WorldWideScience

Sample records for wet heat exposure

  1. Wet heat exposure: a potentially reversible cause of low semen quality in infertile men

    Directory of Open Access Journals (Sweden)

    Shai Shefi

    2007-02-01

    Full Text Available OBJECTIVE: To evaluate the recovery of semen quality in a cohort of infertile men after known hyperthermic exposure to hot tubs, hot baths or whirlpool baths. MATERIALS AND METHODS: A consecutive cohort of infertile men had a history remarkable for wet heat exposure in the forms of hot tubs, Jacuzzi or hot baths. Clinical characteristics and exposure parameters were assessed before exposure was discontinued, and semen parameters analyzed before and after discontinuation of hyperthermic exposure. A significant seminal response to withdrawal of hyperthermia was defined as > 200% increase in the total motile sperm count (TMC = volume x concentration x motile fraction during follow-up after cessation of wet heat exposure. RESULTS: Eleven infertile men (mean age 36.5 years, range 31-44 exposed to hyperthermia were evaluated pre and post-exposure. Five patients (45% responded favorably to cessation of heat exposure and had a mean increase in total motile sperm counts of 491%. This increase was largely the result of a statistically significant increase in sperm motility from a mean of 12% at baseline to 34% post-intervention (p = 0.02. Among non-responders, a smoking history revealed a mean of 5.6 pack-years, compared to 0.11 pack-years among responders. The prevalence of varicoceles was similar in both cohorts. CONCLUSIONS: The toxic effect of hyperthermia on semen quality may be reversible in some infertile men. We observed that the seminal response to exposure elimination varies biologically among individuals and can be profound in magnitude. Among non-responders, other risk factors that could explain a lack of response to elimination of hyperthermia should be considered.

  2. Surface wetting strategy prevents acute heat exposure-induced alterations of hypothalamic stress- and metabolic-related genes in broiler chickens.

    Science.gov (United States)

    Rajaei-Sharifabadi, H; Greene, E; Piekarski, A; Falcon, D; Ellestad, L; Donoghue, A; Bottje, W; Porter, T; Liang, Y; Dridi, S

    2017-03-01

    Heat stress (HS) is devastating to poultry production worldwide, yet its biology and molecular responses are not well defined. Although advances in management strategy have partially alleviated the negative impact of HS, productivity still continues to decline when the ambient temperature rises. Therefore, identifying mechanism-based approaches to decrease HS susceptibility while improving production traits is critical. Recently, we made a breakthrough by applying a surface wetting strategy and showing that it improves growth performance compared with the current conventional cooling system. In the present study, we aimed to further define molecular mechanisms associated with surface wetting in ameliorating HS productivity loss in broilers. Five-week-old broiler chickens were exposed to acute HS (35°C for 2 h) alone or in combination with surface wetting. A control group was maintained at thermoneutral conditions (25°C). Core body temperature (BT) and feed intake were recorded. Blood was collected and hypothalamic tissues (main site involved in the regulation of energy homeostasis) were harvested to determine the expression profile of stress- and metabolic-related genes. Surface wetting prevents HS from increasing BT and plasma corticosterone levels ( < 0.05) and improves feeding and drinking behaviors. At molecular levels, surface wetting blocks the activation of hypothalamic heat shock protein and adenosine monophosphate-activated protein-induced by HS and significantly modulates the expression of feeding-related hypothalamic neuropeptides (agouti-related protein, proopiomelanocortin, orexin, orexin receptor, and leptin receptor). Taken together, our data represent the first evidence that surface wetting alleviates systemic and intracellular stress induced by HS and preserves the intracellular energy status, which, in turn, may result in improved broiler well-being and growth performance.

  3. Energy and heat balance in wet DCT

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)

    2012-11-01

    Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

  4. Effect of Hydrochloric Acid, Mechanical Scarification, Wet Heat ...

    African Journals Online (AJOL)

    Michael Horsfall

    HCL), Wet heat. ABSTRACT; The effect of different ... treatments observed showed 100% for wet heat, 90% for scarification (sand paper) and 70% for HCL of 50% ... the principle constant being a dry season of 5-7 month/year. It may grow in ...

  5. Heat exposure on farmers in northeast Ghana

    Science.gov (United States)

    Frimpong, Kwasi; Van Etten E J, Eddie; Oosthuzien, Jacques; Fannam Nunfam, Victor

    2017-03-01

    Environmental health hazards faced by farmers, such as exposure to extreme heat stress, are a growing concern due to global climate change, particularly in tropical developing countries. In such environments, farmers are considered to be a population at risk of environmental heat exposure. The situation is exacerbated due to their farming methods that involve the use of primitive equipment and hard manual labour conducted in full sunshine under hot and humid conditions. However, there is inadequate information about the extent of heat exposure to such farmers, both at the household and farm levels. This paper presents results from a study assessing environmental heat exposure on rural smallholder farmers in Bawku East, Northern Ghana. From January to December 2013, Lascar USB temperature and humidity sensors and a calibrated Questemp heat stress monitor were deployed to farms and homes of rural farmers at Pusiga in Bawku East to capture farmers' exposure to heat stress in both their living and working environments as they executed regular farming routines. The Lascar sensors have the capability to frequently, accurately and securely measure temperature and humidity over long periods. The Questemp heat stress monitor was placed in the same vicinity and showed strong correlations to Lascar sensors in terms of derived values of wet-bulb globe temperature (WBGT). The WBGT in the working environment of farmers peaked at 33.0 to 38.1 °C during the middle of the day in the rainy season from March to October and dropped to 14.0-23.7 °C in the early morning during this season. A maximum hourly WBGT of 28.9-37.5 °C (March-October) was recorded in the living environment of farmers, demonstrating little relief from heat exposure during the day. With these levels of heat stress, exposed farmers conducting physically demanding outdoor work risk suffering serious health consequences. The sustainability of manual farming practices is also under threat by such high levels of

  6. Effects of sulphuric acid, mechanical scarification and wet heat ...

    African Journals Online (AJOL)

    Effects of different treatment methods on the germination of seeds of Parkia biglobosa (mimosaceae) were carried out. Prior treatment of seeds with sulphuric acid, wet heat and mechanical scarification were found to induce germination of the dormant seeds. These methods could be applied to raise seedlings of the plant for ...

  7. Study of heat exposure in the work environment in Jeddah.

    Science.gov (United States)

    Noweir, M H; Moreb, A A; Bafail, A O

    1996-05-01

    The present work was conducted to define the magnitude of the problem of heat exposure in Jeddah and the role of both the climatic and the industrial factors on the total heat load. Indoor heat exposure was studied in an industrial complex of 5 plants for cables' manufacturing. Outdoor heat exposure was studied in shaded and unshaded operations in Jeddah Islamic Port (JIP). The heat exposure parameters, including air temperature (Ta), wet bulb temperature (Tw), and globe temperature (Tg), as well as the wet bulb globe temperature (WBGT) heat stress index, the relative humidity and the air velocity, were assessed at representative locations. Results of the study indicated that: (a) the levels of heat exposure exceeded the TLV in mostly all the work areas where no air-conditioning is provided. (b) the ambient heat is the factor contributing most to the heat load both in summer and in winter. (c) the radiant heat from furnaces and hot metal rolling and milling adds more heat load to the work environment in specific operations. An outline of a control strategy has been suggested, emphasizing evaporative engineering heat control, work and hygienic practices and auxiliary cooling clothing.

  8. Heat stress exposure of aerial spray pilots.

    Science.gov (United States)

    Gribetz, B; Richter, E D; Krasna, M; Gordon, M

    1980-01-01

    Heat stress (WBGT index) in the cockpits of agricultural spray pilots, and its physiological and subjective effects, were measured for 9 pilots flying in hot weather for a large Israeli aerial spray company. There was concern that heat exposure may be one of the factors involved in a recent increase in the fatal and non-fatal crash rate among Israeli spray pilots. WBGT index calculations were based on sequential cockpit wet bulb, dry bulb, and globe temperatures read when aircraft landed. The WBGT was always above 25 degrees C and exceeded 26.7 degrees C in 70% of observations. In pilots, a daily weight loss of 0.6-1.2% of total body weight was usual, as were rectal temperature increases of 0.5 degrees C. Daily water intakes ranged from less than 100 ml to 2000 ml per workshift. Questionnaires indicated that 42 of 45 pilots said they would drink more fluids if they were provided between flights by ground crews. An unresolved problem was whether conventional threshold standards for heat exposure were set at levels that may produce insidious impairments in pilot psychomotor performance. Cockpit air cooling is suggested as a measure for preventing heat stress in hot climates. However, appropriate filter technologies would be needed to prevent pesticide exposures during flight. Engineering and other measures to prevent heat stress and dehydration should rank high as part of a comprehensive program to protect the health and performance levels of agricultural spray pilots.

  9. Heat index and adjusted temperature as surrogates for wet bulb globe temperature to screen for occupational heat stress.

    Science.gov (United States)

    Bernard, Thomas E; Iheanacho, Ivory

    2015-01-01

    Ambient temperature and relative humidity are readily ava-ilable and thus tempting metrics for heat stress assessment. Two methods of using air temperature and relative humidity to create an index are Heat Index and Adjusted Temperature. The purposes of this article are: (1) to examine how well Heat Index and Adjusted Temperature estimated the wet bulb globe temperature (WBGT) index, and (2) to suggest how Heat Index and Adjusted Temperature can be used to screen for heat stress level. Psychrometric relationships were used to estimate values of actual WBGT for conditions of air temperature, relative humidity, and radiant heat at an air speed of 0.5 m/s. A relationship between Heat Index [°F] and WBGT [°C] was described by WBGT = -0.0034 HI(2) + 0.96 HI - 34. At lower Heat Index values, the equation estimated WBGTs that were ± 2 °C-WBGT around the actual value, and to about ± 0.5 °C-WBGT for Heat Index values > 100 °F. A relationship between Adjusted Temperature [°F] and WBGT [°C] was described by WBGT = 0.45 Tadj - 16. The actual WBGT was between 1 °C-WBGT below the estimated value and 1.4 °C-WBGT above. That is, there was a slight bias toward overestimating WBGT from Adjusted Temperature. Heat stress screening tables were constructed for metabolic rates of 180, 300, and 450 W. The screening decisions were divided into four categories: (1) exposure limit at rest. The authors do not recommend using Heat Index or Adjusted Temperature instead of WBGT, but they may be used to screen for circumstances when a more detailed analysis using WBGT is appropriate. A particular weakness is accounting for radiant heat; and neither air speed nor clothing was considered.

  10. Heat removal (wetting, heat transfer, T/H, secondary circuit, code validation etc.)

    Energy Technology Data Exchange (ETDEWEB)

    Dury, T.; Siman-Tov, M.

    1996-06-01

    This working group provided a comprehensive list of feasibility and uncertainty issues. Most of the issues seem to fall into the `needed but can be worked out` category. They feel these can be worked out as the project develops. A few issues can be considered critical or feasibility issues (that must be proven to be feasible). Those include: (1) Thermal shock and its mitigation (>1 MW); how to inject the He bubbles (if used) - back pressure into He lines - mercury traces in He lines; how to maintain proper bubble distribution and size (static and dynamic; if used); vibrations and fatigue (dynamic); possibility of cavitation from thermal shock. (2) Wetting and/or non-wetting of mercury on containment walls with or without gases and its effect on heat transfer (and materials). (3) Prediction capabilities in the CFD code; bubbles behavior in mercury (if used) - cross stream turbulence (ESS only) - wetting/non-wetting effects. (4) Cooling of beam `windows`; concentration of local heat deposition at center, especially if beam is of parabolic profile.

  11. Quantification of wet-work exposure in nurses using a newly developed wet-work exposure monitor

    NARCIS (Netherlands)

    Visser, Maaike J.; Behroozy, Ali; Verberk, Maarten M.; Semple, Sean; Kezic, Sanja

    2011-01-01

    Occupational contact dermatitis (OCD) is an important work-related disease. A major cause of OCD is 'wet work': frequent contact of the skin with water, soap, detergents, or occlusive gloves. The German guidance TRGS 401 recommends that the duration of wet work (including use of occlusive gloves)

  12. Wet-work Exposure: A Main Risk Factor for Occupational Hand Dermatitis

    Directory of Open Access Journals (Sweden)

    Ali Behroozy

    2014-12-01

    Full Text Available Wet-work can be defined as activities where workers have to immerse their hands in liquids for >2 hours per shift, or wear waterproof (occlusive gloves for a corresponding amount of time, or wash their hands >20 times per shift. This review considers the recent literature on wet-work exposure, and examines wet-work as a main risk factor for developing irritant contact dermatitis of the hands. The aim of this paper is to provide a detailed description of wet-work exposure among specific occupational groups who extensively deal with water and other liquids in their occupations. Furthermore, it highlights the extent and importance of the subsequent adverse health effects caused by exposure to wet-work.

  13. Quantitative analysis of wet-heat inactivation in bovine spongiform encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, Yuichi; Ishikawa, Yukiko; Bo, Xiao; Murayama, Yuichi; Yokoyama, Takashi [Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan); Somerville, Robert A. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, Roslin, Midlothian, EH25 9PS (United Kingdom); Kitamoto, Tetsuyuki [Division of CJD Science and Technology, Department of Prion Research, Center for Translational and Advanced Animal Research on Human Diseases, Tohoku University Graduate School of Medicine, 2-1 Seiryo, Aoba, Sendai 980-8575 (Japan); Mohri, Shirou, E-mail: shirou@affrc.go.jp [Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan)

    2013-03-01

    Highlights: ► We quantitatively analyzed wet-heat inactivation of the BSE agent. ► Infectivity of the BSE macerate did not survive 155 °C wet-heat treatment. ► Once the sample was dehydrated, infectivity was observed even at 170 °C. ► A quantitative PMCA assay was used to evaluate the degree of BSE inactivation. - Abstract: The bovine spongiform encephalopathy (BSE) agent is resistant to conventional microbial inactivation procedures and thus threatens the safety of cattle products and by-products. To obtain information necessary to assess BSE inactivation, we performed quantitative analysis of wet-heat inactivation of infectivity in BSE-infected cattle spinal cords. Using a highly sensitive bioassay, we found that infectivity in BSE cattle macerates fell with increase in temperatures from 133 °C to 150 °C and was not detected in the samples subjected to temperatures above 155 °C. In dry cattle tissues, infectivity was detected even at 170 °C. Thus, BSE infectivity reduces with increase in wet-heat temperatures but is less affected when tissues are dehydrated prior to the wet-heat treatment. The results of the quantitative protein misfolding cyclic amplification assay also demonstrated that the level of the protease-resistant prion protein fell below the bioassay detection limit by wet-heat at 155 °C and higher and could help assess BSE inactivation. Our results show that BSE infectivity is strongly resistant to wet-heat inactivation and that it is necessary to pay attention to BSE decontamination in recycled cattle by-products.

  14. Calculating mass transfer from vertical wet fabrics using a free convection heat transfer correlation

    Energy Technology Data Exchange (ETDEWEB)

    Tafreshi, H. Vahedi; Ercan, E.; Pourdeyhimi, B. [North Carolina State University, Nonwovens Cooperative Research Center, Raleigh, NC (United States)

    2006-07-15

    In this note, the evaporation rate from a vertical wet fabric sheet is calculated using a free convection heat transfer correlation. Chilton-Colburn analogy is used to derive a mass transfer correlation from a heat transfer correlation proposed by Churchill and Chu for free convection from a vertical isothermal plate. The mass transfer rate obtained from this expression has shown excellent agreement with experimental data. (orig.)

  15. The effects of wet heat treatment on the structural and chemical components of Bacillus sporothermodurans spores.

    Science.gov (United States)

    Tabit, Frederick T; Buys, Elna

    2010-06-15

    The objective of this research was to study the rate of structural damage and survival of Bacillus sporothermodurans spores following treatment at high temperatures by determining the amount of Dipicolinic acid (DPA) and soluble protein leakage over time. A reference strain of B. sporothermodurans (DSM 10599) and a South African strain (UP20A) isolated from UHT milk were used. To determine the survival of spores at 130 degrees C, spores were heated for 4, 8 and 12min. To check the viability of spores plate counts were determined, while structural damage was determined using the Transmission Electron Microscopy. The filtrate of the heated spore suspension was analysed for the amount of DPA and soluble protein release due to heating. The amount of DPA released was quantified by HPLC analysis while the amount of soluble protein released from heated spores was quantified using the Bradford method. The log values of spore counts, released DPA and soluble proteins from triplicate experiments were analysed. The results of this study indicate that the inactivation of B. sporothermodurans spores during wet heat treatment is due to the penetration of hot moisture into the spore which then moistens the spore components, and inactivates enzymes, and because of the high water pressure, vital spore components such as proteins and DPA in solution leak out of the spore. Interestingly a vast majority of heated spores were inactivated before a significant amount of DPA was released. This research is the first to determine the effect of high temperature wet heat treatment on the structure of B. sporothermodurans spores and has given an insight regarding the mechanisms of destruction of B. sporothermodurans spores by wet heat. Copyright 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2018-01-01

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

  17. Study of heat exposure during Hajj (pilgrimage).

    Science.gov (United States)

    Noweir, Madbuli H; Bafail, Abdullah O; Jomoah, Ibrahim M

    2008-12-01

    Heat stress presents a main problem to Muslim Hajeej (pilgrims) during Hajj (pilgrimage) season, particularly in summer. Records of the Saudi Ministry of Health show close relation between heat casualties and climatic heat load through consequent Hajj seasons. The present study was conducted to evaluate the climatic heat load in Hajj locations during summer of 1995 as well as just before and during the Hajj season of 1997. Heat measurements including: T (a), T (w), T (g), WBGT, relative humidity and air velocity were conducted through July-September 1995, and on March/April 1997, in 10 Hajj locations at morning, noon, afternoon and night. The highest WBGTs were at Haram court, Ghazzah area and Muna housing area, followed by Arafat areas and Muzdalefah, and the lowest at Azizia area. However, all the WBGTs were considerably higher than the ACGIH-TLV for safe heat exposure, particularly during daytime; meanwhile, heat exposure considerably exceeded the ASHRAE comfort zone at all locations all times. The natural climatic condition is a major contributing factor to the overall heat load; moreover, potentiated by heat dissipated from Hajj activities, including Hajeej crowds, human activities, and the vehicles' masses exhaust. This situation is further synergized by some pilgrims' misbehavior (e.g. living in open sunny areas, using vehicles without roofs) and lack of awareness of the seriousness of heat exposure among them. An outline for a control strategy has been suggested based on planting open areas of Arafat and Muna, provision of air conditioned housing and tents in Muna, segregation of pedestrians from vehicles and their provision of shaded roads and rest areas, establishing more water spatters in Arafat and Muna, checking the performance of large vehicles before issuing their permits for operation during Hajj, providing vehicles parking isolated areas away from Hajeej tents, provision of ample amounts of quality drinking water in all Hajj locations, provision of

  18. Air-side performance of a micro-channel heat exchanger in wet surface conditions

    Directory of Open Access Journals (Sweden)

    Srisomba Raviwat

    2017-01-01

    Full Text Available The effects of operating conditions on the air-side heat transfer, and pressure drop of a micro-channel heat exchanger under wet surface conditions were studied experimentally. The test section was an aluminum micro-channel heat exchanger, consisting of a multi-louvered fin and multi-port mini-channels. Experiments were conducted to study the effects of inlet relative humidity, air frontal velocity, air inlet temperature, and refrigerant temperature on air-side performance. The experimental data were analyzed using the mean enthalpy difference method. The test run was performed at relative air humidities ranging between 45% and 80%; air inlet temperature ranges of 27, 30, and 33°C; refrigerant-saturated temperatures ranging from 18 to 22°C; and Reynolds numbers between 128 and 166. The results show that the inlet relative humidity, air inlet temperature, and the refrigerant temperature had significant effects on heat transfer performance and air-side pressure drop. The heat transfer coefficient and pressure drop for the micro-channel heat exchanger under wet surface conditions are proposed in terms of the Colburn j factor and Fanning f factor.

  19. Heat treated twin wire arc spray AISI 420 coatings under dry and wet abrasive wear

    Science.gov (United States)

    Rodriguez, E.; González, M. A.; Monjardín, H. R.; Jimenez, O.; Flores, M.; Ibarra, J.

    2017-11-01

    The influence of applying two different heat treatments such as: deep cryogenic and tempering on dry/wet abrasive wear resistance of twin wire arc spray martensitic AISI 420 coatings was evaluated by using a modified rubber wheel type test apparatus. A load dependency was observed on the abrasive wear rate behavior of both; dry and wet tests. Three body (rolling) and two body (sliding) wear mechanisms were identified in dry conditions, prevailing rolling at lower and higher loads. However, at higher loads, more presence of grooving and pits formation was observed. Coatings tempered at 205 °C/1 h displayed better wear resistance than cryogenic treated ones. A change in wear mechanism between dry and wet conditions was observed; two body wear mechanism predominated respect to three body. In both; dry and wet conditions the microstructure (several inter-splat oxides) as well as strain and residual stress promotes brittle material removal which was more evident in cryogenic and as-sprayed samples during dry test and at higher loads in wet conditions.

  20. Surface Resistance of Jute Fibre/Polylactic Acid Biocomposite to Wet Heat

    Science.gov (United States)

    Zandvliet, Clio; Bandyopadhyay, N. R.; Ray, Dipa

    2016-04-01

    Jute fibre/polylactic acid (PLA) composite is of special interest because both resin and reinforcement come from renewable resources. Thus, it could be a more eco-friendly alternative to glass fibre composite [1] and to conventional wood-based panels made with phenol-formaldehyde resin which present many drawbacks for the workers and the environment [2]. Yet the water affinity of the natural fibres, the susceptibility of PLA towards hydrolysis and the low glass transition of the PLA raise a question about the surface resistance of such composites to wet heat in service condition for a furniture application [3]. In this work, the surface resistance of PLA/jute composite alone and with two different varnishes are investigated in regard to an interior application following the standard test method in accordance to BS EN 18721:2009: "Furniture: assessment of surface resistance to wet heat". It is compared to two common wood based panels, plywood and hardboard. After test, the composite material surface is found to be more affected than plywood and hardboard, but it becomes resistant to wet heat when a layer of biosourced varnish or petrol-based polyurethane varnish are applied on the surface.

  1. Response and sensitivity of lipid related molecular structure to wet and dry heating in Canola tissue

    Science.gov (United States)

    Abeysekara, Saman; Samadi; Yu, Peiqiang

    2012-05-01

    Heat treatments are used to manipulate nutrient utilization, availability and functional properties. The objective of this study was to characterize any molecular level changes of the functional groups associated with lipid structure in canola (Brassica) seed, as affected during the wet and dry heat treatment processes using molecular spectroscopy. The parameters included lipid CH3 asymmetric (ca. 2970-2946 cm-1), CH2 asymmetric (ca. 2945-2880 cm-1), CH3 symmetric (ca. 2881-2864 cm-1) and CH2 symmetric (ca. 2864-2770 cm-1) functional groups, lipid carbonyl Cdbnd O ester group (ca. 1774-1711 cm-1), lipid unsaturation group (CH attached to C-C) (ca. 3007 cm-1) as well as their ratios. Hierarchical cluster analysis (CLA) and principal components analysis (PCA) were conducted to identify molecular spectral differences. Raw canola seeds were used for the control or autoclaved at 120 °C for 1 h (HT-1: wet heating) or dry roasted at 120 °C for 1 h (HT-2: dry heating). Molecular spectral analysis of lipid functional group ratios were not significantly changed (P > 0.05) in the CH2 asymmetric to CH3 asymmetric stretching band peak intensity ratios for canola seed. Both wet (HT-1) and dry heating method (HT-2) had no significant effect (P > 0.05) on lipid carbonyl Cdbnd O ester group and lipid unsaturation group (CH attached to Cdbnd C). Multivariate molecular spectral analyses, CLA and PCA, were unable to make distinctions between the different treatment original spectra at the CH3 and CH2 asymmetric and symmetric region (ca. 2992-2770 cm-1), unsaturated lipids band region (ca. 3025-2993 cm-1) and lipid carbonyl Cdbnd O ester band region (ca. 1774-1711 cm-1). The results indicated that both dry and wet heating of given intense had no impact to the molecular spectrum in lipid related functional groups of canola seed, and was not strong enough to elicit heat-induced changes in lipid conformation.

  2. Pain Relief with Wet Cupping Therapy in Rats is Mediated by Heat Shock Protein 70 and ?-Endorphin

    OpenAIRE

    Imam Subadi; Boya Nugraha; Hening Laswati; Harjanto Josomuljono

    2017-01-01

    Background: Wet cupping therapy is a complementary therapy in pain management. The mechanism of this therapy, however, needs further elucidation. Cells injured by wet cupping therapy seem to stimulate the expression of heat shock protein 70 (HSP70). Its benefit in pain reduction could be mediated by the expression of ß-endorphin. This study aimed at determining the correlation between HSP70 and ß-endorphin after wet cupping therapy. Methods: Sixteen male Wistar rats were divided into contr...

  3. Review of thermo-physical properties, wetting and heat transfer characteristics of nanofluids and their applicability in industrial quench heat treatment

    Directory of Open Access Journals (Sweden)

    Ramesh Gopalan

    2011-01-01

    Full Text Available Abstract The success of quenching process during industrial heat treatment mainly depends on the heat transfer characteristics of the quenching medium. In the case of quenching, the scope for redesigning the system or operational parameters for enhancing the heat transfer is very much limited and the emphasis should be on designing quench media with enhanced heat transfer characteristics. Recent studies on nanofluids have shown that these fluids offer improved wetting and heat transfer characteristics. Further water-based nanofluids are environment friendly as compared to mineral oil quench media. These potential advantages have led to the development of nanofluid-based quench media for heat treatment practices. In this article, thermo-physical properties, wetting and boiling heat transfer characteristics of nanofluids are reviewed and discussed. The unique thermal and heat transfer characteristics of nanofluids would be extremely useful for exploiting them as quench media for industrial heat treatment.

  4. Experimental evaluation of dry/wet air-cooled heat exchangers. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, S.G.; Gruel, R.L.; Huenefeld, J.C.; Eschbach, E.J.; Johnson, B.M.; Kreid, D.K.

    1982-08-01

    The ultimate goal of this project was to contribute to the development of improved cooling facilities for power plants. Specifically, the objective during FY-81 was to experimentally determine the thermal performance and operating characteristics of an air-cooled heat exchanger surface manufactured by the Unifin Company. The performance of the spiral-wound finned tube surface (Unifin) was compared with two inherently different platefin surfaces (one developed by the Trane Co. and the other developed by the HOETERV Institute) which were previously tested as a part of the same continuing program. Under dry operation the heat transfer per unit frontal area per unit inlet temperature difference (ITD) of the Unifin surface was 10% to 20% below that of the other two surfaces at low fan power levels. At high fan power levels, the performances of the Unifin and Trane surfaces were essentially the same, and 25% higher than the HOETERV surface. The design of the Unifin surface caused a significantly larger air-side pressure drop through the heat exchanger both in dry and deluge operation. Generally higher overall heat transfer coefficients were calculated for the Unifin surface under deluged operation. They ranged from 2.0 to 3.5 Btu/hr-ft/sup 2/-/sup 0/F as compared to less than 2.0 Btu hr-ft/sup 2/-/sup 0/F for the Trane and HOETERV surfaces under similar conditions. The heat transfer enhancement due to the evaporative cooling effect was also measureably higher with the Unifin surface as compared to the Trane surface. This can be primarily attributed to the better wetting characteristics of the Unifin surface. If the thermal performance of the surfaces are compared at equal face velocities, the Unifin surface is as much as 35% better. This method of comparison accounts for the wetting characteristics while neglecting the effect of pressure drop. Alternatively the surfaces when compared at equal pressure drop essentially the same thermal performance.

  5. Wage Differentials between Heat-Exposure Risk and No Heat-Exposure Risk Groups

    Directory of Open Access Journals (Sweden)

    Donghyun Kim

    2017-06-01

    Full Text Available The goal of this study is to investigate the wage differential between groups of workers who are exposed to heat and those who are not. Workers in the heat-exposure risk group are defined as workers who work in conditions that cause them to spend more than 25% of their work hours at high temperatures. To analyze the wage differential, the Blinder-Oaxaca and Juhn-Murphy-Pierce methods were applied to Korea Working Condition Survey data. The results show that the no heat-exposure risk group received higher wages. In most cases, this can be interpreted as the endowment effect of human capital. As a price effect that lowers the endowment effect, the compensating differential for the heat-exposure risk group was found to be 1%. Moreover, education level, work experience, and employment status counteracted the compensating differentials for heat-exposure risks. A comparison of data sets from 2011 and 2014 shows that the increasing wage gap between the two groups was not caused by systematic social discrimination factors. This study suggests that wage differential factors can be modified for thermal environmental risks that will change working conditions as the impact of climate change increases.

  6. Opportunities and Challenges for Personal Heat Exposure Research.

    Science.gov (United States)

    Kuras, Evan R; Richardson, Molly B; Calkins, Miriam M; Ebi, Kristie L; Hess, Jeremy J; Kintziger, Kristina W; Jagger, Meredith A; Middel, Ariane; Scott, Anna A; Spector, June T; Uejio, Christopher K; Vanos, Jennifer K; Zaitchik, Benjamin F; Gohlke, Julia M; Hondula, David M

    2017-08-01

    Environmental heat exposure is a public health concern. The impacts of environmental heat on mortality and morbidity at the population scale are well documented, but little is known about specific exposures that individuals experience. The first objective of this work was to catalyze discussion of the role of personal heat exposure information in research and risk assessment. The second objective was to provide guidance regarding the operationalization of personal heat exposure research methods. We define personal heat exposure as realized contact between a person and an indoor or outdoor environment that poses a risk of increases in body core temperature and/or perceived discomfort. Personal heat exposure can be measured directly with wearable monitors or estimated indirectly through the combination of time-activity and meteorological data sets. Complementary information to understand individual-scale drivers of behavior, susceptibility, and health and comfort outcomes can be collected from additional monitors, surveys, interviews, ethnographic approaches, and additional social and health data sets. Personal exposure research can help reveal the extent of exposure misclassification that occurs when individual exposure to heat is estimated using ambient temperature measured at fixed sites and can provide insights for epidemiological risk assessment concerning extreme heat. Personal heat exposure research provides more valid and precise insights into how often people encounter heat conditions and when, where, to whom, and why these encounters occur. Published literature on personal heat exposure is limited to date, but existing studies point to opportunities to inform public health practice regarding extreme heat, particularly where fine-scale precision is needed to reduce health consequences of heat exposure. https://doi.org/10.1289/EHP556.

  7. Two-phase distribution in the vertical flow line of a domestic wet central heating system

    Directory of Open Access Journals (Sweden)

    Ge Y.T.

    2013-04-01

    Full Text Available The theoretical and experimental aspects of bubble distribution in bubbly two-phase flow are reviewed in the context of the micro bubbles present in a domestic gas fired wet central heating system. The latter systems are mostly operated through the circulation of heated standard tap water through a closed loop circuit which often results in water supersaturated with dissolved air. This leads to micro bubble nucleation at the primary heat exchanger wall, followed by detachment along the flow. Consequently, a bubbly two-phase flow characterises the flow line of such systems. The two-phase distribution across the vertical and horizontal pipes was measured through a consideration of the volumetric void fraction, quantified through photographic techniques. The bubble distribution in the vertical pipe in down flow conditions was measured to be quasi homogenous across the pipe section with a negligible reduction in the void fraction at close proximity to the pipe wall. Such a reduction was more evident at lower bulk fluid velocities.

  8. Air-side performance evaluation of three types of heat exchangers in dry, wet and periodic frosting conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ping [Zhejiang Vocational College of Commerce, Hangzhou, Binwen Road 470 (China); Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign 1206 West Green Street, Urbana, IL 61801 (United States); Hrnjak, P.S. [Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign 1206 West Green Street, Urbana, IL 61801 (United States)

    2009-08-15

    The performances of three types of heat exchangers that use the louver fin geometry: (1) parallel flow parallel fin with extruded flat tubes heat exchanger (PF{sup 2}), (2) parallel flow serpentine fin with extruded flat tubes heat exchanger (PFSF) and (3) round tube wave plate fin heat exchanger (RTPF) have been experimentally studied under dry, wet and frost conditions and results are presented. The parameters quantified include air-side pressure drop, water retention on the surface of the heat exchanger, capacity and overall heat transfer coefficient for air face velocity 0.9, 2 and 3 m/s, air humidity 70% and 80% and different orientations. The performances of three types of heat exchanger are compared and the results obtained are presented. The condensate drainage behavior of the air-side surface of these three heat exchanger types was studied using both the dip testing method and wind tunnel experiment. (author)

  9. The Effects of Wet Compression by the Electronic Expansion Valve Opening on the Performance of a Heat Pump System

    Directory of Open Access Journals (Sweden)

    Kyoungjin Seong

    2017-03-01

    Full Text Available In this study, by controlling the Electronic Expansion Valve opening, the influence of wet compression on a heat pump system was experimentally investigated in different heating conditions. The results demonstrate that the discharge temperature decreased and the mass flow rate increased, due to quality of the rising liquid droplets. It was also found that the heating capacity and power input of wet compression increased more than that of dry compression, with a superheat of 10 °C. The maximum COP (Coefficient of Performance exists at a specific quality of ca. 0.94 to 0.90, as the power input in the region of wet compression is proportionally larger than the increase in the heating capacity, according to the decreasing quality. When the Entering Water Temperature of the Outdoor Heat Exchanger was 10 °C, 5 °C, and 0 °C, the COP increased by a maximum of ca. 12.4%, 10.6%, and 10.2%, respectively, in comparison to the superheat of 10 °C. In addition, the superheat at the discharge line is proposed as a proper controlling parameter to adjust the quality at the suction line, by varying the opening of the expansion valve during wet compression.

  10. Temperature and humidity based projections of a rapid rise in global heat stress exposure during the 21st century

    Science.gov (United States)

    Coffel, Ethan D.; Horton, Radley M.; de Sherbinin, Alex

    2018-01-01

    As a result of global increases in both temperature and specific humidity, heat stress is projected to intensify throughout the 21st century. Some of the regions most susceptible to dangerous heat and humidity combinations are also among the most densely populated. Consequently, there is the potential for widespread exposure to wet bulb temperatures that approach and in some cases exceed postulated theoretical limits of human tolerance by mid- to late-century. We project that by 2080 the relative frequency of present-day extreme wet bulb temperature events could rise by a factor of 100–250 (approximately double the frequency change projected for temperature alone) in the tropics and parts of the mid-latitudes, areas which are projected to contain approximately half the world’s population. In addition, population exposure to wet bulb temperatures that exceed recent deadly heat waves may increase by a factor of five to ten, with 150–750 million person-days of exposure to wet bulb temperatures above those seen in today’s most severe heat waves by 2070–2080. Under RCP 8.5, exposure to wet bulb temperatures above 35 °C—the theoretical limit for human tolerance—could exceed a million person-days per year by 2080. Limiting emissions to follow RCP 4.5 entirely eliminates exposure to that extreme threshold. Some of the most affected regions, especially Northeast India and coastal West Africa, currently have scarce cooling infrastructure, relatively low adaptive capacity, and rapidly growing populations. In the coming decades heat stress may prove to be one of the most widely experienced and directly dangerous aspects of climate change, posing a severe threat to human health, energy infrastructure, and outdoor activities ranging from agricultural production to military training.

  11. Physiological effects after exposure to heat : A brief literature review

    NARCIS (Netherlands)

    Bogerd, C.P.; Daanen, H.A.M.

    2011-01-01

    Many employees are exposed to heat stress during their work. Although the direct effects of heat are well reported, the long term physiological effects occurring after heat exposure are hardly described. The present manuscript addresses these issues in the form of a brief literature review. Repeated

  12. Pain Relief with Wet Cupping Therapy in Rats is Mediated by Heat Shock Protein 70 and ß-Endorphin.

    Science.gov (United States)

    Subadi, Imam; Nugraha, Boya; Laswati, Hening; Josomuljono, Harjanto

    2017-07-01

    Wet cupping therapy is a complementary therapy in pain management. The mechanism of this therapy, however, needs further elucidation. Cells injured by wet cupping therapy seem to stimulate the expression of heat shock protein 70 (HSP70). Its benefit in pain reduction could be mediated by the expression of ß-endorphin. This study aimed at determining the correlation between HSP70 and ß-endorphin after wet cupping therapy. Sixteen male Wistar rats were divided into control (CG; n=8) and treatment (TG; n=8) groups. The rats in both groups were injected with complete Freund's adjuvant (CFA) at the footpad. In the TG, wet cupping therapy was done at the left and right paralumbar regions 48 hours after the CFA injection. Twenty-four hours after therapy, the hot plate test was done to assess pain threshold. Thereafter, immunohistochemistry from the skin subjected to wet cupping therapy was conducted for HSP70 and ß-endorphin. The expression of HSP70 was significantly higher in the keratinocytes of the TG (20.25±3.53; Pcupping therapy was significantly higher in the TG (22.81±6.34 s; P=0.003) than in the CG (11.78±3.56 s). The benefit of wet cupping therapy in terms of pain reduction in rats could be mediated by the expression of HSP70 and ß-endorphin.

  13. An experimental study of heat pipe thermal management system with wet cooling method for lithium ion batteries

    Science.gov (United States)

    Zhao, Rui; Gu, Junjie; Liu, Jie

    2015-01-01

    An effective battery thermal management (BTM) system is required for lithium-ion batteries to ensure a desirable operating temperature range with minimal temperature gradient, and thus to guarantee their high efficiency, long lifetime and great safety. In this paper, a heat pipe and wet cooling combined BTM system is developed to handle the thermal surge of lithium-ion batteries during high rate operations. The proposed BTM system relies on ultra-thin heat pipes which can efficiently transfer the heat from the battery sides to the cooling ends where the water evaporation process can rapidly dissipate the heat. Two sized battery packs, 3 Ah and 8 Ah, with different lengths of cooling ends are used and tested through a series high-intensity discharges in this study to examine the cooling effects of the combined BTM system, and its performance is compared with other four types of heat pipe involved BTM systems and natural convection cooling method. A combination of natural convection, fan cooling and wet cooling methods is also introduced to the heat pipe BTM system, which is able to control the temperature of battery pack in an appropriate temperature range with the minimum cost of energy and water spray.

  14. Weakening and Shifting of the Saharan Heat Low Circulation During Wet Years of the West African Monsoon

    CERN Document Server

    Shekhar, Ravi

    2016-01-01

    The correlation between increased West African monsoon rainfall and anomalously low surface pressure over the Sahara is well established in observations and global climate models, and has been interpreted as a strengthening of the Saharan Heat Low (SHL) during wet monsoon years. This study uses two atmospheric reanalysis datasets to examine interannual variability of Sahel rainfall and the shallow Saharan Heat Low circulation, which consists of the near surface SHL and the Saharan High in the lower mid-troposphere. During wet Sahel years, the SHL circulation shifts poleward, producing a drop in low-level geopotential height and surface pressure over the Sahara. Statistically removing the effect of the poleward shift from the low-level geopotential eliminates significant correlations between this geopotential and Sahel precipitation. As the SHL circulation shifts poleward, its mid-tropospheric divergent outflow decreases, indicating a weakening of its overturning mass flux. The poleward shift and weakening of ...

  15. Exertional heat illness and acute injury related to ambient wet bulb globe temperature.

    Science.gov (United States)

    Garzon-Villalba, Ximena P; Mbah, Alfred; Wu, Yougui; Hiles, Michael; Moore, Hanna; Schwartz, Skai W; Bernard, Thomas E

    2016-12-01

    The Deepwater Horizon disaster cleanup effort provided an opportunity to examine the effects of ambient thermal conditions on exertional heat illness (EHI) and acute injury (AI). The outcomes were daily person-based frequencies of EHI and AI. Exposures were maximum estimated WBGT (WBGTmax) and severity. Previous day's cumulative effect was assessed by introducing previous day's WBGTmax into the model. EHI and AI were higher in workers exposed above a WBGTmax of 20°C (RR 1.40 and RR 1.06/°C, respectively). Exposures above 28°C-WBGTmax on the day of the EHI and/or the day before were associated with higher risk of EHI due to an interaction between previous day's environmental conditions and the current day (RRs from 1.0-10.4). The risk for EHI and AI were higher with increasing WBGTmax. There was evidence of a cumulative effect from the prior day's WBGTmax for EHI. Am. J. Ind. Med. 59:1169-1176, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Heat exposure, cardiovascular stress and work productivity in rice harvesters in India: implications for a climate change future.

    Science.gov (United States)

    Sahu, Subhashis; Sett, Moumita; Kjellstrom, Tord

    2013-01-01

    Excessive workplace heat exposures create well-known risks of heat stroke, and it limits the workers' capacity to sustain physical activity. There is very limited evidence available on how these effects reduce work productivity, while the quantitative relationship between heat and work productivity is an essential basis for climate change impact assessments. We measured hourly heat exposure in rice fields in West Bengal and recorded perceived health problems via interviews of 124 rice harvesters. In a sub-group (n = 48) heart rate was recorded every minute in a standard work situation. Work productivity was recorded as hourly rice bundle collection output. The hourly heat levels (WBGT = Wet Bulb Globe Temperature) were 26-32°C (at air temperatures of 30-38°C), exceeding international standards. Most workers reported exhaustion and pain during work on hot days. Heart rate recovered quickly at low heat, but more slowly at high heat, indicating cardiovascular strain. The hourly number of rice bundles collected was significantly reduced at WBGT>26°C (approximately 5% per°C of increased WBGT). We conclude that high heat exposure in agriculture caused heat strain and reduced work productivity. This reduction will be exacerbated by climate change and may undermine the local economy.

  17. Effect of wet bulb depression on heat sterilization time of slash pine lumber

    Science.gov (United States)

    William T. Simpson

    For international trade, heat sterilization of wood products is often required to prevent the spread of insects and pathogens. Application of heat sterilization requires estimates of the time necessary to heat the center of the wood configuration to the temperature required to kill the insect or other pest. The nature of the heating medium was found to have a...

  18. Physical modelling of globe and natural wet bulb temperatures to predict WBGT heat stress index in outdoor environments.

    Science.gov (United States)

    Gaspar, Adélio R; Quintela, Divo A

    2009-05-01

    The present paper describes a physical model that estimates the globe and the natural wet bulb temperatures from the main parameters generally recorded at meteorological weather stations, in order to predict the wet bulb globe temperature (WBGT) heat stress index for outdoor environments. The model is supported by a thermal analysis of the globe and the natural wet bulb temperature sensors. The results of simultaneous measurements of the WBGT and climatological parameters (solar radiation, wind velocity, humidity, etc.) are presented and used to validate the model. The final comparison between calculated and measured values shows a good agreement with the experimental data, with a maximum absolute deviation of 2.8% for the globe temperature and 2.6% for the natural wet bulb temperature and the WBGT index. The model is applied to the design reference year for Coimbra, Portugal, in order to illustrate its preventative capabilities from a practical point of view. The results clearly show that during the summer there is a critical daily period (1200-1600 hours, local standard time) during which people working outdoors should not be allowed to perform their normal activities.

  19. Occupational exposure in small and medium scale industry with specific reference to heat and noise.

    Science.gov (United States)

    Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, Kishore Kumar

    2010-01-01

    This study was undertaken to assess heat and noise exposure and occupational safety practices in small and medium scale casting and forging units (SMEs) of Northern India. We conducted personal interviews of 350 male workers of these units through a comprehensive questionnaire and collected information on heat and noise exposure, use of protective equipment, sweat loss and water intake, working hour. The ambient wet bulb globe temperature (WBGT index) was measured using quest temp 34/36o area heat stress monitor. A-weighted Leq ambient noise was measured using a quest sound level meter "ANSI SI. 43-1997 (R 2002) type-1 model SOUNDPRO SE/DL". We also incorporated OSHA norms for hearing conservation which include - an exchange rate of 5dB(A), criterion level at 90dB(A), criterion time of eight hours, threshold level is equal to 80dB(A), upper limit is equal to 140dB(A) and with F/S response rate. Results of the study revealed that occupational heat exposure in melting, casting, forging and punching sections is high compared to ACGIH/NIOSH norms. Ambience noise in various sections like casting / molding, drop forging, cutting presses, punching, grinding and barreling process was found to be more than 90dB(A). About 95% of the workers suffered speech interference where as high noise annoyance was reported by only 20%. Overall, 68% workers were not using any personal protective equipment (PPE). The study concluded that the proportion of SME workers exposed to high level heat stress and noise (60 - 72 hrs/week) is high. The workers engaged in forging and grinding sections are more prone to noise induced hearing loss (NIHL) at higher frequencies as compared to workers of other sections. It is recommended that there is a strong need to implement the standard of working hours as well as heat stress and noise control measures.

  20. Occupational exposure in small and medium scale industry with specific reference to heat and noise

    Directory of Open Access Journals (Sweden)

    Lakhwinder Pal Singh

    2010-01-01

    Full Text Available This study was undertaken to assess heat and noise exposure and occupational safety practices in small and medium scale casting and forging units (SMEs of Northern India. We conducted personal interviews of 350 male workers of these units through a comprehensive questionnaire and collected information on heat and noise exposure, use of protective equipment, sweat loss and water intake, working hour. The ambient wet bulb globe temperature (WBGT index was measured using quest temp 34/36o area heat stress monitor. A-weighted Leq ambient noise was measured using a quest sound level meter "ANSI SI. 43-1997 (R 2002 type-1 model SOUNDPRO SE/DL". We also incorporated OSHA norms for hearing conservation which include - an exchange rate of 5dB(A, criterion level at 90dB(A, criterion time of eight hours, threshold level is equal to 80dB(A, upper limit is equal to 140dB(A and with F/S response rate. Results of the study revealed that occupational heat exposure in melting, casting, forging and punching sections is high compared to ACGIH/NIOSH norms. Ambience noise in various sections like casting / molding, drop forging, cutting presses, punching, grinding and barreling process was found to be more than 90dB(A. About 95% of the workers suffered speech interference where as high noise annoyance was reported by only 20%. Overall, 68% workers were not using any personal protective equipment (PPE. The study concluded that the proportion of SME workers exposed to high level heat stress and noise (60 - 72 hrs/week is high. The workers engaged in forging and grinding sections are more prone to noise induced hearing loss (NIHL at higher frequencies as compared to workers of other sections. It is recommended that there is a strong need to implement the standard of working hours as well as heat stress and noise control measures.

  1. Heat index trends and climate change implications for occupational heat exposure in Da Nang, Vietnam

    Directory of Open Access Journals (Sweden)

    Sarah Opitz-Stapleton

    2016-09-01

    Full Text Available Occupational extreme heat exposure can lead to a number of detrimental heat-health impacts on workers. Excessive night-time temperatures following hot days do not allow for workers to recover and can compound work heat-health impacts. A number of heat indices have been developed to estimate thermal comfort – how hot it feels – based on meteorological, physiological, and working conditions. We investigated potential changes in day and night-time ambient temperatures and heat indices for Da Nang, Vietnam over the period 2020–2049 when compared with 1970–1999 after downscaling daily minimum and maximum temperatures and humidity variables from six CMIP5 climate models. Two heat indices were employed, the U.S. National Weather Service Heat Index for day and the indoor Apparent Temperature for night. The Vietnam Ministry of Health (MOH sets thermal comfort thresholds for particular workloads and rates. By 2050, daytime heat index values breach the average 32 °C MOH threshold for light work nearly continuously during the months of April to October. The number of nights per annum in which the heat index exceeds 28 °C is likely to range between 131 and 170 nights per year. Occupational heat exposure in Da Nang for outdoor workers or indoor workers without adequate ventilation, breaks or other cooling and heat precautionary and treatment measures will be exacerbated by climate change.

  2. Mechanisms responsible for the effect of wet bulb depression on heat sterilization of slash pine lumber

    Science.gov (United States)

    William T. Simpson

    2003-01-01

    Heat sterilization is often required to prevent spread of insects and pathogens in wood products in international trade. Heat sterilization requires estimating the time necessary for the center of the wood configuration to reach the temperature required to kill insects or pathogens. In these experiments on 1.0- and 1.8-in.- (25- and 46-mm-) thick slash pine, heating...

  3. Pain Relief with Wet Cupping Therapy in Rats is Mediated by Heat Shock Protein 70 and ß-Endorphin

    Directory of Open Access Journals (Sweden)

    Imam Subadi

    2017-07-01

    Full Text Available Background: Wet cupping therapy is a complementary therapy in pain management. The mechanism of this therapy, however, needs further elucidation. Cells injured by wet cupping therapy seem to stimulate the expression of heat shock protein 70 (HSP70. Its benefit in pain reduction could be mediated by the expression of ß-endorphin. This study aimed at determining the correlation between HSP70 and ß-endorphin after wet cupping therapy. Methods: Sixteen male Wistar rats were divided into control (CG; n=8 and treatment (TG; n=8 groups. The rats in both groups were injected with complete Freund’s adjuvant (CFA at the footpad. In the TG, wet cupping therapy was done at the left and right paralumbar regions 48 hours after the CFA injection. Twenty-four hours after therapy, the hot plate test was done to assess pain threshold. Thereafter, immunohistochemistry from the skin subjected to wet cupping therapy was conducted for HSP70 and ß-endorphin. Results: The expression of HSP70 was significantly higher in the keratinocytes of the TG (20.25±3.53; P<0.001 than in the keratinocytes of the CG (10.50±2.44; P<0.001. The expression of ß-endorphin was significantly higher in the keratinocytes of the TG (22.37±3.52; P<0.001 than in the keratinocytes of the CG (5.12±1.72; P<0.001. The results also revealed a high correlation between HSP70 and ß-endorphin (β=0.864; P<0.001. Pain threshold after wet cupping therapy was significantly higher in the TG (22.81±6.34 s; P=0.003 than in the CG (11.78±3.56 s. Conclusions: The benefit of wet cupping therapy in terms of pain reduction in rats could be mediated by the expression of HSP70 and ß-endorphin.

  4. Non-evaporative effects of a wet mid layer on heat transfer through protective clothing

    NARCIS (Netherlands)

    Bröde, P.; Havenith, G.; Wang, X.; Candas, V.; Hartog, E.A. den; Griefahn, B.; Holmér, I.; Kuklane, K.; Meinander, H.; Nocker, W.; Richards, M.

    2008-01-01

    In order to assess the non-evaporative components of the reduced thermal insulation of wet clothing, experiments were performed with a manikin and with human subjects in which two layers of underwear separated by an impermeable barrier were worn under an impermeable overgarment at 20°C, 80% RH and

  5. Sporulation dynamics and spore heat resistance in wet and dry biofilms of Bacillus cereus

    NARCIS (Netherlands)

    Hayrapetyan, Hasmik; Abee, Tjakko; Nierop Groot, Masja

    2016-01-01

    Environmental conditions and growth history can affect the sporulation process as well as subsequent properties of formed spores. The sporulation dynamics was studied in wet and air-dried biofilms formed on stainless steel (SS) and polystyrene (PS) for Bacillus cereus ATCC 10987 and the

  6. Estimating population heat exposure and impacts on working people in conjunction with climate change.

    Science.gov (United States)

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

    2017-08-01

    Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the

  7. Estimating population heat exposure and impacts on working people in conjunction with climate change

    Science.gov (United States)

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

    2017-08-01

    Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the southern

  8. Rosacea and exposure to tandoor heat: Is there an association?

    Science.gov (United States)

    Ozkol, Hatice U; Calka, Omer; Akdeniz, Necmettin; Baskan, Elife; Ozkol, Halil

    2015-12-01

    Particularly in eastern and southeastern regions of Turkey, women use tandoor ovens to bake bread and as a result are exposed to excessive heat. Exposure to heat for long periods may lead to the initiation or exacerbation of rosacea. The aim of this study was to investigate whether there is a relationship between exposure to heat from a tandoor and rosacea. A total of 350 female patients with various dermatological diseases were included in this study. These patients were divided into two groups comprising a control group and a group of tandoor users. Subjects in both the control and tandoor-user groups were screened to identify clinical and other characteristics, and symptoms and findings of rosacea and other dermatological disorders. The frequency of rosacea was significantly (P rosacea, were also significantly (P rosacea. Further studies including higher numbers of patients are required to confirm our results. © 2015 The International Society of Dermatology.

  9. Composition of sweat of the horse during prolonged epinephrine (adrenaline) infusion, heat exposure, and exercise.

    Science.gov (United States)

    Kerr, M G; Snow, D H

    1983-08-01

    Temporal changes in sweat composition were studied in 4 horses during epinephrine (adrenaline) infusion (0.13 to 0.31 micrograms/kg/min for 3 hours), heat exposure (41 C, [33 C wet bulb] for 5 to 6 hours), and exercise (16 to 18 km/hr for 58 to 80 km). Four ponies also were studied during heat exposure. Sweat produced by each of the stimuli was hypertonic for Na+, K+, and Cl-. These electrolyte concentrations remained constant during the central period of the experiments, with changes occurring near the beginning and toward the end. The Na+ was significantly higher and K+ significantly lower in epinephrine-induced sweat than in heat-induced sweat, and the pattern of change in sweat Na/K ratio varied among the 3 stimuli. The Ca2+ concentration decreased with time and was hypotonic after 15 minutes of epinephrine-induced sweating. Concentrations of Mg2+ and protein decreased exponentially with time. There was a high correlation between them, although the Mg2+ was not protein-bound. Sweat urea concentration was directly related to plasma urea concentration. When plasma glucose concentration became greater than 10 to 12 mmole/L during epinephrine infusion, glucose appeared in the sweat and its concentration rose to 8 to 12 mmole/L of sweat when plasma glucose was more than 20 mmole/L.

  10. 3D simulation and analytical model of chemical heating during silicon wet etching in microchannels

    NARCIS (Netherlands)

    Konakov, S.A.; Krzhizhanovskaya, V.V.

    2016-01-01

    We investigate chemical heating of a Silicon-on-Glass (SOG) chip during a highly exothermic reaction of silicon etching in potassium hydroxide (KOH) solution in a microchannel of 100-micron width inside a 1x1 cm SOG chip. Two modeling approaches have been developed, implemented and compared. (1) A

  11. Dry and wet heat transfer through clothing dependent on the clothing properties under cold conditions

    NARCIS (Netherlands)

    Richards, M.G.M.; Rossi, R.; Meinander, H.; Broede, P.; Candas, V.; Hartog, E.A. den; Holmér, I.; Nocker, W.; Havenith, G.

    2008-01-01

    The purpose of this study was to investigate the effect of moisture on the heat transfer through clothing in relation to the water vapour resistance, type of underwear, location of the moisture and climate. This forms part of the work performed for work package 2 of the European Union THERMPROTECT

  12. Hot wet spots of Swiss buildings - detecting clusters of flood exposure

    Science.gov (United States)

    Röthlisberger, Veronika; Zischg, Andreas; Keiler, Margreth

    2016-04-01

    Where are the hotspots of flood exposure in Switzerland? There is no single answer but rather a wide range of findings depending on the databases and methods used. In principle, the analysis of flood exposure is the overlay of two spatial datasets, one on flood hazard and one on assets, e.g. buildings. The presented study aims to test a new developed approach which is based on public available Swiss data. On the hazard side, these are two different types of flood hazard maps each representing a similar return period beyond the dimensioning of structural protection systems. When it comes to assets we use nationwide harmonized data on building, namely a complete dataset of building polygons to which we assign features as volume, residents and monetary value. For the latter we apply findings of multivariate analyses of insurance data. By overlaying building polygons with the flood hazard map we identify the exposed buildings. We analyse the resulting spatial distribution of flood exposure at different levels of scales (local to regional) using administrative units (e.g. municipalities) but also artificial grids with a corresponding size (e.g. 5 000 m). The presentation focuses on the identification of hotspots highlighting the influence of the applied data and methods, e.g. local scan statistics testing intensities within and without potential clusters or log relative exposure surfaces based on kernel intensity estimates. We find a major difference of identified hotspots between absolute values and normalized values of exposure. Whereas the hotspots of flood exposure in absolute figures mirrors the underlying distribution of buildings, the hotspots of flood exposure ratios show very different pictures. We conclude that findings on flood exposure vary depending on the data and moreover the methods used and therefore need to be communicated carefully and appropriate to different stakeholders who may use the information for decision making on flood risk management.

  13. Mapping occupational heat exposure and effects in South-East Asia: ongoing time trends 1980-2011 and future estimates to 2050.

    Science.gov (United States)

    Kjellstrom, Tord; Lemke, Bruno; Otto, Matthias

    2013-01-01

    A feature of climate impacts on occupational health and safety are physiological limits to carrying out physical work at high heat exposure. Heat stress reduces a workers work capacity, leading to lower hourly labour productivity and economic output. We used existing weather station data and climate modeling grid cell data to describe heat conditions (calculated as Wet Bulb Globe Temperature, WBGT) in South-East Asia. During the hottest month in this region (March) afternoon WBGT levels are already high enough to cause major loss of hourly work capacity and by 2050 the situation will be extreme for many outdoor jobs.

  14. A Comprehensive Mathematical Model for Simulation of Latent and Sensible Heat Losses from Wet-Skin Surface and Fur Layer of a Cow

    Directory of Open Access Journals (Sweden)

    Z.A. Khan

    2010-09-01

    Full Text Available This paper presents a comprehensive mathematical model that calculates heat and mass transfer from the skin surface and fur layer of a cow. The model predicts evaporative, respiratory, convective, radiant and urine heat losses for different levels of skin and fur wetness, air velocity, ambient temperature, relative humidity, breathing rate and volume of urine discharged per unit time. Effect of various environmental conditions on skin temperature and consequently heat loss from cow’s body is discussed. It is found that the heat loss through respiration is significant and can not be ignored. Evaporative cooling and respiratory heat losses are, decreased due to increased relative humidity because of increased saturation of ambient air with water particles. It is also found that very small proportion of total body heat is lost through urine in stressful hot environment.

