)

    Shibasaki, M.; Rasmussen, P.; Secher, Niels H.

    2009-01-01

    as an absence of sweating and cutaneous vasodilatation during a whole-body heat stress. Upon this confirmation, adenosine was perfused through one of the microdialysis probes to increase skin blood flow similar to that of the unblocked site. After internal temperature increased approximately 0.7 degrees C......During heat stress, isometric handgrip (IHG) exercise causes cutaneous vasoconstriction, but it remains controversial whether neural mechanisms are responsible for this observation. The objective of this study was to test the hypothesis that cutaneous vasoconstriction during IHG exercise in heat...... stressed individuals occurs via a neural mechanism. An axillary nerve blockade was performed to block efferent nerve traffic to the left forearm in seven healthy subjects. Two intradermal microdialysis probes were placed within forearm skin of the blocked area. Forearm skin blood flow was measured by laser...

  19. Reduced heat shock response in human mononuclear cells during aging and its association with polymorphisms in HSP70 genes

    DEFF Research Database (Denmark)

    Singh, Ripudaman; Kølvraa, Steen; Bross, Peter

    2006-01-01

    Age-dependent changes in heat shock response (HSR) were studied in mononuclear cells (monocytes and lymphocytes) collected from young (mean age = 22.6 +/- 1.7 years) and middle-aged (mean age = 56.3 +/- 4.7 years) subjects after 1 hour of heat shock at 42 degrees C. Genotype-specific HSR...... was measured by genotyping the subjects for 3 single nucleotide polymorphisms, HSPA1A(A-110C), HSPA1B(A1267G), and HSPA1L(T2437C), 1 each in the 3 HSP70 genes. A significant age-related decrease in the induction of Hsp70 occurred after heat shock in both monocytes and lymphocytes. The noninducible...

  20. Heat pipe heat storage performance

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, A; Pasquetti, R [Univ. de Provence, Marseille (FR). Inst. Universitaire des Systemes; Grakovich, L P; Vasiliev, L L [A.V. Luikov Heat and Mass Transfer Inst. of the BSSR, Academy of Sciences, Minsk (BY)

    1989-01-01

    Heat storage offers essential thermal energy saving for heating. A ground heat store equipped with heat pipes connecting it with a heat source and to the user is considered in this paper. It has been shown that such a heat exchanging system along with a batch energy source meets, to a considerable extent, house heating requirements. (author).

  1. Heat transfer

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Heat transfer. Heat conduction in solid slab. Convective heat transfer. Non-linear temperature. variation due to flow. HEAT FLUX AT SURFACE. conduction/diffusion.

  2. Heat Waves

    Science.gov (United States)

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and spasms due ... that the body is having trouble with the heat. If a heat wave is predicted or happening… - ...

  3. Heat Islands

    Science.gov (United States)

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  4. Heat Increases the Editing Efficiency of Human Papillomavirus E2 Gene by Inducing Upregulation of APOBEC3A and 3G.

    Science.gov (United States)

    Yang, Yang; Wang, Hexiao; Zhang, Xinrui; Huo, Wei; Qi, Ruiqun; Gao, Yali; Zhang, Gaofeng; Song, Bing; Chen, Hongduo; Gao, Xinghua

    2017-04-01

    Apolipoprotein B mRNA-editing catalytic polypeptide (APOBEC) 3 proteins have been identified as potent viral DNA mutators and have broad antiviral activity. In this study, we demonstrated that apolipoprotein B mRNA-editing catalytic polypeptide 3A (A3A) and A3G expression levels were significantly upregulated in human papillomavirus (HPV)-infected cell lines and tissues. Heat treatment resulted in elevated expression of A3A and A3G in a temperature-dependent manner in HPV-infected cells. Correspondingly, HPV-infected cells heat-treated at 44 °C showed accumulated G-to-A or C-to-T mutation in HPV E2 gene. Knockdown of A3A or A3G could promote cell viability, along with the lower frequency of A/T in HPV E2 gene. In addition, regressing genital viral warts also harbored high G-to-A or C-to-T mutation in HPV E2 gene. Taken together, we demonstrate that apolipoprotein B mRNA-editing catalytic polypeptide 3 expression and editing function was heat sensitive to a certain degree, partly explaining the mechanism of action of local hyperthermia to treat viral warts. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Hexavalent chromium, a lung carcinogen, confers resistance to thermal stress and interferes with heat shock protein expression in human bronchial epithelial cells.

    Science.gov (United States)

    Abreu, Patrícia L; Cunha-Oliveira, Teresa; Ferreira, Leonardo M R; Urbano, Ana M

    2018-03-16

    Exposure to hexavalent chromium [Cr(VI)], a lung carcinogen, triggers several types of cellular stresses, namely oxidative, genotoxic and proteotoxic stresses. Given the evolutionary character of carcinogenesis, it is tempting to speculate that cells that survive the stresses produced by this carcinogen become more resistant to subsequent stresses, namely those encountered during neoplastic transformation. To test this hypothesis, we determined whether pre-incubation with Cr(VI) increased the resistance of human bronchial epithelial cells (BEAS-2B cells) to the antiproliferative action of acute thermal shock, used here as a model for stress. In line with the proposed hypothesis, it was observed that, at mildly cytotoxic concentrations, Cr(VI) attenuated the antiproliferative effects of both cold and heat shock. Mechanistically, Cr(VI) interfered with the expression of two components of the stress response pathway: heat shock proteins Hsp72 and Hsp90α. Specifically, Cr(VI) significantly depleted the mRNA levels of the former and the protein levels of the latter. Significantly, these two proteins are members of heat shock protein (Hsp) families (Hsp70 and Hsp90, respectively) that have been implicated in carcinogenesis. Thus, our results confirm and extend previous studies showing the capacity of Cr(VI) to interfere with the expression of stress response components.

  6. Effects of human performance methods of the radiation exposure of the task personnel during the inspection of steam generator heat tubes

    International Nuclear Information System (INIS)

    Wilkes, Bernd; Bienentreu, Robert

    2008-01-01

    Westinghouse has implemented the so called human performance philosophy for specific scopes of work. Human performance is supposed to establish and support personnel behavior aimed to a safe and reliable operation of the plant. The overall goal is the prevention of errors. Every action deviating from the expected behavior is defined as an error, independent of the consequences. The accident statistics has shown that every severe accident was preceded by hundreds of events without consequences. The implementation of these techniques is demonstrated using the process of steam generator heat tube inspection. According to the ALARA principle a lot of effort was concentrated on dose reduction for the personnel, including constructive (improved testing probes, improved manipulator, etc.) and administrative measures.

  7. Heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, E L; Eisenmann, G; Hahne, E [Stuttgart Univ. (TH) (F.R. Germany). Inst. fuer Thermodynamik und Waermetechnik

    1976-04-01

    A survey is presented on publications on design, heat transfer, form factors, free convection, evaporation processes, cooling towers, condensation, annular gap, cross-flowed cylinders, axial flow through a bundle of tubes, roughnesses, convective heat transfer, loss of pressure, radiative heat transfer, finned surfaces, spiral heat exchangers, curved pipes, regeneraters, heat pipes, heat carriers, scaling, heat recovery systems, materials selection, strength calculation, control, instabilities, automation of circuits, operational problems and optimization.

  8. Identification of Molecular Fingerprints in Human Heat Pain Thresholds by Use of an Interactive Mixture Model R Toolbox (AdaptGauss).

    Science.gov (United States)

    Ultsch, Alfred; Thrun, Michael C; Hansen-Goos, Onno; Lötsch, Jörn

    2015-10-28

    Biomedical data obtained during cell experiments, laboratory animal research, or human studies often display a complex distribution. Statistical identification of subgroups in research data poses an analytical challenge. Here were introduce an interactive R-based bioinformatics tool, called "AdaptGauss". It enables a valid identification of a biologically-meaningful multimodal structure in the data by fitting a Gaussian mixture model (GMM) to the data. The interface allows a supervised selection of the number of subgroups. This enables the expectation maximization (EM) algorithm to adapt more complex GMM than usually observed with a noninteractive approach. Interactively fitting a GMM to heat pain threshold data acquired from human volunteers revealed a distribution pattern with four Gaussian modes located at temperatures of 32.3, 37.2, 41.4, and 45.4 °C. Noninteractive fitting was unable to identify a meaningful data structure. Obtained results are compatible with known activity temperatures of different TRP ion channels suggesting the mechanistic contribution of different heat sensors to the perception of thermal pain. Thus, sophisticated analysis of the modal structure of biomedical data provides a basis for the mechanistic interpretation of the observations. As it may reflect the involvement of different TRP thermosensory ion channels, the analysis provides a starting point for hypothesis-driven laboratory experiments.

  9. Heat Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH HEAT STRESS Recommend on Facebook Tweet Share Compartir OSHA-NIOSH ... hot environments may be at risk of heat stress. Exposure to extreme heat can result in occupational ...

  10. Modeling and Docking Studies on Novel Mutants (K71L and T204V of the ATPase Domain of Human Heat Shock 70 kDa Protein 1

    Directory of Open Access Journals (Sweden)

    Asita Elengoe

    2014-04-01

    Full Text Available The purpose of exploring protein interactions between human adenovirus and heat shock protein 70 is to exploit a potentially synergistic interaction to enhance anti-tumoral efficacy and decrease toxicity in cancer treatment. However, the protein interaction of Hsp70 with E1A32 kDa of human adenovirus serotype 5 remains to be elucidated. In this study, two residues of ATPase domain of human heat shock 70 kDa protein 1 (PDB: 1 HJO were mutated. 3D mutant models (K71L and T204V using PyMol software were then constructed. The structures were evaluated by PROCHECK, ProQ, ERRAT, Verify 3D and ProSA modules. All evidence suggests that all protein models are acceptable and of good quality. The E1A32 kDa motif was retrieved from UniProt (P03255, as well as subjected to docking interaction with NBD, K71L and T204V, using the Autodock 4.2 program. The best lowest binding energy value of −9.09 kcal/mol was selected for novel T204V. Moreover, the protein-ligand complex structures were validated by RMSD, RMSF, hydrogen bonds and salt bridge analysis. This revealed that the T204V-E1A32 kDa motif complex was the most stable among all three complex structures. This study provides information about the interaction between Hsp70 and the E1A32 kDa motif, which emphasizes future perspectives to design rational drugs and vaccines in cancer therapy.

  11. Whole-body pre-cooling does not alter human muscle metabolism during sub-maximal exercise in the heat.

    Science.gov (United States)

    Booth, J; Wilsmore, B R; Macdonald, A D; Zeyl, A; Mcghee, S; Calvert, D; Marino, F E; Storlien, L H; Taylor, N A

    2001-06-01

    Muscle metabolism was investigated in seven men during two 35 min cycling trials at 60% peak oxygen uptake, at 35 degrees C and 50% relative humidity. On one occasion, exercise was preceded by whole-body cooling achieved by immersion in water during a reduction in temperature from 29 to 24 degrees C, and, for the other trial, by immersion in water at a thermoneutral temperature (control, 34.8 degrees C). Pre-cooling did not alter oxygen uptake during exercise (P > 0.05), whilst the change in cardiac frequency and body mass both tended to be lower following pre-cooling (0.05 whole-body pre-cooling does not alter muscle metabolism during submaximal exercise in the heat. It is more likely that thermoregulatory and cardiovascular strain are reduced, through lower muscle and core temperatures.

  12. Evaluation of deoxyribonucleic acid (DNA) isolated from human bloodstains exposed to ultraviolet light, heat, humidity, and soil contamination

    International Nuclear Information System (INIS)

    McNally, L.; Shaler, R.C.; Baird, M.; Balazs, I.; De Forest, P.; Kobilinsky, L.

    1989-01-01

    This study was designed to analyze the effects of common environmental insults on the ability to obtain deoxyribonucleic acid (DNA) restriction fragment-length polymorphisms (RFLP) patterns from laboratory prepared specimens. The environmental conditions studied include the exposure of dried bloodstains to varying amounts of relative humidity (0, 33, 67, and 98%), heat (37 degree C), and ultraviolet light for periods of up to five days. In addition, the effect of drying over a four-day period in whole blood collected with and without ethylenediaminetetraacetate (EDTA) was examined. The results of the study showed that, under the conditions studied, the integrity of DNA is not altered such that false RFLP patterns are obtained. The only effect observed was that the overall RFLP pattern becomes weaker, but individual RFLP fragments are neither created nor destroyed

  13. Observing the Human Exposome as Reflected in Breath Biomarkers: Heat Map Data Interpretation for Environmental and Intelligence Research

    Science.gov (United States)

    Over the past decade, the research of human systems biology and the interactions with the external environment has permeated all phases of environmental, medical, and public health research. Similarly to the fields of genomics and proteomics research, the advent of new instrumen...

  14. Use of a finite element model of heat transport in the human eye to predict time of death.

    Science.gov (United States)

    Smart, Jimmy L; Kaliszan, Michal

    2013-01-01

    The goal of this work was to compare human temperature decay curves generated from execution of a COMSOL Multiphysics(®) finite element software model with that of experimental postmortem temperature decay curves. Experiments were performed in 10 human cadavers. The postmortem temperature was continuously measured in human eyeballs and rectums from c. 3 h up to 15 h postmortem. Model-generated curves reflected experimental curves for 10 cases with coefficients of determination ranging from 0.9448 to 0.9953. From modeling efforts, normalized temperature decay curves were generated to aid first responders to estimate time of death within the early postmortem period of 0-24 h. This proposed model has advantages over other models in that it is applied to the human eyeball, where temperature plateau effects are minimal to nonexistent. Nevertheless, the proposed model can be adjusted to compensate for any temperature plateau effects that do exist. It also can take account of antemortem hyperthermia conditions that are known to have occurred. The current model only applies to natural environmental conditions, with no forced convection, no direct sunlight, immersion in water, or other unusual conditions. © 2012 American Academy of Forensic Sciences.

  15. Divergence of canonical danger signals: The genome-level expression patterns of human mononuclear cells subjected to heat shock or lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Sakthivel Bhuvaneswari

    2008-05-01

    Full Text Available Abstract Background Peripheral blood mononuclear cells (PBMC serve a sentinel role allowing the host to efficiently sense and adapt to the presence of danger signals. Herein we have directly compared the genome-level expression patterns (microarray of a human PBMC model (THP-1 cells subjected to one of two canonical danger signals, heat shock or lipopolysaccharide (LPS. Results and Discussion Based on sequential expression and statistical filters, and in comparison to control cells, we found that 3,988 genes were differentially regulated in THP-1 cells subjected to LPS stress, and 2,921 genes were differentially regulated in THP-1 cells subjected to heat shock stress. Venn analyses demonstrated that the majority of differentially regulated genes (≥ 70% were uniquely expressed in response to one of the two danger signals. Functional analyses demonstrated that the two danger signals induced expression or repression of genes corresponding to unique pathways, molecular functions, biological processes, and gene networks. In contrast, there were 184 genes that were commonly upregulated by both stress signals, and 430 genes that were commonly downregulated by both stress signals. Interestingly, the 184 commonly upregulated genes corresponded to a gene network broadly related to inflammation, and more specifically to chemokine signaling. Conclusion These data demonstrate that the mononuclear cell responses to the canonical stress signals, heat shock and LPS, are highly divergent. However, there is a heretofore unrecognized common pattern of gene network expression corresponding to chemokine-related biology. The data also serve as a reference database for investigators in the field of stress signaling.

  16. Ekspresi Human Leukocyte Antigen-G (HLA-G dan Heat-Shock Protein-70 (Hsp-70 pada Pertumbuhan Janin Terhambat

    Directory of Open Access Journals (Sweden)

    Sri Sulistyowati

    2014-03-01

    Full Text Available Intra uterine growth retardation (IUGR is one of the leading causes of higher morbidity and mortality in perinatal. Immune maladaptation affects trophoblast invasion and spiralis arteria remodeling that will cause placental tissue hypoxia. This research aimed to analyze human leukocyte antigen-G (HLA-G and heat-shock protein-70 (Hsp-70 expression on the IUGR trophoblast and normal pregnancy, by applying analytical observational method and cross sectional approach. This research was conducted at the Obstetric and Gynecology Department of Dr. Moewardi Hospital Surakarta from November to December 2011. The total samples were 30, divided into two groups. There were 15 samples trophoblast on IUGR and 15 samples trophoblast from normal pregnancy. All samples were tested for HLA-G and Hsp-70 using immunohistochemistry. The data were analyzed by using t-test. The mean of HLA-G expression on the IUGR groups was 32.42±8.90 and on the normal pregnancy groups was 43.92±14.91 (p=0.016. Heat-shock protein70 expression on the IUGR groups was 2.4355+0.26647 and on the normal pregnancy groups was 1.5920+0.17142 with p=0.008. In conclusion, in IUGR, the HLA-G expression is lower and the Hsp-70 expression is higher than in normal pregnancy.

  17. Oligonol supplementation attenuates body temperature and the circulating levels of prostaglandin E2 and cyclooxygenase-2 after heat stress in humans.

    Science.gov (United States)

    Shin, Young Oh; Lee, Jeong Beom; Song, Young Ju; Min, Young Ki; Yang, Hun Mo

    2013-04-01

    Oligonol, a phenolic production from lychee, has been reported to exhibit anti-oxidative and anti-inflammatory effects. This study investigated the effect of Oligonol supplementation on circulating levels of prostaglandin E2 (PGE2) and cyclooxygenase (COX)-2, as well as body temperature, after heat stress in 17 healthy human male volunteers (age, 21.6±2.1 years). All experiments were performed in an automated climate chamber (26.0°C±0.5°C, relative humidity 60%±3.0%, air velocity less than 1 m/sec) between 2 and 5 p.m. Subjects ingested an Oligonol (100 mg)-containing beverage or placebo beverage before half-body immersion into hot water (42°C±0.5°C for 30 min). Tympanic and skin temperatures were measured and mean body temperatures were calculated. Serum concentrations of PGE2 and COX-2 were analyzed before, immediately after, and 60 min after immersion. Oligonol intake significantly prevented elevation of tympanic (temperature difference: 0.17°C at Post, Pbody temperatures (temperature difference: 0.18°C at Post, Pbody temperature under heat stress, and this is associated with decreases in serum levels of PGE2 and COX-2.

  18. Heat shock protein-27 protects human bronchial epithelial cells against oxidative stress–mediated apoptosis: possible implication in asthma

    Science.gov (United States)

    Merendino, Anna M.; Paul, Catherine; Vignola, Antonio M.; Costa, Maria A.; Melis, Mario; Chiappara, Giuseppina; Izzo, V.; Bousquet, J.; Arrigo, André-Patrick

    2002-01-01

    Inflammation of the human bronchial epithelium, as observed in asthmatics, is characterized by the selective death of the columnar epithelial cells, which desquamate from the basal cells. Tissue repair initiates from basal cells that resist inflammation. Here, we have evaluated the extent of apoptosis as well as the Hsp27 level of expression in epithelial cells from bronchial biopsy samples taken from normal and asthmatic subjects. Hsp27 is a chaperone whose expression protects against oxidative stress. We report that in asthmatic subjects the basal epithelium cells express a high level of Hsp27 but no apoptotic morphology. In contrast, apoptotic columnar cells are devoid of Hsp27 expression. Moreover, we observed a decreased resistance to hydrogen peroxide–induced apoptosis in human bronchial epithelial 16–HBE cells when they were genetically modified to express reduced levels of Hsp27. PMID:12482203

  19. Heat pumps

    CERN Document Server

    Macmichael, DBA

    1988-01-01

    A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

  20. The role of air pollution in the relationship between a heat stress index and human mortality in Toronto

    International Nuclear Information System (INIS)

    Rainham, D.G.C.; Smoyer-Tomic, Karen E.

    2003-01-01

    In this study we considered confounding from air pollutants and chronological variables in the relation between humidex, a summer temperature and humidity index, and nonaccidental mortality, from 1980-1996 in Toronto, Canada. Changes in the risk of death by age group, gender, and combined cardiac-respiratory cause of death were estimated for both 1 deg. C and 50-95th percentile increases in humidex using a generalized additive linear model. With air pollution terms in the models, relative risk (RR) point estimates narrowly exceeded 1.0 for all groups. Humidex effects were most apparent for females (RR=1.006, 95% CI=1.004-1.008 per 1 deg. C humidex and RR=1.089, 95% CI=1.058-1.121 for 50th to 95th percentile humidex). When air pollution was omitted from the model, RR in the 50-95th percentile analysis increased less than 1.71% for all groups except females, for which RR decreased 1.42%. Differences in RR per 1 deg. C humidex were all less than 0.12%. Confidence intervals narrowed slightly for all groups investigated. Heat stress has a statistically significant, yet minimal impact on Toronto populations, and air pollution does appear to have a small, but consistent confounding effect on humidex effect estimates

  1. Hepatitis C Virus E2 Protein Induces Upregulation of IL-8 Pathways and Production of Heat Shock Proteins in Human Thyroid Cells.

    Science.gov (United States)

    Hammerstad, Sara Salehi; Stefan, Mihaela; Blackard, Jason; Owen, Randall P; Lee, Hanna J; Concepcion, Erlinda; Yi, Zhengzi; Zhang, Weijia; Tomer, Yaron

    2017-02-01

    Thyroiditis is one of the most common extrahepatic manifestations of hepatitis C virus (HCV) infection. By binding to surface cell receptor CD81, HCV envelope glycoprotein E2 mediates entry of HCV into cells. Studies have shown that different viral proteins may individually induce host responses to infection. We hypothesized that HCV E2 protein binding to CD81 expressed on thyroid cells activates a cascade of inflammatory responses that can trigger autoimmune thyroiditis in susceptible individuals. Human thyroid cell lines ML-1 and human thyrocytes in primary cell culture were treated with HCV recombinant E2 protein. The expression of major proinflammatory cytokines was measured at the messenger RNA and protein levels. Next-generation transcriptome analysis was used to identify early changes in gene expression in thyroid cells induced by E2. HCV envelope protein E2 induced strong inflammatory responses in human thyrocytes, resulting in production of interleukin (IL)-8, IL-6, and tumor necrosis factor-α. Furthermore, the E2 protein induced production of several heat shock proteins including HSP60, HSP70p12A, and HSP10, in human primary thyrocytes. In thyroid cell line ML-1, RNA sequencing identified upregulation of molecules involved in innate immune pathways with high levels of proinflammatory cytokines and chemokines and increased expression of costimulatory molecules, specifically CD40, known to be a major thyroid autoimmunity gene. Our data support a key role for HCV envelope protein E2 in triggering thyroid autoimmunity through activation of cytokine pathways by bystander mechanisms. Copyright © 2017 by the Endocrine Society

  2. Human hnRNP Q re-localizes to cytoplasmic granules upon PMA, thapsigargin, arsenite and heat-shock treatments

    International Nuclear Information System (INIS)

    Quaresma, Alexandre J.C.; Bressan, G.C.; Gava, L.M.; Lanza, D.C.F.; Ramos, C.H.I; Kobarg, Joerg

    2009-01-01

    Eukaryotic gene expression is regulated on different levels ranging from pre-mRNA processing to translation. One of the most characterized families of RNA-binding proteins is the group of hnRNPs: heterogenous nuclear ribonucleoproteins. Members of this protein family play important roles in gene expression control and mRNAs metabolism. In the cytoplasm, several hnRNPs proteins are involved in RNA-related processes and they can be frequently found in two specialized structures, known as GW-bodies (GWbs), previously known as processing bodies: PBs, and stress granules, which may be formed in response to specific stimuli. GWbs have been early reported to be involved in the mRNA decay process, acting as a site of mRNA degradation. In a similar way, stress granules (SGs) have been described as cytoplasmic aggregates, which contain accumulated mRNAs in cells under stress conditions and present reduced or inhibited translation. Here, we characterized the hnRNP Q localization after different stress conditions. hnRNP Q is a predominantly nuclear protein that exhibits a modular organization and several RNA-related functions. Our data suggest that the nuclear localization of hnRNP Q might be modified after different treatments, such as: PMA, thapsigargin, arsenite and heat shock. Under different stress conditions, hnRNP Q can fully co-localize with the endoplasmatic reticulum specific chaperone, BiP. However, under stress, this protein only co-localizes partially with the proteins: GW182 - GWbs marker protein and TIA-1 stress granule component

  3. Science, practice, and human errors in controlling Clostridium botulinum in heat-preserved food in hermetic containers.

    Science.gov (United States)

    Pflug, Irving J

    2010-05-01

    The incidence of botulism in canned food in the last century is reviewed along with the background science; a few conclusions are reached based on analysis of published data. There are two primary aspects to botulism control: the design of an adequate process and the delivery of the adequate process to containers of food. The probability that the designed process will not be adequate to control Clostridium botulinum is very small, probably less than 1.0 x 10(-6), based on containers of food, whereas the failure of the operator of the processing equipment to deliver the specified process to containers of food may be of the order of 1 in 40, to 1 in 100, based on processing units (retort loads). In the commercial food canning industry, failure to deliver the process will probably be of the order of 1.0 x 10(-4) to 1.0 x 10(-6) when U.S. Food and Drug Administration (FDA) regulations are followed. Botulism incidents have occurred in food canning plants that have not followed the FDA regulations. It is possible but very rare to have botulism result from postprocessing contamination. It may thus be concluded that botulism incidents in canned food are primarily the result of human failure in the delivery of the designed or specified process to containers of food that, in turn, result in the survival, outgrowth, and toxin production of C. botulinum spores. Therefore, efforts in C. botulinum control should be concentrated on reducing human errors in the delivery of the specified process to containers of food.

  4. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

    2013-01-01

    Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

  5. Heat transfer

    International Nuclear Information System (INIS)

    Saad, M.A.

    1985-01-01

    Heat transfer takes place between material systems as a result of a temperature difference. The transmission process involves energy conversions governed by the first and second laws of thermodynamics. The heat transfer proceeds from a high-temperature region to a low-temperature region, and because of the finite thermal potential, there is an increase in entropy. Thermodynamics, however, is concerned with equilibrium states, which includes thermal equilibrium, irrespective of the time necessary to attain these equilibrium states. But heat transfer is a result of thermal nonequilibrium conditions, therefore, the laws of thermodynamics alone cannot describe completely the heat transfer process. In practice, most engineering problems are concerned with the rate of heat transfer rather than the quantity of heat being transferred. Resort then is directed to the particular laws governing the transfer of heat. There are three distinct modes of heat transfer: conduction, convection, and radiation. Although these modes are discussed separately, all three types may occur simultaneously

  6. Heat shock alters the expression of schizophrenia and autism candidate genes in an induced pluripotent stem cell model of the human telencephalon.

    Directory of Open Access Journals (Sweden)

    Mingyan Lin

    Full Text Available Schizophrenia (SZ and autism spectrum disorders (ASD are highly heritable neuropsychiatric disorders, although environmental factors, such as maternal immune activation (MIA, play a role as well. Cytokines mediate the effects of MIA on neurogenesis and behavior in animal models. However, MIA stimulators can also induce a febrile reaction, which could have independent effects on neurogenesis through heat shock (HS-regulated cellular stress pathways. However, this has not been well-studied. To help understand the role of fever in MIA, we used a recently described model of human brain development in which induced pluripotent stem cells (iPSCs differentiate into 3-dimensional neuronal aggregates that resemble a first trimester telencephalon. RNA-seq was carried out on aggregates that were heat shocked at 39°C for 24 hours, along with their control partners maintained at 37°C. 186 genes showed significant differences in expression following HS (p<0.05, including known HS-inducible genes, as expected, as well as those coding for NGFR and a number of SZ and ASD candidates, including SMARCA2, DPP10, ARNT2, AHI1 and ZNF804A. The degree to which the expression of these genes decrease or increase during HS is similar to that found in copy loss and copy gain copy number variants (CNVs, although the effects of HS are likely to be transient. The dramatic effect on the expression of some SZ and ASD genes places HS, and perhaps other cellular stressors, into a common conceptual framework with disease-causing genetic variants. The findings also suggest that some candidate genes that are assumed to have a relatively limited impact on SZ and ASD pathogenesis based on a small number of positive genetic findings, such as SMARCA2 and ARNT2, may in fact have a much more substantial role in these disorders - as targets of common environmental stressors.

  7. Heat and exercise acclimation increases intracellular levels of Hsp72 and inhibits exercise-induced increase in intracellular and plasma Hsp72 in humans.

    Science.gov (United States)

    Magalhães, Flávio de Castro; Amorim, Fabiano Trigueiro; Passos, Renata L Freitas; Fonseca, Michele Atalla; Oliveira, Kenya Paula Moreira; Lima, Milene Rodrigues Malheiros; Guimarães, Juliana Bohen; Ferreira-Júnior, João Batista; Martini, Angelo R P; Lima, Nilo R V; Soares, Danusa Dias; Oliveira, Edilamar Menezes; Rodrigues, Luiz Oswaldo Carneiro

    2010-11-01

    In order to verify the effects of heat and exercise acclimation (HA) on resting and exercise-induced expression of plasma and leukocyte heat shock protein 72 (Hsp72) in humans, nine healthy young male volunteers (25.0 ± 0.7 years; 80.5 ± 2.0 kg; 180 ± 2 cm, mean ± SE) exercised for 60 min in a hot, dry environment (40 ± 0°C and 45 ± 0% relative humidity) for 11 days. The protocol consisted of running on a treadmill using a controlled hyperthermia technique in which the work rate was adjusted to elevate the rectal temperature by 1°C in 30 min and maintain it elevated for another 30 min. Before and after the HA, the volunteers performed a heat stress test (HST) at 50% of their individual maximal power output for 90 min in the same environment. Blood was drawn before (REST), immediately after (POST) and 1 h after (1 h POST) HST, and plasma and leukocytes were separated and stored. Subjects showed expected adaptations to HA: reduced exercise rectal and mean skin temperatures and heart rate, and augmented sweat rate and exercise tolerance. In HST1, plasma Hsp72 increased from REST to POST and then returned to resting values 1 h POST (REST: 1.11 ± 0.07, POST: 1.48 ± 0.10, 1 h POST: 1.22 ± 0.11 ng mL(-1); p  0.05). HA increased resting levels of intracellular Hsp72 (HST1: 1 ± 0.02 and HST2: 4.2 ± 1.2 density units, p  0.05). Regression analysis showed that the lower the pre-exercise expression of intracellular Hsp72, the higher the exercise-induced increase (R = -0.85, p < 0.05). In conclusion, HA increased resting leukocyte Hsp72 levels and inhibited exercise-induced expression. This intracellular adaptation probably induces thermotolerance. In addition, the non-increase in plasma Hsp72 after HA may be related to lower stress at the cellular level in the acclimated individuals.

