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Sample records for sunlight exposure heat

  1. Ultra-accelerated natural sunlight exposure testing

    Science.gov (United States)

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  2. Effects of Sunlight Exposure on the Quality Parameters of Bottled ...

    African Journals Online (AJOL)

    PROF HORSFALL

    microbial population (total coliform) of the bottled water with increasing exposure to sunlight was observed. ... safe drinking water which has led to the tremendous ... degradation under high temperature (Bach et al., ..... Solar and photocatalytic.

  3. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    Science.gov (United States)

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  4. Dietary calcium intake and sunlight exposure among children aged ...

    African Journals Online (AJOL)

    Nutritional rickets can be caused by either or both calcium and vitamin D deficiencies, and can frequently occur in Africa. In Ethiopia, limited evidence exists regarding the calcium intake of children and their sunlight exposure practices. The purpose of this study was to assess information regarding dietary calcium intake and ...

  5. Can Skin Exposure to Sunlight Prevent Liver Inflammation?

    Directory of Open Access Journals (Sweden)

    Shelley Gorman

    2015-05-01

    Full Text Available Liver inflammation contributes towards the pathology of non-alcoholic fatty liver disease (NAFLD. Here we discuss how skin exposure to sunlight may suppress liver inflammation and the severity of NAFLD. Following exposure to sunlight-derived ultraviolet radiation (UVR, the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide. Animal modeling studies suggest that exposure to UVR can prevent the development of NAFLD. Association studies also support a negative link between circulating 25-hydroxyvitamin D and NAFLD incidence or severity. Clinical trials are in their infancy and are yet to demonstrate a clear beneficial effect of vitamin D supplementation. There are a number of potentially interdependent mechanisms whereby vitamin D could dampen liver inflammation, by inhibiting hepatocyte apoptosis and liver fibrosis, modulating the gut microbiome and through altered production and transport of bile acids. While there has been a focus on vitamin D, other mediators induced by sun exposure, such as nitric oxide may also play important roles in curtailing liver inflammation.

  6. The effects of sunlight exposure on the neutron response of CN-85 track detector

    International Nuclear Information System (INIS)

    Ahmad, N.; Mirza, N.M.; Mirza, S.K.; Tufail, M.

    1996-01-01

    The effect of sunlight exposure on the neutron response of CN-85 track detectors has been studied. It has been observed that the response during the first 28 days of sunlight exposure is slightly enhanced (10%) and then deceases continuously with increase in the sunlight exposure. After 84 days of sunlight exposure the response of the exposed detector relative to an unexposed detector is only 22%. It is also observed that the response can not be maintained by wrapping the CN-85 etch track detectors in typewriter black carbon papers if they are exposed to sunlight. (author)

  7. Factors influencing adherence with therapeutic sunlight exposure in older people in intermediate care facilities.

    Science.gov (United States)

    Durvasula, Seeta; Sambrook, Philip N; Cameron, Ian D

    2012-01-01

    The purpose of this study was to investigate the factors influencing low adherence with therapeutic sunlight exposure in a randomized controlled trial conducted with older people living in intermediate care facilities. The study involved participants in the FREEDOM (Falls Risk Epidemiology: Effect of vitamin D on skeletal Outcomes and other Measures) study, a randomized controlled trial of therapeutic sun exposure to reduce falls in older people in intermediate care facilities. Semi-structured interviews were conducted with thirty participants in the FREEDOM trial, and with ten sunlight officers who were employed to facilitate the sun exposure. Two focus groups involving 10 participants in the FREEDOM trial were also held at the end of the intervention period. Common themes were derived from the interview and focus group transcripts. The study showed that the perceived health benefits did not influence adherence with the sun exposure. Factors such as socializing with others and being outdoors were more important in encouraging attendance. The main barriers to adherence included the perceived inflexibility and regimentation of daily attendance, clash with other activities, unsuitable timing and heat discomfort. This study showed that providing greater flexibility and autonomy to older people in how and when they receive sun exposure is likely to improve adherence. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. PRKCZ methylation is associated with sunlight exposure in a North American but not a Mediterranean population

    Science.gov (United States)

    Sunlight exposure has been shown to alter DNA methylation patterns across several human cell-types, including T-lymphocytes. Since epigenetic changes establish gene expression profiles, changes in DNA methylation induced by sunlight exposure warrant investigation. The purpose of this study was to as...

  9. Sunlight exposure and sun sensitivity associated with disability progression in multiple sclerosis

    NARCIS (Netherlands)

    D'hooghe, M. B.; Haentjens, P.; Nagels, G.; Garmyn, M.; De Keyser, J.

    Background: Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). Objective: We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. Methods: We conducted a survey among persons with MS, registered by the Flemish MS

  10. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, B.F. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Andreani, T. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CITAB − Centre for Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, UTAD, Vila Real (Portugal); Gavina, A., E-mail: anacsgavina@gmail.com [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Vieira, M.N. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Pereira, C.M. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Rocha-Santos, T. [Department of Chemistry and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); and others

    2016-07-15

    Highlights: • Under sunlight exposure, all QDs form particle aggregates in the different media. • CdSeS/ZnS QDs showed lower toxic effects to V. fischeri before sunlight exposure. • Sunlight exposure decreased the toxicity of CdS 480 in all organisms. • Sunlight exposure increased the toxicity of CdS 380 QDs for D. magna. • Shell of QDs seemed to make them less harmful to aquatic organisms. - Abstract: Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same

  11. Water balance of goats in Jeneponto - South Sulawesi under sunlight exposure and water restriction

    Directory of Open Access Journals (Sweden)

    Djoni Prawira Rahardja

    2007-10-01

    Full Text Available Water balance of 5 does of Kacang goat of Jeneponto was studied under the condition of sunlight exposure and water restriction. The study was conducted in dry season with 4 consecutive treatments of 10 d with 4-5 d of adjustment period between two consecutive treatments: (1 indoor and unrestricted water; (2 indoor and restricted water; (3 10 h outdoor–and unrestricted water; (4 10 h outdoor – restricted water. The maximum air temperature of outdoor was 39.3OC, and it was 30OC in the indoor environment. In all treatments, the animals were placed in the individual crates. The plasma volume of the goats was higher under sunlight exposure, but it decreased by water restriction, while hematocrite value indicated a reverse responses. Sunlight exposure did not significantly decrease the intake and digestion of organic matter, but water restriction affected significantly and this effect was higher under sunlight exposre. The proportions of water loss through every avenue were maintained relatively constant either under water restriction or sunlight exposure in which the respration rate increased significantly. The findings suggest that sunlight exposure with unrestricted water resulted in a positive water balance without a significant change in organic matter intake and utilization. Water restriction resulted in a negative water balance, reducing organic matter intake and utilization. As the adaptive mechanisms, the goat appeared to be able to withstand in the harsh environment of Jeneponto by expanding plasma volume, increasing body temperature and respiration rate.

  12. Hypovitaminosis D in patients undergoing kidney transplant: the importance of sunlight exposure

    Directory of Open Access Journals (Sweden)

    Cristiane F. Vilarta

    Full Text Available OBJECTIVES: Recent studies have shown a high prevalence of hypovitaminosis D, defined as a serum 25-hydroxyvitamin D level less than 30 ng/ml, in both healthy populations and patients with chronic kidney disease. Patients undergoing kidney transplant are at an increased risk of skin cancer and are advised to avoid sunlight exposure. Therefore, these patients might share two major risk factors for hypovitaminosis D: chronic kidney disease and low sunlight exposure. This paper describes the prevalence and clinical characteristics of hypovitaminosis D among patients undergoing kidney transplant. METHODS: We evaluated 25-hydroxyvitamin D serum levels in a representative sample of patients undergoing kidney transplant. We sought to determine the prevalence of hypovitaminosis D, compare these patients with a control group, and identify factors associated with hypovitaminosis D (e.g., sunlight exposure and dietary habits. RESULTS: Hypovitaminosis D was found in 79% of patients undergoing kidney transplant, and the major associated factor was low sunlight exposure. These patients had higher creatinine and intact parathyroid hormone serum levels, with 25-hydroxyvitamin D being inversely correlated with intact parathyroid hormone serum levels. Compared with the control group, patients undergoing kidney transplant presented a higher prevalence of 25-hydroxyvitamin D deficiency and lower serum calcium, phosphate and albumin but higher creatinine and intact parathyroid hormone levels. CONCLUSIONS: Our results confirmed the high prevalence of hypovitaminosis D in patients undergoing kidney transplant. Therapeutic strategies such as moderate sunlight exposure and vitamin D supplementation should be seriously considered for this population.

  13. Greenhouse Effect: Temperature of a Metal Sphere Surrounded by a Glass Shell and Heated by Sunlight

    Science.gov (United States)

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the "z"-axis. This development is a generalization of the simple treatment of the…

  14. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

    NARCIS (Netherlands)

    Schick, T.; Ersoy, L.; Lechanteur, Y.T.; Saksens, N.T.; Hoyng, C.B.; Hollander, A.I. den; Kirchhof, B.; Fauser, S.

    2016-01-01

    PURPOSE: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). METHODS: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information

  15. Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial

    NARCIS (Netherlands)

    Wicherts, I.S.; Boeke, A.J.P.; van der Meer, I.M.; van Schoor, N.M.; Knol, D.L.; Lips, P.T.A.M.

    2011-01-01

    Summary: Vitamin D deficiency is very common in non-western immigrants. In this randomized clinical trial, vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure. Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D

  16. IS THERE A LINK BETWEEN SUNLIGHT EXPOSURE AND 25-HYDROXYVITAMIN D DEFICIENCY IN CHRONIC KIDNEY DISEASE PATIENTS?

    Directory of Open Access Journals (Sweden)

    Angela Yee-Moon Wang

    2012-06-01

    In conclusion, our study confirmed an extremely high prevalence of vitamin D deficiency and an important association between outdoor sunlight exposure and 25(OHD deficiency in Chinese stage 3-5 CKD patients. Further study is needed to determine whether increasing daily outdoor sunlight exposure may represent a cost-free treatment for correcting nutritional 25(OHD deficiency in the CKD population.

  17. Commonly recommended daily intake of vitamin D is not sufficient if sunlight exposure is limited

    DEFF Research Database (Denmark)

    Glerup, H; Mikkelsen, K; Poulsen, L

    2000-01-01

    OBJECTIVES: Sunlight exposure of the skin is known to be the most important source of vitamin D. The aims of this study were: (i) to estimate vitamin D status amongst sunlight-deprived individuals (veiled Arab women, veiled ethnic Danish Moslem women and Danish controls); and (ii) through food...... intake analysis to estimate the oral intake of vitamin D necessary to keep a normal vitamin D status in sunlight-deprived individuals. DESIGN: Cross-sectional study amongst randomly selected Moslem women of Arab origin living in Denmark. Age-matched Danish women were included as controls. To control...... for racial differences, a group of veiled ethnic Danish Moslem women (all Caucasians) was included. SETTING: Primary Health Care Centre, City Vest and Department of Endocrinology and Metabolism C, University Hospital of Aarhus, Aarhus Amtssygehus, Aarhus, Denmark. SUBJECTS: Sixty-nine Arab women (60 veiled...

  18. Sunlight exposure during leisure activities and risk of prostate cancer in Montréal, Canada, 2005-2009.

    Science.gov (United States)

    Yu, Jennifer; Lavoué, Jérôme; Parent, Marie-Élise

    2014-07-28

    Prostate cancer (PCa) is the leading cause of cancer in men in many developed countries, but no modifiable risk factors have been identified. A handful of analytical studies have suggested a possible etiological role for sunlight exposure. We report here on the association between leisure-time sunlight exposure during adulthood and PCa risk in the context of a population-based case-control study. In all, 1,904 PCa cases were ascertained across Montreal French hospitals between 2005 and 2009. Concurrently, 1,962 population controls, frequency matched to cases by age (±5 years), were selected from the electoral list for French-speakers in Greater Montreal. Interviews elicited the frequency of engagement in any leisure activity during adulthood. This was used to derive cumulative sunlight exposure indices: a cumulative number of leisure activities events entailing sunlight exposure and a cumulative duration of sunlight exposure during leisure activities. Unconditional logistic regression was conducted to yield odds ratios (OR) and 95% confidence intervals (CI) for estimating the association between sunlight exposure indices and PCa risk, adjusting for age, ancestry, family history of PCa, PCa screening, education, solar protection, body mass index and physical activity. Compared with men in the upper quartile category for the number of sunlight exposure events, men never exposed during leisure time had an OR of 1.32 (95% CI: 0.82-2.14). ORs were 1.11, 0.91 and 1.00 for the first to the third quartiles of exposure, respectively. Similar results were observed for cumulative duration of exposure to sunlight, and by PCa aggressiveness. These findings provide little evidence of an association between sunlight exposure during leisure-time and PCa risk. Men with no sunlight exposure appeared at somewhat higher risks but none of the estimates achieved statistical significance.

  19. Prevention of hip fractures by exposure to sunlight and pharmacotherapy in patients with Alzheimer's disease.

    Science.gov (United States)

    Iwamoto, Jun; Sato, Yoshihiro; Tanaka, Kiyoshi; Takeda, Tsuyoshi; Matsumoto, Hideo

    2009-01-01

    Hypovitaminosis D and K due to malnutrition or sunlight deprivation, compensatory hyperparathyroidism, increased bone resorption, low bone mineral density (BMD), and an increased risk of falls may contribute to an increased risk of hip fractures in patients with Alzheimer's disease. The purpose of the present study was to clarify the efficacy of interventions against hip fractures in patients with Alzheimer's disease. With respect to randomized controlled trials (RCTs) regarding Alzheimer's disease and hip fractures, the literature was searched with PubMed. Three RCTs were identified, and the relative risk (RR) and 95% confidence interval (CI) were calculated for individual RCTs. Exposure to sunlight with calcium supplementation, menatetrenone (vitamin K2) plus calcium and vitamin D supplementation, and risedronate plus calcium and vitamin D supplementation improved hypovitaminosis D and hyperparathyroidism, contributing to a reduction in bone resorption. Risedronate itself strongly decreased bone resorption. Menatetrenone also decreased the serum level of undercarboxylated osteocalcin. The three interventions increased metacarpal BMD and reduced the incidence of hip fractures. The respective RRs (95% CI) were 0.22 (0.049-0.999), 0.13 (0.031-0.554), and 0.26 (0.100- 0.690). The present study clarified the efficacy of three interventions, including exposure to sunlight, menatetrenone, and risedronate with calcium and/or vitamin D supplementation against hip fractures in patients with Alzheimer's disease.

  20. Greenhouse effect: temperature of a metal sphere surrounded by a glass shell and heated by sunlight

    International Nuclear Information System (INIS)

    Nguyen, Phuc H; Matzner, Richard A

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the z-axis. This development is a generalization of the simple treatment of the greenhouse effect given by Kittel and Kroemer (1980 Thermal Physics (San Francisco: Freeman)) and can serve as a very simple model demonstrating the much more complex Earth greenhouse effect. Solution of the model problem provides an excellent pedagogical tool at the Junior/Senior undergraduate level.

  1. Sunlight exposure and sun sensitivity associated with disability progression in multiple sclerosis.

    Science.gov (United States)

    D'hooghe, M B; Haentjens, P; Nagels, G; Garmyn, M; De Keyser, J

    2012-04-01

    Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. We conducted a survey among persons with MS, registered by the Flemish MS society, Belgium, and stratified data according to relapsing-onset and progressive-onset MS. We used Kaplan-Meier survival and Cox proportional hazard regression analyses with time to Expanded Disability Status Scale (EDSS) 6 as outcome measure. Hazard ratios for the time from onset and from birth were calculated for the potentially predictive variables, adjusting for age at onset, gender and immunomodulatory treatment. 704 (51.3%) of the 1372 respondents had reached EDSS 6. In relapsing-onset MS, respondents reporting equal or higher levels of sun exposure than persons of the same age in the last 10 years had a decreased risk of reaching EDSS 6. In progressive-onset MS, increased sun sensitivity was associated with an increased hazard of reaching EDSS 6. The association of higher sun exposure with a better outcome in relapsing-onset MS may be explained by either a protective effect or reverse causality. Mechanisms underlying sun sensitivity might influence progression in progressive-onset MS.

  2. Quantification of ultraviolet radiation-induced DNA damage in the urine of Swedish adults and children following exposure to sunlight

    OpenAIRE

    Liljendahl, Tove Sandberg; Kotova, Natalia; Segerbäck, Dan

    2012-01-01

    DNA damage following exposure to ultraviolet radiation (UVR) is important in skin cancer development. The predominant photoproduct, cyclobutane thymine dimer (T=T), is repaired and excreted in the urine, where it provides a biomarker of exposure. To quantify urinary T=T levels after recreational sunlight exposure in adults and children. Average UVR doses were measured with personal dosimeters. Urinary T=T was analysed with (32)P-postlabelling. ResuLTS: Background levels of T=T increased...

  3. Sunlight exposure is important for preventing hip fractures in patients with Alzheimer's disease, Parkinson's disease, or stroke.

    Science.gov (United States)

    Iwamoto, J; Takeda, T; Matsumoto, H

    2012-04-01

    Hypovitaminosis D as a result of malnutrition or sunlight deprivation, increased bone resorption, low bone mineral density (BMD), or an increased risk of falls may contribute to an increased risk of hip fractures in patients with neurological diseases, including Alzheimer's disease, Parkinson's disease, and stroke. The purpose of this study was to clarify the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with such neurological diseases. The English literature was searched using PubMed, and randomized controlled trials evaluating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke were identified. The relative risk and the 95% confidence interval were calculated for individual randomized controlled trials, and a pooled data analysis (meta-analysis) was performed. Three randomized controlled trials were identified. Sunlight exposure improved hypovitaminosis D and increased the BMD. The relative risk (95% confidence interval) of hip fractures was 0.22 (0.05, 1.01) for Alzheimer's disease, 0.27 (0.08, 0.96) for Parkinson's disease, and 0.17 (0.02, 1.36) for stroke. The relative risk (95% confidence interval) calculated for the pooled data analysis was 0.23 (0.10, 0.56) (P = 0.0012), suggesting a significant risk reduction rate of 77%. The present meta-analysis added additional evidence indicating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke. © 2011 John Wiley & Sons A/S.

  4. Efficacy of a dose range of simulated sunlight exposures in raising vitamin D status in South Asian adults: implications for targeted guidance on sun exposure.

    Science.gov (United States)

    Farrar, Mark D; Webb, Ann R; Kift, Richard; Durkin, Marie T; Allan, Donald; Herbert, Annie; Berry, Jacqueline L; Rhodes, Lesley E

    2013-06-01

    Vitamin D is essential for bone health, and cutaneous synthesis is an important source. South Asians cannot attain adequate amounts of vitamin D by following general recommendations on summer sunlight exposure at northerly latitudes, and increased exposure may be appropriate for improving their vitamin D status. We examined the efficacy of a dose range of simulated summer sunlight exposures in raising vitamin D status in UK adults of South Asian ethnicity. In a dose-response study, healthy adults of South Asian ethnicity (n = 60; 20-60 y old) received 1 of 6 ultraviolet exposures ranging from 0.65 to 3.9 standard erythema doses (SEDs), which were equivalent to 15-90 min unshaded noontime summer sunlight at 53.5°N (Manchester, United Kingdom), 3 times/wk for 6 wk, while wearing casual clothes that revealed a 35% skin area. Serum 25-hydroxyvitamin D [25(OH)D] was measured weekly, and dietary vitamin D was estimated. At baseline, all completing participants (n = 51) were vitamin D insufficient [25(OH)D concentrations 10 ng/mL. Targeted guidance on sunlight exposure could usefully enhance vitamin D status to avoid deficiency [25(OH)D concentration >10 ng/mL] in South Asians living at latitudes distant from the equator. This trial was registered at the ISRCTN Register (www.isrctn.org) as 07565297.

  5. Effect of exposure to sunlight and phosphorus-limitation on bacterial degradation of coloured dissolved organic matter (CDOM) in freshwater.

    Science.gov (United States)

    Kragh, Theis; Søndergaard, Morten; Tranvik, Lars

    2008-05-01

    This study reports on the interacting effect of photochemical conditioning of dissolved organic matter and inorganic phosphorus on the metabolic activity of bacteria in freshwater. Batch cultures with lake-water bacteria and dissolved organic carbon (DOC) extracted from a humic boreal river were arranged in an experimental matrix of three levels of exposure to simulated sunlight and three levels of phosphorus concentration. We measured an increase in bacterial biomass, a decrease in DOC and bacterial respiration as CO(2) production and O(2) consumption over 450 h. These measurements were used to calculate bacterial growth efficiency (BGE). Bacterial degradation of DOC increased with increasing exposure to simulated sunlight and availability of phosphorus and no detectable growth occurred on DOC that was not pre-exposed to simulated sunlight. The outcome of photochemical degradation of DOC changed with increasing availability of phosphorus, resulting in an increase in BGE from about 5% to 30%. Thus, the availability of phosphorus has major implications for the quantitative transfer of carbon in microbial food webs.

  6. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

    Directory of Open Access Journals (Sweden)

    Iannacone Michelle R

    2012-09-01

    Full Text Available Abstract Background Non-melanoma skin cancer (NMSC, comprised of basal (BCC and squamous (SCC cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. Methods A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous and timing (childhood vs. adulthood of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. Results A history of blistering sunburn (a measure of intermittent sunlight exposure was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03 and SCC (OR = 2.02, 95% CI = 1.22-3.33. Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Conclusions Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous. The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

  7. Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

    International Nuclear Information System (INIS)

    Iannacone, Michelle R; Fenske, Neil A; Rollison, Dana E; Wang, Wei; Stockwell, Heather G; O’Rourke, Kathleen; Giuliano, Anna R; Sondak, Vernon K; Messina, Jane L; Roetzheim, Richard G; Cherpelis, Basil S

    2012-01-01

    Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC

  8. Effect of exposure to sunlight and phosphorus-limitation on bacterial degradation of coloured dissolved organic matter (CDOM) in freshwater

    DEFF Research Database (Denmark)

    Kragh, Theis; Søndergaard, Morten; Tranvik, Lars

    2008-01-01

    This study reports on the interacting effect of photochemical conditioning of dissolved organic matter and inorganic phosphorus on the metabolic activity of bacteria in freshwater. Batch cultures with lake-water bacteria and dissolved organic carbon (DOC) extracted from a humic boreal river were...... arranged in an experimental matrix of three levels of exposure to simulated sunlight and three levels of phosphorus concentration. We measured an increase in bacterial biomass, a decrease in DOC and bacterial respiration as CO(2) production and O(2) consumption over 450 h. These measurements were used...

  9. The influence of exposure to ultraviolet radiation in simulated sunlight on ascospores causing Black Sigatoka disease of banana and plantain

    Science.gov (United States)

    Parnell, Mark; Burt, P. J. A.; Wilson, Kate

    The influence of ultraviolet (UV) radiation in simulated natural sunlight on the viability of ascospores of Mycosphaerella fijiensis, the cause of Black Sigatoka disease in banana and plantain, has been investigated as part of a study to assess the windborne spread of this pathogen from mainland Central and South America into the Caribbean. Spores were killed following continuous exposure to UV radiation for periods of 6 h or over. This relatively short exposure time suggests that the distances over which viable spores can be transported will be determined not only by the speed of the wind but also the amount of cloud cover and the time off day that spore release occurs. On this basis, wind dispersal of viable spores over distances greater than a few hundred kilometres is unlikely. These conclusions are reinforced by an examination of historical reports of the arrival of the disease in previously uninfected areas of the Americas and Africa.

  10. Effect of grape bunch sunlight exposure and UV radiation on phenolics and volatile composition of Vitis vinifera L. cv. Pinot noir wine.

    Science.gov (United States)

    Song, Jianqiang; Smart, Richard; Wang, Hua; Dambergs, Bob; Sparrow, Angela; Qian, Michael C

    2015-04-15

    The effect of canopy leaf removal and ultraviolet (UV) on Pinot noir grape and wine composition was investigated in this study. Limited basal leaf removal in the fruit zone was conducted, compared to shaded bunches. The UV exposure was controlled using polycarbonate screens to block UV radiation, and acrylic screens to pass the UV. The results showed that bunch sunlight and UV exposure significantly increased the Brix and pH in the grape juice, and increased substantially wine colour density, anthocyanins, total pigment, total phenolics and tannin content. Bunch sunlight and UV exposure affected terpene alcohols, C13-norisprenoids and other volatile composition of the wine differently. Sunlight exposure and UV resulted in increase of nerol, geraniol and citronellol but not linalool. Sunlight exposure slightly increased the concentration of β-ionone, but the increase was not statistically significant for UV treatment. Neither sunlight nor UV treatment showed any impact on the concentration of β-damascenone. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Estimation of exposure to sunlight of the liner under a tiled roof

    DEFF Research Database (Denmark)

    Holck, Ole; Rosenfeld, J.L.J.

    2005-01-01

    One construction for a pitched roof is to use tiles on battens, with a liner attached below the battens. The shape of some types of tiles is such that, at each corner where four tiles overlap, a small gap is formed. At certain positions of the sun solar radiation can penetrate through these gaps....... Simulations were carried out for a roof tilted at 25degrees, 35degrees or 45degrees, facing SE, S, SW or W. For the particular roof construction and gap studied, the maximum annual exposure of a 25 mm(2) piece of the liner placed 150 mm below the gap (corresponding to about 100 mm below the base of the tiles...... to the roof. Analytic expressions for the size of the illuminated area are obtained using a thick slit model. The accuracy of the model was assessed by some experimental measurements. The exposure over one year of the roof liner was calculated using the Design Reference Year for Copenhagen, Denmark...

  12. Screening of Metarhizium and Beauveria spp. conidia with exposure to simulated sunlight and a range of temperatures

    International Nuclear Information System (INIS)

    Morley-Davies, J.; Moore, D.; Prior, C.

    1996-01-01

    Conidia of 14 isolates of the entomopathogenic fungi Beauveria bassiana, Metarhizium flavoviride and M. anisopliae were formulated by suspending in paraffinic oil or as dry powder. Non-indicating silica gel was added to both formulations which were stored at 13 °C for at least 2 wk before exposure to a range of temperatures: −10°, 10°, 20°, 30°, 40° and 50° to determine the effects of temperature of storage on viability. At 50° the isolate studied in most detail (M. flavoviride, IMI 330189) initially showed a gradual decline in viability with 73% germination for oil samples after 60 d from an initial level of 93%, whereas the dry samples typically showed higher germination rates (initially 96% germination, dropping to 80% after 60 d). Subsequently there was a rapid decline and both oil formulated and dry conidia had lost almost all viability by 90 d. Samples of IMI 330189 stored dry or in oil, at 40° and below showed > 79% germination after 90 d. M. flavoviride 191–660 exhibited the highest temperature tolerance with >40% germination of the dry stored conidia after 90 d at 50°. Some isolates of both B. bassiana and Metarhizium spp. showed markedly lower tolerance of high temperatures. Samples stored dry usually showed greater percentage germination than samples in oil for all isolates, at all temperatures. The isolates were also exposed to 4, 8, 16 and 24 h uv light from a sunlight simulator at 40°. Conidial viability decreased markedly in all isolates with increasing uv exposure. Germination ranged between 10 and 50% after 24 h exposure to uv, 191–660 retaining highest viability. (author)

  13. Effect of soiling and sunlight exposure on the performance ratio of photovoltaic technologies in Santiago, Chile

    International Nuclear Information System (INIS)

    Urrejola, Elias; Antonanzas, Javier; Ayala, Paulo; Salgado, Marcelo; Ramírez-Sagner, Gonzalo; Cortés, Cristian; Pino, Alan; Escobar, Rodrigo

    2016-01-01

    Highlights: • Performance ratio of PV panels decays daily between 0.13% and 0.56% under soiling. • PV panel degradation is 1.29% for poly, 1.74% for mono and 2.77% for thin film. • An annual weather-corrected performance ratio of 75% is calculated. • A critical cleaning period of 45 days is proposed, no matter cleaning and energy prices. - Abstract: The performance, yearly degradation, and annual yield of photovoltaic systems have been studied in outdoor exposure for two years period 2014–2015 in Santiago, capital of Chile. Photovoltaic panels performance degrades daily in a rate between −0.13% and −0.56% under soiling in highly polluted Santiago, Chile. Yearly degradation of the arrays system was found to be in the order of 1.29% for the polycrystalline array, 1.74% for the monocrystalline array, and 2.77% for the thin film system array. The annual production yield reached 1419–1373 kW h/kWp for Poly, 1459–1444 kW h/kWp for Mono, and 1248–1236 kW h/kWp for TF, in 2014 and 2015, respectively. The annual in-plane irradiation measured reached 1981.3 kW h/m"2 and 1943.2 kW h/m"2, for 2014 and 2015, respectively. A weather-corrected performance ratio is presented showing a yearly performance ratio of around 75% for all technologies. Monthly cleaning and random rain fall have shown positive effects as primarily solutions. Furthermore, we studied the optimal strategies of cleaning for different energy prices and we defined a critical cleaning period of 45 days for a real case, independent on cleaning cost and energy prices. This work contains novel results for the Chilean capital city and can be applied to future installations in the area and serve as further insights for the development of solar energy in Chile.

  14. 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

  15. An integrated effect of protein intake at breakfast and morning exposure to sunlight on the circadian typology in Japanese infants aged 2-6 years.

    Science.gov (United States)

    Nakade, Miyo; Takeuchi, Hitomi; Taniwaki, Nozomi; Noji, Teruki; Harada, Tetsuo

    2009-09-01

    Tryptophan (Trp) intake at breakfast promotes morning-typed circadian typology and higher sleep quality in Japanese children aged 0-6 yrs (Harada et al., 2007). This effect may be accelerated by morning exposure to sunlight, which has not yet been tested. This study aimed to investigate such an effect in Japanese children. In May, 2006, an integrated questionnaire was administered to 0-6-year-old children attending one of 12 kindergartens. 906 parents answered the questionnaire for their children and themselves (response rate: 67.4%). The integrated questionnaire included the revised version for children of the Morningness-Eveningness (M-E) Questionnaire and questions on sleep, nutritional balance, mental health, and sunlight exposure. Analysis was made on data from 744 children aged 2-6 (385 girls, 359 boys) whose average M-E score was 20.6+/-3.46. Children who had breakfast at regular times tended to be more morning-typed and were less frequently angry (p=0.001) and depressed (p=0.007). Children who had nutritionally well-balanced breakfasts tended to be more morning-typed (pbreakfast might be a strong zeitgeber for circadian oscillators of children, and the morning-type driving effect of protein intake could be accelerated by morning exposure to sunlight.

  16. Effects of P25 TiO2 Nanoparticles on the Free Radical-Scavenging Ability of Antioxidants upon Their Exposure to Simulated Sunlight.

    Science.gov (United States)

    Li, Meng; Chong, Yu; Fu, Peter P; Xia, Qingsu; Croley, Timothy R; Lo, Y Martin; Yin, Jun-Jie

    2017-11-15

    Although nanosized ingredients, including TiO 2 nanoparticles (NPs), can be found in a wide range of consumer products, little is known about the effects these particles have on other active compounds in product matrices. These NPs can interact with reactive oxygen species (ROS), potentially disrupting or canceling the benefits expected from antioxidants. We used electron spin resonance spectrometry to assess changes in the antioxidant capacities of six dietary antioxidants (ascorbic acid, α-tocopherol, glutathione, cysteine, epicatechin, and epicatechin gallate) during exposure to P25 TiO 2 and/or simulated sunlight. Specifically, we determined the ability of these antioxidants to scavenge 1-diphenyl-2-picryl-hydrazyl radical, superoxide radical, and hydroxyl radical. Exposure to simulated sunlight alone did not lead to noticeable changes in radical-scavenging abilities; however, in combination with P25 TiO 2 NPs, the scavenging abilities of most antioxidants were weakened. We found glutathione to be the most resistant to treatment with sunlight and NPs among these six antioxidants.

  17. Investigation of sunlight-induced deterioration of aroma of pummelo (Citrus maxima) essential oil.

    Science.gov (United States)

    Sun, Hao; Ni, Hui; Yang, Yuanfan; Wu, Ling; Cai, Hui-nong; Xiao, An-feng; Chen, Feng

    2014-12-10

    Deterioration of aromas of pummelo essential oil (EO) induced by sunlight was compared to those induced by heat and oxygen exposure using the techniques of sensory evaluation and GC-MS analysis. The sunlight-exposed EO was found to possess an oily off-flavor odor, which was significantly different from its counterparts induced by oxygen and heat. The strong oily note of the sunlight-exposed EO was attributed to the existence of linalool oxides and limonene oxides, as well as the lack of neral and geranial, for which UV sunlight was revealed to be the critical contributor causing the chemical reactions for the aroma changes. The results demonstrated that UV sunlight could significantly affect the aroma of the pummelo EO, providing valuable information that will benefit the production and storage of EO-based aromatic products.

  18. Psoriasis, Psoralen and Sunlight

    Directory of Open Access Journals (Sweden)

    R.P.C Naik

    1979-01-01

    Full Text Available Topical or oral administration of photoactive furocumarins followed by exposure to ultra violet light from artificial sources has been shown previously to clear psoriatic lesions. Sunlight has been chosen as the source of UVL m two separate paired comparison studies using topical and, oral 4,5, 8 trimethylpsoralen. Two out of 21 on topical therapy and none out of 6 patients on oral paired-comparison study showed faster clearance of the drug treated lesions compared to control sites.

  19. Firewood boiler operators and heat exposure

    Directory of Open Access Journals (Sweden)

    Vilson Bernardo Stollmeier

    2017-12-01

    Full Text Available This article presents an analysis of heat exposure work in boiler industry wood from a company in the industrial sector, focusing on the analysis of the environmental burden of the activity. Therefore, the methodological procedures consisted of document analysis, interviews, filming, evaluation problems of the effects of the hot environment and its prevention. The results show that the fuel to the boiler operators are exposed to heat and need guidance on their daily activities with prevention of diseases affected by excessive heat. Are also suggested training in technical and health to improve working conditions and the operator's health.

  20. Carotenoids content and sunlight susceptibility

    International Nuclear Information System (INIS)

    Oppezzo, Oscar J.; Costa, Cristina; Pizarro, Ramon A.

    2005-01-01

    Full text: An environmental pink pigmented bacterium was isolated and identified as Rhodococcus sp. Pigmentation mutants were obtained by chemical mutagenesis. Pigments present in the wild type strain (RMB90), in a pale yellow mutant (RMB91) and in two mutants exhibiting increased pigmentation (RMB92 and RMB93), were extracted with chloroform-methanol and analyzed by reverse phase HPLC. Survival of these strains after exposure to sunlight and ultraviolet radiation from artificial sources was studied under different physiological and irradiation conditions. The ability of RMB91 to survive sunlight exposure was reduced with respect to that of RMB90. Resistance was similar in both strains when bacteria grew in the presence of a carotenoid synthesis inhibitor, which had no effect on survival of RMB91. Reduced sunlight resistance in RMB91 was also observed during irradiations under N2. Using artificial radiation sources, non pigmented bacteria were less resistant to UVA, but not to UVB or UVC. Lethal effects of sunlight and UVA on RMB92 and RMB93 were increased with respect to the wild type strain. Carotenoids protect Rhodococcus sp against deleterious effects of sunlight. In non-photosynthetic bacteria studied to date, photo protection by carotenoids was dependent on [O 2 ]. This is not the case with Rhodococcus sp RMB90, suggesting the occurrence of a different mechanism for protection. UVA radiation seems to playa key role in photo-damage. (author)

  1. Sunlight exposure behaviour and vitamin D status in photosensitive patients: longitudinal comparative study with healthy individuals at U.K. latitude.

    Science.gov (United States)

    Rhodes, L E; Webb, A R; Berry, J L; Felton, S J; Marjanovic, E J; Wilkinson, J D; Vail, A; Kift, R

    2014-12-01

    Low vitamin D status is prevalent in wintertime in populations at northerly latitudes. Photosensitive patients are advised to practise sun avoidance, but their sunlight exposure levels, photoprotective measures and resulting vitamin D status are unknown. To examine seasonal vitamin D status in photosensitive patients relative to healthy individuals and to assess quantitatively behavioural and demographic contributors. This was a longitudinal prospective cohort study (53·5°N) examining year-round 25-hydroxyvitamin D [25(OH)D] levels, sun-exposure behaviour and oral vitamin D intake in photosensitive patients diagnosed at a photoinvestigation unit (n = 53), compared with concurrently assessed healthy adults (n = 109). Photosensitive patients achieved seasonal 25(OH)D variation, but insufficient (vitamin D intake was low in both groups (photosensitive: 2·94 μg per day). Supplementation and summer surface area exposure predicted summer peak and winter trough 25(OH)D levels. A 1 μg per day increment in supplementary vitamin D raised summer and winter 25(OH)D by 5% (95% CI 3-7) and 9% (95% CI 5-12), respectively (both P vitamin D status. Guidance on oral measures should target this patient group and their physicians. © 2014 British Association of Dermatologists.

  2. Role of Mediterranean diet, tropical vegetables rich in antioxidants, and sunlight exposure in blindness, cataract and glaucoma among African type 2 diabetics

    Science.gov (United States)

    Moïse, Mvitu Muaka; Benjamin, Longo-Mbenza; Doris, Tulomba Mona; Dalida, Kibokela Ndembe; Augustin, Nge Okwe

    2012-01-01

    AIM To assess whether regular Mediterranean diet and regular intake of vegetables may reduce the risk of blindness, cataract, and glaucoma in these type 2 diabetics. METHODS A cross-sectional design was carried out among known black diabetics admitted at the diabetic clinics of Kinshasa, between October 2008 and March 2009. The Mediterranean-style dietary score (MSDPS) was used to characterize a Mediterranean-style dietary pattern in the study population using the Harvard semi quantitative FFQ adapted for Africa. RESULTS Five hundred Type 2 diabetic patients were included in this study (48% of males; 40% aged ≥60 years). There was a significant association between blindness, cataract and aging; between blindness (P<0.05), cataract (P<0.05), glaucoma (P<0.05), and physical inactivity; between blindness (P<0.05), cataract (P<0.0001), glaucoma (P<0.01) and high SES, and a very significant association between blindness (P<0.0001), cataract (P<0.0001), glaucoma (P<0.0001) and exposure to sunlight. There was also a significant association between blindness, glaucoma, and male sex. Regular intake of Mediterranean diet, Brassica Rapa, beans, Abelmoschus, Musa acuminata reduced significantly the risk of blindness, cataract and glaucoma. CONCLUSION Regular intake of Mediterranean diet, Brassica Rapa, beans, Abelmoschus, and Musa acuminata may significantly reduce the risk of blindness or its major causes among type 2 diabetes mellitus in Africa. PMID:22762057

  3. Health impacts of workplace heat exposure: an epidemiological review.

    Science.gov (United States)

    Xiang, Jianjun; Bi, Peng; Pisaniello, Dino; Hansen, Alana

    2014-01-01

    With predicted increasing frequency and intensity of extremely hot weather due to changing climate, workplace heat exposure is presenting an increasing challenge to occupational health and safety. This article aims to review the characteristics of workplace heat exposure in selected relatively high risk occupations, to summarize findings from published studies, and ultimately to provide suggestions for workplace heat exposure reduction, adaptations, and further research directions. All published epidemiological studies in the field of health impacts of workplace heat exposure for the period of January 1997 to April 2012 were reviewed. Finally, 55 original articles were identified. Manual workers who are exposed to extreme heat or work in hot environments may be at risk of heat stress, especially those in low-middle income countries in tropical regions. At risk workers include farmers, construction workers, fire-fighters, miners, soldiers, and manufacturing workers working around process-generated heat. The potential impacts of workplace heat exposure are to some extent underestimated due to the underreporting of heat illnesses. More studies are needed to quantify the extent to which high-risk manual workers are physiologically and psychologically affected by or behaviourally adapt to workplace heat exposure exacerbated by climate change.

  4. 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

  5. Sunlight and Vitamin D

    Science.gov (United States)

    Wacker, Matthias; Holick, Michael F.

    2013-01-01

    Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences. PMID:24494042

  6. Climate change and health: Indoor heat exposure in vulnerable populations

    International Nuclear Information System (INIS)

    White-Newsome, Jalonne L.; Sánchez, Brisa N.; Jolliet, Olivier; Zhang, Zhenzhen; Parker, Edith A.; Timothy Dvonch, J.; O'Neill, Marie S.

    2012-01-01

    Introduction: Climate change is increasing the frequency of heat waves and hot weather in many urban environments. Older people are more vulnerable to heat exposure but spend most of their time indoors. Few published studies have addressed indoor heat exposure in residences occupied by an elderly population. The purpose of this study is to explore the relationship between outdoor and indoor temperatures in homes occupied by the elderly and determine other predictors of indoor temperature. Materials and methods: We collected hourly indoor temperature measurements of 30 different homes; outdoor temperature, dewpoint temperature, and solar radiation data during summer 2009 in Detroit, MI. We used mixed linear regression to model indoor temperatures' responsiveness to weather, housing and environmental characteristics, and evaluated our ability to predict indoor heat exposures based on outdoor conditions. Results: Average maximum indoor temperature for all locations was 34.85 °C, 13.8 °C higher than average maximum outdoor temperature. Indoor temperatures of single family homes constructed of vinyl paneling or wood siding were more sensitive than brick homes to outdoor temperature changes and internal heat gains. Outdoor temperature, solar radiation, and dewpoint temperature predicted 38% of the variability of indoor temperatures. Conclusions: Indoor exposures to heat in Detroit exceed the comfort range among elderly occupants, and can be predicted using outdoor temperatures, characteristics of the housing stock and surroundings to improve heat exposure assessment for epidemiological investigations. Weatherizing homes and modifying home surroundings could mitigate indoor heat exposure among the elderly.

  7. Hydration and transparency of the rabbit cornea irradiated with UVB-doses of 0.25 J/cm(2) and 0.5 J/cm(2) compared with equivalent UVB radiation exposure reaching the human cornea from sunlight.

    Science.gov (United States)

    Cejka, Cestmír; Ardan, Taras; Sirc, Jakub; Michálek, Jiří; Beneš, Jiří; Brůnová, Blanka; Rosina, Jozef

    2011-07-01

    Exposure of the cornea to UV radiation from sunlight evokes intraocular inflammation, photokeratitis. Photokeratitis is caused by UVB radiation. It is accompanied by changes of corneal hydration and light absorption. The aim of this study was to examine the effect of two UVB doses on corneal optics in rabbits and to compare these UVB doses with the equivalent exposure of UVB radiation reaching the human cornea from sunlight. Rabbit corneas were irradiated with a daily UVB dose of 0.25 J/cm(2) or 0.5 J/cm(2) for 4 days. One day after finishing the irradiations the rabbits were sacrificed and corneal light absorption measured using our spectrophotometrical method. Corneal hydration was examined using an ultrasonic Pachymeter every experimental day before the irradiation procedure and the last day before sacrificing the animals. Changes in corneal optics appeared after the repeated exposure of the cornea to a UVB dose of 0.25 J/ cm(2) and massively increased after the repeated exposure of the cornea to a UVB dose of 0.5 J/cm(2). The first significant changes in corneal hydration appeared after a single exposure of the cornea to a UVB dose of 0.25 J/cm(2). Changes in corneal hydration appeared after the exposure of the rabbit cornea to a single UVB dose equivalent to 2.6 hours of solar UVB radiation reaching the human cornea, as measured by UVB sensors embedded in the eyes of mannequin heads facing the sun on a beach at noon in July. Repeated exposure of the rabbit cornea to the same UVB dose evoked profound changes in corneal optics. Although comparison of experimental and outdoor conditions are only approximate, the results in rabbits point to the danger for the human eye from UVB radiation when short stays in sunlight are repeated for several consecutive days without UV protection.

  8. Heat exposure and socio-economic vulnerability as synergistic factors in heat-wave-related mortality

    International Nuclear Information System (INIS)

    Rey, Gregoire; Fouillet, Anne; Bessemoulin, Pierre; Frayssinet, Philippe; Dufour, Anne; Jougla, Eric; Hemon, Denis

    2009-01-01

    Heat waves may become a serious threat to the health and safety of people who currently live in temperate climates. It was therefore of interest to investigate whether more deprived populations are more vulnerable to heat waves. In order to address the question on a fine geographical scale, the spatial heterogeneity of the excess mortality in France associated with the European heat wave of August 2003 was analysed. A deprivation index and a heat exposure index were used jointly to describe the heterogeneity on the Canton scale (3,706 spatial units). During the heat wave period, the heat exposure index explained 68% of the extra-Poisson spatial variability of the heat wave mortality ratios. The heat exposure index was greater in the most urbanized areas. For the three upper quintiles of heat exposure in the densely populated Paris area, excess mortality rates were twofold higher in the most deprived Cantons (about 20 excess deaths/100,000 people/day) than in the least deprived Cantons (about 10 excess deaths/100,000 people/day). No such interaction was observed for the rest of France, which was less exposed to heat and less heterogeneous in terms of deprivation. Although a marked increase in mortality was associated with heat wave exposure for all degrees of deprivation, deprivation appears to be a vulnerability factor with respect to heat-wave-associated mortality.