  15. Heat exposure and productivity in orchards: Implications for climate change research.

    Science.gov (United States)

    Quiller, Grant; Krenz, Jennifer; Ebi, Kristie; Hess, Jeremy J; Fenske, Richard A; Sampson, Paul D; Pan, Mengjie; Spector, June T

    2017-11-02

    Recent studies suggest that heat exposure degrades work productivity, but such studies have not considered individual- and workplace-level factors. Forty-six tree-fruit harvesters (98% Latino/a) from 6 orchards participated in a cross-sectional study in central/eastern Washington in 2015. The association between maximum measured work-shift wet-bulb globe temperature (WBGT max ) and productivity (total weight of fruit bins collected per time worked) was estimated using linear mixed-effects models, adjusting for relevant confounders. The mean (standard deviation) WBGT max was 27.9°C (3.6°C) in August and 21.2°C (2.0°C) in September. There was a trend of decreasing productivity with increasing WBGT max , but this association was not statistically significant. When individual- and workplace-level factors were included in the model, the association approached the null. Not considering individual, work, and economic factors that affect rest and recovery in projections of the effects of climate change could result in overestimates of reductions in future productivity and underestimate risk of heat illness.

  16. The development and initial validation of a virtual dripping sweat rate and a clothing wetness ratio for use in predictive heat strain models.

    Science.gov (United States)

    Kubota, H; Kuwabara, K; Hamada, Y

    2014-08-01

    This paper applies the heat balance equation (HBE) for clothed subjects as a linear function of mean skin temperature (t sk ) by a new sweating efficiency (η sw ) and an approximation for the thermoregulatory sweat rate. The equation predicting t sk in steady state conditions was derived as the solution of the HBE and used for a predictive heat strain scale. The heat loss from the wet clothing (WCL) area was identified with a new variable of 'virtual dripping sweat rate VDSR' (S wdr ). This is a subject's un-evaporated sweat rate in dry clothing from the regional sweat rate exceeding the maximum evaporative capacity, and adds the moisture to the clothing, reducing the intrinsic clothing insulation. The S wdr allowed a mass balance analysis of the wet clothing area identified as clothing wetness (w cl ). The w cl was derived by combining the HBE at the WCL surface from which the evaporation rate and skin heat loss from WCL region are given. Experimental results on eight young male subjects wearing typical summer clothing, T-shirt and trousers verified the model for predicting t sk with WCL thermal resistance (R cl,w ) identified as 25 % of dry clothing (R cl,d ).

  17. The development and initial validation of a virtual dripping sweat rate and a clothing wetness ratio for use in predictive heat strain models

    Science.gov (United States)

    Kubota, H.; Kuwabara, K.; Hamada, Y.

    2014-08-01

    This paper applies the heat balance equation (HBE) for clothed subjects as a linear function of mean skin temperature ( t sk ) by a new sweating efficiency ( η sw ) and an approximation for the thermoregulatory sweat rate. The equation predicting t sk in steady state conditions was derived as the solution of the HBE and used for a predictive heat strain scale. The heat loss from the wet clothing (WCL) area was identified with a new variable of `virtual dripping sweat rate VDSR' ( S wdr ). This is a subject's un-evaporated sweat rate in dry clothing from the regional sweat rate exceeding the maximum evaporative capacity, and adds the moisture to the clothing, reducing the intrinsic clothing insulation. The S wdr allowed a mass balance analysis of the wet clothing area identified as clothing wetness ( w cl ). The w cl was derived by combining the HBE at the WCL surface from which the evaporation rate and skin heat loss from WCL region are given. Experimental results on eight young male subjects wearing typical summer clothing, T-shirt and trousers verified the model for predicting t sk with WCL thermal resistance ( R cl,w ) identified as 25 % of dry clothing ( R cl,d ).

  18. Assessment of occupational exposure to heat stress and solar ultraviolet radiation among groundskeepers in an eastern North Carolina university setting.

    Science.gov (United States)

    Beck, Nicole; Balanay, Jo Anne G; Johnson, Terri

    2017-11-01

    Groundskeepers spend most of the year working outdoors, exposing them to heat and solar ultraviolet (UV) radiation and increasing their risk to related adverse health effects. Various studies on heat and UV exposures in different occupations have been published, but those on groundskeepers are rare. The purpose of this study was to assess the exposure to heat stress and solar UV radiation among groundskeepers in an eastern North Carolina university setting. Wet bulb globe temperature (WBGT) index using a heat stress monitor and UV effective irradiance (UVeff) index using a digital UV meter were recorded in various work areas 3 times a day (morning, noon, afternoon) and during 3 seasons (spring, summer, fall). Data analysis was conducted using descriptive statistics, analysis of variance (ANOVA), Tukey Honestly Significant Difference (HSD) and Pearson Correlation tests. The mean (±SD) WBGT index was the highest in the afternoon (25.4±5.0°C), summer (27.8±3.1°C), and July (29.0±2.6°C); the mean UVeff index was the highest at noon, summer and June (0.0116±0.0061, 0.0101±0.0081 and 0.0114±0.0089 mW/cm2, respectively). Differences in the mean WBGT and UVeff indices within the time periods of day, seasons and months were significant (Pheat stress and UV radiation, and are at risk to developing heat- and UV-related illnesses. The study findings will be beneficial in implementing recommended control measures to prevent heat stress and UV exposure among groundskeepers and other similar outdoor workers.

  19. Study of summer heat exposure at the ground services operations of a main international airport in Saudi Arabia.

    Science.gov (United States)

    Noweir, Madbuli H; Bafail, Abdullah O

    2008-10-01

    Summer heat in coastal subtropical Jeddah, augmented by heat from operating ground servicing equipment in King Abdul-Aziz International Airport (KAAIA), presents a major occupational problem to ground service operators, particularly the air traffic control coordinator (ATCC), that hinders their work efficiency and induces health disorders to them. The present study was conducted to assess the magnitude of this problem and propose heat control strategy and remedial actions for the Saudi Arabian Airlines (SAUDIA). Heat parameters including air temperature (T (a)), wet bulb temperature (T (w)), globe temperature (T (g)) and air velocity were measured around serviced planes and in other locations used by ATCC, and the WBGT and the ATCC-WBGT-TWAs were computed. Mostly all the T (a) measurements, and many T (w) measurements, were higher than T (a) and T (w) forecasted by the Presidency of Meteorology and Environment (PME) due to heat dissipated from operating vehicles and equipment in service. The measured and PME forecasted parameters have good and medium linear correlations (T (a): r (2) = 0.74 and T (w): r (2) = 0.64). The computed WBGT in the service stations around planes are considerably higher than the 25 and 27.5 degrees C recommended TLV(R) for non-acclimatized and acclimatized operators. However, the computed ATCC- WBGT-TWA levels indicate that the shift-work-schedule which was recommended to be implemented by SAUDIA has successfully reduced their heat exposure to acceptable levels, except for a very few operators (6.7% exceeding WBGT-TLV(R) of 25 degrees C and 2.2% exceeding TLV(R) of 27.5 degrees C) for whom the shift-work schedules might be corrected to achieve safe heat exposure.

  20. Conceptual designs and cost estimates of mechanical draft wet/dry and natural draft dry cooling systems using Curtiss-Wright integral fin-tube heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Haberski, R.J.; Bentz, J.C.

    1979-04-01

    This study was performed to establish a conceptual design and cost evaluation of an advanced technology mechanical draft wet/dry and natural draft dry cooling systems for large electric power plants using a high performance integral fin-tube heat transfer surface. This study was part of an overall DOE program to develop and demonstrate advanced concept cooling systems for large electric power plants. The results obtained show significant economic advantages compared to results previously published for conventional cooling systems. These advantages are due to the higher heat transfer and lower pressure loss which occur with the use of the selected multi-port integral fin-tubes.

  1. The Heat Strain of Various Athletic Surfaces: A Comparison Between Observed and Modeled Wet-Bulb Globe Temperatures.

    Science.gov (United States)

    Pryor, J Luke; Pryor, Riana R; Grundstein, Andrew; Casa, Douglas J

    2017-11-01

      The National Athletic Trainers' Association recommends using onsite wet-bulb globe temperature (WBGT) measurement to determine whether to modify or cancel physical activity. However, not all practitioners do so and instead they may rely on the National Weather Service (NWS) to monitor weather conditions.   To compare regional NWS WBGT estimates with local athletic-surface readings and compare WBGT measurements among various local athletic surfaces.   Observational study.   Athletic fields.   Measurements from 2 identical WBGT devices were averaged on 10 athletic surfaces within an NWS station reporting radius. Athletic surfaces consisted of red and black all-weather tracks (track), blue and black hard tennis courts (tennis), nylon-knit artificial green turf, green synthetic turfgrass, volleyball sand, softball clay, natural grass (grass), and a natural lake (water). Measurements (n = 143 data pairs) were taken over 18 days (May through September) between 1 pm and 4:30 pm in direct sunlight 1.2 m above ground. The starting location was counterbalanced across surfaces. The NWS weather data were entered into an algorithm to model NWS WBGT.   Black tennis, black track, red track, and volleyball sand WBGT recordings were greater than NWS estimates ( P ≤ .05). When all athletic-surface measurements were combined, NWS (26.85°C ± 2.93°C) underestimated athletic-surface WBGT measurements (27.52°C ± 3.13°C; P < .001). The range of difference scores (-4.42°C to 6.14°C) and the absolute mean difference (1.71°C ± 1.32°C) were large. The difference between the onsite and NWS WBGT measurements resulted in misclassification of the heat-safety activity category 45% (65/143) of the time ([Formula: see text]= 3.857, P = .05). The WBGT of water was 1.4°C to 2.7°C lower than that of all other athletic surfaces ( P = .04). We observed no other differences among athletic surfaces but noted large WBGT measurement variability among athletic playing surfaces.

  2. Consistency between Sweat Rate and Wet Bulb Globe Temperature for the Assessment of Heat Stress of People Working Outdoor in Arid and Semi-arid Regions

    Directory of Open Access Journals (Sweden)

    Hamidreza Heidari

    2018-01-01

    Full Text Available Background: Heat stress is common among workers in arid and semi-arid areas. In order to take every preventive measure to protect exposed workers against heat-related disorders, it is crucial to choose an appropriate index that accurately relates environmental parameters to physiological responses. Objective: To investigate the consistency between 2 heat stress and strain indices, ie, sweat rate and wet bulb globe temperature (WBGT, for the assessment of heat stress of people working outdoor in arid and semi-arid regions in Iran. Methods: During spring and summer, 136 randomly selected outdoor workers were enrolled in this study. Using a defined protocol, the sweat rate of these workers was measured 3 times a day. Simultaneously, the environmental parameters including WBGT index were recorded for each working station. Results: The level of agreement between sweat rate and WBGT was poor (κ<0.2. Based on sweat rate, no case exceeding the reference value was observed during the study. WBGT overestimated the heat stress in outdoor workers compared to sweat rate. Conclusion: It seems that the sweat rate standards may need some modifications related to real condition of work in arid and semi-arid regions in Iran. Moreover, it seems that judging workers solely based on monitoring their sweat rate in such regions, can probably result in underestimation of heat stress.

  3. Heat exposure in sugarcane workers in Costa Rica during the non-harvest season

    Directory of Open Access Journals (Sweden)

    Jennifer Crowe

    2010-11-01

    Full Text Available This observational pilot study was carried out at three sugarcane companies in Costa Rica. Its main objective was to determine the potential for heat stress conditions for workers in one sugarcane-growing region in Costa Rica during the maintenance (non-harvest period.Wet bulb globe temperature (WBGT variables were measured with a heat stress meter and threshold value limits and the Sweat Rate Indexes were calculated for each workplace. It was determined that workers in this study were in heat stress conditions. Costa Rica is likely to experience warmer temperatures and increased heat waves in the coming decades. It is therefore important to take action to decrease current and future heat-related risks for sugarcane workers in both harvest and non-harvest conditions and in all sugarcane growing regions in Costa Rica. It is also necessary to improve guidelines and occupational health standards for protecting worker health and productivity in the tropics.

  4. Effect of Heat Drawing Process on Mechanical Properties of Dry-Jet Wet Spun Fiber of Linear Low Density Polyethylene/Carbon Nanotube Composites

    OpenAIRE

    Kim, Jong Won; Lee, Joon Seok

    2017-01-01

    Polyethylene is one of the most commonly used polymer materials. Even though linear low density polyethylene (LLDPE) has better mechanical properties than other kinds of polyethylene, it is not used as a textile material because of its plastic behavior that is easy to break at the die during melt spinning. In this study, LLDPE fibers were successfully produced with a new approach using a dry-jet wet spinning and a heat drawing process. The fibers were filled with carbon nanotubes (CNTs) to im...

  5. Heat treatment of wet wood fiber: A study of the effect of reaction conditions on the formation of furfurals

    Science.gov (United States)

    Mandla A. Tshabalala; James D. McSweeny; Roger M. Rowell

    2012-01-01

    Furan monomers are produced when wood is heated at high temperatures. To understand the process conditions for production of furfural (FF) and hydroxymethylfurfural (HMF) from wood, samples of milled aspen wood were subjected to autohydrolyzis by microwave heating in a sealed Teflon reactor. The experiments were designed to simulate temperature and pressure variables...

  6. The effect of herbal extract Foeniculum vulgare Mill. solution on the mechanical and wetting properties of heat polymerized denture base resin

    Directory of Open Access Journals (Sweden)

    Petrović Milica B.

    2016-01-01

    Full Text Available Introduction. Commercially used chemical dental cleansers adversely affect mechanical properties of denture. Therefore, there is a need for finding an alternative which will not change the surface properties of material. Aim. This paper studied the effect of the herbal extract (Foeniculum vulgare Mill. solution on the wetting and mechanical properties of heat-polymerized denture base resin compared to the same properties of the same resin in the native state (in air and exposed only to aqueous environment. Material and methods. Rectangular shape of heat polymerized acrylic resin (15 mm x 15 mm x 3 mm were prepared and divided into: (i sample continuously exposed to air - AIR; (ii sample continuously exposed to distilled water - DW; and (iii sample exposed to 10% solution of the fennel leaves extract - PES. Wetting properties were measured by sessile drop method, whereas mechanical properties were analyzed by nanoindentation method. Results. Results showed that samples AIR had the lowest ΘC value 64.5±2.3 °, while the other two samples DW and PES had similar ΘC values (75.4±3.3 °, 75.7±4.7 °, respectively. Furthermore, there was no statistically significant difference in hardness coefficient, while Young's modulus showed a significant difference (p < 0.005 only between the samples AIR and DW. Conclusion. The obtained values confirmed that fennel extract can be used as successful and efficient cleanser, without degradation of denture surface.

  7. Evaluation of the workers exposure to heat and presenting intervention to control heat stress in profile factory

    Directory of Open Access Journals (Sweden)

    Motamedzade Majid

    2014-10-01

    Full Text Available Background & Objectives : Exposure to heat is a significant problem in the Industries. The present study aimed at the evaluation of thermal risk, measurement of heat stress index, and proposing a plan for heat control in cutting and welding units in profile factory . Methods : The data of study was analyzed through the measurement of physical parameters with digital WBGT device and silvered Kata thermometer. Workers’ thermal comfort was calculated based on predicted mean voted (PMV and predicted percentage of dissatisfied (PPD with regard to the computed parameters. In order to control heat stress, an aluminum-insulated wall was used and airflow velocity was increased in cutting and welding units. Results : The results of the WBGT index before and after the intervention using the shield were 30.8° C and 23.2° C, and by increasing airflow velocity were 30° C and 29.5° C respectively. In addition, the obtained results for PMV and PPD by using the shield were 1.38 and %44, and by increasing airflow velocity they were %90 and 2.56 respectively. The results confirmed by using the shield the measured WBGT index was lower than the occupational exposure limit (28 ◦ c. Conclusion : The results showed that by appropriate designing and using control methods, such as insulation shield and increased airflow velocity, optimal thermal comfort based on national heat exposure limits could be reached .

  8. Inflammatory cytokines and plasma redox status responses in hypertensive subjects after heat exposure

    Directory of Open Access Journals (Sweden)

    S.F. Fonseca

    2016-03-01

    Full Text Available Hypertension is characterized by a pro-inflammatory status, including redox imbalance and increased levels of pro-inflammatory cytokines, which may be exacerbated after heat exposure. However, the effects of heat exposure, specifically in individuals with inflammatory chronic diseases such as hypertension, are complex and not well understood. This study compared the effects of heat exposure on plasma cytokine levels and redox status parameters in 8 hypertensive (H and 8 normotensive (N subjects (age: 46.5±1.3 and 45.6±1.4 years old, body mass index: 25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure: 98.0±2.8 and 86.0±2.3 mmHg, respectively. They remained at rest in a sitting position for 10 min in a thermoneutral environment (22°C followed by 30 min in a heated environmental chamber (38°C and 60% relative humidity. Blood samples were collected before and after heat exposure. Plasma cytokine levels were measured using sandwich ELISA kits. Plasma redox status was determined by thiobarbituric acid reactive substances (TBARS levels and ferric reducing ability of plasma (FRAP. Hypertensive subjects showed higher plasma levels of IL-10 at baseline (P<0.05, although levels of this cytokine were similar between groups after heat exposure. Moreover, after heat exposure, hypertensive individuals showed higher plasma levels of soluble TNF receptor (sTNFR1 and lower TBARS (P<0.01 and FRAP (P<0.05 levels. Controlled hypertensive subjects, who use angiotensin-converting-enzyme inhibitor (ACE inhibitors, present an anti-inflammatory status and balanced redox status. Nevertheless, exposure to a heat stress condition seems to cause an imbalance in the redox status and an unregulated inflammatory response.

  9. The influence of a season of extreme wet weather events on exposure of the World Heritage Area Great Barrier Reef to pesticides.

    Science.gov (United States)

    Kennedy, Karen; Devlin, Michelle; Bentley, Christie; Lee-Chue, Kristie; Paxman, Chris; Carter, Steve; Lewis, Stephen E; Brodie, Jon; Guy, Ellia; Vardy, Suzanne; Martin, Katherine C; Jones, Alison; Packett, Robert; Mueller, Jochen F

    2012-07-01

    The 2010-2011 wet season was one of extreme weather for the State of Queensland, Australia. Major rivers adjacent to the Great Barrier Reef (GBR) were discharging at rates 1.5 to >3 times higher than their long term median. Exposure to photosystem II herbicides has been routinely monitored over a period of up to 5 years at 12 inshore GBR sites. The influence of this wet season on exposure to photosystem II herbicides was examined in the context of this long-term monitoring record and during flood plume events in specific regions. Median exposures expressed as diuron equivalent concentration were an average factor of 2.3 times higher but mostly not significantly different (p<0.05) to the median for the long-term monitoring record. The herbicides metolachlor and tebuthiuron were frequently detected in flood plume waters at concentrations that reached or exceeded relevant water quality guidelines (by up to 4.5 times). Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Stress Responses to Heat Exposure in Three Species of Australian Desert Birds.

    Science.gov (United States)

    Xie, Shangzhe; Romero, L Michael; Htut, Zaw Win; McWhorter, Todd J

    Birds need to respond to weather changes quickly and appropriately for their own well-being and survival. The inability to respond appropriately to heat waves can be fatal to individual birds and can translate into large-scale mortality events. We investigated corticosterone (CORT) and heterophil∶lymphocyte (H∶L) ratio responses of budgerigars (Melopsittacus undulatus), zebra finches (Taeniopygia guttata), and diamond doves (Geopelia cuneata) to heat exposures. The birds were exposed to a temperature similar to what they experience during a typical summer day (35°C) and a higher temperature (45°C) similar to that experienced during a heat wave. There were no significant increases between the CORT concentrations before and after heat exposure in zebra finches and budgerigars at 35° and 45°C, but there was a significant increase in CORT concentrations in diamond doves after exposure to 45°C. The H∶L ratios increased significantly after heat exposure in budgerigars at 35° and 45°C and in diamond doves at 35°C. No significant correlation was found between the changes in CORT and H∶L ratios. The data suggest that there are species differences in birds' stress responses to heat exposure that may reflect their ability to detect and adapt to high temperatures. There appear to be differences between the two types of stress measurements, which may reflect differences in the timescales of these responses.

  11. The effects of wet cupping on serum high-sensitivity C-reactive protein and heat shock protein 27 antibody titers in patients with metabolic syndrome.

    Science.gov (United States)

    Farahmand, Seyed Kazem; Gang, Li Zhi; Saghebi, Seyed Ahmad; Mohammadi, Maryam; Mohammadi, Shabnam; Mohammadi, Ghazaleh; Ferns, Gordan A; Ghanbarzadeh, Majid; Razmgah, Gholamreza Ghayour; Ramazani, Zahra; Ghayour-Mobarhan, Majid; Esmaily, Habibollah; Bahrami Taghanaki, Hamidreza; Azizi, Hoda

    2014-08-01

    It has previously been reported that increased level of serum heat shock proteins (Hsps) antibody in patients with metabolic syndrome. It is possible that the expression of Hsp and inflammatory markers can be affected by cupping and traditional Chinese medicine. There is a little data investigating the effects of cupping on markers of inflammation and Hsp proteins, hence, the objective of this study was evaluation of the effects of wet cupping on serum high-sensitivity C-reactive protein (hs-CRP) and Hsp27 antibody titers in patients with metabolic syndrome. Serum Hs-CRP and Hsp27 antibody titers were assessed in samples from 126 patients with metabolic syndrome (18-65 years of age) at baseline, and after 6 and 12 weeks after treatment. One hundred and twenty-six patients were randomly divided into the experimental group treated with wet cupping combined with dietary advice, and the control group treated with dietary advice alone using a random number table. Eight patients in case group and five subjects in control groups were excluded from the study. Data were analyzed using SPSS 15.0 software and a repeated measure ANCOVA. Serum hs-CRP titers did not change significantly between groups (p>0.05) and times (p=0.27). The same result was found for Hsp27 titers (p>0.05). Wet-cupping on the interscapular region has no effect on serum hs-CRP and Hsp27 patients with metabolic syndrome. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Effect of Heat Drawing Process on Mechanical Properties of Dry-Jet Wet Spun Fiber of Linear Low Density Polyethylene/Carbon Nanotube Composites

    Directory of Open Access Journals (Sweden)

    Jong Won Kim

    2017-01-01

    Full Text Available Polyethylene is one of the most commonly used polymer materials. Even though linear low density polyethylene (LLDPE has better mechanical properties than other kinds of polyethylene, it is not used as a textile material because of its plastic behavior that is easy to break at the die during melt spinning. In this study, LLDPE fibers were successfully produced with a new approach using a dry-jet wet spinning and a heat drawing process. The fibers were filled with carbon nanotubes (CNTs to improve the strength and reduce plastic deformation. The crystallinity, degree of orientation, mechanical properties (strength to yield, strength to break, elongation at break, and initial modulus, electrical conductivity, and thermal properties of LLDPE fibers were studied. The results show that the addition of CNTs improved the tensile strength and the degree of crystallinity. The heat drawing process resulted in a significant increase in the tensile strength and the orientation of the CNTs and polymer chains. In addition, this study demonstrates that the heat drawing process effectively decreases the plastic deformation of LLDPE.

  13. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures

    OpenAIRE

    Behnaz Ghaedi; Nigel R. Andrew

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour...

  14. Modeling and experimental validation in partially wet conditions of an air-to-air heat recovery exchanger

    OpenAIRE

    Gendebien, Samuel; Bertagnolio, Stéphane; Lemort, Vincent

    2011-01-01

    Nowadays, important efforts are deployed to reduce our current residential building consumption. The most common retrofit option concerns the air tightness and the thermal insulation improvement. However, this latter retrofit option could decrease the air indoor quality because of a reduction of air infiltration flow rate. Installation of an air-to-air heat recovery system allows for an efficient combination between consumption reduction due to the air tightness improvement and acceptable air...

  15. Landscapes of thermal inequity: disproportionate exposure to urban heat in the three largest US cities

    Science.gov (United States)

    Mitchell, Bruce C.; Chakraborty, Jayajit

    2015-11-01

    Heat waves are the most significant cause of mortality in the US compared to other natural hazards. Prior studies have found increased heat exposure for individuals of lower socioeconomic status in several US cities, but few comparative analyses of the social distribution of urban heat have been conducted. To address this gap, our paper examines and compares the environmental justice consequences of urban heat risk in the three largest US cities: New York City, Los Angeles, and Chicago. Risk to urban heat is estimated on the basis of three characteristics of the urban thermal landscape: land surface temperature, vegetation abundance, and structural density of the built urban environment. These variables are combined to develop an urban heat risk index, which is then statistically compared with social vulnerability indicators representing socioeconomic status, age, disability, race/ethnicity, and linguistic isolation. The results indicate a consistent and significant statistical association between lower socioeconomic and minority status and greater urban heat risk, in all three cities. Our findings support a growing body of environmental justice literature that indicates the presence of a landscape of thermal inequity in US cities and underscores the need to conduct comparative analyses of social inequities in exposure to urban heat.

  16. Modelling Dietary Exposure to Chemical Components in Heat-Processed Meats

    DEFF Research Database (Denmark)

    Georgiadis, Stylianos; Jakobsen, Lea Sletting; Nielsen, Bo Friis

    Several chemical compounds that potentially increase the risk of developing cancer in humans are formed during heat processing of meat. Estimating the overall health impact of these compounds in the population requires accurate estimation of the exposure to the chemicals, as well as the probability.......g. the Poisson-Lognormal approach, are promising tools to address this obstacle. The exposure estimates can then be applied to dose-response models to quantify the cancer risk....

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

    Science.gov (United States)

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

    2014-08-01

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

  18. Experimental study on moisture transfer through firefighters' protective fabrics in radiant heat exposures

    Directory of Open Access Journals (Sweden)

    Chen Meng

    2017-01-01

    Full Text Available The effects of absorbed moisture on thermal protective performance of fire-fighters’ clothing materials under radiant heat flux conditions were analyzed in this paper. A thermal protective performance tester and temperature sensor were used to measure the temperature variations for the facecloth side of four kinds of commonly used flame retardant fabrics in several radiant heat exposures, which varied in moisture content. Experimental results showed that, all of the temperature profiles of these four kinds of moistened fabrics under different radiant heat flux conditions presented the same variation trend. The addition of moisture had a positive influence on the thermal protective performance during the constant temperature period when heat radiation time was more than 60 seconds. As the heat radiation time increased beyond 500 seconds, the thermal protective performance of moistened fabrics became worse than that of dried fabrics in general.

  19. Wet gas sampling

    Energy Technology Data Exchange (ETDEWEB)

    Welker, T.F.

    1997-07-01

    The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

  20. Nutritional and physiological responses of finishing pigs exposed to a permanent heat exposure during three weeks.

    Science.gov (United States)

    Hao, Yue; Feng, Yuejin; Yang, Peige; Feng, Jinghai; Lin, Hai; Gu, Xianhong

    2014-01-01

    The aim of the current study was to investigate the effect of a permanent heat exposure during 21 days on pig performance, nutrient digestibility, physiological response and key enzyme of skeletal muscle energy metabolism. Twenty-four male finishing pigs (crossbreed castrates, 79.0 ± 1.50 kg body weight) were allocated to three groups (n = 8): (1) Control (ambient temperature (AT) 22°C, ad libitum feeding), (2) Group HE (AT 30°C, ad libitum feeding) and (3) Group PF (AT 22°C, pair-fed to Group HE). The permanent heat exposure decreased feed intake (p weight gain (p cortisol, creatine kinase and lactate dehydrogenase were also significantly increased in Group HE (p < 0.05). Furthermore, the heat exposure changed intracellular energy metabolism, where the AMP-activated protein kinase was activated (p = 0.02). This was combined with changes in parameters of glycolysis such as an accumulation of lactic acid (p = 0.02) and a drop of pH24 h (p = 0.02), an increase of hexokinase and pyruvate kinase activity (p < 0.01) and, finally, the maturation process of post mortem muscle was influenced. Due to pair-feeding it was possible to evaluate the effects of heat exposure, which were not dependent on reduced feed intake. Such effects were, e.g., reduced nutrient digestibility and changed activities of several enzymes in muscle and blood serum.

  1. The effect of acute heat exposure on rat pituitary corticotroph activation: the role of vasopressin.

    Directory of Open Access Journals (Sweden)

    Sinisa Djurasevic

    2011-04-01

    Full Text Available The increased ambient temperature affects the function of hypothalamic-pituitary-adrenal (HPA axis. Since the correlation among vasopressin (VP, adrenocorticotropic hormone (ACTH and corticosterone (CORT responses to various stressors have been long recognized, the aim of this study was to reveal the aforementioned hormones production and morphology of the pituitary gland after exposure to acute heat. Rats were exposed to high ambient temperature (38 °C for 20 or 60 minutes. The circulating hormones were determined by an ELISA test or chemiluminescence's method. The results obtained show the elevation in ACTH and CORT secretion depending on the duration of heat exposure. The VP concentration increased only after prolonged exposure to heat (60 min. The pituitary morphology was examined by routine and fluorescent immunohistochemistry as well as electron microscopy. Observed changes in the anterior and posterior pituitary well corresponded to circulating hormones, regarding the volume density of ACTH-immunopositive cells, percentage of ACTH immunopositive area v. total area and number of VP-immunopositive containing varicose fibers per total area. Acute heat exposure also induced changes in shapes of ACTH-immunopositive cells. Cells appeared stellate with numerous slender cytoplasmic processes and degranulated, which is the most obvious after 20 min. In addition, immunopositivity of endothelial and anterior pituitary cells for VP suggests its influence on ACTH secretion.

  2. High resolution exposure modelling of heat and air pollution and the impact on mortality

    NARCIS (Netherlands)

    Willers, S.M.; Jonker, M.F.; Klok, L.; Keuken, M.P.; Odink, J.; Elshout, S. van den; Sabel, C.E.; Mackenbach, J.P.; Burdorf, A.

    2016-01-01

    Background: Elevated temperature and air pollution have been associated with increased mortality. Exposure to heat and air pollution, as well as the density of vulnerable groups varies within cities. The objective was to investigate the extent of neighbourhood differences in mortality risk due to

  3. Is ambient heat exposure levels associated with miscarriage or stillbirths in hot regions? A cross-sectional study using survey data from the Ghana Maternal Health Survey 2007

    Science.gov (United States)

    Asamoah, Benedict; Kjellstrom, Tord; Östergren, Per-Olof

    2017-07-01

    It is well established that high ambient heat could cause congenital abnormalities resulting in miscarriage or stillbirth among certain species of mammals. However, this has not been systematically studied in real field settings among humans, despite the potential value of such knowledge for estimating the impact of global warming on the human species. This study sought to test the hypothesis that maternal heat exposure during pregnancy in hot regions is associated with increased prevalence of spontaneous abortions or stillbirths and to develop an analytical strategy to use existing data from maternal health surveys and existing data on historical heat levels at a geographic grid cell level. A subsample of the Ghana Maternal Health Survey 2007 was used in this study. This study sample consisted of 1136 women with pregnancy experiences between 2004 and 2007, out of which 141 women had a pregnancy that terminated in miscarriage or stillbirth. Induced-abortion cases were excluded. The linkage between ambient heat exposure and pregnancy outcome followed the epidemiological time-place-person principle, by linking timing of pregnancy outcome with historical data of local area heat levels for each month, as estimated in an international database. Maternal heat exposure level was estimated using calculated levels of the wet-bulb globe temperature (WBGT), which takes into account temperature, humidity, heat radiation, and air movement over the skin (wind speed). The values we used applied to exposure in the shade or in buildings without cooling (no solar heat radiation) and a standard air movement of 1 m/s. We applied two exposure durations: yearly average and monthly average for second month of pregnancy. In one analysis, we restricted the sample to four regions with time-homogeneous ambient heat. Analysis was made using logistic regression. About 12% of the latest pregnancies ended in either miscarriage (9.6%) or stillbirth (2.8%). The odds ratios indicated 12 to 15

  4. Brain Surface Heating After Exposure to Ultrasound: An Analysis Using Thermography.

    Science.gov (United States)

    Schneider, Michal E; Lombardo, Paul

    2016-05-01

    Ultrasound is the imaging modality of choice to monitor brain pathologies in neonates after complicated deliveries. Animal studies have indicated that ultrasound may cause heating of brain tissues. To date, no study has explored brain surface heating by ultrasound during clinically relevant exposure. Hence, we investigated heating effects of B-mode and pulsed Doppler (PD) mode on ex vivo lamb brains using thermography. Five brains were scanned for 5 min in B-mode or for 3 min, 1 min, 30 s or 15 s in PD mode. Brain surface temperature was measured pre- and post-exposure using thermography. The highest mean temperature increase was recorded by B-mode (3.82 ± 0.43°C). All five PD exposure protocols were associated with surface temperature increases of 2.1-2.7°C. These outcomes highlight for the first time that B-mode ultrasound can contribute to brain surface heating during a routine cranial scan. Scan duration should be minimised whenever possible. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. The Be-WetSpa-Pest modeling approach to simulate human and environmental exposure from pesticide application

    Science.gov (United States)

    Binder, Claudia; Garcia-Santos, Glenda; Andreoli, Romano; Diaz, Jaime; Feola, Giuseppe; Wittensoeldner, Moritz; Yang, Jing

    2016-04-01

    This study presents an integrative and spatially explicit modeling approach for analyzing human and environmental exposure from pesticide application of smallholders in the potato producing Andean region in Colombia. The modeling approach fulfills the following criteria: (i) it includes environmental and human compartments; (ii) it contains a behavioral decision-making model for estimating the effect of policies on pesticide flows to humans and the environment; (iii) it is spatially explicit; and (iv) it is modular and easily expandable to include additional modules, crops or technologies. The model was calibrated and validated for the Vereda La Hoya and was used to explore the effect of different policy measures in the region. The model has moderate data requirements and can be adapted relatively easy to other regions in developing countries with similar conditions.

  6. Change in algal symbiont communities after bleaching, not prior heat exposure, increases heat tolerance of reef corals.

    Science.gov (United States)

    Silverstein, Rachel N; Cunning, Ross; Baker, Andrew C

    2015-01-01

    Mutualistic organisms can be particularly susceptible to climate change stress, as their survivorship is often limited by the most vulnerable partner. However, symbiotic plasticity can also help organisms in changing environments by expanding their realized niche space. Coral-algal (Symbiodinium spp.) symbiosis exemplifies this dichotomy: the partnership is highly susceptible to 'bleaching' (stress-induced symbiosis breakdown), but stress-tolerant symbionts can also sometimes mitigate bleaching. Here, we investigate the role of diverse and mutable symbiotic partnerships in increasing corals' ability to thrive in high temperature conditions. We conducted repeat bleaching and recovery experiments on the coral Montastraea cavernosa, and used quantitative PCR and chlorophyll fluorometry to assess the structure and function of Symbiodinium communities within coral hosts. During an initial heat exposure (32 °C for 10 days), corals hosting only stress-sensitive symbionts (Symbiodinium C3) bleached, but recovered (at either 24 °C or 29 °C) with predominantly (>90%) stress-tolerant symbionts (Symbiodinium D1a), which were not detected before bleaching (either due to absence or extreme low abundance). When a second heat stress (also 32 °C for 10 days) was applied 3 months later, corals that previously bleached and were now dominated by D1a Symbiodinium experienced less photodamage and symbiont loss compared to control corals that had not been previously bleached, and were therefore still dominated by Symbiodinium C3. Additional corals that were initially bleached without heat by a herbicide (DCMU, at 24 °C) also recovered predominantly with D1a symbionts, and similarly lost fewer symbionts during subsequent thermal stress. Increased thermotolerance was also not observed in C3-dominated corals that were acclimated for 3 months to warmer temperatures (29 °C) before heat stress. These findings indicate that increased thermotolerance post-bleaching resulted from

  7. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures

    Science.gov (United States)

    Andrew, Nigel R.

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride) and benefits (based on production of more osmolytes) in repeated high temperature treatments. As aphids are known to respond differently to constant versus ‘natural’ fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies. PMID:27547583

  8. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures

    Directory of Open Access Journals (Sweden)

    Behnaz Ghaedi

    2016-08-01

    Full Text Available The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride and benefits (based on production of more osmolytes in repeated high temperature treatments. As aphids are known to respond differently to constant versus ‘natural’ fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies.

  9. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures.

    Science.gov (United States)

    Ghaedi, Behnaz; Andrew, Nigel R

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride) and benefits (based on production of more osmolytes) in repeated high temperature treatments. As aphids are known to respond differently to constant versus 'natural' fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies.

  10. Effects of occupational heat exposure on female brick workers in West Bengal, India

    Directory of Open Access Journals (Sweden)

    Moumita Sett

    2014-02-01

    : We conclude that high heat exposure in brickfields during summer caused physiological strain in both categories of female brickfield workers. A coping strategy employed by the brick carriers was to reduce their walking speed and thus lose part of their earnings. The lost productivity for every degree rise in temperature is about 2% in the brickfields. This reduction will be exacerbated by climate change and may undermine the quality of life of female brickfield workers.

  11. A Heat Vulnerability Index: Spatial Patterns of Exposure, Sensitivity and Adaptive Capacity for Santiago de Chile

    Science.gov (United States)

    Palme, Massimo; de la Barrera, Francisco

    2016-01-01

    Climate change will worsen the high levels of urban vulnerability in Latin American cities due to specific environmental stressors. Some impacts of climate change, such as high temperatures in urban environments, have not yet been addressed through adaptation strategies, which are based on poorly supported data. These impacts remain outside the scope of urban planning. New spatially explicit approaches that identify highly vulnerable urban areas and include specific adaptation requirements are needed in current urban planning practices to cope with heat hazards. In this paper, a heat vulnerability index is proposed for Santiago, Chile. The index was created using a GIS-based spatial information system and was constructed from spatially explicit indexes for exposure, sensitivity and adaptive capacity levels derived from remote sensing data and socio-economic information assessed via principal component analysis (PCA). The objective of this study is to determine the levels of heat vulnerability at local scales by providing insights into these indexes at the intra city scale. The results reveal a spatial pattern of heat vulnerability with strong variations among individual spatial indexes. While exposure and adaptive capacities depict a clear spatial pattern, sensitivity follows a complex spatial distribution. These conditions change when examining PCA results, showing that sensitivity is more robust than exposure and adaptive capacity. These indexes can be used both for urban planning purposes and for proposing specific policies and measures that can help minimize heat hazards in highly dynamic urban areas. The proposed methodology can be applied to other Latin American cities to support policy making. PMID:27606592

  12. High resolution exposure modelling of heat and air pollution and the impact on mortality.

    Science.gov (United States)

    Willers, Saskia M; Jonker, Marcel F; Klok, Lisette; Keuken, Menno P; Odink, Jennie; van den Elshout, Sef; Sabel, Clive E; Mackenbach, Johan P; Burdorf, Alex

    2016-01-01

    Elevated temperature and air pollution have been associated with increased mortality. Exposure to heat and air pollution, as well as the density of vulnerable groups varies within cities. The objective was to investigate the extent of neighbourhood differences in mortality risk due to heat and air pollution in a city with a temperate maritime climate. A case-crossover design was used to study associations between heat, air pollution and mortality. Different thermal indicators and air pollutants (PM10, NO2, O3) were reconstructed at high spatial resolution to improve exposure classification. Daily exposures were linked to individual mortality cases over a 15year period. Significant interaction between maximum air temperature (Tamax) and PM10 was observed. During "summer smog" days (Tamax>25°C and PM10>50μg/m(3)), the mortality risk at lag 2 was 7% higher compared to the reference (Tamax 15°C and PM10 15μg/m(3)). Persons above age 85 living alone were at highest risk. We found significant synergistic effects of high temperatures and air pollution on mortality. Single living elderly were the most vulnerable group. Due to spatial differences in temperature and air pollution, mortality risks varied substantially between neighbourhoods, with a difference up to 7%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Exposure of CFC-materials to high transient heat loads in the TEXTOR tokamak

    Science.gov (United States)

    Scholz, T.; Boedo, J.; Bolt, H.; Duwe, R.; Finken, K. H.; Gray, D.; Hassanein, A.

    1997-02-01

    Transient high heat flux events like ELMs, vertical displacement events and disruptions can cause the thermal ablation of plasma facing material. Until now experimental work in this field had been carried out by exposing material specimens to heat loads by electron or laser beam or by tests in pulsed plasma accelerators. In the present work carbon specimens were directly exposed to intense plasma fluxes in the TEXTOR tokamak. The exposure was performed with a fast probe allowing the insertion of the material over a distance of 9 cm into the edge plasma for a duration of 80 ms. The results of in-situ diagnostic measurements and of the post-experiment examination of the specimens are compared with a reference experiment by electron beam and with numerical analyses. Results indicated that the heat flux to the probe surfaces and the probe erosion is much lower than expected.

  14. Exploring the molecular mechanism of acute heat stress exposure in broiler chickens using gene expression profiling.

    Science.gov (United States)

    Luo, Q B; Song, X Y; Ji, C L; Zhang, X Q; Zhang, D X

    2014-08-10

    The process of heat regulation is complex and its exact molecular mechanism is not fully understood. In this study, to investigate the global gene regulation response to acute heat exposure, gene microarrays were exploited to analyze the effects of heat stress on three tissues (brain, liver, leg muscle) of the yellow broiler chicken (Gallus gallus). We detected 166 differentially expressed genes (DEGs) in the brain, 219 in the leg muscle and 317 in the liver. Six of these genes were differentially expressed in all three tissues and were validated by qRT-PCR, and included heat shock protein genes (HSPH1, HSP25), apoptosis-related genes (RB1CC1, BAG3), a cell proliferation and differentiation-related gene (ID1) and the hunger and energy metabolism related gene (PDK). All these genes might be important factors in chickens suffering from heat stress. We constructed gene co-expression networks using the DEGs of the brain, leg muscle and liver and two, four and two gene co-expression modules were identified in these tissues, respectively. Functional enrichment of these gene modules revealed that various functional clusters were related to the effects of heat stress, including those for cytoskeleton, extracellular space, ion binding and energy metabolism. We concluded that these genes and functional clusters might be important factors in chickens under acute heat stress. Further in-depth research on the newly discovered heat-related genes and functional clusters is required to fully understand their molecular functions in thermoregulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Inactivation of Salmonella enterica in chicken feces on the surface of eggshells by simultaneous treatments with gaseous chlorine dioxide and mild wet heat.

    Science.gov (United States)

    Park, Sunhyung; Beuchat, Larry R; Kim, Hoikyung; Ryu, Jee-Hoon

    2017-04-01

    The aim of this study was to investigate the lethal effects of simultaneous treatments with gaseous chlorine dioxide (ClO2) and mild wet heat (55 °C at 100% relative humidity [RH]) on Salmonella enterica in chicken feces on the surface of eggshells. Gaseous ClO2 production decreased significantly (P ≤ 0.05) as the RH (23, 43, 68, 85, and 100%) at 25 °C was increased. The lethality of gaseous ClO2 against S. enterica in feces on eggshells increased significantly (P ≤ 0.05) as RH increased. For example, when treated with gaseous ClO2 at 85 and 100% RH at 25 °C, S. enterica (5.9 log CFU/egg) was inactivated within 4 h. In contrast, at 23, 43, and 68% RH, the pathogen remained at 5.1, 5.0, and 2.8 log CFU/egg, respectively, after 6 h. Finally, when eggshells surface-contaminated with S. enterica (5.8 log CFU/egg) were treated with gaseous ClO2 (peak concentration of ClO2: 185.6 ppm) at 100% RH and 55 °C, inactivation occurred within 1 h. These results indicate that treatment of surface-contaminated shell eggs with gaseous ClO2 at elevated RH and temperature is effective in inactivating S. enterica. These observations will be useful when developing an effective sanitation program to enhance the microbiological safety of shell eggs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Influence of wet heating and autoclaving on chemical composition and standardized ileal crude protein and amino acid digestibility in full-fat soybeans for pigs.

    Science.gov (United States)

    Kaewtapee, C; Eklund, M; Wiltafsky, M; Piepho, H-P; Mosenthin, R; Rosenfelder, P

    2017-02-01

    One batch each of eight full-fat soybeans (FFSB) was used to determine the effect of different heat treatments including wet heating (WH) and autoclaving (AC) on chemical composition and standardized ileal digestibility (SID) of CP and AA in growing pigs. The raw FFSB (K0) were either treated by WH at 80°C for 1 min (K1), at 100°C for 6 min (K2), or at 100°C for 16 min (K3). Thereafter, these batches were expanded at 125°C for 15 s. A further heat treatment included AC at 110°C for 15 (Z1), 30 (Z2), 45 (Z3), or 60 (Z4) min of FFSB that were subjected to the same WH treatment as K3. Diets were formulated to contain the respective FFSB as the sole source of CP and AA. A N-free diet was used to measure basal endogenous losses of CP and AA in an additional period at the end of the experiment. Eight ileally cannulated pigs (28 ± 1 kg) were allocated to a row-column design with 8 diets and 6 periods of 7 d each. An increase in the duration of WH had no effect on contents of AA (% of CP) and NDF, but NDIN contents linearly increased ( < 0.05) with increasing time for WH. Autoclaving resulted in a linear decrease ( < 0.05) of trypsin inhibitor activity (TIA), contents of Arg, Leu, Ala, Asp, Cys, and Gly as well as Lys to CP ratio (Lys:CP), reactive Lys to CP ratio (rLys:CP), and in an increase ( < 0.05) in contents of NDF and NDIN. There was a quadratic response ( < 0.05) of SID of CP and AA as time for WH at 100°C increased from 0 (K0) to 6 (K2) up to 16 (K3) min. Moreover, a quadratic response ( < 0.05) to increasing time of AC was observed for SID of Arg, Phe, and Pro. The SID of CP and all indispensable AA showed a quadratic response ( < 0.05) to decreasing TIA, urease activity, protein solubility in 0.2% potassium hydroxide, protein dispersibility index, Lys:CP, (lightness), and to increasing NDIN and (redness). In addition, there was a linear increase ( < 0.05) in SID values with decreasing rLys:CP and increasing NDF contents. In conclusion, WH proved to be

  17. Deep Heat Mining - Development of the hot dry rock and hot wet rock technologies for power and heat production in Switzerland; Deep Heat Mining. Entwicklung der Hot-Dry-Rock / Hot-Wet-Rock Technologie zur Strom- und Waermeproduktion in der Schweiz, insbesondere Deep Heat Mining, Basel

    Energy Technology Data Exchange (ETDEWEB)

    Haering, M. O.; Hopkirk, R. J.

    2003-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the progress and achievements made for two heat mining projects in Basle and Geneva. Work initialised at further sites in southern Switzerland and in the Bernese 'Oberland' alpine area is also mentioned. Project organisation and planning topics are examined. Seismic monitoring aspects are discussed and first practical studies on using the geothermal heat in Basle using hybrid energy conversion systems are discussed. For the Geneva project, details on site selection are given and ideas on combined geothermal and gas turbine plant are discussed.

  18. Heat Exposure and Maternal Health in the Face of Climate Change

    Science.gov (United States)

    Kuehn, Leeann; McCormick, Sabrina

    2017-01-01

    Climate change will increasingly affect the health of vulnerable populations, including maternal and fetal health. This systematic review aims to identify recent literature that investigates increasing heat and extreme temperatures on pregnancy outcomes globally. We identify common research findings in order to create a comprehensive understanding of how immediate effects will be sustained in the next generation. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guide, we systematically reviewed articles from PubMed and Cochrane Reviews. We included articles that identify climate change-related exposures and adverse health effects for pregnant women. There is evidence that temperature extremes adversely impact birth outcomes, including, but not limited to: changes in length of gestation, birth weight, stillbirth, and neonatal stress in unusually hot temperature exposures. The studies included in this review indicate that not only is there a need for further research on the ways that climate change, and heat in particular, may affect maternal health and neonatal outcomes, but that uniform standards for assessing the effects of heat on maternal fetal health also need to be established. PMID:28758917

  19. Heat Exposure and Maternal Health in the Face of Climate Change

    Directory of Open Access Journals (Sweden)

    Leeann Kuehn

    2017-07-01

    Full Text Available Climate change will increasingly affect the health of vulnerable populations, including maternal and fetal health. This systematic review aims to identify recent literature that investigates increasing heat and extreme temperatures on pregnancy outcomes globally. We identify common research findings in order to create a comprehensive understanding of how immediate effects will be sustained in the next generation. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA guide, we systematically reviewed articles from PubMed and Cochrane Reviews. We included articles that identify climate change-related exposures and adverse health effects for pregnant women. There is evidence that temperature extremes adversely impact birth outcomes, including, but not limited to: changes in length of gestation, birth weight, stillbirth, and neonatal stress in unusually hot temperature exposures. The studies included in this review indicate that not only is there a need for further research on the ways that climate change, and heat in particular, may affect maternal health and neonatal outcomes, but that uniform standards for assessing the effects of heat on maternal fetal health also need to be established.

  20. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of

  1. Vaginitis test - wet mount

    Science.gov (United States)

    Wet prep - vaginitis; Vaginosis - wet mount; Trichomoniasis - wet mount; Vaginal candida - wet mount ... a rash, painful intercourse, or odor after intercourse. Trichomoniasis , a sexually transmitted disease. Vaginal yeast infection .

  2. EFFECT OF EXPOSURE PROTOCOL AND HEAT SHOCK PROTEIN EXPRESSION ON ARSENITE INDUCED GENOTOXICITY IN MCF-7 BREAST CANCER CELLS

    Science.gov (United States)

    Effect of exposure protocol and heat shock protein expression on arsenite induced genotoxicity in MCF-7 breast cancer cells The genotoxic effects of arsenic (As) are well accepted, yet its mechanism of action is not clearly defined. Heat-shock proteins (HSPs) protect...

  3. Global and regional changes in exposure to extreme heat and the relative contributions of climate and population change

    Science.gov (United States)

    Liu, Zhao; Anderson, Bruce; Yan, Kai; Dong, Weihua; Liao, Hua; Shi, Peijun

    2017-03-01

    The frequency and intensity of extreme heat wave events have increased in the past several decades and are likely to continue to increase in the future under the influence of human-induced climate change. Exposure refers to people, property, systems, or other elements present in hazard zones that are thereby subject to potential losses. Exposure to extreme heat and changes therein are not just determined by climate changes but also population changes. Here we analyze output for three scenarios of greenhouse gas emissions and socio-economic growth to estimate future exposure change taking account of both climate and population factors. We find that for the higher emission scenario (RCP8.5-SSP3), the global exposure increases nearly 30-fold by 2100. The average exposure for Africa is over 118 times greater than it has been historically, while the exposure for Europe increases by only a factor of four. Importantly, in the absence of climate change, exposure is reduced by 75-95% globally and across all geographic regions, as compared with exposure under the high emission scenario. Under lower emission scenarios RCP4.5-SSP2 and RCP2.6-SSP1, the global exposure is reduced by 65% and 85% respectively, highlighting the efficacy of mitigation efforts in reducing exposure to extreme heat.

  4. 78 FR 78962 - Criteria for a Recommended Standard; Occupational Exposure to Heat and Hot Environments; Draft...

    Science.gov (United States)

    2013-12-27

    ... completed. 1. Name: 2. Gender: 3. Date of Birth: 4. Place of Birth (city, province, state, country): 5... result in occupational illnesses and injuries. Heat stress can result in heat-related illnesses such as heat stroke, heat exhaustion, heat cramps, or heat rashes. Heat can also increase the risk of injuries...

  5. Basal tolerance to heat and cold exposure of the spotted wing drosophila, Drosophila suzukii

    Directory of Open Access Journals (Sweden)

    Thomas Enriquez

    2017-03-01

    Full Text Available The spotted wing Drosophila, Drosophila suzukii, is a new pest in Europe and America which causes severe damages, mostly to stone fruit crops. Temperature and humidity are among the most important abiotic factors governing insect development and fitness. In many situations, temperature can become stressful thus compromising survival. The ability to cope with thermal stress depends on basal level of thermal tolerance. Basic knowledge on temperature-dependent mortality of D. suzukii is essential to facilitate management of this pest. The objective of the present study was to investigate D. suzukii basal cold and heat tolerance. Adults and pupae were subjected to six low temperatures (−5–7.5 °C and seven high temperatures (30–37 °C for various durations, and survival-time-temperature relationships were investigated. Data showed that males were globally more cold tolerant than females. At temperature above 5 °C, adult cold mortality became minor even after prolonged exposures (e.g., only 20% mortality after one month at 7.5 °C. Heat tolerance of males was lower than that of females at the highest tested temperatures (34, 35 and 37 °C. Pupae appeared much less cold tolerant than adults at all temperatures (e.g., Lt50 at 5° C: 4–5 d for adults vs. 21 h for pupae. Pupae were more heat tolerant than adults at the most extreme high temperatures (e.g., Lt50 at 37 °C: 30 min for adults vs. 4 h for pupae. The pupal thermal tolerance was further investigated under low vs. high humidity. Low relative humidity did not affect pupal cold survival, but it reduced survival under heat stress. Overall, this study shows that survival of D. suzukii under heat and cold conditions can vary with stress intensity, duration, humidity, sex and stage, and the methodological approach used here, which was based on thermal tolerance landscapes, provides a comprehensive description of D. suzukiithermal tolerance and limits.

  6. Effects of humid heat exposure in later sleep segments on sleep stages and body temperature in humans

    Science.gov (United States)

    Okamoto-Mizuno, Kazue; Tsuzuki, Kazuyo; Mizuno, Koh

    2005-03-01

    This study sought to investigate the effects of humid heat exposure in later sleep segments on sleep stages and body temperature in humans. The subjects were eight healthy males, from whom informed consent had been obtained. The experiments were carried out under three different sets of conditions: a control climate [air temperature (Ta)=26°C, relative humidity (RH)=50%] (C); a humid heat climate (Ta=32°C, RH=80%) (H); and a humid heat exposure in later sleep segments (C for the first 3 h 45 min, followed by a 30-min transition to H, which was then maintained for the last 3 h 45 min) (C H). Electroencephalogram, EOG, and mental electromyogram, rectal temperature (Tre), and skin temperature (Tsk) were continuously measured. The total amount of wakefulness was significantly increased in H compared to C H or C. Compared to C, wakefulness in C H and H was significantly increased during later sleep segments. Tre and mean Tsk were significantly higher in H than in C H or C. In C H, Tsk and Tre increased to levels equal to those observed in H after Ta and RH increase. Whole body sweat loss was significantly lower in C H and C than in H. These results suggest that humid heat exposure in the later sleep segment reduces thermal load as compared to full-night humid heat exposure. In daily life, the use of air conditioning in the initial sleep hours can protect sleep and thermoregulation.

  7. Hypothesis: Urbanization and exposure to urban heat islands contribute to increasing prevalence of kidney stones.

    Science.gov (United States)

    Goldfarb, David S; Hirsch, Jacqueline

    2015-12-01

    The prevalence of kidney stones is increasing worldwide. Various etiologies may in part explain this observation including increased prevalence of diabetes, obesity and the metabolic syndrome, increased dietary protein and salt content, and decreased dietary dairy products. We hypothesize an additional and novel potential contributor to increasing kidney stone prevalence: migration to urban settings, or urbanization, and resultant exposure of the population to the higher temperatures of urban heat islands (UHIs). Both urbanization and exposure to UHIs are worldwide, continuous trends. Because the difference in temperature between rural and urban settings is greater than the increase in temperature caused by global warming, the potential effect of urbanization on stone prevalence may be of greater magnitude. However, demonstration of a convincing link between urbanization and kidney stones is confounded by many variables simultaneously affected by migration to cities, such as changes in occupation, income, and diet. No data have yet been published supporting this proposed association. We explore the plausibility and limitations of this possible etiology of increasing kidney stone prevalence. Published by Elsevier Ltd.

  8. Does interspecific competition alter effects of early season ozone exposure on plants from wet grasslands? Results of a three-year experiment in open-top chambers

    NARCIS (Netherlands)

    Tonneijck, A.E.G.; Franzaring, J.; Brouwer, G.; Metselaar, K.; Dueck, T.A.

    2004-01-01

    Chronic effects of ozone on wet grassland species early in the growing season might be altered by interspecific competition. Individual plants of Holcus lanatus, Lychnis flos-cuculi, Molinia caerulea and Plantago lanceolata were grown in monocultures and in mixed cultures with Agrostis capillaris.

  9. Thermoregulation in complex situations: combined heat exposure, infectious fever and water deprivation

    Science.gov (United States)

    Blatteis, C. M.

    Heat exposure, infectious fever and water deprivation are stressors that, individually, produce disturbances in more than one regulated system, calling for diverse compensatory responses. A potential conflict is created when these stimuli are combined and impose concurrent stressful loads on the body because the homeostatic defenses mobilized against one are also partly needed against the other stressors. To learn how the competing demands of combined stressors for shared regulatory systems are met, rabbits were exposed to 32°C and 37°C (heat), administered lipopolysaccharide (Salmonella enteritidis LPS, 2 µg/kg, i.v.) in temperatures of 22°C or 27°C, or water-deprived for 1 or 2 days in 22°C or 27°C, in separate experiments. The corresponding controls were exposed to 22°C or 27°C, administered pyrogen-free saline i.v. in 22°C or 27°C, or normally hydrated in 22°C or 27°C. In subsequent experiments, two or all three of these treatments were applied concurrently. Core and ear skin temperatures and respiratory rates were monitored continuously. The results indicated that the concomitant needs of moderate heat exposure, fever and 1 day of water deprivation were generally met by the regulatory systems involved, but different patterns of thermoeffector activities were evoked and the eventual body temperature changes produced were different under each condition. However, when the test conditions were severe, their combined needs were not met adequately and the eventual compensatory response depended not only on the particular stimulus intensity, but also on the immediate importance for survival of the functions being defended. Thus, dehydration was the most dangerous factor to the physiological integrity of the animals. In sum, conflicting physiological stimuli appear to result in responses that are different from the responses to a single perturbation, the eventual output representing the resultant of the inputs rather than a singular output dictated by one

  10. Exposure to a heat wave under food limitation makes an agricultural insecticide lethal: a mechanistic laboratory experiment

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Janssens, Lizanne; Stoks, Robby

    2016-01-01

    variables. While the immediate effects of the heat wave were subtle, our results indicate the importance of delayed effects in shaping the total fitness impact of a heat wave when followed by pesticide exposure. Firstly, the combination of delayed negative effects of the heat wave and starvation...... for mortality could be explained by the cumulative metabolic depression caused by each of these stressors. Further studies with increased realism are needed to evaluate the consequences of the here-identified delayed synergisms at the level of populations and communities. This is especially important...