  8. Heat exchanger

    Science.gov (United States)

    Daman, Ernest L.; McCallister, Robert A.

    1979-01-01

    A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

  9. Heat pipe

    International Nuclear Information System (INIS)

    Triggs, G.W.; Lightowlers, R.J.; Robinson, D.; Rice, G.

    1986-01-01

    A heat pipe for use in stabilising a specimen container for irradiation of specimens at substantially constant temperature within a liquid metal cooled fast reactor, comprises an evaporator section, a condenser section, an adiabatic section therebetween, and a gas reservoir, and contains a vapourisable substance such as sodium. The heat pipe further includes a three layer wick structure comprising an outer relatively fine mesh layer, a coarse intermediate layer and a fine mesh inner layer for promoting unimpeded return of condensate to the evaporation section of the heat pipe while enhancing heat transfer with the heat pipe wall and reducing entrainment of the condensate by the upwardly rising vapour. (author)

  10. Defining and Predicting Heat Waves in Bangladesh

    NARCIS (Netherlands)

    Nissan, H.; Burkart, K.; Coughlan, E.R.; van Aalst, M.; Mason, S.

    2017-01-01

    This paper proposes a heat-wave definition for Bangladesh that could be used to trigger preparedness measures in a heat early warning system (HEWS) and explores the climate mechanisms associated with heat waves. A HEWSrequires a definition of heat waves that is both related to human health outcomes

  11. 17-DMAG induces heat shock protein 90 functional impairment in human bladder cancer cells: knocking down the hallmark traits of malignancy.

    Science.gov (United States)

    Karkoulis, Panagiotis K; Stravopodis, Dimitrios J; Voutsinas, Gerassimos E

    2016-05-01

    Heat shock protein 90 (Hsp90) is a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in multiple oncogenic signaling pathways. Hsp90 holds a prominent role in tumorigenesis, as numerous members of its broad clientele are involved in the generation of the hallmark traits of cancer. 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) specifically targets Hsp90 and interferes with its function as a molecular chaperone, impairing its intrinsic ATPase activity and undermining proper folding of multiple protein clients. In this study, we have examined the effects of 17-DMAG on the regulation of Hsp90-dependent tumorigenic signaling pathways directly implicated in cell cycle progression, survival, and motility of human urinary bladder cancer cell lines. We have used MTT-based assays, FACS analysis, Western blotting, semiquantitative PCR (sqPCR), immunofluorescence, and scratch-wound assays in RT4 (p53(wt)), RT112 (p53(wt)), T24 (p53(mt)), and TCCSUP (p53(mt)) human urinary bladder cancer cell lines. We have demonstrated that, upon exposure to 17-DMAG, bladder cancer cells display prominent cell cycle arrest and commitment to apoptotic and autophagic cell death, in a dose-dependent manner. Furthermore, 17-DMAG administration induced pronounced downregulation of multiple Hsp90 protein clients and other downstream oncogenic effectors, therefore causing inhibition of cell proliferation and decline of cell motility due to the molecular "freezing" of critical cytoskeletal components. In toto, we have clearly demonstrated the dose-dependent and cell type-specific effects of 17-DMAG on the hallmark traits of cancer, appointing Hsp90 as a key molecular component in bladder cancer targeted therapy.

  12. Involvement of protein kinase C in the mechanism of action of Escherichia coli heat-stable enterotoxin (STa) in a human colonic carcinoma cell line, COLO-205

    International Nuclear Information System (INIS)

    Gupta, Dyuti Datta; Saha, Subhrajit; Chakrabarti, Manoj K.

    2005-01-01

    The present study was undertaken to determine the involvement of calcium-protein kinase C pathway in the mechanism of action of Escherichia coli heat stable enterotoxin (STa) apart from STa-induced activation of guanylate cyclase in human colonic carcinoma cell line COLO-205, which was used as a model cultured cell line to study the mechanism of action of E. coli STa. In response to E. coli STa, protein kinase C (PKC) activity was increased in a time-dependent manner with its physical translocation from cytosol to membrane. Inhibition of the PKC activity in membrane fraction and inhibition of its physical translocation in response to IP 3 -mediated calcium release inhibitor dantrolene suggested the involvement of intracellular store depletion in the regulation of PKC activity. Among different PKC isoforms, predominant involvement of calcium-dependent protein kinase C (PKCα) was specified using isotype-specific pseudosubstrate, which showed pronounce enzyme activity. Inhibition of enzyme activity by PKCα-specific inhibitor Goe6976 and immunoblott study employing isotype-specific antibody further demonstrated the involvement of calcium-dependent isoform of PKC in the mechanism of action of E. coli STa. Moreover, inhibition of guanylate cyclase activity by PKCα-specific inhibitor Goe6976 suggested the involvement of PKCα in the regulation of guanylate cyclase activity

  13. Quantitative analyses of postmortem heat shock protein mRNA profiles in the occipital lobes of human cerebral cortices: implications in cause of death.

    Science.gov (United States)

    Chung, Ukhee; Seo, Joong-Seok; Kim, Yu-Hoon; Son, Gi Hoon; Hwang, Juck-Joon

    2012-11-01

    Quantitative RNA analyses of autopsy materials to diagnose the cause and mechanism of death are challenging tasks in the field of forensic molecular pathology. Alterations in mRNA profiles can be induced by cellular stress responses during supravital reactions as well as by lethal insults at the time of death. Here, we demonstrate that several gene transcripts encoding heat shock proteins (HSPs), a gene family primarily responsible for cellular stress responses, can be differentially expressed in the occipital region of postmortem human cerebral cortices with regard to the cause of death. HSPA2 mRNA levels were higher in subjects who died due to mechanical asphyxiation (ASP), compared with those who died by traumatic injury (TI). By contrast, HSPA7 and A13 gene transcripts were much higher in the TI group than in the ASP and sudden cardiac death (SCD) groups. More importantly, relative abundances between such HSP mRNA species exhibit a stronger correlation to, and thus provide more discriminative information on, the death process than does routine normalization to a housekeeping gene. Therefore, the present study proposes alterations in HSP mRNA composition in the occipital lobe as potential forensic biological markers, which may implicate the cause and process of death.

  14. Functional MRI brain imaging studies using the Contact Heat Evoked Potential Stimulator (CHEPS in a human volunteer topical capsaicin pain model

    Directory of Open Access Journals (Sweden)

    Shenoy R

    2011-10-01

    Full Text Available Ravikiran Shenoy1, Katherine Roberts1, Anastasia Papadaki2, Donald McRobbie2, Maarten Timmers3, Theo Meert3, Praveen Anand11Peripheral Neuropathy Unit, Hammersmith Hospital, Imperial College London; 2Imaging Sciences Department, Charing Cross Hospital, London, United Kingdom; 3Johnson and Johnson Pharmaceutical Research and Development, Beerse, BelgiumAbstract: Acute application of topical capsaicin produces spontaneous burning and stinging pain similar to that seen in some neuropathic states, with local hyperalgesia. Use of capsaicin applied topically or injected intradermally has been described as a model for neuropathic pain, with patterns of activation in brain regions assessed using functional magnetic resonance imaging (fMRI and positron emission tomography. The Contact Heat Evoked Potential Stimulator (CHEPS is a noninvasive clinically practical method of stimulating cutaneous A-delta nociceptors. In this study, topical capsaicin (1% was applied to the left volar forearm for 15 minutes of twelve adult healthy human volunteers. fMRI scans and a visual analog pain score were recorded during CHEPS stimulation precapsaicin and postcapsaicin application. Following capsaicin application there was a significant increase in visual analog scale (mean ± standard error of the mean; precapsaicin 26.4 ± 5.3; postcapsaicin 48.9 ± 6.0; P < 0.0001. fMRI demonstrated an overall increase in areas of activation, with a significant increase in the contralateral insular signal (mean ± standard error of the mean; precapsaicin 0.434 ± 0.03; postcapsaicin 0.561 ± 0.07; P = 0.047. The authors of this paper recently published a study in which CHEPS-evoked A-delta cerebral potential amplitudes were found to be decreased postcapsaicin application. In patients with neuropathic pain, evoked pain and fMRI brain responses are typically increased, while A-delta evoked potential amplitudes are decreased. The protocol of recording fMRI following CHEPS stimulation

  15. Modelling heat transfer in humans

    NARCIS (Netherlands)

    Frijns, A.J.H.; Leeuwen, van G.M.J.; Steenhoven, van A.A.

    2006-01-01

    Temperature plays an important role in the functioning of biological systems. To predict tissue temperatures, the influence of blood flow must be accounted for. The collective effect of blood vessels in a tissue volume may be reasonably successfully described by a heatsink. This is for instance the

  16. Heat exchanger

    International Nuclear Information System (INIS)

    Leigh, D.G.

    1976-01-01

    The arrangement described relates particularly to heat exchangers for use in fast reactor power plants, in which heat is extracted from the reactor core by primary liquid metal coolant and is then transferred to secondary liquid metal coolant by means of intermediate heat exchangers. One of the main requirements of such a system, if used in a pool type fast reactor, is that the pressure drop on the primary coolant side must be kept to a minimum consistent with the maintenance of a limited dynamic head in the pool vessel. The intermediate heat exchanger must also be compact enough to be accommodated in the reactor vessel, and the heat exchanger tubes must be available for inspection and the detection and plugging of leaks. If, however, the heat exchanger is located outside the reactor vessel, as in the case of a loop system reactor, a higher pressure drop on the primary coolant side is acceptable, and space restriction is less severe. An object of the arrangement described is to provide a method of heat exchange and a heat exchanger to meet these problems. A further object is to provide a method that ensures that excessive temperature variations are not imposed on welded tube joints by sudden changes in the primary coolant flow path. Full constructional details are given. (U.K.)

  17. Direct Heat

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P J

    1990-01-01

    Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

  18. Plasma heating

    International Nuclear Information System (INIS)

    Wilhelm, R.

    1989-01-01

    Successful plasma heating is essential in present fusion experiments, for the demonstration of DpT burn in future devices and finally for the fusion reactor itself. This paper discusses the common heating systems with respect to their present performance and their applicability to future fusion devices. The comparative discussion is oriented to the various function of heating, which are: - plasma heating to fusion-relevant parameters and to ignition in future machines, -non-inductive, steady-pstate current drive, - plasma profile control, -neutral gas breakdown and plasma build-up. In view of these different functions, the potential of neutral beam injection (NBI) and the various schemes of wave heating (ECRH, LH, ICRH and Alven wave heating) is analyzed in more detail. The analysis includes assessments of the present physical and technical state of these heating methods, and makes suggestions for future developments and about outstanding problems. Specific attention is given to the still critical problem of efficient current drive, especially with respect to further extrapolation towards an economically operating tokamak reactor. Remarks on issues such as reliability, maintenance and economy conclude this comparative overview on plasma heating systems. (author). 43 refs.; 13 figs.; 3 tabs

  19. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

    2010-01-01

    -body heating after intravascular volume expansion. Volume expansion was accomplished by administration of a combination of a synthetic colloid (HES 130/0.4, Voluven) and saline. Before LBNP, SV was not affected by heating (122 +/- 30 ml; mean +/- s.d.) compared to normothermia (110 +/- 20 ml; P = 0...

  20. Pifithrin-μ, an inhibitor of heat-shock protein 70, can increase the antitumor effects of hyperthermia against human prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Kazumasa Sekihara

    Full Text Available Hyperthermia (HT improves the efficacy of anti-cancer radiotherapy and chemotherapy. However, HT also inevitably evokes stress responses and increases the expression of heat-shock proteins (HSPs in cancer cells. Among the HSPs, HSP70 is known as a pro-survival protein. In this study, we investigated the sensitizing effect of pifithrin (PFT-μ, a small molecule inhibitor of HSP70, when three human prostate cancer cell lines (LNCaP, PC-3, and DU-145 were treated with HT (43°C for 2 h. All cell lines constitutively expressed HSP70, and HT further increased its expression in LNCaP and DU-145. Knockdown of HSP70 with RNA interference decreased the viability and colony-forming ability of cancer cells. PFT-μ decreased the viabilities of all cell lines at one-tenth the dose of Quercetin, a well-known HSP inhibitor. The combination therapy with suboptimal doses of PFT-μ and HT decreased the viability of cancer cells most effectively when PFT-μ was added immediately before HT, and this combination effect was abolished by pre-knockdown of HSP70, suggesting that the effect was mediated via HSP70 inhibition. The combination therapy induced cell death, partially caspase-dependent, and decreased proliferating cancer cells, with decreased expression of c-Myc and cyclin D1 and increased expression of p21(WAF1/Cip, indicating arrest of cell growth. Additionally, the combination therapy significantly decreased the colony-forming ability of cancer cells compared to therapy with either alone. Furthermore, in a xenograft mouse model, the combination therapy significantly inhibited PC-3 tumor growth. These findings suggest that PFT-μ can effectively enhance HT-induced antitumor effects via HSP70 inhibition by inducing cell death and arrest of cell growth, and that PFT-μ is a promising agent for use in combination with HT to treat prostate cancer.

  1. Anti-citrullinated protein antibodies promote apoptosis of mature human Saos-2 osteoblasts via cell-surface binding to citrullinated heat shock protein 60.

    Science.gov (United States)

    Lu, Ming-Chi; Yu, Chia-Li; Yu, Hui-Chun; Huang, Hsien-Bin; Koo, Malcolm; Lai, Ning-Sheng

    2016-01-01

    We hypothesized that anti-citrullinated protein antibodies (ACPAs) react with osteoblast surface citrullinated proteins and affect cell function, leading to joint damage in patients with rheumatoid arthritis (RA). First, we purified ACPAs by cyclic citrullinated peptide (CCP)-conjugated affinity column chromatography. The cognate antigens of ACPAs on Saos-2 cells, a sarcoma osteogenic cell line generated from human osteoblasts, were probed by ACPAs, and the reactive bands were analyzed using proteomic analyses. We found that ACPAs bind to Saos-2 cell membrane, and several protein candidates, including HSP60, were identified. We then cloned and purified recombinant heat shock protein 60 (HSP60) and citrullinated HSP60 (citHSP60) and investigated the effect of ACPAs on Saos-2 cell. We confirmed that HSP60 obtained from Saos-2 cell membrane were citrullinated and reacted with ACPAs, which induces Saos-2 cells apoptosis via binding to surface-expressed citHSP60 through Toll-like receptor 4 signaling. ACPAs promoted interleukin (IL)-6 and IL-8 expression in Saos-2 cells. Finally, sera from patients with RA and healthy controls were examined for their titers of anti-HSP60 and anti-citHSP60 antibodies using an enzyme-linked immunosorbent assay. The radiographic change in patients with RA was evaluated using the Genant-modified Sharp scoring system. Patients with RA showed higher sera titers of anti-citHSP60, but not anti-HSP60, antibodies when compared with controls. In addition, the anti-citHSP60 level was positively associated with increased joint damage in patients with RA. In conclusion, Saos-2 cell apoptosis was mediated by ACPAs via binding to cell surface-expressed citHSP60 and the titer of anti-citHSP60 in patients with RA positively associated with joint damage. Copyright © 2015 Elsevier GmbH. All rights reserved.

  2. Recombinant heat shock protein 27 (HSP27/HSPB1) protects against cadmium-induced oxidative stress and toxicity in human cervical cancer cells.

    Science.gov (United States)

    Alvarez-Olmedo, Daiana G; Biaggio, Veronica S; Koumbadinga, Geremy A; Gómez, Nidia N; Shi, Chunhua; Ciocca, Daniel R; Batulan, Zarah; Fanelli, Mariel A; O'Brien, Edward R

    2017-05-01

    Cadmium (Cd) is a carcinogen with several well-described toxicological effects in humans, but its molecular mechanisms are still not fully understood. Overexpression of heat shock protein 27 (HSP27/HSPB1)-a multifunctional protein chaperone-has been shown to protect cells from oxidative damage and apoptosis triggered by Cd exposure. The aims of this work were to investigate the potential use of extracellular recombinant HSP27 to prevent/counteract Cd-induced cellular toxicity and to evaluate if peroxynitrite was involved in the development of Cd-induced toxicity. Here, we report that the harmful effects of Cd correlated with changes in oxidative stress markers: upregulation of reactive oxygen species, reduction in nitric oxide (NO) bioavailability, increment in lipid peroxidation, peroxynitrite (PN), and protein nitration; intracellular HSP27 was reduced. Treatments with Cd (100 μM) for 24 h or with the peroxynitrite donor, SIN-1, decreased HSP27 levels (~50%), suggesting that PN formation is responsible for the reduction of HSP27. Pre-treatments of the cells either with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) (a pharmacological inhibitor of NO synthase) or with recombinant HSP27 (rHSP27) attenuated the disruption of the cellular metabolism induced by Cd, increasing in a 55 and 52%, respectively, the cell viability measured by CCK-8. Cd induced necrotic cell death pathways, although apoptosis was also activated; pre-treatment with L-NAME or rHSP27 mitigated cell death. Our findings show for the first time a direct relationship between Cd-induced toxicity and PN production and a role for rHSP27 as a potential therapeutic agent that may counteract Cd toxicity.

  3. Heat Stroke

    DEFF Research Database (Denmark)

    Mørch, Sofie Søndergaard; Andersen, Johnny Dohn Holmgren; Bestle, Morten Heiberg

    2017-01-01

    not diagnosed until several days after admittance; hence treatment with cooling was delayed. Both patients were admitted to the intensive care unit, where they were treated with an external cooling device and received treatment for complications. Both cases ended fatally. As global warming continues, more heat......Heat stroke is an acute, life-threatening emergency characterized clinically by elevated body temperature and central nervous system dysfunction. Early recognition and treatment including aggressive cooling and management of life-threatening systemic complications are essential to reduce morbidity...... and mortality. This case report describes two Danish patients diagnosed with heat stroke syndrome during a heat wave in the summer of 2014. Both patients were morbidly obese and had several predisposing illnesses. However since heat stroke is a rare condition in areas with temperate climate, they were...

  4. The induction of heme oxygenase-1 suppresses heat shock protein 90 and the proliferation of human breast cancer cells through its byproduct carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wen-Ying [Department of Pathology, Chi-Mei Hospital, Tainan, Taiwan (China); Department of Pathology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Chen, Yen-Chou [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Shih, Chwen-Ming; Lin, Chun-Mao; Cheng, Chia-Hsiung; Chen, Ku-Chung [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Department of Biochemistry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Lin, Cheng-Wei, E-mail: cwlin@tmu.edu.tw [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Department of Biochemistry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)

    2014-01-01

    Heme oxygenase (HO)-1 is an oxidative stress-response enzyme which catalyzes the degradation of heme into bilirubin, ferric ion, and carbon monoxide (CO). Induction of HO-1 was reported to have antitumor activity; the inhibitory mechanism, however, is still unclear. In the present study, we found that treatment with [Ru(CO){sub 3}Cl{sub 2}]{sub 2} (RuCO), a CO-releasing compound, reduced the growth of human MCF7 and MDA-MB-231 breast cancer cells. Analysis of growth-related proteins showed that treatment with RuCO down-regulated cyclinD1, CDK4, and hTERT protein expressions. Interestingly, RuCO treatment resulted in opposite effects on wild-type and mutant p53 proteins. These results were similar to those of cells treated with geldanamycin (a heat shock protein (HSP)90 inhibitor), suggesting that RuCO might affect HSP90 activity. Moreover, RuCO induced mutant p53 protein destabilization accompanied by promotion of ubiquitination and proteasome degradation. The induction of HO-1 by cobalt protoporphyrin IX (CoPP) showed consistent results, while the addition of tin protoporphyrin IX (SnPP), an HO-1 enzymatic inhibitor, diminished the RuCO-mediated effect. RuCO induction of HO-1 expression was reduced by a p38 mitogen-activated protein kinase inhibitor (SB203580). Additionally, treatment with a chemopreventive compound, curcumin, induced HO-1 expression accompanied with reduction of HSP90 client protein expression. The induction of HO-1 by curcumin inhibited 12-O-tetradecanoyl-13-acetate (TPA)-elicited matrix metalloproteinase-9 expression and tumor invasion. In conclusion, we provide novel evidence underlying HO-1's antitumor mechanism. CO, a byproduct of HO-1, suppresses HSP90 protein activity, and the induction of HO-1 may possess potential as a cancer therapeutic. - Highlights: • CO and HO-1 inhibited the growth of human breast cancer cells. • CO and HO-1 attenuated HSP90 and its client proteins expression. • CO induced mutant p53 protein

  5. Modelling the impact of blood flow on the temperature distribution in the human eye and the orbit: fixed heat transfer coefficients versus the Pennes bioheat model versus discrete blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Flyckt, V M M; Raaymakers, B W; Lagendijk, J J W [Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

    2006-10-07

    Prediction of the temperature distribution in the eye depends on how the impact of the blood flow is taken into account. Three methods will be compared: a simplified eye anatomy that applies a single heat transfer coefficient to describe all heat transport mechanisms between the sclera and the body core, a detailed eye anatomy in which the blood flow is accounted for either by the bioheat approach, or by including the discrete vasculature in the eye and the orbit. The comparison is done both for rabbit and human anatomies, normo-thermally and when exposed to homogeneous power densities. The first simplified model predicts much higher temperatures than the latter two. It was shown that the eye is very hard to heat when taking physiological perfusion correctly into account. It was concluded that the heat transfer coefficient describing the heat transport from the sclera to the body core reported in the literature for the first simplified model is too low. The bioheat approach is appropriate for a first-order approximation of the temperature distribution in the eye when exposed to a homogeneous power density, but the discrete vasculature down to 0.2 mm in diameter needs to be taken into account when the heterogeneity of the temperature distribution at a mm scale is of interest.

  6. Modelling the impact of blood flow on the temperature distribution in the human eye and the orbit: fixed heat transfer coefficients versus the Pennes bioheat model versus discrete blood vessels

    International Nuclear Information System (INIS)

    Flyckt, V M M; Raaymakers, B W; Lagendijk, J J W

    2006-01-01

    Prediction of the temperature distribution in the eye depends on how the impact of the blood flow is taken into account. Three methods will be compared: a simplified eye anatomy that applies a single heat transfer coefficient to describe all heat transport mechanisms between the sclera and the body core, a detailed eye anatomy in which the blood flow is accounted for either by the bioheat approach, or by including the discrete vasculature in the eye and the orbit. The comparison is done both for rabbit and human anatomies, normo-thermally and when exposed to homogeneous power densities. The first simplified model predicts much higher temperatures than the latter two. It was shown that the eye is very hard to heat when taking physiological perfusion correctly into account. It was concluded that the heat transfer coefficient describing the heat transport from the sclera to the body core reported in the literature for the first simplified model is too low. The bioheat approach is appropriate for a first-order approximation of the temperature distribution in the eye when exposed to a homogeneous power density, but the discrete vasculature down to 0.2 mm in diameter needs to be taken into account when the heterogeneity of the temperature distribution at a mm scale is of interest

  7. Differences in the heat stress associated with white sportswear and being semi-nude in exercising humans under conditions of radiant heat and wind at a wet bulb globe temperature of greater than 28 °C.

    Science.gov (United States)

    Tsuji, Michio; Kume, Masashi; Tuneoka, Hideyuki; Yoshida, Tetsuya

    2014-08-01

    This study investigated whether wearing common white sportswear can reduce heat stress more than being semi-nude during exercise of different intensities performed under radiant heat and wind conditions, such as a hot summer day. After a 20-min rest period, eight male subjects performed three 20 min sessions of cycling exercise at a load intensity of 20 % or 50 % of their peak oxygen uptake (VO2peak) in a room maintained at a wet bulb globe temperature (WBGT) of 28.7 ± 0.1 °C using two spot lights and a fan (0.8 m/s airflow). Subjects wore common white sportswear (WS) consisting of a long-sleeved shirt (45 % cotton and 55 % polyester) and short pants (100 % polyester), or only swimming pants (SP) under the semi-nude condition. The mean skin temperature (Tsk) was greater when subjects wore SP than WS under both the 20 % and 50 % exercise conditions. During the 50 % exercise, the rating of perceived exertion (RPE) and thermal sensation (TS), and the increases in esophageal temperature (ΔTes) and heart rate were significantly higher (Pheat storage (S), calculated from the changes in the mean body temperature (0.9Tes + 0.1 Tsk), was significantly lower in the WS trials than in the SP trials during the 20 min resting period before exercise session. However, S was similar between conditions during the 20 % exercise, but was greater in the WS than in the SP trials during 50 % exercise. These results suggest that, under conditions of radiant heat and wind at a WBGT greater than 28 °C, the heat stress associated with wearing common WS is similar to that of being semi-nude during light exercise, but was greater during moderate exercise, and the storage of body heat can be reduced by wearing WS during rest periods.

  8. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1994-01-01

    It is approximately 10 years since the Third Edition of Heat Pipes was published and the text is now established as the standard work on the subject. This new edition has been extensively updated, with revisions to most chapters. The introduction of new working fluids and extended life test data have been taken into account in chapter 3. A number of new types of heat pipes have become popular, and others have proved less effective. This is reflected in the contents of chapter 5. Heat pipes are employed in a wide range of applications, including electronics cooling, diecasting and injection mo

  9. Heat conduction

    International Nuclear Information System (INIS)

    Grigull, U.; Sandner, H.

    1984-01-01

    Included are discussions of rates of heat transfer by conduction, the effects of varying and changing properties, thermal explosions, distributed heat sources, moving heat sources, and non-steady three-dimensional conduction processes. Throughout, the importance of thinking both numerically and symbolically is stressed, as this is essential to the development of the intuitive understanding of numerical values needed for successful designing. Extensive tables of thermophysical properties, including thermal conductivity and diffusivity, are presented. Also included are exact and approximate solutions to many of the problems that arise in practical situations

  10. Differences in the heat stress associated with white sportswear and being semi-nude in exercising humans under conditions of radiant heat and wind at a wet bulb globe temperature of greater than 28 °C

    Science.gov (United States)

    Tsuji, Michio; Kume, Masashi; Tuneoka, Hideyuki; Yoshida, Tetsuya

    2014-08-01

    This study investigated whether wearing common white sportswear can reduce heat stress more than being semi-nude during exercise of different intensities performed under radiant heat and wind conditions, such as a hot summer day. After a 20-min rest period, eight male subjects performed three 20 min sessions of cycling exercise at a load intensity of 20 % or 50 % of their peak oxygen uptake (VO2peak) in a room maintained at a wet bulb globe temperature (WBGT) of 28.7 ± 0.1 °C using two spot lights and a fan (0.8 m/s airflow). Subjects wore common white sportswear (WS) consisting of a long-sleeved shirt (45 % cotton and 55 % polyester) and short pants (100 % polyester), or only swimming pants (SP) under the semi-nude condition. The mean skin temperature was greater when subjects wore SP than WS under both the 20 % and 50 % exercise conditions. During the 50 % exercise, the rating of perceived exertion (RPE) and thermal sensation (TS), and the increases in esophageal temperature (ΔTes) and heart rate were significantly higher ( P < 0.001-0.05), or tended to be higher ( P < 0.07), in the WS than SP trials at the end of the third 20-min exercise session. The total sweat loss ( m sw,tot) was also significantly higher in the WS than in the SP trials ( P < 0.05). However, during the 20 % exercise, the m sw,tot during exercise, and the ΔTes, RPE and TS at the end of the second and third sessions of exercise did not differ significant between conditions. The heat storage (S), calculated from the changes in the mean body temperature (0.9Tes + 0.1 ), was significantly lower in the WS trials than in the SP trials during the 20 min resting period before exercise session. However, S was similar between conditions during the 20 % exercise, but was greater in the WS than in the SP trials during 50 % exercise. These results suggest that, under conditions of radiant heat and wind at a WBGT greater than 28 °C, the heat stress associated with wearing common WS is similar to that

  11. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

    2010-01-01

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading...... of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males...... from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole...

  12. District heating

    International Nuclear Information System (INIS)

    Hansen, L.

    1993-01-01

    The environmental risks and uncertainties of a high-energy future are disturbing and give rise to several reservations concerning the use of fossil fuels. A number of technologies will help to reduce atmospheric pollution. In Denmark special importance is attached to the following: Energy conservation. Efficient energy conversion. Renewable energy sources. District heating, combined production of heat and power. Many agree that district heating (DH), produced by the traditional heat-only plant, and combined heat and power (CHP) have enormous potential when considering thermal efficiency and lowered environmental impacts: The basic technology of each is proven, it would be relatively simple to satisfy a substantial part of the energy demand, and their high efficiencies mean reduced pollution including greenhouse gas emissions. This is especially important in high population density areas - the obviously preferred sites for such energy generation. Compared with individual heating DH can provide a community with an operationally efficient and most often also an economically competitive heat supply. This is particularly true under the circumstances where the DH system is supplied from CHP plants. Their use results in very substantial improvements in overall efficiency. Further environmental improvements arise from the reduced air pollution obtainable in reasonably large CHP plants equipped with flue gas cleaning to remove particles, sulphur dioxide, and nitrogen acids. As a consequence of these considerations, DH plays an important role in fulfilling the space and water heating demand in many countries. This is especially the case in Denmark where this technology is utilised to a very great extent. Indeed, DH is one of the reasons why Denmark has relatively good air quality in the cities. (au)

  13. Whole-body fluid distribution in humans during dehydration and recovery, before and after humid-heat acclimation induced using controlled hyperthermia.