  9. Air Ambient-Operated pNIPAM-Based Flexible Actuators Stimulated by Human Body Temperature and Sunlight.

    Science.gov (United States)

    Yamamoto, Yuki; Kanao, Kenichiro; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

    2015-05-27

    Harnessing a natural power source such as the human body temperature or sunlight should realize ultimate low-power devices. In particular, macroscale and flexible actuators that do not require an artificial power source have tremendous potential. Here we propose and demonstrate electrically powerless polymer-based actuators operated at ambient conditions using a packaging technique in which the stimulating power source is produced by heat from the human body or sunlight. The actuating angle, force, and reliability are discussed as functions of temperature and exposure to sunlight. Furthermore, a wearable device platform and a smart curtain actuated by the temperature of human skin and sunlight, respectively, are demonstrated as the first proof-of-concepts. These nature-powered actuators should realize a new class of ultimate low-power devices.

  10. Photochemical effects of sunlight.

    Science.gov (United States)

    Daniels, F

    1972-07-01

    The importance of sunlight in bringing about not only photosynthesis in plants, but also other photochemical effects, is reviewed. More effort should be devoted to photochemical storage of the sun's energy without the living plant. There is no theoretical reason to believe that such reactions are impossible. Ground rules for searching for suitable solar photochemical reactions are given, and a few attempts are described, but nothing successful has yet been found. Future possibilities are suggested. Photogalvanic cells which convert sunlight into electricity deserve further research. Eugene Rabinowitch has been an active pioneer in these fields.

  11. ADEQUATE UV EXPOSURES FOR HEALTHY LIFE: IN SITU MONITORING AND MODEL CALCULATION OF THE VITAMIN-D-SYNTHETIC CAPACITY OF SUNLIGHT

    Directory of Open Access Journals (Sweden)

    Irina Terenetskaya

    2012-06-01

    Full Text Available Vitamin D which is formed upon UV solar radiation in human skin is essential in many physiological functions. To estimate beneficial vitamin-D-synthetic capacity of sunlight a bio-equivalent UV dosimeter that is based on the same molecular photochemistry from which vitamin D is photosynthesized in human skin has been developed. The examples of an in situ monitoring of the vitamin-D-synthetic capacity of sunlight using an in vitro model of vitamin D synthesis are presented, and various operational principles of the UV biodosimeter are discussed. In addition, reliable algorithm is presented for direct calculation of previtamin D3 accumulation using the photoreaction mathematical model with solar UV spectra as input data. Critical dependence of previtamin D3 accumulation on cloudiness and aerosols is demonstrated.

  12. Modeling Exposure to Heat Stress with a Simple Urban Model

    Directory of Open Access Journals (Sweden)

    Peter Hoffmann

    2018-01-01

    Full Text Available As a first step in modeling health-related urban well-being (UrbWellth, a mathematical model is constructed that dynamically simulates heat stress exposure of commuters in an idealized city. This is done by coupling the Simple Urban Radiation Model (SURM, which computes the mean radiant temperature ( T m r t , with a newly developed multi-class multi-mode traffic model. Simulation results with parameters chosen for the city of Hamburg for a hot summer day show that commuters are potentially most exposed to heat stress in the early afternoon when T m r t has its maximum. Varying the morphology with respect to street width and building height shows that a more compact city configuration reduces T m r t and therefore the exposure to heat stress. The impact resulting from changes in the city structure on traffic is simulated to determine the time spent outside during the commute. While the time in traffic jams increases for compact cities, the total commuting time decreases due to shorter distances between home and work place. Concerning adaptation measures, it is shown that increases in the albedo of the urban surfaces lead to an increase in daytime heat stress. Dramatic increases in heat stress exposure are found when both, wall and street albedo, are increased.

  13. Ability to Discriminate Between Sustainable and Unsustainable Heat Stress Exposures-Part 1: WBGT Exposure Limits.

    Science.gov (United States)

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

    2017-07-01

    Heat stress exposure limits based on wet-bulb globe temperature (WBGT) were designed to limit exposures to those that could be sustained for an 8-h day using limited data from Lind in the 1960s. In general, Sustainable exposures are heat stress levels at which thermal equilibrium can be achieved, and Unsustainable exposures occur when there is a steady increase in core temperature. This paper addresses the ability of the ACGIH® Threshold Limit Value (TLV®) to differentiate between Sustainable and Unsustainable heat exposures, to propose alternative occupational exposure limits, and ask whether an adjustment for body surface area improves the exposure decision. Two progressive heat stress studies provided data on 176 trials with 352 pairs of Sustainable and Unsustainable exposures over a range of relative humidities and metabolic rates using 29 participants wearing woven cotton clothing. To assess the discrimination ability of the TLV, the exposure metric was the difference between the observed WBGT and the TLV adjusted for metabolic rate. Conditional logistic regression models and receiver operating characteristic curves (ROC) along with ROC's area under the curve (AUC) were used. Four alternative models for an occupational exposure limit were also developed and compared to the TLV. For the TLV, the odds ratio (OR) for Unsustainable was 2.5 per 1°C-WBGT [confidence interval (CI) 2.12-2.88]. The AUC for the TLV was 0.85 (CI 0.81-0.89). For the alternative models, the ORs were also about 2.5/°C-WBGT, with AUCs between 0.84 and 0.88, which were significantly different from the TLV's AUC but have little practical difference. This study (1) confirmed that the TLV is appropriate for heat stress screening; (2) demonstrated the TLV's discrimination accuracy with an ROC AUC of 0.85; and (3) established the OR of 2.5/°C-WBGT for unsustainable exposures. The TLV has high sensitivity, but its specificity is very low, which is protective. There were no important

  14. Supplementing dairy steers and organically managed dairy cows with synthetic vitamin D3 is unnecessary at pasture during exposure to summer sunlight

    DEFF Research Database (Denmark)

    Hymøller, Lone; Jensen, Søren Krogh; Lindqvist, Hanna

    2009-01-01

    Use of synthetic feed additives, including synthetic vitamin D3 (D3) in the feed for cows and other ruminants, is not consistent with the international principles of organic farming. If dairy farmers wish to produce in accordance with the organic principles, production animals would be left...... with only their endogenous production of D3 from summer sunlight as a source of D3. To examine the impact of supplemental synthetic D3 from the feed on the D3 status of dairy cattle in organic production in Nordic countries, 20 high-yielding dairy cows and 30 dairy steers were divided into two groups: one...... supplemented with synthetic D3 in the feed and one not supplemented with synthetic D3. Vitamin D3 status of the animals was assessed by measuring the concentration of the liver-derived 25-hydroxyvitamin D3 (25OHD3) in plasma. Results showed that 25OHD3 concentration in plasma from dairy cattle as well as from...

  15. Passive Heat Exposure Alters Perception and Executive Function

    Directory of Open Access Journals (Sweden)

    Rachel A. Malcolm

    2018-05-01

    Full Text Available Findings regarding the influence of passive heat exposure on cognitive function remain equivocal due to a number of methodological issues including variation in the domains of cognition examined. In a randomized crossover design, forty-one male participants completed a battery of cognitive function tests [Visual Search, Stroop, Corsi Blocks and Rapid Visual Information Processing (RVIP tests] prior to and following 1 h of passive rest in either hot (39.6 ± 0.4°C, 50.8 ± 2.3% Rh or moderate (21.2 ± 1.8°C, 41.9 ± 11.4% Rh conditions. Subjective feelings of heat exposure, arousal and feeling were assessed alongside physiological measures including core temperature, skin temperature and heart rate, at baseline and throughout the protocol. Response times were slower in the hot trial on the simple (main effect of trial, P < 0.001 and complex (main effect of trial, P < 0.001 levels of the Stroop test (Hot: 872 ± 198 ms; Moderate: 834 ± 177 ms and the simple level of the visual search test (Hot: 354 ± 54 ms; Moderate: 331 ± 47 ms (main effect of trial, P < 0.001. Participants demonstrated superior accuracy on the simple level of the Visual Search test in the hot trial (Hot: 98.5 ± 3.1%; Moderate: 97.4 ± 3.6% (main effect of trial, P = 0.035. Participants also demonstrated an improvement in accuracy on the complex level of the visual search test following 1 h passive heat exposure (Pre: 96.8 ± 5.9%; Post: 98.1 ± 3.1%, whilst a decrement was seen across the trial in the moderate condition (Pre: 97.7 ± 3.5; Post: 97.0 ± 5.1% (time*trial interaction, P = 0.029. No differences in performance were observed on the RVIP or Corsi Blocks tests (all P > 0.05. Subjective feelings of thermal sensation and felt arousal were higher, feeling was lower in the hot trial, whilst skin temperature, core temperature and heart rate were higher (main effects of trial, all P < 0.001. The findings of the present study suggest that response times for perception

  16. Reversible degradation of inverted organic solar cells by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manor, Assaf; Katz, Eugene A

    2011-01-01

    . The transient state is believed to be a result of the breakdown of the diode behaviour of the ZnO electron transport layer by O2 desorption, increasing the hole conductivity. These results imply that accelerated degradation of organic solar cells by concentrated sunlight is not a straightforward process......Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5–15 suns at three different stages: for a pristine...

  17. Photocatalytic activity of V doped ZnO nanoparticles thin films for the removal of 2- chlorophenol from the aquatic environment under natural sunlight exposure.

    Science.gov (United States)

    Salah, Numan; Hameed, A; Aslam, M; Babkair, Saeed S; Bahabri, F S

    2016-07-15

    Vanadium doped ZnO powders were used as precursors to deposit thin films of V(5+) incorporated ZnO nanoparticles on glass substrates by the pulsed laser deposition technique. The observed variations in Raman signals, visible region shift in the diffuse reflectance spectra along with a small shift in the (101) reflections of the X-ray diffraction (XRD) confirmed the insertion of V(5+) ions in ZnO lattice. No other additional reflection in the XRD results other than ZnO further endorsed the occupation of lattice positions by V entities rather than independent oxide formation. The asymmetric XPS peaks of Zn2p and V2p core levels confirmed the existence of both in the vicinity. The existence of minimal proportion of V(3+) along with V(5+) states varied the alteration of the oxidation states V in the synthetic route. The SEM images at various resolutions displayed the uniform distribution identical nanoparticles without the presence of additional phases in the deposited films. The SEM cross-section measurements revealed the uniform thickness of ∼90 nm of each film, whereas the surface studies of the films were performed by AFM. The as-synthesized films were tested for photocatalytic activity in sunlight illumination for the removal of 2-chlorophenol. The unique feature of the study was the estimation of the photocatalytic activity 20 ppm of 2-chlorophenol by exposing the low exposed area. The degradation of the substrate was measured by liquid phase UV-vis spectroscopy, whereas total organic carbon measurement revealed the mineralization of the substrate. The released Cl(-) ions were also measured by ion chromatography. The estimated flatband potentials and pHzpc values of the V doped materials, by Mott-Schottky analysis and zeta potential measurements respectively, were correlated with the photocatalytic activity. The kinetics of the photocatalytic degradation/mineralization process was estimated and results were correlated with the plausible mechanism. Copyright

  18. Holick's rule and vitamin D from sunlight.

    Science.gov (United States)

    Dowdy, John C; Sayre, Robert M; Holick, Michael F

    2010-07-01

    Holick's rule says that sun exposure 1/4 of a minimal erythemal dose (MED) over 1/4 of a body is equivalent to 1000 International Units (IU) oral vitamin D3. Webb and Engelsen recently commented that the ultraviolet (UV) spectrum used to establish Holick's rule is unknown. They consequently used a spring midday Boston solar spectrum to estimate ample sunlight exposures for previtamin D3 (preD3) at various locations. Literature review found the source upon which this rule is based was a fluorescent sunlamp (FS lamp). The FS spectrum is known and its relative weighting against the action spectra for erythema and the preD3 is significantly different from the solar spectrum used to derive the standard vitamin D effective dose (SDD). The preD3 effectiveness of the solar spectrum per unit erythemal hazard is greater than the FS lamp by a factor of 1.32. Consequently, UV exposure estimates based on Boston reference sunlight, instead of the UV lamp employed in the originating experiments, over estimate UV exposure equivalent to approximately 1000 IU orally by approximately 1/3. This redefinition of SDD impacts risk/benefit assessments of optimal/feasible sun exposure for vitamin D maintenance and the application of Holick's rule to rational public health messages. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  19. Thermal protection from a finite period of heat exposureHeat survival of flight data recorders

    International Nuclear Information System (INIS)

    Rana, Ruhul Amin; Li, Ri

    2015-01-01

    This work relates to developing thermal protection for a finite period of exposure to a high temperature environment. This type of transient heat transfer problem starts with a heating period, which is then followed by a cooling period once the high temperature environment disappears. The study is particularly relevant to the thermal protection of flight data recorders from high temperature flame. In this work, transient heat conduction through a three-concentric-layer configuration is numerically studied, which includes a metal housing, a thermal insulation, and a phase change material. The thermal performance is evaluated using the center temperature changing with time. It is found that the center temperature reaches a peak during cooling period rather than heating period. Time taken to reach the peak and the peak value depend on the sizes and properties of the layers. The properties include latent heat of fusion, melting temperature, heat capacities, and thermal conductivities. Parametric study is conducted to analyze and distinguish the influence of these parameters. The study provides general guidance for determining sizes and selecting materials for the thermal design of flight data recorders. Additionally, the study is also useful for other similar applications, for which thermal management and protection over a period of time is needed. In this paper, analysis starts with a baseline configuration composed of specific materials and sizes. Finite changes are applied to sizes, properties of the materials, and the results are compared to understand the roles of the varied parameters in affecting the thermal protection performance. - Highlights: • We study the thermal design of flight data recorders for heat survival. • Consecutive heating and cooling of 3-layer configuration is investigated. • Influences of sizes and material properties on thermal protection are explored

  20. Decreased Photochemical Efficiency of Photosystem II following Sunlight Exposure of Shade-Grown Leaves of Avocado: Because of, or in Spite of, Two Kinetically Distinct Xanthophyll Cycles?1[W

    Science.gov (United States)

    Jia, Husen; Förster, Britta; Chow, Wah Soon; Pogson, Barry James; Osmond, C. Barry

    2013-01-01

    This study resolved correlations between changes in xanthophyll pigments and photosynthetic properties in attached and detached shade-grown avocado (Persea americana) leaves upon sun exposure. Lutein epoxide (Lx) was deepoxidized to lutein (L), increasing the total pool by ΔL over 5 h, whereas violaxanthin (V) conversion to antheraxanthin (A) and zeaxanthin (Z) ceased after 1 h. During subsequent dark or shade recovery, de novo synthesis of L and Z continued, followed by epoxidation of A and Z but not of L. Light-saturated nonphotochemical quenching (NPQ) was strongly and linearly correlated with decreasing [Lx] and increasing [∆L] but showed a biphasic correlation with declining [V] and increasing [A+Z] separated when V deepoxidation ceased. When considering [ΔL+∆Z], the monophasic linear correlation was restored. Photochemical efficiency of photosystem II (PSII) and photosystem (PSI; deduced from the delivery of electrons to PSI in saturating single-turnover flashes) showed a strong correlation in their continuous decline in sunlight and an increase in NPQ capacity. This decrease was also reflected in the initial reduction of the slope of photosynthetic electron transport versus photon flux density. Generally longer, stronger sun exposures enhanced declines in both slope and maximum photosynthetic electron transport rates as well as photochemical efficiency of PSII and PSII/PSI more severely and prevented full recovery. Interestingly, increased NPQ capacity was accompanied by slower relaxation. This was more prominent in detached leaves with closed stomata, indicating that photorespiratory recycling of CO2 provided little photoprotection to avocado shade leaves. Sun exposure of these shade leaves initiates a continuum of photoprotection, beyond full engagement of the Lx and V cycle in the antenna, but ultimately photoinactivated PSII reaction centers. PMID:23213134

  1. Sunlight-induced DNA damage in human mononuclear cells

    DEFF Research Database (Denmark)

    Møller, Peter; Wallin, Hakan; Holst, Erik

    2002-01-01

    of sunlight was comparable to the interindividual variation, indicating that sunlight exposure and the individual's background were the two most important determinants for the basal level of DNA damage. Influence of other lifestyle factors such as exercise, intake of foods, infections, and age could......In this study of 301 blood samples from 21 subjects, we found markedly higher levels of DNA damage (nonpyrimidine dimer types) in the summer than in the winter detected by single-cell gel electrophoresis. The level of DNA damage was influenced by the average daily influx of sunlight ... to blood sampling. The 3 and 6 day periods before sampling influenced DNA damage the most. The importance of sunlight was further emphasized by a positive association of the DNA damage level to the amount of time the subjects had spent in the sun over a 3 day period prior to the sampling. The effect...

  2. Reversible degradation of inverted organic solar cells by concentrated sunlight

    International Nuclear Information System (INIS)

    Tromholt, Thomas; Krebs, Frederik C; Manor, Assaf; Katz, Eugene A

    2011-01-01

    Concentrated sunlight was used to study the performance response of inverted P3HT:PCBM organic solar cells after exposure to high intensity sunlight. Correlations of efficiency as a function of solar intensity were established in the range of 0.5-15 suns at three different stages: for a pristine cell, after 30 min exposure at 5 suns and after 30 min of rest in the dark. High intensity exposure introduced a major performance decrease for all solar intensities, followed by a partial recovery of the lost performance over time: at 1 sun only 6% of the initial performance was conserved after the high intensity exposure, while after rest the performance had recovered to 60% of the initial value. The timescale of the recovery effect was studied by monitoring the cell performance at 1 sun after high intensity exposure. This showed that cell performance was almost completely restored after 180 min. The transient state is believed to be a result of the breakdown of the diode behaviour of the ZnO electron transport layer by O 2 desorption, increasing the hole conductivity. These results imply that accelerated degradation of organic solar cells by concentrated sunlight is not a straightforward process, and care has to be taken to allow for a sound accelerated lifetime assessment based on concentrated sunlight.

  3. Identification of microRNAs and their targets associated with fruit-bagging and subsequent sunlight re-exposure in the ‘Granny Smith’ apple exocarp using high-throughput sequencing

    Directory of Open Access Journals (Sweden)

    Dong eQu

    2016-02-01

    Full Text Available Bagged fruits of green apple cultivar ‘Granny Smith’ have been found to turn cardinal red after debagging during fruit-ripening in the Loess Plateau region of China. To understand such phenomenon at post-transcriptional level, we have investigated the roles of microRNAs (miRNAs in response to debagging. Three small RNA libraries were primarily constructed from peels of ‘Granny Smith’ apples subjected to bagging followed by sunlight re-exposure treatments (0h, 6h, 1d (debagging, and from peels of apples without any bagging treatments (0h, 6h, 1d. 201 known miRNAs belonging to 43 miRNA families and 220 novel miRNAs were identified via high-throughput sequencing. Some miRNAs were found to be differentially expressed after debagging, which indicated that miRNAs affected anthocyanin accumulation through their target genes in mature apple. To further explore the effect of debagging on miRNAs regulating the expression of anthocyanin regulatory genes, four miRNAs and their target genes regulating anthocyanin accumulation, miR156, miR828, miR858 and miR5072, were compared between green cultivar ‘Granny Smith’ and red cultivar ‘Starkrimson’. Results showed that mdm-miR828 and mdm-miR858 regulated anthocyanin contents in both apple cultivars, while mdm-miR156 only affected anthocyanin accumulation in ‘Granny Smith’, and miR5072 affected anthocyanin accumulation in ‘Starkrimson’. Additional analysis of gene ontology for the differentially expressed miRNAs after debagging treatments and their predicted target genes showed that they were involved in photo-protective response after debagging from 0h to 1d; they might play important roles in fruit development and adaptation to high light stress.

  4. Perceptions of Workplace Heat Exposure and Controls among Occupational Hygienists and Relevant Specialists in Australia.

    Directory of Open Access Journals (Sweden)

    Jianjun Xiang

    Full Text Available With warmer weather projections, workplace heat exposure is presenting a growing challenge to workers' health and safety. Occupational hygienists are the specialist group conducting measurements and providing advice on heat stress management to industry. In order to provide insights into hygienists perceptions on workplace heat exposure, current and future preparedness for extreme heat, and barriers to possible heat adaptation strategies, a self-administered questionnaire survey was conducted during a national conference of the Australian Institute of Occupational Hygienists. Nearly 90% of the 180 respondents were at least moderately concerned about extreme heat and 19% were dissatisfied with current heat stress prevention measures. Barriers recognized by the participants were lack of awareness (68%, insufficient training (56%, unsatisfactory management commitment (52%, and low compliance with prevention policies (40%. The findings suggest a need to refine occupational heat management and prevention strategies.

  5. Effects of concentrated sunlight on organic photovoltaics

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

    2010-01-01

    We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied gradu...

  6. Biological Effects of Sunlight, Ultraviolet Radiation, Visible Light, Infrared Radiation and Vitamin D for Health.

    Science.gov (United States)

    Holick, Michael F

    2016-03-01

    Humans evolved in sunlight and had depended on sunlight for its life giving properties that was appreciated by our early ancestors. However, for more than 40 years the lay press and various medical and dermatology associations have denounced sun exposure because of its association with increased risk for skin cancer. The goal of this review is to put into perspective the many health benefits that have been associated with exposure to sunlight, ultraviolet A (UVA) ultraviolet B (UVB), visible and infrared radiation. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  7. Improved heat transfer modeling of the eye for electromagnetic wave exposures.

    Science.gov (United States)

    Hirata, Akimasa

    2007-05-01

    This study proposed an improved heat transfer model of the eye for exposure to electromagnetic (EM) waves. Particular attention was paid to the difference from the simplified heat transfer model commonly used in this field. From our computational results, the temperature elevation in the eye calculated with the simplified heat transfer model was largely influenced by the EM absorption outside the eyeball, but not when we used our improved model.

  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. 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.

  10. Port Sunlight, essai architectural et social

    OpenAIRE

    Machet, Laurence

    2017-01-01

    The purpose of this article is to examine the city of Port Sunlight, its history, design and originality. Created by William Lever in 1888 in order to house his newly-built soap factory, Port Sunlight is part of the numerous “factory villages” built in the wake of the industrial revolution according to philanthropic and utilitarian principles. But this article intends to show that Port Sunlight differs from other factory towns. Its careful design, elaborate architecture and public facilities ...

  11. Induction of heat-shock proteins and phagocytic function of chicken macrophage following in vitro heat exposure

    International Nuclear Information System (INIS)

    Miller, L.; Qureshi, M.A.

    1992-01-01

    The protein profiles and phagocytic ability of Sephadex-elicited chicken peritoneal macrophages were examined following heat-shock exposure. Macrophage cultures were exposed to various temperatures, time exposures and recovery periods. Densitometric analysis of SDS-PAGE autoradiographs revealed that heat-induced macrophages synthesized three major (23, 70 and 90 kD) heat-shock proteins (HSPs). The optimal temperature and time for induction of these HSPs was 45-46 degrees C for 1 h, with a variable recovery period for each HSP. Macrophages exposed to 45 degrees C for 30 and 60 min were significantly depressed in phagocytosis of uncoated sheep erythrocytes (SE) under 45 degrees C incubation conditions. However, phagocytosis of antibody-coated SE was not affected when compared to 41 degrees C control cultures. Macrophages allowed to recover at 41 degrees C following heat-shock exhibited no alterations in their phagocytic ability for either antibody-coated or uncoated SE. This study suggests that heat shock induces three major HSPs in chicken peritoneal macrophages in addition to maintaining their Fc-mediated phagocytic function while significantly depressing their nonspecific phagocytosis

  12. Heat exposure in cities: combining the dynamics of temperature and population

    Science.gov (United States)

    Hu, L.; Wilhelmi, O.; Uejio, C. K.

    2017-12-01

    Assessment of human exposure to extreme heat requires the distributions of temperature and population. However, both variables are dynamic, thus presenting many challenges in capturing temperature and population patterns spatially and over time in an urban context. This study aims to improve the understanding of spatiotemporal patterns of urban population exposure to heat, taking Chicago, USA as an example. We estimate the hourly, geographically variable, population distribution considering commute of workers and students in a regular weekday and analyze the diurnal air temperature patterns during different meteorological conditions from satellite observations. The results show a relatively larger temperature increase in less urbanized areas during extreme heat events (EHEs), resulting in a spatially homogeneous temperature distribution over Chicago Metropolitan area. A lake cooling effect is weaker during EHEs. Population dynamics due to daily commute determine higher population density in more urbanized areas during daytime. The city-wide analysis reveals that the exposure is more sensitive to the nighttime temperature increases, and EHEs enhance this sensitivity. The high exposure hotspots are identified at the northwest Chicago, Cicero and Oak Park areas, where the influence from Lake Michigan is weakened, while the spatial extent of high outdoor exposure areas varies diurnally. This study's findings have potential to better inform general heat mitigation strategies during hot summer months and facilitate emergency response during EHEs. Availability of remotely-sensed temperature observations as well as the workers and students commute-adjusted population data allows for the adoption of this study's methodology in other major metropolitan areas. A better understanding of space-time patterns of urban population's exposure to heat will further enable local decision makers to mitigate extreme heat health risks and develop more targeted heat preparedness and

  13. Increased hospital admissions associated with extreme-heat exposure in King County, Washington, 1990-2010.

    Science.gov (United States)

    Isaksen, Tania Busch; Yost, Michael G; Hom, Elizabeth K; Ren, You; Lyons, Hilary; Fenske, Richard A

    2015-01-01

    Increased morbidity and mortality have been associated with extreme heat events, particularly in temperate climates. Few epidemiologic studies have considered the impact of extreme heat events on hospitalization rates in the Pacific Northwest region. This study quantifies the historic (May to September 1990-2010) heat-morbidity relationship in the most populous Pacific Northwest County, King County, Washington. A relative risk (RR) analysis was used to explore the association between heat and all non-traumatic hospitalizations on 99th percentile heat days, whereas a time series analysis using a piecewise linear model approximation was used to estimate the effect of heat intensity on hospitalizations, adjusted for temporal trends and day of the week. A non-statistically significant 2% [95% CI: 1.02 (0.98, 1.05)] increase in hospitalization risk, on a heat day vs. a non-heat day, was noted for all-ages and all non-traumatic causes. When considering the effect of heat intensity on admissions, we found a statistically significant 1.59% (95% CI: 0.9%, 2.29%) increase in admissions per degree increase in humidex above 37.4°C. Admissions stratified by cause and age produced statistically significant results with both relative risk and time series analyses for nephritis and nephrotic syndromes, acute renal failure, and natural heat exposure hospitalizations. This study demonstrates that heat, expressed as humidex, is associated with increased hospital admissions. When stratified by age and cause of admission, the non-elderly age groups (<85 years) experience significant risk for nephritis and nephrotic syndromes, acute renal failure, natural heat exposure, chronic obstructive pulmonary disease, and asthma hospitalizations.

  14. Ability to Discriminate Between Sustainable and Unsustainable Heat Stress Exposures-Part 2: Physiological Indicators.

    Science.gov (United States)

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

    2017-07-01

    There are times when it is not practical to assess heat stress using environmental metrics and metabolic rate, and heat strain may provide an alternative approach. Heat strain indicators have been used for decades as tools for monitoring physiological responses to work in hot environments. Common indicators of heat strain are body core temperature (assessed here as rectal temperature Tre), heart rate (HR), and average skin temperature (Tsk). Data collected from progressive heat stress trials were used to (1) demonstrate if physiological heat strain indicators (PHSIs) at the upper limit of Sustainable heat stress were below generally accepted limits; (2) suggest values for PHSIs that demonstrate a Sustainable level of heat stress; (3) suggest alternative PHSIs; and (4) determine if metabolic rate was an effect modifier. Two previous progressive heat stress studies included 176 trials with 352 pairs of Sustainable and Unsustainable exposures over a range of relative humidities and metabolic rates using 29 participants. To assess the discrimination ability of PHSIs, conditional logistic regression and stepwise logistic regression were used to find the best combinations of predictors of Unsustainable exposures. The accuracy of the models was assessed using receiver operating characteristic curves. Current recommendations for physiological heat strain limits were associated with probabilities of Unsustainable greater than 0.5. Screening limits for Sustainable heat stress were Tre of 37.5°C, HR of 105 bpm, and Tsk of 35.8°C. Tsk alone resulted in an area under the curve of 0.85 and the combination of Tsk and HR (area under the curve = 0.88) performed the best. The adjustment for metabolic rate was statistically significant for physiological strain index or ∆Tre-sk as main predictors, but its effect modification was negligible and could be ignored. Based on the receiver operating characteristic curve, PHSIs (Tre, HR, and Tsk) can accurately predict Unsustainable heat

  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. A Case-Crossover Study of Heat Exposure and Injury Risk in Outdoor Agricultural Workers.

    Science.gov (United States)

    Spector, June T; Bonauto, David K; Sheppard, Lianne; Busch-Isaksen, Tania; Calkins, Miriam; Adams, Darrin; Lieblich, Max; Fenske, Richard A

    2016-01-01

    Recent research suggests that heat exposure may increase the risk of traumatic injuries. Published heat-related epidemiological studies have relied upon exposure data from individual weather stations. To evaluate the association between heat exposure and traumatic injuries in outdoor agricultural workers exposed to ambient heat and internal heat generated by physical activity using modeled ambient exposure data. A case-crossover study using time-stratified referent selection among 12,213 outdoor agricultural workers with new Washington State Fund workers' compensation traumatic injury claims between 2000 and 2012 was conducted. Maximum daily Humidex exposures, derived from modeled meteorological data, were assigned to latitudes and longitudes of injury locations on injury and referent dates. Conditional logistic regression was used to estimate odds ratios of injury for a priori daily maximum Humidex categories. The mean of within-stratum (injury day and corresponding referent days) standard deviations of daily maximum Humidex was 4.8. The traumatic injury odds ratio was 1.14 (95% confidence interval 1.06, 1.22), 1.15 (95% confidence interval 1.06, 1.25), and 1.10 (95% confidence interval 1.01, 1.20) for daily maximum Humidex of 25-29, 30-33, and ≥34, respectively, compared to < 25, adjusted for self-reported duration of employment. Stronger associations were observed during cherry harvest duties in the June and July time period, compared to all duties over the entire study period. Agricultural workers laboring in warm conditions are at risk for heat-related traumatic injuries. Combined heat-related illness and injury prevention efforts should be considered in high-risk populations exposed to warm ambient conditions in the setting of physical exertion.

  17. A Case-Crossover Study of Heat Exposure and Injury Risk in Outdoor Agricultural Workers.

    Directory of Open Access Journals (Sweden)

    June T Spector

    Full Text Available Recent research suggests that heat exposure may increase the risk of traumatic injuries. Published heat-related epidemiological studies have relied upon exposure data from individual weather stations.To evaluate the association between heat exposure and traumatic injuries in outdoor agricultural workers exposed to ambient heat and internal heat generated by physical activity using modeled ambient exposure data.A case-crossover study using time-stratified referent selection among 12,213 outdoor agricultural workers with new Washington State Fund workers' compensation traumatic injury claims between 2000 and 2012 was conducted. Maximum daily Humidex exposures, derived from modeled meteorological data, were assigned to latitudes and longitudes of injury locations on injury and referent dates. Conditional logistic regression was used to estimate odds ratios of injury for a priori daily maximum Humidex categories.The mean of within-stratum (injury day and corresponding referent days standard deviations of daily maximum Humidex was 4.8. The traumatic injury odds ratio was 1.14 (95% confidence interval 1.06, 1.22, 1.15 (95% confidence interval 1.06, 1.25, and 1.10 (95% confidence interval 1.01, 1.20 for daily maximum Humidex of 25-29, 30-33, and ≥34, respectively, compared to < 25, adjusted for self-reported duration of employment. Stronger associations were observed during cherry harvest duties in the June and July time period, compared to all duties over the entire study period.Agricultural workers laboring in warm conditions are at risk for heat-related traumatic injuries. Combined heat-related illness and injury prevention efforts should be considered in high-risk populations exposed to warm ambient conditions in the setting of physical exertion.

  18. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools.

    Science.gov (United States)

    Burdett, Garry J; Dewberry, Kirsty; Staff, James

    2016-01-01

    The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml(-1)) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml(-1). Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated

  19. Effects of gamma rays, ultraviolet radiation, sunlight, microwaves and electromagnetic fields on gene expression mediated by human immunodeficiency virus promoter

    International Nuclear Information System (INIS)

    Libertin, C.R.; Woloschak, G.E.; Panozzo, J.; Groh, K.R.; Chang-Liu, Chin-Mei; Schreck, S.

    1994-01-01

    Previous work by our group and others has shown the modulation of human immunodeficiency virus (HIV) promoter or long terminal repeat (LTR) after exposure to neutrons and ultraviolet radiations. Using HeLa cells stably transfected with a construct containing the chloramphenicol acetyl transferase (CAT) gene, the transcription of which is mediated by the HIV-LTR, we designed experiments to examine the effects of exposure to different types of radiation (such as γ rays, ultraviolet and sunlight irradiations, electromagnetic fields and microwaves) in HIV-LTR-driven expression of CAT. These results demonstrated ultraviolet-light-induced transcription from the HIV promoter, as has been shown by others. Exposure to other DNA-damaging agents such as γ rays and sunlight (with limited exposures) had no significant effect on transcription mediated by HIV-LTR, suggesting that induction of HIV is not mediated by just any type of DNA damage but rather may require specific types of DNA damage. Microwaves did not cause cell killing when cells in culture were exposed in high volumes of medium, and the same cells showed no changes in expression. When microwave exposure was carried out in low volumes of medium (so that excessive heat was generated) induction of HIV-LTR transcription (as assayed by CAT activity) was evident. Electromagnetic field exposures had no effect on expression of HIV-LTR. These results demonstrate that not all types of radiation and not all DNA-damaging agents are capable of inducing HIV. We hypothesize that induction of HIV transcription may be mediated by several different signals exposure to radiation. 22 refs., 8 figs

  20. Passive radiative cooling below ambient air temperature under direct sunlight.

    Science.gov (United States)

    Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

    2014-11-27

    Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day.

  1. Transcription of four Rhopalosiphum padi (L.) heat shock protein genes and their responses to heat stress and insecticide exposure.

    Science.gov (United States)

    Li, Yuting; Zhao, Qi; Duan, Xinle; Song, Chunman; Chen, Maohua

    2017-03-01

    The bird cherry-oat aphid, Rhopalosiphum padi (L.), a worldwide destructive pest, is more heat tolerant than other wheat aphids, and it has developed resistance to different insecticides. Heat shock proteins (HSPs) play an important role in coping with environmental stresses. To investigate Hsp transcriptional responses to heat and insecticide stress, four full-length Hsp genes from R. padi (RpHsp60, RpHsc70, RpHsp70-1, and RpHsp70-2) were cloned. Four RpHsps were expressed during all R. padi developmental stages, but at varying levels. The mRNA levels of RpHsps were increased under thermal stress and reached maximal induction at a lower temperature (36°C) in the alate morph than in the apterous morph (37°C or 38°C). RpHsp expressions under heat stress suggest that RpHsp70-1 and RpHsp70-2 are inducible in both apterous and alate morphs, RpHsc70 is only heat-inducible in apterous morph, and RpHsp60 exhibits poor sensitivity to heat stress. The pretreatment at 37°C significantly increase both the survival rate and the RpHsps expression level of R. padi at subsequent lethal temperature. Under exposure to two sublethal concentrations (LC 10 and LC 30 ) of beta-cypermethrin, both RpHsp70-1 and RpHsp70-2 expressions were induced and reached a maximum 24h after exposure. In contrast, expression of RpHsp60 was not induced by either sublethal concentration of beta-cypermethrin. Moreover, the responses of RpHsp70-1 and RpHsp70-2 to heat shock were more sensitive than those to beta-cypermethrin. These results suggest that induction of RpHsp expression is related to thermal tolerance, and that RpHsp70-1 and RpHsp70-2 are the primary genes involved in the response to both heat and pesticide stress. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. 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 probabili.......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.......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...... that different levels of exposure result in disease. The overall goal of this study was to evaluate the impact of variability of exposure patterns and uncertainty of exposure data in burden of disease estimates. We focus on the first phase of burden of disease modelling, i.e. the estimation of exposure...

  3. Exposure calculations for the FRG isotopic heat source project environmental assessment

    International Nuclear Information System (INIS)

    Metcalf, I.L.

    1997-01-01

    The report documents the maximum exposure for transfer of the Federal Republic of Germany (FRG) Isotopic Heat Sources from the 324 Building and placed in interim storage at the Central Waste Complex (CWC). These results are to be reported in the Environmental Assessment DOE-EA- 1 21 1

  4. 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.

  5. Nasopharyngeal carcinoma in Malaysian Chinese: occupational exposures to particles, formaldehyde and heat.

    Science.gov (United States)

    Armstrong, R W; Imrey, P B; Lye, M S; Armstrong, M J; Yu, M C; Sani, S

    2000-12-01

    During 1990-1992, 282 Chinese residents of Selangor and the Federal Territory, Malaysia with histologically confirmed nasopharyngeal carcinoma (NPC) were interviewed about occupational history, diet, alcohol consumption, and tobacco use, as were an equal number of Malaysian Chinese population controls, pair-matched to cases by age and sex. Exposures to 20 kinds of workplace substances, solar and industrial heat, and cigarette smoke, were analysed by univariate and multivariate methods. Nasopharyngeal carcinoma was associated with occupational exposures to construction, metal and wood dusts; motor fuel and oil; paints and varnishes; certain other chemicals; industrial heat; solar heat from outdoor occupations; certain smokes; cigarette smoking; and childhood exposure to parental smoking. After adjustment for risk from diet and cigarette smoke, only wood dust (OR = 2.36; 95% CI : 1.33- 4.19), and industrial heat (OR = 2.21; 95% CI : 1.12-4.33) remained clearly associated. Wood dust remained statistically significant after further adjustment for social class. No significant crude or adjusted association was found between NPC and formaldehyde (adjusted OR = 0.71; 95% CI : 0.34-1.43). This study supports previous findings that some occupational inhalants are risk factors for NPC. The statistical effect of wood dust remained substantial after adjustment for diet, cigarette smoke, and social class. Intense industrial heat emerged as a previously unreported risk factor, statistically significant even after adjustment for diet and cigarette smoke. No association was found between NPC and formaldehyde.

  6. Influence of thermoluminescence signal for debris flow surface materials by sunlight bleaching

    International Nuclear Information System (INIS)

    Song Bo; Wei Mingjian; He Youbing; Zhou Rui; Zhao Qiuyue; Zhang Bin

    2013-01-01

    Thermoluminescence was utilized for measuring the thermoluminescence signals of the standard debris flow samples which were bleached by simulated sunlight and debris flow samples after real sunlight bleaching. The experiment results demonstrate that light bleaching phenomenon of the debris flow occurs when it experiences a period of exposure. The thermoluminescence signal of the samples weakens gradually with the increase of depth. The optical bleaching phenomenon is obvious. Within a certain depth, light bleaching phenomenon is enhanced with the increase of light intensity. The annealing depth of simulated sunlight bleaching experiment is about 1 mm, and the actual annealing depth of sunlight bleaching is about 6 mm. According to the equivalent dose variation with depth, the mud of natural debris flow can be divided into two stages. It has fundamental significance in the application of thermoluminescence dating techniques to divide the stages of debris flow sediments. (authors)

  7. Sunlight suppressing rejection of 280- to 320-nm UV-radiation-induced skin tumors in mice

    International Nuclear Information System (INIS)

    Morison, W.L.; Kelley, S.P.

    1985-01-01

    Repeated exposure of female C3H/HeNCR- mice to sunlight prevented the normal immunologic rejection of a UV-induced tumor. This systemic immunologic alteration was transferred to syngeneic lethally X-irradiated animals with lymphoid cells from mice exposed to sunlight. The lymphoid cells also were able to suppress the capacity of lymphoid cells from normal animals to reject a UV-induced tumor. The 295- to 320-nm wave band appeared to be responsible for this immunosuppressive effect of sunlight because suppression was prevented by filtration of the radiation through Mylar and by application of a sunscreen containing para-aminobenzoic acid. These observations may have importance in understanding the pathogenesis of sunlight-induced skin cancer in humans

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

    Directory of Open Access Journals (Sweden)

    Nebojsa Jasnic

    2010-04-01

    Full Text Available The increased ambient temperature affects the function of hypothalamic-pituitary-adrenal (HPA axis. Since thecorrelation among vasopressin (VP, adrenocorticotropic hormone (ACTH and corticosterone (CORT responses to variousstressors have been long recognized, the aim of this study was to reveal the aforementioned hormones production andmorphology of the pituitary gland after exposure to acute heat. Rats were exposed to high ambient temperature (38°C for20 or 60 minutes. The circulating hormones were determined by an ELISA test or chemiluminescence's method. The resultsobtained show the elevation in ACTH and CORT secretion depending on the duration of heat exposure. The VP concentrationincreased only after prolonged exposure to heat (60 min. The pituitary morphology was examined by routine and fluorescentimmunohistochemistry as well as electron microscopy. Observed changes in the anterior and posterior pituitarywell corresponded to circulating hormones, regarding the volume density of ACTH-immunopositive cells, percentage ofACTH immunopositive area v. total area and number of VP-immunopositive containing varicose fibers per total area. Acuteheat exposure also induced changes in shapes of ACTH-immunopositive cells. Cells appeared stellate with numerous slendercytoplasmic processes and degranulated, which is the most obvious after 20 min. In addition, immunopositivity ofendothelial and anterior pituitary cells for VP suggests its influence on ACTH secretion.

  9. 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

    2018-03-01

    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

  10. Sunlight technologies for photochemical deactivation of organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Acher, A.; Fischer, E.; Tornheim, R. [The Volcani Center, Inst. of Soils and Water, Bet Dagan (Israel); Manor, Y. [Sheba Medical Center, Central Virology Lab., Ramat Gan (Israel)

    1997-12-31

    Sensitized-photochemical oxidation methods aimed at use in water treatment technologies for deactivation of biotic (microorganisms) and/or of xenobiotic (pesticides) pollutants in water were developed using global solar radiation or concentrated sunlight (up to 250 suns). The solar global radiation was used either for detoxification of industrial waste water from a pesticide factory to allow their discharge into the urban sewer, or for disinfection of domestric effluents to be used in crop irrigation. The disinfection process was eventually carried out in an experimental pilot-scale plant, capable of disinfection up to 50 m{sup 3}/h of effluent supplied by an activated sludge sewage treatment plant located in Tel-Aviv area. The treated effluents did not show any regrowth of the microorganisms during 7 days. The solar concentrated radiation experiments performed using facilities of the Sun Tower of The Weizman Institute of Science, Rehovot. The concentrated sunlight was provided by different combination of several computer controlled heliostates, up to 8, that track the sun and focus the received sunlight onto the target situated on the roof of the sun-tower. The sunlight intensities measured on the target reached up to 200 kW/m{sup 2}. The experiments were performed either batch- or continuous-wise. The water-samples exposed to disinfection were the above effluent, filtered and supplemented with vaccine strain poliovirus or with different concentrations of an industrial potential pollutant (bromacil), MB 2 mg/L and two concentrations of dissolved oxygen (8.0 or 40.0 mg O{sub 2}/L). An exposure time of 2-3 seconds at 150 kW/m{sup 2} was decreased the microorganisms alive (counts) by five orders of magnitude. A comparison between the two above water treatment technologies is presented. (orig./SR)

  11. 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.