  11. Wet work in relation to occupational dermatitis

    NARCIS (Netherlands)

    Jungbauer, Franciscus Henricus Wilhelmus

    2004-01-01

    This thesis describes the nature and the quantity of work-related skin exposure in occupations where ‘wet work’ is performed. Activities that cause one or both hands to become wet, in contact with detergents or other skin irritating substances or activities that need to be done with occlusive gloves

  12. Use of electronic tongue for differentiation of tomato taste by cultivar, harvest maturity, and chilling or heating exposure

    Science.gov (United States)

    The objective of this research was to evaluate whether an electronic-tongue (etongue) could differentiate “taste” profiles of tomato fruit between different cultivars, harvest maturities, and postharvest chilling or heating exposure. The four cultivars included: two common commercial cultivars, ‘Tyg...

  13. The influence of occupational heat exposure on cognitive performance and blood level of stress hormones: a field study report.

    Science.gov (United States)

    Mazlomi, Adel; Golbabaei, Farideh; Farhang Dehghan, Somayeh; Abbasinia, Marzieh; Mahmoud Khani, Somayeh; Ansari, Mohammad; Hosseini, Mostafa

    2017-09-01

    This article aimed to investigate the effect of heat stress on cognitive performance and the blood concentration of stress hormones among workers of a foundry plant. Seventy workers within the exposed (35 people) and unexposed (35 people) groups were studied. The wet bulb globe temperature (WBGT) index was measured for heat stress assessment. The cognitive performance tests were conducted using the Stroop color word test (SCWT) before and during working hours. For the assessment of the serum level of cortisol and the plasma level of adrenaline and noradrenaline, blood samples were taken during working hours from both groups. Only for SCWT III was there a significant relationship between heat stress and test duration, error rate and reaction time. The laboratory test results revealed significantly higher concentrations of cortisol, adrenaline and noradrenaline in the exposed subjects than in the unexposed group. There existed a positive correlation between cortisol, adrenaline, noradrenaline and WBGT index and also test duration and reaction time of SCWT III, and number of errors of SCWT I, SCWT II and SCWT III during work. Heat stress can lead to an increase in the blood level of stress hormones, resulting in cognitive performance impairment.

  14. Energy efficiency ground-source energy system, Environmental Protection Law, article 'Heat and cold storage, value for money'; Energierendement bodemenergiesysteem, Wet milieubeheer, artikel 'WKO, waar voor je geld'

    Energy Technology Data Exchange (ETDEWEB)

    Lambregts, E.G.M.; Teunissen, P.O.M.; Beukenhorst, E.

    2013-01-15

    Upscaling of ground-source energy systems can contribute to heat and cold storage systems and thus reduce CO2 emission for the Amsterdam municipality. Based on the results of the project 'Heat and cold storage; Value for money' a proposal was made to the Dutch Ministry of Infrastructure and Environment to include a regulation 'energy efficiency heat and cold storage' in the Environmental Protection Law [Dutch] In het kader van de CO2 doelstelling van Amsterdam om 40% CO2 te reduceren in 2025 t.o.v. van 1990 wordt de verdere opschaling van de techniek bodemenergiesysteem gezien als een techniek die in belangrijke mate kan bijdragen aan de pijler 'transitie duurzame warmte en koude'. Op landelijk en gemeentelijk niveau werd gesignaleerd dat (open) bodemenergiesystemen in de exploitatiefase veelal onvoldoende functioneerden. In dit rapport wordt op basis van de resultaten van het project 'WKO, waar voor je geld' een voorstel aan het Ministerie van I en M gedaan om een voorschrift 'energierendement wko' op te nemen in het Activiteitenbesluit Wet milieubeheer.

  15. Evaluation of Biomarkers of Exposure in Smokers Switching to a Carbon-Heated Tobacco Product: A Controlled, Randomized, Open-Label 5-Day Exposure Study.

    Science.gov (United States)

    Lüdicke, Frank; Haziza, Christelle; Weitkunat, Rolf; Magnette, John

    2016-07-01

    Tobacco harm reduction aims to provide reduced risk alternatives to adult smokers who would otherwise continue smoking combustible cigarettes (CCs). This randomized, open-label, three-arm, parallel-group, single-center, short-term confinement study aimed to investigate the effects of exposure to selected harmful and potentially harmful constituents (HPHCs) of cigarette smoke in adult smokers who switched to a carbon-heated tobacco product (CHTP) compared with adult smokers who continued to smoke CCs and those who abstained from smoking for 5 days. Biomarkers of exposure to HPHCs, including nicotine and urinary excretion of mutagenic material, were measured in 24-hour urine and blood samples in 112 male and female Caucasian smokers switching from CCs to the CHTP ad libitum use. Puffing topography was assessed during product use. Switching to the CHTP or smoking abstinence (SA) resulted in marked decreases from baseline to Day 5 in all biomarkers of exposure measured, including carboxyhemoglobin (43% and 55% decrease in the CHTP and SA groups, respectively). The urinary excretion of mutagenic material was also markedly decreased on Day 5 compared with baseline (89% and 87% decrease in the CHTP and SA groups, respectively). No changes in biomarkers of exposure to HPHCs or urinary mutagenic material were observed between baseline and Day 5 in the CC group. Our results provide clear evidence supporting a reduction in the level of exposure to HPHCs of tobacco smoke in smokers who switch to CHTP under controlled conditions, similar to that observed in SA. The reductions observed in biomarkers of exposure to HPHCs of tobacco smoke in this short-term study could potentially also reduce the incidence of cancer, cardiovascular and respiratory diseases in those smokers who switch to a heated tobacco product. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.

  16. Reduced Exposure to Harmful and Potentially Harmful Smoke Constituents With the Tobacco Heating System 2.1.

    Science.gov (United States)

    Lüdicke, Frank; Baker, Gizelle; Magnette, John; Picavet, Patrick; Weitkunat, Rolf

    2017-02-01

    Heating rather than burning tobacco reduces levels of harmful and potentially harmful constituents, and consumer products using this approach aim to reduce exposure to tobacco toxicants. The Tobacco Heating System (THS) version 2.1 has been enhanced from earlier prototypes with an improved heat control and sensorial experience and thereby user acceptance. Exposure measurements are required to determine whether it may be possible to reduce the individual health risk compared to smoking combustible cigarettes (CCs). This controlled clinical study randomly assigned 40 smokers to either a group continuing to use of their own CC brand (n = 20) or a group switching to THS 2.1 (n = 20) for 5 days. Biomarkers of exposure were measured at baseline and on day 1 through day 5. Product consumption, Human Puffing Topography, the occurrence of adverse events, and an assessment of subjective effects, such as smoking satisfaction and enjoyment of respiratory tract sensations, were also determined. The group of smokers who switched to THS 2.1 adapted their puffing behavior initially through longer puff duration and more puffs. During the duration of the study, total puff volume returned to baseline levels and the mean daily product consumption increased but with similar nicotine exposure compared to baseline CC use. Biomarkers of exposure to tobacco smoke toxicants which inform product risk assessment were significantly reduced with THS use compared to the CC group. THS 2.1 users experienced less reinforcing effects with THS 2.1 than with their own cigarette brand. THS 2.1 is a promising alternative to smoking CCs. Notwithstanding possible use adaption through consumption or puffing behavior, the exposure to harmful smoke constituents was markedly reduced with the new heated tobacco platform. Exposure markers to harmful and potentially harmful smoke constituents were lowered with the THS 2.1. Heating tobacco instead of burning can offer a potentially lower risk of delivering

  17. Characteristics of wet work in the cleaning industry

    NARCIS (Netherlands)

    Jungbauer, F H W; Van Der Harst, J J; Schuttelaar, M L; Groothoff, J W; Coenraads, P J

    Wet work is the main cause of occupational contact dermatitis in the cleaning industry. Dermatologists and occupational physicians need to base their primary and secondary prevention for workers in the cleaning industry on the characteristics of wet work exposures. We quantified the burden of wet

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

    Directory of Open Access Journals (Sweden)

    Crystal Romeo Upperman

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

  19. Combined active and passive heat exposure induced heat acclimation in a soccer referee before 2014 FIFA World Cup.

    Science.gov (United States)

    Ruddock, A D; Thompson, S W; Hudson, S A; James, C A; Gibson, O R; Mee, J A

    2016-01-01

    The 2014 FIFA World Cup was held in Brazil, where the climatic conditions presented a significant thermoregulatory and perceptual challenge to those unfamiliar with the heat and humidity. This case report documents the adaptation induced by a novel mixed methods (isothermic and passive) heat acclimation (HA) regime for a northern European professional soccer match official prior to the tournament. The intervention involved 13 HA sessions over an 18 day period comprising five isothermic HA sessions whereby intermittent running was used to target and maintain tympanic temperature (Tytemp) at 38 °C for 90 min, and seven passive HA sessions of 48 °C water bathing for 30 min. The athlete performed a heat stress test (HST) (35 min running at four incremental intensities in 30 °C) and a repeated high-intensity running test (as many 30 s self-paced efforts as possible, to a maximum of 20, with 30 s passive recovery) before and after the intervention. The mixed methods HA regime increased plasma volume (+7.1 %), and sweat loss (+0.9 L h(-1)), reduced exercising Tytemp (-0.6 °C), and mean body temperature (-0.5 °C). High-intensity running performance improved after HA (+29 %), as did the perception of thermal comfort during exercise (-0.3 units). This data evidences the effectiveness of a practical, mixed methods HA strategy, remotely implemented around training and competition, at inducing the heat acclimation phenotype in a high-level soccer match official.

  20. Evaluation of wetting ability of five new saliva substitutes on ...

    African Journals Online (AJOL)

    Introduction: The aim of this study was to evaluate & compare the wetting ability of five saliva substitutes & distilled water on heat-polymerized acrylic resin. Contact angle of the saliva substitute on denture base can be taken as an indicator of wettability. Good wetting of heat-polymerized acrylic resin is critical for optimum ...

  1. Heat Stress

    Science.gov (United States)

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

  2. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  3. Deep Heat Mining - Development of the hot-dry-rock and hot-wet-rock technologies for the production of heat and power in Switzerland; Deep Heat Mining. Entwicklung der Hot-Dry-Rock / Hot-Wet-Rock Technologie zur Strom- und Waermeproduktion in der Schweiz

    Energy Technology Data Exchange (ETDEWEB)

    Haering, M. O.; Hopkirk, R. J.; Rybach, L.; Wilhelm, J.; Minder, R.; Vuataz, F.

    2002-07-01

    This report for the Swiss Federal Office of Energy (SFOE) presents the results of activities in the year 2002 concerning the two geothermal technologies at present being worked on in Switzerland. These include the results from the assessment of the Otterbach 2 research bore-hole near Basle, which indicates that temperatures of 210 -220{sup o} C can be reckoned with at a depth of 5,000 metres. The measurement concepts for the recording of seismic and micro-seismic activity at this site are presented. The choice and financing of the site for the geothermal power station in Basle that is to use this deep-heat potential are described. Also, the planning of the proposed geothermal plant in Geneva is discussed. The frame of reference for a systematic examination of the potential offered by geothermal resources in Switzerland, which was elaborated in an internal study, is presented. The report also lists contributions to the information on geothermal energy for professional circles as well as for the general public that were made during the reporting period.

  4. Heat

    CERN Document Server

    Lawrence, Ellen

    2016-01-01

    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  5. Double Exposure and the Climate Gap: Changing demographics and extreme heat in Ciudad Juárez, Mexico

    Science.gov (United States)

    Collins, Timothy W.; McDonald, Yolanda J.; Aldouri, Raed; Aboargob, Faraj; Eldeb, Abdelatif; Aguilar, María de Lourdes Romo; Velázquez-Angulo, Juárez Gilberto

    2013-01-01

    Scholars have recognized a climate gap, wherein poor communities face disproportionate impacts of climate change. Others have noted that climate change and economic globalization may mutually affect a region or social group, leading to double exposure. This paper investigates how current and changing patterns of neighborhood demographics are associated with extreme heat in the border city of Juárez, Mexico. Many Juárez neighborhoods are at-risk to triple exposures, in which residents suffer due to the conjoined effects of the global recession, drug war violence, and extreme heat. Due to impacts of the recession on maquiladora employment and the explosion of drug violence (since 2008), over 75% of neighborhoods experienced decreasing population density between 2000 and 2010 and the average neighborhood saw a 40% increase in the proportion of older adults. Neighborhoods with greater drops in population density and increases in the proportion of older residents over the decade are at significantly higher risk to extreme heat, as are neighborhoods with lower population density and lower levels of education. In this context, triple exposures are associated with a climate gap that most endangers lower socioeconomic status and increasingly older aged populations remaining in neighborhoods from which high proportions of residents have departed. PMID:25642135

  6. Double Exposure and the Climate Gap: Changing demographics and extreme heat in Ciudad Juárez, Mexico.

    Science.gov (United States)

    Grineski, Sara E; Collins, Timothy W; McDonald, Yolanda J; Aldouri, Raed; Aboargob, Faraj; Eldeb, Abdelatif; Aguilar, María de Lourdes Romo; Velázquez-Angulo, Juárez Gilberto

    2015-02-01

    Scholars have recognized a climate gap, wherein poor communities face disproportionate impacts of climate change. Others have noted that climate change and economic globalization may mutually affect a region or social group, leading to double exposure. This paper investigates how current and changing patterns of neighborhood demographics are associated with extreme heat in the border city of Juárez, Mexico. Many Juárez neighborhoods are at-risk to triple exposures, in which residents suffer due to the conjoined effects of the global recession, drug war violence, and extreme heat. Due to impacts of the recession on maquiladora employment and the explosion of drug violence (since 2008), over 75% of neighborhoods experienced decreasing population density between 2000 and 2010 and the average neighborhood saw a 40% increase in the proportion of older adults. Neighborhoods with greater drops in population density and increases in the proportion of older residents over the decade are at significantly higher risk to extreme heat, as are neighborhoods with lower population density and lower levels of education. In this context, triple exposures are associated with a climate gap that most endangers lower socioeconomic status and increasingly older aged populations remaining in neighborhoods from which high proportions of residents have departed.

  7. Graphene transport properties upon exposure to PMMA processing and heat treatments

    DEFF Research Database (Denmark)

    Gammelgaard, Lene; Caridad, Jose; Cagliani, Alberto

    2014-01-01

    The evolution of graphene's electrical transport properties due to processing with the polymer polymethyl methacrylate (PMMA) and heat are examined in this study. The use of stencil (shadow mask) lithography enables fabrication of graphene devices without the usage of polymers, chemicals or heat......, allowing us to measure the evolution of the electrical transport properties during individual processing steps from the initial as-exfoliated to the PMMA-processed graphene. Heating generally promotes the conformation of graphene to SiO2 and is found to play a major role for the electrical properties...... that flakes conforming poorly to the substrate will have a higher carrier mobility which will however be reduced as heat treatment enhance the conformation. We finally show the electrical properties of graphene to be reversible upon heat treatments in air up to 200°C....

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

    Science.gov (United States)

    Stevens, Catherine; Thomas, Bart; Grommen, Mart

    2015-04-01

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

  9. An experimental study of the effects of combined exposure to microwave and heat on gene expression and sperm parameters in mice

    Directory of Open Access Journals (Sweden)

    Faezeh A Gohari

    2017-01-01

    Full Text Available Objectives: Separate exposure to microwaves (MWs or heat had effects on expression levels of Bax and Bcl-2 and sperm parameters in studied group. Aims: The objectives of this research were to determine the effects of separate and combined exposure to 900-MHz MW (as representative of cell phone radiation and heat on gene expression and spermogram of male mice. Settings and Design: This experimental animal study was conducted in the school of public health. Materials and Methods: The study was done on 12 male mice randomly divided into four groups (21–23 g: control, test group 1 with separate exposure to 900-MHz MW, test group 2 with separate exposure to hot and sultry climate, and test group 3 with simultaneous whole body exposures to 900-MHz MW and hot and sultry climate. In all studied groups, gene expression and sperm parameters were measured. Results: Tissue samples in all test groups showed integrity of the seminiferous tubule followed by all types of germ line cells. Significant increases in the number of dead sperms in mice with separate exposure to heat were observed in comparison with the other studied groups (P < 0.05. The ratio of Bax expression was elevated to 0.015 ± 0.006 in mice after combined exposures to 900-MHz MW and heat. Conclusion: Separate and combined exposure to 900-MHz MW and heat may induce adverse effects on sperm parameters and gene expression of studied male mice.

  10. Effect of heat exposure and exercise on food intake regulation: A randomized crossover study in young healthy men.

    Science.gov (United States)

    Faure, Cécile; Charlot, Keyne; Henri, Stéphane; Hardy-Dessources, Marie-Dominique; Hue, Olivier; Antoine-Jonville, Sophie

    2016-10-01

    The effect of physical activity on food intake regulation may be moderated by environmental temperature. The aim of the study was to determine the single and combined effects of metabolic activity and temperature on energy intake and its hormonal regulation. A randomized crossover study was conducted in the laboratory. Ten healthy and physically active young Afro-Caribbean men participated in four experimental sessions (rest at 22°C and 31°C and cycling at 60% of their maximal oxygen uptake at 22°C and 31°C, all for 40 min). Each test period was followed by a 30-min recovery period and then an ad libitum meal. The main outcome measures were energy balance, subjective appetite, and plasma pancreatic polypeptide (PP), cholecystokinin (CCK) and ghrelin concentrations. Relative energy intake was significantly decreased whereas plasma PP was increased in the exercise conditions (p=0.004 and p=0.002, respectively). Postprandial levels of CCK were elevated only in the rest conditions. Exposure to heat induced a decrease in plasma ghrelin (p=0.031). Exercise induced a short-term energy deficit. However, modifications in the hormonal regulation of food intake in response to short-term heat or heat and exercise exposure seem to be minor and did not induce changes in energy intake. This trial was registered at clinicaltrials.gov as NCT02157233. Copyright © 2016. Published by Elsevier Inc.

  11. The Heat Exposure Integrated Deprivation Index (HEIDI): A data-driven approach to quantifying neighborhood risk during extreme hot weather.

    Science.gov (United States)

    Krstic, Nikolas; Yuchi, Weiran; Ho, Hung Chak; Walker, Blake B; Knudby, Anders J; Henderson, Sarah B

    2017-12-01

    Mortality attributable to extreme hot weather is a growing concern in many urban environments, and spatial heat vulnerability indexes are often used to identify areas at relatively higher and lower risk. Three indexes were developed for greater Vancouver, Canada using a pool of 20 potentially predictive variables categorized to reflect social vulnerability, population density, temperature exposure, and urban form. One variable was chosen from each category: an existing deprivation index, senior population density, apparent temperature, and road density, respectively. The three indexes were constructed from these variables using (1) unweighted, (2) weighted, and (3) data-driven Heat Exposure Integrated Deprivation Index (HEIDI) approaches. The performance of each index was assessed using mortality data from 1998-2014, and the maps were compared with respect to spatial patterns identified. The population-weighted spatial correlation between the three indexes ranged from 0.68-0.89. The HEIDI approach produced a graduated map of vulnerability, whereas the other approaches primarily identified areas of highest risk. All indexes performed best under extreme temperatures, but HEIDI was more useful at lower thresholds. Each of the indexes in isolation provides valuable information for public health protection, but combining the HEIDI approach with unweighted and weighted methods provides richer information about areas most vulnerable to heat. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Rapid shift in thermal resistance between generations through maternal heat exposure

    NARCIS (Netherlands)

    Zizzari, Z.V.; Ellers, J.

    2014-01-01

    Given the current rapid climate change, understanding the mechanisms underlying heat tolerance and its plasticity is an important goal of global change biology. Soil fauna communities are especially vulnerable because of their limited dispersal ability. It is generally recognized that

  13. Convex optimization of MRI exposure for mitigation of RF-heating from active medical implants.

    Science.gov (United States)

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2015-09-21

    Local RF-heating of elongated medical implants during magnetic resonance imaging (MRI) may pose a significant health risk to patients. The actual patient risk depends on various parameters including RF magnetic field strength and frequency, MR coil design, patient's anatomy, posture, and imaging position, implant location, RF coupling efficiency of the implant, and the bio-physiological responses associated with the induced local heating. We present three constrained convex optimization strategies that incorporate the implant's RF-heating characteristics, for the reduction of local heating of medical implants during MRI. The study emphasizes the complementary performances of the different formulations. The analysis demonstrates that RF-induced heating of elongated metallic medical implants can be carefully controlled and balanced against MRI quality. A reduction of heating of up to 25 dB can be achieved at the cost of reduced uniformity in the magnitude of the B(1)(+) field of less than 5%. The current formulations incorporate a priori knowledge of clinically-specific parameters, which is assumed to be available. Before these techniques can be applied practically in the broader clinical context, further investigations are needed to determine whether reduced access to a priori knowledge regarding, e.g. the patient's anatomy, implant routing, RF-transmitter, and RF-implant coupling, can be accepted within reasonable levels of uncertainty.

  14. Effect of 25 cycles of launch pad exposure and simulated mission heating on space shuttle reusable surface insulation coated with reaction cured glass

    Science.gov (United States)

    Ransone, P. O.; Morrison, J. D.; Minster, J. E.

    1979-01-01

    Tiles of space shuttle reusable surface insulation coated with reaction cured glass were subjected to 25 cycles of launch pad exposure and simulated mission heating. The coating could not withstand the environment without cracking. Water absorption after cracking reached as high as 150 weight percent. Exposure of insulation fibers beneath the coating to contaminants dissolved in absorbed water initiated fiber degradation.

  15. Ocular temperature elevation induced by threshold in vivo exposure to 1090-nm infrared radiation and associated heat diffusion.

    Science.gov (United States)

    Yu, Zhaohua; Schulmeister, Karl; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per G

    2014-01-01

    An in vivo exposure to 197  W/cm 2 1090-nm infrared radiation (IRR) requires a minimum 8 s for cataract induction. The present study aims to determine the ocular temperature evolution and the associated heat flow at the same exposure conditions. Two groups of 12 rats were unilaterally exposed within the dilated pupil with a close to collimated beam between lens and retina. Temperature was recorded with thermocouples. Within 5 min after exposure, the lens light scattering was measured. In one group, the temperature rise in the exposed eye, expressed as a confidence interval (0.95), was 11±3°C at the limbus, 16±6°C in the vitreous behind lens, and 16±7°C on the sclera next to the optic nerve, respectively. In the other group, the temperature rise in the exposed eye was 9±1°C at the limbus and 26±11°C on the sclera next to the optic nerve, respectively. The difference of forward light scattering between exposed and contralateral not exposed eye was 0.01±0.09 tEDC. An exposure to 197  W/cm 2 1090-nm IRR for 8 s induces a temperature increase of 10°C at the limbus and 26°C close to the retina. IRR cataract is probably of thermal origin.

  16. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  17. Influence of Cold Exposure on Ventilation, Respiratory Heat Loss, and Pulmonary Deposition/Clearance

    Science.gov (United States)

    1990-06-25

    AFR 190-1 Distribution Unlimited ERNEST A. HAYGOOD, Ist Lt, USAF Executive Officer, Civilian Institution Programs 13. ABSTRACT (Maximum 200 words) DTIC...the unanesthetized dog. Am. i. Physiol. 213:547-556, 1967. 46. Hemingway , A., T. Rasmussen, H. Wikoff and A.T. Rasmussen. Effects of heating

  18. Mold management of wetted carpet.

    Science.gov (United States)

    Ong, Kee-Hean; Dixit, Anupma; Lewis, Roger D; MacDonald Perkins, Maureen; Backer, Denis; Condoor, Sridhar; Emo, Brett; Yang, Mingan

    2014-01-01

    This study evaluated the growth and removal of fungi on wetted carpet using newly designed technologies that rely on physical principles of steam, heat, and fluid flow. Sixty samples of carpet were embedded with heat-treated house dust, followed by embedding, wearing with a hexapod, and wetting. Samples were inoculated using a liquid suspension of Cladosporium sphaerospermum prior to placement over a water-saturated foam pad. Incubation times were 24 hr, 7 days, and 30 days. Cleaning was performed using three methods; high-flow hot water extraction, hot water and detergent, and steam. Fungal loading increased from approximately 1500 colony forming units per area (CFU/cm(2)) in 24 hr to a maximum of approximately 10,200 CFU/cm(2) after 7 days with a slight decline to 9700 CFU/cm(2) after 30 days incubation. Statistically significant differences were found among all three methods for removal of fungi for all three time periods (p mold spore decline from wetted carpet after 24 hr and 30 days, and over 92% efficiency after 7 days. The alternative methods exhibited lower efficiencies with a decline over time, from a maximum of 82% and 81% at 24 hr down to 60% and 43% at 30 days for detergent-hot water and high-flow, hot water extraction, respectively. The net effect of the mold management study demonstrates that while steam has a consistent fungal removal rate, the detergent and high-flow, hot water methods decline in efficiency with increasing incubation time.

  19. Urban "accidental" wetlands mediate water quality and heat exposure for homeless populations in a desert city

    Science.gov (United States)

    Palta, M.

    2015-12-01

    In urban settings where humans interact in complex ways with ecosystems, there may be hidden or unanticipated benefits (services) or harm (disservices) conferred by the built environment. We examined interactions of a highly vulnerable population, the homeless, with urban waterways and wetlands in the desert city of Phoenix, Arizona, U.S.A. Climate change models project increases in heat, droughts, and extreme floods for the southwestern U.S. These projected changes pose a number of problems for sustainability and quality of future water supply, and the ability of human populations to mitigate heat stress and avoid fatalities. Urban wetlands that are created "accidentally" (by water pooling in abandoned areas of the landscape) have many structural (e.g., soils and hydrology) and functional (e.g., high denitrification) elements that mimic natural, unaltered aquatic systems. Accidental wetland systems in the dry bed of the Salt River, fed by storm and waste water from urban Phoenix, are located within economically depressed sections of the city, and show the potential for pollutant and heat mitigation. We used a mixed-method socio-ecological approach to examine wetland ecosystem functions and the ways in which homeless populations utilize Salt River wetlands for ecosystem services. Interviews and trash surveys indicated that homeless people are accessing and utilizing the wetlands as a source of running water, for sanitary and heat mitigation services, and for recreation and habitation. Environmental monitoring demonstrated that the wetlands can provide a reliable source of running water, nutrient and pathogen removal, heat mitigation, and privacy, but they may also pose a health risk to individuals coming in contact with the water through drinking or bathing. Whether wetlands provided a net benefit vs. harm varied according to site, season, and particular service, and several tradeoffs were identified. For example, heat is highest during the summer storm season

  20. Immune and inflammatory responses of Australian firefighters after repeated exposures to the heat.

    Science.gov (United States)

    Walker, Anthony; Keene, Toby; Argus, Christos; Driller, Matthew; Guy, Joshua H; Rattray, Ben

    2015-01-01

    When firefighters work in hot conditions, altered immune and inflammatory responses may increase the risk of a cardiac event. The present study aimed to establish the time course of such responses. Forty-two urban firefighters completed a repeat work protocol in a heat chamber (100 ± 5°C). Changes to leukocytes, platelets, TNFα, IL-6, IL-10, LPS and CRP were evaluated immediately post-work and also after 1 and 24 h of rest. Increases in core temperatures were associated with significant increases in leukocytes, platelets and TNFα directly following work. Further, platelets continued to increase at 1 h (+31.2 ± 31.3 × 10(9) l, p work tasks in the heat. This is particularly relevant during multi-day deployments following natural disasters. Practitioner Summary: Firefighters regularly re-enter fire affected buildings or are redeployed to further operational tasks. Should work in the heat lead to sustained immune and inflammatory changes following extended rest periods, incident controllers should plan appropriate work/rest cycles to minimise these changes and any subsequent risks of cardiac events.

  1. Clostridium thermocellum Transcriptomic Profiles after Exposure to Furfural or Heat Stress

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Charlotte M [ORNL; Yang, Shihui [ORNL; Rodriguez, Jr., Miguel [ORNL; Ma, Qin [University of Georgia, Athens, GA; Johnson, Courtney M [ORNL; Dice, Lezlee T [ORNL; Xu, Ying [University of Georgia, Athens, GA; Brown, Steven D [ORNL

    2013-01-01

    Background The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP)biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A previous C. thermocellum ethanol stress study showed that largest transcriptomic response was in genes and proteins related to nitrogen uptake and metabolism. Results In this study, C. thermocellum was grown to mid-exponential phase and treated with furfural or heat to a final concentration of 3 g.L-1 or 68 C respectively to investigate general and specific physiological and regulatory stress responses. Samples were taken at 10, 30, 60 and 120 min post-shock, and from untreated control fermentations, for transcriptomic analyses and fermentation product determinations and compared to a published dataset from an ethanol stress study. Urea uptake genes were induced following furfural stress, but not to the same extent as ethanol stress and transcription from these genes was largely unaffected by heat stress. The largest transcriptomic response to furfural stress was genes for sulfate transporter subunits and enzymes in the sulfate assimilatory pathway, although these genes were also affected late in the heat and ethanol stress responses. Lactate production was higher in furfural treated culture, although the lactate dehydrogenase gene was not differentially expressed under this condition. Other redox related genes such as a copy of the rex gene, a bifunctional acetaldehyde-CoA/alcohol dehydrogenase and adjacent genes did show lower expression after furfural stress compared to the control, heat and ethanol fermentation profiles. Heat stress induced expression from chaperone related genes and overlap was observed with the responses to the other stresses. This study suggests the

  2. Exposure to heat-inactivated Trichophyton rubrum resulting in a limited immune response of human keratinocytes.

    Science.gov (United States)

    Huang, Xiao-Qiang; Yi, Jin-Ling; Yin, Song-Chao; Chen, Rong-Zhang; Li, Mei-Rong; Gong, Zi-Jian; Lai, Wei; Chen, Jian

    2013-01-01

    Trichophyton rubrum (T. rubrum) represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that it may result from the failure of epithelial cells to recognize T. rubrum effectively and initiate effective immune responses. The C-type lectin receptors (CLR) and toll-like receptors (TLR) are the two major pattern recognition receptors (PRRs) that recognize fungal components. Therefore, the purpose of the study was to analyze the expression of those PRRs and the cytokines in HaCaT cells stimulated with heat-inactivated T. rubrum conidia and hyphae, respectively. HaCaT cells were unstimulated or stimulated with heat-inactivated T. rubrum conidia and hyphae (1×10(6) and 1.5×10(5) colony-forming unit (CFU) in 2 ml medium, respectively) for 6, 12 and 24 hours. The mRNA expression of PRRs involved in recognizing fungal pathogen-associated molecular patterns (PAMPs) and signaling molecules were measured by quantitative reverse transcription polymerase chain reaction (RT-PCR). Meanwhile, surface toll-like receptor (TLR) 2, TLR4 and Dectin-1 were analyzed by fluorescence-activated cell sorter (FACS) 24 hours after treatment. The cytokines were detected in cell culture supernatants of HaCaT cells in 12 and 24 hours after treatment. HaCaT cells constitutively expressed mRNA of membrane-bound TLR1, 2, 4 and 6, Dectin1 and DC-SIGN, but not Dectin-2 or Mincle. Heat-killed T. rubrum did not significantly upregulate gene transcriptions of the PRRs of HaCaT cells. Heat-inactivated T. rubrum conidia significantly reduced the surface expression of TLR2 and Dectin-1, and suppressed the secretions of interferon-inducible protein-10 (IP-10) and monocyte chemotactic protein-1 (MCP-1) of HaCaT cells, while heat-killed T. rubrum hyphae significantly induced the secretions of IP-10 and MCP-1. The cell-wall antigens of T. rubrum fail to activate transcriptional expression of PRRs and

  3. Assessment of heat production, heat loss, and core temperature during nitrous oxide exposure: a new paradigm for studying drug effects and opponent responses.

    Science.gov (United States)

    Kaiyala, Karl J; Ramsay, Douglas S

    2005-03-01

    Studies using core temperature (T(c)) have contributed greatly to theoretical explanations of drug tolerance and its relationship to key features of addiction, including dependence, withdrawal, and relapse. Many theoretical accounts of tolerance propose that a given drug-induced psychobiological disturbance elicits opponent responses that contribute to tolerance development. This proposal and its theoretical extensions (e.g., conditioning as a mechanism of chronic tolerance) have been inferred from dependent variables, such as T(c), which represent the summation of multiple underlying determinants. Direct measurements of determinants could increase the understanding of opponent processes in tolerance, dependence, and withdrawal. The proximal determinants of T(c) are metabolic heat production (HP) and heat loss (HL). We developed a novel system for simultaneously quantifying HP (indirect calorimetry), HL (direct gradient layer calorimetry), and T(c) (telemetry) during steady-state administrations of nitrous oxide (N(2)O), an inhalant with abuse potential that has been previously used to study acute and chronic tolerance development to its hypothermia-inducing property. Rats were administered 60% N(2)O (n = 18) or placebo gas (n = 16) for 5 h after a 2-h placebo baseline exposure. On average, N(2)O rapidly but transiently lowered HP and increased HL, each by approximately 16% (P HL) after becoming hypothermic such that acute tolerance developed, i.e., T(c) rose despite continued drug administration. This work is the first to directly quantify the thermal determinants of T(c) during administration of a drug of abuse and establishes a new paradigm for studying opponent processes involved in acute and chronic hypothermic tolerance development.

  4. Wetting, Prewetting and Superfluidity

    OpenAIRE

    Taborek, P.

    2009-01-01

    Experiments on adsorption and wetting of quantum fluids (4He and 3He) on weakly binding alkali metal substrates are reviewed. Helium on weak substrates can undergo a variety of phase transitions including wetting, prewetting, layering, and liquid-vapor transitions. Another characteristic feature of weak substrates is the absence of an immobile quasi solid layer which is present on all conventional strong substrates. Both the absence of the immobile layer and the interaction with surface phase...

  5. Exposure to Extreme Heat Events Is Associated with Increased Hay Fever Prevalence among Nationally Representative Sample of US Adults: 1997-2013.

    Science.gov (United States)

    Upperman, Crystal Romeo; Parker, Jennifer D; Akinbami, Lara J; Jiang, Chengsheng; He, Xin; Murtugudde, Raghuram; Curriero, Frank C; Ziska, Lewis; Sapkota, Amir

    Warmer temperature can alter seasonality of pollen as well as pollen concentration, and may impact allergic diseases such as hay fever. Recent studies suggest that extreme heat events will likely increase in frequency, intensity, and duration in coming decades in response to changing climate. The overall objective of this study was to investigate if extreme heat events are associated with hay fever. We linked National Health Interview Survey (NHIS) data from 1997 to 2013 (n = 505,386 respondents) with extreme heat event data, defined as days when daily maximum temperature (TMAX) exceeded the 95th percentile values of TMAX for a 30-year reference period (1960-1989). We used logistic regression to investigate the associations between exposure to annual and seasonal extreme heat events and adult hay fever prevalence among the NHIS respondents. During 1997-2013, hay fever prevalence among adults 18 years and older was 8.43%. Age, race/ethnicity, poverty status, education, and sex were significantly associated with hay fever status. We observed that adults in the highest quartile of exposure to extreme heat events had a 7% increased odds of hay fever compared with those in the lowest quartile of exposure (odds ratios: 1.07, 95% confidence interval: 1.02-1.11). This relationship was more pronounced for extreme heat events that occurred during spring season, with evidence of an exposure-response relationship (P trend < .01). Our data suggest that exposure to extreme heat events is associated with increased prevalence of hay fever among US adults. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. All rights reserved.

  6. Transcriptional response of the mussel Mytilus galloprovincialis (Lam. following exposure to heat stress and copper.

    Directory of Open Access Journals (Sweden)

    Alessandro Negri

    Full Text Available Global warming is a major factor that may affect biological organization, especially in marine ecosystems and in coastal areas that are particularly subject to anthropogenic pollution. We evaluated the effects of simultaneous changes in temperature and copper concentrations on lysosomal membrane stability (N-acetyl-hexosaminidase activity and malondialdehyde accumulation (MDA in the gill of the blue mussel Mytilus galloprovincialis (Lam.. Temperature and copper exerted additive effects on lysosomal membrane stability, exacerbating the toxic effects of metal cations present in non-physiological concentrations. Mussel lysosomal membrane stability is known to be positively related to scope for growth, indicating possible effects of increasing temperature on mussel populations in metal-polluted areas. To clarify the molecular response to environmental stressors, we used a cDNA microarray with 1,673 sequences to measure the relative transcript abundances in the gills of mussels exposed to copper (40 µg/L and a temperature gradient (16°C, 20°C, and 24°C. In animals exposed only to heat stress, hierarchical clustering of the microarray data revealed three main clusters, which were largely dominated by down-regulation of translation-related differentially expressed genes, drastic up-regulation of protein folding related genes, and genes involved in chitin metabolism. The response of mussels exposed to copper at 24°C was characterized by an opposite pattern of the genes involved in translation, most of which were up-regulated, as well as the down-regulation of genes encoding heat shock proteins and "microtubule-based movement" proteins. Our data provide novel information on the transcriptomic modulations in mussels facing temperature increases and high copper concentrations; these data highlight the risk of marine life exposed to toxic chemicals in the presence of temperature increases due to climate change.

  7. Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

    Directory of Open Access Journals (Sweden)

    Brianna Larsen

    Full Text Available This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36 were matched and allocated to either the CON (19°C or HOT (33°C condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc, and skin temperature (Tsk were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of

  8. Multiple Days of Heat Exposure on Firefighters’ Work Performance and Physiology

    Science.gov (United States)

    Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

    2015-01-01

    This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants’ doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants’ work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological

  9. Effects of heat treatments and UV exposures on mechanical properties of 3D printed acrylonitrile butadiene styrene specimens

    Science.gov (United States)

    Hughes, Shawn M.; Alamir, Mohammed; Neas, Brian; Alzahrani, Naif; Asmatulu, Ramazan

    2017-04-01

    Over the last few years, tremendous amount of research efforts has been conducted on 3D printing materials, methods and systems. Various 3D printer materials in different size, shape and geometry can be used for advanced designs, modeling, and manufacturing for different industrial applications. In the present study, dog bone shape specimen was designed via a CATIA CAD model, and then printed by a 3D printer using a polymeric filament (acrylonitrile butadiene styrene - ABS). Some of the prepared samples were heat treated at 40 °C, 60 °C, and 80 °C for 30 minutes, while the others were exposed to the UV light in a chamber for 0, 5, 10, 15 and 20 days. The surface and mechanical properties of the conditioned samples were determined using water contact angle and tensile test units, respectively. The test results indicated that the heat treatment process increased the mechanical properties; however, the UV exposure tests significantly reduced the water contact angle and properties of the samples. During these studies, undergraduate engineering students were involved in the tests, and gained a lot of hands-on research experiences.

  10. Enhanced cavitation and heating of flowing polymer- and lipid-shelled microbubbles and phase-shift nanodroplets during focused ultrasound exposures

    Science.gov (United States)

    Zhang, Siyuan; Cui, Zhiwei; Li, Chong; Zhou, Fanyu; Zong, Yujin; Wang, Supin; Wan, Mingxi

    2017-03-01

    Cavitation and heating are the primary mechanisms of numerous therapeutic applications of ultrasound. Various encapsulated microbubbles (MBs) and phase-shift nanodroplets (NDs) have been used to enhance local cavitation and heating, creating interests in developing ultrasound therapy using these encapsulated MBs and NDs. This work compared the efficiency of flowing polymer- and lipid-shelled MBs and phase-shift NDs in cavitation and heating during focused ultrasound (FUS) exposures. Cavitation activity and temperature were investigated when the solution of polymer- and lipid-shelled MBs and NDs flowed through the vessel in a tissue-mimicking phantom with varying flow velocities when exposed to FUS at various acoustic power levels. The inertial cavitation dose (ICD) for the encapsulated MBs and NDs were higher than those for the saline. Temperature initially increased with increasing flow velocities of the encapsulated MBs, followed by a decrease of the temperature with increasing flow velocities when the velocity was much higher. Meanwhile, ICD showed a trend of increases with increasing flow velocity. For the phase-shift NDs, ICD after the first FUS exposure was lower than those after the second FUS exposure. For the encapsulated MBs, ICD after the first FUS exposure was higher than those after the second FUS exposure. Further studies are necessary to investigate the treatment efficiency of different encapsulated MBs and phase-shift NDs in cavitation and heating.

  11. Using wet microalgae for direct biodiesel production via microwave irradiation.

    Science.gov (United States)

    Cheng, Jun; Yu, Tao; Li, Tao; Zhou, Junhu; Cen, Kefa

    2013-03-01

    To address the large energy consumption of microalgae dewatering and to simplify the conventional two-step method (cellular lipid extraction and lipid transesterification) for biodiesel production, a novel process for the direct conversion of wet microalgae biomass into biodiesel by microwave irradiation is proposed. The influences of conventional thermal heating and microwave irradiation on biodiesel production from wet microalgae biomass were investigated. The effects of using the one-step (simultaneous lipid extraction and transesterification) and two-step methods were also studied. Approximately 77.5% of the wet microalgal cell walls were disrupted under microwave irradiation. The biodiesel production rate and yield from wet microalgae biomass obtained through the one-step process using microwave irradiation were 6-fold and 1.3-fold higher than those from wet microalgae obtained through the two-step process using conventional heating. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... if low oxygen pressure or long reaction times were used. The reaction products derived from the experiment in which quinoline was mostly decomposed were studied with respect to biological degradation. The results showed that these products were highly digestible under activated sludge treatment....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  13. A special type of scald caused by prolonged exposure to slowly heated water.

    Science.gov (United States)

    Pircher, R; Pollak, S; Vogt, S; Epting, T; Kramer, L; Geisenberger, D

    2016-06-01

    When skin is subjected to water temperatures gradually rising from moderate to critical ranges for a prolonged period of time, the resulting scalds will initially present as reddening, followed by blistering and at last by full-thickness burns. On changing from second- to third-degree burn, the blisters stop to become enlarged and solidify due to heat-induced coagulation necrosis. Such gradually intensifying tissue damage results in multiple firm skin blisters together with third-degree burn of the affected area. The initially serous blister fluid assumes a jelly-like consistency as the proteins undergo denaturation. Scalds of this special type may occur in persons taking a bath and becoming incapable to act so that the warm water tap remains turned on or a hairdryer continues to work after having been dropped into the bath water. On the basis of two relevant fatalities (suicidal electrocutions in bathtubs by means of hairdryers), the macroscopic and histological appearance of blisters which only secondarily turned into a full-thickness scald is compared with blisters in genuine second-degree scalds. The blister fluid of the latter ones was also investigated as to their protein composition and hemoglobin concentration. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Integrating multiple stressors across life stages and latitudes: Combined and delayed effects of an egg heat wave and larval pesticide exposure in a damselfly.

    Science.gov (United States)

    Sniegula, Szymon; Janssens, Lizanne; Stoks, Robby

    2017-05-01

    To understand the effects of pollutants in a changing world we need multistressor studies that combine pollutants with other stressors associated with global change such as heat waves. We tested for the delayed and combined impact of a heat wave during the egg stage and subsequent sublethal exposure to the pesticide esfenvalerate during the larval stage on life history and physiology in the larval and adult stage of the damselfly Lestes sponsa. We studied this in a common garden experiment with replicated central- and high latitude populations to explore potential effects of local thermal adaptation and differences in life history shaping the multistressor responses. Exposure of eggs to the heat wave had no effect on larval traits, yet had delayed costs (lower fat and flight muscle mass) in the adult stage thereby crossing two life history transitions. These delayed costs were only present in central-latitude populations potentially indicating their lower heat tolerance. Exposure of larvae to the pesticide reduced larval growth rate and prolonged development time, and across metamorphosis reduced the adult fat content and the flight muscle mass, yet did not affect the adult heat tolerance. The pesticide-induced delayed emergence was only present in the slower growing central-latitude larvae, possibly reflecting stronger selection to keep development fast in the more time-constrained high-latitude populations. We observed no synergistic interactions between the egg heat wave and the larval pesticide exposure. Instead the pesticide-induced reduction in fat content was only present in animals that were not exposed to the egg heat wave. Our results based on laboratory conditions highlight that multistressor studies should integrate across life stages to fully capture cumulative effects of pollutants with other stressors related to global change. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Exposure to extreme heat and precipitation events associated with increased risk of hospitalization for asthma in Maryland, U.S.A.

    Science.gov (United States)

    Soneja, Sutyajeet; Jiang, Chengsheng; Fisher, Jared; Upperman, Crystal Romeo; Mitchell, Clifford; Sapkota, Amir

    2016-04-27

    Several studies have investigated the association between asthma exacerbations and exposures to ambient temperature and precipitation. However, limited data exists regarding how extreme events, projected to grow in frequency, intensity, and duration in the future in response to our changing climate, will impact the risk of hospitalization for asthma. The objective of our study was to quantify the association between frequency of extreme heat and precipitation events and increased risk of hospitalization for asthma in Maryland between 2000 and 2012. We used a time-stratified case-crossover design to examine the association between exposure to extreme heat and precipitation events and risk of hospitalization for asthma (ICD-9 code 493, n = 115,923). Occurrence of extreme heat events in Maryland increased the risk of same day hospitalization for asthma (lag 0) by 3 % (Odds Ratio (OR): 1.03, 95 % Confidence Interval (CI): 1.00, 1.07), with a considerably higher risk observed for extreme heat events that occur during summer months (OR: 1.23, 95 % CI: 1.15, 1.33). Likewise, summertime extreme precipitation events increased the risk of hospitalization for asthma by 11 % in Maryland (OR: 1.11, 95 % CI: 1.06, 1.17). Across age groups, increase in risk for asthma hospitalization from exposure to extreme heat event during the summer months was most pronounced among youth and adults, while those related to extreme precipitation event was highest among ≤4 year olds. Exposure to extreme heat and extreme precipitation events, particularly during summertime, is associated with increased risk of hospitalization for asthma in Maryland. Our results suggest that projected increases in frequency of extreme heat and precipitation event will have significant impact on public health.

  16. Wetting of Water on Graphene

    OpenAIRE

    Bera, Bijoyendra; Shahidzadeh, Noushine; Mishra, Himanshu; Bonn, Daniel

    2016-01-01

    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measurin...

  17. Cognitive consequences of sleep deprivation, shiftwork, and heat exposure for underground miners.

    Science.gov (United States)

    Legault, Glenn; Clement, Alexandra; Kenny, Glen P; Hardcastle, Stephen; Keller, Nancy

    2017-01-01

    Sleep deprivation, abnormal sleep patterns arising from working rotating shifts, and exposure to high ambient temperatures contribute to physical and cognitive dysfunction. We examined the effects of these on 19 (41.5 ± 5.1 years) male underground miners. Data were collected for 28 to 30 consecutive days such that the participants experienced their full rotating shift schedule, including days off. Objective measures of sleep quality (actigraphy), attentional capacity (psychomotor vigilance task), core body temperature (visceral pill), executive function (BRIEF-A) and subjective measures of fatigue (Karolinska and Epworth Sleepiness scales) were obtained over the 28-30 day period. Non-parametric analyses (χ(2), Wilcoxen Signed ranks) were used to determine differences between shift types and days off. Z-tests were used to compare sample data to population norms. These revealed that the participants experienced poor quality of sleep relative to age-matched norms irrespective of the shift being worked or if the participant was on a scheduled day off [30-39 year olds: z = -14.62, p sleep prior to beginning work compared to their days off or night shift; however, no differences in total sleep time between when participants worked day or night shifts were observed [χ(2) (2, n = 18) = 13.44, p sleep deprived. The cognitive consequences of this poor sleep were most pronounced during night shift when their attentional capacity declined rapidly over the course of the night shift. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Effect of gestational and lactational exposure to heat stress on performance in rabbits

    Directory of Open Access Journals (Sweden)

    F. Marco-Jiménez

    2017-03-01

    Full Text Available Reproductive performance is greatly affected by environmental factors such as temperature. Heat stress (HS during pregnancy and lactation can influence not only foetal growth but also postnatal development of kits. The aim of this study was to test the effect of HS during gestation and lactation on postnatal growth till Spanish commercial liveweight. To investigate this, 32 primiparous non lactating rabbit does were exposed to 1 of 2 environmental treatments: high temperature (between 25 and 36°C, HS group; n=16 or thermoneutral conditions (between 14 and 20°C, TN group; n=16. Does were allowed to acclimate 30 d before the artificial insemination. At birth, kits were allocated into 4 groups: HS was only applied during gestation (G group; n=54; HS was applied during gestation and lactation period (GL group; n=85; HS was only applied during lactation period (L group; n=60; and TN was applied during gestation and lactation period (C group; n=77. All litters were kept under each experimental environment until weaning at day 30. Then, litters were moved to TN temperatures until slaughter at day 63. Compared with TN does, the HS does presented lower litter size (9.7 and 11.4; P<0.05, litter weight (503.0 vs. 630.5 g; P<0.05 and kit weight at birth (56.6 vs. 61.4 g; P<0.05, as well as a higher stillborn rate (25.4 vs. 9.9%; P<0.05. The kits from does subjected to HS during gestation (G group had similar postnatal growth compared to offspring from does gestated in TN conditions (C group, whereas kits from does that experienced HS during gestation and lactation (GL group and during their lactation (L group presented decreased postnatal growth. Together, these results demonstrate that kits from does that underwent HS during gestation did not alter postnatal growth until Spanish commercial liveweight, whereas HS during lactation resulted in decreased postnatal growth.

  19. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  20. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Hugo S. Caram; Natalie Foster

    1999-03-30

    The elastic modulus E of wet granular material was found to be of the order of 0.25 MPa, this value does not compare well with the value predicted for a cubic array of spheres under Hertzian contact were the predicted values were in the order of 250 MPa . The strain-stress behavior of a wet granular media was measured using a split Parfitt tensile tester. In all cases the stress increases linearly with distance until the maximum uniaxial tensile stress is reached. The stress then decreases exponentially with distance after this maximum is reached. The linear region indicates that wet solids behave elastically for stresses below the tensile stresses and can store significant elastic energy. The elastic deformation cannot be explained by analyzing the behavior of individual capillary bridges and requires accounting for the deformation of the solids particles. The elastic modulus of the wet granular material remains unexplained. New information was found to support the experimental finding and a first theory to explain the very small elastic modulus is presented. A new model based on the used of the finite element method is being developed.

  1. The Wet Chaparral

    OpenAIRE

    Hope, Audrey Marie

    2017-01-01

    The Wet Chaparral: Poetry at Home (Out There) is an MFA thesis exhibition of new sculptures by Audrey Hope. The thesis paper describes the exhibition, discusses the artist’s personal and artistic motivations, and analyzes writings relevant to the work.

  2. Perceived heat stress and health effects on construction workers.

    Science.gov (United States)

    Dutta, Priya; Rajiva, Ajit; Andhare, Dileep; Azhar, Gulrez Shah; Tiwari, Abhiyant; Sheffield, Perry

    2015-01-01

    Increasing heat waves-particularly in urban areas where construction is most prevalent, highlight a need for heat exposure assessment of construction workers. This study aims to characterize the effects of heat on construction workers from a site in Gandhinagar. This study involved a mixed methods approach consisting of a cross sectional survey with anthropometric measurements (n = 219) and four focus groups with construction workers, as well as environmental measurements of heat stress exposure at a construction site. Survey data was collected in two seasons i.e., summer and winter months, and heat illness and symptoms were compared between the two time periods. Thematic coding of focus group data was used to identify vulnerability factors and coping mechanisms of the workers. Heat stress, recorded using a wet bulb globe temperature monitor, was compared to international safety standards. The survey findings suggest that heat-related symptoms increased in summer; 59% of all reports in summer were positive for symptoms (from Mild to Severe) as compared to 41% in winter. Focus groups revealed four dominant themes: (1) Non-occupational stressors compound work stressors; (2) workers were particularly attuned to the impact of heat on their health; (3) workers were aware of heat-related preventive measures; and (4) few resources were currently available to protect workers from heat stress. Working conditions often exceed international heat stress safety thresholds. Female workers and new employees might be at increased risk of illness or injury. This study suggests significant health impacts on construction workers from heat stress exposure in the workplace, showed that heat stress levels were higher than those prescribed by international standards and highlights the need for revision of work practices, increased protective measures, and possible development of indigenous work safety standards for heat exposure.

  3. THERMAL TRANSFERS IN WET HYPERBARIC ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Tamara STANCIU

    2014-05-01

    Full Text Available The heat losses of human body are greater in underwater environment than in dry, normal atmosphere, due to the great heat capacity of water. Body temperature of divers in immersion was studied taking into account the pressure the divers are subjected to. The theoretic equation that describes the total heat transfer- at both levels: skin and respiratory system- was established, considering conduction, convection and respiratory gas heating and humidification. The body temperature of the divers was measured in a series of dives at different depths of immersion, conducted in the wet simulator of the Diving Center, in Constanta. The experimental results were in good accordance with the temperature predicted by the mathematical model.

  4. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-03-25

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  5. Evaluation of exposure conditions for the water-side corrosion test of a sodium heated steam generator evaporator model employing a duplex tube (2160 hours at critical heat flux - phase III SSGM tests). [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Waszink, R.P.; Hwang, J.Y.; Efferding, L.E.

    1975-12-01

    This report describes the specialized corrosion test water steam loop, test procedures, test conditions, and test results. A complete water chemistry and thermal hydraulic performance history is given and evaluated for the Phase III test program. The movement of the dryout location and the heat flux variations in pre- and post-critical heat flux regions are documented and analyzed. On seven occasions during the course of the test program to date, the operating conditions drifted from the CHF reference Phase III operation in the dryout regime into the DNB regime. The corresponding corrosion mechanism experienced differing exposure conditions on these occasions. CHF sensitivity to this apparent drift behavior is evaluated.

  6. Wetting in Color

    OpenAIRE

    Burgess, Ian Bruce

    2012-01-01

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly...

  7. Wet cooling towers: rule-of-thumb design and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Leeper, Stephen A. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1981-07-01

    A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The theory of heat exchange in wet cooling towers is briefly summarized. The Merkel equation (the fundamental equation of heat transfer in wet cooling towers) is presented and discussed. The cooling tower fill constant (Ka) is defined and values derived. A rule-of-thumb method for the optimized design of cooling towers is presented. The rule-of-thumb design method provides information useful in power plant cycle optimization, including tower dimensions, water consumption rate, exit air temperature, power requirements and construction cost. In addition, a method for simulation of cooling tower performance at various operating conditions is presented. This information is also useful in power plant cycle evaluation. Using the information presented, it will be possible to incorporate wet cooling tower design and simulation into a procedure to evaluate and optimize power plant cycles.

  8. Time-motion analysis as a novel approach for evaluating the impact of environmental heat exposure on labor loss in agriculture workers

    DEFF Research Database (Denmark)

    Ioannou, Leonidas G; Tsoutsoubi, Lydia; Samoutis, George

    2017-01-01

    Introduction: In this study we (i) introduced time-motion analysis for assessing the impact of workplace heat on the work shift time spent doing labor (WTL) of grape-picking workers, (ii) examined whether seasonal environmental differences can influence their WTL, and (iii) investigated whether t....... The studied grape-picking workers experienced increased workplace heat, leading to significant labor loss. Monitoring productivity or the vineyard manager's estimate of each worker's WTL did not completely reflect the true WTL in these grape-picking workers.......Introduction: In this study we (i) introduced time-motion analysis for assessing the impact of workplace heat on the work shift time spent doing labor (WTL) of grape-picking workers, (ii) examined whether seasonal environmental differences can influence their WTL, and (iii) investigated whether...... their WTL can be assessed by monitoring productivity or the vineyard manager's estimate of WTL. Methods: Seven grape-picking workers were assessed during the summer and/or autumn via video throughout four work shifts. Results: Air temperature (26.8 ± 4.8°C), wet bulb globe temperature (WBGT; 25.2 ± 4.1°C...

  9. Wet degradation of keratin proteins: linking amino acid, elemental and isotopic composition.

    Science.gov (United States)

    von Holstein, I C C; Penkman, K E H; Peacock, E E; Collins, M J

    2014-10-15

    Archaeological keratin samples are increasingly the subject of palaeodietary, provenancing and dating studies. Keratin samples from wet archaeological contexts are microbiologically and chemically degraded, causing differential diagenesis of protein structures in hair fibres. The effects of these processes on the analytical parameters of interest are currently unknown. This study examined the impact of degradation of wool fibres on isotopic (δ(13)C, δ(15)N, un-exchangeable δ(2)H and δ(18)O values) composition. It compared two models of archaeological protein degradation in wet burial environments: (1) short term (up to 8 years) experimental burial in three contrasting soil environments; and (2) laboratory wet conditions, in which elevated temperature (80 °C, 110 °C, and 140 °C) and pressure simulated longer exposure. Elemental and amino acid (AA) composition were also measured. In experimentally soil-buried samples, AA, elemental and isotopic composition changes were small, despite extensive macroscopic alteration. Isothermally heated samples showed preferential loss of hydrophilic AAs (Asx, Glx, Ser, Gly) from wool residues, with depletion in (2)H and (18)O at higher temperatures (up to -73‰ change in δ(2)H and -2.6‰ in δ(18)O values). The δ(13)C and δ(15)N values showed little change except in densely pigmented samples at low temperatures only. Samples dyed with madder/alum were better preserved than undyed samples. Diagenesis in experimentally soil-buried wool textiles was consistent with microbiological, non-protein-selective activity, in contrast to highly AA-selective hydrolytic behaviour under laboratory wet conditions. Changes in δ(2)H and δ(18)O values were correlated with degree of AA change, but the δ(13)C and δ(15)N values were not. The results contribute to a baseline for interpreting analytical data from archaeological hair samples preserved by burial in wet environments. Copyright © 2014 John Wiley & Sons, Ltd.