    Science.gov (United States)

    Patterson, M J; Stocks, J M; Taylor, N A S

    2014-04-01

    This experiment was designed to test the hypothesis that the plasma volume is not selectively defended during exercise- and heat-induced dehydration following humid-heat acclimation. Eight physically active males were heat acclimated (39.8 °C, relative humidity 59.2%) using 17 days of controlled hyperthermia (core temperature: 38.5 °C). Inter-compartmental fluid losses and movements were tracked (radioisotopes and Evans blue dye) during progressive dehydration (cycling) in these same conditions and also during a resting recovery without fluid replacement (28 °C), before (day 1), during (day 8) and after heat acclimation (day 22). On days 8 and 22, there were significant increases in total body water, interstitial fluid and plasma volume (P 0.05). The baseline plasma volume remained expanded throughout: 43.4 [±2.6 (day 1)], 49.1 [±2.4 (day 8); P recovery, plasma volume restoration commenced, with the intracellular fluid contribution becoming more pronounced as acclimation progressed. It is concluded that the plasma volume was not defended more vigorously following humid-heat acclimation. Indeed, a greater fluid loss may well underlie the mechanisms for enhancing plasma volume recovery when heat acclimation is induced using the controlled-hyperthermia technique. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  14. Amplification and high-level expression of heat shock protein 90 marks aggressive phenotypes of human epidermal growth factor receptor 2 negative breast cancer.

    Science.gov (United States)

    Cheng, Qing; Chang, Jeffrey T; Geradts, Joseph; Neckers, Leonard M; Haystead, Timothy; Spector, Neil L; Lyerly, H Kim

    2012-04-17

    Although human epidermal growth factor receptor 2 (HER2) positive or estrogen receptor (ER) positive breast cancers are treated with clinically validated anti-HER2 or anti-estrogen therapies, intrinsic and acquired resistance to these therapies appears in a substantial proportion of breast cancer patients and new therapies are needed. Identification of additional molecular factors, especially those characterized by aggressive behavior and poor prognosis, could prioritize interventional opportunities to improve the diagnosis and treatment of breast cancer. We compiled a collection of 4,010 breast tumor gene expression data derived from 23 datasets that have been posted on the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database. We performed a genome-scale survival analysis using Cox-regression survival analyses, and validated using Kaplan-Meier Estimates survival and Cox Proportional-Hazards Regression survival analyses. We conducted a genome-scale analysis of chromosome alteration using 481 breast cancer samples obtained from The Cancer Genome Atlas (TCGA), from which combined expression and copy number data were available. We assessed the correlation between somatic copy number alterations and gene expression using analysis of variance (ANOVA). Increased expression of each of the heat shock protein (HSP) 90 isoforms, as well as HSP transcriptional factor 1 (HSF1), was correlated with poor prognosis in different subtypes of breast cancer. High-level expression of HSP90AA1 and HSP90AB1, two cytoplasmic HSP90 isoforms, was driven by chromosome coding region amplifications and were independent factors that led to death from breast cancer among patients with triple-negative (TNBC) and HER2-/ER+ subtypes, respectively. Furthermore, amplification of HSF1 was correlated with higher HSP90AA1 and HSP90AB1 mRNA expression among the breast cancer cells without amplifications of these two genes. A collection of HSP90AA1, HSP90AB1 and HSF

  15. Acclimatization to extreme heat

    Science.gov (United States)

    Warner, M. E.; Ganguly, A. R.; Bhatia, U.

    2017-12-01

    Heat extremes throughout the globe, as well as in the United States, are expected to increase. These heat extremes have been shown to impact human health, resulting in some of the highest levels of lives lost as compared with similar natural disasters. But in order to inform decision makers and best understand future mortality and morbidity, adaptation and mitigation must be considered. Defined as the ability for individuals or society to change behavior and/or adapt physiologically, acclimatization encompasses the gradual adaptation that occurs over time. Therefore, this research aims to account for acclimatization to extreme heat by using a hybrid methodology that incorporates future air conditioning use and installation patterns with future temperature-related time series data. While previous studies have not accounted for energy usage patterns and market saturation scenarios, we integrate such factors to compare the impact of air conditioning as a tool for acclimatization, with a particular emphasis on mortality within vulnerable communities.

  16. Impact of Human Activity on Local Climate Change in Veľké Turovce by Heating and Possibilities for Carbon Dioxide Decrease

    Directory of Open Access Journals (Sweden)

    Hudec Matej

    2014-12-01

    Full Text Available The paper is aimed at detecting CO2 emissions from heating process of households in Veľké Turovce. It offers solutions for 100 % and 20 % replacement of conventional fuels by solar collector systems. In the village, 242 households heat by natural gas during average length of 21 weeks a year. Average amount of energy consumed in heating process after conversion is 18,503.06 kWh per household. For 100 % replacement of natural gas, 63 units of vacuum tube solar collector type Watt CP C 9 are required. In average duration of 23 weeks a year, 12 households heat by brown coal with average consumption of 20,339.75 kWh. For complete replacement, 69 pieces of solar collectors are required. The remaining 18 households heat by firewood in average duration of 22 week a year. The consumption of one household represents in average 19,125.07 kWh. In this case, the replacement of 100 % of firewood energy requires 65 pieces of solar panels. The amounts of saved CO2 emissions by collector system replacing 100 % of natural gas represent 926,336.39 kg of CO2 for 242 households. For 12 households heated by brown coal, it represents 152,767.65 kg of saved CO2 emissions. Last but not least, 30,553.53 kg of CO2 represent the amount of saved CO2 emission for 18 households heating by firewood. Prices of collector systems in case of 100 % replacement of conventional fuels would be 37,111.45 € for natural gas, 40,356.79 € for brown coal, and 38,203.23 € in case of replacement of firewood

  17. Differential effect of gamma-irradiated and heat-treated lymphocytes on T cell activation, and interleukin-2 and interleukin-3 release in the human mixed lymphocyte reaction

    International Nuclear Information System (INIS)

    Loertscher, R.; Abbud-Filho, M.; Leichtman, A.B.; Ythier, A.A.; Williams, J.M.; Carpenter, C.B.; Strom, T.B.

    1987-01-01

    Heat-inactivated (45 degrees C/1 hr) lymphocytes selectively activate suppressor T cells in the mixed lymphocyte reaction (MLR), while no significant proliferation and cytotoxic T lymphocyte activation can be detected. It is not well understood why hyperthermic treatment abolishes the stimulatory capacity of lymphocytes since HLA-DR molecules remain detectable immediately following heat exposure. In order to further characterize the requirements for Ts activation we studied the effects of hyperthermic treatment on cellular protein and DNA synthesis and cell surface protein expression in proliferating T and B cells; interleukin (IL)-1, IL-2, and IL-3 release following allogeneic stimulation with heat treated cells (HMLR); and IL-2 receptor expression as an indicator of T cell activation in the HMLR. Hyperthermic treatment reduced cellular protein synthesis as estimated by 14 C-leucine uptake to about 15%, and DNA synthesis ( 3 H-thymidine incorporation) to about 5% of untreated control cells. In contrast to y-irradiated cells, viability of heated cells rapidly declined within the first 24 hr. Hyperthermic treatment doubled binding of mouse immunoglobulin paralleled by an increased expression of IL-2 and transferrin receptors, while expression of HLA-DR and 4F2 proteins appeared unchanged. Stimulation with heated cells triggered the release of IL-1- and an IL-3-like bioactivity but did not induce IL-2 synthesis and/or release, thus explaining the lack of proliferation in the HMLR. Addition of exogenous IL-2 but not IL-1 restored HMLR proliferation. A comparison of allostimulation with y-irradiated and heat-treated cells revealed that significantly fewer T cells were induced to express IL-2 receptors at day 3 (14% vs. 8%, P less than 0.001) and at day 6 (42% vs. 21%, P less than 0.05) with heat-inactivated stimulators

  18. Review: heat pipe heat exchangers at IROST

    OpenAIRE

    E. Azad

    2012-01-01

    The use of the heat pipe as a component in a heat recovery device has gained worldwide acceptance. Heat pipes are passive, highly reliable and offer high heat transfer rates. This study summarizes the investigation of different types of heat pipe heat recovery systems (HPHRSs). The studies are classified on the basis of the type of the HPHRS. This research is based on 30 years of experience on heat pipe and heat recovery systems that are presented in this study. Copyright , Oxford University ...

  19. Heat pipes and heat pipe exchangers for heat recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, L L; Grakovich, L P; Kiselev, V G; Kurustalev, D K; Matveev, Yu

    1984-01-01

    Heat pipes and heat pipe exchangers are of great importance in power engineering as a means of recovering waste heat of industrial enterprises, solar energy, geothermal waters and deep soil. Heat pipes are highly effective heat transfer units for transferring thermal energy over large distance (tens of meters) with low temperature drops. Their heat transfer characteristics and reliable working for more than 10-15 yr permit the design of new systems with higher heat engineering parameters.

  20. Unwanted heat

    International Nuclear Information System (INIS)

    Benka, M.

    2006-01-01

    The number of small heating plants using biomass is growing. According to TREND's information, Hrinovska energeticka, is the only one that controls the whole supplier chain in cooperation with its parent company in Bratislava. Starting with the collection and processing of wood chips by burning, heat production and heat distribution to the end user. This gives the company better control over costs and consequently its own prices. Last year, the engineering company, Hrinovske storjarne, decided to focus only on its core business and sold its heating plant, Hrinovske tepelne hospodarstvo, to Intech Slovakia and changed the company name to Hrinovska energeticka. Local companies and inhabitants were concerned that the new owner would increase prices. But the company publicly declared and kept promises that the heat price for households would remain at 500 Slovak crowns/gigajoule (13.33 EUR/gigajoule ), one of the lowest prices in Slovakia. This year the prices increased slightly to 570 Slovak crowns (15.2 EUR). 'We needed - even at the cost of lower profit - to satisfy our customers so that we would not lose them. We used this time for transition to biomass. This will allow us to freeze our prices in the coming years,' explained the statutory representative of the company, Ivan Dudak. (authors)

  1. Heat Pipes

    Science.gov (United States)

    1990-01-01

    Bobs Candies, Inc. produces some 24 million pounds of candy a year, much of it 'Christmas candy.' To meet Christmas demand, it must produce year-round. Thousands of cases of candy must be stored a good part of the year in two huge warehouses. The candy is very sensitive to temperature. The warehouses must be maintained at temperatures of 78-80 degrees Fahrenheit with relative humidities of 38- 42 percent. Such precise climate control of enormous buildings can be very expensive. In 1985, energy costs for the single warehouse ran to more than 57,000 for the year. NASA and the Florida Solar Energy Center (FSEC) were adapting heat pipe technology to control humidity in building environments. The heat pipes handle the jobs of precooling and reheating without using energy. The company contacted a FSEC systems engineer and from that contact eventually emerged a cooperative test project to install a heat pipe system at Bobs' warehouses, operate it for a period of time to determine accurately the cost benefits, and gather data applicable to development of future heat pipe systems. Installation was completed in mid-1987 and data collection is still in progress. In 1989, total energy cost for two warehouses, with the heat pipes complementing the air conditioning system was 28,706, and that figures out to a cost reduction.

  2. Monopole heat

    International Nuclear Information System (INIS)

    Turner, M.S.

    1983-01-01

    Upper bounds on the flux of monopoles incident on the Earth with velocity -5 c(10 16 GeV m -1 ) and on the flux of monopoles incident on Jupiter with velocity -3 c(10 16 GeV m -1 ), are derived. Monopoles moving this slowly lose sufficient energy to be stopped, and then catalyse nucleon decay, releasing heat. The limits are obtained by requiring the rate of energy release from nucleon decay to be less than the measured amount of heat flowing out from the surface of the planet. (U.K.)

  3. Heat exchanger

    International Nuclear Information System (INIS)

    Drury, C.R.

    1988-01-01

    A heat exchanger having primary and secondary conduits in heat-exchanging relationship is described comprising: at least one serpentine tube having parallel sections connected by reverse bends, the serpentine tube constituting one of the conduits; a group of open-ended tubes disposed adjacent to the parallel sections, the open-ended tubes constituting the other of the conduits, and forming a continuous mass of contacting tubes extending between and surrounding the serpentine tube sections; and means securing the mass of tubes together to form a predetermined cross-section of the entirety of the mass of open-ended tubes and tube sections

  4. Heat Convection

    Science.gov (United States)

    Jiji, Latif M.

    Professor Jiji's broad teaching experience lead him to select the topics for this book to provide a firm foundation for convection heat transfer with emphasis on fundamentals, physical phenomena, and mathematical modelling of a wide range of engineering applications. Reflecting recent developments, this textbook is the first to include an introduction to the challenging topic of microchannels. The strong pedagogic potential of Heat Convection is enhanced by the follow ing ancillary materials: (1) Power Point lectures, (2) Problem Solutions, (3) Homework Facilitator, and, (4) Summary of Sections and Chapters.

  5. Renewable Heating And Cooling

    Science.gov (United States)

    Renewable heating and cooling is a set of alternative resources and technologies that can be used in place of conventional heating and cooling technologies for common applications such as water heating, space heating, space cooling and process heat.

  6. Heat exchanger

    Science.gov (United States)

    Wolowodiuk, Walter

    1976-01-06

    A heat exchanger of the straight tube type in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration.

  7. Heat exchangers

    International Nuclear Information System (INIS)

    1975-01-01

    The tubes of a heat exchanger tube bank have a portion thereof formed in the shape of a helix, of effective radius equal to the tube radius and the space between two adjacent tubes, to tangentially contact the straight sections of the tubes immediately adjacent thereto and thereby provide support, maintain the spacing and account for differential thermal expansion thereof

  8. Heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Harada, F; Yanagida, T; Fujie, K; Futawatari, H

    1975-04-30

    The purpose of this construction is the improvement of heat transfer in finned tube heat exchangers, and therefore the improvement of its efficiency or its output per unit volume. This is achieved by preventing the formation of flow boundary layers in gaseous fluid. This effect always occurs on flow of smooth adjacent laminae, and especially if these have pipes carrying liquid passing through them; it worsens the heat transfer of such a boundary layer considerably compared to that in the turbulent range. The fins, which have several rows of heat exchange tubes passing through them, are fixed at a small spacing on theses tubes. The fins have slots cut in them by pressing or punching, where the pressed-out material remains as a web, which runs parallel to the level of the fin and at a small distance from it. These webs and slots are arranged radially around every tube hole, e.g. 6 in number. For a suitable small tube spacing, two adjacent tubes opposite each other have one common slot. Many variants of such slot arrangements are illustrated.

  9. Heat exchanger

    International Nuclear Information System (INIS)

    Wolowodiuk, W.

    1976-01-01

    A heat exchanger of the straight tube type is described in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration

  10. Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river?

    Directory of Open Access Journals (Sweden)

    H. Trimmel

    2018-01-01

    Full Text Available Global warming has already affected European rivers and their aquatic biota, and climate models predict an increase of temperature in central Europe over all seasons. We simulated the influence of expected changes in heat wave intensity during the 21st century on water temperatures of a heavily impacted pre-alpine Austrian river and analysed future mitigating effects of riparian vegetation shade on radiant and turbulent energy fluxes using the deterministic Heat Source model. Modelled stream water temperature increased less than 1.5 °C within the first half of the century. Until 2100, a more significant increase of around 3 °C in minimum, maximum and mean stream temperatures was predicted for a 20-year return period heat event. The result showed clearly that in a highly altered river system riparian vegetation was not able to fully mitigate the predicted temperature rise caused by climate change but would be able to reduce water temperature by 1 to 2 °C. The removal of riparian vegetation amplified stream temperature increases. Maximum stream temperatures could increase by more than 4 °C even in annual heat events. Such a dramatic water temperature shift of some degrees, especially in summer, would indicate a total shift of aquatic biodiversity. The results demonstrate that effective river restoration and mitigation require re-establishing riparian vegetation and emphasize the importance of land–water interfaces and their ecological functioning in aquatic environments.

  11. Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river?

    Science.gov (United States)

    Trimmel, Heidelinde; Weihs, Philipp; Leidinger, David; Formayer, Herbert; Kalny, Gerda; Melcher, Andreas

    2018-01-01

    Global warming has already affected European rivers and their aquatic biota, and climate models predict an increase of temperature in central Europe over all seasons. We simulated the influence of expected changes in heat wave intensity during the 21st century on water temperatures of a heavily impacted pre-alpine Austrian river and analysed future mitigating effects of riparian vegetation shade on radiant and turbulent energy fluxes using the deterministic Heat Source model. Modelled stream water temperature increased less than 1.5 °C within the first half of the century. Until 2100, a more significant increase of around 3 °C in minimum, maximum and mean stream temperatures was predicted for a 20-year return period heat event. The result showed clearly that in a highly altered river system riparian vegetation was not able to fully mitigate the predicted temperature rise caused by climate change but would be able to reduce water temperature by 1 to 2 °C. The removal of riparian vegetation amplified stream temperature increases. Maximum stream temperatures could increase by more than 4 °C even in annual heat events. Such a dramatic water temperature shift of some degrees, especially in summer, would indicate a total shift of aquatic biodiversity. The results demonstrate that effective river restoration and mitigation require re-establishing riparian vegetation and emphasize the importance of land-water interfaces and their ecological functioning in aquatic environments.

  12. Heat pipe heat exchangers in heat recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Stulc, P; Vasiliev, L L; Kiseljev, V G; Matvejev, Ju N

    1985-01-01

    The results of combined research and development activities of the National Research Institute for Machine Design, Prague, C.S.S.R. and the Institute for Heat and Mass Transfer, Minsk, U.S.S.R. concerning intensification heat pipes used in heat pipe heat exchangers are presented. This sort of research has been occasioned by increased interest in heat power economy trying to utilise waste heat produced by various technological processes. The developed heat pipes are deployed in construction of air-air, gas-air or gas-gas heat recovery exchangers in the field of air-engineering and air-conditioning. (author).

  13. Heat exchanger

    International Nuclear Information System (INIS)

    Bennett, J.C.

    1975-01-01

    A heat exchanger such as forms, for example, part of a power steam boiler is made up of a number of tubes that may be arranged in many different ways, and it is necessary that the tubes be properly supported. The means by which the tubes are secured must be as simple as possible so as to facilitate construction and must be able to continue to function effectively under the varying operating conditions to which the heat exchanger is subject. The arrangement described is designed to meet these requirements, in an improved way. The tubes are secured to a member extending past several tubes and abutment means are provided. At least some of the abutment means comprise two abutment pieces and a wedge secured to the supporting member, that acts on these pieces to maintain the engagement. (U.K.)

  14. A PET [18F]altanserin study of 5-HT2A receptor binding in the human brain and responses to painful heat stimulation

    DEFF Research Database (Denmark)

    Kupers, Ronny Clement Florent; Frokjaer, Vibe G; Naert, Arne

    2009-01-01

    There is a large body of evidence that serotonin [5-hydroxytryptamine (5-HT)] plays an important role in the transmission and regulation of pain. Here we used positron emission tomography (PET) to study the relationship between baseline 5-HT(2A) binding in the brain and responses to noxious heat...... stimulation in a group of young healthy volunteers. Twenty-one healthy subjects underwent PET scanning with the 5-HT(2A) antagonist, [(18)F]altanserin. In addition, participants underwent a battery of pain tests using noxious heat stimulation to assess pain threshold, pain tolerance and response to short......-lasting phasic and long-lasting (7-minute) tonic painful stimulation. Significant positive correlations were found between tonic pain ratings and [(18)F]altanserin binding in orbitofrontal (r=0.66; p=0.005), medial inferior frontal (r=0.60; p=0.014), primary sensory-motor (r=0.61; p=0.012) and posterior...

  15. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas - Urban Climate

    Science.gov (United States)

    Human health and well-being are and will be affected by climate change, both directly through changes in extreme weather events and indirectly through weather-induced changes in human and natural systems. Populations are vulnerable to these changes in varying degrees, depending ...

  16. Differential Targeting of Hsp70 Heat Shock Proteins HSPA6 and HSPA1A with Components of a Protein Disaggregation/Refolding Machine in Differentiated Human Neuronal Cells following Thermal Stress

    Directory of Open Access Journals (Sweden)

    Ian R. Brown

    2017-04-01

    Full Text Available Heat shock proteins (Hsps co-operate in multi-protein machines that counter protein misfolding and aggregation and involve DNAJ (Hsp40, HSPA (Hsp70, and HSPH (Hsp105α. The HSPA family is a multigene family composed of inducible and constitutively expressed members. Inducible HSPA6 (Hsp70B' is found in the human genome but not in the genomes of mouse and rat. To advance knowledge of this little studied HSPA member, the targeting of HSPA6 to stress-sensitive neuronal sites with components of a disaggregation/refolding machine was investigated following thermal stress. HSPA6 targeted the periphery of nuclear speckles (perispeckles that have been characterized as sites of transcription. However, HSPA6 did not co-localize at perispeckles with DNAJB1 (Hsp40-1 or HSPH1 (Hsp105α. At 3 h after heat shock, HSPA6 co-localized with these members of the disaggregation/refolding machine at the granular component (GC of the nucleolus. Inducible HSPA1A (Hsp70-1 and constitutively expressed HSPA8 (Hsc70 co-localized at nuclear speckles with components of the machine immediately after heat shock, and at the GC layer of the nucleolus at 1 h with DNAJA1 and BAG-1. These results suggest that HSPA6 exhibits targeting features that are not apparent for HSPA1A and HSPA8.

  17. Appropriate technology for solar energy system aiming water heating for human bath in houses of rural areas; Tecnologia apropriada para sistema de energia solar visando aquecimento de agua para o banho humano em moradias do meio rural

    Energy Technology Data Exchange (ETDEWEB)

    Rispoli, Italo Alberto Gatica [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo], e-mail: gatica@dglnet.com.br; Mariotoni, Carlos Alberto [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Civil, Arquitetura e Urbanismo. Nucleo Interdisciplinar de Planejamento Energetico], e-mail: cam@fec.unicamp.br

    2004-07-01

    The Brazilian land receives a great amount of solar radiation all over the year, therefore, because both the culture and practical aspects, Brazilians use in a non-moderate way the electricity to boil the water for human bath in the rural homes, in the lower income residences even at part of the medium class homes. That happens due to the very low price of an electrical shower, about US$ 6,5. In fact, that way of heating water is largely used because, besides the very low electrical shower price, it is not necessary to install a complete hot water both hydraulic and electrical building systems, but just both single hydraulic pipes and electrical devices. On the other hands, at rural regions where the electricity does not achieve the rural people uses firewood in order to get hot water for human bath. At the rural places the use of electrical showers has meaning an increase in the electrical transformers powers, heavier electrical transmission rural lines, with greater prices and, at the urban zones, the use of electrical showers in the lower social classes has contributed to a more expressive electrical load at the nacional electrical system load peck, between 5:30 to 8:30 a.m. The public administration, mostly, does not take into account both social, economic and environmental costs in order to think about the electricity offer. The solar heating systems, generally used in Brazil, conserves the same reservoirs used in France at 1880. Therefore, this paper presents some technical subsidies applied to rural homes, even to lower income people's homes aiming to stimulate the Brazilian public authorities to make a public police to facilitate both the industrialization and dissemination of solar heating systems, appropriate to the rural area, with lower costs, compounded by good technology equipment, with guarantee of lasting and quality. (author)

  18. Heating networks and domestic central heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Kamler, W; Wasilewski, W

    1976-08-01

    This is a comprehensive survey of the 26 contributions from 8 European countries submitted to the 3rd International District Heating Conference in Warsaw held on the subject 'Heating Networks and Domestic Central Heating Systems'. The contributions are grouped according to 8 groups of subjects: (1) heat carriers and their parameters; (2) system of heating networks; (3) calculation and optimization of heating networks; (4) construction of heating networks; (5) operation control and automation; (6) operational problems; (7) corrosion problems; and (8) methods of heat accounting.

  19. Hydride heat pump with heat regenerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  20. Heating systems for heating subsurface formations

    Science.gov (United States)

    Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  1. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1982-01-01

    A comprehensive, up-to-date coverage of the theory, design and manufacture of heat pipes and their applications. This latest edition has been thoroughly revised, up-dated and expanded to give an in-depth coverage of the new developments in the field. Significant new material has been added to all the chapters and the applications section has been totally rewritten to ensure that topical and important applications are appropriately emphasised. The bibliography has been considerably enlarged to incorporate much valuable new information. Thus readers of the previous edition, which has established

  2. Heat exchanger

    International Nuclear Information System (INIS)

    Dostatni, A.W.; Dostatni, Michel.

    1976-01-01

    In the main patent, a description was given of a heat exchanger with an exchange surface in preformed sheet metal designed for the high pressure and temperature service particularly encountered in nuclear pressurized water reactors and which is characterised by the fact that it is composed of at least one exchanger bundle sealed in a containment, the said bundle or bundles being composed of numerous juxtaposed individual compartments whose exchange faces are built of preformed sheet metal. The present addendun certificate concerns shapes of bundles and their positioning methods in the exchanger containment enabling its compactness to be increased [fr

  3. Regenerative Hydride Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  4. Low temperature nuclear heat

    Energy Technology Data Exchange (ETDEWEB)

    Kotakorpi, J.; Tarjanne, R. [comps.

    1977-08-01

    The meeting was concerned with the use of low grade nuclear heat for district heating, desalination, process heat, and agriculture and aquaculture. The sessions covered applications and demand, heat sources, and economics.

  5. Radiofrequency plasma heating: proceedings

    International Nuclear Information System (INIS)

    Swenson, D.G.

    1985-01-01

    The conference proceedings include sessions on Alfven Wave Heating, ICRF Heating and Current Drive, Lower Hybrid Heating and Current Drive, and ECRF Heating. Questions of confinement, diagnostics, instabilities and technology are considered. Individual papers are cataloged separately

  6. Effect of bidirectional rotation of an acupuncture needle at LI10 on acupuncture needle sensation and experimentally-induced contact heat pain in healthy human volunteers.

    Science.gov (United States)

    Benham, Alex; Johnson, Mark I

    2014-06-01

    There is insufficient evidence of a relationship between acupuncture needle sensations (de qi) and hypoalgesia. The aim of this study was to investigate the effects of bidirectional needle rotation at LI10 on acupuncture needle sensations and heat pain thresholds. Twenty-two healthy participants received one acupuncture needle at LI10 with bidirectional rotation of the needle in one experimental session and one acupuncture needle at LI10 with mock rotation in a separate session, in a randomised order. Measurements of heat pain thresholds were taken before needle insertion, during needle retention and 15 min after needle removal. At each measurement time point, participants rated needle sensations using the Massachusetts Acupuncture Sensation Scale (MASS) and a visual analogue scale (VAS) of overall intensity of needle sensation. Bidirectional needle rotation produced significantly higher scores for VAS, MASStotal, MASSpain and MASSsensation compared with mock rotation (all psensation and change in pain threshold after needling was only found when data from mock and rotation interventions were combined. Needle rotation increases the magnitude of hypoalgesia. There is tentative evidence that needle sensation may be associated with the amount of change in pain threshold. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Effect of vibrational stress and spaceflight on regulation of heat shock proteins hsp70 and hsp27 in human lymphocytes (Jurkat)

    Science.gov (United States)

    Cubano, L. A.; Lewis, M. L.

    2001-01-01

    Heat shock protein levels are increased in cells as a result of exposure to stress. To determine whether heat shock protein regulation could be used to evaluate stress in cells during spaceflight, the response of Jurkat cells to spaceflight and simulated space shuttle launch vibration was investigated by evaluating hsp70 and hsp27 gene expression. Gene expression was assessed by reverse transcription-polymerase chain reaction using mRNA extracted from vibrated, nonvibrated, space-flown, and ground control cells. Results indicate that mechanical stresses of vibration and low gravity do not up-regulate the mRNA for hsp70, although the gene encoding hsp27 is up-regulated by spaceflight but not by vibration. In ground controls, the mRNA for hsp70 and hsp27 increased with time in culture. We conclude that hsp70 gene expression is a useful indicator of stress related to culture density but is not an indicator of the stresses of launch vibration or microgravity. Up-regulation of hsp27 gene expression in microgravity is a new finding.

  8. Split heat pipe heat recovery system

    OpenAIRE

    E. Azad

    2008-01-01

    This paper describes a theoretical analysis of a split heat pipe heat recovery system. The analysis is based on an Effectiveness-NTU approach to deduce its heat transfer characteristics. In this study the variation of overall effectiveness of heat recovery with the number of transfer units are presented. Copyright , Manchester University Press.

  9. Electric heating guidelines: power smart home; 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Guidelines, for use by B. C. Hydro, were established for proper planning and design of an electric heating system for residential buildings. The guidebook is divided into five sections: (1) comfort and electric heating systems, (2) contractors` guide to heat loss calculation, (3) imperial heat loss factors, (4) metric heat loss factors, and (5) installation guidelines for electric heating systems. Individual topics discussed include heat loss and the human body, heating systems and comfort, heat loss design, air leakage, and soil conductivity factors. Design considerations and equipment standards were described for the following electric heating systems: electric resistance baseboard systems, forced flow unitary heaters, electric radiant cable in-floor systems, radiant ceiling systems, forced warm air heating systems, furnaces, and heat pumps. 68 tabs., 29 figs.

  10. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  11. Dual source heat pump

    Science.gov (United States)

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  12. CDC WONDER: Daily Air Temperatures and Heat Index

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Daily Air Temperature and Heat Index data available on CDC WONDER are county-level daily average air temperatures and heat index measures spanning the years...

  13. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas presentation

    Science.gov (United States)

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment int...

  14. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas

    Science.gov (United States)

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment interactions. ...

  15. Heat pipes in modern heat exchangers

    International Nuclear Information System (INIS)

    Vasiliev, Leonard L.