  12. The effect of UV exposure and heat treatment on crystallization behavior of photosensitive glasses

    Science.gov (United States)

    Kıbrıslı, Orhan; Ersundu, Ali Erçin

    2018-05-01

    In this study, photosensitive glasses in the Na2O-ZnO-Al2O3-SiO2 system with photosensitizing agents (cerium, silver, tin, antimony) and halogenides (NaF and KBr) were synthesized through a conventional melt-quenching technique. The crystallization mechanism was investigated for solely heat-treated and UV-exposed + heat-treated samples using differential thermal analysis (DTA), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) techniques to understand the effect of UV exposure on crystallization behavior of photosensitive glasses. Accordingly, non-isothermal DTA measurements were performed at different heating rates to determine crystallization peak, T p, and onset, T c, temperatures. For solely heat-treated samples, the kinetic parameters such as the Avrami constant, n, and morphology index, m, were calculated as 1 from the Ozawa method indicating surface crystallization and the value of crystallization activation energy was calculated as 944 kJ/mol using modified Kissinger method. On the contrary, bulk crystallization was found to be predominant for UV exposed + heat-treated samples revealing that UV exposure is the primary cause of bulk crystallization in photosensitive glasses.

  13. Carcinogenic effect of sequential artificial sunlight and UV-A irradiation in hairless mice. Consequences for solarium 'therapy'

    International Nuclear Information System (INIS)

    Staberg, B.; Wulf, H.C.; Poulsen, T.; Klemp, P.; Brodthagen, H.

    1983-01-01

    The carcinogenic effect of artificial UV sunlight followed by UV-A irradiation in human solaria doses has been studied with the use of the hairless mouse as an animal model. Artificial sunlight exposure alone induced only a moderate skin tumor incidence (animals with at least one tumor) of 0.15 after one year, and UV-A irradiation alone induced no tumor formation. However, the combination of artificial sunlight exposure and subsequent UV-A irradiation significantly increased the tumor incidence to 0.72. We conclude that, in humans, tanning with UV-A for cosmetic purposes may not be an innocuous procedure

  14. 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

  15. 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.

  16. Combined impact of transient heat loads and steady-state plasma exposure on tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Alexander, E-mail: A.Huber@fz-juelich.de [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Wirtz, Marius; Sergienko, Gennady; Steudel, Isabel [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Arakcheev, Aleksey; Burdakov, Aleksander [Budker Institute of Nuclear Physics (BINP), Novosibirsk 630090 (Russian Federation); Esser, Hans Guenter; Freisinger, Michaele; Kreter, Arkadi; Linke, Jochen; Linsmeier, Christian; Mertens, Philippe; Möller, Sören; Philipps, Volker; Pintsuk, Gerald; Reinhart, Michael; Schweer, Bernd [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Shoshin, Andrey [Budker Institute of Nuclear Physics (BINP), Novosibirsk 630090 (Russian Federation); Terra, Alexis; Unterberg, Bernhard [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany)

    2015-10-15

    Highlights: • W-samples under combined loading conditions show a lower damage threshold. • The pre-loaded W-samples show a lower damage threshold due to the D- embrittlement. • Pronounced increase of the D retention has been observed during the combined loads. • Enhanced blister formation has been observed under combined loading conditions. - Abstract: Cracking thresholds and crack patterns in tungsten targets have been studied in recent experiments after repetitive ITER-like ELM heat pulses in combination with plasma exposure in PSI-2 (Γ{sub target} = 2.5–4.0 × 10{sup 21} m{sup −2} s{sup −1}, ion energy on surface E{sub ion} = 60 eV, T{sub e} ≈ 10 eV). The heat pulses were simulated by laser irradiation. A Nd:YAG laser with energy per pulse of up to 32 J and a duration of 1 ms at the fundamental wavelength (λ = 1064 nm, repetition rate 0.5 Hz) was used to irradiate ITER-grade W samples with repetitive heat loads. In contrast to pure thermal exposure with a laser beam where the damage threshold under pure heat loads for ITER-grade W lies between 0.38 and 0.76 GW/m{sup 2}, the experiments with pre-loaded W-samples as well as under combined loading conditions show a lower damage threshold of 0.3 GW/m{sup 2}. This is probably due to deuterium embrittlement and/or a higher defect concentration in a region close to the surface due to supersaturation with deuterium. A pronounced increase in the D retention (more than a factor of five) has been observed during the combined transient heat loads and plasma exposure. Enhanced blister formation has been observed under these combined loading conditions.

  17. Combined impact of transient heat loads and steady-state plasma exposure on tungsten

    International Nuclear Information System (INIS)

    Huber, Alexander; Wirtz, Marius; Sergienko, Gennady; Steudel, Isabel; Arakcheev, Aleksey; Burdakov, Aleksander; Esser, Hans Guenter; Freisinger, Michaele; Kreter, Arkadi; Linke, Jochen; Linsmeier, Christian; Mertens, Philippe; Möller, Sören; Philipps, Volker; Pintsuk, Gerald; Reinhart, Michael; Schweer, Bernd; Shoshin, Andrey; Terra, Alexis; Unterberg, Bernhard

    2015-01-01

    Highlights: • W-samples under combined loading conditions show a lower damage threshold. • The pre-loaded W-samples show a lower damage threshold due to the D- embrittlement. • Pronounced increase of the D retention has been observed during the combined loads. • Enhanced blister formation has been observed under combined loading conditions. - Abstract: Cracking thresholds and crack patterns in tungsten targets have been studied in recent experiments after repetitive ITER-like ELM heat pulses in combination with plasma exposure in PSI-2 (Γ_t_a_r_g_e_t = 2.5–4.0 × 10"2"1 m"−"2 s"−"1, ion energy on surface E_i_o_n = 60 eV, T_e ≈ 10 eV). The heat pulses were simulated by laser irradiation. A Nd:YAG laser with energy per pulse of up to 32 J and a duration of 1 ms at the fundamental wavelength (λ = 1064 nm, repetition rate 0.5 Hz) was used to irradiate ITER-grade W samples with repetitive heat loads. In contrast to pure thermal exposure with a laser beam where the damage threshold under pure heat loads for ITER-grade W lies between 0.38 and 0.76 GW/m"2, the experiments with pre-loaded W-samples as well as under combined loading conditions show a lower damage threshold of 0.3 GW/m"2. This is probably due to deuterium embrittlement and/or a higher defect concentration in a region close to the surface due to supersaturation with deuterium. A pronounced increase in the D retention (more than a factor of five) has been observed during the combined transient heat loads and plasma exposure. Enhanced blister formation has been observed under these combined loading conditions.

  18. 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.

  19. Sunlight inactivation of Escherichia coli in waste stabilization microcosms in a sahelian region (Ouagadougou, Burkina Faso).

    Science.gov (United States)

    Maïga, Ynoussa; Denyigba, Kokou; Wethe, Joseph; Ouattara, Aboubakar Sidiki

    2009-02-09

    Experiments on sunlight inactivation of Escherichia coli were conducted from November 2006 to June 2007 in eight outdoors microcosms with different depths filled with maturation pond wastewater in order to determine pond depth influence on sunlight inactivation of E. coli. The long-term aim was to maximize sunlight inactivation of waterborne pathogens in waste stabilization ponds (WSPs) in sahelian regions where number of sunny days enable longer exposure of wastewater to sunlight. The inactivation was followed during daylight from 8.00 h to 17.00 h and during the night. Sunlight inactivation rates (K(S)), as a function of cumulative global solar radiation (insolation), were 16 and 24 times higher than the corresponding dark inactivation (K(D)) rates, respectively in cold and warm season. In warm season, E. coli was inactivated far more rapidly. Inactivation of E. coli follows the evolution of radiation during the day. In shallow depth microcosms, E. coli was inactivated far more rapidly than in high depth microcosms. The physical chemical parameters [pH, dissolved oxygen (DO)] of microcosms water were higher in shallow depth microcosms than in high depth microcosms suggesting a synergistic effect of sunlight and these parameters to damage E. coli. To increase the efficiency of the elimination of waterborne bacteria, the use of maturation ponds with intermediate depths (0.4m) would be advisable in view of the high temperatures and thus evaporation recorded in sahelian regions.

  20. Workers’ perceptions of climate change related extreme heat exposure in South Australia: a cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Jianjun Xiang

    2016-07-01

    Full Text Available Abstract Background Occupational exposure to extreme heat without sufficient protection may not only increase the risk of heat-related illnesses and injuries but also compromise economic productivity. With predictions of more frequent and intense bouts of hot weather, workplace heat exposure is presenting a growing challenge to workers’ health and safety. This study aims to investigate workers’ perceptions and behavioural responses towards extreme heat exposure in a warming climate. Methods A cross-sectional questionnaire survey was conducted in 2012 in South Australia among selected outdoor industries. Workers’ heat risk perceptions were measured in the following five aspects: concerns about heat exposure, attitudes towards more training, policy and guideline support, the adjustment of work habits, and degree of satisfaction of current preventive measures. Bivariate and multivariate logistic regression analyses were used to identify factors significantly associated with workers’ heat perceptions. Results A total of 749 respondents participated in this survey, with a response rate of 50.9 %. A little more than half (51.2 % of respondents were moderately or very much concerned about workplace heat exposure. Factors associated with workers’ heat concerns included age, undertaking very physically demanding work, and the use of personal protective equipment, heat illness history, and injury experience during hot weather. Less than half (43.4 % of the respondents had received heat-related training. Workers aged 25–54 years and those with previous heat-related illness/injury history showed more supportive attitudes towards heat-related training. The provision of cool drinking water was the most common heat prevention measure. A little more than half (51.4 % of respondents were satisfied with the current heat prevention measures. About two-thirds (63.8 % of respondents agreed that there should be more heat-related regulations and

  1. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    . A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...... were degraded resulting in acceleration factors in the range of 19-55. This shows that concentrated sunlight can be used as qualitatively to determine the lifetime of polymers under highly accelerated conditions....

  2. Effect of Heat Exposure on the Fatigue Properties of AA7050 Friction Stir Welds

    Science.gov (United States)

    White, B. C.; Rodriguez, R. I.; Cisko, A.; Jordon, J. B.; Allison, P. G.; Rushing, T.; Garcia, L.

    2018-05-01

    This work examines the effect of heat exposure on the subsequent monotonic and fatigue properties of friction stir-welded AA7050. Mechanical characterization tests were conducted on friction stir-welded specimens as-welded (AW) and specimens heated to 315 °C in air for 20 min. Monotonic testing revealed high joint efficiencies of 98% (UTS) in the AW specimens and 60% in the heat-damaged (HD) specimens. Experimental results of strain-controlled fatigue testing revealed shorter fatigue lives for the HD coupons by nearly a factor of four, except for the highest strain amplitude tested. Postmortem fractography analysis found similar crack initiation or propagation behavior between the AW and HD specimens; however, the failure locations for the AW were predominantly in the heat-affected zone, while the HD specimens also failed in the stir zone. Microhardness measurements revealed a relatively uniform strength profile in the HD group, accounting for the variety of failure locations observed. The differences in both monotonic and cyclic properties observed between the AW and HD specimens support the conclusion that the heat damage (315 °C at 20 min) acts as an over-aging and a quasi-annealing treatment.

  3. Separate and combined effects of exposure to heat stress and mental fatigue on endurance exercise capacity in the heat.

    Science.gov (United States)

    Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip

    2017-01-01

    This study investigated the effects of exposure to pre-exercise heat stress and mental fatigue on endurance exercise capacity in a hot environment. Eight volunteers completed four cycle exercise trials at 80% maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50% relative humidity. The four trials required them to complete a 90 min pre-exercise routine of either a seated rest (CON), a prolonged demanding cognitive task to induce mental fatigue (MF), warm water immersion at 40 °C during the last 30 min to induce increasing core temperature (WI), or a prolonged demanding cognitive task and warm water immersion at 40 °C during the last 30 min (MF + WI). Core temperature when starting exercise was higher following warm water immersion (~38 °C; WI and MF + WI) than with no water immersion (~36.8 °C; CON and MF, P fatigue when commencing exercise was higher following cognitive task (MF and MF + WI) than with no cognitive task (CON and WI; P stress or mental fatigue, and this response is synergistically increased during combined exposure to them.

  4. Assessing Vulnerability to Urban Heat: A Study of Disproportionate Heat Exposure and Access to Refuge by Socio-Demographic Status in Portland, Oregon

    Directory of Open Access Journals (Sweden)

    Jackson Voelkel

    2018-03-01

    Full Text Available Extreme urban heat is a powerful environmental stressor which poses a significant threat to human health and well-being. Exacerbated by the urban heat island phenomenon, heat events are expected to become more intense and frequent as climate change progresses, though we have limited understanding of the impact of such events on vulnerable populations at a neighborhood or census block group level. Focusing on the City of Portland, Oregon, this study aimed to determine which socio-demographic populations experience disproportionate exposure to extreme heat, as well as the level of access to refuge in the form of public cooling centers or residential central air conditioning. During a 2014 heat wave, temperature data were recorded using a vehicle-traverse collection method, then extrapolated to determine average temperature at the census block group level. Socio-demographic factors including income, race, education, age, and English speaking ability were tested using statistical assessments to identify significant relationships with heat exposure and access to refuge from extreme heat. Results indicate that groups with limited adaptive capacity, including those in poverty and non-white populations, are at higher risk for heat exposure, suggesting an emerging concern of environmental justice as it relates to climate change. The paper concludes by emphasizing the importance of cultural sensitivity and inclusion, in combination with effectively distributing cooling centers in areas where the greatest burden befalls vulnerable populations.

  5. Assessing Vulnerability to Urban Heat: A Study of Disproportionate Heat Exposure and Access to Refuge by Socio-Demographic Status in Portland, Oregon.

    Science.gov (United States)

    Voelkel, Jackson; Hellman, Dana; Sakuma, Ryu; Shandas, Vivek

    2018-03-30

    Extreme urban heat is a powerful environmental stressor which poses a significant threat to human health and well-being. Exacerbated by the urban heat island phenomenon, heat events are expected to become more intense and frequent as climate change progresses, though we have limited understanding of the impact of such events on vulnerable populations at a neighborhood or census block group level. Focusing on the City of Portland, Oregon, this study aimed to determine which socio-demographic populations experience disproportionate exposure to extreme heat, as well as the level of access to refuge in the form of public cooling centers or residential central air conditioning. During a 2014 heat wave, temperature data were recorded using a vehicle-traverse collection method, then extrapolated to determine average temperature at the census block group level. Socio-demographic factors including income, race, education, age, and English speaking ability were tested using statistical assessments to identify significant relationships with heat exposure and access to refuge from extreme heat. Results indicate that groups with limited adaptive capacity, including those in poverty and non-white populations, are at higher risk for heat exposure, suggesting an emerging concern of environmental justice as it relates to climate change. The paper concludes by emphasizing the importance of cultural sensitivity and inclusion, in combination with effectively distributing cooling centers in areas where the greatest burden befalls vulnerable populations.

  6. 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.

  7. Associations between heat exposure, vigilance, and balance performance in summer tree fruit harvesters.

    Science.gov (United States)

    Spector, June T; Krenz, Jennifer; Calkins, Miriam; Ryan, Dawn; Carmona, Jose; Pan, Mengjie; Zemke, Anna; Sampson, Paul D

    2018-02-01

    We sought to evaluate potential mediators of the relationship between heat exposure and traumatic injuries in outdoor agricultural workers. Linear mixed models were used to estimate associations between maximum work-shift Wet Bulb Globe Temperature (WBGT max ) and post-shift vigilance (reaction time) and postural sway (total path length) in a cross-sectional sample of 46 Washington State tree fruit harvesters in August-September 2015. The mean (SD) WBGT max was 27.4 (3.2)°C in August and 21.2 (2.0)°C in September. The mean pre-work-shift participant urine specific gravity indicated minimal dehydration. Twenty-four percent of participants exhibited possible excessive sleepiness. There was no association between WBGT max and post-shift reaction time or total path length. Heat exposure was not associated with impaired vigilance or balance in this study, in which the overall mean (SD) WBGT max was 25.9 (4.2)°C. However, the study identified opportunities to ensure adequate pre-work-shift hydration and to optimize sleep and work-shift timing in order to reduce occupational injury and heat-related illness risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. ESCA and electron diffraction studies of InP surface heated under As molecular beam exposure

    International Nuclear Information System (INIS)

    Sugiura, Hideo; Yamaguchi, Masafumi; Shibukawa, Atsushi

    1983-01-01

    Chemical composition of InP substrate surface heattreated under As molecular beam exposure in an ultrahigh vacuum chamber was studied with ESCA, and surface reconstruction of the substrate was examined by in-situ electron diffraction. The InP substrate heated under the exposure of As molecular beam has mirror surface up to 590 0 C while the surface of InP heated above 400 0 C in vacuum is roughened. The ESCA study shows that thin InAs layer (thickness 0 C under the exposure of As. The electron diffraction study indicates that the InP is cleaned at about 500 0 C in As pressures of 10 -7 - 10 -5 Torr. The InP surface is prevented from thermally decomposing by the coverage of the InAs layer, which may be formed through the following process: 2InPO 4 + As 4 → 2InAs + P 2 O 5 + As 2 O 3 . (author)

  9. Cathodic protection of carbon steel in natural seawater: Effect of sunlight radiation

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, Alessandro [Istituto per l' Energetica e le Interfasi, IENI - CNR, Milano, via Roberto Cozzi 53 20125 Milano (Italy)], E-mail: alessandro.benedetti@cnr.it; Magagnin, Luca [Dip. Chimica, Materiali e Ing. Chimica G. Natta, Politecnico di Milano, via Mancinelli 7, 20131 Milano (Italy); Passaretti, Francesca [Istituto per l' Energetica e le Interfasi IENI - CNR, Lecco, c.so Promessi Sposi 29, 23900 Lecco (Italy); Chelossi, Elisabetta; Faimali, Marco [Istituto di Scienze Marine, ISMAR- CNR - Via De Marini 6, 16149, Genova (Italy); Montesperelli, Giampiero [Universita di Roma - Tor Vergata, Dipartimento di Scienze e Tecnologie Chimiche, Via della Ricerca Scientifica 00133, Roma (Italy)

    2009-11-01

    Cathodic protection of metals in seawater is known to be influenced by chemical-physical parameters affecting cathodic processes (oxygen discharge, hydrogen evolution and calcareous deposit precipitation). In shallow seawater, these parameters are influenced by sunlight photoperiod and photosynthetic activity. The results presented here represent the first step in studies dedicated to cathodic protection in shallow photic seawater. This paper reports on carbon steel protected at -850 mV vs. Ag/AgCl (oxygen limiting current regime) in the presence of sunlight radiation but in the absence of biological and photosynthetic activity, the role of which deserves future research. Comparison of results obtained by exposing electrochemical cells to daylight cycles in both biologically inactivated natural seawater and in NaCl 3.5 wt.% solutions showed that sunlight affects current densities and that calcareous deposit interfere with light-currents effects. Sunlight radiation and induced heating of the solution have been separated, highlighting results not otherwise obvious: (1) observed current waves concomitant with sunlight radiation depend fundamentally on solar radiation, (2) solar radiation can determine current enhancements from early to late phases of aragonite crystal growth, (3) a three-day-old CaCO{sub 3} layer reduces but does not eliminate the amplitude of the current waves. Theoretical calculations for oxygen limiting currents and additional field tests showed that sunlight, rather than bulk solution heating, is the main cause of daily current enhancements. This was confirmed by polarizations performed at -850 and -1000 mV vs. Ag/AgCl (constant bulk temperature), during which the electrode was irradiated with artificial lighting. This test also confirmed O{sub 2} discharge to be the cathodic process involved. A mechanism of radiation conversion to heat in the oxygen diffusion layer region is proposed.

  10. Why We Need More Nature at Work: Effects of Natural Elements and Sunlight on Employee Mental Health and Work Attitudes.

    Science.gov (United States)

    An, Mihyang; Colarelli, Stephen M; O'Brien, Kimberly; Boyajian, Melanie E

    2016-01-01

    This study investigated the effects of natural elements and direct and indirect sunlight exposure on employee mental health and work attitudes. We recruited participants via an online panel from the United States and India, and analyzed data from 444 employees. Natural elements and sunlight exposure related positively to job satisfaction and organizational commitment, and negatively to depressed mood and anxiety. Direct sunlight was a dominant predictor of anxiety; indirect sunlight was a dominant predictor of depressed mood, job satisfaction, and organizational commitment. Natural elements buffered the relationship between role stressors and job satisfaction, depressed mood, and anxiety. We also found that depressed mood partially mediated the relationship between natural elements and job satisfaction. We discuss scientific and policy implications of these findings.

  11. Why We Need More Nature at Work: Effects of Natural Elements and Sunlight on Employee Mental Health and Work Attitudes

    Science.gov (United States)

    An, Mihyang; Colarelli, Stephen M.; O'Brien, Kimberly; Boyajian, Melanie E.

    2016-01-01

    This study investigated the effects of natural elements and direct and indirect sunlight exposure on employee mental health and work attitudes. We recruited participants via an online panel from the United States and India, and analyzed data from 444 employees. Natural elements and sunlight exposure related positively to job satisfaction and organizational commitment, and negatively to depressed mood and anxiety. Direct sunlight was a dominant predictor of anxiety; indirect sunlight was a dominant predictor of depressed mood, job satisfaction, and organizational commitment. Natural elements buffered the relationship between role stressors and job satisfaction, depressed mood, and anxiety. We also found that depressed mood partially mediated the relationship between natural elements and job satisfaction. We discuss scientific and policy implications of these findings. PMID:27214041

  12. 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.

  13. Natural sunlight shapes crude oil-degradingbacterial communities in northern Gulf of Mexico surface waters

    Directory of Open Access Journals (Sweden)

    Hernando P Bacosa

    2015-12-01

    Full Text Available Following the Deepwater Horizon (DWH spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 d under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

  14. Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.

    Science.gov (United States)

    Bacosa, Hernando P; Liu, Zhanfei; Erdner, Deana L

    2015-01-01

    Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

  15. Bleaching of the thermoluminescence of feldspars by sunlight

    International Nuclear Information System (INIS)

    Robertson, G.B.; Prescott, J.R.; Hutton, J.T.

    1991-01-01

    Feldspars are an important component of materials used for thermoluminescence (TL) and photoluminescence (PL) dating of sediments; and successful dating implies a knowledge of the degree of re-setting by exposure to sunlight of the stored luminescence energy. We have studied the bleaching by full sunlight of the TL of six alkali feldspars of representative composition and of one oligoclase. The high potassium and high sodium feldspars are the brightest, and are also the least easily bleached, whereas those of intermediate (K-Na) composition bleach quickly. On a time scale of upwards of 16 h, all samples would have bleached enough for them to be useful for TL dating. A search was made for individual glow curve peaks that bleach particularly quickly (and are thus similar to the well-known 325 o C peak used in the TL dating of quartz). In the samples studied, there was only one glow curve peak that was selectively susceptible to bleaching: the 280 o C peak in oligoclase. (author)

  16. Vitamin D, Sunlight and Prostate Cancer Risk

    Directory of Open Access Journals (Sweden)

    Krishna Vanaja Donkena

    2011-01-01

    Full Text Available Prostate cancer is the second common cancer in men worldwide. The prevention of prostate cancer remains a challenge to researchers and clinicians. Here, we review the relationship of vitamin D and sunlight to prostate cancer risk. Ultraviolet radiation of the sunlight is the main stimulator for vitamin D production in humans. Vitamin D's antiprostate cancer activities may be involved in the actions through the pathways mediated by vitamin D metabolites, vitamin D metabolizing enzymes, vitamin D receptor (VDR, and VDR-regulated genes. Although laboratory studies including the use of animal models have shown that vitamin D has antiprostate cancer properties, whether it can effectively prevent the development and/or progression of prostate cancer in humans remains to be inconclusive and an intensively studied subject. This review will provide up-to-date information regarding the recent outcomes of laboratory and epidemiology studies on the effects of vitamin D on prostate cancer prevention.

  17. Degadation of semiconducting polymers by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manceau, Matthieu; Petersen, Martin Helgesen

    2011-01-01

    infra-red spectra of MEH-PPV degraded at 1 sun intensity and at high solar concentration only showed minor deviations in degradation mechanisms. The acceleration factor was found to vary linearly with the solar concentration. Finally, a comparison of the degradation rates at 1 sun and 100 suns...... was carried out in a materials study employing five different conjugated polymers relevant to polymer solar cells for which acceleration factors in the range 19–55 were obtained.......A lens based sunlight concentration setup was used to accelerate the degradation of semiconducting polymers. Sunlight was collected outdoor and focused into an optical fiber bundle allowing for indoor experimental work. Photo-degradation of several polymers was studied by UV–vis absorbance...

  18. Convective heat exposure from large fires to the final filters of ventilation systems

    International Nuclear Information System (INIS)

    Alvares, N.J.

    1979-01-01

    The Fire Science Group of the Hazards Control Department, Lawrence Livermore Laboratory has been asked to design a probable fire scenario for a fuel-pellet fabrication facility. This model was used to estimate the potential for thermal damage to the final HEPA filters. These filters would not experience direct fire exposure because they are the last component of the ventilation system before the exhaust air pumps. However, they would be exposed to hot air and fire gases that are drawn into the ventilation system. Because fire is one of the few occurrences that can defeat the containment integrity of facilities where radioactive materials are stored and processed, the fire scenarios must be defined to ensure that containment systems are adequate to meet the threat of such events. Fire-growth calculations are based on the measured fuel load of materials within the fabrication enclosure and on semi-empirical fire-spread models. It is assumed that the fire never becomes ventilation controlled. The temperature rise of ceiling gases and heat transfer from ventilation ducting are calculated using accepted empirical relationships, and the analysis shows that even under the most severe exposure conditions, heat transfer from the duct reduces the fire gas temperatures to levels that would not hamper filter function

  19. Colour Counts: Sunlight and Skin Type as Drivers of Vitamin D Deficiency at UK Latitudes.

    Science.gov (United States)

    Webb, Ann R; Kazantzidis, Andreas; Kift, Richard C; Farrar, Mark D; Wilkinson, Jack; Rhodes, Lesley E

    2018-04-07

    Sunlight exposure, with resulting cutaneous synthesis, is a major source of vitamin D for many, while dietary intake is low in modern diets. The constitutive pigment in skin determines skin type, observed as white, brown, or black skin. The melanin pigment absorbs ultraviolet radiation (UVR) and protects underlying skin from damage caused by UVR. It also reduces the UVR available for vitamin D synthesis in the skin. It has been shown that the white-skinned population of the UK are able to meet their vitamin D needs with short, daily lunchtime exposures to sunlight. We have followed the same methodology, based on a 10-year UK all-weather UVR climatology, observation (sun exposure, diet, vitamin D status), and UVR intervention studies with Fitzpatrick skin type V (brown) adults, to determine whether sunlight at UK latitudes could provide an adequate source of vitamin D for this section of the population. Results show that to meet vitamin D requirements, skin type V individuals in the UK need ~25 min daily sunlight at lunchtime, from March to September. This makes several assumptions, including that forearms and lower legs are exposed June-August; only exposing hands and face at this time is inadequate. For practical and cultural reasons, enhanced oral intake of vitamin D should be considered for this population.

  20. Colour Counts: Sunlight and Skin Type as Drivers of Vitamin D Deficiency at UK Latitudes

    Directory of Open Access Journals (Sweden)

    Ann R. Webb

    2018-04-01

    Full Text Available Sunlight exposure, with resulting cutaneous synthesis, is a major source of vitamin D for many, while dietary intake is low in modern diets. The constitutive pigment in skin determines skin type, observed as white, brown, or black skin. The melanin pigment absorbs ultraviolet radiation (UVR and protects underlying skin from damage caused by UVR. It also reduces the UVR available for vitamin D synthesis in the skin. It has been shown that the white-skinned population of the UK are able to meet their vitamin D needs with short, daily lunchtime exposures to sunlight. We have followed the same methodology, based on a 10-year UK all-weather UVR climatology, observation (sun exposure, diet, vitamin D status, and UVR intervention studies with Fitzpatrick skin type V (brown adults, to determine whether sunlight at UK latitudes could provide an adequate source of vitamin D for this section of the population. Results show that to meet vitamin D requirements, skin type V individuals in the UK need ~25 min daily sunlight at lunchtime, from March to September. This makes several assumptions, including that forearms and lower legs are exposed June–August; only exposing hands and face at this time is inadequate. For practical and cultural reasons, enhanced oral intake of vitamin D should be considered for this population.

  1. 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

    Extreme temperatures and exposure to agricultural pesticides are becoming more frequent and intense under global change. Their combination may be especially problematic when animals suffer food limitation. We exposed Coenagrion puella damselfly larvae to a simulated heat wave combined with food...... limitation and subsequently to a widespread agricultural pesticide (chlorpyrifos) in an indoor laboratory experiment designed to obtain mechanistic insights in the direct effects of these stressors in isolation and when combined. The heat wave reduced immune function (activity of phenoloxidase, PO...... 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...

  2. Sunlight stability and rain-fastness of formulations of Baculovirus heliothis

    International Nuclear Information System (INIS)

    Ignoffo, C.M.; Garcia, C.; Saathoff, S.G.

    1997-01-01

    Sunlight-Ultraviolet, with an activity spectrum from 290 to 400 nm, is the most destructive factor affecting the persistence of baculoviruses. Benzopurpurin (a disazo dye) and carbon provided the best protection when polyhedral inclusion bodies (PIB) of Baculovirus heliothis were exposed to an artificial spectrum simulating sunlight-UV (UV). Greater than 75% of the original PIB activity was still present after 48 h of sunlight-UV. When sprayed on soybeans and exposed to natural sunlight, only formulations with carbon provided significant protection of PIB. The half-life of formulations were PIB-only 4.9 +/- 1.4 h (mean +/- SE), PIB + polymer (pyrrolidone-based sticker) 3.3 +/- 0.6 h, PIB + polymer + benzopurpurin 3.4 +/- 0.7 h, and PIB + polymer + carbon 27.7 +/- 5.2 h. PIB of B. heliothis tenaciously adhere to soybean, Glycine max (L.) Merrill, leaflets after spraying and drying. Less than 6% of the PIB activity of nonformulated PIB was lost after a drenching, simulated rainfall. More than 97% of the original PIB activity of carbon formulations was still present on soybean leaflets after 10 h of exposure to sunlight-UV. In contrast, 20% was present for formulations without carbon

  3. Heat treatment on keruing and light red meranti: The effect of heat exposure at different levels of temperature on bending strength properties

    Science.gov (United States)

    Noh, Nur Ilya Farhana Md; Ahmad, Zakiah

    2017-11-01

    Heat treatment on timbers is a process of applying heat to modify and equip the timbers with new improvised characteristics. It is environmental friendly compared to the common practice of treating timber by chemical preservatives. Malaysian hardwood timbers namely Keruing and Light Red Meranti which are in green condition were heat treated at temperature 150°C, 170°C, 190°C and 210°C, in a specially designed electronic furnace within one hour duration. The objectives were to determine the effect of heat treatment on bending strength properties of heat treated timbers in terms of Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) and to examine the significance changes at each temperature level. Untreated samples for each species were used as a control sample. The results indicated that the bending strength properties for both species of timbers were affected by the heat exposure. Both MOE and MOR values for heat treated Keruing were increased when subjected to the temperature levels at 150°C, 170°C and 190°C except at 210°C. Heat treated Light Red Meranti shows the same pattern of increment on its MOE and MOR values after exposure to heat at three temperature levels applied and the values dropped at 210°C. However, for both of species, even though there were decrement occurred at 210°C, the value is still higher compared to the control sample. The increments of MOE and MOR values are an indicator that heat treatment had successfully improvised the bending strength properties of these two species of hardwood timber.

  4. [Expression of heat shock protein 70 and its mRNA in career exposure to manganese].

    Science.gov (United States)

    Chen, Wenwen; Shao, Hua; Chi, Mingfeng; Zhang, Zhihu; Shan, Yongle; Zou, Wei

    2015-10-01

    To analyze the expression levels of heat shock protein70 (HSPs70) and HSPs70 mRNA in different exposure to manganese, and research the neuroprotective effect on the career exposure to manganese. From 2008 to 2009, with cross-sectional study design, and in a locomotive and rolling stock works, by stratified random sampling method, the exposed sample consisted of 180 welders from different welding shops and 100 unexposed in the last three years, non-welder controls with age-matched workers of similar socioeconomic status from the same industry. The control workers had not been exposed to neurotoxic chemicals. The mRNA expressions of four different metabolic enzyme were detected by SYBR Green I quantitative real-time polymerase chain reaction. The expression levels of the two enzymes mRNA in different exposure to manganese were analyzed. The expressions of HSPs70 were detected by Western blot. The concentration of air manganese was determined by GFAAS. The average concentration of 8 h time (8h-TWA) was used to express the level of individual exposure to manganese, according to the air manganese workplace occupational exposure limit (8h-TWA=0.15 mg/m3), the exposed group is divided into high exposed group (>0.15 mg/m3) and low exposure group (<0.15 mg/m3). The individuals exposed to manganese dose of exposed group ((0.25±0.31) mg/m3) was higher than the control group ((0.06±0.02) mg/m3) (t=6.15, P=0.001); individuals exposed to manganese dose of high exposure group for (0.42±0.34) mg/m3, which was higher than low exposure group (0.09±0.07) mg/m3 (t=9.80, P=0.001). HSPs70 mRNA and protein of exposure group (5.65±0.21, 3.26±0.15) were higher than the reference group (0.41±0.03, 1.32±0.12) (t=18.91, t=8.68, P=0.001). HSP70 mRNA and protein of high exposure group (6.48±0.37, 3.67±0.26) were higher than the low exposure group (5.15±0.23, 3.02±0.19) (t=3.24, t=2.01, P=0.003, P=0.043). The expression of peripheral blood lymphocytes HSPs70 level and HSPs70 m

  5. Persistence of Bacteroides ovatus under simulated sunlight irradiation

    KAUST Repository

    Dong, Shengkun

    2014-07-04

    Background: Bacteroides ovatus, a member of the genus Bacteroides, is considered for use in molecular-based methods as a general fecal indicator. However, knowledge on its fate and persistence after a fecal contamination event remains limited. In this study, the persistence of B. ovatus was evaluated under simulated sunlight exposure and in conditions similar to freshwater and seawater. By combining propidium monoazide (PMA) treatment and quantitative polymerase chain reaction (qPCR) detection, the decay rates of B. ovatus were determined in the presence and absence of exogenous photosensitizers and in salinity up to 39.5 parts per thousand at 27°C. Results: UVB was found to be important for B. ovatus decay, averaging a 4 log10 of decay over 6 h of exposure without the presence of extracellular photosensitizers. The addition of NaNO2, an exogenous sensitizer producing hydroxyl radicals, did not significantly change the decay rate of B. ovatus in both low and high salinity water, while the exogenous sensitizer algae organic matter (AOM) slowed down the decay of B. ovatus in low salinity water. At seawater salinity, the decay rate of B. ovatus was slower than that in low salinity water, except when both NaNO2 and AOM were present. Conclusion: The results of laboratory experiments suggest that if B. ovatus is released into either freshwater or seawater environment in the evening, 50% of it may be intact by the next morning; if it is released at noon, only 50% may be intact after a mere 5 min of full spectrum irradiation on a clear day. This study provides a mechanistic understanding to some of the important environmental relevant factors that influenced the inactivation kinetics of B. ovatus in the presence of sunlight irradiation, and would facilitate the use of B. ovatus to indicate the occurrence of fecal contamination.

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

    Science.gov (United States)

    Sett, Moumita; Sahu, Subhashis

    2014-01-01

    Background Manual brick-manufacturing units in India engage a large number of female workers on a daily-wage basis for a period of 8 months per year. There are two groups of female workers in the brickfields: the brick molders and the brick carriers. These brickfields are mostly unorganized, and the workers are exposed to extreme conditions such as very high seasonal heat. The present trend of increasing temperatures, as a result of global warming and climate change, will put an additional burden on them. Objective This study aims to evaluate the effect of workplace heat exposure on the well-being, physiological load, and productivity of female brickfield workers in India. Design A questionnaire study (n=120), environmental temperature, and weekly work productivity analyses were evaluated for 8 months in the brickfields. Cardiac strain and walking speed (subset, n=40) were also studied and compared in hotter and colder days amongst the female brickfield workers. Results The subjects experience summer for about 5 months with additional heat stress radiating from the brick kiln. The weekly productivity data show a linear decline in productivity with increased maximum air temperature above 34.9°C. The cardiac parameters (peak heart rate (HRp), net cardiac cost (NCC), relative cardiac cost (RCC), and recovery heart rates) were significantly higher on hotter days (Wet Bulb Globe Temperature (WBGTout) index: 26.9°C to 30.74°C) than on cooler days (WBGTout index: 16.12°C to 19.37°C) for the brick molders; however, this is not the case for the brick carriers. As the brick carriers adapt to hotter days by decreasing their walking speed, their productivity decreases. Conclusion 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

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

    Science.gov (United States)

    Sett, Moumita; Sahu, Subhashis

    2014-01-01

    Manual brick-manufacturing units in India engage a large number of female workers on a daily-wage basis for a period of 8 months per year. There are two groups of female workers in the brickfields: the brick molders and the brick carriers. These brickfields are mostly unorganized, and the workers are exposed to extreme conditions such as very high seasonal heat. The present trend of increasing temperatures, as a result of global warming and climate change, will put an additional burden on them. This study aims to evaluate the effect of workplace heat exposure on the well-being, physiological load, and productivity of female brickfield workers in India. A questionnaire study (n=120), environmental temperature, and weekly work productivity analyses were evaluated for 8 months in the brickfields. Cardiac strain and walking speed (subset, n=40) were also studied and compared in hotter and colder days amongst the female brickfield workers. The subjects experience summer for about 5 months with additional heat stress radiating from the brick kiln. The weekly productivity data show a linear decline in productivity with increased maximum air temperature above 34.9°C. The cardiac parameters (peak heart rate (HRp), net cardiac cost (NCC), relative cardiac cost (RCC), and recovery heart rates) were significantly higher on hotter days (Wet Bulb Globe Temperature (WBGTout) index: 26.9°C to 30.74°C) than on cooler days (WBGTout index: 16.12°C to 19.37°C) for the brick molders; however, this is not the case for the brick carriers. As the brick carriers adapt to hotter days by decreasing their walking speed, their productivity decreases. 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

  8. Sunlight persistence and rainfastness of spray-dried formulations of baculovirus isolated from Anagrapha falcifera (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Tamez-Guerra, P; McGuire, M R; Behle, R W; Hamm, J J; Sumner, H R; Shasha, B S

    2000-04-01

    Nuclear polyhedrosis viruses such as the one isolated from the celery looper, Anagrapha falcifera (Kirby) (AfMNPV), have the potential to be successful bioinsecticides if improved formulations can prevent rapid loss of insecticidal activity from environmental conditions such as sunlight and rainfall. We tested 16 spray-dried formulations of AfMNPV to determine the effect of different ingredients (e.g., lignin, corn flour, and so on) on insecticidal activity after simulated rain and simulated sunlight (at Peoria, IL) and natural sunlight exposures (at Tifton, GA). The most effective formulation contained pregelatinized corn flour and potassium lignate, which retained more than half of its original activity after 5 cm of simulated rain, and almost full activity after 8 h of simulated sunlight. In Georgia, formulations made with and without lignin were compared for persistence of insecticidal activity when exposed to natural sunlight. In addition, the effect of fluorescent brighteners as formulation components and spray tank additives was tested. Results showed that the formulations with lignin had more insecticidal activity remaining after sunlight exposure than formulations without lignin. The inclusion of brighteners in the formulation did not improve initial activity or virus persistence. However, a 1% tank mix significantly enhanced activity and improved persistence. Scanning electron micrographs revealed discreet particles, and transmission electron micrographs showed virus embedded within microgranules. Results demonstrated that formulations made with natural ingredients could improve persistence of virus-based biopesticides.

  9. 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.

  10. Sauna exposure immediately prior to short-term heat acclimation accelerates phenotypic adaptation in females.

    Science.gov (United States)

    Mee, Jessica A; Peters, Sophie; Doust, Jonathan H; Maxwell, Neil S

    2018-02-01

    Investigate whether a sauna exposure prior to short-term heat acclimation (HA) accelerates phenotypic adaptation in females. Randomised, repeated measures, cross-over trial. Nine females performed two 5-d HA interventions (controlled hyperthermia T re ≥38.5°C), separated by 7-wk, during the follicular phase of the menstrual cycle confirmed by plasma concentrations of 17-β estradiol and progesterone. Prior to each 90-min HA session participants sat for 20-min in either a temperate environment (20°C, 40% RH; HA temp ) wearing shorts and sports bra or a hot environment (50°C, 30% RH) wearing a sauna suit to replicate sauna conditions (HA sauna ). Participants performed a running heat tolerance test (RHTT) 24-h pre and 24-h post HA. Mean heart rate (HR) (85±4 vs. 68±5 bpm, p≤0.001), sweat rate (0.4±0.2 vs. 0.0±0.0Lh -1 , p≤0.001), and thermal sensation (6±0 vs. 5±1, p=0.050) were higher during the sauna compared to temperate exposure. Resting rectal temperature (T re ) (-0.28±0.16°C), peak T re (-0.42±0.22°C), resting HR (-10±4 bpm), peak HR (-12±7 bpm), T re at sweating onset (-0.29±0.17°C) (p≤0.001), thermal sensation (-0.5±0.5; p=0.002), and perceived exertion (-3±2; p≤0.001) reduced during the RHTT, following HA sauna ; but not HA temp . Plasma volume expansion was greater following HA sauna (HA sauna , 9±7%; HA temp , 1±5%; p=0.013). Sweat rate (p≤0.001) increased and sweat NaCl (p=0.006) reduced during the RHTT following HA sauna and HA temp . This novel strategy initiated HA with an attenuation of thermoregulatory, cardiovascular, and perceptual strain in females due to a measurably greater strain in the sauna compared to temperate exposure when adopted prior to STHA. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. Effect of storage temperature and sunlight exposure on the ...

    African Journals Online (AJOL)

    Physicochemical properties (pH, Electrical conductivity, Total dissolved salt, Cl- , F- , NO3- ,SO4-2, NH4+ and Chemical oxygen demand) of Sixteen brands bottled water in Kurdistan region-Iraq were analyzed using standard methods. The physicochemical properties of the bottled water measured in this work compared with ...

  12. Life-threatening motor vehicle crashes in bright sunlight

    OpenAIRE

    Redelmeier, Donald A.; Raza, Sheharyar

    2017-01-01

    Abstract Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estim...

  13. Traceable calibration of photovoltaic reference cells using natural sunlight

    Science.gov (United States)

    Müllejans, H.; Zaaiman, W.; Pavanello, D.; Dunlop, E. D.

    2018-02-01

    At the European Solar Test Installation (ESTI) photovoltaic (PV) reference cells are calibrated traceably to SI units via the World Radiometric Reference (WRR) using natural sunlight. The Direct Sunlight Method (DSM) is described in detail and the latest measurement results and an updated uncertainty budget are reported. These PV reference cells then provide a practical means for measuring the irradiance of natural or simulated sunlight during the calibration of other PV devices.

  14. 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...

  15. 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.

  16. Genotoxic action of sunlight upon Bacillus subtilis spores

    International Nuclear Information System (INIS)

    Munakata, Nobuo

    1989-01-01

    Samples of Bacillus subtilis spores dried on membrane filter were exposed to natural sunlight from solar-noon time at Tokyo. The survival and mutation induction of wild-type (UVR) and repair-deficient (UVS) spores were determined on 66 occasions since 1979. Two of the values were considered to be useful in monitoring solar UV intensity; the inverse of the time (in minutes) of exposure to kill 63% of the UVS spores ('sporocidal index') and the induced mutation frequency at 60 minutes of exposure of the UVR spores ('mutagenic index'). Both values were varied greatly due to time of a year, weather and other conditions. Estimates of year-round changes under clear skies were obtained by connecting the maximum values attained in these years. In these curves, there are more than 7-fold differences in the genotoxicity between winter and summer months, with major increases observed in early spring and decreases through autumn. Using a series of UV cut-off filters, the wavelengths most effective for the sporocidal actions were estimated to be in the range of 308 - 325 nm, shorter wavelengths being effective when the genotoxicity was higher. Sunburn meter of Robertson-Berger type seems to respond to slightly longer wavelength components of the solar spectrum. However, a reasonable correlation was obtained between the reading of the meter and the sporocidal index. (author)

  17. Transfer shuttle for vitrified residue canisters control of risks associated with external exposure and heat release

    Energy Technology Data Exchange (ETDEWEB)

    BIndel, L.; Gamess, A.; Lejeune, E.; Cellier, P.; Maillard, A. [SGN Reseau Eurisys, 78 - Saint Quentin (France)

    1998-07-01

    In the La Hague COGEMA's plant area, nuclear residue isolated by reprocessing are transported by means of specific transfer shuttles between the different processing and/or conditioning facilities and the storage ones. These shuttles are designed by reference to the applicable dose equivalent rate (DER) limits for transport on the site and the thermal behavior limitations of certain mechanical components which guarantee the containment of the transported waste. This paper describes and example of a study conducted on a transfer shuttle for vitrified residue canisters. Concerning the control of risks associated with external exposure and with heat releases, these were handled by the 'Shielding-Criticality-Dispersion' and 'process Modelling and Simulation' Sections of the Technical Division of SGN. The dose profiles around the shuttle, as a function of the shielding heterogeneities and possible radiation leakage, as well as the thermal fields within the shuttle, were calculated using 3D models. These design studies ultimately helped to select and validate the optimal solutions. (authors)

  18. Does attenuated skin blood flow lower sweat rate and the critical environmental limit for heat balance during severe heat exposure?