  10. Cardiorespiratory control and cytokine profile in response to heat stress, hypoxia, and lipopolysaccharide (LPS) exposure during early neonatal period.

    Science.gov (United States)

    McDonald, Fiona B; Chandrasekharan, Kumaran; Wilson, Richard J A; Hasan, Shabih U

    2016-02-01

    Sudden infant death syndrome (SIDS) is one of the most common causes of postneonatal infant mortality in the developed world. An insufficient cardiorespiratory response to multiple environmental stressors (such as prone sleeping positioning, overwrapping, and infection), during a critical period of development in a vulnerable infant, may result in SIDS. However, the effect of multiple risk factors on cardiorespiratory responses has rarely been tested experimentally. Therefore, this study aimed to quantify the independent and possible interactive effects of infection, hyperthermia, and hypoxia on cardiorespiratory control in rats during the neonatal period. We hypothesized that lipopolysaccharide (LPS) administration will negatively impact cardiorespiratory responses to increased ambient temperature and hypoxia in neonatal rats. Sprague-Dawley neonatal rat pups were studied at postnatal day 6-8. Rats were examined at an ambient temperature of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 μg/kg) treatments. Cardiorespiratory and thermal responses were recorded and analyzed before, during, and after a hypoxic exposure (10% O2). Serum samples were taken at the end of each experiment to measure cytokine concentrations. LPS significantly increased cytokine concentrations (such as TNFα, IL-1β, MCP-1, and IL-10) compared to control. Our results do not support a three-way interaction between experimental factors on cardiorespiratory control. However, independently, heat stress decreased minute ventilation during normoxia and increased the hypoxic ventilatory response. Furthermore, LPS decreased hypoxia-induced tachycardia. Herein, we provide an extensive serum cytokine profile under various experimental conditions and new evidence that neonatal cardiorespiratory responses are adversely affected by dual interactions of environmental stress factors. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on

  11. Wetting in Color

    Science.gov (United States)

    Burgess, Ian Bruce

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly selective colorimetric indicator for organic liquids. The technology exploits chemically-encoded inverse-opal photonic crystals to control the infiltration of fluids to liquid-specific spatial patterns, projecting minute differences in liquids' wettability to macroscopically distinct, easy-to-visualize structural color patterns. It is shown experimentally and corroborated with theoretical modeling using percolation theory that the high selectivity of wetting, upon-which the sensitivity of the indicator relies, is caused by the highly symmetric structure of our large-area, defect-free SiO2 inverse-opals. The regular structure also produces a bright iridescent color, which disappears when infiltrated with liquid - naturally coupling the optical and fluidic responses. Surface modification protocols are developed, requiring only silanization and selective oxidation, to facilitate the deterministic design of an indicator that differentiates a broad range of liquids. The resulting tunable, built-in horizontal and vertical chemistry gradients allow the wettability threshold to be tailored to specific liquids across a continuous range, and make the readout rely only on countable color differences. As wetting is a generic fluidic phenomenon, Wetting in Color technology could be suitable for applications in authentication or identification of unknown liquids across a broad range of industries. However, the generic nature of the response also ensures chemical non-specificity. It is shown

  12. Heat Related Illnesses

    National Research Council Canada - National Science Library

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

    2006-01-01

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

  13. Wetting dynamics beneath fluid drops impacting on hot surfaces

    Science.gov (United States)

    Harth, Kirsten; van Limbeek, Michiel A. J.; Shirota, Minori; Sun, Chao; Lohse, Detlef

    Fluid droplets encountering a phase transition when they impact a target surface are involved in many applications, e.g., spray cooling or painting / coating, ink-jet and 3D printing, soldering, firefighting using sprinklers. Drop impact on hot plates is an emerging topic, involving a complex interplay of hydrodynamics, heat flux and the occurring phase transition, involving large spatial and temporal gradients. Whether and to what extent droplets touch the surface is of immense importance for the overall heat transfer. High-speed total internal reflection imaging allows us to discriminate wetted and vapor-covered regions of the substrate. We study the transient wetting behaviour of the plate by varying the latent heat of the droplet. The characteristic cooling time of the plate is not solely determined by the plate properties. In addition to current literature, we show that in those cases the wetting pattern is both spatially and temporally inhomogeneous.

  14. Improved bitumen extraction using wet combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, I.; Hagen, D.; McGuire, A. [VAST Power Systems Inc., Elkhart, IN (United States)

    2007-07-01

    This presentation outlined the main concerns regarding the current combustion paradigm for steam assisted gravity drainage (SAGD) bitumen extraction and provided a solution that is more energy efficient with less environmental impact. SAGD operations currently use dry steam injection to deliver heat and reduce the viscosity bitumen, but this results in heat loss, restricted fuel choices, high water use and high emissions. Vast Power Systems Inc. has developed a wet flue gas known as VASTgas{sup TM} for efficient extraction. The downhole fluid has a much higher heat output and much lower emissions of nitrogen oxides, carbon monoxide and carbon dioxide. Other key advantages include net clean water from combustion and electricity as a by-product. This presentation also described the advantages of the VASThermogenerator{sup TM} for SAGD which solves some of the concerns regarding the combustion paradigm of mined bitumen and tailings pond purification. figs.

  15. Roles of DNA repair and membrane integrity in heat resistance of Deinococcus radiodurans.

    Science.gov (United States)

    Bauermeister, Anja; Hahn, Claudia; Rettberg, Petra; Reitz, Günther; Moeller, Ralf

    2012-11-01

    To study the effects of heat shock on Deinococcus radiodurans and the role of DNA repair in high temperature resistance, different strains of D. radiodurans (wild type, recA, irrE, and pprA) were treated with temperatures ranging from 40 to 100 °C under wet and dry conditions. The mutant strains were more sensitive to wet heat of ≥60 °C and dry heat of ≥80 °C than the wild type. Both wild-type and DNA repair-deficient strains were much more resistant to high temperatures when exposed in the dried state as opposed to cells in suspension. Molecular staining techniques with the wild-type strain revealed that cells in the dried state were able to retain membrane integrity after drying and subsequent heat exposure, while heat-exposed cells in suspension showed significant loss of membrane integrity and respiration activity. The results suggest that the repair of DNA damage (e.g., DNA double-strand breaks by RecA and PprA) is essential after treatment with wet heat at temperatures >60 °C and dry heat >80 °C, and the ability of D. radiodurans to stabilize its plasma membrane during dehydration might represent one aspect in the protection of dried cells from heat-induced membrane damage.

  16. Method for wetting a boron alloy to graphite

    Science.gov (United States)

    Storms, E.K.

    1987-08-21

    A method is provided for wetting a graphite substrate and spreading a a boron alloy over the substrate. The wetted substrate may be in the form of a needle for an effective ion emission source. The method may also be used to wet a graphite substrate for subsequent joining with another graphite substrate or other metal, or to form a protective coating over a graphite substrate. A noneutectic alloy of boron is formed with a metal selected from the group consisting of nickel (Ni), palladium (Pd), and platinum (Pt) with excess boron, i.e., and atomic percentage of boron effective to precipitate boron at a wetting temperature of less than the liquid-phase boundary temperature of the alloy. The alloy is applied to the substrate and the graphite substrate is then heated to the wetting temperature and maintained at the wetting temperature for a time effective for the alloy to wet and spread over the substrate. The excess boron is evenly dispersed in the alloy and is readily available to promote the wetting and spreading action of the alloy. 1 fig.

  17. PREFACE: Wetting: introductory note

    Science.gov (United States)

    Herminghaus, S.

    2005-03-01

    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  18. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  19. Energy and exergy analysis of counter flow wet cooling towers

    Directory of Open Access Journals (Sweden)

    Saravanan Mani

    2008-01-01

    Full Text Available Cooling tower is an open system direct contact heat exchanger, where it cools water by both convection and evaporation. In this paper, a mathematical model based on heat and mass transfer principle is developed to find the outlet condition of water and air. The model is solved using iterative method. Energy and exergy analysis infers that inlet air wet bulb temperature is found to be the most important parameter than inlet water temperature and also variation in dead state properties does not affect the performance of wet cooling tower. .

  20. Oligo-microarray analysis and identification of stress-immune response genes from manila clam (Ruditapes philippinarum) exposure to heat and cold stresses.

    Science.gov (United States)

    Menike, Udeni; Lee, Youngdeuk; Oh, Chulhong; Wickramaarachchi, W D N; Premachandra, H K A; Park, Se Chang; Lee, Jehee; De Zoysa, Mahanama

    2014-10-01

    Thermal stress regulates the complex system of gene expression and downstream biochemical and physiological responses in aquatic species. To identify genes involved in heat stress responses in manila clam (Ruditapes philippinarum), microarray analysis was conducted using clam transcriptome generated by pyrosequencing of cDNA library. Manila clams were exposed to heat (30 ± 1 °C) and cold (4 ± 1 °C) stresses and compared with control animals (18 ± 1 °C). Heat stressed animals have changed greater number of transcripts (8,306) than cold stress (7,573). Results of both heat and cold exposure has shown that over 2-fold up-regulated or down regulated (>2-or <2-fold) transcripts were higher at 24 h than at 6 h. It suggests that silent and constitutive express genes can activate at critical stage of thermal stress which could be between 6 and 24 h post stresses. We identified wide range of stress-immune response genes such as transcription factors, heat shock proteins, antioxidant and detoxification enzymes, inflammatory and apoptosis related genes, cell adhesion molecules, cytokines, and IFN regulatory proteins. Histological results revealed that non-specific cellular alterations such as lesions, hypertrophy, and necrosis in stressed gills could be due to decrease of gas exchange rate which may cause hypoxia.

  1. Effects of α-lipoic acid supplementation on sexual difference of growth performance, heat exposure-induced metabolic response and lipid peroxidation of raw meat in broiler chickens.

    Science.gov (United States)

    Hamano, Y

    2014-01-01

    1. The effects of α-lipoic acid administration on sexual differences in growth performance, heat exposure-induced metabolic response and lipid peroxidation of raw meat in broiler chickens were studied. 2. Two-week-old male and female broiler chicks were divided into two groups each, as a 2 × 2 factorial arrangement. Half the birds were fed on a diet supplemented with α-lipoic acid (100 mg/kg) and half on a control diet. All groups were reared to 6 weeks of age at 25°C and, thereafter, exposed to 33°C for 8 h per day for 3 d. 3. Under thermo-neutral conditions, α-lipoic acid decreased feed consumption and body weight gain of male chickens. However, the feed conversion rate and tissue mass of breast muscle and abdominal fat were unchanged. 4. In plasma metabolites, α-lipoic acid increased the molar ratio of non-esterified fatty acids to free glycerol, regardless of sex and heat exposure. A decrease in β-hydroxybutyrate was observed in the α-lipoic acid-fed male chickens. In the heat-exposed chickens, α-lipoic acid lowered the molar ratio of plasma lactate to pyruvate in relation to the enhanced concentrations of plasma pyruvate. However, no sexual difference was observed. 5. The value of thiobarbituric acid reactive substances in breast meat of heat-stressed chickens that was refrigerated for 3 or 7 d was higher in males than in females. An antioxidative effect of α-lipoic acid was observed in the meat of male chickens. 6. The present study suggests that the α-lipoic acid-inducing fatty acid metabolism and antioxidative effect persisted during the heat stress, even though a sexual difference in the responsiveness was seen in broiler chickens.

  2. Analysis of Indirectly Fired Gas Turbine for Wet Biomass Fuels Based on commercial micro gas turbine data

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Qvale, Einar Bjørn

    2002-01-01

    fueled by dry biomass assuming negligible pressure loss in the heat exchanger and the combustion chamber, the IFGT fueled with wet biomass (Wet IFGT) assuming no pressure losses, and finally both the Simple and the Wet IFGT incorporating typical data for pressure losses of commercially available micro...

  3. Time-of-day effects of exposure to solar radiation on thermoregulation during outdoor exercise in the heat.

    Science.gov (United States)

    Otani, Hidenori; Goto, Takayuki; Goto, Heita; Shirato, Minayuki

    2017-01-01

    High solar radiation has been recognised as a contributing factor to exertional heat-related illness in individuals exercising outdoors in the heat. Although solar radiation intensity has been known to have similar time-of-day variation as body temperature, the relationship between fluctuations in solar radiation associated with diurnal change in the angle of sunlight and thermoregulatory responses in individuals exercising outdoors in a hot environment remains largely unknown. The present study therefore investigated the time-of-day effects of variations in solar radiation associated with changing solar elevation angle on thermoregulatory responses during moderate-intensity outdoor exercise in the heat of summer. Eight healthy, high school baseball players, heat-acclimatised male volunteers completed a 3-h outdoor baseball trainings under the clear sky in the heat. The trainings were commenced at 0900 h in AM trial and at 1600 h in PM trial each on a separate day. Solar radiation and solar elevation angle during exercise continued to increase in AM (672-1107 W/m 2 and 44-69°) and decrease in PM (717-0 W/m 2 and 34-0°) and were higher on AM than on PM (both P  0.05). Tympanic temperature measured by an infrared tympanic thermometer and mean skin temperature were higher in AM than PM at 120 and 180 min (P  0.05). The current study demonstrates a greater thermoregulatory strain in the morning than in the afternoon resulting from a higher body temperature and heart rate in relation to an increase in environmental heat stress with rising solar radiation and solar elevation angle during moderate-intensity outdoor exercise in the heat. This response is associated with a lesser net heat loss at the skin and a greater body heat gain from the sun in the morning compared with the afternoon.

  4. Response of heat shock protein genes of the oriental fruit moth under diapause and thermal stress reveals multiple patterns dependent on the nature of stress exposure.

    Science.gov (United States)

    Zhang, Bo; Peng, Yu; Zheng, Jincheng; Liang, Lina; Hoffmann, Ary A; Ma, Chun-Sen

    2016-07-01

    Heat shock protein gene (Hsp) families are thought to be important in thermal adaptation, but their expression patterns under various thermal stresses have still been poorly characterized outside of model systems. We have therefore characterized Hsp genes and their stress responses in the oriental fruit moth (OFM), Grapholita molesta, a widespread global orchard pest, and compared patterns of expression in this species to that of other insects. Genes from four Hsp families showed variable expression levels among tissues and developmental stages. Members of the Hsp40, 70, and 90 families were highly expressed under short exposures to heat and cold. Expression of Hsp40, 70, and Hsc70 family members increased in OFM undergoing diapause, while Hsp90 was downregulated. We found that there was strong sequence conservation of members of large Hsp families (Hsp40, Hsp60, Hsp70, Hsc70) across taxa, but this was not always matched by conservation of expression patterns. When the large Hsps as well as small Hsps from OFM were compared under acute and ramping heat stress, two groups of sHsps expression patterns were apparent, depending on whether expression increased or decreased immediately after stress exposure. These results highlight potential differences in conservation of function as opposed to sequence in this gene family and also point to Hsp genes potentially useful as bioindicators of diapause and thermal stress in OFM.

  5. Daily and seasonal changes in heat exposure and the Hsp70 level of individuals from a field population of Xeropicta derbentina (Krynicki 1836) (Pulmonata, Hygromiidae) in Southern France.

    Science.gov (United States)

    Dieterich, A; Fischbach, U; Ludwig, M; Di Lellis, M A; Troschinski, S; Gärtner, U; Triebskorn, R; Köhler, H-R

    2013-07-01

    The Mediterranean land snail Xeropicta derbentina forms huge populations in Southern France. In order to characterize heat exposure and the induction of the 70-kD heat shock protein (Hsp70) response system during the life cycle of this snail, a selected population from the Vaucluse area, Provence, was investigated encompassing the issues of morphological life cycle parameters (shell size and colouration), the daily courses of heat exposure at different heights above the ground, of shell temperature, and that of the individual Hsp70 levels. The study covered all four seasons of the year 2011. Snails were found to be annual, reaching their final size in August. The shell colouration pattern showed high variation in juveniles (spring) with a strong tendency towards becoming uniformly white at old age in autumn. In all seasons, ambient air temperature decreased with increasing distance from the ground surface during daytime while remaining constantly low in the night. Overall, the Hsp70 level of individuals followed the ambient temperature during diurnal and seasonal variations. Correlation analysis revealed a positive association of individual shell temperature and Hsp70 level for the most part of the life cycle of the snails until late summer, whereas a negative correlation was found for aged animals indicating senescence effects on the capacity of the stress response system.

  6. The effect of fever, febrile illnesses, and heat exposures on the risk of neural tube defects in a Texas-Mexico border population.

    Science.gov (United States)

    Suarez, Lucina; Felkner, Marilyn; Hendricks, Kate

    2004-10-01

    Hyperthermia produces neural tube defects (NTDs) in a variety of animal species. Elevated maternal body temperatures may also place the developing human embryo at risk. We examined the relation between maternal hyperthermia and the development of NTDs in a high-risk Mexican-American population. Case-women were Mexican-American women with NTD-affected pregnancies who resided and delivered in any of the 14 Texas counties bordering Mexico, during 1995-2000. Control-women were randomly selected from study area residents delivering normal live births, frequency-matched to cases by hospital and year. Information on maternal fevers, febrile illnesses, exposures to heat generated from external sources, and hyperthermia-inducing activities was gathered through in-person interviews, conducted about six weeks postpartum. The risk effect (OR) associated with maternal fever in the first trimester, compared to no fever, was 2.9 (95% CI, 1.5-5.7). Women taking fever-reducing medications showed a lower risk effect (OR, 2.4; 95% CI, 1.0-5.6) than those who did not (OR, 3.8; 95% CI, 1.4-10.9). First-trimester maternal exposures to heat devices such as hot tubs, saunas, or electric blankets were associated with an OR of 3.6 (95% CI, 1.1-15.9). Small insignificant effects were observed for activities such as cooking in a hot kitchen (OR, 1.6; 95% CI, 1.0-2.6) and working or exercising in the sun (OR, 1.4; 95% CI, 0.9-2.2). Maternal hyperthermia increases the risk for NTD-affected offspring. Women intending to become pregnant should avoid intense heat exposures, carefully monitor and manage their febrile illnesses, and routinely consume folic acid supplements. (c) 2004 Wiley-Liss, Inc.

  7. Subcritical water extraction of lipids from wet algal biomass

    Science.gov (United States)

    Deng, Shuguang; Reddy, Harvind K.; Schaub, Tanner; Holguin, Francisco Omar

    2016-05-03

    Methods of lipid extraction from biomass, in particular wet algae, through conventionally heated subcritical water, and microwave-assisted subcritical water. In one embodiment, fatty acid methyl esters from solids in a polar phase are further extracted to increase biofuel production.

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

    Directory of Open Access Journals (Sweden)

    Shin Koyama

    2016-08-01

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

  9. Nanoscale Structural and Mechanical Analysis of Bacillus anthracis Spores Inactivated with Rapid Dry Heating

    Science.gov (United States)

    Felker, Daniel L.; Burggraf, Larry W.

    2014-01-01

    Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating. PMID:24375142

  10. Using a historic drought and high-heat event to validate thermal exposure predictions for ground-dwelling birds.

    Science.gov (United States)

    Carroll, James M; Davis, Craig A; Elmore, R Dwayne; Fuhlendorf, Samuel D

    2017-08-01

    Deviations from typical environmental conditions can provide insight into how organisms may respond to future weather extremes predicted by climate modeling. During an episodic and multimonth heat wave event (i.e., ambient temperature up to 43.4°C), we studied the thermal ecology of a ground-dwelling bird species in Western Oklahoma, USA. Specifically, we measured black bulb temperature (Tbb) and vegetation parameters at northern bobwhite (Colinus virginianus; hereafter bobwhite) adult and brood locations as well as at stratified random points in the study area. On the hottest days (i.e., ≥39°C), adults and broods obtained thermal refuge using tall woody cover that remained on average up to 16.51°C cooler than random sites on the landscape which reached >57°C. We also found that refuge sites used by bobwhites moderated thermal conditions by more than twofold compared to stratified random sites on the landscape but that Tbb commonly exceeded thermal stress thresholds for bobwhites (39°C) for several hours of the day within thermal refuges. The serendipitous high heat conditions captured in our study represent extreme heat for our study region as well as thermal stress for our study species, and subsequently allowed us to assess ground-dwelling bird responses to temperatures that are predicted to become more common in the future. Our findings confirm the critical importance of tall woody cover for moderating temperatures and functioning as important islands of thermal refuge for ground-dwelling birds, especially during extreme heat. However, the potential for extreme heat loads within thermal refuges that we observed (albeit much less extreme than the landscape) indicates that the functionality of tall woody cover to mitigate heat extremes may be increasingly limited in the future, thereby reinforcing predictions that climate change represents a clear and present danger for these species.

  11. Forced wetting and hydrodynamic assist

    Science.gov (United States)

    Blake, Terence D.; Fernandez-Toledano, Juan-Carlos; Doyen, Guillaume; De Coninck, Joël

    2015-11-01

    Wetting is a prerequisite for coating a uniform layer of liquid onto a solid. Wetting failure and air entrainment set the ultimate limit to coating speed. It is well known in the coating art that this limit can be postponed by manipulating the coating flow to generate what has been termed "hydrodynamic assist," but the underlying mechanism is unclear. Experiments have shown that the conditions that postpone air entrainment also reduce the apparent dynamic contact angle, suggesting a direct link, but how the flow might affect the contact angle remains to be established. Here, we use molecular dynamics to compare the outcome of steady forced wetting with previous results for the spontaneous spreading of liquid drops and apply the molecular-kinetic theory of dynamic wetting to rationalize our findings and place them on a quantitative footing. The forced wetting simulations reveal significant slip at the solid-liquid interface and details of the flow immediately adjacent to the moving contact line. Our results confirm that the local, microscopic contact angle is dependent not simply only on the velocity of wetting but also on the nature of the flow that drives it. In particular, they support an earlier suggestion that during forced wetting, an intense shear stress in the vicinity of the contact line can assist surface tension forces in promoting dynamic wetting, thus reducing the velocity-dependence of the contact angle. Hydrodynamic assist then appears as a natural consequence of wetting that emerges when the contact line is driven by a strong and highly confined flow. Our theoretical approach also provides a self-consistent model of molecular slip at the solid-liquid interface that enables its magnitude to be estimated from dynamic contact angle measurements. In addition, the model predicts how hydrodynamic assist and slip may be influenced by liquid viscosity and solid-liquid interactions.

  12. Heat exposure of corals: investigating the "other" diffusive boundary layer

    DEFF Research Database (Denmark)

    Jimenez, Isabel M.; Kühl, Michael; Larkum, Anthony W. D.

    of corals under bleaching conditions, we used temperature microsensors to investigate the thermal boundary layer (TBL) of a branching and a hemispherical coral species (Stylophora pistillata and Porites lobata). The TBL thickness for both species was 2 mm at quasi stagnant flow (0.3 cm/s), and declined...... exponentially at increasing flow. Dimensionless analysis of heat transfer (Nusselt-Reynolds number plots) resulted in a heat exponent of approx. 0.5, indicative of a laminar boundary layer and consistent with predictions from engineering theory for simple geometrical objects. However, additional measurements...

  13. The effect of damp heat-illumination exposure on CIGS solar cells: A combined XRD and electrical characterization study

    NARCIS (Netherlands)

    Theelen, M.; Hendrikx, R.; Barreau, N.; Steijvers, H.; Böttger, A.

    2016-01-01

    Unencapsulated CIGS solar cells were simultaneously exposed to damp heat and illumination. In-situ monitoring of their electrical parameters demonstrated a rapid decrease of the efficiency, mainly driven by changes in the series and shunt resistances. The non-degraded and degraded solar cells were

  14. Integrating local urban climate modelling and mobile sensor data for personal exposure assessments in the context of urban heat island effect

    Science.gov (United States)

    Ueberham, Maximilian; Hertel, Daniel; Schlink, Uwe

    2017-04-01

    Deeper knowledge about urban climate conditions is getting more important in the context of climate change, urban population growth, urban compaction and continued surface sealing. Especially the urban heat island effect (UHI) is one of the most significant human induced alterations of Earth's surface climate. According to this the appearance frequency of heat waves in cities will increase with deep impacts on personal thermal comfort, human health and local residential quality of citizens. UHI can be very heterogenic within a city and research needs to focus more on the neighborhood scale perspective to get further insights about the heat burden of individuals. However, up to now, few is known about local thermal environmental variances and personal exposure loads. To monitor these processes and the impact on individuals, improved monitoring approaches are crucial, complementing data recorded at conventional fixed stations. Therefore we emphasize the importance of micro-meteorological modelling and mobile measurements to shed new light on the nexus of urban human-climate interactions. Contributing to this research we jointly present the approaches of our two PhD-projects. Firstly we illustrate on the basis of an example site, how local thermal conditions in an urban district can be simulated and predicted by a micro-meteorological model. Secondly we highlight the potentials of personal exposure measurements based on an evaluation of mobile micro-sensing devices (MSDs) and analyze and explain differences between model predictions and mobile records. For the examination of local thermal conditions we calculated ENVI-met simulations within the "Bayerischer Bahnhof" quarter in Leipzig (Saxony, Germany; 51°20', 12°22'). To accomplish the maximum temperature contrasts within the diverse built-up structures we chose a hot summer day (25 Aug 2016) under autochthonous weather conditions. From these simulations we analyzed a UHI effect between the model core (urban area

  15. Exposure to polycyclic aromatic hydrocarbons and volatile organic compounds among recently pregnant rural Guatemalan women cooking and heating with solid fuels.

    Science.gov (United States)

    Weinstein, John R; Asteria-Peñaloza, Renée; Diaz-Artiga, Anaité; Davila, Gilberto; Hammond, S Katharine; Ryde, Ian T; Meyer, Joel N; Benowitz, Neal; Thompson, Lisa M

    2017-06-01

    Household air pollution is a major contributor to death and disability worldwide. Over 95% of rural Guatemalan households use woodstoves for cooking or heating. Woodsmoke contains carcinogenic or fetotoxic polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Increased PAHs and VOCs have been shown to increase levels of oxidative stress. We examined PAH and VOC exposures among recently pregnant rural Guatemalan women exposed to woodsmoke and compared exposures to levels seen occupationally or among smokers. Urine was collected from 23 women who were 3 months post-partum three times over 72h: morning (fasting), after lunch, and following dinner or use of wood-fired traditional sauna baths (samples=68). Creatinine-adjusted urinary concentrations of metabolites of four PAHs and eight VOCs were analyzed by liquid chromatography-mass spectrometry. Creatinine-adjusted urinary biomarkers of oxidative stress, 8-isoprostane and 8-OHdG, were analyzed using enzyme-linked immunosorbent assays (ELISA). Long-term (pregnancy through 3 months prenatal) exposure to particulate matter and airborne PAHs were measured. Women using wood-fueled chimney stoves are exposed to high levels of particulate matter (median 48h PM2.5 105.7μg/m3; inter-quartile range (IQR): 77.6-130.4). Urinary PAH and VOC metabolites were significantly associated with woodsmoke exposures: 2-naphthol (median (IQR) in ng/mg creatinine: 295.9 (74.4-430.9) after sauna versus 23.9 (17.1-49.5) fasting; and acrolein: 571.7 (429.3-1040.7) after sauna versus 268.0 (178.3-398.6) fasting. Urinary PAH (total PAH: ρ=0.89, p0.85) or PAH and VOC biomarkers (ρ=-0.20 to 0.38, p>0.07). Urinary metabolite concentrations were significantly greater than those of heavy smokers (mean cigarettes/day=18) across all PAHs. In 15 (65%) women, maximum 1-hydroxypyrene concentrations exceeded the occupational exposure limit of coke-oven workers. The high concentrations of urinary PAH and VOC metabolites among

  16. First report on heat shock protein expression in red spider mites (Oligonychus coffeae) in response to pesticide exposure

    OpenAIRE

    AK Prasad; G Handique; Barua, A.; Roy, S.

    2016-01-01

    ISJ 13: 350-354, 2016 ISSN 1824-307X Red spider mites (RSM) is one of the major pest of tea and reported from all tea producing regions around the world. Chemical acaricides are the primary control method against this pest which induced biochemical changes in the RSM. In this study early expression of heat shock proteins have been observed in RSM exposed to commonly used acaricides viz., ethion, dicofol and fenpropathrin. In case of pesticide exposed RSM, hsp90 showed more pr...

  17. The influence of post-exposure heating on the stability of MCP-N (LiF:Mg,Cu,P) TL detectors.

    Science.gov (United States)

    Budzanowski, M

    2002-01-01

    Post-exposure annealing of highly sensitive LiF:Mg,Cu,P (MCP-N) detectors, at 100 degrees C over 10 or 20 min prior to readout, is usually recommended for routine dosimetry. The purpose of this anneal is to eliminate low-temperature peaks, especially peak 3, which fades at room temperature in about 3 months. However, as this annealing procedure does not entirely eliminate peak 3, 10% of its thermoluminescent (TL) signal still being readable, a fading correction must be applied. The aim of this work was to optimise the conditions of post-exposure treatment, i.e. its temperature and duration, in order to facilitate the use of MCP-N detectors in routine dosimetry. MCP-N detectors were annealed in standard conditions, i.e. at 240 degrees C over 10 min and exposed to a dose of 5 mGy (137Cs). For post-exposure annealing, six different temperatures between 100 degrees C and 150 degrees C and two time periods (10 and 20 min) were tested. TL glow curves were deconvoluted with the GCA code. A post-exposure anneal at 120 degrees C over 10 min was found to be optimal. Heating at this temperature eliminates 100% of the TL signal of peak 3, while maintaining the area and maximum intensity of the main peak 4 unchanged. In this case, no fading correction needs to be applied. Annealing at higher temperatures, up to 150 degrees C, results in a loss of peak 4 signal, and is therefore not recommended.

  18. Wetting of Water on Graphene

    KAUST Repository

    Bera, Bijoyendra

    2016-11-28

    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measuring the mass of water vapor adsorbing to graphene flakes of different thickness at different relative humidities. Our experiments unambiguously show that the thinnest of graphene flakes do not adsorb water, from which it follows that the contact angle of water on these flakes is ~180o. Thicker flakes of graphene nanopowder, on the other hand, do adsorb water. A calculation of the van der Waals (vdW) interactions that dominate the adsorption in this system confirms that the adhesive interactions between a single atomic layer of graphene and water are so weak that graphene is superhydrophobic. The observations are confirmed in an independent experiment on graphene-coated water droplets that shows that it is impossible to make liquid \\'marbles\\' with molecularly thin graphene.

  19. Surface structure determines dynamic wetting

    Science.gov (United States)

    Shiomi, Junichiro; Wang, Jiayu; Do-Quang, Minh; Cannon, James; Yue, Feng; Suzuki, Yuji; Amberg, Gustav

    2014-11-01

    Dynamic wetting, the spontaneous spreading process after droplet contacts a solid surface, is important in various engineering processes, such as in printing, coating, and lubrication. In the recent years, experiments and numerical simulations have greatly progressed the understanding in the dynamic wetting particularly on ``flat'' substrates. To gain further insight into the governing physics of the dynamic wetting, we perform droplet-wetting experiments on microstructured surfaces, just a few micrometers in size, with complementary numerical simulations, and investigate the dependence of the spreading rate on the microstructure geometries and fluid properties. We reveal that the influence of microstructures can be quantified in terms of a line friction coefficient for the energy dissipation rate at the contact line, and that this can be described in a simple formula in terms of the geometrical parameters of the roughness and the line-friction coefficient of the planar surface. The systematic study is also of practical importance since structures and roughness are omnipresent and their influence on spreading rate would give us additional degrees of freedom to control the dynamic wetting. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W., J.C., and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A.).

  20. Composite heat damage spectroscopic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J.; Muhs, J.D.; Wachter, E.A.; Ziegler, R.E. (Oak Ridge National Lab., TN (USA)); Powell, G.L.; Smyrl, N.R. (Oak Ridge Y-12 Plant, TN (USA)); Philpot, H.E. (Oak Ridge Gaseous Diffusion Plant, TN (USA))

    1990-09-01

    The Oak Ridge National Laboratory/Applied Technology Division (ORNL/ATD) has successfully demonstrated the unique applicability of two spectroscopic techniques that possess the capability of detecting heat damage in IM6/3501-6 laminates and correlation of this damage with the residual mechanical-strength properties. The results on the diffuse reflectance infrared fourier transform (DRIFT) and laser-pumped fluorescence (LPF) spectroscopic techniques, which are capable of rapid, in-service, non-destructive detection and quantitation of heat damage in IM6/3501-6 laminates, is presented. Both of these techniques have been shown to be quite effective at probing the elusive and complex molecular changes that take place in IM6/3501-6 laminates subjected to varying degrees of thermal degradation. Using LPF or DRIFT techniques, it has been shown that laminates having different thermal histories can be readily differentiated from one another due to their characteristic fingerprint'' spectral features. The effects of short-term, elevated temperature heating on the room- temperature compressive interlaminar-shear, and flexural strengths and room-temperature shore-D hardness properties of dry'' and wet'' preconditioned IM6/3501-6 laminates are discussed. Additionally, the geometrical changes and percent-weight-loss measurements of IM6/3501-6 laminates that accompany heat damage are also examined. It was found that below a certain temperature/time exposure threshold, these laminates visually and microscopically appeared to be undamaged but, in fact, may have lost a significant percentage of their original strength. In addition, laminates that were exposed above the temperature/time exposure threshold suffered dramatic geometrical changes and large amounts of weight loss. 32 refs., 39 figs., 10 tabs.

  1. In situ transesterification of highly wet microalgae using hydrochloric acid.

    Science.gov (United States)

    Kim, Bora; Im, Hanjin; Lee, Jae W

    2015-06-01

    This study addresses in situ transesterification of highly wet microalgae with hydrochloric acid (HCl) as a catalyst. In situ transesterification was performed by heating the mixture of wet algal cells, HCl, methanol, and solvent in one pot, resulting in the fatty acid methyl ester (FAME) yield over 90% at 95°C. The effects of reaction variables of temperature, amounts of catalyst, reactant, and solvent, and type of solvents on the yield were investigated. Compared with the catalytic effect of H2SO4, in situ transesterification using HCl has benefits of being less affected by moisture levels that are as high as or above 80%, and requiring less amounts of catalyst and solvent. For an equimolar amount of catalyst, HCl showed 15wt.% higher FAME yield than H2SO4. This in situ transesterification using HCl as a catalyst would help to realize a feasible way to produce biodiesel from wet microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Wetting and Spreading of Molten Volcanic Ash in Jet Engines.

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Wadsworth, Fabian B; Hess, Kai-Uwe; Dingwell, Donald B

    2017-04-20

    A major hazard to jet engines posed by volcanic ash is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Here, using the sessile drop method, we study the evolution of the wettability and spreading of volcanic ash. We employ rapid temperature changes up to 1040-1450 °C, to replicate the heating conditions experienced by volcanic ash entering an operating jet engine. In this scenario, samples densify as particles coalesce under surface tension until they form a large system-sized droplet (containing remnant gas bubbles and crystals), which subsequently spreads on the surface. The data exhibit a transition from a heterogeneous to a homogeneous wetting regime above 1315 °C as crystals in the drops are dissolved in the melt. We infer that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten volcanic ash droplets.

  3. Correlation between dynamic wetting behavior and chemical components of thermally modified wood

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wang; Zhu, Yuan; Cao, Jinzhen, E-mail: caoj@bjfu.edu.cn; Sun, Wenjing

    2015-01-01

    Highlights: • We studied the dynamic wetting behavior of thermally modified wood by wetting models. • We found lower wetting speed of water droplets on thermally modified wood surface. • Dynamic wetting behavior and surface chemical components show a strong correlation. - Abstract: In order to investigate the dynamic wetting behavior of thermally modified wood, Cathay poplar (Populus cathayana Rehd.) and Scots pine (Pinus sylvestris L.) samples were thermally modified in an oven at 160, 180, 200, 220 or 240 °C for 4 h in this study. The dynamic contact angles and droplet volumes of water droplets on modified and unmodified wood surfaces were measured by sessile drop method, and their changing rates (expression index: K value and wetting slope) calculated by wetting models were illustrated for mapping the dynamic wetting process. The surface chemical components were also measured by X-ray photoelectron spectroscopy analysis (XPS), thus the relationship between dynamic wetting behavior and chemical components of thermally modified wood were determined. The results indicated that thermal modification was capable of decreasing the dynamic wettability of wood, expressed in lowing spread and penetration speed of water droplets on wood surfaces. This change was more obvious with the increased heating temperature. The K values varied linearly with the chemical components parameter (mass loss, O/C ratio, and C{sub 1}/C{sub 2} ratio), indicating a strong correlation between dynamic wetting behavior and chemical components of thermally modified wood.

  4. Creep strength and microstructural evolution of 9-12% Cr heat resistant steels during creep exposure at 600 C and 650 C

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Martin, Francisca [Graz Univ. of Technology (Austria). Inst. for Materials Science and Welding; Panait, Clara Gabriela [MINES ParisTech, UMR CNRS, Evry (France). Centre des Materiaux; V et M France CEV, Aulnoye-Aymeries (France); Bendick, Walter [Salzgitter Mannesmann Forschung GmbH (SZMF), Duisburg (DE)] (and others)

    2010-07-01

    9-12% Cr heat resistant steels are used for applications at high temperatures and pressures in steam power plants. 12% Cr steels show higher creep strength and higher corrosion resistance compared to 9% Cr steels for short term creep exposure. However, the higher creep strength of 12 %Cr steels drops increasingly after 10,000-20,000 h of creep. This is probably due to a microstructural instability such as the precipitation of new phases (e.g. Laves phases and Z-phases), the growth of the precipitates and the recovery of the matrix. 9% Cr and 12% Cr tempered martensitic steels that have been creep tested for times up to 50,000 h at 600 C and 650 C were investigated using Transmission Electron Microscopy (TEM) on extractive replicas and thin foils together with Backscatter Scanning Electron Microscopy (BSE-SEM) to better understand the different creep behaviour of the two different steels. A significant precipitation of Laves phase and low amounts of Z-phase was observed in the 9% Cr steels after long-term creep exposure. The size distribution of Laves phases was measured by image analysis of SEM-BSE images. In the 12% Cr steel two new phases were identified, Laves phase and Z-phase after almost 30,000 h of creep test. The quantification of the different precipitated phases was studied. (orig.)

  5. Aroma recovery from roasted coffee by wet grinding.

    Science.gov (United States)

    Baggenstoss, J; Thomann, D; Perren, R; Escher, F

    2010-01-01

    Aroma recovery as determined by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was compared in coffees resulting from conventional grinding processes, and from wet grinding with cold and hot water. Freshly roasted coffee as well as old, completely degassed coffee was ground in order to estimate the relationship of internal carbon dioxide pressure in freshly roasted coffee with the aroma loss during grinding. The release of volatile aroma substances during grinding was found to be related to the internal carbon dioxide pressure, and wet grinding with cold water was shown to minimize losses of aroma compounds by trapping them in water. Due to the high solubility of roasted coffee in water, the use of wet-grinding equipment is limited to processes where grinding is followed by an extraction step. Combining grinding and extraction by the use of hot water for wet grinding resulted in considerable losses of aroma compounds because of the prolonged heat impact. Therefore, a more promising two-step process involving cold wet grinding and subsequent hot extraction in a closed system was introduced. The yield of aroma compounds in the resulting coffee was substantially higher compared to conventionally ground coffee. © 2010 Institute of Food Technologists®

  6. The Impact of Heat Exposure and Sleep Restriction on Firefighters' Work Performance and Physiology during Simulated Wildfire Suppression.

    Science.gov (United States)

    Vincent, Grace E; Aisbett, Brad; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Ferguson, Sally A

    2017-02-12

    This study was designed to examine the effects of ambient heat on firefighters' physical task performance, and physiological and perceptual responses when sleep restricted during simulated wildfire conditions. Thirty firefighters were randomly allocated to the sleep restricted (n = 17, SR; 19 °C, 4-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Firefighters performed two days of simulated, intermittent, self-paced work circuits comprising six firefighting tasks. Heart rate, and core temperature were measured continuously. After each task, firefighters reported their rating of perceived exertion and thermal sensation. Effort sensation was also reported after each work circuit. Fluids were consumed ad libitum. Urine volume and urine specific gravity were analysed. Sleep was monitored using polysomnography. There were no differences between the SR and HOT + SR groups in firefighters' physiological responses, hydration status, ratings of perceived exertion, motivation, and four of the six firefighting tasks (charged hose advance, rake, hose rolling, static hose hold). Black out hose and lateral repositioning were adversely affected in the HOT + SR group. Working in hot conditions did not appear to consistently impair firefighters work performance, physiology, and perceptual responses. Future research should determine whether such findings remain true when individual tasks are performed over longer durations.

  7. The Impact of Heat Exposure and Sleep Restriction on Firefighters’ Work Performance and Physiology during Simulated Wildfire Suppression

    Directory of Open Access Journals (Sweden)

    Grace E. Vincent

    2017-02-01

    Full Text Available This study was designed to examine the effects of ambient heat on firefighters’ physical task performance, and physiological and perceptual responses when sleep restricted during simulated wildfire conditions. Thirty firefighters were randomly allocated to the sleep restricted (n = 17, SR; 19 °C, 4-h sleep opportunity or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity condition. Firefighters performed two days of simulated, intermittent, self-paced work circuits comprising six firefighting tasks. Heart rate, and core temperature were measured continuously. After each task, firefighters reported their rating of perceived exertion and thermal sensation. Effort sensation was also reported after each work circuit. Fluids were consumed ad libitum. Urine volume and urine specific gravity were analysed. Sleep was monitored using polysomnography. There were no differences between the SR and HOT + SR groups in firefighters’ physiological responses, hydration status, ratings of perceived exertion, motivation, and four of the six firefighting tasks (charged hose advance, rake, hose rolling, static hose hold. Black out hose and lateral repositioning were adversely affected in the HOT + SR group. Working in hot conditions did not appear to consistently impair firefighters work performance, physiology, and perceptual responses. Future research should determine whether such findings remain true when individual tasks are performed over longer durations.

  8. Wetting and spreading behavior of Ti-based brazing filler on Ti64 substrate

    Science.gov (United States)

    Komolafe, Bolarinwa; Mostafa, Ahmad

    2017-06-01

    In this work, wetting behavior of Ti-20Zr-20Cu-20Ni brazing filler on Ti-6Al-4V substrate was studied using sessile drop technique. Effects of the substrate surface roughness, R a of ~0.40 and 0.08 µm, and heating scheme on wetting and spreading of the filler metal were evaluated. The wetting mechanism was investigated by the combination of cooling technique, thermal, compositional, and microstructural analysis. This was performed using a heat-flux DSC and an SEM equipped with EDS. The degree of wetting was evaluated by measuring the apparent dynamic contact angle between the filler drop and substrate surface and by calculating the drop spread ratio. The surface roughness of the substrate was found to have little or no effect on the final apparent contact angle. The wetting behavior of this system showed a reactive nature, because it involves dissolution of the substrate and formation of interfacial layers. Three heating schemes were used in the current study. While the high heating rate of 6.8 °C s-1 was found to limit the metallurgical reaction between the substrate and the brazing filler, in the low heating rate scheme of 1.7 °C s-1, more intense metallurgical reaction occurred between the brazing filler and the substrate. The high heating rate with soaking scheme is recommended for brazing, because it entails extensive spreading and limited metallurgical reaction between the brazing filler and the substrate.

  9. Fatal Exertional Heat Stroke and American Football Players: The Need for Regional Heat-Safety Guidelines.

    Science.gov (United States)

    Grundstein, Andrew J; Hosokawa, Yuri; Casa, Douglas J

    2018-01-01

      Weather-based activity modification in athletics is an important way to minimize heat illnesses. However, many commonly used heat-safety guidelines include a uniform set of heat-stress thresholds that do not account for geographic differences in acclimatization.   To determine if heat-related fatalities among American football players occurred on days with unusually stressful weather conditions based on the local climate and to assess the need for regional heat-safety guidelines.   Cross-sectional study.   Data from incidents of fatal exertional heat stroke (EHS) in American football players were obtained from the National Center for Catastrophic Sport Injury Research and the Korey Stringer Institute.   Sixty-one American football players at all levels of competition with fatal EHSs from 1980 to 2014.   We used the wet bulb globe temperature (WBGT) and a z-score WBGT standardized to local climate conditions from 1991 to 2010 to assess the absolute and relative magnitudes of heat stress, respectively.   We observed a poleward decrease in exposure WBGTs during fatal EHSs. In milder climates, 80% of cases occurred at above-average WBGTs, and 50% occurred at WBGTs greater than 1 standard deviation from the long-term mean; however, in hotter climates, half of the cases occurred at near average or below average WBGTs.   The combination of lower exposure WBGTs and frequent extreme climatic values in milder climates during fatal EHSs indicates the need for regional activity-modification guidelines with lower, climatically appropriate weather-based thresholds. Established activity-modification guidelines, such as those from the American College of Sports Medicine, work well in the hotter climates, such as the southern United States, where hot and humid weather conditions are common.

  10. Different regimes of dynamic wetting

    Science.gov (United States)

    Gustav, Amberg; Wang, Jiayu; Do-Quang, Minh; Shiomi, Junichiro; Physiochemical fluid mechanics Team; Maruyama-Chiashi Laboratory Team

    2014-11-01

    Dynamic wetting, as observed when a droplet contacts a dry solid surface, is important in various engineering processes, such as printing, coating, and lubrication. Our overall aim is to investigate if and how the detailed properties of the solid surface influence the dynamics of wetting. Here we discuss how surface roughness influences the initial dynamic spreading of a partially wetting droplet by studying the spreading on a solid substrate patterned with microstructures just a few micrometers in size. This is complemented by matching numerical simulations. We present a parameter map, based on the properties of the liquid and the solid surface, which identifies qualitatively different spreading regimes, where the spreading speed is limited by either the liquid viscosity, the surface properties, or the liquid inertia. The peculiarities of the different spreading regimes are studied by detailed numerical simulations, in conjuction with experiments. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W. and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A).

  11. Evaluation of mobile micro-sensing devices for GPS-based personal exposure monitoring of heat and particulate matter - a matter of context

    Science.gov (United States)

    Ueberham, Maximilian; Schlink, Uwe; Weiland, Ulrike

    2017-04-01

    The application of mobile micro-sensing devices (MSDs) for human health and personal exposure monitoring (PEM) is an emerging topic of interest in urban air quality research. In the context of climate change, urban population growth and related anthropogenic activities, an increase is expected for the intensity of citizens' exposure to heat and particulate matter (PM). Therefore more focus on the small-scale perspective of spatio-temporal distribution of air quality parameters is important to complement fixed-monitoring site data. Mobile sensors for PEM are useful for both, the investigation of the local distribution of air quality and the personal exposure profiles of individuals moving within their activity spaces. An evaluation of MSDs' accuracy is crucial, before their sophisticated application in measurement campaigns. To detect variations of exposure at small scales, it is even more important to consider the accuracy of Global Positioning System (GPS) devices within different urban structure types (USTs). We present an assessment of the performance of GPS-based MSDs under indoor laboratory conditions and outdoor testing within different USTs. The aim was to evaluate the accuracy of several GPS devices and MSDs for heat and PM 2.5 in relation to reliable standard sensing devices as part of a PhD-project. The performance parameters are summary measures (mean value, standard deviation), correlation (Pearson r), difference measures (mean bias error, mean absolute error, index of agreement) and Bland-Altman plots. The MSDs have been tested in a climate chamber under constant temperature and relative humidity. For temperature MSDs reaction time was tested because of its relevance to detect temperature variations during mobile measurements. For interpretation of the results we considered the MSDs design and technology (e.g. passive vs. active ventilation). GPS-devices have been tested within low/high dense urban residential areas and low/high dense urban green areas

  12. An Evaluation of Portable Wet Bulb Globe Temperature Monitor Accuracy.

    Science.gov (United States)

    Cooper, Earl; Grundstein, Andrew; Rosen, Adam; Miles, Jessica; Ko, Jupil; Curry, Patrick

    2017-12-01

    Wet bulb globe temperature (WBGT) is the gold standard for assessing environmental heat stress during physical activity. Many manufacturers of commercially available instruments fail to report WBGT accuracy.   To determine the accuracy of several commercially available WBGT monitors compared with a standardized reference device.   Observational study.   Field test.   Six commercially available WBGT devices.   Data were recorded for 3 sessions (1 in the morning and 2 in the afternoon) at 2-minute intervals for at least 2 hours. Mean absolute error (MAE), root mean square error (RMSE), mean bias error (MBE), and the Pearson correlation coefficient ( r) were calculated to determine instrument performance compared with the reference unit.   The QUESTemp° 34 (MAE = 0.24°C, RMSE = 0.44°C, MBE = -0.64%) and Extech HT30 Heat Stress Wet Bulb Globe Temperature Meter (Extech; MAE = 0.61°C, RMSE = 0.79°C, MBE = 0.44%) demonstrated the least error in relation to the reference standard, whereas the General WBGT8778 Heat Index Checker (General; MAE = 1.18°C, RMSE = 1.34°C, MBE = 4.25%) performed the poorest. The QUESTemp° 34 and Kestrel 4400 Heat Stress Tracker units provided conservative measurements that slightly overestimated the WBGT provided by the reference unit. Finally, instruments using the psychrometric wet bulb temperature (General, REED Heat Index WBGT Meter, and WBGT-103 Heat Stroke Checker) tended to underestimate the WBGT, and the resulting values more frequently fell into WBGT-based activity categories with fewer restrictions as defined by the American College of Sports Medicine.   The QUESTemp° 34, followed by the Extech, had the smallest error compared with the reference unit. Moreover, the QUESTemp° 34, Extech, and Kestrel units appeared to offer conservative yet accurate assessments of the WBGT, potentially minimizing the risk of allowing physical activity to continue in stressful heat environments. Instruments using the

  13. Characterize and Gene Expression of Heat Shock Protein 90 in Marine Crab Charybdis japonica following Bisphenol A and 4-Nonylphenol Exposures

    Science.gov (United States)

    Park, Kiyun

    2014-01-01

    Objectives Heat shock protein 90 (HSP90) is a highly conserved molecular chaperone important in the maturation of a broad spectrum of protein. In this study, an HSP90 gene was isolated from Asian paddle crab, Charybdis japonica, as a bio-indicator to monitor the marine ecosystem. Methods This work reports the responses of C. japonica HSP90 mRNA expression to cellular stress by endocrine disrupting chemicals (EDCs), such as bisphenol A (BPA) and 4-nonylphenol (NP) using real-time. reverse transcription polymerase chain reaction. Results The deduced amino acid sequence of HSP90 from C. japonica shared a high degree of homology with their homologues in other species. In a phylogenetic analysis, C. japonica HSP90 is evolutionally related with an ortholog of the other crustacean species. The expression of HSP90 gene was almost distributed in all the examined tissues of the C. japonica crab but expression levels varied among the different body parts of the crabs. We examined HSP90 mRNA expression pattern in C. japonica crabs exposed to EDCs for various exposure times. The expression of HSP90 transcripts was significantly increased in C. japonica crabs exposed to BPA and NP at different concentrations for 12, 24, 48 and 96 hours. The mRNA expression of HSP90 gene was significantly induced in a concentration- and time-dependent manner after BPA or NP exposures for 96 hours. Conclusions Taken together, expression analysis of Asian paddle crab HSP90 gene provided useful molecular information about crab responses in stress conditions and potential ways to monitor the EDCs stressors in marine environments. PMID:24955332

  14. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R.; Martinez-Guitarte, J.L. [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Morcillo, G., E-mail: gmorcillo@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2010-03-01

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl{sub 2}, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

  15. Experimental and numerical studies on the treatment of wet astronaut trash by forced-convection drying

    Science.gov (United States)

    Arquiza, J. M. R. Apollo; Morrow, Robert; Remiker, Ross; Hunter, Jean B.

    2017-09-01

    During long-term space missions, astronauts generate wet trash, including food containers with uneaten portions, moist hygiene wipes and wet paper towels. This waste produces two problems: the loss of water and the generation of odors and health hazards by microbial growth. These problems are solved by a closed-loop, forced-convection, heat-pump drying system which stops microbial activity by both pasteurization and desiccation, and recovers water in a gravity-independent porous media condensing heat exchanger. A transient, pseudo-homogeneous continuum model for the drying of wet ersatz trash was formulated for this system. The model is based on the conservation equations for energy and moisture applied to the air and solid phases and includes the unique trash characteristic of having both dry and wet solids. Experimentally determined heat and mass transfer coefficients, together with the moisture sorption equilibrium relationship for the wet material are used in the model. The resulting system of differential equations is solved by the finite-volume method as implemented by the commercial software COMSOL. Model simulations agreed well with experimental data under certain conditions. The validated model will be used in the optimization of the entire closed-loop system consisting of fan, air heater, dryer vessel, heat-pump condenser, and heat-recovery modules.

  16. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

    1995-01-01

    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  17. Concurrent extraction and reaction for the production of biodiesel from wet microalgae.

    Science.gov (United States)

    Im, Hanjin; Lee, HanSol; Park, Min S; Yang, Ji-Won; Lee, Jae W

    2014-01-01

    This work addresses a reliable in situ transesterification process which integrates lipid extraction from wet microalgae, and its conversion to biodiesel, with a yield higher than 90 wt.%. This process enables single-step production of biodiesel from microalgae by mixing wet microalgal cells with solvent, methanol, and acid catalyst; and then heating them in one pot. The effects of reaction parameters such as reaction temperature, wet cell weight, reaction time, and catalyst volume on the conversion yield are investigated. This simultaneous extraction and transesterification of wet microalgae may enable a significant reduction in energy consumption by eliminating the drying process of algal cells and realize the economic production of biodiesel using wet microalgae. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. [Clothing and heat disorder].

    Science.gov (United States)

    Satsumoto, Yayoi

    2012-06-01

    The influence of the clothing material properties(like water absorbency and rapid dryness, water vapor absorption, water vapor permeability and air permeability) and the design factor of the clothing(like opening condition and fitting of clothing), which contributed to prevent heat disorder, was outlined. WBGT(wet-bulb globe temperature) is used to show a guideline for environmental limitation of activities to prevent heat disorder. As the safety function is more important than thermal comfort for some sportswear and protective clothing with high cover area, clothing itself increases the risk of heat disorder. WBGT is corrected by CAF (clothing adjustment factor) in wearing such kind of protective clothing.

  19. Analysis of the Dryden Wet Bulb GLobe Temperature Algorithm for White Sands Missile Range

    Science.gov (United States)

    LaQuay, Ryan Matthew

    2011-01-01

    In locations where workforce is exposed to high relative humidity and light winds, heat stress is a significant concern. Such is the case at the White Sands Missile Range in New Mexico. Heat stress is depicted by the wet bulb globe temperature, which is the official measurement used by the American Conference of Governmental Industrial Hygienists. The wet bulb globe temperature is measured by an instrument which was designed to be portable and needing routine maintenance. As an alternative form for measuring the wet bulb globe temperature, algorithms have been created to calculate the wet bulb globe temperature from basic meteorological observations. The algorithms are location dependent; therefore a specific algorithm is usually not suitable for multiple locations. Due to climatology similarities, the algorithm developed for use at the Dryden Flight Research Center was applied to data from the White Sands Missile Range. A study was performed that compared a wet bulb globe instrument to data from two Surface Atmospheric Measurement Systems that was applied to the Dryden wet bulb globe temperature algorithm. The period of study was from June to September of2009, with focus being applied from 0900 to 1800, local time. Analysis showed that the algorithm worked well, with a few exceptions. The algorithm becomes less accurate to the measurement when the dew point temperature is over 10 Celsius. Cloud cover also has a significant effect on the measured wet bulb globe temperature. The algorithm does not show red and black heat stress flags well due to shorter time scales of such events. The results of this study show that it is plausible that the Dryden Flight Research wet bulb globe temperature algorithm is compatible with the White Sands Missile Range, except for when there are increased dew point temperatures and cloud cover or precipitation. During such occasions, the wet bulb globe temperature instrument would be the preferred method of measurement. Out of the 30

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

    Directory of Open Access Journals (Sweden)

    A. M. Abdel-Ghany

    2013-01-01

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

  1. Hippocampal 72-kDa heat shock protein expression varies according to mice learning performance independently from chronic exposure to stress.

    Science.gov (United States)

    Ambrosini, Maria Vittoria; Mariucci, Giuseppina; Tantucci, Michela; Van Hooijdonk, Lenneke; Ammassari-Teule, Martine

    2005-01-01

    The possibility that the inducible 72-kDa heat shock protein (hsp72) is involved in learning-related plasticity mechanisms was investigated in two inbred strains of mice that show spontaneous differences in spatial learning performance as well as an opposite reactivity to stress. Induction of hsp72 after radial maze training was measured by immunoblotting in the hippocampus of C57BL/6 (C57) and DBA/2 (DBA) inbred mice exposed or nonexposed to chronic acoustic stress. In agreement with previous studies, inter-strain differences in radial maze performance were found in nonstressed mice with C57 mice showing the higher scores. Chronic acoustic stress, however, impaired performance in the high-learner C57 strain and improved performance in the low-learner DBA strain. Western blot analysis revealed that post-training expression of hsp72 was low in the condition each strain was showing the higher-performance (nonstressed C57 and stressed DBA) and high in the condition each strain was showing the lower performance (stressed C57 and nonstressed DBA). These findings indicate that expression of hsp72 in the hippocampus varies as a function of the learning performance independently from exposure to chronic acoustic stress. (c) 2005 Wiley-Liss, Inc.

