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Sample records for adverse thermal environments

  1. Carbon fiber composite characterization in adverse thermal environments.

    SciTech Connect

    Gomez-Vasquez, Sylvia; Brown, Alexander L.; Hubbard, Joshua A.; Ramirez, Ciro J.; Dodd, Amanda B.

    2011-05-01

    The behavior of carbon fiber aircraft composites was studied in adverse thermal environments. The effects of resin composition and fiber orientation were measured in two test configurations: 102 by 127 millimeter (mm) test coupons were irradiated at approximately 22.5 kW/m{sup 2} to measure thermal response, and 102 by 254 mm test coupons were irradiated at approximately 30.7 kW/m{sup 2} to characterize piloted flame spread in the vertically upward direction. Carbon-fiber composite materials with epoxy and bismaleimide resins, and uni-directional and woven fiber orientations, were tested. Bismaleimide samples produced less smoke, and were more resistant to flame spread, as expected for high temperature thermoset resins with characteristically lower heat release rates. All materials lost approximately 20-25% of their mass regardless of resin type, fiber orientation, or test configuration. Woven fiber composites displayed localized smoke jetting whereas uni-directional composites developed cracks parallel to the fibers from which smoke and flames emanated. Swelling and delamination were observed with volumetric expansion on the order of 100% to 200%. The purpose of this work was to provide validation data for SNL's foundational thermal and combustion modeling capabilities.

  2. Thermal Environments.

    ERIC Educational Resources Information Center

    Rutgers, Norman

    The role that a good thermal environment plays in the educational process is discussed. Design implications arise from an analysis of the heating and ventilating principles as apply to vocational-technical facilities. The importance of integrating thermal components in the total design is emphasized. (JS)

  3. Fiber optics in adverse environments

    SciTech Connect

    Lyous, P.B.

    1982-01-01

    Radiation effects in optical fibers are considered, taking into account recent progress in the investigation of radiation resistant optical fibers, radiation damage in optical fibers, radiation-induced transient absorption in optical fibers, X-ray-induced transient attenuation at low temperatures in polymer clad silica (PCS) fibers, optical fiber composition and radiation hardness, the response of irradiated optical waveguides at low temperatures, and the effect of ionizing radiation on fiber-optic waveguides. Other topics explored are related to environmental effects on components of fiber optic systems, and radiation detection systems using optical fibers. Fiber optic systems in adverse environments are also discussed, giving attention to the survivability of Army fiber optics systems, space application of fiber optics systems, fiber optic wavelength multiplexing for civil aviation applications, a new fiber optic data bus topology, fiber optics for aircraft engine/inlet control, and application of fiber optics in high voltage substations.

  4. THERMAL ENVIRONMENT AND LEARNING.

    ERIC Educational Resources Information Center

    LANE, W.R.

    RESEARCH ON THERMAL ENVIRONMENT IN SCHOOLS IS SUMMARIZED AND THE STATUS OF "THERMAL ENVIRONMENT AND LEARNING" RESEARCH COMPLETED AND/OR UNDERWAY IN THE IOWA CENTER FOR RESEARCH IN SCHOOL ADMINISTRATION IS REPORTED. RESULTS ARE--(1) CHILDREN DID LEARN BETTER UNDER MODEL THERMAL CONDITIONS, (2) TEACHERS MUST BECOME MORE AWARE OF THERMAL CONDITIONS,…

  5. SRB thermal environments

    NASA Technical Reports Server (NTRS)

    Crain, W. K.; Knox, E. C.; Frost, C. L.; Engel, C. D.

    1989-01-01

    The objective was to utilize and expand the Solid Rocket Booster (SRB) orbital flight test data base for better predictions of future flight environments. There were five tasks associated with this effort: analyze the internal aft skirt wind tunnel data and incorporate it into a data base for generating design and preflight reeentry thermal environments; generate reentry design thermal environments for the SRB steel case with the nozzle extension off; generate reentry design thermal environments for the SRB Filament Wound Case with the nozzle extension off; develop an engineering tool to analyze the 3-D flowfield around the SRB aft skirt during reentry for the purpose of obtaining the frequency and severity of the belching gas intrusion internal to the aft skirt; and perform SRM transient joint flow analysis for subscale and full scale motor firing as well as determine the effects of debonds of the insulation on the fill time and heating within the field joint insulation. In addition, this work was extended to provide support for the 51L Shuttle SRB failure analysis.

  6. Dynamic thermal environment and thermal comfort.

    PubMed

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research. PMID:26171688

  7. Adverse environments and children's creativity development: transforming the notion of "success in adversity" in China.

    PubMed

    Cheng, Li; Tan, Mei; Liu, Zhengkui

    2015-01-01

    China has been undergoing great social change due to its new focus on urbanization and globalization. Such change has had a tremendous adverse impact on the living conditions of millions of young children, simultaneously generating new interest in children's creativity development. The intersection of these two issues has important implications for China's future as it brings together one of China's core cultural values-"success in adversity"-the importance of creativity, and very real social and economic needs. "Success in adversity" reflects the strongly held belief that individuals who suffer adverse environments can rise to excellence and success through persistence, effort, and creativity. In this article, we briefly explore the historical sources of this belief and how it is closely related to the Chinese conception of creativity. We then present some studies on the creativity of some of China's migrant children. Findings show that while migrant children as a group may not generally exhibit higher creativity than their urban peers as hypothesized, indications of resilience and creative potential suggest that the notion of success in adversity may contribute to the positive development of China's migrant children more substantially when it is informed by research and augmented by research-supported policy. PMID:25732020

  8. Subject recruitment for cancer control studies in an adverse environment.

    PubMed

    Heiney, Sue P; Adams, Swann Arp; Cunningham, Joan E; McKenzie, Wendy; Harmon, Brook; Hebert, James R; Modayil, Mary

    2006-01-01

    Subject recruitment in an adverse environment prompted researchers to identify a novel method to gain a different perspective on the problem. Lewin's Model of Change was used in a post hoc examination of recruitment strategies from 5 cancer control studies of breast or prostate cancer. Based on this evaluation, driving and restraining forces in recruitment were identified. Lessons learned and recommendations are discussed based on this evaluation. Five categories of restrainers were identified from this evaluation and include sociocultural, institutional, individuals, budget, and study design. Conversely, only 3 categories of drivers were elucidated by the examination: sociocultural, institutional, and individuals. Lessons and recommendations ranged from addressing institutional barriers to capitalizing on public relations. Researchers entering a new environment for recruitment would benefit from using Lewin's force field analysis before writing a proposal or implementing a project. This approach better directs energy and resources and enhances the ability of the investigator to maintain a broad, less biased perspective. PMID:16871096

  9. Optimizing the neonatal thermal environment.

    PubMed

    Sherman, Tami Irwin; Greenspan, Jay S; St Clair, Nancy; Touch, Suzanne M; Shaffer, Thomas H

    2006-01-01

    Devices used to maintain thermal stability in preterm infants have advanced over time from the first incubator reported by Jean-Louis-Paul Denuce in 1857 to the latest Versalet Incuwarmer and Giraffe Omnibed devices today. Optimizing the thermal environment has proven significant for improving the chances of survival for small infants. Understanding the basic physiologic principles and current methodology of thermoregulation is important in the clinical care of these tiny infants. This article highlights principles of thermoregulation and the technologic advances that provide thermal support to our vulnerable PMID:16913236

  10. Pressure Ratio to Thermal Environments

    NASA Technical Reports Server (NTRS)

    Lopez, Pedro; Wang, Winston

    2012-01-01

    A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

  11. Cellulolytic Microorganisms from Thermal Environments

    SciTech Connect

    Vishnivetskaya, Tatiana A; Raman, Babu; Phelps, Tommy Joe; Podar, Mircea; Elkins, James G

    2012-01-01

    Thermal, anaerobic environments rich in decaying plant material are a potential source of novel cellulolytic bacteria. Samples collected from geothermal aquifers in the Yellowstone National Park (YNP) were used to select for cellulolytic thermophiles. Laboratory enrichments on dilute-acid pretreated plant biomass (switchgrass, Populus), and crystalline cellulose (Avicel) resulted in the isolation of 247 environmental clones. The majority of individual clones were affiliated with the cellulolytic bacteria of phylum Firmicutes, followed by xylanolytic and saccharolytic members of the phylum Dictyoglomi. Among the Firmicutes, the clones were affiliated with the genera Caldicellulosiruptor (54.4%), Caloramator (11.5%), Thermoanaerobacter (8.8%), Thermovenabulum (4.1%), and Clostridium (2.0%). From established anaerobic thermophilic enrichments a total of 81 single strains of the genera Caldicellulosiruptor (57%) and Thermoanaerobacter (43%) were isolated. With continuous flow enrichment on Avicel, increases in the relative abundance of Caloramator sp. was observed over clones detected from the Caldicellulosiruptor. Complex communities of interacting microorganisms bring about cellulose decomposition in nature, therefore using up-to-date approaches may yield novel cellulolytic microorganisms with high activity and a rapid rate of biomass conversion to biofuels.

  12. Thermal Dose and the Probability of Adverse Effects from HIFU

    NASA Astrophysics Data System (ADS)

    Church, Charles C.

    2007-05-01

    The absorption of high-intensity, focused ultrasound (HIFU) by the body results in brief, intense heating capable of killing cells, tissues or entire organisms, thereby providing the basis for many applications in medical therapy. The object of such therapy is in assuring the destruction of diseased tissue while sparing adjacent, healthy tissue. However, even moderate heating to a few degrees above normal physiological temperatures can perturb biological systems, e.g., by altering normal metabolic processes. In modeling the bioeffects produced by ultrasound-induced heating, the physicist typically relies on bulk tissue properties and ultrasound exposure parameters to calculate the thermal `dose' delivered to the tissue. Although thermal dose is currently given in units of time rather than energy, the concept is quite useful, and its use in quantifying the probability and extent of biological effects expected from therapeutic exposures is demonstrated. The results demonstrate the need for additional experimental data to validate and advance existing theoretical approaches for HIFU exposures.

  13. Simple Thermal Environment Model (STEM) User's Guide

    NASA Technical Reports Server (NTRS)

    Justus, C.G.; Batts, G. W.; Anderson, B. J.; James, B. F.

    2001-01-01

    This report presents a Simple Thermal Environment Model (STEM) for determining appropriate engineering design values to specify the thermal environment of Earth-orbiting satellites. The thermal environment of a satellite, consists of three components: (1) direct solar radiation, (2) Earth-atmosphere reflected shortwave radiation, as characterized by Earth's albedo, and (3) Earth-atmosphere-emitted outgoing longwave radiation (OLR). This report, together with a companion "guidelines" report provides methodology and guidelines for selecting "design points" for thermal environment parameters for satellites and spacecraft systems. The methods and models reported here are outgrowths of Earth Radiation Budget Experiment (ERBE) satellite data analysis and thermal environment specifications discussed by Anderson and Smith (1994). In large part, this report is intended to update (and supersede) those results.

  14. CVD diamond as an optical material for adverse environments

    NASA Astrophysics Data System (ADS)

    Snail, Keith A.

    A status report is presented on the obstacles and current research related to using CVD diamond as an optical material. Problems discussed include properties of CVD carbon deposits, including structure, thermal conductivity and oxidation resistance, which are relevant to the optical uses of diamond; absorption coefficient measurements on CVD diamond in the visible and IR; and a review of various aspects of the synthesis of CVD diamond, including the growth of transparent and translucent diamond, efforts to grow diamond at low substrate temperatures, and approches to reducing the optical scatter of as grown polycrystalline diamond films and windows. Particular attention is given to techniques for reducing optical scatter which involve modifying materials morphologies during the growth process by controlling nucleation density, renucleaton frequency, and/or the orientation of crystal faces at film surfaces; techniques for postdeposition polishing of the surface of CVD diamond films and windows; and optical applications for CVD diamond.

  15. CVD diamond as an optical material for adverse environments

    NASA Astrophysics Data System (ADS)

    Snail, Keith A.

    1991-01-01

    A status report is presented on the obstacles and current research related to using CVD diamond as an optical material. Problems discussed include properties of CVD carbon deposits, including structure, thermal conductivity and oxidation resistance, which are relevant to the optical uses of diamond; absorption coefficient measurements on CVD diamond in the visible and IR; and a review of various aspects of the synthesis of CVD diamond, including the growth of transparent and translucent diamond, efforts to grow diamond at low substrate temperatures, and approches to reducing the optical scatter of as grown polycrystalline diamond films and windows. Particular attention is given to techniques for reducing optical scatter which involve modifying materials morphologies during the growth process by controlling nucleation density, renucleaton frequency, and/or the orientation of crystal faces at film surfaces; techniques for postdeposition polishing of the surface of CVD diamond films and windows; and optical applications for CVD diamond.

  16. Early Adverse Environments and Genetic Influences on Age at First Sex: Evidence for Gene × Environment Interaction

    ERIC Educational Resources Information Center

    Carlson, Marie D.; Mendle, Jane; Harden, K. Paige

    2014-01-01

    Youth who experience adverse environments in early life initiate sexual activity at a younger age, on average, than those from more advantaged circumstances. Evolutionary theorists have posited that ecological stress precipitates earlier reproductive and sexual onset, but it is unclear how stressful environments interact with genetic influences on…

  17. Quantum Two Player Game in Thermal Environment

    PubMed Central

    Dajka, Jerzy; Kłoda, Dawid; Łobejko, Marcin; Sładkowski, Jan

    2015-01-01

    A two-player quantum game is considered in the presence of thermal decoherence. It is shown how the thermal environment modeled in terms of rigorous Davies approach affects payoffs of the players. The conditions for either beneficial or pernicious effect of decoherence are identified. The general considerations are exemplified by the quantum version of Prisoner Dilemma. PMID:26322833

  18. Quantum cloning disturbed by thermal Davies environment

    NASA Astrophysics Data System (ADS)

    Dajka, Jerzy; Łuczka, Jerzy

    2016-03-01

    A network of quantum gates designed to implement universal quantum cloning machine is studied. We analyze how thermal environment coupled to auxiliary qubits, `blank paper' and `toner' required at the preparation stage of copying, modifies an output fidelity of the cloner. Thermal environment is described in terms of the Markovian Davies theory. We show that such a cloning machine is not universal any more but its output is independent of at least a part of parameters of the environment. As a case study, we consider cloning of states in a six-state cryptography's protocol. We also briefly discuss cloning of arbitrary input states.

  19. Quantum cloning disturbed by thermal Davies environment

    NASA Astrophysics Data System (ADS)

    Dajka, Jerzy; Łuczka, Jerzy

    2016-06-01

    A network of quantum gates designed to implement universal quantum cloning machine is studied. We analyze how thermal environment coupled to auxiliary qubits, `blank paper' and `toner' required at the preparation stage of copying, modifies an output fidelity of the cloner. Thermal environment is described in terms of the Markovian Davies theory. We show that such a cloning machine is not universal any more but its output is independent of at least a part of parameters of the environment. As a case study, we consider cloning of states in a six-state cryptography's protocol. We also briefly discuss cloning of arbitrary input states.

  20. The long-term impact of adverse caregiving environments on epigenetic modifications and telomeres

    PubMed Central

    Blaze, Jennifer; Asok, Arun; Roth, Tania L.

    2015-01-01

    Early childhood is a sensitive period in which infant-caregiver experiences have profound effects on brain development and behavior. Clinical studies have demonstrated that infants who experience stress and adversity in the context of caregiving are at an increased risk for the development of psychiatric disorders. Animal models have helped to elucidate some molecular substrates of these risk factors, but a complete picture of the biological basis remains unknown. Studies continue to indicate that environmentally-driven epigenetic modifications may be an important mediator between adverse caregiving environments and psychopathology. Epigenetic modifications such as DNA methylation, which normally represses gene transcription, and microRNA processing, which interferes with both transcription and translation, show long-term changes throughout the brain and body following adverse caregiving. Recent evidence has also shown that telomeres (TTAGGG nucleotide repeats that cap the ends of DNA) exhibit long-term changes in the brain and in the periphery following exposure to adverse caregiving environments. Interestingly, telomeric enzymes and subtelomeric regions are subject to epigenetic modifications—a factor which may play an important role in regulating telomere length and contribute to future mental health. This review will focus on clinical and animal studies that highlight the long-term epigenetic and telomeric changes produced by adverse caregiving in early-life. PMID:25904853

  1. Predicting human thermal comfort in a transient nonuniform thermal environment.

    PubMed

    Rugh, J P; Farrington, R B; Bharathan, D; Vlahinos, A; Burke, R; Huizenga, C; Zhang, H

    2004-09-01

    The National Renewable Energy Laboratory has developed a suite of thermal comfort tools to assist in the development of smaller and more efficient climate control systems in automobiles. These tools, which include a 126-segment sweating manikin, a finite element physiological model of the human body, and a psychological model based on human testing, are designed to predict human thermal comfort in transient, nonuniform thermal environments, such as automobiles. The manikin measures the heat loss from the human body in the vehicle environment and sends the heat flux from each segment to the physiological model. The physiological model predicts the body's response to the environment, determines 126-segment skin temperatures, sweat rate, and breathing rate, and transmits the data to the manikin. The psychological model uses temperature data from the physiological model to predict the local and global thermal comfort as a function of local skin and core temperatures and their rates of change. Results of initial integration testing show the thermal response of a manikin segment to transient environmental conditions. PMID:15221399

  2. Natural selection on thermal performance in a novel thermal environment

    PubMed Central

    Logan, Michael L.; Cox, Robert M.; Calsbeek, Ryan

    2014-01-01

    Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation to changing conditions. Here, we mimic the effects of climate change by experimentally transplanting a population of Anolis sagrei lizards to a novel thermal environment. Transplanted lizards experienced warmer and more thermally variable conditions, which resulted in strong directional selection on thermal performance traits. These same traits were not under selection in a reference population studied in a less thermally stressful environment. Our results indicate that climate change can exert strong natural selection on tropical ectotherms, despite their ability to thermoregulate behaviorally. To the extent that thermal performance traits are heritable, populations may be capable of rapid adaptation to anthropogenic warming. PMID:25225361

  3. Natural selection on thermal performance in a novel thermal environment.

    PubMed

    Logan, Michael L; Cox, Robert M; Calsbeek, Ryan

    2014-09-30

    Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation to changing conditions. Here, we mimic the effects of climate change by experimentally transplanting a population of Anolis sagrei lizards to a novel thermal environment. Transplanted lizards experienced warmer and more thermally variable conditions, which resulted in strong directional selection on thermal performance traits. These same traits were not under selection in a reference population studied in a less thermally stressful environment. Our results indicate that climate change can exert strong natural selection on tropical ectotherms, despite their ability to thermoregulate behaviorally. To the extent that thermal performance traits are heritable, populations may be capable of rapid adaptation to anthropogenic warming. PMID:25225361

  4. Direct numerical simulations of turbulent thermal boundary layers subjected to adverse streamwise pressure gradients

    NASA Astrophysics Data System (ADS)

    Araya, Guillermo; Castillo, Luciano

    2013-09-01

    An innovative method for prescribing turbulent thermal inflow information in spatially developing boundary layers under streamwise pressure gradients is introduced for attached flows. The approach is tested and validated in a suite of Direct Numerical Simulations (DNS) of thermal boundary layers for zero (ZPG) and adverse (APG) pressure gradients with momentum thickness Reynolds numbers (Reθ) up to 3000. The turbulent thermal data are generated based on the dynamic multi-scale approach proposed by Araya et al. ["A dynamic multi-scale approach for turbulent inflow boundary conditions in spatially evolving flows," J. Fluid Mech. 670, 581-605 (2011)], which is extended to include thermal field simulations in the present article. The approach is based on the original rescaling-recycling method developed by Lund, Wu, and Squires ["Generation of turbulent inflow data for spatially developing boundary layer simulations," J. Comput. Phys. 140, 233-258 (1998)] for ZPG flows. Isothermal walls are considered for the thermal field and the molecular Prandtl number is 0.71. In addition, only inlet momentum/thermal boundary layer thicknesses must be prescribed while other flow parameters such as the inlet friction velocity, uτ, and friction temperature, Θτ, are computed dynamically based on the flow solution obtained downstream by means of a test plane. This plane is located between the inlet and recycle stations. Based on the unique and extensive DNS results of heat transfer obtained in this investigation, the effects of Reynolds numbers and adverse pressure gradients on the flow and thermal parameters are also explored and visualized. The principal outcome of adverse pressure gradient on the flow parameters has been determined as a secondary peak, particularly on the streamwise velocity fluctuations in the outer region, which shows clear evidence of energy production in the outer flow and not only in the buffer layer as traditionally known. Nevertheless, this peak is not so

  5. Epigenetics and life-long consequences of an adverse nutritional and diabetic intrauterine environment

    PubMed Central

    El Hajj, Nady; Schneider, Eberhard; Lehnen, Harald; Haaf, Thomas

    2014-01-01

    The phenomenon that adverse environmental exposures in early life are associated with increased susceptibilities for many adult, particularly metabolic diseases, is now referred to as ‘developmental origins of health and disease (DOHAD)’ or ‘Barker’ hypothesis. Fetal overnutrition and undernutrition have similar long-lasting effects on the setting of the neuroendocrine control systems, energy homeostasis, and metabolism, leading to life-long increased morbidity. There are sensitive time windows during early development, where environmental cues can program persistent epigenetic modifications which are generally assumed to mediate these gene–environment interactions. Most of our current knowledge on fetal programing comes from animal models and epidemiological studies in humans, in particular the Dutch famine birth cohort. In industrialized countries, there is more concern about adverse long-term consequences of fetal overnutrition, i.e. by exposure to gestational diabetes mellitus and/or maternal obesity which affect 10–20% of pregnancies. Epigenetic changes due to maternal diabetes/obesity may predispose the offspring to develop metabolic disease later in life and, thus, transmit the adverse environmental exposure to the next generation. This vicious cycle could contribute significantly to the worldwide metabolic disease epidemics. In this review article, we focus on the epigenetics of an adverse intrauterine environment, in particular gestational diabetes, and its implications for the prevention of complex disease. PMID:25187623

  6. Epigenetics and life-long consequences of an adverse nutritional and diabetic intrauterine environment.

    PubMed

    El Hajj, Nady; Schneider, Eberhard; Lehnen, Harald; Haaf, Thomas

    2014-12-01

    The phenomenon that adverse environmental exposures in early life are associated with increased susceptibilities for many adult, particularly metabolic diseases, is now referred to as 'developmental origins of health and disease (DOHAD)' or 'Barker' hypothesis. Fetal overnutrition and undernutrition have similar long-lasting effects on the setting of the neuroendocrine control systems, energy homeostasis, and metabolism, leading to life-long increased morbidity. There are sensitive time windows during early development, where environmental cues can program persistent epigenetic modifications which are generally assumed to mediate these gene-environment interactions. Most of our current knowledge on fetal programing comes from animal models and epidemiological studies in humans, in particular the Dutch famine birth cohort. In industrialized countries, there is more concern about adverse long-term consequences of fetal overnutrition, i.e. by exposure to gestational diabetes mellitus and/or maternal obesity which affect 10-20% of pregnancies. Epigenetic changes due to maternal diabetes/obesity may predispose the offspring to develop metabolic disease later in life and, thus, transmit the adverse environmental exposure to the next generation. This vicious cycle could contribute significantly to the worldwide metabolic disease epidemics. In this review article, we focus on the epigenetics of an adverse intrauterine environment, in particular gestational diabetes, and its implications for the prevention of complex disease. PMID:25187623

  7. Cognitive adaptations to stressful environments: When childhood adversity enhances adult executive function.

    PubMed

    Mittal, Chiraag; Griskevicius, Vladas; Simpson, Jeffry A; Sung, Sooyeon; Young, Ethan S

    2015-10-01

    Can growing up in a stressful childhood environment enhance certain cognitive functions? Drawing participants from higher-income and lower-income backgrounds, we tested how adults who grew up in harsh or unpredictable environments fared on 2 types of executive function tasks: inhibition and shifting. People who experienced unpredictable childhoods performed worse at inhibition (overriding dominant responses), but performed better at shifting (efficiently switching between different tasks). This finding is consistent with the notion that shifting, but not inhibition, is especially useful in unpredictable environments. Importantly, differences in executive function between people who experienced unpredictable versus predictable childhoods emerged only when they were tested in uncertain contexts. This catalyst suggests that some individual differences related to early life experience are manifested under conditions of uncertainty in adulthood. Viewed as a whole, these findings indicate that adverse childhood environments do not universally impair mental functioning, but can actually enhance specific types of cognitive performance in the face of uncertainty. PMID:26414842

  8. Adverse Environments and Children's Creativity Development: Transforming the Notion of "Success in Adversity" in China

    ERIC Educational Resources Information Center

    Cheng, Li; Tan, Mei; Liu, Zhengkui

    2015-01-01

    China has been undergoing great social change due to its new focus on urbanization and globalization. Such change has had a tremendous adverse impact on the living conditions of millions of young children, simultaneously generating new interest in children's creativity development. The intersection of these two issues has important…

  9. Electrical stimulation vs thermal effects in a complex electromagnetic environment.

    PubMed

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Sánchez, Miguel

    2009-08-01

    Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10(-4)) than that based on thermal considerations (exposure quotient 0.16 10(-4)). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects. PMID:19481236

  10. Adverse human health effects associated with molds in the indoor environment.

    PubMed

    Hardin, Bryan D; Kelman, Bruce J; Saxon, Andrew

    2003-05-01

    Molds are common and important allergens. About 5% of individuals are predicted to have some allergic airway symptoms from molds over their lifetime. However, it should be remembered that molds are not dominant allergens and that the outdoor molds, rather than indoor ones, are the most important. For almost all allergic individuals, the reactions will be limited to rhinitis or asthma; sinusitis may occur secondarily due to obstruction. Rarely do sensitized individuals develop uncommon conditions such as ABPA or AFS. To reduce the risk of developing or exacerbating allergies, mold should not be allowed to grow unchecked indoors. When mold colonization is discovered in the home, school, or office, it should be remediated after the source of the moisture that supports its growth is identified and eliminated. Authoritative guidelines for mold remediation are available. Fungi are rarely significant pathogens for humans. Superficial fungal infections of the skin and nails are relatively common in normal individuals, but those infections are readily treated and generally resolve without complication. Fungal infections of deeper tissues are rare and in general are limited to persons with severely impaired immune systems. The leading pathogenic fungi for persons with nonimpaired immune function, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma, may find their way indoors with outdoor air but normally do not grow or propagate indoors. Due to the ubiquity of fungi in the environment, it is not possible to prevent immunecompromised individuals from being exposed to molds and fungi outside the confines of hospital isolation units. Some molds that propagate indoors may under some conditions produce mycotoxins that can adversely affect living cells and organisms by a variety of mechanisms. Adverse effects of molds and mycotoxins have been recognized for centuries following ingestion of contaminated foods. Occupational diseases are also recognized in association with

  11. Drosophila larvae: Thermal ecology in changing environments

    NASA Astrophysics Data System (ADS)

    Wang, George

    Temperature affects almost all aspects of life. Although much work has been done to assess the impact of temperature on organismal performance, relatively little is known about how organisms behaviorally regulate temperature, how these behaviors effect population fitness, or how changing climate may interact with these behaviors. I explore these questions with the model system Drosophila larvae. Larvae are small, with a low thermal mass and limited capacity for physiological thermoregulation. Mortality is generally high in larvae, with large potential impacts on population growth rate. Thus behavioral thermoregulation in larvae should be of critical selective importance. I present a review of the current knowledge of Drosophila thermal preference. I describe quantifiable thermoregulatory behaviors ( TMV and TW) unique to larvae. I show interspecific variation of these behaviors in Drosophila melanogaster and several close relatives, and intraspecific variation between populations collected from different environments. I also investigate these behaviors in two mutant lines, ssa and biz, to investigate the genetic basis of these behaviors. I show that larval thermoregulatory systems are independent of those of adults. Further these thermoregulatory behaviors differ between two sister species, D. yakuba and D. santomea. Although these two species readily hybridize in laboratory conditions, very few hybrids are observed in the field. The surprising result that hybrids of D. yakuba and D. santomea seem to inherit TMV from D. yakuba suggests a novel extrinsic isolation mechanism between the two species. I explore how fitness is the result of the interaction between genetics and the environment. I utilize Monte Carlo simulation to show how non-linear norms of reaction generate variation in populations even in the absence of behavior or epigenetic evolutionary mechanisms. Finally I investigate the global distribution of temperatures in which these organisms exist using

  12. The association of current and sustained area-based adverse socioeconomic environment with physical inactivity.

    PubMed

    Pascual, Cruz; Regidor, Enrique; Astasio, Paloma; Ortega, Paloma; Navarro, Pedro; Domínguez, Vicente

    2007-08-01

    This paper evaluates the association between socioeconomic environment in the province of residence and physical inactivity, using measures of current and sustained area-based adverse socioeconomic environment. The analysis included 19,324 individuals representative of the Spanish non-institutionalised population aged 16-74 years. The measure of association estimated was the prevalence odds ratio for physical inactivity by current gross domestic product per capita (GDPpc) and current Gini coefficient, and by number of times each province has had a low GDPpc and number of times each province has had a high Gini coefficient in the last two decades. After adjusting for age, individual socioeconomic characteristics, and number of sports facilities per 1,000 population, the odds ratio for physical inactivity in residents of provinces with the lowest current GDPpc versus those with the highest was 1.64 in men and 2.01 in women. The odds ratio in residents of provinces that had always been among those with the lowest GDPpc versus residents in provinces that had never been among those with lowest GDPpc was 1.54 in men and 1.91 in women. Neither the current Gini coefficient nor the indicator that reflects sustained high Gini coefficient were associated with physical inactivity. These findings show that physical inactivity is associated with current socioeconomic context and with the duration of exposure of the area of residence to adverse socioeconomic circumstances when the indicators of socioeconomic environment are based on GDPpc, but not on income inequality. Also, this association is not explained by individual socioeconomic characteristics or the number of sports facilities. PMID:17466424

  13. The thermal environment of Cascadia Basin

    NASA Astrophysics Data System (ADS)

    Johnson, H. Paul; Hautala, Susan L.; Bjorklund, Tor A.

    2012-07-01

    Located adjacent to the NE Pacific convergent boundary, Cascadia Basin has a global impact well beyond its small geographic size. Composed of young oceanic crust formed at the Juan de Fuca Ridge, igneous rocks underlying the basin are partially insulated from cooling of their initial heat of formation by a thick layer of pelagic and turbidite sediments derived from the adjacent North American margin. The igneous seafloor is eventually consumed at the Cascadia subduction zone, where interactions between the approaching oceanic crust and the North American continental margin are partially controlled by the thermal environment. Within Cascadia Basin, basement topographic relief varies dramatically, and sediments have a wide range of thickness and physical properties. This variation produces regional differences in heat flow and basement temperatures for seafloor even of similar age. Previous studies proposed a north-south thermal gradient within Cascadia Basin, with high geothermal flux and crustal temperatures measured in the heavily sedimented northern portion near Vancouver Island and lower than average heat flux and basement temperatures predicted for the central and southern portions of the basin. If confirmed, this prediction has implications for processes associated with the Cascadia subduction zone, including the location of the "locked zone" of the megathrust fault. Although existing archival geophysical data in the central and southern basin are sparse, nonuniformly distributed, and derived from a wide range of historical sources, a substantial N-S geothermal gradient appears to be confirmed by our present compilation of combined water column and heat flow measurements.

  14. Palatable cafeteria diet ameliorates anxiety and depression-like symptoms following an adverse early environment.

    PubMed

    Maniam, Jayanthi; Morris, Margaret J

    2010-06-01

    Early trauma contributes to psychosocial disorders later in life. An adverse early environment induced by maternal separation (MS) is known to alter behavioural and stress responses in rats. Palatable food dampens stress responses. We investigated the influence of palatable cafeteria high-fat diet (HFD) on behavioural responses following MS or non-handling (NH), versus 15min brief separation. After littering, Sprague-Dawley rats were exposed to short separation, S15 (15min), prolonged separation, S180 (180min) daily from postnatal days 2 to 14 or were non-handled. Pups were assigned to HFD or chow at weaning. We assessed depression and anxiety-like behaviour with sucrose preference test (SPT) and elevated plus maze (EPM) respectively, and measured hypothalamic CRH and hippocampal glucocorticoid receptor (GR) expression. S180 rats showed increased anxiety-and depression-like behaviours, with increased plasma corticosterone, hypothalamic CRH, and reduced hippocampal GR expression versus S15 rats. Similar effects were observed across gender. These were normalized by provision of HFD, with greater beneficial effects in males. S15 showed no benefit of HFD. NH female rats had less adverse impacts; HFD had beneficial impact on behaviour in NH males. Thus behavioural deficits and gene expression changes induced by early life stress were ameliorated by HFD. These results highlight the important place of palatable food in reducing central stress responses supporting the therapeutic value of 'comfort food'. PMID:19939573

  15. Diagnostic criteria for adverse health effects in the environs of wind turbines.

    PubMed

    McMurtry, Robert Y; Krogh, Carmen Me

    2014-10-01

    In an effort to address climate change, governments have pursued policies that seek to reduce greenhouse gases. Alternative energy, including wind power, has been proposed by some as the preferred approach. Few would debate the need to reduce air pollution, but the means of achieving this reduction is important not only for efficiency but also for health protection. The topic of adverse health effects in the environs of industrial wind turbines (AHE/IWT) has proven to be controversial and can present physicians with challenges regarding the management of an exposure to IWT. Rural physicians in particular must be aware of the possibility of people presenting to their practices with a variety of sometimes confusing complaints. An earlier version of the diagnostic criteria for AHE/IWT was published in August 2011. A revised case definition and a model for a study to establish a confirmed diagnosis is proposed. PMID:25383200

  16. Diagnostic criteria for adverse health effects in the environs of wind turbines

    PubMed Central

    Krogh, Carmen ME

    2014-01-01

    Summary In an effort to address climate change, governments have pursued policies that seek to reduce greenhouse gases. Alternative energy, including wind power, has been proposed by some as the preferred approach. Few would debate the need to reduce air pollution, but the means of achieving this reduction is important not only for efficiency but also for health protection. The topic of adverse health effects in the environs of industrial wind turbines (AHE/IWT) has proven to be controversial and can present physicians with challenges regarding the management of an exposure to IWT. Rural physicians in particular must be aware of the possibility of people presenting to their practices with a variety of sometimes confusing complaints. An earlier version of the diagnostic criteria for AHE/IWT was published in August 2011. A revised case definition and a model for a study to establish a confirmed diagnosis is proposed. PMID:25383200

  17. Early Life in a Barren Environment Adversely Affects Spatial Cognition in Laying Hens (Gallus gallus domesticus)

    PubMed Central

    Tahamtani, Fernanda M.; Nordgreen, Janicke; Nordquist, Rebecca E.; Janczak, Andrew M.

    2015-01-01

    Spatial cognition in vertebrates is adversely affected by a lack of environmental complexity during early life. However, to our knowledge, no previous studies have tested the effect of early exposure to varying degrees of environmental complexity on specific components of spatial cognition in chickens. There are two main rearing systems for laying hens in the EU: aviaries and cages. These two systems differ from one another in environmental complexity. The aim of the present study was to test the hypothesis that rearing in a barren cage environment relative to a complex aviary environment causes long-lasting deficits in the ability to perform spatial tasks. For this purpose, 24 white Dekalb laying hens, half of which had been reared in an aviary system and the other half in a conventional cage system, were tested in a holeboard task. Birds from both treatment groups learnt the task; however, the cage-reared hens required more time to locate rewards and had poorer levels of working memory. The latter finding supports the hypothesis that rearing in a barren environment causes long-term impairment of short-term memory in chickens. PMID:26664932

  18. Thermal Environment in School Facilities. A Selected and Annotated Bibliography.

    ERIC Educational Resources Information Center

    Hartman, Robert R.

    Contains a selected and annotated listing of source material concerning the thermal environment in school facilities. It is directed toward the school planner, architect, or administrator concerned with developing a more functional classroom environment. Topical coverage includes--(1) The Thermal Environment and Learning, (2) Physiological Factors…

  19. KCTD8 Gene and Brain Growth in Adverse Intrauterine Environment: A Genome-wide Association Study

    PubMed Central

    Bernard, Manon; Chakravarty, M. Mallar; Davey Smith, George; Gillis, Jesse; Lourdusamy, Anbarasu; Melka, Melkaye G.; Leonard, Gabriel; Pavlidis, Paul; Perron, Michel; Pike, G. Bruce; Richer, Louis; Schumann, Gunter; Timpson, Nicholas; Toro, Roberto; Veillette, Suzanne; Pausova, Zdenka

    2012-01-01

    The most dramatic growth of the human brain occurs in utero and during the first 2 years of postnatal life. Genesis of the cerebral cortex involves cell proliferation, migration, and apoptosis, all of which may be influenced by prenatal environment. Here, we show that variation in KCTD8 (potassium channel tetramerization domain 8) is associated with brain size in female adolescents (rs716890, P = 5.40 × 10−09). Furthermore, we found that the KCTD8 locus interacts with prenatal exposure to maternal cigarette smoking vis-à-vis cortical area and cortical folding: In exposed girls only, the KCTD8 locus explains up to 21% of variance. Using head circumference as a proxy of brain size at 7 years of age, we have replicated this gene–environment interaction in an independent sample. We speculate that KCTD8 might modulate adverse effects of smoking during pregnancy on brain development via apoptosis triggered by low intracellular levels of potassium, possibly reducing the number of progenitor cells. PMID:22156575

  20. KCTD8 gene and brain growth in adverse intrauterine environment: a genome-wide association study.

    PubMed

    Paus, Tomás; Bernard, Manon; Chakravarty, M Mallar; Davey Smith, George; Gillis, Jesse; Lourdusamy, Anbarasu; Melka, Melkaye G; Leonard, Gabriel; Pavlidis, Paul; Perron, Michel; Pike, G Bruce; Richer, Louis; Schumann, Gunter; Timpson, Nicholas; Toro, Roberto; Veillette, Suzanne; Pausova, Zdenka

    2012-11-01

    The most dramatic growth of the human brain occurs in utero and during the first 2 years of postnatal life. Genesis of the cerebral cortex involves cell proliferation, migration, and apoptosis, all of which may be influenced by prenatal environment. Here, we show that variation in KCTD8 (potassium channel tetramerization domain 8) is associated with brain size in female adolescents (rs716890, P = 5.40 × 10(-09)). Furthermore, we found that the KCTD8 locus interacts with prenatal exposure to maternal cigarette smoking vis-à-vis cortical area and cortical folding: In exposed girls only, the KCTD8 locus explains up to 21% of variance. Using head circumference as a proxy of brain size at 7 years of age, we have replicated this gene-environment interaction in an independent sample. We speculate that KCTD8 might modulate adverse effects of smoking during pregnancy on brain development via apoptosis triggered by low intracellular levels of potassium, possibly reducing the number of progenitor cells. PMID:22156575

  1. Light in Thermal Environments (LITE) Workshop

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Light emitted from high temperature black smokers (350 C) at mid-ocean ridge spreading centers has been documented, but the source of this light and its photochemical and biological consequences have yet to be investigated. Preliminary studies indicate that thermal radiation alone might account for the 'glow' and that a novel photoreceptor in shrimp colonizing black smoker chimneys may detect this 'glow.' A more controversial question is whether there may be sufficient photon flux of appropriate wavelengths to support geothermally-driven photosynthesis (GDP) by microorganisms. Although only a very low level of visible and near infrared light may be emitted from any single hydrothermal vent, several aspects of the light make it of more than enigmatic interest. First, the light is clearly linked to geophysical (and perhaps geochemical) processes; its attributes may serve as powerful index parameters for monitoring change in these processes. Second, while the glow at a vent orifice is a very local phenomenon, more expansive subsurface environments may be illuminated, thereby increasing the spatial scale at which biological consequences of this light might be considered. Third, in contrast to intermittent bioluminescent light sources in the deep sea, the light emitted at vents almost certainly glows or flickers continuously over the life of the individual black smokers (years to decades); collectively, light emitted from black smokers along the ocean's spreading centers superimposed on background Cerenkov radiation negates the concept of the deep sea as an environment devoid of abiotic light. Finally, the history of hydrothermal activity predates the origin of life; light in the deep sea has been a continuous phenomenon on a geological time scale and may have served either as a seed or refugium for the evolution of biological photochemical reactions or adaptations.

  2. [Maternal effect obscures adaptation to adverse environments and hinders divergence in Drosophila melanogaster].

    PubMed

    Markov, A V; Ivnitsky, S B; Kornilova, M B; Naimark, E B; Shirokova, N G; Perfilieva, K S

    2015-01-01

    Adaptation to contrasting environments can facilitate ecological divergence and sympatric speciation. Factors that influence the probability and tempo of these processes are poorly known. We performed an evolutionary experiment on Drosophila melanogaster in order to attain better understanding of adaptation dynamics and to model the initial steps of sympatric speciation. In our experiment, several populations are being cultured either on standard rich medium (RM) or on nutrient-deficient starch-based medium (SM). After 10 generations, experimental populations demonstrated unexpected changes in their fitness: on the starch medium, flies grown on RM (FRM) outcompeted those that were cultured on SM (FSM), while on the rich medium, FRM were outcompeted by FSM. That is, experimental populations demonstrated higher fitness on the foreign medium, but were outcompeted by the aliens on the one they had been accustomed to. To explain the paradox, we hypothesize that the observed low fitness of FSM on SM was due to maternal effect, or the "effect of starving mother". The FSM flies are probably better adapted to SM, but the phenotypic outcome of their adaptations is obscured because the females grown on the poor medium invest less in their offspring (for instance, they may produce nutrient-deficient eggs). Larvae hatched from such eggs develop successfully on the rich medium RM, but experience delayed growth and/or lower survival rate on the nutrient-deficient medium SM. To test the hypothesis, we measured the fitness of the flies FSM after culturing them for one generation on RM, in order to remove the assumed maternal effect. As expected, this time FSM demonstrated higher fitness on SM compared to control flies (FRM) and to FSM before the removal of the maternal effect. The results support the idea that non-adaptive phenotypic plasticity and maternal effects can mask adaptation to adverse environments and prohibit ecological divergence and speciation by allowing the migrants

  3. A long standoff profilometer for surface inspection in adverse environments based on conoscopic holography

    NASA Astrophysics Data System (ADS)

    Enguita, Jose M.; Alvarez, Ignacio; Fraga, Cesar; Marina, Jorge; Fernandez, Yolanda; Sirat, Gabriel

    2005-06-01

    One of the more challenging applications of optical metrology is real-time dimensional control and surface inspection in industrial applications, where strong requirements of cost, setup and applicability in adverse environments, greatly limit the number of applicable technologies. This paper shows an optic profilometer developed specifically for this purpose. This device, based on Conoscopic holography, is able to obtain a distance profile of a target in a single-axis scan; works from long distances and still keeps good resolution with a very easy and reliable setup. The first part of the paper introduces the working principles of Conoscopic holography and shows the sensor set-up. Necessary algorithms for obtaining the distance information are presented and the whole process is illustrated with real captures of test objects. The second part focuses on a real example of this technology applied in an on-line inspection system in steel continuous casting funded by the European Committee for Steel and Carbon, and which is currently working in Aceralia LDA steelmaking factory in Asturias, Spain). The system is placed in the process line and performs on-line detection of surface defects over hot steel slabs from a distance of 1200 mm. 100% of the production can be inspected without interfering with the process and without adding any delay.

  4. Adverse Impact of Electromagnetic Radiation on Urban Environment and Natural Resources using Optical Sensors

    NASA Astrophysics Data System (ADS)

    Kumar, Pawan; Katiyar, Swati; Rani, Meenu

    2016-07-01

    We are living in the age of a rapidly growing population and changing environmental conditions with an advance technical capacity.This has resulted in wide spread land cover change. One of the main causes for increasing urban heat is that more than half of the world's population lives in a rapidly growing urbanized environment. Satellite data can be highly useful to map change in land cover and other environmental phenomena with the passage of time. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The UHI for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment on climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The present paper describes the methodology and resolution dynamic urban heat island change on climate using the geospatial approach. NDVI were generated using day time LANDSAT ETM+ image of 1990, 2000 and 2013. Temperature of various land use and land cover categories was estimated. Keywords: NDVI, Surface temperature, Dynamic changes.

  5. Toward a Case Definition of Adverse Health Effects in the Environs of Industrial Wind Turbines: Facilitating a Clinical Diagnosis

    ERIC Educational Resources Information Center

    McMurtry, Robert Y.

    2011-01-01

    Internationally, there are reports of adverse health effects (AHE) in the environs of industrial wind turbines (IWT). There was multidisciplinary confirmation of the key characteristics of the AHE at the first international symposium on AHE/IWT. The symptoms being reported are consistent internationally and are characterized by crossover findings…

  6. Study on thermally induced vibration of flexible boom in various thermal environments of vacuum chamber

    NASA Astrophysics Data System (ADS)

    Kong, Changduk; Oh, Kyung-Won; Park, Hyun-Bum; Sugiyama, Y.

    2005-02-01

    In order to simulate the thermally-induced vibration phenomenon of the flexible thin boom structure of the spacecraft such as the thin solar panel and the flexible cantilever with the attached tip mass in space, the thermally-induced vibration including thermal flutter of the flexible thin boom with the concentrated tip mass was experimentally investigated at various thermal environments using a heat lamp and both vacuum and air condition using the vacuum chamber. In this experimental study, divergence speed, natural frequency and thermal strains of the thermally-induced vibration were comparatively evaluated at various thermal environment conditions. Finally the thermally-induced vibration of the flexible boom structure of the earth orbit satellite in solar radiation environment from the earth eclipse region including umbra and penumbra was simulated using the vacuum chamber and power control of the heating lamp.

  7. Thermal control materials in Mercury environment

    NASA Astrophysics Data System (ADS)

    Antonenko, J.

    2003-09-01

    Thermal control materials are under development concerning the BepiColombo mission to the planet Mercury. The vicinity to the sun creates extreme heat and radiation fluxes and, advanced materials are needed. A Multi-Layer Insulation has been developed able to withstand the high temperatures and particle fluxes. Upilex has been preferred to Kapton for the reflective screens of the MLI and Tissue Glass is used as a spacer. On sunlit surfaces a sun shield will be added to the MLI employing a ceramic fabric. Further developments for application on external surfaces are a Solar Reflector Coating and an Optical Surface Reflector. An Infrared Rejection Device will be applied within the entrance port of nadir pointing instruments and serve as a protective element to reflect or absorb the planetary infra-red radiation. This paper presents the current status in the development of the thermal insulation and the other thermal control materials. The materials selection and available test results are presented.

  8. Environment friendly thermal power dispatch: An approach

    SciTech Connect

    Sen, S.; Kothari, D.P.; Talukder, F.A.

    1997-05-01

    This article describes an approach for optimal emission power dispatch from thermal power plants with optimal operating cost. The proposed approach, called economic-emission dispatch, is based on a {lambda}-iteration technique including penalty on emissions. Sample case studies with a system of three generating units are discussed.

  9. Third World adversity: African infant precocity and the role of environment.

    PubMed

    Saugstad, Letten F

    2002-01-01

    The war against illiteracy has not been won. The number of illiterates approaches a billion. Most reside in Third World countries--former colonies--where they are caught in a poverty trap of disease, low agricultural production and environmental adversity requiring technology beyond their means. I argue against the commonly held view that this is mainly attributable to the four hundred years of traffic in men. According to the late K.O. Dike, middle men along the African coast barred foreign merchants from the hinterland, and because of this the social, political structure and sovereignty of the African states remained fundamentally unchanged during the period 1400-1807, whereas a few decades after colonisation the socio-political system collapsed and was replaced by a small rich elite and many poor, while resources were taken out of Africa. Present poverty and underdevelopment represent as great a challenge as the trade in slaves. As did the African Middle-Men of that time, African leaders now must unite in an ambitious and confident Pan-African Union demonstrating strength. Western countries should focus on reducing poverty and improving nutrition. This also makes terrorism and legal and illegal migration less likely. Education is important, but the West should not limit its effort to fighting illiteracy but should also support the establishment of institutions for higher education. Africa possessed optimal conditions and an enriched environment for human evolution. African Infant Precocity is a persistent example. The human brain, like other brains, consists 60% of poly-unsaturated fatty acids (Marine-Fat), the rest being water. A sufficient amount is required to secure optimal brain growth. It normalizes brain function, and prevents sudden cardiac and infant death, which have been increasing in Western societies. Humans are unique in having a mismatch between the need for brain food--marine fat--and our common high protein diet. Nowhere is the neglect of the

  10. The effects of adverse pressure gradients on momentum and thermal structures in transitional boundary layers. Part 2: Fluctuation quantities

    SciTech Connect

    Mislevy, S.P.; Wang, T.

    1996-10-01

    The effects of adverse pressure gradients on the thermal and momentum characteristics of a heated transitional boundary layer were investigated with free-stream turbulence ranging from 0.3 to 0.6 percent. Boundary layer measurements were conducted for two constant-K cases, K1 = {minus}0.51 {times} 10{sup {minus}6} and K2 = {minus}1.05 {times} 10{sup {minus}6}. The fluctuation quantities, u{prime}, v{prime}, t{prime}, the Reynolds shear stress ({ovr uv}), and the Reynolds heat fluxes ({ovr vt} and {ovr ut}) were measured. In general, u{prime}/U{sub {infinity}}, v{prime}/U{sub {infinity}}, and {ovr vt} have higher values across the boundary layer for the adverse pressure-gradient cases than they do for the baseline case (K = 0). The development of v{prime} for the adverse pressure gradients was more actively involved than that of the baseline. In the early transition region, the Reynolds shear stress distribution for the K2 case showed a near-wall shear developed at Y{sup +} = 70. For the baseline case, however, the maximum turbulent shear in the transition region was generated at Y{sup +} = 70, and no near-wall high-shear region was seen. Stronger adverse pressure gradients appear to produce more uniform and higher t{prime} in the near-wall region (Y{sup +} < 20) in both transitional and turbulent boundary layers. The instantaneous velocity signals did not show any clear turbulent/nonturbulent demarcations in the transition region. Increasingly stronger adverse pressure gradients seemed to produce large nonturbulent unsteadiness (or instability waves) at a similar magnitude as the turbulent spots could not be identified visually or through conventional conditional-sampling schemes. In addition, the streamwise evolution of eddy viscosity, turbulent thermal diffusivity, and Pr{sub t} are also presented.

  11. Thermal conductivity of graphene nanoribbons in noble gaseous environments

    SciTech Connect

    Zhong, Wei-Rong Xu, Zhi-Cheng; Zheng, Dong-Qin; Ai, Bao-Quan

    2014-02-24

    We investigate the thermal conductivity of suspended graphene nanoribbons in noble gaseous environments using molecular dynamics simulations. It is reported that the thermal conductivity of perfect graphene nanoribbons decreases with the gaseous pressure. The decreasing is more obvious for the noble gas with large atomic number. However, the gaseous pressure cannot change the thermal conductivity of defective graphene nanoribbons apparently. The phonon spectra of graphene nanoribbons are also provided to give corresponding supports.

  12. Degradation mechanisms of ceramic thermal barrier coatings in corrosive environments

    NASA Technical Reports Server (NTRS)

    Lau, S. K.; Bratton, R. J.

    1984-01-01

    Chemical as well as thermal-mechanical interactions between the ceramics and gas turbine combustion gases/condensates are found to play critical roles in the degradation of porous plasma-sprayed ceramic thermal barrier coatings. The detailed degradation mechanisms of several state-of-the-art ceramic thermal barrier coatings, including several zirconia compositions and a calcium silicate, in corrosive environments are examined in this paper. Approaches to extend coating lifetime are also described.

  13. Diamond windows in a thermal shock environment

    SciTech Connect

    Klein, C.A.

    1995-12-31

    For most infrared-transmitting materials the primary cause of failure in a missile window/dome application can be attributed to brittle fracture induced by tensile stresses originating from instantaneous temperature gradients generated by aerodynamic heating. To describe the thermal shock I rely on the well known expression for the maximum stress experienced by a clamped plate (or a complete sphere), if there is a linear temperature variation across the thickness and both surfaces are free to expand.

  14. Numerical simulation for thermal shock resistance of thermal protection materials considering different operating environments.

    PubMed

    Li, Weiguo; Li, Dingyu; Wang, Ruzhuan; Fang, Daining

    2013-01-01

    Based on the sensitivities of material properties to temperature and the complexity of service environment of thermal protection system on the spacecraft, ultrahigh-temperature ceramics (UHTCs), which are used as thermal protection materials, cannot simply consider thermal shock resistance (TSR) of the material its own but need to take the external constraint conditions and the thermal environment into full account. With the thermal shock numerical simulation on hafnium diboride (HfB2), a detailed study of the effects of the different external constraints and thermal environments on the TSR of UHTCs had been made. The influences of different initial temperatures, constraint strengths, and temperature change rates on the TSR of UHTCs are discussed. This study can provide a more intuitively visual understanding of the evolution of the TSR of UHTCs during actual operation conditions. PMID:23983628

  15. Casing strength degradation in thermal environment of steam injection wells

    NASA Astrophysics Data System (ADS)

    Hidayat, M. I. P.; Irawan, S.; Zaki Abdullah, Mohamad

    2016-04-01

    Degradation of the casing strength in relation with thermal cycles of steam injection process is still less explored in literature. In this paper, three-dimensional finite element (FE) analysis of casing strength degradation in thermal environment of steam injection wells is presented. 3D FE models consisting of casing-cement-formation system are developed in this study. Grade N80 casing is employed with the casing length of 3.048 m. In the analysis, cyclic thermal stresses induced on the casing in thermal environment of steam injection wells from 25 °C to 360 °C are first examined to verify the feasibility of the 3D FE models. Degradation of the casing strength in the thermal environment is subsequently investigated by applying an external pressure that represents formation pressure to the casing-cement system. The results show that the casing capability to resist the pressure is lowering as the number of thermal cycles extends, thus causing casing strength degradation in the thermal application. It is also shown that the casing may fail under external pressure below its specified collapse strength i.e. 10 % lower than the reference casing strength obtained at 360 °C.

  16. Optimal stochastic transport in inhomogeneous thermal environments

    NASA Astrophysics Data System (ADS)

    Bo, Stefano; Aurell, Erik; Eichhorn, Ralf; Celani, Antonio

    2013-07-01

    We consider the optimization of the average entropy production in inhomogeneous temperature environments within the framework of stochastic thermodynamics. For systems modeled by Langevin equations (e.g. a colloidal particle in a heat bath) it has been recently shown that a space-dependent temperature breaks the time reversal symmetry of the fast velocity degrees of freedom resulting in an anomalous contribution to the entropy production of the overdamped dynamics. We show that optimization of entropy production is determined by an auxiliary deterministic problem formally analogous to motion on a curved manifold in a potential. The “anomalous contribution” to entropy plays the role of the potential and the inverse of the diffusion tensor is the metric. We also find that entropy production is not minimized by adiabatically slow, quasi-static protocols but there is a finite optimal duration for the transport process. As an example we discuss the case of a linearly space-dependent diffusion coefficient.

  17. Thermal criticality in a repository environment

    SciTech Connect

    Morris, E.E.

    1995-11-01

    This report explores a scenario in which burial containers fail and fissile material is transported through the tuff by water to some location, away from the burial site, where an over-moderated critical mass gradually accumulates. Because of the low solubilities of plutonium and uranium, and the low ground water velocities, the analysis shows that such a scenario with {sup 239}Pu is probably impossible because the time required to accumulate a critical mass is large compared with the half-life of the {sup 239}Pu. In the case of {sup 235}U, the analysis indicates that the accumulation rates are so low that relatively small fission power levels would consume the {sup 235}U as fast as it accumulates, and that the thermal conductivity of the tuff is large enough to prevent a significant increase in temperature. Thus, the conditions for the removal of water by boiling and the associated autocatalytic increase in reactivity are not met in the case of {sup 235}U. An explosive release of energy does not appear to be possible. A simple water voiding model, which allows water removal at about the fastest possible rate, was used to explore a scenario in which the fuel accumulation rate was arbitrarily increased enough to cause water boiling and the associated dryout of the tuff. Calculations for this case indicate that disruption of the tuff, leading to a neutronic shutdown, would probably occur before an explosive energy release could be generated. Additional scenarios, which should be investigated in future work are identified.

  18. Microbiology of Methanogenesis in Thermal, Volcanic Environments

    PubMed Central

    Zeikus, J. G.; Ben-Bassat, Arie; Hegge, P. W.

    1980-01-01

    Microbial methanogenesis was examined in thermal waters, muds, and decomposing algal-bacterial mats associated with volcanic activity in Yellowstone National Park. Radioactive tracer studies with [14C]glucose, acetate, or carbonate and enrichment culture techniques demonstrated that methanogenesis occurred at temperatures near 70°C but below 80°C and correlated with hydrogen production from either geothermal processes or microbial fermentation. Three Methanobacterium thermoautotrophicum strains (YT1, YTA, and YTC) isolated from diverse volcanic habitats differed from the neotype sewage strain ΔH in deoxyribonucleic acid guanosine-plus-cytosine content and immunological properties. Microbial methanogenesis was characterized in more detail at a 65°C site in the Octopus Spring algal-bacterial mat ecosystem. Here methanogenesis was active, was associated with anaerobic microbial decomposition of biomass, occurred concomitantly with detectable microbial hydrogen formation, and displayed a temperature activity optimum near 65°C. Enumeration studies estimated more than 109 chemoorganotrophic hydrolytic bacteria and 106 chemolithotrophic methanogenic bacteria per g (dry weight) of algal-bacterial mat. Enumeration, enrichment, and isolation studies revealed that the microbial population was predominantly rod shaped and asporogenous. A prevalent chemoorganotrophic organism in the mat that was isolated from an end dilution tube was a taxonomically undescribed gram-negative obligate anaerobe (strain HTB2), whereas a prevalent chemolithotrophic methanogen isolated from an end dilution tube was identified as M. thermoautotrophicum (strain YTB). Taxonomically recognizable obligate anaerobes that were isolated from glucose and xylose enrichment cultures included Thermoanaerobium brockii strain HTB and Clostridium thermohydrosulfuricum strain 39E. The nutritional properties, growth temperature optima, growth rates, and fermentation products of thermophilic bacterial strains 39

  19. The effect of sire selection on cow mortality and early lactation culling in adverse and favorable cow survival environments.

    PubMed

    Dechow, C D; Goodling, R C; Rhode, S P

    2012-02-01

    The objective of this study was to determine the extent that genetic selection can help reduce dairy cow mortality and early lactation culling in adverse cow survival environments. Two datasets were constructed. The first contained 100,911 mortality records and 171,178 sixty-day culling records from 1467 herds. Cows that left the herd (culled or died) from 21 days prior to a due date through 60 days in milk were considered a 60-day cull. Cows were classified as belonging to herds with adverse cow survival environments (≥ 4.4% mortality rate and ≥ 7.1% 60-day cull rate) or favorable cow survival environments (<4.4% mortality rate and <7.1% 60-day cull rate). The second dataset included 20,438 mortality records and 34,942 sixty-day culling records from 314 herds with a known herd management system. Cows from both datasets were stratified into quartiles based on their sire's predicted transmitting ability (PTA) for productive life and other traits. Cows in the first dataset were also stratified into high (>50th percentile) and low (≤ 50th percentile) groups based on their sire's PTA for daughter calving ease and daughter stillbirth rates. Mortality and 60-day culling in the first dataset were evaluated with logistic regression models with the independent effects of sire PTA quartile, cow survival environment (adverse or favorable), the interaction of sire PTA quartile with cow survival environment, lactation number, age within lactation number, and herd-calving-cluster. The second dataset was analyzed in the same manner, but with cow survival environment replaced by herd management system. The estimated proportion of lactations that ended in death declined from 9.0% to 6.8% and 60-day culling incidence from 7.6% to 4.9% as sire productive life PTA went from the lowest to highest quartile in adverse cow survival environments. The corresponding reduction in mortality (0.7%) and 60-day culling (0.9%) were also significant in favorable cow survival environments

  20. The Assessment of the Thermal Environment. A Review

    PubMed Central

    Macpherson, R. K.

    1962-01-01

    The development of methods for the assessment of the thermal environment is traced, and the reasons for the devising of special indices of thermal stress are discussed. The more important of the indices are described, and it is shown that they conform to a restricted number of types. The general trend in their evolution is indicated and some guidance is given in their use. PMID:14468056

  1. Temperature measurements using multicolor pyrometry in thermal radiation heating environments

    SciTech Connect

    Fu, Tairan; Liu, Jiangfan; Duan, Minghao; Zong, Anzhou

    2014-04-15

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100–2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700–1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

  2. The effects of adverse pressure gradients on momentum and thermal structures in transitional boundary layers. Part 1: Mean quantities

    SciTech Connect

    Mislevy, S.P.; Wang, T.

    1996-10-01

    The effects of adverse pressure gradients on the thermal and momentum characteristics of a heated transitional boundary layer were investigated with free-stream turbulence ranging from 0.3 to 0.6 %. The acceleration parameter, K, was kept constant along the test section. Both surface heat transfer and boundary layer measurements were conducted. The boundary layer measurements were conducted with a three-wire probe (two velocity wires and one temperature wire) for two representative cases, K1 = {minus}0.51 {times} 10{sup {minus}6} and K2 = {minus}1.05 {times} 10{sup {minus}6}. The surface heat transfer measurements were conducted for K values ranging from {minus}0.045 {times} 10{sup {minus}6} to {minus}1.44 {times} 10{sup {minus}6} over five divergent wall angles. The Stanton numbers of the cases with adverse pressure gradients were greater than that of the zero-pressure-gradient turbulent correlation in the low-Reynolds-number turbulent flow, and the difference increased as the adverse pressure gradient was increased. The adverse pressure gradient caused earlier transition onset and shorter transition length based on Re{sub x}, Re*{sub {delta}}, and Re{sub {theta}} in comparison to zero-pressure-gradient conditions. As expected, there was a reduction in skin friction as the adverse pressure gradient increased. In the U{sup +}-Y{sup +} coordinates, the adverse pressure gradients had a significant effect on the mean velocity profiles in the near-wall region for the late-laminar and early transition stations. The mean temperature profile was observed to precede the velocity profile in starting and ending the transition process, opposite to what occurred in favorable pressure gradient cases in previous studies. A curve fit of the turbulent temperature profile in the log-linear region for the K2 case gave a conduction layer thickness of Y{sup +}=9.8 and an average Pr{sub t}=0.71. The wake region of the turbulent mean temperature profile was significantly suppressed.

  3. Nonisothermal turbulent boundary-layer adverse pressure gradient large scale thermal structure measurements

    SciTech Connect

    Bagheri, N.; White, B.R.; Lei, T.

    1994-01-01

    Hot-wire anemometry measurements in an incompressible turbulent boundary-layer flow over a heated flat plate under equilibrium adverse-pressure-gradient conditions (beta = 1.8) were made for two different temperature difference cases (10 and 15 C) between the wall and the freestream. Space-time correlations of temperature fluctuations (T`) were obtained with a pair of subminiature temperature fluctuation probes. The mean convection velocities, the mean inclination angles, and coherence characteristics of the T` large-scale structure were determined. The present temperature structures measurements for a nonisothermal boundary layer are compared to the zero-pressure-gradient case with identical temperature differences previously reported, in which the mean convection velocity of the T` structure was a function of position y(sup +) and independent of the limited temperature-difference cases tested. The three major findings of the present study, as compared to the zero-pressure-gradient case, are (1) the mean convection speed of the T` structure under beta = 1.8 pressure-gradient conditions was found to be substantially lower in the logarithmic core region than the zero-pressure-gradient case. Additionally, the mean convection speed is felt by the authors to be a function of pressure-gradient parameter beta; (2) the mean inclination angle of the T` structure to the wall under the adverse-pressure-gradient flow was 32 deg, which compares favorably to the 30-deg value of the zero-pressure-gradient case; and (3) the limited data suggests that the mean convection velocity of the T` structure is a function of y(sup +) and independent of the limited temperature-difference cases tested. 11 refs.

  4. Performance characterization of fiber Bragg grating thermal response in space vacuum thermal environment

    NASA Astrophysics Data System (ADS)

    Jiang, Junfeng; Song, Luyao; Liu, Tiegen; Zhang, Jingchuan; Liu, Kun; Wang, Shuang; Yin, Jinde; Zhao, Peng; Xie, Jihui; Wu, Fan; Zhang, Xuezhi

    2013-12-01

    We investigated the fiber Bragg grating (FBG) thermal response in space vacuum thermal environment. The FBGs were packaged with 6061-T6 aluminum. The liquid nitrogen immersion experiment results show that its wavelength shift standard deviation is 0.76 pm for 217 h. The combination effect of vacuum and cryogenic temperature was studied by thermal cycling process in space environment simulator. The FBG sensors show accuracy better than 2% full scale, and the hysteresis errors are below 1%. It proves that these metal packaged FBG sensors can survive and meet the requirement of space measurement.

  5. Performance characterization of fiber Bragg grating thermal response in space vacuum thermal environment.

    PubMed

    Jiang, Junfeng; Song, Luyao; Liu, Tiegen; Zhang, Jingchuan; Liu, Kun; Wang, Shuang; Yin, Jinde; Zhao, Peng; Xie, Jihui; Wu, Fan; Zhang, Xuezhi

    2013-12-01

    We investigated the fiber Bragg grating (FBG) thermal response in space vacuum thermal environment. The FBGs were packaged with 6061-T6 aluminum. The liquid nitrogen immersion experiment results show that its wavelength shift standard deviation is 0.76 pm for 217 h. The combination effect of vacuum and cryogenic temperature was studied by thermal cycling process in space environment simulator. The FBG sensors show accuracy better than 2% full scale, and the hysteresis errors are below 1%. It proves that these metal packaged FBG sensors can survive and meet the requirement of space measurement. PMID:24387420

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

    PubMed

    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. PMID:26267512

  7. Long duration exposure facility post-flight thermal analysis: Orbital/thermal environment data package

    NASA Technical Reports Server (NTRS)

    Berrios, William M.

    1990-01-01

    A post flight mission thermal environment for the Long Duration Exposure Facility was created as part of the thermal analysis data reduction effort. The data included herein is the thermal parameter data used in the calculation of boundary temperatures. This boundary temperature data is to be released in the near future for use by the LDEF principal investigators in the final analysis of their particular experiment temperatures. Also included is the flight temperature data as recorded by the LDEF Thermal Measurements System (THERM) for the first 90 days of flight.

  8. Thermal Radiation from Nuclear Detonations in Urban Environments

    SciTech Connect

    Marrs, R E; Moss, W C; Whitlock, B

    2007-06-04

    There are three principal causes of ''prompt'' casualties from a nuclear detonation: nuclear (gamma-ray and neutron) radiation, thermal radiation, and blast. Common estimates of the range of these prompt effects indicate that thermal radiation has the largest lethal range [1]. Non-lethal skin burns, flash blindness, and retinal burns occur out to much greater range. Estimates of casualties from thermal radiation assume air bursts over flat terrain. In urban environments with multiple buildings and terrain features, the extent of thermal radiation may be significantly reduced by shadowing. We have developed a capability for calculating the distribution of thermal energy deposition in urban environments using detailed 3D computer models of actual cities. The size, height, and radiated power from the fireball as a function of time are combined with ray tracing to calculate the energy deposition on all surfaces. For surface bursts less than 100 kt in locations with large buildings or terrain features, the calculations confirm the expected reduction in thermal damage.