    Science.gov (United States)

    Cramer, Matthew N; Gagnon, Daniel; Crandall, Craig G; Jay, Ollie

    2017-02-01

    What is the central question of this study? Does attenuated skin blood flow diminish sweating and reduce the critical environmental limit for heat balance, which indicates maximal heat loss potential, during severe heat stress? What is the main finding and its importance? Isosmotic hypovolaemia attenuated skin blood flow by ∼20% but did not result in different sweating rates, mean skin temperatures or critical environmental limits for heat balance compared with control and volume-infusion treatments, suggesting that the lower levels of skin blood flow commonly observed in aged and diseased populations may not diminish maximal whole-body heat dissipation. Attenuated skin blood flow (SkBF) is often assumed to impair core temperature (T c ) regulation. Profound pharmacologically induced reductions in SkBF (∼85%) lead to impaired sweating, but whether the smaller attenuations in SkBF (∼20%) more often associated with ageing and certain diseases lead to decrements in sweating and maximal heat loss potential is unknown. Seven healthy men (28 ± 4 years old) completed a 30 min equilibration period at 41°C and a vapour pressure (P a ) of 2.57 kPa followed by incremental steps in P a of 0.17 kPa every 6 min to 5.95 kPa. Differences in heat loss potential were assessed by identifying the critical vapour pressure (P crit ) at which an upward inflection in T c occurred. The following three separate treatments elicited changes in plasma volume to achieve three distinct levels of SkBF: control (CON); diuretic-induced isosmotic dehydration to lower SkBF (DEH); and continuous saline infusion to maintain SkBF (SAL). The T c , mean skin temperature (T sk ), heart rate, mean laser-Doppler flux (forearm and thigh; LDF mean ), mean local sweat rate (forearm and thigh; LSR mean ) and metabolic rate were measured. In DEH, a 14.2 ± 5.7% lower plasma volume resulted in a ∼20% lower LDF mean in perfusion units (PU) (DEH, 139 ± 23 PU; CON, 176 ± 22 PU; and SAL

  19. Fate of kelthane residues on apple pomace exposed to drying in the dark, sunlight, and ultraviolet light irradiation

    International Nuclear Information System (INIS)

    Archer, T.E.; Toscano, R.A.

    1972-01-01

    The present investigations were undertaken to determine the fate of Kelthane residues intentionally applied to apples under controlled laboratory conditions and the reduction of these residues in the pomace by exposure to drying in the dark, in sunlight, and ultraviolet light irradiation

  20. 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.

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

    International Nuclear Information System (INIS)

    Raj, Phani K.

    2008-01-01

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

  2. Impact of desiccation and heat exposure stress on Salmonella tolerance to acidic conditions.

    Science.gov (United States)

    Richardson, Kurt E; Cox, Nelson A; Cosby, Douglas E; Berrang, Mark E

    2018-02-01

    In a recent study, the pH of commonly used Salmonella pre-enrichment media became acidic (pH 4.0 to 5.0) when feed or feed ingredients were incubated for 24 h. Acidic conditions have been reported to injure or kill Salmonella. In this study, cultures of four known feed isolates (S. montevideo, S. senftenberg, S. tennessee, and S. schwarzengrund) and four important processing plant isolates (S. typhimurium, S. enteritidis, S. infantis, and S. heidelberg) were grown on meat and bone meal and later subjected to desiccation and heat exposure to stress the microorganism. The impact of stress on the isolates ability to survive in acidic conditions ranging from pH 4.0 to 7.0 was compared to the non-stressed isolate. Cell injury was determined on xylose lysine tergitol 4 (XLT4) and cell death determined on nutrient agar (NA). When measured by cell death in non-stressed Salmonella, S. typhimurium was the most acid tolerant and S. heidelberg was the most acid sensitive whereas in stressed Salmonella, S. senftenberg was the most acid tolerant and S. tennessee was the most acid sensitive. The pH required to cause cell injury varied among isolates. With some isolates, the pH required for 50% cell death and 50% cell injury was similar. In other isolates, cell injury occurred at a more neutral pH. These findings suggest that the pH of pre-enrichment media may influence the recovery and bias the serotype of Salmonella recovered from feed during pre-enrichment.

  3. The epidemiology of occupational heat exposure in the United States: a review of the literature and assessment of research needs in a changing climate

    Science.gov (United States)

    Gubernot, Diane M.; Anderson, G. Brooke; Hunting, Katherine L.

    2014-10-01

    In recent years, the United States has experienced record-breaking summer heat. Climate change models forecast increasing US temperatures and more frequent heat wave events in the coming years. Exposure to environmental heat is a significant, but overlooked, workplace hazard that has not been well-characterized or studied. The working population is diverse; job function, age, fitness level, and risk factors to heat-related illnesses vary. Yet few studies have examined or characterized the incidence of occupational heat-related morbidity and mortality. There are no federal regulatory standards to protect workers from environmental heat exposure. With climate change as a driver for adaptation and prevention of heat disorders, crafting policy to characterize and prevent occupational heat stress for both indoor and outdoor workers is increasingly sensible, practical, and imperative.

  4. Photolytic debromination pathway of polybrominated diphenyl ethers in hexane by sunlight

    International Nuclear Information System (INIS)

    Wei, Hua; Zou, Yonghong; Li, An; Christensen, Erik R.; Rockne, Karl J.

    2013-01-01

    The objective of this work is to identify the photolytic debromination pathways of polybrominated diphenyl ethers (PBDEs). Thirteen PBDEs (BDEs 209, 208, 207, 206, 196, 183, 154, 153, 100, 99, 85, 47 and 28) in hexane were individually exposed to sunlight for up to 64 h. A total of 180 PBDEs were screened and 74 BDE debromination products were detected. The disappearance rate constant increased exponentially with increasing number of bromines. While no evident difference in debromination preference among ortho, meta and para bromines was found for heavier congeners, the vulnerability rank order was meta ≥ ortho > para for the lighter congeners (≤8 Br). The total molar mass of PBDEs continuously decreased during sunlight exposure, indicating PBDEs were transformed to non-PBDE compounds. A stochastic least squares debromination pathway model was developed to simulate the reactions and determine the yields to extend the results beyond the experimental observations. -- Highlights: ► 74 PBDEs are identified as the products of debromination via photolysis. ► Debromination is more likely at meta than para positions for PBDEs with ≤8 bromines. ► The stochastic least squares model results agree with and expand the experimental observations. ► Mass imbalance indicates a significant loss of PBDE mass during sunlight exposure. -- The PBDE debromination products and pathways identified in this work will assist in future studies on their environmental fate

  5. Sunlight Effects on Immune System: Is There Something Else in addition to UV-Induced Immunosuppression?

    Directory of Open Access Journals (Sweden)

    D. H. González Maglio

    2016-01-01

    Full Text Available Sunlight, composed of different types of radiation, including ultraviolet wavelengths, is an essential source of light and warmth for life on earth but has strong negative effects on human health, such as promoting the malignant transformation of skin cells and suppressing the ability of the human immune system to efficiently detect and attack malignant cells. UV-induced immunosuppression has been extensively studied since it was first described by Dr. Kripke and Dr. Fisher in the late 1970s. However, skin exposure to sunlight has not only this and other unfavorable effects, for example, mutagenesis and carcinogenesis, but also a positive one: the induction of Vitamin D synthesis, which performs several roles within the immune system in addition to favoring bone homeostasis. The impact of low levels of UV exposure on the immune system has not been fully reported yet, but it bears interesting differences with the suppressive effect of high levels of UV radiation, as shown by some recent studies. The aim of this article is to put some ideas in perspective and pose some questions within the field of photoimmunology based on established and new information, which may lead to new experimental approaches and, eventually, to a better understanding of the effects of sunlight on the human immune system.

  6. Sunlight Effects on Immune System: Is There Something Else in addition to UV-Induced Immunosuppression?

    Science.gov (United States)

    Paz, M. L.; Leoni, J.

    2016-01-01

    Sunlight, composed of different types of radiation, including ultraviolet wavelengths, is an essential source of light and warmth for life on earth but has strong negative effects on human health, such as promoting the malignant transformation of skin cells and suppressing the ability of the human immune system to efficiently detect and attack malignant cells. UV-induced immunosuppression has been extensively studied since it was first described by Dr. Kripke and Dr. Fisher in the late 1970s. However, skin exposure to sunlight has not only this and other unfavorable effects, for example, mutagenesis and carcinogenesis, but also a positive one: the induction of Vitamin D synthesis, which performs several roles within the immune system in addition to favoring bone homeostasis. The impact of low levels of UV exposure on the immune system has not been fully reported yet, but it bears interesting differences with the suppressive effect of high levels of UV radiation, as shown by some recent studies. The aim of this article is to put some ideas in perspective and pose some questions within the field of photoimmunology based on established and new information, which may lead to new experimental approaches and, eventually, to a better understanding of the effects of sunlight on the human immune system. PMID:28070504

  7. Effects of UV, sunlight and X-ray radiation on quiescent human cells in culture

    International Nuclear Information System (INIS)

    Kantor, G.J.

    1986-01-01

    Nondividing human diploid fibroblasts (HDF) in culture have been used to study the effect on cell lethality of ultraviolet light, natural sunlight and X-rays. A lethal effect is defined as cellular degeneration, loss from the culture and inability to exclude vital strains. Far- and mid-UV have a readily observable lethal effect (cell loss), with DNA and DNA damage as the critical target and critical damage respectively. In part, natural sunlight kills cells by a similar mechanism but has an additional lethal effect at longer exposure times. This additional effect is expressed by the retention of the dead cells in culture, in contrast to the UV-induced promotion of cell degeneration and loss. Relatively large doses of X-rays that destroy proliferative capacity, have no detectable lethal effect on the maintenance of non-dividing cells. The biological response of nondividing HDF to radiations from different parts of the electromagnetic spectrum is dissimilar. (author)

  8. 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

  9. Temporal Stability of the Microbial Community in Sewage-Polluted Seawater Exposed to Natural Sunlight Cycles and Marine Microbiota

    Science.gov (United States)

    Sassoubre, Lauren M.; Yamahara, Kevan M.

    2015-01-01

    Billions of gallons of untreated wastewater enter the coastal ocean each year. Once sewage microorganisms are in the marine environment, they are exposed to environmental stressors, such as sunlight and predation. Previous research has investigated the fate of individual sewage microorganisms in seawater but not the entire sewage microbial community. The present study used next-generation sequencing (NGS) to examine how the microbial community in sewage-impacted seawater changes over 48 h when exposed to natural sunlight cycles and marine microbiota. We compared the results from microcosms composed of unfiltered seawater (containing naturally occurring marine microbiota) and filtered seawater (containing no marine microbiota) to investigate the effect of marine microbiota. We also compared the results from microcosms that were exposed to natural sunlight cycles with those from microcosms kept in the dark to investigate the effect of sunlight. The microbial community composition and the relative abundance of operational taxonomic units (OTUs) changed over 48 h in all microcosms. Exposure to sunlight had a significant effect on both community composition and OTU abundance. The effect of marine microbiota, however, was minimal. The proportion of sewage-derived microorganisms present in the microcosms decreased rapidly within 48 h, and the decrease was the most pronounced in the presence of both sunlight and marine microbiota, where the proportion decreased from 85% to 3% of the total microbial community. The results from this study demonstrate the strong effect that sunlight has on microbial community composition, as measured by NGS, and the importance of considering temporal effects in future applications of NGS to identify microbial pollution sources. PMID:25576619

  10. Heat Stress

    Science.gov (United States)

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

  11. Nature sunlight bleaching of Ti center ESR signal in quartz

    International Nuclear Information System (INIS)

    Yin Gongming; Liu Chunru; Li Jianping; Fang Jiahu; Gao Lu; Lin Min

    2009-01-01

    Quartz grains were extracted from granite. Bleaching was carried out in four different area chosen for their different altitudes (Beijing, Yinchuan, Germu, Lhasa), in order to observe their behavior under different intensities of the UV (Ultra violet) component of sunlight. The result of our experiments indicate that the Ti center signal is totally bleachable by the natural sunlight and show that the Ti center signal was reduced to zero after about 128 h in Beijing and after 56 h for Lhasa. We can speculate that different intensity of the UV component of sunlight lead to different minimal time necessary to obtain the total bleaching of the quartz sample. (authors)

  12. Sunlight and Vitamin D: A global perspective for health.

    Science.gov (United States)

    Wacker, Matthias; Holick, Michael F

    2013-01-01

    Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences.

  13. Increased mortality associated with extreme-heat exposure in King County, Washington, 1980-2010

    Science.gov (United States)

    Isaksen, Tania Busch; Fenske, Richard A.; Hom, Elizabeth K.; Ren, You; Lyons, Hilary; Yost, Michael G.

    2016-01-01

    Extreme heat has been associated with increased mortality, particularly in temperate climates. Few epidemiologic studies have considered the Pacific Northwest region in their analyses. This study quantified the historical (May to September, 1980-2010) heat-mortality relationship in the most populous Pacific Northwest County, King County, Washington. A relative risk (RR) analysis was used to explore the relationship between heat and all-cause mortality on 99th percentile heat days, while a time series analysis, using a piece-wise linear model fit, was used to estimate the effect of heat intensity on mortality, adjusted for temporal trends. For all ages, all causes, we found a 10 % (1.10 (95 % confidence interval (CI), 1.06, 1.14)) increase in the risk of death on a heat day versus non-heat day. When considering the intensity effect of heat on all-cause mortality, we found a 1.69 % (95 % CI, 0.69, 2.70) increase in the risk of death per unit of humidex above 36.0 °C. Mortality stratified by cause and age produced statistically significant results using both types of analyses for: all-cause, non-traumatic, circulatory, cardiovascular, cerebrovascular, and diabetes causes of death. All-cause mortality was statistically significantly modified by the type of synoptic weather type. These results demonstrate that heat, expressed as humidex, is associated with increased mortality on heat days, and that risk increases with heat's intensity. While age was the only individual-level characteristic found to modify mortality risks, statistically significant increases in diabetes-related mortality for the 45-64 age group suggests that underlying health status may contribute to these risks.

  14. The effects of drying following heat shock exposure of the desert moss Syntrichia caninervis.

    Science.gov (United States)

    Xu, Shu-Jun; Liu, Chun-Jiang; Jiang, Ping-An; Cai, Wei-Min; Wang, Yan

    2009-03-15

    Desert mosses are components of biological soil crusts (BSCs) and their ecological functions make assessment and protection of these mosses a high-ranking management priority in desert regions. Drying is thought to be useful for desert mosses surviving heat shock. In this study, we investigated the role of drying by monitoring the responses of physiological characters and asexual reproduction in the typical desert moss Syntrichia caninervis. Heat significantly decreased chlorophyll content and weakened rapid recovery of photochemical activity, and increased carotenoid content and membrane permeability. Lethal temperatures significantly destroyed shoot regeneration potential. In comparison with heat alone, drying significantly increased protonema emergence time and depressed protonema emergence area. Drying combined with heat accelerated water loss, followed by a decrease of photosynthetic activity. Drying had different influences on membrane permeability at different temperatures. When moss leaves were subjected to a combined stress of drying and heat shock, photosynthesis was maintained mainly due to the effects of drying on physiological activity although the cellular morphological integrity was affected. Drying caused opposing effects on moss physiological and reproductive characteristics. On the one hand, drying caused a positive synergistic effect with heat shock when the temperature was below 40 degrees C. On the other hand, drying showed antagonism with heat shock when the moss was subjected to temperatures higher than 40 degrees C. These findings may help in understanding the survival mechanism of dessert mosses under heat shock stress which will be helpful for the artificial reconstruction of BSCs.

  15. The effects of drying following heat shock exposure of the desert moss Syntrichia caninervis

    International Nuclear Information System (INIS)

    Xu Shujun; Liu Chunjiang; Jiang Pingan; Cai Weimin; Wang Yan

    2009-01-01

    Desert mosses are components of biological soil crusts (BSCs) and their ecological functions make assessment and protection of these mosses a high-ranking management priority in desert regions. Drying is thought to be useful for desert mosses surviving heat shock. In this study, we investigated the role of drying by monitoring the responses of physiological characters and asexual reproduction in the typical desert moss Syntrichia caninervis. Heat significantly decreased chlorophyll content and weakened rapid recovery of photochemical activity, and increased carotenoid content and membrane permeability. Lethal temperatures significantly destroyed shoot regeneration potential. In comparison with heat alone, drying significantly increased protonema emergence time and depressed protonema emergence area. Drying combined with heat accelerated water loss, followed by a decrease of photosynthetic activity. Drying had different influences on membrane permeability at different temperatures. When moss leaves were subjected to a combined stress of drying and heat shock, photosynthesis was maintained mainly due to the effects of drying on physiological activity although the cellular morphological integrity was affected. Drying caused opposing effects on moss physiological and reproductive characteristics. On the one hand, drying caused a positive synergistic effect with heat shock when the temperature was below 40 deg. C. On the other hand, drying showed antagonism with heat shock when the moss was subjected to temperatures higher than 40 deg. C. These findings may help in understanding the survival mechanism of dessert mosses under heat shock stress which will be helpful for the artificial reconstruction of BSCs

  16. Charles Burchfield: "October Wind and Sunlight in the Woods."

    Science.gov (United States)

    Fitzgerald, Gaynell

    1986-01-01

    Based on Charles Burchfield's watercolor, "October Wind and Sunlight in the Woods," the goal of this lesson is to introduce students in grades seven through nine to Burchfield's use of symbolism. (JDH)

  17. Analytic Models for Sunlight Charging of a Rapidly Spinning Satellite

    National Research Council Canada - National Science Library

    Tautz, Maurice

    2003-01-01

    ... photoelectrons can be blocked by local potential barriers. In this report, we discuss two analytic models for sunlight charging of a rapidly spinning spherical satellite, both of which are based on blocked photoelectron currents...

  18. 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.

  19. 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

  20. Accelerated stability testing of organic photovoltaics using concentrated sunlight

    DEFF Research Database (Denmark)

    Katz, Eugene A.; Manor, Assaf; Mescheloff, Asaf

    2012-01-01

    We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported.......We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported....

  1. Biodegradation and photooxidation of crude oil under natural sunlight in the northern Gulf of Mexico

    Science.gov (United States)

    Bacosa, H. P.; Erdner, D.; Liu, Z.

    2016-02-01

    An enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico (nGoM) following the Deepwater Horizon (DWH) spill. While the oil degradation and bacterial communities in the deep-sea plume have been widely investigated, the effect of sunlight on oil and bacterial assemblages in surface waters have received less attention. In this study, we amended surface water collected near the DWH site with crude oil and/or Corexit dispersant and incubated under natural sunlight in the nGoM for 36 d in summer of 2013. The residual alkanes, polycyclic aromatic hydrocarbons (PAHs), and alkalyted PAHs were analyzed by GC-MS, and bacterial community was determined via pyrosequencing. The results show that n-alkane biodegradation rate constants (first order) were ca. ten-fold higher than the photooxidation rate constants. While biodegradation was characterized by a lag phase, photooxidation rate constants for the 2-3 ring and 4-5 ring PAHs, were 0.08-0.98 day-1 and 0.01-0.07 day-1, respectively. Compared to biodegradation, photooxidation increased the transformation of 4-5 ring PAHs by 70% and 3-4 ring alkylated PAHs by 36%. Sunlight significantly reduced bacterial diversity and a driver of shifts in bacterial community structure in oil and Corexit treatments. In amended treatments, sunlight increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Halomonas and Bartonella, while the dark treatments enriched Thalassobius, Winogradskyella, Alcanivorax, Formosa, Eubacterium, Erythrobacter, Natronocella, and Pseudomonas. This suggests that different bacteria are degrading the hydrocarbons in the dark and under light exposure. In a follow up study using DNA-Stable isotope probing (SIP), we identified the alkane and PAH degraders using 13C-labeled hexadecane and phenanthrene, respectively. The results of metagenomic and metatranscriptomic analyses in the light and dark incubations will be presented. For the first

  2. Sunlight Induced Rapid Oil Absorption and Passive Room-Temperature Release: An Effective Solution toward Heavy Oil Spill Cleanup

    KAUST Repository

    Wu, Mengchun

    2018-05-18

    Rapid cleanup and easy recovery of spilled heavy oils is always a great challenge due to their high viscosity (>103 mPa s). One of the efficient methods to absorb highly viscous oils is to reduce their viscosity by increasing their temperature. In this work, the authors integrate the sunlight‐induced light‐to‐heat conversion effect of polypyrrole (PPy) and thermoresponsive property of poly(N‐isopropylacrylamide) (PNIPAm) into the melamine sponge, which successfully delivers a fast heavy oil absorption under sunlight and passive oil release underwater at room temperature. Thanks to the rationally designed functionalities, the PNIPAm/PPy functionalized sponges possess oleophilicity and hydrophobicity under sunlight. Due to the photothermal effect of PPy, the sponges locally heat up contacting heavy oil under sunlight and reduce its viscosity to a point where the oil voluntarily flow into the pores of the sponge. The material in this work is able to rapidly absorb the heavy oil with room temperature viscosity as high as ≈1.60 × 105 mPa s. The absorbed oil can be passively forced out the sponge underwater at room temperature due to the hydrophilicity of PNIPAm. The sunlight responsive and multifunctional sponge represents a meaningful attempt in coming up with a sustainable solution toward heavy oil spill.

  3. Sunlight Induced Rapid Oil Absorption and Passive Room-Temperature Release: An Effective Solution toward Heavy Oil Spill Cleanup

    KAUST Repository

    Wu, Mengchun; Shi, Yusuf; Chang, Jian; Li, Renyuan; Ong, Chi Siang; Wang, Peng

    2018-01-01

    Rapid cleanup and easy recovery of spilled heavy oils is always a great challenge due to their high viscosity (>103 mPa s). One of the efficient methods to absorb highly viscous oils is to reduce their viscosity by increasing their temperature. In this work, the authors integrate the sunlight‐induced light‐to‐heat conversion effect of polypyrrole (PPy) and thermoresponsive property of poly(N‐isopropylacrylamide) (PNIPAm) into the melamine sponge, which successfully delivers a fast heavy oil absorption under sunlight and passive oil release underwater at room temperature. Thanks to the rationally designed functionalities, the PNIPAm/PPy functionalized sponges possess oleophilicity and hydrophobicity under sunlight. Due to the photothermal effect of PPy, the sponges locally heat up contacting heavy oil under sunlight and reduce its viscosity to a point where the oil voluntarily flow into the pores of the sponge. The material in this work is able to rapidly absorb the heavy oil with room temperature viscosity as high as ≈1.60 × 105 mPa s. The absorbed oil can be passively forced out the sponge underwater at room temperature due to the hydrophilicity of PNIPAm. The sunlight responsive and multifunctional sponge represents a meaningful attempt in coming up with a sustainable solution toward heavy oil spill.

  4. Computational estimation of decline in sweating in the elderly from measured body temperatures and sweating for passive heat exposure

    International Nuclear Information System (INIS)

    Hirata, Akimasa; Nomura, Tomoki; Laakso, Ilkka

    2012-01-01

    Several studies reported the difference in heat tolerance between younger and older adults, which may be attributable to the decline in the sweating rate. One of the studies suggested a hypothesis that the dominant factor causing the decline in sweating was the decline in thermal sensitivity due to a weaker signal from the periphery to the regulatory centres. However, no quantitative investigation of the skin temperature threshold for activating the sweating has been conducted in previous studies. In this study, we developed a computational code to simulate the time evolution of the temperature variation and sweating in realistic human models under heat exposure, in part by comparing the computational results with measured data from younger and older adults. Based on our computational results, the difference in the threshold temperatures for activating the thermophysiological response, especially for sweating, is examined between older and younger adults. The threshold for activating sweating in older individuals was found to be about 1.5 °C higher than that in younger individuals. However, our computation did not suggest that it was possible to evaluate the central alteration with ageing by comparing the computation with the measurements for passive heat exposure, since the sweating rate is marginally affected by core temperature elevation at least for the scenarios considered here. The computational technique developed herein is useful for understanding the thermophysiological response of older individuals from measured data. (note)

  5. Summer indoor heat exposure and respiratory and cardiovascular distress calls in New York City, NY, U.S.

    Science.gov (United States)

    Uejio, C K; Tamerius, J D; Vredenburg, J; Asaeda, G; Isaacs, D A; Braun, J; Quinn, A; Freese, J P

    2016-08-01

    Most extreme heat studies relate outdoor weather conditions to human morbidity and mortality. In developed nations, individuals spend ~90% of their time indoors. This pilot study investigated the indoor environments of people receiving emergency medical care in New York City, NY, U.S., from July to August 2013. The first objective was to determine the relative influence of outdoor conditions as well as patient characteristics and neighborhood sociodemographics on indoor temperature and specific humidity (N = 764). The second objective was to determine whether cardiovascular or respiratory cases experience hotter and more humid indoor conditions as compared to controls. Paramedics carried portable sensors into buildings where patients received care to passively monitor indoor temperature and humidity. The case-control study compared 338 respiratory cases, 291 cardiovascular cases, and 471 controls. Intuitively, warmer and sunnier outdoor conditions increased indoor temperatures. Older patients who received emergency care tended to occupy warmer buildings. Indoor-specific humidity levels quickly adjusted to outdoor conditions. Indoor heat and humidity exposure above a 26 °C threshold increased (OR: 1.63, 95% CI: 0.98-2.68, P = 0.056), but not significantly, the proportion of respiratory cases. Indoor heat exposures were similar between cardiovascular cases and controls. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. A new mathematical approximation of sunlight attenuation in rocks for surface luminescence dating

    Energy Technology Data Exchange (ETDEWEB)

    Laskaris, Nikolaos, E-mail: nick.laskaris@gmail.com [University of the Aegean, Department of Mediterranean Studies, Laboratory of Archaeometry, 1 Demokratias Avenue, Rhodes 85100 (Greece); Liritzis, Ioannis, E-mail: liritzis@rhodes.aegean.gr [University of the Aegean, Department of Mediterranean Studies, Laboratory of Archaeometry, 1 Demokratias Avenue, Rhodes 85100 (Greece)

    2011-09-15

    The attenuation of sunlight through different rock surfaces and the thermoluminescence (TL) or Optical stimulated luminescence (OSL) residuals clock resetting derived from sunlight induced eviction of electrons from electron traps, is a prerequisite criterion for potential dating. The modeling of change of residual luminescence as a function of two variables, the solar radiation path length (or depth) and exposure time offers further insight into the dating concept. The double exponential function modeling based on the Lambert-Beer law, valid under certain assumptions, constructed by a quasi-manual equation fails to offer a general and statistically sound expression of the best fit for most rock types. A cumulative log-normal distribution fitting provides a most satisfactory mathematical approximation for marbles, marble schists and granites, where absorption coefficient and residual luminescence parameters are defined per each type of rock or marble quarry. The new model is applied on available data and age determination tests. - Highlights: > Study of aattenuation of sunlight through different rock surfaces. > Study of the thermoluminescence (TL) or Optical stimulated luminescence (OSL) residuals as a function of depth. > A Cumulative Log-Normal Distribution fitting provides the most satisfactory modeling for marbles, marble schists and granites. > The new model (Cummulative Log-Norm Fitting) is applied on available data and age determination tests.

  7. A new mathematical approximation of sunlight attenuation in rocks for surface luminescence dating

    International Nuclear Information System (INIS)

    Laskaris, Nikolaos; Liritzis, Ioannis

    2011-01-01

    The attenuation of sunlight through different rock surfaces and the thermoluminescence (TL) or Optical stimulated luminescence (OSL) residuals clock resetting derived from sunlight induced eviction of electrons from electron traps, is a prerequisite criterion for potential dating. The modeling of change of residual luminescence as a function of two variables, the solar radiation path length (or depth) and exposure time offers further insight into the dating concept. The double exponential function modeling based on the Lambert-Beer law, valid under certain assumptions, constructed by a quasi-manual equation fails to offer a general and statistically sound expression of the best fit for most rock types. A cumulative log-normal distribution fitting provides a most satisfactory mathematical approximation for marbles, marble schists and granites, where absorption coefficient and residual luminescence parameters are defined per each type of rock or marble quarry. The new model is applied on available data and age determination tests. - Highlights: → Study of aattenuation of sunlight through different rock surfaces. → Study of the thermoluminescence (TL) or Optical stimulated luminescence (OSL) residuals as a function of depth. → A Cumulative Log-Normal Distribution fitting provides the most satisfactory modeling for marbles, marble schists and granites. → The new model (Cummulative Log-Norm Fitting) is applied on available data and age determination tests.

  8. Adaptive fluid lens and sunlight redirection system : exploring a novel way of redirecting and altering sunlight in large span roofs

    NARCIS (Netherlands)

    Heinzelmann, F.; Bristogianni, T.; Teuffel, P.; Stouffs, R.; Sariyildiz, S.

    2013-01-01

    The paper describes a novel system to alter and redirect sunlight under large span roofs with the help of a fluid lens system. Focus lies on the computational design, testing, measurement and evaluation of the performance of a physical prototype.

  9. 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

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

    Science.gov (United States)

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2015-09-01

    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 B1+ 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.

  11. Beetle Exoskeleton May Facilitate Body Heat Acting Differentially across the Electromagnetic Spectrum.

    Science.gov (United States)

    Carrascal, Luis M; Ruiz, Yolanda Jiménez; Lobo, Jorge M

    Exoskeletons of beetles and their associated morphological characteristics can serve many different functions, including thermoregulation. We study the thermal role of the exoskeleton in 13 Geotrupidae dung beetle species using heating experiments under controlled conditions. The main purpose was to measure the influence of heating sources (solar radiance vs. infrared), animal position (dorsal exposure vs. ventral exposure), species identity, and phylogenetic relationships on internal asymptotic temperatures and heating rates. The thermal response was significantly influenced by phylogenetic relatedness, although it was not affected by the apterous condition. The asymptotic internal temperature of specimens was not affected by the thoracic volume but was significantly higher under simulated sunlight conditions than under infrared radiation and when exposed dorsally as opposed to ventrally. There was thus a significant interaction between heating source and body position. Heating rate was negatively and significantly influenced by thoracic volume, and, although insignificantly slower under simulated sunlight, it was significantly affected by body position, being faster under dorsal exposure. The results constitute the first evidence supporting the hypothesis that the beetle exoskeleton acts differentially across the electromagnetic spectrum determining internal body temperatures. This interesting finding suggests the existence of a kind of passive physiology imposed by the exoskeleton and body size, where interspecific relationships play a minor role.

  12. Sunlight creates oxygenated species in water-soluble fractions of Deepwater horizon oil

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Phoebe Z. [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Chen, Huan [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Podgorski, David C. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Future Fuels Institute, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); McKenna, Amy M. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Tarr, Matthew A., E-mail: mtarr@uno.edu [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States)

    2014-09-15

    Graphical abstract: Sunlight oxygenates petroleum. - Highlights: • Oxidation seen in water-soluble oil fraction after exposure to simulated sunlight. • Oxygen addition occurred across a wide range of carbon number and DBE. • Oil compounds were susceptible to addition of multiple oxygens to each molecule. • Results provide understanding of fate of oil on water after exposure to sunlight. - Abstract: In order to assess the impact of sunlight on oil fate, Macondo well oil from the Deepwater Horizon (DWH) rig was mixed with pure water and irradiated with simulated sunlight. After irradiation, the water-soluble organics (WSO) from the dark and irradiated samples were extracted and characterized by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Liquid–liquid extraction yielded two fractions from dark and irradiated water/oil mixtures: acidic WSOs (negative-ion electrospray (ESI)), and base/neutral WSOs (positive-ion ESI) coupled to FT-ICR MS to catalog molecular-level transformations that occur to Macondo-derived WSOs after solar irradiation. Such direct measure of oil phototransformation has not been previously reported. The most abundant heteroatom class detected in the irradiated WSO acid fractions correspond to molecules that contain five oxygens (O{sub 5}), while the most abundant acids in the dark samples contain two oxygen atoms per molecule (O{sub 2}). Higher-order oxygen classes (O{sub 5}–O{sub 9}) were abundant in the irradiated samples, but <1.5% relative abundance in the dark sample. The increased abundance of higher-order oxygen classes in the irradiated samples relative to the dark samples indicates that photooxidized components of the Macondo crude oil become water-soluble after irradiation. The base/neutral fraction showed decreased abundance of pyridinic nitrogen (N{sub 1}) concurrent with an increased abundance of N{sub 1}O{sub x} classes after irradiation. The predominance of higher

  13. Effect of high-flux H/He plasma exposure on tungsten damage due to transient heat loads

    Energy Technology Data Exchange (ETDEWEB)

    De Temmerman, G., E-mail: gregory.detemmerman@iter.org [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregion Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); ITER Organization, Route de Vinon sur Verdon, CS 90 096, 13067 Saint Paul-lez-Durance (France); Morgan, T.W.; Eden, G.G. van; Kruif, T. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregion Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); Wirtz, M. [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Microstructure and Properties of Materials (IEK-2), EURATOM Association, 52425 Jülich (Germany); Matejicek, J.; Chraska, T. [Institute of Plasma Physics, Association EURATOM-IPP, CR Prague (Czech Republic); Pitts, R.A. [ITER Organization, Route de Vinon sur Verdon, CS 90 096, 13067 Saint Paul-lez-Durance (France); Wright, G.M. [MIT Plasma Science and Fusion Center, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2015-08-15

    The thermal shock behaviour of tungsten exposed to high-flux plasma is studied using a high-power laser. The cases of laser-only, sequential laser and hydrogen (H) plasma and simultaneous laser plus H plasma exposure are studied. H plasma exposure leads to an embrittlement of the material and the appearance of a crack network originating from the centre of the laser spot. Under simultaneous loading, significant surface melting is observed. In general, H plasma exposure lowers the heat flux parameter (F{sub HF}) for the onset of surface melting by ∼25%. In the case of He-modified (fuzzy) surfaces, strong surface deformations are observed already after 1000 laser pulses at moderate F{sub HF} = 19 MJ m{sup −2} s{sup −1/2}, and a dense network of fine cracks is observed. These results indicate that high-fluence ITER-like plasma exposure influences the thermal shock properties of tungsten, lowering the permissible transient energy density beyond which macroscopic surface modifications begin to occur.

  14. Nanoindentation study of the combined effects of crystallography, heat treatment and exposure to high-flux deuterium plasma in tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Zayachuk, Y., E-mail: yevhen.zayachuk@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Armstrong, D.E.J. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Bystrov, K. [FOM Institute DIFFER- Dutch Institute for Fundamental Energy Research, Trilateral Euregio Cluster, De Zaale 20, 3612 AJ Eindhoven (Netherlands); Van Boxel, S. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Morgan, T. [FOM Institute DIFFER- Dutch Institute for Fundamental Energy Research, Trilateral Euregio Cluster, De Zaale 20, 3612 AJ Eindhoven (Netherlands); Roberts, S.G. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2017-04-01

    tungsten samples were heat-treated to achieve partial recrystallization and exposed to high ion flux deuterium plasma at different temperatures and fluences. Continuous stiffness nanoindentation measurements of near-surface hardness were performed in the grains of specific annealing states and of specific crystallographic orientation, determined by electron backscatter diffraction (EBSD); indentation pile-up was investigated using surface profilometry. Bulk hardness of unexposed tungsten does not strongly depend on grain orientation, but depends on the annealing state of the grain, with values between ∼4.3 GPa for recrystallized grains and ∼5.5 for non-recrystallized ones. Grains with <111> surface normal orientation feature the least pile-up, while grains with <001> orientation the most; pile-up also depends on the annealing state, being generally lower in recrystallized grains. Plasma exposure leads to the increase of hardness, most significantly near the surface. The width of plasma-affected zone increases with the increase of exposure temperature and fluence, as well in recrystallized grains, correlating with the increase of diffusion depth. Plasma exposure does not lead to the emergence of orientation-dependence of hardness. Both indentation pile-up and near-surface indentation pop-ins are generally suppressed by plasma exposure.

  15. Effect of heat exposure on gene expression of feed intake regulatory peptides in laying hens.

    Science.gov (United States)

    Song, Zhigang; Liu, Lei; Sheikhahmadi, Ardashir; Jiao, Hongchao; Lin, Hai

    2012-01-01

    The aim of this paper was to investigate the effect of heat stress on the regulation of appetite-associated genes in laying hens. Forty eight laying hens were randomly divided into two circumstances: high (31 ± 1.5°C; relative humidity, 82.0 ± 2.2%) or normal (20 ± 2°C, control; relative humidity, 60.1 ± 4.5%) ambient environment. Heat stress decreased body weight gain (P feed intake (P feed efficiency (P feed intake in laying hens under high ambient temperature.

  16. Heat exposure of Cannabis sativa extracts affects the pharmacokinetic and metabolic profile in healthy male subjects.

    Science.gov (United States)

    Eichler, Martin; Spinedi, Luca; Unfer-Grauwiler, Sandra; Bodmer, Michael; Surber, Christian; Luedi, Markus; Drewe, Juergen

    2012-05-01

    The most important psychoactive constituent of CANNABIS SATIVA L. is Δ (9)-tetrahydrocannabinol (THC). Cannabidiol (CBD), another important constituent, is able to modulate the distinct unwanted psychotropic effect of THC. In natural plant extracts of C. SATIVA, large amounts of THC and CBD appear in the form of THCA-A (THC-acid-A) and CBDA (cannabidiolic acid), which can be transformed to THC and CBD by heating. Previous reports of medicinal use of cannabis or cannabis preparations with higher CBD/THC ratios and use in its natural, unheated form have demonstrated that pharmacological effects were often accompanied with a lower rate of adverse effects. Therefore, in the present study, the pharmacokinetics and metabolic profiles of two different C. SATIVA extracts (heated and unheated) with a CBD/THC ratio > 1 were compared to synthetic THC (dronabinol) in a double-blind, randomized, single center, three-period cross-over study involving 9 healthy male volunteers. The pharmacokinetics of the cannabinoids was highly variable. The metabolic pattern was significantly different after administration of the different forms: the heated extract showed a lower median THC plasma AUC (24 h) than the unheated extract of 2.84 vs. 6.59 pmol h/mL, respectively. The later was slightly higher than that of dronabinol (4.58 pmol h/mL). On the other hand, the median sum of the metabolites (THC, 11-OH-THC, THC-COOH, CBN) plasma AUC (24 h) was higher for the heated than for the unheated extract. The median CBD plasma AUC (24 h) was almost 2-fold higher for the unheated than for the heated extract. These results indicate that use of unheated extracts may lead to a beneficial change in metabolic pattern and possibly better tolerability. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Early-phase immunodetection of metallothionein and heat shock proteins in extruded earthworm coelomocytes after dermal exposure to metal ions

    International Nuclear Information System (INIS)

    Homa, Joanna; Olchawa, Ewa; Stuerzenbaum, Stephen R.; John Morgan, A.; Plytycz, Barbara

    2005-01-01

    This paper provides direct evidence that earthworm immune cells, coelomocytes, are exposed to bio-reactive quantities of metals within 3 days after dermal exposure, and that they respond by upregulating metallothionein (MT) and heat shock protein (HSP70, HSP72) expression. Indirect support for the hypothesis that coelomocytes are capable of trafficking metals was also obtained. Coelomocytes were expelled from adult individuals of Eisenia fetida after 3-day exposure either to metal ions (Zn, Cu, Pb, Cd) or to distilled water (controls) via filter papers. The number of coelomocytes was significantly decreased after Cu, Pb, or Cd treatment. Cytospin preparations of coelomocytes were subjected to immunoperoxidase staining with monoclonal antibodies against human heat shock proteins (HSP70 or HSP72), or rabbit polyclonal antibodies raised against metallothionein 2 (w-MT2) of Lumbricus rubellus. Applied antibodies detected the respective proteins of E. fetida and revealed that the expression of HSP70, HSP72 and w-MT2 proteins was either induced or significantly enhanced in coelomocytes from metal-exposed animals. In conclusion, stress protein expression in earthworm coelomocytes may be used as sensitive biomarkers of metal contaminations. Further experimentation is needed for quantitative analysis of kinetics of metal-induced stress protein expression in earthworm coelomocytes. - Metals upregulate stress response proteins in earthworm coelomocytes

  18. Early-phase immunodetection of metallothionein and heat shock proteins in extruded earthworm coelomocytes after dermal exposure to metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Homa, Joanna [Department of Evolutionary Immunobiology, Institute of Zoology, Jagiellonian University, R. Ingardena 6, PL 30-060 Cracow (Poland); Olchawa, Ewa [Department of Evolutionary Immunobiology, Institute of Zoology, Jagiellonian University, R. Ingardena 6, PL 30-060 Cracow (Poland); Stuerzenbaum, Stephen R. [Cardiff School of Biosciences, Cardiff University, PO Box 915, Cardiff Wales CF10 3TL (United Kingdom); John Morgan, A. [Cardiff School of Biosciences, Cardiff University, PO Box 915, Cardiff Wales CF10 3TL (United Kingdom); Plytycz, Barbara [Department of Evolutionary Immunobiology, Institute of Zoology, Jagiellonian University, R. Ingardena 6, PL 30-060 Cracow (Poland)]. E-mail: plyt@zuk.iz.uj.edu.pl

    2005-05-01

    This paper provides direct evidence that earthworm immune cells, coelomocytes, are exposed to bio-reactive quantities of metals within 3 days after dermal exposure, and that they respond by upregulating metallothionein (MT) and heat shock protein (HSP70, HSP72) expression. Indirect support for the hypothesis that coelomocytes are capable of trafficking metals was also obtained. Coelomocytes were expelled from adult individuals of Eisenia fetida after 3-day exposure either to metal ions (Zn, Cu, Pb, Cd) or to distilled water (controls) via filter papers. The number of coelomocytes was significantly decreased after Cu, Pb, or Cd treatment. Cytospin preparations of coelomocytes were subjected to immunoperoxidase staining with monoclonal antibodies against human heat shock proteins (HSP70 or HSP72), or rabbit polyclonal antibodies raised against metallothionein 2 (w-MT2) of Lumbricus rubellus. Applied antibodies detected the respective proteins of E. fetida and revealed that the expression of HSP70, HSP72 and w-MT2 proteins was either induced or significantly enhanced in coelomocytes from metal-exposed animals. In conclusion, stress protein expression in earthworm coelomocytes may be used as sensitive biomarkers of metal contaminations. Further experimentation is needed for quantitative analysis of kinetics of metal-induced stress protein expression in earthworm coelomocytes. - Metals upregulate stress response proteins in earthworm coelomocytes.

  19. Chemically enhanced sunlight for killing bacteria

    International Nuclear Information System (INIS)

    Block, S.S.; Goswami, D.Y.