    2005-01-01

    Heat pipes are very flexible systems with regard to effective thermal control. They can easily be implemented as heat exchangers inside sorption and vapour-compression heat pumps, refrigerators and other types of heat transfer devices. Their heat transfer coefficient in the evaporator and condenser zones is 10 3 -10 5 W/m 2 K, heat pipe thermal resistance is 0.01-0.03 K/W, therefore leading to smaller area and mass of heat exchangers. Miniature and micro heat pipes are welcomed for electronic components cooling and space two-phase thermal control systems. Loop heat pipes, pulsating heat pipes and sorption heat pipes are the novelty for modern heat exchangers. Heat pipe air preheaters are used in thermal power plants to preheat the secondary-primary air required for combustion of fuel in the boiler using the energy available in exhaust gases. Heat pipe solar collectors are promising for domestic use. This paper reviews mainly heat pipe developments in the Former Soviet Union Countries. Some new results obtained in USA and Europe are also included

  16. Table 1.xlsx

    Indian Academy of Sciences (India)

    Sandra Feijoo Bandin

    60 Kda heat shock protein, mitochondrial. GRP75_MOUSE Stress-70 protein, mitochondrial. PHB_MOUSE. Prohibitin. Biological process. Metabolic process. Glycolysis. Lipid metabolism. Tricarboxylic acid cycle. Respiratory electron transport chain. Muscle contraction. Cellular component organization. Transport.

  17. Manually operated elastomer heat pump

    Science.gov (United States)

    Hutchinson, W. D.

    1970-01-01

    Device consisting of a rotating mechanism, a frame with multiple wide bands of rubber, and a fluid bath, demonstrates the feasibility of a human operated device capable of cooling or producing heat. This invention utilizes the basic thermodynamic properties of natural rubber.

  18. Heat pipe heat exchanger for heat recovery in air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Baky, Mostafa A.; Mohamed, Mousa M. [Mechanical Power Engineering Department, Faculty of Engineering, Minufiya University, Shebin El-Kom (Egypt)

    2007-03-15

    The heat pipe heat exchangers are used in heat recovery applications to cool the incoming fresh air in air conditioning applications. Two streams of fresh and return air have been connected with heat pipe heat exchanger to investigate the thermal performance and effectiveness of heat recovery system. Ratios of mass flow rate between return and fresh air of 1, 1.5 and 2.3 have been adapted to validate the heat transfer and the temperature change of fresh air. Fresh air inlet temperature of 32-40{sup o}C has been controlled, while the inlet return air temperature is kept constant at about 26{sup o}C. The results showed that the temperature changes of fresh and return air are increased with the increase of inlet temperature of fresh air. The effectiveness and heat transfer for both evaporator and condenser sections are also increased to about 48%, when the inlet fresh air temperature is increased to 40{sup o}C. The effect of mass flow rate ratio on effectiveness is positive for evaporator side and negative for condenser side. The enthalpy ratio between the heat recovery and conventional air mixing is increased to about 85% with increasing fresh air inlet temperature. The optimum effectiveness of heat pipe heat exchanger is estimated and compared with the present experimental data. The results showed that the effectiveness is close to the optimum effectiveness at fresh air inlet temperature near the fluid operating temperature of heat pipes. (author)

  19. Nonazeotropic Heat Pump

    Science.gov (United States)

    Ealker, David H.; Deming, Glenn

    1991-01-01

    Heat pump collects heat from water circulating in heat-rejection loop, raises temperature of collected heat, and transfers collected heat to water in separate pipe. Includes sealed motor/compressor with cooling coils, evaporator, and condenser, all mounted in outer housing. Gradients of temperature in evaporator and condenser increase heat-transfer efficiency of vapor-compression cycle. Intended to recover relatively-low-temperature waste heat and use it to make hot water.

  20. Heat transfer: Pittsburgh 1987

    International Nuclear Information System (INIS)

    Lyczkowski, R.W.

    1987-01-01

    This book contains papers divided among the following sections: Process Heat Transfer; Thermal Hydraulics and Phase Change Phenomena; Analysis of Multicomponent Multiphase Flow and Heat Transfer; Heat Transfer in Advanced Reactors; General Heat Transfer in Solar Energy; Numerical Simulation of Multiphase Flow and Heat Transfer; High Temperature Heat Transfer; Heat Transfer Aspects of Severe Reactor Accidents; Hazardous Waste On-Site Disposal; and General Papers

  1. Industrial waste heat for district heating

    International Nuclear Information System (INIS)

    Heitner, K.L.; Brooks, P.P.

    1982-01-01

    Presents 2 bounding evaluations of industrial waste heat availability. Surveys waste heat from 29 major industry groups at the 2-digit level in Standard Industrial Codes (SIC). Explains that waste heat availability in each industry was related to regional product sales, in order to estimate regional waste heat availability. Evaluates 4 selected industries at the 4-digit SIC level. Finds that industrial waste heat represents a significant energy resource in several urban areas, including Chicago and Los Angeles, where it could supply all of these areas residential heating and cooling load. Points out that there is a strong need to evaluate the available waste heat for more industries at the 4-digit level. Urges further studies to identify other useful industrial waste heat sources as well as potential waste heat users

  2. Impact assessment of biomass-based district heating systems in densely populated communities. Part II: Would the replacement of fossil fuels improve ambient air quality and human health?

    Science.gov (United States)

    Petrov, Olga; Bi, Xiaotao; Lau, Anthony

    2017-07-01

    To determine if replacing fossil fuel combustion with biomass gasification would impact air quality, we evaluated the impact of a small-scale biomass gasification plant (BRDF) at a university campus over 5 scenarios. The overall incremental contribution of fine particles (PM2.5) is found to be at least one order of magnitude lower than the provincial air quality objectives. The maximum PM2.5 emission from the natural gas fueled power house (PH) could adversely add to the already high background concentration levels. Nitrogen dioxide (NO2) emissions from the BRDF with no engineered pollution controls for NOx in place exceeded the provincial objective in all seasons except during summer. The impact score, IS, was the highest for NO2 (677 Disability Adjusted Life Years, DALY) when biomass entirely replaced fossil fuels, and the highest for PM2.5 (64 DALY) and CO (3 DALY) if all energy was produced by natural gas at PH. Complete replacement of fossil fuels by one biomass plant can result in almost 28% higher health impacts (708 DALY) compared to 513 DALY when both the current BRDF and the PH are operational mostly due to uncontrolled NO2 emissions. Observations from this study inform academic community, city planners, policy makers and technology developers on the impacts of community district heating systems and possible mitigation strategies: a) community energy demand could be met either by splitting emissions into more than one source at different locations and different fuel types or by a single source with the least-impact-based location selection criteria with biomass as a fuel; b) advanced high-efficiency pollution control devices are essential to lower emissions for emission sources located in a densely populated community; c) a spatial and temporal impact assessment should be performed in developing bioenergy-based district heating systems, in which the capital and operational costs should be balanced with not only the benefit to greenhouse gas emission

  3. Expression profile of human cells in culture exposed to glycidamide, a reactive metabolite of the heat-induced food carcinogen acrylamide

    International Nuclear Information System (INIS)

    Clement, Flurina C.; Dip, Ramiro; Naegeli, Hanspeter

    2007-01-01

    Recent findings of acrylamide in many common foods have sparked renewed interest in assessing human health hazards and the long-term risk associated with exposure to vinyl compounds. Acrylamide is tumorigenic at high doses in rodents and has been classified as a probable human carcinogen. However, cancer risk projections in the population remain problematic because the molecular pathogenesis of acrylamide at the low level of dietary uptake is not understood. In particular, the question of whether specific transcriptional responses may amplify or mitigate the known genotoxicity of acrylamide has never been examined. Here, we used high-density DNA microarrays and PCR validations to assess genome-wide messenger profiles induced by glycidamide, the more reactive metabolite of acrylamide. The expression changes resulting from glycidamide treatment of human epithelial cells are characterized by the induction of detoxification enzymes, several members of the glutathione system and antioxidant factors. Low-dose experiments indicate that the up-regulation of epoxide hydrolase 1 represents the most sensitive transcriptional biomarker of glycidamide exposure. At higher concentrations, glycidamide induces typical markers of tumor progression such as steroid hormone activators, positive regulators of nuclear factor-κB, growth stimulators and apoptosis inhibitors. Concomitantly, growth suppressors and cell adhesion molecules are down-regulated. The main implication of these findings for risk assessment is that low concentrations of glycidamide elicit cytoprotective reactions whereas transcriptional signatures associated with tumor progression may be expected only at doses that exceed the range of ordinary dietary exposures

  4. Suppression of heat shock protein 70 by siRNA enhances the antitumor effects of cisplatin in cultured human osteosarcoma cells.

    Science.gov (United States)

    Mori, Yuki; Terauchi, Ryu; Shirai, Toshiharu; Tsuchida, Shinji; Mizoshiri, Naoki; Arai, Yuji; Kishida, Tsunao; Fujiwara, Hiroyoshi; Mazda, Osam; Kubo, Toshikazu

    2017-09-01

    Although advances in chemotherapy have improved the prognosis for osteosarcoma, some patients do not respond sufficiently to treatment. Heat shock protein 70 (Hsp70) is expressed at high levels in cancer cells and attenuates the therapeutic efficacy of anticancer agents, resulting in a poorer prognosis. This study investigated whether small interfering RNA (siRNA)-mediated inhibition of Hsp70 expression in an osteosarcoma cell line would enhance sensitivity to cisplatin. The expression of Hsp70 with cisplatin treatment was observed by using Western blotting and real-time reverse transcription polymerase chain reaction (RT-PCR). Changes in the IC 50 of cisplatin when Hsp70 was inhibited by siRNA were evaluated. Cisplatin's effectiveness in inducing apoptosis was assessed by assay of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), caspase-3 activity, and mitochondrial membrane potential. Up-regulation of Hsp70 expression was dependent on the concentration of cisplatin. Inhibition of Hsp70 expression significantly reduced the IC 50 of cisplatin. When cisplatin was added to osteosarcoma cells with Hsp70 expression inhibited, a significant increase in apoptosis was demonstrated in TUNEL, caspase-3, and mitochondrial membrane potential assays. Inhibition of Hsp70 expression induced apoptosis in cultured osteosarcoma cells, indicating that Hsp70 inhibition enhanced sensitivity to cisplatin. Inhibition of Hsp70 expression may provide a new adjuvant therapy for osteosarcoma.

  5. Evaluation of a novel noninvasive continuous core temperature measurement system with a zero heat flux sensor using a manikin of the human body.

    Science.gov (United States)

    Brandes, Ivo F; Perl, Thorsten; Bauer, Martin; Bräuer, Anselm

    2015-02-01

    Reliable continuous perioperative core temperature measurement is of major importance. The pulmonary artery catheter is currently the gold standard for measuring core temperature but is invasive and expensive. Using a manikin, we evaluated the new, noninvasive SpotOn™ temperature monitoring system (SOT). With a sensor placed on the lateral forehead, SOT uses zero heat flux technology to noninvasively measure core temperature; and because the forehead is devoid of thermoregulatory arteriovenous shunts, a piece of bone cement served as a model of the frontal bone in this study. Bias, limits of agreements, long-term measurement stability, and the lowest measurable temperature of the device were investigated. Bias and limits of agreement of the temperature data of two SOTs and of the thermistor placed on the manikin's surface were calculated. Measurements obtained from SOTs were similar to thermistor values. The bias and limits of agreement lay within a predefined clinically acceptable range. Repeat measurements differed only slightly, and stayed stable for hours. Because of its temperature range, the SOT cannot be used to monitor temperatures below 28°C. In conclusion, the new SOT could provide a reliable, less invasive and cheaper alternative for measuring perioperative core temperature in routine clinical practice. Further clinical trials are needed to evaluate these results.

  6. Automation of heating system with heat pump

    OpenAIRE

    Ferdin, Gašper

    2016-01-01

    Because of high prices of energy, we are upgrading our heating systems with newer, more fuel efficient heating devices. Each new device has its own control system, which operates independently from other devices in a heating system. With a relatively low investment costs in automation, we can group devices in one central control system and increase the energy efficiency of a heating system. In this project, we show how to connect an oil furnace, a sanitary heat pump, solar panels and a heat p...

  7. Intermittent heating of buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kohonen, K

    1983-02-01

    Conditions for intermittent heating of buildings are considered both theoretically and experimentally. Thermal behaviour of buildings adn rooms in intermittent heating is simulated by a program based on the convective heat balance equation and by simplified RC-models. The preheat times and the heating energy savings compared with continuous heating are presented for typical lightweight, mediumweight and heavyweight classroom and office modules. Formulaes for estimating the oversizing of the radiator network, the maximum heat output of heat exchangers in district heating and the efficiency of heating boilers in intermittent heating are presented. The preheat times and heating energy savings with different heating control systems are determined also experimentally in eight existing buildings. In addition some principles for the planning and application of intermittent heating systems are suggested.

  8. Heat pump technology

    CERN Document Server

    Von Cube, Hans Ludwig; Goodall, E G A

    2013-01-01

    Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

  9. Cryogenic heat transfer

    CERN Document Server

    Barron, Randall F

    2016-01-01

    Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

  10. Future heat supply of our cities. Heating by waste heat

    Energy Technology Data Exchange (ETDEWEB)

    Brachetti, H E [Stadtwerke Hannover A.G. (Germany, F.R.); Technische Univ. Hannover (Germany, F.R.))

    1976-08-01

    The energy-price crisis resulted in structural changes of the complete energy supply and reactivated the question of energy management with respect to the optimum solution of meeting the energy requirements for space heating. Condensation power plants are increasingly replaced by thermal stations, the waste heat of which is used as so-called district heat. Thermal power stations must be situated close to urban areas. The problem of emission of harmful materials can partly be overcome by high-level emission. The main subject of the article, however, is the problem of conducting and distributing the heat. The building costs of heat pipeline systems and the requirements to be met by heat pipelines such as strength, heat insulation and protection against humidity and ground water are investigated.

  11. Heat-Related Illnesses

    Science.gov (United States)

    ... Share this! EmergencyCareForYou » Emergency 101 » Heat-Related Illnesses Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

  12. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Share this! EmergencyCareForYou » Emergency 101 » Heat-Related Illnesses Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

  13. Short-hairpin RNA-mediated Heat shock protein 90 gene silencing inhibits human breast cancer cell growth in vitro and in vivo

    International Nuclear Information System (INIS)

    Zuo, Keqiang; Li, Dan; Pulli, Benjamin; Yu, Fei; Cai, Haidong; Yuan, Xueyu; Zhang, Xiaoping; Lv, Zhongwei

    2012-01-01

    Highlights: ► Hsp90 is over-expressed in human breast cancer. ► The shRNA-mediated gene silencing of Hsp90 resulted in inhibition of cell growth. ► Akt and NF-kB were down-regulation after transfection due to Hsp90 silencing. ► The tumor growth ratio was decline due to Hsp90 silencing. ► The PCNA expression was down-regulation due to Hsp90 silencing. -- Abstract: Hsp90 interacts with proteins that mediate signaling pathways involved in the regulation of essential processes such as proliferation, cell cycle control, angiogenesis and apoptosis. Hsp90 inhibition is therefore an attractive strategy for blocking abnormal pathways that are crucial for cancer cell growth. In the present study, the role of Hsp90 in human breast cancer MCF-7 cells was examined by stably silencing Hsp90 gene expression with an Hsp90-silencing vector (Hsp90-shRNA). RT-PCR and Western blot analyses showed that Hsp90-shRNA specifically and markedly down-regulated Hsp90 mRNA and protein expression. NF-kB and Akt protein levels were down-regulated in Hsp90-shRNA transfected cells, indicating that Hsp90 knockout caused a reduction of survival factors and induced apoptosis. Treatment with Hsp90-shRNA significantly increased apoptotic cell death and caused cell cycle arrest in the G1/S phase in MCF-7 cells, as shown by flow cytometry. Silencing of Hsp90 also reduced cell viability, as determined by MTT assay. In vivo experiments showed that MCF-7 cells stably transfected with Hsp90-shRNA grew slowly in nude mice as compared with control groups. In summary, the Hsp90-shRNA specifically silenced the Hsp90 gene, and inhibited MCF-7 cell growth in vitro and in vivo. Possible molecular mechanisms underlying the effects of Hsp90-shRNA include the degradation of Hsp90 breast cancer-related client proteins, the inhibition of survival signals and the upregulation of apoptotic pathways. shRNA-mediated interference may have potential therapeutic utility in human breast cancer.

  14. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  15. Heat Related Illnesses

    National Research Council Canada - National Science Library

    Carter, R; Cheuvront, S. N; Sawka, M. N

    2006-01-01

    .... The risk of serious heat illness can be markedly reduced by implementing a variety of countermeasures, including becoming acclimated to the heat, managing heat stress exposure, and maintaining hydration...

  16. Heat Roadmap Europe 1

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    2012-01-01

    Heat Roadmap Europe (Pre-study 1) investigates the role of district heating in the EU27 energy system by mapping local conditions across Europe, identifying the potential for district heating expansion, and subsequently simulating the potential resource in an hourly model of the EU27 energy system....... In 2010, approximately 12% of the space heating demand in Europe is met by district heating, but in this study four alternative scenarios are considered for the EU27 energy system: 1. 2010 with 30% district heating 2. 2010 with 50% district heating 3. 2030 with 30% district heating 4. 2050 with 50......% district heating These scenarios are investigated in two steps. Firstly, district heating replaces individual boilers by converting condensing power plants to combined heat and power plants (CHP) to illustrate how district heating improves the overall efficiency of the energy system. In the second step...

  17. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  18. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  19. Heating in toroidal plasmas

    International Nuclear Information System (INIS)

    Knoepfel, H.; Mazzitelli, G.

    1984-01-01

    The article is a rather detailed report on the highlights in the area of the ''Heating in toroidal plasmas'', as derived from the presentations and discussions at the international symposium with the same name, held in Rome, March 1984. The symposium covered both the physics (experiments and theory) and technology of toroidal fusion plasma heating. Both large fusion devices (either already in operation or near completion) requiring auxiliary heating systems at the level of tens of megawatts, as well as physics of their heating processes and their induced side effects (as studied on smaller devices), received attention. Substantial progress was reported on the broad front of auxiliary plasma heating and Ohmic heating. The presentation of the main conclusions of the symposium is divided under the following topics: neutral-beam heating, Alfven wave heating, ion cyclotron heating, lower hybrid heating, RF current drive, electron cyclotron heating, Ohmic heating and special contributions

  20. Development and application of artificial neural network models to estimate values of a complex human thermal comfort index associated with urban heat and cool island patterns using air temperature data from a standard meteorological station.

    Science.gov (United States)

    Moustris, Konstantinos; Tsiros, Ioannis X; Tseliou, Areti; Nastos, Panagiotis

    2018-04-11

    The present study deals with the development and application of artificial neural network models (ANNs) to estimate the values of a complex human thermal comfort-discomfort index associated with urban heat and cool island conditions inside various urban clusters using as only inputs air temperature data from a standard meteorological station. The index used in the study is the Physiologically Equivalent Temperature (PET) index which requires as inputs, among others, air temperature, relative humidity, wind speed, and radiation (short- and long-wave components). For the estimation of PET hourly values, ANN models were developed, appropriately trained, and tested. Model results are compared to values calculated by the PET index based on field monitoring data for various urban clusters (street, square, park, courtyard, and gallery) in the city of Athens (Greece) during an extreme hot weather summer period. For the evaluation of the predictive ability of the developed ANN models, several statistical evaluation indices were applied: the mean bias error, the root mean square error, the index of agreement, the coefficient of determination, the true predictive rate, the false alarm rate, and the Success Index. According to the results, it seems that ANNs present a remarkable ability to estimate hourly PET values within various urban clusters using only hourly values of air temperature. This is very important in cases where the human thermal comfort-discomfort conditions have to be analyzed and the only available parameter is air temperature.

  1. Generation of Adducts of 4-Hydroxy-2-nonenal with Heat Shock 60 kDa Protein 1 in Human Promyelocytic HL-60 and Monocytic THP-1 Cell Lines

    Directory of Open Access Journals (Sweden)

    Alessia Arcaro

    2015-01-01

    Full Text Available Heat shock 60 kDa protein 1 (HSP60 is a chaperone and stress response protein responsible for protein folding and delivery of endogenous peptides to antigen-presenting cells and also a target of autoimmunity implicated in the pathogenesis of atherosclerosis. By two-dimensional electrophoresis and mass spectrometry, we found that exposure of human promyelocytic HL-60 cells to a nontoxic concentration (10 μM of 4-hydroxy-2-nonenal (HNE yielded a HSP60 modified with HNE. We also detected adducts of HNE with putative uncharacterized protein CXorf49, the product of an open reading frame identified in various cell and tissue proteomes. Moreover, exposure of human monocytic THP-1 cells differentiated with phorbol 12-myristate 13-acetate to 10 μM HNE, and to light density lipoprotein modified with HNE (HNE-LDL or by copper-catalyzed oxidation (oxLDL, but not to native LDL, stimulated the formation of HNE adducts with HSP60, as detected by immunoprecipitation and western blot, well over basal levels. The identification of HNE-HSP60 adducts outlines a framework of mutually reinforcing interactions between endothelial cell stressors, like oxLDL and HSP60, whose possible outcomes, such as the amplification of endothelial dysfunction, the spreading of lipoxidative damage to other proteins, such as CXorf49, the activation of antigen-presenting cells, and the breaking of tolerance to HSP60 are discussed.

  2. Development and application of artificial neural network models to estimate values of a complex human thermal comfort index associated with urban heat and cool island patterns using air temperature data from a standard meteorological station

    Science.gov (United States)

    Moustris, Konstantinos; Tsiros, Ioannis X.; Tseliou, Areti; Nastos, Panagiotis

    2018-04-01

    The present study deals with the development and application of artificial neural network models (ANNs) to estimate the values of a complex human thermal comfort-discomfort index associated with urban heat and cool island conditions inside various urban clusters using as only inputs air temperature data from a standard meteorological station. The index used in the study is the Physiologically Equivalent Temperature (PET) index which requires as inputs, among others, air temperature, relative humidity, wind speed, and radiation (short- and long-wave components). For the estimation of PET hourly values, ANN models were developed, appropriately trained, and tested. Model results are compared to values calculated by the PET index based on field monitoring data for various urban clusters (street, square, park, courtyard, and gallery) in the city of Athens (Greece) during an extreme hot weather summer period. For the evaluation of the predictive ability of the developed ANN models, several statistical evaluation indices were applied: the mean bias error, the root mean square error, the index of agreement, the coefficient of determination, the true predictive rate, the false alarm rate, and the Success Index. According to the results, it seems that ANNs present a remarkable ability to estimate hourly PET values within various urban clusters using only hourly values of air temperature. This is very important in cases where the human thermal comfort-discomfort conditions have to be analyzed and the only available parameter is air temperature.

  3. The human VGF-derived bioactive peptide TLQP-21 binds heat shock 71 kDa protein 8 (HSPA8on the surface of SH-SY5Y cells.

    Directory of Open Access Journals (Sweden)

    Shamim Akhter

    Full Text Available VGF (non-acronymicis a secreted chromogranin/secretogranin that gives rise to a number of bioactive peptides by a complex proteolysis mechanism. VGF-derived peptides exert an extensive array of biological effects in energy metabolism, mood regulation, pain, gastric secretion function, reproduction and, perhaps, cancer. It is therefore surprising that very little is known about receptors and binding partners of VGF-derived peptides and their downstream molecular mechanisms of action. Here, using affinity chromatography and mass spectrometry-based protein identification, we have identified the heat shock cognate 71 kDa protein A8 (HSPA8as a binding partner of human TLQP-21 on the surface of human neuroblastomaSH-SY5Y cells. Binding of TLQP-21 to membrane associated HSPA8 in live SH-SY5Y cells was further supported by cross-linking to live cells. Interaction between HSPA8 and TLQP-21 was confirmed in vitro by label-free Dynamic Mass Redistribution (DMR studies. Furthermore, molecular modeling studies show that TLQP-21 can be docked into the HSPA8 peptide binding pocket. Identification of HSPA8 as a cell surface binding partner of TLQP-21 opens new avenues to explore the molecular mechanisms of its physiological actions, and of pharmacological modulation thereof.

  4. Heat shock protein 70 modulates neural progenitor cells dynamics in human neuroblastoma SH-SY5Y cells exposed to high glucose content.

    Science.gov (United States)

    Salimi, Leila; Rahbarghazi, Reza; Jafarian, Vahab; Biray Avci, Çıgır; Goker Bagca, Bakiye; Pinar Ozates, Neslihan; Khaksar, Majid; Nourazarian, Alireza

    2018-01-18

    In the current experiment, detrimental effects of high glucose condition were investigated on human neuroblastoma cells. Human neuroblastoma cell line SH-SY5Y were exposed to 5, 40, and 70 mM glucose over a period of 72 h. Survival rate and the proliferation of cells were analyzed by MTT and BrdU incorporation assays. Apoptosis was studied by the assays of flow cytometry and PCR array. In order to investigate the trans-differentiation capacity of the cell into mature neurons, we used immunofluorescence imaging to follow NeuN protein level. The transcription level of HSP70 was shown by real-time PCR analysis. MMP-2 and -9 activities were shown by gelatin Zymography. According to data from MTT and BrdU incorporation assay, 70 mM glucose reduced cell viability and proliferation rate as compared to control (5 mM glucose) and cells treated with 40 mM glucose (P Cell exposure to 70 mM glucose had potential to induced apoptosis after 72 h (P SH-SY5Y cells to detrimental effects of high glucose condition during trans-differentiation into mature neuron-like cells. Real-time PCR analysis confirmed the expression of HSP70 in cells under high content glucose levels, demonstrating the possible cell compensatory response to an insulting condition (p control vs 70 mM group  cells being exposed to 70 mM glucose. High glucose condition could abrogate the dynamics of neural progenitor cells. The intracellular level of HSP70 was proportional to cell damage in high glucose condition. © 2018 Wiley Periodicals, Inc.

  5. Heat shock protein 90 inhibitor enhances apoptosis by inhibiting the AKT pathway in thermal-stimulated SK-MEL-2 human melanoma cell line.

    Science.gov (United States)

    Shin, Min Kyung; Jeong, Ki-Heon; Choi, Hyeongwon; Ahn, Hye-Jin; Lee, Mu-Hyoung

    2018-02-08

    Heat shock proteins (Hsps) are chaperone proteins, which are upregulated after various stresses. Hsp90 inhibitors have been investigated as adjuvant therapies for the treatment of melanoma. Thermal ablation could be a treatment option for surgically unresectable melanoma or congenital nevomelanocytic nevi, however, there is a limitation such as the possibility of recurrence. We evaluated apoptosis in a melanoma cell line treated with the Hsp90 inhibitor 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), in hyperthermic conditions. SK-MEL-2 cells were stimulated at 43 °C for 1 h and treated with 0, 0.1 and 1 μM 17-DMAG. We evaluated the cell viability using MTT and apoptosis with HSP 90 inhibitor. We studied the protein expression of AKT, phospho-AKT, ERK, phospho-ERK, MAPK, and phospho-MAPK, caspase 3,7,9, and anti-poly (ADP-ribose) polymerase. 17-DMAG significantly inhibited the proliferation of the SK-MEL-2 cells at 37 °C (0.1 μM: 44.47% and 1 μM: 61.23%) and 43 °C (0.1 μM: 49.21% and 1 μM: 63.60%), suggesting synergism between thermal stimulation and 17-DMAG. 17-DMAG treatment increased the frequency of apoptotic cell populations to 2.17% (0.1 μM) and 3.05% (1 μM) in 37 °C controls, and 4.40% (0.1 μM) and 4.97% (1 μM) in the group stimulated at 43 °C. AKT phosphorylation were activated by thermal stimulation and inhibited by 17-DMAG. Hsp90 inhibitor treatment may be clinically applicable to enhance the apoptosis of melanoma cells in hyperthermic condition. Copyright © 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  6. Furan: A critical heat induced dietary contaminant

    DEFF Research Database (Denmark)

    Mariotti, María S.; Granby, Kit; Rozowski, Jaime

    2013-01-01

    The presence of furan in a broad range of heat processed foods (0-6000 μg kg-1) has received considerable attention due to the fact that this heat induced contaminant is considered as a "possible carcinogenic compound to humans". Since a genotoxic mode of action could be associated with furan...... of some critical factors such as heating conditions, pH and matrix microstructure are discussed in order to propose some potential methodologies for furan mitigation in a wide range of heated foods. © 2013 The Royal Society of Chemistry....

  7. Regenerative adsorbent heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  8. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    David, Andrei; Mathiesen, Brian Vad; Averfalk, Helge

    2017-01-01

    The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25–30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document that suc......The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25–30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document...

  9. Heat pumps in district heating networks

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    constraints limit the power plants. Efficient heat pumps can be used to decouple the constraints of electricity and heat production, while maintaining the high energy efficiency needed to match the politically agreed carbon emission goals. The requirements in terms of COP, location, capacity and economy...... and strategic planning in the energy sector. The paper presents a case study of optimal implementation of heat pumps in the present energy system of the Copenhagen area. By introduction of the correct capacity of heat pumps, a 1,6 % reduction in fuel consumption for electricity and heat production can...

  10. Novel Mechanism of Attenuation of LPS-Induced NF-κB Activation by the Heat Shock Protein 90 Inhibitor, 17-N-allylamino-17-demethoxygeldanamycin, in Human Lung Microvascular Endothelial Cells

    Science.gov (United States)

    Thangjam, Gagan S.; Dimitropoulou, Chistiana; Joshi, Atul D.; Barabutis, Nektarios; Shaw, Mary C.; Kovalenkov, Yevgeniy; Wallace, Chistopher M.; Fulton, David J.; Patel, Vijay

    2014-01-01

    Heat shock protein (hsp) 90 inhibition attenuates NF-κB activation and blocks inflammation. However, the precise mechanism of NF-κB regulation by hsp90 in the endothelium is not clear. We investigated the mechanisms of hsp90 inhibition by 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) on NF-κB activation by LPS in primary human lung microvascular endothelial cells. Transcriptional activation of NF-κB was measured by luciferase reporter assay, gene expression by real-time RT-PCR, DNA binding of transcription factors by chromatin immunoprecipitation assay, protein–protein interaction by coimmunoprecipitation/immunoblotting, histone deacetylase (HDAC)/histone acetyltransferase enzyme activity by fluorometry, and nucleosome eviction by partial microccocal DNase digestion. In human lung microvascular endothelial cells, 17-AAG–induced degradation of IKBα was accomplished regardless of the phosphorylation/ubiquitination state of the protein. Hence, 17-AAG did not block LPS-induced NF-κB nuclear translocation and DNA binding activity. Instead, 17-AAG blocked the recruitment of the coactivator, cAMP response element binding protein binding protein, and prevented the assembly of a transcriptionally competent RNA polymerase II complex at the κB elements of the IKBα (an NF-κB–responsive gene) promoter. The effect of LPS on IKBα mRNA expression was associated with rapid deacetylation of histone-H3(Lys9) and a dramatic down-regulation of core histone H3 binding. Even though treatment with an HDAC inhibitor produced the same effect as hsp90 inhibition, the effect of 17-AAG was independent of HDAC. We conclude that hsp90 inhibition attenuates NF-κB transcriptional activation by preventing coactivator recruitment and nucleosome eviction from the target promoter in human lung endothelial cells. PMID:24303801

  11. Dynamics of the association of heat shock protein HSPA6 (Hsp70B') and HSPA1A (Hsp70-1) with stress-sensitive cytoplasmic and nuclear structures in differentiated human neuronal cells.