  9. CALORSTOCK 1994: Thermal energy storage. Better economy, environment, technology

    NASA Astrophysics Data System (ADS)

    Kangas, M. T.; Lund, P. D.

    This publication is the second volume of the Proceedings of CALORSTOCK'94, the Sixth International Conference on Thermal Energy Storage held in Espoo, Finland on 22-25 Aug. 1994. This volume contains 51 presentations from the following six sessions: Chemical storage; Heat storage and environment; Central solar heating plants with seasonal storage; Water storage pits and tanks; Cooling; and National activities.

  10. Thermal environment. [physiological basis for temperature tolerance limits

    NASA Technical Reports Server (NTRS)

    Waligora, J. M.

    1979-01-01

    The physiological effects, discomfort, and performance degradation associated with an imbalanced thermal environment are discussed. Temperature tolerance limits are set using thermoregulation models and experimental results. The effects of interacting environmental factors, individual variations, and exposure duration on tolerance limits are considered.

  11. Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.

    2015-01-01

    The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

  12. Managing the adverse thermal effects of urban development in a densely populated Chinese city.

    PubMed

    Weng, Qihao; Yang, Shihong

    2004-02-01

    Guangzhou city in South China has experienced an accelerated urban development since the 1980s. This paper examines the impact of the urban development on urban heat islands through a historical analysis of urban-rural air temperature differences. Remote sensing techniques were applied to derive information on land use/cover and land surface temperatures and to assess the thermal response patterns of land cover types. The results revealed an overriding importance of urban land cover expansion in the changes in heat island intensity and surface temperature patterns. Urban development was also related to a continual air temperature increase in the 1980s and 1990s. The combined use of satellite-derived vegetation and land cover distributions with land surface temperature maps provides a potential useful tool for many planning applications. The city's greening campaigns and landscaping designs should consider the different cooling effects of forest, shrubs and grassy lawns for temperature control and should plant more tall trees. PMID:15160740

  13. Optical devices in adverse environments; Proceedings of the Meeting, Cannes, France, Nov. 19, 20, 1987

    NASA Astrophysics Data System (ADS)

    Greenwell, Roger A.

    Recent advances in the design of fiber-optic devices, test equipment, optical sensors, and lasers for operation in hostile environments are discussed in reviews and reports. Topics examined include radiation effects on optical fibers, the effect of H2 treatment and water content on the recovery of undoped core fibers after pulsed and continuous irradiation, the NATO test program for optical fibers and components, alpha-irradiation damage to borosilicate glasses, high-reliability optical components for undersea light-wave systems, the behavior of Si optoelectronic components under gamma irradiation, optical devices and sensors of special-purpose fibers, and a fiber-optic microprobe for interferometric measurements in generators.

  14. The influence of outdoor thermal environment on young Japanese females

    NASA Astrophysics Data System (ADS)

    Kurazumi, Yoshihito; Ishii, Jin; Kondo, Emi; Fukagawa, Kenta; Bolashikov, Zhecho Dimitrov; Sakoi, Tomonori; Tsuchikawa, Tadahiro; Matsubara, Naoki; Horikoshi, Tetsumi

    2014-07-01

    The influence of short wave solar radiation appears to be strong outdoors in summer, and the influence of airflow appears to be strong outdoors in winter. The purpose of this paper was to clarify the influence of the outdoor environment on young Japanese females. This research shows the relationship between the physiological and psychological responses of humans and the enhanced conduction-corrected modified effective temperature (ETFe). Subjective experiments were conducted in an outdoor environment. Subjects were exposed to the thermal environment in a standing posture. Air temperature, humidity, air velocity, short wave solar radiation, long wave radiation, ground surface temperature, sky factor, and the green solid angle were measured. The temperatures of skin exposed to the atmosphere and in contact with the ground were measured. Thermal sensation and thermal comfort were measured by means of rating the whole-body thermal sensation (cold-hot) and the whole body thermal comfort (comfortable-uncomfortable) on a linear scale. Linear rating scales are given for the hot (100) and cold (0), and comfortable (100) and uncomfortable (0) directions only. Arbitrary values of 0 and 100 were assigned to each endpoint, the reported values read in, and the entire length converted into a numerical value with an arbitrary scale of 100 to give a linear rating scale. The ETFe considered to report a neither hot nor cold, thermally neutral sensation of 50 was 35.9 °C, with 32.3 °C and 42.9 °C, respectively, corresponding to the low and high temperature ends of the ETFe considered to report a neither comfortable nor uncomfortable comfort value of 50. The mean skin temperature considered to report a neither hot nor cold, thermally neutral sensation of 50 was 33.3 °C, with 31.0 °C and 34.3 °C, respectively, corresponding to the low and high temperature ends of the mean skin temperature considered to report a neither comfortable nor uncomfortable comfort value of 50. The

  15. Thermal preparation of foods in space-vehicle environments

    NASA Technical Reports Server (NTRS)

    Bannerot, R. B.; Cox, J. E.; Chen, C. K.; Heidelbaugh, N. D.

    1974-01-01

    Convection is the primary heat transfer mechanism for most foods heated in an earth-based environment. In contrast, in the low-gravity environment of space flight, the primary heat transfer mechanism is conduction (or radiation in the absence of a conducting medium). Conduction heating is significantly slower and less efficient than convection heating. This fact poses a problem for food heating during space flight. A numerical model has been developed to evaluate this problem. This model simulates the food-heating process for Skylab. The model includes the effect of a thermally controlled on/off heat flux. Parametric studies using this model establish how the required heating time is affected by: the thermal diffusivity of the nutrient materials, the power level of the heater, the initial food temperatures, and the food container dimensions.

  16. Interferometric Tomographic Measurement of an Instataneous Flow Field Under Adverse Environments

    NASA Technical Reports Server (NTRS)

    Yu, En-Xi; Cha, Soyoung Stephen; Burner, Alpheus W.

    1995-01-01

    Measurement of an instantaneous flow field by interferometric tomography, that is, reconstruction of a three-dimensional refractive-index field from multi-directional projection data, has been conducted. In order to simulate the expected experimental arrangement at a wind tunnel, reconstructions are made from a restricted view angle less than 40 degrees and incomplete projections. In addition, appreciable ambient air and experimental setup disturbances are present. A new phase-stepping technique, based on a generalized phase-stepping approach of a four-bucket model, is applied for expeditious and accurate phase information extraction from projection interferograms under the harsh environments. Phase errors caused by the various disturbances, which can include ambient refractive-index change, optical component disturbance, hologram repositioning error, etc., are partially compensated with a linear corrective model. A new computational tomographic technique based on a series expansion approach was also utilized to efficiently deal with arbitrary boundary shapes and the continuous flow fields in reconstruction. The results of the preliminary investigation are encouraging; however, the technique needs to be further developed in the future through refinement of the approaches reported here and through hybridization with previously developed techniques. Keywords: interferometry, tomography, phase stepping

  17. Thermal Insulating Concrete Wall Panel Design for Sustainable Built Environment

    PubMed Central

    Zhou, Ao; Wong, Kwun-Wah

    2014-01-01

    Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes. PMID:25177718

  18. Thermal insulating concrete wall panel design for sustainable built environment.

    PubMed

    Zhou, Ao; Wong, Kwun-Wah; Lau, Denvid

    2014-01-01

    Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes. PMID:25177718

  19. A new time-adaptive discrete bionic wavelet transform for enhancing speech from adverse noise environment

    NASA Astrophysics Data System (ADS)

    Palaniswamy, Sumithra; Duraisamy, Prakash; Alam, Mohammad Showkat; Yuan, Xiaohui

    2012-04-01

    Automatic speech processing systems are widely used in everyday life such as mobile communication, speech and speaker recognition, and for assisting the hearing impaired. In speech communication systems, the quality and intelligibility of speech is of utmost importance for ease and accuracy of information exchange. To obtain an intelligible speech signal and one that is more pleasant to listen, noise reduction is essential. In this paper a new Time Adaptive Discrete Bionic Wavelet Thresholding (TADBWT) scheme is proposed. The proposed technique uses Daubechies mother wavelet to achieve better enhancement of speech from additive non- stationary noises which occur in real life such as street noise and factory noise. Due to the integration of human auditory system model into the wavelet transform, bionic wavelet transform (BWT) has great potential for speech enhancement which may lead to a new path in speech processing. In the proposed technique, at first, discrete BWT is applied to noisy speech to derive TADBWT coefficients. Then the adaptive nature of the BWT is captured by introducing a time varying linear factor which updates the coefficients at each scale over time. This approach has shown better performance than the existing algorithms at lower input SNR due to modified soft level dependent thresholding on time adaptive coefficients. The objective and subjective test results confirmed the competency of the TADBWT technique. The effectiveness of the proposed technique is also evaluated for speaker recognition task under noisy environment. The recognition results show that the TADWT technique yields better performance when compared to alternate methods specifically at lower input SNR.

  20. High-Rise Buildings versus Outdoor Thermal Environment in Chongqing

    PubMed Central

    Lu, Jun; Chen, Jin-hua; Tang, Ying; Feng, Yuan; Wang, Jin-sha

    2007-01-01

    This paper gives a brief description of the over quick urbanization since Chongqing, one of the biggest cities in China, has been a municipality directly under the Central Government in 1997, excessive development and exceeding increase of high-rise buildings because of its special geographical position which finally leads to the worsening of the urban outdoor thermal environment. Then, this paper makes a bright balance to the field measurement and simulated results of the wind speed field, temperature field of one multifunctional high-rise building in Chongqing university located in the city center, and the contrasted results validate the correctness of CFD in the outdoor thermal environmental simulation, expose the disadvantages of high-rise buildings on the aspects of blocking the wind field, decreasing wind speed which results in accumulation of the air-conditioning heat revolving around and periscian region where sunshine can not rip into. Finally, in order to improve the urban outdoor thermal environment near the high-rise buildings especially for the angle of natural ventilation, this paper simulates the wind environment in different architectural compositions and architectural layouts by CFD, and the simulated results show that freestyle and tower buildings which can guarantee the wind speed and take the air-conditioning heat away are much suitable and reasonable for the special Chongqing geography. These conclusions can also be used as a reference in other mountain cities, especially for the one with a great number of populations.

  1. Polar Lunar Regions: Exploiting Natural and Augmented Thermal Environments

    NASA Technical Reports Server (NTRS)

    Brannon, David; Ryan, Robert E.; Underwood, Lauren W.; Russell, Kristen

    2010-01-01

    In the polar regions of the Moon, some areas within craters are permanently shadowed from solar illumination and can drop to temperatures of 100 K or lower. These sites may serve as cold traps, capturing ice and other volatile compounds, possibly for eons. Interestingly, ice stored in these locations could potentially alter how lunar exploration is conducted. Within craters inside craters (double-shaded craters) that are shaded from thermal re-radiation and from solar illuminated regions, even colder regions should exist and, in many cases, temperatures in these regions never exceed 50 K. Working in these harsh environments with existing conventional systems, exploration or mining activities could be quite daunting and challenging. However, if the unique characteristics of these environments were exploited, the power, weight, and total mass that is required to be carried from the Earth to the Moon for lunar exploration and research would be substantially reduced. In theory, by minimizing the heat transfer between an object and the lunar surface, temperatures near absolute zero can be produced. In a single or double-shaded crater, if the object was isolated from the variety of thermal sources and was allowed to radiatively cool to space, the achievable temperature would be limited by the 3 K cosmic background and the anomalous solar wind that can strike the object being cooled. Our analysis shows that under many circumstances, with some simple thermal radiation shielding, it is possible to establish environments with temperatures of several degrees Kelvin.

  2. Innovative Multi-Environment, Multimode Thermal Control System

    NASA Technical Reports Server (NTRS)

    Singh, Bhim S.; Hasan, Mohammad H.

    2007-01-01

    Innovative multi-environment multimode thermal management architecture has been described that is capable of meeting widely varying thermal control requirements of various exploration mission scenarios currently under consideration. The proposed system is capable of operating in a single-phase or two-phase mode rejecting heat to the colder environment, operating in a two-phase mode with heat pump for rejecting heat to a warm environment, as well as using evaporative phasechange cooling for the mission phases where the radiator is incapable of rejecting the required heat. A single fluid loop can be used internal and external to the spacecraft for the acquisition, transport and rejection of heat by the selection of a working fluid that meets NASA safety requirements. Such a system may not be optimal for each individual mode of operation but its ability to function in multiple modes may permit global optimization of the thermal control system. The architecture also allows flexibility in partitioning of components between the various Constellation modules to take advantage of operational requirements in various modes consistent with the mission needs. Preliminary design calculations using R-134 as working fluid show the concept to be feasible to meet the heat rejection requirements that are representative of the Crew Exploration Vehicle and Lunar Access Module for nominal cases. More detailed analyses to establish performance under various modes and environmental conditions are underway.

  3. Quantum systems in a stationary environment out of thermal equilibrium

    NASA Astrophysics Data System (ADS)

    Bellomo, Bruno; Messina, Riccardo; Felbacq, Didier; Antezza, Mauro

    2013-01-01

    We discuss how the thermalization of an elementary quantum system is modified when the system is placed in an environment out of thermal equilibrium. To this aim we provide a detailed investigation of the dynamics of an atomic system placed close to a body of arbitrary geometry and dielectric permittivity, whose temperature TM is different from that of the surrounding walls TW. A suitable master equation for the general case of an N-level atom is first derived and then specialized to the cases of a two- and three-level atom. Transition rates and steady states are explicitly expressed as a function of the scattering matrices of the body and become both qualitatively and quantitatively different from the case of radiation at thermal equilibrium. Out of equilibrium, the system steady state depends on the system-body distance, on the geometry of the body, and on the interplay of all such parameters with the body optical resonances. While a two-level atom tends toward a thermal state, this is not the case already in the presence of three atomic levels. This peculiar behavior can be exploited, for example, to invert the populations ordering and to provide an efficient cooling mechanism for the internal state of the quantum system. We finally provide numerical studies and asymptotic expressions when the body is a slab of finite thickness. Our predictions can be relevant for a wide class of experimental configurations out of thermal equilibrium involving different physical realizations of two- or three-level systems.

  4. Mapping Thermal Habitat of Ectotherms Based on Behavioral Thermoregulation in a Controlled Thermal Environment

    NASA Astrophysics Data System (ADS)

    Fei, T.; Skidmore, A.; Liu, Y.

    2012-07-01

    Thermal environment is especially important to ectotherm because a lot of physiological functions rely on the body temperature such as thermoregulation. The so-called behavioural thermoregulation function made use of the heterogeneity of the thermal properties within an individual's habitat to sustain the animal's physiological processes. This function links the spatial utilization and distribution of individual ectotherm with the thermal properties of habitat (thermal habitat). In this study we modelled the relationship between the two by a spatial explicit model that simulates the movements of a lizard in a controlled environment. The model incorporates a lizard's transient body temperatures with a cellular automaton algorithm as a way to link the physiology knowledge of the animal with the spatial utilization of its microhabitat. On a larger spatial scale, 'thermal roughness' of the habitat was defined and used to predict the habitat occupancy of the target species. The results showed the habitat occupancy can be modelled by the cellular automaton based algorithm at a smaller scale, and can be modelled by the thermal roughness index at a larger scale.

  5. Optimized Radiator Geometries for Hot Lunar Thermal Environments

    NASA Technical Reports Server (NTRS)

    Ochoa, Dustin

    2013-01-01

    The optimum radiator configuration in hot lunar thermal environments is one in which the radiator is parallel to the ground and has no view to the hot lunar surface. However, typical spacecraft configurations have limited real estate available for top-mounted radiators, resulting in a desire to use the spacecraft's vertically oriented sides. Vertically oriented, flat panel radiators will have a large view factor to the lunar surface, and thus will be subjected to significant incident lunar infrared heat. Consequently, radiator fluid temperatures will need to exceed approximately 325 K (assuming standard spacecraft radiator optical properties) in order to provide positive heat rejection at lunar noon. Such temperatures are too high for crewed spacecraft applications in which a heat pump is to be avoided. A recent study of vertically oriented radiator configurations subjected to lunar noon thermal environments led to the discovery of a novel radiator concept that yielded positive heat rejection at lower fluid temperatures. This radiator configuration, called the Intense Thermal Infrared Reflector (ITIR), has exhibited superior performance to all previously analyzed concepts in terms of heat rejection in the lunar noon thermal environment. A key benefit of ITIR is the absence of louvers or other moving parts and its simple geometry (no parabolic shapes). ITIR consists of a specularly reflective shielding surface and a diffuse radiating surface joined to form a horizontally oriented V-shape (shielding surface on top). The point of intersection of these surfaces is defined by two angles, those which define the tilt of each surface with respect to the local horizontal. The optimum set of these angles is determined on a case-by-case basis. The idea assumes minimal conductive heat transfer between shielding and radiating surfaces, and a practical design would likely stack sets of these surfaces on top of one another to reduce radiator thickness.

  6. Numerical Analysis of Thermal Comfort at Urban Environment

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, K.; Belias, C.

    2009-08-01

    The present paper refers to the numerical simulation of air velocity at open air spaces and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an open environment area in Athens (athletic park), named "Serafeio Athletic and Cultural Centre," trying to form them in such way that will lead to the thermal comfort of the area's visitors. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This modelling procedure is intended to contribute to the effort towards designing open areas, such as parks, squares or outdoor building environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.

  7. Effects of thermal environment on sleep and circadian rhythm

    PubMed Central

    2012-01-01

    The thermal environment is one of the most important factors that can affect human sleep. The stereotypical effects of heat or cold exposure are increased wakefulness and decreased rapid eye movement sleep and slow wave sleep. These effects of the thermal environment on sleep stages are strongly linked to thermoregulation, which affects the mechanism regulating sleep. The effects on sleep stages also differ depending on the use of bedding and/or clothing. In semi-nude subjects, sleep stages are more affected by cold exposure than heat exposure. In real-life situations where bedding and clothing are used, heat exposure increases wakefulness and decreases slow wave sleep and rapid eye movement sleep. Humid heat exposure further increases thermal load during sleep and affects sleep stages and thermoregulation. On the other hand, cold exposure does not affect sleep stages, though the use of beddings and clothing during sleep is critical in supporting thermoregulation and sleep in cold exposure. However, cold exposure affects cardiac autonomic response during sleep without affecting sleep stages and subjective sensations. These results indicate that the impact of cold exposure may be greater than that of heat exposure in real-life situations; thus, further studies are warranted that consider the effect of cold exposure on sleep and other physiological parameters. PMID:22738673

  8. Altered fetal skeletal muscle nutrient metabolism following an adverse in utero environment and the modulation of later life insulin sensitivity.

    PubMed

    Dunlop, Kristyn; Cedrone, Megan; Staples, James F; Regnault, Timothy R H

    2015-01-01

    The importance of the in utero environment as a contributor to later life metabolic disease has been demonstrated in both human and animal studies. In this review, we consider how disruption of normal fetal growth may impact skeletal muscle metabolic development, ultimately leading to insulin resistance and decreased insulin sensitivity, a key precursor to later life metabolic disease. In cases of intrauterine growth restriction (IUGR) associated with hypoxia, where the fetus fails to reach its full growth potential, low birth weight (LBW) is often the outcome, and early in postnatal life, LBW individuals display modifications in the insulin-signaling pathway, a critical precursor to insulin resistance. In this review, we will present literature detailing the classical development of insulin resistance in IUGR, but also discuss how this impaired development, when challenged with a postnatal Western diet, may potentially contribute to the development of later life insulin resistance. Considering the important role of the skeletal muscle in insulin resistance pathogenesis, understanding the in utero programmed origins of skeletal muscle deficiencies in insulin sensitivity and how they may interact with an adverse postnatal environment, is an important step in highlighting potential therapeutic options for LBW offspring born of pregnancies characterized by placental insufficiency. PMID:25685986

  9. Altered Fetal Skeletal Muscle Nutrient Metabolism Following an Adverse In Utero Environment and the Modulation of Later Life Insulin Sensitivity

    PubMed Central

    Dunlop, Kristyn; Cedrone, Megan; Staples, James F.; Regnault, Timothy R.H.

    2015-01-01

    The importance of the in utero environment as a contributor to later life metabolic disease has been demonstrated in both human and animal studies. In this review, we consider how disruption of normal fetal growth may impact skeletal muscle metabolic development, ultimately leading to insulin resistance and decreased insulin sensitivity, a key precursor to later life metabolic disease. In cases of intrauterine growth restriction (IUGR) associated with hypoxia, where the fetus fails to reach its full growth potential, low birth weight (LBW) is often the outcome, and early in postnatal life, LBW individuals display modifications in the insulin-signaling pathway, a critical precursor to insulin resistance. In this review, we will present literature detailing the classical development of insulin resistance in IUGR, but also discuss how this impaired development, when challenged with a postnatal Western diet, may potentially contribute to the development of later life insulin resistance. Considering the important role of the skeletal muscle in insulin resistance pathogenesis, understanding the in utero programmed origins of skeletal muscle deficiencies in insulin sensitivity and how they may interact with an adverse postnatal environment, is an important step in highlighting potential therapeutic options for LBW offspring born of pregnancies characterized by placental insufficiency. PMID:25685986

  10. Thermal System Upgrade of the Space Environment Simulation Test Chamber

    NASA Technical Reports Server (NTRS)

    Desai, Ashok B.

    1997-01-01

    The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

  11. Guidelines on Thermal Comfort of Air Conditioned Indoor Environment

    NASA Astrophysics Data System (ADS)

    Miura, Toyohiko

    The thermal comfort of air conditioned indoor environment for workers depended, of course, on metabolic rate of work, race, sex, age, clothing, climate of the district and state of acclimatization. The attention of the author was directed to the seasonal variation and the sexual difference of comfortable temperature and a survey through a year was conducted on the thermal comfort, and health conditions of workers engaged in light work in a precision machine factory, in some office workers. Besides, a series of experiments were conducted for purpose of determinning the optimum temperature of cooling in summer time in relation to the outdoor temperature. It seemed that many of workers at present would prefer somewhat higher temperature than those before the World War II. Forty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerably heavier.

  12. Qualification of UHF Antenna for Extreme Martian Thermal Environments

    NASA Technical Reports Server (NTRS)

    Ramesham, Rajeshuni; Amaro, Luis R.; Brown, Paula R.; Usiskin, Robert

    2013-01-01

    The purpose of this development was to validate the use of the external Rover Ultra High Frequency (RUHF) antenna for space under extreme thermal environments to be encountered during the surface operations of the Mars Science Laboratory (MSL) mission. The antenna must survive all ground operations plus the nominal 670 Martian sol mission that includes summer and winter seasons of the Mars thermal environment.The qualification effort was to verify that the RUHF antenna design and its bonding and packaging processes are adequate to survive the harsh environmental conditions. The RUHF is a quadrifilar helix antenna mounted on the MSL Curiosity rover deck. The main components of the RUHF antenna are the helix structure, feed cables, and hybrid coupler, and the high-power termination load. In the case of MSL rover externally mounted hardware, not only are the expected thermal cycle depths severe, but there are temperature offsets between the Mars summer and winter seasons. The total number of temperature cycles needed to be split into two regimes of summer cycles and winter cycles. The qualification test was designed to demonstrate a survival life of three times more than all expected ground testing, plus a nominal 670 Martian sol missions. Baseline RF tests and a visual inspection were performed prior to the start of the qualification test. Functional RF tests were performed intermittently during chamber breaks over the course of the qualification test. For the RF return loss measurements, the antenna was tested in a controlled environment outside the thermal chamber with a vector network analyzer that was calibrated over the antenna s operational frequency range. A total of 2,010 thermal cycles were performed. Visual inspection showed a dulling of the solder material. This change will not affect the performance of the antenna. No other changes were observed. RF tests were performed on the RUHF helix antenna, hybrid, and load after the 2,010 qualification cycles test

  13. Polar Lunar Regions: Exploiting Natural and Augmented Thermal Environments

    NASA Technical Reports Server (NTRS)

    Ryan, Robert E.; McKellip, Rodney; Brannon, David P.; Underwood, Lauren; Russell, Kristen J.

    2007-01-01

    In polar regions of the Moon, some areas within craters are permanently shadowed from solar illumination and can reach temperatures of 100 K or less. These regions could serve as cold traps, capturing ice and other volatile compounds. These potential ice stores have many applications for lunar exploration. Within double-shaded craters, even colder regions exist, with temperatures never exceeding 50 K in many cases. Observed temperatures suggest that these regions could enable equivalent liquid nitrogen cryogenic functions. These permanently shaded polar craters also offer unprecedented high-vacuum cryogenic environments, which in their current state could support cryogenic applications. Besides ice stores, the unique conditions at the lunar poles harbor an environment that provides an opportunity to reduce the power, weight, and total mass that needs to be carried from the Earth to the Moon for lunar exploration and research. Reducing the heat flux of geothermal, black body radiation can have significant impacts on the achievable temperature. With a few manmade augmentations, permanently shaded craters located near the lunar poles achieve temperatures even lower than those that naturally exist. Our analysis reveals that lightweight thermal shielding within shaded craters could create an environment several Kelvin above absolute zero. The temperature ranges of both naturally shaded and thermally augmented craters could enable the long-term storage of most gases, low-temperature superconductors for large magnetic fields, devices and advanced high-speed computing instruments. Augmenting thermal conditions in these craters could then be used as a basis for the development of an advanced thermal management architecture that would support a wide variety of cryogenically based applications. Lunar exploration and habitation capabilities would significantly benefit if permanently shaded craters, augmented with thermal shielding, were used to facilitate the operation of near

  14. Rover Low Gain Antenna Qualification for Deep Space Thermal Environments

    NASA Technical Reports Server (NTRS)

    Ramesham, Rajeshuni; Amaro, Luis R.; Brown, Paula R.; Usiskin, Robert; Prater, Jack L.

    2013-01-01

    A method to qualify the Rover Low Gain Antenna (RLGA) for use during the Mars Science Laboratory (MSL) mission has been devised. The RLGA antenna must survive all ground operations, plus the nominal 670 Martian sol mission that includes the summer and winter seasons of the Mars thermal environment. This qualification effort was performed to verify that the RLGA design, its bonding, and packaging processes are adequate. The qualification test was designed to demonstrate a survival life of three times more than all expected ground testing, plus a nominal 670 Martian sol missions. Baseline RF tests and a visual inspection were performed on the RLGA hardware before the start of the qualification test. Functional intermittent RF tests were performed during thermal chamber breaks over the course of the complete qualification test. For the return loss measurements, the RLGA antenna was moved to a test area. A vector network analyzer was calibrated over the operational frequency range of the antenna. For the RLGA, a simple return loss measurement was performed. A total of 2,010 (3 670 or 3 times mission thermal cycles) thermal cycles was performed. Visual inspection of the RLGA hardware did not show any anomalies due to the thermal cycling. The return loss measurement results of the RLGA antenna after the PQV (Package Qualification and Verification) test did not show any anomalies. The antenna pattern data taken before and after the PQV test at the uplink and downlink frequencies were unchanged. Therefore, the developed design of RLGA is qualified for a long-duration MSL mission.

  15. Measurements of the thermal plasma environment of the space shuttle

    NASA Astrophysics Data System (ADS)

    Raitt, W. J.; Siskind, D. E.; Banks, P. M.; Williamson, P. R.

    1984-04-01

    The paper presents some initial results on measurements of the thermal plasma environment obtained by a spherical retarding potential analyzer and a Langmuir probe flown on the third space shuttle flight ( STS-3) as part of the NASA Office of Space Science-1 (OSS-1) payload in March 1982. One of the major effects observed is a higher degree of turbulence in the ambient plasma compared to what is observed from similar instruments flown on unmanned satellites. In addition we see the temperature of the thermal electrons elevated to values of 4000-5000 K. Associated with elevated electron temperatures are regions of enhanced plasma density resulting from the appearance of high densities of molecular ions. The thermal plasma data also show clear effects of an induced V × B · L potential at the location of the probes which matches that produced by an L vector linking the probes to the engine nozzles; thereby establishing the prime return current location on the Orbiter. The final observations discussed are the pronounced and complex wake effects resulting both from the main structure of the Orbiter and from the complex shapes of appendages attached to the Orbiter.

  16. Characterization of an energy storage capacitor in abnormal thermal environments

    SciTech Connect

    Edwards, L.R.; Chen, K.C.; Baron, R.V.

    2000-01-05

    There are applications of high-voltage, energy-storage, capacitors where it is desirable that the energy storage capability can be reliably and predictably negated in abnormal environments such as fire. This property serves as a safety feature to prevent events of unintended consequence. The present paper describes studies of the thermal response characteristics of a cylindrically wound, discrete Mylar film/foil capacitor design. The experimental setups that simulate fires will be presented. Three different heat input geometries were employed: uniform radial input, spot radial input, and axial input. Heat input was controlled via feedback system to maintain specific temperature ramp rates. Both capacitor voltage and current were monitored during the thermal excursion to ascertain the failure temperature, i.e. when the capacitor permanently shorts. Temperature of failure data is presented for the three heat input cases along with a statistical analysis of the results and application implications. The physics of failure will be described in terms of the thermal/mechanical properties of the Mylar.

  17. BETEC moisture analysis tutorial [Building Environment and Thermal Envelope Council

    SciTech Connect

    Bales, E.L.; Burch, D.M.; Karagiozis, A.N.; TenWolde, A.; Trechsel, H.R.; Tsongas, G.A.

    1999-07-01

    Analytical procedures are routinely used for structural integrity of buildings, but for moisture control, designers still rely on rules of thumb, such as install vapor retarders in cold climates on the inside and in warm climates on the exterior of thermal insulation. However, cold and warm climates are ill defined, large areas of the United States have warm summers and cold winters, and the rules do not recognize the effects of other materials in the thermal envelope. Analytical methods for determining the moisture movement in building envelopes are available. These methods can predict condensation, moisture content of layers and surface relative humidities; dynamic methods also predict the duration of moisture excursions, providing a basis for moisture damage risk assessment. Recognizing that practitioners are not generally trained to use available analytical tools, the Building Environment and Thermal Envelop Council (BETEC) has developed a tutorial on moisture analysis for building designers. The tutorial consists of a Moisture Primer, an Overview of Analysis Methods, and a training session on MOIST, a dynamic model developed by the National Institute for Standards and Technology. The paper outlines the need for the analytical approach to moisture control and summarizes the three sessions.

  18. Extended Operation of Stirling Convertors in a Thermal Vacuum Environment

    NASA Technical Reports Server (NTRS)

    Oriti, Salvatore M.

    2006-01-01

    A 110 watt Stirling Radioisotope Generator (SRG110) is being developed for potential use on future NASA exploration missions. The development effort is being performed by Lockheed Martin under contract to the Department of Energy (DOE). Infinia, Corp. supplies the free-piston Stirling power convertors, and NASA Glenn Research Center (GRC) provides support to the effort in a range of technologies. This generator features higher efficiency and specific power compared to alternatives. One potential application for the generator would entail significant cruise time in the vacuum of deep space. A test has been initiated at GRC to demonstrate functionality of the Stirling convertors in a thermal vacuum environment. The test article resembles the configuration of the SRG110, however the requirement for low mass was not considered. This test demonstrates the operation of the Stirling convertors in the thermal vacuum environment, simulating deep space, over an extended period of operation. The status of the test as well as the data gathered will be presented in this paper.

  19. On thermal properties of hard rocks as a host environment of an underground thermal energy storage

    NASA Astrophysics Data System (ADS)

    Novakova, L.; Hladky, R.; Broz, M.; Novak, P.; Lachman, V.; Sosna, K.; Zaruba, J.; Metelkova, Z.; Najser, J.

    2013-12-01

    With increasing focus on environmentally friendly technologies waste heat recycling became an important issue. Under certain circumstances subsurface environment could be utilized to accommodate relatively large quantity of heat. Industrial waste heat produced during warm months can be stored in an underground thermal energy storage (UTES) and used when needed. It is however a complex task to set up a sustainable UTES for industrial scale. Number of parameters has to be studied and evaluated by means of thermohydromechanical and chemical coupling (THMC) before any UTES construction. Thermal characteristics of various rocks and its stability under thermal loading are amongst the most essential. In the Czech Republic study two complementary projects THMC processes during an UTES operation. The RESEN project (www.resen.cz) employs laboratory tests and experiments to characterise thermal properties of hard rocks in the Bohemian Massif. Aim of the project is to point out the most suitable rock environment in the Bohemian Massif for moderate to ultra-high temperature UTES construction (Sanyal, 2005). The VITA project (www.geology.cz/mokrsko) studies THM coupling in non-electrical temperature UTES using long term in-situ experiment. In both projects thermal properties of rocks were studied. Thermal conductivity and capacity were measured on rock samples. In addition an influence of increasing temperature and moisture content was considered. Ten hard rocks were investigated. The set included two sandstones, two ignibrites, a melaphyr, a syenite, two granites, a gneiss and a serpentinite. For each rock there were measured thermal conductivity and capacity of at least 54 dried samples. Subsequently, the samples were heated up to 380°C in 8 hours and left to cool down. Thermal characteristics were measured during the heating period and after the sample reached room temperature. Heating and cooling cycle was repeated 7 to 10 times to evaluate possible UTES-like degradation of

  20. Evaluating legacy contaminants and emerging chemicals in marine environments using adverse outcome pathways and biological effects-directed analysis.

    PubMed

    Hutchinson, Thomas H; Lyons, Brett P; Thain, John E; Law, Robin J

    2013-09-30

    Natural and synthetic chemicals are essential to our daily lives, food supplies, health care, industries and safe sanitation. At the same time protecting marine ecosystems and seafood resources from the adverse effects of chemical contaminants remains an important issue. Since the 1970s, monitoring of persistent, bioaccumulative and toxic (PBT) chemicals using analytical chemistry has provided important spatial and temporal trend data in three important contexts; relating to human health protection from seafood contamination, addressing threats to marine top predators and finally providing essential evidence to better protect the biodiversity of commercial and non-commercial marine species. A number of regional conventions have led to controls on certain PBT chemicals over several years (termed 'legacy contaminants'; e.g. cadmium, lindane, polycyclic aromatic hydrocarbons [PAHs] and polychlorinated biphenyls [PCBs]). Analytical chemistry plays a key role in evaluating to what extent such regulatory steps have been effective in leading to reduced emissions of these legacy contaminants into marine environments. In parallel, the application of biomarkers (e.g. DNA adducts, CYP1A-EROD, vitellogenin) and bioassays integrated with analytical chemistry has strengthened the evidence base to support an ecosystem approach to manage marine pollution problems. In recent years, however,the increased sensitivity of analytical chemistry, toxicity alerts and wider environmental awareness has led to a focus on emerging chemical contaminants (defined as chemicals that have been detected in the environment, but which are currently not included in regulatory monitoring programmes and whose fate and biological impacts are poorly understood). It is also known that natural chemicals (e.g. algal biotoxins) may also pose a threat to marine species and seafood quality. Hence complex mixtures of legacy contaminants, emerging chemicals and natural biotoxins in marine ecosystems represent

  1. Degradation of thermal shield materials in the space radiation environment

    NASA Astrophysics Data System (ADS)

    Shimoji, S.; Kimura, H.; Koitabashi, M.; Imamura, T.; Kasai, R.; Matsushita, M.

    1983-12-01

    Changes in temperature distribution data of Experimental Technology Satellite 4 after its 3 months mission term are discussed. Analysis of the data suggested that the thermal shields loose their function in the space radiation environment. The effect of energetic particles on the shield materials was investigated. Electron beams of 500 keV and proton beams of 900 keV were irradiated on silver-Teflon and aluminized Kapton films. The fluences were changed between 10 to the 14th and 10 to the 16th power sqcm. Temperature varied between -100 and 100C. Solar absorptance, infrared emittance, tensile strength and elongation rate were measured. Thermogravimetry, infrared spectroscopy and X-ray diffraction were performed. Electron fluxes have remarkable effects on the mechanical properties, proton fluxes on the thermophysical properties of silver-Teflon film. Kapton films do not change much.

  2. Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

    NASA Technical Reports Server (NTRS)

    Bradley, D. E.; Mireles, O. R.; Hickman, R. R.

    2011-01-01

    Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames.1,2 Conventional storable propellants produce average specific impulse. Nuclear thermal rockets capable of producing high specific impulse are proposed. Nuclear thermal rockets employ heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K), and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited.3 The primary concern is the mechanical failure of fuel elements that employ high-melting-point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. The purpose of the testing is to obtain data to assess the properties of the non-nuclear support materials, as-fabricated, and determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures. The fission process of the planned fissile material and the resulting heating performance is well known and does not therefore require that active fissile material be integrated in this testing. A small-scale test bed designed to heat fuel element samples via non-contact radio frequency heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

  3. [Physiological and hygienic rationale for the duration of exposure to the heating environment and comfortable thermal conditions during a workshift].

    PubMed

    Afanas'eva, R F; Bessonova, N A

    2011-01-01

    The strain in different functional systems of human body maintaining thermal homeostasis that develops during work under heating conditions results in impaired working capacity and efficiency and may be harmful to health. One of the most efficacious measures is the reduction of exposure to the adverse conditions and its rational alternation with rest in the comfortable environment. Based on the mathematical and statistical analysis of the results of multiple-factor experiments, we derived a multiple regression equation describing the quantitative dependence of the integral index of human body thermal regime on the totality of factors responsible for thermal strain. The equation permits to determine the heat content in the human body formed by exothermal and endothermal strain, to estimate the contribution of each individual factor, and to predict the risk of overheating in order to take measures for reducing the thermal strain. Recommendations are proposed on the duration of thermal exposure during a workshift depending on the overheating risk level and on the optimal relationship between the duration of staying in the heating microclimate and the duration of the rest (work) in the comfortable environment. PMID:21544934

  4. Effect of the environmental stimuli upon the human body in winter outdoor thermal environment.

    PubMed

    Kurazumi, Yoshihito; Kondo, Emi; Ishii, Jin; Sakoi, Tomonori; Fukagawa, Kenta; Bolashikov, Zhecho Dimitrov; Tsuchikawa, Tadahiro; Matsubara, Naoki; Horikoshi, Tetsumi

    2013-01-01

    In order to manage the outdoor thermal environment with regard to human health and the environmental impact of waste heat, quantitative evaluations are indispensable. It is necessary to use a thermal environment evaluation index. The purpose of this paper is to clarify the relationship between the psychological thermal responses of the human body and winter outdoor thermal environment variables. Subjective experiments were conducted in the winter outdoor environment. Environmental factors and human psychological responses were measured. The relationship between the psychological thermal responses of the human body and the outdoor thermal environment index ETFe (enhanced conduction-corrected modified effective temperature) in winter was shown. The variables which influence the thermal sensation vote of the human body are air temperature, long-wave thermal radiation and short-wave solar radiation. The variables that influence the thermal comfort vote of the human body are air temperature, humidity, short-wave solar radiation, long-wave thermal radiation, and heat conduction. Short-wave solar radiation, and heat conduction are among the winter outdoor thermal environment variables that affect psychological responses to heat. The use of thermal environment evaluation indices that comprise short-wave solar radiation and heat conduction in winter outdoor spaces is a valid approach. PMID:23861691

  5. Effect of the Environmental Stimuli upon the Human Body in Winter Outdoor Thermal Environment

    PubMed Central

    Kurazumi, Yoshihito; Kondo, Emi; Ishii, Jin; Sakoi, Tomonori; Fukagawa, Kenta; Bolashikov, Zhecho Dimitrov; Tsuchikawa, Tadahiro; Matsubara, Naoki; Horikoshi, Tetsumi

    2013-01-01

    In order to manage the outdoor thermal environment with regard to human health and the environmental impact of waste heat, quantitative evaluations are indispensable. It is necessary to use a thermal environment evaluation index. The purpose of this paper is to clarify the relationship between the psychological thermal responses of the human body and winter outdoor thermal environment variables. Subjective experiments were conducted in the winter outdoor environment. Environmental factors and human psychological responses were measured. The relationship between the psychological thermal responses of the human body and the outdoor thermal environment index ETFe (enhanced conduction-corrected modified effective temperature) in winter was shown. The variables which influence the thermal sensation vote of the human body are air temperature, long-wave thermal radiation and short-wave solar radiation. The variables that influence the thermal comfort vote of the human body are air temperature, humidity, short-wave solar radiation, long-wave thermal radiation, and heat conduction. Short-wave solar radiation, and heat conduction are among the winter outdoor thermal environment variables that affect psychological responses to heat. The use of thermal environment evaluation indices that comprise short-wave solar radiation and heat conduction in winter outdoor spaces is a valid approach. PMID:23861691

  6. Thermal adaptability of large white pigs in the tropical environment

    NASA Astrophysics Data System (ADS)

    Dede, T. I.

    1983-09-01

    Twenty-four Large White weaners-twelve males and twelve females, were randomly divided into three groups of eight (four males and four females per two separate pens) and were assigned to three groups of two pens each for the males and the females weaners. One group of two pens was without wallow facility (control), one other group was provided with wallows (wet) and the third group was in air-conditioned room (cold). Twice a day, the respiratory rate and the rectal temperatures were measured early in the mornings at 8.00 9.00 hrs (A.M.) and late in the early evenings at 16.00 18.00 hrs. The mean respiratory frequency (A.M) ranged from 7 to 9; 6 12 and 8 13 breaths per minute for the cold, wet and control respectively while the mean respiratory frequency (P.M.) ranged from 6 to 9, 10 to 17 and 13 to 19 breaths per minute for the cold, wet and control respectively. The mean rectal temperatures (A.M.) ranged very slightly from 38.54° to 39.12°C; 38.50° to 39.05°C and 38.61°C to 39°C for the cold, wet as control respectively while the mean rectal temperatures (P.M.) ranged from 39.00° to 39.22°C; 38.97° to 39.29°C and 39.28° to 39.55°C for the cold, wet and control respectively. The animals were maintained for another seven to ten weeks and were slaughtered. The slaughter characteristics did not indicate an appreciable thermal stress except for the reproductive organs which showed weight increase indicating reduced efficiency of the thermally stressed animals as is the case in the tropical environment.

  7. Culture as a mediator of gene-environment interaction: Cultural consonance, childhood adversity, a 2A serotonin receptor polymorphism, and depression in urban Brazil.

    PubMed

    Dressler, William W; Balieiro, Mauro C; Ferreira de Araújo, Luiza; Silva, Wilson A; Ernesto Dos Santos, José

    2016-07-01

    Research on gene-environment interaction was facilitated by breakthroughs in molecular biology in the late 20th century, especially in the study of mental health. There is a reliable interaction between candidate genes for depression and childhood adversity in relation to mental health outcomes. The aim of this paper is to explore the role of culture in this process in an urban community in Brazil. The specific cultural factor examined is cultural consonance, or the degree to which individuals are able to successfully incorporate salient cultural models into their own beliefs and behaviors. It was hypothesized that cultural consonance in family life would mediate the interaction of genotype and childhood adversity. In a study of 402 adult Brazilians from diverse socioeconomic backgrounds, conducted from 2011 to 2014, the interaction of reported childhood adversity and a polymorphism in the 2A serotonin receptor was associated with higher depressive symptoms. Further analysis showed that the gene-environment interaction was mediated by cultural consonance in family life, and that these effects were more pronounced in lower social class neighborhoods. The findings reinforce the role of the serotonergic system in the regulation of stress response and learning and memory, and how these processes in turn interact with environmental events and circumstances. Furthermore, these results suggest that gene-environment interaction models should incorporate a wider range of environmental experience and more complex pathways to better understand how genes and the environment combine to influence mental health outcomes. PMID:27270123

  8. The effect of environment on thermal barrier coating lifetime

    DOE PAGESBeta

    Pint, Bruce A.; Unocic, Kinga A.; Haynes, James Allen

    2016-03-15

    While the water vapor content of the combustion gas in natural gas-fired land-based turbines is ~10%, it can be 20–85% with coal-derived (syngas or H2) fuels or innovative turbine concepts for more efficient carbon capture. Additional concepts envisage working fluids with high CO2 contents to facilitate carbon capture and sequestration. To investigate the effects of changes in the gas composition on thermal barrier coating (TBC) lifetime, furnace cycling tests (1-h and 100-h cycles) were performed in air with 10, 50, and 90 vol. % water vapor and CO2-10% H2O and compared to prior results in dry air or O2. Twomore » types of TBCs were investigated: (1) diffusion bond coatings (Pt-diffusion or Pt-modified aluminide) with commercial electron-beam physical vapor-deposited yttria-stabilized zirconia (YSZ) top coatings on second-generation superalloy N5 and N515 substrates and (2) high-velocity oxygen fuel (HVOF) sprayed MCrAlYHfSi bond coatings with air plasma-sprayed YSZ top coatings on superalloys X4, 1483, or 247 substrates. For both types of coatings exposed in 1-h cycles, the addition of water vapor resulted in a decrease in coating lifetime, except for Pt-diffusion coatings which were unaffected by the environment. In 100-h cycles, environment was less critical, perhaps because coating failure was chemical (i.e., due to interdiffusion) rather than mechanical. As a result, in both 1-h and 100-h cycles, CO2 did not appear to have any negative effect on coating lifetime.« less

  9. UKIRT Upgrades Program: control of the telescope thermal environment

    NASA Astrophysics Data System (ADS)

    Cavedoni, Charles P.; Hawarden, Timothy G.; Chuter, Timothy C.; Look, I. A.

    1997-03-01

    The control of the telescope thermal environment at the 3.8-m United Kingdom Infrared Telescope (UKIRT) is based on the requirements that dome seeing should not degrade the image quality by more than 0.05 arcsec (FWHM) and that mirror seeing should be reduced to negligible proportions. After quantifying steady state and transient heat flow around and through the building, we set out on a program to meet these requirements. Major telescope enclosure upgrades to address dome seeing include natural dome ventilation with 16 apertures in the base of the dome and for near still-air nights, forced-air ventilation via the plant room exhaust system. To address mirror seeing, we are in the process of installing a day-time mirror cooling system that can drive and/or keep the primary mirror between 0 degrees Celsius and 2.5 degrees Celsius colder than the predicted night-time local dome air temperature. Nevertheless, during the night, if the primary mirror is warmer than the local dome air, a flushing system is available to blow away warm convective air cells as they form. This paper describes design considerations of the natural dome ventilation system (DVS), the hardware of the primary mirror cooling and flushing system and the performance of the mirror flushing system on a dummy mirror segment.

  10. Frequency stabilization of laser diodes in an aggressive thermal environment

    NASA Astrophysics Data System (ADS)

    Minch, J. R.; Walther, F. G.; Savage, S.; Plante, A.; Scalesse, V.

    2015-03-01

    Mobile free-space laser communication systems must reconcile the requirements of low size, weight, and power with the ability to both survive and operate in harsh thermal and mechanical environments. In order to minimize the aperture size and amplifier power requirements of such systems, communication links must exhibit performance near theoretical limits. Such performance requires laser transmitters and receiver filters and interferometers to maintain frequency accuracy to within a couple hundred MHz of the design frequency. We demonstrate an approach to achieving high frequency stability over wide temperature ranges by using conventional DFB lasers, tuned with TEC and current settings, referenced to an HCN molecular frequency standard. A HCN cell absorption line is scanned across the TEC set-point to adjust the DFB laser frequency. Once the center of the line is determined, the TEC set-point is offset as required to obtain frequency agility. To obtain large frequency offsets from an HCN absorption line, as well as continuous laser source operation, a second laser is offset from the reference laser and the resulting beat tone is detected in a photoreceiver and set to the desired offset using a digital frequency-locked loop. Using this arrangement we have demonstrated frequency accuracy and stability of better than 8 MHz RMS over an operational temperature range of 0ºC to 50º C, with operation within minutes following 8 hour soaks at -40º C and 70º C.

  11. Nonlinear dynamical effects on reaction rates in thermally fluctuating environments.

    PubMed

    Kawai, Shinnosuke; Komatsuzaki, Tamiki

    2010-07-21

    A framework to calculate the rate constants of condensed phase chemical reactions of manybody systems is presented without relying on the concept of transition state. The theory is based on a framework we developed recently adopting a multidimensional underdamped Langevin equation in the region of a rank-one saddle. The theory provides a reaction coordinate expressed as an analytical nonlinear functional of the position coordinates and velocities of the system (solute), the friction constants, and the random force of the environment (solvent). Up to moderately high temperature, the sign of the reaction coordinate can determine the final destination of the reaction in a thermally fluctuating media, irrespective of what values the other (nonreactive) coordinates may take. In this paper, it is shown that the reaction probability is analytically derived as the probability of the reaction coordinate being positive, and that the integration with the Boltzmann distribution of the initial conditions leads to the exact reaction rate constant when the local equilibrium holds and the quantum effect is negligible. Because of analytical nature of the theory taking into account all nonlinear effects and their combination with fluctuation and dissipation, the theory naturally provides us with the firm mathematical foundation of the origin of the reactivity of the reaction in a fluctuating media. PMID:20544104

  12. Low Thermal Conductivity, High Durability Thermal Barrier Coatings for IGCC Environments

    SciTech Connect

    Jordan, Eric; Gell, Maurice

    2015-01-15

    Advanced thermal barrier coatings (TBC) are crucial to improved energy efficiency in next generation gas turbine engines. The use of traditional topcoat materials, e.g. yttria-stabilized zirconia (YSZ), is limited at elevated temperatures due to (1) the accelerated undesirable phase transformations and (2) corrosive attacks by calcium-magnesium-aluminum-silicate (CMAS) deposits and moisture. The first goal of this project is to use the Solution Precursor Plasma Spray (SPPS) process to further reduce the thermal conductivity of YSZ TBCs by introducing a unique microstructural feature of layered porosity, called inter-pass boundaries (IPBs). Extensive process optimization accompanied with hundreds of spray trials as well as associated SEM cross-section and laser-flash measurements, yielded a thermal conductivity as low as 0.62 Wm⁻¹K⁻¹ in SPPS YSZ TBCs, approximately 50% reduction of APS TBCs; while other engine critical properties, such as cyclic durability, erosion resistance and sintering resistance, were characterized to be equivalent or better than APS baselines. In addition, modifications were introduced to SPPS TBCs so as to enhance their resistance to CMAS under harsh IGCC environments. Several mitigation approaches were explored, including doping the coatings with Al₂O₃ and TiO₂, applying a CMAS infiltration-inhibiting surface layer, and filling topcoat cracks with blocking substances. The efficacy of all these modifications was assessed with a set of novel CMAS-TBC interaction tests, and the moisture resistance was tested in a custom-built high-temperature moisture rig. In the end, the optimal low thermal conductivity TBC system was selected based on all evaluation tests and its processing conditions were documented. The optimal coating consisted on a thick inner layer of YSZ coating made by the SPPS process having a thermal conductivity 50% lower than standard YSZ coatings topped with a high temperature tolerant CMAS resistant gadolinium

  13. Efficiency of supercritical fluid chromatography columns in different thermal environments.

    PubMed

    Kaczmarski, Krzysztof; Poe, Donald P; Tarafder, Abhijit; Guiochon, Georges

    2013-05-24

    The efficiency of a packed column eluted with supercritical carbon dioxide at 323K and outlet pressures from 90 to 150bar was studied with the column in two different thermal environments. The 150mm×2.0mm ID stainless steel column was packed with spherical 5-μm porous silica particles with a covalently bonded nonpolar stationary phase, and the test solutes were normal alkanes. When operated in a convective air bath the column exhibited severe efficiency losses when its outlet pressure was below 120bar. The efficiency of the same column enclosed in a shell made of foam insulation was restored at low outlet pressures down to 100bar. The van Deemter plots showed an abnormal dependence of the plate height (HETP) on the flow rate at low outlet pressures, exhibiting a maximum in the HETP at flow rates around 1mL/min and a 20-bar pressure drop. The large efficiency losses at low outlet pressures are due to radial temperature gradients associated with enthalpic expansion and cooling of the mobile phase. The separations were simulated by a numerical model that accounts for axial and radial gradients in the temperature and density along the column. The abnormal van Deemter plots arise from competing processes affecting the radial distribution of the solute migration velocity along the column. The negative impact on efficiency is greatest when the density profile of the mobile phase along the column is close to the critical isopycnic line. The efficiency improves at increased flow rates because of increased cooling at larger pressure drops and increased density along the entire length of the column. The model predicts the unusual trends in the van Deemter plots, but the calculated results at low outlet pressures are strongly influenced by small variations in the porosity distribution in the column, limiting the accuracy of the predicted HETP values. In spite of these difficulties, the model has enabled a detailed analysis of the effects of temperature, pressure and flow

  14. The Universal Thermal Climate Index UTCI compared to ergonomics standards for assessing the thermal environment.

    PubMed

    Bröde, Peter; Błazejczyk, Krzysztof; Fiala, Dusan; Havenith, George; Holmér, Ingvar; Jendritzky, Gerd; Kuklane, Kalev; Kampmann, Bernhard

    2013-01-01

    The growing need for valid assessment procedures of the outdoor thermal environment in the fields of public weather services, public health systems, urban planning, tourism & recreation and climate impact research raised the idea to develop the Universal Thermal Climate Index UTCI based on the most recent scientific progress both in thermo-physiology and in heat exchange theory. Following extensive validation of accessible models of human thermoregulation, the advanced multi-node 'Fiala' model was selected to form the basis of UTCI. This model was coupled with an adaptive clothing model which considers clothing habits by the general urban population and behavioral changes in clothing insulation related to actual environmental temperature. UTCI was developed conceptually as an equivalent temperature. Thus, for any combination of air temperature, wind, radiation, and humidity, UTCI is defined as the air temperature in the reference condition which would elicit the same dynamic response of the physiological model. This review analyses the sensitivity of UTCI to humidity and radiation in the heat and to wind in the cold and compares the results with observational studies and internationally standardized assessment procedures. The capabilities, restrictions and potential future extensions of UTCI are discussed. PMID:23411753

  15. Meta-analysis of the serotonin transporter promoter variant (5-HTTLPR) in relation to adverse environment and antisocial behavior.

    PubMed

    Tielbeek, Jorim J; Karlsson Linnér, Richard; Beers, Koko; Posthuma, Danielle; Popma, Arne; Polderman, Tinca J C

    2016-07-01

    Several studies have suggested an association between antisocial, aggressive, and delinquent behavior and the short variant of the serotonin transporter gene polymorphism (5-HTTLPR). Yet, genome wide and candidate gene studies in humans have not convincingly shown an association between these behaviors and 5-HTTLPR. Moreover, individual studies examining the effect of 5-HTTLPR in the presence or absence of adverse environmental factors revealed inconsistent results. We therefore performed a meta-analysis to test for the robustness of the potential interaction effect of the "long-short" variant of the 5-HTTLPR genotype and environmental adversities, on antisocial behavior. Eight studies, comprising of 12 reasonably independent samples, totaling 7,680 subjects with an effective sample size of 6,724, were included in the meta-analysis. Although our extensive meta-analysis resulted in a significant interaction effect between the 5-HTTLPR genotype and environmental adversities on antisocial behavior, the methodological constraints of the included studies hampered a confident interpretation of our results, and firm conclusions regarding the direction of effect. Future studies that aim to examine biosocial mechanisms that influence the etiology of antisocial behavior should make use of larger samples, extend to genome-wide genetic risk scores and properly control for covariate interaction terms, ensuring valid and well-powered research designs. © 2016 Wiley Periodicals, Inc. PMID:26990155

  16. A Longitudinal Assessment of Associations between Adolescent Environment, Adversity Perception, and Economic Status on Fertility and Age of Menarche

    PubMed Central

    Amir, Dorsa; Jordan, Matthew R.; Bribiescas, Richard G.

    2016-01-01

    Purpose Perceptions of environmental adversity and access to economic resources in adolescence can theoretically affect the timing of life history transitions and investment in reproductive effort. Here we present evidence of correlations between variables associated with subjective extrinsic mortality, economic status, and reproductive effort in a nationally representative American population of young adults. Methods We used a longitudinal database that sampled American participants (N ≥ 1,579) at four points during early adolescence and early adulthood to test whether perceptions of environmental adversity and early economic status were associated with reproductive effort. Results We found that subjectively high ratings of environmental danger and low access to economic resources in adolescence were significantly associated with an earlier age of menarche in girls and earlier, more robust fertility in young adulthood. Conclusion While energetics and somatic condition remain as possible sources of variation, the results of this study support the hypothesis that perceptions of adversity early in life and limited access to economic resources are associated with differences in reproductive effort and scheduling. How these factors may covary with energetics and somatic condition merits further investigation. PMID:27249338

  17. Genetic variants determining survival and fertility in an adverse African environment: a population-based large-scale candidate gene association study

    PubMed Central

    Koopman, Jacob J.E.; Pijpe, Jeroen; Böhringer, Stefan; van Bodegom, David; Eriksson, Ulrika K.; Sanchez-Faddeev, Hernando; Ziem, Juventus B.; Zwaan, Bas; Slagboom, P. Eline; de Knijff, Peter; Westendorp, Rudi G.J.

    2016-01-01

    Human survival probability and fertility decline strongly with age. These life history traits have been shaped by evolution. However, research has failed to uncover a consistent genetic determination of variation in survival and fertility. As an explanation, such genetic determinants have been selected in adverse environments, in which humans have lived during most of their history, but are almost exclusively studied in populations in modern affluent environments. Here, we present a large-scale candidate gene association study in a rural African population living in an adverse environment. In 4387 individuals, we studied 4052 SNPs in 148 genes that have previously been identified as possible determinants of survival or fertility in animals or humans. We studied their associations with survival comparing newborns, middle-age adults, and old individuals. In women, we assessed their associations with reported and observed numbers of children. We found no statistically significant associations of these SNPs with survival between the three age groups nor with women's reported and observed fertility. Population stratification was unlikely to explain these results. Apart from a lack of power, we hypothesise that genetic heterogeneity of complex phenotypes and gene-environment interactions prevent the identification of genetic variants explaining variation in survival and fertility in humans. PMID:27356285

  18. Heat and Mass Transport from Thermally Degrading Thin Cellulosic Materials in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Kushida, G.; Baum, H. R.; Kashiwagi, T.; Di Blasi, C.

    1992-01-01

    Attention is given to a theoretical model describing the behavior of a thermally thin cellulosic sheet heated by external thermal radiation in a quiescent microgravity environment. This model describes thermal and oxidative degradation of the sheet and the heat and mass transfer of evolved degradation products from the heated cellulosic surface into the gas phase. Two calculations are carried out: heating without thermal degradation, and heating with thermal degradation of the sheet with endothermic pyrolysis, exothermic thermal oxidative degradation, and highly exothermic char oxidation. It is shown that pyrolysis is the main degradation reaction. Self-sustained smoldering is controlled and severely limited by the reduced oxygen supply.

  19. Woven Thermal Protection System (Woven TPS) for Extreme Entry Environments

    NASA Video Gallery

    The Woven Thermal Protection System (WTPS) project explores an innovative way to design, develop and manufacture a family of ablative TPS materials using weaving technology and testing them in the ...

  20. Thermal contact electronic packaging in solar pointing space environment

    SciTech Connect

    Colangelo, A.M. ); McKim, G.S. . Space Systems Div.)

    1991-02-01

    A thermal design for a solar pointing space shuttle mission is presented. The apparatus, which will measure solar flux intensity variations, contains sensors and data acquisition electronics which must be maintained within certain temperature constraints. The thermal design, which utilizes parallel heat flow paths and conduction fins to reject dissipated heat, is shown by finite difference thermal modeling to maintain component temperatures within these constraints. In the thermal modeling, arithmetic nodes are used to represent surface radiosity for radiation heat transfer. Also, the concept of mean fin conduction length and effective fin capacitance are introduced as means of simplifying the model representation of the conduction fins. An experiment was conducted to evaluate the chip/fin contact conductance.

  1. Thermal physiology in a changing thermal world

    PubMed Central

    Horowitz, Michal; Kenny, Glen P; McAllen, Robin M; van Marken Lichtenbelt, Wouter D

    2015-01-01

    This editorial focuses on articles submitted to the Temperature call “Thermal Physiology in a Changing Thermal World.” It highlights an array of topics related to thermoregulatory and metabolic functions in adverse environments, and the complexity and adaptability of the systems to changing climatic conditions, at various levels of body organization. PMID:27226998

  2. Gaussian entanglement induced by an extended thermal environment

    NASA Astrophysics Data System (ADS)

    Valido, Antonio A.; Alonso, Daniel; Kohler, Sigmund

    2013-10-01

    We study stationary entanglement between three harmonic oscillators which are dipole coupled to a one-dimensional or a three-dimensional bosonic environment. The analysis of the open-system dynamics is performed with generalized quantum Langevin equations which we solve exactly in a Fourier representation. The focus lies on Gaussian bipartite and tripartite entanglement induced by the highly non-Markovian interaction mediated by the environment. This environment-induced interaction represents an effective many-party interaction with a spatial long-range feature: A main finding is that the presence of a passive oscillator is detrimental for stationary two-mode entanglement. Furthermore, our results indicate that the environment-induced entanglement mechanism corresponds to uncontrolled feedback which is predominantly coherent at low temperatures and for moderate oscillator-environment coupling as compared to the oscillator frequency.

  3. Thermal contact conductance between metals in a vacuum environment

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Basic heat transfer data for structural materials used in the Saturn 1B/V 1U component case structural design were obtained. The main emphasis is on thermal contact conductance between dissimilar metallic surfaces, since thermal conductivity values within solids have been sufficiently established previously. The test program outline and test results are described. The following materials were tested: aluminum 6061-T6 (12 samples), aluminum 356 (as cast), almag 35 (as cast), magnesium AZ91C-T4 (4 samples), and mag lithium LA-141 (2 samples).

  4. Characterization factors for thermal pollution in freshwater aquatic environments.

    PubMed

    Verones, Francesca; Hanafiah, Marlia Mohd; Pfister, Stephan; Huijbregts, Mark A J; Pelletier, Gregory J; Koehler, Annette

    2010-12-15

    To date the impact of thermal emissions has not been addressed in life cycle assessment despite the narrow thermal tolerance of most aquatic species. A method to derive characterization factors for the impact of cooling water discharges on aquatic ecosystems was developed which uses space and time explicit integration of fate and effects of water temperature changes. The fate factor is calculated with a 1-dimensional steady-state model and reflects the residence time of heat emissions in the river. The effect factor specifies the loss of species diversity per unit of temperature increase and is based on a species sensitivity distribution of temperature tolerance intervals for various aquatic species. As an example, time explicit characterization factors were calculated for the cooling water discharge of a nuclear power plant in Switzerland, quantifying the impact on aquatic ecosystems of the rivers Aare and Rhine. The relative importance of the impact of these cooling water discharges was compared with other impacts in life cycle assessment. We found that thermal emissions are relevant for aquatic ecosystems compared to other stressors, such as chemicals and nutrients. For the case of nuclear electricity investigated, thermal emissions contribute between 3% and over 90% to Ecosystem Quality damage. PMID:21069953

  5. Thermal Testing of Woven TPS Materials in Extreme Entry Environments

    NASA Astrophysics Data System (ADS)

    Gonzales, G.

    2014-06-01

    Some recent thermal tests of woven TPS have been used to help develop and qualify the capabilities of the NASA's IHF and AEDC's H3 arcjet facilities and this woven material. These tests have benefited both the facilities and woven teams.

  6. Entanglement evolution of a two-mode Gaussian system in various thermal environments

    SciTech Connect

    Mihaescu, Tatiana Isar, Aurelian

    2015-12-07

    We describe the evolution of the quantum entanglement of an open system consisting of two bosonic modes interacting with a common thermal environment, described by two different models. The initial state of the system is taken of Gaussian form. In the case of a thermal bath, characterized by temperature and dissipation constant which correspond to an asymptotic Gibbs state of the system, we show that for a zero temperature of the thermal bath an initial entangled Gaussian state remains entangled for all finite times. For an entangled initial squeezed thermal state, the phenomenon of entanglement sudden death takes place and we calculate the survival time of entanglement. For the second model of the environment, corresponding to a non-Gibbs asymptotic state, we study the possibility of generating entanglement. We show that the generation of the entanglement between two uncoupled bosonic modes is possible only for definite values of the temperature and dissipation constant, which characterize the thermal environment.

  7. Entanglement evolution of a two-mode Gaussian system in various thermal environments

    NASA Astrophysics Data System (ADS)

    Mihaescu, Tatiana; Isar, Aurelian

    2015-12-01

    We describe the evolution of the quantum entanglement of an open system consisting of two bosonic modes interacting with a common thermal environment, described by two different models. The initial state of the system is taken of Gaussian form. In the case of a thermal bath, characterized by temperature and dissipation constant which correspond to an asymptotic Gibbs state of the system, we show that for a zero temperature of the thermal bath an initial entangled Gaussian state remains entangled for all finite times. For an entangled initial squeezed thermal state, the phenomenon of entanglement sudden death takes place and we calculate the survival time of entanglement. For the second model of the environment, corresponding to a non-Gibbs asymptotic state, we study the possibility of generating entanglement. We show that the generation of the entanglement between two uncoupled bosonic modes is possible only for definite values of the temperature and dissipation constant, which characterize the thermal environment.

  8. Thermal enclosures for electronically scanned pressure modules operating in cryogenic environments

    NASA Technical Reports Server (NTRS)

    Mitchell, Michael; Sealey, Bradley S.

    1989-01-01

    Specific guidelines to design, construct, and test ESP thermal enclosures for applications at cryogenic temperatures are given. The enclosures maintain the ESP modules at a constant temperature (10 C plus or minus 1 C) to minimize thermal zero and sensitivity shifts, to minimize the frequency of expensive on-line calibrations, and to avoid adverse effects on tunnel and model boundary layers. The enclosures are constructed of a rigid closed-cell foam and are capable of withstanding the stagnation pressures to 932kPa (135 psia) without reduction in thermal insulation properties. This construction procedure has been used to construct several thermal packages which have been successfully used in National Transonic Facility.

  9. That Elusive, Eclectic Thing Called Thermal Environment: What a Board Should Know About It

    ERIC Educational Resources Information Center

    Schutte, Frederick

    1970-01-01

    Discussion of proper thermal environment for protection of sophisticated educational equipment such as computer and data-processing machines, magnetic tapes, closed-circuit television and video tape communications systems.

  10. Thermal Neutron Imaging in an Active Interrogation Environment

    SciTech Connect

    Vanier, Peter E.; Forman, Leon; Norman, Daren R.

    2009-03-10

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutron-emitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  11. Thermal neutron imaging in an active interrogation environment

    SciTech Connect

    Vanier,P.E.; Forman, L., and Norman, D.R.

    2009-03-10

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of xcitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  12. The effect of adverse rearing environments on persistent memories in young rats: removing the brakes on infant fear memories.