    1995-01-01

    Solar ultraviolet (UV) photocatalyzed oxidation of chemicals with titanium dioxide (TiO 2 ) has received considerable attention. Much less recognized, however, is the ability of the same system to destroy bacteria. This study examined this phenomenon and the conditions that affect it. Bacteria in aqueous solution were given solar exposure with titanium dioxide and their survival with time was determined. Lamps with a predominantly solar ultraviolet spectrum were also used in the experiments. Without exposure to UV light, TiO 2 had no deleterious effect on the bacteria. However, several common bacteria on solar exposure in the presence of TiO 2 were killed in just a few minutes, whereas without TiO 2 it took over an hour to destroy them. A concentration of 0.01% TiO 2 was most effective in killing bacteria and 10-fold concentrations lower or higher were successively less effective. Inorganic and organic compounds in solution, even in small amounts, interfered with the efficiency of killing. Alkaline solution also reduced the bactericidal activity. Circulation and agitation provided by stirring to keep the TiO 2 particles suspended reduced the time necessary to kill the bacteria. Time-intensity curves for killing bacteria were the same general shape with or without TiO 2 , indicating that TiO 2 served merely as a catalyst to increase the rate of the reaction but that the mechanism of action was not changed. The shape of the curves show that the organisms are sensitized with a minimum intensity of radiation and that an increase doesn't greatly increase the rate of kill. Below this critical intensity, however, the time required for killing markedly increases as the intensity is decreased

  20. Pengaruh Suhu Terhadap Tegangan Permukaan Sabun Cuci Piring Cair Buatan Sendiri, Sunlight, Dan S.O.S

    OpenAIRE

    Siahaan, Okio Patar

    2011-01-01

    The effect of temperature on the surface tension of homemade liquid dish soap, Sunlight, and SOS was carried out. The temperatures was variated 280C(without heating), 300C, 400C and 500C. The homemade liquid dish soap was prepared by using an active ingredients. The active ingredient of the liquid dishwashing soap were sodium lauryl ether sulphate, sodium alkyl benzene sulfonate, and sodium lauril ether sulfate, respectively. The determination of surface tension was based the increasing of t...

  1. 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

  2. Successful pacing using a batteryless sunlight-powered pacemaker.

    Science.gov (United States)

    Haeberlin, Andreas; Zurbuchen, Adrian; Schaerer, Jakob; Wagner, Joerg; Walpen, Sébastien; Huber, Christoph; Haeberlin, Heinrich; Fuhrer, Juerg; Vogel, Rolf

    2014-10-01

    Today's cardiac pacemakers are powered by batteries with limited energy capacity. As the battery's lifetime ends, the pacemaker needs to be replaced. This surgical re-intervention is costly and bears the risk of complications. Thus, a pacemaker without primary batteries is desirable. The goal of this study was to test whether transcutaneous solar light could power a pacemaker. We used a three-step approach to investigate the feasibility of sunlight-powered cardiac pacing. First, the harvestable power was estimated. Theoretically, a subcutaneously implanted 1 cm(2) solar module may harvest ∼2500 µW from sunlight (3 mm implantation depth). Secondly, ex vivo measurements were performed with solar cells placed under pig skin flaps exposed to a solar simulator and real sunlight. Ex vivo measurements under real sunlight resulted in a median output power of 4941 µW/cm(2) [interquartile range (IQR) 3767-5598 µW/cm(2), median skin flap thickness 3.0 mm (IQR 2.7-3.3 mm)]. The output power strongly depended on implantation depth (ρSpearman = -0.86, P pacemaker powered by a 3.24 cm(2) solar module was implanted in vivo in a pig to measure output power and to pace. In vivo measurements showed a median output power of >3500 µW/cm(2) (skin flap thickness 2.8-3.84 mm). Successful batteryless VVI pacing using a subcutaneously implanted solar module was performed. Based on our results, we estimate that a few minutes of direct sunlight (irradiating an implanted solar module) allow powering a pacemaker for 24 h using a suitable energy storage. Thus, powering a pacemaker by sunlight is feasible and may be an alternative energy supply for tomorrow's pacemakers. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  3. Enhancement of parathion toxicity to quail by heat and cold exposure

    Science.gov (United States)

    Rattner, B.A.; Becker, J.M.; Nakatsugawa, T.

    1987-01-01

    Effects of ambient temperature on the acute oral toxicity of parathion were investigated in Japanese quail (Coturnix japonica) maintained at thermoneutral temperature (26.degree. C) or exposed to elevated (37.degree. C) or reduced (4.degree. C) temperatures commonly encountered by free-ranging wild birds. Based upon estimates of the median lethal dosage, there was up to a two-fold enhancement of parathion toxicity in birds chronically exposed to heat or cold. Twenty-four hours after administration of a low dosage (4 mg/kg body wt, po), there was markedly greater cholinesterase inhibition in surviving heat-exposed quail compared with those reared at 26.degree. C (e.g., brain acetylcholinesterase depression of 42% versus 12%). There were no differences in hepatic activities of parathion oxidase, paraoxonase, or paraoxon deethylase which could account for greater toxicity to chronically heat-exposed birds. In contrast, 4 mg parathion/kg wt elicited less plasma cholinesterase inhibition in cold-exposed quail compared to thermoneutral controls (e.g., birds is substantially influenced by environmental temperature.

  4. Terrestrial photovoltaic power systems with sunlight concentration. Annual progress report, January 1, 1975--December 31, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Backus, C.E.

    1976-01-31

    This annual report is for the second year of a program to investigate the characteristics of the components and the total system using sunlight concentrated onto solar cells. The second year was primarily to experimentally investigate the conclusions of the first year of analytical studies. Cells have been fabricated that are designed for different intensities. Typically the efficiency of a cell will increase from its 11 percent at AM1 peak to efficiency at the designed concentration level and return to its initial efficiency at about 3 times its designed concentration level. The developed cells have been tested under high intensity simulators and in concentrated sunlight and have shown to have the predicted response. The experimental testing of passive cooling limitations for cooling cells with just finned arrangements in the back of the cell has been completed in the controlled environment of a wind tunnel. These experiments have confirmed the heat transfer coefficients that had been used in the analytical studies. Testing was done to collect heat transfer coefficients for actual wind conditions and these data show good agreement with the controlled wind tunnel data. Four photovoltaic/concentrator system experiments have been started with CR of about 3, 10, 25, and 100. System analysis has indicated that photovoltaic concentration systems may be attractive in low solar irradiation areas such as Cleveland.

  5. 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

  6. Photodegradation of pharmaceuticals in the aquatic environment by sunlight and UV-A, -B and -C irradiation.

    Science.gov (United States)

    Kawabata, Kohei; Sugihara, Kazumi; Sanoh, Seigo; Kitamura, Shigeyuki; Ohta, Shigeru

    2013-01-01

    In order to investigate the effect of sunlight on the persistence and ecotoxicity of pharmaceuticals contaminating the aquatic environment, we exposed nine pharmaceuticals (acetaminophen (AA), amiodarone (AM), dapsone (DP), dexamethasone (DX), indomethacin (IM), naproxen (NP), phenytoin (PH), raloxifene (RL), and sulindac (SL)) in aqueous media to sunlight and to ultraviolet (UV) irradiation at 254, 302 or 365 nm (UV-C, UV-B or UV-A, respectively). Degradation of the pharmaceuticals was monitored by means of high-performance liquid chromatography (HPLC). Sunlight completely degraded AM, DP and DX within 6 hr, and partly degraded the other pharmaceuticals, except AA and PH, which were not degraded. Similar results were obtained with UV-B, while UV-A was less effective (both UV-A and -B are components of sunlight). All the pharmaceuticals were photodegraded by UV-C, which is used for sterilization in sewage treatment plants. Thus, the photodegradation rates of pharmaceuticals are dependent on both chemical structure and the wavelength of UV exposure. Toxicity assay using the luminescent bacteria test (ISO11348) indicated that UV irradiation reduced the toxicity of some pharmaceuticals to aquatic organisms by decreasing their amount (photodegradation) and increased the toxicity of others by generating toxic photoproduct(s). These results indicate the importance of investigating not only parent compounds, but also photoproducts in the risk assessment of pharmaceuticals in aquatic environments.

  7. Emergency department visits of young children and long-term exposure to neighbourhood smoke from household heating - The Growing Up in New Zealand child cohort study.

    Science.gov (United States)

    Lai, Hak Kan; Berry, Sarah D; Verbiest, Marjolein E A; Tricker, Peter J; Atatoa Carr, Polly E; Morton, Susan M B; Grant, Cameron C

    2017-12-01

    In developed countries, exposure to wood or coal smoke occurs predominantly from neighbourhood emissions arising from household heating. The effect of this exposure on child health is not well characterized. Within a birth cohort study in New Zealand we assessed healthcare events associated with exposure to neighbourhood smoke from household heating. Our outcome measure was non-accidental presentations to hospital emergency departments (ED) before age three years. We matched small area-level census information with the geocoded home locations to measure the density of household heating with wood or coal in the neighbourhood and applied a time-weighted average exposure method to account for residential mobility. We then used hierarchical multiple logistic regression to assess the independence of associations of this exposure with ED presentations adjusted for gender, ethnicity, birth weight, breastfeeding, immunizations, number of co-habiting smokers, wood or coal heating at home, bedroom mold, household- and area-level deprivation and rurality. The adjusted odds ratio of having a non-accidental ED visit was 1.07 [95%CI: 1.03-1.12] per wood or coal heating household per hectare. We found a linear dose-response relationship (p-value for trend = 0.024) between the quartiles of exposure (1st as reference) and the same outcome (odds ratio in 2nd to 4th quartiles: 1.14 [0.95-1.37], 1.28 [1.06-1.54], 1.32 [1.09-1.60]). Exposure to neighbourhoods with higher density of wood or coal smoke-producing households is associated with an increased odds of ED visits during early childhood. Policies that reduce smoke pollution from domestic heating by as little as one household per hectare using solid fuel burners could improve child health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Dissolved organic carbon biodegradability from thawing permafrost stimulated by sunlight rather than inorganic nitrogen

    Science.gov (United States)

    Liu, F.; Chen, L.; Zhang, B.; Wang, G.; Qin, S.; Yang, Y.

    2017-12-01

    Permafrost thaw could result in a large portion of frozen carbon being laterally transferred to aquatic ecosystems as dissolved organic carbon (DOC). During this delivery process, the size of biodegradable DOC (BDOC) determines the proportion of DOC mineralized by microorganisms and associated carbon loss to the atmosphere, which may further trigger positive carbon-climate feedback. Thermokarst is an abrupt permafrost thaw process that can enhance DOC export and also impact DOC processing through increased inorganic nitrogen (N) and sunlight exposure. However, it remains unclear how thermokarst-impacted BDOC responds to inorganic N addition and ultraviolet (UV) light irradiation. Here we explored the responses of DOC concentration, composition and its biodegradability to inorganic N and UV light in a typical thermokarst on the Tibetan Plateau, by combining field observation and laboratory incubation with spectra analyses (UV-visible absorption and three-dimensional fluorescence spectra) and parallel factor analyses. Our results showed that BDOC in thermokarst feature outflows was significantly higher than in reference water. Furthermore, inorganic N addition had no influence on thermokarst-impacted BDOC, whereas exposure to UV light significantly increased BDOC by as much as 2.3 times higher than the dark-control. Moreover, N addition and UV irradiation did not generate additive effects on BDOC. These results imply that sunlight rather than inorganic N can increase thermokarst-derived BDOC, potentially strengthening the positive permafrost carbon-climate feedback.

  9. Ergonomics and Beyond: Understanding How Chemical and Heat Exposures and Physical Exertions at Work Affect Functional Ability, Injury, and Long-Term Health.

    Science.gov (United States)

    Ross, Jennifer A; Shipp, Eva M; Trueblood, Amber B; Bhattacharya, Amit

    2016-08-01

    To honor Tom Waters's work on emerging occupational health issues, we review the literature on physical along with chemical exposures and their impact on functional outcomes. Many occupations present the opportunity for exposure to multiple hazardous exposures, including both physical and chemical factors. However, little is known about how these different factors affect functional ability and injury. The goal of this review is to examine the relationships between these exposures, impairment of the neuromuscular and musculoskeletal systems, functional outcomes, and health problems with a focus on acute injury. Literature was identified using online databases, including PubMed, Ovid Medline, and Google Scholar. References from included articles were searched for additional relevant articles. This review documented the limited existing literature that discussed cognitive impairment and functional disorders via neurotoxicity for physical exposures (heat and repetitive loading) and chemical exposures (pesticides, volatile organic compounds [VOCs], and heavy metals). This review supports that workers are exposed to physical and chemical exposures that are associated with negative health effects, including functional impairment and injury. Innovation in exposure assessment with respect to quantifying the joint exposure to these different exposures is especially needed for developing risk assessment models and, ultimately, preventive measures. Along with physical exposures, chemical exposures need to be considered, alone and in combination, in assessing functional ability and occupationally related injuries. © 2016, Human Factors and Ergonomics Society.

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

    Science.gov (United States)

    Karampatzakis, Andreas; Samaras, Theodoros

    2013-05-01

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

  11. Sunlight-enhanced catalytic degradation over Ag–CuO ...

    Indian Academy of Sciences (India)

    Herein, we report sunlight-activated photo-catalysis response of direct current radio frequency (DC/RF)-sputtered Ag–CuO nanoparticles thin films.We have adopted this approach for facile removal and easy recovery of thin filmsafter use. Ag was incorporated at 2.5 and 5.4 wt% with reference to pure CuO. Structural ...

  12. Effect of sunlight, transport and storage vessels on drinking water ...

    African Journals Online (AJOL)

    Effect of sunlight, transport and storage vessels on drinking water quality in rural Ghana. ... on drinking water quality in rural Ghana. K Obiri-Danso, E Amevor, LA Andoh, K Jones ... Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  13. Electricity from Sunlight: The Future of Photovoltaics. Worldwatch Paper 52.

    Science.gov (United States)

    Flavin, Christopher

    Solar photovoltaic cells have been called the ultimate energy technology, environmentally benign and without moving parts, solar cells directly convert sunlight into electricity. Photovoltaic energy conversion is fundamentally different from all other forms of electricity generation. Without turbines, generators or other mechanical equipment, it…

  14. Effect of sunlight shielding on leaf structure and amino acids ...

    African Journals Online (AJOL)

    Light sensitive albino tea cultivar 'Jinguang' (Camellia sinensis) which grows albinism leaf in yellow colour, results to high level of amino acids but low levels of photosynthetic pigments including chlorophylls, neoxanthin, violaxanthin, phytoxanthin and β-carotene when it is exposed to high sunlight illumination in the ...

  15. Turning Sunlight into Electricity-Inorganic Solar Cells and Beyond

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Turning Sunlight into Electricity - Inorganic Solar Cells and Beyond. A K Shukla. Volume 16 Issue 12 December 2011 pp 1294-1302. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. Strain change and creep behavior of STACIR/AW power line with heat exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.G.; Park, S.D.; Kim, S.S.; Lee, H.W. [Overhead Conductor Research Lab., Korea Electrotechnology Research Inst., Changwon (Korea)

    2005-07-01

    As a way to expand electric capacity in power line with hovering of electric power demand, STACIR/AW (super thermal-resistant Al alloy conductors Al-clad Invar-reinforced) overhead conductor which cans double ampacity has been developed. The STACIR/AW power line is mechanically composite stranded wire composed of INVAR/AW stranded wire as core for sag control and heat-resistant aluminum alloy for delivering doubled electric current. Recently, in order to ensure stable line operation and to predict its span of life, the changes of thermal properties for STACIR/AW have been investigated. In the present work, the changes of strain with temperature and the creep behavior as important factors in sag control will be presented. The transition temperature of STACIR/AW 410 sqmm was estimated approximately 130 C and the creep rates were decreased with temperatures. (orig.)

  17. 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 responses

  18. 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

  19. 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.

  20. 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

  1. Construction of computational program of aging in insulating materials for searching reversed sequential test conditions to give damage equivalent to simultaneous exposure of heat and radiation

    International Nuclear Information System (INIS)

    Fuse, Norikazu; Homma, Hiroya; Okamoto, Tatsuki

    2013-01-01

    Two consecutive numerical calculations on degradation of polymeric insulations under thermal and radiation environment are carried out to simulate so-called reversal sequential acceleration test. The aim of the calculation is to search testing conditions which provide material damage equivalent to the case of simultaneous exposure of heat and radiation. At least following four parameters are needed to be considered in the sequential method; dose rate and exposure time in radiation, as well as temperature and aging time in heating. The present paper discusses the handling of these parameters and shows some trial calculation results. (author)

  2. The relationship between long-term sunlight radiation and cognitive decline in the REGARDS cohort study

    Science.gov (United States)

    Kent, Shia T.; Kabagambe, Edmond K.; Wadley, Virginia G.; Howard, Virginia J.; Crosson, William L.; Al-Hamdan, Mohammad Z.; Judd, Suzanne E.; Peace, Fredrick; McClure, Leslie A.

    2014-04-01

    Sunlight may be related to cognitive function through vitamin D metabolism or circadian rhythm regulation. The analysis presented here sought to test whether ground and satellite measures of solar radiation are associated with cognitive decline. The study used a 15-year residential history merged with satellite and ground monitor data to determine sunlight (solar radiation) and air temperature exposure for a cohort of 19,896 cognitively intact black and white participants aged 45+ from the 48 contiguous United States. Exposures of 15, 10, 5, 2, and 1-year were used to predict cognitive status at the most recent assessment in logistic regression models; 1-year insolation and maximum temperatures were chosen as exposure measures. Solar radiation interacted with temperature, age, and gender in its relationships with incident cognitive impairment. After adjustment for covariates, the odds ratio (OR) of cognitive decline for solar radiation exposure below the median vs above the median in the 3rd tertile of maximum temperatures was 1.88 (95 % CI: 1.24, 2.85), that in the 2nd tertile was 1.33 (95 % CI: 1.09, 1.62), and that in the 1st tertile was 1.22 (95 % CI: 0.92, 1.60). We also found that participants under 60 years old had an OR = 1.63 (95 % CI: 1.20, 2.22), those 60-80 years old had an OR = 1.18 (95 % CI: 1.02, 1.36), and those over 80 years old had an OR = 1.05 (0.80, 1.37). Lastly, we found that males had an OR = 1.43 (95 % CI: 1.22, 1.69), and females had an OR = 1.02 (0.87, 1.20). We found that lower levels of solar radiation were associated with increased odds of incident cognitive impairment.

  3. In vitro assessment of tissue heating near metallic medical implants by exposure to pulsed radio frequency diathermy

    International Nuclear Information System (INIS)

    Ruggera, P S; Witters, D M; Maltzahn, G von; Bassen, H I

    2003-01-01

    A patient with bilateral implanted neurostimulators suffered significant brain tissue damage, and subsequently died, following diathermy treatment to hasten recovery from teeth extraction. Subsequent MRI examinations showed acute deterioration of the tissue near the deep brain stimulator (DBS) lead's electrodes which was attributed to excessive tissue heating induced by the diathermy treatment. Though not published in the open literature, a second incident was reported for a patient with implanted neurostimulators for the treatment of Parkinson's disease. During a diathermy treatment for severe kyphosis, the patient had a sudden change in mental status and neurological deficits. The diathermy was implicated in causing damage to the patient's brain tissue. To investigate if diathermy induced excessive heating was possible with other types of implantable lead systems, or metallic implants in general, we conducted a series of in vitro laboratory tests. We obtained a diathermy unit and also assembled a controllable laboratory exposure system. Specific absorption rate (SAR) measurements were performed using fibre optic thermometry in proximity to the implants to determine the rate of temperature rise using typical diathermy treatment power levels. Comparisons were made of the SAR measurements for a spinal cord stimulator (SCS) lead, a pacemaker lead and three types of bone prosthesis (screws, rods and a plate). Findings indicate that temperature changes of 2.54 and 4.88 deg. C s -1 with corresponding SAR values of 9129 and 17 563 W kg -1 near the SCS and pacemaker electrodes are significantly higher than those found in the proximity of the other metallic implants which ranged from 0.04 to 0.69 deg C s -1 (129 to 2471 W kg -1 ). Since the DBS leads that were implanted in the reported human incidents have one-half the electrode surface area of the tested SCS lead, these results imply that tissue heating at rates at least equal to or up to twice as much as those reported

  4. 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.

  5. Dynamic light absorption of biomass-burning organic carbon photochemically aged under natural sunlight

    Science.gov (United States)

    Zhong, M.; Jang, M.

    2014-02-01

    Wood-burning aerosol produced under smoldering conditions was photochemically aged with different relative humidity (RH) and NOx conditions using a 104 m3 dual outdoor chamber under natural sunlight. Light absorption of organic carbon (OC) was measured over the course of photooxidation using a UV-visible spectrometer connected to an integrating sphere. At high RH, the color decayed rapidly. NOx slightly prolonged the color of wood smoke, suggesting that NOx promotes the formation of chromophores via secondary processes. Overall, the mass absorption cross section (integrated between 280 and 600 nm) of OC increased by 11-54% (except high RH) in the morning and then gradually decreased by 19-68% in the afternoon. This dynamic change in light absorption of wood-burning OC can be explained by two mechanisms: chromophore formation and sunlight bleaching. To investigate the effect of chemical transformation on light absorption, wood smoke particles were characterized using various spectrometers. The intensity of fluorescence, which is mainly related to polycyclic aromatic hydrocarbons (PAHs), rapidly decreased with time, indicating the potential bleaching of PAHs. A decline of levoglucosan concentrations evinced the change of primary organic aerosol with time. The aerosol water content measured by Fourier transform infrared spectroscopy showed that wood-burning aerosol became less hygroscopic as photooxidation proceeded. A similar trend in light absorption changes has been observed in ambient smoke aerosol originating from the 2012 County Line wildfire in Florida. We conclude that the biomass-burning OC becomes less light absorbing after 8-9 h sunlight exposure compared to fresh wood-burning OC.

  6. Dynamic light absorption of biomass burning organic carbon photochemically aged under natural sunlight

    Science.gov (United States)

    Zhong, M.; Jang, M.

    2013-08-01

    Wood burning aerosol produced under smoldering conditions was photochemically aged with different relative humidity (RH) and NOx conditions using a 104 m3 dual outdoor chamber under natural sunlight. Light absorption of organic carbon (OC) was measured over the course of photooxidation using a UV-visible spectrometer connected to an integrating sphere. At high RH, the color decayed rapidly. NOx slightly prolonged the color of wood smoke, suggesting that NOx promotes the formation of chromophores via secondary processes. Overall, the mass absorption cross-section (integrated between 280 nm and 600 nm) of OC increased by 11-54% (except high RH) in the morning and then gradually decreased by 19-68% in the afternoon. This dynamic change in light absorption of wood burning OC can be explained by two mechanisms: chromophore formation and sunlight bleaching. To investigate the effect of chemical transformation on light absorption, wood smoke particles were characterized using various spectrometers. The intensity of fluorescence, which is mainly related to polycyclic aromatic hydrocarbons (PAHs), rapidly decreased with time indicating the potential bleaching of PAHs. A decline of levoglucosan concentrations evinced the change of POA with time. The aerosol water content measured by Fourier transform infrared spectroscopy showed that wood burning aerosol became less hygroscopic as photooxidation proceeded. A similar trend in light absorption changes has been observed in ambient smoke aerosol originating from the 2012 County Line Wildfire in Florida. We conclude that the biomass burning OC becomes less light absorbing after 8-9 h sunlight exposure compared to fresh wood burning OC.

  7. Cockle Temperature Exposure Lab Experiment (2016)

    Data.gov (United States)

    U.S. Environmental Protection Agency — We carried out a lab experiment in which we exposed cockles to a range of air temperatures to simulate the physiological rigors of exposure to sunlight and air at...

  8. 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.

  9. 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.

  10. 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 attentional capacity showed best performance at the beginning of night shifts in contrast to any other time that the task was completed; however, performance degraded dramatically over the course of the night shift [χ(2) (2, n = 12) = 6.50, 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.

  11. Knowledge of vitamin D and perceptions and attitudes toward sunlight among Chinese middle-aged and elderly women: a population survey in Hong Kong

    Directory of Open Access Journals (Sweden)

    Lee Ka-Kui

    2006-09-01

    Full Text Available Abstract Background Physical and biological risk factors for vitamin D inadequacy are known; however, cultural- and population-specific behaviours and attitudes that influence these risk factors, particularly among Asian people, are less well documented. To understand more about prevailing attitudes and behaviour toward sunlight and knowledge of vitamin D among a population at greater risk of impaired vitamin D status, poor bone health and osteoporosis, we conducted a telephone interview survey of 547 middle-aged and elderly Chinese women living in Hong Kong. Methods All telephone interviews were conducted using the Computer Assisted Telephone Technique and target respondents were selected by random sampling. Interviews were conducted in Cantonese and eighteen main questions were asked pertaining to personal characteristics, perceptions, attitudes and behaviour toward sunlight, and knowledge about vitamin D. Results The survey results showed that 62.3% (n = 341 did not like going in the sun and 66.7% of respondents spent an average of 6–10 hours indoors, between 6:30 am and 7:00 pm, during weekdays. However, 58% of people thought that they had enough exposure to sunlight. The majority had heard of vitamin D, but knowledge about the role and sources of vitamin D was low. Among those who knew that sunlight was a source of vitamin D, the majority spent less than 1 h in the sun in the past week (76.4% vs 23.6%, 1 h in the sun in the past week, chi-square p Conclusion The survey revealed considerable ignorance and confusion about the role of sunlight in vitamin D production, and the function and sources of vitamin D. Attitudes and behaviour toward sunlight were largely negative and many took measures to avoid sunlight, particularly among younger (middle-aged women who had good awareness of vitamin D.

  12. Cumulative effects of heat exposure and storage conditions of Oxytocin-in-Uniject in rural Ghana: implications for scale up.

    Science.gov (United States)

    Mullany, Luke C; Newton, Sam; Afari-Asiedu, Samuel; Adiibokah, Edward; Agyemang, Charlotte T; Cofie, Patience; Brooke, Steve; Owusu-Agyei, Seth; Stanton, Cynthia K

    2014-08-01

    Postpartum hemorrhage can be reduced substantially in home deliveries attended by community-based workers by using Oxytocin-in-Uniject (OIU) devices affixed with temperature-time indicators. We characterized the distribution of time to discard of these devices when stored under normal field conditions in Ghana. Two drug storage simulation studies were conducted in rural Ghana in 2011 and 2012. Devices were transported under refrigeration from manufacture (Argentina) to storage at the study site. Twenty-three field workers each stored at home (unrefrigerated) 25 OIU devices and monitored them daily to record: (1) time to transition from usable to unusable, and (2) continuous digital ambient temperature to determine heat exposure over the simulation period. Time to discard was estimated and compared with mean kinetic temperature exposure of the devices during the shipment and storage phases and with characteristics of the storage locations using Weibull regression models. We used the time to discard distributions in a Monte Carlo simulation to estimate wastage rates in a hypothetical program setting. Time for shipment and transfer to long-term refrigerated storage and mean kinetic temperature during the shipment phase was 8.6 days/10.3°C and 13.4 days/12.1°C, for the first and second simulation studies, respectively. Median (range) time to discard when stored under field conditions (unrefrigerated) was 43 (6 to 59) days and 33 (14 to 50) days, respectively. Mean time to discard was 10.0 days shorter in the second simulation, during which mean kinetic temperature exposure was 3.9°C higher. Simulating a monthly distribution system and assuming typical usage, predicted wastage of product was less than 10%. The time to discard of devices was highly sensitive to small changes in temperature exposure. Under field conditions typical in rural Ghana, OIU packages will have a half-life of approximately 30 to 40 days based on the temperature monitor used during the study

  13. Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster.

    Science.gov (United States)

    Reshef, Noam; Walbaum, Natasha; Agam, Nurit; Fait, Aaron

    2017-01-01

    Vineyards are characterized by their large spatial variability of solar irradiance (SI) and temperature, known to effectively modulate grape metabolism. To explore the role of sunlight in shaping fruit composition and cluster uniformity, we studied the spatial pattern of incoming irradiance, fruit temperature and metabolic profile within individual grape clusters under three levels of sunlight exposure. The experiment was conducted in a vineyard of Cabernet Sauvignon cv. located in the Negev Highlands, Israel, where excess SI and midday temperatures are known to degrade grape quality. Filtering SI lowered the surface temperature of exposed fruits and increased the uniformity of irradiance and temperature in the cluster zone. SI affected the overall levels and patterns of accumulation of sugars, organic acids, amino acids and phenylpropanoids, across the grape cluster. Increased exposure to sunlight was associated with lower accumulation levels of malate, aspartate, and maleate but with higher levels of valine, leucine, and serine, in addition to the stress-related proline and GABA. Flavan-3-ols metabolites showed a negative response to SI, whereas flavonols were highly induced. The overall levels of anthocyanins decreased with increased sunlight exposure; however, a hierarchical cluster analysis revealed that the members of this family were grouped into three distinct accumulation patterns, with malvidin anthocyanins and cyanidin-glucoside showing contrasting trends. The flavonol-glucosides, quercetin and kaempferol, exhibited a logarithmic response to SI, leading to improved cluster uniformity under high-light conditions. Comparing the within-cluster variability of metabolite accumulation highlighted the stability of sugars, flavan-3-ols, and cinnamic acid metabolites to SI, in contrast to the plasticity of flavonols. A correlation-based network analysis revealed that extended exposure to SI modified metabolic coordination, increasing the number of negative

  14. 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.

  15. Prevalence of sun exposure and its associated factors in southern Brazil: a population-based study.

    Science.gov (United States)

    Duquia, Rodrigo Pereira; Menezes, Ana Maria Baptista; Almeida, Hiram Larangeira de; Reichert, Felipe Fossati; Santos, Iná da Silva dos; Haack, Ricardo Lanzetta; Horta, Bernardo Lessa

    2013-01-01

    Sunlight exposure is responsible for a large number of dermatological diseases. We estimated the prevalence of sunlight exposure and its associated factors in adults from southern Brazil in a cross-sectional, population-based study. We investigated a representative sample of individuals aged ≥ 20 years (n=3,136). Sunlight exposure and its associated factors were evaluated in two distinct situations: at leisure time and at work. The time period investigated ranged from December 2004 to March 2005, comprising 120 days of the highest ultraviolet index in the urban area of the city of Pelotas, in southern Brazil. The participants were asked about sunlight exposure for at least 20 minutes between 10 A.M. and 4 P.M. The analysis was stratified by sex, and sunlight exposure was grouped into five categories. Among the 3,136 participants, prevalence of sunlight exposure at the beach was 32.8% (95% CI, 30.3 - 35.2) and 26.3% (95% CI, 24.2 28.3) among men and women, respectively. The prevalence at work was 39.8% (95% CI, 37.2 - 42.4) among men and 10.5% (95% CI, 9.1 - 12.0) among women. Age was inversely associated with sunlight exposure. Family income and achieved schooling were positively associated with sunlight exposure at leisure time and inversely associated with sunglight exposure at work. Self-reported skin color was not associated. Knowledge of any friend or relative who has been affected by skin cancer was positively associated with sunlight exposure among men at work. Despite the media campaigns on the harmful effects of excessive sunlight exposure, we found a high prevalence of sunlight exposure during a period of high ultraviolet index.

  16. Prevalence of sun exposure and its associated factors in southern Brazil: a population-based study*

    Science.gov (United States)

    Duquia, Rodrigo Pereira; Menezes, Ana Maria Baptista; de Almeida, Hiram Larangeira; Reichert, Felipe Fossati; dos Santos, Iná da Silva; Haack, Ricardo Lanzetta; Horta, Bernardo Lessa

    2013-01-01

    BACKGROUND Sunlight exposure is responsible for a large number of dermatological diseases. OBJECTIVE We estimated the prevalence of sunlight exposure and its associated factors in adults from southern Brazil in a cross-sectional, population-based study. METHODS We investigated a representative sample of individuals aged ≥ 20 years (n=3,136). Sunlight exposure and its associated factors were evaluated in two distinct situations: at leisure time and at work. The time period investigated ranged from December 2004 to March 2005, comprising 120 days of the highest ultraviolet index in the urban area of the city of Pelotas, in southern Brazil. The participants were asked about sunlight exposure for at least 20 minutes between 10 A.M. and 4 P.M. The analysis was stratified by sex, and sunlight exposure was grouped into five categories. RESULTS Among the 3,136 participants, prevalence of sunlight exposure at the beach was 32.8% (95% CI, 30.3 - 35.2) and 26.3% (95% CI, 24.2 28.3) among men and women, respectively. The prevalence at work was 39.8% (95% CI, 37.2 - 42.4) among men and 10.5% (95% CI, 9.1 - 12.0) among women. Age was inversely associated with sunlight exposure. Family income and achieved schooling were positively associated with sunlight exposure at leisure time and inversely associated with sunglight exposure at work. Self-reported skin color was not associated. Knowledge of any friend or relative who has been affected by skin cancer was positively associated with sunlight exposure among men at work. CONCLUSION Despite the media campaigns on the harmful effects of excessive sunlight exposure, we found a high prevalence of sunlight exposure during a period of high ultraviolet index. PMID:24068126

  17. Natural sunlight bleaching of the aluminum center in quartz

    International Nuclear Information System (INIS)

    Lin Min; Yin Gongming; Han Kongyan; Bao Jifei; Liu Jingwei; Jia Li

    2007-01-01

    The effect of sunlight bleaching on ESR signals from the aluminum center in quartz is reported for two samples of sand-sized quartz, one from a granite and one from a beach sand. The grains were exposed to direct sunlight for periods of time up to 500 h, with bleaching carried out in four different cities in China that are from 50 to 3600 m above sea level. Each sample bleached to the same residual level, ∼55% for the granite and 80% for the beach sand of the initial value after a 200 Gy dose had been given. After 200 h, the bleaching level reached was independent of the height above sea level

  18. Intensity correlation imaging with sunlight-like source

    Science.gov (United States)

    Wang, Wentao; Tang, Zhiguo; Zheng, Huaibin; Chen, Hui; Yuan, Yuan; Liu, Jinbin; Liu, Yanyan; Xu, Zhuo

    2018-05-01

    We show a method of intensity correlation imaging of targets illuminated by a sunlight-like source both theoretically and experimentally. With a Faraday anomalous dispersion optical filter (FADOF), we have modulated the coherence time of a thermal source up to 0.167 ns. And we carried out measurements of temporal and spatial correlations, respectively, with an intensity interferometer setup. By skillfully using the even Fourier fitting on the very sparse sampling data, the images of targets are successfully reconstructed from the low signal-noise-ratio(SNR) interference pattern by applying an iterative phase retrieval algorithm. The resulting imaging quality is as well as the one obtained by the theoretical fitting. The realization of such a case will bring this technique closer to geostationary satellite imaging illuminated by sunlight.

  19. 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

    2018-03-01

    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

  20. In vitro assessment of tissue heating near metallic medical implants by exposure to pulsed radio frequency diathermy

    Energy Technology Data Exchange (ETDEWEB)

    Ruggera, P S; Witters, D M; Maltzahn, G von; Bassen, H I [Center for Devices and Radiological Health, Food and Drug Administration, HFZ-133, 9200 Corporate Blvd., Rockville, MD 20850 (United States)

    2003-09-07

    A patient with bilateral implanted neurostimulators suffered significant brain tissue damage, and subsequently died, following diathermy treatment to hasten recovery from teeth extraction. Subsequent MRI examinations showed acute deterioration of the tissue near the deep brain stimulator (DBS) lead's electrodes which was attributed to excessive tissue heating induced by the diathermy treatment. Though not published in the open literature, a second incident was reported for a patient with implanted neurostimulators for the treatment of Parkinson's disease. During a diathermy treatment for severe kyphosis, the patient had a sudden change in mental status and neurological deficits. The diathermy was implicated in causing damage to the patient's brain tissue. To investigate if diathermy induced excessive heating was possible with other types of implantable lead systems, or metallic implants in general, we conducted a series of in vitro laboratory tests. We obtained a diathermy unit and also assembled a controllable laboratory exposure system. Specific absorption rate (SAR) measurements were performed using fibre optic thermometry in proximity to the implants to determine the rate of temperature rise using typical diathermy treatment power levels. Comparisons were made of the SAR measurements for a spinal cord stimulator (SCS) lead, a pacemaker lead and three types of bone prosthesis (screws, rods and a plate). Findings indicate that temperature changes of 2.54 and 4.88 deg. C s{sup -1} with corresponding SAR values of 9129 and 17 563 W kg{sup -1} near the SCS and pacemaker electrodes are significantly higher than those found in the proximity of the other metallic implants which ranged from 0.04 to 0.69 deg C s{sup -1} (129 to 2471 W kg{sup -1}). Since the DBS leads that were implanted in the reported human incidents have one-half the electrode surface area of the tested SCS lead, these results imply that tissue heating at rates at least equal to or up to

  1. Coupled optic-thermodynamic analysis of a novel wireless power transfer system using concentrated sunlight for space applications

    International Nuclear Information System (INIS)

    Zhong, Ming-Liang; Li, Yun-Ze; Mao, Yu-Feng; Liang, Yi-Hao; Liu, Jia

    2017-01-01

    Highlights: • A novel space wireless power transfer system is proposed. • Concentrated sunlight is used as the medium to avoid multiple conversions. • Fresnel lens and optical fiber bundle make the system compact and space-qualified. • Coupled optic-thermodynamic model is developed to analyze link efficiencies. • End-to-end efficiency achieved is as twice as that of microwave or laser system. - Abstract: The energy generation and supply for in-orbit spacecraft have become an urgent problem concerning efficient and economical utilization of spacecraft formation flying. To fill the gap between the requirement of inter-spacecraft energy transfer and the development of wireless power transfer, this paper presents a novel wireless power transfer system whose transmission medium is concentrated sunlight. The system concentrates sunlight using a Fresnel lens, and changes the direction of concentrated sunlight beam with optical fibers. The light energy is converted to thermal form by a heat collector, and then it is utilized to generate electricity by a Stirling engine integrated with linear alternator. Equipments employed on fractionated spacecraft shall be supported by this electric energy. A coupled optic-thermodynamic model was developed to analyze system link efficiencies. This system offers characteristics such as high flexibility, relatively low cost for launch and maintenance, and most importantly, high end-to-end efficiency. Simulation results show that the geometric concentration ratio and the temperature ratio of expansion and compression spaces are two key parameters of this system. Output power of 234.3 W was achieved on the distance of 100 m, and the end-to-end efficiency of the system was above 20%.

  2. Technical-economic feasibility of orbiting sunlight reflectors

    Science.gov (United States)

    Alferov, Z.; Minin, V.

    1986-02-01

    The use of deflectors in orbit as a means of providing artificial illumination is examined. Considerations of technical and economic feasibility are addressed. Three main areas of application are distinguished: reflecting sunlight onto the surface of the Earth; concentration of the flow of solar energy on an orbiting receiver; and retransmission of optical radiation. The advantages of the artificial Earth illumination application of the orbiting reflector scheme in terms of energy savings in lighting cities, and additional daylight time for critical periods of farming operations are discussed.

  3. Analysis, distribution, and dietary exposure of glyoxal and methylglyoxal in cookies and their relationship with other heat-induced contaminants.

    Science.gov (United States)

    Arribas-Lorenzo, Gema; Morales, Francisco J

    2010-03-10

    Thermal processing of food leads to the formation of dicarbonyls such as glyoxal (GO) and methylglyoxal (MGO), which are potentially harmful because they are precursors of advanced glycation end products (AGEs). GO and MGO formation was examined during the baking process of cookies as cookies are a widely distributed food commodity in Western diets. GO and MGO were chromatographically analyzed after employment of an improved method of derivatization with orthophenylenediamine to produce stable quinoxaline derivatives. Sample extraction, cleanup, and chromatographic conditions were evaluated to provide an in-house validated procedure for GO and MGO analysis in cookies. Quantification limits were set at 1.5 and 2 mg/kg for GO and MGO, respectively, with an average recovery of 103% and a calculated precision lower than 7%. Studies were carried out both on laboratory-scale cookies under controlled conditions and on commercial samples as well. GO and MGO values in commercial cookies ranged from 4.8 to 26.0 mg/kg and from 3.7 to 81.4 mg/kg, respectively. Commercial cookies made from ammonium bicarbonate and fructose showed the highest levels of MGO. Dicarbonyls were rapidly formed on the upper side of the cookie regardless of the shape or thickness of the samples, confirming there was a surface effect. Under controlled baking conditions, the formations of GO and MGO were linearly correlated with baking time. MGO formation was related with acrylamide, a heat-processing contaminant, in commercial cookies, but this relationship was not observed for 5-hydroxymethylfurfural. Dietary exposure of the Spanish population to GO and MGO from cookies was estimated to be 213 and 216 microg/person/day, respectively.

  4. 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

  5. Passive heat exposure induced by hot water leg immersion increased oxyhemoglobin in pre-frontal cortex to preserve oxygenation and did not contribute to impaired cognitive functioning

    Science.gov (United States)

    Wijayanto, Titis; Toramoto, Sayo; Tochihara, Yutaka

    2013-07-01

    This study investigated the effects of passive heat exposure on pre-frontal cortex oxygenation and cognitive functioning, specifically to examine whether the change in pre-frontal cortex oxygenation coincided with cognitive functioning during heat exposure. Eleven male students who participated in this study immersed their lower legs to the knees in three different water temperatures, 38 °C, 40 °C, and 42 °C water in an air temperature of 28 º C and 50 % relative humidity for 60 min. After 45 min of leg immersion they performed cognitive functioning tasks assessing their short-term memory while immersing their lower legs. There were higher rectal temperature ( P 0.05). No statistical difference in cognitive functioning among the three conditions was observed with a higher increase of oxyhemoglobin during the cognitive functioning in the 42 °C condition for the left ( P = 0.05) and right ( P thermally comfortable.

  6. Nocturnal light pollution and underexposure to daytime sunlight: Complementary mechanisms of circadian disruption and related diseases.

    Science.gov (United States)

    Smolensky, Michael H; Sackett-Lundeen, Linda L; Portaluppi, Francesco

    2015-01-01

    Routine exposure to artificial light at night (ALAN) in work, home, and community settings is linked with increased risk of breast and prostate cancer (BC, PC) in normally sighted women and men, the hypothesized biological rhythm mechanisms being frequent nocturnal melatonin synthesis suppression, circadian time structure (CTS) desynchronization, and sleep/wake cycle disruption with sleep deprivation. ALAN-induced perturbation of the CTS melatonin synchronizer signal is communicated maternally at the very onset of life and after birth via breast or artificial formula feedings. Nighttime use of personal computers, mobile phones, electronic tablets, televisions, and the like--now epidemic in adolescents and adults and highly prevalent in pre-school and school-aged children--is a new source of ALAN. However, ALAN exposure occurs concomitantly with almost complete absence of daytime sunlight, whose blue-violet (446-484 nm λ) spectrum synchronizes the CTS and whose UV-B (290-315 nm λ) spectrum stimulates vitamin D synthesis. Under natural conditions and clear skies, day/night and annual cycles of UV-B irradiation drive corresponding periodicities in vitamin D synthesis and numerous bioprocesses regulated by active metabolites augment and strengthen the biological time structure. Vitamin D insufficiency and deficiency are widespread in children and adults in developed and developing countries as a consequence of inadequate sunlight exposure. Past epidemiologic studies have focused either on exposure to too little daytime UV-B or too much ALAN, respectively, on vitamin D deficiency/insufficiency or melatonin suppression in relation to risk of cancer and other, e.g., psychiatric, hypertensive, cardiac, and vascular, so-called, diseases of civilization. The observed elevated incidence of medical conditions the two are alleged to influence through many complementary bioprocesses of cells, tissues, and organs led us to examine effects of the totality of the artificial light

  7. Ocean color remote sensing using polarization properties of reflected sunlight

    Science.gov (United States)

    Frouin, R.; Pouliquen, E.; Breon, F.-M.

    1994-01-01

    The effects of the atmosphere and surface on sunlight backscattered to space by the ocean may be substantially reduced by using the unpolarized component of reflectance instead of total reflectance. At 450 nm, a wavelength of interest in ocean color remote sensing, and for typical conditions, 45% of the unpolarized reflectance may originate from the water body instead of 20% of the total reflectance, which represents a gain of a factor 2.2 in useful signal for water composition retrieval. The best viewing geometries are adjacent to the glitter region; they correspond to scattering angles around 100 deg, but they may change slightly depending on the polarization characteristics of the aerosols. As aerosol optical thickness increases, the atmosphere becomes less efficient at polarizing sunlight, and the enhancement of the water body contribution to unpolarized reflectance is reduced. Since the perturbing effects are smaller on unpolarized reflectance, at least for some viewing geometries, they may be more easily corrected, leading to a more accurate water-leaving signal and, therefore, more accurate estimates of phytoplankton pigment concentration.