    Science.gov (United States)

    Shorbagi, Sadek; Brown, Ian R

    2016-11-01

    Heat shock proteins (Hsps) are cellular repair agents that counter the effects of protein misfolding that is a characteristic feature of neurodegenerative diseases. HSPA1A (Hsp70-1) is a widely studied member of the HSPA (Hsp70) family. The little-studied HSPA6 (Hsp70B') is present in the human genome and absent in mouse and rat; hence, it is missing in current animal models of neurodegenerative diseases. Differentiated human neuronal SH-SY5Y cells were employed to compare the dynamics of the association of YFP-tagged HSPA6 and HSPA1A with stress-sensitive cytoplasmic and nuclear structures. Following thermal stress, live-imaging confocal microscopy and Fluorescence Recovery After Photobleaching (FRAP) demonstrated that HSPA6 displayed a prolonged and more dynamic association, compared to HSPA1A, with centrioles that play critical roles in neuronal polarity and migration. HSPA6 and HSPA1A also targeted nuclear speckles, rich in RNA splicing factors, and the granular component of the nucleolus that is involved in rRNA processing and ribosomal subunit assembly. HSPA6 and HSPA1A displayed similar FRAP kinetics in their interaction with nuclear speckles and the nucleolus. Subsequently, during the recovery from neuronal stress, HSPA6, but not HSPA1A, localized with the periphery of nuclear speckles (perispeckles) that have been characterized as transcription sites. The stress-induced association of HSPA6 with perispeckles displayed the greatest dynamism compared to the interaction of HSPA6 or HSPA1A with other stress-sensitive cytoplasmic and nuclear structures. This suggests involvement of HSPA6 in transcriptional recovery of human neurons from cellular stress that is not apparent for HSPA1A.

  12. Solar heat storages in district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Ellehauge, K. (Ellehauge og Kildemoes, AArhus (DK)); Engberg Pedersen, T. (COWI A/S, Kgs. Lyngby (DK))

    2007-07-15

    This report gives information on the work carried out and the results obtained in Denmark on storages for large solar heating plants in district heating networks. Especially in Denmark the share of district heating has increased to a large percentage. In 1981 around 33% of all dwellings in DK were connected to a district heating network, while the percentage in 2006 was about 60% (in total 1.5 mio. dwellings). In the report storage types for short term storage and long term storages are described. Short term storages are done as steel tanks and is well established technology widely used in district heating networks. Long term storages are experimental and used in connection with solar heating. A number of solar heating plants have been established with either short term or long term storages showing economy competitive with normal energy sources. Since, in the majority of the Danish district heating networks the heat is produced in co-generation plants, i.e. plants producing both electricity and heat for the network, special attention has been put on the use of solar energy in combination with co-generation. Part of this report describes that in the liberalized electricity market central solar heating plants can also be advantageous in combination with co-generation plants. (au)

  13. Heat pipes for ground heating and cooling

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, L L

    1988-01-01

    Different versions of heat pipe ground heating and cooling devices are considered. Solar energy, biomass, ground stored energy, recovered heat of industrial enterprises and ambient cold air are used as energy and cold sources. Heat pipe utilization of air in winter makes it possible to design accumulators of cold and ensures deep freezing of ground in order to increase its mechanical strength when building roadways through the swamps and ponds in Siberia. Long-term underground heat storage systems are considered, in which the solar and biomass energy is accumulated and then transferred to heat dwellings and greenhouses, as well as to remove snow from roadways with the help of heat pipes and solar collectors.

  14. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Connolly, David; Lund, Henrik; Mathiesen, Brian Vad

    2014-01-01

    compared to 1990 levels. None of these scenarios involve the large-scale implementation of district heating, but instead they focus on the electrification of the heating sector (primarily using heat pumps) and/or the large-scale implementation of electricity and heat savings. In this paper, the potential...... for district heating in the EU between now and 2050 is identified, based on extensive and detailed mapping of the EU heat demand and various supply options. Subsequently, a new ‘district heating plus heat savings’ scenario is technically and economically assessed from an energy systems perspective. The results...... indicate that with district heating, the EU energy system will be able to achieve the same reductions in primary energy supply and carbon dioxide emissions as the existing alternatives proposed. However, with district heating these goals can be achieved at a lower cost, with heating and cooling costs...

  15. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Hansen, Kenneth; Connolly, David; Lund, Henrik

    2015-01-01

    The cost of heat savings in buildings increase as more heat savings are achieved due to the state of the building stock and hence, alternatives other than savings typically become more economically feasible at a certain level of heat reductions. It is important to identify when the cost of heat...... savings become more expensive than the cost of sustainable heat supply, so society does not overinvest in heat saving measures. This study first investigates the heat saving potentials for different countries in Europe, along with their associated costs, followed by a comparison with alternative ways...... of supplying sustainable heating. Different heat production options are included in terms of individual and community heating systems. Furthermore, the levelised cost of supplying sustainable heat is estimated for both a single technology and from an energy system perspective. The results are analysed...

  16. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Lund, Henrik

    2015-01-01

    This document is a summary of the key technical inputs for the modelling of the heat strategy for Europe outlined in the latest Heat Roadmap Europe studies [1, 2]. These studies quantify the impact of alternative heating strategies for Europe in 2030 and 2050. The study is based on geographical...... information systems (GIS) and energy system analyses. In this report, the inputs for other modelling tools such as PRIMES are presented, in order to enable other researches to generate similar heating scenarios for Europe. Although Heat Roadmap Europe presents a complete heat strategy for Europe, which...... includes energy efficiency, individual heating units (such as boilers and heat pumps), and heat networks, the recommendations here are primarily relating to the potential and modelling of district heating. Although other solutions will play a significant role in decarbonising the heating and cooling sector...

  17. Heat stress-induced loss of eukaryotic initiation factor 5A (eIF-5A) in a human pancreatic cancer cell line, MIA PaCa-2, analyzed by two-dimensional gel electrophoresis.

    Science.gov (United States)

    Takeuchi, Kana; Nakamura, Kazuyuki; Fujimoto, Masanori; Kaino, Seiji; Kondoh, Satoshi; Okita, Kiwamu

    2002-02-01

    Alterations of intracellular proteins during the process of heat stress-induced cell death of a human pancreatic cancer cell line, MIA PaCa-2, were investigated using two-dimensional gel electrophoresis (2-DE), agarose gel electrophoresis, and cell biology techniques. Incubation of MIA PaCa-2 at 45 degrees C for 30 min decreased the cell growth rate and cell viability without causing chromosomal DNA fragmentation. Incubation at 51 degrees C for 30 min suppressed cell growth and again led to death without DNA fragmentation. The cell death was associated with the loss of an intracellular protein of M(r) 17,500 and pI 5.2 on 2-DE gel. This protein was determined to be eukaryotic initiation factor SA (eIF-5A) by microsequencing of the N-terminal region of peptide fragments obtained by cyanogen bromide treatment of the protein blotted onto a polyvinylidene difluoride (PVDF) membrane. The sequences detected were QXSALRKNGFVVLKGRP and STSKTGXHGHAKVHLVGID, which were homologous with the sequence of eIF-5A from Gln 20 to Pro 36 and from Ser 43 to Asp 61, respectively. Furthermore, the result of sequencing suggested that the protein was an active form of hypusinated eIF-5A, because Lys 46 could be detected but not Lys 49, which is the site for hypusination. These results suggest that loss of the active form of eIF-5A is an important factor in the irreversible process of heat stress-induced death of MIA PaCa-2 cells.

  18. It Ain't the Heat, It's the Humanity: Evidence and Implications of a Knowledge-Based Consensus on Man-Made Global Warming

    Science.gov (United States)

    Jacobs, P.; Cook, J.; Nuccitelli, D. A.

    2013-12-01

    One of the most worrisome misconceptions among the general public about climate change is a belief that scientists disagree not only about the cause of the present climate change, but also whether or not the planet is currently warming. Recent surveys have demonstrated that an overwhelming consensus exists, both within the scientific literature and among scientists with climate expertise, that the planet is warming and humans are driving this climatic change. This disconnect, or 'consensus gap', between scientific agreement and public belief has significant consequences for public understanding of the reality and cause of climate change, as well as support for potential solutions. Ensuring that the consensus message is not simply broadcast but is also accepted as legitimate by the public appears to be a primary education and communications opportunity. While the existence of a consensus is not itself evidence of a position's truth, according to Miller (2013) scientific consensus can be taken as evidence that a position is true if it is 'knowledge-based', satisfying the conditions of social calibration, apparent consilience of evidence, and social diversity. We demonstrate that the scientific consensus on anthropogenic climate change is knowledge-based, satisfying Miller's criteria. In so doing, we hope to increase confidence in its use as an education and communications tool, and assure the public of its validity. We show the consensus is socially calibrated, based on common evidential standards, ontological schemes, and shared formalism. We establish that consilience of evidence points overwhelmingly to the reality of anthropogenic climate change by examining the evidence from several perspectives. We identify unique fingerprints expected as a result of increased greenhouse forcing, eliminate potential natural drivers of climate change as the cause of the present change, and demonstrate the consistency of the observed climate response with known changes in natural

  19. Rotary magnetic heat pump

    Science.gov (United States)

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  20. Transient Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of transient heat conduction.Fourier's law. General heat conducation equation. Thermal diffusivity. Biot and Fourier numbers. Lumped analysis and time constant. Semi-infinite body: fixed surface temperature, convective heat transfer at the surface, or constant surface heat flux...

  1. Thermometry, calorimetry, and mean body temperature during heat stress.

    Science.gov (United States)

    Kenny, Glen P; Jay, Ollie

    2013-10-01

    Heat balance in humans is maintained at near constant levels through the adjustment of physiological mechanisms that attain a balance between the heat produced within the body and the heat lost to the environment. Heat balance is easily disturbed during changes in metabolic heat production due to physical activity and/or exposure to a warmer environment. Under such conditions, elevations of skin blood flow and sweating occur via a hypothalamic negative feedback loop to maintain an enhanced rate of dry and evaporative heat loss. Body heat storage and changes in core temperature are a direct result of a thermal imbalance between the rate of heat production and the rate of total heat dissipation to the surrounding environment. The derivation of the change in body heat content is of fundamental importance to the physiologist assessing the exposure of the human body to environmental conditions that result in thermal imbalance. It is generally accepted that the concurrent measurement of the total heat generated by the body and the total heat dissipated to the ambient environment is the most accurate means whereby the change in body heat content can be attained. However, in the absence of calorimetric methods, thermometry is often used to estimate the change in body heat content. This review examines heat exchange during challenges to heat balance associated with progressive elevations in environmental heat load and metabolic rate during exercise. Further, we evaluate the physiological responses associated with heat stress and discuss the thermal and nonthermal influences on the body's ability to dissipate heat from a heat balance perspective.

  2. Application of heat pump by using the earth temperature gradient for winter heating and summer cooling

    International Nuclear Information System (INIS)

    Gacevski, Marijan; Tanev, Pepi

    2003-01-01

    Because of the rapid technique development as well as modern human life, in order to satisfy the energy needs it is necessary to use a new apparatus and devices. In this manner, the electric power consumption, especially for heating and cooling, rapidly increases. One of the possible ways to reduce the consumption of electric energy for heating and cooling is that, to use heat pumps. In this paper a heat pump that uses the heat of the earth by a horizontal polyethylene pipe heat exchanger is proposed. Also, all parameters are examined and comparison with already existing ones is done. The heat gradient of the earth in spite of saving electrical energy is analyzed as well. (Original)

  3. Thulium-170 heat source

    Science.gov (United States)

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  4. District heating in Switzerland

    International Nuclear Information System (INIS)

    Herzog, F.

    1991-01-01

    District heating has been used in Switzerland for more than 50 years. Its share of the heat market is less than 3% today. An analysis of the use of district heating in various European countries shows that a high share of district heating in the heat market is always dependent on ideal conditions for its use. Market prospects and possible future developments in the use of district heating in Switzerland are described in this paper. The main Swiss producers and distributors of district heating are members of the Association of District Heating Producers and Distributors. This association supports the installation of district heating facilities where ecological, energetical and economic aspects indicate that district heating would be a good solution. (author) 2 tabs., 6 refs

  5. Future Heat Waves In Asia

    Science.gov (United States)

    Eltahir, E. A. B.

    2017-12-01

    I will review recent work from my group on the impact of climate change on the intensity and frequency of heat waves in Asia. Our studies covered Southwest Asia, South Asia, East China, and the Maritime continent. In any of these regions, the risk associated with climate change impact reflects intensity of natural hazard and level of human vulnerability. Previous work has shown that the wet-bulb temperature is a useful variable to consider in describing the natural hazard from heat waves since it can be easily compared to the natural threshold that defines the upper limit on human survivability. Based on an ensemble of high resolution climate change simulations, we project extremes of wet-bulb temperature conditions in each of these four regions of Asia. We consider the business-as-usual scenario of future greenhouse gas emissions, as well as a moderate mitigation scenario. The results from these regions will be compared and lessons learned summarized.

  6. Analysis of Heat Transfer

    International Nuclear Information System (INIS)

    2003-08-01

    This book deals with analysis of heat transfer which includes nonlinear analysis examples, radiation heat transfer, analysis of heat transfer in ANSYS, verification of analysis result, analysis of heat transfer of transition with automatic time stepping and open control, analysis of heat transfer using arrangement of ANSYS, resistance of thermal contact, coupled field analysis such as of thermal-structural interaction, cases of coupled field analysis, and phase change.

  7. Heating in toroidal plasmas

    International Nuclear Information System (INIS)

    Canobbio, E.

    1981-01-01

    This paper reports on the 2nd Joint Grenoble-Varenna International Symposium on Heating in Toroidal Plasmas, held at Como, Italy, from the 3-12 September 1980. Important problems in relation to the different existing processes of heating. The plasma were identified and discussed. Among others, the main processes discussed were: a) neutral beam heating, b) ion-(electron)-cyclotron resonance heating, c) hybrid resonance and low frequency heating

  8. Introduction to heat transfer

    CERN Document Server

    SUNDÉN, B

    2012-01-01

    Presenting the basic mechanisms for transfer of heat, Introduction to Heat Transfer gives a deeper and more comprehensive view than existing titles on the subject. Derivation and presentation of analytical and empirical methods are provided for calculation of heat transfer rates and temperature fields as well as pressure drop. The book covers thermal conduction, forced and natural laminar and turbulent convective heat transfer, thermal radiation including participating media, condensation, evaporation and heat exchangers.

  9. Heat exchange apparatus

    International Nuclear Information System (INIS)

    Thurston, G.C.; McDaniels, J.D.; Gertsch, P.R.

    1979-01-01

    The present invention relates to heat exchangers used for transferring heat from the gas cooled core of a nuclear reactor to a secondary medium during standby and emergency conditions. The construction of the heat exchanger described is such that there is a minimum of welds exposed to the reactor coolant, the parasitic heat loss during normal operation of the reactor is minimized and the welds and heat transfer tubes are easily inspectable. (UK)

  10. Heat cascading regenerative sorption heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  11. Heat transfer from internally heated hemispherical pools

    International Nuclear Information System (INIS)

    Gabor, J.D.; Ellsion, P.G.; Cassulo, J.C.

    1980-01-01

    Experiments were conducted on heat transfer from internally heated ZnSO 4 -H 2 O pools to the walls of hemispherical containers. This experimental technique provides data for a heat transfer system that has to date been only theoretically treated. Three different sizes of copper hemispherical containers were used: 240, 280, 320 mm in diameter. The pool container served both as a heat transfer surface and as an electrode. The opposing electrode was a copper disk, 50 mm in diameter located at the top of the pool in the center. The top surface of the pool was open to the atmosphere

  12. Humid Heat Waves at different warming levels

    Science.gov (United States)

    Russo, S.; Sillmann, J.; Sterl, A.

    2017-12-01

    The co-occurrence of consecutive hot and humid days during a heat wave can strongly affect human health. Here, we quantify humid heat wave hazard in the recent past and at different levels of global warming.We find that the magnitude and apparent temperature peak of heat waves, such as the ones observed in Chicago in 1995 and China in 2003, have been strongly amplified by humidity. Climate model projections suggest that the percentage of area where heat wave magnitude and peak are amplified by humidity increases with increasing warming levels. Considering the effect of humidity at 1.5o and 2o global warming, highly populated regions, such as the Eastern US and China, could experience heat waves with magnitude greater than the one in Russia in 2010 (the most severe of the present era).The apparent temperature peak during such humid-heat waves can be greater than 55o. According to the US Weather Service, at this temperature humans are very likely to suffer from heat strokes. Humid-heat waves with these conditions were never exceeded in the present climate, but are expected to occur every other year at 4o global warming. This calls for respective adaptation measures in some key regions of the world along with international climate change mitigation efforts.

  13. The potent activation of Ca(2+)-activated K(+) current by NVP-AUY922 in the human pancreatic duct cell line (PANC-1) possibly independent of heat shock protein 90 inhibition.

    Science.gov (United States)

    Chiang, Nai-Jung; Wu, Sheng-Nan; Chen, Li-Tzong

    2015-04-01

    NVP-AUY922 (AUY) is a potent inhibitor of heat shock protein 90 (HSP90). Whether this compound can exert additional effects on membrane ion channels remains elusive. We investigated the effect of AUY on ion currents in human pancreatic duct epithelial cells (PDECs), including PANC-1 and MIA PaCa-2. AUY increased the amplitude of the K(+) current (IK) in PANC-1 cells shown by whole-cell configuration. Single-channel recordings revealed a large-conductance Ca(2+)-activated K(+) (BKCa) channel in PANC-1, but not in MIA PaCa-2. In cell-attached mode, AUY increased the probability of BKCa channel opening and also potentiated the activity of stretch-induced channels. However, other HSP inhibitors, 17-AAG or BIIB021 only slightly increased the activity of BKCa channels. In inside-out recordings, sodium hydrosulphide or caffeic acid phenethyl ester increased the activity of BKCa channels, but AUY did not. We further evaluated whether conductance of Ca(2+)-activated K(+) channels (IK(Ca)) influenced secretion of HCO3(-) and fluid in PDECs by using a modified Whitcomb-Ermentrout model. Simulation studies showed that an increase in IK(Ca) resulted in additional secretion of HCO3(-) and fluid by mimicking the effect of AUY in PDECs. Collectively, AUY can interact with the BKCa channel to largely increase IK(Ca) in PDECs. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  14. Heat pump augmentation of nuclear process heat

    International Nuclear Information System (INIS)

    Koutz, S.L.

    1986-01-01

    A system is described for increasing the temperature of a working fluid heated by a nuclear reactor. The system consists of: a high temperature gas cooled nuclear reactor having a core and a primary cooling loop through which a coolant is circulated so as to undergo an increase in temperature, a closed secondary loop having a working fluid therein, the cooling and secondary loops having cooperative association with an intermediate heat exchanger adapted to effect transfer of heat from the coolant to the working fluid as the working fluid passes through the intermediate heat exchanger, a heat pump connected in the secondary loop and including a turbine and a compressor through which the working fluid passes so that the working fluid undergoes an increase in temperature as it passes through the compressor, a process loop including a process chamber adapted to receive a process fluid therein, the process chamber being connected in circuit with the secondary loop so as to receive the working fluid from the compressor and transfer heat from the working fluid to the process fluid, a heat exchanger for heating the working fluid connected to the process loop for receiving heat therefrom and for transferring heat to the secondary loop prior to the working fluid passing through the compressor, the secondary loop being operative to pass the working fluid from the process chamber to the turbine so as to effect driving relation thereof, a steam generator operatively associated with the secondary loop so as to receive the working fluid from the turbine, and a steam loop having a feedwater supply and connected in circuit with the steam generator so that feedwater passing through the steam loop is heated by the steam generator, the steam loop being connected in circuit with the process chamber and adapted to pass steam to the process chamber with the process fluid

  15. Heat recovery in industry

    Energy Technology Data Exchange (ETDEWEB)

    Steimle, F; Paul, J [Essen Univ. (Gesamthochschule) (Germany, F.R.)

    1977-05-01

    The waste heat of industrial furnaces and other heat-consuming installations can be utilized by recuperative processes in the furnace and by energy cascades. Economy and the need for an external supply of energy are closely connected. Straight cascades can hardly be realized and if the required temperature gradient is too great such heat should be utilized repeatedly if possible by recycling through heat pumps. The possibilities depend on the relevant temperature since the technology available for this differs in its state of development. The low-temperature waste heat from the final stage can be used for space-heating and water heating by heat exchangers and heat pumps and thus be put to a useful purpose.

  16. New nuclear heat sources for district heating

    International Nuclear Information System (INIS)

    Lerouge, B.

    1975-01-01

    The means by which urban oil heating may be taken over by new energy sources, especially nuclear, are discussed. Several possibilities exist: pressurized water reactors for high powers, and low-temperature swimming-pool-type process-heat reactors for lower powers. Both these cases are discussed [fr

  17. Heat transfer system

    Science.gov (United States)

    Not Available

    1980-03-07

    A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

  18. Basic heat transfer

    CERN Document Server

    Bacon, D H

    2013-01-01

    Basic Heat Transfer aims to help readers use a computer to solve heat transfer problems and to promote greater understanding by changing data values and observing the effects, which are necessary in design and optimization calculations.The book is concerned with applications including insulation and heating in buildings and pipes, temperature distributions in solids for steady state and transient conditions, the determination of surface heat transfer coefficients for convection in various situations, radiation heat transfer in grey body problems, the use of finned surfaces, and simple heat exc

  19. Microscale Regenerative Heat Exchanger

    Science.gov (United States)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2006-01-01

    The device described herein is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.

  20. Heat transfer enhancement

    International Nuclear Information System (INIS)

    Hasatani, Masanobu; Itaya, Yoshinori

    1985-01-01

    In order to develop energy-saving techniques and new energy techniques, and also most advanced techniques by making industrial equipment with high performance, heat transfer performance frequently becomes an important problem. In addition, the improvement of conventional heat transfer techniques and the device of new heat transfer techniques are often required. It is most proper that chemical engineers engage in the research and development for enhancing heat transfer. The research and development for enhancing heat transfer are important to heighten heat exchange efficiency or to cool equipment for preventing overheat in high temperature heat transfer system. In this paper, the techniques of enhancing radiative heat transfer and the improvement of radiative heat transfer characteristics are reported. Radiative heat transfer is proportional to fourth power of absolute temperature, and it does not require any heat transfer medium, but efficient heat-radiation converters are necessary. As the techniques of enhancing radiative heat transfer, the increase of emission and absorption areas, the installation of emissive structures and the improvement of radiative characteristics are discussed. (Kako, I.)

  1. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  2. The secure heating reactor

    International Nuclear Information System (INIS)

    Pind, C.

    1987-01-01

    The SECURE heating reactor was designed by ASEA-ATOM as a realistic alternative for district heating in urban areas and for supplying heat to process industries. SECURE has unique safety characteristics, that are based on fundamental laws of physics. The safety does not depend on active components or operator intervention for shutdown and cooling of the reactor. The inherent safety characteristics of the plant cannot be affected by operator errors. Due to its very low environment impact, it can be sited close to heat consumers. The SECURE heating reactor has been shown to be competitive in comparison with other alternatives for heating Helsinki and Seoul. The SECURE heating reactor forms a basis for the power-producing SECURE-P reactor known as PIUS (Process Inherent Ultimate Safety), which is based on the same inherent safety principles. The thermohydraulic function and transient response have been demonstrated in a large electrically heated loop at the ASEA-ATOM laboratories

  3. Effective geothermal heat

    International Nuclear Information System (INIS)

    Abelsen, Atle

    2006-01-01

    Scandinavia's currently largest geothermal heating project: the New Ahus hospital, is briefly presented. 300-400 wells on a field outside the hospital are constructed to store energy for both heating and cooling purposes

  4. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Be Prepared Safe Citizen Day Organize Important Medical Information ER Checklists Preparing for Emergencies Be ready to ... anyone can be affected. Here you will find information about heat cramps and heat stroke and exhaustion. ...

  5. Paleoclassical electron heat transport

    International Nuclear Information System (INIS)

    Callen, J.D.

    2005-01-01

    Radial electron heat transport in low collisionality, magnetically-confined toroidal plasmas is shown to result from paleoclassical Coulomb collision processes (parallel electron heat conduction and magnetic field diffusion). In such plasmas the electron temperature equilibrates along magnetic field lines a long length L, which is the minimum of the electron collision length and a maximum effective half length of helical field lines. Thus, the diffusing field lines induce a radial electron heat diffusivity M ≅ L/(πR 0q ) ∼ 10 >> 1 times the magnetic field diffusivity η/μ 0 ≅ ν e (c/ω p ) 2 . The paleoclassical electron heat flux model provides interpretations for many features of 'anomalous' electron heat transport: magnitude and radial profile of electron heat diffusivity (in tokamaks, STs, and RFPs), Alcator scaling in high density plasmas, transport barriers around low order rational surfaces and near a separatrix, and a natural heat pinch (or minimum temperature gradient) heat flux form. (author)

  6. Regenerative heat sources for heating networks

    International Nuclear Information System (INIS)

    Huenges, Ernst; Sperber, Evelyn; Eggers, Jan-Bleicke; Noll, Florian; Kallert, Anna Maria; Reuss, Manfred

    2015-01-01

    The ambitious goal, the German Federal Government has set itself, to reduce the emissions of greenhouse gases by 80% to 95% by the year 2050. As there are currently more than half of German energy consumption for the production of heat is required, big contributions to climate protection can be expected from this area if more renewable heat sources are used. Renewable heat sources such as bioenergy, solar thermal and geothermal energy in particular can be provided as compared to fossil fuels with significantly lower specific CO 2 emissions. Objectives in the heating market and scenarios for the transformation of the heat sector have been elaborated in the BMU Lead Study 2011. The main pillar of this scenario is the reduction of final energy consumption for heat by the energy-efficient renovation of existing buildings and further increasing demands on the energetic quality of new buildings. To cover the remaining energy demand, a focus is on the expansion of heating networks based on renewable energies. [de

  7. Ion cyclotron resonance heating

    International Nuclear Information System (INIS)

    Tajima, T.

    1982-01-01

    Ion cyclotron resonance heating of plasmas in tokamak and EBT configurations has been studied using 1-2/2 and 2-1/2 dimensional fully self-consistent electromagnetic particle codes. We have tested two major antenna configurations; we have also compared heating efficiencies for one and two ion species plasmas. We model a tokamak plasma with a uniform poloidal field and 1/R toroidal field on a particular q surface. Ion cyclotron waves are excited on the low field side by antennas parallel either to the poloidal direction or to the toroidal direction with different phase velocities. In 2D, minority ion heating (vsub(perpendicular)) and electron heating (vsub(parallel),vsub(perpendicular)) are observed. The exponential electron heating seems due to the decay instability. The minority heating is consistent with mode conversion of fast Alfven waves and heating by electrostatic ion cyclotron modes. Minority heating is stronger with a poloidal antenna. The strong electron heating is accompanied by toroidal current generation. In 1D, no thermal instability was observed and only strong minority heating resulted. For an EBT plasma we model it by a multiple mirror. We have tested heating efficiency with various minority concentrations, temperatures, mirror ratios, and phase velocities. In this geometry we have beach or inverse beach heating associated with the mode conversion layer perpendicular to the toroidal field. No appreciable electron heating is observed. Heating of ions is linear in time. For both tokamak and EBT slight majority heating above the collisional rate is observed due to the second harmonic heating. (author)

  8. The urban heat island dynamics during heat waves: a study of cities in the United States

    Science.gov (United States)

    Hu, Leiqiu

    2016-04-01

    The urban heat island (UHI) is a common phenomenon describing that metropolitan areas are usually warmer than their rural surroundings. This effect is compounded by extreme heat events, which are a leading cause of weather-related human mortality in many countries worldwide. However, the spatial and diurnal variability of temperature and humidity in urban and adjacent rural areas during extreme heat events is not well measured and therefore not well understood. The recently developed dataset of near-surface air and dew temperature from MODIS atmospheric profiles and the new method for the UHI quantification--urban heat island curve are used to quantify the urban climatic changes during heat waves in cities of the United States. The enhanced and weakened UHIs are observed in various cities. The causes of UHI changes during heat waves are discussed, including climate region, vegetation type and amount, city geolocation, etc.

  9. Heat roadmap China

    DEFF Research Database (Denmark)

    Xiong, Weiming; Wang, Yu; Mathiesen, Brian Vad

    2015-01-01

    District heating is regarded as a key element of energy saving actions in the Chinese national energy strategy, while space heating in China is currently still dominated by coal boilers. However, there is no existing quantitative study to analyse the future heat strategy for China. Therefore...

  10. Heat Recovery System

    Science.gov (United States)

    1984-01-01

    Ball Metal's design of ducting and controls for series of roof top heat exchangers was inspired by Tech Briefs. Heat exchangers are installed on eight press and coating lines used to decorate sheet metal. The heat recovery system provides an estimated energy savings of more than $250,000 per year.

  11. Microwave processing heats up

    Science.gov (United States)

    Microwaves are a common appliance in many households. In the United States microwave heating is the third most popular domestic heating method food foods. Microwave heating is also a commercial food processing technology that has been applied for cooking, drying, and tempering foods. It's use in ...