    PubMed

    Callaghan, B L; Richardson, R

    2012-01-01

    Mental health problems are often assumed to have their roots in early-life experiences. However, memories acquired in infancy are rapidly forgotten in nearly all species (including humans). As yet, a testable mechanism on how early-life experiences have a lasting impact on mental health is lacking. In these experiments, we tested the idea that infant adversity leads to an early transition into adult-like fear retention, allowing infant memories to have a longer-lasting influence. Rats were exposed to maternal separation (3 h per day) across postnatal days (P) 2-14, or their mother was given corticosterone in her drinking water across the same period. Infant rats were then trained to fear a conditioned stimulus (CS) paired with an aversive unconditioned stimulus (US) on P17. Retention of the fear association was then tested 1-55 days later. When tested one day after the CS-US association was formed, both standard-reared (SR) and maternally-separated (MS) rats exhibited strong memory. However, when tested 10 days later, SR rats exhibited robust forgetting, whereas MS rats exhibited near-perfect retention. These effects were mimicked by exposing the mother to the stress hormone corticosterone in the drinking water. Finally, fear associations in P17 MS rats were retained for up to 30 days. Our findings point to differences in retention of fear as one factor that might underlie the propensity of stress-exposed individuals to exhibit early anxiety symptoms and suggest that manipulations of the corticosterone system may hold the key to ameliorating some of the effects of early stress on persistent retention of fear. PMID:22781171

  13. Thermal Analysis--Human Comfort--Indoor Environments. NBS Special Publication 491.

    ERIC Educational Resources Information Center

    Mangum, Billy W., Ed.; Hill, James E., Ed.

    Included in these proceedings are 11 formal papers presented by leading researchers in the field of thermal comfort and heat stress at a symposium held for the purpose of exploring new aspects of indoor thermal environments, caused primarily by the impact of energy conservation in new and existing buildings. The contributed papers were from…

  14. Thermal Testing of Woven TPS Materials in Extreme Entry Environments

    NASA Technical Reports Server (NTRS)

    Gonzales, G.; Stackpoole, M.

    2014-01-01

    NASAs future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heatshield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust TPS however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, high pressures and short entry durations, in order for CP to be feasible from a mass perspective. In 2012 the Game Changing Development Program in NASAs Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System to meet the needs of NASAs most challenging entry missions. The high entry conditions pose certification challenges in existing ground based test facilities. Recent updates to NASAs IHF and AEDCs H3 high temperature arcjet test facilities enable higher heatflux (2000 Wcm2) and high pressure (5 atm) testing of TPS. Some recent thermal tests of woven TPS will be discussed in this paper. These upgrades have provided a way to test higher entry conditions of potential outer planet and Venus missions and provided a baseline against carbon phenolic material. The results of these tests have given preliminary insight to sample configuration and physical recession profile characteristics.

  15. Chapter 5: Thermal Indices and Their Applications for Livestock Environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat exchanges with the environment are a crucial process for maintaining homeothermy by humans and other animals. These exchanges involve heat production, conservation and dissipation, and are dependent on both biological and physical factors. The complexity of these exchanges has led to many attem...

  16. Controlling the Thermal Environment of the Co-ordinated Classroom.

    ERIC Educational Resources Information Center

    Harmon, Darell Boyd

    The classroom environment is a working surround in which children, through participating in organized experiences, can grow and develop in an optimum manner. Classroom design requires organization of principles of environmental control in order to assure efficient and successful performance. This control cannot be left to chance. In considering…

  17. Response of largemouth bass (Micropterus salmoides) from different thermal environments to increased water temperature.

    PubMed

    Mulhollem, Joshua J; Suski, Cory D; Wahl, David H

    2015-08-01

    Due to concerns of global climate change, additional research is needed to quantify the thermal tolerance of species, and how organisms are able to adapt to changes in thermal regime. We quantified the thermal tolerance and thermal stress response of a temperate sportfish from two different thermal environments. One group of largemouth bass (Micropterus salmoides) inhabited thermally enhanced reservoirs (used for power plant cooling), with water temperatures typically 2-5°C warmer than nearby reservoirs. We tested fish for chronic thermal maxima and reaction to an 8°C heat shock using three common physiological indices of stress. We observed no evidence of differences between groups in thermal maxima. We observed no differences in thermal maxima between fish from artificially warmed and natural systems. Our results disagree with research, suggesting differences due to adaptation to different thermal environments. We speculate that behavioral modifications, lack of adequate time for genetic divergence, or the robust genetic plasticity of largemouth bass explain the lack of difference between treatment groups. PMID:25869216

  18. Coatings in space environment. [for satellite thermal control

    NASA Technical Reports Server (NTRS)

    Triolo, J. J.; Heaney, J. B.; Hass, G.

    1978-01-01

    The behavior in space environment of evaporated Al uncoated and coated with reactively deposited silicon oxide (SiOx), electron beam evaporated SiO2 and Al2O3, and Al and Ag coated with double layers of Al2O3 + SiOx is compared with metallized Teflon and Kapton, anodized Al (Alzak), and white paints. Flight data from three calorimetric experiments and one reflectometer flown in different orbital environments are compared with laboratory test data. The results demonstrate that evaporated thin films are extremely versatile and stable coatings for space applications. Through the use of control samples studied in different laboratory tests and monitored for up to 12,000 hours of solar exposure in different orbits, a classification of orbital severity and an estimate of laboratory simulation accuracy is obtained.

  19. Layerwise Finite Elements for Smart Piezoceramic Composite Plates in Thermal Environments

    NASA Technical Reports Server (NTRS)

    Saravanos, Dimitris A.; Lee, Ho-Jun

    1996-01-01

    Analytical formulations are presented which account for the coupled mechanical, electrical, and thermal response of piezoelectric composite laminates and plate structures. A layerwise theory is formulated with the inherent capability to explicitly model the active and sensory response of piezoelectric composite plates having arbitrary laminate configurations in thermal environments. Finite element equations are derived and implemented for a bilinear 4-noded plate element. Application cases demonstrate the capability to manage thermally induced bending and twisting deformations in symmetric and antisymmetric composite plates with piezoelectric actuators, and show the corresponding electrical response of distributed piezoelectric sensors. Finally, the resultant stresses in the thermal piezoelectric composite laminates are investigated.

  20. Prediction of the thermal environment and thermal response of simple panels exposed to radiant heat

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.; Ash, Robert L.

    1989-01-01

    A method of predicting the radiant heat flux distribution produced by a bank of tubular quartz heaters was applied to a radiant system consisting of a single unreflected lamp irradiating a flat metallic incident surface. In this manner, the method was experimentally verified for various radiant system parameter settings and used as a source of input for a finite element thermal analysis. Two finite element thermal analyses were applied to a thermal system consisting of a thin metallic panel exposed to radiant surface heating. A two-dimensional steady-state finite element thermal analysis algorithm, based on Galerkin's Method of Weighted Residuals (GFE), was formulated specifically for this problem and was used in comparison to the thermal analyzers of the Engineering Analysis Language (EAL). Both analyses allow conduction, convection, and radiation boundary conditions. Differences in the respective finite element formulation are discussed in terms of their accuracy and resulting comparison discrepancies. The thermal analyses are shown to perform well for the comparisons presented here with some important precautions about the various boundary condition models. A description of the experiment, corresponding analytical modeling, and resulting comparisons are presented.

  1. Precise realization of the thermal radiation environment for an optical lattice clock

    NASA Astrophysics Data System (ADS)

    Beloy, Kyle; Sherman, Jeff; Phillips, Nathaniel; Hinkley, Nathan; Oates, Chris; Ludlow, Andrew

    2013-05-01

    The Stark shift due to thermal radiation contributes one of the largest known perturbations to the clock transition frequency of optical lattice clocks. Consequently, the uncertainty stemming from this shift has played a dominant role in the total uncertainty of these standards. Following recent works focused on atomic response factors (e.g., the differential polarizability), uncertainty in this perturbation is now limited by imprecise knowledge of the environment itself. Here we present progress towards precise realization of the thermal radiation environment in a Yb optical lattice clock by trapping the atoms in a highly uniform radiation shield at a well-known temperature. We characterize the non-ideal aspects of this approach, including less than unit emissivity, contamination of the blackbody environment from the ambient environment, and thermal non-uniformities.

  2. Impact of cabin environment on thermal protection system of crew hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Zhu, Xiao Wei; Zhao, Jing Quan; Zhu, Lei; Yu, Xi Kui

    2016-05-01

    Hypersonic crew vehicles need reliable thermal protection systems (TPS) to ensure their safety. Since there exists relative large temperature difference between cabin airflow and TPS structure, the TPS shield that covers the cabin is always subjected to a non-adiabatic inner boundary condition, which may influence the heat transfer characteristic of the TPS. However, previous literatures always neglected the influence of the inner boundary by assuming that it was perfectly adiabatic. The present work focuses on studying the impact of cabin environment on the thermal performance. A modified TPS model is created with a mixed thermal boundary condition to connect the cabin environment with the TPS. This helps make the simulation closer to the real situation. The results stress that cabin environment greatly influences the temperature profile inside the TPS, which should not be neglected in practice. Moreover, the TPS size can be optimized during the design procedure if taking the effect of cabin environment into account.

  3. Natural environment and thermal behaviour of Dimetrodon limbatus.

    PubMed

    Florides; Kalogirou; Tassou; Wrobel

    2001-02-01

    This paper examines the body temperature variation of Dimetrodon during the different seasons of the year. The effect of the sail of Dimetrodon on its body temperature is also evaluated. It is shown that the sail of pelycosaurs provided an advantage to the reptile by warming it up quicker in the morning in cold environments. This would be a benefit, allowing Dimetrodon to prey on large reptiles, above 55kg, in the early morning while they were sluggish. From the results presented a climate similar to that of March for Cyprus could be representative of that of Permian period. PMID:11070340

  4. Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

    NASA Technical Reports Server (NTRS)

    Bradley, David E.; Mireles, Omar R.; Hickman, Robert R.

    2011-01-01

    Deep space missions with large payloads require high specific impulse (Isp) and relatively high thrust in order to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average Isp. Nuclear thermal rockets (NTR) capable of high Isp thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high temperature hydrogen exposure on fuel elements is limited. The primary concern is the mechanical failure of fuel elements which employ high-melting-point metals, ceramics or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via non-contact RF heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

  5. Self-correcting quantum memory in a thermal environment

    NASA Astrophysics Data System (ADS)

    Chesi, Stefano; Röthlisberger, Beat; Loss, Daniel

    2010-08-01

    The ability to store information is of fundamental importance to any computer, be it classical or quantum. To identify systems for quantum memories, which rely, analogously to classical memories, on passive error protection (“self-correction”), is of greatest interest in quantum information science. While systems with topological ground states have been considered to be promising candidates, a large class of them was recently proven unstable against thermal fluctuations. Here, we propose two-dimensional (2D) spin models unaffected by this result. Specifically, we introduce repulsive long-range interactions in the toric code and establish a memory lifetime polynomially increasing with the system size. This remarkable stability is shown to originate directly from the repulsive long-range nature of the interactions. We study the time dynamics of the quantum memory in terms of diffusing anyons and support our analytical results with extensive numerical simulations. Our findings demonstrate that self-correcting quantum memories can exist in 2D at finite temperatures.

  6. Heated-Atmosphere Airship for the Titan Environment: Thermal Analysis

    NASA Technical Reports Server (NTRS)

    Heller, R. S.; Landis, G. A.; Hepp, A. F.; Colozza, A. J.

    2012-01-01

    Future exploration of Saturn's moon Titan can be carried out by airships. Several lighter-than-atmosphere gas airships and passive drifting heated-atmosphere balloon designs have been studied, but a heated-atmosphere airship could combine the best characteristics of both. This work analyses the thermal design of such a heated-atmosphere vehicle, and compares the result with a lighter-than-atmosphere (hydrogen) airship design. A design tool was created to enable iteration through different design parameters of a heated-atmosphere airship (diameter, number of layers, and insulating gas pocket thicknesses) and evaluate the feasibility of the resulting airship. A baseline heated-atmosphere airship was designed to have a diameter of 6 m (outer diameter of 6.2 m), three-layers of material, and an insulating gas pocket thickness of 0.05 m between each layer. The heated-atmosphere airship has a mass of 161.9 kg. A similar mission making use of a hydrogen-filled airship would require a diameter of 4.3 m and a mass of about 200 kg. For a long-duration mission, the heated-atmosphere airship appears better suited. However, for a mission lifetime under 180 days, the less complex hydrogen airship would likely be a better option.

  7. Performance of thermal barrier coatings in high heat flux environments

    NASA Technical Reports Server (NTRS)

    Miller, R. A.; Berndt, C. C.

    1984-01-01

    Thermal barrier coatings were exposed to the high temperature and high heat flux produced by a 30 kW plasma torch. Analysis of the specimen heating rates indicates that the temperature drop across the thickness of the 0.038 cm ceramic layer was about 1100 C after 0.5 sec in the flame. An as-sprayed ZrO2-8 percent Y203 specimens survived 3000 of the 0.5 sec cycles with failing. Surface spalling was observed when 2.5 sec cycles were employed but this was attributed to uneven heating caused by surface roughness. This surface spalling was prevented by smoothing the surface with silicon carbide paper or by laser glazing. A coated specimen with no surface modification but which was heat treated in argon also did not surface spall. Heat treatment in air led to spalling in as early as 2 cycle from heating stresses. Failures at edges were investigated and shown to be a minor source of concern. Ceramic coatings formed from ZrO2-12 percent Y2O3 or ZrO2-20 percent Y2O3 were shown to be unsuited for use under the high heat flux conditions of this study.

  8. Performance of thermal barrier coatings in high heat flux environments

    NASA Technical Reports Server (NTRS)

    Miller, R. A.; Berndt, C. C.

    1984-01-01

    Thermal barrier coatings were exposed to the high temperature and high heat flux produced by a 30 kW plasma torch. Analysis of the specimen heating rates indicates that the temperature drop across the thickness of the 0.038 cm ceramic layer was about 1100 C after 0.5 sec in the flame. An as-sprayed ZrO2-8 percent Y2O3 specimens survived 3000 of the 0.5 sec cycles with falling. Surface spalling was observed when 2.5 sec cycles were employed but this was attributed to uneven heating caused by surface roughness. This surface spalling was prevented by smoothing the surface with silicon carbide paper or by laser glazing. A coated specimen with no surface modification but which was heat treated in argon also did not surface spall. Heat treatment in air led to spalling in as early as 1 cycle from heating stresses. Failures at edges were investigated and shown to be a minor source of concern. Ceramic coatings formed from ZrO2-12 percent Y2O3 or ZrO2-2O percent Y2O3 were shown to be unsuited for use under the high heat flux conditions of this study.

  9. Performance of thermal barrier coatings in high heat flux environments

    NASA Technical Reports Server (NTRS)

    Miller, R. A.; Berndt, C. C.

    1984-01-01

    Thermal barrier coatings were exposed to the high temperature and high heat flux produced by a 30 kW plasma torch. Analysis of the specimen heating rates indicates that the temperature drop across the thickness of the 0.038 cm ceramic layer was about 1100 C after 0.5 sec in the flame. An as-sprayed ZrO2-8%Y2O3 specimens survived 3000 of the 0.5 sec cycles with failing. Surface spalling was observed when 2.5 sec cycles were employed but this was attributed to uneven heating caused by surface roughness. This surface spalling was prevented by smoothing the surface with silicon carbide paper or by laser glazing. A coated specimen with no surface modification but which was heat treated in argon also did not surface spall. Heat treatment in air led to spalling in as early as 2 cycle from heating stresses. Failures at edges were investigated and shown to be a minor source of concern. Ceramic coatings formed from ZrO2-12%Y2O3 or ZrO2-20%Y2O3 were shown to be unsuited for use under the high heat flux conditions of this study.

  10. Coupled thermal/chemical/mechanical modeling of insensitive explosives in thermal environments

    SciTech Connect

    Nichols, A.L. III

    1996-05-01

    The ability to predict the response of a weapon system that contains insensitive explosives to elevated temperatures is important in understanding its safety characteristics. To model such a system at elevated temperatures in a finite element computer code requires a variety of capabilities. These modeling capabilities include thermal diffusion and convection to transport the heat to the explosives in the weapon system, temperature based chemical reaction modeling of the decomposition of the explosive materials, and mechanical modeling of both the metal casing and the unreacted and decomposed explosive. The Chemical TOPAZ code has been developed to model coupled thermal/chemical problems where we do not need to model the mass motion. We have also developed the LYNX2D code, based on PALM2D and Chemical TOPAZ, which is an implicit, two-dimensional coupled thermal/chemical/mechanical finite element model computer code. Some representative examples are shown. {copyright} {ital 1996 American Institute of Physics.}

  11. Parallel trait adaptation across opposing thermal environments in experimental Drosophila melanogaster populations

    PubMed Central

    Tobler, Ray; Hermisson, Joachim; Schlötterer, Christian

    2015-01-01

    Thermal stress is a pervasive selective agent in natural populations that impacts organismal growth, survival, and reproduction. Drosophila melanogaster exhibits a variety of putatively adaptive phenotypic responses to thermal stress in natural and experimental settings; however, accompanying assessments of fitness are typically lacking. Here, we quantify changes in fitness and known thermal tolerance traits in replicated experimental D. melanogaster populations following more than 40 generations of evolution to either cyclic cold or hot temperatures. By evaluating fitness for both evolved populations alongside a reconstituted starting population, we show that the evolved populations were the best adapted within their respective thermal environments. More strikingly, the evolved populations exhibited increased fitness in both environments and improved resistance to both acute heat and cold stress. This unexpected parallel response appeared to be an adaptation to the rapid temperature changes that drove the cycling thermal regimes, as parallel fitness changes were not observed when tested in a constant thermal environment. Our results add to a small, but growing group of studies that demonstrate the importance of fluctuating temperature changes for thermal adaptation and highlight the need for additional work in this area. PMID:26080903

  12. Galileo probe forebody thermal protection - Benchmark heating environment calculations

    NASA Technical Reports Server (NTRS)

    Balakrishnan, A.; Nicolet, W. E.

    1981-01-01

    Solutions are presented for the aerothermal heating environment for the forebody heatshield of candidate Galileo probe. Entry into both the nominal and cool-heavy model atmospheres were considered. Solutions were obtained for the candidate heavy probe with a weight of 310 kg and a lighter probe with a weight of 290 kg. In the flowfield analysis, a finite difference procedure was employed to obtain benchmark predictions of pressure, radiative and convective heating rates, and the steady-state wall blowing rates. Calculated heating rates for entry into the cool-heavy model atmosphere were about 60 percent higher than those predicted for the entry into the nominal atmosphere. The total mass lost for entry into the cool-heavy model atmosphere was about 146 kg and the mass lost for entry into the nominal model atmosphere was about 101 kg.

  13. Re-Configurable Electronics Characterization under Extreme Thermal Environment

    NASA Technical Reports Server (NTRS)

    Stoica, Adrian; Lacayo, Veronica; Ramesham, Rajeshuni; Keymeulen, Didier; Zebulum, Ricardo; Neff, Joe; Burke, Gary; Daud, Taher

    2005-01-01

    The need for reconfigurable electronics is driven by requirements to survive longer missions and harsher environments. It is possible to compensate for degradations in Extreme Environments (EE). EE has effect on electronics: circuits are designed to exploit device characteristics and when a certain temperature or radiation range is exceeded the circuit function gradually degrades. It is possible to employ Hardening by reconfiguration (HBR) to mitigate drifts, degradation, or damage on electronic devices in EE by using reconfigurable devices and an adaptive self-reconfiguration of circuit topology. In this manner degraded components can be salvaged, and completely damaged components can be bypassed. The challenge of conventional design is replaced with that of designing a recover process that automatically performs the (re) design in place of the designer. The objective of testing a Digital Signal Processor (DSP) under the extreme temperatures was to determine the lowest temperature at which the DAP can operate. The objective of testing a Xilinx VirtexII Pro FPGA board was to initially find our whether the evaluation board and the FPGA would survive and continue at temperature ranges from -180 C, and 120 C. The Virtex II functioned correctly at the temperatures tested. The next test was done on the GM-C filter building block using the same temperature range as the Virtex II. The current lower and upper limits were shown to be reduced as the temperature gets lower. The device function can be recovered by increasing the Vb from .08V to .85V. The negative and positive saturation voltages increases as the temperature gets higher. The function of the device can be recovered by decreasing the Vb from .8V to around .75V. The next test was performed to test the recovery of the GmC low pass filter through Vb in a filter circuit. The test indicate that bias voltage control adjustment is an efficient mechanism for circuit recovery at extreme temperatures.

  14. Shuttle payload bay thermal environments: Summary and conclusion report for STS Flights 1-5

    NASA Technical Reports Server (NTRS)

    Fu, J. H.; Graves, G. R.

    1987-01-01

    The thermal data for the payload bay of the first five shuttle flights is summarized and the engineering evaluation of that data is presented. After a general discussion on mission profiles and vehicle configurations, the thermal design and flight instrumentation systems of the payload bay are described. The thermal flight data sources and a categorization of the data are then presented. A thermal flight data summarization section provides temperature data for the five phases of a typical mission profile. These are: prelaunch, ascent, on-orbit, entry and postlanding. The thermal flight data characterization section encompasses this flight data for flight to flight variations, payload effects, temperature ranges, and other variations. Discussion of the thermal environment prediction models in use by industry and various NASA Centers, and the results predicted by these models, is followed by an evaluation of the correlation between the actual flight data and the results predicted by the models. Finally, the available thermal data are evaluated from the viewpoint of the user concerned with establishing the thermal environment in the payload bay. The data deficiencies are discussed and recommendations for their elimination are presented.

  15. Thermal sharpening in agricultural environments and the utility of high resolution HyspIRI thermal data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many agricultural fields in Europe and developing countries are relatively small on the order of 1- 10 hectares, and even though in the U.S. agricultural fields tend to be larger, the resolution of thermal-infrared temperature (TIR) sensors from operational satellites are still generally too coarse...

  16. Predicted optical performance of the high-altitude balloon experiment (HABE) telescope in an adverse thermal environment

    SciTech Connect

    Akau, R.L.; Givler, R.C.; Eastman, D.R.

    1994-04-01

    The High-Altitude Balloon Experiment (HABE) telescope was designed to operate at an ambient temperature of {minus}55 C and an altitude of 26 km, using a precooled primary mirror. Although at this altitude the air density is only 1.4 percent of the value at sea level, the temperature gradients within the telescope are high enough to deform the optical wavefront. This problem is considerably lessened by precooling the primary mirror to {minus}35 C. This paper describes the application of several codes to determine the range of wavefront deformation during a mission.

  17. Dynamic and acoustic response of a clamped rectangular plate in thermal environments: experiment and numerical simulation.

    PubMed

    Geng, Qian; Li, Huan; Li, Yueming

    2014-05-01

    Experiments were performed to investigate the vibration and acoustic response characteristics of a clamped rectangular aluminum plate in thermal environments. Modal tests were carried out to study the influence of thermal environment on natural vibration. With the increment of structural temperature, natural frequencies of the plate decrease obviously. Mode shape interchange was observed for the modes with frequencies very close to each other. The thermally induced softening effect has unequal influences on the plate along the two in-plane directions. Numerical methods were also employed to study the experimental phenomena. Calculated results indicated that the initial deflection has a great influence on the natural vibration of the heated plate. Even a slight curvature can reduce the thermally induced softening effect obviously. Dynamic response tests were carried out under acoustic and mechanical excitations, and the measured results indicate that the variation in damping determines the response amplitudes at resonant peaks in the test. PMID:24815251

  18. Health Risk Assessment of Inhalable Particulate Matter in Beijing Based on the Thermal Environment

    PubMed Central

    Xu, Lin-Yu; Yin, Hao; Xie, Xiao-Dong

    2014-01-01

    Inhalable particulate matter (PM10) is a primary air pollutant closely related to public health, and an especially serious problem in urban areas. The urban heat island (UHI) effect has made the urban PM10 pollution situation more complex and severe. In this study, we established a health risk assessment system utilizing an epidemiological method taking the thermal environment effects into consideration. We utilized a remote sensing method to retrieve the PM10 concentration, UHI, Normalized Difference Vegetation Index (NDVI), and Normalized Difference Water Index (NDWI). With the correlation between difference vegetation index (DVI) and PM10 concentration, we utilized the established model between PM10 and thermal environmental indicators to evaluate the PM10 health risks based on the epidemiological study. Additionally, with the regulation of UHI, NDVI and NDWI, we aimed at regulating the PM10 health risks and thermal environment simultaneously. This study attempted to accomplish concurrent thermal environment regulation and elimination of PM10 health risks through control of UHI intensity. The results indicate that urban Beijing has a higher PM10 health risk than rural areas; PM10 health risk based on the thermal environment is 1.145, which is similar to the health risk calculated (1.144) from the PM10 concentration inversion; according to the regulation results, regulation of UHI and NDVI is effective and helpful for mitigation of PM10 health risk in functional zones. PMID:25464132

  19. Health risk assessment of inhalable particulate matter in Beijing based on the thermal environment.

    PubMed

    Xu, Lin-Yu; Yin, Hao; Xie, Xiao-Dong

    2014-12-01

    Inhalable particulate matter (PM10) is a primary air pollutant closely related to public health, and an especially serious problem in urban areas. The urban heat island (UHI) effect has made the urban PM10 pollution situation more complex and severe. In this study, we established a health risk assessment system utilizing an epidemiological method taking the thermal environment effects into consideration. We utilized a remote sensing method to retrieve the PM10 concentration, UHI, Normalized Difference Vegetation Index (NDVI), and Normalized Difference Water Index (NDWI). With the correlation between difference vegetation index (DVI) and PM10 concentration, we utilized the established model between PM10 and thermal environmental indicators to evaluate the PM10 health risks based on the epidemiological study. Additionally, with the regulation of UHI, NDVI and NDWI, we aimed at regulating the PM10 health risks and thermal environment simultaneously. This study attempted to accomplish concurrent thermal environment regulation and elimination of PM10 health risks through control of UHI intensity. The results indicate that urban Beijing has a higher PM10 health risk than rural areas; PM10 health risk based on the thermal environment is 1.145, which is similar to the health risk calculated (1.144) from the PM10 concentration inversion; according to the regulation results, regulation of UHI and NDVI is effective and helpful for mitigation of PM10 health risk in functional zones. PMID:25464132

  20. Thermal analysis of thermal barrier coatings in a high heat flux environment

    NASA Technical Reports Server (NTRS)

    Nesbitt, James A.; Brindley, William J.

    1988-01-01

    Gas temperatures and pressures were measured around the second test position in the H2/O2 rocket engine at NASA-Lewis. Measured gas temperatures generally varied from 1210 to 1390 C. Measured pressures were in good agreement with other studies for throat tubes in a square chamber rocket engine. Heat transfer coefficients were measured at 90 and 180 degrees from the stagnation point and resulted in values of 27.5 and 8.5 kW/sq m C, respectively. A thermal model was developed to predict temperatures in bare and coated tubes and rods. Agreement between measured and predicted temperatures below the surface of a bare Mar-M 246 tube was very good for most of the heat up and cool down period. Predicted temperatures were significantly below measured temperatures for the coated tubes. A thermal model to simulate heat transfer to the leading edge of an HPFTP blade was developed and showed that TBCs can significantly dampen the thermal transient which occurs in the HPFTP during the startup of the SSME.

  1. A heterogeneous thermal environment enables remarkable behavioral thermoregulation in Uta stansburiana

    PubMed Central

    Goller, Maria; Goller, Franz; French, Susannah S

    2014-01-01

    Ectotherms can attain preferred body temperatures by selecting specific temperature microhabitats within a varied thermal environment. The side-blotched lizard, Uta stansburiana may employ microhabitat selection to thermoregulate behaviorally. It is unknown to what degree habitat structural complexity provides thermal microhabitats for thermoregulation. Thermal microhabitat structure, lizard temperature, and substrate preference were simultaneously evaluated using thermal imaging. A broad range of microhabitat temperatures was available (mean range of 11°C within 1–2 m2) while mean lizard temperature was between 36°C and 38°C. Lizards selected sites that differed significantly from the mean environmental temperature, indicating behavioral thermoregulation, and maintained a temperature significantly above that of their perch (mean difference of 2.6°C). Uta's thermoregulatory potential within a complex thermal microhabitat structure suggests that a warming trend may prove advantageous, rather than detrimental for this population. PMID:25535549

  2. Diffusion in a soft confining environment: Dynamic effects of thermal fluctuations

    NASA Astrophysics Data System (ADS)

    Palmieri, Benoit; Safran, Samuel

    2013-03-01

    A dynamical model of a soft, thermally fluctuating two-dimensional tube is used to study the effect of thermal fluctuations of a confining environment on diffusive transport. The tube fluctuations in both space and time are driven by Brownian motion and suppressed by surface tension and the rigidity of the surrounding environment. The dynamical fluctuations modify the concentration profile boundary condition at the tube surface. They decrease the diffusive transport rate through the tube for two important cases: uniform tube fluctuations (wave vector, q = 0 mode) for finite tube lengths and fluctuations of any wave vector for infinitely long tubes.

  3. Diffusion in a soft confining environment: Dynamic effects of thermal fluctuations

    NASA Astrophysics Data System (ADS)

    Palmieri, Benoit; Safran, Samuel A.

    2012-09-01

    A dynamical model of a soft, thermally fluctuating two-dimensional tube is used to study the effect of thermal fluctuations of a confining environment on diffusive transport. The tube fluctuations in both space and time are driven by Brownian motion and suppressed by surface tension and the rigidity of the surrounding environment. The dynamical fluctuations modify the concentration profile boundary condition at the tube surface. They decrease the diffusive transport rate through the tube for two important cases: uniform tube fluctuations (wave vector, q=0 mode) for finite tube lengths and fluctuations of any wave vector for infinitely long tubes.

  4. Recent extreme slope failures in glacial environments: effects of thermal perturbation

    NASA Astrophysics Data System (ADS)

    Huggel, Christian

    2009-06-01

    This paper describes recent exceptional slope failures in high-mountain, glacial environments: the 2002 Kolka-Karmadon rock-ice avalanche in the Caucasus, a series of ice-rock avalanches on Iliamna Volcano, Alaska, the 2005 Mt. Steller rock-ice avalanche in Alaska, and ice and rock avalanches at Monte Rosa, Italy in 2005 and 2007. Deposit volumes range from 10 6 to 10 8 m 3 and include rock, ice and snow. Here we focus on thermal aspects of these failures reflecting the involvement of glacier ice and permafrost at all sites, suggesting that thermal perturbations likely contributed to the slope failures. We use surface and troposphere air temperatures, near-surface rock temperatures, satellite thermal data, and recent 2D and 3D thermal modeling studies to document thermal conditions at the landslide sites. We distinguish between thermal perturbations of volcanic-geothermal and climatic origin, and thermal perturbations related to glacier-permafrost interaction. The data and analysis support the view that recent, current and future climatic change increases the likelihood of large slope failures in steep glacierized and permafrost terrain. However, some important aspects of these settings such as the geology and tectonic environment remain poorly understood, making the identification of future sites of large slope instabilities difficult. In view of the potentially large natural disasters that can be caused by such slope failures, improved data and understanding are needed.

  5. Contrasting impacts of urban forms on the future thermal environment: example of Beijing metropolitan area

    NASA Astrophysics Data System (ADS)

    Yang, Long; Niyogi, Dev; Tewari, Mukul; Aliaga, Daniel; Chen, Fei; Tian, Fuqiang; Ni, Guangheng

    2016-03-01

    This study investigated impacts of urban forms on the future thermal environment over Beijing, the capital city of China. Beijing is experiencing remarkable urban expansion and is planned to undergo the transformation of urban forms from single-centric (compact-city) to poly-centric city (dispersed-city). Impacts of urban forms on the future thermal environment were compared and evaluated by conducting numerical experiments based on a regional atmospheric model coupled with a single-layer urban canopy model as well as future climate forcing output from a global climate model. Results show that a dispersed city is efficient in reducing mean urban heat island intensity, but produces larger thermal loading and deeper thermal feedback at the regional scale compared to a compact city. Thermal comfort over downtown areas is reduced in compact-city scenario under future climate conditions. Future climate contributes almost 80% of the additional thermal loading over urban areas, with the remaining 20% contributed by urbanization (for both the compact-city and dispersed-city scenarios). The thermal contrast between the two urban forms is dominated by the expected future climate change. This study leads to two complementary conclusions: (i) for developing assessments related to current climate comfort, urban form of the city is important; (ii) for assessing future climate change impacts, the areal coverage of the city and urbanization extent emerges to be more important than the details related to how the urbanization will evolve.

  6. A standard predictive index of human response to the thermal environment

    SciTech Connect

    Gagge, A.P.; Fobelets, A.P.; Berglund, L.G.

    1986-01-01

    Temperature and sensory indicates of human response to the thermal environment are often expressed in terms of the known response in a controlled laboratory environment, as a standard. The three rational indices of this type to be considered are ASHRAE's Standard Effective Temperature (SET*) Index, defined as the equivalent dry bulb temperature of an isothermal environment at 50% RH in which a subject, while wearing clothing standardized for activity concerned, would have the same heat stress (skin temperature T/sub sk/) and thermo-regulatory strain (skin wettedness, w) as in the actual test environment; Fanger's Predicted Mean Vote (PMV) Index, defined in terms of the heat load that would be required to restore a state of ''Comfort'' and evaluated by his Comfort Equation; and Winslow's Skin Wettedness Index of ''Thermal Discomfort'' (DISC) defined in terms of the fraction of the body surface, wet with perspiration, required to regulate body temperature by evaporative cooling.

  7. Degradation of thermal control materials under a simulated radiative space environment

    NASA Astrophysics Data System (ADS)

    Sharma, A. K.; Sridhara, N.

    2012-11-01

    A spacecraft with a passive thermal control system utilizes various thermal control materials to maintain temperatures within safe operating limits. Materials used for spacecraft applications are exposed to harsh space environments such as ultraviolet (UV) and particle (electron, proton) irradiation and atomic oxygen (AO), undergo physical damage and thermal degradation, which must be considered for spacecraft thermal design optimization and cost effectiveness. This paper describes the effect of synergistic radiation on some of the important thermal control materials to verify the assumptions of beginning-of-life (BOL) and end-of-life (EOL) properties. Studies on the degradation in the optical properties (solar absorptance and infrared emittance) of some important thermal control materials exposed to simulated radiative geostationary space environment are discussed. The current studies are purely related to the influence of radiation on the degradation of the materials; other environmental aspects (e.g., thermal cycling) are not discussed. The thermal control materials investigated herein include different kind of second-surface mirrors, white anodizing, white paints, black paints, multilayer insulation materials, varnish coated aluminized polyimide, germanium coated polyimide, polyether ether ketone (PEEK) and poly tetra fluoro ethylene (PTFE). For this purpose, a test in the constant vacuum was performed reproducing a three year radiative space environment exposure, including ultraviolet and charged particle effects on North/South panels of a geostationary three-axis stabilized spacecraft. Reflectance spectra were measured in situ in the solar range (250-2500 nm) and the corresponding solar absorptance values were calculated. The test methodology and the degradations of the materials are discussed. The most important degradations among the low solar absorptance materials were found in the white paints whereas the rigid optical solar reflectors remained quite

  8. Thermal stability and energy harvesting characteristics of Au nanorods: harsh environment chemical sensing

    NASA Astrophysics Data System (ADS)

    Karker, Nicholas; Dharmalingam, Gnanaprakash; Carpenter, Michael A.

    2015-05-01

    Monitoring the levels of polluting gases such as CO and NOx from high temperature (500°C and higher) combustion environments requires materials with high thermal stability and resilience that can withstand harsh oxidizing and reducing environments. Au nanorods (AuNRs) have shown potential in plasmonic gas sensing due to their catalytic activity, high oxidation stability, and absorbance sensitivity to changes in the surrounding environment. By using electron beam lithography, AuNR geometries can be patterned with tight control of the rod dimensions and spacings, allowing tunability of their optical properties. Methods such as NR encapsulation within an yttria-stabilized zirconia overcoat layer with subsequent annealing procedures will be shown to improve temperature stability within a simulated harsh environment. Since light sources and spectrometers are typically required to obtain optical measurements, integration is a major barrier for harsh environment sensing. Plasmonic sensing results will be presented where thermal energy is harvested by the AuNRs, which replaces the need for an external incident light source. Results from gas sensing experiments that utilize thermal energy harvesting are in good agreement with experiments which use an external incident light source. Principal component analysis results demonstrate that by selecting the most "active" wavelengths in a plasmonic band, the wavelength space can be reduced from hundreds of monitored wavelengths to just four, without loss of information about selectivity of the AuNRs. By combining thermal stability, the thermal energy harvesting capability, and the selectivity in gas detection (achieved through multivariate analysis), integration of plasmonic sensors into combustion environments can be greatly simplified.

  9. Computational Prediction of Pressure and Thermal Environments in the Flame Trench With Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Brehm, Christoph; Sozer, Emre; Barad, Michael F.; Housman, Jeffrey A.; Kiris, Cetin C.; Moini-Yekta, Shayan; Vu, Bruce T.; Parlier, Christopher R.

    2014-01-01

    One of the key objectives for the development of the 21st Century Space Launch Com- plex is to provide the exibility needed to support evolving launch vehicles and spacecrafts with enhanced range capacity. The launch complex needs to support various proprietary and commercial vehicles with widely di erent needs. The design of a multi-purpose main ame de ector supporting many di erent launch vehicles becomes a very challenging task when considering that even small geometric changes may have a strong impact on the pressure and thermal environment. The physical and geometric complexity encountered at the launch site require the use of state-of-the-art Computational Fluid Dynamics (CFD) tools to predict the pressure and thermal environments. Due to harsh conditions encountered in the launch environment, currently available CFD methods which are frequently employed for aerodynamic and ther- mal load predictions in aerospace applications, reach their limits of validity. This paper provides an in-depth discussion on the computational and physical challenges encountered when attempting to provide a detailed description of the ow eld in the launch environ- ment. Several modeling aspects, such as viscous versus inviscid calculations, single-species versus multiple-species ow models, and calorically perfect gas versus thermally perfect gas, are discussed. The Space Shuttle and the Falcon Heavy launch vehicles are used to study di erent engine and geometric con gurations. Finally, we provide a discussion on traditional analytical tools which have been used to provide estimates on the expected pressure and thermal loads.

  10. Computer program determines thermal environment and temperature history of lunar orbiting space vehicles

    NASA Technical Reports Server (NTRS)

    Head, D. E.; Mitchell, K. L.

    1967-01-01

    Program computes the thermal environment of a spacecraft in a lunar orbit. The quantities determined include the incident flux /solar and lunar emitted radiation/, total radiation absorbed by a surface, and the resulting surface temperature as a function of time and orbital position.

  11. Radiation-Driven Flame Spread Over Thermally-Thick Fuels in Quiescent Microgravity Environments

    NASA Technical Reports Server (NTRS)

    Honda, Linton K.; Son, Youngjin; Ronney, Paul D.; Olson, Sandra (Technical Monitor); Gokoglu, Suleyman (Technical Monitor)

    2001-01-01

    Microgravity experiments on flame spread over thermally thick fuels were conducted using foam fuels to obtain low density and thermal conductivity, and thus large spread rate (Sf) compared to dense fuels such as PMMA. This scheme enabled meaningful results to lie obtained even in 2.2 second drop tower experiments. It was found that, in contrast conventional understanding; steady spread can occur over thick fuels in quiescent microgravity environments, especially when a radiatively active diluent gas such as CO2 is employed. This is proposed to be due to radiative transfer from the flame to the fuel surface. Additionally, the transition from thermally thick to thermally thin behavior with decreasing bed thickness is demonstrated.

  12. Entanglement of formation in two-mode Gaussian systems in a thermal environment

    SciTech Connect

    Dumitru, Irina Isar, Aurelian

    2015-12-07

    In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous variable entanglement for a system consisting of two non-interacting bosonic modes embedded in a thermal environment. The calculated measure of entanglement is entanglement of formation. We describe the evolution of entanglement in terms of the covariance matrix for symmetric Gaussian input states. In the case of an entangled initial squeezed thermal state, entanglement suppression (entanglement sudden death) takes place, for all non-zero temperatures of the thermal bath. After that, the system remains for all times in a separable state. For a zero temperature of the thermal bath, the system remains entangled for all finite times, but in the limit of asymptotic large times the state becomes separable.

  13. Entanglement of formation in two-mode Gaussian systems in a thermal environment

    NASA Astrophysics Data System (ADS)

    Dumitru, Irina; Isar, Aurelian

    2015-12-01

    In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous variable entanglement for a system consisting of two non-interacting bosonic modes embedded in a thermal environment. The calculated measure of entanglement is entanglement of formation. We describe the evolution of entanglement in terms of the covariance matrix for symmetric Gaussian input states. In the case of an entangled initial squeezed thermal state, entanglement suppression (entanglement sudden death) takes place, for all non-zero temperatures of the thermal bath. After that, the system remains for all times in a separable state. For a zero temperature of the thermal bath, the system remains entangled for all finite times, but in the limit of asymptotic large times the state becomes separable.

  14. Durability of thermal control and environmental protective materials for the SSRMS in simulated LEO environment

    NASA Astrophysics Data System (ADS)

    Chang, S. K.

    1993-06-01

    Nine thermal control and environmental protection materials, selected on the basis of their space pedigree, thermal vacuum stability, and thermo-optical properties, were tested to determine their suitability for the Space Station Remote Manipulator System (SSRMS). The ground based testing was carried out to simulate the effects of atomic oxygen and thermal cycling in the Low Earth Orbit (LEO) environment. These factors are deemed most likely to cause degradation to the selected materials. With the exception of the urethane based coatings, the materials tested demonstrate sufficient resistance to atomic oxygen. The detrimental effect of thermal cycling on the adhesion of the silicate based coatings to aluminum substrate was found to depend on the pigment. A separate experiment on Beta-Cloth showed that its thermo-optical properties remained substantially unchanged as the Teflon coating was progressively removed in a plasma asher.

  15. Man-Made Closed Ecological Systems as Model of Natural Ecosystems and as Means to Provide High Quality of Human Life in Adverse Environment

    NASA Technical Reports Server (NTRS)

    Gitelson, I. I.; Harper, Lynn (Technical Monitor)

    1994-01-01

    For its more than thirty year long history, the experimental creation of closed ecological systems has from its very sources been distinctly and strongly motivated by the development of human life-support systems for space. As the trend developed its fundamental significance and broad opportunities of terrestrial applications of the technologies under development were coming to the foreground. Nowadays, it can be argued that development of closed ecosystems is experimental foundation of a new branch of ecology biospherics, the goal of which is to comprehend the regularities of existence of the biosphere as a unique in the Universe (in that part of it that we know, at least) closed ecosystem. Closed technologies can be implemented in life-support systems under adverse conditions of life on the Earth - in Arctic and Antarctic latitudes, deserts, high mountains or deep in the ocean, as well as under the conditions of polluted water and air. In space where the environment is hostile for life all around the cell of life should be sealed and the life-support system as close to the ideally closed cyclic turnover of the matter as possible. Under terrestrial conditions designers should strive for maximum closure of the limiting factor: water - in deserts, oxygen - in high mountains, energy - in polar latitudes, etc. Essential closure of a life-support systems withstands also pollution of the environment by the wastes of human vital activity. This is of particular importance for the quarantine of visited planets, and on the Earth under the conditions of deficient heat in high latitudes and water in and areas. The report describes experimental ecosystem 'BIOS' and exohabitats being designed on its basis, which are adapted to various conditions, described capacities of the Center for Closed Ecosystems in Drasnoyarsk for international collaboration in research and education in this field.

  16. Summer-time thermal environment characteristics in central Korea using Landsat TM data

    NASA Astrophysics Data System (ADS)

    Park, Jin-Ki; Park, Jong-Hwa; Na, Sang-il

    2010-10-01

    Urban heat island(UHI) effect is the temperature increase in urban areas compared to that in surrounding rural areas and is caused by a number of factors, such as land use / land cover (LULC)change, increase fuel consumption and lack of vegetation in urban core areas. The replacement of natural surface types from soil and vegetation to impervious materials such as asphalt and concrete structures affects the albedo and runoff characteristics of the urban land surface. The impervious materials have a lower albedo than soil and vegetation and hold more solar energy, which increase land surface temperature (LST) during the summer season. UHI effects on the center region of South Korea were analyzed using remotely sensed data. The objectives of this study are to examine the summer-time thermal environment of the Cheongju city in Korea, review the satellite assessment of the thermal environment of LULC, and compare thermal environment in 1991 to 2006. Chang detection of thermal environment is performed to determine whether a significant change has occurred. The average of LST of study area has increased 2.7°C during 15years because of changed land cover from paddy field and forest to barren, factory, and concrete. This case study indicates that barren, factory, and residential apartment over on the Cheongju and Ochang increased in the late 1990s and that vegetation area are changing predominantly in the direction of decreased forest and paddy fields. Decreasing forest and paddy fields are an important result, as it suggests that directional changes are occurring on the Cheongju and Ochang that are consistent with experimental urban warming. The most influential factors for controlling the summer-time thermal environment are the distribution of surface cover characteristics (e.g. LULC) and urban morphology, such as urban consistence materials, geometry, development stage, and density.

  17. Behavior of thermal spray aluminum coating in wet H{sub 2}S environments

    SciTech Connect

    Joia, C.; Berrera, P.; Kane, R.D.

    1999-11-01

    Sulfide stress cracking (SSC) and hydrogen induced cracking can cause severe damage in steel equipment exposed to wet H{sub 2}S environments. Metallic thermal spray coatings based on aluminum protect carbon steel from the corrosive media, when wet H{sub 2}S environments are a concern. In this program, a series of electrochemical tests were conducted. These tests involved exposure of coated samples to various environments containing H{sub 2}S, ammonia, chloride and cyanide to study the behavior of the aluminum coating associated with a stainless steel interlayer both applied by thermal spray. Results showed that the aluminum layer was corroded rapidly in solutions with pH higher than 11. In alkaline solutions with pH lower than 9 a protective aluminum layer and the corrosion rate was very low.

  18. Analysis of Sensory/Active Piezoelectric Composite Structures in Thermal Environments

    NASA Technical Reports Server (NTRS)

    Lee, Ho-Jun; Saravanos, Dimitris A.

    1996-01-01

    Although there has been extensive development of analytical methods for modeling the behavior of piezoelectric structures, only a limited amount of research has been performed concerning the implications of thermal effects on both the active and sensory response of smart structures. Thermal effects become important when the piezoelectric structure has to operate in either extremely hot or cold temperature environments. Consequently, the purpose of this paper is to extend the previously developed discrete layer formulation of Saravanos and Heyliger to account for the coupled mechanical, electrical, and thermal response in modern smart composite beams. The mechanics accounts for thermal effects which may arise in the elastic and piezoelectric media at the material level through the constitutive equations. The displacements, electric potentials, and temperatures are introduced as state variables, allowing them to be modeled as variable fields through the laminate thickness. This unified representation leads to an inherent capability to model both the active compensation of thermal distortions in smart structures and the resultant sensory voltage when thermal loads are applied. The corresponding finite element formulation is developed and numerical results demonstrate the ability to model both the active and sensory modes of composite beams with heterogeneous plies with attached piezoelectric layers under thermal loadings.

  19. Modeling the thermal and structural response of engineered systems to abnormal environments

    SciTech Connect

    Skocypec, R.D.; Thomas, R.K.; Moya, J.L.

    1993-10-01

    Sandia National Laboratories (SNL) is engaged actively in research to improve the ability to accurately predict the response of engineered systems to thermal and structural abnormal environments. Abnormal environments that will be addressed in this paper include: fire, impact, and puncture by probes and fragments, as well as a combination of all of the above. Historically, SNL has demonstrated the survivability of engineered systems to abnormal environments using a balanced approach between numerical simulation and testing. It is necessary to determine the response of engineered systems in two cases: (1) to satisfy regulatory specifications, and (2) to enable quantification of a probabilistic risk assessment (PRA). In a regulatory case, numerical simulation of system response is generally used to guide the system design such that the system will respond satisfactorily to the specified regulatory abnormal environment. Testing is conducted at the regulatory abnormal environment to ensure compliance.

  20. Evaluation of ULV and thermal fog mosquito control applications in temperate and desert environments.

    PubMed

    Britch, Seth C; Linthicum, Kenneth J; Wynn, Wayne W; Walker, Todd W; Farooq, Muhammad; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Lothrop, Hugh D; Kerce, Jerry D; Becnel, James J; Bernier, Ulrich R; Pridgeon, Julia W

    2010-06-01

    Ultra-low-volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only 7 studies have been identified that directly compare their performance in the field. US military personnel currently operating in hot-arid environments are impacted by perpetual nuisance and disease vector insect problems, despite adulticide operations using modern pesticide-delivery equipment such as ULV. None of the identified comparative studies has looked at the relative feasibility and efficacy of ULV and thermal fog equipment against mosquitoes in hot-arid environments. In this study we examine the impact of ULV and thermal fog applications of malathion against caged sentinel mosquitoes in the field in a warm temperate area of Florida, followed by a similar test in a hot-dry desert area of southern California. Patterns of mortality throughout 150 m x 150 m grids of sentinel mosquitoes indicate greater efficacy from the thermal fog application in both environments under suboptimal ambient weather conditions. We discuss the implications of these findings for future military preventive medicine activities and encourage further investigations into the relative merits of the 2 technologies for force health protection. PMID:20649128

  1. Deep-sea hydrothermal vent animals seek cool fluids in a highly variable thermal environment.

    PubMed

    Bates, Amanda E; Lee, Raymond W; Tunnicliffe, Verena; Lamare, Miles D

    2010-01-01

    The thermal characteristics of an organism's environment affect a multitude of parameters, from biochemical to evolutionary processes. Hydrothermal vents on mid-ocean ridges are created when warm hydrothermal fluids are ejected from the seafloor and mixed with cold bottom seawater; many animals thrive along these steep temperature and chemical gradients. Two-dimensional temperature maps at vent sites have demonstrated order of magnitude thermal changes over centimetre distances and at time intervals from minutes to hours. To investigate whether animals adapt to this extreme level of environmental variability, we examined differences in the thermal behaviour of mobile invertebrates from aquatic habitats that vary in thermal regime. Vent animals were highly responsive to heat and preferred much cooler fluids than their upper thermal limits, whereas invertebrates from other aquatic environments risked exposure to warmer temperatures. Avoidance of temperatures well within their tolerated range may allow vent animals to maintain a safety margin against rapid temperature fluctuations and concomitant toxicity of hydrothermal fluids. PMID:20975681

  2. Urban thermal environment and its biophysical parameters derived from satellite remote sensing imagery

    NASA Astrophysics Data System (ADS)

    Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.; Tautan, Marina N.; Baschir, Laurentiu V.

    2013-10-01

    In frame of global warming, the field of urbanization and urban thermal environment are important issues among scientists all over the world. This paper investigated the influences of urbanization on urban thermal environment as well as the relationships of thermal characteristics to other biophysical variables in Bucharest metropolitan area of Romania based on satellite remote sensing imagery Landsat TM/ETM+, time series MODIS Terra/Aqua data and IKONOS acquired during 1990 - 2012 period. Vegetation abundances and percent impervious surfaces were derived by means of linear spectral mixture model, and a method for effectively enhancing impervious surface has been developed to accurately examine the urban growth. The land surface temperature (Ts), a key parameter for urban thermal characteristics analysis, was also retrieved from thermal infrared band of Landsat TM/ETM+, from MODIS Terra/Aqua datasets. Based on these parameters, the urban growth, urban heat island effect (UHI) and the relationships of Ts to other biophysical parameters have been analyzed. Results indicated that the metropolitan area ratio of impervious surface in Bucharest increased significantly during two decades investigated period, the intensity of urban heat island and heat wave events being most significant. The correlation analyses revealed that, at the pixel-scale, Ts possessed a strong positive correlation with percent impervious surfaces and negative correlation with vegetation abundances at the regional scale, respectively. This analysis provided an integrated research scheme and the findings can be very useful for urban ecosystem modeling.

  3. Keeping your options open: Maintenance of thermal plasticity during adaptation to a stable environment.

    PubMed

    Fragata, Inês; Lopes-Cunha, Miguel; Bárbaro, Margarida; Kellen, Bárbara; Lima, Margarida; Faria, Gonçalo S; Seabra, Sofia G; Santos, Mauro; Simões, Pedro; Matos, Margarida

    2016-01-01

    Phenotypic plasticity may allow species to cope with environmental variation. The study of thermal plasticity and its evolution helps understanding how populations respond to variation in temperature. In the context of climate change, it is essential to realize the impact of historical differences in the ability of populations to exhibit a plastic response to thermal variation and how it evolves during colonization of new environments. We have analyzed the real-time evolution of thermal reaction norms of adult and juvenile traits in Drosophila subobscura populations from three locations of Europe in the laboratory. These populations were kept at a constant temperature of 18ºC, and were periodically assayed at three experimental temperatures (13ºC, 18ºC, and 23ºC). We found initial differentiation between populations in thermal plasticity as well as evolutionary convergence in the shape of reaction norms for some adult traits, but not for any of the juvenile traits. Contrary to theoretical expectations, an overall better performance of high latitude populations across temperatures in early generations was observed. Our study shows that the evolution of thermal plasticity is trait specific, and that a new stable environment did not limit the ability of populations to cope with environmental challenges. PMID:26626438

  4. System-environment correlations for dephasing two-qubit states coupled to thermal baths

    NASA Astrophysics Data System (ADS)

    Costa, A. C. S.; Beims, M. W.; Strunz, W. T.

    2016-05-01

    Based on the exact dynamics of a two-qubit system and environment, we investigate system-environment (SE) quantum and classical correlations. The coupling is chosen to represent a dephasing channel for one of the qubits and the environment is a proper thermal bath. First we discuss the general issue of dilation for qubit phase damping. Based on the usual thermal bath of harmonic oscillators, we derive criteria of separability and entanglement between an initial X state and the environment. Applying these criteria to initial Werner states, we find that entanglement between the system and environment is built up in time for temperatures below a certain critical temperature Tcrit. On the other hand, the total state remains separable during those short times that are relevant for decoherence and loss of entanglement in the two-qubit state. Close to Tcrit the SE correlations oscillate between separable and entangled. Even though these oscillations are also observed in the entanglement between the two qubits, no simple relation between the loss of entanglement in the two-qubit system and the build-up of entanglement between the system and environment is found.

  5. Metabolic heat production and thermal conductance are mass-independent adaptations to thermal environment in birds and mammals

    PubMed Central

    Fristoe, Trevor S.; Burger, Joseph R.; Balk, Meghan A.; Khaliq, Imran; Hof, Christian; Brown, James H.

    2015-01-01

    The extent to which different kinds of organisms have adapted to environmental temperature regimes is central to understanding how they respond to climate change. The Scholander–Irving (S-I) model of heat transfer lays the foundation for explaining how endothermic birds and mammals maintain their high, relatively constant body temperatures in the face of wide variation in environmental temperature. The S-I model shows how body temperature is regulated by balancing the rates of heat production and heat loss. Both rates scale with body size, suggesting that larger animals should be better adapted to cold environments than smaller animals, and vice versa. However, the global distributions of ∼9,000 species of terrestrial birds and mammals show that the entire range of body sizes occurs in nearly all climatic regimes. Using physiological and environmental temperature data for 211 bird and 178 mammal species, we test for mass-independent adaptive changes in two key parameters of the S-I model: basal metabolic rate (BMR) and thermal conductance. We derive an axis of thermal adaptation that is independent of body size, extends the S-I model, and highlights interactions among physiological and morphological traits that allow endotherms to persist in a wide range of temperatures. Our macrophysiological and macroecological analyses support our predictions that shifts in BMR and thermal conductance confer important adaptations to environmental temperature in both birds and mammals. PMID:26668359

  6. Metabolic heat production and thermal conductance are mass-independent adaptations to thermal environment in birds and mammals.

    PubMed

    Fristoe, Trevor S; Burger, Joseph R; Balk, Meghan A; Khaliq, Imran; Hof, Christian; Brown, James H

    2015-12-29

    The extent to which different kinds of organisms have adapted to environmental temperature regimes is central to understanding how they respond to climate change. The Scholander-Irving (S-I) model of heat transfer lays the foundation for explaining how endothermic birds and mammals maintain their high, relatively constant body temperatures in the face of wide variation in environmental temperature. The S-I model shows how body temperature is regulated by balancing the rates of heat production and heat loss. Both rates scale with body size, suggesting that larger animals should be better adapted to cold environments than smaller animals, and vice versa. However, the global distributions of ∼9,000 species of terrestrial birds and mammals show that the entire range of body sizes occurs in nearly all climatic regimes. Using physiological and environmental temperature data for 211 bird and 178 mammal species, we test for mass-independent adaptive changes in two key parameters of the S-I model: basal metabolic rate (BMR) and thermal conductance. We derive an axis of thermal adaptation that is independent of body size, extends the S-I model, and highlights interactions among physiological and morphological traits that allow endotherms to persist in a wide range of temperatures. Our macrophysiological and macroecological analyses support our predictions that shifts in BMR and thermal conductance confer important adaptations to environmental temperature in both birds and mammals. PMID:26668359

  7. Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

    NASA Astrophysics Data System (ADS)

    Page, Arthur T.

    2001-07-01

    This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(TM), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(TM) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(TM) generates the SINDA input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment, conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

  8. Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

    NASA Technical Reports Server (NTRS)

    Page, Arthur T.

    2001-01-01

    This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(TM), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(TM) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(TM) generates the SINDA input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment, conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

  9. Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

    NASA Technical Reports Server (NTRS)

    Page, Arhur T.

    1999-01-01

    This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(Tm), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(Tm) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(Tm) generates the SINDA/Fluint input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

  10. Mission Life Thermal Analysis and Environment Correlation for the Lunar Reconnaissance Orbiter

    NASA Technical Reports Server (NTRS)

    Garrison, Matthew B.; Peabody, Hume

    2012-01-01

    Standard thermal analysis practices include stacking worst-case conditions including environmental heat loads, thermo-optical properties and orbital beta angles. This results in the design being driven by a few bounding thermal cases, although those cases may only represent a very small portion of the actual mission life. The NASA Goddard Space Flight Center Thermal Branch developed a procedure to predict the flight temperatures over the entire mission life, assuming a known beta angle progression, variation in the thermal environment, and a degradation rate in the coatings. This was applied to the Global Precipitation Measurement core spacecraft. In order to assess the validity of this process, this work applies the similar process to the Lunar Reconnaissance Orbiter. A flight-correlated thermal model was exercised to give predictions of the thermal performance over the mission life. These results were then compared against flight data from the first two years of the spacecraft s use. This is used to validate the process and to suggest possible improvements for future analyses.

  11. Possible ways of reducing the effect of thermal power facilities on the environment

    NASA Astrophysics Data System (ADS)

    Zroichikov, N. A.; Prokhorov, V. B.; Tupov, V. B.; Arkhipov, A. M.; Fomenko, M. V.

    2015-02-01

    The main trends in the integrated solution of thermal power engineering environmental problems are pointed out taking the Mosenergo power company as an example, and the data are given with respect to the structure of the power engineering equipment of the city of Moscow and its change, energy consumption, and generation of heat and electric energy. The dynamics of atmospheric air pollution of Moscow from 1990 to 2010, as well as the main measures on reducing the adverse effect of the power engineering equipment operation, is given. The results of original designs by the Department of Boiler Installations and Power Engineering Ecology (KU&EE) are given concerning the reduction of nitrogen oxides emissions and the decrease of the noise impact produced by the power engineering equipment.

  12. Guidelines for the Selection of Near-Earth Thermal Environment Parameters for Spacecraft Design

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Justus, C. G.; Batts, G. W.

    2001-01-01

    Thermal analysis and design of Earth orbiting systems requires specification of three environmental thermal parameters: the direct solar irradiance, Earth's local albedo, and outgoing longwave radiance (OLR). In the early 1990s data sets from the Earth Radiation Budget Experiment were analyzed on behalf of the Space Station Program to provide an accurate description of these parameters as a function of averaging time along the orbital path. This information, documented in SSP 30425 and, in more generic form in NASA/TM-4527, enabled the specification of the proper thermal parameters for systems of various thermal response time constants. However, working with the engineering community and SSP-30425 and TM-4527 products over a number of years revealed difficulties in interpretation and application of this material. For this reason it was decided to develop this guidelines document to help resolve these issues of practical application. In the process, the data were extensively reprocessed and a new computer code, the Simple Thermal Environment Model (STEM) was developed to simplify the process of selecting the parameters for input into extreme hot and cold thermal analyses and design specifications. In the process, greatly improved values for the cold case OLR values for high inclination orbits were derived. Thermal parameters for satellites in low, medium, and high inclination low-Earth orbit and with various system thermal time constraints are recommended for analysis of extreme hot and cold conditions. Practical information as to the interpretation and application of the information and an introduction to the STEM are included. Complete documentation for STEM is found in the user's manual, in preparation.

  13. The Study of Simulated Space Radiation Environment Effect on Conductive Properties of ITO Thermal Control Materials

    NASA Astrophysics Data System (ADS)

    Wei-Quan, Feng; Chun-Qing, Zhao; Zi-Cai, Shen; Yi-Gang, Ding; Fan, Zhang; Yu-Ming, Liu; Hui-Qi, Zheng; Xue, Zhao

    In order to prevent detrimental effects of ESD caused by differential surface charging of spacecraft under space environments, an ITO transparent conductive coating is often deposited on the thermal control materials outside spacecraft. Since the ITO coating is exposed in space environment, the environment effects on electrical property of ITO coatings concern designers of spacecraft deeply. This paper introduces ground tests to simulate space radiation environmental effects on conductive property of ITO coating. Samples are made of ITO/OSR, ITO/Kapton/Al and ITO/FEP/Ag thermal control coatings. Simulated space radiation environment conditions are NUV of 500ESH, 40 keV electron of 2 × 1016 е/cm2, 40 keV proton of 2.5 × 1015 p/cm2. Conductive property is surface resistivity measured in-situ in vacuum. Test results proved that the surface resistivity for all ITO coatings have a sudden decrease in the beginning of environment test. The reasons for it may be the oxygen vacancies caused by vacuum and decayed RIC caused by radiation. Degradation in conductive properties caused by irradiation were found. ITO/FEP/Ag exhibits more degradation than other two kinds. The conductive property of ITO/kapton/Al is stable for vacuum irradiation. The analysis of SEM and XPS found more crackers and less Sn and In concentration after irradiation which may be the reason for conductive property degradation.

  14. Gaussian geometric discord of two-mode systems in a thermal environment

    SciTech Connect

    Suciu, Serban Isar, Aurelian

    2014-11-24

    In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the Gaussian geometric discord for a system consisting of two non-interacting non-resonant bosonic modes embedded in a thermal environment. We take as initial state of the system a two-mode squeezed thermal state and describe the time evolution of the Gaussian geometric discord under the influence of the thermal bath. By tracing the distance between the state of the considered subsystem and the closest classical-quantum Gaussian state we evaluate the Gaussian geometric discord for all times and temperatures. The geometric discord has finite values between 0 and 1 and decreases asymptotically to zero at large times and temperatures with oscillations on the time axis.

  15. Thermal effects on human performance in office environment measured by integrating task speed and accuracy.

    PubMed

    Lan, Li; Wargocki, Pawel; Lian, Zhiwei

    2014-05-01

    We have proposed a method in which the speed and accuracy can be integrated into one metric of human performance. This was achieved by designing a performance task in which the subjects receive feedback on their performance by informing them whether they have committed errors, and if did, they can only proceed when the errors are corrected. Traditionally, the tasks are presented without giving this feedback and thus the speed and accuracy are treated separately. The method was examined in a subjective experiment with thermal environment as the prototypical example. During exposure in an office, 12 subjects performed tasks under two thermal conditions (neutral & warm) repeatedly. The tasks were presented with and without feedback on errors committed, as outlined above. The results indicate that there was a greater decrease in task performance due to thermal discomfort when feedback was given, compared to the performance of tasks presented without feedback. PMID:23871091

  16. Effects of asteroid and comet impacts on thermal environment and atmopsheric erosion

    NASA Astrophysics Data System (ADS)

    Wallemacq, Quentin; Gillmann, Cedric; Karatekin, Ozgur; Dehant, Veronique

    2016-04-01

    Asteroid and comet impacts have implications on the atmospheric and thermal evolution of terrestrial planets and hence on their habitability. They can affect the planetary evolution by eroding the mass of the atmosphere and by depositing energy at the surface. These effects depend on impactor and surface parameters, including composition, size, density and impactor velocity. In this study, we investigate the effects of impactors of various sizes on the environment and on the evolution of the mantle and atmosphere of terrestrial planets with a special emphasis on Mars. Models with different levels of complexity are used to explore the thermal effects and the atmospheric erosion ; They vary from semi-analytical models to fully coupled subsurface/atmosphere numerical codes. While small impactors with relatively small velocities have only local and time-limited effects, large impactors can create a strong thermal anomaly affecting both the crust and the mantle, which can trigger a change in the dynamic patterns of the mantle.

  17. Effects of natural environment on first generation solid rocket booster thermal protection system materials

    NASA Technical Reports Server (NTRS)

    Webb, D. D.

    1988-01-01

    The effort to demonstrate, by real-time exposure, the effects of the natural environment at Kennedy Space Center, Florida, upon the Thermal Protection System (TPS) of the Solid Rocket Booster (SRB) is summarized, and that the overall SRB TPS configuration is verified to meet all requirements for resistance to the conditions associated with outdoor weathering, including: solar radiation; temperature; humidity; precipitation; wind; sand/dust abrasion; static electricity; salt spray; fungus; and atmospheric oxidants. The evaluation criterion for this project was based upon flatwise tensile properties, visual inspection, color change, and thermal performance. Based upon the evaluation of the changes in these properties, it is concluded that properly applied and topcoat-protected TPS can satisfactorily withstand the conditions of the natural environment at KSC for exposures up to six months.

  18. The effect of thermal treatment on the fracture properties of alloy X-750 in aqueous environments

    SciTech Connect

    Ballinger, R.; Elliott, C.S.; Hwang, I.S.; Prybylowski, J.

    1993-05-01

    Alloy X-750 is a high strength, age hardenable nickel-base alloy used in light water nuclear reactors. The excellent corrosion resistance and high temperature strength of alloy X-750 make it suitable for use in a variety of structure components in both pressurized water reactors and boiling water reactors. These applications involve exposure of highly stressed material to aqueous media. Operational stresses are subject to low frequency thermally induced fluctuations and high frequency flow induced fluctuations. In general, alloy X-750 has performed well in light water reactors. However, an economically significant number of components have failed unexpectedly due to localized forms of attack such as corrosion fatigue and stress corrosion cracking. Thermal processing history is known to play a significant role in the fracture properties of alloy X-750 in aqueous environments. While thermal treatments have been developed recently to improve performance, in many cases the reason for improved performance remains unclear. Therefore, identification of the mechanisms responsible for the degradation of fracture properties in aqueous environments is necessary. As a corollary it is necessary to achieve an understanding of how thermal treatment influences microstructure and, in turn, how microstructure influences fracture properties in aqueous environments. This report discusses five thermal treatments which were studied: (1) SA-1 hr at 1093{degree}C, (2) AH - 24 hr at 885{degree}C + 20 hr at 704{degree}C, (3) HTH - 1 hr at 1093{degree}C + 20 hr at 704{degree}C, (4) AHTH - 1 hr at 1093{degree}C + 24 hr at 885{degree}C + 20 hr at 704{degree}C, and (5) HOA - 1 hr at 1093{degree}C + 100 hrs at 760{degree}C. Microstructural characterization of these materials was accomplished through the use of optical microscopy, transmission electron microscopy,scanning transmission electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffractometry.