  8. Evaluation of sunlight induced structural changes and their effect on the photocatalytic activity of V{sub 2}O{sub 5} for the degradation of phenols

    Energy Technology Data Exchange (ETDEWEB)

    Aslam, M. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ismail, Iqbal M.I. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Salah, Numan [Centre of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chandrasekaran, S. [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Qamar, M.Tariq [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Hameed, A., E-mail: afmuhammad@kau.edu.sa [Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589 (Saudi Arabia); National Centre for Physics, Quaid-e-Azam University, Islamabad 44000 (Pakistan)

    2015-04-09

    Highlights: • The interaction of UV photons of sunlight induces defects in V{sub 2}O{sub 5}. • The photon induced defects promotes the trapping and transfer of excited electrons. • The nature of the substituent at 2-position affects the degradation process. • The formation of the intermediates is influenced by the nature of substituents. • The released ions are subjected further transformation. - Abstract: Despite knowing the fact that vanadium pentoxide is slightly soluble in aqueous medium, its photocatalytic activity was evaluated for the degradation of phenol and its derivatives (2-hydroxyphenol, 2-chlorophenol, 2-aminophenol and 2-nitrophenol) in natural sunlight exposure. The prime objective of the study was to differentiate between the homogeneous and heterogeneous photocatalysis incurred by dissolved and undissolved V{sub 2}O{sub 5} in natural sunlight exposure. V{sub 2}O{sub 5} was synthesized by chemical precipitation procedure using Triton X-100 as morphology mediator and characterized by DRS, PLS, Raman, FESEM and XRD. A lower solubility of ∼5% per 100 ml of water at 23 °C was observed after calcination at 600 °C. The study revealed no contribution of the dissolved V{sub 2}O{sub 5} in the photocatalytic process. In sunlight exposure, V{sub 2}O{sub 5} powder exhibited substantial activity for the degradation, however, a low mineralization of phenolic substrates was observed. The initial low activity of V{sub 2}O{sub 5} followed by a sharp increase both in degradation and mineralization in complete spectrum sunlight exposure, was further investigated that revealed the decrease in the bandgap and the reduction in the particle size with the interaction of UV photons (<420 nm) as this effect was not observable in the exposure of visible region of sunlight. The role of the chemically different substituents attached to an aromatic ring at 2-positions and the secondary interaction of released ions during the degradation process with the reactive

  9. Exposure to UV radiation and human health

    Science.gov (United States)

    Kimlin, Michael G.

    2005-08-01

    This paper will overview the significant issues facing researchers in relating the impact of exposure to sunlight and human health. Exposure to solar ultraviolet radiation is the major causative factor in most sun-related skin and eye disorders, however, very little is known quantitatively about human UV exposures. Interestingly, human exposure to sunlight also has a nutritional impact, namely the development of pre-Vitamin D, which is an important nutrient in bone health. New research suggest that low vitamin D status may be a causative factor in the development of selective types of cancer and autoimminue diseases, as well as a contributing factor in bone health. The 'health duality' aspect of sunlight exposure is an interesting and controversial topic that is a research focus of Kimlin's research group.

  10. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general diversity patterns, despite increased mutation levels at the single

  11. Effect of artificial sunlight on the retention of external calcein marks on lake trout

    Science.gov (United States)

    Honeyfield, D.C.; Kehler, T.; Fletcher, J.W.; Mohler, J.W.

    2008-01-01

    When choosing a fish marking technique to address fishery related questions, it is important to consider factors that affect mark retention. Calcein, a chemical marking agent, is under investigation for potential use on fish. Two laboratory trials were conducted with calcein-marked lake trout Salvelinus namaycush to determine the effect of artificial sunlight on calcein mark intensity. In trial 1, fish exposed to 18,000 lx for 7 d lost 90% or more of the calcein mark intensity (relative to the colorimetric key, mg/L) on the head, body, ventral region, and pectoral fins relative to mark intensity in fish that were maintained in darkness. In trial 2, light intensity was reduced 2.5-3.0-fold. After 7 d of light exposure, calcein mark intensity on the head was reduced by 40-45% relative to mark intensity in fish that were held in darkness; by day 14, calcein mark intensity on the head was reduced by 55-60% relative to that of dark-treated fish. No further decline was observed in light-exposed fish, and head mark intensity values did not differ among days 14, 21, and 28 for this treatment group. Of the four areas evaluated, the head and pectoral fin were more easily read using a colorimetric key than the lateral or ventral regions of the fish. The concentration of calcein spotted on filter paper to devise the colorimetric key ranged from 1 to 100 mg/L. A difference of approximately 7 mg/L in apparent calcein mark intensity means for the head region could be detected using the colorimetric key. These trials showed that calcein mark intensity on lake trout declined when fish were exposed to artificial sunlight, and the use of a colorimetric key improved the objectivity of calcein mark intensity assessment.

  12. Effects of duration of stay in temperate area on thermoregulatory responses to passive heat exposure in tropical south-east Asian males residing in Japan

    Directory of Open Access Journals (Sweden)

    Wijayanto Titis

    2012-09-01

    Full Text Available Abstract Background In this study, we investigated the effects of duration of stay in a temperate area on the thermoregulatory responses to passive heat exposure of residents from tropical areas, particularly to clarify whether they would lose their heat tolerance during passive heat exposure through residence in a temperate country, Japan. Methods We enrolled 12 males (mean ± SE age 25.7 ± 1.3 years from south-east Asian countries who had resided in Japan for a mean of 24.5 ± 5.04 months, and 12 Japanese males (age 24.1 ± 0.9 years. Passive heat exposure was induced through leg immersion in hot water (42°C for 60 minutes under conditions of 28°C air temperature and 50% relative humidity. Results Compared with the Japanese group, the tropical group displayed a higher pre-exposure rectal temperature (P P = 0.03. Additionally, the tropical group showed a tendency towards a lower total sweat rate (P = 0.06 and lower local sweat rate on the forehead (P = 0.07. The tropical group also had a significantly longer sweating onset time on the upper back (P = 0.04 compared with the Japanese groups. The tropical group who stayed in Japan for > 23 months sweated earlier on the forehead and upper back than those who stayed in Japan P P = 0.03 for the forehead and upper back, respectively. There was a positive correlation between duration of stay in Japan and total sweat rate (r = 0.58, P r = −0.73, P = 0.01 and on the upper back (r = −0.66, P = 0.02. Other physiological indices measured in this study did not show any difference between the subjects in the tropical group who had lived in Japan for a shorter time and those who had lived there for a longer time. Conclusions We conclude that the nature of heat acclimatization of the sweating responses to passive heat exposure that are acquired from long-term heat acclimatization is decayed by a stay in a temperate area, as shown

  13. DNA methyltransferases and stress-related genes expression in zebrafish larvae after exposure to heat and copper during reprogramming of DNA methylation.

    Science.gov (United States)

    Dorts, Jennifer; Falisse, Elodie; Schoofs, Emilie; Flamion, Enora; Kestemont, Patrick; Silvestre, Frédéric

    2016-10-12

    DNA methylation, a well-studied epigenetic mark, is important for gene regulation in adulthood and for development. Using genetic and epigenetic approaches, the present study aimed at evaluating the effects of heat stress and copper exposure during zebrafish early embryogenesis when patterns of DNA methylation are being established, a process called reprogramming. Embryos were exposed to 325 μg Cu/L from fertilization (<1 h post fertilization - hpf) to 4 hpf at either 26.5 °C or 34 °C, followed by incubation in clean water at 26.5 °C till 96 hpf. Significant increased mortality rates and delayed hatching were observed following exposure to combined high temperature and Cu. Secondly, both stressors, alone or in combination, significantly upregulated the expression of de novo DNA methyltransferase genes (dnmt3) along with no differences in global cytosine methylation level. Finally, Cu exposure significantly increased the expression of metallothionein (mt2) and heat shock protein (hsp70), the latter being also increased following exposure to high temperature. These results highlighted the sensitivity of early embryogenesis and more precisely of the reprogramming period to environmental challenges, in a realistic situation of combined stressors.

  14. 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...

  15. A generic approach for sunlight and shadow impact computation on large city models

    OpenAIRE

    Jaillot , Vincent; Pedrinis , Frédéric; Servigne , Sylvie; Gesquière , Gilles

    2017-01-01

    International audience; Study of sunlight and shadow effects on the city has become more accessible with the development of 3D citymodels. It allows measuring when and how an object is exposed to the sunlight, which enables conducting manyrelated studies such as energy analyses or urban planning. While many works have been done for this purpose, itmay be interesting to know which objects (terrain, buildings, trees, etc.) prevent other objects from beingexposed to the sunlight. In this paper w...

  16. Effects of Diet and Genetics on Growth Performance of Pigs in Response to Repeated Exposure to Heat Stress

    Directory of Open Access Journals (Sweden)

    Wendy M. Rauw

    2017-10-01

    Full Text Available Heat stress (HS is one of the costliest issues in the U.S. pork industry. Aims of the present study were to determine the consequences of repeated exposure to HS on growth performance, and the effects of a high fiber diet, the genetic potential for high lean tissue accretion, and the genetic potential for residual feed intake (RFI on resilience to HS. Barrows (n = 97 from three genetic lines (commercial, high RFI, low RFI where subjected three times to a 4-day HS treatment (HS1, HS2, and HS3 which was preceded by a 9-day neutral (TN adaptation period (TN1 and alternated by 7-day periods of neutral temperatures (TN2, TN3, and TN4. Body weight gain (BWG, feed intake (FI, feed conversion efficiency (FCE, RFI, and the drop in BWG and FI between TN and HS were estimated for each period, and slaughter traits were measured at the end of TN4. Commercial pigs had lower FI when fed a high fiber diet compared to a regular diet (2.70 ± 0.08 vs. 2.96 ± 0.08 kg/d; P < 0.05, while no differences were found for BWG, RFI or FCE. HS reduced FI, BWG, and FCE, increased RFI, and resulted in leaner pigs that generate smaller carcasses at slaughter. In TN, commercial pigs grew faster than the low and high RFI pigs (1.22 ± 0.06 vs. 0.720 ± 0.05 and 0.657 ± 0.07; P < 0.001 but growth rates were not significantly different between the lines during HS. Growth rates for the low RFI and high RFI pigs were similar both during TN and during HS. Pigs of interest for genetic improvement are those that are able to maintain growth rates during HS. Our results show that response in growth to HS was repeatable over subsequent 4-d HS cycles, which suggests the potential for including this response in the breeding index. The best performing animals during HS are likely those that are not highly superior for growth in TN.

  17. Ultraviolet- and sunlight-induced lipid peroxidation in liposomal membrane

    International Nuclear Information System (INIS)

    Mandal, T.K.; Chatterjee, S.N.

    1980-01-01

    Ultraviolet radiation and sunlight caused lipid peroxidation in the liposomal membrane (as detected by measurement of the oxidation index, A 233 /A 215 , and the amount of malondialdehyde formed) and made the membrane leaky (as revealed by the release of the trapped chromate anions). The oxidation index and the formation of malondialdehyde increased linearly with increasing dose of radiation and depended significantly on the dose rate. The effects were smaller in liposomes derived from Vibrio cholerae phospholipid than in those derived from egg lecithin. The effects of the radiation dose and dose rate on hemolysis and peroxidation (MDA formation) of the erythrocyte membrane followed a similar pattern. A direct correlation between the percentage leakage of chromate (Y) and the oxidation index (X) of the liposomal system was obtained as Y = 236.5 x X

  18. Harvesting Water from Air: Using Anhydrous Salt with Sunlight

    KAUST Repository

    Li, Renyuan

    2018-04-02

    Atmospheric water is abundant alternative water resource, equivalent to 6 times of water in all rivers on Earth. This work screens 14 common anhydrous and hydrated salt couples in terms of their physical and chemical stability, water vapor harvesting and release capacity under relevant application scenarios. Among the salts screened, copper chloride (CuCl2), copper sulfate (CuSO4) and magnesium sulfate (MgSO4) distinguish themselves and are further made into bi-layer water collection devices, with the top layer being photothermal layer while the bottom layer being salt-loaded fibrous membrane. The water collection devices are capable of capturing water vapor out of the air with low relative humidity (down to 15 %) and releasing water under regular and even weakened sunlight (i.e. 0.7 kW/m2). The work shines light on the potential use of anhydrous salt towards producing drinking water in water scarce regions.

  19. Genotoxic action of sunlight upon Bacillus subtilis spores: monitoring studies at Tokyo, Japan.

    Science.gov (United States)

    Munakata, N

    1989-12-01

    Samples of Bacillus subtilis spores dried on membrane filter were exposed to natural sunlight from solar-noon time at Tokyo. The survival and mutation induction of wild-type (UVR) and repair-deficient (UVS) spores were determined on 66 occasions since 1979. Two of the values were considered to be useful in monitoring solar UV intensity; the inverse of the time (in minutes) of exposure to kill 63% of the UVS spores ("sporocidal index") and the induced mutation frequency at 60 minutes of exposure of the UVR spores ("mutagenic index"). Both values were varied greatly due to time of a year, weather and other conditions. Estimates of year-round changes under clear skies were obtained by connecting the maximum values attained in these years. In these curves, there are more than 7-fold differences in the genotoxicity between winter and summer months, with major increases observed in early spring and decreases through autumn. Using a series of UV cut-off filters, the wavelengths most effective for the sporocidal actions were estimated to be in the range of 308-325 nm, shorter wavelengths being effective when the genotoxicity was higher. Sunburn meter of Robertson-Berger type seems to respond to slightly longer wavelength components of the solar spectrum. However, a reasonable correlation was obtained between the reading of the meter and the sporocidal index.

  20. 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.

  1. Acclimation-dependent expression of heat shock protein 70 in Pacific abalone ( Haliotis discus hannai Ino) and its acute response to thermal exposure

    Science.gov (United States)

    Li, Jiaqi; He, Qingguo; Sun, Hui; Liu, Xiao

    2012-01-01

    Heat shock protein 70 (Hsp70) is one important member of heat shock protein (Hsp) family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chronic and acute thermal exposure in Pacific abalone ( Haliotis discus hannai Ino). For the chronic exposure, abalones were maintained at 8, 12, 20, and 30°C for four months and their mRNA levels were measured. The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30°C-acclimated group, followed by the 8°C-acclimated group and then the 12°C- and 20°C-acclimated groups. After the long-term acclimation, gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8°C and 38°C for 30 min. Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure. The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups. Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions, through which they deal with the stress of thermal variations.

  2. Unintentional exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Sliney, D.H.

    1987-01-01

    To evaluate the risks from unintentional exposure to ultraviolet radiation (UVR), and to consider hazard control regulation, one must face first the problem of their state of scientific knowledge and the public's perception of UVR. Few people in the general public would question the health benefits of sunlight. Many flock to the beaches each summer to develop a healthy tan. Since the 1920's scientists have recognized that most of the benefits--and risks--of sunlight exposure result from the UVR present in sunlight. Dermatologists warn sunbathers to avoid exposure or protect themselves against the intense midday UVR or risk skin cancer. A growing number of scientists warn of hazards to the eye if UVR--perhaps even shorter visible wavelengths--are not filtered by lenses. In addition to any intentional exposure for health or cosmetic purposes, many people are also exposed to UVR without being aware of it or without their intent to be exposed. Outdoor workers are exposed to sunlight, many industrial workers (e.g., welders) are exposed to UVR from arc sources, some UVR penetrates clothing, and people indoors are exposed to UVR from artificial lighting

  3. 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.

  4. Analysis of the WCLL European demo blanket concept in terms of activation and decay heat after exposure to neutron irradiation

    Directory of Open Access Journals (Sweden)

    Stankunas Gediminas

    2017-01-01

    Full Text Available This comparative paper describes the activation and decay heat calculations for water-cooled lithium-lead performed part of the EURO fusion WPSAE programme and specifications in comparison to other European DEMO blanket concepts on the basis of using a three-dimensional neutronics calculation model. Results are provided for a range of decay times of interest for maintenance activities, safety and waste management assessments. The study revealed that water-cooled lithium-lead has the highest total decay heat at longer decay times in comparison to the helium-cooled design which has the lowest total decay heat. In addition, major nuclides were identified for water-cooled lithium-lead in W armour, Eurofer, and LiPb. In addition, great attention has been dedicated to the analysis of the decay heat and activity both from the different water-cooled lithium-lead blanket modules for the entire reactor and from each water-cooled lithium-lead blanket module separately. The neutron induced activation and decay heat at shutdown were calculated by the FISPACT code, using the neutron flux densities and spectra that were provided by the preceding MCNP neutron transport calculations.

  5. Asteroid thermal modeling in the presence of reflected sunlight

    Science.gov (United States)

    Myhrvold, Nathan

    2018-03-01

    A new derivation of simple asteroid thermal models is presented, investigating the need to account correctly for Kirchhoff's law of thermal radiation when IR observations contain substantial reflected sunlight. The framework applies to both the NEATM and related thermal models. A new parameterization of these models eliminates the dependence of thermal modeling on visible absolute magnitude H, which is not always available. Monte Carlo simulations are used to assess the potential impact of violating Kirchhoff's law on estimates of physical parameters such as diameter and IR albedo, with an emphasis on NEOWISE results. The NEOWISE papers use ten different models, applied to 12 different combinations of WISE data bands, in 47 different combinations. The most prevalent combinations are simulated and the accuracy of diameter estimates is found to be depend critically on the model and data band combination. In the best case of full thermal modeling of all four band the errors in an idealized model the 1σ (68.27%) confidence interval is -5% to +6%, but this combination is just 1.9% of NEOWISE results. Other combinations representing 42% of the NEOWISE results have about twice the CI at -10% to +12%, before accounting for errors due to irregular shape or other real world effects that are not simulated. The model and data band combinations found for the majority of NEOWISE results have much larger systematic and random errors. Kirchhoff's law violation by NEOWISE models leads to errors in estimation accuracy that are strongest for asteroids with W1, W2 band emissivity ɛ12 in both the lowest (0.605 ≤ɛ12 ≤ 0 . 780), and highest decile (0.969 ≤ɛ12 ≤ 0 . 988), corresponding to the highest and lowest deciles of near-IR albedo pIR. Systematic accuracy error between deciles ranges from a low of 5% to as much as 45%, and there are also differences in the random errors. Kirchhoff's law effects also produce large errors in NEOWISE estimates of pIR, particularly for high

  6. Response to comment on paper examining the feasibility of changing New York state's energy infrastructure to one derived from wind, water, and sunlight

    International Nuclear Information System (INIS)

    Jacobson, Mark Z.; Howarth, Robert W.; Delucchi, Mark A.; Scobie, Stan R.; Barth, Jannette M.; Dvorak, Michael J.; Klevze, Megan; Katkhuda, Hind; Miranda, Brian; Chowdhury, Navid A.; Jones, Rick; Plano, Larsen; Ingraffea, Anthony R.

    2013-01-01

    Jacobson et al. (2013, hereinafter J13), presented the technical and economic feasibility of converting New York States' all-purpose energy infrastructure (electricity, transportation, heating/cooling, industry) to one powered by wind, water, and sunlight (WWS) producing electricity and electrolytic hydrogen. Gilbraith et al. (2013) question several aspects of our approach. Unfortunately, Gilbraith et al. inaccurately portray what we stated and referenced and ignore many recent supporting studies. They also refer to previous misplaced critiques of our earlier global WWS study but fail to reference the responses to those critiques, Delucchi and Jacobson (2011b) and Jacobson and Delucchi (2013). We fully stand by the conclusions of both the previous and present studies. - Highlights: • New York State's all-purpose energy can be derived from wind, water, and sunlight. • The main limitations are social and political, not technical or economic. • This response to commentary reaffirms these conclusions

  7. Converting sunlight into audible sound by means of the photoacoustic effect: The Heliophone.

    Science.gov (United States)

    Roozen, N B; Glorieux, C; Liu, L; Rychtáriková, M; Van der Donck, T; Jacobs, A

    2016-09-01

    One hundred and thirty-five years after Alexander Graham Bell and his assistant Charles Sumner Tainter explored the photoacoustic effect, and about 40 years after Rosencwaig and Gersho modeled the effect in a photoacoustic cell configuration, the phenomenon is revisited in a "Heliophone" device that converts sunlight into sound. The light is focused on a carbon blackened copper coated Kapton foil in an acoustic cell by means of a compound parabolic collimator, and its intensity is modulated by a mechanical chopper. A horn is employed to make the sound audible without electronic amplification. The description of the photoacoustic effect that was introduced by Rosencwaig and Gersho is extended to a cell-horn configuration, in which the periodically heated air above the foil acts as an oscillating piston, driving acoustic waves in the horn. The pressure in the cavity-horn assembly is calculated by considering the air layer piston as an equivalent volume velocity source. The importance of the carbon black (soot) layer to enhance light absorption, but above all to enhance the photothermal excitation efficiency, is elucidated by means of an experimentally supported physical model.

  8. The economic feasibility of producing hydrogen from sunlight and wind

    International Nuclear Information System (INIS)

    Mann, M. K.; Spath, P. L.; Watt, A. S.

    1999-01-01

    The feasibility of utilizing photoelectrochemical and electrolytical technologies to convert energy from the sun and wind into hydrogen was studied. In exploring opportunities to reduce the cost of hydrogen production through interaction with the electric utility grid, it was found that direct photoelectrochemical (PEC) conversion of sunlight has the economic potential to compete with direct photovoltaic/electrolysis, notwithstanding the significant stability and efficiency issues that are still awaiting solution. Interaction with the grid, while maximizing electrolizer use, makes a significant impact on the economics of producing hydrogen by photovoltaic/electrolysis, making wind-based systems also more economical. Electrolysis was found to be the optimal solution only with electricity from renewable sources or with less expensive non-peak electricity. On the other hand, the delivered cost of hydrogen was found to the lowest when electricity production was decoupled from the hydrogen production operation. Decoupled hydrogen production also has an additional benefit, i.e. it produces the hydrogen where it is needed, therefore it mitigates the need for various storage and distribution costs. 6 refs., 4 tabs., 2 figs

  9. Theory of direct sunlight transmission through orthogonal screen cells

    International Nuclear Information System (INIS)

    Aljofi, E.K.

    2006-01-01

    The Purpose of this paper is to investigate the feasibility of using the Rawshan screens to control high light intensity and to avoid excessive solar radiation penetrating inside the building interior. The exploration of the environmental characteristics of this device indicates an ideal solution to utilize available daylight in the arid atmosphere, reduces energy consumption due to the us of artificial light and ensures the continuity of the traditional architecture and the country heritage. A systematic analysis of direct sunlight transmission has been explored using a mathematical approach. The study intends to construct a predictive tool for the architects through which different specifications of the Rawshan screens were identified as far as direct beam of light concerned. The predictive tool was set-up to investigate various parameters of the screen such as the screen configurations, the aperture configurations, the change in orientation and the effect of the sky condition. The analysis of light transmission through the screen were set-up for orthogonal shapes

  10. Evaluation of the effects of repeated hand washing, sunlight, smoke and dirt on the persistence of deltamethrin on insecticide-treated nets.

    Science.gov (United States)

    Kayedi, M H; Lines, J D; Haghdoost, A A; Vatandoost, M H; Rassi, Y; Khamisabady, K

    2008-08-01

    Field studies were carried out in Iran to evaluate the effect of various factors (washing, sun, smoke, dust and dirt) on the residual insecticidal activity of PermaNet (a brand of long-lasting insecticidal net), and on nets conventionally treated with deltamethrin (K-O Tab), using bioassay tests. Thirty-two nets were washed five or 15 times, and eight nets were not washed at all. Nets were washed vigorously in cold tap water (17 degrees C, pH 8.9) with a detergent. Hand rubbing continued for 3min. After washing, some nets were exposed to dense smoke from a dung-hay fire for 3min and were also left exposed to the dusty wind between washes. One group of nets was exposed to the sunlight for the full 3-d interval between washes; another was exposed to sunlight for just 3h after each wash; two other groups were kept in the shade. There was a significantly greater loss of activity in nets exposed to the sun throughout the 3-d interval between washes: that is, for a total of 15 to 45 d. However, short sunlight exposure (maximum 3h between washes) during drying did not have any effect. We did not find any significant effect of exposure to dirt, dust and smoke after washing. It is concluded that the effect of sun is much smaller than that of washing, and that drying nets for a few hours in the sun is not harmful.

  11. 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

  12. 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.

  13. Towards a Better Understanding of the Molecular Mechanisms Involved in Sunlight-Induced Melanoma

    Directory of Open Access Journals (Sweden)

    Williams Mandy

    2005-01-01

    Full Text Available Although much less prevalent than its nonmelanoma skin cancer counterparts, cutaneous malignant melanoma (CMM is the most lethal human skin cancer. Epidemiological and biological studies have established a strong link between lifetime exposure to ultraviolet (UV light, particularly sunburn in childhood, and the development of melanoma. However, the specific molecular targets of this environmental carcinogen are not known. Data obtained from genetic and molecular studies over the last few years have identified the INK4a/ARF locus as the “gatekeeper” melanoma suppressor, encoding two tumour suppressor proteins in human, p16 INK4a and p14 ARF . Recent developments in molecular biotechnology and research using laboratory animals have made a significant gene breakthrough identifying the components of the p16 INK4a /Rb pathway as the principal and rate-limiting targets of UV radiation actions in melanoma formation. This review summarizes the current knowledge of the molecular mechanisms involved in melanoma development and its relationship to sunlight UV radiation.

  14. Sunlight and Vitamin D: The Bone and Cancer Connections (invited paper)

    International Nuclear Information System (INIS)

    Holick, M.F.

    2000-01-01

    Vitamin D plays an essential role for calcium metabolism and bone health. It has been estimated that 90 to 95% of our vitamin D requirement comes from casual exposure to sunlight. There is a wide variety of factors that strongly influence the cutaneous production of vitamin D. These include melanin pigmentation, latitude, time of day, sunscreen use, and aging. There is an association with increased risk and mortality to breast, colon, and prostrate cancer. There is evidence that 25-hydroxyvitamin D, the major circulating form of vitamin D, is directly metabolised in prostate, breast, colon, and skin cells to its active form 1,25-dihydroxyvitamin D. 1,25-Dihydroxyvitamin D 3 has the capacity to regulate cell proliferation and differentiation. Therefore, it may be that an increase in the cutaneous synthesis of vitamin D results in the increase in the production of 1,25(OH) 2 D in tissues not related to calcium metabolism that results in a decrease in malignancy. (author)

  15. 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

  16. Molecular cloning, characterization and expression of heat shock protein 70 gene from the oyster Crassostrea hongkongensis responding to thermal stress and exposure of Cu(2+) and malachite green.

    Science.gov (United States)

    Zhang, Zhanhui; Zhang, Qizhong

    2012-04-15

    Heat shock protein 70 (HSP70) acts mostly as a molecular chaperone and plays a key role in the process of protecting cells by facilitating the folding of nascent peptides and the cellular stress response. The cDNA of the oyster Crassostrea hongkongensis hsp70 (designated chhsp70) was cloned with the techniques of homological cloning and rapid amplification of cDNA ends (RACE). The full-length chhsp70 cDNA was 2251bp, consisting of a 130bp 5'-UTR, 216bp 3'-UTR with a canonical polyadenylation signal sequence AATAAA and a poly (A) tail, and an open reading frame of 1905bp, which encoded a polypeptide of 634 amino acids. Three classical HSP signature motifs were detected in ChHSP70, i.e., DLGTT-S-V, IFDLGGGTFDVSIL and VVLVGGSTRIPKIQK. BLAST analysis revealed that the ChHSP70 shared high identity with other bivalve HSP70. The phylogenetic analysis indicated that the ChHSP70 was a member of the HSP70 family. The chhsp70 mRNA transcripts were quantified by fluorescent real time RT-PCR under both unstressed and stressed conditions, i. e., heat shock and exposure to Cu(2+) and malachite green. Basal expression level was similar in mantle, gill, digestive gland, and heart, but higher in muscle than that in the others. A similar trend showed that the chhsp70 mRNA expression significantly increased at 3-6h, then dropped and returned to control level at 24h in the five tissues and organs mentioned above after heat shock. A clearly time-dependent expression pattern of chhsp70 mRNA in digestive gland and gill of the oyster was observed after exposure of Cu(2+) and malachite green. In the two tissues, the chhsp70 mRNA level reached the maximum at 6h after malachite green exposure and on day 4 after Cu(2+) exposure, and then decreased progressively to the control level. The results indicated that ChHSP70 of the oyster is an inducible protein, and plays an important role in response to the Cu(2+) and malachite green polluted stress, so chhsp70 might be used as a potential molecular

  17. The exposure of CIGS solar cells to different electrical biases in a damp-heat illumination environment

    NARCIS (Netherlands)

    Theelen, M.; Steijvers, H.; Bakker, K.; Vink, J.; Mortazavi, S.; Mulder, A.; Barreau, N.; Roosen, D.; Haverkamp, E.

    2016-01-01

    Two hybrid degradation setups, allowing exposure of solar cells and modules to elevated temperatures and humidity as well as illumination have been built. CIGS solar cells were placed in the degradation setups, allowing real time monitoring of their electrical properties. Under open circuit

  18. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Directory of Open Access Journals (Sweden)

    Marie Ragon

    Full Text Available BACKGROUND: The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta and ascomycete fungi (Ascomycota dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. CONCLUSIONS/SIGNIFICANCE: Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in

  19. Sunlight-Exposed Biofilm Microbial Communities Are Naturally Resistant to Chernobyl Ionizing-Radiation Levels

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    Background The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. Methodology/Principal Findings To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Conclusions/Significance Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general

  20. Indoor exposure to particles emitted by biomass-burning heating systems and evaluation of dose and lung cancer risk received by population.

    Science.gov (United States)

    Stabile, L; Buonanno, G; Avino, P; Frattolillo, A; Guerriero, E

    2018-04-01

    Homes represent a critical microenvironment in terms of air quality due to the proximity to main particle sources and the lack of proper ventilation systems. Biomass-fed heating systems are still extensively used worldwide, then likely emitting a significant amount of particles in indoor environments. Nonetheless, research on biomass emissions are limited to their effects on outdoor air quality then not properly investigating the emission in indoor environments. To this purpose, the present paper aims to evaluate the exposure to different airborne particle metrics (including both sub- and super-micron particles) and attached carcinogenic compounds in dwellings where three different heating systems were used: open fireplaces, closed fireplaces and pellet stoves. Measurements in terms of particle number, lung-deposited surface area, and PM fraction concentrations were measured during the biomass combustion activities, moreover, PM 10 samples were collected and chemically analyzed to obtain mass fractions of carcinogenic compounds attached onto particles. Airborne particle doses received by people exposed in such environments were evaluated as well as their excess lung cancer risk. Most probable surface area extra-doses received by people exposed to open fireplaces on hourly basis (56 mm 2  h -1 ) resulted one order of magnitude larger than those experienced for exposure to closed fireplaces and pellet stoves. Lifetime extra risk of Italian people exposed to the heating systems under investigation were larger than the acceptable lifetime risk (10 -5 ): in particular, the risk due to the open fireplace (8.8 × 10 -3 ) was non-negligible when compared to the overall lung cancer risk of typical Italian population. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Analysis of the WCLL European demo blanket concept in terms of activation and decay heat after exposure to neutron irradiation

    OpenAIRE

    Stankunas Gediminas; Tidikas Andrius

    2017-01-01

    This comparative paper describes the activation and decay heat calculations for water-cooled lithium-lead performed part of the EURO fusion WPSAE programme and specifications in comparison to other European DEMO blanket concepts on the basis of using a three-dimensional neutronics calculation model. Results are provided for a range of decay times of interest for maintenance activities, safety and waste management assessments. The study revealed that water-c...

  2. Daytime Cognitive Performance in Response to Sunlight or Fluorescent Light Controlling for Sleep Duration

    Science.gov (United States)

    Ramos, Jhanic; Zamos, Adela; Rao, Rohit; Flynn-Evans, Erin

    2015-01-01

    Light is the primary synchronizer of the human circadian rhythm and also has acute alerting effects. Our study involves and comparing the alertness, performance and sleep of participants in the NASA Ames Sustainability Base, which uses sunlight as its primary light source, to in a traditional office building which uses overhead florescent lighting and varying exposure to natural light. The purpose of this study is to determine whether the use of natural lighting as a primary light source improves daytime cognitive function and promotes nighttime sleep. Participants from the Sustainability Base will be matched by gender and age to individuals working in other NASA buildings. In a prior study we found no differences in performance between those working in the Sustainability Base and those working in other buildings. Unexpectedly, we found that the average sleep duration among participants in both buildings was short, which likely obscured our ability to detect a difference the effect of light exposure on alertness. Given that such sleep deprivation has negative effects on cognitive performance, in this iteration of the study we are asking the participants to maintain a regular schedule with eight hours in bed each night in order to control for the effect of self-selected sleep restriction. Over the course of one week, we will ask the participants to wear actiwatches continuously, complete a psychomotor vigilance task (PVT) and digit symbol substitution task (DSST) three times per day, and keep daily sleepwork diaries. We hope that this study will provide data to support the idea that natural lighting and green architectural design are optimal to enhance healthy nighttime sleep patterns and daytime cognitive performance.

  3. 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 PM 2.5 105.7μg/m 3 ; 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

  4. Elevated expression of proto-oncogenes accompany enhanced induction of heat-shock genes after exposure of rat embryos in utero to ionizing irradiation

    International Nuclear Information System (INIS)

    Higo, H.; Lee, J.Y.; Satow, Y.; Higo, K.

    1989-01-01

    We have recently found that the effects of exposing rat embryos in utero to teratogens capable of producing cardiac anomalies were expressed later as enhanced induction of heat-shock proteins (hsp70 family) when embryonic hearts were cultured in vitro. However, it remained to be determined whether heat-shock proteins are induced in vivo after exposure to teratogens. The heat-shock response in some mammalian systems is known to be accompanied by elevated expression of proto-oncogenes. Using gene-specific DNA probes, we examined the levels of the expression (transcription) of heat-shock protein genes and two nuclear proto-oncogenes, c-fos and c-myc, in the embryos removed from irradiated pregnant mother rats 4 or 5 days after the irradiation. We found that the levels of expression in vivo of the hsp70 and c-myc genes in the irradiated embryos increased by approximately twofold as compared with those in the control. The expression in vivo of the c-fos gene was not detected in either the irradiated or non-irradiated embryos. After 0.5-hr incubation in vitro of the embryos, however, the expression of the c-fos gene in the irradiated embryos was highly enhanced whereas the control showed no changes. Although the exact functions of these gene products still remain obscure, the enhanced expression of hsp70 gene(s) and the nuclear proto-oncogenes observed in the present study may reflect repair of intracellular damages and/or regeneration of tissue by compensatory cell proliferation, processes that may disturb the normal program of organogenesis

  5. Surfactant and natural sunlight enhanced Photogalvanic effect of Sudan I dye

    Directory of Open Access Journals (Sweden)

    Pooran Koli

    2017-12-01

    Full Text Available Photogalvanic cells (PG have been extensively studied for solar power and storage at low intensity artificial sunlight. But, PG can be practically significant and applicable in daily life only when they are validated at natural sunlight intensity. Therefore, the present study of photogalvanics of Sudan I-Fructose with efficiency enhancer chemical such as Sodium Lauryl Sulfate (SLS surfactant in alkaline medium has been used to observe their workable feasibility in natural sunlight with investigation for optimal fabrication parameters. The cell has been found workable in natural sunlight with greatly enhanced optimum cell performance compared to that for reported similar cells. The observed optimum cell performance in terms of maximum power, short-circuit current, open-circuit potential, conversion efficiency and storage capacity (as half change time is of the order of 1081.1 μW, 4200 μA, 1048 mV, 13.5%, and 31 min, respectively.

  6. Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters

    OpenAIRE

    Bacosa, Hernando P.; Liu, Zhanfei; Erdner, Deana L.

    2015-01-01

    Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH ...

  7. Numerical characterisation of one-step and three-step solar air heating collectors used for cocoa bean solar drying.

    Science.gov (United States)

    Orbegoso, Elder Mendoza; Saavedra, Rafael; Marcelo, Daniel; La Madrid, Raúl

    2017-12-01

    In the northern coastal and jungle areas of Peru, cocoa beans are dried using artisan methods, such as direct exposure to sunlight. This traditional process is time intensive, leading to a reduction in productivity and, therefore, delays in delivery times. The present study was intended to numerically characterise the thermal behaviour of three configurations of solar air heating collectors in order to determine which demonstrated the best thermal performance under several controlled operating conditions. For this purpose, a computational fluid dynamics model was developed to describe the simultaneous convective and radiative heat transfer phenomena under several operation conditions. The constructed computational fluid dynamics model was firstly validated through comparison with the data measurements of a one-step solar air heating collector. We then simulated two further three-step solar air heating collectors in order to identify which demonstrated the best thermal performance in terms of outlet air temperature and thermal efficiency. The numerical results show that under the same solar irradiation area of exposition and operating conditions, the three-step solar air heating collector with the collector plate mounted between the second and third channels was 67% more thermally efficient compared to the one-step solar air heating collector. This is because the air exposition with the surface of the collector plate for the three-step solar air heating collector former device was twice than the one-step solar air heating collector. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Marginal and internal fit of heat pressed versus CAD/CAM fabricated all-ceramic onlays after exposure to thermo-mechanical fatigue

    Science.gov (United States)

    Guess, Petra C.; Vagopoulou, Thaleia; Zhang, Yu; Wolkewitz, Martin; Strub, Joerg R.

    2015-01-01

    Objectives The aim of the study was to evaluate the marginal and internal fit of heat-pressed and CAD/CAM fabricated all-ceramic onlays before and after luting as well as after thermo-mechanical fatigue. Materials and Methods Seventy-two caries-free, extracted human mandibular molars were randomly divided into three groups (n=24/group). All teeth received an onlay preparation with a mesio-occlusal-distal inlay cavity and an occlusal reduction of all cusps. Teeth were restored with heat-pressed IPS-e.max-Press* (IP, *Ivoclar-Vivadent) and Vita-PM9 (VP, Vita-Zahnfabrik) as well as CAD/CAM fabricated IPS-e.max-CAD* (IC, Cerec 3D/InLab/Sirona) all-ceramic materials. After cementation with a dual-polymerizing resin cement (VariolinkII*), all restorations were subjected to mouth-motion fatigue (98N, 1.2 million cycles; 5°C/55°C). Marginal fit discrepancies were examined on epoxy replicas before and after luting as well as after fatigue at 200x magnification. Internal fit was evaluated by multiple sectioning technique. For the statistical analysis, a linear model was fitted with accounting for repeated measurements. Results Adhesive cementation of onlays resulted in significantly increased marginal gap values in all groups, whereas thermo-mechanical fatigue had no effect. Marginal gap values of all test groups were equal after fatigue exposure. Internal discrepancies of CAD/CAM fabricated restorations were significantly higher than both press manufactured onlays. Conclusions Mean marginal gap values of the investigated onlays before and after luting as well as after fatigue were within the clinically acceptable range. Marginal fit was not affected by the investigated heat-press versus CAD/CAM fabrication technique. Press fabrication resulted in a superior internal fit of onlays as compared to the CAD/CAM technique. Clinical Relevance Clinical requirements of 100 μm for marginal fit were fulfilled by the heat-press as well as by the CAD/CAM fabricated all-ceramic onlays

  9. 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.)

  10. Matching demand with supply at low cost in 139 countries among 20 world regions with 100% intermittent wind, water, and sunlight (WWS) for all purposes

    DEFF Research Database (Denmark)

    Jacobson, Mark Z.; Delucchi, Mark A.; Cameron, Mary A.

    2018-01-01

    Matching electricity, heat, and cold demand with supply at low cost is the greatest concern facing countries seeking to provide their all-purpose energy with 100% clean, renewable wind, water, and sunlight (WWS). Implementing WWS worldwide could eliminate 4–7 million annual air pollution deaths......, first slow then reverse global warming, and provide energy sustainably. This study derives zero-load-loss technical solutions to matching demand with 100% WWS supply; heat, cold, and electricity storage; hydrogen production; assumed all-distance transmission; and demand response for 20 world regions...... are similar, WWS requires ∼42.5% less energy in a base case and ∼57.9% less in a heat-pump case so may reduce capital and consumer costs significantly. Further, WWS social (energy + health + climate) costs per unit energy are one-fourth BAU's. By reducing water vapor, the wind turbines proposed may rapidly...

  11. Direct sunlight facility for testing and research in HCPV

    International Nuclear Information System (INIS)

    Sciortino, Luisa; Agnello, Simonpietro; Bonsignore, Gaetano; Cannas, Marco; Gelardi, Franco Mario; Napoli, Gianluca; Spallino, Luisa; Barbera, Marco; Buscemi, Alessandro; Montagnino, Fabio Maria; Paredes, Filippo; Candia, Roberto; Collura, Alfonso; Di Cicca, Gaspare; Cicero, Ugo Lo; Varisco, Salvo

    2014-01-01

    A facility for testing different components for HCPV application has been developed in the framework of 'Fotovoltaico ad Alta Efficienza' (FAE) project funded by the Sicilian Regional Authority (PO FESR Sicilia 2007/2013 4.1.1.1). The testing facility is equipped with an heliostat providing a wide solar beam inside the lab, an optical bench for mounting and aligning the HCPV components, electronic equipments to characterize the I-V curves of multijunction cells operated up to 2000 suns, a system to circulate a fluid in the heat sink at controlled temperature and flow-rate, a data logging system with sensors to measure temperatures in several locations and fluid pressures at the inlet and outlet of the heat sink, and a climatic chamber with large test volume to test assembled HCPV modules

  12. Pulmonary heat shock protein expression after exposure to a metabolically activated Clara cell toxicant: relationship to protein adduct formation

    International Nuclear Information System (INIS)

    Williams, Kurt J.; Cruikshank, Michael K.; Plopper, Charles G.

    2003-01-01

    Heat shock proteins/stress proteins (Hsps) participate in regulation of protein synthesis and degradation and serve as general cytoprotectants, yet their role in lethal Clara cell injury is not clear. To define the pattern of Hsp expression in acute lethal Clara cell injury, mice were treated with the Clara cell-specific toxicant naphthalene (NA), and patterns of expression compared to electrophilic protein adduction and previously established organellar degradation and gluathione (GSH) depletion. In sites of lethal injury (distal bronchiole), prior to organellar degradation (1 h post-NA), protein adduction is detectable and ubiquitin, Hsp 25, Hsp 72, and heme-oxygenase 1 (HO-1) are increased. Maximal Hsp expression, protein adduction, and GSH depletion occur simultaneous (by 2-3 h) with early organelle disruption. Hsp expression is higher later (6-24 h), only in exfoliating cells. In airway sites (proximal bronchiole) with nonlethal Clara cell injury elevation of Hsp 25, 72, and HO-1 expression follows significant GSH depletion (greater than 50% 2 h post-NA). This data build upon our previous studies and we conclude that (1) in lethal (terminal bronchiole) and nonlethal (proximal bronchiole) Clara cell injury, Hsp induction is associated with the loss of GSH and increased protein adduction, and (2) in these same sites, organelle disruption is not a prerequisite for Hsp induction

  13. 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.

  14. Can the ionizing radiation and sunlight be harmful to health?

    International Nuclear Information System (INIS)

    Pesmen, Curt

    2008-01-01

    We're all exposed to radiation sources: the sun, X-rays, mammograms, CT scans, dental exams, even soil and we're just now finding out whether those rays, combined, are dangerous. Scientists are still figuring that out and they tend to disagree about the risks. But they recently found worrying signs that radiation exposure is on the rise, thanks largely to the popularity of high-tech medical exams such as CT scans. So it's wise to limit exposure as possible. The odds of developing cancer from radiation exposure are very small, but risks do rise the younger a person is radiated. There is a radiation footprint for every person. Some scientists do not believe any level of radiation is necessarily safe. At some time in life anyone will need a radiation-based medical treatment or diagnostic test. Radiation therapy may be the best way to shrink a cancer or save a life. A recent study warned that up to one-third of all CT scans may be medically unnecessary. Frequent flying theoretically ups cancer risks. After all, seven miles above sea level, there is much less atmosphere to absorb radiation from the sun.