  2. Exposure of gnotobiotic Artemia franciscana larvae to abiotic stress promotes heat shock protein 70 synthesis and enhances resistance to pathogenic Vibrio campbellii

    Science.gov (United States)

    Pineda, Carlos; MacRae, Thomas H.; Sorgeloos, Patrick; Bossier, Peter

    2008-01-01

    Larvae of the brine shrimp Artemia franciscana serve as important feed in fish and shellfish larviculture; however, they are subject to bacterial diseases that devastate entire populations and consequently hinder their use in aquaculture. Exposure to abiotic stress was shown previously to shield Artemia larvae against infection by pathogenic Vibrio, with the results suggesting a mechanistic role for heat shock protein 70. In the current report, combined hypothermic/hyperthermic shock followed by recovery at ambient temperature induced Hsp70 synthesis in Artemia larvae. Thermotolerance was also increased as was protection against infection by Vibrio campbellii, the latter indicated by reduced mortality and lower bacterial load in challenge tests. Resistance to Vibrio improved in the face of declining body mass as demonstrated by measurement of ash-free dry weight. Hypothermic stress only and acute osmotic insult did not promote Hsp70 expression and thermotolerance in Artemia larvae nor was resistance to Vibrio challenge augmented. The data support a causal link between Hsp70 accumulation induced by abiotic stress and enhanced resistance to infection by V. campbellii, perhaps via stimulation of the Artemia immune system. This possibility is now under investigation, and the work may reveal fundamental properties of crustacean immunity. Additionally, the findings are important in aquaculture where development of procedures to prevent bacterial infection of feed stock such as Artemia larvae is a priority. PMID:18347942

  3. The surface state of hematite and its wetting characteristics.

    Science.gov (United States)

    Shrimali, Kaustubh; Jin, Jiaqi; Hassas, Behzad Vaziri; Wang, Xuming; Miller, Jan D

    2016-09-01

    Apart from being a resource for iron/steel production, the iron oxide minerals, goethite and hematite, are used in the paint, cosmetics, and other industries as pigments. Surface characteristics of these minerals have been studied extensively both in resource recovery by flotation and in the preparation of colloidal dispersions. In this current research, the wetting characteristics of goethite (FeOOH) and hematite (Fe2O3) have been analyzed by means of contact angle, bubble attachment time, and Atomic Force Microscopy (AFM) measurements as well as by Molecular Dynamics Simulation (MDS). Goethite is naturally hydroxylated and wetted by water at all pH values. In contrast, the anhydrous hematite surface (001) was found to be slightly hydrophobic at natural pH values with a contact angle of about 50°. At alkaline pH hydroxylation of the hematite surface occurs rapidly and the hematite becomes hydrophilic. The wetting characteristics of the hematite surface then vary between the hydrophobic anhydrous hematite and the completely hydrophilic hydroxylated hematite, similar to goethite. The hydrophobicity can be restored by heating of the hydroxylated hematite surface at 60°C. The hydrophobic character of the anhydrous hematite (001) surface is confirmed by MDS which also reveals that after hydrolysis the hematite (001) surface can be wetted by water, similar to the goethite (001) surface. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Wetting characteristics of 3-dimensional nanostructured fractal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ethan, E-mail: ethan.davis4@huskers.unl.edu [Nano & Microsystems Research Laboratory, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, NE 68588-0526 (United States); Liu, Ying; Jiang, Lijia; Lu, Yongfeng [Laser Assisted Nano Engineering Lab, Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, 209N Scott Engineering Center, Lincoln, NE 68588-0511 (United States); Ndao, Sidy, E-mail: sndao2@unl.edu [Nano & Microsystems Research Laboratory, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, NE 68588-0526 (United States)

    2017-01-15

    Highlights: • Hierarchically structured surfaces were fabricated on the micro/nano-scale. • These structures reduced the contact angle of the inherently hydrophilic material. • Similar surfaces have applications in two-phase heat transfer and microfluidics. - Abstract: This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

  5. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  6. Wet/Dry Vacuum Cleaner

    Science.gov (United States)

    Reimers, Harold; Andampour, Jay; Kunitser, Craig; Thomas, Ike

    1995-01-01

    Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

  7. Evaluation of heat stress in dry cleaner units:A case study in Qom, Iran

    Directory of Open Access Journals (Sweden)

    Javad Malakouti

    2016-04-01

    Full Text Available Background & Aims of the Study: Nowadays, heat stress is one of the most harmful physical agents in workplaces. According to the consequences of heat stress and have no information about it in Qom dry cleaner units, Iran, this study have been designed to evaluate the heat stress among workers of dry cleaner units in Qom province of Iran, in Jul-Aug 2011. Materials & Methods: This cross-sectional study was conducted in 113 units of active dry cleaner units. WBGT (Wet Bulb Globe Temperature index was selected for heat stress evaluation. In order to measure the requisite parameters, WBGT meter made of Casella Company had been used according to ISO 7243. Data had been analyzed according to Occupational Exposure Limits (OELs with SPSS V.16, using analysis of variance, independent T and LSD tests. Results: The average of WBGT index in Qom dry cleaner units of Iran were 28.98±1.64 °C. The average of WBGT index in 66.4% of units was up to 28°C. The average of relative humidity was 42.86%, the average of wet bulb temperature and globe temperature were 25.56°C and 36.72°C, respectively. The findings showed a significant correlation between the average of WBGT index and the standard recommendation level (p<0.0001. In dry cleaner units with less than 10 m2 area, heat stress was higher than other units  significantly (p<0.05. Conclusions: Heat stress in many dry cleaner units in Qom, Iran, was more than recommended OELs. Because of wet bulb and globe temperature in units were high value, the most important measures to heat controls, are technical engineering controls such as  radiation shield, insulation on boilers and modify the cooling systems.

  8. Occupational heat stress assessment and protective strategies in the context of climate change

    Science.gov (United States)

    Gao, Chuansi; Kuklane, Kalev; Östergren, Per-Olof; Kjellstrom, Tord

    2017-04-01

    Global warming will unquestionably increase the impact of heat on individuals who work in already hot workplaces in hot climate areas. The increasing prevalence of this environmental health risk requires the improvement of assessment methods linked to meteorological data. Such new methods will help to reveal the size of the problem and design appropriate interventions at individual, workplace and societal level. The evaluation of occupational heat stress requires measurement of four thermal climate factors (air temperature, humidity, air velocity and heat radiation); available weather station data may serve this purpose. However, the use of meteorological data for occupational heat stress assessment is limited because weather stations do not traditionally and directly measure some important climate factors, e.g. solar radiation. In addition, local workplace environmental conditions such as local heat sources, metabolic heat production within the human body, and clothing properties, all affect the exchange of heat between the body and the environment. A robust occupational heat stress index should properly address all these factors. This article reviews and highlights a number of selected heat stress indices, indicating their advantages and disadvantages in relation to meteorological data, local workplace environments, body heat production and the use of protective clothing. These heat stress and heat strain indices include Wet Bulb Globe Temperature, Discomfort Index, Predicted Heat Strain index, and Universal Thermal Climate Index. In some cases, individuals may be monitored for heat strain through physiological measurements and medical supervision prior to and during exposure. Relevant protective and preventive strategies for alleviating heat strain are also reviewed and proposed.

  9. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  10. How many days are required for workers to acclimatize to heat?

    Science.gov (United States)

    Khalaf, Tamer Mohamed; Ramadan, Mohamed Zaki; Al-Ashaikh, Riyad A

    2017-01-01

    Many research studies require recruiting heat-acclimatized workers to participate in heat-stress experiments and application fields. A reliable heat acclimatization program for workers in countries with hot environments has not been reported yet. The objective of this study was to estimate the effects of heat stress and the amount of acclimatization required in hot-climate countries. Eighteen male workers from an industrial population participated in this experiment. Nine days of exposure to a hot environment (wet-bulb globe temperature, 30°C) was the independent variable. The participants' cardiac costs and increment aural-canal temperatures were the dependent variables. The study results revealed that 5 days of exposure to heat sessions were sufficient to heat acclimatize the workers based on their physiological responses (i.e., heart rate and aural-canal temperature). According to the available literature, workers in hot climate countries, similar to the study cohort, can heat acclimatize faster than those in other Western countries.

  11. Occupational Heat Stress Impacts on Health and Productivity in a Steel Industry in Southern India.

    Science.gov (United States)

    Krishnamurthy, Manikandan; Ramalingam, Paramesh; Perumal, Kumaravel; Kamalakannan, Latha Perumal; Chinnadurai, Jeremiah; Shanmugam, Rekha; Srinivasan, Krishnan; Venugopal, Vidhya

    2017-03-01

    Workers laboring in steel industries in tropical settings with high ambient temperatures are subjected to thermally stressful environments that can create well-known risks of heat-related illnesses and limit workers' productivity. A cross-sectional study undertaken in a steel industry in a city nicknamed "Steel City" in Southern India assessed thermal stress by wet bulb globe temperature (WBGT) and level of dehydration from urine color and urine specific gravity. A structured questionnaire captured self-reported heat-related health symptoms of workers. Some 90% WBGT measurements were higher than recommended threshold limit values (27.2-41.7°C) for heavy and moderate workloads and radiational heat from processes were very high in blooming-mill/coke-oven (67.6°C globe temperature). Widespread heat-related health concerns were prevalent among workers, including excessive sweating, fatigue, and tiredness reported by 50% workers. Productivity loss was significantly reported high in workers with direct heat exposures compared to those with indirect heat exposures (χ2 = 26.1258, degrees of freedom = 1, p work capacities. Health and productivity risks in developing tropical country work settings can be further aggravated by the predicted temperature rise due to climate change, without appropriate interventions. Apart from industries enhancing welfare facilities and designing control interventions, further physiological studies with a seasonal approach and interventional studies are needed to strengthen evidence for developing comprehensive policies to protect workers employed in high heat industries.

  12. Analysis of the Electrospray Plume from the EMI-Im Propellant Externally Wetted on a Tungsten Needle

    National Research Council Canada - National Science Library

    Chiu, Yu-Hui; Gaeta, Geraldine; Heine, Thomas R; Dressler, Rainer A; Levandier, Dale J

    2006-01-01

    ... in a low specific impulse. Recently, pure ion emission was achieved for EMI-Im in a wetted needle thruster, suggesting that this propellant, which has passed all space environmental exposure tests, may also be a candidate...

  13. Estimation of respiratory heat flows in prediction of heat strain among Taiwanese steel workers

    Science.gov (United States)

    Chen, Wang-Yi; Juang, Yow-Jer; Hsieh, Jung-Yu; Tsai, Perng-Jy; Chen, Chen-Peng

    2017-01-01

    International Organization for Standardization 7933 standard provides evaluation of required sweat rate (RSR) and predicted heat strain (PHS). This study examined and validated the approximations in these models estimating respiratory heat flows (RHFs) via convection ( C res) and evaporation ( E res) for application to Taiwanese foundry workers. The influence of change in RHF approximation to the validity of heat strain prediction in these models was also evaluated. The metabolic energy consumption and physiological quantities of these workers performing at different workloads under elevated wet-bulb globe temperature (30.3 ± 2.5 °C) were measured on-site and used in the calculation of RHFs and indices of heat strain. As the results show, the RSR model overestimated the C res for Taiwanese workers by approximately 3 % and underestimated the E res by 8 %. The C res approximation in the PHS model closely predicted the convective RHF, while the E res approximation over-predicted by 11 %. Linear regressions provided better fit in C res approximation ( R 2 = 0.96) than in E res approximation ( R 2 ≤ 0.85) in both models. The predicted C res deviated increasingly from the observed value when the WBGT reached 35 °C. The deviations of RHFs observed for the workers from those predicted using the RSR or PHS models did not significantly alter the heat loss via the skin, as the RHFs were in general of a level less than 5 % of the metabolic heat consumption. Validation of these approximations considering thermo-physiological responses of local workers is necessary for application in scenarios of significant heat exposure.

  14. Thermal insulation of wet shielded metal arc welds

    Science.gov (United States)

    Keenan, Patrick J.

    1993-06-01

    Computational and experimental studies were performed to determine the effect of static thermal insulation on the quality of wet shielded metal arc welds (SMAW). A commercially available heat flow and fluid dynamics spectral-element computer program was used to model a wet SMAW and to determine the potential effect on the weld cooling rate of placing thermal insulation adjacent to the weld line. Experimental manual welds were made on a low carbon equivalent (0.285) mild steel and on a higher carbon equivalent (0.410) high tensile strength steel, using woven fabrics of alumina-boria-silica fibers to insulate the surface of the plate being welded. The effect of the insulation on weld quality was evaluated through the use of post-weld Rockwell Scale hardness measurements on the surface of the weld heat affected zones (HAZ's) and by visual inspection of sectioned welds at 10 X magnification. The computational simulation demonstrated a 150% increase in surface HAZ peak temperature and a significant decrease in weld cooling rate with respect to uninsulated welds, for welds in which ideal insulation had been placed on the base plate surface adjacent to the weld line. Experimental mild steel welds showed a reduction in surface HAZ hardness attributable to insulation at a 77% significance level. A visual comparison of the cross-sections of two welds made in 0.410 carbon equivalent steel-with approximately equivalent heat input-revealed underbead cracking in the uninsulated weld but not in the insulated weld.

  15. Differential wetting characterization of hair fibers.

    Science.gov (United States)

    Vaynberg, Abe; Stuart, Mark; Wu, Xiang-Fa

    2012-01-01

    Surface wetting is one of the key properties of human hair used to indicate the extent of chemical/mechanical damage and the outcome of conditioning treatment. Characterization of hair wetting property is a challenging task due to the non-homogeneous nature of hair fibers and the requirement for sensitive equipment. Motivated by these considerations, we developed a new methodology, termed a differential wetting characterization (DWC), which would allow rapid and reliable characterization of the wetting property of hair fibers. This method is based on observation of a number of droplets suspended on a pair of parallel fibers stretched in a horizontal plane. The wetting behavior of the fibers can be deduced from the shape assumed by the droplets. When the wetting properties of the two hair fibers are identical, the droplets suspended between the fibers assume a symmetric configuration. In contrast, on the fibers with dissimilar wetting characteristics, the droplets will assume a skewed configuration towards a more hydrophilic fiber. This makes it possible to differentiate the hydrophobicities of the tested fibers. In this paper it is demonstrated that the proposed DWC method is capable of differentiating the changes in wetting property of hair surfaces in response to either chemical or physical treatment. Results of the paper indicate that the DWC method is applicable for broad wetting differentiation of various fibers.

  16. Carbon nanotube fiber spun from wetted ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  17. Development of Wet-Etching Tools for Precision Optical Figuring

    Energy Technology Data Exchange (ETDEWEB)

    Rushford, M C; Dixit, S N; Hyde, R; Britten, J A; Nissen, J; Aasen, M; Toeppen, J; Hoaglan, C; Nelson, C; Summers, L; Thomas, I

    2004-01-27

    This FY03 final report on Wet Etch Figuring involves a 2D thermal tool. Its purpose is to flatten (0.3 to 1 mm thickness) sheets of glass faster thus cheaper than conventional sub aperture tools. An array of resistors on a circuit board was used to heat acid over the glass Optical Path Difference (OPD) thick spots and at times this heating extended over the most of the glass aperture. Where the acid is heated on the glass it dissolves faster. A self-referencing interferometer measured the glass thickness, its design taking advantage of the parallel nature and thinness of these glass sheets. This measurement is used in close loop control of the heating patterns of the circuit board thus glass and acid. Only the glass and acid were to be moved to make the tool logistically simple to use in mass production. A set of 4-circuit board, covering 80 x 80-cm aperture was ordered, but only one 40 x 40-cm board was put together and tested for this report. The interferometer measurement of glass OPD was slower than needed on some glass profiles. Sometimes the interference fringes were too fine to resolve which would alias the sign of the glass thickness profile. This also caused the phase unwrapping code (FLYNN) to struggle thus run slowly at times taking hours, for a 10 inch square area. We did extensive work to improve the speed of this code. We tried many different phase unwrapping codes. Eventually running (FLYNN) on a farm of networked computers. Most of the work reported here is therefore limited to a 10-inch square aperture. Researched into fabricating a better interferometer lens from Plexiglas so to have less of the scattered light issues of Fresnel lens groves near field scattering patterns, this set the Nyquest limit. There was also a problem with the initial concept of wetting the 1737 glass on its bottom side with acid. The wetted 1737 glass developed an Achromatic AR coating, spoiling the reflection needed to see glass thickness interference fringes. In response

  18. Evaluation of the Tobacco Heating System 2.2. Part 7: Systems toxicological assessment of a mentholated version revealed reduced cellular and molecular exposure effects compared with mentholated and non-mentholated cigarette smoke.

    Science.gov (United States)

    Kogel, Ulrike; Titz, Bjoern; Schlage, Walter K; Nury, Catherine; Martin, Florian; Oviedo, Alberto; Lebrun, Stefan; Elamin, Ashraf; Guedj, Emmanuel; Trivedi, Keyur; Ivanov, Nikolai V; Vanscheeuwijck, Patrick; Peitsch, Manuel C; Hoeng, Julia

    2016-11-30

    Modified risk tobacco products (MRTPs) are being developed with the aim of reducing smoking-related health risks. The Tobacco Heating System 2.2 (THS2.2) is a candidate MRTP that uses the heat-not-burn principle. Here, systems toxicology approaches were engaged to assess the respiratory effects of mentholated THS2.2 (THS2.2M) in a 90-day rat inhalation study (OECD test guideline 413). The standard endpoints were complemented by transcriptomics and quantitative proteomics analyses of respiratory nasal epithelium and lung tissue and by lipidomics analysis of lung tissue. The adaptive response of the respiratory nasal epithelium to conventional cigarette smoke (CS) included squamous cell metaplasia and an inflammatory response, with high correspondence between the molecular and histopathological results. In contrast to CS exposure, the adaptive tissue and molecular changes to THS2.2M aerosol exposure were much weaker and were limited mostly to the highest THS2.2M concentration in female rats. In the lung, CS exposure induced an inflammatory response, triggered cellular stress responses, and affected sphingolipid metabolism. These responses were not observed or were much lower after THS2.2M aerosol exposure. Overall, this system toxicology analysis complements and reconfirms the results from classical toxicological endpoints and further suggests potentially reduced health risks of THS2.2M. Copyright © 2016. Published by Elsevier Inc.

  19. Elemental mercury removal using a wet scrubber.

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Livengood, C. D.; Martin, K.; Mendelsohn, M. H.; Zhou, C. Q.

    1999-05-19

    Mercury (Hg) is a toxic metal that is emitted into the environment by both natural and human activities. Acute and chronic exposure to mercury and methyl mercury in humans results in central nervous system damage, kidney damage, and even death. Although some Hg emission sources have been regulated, coal-fired utilities have not been. In anticipation of federal regulations on mercury emissions from coal-fired power plants, Argonne National Laboratory (ANL) has designed a flue gas simulation system to study the removal of elemental mercury. The simulated flue gas enters the system and combines with the inlet mercury vapor (from a calibrated permeation tube), carried by nitrogen gas. This combined gas continues past the flow meter and the pressure gage to the reactor inlet. Inside the reactor chamber, the flue gas is sprayed with NOXSORB{reg_sign}, a chloric acid solution, which reacts with elemental mercury. The amount of reaction (oxidation) of elemental mercury is important since mercury in an oxidized form is highly soluble, In this form, the Hg can be picked up downstream by a wet scrubber from fossil-fuel burning utilities. Experiments on mercury removal from flue gases have been conducted at ANL, with the participation of a senior design team from Purdue University Calumet. Temperature variations ranging from room temperature to 350 F have been studied. Other parameters, such as the concentration of NOXSORB{reg_sign}, were also tested. Furthermore, pump speed and sprayer droplet sizes of the NOXSORB{reg_sign} solution were studied. A literature survey on the current and proposed mercury control legislation, along with the existing control technologies, has been performed as part of the senior design project. With guidance from ANL, an understanding of the simulation system has been developed. This information has been used to determine the mass transfer. Another literature survey was performed on the reaction kinetics of mercury. The information obtained was

  20. Moist Heat or Dry Heat for Delayed Onset Muscle Soreness

    OpenAIRE

    Petrofsky, Jerrold; Berk, Lee; Bains, Gurinder; Khowailed, Iman Akef; Hui, Timothy; Granado, Michael; Laymon, Mike; Lee, Haneul

    2013-01-01

    Background Heat is commonly used in physical therapy following exercise induced delayed onset muscle soreness (DOMS). Most heat modalities used in a clinical setting for DOMS are only applied for 5 to 20 minutes. This minimal heat exposure causes little, if any, change in deep tissue temperature. For this reason, long duration dry chemical heat packs are used at home to slowly and safely warm tissue and reduce potential heat damage while reducing pain associated from DOMS. Clinically, it has ...

  1. Evaluating work/recovery schedules in terms of whole body heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Hardcastle, S.G. [Natural Resources Canada, Sudbury, ON (Canada). CANMET Mining and Mineral Sciences Laboratories; Stapleton, J.M.; Kenny, G.P. [Ottawa Univ., Ottawa, ON (Canada). School of Human Kinetics, Human and Environmental Physiology Research Unit; Allen, C. [Vale Inco, Copper Cliff, ON (Canada)

    2010-07-01

    This paper reported on heat stress related research aimed at better managing the heat exposure of underground miners. The potential for underground miners to experience heat stress or strain is increasing due to greater mining depth; mechanization, and a trend towards larger diesel equipment; an aging workforce; an increasing amount of personal protective equipment worn to prevent injuries (that has led to most of the miner's body being covered) and increases in the surface climate that are superimposed through the underground workplace. This paper focused on research involving metabolic heat storage and the possibility of heat strain from elevated core temperatures. It targeted work/recovery cycles and the recovery strategies between work bouts. The first study examined the cumulative change in body heat content for a moderate metabolic rate and increasing the recovery allocation as per the TLV screening criteria to offset an increase in the wet bulb globe temperature (WBGT). The second study examined strategies that could be used between work bouts and how they affect the thermoregulatory system, heat generation or losses and net cumulative heat storage. The calorimeter based work suggested that a miner's clothing may be improved to promote evaporative cooling, and that work recovery regimes could be modified to maximize recovery. 10 refs., 1 tab., 6 figs.

  2. Defined wetting properties of optical surfaces

    Science.gov (United States)

    Felde, Nadja; Coriand, Luisa; Schröder, Sven; Duparré, Angela; Tünnermann, Andreas

    2017-10-01

    Optical surfaces equipped with specific functional properties have attracted increasing importance over the last decades. In the light of cost reduction, hydrophobic self-cleaning behavior is aspired. On the other side, hydrophilic properties are interesting due to their anti-fog effect. It has become well known that such wetting states are significantly affected by the surface morphology. For optical surfaces, however, this fact poses a problem, as surface roughness can induce light scattering. The generation of optical surfaces with specific wetting properties, hence, requires a profound understanding of the relation between the wetting and the structural surface properties. Thus, our work concentrates on a reliable acquisition of roughness data over a wide spatial frequency range as well as on the comprehensive description of the wetting states, which is needed for the establishment of such correlations. We will present our advanced wetting analysis for nanorough optical surfaces, extended by a vibration-based procedure, which is mainly for understanding and tailoring the wetting behavior of various solid-liquid systems in research and industry. Utilizing the relationships between surface roughness and wetting, it will be demonstrated how different wetting states for hydrophobicity and hydrophilicity can be realized on optical surfaces with minimized scatter losses.

  3. 7 CFR 29.1083 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.1083 Section 29.1083 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1083 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in...

  4. 7 CFR 29.2570 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2570 Section 29.2570 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2570 Wet (W). Any sound tobacco containing...

  5. 7 CFR 29.3077 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3077 Section 29.3077 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in an unsafe or...

  6. 7 CFR 29.2316 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2316 Section 29.2316 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2316 Wet (W...

  7. 7 CFR 29.3567 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3567 Section 29.3567 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3567 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in...

  8. SAR-sensing of vegetation wetness

    NARCIS (Netherlands)

    de Jong, JJM; Klaassen, W

    1998-01-01

    The goal of this study is to measure rain induced forest canopy wetness. The approach used is ERS tandem mission C-band SAR backscatter change detection between successive dry and rainy days. The observed backscatter change is positively related with modelled canopy wetness change. It is therefore

  9. Dynamic wetting at the nanoscale

    Science.gov (United States)

    Amberg, Gustav; Nakamura, Yoshinori; Carlson, Andreas; Shiomi, Junichiro

    2013-11-01

    Although the capillary spreading of a drop on a dry substrate is well studied, the physical mechanisms that govern the dynamics remain challenging. Here we study the dynamics of spreading of partially wetting nano-droplets, by combining molecular dynamics and continuum simulations. The latter accounts for all the relevant hydrodynamics, i.e. capillarity, inertia and viscous stresses. By coordinated continuum and molecular dynamics simulations, the macroscopic model parameters are extracted. For a Lennard-Jones fluid spreading on a planar surface, the liquid slip on the substrate is found to be crucial for the motion of the contact line. Evaluation of the different contributions to the energy transfer shows that the liquid slip generates dissipation of the same order as the bulk viscous dissipation or the energy transfer to kinetic energy. We also study the dynamics of spreading on a substrate with a periodic nanostructure. Here it is found that a nanostructure with a length scale commensurate with molecular size completely inhibits the liquid slip. This reduces the spreading speed by about 30%. This work is partially supported by the Japan Science and Technology Agency, CREST, the Swedish Research Council, the Japan Society for the Promotion of Science, and the Sasakawa foundation.

  10. Condensation and Wetting Dynamics on Micro/Nano-Structured Surfaces

    Science.gov (United States)

    Olceroglu, Emre

    Because of their adjustable wetting characteristics, micro/nanostructured surfaces are attractive for the enhancement of phase-change heat transfer where liquid-solid-vapor interactions are important. Condensation, evaporation, and boiling processes are traditionally used in a variety of applications including water harvesting, desalination, industrial power generation, HVAC, and thermal management systems. Although they have been studied by numerous researchers, there is currently a lack of understanding of the underlying mechanisms by which structured surfaces improve heat transfer during phase-change. This PhD dissertation focuses on condensation onto engineered surfaces including fabrication aspect, the physics of phase-change, and the operational limitations of engineered surfaces. While superhydrophobic condensation has been shown to produce high heat transfer rates, several critical issues remain in the field. These include surface manufacturability, heat transfer coefficient measurement limitations at low heat fluxes, failure due to surface flooding at high supersaturations, insufficient modeling of droplet growth rates, and the inherent issues associated with maintenance of non-wetted surface structures. Each of these issues is investigated in this thesis, leading to several contributions to the field of condensation on engineered surfaces. A variety of engineered surfaces have been fabricated and characterized, including nanostructured and hierarchically-structured superhydrophobic surfaces. The Tobacco mosaic virus (TMV) is used here as a biological template for the fabrication of nickel nanostructures, which are subsequently functionalized to achieve superhydrophobicity. This technique is simple and sustainable, and requires no applied heat or external power, thus making it easily extendable to a variety of common heat transfer materials and complex geometries. To measure heat transfer rates during superhydrophobic condensation in the presence of non

  11. Description and cost analysis of a deluge dry/wet cooling system.

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; Bamberger, J.A.; Braun, D.J.; Braun, D.J.; Faletti, D.W.; Willingham, C.E.

    1978-06-01

    The use of combined dry/wet cooling systems for large base-load power plants offers the potential for significant water savings as compared to evaporatively cooled power plants and significant cost savings in comparison to dry cooled power plants. The results of a detailed engineering and cost study of one type of dry/wet cooling system are described. In the ''deluge'' dry/wet cooling method, a finned-tube heat exchanger is designed to operate in the dry mode up to a given ambient temperature. To avoid the degradation of performance for higher ambient temperatures, water (the delugeate) is distributed over a portion of the heat exchanger surface to enhance the cooling process by evaporation. The deluge system used in this study is termed the HOETERV system. The HOETERV deluge system uses a horizontal-tube, vertical-plate-finned heat exchanger. The delugeate is distributed at the top of the heat exchanger and is allowed to fall by gravity in a thin film on the face of the plate fin. Ammonia is used as the indirect heat transfer medium between the turbine exhaust steam and the ambient air. Steam is condensed by boiling ammonia in a condenser/reboiler. The ammonia is condensed in the heat exchanger by inducing airflow over the plate fins. Various design parameters of the cooling system have been studied to evaluate their impact on the optimum cooling system design and the power-plant/utility-system interface. Annual water availability was the most significant design parameter. Others included site meteorology, heat exchanger configuration and air flow, number and size of towers, fan system design, and turbine operation. It was concluded from this study that the HOETERV deluge system of dry/wet cooling, using ammonia as an intermediate heat transfer medium, offers the potential for significant cost savings compared with all-dry cooling, while achieving substantially reduced water consumption as compared to an evaporatively cooled power plant. (LCL)

  12. An Environmental Stress Index (ESI) as a Substitute for the Wet Bulb Globe Temperature (WBGT)

    Science.gov (United States)

    2001-02-01

    This report summarizes the development of a new environmental stress index (ESI) to asses heat stress. Two independent studies containing four...develop a new environmental stress index (ESI). Meteorological measurements were taken in three climatic zones (hot/wet, hot/dry, and extremely hot/dry

  13. Occurrence of temperature spikes at a wetting front during spontaneous imbibition

    NARCIS (Netherlands)

    Aslannejad, H.|info:eu-repo/dai/nl/407629629; Terzis, A.; Hassanizadeh, S.M.|info:eu-repo/dai/nl/074974424; Weigard, Bernhard

    2017-01-01

    It is reported that temperature rises at wetting front during water infiltration into soil. The temperature goes back to the background value after passage of water front. Different explanations have been provided for source of energy causing temperature spike. Some have contributed it to heat of

  14. Evaluation of occupation hot exposure in industrial workplaces in a subtropical country.

    Science.gov (United States)

    Yang, Yu-Chiao; Wei, Ming-Chi; Hong, Show-Jen

    2017-05-08

    The objective of this study has been to evaluate the occupational heat exposure of 12 workers at 5 plants in a subtropical country. The heat stresses and strain on workers in 5 plants were assessed by the International Organization for Standardization (ISO) 7243 index (wet bulb globe temperature - WBGT) and the ISO 7933 index (maximum allowable exposure time - Dlim). Results indicated that 42% of the subjects (5 workers) surpassed the WBGT limits. According to the Dlim, 42% of the subjects could not continue working in the hot environments. The relationships between the various heat stress indices and the WBGT index were also correlated. However, further studies from different heat environments and more subjects should be performed. The sensitive dependence of skin temperature on meteorological and physiological indices for each subject was clearly observed. Obviously, the heart rate response to metabolic rate was much greater than that caused by environmental heat alone. The exponential relationship between workers' duration-limited exposure time, predicted by various estimated criteria, and WBGT were also found. Int J Occup Med Environ Health 2017;30(3):379-395.

  15. Technical Efficiency of Wet Season Melon Farming

    Directory of Open Access Journals (Sweden)

    Ananti Yekti

    2017-03-01

    Full Text Available Melon is one of high-value horticulture commodity which is cultivated widely in Kulon Progo regency. The nature of agricultural products is heavily dependent on the season, so it causes the prices of agricultural products always fluctuated every time. In wet season the price of agricultural products tends to be more expensive. Melon cultivation in wet season provide an opportunity to earn higher profits than in the dry season. The price of agricultural products tends to be more expensive in wet season, thus melon cultivation in wet season prospectively generate high profits. In order to achieve high profitability, melon farming has to be done efficiently. Objective of this study was to 1 determined the factors that influence melon production in wet season 2 measured technical efficiency of melon farming and 3 identified the factors that influanced technical efficiency. Data collected during April – June 2014. Location determined by multistage cluster sampling. 45 samples of farmers who cultivated melon during wet season obtained based on quota sampling technique. Technical efficiency was measured using Cobb-Douglas Stochastic Frontier. The result reveals that 1 land use, quantity of seed, K fertilizer contributed significantly increasing melon production, while N fertilizer decreased melon production significantly 2 technical efficiency indeces ranged from 0.40 to 0.99, with a mean of  0.77; 3 farmer’s experience gave significant influence to technical efficiency of melon farming in wet season.

  16. Heat loss of heat pipelines in insulation moisture conditions with the evaporation

    Directory of Open Access Journals (Sweden)

    Polovnikov Vyacheslav Yu.

    2014-01-01

    Full Text Available Results of numerical simulation of heat and mass transfer in a wet fibroporous material in conditions of evaporation and steam diffusion were obtained. Values of heat and mass fluxes were established. The contribution of evaporation effect to total heat flux and need to consider volume fractions of water and steam into the structure of fibroporous material in calculation of effective thermal conductivity were shown. Nonstationarity of heat and mass transfer in conditions of considered problem can be ignored.

  17. Wet melting along the Tonga Volcanic Arc

    Science.gov (United States)

    Cooper, L. B.; Plank, T.; Arculus, R. J.; Hauri, E. H.; Hall, P.

    2010-12-01

    Melting in the mantle at convergent margins is driven by water from the subducting slab. Previous work has found a strong role for water-fluxed melting from correlations between the concentration of water in the mantle source, (H2O)o, and the extent of melting beneath backarcs, Fba. Here we explore how wet melting beneath the Lau Backarc Basin relates to that beneath the Tonga Arc, Farc, by providing the first systematic study of water contents in Tonga arc magmas. We have measured volatiles and major and trace elements in melt inclusions, glasses, and whole rocks obtained from recently sampled submarine and subaerial Tonga arc volcanoes. The compositions are varied and range mostly between andesite and basalt/boninite, and least-degassed water contents range from 2 to 5 wt%. We estimate (H2O)o and Farc independently by combining pressure (P) and temperature (T) estimates from an olivine-orthopyroxene-melt thermobarometer with a wet melting productivity model. When P, T, and (H2O)o are known, Farc is uniquely constrained. Results for the volcanoes in the Tonga Arc are bimodal with respect to T: volcanoes located near active backarc spreading centers reflect cooler melting (~1275°C) than those located far from active spreading centers (~1365°C). The cooler primary T’s may result from removal of the heat of fusion during prior melting beneath the Lau backarc, Fba. In the northern portion of the arc, the warmest primary T’s may be due to proximity to the Samoan mantle plume. Farc varies non-systematically along-strike, indicating that Fba is the primary driver of along-arc variability in primary melt compositions. Farc can also be used to calculate the TiO2 concentration of the arc mantle source, (TiO2)o (a proxy for source depletion), which varies monotonically along the Tonga Arc. Arc volcanoes adjacent to the Southern Lau Rifts and Valu Fa Ridge melt mantle with a fertile N-MORB TiO2, while those adjacent to the northern extent of the Eastern Lau Spreading

  18. Wet granular matter a truly complex fluid

    CERN Document Server

    Herminghaus, Stephan

    2013-01-01

    This is a monograph written for the young and advanced researcher who is entering the field of wet granular matter and keen to understand the basic physical principles governing this state of soft matter. It treats wet granulates as an instance of a ternary system, consisting of the grains, a primary, and a secondary fluid. After addressing wetting phenomena in general and outlining the basic facts on dry granular systems, a chapter on basic mechanisms and their effects is dedicated to every region of the ternary phase diagram. Effects of grain shape and roughness are considered as well. Rather than addressing engineering aspects such as existing books on this topic do, the book aims to provide a generalized framework suitable for those who want to understand these systems on a more fundamental basis. Readership: For the young and advanced researcher entering the field of wet granular matter.

  19. ROE Wet Nitrate Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 2011 to 2013. Summary data in this indicator were provided by EPA’s...

  20. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  1. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  2. Research on stress corrosion behavior of CCSE40 welded by underwater wet welding with austenitic welding rod in seawater

    Science.gov (United States)

    Zou, Y.; Bai, Q.; Dong, S.; Yang, Z. L.; Gao, Y.

    2017-09-01

    The stress corrosion behavior of CCSE40 welded by underwater wet welding with austenitic welding rod in seawater was studied. Microstructure, mechanical property and stress corrosion cracking susceptibility of the underwater wet welding joint were analyzed by metallographic observation, tensile and bending tests, slow strain rate test (SSRT) and SEM. The results indicated that the weld zone (WZ) and the heat affected zone (HAZ) were all sensitive to the stress corrosion, and the WZ was more sensitive than the HAZ.

  3. Biodegradation of wet-white leather

    OpenAIRE

    Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna

    2011-01-01

    This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier.

  4. Thermal neutron diffusion cooling in wet quartz

    Energy Technology Data Exchange (ETDEWEB)

    Drozdowicz, K. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)]. E-mail: krzysztof.drozdowicz@ifj.edu.pl; Krynicka, E. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Crakcw (Poland); Dabrowska, J. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)

    2007-07-15

    The thermal neutron diffusion parameters of a rock material depend on the rock matrix itself and on the water content. The effect has been studied in quartz by Monte Carlo (MC) simulations of the variable buckling experiment for nine series of samples. A hyperbolic dependence of the density-removed diffusion cooling coefficient on the water content shows a variability of this parameter by two orders of magnitude. The function obtained for wet quartz is compared with the analogous dependence for wet dolomite.

  5. Study of the comparative costs of five wet/dry cooling tower concepts

    Energy Technology Data Exchange (ETDEWEB)

    Zaloudek, F.R.; Allemann, R.T.; Faletti, D.W.; Johnson, B.M.; Parry, H.L.; Smith, G.C.; Tokarz, R.D.; Walter, R.A.

    1976-09-01

    The projected cost of five alternative dry/wet power plant heat rejection concepts was studied under conditions imposed by hypothetical use in association with the San Juan Plant Unit 3, a 550-MWe facility currently under construction near the ''Four Corners'' area of New Mexico. The five alternative concepts were: integrated dry/wet tower; separate dry and wet towers; metal fin-tube induced draft tower with deluge water augmentation; plastic heat exchanger tower with deluge water augmentation, and metal fin-tube/deluge augmentation tower with an intermediate ammonia evaporation-condensation condenser and the cooling tower. The integrated dry/wet tower concept, already chosen for service at San Juan Unit 3, was included for reference purposes. All concepts were conceptually designed and estimated using the same bases and employing uniform practices. Each concept was assumed to use all water allocated for consumptive use in Unit 3. The cost estimates obtained showed the following descending order of ''comparable capital cost'': separate dry/wet; metal fin-tube/deluge; integrated dry/wet; plastic tube/deluge; and metal fin-tube/deluge/ammonia. The results indicate that two of the advanced concepts considered, i.e., the plastic tube/deluge concept and the metal fin tube/deluge/ammonia concept, can possibly reduce the overall costs of dry/wet cooling under conditions imposed by the site considered. It was recommended that these two concepts receive additional attention by the ERDA Dry Cooling Tower Program and industry to further quantify their potential benefits and demonstrate their performance and reliability.

  6. Heat stroke and related heat stress disorders.

    Science.gov (United States)

    Knochel, J P

    1989-05-01

    Medical disorders related to environmental heat exposure are exceptionally common in persons who perform hard work in hot climates. They are also common in competitive athletes as well as in persons who participate in casual exercise to maintain health. The important issue of salt and water disturbances consequent to heavy sweating in hot climates is discussed in detail as are mechanisms of potassium deficiency and its implications. The major forms of environmental heat illness including heat syncope, heat cramp, heat exhaustion, and heat stroke are presented in detail with relevant clinical examples. A discussion of the differential diagnosis of hyperthermia and rhabdomyolysis follows. Because of the difference in treatment and complications, heat stroke is subdivided into the classic variety that affects the elderly and very young and that form that follows heavy physical work and is always associated with rhabdomyolysis. Because severe heat exhaustion and heat stroke are life-threatening disorders, the chapter includes a detailed discussion of complications and plans for treatment.

  7. Occurrence of temperature spikes at a wetting front during spontaneous imbibition.

    Science.gov (United States)

    Aslannejad, Hamed; Terzis, Alexandros; Hassanizadeh, S Majid; Weigand, Bernhard

    2017-08-04

    It is reported that temperature rises at wetting front during water infiltration into soil. The temperature goes back to the background value after passage of water front. Different explanations have been provided for source of energy causing temperature spike. Some have contributed it to heat of condensation released due to condensation of vapor on "dry" solid surface. Some other stated that the heat of wetting or heat of adsorption is responsible for the temperature rise. In this research, we revisited this issue. First, we provide a comprehensive review about occurrence of temperature spike at a wetting front. Then, we report about experiments we performed on the rise of water in dry paper. Using infrared and optical imaging techniques, we could monitor temperature changes in time and space. For all samples maximum temperature rise occurred at the wetting front. The magnitude of temperature spike depended on paper material, thickness, and liquid composition. It was larger for cellulose-fiber-based paper than for plastic-based paper. For a given paper type, thicker samples showed a larger temperature spike. Adding salt to the water caused reduction of temperature spike. It was concluded that replacement of air-solid interface with water-solid interface releases energy, which causes temperature rise.

  8. Heat Islands

    Science.gov (United States)

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

  9. Heat Waves

    Science.gov (United States)

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

  10. A simple and robust method for pre-wetting poly (lactic-co-glycolic) acid microspheres.

    Science.gov (United States)

    Wright, Bernice; Parmar, Nina; Bozec, Laurent; Aguayo, Sebastian D; Day, Richard M

    2015-08-01

    Poly (lactic-co-glycolic) acid microspheres are amenable to a number of biomedical procedures that support delivery of cells, drugs, peptides or genes. Hydrophilisation or wetting of poly (lactic-co-glycolic) acid are an important pre-requisites for attachment of cells and can be achieved via exposure to plasma oxygen or nitrogen, surface hydrolysis with NaOH or chloric acid, immersion in ethanol and water, or prolonged incubation in phosphate buffered saline or cell culture medium. The aim of this study is to develop a simple method for wetting poly (lactic-co-glycolic) acid microspheres for cell delivery applications. A one-step ethanol immersion process that involved addition of serum-supplemented medium and ethanol to PLGA microspheres over 30 min-24 h is described in the present study. This protocol presents a more efficient methodology than conventional two-step wetting procedures. Attachment of human skeletal myoblasts to poly (lactic-co-glycolic) acid microspheres was dependent on extent of wetting, changes in surface topography mediated by ethanol pre-wetting and serum protein adsorption. Ethanol, at 70% (v/v) and 100%, facilitated similar levels of wetting. Wetting with 35% (v/v) ethanol was only achieved after 24 h. Pre-wetting (over 3 h) with 70% (v/v) ethanol allowed significantly greater (p ≤ 0.01) serum protein adsorption to microspheres than wetting with 35% (v/v) ethanol. On serum protein-loaded microspheres, greater numbers of myoblasts attached to constructs wetted with 70% ethanol than those partially wetted with 35% (v/v) ethanol. Microspheres treated with 70% (v/v) ethanol presented a more rugose surface than those treated with 35% (v/v) ethanol, indicating that more efficient myoblast adhesion to the former may be at least partially attributed to differences in surface structure. We conclude that our novel protocol for pre-wetting poly (lactic-co-glycolic) acid microspheres that incorporates biochemical and structural features

  11. Aerodynamic heating of ballistic missile including the effects of gravity

    Indian Academy of Sciences (India)

    The aerodynamic heating of a ballistic missile due to only convection is analysed taking into consideration the effects of gravity. The amount of heat transferred to the wetted area and to the nose region has been separately determined, unlike A Miele's treatise without consideration of gravity. The peak heating ratesto the ...

  12. Aerodynamic heating of ballistic missile including the effects of gravity

    Indian Academy of Sciences (India)

    Abstract. The aerodynamic heating of a ballistic missile due to only convection is analysed taking into consideration the effects of gravity. The amount of heat transferred to the wetted area and to the nose region has been separately determined, unlike A Miele's treatise without consideration of gravity. The peak heating rates ...

  13. Learning immersion without getting wet

    Science.gov (United States)

    Aguilera, Julieta C.

    2012-03-01

    This paper describes the teaching of an immersive environments class on the Spring of 2011. The class had students from undergraduate as well as graduate art related majors. Their digital background and interests were also diverse. These variables were channeled as different approaches throughout the semester. Class components included fundamentals of stereoscopic computer graphics to explore spatial depth, 3D modeling and skeleton animation to in turn explore presence, exposure to formats like a stereo projection wall and dome environments to compare field of view across devices, and finally, interaction and tracking to explore issues of embodiment. All these components were supported by theoretical readings discussed in class. Guest artists presented their work in Virtual Reality, Dome Environments and other immersive formats. Museum professionals also introduced students to space science visualizations, which utilize immersive formats. Here I present the assignments and their outcome, together with insights as to how the creation of immersive environments can be learned through constraints that expose students to situations of embodied cognition.

  14. Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles.

    Directory of Open Access Journals (Sweden)

    Jens Vanselow

    Full Text Available High environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation. Eight German Holstein cows in established lactation were exposed to heat stress (28°C or thermoneutral conditions (15°C with pair-feeding for four days. After hormonal heat induction growth of the respective dominant follicles was monitored by ultrasonography for two days, then an ovulatory GnRH dose was given and follicular steroid hormones and granulosa cell-specific gene expression profiles were determined 23 hrs thereafter. The data showed that the pre-ovulatory growth of dominant follicles and the estradiol, but not the progesterone concentrations tended to be slightly affected. mRNA microarray and hierarchical cluster analysis revealed distinct expression profiles in granulosa cells derived from heat stressed compared to pair-fed animals. Among the 255 affected genes heatstress-, stress- or apoptosis associated genes were not present. But instead, we found up-regulation of genes essentially involved in G-protein coupled signaling pathways, extracellular matrix composition, and several members of the solute carrier family as well as up-regulation of FST encoding follistatin. In summary, the data of the present study show that acute pre-ovulatory heat stress can specifically alter gene expression profiles in granulosa cells, however without inducing stress related genes and pathways and suggestively can impair follicular growth due to affecting the activin-inhibin-follistatin system.

  15. Removal of atmospheric ethanol by wet deposition

    Science.gov (United States)

    Felix, J. David; Willey, Joan D.; Thomas, Rachel K.; Mullaugh, Katherine M.; Avery, G. Brooks; Kieber, Robert J.; Mead, Ralph N.; Helms, John; Giubbina, Fernanda F.; Campos, M. Lucia A. M.; Cala, John

    2017-02-01

    The global wet deposition flux of ethanol is estimated to be 2.4 ± 1.6 Tg/yr with a conservative range of 0.2-4.6 Tg/yr based upon analyses of 219 wet deposition samples collected at 12 locations globally. This estimate calculated by using observed wet deposition ethanol concentrations is in agreement with previous models (1.4-5 Tg/yr) predicting the wet deposition sink using Henry's law coefficients and atmospheric ethanol concentrations. Wet deposition is estimated to remove between 6 and 17% of the total ethanol emitted to the atmosphere on an annual basis. The concentration of ethanol in marine rain (25 ± 6 nM) is an order of magnitude less than in the majority of terrestrial rains (345 ± 280 nM). Terrestrial rain samples collected in locations impacted by high local sources of biofuel usage and locations downwind from ethanol distilleries were an order of magnitude higher in ethanol concentration (3090 ± 448 nM) compared to rain collected in terrestrial locations not impacted by these sources. These results indicate that wet deposition of ethanol is heavily influenced by local sources. Results of this study are important because they suggest that as biofuel production and usage increase, the concentration of ethanol in the atmosphere will increase as well the wet deposition flux. Additional research constraining the sources, sinks, and atmospheric impacts of ethanol is necessary to better assist in the debate as whether or not to increase consumption of the alcohol as a biofuel.

  16. Heat wave exposure in India in current, 1.5 °C, and 2.0 °C worlds

    Science.gov (United States)

    Mishra, Vimal; Mukherjee, Sourav; Kumar, Rohini; Stone, Dáithí A.

    2017-12-01

    Heatwaves with large impacts have increased in the recent past and will continue to increase under future warming. However, the implication for population exposure to severe heatwaves remains unexplored. Here, we characterize maximum potential human exposure (without passive/active reduction measures) to severe heatwaves in India. We show that if the global mean temperature is limited to 2.0 °C above pre-industrial conditions, the frequency of severe heatwaves will rise by 30 times the current climate by the end-21st century. In contrast, the frequency is projected to be about 2.5 times more (than the low-warming scenario of 2 °C) under conditions expected if the RCP8.5 ‘business-as-usual’ emissions scenario is followed. Under the 2.0 °C low-warming target, population exposure to severe heatwaves is projected to increase by about 15 and 92 times the current level by the mid and end-21st century respectively. Strategies to reduce population growth in India during the 21st century may provide only limited mitigation of heatwave exposure mostly late in the century. Limiting global temperatures to 1.5 °C above preindustrial would reduce the exposure by half relative to RCP8.5 by the mid-21st century. If global temperatures are to exceed 1.5 °C then substantial measures will be required to offset the large increase in exposure to severe heatwaves in India.

  17. Structure of wet specimens in electron microscopy. Improved environmental chambers make it possible to examine wet specimens easily.

    Science.gov (United States)

    Parsons, D F

    1974-11-01

    image intensifiers can bring the observation dose below that required to stop cell motility. Use of a timed, pulsed deflector system enables sufficiently short exposures to be obtained to eliminate blurring due to Brownian motion. Environmental chambers have enhanced the possibilities of electron diffraction analysis of minute crystals and ordered biological structures. High-resolution electron diffraction patterns (especially kinematic) of protein crystals can only be obtained in a wet environment. Hence, it may now be possible to obtain undistorted images of protein molecules. Moreover, by subjecting diffraction patterns to image-iterative techniques (56), it will be possible to phase the electron diffraction patterns to give a calculated image with a higher resolution than that which can be produced by electron microscope objective lenses. Environmental chambers offer exciting prospects for the determination of water structure and water and ice nucleation (atmospheric science). Nucleation data near the molecular level have been badly needed for some time. The application of environmental chambers in industrial chemistry, for example, in studies of polymerization, catalysis, and corrosion, are awaiting exploration. They offer an unusual approach to measurements of reaction kinetics through images that should be both sensitive and rapid.

  18. Effect of GSM-1800 and U.M.T.S. exposures on micro-glial activation and heat shock proteins induction in brain: a study on young adult and elderly rats

    Energy Technology Data Exchange (ETDEWEB)

    Laclau, M.; Billaudel, B.; Taxil, M.; Haro, E.; Ruffie, G.; Sanchez, S.; Poulletier De Gannes, F.; Lagroye, I.; Veyret, B. [PIOM/Bioelecromagnetics Lab., ENSCPB/EPHE, 33 - Pessac (France)

    2006-07-01

    Contradictory results have emerged from recent studies describing low -level radiofrequency radiation (R.F.R.) as a hazardous factor for the central nervous system while others described such type of exposure as totally safe. In the brain, heat shock proteins (H.s.p.) are often induced under harmful conditions such as ischemia, traumatic injury, epilepsy, hyperthermia, drug administration, and neuro-degenerative diseases. Under those conditions, activation of the micro-glial cell population is often observed. In this work we studied the effect of two types of mobile phone signals, GSM-1800 and U.M.T.S. on the expression of two major H.s.p., induced in the brain under harmful conditions, H.s.p. 70 and H.s.p. 25. We also studied micro-glial activation in young adult (8 weeks) and elderly (17 months) Wistar rats. Height animals by group were exposed. Exposures were performed using a brain-averaged S.A.R. of 2 W/kg following two types of protocols: an acute exposure, with exposure lasting only two hours, and a sub chronic exposure in which the animals were exposed for two hours per day, five days per week, during four weeks. In all cases, rats were progressively habituated to the exposure setup (rockets) over two weeks to avoid stress and a sham group was exposed for each condition. Positive controls were performed by induction of a status epilepticus using a subcutaneous injection kainic acid (10 mg/kg). At the end of exposure, rats were anesthetized with isofluran and perfused from the heart with P.B.S. then paraformaldehyde prior to removing of the brain. Sections (10 m m thick) were prepared on slides for immunohistochemistry. Brain samples were coded and the analysis was performed in a blind manner. The sections were immuno-histo-chemically stained with antibodies raised in rabbits against H.s.p.25 and against the inducible form of H.s.p.70. The whole glial cell population was detected by its common cell surface glyco conjugates, which bind the plant Griffonia

  19. Dust emission from wet, low-emission coke quenching process

    Science.gov (United States)

    Komosiński, Bogusław; Bobik, Bartłomiej; Konieczny, Tomasz; Cieślik, Ewelina

    2018-01-01

    Coke plants, which produce various types of coke (metallurgical, foundry or heating), at temperatures between 600 and 1200°C, with limited access to oxygen, are major emitters of particulates and gaseous pollutants to air, water and soils. Primarily, the process of wet quenching should be mentioned, as one of the most cumbersome. Atmospheric pollutants include particulates, tar substances, organic pollutants including B(a)P and many others. Pollutants are also formed from the decomposition of water used to quench coke (CO, phenol, HCN, H2S, NH3, cresol) and decomposition of hot coke in the first phase of quenching (CO, H2S, SO2) [1]. The development of the coke oven technology has resulted in the changes made to different types of technological installations, such as the use of baffles in quench towers, the removal of nitrogen oxides by selective NOx reduction, and the introduction of fabric filters for particulates removal. The BAT conclusions for coke plants [2] provide a methodology for the measurement of particulate emission from a wet, low-emission technology using Mohrhauer probes. The conclusions define the emission level for wet quenching process as 25 g/Mgcoke. The conducted research was aimed at verification of the presented method. For two of three quench towers (A and C) the requirements included in the BAT conclusions are not met and emissions amount to 87.34 and 61.35 g/Mgcoke respectively. The lowest particulates emission was recorded on the quench tower B and amounted to 22.5 g/Mgcoke, therefore not exceeding the requirements.

  20. Wetting and adsorption modification in the system

    Directory of Open Access Journals (Sweden)

    Yuliya Bogdanova

    2015-09-01

    Full Text Available Regularities of wetting and adsorption modification of surfaces of continual membranes made from highly permeable glassy polymers poly[1-(trimethylsilyl-1-propyne] (PTMSP and poly(4-methyl-2-pentyn (PMP with aqueous ethanol solutions and alcohol solutions containing organic dyes (Solvent Blue 35 and Remazol Brilliant Blue were investigated. Isotherms of stress wetting of polymer membrane surface by etanol solutions were found out to have maximums in the range of concentrations corresponding to the beginning of liquid sorption into the membrane and polymer swelling. Thus, the principal possibility of optimization of nanofiltration experiments by liquid wetting angle measurements on continuous polymer membrane surfaces was shown. The presence of the dye was shown not to affect PMP wetting. But in the case of PTMSP, it leads to shear of the maximum of stress wetting isotherms to the range of higher concentrations. It was found out the effectiveness of the adsorption surface modification of continuous polymer membrane surfaces by ethanol solutions containing dyes does not dependent on chemical nature of the dye. At the same time, there are different trends in the energy characteristics of the membrane surface.

  1. Membrane-based wet electrostatic precipitation.

    Science.gov (United States)

    Bayless, David J; Shi, Liming; Kremer, Gregory; Stuart, Ben J; Reynolds, James; Caine, John

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at FirstEnergy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with approximately 15% less collecting area.

  2. Dynamic wetting on anisotropic patterned surfaces

    Science.gov (United States)

    Do-Quang, Minh; Wang, Jiayu; Nita, Satoshi; Shiomi, Junichiro; Amberg, Gustav; Physiochemical fluid mechanics Team; Maruyama-Chiashi Laboratory Team

    2014-11-01

    Dynamic wetting, as occurs when a droplet of a wetting liquid is brought in contact with a dry solid, is important in various engineering processes, such as printing, coating, and lubrication. Our overall aim is to investigate if and how the detailed properties of the solid surface influence the dynamics of wetting. We have recently quantified the hindering effect of fairly isotropic micron-sized patterns on the substrate. Here we will study highly anisotropic surfaces, such as parallel grooves, either perpendicular or parallel to an advancing contact line. This is done by detailed phase field simulations and experiments on structured silicon surfaces. The dynamic wetting behavior of drops on the grooved surfaces is governed by the combined interplay of the wetting line friction and the internal viscous dissipation. Influence of roughness is quantified in terms of the energy dissipation rate at the contact line using the experiment-simulation combined analysis. The energy dissipation of the contact line at the different part of the groove will be discussed. The performance of the model is assessed by comparing its predictions with the experimental data. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W., S.N., and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A).

  3. The effect of high-flux H plasma exposure with simultaneous transient heat loads on tungsten surface damage and power handling

    NARCIS (Netherlands)

    van Eden, G. G.; Morgan, T. W.; van der Meiden, H. J.; J Matejicek,; T Chraska,; Wirtz, M.; De Temmerman, G.

    2014-01-01

    The performance of the full-W ITER divertor may be significantly affected by the interplay between steady-state plasma exposure and transient events. To address this issue, the effect of a high-flux H plasma on the thermal shock response of W to ELM-like transients has been investigated. Transient

  4. Sulfate-rich eolian and wet interdune deposits, erebus crater, meridiani Planum, Mars

    Science.gov (United States)

    Metz, J.M.; Grotzinger, J.P.; Rubin, D.M.; Lewis, K.W.; Squyres, S. W.; Bell, J.F.

    2009-01-01

    This study investigates three bedrock exposures at Erebus crater, an ?? 300 m diameter crater approximately 4 km south of Endurance crater on Mars. These outcrops, called Olympia, Payson, and Yavapai, provide additional evidence in support of the dune-interdune model proposed for the formation of the deposits at the Opportunity landing site in Meridiani Planum. There is evidence for greater involvement of liquid water in the Olympia outcrop exposures than was observed in Eagle or Endurance craters. The Olympia outcrop likely formed in a wet interdune and sand sheet environment. The facies observed within the Payson outcrop, which is likely stratigraphically above the Olympia outcrop, indicate that it was deposited in a damp-wet interdune, sand sheet, and eolian dune environment. The Yavapai outcrop, which likely stratigraphically overlies the Payson outcrop, indicates that it was deposited in primarily a sand sheet environment and also potentially in an eolian dune environment. These three outcrop exposures may indicate an overall drying-upward trend spanning the stratigraphic section from its base at the Olympia outcrop to its top at the Yavapai outcrop. This contrasts with the wetting-upward trend seen in Endurance and Eagle craters. Thus, the series of outcrops seen at Meridiani by Opportunity may constitute a full climatic cycle, evolving from dry to wet to dry conditions. ?? 2009, SEPM (Society for Sedimentary Geology).