  19. An Internal Thermal Environment Model of an Aluminized Solid Rocket Motor with Experimental Validation

    NASA Technical Reports Server (NTRS)

    Martin, Heath T.

    2015-01-01

    Due to the severity of the internal solid rocket motor (SRM) environment, very few direct measurements of that environment exist; therefore, the appearance of such data provides a unique opportunity to assess current thermal/fluid modeling capabilities. As part of a previous study of SRM internal insulation performance, the internal thermal environment of a laboratory-scale SRM featuring aluminized propellant was characterized with two types of custom heat-flux calorimeters: one that measured the total heat flux to a graphite slab within the SRM chamber and another that measured the thermal radiation flux. Therefore, in the current study, a thermal/fluid model of this lab-scale SRM was constructed using ANSYS Fluent to predict not only the flow field structure within the SRM and the convective heat transfer to the interior walls, but also the resulting dispersion of alumina droplets and the radiative heat transfer to the interior walls. The dispersion of alumina droplets within the SRM chamber was determined by employing the Lagrangian discrete phase model that was fully coupled to the Eulerian gas-phase flow. The P1-approximation was engaged to model the radiative heat transfer through the SRM chamber where the radiative contributions of the gas phase were ignored and the aggregate radiative properties of the alumina dispersion were computed from the radiative properties of its individual constituent droplets, which were sourced from literature. The convective and radiative heat fluxes computed from the thermal/fluid model were then compared with those measured in the lab-scale SRM test firings and the modeling approach evaluated.

  20. Thermal Properties of Starch From New Corn Lines as Impacted by Environment and During Line Development

    SciTech Connect

    Elizabeth M. Lenihan

    2003-12-12

    The objectives of this research were to further characterize exotic by adapted corn inbreds by studying the impact of environment on their starch thermal properties, and investigating the development of starch thermal properties during kernel maturation by using differential scanning calorimetry (DSC). A method to expedite identification of unusual starch thermal traits was investigated by examining five corn kernels at a time, instead of one kernel, which the previous screening methods used. Corn lines with known thermal functions were blended with background starch (control) in ratios of unique starch to control starch, and analyzed by using DSC. Control starch was representative of typical corn starch. The values for each ratio within a mutant type were unique ({alpha} < 0.01) for most DSC measurements. These results supported the five-kernel method for rapidly screening large amounts of corn germplasm to identify unusual starch traits. The effects of 5 growing locations on starch thermal properties from exotic by adapted corn and Corn Belt lines were studied using DSC. The warmest location, Missouri, generally produced starch with greater gelatinization onset temperature (T{sub oG}), narrower range of gelatinization (R{sub G}), and greater enthalpy of gelatinization ({Delta}H{sub G}). The coolest location, Illinois, generally resulted in starch with lower T{sub oG}, wider R{sub G}, and lower {Delta}H{sub G}. Starch from the Ames 1 farm had thermal properties similar to those of Illinois, whereas starch from the Ames 2 farm had thermal properties similar to those of Missouri. The temperature at Ames 2 may have been warmer since it was located near a river; however, soil type and quality also were different. Final corn starch structure and function change during development and maturity. Thus, the changes in starch thermal properties during 5 stages of endosperm development from exotic by adapted corn and Corn Belt lines at two locations were studied by using DSC

  1. The effects of urban stream improving the thermal environment in urban area

    NASA Astrophysics Data System (ADS)

    Park, Jin-Ki; Na, Sang-il; Park, Jong-hwa

    2012-10-01

    Urban areas create distinctive urban climates by Urban Heat Island (UHI) that is the temperature increase in urban areas compared to that in surrounding rural areas and is caused by number of factors, such as land use / land cover (LULC) change, concentration of population and increase anthropogenic heat. In general, the study of thermal environment in urban area focused on UHI intensity and phenomenon. Recently, climate improvement has been studied using water and green belt of urban, as interest in UHI phenomenon mitigation or enhancement has been increased. Therefore in this study, effects of urban stream on urban thermal environment were analyzed using remotely sensed data. The Landsat 7 ETM+ data acquired on 6 September 2009 were utilized to derive the surface Temperature (Ts) and surface energy balance using Surface Energy Balance Algorithms for Land (SEBAL) (Bastiaanssen et al., 1998). The surface energy budget consists of net radiation at the surface (Rn), sensible heat flux to the air (H), latent heat flux (LE) and soil heat flux (G). The net radiation flux is computed by subtracting all outgoing radiant fluxes (K↑: shortwave outgoing, L↑ longwave outgoing) from all incoming radiant fluxes (K↓ shortwave incoming, L↓: longwave incoming). This is given in the surface energy budget equation: Rn = H + LE + G = K↓ - K↑ + L↓ - L↑. The result indicates that the Ts of urban stream are1 °C lower than circumjacent urban area, LE flux of urban stream is higher than surrounding urban area. However, land covers of streamside and around stream with concrete, asphalt and barren belt are comprised of hot spot zone that deteriorates urban thermal environment. And urban stream does perform a role of cool spot zone that improves urban thermal environment.

  2. Spatio-temporal pattern analysis of urban thermal environment of different types of cities

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Liu, Huanjun; Zhang, Yuanzhi; Zhang, Xinle; Zang, Hongting; Hu, Wen

    2014-03-01

    Cities with different functions show variable thermal patterns. This study directs at horizontal contrasting the heat island effect of cities and towns in the same latitude. The data source was Landsat TM, by which the thermal infrared bands is used with the algorithm of ARTIS inversion of Heilongjiang Province to acquire the surface temperature of Ha-Qi different types of cities in 1995(1989), 2006 and 2010. In this paper we analyzed the land surface temperature(LST) of temporal, spatial and regional. The results show that a high zone is mainly centralized in the old city and industrial zone. Impervious surface increase leads to temperature rise. Relatively high and low zone fluctuation is due to human activities influence. Climate is one of the key factors to affect the LST, such as precipitation and drought. Through the analysis of urban thermal environment, the process of urbanization can be monitored, to provide accurate information for the quality evaluation of urban thermal environment and heat source survey.

  3. Field study of occupant comfort and office thermal environments in a hot, arid climate

    SciTech Connect

    Cena, K.; Dear, R.J. de

    1999-07-01

    This paper presents the main findings of ASHRAE research project RP-921, a field study of occupant comfort and office thermal environment in 22 air-conditioned office buildings in Kalgoorlie-Boulder, Western Australia, a location characterized by a hot and arid climate. A total of 935 subjects provided 1,229 sets of data for winter and summer, each accompanied by a full set of indoor climatic measurements with laboratory-grade instrumentation. Clothing insulation estimates for seated subjects (0.5 clo in summer and 0.7 in winter) were supplemented by the incremental effect of chairs (0.15 clo). Thermal neutrality, according to responses on the ASHRAE seven-point sensation scale, occurred at 20.3 C in winter and at 23.3 C in summer. Preferred temperature, defined as a minimum of subjects requesting temperature change, was 22.2 C for both seasons. Nearly 65% of the indoor measurements fell within the ANSI/ASHRAE Standard 55a-1992 summer comfort zone and 85% in the winter. Over 85% of the occupants considered their thermal conditions acceptable. Subjects who expressed a below-average level of job satisfaction on a 15-question index were 50% more likely to express dissatisfaction with their thermal environment than subjects with above-average job satisfaction.

  4. A Multi-Environment Thermal Control System With Freeze-Tolerant Radiator

    NASA Technical Reports Server (NTRS)

    Chen, Weibo; Fogg, David; Mancini, Nick; Steele, John; Quinn, Gregory; Bue, Grant; Littibridge, Sean

    2013-01-01

    Future space exploration missions require advanced thermal control systems (TCS) to dissipate heat from spacecraft, rovers, or habitats operating in environments that can vary from extremely hot to extremely cold. A lightweight, reliable TCS is being developed to effectively control cabin and equipment temperatures under widely varying heat loads and ambient temperatures. The system uses freeze-tolerant radiators, which eliminate the need for a secondary circulation loop or heat pipe systems. Each radiator has a self-regulating variable thermal conductance to its ambient environment. The TCS uses a nontoxic, water-based working fluid that is compatible with existing lightweight aluminum heat exchangers. The TCS is lightweight, compact, and requires very little pumping power. The critical characteristics of the core enabling technologies were demonstrated. Functional testing with condenser tubes demonstrated the key operating characteristics required for a reliable, freeze-tolerant TCS, namely (1) self-regulating thermal conductance with short transient responses to varying thermal loads, (2) repeatable performance through freeze-thaw cycles, and (3) fast start-up from a fully frozen state. Preliminary coolant tests demonstrated that the corrosion inhibitor in the water-based coolant can reduce the corrosion rate on aluminum by an order of magnitude. Performance comparison with state-of-the-art designs shows significant mass and power saving benefits of this technology.

  5. AFLPs and Mitochondrial Haplotypes Reveal Local Adaptation to Extreme Thermal Environments in a Freshwater Gastropod

    PubMed Central

    Quintela, María; Johansson, Magnus P.; Kristjánsson, Bjarni K.; Barreiro, Rodolfo; Laurila, Anssi

    2014-01-01

    The way environmental variation shapes neutral and adaptive genetic variation in natural populations is a key issue in evolutionary biology. Genome scans allow the identification of the genetic basis of local adaptation without previous knowledge of genetic variation or traits under selection. Candidate loci for divergent adaptation are expected to show higher FST than neutral loci influenced solely by random genetic drift, migration and mutation. The comparison of spatial patterns of neutral markers and loci under selection may help disentangle the effects of gene flow, genetic drift and selection among populations living in contrasting environments. Using the gastropod Radix balthica as a system, we analyzed 376 AFLP markers and 25 mtDNA COI haplotypes for candidate loci and associations with local adaptation among contrasting thermal environments in Lake Mývatn, a volcanic lake in northern Iceland. We found that 2% of the analysed AFLP markers were under directional selection and 12% of the mitochondrial haplotypes correlated with differing thermal habitats. The genetic networks were concordant for AFLP markers and mitochondrial haplotypes, depicting distinct topologies at neutral and candidate loci. Neutral topologies were characterized by intense gene flow revealed by dense nets with edges connecting contrasting thermal habitats, whereas the connections at candidate loci were mostly restricted to populations within each thermal habitat and the number of edges decreased with temperature. Our results suggest microgeographic adaptation within Lake Mývatn and highlight the utility of genome scans in detecting adaptive divergence. PMID:25007329

  6. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    PubMed Central

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-01-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events. PMID:26627576

  7. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    PubMed

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-01-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events. PMID:26627576

  8. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    NASA Astrophysics Data System (ADS)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  9. Enhancing the photoelectrochemical properties of titanium dioxide by thermal treatment in oxygen deficient environment

    NASA Astrophysics Data System (ADS)

    Singh, Aadesh P.; Kodan, Nisha; Mehta, Bodh R.

    2016-05-01

    The effect of thermal treatment on TiO2 thin films under oxygen deficient environment (5% H2 in Ar) at partial pressure of 2 × 10-2 Torr have been studied for photoelectrochemical (PEC) water splitting application. Thermal treatment in anatase TiO2 thin films exhibits a shift in optical absorption from UV to visible region and activates TiO2 for water splitting application under visible light. X-ray photoelectron spectroscopy results showed that the thermal treated thin films contain oxygen vacancies, which suggests improved charge transport. Optical absorption, X-ray spectroscopy (XPS) and Kelvin probe force microscope (KPFM) studies show reduction in band gap by 0.36 eV, shift in valence band maximum by 0.49 eV towards the Fermi level and work function values by 0.3 eV towards the vacuum level. The pristine TiO2 thin films exhibit very less photoactivity in terms of photocurrent density, whereas thermally treated thin films displayed a markedly enhanced photocurrent density of ∼2.41 mA/cm2 at 0.23 V vs. Ag/AgCl. Higher values of photocurrent density in thermal treated TiO2 films have been explained in terms of change in the optical and electrical properties along with energy band diagram.

  10. Loss of Shallow Geothermal Resources in Urban Environment Due to the Absence of Thermal Management Policies

    NASA Astrophysics Data System (ADS)

    García-Gil, A.; Vázquez-Suñé, E.; Sánchez-Navarro, J. A.

    2014-12-01

    Shallow geothermal energy resources are of interest worldwide for the development of strategies against climate change. The current regulative framework for the sustainable implementation of the technologies exploiting this resources is facing several barriers. In the case of groundwater heat pumps, the thermal interference between exploitations may be endangering their feasibility in urban environments. Uncertainty in prediction of the sustainability of shallow geothermal energy development in urban groundwater bodies stems from the absence of a scientific-based legal regulatory framework which protects stakeholders from thermal interferences between existent exploitations systems. The present work consists of a numerical study aimed at understanding and predicting the thermal interference between groundwater heat pumps where several induced heat plumes in an urban ground water body coalesce, thus generating a heat island effect. A transient groundwater flow and heat transport model was developed to reproduce complex high-resolution data obtained from local monitoring specifically designed to control the aquifer respond to geothermal exploitation. The model aims to reproduce the groundwater flow and heat transport processes in a shallow alluvial aquifer exploited by 27 groundwater heat pumps and influenced by a river-aquifer relationship dominated by flood events mainly occurring in winter when the surface temperature is between 3 and 10 ºC. The results from the simulations have quantified the time-space thermal interference between exploitation systems and the consequences of river-aquifer thermal exchange. The results obtained showed the complexity of thermal management of the aquifer due to the transient activity of exploitations over space and time. With the actual exploitation regime of shallow geothermal resources in the investigated area the model predicts a temperature rising tendency in the production wells until 2019 which can compromise the coefficient

  11. Parental thermal environment alters offspring sex ratio and fitness in an oviparous lizard.

    PubMed

    Schwanz, Lisa E

    2016-08-01

    The environment experienced by parents can impact the phenotype of their offspring (parental effects), a critical component of organismal ecology and evolution in variable or changing environments. Although temperature is a central feature of the environment for ectotherms, its role in parental effects has been little explored until recently. Here, parental basking opportunity was manipulated in an oviparous lizard with temperature-dependent sex determination, the jacky dragon (Amphibolurus muricatus). Eggs were incubated at a temperature that typically produces a 50:50 sex ratio, and hatchlings were reared in a standard thermal environment. Offspring of parents in short bask conditions appeared to have better fitness outcomes in captive conditions than those of parents in long bask conditions - they had greater growth and survival as a function of their mass. In addition, the sex of offspring (male or female) depended on the interaction between parental treatment and egg mass, and treatment impacted whether sons or daughters grew larger in their first season. The interactive effects of treatment on offspring sex and growth are consistent with adaptive explanations for the existence of temperature-dependent sex determination in this species. Moreover, the greater performance recorded in short bask offspring may represent an anticipatory parental effect to aid offspring in predicted conditions of restricted thermal opportunity. Together, these responses constitute a crucial component of the population response to spatial or temporal variation in temperature. PMID:27229475

  12. Does the restoration of an inner-city stream in Seoul affect local thermal environment?

    NASA Astrophysics Data System (ADS)

    Kim, Y.-H.; Ryoo, S.-B.; Baik, J.-J.; Park, I.-S.; Koo, H.-J.; Nam, J.-C.

    2008-05-01

    Changes in local thermal environment associated with the restoration of an inner-city stream in Seoul, Korea, are investigated using observational data. The stream, called the Cheonggye stream, which had been hidden and covered with cement/asphalt for 46 years, runs 5.8 km eastward through a central region of Seoul. Intensive observations were made in the stream area for a number of summertime periods before, during, and after the stream restoration to detect the effects of the stream on local environment and to quantify them. It is estimated that after the stream restoration the near-surface temperature averaged over the stream area dropped by 0.4 °C, with the largest local temperature drop being 0.9 °C. However, it cannot be stated that this 0.4 °C temperature drop is due entirely to the stream effect only, because synoptic-scale and local-scale weather conditions during the two periods were inevitably not identical. The stream effect on air temperature is also evident in the temperature distribution along a street traversing the stream. In the daytime after the stream restoration, the sensible heat flux was greatly reduced and the ratio of sensible heat flux to net radiative flux dramatically decreased. These first-time results of the restored-stream effects on urban thermal environment could contribute to the scientific basis of urban planning which aims to make a large city comfortable to live in and nature- and environment-friendly.

  13. Complex Genotype by Environment interactions and changing genetic architectures across thermal environments in the Australian field cricket, Teleogryllus oceanicus

    PubMed Central

    2011-01-01

    Background Biologists studying adaptation under sexual selection have spent considerable effort assessing the relative importance of two groups of models, which hinge on the idea that females gain indirect benefits via mate discrimination. These are the good genes and genetic compatibility models. Quantitative genetic studies have advanced our understanding of these models by enabling assessment of whether the genetic architectures underlying focal phenotypes are congruent with either model. In this context, good genes models require underlying additive genetic variance, while compatibility models require non-additive variance. Currently, we know very little about how the expression of genotypes comprised of distinct parental haplotypes, or how levels and types of genetic variance underlying key phenotypes, change across environments. Such knowledge is important, however, because genotype-environment interactions can have major implications on the potential for evolutionary responses to selection. Results We used a full diallel breeding design to screen for complex genotype-environment interactions, and genetic architectures underlying key morphological traits, across two thermal environments (the lab standard 27°C, and the cooler 23°C) in the Australian field cricket, Teleogryllus oceanicus. In males, complex three-way interactions between sire and dam parental haplotypes and the rearing environment accounted for up to 23 per cent of the scaled phenotypic variance in the traits we measured (body mass, pronotum width and testes mass), and each trait harboured significant additive genetic variance in the standard temperature (27°C) only. In females, these three-way interactions were less important, with interactions between the paternal haplotype and rearing environment accounting for about ten per cent of the phenotypic variance (in body mass, pronotum width and ovary mass). Of the female traits measured, only ovary mass for crickets reared at the cooler

  14. Methylammonium methylcarbamate thermal formation in interstellar ice analogs: a glycine salt precursor in protostellar environments

    NASA Astrophysics Data System (ADS)

    Bossa, J.-B.; Duvernay, F.; Theulé, P.; Borget, F.; D'Hendecourt, L.; Chiavassa, T.

    2009-11-01

    Context: Analyses of dust cometary grains collected by the Stardust spacecraft have shown the presence of amines and amino acids molecules, and among them glycine (NH{2}CH{2}COOH). We show how the glycine molecule could be produced in the protostellar environments before its introduction into comets. Aims: We study the evolution of the interstellar ice analogues affected by both thermal heating and vacuum ultraviolet (VUV) photons, in addition to the nature of the formed molecules and the confrontation of our experimental results with astronomical observations. Methods: Infrared spectroscopy and mass spectrometry are used to monitor the evolution of the H{2}O:CO{2}:CH{3}NH{2} and CO{2}:CH{3}NH{2} ice mixtures during both warming processes and VUV photolysis. Results: We first show how carbon dioxide (CO{2}) and methylamine (CH{3}NH{2}) thermally react in water-dominated ice to form methylammonium methylcarbamate [ CH{3}NH{3}+] [ CH{3}NHCOO-] noted C. We then determine the reaction rate and activation energy. We show that C thermal formation can occurs in the 50-70 K temperature range of a protostellar environment. Secondly, we report that a VUV photolysis of a pure C sample produces a glycine salt, methylammonium glycinate [ CH{3}NH{3}+] [ NH{2}CH{2}COO-] noted G. We propose a scenario explaining how C and subsequently G can be synthesized in interstellar ices and precometary grains. Conclusions: [ CH{3}NH{3}+] [ CH{3}NHCOO-] could be readily formed and would act as a glycine salt precursor in protostellar environments dominated by thermal and UV processing. We propose a new pathway leading to a glycine salt, which is consistent with the detection of glycine and methylamine within the returned samples of comet 81P/Wild 2 from the Stardust mission.

  15. Fluctuating temperature leads to evolution of thermal generalism and preadaptation to novel environments.

    PubMed

    Ketola, Tarmo; Mikonranta, Lauri; Zhang, Ji; Saarinen, Kati; Ormälä, Anni-Maria; Friman, Ville-Petri; Mappes, Johanna; Laakso, Jouni

    2013-10-01

    Environmental fluctuations can select for generalism, which is also hypothesized to increase organisms' ability to invade novel environments. Here, we show that across a range of temperatures, opportunistic bacterial pathogen Serratia marcescens that evolved in fluctuating temperature (daily variation between 24°C and 38°C, mean 31°C) outperforms the strains that evolved in constant temperature (31°C). The growth advantage was also evident in novel environments in the presence of parasitic viruses and predatory protozoans, but less clear in the presence of stressful chemicals. Adaptation to fluctuating temperature also led to reduced virulence in Drosophila melanogaster host, which suggests that generalism can still be costly in terms of reduced fitness in other ecological contexts. While supporting the hypothesis that evolution of generalism is coupled with tolerance to several novel environments, our results also suggest that thermal fluctuations driven by the climate change could affect both species' invasiveness and virulence. PMID:24094344

  16. Thermal Properties and Structural Stability of LaCoO3 in Reducing and Oxidizing Environments

    SciTech Connect

    Radovic, Miladin; Speakman, Scott A; Allard Jr, Lawrence Frederick; Payzant, E Andrew; Lara-Curzio, Edgar; Kriven, Waltraud M; Lloyd, John; Fegely, Laura C; Orlovskaya, Nina

    2008-09-01

    Thermal expansion of LaCoO3 perovskite in air and 4% H2/96% Ar reducing atmosphere has been studied by Thermal Mechanical Analysis (TMA). The thermal behavior of LaCoO3 in air exhibits a non-linear expansion in 100 400 C temperature range. A significant increase of CTE measured in air both during heating and cooling experiments occurs in the 200 250 C temperature range, corresponding to a known spin state transition. LaCoO3 is found to be unstable in a reducing atmosphere. It undergoes a series of expansion and contractions due to phase transformations beginning around 500 C with very intensive chemical/phase changes at 850oC and above. These expansions and contractions are directly related to the formation of La3Co3O8, La2CoO4, La4Co3O10, La2O3, CoO, and other Co compounds due to the reducing atmosphere. Although LaCoO3 is a good ionic and electronic conductor and catalyst, its high thermal expansion as well structural instability in reducing environments presents a serious restriction for its application in solid oxide fuel cells, sensors or gas separation membranes.

  17. The physiological equivalent temperature - a universal index for the biometeorological assessment of the thermal environment.

    PubMed

    Höppe, P

    1999-10-01

    With considerably increased coverage of weather information in the news media in recent years in many countries, there is also more demand for data that are applicable and useful for everyday life. Both the perception of the thermal component of weather as well as the appropriate clothing for thermal comfort result from the integral effects of all meteorological parameters relevant for heat exchange between the body and its environment. Regulatory physiological processes can affect the relative importance of meteorological parameters, e.g. wind velocity becomes more important when the body is sweating. In order to take into account all these factors, it is necessary to use a heat-balance model of the human body. The physiological equivalent temperature (PET) is based on the Munich Energy-balance Model for Individuals (MEMI), which models the thermal conditions of the human body in a physiologically relevant way. PET is defined as the air temperature at which, in a typical indoor setting (without wind and solar radiation), the heat budget of the human body is balanced with the same core and skin temperature as under the complex outdoor conditions to be assessed. This way PET enables a layperson to compare the integral effects of complex thermal conditions outside with his or her own experience indoors. On hot summer days, for example, with direct solar irradiation the PET value may be more than 20 K higher than the air temperature, on a windy day in winter up to 15 K lower. PMID:10552310

  18. Time dependent quantum thermodynamics of a coupled quantum oscillator system in a small thermal environment

    SciTech Connect

    Barnes, George L.; Kellman, Michael E.

    2013-12-07

    Simulations are performed of a small quantum system interacting with a quantum environment. The system consists of various initial states of two harmonic oscillators coupled to give normal modes. The environment is “designed” by its level pattern to have a thermodynamic temperature. A random coupling causes the system and environment to become entangled in the course of time evolution. The approach to a Boltzmann distribution is observed, and effective fitted temperatures close to the designed temperature are obtained. All initial pure states of the system are driven to equilibrium at very similar rates, with quick loss of memory of the initial state. The time evolution of the von Neumann entropy is calculated as a measure of equilibration and of quantum coherence. It is pointed out using spatial density distribution plots that quantum interference is eliminated only with maximal entropy, which corresponds thermally to infinite temperature. Implications of our results for the notion of “classicalizing” behavior in the approach to thermal equilibrium are briefly considered.

  19. Time dependent quantum thermodynamics of a coupled quantum oscillator system in a small thermal environment.

    PubMed

    Barnes, George L; Kellman, Michael E

    2013-12-01

    Simulations are performed of a small quantum system interacting with a quantum environment. The system consists of various initial states of two harmonic oscillators coupled to give normal modes. The environment is "designed" by its level pattern to have a thermodynamic temperature. A random coupling causes the system and environment to become entangled in the course of time evolution. The approach to a Boltzmann distribution is observed, and effective fitted temperatures close to the designed temperature are obtained. All initial pure states of the system are driven to equilibrium at very similar rates, with quick loss of memory of the initial state. The time evolution of the von Neumann entropy is calculated as a measure of equilibration and of quantum coherence. It is pointed out using spatial density distribution plots that quantum interference is eliminated only with maximal entropy, which corresponds thermally to infinite temperature. Implications of our results for the notion of "classicalizing" behavior in the approach to thermal equilibrium are briefly considered. PMID:24320365

  20. Field study on the thermal environment of passive cooling system in RC building

    SciTech Connect

    Zhou, Nan; Gao, Weijun; Nishida, Masaru; Kitayama, Hiroki; Ojima, Toshio

    2004-10-30

    In recent years, various passive methods have come to be adopted in architecture design. The rooftop lawn is seen to have merit in the reduction in the air conditioning load of the building, as well as contributing to the mitigation of the heat island phenomenon. The roofs praying system is seen to be an effective method for the roof of low heat insulation performance, and can greatly reduce the heat load in the summer season. However, at present most of the buildings with an RC construction have the insulating material in the roof for providing thermal insulation in the winter season. There has been a trend to adopt the roof spraying system actively in even such a general RC building, but it is not clear how much actual effect it has. In this study, the authors conducted a measurement in an RC building with a rooftop spraying system and roof lawn in order to clarify the effects and problems on the thermal environment.

  1. Effects of the specular Orbiter forward radiators on a typical Spacelab payload thermal environment

    NASA Technical Reports Server (NTRS)

    Turner, L. D.; Humphries, W. R.; Littles, J. W.

    1981-01-01

    Orbiter radiators, having a specular reflection, must be considered when determining the design environment for payloads which can view the forward deployed radiators. Unlike most surfaces on the Orbiter, which reflect energy diffusely, the radiators are covered with a highly specular silverized Teflon material, with high emissivity, and have a concave contour, producing a local concentration of reflected energy towards the region of angle incidence. The combined effects of radiator specularity and geometry were analyzed using the Thermal Radiation Analysis System (TRASYS II), a specialized ray trace program, and a generalized Monte-Carlo-based thermal radiation program. Data given for a 0 deg payload inclination angle at orbital noon at 3.454 m indicate that the maximum total flux and average flux can increase 173% and 63%, respectively, when compared to diffuse radiators.

  2. Integrity evaluation of lower thermal shield under exposure to HFBR environment

    SciTech Connect

    Kassir, M.; Weeks, J.; Bandyopadhyay, K.; Shewmon, P.

    1998-01-01

    The effects of exposure to the HFBR environment on the carbon steel in the HFBR lower thermal shield were evaluated. Corrosion was found to be a non-significant degradation process. Radiation embrittlement has occurred; portions of the plate closest to the reactor are currently operating in the lower-shelf region of the Charpy impact curve (i.e., below the fracture toughness transition temperature). In this region, the effects of radiation on the mechanical properties of carbon steel are believed to have been saturated, so that no further deterioration is anticipated. A fracture toughness analysis shows that a large factor of safety (> 1.5) exists against propagation of credible hypothetical flaws. Therefore, the existing lower thermal shield structure is suitable for continued operation of the HFBR.

  3. Life testing of reflowed and reworked advanced CCGA surface mount packages in harsh thermal environments

    NASA Astrophysics Data System (ADS)

    Ramesham, Rajeshuni

    2013-03-01

    Life testing/qualification of reflowed (1st reflow) and reworked (1st reflow, 1st removal, and then 1st rework) advanced ceramic column grid array (CCGA) surface mount interconnect electronic packaging technologies for future flight projects has been studied to enhance the mission assurance of JPL-NASA projects. The reliability of reworked/reflowed surface mount technology (SMT) packages is very important for short-duration and long-duration deep space harsh extreme thermal environmental missions. The life testing of CCGA electronic packages under extreme thermal environments (for example: -185°C to +125°C) has been performed with reference to various JPL/NASA project requirements which encompass the temperature range studied. The test boards of reflowed and reworked CCGA packages (717 Xilinx package, 624, 1152, and 1272 column Actel Packages) were selected for the study to survive three times the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations, and mission phases or cycles to failure to assess the life of the hardware. Qualification/life testing was performed by subjecting test boards to the environmental harsh temperature extremes and assessing any structural failures, mechanical failures or degradation in electrical performance solder-joint failures due to either overstress or thermal cycle fatigue. The large, high density, high input/output (I/O) electronic interconnect SMT packages such as CCGA have increased usage in avionics hardware of NASA projects during the last two decades. The test boards built with CCGA packages are expensive and often require a rework to replace a reflowed, reprogrammed, failed, redesigned, etc., CCGA packages. Theoretically speaking, a good rework process should have similar temperature-time profile as that used for the original manufacturing process of solder reflow. A

  4. Thermal environment effects on strength and impact properties of boron-aluminum composites

    NASA Technical Reports Server (NTRS)

    Grimes, H. H.; Lad, R. A.; Maisel, J. E.

    1978-01-01

    A systematic study was conducted regarding the degradation of fracture strength and impact energy in commercial B-Al composites in both static and cyclic thermal environments. The composites used in the study contained approximately 50 vol % boron fibers, unidirectionally aligned in either a 6061 Al or 1100 Al matrix. The tensile strengths of the composites after 3000 thermal cycles as a function of upper cycle temperature are presented in graphs. The temperature at which the strengths of 6061 Al matrix, B-Al composites were significantly degraded after 3000 cycles was noticeably higher than that for the 1100 Al matrix composites. Static heating at 420 C resulted in no significant strength degradation for the 6061 Al matrix composites. In the case of 1100 matrix composites, some degradation was observed at 420 C but markedly less than in the composites cycled to 420 C.

  5. A unified formulation for dynamic analysis of nonlocal heterogeneous nanobeams in hygro-thermal environment

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Farzad; Barati, Mohammad Reza

    2016-09-01

    In this article, combined effect of moisture and temperature on free vibration characteristics of functionally graded (FG) nanobeams resting on elastic foundation is investigated by developing various refined beam theories which capture shear deformation influences needless of any shear correction factor. The material properties of FG nanobeam are temperature dependent and change gradually along the thickness through the power-law model. Size-dependent description of the nanobeam is performed applying nonlocal elasticity theory of Eringen. Nonlocal governing equations of embedded FG nanobeam in hygro-thermal environment obtained from Hamilton's principle are solved analytically. To verify the validity of the developed theories, the results of the present work are compared with those available in the literature. The effects of various hygro-thermal loadings, elastic foundation, gradient index, nonlocal parameter, and slenderness ratio on the vibrational behavior of FG nanobeams modeled via various beam theories are explored.

  6. Potential of a New Lunar Surface Radiator Concept for Hot Lunar Thermal Environments

    NASA Technical Reports Server (NTRS)

    Ochoa, Dustin A.; Vogel, Matthew R.; Trevino, Luis A.; Stephan, Ryan A.

    2008-01-01

    The optimum radiator configuration in hot lunar thermal environments is one in which the radiator is parallel to the ground and has no view to the hot lunar surface. However, typical spacecraft configurations have limited real estate available for top-mounted radiators, resulting in a desire to use the spacecraft s vertically oriented sides. Vertically oriented, flat panel radiators will have a large view factor to the lunar surface, and thus will be subjected to significant incident lunar infrared heat. Consequently, radiator fluid temperatures will need to exceed approx.325 K (assuming standard spacecraft radiator optical properties) in order to provide positive heat rejection at lunar noon. Such temperatures are too high for crewed spacecraft applications in which a heat pump is to be avoided. A recent study of vertically oriented radiator configurations subjected to lunar noon thermal environments led to the discovery of a novel radiator concept that yielded positive heat rejection at lower fluid temperatures. This radiator configuration, called the Upright Lunar Terrain Radiator Assembly (ULTRA), has exhibited superior performance to all previously analyzed concepts in terms of heat rejection in the lunar noon thermal environment. A key benefit of the ULTRA is the absence of louvers or other moving parts and its simple geometry. Analysis of the ULTRA for a lunar extravehicular activity (EVA) portable life support system (PLSS) is shown to provide moderate heat rejection, on average, at all solar incident angles assuming an average radiator temperature of 294 K, whereas prior concepts exhibited insignificant heat rejection or heat absorption at higher incident angles. The performance of the ULTRA for a lunar lander is also discussed and compared to the performance of a vertically oriented, flat panel radiator at various lunar latitudes.

  7. PICARD payload thermal control system and general impact of the space environment on astronomical observations

    NASA Astrophysics Data System (ADS)

    Meftah, M.; Irbah, A.; Hauchecorne, A.; Hochedez, J.-F.

    2013-05-01

    PICARD is a spacecraft dedicated to the simultaneous measurement of the absolute total and spectral solar irradiance, the diameter, the solar shape, and to probing the Sun's interior by the helioseismology method. The mission has two scientific objectives, which are the study of the origin of the solar variability, and the study of the relations between the Sun and the Earth's climate. The spacecraft was successfully launched, on June 15, 2010 on a DNEPR-1 launcher. PICARD spacecraft uses the MYRIADE family platform, developed by CNES to use as much as possible common equipment units. This platform was designed for a total mass of about 130 kg at launch. This paper focuses on the design and testing of the TCS (Thermal Control System) and in-orbit performance of the payload, which mainly consists in two absolute radiometers measuring the total solar irradiance, a photometer measuring the spectral solar irradiance, a bolometer, and an imaging telescope to determine the solar diameter and asphericity. Thermal control of the payload is fundamental. The telescope of the PICARD mission is the most critical instrument. To provide a stable measurement of the solar diameter over three years duration of mission, telescope mechanical stability has to be excellent intrinsically, and thermally controlled. Current and future space telescope missions require ever-more dimensionally stable structures. The main scientific performance related difficulty was to ensure the thermal stability of the instruments. Space is a harsh environment for optics with many physical interactions leading to potentially severe degradation of optical performance. Thermal control surfaces, and payload optics are exposed to space environmental effects including contamination, atomic oxygen, ultraviolet radiation, and vacuum temperature cycling. Environmental effects on the performance of the payload will be discussed. Telescopes are placed on spacecraft to avoid the effects of the Earth atmosphere on

  8. Mathematical modelling of thermal process to aquatic environment with different hydrometeorological conditions.

    PubMed

    Issakhov, Alibek

    2014-01-01

    This paper presents the mathematical model of the thermal process from thermal power plant to aquatic environment of the reservoir-cooler, which is located in the Pavlodar region, 17 Km to the north-east of Ekibastuz town. The thermal process in reservoir-cooler with different hydrometeorological conditions is considered, which is solved by three-dimensional Navier-Stokes equations and temperature equation for an incompressible flow in a stratified medium. A numerical method based on the projection method, divides the problem into three stages. At the first stage, it is assumed that the transfer of momentum occurs only by convection and diffusion. Intermediate velocity field is solved by fractional steps method. At the second stage, three-dimensional Poisson equation is solved by the Fourier method in combination with tridiagonal matrix method (Thomas algorithm). Finally, at the third stage, it is expected that the transfer is only due to the pressure gradient. Numerical method determines the basic laws of the hydrothermal processes that qualitatively and quantitatively are approximated depending on different hydrometeorological conditions. PMID:24991644

  9. Anthropogenic effects on the subsurface thermal and groundwater environments in Osaka, Japan and Bangkok, Thailand.

    PubMed

    Taniguchi, Makoto; Shimada, Jun; Fukuda, Yoichi; Yamano, Makoto; Onodera, Shin-ichi; Kaneko, Shinji; Yoshikoshi, Akihisa

    2009-04-15

    Anthropogenic effects in both Osaka and Bangkok were evaluated to compare the relationships between subsurface environment and the development stage of both cities. Subsurface thermal anomalies due to heat island effects were found in both cities. The Surface Warming Index (SWI), the departure depth from the steady geothermal gradient, was used as an indicator of the heat island effect. SWI increases (deeper) with the magnitude of heat island effect and the elapsed time starting from the surface warming. Distributions of subsurface thermal anomalies due to the heat island effect agreed well with the distribution of changes in air temperature due to the same process, which is described by the distribution of population density in both Osaka and Bangkok. Different time lags between groundwater depression and subsidence in the two cities was found. This is attributed to differences in hydrogeologic characters, such as porosity and hydraulic conductivity. We find that differences in subsurface degradations in Osaka and Bangkok, including subsurface thermal anomalies, groundwater depression, and land subsidence, depends on the difference of the development stage of urbanization and hydrogeological characters. PMID:18790519

  10. Mathematical Modelling of Thermal Process to Aquatic Environment with Different Hydrometeorological Conditions

    PubMed Central

    Issakhov, Alibek

    2014-01-01

    This paper presents the mathematical model of the thermal process from thermal power plant to aquatic environment of the reservoir-cooler, which is located in the Pavlodar region, 17 Km to the north-east of Ekibastuz town. The thermal process in reservoir-cooler with different hydrometeorological conditions is considered, which is solved by three-dimensional Navier-Stokes equations and temperature equation for an incompressible flow in a stratified medium. A numerical method based on the projection method, divides the problem into three stages. At the first stage, it is assumed that the transfer of momentum occurs only by convection and diffusion. Intermediate velocity field is solved by fractional steps method. At the second stage, three-dimensional Poisson equation is solved by the Fourier method in combination with tridiagonal matrix method (Thomas algorithm). Finally, at the third stage, it is expected that the transfer is only due to the pressure gradient. Numerical method determines the basic laws of the hydrothermal processes that qualitatively and quantitatively are approximated depending on different hydrometeorological conditions. PMID:24991644

  11. Thermal history sensors for non-destructive temperature measurements in harsh environments

    SciTech Connect

    Pilgrim, C. C.; Heyes, A. L.; Feist, J. P.

    2014-02-18

    The operating temperature is a critical physical parameter in many engineering applications, however, can be very challenging to measure in certain environments, particularly when access is limited or on rotating components. A new quantitative non-destructive temperature measurement technique has been proposed which relies on thermally induced permanent changes in ceramic phosphors. This technique has several distinct advantages over current methods for many different applications. The robust ceramic material stores the temperature information allowing long term thermal exposures in harsh environment to be measured at a convenient time. Additionally, rare earth dopants make the ceramic phosphorescent so that the temperature information can be interpreted by automated interrogation of the phosphorescent light. This technique has been demonstrated by application of YAG doped with dysprosium and europium as coatings through the air-plasma spray process. Either material can be used to measure temperature over a wide range, namely between 300°C and 900°C. Furthermore, results show that the material records the peak exposure temperature and prolonged exposure at lower temperatures would have no effect on the temperature measurement. This indicates that these materials could be used to measure peak operating temperatures in long-term testing.

  12. SRB thermal protection systems materials test results in an arc-heated nitrogen environment

    NASA Technical Reports Server (NTRS)

    Wojciechowski, C. J.

    1979-01-01

    The external surface of the Solid Rocket Booster (SRB) will experience imposed thermal and shear environments due to aerodynamic heating and radiation heating during launch, staging and reentry. This report is concerned with the performance of the various TPS materials during the staging maneuver. During staging, the wash from the Space Shuttle Main Engine (SSME) exhust plumes impose severe, short duration, thermal environments on the SRB. Five different SRB TPS materials were tested in the 1 MW Arc Plasma Generator (APG) facility. The maximum simulated heating rate obtained in the APG facility was 248 Btu/sq ft./sec, however, the test duration was such that the total heat was more than simulated. Similarly, some local high shear stress levels of 0.04 psia were not simulated. Most of the SSME plume impingement area on the SRB experiences shear stress levels of 0.02 psia and lower. The shear stress levels on the test specimens were between 0.021 and 0.008 psia. The SSME plume stagnation conditions were also simulated.

  13. Reliability of High I/O High Density CCGA Interconnect Electronic Packages under Extreme Thermal Environment

    NASA Technical Reports Server (NTRS)

    Ramesham, Rajeshuni

    2012-01-01

    This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non

  14. Differentially expressed genes associated with adaptation to different thermal environments in three sympatric Cuban Anolis lizards.

    PubMed

    Akashi, Hiroshi D; Cádiz Díaz, Antonio; Shigenobu, Shuji; Makino, Takashi; Kawata, Masakado

    2016-05-01

    How animals achieve evolutionary adaptation to different thermal environments is an important issue for evolutionary biology as well as for biodiversity conservation in the context of recent global warming. In Cuba, three sympatric species of Anolis lizards (Anolis allogus, A. homolechis and A. sagrei) inhabit different thermal microhabitats, thereby providing an excellent opportunity to examine how they have adapted to different environmental temperatures. Here, we performed RNA-seq on the brain, liver and skin tissues from these three species to analyse their transcriptional responses at two different temperatures. In total, we identified 400, 816 and 781 differentially expressed genes (DEGs) between the two temperatures in A. allogus, A. homolechis and A. sagrei, respectively. Only 62 of these DEGs were shared across the three species, indicating that global transcriptional responses have diverged among these species. Gene ontology (GO) analysis showed that large numbers of ribosomal protein genes were DEGs in the warm-adapted A. homolechis, suggesting that the upregulation of protein synthesis is an important physiological mechanism in the adaptation of this species to hotter environments. GO analysis also showed that GO terms associated with circadian regulation were enriched in all three species. A gene associated with circadian regulation, Nr1d1, was detected as a DEG with opposite expression patterns between the cool-adapted A. allogus and the hot-adapted A. sagrei. Because the environmental temperature fluctuates more widely in open habitats than in forests throughout the day, the circadian thermoregulation could also be important for adaptation to distinct thermal habitats. PMID:27027506

  15. Relevance of thermal environment to human health: a case study of Ondo State, Nigeria

    NASA Astrophysics Data System (ADS)

    Omonijo, Akinyemi Gabriel; Adeofun, Clement Olabinjo; Oguntoke, Olusegun; Matzarakis, Andreas

    2013-07-01

    The interconnection between weather and climate and the performance, well-being, and human health cannot be overemphasized. The relationship between them is of both local and global significance. Information about weather, climate, and thermal environment is very important to human health and medical practitioners. The most crucial environmental information needed by medical practitioners and for maintaining human health, performance, and well-being are thermal conditions. The study used meteorological variables: air temperature, relative humidity, wind speed, solar radiation, and RayMan model as an analytical tool to compute physiologically equivalent temperature (PET) in order to assess thermo-physiological thresholds in Ondo State. The study revealed that there are marked spatial and seasonal variations in the environmental thermal conditions in the study area. The results of physiologically equivalent temperature for different grades of thermal sensation and physiological stress on human beings indicate that about 60 % of the total study period (1998-2008) fall under physiological stress level of moderate heat stress (PET 31-36 °C). In derived savannah, 32.6 % out of the total study period was under strong heat stress. In view of this, the study concluded that Ondo State may likely be prone to heat-related ailments and that some of the death recorded in the State, in recent times, may be heat-related mortality, but this is difficult to ascertain because there is no postmortem records in Nigeria where it could be confirmed. This type of study is relevant to help government to improve health care interventions and achieve Millennium Development Goals in health sector.

  16. Reliability of high I/O high density CCGA interconnect electronic packages under extreme thermal environments

    NASA Astrophysics Data System (ADS)

    Ramesham, Rajeshuni

    2012-03-01

    Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surfacemount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions.

  17. Reconstruction of the thermal environment evolution in urban areas from underground temperature distribution.

    PubMed

    Yamano, Makoto; Goto, Shusaku; Miyakoshi, Akinobu; Hamamoto, Hideki; Lubis, Rachmat Fajar; Monyrath, Vuthy; Taniguchi, Makoto

    2009-04-15

    It is possible to estimate the ground surface temperature (GST) history of the past several hundred years from temperature profiles measured in boreholes because the temporal variation in GST propagates into the subsurface by thermal diffusion. This "geothermal method" of reconstructing GST histories can be applied to studies of thermal environment evolution in urban areas, including the development of "heat islands." Temperatures in boreholes were logged at 102 sites in Bangkok, Jakarta, Taipei, Seoul and their surrounding areas in 2004 to 2007. The effects of recent surface warming can be recognized in the shapes of most of the obtained temperature profiles. The preliminary results of reconstruction of GST histories through inversion analysis show that GST increased significantly in the last century. Existing temperature profile data for the areas in and around Tokyo and Osaka can also be used to reconstruct GST histories. Because most of these cities are located on alluvial plains in relatively humid areas, it is necessary to use a model with groundwater flow and a layered subsurface structure for reconstruction analysis. Long-term records of subsurface temperatures at multiple depths may demonstrate how the GST variation propagates downward through formations. Time series data provide information on the mechanism of heat transfer (conduction or advection) and the thermal diffusivity. Long-term temperature monitoring has been carried out in a borehole located on the coast of Lake Biwa, Japan. Temperatures at 30 and 40 m below the ground surface were measured for 4 years and 2 years, respectively, with a resolution of 1 mK. The obtained records indicate steady increases at both depths with different rates, which is probably the result of some recent thermal event(s) near the surface. Borehole temperatures have also been monitored at selected sites in Bangkok, Jakarta, and Taiwan. PMID:19091386

  18. Creating the Thermal Environment for Safely Testing the James Webb Space Telescope at the Johnson Space Center's Chamber A

    NASA Technical Reports Server (NTRS)

    Homan, Jonathan L.; Lauterbach, John; Garcia, Sam

    2016-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. The chamber was originally built to support testing of the Apollo Service and Command Module for lunar missions, but underwent major modifications to be able to test the James Webb Space Telescope in a simulated deep space environment. To date seven tests have been performed in preparation of testing the flight optics for the James Webb Space Telescope (JWST). Each test has had a uniquie thermal profile and set of thermal requirements for cooling down and warming up, controlling contamination, and releasing condensed air. These range from temperatures from 335K to 15K, with tight uniformity and controllability for maintining thermal stability and pressure control. One unique requirement for two test was structurally proof loading hardware by creating thermal gradients at specific temperatures. This paper will discuss the thermal requirements and goals of the tests, the original requirements of the chamber thermal systems for planned operation, and how the new requirements were met by the team using the hardware, system flexiblilty, and engineering creativity. It will also discuss the mistakes and successes to meet the unique goals, especially when meeting the thermal proof load.

  19. Association between thermal environment and Salmonella in fecal samples from dairy cattle in midwestern United States.

    PubMed

    Likavec, Tasha; Pires, Alda F A; Funk, Julie A

    2016-07-01

    The objective of this study was to describe the association between thermal measures in the barn environment (pen temperature and humidity) and fecal shedding of Salmonella in dairy cattle. A repeated cross-sectional study was conducted within a commercial dairy herd located in the midwestern United States. Five pooled fecal samples were collected monthly from each pen for 9 mo and submitted for microbiological culture. Negative binomial regression methods were used to test the association [incidence rate ratio (IRR)] between Salmonella pen status (the count of Salmonella-positive pools) and thermal environmental parameters [average temperature and temperature humidity index (THI)] for 3 time periods (48 h, 72 h, and 1 wk) before fecal sampling. Salmonella was cultured from 10.8% [39/360; 95% confidence interval (CI): 7.8% to 14.5%] of pooled samples. The highest proportion of positive pools occurred in August. The IRR ranged from 1.26 (95% CI: 1.15 to 1.39, THI 1 wk) to 4.5 (95% CI: 2.13 to 9.51, heat exposure 1 wk) across all thermal parameters and lag time periods measured. For example, the incidence rate of Salmonella-positive pools increased by 54% for every 5°C increment in average temperature (IRR = 1.54; 95% CI: 1.29 to 1.85) and 29% for every 5-unit increase in THI (IRR = 1.29; 95% CI: 1.16 to 1.42) during the 72 h before sampling. The incidence rate ratio for pens exposed to higher temperatures (> 25°C) was 4.5 times (95% CI: 2.13 to 9.51) the incidence rate ratio for pens exposed to temperatures < 25°C in the 72 h before sampling. Likewise, the incidence rate ratio for pens exposed to THI > 70 was 4.23 times greater (95% CI: 2.1 to 8.28) than when the THI was < 70 in the 72 h before sampling. An association was found between the thermal environment and Salmonella shedding in dairy cattle. Further research is warranted in order to fully understand the component risks associated with the summer season and increased Salmonella shedding. PMID:27408330

  20. Characteristics of the infant thermal environment in the control population of a case-control study of SIDS.

    PubMed

    Ponsonby, A L; Dwyer, T; Cochrane, J A; Gibbons, L E; Jones, M E

    1992-01-01

    This report examines the thermal environment during last sleep of a control population to investigate how the thermal environment of the infant's bedroom varies by season, external temperature and by certain maternal and infant characteristics. Two age-matched control infants were chosen for each case, one of which was also matched on birthweight. The home visits were not pre-arranged and were matched on climatic conditions, time of year and time period of day for the index case. The initial response rate for controls (n = 108) was 86%. Although there was a large amount of variation in the infant thermal environment, thermal insulation correlated with room temperature (r = -0.44, P = 0.0001) and external temperature (r = -0.30, P = 0.002). The thermal environment of the infant, as defined by excess thermal insulation for room temperature, did not vary by indoor or outdoor temperature, but higher average values were observed in teenage mothers (mean difference = 2.7 tog [95% Cl = 0.3, 5.2]), infants who slept in an adult bed (mean difference = 2.6 tog [-0.1, 5.4]) and infants with an illness (mean difference = 0.8 tog [-0.3, 1.9]). There was a tendency for the thermal environment of infants to be higher and more variable during winter, supporting previous hypotheses that paradoxical overheating may occur in some infants during winter. Further work is required to provide a set of recommendations on the optimal thermal conditions for post-neonatal infants. PMID:1524881

  1. Assessment of Human Safety and Thermal Comfort in High-Temperature Environment: CFD and Human Thermoregulation Model

    NASA Astrophysics Data System (ADS)

    Xuefeng, Han; Wenguo, Weng; Shifei, Shen

    2010-05-01

    The safety and the thermal comfort of victims and firefighters are important in the building fires, which are a little dependent on the occupant fatalities. In order to investigate the effects of the dangerous environment on human body in fires, numerical calculation of the heat transfer and human thermoregulation are presented in this paper. The numerical manikins coupled with human thermal models were proved as powerful tools for visualizing thermal comfort. The two-node model by Gagge and multi-code thermoregulation models were investigated, and the Gagge's model was coupled with the CFD for high-temperature environment simulation, with which a numerical manikin was built. During the simulation, temperatures of skin and core compartment of Computer Simulated Person (CPS) were recorded respectively, and the Predicted Mean Vote index values were counted. The thermal load on skin is much higher than neutral cases and the skin can be burnt in minutes if no protection and heat abstraction methods were introduced. Though existing models can predict thermal comfort in general indoor environment, they are not suitable in predicting the thermal comfort with high-temperature cases. It was suggested that more research combining CFD coupling thermoregulation models with thermal manikin experiment are needed.

  2. Structure and composition of phases occurring in austenitic stainless steels in thermal and irradiation environments

    SciTech Connect

    Lee, E.H.; Maziasz, P.J.; Rowcliffe, A.F.

    1980-01-01

    Transmission electron diffraction techniques coupled with quantitative x-ray energy dispersive spectroscopy have been used to characterize the phases which develop in austenitic stainless steels during exposure to thermal and to irradiation environments. In AISI 316 and Ti-modified stainless steels some thirteen phases have been identified and characterized in terms of their crystal structure and chemical composition. Irradiation does not produce any completely new phases. However, as a result of radiation-induced segregation principally of Ni and Si, and of enhanced diffusion rates, several major changes in phase relationships occur during irradiation. Firstly, phases characteristic of remote regions of the phase diagram appear unexpectedly and dissolve during postirradiation annealing (radiation-induced phases). Secondly, some phases develop with their compositions significantly altered by the incorporation of Ni or Si (radiation-modified phases).

  3. The definition of the low earth orbital environment and its effect on thermal control materials

    NASA Technical Reports Server (NTRS)

    Durcanin, J. T.; Chalmers, D. R.; Visentine, J. T.

    1987-01-01

    The LEO environment and its effects on thermal-control materials (TCMs) being evaluated for use in long-term-mission space structures such as the Space Station are characterized, summarizing the results of recent space and laboratory experiments. Factors examined include atomic oxygen (a serious problem out to 600-700 km), ionizing radiation, solar UV radiation, solid particles (manmade debris and micrometeoroids, a significant hazard out to about 1000 km), and synergistic effects. Numerical data on the expected intensity of these effects for the different Space Station components, the resistance of specific TCMs to the effects, and the effectiveness of protective coatings are compiled in extensive tables and illustrated with diagrams, graphs, and micrographs.

  4. Numerical Study of Flow Augmented Thermal Management for Entry and Re-Entry Environments

    NASA Technical Reports Server (NTRS)

    Cheng, Gary C.; Neroorkar, Kshitij D.; Chen, Yen-Sen; Wang, Ten-See; Daso, Endwell O.

    2007-01-01

    The use of a flow augmented thermal management system for entry and re-entr environments is one method for reducing heat and drag loads. This concept relies on jet penetration from supersonic and hypersonic counterflowing jets that could significantly weaken and disperse the shock-wave system of the spacecraft flow field. The objective of this research effort is to conduct parametric studies of the supersonic flow over a 2.6% scale model of the Apollo capsule, with and without the counterflowing jet, using time-accurate and steady-state computational fluid dynamics simulations. The numerical studies, including different freestream Mach number angle of attack counterflowing jet mass flow rate, and nozzle configurations, were performed to examine their effect on the drag and beat loads and to explore the counternowing jet condition. The numerical results were compared with the test data obtained from transonic blow-down wind-tunnel experiments conducted independently at NASA MSFC.

  5. Galileo probe forebody entry thermal protection - Aerothermal environments and heat shielding requirements

    NASA Technical Reports Server (NTRS)

    Nicolet, W. E.; Davy, W. C.; Wilson, J. F.

    1980-01-01

    Solutions are presented for the aerothermal heating environments and the material thermal response for the forebody heatshield on the candidate 242 kg Galileo probe entering the modeled nominal and cold-dense Jovian atmospheres. In the flowfield analysis, a finite difference procedure was employed to obtain benchmark predictions of pressure, radiation and convective heating rates (both laminar and turbulent) and the corresponding wall blowing obtained under the steady state approximation. The fluxes over the probe flank were found to be in a range where spallation is an important mass loss mechanism. The predicted heating rates were also used as boundary conditions for a charring materials ablation which was used to predict thermochemical based surface recession, mass loss and bondline temperatures. The contingency factor of 30% currently employed by NASA was found to be insufficient for entry into the cold-dense atmosphere.

  6. [Analysis of urban thermal environment change characteristics during the total solar eclipse].

    PubMed

    Lu, Jun; Chen, Shi-Ling; Bu, Cui-Wen; Liu, Yu-Xi

    2011-04-01

    There was a very good observation area in Chongqing for the total solar eclipse along the Changjiang river on 22 July, 2009. Through the experiments, the outdoor meteorological data (solar radiation, air temperature and relative humidity) were observed and recorded on 21 July and 22 July. Based on the experimental observation data, the effect of thermal environment in Chongqing area was to analyzed and discussed. Experiment indicates that the reduction of air temperature and surface temperature resulted in the decrease in the solar radiation intensity, and the amplitude of the air temperature change is 2.4 degrees C during the total solar eclipse. Compared with the two days' air temperature, the amplitude of the air temperature change reached 4.6 degrees C on account of the total solar eclipse. PMID:21714227

  7. Utilization fo the Satellite Test Assistant Robot (STAR) for Visual and Thermal Analysis for Articles in the Thermal Vacuum Test Environment

    NASA Technical Reports Server (NTRS)

    Johnson, K.; Siebes, G.; McAffee, D.

    1996-01-01

    An innovative new telerobotic inspection system called STAR has been developed to asist engineers in the visual and thermal analysis fo flight hardware being tested in a simulated space environment. This paper describes the architecture of the STAR mechanical and control systems and discusses some uses of STAR to date.

  8. Investigation of Primary Dew-Point Saturator Efficiency in Two Different Thermal Environments

    NASA Astrophysics Data System (ADS)

    Zvizdic, D.; Heinonen, M.; Sestan, D.

    2015-08-01

    The aim of this paper is to describe the evaluation process of the performance of the low-range saturator (LRS), when exposed to two different thermal environments. The examined saturator was designed, built, and tested at MIKES (Centre for Metrology and Accreditation, Finland), and then transported to the Laboratory for Process Measurement (LPM) in Croatia, where it was implemented in a new dew-point calibration system. The saturator works on a single-pressure-single-pass generation principle in the dew/frost-point temperature range between and . The purpose of the various tests performed at MIKES was to examine the efficiency and non-ideality of the saturator. As a test bath facility in Croatia differs from the one used in Finland, the same tests were repeated at LPM, and the effects of different thermal conditions on saturator performance were examined. Thermometers, pressure gauges, an air preparation system, and water for filling the saturator at LPM were also different than those used at MIKES. Results obtained by both laboratories indicate that the efficiency of the examined saturator was not affected either by the thermal conditions under which it was tested or by equipment used for the tests. Both laboratories concluded that LRS is efficient enough for a primary realization of the dew/frost-point temperature scale in the range from to , with flow rates between and . It is also shown that a considerable difference of the pre-saturator efficiency, indicated by two laboratories, did not have influence to the overall performance of the saturator. The results of the research are presented in graphical and tabular forms. This paper also gives a brief description of the design and operation principle of the investigated low-range saturator.

  9. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    NASA Technical Reports Server (NTRS)

    Ellerby, Donald; Venkatapathy, Ethiraj; Stackpoole, Margaret; Chinnapongse, Ronald; Munk, Michelle; Dillman, Robert; Feldman, Jay; Prabhu, Dinesh; Beerman, Adam

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-shield for extreme entry environment.

  10. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    NASA Technical Reports Server (NTRS)

    Chinnapongse, Ronald; Ellerbe, Donald; Stackpoole, Maragaret; Venkatapathy, Ethiraj; Beerman, Adam; Feldman, Jay; Peterson Keith; Prabhu, Dinesh; Dillman, Robert; Munk, Michelle

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely severe entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-­-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-­-shield for extreme entry environment.

  11. Molecular adaptation to an extreme environment: origin of the thermal stability of the pompeii worm collagen.

    PubMed

    Sicot, F X; Mesnage, M; Masselot, M; Exposito, J Y; Garrone, R; Deutsch, J; Gaill, F

    2000-09-29

    The annelid Alvinella pompejana is probably the most heat-tolerant metazoan organism known. Previous results have shown that the level of thermal stability of its interstitial collagen is significantly greater than that of coastal annelids and of vent organisms, such as the vestimentiferan Riftia pachyptila, living in colder parts of the deep-sea hydrothermal environment. In order to investigate the molecular basis of this thermal behavior, we cloned and sequenced a large cDNA molecule coding the fibrillar collagen of Alvinella, including one half of the helical domain and the entire C-propeptide domain. For comparison, we also cloned the 3' part of the homologous cDNA from Riftia. Comparison of the corresponding helical domains of these two species, together with that of the previously sequenced domain of the coastal lugworm Arenicola marina, showed that the increase in proline content and in the number of stabilizing triplets correlate with the outstanding thermostability of the interstitial collagen of A. pompejana. Phylogenetic analysis showed that triple helical and the C-propeptide parts of the same collagen molecule evolve at different rates, in favor of an adaptive mechanism at the molecular level. PMID:10993725

  12. Influence of thermal environment on optimal working conditions of thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Apertet, Y.; Ouerdane, H.; Goupil, C.; Lecoeur, Ph.

    2014-10-01

    Optimization analysis of thermoelectric generators operation is of importance both for practical applications and theoretical considerations. Depending on the desired goal, two different strategies are possible to achieve high performance: through optimization one may seek either power output maximization or conversion efficiency maximization. Recent literature reveals the persistent flawed notion that these two optimal working conditions may be achieved simultaneously. In this article, we lift all source of confusion by correctly posing the problem and solving it. We assume and discuss two possibilities for the environment of the generator to govern its operation: constant incoming heat flux, and constant temperature difference between the heat reservoirs. We demonstrate that, while power and efficiency are maximized simultaneously if the first assumption is considered, this is not possible with the second assumption. This latter corresponds to the seminal analyses of Ioffe who put forth and stressed the importance of the thermoelectric figure of merit ZT. We also provide a simple procedure to determine the different optimal design parameters of a thermoelectric generator connected to heat reservoirs through thermal contacts with a finite and fixed thermal conductance.

  13. Performance of Thermal Mass Flow Meters in a Variable Gravitational Environment

    NASA Technical Reports Server (NTRS)

    Brooker, John E.; Ruff, Gary A.

    2004-01-01

    The performance of five thermal mass flow meters, MKS Instruments 179A and 258C, Unit Instruments UFM-8100, Sierra Instruments 830L, and Hastings Instruments HFM-200, were tested on the KC-135 Reduced Gravity Aircraft in orthogonal, coparallel, and counterparallel orientations relative to gravity. Data was taken throughout the parabolic trajectory where the g-level varied from 0.01 to 1.8 times normal gravity. Each meter was calibrated in normal gravity in the orthogonal position prior to flight followed by ground testing at seven different flow conditions to establish a baseline operation. During the tests, the actual flow rate was measured independently using choked-flow orifices. Gravitational acceleration and attitude had a unique effect on the performance of each meter. All meters operated within acceptable limits at all gravity levels in the calibrated orthogonal position. However, when operated in other orientations, the deviations from the reference flow became substantial for several of the flow meters. Data analysis indicated that the greatest source of error was the effect of orientation, followed by the gravity level. This work emphasized that when operating thermal flow meters in a variable gravity environment, it is critical to orient the meter in the same direction relative to gravity in which it was calibrated. Unfortunately, there was no test in normal gravity that could predict the performance of a meter in reduced gravity. When operating in reduced gravity, all meters indicated within 5 percent of the full scale reading at all flow conditions and orientations.

  14. LONG-TERM EFFECTS OF ADVERSE ENVIRONMENTS DURING DEVELOPMENT: EFFECTS ON ADULTHOOD IN RATS EXPOSED TO TOXICANTS OR UNDERNUTRITION IN UTERO.

    EPA Science Inventory

    Studies have shown correlations between in utero and early life environments and diseases later in life, including hypertension, coronary heart disease, diabetes, obesity, schizophrenia, early onset chronic renal failure, cancer and compromised repro-duction. Current development...

  15. Reconstruction of the thermal environment evolution from subsurface temperature distribution in large cities in East Asia

    NASA Astrophysics Data System (ADS)

    Hamamoto, H.; Goto, S.; Vuthy, M.; Nishijima, J.; Yamano, M.; Taniguchi, M.; Miyakoshi, A.; Hachinohe, S.; Sasaka, K.; Shiraishi, H.

    2009-12-01

    Temperature changes at the ground surface propagate into the underground and disturb the subsurface temperature structure. Analyzing disturbances in the subsurface temperature structure, we can reconstruct the past ground surface temperature (GST) change, which is closely related to the past surface air temperature change. This method can be applied to studies of thermal environment evolution in urban areas such as the development of “heat islands”. As part of an international multidisciplinary research project “Human Impacts on Urban Subsurface Environments”, we have been investigating GST histories in and around several large cities in East Asia, including Bangkok and Tokyo. We have also started a study on the subsurface thermal environment in Saitama prefecture, located on the north of Tokyo, as a research project of CESS (Center for Environmental Science in Saitama). The eastern part of Saitama prefecture is densely populated and considered to be a part of Tokyo Metropolitan area. In this presentation, we show the results of GST history reconstruction in the both areas. In Bangkok area, we conducted measurements of temperature profiles in groundwater monitoring wells at 45 sites in 2004, 2006, and 2008. In Saitama, we measured temperature profiles at 15 sites in 2009. We examined the shapes of the temperature profiles and selected ones that are not significantly disturbed by groundwater flow. Reconstruction of GST history for the last several hundred years was made at six sites in the Bangkok area and at two sites in the Saitama area. We used a multi-layer model that allows layers with different thermal properties, determining layer boundaries based on lithology of the formations around the wells. All of the reconstructed GST histories show surface warming in the last century. In the Bangkok area, the amount of the temperature increase ranges from 0.4 to 2.6 K and is larger in the city than in the area to the west of Bangkok and in the northern rural

  16. Courtship Song Does Not Increase the Rate of Adaptation to a Thermally Stressful Environment in a Drosophila melanogaster Laboratory Population

    PubMed Central

    Cabral, Larry G.; Holland, Brett

    2014-01-01

    Courtship song in D. melanogaster contributes substantially to male mating success through female selection. We used experimental evolution to test whether this display trait is maintained through adaptive female selection because it indicates heritable male quality for thermal stress tolerance. We used non-displaying, outbred populations of D. melanogaster (nub1) mutants and measured their rate of adaptation to a new, thermally stressful environment, relative to wild-type control populations that retained courtship song. This design retains sexually selected conflict in both treatments. Thermal stress should select across genomes for newly beneficial alleles, increasing the available genetic and phenotypic variation and, therefore, the magnitude of female benefit derived from courtship song. Following introduction to the thermally stressful environment, net reproductive rate decreased 50% over four generations, and then increased 19% over the following 16 generations. There were no differences between the treatments. Possible explanations for these results are discussed. PMID:25365209

  17. Infiltration Route Analysis Using Thermal Observation Devices (TOD) and Optimization Techniques in a GIS Environment

    PubMed Central

    Bang, Soonam; Heo, Joon; Han, Soohee; Sohn, Hong-Gyoo

    2010-01-01

    Infiltration-route analysis is a military application of geospatial information system (GIS) technology. In order to find susceptible routes, optimal-path-searching algorithms are applied to minimize the cost function, which is the summed result of detection probability. The cost function was determined according to the thermal observation device (TOD) detection probability, the viewshed analysis results, and two feature layers extracted from the vector product interim terrain data. The detection probability is computed and recorded for an individual cell (50 m × 50 m), and the optimal infiltration routes are determined with A* algorithm by minimizing the summed costs on the routes from a start point to an end point. In the present study, in order to simulate the dynamic nature of a real-world problem, one thousand cost surfaces in the GIS environment were generated with randomly located TODs and randomly selected infiltration start points. Accordingly, one thousand sets of vulnerable routes for infiltration purposes could be found, which could be accumulated and presented as an infiltration vulnerability map. This application can be further utilized for both optimal infiltration routing and surveillance network design. Indeed, dynamic simulation in the GIS environment is considered to be a powerful and practical solution for optimization problems. A similar approach can be applied to the dynamic optimal routing for civil infrastructure, which requires consideration of terrain-related constraints and cost functions. PMID:22315544

  18. The effect of safety hat on thermal responses and working efficiency under a high temperature environment.

    PubMed

    Kim, Hee-Eun; Park, So-Jin

    2004-09-01

    The purpose of this study is to examine the effect of a safety hat on thermal responses and work efficiency under a high temperature environment. Five healthy male subjects participated in the repeated 'Rest' and 'Exercise' periods in order to compare a safety hat without holes (annoted as 'without hole') and a safety hat with holes (annoted as 'with hole') in a climatic chamber of 30 degrees C, 50%RH. The main findings are as follows: (a) the core temperature (tympanic temperature) and heart rate showed significantly lower levels in the subjects who are under the 'with hole' condition than those who are under the 'without hole' condition; (b) the forehead skin temperature was significantly higher in the subjects who are under the 'without hole' condition than those who ar uder the 'with hole' condition; (c) blood pressure was significantly lower in the 'with hole' condition; and (d) sweat rate which was measured by weight loss before and after the experiment was higher in the 'without hole' condition; and (e) work ability which was measured by a grip strength dynamometer was higher in the 'with hole' condition. Making a hole in the safety hat, designed for proper ventilation and hygiene, is practical in letting out heat and decreasing the physiological burden under a hot working environment. The safety hat with holes is useful in maintaining the homeostasis of the body temperature by releasing body heat efficiently and it is meaningful to keep the working efficiency. PMID:15472459

  19. Heart rate in Palaemon northropi (Rankin) in relation to acute changes in thermal environment

    SciTech Connect

    Swanson, C.J.; Wingard, C.; Kitakis, F. )

    1991-03-15

    The Glass Shrimp (Palaemon northropi), common to shallow water/tide pool environs of Atlantic waters, was examined in a series of experiments whereby the temperature-dependence of steady-state heart rate was assessed after acute, controlled changed in their thermal environment. Collection site, tide pool variations averaged 17.2-31.6C/24 hr. period. Accordingly, steady-state heart rates were determined at 5, 15, 25, and 30C by using both timed, optical recording and impedance methods. Mean values obtained were 88bpm (5C), 181 bpm(15C), 236bpm(25C), and 52bpm(30C). Calculated Q{sub 10} determinations ranged from the limits of 1.3 to 2.1 excluding the highest temperature state used. Specimens used averaged 0.62gm wet body weight, and no significant difference between males and gravid females was found. Additionally, the impedance method employed allowed for more precise rate determinations at high heart rates: at the lower heart rates, there was no difference between optically-timed vs. impedance method. Measurement at 30C characteristically showed a severe depression of heart rate, and high mortality after determinations. It is concluded that in situ field survival of Palaemon northropi may involve a time-dependence and/or other mechanisms whereby upper environmental temperatures may be abated.