  15. Induction of heat shock proteins (hsp70) in the zebra mussel (Dreissena polymorpha) following exposure to platinum group metals (platinum, palladium and rhodium): Comparison with lead and cadmium exposures

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Christoph [Zoologisches Institut I-Oekologie, Universitaet Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D-76131 Karlsruhe (Germany); Zimmermann, Sonja [Zoologisches Institut I-Oekologie, Universitaet Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D-76131 Karlsruhe (Germany); Sures, Bernd [Zoologisches Institut I-Oekologie, Universitaet Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D-76131 Karlsruhe (Germany)]. E-mail: dc11@rz.uni-karlsruhe.de

    2005-10-05

    An increasing number of papers concentrate on the availability and uptake of platinum group elements (PGE) by different organisms. These metals are discharged into the environment from different anthropogenic sources, such as automobile catalytic converters, hospitals and other medical institutions. As the effects of these precious metals on organisms remain unclear, the induction of heat shock proteins (hsp70) in zebra mussels (Dreissena polymorpha) following exposure to soluble salts of platinum, palladium and rhodium was compared with the hsp70 induction in mussels following exposure to cadmium and lead. Mussels were sampled weekly during a period of 10 weeks and analyzed for their metal concentration and their hsp70 level. Highest metal uptake was found for Cd, followed by Pt, Pb and Pd. Rh demonstrated the lowest uptake rate. A clear time-dependent increase of hsp70 levels occurred in all exposed mussels. Concentrations of hsp70 started to rise between days 18 and 25, except for the Pt-exposed group, where the initial increase was between days 25 and 32. All groups reached maximal hsp70 concentrations at day 39. Subsequently, hsp70 levels decreased to initial levels for the remaining exposure period. Threshold metal levels for the hsp70 induction varied among the metals and increased in the order: Rh < Pd {<=} Pb < Pt < Cd. Highest hsp70 values were found for mussels exposed to Pd, with a 25-fold higher level than in the controls, followed by Pt- and Rh-exposed mussels, which showed a 19-fold increase. The hsp70 levels of the mussels exposed to Cd and Pb were much lower, showing 6- and 12-fold higher values than the control, respectively. The clear induction of hsp70 due to exposure to Pt, Pd and Rh gives evidence for strong cellular effects of these metals, especially, when compared with lead and cadmium. Among the metals tested, Pd seems to have the highest potential as inducer for hsp70 production due to its low threshold level in combination with the

  16. Induction of heat shock proteins (hsp70) in the zebra mussel (Dreissena polymorpha) following exposure to platinum group metals (platinum, palladium and rhodium): Comparison with lead and cadmium exposures

    International Nuclear Information System (INIS)

    Singer, Christoph; Zimmermann, Sonja; Sures, Bernd

    2005-01-01

    An increasing number of papers concentrate on the availability and uptake of platinum group elements (PGE) by different organisms. These metals are discharged into the environment from different anthropogenic sources, such as automobile catalytic converters, hospitals and other medical institutions. As the effects of these precious metals on organisms remain unclear, the induction of heat shock proteins (hsp70) in zebra mussels (Dreissena polymorpha) following exposure to soluble salts of platinum, palladium and rhodium was compared with the hsp70 induction in mussels following exposure to cadmium and lead. Mussels were sampled weekly during a period of 10 weeks and analyzed for their metal concentration and their hsp70 level. Highest metal uptake was found for Cd, followed by Pt, Pb and Pd. Rh demonstrated the lowest uptake rate. A clear time-dependent increase of hsp70 levels occurred in all exposed mussels. Concentrations of hsp70 started to rise between days 18 and 25, except for the Pt-exposed group, where the initial increase was between days 25 and 32. All groups reached maximal hsp70 concentrations at day 39. Subsequently, hsp70 levels decreased to initial levels for the remaining exposure period. Threshold metal levels for the hsp70 induction varied among the metals and increased in the order: Rh < Pd ≤ Pb < Pt < Cd. Highest hsp70 values were found for mussels exposed to Pd, with a 25-fold higher level than in the controls, followed by Pt- and Rh-exposed mussels, which showed a 19-fold increase. The hsp70 levels of the mussels exposed to Cd and Pb were much lower, showing 6- and 12-fold higher values than the control, respectively. The clear induction of hsp70 due to exposure to Pt, Pd and Rh gives evidence for strong cellular effects of these metals, especially, when compared with lead and cadmium. Among the metals tested, Pd seems to have the highest potential as inducer for hsp70 production due to its low threshold level in combination with the

  17. Thermophysiological adaptations to passive mild heat acclimation

    NARCIS (Netherlands)

    Pallubinsky, H; Schellen, L; Kingma, B R M; Dautzenberg, B; van Baak, M A; van Marken Lichtenbelt, W D

    Passive mild heat acclimation (PMHA) reflects realistic temperature challenges encountered in everyday life. Active heat acclimation, combining heat exposure and exercise, influences several important thermophysiological parameters; for example, it decreases core temperature and enhances heat

  18. Influence of manure age and sunlight on the community structure of cattle fecal bacteria as revealed by Illumina sequencing

    Science.gov (United States)

    Wong, K.; Shaw, T. I.; Oladeinde, A.; Molina, M.

    2013-12-01

    Fecal pollution of environmental waters is a major concern for the general public because exposure to fecal-associated pathogens can have severe impacts on human health. Stream and river impairment due to fecal pollution is largely the result of agricultural activities in the United States. In the last few years, numerous metagenomic studies utilized next generation sequencing to develop microbial community profiles by massively sequencing the 16sRNA hypervariable region. This technology supports the application of water quality assessment such as pathogen detection and fecal source tracking. The bacteria communities of samples in these studies were determined when they were freshly collected; therefore, little is known about how feces age or how environmental stress influences the microbial ecology of fecal materials. In this study we monitored bacteria community changes in cattle feces for 57 days after excretion (day 0, 2, 4 8, 15, 22, 29, 43, 57) by sequencing the 16s variable region 4, using Illumnia MiSeq. Twelve cattle feces were studied; half of the samples were directly exposed to sunlight (unshaded) and half were shaded. Results indicate that the relative abundance (RA) profile in both shaded and unshaded samples rapidly changed from day 0 to 15, but stabilized from day 22 to 57. Firmcutes were the most abundant phylum (~40%) at day 0, but were reduced to rarefaction curve analysis, richness of bacteria diversity in feces decreased as time progressed. Some pathogens such as Campylobacter were detected only at the beginning, meaning they substantially decayed during the course of our study. Overall, this study indicated: (1) sunlight can influence the community structure and (2) after excretion the fecal bacteria diversity can be significantly changed over time. Future studies should therefore use not only the microbial signature of fresh but also moderately aged fecal samples to develop more accurate community profiles for fecal source tracking.

  19. 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

  20. Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

    2011-01-01

    An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly...... uses cow dung, a reservoir of this organism. Hence, a experiment was set up to study the duration of survival of pathogenic E. coli under sunlight and darkness. Eight pathogenic E. coli isolates from clinical (EPEC, ETEC, EHEC, EAEC), veterinary (CTE3, CTE4) and environmental sources (ASHE3, Rao II......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E...

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

    International Nuclear Information System (INIS)

    Planello, R.; Martinez-Guitarte, J.L.; Morcillo, G.

    2010-01-01

    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 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.

  2. 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.

  3. 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; Kwak, Ihn-Sil

    2014-01-01

    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. 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. 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. 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.

  4. Reduction of energy essential to human life by 70%. Environment-friendly residence `ED-1` utilizing the sunlight effectively; Seikatsu ni hitsuyona energy no 70% sakugen. Taiyoko riyo no kankyo kyosei jutaku ED-1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This paper presents the environment-friendly residence `ED-1` utilizing the sunlight effectively. ED-1 of 97m{sup 2} in first floor area and 81m{sup 2} in second one has, on its roof, the photovoltaic power generation system, the solar hot water collector which supplies hot water by circulating heated antifreezing solution into a hot storage tank, and the solar hot wind collector which largely contributes to energy saving together with a hot room named an S unit on the first floor. The small S unit faced toward the south adjacent to a dining room is made of timber and thermal insulation glass. The S unit stores heat in a floor by taking the sunlight into a room in winter, while enhances a heating effect by discharging stored heat in nighttime. In some cases, duct circulation of heated wind is possible. Solar radiation of 90% can be removed by outside glass fiber screen of the S unit together with double glazing coated by special metal film. Roof material is superior in heat insulation, air tightness and energy saving, while floor material in sound insulation and heat storage. The target for reducing energy essential to human life by 70% was thus nearly achieved. 1 fig.

  5. Evidence for three types of x-ray damage repair in yeast and sensitivity of totally repair deficient strains to sunlight

    International Nuclear Information System (INIS)

    Game, J.C.; Schild, D.; Mortimer, R.K.

    1987-01-01

    Mutants of yeast that confer sensitivity to x-rays are known to fall into two epistasis groups, called here the RAD51 and RAD18 groups, which are each thought to control a different type of x-ray repair. They examine here the role of genes in a third repair pathways in x-ray repair. RAD1 and RAD3 are known to be important in the repair of pyrimidine dimers after uv-irradiation. They find that these genes can also play an important role in x-ray repair, but that this role is only exposed when both the other pathways of x-ray repair are blocked. Double mutants blocked in the RAD51 and RAD18 pathways are significantly less x-ray sensitive than triple mutants blocked in these pathways but also mutant in either the RAD1 or RAD3 genes. In a related experiment, they tested the importance of DNA repair in nature by determining the sensitivity to natural unfiltered sunlight of a strain lacking all known DNA repair pathways. They constructed a quadruple mutant strain containing RAD1-1, RAD18-2, RAD51-1 and PHR1-1. The latter mutation blocks the cell's ability to photoreactivate uv damage. They found that this strain was so sensitive to sunlight that less than three seconds' exposure would cause an average of one lethal hit per cell, and survival was less than 2% after ten seconds' exposure. Wild type yeast at sea level showed no killing after thirty minutes. the quadruple mutant is approximately one thousand times more sensitive to sunlight than the related wild type

  6. Roles of sunlight and natural ventilation for controlling infection: historical and current perspectives.

    Science.gov (United States)

    Hobday, R A; Dancer, S J

    2013-08-01

    Infections caught in buildings are a major global cause of sickness and mortality. Understanding how infections spread is pivotal to public health yet current knowledge of indoor transmission remains poor. To review the roles of natural ventilation and sunlight for controlling infection within healthcare environments. Comprehensive literature search was performed, using electronic and library databases to retrieve English language papers combining infection; risk; pathogen; and mention of ventilation; fresh air; and sunlight. Foreign language articles with English translation were included, with no limit imposed on publication date. In the past, hospitals were designed with south-facing glazing, cross-ventilation and high ceilings because fresh air and sunlight were thought to reduce infection risk. Historical and recent studies suggest that natural ventilation offers protection from transmission of airborne pathogens. Particle size, dispersal characteristics and transmission risk require more work to justify infection control practices concerning airborne pathogens. Sunlight boosts resistance to infection, with older studies suggesting potential roles for surface decontamination. Current knowledge of indoor transmission of pathogens is inadequate, partly due to lack of agreed definitions for particle types and mechanisms of spread. There is recent evidence to support historical data on the effects of natural ventilation but virtually none for sunlight. Modern practice of designing healthcare buildings for comfort favours pathogen persistence. As the number of effective antimicrobial agents declines, further work is required to clarify absolute risks from airborne pathogens along with any potential benefits from additional fresh air and sunlight. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  7. In utero exposure to heat stress during late gestation has prolonged effects on the activity patterns and growth of dairy calves.

    Science.gov (United States)

    Laporta, J; Fabris, T F; Skibiel, A L; Powell, J L; Hayen, M J; Horvath, K; Miller-Cushon, E K; Dahl, G E

    2017-04-01

    Exposure to heat stress during late gestation exerts negative carryover effects on the postnatal performance of the calf. In this study, we evaluated the health, growth, and activity patterns of calves born to cows exposed to heat stress (HT, provided only shade, n = 31) or cooling (CL, fans, soakers, and shade, n = 29) during late gestation (∼46 d, maternal dry period). Calves' body weight, rectal temperature, suckling reflex, and movement scores were recorded at birth, and calves were fed 6.6 L of maternal colostrum in 2 meals. Blood samples were collected at birth (before feeding), 24 h after birth, and at d 10 and 28 of age. Calves were housed in individual pens, fed pasteurized milk (6 L/d), and had ad libitum access to grain and water until weaning (49 d). Activity was assessed during the first week of life (wk 1), at weaning (wk 7), and in the first week postweaning (wk 8) using electronic data loggers. Health and body weight were monitored weekly. At birth, calves born to CL cows were heavier (41.9 vs. 39.1 ± 0.8 kg), their temperature was lower (38.9 vs. 39.3 ± 0.08°C), and they were more efficient at absorbing IgG than HT calves. Suckling reflex and movement score at birth were not different between groups, but calves born to CL cows spent more time (50 min/d) standing in the first week of life as a result of longer standing bouts. In wk 7 and 8, calves born to CL cows had less frequent standing bouts than HT heifers, but CL heifers maintained greater total daily standing time (36 min/d) due to longer (7 min/bout) standing bouts. All calves were healthy, but HT heifers tended to have higher (looser) fecal scores on d 10. Heifers born from CL cows gained 0.2 kg/d more from birth to weaning, weighed 4 kg more at weaning, and had greater concentrations of IGF-1 than HT calves, particularly on d 28. In utero heat stress during late gestation had immediate and prolonged effects on passive immunity, growth, and activity patterns in dairy calves. Copyright

  8. Comparison of germicidal activity of sunlight with the response of a sunburning meter

    Energy Technology Data Exchange (ETDEWEB)

    Billen, D; Green, A E.S.

    1975-01-01

    In the present work, we compare germicidal activity of sunlight on strain AB 2480 with the irradiance of sunlight as measured with a Sunburning Ultraviolet Meter (manufactured by the Skin and Cancer Hospital, Temple University Health Sciences Center, Philadelphia, Pennsylvania). This instrument, an adaptation by Berger of one developed by Robertson (1972), uses a magnesium tungstate phosphor with a response approximating that of the erythema action spectrum. The light emitted by the phosphor is detected by a phototube which produces a proportional electric current, the signal used in these experiments. (auth)

  9. Errors in short circuit measurements due to spectral mismatch between sunlight and solar simulators

    Science.gov (United States)

    Curtis, H. B.

    1976-01-01

    Errors in short circuit current measurement were calculated for a variety of spectral mismatch conditions. The differences in spectral irradiance between terrestrial sunlight and three types of solar simulator were studied, as well as the differences in spectral response between three types of reference solar cells and various test cells. The simulators considered were a short arc xenon lamp AMO sunlight simulator, an ordinary quartz halogen lamp, and an ELH-type quartz halogen lamp. Three types of solar cells studied were a silicon cell, a cadmium sulfide cell and a gallium arsenide cell.

  10. Proteomic analysis of a model unicellular green alga, Chlamydomonas reinhardtii, during short-term exposure to irradiance stress reveals significant down regulation of several heat-shock proteins.

    Science.gov (United States)

    Mahong, Bancha; Roytrakul, Suttiruk; Phaonaklop, Narumon; Wongratana, Janewit; Yokthongwattana, Kittisak

    2012-03-01

    Oxygenic photosynthetic organisms often suffer from excessive irradiance, which cause harmful effects to the chloroplast proteins and lipids. Photoprotection and the photosystem II repair processes are the mechanisms that plants deploy to counteract the drastic effects from irradiance stress. Although the protective and repair mechanisms seemed to be similar in most plants, many species do confer different level of tolerance toward high light. Such diversity may originate from differences at the molecular level, i.e., perception of the light stress, signal transduction and expression of stress responsive genes. Comprehensive analysis of overall changes in the total pool of proteins in an organism can be performed using a proteomic approach. In this study, we employed 2-DE/LC-MS/MS-based comparative proteomic approach to analyze total proteins of the light sensitive model unicellular green alga Chlamydomonas reinhardtii in response to excessive irradiance. Results showed that among all the differentially expressed proteins, several heat-shock proteins and molecular chaperones were surprisingly down-regulated after 3-6 h of high light exposure. Discussions were made on the possible involvement of such down regulation and the light sensitive nature of this model alga.

  11. Reversible degradation in ITO-containing organic photovoltaics under concentrated sunlight

    NARCIS (Netherlands)

    Galagan, Y.O.; Mescheloff, A.; Veenstra, S.C.; Andriessen, H.A.J.M.; Katz, E.A.

    2015-01-01

    Stabilities of ITO-containing and ITO-free organic solar cells were investigated under simulated AM 1.5G illumination and under concentrated natural sunlight. In both cases ITO-free devices exhibit high stability, while devices containing ITO show degradation of their photovoltaic performance. The

  12. Sunlight-enhanced calcareous deposition on cathodic stainless steel in natural seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Eashwar, M.; SathishKumar, P.; Ravishankar, R.; Subramanian, G.

    In replicate series of experiments in natural seawater, one in full darkness and the other in a 1:1 diurnal cycle with as little as 5 percent of natural solar illumination, sunlight promoted calcareous deposition on cathodic stainless steel surfaces...

  13. Tropospheric nitrogen dioxide inversions based on spectral measurements of scattered sunlight

    NARCIS (Netherlands)

    Vlemmix, T.

    2011-01-01

    This thesis describes the development of inversion methods for tropospheric nitrogen dioxide (NO2), based on ground based observations of scattered sunlight with themulti-axis differential optical absorption spectroscopy (MAX-DOAS) technique. NO2 is an atmospheric trace gas which, when present near

  14. DNA damage by ethylbenzenehydroperoxide formed from carcinogenic ethylbenzene by sunlight irradiation

    International Nuclear Information System (INIS)

    Toda, Chitose; Uchida, Takafumi; Midorikawa, Kaoru; Murata, Mariko; Hiraku, Yusuke; Okamoto, Yoshinori; Ueda, Koji; Kojima, Nakao; Kawanishi, Shosuke

    2003-01-01

    Ethylbenzene, widely used in human life, is a non-mutagenic carcinogen. Sunlight-irradiated ethylbenzene caused DNA damage in the presence of Cu 2+ , but unirradiated ethylbenzene did not. A Cu + -specific chelator bathocuproine inhibited DNA damage and catalase showed a little inhibitory effect. The scopoletin assay revealed that peroxides and H 2 O 2 were formed in ethylbenzene exposed to sunlight. These results suggest that Cu + and alkoxyl radical mainly participate in DNA damage, and H 2 O 2 partially does. When catalase was added, DNA damage at thymine and cytosine was inhibited. Ethylbenzenehydroperoxide, identified by GC/MS analysis, induced the formation of 8-oxo-7,8-dihydro-2 ' -deoxyguanosine and caused DNA damage at consecutive guanines, as observed with cumenehydroperoxide. Equimolar concentrations of H 2 O 2 and acetophenone were produced by the sunlight-irradiation of 1-phenylethanol, a further degraded product of ethylbenzene. These results indicate a novel pathway that oxidative DNA damage induced by the peroxide and H 2 O 2 derived from sunlight-irradiated ethylbenzene may lead to expression of the carcinogenicity

  15. Plant Leaf Imaging using Time of Flight Camera under Sunlight, Shadow and Room Conditions

    DEFF Research Database (Denmark)

    Kazmi, Wajahat; Foix, Sergi; Alenya, Guillem

    2012-01-01

    In this article, we analyze the effects of ambient light on Time of Flight (ToF) depth imaging for a plant's leaf in sunlight, shadow and room conditions. ToF imaging is sensitive to ambient light and we try to find the best possible integration times (IT) for each condition. This is important in...

  16. Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting.

    Science.gov (United States)

    Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

    2010-11-08

    A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

  17. Dose-Response Effect of Sunlight on Vitamin D2 Production in Agaricus bisporus Mushrooms

    DEFF Research Database (Denmark)

    Urbain, Paul; Jakobsen, Jette

    2015-01-01

    The dose response effect of UV-B irradiation from sunlight on vitamin D2 content of sliced Agaricus bisporus (white button mushroom) during the process of sun-drying was investigated.Real-time UV-B and UV-A data were obtained using a high-performance spectroradiometer. During the first hour...

  18. Visual performance with sport-tinted contact lenses in natural sunlight.

    Science.gov (United States)

    Erickson, Graham B; Horn, Fraser C; Barney, Tyler; Pexton, Brett; Baird, Richard Y

    2009-05-01

    The use of tinted and clear contact lenses (CLs) in all aspects of life is becoming a more popular occurrence, particularly in athletic activities. This study broadens previous research regarding performance-tinted CLs and their effects on measures of visual performance. Thirty-three subjects (14 male, 19 female) were fitted with clear B&L Optima 38, 50% visible light transmission Amber and 36% visible light transmission Gray-Green Nike Maxsight CLs in an individualized randomized sequence. Subjects were dark-adapted with welding goggles before testing and in between subtests involving a Bailey-Lovie chart and the Haynes Distance Rock test. The sequence of testing was repeated for each lens modality. The Amber and Gray-Green lenses enabled subjects to recover vision faster in bright sunlight compared with clear lenses. Also, subjects were able to achieve better visual recognition in bright sunlight when compared with clear lenses. Additionally, the lenses allowed the subjects to alternate fixation between a bright and shaded target at a more rapid rate in bright sunlight as compared with clear lenses. Subjects preferred both the Amber and Gray-Green lenses over clear lenses in the bright and shadowed target conditions. The results of the current study show that Maxsight Amber and Gray-Green lenses provide better contrast discrimination in bright sunlight, better contrast discrimination when alternating between bright and shaded target conditions, better speed of visual recovery in bright sunlight, and better overall visual performance in bright and shaded target conditions compared with clear lenses.

  19. Photosynthesis, photoprotection, and growth of shade-tolerant tropical tree seedlings under full sunlight.

    Science.gov (United States)

    Krause, G Heinrich; Winter, Klaus; Matsubara, Shizue; Krause, Barbara; Jahns, Peter; Virgo, Aurelio; Aranda, Jorge; García, Milton

    2012-09-01

    High solar radiation in the tropics is known to cause transient reduction in photosystem II (PSII) efficiency and CO(2) assimilation in sun-exposed leaves, but little is known how these responses affect the actual growth performance of tropical plants. The present study addresses this question. Seedlings of five woody neotropical forest species were cultivated under full sunlight and shaded conditions. In full sunlight, strong photoinhibition of PSII at midday was documented for the late-successional tree species Ormosia macrocalyx and Tetragastris panamensis and the understory/forest gap species, Piper reticulatum. In leaves of O. macrocalyx, PSII inhibition was accompanied by substantial midday depression of net CO(2) assimilation. Leaves of all species had increased pools of violaxanthin-cycle pigments. Other features of photoacclimation, such as increased Chl a/b ratio and contents of lutein, β-carotene and tocopherol varied. High light caused strong increase of tocopherol in leaves of T. panamensis and another late-successional species, Virola surinamensis. O. macrocalyx had low contents of tocopherol and UV-absorbing substances. Under full sunlight, biomass accumulation was not reduced in seedlings of T. panamensis, P. reticulatum, and V. surinamensis, but O. macrocalyx exhibited substantial growth inhibition. In the highly shade-tolerant understory species Psychotria marginata, full sunlight caused strongly reduced growth of most individuals. However, some plants showed relatively high growth rates under full sun approaching those of seedlings at 40 % ambient irradiance. It is concluded that shade-tolerant tropical tree seedlings can achieve efficient photoacclimation and high growth rates in full sunlight.

  20. Burning daylight: balancing vitamin D requirements with sensible sun exposure.

    Science.gov (United States)

    Stalgis-Bilinski, Kellie L; Boyages, John; Salisbury, Elizabeth L; Dunstan, Colin R; Henderson, Stuart I; Talbot, Peter L

    2011-04-04

    To examine the feasibility of balancing sunlight exposure to meet vitamin D requirements with sun protection guidelines. We used standard erythemal dose and Ultraviolet Index (UVI) data for 1 June 1996 to 30 December 2005 for seven Australian cities to estimate duration of sun exposure required for fair-skinned individuals to synthesise 1000 IU (25 µg) of vitamin D, with 11% and 17% body exposure, for each season and hour of the day. Periods were classified according to whether the UVI was 60 min. Duration of sunlight exposure required to achieve 1000 IU of vitamin D synthesis. Duration of sunlight exposure required to synthesise 1000 IU of vitamin D varied by time of day, season and city. Although peak UVI periods are typically promoted as between 10 am and 3 pm, UVI was often ≥ 3 before 10 am or after 3 pm. When the UVI was sunlight exposure while avoiding its damaging effects. Physiological and geographical factors may reduce vitamin D synthesis, and supplementation may be necessary to achieve adequate vitamin D status for individuals at risk of deficiency. ©The Medical Journal of Australia 2011

  1. Water bath hyperthermia is a simple therapy for psoriasis and also stimulates skin tanning in response to sunlight

    Energy Technology Data Exchange (ETDEWEB)

    Boreham, D.R.; Gasmann, H.C.; Mitchel, R.E.J

    1994-07-01

    An eight week trial, involving superficial hyperthermia delivered biweekly via simple water bath immersion, was tested for its ability to clear mild to moderate psoriatic lesions. Seven patients were treated and three cases rapidly improved. In the remaining patients, the treatment frequency was increased to alternate days; two cases improved significantly, one patient showed a partial response, and the fourth had no visible change (this was the only patient taking concurrent drug therapy - etretinate). In addition to resolving psoriatic lesions, water bath hyperthermia also reduced edema (swelling) and relieved pruritus (itching) in all patients, both during the treatment period and for up to several months after lesions had returned. Lesion reappearance occurred within one to three months after the last heat treatment. We retreated one patient and produced a second complete remission. These results indicate that simple repetitive water bath hyperthermia alone is effective in the treatment of psoriatic lesions in heatable locations. An unexpected side effect was enhanced melanin content (tanning) in all areas where hyperthermia treated skin was exposed to sunlight. (author)

  2. PV Thermal systems: PV panels supplying renewable electricity and heat

    NARCIS (Netherlands)

    Helden, van W.G.J.; Zolingen, van R.J.C.; Zondag, H.A.

    2004-01-01

    With PV Thermal panels sunlight is converted into electricity and heat simultaneously. Per unit area the total efficiency of a PVT panel is higher than the sum of the efficiencies of separate PV panels and solar thermal collectors. During the last 20 years research into PVT techniques and concepts

  3. Zinc Oxide-Containing Porous Boron-Carbon-Nitrogen Sheets from Glycine-Nitrate Combustion: Synthesis, Self-Cleaning, and Sunlight-Driven Photocatalytic Activity.

    Science.gov (United States)

    Bharathidasan, T; Mandalam, Aditya; Balasubramanian, M; Dhandapani, P; Sathiyanarayanan, S; Mayavan, Sundar

    2015-08-26

    We developed a single-step thermal method that enables successful inclusion of ZnO components in the porous boron-carbon-nitrogen (BCN) framework to form a new class of functional hybrid. ZnO-containing BCN hybrids were prepared by treating a mixture of B2O3, glycine, and zinc nitrate at 500 °C. Glycine-nitrate decomposition along with B2O3 acts as a source for ZnO-BCN formation. The incorporation of ZnO onto BCN has extended the photoresponse of ZnO in the visible region, which makes ZnO-BCN a preferable photocatalyst relative to ZnO upon sunlight exposure. It is interesting to note that as-prepared 2D ZnO-BCN sheets dispersed in PDMS form a stable coating over aluminum alloys. The surface exhibited a water contact angle (CA) of 157.6° with 66.6 wt % ZnO-BCN in polydimethylsiloxane (PDMS) and a water droplet (7 μL) roll-off angle of <6° and also demonstrates oil fouling resistant superhydrophobicity. In brief, the present study focuses on the gram scale synthesis of a new class of sunlight-driven photocatalyst and also its application toward the development of superhydrophobic and oleophobic coating.

  4. Changing population dynamics and uneven temperature emergence combine to exacerbate regional exposure to heat extremes under 1.5 °C and 2 °C of warming

    Science.gov (United States)

    Harrington, Luke J.; Otto, Friederike E. L.

    2018-03-01

    Understanding how continuing increases in global mean temperature will exacerbate societal exposure to extreme weather events is a question of profound importance. However, determining population exposure to the impacts of heat extremes at 1.5 °C and 2 °C of global mean warming requires not only (1) a robust understanding of the physical climate system response, but also consideration of (2) projected changes to overall population size, as well as (3) changes to where people will live in the future. This analysis introduces a new framework, adapted from studies of probabilistic event attribution, to disentangle the relative importance of regional climate emergence and changing population dynamics in the exposure to future heat extremes across multiple densely populated regions in Southern Asia and Eastern Africa (SAEA). Our results reveal that, when population is kept at 2015 levels, exposure to heat considered severe in the present decade across SAEA will increase by a factor of 4.1 (2.4-9.6) and 15.8 (5.0-135) under a 1.5°- and 2.0°-warmer world, respectively. Furthermore, projected population changes by the end of the century under an SSP1 and SSP2 scenario can further exacerbate these changes by a factor of 1.2 (1.0-1.3) and 1.5 (1.3-1.7), respectively. However, a large fraction of this additional risk increase is not related to absolute increases in population, but instead attributed to changes in which regions exhibit continued population growth into the future. Further, this added impact of population redistribution will be twice as significant after 2.0 °C of warming, relative to stabilisation at 1.5 °C, due to the non-linearity of increases in heat exposure. Irrespective of the population scenario considered, continued African population expansion will place more people in locations where emergent changes to future heat extremes are exceptionally severe.

  5. Improved Flexible Transparent Conductive Electrodes based on Silver Nanowire Networks by a Simple Sunlight Illumination Approach

    Science.gov (United States)

    Kou, Pengfei; Yang, Liu; Chang, Cheng; He, Sailing

    2017-01-01

    Silver nanowire (Ag NW) networks have attracted wide attention as transparent electrodes for emerging flexible optoelectronics. However, the sheet resistance is greatly limited by large wire-to-wire contact resistances. Here, we propose a simple sunlight illumination approach to remarkably improve their electrical conductivity without any significant degradation of the light transmittance. Because the power density is extremely low (0.1 W/cm2, 1-Sun), only slight welding between Ag NWs has been observed. Despite this, a sheet resistance of solar concentrations. Due to the reduced resistance, high-performance transparent film heaters as well as efficient defrosters have been demonstrated, which are superior to the previously-reported Ag NW based film heaters. Since the sunlight is environmentally friendly and easily available, sophisticated or expensive facilities are not necessary. Our findings are particularly meaningful and show enormous potential for outdoor applications. PMID:28169343

  6. Photodegradation of 2,4-Dichlorophenol in Aqueous Systems under Simulated and Natural Sunlight

    Directory of Open Access Journals (Sweden)

    Dorota Gryglik

    2016-01-01

    Full Text Available The work presents results of studies on 2,4-dichlorophenol (2,4-DCP degradation in aqueous solutions using photochemically initiated processes by simulated and natural sunlight. A number of possible substrate photodegradation routes were investigated, by both direct photolysis and photosensitized oxidation process. The major role of singlet oxygen in 2,4-DCP photodegradation was proved. Rose Bengal and derivatives of porphine and phthalocyanine were used as sensitizers. The influences of various process parameters on the reaction rate were investigated. On the basis of experimental data reaction rate constants of 2,4-DCP photosensitized oxidation were determined. The possibility of using natural sunlight to degrade 2,4-DCP in water in the middle latitudes was stated. The acute toxicity bioassay was conducted with the marine bacterium Vibrio fischeri as a bioluminescent indicator. The obtained results encourage further research on this process.

  7. Sunlight reflection off the spacecraft with a solar sail on the surface of mars

    Science.gov (United States)

    Starinova, O. L.; Rozhkov, M. A.; Gorbunova, I. V.

    2018-05-01

    Modern technologies make it possible to fulfill many projects in the field of space exploration. One such project is the colonization of Mars and providing favorable conditions for living on it. Authors propose principles of functioning of the spacecraft with a solar sail, intended to create a thermal and light spot in a predetermined area of the Martian surface. This additional illumination can maintain and support certain climatic conditions on a small area where a Mars base could be located. This paper investigate the possibility of the spacecraft continuously reflect the sunlight off the solar sail on the small area of the Mars surface. The mathematical motion model in such condition of the solar sail's orientation is considered and used for motion simulation session. Moreover, the analysis of this motion is performed. Thus, were obtained parameters of the synchronic non-Keplerian orbit and spacecraft construction. In addition, were given recommendations for further applying satellites to reflect the sunlight on a planet's surface.

  8. Reflected Sunlight Reduction and Characterization for a Deep-Space Optical Receiver Antenna (DSORA)

    Science.gov (United States)

    Clymer, B. D.

    1990-01-01

    A baffle system for the elimination of first-order specular and diffuse reflection of sunlight from the sunshade of a deep-space optical receiver telescope is presented. This baffle system consists of rings of 0.5cm blades spaced 2.5 cm apart on the walls of GO hexagonal sunshade tubes that combine to form the telescope sunshade. The shadow cast by the blades, walls, and rims of the tubes prevent all first-order reflections of direct sunlight from reaching the primary mirror of the telescope. A reflection model of the sunshade without baffles is also presented for comparison. Since manufacturers of absorbing surfaces do not measure data near grazing incidence, the reflection properties at anticipated angles of incidence must be characterized. A description of reflection from matte surfaces in term of bidirectional reflection distribution function (BRDF) is presented along with a discussion of measuring BRDF near grazing incidence.

  9. Photolysis of polycyclic aromatic hydrocarbons adsorbed on spruce [Picea abies (L.) Karst.] needles under sunlight irradiation

    International Nuclear Information System (INIS)

    Niu Junfeng; Chen Jingwen; Martens, D.; Quan Xie; Yang Fenglin; Kettrup, A.; Schramm, K.-W.

    2003-01-01

    Photolysis of PAHs on surfaces may determine their ultimate fate in the environment. - Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment

  10. Converting sunlight into red light in fluorosilicate glass for amorphous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Chengguo, E-mail: mingchengguo1978@163.com [Physics Department, School of Sciences, Tianjin University of Science & Technology, Tianjin 300457 (China); Song, Feng [Photonics Center, College of Physical Science, Nankai University, Tianjin 300071 (China); Ren, Xiaobin [Physics Department, School of Sciences, Tianjin University of Science & Technology, Tianjin 300457 (China); Yuan, Fengying; Qin, Yueting [Physics Department, School of Sciences, Tianjin University of Science & Technology, Tianjin 300457 (China); Photonics Center, College of Physical Science, Nankai University, Tianjin 300071 (China); An, Liqun; Cai, Yuanxue [Physics Department, School of Sciences, Tianjin University of Science & Technology, Tianjin 300457 (China)

    2017-03-15

    Fluorosilicate glass was prepared by high-temperature melting method to explore highly efficient luminescence materials for amorphous silicon solar cells. Absorption, excitation and emission spectra of the glass were measured. The optical characters of the glass were discussed in details. The glass can efficiently convert sunlight into red light. Our glass can be applied to amorphous silicon solar cells as a converter of solar spectrum.

  11. Controlling solar light and heat in a forest by managing shadow sources

    Science.gov (United States)

    Howard G. Halverson; James L. Smith

    1974-01-01

    Control of solar light and heat to develop the proper growth environment is a desirable goal in forest management. The amount of sunlight and heat reaching the surface is affected by shadows cast by nearby objects, including trees. In timbered areas, the type of forest management practiced can help develop desired microclimates. The results depend on the size and...

  12. The Photocatalytic Activity of TiO2-Zeolite Composite for Degradation of Dye Using Synthetic UV and Jeddah Sunlight

    Directory of Open Access Journals (Sweden)

    Laila M. Al-Harbi

    2015-01-01

    Full Text Available In this research different composites of impregnated TiO2 with LTA or FAU zeolites were used as different weight% ratio for photodegradation of organic dye. Normal laboratory UV-lamps were used as a source of UV irradiation. In addition a setup of system of mirrors was used to collect real Jeddah sunlight. A comparison of UV and real sunlight photodegradation activity showed that the real sunlight enhances new centers of active sites exhibiting higher catalytic activity than that of UV irradiated samples.

  13. Modified optical fiber daylighting system with sunlight transportation in free space.

    Science.gov (United States)

    Vu, Ngoc-Hai; Pham, Thanh-Tuan; Shin, Seoyong

    2016-12-26

    We present the design, optical simulation, and experiment of a modified optical fiber daylighting system (M-OFDS) for indoor lighting. The M-OFDS is comprised of three sub-systems: concentration, collimation, and distribution. The concentration part is formed by coupling a Fresnel lens with a large-core plastic optical fiber. The sunlight collected by the concentration sub-system is propagated in a plastic optical fiber and then collimated by the collimator, which is a combination of a parabolic mirror and a convex lens. The collimated beam of sunlight travels in free space and is guided to the interior by directing flat mirrors, where it is diffused uniformly by a distributor. All parameters of the system are calculated theoretically. Based on the designed system, our simulation results demonstrated a maximum optical efficiency of 71%. The simulation results also showed that sunlight could be delivered to the illumination destination at distance of 30 m. A prototype of the M-OFDS was fabricated, and preliminary experiments were performed outdoors. The simulation results and experimental results confirmed that the M-OFDS was designed effectively. A large-scale system constructed by several M-OFDSs is also proposed. The results showed that the presented optical fiber daylighting system is a strong candidate for an inexpensive and highly efficient application of solar energy in buildings.

  14. Decontamination of poultry feed from ochratoxin A by UV and sunlight radiations.

    Science.gov (United States)

    Ameer Sumbal, Gul; Hussain Shar, Zahid; Hussain Sherazi, Syed Tufail; Sirajuddin; Nizamani, Shafi Muhammad; Mahesar, Safaraz Ahmed

    2016-06-01

    Mycotoxin-contaminated feed is very dangerous for the growth and even life of poultry. The objective of the current study was to investigate the efficacy of ultra-violet irradiation for decontamination of ochratoxin A (OTA) in spiked and naturally contaminated poultry feed samples. Spiked and naturally contaminated feed samples were irradiated with ultra-violet light (UV) at distance of 25 cm over the feed samples. In vitro, the effect of UV intensity (0.1 mW cm(-2) at 254 nm UV-C) on different types of poultry feeds contaminated with OTA was evaluated. The same samples were also irradiated with sunlight and analysed for OTA by an indirect enzyme linked immunosorbent assay method. Poultry feed samples containing 500 µg kg(-1) were 100% decontaminated in 180 min with UV radiation while OTA was decreased to 70-95 µg kg(-1) using the same poultry feed samples after 8 h sunlight irradiation. Therefore, UV light was found to be more effective. Only 1 h of UV irradiation was found to be sufficient to bring the OTA level to the maximum regulatory limit suggested for poultry feeds (100 µg kg(-1) ), while 8 h were needed to obtain this level using sunlight radiations. The proposed approach is a viable option to reduce the level of OTA in contaminated poultry feeds. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  15. Interacting effects of sunlight, agriculturally derived dissolved organic matter and reactive oxygen species on fecal indicator bacteria growth dynamics

    Science.gov (United States)

    Bacterial survival in agriculturally impacted surface waters is dependent on resource availability and also on potential resource transformations, mediated by biotic and abiotic processes. In this study, we focused on the effect of sunlight irradiated cattle fecal extract (CFE) a...

  16. Comparison Study On Sunlight Or Gamma Radiation Aging Resistance Of Poly (Vinyl Pyrrolidone) Aqueous Solution With PVP Nanogel

    International Nuclear Information System (INIS)

    Doan Binh; Pham Thu Hong; Nguyen Nguyet Dieu; Nguyen Thanh Duoc

    2011-01-01

    Comparison study on sunlight or gamma-radiation aging resistance of poly (vinyl pyrrolidone) (PVP) aqueous solution with PVP nanogel at 0.5% was carried out. Sunlight or gamma- radiation aging resistance of PVP aqueous solution and nanogel was evaluated on the basis of their intrinsic viscosity, UV-VIS absorbance, weight averaged molecular weight (M w ). The PVP aqueous solution and nanogel exposed to sunlight in the storage duration of 3 months and to gamma radiation at absorbed doses of 0, 15, 30, 50 kGy were used for this study. Furthermore, the stability of PVP nanogel and of PVP aqueous solution was also studied on the change of their intrinsic viscosity, UV-VIS absorbance, weight averaged molecular weight, particle size distribution and coil size. The experimental results were shown that the aging resistance of PVP nanogel was higher than that of PVP aqueous solution when exposed to gamma radiation or sunlight. (author)

  17. Aloe sterol supplementation improves skin elasticity in Japanese men with sunlight-exposed skin: a 12-week double-blind, randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Tanaka M

    2016-11-01

    Full Text Available Miyuki Tanaka,1 Yuki Yamamoto,2 Eriko Misawa,1 Kazumi Nabeshima,1 Marie Saito,1 Koji Yamauchi,1 Fumiaki Abe,1 Fukumi Furukawa2 1Functional Food Ingredients Department, Food Ingredients & Technology Institute, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa, 2Department of Dermatology, Wakayama Medical University, Kimiidera, Wakayama, Japan Background/objective: Recently, it was confirmed that the daily oral intake of plant sterols of Aloe vera gel (Aloe sterol significantly increases the skin barrier function, moisture, and elasticity in photoprotected skin. This study aimed to investigate whether Aloe sterol intake affected skin conditions following sunlight exposure in Japanese men. Methods: We performed a 12-week, randomized, double-blind, placebo-controlled study to evaluate the effects of oral Aloe sterol supplementation on skin conditions in 48 apparently healthy men (age range: 30–59 years; average: 45 years. The subjects were instructed to expose the measurement position of the arms to the sunlight outdoors every day for 12 weeks. The skin parameters were measured at 0 (baseline, 4, 8, and 12 weeks. Results: Depending on the time for the revelation of the sunlight, the b* value and melanin index increased and the skin moisture decreased. After taking an Aloe sterol tablet daily for 12 weeks, the skin elasticity index (R2, R5, and R7 levels were significantly higher than the baseline value. There were no differences between the groups in these skin elasticity values. In the subgroup analysis of subjects aged <46 years, the change in the R5 and R7 was significantly higher in the Aloe group than in the placebo group at 8 weeks (P=0.0412 and P=0.0410, respectively. There was a difference in the quantity of sun exposure between each subject, and an additional clinical study that standardizes the amount of ultraviolet rays is warranted. No Aloe sterol intake-dependent harmful phenomenon was observed during the intake period

  18. A sunlight-induced method for rapid biosynthesis of silver nanoparticles using an Andrachnea chordifolia ethanol extract

    Energy Technology Data Exchange (ETDEWEB)

    Karimi Zarchi, A.A.; Faridi Majidi, R. [Tehran University of Medical Sciences, Department of Nanomedicine, School of Advanced Medical Technologies, Tehran (Iran, Islamic Republic of); Mokhtari, N.; Shahverdi, A.R. [Tehran University of Medical Sciences, Department of Pharmaceutical Biotechnology and Medicinal Plants Research Center, Faculty of Pharmacy, Tehran (Iran, Islamic Republic of); Arfan, M.; Rehman, T.; Ali, M. [University of Peshawar, Institute of Chemical Sciences, Peshawar, Khyber Pakhtoonkhwa (Pakistan); Amini, M. [Tehran University of Medical Sciences, Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran (Iran, Islamic Republic of)

    2011-05-15

    In this study a sunlight-induced method for rapid synthesis of silver nanoparticles using an ethanol extract of Andrachnea chordifolia is described. The silver nitrate solutions (1 mM) containing the ethanol extract of Andrachnea chordifolia were irradiated by both sunlight radiation and by sunlight radiation passed through different colored filters (red, yellow or green). The smallest size of silver nanoparticles was obtained when a silver ion solution was irradiated for 5 minutes by direct sunlight radiation. Further examination of the shape and size and of the surface chemistry of these biogenic silver nanoparticles, which were prepared under sunlight radiation, was carried out using transmission electron microscopy and infrared spectroscopy, respectively. Transmission electron microscopy images show spherical particles with an average size of 3.4 nm. Hydroxyl residues were also detected on the surface of these biogenic silver nanoparticles fabricated using plant extract of Andrachnea chordifolia under sunlight radiation. Our study on the reduction of silver ions by this plant extract in darkness shows that the synthesis process can take place under dark conditions at much longer incubations (48 hours). Larger silver polydispersed nanoparticles ranging in size from 3 to 30 nm were obtained when the silver ions were treated with the ethanol extract of Andrachnea chordifolia under dark conditions for 48 hours. (orig.)

  19. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    Science.gov (United States)

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display.

  20. One dimensional CdS nanowire@TiO2 nanoparticles core-shell as high performance photocatalyst for fast degradation of dye pollutants under visible and sunlight irradiation.