  12. Solar heating pipe

    Energy Technology Data Exchange (ETDEWEB)

    Hinson-Rider, G.

    1977-10-04

    A fluid carrying pipe is described having an integral transparent portion formed into a longitudinally extending cylindrical lens that focuses solar heat rays to a focal axis within the volume of the pipe. The pipe on the side opposite the lens has a heat ray absorbent coating for absorbing heat from light rays that pass through the focal axis.

  13. Champagne Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  14. Designing heat exchangers for process heat reactors

    International Nuclear Information System (INIS)

    Quade, R.N.

    1980-01-01

    A brief account is given of the IAEA specialist meeting on process heat applications technology held in Julich, November 1979. The main emphasis was on high temperature heat exchange. Papers were presented covering design requirements, design construction and prefabrication testing, and selected problems. Primary discussion centered around mechanical design, materials requirements, and structural analysis methods and limits. It appears that high temperature heat exchanges design to nuclear standards, is under extensive development but will require a lengthy concerted effort before becoming a commercial reality. (author)

  15. Condensation heat transfer in plate heat exchangers

    International Nuclear Information System (INIS)

    Panchal, C.B.

    1985-01-01

    An Alfa-Laval plate heat exchanger, previously tested as an evaporator, was retested as a condenser. Two series of tests with different chevron-angle plates were carried out using ammonia as a working fluid. The overall heat-transfer coefficient and pressure drop were measured, and the effects of operating parameters were determined. The experimental data were compared with theoretical predictions. In the analysis, a gravity-controlled condensation process was modeled theoretically, and the overall performance was calculated. The analysis shows that the overall heat-transfer coefficient can be predicted with an average uncertainty of about 10%. It is, however, important to consider the interfacial shear stress, because the effective friction factor is high for flow in plate heat exchangers

  16. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Broers, G. H. J.

    1977-01-01

    The heat evolution at a single irreversibly working electrode is treated onthe basis of the Brønsted heat principle. The resulting equation is analogous to the expression for the total heat evolution in a galvanic cellwith the exception that –DeltaS is substituted by the Peltier entropy, Delta......SP, of theelectrode reaction. eta is the overvoltage at the electrode. This equation is appliedto a high temperature carbonate fuel cell. It is shown that the Peltier entropyterm by far exceeds the heat production due to the irreversible losses, and thatthe main part of heat evolved at the cathode is reabsorbed...

  17. Introduction to heat transfer

    International Nuclear Information System (INIS)

    Weisman, J.

    1983-01-01

    Heat may be defined as that form of energy which spontaneously flows between two bodies, or two regions of a body, by virtue of a temperature difference. The second law of thermodynamics tells us that we cannot have heat flow from a low temperature to high temperature without doing work. Heat flows spontaneously from a high temperature to a low temperature region. Thermodynamics, which is concerned with equilibrium states, cannot tell us anything about the rate of heat flow in the presence of a finite temperature difference. It is to the discipline of heat transfer to which we must turn for this answer

  18. Interactions between urban heat islands and heat waves

    Science.gov (United States)

    Zhao, Lei; Oppenheimer, Michael; Zhu, Qing; Baldwin, Jane W.; Ebi, Kristie L.; Bou-Zeid, Elie; Guan, Kaiyu; Liu, Xu

    2018-03-01

    Heat waves (HWs) are among the most damaging climate extremes to human society. Climate models consistently project that HW frequency, severity, and duration will increase markedly over this century. For urban residents, the urban heat island (UHI) effect further exacerbates the heat stress resulting from HWs. Here we use a climate model to investigate the interactions between the UHI and HWs in 50 cities in the United States under current climate and future warming scenarios. We examine UHI2m (defined as urban-rural difference in 2m-height air temperature) and UHIs (defined as urban-rural difference in radiative surface temperature). Our results show significant sensitivity of the interaction between UHI and HWs to local background climate and warming scenarios. Sensitivity also differs between daytime and nighttime. During daytime, cities in the temperate climate region show significant synergistic effects between UHI and HWs in current climate, with an average of 0.4 K higher UHI2m or 2.8 K higher UHIs during HWs than during normal days. These synergistic effects, however, diminish in future warmer climates. In contrast, the daytime synergistic effects for cities in dry regions are insignificant in the current climate, but emerge in future climates. At night, the synergistic effects are similar across climate regions in the current climate, and are stronger in future climate scenarios. We use a biophysical factorization method to disentangle the mechanisms behind the interactions between UHI and HWs that explain the spatial-temporal patterns of the interactions. Results show that the difference in the increase of urban versus rural evaporation and enhanced anthropogenic heat emissions (air conditioning energy use) during HWs are key contributors to the synergistic effects during daytime. The contrast in water availability between urban and rural land plays an important role in determining the contribution of evaporation. At night, the enhanced release of stored

  19. Heat Roadmap Europe 2

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strate......Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible....... In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials...... are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050...

  20. Nuclear process heat

    International Nuclear Information System (INIS)

    Barnert, H.; Hohn, H.; Schad, M.; Schwarz, D.; Singh, J.

    1993-01-01

    In a system for the application of high temperature heat from the HTR one must distinguish between the current generation and the use of process heat. In this respect it is important that the current can be generated by dual purpose power plants. The process heat is used as sensible heat, vaporisation heat and as chemical energy at the chemical conversion for the conversion of raw materials, the refinement of fossil primary energy carriers and finally circuit processes for the fission of water. These processes supply the market for heat, fuels, motor fuels and basic materials. Fifteen examples of HTR heat processes from various projects and programmes are presented in form of energy balances, however in a rather short way. (orig./DG) [de

  1. Space Heating Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin D.

    1998-01-01

    The performance evaluation of space heating equipment for a geothermal application is generally considered from either of two perspectives: (a) selecting equipment for installation in new construction, or (b) evaluating the performance and retrofit requirements of an existing system. With regard to new construction, the procedure is relatively straightforward. Once the heating requirements are determined, the process need only involve the selection of appropriately sized hot water heating equipment based on the available water temperature. It is important to remember that space heating equipment for geothermal applications is the same equipment used in non-geothermal applications. What makes geothermal applications unique is that the equipment is generally applied at temperatures and flow rates that depart significantly from traditional heating system design. This chapter presents general considerations for the performance of heating equipment at non-standard temperature and flow conditions, retrofit of existing systems, and aspects of domestic hot water heating.

  2. FTR europia gamma heating

    International Nuclear Information System (INIS)

    Ward, J.T. Jr.

    1975-01-01

    Calculated and experimental gamma heating rates of europia in the Engineering Mockup Critical Assembly (EMC) were correlated. A calculated to experimental (C/E) ratio of 1.086 was established in validating the theoretical approach and computational technique applied in the calculations. Gamma heat deposition rates in the FTR with Eu 2 O 3 control absorbers were determined from three-dimensional calculations. Maximum gamma heating was found to occur near the tip of a half-inserted row 5 control rod assembly--12.8 watts/gm of europia. Gamma heating profiles were established for a single half-inserted europia absorber assembly. Local heat peaking was found not to alter significantly heating rates computed in the FTR core model, where larger mesh interval sizes precluded examination of spatially-limited heating gradients. These computations provide the basis for thermal-hydraulic analyses to ascertain temperature profiles in the FTR under europia control

  3. Miniature Heat Pipes

    Science.gov (United States)

    1997-01-01

    Small Business Innovation Research contracts from Goddard Space Flight Center to Thermacore Inc. have fostered the company work on devices tagged "heat pipes" for space application. To control the extreme temperature ranges in space, heat pipes are important to spacecraft. The problem was to maintain an 8-watt central processing unit (CPU) at less than 90 C in a notebook computer using no power, with very little space available and without using forced convection. Thermacore's answer was in the design of a powder metal wick that transfers CPU heat from a tightly confined spot to an area near available air flow. The heat pipe technology permits a notebook computer to be operated in any position without loss of performance. Miniature heat pipe technology has successfully been applied, such as in Pentium Processor notebook computers. The company expects its heat pipes to accommodate desktop computers as well. Cellular phones, camcorders, and other hand-held electronics are forsible applications for heat pipes.

  4. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Connolly, David

    2017-01-01

    This paper compares the electricity, heating, and cooling sectors at national level for various European countries. Annual energy demands are compared for all 28 EU countries, while peak hourly demands are compared for four countries that vary significantly. The results indicate that the heat...... demand is currently the largest of the three demand types considered in terms of both annual and peak demands: it is the largest annual demand in 25 of the 28 EU countries, and it represents the largest peak demand in all four countries analysed. Electricity, heating, and cooling demands are all likely...... that the demand for electricity could double compared to today, depending on how these changes occur. Considering the scale of additional electricity required to electrify future heating and cooling demands, heat pumps should be prioritised over electric heating and other alternatives, such as district heating...

  5. District heating versus local heating - Social supportability

    International Nuclear Information System (INIS)

    Matei, Magdalena; Enescu, Diana; Varjoghie, Elena; Radu, Florin; Matei, Lucian

    2004-01-01

    District heating, DH, is an energy source which can provide a cost-effective, environmentally friendly source of heat and power for cities, but only in the case of well running systems, with reasonable technological losses. The benefits of DH system are well known: environmental friendly, energy security, economic and social advantages. DH already covers 60% of heating and hot water needs in transition economies. Today, 70 % of Russian, Latvian and Belarus homes use DH, and heating accounts for one-third of total Russian energy consumption. Yet a large number of DH systems in the region face serious financial, marketing or technical problems because of the policy framework. How can DH issues be best addressed in national and local policy? What can governments do to create the right conditions for the sustainable development of DH while improving service quality? What policies can help capture the economic, environmental and energy security benefits of co-generation and DH? To address these questions, the International Energy Agency (IEA) hosted in 2002 and 2004 conference focusing on the crucial importance of well-designed DH policies, for exchanging information on policy approaches. The conclusions of the conference have shown that 'DH systems can do much to save energy and boost energy security, but stronger policy measures are needed to encourage wise management and investment. With a stronger policy framework, DH systems in formerly socialist countries could save the equivalent of 80 billion cubic meters of natural gas a year through supply side efficiency improvements. This is greater than total annual natural gas consumption in Italy'. More efficient systems will also decrease costs, reducing household bills and making DH competitive on long-term. This paper presents the issues: -Theoretical benefits of the district heating and cooling systems; - Municipal heating in Romania; - Technical and economic problems of DH systems and social supportability; - How

  6. 24 CFR 3280.506 - Heat loss/heat gain.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Heat loss/heat gain. 3280.506... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat loss/heat gain shall be determined by methods outlined in...

  7. Comparison of LCA results of low temperature heat plant using electric heat pump, absorption heat pump and gas-fired boiler

    International Nuclear Information System (INIS)

    Nitkiewicz, Anna; Sekret, Robert

    2014-01-01

    Highlights: • Usage of geothermal heat pump can bring environmental benefits. • The lowest environmental impact for whole life cycle is obtained for absorption heat pump. • The value of heat pump COP has a significant influence on environmental impact. • In case of coal based power generation the damage to human health is significant. - Abstract: This study compares the life cycle impacts of three heating plant systems which differ in their source of energy and the type of system. The following heating systems are considered: electric water-water heat pump, absorption water-water heat pump and natural gas fired boiler. The heat source for heat pump systems is low temperature geothermal source with temperature below 20 °C and spontaneous outflow 24 m 3 /h. It is assumed that the heat pumps and boiler are working in monovalent system. The analysis was carried out for heat networks temperature characteristic at 50/40 °C which is changing with outdoor temperature during heating season. The environmental life cycle impact is evaluated within life cycle assessment methodological framework. The method used for life cycle assessment is eco-indicator ‘99. The functional unit is defined as heating plant system with given amount of heat to be delivered to meet local heat demand in assumed average season. The data describing heating plant system is derived from literature and energy analysis of these systems. The data describing the preceding life cycle phases: extraction of raw materials and fuels, production of heating devices and their transportation is taken from Ecoinvent 2.0 life cycle inventory database. The results were analyzed on three levels of indicators: single score indicator, damage category indicators and impact category indicator. The indicators were calculated for characterization, normalization and weighting phases as well. SimaPro 7.3.2 is the software used to model the systems’ life cycle. The study shows that heating plants using a low

  8. Optimization of Heat Exchangers

    International Nuclear Information System (INIS)

    Catton, Ivan

    2010-01-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics (pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger design.

  9. Floor heating maximizes residents` comfort

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkanen, P.; Wikstroem, T.

    1996-11-01

    Storing heat in floors by using economical night-time electricity does not increase the specific consumption of heating. According to studies done by IVO, the optimum housing comfort is achieved if the room is heated mainly by means of floor heating that is evened out by window or ceiling heating, or by a combination of all three forms of heating. (orig.)

  10. Lab-scale experiment of a closed thermochemical heat storage system including honeycomb heat exchanger

    International Nuclear Information System (INIS)

    Fopah-Lele, Armand; Rohde, Christian; Neumann, Karsten; Tietjen, Theo; Rönnebeck, Thomas; N'Tsoukpoe, Kokouvi Edem; Osterland, Thomas; Opel, Oliver

    2016-01-01

    A lab-scale thermochemical heat storage reactor was developed in the European project “thermal battery” to obtain information on the characteristics of a closed heat storage system, based on thermochemical reactions. The present type of storage is capable of re-using waste heat from cogeneration system to produce useful heat for space heating. The storage material used was SrBr 2 ·6H 2 O. Due to agglomeration or gel-like problems, a structural element was introduced to enhance vapour and heat transfer. Honeycomb heat exchanger was designed and tested. 13 dehydration-hydration cycles were studied under low-temperature conditions (material temperatures < 100 °C) for storage. Discharging was realized at water vapour pressure of about 42 mbar. Temperature evolution inside the reactor at different times and positions, chemical conversion, thermal power and overall efficiency were analysed for the selected cycles. Experimental system thermal capacity and efficiency of 65 kWh and 0.77 are respectively obtained with about 1 kg of SrBr 2 ·6H 2 O. Heat transfer fluid recovers heat at a short span of about 43 °C with an average of 22 °C during about 4 h, acceptable temperature for the human comfort (20 °C on day and 16 °C at night). System performances were obtained for a salt bed energy density of 213 kWh·m 3 . The overall heat transfer coefficient of the honeycomb heat exchanger has an average value of 147 W m −2  K −1 . Though promising results have been obtained, ameliorations need to be made, in order to make the closed thermochemical heat storage system competitive for space heating. - Highlights: • Lab-scale thermochemical heat storage is designed, constructed and tested. • The use of honeycomb heat exchanger as a heat and vapour process enhancement. • Closed system (1 kg SrBr 2 ·6H 2 O) able to give back 3/4 of initial thermal waste energy. • System storage capacity and thermal efficiency are respectively 65 kWh and 0.77.

  11. District heating and heat storage using the solution heat of an ammonia/water system

    International Nuclear Information System (INIS)

    Taube, M.; Peier, W.; Mayor, J.C.

    1976-01-01

    The article describes a model for the optimum use of the heat energy generated in a nuclear power station for district heating and heat storage taking account of the electricity and heat demand varying with time. (HR/AK) [de

  12. Necessity for usage of geothermal heat pump

    International Nuclear Information System (INIS)

    Dimitrov, Konstantin; Armenski, Slave; Gacevski, Marijan

    2004-01-01

    Every day we are witnesses of constantly rapid increase of consumption of Electric energy in R. of Macedonia as so as in the other countries in all the world. This rapid increase of consumption of Electric energy independent of a lot of electrical units, which are applying in human life like: homes, administration and publication objects, as well as in industry. All of this conditions make us to thinking how is possible more rational consumption of electric energy in all areas in human life. One of the possible manners to reduce the consumption of electrical energy for heating and cooling is to use geothermal heat pumps. In this paper will be proposed geothermal heat pump, which is going to use the heat of earth by vertical and horizontal cupper pipe heat exchanger with data from-GHP (Geothermal Heat Pump) NORDIC, factory in Canada. Also, it will be examined all parameters and done comparison with already existing ones. It is analyzed comparison of GHP with other energy units and what it means for rational consumption of electric energy, economic saving and ecology saving. (Author)

  13. Heat-pipe Earth.

    Science.gov (United States)

    Moore, William B; Webb, A Alexander G

    2013-09-26

    The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics.

  14. Heat pipe development

    Science.gov (United States)

    Bienart, W. B.

    1973-01-01

    The objective of this program was to investigate analytically and experimentally the performance of heat pipes with composite wicks--specifically, those having pedestal arteries and screwthread circumferential grooves. An analytical model was developed to describe the effects of screwthreads and screen secondary wicks on the transport capability of the artery. The model describes the hydrodynamics of the circumferential flow in triangular grooves with azimuthally varying capillary menisci and liquid cross-sections. Normalized results were obtained which give the influence of evaporator heat flux on the axial heat transport capability of the arterial wick. In order to evaluate the priming behavior of composite wicks under actual load conditions, an 'inverted' glass heat pipe was designed and constructed. The results obtained from the analysis and from the tests with the glass heat pipe were applied to the OAO-C Level 5 heat pipe, and an improved correlation between predicted and measured evaporator and transport performance were obtained.

  15. The heat spells of Mexico City

    Directory of Open Access Journals (Sweden)

    Ernesto Jáuregui

    2010-06-01

    Full Text Available The warning of urban air has been documented to increase in intensity and area as cities grow (Oke, 1982. As the cities grow the so called “heat island” tends to increase the risk of more frequent heat waves as well as their impacts (IPCC, 2001. Threshold values to define a heat wave vary geographically. For the case of Mexico City located in a high inland valley in the tropics, values above 30° C (daily maximum observed for three or more consecutive days and 25° C or more as mean temperature have been adopted to define the phenomenon. These events occur at the end of the dry season during March to May when afternoon relative humidity is quite low (∼20% and thus reducing the stress. Maximum temperatute data from the Observatory of the National Meteorological Service were used. Results show that during the second half of the XXth century the frequency of heat waves as defined above has doubled from 6 events/decade to 16/decade in the 1990s with a marked increase in the last third of the last century when population of the city grew from 8.5 to 18.5 million (CONAPO, 2000. During this time the average urban/rural contrast grew considerably from about 6° C to 10° C (Jáuregui, 1986. While these heat waves may be considered as “mild”they receive attention from the media and prompt actions by the population to relieve the heat stress. Application of heat indices based on the human energy balance (PET and PMV result in moderate to strong heat stress during these events. Because climate change is expected to raise nighttime minimum temperatures more than daytime highs (as suggested by the IPCC, 2001 urban heat islands and their related heat waves are likely to be a significant health concern in days to come in large urban centers especially in the developing countries.

  16. District heating in Italy

    International Nuclear Information System (INIS)

    Sacchi, E.

    1998-01-01

    The legislative act establishing the electric monopoly virtually shut out the district heating associated with electricity cogeneration, while other laws, issued to counteract the effects of oil shocks, allowed municipal utilities to do so. Thus, district heating has experienced some development, though well below its possibilities. The article analyses the reasons for this lagging, reports district heating data and projects its forecasts against the Kyoto Protocol objectives [it

  17. Convection heat transfer

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    Written by an internationally recognized authority on heat transfer and thermodynamics, this second edition of Convection Heat Transfer contains new and updated problems and examples reflecting real-world research and applications, including heat exchanger design. Teaching not only structure but also technique, the book begins with the simplest problem solving method (scale analysis), and moves on to progressively more advanced and exact methods (integral method, self similarity, asymptotic behavior). A solutions manual is available for all problems and exercises.

  18. Resorption heat pump

    International Nuclear Information System (INIS)

    Vasiliev, L.L.; Mishkinis, D.A.; Antukh, A.A.; Kulakov, A.G.; Vasiliev, L.L.

    2004-01-01

    Resorption processes are based on at least two solid-sorption reactors application. The most favorable situation for the resorption heat pumps is the case, when the presence of a liquid phase is impossible. From simple case--two reactors with two salts to complicated system with two salts + active carbon fiber (fabric) and two branch of the heat pump acting out of phase to produce heat and cold simultaneously, this is the topic of this research program

  19. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-01

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possibly IBW-generated sheared flows

  20. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2003-01-01

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows

  1. Heat transfer II essentials

    CERN Document Server

    REA, The Editors of

    1988-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Heat Transfer II reviews correlations for forced convection, free convection, heat exchangers, radiation heat transfer, and boiling and condensation.

  2. Heat and thermodynamics

    CERN Document Server

    Saxena, A K

    2014-01-01

    Heat and thermodynamics aims to serve as a textbook for Physics, Chemistry and Engineering students. The book covers basic ideas of Heat and Thermodynamics, Kinetic Theory and Transport Phenomena, Real Gases, Liquafaction and Production and Measurement of very Low Temperatures, The First Law of Thermodynamics, The Second and Third Laws of Thermodynamics and Heat Engines and Black Body Radiation. KEY FEATURES Emphasis on concepts Contains 145 illustrations (drawings), 9 Tables and 48 solved examples At the end of chapter exercises and objective questions

  3. Advances in heat transfer

    CERN Document Server

    Hartnett, James P; Cho, Young I; Greene, George A

    2001-01-01

    Heat transfer is the exchange of heat energy between a system and its surrounding environment, which results from a temperature difference and takes place by means of a process of thermal conduction, mechanical convection, or electromagnetic radiation. Advances in Heat Transfer is designed to fill the information gap between regularly scheduled journals and university-level textbooks by providing in-depth review articles over a broader scope than is allowable in either journals or texts.

  4. New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

    A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

  5. Introduction to Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. NCTS 21070-15. Course Description: This course will present operating principles of the heat pipe with emphases on the underlying physical processes and requirements of pressure and energy balance. Performance characterizations and design considerations of the heat pipe will be highlighted. Guidelines for thermal engineers in the selection of heat pipes as part of the spacecraft thermal control system, testing methodology, and analytical modeling will also be discussed.

  6. Isotope heating block

    International Nuclear Information System (INIS)

    Wenk, E.

    1976-01-01

    A suggestion is made not to lead the separated nuclear 'waste' from spent nuclear fuel elements directly to end storage, but to make use of the heat produced from the remaining radiation, e.g. for seawater desalination. According to the invention, the activated fission products are to be processed, e.g. by calcination or vitrification, so that one can handle them. They should then be arranged in layers alternately with plate-shaped heat conducting pipes to form a homogeneous block; the heat absorbed by the thermal plates should be further passed on to evaporators or heat exchangers. (UWI) [de

  7. Heated Tube Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Heated Tube Facility at NASA GRC investigates cooling issues by simulating conditions characteristic of rocket engine thrust chambers and high speed airbreathing...

  8. Heat Capacity Analysis Report

    International Nuclear Information System (INIS)

    Findikakis, A.

    2004-01-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  9. 2-component heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, W

    1987-03-01

    The knowledge accumulated only recently of the damage to buildings and the hazards of formaldehyde, radon and hydrocarbons has been inducing louder calls for ventilation, which, on their part, account for the fact that increasing importance is being attached to the controlled ventilation of buildings. Two-component heating systems provide for fresh air and thermal comfort in one. While the first component uses fresh air blown directly and controllably into the rooms, the second component is similar to the Roman hypocaustic heating systems, meaning that heated outer air is circulating under the floor, thus providing for hot surfaces and thermal comfort. Details concerning the two-component heating system are presented along with systems diagrams, diagrams of the heating system and tables identifying the respective costs. Descriptions are given of the two systems components, the fast heat-up, the two-component made, the change of air, heat recovery and control systems. Comparative evaluations determine the differences between two-component heating systems and other heating systems. Conclusive remarks are dedicated to energy conservation and comparative evaluations of costs. (HWJ).

  10. Automatic heating control system

    Energy Technology Data Exchange (ETDEWEB)

    Whittle, A.J.

    1989-11-15

    A heating control system for buildings comprises at least one heater incorporating heat storage means, a first sensor for detecting temperature within the building, means for setting a demand temperature, a second sensor for detecting outside temperature, a timer, and means for determining the switch on time of the heat storage means on the basis of the demand temperature and the internal and external temperatures. The system may additionally base the switch on time of the storage heater(s) on the heating and cooling rates of the building (as determined from the sensed temperatures); or on the anticipated daytime temperature (determined from the sensed night time temperature). (author).

  11. Lunar Base Heat Pump

    Science.gov (United States)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  12. Heat-induced alterations in the cell nucleus

    International Nuclear Information System (INIS)

    Kampinga, H.H.

    1989-01-01

    Hyperthermia may kill eukaryotic cells and may also enhance the radiosensitivity of those cells that survive the heat treatment. Clinically, the possible use of hyperthermia as an adjuvant in the radiotherapeutic treatment of cancer needs the understanding of mechanisms that underlay heat-induced cell death and radiosensitization. By in vitro heating of established human (HeLaS3) and rodent (Ehrlich Ascites Tumor and LM fibroblast) cell lines, both killing and radiosensitization were investigated. (author). 1067 refs.; 76 figs.; 19 tabs

  13. Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

  14. Utilising heat from nuclear waste for space heating

    International Nuclear Information System (INIS)

    Deacon, D.

    1982-01-01

    A heating unit utilising the decay heat from irradiated material comprises a storage envelope for the material associated with a heat exchange system, means for producing a flow of air over the heat exchange system to extract heat from the material, an exhaust duct capable of discharging the heated air to the atmosphere, and means for selectively diverting at least some of the heated air to effect the required heating. With the flow of air over the heat exchange system taking place by a natural thermosyphon process the arrangement is self regulating and inherently reliable. (author)

  15. Radioisotopic heat source

    Science.gov (United States)

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  16. Heat insulation support device

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Koda, Tomokazu; Motojima, Osamu; Yamamoto, Junya.

    1994-01-01

    The device of the present invention comprises a plurality of heat insulation legs disposed in a circumferential direction. Each of the heat insulative support legs has a hollow shape, and comprises an outer column and an inner column as support structures having a heat insulative property (heat insulative structure), and a thermal anchor which absorbs compulsory displacement by a thin flat plate (displacement absorber). The outer column, the thermal anchor and the inner column are connected by a support so as to offset the positional change of objects to be supported due to shrinkage when they are shrunk. In addition, the portion between the superconductive coils as the objects to be supported and the inner column is connected by the support. The superconductive thermonuclear device is entirely contained in a heat insulative vacuum vessel, and the heat insulative support legs are disposed on a lower lid of the heat insulative vacuum vessel. With such a constitution, they are strengthened against lateral load and buckling, thereby enabling to reduce the amount of heat intrusion while keeping the compulsory displacement easy to be absorbed. (I.N.)

  17. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  18. Heat pipes and use of heat pipes in furnace exhaust

    Science.gov (United States)

    Polcyn, Adam D.

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  19. Experimental investigation of a manifold heat-pipe heat exchanger

    International Nuclear Information System (INIS)

    Konev, S.V.; Wang Tszin' Lyan'; D'yakov, I.I.

    1995-01-01

    Results of experimental investigations of a heat exchanger on a manifold water heat pipe are given. An analysis is made of the temperature distribution along the heat-transfer agent path as a function of the transferred heat power. The influence of the degree of filling with the heat transfer agent on the operating characteristics of the construction is considered

  20. Heat stress and strain in exercise and sport.

    Science.gov (United States)

    Brotherhood, John R

    2008-01-01

    Heat stress arising from the thermal environment is of concern to sports medicine and to sports administration because of the perceived risk of heat casualties, in particular heat stroke. Many sports organizations recommend environmental indices such as the WBGT for assessing risk and setting environmental limits for training and competition. But the limits are not justified by evidence. This article describes the nature of heat stress in sport and how it may be assessed objectively. Heat stress and the principal human responses to exercise heat stress are reviewed briefly. Metabolic heat production and the thermal environment provoke separate and largely independent physiological strains. Metabolic heat production drives body core temperature, and the thermal environment drives skin temperature; the combined stresses are integrated to drive sweat rate. Control of core temperature depends on adequate sweat production and the capacity of the environment to evaporate the sweat. The nature of exercise heat stress is demonstrated by rational analysis of the physical heat exchanges between the body and the environment. The principles of this analysis are applied to critical review of current practice in the assessment of heat stress in sport. The article concludes with discussion of research to establish methods for objective sport-specific assessment of heat stress.

  1. Industrial excess heat for district heating in Denmark

    International Nuclear Information System (INIS)

    Bühler, Fabian; Petrović, Stefan; Karlsson, Kenneth; Elmegaard, Brian

    2017-01-01

    Highlights: •Method for utilisation potential of industrial excess heat for district heating. •Industrial excess heat from thermal processes is quantified at single production units. •Linking of industrial excess heat sources and district heating demands done in GIS. •Excess heat recovery using direct heat transfer and heat pumps. •5.1% of the Danish district heating demand could be supplied by industrial excess heat. -- Abstract: Excess heat is available from various sources and its utilisation could reduce the primary energy use. The accessibility of this heat is however dependent amongst others on the source and sink temperature, amount and potential users in its vicinity. In this work a new method is developed which analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal processes which equals 5.1% of the current demand. More than half of this heat was found to be usable directly, without the need for a heat pump.

  2. Gas fired heat pumps

    International Nuclear Information System (INIS)

    Seifert, M.

    2006-01-01

    The condensing gas boiler is now state of the art and there is no more room for improvement in performance, technically speaking. The next logical step to improve the overall efficiency is to exploit ambient heat in combination with the primary source of energy, natural gas. That means using natural-gas driven heat pumps and gas-fired heat pumps. Based on this, the Swiss Gas Industry decided to set up a practical test programme enjoying a high priority. The aim of the project 'Gas-fired heat pump practical test' is to assess by field tests the characteristics and performance of the foreign serial heat pumps currently on the market and to prepare and promote the introduction on the market place of this sustainable natural-gas technology. (author)

  3. Graphene heat dissipating structure

    Science.gov (United States)

    Washburn, Cody M.; Lambert, Timothy N.; Wheeler, David R.; Rodenbeck, Christopher T.; Railkar, Tarak A.