  20. Toward quantitative aerial thermal infrared thermography for energy conservation in the built environment

    NASA Astrophysics Data System (ADS)

    Allinson, David; Medjdoub, Benachir; Wilson, Robin

    2005-03-01

    The UK Home Energy Conservation Act puts a duty on local authorities to develop strategies to improve energy efficiency in all public and private sector housing in order to tackle fuel poverty and reduce carbon dioxide emissions. The City of Nottingham, UK turned to aerial Thermal InfraRed Thermography (TIRT) to try and identify households where energy savings can be made. In this paper, existing literature is reviewed to explain the limitations of aerial TIRT for energy conservation in the built environment and define the techniques required to overcome them. This includes the range of suitable meteorological conditions at the time of the survey, the use of ground truth data, the need to account for all radiation paths and losses when calculating roof surface temperature and the assumptions that must be made when calculating insulation levels. Atmospheric calibration, roof surface emissivity and sky view factor must also be determined by some means and approaches to these problems are reviewed from the wider literature. Error analysis and benchmarking are important if the technique is to be validated and these are discussed with reference to the literature. A methodology for determining the thickness of loft insulation for residential buildings in the city of Nottingham, UK using aerial TIRT data within a GIS software environment is proposed.

  1. A comparison of methods for total community DNA preservation and extraction from various thermal environments.

    PubMed

    Mitchell, Kendra R; Takacs-Vesbach, Cristina D

    2008-10-01

    The widespread use of molecular techniques in studying microbial communities has greatly enhanced our understanding of microbial diversity and function in the natural environment and contributed to an explosion of novel commercially viable enzymes. One of the most promising environments for detecting novel processes, enzymes, and microbial diversity is hot springs. We examined potential biases introduced by DNA preservation and extraction methods by comparing the quality, quantity, and diversity of environmental DNA samples preserved and extracted by commonly used methods. We included samples from sites representing the spectrum of environmental conditions that are found in Yellowstone National Park thermal features. Samples preserved in a non-toxic sucrose lysis buffer (SLB), along with a variation of a standard DNA extraction method using CTAB resulted in higher quality and quantity DNA than the other preservation and extraction methods tested here. Richness determined using DGGE revealed that there was some variation within replicates of a sample, but no statistical difference among the methods. However, the sucrose lysis buffer preserved samples extracted by the CTAB method were 15-43% more diverse than the other treatments. PMID:18633656

  2. Characteristics of Trailer Thermal Environment during Commercial Swine Transport Managed under U.S. Industry Guidelines.

    PubMed

    Xiong, Yijie; Green, Angela; Gates, Richard S

    2015-01-01

    Transport is a critical factor in modern pork production and can seriously affect swine welfare. While previous research has explored thermal conditions during transport, the impact of extreme weather conditions on the trailer thermal environment under industry practices has not been well documented; and the critical factors impacting microclimate are not well understood. To assess the trailer microclimate during transport events, an instrumentation system was designed and installed at the central ceiling level, pig level and floor-level in each of six zones inside a commercial swine trailer. Transport environmental data from 34 monitoring trips (approximately 1-4 h in duration each) were collected from May, 2012, to February, 2013, with trailer management corresponding to the National Pork Board Transport Quality Assurance (TQA) guidelines in 31 of these trips. According to the TQA guidelines, for outdoor temperature ranging from 5 °C (40 °F) to 27 °C (80 °F), acceptable thermal conditions were observed based on the criteria that no more than 10% of the trip duration was above 35 °C (95 °F) or below 0 °C (32 °F). Recommended bedding, boarding and water application were sufficient in this range. Measurements support relaxing boarding guidelines for moderate outdoor conditions, as this did not result in less desirable conditions. Pigs experienced extended undesirable thermal conditions for outdoor temperatures above 27 °C (80 °F) or below 5 °C (40 °F), meriting a recommendation for further assessment of bedding, boarding and water application guidelines for extreme outdoor temperatures. An Emergency Livestock Weather Safety Index (LWSI) condition was observed inside the trailer when outdoor temperature exceeded 10 °C (50 °F); although the validity of LWSI to indicate heat stress for pigs during transport is not well established. Extreme pig surface temperatures in the rear and middle zones of the trailer were more frequently experienced than in the

  3. Effect of thermal environment and caloric intake on head growth of low birthweight infants during late neonatal period.

    PubMed Central

    Glass, L; Lala, R V; Jaiswal, V; Nigam, S K

    1975-01-01

    In order to assess the effects of ambient thermal conditions on postnatal head growth in low birth weight infants, 42 asymtomatic neonates were reared under 4 combinations of caloric intake and thermal environment after the first week of life. Exposure to a subthermoneutral temperature (abdominal skin temperature of 35 degrees C), together with a relatively low caloric intake (120 cal/kg per day), was associated with significant retardation of head growth over a 2-week study period. PMID:1167073

  4. Characteristics of Trailer Thermal Environment during Commercial Swine Transport Managed under U.S. Industry Guidelines

    PubMed Central

    Xiong, Yijie; Green, Angela; Gates, Richard S.

    2015-01-01

    Simple Summary Temperature and thermal conditions of the interior of a swine trailer during transport were monitored over a broad range of outdoor conditions (34 trips total) managed according to industry best practice (Transport Quality Assurance (TQA) guidelines (NPB, 2008)). For the outdoor temperature range of 5 °C (40 °F) to 27 °C (80 °F), generally acceptable trailer thermal conditions were observed according to the TQA. Beyond this outdoor temperature range, undesirable conditions within the trailer were prevalent. Areas for potential improvement in transport management were identified. Stops resulted in rapid increases in temperature, which could be beneficial during cooler outdoor temperatures, but detrimental for warmer outdoor temperatures. Abstract Transport is a critical factor in modern pork production and can seriously affect swine welfare. While previous research has explored thermal conditions during transport, the impact of extreme weather conditions on the trailer thermal environment under industry practices has not been well documented; and the critical factors impacting microclimate are not well understood. To assess the trailer microclimate during transport events, an instrumentation system was designed and installed at the central ceiling level, pig level and floor-level in each of six zones inside a commercial swine trailer. Transport environmental data from 34 monitoring trips (approximately 1–4 h in duration each) were collected from May, 2012, to February, 2013, with trailer management corresponding to the National Pork Board Transport Quality Assurance (TQA) guidelines in 31 of these trips. According to the TQA guidelines, for outdoor temperature ranging from 5 °C (40 °F) to 27 °C (80 °F), acceptable thermal conditions were observed based on the criteria that no more than 10% of the trip duration was above 35 °C (95 °F) or below 0 °C (32 °F). Recommended bedding, boarding and water application were sufficient in this range

  5. Vaccine Adverse Events

    MedlinePlus

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Vaccines, Blood & Biologics Home Vaccines, Blood & Biologics Safety & Availability ( ... Center for Biologics Evaluation & Research Vaccine Adverse Events Vaccine Adverse Events Share Tweet Linkedin Pin it More ...

  6. Nutritional and environmental studies on an ocean-going oil tanker. 1. Thermal environment

    PubMed Central

    Collins, K. J.; Eddy, T. P.; Lee, D. E.; Swann, P. G.

    1971-01-01

    Collins, K. J., Eddy, T. P., Lee, D. E., and Swann, P. G. (1971).Brit. J. industr. Med.,28, 237-245. Nutritional and environmental studies on an ocean-going oil tanker. I. Thermal environment. Investigations were made on board a modern, air-conditioned oil tanker (S.S. Esso Newcastle) en route to the Persian Gulf in July to August 1967 in order to study thermal conditions in the working environment, and the nutritional status of the crew, and to examine the interrelationship between climate and nutritional balance. In this introductory paper an account is given of the aims and design of the experiments together with details of the environmental survey. The voyage round Africa lasted one month, with high ambient temperatures of 37·7°C dry bulb, 30·8°C wet bulb (100/87°F) occurring only on the last few days into and out of the Persian Gulf. Mean accommodation temperature was maintained in the zone of comfort throughout, and at 23·9°C (75°F) Corrected Effective Temperature (CET) in the Gulf. On a previous voyage in a tanker without air-conditioning CETs up to 31·6°C (89°F) had been recorded in the accommodation in the same ambient conditions. With exposure to high solar radiation in the Gulf, the deck officer's cabins and bridge house in the upper superstructure became uncomfortably warm (CET exceeding 26·6°C (80°F)) and in these temperatures skilled performance is likely to deteriorate. The main thermal problems in the working environment were associated with the engine and boiler rooms which were consistently 11 to 17°C (20 to 30°F) higher than ambient temperature. For personnel on watch, the levels of heat stress were high but not intolerable if advantage was taken of the air blowers. Conditions under which emergency or repair tasks were carried out in very hot engine-room spaces were examined and often found to allow only a small margin of safety. Predicted average tolerance times were deduced from the Wet Bulb Globe Temperature (WBGT) scale of

  7. Hydrogeochemistry of thermal springs in saline salar-like environments in the High Andes

    NASA Astrophysics Data System (ADS)

    Lagos Durán, L. V.; Reich, M.; Achurra, L.; Morata, D.

    2014-12-01

    Evaporitic deposits and precipitates represent significant sinks of mobile cations (Li, As, B) and halides (Cl, I) in salar-like basin environments along the Andean volcanic belt in northern Chile. Li and B are particularly interesting because of their high concentrations in evaporitic minerals and geothermal waters in the region. Although these compositional features have been previously recognized in high-altitude salt lakes in northern Chile, the nature and extent of mixing processes between true evaporitic and geothermal endmembers in such environments is poorly understood. In a context where geothermal targeting methods need to be increasingly precise, a clearer understanding of what controls the localization of concealed geothermal resources is a prerequisite for more efficient exploration. Therefore, it is necessary to constrain surface saline inputs that can mask the deep imprints of the geothermal reservoir. On this basis, northern Chile offers a unique opportunity to test these features due to the large number of evaporitic closed basins containing thermal springs. To date, only a very limited number of studies have reported trace element concentrations and B, Li and Sr isotopes in salar-like waters aimed at differentiating the relative contributions of both members. In this study, we sampled water from high-altitude lakes with and without surficial thermal activity. This was complemented with geothermal water analyses from northern Chile and previously published data. In addition, we report preliminary dissolution experiments of evaporite minerals (e.g. ulexite, halite, gypsum, aragonite) to pure distilled water. These minerals were taken from two selected hydrological domains, located in the southern and northern part of the Chilean Central Volcanic Zone. Geochemical analyses of water run products from the aforementioned experiments at different temperatures (25 and 87°C, 500 hours of interaction each), confirmed that selected common elements (Cl, Li

  8. Thermal environment downscaling under the climate chenage in Seto-Inland Sea of Japan

    NASA Astrophysics Data System (ADS)

    Imai, Y.; Mori, N.; Ninomiya, J.; Yasuda, T.; Mase, H.

    2015-12-01

    Introduction There are many studies have been conducted to project future change and assess the impacts. The latest IPCC AR5 WGI reports that there are many impact assessments of large scale changes in coastal and ocean environments but few studies on regional scale changes. We analyzed global and regional near-sea surface physical changes based on the Coupled Model Intercomparison Project Phase 5 (CMIP5) data. The downscaling of regional ocean targeting the semi-enclosed Seto-Inland Sea of Japan by Regional Ocean Modeling System (ROMS) considering the results of CMIP5. We analyzed the future projection of thermal environmental changes of the Seto-Inland Sea based on the downscaling results. Regional analysis of CMIP5 Analysis of CMIP5 was conducted for the historical climate and future climate at the end of 21st century considering two different emission scenarios (RCP4.5 and RCP8.5). All available 61 GCMs in CMIP5 were considered for analysis and the future changes of 11 atmospheric and oceanic variables were computed in detail. Spatial distribution of sea surface temperature (SST) showed a consistent increase overall, with local non-homogeneity. For example, an increase SST more than 4 degrees in the Northwest Pacific against to global mean SST increase of 2.6 degrees. The projection of the Seto-Inland Sea environment Dynamical downscaling for Seto-Inland Sea was calculated for the year 2093 forcing future changes from CMIP5 analysis results to project future regional environmental changes in West-Japan. The results of hindcast were compared with observed results and future climate conditions were added to hindcast results. The SST shows a remarkable increase of about 3.6 degrees in the summer but it is less in the future winter. The major change of water temperature change is increasing trend in upper 20m layer, and thermal e-folding depth in the future climate becomes shallower. The warming tendency decreases with depth in shallow water region but is different

  9. Thermal response of rigid and flexible insulations and reflective coating in an aeroconvective heating environment

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Chiu, S. A.; Iverson, D. J.; Lowe, D. M.

    1992-01-01

    Described here is the thermal performance of rigid and flexible thermal protection systems considered for potential use in future Aeroassist Space Transfer Vehicles. The thermal response of these materials subjected to aeroconvective heating from a plasma arc is described. Properties that were measured included the thermal conductivity of both rigid and flexible insulations at various temperatures and pressures and the emissivity of the fabrics used in the flexible insulations. The results from computerized thermal analysis models describing the thermal response of these materials subjected to flight conditions are included.

  10. Construction of a Thermal Vacuum Chamber for Environment Test of Triple CubeSat Mission TRIO-CINEMA

    NASA Astrophysics Data System (ADS)

    Jeon, Jeheon; Lee, Seongwhan; Yoon, Seyoung; Seon, Jongho; Jin, Ho; Lee, Donghun; Lin, Robert P.

    2013-12-01

    TRiplet Ionospheric Observatory-CubeSat for Ion, Neutron, Electron & MAgnetic fields (TRIO-CINEMA) is a CubeSat with 3.14 kg in weight and 3-U (10 × 10 × 30 cm) in size, jointly developed by Kyung Hee University and UC Berkeley to measure magnetic fields of near Earth space and detect plasma particles. When a satellite is launched into orbit, it encounters ultrahigh vacuum and extreme temperature. To verify the operation and survivability of the satellite in such an extreme space environment, experimental tests are conducted on the ground using thermal vacuum chamber. This paper describes the temperature control device and monitoring system suitable for CubeSat test environment using the thermal vacuum chamber of the School of Space Research, Kyung Hee University. To build the chamber, we use a general purpose thermal analysis program and NX 6.0 TMG program. We carry out thermal vacuum tests on the two flight models developed by Kyung Hee University based on the thermal model of the TRIO-CINEMA satellite. It is expected from this experiment that proper operation of the satellite in the space environment will be achieved.

  11. Evaluation of reformulated thermal control coatings in a simulated space environment. Part 1: YB-71

    NASA Technical Reports Server (NTRS)

    Cerbus, Clifford A.; Carlin, Patrick S.

    1994-01-01

    The Air Force Space and Missile Systems Center and Wright Laboratory Materials Directorate (WL/ML) have sponsored and effort to effort to reformulate and qualify Illinois Institute of Technology Research Institute (IITRI) spacecraft thermal control coatings. S13G/LO-1, Z93, and YB-71 coatings were reformulated because the potassium silicate binder, Sylvania PS-7, used in the coatings is no longer manufactured. Coatings utilizing the binder's replacement candidate, Kasil 2130, manufactured by The Philadelphia Quartz (PQ) Corporation, Baltimore, Maryland, and undergoing testing at the Materials Directorate's Space Combined Effects Primary Test and Research Equipment (SCEPTRE) Facility operated by the University of Dayton Research Institute (UDRI). The simulated space environment consists of combined ultraviolet (UV) and electron exposure with in site specimen reflectance measurements. A brief description of the effort at IITRI, results and discussion from testing the reformulated YB-71 coating in SCEPTRE, and plans for further testing of reformulated Z93 and S13G/LO-1 are presented.

  12. Tent caterpillars are robust to variation in leaf phenology and quality in two thermal environments.

    PubMed

    Sarfraz, Rana M; Kharouba, Heather M; Myers, Judith H

    2013-10-01

    The synchrony between emergence of spring-active, insect herbivores and the budburst of their host plants could be affected by warming temperatures with influences on the availability and quality of foliage as it undergoes physical and chemical changes. This can affect the growth and survival of insects. Here, we used sun-exposed and shaded trees to determine whether the synchrony between egg hatch of western tent caterpillar, Malacosoma californicum pluviale Dyar (Lepidoptera:Lasiocampidae) and budburst of its host red alder, Alnus rubra Bongard (Betulaceae)changes with different thermal environments (temperature and light together). To explore the potential outcome of a shift in phenological synchrony, we used laboratory assays of larval growth and survival to determine the effect of variation in young, youthful and mature leaves from sun-exposed and shaded trees. While the average higher temperature of sun-exposed trees advanced the timing of budburst and egg hatch, synchrony was not disrupted. Leaf quality had no significant influence on growth or survival in the laboratory for early instars reared as family groups. Later instar larvae, however, performed best on mature leaves from sun-exposed trees. The robust relationship between leaf and larval development of western tent caterpillars suggests that warming climates may not have a strong negative impact on their success through shifts in phenological synchrony, but might influence other aspects of leaf quality and larval condition. PMID:23464617

  13. [Spatial-temporal evolution of urban thermal environment based on spatial statistical features].

    PubMed

    Zhang, Wei; Jiang, Jin-gang; Zhu, Yu-bi

    2015-06-01

    A new method which aims to determine the area of urban heat island (UHI) was proposed in this paper based on spatial statistical features by means of remote sensing and GIS spatial analysis tools, and was applied in the spatial-temporal evolution analysis of UHI in Hangzhou, China. The results showed that the area of UHI in Hangzhou increased 8.66 times from 1984 to 2010. During the 26 years, the spatial structure of UHI in Hangzhou had become more and more complex, and its spatial distribution changed from single-center to multi-center. Generally speaking, the change trend of thermal environment in Hangzhou was turning from low-temperature spatial equilibrium to high-temperature spatial equilibrium. The major cause for the development of UHI in Hangzhou was urban expansion as it showed in the results of dynamic change detection. This new method considered the spatial correlation of urban land surface temperature (LST), and reflected the global statistical features of LST. It was more objective and accurate than the conventional methods, and could provide more information, which would help us to resolve the problem of being lack of generality and comparability in the current research. PMID:26572040

  14. Size-dependent nonlinear vibration and instability of embedded fluid-conveying SWBNNTs in thermal environment

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Norouzzadeh, A.; Gholami, R.; Faghih Shojaei, M.; Hosseinzadeh, M.

    2014-07-01

    The size-dependent nonlinear free vibration and instability of fluid-conveying single-walled boron nitride nanotubes (SWBNNTs) embedded in thermal environment are studied in this paper. The fluid-conveying SWBNNT is modeled as a Timoshenko beam by which the effects of transverse shear deformation and rotary inertia is taken into consideration. The modified strain gradient theory is used to capture the size effect. To consider the nonlinear effect, the geometric nonlinearity, based on von Kármán's assumption is introduced to develop the nonlinear governing equations of motion. By employing Hamilton's principle, the governing equations and associated boundary conditions are derived. Thereafter, a numerical solution procedure based on the generalized differential quadrature (GDQ) is introduced, according to which the nonlinear governing equations and the corresponding boundary conditions are discretized via the operational matrix of differentiation. The discretized equations are then solved analytically through the harmonic balance approach. Effects of different parameters including material length scale parameter, spring and damping constants of surrounding viscoelastic medium, and flow velocity on the nonlinear free vibration and instability of SWBNNTs are examined.

  15. Thermal environment around the Space Shuttle with hot-gas jets for ice suppression

    NASA Technical Reports Server (NTRS)

    Singhal, A. K.; Tam, L. T.; Bachtel, F.; Vaniman, J.

    1986-01-01

    To prevent prelaunch ice formation on the external tank of the Space Shuttle, the final selected approach is to heat the surrounding air with vertical hot-gas jets located at the launch pad. This approach was considerably more cost-effective than other ice suppression methods considered, although its feasibility was not easily discernible due to the complex flowfield interactions. This paper describes how the use of vertical jets was first evaluated with the aid of a computational fluid dynamics (CFD) technique. An existing general-purpose CFD program (PHOENICS) was used to predict the thermal environment around the Shuttle under various jet configurations and wind conditions. The program accounts for effects of buoyancy, turbulence, and structural obstructions in the flowfield. The computed results showed physically plausible and consistent trends. The wind wake effects were found to be significant, and normally resulted in higher temperatures on the leeward side of the tank. High wind conditions were found to be more severe than calm wind conditions. The use of four jets with two different temperatures was identified as a promising option in which the air temperatures were raised sufficiently to prevent ice formation on the external tank, without excessive increase in Orbiter surface temperature. The use of the numerical model also facilitated the selection of test configurations and a test matrix for verifying the approach. Selected results of an experimental verification (by using a 2 percent scale model in a wind tunnel) are also presented.

  16. Thermal history sensing of post-detonation environments with thermoluminescent microparticles

    NASA Astrophysics Data System (ADS)

    Mah, M.; Armstrong, P.; Lightstone, J.; Talghader, J.

    2011-06-01

    Thermoluminescent (TL) particles show promise as robust direct-contact thermal history sensors for explosive events. Research with microheaters has shown that TL microparticles can measure temperature excursions of hundreds of degrees; however, microheaters do not generate the severe pressure and shock stimuli present in post- detonation environments. To address this, TL particles were tested under conditions produced by the detonation of an aluminized explosive formulation. TLD-100 (LiF:Mg,Ti) powder was irradiated with 220 Gy of gamma radiation from a 167Cs source before being exposed to the free field detonation of a 20 gram charge. Particles were recovered post-detonation from two separate tests and their TL glow curves measured. At least two TL emission peaks 50 °C apart are clearly distinguishable in both samples, with peak intensity ratios decreasing 33.7% and 60.0% from an original 8.88:1, indicative of distinct carrier traps emptying at rates depending on the trap energy. These ratios agree well with thermocouple measurements from within the post-detonation fireball.

  17. Numerical modelling of distribution the discharged heat water from thermal power plant on the aquatic environment

    NASA Astrophysics Data System (ADS)

    Issakhov, Alibek

    2016-06-01

    The paper presents a mathematical model of distribution the discharged heat water from thermal power plant under various operational capacities on the aquatic environment. It was solved by the Navier-Stokes and temperature equations for an incompressible fluid in a stratified medium were based on the splitting method by physical parameters which approximated by the finite volume method. The numerical solution of the equation system was divided into four stages. At the first step it was assumed that the momentum transfer carried out only by convection and diffusion. While the intermediate velocity field was solved by 5-step Runge-Kutta method. At the second stage, the pressure field was solved by found the intermediate velocity field. Whereas Poisson equation for the pressure field was solved by Jacobi method. The third step assumes that the transfer was carried out only by pressure gradient. Finally the fourth step of the temperature equation was also solved as motion equations, with 5-step Runge-Kutta method. The algorithm was parallelized on high-performance computer. The obtained numerical results of three-dimensional stratified turbulent flow were compared with experimental data. What revealed qualitatively and quantitatively approximately the basic laws of hydrothermal processes occurring in the reservoir-cooler.

  18. Characterization of hydrogen environment anisotropic thermal etching and application to GaN nanostructure fabrication

    NASA Astrophysics Data System (ADS)

    Kita, Ryo; Hachiya, Ryo; Mizutani, Tomoya; Furuhashi, Hiroki; Kikuchi, Akihiko

    2015-04-01

    We report a new GaN etching technique with high anisotropy involving a thermal decomposition reaction in a low-pressure H2 environment. A GaN microridge stripe structure (5 µm in width and 1.2 µm in height) with extremely smooth sidewalls was fabricated at 1,050 °C and a H2 pressure of 10 Pa for 15 min using a SiO2 mask. The activation energy of the vertical etching was calculated to be 62-77 kcal/mol. In the GaN nanoridge stripe structure, the side etching under the SiO2 mask was less than 5 nm in depth and showed top width and height of ˜40 and ˜180 nm, respectively. The sidewall was extremely smooth and tilted by ˜15° from the m-plane along the a-axis, while being slightly rough and tilted by ˜30° from the a-plane along the m-axis. The \\{ n\\bar{n}02\\} (n = 4,5,6,7) planes were relatively stable in this etching technique.

  19. Aerothermodynamic environment and thermal protection for a Titan aerocapture vehicle. [Saturn satellite atmospheric entry

    NASA Technical Reports Server (NTRS)

    Green, M. J.; Moss, J. N.; Wilson, J. F.

    1984-01-01

    This paper presents thermal protection system (TPS) requirements for a potential Titan aerocapture vehicle. Shock-layer solutions are obtained for a nominal trajectory through the current Titan model atmosphere. Fully laminar and fully turbulent solutions are presented along the blunted fore-cone in the windward symmetry plane of a bent-biconic vehicle. Using these solutions to define the aerothermodynamic environment, transient material-response solutions are obtained for a Galileo-type TPS with a carbon-phenolic ablator heat shield. Shock-layer results indicate that turbulent flow is the more realistic flow condition. They also show that the lengthy aerocapture heating pulse is dominated by convective heating. The TPS results show that the required insulation thickness is uniformly about 4 cm along the fore-cone because of the long heat-soak period. The total heat-shield thickness is 6.4 cm at the stagnation point, and 4.7 cm near the end of the fore-cone. These TPS requirements are greater than those presented in a previous Titan aerocapture study.

  20. Non-thermal emission in astrophysical environments: From pulsars to supernova remnants

    NASA Astrophysics Data System (ADS)

    Lomiashvili, David

    The study of electromagnetic radiation from distant astrophysical objects provides essential data in understanding physics of these sources. In particular, non-thermal radiation provides great insight into the properties of local environments, particle populations, and emission mechanisms, knowledge which otherwise would remain untapped. Throughout the projects conducted for this dissertation, we modeled certain aspects of observed non-thermal emission from three classes of sources: radio pulsars, pulsar wind nebulae, and supernova remnants. Orbital variation in the double pulsar system PSR J0737-3039A/B can be used to probe the details of the magnetospheric structure of pulsar B. Strongly magnetized wind from pulsar A distorts the magnetosphere of pulsar B in a way similar to the solar wind's distortion of the Earth's magnetosphere. Using the two complimentary models of pulsar B's magnetosphere, adapted from the Earth's magnetosphere models by Dungey and Tsyganenko, we determine the precise location of the coherent radio emission generation region in pulsar B's magnetosphere. This analysis is complemented by modeling the observed evolution of the pulse profiles of B due to geodetic precession. The emission region is located at about 3750 stellar radii and has a horseshoe-like shape centered on the polar magnetic field lines. The best fit angular parameters of the emission region indicate that radio emission is generated on the field lines which, according to the theoretical models, originate close to the poles and carry the maximum current. When considered together, not only do the results of the two models converge, they can explain why the modulation of B's radio emission at A's period is observed only within a certain orbital phase region. We discuss the implications of these results for pulsar magnetospheric models and mechanisms of coherent radio emission generation. We also developed a spatially-resolved, analytic model for the high-energy non-thermal

  1. Insulation Performance of Heat-Resistant Material for High-Speed Aircraft Under Thermal Environments

    NASA Astrophysics Data System (ADS)

    Wu, Dafang; Wang, Yuewu; Gao, Zhentong; Yang, Jialing

    2015-09-01

    Lightweight insulation materials are widely used to thermally protect high-speed aircraft, such as missiles. Thermal conductivity is an important parameter used to evaluate the efficiency of a material's thermal insulation performance. Since thermal conductivities provided from material handbooks or manufacturers are discrete data for different temperature ranges, there is a deviation between those and actual parameters in terms of continuous nonlinear variations. Therefore, this study measures the thermal conductivities of lightweight thermal insulation materials at high temperatures, and the relationship between the thermal conductivity and temperature is obtained. A finite element model of the thermal insulation materials is also established and applied to numerically calculate the thermal insulation properties for high-temperature ceramic fiber insulation materials using the experimentally obtained nonlinear relationship between thermal conductivity and temperature. Additionally, a transient aerodynamic heating experiment simulation system is used to thermally test the same materials; the calculated and experimental results for the same materials are compared, which exhibit good consistency that demonstrates that accurate results can be obtained from the numerical computation using the relationship established from the experimentally measured conductivity and temperature.

  2. Long-term measurement of indoor thermal environment and energy performance in a detached wooden house with passive solar systems

    SciTech Connect

    Ishikawa, Yoshimi; Yoshino, Hiroshi; Sasaki, Chikashi

    1998-07-01

    The indoor thermal environment, energy performance and energy consumption for a detached wooden house equipped with two passive solar systems, were investigated over a period of three years. The house with a floor area of 188 m{sup 2} was constructed in the autumn of 1993 in Sendai, Japan; and was well insulated and very airtight compared with other houses in Japan. There are six occupants. Heating equipment is comprises of a thermal storage space heater using night-time electricity and a vented firewood furnace on the first floor. Each room is ventilated all day by a central ventilation system. Two passive solar systems were incorporated: a concrete floor in the southern perimeter of the living room as a direct gain system, and an earth tube embedded around the circumference of the house to supply fresh air. The principal results obtained are as follows: (1) The indoor environment during the heating season was more thermally comfortable, compared with that or ordinary houses in Japan. (2) The concrete floor played a role of thermal storage, which absorbed and released heat for decreasing the fluctuation of room temperature. (3) The earth tube supplied air with lower temperature in the summer and higher temperature in the winter to the room, that the outdoor air temperature. This thermal performance did not decrease in spite of the long-term use. (4) The annual amount of energy consumption of this house was less than that of ordinary houses in the northern part of Japan.

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    , depending on their size and tissue mass content. The design of individual thermal profiles is feasible for better comfort of astronauts on long-duration missions and personnel in other extreme environments.

  4. Studies on Lunar Base construction: architectural environment, thermal balance, economic technologies, local materials, on site assembly

    NASA Astrophysics Data System (ADS)

    Boldoghy, B.; Kummert, J.; Szilagyi, I.; Varga, T.; Berczi, Sz.

    We studied the strategies, technologies, designs of the Lunar Base architectural construction from the viewpoint of physical constraints (i.e. energy balance, strength and insulating properties of the lunar materials), engineering constraints (i.e. building technology, transports, insulating layers) and geological environment (allocation of the buildings). Our results contain proposals on the general strategy, on the local production technology, on arrangement and insulation solutions and the emplacement of the lunar base. We propose a complex architectural design for the lunar environment. It is economic to place the first long term used buildings below the surface. This way large mass of lunar soil can be used as insulator. Lunar soil can be moved by a lunar rover buldoser to cover the deposited container with regolith. We propose a double insulating layer system both using lunar soil as thermal insulator. We also propose a geological setting of the implementation of the architectural units in a groove or small valley mouth where not only the deposition of soil is economic but the enlargement of the station is possible in valley direction. Using the insulating and strength data of the lunar soil the following main technology phases of construction of the lunar base architecture are proposed. After transport of the primary container ISS type unit blocks from Earth to the lunar surface: 1) grading and basis forming in the bedrock for the frame, 2) assembly of the architectural constructions of the frame, (from frame units a spatial skeletal structure is built on the site which holds the stresses and load of the weight of both the cylindrical modules and the other insulating layers), 3) parallel filling the insulating quilted-coat like units with lunar fine soil, 4) fixing the quilted-coat like second insulating units to the surface of ISS type unit blocks, 5) final emplacement of the container blocks on the frame, 6) burial of the living bubble units by the lunar

  5. Testing of the Mars Exploration Rovers to Survive the Extreme Thermal Environments

    NASA Technical Reports Server (NTRS)

    Man, Kin F.; Hoffman, Alan R.

    2007-01-01

    Both Rovers have celebrated 3-year anniversaries on surface of Mars: a) More than ten times design life; b) Planned and implemented rigorous assembly and system level test programs; c) Demonstrated robust thermal margins; d)Tested both in vacuum and Mars atmosphere; e) Planned and implemented thermal cycling life qualification program; f) Demonstrated survival in deep thermal diurnal cycling and seasonal temperature variations; and g) Both Rovers continue to explore and return valuable science data

  6. Case study of skin temperature and thermal perception in a hot outdoor environment

    NASA Astrophysics Data System (ADS)

    Pantavou, Katerina; Chatzi, Evriklia; Theoharatos, George

    2014-08-01

    Focusing on the understanding and the estimation of the biometeorological conditions during summer in outdoor places, a field study was conducted in July 2010 in Athens, Greece over 6 days at three different sites: Syntagma Square, Ermou Street and Flisvos coast. Thermo-physiological measurements of five subjects were carried out from morning to evening for each site, simultaneously with meteorological measurements and subjective assessments of thermal sensation reported by questionnaires. The thermo-physiological variables measured were skin temperature, heat flux and metabolic heat production, while meteorological measurements included air temperature, relative humidity, wind speed, globe temperature, ground surface temperature and global radiation. The possible relation of skin temperature with the meteorological parameters was examined. Theoretical values of mean skin temperature and mean radiant temperature were estimated applying the MENEX model and were compared with the measured values. Two biometeorological indices, thermal sensation (TS) and heat load (HL)—were calculated in order to compare the predicted thermal sensation with the actual thermal vote. The theoretically estimated values of skin temperature were underestimated in relation to the measured values, while the theoretical model of mean radiant temperature was more sensitive to variations of solar radiation compared to the experimental values. TS index underestimated the thermal sensation of the five subjects when their thermal vote was `hot' or `very hot' and overestimated thermal sensation in the case of `neutral'. The HL index predicted with greater accuracy thermal sensation tending to overestimate the thermal sensation of the subjects.

  7. Urbanicity, social adversity and psychosis

    PubMed Central

    Heinz, Andreas; Deserno, Lorenz; Reininghaus, Ulrich

    2013-01-01

    In recent years, there has been increasing interest in research on geographical variation in the incidence of schizophrenia and other psychoses. In this paper, we review the evidence on variation in incidence of schizophrenia and other psychoses in terms of place, as well as the individual- and area-level factors that account for this variation. We further review findings on potential mechanisms that link adverse urban environment and psychosis. There is evidence from earlier and more recent studies that urbanicity is associated with an increased incidence of schizophrenia and non-affective psychosis. In addition, considerable variation in incidence across neighbourhoods has been observed for these disorders. Findings suggest it is unlikely that social drift alone can fully account for geographical variation in incidence. Evidence further suggests that the impact of adverse social contexts – indexed by area-level exposures such as population density, social fragmentation and deprivation – on risk of psychosis is explained (confounding) or modified (interaction) by environmental exposures at the individual level (i.e., cannabis use, social adversity, exclusion and discrimination). On a neurobiological level, several studies suggest a close link between social adversity, isolation and stress on the one hand, and monoamine dysfunction on the other, which resembles findings in schizophrenia patients. However, studies directly assessing correlations between urban stress or discrimination and neurobiological alterations in schizophrenia are lacking to date. PMID:24096775

  8. Thermally Induced Vibrations of the Hubble Space Telescope's Solar Array 3 in a Test Simulated Space Environment

    NASA Technical Reports Server (NTRS)

    Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)

    2001-01-01

    NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.

  9. The possible effects of the natural and induced space environment on the optical and thermal properties of EOS surfaces

    NASA Technical Reports Server (NTRS)

    Maag, Carl R.; Heppner, Richard A.

    1992-01-01

    Space missions, including that of EOS (Earth Observing System), will continue to be subjected to both the natural and induced space environment. The concerns associated with this fact will not go away. The NASA and DoD have recognized the need for long-life stability of materials and structures to the space environment. The major areas of interest include: thermal cycling, UV degradation, space radiation exposure, orbital debris, atomic oxygen erosion, and contamination control. Having flown a number of space environmental effects monitors, SAIC has developed both a data base to understand the magnitude of this problem and mitigation techniques to reduce the impact.

  10. The perceived temperature - a versatile index for the assessment of the human thermal environment. Part A: scientific basics

    NASA Astrophysics Data System (ADS)

    Staiger, Henning; Laschewski, Gudrun; Grätz, Angelika

    2012-01-01

    The Perceived Temperature (PT) is an equivalent temperature based on a complete heat budget model of the human body. It has proved its suitability for numerous applications across a wide variety of scales from micro to global and is successfully used both in daily forecasts and climatological studies. PT is designed for staying outdoors and is defined as the air temperature of a reference environment in which the thermal perception would be the same as in the actual environment. The calculation is performed for a reference subject with an internal heat production of 135 W m-2 (who is walking at 4 km h-1 on flat ground). In the reference environment, the mean radiant temperature equals the air temperature and wind velocity is reduced to a slight draught. The water vapour pressure remains unchanged. Under warm/humid conditions, however, it is implicitly related to a relative humidity of 50%. Clothing is adapted in order to achieve thermal comfort. If this is impossible, cold or heat stress will occur, respectively. The assessment of thermal perception by means of PT is based on Fanger's Predicted Mean Vote (PMV) together with additional model extensions taking account of stronger deviations from thermal neutrality. This is performed using a parameterisation based on a two-node model. In the cold, it allows the mean skin temperature to drop below the comfort value. In the heat, it assesses additionally the enthalpy of sweat-moistened skin and of wet clothes. PT has the advantages of being self-explanatory due to its deviation from air temperature and being—via PMV—directly linked to a thermo-physiologically-based scale of thermal perception that is widely used and has stood the test of time. This paper explains in detail the basic equations of the human heat budget and the coefficients of the parameterisations.

  11. Reconstruction of the thermal environment evolution from subsurface temperature distribution in Japan and Thailand

    NASA Astrophysics Data System (ADS)

    Hamamoto, H.; Yamano, M.; Goto, S.; Hachinohe, S.; Shiraishi, H.; Ishiyama, T.; Miyakoshi, A.; Taniguchi, M.; Arimoto, H.; Kitaoka, K.

    2012-12-01

    Temperature changes at the ground surface propagate into the underground and disturb the subsurface temperature structure. Analyzing disturbances in the subsurface temperature structure, we can reconstruct the past ground surface temperature (GST) change, which is closely related to the past surface air temperature change. This method can be applied to studies of thermal environment evolution in urban areas such as the development of "heat islands". We have been investigating GST histories in three areas, which are located in Japan and Thailand. The three areas are the northern part of Kanto area, Osaka area, and Bangkok area. Kanto area and Osaka area have the greatest and second greatest population in Japan, each other. Bangkok area has the greatest population in Thailand. In the northern part of Kanto area, we conducted measurements of temperature profiles in groundwater monitoring wells at 25 sites in 2009, 2010, and 2011. In Osaka area, temperature profiles were measured at 31 sites in 2011 as the project of the Sumitomo Foundation (M. Taniguchi). In Bangkok area, we measured temperature profiles at 45 sites in 2004, 2006, 2008, and 2010. We examined the shapes of the temperature profiles and selected ones that are not significantly disturbed by groundwater flow. Reconstruction of GST history for the last about 300 hundred years was made at two sites in the northern part of Kanto area, at six sites in Osaka area, and at six sites in Bangkok area. We used a multi-layer model that allows layers with different thermal properties, determining layer boundaries based on lithology of the formations around the wells. All of the reconstructed GST histories show surface warming in the last century. In the northern part of Kanto area, the amount of the temperature increase from 1700 to 2010 is about 2.5 K at both sites. In Osaka area, the amount of the temperature increase from 1700 to 2010 ranges from 2.5 K to 5.0 K and is larger in the city center and the southern part

  12. Thermal research of infrared sight signal processing circuit board under temperature shock environment

    NASA Astrophysics Data System (ADS)

    Gao, Youtang; Ding, Huang; Qiao, Jianliang; Xu, Yuan; Niu, Jun

    2015-10-01

    Thermal stability technology of signal processing circuit infrared sight is studied under temperature shock. Model parameters and geometry is configured for FPGA devices (EP1C20F400C8), solder material and PCB. Signal circuit boards of full array BGA distribution are simulated and analyzed by thermal shock and waveform through engineering finite element analysis software. Because solders of the whole model have strong stress along Y direction, initial stress constraints along Y direction are primarily considered when the partial model of single solder is imposed by thermal load. When absolute thermal loads stresses of diagonal nodes with maximum strains are separated from the whole model, interpolation is processed according to thermal loads circulation. Plastic strains and thermal stresses of nodes in both sides of partial model are obtained. The analysis results indicate that with thermal load circulation, maximum forces of each circulation along Y direction are increasingly enlarged and with the accumulation of plastic strains of danger point, the composition will become invalid in the end.

  13. Thermal research of infrared sight thermoelectric cooler control circuit under temperature environment

    NASA Astrophysics Data System (ADS)

    Gao, Youtang; Ding, Huan; Xue, Xiao; Xu, Yuan; Chang, Benkang

    2010-10-01

    Testing device TST-05B, which is suitable for adaptability test of semiconductor devices, electronic products and other military equipment under the condition of the surrounding air temperature rapidly changing, is used here for temperature shock test.Thermal stability technology of thermoelectric cooler control circuit infrared sight under temperature shock is studied in this paper. Model parameters and geometry is configured for ADI devices (ADN8830), welding material and PCB which are used in system. Thermoelectric cooler control circuit packaged by CSP32 distribution are simulated and analyzed by thermal shock and waveform through engineering finite element analysis software ANSYYS. Because solders of the whole model have much stronger stress along X direction than that of other directions, initial stress constraints along X direction are primarily considered when the partial model of single solder is imposed by thermal load. When absolute thermal loads stresses of diagonal nodes with maximum strains are separated from the whole model, interpolation is processed according to thermal loads circulation. Plastic strains and thermal stresses of nodes in both sides of partial model are obtained. The analysis results indicates that with thermal load circulation, maximum forces of each circulation along X direction are increasingly enlarged and with the accumulation of plastic strains of danger point, at the same time structural deformation and the location of maximum equivalent plastic strain in the solder joints at the first and eighth, the composition will become invalid in the end.

  14. Analysis of urbanization and climate change impacts on the urban thermal environment based on MODIS satellite data

    NASA Astrophysics Data System (ADS)

    Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.; Tautan, Marina N.; Baschir, Laurentiu A.

    2014-10-01

    Cities are exposed more and more to climate change from greenhouse gas induced radiative forcing, and localized effects from urbanization such as the urban heat island. Urban land covers as the biophysical state of the earth's surface and immediate subsurface are sources and sinks for most of the material and energy movements and interactions between the geosphere and biosphere. Climate change is considered to be the biggest environmental threat in the future in the South- Eastern part of Europe. The aim of this paper is to investigate the influences of urban growth on urban thermal environment as well as the relationships of thermal characteristics to other biophysical parameters in Bucharest metropolitan area of Romania based on time series MODIS Terra/Aqua and IKONOS data acquired during 2000-2014 periods. Land Surface Temperature (LST) is a key variable for studying urban land surface processes and surface atmosphere interactions, being a crucial component in the study of the surface energy and water budgets. Urbanization created an evolved inverse relationship between impervious and vegetation coverage, and brought about new LST patterns because of LST's correlations with both impervious and vegetation coverage. City thermal environment risk management strategies for mitigating and adapting to climate change must propose efficient plans to reduce greenhouse gas (GHG) emissions and cool the city through changes in the built environment, land use, and transportation.

  15. A nonventing cooling system for space environment extravehicular activity, using radiation and regenerable thermal storage

    NASA Technical Reports Server (NTRS)

    Bayes, Stephen A.; Trevino, Luis A.; Dinsmore, Craig E.

    1988-01-01

    This paper outlines the selection, design, and testing of a prototype nonventing regenerable astronaut cooling system for extravehicular activity space suit applications, for mission durations of four hours or greater. The selected system consists of the following key elements: a radiator assembly which serves as the exterior shell of the portable life support subsystem backpack; a layer of phase change thermal storage material, n-hexadecane paraffin, which acts as a regenerable thermal capacitor; a thermoelectric heat pump; and an automatic temperature control system. The capability for regeneration of thermal storage capacity with and without the aid of electric power is provided.

  16. Effect of Illumination Angle on the Performance of Dusted Thermal Control Surfaces in a Simulated Lunar Environment

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2009-01-01

    JSC-1A lunar simulant has been applied to AZ93 and AgFEP thermal control surfaces on aluminum substrates in a simulated lunar environment. The temperature of these surfaces was monitored as they were heated with a solar simulator using varying angles of incidence and cooled in a 30 K coldbox. Thermal modeling was used to determine the solar absorptivity (a) and infrared emissivity (e) of the thermal control surfaces in both their clean and dusted states. It was found that even a sub-monolayer of dust can significantly raise the a of either type of surface. A full monolayer can increase the a/e ratio by a factor of 3 to 4 over a clean surface. Little angular dependence of the a of pristine thermal control surfaces for both AZ93 and AgFEP was observed, at least until 30 from the surface. The dusted surfaces showed the most angular dependence of a when the incidence angle was in the range of 25 to 35 . Samples with a full monolayer, like those with no dust, showed little angular dependence in a. The e of the dusted thermal control surfaces was within the spread of clean surfaces, with the exception of high dust coverage, where a small increase was observed at shallow angles.

  17. Effect of Illumination Angle on the Performance of Dusted Thermal Control Surfaces in a Simulated Lunar Environment

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2009-01-01

    JSC-1A lunar simulant has been applied to AZ93 and AgFEP thermal control surfaces on aluminum substrates in a simulated lunar environment. The temperature of these surfaces was monitored as they were heated with a solar simulator using varying angles of incidence and cooled in a 30 K coldbox. Thermal modeling was used to determine the solar absorptivity (a) and infrared emissivity (e) of the thermal control surfaces in both their clean and dusted states. It was found that even a submonolayer of dust can significantly raise the a of either type of surface. A full monolayer can increase the a/e ratio by a factor of 3-4 over a clean surface. Little angular dependence of the a of pristine thermal control surfaces for both AZ93 and AgFEP was observed, at least until 300 from the surface. The dusted surfaces showed the most angular dependence of a when the incidence angle was in the range of 25 degrees to 35 degrees. Samples with a full monolayer, like those with no dust, showed little angular dependence in a. The e of the dusted thermal control surfaces was within the spread of clean surfaces, with the exception of high dust coverage, where a small increase was observed at shallow angles.

  18. Some Oobservations of the Role of Component Size in Solder Joint Degradation under Thermal Cycling Environments

    NASA Technical Reports Server (NTRS)

    Winslow, J.; Wen, L-C.

    1995-01-01

    Experimental results will be presented from a continuing investigation into the influence of component size and configuration of thermal cycling lifetimes, observed in a set of quadpak electronic component packages.

  19. Urban thermal environment measurements and numerical simulation for an actual complex urban area covering a large district heating and cooling system in summer

    NASA Astrophysics Data System (ADS)

    Huang, Hong; Ooka, Ryozo; Kato, Shinsuke

    Urban thermal situation is thought to have a great influence on the air quality in urban areas. In recent years, the urban thermal environment has become worse, such as the days on which the temperature goes above 30 °C, the sultry nights and heat stroke increase due to changes in terrestrial cover and increased anthropogenic heat emission accompanied by urbanization. Therefore, the urban thermal environment should be carefully investigated and accurately analyzed for a better study of the air quality. Here, in order to study the urban thermal environment in summer, (1) the actual status of an urban thermal environment in a complex urban area covering a large district heating and cooling (DHC) system in Tokyo is investigated using field measurements, and (2) a numerical simulation program which can be adapted to complex urban areas coupled with convection, radiation and conduction is developed and used to predict the urban thermal environment. Wind velocity, temperature and humidity are obtained from the simulation, which shows good agreement with results of the field measurement. The spatial distribution of the standard effective temperature (SET *), the comprehensive index of human thermal comfort, is also calculated using the above results, to estimate the thermal comfort at the pedestrian level. This urban thermal numerical simulation can be coupled with air pollution dispersion and chemical processes to provide a more precise air quality prediction in complex urban areas.

  20. Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments

    NASA Technical Reports Server (NTRS)

    Ramesham, Rajeshuni

    2013-01-01

    Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages of high interconnect density, very good thermal and electrical performance, and compatibility with standard surface-mount packaging assembly processes. CCGA packages are used in space applications such as in logics and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short- and long-term space missions. Certain planetary satellites require operations of thermally uncontrolled hardware under extremely cold and hot temperatures with large diurnal temperature change from day to night. The planetary protection requires the hardware to be baked at +125 C for 72 hours to kill microbugs to avoid any biological contamination, especially for sample return missions. Therefore, the present CCGA package reliability research study has encompassed the temperature range of 185 to +125 C to cover various NASA deep space missions. Advanced 1152 and 1272 CCGA packaging interconnects technology test hardware objects have been subjected to ex treme temperature thermal cycles from 185 to +125 C. X-ray inspections of CCGA packages have been made before thermal cycling. No anomalous behavior and process problems were observed in the x-ray images. The change in resistance of the daisy-chained CCGA interconnects was measured as a function of increasing number of thermal cycles. Electrical continuity measurements of daisy chains have shown no anomalies, even until 596 thermal cycles. Optical inspections of hardware have shown a significant fatigue for CCGA 1152 packages over CCGA 1272 packages. No catastrophic failures have been observed yet in the results. Process qualification and assembly are required to optimize the CCGA assembly processes. Optical inspections of CCGA boards have been made after 258 and 596 thermal

  1. Hybrid heating systems optimization of residential environment to have thermal comfort conditions by numerical simulation.

    PubMed

    Jahantigh, Nabi; Keshavarz, Ali; Mirzaei, Masoud

    2015-01-01

    The aim of this study is to determine optimum hybrid heating systems parameters, such as temperature, surface area of a radiant heater and vent area to have thermal comfort conditions. DOE, Factorial design method is used to determine the optimum values for input parameters. A 3D model of a virtual standing thermal manikin with real dimensions is considered in this study. Continuity, momentum, energy, species equations for turbulent flow and physiological equation for thermal comfort are numerically solved to study heat, moisture and flow field. K - ɛRNG Model is used for turbulence modeling and DO method is used for radiation effects. Numerical results have a good agreement with the experimental data reported in the literature. The effect of various combinations of inlet parameters on thermal comfort is considered. According to Pareto graph, some of these combinations that have significant effect on the thermal comfort require no more energy can be used as useful tools. A better symmetrical velocity distribution around the manikin is also presented in the hybrid system. PMID:26052442

  2. The cryptoendolithic microbial environment in the Ross Desert of Antarctica: mathematical models of the thermal regime

    NASA Technical Reports Server (NTRS)

    Nienow, J. A.; McKay, C. P.; Friedmann, E. I.

    1988-01-01

    Microbial activity in the Antarctic cryptoendolithic habitat is regulated primarily by temperature. Previous field studies have provided some information on the thermal regime in this habitat, but this type of information is limited by the remoteness of the site and the harsh climatic conditions. Therefore, a mathematical model of the endolithic thermal regime was constructed to augment the field data. This model enabled the parameters affecting the horizontal and altitudinal distribution of the community to be examined. The model predicts that colonization should be possible on surfaces with zenith angle less than 15 degrees. At greater zenith angles, colonization should be restricted to surfaces with azimuth angles less than 135 degrees or greater than 225 degrees. The upper elevational limit of the community should be less than 2,500 m. The thermal regime probably does not influence the zonation of the community within a rock.

  3. The cryptoendolithic microbial environment in the Ross Desert of Antarctica: mathematical models of the thermal regime.

    PubMed

    Nienow, J A; McKay, C P; Friedmann, E I

    1988-01-01

    Microbial activity in the Antarctic cryptoendolithic habitat is regulated primarily by temperature. Previous field studies have provided some information on the thermal regime in this habitat, but this type of information is limited by the remoteness of the site and the harsh climatic conditions. Therefore, a mathematical model of the endolithic thermal regime was constructed to augment the field data. This model enabled the parameters affecting the horizontal and altitudinal distribution of the community to be examined. The model predicts that colonization should be possible on surfaces with zenith angle less than 15 degrees. At greater zenith angles, colonization should be restricted to surfaces with azimuth angles less than 135 degrees or greater than 225 degrees. The upper elevational limit of the community should be less than 2,500 m. The thermal regime probably does not influence the zonation of the community within a rock. PMID:11538333

  4. The cryptoendolithic microbial environment in the Ross Desert of Antarctica: Mathematical models of the thermal regime.

    PubMed

    Nienow, J A; McKay, C P; Friedmann, E I

    1988-11-01

    Microbial activity in the Antarctic cryptoendolithic habitat is regulated primarily by temperature. Previous field studies have provided some information on the thermal regime in this habitat, but this type of information is limited by the remoteness of the site and the harsh climatic conditions. Therefore, a mathematical model of the endolithic thermal regime was constructed to augment the field data. This model enabled the parameters affecting the horizontal and altitudinal distribution of the community to be examined. The model predicts that colonization should be possible on surfaces with zenith angle less than 15°. At greater zenith angles, colonization should be restricted to surfaces with azimuth angles less than 135° or greater than 225°. The upper elevational limit of the community should be less than 2,500 m. The thermal regime probably does not influence the zonation of the community within a rock. PMID:24201713

  5. Effect of Simulant Type on the Absorptance and Emittance of Dusted Thermal Control Surfaces in a Simulated Lunar Environment

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2010-01-01

    During the Apollo program the effects of lunar dust on thermal control surfaces was found to be more significant than anticipated, with several systems overheating due to deposition of dust on them. In an effort to reduce risk to future missions, a series of tests has been initiated to characterize the effects of dust on these surfaces, and then to develop technologies to mitigate that risk. Given the variations in albedo across the lunar surface, one variable that may be important is the darkness of the lunar dust, and this study was undertaken to address that concern. Three thermal control surfaces, AZ-93 white paint and AgFEP and AlFEP second surface mirrors were dusted with three different lunar dust simulants in a simulated lunar environment, and their solar absorptivity and thermal emissivity values determined experimentally. The three simulants included JSC 1AF, a darker mare simulant, NU-LHT-1D, a light highlands simulant, and 1:1 mixture of the two. The response of AZ-93 was found to be slightly more pronounced than that of AgFEP. The increased with fractional dust coverage in both types of samples by a factor of 1.7 to 3.3, depending on the type of thermal control surface and the type of dust. The of the AZ-93 decreased by about 10 percent when fully covered by dust, while that of AgFEP increased by about 10 percent. It was found that alpha/epsilon varied by more than a factor of two depending on the thermal control surface and the darkness of the dust. Given that the darkest simulant used in this study may be significantly lighter than the darkest dust that could be encountered on the lunar surface, it becomes apparent that the performance degradation of thermal control surfaces due to dust on the moon will be strongly dependent on the and of the dust in the specific locality.

  6. Effect of Simulant Type on the Absorptance and Emittance of Dusted Thermal Control Surfaces in a Simulated Lunar Environment

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2010-01-01

    During the Apollo program the effects of lunar dust on thermal control surfaces was found to be more significant than anticipated, with several systems overheating due to deposition of dust on them. In an effort to reduce risk to future missions, a series of tests has been initiated to characterize the effects of dust on these surfaces, and then to develop technologies to mitigate that risk. Given the variations in albedo across the lunar surface, one variable that may be important is the darkness of the lunar dust, and this study was undertaken to address that concern. Three thermal control surfaces, AZ-93 white paint and AgFEP and AlFEP second surface mirrors were dusted with three different lunar dust simulants in a simulated lunar environment, and their integrated solar absorptance ( ) and thermal emittance ( ) values determined experimentally. The three simulants included JSC-1AF, a darker mare simulant, NU-LHT-1D, a light highlands simulant, and 1:1 mixture of the two. The response of AZ-93 was found to be slightly more pronounced than that of AgFEP. The increased with fractional dust coverage in both types of samples by a factor of 1.7 to 3.3, depending on the type of thermal control surface and the type of dust. The of the AZ-93 decreased by about 10 percent when fully covered by dust, while that of AgFEP increased by about 10 percent. It was found that / varied by more than a factor of two depending on the thermal control surface and the darkness of the dust. Given that the darkest simulant used in this study may be lighter than the darkest dust that could be encountered on the lunar surface, it becomes apparent that the performance degradation of thermal control surfaces due to dust on the Moon will be strongly dependent on the and of the dust in the specific locality

  7. Dynamic modeling of human thermal comfort after the transition from an indoor to an outdoor hot environment

    NASA Astrophysics Data System (ADS)

    Katavoutas, George; Flocas, Helena A.; Matzarakis, Andreas

    2015-02-01

    Thermal comfort under non-steady-state conditions primarily deals with rapid environmental transients and significant alterations of the meteorological conditions, activity, or clothing pattern within the time scale of some minutes. In such cases, thermal history plays an important role in respect to time, and thus, a dynamic approach is appropriate. The present study aims to investigate the dynamic thermal adaptation process of a human individual, after his transition from a typical indoor climate to an outdoor hot environment. Three scenarios of thermal transients have been considered for a range of hot outdoor environmental conditions, employing the dynamic two-node IMEM model. The differences among them concern the radiation field, the activity level, and the body position. The temporal pattern of body temperatures as well as the range of skin wettedness and of water loss have been investigated and compared among the scenarios and the environmental conditions considered. The structure and the temporal course of human energy fluxes as well as the identification of the contribution of body temperatures to energy fluxes have also been studied and compared. In general, the simulation results indicate that the response of a person, coming from the same neutral indoor climate, varies depending on the scenario followed by the individual while being outdoors. The combination of radiation field (shade or not) with the kind of activity (sitting or walking) and the outdoor conditions differentiates significantly the thermal state of the human body. Therefore, 75 % of the skin wettedness values do not exceed the thermal comfort limit at rest for a sitting individual under the shade. This percentage decreases dramatically, less than 25 %, under direct solar radiation and exceeds 75 % for a walking person under direct solar radiation.

  8. Effect of thermal environment on the temporal, spatial and seasonal occurrence of measles in Ondo state, Nigeria

    NASA Astrophysics Data System (ADS)

    Omonijo, Akinyemi Gabriel; Matzarakis, Andreas; Oguntoke, Olusegun; Adeofun, Clement Olabinjo

    2012-09-01

    We investigated the temporal and spatial dynamics, as well as the seasonal occurrence of measles in Ondo state, Nigeria, to better understand the role of the thermal environment in the occurrence of the childhood killer disease measles, which ranks among the top ten leading causes of child deaths worldwide. The linkages between measles and atmospheric environmental factors were examined by correlating human-biometeorological parameters in the study area with reported clinical cases of measles for the period 1998-2008. We also applied stepwise regression analysis in order to determine the human-biometeorological parameters that lead to statistical changes in reported clinical cases of measles. We found that high reported cases of measles are associated with the least populated areas, where rearing and cohabitation of livestock/domestic animals within human communities are common. There was a significant correlation ( P < 0.01) between monthly cases of measles and human-biometeorological parameters except wind speed and vapour pressure. High transmission of measles occurred in the months of January to May during the dry season when human thermal comfort indices are very high. This highlights the importance of the thermal environment in disease demographics since it accounted for more than 40% variation in measles transmission within the study period.

  9. Robust vehicle detection under various environments to realize road traffic flow surveillance using an infrared thermal camera.

    PubMed

    Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

    2015-01-01

    To realize road traffic flow surveillance under various environments which contain poor visibility conditions, we have already proposed two vehicle detection methods using thermal images taken with an infrared thermal camera. The first method uses pattern recognition for the windshields and their surroundings to detect vehicles. However, the first method decreases the vehicle detection accuracy in winter season. To maintain high vehicle detection accuracy in all seasons, we developed the second method. The second method uses tires' thermal energy reflection areas on a road as the detection targets. The second method did not achieve high detection accuracy for vehicles on left-hand and right-hand lanes except for two center-lanes. Therefore, we have developed a new method based on the second method to increase the vehicle detection accuracy. This paper proposes the new method and shows that the detection accuracy for vehicles on all lanes is 92.1%. Therefore, by combining the first method and the new method, high vehicle detection accuracies are maintained under various environments, and road traffic flow surveillance can be realized. PMID:25763384

  10. Effect of thermal environment on the temporal, spatial and seasonal occurrence of measles in Ondo state, Nigeria.

    PubMed

    Omonijo, Akinyemi Gabriel; Matzarakis, Andreas; Oguntoke, Olusegun; Adeofun, Clement Olabinjo

    2012-09-01

    We investigated the temporal and spatial dynamics, as well as the seasonal occurrence of measles in Ondo state, Nigeria, to better understand the role of the thermal environment in the occurrence of the childhood killer disease measles, which ranks among the top ten leading causes of child deaths worldwide. The linkages between measles and atmospheric environmental factors were examined by correlating human-biometeorological parameters in the study area with reported clinical cases of measles for the period 1998-2008. We also applied stepwise regression analysis in order to determine the human-biometeorological parameters that lead to statistical changes in reported clinical cases of measles. We found that high reported cases of measles are associated with the least populated areas, where rearing and cohabitation of livestock/domestic animals within human communities are common. There was a significant correlation (P < 0.01) between monthly cases of measles and human-biometeorological parameters except wind speed and vapour pressure. High transmission of measles occurred in the months of January to May during the dry season when human thermal comfort indices are very high. This highlights the importance of the thermal environment in disease demographics since it accounted for more than 40% variation in measles transmission within the study period. PMID:21928098

  11. Robust Vehicle Detection under Various Environments to Realize Road Traffic Flow Surveillance Using an Infrared Thermal Camera

    PubMed Central

    Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

    2015-01-01

    To realize road traffic flow surveillance under various environments which contain poor visibility conditions, we have already proposed two vehicle detection methods using thermal images taken with an infrared thermal camera. The first method uses pattern recognition for the windshields and their surroundings to detect vehicles. However, the first method decreases the vehicle detection accuracy in winter season. To maintain high vehicle detection accuracy in all seasons, we developed the second method. The second method uses tires' thermal energy reflection areas on a road as the detection targets. The second method did not achieve high detection accuracy for vehicles on left-hand and right-hand lanes except for two center-lanes. Therefore, we have developed a new method based on the second method to increase the vehicle detection accuracy. This paper proposes the new method and shows that the detection accuracy for vehicles on all lanes is 92.1%. Therefore, by combining the first method and the new method, high vehicle detection accuracies are maintained under various environments, and road traffic flow surveillance can be realized. PMID:25763384

  12. Nonlocal thermo-mechanical vibration analysis of functionally graded nanobeams in thermal environment

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Farzad; Salari, Erfan

    2015-08-01

    In this paper, the thermal effect on free vibration characteristics of functionally graded (FG) size-dependent nanobeams subjected to various types of thermal loading is investigated by presenting a Navier type solution and employing a semi analytical differential transform method (DTM) for the first time. Two kinds of thermal loading, namely, linear temperature rise and nonlinear temperature rise are studied. Material properties of FG nanobeam are supposed to vary continuously along the thickness according to the power-law form and the material properties are assumed to be temperature-dependent. The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen. The nonlocal equations of motion are derived through Hamilton's principle and they are solved applying DTM. According to the numerical results, it is revealed that the proposed modeling and semi analytical approach can provide accurate frequency results of the FG nanobeams as compared to analytical results and also some cases in the literature. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as thermal effect, material distribution profile, small scale effects, mode number and boundary conditions on the normalized natural frequencies of the temperature-dependent FG nanobeams in detail. It is explicitly shown that the vibration behaviour of a FG nanobeams is significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of FG nanobeams.

  13. Thermal waters and the effect of their use on the environment

    SciTech Connect

    Dvorov, I.M.; Dvorov, V.I.

    1982-01-01

    A few of the many types and quantities of salt and gas components in hydrothermal waters are examined. In successive order, the chemical composition of hydrothermal fluids are considered from fresh water to brines. The undesirable effects of the thermoenergetic and chemical use of thermal waters on nature are considered. (MHR)

  14. Computation of Coupled Thermal-Fluid Problems in Distributed Memory Environment

    NASA Technical Reports Server (NTRS)

    Wei, H.; Shang, H. M.; Chen, Y. S.

    2001-01-01

    The thermal-fluid coupling problems are very important to aerospace and engineering applications. Instead of analyzing heat transfer and fluid flow separately, this study merged two well-accepted engineering solution methods, SINDA for thermal analysis and FDNS for fluid flow simulation, into a unified multi-disciplinary thermal fluid prediction method. A fully conservative patched grid interface algorithm for arbitrary two-dimensional and three-dimensional geometry has been developed. The state-of-the-art parallel computing concept was used to couple SINDA and FDNS for the communication of boundary conditions through PVM (Parallel Virtual Machine) libraries. Therefore, the thermal analysis performed by SINDA and the fluid flow calculated by FDNS are fully coupled to obtain steady state or transient solutions. The natural convection between two thick-walled eccentric tubes was calculated and the predicted results match the experiment data perfectly. A 3-D rocket engine model and a real 3-D SSME geometry were used to test the current model, and the reasonable temperature field was obtained.

  15. Designing Experiments on Thermal Interactions by Secondary-School Students in a Simulated Laboratory Environment

    ERIC Educational Resources Information Center

    Lefkos, Ioannis; Psillos, Dimitris; Hatzikraniotis, Euripides

    2011-01-01

    Background and purpose: The aim of this study was to explore the effect of investigative activities with manipulations in a virtual laboratory on students' ability to design experiments. Sample: Fourteen students in a lower secondary school in Greece attended a teaching sequence on thermal phenomena based on the use of information and…

  16. Evaluation of ULV and thermal fog mosquito control applications in temperate and desert environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ultra low volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only seven studies have been identified that directly compare their performance in the fiel...

  17. Evaluation of ULV and Thermal Fog Mosquito Control Applications in Temperate and Desert Environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ultra low volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only 7 studies have been identified that directly compare their performance in the field. U...