  5. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

    1993-12-31

    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  6. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

  7. Development of a plasma assisted ITER level controlled heat source and observation of novel micro/nanostructures produced upon exposure of tungsten targets

    Energy Technology Data Exchange (ETDEWEB)

    Aomoa, N.; Sarmah, Trinayan; Sah, Puspalata [CIMPLE-PSI Laboratory, Centre of Plasma Physics-Institute for Plasma Research, Sonapur 782 402 Assam (India); Chaudhuri, P.; Khirwarker, S.; Ghosh, J. [Institute for Plasma Research, Gandhinagar 382428 Gujarat (India); Satpati, B. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Kakati, M., E-mail: mayurkak@rediffmail.com [CIMPLE-PSI Laboratory, Centre of Plasma Physics-Institute for Plasma Research, Sonapur 782 402 Assam (India); De Temmerman, G. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046 Saint Paul Lez Durance, Cedex (France)

    2016-05-15

    Highlights: • Developed a plasma assisted ITER level high heat flux device for material testing. • The beam deposits over 10 MW/m{sup 2} flux uniformly over a remote material target. • Hopper micro-crystals were growing while exposing Plansee tungsten in the device. • CIMPLE-PSI being developed for exact reproduction of Tokomak Divertor conditions. - Abstract: This paper reports on the development of a simple, low-cost, segmented plasma torch assisted high-heat flux device for material testing, which can simulate the extreme heat flux expected in future fusion devices. Calorimetric measurements confirmed uniform heat deposition by the well collimated argon plasma beam over a target surface with power fluxes in excess of 10 MW/m{sup 2} during high current, high gas flow rate operations. To understand the outcome of possible melting of first wall material in an ITER like machine, an Plansee tungsten target was exposed in this device, which witnessed growth of micrometer level Hopper crystals and their aggregation to vertical grains in central exposed region. Increase in viscosity of the metal during high under-cooling is believed to have lead to the skeletal patterns, observed for the first time for tungsten here. Transmission electron microscopy confirmed that re-solidified grains on the target actually had crystalline substructures in the nanometer level. This laboratory is in the process of developing an exact linear Tokamak Divertor simulator, where a magnetized hydrogen/helium collimated plasma jet will be produced at higher vacuum, for plasma material interaction studies with direct relevance to modern plasma fusion machines.

  8. Thermal wet decomposition of Prussian Blue: implications for prebiotic chemistry.

    Science.gov (United States)

    Ruiz-Bermejo, Marta; Rogero, Celia; Menor-Salván, César; Osuna-Esteban, Susana; Martín-Gago, José Angel; Veintemillas-Verdaguer, Sabino

    2009-09-01

    The complex salt named Prussian Blue, Fe4[Fe(CN)6]3 x 15 H2O, can release cyanide at pH > 10. From the point of view of the origin of life, this fact is of interest, since the oligomers of HCN, formed in the presence of ammonium or amines, leads to a variety of biomolecules. In this work, for the first time, the thermal wet decomposition of Prussian Blue was studied. To establish the influence of temperature and reaction time on the ability of Prussian Blue to release cyanide and to subsequently generate other compounds, suspensions of Prussian Blue were heated at temperatures from room temperature to 150 degrees at pH 12 in NH3 environment for several days. The NH3 wet decomposition of Prussian Blue generated hematite, alpha-Fe2O3, the soluble complex salt (NH4)4[Fe(CN6)] x 1.5 H2O, and several organic compounds, the nature and yield of which depend on the experimental conditions. Urea, lactic acid, 5,5-dimethylhydantoin, and several amino acids and carboxylic acids were identified by their trimethylsilyl (TMS) derivatives. HCN, cyanogen (C2N2), and formamide (HCONH2) were detected in the gas phase by GC/MS analysis.

  9. Predictive modeling of reactive wetting and metal joining.

    Energy Technology Data Exchange (ETDEWEB)

    van Swol, Frank B.

    2013-09-01

    The performance, reproducibility and reliability of metal joints are complex functions of the detailed history of physical processes involved in their creation. Prediction and control of these processes constitutes an intrinsically challenging multi-physics problem involving heating and melting a metal alloy and reactive wetting. Understanding this process requires coupling strong molecularscale chemistry at the interface with microscopic (diffusion) and macroscopic mass transport (flow) inside the liquid followed by subsequent cooling and solidification of the new metal mixture. The final joint displays compositional heterogeneity and its resulting microstructure largely determines the success or failure of the entire component. At present there exists no computational tool at Sandia that can predict the formation and success of a braze joint, as current capabilities lack the ability to capture surface/interface reactions and their effect on interface properties. This situation precludes us from implementing a proactive strategy to deal with joining problems. Here, we describe what is needed to arrive at a predictive modeling and simulation capability for multicomponent metals with complicated phase diagrams for melting and solidification, incorporating dissolutive and composition-dependent wetting.

  10. Effect of Sand Wetting on Physically Hardened Moulding Sands Containing a Selected Inorganic Binder. Part 1

    Directory of Open Access Journals (Sweden)

    Stachowicz M.

    2016-03-01

    Full Text Available In the paper, an attempt was made to evaluate the effect of preliminary wetting of high-silica base during preparation of moulding sands containing a selected grade of sodium water-glass, designed for hardening by traditional drying or by electromagnetic microwaves at 2.45 GHz. In the research, some water was dosed during stirring the sandmix before adding 1.5 wt% of the binder that was unmodified sodium water-glass grade 137, characterised by high molar module within 3.2 to 3.4. Scope of the examinations included determining the effect of wetting the base on mechanical parameters like compression, bending and tensile strength, as well as on technological parameters like permeability, abrasion resistance and apparent density. The research revealed a significant positive effect of adding water to wet surfaces of high-silica base grains on mechanical properties and quality of moulding sands hardened by physical methods, in particular by microwave heating.

  11. Simplified approach of predictions of thermal performance for counterflow fully-wet cooling coil

    Science.gov (United States)

    Mansour, M. Khamis; Hassab, M. A.

    2017-06-01

    An innovative correlation associating the effectiveness (ɛ) of the fully-wet cooling coil with its number of transfer unit and vice versa is presented in this work. The thermal performance and design of fully-wet cooling coil can be predicted simply through those correlations. The analytical model was constructed on a basis of solving heat and mass transfer equation "enthalpy potential method" simultaneously coupled with the energy equations. The validity of the new correlations was tested by experimental reported in the available literature. A good agreement with deviation less than 10% was found during the comparison between the output results of the new correlations and those obtained from the literature. The main benefits of those new correlations (1) Its simplicity to be implemented through simple calculations of input parameters (2) It provides helpful guidelines for optimization of wet cooling coil performance during its operation coupling with the thermal system at which the coil is integrated.

  12. Wet powder seal for gas containment

    Science.gov (United States)

    Stang, Louis G.

    1982-01-01

    A gas seal is formed by a compact layer of an insoluble powder and liquid filling the fine interstices of that layer. The smaller the particle size of the selected powder, such as sand or talc, the finer will be the interstices or capillary spaces in the layer and the greater will be the resulting sealing capacity, i.e., the gas pressure differential which the wet powder layer can withstand. Such wet powder seal is useful in constructing underground gas reservoirs or storage cavities for nuclear wastes as well as stopping leaks in gas mains buried under ground or situated under water. The sealing capacity of the wet powder seal can be augmented by the hydrostatic head of a liquid body established over the seal.

  13. Novel design for Konin wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Zawacki, T.; Bengtsson, S. [ZEPAK, Konin (Poland)

    1996-09-01

    The Konin Power Station, Poland, with a total production capacity of 538 MW{sub e} and 462 MW{sub th} and belonging to the ZEPAK group, is extensively rebuilding units Nos 7 and 8 and retrofitting with wet flue gas desulphurisation. ZEPAK evaluated wet FGD technologies in 1992 and 1993 and decided for a novel concrete absorber-in-stack concept for a limestone forced oxidation system, that will produce commercial grade gypsum. The FGD plant is now under construction and commissioning is scheduled to commence in first quarter of 1997. The paper will provide the background for the choice of wet FGD and present details on both execution and technology for this novel absorber-in-stack concept for power plant FGD.

  14. Parametric study of closed wet cooling tower thermal performance

    Science.gov (United States)

    Qasim, S. M.; Hayder, M. J.

    2017-08-01

    The present study involves experimental and theoretical analysis to evaluate the thermal performance of modified Closed Wet Cooling Tower (CWCT). The experimental study includes: design, manufacture and testing prototype of a modified counter flow forced draft CWCT. The modification based on addition packing to the conventional CWCT. A series of experiments was carried out at different operational parameters. In view of energy analysis, the thermal performance parameters of the tower are: cooling range, tower approach, cooling capacity, thermal efficiency, heat and mass transfer coefficients. The theoretical study included develops Artificial Neural Network (ANN) models to predicting various thermal performance parameters of the tower. Utilizing experimental data for training and testing, the models simulated by multi-layer back propagation algorithm for varying all operational parameters stated in experimental test.

  15. Heat stress and inadequate sanitary facilities at workplaces – an occupational health concern for women?

    Directory of Open Access Journals (Sweden)

    Vidhya Venugopal

    2016-09-01

    Full Text Available Background: Health concerns unique to women are growing with the large number of women venturing into different trades that expose them to hot working environments and inadequate sanitation facilities, common in many Indian workplaces. Objective: The study was carried out to investigate the health implications of exposures to hot work environments and inadequate sanitation facilities at their workplaces for women workers. Design: A cross-sectional study was conducted with 312 women workers in three occupational sectors in 2014–2015. Quantitative data on heat exposures and physiological heat strain indicators such as core body temperature (CBT, sweat rate (SwR, and urine specific gravity (USG were collected. A structured questionnaire captured workers perceptions about health impacts of heat stress and inadequate sanitary facilities at the workplace. Results: Workplace heat exposures exceeded the threshold limit value for safe manual work for 71% women (Avg. wet bulb globe temperature=30°C±2.3°C during the study period. Eighty-seven percent of the 200 women who had inadequate/no toilets at their workplaces reported experiencing genitourinary problems periodically. Above normal CBT, SwR, and USG in about 10% women workers indicated heat strain and moderate dehydration that corroborated well with their perceptions. Observed significant associations between high-heat exposures and SwR (t=−2.3879, p=0.0192, inadequate toilet facilities and self-reported adverse heat-related health symptoms (χ2=4.03, p=0.0444, and prevalence of genitourinary issues (χ2=42.92, p=0.0005×10−7 reemphasize that heat is a risk and lack of sanitation facilities is a major health concern for women workers. Conclusions: The preliminary evidence suggests that health of women workers is at risk due to occupational heat exposures and inadequate sanitation facilities at many Indian workplaces. Intervention through strong labor policies with gender sensitivity is the

  16. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  17. Effect of heat exposure on the thermoregulatory responses of selected naked neck chickens Efeito da exposição ao calor na resposta termorregulatória de aves de pescoço pelado selecionadas

    Directory of Open Access Journals (Sweden)

    C.M. Mazzi

    2002-02-01

    Full Text Available The variation in cloacal temperature, body weight loss and expression of the 70 kDa heat shock protein (Hsp70 in three naked neck broiler genotypes during heat stress were studied. Twelve birds of each genotype (Na/Na, Na/na and na/na were reared to market weight (approximately 2.1kg at thermoneutral temperature. Six birds from each group served as controls and the remaining six underwent gradual heat stress (from 28ºC to 36ºC. Cloacal temperature and body weight were measured before and after exposure to heat. Liver samples were collected and Hsp70 levels were quantified using western blotting with monoclonal anti-chicken Hsp70 antibody. Heterozygous (Na/na birds had a significantly lower cloacal temperature variation and less body weight loss during heat stress than the other genotypes. There was no significant difference in the Hsp70 levels among the genotypes. Heterozygous birds (Na/na appeared to have a slight advantage over the other genotypes during gradual heat stress, perhaps because of a heterotic effect.Estudaram-se o efeito do estresse térmico sobre a temperatura cloacal, a perda de peso corporal e a expressão da proteína de estresse de 70 kDa (Hsp70 em três genótipos de galinhas de pescoço-pelado. Foram usadas 12 aves de cada genótipo (Na/Na, Na/na e na/na, com peso corporal médio de 2,100kg e criadas em temperatura termoneutra. Seis aves de cada grupo serviram como controle e as seis restantes foram submetidas a estresse térmico gradativo (28ºC - 36ºC. A temperatura cloacal e o peso das aves foram avaliados antes e depois do estresse. Amostras de fígado foram coletadas e os níveis de Hsp70 foram quantificados por "western blotting" com anticorpo monoclonal específico para Hsp70 de galinha. As aves heterozigotas (Na/na tiveram variação de temperatura cloacal significativamente menor e menor perda de peso corporal durante o estresse térmico do que as dos outros genótipos. Não foi observada diferen

  18. Hydrazide-Derivatized Microgels Bond to Wet, Oxidized Cellulose Giving Adhesion Without Drying or Curing.

    Science.gov (United States)

    Yang, Dong; Gustafsson, Emil; Stimpson, Taylor C; Esser, Anton; Pelton, Robert H

    2017-06-21

    Hydrazide-derivatized poly(N-isopropylacrylamide-co-acrylic acid) microgels gave strong adhesion to wet, TEMPO oxidized, regenerated cellulose membranes without a drying or heating step. Adhesion was attributed to hydrazone covalent bond formation with aldehyde groups present on the cellulose surfaces. This is one of only three chemistries we have found that gives significant never-dried adhesion between wet cellulose surfaces. By contrast, for cellulose joints that have been dried and heated before wet testing, the hydrazide-hydrazone chemistry offers no advantages over standard paper industry wet strength resins. The design rules for the hydrazide-microgel adhesives include: cationic microgels are superior to anionic gels; the lower the microgel cross-link density, the higher the adhesion; longer PEG-based hydrazide tethers offer no advantage over shorter attachments; and, adhesion is independent of microgel diameter. Many of these rules were in agreement with predictions of a simple adhesion model where the microgels were assumed to be ideal springs. We propose that the unexpected, high cohesion between neighboring microgels in multilayer films was a result of bond formation between hydrazide groups and residual NHS-carboxyl esters from the preparation of the hydrazide microgels.

  19. Water-induced finger wrinkles do not affect touch acuity or dexterity in handling wet objects.

    Directory of Open Access Journals (Sweden)

    Julia Haseleu

    Full Text Available Human non-hairy (glabrous skin of the fingers, palms and soles wrinkles after prolonged exposure to water. Wrinkling is a sympathetic nervous system-dependent process but little is known about the physiology and potential functions of water-induced skin wrinkling. Here we investigated the idea that wrinkling might improve handling of wet objects by measuring the performance of a large cohort of human subjects (n = 40 in a manual dexterity task. We also tested the idea that skin wrinkling has an impact on tactile acuity or vibrotactile sensation using two independent sensory tasks. We found that skin wrinkling did not improve dexterity in handling wet objects nor did it affect any aspect of touch sensitivity measured. Thus water-induced wrinkling appears to have no significant impact on tactile driven performance or dexterity in handling wet or dry objects.

  20. Water-induced finger wrinkles do not affect touch acuity or dexterity in handling wet objects.

    Science.gov (United States)

    Haseleu, Julia; Omerbašić, Damir; Frenzel, Henning; Gross, Manfred; Lewin, Gary R

    2014-01-01

    Human non-hairy (glabrous) skin of the fingers, palms and soles wrinkles after prolonged exposure to water. Wrinkling is a sympathetic nervous system-dependent process but little is known about the physiology and potential functions of water-induced skin wrinkling. Here we investigated the idea that wrinkling might improve handling of wet objects by measuring the performance of a large cohort of human subjects (n = 40) in a manual dexterity task. We also tested the idea that skin wrinkling has an impact on tactile acuity or vibrotactile sensation using two independent sensory tasks. We found that skin wrinkling did not improve dexterity in handling wet objects nor did it affect any aspect of touch sensitivity measured. Thus water-induced wrinkling appears to have no significant impact on tactile driven performance or dexterity in handling wet or dry objects.

  1. Wetting properties and performance test of modified rigid collector in wet electrostatic precipitators.

    Science.gov (United States)

    Xu, Chunyan; Chang, Jingcai; Meng, Zhen; Wang, Xiang; Zhang, Jing; Cui, Lin; Ma, Chunyuan

    2016-10-01

    The fine particles are considered a significant pollution problem. The wet electrostatic precipitators (ESPs) have advantages of efficient collection of the fine particles with lower pressure drop and eliminating reentrainment. The wetting properties of the collector surfaces have significantly important effect on wet ESPs' stable and secure operation. The modified rigid collector (MRC) was modified by coating specific vinyl ester resin composites and loose glass fiber cloth over the conventional carbon steel in a certain way. The rigid collector surfaces before and after modification had been characterized by scanning electron microscopy (SEM) and interface tensiometer. The effect of operating temperatures on the wetting properties of the rigid collector surfaces before and after modification was investigated. The temperature range was 40~90 °C, and the wetting properties contained liquid holdup, surface flow rate, film rate, average film thickness, and critical saturation time. The modified rigid collector surface exhibited excellent wetting properties at the operating temperatures. The fine particles collection performance compared among the MRC, the conventional rigid collector (CRC), and the flexible collector (FC) in the wet ESPs was investigated. The effects of the applied voltage, the water film, corona power, and the specific collecting area on the fine particles collection were evaluated. The modified rigid collector provided high fine particles collection effect with lower energy and water consumption. To improve the submicron particles collection efficiency and decrease energy and water consumption, the formation of uniform water film over the collector surfaces has been widely studied. The modified rigid collector was modified by coating specific vinyl ester resin composites and loose glass fiber cloth (ERGF) over the conventional carbon steel (CCS) in a certain way. The modified rigid collector surface exhibited excellent wetting properties. The wet

  2. Catalytic gasification of dry and wet biomass

    NARCIS (Netherlands)

    van Rossum, G.; Potic, B.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2009-01-01

    Catalytic gasification of dry biomass and of wet biomass streams in hot compressed water are reviewed and discussed as potential technologies for the production of synthesis gas, hydrogen- and methane-rich gas. Next to literature data also new experimental results from our laboratory on catalytic

  3. Wet oxidation of salicylic acid solutions.

    Science.gov (United States)

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  4. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.

    1995-01-01

    layer lW, leading to a power law lW∝r01/3. At a critical wetting transition of a planar substrate, curvature adds a relevant field; the corresponding multiscaling forms are readily available. The method allows for the systematic evaluation of corrections to the leading behavior; the next to the leading...

  5. Theory of the forced wetting transition

    NARCIS (Netherlands)

    Chan, Tak Shing; Snoeijer, Jacobus Hendrikus; Eggers, J.

    2012-01-01

    We consider a solid plate being withdrawn from a bath of liquid which it does not wet. At low speeds, the meniscus rises below a moving contact line, leaving the rest of the plate dry. At a critical speed of withdrawal, this solution bifurcates into another branch via a saddle-node bifurcation: two

  6. Directional wetting on chemically patterned substrates

    NARCIS (Netherlands)

    Kooij, Ernst S.; Jansen, H.P.; Bliznyuk, O.; Poelsema, Bene; Zandvliet, Henricus J.W.

    2012-01-01

    The directional wetting behavior of chemically defined stripe-patterned anisotropic surfaces is presented. The equilibrium shapes of asymmetric droplets, arising from patterns of alternating hydrophilic and hydrophobic stripes with dimensions in the low-micrometer range, are investigated in relation

  7. Accretion Dynamics on Wet Granular Materials

    Science.gov (United States)

    Saingier, Guillaume; Sauret, Alban; Jop, Pierre

    2017-05-01

    Wet granular aggregates are common precursors of construction materials, food, and health care products. The physical mechanisms involved in the mixing of dry grains with a wet substrate are not well understood and difficult to control. Here, we study experimentally the accretion of dry grains on a wet granular substrate by measuring the growth dynamics of the wet aggregate. We show that this aggregate is fully saturated and its cohesion is ensured by the capillary depression at the air-liquid interface. The growth dynamics is controlled by the liquid fraction at the surface of the aggregate and exhibits two regimes. In the viscous regime, the growth dynamics is limited by the capillary-driven flow of liquid through the granular packing to the surface of the aggregate. In the capture regime, the capture probability depends on the availability of the liquid at the saturated interface, which is controlled by the hydrostatic depression in the material. We propose a model that rationalizes our observations and captures both dynamics based on the evolution of the capture probability with the hydrostatic depression.

  8. Cohesion and agglomeration of wet powders

    Science.gov (United States)

    Raux, Pascal S.; Biance, Anne-Laure

    2018-01-01

    Wet high-shear granulation consists in vigorously mixing grains and a liquid binder to create agglomerates of various sizes. The process results from a balance between cohesion of the wet granular agglomerates and fragmentation due to the high mixing. By performing a simple test with glass beads and various liquids, we first focus on the static cohesion of wet granular media. Contrary to previous works, we extend the study to larger values of the liquid fraction w . After the well-documented plateau, the cohesive strength increases again with w , a behavior we capture by a simple model. We then focus on the dynamical cohesion of the media and we design an agglomeration process that consists in vibrating a bead/liquid mixture at a large amplitude. The vibrations induce not only the fluidization of the wet granular material but also the formation of aggregates. As expected, their size is affected by the liquid content, the frequency, and the amplitude of the vibrations, similarly to high-shear granulation data. However, the number of beads in an agglomerate does not depend on the bead size, showing a self-similar mechanism of agglomeration. The role of the static cohesion strength in this dynamical process remains therefore ambiguous.

  9. Microwave moisture sensing of wet bales

    Science.gov (United States)

    Sensing of moisture in very wet lint bales is unique due to the fact that moisture distribution is typically non-uniform and can in some instances be highly localized. This issue is even further complicated by the use of a sensor that reads only a portion of the bale and/or with a sensor that provid...

  10. Ovine wet carcass syndrome of unknown aetiology

    African Journals Online (AJOL)

    plicating cachexia, inflammatory processes, lymphoedema, cardiac failure, glycogen storage or myxoedema in the pathogenesis of the syndrome. In conclusion, despite intensive investigation the aeti- ology of the wet carcase syndrome remains unknown. At present the possibility of a histamine reaction due to insect bites is ...

  11. Climate Change and the Emergent Epidemic of CKD from Heat Stress in Rural Communities: The Case for Heat Stress Nephropathy

    National Research Council Canada - National Science Library

    Glaser, Jason; Lemery, Jay; Rajagopalan, Balaji; Diaz, Henry F; García-Trabanino, Ramón; Taduri, Gangadhar; Madero, Magdalena; Amarasinghe, Mala; Abraham, Georgi; Anutrakulchai, Sirirat; Jha, Vivekanand; Stenvinkel, Peter; Roncal-Jimenez, Carlos; Lanaspa, Miguel A; Correa-Rotter, Ricardo; Sheikh-Hamad, David; Burdmann, Emmanuel A; Andres-Hernando, Ana; Milagres, Tamara; Weiss, Ilana; Kanbay, Mehmet; Wesseling, Catharina; Sánchez-Lozada, Laura Gabriela; Johnson, Richard J

    2016-01-01

    ... as from outright heat exhaustion and heat stroke. Recent studies have also shown that recurrent heat exposure with physical exertion and inadequate hydration can lead to CKD that is distinct from that caused by diabetes, hypertension, or GN...

  12. Black silicon with self-cleaning surface prepared by wetting processes

    OpenAIRE

    Zhang, Ting; Zhang, Peng; Li, Shibin; Li, Wei; Wu, Zhiming; Jiang, Yadong

    2013-01-01

    This paper reports on a simple method to prepare a hydrophobic surface on black silicon, which is fabricated by metal-assisted wet etching. To increase the reaction rate, the reaction device was placed in a heat collection-constant temperature type magnetic stirrer and set at room temperature. It was demonstrated that the micro- and nanoscale spikes on the black silicon made the surface become hydrophobic. As the reaction rate increases, the surface hydrophobicity becomes more outstanding and...

  13. User's manual for the BNW-II optimization code for dry/wet-cooled power plants

    Energy Technology Data Exchange (ETDEWEB)

    Braun, D.J.; Bamberger, J.A.; Braun, D.J.; Faletti, D.W.; Wiles, L.E.

    1978-05-01

    The User's Manual describes how to operate BNW-II, a computer code developed by the Pacific Northwest Laboratory (PNL) as a part of its activities under the Department of Energy (DOE) Dry Cooling Enhancement Program. The computer program offers a comprehensive method of evaluating the cost savings potential of dry/wet-cooled heat rejection systems. Going beyond simple ''figure-of-merit'' cooling tower optimization, this method includes such items as the cost of annual replacement capacity, and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence the BNW-II code is a useful tool for determining potential cost savings of new dry/wet surfaces, new piping, or other components as part of an optimized system for a dry/wet-cooled plant.

  14. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Directory of Open Access Journals (Sweden)

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  15. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Science.gov (United States)

    Shirtcliffe, Neil J; McHale, Glen; Newton, Michael I

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  16. Cryogenic thermal diode heat pipes

    Science.gov (United States)

    Alario, J.

    1979-01-01

    The development of spiral artery cryogenic thermal diode heat pipes was continued. Ethane was the working fluid and stainless steel the heat pipe material in all cases. The major tasks included: (1) building a liquid blockage (blocking orifice) thermal diode suitable for the HEPP space flight experiment; (2) building a liquid trap thermal diode engineering model; (3) retesting the original liquid blockage engineering model, and (4) investigating the startup dynamics of artery cryogenic thermal diodes. An experimental investigation was also conducted into the wetting characteristics of ethane/stainless steel systems using a specially constructed chamber that permitted in situ observations.

  17. User's manual for the BNW-II optimization code for dry/wet-cooled power plants

    Energy Technology Data Exchange (ETDEWEB)

    Braun, D.J.; Bamberger, J.A.; Braun, D.J.; Faletti, D.W.; Wiles, L.E.

    1978-05-01

    This volume provides a listing of the BNW-II dry/wet ammonia heat rejection optimization code and is an appendix to Volume I which gives a narrative description of the code's algorithms as well as logic, input and output information.

  18. A randomised, controlled, two-Centre open-label study in healthy Japanese subjects to evaluate the effect on biomarkers of exposure of switching from a conventional cigarette to a tobacco heating product.

    Science.gov (United States)

    Gale, Nathan; McEwan, Mike; Eldridge, Alison C; Sherwood, Neil; Bowen, Edward; McDermott, Simon; Holmes, Emma; Hedge, Andrew; Hossack, Stuart; Camacho, Oscar M; Errington, Graham; McAughey, John; Murphy, James; Liu, Chuan; Proctor, Christopher J; Fearon, Ian M

    2017-08-22

    Smoking is a leading cause of numerous human disorders including lung cancer, chronic obstructive pulmonary disease, and atherosclerotic cardiovascular disease. The development of modified risk tobacco products (MRTPs) has been suggested as a possible way to reduce the risks of tobacco smoking by reducing exposure to cigarette smoke toxicants. This study is designed to investigate whether biomarkers of such exposure are reduced when smokers switch from smoking commercial cigarettes to using either a novel or a commercially-available tobacco heating product (THP). This study will assess biomarkers of exposure in current smokers who either remain smoking, switch to THP use, or quit all tobacco use completely, for 5 days. The study is an in-clinic (confinement) two-centre, randomised controlled clinical study with a forced-switching design. Subjects of either gender will be aged 23-55 years (minimum legal smoking age plus 3 years), of Japanese origin and with a verified smoking status (assessed by exhaled breath carbon monoxide and urinary cotinine levels). Subjects will have a usual brand cigarette within the International Organisation for Standardisation (ISO) tar band of 6-8 mg and will be judged to be healthy by medical history, physical examination, vital signs, electrocardiography (ECG), clinical biochemistry and lung function tests. The primary objective of this study is to assess changes within groups in selected biomarkers of exposure (BoE) and of biological effect (BoBE) after a forced switch from a commercial control cigarette to either a menthol or a non-menthol THP. Secondary objectives are to assess between-group differences, to determine nicotine pharmacokinetics for cigarettes and THPs, to assess subject's satisfaction with the study products, and to monitor additional endpoints related to safety and product use. Data from this study will advance our scientific understanding of the changes in exposure to cigarette smoke toxicants in smokers who

  19. A randomised, controlled, two-Centre open-label study in healthy Japanese subjects to evaluate the effect on biomarkers of exposure of switching from a conventional cigarette to a tobacco heating product

    Directory of Open Access Journals (Sweden)

    Nathan Gale

    2017-08-01

    Full Text Available Abstract Background Smoking is a leading cause of numerous human disorders including lung cancer, chronic obstructive pulmonary disease, and atherosclerotic cardiovascular disease. The development of modified risk tobacco products (MRTPs has been suggested as a possible way to reduce the risks of tobacco smoking by reducing exposure to cigarette smoke toxicants. This study is designed to investigate whether biomarkers of such exposure are reduced when smokers switch from smoking commercial cigarettes to using either a novel or a commercially-available tobacco heating product (THP. Design and Methods This study will assess biomarkers of exposure in current smokers who either remain smoking, switch to THP use, or quit all tobacco use completely, for 5 days. The study is an in-clinic (confinement two-centre, randomised controlled clinical study with a forced-switching design. Subjects of either gender will be aged 23–55 years (minimum legal smoking age plus 3 years, of Japanese origin and with a verified smoking status (assessed by exhaled breath carbon monoxide and urinary cotinine levels. Subjects will have a usual brand cigarette within the International Organisation for Standardisation (ISO tar band of 6-8 mg and will be judged to be healthy by medical history, physical examination, vital signs, electrocardiography (ECG, clinical biochemistry and lung function tests. The primary objective of this study is to assess changes within groups in selected biomarkers of exposure (BoE and of biological effect (BoBE after a forced switch from a commercial control cigarette to either a menthol or a non-menthol THP. Secondary objectives are to assess between-group differences, to determine nicotine pharmacokinetics for cigarettes and THPs, to assess subject’s satisfaction with the study products, and to monitor additional endpoints related to safety and product use. Discussion Data from this study will advance our scientific understanding of the

  20. Heat pumps

    CERN Document Server

    Macmichael, DBA

    1988-01-01

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

  1. Evaluation of the Tobacco Heating System 2.2. Part 6: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects of a mentholated version compared with mentholated and non-mentholated cigarette smoke.

    Science.gov (United States)

    Oviedo, Alberto; Lebrun, Stefan; Kogel, Ulrike; Ho, Jenny; Tan, Wei Teck; Titz, Bjoern; Leroy, Patrice; Vuillaume, Gregory; Bera, Monali; Martin, Florian; Rodrigo, Gregory; Esposito, Marco; Dempsey, Ruth; Ivanov, Nikolai V; Hoeng, Julia; Peitsch, Manuel C; Vanscheeuwijck, Patrick

    2016-11-30

    The toxicity of a mentholated version of the Tobacco Heating System (THS2.2M), a candidate modified risk tobacco product (MRTP), was characterized in a 90-day OECD inhalation study. Differential gene and protein expression analysis of nasal epithelium and lung tissue was also performed to record exposure effects at the molecular level. Rats were exposed to filtered air (sham), to THS2.2M (at 15, 23 and 50 μg nicotine/l), to two mentholated reference cigarettes (MRC) (at 23 μg nicotine/l), or to the 3R4F reference cigarette (at 23 μg nicotine/l). MRCs were designed to meet 3R4F specifications. Test atmosphere analyses demonstrated that aldehydes were reduced by 75%-90% and carbon monoxide by 98% in THS2.2M aerosol compared with MRC smoke; aerosol uptake was confirmed by carboxyhemoglobin and menthol concentrations in blood, and by the quantities of urinary nicotine metabolites. Systemic toxicity and alterations in the respiratory tract were significantly lower in THS2.2M-exposed rats compared with MRC and 3R4F. Pulmonary inflammation and the magnitude of the changes in gene and protein expression were also dramatically lower after THS2.2M exposure compared with MRCs and 3R4F. No menthol-related effects were observed after MRC mainstream smoke-exposure compared with 3R4F. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Evaluation of the Tobacco Heating System 2.2. Part 4: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects compared with cigarette smoke.

    Science.gov (United States)

    Wong, Ee Tsin; Kogel, Ulrike; Veljkovic, Emilija; Martin, Florian; Xiang, Yang; Boue, Stephanie; Vuillaume, Gregory; Leroy, Patrice; Guedj, Emmanuel; Rodrigo, Gregory; Ivanov, Nikolai V; Hoeng, Julia; Peitsch, Manuel C; Vanscheeuwijck, Patrick

    2016-11-30

    The objective of the study was to characterize the toxicity from sub-chronic inhalation of test atmospheres from the candidate modified risk tobacco product (MRTP), Tobacco Heating System version 2.2 (THS2.2), and to compare it with that of the 3R4F reference cigarette. A 90-day nose-only inhalation study on Sprague-Dawley rats was performed, combining classical and systems toxicology approaches. Reduction in respiratory minute volume, degree of lung inflammation, and histopathological findings in the respiratory tract organs were significantly less pronounced in THS2.2-exposed groups compared with 3R4F-exposed groups. Transcriptomics data obtained from nasal epithelium and lung parenchyma showed concentration-dependent differential gene expression following 3R4F exposure that was less pronounced in the THS2.2-exposed groups. Molecular network analysis showed that inflammatory processes were the most affected by 3R4F, while the extent of THS2.2 impact was much lower. Most other toxicological endpoints evaluated did not show exposure-related effects. Where findings were observed, the effects were similar in 3R4F- and THS2.2-exposed animals. In summary, toxicological changes observed in the respiratory tract organs of THS2.2 aerosol-exposed rats were much less pronounced than in 3R4F-exposed rats while other toxicological endpoints either showed no exposure-related effects or were comparable to what was observed in the 3R4F-exposed rats. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Critical Casimir forces and anomalous wetting

    Indian Academy of Sciences (India)

    Laboratoire de Physique Statistique de l´Ecole Normale Supérieure, associé au CNRS et aux Universités Paris 6 et 7, 24 rue Lhomond, 75231 Paris Cedex 05, France. E-mail: balibar@lps.ens.fr. Abstract. We present a review of critical Casimir forces in connection with successive experiments on wetting near the critical ...

  4. Making Activated Carbon by Wet Pressurized Pyrolysis

    Science.gov (United States)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

    2006-01-01

    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  5. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    comparable to the RHS of figure 1. The averaging yields ψav(z, t) ≃ ψ0 = 0 in the bulk, where the phase-separation profiles are randomly oriented. However, a systematic behavior is seen at the surface. The wetting profiles are characterized by the zero-crossings of ψav(z, t) − ψ0. We denote the first and second zeros as.

  6. Wet flue gas desulphurization and new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kiil, S.; Dam-Johansen, K.; Michelsen, M.L.

    1998-04-01

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurization (FGD). A review of the current knowledge of the various rate determining steps in wet FDG plants is presented. The mechanism underlying the rate of dissolution of finely grained limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish limestones of different origin were tested. A transient, mass transport controlled, mathematical model was developed to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling-film column) were determined. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15%, though the effect could not be correlated. A detailed model for a wet FGD pilot plant, based on the falling film principle, was developed. All important rate determining steps, absorption of SO{sub 2}, oxidation of HSO{sub 3}{sup -}, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO{sub 2}, slurry pH-profiles, solids contents of slurry, liquid phase concentrations, and residual limestone in the gypsum. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No effects on the overall performance of the wet FGD plant were observed, though laboratory experiments with fine dust and fly ash from the full-scale experiments showed a decrease in limestone reactivity. (EG) EFP-95. 45 refs.; Also ph.d. thesis of Soeren Kiil

  7. Study of polycaprolactone wet electrospinning process

    Directory of Open Access Journals (Sweden)

    E. Kostakova

    2014-08-01

    Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

  8. Bioinspired Dynamic Wetting on Multiple Fibers.

    Science.gov (United States)

    Wang, Pengwei; Bian, Ruixin; Meng, Qing'an; Liu, Huan; Jiang, Lei

    2017-10-12

    Natural fibers have versatile strategies for interacting with water media and better adapting to the local environment, and these strategies offer inspiration for the development of artificial functional fibers with diverse applications. Wetting on fibers is a dynamic liquid-moving process on/in fibrous systems with various patterns, and the process is normally driven by the structural gradient, chemical gradient, elasticity of a single fiber, or the synergistic effect of these factors in multiple fibers in an integrated system in which the spatial geometry of the fibers is involved. Compared with the directional liquid movement on a single fiber, wetting on multiple fibers in both the micro- and macroscales is particularly fascinating, with various performances, including directional liquid transport, controllable liquid transfer, efficient liquid encapsulation, and capillary-induced fibrous coalescence. Based on these properties, fibrous materials offer an alternative open system for liquid manipulation that is applicable to various functional liquid materials. Here, recent achievements in bioinspired dynamic wetting on multiple fibers are highlighted, and perspectives on future directions are presented. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Cost estimation for advanced wet MOX plant

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Masahito; Kojima, Hisao [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1997-12-01

    PNC proposes a design concept of an advanced wet MOX plant based on low-level decontamination reprocessing plant and a simple fuel fabrication method. It significantly changes the boundary condition for design of reprocessing, fuel fabrication and reactor to alter the wet MOX cycle into a convenient form as simple as that of metal fuel cycle. According to the concept, the reprocessing process is substantially simplified by holding the decontamination level low, so that both reprocessing and fabrication processes can be installed in a single facility utilizing common utilities including a liquid waste processing facility. This report summarizes the results of the conceptual design of the plant and cost evaluation. Construction costs were estimated for the current plant constructed by means of the current technology, for the standard plant based on the improved technology of high-level decontamination cycle, and for the advanced plant based on the wet MOX cycle concept. It was concluded then that the construction costs in unit of the cost of the current plant were evaluated to be 0.60 for the standard plant (handling capacity 50 t/y) and 0.66 or 0.50 for the advanced plant (handling capacity 100 t/y or 50 t/y). (H. Baba)

  10. Florida's wet weather demonstration project : final report, January 2009.

    Science.gov (United States)

    2008-11-01

    The Florida Department of Transportation (FDOT) established a wet-weather pavement marking demonstration project with goals to gather performance data, evaluate various wet-weather marking systems, and develop a measurement protocol for measuring ret...

  11. Effect of a Brief Heat Exposure on Blood Pressure and Physical Performance of Older Women Living in the Community—A Pilot-Study

    Directory of Open Access Journals (Sweden)

    Anja Stotz

    2014-12-01

    Full Text Available Global climate change is affecting health and mortality, particularly in vulnerable populations. High ambient temperatures decrease blood pressure (BP in young and middle aged adults and may lead to orthostatic hypotension, increasing the risk of falls in older adults. The aim of this study was to evaluate the feasibility of a test protocol to investigate BP response and aerobic capacity of older adults in a hot indoor environment. BP response and aerobic capacity were assessed in 26 community-dwelling older women (median age 75.5 years at a room temperature of either 20 °C or 30 °C. The protocol was well tolerated by all participants. In the 30 °C condition systolic and diastolic BP (median difference 10 and 8 mmHg, respectively and distance walked in 6 min (median difference 29.3 m were lower than in the 20 °C condition (all p < 0.01. Systolic BP decreased after standing up from a lying position in the 30 °C (17.4 mmHg and 20 °C (14.2 mmHg condition (both p < 0.001. In conclusion, the protocol is feasible in this cohort and should be repeated in older adults with poor physical performance and impaired cardio-vascular response mechanisms. Furthermore, aerobic capacity was reduced after exposure to hot environmental temperatures, which should be considered when recommending exercise to older people during the summer months.

  12. Interplay of wetting and phase separation at surfaces

    Science.gov (United States)

    Puri, Sanjay

    2007-10-01

    We review our understanding of surface-directed spinodal decomposition (SDSD), i.e., the interplay of wetting and phase separation in an unstable AB mixture placed in contact with a wetting surface. In this context, we present results for two problems, viz., SDSD in a semi-infinite geometry with a completely wet surface; and SDSD in a thin-film geometry with partially wet surfaces.

  13. A new remote optical wetness sensor and its applications

    NARCIS (Netherlands)

    Heusinkveld, B.G.; Berkowicz, S.M.; Jacobs, A.F.G.; Hillen, W.C.A.M.; Holtslag, A.A.M.

    2008-01-01

    An optical wetness sensor (OWS) was developed for continuous surface wetness measurements. The sensor is an all-weather instrument that does not interfere with the surface wetting and drying process and is unaffected by solar radiation. It is equipped with its own light source with which it can scan

  14. Survival of Trichomonas vaginalis in wet preparation and on wet mount.

    Science.gov (United States)

    Stoner, Kevin A; Rabe, Lorna K; Meyn, Leslie A; Hillier, Sharon L

    2013-09-01

    Microscopy is an insensitive method for detection of Trichomonas vaginalis, but is widely used because it is both rapid and inexpensive. Diagnosis of trichomoniasis by microscopy requires that motile forms be identified in vaginal fluid samples. However, microscopy cannot always be performed immediately after sample collection. The objective of this study was to assess the impact of sample storage at room temperature on trichomonad motility. Vaginal swab samples from 77 women positive for T vaginalis infection were collected to determine the impact of storage on wet preparations (swabs in plastic tubes with saline) and wet mounts (samples placed onto a glass slide with a coverslip). Samples were read at 400× every 30 min for the first hour and then once per hour thereafter until there were no motile trichomonads observed. For wet preparations, motility was 100% at 30 min, 99% at 60 min and decreased by 3%-15% each subsequent hour, with samples having a lower density of trichomonads losing motility more quickly. Trichomonad motility diminished more rapidly in wet mounts compared with wet preparations, with a 20% decrement in motility in 60 min. These data suggest that vaginal fluid samples for diagnosis of trichomoniasis should be stored in saline rather than on microscope slides until they are examined under the microscope and samples should be evaluated by microscopy within an hour of collection. These findings also suggest that clinical sites which cannot perform microscopy within 1 h of sample collection should consider the use of other diagnostic tests.

  15. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

    2013-01-01

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

  16. Outcome of an artificial coccidial infection in poults under the influence of floor heating.

    Science.gov (United States)

    Abd El-Wahab, A; Visscher, C F; Wolken, S; Reperant, L-M; Beineke, A; Beyerbach, M; Kamphues, J

    2013-03-01

    Coccidiosis is one of the most prevalent diseases in poultry. The objective of the current study was to determine the effects of floor heating when poults were artificially infected with Eimeria regarding the outcome of the infection and secondary effects on litter quality and health of the foot pad. Two trials were performed. In each trial, 4 groups of 2-wk-old turkeys were reared for a 4-wk period. All birds were fed ad libitum identical pelleted diets without any anticoccidial additive. The first 2 groups were housed on dry wood shavings, with and without floor heating; the other 2 groups were housed on wet wood shavings (35% moisture, achieved by adding water as required), with and without floor heating. Two birds only (primary seeder birds; the other 18 birds were nominated as secondary infected birds) in each of the 4 groups were experimentally infected orally with Eimeria adenoeides (~50,000 oocysts/bird). The number of oocysts eliminated via excreta was determined repeatedly. On d 42, each bird not only was scored macroscopically for coccidial lesions in the cecum but also oocyst counts were determined in the cecal contents. Finally, the foot pads were assessed weekly for external scoring and on d 42 of life for histopathological scoring. Although the counts of oocysts in seeder birds were almost identical (d 6 postinoculation), oocyst counts in excreta of secondary birds were markedly reduced in both trials when the poults were not exposed to wet litter. Moreover, in both trials using floor heating with exposure to wet litter resulted in a higher oocyst count in the excreta of secondary infected birds (3.72/3.92 in trials 1 and 2) on d 24 postinoculation compared with the other groups. Using floor heating resulted in significantly decreased foot pad dermatitis scores compared with groups housed without floor heating. In conclusion, the differences in oocyst counts indicate that the process of sporulation is affected by both the moisture and the

  17. Interaction between a water drop and holey graphene: retarded imbibition and generation of novel water-graphene wetting states.

    Science.gov (United States)

    Wang, Yanbin; Sinha, Shayandev; Hu, Liangbing; Das, Siddhartha

    2017-10-18

    Transport of water through a holey or nanoporous graphene structure in presence of an external force (e.g., a pressure gradient) has paved the way for a myriad of applications ranging from water desalination to water-alcohol separation. In this study, on the other hand, we employ molecular dynamics (MD) simulations to probe no-external-force imbibition/permeation of a water nanodrop through a multilayer holey graphene structure. We carry out MD simulations in a two-dimensional set up; consequently, the holes in the graphene sheets appear as lateral separations between finite-length graphene layers, while the inter-layer distances appear as vertical separations. Interplay of lateral and vertical separations triggers combined spreading-imbibition dynamics, enforcing highly non-trivial water-graphene wetting states such as wetting-induced encapsulation of a complete graphene stack by the water drop, simultaneous wetting of multiple surfaces of multiple graphene stacks, and wetting with pinned and unpinned contact lines on vertically separated graphene layers. Finally, under certain combinations of lateral and vertical ISSs, there can be wetting of a much larger surface area of graphene, which is useful in applications (e.g., enhanced energy storage or heat transfer) favored by enhanced graphene-water contact area. Therefore, the present study has a twofold objective: first, it unravels, for the first time, water-holey graphene imbibition dynamics, and second, it identifies imbibition-triggered novel water-graphene wetting states for improving realistic applications involving graphene and water.

  18. Wet oxidation processes for water pollution remediation

    OpenAIRE

    García Molina, Verónica

    2006-01-01

    The main objective of this work was to test the efficiency of wet oxidation processes when treating several types of aqueous wastes. On one side its performance for the abatement of chloro-organic aromatic toxic pollutants, such as 4-chlorophenol and 2,4-dichlorophenol has been studied. On the other hand, wastewater from pulp and paper mills, which has been reported to be an indirect source of entry of chlorophenols in the aquatic environment, has been investigated. More in detail, it has bee...

  19. Collapse of granular media subjected to wetting

    Directory of Open Access Journals (Sweden)

    El Korchi Fatima Zahra

    2017-01-01

    Full Text Available This paper focuses on the collapse of granular materials subjected to wetting action. For soils, the collapse potential depends on several parameters such as liquid limit, matric suction, compactness, initial water content and the amount of fine particles. The effect of grain size, which plays a key role in the rearrangement of grains, remains little studied and poorly understood. To investigate the capillary origin of the collapse phenomenon, we present an experimental study on macroscopic and local scales. Our results show the effect of grain size and water content on collapse.

  20. Heat stress risk profiles for three non-woven coveralls.

    Science.gov (United States)

    Garzón-Villalba, Ximena P; Wu, Yougui; Ashley, Candi D; Bernard, Thomas E

    2018-01-01

    The ACGIH® Threshold Limit Value® (TLV®) is used to limit heat stress exposures so that most workers can maintain thermal equilibrium. That is, the TLV was set to an upper limit of Sustainable exposures for most people. This article addresses the ability of the TLV to differentiate between Sustainable and Unsustainable heat exposures for four clothing ensembles over a range of environmental factors and metabolic rates (M). The four clothing ensembles (woven clothing, and particle barrier, water barrier and vapor barrier coveralls) represented a wide range of evaporative resistances. Two progressive heat stress studies provided data on 480 trials with 1440 pairs of Sustainable and Unsustainable exposures for the clothing over three levels of relative humidity (rh) (20, 50 and 70%), three levels of metabolic rate (115, 180, and 254 Wm-2) using 29 participants. The exposure metric was the difference between the observed wet bulb globe temperature (WBGT) and the TLV. Risk was characterized by odds ratios (ORs), Receiver Operating Characteristic (ROC) curves, and dose-response curves for the four ensembles. Conditional logistic regression models provided information on ORs. Logistic regressions were used to determine ROC curves with area under the curve (AUC), model the dose-response curve, and estimate offsets from woven clothing. The ORs were about 2.5 per 1°C-WBGT for woven clothing, particle barrier, and water barrier and for vapor barrier at 50% rh. When using the published Clothing Adjustment Values (CAVs, also known as Clothing Adjustment Factors, CAFs) or the offsets that included different values for vapor barrier based on rh, the AUC for all clothing was 0.86. When the fixed CAVs of the TLV were used, the AUC was 0.81. In conclusion, (1) ORs and the shapes of the dose-response curves for the nonwoven coveralls were similar to woven clothing, and (2) CAVs provided a robust way to account for the risk of nonwoven clothing. The robust nature of CAV extended

  1. HEAT RECUPERATION

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2011-01-01

    Full Text Available Heat recovery is an effective method of shortening specific energy consumption. new constructions of recuperators for heating and cupola furnaces have been designed and successfully introduced. two-stage recuperator with computer control providing blast heating up to 600 °C and reducing fuel consumption by 30% is of special interest.

  2. Paludiculture on marginal lands - sustainable use of wet peatlands

    Science.gov (United States)

    Oehmke, Claudia; Dahms, Tobias; Wichmann, Sabine; Wichtmann, Wendelin

    2017-04-01

    Peatlands are marginal lands. If they are drained, they show a short initial productive period. Soil degradation due to peat oxidation leads to numerous problems which increasingly restrict agricultural use and cause significant environmental impacts such as greenhouse gas emissions and eutrophication and thereby produce high external costs. Worldwide greenhouse gas emissions from drained peatlands have a significant share ( 10%) in the emissions from agriculture, forestry and other land use (AFOLU) sectors (Smith et al. 2014). In Germany they contribute more than 35% to the total emissions from agriculture (agricultural sector and cropland and grassland management) (UBA 2016). Rewetting drained peatlands can significantly reduce environmental problems caused by peatland drainage. Continuation of agricultural use with adapted crops and machinery, so called paludiculture (Latin ‚palus' = swamp) stops further degradation, maintains the peat body, reduces climate change mitigation and produces renewable fuels and raw materials. Fen and bog soils are suitable for various different paludicultures. The biomass of Sphagnum (sphagnum farming) cultivated on cut-over bogs or degraded bog grasslands can be used as raw material for horticultural growing media. Flood-tolerant and productive plant species like Common Reed, Reed Canary Grass, Cattail, Black Alder and different Sedge species are suitable for paludiculture on fen soils. Biomass utilization ranges from traditional forms, like fodder production or the use of Common Reed as roof thatch, to new utilization options, that includes biomass use for heat generation, co-subtrates for biorefineries or construction and insulation products. The above-ground biomass of one hectare Common Reed (winter yield=8 t DM) equates to an energy content of 3,000 litre heating oil. A district heating plant (800 kW) in NE Germany demonstrates the feasibility of using biomass from wet fen meadows for local heat generation. Moreover, tests

  3. Prediction of thermal behavior of pyrolyzed wet biomass by means of model with inner wood structure

    Science.gov (United States)

    Polesek-Karczewska, Sylwia; Kardaś, Dariusz

    2015-02-01

    A simplified one-dimensional transient model for biomass pyrolysis in a fixed bed cylindrical reactor has been formulated and experiments have been carried out to verify the calculation results regarding temperature distribution. The mathematical model accounts for mass, momentum and heat transfer, including moisture evaporation and convection of pyrolysis gases. Numerical simulation has allowed to predict temperature and heat flux distribution, and the dynamics of feedstock devolatilization. Special attention has been devoted to the analysis of the effect of biomass moisture content on the pyrolysis process. The model of moisture vaporization in biomass bed was proposed, which included structure of surface of biomass particles. Assuming that vaporization occurs on the border of the dry and wet areas of the bed, the flux of water vaporization depends on the specific surface area of the particles and overall heat flux.

  4. A wetting and drying scheme for ROMS

    Science.gov (United States)

    Warner, John C.; Defne, Zafer; Haas, Kevin; Arango, Hernan G.

    2013-01-01

    The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud flats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always flow into any cell, but prevents outflow from a cell when the total depth in that cell is less than a user defined critical value. We describe the method, the implementation into the three-dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water flows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA.

  5. Wet paper codes with improved embedding efficiency

    Science.gov (United States)

    Fridrich, Jessica; Goljan, Miroslav; Soukal, David

    2006-02-01

    Construction of steganographic schemes in which the sender and the receiver do not share the knowledge about the location of embedding changes requires wet paper codes. Steganography with non-shared selection channels empowers the sender as now he is able to embed secret data by utilizing arbitrary side information, including a high-resolution version of the cover object (perturbed quantization steganography), local properties of the cover (adaptive steganography), and even pure randomness, e.g., coin flipping, for public key steganography. In this paper, we propose a new approach to wet paper codes using random linear codes of small codimension that at the same time improves the embedding efficiency-the number of message bits embedded per embedding change. We describe a practical algorithm, test its performance experimentally, and compare the results to theoretically achievable bounds. We point out an interesting ripple phenomenon that should be taken into account by practitioners. The proposed coding method can be modularly combined with most steganographic schemes to allow them to use non-shared selection channels and, at the same time, improve their security by decreasing the number of embedding changes.

  6. Further progress in watermark evaluation testbed (WET)

    Science.gov (United States)

    Kim, Hyung C.; Lin, Eugene T.; Guitart, Oriol; Delp, Edward J., III

    2005-03-01

    While Digital Watermarking has received much attention in recent years, it is still a relatively young technology. There are few accepted tools/metrics that can be used to evaluate the suitability of a watermarking technique for a specific application. This lack of a universally adopted set of metrics/methods has motivated us to develop a web-based digital watermark evaluation system called the Watermark Evaluation Testbed or WET. There have been more improvements over the first version of WET. We implemented batch mode with a queue that allows for user submitted jobs. In addition to StirMark 3.1 as an attack module, we added attack modules based on StirMark 4.0. For a new image fidelity measure, we evaluate conditional entropy as an image fidelity measure for different watermarking algorithms and different attacks. Also, we show the results of curve fitting the Receiver Operating Characteristic (ROC) analysis data using the Parzen window density estimation. The curve fits the data closely while having only two parameters to estimate.

  7. Temperature, hydric environment, and prior pathogen exposure alter the experimental severity of chytridiomycosis in boreal toads

    Science.gov (United States)

    Murphy, Peter J.; St-Hilaire, Sophie; Corn, Paul Stephen

    2011-01-01

    Prevalence of the pathogen Batrachochytrium dendrobatidis (Bd), implicated in amphibian population declines worldwide, is associated with habitat moisture and temperature, but few studies have varied these factors and measured the response to infection in amphibian hosts. We evaluated how varying humidity, contact with water, and temperature affected the manifestation of chytridiomycosis in boreal toads Anaxyrus (Bufo) boreas boreas and how prior exposure to Bd affects the likelihood of survival after re-exposure, such as may occur seasonally in long-lived species. Humidity did not affect survival or the degree of Bd infection, but a longer time in contact with water increased the likelihood of mortality. After exposure to ~106 Bd zoospores, all toads in continuous contact with water died within 30 d. Moreover, Bd-exposed toads that were disease-free after 64 d under dry conditions, developed lethal chytridiomycosis within 70 d of transfer to wet conditions. Toads in unheated aquaria (mean = 15°C) survived less than 48 d, while those in moderately heated aquaria (mean = 18°C) survived 115 d post-exposure and exhibited behavioral fever, selecting warmer sites across a temperature gradient. We also found benefits of prior Bd infection: previously exposed toads survived 3 times longer than Bd-naïve toads after re-exposure to 106 zoospores (89 vs. 30 d), but only when dry microenvironments were available. This study illustrates how the outcome of Bd infection in boreal toads is environmentally dependent: when continuously wet, high reinfection rates may overwhelm defenses, but periodic drying, moderate warming, and previous infection may allow infected toads to extend their survival.

  8. WetLab-2: Wet Lab RNA SmartCycler Providing PCR Capability on ISS

    Science.gov (United States)

    Parra, Macarena; Schonfeld, Julie

    2015-01-01

    The WetLab-2 system will provide sample preparation and qRT-PCR analysis on-board the ISS, a capability to enable using the ISS as a real laboratory. The system will be validated on SpX-7, and is planned for its first PI use on SpX-9.

  9. Doubly Reentrant Cavities Prevent Catastrophic Wetting Transitions on Intrinsically Wetting Surfaces

    KAUST Repository

    Domingues, Eddy

    2017-06-05

    Omniphobic surfaces, i.e. which repel all known liquids, have proven of value in applications ranging from membrane distillation to underwater drag reduction. A limitation of currently employed omniphobic surfaces is that they rely on perfluorinated coatings, increasing cost and environmental impact, and preventing applications in harsh environments. There is, thus, a keen interest in rendering conventional materials, such as plastics, omniphobic by micro/nano-texturing rather than via chemical make-up, with notable success having been achieved for silica surfaces with doubly reentrant micropillars. However, we found a critical limitation of microtextures comprising of pillars that they undergo catastrophic wetting transitions (apparent contact angles, θr → 0° from θr > 90°) in the presence of localized physical damages/defects or on immersion in wetting liquids. In response, a doubly reentrant cavity microtexture is introduced, which can prevent catastrophic wetting transitions in the presence of localized structural damage/defects or on immersion in wetting liquids. Remarkably, our silica surfaces with doubly reentrant cavities could exhibited apparent contact angles, θr ≈ 135° for mineral oil, where the intrinsic contact angle, θo ≈ 20°. Further, when immersed in mineral oil or water, doubly reentrant microtextures in silica (θo ≈ 40° for water) were not penetrated even after several days of investigation. Thus, microtextures comprising of doubly reentrant cavities might enable applications of conventional materials without chemical modifications, especially in scenarios that are prone to localized damages or immersion in wetting liquids, e.g. hydrodynamic drag reduction and membrane distillation.