    2017-08-01

    Various technologies presented herein relate to forming one or more heat dissipating structures (e.g., heat spreaders and/or heat sinks) on a substrate, wherein the substrate forms part of an electronic component. The heat dissipating structures are formed from graphene, with advantage being taken of the high thermal conductivity of graphene. The graphene (e.g., in flake form) is attached to a diazonium molecule, and further, the diazonium molecule is utilized to attach the graphene to material forming the substrate. A surface of the substrate is treated to comprise oxide-containing regions and also oxide-free regions having underlying silicon exposed. The diazonium molecule attaches to the oxide-free regions, wherein the diazonium molecule bonds (e.g., covalently) to the exposed silicon. Attachment of the diazonium plus graphene molecule is optionally repeated to enable formation of a heat dissipating structure of a required height.

  4. Solar heating system

    Science.gov (United States)

    Schreyer, James M.; Dorsey, George F.

    1982-01-01

    An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

  5. Mesoscopic photon heat transistor

    DEFF Research Database (Denmark)

    Ojanen, T.; Jauho, Antti-Pekka

    2008-01-01

    We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir-Wingreen-Landauer-typ......We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir......-Wingreen-Landauer-type of conductance formula, which gives the photonic heat current through an arbitrary circuit element coupled to two dissipative reservoirs at finite temperatures. As an illustration we present an exact solution for the case when the intermediate circuit can be described as an electromagnetic resonator. We discuss...

  6. Heat flux microsensor measurements

    Science.gov (United States)

    Terrell, J. P.; Hager, J. M.; Onishi, S.; Diller, T. E.

    1992-01-01

    A thin-film heat flux sensor has been fabricated on a stainless steel substrate. The thermocouple elements of the heat flux sensor were nickel and nichrome, and the temperature resistance sensor was platinum. The completed heat flux microsensor was calibrated at the AEDC radiation facility. The gage output was linear with heat flux with no apparent temperature effect on sensitivity. The gage was used for heat flux measurements at the NASA Langley Vitiated Air Test Facility. Vitiated air was expanded to Mach 3.0 and hydrogen fuel was injected. Measurements were made on the wall of a diverging duct downstream of the injector during all stages of the hydrogen combustion tests. Because the wall and the gage were not actively cooled, the wall temperature reached over 1000 C (1900 F) during the most severe test.

  7. Improved solar heating systems

    Science.gov (United States)

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  8. Heat tolerance in wheat

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari

    As a consequence of global climate change, heat stress together with other abiotic stresses will remain an important determinant of future food security. Wheat (Triticum aestivum L.) is the third most important crop of the world feeding one third of the world population. Being a crop of temperate...... climate, wheat is sensitive to heat stress. We need to understand how our crops will perform in these changing climatic conditions and how we can develop varieties, which are more tolerant. The PhD study focussed on understanding heat tolerance in wheat with a combined approach of plant physiology...... and quantitative genetics in particular, plant phenotyping based quantitative trait loci (QTL) discovery for a physiological trait under heat stress. Chlorophyll a fluorescence trait, Fv/Fm was used as a phenotyping tool, as it reflects the effect of heat stress on maximum photochemical efficiency of photosystem...

  9. Heat strain in protective clothing - challenges and intervention strategies

    NARCIS (Netherlands)

    McLellan, T.M.; Daanen, H.A.M.; Kiekens, P.; Jayaraman, S.

    2012-01-01

    Humans rely on sweat evaporation during exercise in the heat to promote cooling and to maintain thermal homeostasis. In protective clothing, however, sweat evaporation is severely hampered and this may lead to uncompensable heat strain, where core body temperature continues to rise leading to

  10. Heat strain in personal protective clothing: Challenges and intervention strategies

    NARCIS (Netherlands)

    McLellan, T.M.; Daanen, H.A.M.

    2012-01-01

    Humans rely on sweat evaporation during exercise in the heat to promote cooling and to maintain thermal homeostasis. In protective clothing, however, sweat evaporation is severely hampered and this may lead to uncompensable heat strain, where core body temperature continues to rise leading to

  11. HUMAN COMFORT AND THE MICROCLIMATIC DRIVERS ...

    African Journals Online (AJOL)

    Osondu

    mean heat stress (poor human comfort), followed by high density residential areas. A major attribute ... Key words: Heat stress, human comfort, microclimate, land use, urban, vegetation. Introduction ... defined by the meteorological Glossary as the physical state of .... which is the focus of the study is characterized by. Human ...

  12. Human Powered Centrifuge

    Science.gov (United States)

    Mulenburg, Gerald M. (Inventor); Vernikos, Joan (Inventor)

    1997-01-01

    A human powered centrifuge has independently established turntable angular velocity and human power input. A control system allows excess input power to be stored as electric energy in a battery or dissipated as heat through a resistors. In a mechanical embodiment, the excess power is dissipated in a friction brake.

  13. Industrial excess heat for district heating in Denmark

    DEFF Research Database (Denmark)

    Bühler, Fabian; Petrovic, Stefan; Karlsson, Kenneth Bernard

    2017-01-01

    analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate...... the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity...... analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal...

  14. Acoustically enhanced heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: tan.ming.kwang@monash.edu [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)

    2016-01-15

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  15. Chapter 11. Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin D.; Culver, Gene

    1998-01-01

    Most geothermal fluids, because of their elevated temperature, contain a variety of dissolved chemicals. These chemicals are frequently corrosive toward standard materials of construction. As a result, it is advisable in most cases to isolate the geothermal fluid from the process to which heat is being transferred. The task of heat transfer from the geothermal fluid to a closed process loop is most often handled by a plate heat exchanger. The two most common types used in geothermal applications are: bolted and brazed. For smaller systems, in geothermal resource areas of a specific character, downhole heat exchangers (DHEs) provide a unique means of heat extraction. These devices eliminate the requirement for physical removal of fluid from the well. For this reason, DHE-based systems avoid entirely the environmental and practical problems associated with fluid disposal. Shell and tube heat exchangers play only a minor role in low-temperature, direct-use systems. These units have been in common use in industrial applications for many years and, as a result, are well understood. For these reasons, shell and tube heat exchangers will not be covered in this chapter.

  16. Heat pipe dynamic behavior

    Science.gov (United States)

    Issacci, F.; Roche, G. L.; Klein, D. B.; Catton, I.

    1988-01-01

    The vapor flow in a heat pipe was mathematically modeled and the equations governing the transient behavior of the core were solved numerically. The modeled vapor flow is transient, axisymmetric (or two-dimensional) compressible viscous flow in a closed chamber. The two methods of solution are described. The more promising method failed (a mixed Galerkin finite difference method) whereas a more common finite difference method was successful. Preliminary results are presented showing that multi-dimensional flows need to be treated. A model of the liquid phase of a high temperature heat pipe was developed. The model is intended to be coupled to a vapor phase model for the complete solution of the heat pipe problem. The mathematical equations are formulated consistent with physical processes while allowing a computationally efficient solution. The model simulates time dependent characteristics of concern to the liquid phase including input phase change, output heat fluxes, liquid temperatures, container temperatures, liquid velocities, and liquid pressure. Preliminary results were obtained for two heat pipe startup cases. The heat pipe studied used lithium as the working fluid and an annular wick configuration. Recommendations for implementation based on the results obtained are presented. Experimental studies were initiated using a rectangular heat pipe. Both twin beam laser holography and laser Doppler anemometry were investigated. Preliminary experiments were completed and results are reported.

  17. Heat recovery apparatus

    International Nuclear Information System (INIS)

    McFarland, I.

    1987-01-01

    Heat transfer is a living science and technical advances are constantly being made. However, in many cases, progress is limited by the equipment that is available on the market, rather than by knowledge of the heat transfer process. A case in point is the design of economizers: in such equipment a small quantity of water (with a relatively good heat transfer coefficient) is heated by a large quantity of low-pressure gas (with an inherently low heat transfer coefficient). As a first step in design finned tubing is used to lessen the discrepancy in coefficients. From this point, it becomes apparent that the equipment consists of a small number of tubes (to maintain good velocity on the water side) of considerable length (to provide sufficient area). In the process industries the base pressure, though low, may be in the region of 0.5 bar, and there is no convenient flue in which to place the heat recovery coil. It is therefore contained in a flat-sided enclosure, which is ill-fitted to pressure containment and is therefore reinforced with a plethora of structural sections. Such inelegant construction is quite common in North America; in Europe, cylindrical containments of vast size have been supplied for the same purposes. The real shortcoming is a successful marriage of different disciplines to produce reliable and efficient heat transfer equipment suitably contained

  18. Fluidised bed heat exchangers

    International Nuclear Information System (INIS)

    Elliott, D.E.; Healey, E.M.; Roberts, A.G.

    1974-01-01

    Problems that have arisen during the initial stages of development of fluidised bed boilers in which heat transfer surfaces are immersed in fluidised solids are discussed. The very high heat transfer coefficients that are obtained under these conditions can be exploited to reduce the total heat transfer surface to a fraction of that in normal boilers. However, with the high heat flux levels involved, tube stressing becomes more important and it is advantageous to use smaller diameter tubes. One of the initial problems was that the pumping power absorbed by the fluidised bed appeared to be high. The relative influence of the fluidising velocity (and the corresponding bed area), tube diameter, tube spacing, heat transfer coefficient and bed temperature on pumping power and overall cost was determined. This showed the importance of close tube packing and research was undertaken to see if this would adversely affect the heat transfer coefficient. Pressure operation also reduces the pumping power. Fouling and corrosion tests in beds burning coal suggest that higher temperatures could be reached reliably and cost studies show that, provided the better refractory metals are used, the cost of achieving higher temperatures is not unduly high. It now remains to demonstrate at large scale that the proposed systems are viable and that the methods incorporated to overcome start up and part lead running problems are satisfactory. The promising role of these heat transfer techniques in other applications is briefly discussed

  19. Heating great residential units with combustion-motor heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Vossen, W

    1982-10-01

    Economic usage of combustion-motor heat pumps requires: reliable technology and delivery of the heat pump; design and operation. The heat pump must be integrated perfectly into the heating system. This contributions is based on a three-year operational experience with over 150 heat pumps used mainly in residential and administrative buildings (plus commercial buildings, swimming pools, sport centres etc.). These are heat pumps operating on the compression principle with natural gas, liquid gas, or fuel oil.

  20. Elementary heat transfer analysis

    CERN Document Server

    Whitaker, Stephen; Hartnett, James P

    1976-01-01

    Elementary Heat Transfer Analysis provides information pertinent to the fundamental aspects of the nature of transient heat conduction. This book presents a thorough understanding of the thermal energy equation and its application to boundary layer flows and confined and unconfined turbulent flows. Organized into nine chapters, this book begins with an overview of the use of heat transfer coefficients in formulating the flux condition at phase interface. This text then explains the specification as well as application of flux boundary conditions. Other chapters consider a derivation of the tra

  1. Microwave heating denitration device

    International Nuclear Information System (INIS)

    Sato, Hajime; Morisue, Tetsuo.

    1984-01-01

    Purpose: To suppress energy consumption due to a reflection of microwaves. Constitution: Microwaves are irradiated to the nitrate solution containing nuclear fuel materials, to cause denitrating reaction under heating and obtain oxides of the nuclear fuel materials. A microwave heating and evaporation can for reserving the nitrate solution is disposed slantwise relative to the horizontal plane and a microwave heating device is connected to the evaporation can, and inert gases for agitation are supplied to the solution within the can. Since the evaporation can is slanted, wasteful energy consumption due to the reflection of the microwaves can be suppressed. (Moriyama, K.)

  2. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...

  3. Containment condensing heat transfer

    International Nuclear Information System (INIS)

    Gido, R.G.; Koestel, A.

    1983-01-01

    This report presents a mechanistic heat-transfer model that is valid for large scale containment heat sinks. The model development is based on the determination that the condensation is controlled by mass diffusion through the vapor-air boundary layer, and the application of the classic Reynolds' analogy to formulate expressions for the transfer of heat and mass based on hydrodynamic measurements of the momentum transfer. As a result, the analysis depends on the quantification of the shear stress (momentum transfer) at the interface between the condensate film and the vapor-air boundary layer. In addition, the currently used Tagami and Uchida test observations and their range of applicability are explained

  4. Heat pump planning handbook

    CERN Document Server

    Bonin, Jürgen

    2015-01-01

    The Heat Pump Planning Handbook contains practical information and guidance on the design, planning and selection of heat pump systems, allowing engineers, designers, architects and construction specialists to compare a number of different systems and options. Including detailed descriptions of components and their functions and reflecting the current state of technology this guide contains sample tasks and solutions as well as new model calculations and planning evaluations. Also economic factors and alternative energy sources are covered, which are essential at a time of rising heat costs. T

  5. District heating from Forsmark

    International Nuclear Information System (INIS)

    1980-11-01

    The district heating system of Greater Stockholm must be based on other energy sources than oil. Two alternatives are assessed, namely heat from Forsmark or a coal fueled plant in the region of Stockholm. Forsmark 3 can produce both electricity and heat from the year 1988 on. The capacity can be increased by coal fueled blocks. For low electricity use, 115 TWh in the year 1990, the Forsmark alternative will be profitable. The alternative will be profitable. The alternative with a fossile fuelled plant will be profitable when planning for high consumption of electricity, 125 TWh. The Forsmark alternative means high investments and the introduction of new techniques. (G.B.)

  6. Waste heat recovery system

    International Nuclear Information System (INIS)

    Phi Wah Tooi

    2010-01-01

    Full text: The Konzen in-house designed anaerobic digester system for the POME (Palm Oil Mill Effluent) treatment process is one of the registered Clean Development Mechanism (CDM) projects in Malaysia. It is an organic wastewater treatment process which achieves excellent co-benefits objectives through the prevention of water pollution and reduction of greenhouse gas emissions, which is estimated to be 40,000 to 50,000 t-CO 2 per year. The anaerobic digester was designed in mesophile mode with temperature ranging from 37 degree Celsius to 45 degree Celsius. A microorganisms growth is optimum under moderately warm temperature conditions. The operating temperature of the anaerobic digester needs to be maintained constantly. There are two waste heat recovery systems designed to make the treatment process self-sustaining. The heat recovered will be utilised as a clean energy source to heat up the anaerobic digester indirectly. The first design for the waste heat recovery system utilises heat generated from the flue gas of the biogas flaring system. A stainless steel water tank with an internal water layer is installed at the top level of the flare stack. The circulating water is heated by the methane enriched biogas combustion process. The second design utilizes heat generated during the compression process for the biogas compressor operation. The compressed biogas needs to be cooled before being recycled back into the digester tank for mixing purposes. Both the waste heat recovery systems use a design which applies a common water circulation loop and hot water tank to effectively become a closed loop. The hot water tank will perform both storage and temperature buffer functions. The hot water is then used to heat up recycled sludge from 30 degree Celsius to 45 degree Celsius with the maximum temperature setting at 50 degree Celsius. The recycled sludge line temperature will be measured and monitored by a temperature sensor and transmitter, which will activate the

  7. Heat treatment furnace

    Science.gov (United States)

    Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

    2014-10-21

    A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

  8. [Clothing and heat disorder].

    Science.gov (United States)

    Satsumoto, Yayoi

    2012-06-01

    The influence of the clothing material properties(like water absorbency and rapid dryness, water vapor absorption, water vapor permeability and air permeability) and the design factor of the clothing(like opening condition and fitting of clothing), which contributed to prevent heat disorder, was outlined. WBGT(wet-bulb globe temperature) is used to show a guideline for environmental limitation of activities to prevent heat disorder. As the safety function is more important than thermal comfort for some sportswear and protective clothing with high cover area, clothing itself increases the risk of heat disorder. WBGT is corrected by CAF (clothing adjustment factor) in wearing such kind of protective clothing.

  9. Decentralized central heating

    Energy Technology Data Exchange (ETDEWEB)

    Savic, S.; Hudjera, A.

    1994-08-04

    The decentralized central heating is essentially based on new technical solutions for an independent heating unit, which allows up to 20% collectible energy savings and up to 15% savings in built-in-material. These savings are already made possible by the fact that the elements described under point A are thus eliminated from the classical heating. The thus superfluous made elements are replaced by new technical solutions described under point B - technical problem - and point E - patent claim. The technical solutions described in detail under point B and point E form together a technical unit and are essential parts of the invention protected by the patent. (author)

  10. Modeling of heat transfer into a heat pipe for a localized heat input zone

    International Nuclear Information System (INIS)

    Rosenfeld, J.H.

    1987-01-01

    A general model is presented for heat transfer into a heat pipe using a localized heat input. Conduction in the wall of the heat pipe and boiling in the interior structure are treated simultaneously. The model is derived from circumferential heat transfer in a cylindrical heat pipe evaporator and for radial heat transfer in a circular disk with boiling from the interior surface. A comparison is made with data for a localized heat input zone. Agreement between the theory and the model is good. This model can be used for design purposes if a boiling correlation is available. The model can be extended to provide improved predictions of heat pipe performance

  11. Radiation effects on heat transfer in heat exchangers, (2)

    International Nuclear Information System (INIS)

    Mori, Yasuo; Watanabe, Kenji; Taira, Tatsuji.

    1980-01-01

    In a high temperature gas-cooled reactor system, in which the working fluid exchanges heat at high temperature near 1000 deg C, the heat transfer acceleration by positively utilizing the radiation heat transfer between solid surfaces should be considered. This paper reports on the results of experiment and analysis for the effects of radiant heat on the heat transfer performance at elevated temperature by applying the heat transfer-accelerating method using radiators to the heat exchanger with tube bundle composed of two channels of heating and heated sides. As the test heat exchangers, a parallel counter flow exchanger and the cross flow exchanger simulating helical tubes were employed, and the results studied on the characteristics of each heat exchanger are described. The plates placed in parallel to flow in every space of the tube bundle arranged in a matrix were used as the heat transfer accelerator. The effects of acceleration with the plates were the increase of heat transmission from 12 to 24% and 12 to 38% in the parallel flow and cross flow heat exchangers, respectively. Also, it was clarified that the theoretical analysis, in which it was assumed that the region within pitch S and two radiator plates, with a heat-transferring tube placed at the center, is the minimum domain for calculation, and that the heat exchange by radiation occurs only between the domain and the adjacent domains, can estimate the heat transfer-accelerating effect and the temperature distribution in a heat exchanger with sufficient accuracy. (Wakatsuki, Y.)

  12. Design of serially connected district heating heat pumps utilising a geothermal heat source

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Ommen, Torben Schmidt; Markussen, Wiebke Brix

    2017-01-01

    The design of two heat pumps (HP), connected in series, was investigated for operation in the district heating (DH) network of the Greater Copenhagen area, Denmark. The installation was dimensioned to supply 7.2 MW of heat at a temperature of 85 °C. The heat pumps utilise a geothermal heat source...

  13. Heat Transfer in Health and Healing.

    Science.gov (United States)

    Diller, Kenneth R

    2015-10-01

    Our bodies depend on an exquisitely sensitive and refined temperature control system to maintain a state of health and homeostasis. The exceptionally broad range of physical activities that humans engage in and the diverse array of environmental conditions we face require remarkable strategies and mechanisms for regulating internal and external heat transfer processes. On the occasions for which the body suffers trauma, therapeutic temperature modulation is often the approach of choice for reversing injury and inflammation and launching a cascade of healing. The focus of human thermoregulation is maintenance of the body core temperature within a tight range of values, even as internal rates of energy generation may vary over an order of magnitude, environmental convection, and radiation heat loads may undergo large changes in the absence of any significant personal control, surface insulation may be added or removed, all occurring while the body's internal thermostat follows a diurnal circadian cycle that may be altered by illness and anesthetic agents. An advanced level of understanding of the complex physiological function and control of the human body may be combined with skill in heat transfer analysis and design to develop life-saving and injury-healing medical devices. This paper will describe some of the challenges and conquests the author has experienced related to the practice of heat transfer for maintenance of health and enhancement of healing processes.

  14. Pulsating Heat Pipes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An advanced heat transport technology is presented that can enable space nuclear power systems to transfer reactor heat, convert heat into electricity, reject waste...

  15. Absorption heat pumps

    International Nuclear Information System (INIS)

    Formigoni, C.

    1998-01-01

    A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it

  16. HEAT TRANSFER METHOD

    Science.gov (United States)

    Gambill, W.R.; Greene, N.D.

    1960-08-30

    A method is given for increasing burn-out heat fluxes under nucleate boiling conditions in heat exchanger tubes without incurring an increase in pumping power requirements. This increase is achieved by utilizing a spinning flow having a rotational velocity sufficient to produce a centrifugal acceleration of at least 10,000 g at the tube wall. At this acceleration the heat-transfer rate at burn out is nearly twice the rate which can be achieved in a similar tube utilizing axial flow at the same pumping power. At higher accelerations the improvement over axial flow is greater, and heat fluxes in excess of 50 x 10/sup 6/ Btu/hr/sq ft can be achieved.

  17. Heat and mass transfer

    CERN Document Server

    Karwa, Rajendra

    2017-01-01

    This textbook presents the classical treatment of the problems of heat transfer in an exhaustive manner with due emphasis on understanding of the physics of the problems. This emphasis is especially visible in the chapters on convective heat transfer. Emphasis is laid on the solution of steady and unsteady two-dimensional heat conduction problems. Another special feature of the book is a chapter on introduction to design of heat exchangers and their illustrative design problems. A simple and understandable treatment of gaseous radiation has been presented. A special chapter on flat plate solar air heater has been incorporated that covers thermo-hydraulic modeling and simulation. The chapter on mass transfer has been written looking specifically at the needs of the students of mechanical engineering. The book includes a large number and variety of solved problems with supporting line diagrams. The author has avoided duplicating similar problems, while incorporating more application-based examples. All the end-...

  18. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... exhaustion symptoms include cool, moist, pale or flushed skin; headache; dizziness; weakness; feeling exhausted; heavy sweating; nausea; ... stage of heat illness) include flushed, hot, dry skin; fainting; a rapid, weak pulse; rapid, shallow breathing; ...

  19. Policies for Renewable Heat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This paper builds on IEA publications, Deploying Renewables, Principles for Effective Policies and Deploying Renewables, Best and Future Policy Practice, that discuss the 'integrated policy approach,' whereby renewable energy technologies require different support policies at different stages of their maturity pathways. The paper discusses how the integrated policy approach applies to renewable heat. It attempts to provide guidance for policy-makers on renewable heat throughout the different phases of the policy lifecycle, allowing for the specific challenges of renewable heat and needs of the many stakeholders involved. Stimulating a market for heat involves challenges that are different and, often, more difficult to overcome than in the electricity and transport sectors.

  20. Passive solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Wiberg, K

    1981-11-10

    The present work treats the possibilities for heating according to the passive solar heating method. Problems of 'spatial organization in an energy-saving society' are distinguished from among other social problems. The final delimination of the actual problems under investigation consists of the use of passive solar heating and especially the 'consequences of such solar heating exploitation upon the form and structures' of planning and construction. In the concluding chapter an applied example shows how this method can be used in designing an urban area and what are its limitations. The results indicate the possibilities and difficulties in attempting to transfer this ideal and general method into models and directives for form and structure from which examples of the actual possibilities in practical planning can be given.

  1. Active transport and heat.

    Science.gov (United States)

    Tait, Peter W

    2011-07-01

    Increasing heat may impede peoples' ability to be active outdoors thus limiting active transport options. Co-benefits from mitigation of and adaptation to global warming should not be assumed but need to be actively designed into strategies.

  2. Heat Island Compendium

    Science.gov (United States)

    Heat islands can be mitigated through measures like planting trees and vegetation, installing green roofs and cool roofs, and using cool pavements. The compendium describes all of these strategies and shows how communities around the country are being used

  3. Radiative heat transfer

    CERN Document Server

    Modest, Michael F

    2013-01-01

    The third edition of Radiative Heat Transfer describes the basic physics of radiation heat transfer. The book provides models, methodologies, and calculations essential in solving research problems in a variety of industries, including solar and nuclear energy, nanotechnology, biomedical, and environmental. Every chapter of Radiative Heat Transfer offers uncluttered nomenclature, numerous worked examples, and a large number of problems-many based on real world situations-making it ideal for classroom use as well as for self-study. The book's 24 chapters cover the four major areas in the field: surface properties; surface transport; properties of participating media; and transfer through participating media. Within each chapter, all analytical methods are developed in substantial detail, and a number of examples show how the developed relations may be applied to practical problems. It is an extensive solution manual for adopting instructors. Features: most complete text in the field of radiative heat transfer;...

  4. Computed Heats of Formation

    National Research Council Canada - National Science Library

    Politzer, Peter

    1998-01-01

    ..., the heats of vaporization and sublimation. The latter are determined by means of relationships that we have developed involving the computed electrostatic potential on the molecular surface 2,3...

  5. Heat and spin interconversion

    International Nuclear Information System (INIS)

    Ohnuma, Yuichi; Matsuo, Mamoru; Maekawa, Sadamichi; Saitoh, Eeiji

    2017-01-01

    Spin Seebeck and spin Peltier effects, which are mutual conversion phenomena of heat and spin, are discussed on the basis of the microscopic theory. First, the spin Seebeck effect, which is the spin-current generation due to heat current, is discussed. The recent progress in research on the spin Seebeck effect are introduced. We explain the origin of the observed sign changes of the spin Seebeck effect in compensated ferromagnets. Next, the spin Peltier effect, which is the heat-current generation due to spin current, is discussed. Finally, we show that the spin Seebeck and spin Peltier effects are summarized by Onsager's reciprocal relation and derive Kelvin's relation for the spin and heat transports. (author)

  6. Analytical heat transfer

    CERN Document Server

    Han, Je-Chin

    2012-01-01

    … it will complete my library … [and] complement the existing literature on heat transfer. It will be of value for both graduate students and faculty members.-Bengt Sunden, Lund University, Sweden

  7. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Your Wishes Visiting The ER Who Takes Care Of You In An Emergency? Checking Into ... Illnesses Dr. Glenn Mitchell , Emergency physician at Mercy Health System in Chesterfield, Missouri Heat-related illness can be ...

  8. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Health System in Chesterfield, Missouri Heat-related illness can be caused by overexposure to the sun or ... the elderly are most at risk, but anyone can be affected. Here you will find information about ...

  9. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... moist, pale skin, rapid pulse, elevated or lowered blood pressure, nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool the person further by positioning ...

  10. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... ICE” in Your Cell Phone Prepare for Disasters Communication With Your Family And Your Doctor About Your ... Dr. Glenn Mitchell , Emergency physician at Mercy Health System in Chesterfield, Missouri Heat-related illness can be ...

  11. Beam induced RF heating

    CERN Document Server

    Salvant, B; Arduini, G; Assmann, R; Baglin, V; Barnes, M J; Bartmann, W; Baudrenghien, P; Berrig, O; Bracco, C; Bravin, E; Bregliozzi, G; Bruce, R; Bertarelli, A; Carra, F; Cattenoz, G; Caspers, F; Claudet, S; Day, H; Garlasche, M; Gentini, L; Goddard, B; Grudiev, A; Henrist, B; Jones, R; Kononenko, O; Lanza, G; Lari, L; Mastoridis, T; Mertens, V; Métral, E; Mounet, N; Muller, J E; Nosych, A A; Nougaret, J L; Persichelli, S; Piguiet, A M; Redaelli, S; Roncarolo, F; Rumolo, G; Salvachua, B; Sapinski, M; Schmidt, R; Shaposhnikova, E; Tavian, L; Timmins, M; Uythoven, J; Vidal, A; Wenninger, J; Wollmann, D; Zerlauth, M

    2012-01-01

    After the 2011 run, actions were put in place during the 2011/2012 winter stop to limit beam induced radio frequency (RF) heating of LHC components. However, some components could not be changed during this short stop and continued to represent a limitation throughout 2012. In addition, the stored beam intensity increased in 2012 and the temperature of certain components became critical. In this contribution, the beam induced heating limitations for 2012 and the expected beam induced heating limitations for the restart after the Long Shutdown 1 (LS1) will be compiled. The expected consequences of running with 25 ns or 50 ns bunch spacing will be detailed, as well as the consequences of running with shorter bunch length. Finally, actions on hardware or beam parameters to monitor and mitigate the impact of beam induced heating to LHC operation after LS1 will be discussed.

  12. Pulse induction heating

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, A S; Kachanov, B Y; Kogan, B V

    1993-12-31

    Induction heating and three types of pulse processes were studied. It was found that in pulse processes the frequency and pulse duration of heat treatments do not remain constant. High frequency pulse heat treatments can be used on sprayed coatings; such treatments will result in stronger surfaces with no cracks. For induction hardening, the rate of specific power was 1 to 1.5 kW/sq.cm, for forging it was 0.2 to 0.3 kW/sq.cm and for melting it was 0.05 to 0.1 kW/sq.cm. The application of pulse heating will result in higher rates of specific power.

  13. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... weak pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with ... nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool ...

  14. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... or a high body temperature. For late stage heat stroke symptoms, cool the person further by positioning ice or cold packs on ... Injury Chest Pain Is ALWAYS A Reason To Go To The ...

  15. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... weak pulse; rapid, shallow breathing; vomiting; and increased body temperature of more than 104 degrees. People with these ... nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, cool the ...

  16. Heat transport and storage

    International Nuclear Information System (INIS)

    Despois, J.

    1977-01-01

    Recalling the close connections existing between heat transport and storage, some general considerations on the problem of heat distribution and transport are presented 'in order to set out the problem' of storage in concrete form. This problem is considered in its overall plane, then studied under the angle of the different technical choices it involves. The two alternatives currently in consideration are described i.e.: storage in a mined cavity and underground storage as captive sheet [fr

  17. Heat transfer. V. 1

    International Nuclear Information System (INIS)

    1992-01-01

    This volume contains the 4 key-note lectures and 83 of the 148 papers presented at the 3rd UK National Conference on Heat Transfer. The papers are grouped under the following broad headings: boiling and condensation; heat exchangers; refrigeration and air-conditioning; natural convection; process safety and nuclear reactors; two-phase flow; post dry-out; combustion, radiation and chemical reaction. Separate abstracts have been prepared for 13 papers of relevance to nuclear reactors. (UK)

  18. Solar heating and cooling.

    Science.gov (United States)

    Duffie, J A

    1976-01-01

    Solar energy is discussed as an energy resource that can be converted into useful energy forms to meet a variety of energy needs. The review briefly explains the nature of this energy resource, the kinds of applications that can be made useful, and the status of several systems to which it has been applied. More specifically, information on solar collectors, solar water heating, solar heating of buildings, solar cooling plus other applications, are included.