  18. Thermal environment in a four-horse slant-load trailer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information has been published describing thermal conditions in horse trailers while in transit. Dry bulb temperature (Tdb), globe temperature (Tg), and relative humidity (RH) were measured in ten locations within a fully enclosed four-horse slant-load trailer with and without animals to asse...

  19. Integrated Design Engineering Analysis (IDEA) Environment - Aerodynamics, Aerothermodynamics, and Thermal Protection System Integration Module

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hilmi N.

    2011-01-01

    This report documents the work performed during from March 2010 October 2011. The Integrated Design and Engineering Analysis (IDEA) environment is a collaborative environment based on an object-oriented, multidisciplinary, distributed environment using the Adaptive Modeling Language (AML) as the underlying framework. This report will focus on describing the work done in the area of extending the aerodynamics, and aerothermodynamics module using S/HABP, CBAERO, PREMIN and LANMIN. It will also detail the work done integrating EXITS as the TPS sizing tool.

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  1. Study Task for Determining the Effects of Boost-Phase Environments on Densified Propellants Thermal Conditions for Expendable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Haberbusch, Mark S.; Meyer, Michael L. (Technical Monitor)

    2002-01-01

    A thermodynamic study has been conducted that investigated the effects of the boost-phase environment on densified propellant thermal conditions for expendable launch vehicles. Two thermodynamic models were developed and utilized to bound the expected thermodynamic conditions inside the cryogenic liquid hydrogen and oxygen propellant tanks of an Atlas IIAS/Centaur launch vehicle during the initial phases of flight. The ideal isentropic compression model was developed to predict minimum pressurant gas requirements. The thermal equilibrium model was developed to predict the maximum pressurant gas requirements. The models were modified to simulate the required flight tank pressure profiles through ramp pressurization, liquid expulsion, and tank venting. The transient parameters investigated were: liquid temperature, liquid level, and pressurant gas consumption. Several mission scenarios were analyzed using the thermodynamic models, and the results indicate that flying an Atlas IIAS launch vehicle with densified propellants is feasible and beneficial but may require some minor changes to the vehicle.

  2. Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Knipe, Kevin; Manero, Albert; Siddiqui, Sanna F.; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M.; Bartsch, Marion; Raghavan, Seetha

    2014-07-01

    The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.

  3. Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction.

    PubMed

    Knipe, Kevin; Manero, Albert; Siddiqui, Sanna F; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M; Bartsch, Marion; Raghavan, Seetha

    2014-01-01

    The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface. PMID:25078347

  4. Leak rate measurements for satellite subsystems and residual gas analysis during space environment tests. [thermal vacuum and solar simulation tests

    NASA Technical Reports Server (NTRS)

    Nuss, H. E.

    1975-01-01

    The measuring and evaluation procedure for the determination of leak rates of satellite subsystems with a quadrupole mass spectrometer, and the results of the residual gas analysis are described. The method selected for leak rate determination was placing the system into a vacuum chamber and furnishing the chamber with a mass spectrometer and calibrated leaks. The residual gas of a thermal vacuum test facility, in which the thermal balance test radiation input was simulated by a heated canister, was analyzed with the mass spectrometer in the atomic mass unit range up to 300 amu. In addition to the measurements during the space environment tests, mass spectrometric studies were performed with samples of spacecraft materials. The studies were carried out during tests for the projects HELIOS, AEROS B and SYMPHONIE.

  5. Effects of Non-Uniform Wall Heating on Thermal and Momentum Fields in a 3-Dimensional Urban Environment

    NASA Astrophysics Data System (ADS)

    Nazarian, N.; Kleissl, J. P.

    2014-12-01

    As urbanization progresses, microclimate modifications are also aggravated and the increasing environmental concerns call for more sophisticated methods of urban microclimate analysis. Comprehensive numerical simulations for a clear summer day in southern California are performed in a compact low-rise urban environment. The effect of realistic unsteady, non-uniform thermal forcing, that is caused by solar insolation and inter-building shadowing on thermal and flow conditions are analyzed based on Algebraic Wall-Modeled Large Eddy Simulation (LES) model. The urban thermal field is influenced by urban density, material properties and local weather conditions, as well as urban canyon flow. Urban canyon conditions are translated into vertical and horizontal bulk Richardson numbers indicating atmospheric instability and solar tilt with respect to the momentum forcing of the canyon vortex, respectively. The effect of roof heating is found to be critical on the vortex formation between buildings when the vertical bulk Richardson number is low. Variations of Convective Heat Transfer Coefficients (CHTCs) along building walls are studied and the street canyon ventilation performance is characterized by the mean of air exchange rate (ACH). It is found that volumetric air exchange from street canyons, as well as the distribution of heat transfer along the wall depends strongly on the three-dimensional orientation of the heated wall in relation to wind direction. For example, air removal increases by surface heating and is larger when the leeward wall is heated. In summary, we demonstrate the importance of considering complex realistic conditions on 3-dimensional thermal and momentum fields in Urban Environments.

  6. Peptide formation in the prebiotic era - Thermal condensation of glycine in fluctuating clay environments

    NASA Technical Reports Server (NTRS)

    Lahav, N.; White, D.; Chang, S.

    1978-01-01

    As geologically relevant models of prebiotic environments, systems consisting of clay, water, and amino acids were subjected to cyclic variations in temperature and water content. Fluctuations of both variables produced longer oligopeptides in higher yields than were produced by temperature fluctuations alone. The results suggest that fluctuating environments provided a favorable geological setting in which the rate and extent of chemical evolution would have been determined by the number and frequency of cycles.

  7. The influence of the free space environment on the superlight-weight thermal protection system: conception, methods, and risk analysis

    NASA Astrophysics Data System (ADS)

    Yatsenko, Vitaliy; Falchenko, Iurii; Fedorchuk, Viktor; Petrushynets, Lidiia

    2016-07-01

    This report focuses on the results of the EU project "Superlight-weight thermal protection system for space application (LIGHT-TPS)". The bottom line is an analysis of influence of the free space environment on the superlight-weight thermal protection system (TPS). This report focuses on new methods that based on the following models: synergetic, physical, and computational. This report concentrates on four approaches. The first concerns the synergetic approach. The synergetic approach to the solution of problems of self-controlled synthesis of structures and creation of self-organizing technologies is considered in connection with the super-problem of creation of materials with new functional properties. Synergetics methods and mathematical design are considered according to actual problems of material science. The second approach describes how the optimization methods can be used to determine material microstructures with optimized or targeted properties. This technique enables one to find unexpected microstructures with exotic behavior (e.g., negative thermal expansion coefficients). The third approach concerns the dynamic probabilistic risk analysis of TPS l elements with complex characterizations for damages using a physical model of TPS system and a predictable level of ionizing radiation and space weather. Focusing is given mainly on the TPS model, mathematical models for dynamic probabilistic risk assessment and software for the modeling and prediction of the influence of the free space environment. The probabilistic risk assessment method for TPS is presented considering some deterministic and stochastic factors. The last approach concerns results of experimental research of the temperature distribution on the surface of the honeycomb sandwich panel size 150 x 150 x 20 mm at the diffusion welding in vacuum are considered. An equipment, which provides alignment of temperature fields in a product for the formation of equal strength of welded joints is

  8. Time-dependent deformation of surface geometry on light weight and thermally stable CFRP mirror in humid environment

    NASA Astrophysics Data System (ADS)

    Arao, Yoshihiko; Koyanagi, Jun; Utsunomiya, Shin; Takeda, Shin-ichi; Kawada, Hiroyuki

    2010-07-01

    CFRP (Carbon Fiber Reinforced Plastics) is the ideal material for space based mirror due to its low thermal expansion, and high specific modulus. To expand the use of CFRP, we investigated the long-term stability of CFRP under humid environment. CFRP mirror was made as precise as possible by using special class of material and adopting particular design techniques. Dimensional stability of CFRP mirror was evaluated by nano-scale measurement. The factors which cause out-of-plane deformation of the mirror is discussed.

  9. Adverse weather impacts on arable cropping systems

    NASA Astrophysics Data System (ADS)

    Gobin, Anne

    2016-04-01

    Damages due to extreme or adverse weather strongly depend on crop type, crop stage, soil conditions and management. The impact is largest during the sensitive periods of the farming calendar, and requires a modelling approach to capture the interactions between the crop, its environment and the occurrence of the meteorological event. The hypothesis is that extreme and adverse weather events can be quantified and subsequently incorporated in current crop models. Since crop development is driven by thermal time and photoperiod, a regional crop model was used to examine the likely frequency, magnitude and impacts of frost, drought, heat stress and waterlogging in relation to the cropping season and crop sensitive stages. Risk profiles and associated return levels were obtained by fitting generalized extreme value distributions to block maxima for air humidity, water balance and temperature variables. The risk profiles were subsequently confronted with yields and yield losses for the major arable crops in Belgium, notably winter wheat, winter barley, winter oilseed rape, sugar beet, potato and maize at the field (farm records) to regional scale (statistics). The average daily vapour pressure deficit (VPD) and reference evapotranspiration (ET0) during the growing season is significantly lower (p < 0.001) and has a higher variability before 1988 than after 1988. Distribution patterns of VPD and ET0 have relevant impacts on crop yields. The response to rising temperatures depends on the crop's capability to condition its microenvironment. Crops short of water close their stomata, lose their evaporative cooling potential and ultimately become susceptible to heat stress. Effects of heat stress therefore have to be combined with moisture availability such as the precipitation deficit or the soil water balance. Risks of combined heat and moisture deficit stress appear during the summer. These risks are subsequently related to crop damage. The methodology of defining

  10. Automobile Industry‧s Action on Environments and Relevant Thermal and Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Kobayashi, Nobuo; Ikegami, Tohru

    To enhance the environmental performance of vehicles, CO2 emission should be reduced and the fuel efficiency should be improved. The fuel efficiency can be improved by reducing the aerodynamic drag of vehicles and improving the thermal efficiency of engines. Further improvement can be achieved by currently developed systems such as the hybrid vehicle (HV), which employs the internal combustion engine and the motor, and by the fuel cell vehicle, which does not require fossil fuel. However, HV and FCHV (Fuel Cell Hybrid Vehicle) have piles of concerns to be tackled such as thermal issues of new devices including the motor, the inverter, the battery and the fuel cell. This paper reviews the thermo-fluid dynamic approaches, which are indispensable to manage these concerns.

  11. Bypass Diode Temperature Tests of a Solar Array Coupon Under Space Thermal Environment Conditions

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon

    2016-01-01

    Tests were performed on a 56-cell Advanced Triple Junction solar array coupon whose purpose was to determine margin available for bypass diodes integrated with new, large multi-junction solar cells that are manufactured from a 4-inch wafer. The tests were performed under high vacuum with coupon back side thermal conditions of both cold and ambient. The bypass diodes were subjected to a sequence of increasing discrete current steps from 0 Amp to 2.0 Amp in steps of 0.25 Amp. At each current step, a temperature measurement was obtained via remote viewing by an infrared camera. This paper discusses the experimental methodology, experiment results, and the thermal model.

  12. An inhomogeneous thermal block model of man for the electromagnetic environment

    SciTech Connect

    Chatterjee, I.; Gandhi, O.P.

    1983-11-01

    An inhomogeneous four layer block thermal model of a human body, composed of 476 electromagnetic-sensitive cubical cells has been developed to study the effects of electromagnetic radiation. Varying tissue properties defined by thermal conductivity, specific heat, blood flow rate and metabolic heat production are accounted for by equations. Peripheral cell temperature is weight-averaged for total cell volume and is thereby higher than actual skin temperature. During electromagnetic field exposure, additional factors considered are increased blood flow rate caused by vasodilation and sweat-induced heat loss. Hot spots have been located in the model and numerical results are presented. Subjected to plane wave iradiation, the model's sweating and insensible perspiration cease and all temperatures converge. Testing during electromagnetic hyperthemia shows all temperature body parts to increase approximately at the same rate.

  13. Adverse reactions to sulfites

    PubMed Central

    Yang, William H.; Purchase, Emerson C.R.

    1985-01-01

    Sulfites are widely used as preservatives in the food and pharmaceutical industries. In the United States more than 250 cases of sulfite-related adverse reactions, including anaphylactic shock, asthmatic attacks, urticaria and angioedema, nausea, abdominal pain and diarrhea, seizures and death, have been reported, including 6 deaths allegedly associated with restaurant food containing sulfites. In Canada 10 sulfite-related adverse reactions have been documented, and 1 death suspected to be sulfite-related has occurred. The exact mechanism of sulfite-induced reactions is unknown. Practising physicians should be aware of the clinical manifestations of sulfite-related adverse reactions as well as which foods and pharmaceuticals contain sulfites. Cases should be reported to health officials and proper advice given to the victims to prevent further exposure to sulfites. The food industry, including beer and wine manufacturers, and the pharmaceutical industry should consider using alternative preservatives. In the interim, they should list any sulfites in their products. PMID:4052897

  14. S-2 stage 1/25 scale model base region thermal environment test. Volume 1: Test results, comparison with theory and flight data

    NASA Technical Reports Server (NTRS)

    Sadunas, J. A.; French, E. P.; Sexton, H.

    1973-01-01

    A 1/25 scale model S-2 stage base region thermal environment test is presented. Analytical results are included which reflect the effect of engine operating conditions, model scale, turbo-pump exhaust gas injection on base region thermal environment. Comparisons are made between full scale flight data, model test data, and analytical results. The report is prepared in two volumes. The description of analytical predictions and comparisons with flight data are presented. Tabulation of the test data is provided.

  15. Influence of sky view factor on outdoor thermal environment and physiological equivalent temperature

    NASA Astrophysics Data System (ADS)

    He, Xiaodong; Miao, Shiguang; Shen, Shuanghe; Li, Ju; Zhang, Benzhi; Zhang, Ziyue; Chen, Xiujie

    2015-03-01

    Sky view factor (SVF), which is an indicator of urban canyon geometry, affects the surface energy balance, local air circulation, and outdoor thermal comfort. This study focused on a continuous and long-term meteorological observation system to investigate the effects of SVF on outdoor thermal conditions and physiological equivalent temperature (PET) in the central business district (CBD) of Beijing (which is located within Chaoyang District), specifically addressed current knowledge gaps for SVF-PET relationships in cities with typical continental/microthermal climates. An urban sub-domain scale model and the RayMan model were used to diagnose wind fields and to calculate SVF and long-term PET, respectively. Analytical results show that the extent of shading contributes to variations in thermal perception distribution. Highly shaded areas (SVF <0.3) typically exhibit less frequent hot conditions during summer, while enduring longer periods of cold discomfort in winter than moderately shaded areas (0.3< SVF <0.5) and slightly shaded areas (SVF >0.5), and vice versa. Because Beijing has a monsoon-influenced humid continental climate with hot summers and long, cold, windy, and dry winters, a design project that ideally provides moderate shading should be planned to balance hot discomfort in summer and cold discomfort in winter, which effectively prolongs the comfort periods in outdoor spaces throughout the entire year. This research indicate that climate zone characteristics, urban environmental conditions, and thermal comfort requirements of residents must be accounted for in local-scale scientific planning and design, i.e., for urban canyon streets and residential estates.

  16. A New Approach to Predicting the Thermal Environment in Buildings at the Early Design Stage. Building Research Establishment Current Paper 2/74.

    ERIC Educational Resources Information Center

    Milbank, N. O.

    The paper argues that existing computer programs for thermal predictions do not produce suitable information for architects, particularly at the early stages of design. It reviews the important building features that determine the thermal environment and the need for heating and cooling plant. Graphical design aids are proposed, with examples to…

  17. Human requirements to the indoor air quality and the thermal environment

    NASA Astrophysics Data System (ADS)

    Fanger, P. Ole

    Perceived air quality, general thermal sensation of the occupants and risk of draft, aspects which human comfort in a space depends upon, are reviewed separately based on European Guidelines for Ventilation Requirements in Buildings and on a modified ISO (International Standards Organization) standard 7730 on thermal comfort. The perceived air quality is expressed in decipol or percentage of dissatisfied occupants. The general thermal sensation is expressed by the PMV/PPD indices. The perception of draft is expressed by the model of draft risk. Indoor air quality is mediocre and causes complaints in many buildings. The reason for this is often hidden pollution sources in the building, hitherto ignored in previous ventilation standards. To determine the required ventilation, a method is used in the European Guidelines. The new Guidelines acknowledge all pollution sources in the building, expressed in olfs. The method is based on the desired air quality in the space, the available quality of the outdoor air, the ventilation effectiveness and on the total pollution load in the space. The model of draft risk predicts the percentage of occupants feeling draft as a function of the mean air velocity, the turbulence intensity and the air temperature.

  18. Thermal preferences and limits of Triatoma brasiliensis in its natural environment - Field observations while host searching

    PubMed Central

    Catalá, Silvia; Bezerra, Claudia Mendonça; Diotaiuti, Lileia

    2015-01-01

    The goal of this work was to explore the thermal relationship between foraging Triatoma brasiliensis and its natural habitat during the hottest season in the state of Ceará, Brazil. The thermal profiles were determined using infrared analysis. Although the daily temperature of rock surfaces varied in a wide range, T. brasiliensis selected to walk through areas with temperatures between 31.7-40.5ºC. The temperature of T. brasiliensis body surface ranged from 32.8-34.4ºC, being higher in legs than the abdomen. A strong relationship was found between the temperature of the insect and the temperature of rock crevices where they were hidden (r: 0.96, p < 0.05). The species was active at full sunlight being a clear example of how the light-dark rhythm may be altered, even under predation risk. Our results strongly suggest a thermal borderline for T. brasiliensis foraging activity near 40ºC. The simultaneous determination of insect body and rock temperatures here presented are the only obtained in natural habitats for this or other triatomines. PMID:26517659

  19. Thermal Behavior of Fe2O3/Al Thermite Mixtures in Air and Vacuum Environments

    SciTech Connect

    Duraes, L.; Santos, R.; Correia, A.; Campos, J.; Portugal, A.

    2006-07-28

    In this work, the thermal behavior of Fe2O3/Al thermite mixtures, in air and vacuum, is studied. The individual reactants and three mixtures - stoichiometric and over aluminized - are tested, by Simultaneous Thermal Analysis (STA) and heating microscopy, with a heating rate of 10 deg. C/min. The STA results show that the presence of O2 from air, or from residual air in vacuum, influenced the reaction scheme. The Al oxidation by this oxygen was extensive, making the thermite reaction with Fe2O3 unviable. There was also evidence of significant conversion of the Fe2O3 into Fe3O4, supporting the previous conclusion. So, the STA curves for the three mixtures were similar and displayed features of the individual reactants' curves. The heating microscopy images confirmed the STA conclusions, with one exception: the thermal explosion of the Al sample close to 550 deg. C. The absence of this phenomenon in STA results was explained by the limited amount of material used in each sample.

  20. Genetic divergence and isolation by thermal environment in geothermal populations of an aquatic invertebrate.

    PubMed

    Johansson, M P; Quintela, M; Laurila, A

    2016-09-01

    Temperature is one of the most influential forces of natural selection impacting all biological levels. In the face of increasing global temperatures, studies over small geographic scales allowing investigations on the effects of gene flow are of great value for understanding thermal adaptation. Here, we investigated genetic population structure in the freshwater gastropod Radix balthica originating from contrasting thermal habitats in three areas of geothermal activity in Iceland. Snails from 32 sites were genotyped at 208 AFLP loci. Five AFLPs were identified as putatively under divergent selection in Lake Mývatn, a geothermal lake with an almost 20 °C difference in mean temperature across a distance of a few kilometres. In four of these loci, variation across all study populations was correlated with temperature. We found significant population structure in neutral markers both within and between the areas. Cluster analysis using neutral markers classified the sites mainly by geography, whereas analyses using markers under selection differentiated the sites based on temperature. Isolation by distance was stronger in the neutral than in the outlier loci. Pairwise differences based on outlier FST were significantly correlated with temperature at different spatial scales, even after correcting for geographic distance or neutral pairwise FST differences. In general, genetic variation decreased with increasing environmental temperature, possibly suggesting that natural selection had reduced the genetic diversity in the warm origin sites. Our results emphasize the influence of environmental temperature on the genetic structure of populations and suggest local thermal adaptation in these geothermal habitats. PMID:27208484

  1. High temperature thermal destruction of shipboard solid wastes in the 21. century environment

    SciTech Connect

    Gupta, A.K.; Keating, E.L.; Gill, S.

    1996-09-01

    Discharging solid wastes generated aboard marine vessels into US and international waters is facing increased prohibition and restriction by law. One of the more significant actions today for the US Navy is their need to meet the zero discharge requirement of MARPOL ANNEX V in special areas. The amount of solid mixed wastes generated on US Navy warships is about 3.14 lbm/person/day, comparable with the municipal solid waste generation rate of about 4 lbm/person/day. The components in the waste can experience both temporal and spatial variations such that the exact composition of shipboard generated waste (and also municipal) is not constant. In this paper both fundamental and applied research efforts on the high temperature thermal destruction of surrogate solid wastes will be described. Results provided in the paper reveal the effect of temperature and heating rate on thermal destruction and product gas composition. Tests are presently underway pursuing various types of nonplastic solid surrogate wastes using parallel experimental and analytical efforts in an effort to optimize the secondary combustion zone for high temperature pyrolysis product gases. Results from these efforts suggest that ultra high temperature thermal destruction can meet most warship criteria.

  2. Modeling thermal environments in large blast/thermal simulator (LB/TS). Technical report, 17 March 1983-28 February 1984

    SciTech Connect

    Chambers, B.S.

    1986-04-30

    This work was conducted in support of the use of aluminum-liquid oxygen (LOX) thermal-radiation simulators (TRS) in the planned large blast/thermal simulator (LB/TS). The type of TRS is the so-called flame or torch TRS. The tasks performed consisted of the following activities: (1) the TRS predictor models were extended to account for different burn rates, (2) conditions unique to the LB/TS were considered from a modeling viewpoint, (3) four camera systems were used to characterize the spectral and temperature variations of a four nozzle TRS, (4) calorimeter baffles were designed, constructed, and used to obtain source-resolved irradiance data. Relationships to scale TRS output to fuel-flow rate were hypothesized and compared to available data. The results are encouraging but inconclusive. With the existence of source-resolved irradiance data, an improvement was made to the TRS predictor models; this improvement has applicability to TRS use in predicting free field environments. The photographic and spectral measurement made in the visible were useful to understanding the TRS flame structure. The baffled calorimeter experiments yielded data directly usable to improve models.

  3. Exploiting Lunar Natural and Augmented Thermal Environments for Exploration and Research

    NASA Technical Reports Server (NTRS)

    Ryan, Robert E.; Underwood, Lauren W.; McKellip, Rodney; Brannon, David P.; Russell, Kristen J.

    2008-01-01

    Near the poles of the Moon, there are permanently shadowed craters whose surface temperatures never exceed 100 K. Craters within craters, commonly referred to as double-shaded craters, have areas where even colder regions exist with, in many cases, temperatures that should never exceed 50 K. The presence of water ice possibly existing in permanently shaded areas of the moon has been hypothesized, discussed, and studied since Watson et al. [1] predicted the possibility of ice on the moon. Ingersoll et al. [2] estimated that the maximum sublimation rate for ice is less than 1 cm per billion years for these types of environments. These potential ice stores have many uses for lunar exploration, potentially providing precious water and rocket fuel for any human exploration or future colonization. The temperatures within these regions offer unprecedented high-vacuum cryogenic environments, which in their natural state could support cryogenic applications such as high-temperature superconductors and associated devices that could be derived. The potential application of naturally occurring cryogenic environments in conjunction with simple methods to augment these environments to achieve even colder temperatures opens the potential use of many additional cryogenic techniques. Besides ice stores and the potential for continuous solar illumination for power production, the unique cryogenic conditions at the lunar poles provide an environment that could reduce the power, weight, and total mass that would have to be carried from the Earth to the Moon for lunar exploration and research.

  4. Thermal Pollution Math Model. Volume 1. Thermal Pollution Model Package Verification and Transfer. [environment impact of thermal discharges from power plants

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.

    1980-01-01

    Two three dimensional, time dependent models, one free surface, the other rigid lid, were verified at Anclote Anchorage and Lake Keowee respectively. The first site is a coastal site in northern Florida; the other is a man-made lake in South Carolina. These models describe the dispersion of heated discharges from power plants under the action of ambient conditions. A one dimensional, horizontally-averaged model was also developed and verified at Lake Keowee. The data base consisted of archival in situ measurements and data collected during field missions. The field missions were conducted during winter and summer conditions at each site. Each mission consisted of four infrared scanner flights with supporting ground truth and in situ measurements. At Anclote, special care was taken to characterize the complete tidal cycle. The three dimensional model results compared with IR data for thermal plumes on an average within 1 C root mean square difference. The one dimensional model performed satisfactorily in simulating the 1971-1979 period.

  5. Analogue Materials Measured Under Simulated Lunar and Asteroid Environments: Application to Thermal Infrared Measurements of Airless Bodies

    NASA Astrophysics Data System (ADS)

    Donaldson Hanna, K. L.; Pieters, C. M.; Patterson, W., III; Moriarty, D.

    2012-12-01

    Remote sensing observations provide key insights into the composition and evolution of planetary surfaces. A fundamentally important component to any remote sensing study of planetary surfaces is laboratory measurements of well-characterized samples measured under the appropriate environmental conditions. The near-surface vacuum environment of airless bodies like the Moon and asteroids creates a thermal gradient in the upper hundred microns of regolith. Lab studies of particulate rocks and minerals as well as selected lunar soils under vacuum and lunar-like conditions have identified significant effects of this thermal gradient on thermal infrared (TIR) spectral measurements [e.g. Logan et al. 1973, Salisbury and Walter 1989, Thomas et al. 2010, Donaldson Hanna et al. 2012]. Compared to ambient conditions, these effects include: (1) the Christiansen feature (CF), an emissivity maximum diagnostic of mineralogy and average composition, shifts to higher wavenumbers and (2) an increase in spectral contrast of the CF relative to the Reststrahlen bands (RB), the fundamental molecular vibration bands due to Si-O stretching and bending. Such lab studies demonstrate the high sensitivity of TIR emissivity spectra to environmental conditions under which they are measured. The Asteroid and Lunar Environment Chamber (ALEC) is the newest addition to the RELAB at Brown University. The vacuum chamber simulates the space environment experienced by the near-surface soils of the Moon and asteroids. The internal rotation stage allows for six samples and two blackbodies to be measured without breaking vacuum (<10-4 mbar). Liquid nitrogen is used to cool the interior of the chamber, creating a cold, low emission environment (mimicking the space environment) for heated samples to radiate into. Sample cups can be heated in one of three configurations: (1) from below using heaters embedded in the base of the sample cup, (2) from above using a solar-like radiant heat source, and (3) from

  6. Environment.

    ERIC Educational Resources Information Center

    White, Gilbert F.

    1980-01-01

    Presented are perspectives on the emergence of environmental problems. Six major trends in scientific thinking are identified including: holistic approaches to examining environments, life support systems, resource management, risk assessment, streamlined methods for monitoring environmental change, and emphasis on the global framework. (Author/SA)

  7. Thermal Influence of a Large Green Space on a Hot Urban Environment.

    PubMed

    Sugawara, Hirofumi; Shimizu, Shogo; Takahashi, Hideo; Hagiwara, Shinsuke; Narita, Ken-Ichi; Mikami, Takehiko; Hirano, Tatsuki

    2016-01-01

    City-scale warming is becoming a serious problem in terms of human health. Urban green spaces are expected to act as a countermeasure for urban warming, and therefore better understanding of the micro-climate benefits of urban green is needed. This study quantified the thermal influence of a large green park in Tokyo, Japan on the surrounding urban area by collecting long-term measurements. Apparent variations in the temperature difference between the park and surrounding town were found at both the diurnal and seasonal scales. Advection by regional-scale wind and turbulent mixing transfers colder air from the park to urban areas in its vicinity. The extent of the park's thermal influence on the town was greater on the downwind side of the park (450 m) than on the upwind side (65 m). The extent was also greater in an area where the terrain slopes down toward the town. Even on calm nights, the extent of the thermal influence extended by the park breeze to an average of 200 m from the park boundary. The park breeze was characterized by its divergent flow in a horizontal plane, which was found to develop well in calm conditions late at night (regional scale wind <1.5 m s and after 02:00 LST). The average magnitude of the cooling effect of the park breeze was estimated at 39 Wm. This green space tempered the hot summer nights on a city block scale. These findings can help urban planners in designing a heat-adapted city. PMID:26828168

  8. Thermal biology of the toad Rhinella schneideri in a seminatural environment in southeastern Brazil

    PubMed Central

    Noronha-de-Souza, Carolina R; Bovo, Rafael P; Gargaglioni, Luciane H; Andrade, Denis V; Bícego, Kênia C

    2015-01-01

    The toad, Rhinella schneideri, is a large-bodied anuran amphibian with a broad distribution over South America. R. schneideri is known to be active at night during the warm/rainy months and goes into estivation during the dry/cold months; however, there is no data on the range of body temperatures (Tb) experienced by this toad in the field, and how environmental factors, thermoregulatory behaviors or activity influence them. By using implantable temperature dataloggers, we provide an examination of Tb variation during an entire year under a seminatural setting (emulating its natural habitat) monitored with thermosensors. We also used data on preferred Tb, allowing us to express the effectiveness of thermoregulation quantitatively. Paralleling its cycle of activity, R. schneideri exhibited differences in its daily and seasonal profile of Tb variation. During the active season, toads spent daytime hours in shelters and, therefore, did not explore microhabitats with higher thermal quality, such as open areas in the sun. At nighttime, the thermal suitability of microhabitats shifted as exposed microhabitats experienced greater temperature drops than the more insulated shelter. As toads became active at night, they were driven to the more exposed areas and, as a result, thermoregulatory effectiveness decreased. Our results, therefore, indicate that, during the active season, a compromise between thermoregulation and nocturnal activity may be at play. During the estivation period, R. schneideri spent the entire day cycle inside the shelter. As toads did not engage in nocturnal activity in those areas with low thermal quality, the overall effectiveness of thermoregulation was, indeed, elevated. In conclusion, we showed that daily and seasonal variation in Tb of an anuran species is highly associated with their respective pattern of activity and may involve important physiological and ecological compromises. PMID:27227075

  9. Temperature and human thermal comfort effects of street trees across three contrasting street canyon environments

    NASA Astrophysics Data System (ADS)

    Coutts, Andrew M.; White, Emma C.; Tapper, Nigel J.; Beringer, Jason; Livesley, Stephen J.

    2016-04-01

    Urban street trees provide many environmental, social, and economic benefits for our cities. This research explored the role of street trees in Melbourne, Australia, in cooling the urban microclimate and improving human thermal comfort (HTC). Three east-west (E-W) oriented streets were studied in two contrasting street canyon forms (deep and shallow) and between contrasting tree canopy covers (high and low). These streets were instrumented with multiple microclimate monitoring stations to continuously measure air temperature, humidity, solar radiation, wind speed and mean radiant temperature so as to calculate the Universal Thermal Climate Index (UTCI) from May 2011 to June 2013, focusing on summertime conditions and heat events. Street trees supported average daytime cooling during heat events in the shallow canyon by around 0.2 to 0.6 °C and up to 0.9 °C during mid-morning (9:00-10:00). Maximum daytime cooling reached 1.5 °C in the shallow canyon. The influence of street tree canopies in the deep canyon was masked by the shading effect of the tall buildings. Trees were very effective at reducing daytime UTCI in summer largely through a reduction in mean radiant temperature from shade, lowering thermal stress from very strong (UTCI > 38 °C) down to strong (UTCI > 32 °C). The influence of street trees on canyon air temperature and HTC was highly localized and variable, depending on tree cover, geometry, and prevailing meteorological conditions. The cooling benefit of street tree canopies increases as street canyon geometry shallows and broadens. This should be recognized in the strategic placement, density of planting, and species selection of street trees.

  10. Scientists Trace Adversity's Toll

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2012-01-01

    The stress of a spelling bee or a challenging science project can enhance a student's focus and promote learning. But the stress of a dysfunctional or unstable home life can poison a child's cognitive ability for a lifetime, according to new research. Those studies show that stress forms the link between childhood adversity and poor academic…

  11. Our experience in the evaluation of the thermal comfort during the space flight and in the simulated space environment.

    PubMed

    Novak, L

    1991-01-01

    The paper presents the results of the mathematical modelling the effects of hypogravity on the heat output by the spontaneous convection. The theoretical considerations were completed by the experiments "HEAT EXCHANGE 1" performed on the biosatellite "KOSMOS 936". In the second experiment "HEAT EXCHANGE 2" accomplished on the board of the space laboratory "SALYUT 6" was studied the effect of the microgravity on the thermal state of a man during the space flight. Direct measurement in weightlessness prowed the capacity of the developed electric dynamic katathermometer to check directly the effect of the microgravity on the heat output by the spontaneous convection. The role of the heat partition impairment's in man as by the microgravity, so by the inadequate forced convection are clearly expressed in changes of the skin temperature and the subjective feeling of the cosmonaut's thermal comfort. The experimental extension of the elaborated methods for the flexible adjustment of the thermal environment to the actual physiological needs of man and suggestions for the further investigation are outlined. PMID:11537122

  12. Thermal comfort modelling of body temperature and psychological variations of a human exercising in an outdoor environment

    NASA Astrophysics Data System (ADS)

    Vanos, Jennifer K.; Warland, Jon S.; Gillespie, Terry J.; Kenny, Natasha A.

    2012-01-01

    Human thermal comfort assessments pertaining to exercise while in outdoor environments can improve urban and recreational planning. The current study applied a simple four-segment skin temperature approach to the COMFA (COMfort FormulA) outdoor energy balance model. Comparative results of measured mean skin temperature ( {{bar{T}}}nolimits_{{Msk}} ) with predicted {{bar{T}}}nolimits_{{sk}} indicate that the model accurately predicted {{bar{T}}}nolimits_{{sk}} , showing significantly strong agreement ( r = 0.859, P < 0.01) during outdoor exercise (cycling and running). The combined 5-min mean variation of the {{bar{T}}}nolimits_{{sk}} RMSE was 1.5°C, with separate cycling and running giving RMSE of 1.4°C and 1.6°C, respectively, and no significant difference in residuals. Subjects' actual thermal sensation (ATS) votes displayed significant strong rank correlation with budget scores calculated using both measured and predicted {{bar{T}}}nolimits_{{sk}} ( r s = 0.507 and 0.517, respectively, P < 0.01). These results show improved predictive strength of ATS of subjects as compared to the original and updated COMFA models. This psychological improvement, plus {{bar{T}}}nolimits_{{sk}} and T c validations, enables better application to a variety of outdoor spaces. This model can be used in future research studying linkages between thermal discomfort, subsequent decreases in physical activity, and negative health trends.

  13. By-Pass Diode Temperature Tests of a Solar Array Coupon under Space Thermal Environment Conditions

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon

    2016-01-01

    By-Pass diodes are a key design feature of solar arrays and system design must be robust against local heating, especially with implementation of larger solar cells. By-Pass diode testing was performed to aid thermal model development for use in future array designs that utilize larger cell sizes that result in higher string currents. Testing was performed on a 56-cell Advanced Triple Junction solar array coupon provided by SSL. Test conditions were vacuum with cold array backside using discrete by-pass diode current steps of 0.25 A ranging from 0 A to 2.0 A.

  14. Access Load Balancing with Analogy to Thermal Diffusion for Dynamic P2P File-Sharing Environments

    NASA Astrophysics Data System (ADS)

    Takaoka, Masanori; Uchida, Masato; Ohnishi, Kei; Oie, Yuji

    In this paper, we propose a file replication method to achieve load balancing in terms of write access to storage device (“write storage access load balancing” for short) in unstructured peer-to-peer (P2P) file-sharing networks in which the popularity trend of queried files varies dynamically. The proposed method uses a write storage access ratio as a load balance index value in order to stabilize dynamic P2P file-sharing environments adaptively. In the proposed method, each peer autonomously controls the file replication ratio, which is defined as a probability to create the replica of the file in order to uniform write storage access loads in the similar way to thermal diffusion phenomena. Theoretical analysis results show that the behavior of the proposed method actually has an analogy to a thermal diffusion equation. In addition, simulation results reveal that the proposed method has an ability to realize write storage access load balancing in the dynamic P2P file-sharing environments.

  15. Thermal environment effects on strength and impact properties of boron-aluminum composites

    NASA Technical Reports Server (NTRS)

    Grimes, H. H.; Lad, R. A.; Maisel, J. E.

    1977-01-01

    Thermal effects on fracture strength and impact energy were studied in 50 volume percent unidirectional composites of 143 and 203 micron boron fibers in 6061 and 1100 aluminum matrices. For 6061 matrix composites, strength was maintained to approximately 400 C in the cyclic tests and higher than 400 C in the static tests. For the 1100 matrix composites, strength degradation appeared near 260 C after cycling and higher than 260 C in static heating. This composite strength degradation is explained by a fiber degradation mechanism resulting from a boron-aluminum interface reaction. The impact energy absorption degraded significantly only above 400 C for both matrix alloys. Thus, while impact loss for the 6061 composite correlates with the fiber strength loss, other energy absorption processes appear to extend the impact resistance of the 1100 matrix composites to temperatures beyond where its strength is degraded. Interrupted impact tests on as-received and thermally cycled composites define the range of load over which the fibers break in the impact event.

  16. Thermal denaturation behavior of collagen fibrils in wet and dry environment.

    PubMed

    Suwa, Yosuke; Nam, Kwangwoo; Ozeki, Kazuhide; Kimura, Tsuyoshi; Kishida, Akio; Masuzawa, Toru

    2016-04-01

    We have developed a new minimally invasive technique--integrated low-level energy adhesion technique (ILEAT)--which uses heat, pressure, and low-frequency vibrations for binding living tissues. Because the adhesion mechanism of the living tissues is not fully understood, we investigated the effect of thermal energy on the collagen structure in living tissues using ILEAT. To study the effect of thermal energy and heating time on the structure of the collagen fibril, samples were divided in two categories-wet and dry. Further, atomic force microscopy was used to analyze the collagen fibril structure before and after heating. Results showed that collagen fibrils in water denatured after 1 minute at temperatures higher than 80 °C, while partial denaturation was observed at temperatures of 80 °C and a heating time of 1 min. Furthermore, complete denaturation was achieved after 90 min, suggesting that the denaturation rate is temperature and time dependent. Moreover, the collagen fibrils in dry condition maintained their native structure even after being heated to 120 °C for 90 min in the absence of water, which specifically suppressed denaturation. However, partial denaturation of collagen fibrils could not be prevented, because this determines the adhesion between the collagen molecules, and stabilizes tissue bonding. PMID:25952296

  17. Microbial structures in an Alpine Thermal Spring - Microscopic techniques for the examination of Biofilms in a Subsurface Environment

    NASA Astrophysics Data System (ADS)

    Dornmayr-Pfaffenhuemer, Marion; Pierson, Elisabeth; Janssen, Geert-Jan; Stan-Lotter, Helga

    2010-05-01

    The research into extreme environments hast important implications for biology and other sciences. Many of the organisms found there provide insights into the history of Earth. Life exists in all niches where water is present in liquid form. Isolated environments such as caves and other subsurface locations are of interest for geomicrobiological studies. And because of their "extra-terrestrial" conditions such as darkness and mostly extreme physicochemical state they are also of astrobiological interest. The slightly radioactive thermal spring at Bad Gastein (Austria) was therefore examined for the occurrence of subsurface microbial communities. The surfaces of the submerged rocks in this warm spring were overgrown by microbial mats. Scanning electron microscopy (SEM) performed by the late Dr. Wolfgang Heinen revealed an interesting morphological diversity in biofilms found in this environment (1, 2). Molecular analysis of the community structure of the radioactive subsurface thermal spring was performed by Weidler et al. (3). The growth of these mats was simulated using sterile glass slides which were exposed to the water stream of the spring. Those mats were analysed microscopically. Staining, using fluorescent dyes such as 4',6-Diamidino-2-phenylindol (DAPI), gave an overview of the microbial diversity of these biofilms. Additional SEM samples were prepared using different fixation protocols. Scanning confocal laser microscopy (SCLM) allowed a three dimensional view of the analysed biofilms. This work presents some electron micrographs of Dr. Heinen and additionally new microscopic studies of the biofilms formed on the glass slides. The appearances of the new SEM micrographs were compared to those of Dr. Heinen that were done several years ago. The morphology and small-scale distribution in the microbial mat was analyzed by fluorescence microscopy. The examination of natural biomats and biofilms grown on glass slides using several microscopical techniques

  18. Post-flight Analysis of Mars Science Laboratory Entry Aerothermal Environment and Thermal Protection System Response

    NASA Technical Reports Server (NTRS)

    White, Todd Richard; Mahazari, Milad; Bose, Deepak; Santos, Jose Antonio

    2013-01-01

    The Mars Science Laboratory successfully landed on the Martian surface on August 5th, 2012. The rover was protected from the extreme heating environments of atmospheric entry by an ablative heatshield. This Phenolic Impregnated Carbon Ablator heatshield was instrumented with a suite of embedded thermocouples, isotherm sensors, and pressure transducers. The sensors monitored the in-depth ablator response, as well as the surface pressure at discrete locations throughout the hypersonic deceleration. This paper presents a comparison of the flight data with post-entry estimates. An assessment of the aerothermal environments, as well as the in-depth response of the heatshield material is made, and conclusions regarding the overall performance of the ablator at the suite locations are presented.

  19. The Prevalence of STIV c92-Like Proteins in Acidic Thermal Environments.

    PubMed

    Snyder, Jamie C; Bolduc, Benjamin; Bateson, Mary M; Young, Mark J

    2011-01-01

    A new type of viral-induced lysis system has recently been discovered for two unrelated archaeal viruses, STIV and SIRV2. Prior to the lysis of the infected host cell, unique pyramid-like lysis structures are formed on the cell surface by the protrusion of the underlying cell membrane through the overlying external S-layer. It is through these pyramid structures that assembled virions are released during lysis. The STIV viral protein c92 is responsible for the formation of these lysis structures. We searched for c92-like proteins in viral sequences present in multiple viral and cellular metagenomic libraries from Yellowstone National Park acidic hot spring environments. Phylogenetic analysis of these proteins demonstrates that, although c92-like proteins are detected in these environments, some are quite divergent and may represent new viral families. We hypothesize that this new viral lysis system is common within diverse archaeal viral populations found within acidic hot springs. PMID:22312348

  20. By-Pass Diode Temperature Tests of a Solar Array Coupon Under Space Thermal Environment Conditions

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie

    2016-01-01

    Tests were performed on a 56-cell Advanced Triple Junction solar array coupon whose purpose was to determine margin available for bypass diodes integrated with new, large multi-junction solar cells that are manufactured from a 4-inch wafer. The tests were performed under high vacuum with cold and ambient coupon back-side. The bypass diodes were subjected to a sequence of increasing discrete current steps from 0 Amp to 2.0 Amp in steps of 0.25 Amp. At each current step, a temperature measurement was obtained via remote viewing by an infrared camera. This paper discusses the experimental methodology, including the calibration of the thermal imaging system, and the results.

  1. Operation of a Thin-Film Inflatable Concentrator System Demonstrated in a Solar Thermal Vacuum Environment

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2002-01-01

    Thin-film inflatable solar concentrators offer significant advantages in comparison to stateof- the-art rigid panel concentrators, including low weight, low stowage volume, and simple gas deployment. From June 10 to 22, 2001, the ElectroMagnetic Radiation Control Experiment (EMRCE) Team used simulated solar energy to demonstrate the operation of an inflatable concentrator system at NASA Glenn Research Center's Tank 6 thermal vacuum facility. The joint Government/industry test team was composed of engineers and technicians from Glenn, the Air Force Research Laboratory, SRS Technologies, and ATK Thiokol Propulsion. The research hardware consisted of the following: 1) A thin-film inflatable concentrator; 2) The hexapod pointing and focus control system; 3) Two rigidized support struts using two candidate technologies - ultraviolet-rigidized glass and radiation-cured isographite.

  2. Chemical reactions induced by oscillating external fields in weak thermal environments.

    PubMed

    Craven, Galen T; Bartsch, Thomas; Hernandez, Rigoberto

    2015-02-21

    Chemical reaction rates must increasingly be determined in systems that evolve under the control of external stimuli. In these systems, when a reactant population is induced to cross an energy barrier through forcing from a temporally varying external field, the transition state that the reaction must pass through during the transformation from reactant to product is no longer a fixed geometric structure, but is instead time-dependent. For a periodically forced model reaction, we develop a recrossing-free dividing surface that is attached to a transition state trajectory [T. Bartsch, R. Hernandez, and T. Uzer, Phys. Rev. Lett. 95, 058301 (2005)]. We have previously shown that for single-mode sinusoidal driving, the stability of the time-varying transition state directly determines the reaction rate [G. T. Craven, T. Bartsch, and R. Hernandez, J. Chem. Phys. 141, 041106 (2014)]. Here, we extend our previous work to the case of multi-mode driving waveforms. Excellent agreement is observed between the rates predicted by stability analysis and rates obtained through numerical calculation of the reactive flux. We also show that the optimal dividing surface and the resulting reaction rate for a reactive system driven by weak thermal noise can be approximated well using the transition state geometry of the underlying deterministic system. This agreement persists as long as the thermal driving strength is less than the order of that of the periodic driving. The power of this result is its simplicity. The surprising accuracy of the time-dependent noise-free geometry for obtaining transition state theory rates in chemical reactions driven by periodic fields reveals the dynamics without requiring the cost of brute-force calculations. PMID:25702003

  3. Chemical reactions induced by oscillating external fields in weak thermal environments

    NASA Astrophysics Data System (ADS)

    Craven, Galen T.; Bartsch, Thomas; Hernandez, Rigoberto

    2015-02-01

    Chemical reaction rates must increasingly be determined in systems that evolve under the control of external stimuli. In these systems, when a reactant population is induced to cross an energy barrier through forcing from a temporally varying external field, the transition state that the reaction must pass through during the transformation from reactant to product is no longer a fixed geometric structure, but is instead time-dependent. For a periodically forced model reaction, we develop a recrossing-free dividing surface that is attached to a transition state trajectory [T. Bartsch, R. Hernandez, and T. Uzer, Phys. Rev. Lett. 95, 058301 (2005)]. We have previously shown that for single-mode sinusoidal driving, the stability of the time-varying transition state directly determines the reaction rate [G. T. Craven, T. Bartsch, and R. Hernandez, J. Chem. Phys. 141, 041106 (2014)]. Here, we extend our previous work to the case of multi-mode driving waveforms. Excellent agreement is observed between the rates predicted by stability analysis and rates obtained through numerical calculation of the reactive flux. We also show that the optimal dividing surface and the resulting reaction rate for a reactive system driven by weak thermal noise can be approximated well using the transition state geometry of the underlying deterministic system. This agreement persists as long as the thermal driving strength is less than the order of that of the periodic driving. The power of this result is its simplicity. The surprising accuracy of the time-dependent noise-free geometry for obtaining transition state theory rates in chemical reactions driven by periodic fields reveals the dynamics without requiring the cost of brute-force calculations.

  4. Thermal State Of Permafrost In Urban Environment Under Changing Climatic Conditions

    NASA Astrophysics Data System (ADS)

    Streletskiy, D. A.; Grebenets, V. I.; Kerimov, A. G.; Kurchatova, A.; Andruschenko, F.; Gubanov, A.

    2015-12-01

    Risks and damage, caused by deformation of building and constructions in cryolithozone, are growing for decades. Worsening of cryo-ecological situation and loss of engineering-geocryological safety are induced by both technogenic influences on frozen basement and climate change. In such towns on permafrost as Vorkuta, Dixon more than 60% of objects are deformed, in Yakutsk, Igarka- nearly 40%, in Norilsk, Talnakh, Mirnij 35%, in old indigenous villages - approximately 100%; more than 80% ground dams with frozen cores are in poor condition. This situation is accompanied by activation of dangerous cryogenic processes. For example in growing seasonally-thaw layer is strengthening frost heave of pipeline foundation: only on Yamburg gas condensate field (Taz Peninsula) are damaged by frost heave and cut or completely replaced 3000 - 5000 foundations of gas pipelines. Intensity of negative effects strongly depends on regional geocryology, technogenic loads and climatic trends, and in Arctic we see a temperature rise - warming, which cause permafrost temperature rise and thaw). In built areas heat loads are more diverse: cold foundations (under the buildings with ventilated cellars or near termosyphons) are close to warm areas with technogenic beddings (mainly sandy), that accumulate heat, close to underground collectors for communications, growing thaw zones around, close to storages of snows, etc. Note that towns create specific microclimate with higher air temperature. So towns are powerful technogenic (basically, thermal) presses, placed on permafrost; in cooperation with climate changes (air temperature rise, increase of precipitation) they cause permafrost degradation. The analysis of dozens of urban thermal fields, formed in variable cryological and soil conditions, showed, that nearly 70% have warming trend, 20% - cooling and in 10% of cases the situation after construction is stable. Triggered by warming of climate changes of vegetation, depth and temperature of

  5. Formation of Biogenic Fe-Oxyhydroxides in an Extreme Thermal Environment

    NASA Astrophysics Data System (ADS)

    Peng, X.; Chen, S.; Xu, H.

    2014-12-01

    Biogenic Fe-oxyhydroxides have been widely found in freshwater and marine environments. Many studies have suggested a microbial role in iron precipitation in these settings, through either direct metabolic activities of bacteria or passive sorption and nucleation reaction. Due to the complex origin of biogenic Fe-oxyhydroxides, however, it is still a great challenge to ascertain the exact role of microorganisms in the formation of biogenic Fe-oxyhydroxides in nature environments, especially in Fe-rich neutral pH environments. Here, we report the geomicrobiological characterization of Fe-rich reddish precipitates from a high Fe, near-neutral pH hot spring with a temperature of 42 to 73°C located in the Rehai Geothermal Field, Tengchong, China. Abundant sheath-like Fe-oxyhydroxides, which are composed largely of Fe, Si, O and other trace elements, are scattered in the reddish precipitates and exhibit a diversity of morphologies and sizes. The sheath-like Fe-oxyhydroxides consist of ferrihydrites rather than more crystalline Fe oxides. Molecular evidences show that no chemolithotrophic Fe oxidizers were identified. Various thermophiles, mainly including cyanobacteria, Planctomycetes, β-proteobacteria, Deinococci-Thermus and Chlorobi, may be involved in the formation of the sheath-like Fe-oxyhydroxides, through simply acting as binding and nucleation surface for Fe-oxyhydroxides. The oxygen produced by cyanobacteria that dominate the microbial community may greatly accelerate the oxidization of Fe(II) in the spring. Biogenic sheath-like Fe-oxyhydroxides in such a hot, near-neutral pH, Fe-rich spring have important implications for geochemical cycles driven by microorganisms, the origin of microfossils and the formation of banded iron formations (BIFs) in the Archean ocean.

  6. Galileo probe thermal protection: Entry heating environments and spallation experiments design

    NASA Technical Reports Server (NTRS)

    Balakrishnan, A.; Nicolet, W.; Sandhu, S.; Dodson, J.

    1979-01-01

    A valid procedure was developed for predicting wall heating and ablation rates about the probe forebody. Entropy layer effects on convective heating rate were analyzed and the computed results are given. A feasibility study to perform an experiment, the selection of a candidate test facility, and the definition of a test matrix are described. The material selection, fabrication, and evaluation of the metal containing carbon-carbon composites for use on the Galileo probe are summarized. The effect of various Jovian atmospheric models on entry heating environment is considered as well as the effect of the nonspherical shape of the planet on entry trajectory.

  7. Modeling of gaseous reacting flow and thermal environment of liquid rocket injectors

    NASA Astrophysics Data System (ADS)

    Sozer, Emre

    Reacting flow and thermal fields around the injector critically affect the performance and life of liquid rocket engines. The performance gain by enhanced mixing is often countered by increased heat flux to the chamber wall, which can result in material failure. A CFD based design approach can aid in optimization of competing objectives by providing detailed flow field data and an ability to feasibly evaluate a large number of design configurations. To address issues related to the CFD analysis of such flows, various turbulence and combustion modeling aspects are assessed. Laminar finite-rate chemistry and steady laminar flamelet combustion models are adopted to facilitate individual assessments of turbulence-chemistry interactions (TCI) and chemical non-equilibrium. Besides the experimental wall heat transfer information, assessments are aided by evaluations of time scales, grid sensitivity, wall treatments and kinetic schemes. Several multi-element injector configurations are considered to study element-to-element interactions. Under the conditions considered, chemical non-equilibrium effect is found to be unimportant. TCI is found to noticeably alter the flow and thermal fields near the injector and the flame surface. In the multi-element injector case, due to proximity of the outer row injector elements to the wall, wall heat flux distribution is also significantly affected by TCI. The near wall treatment is found to critically affect wall heat flux predictions. A zonal treatment, blending the low-Reynolds number model and the law-of-the-wall approach is shown to improve the accuracy significantly. Porous materials such as Rigimesh are often used as the injector face plate of liquid rocket engines. A multi-scale model which eliminates the empirical dependence of conventional analysis methods, is developed. The resulting model is tested using experimental information showing excellent agreement. The model development and assessment presented for both injector

  8. Helping Student Teachers Avoid Adverse Legal Actions.

    ERIC Educational Resources Information Center

    Peach, Larry; Reddick, Thomas L.

    1984-01-01

    Discusses five areas of the school environment lending themselves to the possibility of teacher and student teacher liability: negligence, malpractice, rights to privacy, field trips, and search of students and school property. Suggests specific guidelines for decreasing the possibility of adverse legal action. (NEC)

  9. Observations of the thermal environment on Red Sea platform reefs: a heat budget analysis

    NASA Astrophysics Data System (ADS)

    Davis, K. A.; Lentz, S. J.; Pineda, J.; Farrar, J. T.; Starczak, V. R.; Churchill, J. H.

    2011-06-01

    Hydrographic measurements were collected on nine offshore reef platforms in the eastern Red Sea shelf region, north of Jeddah, Saudi Arabia. The data were analyzed for spatial and temporal patterns of temperature variation, and a simple heat budget analysis was performed with the goal of advancing our understanding of the physical processes that control temperature variability on the reef. In 2009 and 2010, temperature variability on Red Sea reef platforms was dominated by diurnal variability. The daily temperature range on the reefs, at times, exceeded 5°C—as large as the annual range of water temperature on the shelf. Additionally, our observations reveal the proximity of distinct thermal microclimates within the bounds of one reef platform. Circulation on the reef flat is largely wave driven. The greatest diurnal variation in water temperature occurs in the center of larger reef flats and on reefs protected from direct wave forcing, while smaller knolls or sites on the edges of the reef flat tend to experience less diurnal temperature variability. We found that both the temporal and spatial variability in water temperature on the reef platforms is well predicted by a heat budget model that includes the transfer of heat at the air-water interface and the advection of heat by currents flowing over the reef. Using this simple model, we predicted the temperature across three different reefs to within 0.4°C on the outer shelf using only information about bathymetry, surface heat flux, and offshore wave conditions.

  10. Effects of the LDEF environment on the Ag/FEP thermal blankets

    NASA Technical Reports Server (NTRS)

    Levadou, Francois; Pippin, H. Gary

    1992-01-01

    This presentation was made by Francois Levadou at the NASA Langley Research Center LDEF materials workshop, November 19-22, 1991. It represents the results to date on the examination of silvered teflon thermal blankets primarily from the Ultra-heavy Cosmic Ray Experiment and also from the blanket from the Park Seed Company experiment. ESA/ESTEC and Boeing conducted a number of independent measurements on the blankets and in particular on the exposed fluorinated ethylene-propylene (FEP) layer of the blankets. Mass loss, thickness, and thickness profile measurements have been used by ESA, Boeing, and NASA LeRC to determine recession and average erosion yield under atomic oxygen exposure. Tensile strength and percent elongation to failure data, surface characterization by ESCA, and SEM images are presented. The Jet Propulsion Laboratory analysis of vacuum radiation effects is also presented. The results obtained by the laboratories mentioned and additional results from the Aerospace Corporation on samples provided by Boeing are quite similar and give confidence in the validity of the data.

  11. Designing experiments on thermal interactions by secondary-school students in a simulated laboratory environment

    NASA Astrophysics Data System (ADS)

    Lefkos, Ioannis; Psillos, Dimitris; Hatzikraniotis, Euripides

    2011-07-01

    Background and purpose: The aim of this study was to explore the effect of investigative activities with manipulations in a virtual laboratory on students' ability to design experiments. Sample Fourteen students in a lower secondary school in Greece attended a teaching sequence on thermal phenomena based on the use of information and communication technology, and specifically of the simulated virtual laboratory 'ThermoLab'. Design and methods A pre-post comparison was applied. Students' design of experiments was rated in eight dimensions; namely, hypothesis forming and verification, selection of variables, initial conditions, device settings, materials and devices used, process and phenomena description. A three-level ranking scheme was employed for the evaluation of students' answers in each dimension. Results A Wilcoxon signed-rank test revealed a statistically significant difference between the students' pre- and post-test scores. Additional analysis by comparing the pre- and post-test scores using the Hake gain showed high gains in all but one dimension, which suggests that this improvement was almost inclusive. Conclusions We consider that our findings support the statement that there was an improvement in students' ability to design experiments.

  12. Thermal/Mechanical Durability of Polymer-Matrix Composites in Cryogenic Environments

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Whitley, Karen S.; Grenoble, Ray W.; Bandorawalla, Tozer

    2003-01-01

    In order to increase the reliability of the next generation of space transportation systems, the mechanical behavior of polymeric-matrix composite (PMC) materials at cryogenic temperatures must be investigated. This paper presents experimental data on the residual mechanical properties of a carbon fiber polymeric composite, IM7/PETI-5 as a function of temperature and aging. Tension modulus and strength were measured at room temperature, -196 C, and -269 C on five different specimens ply lay-ups. Specimens were preconditioned with one set of coupons being isothermally aged for 576 hours at -184 C, in an unloaded state. Another set of corresponding coupons were mounted in constant strain fixtures such that a constant uniaxial strain was applied to the specimens for 576 hours at -184 C. A third set was mechanically cycled in tension at -184 C. The measured properties indicated that temperature, aging, and loading mode can all have significant influence on performance. Moreover, this influence is a strong function of laminate stacking sequence. Thermal-stress calculations based on lamination theory predicted that the transverse tensile ply stresses could be quite high for cryogenic test temperatures. Microscopic examination of the surface morphology showed evidence of degradation along the exposed edges of the material because of aging at cryogenic temperatures. ________________

  13. Phase-dependent exciton transport and energy harvesting from thermal environments

    NASA Astrophysics Data System (ADS)

    Oviedo-Casado, S.; Prior, J.; Chin, A. W.; Rosenbach, R.; Huelga, S. F.; Plenio, M. B.

    2016-02-01

    Non-Markovian effects in the evolution of open quantum systems have recently attracted widespread interest, particularly in the context of assessing the efficiency of energy and charge transfer in nanoscale biomolecular networks and quantum technologies. With the aid of many-body simulation methods, we uncover and analyze an ultrafast environmental process that causes energy relaxation in the reduced system to depend explicitly on the phase relation of the initial-state preparation. Remarkably, for particular phases and system parameters, the net energy flow is uphill, transiently violating the principle of detailed balance, and implying that energy is spontaneously taken up from the environment. A theoretical analysis reveals that nonsecular contributions, significant only within the environmental correlation time, underlie this effect. This suggests that environmental energy harvesting will be observable across a wide range of coupled quantum systems.

  14. Importance of dispersal and thermal environment for mycorrhizal communities: lessons from Yellowstone National Park.

    PubMed

    Lekberg, Ylva; Meadow, James; Rohr, Jason R; Redecker, Dirk; Zabinski, Catherine A

    2011-06-01

    The relative importance of dispersal and niche restrictions remains a controversial topic in community ecology, especially for microorganisms that are often assumed to be ubiquitous. We investigated the impact of these factors for the community assembly of the root-symbiont arbuscular mycorrhizal fungi (AMF) by sampling roots from geothermal and nonthermal grasslands in Yellowstone National Park (YNP), followed by sequencing and RFLP of AMF ribosomal DNA. With the exception of an apparent generalist RFLP type closely related to Glomus intraradices, a distance-based redundancy analysis indicated that the AMF community composition correlated with soil pH or pH-driven changes in soil chemistry. This was unexpected, given the large differences in soil temperature and plant community composition between the geothermal and nonthermal grasslands. RFLP types were found in either the acidic geothermal grasslands or in the neutral to alkaline grasslands, one of which was geothermal. The direct effect of the soil chemical environment on the distribution of two AMF morphospecies isolated from acidic geothermal grasslands was supported in a controlled greenhouse experiment. Paraglomus occultum and Scutellospora pellucida were more beneficial to plants and formed significantly more spores when grown in acidic than in alkaline soil. Distance among grasslands, used as an estimate of dispersal limitations, was not a significant predictor of AMF community similarity within YNP, and most fungal taxa may be part of a metacommunity. The isolation of several viable AMF taxa from bison feces indicates that wide-ranging bison could be a vector for at least some RFLP types among grasslands within YNP. In support of classical niche theory and the Baas-Becking hypothesis, our results suggest that AMF are not limited by dispersal at the scale of YNP, but that the soil environment appears to be the primary factor affecting community composition and distribution. PMID:21797157

  15. High temperature oxidation of HFPD thermal-sprayed MCrAlY coatings in simulated gas turbine environments

    NASA Astrophysics Data System (ADS)

    Belzunce, F. J.; Higuera, V.; Poveda, S.; Carriles, A.

    2002-12-01

    NiCrAlY and CoNiCrAlY powders were thermal-sprayed using the high frequency pulse detonation method (HFPD) onto AISI 310 austenitic stainless steel samples to obtain dense, adherent, high temperature oxidation resistant coatings. The oxidation behavior of both types of coatings in a 1000°C simulated gas turbine environment was experimentally determined. The porosity, hardness, coating thickness, and microstructure were not significantly modified by the high temperature oxidation cycles, but the internal oxidation increases significantly after a very low oxidation time. Surface phase composition was evaluated using x-ray diffraction (XRD) and scanning electron microscope (SEM) techniques, revealing the formation of a continuous and highly protective alumina layer. The oxidation kinetics of both coatings can be characterized by parabolic rate constants, which are very close to those for the formation of aluminum oxide on nickel or cobalt based alloys at similar conditions.

  16. Preliminary results of thermal igniter experiments in H/sub 2/-air-steam environments. [PWR; BWR

    SciTech Connect

    Lowry, W.

    1981-01-01

    Thermal igniters (glow plugs), proposed by the Tennessee Valley Authority for intentional ignition of hydrogen in nuclear reactor containment, have been tested for functionability in mixtures of air, hydrogen, and steam. Test environments included 6% to 16% hydrogen concentrations in air, and 8%, 10%, and 12% hydrogen in mixtures with 30% and 40% steam fractions. All were conducted in a 10.6 ft/sup 3/ insulated pressure vessel. For all of these tests the glow plug successfully initiated combustion. Dry air/hydrogen tests exhibited a distinct tendency for complete combustion at hydrogen concentrations between 8% and 9%. Steam suppressed both peak pressures and completeness of combustion. No combustion could be initiated at or above a 50% steam fraction. Circulation of the mixture with a fan increased the completeness of combustion. The glow plug showed no evidence of performance degradation throughout the program.

  17. Index of thermal stress for cows (ITSC) under high solar radiation in tropical environments

    NASA Astrophysics Data System (ADS)

    Da Silva, Roberto Gomes; Maia, Alex Sandro C.; de Macedo Costa, Leonardo Lelis

    2015-05-01

    This paper presents a new thermal stress index for dairy cows in inter-tropical regions, with special mention to the semi-arid ones. Holstein cows were measured for rectal temperature ( T R), respiratory rate ( F R) and rates of heat exchange by convection ( C), radiation ( R), skin surface evaporation ( E S) and respiratory evaporation ( E R) in the north eastern region of Brazil, after exposure to sun for several hours. Average environmental measurements during the observations were air temperature ( T A) 32.4 °C (24.4-38.9°), wind speed ( U) 1.8 m.s-1 (0.01-11.0), relative humidity 63.6 % (36.8-81.5) and short-wave solar radiation 701.3 W m-2 (116-1,295). The effective radiant heat load (ERHL) was 838.5 ± 4.9 W m-2. Values for the atmospheric transmittance ( τ) were also determined for tropical regions, in order to permit adequate estimates of the solar radiation. The average value was τ = 0.611 ± 0.004 for clear days with some small moving clouds, with a range of 0.32 to 0.91 in the day period from 1000 to 1300 hours. Observed τ values were higher (0.62-0.66) for locations near the seacoast and in those regions well-provided with green fields. Effects of month, location and time of the day were all statistically significant ( P < 0.01). A total of 1,092 data were obtained for cows exposed for 1 to 8 h to sun during the day; in 7 months (February, March, April, July, August, September and November), 4 days per month on the average. A principal component analysis summarised the T R, F R, C, R, E S and E R measurements into just one synthetic variable ( y 1); several indexes were then obtained by multiple regression of y 1 on the four environmental variables and its combinations, by using Origin 8.1 software (OriginLab Corp.). The chosen equation was the index of thermal stress for cows, ITSC = 77.1747 + 4.8327 T A - 34.8189 U + 1.111 U 2 + 118.6981 P V - 14.7956 P V 2 - 0.1059 ERHL with r 2 = 0.812. The correlations of ITSC with T R, F R, C, E S, R and E R

  18. Index of thermal stress for cows (ITSC) under high solar radiation in tropical environments.

    PubMed

    Da Silva, Roberto Gomes; Maia, Alex Sandro C; de Macedo Costa, Leonardo Lelis

    2015-05-01

    This paper presents a new thermal stress index for dairy cows in inter-tropical regions, with special mention to the semi-arid ones. Holstein cows were measured for rectal temperature (T R), respiratory rate (F R) and rates of heat exchange by convection (C), radiation (R), skin surface evaporation (E S) and respiratory evaporation (E R) in the north eastern region of Brazil, after exposure to sun for several hours. Average environmental measurements during the observations were air temperature (T A) 32.4 °C (24.4-38.9°), wind speed (U) 1.8 m.s(-1) (0.01-11.0), relative humidity 63.6 % (36.8-81.5) and short-wave solar radiation 701.3 W m(-2) (116-1,295). The effective radiant heat load (ERHL) was 838.5 ± 4.9 W m(-2). Values for the atmospheric transmittance (τ) were also determined for tropical regions, in order to permit adequate estimates of the solar radiation. The average value was τ = 0.611 ± 0.004 for clear days with some small moving clouds, with a range of 0.32 to 0.91 in the day period from 1000 to 1300 hours. Observed τ values were higher (0.62-0.66) for locations near the seacoast and in those regions well-provided with green fields. Effects of month, location and time of the day were all statistically significant (P < 0.01). A total of 1,092 data were obtained for cows exposed for 1 to 8 h to sun during the day; in 7 months (February, March, April, July, August, September and November), 4 days per month on the average. A principal component analysis summarised the T R, F R, C, R, E S and E R measurements into just one synthetic variable (y 1); several indexes were then obtained by multiple regression of y 1 on the four environmental variables and its combinations, by using Origin 8.1 software (OriginLab Corp.). The chosen equation was the index of thermal stress for cows, ITSC = 77.1747 + 4.8327 T A - 34.8189 U + 1.111 U (2) + 118.6981 P V - 14.7956 P V (2) - 0.1059 ERHL with r (2) = 0.812. The

  19. Multi-alkali photocathode thermal performance analysis of image intensifier based on low-high temperature environment testing conditions

    NASA Astrophysics Data System (ADS)

    Gao, Youtang; Tian, Si; Chang, Benkang; Qiu, Yafeng; Qiao, Jianliang

    2008-03-01

    Low-level-light (LLL) weapon sight measurement technologies based on Low-high temperature environments testing conditions are always concerned by military equipments manufacturers. Because low-high temperature environment, etc. are under loaded function, the electric performance parameter change to make LLL weapon sight, causing the LLL weapon sight can't be worked and used normally while taking aim. Generally believed that many photocathode is n-type and p-type doping of the inner surface layer comprising more photocathode not light sensitive, but also sensitive to temperature. To image intensifier is non-working state at the temperature 70°C +/-2°C test boxes and thermostats time one hour, five minutes to image intensifier into -50°C+/-2°C Test Box temperature one hour, then five minutes again placed 70°C +/-2°C high temperature test box for three cycle question image intensifier restore normal temperature after the test. The experiments show that, when the temperature rises, the heat semiconductor photocathode current density, thermal current rise in the temperature range 0 to 70°C, 4°C temperature is increased, almost twice its current heat. Of course, image intensifier imported the equivalent background illumination will also increase, resulting in night vision systems observed at the scene image contrast and differential rates were lowered, target detection system performance last night caused the decline. A study of the reasons is the photo-cathode materials and fabrication of thermal electron emission standards restricting the ability.