  10. Proteomic effects of wet cupping (Al-hijamah).

    Science.gov (United States)

    Almaiman, Amer A

    2018-01-01

    Wet cupping (Al-hijamah) is a therapeutic technique practiced worldwide as a part of the Unani system of medicine. It involves bloodletting from acupoints on a patient's skin to produce a therapeutic outcome. A thorough review of research articles on wet cupping with relevance to proteomics field that are indexed by Google Scholar, PubMed, and/or Science Direct databases was performed. Eight original research articles were summarized in this paper. Overall, wet cupping did not have a significant effect on C-reactive protein, Hsp-27, sister chromatid exchanges, and cell replication index. In contrast, wet cupping was found to produce higher oxygen saturation, eliminate lactate from subcutaneous tissues, remove blood containing higher levels of malondialdehyde and nitric oxide, and produce higher activity of myeloperoxidase. The proteomic effects of wet cupping therapy have not been adequately investigated. Thus, future studies on wet cupping that use systemic and sound protocols to avoid bias should be conducted.

  11. Wet-cupping removes oxidants and decreases oxidative stress.

    Science.gov (United States)

    Tagil, Suleyman Murat; Celik, Huseyin Tugrul; Ciftci, Sefa; Kazanci, Fatmanur Hacievliyagil; Arslan, Muzeyyen; Erdamar, Nazan; Kesik, Yunus; Erdamar, Husamettin; Dane, Senol

    2014-12-01

    Wet-cupping therapy is one of the oldest known medical techniques. Although it is widely used in various conditions such as acute\\chronic inflammation, infectious diseases, and immune system disorders, its mechanism of action is not fully known. In this study, we investigated the oxidative status as the first step to elucidate possible mechanisms of action of wet cupping. Wet cupping therapy is implemented to 31 healthy volunteers. Venous blood samples and Wet cupping blood samples were taken concurrently. Serum nitricoxide, malondialdehyde levels and activity of superoxide dismutase and myeloperoxidase were measured spectrophotometrically. Wet cupping blood had higher activity of myeloperoxidase, lower activity of superoxide dismutase, higher levels of malondialdehyde and nitricoxide compared to the venous blood. Wet cupping removes oxidants and decreases oxidative stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Tympanoplasty: does dry or wet temporalis fascia graft matter?

    Science.gov (United States)

    Singh, G B; Kumar, D; Aggarwal, K; Garg, S; Arora, R; Kumar, S

    2016-08-01

    To evaluate the success rate of dry and wet temporalis fascia grafts in type I underlay tympanoplasty. A prospective, randomised study was conducted. One hundred adult patients (males and females) with chronic suppurative otitis media (mucosal type) were divided into 2 groups of 50 each: one group underwent dry graft tympanoplasty and the other underwent wet graft tympanoplasty. Fibroblast count was calculated in dry and wet grafts. The dry graft and wet graft groups had overall surgical success rates of 82 and 90 per cent, respectively; this finding was not statistically significant. A statistically significant high fibroblast count was observed in wet grafts, but it did not correlate with surgical success. A dry or wet temporalis fascia graft does not influence the outcome of tympanoplasty type I.

  13. Wick wetting for water condensation systems

    Science.gov (United States)

    Hering, Susanne Vera; Spielman, Steven Russel; Lewis, Gregory Stephen; Kreisberg, Nathan Michael

    2017-04-04

    A system and method for particle enlargement with continuously wetted wicks includes a container into which a flow of particle-laden air is introduced in a laminar manner through an inlet and to an outlet. The container has a first section, a second section and a third section though which the particle-laden air flows between the inlet and the outlet. The temperature of the second section is warmer than that of the first section at the inlet and the third section at the outlet. In one embodiment, a continuous wick spanning an interior wall of the first second, second section and third section, said wick being capable of internally transporting liquid water along its length is provided.

  14. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  15. Wet-Bulb-Globe Temperature Data Report

    Science.gov (United States)

    2015-03-01

    ARL‐SR‐0317 ● MAR 2015          US Army Research Laboratory      Wet‐ Bulb –Globe Temperature Data Report    by David P Sauter...originator.         ARL‐SR‐0317 ● MAR 2015      US Army Research Laboratory      Wet‐ Bulb –Globe Temperature Data Report    by David P Sauter...March 2015 2. REPORT TYPE  Special Report 3. DATES COVERED (From ‐ To)  11 Aug 2014–23 Aug 2014 4. TITLE AND SUBTITLE  Wet- Bulb –Globe Temperature

  16. Heated Goggles

    Science.gov (United States)

    1978-01-01

    The electrically heated ski goggles shown incorporate technology similar to that once used in Apollo astronauts' helmet visors, and for the same reason-providing fogfree sight in an activity that demands total vision. Defogging is accomplished by applying heat to prevent moisture condensation. Electric heat is supplied by a small battery built into the h goggles' headband. Heat is spread across the lenses by means of an invisible coating of electrically conductive metallic film. The goggles were introduced to the market last fall. They were designed by Sierracin Corporation, Sylmar, California, specialists in the field of heated transparent materials. The company produces heated windshields for military planes and for such civil aircraft as the Boeing 747, McDonnell Douglas DC-10 and Lockheed L-1011 TriStar.

  17. Modeling the early stages of reactive wetting.

    Science.gov (United States)

    Wheeler, Daniel; Warren, James A; Boettinger, William J

    2010-11-01

    Recent experimental studies of molten metal droplets wetting high-temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper investigates wetting and spreading on reactive substrates when inertial effects are dominant using a thermodynamically derived diffuse interface model of a binary three-phase material. The liquid-vapor transition is modeled using a van der Waals diffuse interface approach, while the solid-fluid transition is modeled using a phase field approach. The results from the simulations demonstrate an O(t(-1/2)) spreading rate during the inertial regime and oscillations in the triple-line position when the metal droplet transitions from inertial to diffusive spreading. It is found that the spreading extent is reduced by enhancing dissolution by manipulating the initial liquid composition. The results from the model exhibit good qualitative and quantitative agreement with a number of recent experimental studies of high-temperature droplet spreading, particularly experiments of copper droplets spreading on silicon substrates. Analysis of the numerical data from the model suggests that the extent and rate of spreading are regulated by the spreading coefficient calculated from a force balance based on a plausible definition of the instantaneous interface energies. A number of contemporary publications have discussed the likely dissipation mechanism in spreading droplets. Thus, we examine the dissipation mechanism using the entropy-production field and determine that dissipation primarily occurs in the locality of the triple-line region during the inertial stage but extends along the solid-liquid interface region during the diffusive stage.

  18. Bed wetting in school children of Karachi.

    Science.gov (United States)

    Mithani, Shoaib; Zaidi, Zafar

    2005-01-01

    To estimate the frequency of primary nocturnal enuresis (PNE) in Pakistani children and to examine the factors associated with it. A randomly selected cross-sectional study was conducted in five elementary schools, one in each of five districts of Karachi. The parents of 5000 children age between 3-13 years were asked to complete a questionnaire which included items about the frequency of daytime wetting and nocturnal enuresis, family history, urinary tract infection, parents and child's own concern about this problem and acquisition of treatments. Over all corrected response rate to the questionnaire was 69% (3395). Enuresis was present in 9.1% (308). There were 166 (53.9%) boys and 142 (46%) girls with a median age of 7 years. Only 54% (166) children sought help for their problem of which 26% consulted doctors, 16% visited homeopaths while 11% used hakeems and home remedies. Of the bed wetters, 30% were wet every night, 30% for more than three nights a week and 40% for less than three nights every week. Parents of 68.5% (211) children reported concern for the problem while 69.8% (215) children were also anxious about their enuresis. Among the concerned children group, 22% parents were not concerned about their child's problem. Family history of enuresis was present in 25.6% (79) children. The frequency of enuresis among the school going children in Karachi is 9.1% and is similar to that reported in European countries and other Asian countries including Korea and Taiwan. Enuresis causes concern to both parents and children, but only a small percentage of parents seek medical help for this problem.

  19. Improvement of the Rotary Dryers of Wet Pelletized Oil-Furnace Carbon Blacks

    Directory of Open Access Journals (Sweden)

    Zečević, M

    2010-05-01

    Full Text Available Due to the demand for higher production capacity and natural-gas energy savings, improvements were made to the rotary dryers in the drying process of wet pelletized oil-furnace carbon blacks. Since the rotary dryers were originally designed for drying semi-wet pelletized oil-furnace carbon blacks, they did not entirely satisfy optimal conditions for drying wet pelletized oil-furnace carbon blacks. Figure 1 shows the drying principle with key dimensions. The energy for drying the wet pelletized oil-furnace carbon blacks was provided by natural gas combustion in an open-furnace system with an uncontrolled feed of combustion air. Improvements on the rotary dryers were carried out by adjusting the excess oxygen in the gases passing through the butterfly valve on the dryer exhaust stack. By regulating the butterfly valve on the dryer exhaust stack, and applying the prescribed operations for drying wet pelletized oil furnace carbon blacks, the excess oxygen in the tail gases was adjusted in the range of φ = 3.0 % and 5.0 %, depending on the type of oil-furnace carbon blacks. Suggested also is installation of a direct-reverse automatic butterfly valve on the dryer exhaust stack to automatically determine the volume fraction of oxygen in the tail gas, and the volume flow rate of natural gas for combustion. The results the improvements carried out are shown in Tables 3 to 5. Table 2 shows the thermal calculations for the hood of the rotary dryer. Preheating of the process water in the temperature range of 70 °C and 80 °C is also recommended using the net heat from the oil-furnace process for wet pelletization. The results of preheating the process water are shown in Table 1. Depending on the type of oil-furnace carbon black, the aforementioned improvements resulted in natural gas energy savings ranging from 25 % to 35 % in relation to the average natural gas requirement in the drying process, and thus a reduction in carbon emissions of up to 40

  20. Pavement Marking Visibility Requirements During Wet Night Conditions

    OpenAIRE

    Gibbons, Ronald B. (Ronald Bruce)

    2006-01-01

    This study investigated the performance of pavement markings in wet night conditions. Typically, performance will decrease in wet conditions. The degradation is a result of flooding of the marking optics and a change in the optical media, thereby reducing retroreflectivity and the visibility distance. Several technologies are available to improve the visibility of markings under wet conditions. This study used four technologies and evaluated them in a dynamic situation. In the experiment, veh...

  1. Self-drying: a gecko's innate ability to remove water from wet toe pads.

    Directory of Open Access Journals (Sweden)

    Alyssa Y Stark

    Full Text Available When the adhesive toe pads of geckos become wet, they become ineffective in enabling geckos to stick to substrates. This result is puzzling given that many species of gecko are endemic to tropical environments where water covered surfaces are ubiquitous. We hypothesized that geckos can recover adhesive capabilities following exposure of their toe pads to water by walking on a dry surface, similar to the active self-cleaning of dirt particles. We measured the time it took to recover maximum shear adhesion after toe pads had become wet in two groups, those that were allowed to actively walk and those that were not. Keeping in mind the importance of substrate wettability to adhesion on wet surfaces, we also tested geckos on hydrophilic glass and an intermediately wetting substrate (polymethylmethacrylate; PMMA. We found that time to maximum shear adhesion recovery did not differ in the walking groups based on substrate wettability (22.7±5.1 min on glass and 15.4±0.3 min on PMMA but did have a significant effect in the non-walking groups (54.3±3.9 min on glass and 27.8±2.5 min on PMMA. Overall, we found that by actively walking, geckos were able to self-dry their wet toe pads and regain maximum shear adhesion significantly faster than those that did not walk. Our results highlight a unexpected property of the gecko adhesive system, the ability to actively self-dry and recover adhesive performance after being rendered dysfunctional by water.

  2. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability

    NARCIS (Netherlands)

    Bröde, P.; Kuklane, K.; Candas, V.; Hartog, E.A. den; Griefahn, B.; Holmér, I.; Meinander, H.; Nocker, W.; Richards, M.; Havenith, G.

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were

  3. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability.

    Science.gov (United States)

    Bröde, Peter; Kuklane, Kalev; Candas, Victor; Den Hartog, Emiel A; Griefahn, Barbara; Holmér, Ingvar; Meinander, Harriet; Nocker, Wolfgang; Richards, Mark; Havenith, George

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments' material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments.

  4. Exposure Forecaster

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Exposure Forecaster Database (ExpoCastDB) is EPA's database for aggregating chemical exposure information and can be used to help with chemical exposure...

  5. 49 CFR 173.159 - Batteries, wet.

    Science.gov (United States)

    2010-10-01

    ... impact resistant, the outer packaging must not be used as the sole means of protecting the battery... SHIPMENTS AND PACKAGINGS Non-bulk Packaging for Hazardous Materials Other Than Class 1 and Class 7 § 173.159... amount of heat sufficient to be dangerous to packaging or personal safety to include charring of...

  6. Letting Wet Spots be Wet: Restoring Natural Bioreactors in the Dissected Glacial Landscape

    Science.gov (United States)

    Schilling, Keith E.; McLellan, Eileen; Bettis, E. Arthur

    2013-12-01

    In this paper, we argue that there is tremendous potential for nitrate-N reductions to occur throughout the Corn Belt region of the USA if we simply let naturally occurring wet spots on the landscape be wet. Geologic and hydrologic data gathered in the Walnut Creek watershed located in south-central Iowa provides compelling evidence that substantial nutrient-processing capacity exists in this dissected glacial landscape. Self-similarity of stratigraphy, sedimentology and hydrology observed at all spatial scales in the watershed suggests that Holocene alluvial fill deposits provide a natural bioreactor for denitrification of upland groundwater nitrate-N; the occurrence of such deposits can be mapped to identify potential nitrogen sinks across the landscape. This approach to identifying potential nitrogen sinks is geology focused and extends potential locations for nutrient processing upstream into the headwater catchments of individual fields.

  7. Underwater Wet Repair Welding of API 5L X65M Pipeline Steel

    Directory of Open Access Journals (Sweden)

    Rogalski Grzegorz

    2017-04-01

    Full Text Available This paper presents results of the research of effect of polymer insulation of pipeline made of API 5L X65M steel as well as underwater wet welding parameters on properties of joints made by covered electrodes. Effect of heat input on structure and hardness of joints during repair of underwater pipeline was analyzed. Welding defects like microcracks, micro-lacks of fusion, slag inclusions, as well as HAZ hardness increase over an assumed acceptance criterion for welded joints in pipes without anticorrosion polymer insulation, were identified. A significant effect of polimer insulation on structure and properties of welded joints, was found.

  8. Update On Aquatic Toxicity/Whole Effluent Toxicity (WET) Issues, 2005

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Winona L

    2005-07-01

    This paper summarizes recent changes in the field of aquatic toxicity/Whole Effluent Toxicity (WET) testing. There are been numerous legal challenges to the validity of WET testing, both at the federal and state levels, but to date, the regulators have prevailed and WET testing is used as a regulatory tool to ensure that the biota of receiving streams are protected. The most recent ruling at the federal level was on December 10, 2004, when a federal appeals court in the District of Columbia upheld the validity of WET testing. At the state level, at the urging of the South Carolina Manufacturers Alliance, the state legislature passed a law (the South Carolina Aquatic Life Protection Act) in 2004 that requires the South Carolina Department of Health and Environmental Control (DHEC) to evaluate the accuracy and precision of the WET test. As a result, SCDHEC removed WET test limits from several NPDES permits. EPA took issue with the impact of the legislation and SCDHEC's actions, and as a result, EPA has taken over several NPDES permits from SCDHEC and threatened to revoke the state's delegated NPDES permit program. A new Act was signed into law in March 2005, which does not exclude the use of chronic toxicity testing for regulatory compliance. As a result, EPA has turned over the issuance of NPDES permits back to SCDHEC. In December 2004, the U.S. EPA issued the Draft National WET Implementation Guidance document for review and comment. The guidance contains recommendations on the determination of ''reasonable potential'' for toxicity. The EPA's ECOTOX database is a valuable resource of toxicity data for many chemicals. For those cases in which there are no toxicity data or very limited data available, the EPA has developed two models, the Interspecies Correlation Estimation (ICE) and the Acute to Chronic Estimation (ACE), for predicting toxicity. Active areas of research include assessing the uptake of heavy metals via multiple

  9. Process for producing an activated carbon adsorbent with integral heat transfer apparatus

    Science.gov (United States)

    Jones, Jack A. (Inventor); Yavrouian, Andre H. (Inventor)

    1996-01-01

    A process for producing an integral adsorbent-heat exchanger apparatus useful in ammonia refrigerant heat pump systems. In one embodiment, the process wets an activated carbon particles-solvent mixture with a binder-solvent mixture, presses the binder wetted activated carbon mixture on a metal tube surface and thereafter pyrolyzes the mixture to form a bonded activated carbon matrix adjoined to the tube surface. The integral apparatus can be easily and inexpensively produced by the process in large quantities.

  10. Hydraulic Validation of the LHC Cold Mass Heat Exchanger Tube

    CERN Document Server

    Provenaz, P

    1998-01-01

    The knowledge of the helium mass flow vs. the fraction of the tube wetted by the liquid helium II in the heat exchanger is a crucial input parameter for the heat exchange since the heat flux is direct ly proportional to the wetted surface. In the range of liquid and gas velocities inside the heat exchanger, the liquid flow behaves like in an open channel. Looking at the flow equations for such a s ituation, the velocity depends on the fluid properties only by the friction factor which is a function of the Reynolds number. Thus it was decided to build an experiment with water in order to check t he open channel equations in the heat exchanger geometry. This paper shows the results for water and gives the extrapolation for helium.

  11. Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

    Science.gov (United States)

    Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

    2015-10-01

    Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Heat Stroke

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  13. Semen quality in welders exposed to radiant heat.

    OpenAIRE

    Bonde, J P

    1992-01-01

    Several studies suggest that welding is detrimental to the male reproductive system. Welding fume and radiant heat are of interest as possible causal factors. This study investigates semen quality and sex hormone concentrations among 17 manual metal arc alloyed steel welders with a moderate exposure to radiant heat (globe temperature ranging from 31.1 degrees to 44.8 degrees C), but without substantial exposure to welding fume toxicants. During exposure to heat the skin temperature in the gro...

  14. Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction

    Directory of Open Access Journals (Sweden)

    C. C. Niva

    Full Text Available Abstract Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region. The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold and 5.000-12.000 ind./ m2 (hot, respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

  15. Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction.

    Science.gov (United States)

    Niva, C C; Cezar, R M; Fonseca, P M; Zagatto, M R G; Oliveira, E M; Bush, E F; Clasen, L A; Brown, G G

    2015-11-01

    Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region). The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold) and 5.000-12.000 ind./ m2 (hot), respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

  16. In-situ transesterification of wet spent coffee grounds for sustainable biodiesel production.

    Science.gov (United States)

    Park, Jeongseok; Kim, Bora; Lee, Jae W

    2016-12-01

    This work addresses in-situ transesterification of wet spent coffee grounds (SCGs) for the production of biodiesel. For in-situ transesterification process, the methanol, organic solvent and acid catalyst were mixed with wet SCG in one pot and the mixture was heated for simultaneous lipid extraction and transesterification. Maximum yield of fatty acid methyl esters (FAME) was 16.75wt.% based on the weight of dry SCG at 95°C. Comprehensive experiments were conducted with varying temperatures and various amounts of moisture, methanol, co-solvent and acid catalyst. Moderate polar and alcohol-miscible organic solvent is suitable for the high FAME yield. Unsaturated FAMEs are subject to oxidative cleavage by nitric acid and shorter chain (C6 and C10) FAMEs were mainly produced while sulfuric acid yielded long chain unsaturated FAMEs (C16 and C18). Utilization of wet SCGs as a biodiesel feedstock gives economic and environmental benefits by recycling the municipal waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Wet in situ transesterification of microalgae using ethyl acetate as a co-solvent and reactant.

    Science.gov (United States)

    Park, Jeongseok; Kim, Bora; Chang, Yong Keun; Lee, Jae W

    2017-04-01

    This study addresses wet in situ transesterification of microalgae for the production of biodiesel by introducing ethyl acetate as both reactant and co-solvent. Ethyl acetate and acid catalyst are mixed with wet microalgae in one pot and the mixture is heated for simultaneous lipid extraction and transesterification. As a single reactant and co-solvent, ethyl acetate can provide higher FAEE yield and more saccharification of carbohydrates than the case of binary ethanol and chloroform as a reactant and a co-solvent. The optimal yield was 97.8wt% at 114°C and 4.06M catalyst with 6.67mlEtOAC/g dried algae based on experimental results and response surface methodology (RSM). This wet in situ transesterification of microalgae using ethyl acetate doesn't require an additional co-solvent and it also promises more economic benefit as combining extraction and transesterification in a single process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Spatial and temporal variations in the occurrences of wet periods ...

    Indian Academy of Sciences (India)

    This study highlights the hydro-climatic features of the five wet periods contributing in different percentages to the annual rainfall total over major river basins in India. Spatial and temporal variations in the parameters such as starting date, duration and rainfall intensity of these wet periods throughout India have been ...

  19. Spatial and temporal variations in the occurrences of wet periods ...

    Indian Academy of Sciences (India)

    This study highlights the hydro-climatic features of the five wet periods contributing in different percentages to the annual rainfall total over major river basins in India.Spatial and temporal variations in the parameters such as starting date,duration and rainfall intensity of these wet periods throughout India have been ...

  20. Electrophoretic deposition of titania nanoparticles: Wet density of ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Electrophoretic deposition (EPD) of titania nanoparticles was performed at different voltages and times. The wet density of deposits was calculated according to the Archimedes' principle. The wet density as well as the electric field over the deposits increased with time and attained the plateau at longer times. The.

  1. Hydrodynamics of a Multistage Wet Scrubber Incineration Conditions

    Science.gov (United States)

    Said, M. M.; Manyele, S. V.; Raphael, M. L.

    2012-01-01

    The objective of the study was to determine the hydrodynamics of the two stage counter-current cascade wet scrubbers used during incineration of medical waste. The dependence of the hydrodynamics on two main variables was studied: Inlet air flow rate and inlet liquid flow rate. This study introduces a new wet scrubber operating features, which are…

  2. The Influence of Wetting Rate and Electrolyte Concentration on the ...

    African Journals Online (AJOL)

    Substantial macroscopic swelling of rapidly wetted soil was attributed to air compressed into the largest available voids. Consequent soil matrix failure resulted in macroscopic swelling and increased sorption of water. Hydraulic conductivity appeared to be a non-linear function of wetting rate over the range w = 0-30 mm ...

  3. Phase change materials and the perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, A.M.L.; Daanen, H.A.M.

    2012-01-01

    Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

  4. Phase Change Materials and the perception of wetness.

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.; Daanen, H.A.M.

    2012-01-01

    Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

  5. Comparative Batch and Column Evaluation of Thermal and Wet ...

    African Journals Online (AJOL)

    ABSTRACT: The efficiency of regenerated spent commercial activated carbon for synthetic dye removal was studied using thermal and wet ... Keywords: Activated Carbon, Methyl Red, Chromatography Capacity, Wet and Thermal Regeneration. INTRODUCTION ... processes in wastewater treatment. A number of techniques ...

  6. Southern African Regional Science Initiative (SAFARI 2000): wet season campaigns

    CSIR Research Space (South Africa)

    Otter, LB

    2002-03-01

    Full Text Available The Southern African Regional Science Initiative (SAFARI 2000) involved two wet season and one dry season field campaigns. This paper reports on the wet season campaigns. The first was conducted at five sites along the Kalahari Transect in Zambia...

  7. Fluorinated Silsesquioxanes: Structure, Solubility, and Wetting (Briefing charts)

    Science.gov (United States)

    2015-08-01

    Charts 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE FLUORINATED SILSESQUIOXANES: STRUCTURE, SOLUBILITY , AND WETTING...FLUORINATED SILSESQUIOXANES: STRUCTURE, SOLUBILITY , AND WETTING Joseph Mabry, Andrew Guenthner, Scott Iacono, Raymond Campos, Sean Ramirez, Brian Moore...Crystalline solids • Soluble in fluorinated solvents 5DISTRIBUTION A. Approved for public release; distribution unlimited. • Spin-cast surface of FD

  8. Electrophoretic deposition of titania nanoparticles: Wet density of ...

    Indian Academy of Sciences (India)

    Electrophoretic deposition (EPD) of titania nanoparticles was performed at different voltages and times. The wet density of deposits was calculated according to the Archimedes' principle. The wet density as well as the electric field over the deposits increased with time and attained the plateau at longer times. The velocity at ...

  9. Thermal denaturation behavior of collagen fibrils in wet and dry environment.

    Science.gov (United States)

    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. © 2015 Wiley Periodicals, Inc.

  10. Tactile cues significantly modulate the perception of sweat-induced skin wetness independently of the level of physical skin wetness.

    Science.gov (United States)

    Filingeri, Davide; Fournet, Damien; Hodder, Simon; Havenith, George

    2015-06-01

    Humans sense the wetness of a wet surface through the somatosensory integration of thermal and tactile inputs generated by the interaction between skin and moisture. However, little is known on how wetness is sensed when moisture is produced via sweating. We tested the hypothesis that, in the absence of skin cooling, intermittent tactile cues, as coded by low-threshold skin mechanoreceptors, modulate the perception of sweat-induced skin wetness, independently of the level of physical wetness. Ten males (22 yr old) performed an incremental exercise protocol during two trials designed to induce the same physical skin wetness but to induce lower (TIGHT-FIT) and higher (LOOSE-FIT) wetness perception. In the TIGHT-FIT, a tight-fitting clothing ensemble limited intermittent skin-sweat-clothing tactile interactions. In the LOOSE-FIT, a loose-fitting ensemble allowed free skin-sweat-clothing interactions. Heart rate, core and skin temperature, galvanic skin conductance (GSC), and physical (w(body)) and perceived skin wetness were recorded. Exercise-induced sweat production and physical wetness increased significantly [GSC: 3.1 μS, SD 0.3 to 18.8 μS, SD 1.3, P FIT and LOOSE-FIT (P > 0.05). However, the limited intermittent tactile inputs generated by the TIGHT-FIT ensemble reduced significantly whole-body and regional wetness perception (P < 0.01). This reduction was more pronounced when between 40 and 80% of the body was covered in sweat. We conclude that the central integration of intermittent mechanical interactions between skin, sweat, and clothing, as coded by low-threshold skin mechanoreceptors, significantly contributes to the ability to sense sweat-induced skin wetness. Copyright © 2015 the American Physiological Society.

  11. Reversible wetting of titanium dioxide films

    Science.gov (United States)

    Toh, A. G. G.; Nolan, M. G.; Cai, R.; Butler, D. L.

    2007-12-01

    Titanium dioxide (TiO II) films were rendered hydrophilic through ultraviolet (UV) light irradiation (254nm) and returned to their previous hydrophobic condition when exposed to a sealed pressurized nitrogen atmosphere. UV light irradiation on TiO II films resulted in super-hydrophilic surfaces with water contact angles of 40°. The switching of TiO II surface wettability could be repeated on the same surface with little hysteresis in water contact angle values. The mechanism behind the hydrophilic and hydrophobic reversal in TiO II surfaces is proposed to be due to UV light mediated photocatalysis and physio- adsorption of N II molecules respectively. The non-intrusive control of TiO II surface wettability could be an attractive alternative to other wettability-based microfluidic valving strategies like electrowetting and photochromic wetting variation. The above results are discussed in terms of the potential use of the films in wettability based valving and repeated wettability patterning of TiO II surfaces for open and sealed microfluidic systems.

  12. Wet process technology in the semiconductor manufacturing process. 1. Physics and chemistry of wet cleaning process; Handotai process ni okeru wet process. Wet senjo no butsuri kagaku

    Energy Technology Data Exchange (ETDEWEB)

    Ryuta, J. [Mitsubishi Materials Corp., Tokyo (Japan)

    1995-03-05

    The wet cleaning consists of a cleaning process in chemicals and a rinse process using ultra-pure water. Among a series of cleaning process, this paper focuses on the SC1 (standard cleaning 1) process using NH4OH, H2O2, and H2O. During the SC1 process, two reactions progress simultaneously, i.e., natural oxidation and etching reactions on the wafer surface. As a consequence of measurement of the oxide film thickness, it was found that the reaction rate during the initial oxidation is extremely high. As a result of measurement of the etching rate, it was also found that the etching reaction is affected by the oxidation reaction. It is illustrated that pits, which are caused by defects in the crystal, are formed during the repeated SC1 process. It is also illustrated that the adsorption and desorption of Fe occur simultaneously on the wafer surface during the SC1 process. It was found that a clean wafer surface can be obtained by removing the particles and metal impurities in the cleaning liquid. 10 refs., 12 figs., 1 tab.

  13. Photochemical organonitrate formation in wet aerosols

    Directory of Open Access Journals (Sweden)

    Y. B. Lim

    2016-10-01

    Full Text Available Water is the most abundant component of atmospheric fine aerosol. However, despite rapid progress, multiphase chemistry involving wet aerosols is still poorly understood. In this work, we report results from smog chamber photooxidation of glyoxal- and OH-containing ammonium sulfate or sulfuric acid particles in the presence of NOx and O3 at high and low relative humidity. Particles were analyzed using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS. During the 3 h irradiation, OH oxidation products of glyoxal that are also produced in dilute aqueous solutions (e.g., oxalic acids and tartaric acids were formed in both ammonium sulfate (AS aerosols and sulfuric acid (SA aerosols. However, the major products were organonitrogens (CHNO, organosulfates (CHOS, and organonitrogen sulfates (CHNOS. These were also the dominant products formed in the dark chamber, indicating non-radical formation. In the humid chamber (> 70 % relative humidity, RH, two main products for both AS and SA aerosols were organonitrates, which appeared at m ∕ z− 147 and 226. They were formed in the aqueous phase via non-radical reactions of glyoxal and nitric acid, and their formation was enhanced by photochemistry because of the photochemical formation of nitric acid via reactions of peroxy radicals, NOx and OH during the irradiation.

  14. Cardiovascular magnetic resonance in wet beriberi

    Directory of Open Access Journals (Sweden)

    Giri Shivraman

    2011-08-01

    Full Text Available Abstract The clinical presentation of beriberi can be quite varied. In the extreme form, profound cardiovascular involvement leads to circulatory collapse and death. This case report is of a 72 year-old male who was admitted to the Neurology inpatient ward with progressive bilateral lower extremity weakness and parasthesia. He subsequently developed pulmonary edema and high output cardiac failure requiring intubation and blood pressure support. With the constellation of peripheral neuropathy, encephalopathy, ophthalmoplegia, unexplained heart failure, and lactic acidosis, thiamine deficiency was suspected. He was empirically initiated on thiamine replacement therapy and his thiamine level pre-therapy was found to be 23 nmol/L (Normal: 80-150 nmol/L, consistent with the diagnosis of beriberi. Cardiovascular magnetic resonance (CMR showed severe left ventricular systolic dysfunction, markedly increased myocardial T2, and minimal late gadolinium enhancement (LGE. After 5 days of daily 100 mg IV thiamine and supportive care, the hypotension resolved and the patient was extubated and was released from the hospital 3 weeks later. Our case shows via CMR profound myocardial edema associated with wet beriberi.

  15. Metal--nanotube interactions -- wetting properties

    Science.gov (United States)

    Zhu, Ruzeng; Cui, Shuwen

    2011-03-01

    The wetting properties of metal nanoparticles in large-diameter single Carbon nanotubes (LDSWNT) is studied by considering the size effect on surface tension of the metal cluster. For the case of macro-nonwetting, we get finite critical atom number N such that the metal cluster with any atom number smaller than it has contact angle π , and so it shrinks into a ball. For an experiential formula of the surface tension of cluster expressed by the number of atoms, we determine the parameters in it for Pd and Pt respectively by density functional theory (DFT). Taking a graphene sheet as a representative of LDSWNT and using the known data of the surface tensions of solid and liquid, we obtain solid-liquid interface tension through Berthelot rule. Based on these results, we obtain N=5 for Pd and N=6 for Pt. For cluster containing 13 Pd atoms and that containing 13 Pt atoms, we use the above mentioned experiential formula to obtain their contact angles in LDSWNT consistent with those shown by the pictures given by DFT (A Maiti and A Ricca, Chem Phys Letters 395 (2004) 7--11), and thus the validity of our method is proved. Project supported by the National Natural Science Foundation of China (Grant No.11072242).

  16. Wetting of silicone oil onto a cell-seeded substrate

    Science.gov (United States)

    Lu, Yongjie; Chan, Yau Kei; Chao, Youchuang; Shum, Ho Cheung

    2017-11-01

    Wetting behavior of solid substrates in three-phase systems containing two immiscible liquids are widely studied. There exist many three-phase systems in biological environments, such as droplet-based microfluidics or tamponade of silicone oil for eye surgery. However, few studies focus on wetting behavior of biological surfaces with cells. Here we investigate wetting of silicone oil onto cell-seeded PMMA sheet immersed in water. Using a simple parallel-plate cell, we show the effect of cell density, viscosity of silicone oil, morphology of silicone oil drops and interfacial tension on the wetting phenomenon. The dynamics of wetting is also observed by squeezing silicone oil drop using two parallel plates. Experimental results are explained based on disjoining pressure which is dependent on the interaction of biological surfaces and liquid used. These findings are useful for explaining emulsification of silicone oil in ophthalmological applications.

  17. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, Søren

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full-scale...... was found to decrease the rate of gas phase mass transport with up to 15 %, though the effect could not be correlated.A detailed model for a wet FGD pilot plant, based on the falling film principle, was devel-oped. All important rate determining steps, absorption of SO2, oxidation of HSO3-, dissolution...... - 333 K, pertinent for full-scale wet FGD packed towers. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No ef-fects on the overall performance of the wet FGD plant were observed, though laboratory ex-periments with fine dust and fly ash from the full-scale...

  18. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1994-01-01

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

  19. Water-induced finger wrinkles do not affect touch acuity or dexterity in handling wet objects

    OpenAIRE

    Haseleu, J.; Omerbasic, D.; Frenzel, H.; Gross, M.; Lewin, G.R.

    2014-01-01

    Human non-hairy (glabrous) skin of the fingers, palms and soles wrinkles after prolonged exposure to water. Wrinkling is a sympathetic nervous system-dependent process but little is known about the physiology and potential functions of water-induced skin wrinkling. Here we investigated the idea that wrinkling might improve handling of wet objects by measuring the performance of a large cohort of human subjects (n = 40) in a manual dexterity task. We also tested the idea that skin wrinkling ha...

  20. Fabricating continuous electroconductive polyacrylonitrile fibers with thermosensitive property via wet-spinning

    Science.gov (United States)

    Liu, Wanwan; Jin, Yang; Wang, Yangyi; Ge, Mingqiao; Gao, Qiang

    2017-12-01

    In this work, conductive polyacrylonitrile (PAN) composite fiber with thermosensitive property was successfully prepared via wet-spinning. Thermochromic pigment (TCP) microsphere capsules were applied to manufacture color-changing fibers. Meanwhile, light-colored conductive whiskers (ATO@TiO2) were employed to endow polyacrylonitrile fibers with conductivity without prejudicing their thermosensitive property. Interestingly, unlike other conductive fibers in dark color, this kind of conductive composite fiber can be dyed by thermosensitive pigment. The obtained composite fiber containing 20 vol% ATO@TiO2 whiskers shows a resistivity of 105 Ω · cm and could generate heat by Joule heating when being applied under a certain voltage. The composite fiber shows a red color at room temperature, while the color of the composite fiber fades gradually and finally becomes white as temperature rise. This simple and cost-effective approach is expected to inspire more research into the applications of multifunctional conductive fibers.

  1. Repeated bouncing of drops on wetting and non-wetting surfaces mediated by a persisting thin air film

    NARCIS (Netherlands)

    de Ruiter, J.; Lagraauw, R.; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther

    2014-01-01

    Abstract Submitted for the DFD14 Meeting of The American Physical Society Repeated bouncing of drops on wetting and non-wetting sur- faces mediated by a persisting thin air lm JOLET DE RUITER, RUDY LAGRAAUW, DIRK VAN DEN ENDE, FRIEDER MUGELE, MESA+ Institute for Nanotechnology, University of Twente

  2. Imaging of oil layers, curvature and contact angle in a mixed‐wet and a water‐wet carbonate rock

    National Research Council Canada - National Science Library

    Singh, Kamaljit; Bijeljic, Branko; Blunt, Martin J

    2016-01-01

    ...‐wet), whereas the untreated rock (without doped oil) was weakly water‐wet (θ=47 ± 9°). Using X‐ray micro‐tomography, we show that the brine displaces oil in larger pores during brine injection in the mixed...

  3. Calibration of Heat Stress Monitor and its Measurement Uncertainty

    Science.gov (United States)

    Ekici, Can

    2017-07-01

    Wet-bulb globe temperature (WBGT) equation is a heat stress index that gives information for the workers in the industrial areas. WBGT equation is described in ISO Standard 7243 (ISO 7243 in Hot environments—estimation of the heat stress on working man, based on the WBGT index, ISO, Geneva, 1982). WBGT is the result of the combined quantitative effects of the natural wet-bulb temperature, dry-bulb temperature, and air temperature. WBGT is a calculated parameter. WBGT uses input estimates, and heat stress monitor measures these quantities. In this study, the calibration method of a heat stress monitor is described, and the model function for measurement uncertainty is given. Sensitivity coefficients were derived according to GUM. Two-pressure humidity generators were used to generate a controlled environment. Heat stress monitor was calibrated inside of the generator. Two-pressure humidity generator, which is located in Turkish Standard Institution, was used as the reference device. This device is traceable to national standards. Two-pressure humidity generator includes reference temperature Pt-100 sensors. The reference sensor was sheltered with a wet wick for the calibration of natural wet-bulb thermometer. The reference sensor was centred into a black globe that has got 150 mm diameter for the calibration of the black globe thermometer.

  4. Effect of Copper-based Fillers Composition On Spreading and Wetting Behaviour

    Science.gov (United States)

    Hissyam, W. N. W. M. N.; Halil, A. M.; Kurniawan, T.; Ishak, M.; Ariga, T.

    2017-09-01

    Wetting and spreading of molten brazing filler material are important factors that influence the brazing ability of a joint to be brazed. Several investigations into the wetting ability of a brazing filler alloy and its spreading area in the molten state, in addition to effects of brazing temperature on the contact angle, have been carried out. Generally, the composition of copper-based filler and temperature affect spreading of molten brazing filler material during brazing. Wetting by and interfacial reactions of the molten brazing filler material with the metallic substrate, especially, affect strongly the spreading of the filler material. In this study, the effects of filler composition and brazing temperature on the spreading of molten brazing filler metallic alloys were investigated. MBF 2005 (Cu, 5.7wt.%Ni, 9.7wt.%Sn, 7.0wt.%P), MBF 2002 (Cu, 9.9wt.%Ni, 4.0wt.%Sn, 7.8wt.%P) and VZ 2250 (Cu, 7.0wt.%Ni, 9.3wt.%Sn, 6.3wt.%P) alloys were used as brazing filler materials. Pure copper block and a rectangular plate were employed as the base metal. Brazing filler material and metallic base plate were first washed with acetone. Brazing was performed at 750°C and 800°C under Ar gas for 30 minutes using an electrically heated furnace, after which, the original spreading area, defined as the sessile drop area, and the apparent spreading area were both evaluated. It was observed that the spreading area and wetting angle influenced by the composition of copper-based filler.

  5. Quadrilateral Micro-Hole Array Machining on Invar Thin Film: Wet Etching and Electrochemical Fusion Machining.

    Science.gov (United States)

    Choi, Woong-Kirl; Kim, Seong-Hyun; Choi, Seung-Geon; Lee, Eun-Sang

    2018-01-19

    Ultra-precision products which contain a micro-hole array have recently shown remarkable demand growth in many fields, especially in the semiconductor and display industries. Photoresist etching and electrochemical machining are widely known as precision methods for machining micro-holes with no residual stress and lower surface roughness on the fabricated products. The Invar shadow masks used for organic light-emitting diodes (OLEDs) contain numerous micro-holes and are currently machined by a photoresist etching method. However, this method has several problems, such as uncontrollable hole machining accuracy, non-etched areas, and overcutting. To solve these problems, a machining method that combines photoresist etching and electrochemical machining can be applied. In this study, negative photoresist with a quadrilateral hole array pattern was dry coated onto 30-µm-thick Invar thin film, and then exposure and development were carried out. After that, photoresist single-side wet etching and a fusion method of wet etching-electrochemical machining were used to machine micro-holes on the Invar. The hole machining geometry, surface quality, and overcutting characteristics of the methods were studied. Wet etching and electrochemical fusion machining can improve the accuracy and surface quality. The overcutting phenomenon can also be controlled by the fusion machining. Experimental results show that the proposed method is promising for the fabrication of Invar film shadow masks.

  6. OF PHYSIOLOGICAL REACTIONS AND PHYSIOLOGICAL STRAIN IN HEALTHY MEN UNDER HEAT STRESS IN DRY AND STEAM HEAT SAUNAS

    Directory of Open Access Journals (Sweden)

    W. Pilch

    2014-07-01

    Full Text Available The aim of the paper was to follow up major physiological reactions, provoked by heat stress during dry and wet sauna baths. A physical strain index and subjective estimation of heat comfort of subjects who had not taken sauna baths before was also evaluated. Ten healthy males aged 25-28 underwent a dry sauna bath and then after a one-month break they underwent a steam sauna bath. Each time, they entered the sauna chamber 3 times for 15 minutes with five-minute breaks. During breaks they cooled their bodies with a cold shower and then rested in a sitting position. Before and after the baths, body mass and blood pressure were measured. Rectal temperature and heart rate were monitored during the baths. The physiological strain index (PSI and cumulative heat strain index (CHSI were calculated. Subjects assessed heat comfort by Bedford’s scale. Greater body mass losses were observed after the dry sauna bath compared to the wet sauna (-0.72 vs. -0.36 kg respectively. However, larger increases in rectal temperature and heart rate were observed during the wet sauna bath (38.8% and 21.2% respectively. Both types of sauna baths caused elevation of systolic blood pressure, but changes were greater after the dry one. Diastolic pressure was reduced similarly. Subjective feelings of heat comfort as well as PSI (4.83 ± 0.29 vs. 5.7 ± 0.28 and CHSI (76.3 ± 18.4 vs. 144.6 ± 21.7 were greater during the wet sauna bath. It can be concluded that due to high humidity and reduction of thermoregulation mechanisms, the wet sauna is more stressful for the organism than the dry sauna, where the temperature is higher with low humidity. Both observed indexes (PSI and CHSI could be appropriate for objective assessment of heat strain during passive heating of the organism.

  7. The effects of heat stress on a number of hematological parameters and levels of thyroid hormones in foundry workers.

    Science.gov (United States)

    Norloei, Sahar; Jafari, Mohammad Javad; Omidi, Leila; Khodakarim, Soheila; Bashash, Davood; Abdollahi, Mohammad Bagher; Jafari, Mina

    2017-12-01

    The objective of this research was to determine the effects of heat stress on some hematological parameters and thyroid hormones among foundry workers. This study was performed on 25 heat-acclimated subjects while 10 office workers were selected as the control group. Wet bulb globe temperature (WBGT) was determined to estimate the heat stress. Blood sampling was conducted before and after the daily work shift. The mean value of the WBGT index was 35 °C. The levels of plasma osmolality (p = 0.04) and white blood cells (p = 0.03) in the case group (before exposure to heat) were significantly higher than those in control group. No significant differences were observed between the average levels of T3 (p = 0.79) and T4 (p = 0.17) hormones between two groups. A positive relationship was found between the variation of some hematological parameters and thyroid hormones with WBGT index and air temperature.

  8. Waste heat rejection from geothermal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, R.C.

    1978-12-01

    This study of waste heat rejection from geothermal power stations is concerned only with the heat rejected from the power cycle. The heat contained in reinjected or otherwise discharged geothermal fluids is not included with the waste heat considered here. The heat contained in the underflow from the flashtanks in such systems is not considered as part of the heat rejected from the power cycle. By following this definition of the waste heat to be rejected, various methods of waste heat dissipation are discussed without regard for the particular arrangement to obtain heat from the geothermal source. Recent conceptual design studies made for 50-MW(e) geothermal power stations at Heber and Niland, California, are of particular interst. The former uses a flashed-steam system and the latter a binary cycle that uses isopentane. In last-quarter 1976 dollars, the total estimated capital costs were about $750/kW and production costs about 50 mills/kWhr. If wet/dry towers were used to conserve 50% of the water evaporation at Heber, production costs would be about 65 mills/kWhr.

  9. Conjugate heat transfer characterization in cooling channels

    Science.gov (United States)

    Cukurel, Beni; Arts, Tony; Selcan, Claudio

    2012-06-01

    Cooling technology of gas turbine blades, primarily ensured via internal forced convection, is aimed towards withdrawing thermal energy from the airfoil. To promote heat exchange, the walls of internal cooling passages are lined with repeated geometrical flow disturbance elements and surface non-uniformities. Raising the heat transfer at the expense of increased pressure loss; the goal is to obtain the highest possible cooling effectiveness at the lowest possible pressure drop penalty. The cooling channel heat transfer problem involves convection in the fluid domain and conduction in the solid. This coupled behavior is known as conjugate heat transfer. This experimental study models the effects of conduction coupling on convective heat transfer by applying iso-heat-flux boundary condition at the external side of a scaled serpentine passage. Investigations involve local temperature measurements performed by Infrared Thermography over flat and ribbed slab configurations. Nusselt number distributions along the wetted surface are obtained by means of heat flux distributions, computed from an energy balance within the metal domain. For the flat plate experiments, the effect of conjugate boundary condition on heat transfer is estimated to be in the order of 3%. In the ribbed channel case, the normalized Nusselt number distributions are compared with the basic flow features. Contrasting the findings with other conjugate and convective iso-heat-flux literature, a high degree of overall correlation is evident.

  10. Flame Stabilization on Microscopic Scale of Wet Biogas with Microflame

    Science.gov (United States)

    Ida, Tamio; Fuchihata, Manabu; Mizuno, Satoru

    Harvesting, transportation, energy conversion and the high-efficient utilization, cascade method and market formation besides become with the indispensable element in order to utilize the biomass resource. There are two type biogases; it is gasified gas from dried biomass by partially combustion and wet biogas from wet biomass by methane fermentation, especially from the livestock excrement resources. This paper discusses an experimental study for flame stabilization on microscopic scale with wet biogas (mainly 0.6CH4+0.4CO2). In this study, the microflame with the wet biogas fuels are formed by the diffusion flame on the coppered straight pipes of inner diameter 0.02mm ˜ 1.5mm. This study is obtained stability mapping on microscopic scale of formed microflame by wet biogas fuels. The flame stability limit conditions on microscopic scale of wet biogas is drawn with blow off and extinction flame double limit lines. It is suggested that minimum mixing spatial scale change by the each mixing ratio of the wet biogas.

  11. Heat Transfer in Directional Water Transport Fabrics

    Directory of Open Access Journals (Sweden)

    Chao Zeng

    2016-10-01

    Full Text Available Directional water transport fabrics can proactively transfer moisture from the body. They show great potential in making sportswear and summer clothing. While moisture transfer has been previously reported, heat transfer in directional water transport fabrics has been little reported in research literature. In this study, a directional water transport fabric was prepared using an electrospraying technique and its heat transfer properties under dry and wet states were evaluated, and compared with untreated control fabric and the one pre-treated with NaOH. All the fabric samples showed similar heat transfer features in the dry state, and the equilibrium temperature in the dry state was higher than for the wet state. Wetting considerably enhanced the thermal conductivity of the fabrics. Our studies indicate that directional water transport treatment assists in moving water toward one side of the fabric, but has little effect on thermal transfer performance. This study may be useful for development of “smart” textiles for various applications.

  12. Modular Heat Exchanger With Integral Heat Pipe

    Science.gov (United States)

    Schreiber, Jeffrey G.

    1992-01-01

    Modular heat exchanger with integral heat pipe transports heat from source to Stirling engine. Alternative to heat exchangers depending on integrities of thousands of brazed joints, contains only 40 brazed tubes.

  13. Partial wetting gas-liquid segmented flow microreactor.

    Science.gov (United States)

    Kazemi Oskooei, S Ali; Sinton, David

    2010-07-07

    A microfluidic reactor strategy for reducing plug-to-plug transport in gas-liquid segmented flow microfluidic reactors is presented. The segmented flow is generated in a wetting portion of the chip that transitions downstream to a partially wetting reaction channel that serves to disconnect the liquid plugs. The resulting residence time distributions show little dependence on channel length, and over 60% narrowing in residence time distribution as compared to an otherwise similar reactor. This partial wetting strategy mitigates a central limitation (plug-to-plug dispersion) while preserving the many attractive features of gas-liquid segmented flow reactors.

  14. Wet combing for the eradication of head lice.

    Science.gov (United States)

    2013-03-01

    Manual removal (using conditioner and comb or a wet comb) can be used in the treatment of head lice. Head lice infestation (Pediculosis humanus capitis) is a common problem. It is diagnosed by visualising the lice. As half of people infested with head lice will not scratch, all people in contact with a person affected with head lice should be manually checked for infestations. Wet combing is easily and safely performed at home, but persistence is needed. This article describes the process of head lice removal using a wet comb. It has NHMRC Level 2 evidence of efficacy and no serious adverse effects have been reported.

  15. Modelling of wetting tests for a natural pyroclastic soil

    Directory of Open Access Journals (Sweden)

    Moscariello Mariagiovanna

    2016-01-01

    Full Text Available The so-called wetting-induced collapse is one of the most common problems associated with unsaturated soils. This paper applies the Modified Pastor-Zienkiewicz model (MPZ to analyse the wetting behaviour of undisturbed specimens of an unsaturated air-fall volcanic (pyroclastic soil originated from the explosive activity of the Somma-Vesuvius volcano (Southern Italy. Both standard oedometric tests, suction-controlled oedometeric tests and suction-controlled isotropic tests are considered. The results of the constitutive modelling show a satisfactory capability of the MPZ to simulate the variations of soil void ratio upon wetting, with negligible differences among the measured and the computed values.

  16. Wet gas compression. Experimental investigation of the aerodynamics within a centrifugal compressor exposed to wet gas

    Energy Technology Data Exchange (ETDEWEB)

    Gruener, Trond Gammelsaeter

    2012-07-01

    The demand for more efficient oil and gas production requires improved technology to increase production rates and enhance profitable operation. The centrifugal compressor is the key elements in the compression system. Preliminary studies of wet gas compressor concepts have demonstrated the benefits of wet gas boosting. An open-loop test facility was designed for single-stage wet gas compressor testing. Experimental investigators have been performed to reveal the impact of liquid on the aerodynamics of centrifugal compressor. The investigation consisted of two test campaigns with different impeller/diffuser configurations. Atmospheric air and water were used as experimental fluids. The two configurations showed a different pressure ratio characteristics when liquid as present. The results from test campaign A demonstrated a pronounced pressure ratio decrease at high flow and a minor pressure ration increase pressure ratio with reducing gas mass fraction (GMF). The deviation in pressure ratio characteristic for the two test campaigns was attributed to the volute operating characteristic. Both impeller/diffuser configurations demonstrated a reduction in maximum volume flow with decreasing GMF. The impeller pressure ratio was related to the diffuser and/or the volute performance). Air and water are preferable experimental fluids for safety reasons and because a less extensive facility design is required. An evaluation of the air/water tests versus hydrocarbon tests was performed in order to reveal whether the results were representative. Air/water tests at atmospheric conditions reproduced the general performance trend of hydrocarbon wet gas compressor tests with an analogous impeller at high pressures. Aerodynamic instability limits the operating range because of feasible severe damage of the compressor and adverse influence on the performance. It is essential to establish the surge margin at different operating conditions. A delayed instability inception was

  17. Exposures related to hand eczema

    DEFF Research Database (Denmark)

    Ibler, K.S.; Jemec, G.B.E.; Agner, T.

    2012-01-01

    Background. Hand eczema is common in healthcare workers, owing to intensive exposure to wet work and skin irritants. Targeted interventions and vocational guidance based on documented exposures and risk factors are needed. Objectives. The aims of the study were to investigate the relationship...... between exposures (domestic and at work) and prevalence and severity of hand eczema. Methods. Self-administered questionnaires were sent to 3181 healthcare workers in Denmark. Results. Two thousand two hundred and sixty-nine (71%) workers responded to the questionnaire. Frequent hand washing...... was significantly related to the presence of hand eczema. Having children hand eczema. A lower prevalence of hand eczema was found among those using moisturizers at work, and a higher prevalence was found among those using moisturizers at home...

  18. Evolution of Akaganeite in Rust Layers Formed on Steel Submitted to Wet/Dry Cyclic Tests

    Directory of Open Access Journals (Sweden)

    Haigang Xiao

    2017-11-01

    Full Text Available The evolution of akaganeite in rust layers strongly impacts the atmospheric corrosion behavior of steel during long-term exposure; however, the factors affecting the evolution of akaganeite and its mechanism of formation are vague. In this work, wet-dry cyclic corrosion tests were conducted to simulate long-term exposure. Quantitative X-ray diffraction analysis was employed to analyze variations in the relative amounts of akaganeite; scanning electron microscopy and electron probe microanalysis were used to study the migration of relevant elements in the rust layer, which could help elucidate the mechanism of akaganeite evolution. The results indicate that the fraction of akaganeite tends to decrease as the corrosion process proceeded, which is a result of the decrease in the amount of soluble chloride available and the ability of the thick rust layer to block the migration of relevant ions. This work also explores the location of akaganeite formation within the rust layer.

  19. Solvent content and dentin bond strengths using water-wet, ethanol-wet and deproteinization bonding techniques.

    Science.gov (United States)

    Faria-e-Silva, André Luis; Araújo, José Everton; Rocha, Gilliane Pereira; de Oliveira, Aline da Silva; de Moraes, Rafael Ratto

    2013-01-01

    To evaluate the impact of solvent content in two-step, etch-and-rinse adhesives on the dentin bond strengths obtained via water-wet, ethanol-wet or deproteinization techniques. A model photocurable Bis-GMA/HEMA blend was diluted in ethanol (7.5, 15 or 30 mass%) or acetone (15, 30 or 60 mass%) (low, medium or high solvent content, respectively). Viscosity of the solutions was measured with an oscillatory viscometer and data analyzed using ANOVA on Ranks (5%). Dentin bond strengths were evaluated using microshear bond test. After acid-etching and rinsing, the dentin was kept wet (water-wet), treated with ascending ethanol concentrations (ethanol-wet) or with 10% NaOCl solution (deproteinization). Composite cylinders built-up on the surfaces for the microshear test. Data from each bonding technique were submitted to two-way ANOVA and Fisher's LSD method (5%). Failure modes were classified under magnification and data analyzed using chi-square tests (5%). Viscosity of ethanol-based agents was remarkably higher than acetone solutions. For the water-wet technique, lower bond strength was observed for the low compared with medium and high ethanol contents. For the ethanol-wet technique, the bond strength for both solvents types was low dentin bond strengths for the conventional and ethanol bonding techniques.

  20. Analytical investigation of porous pin fins with variable section in fully-wet conditions

    Directory of Open Access Journals (Sweden)

    A. Vahabzadeh

    2015-03-01

    Full Text Available The present work investigates the temperature distribution, heat transfer rate, efficiency and optimization of porous pin fins in fully wet conditions. The thickness varies along the length of the fin and the lateral surface equation is defined as functions that include diversification fins (rectangular, triangular, convex parabolic and concave parabolic sections. Fins are made of aluminium and the tips of fins are insulated. Furthermore, it is assumed that the heat transfer coefficient depends on temperature and in the fin it changes according to temperature changes. In order to derivethe heat transfer equation, energy balance and Darcy model are used. After presenting the governing equation to obtain the temperature distribution, least squares method (LSM is applied. Comparison of the results between analytical solution and numerical outcome (fourth order Runge–Kutta method shows that LSM is a convenient and powerful method in engineering problems. Then the effects of various geometric and thermophysical parameters (power index for geometry (n, porosity, Biot number and relative humidity on the dimensionless temperature fin, efficiency and heat transfer rate are examined. Optimum design analysis was also carried out.

  1. Double blind placebo controlled exposure to molds

    DEFF Research Database (Denmark)

    Meyer, H W; Jensen, K A; Nielsen, K F

    2005-01-01

    The objective was to develop an experimental setup for human exposure to mold spores, and to study the clinical effect of this exposure in sensitive subjects who had previously experienced potentially building-related symptoms (BRS) at work. From three water-damaged schools eight employees....... In conclusion this is, to our knowledge, the first study to successfully conduct a human exposure to a highly controlled dose of fungal material aerosolized directly from wet building materials. This short-term exposure to high concentrations of two different molds induced no more reactions than exposure...... to placebo in eight sensitive school employees. However, a statistical type II error cannot be excluded because of the small sample size. PRACTICAL IMPLICATIONS: In this double blind, placebo controlled study of mold exposure changes in symptoms, objective measurements and blood samples were small and mostly...

  2. Solar heating and cooling system with absorption chiller and low temperature latent heat storage: Energetic performance and operational experience

    Energy Technology Data Exchange (ETDEWEB)

    Helm, M.; Keil, C.; Hiebler, S.; Mehling, H.; Schweigler, C. [Bavarian Center for Applied Energy Research (ZAE Bayern) (Germany)

    2009-06-15

    Absorption cooling systems based on water/lithium bromide (LiBr) solution typically require an open wet cooling tower to transfer the reject heat to the ambient. Yet, water consumption, the need for water make-up and cleaning, formation of fog, and the risk of Legionella bacteria growth are hindering factors for the implementation of small solar cooling systems. The application of a latent heat storage supporting the heat rejection of the absorption chiller in conjunction with a dry cooling system allows eliminating the wet cooling tower. By that means heat rejection of the chiller is shifted to periods with lower ambient temperatures, i.e. night time or off-peak hours. The system concept and the hydraulic scheme together with an analysis of the energetic performance of the system are presented, followed by a report on the operation of a first pilot installation. (author)

  3. Postfact phenomena of the wet-steam flow electrization in turbines

    Science.gov (United States)

    Tarelin, A. A.