  19. Heat flux limiting sleeves

    Science.gov (United States)

    Harris, William G.

    1985-01-01

    A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

  20. Protected isotope heat source

    International Nuclear Information System (INIS)

    Burns, R.K.; Shure, L.I.; Katzen, E.D.

    1975-01-01

    A radioactive isotope capsule is disposed in a container (heat shield) which will have a single stable trim attitude when reentering the earth's atmosphere and while falling to earth. The center of gravity of the heat source is located forward of the midpoint between the front face and the rear face of the container. The capsule is insulated from the front face of the container but not from the rear surface of the container. (auth)

  1. Heat exchanger cleaning

    International Nuclear Information System (INIS)

    Gatewood, J.R.

    1980-01-01

    A survey covers the various types of heat-exchange equipment that is cleaned routinely in fossil-fired generating plants, the hydrocarbon-processing industry, pulp and paper mills, and other industries; the various types, sources, and adverse effects of deposits in heat-exchange equipment; some details of the actual procedures for high-pressure water jetting and chemical cleaning of some specific pieces of equipment, including nuclear steam generators. (DN)

  2. VII international district heating conference

    International Nuclear Information System (INIS)

    1988-01-01

    The proceedings of the 7th International District Heating Conference contain the full texts of the 89 presented papers of which 11 fall under the INIS Subject Scope. The conference met in seven sessions and dealt with the following problem areas: design and optimization of systems of district heating, integration of the power system and the district heating systems, cooperation of nuclear and fossil burning sources in district heating systems, the use of specific nuclear power plants for heating purposes, questions of the control of systems of district heating, the development of components of heating networks, the reliability and design of heat supply pipes. (Z.M.)

  3. Design and Modeling of a Variable Heat Rejection Radiator

    Science.gov (United States)

    Miller, Jennifer R.; Birur, Gajanana C.; Ganapathi, Gani B.; Sunada, Eric T.; Berisford, Daniel F.; Stephan, Ryan

    2011-01-01

    Variable Heat Rejection Radiator technology needed for future NASA human rated & robotic missions Primary objective is to enable a single loop architecture for human-rated missions (1) Radiators are typically sized for maximum heat load in the warmest continuous environment resulting in a large panel area (2) Large radiator area results in fluid being susceptible to freezing at low load in cold environment and typically results in a two-loop system (3) Dual loop architecture is approximately 18% heavier than single loop architecture (based on Orion thermal control system mass) (4) Single loop architecture requires adaptability to varying environments and heat loads

  4. Refrigeration waste heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    1983-03-01

    UK Super A Stores was built in 1972 and is part of a small indoor shopping complex linked together by a heated mall. The store has a public floor area of approximately 1,232 m{sup 2} (13,261 ft.{sup 2}) and sells the usual variety of food produce including a large selection of frozen foods. There are five lengths of refrigerated display cabinets with a total area of approximately 78 m{sup 2}. There are also some frozen food storage rooms at the back of the store. This report provides a description of a waste heat recovery system within a medium sized food store. It details how the waste heat that is produced by the conventional frozen food display cabinets, can be reused by the store's space heating system. Recommended uses for this waste heat include: diverting to the loading bays which would make the reheat coil unnecessary, diverting to the front of the shop, and heating the adjacent shopping mall. The CREDA (Conservation and Renewable Energy Demonstration Assistance) program contributed $17,444 towards the total project cost of $30,444. The project was initiated by the store owner, who is now realizing a lower annual fuel consumption, with the resulting financial savings. 11 figs., 1 tab.

  5. Radial flow heat exchanger

    Science.gov (United States)

    Valenzuela, Javier

    2001-01-01

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  6. Convective heat flow probe

    Science.gov (United States)

    Dunn, James C.; Hardee, Harry C.; Striker, Richard P.

    1985-01-01

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packer-type seals are provided along the probe above and below the heater pads.

  7. Optimal usage of low temperature heat sources to supply district heating by heat pumps

    DEFF Research Database (Denmark)

    Pieper, Henrik; Ommen, Torben Schmidt; Markussen, Wiebke Brix

    2017-01-01

    This paper presents a theoretical study on the optimal usage of different low temperature heat sources to supply district heating by heat pumps. The study is based on data for the Copenhagen region. The heat sources were prioritized based on the coefficient of performance calculated for each hour...... and the covered demand of each heat source as well as required peak unit capacity. The results showed that heat pumps using different heat sources yield better performance than a heat pump based on a single one. The performance was influenced by the composition of the different heat sources. It was found that 78......% groundwater, 22% seawater and 0% air resulted in highest COP of 3.33 for the given heat demand. Furthermore, the implementation of rule based short term storage made peak units redundant. The variation in base load capacity showed that heat pumps utilizing the analyzed heat sources could perform very...

  8. Density distribution of currents induced inside the brain in the heat part of the human model exposed to power frequency electric field; Denryoku shuhasu no denkai ni yori jintai model tobu nonai ni yudosareru denryu mitsudo bunpu

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, A. [Yonago National College of Technology, Tottori (Japan); Isaka, K. [The University of Tokushima, Tokushima (Japan); Kaune, W.

    1998-06-01

    The health effect of the weak current induced in the human body as a result of the interaction between human body and power frequency electric fields has been investigated. However, the current density inside the head part tissues of the human body exposed to the electric fields has little been discussed. In this paper, the finite element method is applied to the analysis of the current density distributions of the head part composed of scalp, skull, cerebrospinal liquid and brain tissues. The basic characteristics of the current density distributions of the brain in the bead part of the axisymmetrical human model have been made clear. 13 refs., 12 figs., 2 tabs.

  9. Heat transfer capability analysis of heat pipe for space reactor

    International Nuclear Information System (INIS)

    Li Huaqi; Jiang Xinbiao; Chen Lixin; Yang Ning; Hu Pan; Ma Tengyue; Zhang Liang

    2015-01-01

    To insure the safety of space reactor power system with no single point failures, the reactor heat pipes must work below its heat transfer limits, thus when some pipes fail, the reactor could still be adequately cooled by neighbor heat pipes. Methods to analyze the reactor heat pipe's heat transfer limits were presented, and that for the prevailing capillary limit analysis was improved. The calculation was made on the lithium heat pipe in core of heat pipes segmented thermoelectric module converter (HP-STMC) space reactor power system (SRPS), potassium heat pipe as radiator of HP-STMC SRPS, and sodium heat pipe in core of scalable AMTEC integrated reactor space power system (SAIRS). It is shown that the prevailing capillary limits of the reactor lithium heat pipe and sodium heat pipe is 25.21 kW and 14.69 kW, providing a design margin >19.4% and >23.6%, respectively. The sonic limit of the reactor radiator potassium heat pipe is 7.88 kW, providing a design margin >43.2%. As the result of calculation, it is concluded that the main heat transfer limit of HP-STMC SRPS lithium heat pipe and SARIS sodium heat pipe is prevailing capillary limit, but the sonic limit for HP-STMC SRPS radiator potassium heat pipe. (authors)

  10. Heat exchanger device and method for heat removal or transfer

    Science.gov (United States)

    Koplow, Jeffrey P

    2013-12-10

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  11. Heat transfer characteristics of a direct contact heat exchanger

    International Nuclear Information System (INIS)

    Kinoshita, I.; Nishi, Y.

    1993-01-01

    As a first step for development of a direct contact steam generator for FBRs, fundamental heat transfer characteristics of a liquid-liquid contact heat exchanger were evaluated by heat transfer experiment with low melting point alloy and water. Distinctive characteristics of direct contact heat transfer with liquid metal and water was obtained. (author)

  12. Passive heat removal from containment

    International Nuclear Information System (INIS)

    Gou, P.F.; Townsend, H.E.

    1990-01-01

    This patent describes a heat removal system for removing heat from a containment of a nuclear reactor. It comprises: a sealed suppression chamber in the containment; means for venting steam from the nuclear reactor into the suppression chamber upon occurrence of an event requiring dissipation of heat from the nuclear reactor. The suppression chamber containing a quantity of water; the suppression chamber having a gas-containing space above the water; a heat exchanger disposed within the gas-containing space of the suppression chamber; the heat exchanger including an enclosed structure for holding a heat-exchange fluid; means for metering a supply of heat-exchange fluid to the heat exchanger to maintain a predetermined level thereof in the enclosed structure. The heat-exchange fluid boiling in the heat exchanger in consequence of heat transfer thereto from steam present in the suppression chamber; means for separating a heat-exchange fluid vapor in the heat exchanger from the heat-exchange fluid; and means for discharging the vapor immediately following its separation from heat-exchange fluid directly from the heat exchanger to a location exterior of the containment, whereby heat is discharged from the suppression chamber, and the containment is maintained at a temperature and pressure below its design value

  13. Heating plant privatization stagnates

    International Nuclear Information System (INIS)

    Janoska, J.; Benka, M.; Sobinkovic, B.; Haluza, I.

    2005-01-01

    The state has been talking about privatization of 6 municipal heating plants since 2001. The tenders were to start last year. But nothing has happened and the future is uncertain. The city councils would prefer to receive, if not 100%, then at least a majority stake in the heating plants free of charge. But the Cabinet has decided to sell 51% to investors. The privatization agency - the National Property Fund (FNM) is preparing a proposal to increase the stake offered for sale to 67%. According to information provided by the FNM the sale will begin after Cabinet approval. The Fund intends to apply the same model to the sale of all the heating plants. Last year, a major German company Verbundnetz Gas declared its interest in purchasing large municipal heating plants in Slovakia. But it has been waiting for a response ever since. The French company - Dalkia, which has 10-years' experience of doing business in Slovakia, is interested in all the heating plants to be offered for sale. The Austrian company - Stefe is not new to the business either, it is interested mainly in the regions where it has already established itself - Central and Eastern Slovakia. Strategic investors expect financial groups to show interest too. The Penta Group has not hid its ambitions - it has already privatised a company which represents the key to the future development of heat management in Bratislava - Paroplynovy cyklus. Whereas Penta is not new to the heat production business another financial group - Slavia Capital is still surveying the sector. Should it not succeed, it plans several projects that would allow it to take a stake in the sector

  14. Ground Source Heat Pump in Heating System with Electronics Monitoring

    Directory of Open Access Journals (Sweden)

    NEAMŢU Ovidiu

    2013-10-01

    Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

  15. Innovative heat exchangers

    CERN Document Server

    Scholl, Stephan

    2018-01-01

    This accessible book presents unconventional technologies in heat exchanger design that have the capacity to provide solutions to major concerns within the process and power-generating industries. Demonstrating the advantages and limits of these innovative heat exchangers, it also discusses micro- and nanostructure surfaces and micro-scale equipment, and introduces pillow-plate, helical and expanded metal baffle concepts. It offers step-by-step worked examples, which provide instructions for developing an initial configuration and are supported by clear, detailed drawings and pictures. Various types of heat exchangers are available, and they are widely used in all fields of industry for cooling or heating purposes, including in combustion engines. The market in 2012 was estimated to be U$ 42.7 billion and the global demand for heat exchangers is experiencing an annual growth of about 7.8 %. The market value is expected to reach U$ 57.9 billion in 2016, and approach U$ 78.16 billion in 2020. Providing a valua...

  16. Heat exchanger restart evaluation

    International Nuclear Information System (INIS)

    Morrison, J.M.; Hirst, C.W.; Lentz, T.F.

    1992-01-01

    On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat exchanger 4A (HX 4A). The heat exchanger was isolated and the plant shutdown. Heat exchanger 4A was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the identified tube. The leaking tube was removed and examined metallurgically to determine the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat exchanger 4A for metallurgical examination. Additional analysis and review of heat exchanger leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summary herein

  17. Heat exchanger restart evaluation

    International Nuclear Information System (INIS)

    Morrison, J.M.; Hirst, C.W.; Lentz, T.F.

    1992-01-01

    On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat exchanger 4A (HX 4A). The heat exchanger was isolated and the plant shutdown. Heat exchanger 4kA was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat exchanger 4A for metallurgical examination. Additional analysis and review of heat exchanger leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized herein

  18. Heat exchanger restart evaluation

    International Nuclear Information System (INIS)

    Morrison, J.M.; Hirst, C.W.; Lentz, T.F.

    1992-01-01

    On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat exchanger 4A (HX 4A). The heat exchanger was isolated and the plant shutdown. Heat exchanger 4A was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the identified tube. The leaking tube was removed and examined metallurgically to determine the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat exchanger 4A for metallurgical examination. Additional analysis and review of heat exchanger leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized

  19. Heat simulation via Scilab programming

    Science.gov (United States)

    Hasan, Mohammad Khatim; Sulaiman, Jumat; Karim, Samsul Arifin Abdul

    2014-07-01

    This paper discussed the used of an open source sofware called Scilab to develop a heat simulator. In this paper, heat equation was used to simulate heat behavior in an object. The simulator was developed using finite difference method. Numerical experiment output show that Scilab can produce a good heat behavior simulation with marvellous visual output with only developing simple computer code.

  20. Solar Process Heat Basics | NREL

    Science.gov (United States)

    Process Heat Basics Solar Process Heat Basics Commercial and industrial buildings may use the same solar technologies-photovoltaics, passive heating, daylighting, and water heating-that are used for residential buildings. These nonresidential buildings can also use solar energy technologies that would be

  1. After-heat removing device

    International Nuclear Information System (INIS)

    Iwashige, Kengo; Otsuka, Masaya; Yokoyama, Iwao; Yamakawa, Masanori.

    1990-01-01

    The present invention concerns an after-heat removing device for first reactors. A heat accumulation portion provided in a cooling channel of an after-heat removing device is disposed before a coil-like heat conduction pipe for cooling of the after-heat removing device. During normal reactor operation, the temperature in the heat accumulation portion is near the temperature of the high temperature plenum due to heat conduction and heat transfer from the high temperature plenum. When the reactor is shutdown and the after-heat removing device is started, coolants cooled in the air cooler start circulation. The coolants arriving at the heat accumulation portion deprive heat from the heat accumulation portion and, ion turn, increase their temperature and then reach the cooling coil. Subsequently, the heat calorie possessed in the heat accumulation portion is reduced and the after-heat removing device is started for the operation at a full power. This can reduce the thermal shocks applied to the cooling coil or structures in a reactor vessel upon starting the after-heat removing device. (I.N.)

  2. Experiments Demonstrate Geothermal Heating Process

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    When engineers design heat-pump-based geothermal heating systems for homes and other buildings, they can use coil loops buried around the perimeter of the structure to gather low-grade heat from the earth. As an alternative approach, they can drill well casings and store the summer's heat deep in the earth, then bring it back in the winter to warm…

  3. Structures to radiate heat softly

    Energy Technology Data Exchange (ETDEWEB)

    Perilae, T.; Wikstroem, T. [ed.

    1997-11-01

    Over the past fifty years, heating systems in single-family houses have taken a great leap forward. First wood-burning stoves gave way to oil heaters; then these were superseded by central heating systems; and now conventional central heating systems have lost their way with the increasingly widespread use of room-specific heating systems

  4. Targeting the maximum heat recovery for systems with heat losses and heat gains

    International Nuclear Information System (INIS)

    Wan Alwi, Sharifah Rafidah; Lee, Carmen Kar Mun; Lee, Kim Yau; Abd Manan, Zainuddin; Fraser, Duncan M.

    2014-01-01

    Graphical abstract: Illustration of heat gains and losses from process streams. - Highlights: • Maximising energy savings through heat losses or gains. • Identifying location where insulation can be avoided. • Heuristics to maximise heat losses or gains. • Targeting heat losses or gains using the extended STEP technique and HEAT diagram. - Abstract: Process Integration using the Pinch Analysis technique has been widely used as a tool for the optimal design of heat exchanger networks (HENs). The Composite Curves and the Stream Temperature versus Enthalpy Plot (STEP) are among the graphical tools used to target the maximum heat recovery for a HEN. However, these tools assume that heat losses and heat gains are negligible. This work presents an approach that considers heat losses and heat gains during the establishment of the minimum utility targets. The STEP method, which is plotted based on the individual, as opposed to the composite streams, has been extended to consider the effect of heat losses and heat gains during stream matching. Several rules to guide the proper location of pipe insulation, and the appropriate procedure for stream shifting have been introduced in order to minimise the heat losses and maximise the heat gains. Application of the method on two case studies shows that considering heat losses and heat gains yield more realistic utility targets and help reduce both the insulation capital cost and utility cost of a HEN

  5. Optimization criteria for low temperature waste heat utilization

    International Nuclear Information System (INIS)

    Kranebitter, F.

    1977-01-01

    A special case in this field is the utilization of very low temperature waste heat. The temperature level under consideration in this paper is in the range between the body temperature of human beings and their environment. The waste heat from power generation and industrial processes is also considered. Thermal energy conversion will be mainly accomplished by heat cycles where discharged waste heat is reverse proportional to the upper cycle temperature. Limiting this upper cycle temperature by technological reasons the optimization of the heat cycle will depend on the nature of the cycle itself and specially on the temperature selected for the heat discharge. The waste heat discharge is typical for the different kinds of heat cycles and the paper presents the four most important of them. Feasible heat transfer methods and their economic evaluations are discussed and the distillation processes will be the basis for further considerations. The waste heat utilization for distillation purposes could be realized by three different cycles, the open cycle, the closed cycle and the multy cycle. Resulting problems as deaeration of large water streams and removal of the dissolved gases and their solutions are also discussed. (M.S.)

  6. Mapping of potential heat sources for heat pumps for district heating in Denmark

    International Nuclear Information System (INIS)

    Lund, Rasmus; Persson, Urban

    2016-01-01

    The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose. In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark. - Highlights: • The availability of heat sources for heat pumps in Denmark are mapped and quantified. • A novel methodology for assessment of low temperature industrial excess heat is presented. • There are heat sources available for 99% of district heating networks in Denmark. • The concentration of heat sources is generally bigger around bigger cities than smaller. • Ambient temperature heat sources will be more needed in district heating of big cities.

  7. Heat transfer fluids containing nanoparticles

    Science.gov (United States)

    Singh, Dileep; Routbort, Jules; Routbort, A.J.; Yu, Wenhua; Timofeeva, Elena; Smith, David S.; France, David M.

    2016-05-17

    A nanofluid of a base heat transfer fluid and a plurality of ceramic nanoparticles suspended throughout the base heat transfer fluid applicable to commercial and industrial heat transfer applications. The nanofluid is stable, non-reactive and exhibits enhanced heat transfer properties relative to the base heat transfer fluid, with only minimal increases in pumping power required relative to the base heat transfer fluid. In a particular embodiment, the plurality of ceramic nanoparticles comprise silicon carbide and the base heat transfer fluid comprises water and water and ethylene glycol mixtures.

  8. WAYS TO MANAGE HEATING INERTIA

    Directory of Open Access Journals (Sweden)

    E. V. Biloshytskyi

    2017-08-01

    Full Text Available Purpose. The research paper proposes to estimate the effect of heat inertia of the water heating system, in transient operation modes, on the temperature condition in the passenger car, as well as to offer technical solutions intended to reduce the heating system inertia effect and to maintain a stable temperature condition in the passenger car premises in transitional modes of the heating system. Methodology. The author developed the method for controlling the heat transfer of heating system pipes with the help of regulating casing. To control the heating system and the heat transfer of heating pipes, two types of temperature control sensors were used in the passenger car: certain sensors interacted with regulatory casings, while the others interacted with high-voltage tubular heating element control devices. To assess the efficiency of heat interchange regulation of heating pipes and the heating system control, with installed regulating casings, the operation of the heating system with regulating casings and two types of sensors was mathematically modelled. Mathematical modelling used the experimental test data. The results of experimental tests and mathematical modelling were compared. Findings. Currently in operated passenger cars, control of heating appliances is not constructively provided. Automatic maintenance of the set temperature in a passenger car is limited to switching on and off of high-voltage tubular heating elements. The use of regulating casings on heating pipes allows reducing the effects of heat inertia and maintaining stable thermal conditions in a passenger car, using the heating system as a heat accumulator, and also provides the opportunity to realize an individual control of air temperature in the compartment. Originality. For the first time, the paper studied the alternative ways of regulating the temperature condition in a passenger car. Using of the heating system as a heat accumulator. Practical value. The

  9. Heat and power from combustibles

    International Nuclear Information System (INIS)

    Zogg, M.

    2002-01-01

    This article compares four ways of generating heat and power from liquid and gaseous fuels. Various combinations of conventional boilers, heat pumps, combined heat and power units and combined-cycle power plants are considered and the ratio of heat to electrical power produced is discussed. Fuel requirements for the four combinations are looked at and net emissions of carbon dioxide, oxides of nitrogen and carbon monoxide presented in graphical form. The author makes recommendations on the choice of the technology to be used to generate heat and electricity for different heat/power ratios and criticises the all too slack emission limits for small combined heat and power units

  10. Nuclear district heating

    International Nuclear Information System (INIS)

    Ricateau, P.

    1976-01-01

    An economic study of nuclear district heating is concerned with: heat production, its transmission towards the area to be served and the distribution management towards the consumers. Foreign and French assessments show that the high cost of now existing techniques of hot water transport defines the competing limit distance between the site and township to be below some fifty kilometers for the most important townships (provided that the fuel price remain stationary). All studies converge towards the choice of a high transport temperature as soon as the distance is of some twenty kilometers. As for fossile energy saving, some new possibilities appear with process heat reactors; either PWR of about 1000MWth for large townships, or pool-type reactors of about 100MWth when a combination with an industrial steam supply occurs [fr

  11. Shape memory heat engines

    Science.gov (United States)

    Salzbrenner, R.

    1984-06-01

    The mechanical shape memory effect associated with a thermoelastic martensitic transformation can be used to convert heat directly into mechanical work. Laboratory simulation of two types of heat engine cycles (Stirling and Ericsson) has been performed to measure the amount of work available/cycle in a Ni-45 at. pct Ti alloy. Tensile deformations at ambient temperature induced martensite, while a subsequent increase in temperature caused a reversion to the parent phase during which a load was carried through the strain recovery (i.e., work was accomplished). The amount of heat necessary to carry the engines through a cycle was estimated from calorimeter measurements and the work performed/cycle. The measured efficiency of the system tested reached a maximum of 1.4 percent, which was well below the theoretical (Carnot) maximum efficiency of 35.6 percent.

  12. Nuclear process heat

    Energy Technology Data Exchange (ETDEWEB)

    Schulten, R [Kernforschungsanlage Juelich G.m.b.H. (F.R. Germany). Inst. fuer Reaktorentwicklung

    1976-05-01

    It is anticipated that the coupled utilization of coal and nuclear energy will achieve great importance in the future, the coal serving mainly as raw material and nuclear energy more as primary energy. Prerequisite for this development is the availability of high-temperature reactors, the state of development of which is described here. Raw materials for coupled use with nuclear process heat are petroleum, natural gas, coal, lignite, and water. Steam reformers heated by nuclear process heat, which are suitable for numerous processes, are expected to find wide application. The article describes several individual methods, all based on the transport of gas in pipelines, which could be utilized for the long distance transport of 'nuclear energy'.

  13. Geothermal heat pump

    International Nuclear Information System (INIS)

    Bruno, R.; Tinti, F.

    2009-01-01

    In recent years, for several types of buildings and users, the choice of conditioning by heat pump and low enthalpy geothermal reservoir has been increasing in the Italian market. In fact, such systems are efficient in terms of energy and consumption, they can perform, even at the same time, both functions, heating and cooling and they are environmentally friendly, because they do not produce local emissions. This article will introduce the technology and will focus on critical points of a geothermal field design, from actual practice, to future perspectives for the geo exchanger improvement. Finally, the article presents a best practice case in Bologna district, with an economic analysis showing the convenience of a geothermal heat pump. Conclusions of the real benefits of these plants can be drawn: compared to a non-negligible initial cost, the investment has a pay-back period almost always acceptable, usually less than 10 years. [it

  14. Large Scale Solar Heating

    DEFF Research Database (Denmark)

    Heller, Alfred

    2001-01-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

  15. District heating in Flensburg

    Energy Technology Data Exchange (ETDEWEB)

    Prinz, W.

    1981-01-01

    The majority of our population, but also of our authorities, are still skeptical or even disapproving towards district heating. The reasons of this negative attitude are partly psychological - e.g. the individualism of the Swiss and their dislike for too centralised structures and ''forced connections'' - but also the existence of finished gas supply networks and the fear of considerable pre-investments and torn streets over years. The following article - held as a speech on the information meeting ''District heating and the possible contribution of nuclear energy'' organised by the Swiss Association for Atomic Energy in Bern shows a practical problem solving at the example of the district heating in Flensburg and deals with these questions.

  16. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  17. Heat dispersion in rivers

    International Nuclear Information System (INIS)

    Shaw, T.L.

    1974-01-01

    One of the tasks of the Sonderforschungsbereich 80 is to study the dispersion of heat discharged into rivers and other bodies of water and to develop methods which permit prediction of detrimental effects caused by the heated discharges. In order to help the SFB 80 to specify this task, Dr. Shaw, lecturer of Civil Engineering at the Bristol University, conducted a literature survey on heat-dispersion studies during the two months which he spent as a visiting research fellow with the SFB 80 at the University of Karlsruhe in the summer of 1973. The following report is the outcome of this survey. It gives Dr. Shaw's assessment of the present state of knowledge - based almost exclusively on literature in the English language - and compares this with the knowledge required by river planners. The apparent discrepancy leads to suggestions for future research. Selected references as well as a representative bibliography can be found at the end of the report. (orig.) [de

  18. RF Pulsed Heating

    Energy Technology Data Exchange (ETDEWEB)

    Pritzkau, David P.

    2002-01-03

    RF pulsed heating is a process by which a metal is heated from magnetic fields on its surface due to high-power pulsed RF. When the thermal stresses induced are larger than the elastic limit, microcracks and surface roughening will occur due to cyclic fatigue. Pulsed heating limits the maximum magnetic field on the surface and through it the maximum achievable accelerating gradient in a normal conducting accelerator structure. An experiment using circularly cylindrical cavities operating in the TE{sub 011} mode at a resonant frequency of 11.424 GHz is designed to study pulsed heating on OFE copper, a material commonly used in normal conducting accelerator structures. The high-power pulsed RF is supplied by an X-band klystron capable of outputting 50 MW, 1.5 {micro}s pulses. The test pieces of the cavity are designed to be removable to allow testing of different materials with different surface preparations. A diagnostic tool is developed to measure the temperature rise in the cavity utilizing the dynamic Q change of the resonant mode due to heating. The diagnostic consists of simultaneously exciting a TE{sub 012} mode to steady-state in the cavity at 18 GHz and measuring the change in reflected power as the cavity is heated from high-power pulsed RF. Two experimental runs were completed. One run was executed at a calculated temperature rise of 120 K for 56 x 10{sup 6} pulses. The second run was executed at a calculated temperature rise of 82 K for 86 x 10{sup 6} pulses. Scanning electron microscope pictures show extensive damage occurring in the region of maximum temperature rise on the surface of the test pieces.

  19. Irreversible Brownian Heat Engine

    Science.gov (United States)

    Taye, Mesfin Asfaw

    2017-10-01

    We model a Brownian heat engine as a Brownian particle that hops in a periodic ratchet potential where the ratchet potential is coupled with a linearly decreasing background temperature. We show that the efficiency of such Brownian heat engine approaches the efficiency of endoreversible engine η =1-√{{Tc/Th}} [23]. On the other hand, the maximum power efficiency of the engine approaches η ^{MAX}=1-({Tc/Th})^{1\\over 4}. It is shown that the optimized efficiency always lies between the efficiency at quasistatic limit and the efficiency at maximum power while the efficiency at maximum power is always less than the optimized efficiency since the fast motion of the particle comes at the expense of the energy cost. If the heat exchange at the boundary of the heat baths is included, we show that such a Brownian heat engine has a higher performance when acting as a refrigerator than when operating as a device subjected to a piecewise constant temperature. The role of time on the performance of the motor is also explored via numerical simulations. Our numerical results depict that the time t and the external load dictate the direction of the particle velocity. Moreover, the performance of the heat engine improves with time. At large t (steady state), the velocity, the efficiency and the coefficient of performance of the refrigerator attain their maximum value. Furthermore, we study the effect of temperature by considering a viscous friction that decreases exponentially as the background temperature increases. Our result depicts that the Brownian particle exhibits a fast unidirectional motion when the viscous friction is temperature dependent than that of constant viscous friction. Moreover, the efficiency of this motor is considerably enhanced when the viscous friction is temperature dependent. On the hand, the motor exhibits a higher performance of the refrigerator when the viscous friction is taken to be constant.

  20. Lowcost automated control for steel heat treatments

    International Nuclear Information System (INIS)

    Zambaldi, Edimilson; Magalhães, Ricardo R.; Barbosa, Bruno H.G.; Silva, Sandro P. da; Ferreira, Danton D.

    2017-01-01

    Highlights: • Control the furnace temperature measured by thermocouple and adjusts it. • Activating the furnace resistors through Pulse Width Modulation. • Appling heat treatments to steels by a low-cost controller. - Abstract: The aim of this paper is to propose a low cost, automated furnace control system for the heat treatment of steel. We used an open source electronic prototyping platform to control the furnace temperature, thus reducing human interaction during the heat process. The platform can be adapted to non-controlled commercial furnaces, which are often used by small businesses. A Proportional-Integral-Derivative (PID) controller was implemented to regulate the furnace temperature based on a defined heat treatment cycle. The embedded system activates the furnace resistors through Pulse Width Modulation (PWM), allowing for control of electrical power supplied to the furnace. Hardening and tempering were performed on standard steel samples using a traditional method (visual inspection without temperature control) as well the embedded system with PID feedback control. The results show that the proposed system can reproduce an arbitrary heat treatment curve with accuracy and provide the desired final hardness as inferred through metallographic analysis. In addition, we observed a 6% saving in energy consumption using the proposed control system. Furthermore, the estimated cost to implement the system is 42% lower than a commercial controller model implemented in commercial furnaces.