  20. Thermoregulatory response to wearing encapsulated protective clothing during simulated work in various thermal environments.

    PubMed

    Payne, W R; Portier, B; Fairweather, I; Zhou, S; Snow, R

    1994-06-01

    This investigation assessed the thermoregulatory impact of performing simulated tasks normally encountered during chemical accident clean-up while wearing chemical protection clothing under various representative thermal loads. A Drager 500 (D) suit was worn with a self-contained breathing apparatus (SCBA) external to the suit, while both a Trelleborg Trellchem Super Extra (T) and a James North MZ500 (J) suit required the SCBA to be worn inside the suit. The D suit was unventilated, while the T and S suits were ventilated with the subject's exhaled air. The T suit also was ventilated via a 2 L/min flow of air from the SCBA. Subjects were six firefighters. Each simulation lasted for 30 minutes and involved tasks such as drum rolling, drum carrying, walking, and hose dragging. The trials were conducted at 11.3, 17.1, and 23.8 degrees C WBGT. The overall mean peak heart rate was 128.1 +/- 2.80 breaths/min and was elicited while performing lifting tasks. Nonsignificant differences (p > 0.05) were observed for both the average heart rate and sweat rate. Mean skin temperature, mean body temperature, and temperature within the suit cavity were significantly higher when wearing the D suit compared to wearing T or J suits; differences between the T and J suits were nonsignificant. Suit type did not significantly affect rectal temperature, which also failed to exceed the American Council of Governmental Industrial Hygienists' (ACGIH) standard of 38.0 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8017293

  1. Repeatability of gradient ultrahigh pressure liquid chromatography-tandem mass spectrometry methods in instrument-controlled thermal environments.

    PubMed

    Grinias, James P; Wong, Jenny-Marie T; Kennedy, Robert T

    2016-08-26

    The impact of viscous friction on eluent temperature and column efficiency in liquid chromatography is of renewed interest as the need for pressures exceeding 1000bar to use with columns packed with sub-2μm particles has grown. One way the development of axial and radial temperature gradients that arise due to viscous friction can be affected is by the thermal environment the column is placed in. In this study, a new column oven integrated into an ultrahigh pressure liquid chromatograph that enables both still-air and forced-air operating modes is investigated to find the magnitude of the effect of the axial thermal gradient that forms in 2.1×100mm columns packed with sub-2μm particles in these modes. Temperature increases of nearly 30K were observed when the generated power of the column exceeded 25W/m. The impact of the heating due to viscous friction on the repeatability of peak capacity, elution time, and peak area ratio to an internal standard for a gradient UHPLC-MS/MS method to analyze neurotransmitters was found to be limited. This result indicates that high speed UHPLC-MS/MS gradient methods under conditions of high viscous friction may be possible without the negative effects typically observed with isocratic separations under similar conditions. PMID:27457561

  2. Thermal Stability of Hi-Nicalon SiC Fiber in Nitrogen and Silicon Environments

    NASA Technical Reports Server (NTRS)

    Bhatt, R. T.; Garg, A.

    1995-01-01

    The room temperature tensile strength of uncoated and two types of pyrolytic boron nitride coated (PBN and Si-rich PBN) Hi-Nicalon SiC fibers was determined after 1 to 400 hr heat treatments to 1800 C under N2 pressures of 0.1, 2, and 4 MPa, and under 0.1 Mpa argon and vacuum environments. In addition, strength stability of both uncoated and coated fibers embedded in silicon powder and exposed to 0.1 MPa N2 for 24 hrs at temperatures to 1400 C was investigated. The uncoated and both types of BN coated fibers exposed to N2 for 1 hr showed noticeable strength degradation above 1400 C and 1600 C, respectively. The strength degradation appeared independent of nitrogen pressure, time of heat treatment, and surface coatings. TEM microstructural analysis suggests that flaws created due to SiC grain growth are responsible for the strength degradation. In contact with silicon powder, the uncoated and both types of PBN coated fibers degrade rapidly above 1350 C.

  3. The effects of simulated low Earth orbit environments on spacecraft thermal control coatings

    NASA Technical Reports Server (NTRS)

    Dever, Joyce A.; Rutledge, Sharon K.; Bruckner, Eric J.; Stidham, Curtis R.; Stueber, Thomas J.; Booth, Roy E.

    1993-01-01

    Candidate Space Station Freedom radiator coatings including Z-93, YB-71, anodized aluminum and SiO(x) coated silvered Teflon have been characterized for optical properties degradation upon exposure to environments containing atomic oxygen, vacuum ultraviolet (VUV) radiation, and/or silicone contamination. YB-71 coating showed a blue-gray discoloration, which has not been observed in space, upon exposure in atomic oxygen facilities which also provide exaggerated VUV radiation. This is evidence that damage mechanisms occur in these ground laboratory facilities which are different from those which occur in space. Radiator coatings exposed to an electron cyclotron resonance (ECR) atomic oxygen source in the presence of silicone-containing samples showed severe darkening from the intense VUV radiation provided by the ECR and from silicone contamination. Samples exposed to atomic oxygen from the ECR source and to VUV lamps, simultaneously, with in situ reflectance measurement, showed that significantly greater degradation occurred when samples received line-of-site ECR beam exposure than when samples were exposed to atomic oxygen scattered off of quartz surfaces without line-of-site view of the ECR beam. For white paints, exposure to air following atomic oxygen/VUV exposure reversed the darkening due to VUV damage. This illustrates the importance of in situ reflectance measurement.

  4. [Adverse reaction of pseudoephedrine].

    PubMed

    López Lois, G; Gómez Carrasco, J A; García de Frías, E

    2005-04-01

    We present a case of a 7 years old girl who developed an episode of myoclonic movements and tremors after being medicated with a not well quantified amount of a pseudoephedrine/antihistamine combination. We want to highlight the potential toxicity of pseudoephedrine, usually administered as part of cold-syrup preparations which are used for symptomatic treatment of upper respiratory tract cough and congestion associated with the common cold and allergic rhinitis. Although these products are generally considered to be safe either by physicians and parents, we can't underestimate the potential adverse events and toxic effects that can occur when administering these medications. PMID:15826569

  5. Thermal and chemical stabilization of ethylene/vinyl acetate/vinyl alcohol (EVA-OH) terpolymers under nitroplasticizer environments

    SciTech Connect

    Yang, Dali; Hubbard, Kevin M.; Henderson, Kevin C.; Labouriau, Andrea

    2014-09-17

    Here, we compare the aging behaviors of cross-linked ethylene/vinyl acetate/vinyl alcohol terpolymers, also referred to as EVA-OH, when they are either immersed in nitroplasticizer (NP) liquid or exposed to NP vapor at different temperatures. And while thermogravimetric analysis and differential scanning calorimetry are used to probe the thermal stability of aged NP and polymers, Fourier transform infrared, gel permeation chromatography, ultra-violet/vis, and nuclear magnetic resonance are used to probe their structural changes over the aging process. Our study confirms that NP degrades through C[BOND]N cleavage, and releases HONO molecules at a slightly elevated temperature (<75°C). As these molecules accumulate in the vapor phase, they react among themselves to create an acidic environment. Therefore, these chemical constituents in the NP vapor significantly accelerate the hydrolysis of EVA-OH polymer. When the hydrolysis occurs in both vinyl acetate and urethane groups and the scission at the cross-linker progresses, EVA-OH becomes vulnerable to further degradation in the NP vapor environment. Finally, through the comprehensive characterization, the possible degradation mechanisms of the terpolymers are proposed.

  6. Thermal and chemical stabilization of ethylene/vinyl acetate/vinyl alcohol (EVA-OH) terpolymers under nitroplasticizer environments

    DOE PAGESBeta

    Yang, Dali; Hubbard, Kevin M.; Henderson, Kevin C.; Labouriau, Andrea

    2014-09-17

    Here, we compare the aging behaviors of cross-linked ethylene/vinyl acetate/vinyl alcohol terpolymers, also referred to as EVA-OH, when they are either immersed in nitroplasticizer (NP) liquid or exposed to NP vapor at different temperatures. And while thermogravimetric analysis and differential scanning calorimetry are used to probe the thermal stability of aged NP and polymers, Fourier transform infrared, gel permeation chromatography, ultra-violet/vis, and nuclear magnetic resonance are used to probe their structural changes over the aging process. Our study confirms that NP degrades through C[BOND]N cleavage, and releases HONO molecules at a slightly elevated temperature (<75°C). As these molecules accumulate inmore » the vapor phase, they react among themselves to create an acidic environment. Therefore, these chemical constituents in the NP vapor significantly accelerate the hydrolysis of EVA-OH polymer. When the hydrolysis occurs in both vinyl acetate and urethane groups and the scission at the cross-linker progresses, EVA-OH becomes vulnerable to further degradation in the NP vapor environment. Finally, through the comprehensive characterization, the possible degradation mechanisms of the terpolymers are proposed.« less

  7. Screening for adverse events.

    PubMed

    Karson, A S; Bates, D W

    1999-02-01

    Adverse events (AEs) in medical patients are common, costly, and often preventable. Development of quality improvement programs to decrease the number and impact of AEs demands effective methods for screening for AEs on a routine basis. Here we describe the impact, types, and potential causes of AEs and review various techniques for identifying AEs. We evaluate the use of generic screening criteria in detail and describe a recent study of the sensitivity and specificity of individual generic screening criteria and combinations of these criteria. In general, the most sensitive screens were the least specific and no small sub-set of screens identified a large percentage of adverse events. Combinations of screens that were limited to administrative data were the least expensive, but none were particularly sensitive, although in practice they might be effective since routine screening is currently rarely done. As computer systems increase in sophistication sensitivity will improve. We also discuss recent studies that suggest that programs that screen for and identify AEs can be useful in reducing AE rates. While tools for identifying AEs have strengths and weaknesses, they can play an important role in organizations' quality improvement portfolios. PMID:10468381

  8. 40 CFR 159.184 - Toxic or adverse effect incident reports.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Toxic or adverse effect incident... Information § 159.184 Toxic or adverse effect incident reports. (a) General. Information about incidents... organism suffered a toxic or adverse effect, or may suffer a delayed or chronic adverse effect in...

  9. ISMP Adverse Drug Reactions

    PubMed Central

    2013-01-01

    The purpose of this feature is to heighten awareness of specific adverse drug reactions (ADRs), discuss methods of prevention, and promote reporting of ADRs to the US Food and Drug Administration’s (FDA’s) MedWatch program (800-FDA-1088). If you have reported an interesting, preventable ADR to MedWatch, please consider sharing the account with our readers. Write to Dr. Mancano at ISMP, 200 Lakeside Drive, Suite 200, Horsham, PA 19044 (phone: 215-707-4936; e-mail: mmancano@temple.edu). Your report will be published anonymously unless otherwise requested. This feature is provided by the Institute for Safe Medication Practices (ISMP) in cooperation with the FDA’s MedWatch program and Temple University School of Pharmacy. ISMP is an FDA MedWatch partner. PMID:24421544

  10. [Cutaneous adverse drug reactions].

    PubMed

    Lebrun-Vignes, B; Valeyrie-Allanore, L

    2015-04-01

    Cutaneous adverse drug reactions (CADR) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Exanthematous eruptions, urticaria and vasculitis are the most common forms of CADR. Fixed eruption is uncommon in western countries. Serious reactions (fatal outcome, sequelae) represent 2% of CADR: bullous reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), DRESS (drug reaction with eosinophilia and systemic symptoms or drug-induced hypersensitivity syndrome) and acute generalized exanthematous pustulosis (AGEP). These forms must be quickly diagnosed to guide their management. The main risk factors are immunosuppression, autoimmunity and some HLA alleles in bullous reactions and DRESS. Most systemic drugs may induce cutaneous adverse reactions, especially antibiotics, anticonvulsivants, antineoplastic drugs, non-steroidal anti-inflammatory drugs, allopurinol and contrast media. Pathogenesis includes immediate or delayed immunologic mechanism, usually not related to dose, and pharmacologic/toxic mechanism, commonly dose-dependent or time-dependent. In case of immunologic mechanism, allergologic exploration is possible to clarify drug causality, with a variable sensitivity according to the drug and to the CADR type. It includes epicutaneous patch testing, prick test and intradermal test. However, no in vivo or in vitro test can confirm the drug causality. To determine the cause of the eruption, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis is required, completed with a literature search. A reporting to pharmacovigilance network is essential in case of a serious CADR whatever the suspected drug and in any case if the involved drug is a newly marketed one or unusually related to cutaneous reactions. PMID:25458866

  11. A role for the thermal environment in defining co-stimulation requirements for CD4(+) T cell activation.

    PubMed

    Zynda, Evan R; Grimm, Melissa J; Yuan, Min; Zhong, Lingwen; Mace, Thomas A; Capitano, Maegan; Ostberg, Julie R; Lee, Kelvin P; Pralle, Arnd; Repasky, Elizabeth A

    2015-01-01

    Maintenance of normal core body temperature is vigorously defended by long conserved, neurovascular homeostatic mechanisms that assist in heat dissipation during prolonged, heat generating exercise or exposure to warm environments. Moreover, during febrile episodes, body temperature can be significantly elevated for at least several hours at a time. Thus, as blood cells circulate throughout the body, physiologically relevant variations in surrounding tissue temperature can occur; moreover, shifts in core temperature occur during daily circadian cycles. This study has addressed the fundamental question of whether the threshold of stimulation needed to activate lymphocytes is influenced by temperature increases associated with physiologically relevant increases in temperature. We report that the need for co-stimulation of CD4+ T cells via CD28 ligation for the production of IL-2 is significantly reduced when cells are exposed to fever-range temperature. Moreover, even in the presence of sufficient CD28 ligation, provision of extra heat further increases IL-2 production. Additional in vivo and in vitro data (using both thermal and chemical modulation of membrane fluidity) support the hypothesis that the mechanism by which temperature modulates co-stimulation is linked to increases in membrane fluidity and membrane macromolecular clustering in the plasma membrane. Thermally-regulated changes in plasma membrane organization in response to physiological increases in temperature may assist in the geographical control of lymphocyte activation, i.e., stimulating activation in lymph nodes rather than in cooler surface regions, and further, may temporarily and reversibly enable CD4+ T cells to become more quickly and easily activated during times of infection during fever. PMID:26131730

  12. 40 CFR 350.21 - Adverse health effects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 28 2011-07-01 2011-07-01 false Adverse health effects. 350.21 Section... RIGHT-TO-KNOW INFORMATION: AND TRADE SECRET DISCLOSURES TO HEALTH PROFESSIONALS Trade Secrecy Claims § 350.21 Adverse health effects. The Governor or State emergency response commission shall identify...

  13. 40 CFR 350.21 - Adverse health effects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Adverse health effects. 350.21 Section... RIGHT-TO-KNOW INFORMATION: AND TRADE SECRET DISCLOSURES TO HEALTH PROFESSIONALS Trade Secrecy Claims § 350.21 Adverse health effects. The Governor or State emergency response commission shall identify...

  14. 40 CFR 350.21 - Adverse health effects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 29 2012-07-01 2012-07-01 false Adverse health effects. 350.21 Section... RIGHT-TO-KNOW INFORMATION: AND TRADE SECRET DISCLOSURES TO HEALTH PROFESSIONALS Trade Secrecy Claims § 350.21 Adverse health effects. The Governor or State emergency response commission shall identify...

  15. 40 CFR 350.21 - Adverse health effects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Adverse health effects. 350.21 Section... RIGHT-TO-KNOW INFORMATION: AND TRADE SECRET DISCLOSURES TO HEALTH PROFESSIONALS Trade Secrecy Claims § 350.21 Adverse health effects. The Governor or State emergency response commission shall identify...

  16. 40 CFR 350.21 - Adverse health effects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 28 2014-07-01 2014-07-01 false Adverse health effects. 350.21 Section... RIGHT-TO-KNOW INFORMATION: AND TRADE SECRET DISCLOSURES TO HEALTH PROFESSIONALS Trade Secrecy Claims § 350.21 Adverse health effects. The Governor or State emergency response commission shall identify...

  17. Carbon uptake in low dissolved inorganic carbon environments: the effect of limited carbon availability on photosynthetic organisms in thermal waters

    NASA Astrophysics Data System (ADS)

    Myers, K. D.; Omelon, C. R.; Bennett, P.

    2010-12-01

    Photosynthesis is the primary carbon fixation process in thermal waters below 70°C, but some hydrothermal waters have extremely low dissolved inorganic carbon (DIC), potentially limiting the growth of inorganic carbon fixing organisms such as algae and cyanobacteria. To address the issue of how carbon is assimilated by phototrophs in these environments, we conducted experiments to compare inorganic carbon uptake mechanisms by two phylogenetically distinct organisms collected from geographically distinct carbon limited systems: the neutral pH geothermal waters of El Tatio, Chile, and the acidic geothermal waters of Tantalus Creek in Norris Geyser Basin, Yellowstone National Park. Discharge waters at El Tatio have low total DIC concentrations (2 to 6 ppm) found mainly as HCO3-; this is in contrast to even lower measured DIC values in Tantalus Creek (as low as 0.13 ppm) that, due to a measured pH of 2.5, exists primarily as CO2. Cyanobacteria and algae are innately physiologically plastic, and we are looking to explore the possibility that carbon limitation in these environments is extreme enough to challenge that plasticity and lead to a suite of carbon uptake adaptations. We hypothesize that these microorganisms utilize adaptive modes of Ci uptake that allow them to survive under these limiting conditions. Cyanobacteria (primarily Synechococcus spp.) isolated from El Tatio can utilize either passive CO2 uptake or active HCO3- uptake mechanisms, in contrast to the eukaryotic alga Cyanidium spp. from Tantalus Creek, which is restricted to an energy-dependent CO2 uptake mechanism. To test this hypothesis, we conducted pH drift experiments (Omelon et al., 2008) to examine changes in pH and [DIC] under a range of pH and [DIC] culture conditions. This work provides baseline information upon which we will begin to investigate the effects of low [DIC] on the growth of phototrophs collected from these and other less carbon limited systems.

  18. Influence of a hot and humid environment on thermal transport across the interface between a Ag thin-film line and a substrate

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Noguchi, Kyohei; Saka, Masumi

    2016-04-01

    To evaluate the reliability of Ag thin-film lines for a wide range of applications in electronic devices, knowledge of the thermal transport across the interface between the line and the underlying substrate is of great importance. This is because such thermal transport significantly affects the temperature distribution in the line, the electrical performance of the line and the service life of the device the line is installed on. In this work, we examine the influence of a hot and humid environment on the thermal transport across the interface between a Ag thin-film line and a substrate. By performing a series of current-stressing experiments using the four-point probe method at atmospheric conditions (296 K and 30 RH%) on a Ag thin-film line for different durations of exposure to a hot and humid environment (323 K and 90 RH%), the electrical resistivity was found to increase with the exposure duration. Such an increase is believed to be the result of a decrease in the interfacial thermal conductance, which indicates less thermal transport from the line to the substrate. Moreover, by observing the surface morphology changes in the line and conducting a one-dimensional electro-thermal analysis, such variations can be attributed to the generation and growth of voids within the line, which hinder heat transfer from the line to the substrate through the interface.

  19. Numerical modeling of the thermal and hydrological environment around a nuclear waste package using the equivalent continuum approximation: Horizontal emplacement

    SciTech Connect

    Nitao, J.J.

    1988-05-01

    In support of the investigations for an underground high-level nuclear waste repository at Yucca Mountain, Nevada, we have performed computer simulations of the immediate thermal and hydrological environment around a nuclear waste package. Calculations of this type will be needed for waste package design, performance assessment, and radionuclide transport analyses. Two dimensional computer simulations using a modified version of the TOUGH code were run for an idealized configuration derived from the COVE3 benchmarking effort consisting of a single spent fuel waste package with laterally periodic boundary conditions. The model domain extended downward to the water table and upward to the ground level. Fluid behavior in the rock was modeled using the equivalent continuum approximation. Runs were made with surface water influx rates at the surface set to 0.1, 0.5, and 1.0 mm/yr. A significant amount of code modification and development was needed in order to develop the capability to run these types of problems out to the long time spans required. 26 refs., 59 figs.

  20. Molecular environment and X-ray study of the metal-rich thermal composite supernova remnant Kes 79

    NASA Astrophysics Data System (ADS)

    Zhou, Ping; Chen, Yang; Safi-Harb, Samar; Sun, Ming

    2015-08-01

    Kes 79 is a thermal composite SNR hosting a central compact object (anti-magnetar) and with a transient magnetar in the south. The SNR has an intriguing double radio shell structure and the nature of the centrally-filled X-ray morphology is still unclear. We have performed 13CO 1-0, 12CO 1-0, 12CO 2-1, and 12CO 3-2 study towards this remnant to investigate the molecular environment. SNR Kes 79 is found to be associated with the molecular cloud in LSR velocity 100-120 km/s. The inner radio shell appears to be well confined by a molecular shell at VLSR˜113 km/s. We also revisited the 380 ks XMM-Newton data of Kes 79, which reveals many bright filamentary structures well coincident with 24 um infrared filaments and an X-ray faint halo confined by the outer radio shell. We performed a spatially resolved spectroscopic analysis for the X-ray filaments and the halo emission. We also study the overabundant metal species Mg, Si, S and Ar, and show their asymmetric distribution across the remnant. The broadband observations suggest that the centrally filled X-ray morphology is a projection effect. Finally, we will discuss the progenitor star of Kes 79 based on the molecular line and X-ray properties.

  1. Thermal Environment in Schools.

    ERIC Educational Resources Information Center

    Ontario Dept. of Education, Toronto. School Planning and Building Research Section.

    This publication attempts to provide some basic descriptions of the various systems and components of climate control and to point out some of the factors to be considered in the selection of the mechanical equipment. The principles of heat gain and loss and ventilation as they relate to a comfortable temperature are discussed. Illustrative…

  2. Adverse antibiotic drug interactions.

    PubMed

    Bint, A J; Burtt, I

    1980-07-01

    There is enormous potential for drug interactions in patients who, today, often receive many drugs. Antibiotics are prominent amongst the groups of drugs commonly prescribed. Many interactions take place at the absorption stage. Antacids and antidiarrhoeal preparations, in particular, can delay and reduce the absorption of antibiotics such as tetracyclines and clindamycin, by combining with them in the gastrointestinal tract to form chelates or complexes. Other drugs can affect gastric motility, which in turn often controls the rate at which antibiotics are absorbed. Some broad spectrum antibiotics can alter the bacterial flora of the gut which may be related to malabsorption states. The potentiation of toxic side effects of one drug by another is a common type of interaction. Antibiotics which are implicated in this type of interaction are those which themselves possess some toxicity such as aminoglycosides, some cephalosporins, tetracyclines and colistin. Some of the most important adverse interactions with antibiotics are those which involve other drugs which have a low toxicity/efficacy ratio. These include anticoagulants such as warfarin, anticonvulsants such as phenytoin and phenobarbitone and oral antidiabetic drugs like tolbutamide. Risk of interaction arises when the metabolism of these drugs is inhibited by liver microsomal enzyme inhibitors such as some sulphonamides and chloramphenicol, or is enhanced by enzyme inducers such as rifampicin. PMID:6995091

  3. ADVERSE CUTANEOUS DRUG REACTION

    PubMed Central

    Nayak, Surajit; Acharjya, Basanti

    2008-01-01

    In everyday clinical practice, almost all physicians come across many instances of suspected adverse cutaneous drug reactions (ACDR) in different forms. Although such cutaneous reactions are common, comprehensive information regarding their incidence, severity and ultimate health effects are often not available as many cases go unreported. It is also a fact that in the present world, almost everyday a new drug enters market; therefore, a chance of a new drug reaction manifesting somewhere in some form in any corner of world is unknown or unreported. Although many a times, presentation is too trivial and benign, the early identification of the condition and identifying the culprit drug and omit it at earliest holds the keystone in management and prevention of a more severe drug rash. Therefore, not only the dermatologists, but all practicing physicians should be familiar with these conditions to diagnose them early and to be prepared to handle them adequately. However, we all know it is most challenging and practically difficult when patient is on multiple medicines because of myriad clinical symptoms, poorly understood multiple mechanisms of drug-host interaction, relative paucity of laboratory testing that is available for any definitive and confirmatory drug-specific testing. Therefore, in practice, the diagnosis of ACDR is purely based on clinical judgment. In this discussion, we will be primarily focusing on pathomechanism and approach to reach a diagnosis, which is the vital pillar to manage any case of ACDR. PMID:19967009

  4. Optical properties of thermal control coatings contaminated by MMH/N2O4 5-pound thruster in a vacuum environment with solar simulation.

    NASA Technical Reports Server (NTRS)

    Sommers, R. D.; Raquet, C. A.; Cassidy, J. F.

    1972-01-01

    Cat-a-lac Black and S13G thermal control coatings were exposed to the exhaust of a thrustor in a simulated space environment. Vacuum was maintained at less than 10 microtorr during thrustor firing in the liquid helium cooled facility. The thrustor was fired in a 50-millisecond pulse mode, and the accumulated firing time was 224 seconds. Solar absorptance and thermal emittance of the coatings were measured in-situ at intervals of 300 pulses, using a calorimetric technique. The Cat-a-lac Black coatings showed no change in solar absorptance or thermal emittance. The S13G showed up to 25% increase in solar absorptance but no change in thermal emittance.

  5. Effects of vegetation, structural and human factors on the thermal performance of residences in a semi-arid environment

    NASA Astrophysics Data System (ADS)

    Kliman, Susan Schaefer

    The objectives of the study were to examine and quantify the relationship between vegetation and the thermal performance of residences in a hot arid environment. Also explored were structural and human influences on residential energy consumption. A primary goal was to determine how much energy savings could be realized through strategic planting of vegetation. This study sought to validate previous simulation and modeling studies that documented annual savings of 2--11% on residential cooling loads. Also examined was whether shrubs and grass could provide a benefit similar to that of trees, assessing the importance of evapotranspiration versus shading. An empirical study was conducted using 105 existing homes in the metropolitan area of Tucson, Arizona. Data included construction type, amenities, living habits of occupants, and energy consumption for heating and cooling over a two-year period. These data were analyzed with a combination of bivariate and multivariate analyses to examine direct correlations between specific variables and energy consumption and the relative importance of each variable. These analyses were unable to document any measurable savings in summer cooling loads as a result of vegetation adjacent to the house, and the presence of trees actually increased the winter heating load by 2%. While trees provide important shading benefits, and can reduce the direct solar gain through the windows of a house, analysis demonstrated that structural and human factors were the most important aspects in residential energy consumption. The size of the house is of primary importance. Houses with evaporative cooling consumed significantly less energy than those with air conditioning. Thermostat settings and habits regarding thermostat operation were the most critical human factors. Occupants who adjusted their thermostats a few degrees cooler in winter and warmer in summer realized measurable savings. Occupants who turned their heating and cooling equipment

  6. Two cold-sensitive neurons within one sensillum code for different parameters of the thermal environment in the ant Camponotus rufipes.

    PubMed

    Nagel, Manuel; Kleineidam, Christoph J

    2015-01-01

    Ants show high sensitivity when responding to minute temperature changes and are able to track preferred temperatures with amazing precision. As social insects, they have to detect and cope with thermal fluctuations not only for their individual benefit but also for the developmental benefit of the colony and its brood. In this study we investigate the sensory basis for the fine-tuned, temperature guided behaviors found in ants, specifically what information about their thermal environment they can assess. We describe the dose-response curves of two cold-sensitive neurons, associated with the sensillum coelocapitulum on the antenna of the carpenter ant Camponotus rufipes.One cold-sensitive neuron codes for temperature changes, thus functioning as a thermal flux-detector. Neurons of such type continuously provide the ant with information about temperature transients (TT-neuron). The TT-neurons are able to resolve a relative change of 37% in stimulus intensity (ΔT) and antennal scanning of the thermal environment may aid the ant's ability to use temperature differences for orientation.The second cold-sensitive neuron in the S. coelocapitulum responds to temperature only within a narrow temperature range. A temperature difference of 1.6°C can be resolved by this neuron type. Since the working range matches the preferred temperature range for brood care of Camponotus rufipes, we hypothesize that this temperature sensor can function as a thermal switch to trigger brood care behavior, based on absolute (steady state) temperature. PMID:26388753

  7. Two cold-sensitive neurons within one sensillum code for different parameters of the thermal environment in the ant Camponotus rufipes

    PubMed Central

    Nagel, Manuel; Kleineidam, Christoph J.

    2015-01-01

    Ants show high sensitivity when responding to minute temperature changes and are able to track preferred temperatures with amazing precision. As social insects, they have to detect and cope with thermal fluctuations not only for their individual benefit but also for the developmental benefit of the colony and its brood. In this study we investigate the sensory basis for the fine-tuned, temperature guided behaviors found in ants, specifically what information about their thermal environment they can assess. We describe the dose-response curves of two cold-sensitive neurons, associated with the sensillum coelocapitulum on the antenna of the carpenter ant Camponotus rufipes.One cold-sensitive neuron codes for temperature changes, thus functioning as a thermal flux-detector. Neurons of such type continuously provide the ant with information about temperature transients (TT-neuron). The TT-neurons are able to resolve a relative change of 37% in stimulus intensity (ΔT) and antennal scanning of the thermal environment may aid the ant’s ability to use temperature differences for orientation.The second cold-sensitive neuron in the S. coelocapitulum responds to temperature only within a narrow temperature range. A temperature difference of 1.6°C can be resolved by this neuron type. Since the working range matches the preferred temperature range for brood care of Camponotus rufipes, we hypothesize that this temperature sensor can function as a thermal switch to trigger brood care behavior, based on absolute (steady state) temperature. PMID:26388753

  8. Estimation of soil moisture-thermal infrared emissivity relation in arid and semi-arid environments using satellite observations

    NASA Astrophysics Data System (ADS)

    Grazia Blasi, Maria; Masiello, Guido; Serio, Carmine; Venafra, Sara; Liuzzi, Giuliano; Dini, Luigi

    2016-04-01

    The retrieval of surface parameters is very important for various aspects concerning the climatological and meteorological context. At this purpose surface emissivity represents one of the most important parameters useful for di fferent applications such as the estimation of climate changes and land cover features. It is known that thermal infrared (TIR) emissivity is aff ected by soil moisture, but there are very few works in literature on this issue. This study is aimed to analyze and fi nd a relation between satellite soil moisture data and TIR emissivity focusing on arid and semi-arid environments. These two parameters, together with the land surface temperature, are fundamental for a better understanding of the physical phenomena implied in the soil-atmosphere interactions and the surface energy balance. They are also important in several fi elds of study, such as climatology, meteorology, hydrology and agriculture. In particular, there are several studies stating a correlation between soil moisture and the emissivity at 8-9 μ m in desertic soils, which corresponds to the quartz Reststrahlen, a feature which is typical of sandy soils. We investigated several areas characterized by arid or semi-arid environments, focusing our attention on the Dahra desert (Senegal), and on the Negev desert (Israel). For the Dahra desert we considered both in situ, provided by the International Soil Moisture Network, and satellite soil moisture data, from ASCAT and AMSR-E sensors, for the whole year 2011. In the case of the Negev desert soil moisture data are derived from ASCAT observations and we computed a soil moisture index from a temporal series of SAR data acquired by the Cosmo-SkyMed constellation covering a period of six months, from June 2015 to November 2015. For both cases soil moisture data were related to the retrieved TIR emissivity from the geostationary satellite SEVIRI in three di erent spectral channels, at 8.7 μm, 10.8 μ m and 12 μ m. A Kalman lter

  9. Thermal and Hydrodynamic Environments Mediate Individual and Aggregative Feeding of a Functionally Important Omnivore in Reef Communities

    PubMed Central

    Frey, Desta L.; Gagnon, Patrick

    2015-01-01

    In eastern Canada, the destruction of kelp beds by dense aggregations (fronts) of the omnivorous green sea urchin, Strongylocentrotus droebachiensis, is a key determinant of the structure and dynamics of shallow reef communities. Recent studies suggest that hydrodynamic forces, but not sea temperature, determine the strength of urchin-kelp interactions, which deviates from the tenets of the metabolic theory of ecology (MTE). We tested the hypothesis that water temperature can predict short-term kelp bed destruction by S. droebachiensis in calm hydrodynamic environments. Specifically, we experimentally determined relationships among water temperature, body size, and individual feeding in the absence of waves, as well as among wave velocity, season, and aggregative feeding. We quantified variation in kelp-bed boundary dynamics, sea temperature, and wave height over three months at one subtidal site in Newfoundland to test the validity of thermal tipping ranges and regression equations derived from laboratory results. Consistent with the MTE, individual feeding during early summer (June-July) obeyed a non-linear, size- and temperature-dependent relationship: feeding in large urchins was consistently highest and positively correlated with temperature <12°C and dropped within and above the 12–15°C tipping range. This relationship was more apparent in large than small urchins. Observed and expected rates of kelp loss based on sea temperature and urchin density and size structure at the front were highly correlated and differed by one order of magnitude. The present study speaks to the importance of considering body size and natural variation in sea temperature in studies of urchin-kelp interactions. It provides the first compelling evidence that sea temperature, and not only hydrodynamic forces, can predict kelp bed destruction by urchin fronts in shallow reef communities. Studying urchin-seaweed-predator interactions within the conceptual foundations of the MTE

  10. Future Directions in Childhood Adversity and Youth Psychopathology

    PubMed Central

    McLaughlin, Katie A.

    2016-01-01

    Despite long-standing interest in the influence of adverse early experiences on mental health, systematic scientific inquiry into childhood adversity and developmental outcomes has emerged only recently. Existing research has amply demonstrated that exposure to childhood adversity is associated with elevated risk for multiple forms of youth psychopathology. In contrast, knowledge of developmental mechanisms linking childhood adversity to the onset of psychopathology—and whether those mechanisms are general or specific to particular kinds of adversity—remains cursory. Greater understanding of these pathways and identification of protective factors that buffer children from developmental disruptions following exposure to adversity is essential to guide the development of interventions to prevent the onset of psychopathology following adverse childhood experiences. This article provides recommendations for future research in this area. In particular, use of a consistent definition of childhood adversity, integration of studies of typical development with those focused on childhood adversity, and identification of distinct dimensions of environmental experience that differentially influence development are required to uncover mechanisms that explain how childhood adversity is associated with numerous psychopathology outcomes (i.e., multifinality) and identify moderators that shape divergent trajectories following adverse childhood experiences. A transdiagnostic model that highlights disruptions in emotional processing and poor executive functioning as key mechanisms linking childhood adversity with multiple forms of psychopathology is presented as a starting point in this endeavour. Distinguishing between general and specific mechanisms linking childhood adversity with psychopathology is needed to generate empirically informed interventions to prevent the long-term consequences of adverse early environments on children’s development. PMID:26849071

  11. Evaluating the behaviour of different thermal indices by investigating various outdoor urban environments in the hot dry city of Damascus, Syria

    NASA Astrophysics Data System (ADS)

    Yahia, Moohammed Wasim; Johansson, Erik

    2013-07-01

    Consideration of urban microclimate and thermal comfort is an absolute neccessity in urban development, and a set of guidelines for every type of climate must be elaborated. However, to develop guidelines, thermal comfort ranges need to be defined. The aim of this study was to evaluate the behaviour of different thermal indices by investigating different thermal environments in Damascus during summer and winter. A second aim was to define the lower and upper limits of the thermal comfort range for some of these indices. The study was based on comprehensive micrometeorological measurements combined with questionnaires. It was found that the thermal conditions of different outdoor environments vary considerably. In general, Old Damascus, with its deep canyons, is more comfortable in summer than modern Damascus where there is a lack of shade. Conversely, residential areas and parks in modern Damascus are more comfortable in winter due to more solar access. The neutral temperatures of both the physiologically equivalent temperature (PET) and the outdoor standard effective temperature (OUT_SET*) were found to be lower in summer than in winter. At 80 % acceptability, the study defined the lower comfort limit in winter to 21.0 °C and the upper limit in summer to 31.3 °C for PET. For OUT_SET*, the corresponding lower and upper limits were 27.6 °C and 31.3 °C respectively. OUT_SET* showed a better correlation with the thermal sensation votes than PET. The study also highlighted the influence of culture and traditions on people's clothing as well as the influence of air conditioning on physical adaptation.

  12. Studies of a new class of high electro-thermal performing Polyimide embedded with 3D scaffold in the harsh environment of outer space

    NASA Astrophysics Data System (ADS)

    Loeblein, Manuela; Bolker, Asaf; Tsang, Siu Hon; Atar, Nurit; Uzan-Saguy, Cecile; Verker, Ronen; Gouzman, Irina; Grossman, Eitan; Teo, Edwin Hang Tong

    The polymer class of Polyimides (PIs) has been wide-spread in the use of outer space coatings due to their chemical stability and flexibility. Nevertheless, their poor thermal conductivity and completely electrically insulating characteristics have caused severe limitations, such as thermal management challenges and spacecraft electrostatic charging, which forces the use of additional materials such as brittle ITO in order to completely resist the harsh environment of space. For this reason, we developed a new composite material via infiltration of PI with a 3D scaffold which improves PIs performance and resilience and enables the use of only a single flexible material to protect spacecraft. Here we present a study of this new material based on outer-space environment simulated on ground. It includes an exhaustive range of tests simulating space environments in accordance with European Cooperation for Space Standard (ECSS), which includes atomic oxygen (AO) etching, Gamma-ray exposure and outgassing properties over extended periods of time and under strenuous mechanical bending and thermal annealing cycles. Measurement methods for the harsh environment of space and the obtained results will be presented.

  13. Thermal Pollution Mathematical Model. Volume 3: User's Manual for One-Dimensional Numerical Model for the Seasonal Thermocline. [environment impact of thermal discharges from power plants

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.

    1980-01-01

    A user's manual for a one dimensional thermal model to predict the temperature profiles of a deep body of water for any number of annual cycles is presented. The model is essentially a set of partial differential equations which are solved by finite difference methods using a high speed digital computer. The model features the effects of area change with depth, nonlinear interaction of wind generated turbulence and buoyancy, adsorption of radiative heat flux below the surface, thermal discharges, and the effects of vertical convection caused by discharge. The main assumption in the formulation is horizontal homogeneity. The environmental impact of thermal discharges from power plants is emphasized. Although the model is applicable to most lakes, a specific site (Lake Keowee, S.C.) application is described in detail. The programs are written in FORTRAN 5.

  14. 18 CFR 292.211 - Petition for initial determination on whether a project has a substantial adverse effect on the...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... determination on whether a project has a substantial adverse effect on the environment (AEE petition). 292.211... for initial determination on whether a project has a substantial adverse effect on the environment... that it has no substantial adverse effect on the environment as specified in § 292.208(b)(1). (b)...

  15. 18 CFR 292.211 - Petition for initial determination on whether a project has a substantial adverse effect on the...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... determination on whether a project has a substantial adverse effect on the environment (AEE petition). 292.211... for initial determination on whether a project has a substantial adverse effect on the environment... that it has no substantial adverse effect on the environment as specified in § 292.208(b)(1). (b)...

  16. 18 CFR 292.211 - Petition for initial determination on whether a project has a substantial adverse effect on the...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... determination on whether a project has a substantial adverse effect on the environment (AEE petition). 292.211... for initial determination on whether a project has a substantial adverse effect on the environment... that it has no substantial adverse effect on the environment as specified in § 292.208(b)(1). (b)...

  17. 18 CFR 292.211 - Petition for initial determination on whether a project has a substantial adverse effect on the...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... determination on whether a project has a substantial adverse effect on the environment (AEE petition). 292.211... for initial determination on whether a project has a substantial adverse effect on the environment... that it has no substantial adverse effect on the environment as specified in § 292.208(b)(1). (b)...

  18. Adverse Reactions to Hallucinogenic Drugs.

    ERIC Educational Resources Information Center

    Meyer, Roger E. , Ed.

    This reports a conference of psychologists, psychiatrists, geneticists and others concerned with the biological and psychological effects of lysergic acid diethylamide and other hallucinogenic drugs. Clinical data are presented on adverse drug reactions. The difficulty of determining the causes of adverse reactions is discussed, as are different…

  19. Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study. Appendix B: Liquid rocket booster acoustic and thermal environments

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The ascent thermal environment and propulsion acoustic sources for the Martin-Marietta Corporation designed Liquid Rocket Boosters (LRB) to be used with the Space Shuttle Orbiter and External Tank are described. Two designs were proposed: one using a pump-fed propulsion system and the other using a pressure-fed propulsion system. Both designs use LOX/RP-1 propellants, but differences in performance of the two propulsion systems produce significant differences in the proposed stage geometries, exhaust plumes, and resulting environments. The general characteristics of the two designs which are significant for environmental predictions are described. The methods of analysis and predictions for environments in acoustics, aerodynamic heating, and base heating (from exhaust plume effects) are also described. The acoustic section will compare the proposed exhaust plumes with the current SRB from the standpoint of acoustics and ignition overpressure. The sections on thermal environments will provide details of the LRB heating rates and indications of possible changes in the Orbiter and ET environments as a result of the change from SRBs to LRBs.

  20. Uncertainty analysis of thermocouple measurements used in normal and abnormal thermal environment experiments at Sandia's Radiant Heat Facility and Lurance Canyon Burn Site.

    SciTech Connect

    Nakos, James Thomas

    2004-04-01

    It would not be possible to confidently qualify weapon systems performance or validate computer codes without knowing the uncertainty of the experimental data used. This report provides uncertainty estimates associated with thermocouple data for temperature measurements from two of Sandia's large-scale thermal facilities. These two facilities (the Radiant Heat Facility (RHF) and the Lurance Canyon Burn Site (LCBS)) routinely gather data from normal and abnormal thermal environment experiments. They are managed by Fire Science & Technology Department 09132. Uncertainty analyses were performed for several thermocouple (TC) data acquisition systems (DASs) used at the RHF and LCBS. These analyses apply to Type K, chromel-alumel thermocouples of various types: fiberglass sheathed TC wire, mineral-insulated, metal-sheathed (MIMS) TC assemblies, and are easily extended to other TC materials (e.g., copper-constantan). Several DASs were analyzed: (1) A Hewlett-Packard (HP) 3852A system, and (2) several National Instrument (NI) systems. The uncertainty analyses were performed on the entire system from the TC to the DAS output file. Uncertainty sources include TC mounting errors, ANSI standard calibration uncertainty for Type K TC wire, potential errors due to temperature gradients inside connectors, extension wire uncertainty, DAS hardware uncertainties including noise, common mode rejection ratio, digital voltmeter accuracy, mV to temperature conversion, analog to digital conversion, and other possible sources. Typical results for 'normal' environments (e.g., maximum of 300-400 K) showed the total uncertainty to be about {+-}1% of the reading in absolute temperature. In high temperature or high heat flux ('abnormal') thermal environments, total uncertainties range up to {+-}2-3% of the reading (maximum of 1300 K). The higher uncertainties in abnormal thermal environments are caused by increased errors due to the effects of imperfect TC attachment to the test item. 'Best

  1. Characterization of Textiles Used in Chefs' Uniforms for Protection Against Thermal Hazards Encountered in the Kitchen Environment.

    PubMed

    Zhang, Han; McQueen, Rachel H; Batcheller, Jane C; Ehnes, Briana L; Paskaluk, Stephen A

    2015-10-01

    Within the kitchen the potential for burn injuries arising from contact with hot surfaces, flames, hot liquid, and steam hazards is high. The chef's uniform can potentially offer some protection against such burns by providing a protective barrier between the skin and the thermal hazard, although the extent to which can provide some protection is unknown. The purpose of this study was to examine whether fabrics used in chefs' uniforms were able to provide some protection against thermal hazards encountered in the kitchen. Fabrics from chefs' jackets and aprons were selected. Flammability of single- and multiple-layered fabrics was measured. Effect of jacket type, apron and number of layers on hot surface, hot water, and steam exposure was also measured. Findings showed that all of the jacket and apron fabrics rapidly ignited when exposed to a flame. Thermal protection against hot surfaces increased as layers increased due to more insulation. Protection against steam and hot water improved with an impermeable apron in the system. For wet thermal hazards increasing the number of permeable layers can decrease the level of protection due to stored thermal energy. As the hands and arms are most at risk of burn injury increased insulation and water-impermeable barrier in the sleeves would improve thermal protection with minimal compromise to overall thermal comfort. PMID:25925745

  2. MOLECULAR ENVIRONMENT AND THERMAL X-RAY SPECTROSCOPY OF THE SEMICIRCULAR YOUNG COMPOSITE SUPERNOVA REMNANT 3C 396

    SciTech Connect

    Su Yang; Yang Ji; Lu Dengrong; Yang Chen; Zhou Xin; Koo, Bon-Chul; Jeong, Il-Gyo; DeLaney, Tracey

    2011-01-20

    We have investigated the molecular environment of the semicircular composite supernova remnant (SNR) 3C 396 and performed a Chandra spatially resolved thermal X-ray spectroscopic study of this young SNR. With our CO millimeter observations, we find that the molecular clouds (MCs) at V{sub LSR}{approx} 84 km s{sup -1} can better explain the multiwavelength properties of the remnant than the V{sub LSR} = 67-72 km s{sup -1} MCs that are suggested by Lee et al. At around 84 km s{sup -1}, the western boundary of the SNR is perfectly confined by the western molecular wall. The CO emission fades out from west to east, indicating that the eastern region is of low gas density. In particular, an intruding finger/pillar-like MC, which may be shocked at the tip, can well explain the X-ray and radio enhancement in the southwest and some infrared filaments there. The SNR-MC interaction is also favored by the relatively elevated {sup 12}CO J = 2-1/J = 1-0 line ratios in the southwestern 'pillar tip' and the molecular patch on the northwestern boundary. The redshifted {sup 12}CO (J = 1-0 and J = 2-1) wings (86-90 km s{sup -1}) of an eastern 81 km s{sup -1} molecular patch may be the kinematic evidence for shock-MC interaction. We suggest that the 69 km s{sup -1} MCs are in the foreground based on H I self-absorption while the 84 km s{sup -1} MCs at a distance of 6.2 kpc (the tangent point) are in physical contact with SNR 3C 396. The X-ray spectral analysis suggests an SNR age of {approx}3 kyr. The metal enrichment of the X-ray emitting gas in the north and south implies a 13-15 M{sub sun} B1-B2 progenitor star.

  3. Adverse possession of subsurface minerals

    SciTech Connect

    Bowles, P.N.

    1983-01-01

    Concepts applicable to adverse possession of subsurface minerals are generally the same as those that apply to adverse possession of all real estate. However, special requirements must be satisfied in order to perfect title to subsurface minerals by adverse possession, particularly when there has been a severance of the true title between surface and subsurface minerals. In those jurisdictions where senior and junior grants came from the state or commonwealth covering the same or some of the same land and in those areas where descriptions of land were vague or not carefully drawn, adverse possession serves to solidify land and mineral ownership. There may be some public, social, and economic justification in rewarding, with good title, those who take possession and use real estate for its intended use, including the extraction of subsurface minerals. 96 refernces.

  4. Reverse Engineering Adverse Outcome Pathways

    SciTech Connect

    Perkins, Edward; Chipman, J.K.; Edwards, Stephen; Habib, Tanwir; Falciani, Francesco; Taylor, Ronald C.; Van Aggelen, Graham; Vulpe, Chris; Antczak, Philipp; Loguinov, Alexandre

    2011-01-30

    The toxicological effects of many stressors are mediated through unknown, or poorly characterized, mechanisms of action. We describe the application of reverse engineering complex interaction networks from high dimensional omics data (gene, protein, metabolic, signaling) to characterize adverse outcome pathways (AOPs) for chemicals that disrupt the hypothalamus-pituitary-gonadal endocrine axis in fathead minnows. Gene expression changes in fathead minnow ovaries in response to 7 different chemicals, over different times, doses, and in vivo versus in vitro conditions were captured in a large data set of 868 arrays. We examined potential AOPs of the antiandrogen flutamide using two mutual information theory methods, ARACNE and CLR to infer gene regulatory networks and potential adverse outcome pathways. Representative networks from these studies were used to predict a network path from stressor to adverse outcome as a candidate AOP. The relationship of individual chemicals to an adverse outcome can be determined by following perturbations through the network in response to chemical treatment leading to the nodes associated with the adverse outcome. Identification of candidate pathways allows for formation of testable hypotheses about key biologic processes, biomarkers or alternative endpoints, which could be used to monitor an adverse outcome pathway. Finally, we identify the unique challenges facing the application of this approach in ecotoxicology, and attempt to provide a road map for the utilization of these tools. Key Words: mechanism of action, toxicology, microarray, network inference

  5. Thermal decomposition of HMX: Low temperature reaction kinetics and their use for assessing response in abnormal thermal environments and implications for long-term aging

    SciTech Connect

    Behrens, R.; Bulusu, S.

    1995-12-01

    The thermal decomposition of HMX between 175 and 200{degree}C has been studied using the simultaneous thermogravimetric modulated beam mass spectrometer (STMBMS) apparatus with a focus on the initial stages of the decomposition. The identity of thermal decomposition products is the same as that measured in previous higher temperature experiments. The initial stages of the decomposition are characterized by an induction period followed by two acceleratory periods. The Arrhenius parameters for the induction and two acceleratory periods are (Log(A) = 18.2 {plus_minus} 0.8, Ea = 48.2 {plus_minus} 1.8 kcal/mole), (Log(A) = 17.15 {plus_minus} 1.5 and Ea = 48.9 {plus_minus} 3.2 kcal/mole), (Log A) = 19.1 {plus_minus} 3.0 and Ea = 52.1 {plus_minus} 6.3 kcal/mole), respectively. This data can be used to calculate the time and temperature required to decompose a desired fraction of a sample that is being prepared to test the effect of thermal degradation on its sensitivity or burn rates. It can also be used to estimate the extent of decomposition that may be expected under normal storage conditions for munitions containing HMX. This data, along with previous mechanistic studies conducted at higher temperatures, suggest that the process that controls the early stages of decomposition of HMX in the solid phase is scission of the N-NO{sub 2} bond, reaction of the N0{sub 2} within a ``lattice cage`` to form the mononitroso analogue of HMX and decomposition of the mononitroso HMX within the HMX lattice to form gaseous products that are retained in bubbles or diffuse into the surrounding lattice.

  6. Thermal Pollution Mathematical Model. Volume 5: User's Manual for Three-Dimensional Rigid-Lid Model. [environment impact of thermal discharges from power plants

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.; Sinha, S. K.

    1980-01-01

    A user's manual for a three dimensional, rigid lid model used for hydrothermal predictions of closed basins subjected to a heated discharge together with various other inflows and outflows is presented. The model has the capability to predict (1) wind driven circulation; (2) the circulation caused by inflows and outflows to the domain; and (3) the thermal effects in the domain, and to combine the above processes. The calibration procedure consists of comparing ground truth corrected airborne radiometer data with surface isotherms predicted by the model. The model was verified for accuracy at various sites and results are found to be fairly accurate in all verification runs.

  7. Analysis of Vegetation Within A Semi-Arid Urban Environment Using High Spatial Resolution Airborne Thermal Infrared Remote Sensing Data

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Ridd, Merrill K.

    1998-01-01

    High spatial resolution (5 m) remote sensing data obtained using the airborne Thermal Infrared Multispectral Scanner (TIMS) sensor for daytime and nighttime have been used to measure thermal energy responses for 2 broad classes and 10 subclasses of vegetation typical of the Salt Lake City, Utah urban landscape. Polygons representing discrete areas corresponding to the 10 subclasses of vegetation types have been delineated from the remote sensing data and are used for analysis of upwelling thermal energy for day, night, and the change in response between day and night or flux, as measured by the TIMS. These data have been used to produce three-dimensional graphs of energy responses in W/ sq m for day, night, and flux, for each urban vegetation land cover as measured by each of the six channels of the TIMS sensor. Analysis of these graphs provides a unique perspective for both viewing and understanding thermal responses, as recorded by the TIMS, for selected vegetation types common to Salt Lake City. A descriptive interpretation is given for each of the day, night, and flux graphs along with an analysis of what the patterns mean in reference to the thermal properties of the vegetation types surveyed in this study. From analyses of these graphs, it is apparent that thermal responses for vegetation can be highly varied as a function of the biophysical properties of the vegetation itself, as well as other factors. Moreover, it is also seen where vegetation, particularly trees, has a significant influence on damping or mitigating the amount of thermal radiation upwelling into the atmosphere across the Salt Lake City urban landscape. Published by Elsevier Science Ltd.

  8. Thermal Pollution Mathematical Model. Volume 2: Verification of One-Dimensional Numerical Model at Lake Keowee. [environment impact of thermal discharges from power plants

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.

    1980-01-01

    A one dimensional model for studying the thermal dynamics of cooling lakes was developed and verified. The model is essentially a set of partial differential equations which are solved by finite difference methods. The model includes the effects of variation of area with depth, surface heating due to solar radiation absorbed at the upper layer, and internal heating due to the transmission of solar radiation to the sub-surface layers. The exchange of mechanical energy between the lake and the atmosphere is included through the coupling of thermal diffusivity and wind speed. The effects of discharge and intake by power plants are also included. The numerical model was calibrated by applying it to Cayuga Lake. The model was then verified through a long term simulation using Lake Keowee data base. The comparison between measured and predicted vertical temperature profiles for the nine years is good. The physical limnology of Lake Keowee is presented through a set of graphical representations of the measured data base.

  9. Infrared observations of eclipses of Io, its thermophysical parameters, and the thermal radiation of the Loki volcano and environs

    NASA Technical Reports Server (NTRS)

    Sinton, William M.; Kaminski, Charles

    1988-01-01

    Observations of Io during eclipses by Jupiter in 1981-1984 are reported. Data obtained at 3.45-30 microns using bolometer system No. 1 on the 3-m IRTF telescope at Mauna Kea are presented in extensive tables and graphs and analyzed by means of least-squares fitting of thermophysical models to the eclipse cooling and heating curves, thermal-radiation calculations for the Io volcanoes, and comparison with Voyager data. Best fits are obtained for a model comprising (1) a bright region with a vertically inhomogeneous surface and (2) a dark vertically homogeneous region with thermal inertia only about 0.1 times that of (1). Little evidence of volcanic-flux variability during the period is found, and the majority (but not all) of the excess thermal IR radiation in the sub-Jovian hemisphere is attributed to the Loki volcano and its lava lake.

  10. Infrared observations of eclipses of Io, its thermophysical parameters, and the thermal radiation of the Loki volcano and environs

    SciTech Connect

    Sinton, W.M.; Kaminski, C.

    1988-08-01

    Observations of Io during eclipses by Jupiter in 1981-1984 are reported. Data obtained at 3.45-30 microns using bolometer system No. 1 on the 3-m IRTF telescope at Mauna Kea are presented in extensive tables and graphs and analyzed by means of least-squares fitting of thermophysical models to the eclipse cooling and heating curves, thermal-radiation calculations for the Io volcanoes, and comparison with Voyager data. Best fits are obtained for a model comprising (1) a bright region with a vertically inhomogeneous surface and (2) a dark vertically homogeneous region with thermal inertia only about 0.1 times that of (1). Little evidence of volcanic-flux variability during the period is found, and the majority (but not all) of the excess thermal IR radiation in the sub-Jovian hemisphere is attributed to the Loki volcano and its lava lake. 35 references.

  11. Quantitative model of the effects of contamination and space environment on in-flight aging of thermal coatings

    NASA Astrophysics Data System (ADS)

    Vanhove, Emilie; Roussel, Jean-François; Remaury, Stéphanie; Faye, Delphine; Guigue, Pascale

    2014-09-01

    The in-orbit aging of thermo-optical properties of thermal coatings critically impacts both spacecraft thermal balance and heating power consumption. Nevertheless, in-flight thermal coating aging is generally larger than the one measured on ground and the current knowledge does not allow making reliable predictions1. As a result, a large oversizing of thermal control systems is required. To address this issue, the Centre National d'Etudes Spatiales has developed a low-cost experiment, called THERME, which enables to monitor the in-flight time-evolution of the solar absorptivity of a large variety of coatings, including commonly used coatings and new materials by measuring their temperature. This experiment has been carried out on sunsynchronous spacecrafts for more than 27 years, allowing thus the generation of a very large set of telemetry measurements. The aim of this work was to develop a model able to semi-quantitatively reproduce these data with a restraint number of parameters. The underlying objectives were to better understand the contribution of the different involved phenomena and, later on, to predict the thermal coating aging at end of life. The physical processes modeled include contamination deposition, UV aging of both contamination layers and intrinsic material and atomic oxygen erosion. Efforts were particularly focused on the satellite leading wall as this face is exposed to the highest variations in environmental conditions during the solar cycle. The non-monotonous time-evolution of the solar absorptivity of thermal coatings is shown to be due to a succession of contamination and contaminant erosion by atomic oxygen phased with the solar cycle.

  12. Thermal Radiometer Signal Processing Using Radiation Hard CMOS Application Specific Integrated Circuits for Use in Harsh Planetary Environments

    NASA Technical Reports Server (NTRS)

    Quilligan, G.; DuMonthier, J.; Aslam, S.; Lakew, B.; Kleyner, I.; Katz, R.

    2015-01-01

    Thermal radiometers such as proposed for the Europa Clipper flyby mission require low noise signal processing for thermal imaging with immunity to Total Ionizing Dose (TID) and Single Event Latchup (SEL). Described is a second generation Multi- Channel Digitizer (MCD2G) Application Specific Integrated Circuit (ASIC) that accurately digitizes up to 40 thermopile pixels with greater than 50 Mrad (Si) immunity TID and 174 MeV-sq cm/mg SEL. The MCD2G ASIC uses Radiation Hardened By Design (RHBD) techniques with a 180 nm CMOS process node.

  13. Thermal Radiometer Signal Processing using Radiation Hard CMOS Application Specific Integrated Circuits for use in Harsh Planetary Environments

    NASA Astrophysics Data System (ADS)

    Quilligan, G.; DuMonthier, J.; Aslam, S.; Lakew, B.; Kleyner, I.; Katz, R.

    2015-10-01

    Thermal radiometers such as proposed for the Europa Clipper flyby mission [1] require low noise signal processing for thermal imaging with immunity to Total Ionizing Dose (TID) and Single Event Latchup (SEL). Described is a second generation Multi- Channel Digitizer (MCD2G) Application Specific Integrated Circuit (ASIC) that accurately digitizes up to 40 thermopile pixels with greater than 50 Mrad (Si) immunity TID and 174 MeV-cm2/mg SEL. The MCD2G ASIC uses Radiation Hardened By Design (RHBD) techniques with a 180 nm CMOS process node.

  14. Studying the urban thermal environment under a human-biometeorological point of view: The case of a large coastal metropolitan city, Athens

    NASA Astrophysics Data System (ADS)

    Katavoutas, George; Georgiou, Giorgos K.; Asimakopoulos, Dimosthenis N.

    2015-01-01

    The thermal environment in modern cities has become potentially unfavorable and harmful for its residents, as a result of urbanization and industrialization. Exposure to these extreme thermal conditions increases the heat stress of people in cities considerably. In this context, the present study aims to investigate the urban thermal environment of the large coastal metropolitan city of Athens, in a human-biometeorologically significant way, utilizing the thermo-physiological assessment index PET. The analysis was based on three hour measurements derived from three-year datasets (2006-2009), at 12 monitoring sites located in the urban complex of Athens, on its boundaries and beyond them. The differences of PET values have been investigated in order to attribute urban and exurban thermal characteristics to the considered sites. The frequency and spatial distribution of PET as well as the urban/rural differences of PET have also been analyzed. Finally, a trend analysis has been applied in order to detect possible PET trends by employing long-term recording data (1985-2008). In terms of thermal human-biometeorological conditions, the analysis reveals that among the considered stations, those located inside the urban complex and the industrialized area present urban thermal characteristics, regardless the fact that they are installed either in a park and on a hill or at an open field. The spatial distribution of PET, at 0200 LST, shows a difference of about 3 to 4 °C, on the main axis of the city (SSW-NNE) in the summer period, while the difference exceeds 2.5 °C in the winter period. In general, cooler (less warm) thermal perception is observed at the north/northeast sites of the city as well as at the areas beyond the eastern boundaries of it. The PET differences between urban and rural sites hold a positive sign, except of those at 0500 LST and at 0800 LST. The highest differences are noted at 1400 LST and the most intense of them is noticed in the summer period

  15. Study of Uncertainties of Predicting Space Shuttle Thermal Environment. [impact of heating rate prediction errors on weight of thermal protection system

    NASA Technical Reports Server (NTRS)

    Fehrman, A. L.; Masek, R. V.

    1972-01-01

    Quantitative estimates of the uncertainty in predicting aerodynamic heating rates for a fully reusable space shuttle system are developed and the impact of these uncertainties on Thermal Protection System (TPS) weight are discussed. The study approach consisted of statistical evaluations of the scatter of heating data on shuttle configurations about state-of-the-art heating prediction methods to define the uncertainty in these heating predictions. The uncertainties were then applied as heating rate increments to the nominal predicted heating rate to define the uncertainty in TPS weight. Separate evaluations were made for the booster and orbiter, for trajectories which included boost through reentry and touchdown. For purposes of analysis, the vehicle configuration is divided into areas in which a given prediction method is expected to apply, and separate uncertainty factors and corresponding uncertainty in TPS weight derived for each area.

  16. The Metal-enriched Thermal Composite Supernova Remnant Kesteven 41 (G337.8-0.1) in a Molecular Environment

    NASA Astrophysics Data System (ADS)

    Zhang, Gao-Yuan; Chen, Yang; Su, Yang; Zhou, Xin; Pannuti, Thomas G.; Zhou, Ping

    2015-01-01

    The physical nature of thermal composite supernova remnants (SNRs) remains controversial. We have revisited the archival XMM-Newton and Chandra data of the thermal composite SNR Kesteven 41 (Kes 41 or G337.8-0.1) and performed a millimeter observation toward this source in the 12CO, 13CO, and C18O lines. The X-ray emission, mainly concentrated toward the southwestern part of the SNR, is characterized by distinct S and Ar He-like lines in the spectra. The X-ray spectra can be fitted with an absorbed nonequilibrium ionization collisional plasma model at a temperature of 1.3-2.6 keV and an ionization timescale of 0.1-1.2 × 1012 cm-3 s. The metal species S and Ar are overabundant, with 1.2-2.7 and 1.3-3.8 solar abundances, respectively, which strongly indicate the presence of a substantial ejecta component in the X-ray-emitting plasma of this SNR. Kes 41 is found to be associated with a giant molecular cloud (MC) at a systemic local standard of rest velocity of -50 km s-1 and confined in a cavity delineated by a northern molecular shell, a western concave MC that features a discernible shell, and an H I cloud seen toward the southeast of the SNR. The birth of the SNR in a preexisting molecular cavity implies a mass of >~ 18 M ⊙ for the progenitor if it was not in a binary system. Thermal conduction and cloudlet evaporation seem to be feasible mechanisms to interpret the X-ray thermal composite morphology, and the scenario of gas reheating by the shock reflected from the cavity wall is quantitatively consistent with the observations. An updated list of thermal composite SNRs is also presented in this paper.

  17. THE METAL-ENRICHED THERMAL COMPOSITE SUPERNOVA REMNANT KESTEVEN 41 (G337.8-0.1) IN A MOLECULAR ENVIRONMENT

    SciTech Connect

    Zhang, Gao-Yuan; Chen, Yang; Zhou, Ping; Su, Yang; Zhou, Xin; Pannuti, Thomas G.

    2015-01-20

    The physical nature of thermal composite supernova remnants (SNRs) remains controversial. We have revisited the archival XMM-Newton and Chandra data of the thermal composite SNR Kesteven 41 (Kes 41 or G337.8–0.1) and performed a millimeter observation toward this source in the {sup 12}CO, {sup 13}CO, and C{sup 18}O lines. The X-ray emission, mainly concentrated toward the southwestern part of the SNR, is characterized by distinct S and Ar He-like lines in the spectra. The X-ray spectra can be fitted with an absorbed nonequilibrium ionization collisional plasma model at a temperature of 1.3-2.6 keV and an ionization timescale of 0.1-1.2 × 10{sup 12} cm{sup –3} s. The metal species S and Ar are overabundant, with 1.2-2.7 and 1.3-3.8 solar abundances, respectively, which strongly indicate the presence of a substantial ejecta component in the X-ray-emitting plasma of this SNR. Kes 41 is found to be associated with a giant molecular cloud (MC) at a systemic local standard of rest velocity of –50 km s{sup –1} and confined in a cavity delineated by a northern molecular shell, a western concave MC that features a discernible shell, and an H I cloud seen toward the southeast of the SNR. The birth of the SNR in a preexisting molecular cavity implies a mass of ≳ 18 M {sub ☉} for the progenitor if it was not in a binary system. Thermal conduction and cloudlet evaporation seem to be feasible mechanisms to interpret the X-ray thermal composite morphology, and the scenario of gas reheating by the shock reflected from the cavity wall is quantitatively consistent with the observations. An updated list of thermal composite SNRs is also presented in this paper.

  18. Optical properties of thermal control coating contaminated by MMH/N2O4 5-pound thruster in a vacuum environment with solar simulation

    NASA Technical Reports Server (NTRS)

    Sommers, R. D.; Raquet, C. A.; Cassidy, J. F.

    1972-01-01

    Cat-a-lac Black, and S13G thermal control coatings were exposed to the exhaust of a thruster in a simulated space environment. Vacuum was maintained at less than 10 to the minus 5th power torr during thruster firing in the liquid helium cooled facility. The thruster was fired in a 50-millisecond pulse mode and the accumulated firing time was 224 seconds. Solar absorptance (alpha sub s) and thermal emittance (sigma) of the coatings were measured in-situ at intervals of 300 pulses. A calorimetric technique was used to measure alpha sub s and sigma. The tests, technique, and test results are presented. The Cat-a-lac Black coatings showed no change in alpha sub s or sigma. The S13G showed up to 25 percent increase in alpha sub s but no change in sigma.