    2017-11-01

    Physical processes occurring in a turbine with natural electrization of a humidity-steam flow and their effect on efficiency and reliability of the turbine operation has been considered. Causes of the electrical potential occurrence on a rotor shaft are analyzed. The wet steam's electrization exposure on the electrical potential that is one of the major factors of bearings' electroerosion has been demonstrated on the full-scale installation. Hydrogen formation in wheelspace of the turbine as a result of electrochemical processes and electric field exposure of the space charge has been considered. Hydrogen concentration dependence on a volume charge density in the steam flow has been determined. It is stated that the processes occurring behind the final stage of wet-steam turbines are similar to the ones in elaerosol ectrostatic generators. It has been demonstrated that this phenomenon causes the flow's temporal inhibition and starts pulsations. These factors' impact on power loss of the turbine has been evaluated and recommendations for their elimination have been offered. It has been determined that motions of charged drops can cause self-maintained discharges inside of the flow and between the flow and grounded surfaces that are accompanied by electromagnetic radiation of the wide spectrum. The integrated studies have shown that physical phenomena occurring due to natural electrization negatively affect efficiency and reliability of the turbine operation. Practical recommendations allowing one to minimize the negative effects of the flow natural electrization process have been offered.

  4. Heat convection

    Energy Technology Data Exchange (ETDEWEB)

    Jiji, L.M. [City Univ. of New York, NY (United States). Dept. of Mechanical Engineering

    2006-07-01

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

  5. Scrubber-Integrated Wet Electrostatic Precipitator; Skrubberintegrerat vaatt elektrofilter, WESP

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sven; Baefver, Linda; Davidsson, Kent; Pettersson, Jens; Schmidt, Hans; Strand, Michael; Yngvesson, Johan

    2011-07-01

    Combustion processes for heat and power production are an important source of sub-micron particle emissions, which cause enhanced health risks and premature deaths. To meet future requirements of economical and robust dust cleaning equipment, the Wet Electrostatic Precipitation (WESP) technology has been further developed in this project. A pilot scale slip stream WESP unit, installed by Goetaverken Miljoe, has been successfully installed and tested at the Renova Waste-to-Energy plant in Goeteborg, Sweden. The particles in the gas are charged by an ionizing electrode and collected in a concentric cylinder geometry. The WESP pilot consists of a unique combination of several existing technologies: it is integrated with a packed bed scrubber which means an ideally uniformly distributed gas flow in the WESP inlet. Furthermore, the WESP unit has a water cooled condensing collector, which facilitates continuous formation of a water film. The downward flowing water film transports the collected dust counter current to the upward flowing flue gas in order to minimize particle re-entrainment. The WESP is equipped with a high frequency transformer for stable voltage output and is fabricated in electrically conductive corrosion resistant Fibre Reinforced Plastic (FRP). The concentration of dust upstream of the WESP unit varied between 6.2 and 28 mg/Nm{sup 3} dry gas. All measured outlet dust concentrations were below 0.3 mg/Nm{sup 3} (dry gas, 11% O{sub 2}), which equals 3% of the applicable emission limit. The dust removal efficiency has been higher than 97% in all the dust measurements. The mean value of all the dust measurements was 15.2 mg/Nm{sup 3} upstream and 0.14 mg/Nm{sup 3} in downstream (both as dry gas, 11% O{sub 2}), which gives an average removal efficiency of slightly more than 99%. The removal efficiency increased with increasing inlet dust concentration, SO{sub 2} concentration and {Delta}T of the collector cooling. Chlorine, potassium, sodium, silicon and

  6. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign...

  7. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign (March,...

  8. The Geologic Evidence for a Warm and Wet Early Mars

    Science.gov (United States)

    Craddock, R. A.; Irwin, R. P.; Howard, A. D.; Morgan, A. M.

    2017-10-01

    The geologic evidence supporting a warm and wet climate on early Mars is presented. The case against an "icy highlands" scenario is also made. Climate models are converging to a solution, but any theoretical data must explain the empirical data.

  9. Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

    Science.gov (United States)

    Teverovsky, Alexander

    2017-01-01

    Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  10. Bioaccumulation of heavy metals in two wet retention ponds

    DEFF Research Database (Denmark)

    Søberg, Laila C.; Vollertsen, Jes; Blecken, Godecke-Tobias

    2016-01-01

    Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem servicing function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout...

  11. ROE Wet Sulfate Deposition Raster 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  12. In silico and wet lab approaches to study transcriptional regulation

    NARCIS (Netherlands)

    Hestand, Matthew Scott

    2010-01-01

    Gene expression is a complicated process with multiple types of regulation, including binding of proteins termed transcription factors. This thesis looks at transcription factors and transcription factor binding site discovery through computational predictions and wet lab work to better elucidate

  13. Wet-aerosol leakage through simulated containment leak paths

    Energy Technology Data Exchange (ETDEWEB)

    Sutradhar, S.C. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2007-07-01

    Some types of postulated accidents in a nuclear reactor can result in the formation of radioactive wet aerosols in containment and their subsequent release into the environment. Wet-aerosol leakage was investigated using simulated leak paths for isolation damper valves and airlock door seals. Leakage was calculated from measured uranine concentrations deposited on high-quality filters positioned downstream of the simulated leak paths. Test results indicated that a small fraction of wet aerosols leaked through the simulated isolation damper valves, whereas a large fraction leaked through the simulated airlock door seals. Data on wet-aerosol leakage through containment leak paths are needed to develop and validate models in safety analysis codes. (author)

  14. Combined wet oxidation and alkaline hydrolysis of polyvinylchloride

    DEFF Research Database (Denmark)

    Sørensen, E.; Bjerre, A.B.

    1992-01-01

    In view of the widespread aversion to burning polyvinylchloride (PVC) together with municipal waste, we have attempted an alternative approach to its decomposition. This paper describes a combined wet oxidation/alkaline hydrolysis yielding water soluble, biodegradable products. Experiments were...

  15. Simulations of tropical rainforest albedo: is canopy wetness important?

    National Research Council Canada - National Science Library

    Silvia N.M. Yanagi; Marcos H. Costa

    2011-01-01

    .... Therefore, it was investigated the role of canopy wetness on the simulated albedo of a tropical rainforest by modifying the IBIS canopy radiation transfer code to incorporate the effects of canopy...

  16. The Forensic and Legal Implications of Water, Wet, or Fry

    National Research Council Canada - National Science Library

    Susan M. Chlebowski; Cecilia Leonard

    2012-01-01

    ...), has several names, such as water, wet, illy, and fry. Individuals who commit crimes under the influence of this substance are often violent and may appear psychotic, with symptoms resembling schizophrenia or delirium...

  17. Characterization of silver nanoparticles prepared by wet chemical ...

    African Journals Online (AJOL)

    Characterization of silver nanoparticles prepared by wet chemical method and their antibacterial and cytotoxicity activities. Manal A Awad, Awatif A Hendi, Khalid MO Ortashi, Reem A Alotaibi, Maha Sh Sharafeldin ...

  18. Regulated wet nursing: managed care or organized crime?

    National Research Council Canada - National Science Library

    Obladen, Michael

    2012-01-01

    .... When artificial feeding lost its threat thanks to sewage disposal, improved plumbing, the introduction of rubber teats, cooling facilities and commercial formula, wet nursing declined towards the end of the 19th century.

  19. SAFARI 2000 Leaf Spectral Measurements, Kalahari Transect, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The Boston University team collected several data sets along the Kalahari Transect during the SAFARI 2000 wet season field campaign between March 3 and...

  20. SAFARI 2000 Leaf Spectral Measurements, Kalahari Transect, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — The Boston University team collected several data sets along the Kalahari Transect during the SAFARI 2000 wet season field campaign between March 3 and March 18,...

  1. A new advanced experimental setup for in-depth study of the interfacial reaction during reactive wetting.

    Science.gov (United States)

    Frenznick, Sascha; Stratmann, Martin; Rohwerder, Michael

    2008-04-01

    Reactive wetting plays a crucial role in many technical processes, from soldering in microelectronics, production of metal/ceramic composites, to hot dip galvanizing in mass production of zinc coated steel sheet. In all these cases the wetting behavior of metal melts on different surfaces plays a crucial role in material joining and coating. In all these processes the formation of the interfacial reaction layer has to occur within as short a time as possible in order to ensure a fast overall production speed. As the interfacial layer determines the stability of the formed composites, detailed knowledge of its growth mechanisms is required for a directed process optimization. However, the investigation of the processes occurring at the buried interface between substrate and wetting phase is difficult, especially for the case of liquid metal wetting metallic or ceramic solid substrates at high temperatures. Here, a novel advanced technique for the investigation of high temperature wetting processes up to a temperature of 1100 K is presented. It is based on the sessile drop technique but, in addition, allows spinning off the droplet at any chosen wetting time, thus providing direct access to the interfacial reaction layer. Since the experimental setup is integrated into a UHV compatible reaction chamber, not only excellent control of the composition of the atmosphere is ensured, but also direct transfer to surface analytical tools such as scanning electron microscope or electron spectroscopy for chemical analysis without intermediate exposure to air is realized. As will be shown for the case of hot dip galvanising of steel, this is an outstanding advance compared to existing methods.

  2. Advance of Wetting Front in Silt Loam Soil

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmood

    2013-04-01

    Full Text Available Under drip irrigation , the plant's root is concentrated inside the wetted bulb (region. Thus, the development of these roots and the plant production are greatly affected by the wetting pattern. Therefore, the wetting pattern of soil under drip irrigation must be taken into consideration in the design of drip irrigation system for both single dripping source or multi-overlapping wetting patterns of dripping water sources.2The aim of this study is to evaluate the effect of initial water content of the soil and spacing between two adjacent dripping sources with different flow rate on the movement of the wetting front.This study included 16 tests for monitoring the advancement of the wetting front with time during and after the water application phase. The water advance and water distribution measurement are carried out for two cases of the soil profile: for the first case with initial volumetric water content of 4.08% and for the second case with initial volumetric water content of 12.24%. Two spacing between the emitter were tested 25cm and 50 cm using application flow rates of 0.606, 1.212, 1.818, and 2.424 cm3 /min/cm to show the combined effect of spacing and flow rate on the performance of two adjacent emitter.The study proposed a method for determining the spacing between the two emitting sources , the water application rate and watering time. The proposed method depends on a wetted zone whose depth is equal to the root zone depth with a values equals to the maximum vertical advance of the wetting front underneath the drip line at time when this depth is equal to the depth of wetting at mid­point between the drip line. the study revealed that both the vertical water advance in soil underneath the emitter and the horizontal advance of the wetting front is larger than those in the case of single emitter.Furthermore, the vertical water advance increases with the decrease spacing between the two drip lines. Also, the horizontal advance of the

  3. Landfill Mining - Wet mechanical treatment of fine MSW with a wet jigger.

    Science.gov (United States)

    Wanka, Sebastian; Münnich, Kai; Fricke, Klaus

    2017-01-01

    The motives for landfill mining are various. In the last couple of years Enhanced Landfill Mining (ELFM) has become increasingly important in academic discourse and practical implementation. The main goal of ELFM is to recover as much material as possible from deposited municipal solid waste (MSW). In most of the projects carried out so far, the main focus has been set on coarse materials such as plastics, woods, papers and metals. These fractions can be separated easily by sieving in combination with magnetic separation. In these projects most of the fine materials, which might represent as much as 60-70% of the total mass of the landfill body, had to be deposited again. A further treatment aiming at reducing the masses of these fine materials, which are still a conglomerate of soil, calorific fractions, metals, minerals and residues, usually did not take place. One topic in the framework of the landfill mining project TÖNSLM, in addition to the separation of the calorific fraction and metals has been the treatment of fine materials with the goal to re-use these e.g. for construction purposes. This paper shows the results obtained after the wet mechanical treatment of fine MSW 10-60mm with a wet jigger. The physical principle of this process is the separation of the mass flux due to the different densities of the waste constituents. As a result, three main waste fluxes are obtained: Dense inert and dense fine fraction with a high content of minerals and a lightweight fraction with a high calorific value between 16 and 20MJ/kg. An additional positive effect of wet mechanical treatment is the removal of the finest particles from the surface of the waste material, thus increasing the quality of the generated waste fluxes. The mass fluxes of the different fractions and their qualities as well as possible recovery paths are described below. An economical and ecological consideration of the treatment of the fine materials does not take place within the framework of

  4. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... for signs of heat stroke or exhaustion. Heat Stroke and Exhaustion Symptoms of early heat exhaustion symptoms ... heavy sweating; nausea; and giddiness. Symptoms of heat stroke (late stage of heat illness) include flushed, hot, ...

  5. Renewable Heating and Cooling

    Science.gov (United States)

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

  6. Exertional Heat Illnesses and Environmental Conditions During High School Football Practices.

    Science.gov (United States)

    Tripp, Brady L; Eberman, Lindsey E; Smith, Michael Seth

    2015-10-01

    Guidelines for preventing exertional heat illnesses (EHIs) during extreme heat stress should be specific to regional environments, age, and sport and should be based on evidence of reducing the risk. Each year in the United States, over 1 million high school football players practice in the August heat; however, no published data describe the incidence of EHIs in these athletes. To describe the environmental conditions and incidence of EHIs during high school football practices over a 3-month period. Descriptive epidemiology study. For a 3-month period (August-October), athletic trainers at 12 high schools in North Central Florida recorded the practice time and length, environmental conditions (wet-bulb globe temperature), and incidences of EHIs in varsity football athletes. Athletes suffered 57 total EHIs during 29,759 athlete-exposures (AEs) for the 3-month data collection period (rate = 1.92/1000 AEs). August accounted for the majority of all EHIs, with 82.5% (47/57) and the highest rate (4.35/1000 AEs). Of total heat illnesses, heat cramps accounted for 70.2% (40/57), heat exhaustion 22.8% (13/57), and heat syncope 7.0% (4/57). The odds ratio indicated that athletes in August practices that lasted longer than the recommended 3 hours were 9.84 times more likely to suffer a heat illness than those in practices lasting ≤3 hours. The highest rate of EHIs was during August. Practices in August that exceeded the recommended 3 hours were associated with a greater risk of heat illnesses. The overall rate of EHIs was lower for the high school football athletes observed in the study compared with that reported for collegiate football athletes in the region. The low rates of EHIs recorded suggest that the prevention guidelines employed by sports medicine teams are appropriate for the region and population. Team physicians and athletic trainers should employ evidence-based, region- and population-specific EHI prevention guidelines. Sports medicine teams, coaches, and

  7. Surface Tension Triggered Wetting and Point of Care Sensor Design.

    Science.gov (United States)

    Falde, Eric J; Yohe, Stefan T; Grinstaff, Mark W

    2015-08-05

    Rapid, simple, and inexpensive point-of-care (POC) medical tests are of significant need around the world. The transition between nonwetting and wetted states is used to create instrument-free surface tension sensors for POC diagnosis, using a layered electrospun mesh with incorporated dye to change color upon wetting. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Evaluation of the effectiveness of coal and mine dust wetting

    Directory of Open Access Journals (Sweden)

    Krzysztof Cybulski

    2015-01-01

    This paper presents a method to evaluate the effectiveness of coal or mine dust's moistening conducted with the use of water solutions of wetting agents in order to deprive the dust of its volatility, is based on the method of measurement of time of complete moistening of that dust's one-gram samples with the use of “pure” water or water solutions of the particular wetting agent.

  9. Modeling Reactive Wetting when Inertial Effects are Dominant

    OpenAIRE

    Wheeler, Daniel; Warren, James A.; Boettinger, William J.

    2010-01-01

    Recent experimental studies of molten metal droplets wetting high temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper investigates wetting and spreading on reactive substrates when inertial effects are dominant using a thermodynamically derived, diffuse interface model of a binary, three-phase material. The liquid-vapor transition is modeled using a van der Waals diffuse inter...

  10. [Hemicorporectomy with double barreled wet colostomy: an extremely rare procedure].

    Science.gov (United States)

    Ricci, Marco Antonio; Duarte, Enio Lucio Coelho; Souza, Renato Costa Amaral; Albuquerque-Peres, Carlos Michel; Guimaraes, Gustavo Cardoso; Lopes, Ademar

    2009-12-01

    The Hemicorporectomy associated to Double-barreled wet colostomy is a high complex and heroic procedure and is to be used only exceptionally, when it is the last resource for treating locally advanced pelvic diseases in the absence of evidences of distant metastasis. We retrospectively analyzed the surgical technical details and the results from a hemicorporectomy with double-barreled wet colostomy in a single surgical time in a case of epidermoide carcinoma from a coetaneous pressure ulcer.

  11. Wet Deposition Concentrations and Fluxes of Mercury in Taiwan

    Science.gov (United States)

    Sheu, G.; Lin, N.

    2010-12-01

    Taiwan is located downwind to the largest anthropogenic Hg emission source region, the East Asian continent, and thus model simulations often predicted that Taiwan could receive high Hg input via wet deposition. Therefore, a mercury (Hg) wet deposition monitoring network was established in Taiwan to collect rainwater for total Hg analysis since September 2008. The objective of this network is to establish a national database of wet deposition concentrations and fluxes of Hg. This database will later be used to develop information on spatial and temporal trends in Hg wet deposition and to evaluate the contribution of regional/long-range transport. A total of 12 sampling sites, covering urban, rural, mountain, coastal and remote island areas, were set up. Weekly samples were collected using automated wet-only precipitation collection systems. Acid-cleaned glass funnels were used for rainwater collections and samples were collected into acid-cleaned 1L Teflon bottles. Samples were retrieved and sampling trains were changed every Tuesday morning. Total Hg was quantified by dual amalgamation CVAFS after BrCl oxidation, NH2OH●HCl neutralization, and SnCl2 reduction. In 2009, total Hg concentrations of all the rainwater samples ranged from 2.1 to 82.2 ng/L. Volume-weighted mean (VWM) total Hg concentrations of all the sampling sites ranged between 7.6 and 17.2 ng/L. In general, rainwater Hg concentrations were lower in northern Taiwan sites, likely due to the dilution effect caused by higher rainfall amount. Annual wet depositional Hg fluxes ranged between 12.3 and 37.0 μg/m2 in 2009, with higher values usually observed in northern Taiwan sites. The geographical distribution of wet depositional Hg flux mimicked the distribution of accumulative rainfall amount, suggesting precipitation depth is the primary factor in determining the magnitude of wet depositional Hg flux.

  12. Development of Wet Noodles Based on Cassava Flour

    OpenAIRE

    Abidin, Akhmad Z; Devi, Cinantya; Adeline, A

    2013-01-01

    Cassava is one of Indonesia’s original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing c...

  13. Microbial community composition of transiently wetted Antarctic Dry Valley soils

    Directory of Open Access Journals (Sweden)

    Thomas D. Neiderberger

    2015-01-01

    Full Text Available During the summer months, wet (hyporheic soils associated with ephemeral streams and lake edges in the Antarctic Dry Valleys (DV become hotspots of biological activity and are hypothesized to be an important source of carbon and nitrogen for arid DV soils. Recent research in the DV has focused on the geochemistry and microbial ecology of lakes and arid soils, with substantially less information being available on hyporheic soils. Here we determined the unique properties of hyporheic microbial communities, resolved their relationship to environmental parameters and to compared them to archetypal arid DV soils. Generally, pH increased and chlorophyll a concentrations decreased along transects from wet to arid soils (9.0 to ~7.0 for pH and ~0.8 to ~ 5 µg/cm3 for chlorophyll a, respectively. Soil water content decreased to below ~3% in the arid soils. Community fingerprinting-based principle component analyses revealed that bacterial communities formed distinct clusters specific to arid and wet soils; however, eukaryotic communities that clustered together did not have similar soil moisture content nor did they group together based on sampling location. Collectively, rRNA pyrosequencing indicated a considerably higher abundance of Cyanobacteria in wet soils and a higher abundance of Acidobacterial, Actinobacterial, Deinococcus/Thermus, Bacteroidetes, Firmicutes, Gemmatimonadetes, Nitrospira and Planctomycetes in arid soils. The two most significant differences at the genus level were Gillisia signatures present in arid soils and chloroplast signatures related to Streptophyta that were common in wet soils. Fungal dominance was observed in arid soils and Viridplantae were more common in wet soils. This research represents an in-depth characterization of microbial communities inhabiting wet DV soils. Results indicate that the repeated wetting of hyporheic zones has a profound impact on the bacterial and eukaryotic communities inhabiting in these areas.

  14. Hijama (Wet Cupping or Dry Cupping) for Diabetes Treatment

    OpenAIRE

    Vakilinia, Seyed Reza; Bayat, Davood; Asghari, Majid

    2016-01-01

    Background: Diabetes is known as one of the most common diseases in the world and its treatment is one of the most important healthcare issues. Consequently, different treatment methods of complementary medicine and recent medicine have been used by scientific communities to control and predict the disease. This article considered the effects of dry cupping and wet cupping, based on traditional medicine and recent studies. Methods: At first, the benefits of dry cupping and wet cupping were ta...

  15. Human skin wetness perception: psychophysical and neurophysiological bases

    Science.gov (United States)

    Filingeri, Davide; Havenith, George

    2015-01-01

    The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

  16. Assessment of a dry and a wet route for the production of biofuels from microalgae: energy balance analysis.

    Science.gov (United States)

    Xu, Lixian; Wim Brilman, Derk W F; Withag, Jan A M; Brem, Gerrit; Kersten, Sascha

    2011-04-01

    In this study, the energy balance of two microalgae-to-biofuel concepts, one via a so called "dry route" (oil extraction from dried algae) and one via a "wet route" (oil extraction in the water phase), are assessed. Both routes are intended to convert the chemical energy contained in the microalgae into high-value biofuels with minimal fossil energy consumption. The analysis shows that the drying process in the dry route and the oil extraction process in the wet route consume a significant amount of energy. By coupling waste heat from a nearby power plant to the process, the energy balance can be improved and a potential fossil energy ratio (FER) up to 2.38 and 1.82 can be reached for the dry and wet route, respectively. The results indicate that based on current available technologies, the dry route has higher FER and the wet route has more potential in producing high valuable biofuels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Diagnosing the Role of Transpiration in the Transition from Dry to Wet Season Over the Amazon Using Satellite Observations

    Science.gov (United States)

    Wright, J. S.; Fu, R.; Yin, L.; Chae, J.

    2013-12-01

    Reanalysis data indicates that land surface evapotranspiration plays a key role in determining the timing of wet season onset over the Amazon. Here, we use satellite observations of water vapor and its stable isotopes, carbon dioxide, leaf area index, and precipitation together with reanalysis data to explore the importance of transpiration in initiating the transition from dry season to wet season over the Amazon. The growth of vegetation in this region is primarily limited by the availability of sunlight rather than the availability of soil moisture, so that the increase of solar radiation during the dry season coincides with dramatic increases in leaf area index within forested ecosystems. This period of plant growth is accompanied by uptake of carbon dioxide and enrichment of heavy isotopes in water vapor, particularly near the land surface. Reanalysis data indicate that this pre-wet season enrichment of HDO is accompanied by sharp increases in the surface latent heat flux, which eventually triggers sporadic moist convection. The transport of transpiration-enriched near-surface air by this convection causes a dramatic increase in free-tropospheric HDO in late August and September. September also marks transition points in the annual cycles of leaf area index (maximum) and carbon dioxide (minimum). The increase in convective activity during this period creates convergence, enhancing moisture transport into the region and initiating the wet season.

  18. Changes in hydroxyapatite powder properties via heat treatment

    Indian Academy of Sciences (India)

    The properties of hydroxyaptite (HA) powder, especially its physical one, are largely influenced by the heat treatment process. Controlling of these changes is vital in deciding the suitability of applying this powder in wet processing routes for green body fabrication. Chemically, the crystallinity of the HA powder was found to ...

  19. Hijama (Wet Cupping or Dry Cupping) for Diabetes Treatment.

    Science.gov (United States)

    Vakilinia, Seyed Reza; Bayat, Davood; Asghari, Majid

    2016-05-01

    Diabetes is known as one of the most common diseases in the world and its treatment is one of the most important healthcare issues. Consequently, different treatment methods of complementary medicine and recent medicine have been used by scientific communities to control and predict the disease. This article considered the effects of dry cupping and wet cupping, based on traditional medicine and recent studies. At first, the benefits of dry cupping and wet cupping were taken from some original books of Iranian traditional medicine, such as Canon of Medicine, Kholasat-al-hekma, Tib-e-Akbari and Exir-e-Azam. Then, the information about scientific articles was obtained by studying some of the Iranian traditional medicine journals and searching through PubMed, SID and Google Scholar. In traditional medicine, Hijama is divided into two kinds, namely wet cupping (with sharat, with incision, and blood giving) and dry cupping (without sharat, without incision). Dry cupping causes organ blood absorption, organ warming, and loss of organ humidity. The texts of Iranian traditional medicine refer to the Ziabites disease that its symptoms are like diabetes. This disease is divided into two types including warm and cold ziabetes. The treatments that are recommended for both types are dry cupping for cold ziabetes and wet cupping for warm ziabetes. In addition, according to scientific studies, dry cupping and wet cupping have been recommended for diabetes treatment. Dry cupping and wet cupping can be introduced as the complementary treatment methods beside other treatment methods.

  20. Development of Wet Noodles Based on Cassava Flour

    Directory of Open Access Journals (Sweden)

    Akhmad Z. Abidin

    2013-04-01

    Full Text Available Cassava is one of Indonesia’s original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing cassava flour-based wet noodles. The best result was then examined for its nutritional value, economical value, and market response, and also a comparison was made between the prepared wet noodles and the standard noodles made from wheat flour. The analysis was based on five characteristics: taste, texture, chewiness, aroma, and appearance. Relations between these characteristics with composition, materials used, and methods applied are discussed. The developed cassava flour-based wet noodle meets physical, nutritional, and economical standards. Raw materials of the noodle were cassava flour and a wheat flour composite with a 5:1 ratio, egg, gluten, soda-ash, water, and vegetable oil, while the process was completed in multiple stages. Market response showed that the cassava flour-based wet noodles were 80% similar to wheat-flour noodles.

  1. Evaluation of the Acidic Wet Deposition Predictions of CMAQ

    Science.gov (United States)

    Dennis, R. L.

    2002-05-01

    Acidic deposition is coming back into importance as part of more encompassing multi-pollutant thinking. Acidic and nutrient deposition is an important component of new multi-pollutant legislation being considered by the Administration. The Community Multiscale Air Quality model, CMAQ, was designed to handle multiple pollutants in a one-atmosphere context. Much of the initial evaluation of CMAQ was directed at the criteria pollutants. CMAQ's predictions of acidic deposition also need to be evaluated, not only because of the importance of deposition but also because deposition sets the lifetime of fine particles in the atmosphere. The controlling deposition is wet deposition, hence, we consider it first. We compare wet deposition for selected months throughout 1990, showing that CMAQ captures the main features of seasonality. We note that the previous problem of overprediction of winter wet deposition associated with the RADM cloud parameterization has been addressed through explicit recognition of icy cloud water. We are still plagued by the difficulty of meteorological models to predict precipitation as input to chemical transport models which produces additional scatter. Interestingly, there is a consistent differential between sulfate and nitrate wet deposition, with nitrate wet deposition being slightly lower. We explore several hypotheses for this behavior, including the hypothesis that this is more an issue of mixing than an issue of cloud chemistry. In general, CMAQ appears to be producing reasonable predictions that demonstrate an improvement in our ability to predict wet deposition, although there is room for improvement.

  2. Infrared heating

    Science.gov (United States)

    IR heating was first industrially used in the 1930s for automotive curing applications and rapidly became a widely applied technology in the manufacturing industry. Contrarily, a slower pace in the development of IR technologies for processing foods and agricultural products was observed, due to lim...

  3. Charring rate of wood exposed to a constant heat flux

    Science.gov (United States)

    R. H. White; H. C. Tran

    1996-01-01

    A critical factor in the fire endurance of a wood member is its rate of charring. Most available charring rate data have been obtained using the time-temperature curves of the standard fire resistance tests (ASTM E 119 and ISO 834) to define the fire exposure. The increased use of heat release calorimeters using exposures of constant heat flux levels has broadened the...

  4. Biomimetic wet-stable fibres via wet spinning and diacid-based crosslinking of collagen triple helices

    CERN Document Server

    Arafat, M Tarik; Yin, Jie; Wood, David J; Russell, Stephen J

    2015-01-01

    One of the limitations of electrospun collagen as bone-like fibrous structure is the potential collagen triple helix denaturation in the fibre state and the corresponding inadequate wet stability even after crosslinking. Here, we have demonstrated the feasibility of accomplishing wet-stable fibres by wet spinning and diacid-based crosslinking of collagen triple helices, whereby fibre ability to act as bone-mimicking mineralisation system has also been explored. Circular dichroism (CD) demonstrated nearly complete triple helix retention in resulting wet-spun fibres, and the corresponding chemically crosslinked fibres successfully preserved their fibrous morphology following 1-week incubation in phosphate buffer solution (PBS). The presented novel diacid-based crosslinking route imparted superior tensile modulus and strength to the resulting fibres indicating that covalent functionalization of distant collagen molecules is unlikely to be accomplished by current state-of-the-art carbodiimide-based crosslinking. ...

  5. Visual wetness perception based on image color statistics.

    Science.gov (United States)

    Sawayama, Masataka; Adelson, Edward H; Nishida, Shin'ya

    2017-05-01

    Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene.

  6. Identification of Potential Strain Heterogeneities During Wetting-Induced Compaction

    Directory of Open Access Journals (Sweden)

    Mihalache Constance

    2016-01-01

    Full Text Available Compaction upon wetting has been reported to occur in various types of unsaturated soils with damaging consequences for infrastructure in field applications. This deformation process is often referred to as “wetting-collapse”, implying that it may be unstable in nature. Recent evidences also indicate that compaction localization represents a possible mode of deformation during wetting, even in the presence of oedometric loading paths. Despite this, little work has been done from a mechanistic perspective to assess the susceptibility of these processes to localization instability. Here we assess the potential for strain localization during wetting through controllability analyses defined in light of a second-order work expression for unsaturated soils. A hydro-mechanical constitutive model with suction-dependent hardening is used to simulate classic experimental data, and the controllability criteria are specialized to capture the potential for shear band formation for a range of band inclinations under water content-controlled and suction-controlled wetting paths. The effect of changes in material characteristics was evaluated, showing that the potential for strain localization upon water-injection increases with increasing values of suction-induced hardening, and that non-associativity may have an effect on both the potential for localization under rapid wetting, as well as on the range of band angles over which it may occur. Specifically, it is possible to distinguish two well-defined stress regions, one within which strain localization is first possible with horizontal band inclinations and another in which inclined localization zones tend to be more critical. Such results provide insight on the factors that may contribute to strain localization during wetting and find general applicability in the interpretation of the response of geo-structures subjected to intense hydrologic forcing.

  7. The effect of surface water and wetting on gecko adhesion.

    Science.gov (United States)

    Stark, Alyssa Y; Sullivan, Timothy W; Niewiarowski, Peter H

    2012-09-01

    Despite profound interest in the mechanics and performance of the gecko adhesive system, relatively few studies have focused on performance under conditions that are ecologically relevant to the natural habitats of geckos. Because geckos are likely to encounter surfaces that are wet, we used shear force adhesion measurements to examine the effect of surface water and toe pad wetting on the whole-animal performance of a tropical-dwelling gecko (Gekko gecko). To test the effect of surface wetting, we measured the shear adhesive force of geckos on three substrate conditions: dry glass, glass misted with water droplets and glass fully submerged in water. We also investigated the effect of wetting on the adhesive toe pad by soaking the toe pads prior to testing. Finally, we tested for repeatability of the adhesive system in each wetting condition by measuring shear adhesion after each step a gecko made under treatment conditions. Wetted toe pads had significantly lower shear adhesive force in all treatments (0.86 ± 0.09 N) than the control (17.96 ± 3.42 N), as did full immersion in water (0.44 ± 0.03 N). Treatments with droplets of water distributed across the surface were more variable and did not differ from treatments where the surface was dry (4.72 ± 1.59 N misted glass; 9.76 ± 2.81 N dry glass), except after the gecko took multiple steps. These findings suggest that surface water and the wetting of a gecko's adhesive toe pads may have significant consequences for the ecology and behavior of geckos living in tropical environments.

  8. SAFARI 2000 Kalahari Transect CO2, Water Vapor, and Heat Flux, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Short-term measurements of carbon dioxide, water, and energy fluxes were collected at four locations along a mean annual precipitation gradient in southern Africa...

  9. SAFARI 2000 Kalahari Transect CO2, Water Vapor, and Heat Flux, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Short-term measurements of carbon dioxide, water, and energy fluxes were collected at four locations along a mean annual precipitation gradient in southern...

  10. Heat pump

    OpenAIRE

    Klíma, Martin

    2010-01-01

    Bakalářská práce popisuje a charakterizuje tepelné čerpadlo. Obsahuje souhrn jednotlivých druhů tepelných čerpadel z hlediska získávání energie, princip jejich funkce a popis odlišností mezi jednotlivými druhy kompresorů, použití pracovní látky a její vývin do budoucna. Závěrem je zde uveden můj vlastní názor na tepelné čerpadlo, které bych preferoval. Bachelor thesis describes and characterizes the heat pump. Summarizes the various types of heat pumps in terms of energy production, princi...

  11. Discrepancy of whiteness and UV protection in wet state.

    Science.gov (United States)

    Tarbuk, Anita; Grancarić, Ana Marija; Situm, Mirna

    2014-12-01

    The incidence of skin cancer is increasing by epidemic proportions. Basal cell cancer remains the most common skin neoplasm, and simple excision is generally curative. On the other hand, aggressive local growth and metastasis are common features of malignant melanoma, which accounts for 75 percent of all deaths associated with skin cancer. In Croatia only, more than 20,000 new cases of skin cancer has been diagnosed in 2008 of which melanoma 286 new cases and 118 yearly deaths in men, and 275 new cases and 79 deaths in women population. The back sides in men and women, as well as the lower limbs in women, are the most common site for melanomas. The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet (UV) radiation crossed with the amount of skin pigmentation in the population. There are indications that other parts of solar spectrum (e.g., blue light) might also have effects on skin and eyes. Most people think all clothing will protect them, but that's not the case. UV clothing can show UVprotection, but in the most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such are type of fiber, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA), UV-B protective agents, as well as nanoparticles, if applied. For that reason, jeans and tightly woven fabrics offer a very good level of protection. However, on a hot summer day, those aren't the kinds of clothing people usually reach for. More often, when they are on the beach, they wear T-shirt, as well during the swimming in the sea, thinking that it will protect them. Therefore, in this paper the discrepancy of UVprotection in wet state was researched. For the purpose, FWA and UVabsorber were applied in wide concentration range to white cotton knit fabrics commonly used for T-shirts. Afterwards, the discrepancy in whiteness and UVprotection was research in distilled water

  12. Heat Exchange

    OpenAIRE

    Bottomley, Stephen

    2012-01-01

    Heat Exchange’ is an international touring exhibition of enamel metalwork curated by Turrell.E (UK), Gegenwart (Germany/UK) and Cameron (Australia). Bottomley was one of twenty-three international artists invited to join a transcontinental on-line blog and forum that recorded individual contemporary approaches to working with vitreous enamel the year prior to the 2012 exhibition that coincided with the SNAG (Society of North American Goldsmiths) National Conference in Phoenix Arizona USA.Vitr...

  13. Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Li

    2011-05-04

    In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

  14. Heat pump system

    Science.gov (United States)

    Swenson, Paul F.; Moore, Paul B.

    1979-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchangers and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  15. The Effect of Air Velocity on the Prevention of Heat Stress in Iranian Veiled Females

    Directory of Open Access Journals (Sweden)

    Habibi

    2016-09-01

    Full Text Available Background Some environmental factors such as the ambient temperature, radiant temperature, humidity and air velocity as well as clothing and activity level are effective to induce heat strain on the workers. Objectives The current study aimed to evaluate the effect of air velocity on Iranian veiled females at various exercise intensities and climatic conditions. Methods The current experimental study was conducted on 51 healthy veiled females with Islamic clothing (n = 30 in two hot-dry climatic chambers (wet-bulb globe temperature (WBGT = 32 ± 0.1°C and WBGT = 30 ± 0.1°C, 40% relative humidity (RH without air velocity and (n = 21 with air velocity 0.31 m/s in sitting and light workload conditions, respectively, for 60 minutes. The WBGT, oral temperature and heart rate were measured simultaneously every five minutes during the heat exposure and resting state. Data were analyzed using correlation and line regression by SPSS ver. 16. Results In both groups, oral temperature and heart rate increased during heat exposure. The increase of oral temperature and heart rate were larger in the group with air velocity (sitting position, 37.05 ± 0.20°C, 98.30 ± 7.79 bpm, light workload, 37.34 ± 0.24°C, 124.08 ± 6.09 bpm compared those of the group without air velocity (sitting position, 36.70 ± 0.36°C, 69.74 ± 0.98 bpm, light workload, 36.71 ± 0.27°C, 110.78 ± 17.9 bpm. The difference in physiological strain index (PSI between resting and low workload were higher in with air velocity group than those of the group without air velocity. Conclusions The results showed that the heat stress increased by increasing air velocity and humidity in both groups. The air velocity with high humidity can be considered as a positive factor in the occurrence of heat strain. Therefore, the incidence of heat stress decreases with the increase of humidity and reduction of air velocity or with increase of air velocity and reduction of humidity in Iranian veiled

  16. Physicochemical properties and combustion behavior of duckweed during wet torrefaction.

    Science.gov (United States)

    Zhang, Shuping; Chen, Tao; Li, Wan; Dong, Qing; Xiong, Yuanquan

    2016-10-01

    Wet torrefaction of duckweed was carried out in the temperature range of 130-250°C to evaluate the effects on physicochemical properties and combustion behavior. The physicochemical properties of duckweed samples were investigated by ultimate analysis, proximate analysis, FTIR, XRD and SEM techniques. It was found that wet torrefaction improved the fuel characteristics of duckweed samples resulting from the increase in fixed carbon content, HHVs and the decrease in nitrogen and sulfur content and atomic ratios of O/C and H/C. It can be seen from the results of FTIR, XRD and SEM analyses that the dehydration, decarboxylation, solid-solid conversion, and condensation polymerization reactions were underwent during wet torrefaction. In addition, the results of thermogravimetric analysis (TGA) in air indicated that wet torrefaction resulted in significant changes on combustion behavior and combustion kinetics parameters. Duckweed samples after wet torrefaction behaved more char-like and gave better combustion characteristics than raw sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, Søren

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full-scale exper......This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full...... degree of desulphuri-sation and absorber pH profile for the two limestone types using a holding tank pH of 5.5, but the residual limestone in the gypsum was significantly lower for the chalk. Furthermore, simulations showed that between 10 and 30 % of the limestone dissolves in the absorber de......-pending on the process conditions. A typical holding tank pH of 5-5.5 (also used in full-scale wet FGD packed towers) was found to be a reasonable compromise between residual lime-stone in the gypsum and the degree of desulphurisation. Simulations were only slightly sensi-tive to the temperature in the interval 313...

  18. Thermal Performance for Wet Cooling Tower with Different Layout Patterns of Fillings under Typical Crosswind Conditions

    Directory of Open Access Journals (Sweden)

    Ming Gao

    2017-01-01

    Full Text Available A thermal-state model experimental study was performed in lab to investigate the thermal performance of a wet cooling tower with different kinds of filling layout patterns under windless and 0.4 m/s crosswind conditions. In this paper, the contrast analysis was focused on comparing a uniform layout pattern and one kind of optimal non-uniform layout pattern when the environmental crosswind speed is 0 m/s and 0.4 m/s. The experimental results proved that under windless conditions, the heat transfer coefficient and total heat rejection of circulating water for the optimal non-uniform layout pattern can enhance by approximately 40% and 28%, respectively, compared with the uniform layout pattern. It was also discovered that the optimal non-uniform pattern can dramatically relieve the influence of crosswind on the thermal performance of the tower when the crosswind speed is equal to 0.4 m/s. For the uniform layout pattern, the heat transfer coefficient under 0.4 m/s crosswind conditions decreased by 9.5% compared with the windless conditions, while that value lowered only by 2.0% for the optimal non-uniform layout pattern. It has been demonstrated that the optimal non-uniform layout pattern has the better thermal performance under 0.4 m/s crosswind condition.

  19. Heat-Exchanger/Heat-Pipe Interface

    Science.gov (United States)

    Snyder, H. J.; Van Hagan, T. H.

    1987-01-01

    Monolithic assembly reliable and light in weight. Heat exchanger and evaporator ends of heat pipes integrated in monolithic halves welded together. Interface assembly connects heat exchanger of furnace, reactor, or other power source with heat pipes carrying heat to radiator or power-consuming system. One of several concepts proposed for nuclear power supplies aboard spacecraft, interface useful on Earth in solar thermal power systems, heat engines, and lightweight cooling systems.

  20. Heat Stress Control and Heat Casualty Management

    National Research Council Canada - National Science Library

    Sawka, M. N; Wenger, C. B; Montain, S. J; Kolka, M. A; Bettencourt, B; Flinn, S; Gardner, J; Matthew, W. T; Lovell, M; Scott, C

    2003-01-01

    .... Understand the effect of fluid and electrolyte imbalances (para 4-7); h. Understand the methodology, needed equipment, use of, and correction procedures for the wet bulb globe temperature (WBGT) index (appendix P...

  1. Signatures of the appearance of ice 0 in wetted nanoporous media at electromagnetic measurements

    Science.gov (United States)

    Bordonskiy, G. S.; Orlov, A. O.

    2017-04-01

    Ice 0 that is a new modification of crystalline ice, which can be formed only from supercooled water, is sought. To this end, the electric parameters of wetted nanoporous silicates SBA-15 and silica gel (Acros) for obtaining deeply supercooled water in pores are studied. Three electrical parameters of a medium are measured: the reflection coefficient of microwave radiation from the interface between the medium and air in a waveguide at a frequency of 12.4 GHz and the transmittance of radiation at a frequency of 94 GHz, the tangent of the dielectric loss angle at frequencies from 10 Hz to 100 kHz, and the characteristic electrical fluctuations in the frequency band of 1-100 Hz. Studies are performed at cyclic cooling and heating of the samples in the temperature range from + 20 °C to -150 °C. Sharp changes in all three parameters of the wetted silicates are revealed near the temperature range from -20 °C to - 24 °C. These changes can be attributed to the formation or destruction of ferroelectric ice 0.

  2. Can I Stop Myself From Having a Wet Dream? (For Teens)

    Science.gov (United States)

    ... Can I Stop Myself From Having a Wet Dream? KidsHealth > For Teens > Can I Stop Myself From Having a Wet Dream? Print A A A Can I stop myself from having a wet dream? – Tom* You really can't stop wet dreams, ...

  3. Heating systems for heating subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-04-26

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

  4. Hydride heat pump with heat regenerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

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

  5. Modeling of GPS tropospheric delay wet Neill mapping function (NMF)

    Science.gov (United States)

    Sakidin, Hamzah; Ahmad, Asmala; Bugis, Ismadi

    2014-10-01

    The modeling of the GPS tropospheric delay mapping function should be revised by modifying or simplify its mathematical model. Some current mapping functions models are separated into hydrostatic and the wet part. The current tropospheric delay models use mapping functions in the form of continued fractions. This model is quite complex and need to be simplified. By using regression method, the wet mapping function models has been selected to be simplified. There are eleven operations for wet mapping function component of Neill Mapping Function (NMF), to be carried out before getting the mapping function scale factor. So, there is a need to simplify the mapping function models to allow faster calculation and also better understanding of the models.

  6. Drying and wetting of building materials and components

    CERN Document Server

    2014-01-01

    This book, Drying and Wetting of Building Materials and Components, provides a collection of recent contributions in the field of drying and wetting in porous building materials. The main benefit of the book is that it discusses some of the most important topics related to the drying and wetting processes, namely, innovations and trends in drying science and technology, drying mechanism and theory, equipment, advanced modelling, complex simulation and experimentation. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

  7. Development of the Internet Watershed Educational Tool (InterWET

    Directory of Open Access Journals (Sweden)

    Shane Parson

    2000-01-01

    Full Text Available Watershed educational and informational efforts have largely neglected to inform one important group of decision-makers: local government officials. The Internet Watershed Educational Tool (InterWET was developed to help inform local officials about water resources, using as a case study the Spring Creek Watershed in central Pennsylvania. Utilizing the "microworlds" concept, InterWET consists of a set of web pages that present water resource issues and components from different perspectives. Specifically, the components of surface runoff, groundwater flow, detached and delivered sediment, in-stream nutrients, and fish populations are presented from the perspectives of a researcher, a conservationist, and a local official. In addition to informing local officials, InterWET can also be used as a stand-alone informational resource or as part of larger watershed educational efforts.

  8. Some specificities of wetting by cyanobiphenyl liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Delabre, U; Richard, C; Cazabat, A M, E-mail: cazabat@lps.ens.f [Laboratoire de Physique Statistique, Ecole Normale Superieure, Universite Pierre et Marie Curie, CNRS, 24 rue Lhomond, 75231 Paris Cedex 05 (France)

    2009-11-18

    The present paper provides an up to date restatement of the wetting behaviour of the series of cyanobiphenyl liquid crystals (LCs) on usual substrates, i.e. oxidized silicon wafers, water and glycerol, at both the macroscopic and microscopic scale, in the nematic range of temperature. We show that on water the systems are close to a wetting transition, especially 5CB and 7CB. In that case, the wetting behaviour is controlled by the presence of impurities. On a mesoscopic scale, we observe for all our (thin LC film-substrate) systems an identical, complex, but well defined general scenario, not accounted for by the available models. In the last part, we present a study on line tension which results from the specific organization of LCs at the edge of the nematic film. We report preliminary results on two-dimensional film coalescence where this line tension plays a major role.

  9. Liquid Metal Phagocytosis: Intermetallic Wetting Induced Particle Internalization.

    Science.gov (United States)

    Tang, Jianbo; Zhao, Xi; Li, Jing; Zhou, Yuan; Liu, Jing

    2017-05-01

    A biomimetic cellular-eating phenomenon in gallium-based liquid metal to realize particle internalization in full-pH-range solutions is reported. The effect, which is called liquid metal phagocytosis, represents a wet-processing strategy to prepare various metallic liquid metal-particle mixtures through introducing excitations such as an electrical polarization, a dissolving medium, or a sacrificial metal. A nonwetting-to-wetting transition resulting from surface transition and the reactive nature of the intermetallic wetting between the two metallic phases are found to be primarily responsible for such particle-eating behavior. Theoretical study brings forward a physical picture to the problem, together with a generalized interpretation. The model developed here, which uses the macroscopic contact angle between the two metallic phases as a criterion to predict the particle internalization behavior, shows good consistency with experimental results.

  10. Helminths in rodents from Wet Markets in Thailand

    Directory of Open Access Journals (Sweden)

    Ribas A.

    2016-12-01

    Full Text Available Only a few surveys have ever been carried out of the helminths of the commensal rodents found in the traditional wet markets that play such an important part of daily life in South-east Asia. The potential of rodents as reservoirs of zoonoses including helminths is of great interest since in these markets humans and rodents come into closer contact than in other environments and food may be indirectly contaminated via rodent faeces. Helminths in a total of 98 rats belonging to two species (Rattus norvegicus and Rattus exulans were surveyed in eight traditional wet markets in Udon Thani, Thailand. Thirteen species of helminths were recovered, seven of which are potentially zoo-notic, with an overall prevalence of 89.8 %. Our results show that rodents in wet markets could pose a threat to human health as potential reservoirs of zoonotic helminthiases.

  11. Tailoring the microstructure of particle-stabilized wet foams.

    Science.gov (United States)

    Gonzenbach, Urs T; Studart, André R; Tervoort, Elena; Gauckler, Ludwig J

    2007-01-30

    Inorganic colloidal particles which are in situ hydrophobized upon adsorption of short-chain amphiphilic molecules can be used as foam stabilizers. In this study, we tailor the microstructure of particle-stabilized wet foams, namely, the foam air content, average bubble size, and bubble size distribution, by changing the composition of the initial colloidal suspension. Wet foams featuring average bubble sizes between 10 and 200 microm and air contents between 45% and 90% were obtained by adjusting the amphiphile and particle concentration, pH, ionic strength, and particle size in the initial suspension. The influence of these parameters on the bubble size was satisfactorily described in terms of a balance between the shear stress applied during mixing and the counteracting Laplace pressure of the air bubbles. This model, originally developed for oil droplets in emulsions, can therefore be used to deliberately tailor the microstructure of particle-stabilized wet foams.

  12. Psychiatric disturbance, urgency, and bacteriuria in children with day and night wetting.

    Science.gov (United States)

    Berg, I; Fielding, D; Meadow, R

    1977-01-01

    Forty children with day and night wetting were compared with 46 with night wetting only to see if day wetting was then associated with particular clinical features. Interviews with mothers, questionnaries completed by teachers, physical investigations, and measurement of functional bladder capacities were used. Day wetting combined with bed wetting occurred equally in boys and girls and was associated with daytime urgency and greater frequency of psychiatric disturbance. In boys, soiling was also associated. In girls, bacteriuria, which appeared to be caused by the day wetting, occurred in about 50%. Neither daytime frequency nor small functional bladder capacity were specifically related to day wetting. PMID:921313

  13. Evaluation of supercritical water gasification and biomethanation for wet biomass utilization in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Yukihiko [Hiroshima Univ., Dept. of Mechanical System Engineering, Hiroshima (Japan)

    2002-08-01

    Two wet biomass gasification processes, supercritical water gasification and biomethanation, were evaluated from energy, environmental, and economic aspects. Gasification of 1 dry-t/d of water hyacinth was taken as a model case. Assumptions were made that system should be energetically independent, that no environmentally harmful material should be released, and that carbon dioxide should be removed from the product gas. Energy efficiency, carbon dioxide payback time, and price of the product gas were chosen as indices for energy, environmental, and economic evaluations, respectively. Under the conditions assumed here, supercritical water gasifications is evaluated to be more advantageous over biomethanation, but the cost of the product gas is still 1.86 times more expensive than city gas in Tokyo. To improve efficiency of supercritical water gasification, improvement of heat exchanger efficiency is effective. Utilization of fermentation sludge will make biomethanation much more advantageous. (Author)

  14. Black silicon with self-cleaning surface prepared by wetting processes.

    Science.gov (United States)

    Zhang, Ting; Zhang, Peng; Li, Shibin; Li, Wei; Wu, Zhiming; Jiang, Yadong

    2013-08-13

    This paper reports on a simple method to prepare a hydrophobic surface on black silicon, which is fabricated by metal-assisted wet etching. To increase the reaction rate, the reaction device was placed in a heat collection-constant temperature type magnetic stirrer and set at room temperature. It was demonstrated that the micro- and nanoscale spikes on the black silicon made the surface become hydrophobic. As the reaction rate increases, the surface hydrophobicity becomes more outstanding and presents self-cleaning until the very end. The reflectance of the black silicon is drastically suppressed over a broad spectral range due to the unique geometry, which is effective for the enhancement of absorption.

  15. Preparation and properties of ferromagnetic Z-type hexaferrite from wet milled mixtures of intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Temuujin, Jadambaa [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Aoyama, Masami [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Senna, Mamoru [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan)]. E-mail: senna@applc.keio.ac.jp; Masuko, Taisuke [Materials Research and Development Division, General Research and Development Laboratories, Taiyo Yuden Co., Ltd, 5607-2 Nakamuroda, Gunma 370-3347 (Japan); Ando, Chie [Materials Research and Development Division, General Research and Development Laboratories, Taiyo Yuden Co., Ltd, 5607-2 Nakamuroda, Gunma 370-3347 (Japan); Kishi, Hiroshi [Materials Research and Development Division, General Research and Development Laboratories, Taiyo Yuden Co., Ltd, 5607-2 Nakamuroda, Gunma 370-3347 (Japan); Sepelak, Vladimir [Institute of Physical and Theoretical Chemistry, Technical University of Braunschweig, Hans-Sommer-Street 10, D-38106 Braunschweig (Germany); Becker, Klaus Dieter [Institute of Physical and Theoretical Chemistry, Technical University of Braunschweig, Hans-Sommer-Street 10, D-38106 Braunschweig (Germany)

    2007-04-15

    Almost pure Z-type phases of hexaferrites were synthesized by firing preliminarily milled M- and Y-type phases intermediates at 1250 deg. C. These phases were obtained by calcining the stoichiometric powder mixture precursors at 1080 deg. C, followed by wet milling in a planetary mill for 1 h and subsequent heating at 1250 deg. C that increased the fractional crystallization of the Z-phase up to 96%. Addition of 0.2 wt% SiO{sub 2} to the intermediates reduced the milling time necessary for the sintered density required for practical permeability measurement. Z-phase hexaferrite sintered at 1250 deg. C for 2 h exhibited fairly good high-frequency properties, i.e. an initial real permeability of up to 19.3 below 100 MHz and 8-10 at around 1 GHz.

  16. Impacts from Time-dependent Freezing of Rain and Wet Hail on Deep Convection Simulated by a Cloud Model with Spectral Bin Microphysics

    Science.gov (United States)

    Phillips, V. T.; Khain, A.; Ilotoviz, E.; BenMoshe, N.

    2014-12-01

    Any hydrometeor containing some supercooled liquid can only freeze it as fast as latent heat is dissipated to the ambient air. Consequently, at sub-zero temperatures any given particle in a cloud can contain both ice and liquid water. Wet growth of hail occurs when supercooled cloud-liquid is accreted faster than it can freeze immediately on impact. Equally, raindrops in clear air can take up to a few mins to freeze. A new theory of time-dependent freezing is proposed in this presentation. First, wet growth of hail is represented by treating inhomogeneities of liquid coverage and temperature over the surface of the particle. Radial heat fluxes from the sponge layer through the liquid skin to the air are predicted, as well as heat fluxes between its wet and dry parts. Gradual internal freezing of liquid that soaks the interior of the hail or graupel particle during dry growth ('riming') is represented. The microphysical recycling with alternating episodes of wet and dry growth is predicted. Second, the time-dependent process of raindrop freezing is represented by including thermodynamic effects from accretion of cloud-liquid and -ice. Freezing drops larger than about 0.1 mm are represented as a new microphysical species in a cloud model with spectral bin microphysics. The freezing drops consist of interior water covered by ice initially. Possibilities of both dry and wet growth of freezing drops are represented. Schemes of time-dependent freezing for rain and wet growth of hail and graupel were implemented in a spectral bin microphysics cloud model. The model predicted that accretion of liquid produces giant freezing drops of 0.5-2 cm in diameter, due to downdraft-updraft recirculation and wet growth of freezing drops. Appreciable contents of freezing drops reach a height level of 7 km (-30 degC) in the simulated storm. The critical diameter separating wet and dry growth regimes is predicted to increase with height for freezing drops. It is more vertically uniform

  17. Investigation of the effect of packing location on performance of closed wet cooling tower based on exergy analysis

    Science.gov (United States)

    Qasim, S. M.; Hayder, M. J.

    2016-08-01

    In this paper, the effect of packing location on thermal performance of Closed Wet Cooling Tower (CWCT) based on exergy analysis has been studied. The experimental study incorporates design, manufacture and testing of a modified counter flow forced draft CWCT prototype. The modification based on addition packing to the conventional CWCT. The variation of spray water temperature, air dry bulb temperature, air wet bulb temperature, enthalpy and relative humidity of air for different position along the tower are measured experimentally. Applying the exergy destruction method for the cooling tower; exergy destruction, exergy efficiency, exergy of water and air were calculated for two cases: CWCT with packing below the heat exchanger and CWCT with packing above the heat exchanger. It is highly important to analyze the exergy along the cooling tower height. Therefore, the exergy analysis of different elements along the height of the tower is carried out. Results show that the total exergy destruction of modified CWCT is higher when the heat exchanger is located above the packing at the highest point of the tower.

  18. Wetting behavior on hybrid surfaces with hydrophobic and hydrophilic properties

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Chun-Wei [Dept. of Mechanical Engineering, Texas A and M University, College Station, TX 77843 (United States); Alvarado, Jorge L., E-mail: Alvarado@entc.tamu.edu [Dept. of Engineering Technology and Industrial Distribution, Texas A and M University, College Station, TX 77843 (United States); Marsh, Charles P. [ERDC – Construction Engineering Research Laboratory, 2902 Newmark Dr., Champaign, IL 61826 (United States); Dept. of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States); Jones, Barclay G. [Dept. of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States); Collins, Michael K. [ERDC – Construction Engineering Research Laboratory, 2902 Newmark Dr., Champaign, IL 61826 (United States); Dept. of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States)

    2014-01-30

    Hybrid surfaces consisting of a micropillar array of hydrophobic and hydrophilic sites were designed and fabricated to understand the effects of their unique surface morphology and chemistry on droplet condensation. Droplet impingement experiments have revealed that hybrid surfaces exhibit high contact angles, which is characteristic of purely hydrophobic surfaces. However, little is known about the wetting behavior of droplets that nucleate and grow on hybrid surfaces during condensation. In fact, condensed droplets display a distinct wetting behavior during the droplet growth phase which cannot be reproduced by simply impinging droplets on hybrid surfaces. In this study, hybrid surfaces with three different spacing ratios were subjected to condensation tests using an environmental scanning electron microscopy (ESEM) and a condensation cell under ambient conditions. For hybrid surfaces with spacing ratio below 2, droplets were observed to form on top and sides of the micropillars, where they grew, coalesced with adjacent droplets, and shed after reaching a given size. After shedding, the top surface remained partially dry, which allowed for immediate droplet growth. For hybrid surfaces with spacing ratio equal to 2, a different wetting behavior was observed, where droplets basically coalesced and formed a thin liquid film which was ultimately driven into the valleys of the microstructure. The liquid shedding process led to the renucleation of droplets primarily on top of the dry hydrophilic sites. To better understand the nature of droplet wetting on hybrid surfaces, a surface energy-based model was developed to predict the transition between the two observed wetting behaviors at different spacing ratios. The experimental and analytical results indicate that micropillar spacing ratio is the key factor for promoting different wetting behavior of condensed droplets on hybrid surfaces.

  19. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1982-01-01

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

  20. Heat-Related Illnesses

    Medline Plus

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