  19. A review of modeling issues and analysis methods for the thermal response of cargoes transported in the Safe Secure Trailer subjected to fire environments

    SciTech Connect

    Howell, J.R.; Larsen, M.E.

    1998-05-01

    This paper discusses thermal analysis in support of probabilistic risk assessment (PRA) to predict the heating of cargoes shipped in vehicles like the Safe Secure Trailer. Fire environments contribute very significantly to the risk associated with ground transport of special nuclear materials. The tradeoff between thermal model complexity and the affordable number of scenarios used to represent the hazard space is discussed as it impacts PRA. The relevant heat transfer mechanisms are discussed along with the applicability of methods from the literature for analysis of these mechanisms. Many of the subject`s real problems remain too complex for affordable and rigorous analysis. Available models are generally restricted to idealizations that are quickly obviated by real effects. Approximate treatment methods, striving to produce conservative, realistic estimates are also discussed.

  20. Biologics in dermatology: adverse effects.

    PubMed

    Sehgal, Virendra N; Pandhi, Deepika; Khurana, Ananta

    2015-12-01

    Biologics are a group of drugs that precisely affect certain specific steps in the immune response and are an extremely useful group when used in an appropriate setting. However, their use can often be a double-edged sword. Careful patient selection and thorough knowledge of adverse effects is a key to their successful use in various disorders. The initial enthusiasm has gradually given way to a more cautious approach wherein a balance is sought between clinical usefulness and expected side effects. The adverse effects of the biologics most commonly used in dermatology have been carefully listed for ready reference. The plausible causes of the adverse reactions are succinctly outlined along with their incriminating factor(s). Besides, in brief, the attention has been focused on their management. The content should provide an essential didactic content for educating the practitioner. PMID:26147909

  1. A particle image velocimetry validation database in the inoor environment using a breathing thermal manakin in rotational motion

    EPA Science Inventory

    Determination of indoor exposure levels commonly involves assumptions of fully mixed ventilation conditions. In the effort to determine contaminant levels with efficiency, the nodal approach is common in modeling of the indoor environment. To quantify the transport phenomenon or ...

  2. In hot and cold water: differential life-history traits are key to success in contrasting thermal deep-sea environments.

    PubMed

    Marsh, Leigh; Copley, Jonathan T; Tyler, Paul A; Thatje, Sven

    2015-07-01

    Few species of reptant decapod crustaceans thrive in the cold-stenothermal waters of the Southern Ocean. However, abundant populations of a new species of anomuran crab, Kiwa tyleri, occur at hydrothermal vent fields on the East Scotia Ridge. As a result of local thermal conditions at the vents, these crabs are not restricted by the physiological limits that otherwise exclude reptant decapods south of the polar front. We reveal the adult life history of this species by piecing together variation in microdistribution, body size frequency, sex ratio, and ovarian and embryonic development, which indicates a pattern in the distribution of female Kiwaidae in relation to their reproductive development. High-density 'Kiwa' assemblages observed in close proximity to sources of vent fluids are constrained by the thermal limit of elevated temperatures and the availability of resources for chemosynthetic nutrition. Although adult Kiwaidae depend on epibiotic chemosynthetic bacteria for nutrition, females move offsite after extrusion of their eggs to protect brooding embryos from the chemically harsh, thermally fluctuating vent environment. Consequently, brooding females in the periphery of the vent field are in turn restricted by low-temperature physiological boundaries of the deep-water Southern Ocean environment. Females have a high reproductive investment in few, large, yolky eggs, facilitating full lecithotrophy, with the release of larvae prolonged, and asynchronous. After embryos are released, larvae are reliant on locating isolated active areas of hydrothermal flow in order to settle and survive as chemosynthetic adults. Where the cold water restricts the ability of all adult stages to migrate over long distances, these low temperatures may facilitate the larvae in the location of vent sites by extending the larval development period through hypometabolism. These differential life-history adaptations to contrasting thermal environments lead to a disjunct life history

  3. A simplified analytical solution for thermal response of a one-dimensional, steady state transpiration cooling system in radiative and convective environment

    NASA Technical Reports Server (NTRS)

    Kubota, H.

    1976-01-01

    A simplified analytical method for calculation of thermal response within a transpiration-cooled porous heat shield material in an intense radiative-convective heating environment is presented. The essential assumptions of the radiative and convective transfer processes in the heat shield matrix are the two-temperature approximation and the specified radiative-convective heatings of the front surface. Sample calculations for porous silica with CO2 injection are presented for some typical parameters of mass injection rate, porosity, and material thickness. The effect of these parameters on the cooling system is discussed.

  4. Consequences of experimental cortisol manipulations on the thermal biology of the checkered puffer (Sphoeroides testudineus) in laboratory and field environments.

    PubMed

    Cull, F; Suski, C D; Shultz, A; Danylchuk, A J; O'Connor, C M; Murchie, K J; Cooke, S J

    2015-01-01

    Anthropogenic climate change is altering temperature regimes for coastal marine fishes. However, given that temperature changes will not occur in isolation of other stressors, it is necessary to explore the potential consequences of stress on the thermal tolerances and preferences of tropical marine fish in order to understand the thresholds for survival, and predict the associated coastal ecological consequences. In this study, we used exogenous cortisol injections to investigate the effects of a thermal challenge on checkered puffers (Sphoeroides testudineus) as a secondary stressor. There were no significant differences between control and cortisol-treated fish 48h following cortisol treatment for swimming ability (using a chase to exhaustion protocol), blood glucose concentrations or standard metabolic rate. In the lab, control and cortisol-treated puffers were exposed to ambient (29.1±1.5°C), ambient +5°C (heat shock) and ambient -5°C (cold shock) for 4h and to evaluate the consequences of abrupt temperature change on puff performance and blood physiology. Following cold shock, control fish exhibited increases in cortisol levels and weak 'puff' performance. Conversely, fish dosed with cortisol exhibited consistently high cortisol levels independent of thermal treatment, although there was a trend for an attenuated cortisol response in the cortisol-treated fish to the cold shock treatment. A 20-day complementary field study conducted in the puffer's natural habitat, a tidal creek in Eleuthera, The Bahamas, revealed that cortisol-injected fish selected significantly cooler temperatures, measured using accumulated thermal units, when compared to controls. These results, and particularly the discrepancies between consequences documented in the laboratory and the ecological trends observed in the field, highlight the need to establish the link between laboratory and field data to successfully develop management policies and conservation initiatives with regards

  5. Computer simulation of the thermal environment of large-scale integrated circuits - Computer time-saving techniques.

    NASA Technical Reports Server (NTRS)

    Thompson, R. R.; Blum, H. A.

    1971-01-01

    This paper is concerned with the computer costs for both the steady-state and transient thermal responses of large-scale integrated circuits (LSI) when metal is present within the substrate. For the more cost-sensitive transient case, an extrapolation technique for computer time savings is compared with the accuracy loss in this study. This approach could be useful for design-cost planning.

  6. Thermal Barrier and Protective Coatings to Improve the Durability of a Combustor Under a Pulse Detonation Engine Environment

    NASA Technical Reports Server (NTRS)

    Ghosn, Louis J.; Zhu, Dongming

    2008-01-01

    Pulse detonation engine (PDE) concepts are receiving increasing attention for future aeronautic propulsion applications, due to their potential thermodynamic cycle efficiency and higher thrust to density ratio that lead to the decrease in fuel consumption. But the resulting high gas temperature and pressure fluctuation distributions at high frequency generated with every detonation are viewed to be detrimental to the combustor liner material. Experimental studies on a typical metal combustion material exposed to a laser simulated pulse heating showed extensive surface cracking. Coating of the combustor materials with low thermal conductivity ceramics is shown to protect the metal substrate, reduce the thermal stresses, and hence increase the durability of the PDE combustor liner material. Furthermore, the temperature fluctuation and depth of penetration is observed to decrease with increasing the detonation frequency. A crack propagation rate in the coating is deduced by monitoring the variation of the coating apparent thermal conductivity with time that can be utilized as a health monitoring technique for the coating system under a rapid fluctuating heat flux.

  7. The thermal environment of the fiber glass dome for the new solar telescope at Big Bear Solar Observatory

    NASA Astrophysics Data System (ADS)

    Verdoni, A. P.; Denker, C.; Varsik, J. R.; Shumko, S.; Nenow, J.; Coulter, R.

    2007-09-01

    The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path, the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14 vents house louvers that open and close independently of one another to regulate and direct the passage of air through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order of 5° Celsius inside the dome. In December 2006, a second set of temperature measurements were made using different louver configurations. In this study, we present the results of these measurements along with their integration into the thermal control system (ThCS) and the overall telescope control system (TCS).

  8. Cermet composite thermal spray coatings for erosion and corrosion protection in combustion environments of advanced coal-fired boilers

    SciTech Connect

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1996-05-01

    Research is presently being initiated to determine the optimum ceramic/metal combination in thermally sprayed metal matrix composite coatings for erosion and corrosion resistance in new coal-fired boilers. The research will be accomplished by producing model cermet composites using powder metallurgy and electrodeposition methods in which the effect of ceramic/metal combination for the erosion and corrosion resistance will be determined. These results will provide the basis for determining the optimum hard phase constituents` size and volume percent in thermal spray coatings. Thermal spray coatings will be applied by our industrial sponsor and tested in our erosion and corrosion laboratories. During the last quarter, model Ni-Al{sub 2}O{sub 3} powder cermet composites were produced at Idaho National Engineering Laboratory by the Hot Isostatic Pressing (HIP) technique. The composite samples contained 0, 21, 27, 37, and 45 volume percent of Al{sub 2}O{sub 2} in a nickel matrix with an average size of alumina particles of 12 micrometers. The increase in volume fraction of alumina in the nickel matrix from 0 to 45% led to an increase in hardness of these composites from 85 to 180 HV{sub 1000}. The experimental procedure and preliminary microstructural characterization of Ni-Al{sub 2}O{sub 3} composites are presented in this progress report along with plans for the research in coming year. 3 figs.

  9. Thermal preferences and limits of Triatoma brasiliensis in its natural environment--field observations while host searching.

    PubMed

    Catalá, Silvia; Bezerra, Claudia Mendonça; Diotaiuti, Lileia

    2015-09-01

    The goal of this work was to explore the thermal relationship between foraging Triatoma brasiliensis and its natural habitat during the hottest season in the state of Ceará, Brazil. The thermal profiles were determined using infrared analysis. Although the daily temperature of rock surfaces varied in a wide range, T. brasiliensis selected to walk through areas with temperatures between 31.7-40.5ºC. The temperature of T. brasiliensis body surface ranged from 32.8-34.4ºC, being higher in legs than the abdomen. A strong relationship was found between the temperature of the insect and the temperature of rock crevices where they were hidden (r: 0.96, p < 0.05). The species was active at full sunlight being a clear example of how the light-dark rhythm may be altered, even under predation risk. Our results strongly suggest a thermal borderline for T. brasiliensis foraging activity near 40ºC. The simultaneous determination of insect body and rock temperatures here presented are the only obtained in natural habitats for this or other triatomines. PMID:26517659

  10. 40 CFR 174.71 - Submission of information regarding adverse effects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Pesticide Programs' Document Processing Desk at the appropriate address as set forth in 40 CFR 150.17(a) or... any information regarding adverse effects on human health or the environment alleged to have been... information. (b) Adverse effects on human health or the environment for purposes of...

  11. 40 CFR 158.34 - Flagging of studies for potential adverse effects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Flagging of studies for potential adverse effects. 158.34 Section 158.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES General Provisions § 158.34 Flagging of studies for potential adverse effects. (a)...

  12. Adversity and advancing nursing knowledge.

    PubMed

    Reed, Pamela G

    2008-04-01

    This column reports the theme of adversity addressed in reference to theoretical and metatheoretical considerations for advancing nursing knowledge. The development and content of three classic nursing theories are presented by Neuman representatives, and by theorists King and Roy. Topics for continued dialogue are identified as derived from the interface between philosophy of science issues and these theories. PMID:18378823

  13. Adverse Childhood Experiences and Hallucinations

    ERIC Educational Resources Information Center

    Whitfield, C.L.; Dube, S.R.; Felitti, V.J.; Anda, R.F.

    2005-01-01

    Objective:: Little information is available about the contribution of multiple adverse childhood experiences (ACEs) to the likelihood of reporting hallucinations. We used data from the ACE study to assess this relationship. Methods:: We conducted a survey about childhood abuse and household dysfunction while growing up, with questions about health…

  14. Adverse ocular reactions to drugs.

    PubMed Central

    Spiteri, M. A.; James, D. G.

    1983-01-01

    Drugs acting on various parts of the body may also affect the eye insidiously. Increased awareness of such drug toxicity by the prescribing doctor should encourage him to consider effects on the cornea, lens, retina, optic nerve and elsewhere when checking the patient's progress. The following review concerns adverse ocular effects of systemic drug administration. PMID:6356101

  15. Space Environment Exposure Results from the MISSE 5 Polymer Film Thermal Control Experiment on the International Space Station

    NASA Technical Reports Server (NTRS)

    Miller, Sharon K. R.; Dever, Joyce A.

    2009-01-01

    It is known that polymer films can degrade in space due to exposure to the environment, but the magnitude of the mechanical property degradation and the degree to which the different environmental factors play a role in it is not well understood. This paper describes the results of an experiment flown on the Materials International Space Station Experiment (MISSE) 5 to determine the change in tensile strength and % elongation of some typical polymer films exposed in a nadir facing environment on the International Space Station and where possible compare to similar ram and wake facing experiments flown on MISSE 1 to get a better indication of the role the different environments play in mechanical property change.

  16. Real-Time Thermographic-Phosphor-Based Temperature Measurements of Thermal Barrier Coating Surfaces Subjected to a High-Velocity Combustor Burner Environment

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Jenkins, Thomas P.; Allison, Stephen W.; Cruzen, Scott; Condevaux, J. J.; Senk, J. R.; Paul, A. D.

    2011-01-01

    Surface temperature measurements were conducted on metallic specimens coated with an yttria-stabilized zirconia (YSZ) thermal barrier coating (TBC) with a YAG:Dy phosphor layer that were subjected to an aggressive high-velocity combustor burner environment. Luminescence-based surface temperature measurements of the same TBC system have previously been demonstrated for specimens subjected to static furnace or laser heating. Surface temperatures were determined from the decay time of the luminescence signal of the YAG:Dy phosphor layer that was excited by a pulsed laser source. However, the furnace and laser heating provides a much more benign environment than that which exists in a turbine engine, where there are additional challenges of a highly radiant background and high velocity gases. As the next step in validating the suitability of luminescence-based temperature measurements for turbine engine environments, new testing was performed where heating was provided by a high-velocity combustor burner rig at Williams International. Real-time surface temperature measurements during burner rig heating were obtained from the decay of the luminescence from the YAG:Dy surface layer. The robustness of several temperature probe designs in the sonic velocity, high radiance flame environment was evaluated. In addition, analysis was performed to show whether the luminescence decay could be satisfactorily extracted from the high radiance background.

  17. THE THERMAL EVOLUTION OF ICES IN THE ENVIRONMENTS OF NEWLY FORMED STARS: THE CO{sub 2} DIAGNOSTIC

    SciTech Connect

    Cook, A. M.; Whittet, D. C. B.; Shenoy, S. S.; Gerakines, P. A.; White, D. W.; Chiar, J. E.

    2011-04-01

    Archival data from the Infrared Spectrometer of the Spitzer Space Telescope are used to study the 15 {mu}m absorption feature of solid CO{sub 2} toward 28 young stellar objects (YSOs) of approximately solar mass. Fits to the absorption profile using laboratory spectra enable categorization according to the degree of thermal processing of the ice matrix that contains the CO{sub 2}. The majority of YSOs in our sample (20 out of 28) are found to be consistent with a combination of polar (H{sub 2}O-rich) and nonpolar (CO-rich) ices at low temperature; the remainder exhibit profile structure consistent with partial crystallization as the result of significant heating. Ice-phase column densities of CO{sub 2} are determined and compared with those of other species. Lines of sight with crystallization signatures in their spectra are found to be systematically deficient in solid-phase CO, as expected if CO is being sublimated in regions where the ices are heated to crystallization temperatures. Significant variation is found in the CO{sub 2} abundance with respect to both H{sub 2}O (the dominant ice constituent) and total dust column (quantified by the extinction, A{sub V}). YSOs in our sample display typically higher CO{sub 2} concentrations (independent of evidence for thermal processing) in comparison to quiescent regions of the prototypical cold molecular cloud. This suggests that enhanced CO{sub 2} production is driven by photochemical reactions in proximity to some YSOs, and that photoprocessing and thermal processing may occur independently.

  18. Development and application of a thermal desorption-based method for the determination of nicotine in inddor environments

    SciTech Connect

    Jenkins, R.A.; Thompson, C.V.; Higgins, C.E.

    1988-01-01

    A personal monitoring system for the determination of exposure to nicotine has been developed. The system consists of a sampling cartidge packed with 200 mg of Tenax GC/sup R/ and a small, constant flow, personal sampling pump. After sampling, the cartridges are analyzed by triethylamine-assisted thermal desorption gas chromatography with nitrogen-selective detection. Collection and desorption efficiencies for the cartridges have been determined. The system has been applied in a variety of work sites, and in 36 restaurants, where measured concentrations of nicotine ranged from 0.5 to 37.2 ..mu..gm/sup /minus/3/. 25 refs., 2 figs., 4 tabs.

  19. Developmental and Immediate Thermal Environments Shape Energetic Trade-Offs, Growth Efficiency, and Metabolic Rate in Divergent Life-History Ecotypes of the Garter Snake Thamnophis elegans.

    PubMed

    Gangloff, Eric J; Vleck, David; Bronikowski, Anne M

    2015-01-01

    Interactions at all levels of ecology are influenced by the rate at which energy is obtained, converted, and allocated. Trade-offs in energy allocation within individuals in turn form the basis for life-history theory. Here we describe tests of the influences of temperature, developmental environment, and genetic background on measures of growth efficiency and resting metabolic rate in an ectothermic vertebrate, the western terrestrial garter snake (Thamnophis elegans). After raising captive-born snakes from divergent life-history ecotypes on thermal regimes mimicking natural habitat differences (2 × 2 experimental design of ecotype and thermal environment), we measured oxygen consumption rate at temperatures spanning the activity range of this species. We found ecotypic differences in the reaction norms of snakes across the measured range of temperatures and a temperature-dependent allometric relationship between mass and metabolic rate predicted by the metabolic-level boundaries hypothesis. Additionally, we present evidence of within-individual trade-offs between growth efficiency and resting metabolic rate, as predicted by classic life-history theory. These observations help illuminate the ultimate and proximate factors that underlie variation in these interrelated physiological and life-history traits. PMID:26658251

  20. Electrical conductivity of the thermal dusty plasma under the conditions of a hybrid plasma environment simulation facility

    NASA Astrophysics Data System (ADS)

    Zhukhovitskii, Dmitry I.; Petrov, Oleg F.; Hyde, Truell W.; Herdrich, Georg; Laufer, Rene; Dropmann, Michael; Matthews, Lorin S.

    2015-05-01

    We discuss the inductively heated plasma generator (IPG) facility in application to the generation of the thermal dusty plasma formed by the positively charged dust particles and the electrons emitted by them. We develop a theoretical model for the calculation of plasma electrical conductivity under typical conditions of the IPG. We show that the electrical conductivity of dusty plasma is defined by collisions with the neutral gas molecules and by the electron number density. The latter is calculated in the approximations of an ideal and strongly coupled particle system and in the regime of weak and strong screening of the particle charge. The maximum attainable electron number density and corresponding maximum plasma electrical conductivity prove to be independent of the particle emissivity. Analysis of available experiments is performed, in particular, of our recent experiment with plasma formed by the combustion products of a propane-air mixture and the CeO2 particles injected into it. A good correlation between the theory and experimental data points to the adequacy of our approach. Our main conclusion is that a level of the electrical conductivity due to the thermal ionization of the dust particles is sufficiently high to compete with that of the potassium-doped plasmas.

  1. Evaluation of Titanium Nitride-Modified Bondcoat System Used in Thermal Barrier Coating in Corrosive Salts Environment at High Temperature

    NASA Astrophysics Data System (ADS)

    Qureshi, Imran Nazir; Shahid, Muhammad; Nusair Khan, A.; Durrani, Yaseer A.

    2015-12-01

    Thermal barrier coating (TBC) systems were produced by air plasma spraying system on nickel base superalloy. These coatings were composed of a Y2O3-stabilized ZrO2 topcoat and a CoNiCrAlY bondcoat and are known as standard TBC. In this paper, standard TBC samples were compared with TiN-modified bondcoat TBC samples. Titanium nitride was deposited by utilizing a physical vapor deposition technique. Both TBC systems were exposed to high temperature in the presence of corrosive salts, i.e. a mixture of V2O5 and Na2SO4 (50:50) for 50 h. It was observed that the TiN-modified samples showed better results in terms of oxidation resistance and delamination. The formation of Cr2Ti n-2O2 n-1 phases at the interface of the topcoat-bondcoat, in TiN-modified samples were found to enhance the thermal and oxidation properties of the TBC.

  2. Near-surface seismic velocity changes in a salt-dominated environment due to shaking and thermal stressing

    NASA Astrophysics Data System (ADS)

    Richter, Tom; Sens-Schönfelder, Christoph; Kind, Rainer; Asch, Günter

    2014-05-01

    We report on results from a seismic station of the Integrated Plate Boundary Observatory Chile (IPOC) showing a superior sensitivity of seismic velocity changes in the surrounding medium to shaking and temperature. 5 years of daily autocorrelations of the IPOC network are analyzed with passive image interferometry. Due to the particular geological conditions we observe a high sensitivity of the medium around the station near Patache (PATCX) resulting in annual periodic velocity variations and temporary velocity reductions induced by ground shaking. We observe a linear relationship between the amplitude of the velocity reductions and the peak ground acceleration (PGA) of nearby earthquakes at station PATCX. Although velocity reductions are also observed at other stations of the IPOC array for the Mw 7.7 Tocopilla earthquake a clear relationship between the PGA of this earthquake and the induced velocity reductions at the different stations is not visible. Furthermore, we observe velocity variations with an annual and daily period. We present different arguments that these periodic changes are caused by variations of the atmospheric temperature. In this context we construct a model that starts at observed temperature variations and evaluates thermal stresses induced by the temperature gradients. Using radiative transfer based sensitivity kernels and third order elastic constants we relate the distribution of thermal stress in the subsurface to observable time shifts of coda waves. The model is able to reproduce the major features confirming that stress changes in the subsurface can be detected with noise based monitoring.

  3. 1-D Transient Thermal Modeling of an Ablative Material (MCC-1) Exposed to a Simulated Convective Titan 4 Launch Environment

    NASA Technical Reports Server (NTRS)

    Reinarts, Thomas R.; Crain, William K.; Stuckey, C. Irvin; Palko, Richard L.

    1998-01-01

    The purpose of the work is to demonstrate that the flat test panel substrate temperatures are consistent with analysis predictions for MCC-1 applied to a aluminum substrate. The testing was performed in an aerothermal facility on samples of three different thicknesses of MCC-1 on an aluminum substrate. The results of the test were compared with a Transient Thermal model. The key assumptions of the Transient Thermal model were: (1) a one-dimensional heat transfer; (2) a constant ablation recession rate (determined from pre and post-test measurements); (3) ablation temperature of 540 degrees F; (4) Char left behind the ablation front; and (5) temperature jump correction for incident heat transfer coefficient. Two methods were used to model the heating of bare MCC-1: (1) Directly input surface temperature as a function of time; and (2) Aerothermal heating using calibration plate data and subtracting the radiation losses to tunnel walls. The results are presented as graphs. This article is presented in Viewgraph format.

  4. Experiment on large scale plume interaction with a stratified gas environment resembling the thermal activity of a autocatalytic recombiner

    SciTech Connect

    Mignot, G.; Kapulla, R.; Paladino, D.; Zboray, R.

    2012-07-01

    Computational Fluid Dynamics codes (CFD) are increasingly being used to simulate containment conditions after various transient accident scenarios. Consequently, the reliability of such codes must be tested against experimental data. Such validation experiments related to gas mixing and hydrogen transport within containment compartments addressing the effect of heat source are presented in this paper. The experiments were conducted in the large-scale thermal-hydraulics PANDA facility located at the Paul-Scherrer-Inst. (PSI) in Switzerland, in the frame of the OECD/SETH-2 project. A 10 kW electric heater simulating the thermal activity of the autocatalytic recombiner was activated at full power in a containment vessel at the top of which a thick helium layer is initially present. The hot plume interacts with the bottom of the helium layer which is slowly eroded until complete break up at 1350 s. After final erosion of the layer a strong temperature and concentration gradient is maintained in the vessel below the heater inlet as well as in the adjacent vessel below the interconnecting pipe. A detailed characterization of the operating heater suggests the presence of cold gas ingress at the outlet that affects the flow in the chimney. This can be of concern if present in a real PAR unit. (authors)

  5. Cardiovascular adverse effects of phenytoin.

    PubMed

    Guldiken, B; Rémi, J; Noachtar, Soheyl

    2016-05-01

    Phenytoin is an established drug in the treatment of acute repetitive seizures and status epilepticus. One of its main advantages over benzodiazepines is the less sedative effect. However, the possibility of cardiovascular adverse effects with the intravenous use of phenytoin cause a reluctance to its usage, and this has lead to a search for safer anticonvulsant drugs. In this study, we aimed to review the studies which evaluated the safety of phenytoin with respect to cardiovascular adverse effects. The original clinical trials and case reports listed in PUBMED in English language between the years of 1946-2014 were evaluated. As the key words, "phenytoin, diphenylhydantoin, epilepsy, seizure, cardiac toxicity, asystole, arrhythmia, respiratory arrest, hypotension, death" were used. Thirty-two clinical trials and ten case reports were identified. In the case reports, a rapid infusion rate (>50 mg/min) of phenytoin appeared as the major cause of increased mortality. In contrast, no serious cardiovascular adverse effects leading to death were met in the clinical trials which applied the recommended infusion rate and dosages. An infusion rate of 50 mg/min was reported to be safe for young patients. For old patients and patients with a cardiovascular co-morbidity, a slower infusion rate was recommended with a careful follow-up of heart rhythm and blood pressure. No cardiovascular adverse effect was reported in oral phenytoin overdoses except one case with a very high serum phenytoin level and hypoalbuminemia. Phenytoin is an effective and well tolerated drug in the treatment of epilepsy. Intravenous phenytoin is safe when given at recommended infusion rates and doses. PMID:26645393

  6. [Adverse events of psychotropic drugs].

    PubMed

    Watanabe, Koichiro; Kikuchi, Toshiaki

    2014-01-01

    The authors discuss adverse events which are often missed but clinicians should pay attention to in order to preserve patients'quality of life(QOL). Among mood stabilizers, lithium may cause a urinary volume increase, hyperparathyroidism, and serum calcium elevation; sodium valproate possibly increases androgenic hormone levels and the risk of polycystic ovary syndrome (PCOS) as well as hypothyroidism. Moreover, in addition to teratogenesis, it has been reported that fetal exposure to a higher dose of valproate is associated with a lower intelligence quotient and higher incidence of autism spectrum disorders in children. Antidepressants with a higher affinity for serotonin transporters might induce gastrointestinal bleeding, and some antidepressants cause sexual dysfunction more frequently than others. Activation syndrome is still a key side effect which should be noted. Regarding the adverse events of antipsychotics, subjective side effects unpleasant to patients such as dysphoria and a lower subjective well-being should not be overlooked. We clinicians have to cope with adverse events worsening the QOL of patients with psychiatric disorders and, therefore, we need to adopt appropriate counter-measures. PMID:24864567

  7. Adverse Effects of Common Drugs: General Concepts.

    PubMed

    Karpa, Kelly Dowhower; Lewis, Peter R; Felix, Todd Matthew

    2015-09-01

    Adverse drug reactions (ADRs) contribute to substantial morbidity and mortality and add to rising health care costs. Many ADRs are preventable with appropriate prescribing and monitoring because they often occur as an extension of a drug's mechanism of action or known drug interactions. Patients at higher risk of ADRs include those at the extremes of age, those with multiple comorbidities, those taking multiple drugs, and patients admitted to intensive care units or experiencing transitions of care. Because the risk of ADRs becomes greater as the number of drugs and dietary supplements taken increases, it is imperative that prescribers be vigilant about the prescribing cascade and take steps to discontinue drugs that are likely to be more harmful than helpful. Pharmacists serve as important partners in clinical care environments by conducting comprehensive drug reviews, aiding in drug/dosage selection, and developing therapeutic monitoring plans. Although the potential exists for clinicians to use electronic health record systems to aid in clinical decision making through drug safety decision support tools, computer systems should never replace clinical judgment. Clinicians also are encouraged to report ADRs to the Food and Drug Administration Adverse Event Reporting System. PMID:26375993

  8. Thermal influences on the displacement of a deep-seated rock instability in a permafrost environment in Switzerland

    NASA Astrophysics Data System (ADS)

    Amann, F.; Kos, A.; Lafranchi, O.

    2012-12-01

    An unstable rock slope occurring within a probable permafrost zone at 2772 m.a.s.l was monitored over a 2 year period to determine thermal influences on rock slope displacements. Our results show that ice wedging is an important process, and suggests the hypothesis of strength-loss of ice-filled tensile cracks typically associated with permafrost degradation, is not relevant. The unstable rock slope is part of a mountain ridge known as the Kaerpf located in the Central Swiss Alps. Several rock slope failures at the Kaerpf have been observed since 2005, characterized by the collapse of rock towers with volumes ranging between 3'000 and 16'000 m3. All of the events occurred in the late summer between August and September. Based on the observation that ice-filled cracks were present at several locations within the unstable area and preliminary monitoring data, we initially hypothesized that the ice-filled cracks underwent strength-loss as a consequence of the annual thermal-peak occurring in late summer-early autumn (e.g. maximum annual penetration of heat within the rock mass), thereby offering an explanation for the timing of the observed failure events. Characteristics of the rock mass showed a strong predisposition for the type of failures observed since 2005. The rock slope instability is primarily controlled by dip-slope geometry, where deep seated sliding (~20-30m depth) takes place along a 30° inclined weak Phyllite layer. The Phyllite is sandwiched between hard and massive rocks of volcanic origin, which form the upper ridge and lower toe of the slope. As a consequence of deep seated sliding, rock towers separate along persistent sub-vertical discontinuities in the upper massive hard rock types. Once separated, the rock towers have a high degree of freedom to dislocate or rotate, where a combination of toppling and sliding represent the key failure mechanisms. The monitoring data, consisting of ground-based and aerial laser scanning, ground-based radar

  9. Detecting Adverse Events Using Information Technology

    PubMed Central

    Bates, David W.; Evans, R. Scott; Murff, Harvey; Stetson, Peter D.; Pizziferri, Lisa; Hripcsak, George

    2003-01-01

    Context: Although patient safety is a major problem, most health care organizations rely on spontaneous reporting, which detects only a small minority of adverse events. As a result, problems with safety have remained hidden. Chart review can detect adverse events in research settings, but it is too expensive for routine use. Information technology techniques can detect some adverse events in a timely and cost-effective way, in some cases early enough to prevent patient harm. Objective: To review methodologies of detecting adverse events using information technology, reports of studies that used these techniques to detect adverse events, and study results for specific types of adverse events. Design: Structured review. Methodology: English-language studies that reported using information technology to detect adverse events were identified using standard techniques. Only studies that contained original data were included. Main Outcome Measures: Adverse events, with specific focus on nosocomial infections, adverse drug events, and injurious falls. Results: Tools such as event monitoring and natural language processing can inexpensively detect certain types of adverse events in clinical databases. These approaches already work well for some types of adverse events, including adverse drug events and nosocomial infections, and are in routine use in a few hospitals. In addition, it appears likely that these techniques will be adaptable in ways that allow detection of a broad array of adverse events, especially as more medical information becomes computerized. Conclusion: Computerized detection of adverse events will soon be practical on a widespread basis. PMID:12595401

  10. Thermally Sprayed Aluminum (TSA) Coatings for Extended Design Life of 22%Cr Duplex Stainless Steel in Marine Environments

    NASA Astrophysics Data System (ADS)

    Paul, S.; Shrestha, S.; Lee, C. M.; Harvey, M. D. F.

    2013-03-01

    In this article, evaluation of sealed and unsealed thermally sprayed aluminum (TSA) for the protection of 22%Cr duplex stainless steel (DSS) from corrosion in aerated, elevated temperature synthetic seawater is presented. The assessments involved general and pitting corrosion tests, external chloride stress corrosion cracking (SCC), and hydrogen-induced stress cracking (HISC). These tests indicated that DSS samples, which would otherwise fail on their own in a few days, did not show pitting or fail under chloride SCC and HISC conditions when coated with TSA (with or without a sealant). TSA-coated specimens failed only at very high stresses (>120% proof stress). In general, TSA offered protection to the underlying or exposed steel by cathodically polarizing it and forming a calcareous deposit in synthetic seawater. The morphology of the calcareous deposit was found to be temperature dependent and in general was of duplex nature. The free corrosion rate of TSA in synthetic seawater was measured to be ~5-8 μm/year at ~18 °C and ~6-7 μm/year at 80 °C.

  11. An Optimized Adsorbent Sampling Combined to Thermal Desorption GC-MS Method for Trimethylsilanol in Industrial Environments

    PubMed Central

    Lee, Jae Hwan; Jia, Chunrong; Kim, Yong Doo; Kim, Hong Hyun; Pham, Tien Thang; Choi, Young Seok; Seo, Young Un; Lee, Ike Woo

    2012-01-01

    Trimethylsilanol (TMSOH) can cause damage to surfaces of scanner lenses in the semiconductor industry, and there is a critical need to measure and control airborne TMSOH concentrations. This study develops a thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) method for measuring trace-level TMSOH in occupational indoor air. Laboratory method optimization obtained best performance when using dual-bed tube configuration (100 mg of Tenax TA followed by 100 mg of Carboxen 569), n-decane as a solvent, and a TD temperature of 300°C. The optimized method demonstrated high recovery (87%), satisfactory precision (<15% for spiked amounts exceeding 1 ng), good linearity (R2 = 0.9999), a wide dynamic mass range (up to 500 ng), low method detection limit (2.8 ng m−3 for a 20-L sample), and negligible losses for 3-4-day storage. The field study showed performance comparable to that in laboratory and yielded first measurements of TMSOH, ranging from 1.02 to 27.30 μg/m3, in the semiconductor industry. We suggested future development of real-time monitoring techniques for TMSOH and other siloxanes for better maintenance and control of scanner lens in semiconductor wafer manufacturing. PMID:22966229

  12. Performance of NiCrAlY Coatings Deposited by Oxyfuel Thermal Spraying in High Temperature Chlorine Environment

    NASA Astrophysics Data System (ADS)

    Habib, K. A.; Damra, M. S.; Carpio, J. J.; Cervera, I.; Saura, J. J.

    2014-10-01

    A microcrystalline Ni-22Cr-10Al-1Y (wt.%) coating was deposited on AISI 304 stainless steel by the oxyfuel thermal spray technique. The deposited coating was subjected to heat treatment to improve the microstructure characteristics and its corresponding high-temperature properties. The isothermal high-temperature corrosion behavior at 650 and 700 °C in synthetic air and in the presence of 1% Cl2 was investigated using thermogravimetric analysis, x-ray diffraction, and scanning electron microscopy with energy-dispersive x-ray spectroscopy. The results indicated that the deposited NiCrAlY coating possessed acceptable oxidation-corrosion resistance at 650 °C owing to the formation of extensive amounts of the protective oxide of Cr2O3; NiO and a lesser amount of a Cr1.12 Ni2,88 metallic phase are also formed. At 700 °C, the coating lost its protective characteristic because of the excessive consumption of thermodynamically stable phases by oxidation-chlorination process. In this case, the steel base and the coating were attacked by chlorine during the exposure time; the mass gain of the NiCrAlY coating was slightly higher and provided only a limited protection up to 11 h; thereafter, breakdown of the layer of oxides occurred and this is attributed to the formation of non-protective oxides mainly β-Fe2O3 and Fe21.33O32 and the depletion of chromium.

  13. [Adverse ocular effects of vaccinations].

    PubMed

    Ness, T; Hengel, H

    2016-07-01

    Vaccinations are very effective measures for prevention of infections but are also associated with a long list of possible side effects. Adverse ocular effects following vaccination have been rarely reported or considered to be related to vaccinations. Conjunctivitis is a frequent sequel of various vaccinations. Oculorespiratory syndrome and serum sickness syndrome are considered to be related to influenza vaccinations. The risk of reactivation or initiation of autoimmune diseases (e. g. uveitis) cannot be excluded but has not yet been proven. Overall the benefit of vaccination outweighs the possible but very low risk of ocular side effects. PMID:27357302

  14. Adverse Effects of Electroconvulsive Therapy.

    PubMed

    Andrade, Chittaranjan; Arumugham, Shyam Sundar; Thirthalli, Jagadisha

    2016-09-01

    Electroconvulsive therapy (ECT) is an effective treatment commonly used for depression and other major psychiatric disorders. We discuss potential adverse effects (AEs) associated with ECT and strategies for their prevention and management. Common acute AEs include headache, nausea, myalgia, and confusion; these are self-limiting and are managed symptomatically. Serious but uncommon AEs include cardiovascular, pulmonary, and cerebrovascular events; these may be minimized with screening for risk factors and by physiologic monitoring. Although most cognitive AEs of ECT are short-lasting, troublesome retrograde amnesia may rarely persist. Modifications of and improvements in treatment techniques minimize cognitive and other AEs. PMID:27514303

  15. Chemical analyses of soil samples collected from the vicinity of the thermal test complex at Sandia National Laboratories, New Mexico environs, 2006.

    SciTech Connect

    Miller, Mark Laverne; Nieto, Danielle M.

    2007-01-01

    In the summer of 2006, the Environmental Programs and Assurance Department of Sandia National Laboratories in Albuquerque, New Mexico (SNL/NM), collected surface soil samples at 37 locations within one mile of the vicinity of the newly constructed Thermal Test Complex (TTC) for the purpose of determining baseline conditions against which potential future impacts to the environs from operations at the facility could be assessed. These samples were submitted to an offsite analytical laboratory for metal-in-soil analyses. This work provided the SNL Environmental Programs and Assurance Department with a sound baseline data reference set against which to assess potential future operational impacts at the TTC. In addition, it demonstrates the commitment that the Laboratories have to go beyond mere compliance to achieve excellence in its operations. This data are presented in graphical format with narrative commentaries on particular items of interest.

  16. Effects of the Thermal Environment on Articular Chondrocyte Metabolism: A Fundamental Study to Facilitate Establishment of an Effective Thermotherapy for Osteoarthritis

    PubMed Central

    Ito, Akira; Aoyama, Tomoki; Tajino, Junichi; Nagai, Momoko; Yamaguchi, Shoki; Iijima, Hirotaka; Zhang, Xiangkai; Akiyama, Haruhiko

    2014-01-01

    Aim: To facilitate establishment of an effective thermotherapy for osteoarthritis (OA), we investigated the effects of the thermal environment on articular chondrocyte metabolism in vitro. Methods: Chondrocytes were isolated from porcine knee joints, and cultured at 32°C, 37°C and 41°C. Cell proliferation and viability were assessed at Days 2, 4 and 8. In addition, TdT-mediated dUTP nick end labeling (TUNEL) assay was performed at Day 3 to determine the proportion of apoptotic chondrocytes. Analysis of genes specific for factors related to the cartilage extracellular matrix (ECM), cartilage destruction, and cartilage protection was performed at Day 2. Furthermore, evaluation of heat stress tolerance, and heat shock protein 70 (HSP70) mRNA expression and protein synthesis was performed at Day 2 and 3, respectively. Results: Cell proliferation was more at 37°C than at 32°C and 41°C. Cell viability and the number of TUNEL-positive cells were not affected until Day 8 and 3, respectively. The expression of the ECM-related genes was up-regulated at higher temperature. The expression of MMP13, a type II collagen destructive enzyme, and that of TIMP1 and TIMP2, which are MMP inhibitors, were up-regulated at higher temperatures. Finally, the chondrocytes cultured at 41°C may acquire heat stress tolerance, in part, due to the up-regulation of HSP70, and may inhibit apoptosis induced by various stresses, which is observed in OA. Conclusions: The thermal environment affects articular chondrocyte metabolism, and a heat stimulus of approximately 41°C could enhance chondrocyte anabolism and induce heat stress tolerance. PMID:25792904

  17. Time-lapse and UAV Thermal Imaging of Glacial and Periglacial Environments in the Peruvian Andes (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    McKenzie, J. M.; Wigmore, O.; Aubry-Wake, C.; Mark, B. G.; Hellstrom, R. A.; Lautz, L.

    2015-12-01

    In the tropics, the acquisition of high-resolution geospatial data of high-mountain glacial and periglacial systems presents unique challenges due to remote site access and very high elevations. For glaciers and hydrologic systems, a key variable of interest is surface temperature as it constrains glacier melt rates, traces hydrologic processes, and is needed for the calibration of energy budget models. We present results from two studies that acquired high resolution temperature data from the Cuchillacocha Glacier, Peru (9.24°S, 77.21°W). The glacier resides on the western drainage of the Cordillera Blanca with an elevation range of 4700 to 6096 m. In the first study we use high resolution time-lapse infrared imagery (5-10 minute interval over 3 days; 0.6 m2 pixel size) to observe diel changes in the surface energy budget of the glacier and to demonstrate how radiation from bare rock adjacent to the glacier may affect melt rates. In the second study we use a newly developed, inexpensive unmanned aerial vehicle (UAV) for high resolution multispectral mapping of the glacier (2 cm resolution orthomosaic and 5 cm resolution DEM). We present results showing how the time-lapse and the high-resolution UAV imagery can be combined to further strengthen our understanding of the Cuchillacocha Glacier's energy budget and possible insights about turbulent heat fluxes. While the new instruments provide unprecedented data acquisition capabilities, there is an outstanding need for proper data correction. Spatial/thermal control points and post-processing algorithms are needed to produce quantifiable datasets. For example, our post-processed time-lapse imagery has an r2 > 0.9 after emissivity, transmissivity and offset corrections.

  18. CEQATR Thermal Test Overview

    NASA Technical Reports Server (NTRS)

    Balusek, Alan R.

    2009-01-01

    A thermal test overview of the Constellation Environmental Qualification and Acceptance Test Requirement (CEQATR) is presented. The contents include: 1) CEQATR Thermal Test Overview; 2) CxP Environments; 3) CEQATR Table 1.2-1; 4) Levels of Assembly; 5) Definitions for Levels of Assembly; 6) Hardware Applicability; 7) CEQATR Thermal-Related Definitions; 8) Requirements for unit-level thermal testing; 9) Requirements for major assembly level thermal testing; 10) General thermal testing requirements; 11) General thermal cycle, thermal vacuum profiles; 12) Test tolerances; 13) Vacuum vs Ambient; 14) Thermal Gradient; 15) Sequence of Testing; 16) Alternative Strategies; 17) Protoflight; 18) Halt/Hass; 19) Humidity; and 20) Tailoring.

  19. Adverse drug reactions in dermatology.

    PubMed

    Ferner, R E

    2015-03-01

    Adverse drug reactions (ADRs) - that is, unintended and harmful responses to medicines - are important to dermatologists because many present with cutaneous signs and because dermatological treatments can cause serious ADRs. The detection of ADRs to new drugs is often delayed because they have a long latency or are rare or unexpected. This means that ADRs to newer agents emerge only slowly after marketing. ADRs are part of the differential diagnosis of unusual rashes. A good drug history that includes details of drug dose, time-course of the reaction and factors that may make the patient more susceptible, will help. For example, Stevens-Johnson syndrome with abacavir is much commoner in patients with HLA-B*5701, and has a characteristic time course. Newer agents have brought newer reactions; for example, acneiform rashes associated with epidermal growth factor receptor inhibitors such as erlotinib. Older systemic agents used to treat skin disease, including corticosteroids and methotrexate, cause important ADRs. The adverse effects of newer biological agents used in dermatology are becoming clearer; for example, hypersensitivity reactions or loss of efficacy from antibody formation and progressive multifocal leucoencephalopathy due to reactivation of latent JC (John Cunningham) virus infections during efalizumab treatment. Unusual or serious harm from medicines, including ADRs, medication errors and overdose, should be reported. The UK Yellow Card scheme is online, and patients can report their own ADRs. PMID:25622648

  20. [Recipients adverse reactions: guidance supports].

    PubMed

    Bazin, A

    2010-12-01

    Since 1994, adverse effects of transfusion transmitted to the French haemovigilance network are registered on "e-fit", the database of the French agency for the safety of health products (Afssaps). In order to improve their analysis, guidance supports have been made by Afssaps working groups. Each support deals with a blood transfusion side effect and is composed of five parts including pathophysiological mechanisms, diagnostic criteria, management recommendations, etiologic investigations and rules of filing the notification form on e-fit. The major characteristics of sheets published or soon-to-be published are presented: transfusion-related acute lung injury, transfusion-transmitted bacterial infection, non-haemolytic febrile reaction, allergic reaction, transfusion-associated circulatory overload, hypotensive transfusion reaction, alloimmunization, erythrocyte incompatibility reaction and hemosiderosis. These new supports give relevant guidelines allowing a better analysis and evaluation of recipients' adverse reactions, particularly their diagnosis, gravity and accountability. They could also initiate studies in European and international haemovigilance and transfusion networks. PMID:21051267

  1. Adverse effects of plasma transfusion.

    PubMed

    Pandey, Suchitra; Vyas, Girish N

    2012-05-01

    Plasma utilization has increased over the past two decades, and there is a growing concern that many plasma transfusions are inappropriate. Plasma transfusion is not without risk, and certain complications are more likely with plasma than other blood components. Clinical and laboratory investigations of the patients suffering reactions after infusion of fresh-frozen plasma (FFP) define the etiology and pathogenesis of the panoply of adverse effects. We review here the pathogenesis, diagnosis, and management of the risks associated with plasma transfusion. Risks commonly associated with FFP include: 1) transfusion-related acute lung injury, 2) transfusion-associated circulatory overload, and 3) allergic and/or anaphylactic reactions. Other less common risks include 1) transmission of infections, 2) febrile nonhemolytic transfusion reactions, 3) red blood cell alloimmunization, and 4) hemolytic transfusion reactions. The effects of pathogen inactivation or reduction methods on these risks are also discussed. Fortunately, a majority of the adverse effects are not lethal and are adequately treated in clinical practice. PMID:22578374

  2. The Corrosion of High Performance Steel in Adverse Environments

    NASA Astrophysics Data System (ADS)

    Cook, Desmond C.

    2005-04-01

    The corrosion products that have formed on weathering steel bridges exposed to different weather conditions in the United States have been evaluated. They have been analyzed by spectroscopic techniques to determine the relationship between protective and non-protective rust coatings, and their relationship to the exposure conditions. Bridges constructed recently using High Performance Steel, as well as older bridges built with Type A588B weathering steel, were evaluated for corrosion performance of the rust coatings. In locations where the steel is subjected to regular wet-dry cycling, where the surface is wet for less than about 20% of the time, a protective patina starts to form after a few months exposure, and continues to an adherent, impervious coating after a decade. The protective patina is characterized by the formation of only goethite and lepidocrocite. The goethite makes up about 80% of the rust, and itself consists of a nanophase component, < 15 nm, making up about 70% of the goethite. The nanophase goethite is basically undetected by X-ray diffraction. In the presence of high time-of-wetness, >40%, or infrequent drying cycles, (regions close to waterways, fog or having high humidity), the weathering steel forms a rust coating that consists of a large amount of maghemite, and goethite that contains very little of the nanophase component. The rust coating ex-foliates from the steel and is not protective. Under exposure conditions in which chlorides are deposited onto the weathering steel surface, (marine or de-icing salt locations), the protective patina also does not form. Instead, the rust coating consists of a large fraction of akaganeite that forms at the expense of the lepidocrocite and nanophase goethite. The bridges exposed to high chloride concentrations, 1.5 wt%, and therefore having no protective patina, have corrosion rates measured to be 6 times larger than expected for weathering steel with the protective patina.

  3. The Corrosion of High Performance Steel in Adverse Environments

    SciTech Connect

    Cook, Desmond C.

    2005-04-26

    The corrosion products that have formed on weathering steel bridges exposed to different weather conditions in the United States have been evaluated. They have been analyzed by spectroscopic techniques to determine the relationship between protective and non-protective rust coatings, and their relationship to the exposure conditions. Bridges constructed recently using High Performance Steel, as well as older bridges built with Type A588B weathering steel, were evaluated for corrosion performance of the rust coatings. In locations where the steel is subjected to regular wet-dry cycling, where the surface is wet for less than about 20% of the time, a protective patina starts to form after a few months exposure, and continues to an adherent, impervious coating after a decade. The protective patina is characterized by the formation of only goethite and lepidocrocite. The goethite makes up about 80% of the rust, and itself consists of a nanophase component, < 15 nm, making up about 70% of the goethite. The nanophase goethite is basically undetected by X-ray diffraction. In the presence of high time-of-wetness, >40%, or infrequent drying cycles (regions close to waterways, fog or having high humidity), the weathering steel forms a rust coating that consists of a large amount of maghemite, and goethite that contains very little of the nanophase component. The rust coating ex-foliates from the steel and is not protective. Under exposure conditions in which chlorides are deposited onto the weathering steel surface (marine or de-icing salt locations), the protective patina also does not form. Instead, the rust coating consists of a large fraction of akaganeite that forms at the expense of the lepidocrocite and nanophase goethite. The bridges exposed to high chloride concentrations, 1.5 wt%, and therefore having no protective patina, have corrosion rates measured to be 6 times larger than expected for weathering steel with the protective patina.

  4. Mu opioid receptor polymorphism, early social adversity, and social traits.

    PubMed

    Carver, Charles S; Johnson, Sheri L; Kim, Youngmee

    2016-10-01

    A polymorphism in the mu opioid receptor gene OPRM1 (rs1799971) has been investigated for its role in sensitivity to social contexts. Evidence suggests that the G allele of this polymorphism is associated with higher levels of sensitivity. This study tested for main effects of the polymorphism and its interaction with a self-report measure of childhood adversity as an index of negative environment. Outcomes were several personality measures relevant to social connection. Significant interactions were obtained, such that the negative impact of childhood adversity on personality was greater among G carriers than among A homozygotes on measures of agreeableness, interdependence, anger proneness, hostility, authentic pride, life engagement, and an index of (mostly negative) feelings coloring one's world view. Findings support the role of OPRM1 in sensitivity to negative environments. Limitations are noted, including the lack of a measure of advantageous social environment to assess sensitivity to positive social contexts. PMID:26527429

  5. 18 CFR 292.211 - Petition for initial determination on whether a project has a substantial adverse effect on the...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... that the Commission make an initial determination on the adverse environmental effects requirements in...)(1), proposed measures to mitigate the adverse environmental effects found. (3)(i) The Commission... determination on whether a project has a substantial adverse effect on the environment (AEE petition)....

  6. "Adversative Conjunction": The Poetics of Linguistic Opposition.

    ERIC Educational Resources Information Center

    Wallerstein, Nicholas

    1992-01-01

    The general use of adversative conjunction in (primarily) English and U.S. poetry is outlined. The contention is that the adversative is not merely a grammatical convenience but sometimes a highly functional tool of rhetorical strategy. (36 references) (LB)

  7. Ecophysiological adaptations to dry thermal environments measured in two unrestrained Namibian scorpions, Parabuthus villosus (Buthidae) and Opisthophthalmus flavescens (Scorpionidae).

    PubMed

    Bridges, C R; le Roux, J M; van Aardt, W J

    1997-01-01

    under temperature stress. The differences in the normal thermal habitats of the two species may be used to explain the distinctions between the evolved physiological responses to temperature increase shown by the two species. PMID:9231398

  8. Thermal Responses in Football and Cross-Country Athletes During Their Respective Practices in a Hot Environment

    PubMed Central

    Godek, Joseph J.; Bartolozzi, Arthur R.

    2004-01-01

    Objective: To determine if football (FB) players and cross-country (CC) runners had different thermal responses to their respective training sessions. Design and Setting: On days 4 and 8 of preseason training, we assessed core (Tc) and skin (Tsk) temperatures. Subjects: Fifteen collegiate athletes volunteered: 10 FB players (age = 21.2 ± 1.14 years, height = 193.5 ± 4.8 cm, mass = 116.6 ± 16.3 kg, and V2max = 44.7 ± 9.4 mL·kg−1·min−1) and 5 CC runners (age = 22.8 ± 2.77 years, height = 176.3 ± 8.9 cm, mass = 71.16 ± 8.9 kg, and V2max = 71.3 ± 6.18 mL·kg−1·min−1). Measurements: We measured Tc using ingestible sensors before, during, and immediately after exercise. The Tsk was measured at the calf, forearm, back, chest, and forehead sites. Level of dehydration was assessed by urine specific gravity. Results: Mean wet-bulb temperature was 74°F (23.33°C). Resting Tc in shorts and T-shirts was higher in the FB group. The Tc midway through practices and runs was higher in the CC and FB subjects when active, compared with the FB subjects when inactive. Postexercise Tc was higher in the CC group than the FB group with pads, and postconditioning Tc was higher in the FB subjects with pads versus no pads. Forehead, chest, back, and mean weighted Tsk were higher in the FB group. The Tc and urine specific gravity were not correlated. Conclusions: The Tc fluctuated in the FB subjects during practice depending on exercise intensity, whereas Tc increased steadily in the CC subjects during continuous running. Thus, CC athletes may have to decrease intensity to maintain thermoregulation. Our FB players seemed to dissipate heat adequately during rest periods. PMID:15496992

  9. Aerosols Collected at a Tropical Marine Environment: Size-Resolved Chemical Composition Using IC, TOC, and Thermal-Optical Analyses

    NASA Astrophysics Data System (ADS)

    Morales-García, F.; Mayol-Bracero, O. L.; Repollet-Pedrosa, M.; Kasper-Giebl, A.; Ramírez-Santa Cruz, C.; Puxbaum, H.

    2009-05-01

    Size-resolved chemical characterization was performed on aerosol samples collected at two different marine sites in the tropics: Dian Point (DP), Antigua and Cape San Juan (CSJ), Puerto Rico. A 13-stage Dekati low- pressure impactor (Dp 0.1 to 10 μm), a 10-stage micro-orifice uniform deposit impactor (Dp 0.054 to 18 μm), and stacked-filter units (Dp < 1.7 μm) were used to collect the samples. Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO2-, NO3-, SO42-, acetate, formate, malonate, and oxalate were determined using ion chromatography (IC). Thermal-optical analysis (TOA) was used to determine the concentrations of aerosol total carbon (TC), organic carbon (OC), and elemental carbon (EC). Five-day back trajectories calculated using NOAA's HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model identified air masses coming from the North Atlantic (maritime air), Northwest Africa (desert dust), and North America (anthropogenic pollution). Size-resolved chemical characterization of aerosol samples using IC and TOA confirmed that aerosols become aged as they are transported to the Caribbean and their composition depends on the air mass origin. Gravimetric analyses showed that average fine mass concentrations for CSJ station were higher than for DP station (CSJ: 1.9 μg m-3; DP: 1.2 μg m-3). The aerosol chemical composition changed with air masses of different origin and with different pollution levels. In both locations the predominant water-soluble ions in the fine aerosol fraction were Cl-, Na+, and SO42-. Sulphate was observed in higher concentrations during the polluted case and particulate organic matter concentrations were higher for the maritime case. During desert dust events an increase in Ca2+ and Mg2+ of 4 and 2 times, respectively, was observed mainly in the coarse mode. Results for the size-resolved chemical composition and complete aerosol chemical apportionment including the residual mass will be presented.

  10. Environment and the skin.

    PubMed

    Suskind, R R

    1977-10-01

    The skin is an important interface between man and his environment; it is an important portal of entry for hazardous agents and a vulnerable target tissue as well. It is a uniquely accessible model system for detecting hazards and for studying mechanisms of a wide variety of biologic funcitons. Environmental causes of skin reactions comprise a vast array of physical, chemical and biological agents. To appreciate the role of the skin as an interface with man's environment, it is necessary to understand the multiple adaptive mechanisms, and the defenses of the skin against the environmental stresses. The skin is endowed with a versatile group of defenses against penetration, fluid loss from the body, thermal stress, solar radiation, physical trauma and microbial agents. Patterns of adverse response range in quality and intensity from uncomplicated itching to metastatic neoplasia. Environmental problems comprise a large segment of disabling skin disease. Although critical epidemiologic data is limited, cutaneous illnesses comprise a significant segment of occupational disease. This represents a significant loss in productivity and a major cause of disability. The most serious research needs include the development of surveillance systems for identifying skin hazards and determining frequency of environmental skin disease; the development of new models for studying cutaneous penetration; the elucidation of the mechanisms of nonallergic inflammatory reactions (primary irritation) and of the accommodation phenomenon; the development of more sensitive models for predicting adverse responses to marginal irritants; the utilization of modern skills of immunobiology and immunochemistry to elucidate mechanisms of allergic responses; the launching of epidemiologic studies to determine the long term effects of PCBs and associated compounds such as dioxins; and the expansion of research in the mechanisms of skin cancer in relation to susceptibility, genetic and metabolic

  11. Environment and the skin

    PubMed Central

    Suskind, Raymond R.

    1977-01-01

    The skin is an important interface between man and his environment; it is an important portal of entry for hazardous agents and a vulnerable target tissue as well. It is a uniquely accessible model system for detecting hazards and for studying mechanisms of a wide variety of biologic funcitons. Environmental causes of skin reactions comprise a vast array of physical, chemical and biological agents. To appreciate the role of the skin as an interface with man's environment, it is necessary to understand the multiple adaptive mechanisms, and the defenses of the skin against the environmental stresses. The skin is endowed with a versatile group of defenses against penetration, fluid loss from the body, thermal stress, solar radiation, physical trauma and microbial agents. Patterns of adverse response range in quality and intensity from uncomplicated itching to metastatic neoplasia. Environmental problems comprise a large segment of disabling skin disease. Although critical epidemiologic data is limited, cutaneous illnesses comprise a significant segment of occupational disease. This represents a significant loss in productivity and a major cause of disability. The most serious research needs include the development of surveillance systems for identifying skin hazards and determining frequency of environmental skin disease; the development of new models for studying cutaneous penetration; the elucidation of the mechanisms of nonallergic inflammatory reactions (primary irritation) and of the accommodation phenomenon; the development of more sensitive models for predicting adverse responses to marginal irritants; the utilization of modern skills of immunobiology and immunochemistry to elucidate mechanisms of allergic responses; the launching of epidemiologic studies to determine the long term effects of PCBs and associated compounds such as dioxins; and the expansion of research in the mechanisms of skin cancer in relation to susceptibility, genetic and metabolic

  12. Effect of multiple stress factors (thermal, nutritional and pregnancy type) on adaptive capability of native ewes under semi-arid environment.

    PubMed

    Dias E Silva, Tairon Pannunzio; Costa Torreão, Jacira Neves da; Torreão Marques, Carlo Aldrovandi; de Araújo, Marcos Jácome; Bezerra, Leílson Rocha; Kumar Dhanasekaran, Dinesh; Sejian, Veerasamy

    2016-07-01

    This study was conducted to evaluate the effect of multiple stress factors (thermal, nutritional and pregnancy type) on two different native track breeds of ewes as reflected by their adaptive capability under semi-arid environment. The multiple stressor experiment was conducted in twenty-four ewes (12 Santa Inês and 12 Morada Nova ewes). Both heat stress and pregnancy stress was common to all four groups. However, the animals were divided into further two groups within each breed on the basis of nutrition regimen. According the groupings were: Group 1 (Six Santa Ines ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 2 (Six Santa Ines ewes; heat stress; nutrition at 1.5% BW; twin pregnancy); groups Group 3 (Six Morada Nova ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 4 (Six Morada Nova ewes; heat stress; nutrition at 1.5% BW; twin pregnancy). All the animals in the experiment were pregnant. Heat stress was induced by exposing all animals to summer heat stress in outside environment while the nutritional regimen followed was at 0.5% and 1.5% level of body weight (BW) respectively in each breed. The experiment was conducted in a completely randomized design with two breeds, two nutritional treatments and two pregnancy types, 10 repetitions for physiological parameters and six for blood parameters, with repeated measures over time. Physiological parameters (respiratory rate, pulse rate and rectal temperature) were measured with the animals at rest in the morning and afternoon, 0600-0700 and 1300-1400h, respectively, every seven days. Blood samples were collected every 14d for determination of serum glucose, triglycerides, cholesterol, urea and creatinine. We found interaction effect between breed and pregnancy type on respiratory rate and rectal temperature with greater values in Santa Inês ewes than Morada Nova ewes. However, there was no significant fixed effect of pregnancy type and supplementation level on physiological

  13. Quantifying of the Thermal Dynamic Characteristics of the Combustion System for Underground Coal Fire and its Impact on Environment in Xinjiang region, China

    NASA Astrophysics Data System (ADS)

    ZENG, Qiang; Tiyip, Tashpolat; Wuttke, Manfred; NIE, Jing; PU, Yan

    2015-04-01

    Underground Coal fire (UCF) is one disaster associated with coal mining activities around the world. The UCF not only burns up the coal reservoir, but also causes serious environmental problems, such as the pollution to air, the damage to soils, and the contamination to surface and underground water and consequently the health problem to human beings. In the present paper, the authors attempts to quantify the thermal dynamic characteristics of the combustion system for UCF and its impact on environment by modeling, including delineating the physical boundary of UCF zone, modeling of the capacity of the oxygen supply to UCF, modeling the intensity of heat generation from UCF and modeling the process of heat transfer within UCF and its surrounding environment. From this research, results were obtained as follows: First of all, based on the rock control theory, a model was proposed to depict the physical boundary of UCF zone which is important for coal fire research. Secondly, with analyzing the characteristics of air and smoke flow within UCF zone, an air/smoke flow model was proposed and consequently a method was put forward to calculate the capacity of oxygen supply to the UCF. Thirdly, with analyzing the characteristics of coal combustion within UCF zone, a method of calculating the intensity of heat generation from UCF, i.e., the heat source models, was established. Heat transfer with UCF zone includes the heat conductivity within UCF zone, the heat dissipation by radiation from the surface of fire zone, and the heat dissipation by convection as well as the heat loss taken away by mass transport. The authors also made an effort to depict the process of heat transfer by quantitative methods. Finally, an example of Shuixigou coal fire was given to illustrate parts of above models. Further more, UCF's impact on environment, such as the heavy metals contamination to surface soil of fire zone and the characteristics of gaseous pollutants emission from the UCF also was

  14. Adverse reactions to food additives.

    PubMed

    Simon, R A

    1986-01-01

    There are thousands of agents that are intentionally added to the food that we consume. These include preservatives, stabilizers, conditioners, thickeners, colorings, flavorings, sweeteners, antioxidants, etc. etc. Yet only a surprisingly small number have been associated with hypersensitivity reactions. Amongst all the additives, FD&C dyes have been most frequently associated with adverse reactions. Tartrazine is the most notorious of them all; however, critical review of the medical literature and current Scripps Clinic studies would indicate that tartrazine has been confirmed to be at best only occasionally associated with flares of urticaria or asthma. There is no convincing evidence in the literature of reactivity to the other azo or nonazo dyes. This can also be said of BHA/BHT, nitrites/nitrates and sorbates. Parabens have been shown to elicit IgE mediated hypersensitivity reactions when used as pharmaceutical preservatives; however, as with the other additives noted above, ingested parabens have only occasionally been associated with adverse reactions. MSG, the cause of the 'Chinese restaurant syndrome' has only been linked to asthma in one report. Sulfiting agents used primarily as food fresheners and to control microbial growth in fermented beverages have been established as the cause of any where from mild to severe and even fatal reactions in at least 5% of the asthmatic population. Other reactions reported to follow sulfite ingestion include anaphylaxis, gastro intestinal complaints and dermatological eruptions. The prevalence of these non asthmatic reactions is unknown. The mechanism of sulfite sensitive asthma is also unknown but most likely involves hyperreactivity to inhale SO2 in the great majority of cases; however, there are reports of IgE mediated reactions and other sulfite sensitive asthmatics have been found with low levels of sulfite oxidase; necessary to oxidize endogenous sulfite to sulfate. PMID:3302664

  15. 40 CFR 717.12 - Significant adverse reactions that must be recorded.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT RECORDS AND REPORTS OF ALLEGATIONS THAT CHEMICAL SUBSTANCES CAUSE... are not required to record a significant adverse reaction to the environment if the alleged cause of that significant adverse reaction can be directly attributable to an accidental spill or...

  16. 40 CFR 717.12 - Significant adverse reactions that must be recorded.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT RECORDS AND REPORTS OF ALLEGATIONS THAT CHEMICAL SUBSTANCES CAUSE... are not required to record a significant adverse reaction to the environment if the alleged cause of that significant adverse reaction can be directly attributable to an accidental spill or...

  17. 40 CFR 717.12 - Significant adverse reactions that must be recorded.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT RECORDS AND REPORTS OF ALLEGATIONS THAT CHEMICAL SUBSTANCES CAUSE... are not required to record a significant adverse reaction to the environment if the alleged cause of that significant adverse reaction can be directly attributable to an accidental spill or...

  18. 40 CFR 717.12 - Significant adverse reactions that must be recorded.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT RECORDS AND REPORTS OF ALLEGATIONS THAT CHEMICAL SUBSTANCES CAUSE... are not required to record a significant adverse reaction to the environment if the alleged cause of that significant adverse reaction can be directly attributable to an accidental spill or...

  19. 40 CFR 717.12 - Significant adverse reactions that must be recorded.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT RECORDS AND REPORTS OF ALLEGATIONS THAT CHEMICAL SUBSTANCES CAUSE... are not required to record a significant adverse reaction to the environment if the alleged cause of that significant adverse reaction can be directly attributable to an accidental spill or...

  20. Adverse events in healthcare: learning from mistakes.

    PubMed

    Rafter, N; Hickey, A; Condell, S; Conroy, R; O'Connor, P; Vaughan, D; Williams, D

    2015-04-01

    Large national reviews of patient charts estimate that approximately 10% of hospital admissions are associated with an adverse event (defined as an injury resulting in prolonged hospitalization, disability or death, caused by healthcare management). Apart from having a significant impact on patient morbidity and mortality, adverse events also result in increased healthcare costs due to longer hospital stays. Furthermore, a substantial proportion of adverse events are preventable. Through identifying the nature and rate of adverse events, initiatives to improve care can be developed. A variety of methods exist to gather adverse event data both retrospectively and prospectively but these do not necessarily capture the same events and there is variability in the definition of an adverse event. For example, hospital incident reporting collects only a very small fraction of the adverse events found in retrospective chart reviews. Until there are systematic methods to identify adverse events, progress in patient safety cannot be reliably measured. This review aims to discuss the need for a safety culture that can learn from adverse events, describe ways to measure adverse events, and comment on why current adverse event monitoring is unable to demonstrate trends in patient safety. PMID:25078411