    Science.gov (United States)

    Arabzadeh, Abbas; Salimi, Abdollah

    2016-10-01

    In this study, one-dimensional CdS nanowires@TiO2 nanoparticles core-shell structures (1D CdS NWs@TiO2 NPs) were synthesized by a facile wet chemical-solvothermal method. The different aspects of the properties of CdS NWs@TiO2 NPs were surveyed by using a comprehensive range of characterization techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy, scanning electron microscopy (SEM), fluorescence spectroscopy, energy dispersive X-ray spectroscopy (EDX), Cyclic Voltammetry (CV) and amperometry. The as-prepared nanostructure was applied as an effective photocatalyst for degradation of methyl orange (MO), methylene blue (MB) and rhodamine B (Rh B) under visible and sunlight irradiation. The results indicated significantly enhanced photocatalytic activity of CdS NWs@TiO2 NPs for degradation of MO, MB and Rh B compared to CdS NWs. The enhanced photocatalytic activity could be attributed to the enhanced sunlight absorbance and the efficient charge separation of the formed heterostructure between CdS NWs and TiO2. The results showed that MO, Rh B and MB were almost completely degraded after 2, 2 and 3min of exposure to sunlight, respectively; while under visible light irradiation (3W blue LED lamp) the dyes were decomposed with less half degradation rate. The catalytic activity was retained even after three degradation cycles of organic dyes, demonstrating that the proposed nanocomposite can be effectively used as efficient photocatalyst for removal of environmental pollutions caused by organic dyes under sunlight irradiation and it could be an important addition to the field of wastewater treatment. We hope the present study may open a new window of such 1-D semiconductor nanocomposites to be used as visible light photocatalysts in the promising field of organic dyes degradation. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Roadmaps for powering the world, U.S., and individual states for all purposes with wind, water, and sunlight (Invited)

    Science.gov (United States)

    Jacobson, M. Z.

    2013-12-01

    Global warming, air pollution, and energy insecurity are three of the most significant problems facing the world today. This talk discusses these problems and technical and economic plans to solve them by powering 100% of the world, individual countries, and states for all purposes, including electricity, transportation, industry, and heating/cooling, with wind, water, and sunlight (WWS) together with efficiency measures, within 20-40 years. Specific plans for New York State and California are discussed. For California, the plan contemplates all new energy powered with WWS by 2020, 80-85% of existing energy replaced by 2030, and 100% replaced by 2050. Electrification plus modest efficiency measures would reduce California's end-use power demand ~44% and stabilize energy prices since WWS fuel costs are zero. Even without additional efficiency improvements, remaining all-purpose 2030 end-use demand could be met with 25% onshore and 10% offshore wind, 15% concentrated solar, 15% utility-scale PV, 10% residential PV, 15% commercial/government PV, 5% geothermal, 0.5% wave, 0.5% tidal, and 4% hydroelectric. These percentages will shift upon implementation. Converting would create ~137,000 net permanent jobs, decrease ~16,000 (4,800-29,600) state air pollution deaths/yr, and avoid 131 (39-296) billion/yr in health costs (6.9% of California's 2010 gross domestic product), repaying the 1 trillion capital cost for 573 GW installed power within ~7.3 yr. California's emission decreases would reduce 2050 U.S. and global climate costs by ~6 and 60 billion/yr, respectively.

  2. Formation of rutile fasciculate zone induced by sunlight irradiation at room temperature and its hemocompatibility

    International Nuclear Information System (INIS)

    Zhang, Xuan-Hui; Zheng, Xiang; Cheng, Yuan; Li, Guo-Hua; Chen, Xiao-Ping; Zheng, Jian-Hui

    2013-01-01

    The fasciculate zone of phase pure rutile was fabricated under sunlight irradiation at room temperature, using titanium tetrachloride as a sole precursor. The crystal phase, morphology and microstructure, and optical absorption behavior of the samples were characterized by X-ray Diffraction, High-Resolution Transmission Electron Microscope (HRTEM) and UV–vis Diffuse Reflectance Spectra (DRS), respectively. XRD results show that the crystal phase of the sample is composed of rutile only, and a lattice distortion displays in the crystallite of the sample. HRTEM results show that the morphology of rutile particle is fasciculate zone constituted of nanoparticles with a diameter of 4–7 nm, and these particles grow one by one and step by step. The pattern of the selected area electron diffraction of the sample is Kikuchi type, which can be attributed to the predominant orientation growth of rutile nanoparticles along [001] induced by sunlight irradiation. DRS results show that the absorption threshold of the sample is 415 nm, corresponding to the band gap energy of 2.99 eV, which is lower than the band gap energy of rutile, 3.03 eV. Blood compatibility measurement shows that the sample has no remarkable effect on hemolytic and coagulation activity. The percent hemolysis of red blood cells is less than 5% even treated with a big dosage of the fasciculate rutile and under UV irradiation, and there are no obvious changes of plasma recalcification time after the rutile treatment. Thus, the novel structure of rutile fasciculate has low potential toxicity for blood and is hemocompatibility safe. Highlights: • A novel approach to fabricate the fasciculate zone of phase pure rutile • The fasciculate grows from a particle to nanorod and to fasciculate, step by step. • A preferred orientation growth induced by sunlight irradiation in the fasciculate • The rutile fasciculate is low toxicity for blood and is hemocompatibility safe

  3. Sunlight simulators-the key to understanding the physiological effects of the sun

    CSIR Research Space (South Africa)

    Singh, A

    2006-07-01

    Full Text Available simulator Slide 4 © CSIR 2006 www.csir.co.za ۞ Benefits of natural sunlight ۞ Restrictions of lifestyles ۞ Common misconceptions ۞ Experimental setups Slide 5 © CSIR 2006 www.csir.co.za Cancer Males...,043 181,439 Lung 965,241 848,132 386,891 330,786 Melanoma of skin 79,043 21,952 81,134 18,829 Breast 1,151,298 410,712 Leukemia 171,037 125,142 129,485 97,364 All sites but skin 5,801,839 3,795,991 5,060,657 2...

  4. Bacterial growth in humic waters exposed to UV-radiation and simulated sunlight

    DEFF Research Database (Denmark)

    Corin, N.; Backlund, P.; Wiklund, T.

    1998-01-01

    Sterile filtered (0.45 mu m) humic lake water was exposed to simulated sunlight (300-800 nm) or W-radiation (254 run)for various periods of times and the dissolved organic carbon content, absorbance at 254 and 460 nm and PH were recorded. The irradiated water was inoculated with a natural bacterial...... assemblage and the number of viable bacteria war estimated 3 and 5 days after the inoculation using the plate count technique. The number of viable bacteria increased with the irradiation time indicating that the chemical changes of the humus macromolecules observed during irradiation resulted...

  5. Concentration of sunlight to solar-surface levels using non-imaging optics

    Science.gov (United States)

    Gleckman, Philip; O'Gallagher, Joseph; Winston, Roland

    1989-05-01

    An account is given of the design and operational principles of a solar concentrator that employs nonimaging optics to achieve a solar flux equal to 56,000 times that of ambient sunlight, yielding temperatures comparable to, and with further development of the device, exceeding those of the solar surface. In this scheme, a parabolic mirror primary concentrator is followed by a secondary concentrator, designed according to the edge-ray method, which is filled with a transparent oil. The device may be used in materials-processing, waste-disposal, and solar-pumped laser applications.

  6. Use of sunlight to degrade oxytetracycline in marine aquaculture's waters

    International Nuclear Information System (INIS)

    Leal, J.F.; Esteves, V.I.; Santos, E.B.H.

    2016-01-01

    Oxytracycline (OTC) is a broad spectrum antibiotic authorized for use in European aquaculture. Its photo-degradation has been widely studied in synthetic aqueous solutions, sometimes resorting to expensive methods and without proven effectiveness in natural waters. Thus, this work studied the possibility to apply the solar photo-degradation for removal of OTC from marine aquaculture's waters. For that, water samples were collected at different locals of the water treatment circuit, from two different aquaculture companies. Water samples were firstly characterized regarding to pH, salinity, total suspended solids (TSS), organic carbon and UV–Vis spectroscopic characteristics. Then, the samples were spiked with OTC and irradiated using simulated sunlight in order to evaluate the matrix effects on OTC photo-degradation. From kinetic results, the apparent quantum yields and the outdoor half-life times, at 40°N for midsummer and midwinter days were estimated by the first time for these conditions. For a midsummer day, at sea level, the outdoor half-life time predicted for OTC in these aquaculture's waters ranged between 21 and 25 min. Additionally, the pH and salinity effects on the OTC photo-degradation were evaluated and it has been shown that high pH values and the presence of sea salt increase the OTC photo-degradation rate in aquaculture's waters, compared to results in deionised water. The results are very promising to apply this low-cost methodology using the natural sunlight in aquaculture's waters to remove OTC. - Highlights: • Oxytetracycline (OTC) is one of the most used antibiotics in aquaculture. • OTC photolysis in marine aquaculture's water is faster than in deionised water. • The sunlight radiation quickly remove the OTC from aquaculture's water. • Outdoor half-life for a midsummer day is 21–25 min in aquaculture's water. • High pH's and salinities increase the OTC photo-degradation. - This work

  7. Session 6: photo-catalytic degradation of Toluene using sunlight-type excitation

    Energy Technology Data Exchange (ETDEWEB)

    Fuerte, A.; Hernandez-Alonso, M.D.; Martinez-Arias, A.; Conesa, J.C.; Soria, J.; Fernandez-Garcia, M. [Instituto de Catalisis y Petroleoquimica, CSIC, -Madrid (Spain)

    2004-07-01

    In this report we investigate the doping of anatase-TiO{sub 2} with nine different cations. It is shown that W can be one of the best options for toluene photo-degradation using sunlight-type excitation. Thermal and hydrothermal treatments were applied to amorphous Ti-W mixed oxide precursors with varying W:Ti atomic ratio for obtaining nano-structured particles having different properties. All Ti-W precursors were prepared by a microemulsion method and the mixed oxides characterized by using XRD, XPS, as well as XAFS, Raman and UV-Vis Spectroscopies. (authors)

  8. Sunlight-Induced Photochemical Degradation of Methylene Blue by Water-Soluble Carbon Nanorods

    Directory of Open Access Journals (Sweden)

    Anshu Bhati

    2016-01-01

    Full Text Available Water-soluble graphitic hollow carbon nanorods (wsCNRs are exploited for their light-driven photochemical activities under outdoor sunlight. wsCNRs were synthesized by a simple pyrolysis method from castor seed oil, without using any metal catalyst or template. wsCNRs exhibited the light-induced photochemical degradation of methylene blue used as a model pollutant by the generation of singlet oxygen species. Herein, we described a possible degradation mechanism of methylene blue under the irradiation of visible photons via the singlet oxygen-superoxide anion pathway.

  9. Persistence of marine fish environmental DNA and the influence of sunlight.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Andruszkiewicz

    Full Text Available Harnessing information encoded in environmental DNA (eDNA in marine waters has the potential to revolutionize marine biomonitoring. Whether using organism-specific quantitative PCR assays or metabarcoding in conjunction with amplicon sequencing, scientists have illustrated that realistic organism censuses can be inferred from eDNA. The next step is establishing ways to link information obtained from eDNA analyses to actual organism abundance. This is only possible by understanding the processes that control eDNA concentrations. The present study uses mesocosm experiments to study the persistence of eDNA in marine waters and explore the role of sunlight in modulating eDNA persistence. We seeded solute-permeable dialysis bags with water containing indigenous eDNA and suspended them in a large tank containing seawater. Bags were subjected to two treatments: half the bags were suspended near the water surface where they received high doses of sunlight, and half at depth where they received lower doses of sunlight. Bags were destructively sampled over the course of 87 hours. eDNA was extracted from water samples and used as template for a Scomber japonicus qPCR assay and a marine fish-specific 12S rRNA PCR assay. The latter was subsequently sequenced using a metabarcoding approach. S. japonicus eDNA, as measured by qPCR, exhibited first order decay with a rate constant ~0.01 hr -1 with no difference in decay rate constants between the two experimental treatments. eDNA metabarcoding identified 190 organizational taxonomic units (OTUs assigned to varying taxonomic ranks. There was no difference in marine fish communities as measured by eDNA metabarcoding between the two experimental treatments, but there was an effect of time. Given the differences in UVA and UVB fluence received by the two experimental treatments, we conclude that sunlight is not the main driver of fish eDNA decay in the experiments. However, there are clearly temporal effects that

  10. Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2012-09-15

    A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

  11. Heat pumps: heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pielke, R

    1976-01-01

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

  12. Increased polycyclic aromatic hydrocarbon toxicity following their photomodification in natural sunlight: impacts on the duckweed Lemna gibba L. G-3

    International Nuclear Information System (INIS)

    Huang, X.D.; Dixon, D.G.; Greenberg, B.M.

    1995-01-01

    The authors previously demonstrated that simulated solar radiation (SSR), with a fluence rate of only 40 mumol m -2 sec -1 , increased polycyclic aromatic hydrocarbon (PAH) toxicity to the duckweed Lemna gibba and that PAHs photomodified in SSR (generally oxygenation of the ring system) are more toxic than the parent compounds (Huang et al., Environ. Toxicol. Chem., 1993, 12, 1067-1077). It is not known, however, to what extent toxicity of PAHs can increase due to photomodification. Thus, natural sunlight, which has a high fluence rate (approximately 2000 mumol m -2 sec -1 ), was used to photomodify anthracene, benzo[a]pyrene, fluoranthene, phenanthrene, and pyrene. Toxicity was based on growth inhibition of L. gibba, measured as the rate of production of new leaves over an 8-day period. Initially, the toxicity of the PAHs applied in intact form was probed, with the compounds demonstrating greater toxicity in sunlight than in SSR. Next the PAHs were photomodified in sunlight prior to incubation with the plants. The half-lives of the PAHs in sunlight ranged from 12 min to 30 hr. Although most of the products of PAH photomodification are not yet identified, the degree that PAH toxicity increased following photomodification in sunlight could still be probed. The mixtures of photomodified chemicals that were derived from each PAH in sunlight were applied of L. gibba and growth inhibition under 100 mumol m -2 sec -1 of SSR was determined. The LC50s for the PAH photoproducts generated in sunlight were an order of magnitude lower than the LC50s for the PAHs applied in intact form. (author)

  13. A Novel Mechanism for the Pathogenesis of Nonmelanoma Skin Cancer Resulting from Early Exposure to Ultraviolet Light

    Science.gov (United States)

    2015-11-01

    Ultraviolet Light PRINCIPAL INVESTIGATOR: Rebecca Morris, PhD CONTRACTING ORGANIZATION: University of Minnesota, Twin Cities Minneapolis, MN 55455-2070...stem cells in response to damage, and 2) bone marrow may be a long-lived reservoir of sunlight initiated stem cells that can repopulate the skin even...proposed that sunburn following exposure to sunlight has the capacity to make skin stem cells migrate. In this Discovery award we challenged the

  14. 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.

  15. Photoelectrochemical-type sunlight photodetector based on MoS2/graphene heterostructure

    International Nuclear Information System (INIS)

    Huang, Zongyu; Han, Weijia; Chander, D Sathish; Qi, Xiang; Zhang, Han; Tang, Hongli; Ren, Long

    2015-01-01

    We have fabricated a novel sunlight photo-detector based on a MoS 2 /graphene heterostructure. The MoS 2 /graphene heterostructure was prepared by a facile hydrothermal method along with a subsequent annealing process followed by a substrate-induced high selective nucleation and growth mechanism. The microstructures and morphologies of the two-dimensional MoS 2 /graphene heterostructure can be experimentally confirmed by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a UV–vis absorption spectrometer. Photoresponse investigations performed by a photoelectrochemical (PEC) measurement system indicate that the synthesized MoS 2 /graphene heterostructure shows superior photoresponse activities under the illumination of sunlight in contrast with bare MoS 2 and graphene. The improved photoresponsivity can be attributed to the enhanced light absorption, strong light–matter interaction and the extremely efficient charge separation of the heterostructure. The structure and performances of the MoS 2 /graphene heterostructure suggest promising applications in the field of photonics and optoelectronics. (paper)

  16. A full-sunlight-driven photocatalyst with super long-persistent energy storage ability.

    Science.gov (United States)

    Li, Jie; Liu, Yuan; Zhu, Zhijian; Zhang, Guozhu; Zou, Tao; Zou, Zhijun; Zhang, Shunping; Zeng, Dawen; Xie, Changsheng

    2013-01-01

    A major drawback of traditional photocatalysts like TiO2 is that they can only work under illumination, and the light has to be UV. As a solution for this limitation, visible-light-driven energy storage photocatalysts have been developed in recent years. However, energy storage photocatalysts that are full-sunlight-driven (UV-visible-NIR) and possess long-lasting energy storage ability are lacking. Here we report, a Pt-loaded and hydrogen-treated WO3 that exhibits a strong absorption at full-sunlight spectrum (300-1,000 nm), and with a super-long energy storage time of more than 300 h to have formaldehyde degraded in dark. In this new material system, the hydrogen treated WO3 functions as the light harvesting material and energy storage material simultaneously, while Pt mainly acts as the cocatalyst to have the energy storage effect displayed. The extraordinary full-spectrum absorption effect and long persistent energy storage ability make the material a potential solar-energy storage and an effective photocatalyst in practice.

  17. A pathway for sustainable conversion of sunlight to hydrogen using proposed compact CPV system

    KAUST Repository

    Burhan, Muhammad

    2018-03-22

    Solar energy being intermittent in nature, can provide a sustainable, steady and high density energy source when converted into electrolytic hydrogen. However, in current photovoltaic market trend with 99% conventional single junction PV panels, this cannot be achieved efficiently and economically. The advent of the multi-junction solar cells (MJCs), with cell-efficiency exceeding 46%, has yet to receive wide spread acceptance in the current PV market in form of concentrated photovoltaic (CPV) system, because of its system design complexity, limiting its application scope and customers. The objective of this paper is to develop a low cost compact CPV system that will not only eliminate its application and installation related restrictions but it is also introducing a highly efficient and sustainable photovoltaic system for common consumer, to convert intermittent sunlight into green hydrogen. The developed CPV system negates the common conviction by showing two times more power output than the flat plate PV, in tropical region. In addition, sunlight to hydrogen conversion efficiency of 18% is recorded for CPV, which is two times higher than alone electricity production efficiency of flat plate PV.

  18. Roles of Saccharomyces cerevisiae DNA polymerases Poleta and Polzeta in response to irradiation by simulated sunlight.

    Science.gov (United States)

    Kozmin, Stanislav G; Pavlov, Youri I; Kunkel, Thomas A; Sage, Evelyne

    2003-08-01

    Sunlight causes lesions in DNA that if unrepaired and inaccurately replicated by DNA polymerases yield mutations that result in skin cancer in humans. Two enzymes involved in translesion synthesis (TLS) of UV-induced photolesions are DNA polymerase eta (Poleta) and polymerase zeta (Polzeta), encoded by the RAD30A and REV3 genes, respectively. Previous studies have investigated the TLS roles of these polymerases in human and yeast cells irradiated with monochromatic, short wavelength UVC radiation (254 nm). However, less is known about cellular responses to solar radiation, which is of higher and mixed wavelengths (310-1100 nm) and produces a different spectrum of DNA lesions, including Dewar photoproducts and oxidative lesions. Here we report on the comparative cytotoxic and mutagenic effects of simulated sunlight (SSL) and UVC radiation on yeast wild-type, rad30Delta, rev3Delta and rev3Delta rad30Delta strains. The results with SSL support several previous interpretations on the roles of these two polymerases in TLS of photodimers and (6-4) photoproducts derived from studies with UVC. They further suggest that Poleta participates in the non-mutagenic bypass of SSL-dependent cytosine-containing Dewar photoproducts and 8-oxoguanine, while Polzeta is mainly responsible for the mutagenic bypass of all types of Dewar photoproducts. They also suggest that in the absence of Polzeta, Poleta contributes to UVC- and SSL-induced mutagenesis, possibly by the bypass of photodimers containing deaminated cytosine.

  19. Natural organic matter and sunlight accelerate the degradation of 17ss-estradiol in water

    International Nuclear Information System (INIS)

    Leech, Dina M.; Snyder, Matthew T.; Wetzel, Robert G.

    2009-01-01

    Nanomolar concentrations of steroid hormones such as 17β-estradiol can influence the reproductive development and sex ratios of invertebrate and vertebrate populations. Thus their release into surface and ground waters from wastewater facilities and agricultural applications of animal waste is of environmental concern. Many of these compounds are chromophoric and susceptible to photolytic degradation. High intensity UV-C radiation has been demonstrated to degrade some of these compounds in engineered systems. However, the degradation efficacy of natural solar radiation in shallow fresh waters is less understood. Here photolytic experiments with 17β-estradiol demonstrated modest photodegradation (∼ 26%) when exposed to simulated sunlight between 290 and 720 nm. Photodegradation significantly increased (∼ 40-50%) in the presence of 2.0-15.0 mg/l of dissolved organic carbon (DOC) derived from humic acids of the Suwannee River, GA. However, rates of photodegradation reached a threshold at approximately 5.0 mg/l DOC. Observed suppression of photolysis in the presence of a radical inhibitor (i.e. 2-propanol) indicated that a significant proportion of the degradation was due to radicals formed from the photolysis of DOC. Although photodegradation was greatest in full sunlight containing UV-B (290-320 nm), degradation was also detected with UV-A (320-400 nm) and visible light (400-720 nm) alone

  20. A pathway for sustainable conversion of sunlight to hydrogen using proposed compact CPV system

    KAUST Repository

    Burhan, Muhammad; Shahzad, Muhammad Wakil; Oh, Seung Jin; Ng, Kim Choon

    2018-01-01

    Solar energy being intermittent in nature, can provide a sustainable, steady and high density energy source when converted into electrolytic hydrogen. However, in current photovoltaic market trend with 99% conventional single junction PV panels, this cannot be achieved efficiently and economically. The advent of the multi-junction solar cells (MJCs), with cell-efficiency exceeding 46%, has yet to receive wide spread acceptance in the current PV market in form of concentrated photovoltaic (CPV) system, because of its system design complexity, limiting its application scope and customers. The objective of this paper is to develop a low cost compact CPV system that will not only eliminate its application and installation related restrictions but it is also introducing a highly efficient and sustainable photovoltaic system for common consumer, to convert intermittent sunlight into green hydrogen. The developed CPV system negates the common conviction by showing two times more power output than the flat plate PV, in tropical region. In addition, sunlight to hydrogen conversion efficiency of 18% is recorded for CPV, which is two times higher than alone electricity production efficiency of flat plate PV.

  1. Inactivation and mutation induction in Saccharomyces cerevisiae exposed to simulated sunlight: evaluation of action spectra.

    Science.gov (United States)

    Schenk-Meuser, K; Pawlowsky, K; Kiefer, J

    1992-07-15

    The effectiveness of polychromatic light irradiation was investigated for haploid yeast cells. Inactivation and mutation induction were measured in both a RAD-wildtype strain and an excision-repair defective strain. The behaviour of vegetative "wet" cells was compared to that of dehydrated cells. The aim of the study was to assess the interaction of UVC with other wavelengths in cells of different states of humidity. The irradiation procedure was therefore carried out using a solar simulator either with full spectrum or with a UVC-blocking filter (modified sunlight) added. The results were analysed on the basis of separately determined action spectra. The summation of the efficiency of individual wavelengths was compared to the values obtained from polychromatic irradiation. It is shown that the effects caused by the whole-spectrum irradiation in wet cells can be predicted sufficiently from the calculation, while dried wildtype cells exhibit higher mutation rates. Thus it can be assumed that drying-specific damage leads to lethal and mutagenic lesions which are processed in different ways, causing a synergistic behaviour in mutation induction. Irradiation of vegetative cells with modified sunlight (UVC-) results in less inactivation and lower mutation rates than were calculated. From these results it can be concluded that this antagonistic behaviour is caused by the interaction of near-UV photoproducts.

  2. Prevalence and sunlight photolysis of controlled and chemotherapeutic drugs in aqueous environments

    International Nuclear Information System (INIS)

    Lin, Angela Yu-Chen; Lin, Yen-Ching; Lee, Wan-Ning

    2014-01-01

    This study addresses the occurrences and natural fates of chemotherapeutics and controlled drugs when found together in hospital effluents and surface waters. The results revealed the presence of 11 out of 16 drugs in hospital effluents, and the maximum detected concentrations were at the μg L −1 level in the hospital effluents and the ng L −1 level in surface waters. The highest concentrations corresponded to meperidine, morphine, 5-fluorouracil and cyclophosphamide. The sunlight photolysis of the target compounds was investigated, and the results indicated that morphine and codeine can be significantly attenuated, with half-lives of 0.27 and 2.5 h, respectively, in natural waters. Photolysis can lower the detected environmental concentrations, also lowering the estimated environmental risks of the target drugs to human health. Nevertheless, 5-fluorouracil and codeine were found to have a high risk quotient (RQ), demonstrating the high risks of directly releasing hospital wastewater into the environment. - Highlights: • High occurrence of chemotherapeutics and controlled substances in aqueous systems. • Photolysis lowers the detected concentrations of morphine and codeine. • 5-fluorouracil and codeine in hospital effluents have high risk quotients. - Chemotherapeutics and controlled drugs occur at significant levels in hospital effluents and surface waters. Natural sunlight photolysis reduces their environmental occurrence

  3. Sunlight triggers cutaneous lupus through a CSF-1-dependent mechanism in MRL-Fas(lpr) mice.

    Science.gov (United States)

    Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T; Lucas, Julie A; Rabacal, Whitney A; Croker, Byron P; Zong, Xiao-Hua; Stanley, E Richard; Kelley, Vicki R

    2008-11-15

    Sunlight (UVB) triggers cutaneous lupus erythematosus (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø)-mediated mechanism in MRL-Fas(lpr) mice. By constructing mutant MRL-Fas(lpr) strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex vivo gene transfer to deliver CSF-1 intradermally, we determined that CSF-1 induces CLE in lupus-susceptible MRL-Fas(lpr) mice, but not in lupus-resistant BALB/c mice. UVB incites an increase in Møs, apoptosis in the skin, and CLE in MRL-Fas(lpr), but not in CSF-1-deficient MRL-Fas(lpr) mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Møs that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Fas(lpr) but not lupus-resistant BALB/c mice. Taken together, CSF-1 is envisioned as the match and lupus susceptibility as the tinder leading to CLE.

  4. Natural organic matter and sunlight accelerate the degradation of 17ss-estradiol in water

    Energy Technology Data Exchange (ETDEWEB)

    Leech, Dina M. [Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557 (United States)], E-mail: dmleech@email.unc.edu; Snyder, Matthew T.; Wetzel, Robert G. [Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2009-03-01

    Nanomolar concentrations of steroid hormones such as 17{beta}-estradiol can influence the reproductive development and sex ratios of invertebrate and vertebrate populations. Thus their release into surface and ground waters from wastewater facilities and agricultural applications of animal waste is of environmental concern. Many of these compounds are chromophoric and susceptible to photolytic degradation. High intensity UV-C radiation has been demonstrated to degrade some of these compounds in engineered systems. However, the degradation efficacy of natural solar radiation in shallow fresh waters is less understood. Here photolytic experiments with 17{beta}-estradiol demonstrated modest photodegradation ({approx} 26%) when exposed to simulated sunlight between 290 and 720 nm. Photodegradation significantly increased ({approx} 40-50%) in the presence of 2.0-15.0 mg/l of dissolved organic carbon (DOC) derived from humic acids of the Suwannee River, GA. However, rates of photodegradation reached a threshold at approximately 5.0 mg/l DOC. Observed suppression of photolysis in the presence of a radical inhibitor (i.e. 2-propanol) indicated that a significant proportion of the degradation was due to radicals formed from the photolysis of DOC. Although photodegradation was greatest in full sunlight containing UV-B (290-320 nm), degradation was also detected with UV-A (320-400 nm) and visible light (400-720 nm) alone.

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

    Science.gov (United States)

    Vanselow, Jens; Vernunft, Andreas; Koczan, Dirk; Spitschak, Marion; Kuhla, Björn

    2016-01-01

    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. PMID:27532452

  6. 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

  7. 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

    International Nuclear Information System (INIS)

    Laclau, M.; Billaudel, B.; Taxil, M.; Haro, E.; Ruffie, G.; Sanchez, S.; Poulletier De Gannes, F.; Lagroye, I.; Veyret, B.

    2006-01-01

    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

  8. Effect of sunlight irradiation on photocatalytic pyrene degradation in contaminated soils by micro-nano size TiO2

    International Nuclear Information System (INIS)

    Chang Chien, S.W.; Chang, C.H.; Chen, S.H.; Wang, M.C.; Madhava Rao, M.; Satya Veni, S.

    2011-01-01

    The enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils by micro-nano size TiO 2 in the presence and absence of sunlight was investigated. The results showed that the synergistic effect of sunlight irradiation and TiO 2 was more efficient on pyrene degradation in quartz sand and red and alluvial soils than the corresponding reaction system without sunlight irradiation. In the presence of sunlight irradiation, the photooxidation (without TiO 2 ) of pyrene was very pronounced in alluvial and red soils and especially in quartz sand. However, in the absence of sunlight irradiation, the catalytic pyrene degradation by TiO 2 and the photooxidation (without TiO 2 ) of pyrene were almost nil. This implicates that ultra-violet (UV) wavelength range of sunlight plays an important role in TiO 2 -enhanced photocatalytic pyrene degradation and in photooxidation (without TiO 2 ) of pyrene. The percentages of photocatalytic pyrene degradation by TiO 2 in quartz sand, alluvial and red soils under sunlight irradiation were 78.3, 23.4, and 31.8%, respectively, at 5 h reaction period with a 5% (w/w) dose of the amended catalyst. The sequence of TiO 2 -enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils was quartz sand > red soil > alluvial soil, due to different texture and total organic carbon (TOC) contents of the quartz sand and other two soils. The differential Fourier transform infrared (FT-IR) spectra of degraded pyrene in alluvial soil corroborate that TiO 2 -enhanced photocatalytic degradation rate of degraded pyrene was much greater than photooxidation (without TiO 2 ) rate of degraded pyrene. Based on the data obtained, the importance for the application of TiO 2 -enhanced photocatalytic pyrene degradation and associated organic contaminants in contaminated soils was elucidated. - Highlights: → Synergistic effect of sunlight irradiation and TiO 2 promoted degradation of pyrene. → Micro-nano size TiO 2 enhanced

  9. 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

  10. Heat pipe heat storage performance

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-01-01

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

  11. Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

    Science.gov (United States)

    Ferro, Giovanna; Polo-López, María I; Martínez-Piernas, Ana B; Fernández-Ibáñez, Pilar; Agüera, Ana; Rizzo, Luigi

    2015-09-15

    The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.

  12. 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.

  13. Heat transfer

    Indian Academy of Sciences (India)

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

  14. Heat Waves

    Science.gov (United States)

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

  15. 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.

  16. Production of diketopiperazine derivative cyclo (l-leu-l-arg) by streptomyces sp. tn262 after exposure to heat-killed fungus fusarium sp

    International Nuclear Information System (INIS)

    Elleuch, L.; Smaoui, S.; Najah, S.; Sellem, I

    2013-01-01

    In a screening program for new active secondary metabolites producers, a strain of Streptomyces called TN262 was isolated from Tunisian soil and selected for its ability to produce eleven active compounds in pure culture conditions. In this work, the effect of different concentrations of heat-killed fungus Fusarium sp. on the production of active compounds by TN262 strain was studied. The ethyl acetate extract from the culture of Streptomyces sp. TN262 combined with heat-killed Fusarium sp. at 50 micro g/ml inhibited the growth of the three used indicator microorganisms. In fact, an increase of 36%, 21% and 20% in inhibitory activity was obtained against Micrococcus luteus LB 14110, Escherichia coli ATCC 8739 and Fusarium sp. respectively. The HPLC chromatographic profiles of the ethyl acetate extracts from both culture conditions were different and an additional active compound was produced only under induced conditions. This active component was isolated and identified as Cyclo (L-Leu-L-Arg) (1), a diketopiperazine derivative, possessing antibacterial and antifungal activity. Consequently, this study showed that the addition of heat-killed fungus is a useful method for inducing the production of bioactive compounds. (author)

  17. Effects of smartphone diaries and personal dosimeters on behavior in a randomized study of methods to document sunlight exposure

    DEFF Research Database (Denmark)

    Køster, Brian; Søndergaard, Jens; Nielsen, Jesper Bo

    2016-01-01

    study. We examined the effects of wearing dosimeters and filling out diaries, measurement period and recall effect on the sun-related behavior in Denmark in 2012.Our sample included 240 participants eligible by smartphone status and who took a vacation during weeks 26-32 in 2012, randomized by gender...

  18. Features of heat stress control

    International Nuclear Information System (INIS)

    Bernard, T.E.

    1989-01-01

    Heat stress is caused by hot environments and physical demands of work. It is further complicated by protective clothing requirements commonly found in the nuclear power industry. The resulting physiological strain is reflected in increased sweating, heart rate and body temperature. Uncontrolled exposures to heat stress will lead to decreased personnel performance and increased risk of accidents and heat disorders. The article describes major heat disorders, a method of heat stress evaluation, and some basic interventions to reduce the stress and strain of working in the heat

  19. Graphene-SnO2 composites for highly efficient photocatalytic degradation of methylene blue under sunlight.

    Science.gov (United States)

    Seema, Humaira; Christian Kemp, K; Chandra, Vimlesh; Kim, Kwang S

    2012-09-07

    Graphene sheets decorated with SnO(2) nanoparticles (RGO-SnO(2)) were prepared via a redox reaction between graphene oxide (GO) and SnCl(2). Graphene oxide (GO) was reduced to graphene (RGO) and Sn(2+) was oxidized to SnO(2) during the redox reaction, leading to a homogeneous distribution of SnO(2) nanoparticles on RGO sheets. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show uniform distribution of the nanoparticles on the RGO surface and high-resolution transmission electron microscopy (HRTEM) shows an average particle size of 3-5 nm. The RGO-SnO(2) composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO(2) nanoparticles. This result leads us to believe that the RGO-SnO(2) composite could be used in catalytic photodegradation of other organic dyes.

  20. Sunlight effects on the 3D polar current system determined from low Earth orbit measurements

    DEFF Research Database (Denmark)

    Laundal, Karl M.; Finlay, Chris; Olsen, Nils

    2016-01-01

    Interaction between the solar wind and the Earth’s magnetosphere is associated with large-scale currents in the ionosphere at polar latitudes that flow along magnetic field lines (Birkeland currents) and horizontally. These current systems are tightly linked, but their global behaviors are rarely...... analyzed together. In this paper, we present estimates of the average global Birkeland currents and horizontal ionospheric currents from the same set of magnetic field measurements. The magnetic field measurements, from the low Earth orbiting Swarm and CHAMP satellites, are used to co-estimate poloidal...... and toroidal parts of the magnetic disturbance field, represented in magnetic apex coordinates. The use of apex coordinates reduces effects of longitudinal and hemispheric variations in the Earth’s main field. We present global currents from both hemispheres during different sunlight conditions. The results...

  1. On the apparent velocity of integrated sunlight. I - 1983-1985

    Science.gov (United States)

    Deming, Drake; Espenak, Fred; Jennings, Donald E.; Brault, James W.; Wagner, Jeremy

    1987-01-01

    Frequency measurements for the Delta V = 2 transitions of CO in the integrated light spectrum of the sun are presented. The nature and magnitude of systematic errors which typically arise in absolute velocity measurements of integrated sunlight are explored in some detail, and measurements believed accurate at the level of about 5 m/s or less are presented. It is found that the integrated light velocity varies by about 3 m/s or less over a one-day period. Over the long term, the data indicate an increasing blue-shift in these weak infrared lines amounting to 30 m/s from 1983 to 1985. The sense of the drift is consistent with a lessening in the magnetic inhibition of granular convection at solar minimum. Such an effect has implications for the spectroscopic detectability of planetary-mass companions to solar-type stars.

  2. Type II GaSb quantum ring solar cells under concentrated sunlight.

    Science.gov (United States)

    Tsai, Che-Pin; Hsu, Shun-Chieh; Lin, Shih-Yen; Chang, Ching-Wen; Tu, Li-Wei; Chen, Kun-Cheng; Lay, Tsong-Sheng; Lin, Chien-Chung

    2014-03-10

    A type II GaSb quantum ring solar cell is fabricated and measured under the concentrated sunlight. The external quantum efficiency confirms the extended absorption from the quantum rings at long wavelength coinciding with the photoluminescence results. The short-circuit current of the quantum ring devices is 5.1% to 9.9% more than the GaAs reference's under various concentrations. While the quantum ring solar cell does not exceed its GaAs counterpart in efficiency under one-sun, the recovery of the open-circuit voltages at higher concentration helps to reverse the situation. A slightly higher efficiency (10.31% vs. 10.29%) is reported for the quantum ring device against the GaAs one.

  3. Degradation of 4-Chlorophenol Under Sunlight Using ZnO Nanoparticles as Catalysts

    Science.gov (United States)

    Rajar, Kausar; Sirajuddin; Balouch, Aamna; Bhanger, M. I.; Sherazi, Tufail H.; Kumar, Raj

    2018-03-01

    Herein we demonstrate a simplistic microwave assisted chemical precipitation approach regarding the synthesis of zinc oxide nanoparticles. As-prepared ZnO nanoparticles (NPs) were characterized by UV-visible spectroscopy, Fourier transform infra-red spectroscopy, atomic force microscopy and x-ray diffractometry and scrutinized as photo-catalysts for degradation of 4-chlorophenol (4-CP) under sunlight. The study substantiated that 98.5% of 4-CP was degraded within 20 min in the absence of initiator like H2O2 which reflects an outstanding prospective use for ZnO NPs as photo-catalysts. The nanocatalysts were recycled four times and still showed catalytic efficiency up to 95.5% for degradation of 4-CP in the specified 20 min.

  4. Sunlight-assisted synthesis of colloidal silver nanoparticles using chitosan as reducing agent

    Science.gov (United States)

    Susilowati, E.; Maryani; Ashadi

    2018-04-01

    The present study we explore an environmentally friendly colloidal silver nanoparticles preparation using chitosan as reducing agent and stabilizer. It develops a new strategy on preparation of silver nanoparticles through the gel phase using sodium hydroxide (NaOH) as accelerator reagent. Sunlight irradiation was employed to assisted reducing process of silver ions to silver nanoparticles. Localized surface plasmon resonance (LSPR) phenomenon of silver nanoparticles was investigated using UV-Vis spectrophotometer. The shape and size of silver particles were analyzed using TEM. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 396.0–412.0 nm. The absorption peak of LSPR were affected by NaOH amount, time of sulight irradiation and concentration of AgNO3. The produced silver nanoparticles were spherical with dominant size range of 5 to 8 nm as shown by TEM images. All colloidals were stable without any aggregation for 30 days after preparation.

  5. Recovery of hexavalent chromium from water using photoactive TiO2-montmorillonite under sunlight

    Directory of Open Access Journals (Sweden)

    Ridha Djellabi

    2016-04-01

    Full Text Available Hexavalent chromium was removed from water under sunlight using a synthesized TiO2-montmorillonite (TiO2-M employing tartaric acid as a hole scavenger. Cr(VI species was then reduced to Cr(III species by electrons arising from TiO2 particles. After that, the produced Cr(III species  was transferred to montmorillonite  due to electrostatic attractions leading to  set free TiO2 particles for a further Cr(VI species reduction. Furthermore, produced Cr(III, after Cr(VI reduction, does not  penetrate into the solution. The results indicate that no dark adsorption of Cr(VI species on TiO2-M is present, however, the reduction of Cr(VI species under sunlight increased strongly as a function of tartaric acid concentration up to 60 ppm, for which the extent of reduction is maximum within 3 h. On the other hand, the reduction extent of Cr(VI species is maximum with an initial concentration of Cr(VI species lower than 30 ppm by the use of 0.2 g/L of TiO2-M. Nevertheless, the increase of the Cr(VI initial concentration led to increase the amount of Cr(VI species reduced (capacity of reduction until a Cr(VI concentration of 75 and 100 ppm, for which  it remained constant at around 221 mg/g. For comparison, the increase of Cr(VI species concentration in the case of the commercial TiO2 P25 under the same conditions exhibited its deactivation when the reduced amount decreased from 198.1 to 157.6 mg/g as the concentration increased from 75 to 100 ppm.

  6. On the apparent velocity of integrated sunlight. 2: 1983-1992 and comparisons with magnetograms

    Science.gov (United States)

    Deming, Drake; Plymate, Claude

    1994-01-01

    We report additional results in our program to monitor the wavelength stability of lines in the 2.3 micrometer spectrum of integrated sunlight. We use the McMath Fourier transform spectrometer (FTS) of the National Solar Observatory to monitor 16 delta V = 2 lines of (12)C(16)O, as well as five atomic lines. Wavenumber calibration is achieved using a low-pressure N2O absorption cell and checked against terrestrial atmospheric lines. Imperfect optical integration of the solar disk remains the principal source of error, but this error has been reduced by improved FTS/telescope collimation and observing procedures. The present results include data from an additional 13 quarterly observing runs since 1985. We continue to find that the apparent velocity of integrated sunlight is variable, in the sense of having a greater reshift at solar maximum. This is supported by the temporal dependence of the integrated light velocity, and by the presence of a correlation between velocity and the disk-averaged magnetic flux derived from Kitt Peak magnetograms. The indicated peak-to-peak apparent velocity amplitude over a solar cycle is approximately the same as the velocity amplitude of the Sun's motion about the solar system barycenter. This represents about half the amplitude which we inferred in Paper I (Deming et al. 1987), but the present result has a much greater statistical significance. Our results have implications for those investigations which search for the Doppler signatures of planetary-mass companions to solar-type stars. We contrast our results to the recent finding by McMillan et al. 1993 that solar absorption lines in the violet spectral region are wavelength-stable over the solar cycle.

  7. Molecular and sensory mechanisms to mitigate sunlight-induced DNA damage in treefrog tadpoles.

    Science.gov (United States)

    Schuch, André P; Lipinski, Victor M; Santos, Mauricio B; Santos, Caroline P; Jardim, Sinara S; Cechin, Sonia Z; Loreto, Elgion L S

    2015-10-01

    The increased incidence of solar ultraviolet B (UVB) radiation has been proposed as an environmental stressor, which may help to explain the enigmatic decline of amphibian populations worldwide. Despite growing knowledge regarding the UV-induced biological effects in several amphibian models, little is known about the efficacy of DNA repair pathways. In addition, little attention has been given to the interplay between these molecular mechanisms with other physiological strategies that avoid the damage induced by sunlight. Here, DNA lesions induced by environmental doses of solar UVB and UVA radiation were detected in genomic DNA samples of treefrog tadpoles (Hypsiboas pulchellus) and their DNA repair activity was evaluated. These data were complemented by monitoring the induction of apoptosis in blood cells and tadpole survival. Furthermore, the tadpoles' ability to perceive and escape from UV wavelengths was evaluated as an additional strategy of photoprotection. The results show that tadpoles are very sensitive to UVB light, which could be explained by the slow DNA repair rates for both cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6,4) pyrimidone photoproducts (6,4PPs). However, they were resistant to UVA, probably as a result of the activation of photolyases during UVA irradiation. Surprisingly, a sensory mechanism that triggers their escape from UVB and UVA light avoids the generation of DNA damage and helps to maintain the genomic integrity. This work demonstrates the genotoxic impact of both UVB and UVA radiation on tadpoles and emphasizes the importance of the interplay between molecular and sensory mechanisms to minimize the damage caused by sunlight. © 2015. Published by The Company of Biologists Ltd.

  8. Analyses of Hubble Space Telescope Aluminized-Teflon Multilayer Insulation Blankets Retrieved After 19 Years of Space Exposure

    Science.gov (United States)

    de Groh, Kim K.; Perry, Bruce A.; Mohammed, Jelila S.; Banks, Bruce

    2015-01-01

    Since its launch in April 1990, the Hubble Space Telescope (HST) has made many important observations from its vantage point in low Earth orbit (LEO). However, as seen during five servicing missions, the outer layer of multilayer insulation (MLI) has become increasingly embrittled and has cracked in many areas. In May 2009, during the 5th servicing mission (called SM4), two MLI blankets were replaced with new insulation and the space-exposed MLI blankets were retrieved for degradation analyses by teams at NASA Glenn Research Center (GRC) and NASA Goddard Space Flight Center (GSFC). The retrieved MLI blankets were from Equipment Bay 8, which received direct sunlight, and Equipment Bay 5, which received grazing sunlight. Each blanket was divided into several regions based on environmental exposure and/or physical appearance. The aluminized-Teflon (DuPont, Wilmington, DE) fluorinated ethylene propylene (Al-FEP) outer layers of the retrieved MLI blankets have been analyzed for changes in optical, physical, and mechanical properties, along with chemical and morphological changes. Pristine and as-retrieved samples (materials) were heat treated to help understand degradation mechanisms. When compared to pristine material, the analyses have shown how the Al-FEP was severely affected by the space environment. Most notably, the Al-FEP was highly embrittled, fracturing like glass at strains of 1 to 8 percent. Across all measured properties, more significant degradation was observed for Bay 8 material as compared to Bay 5 material. This paper reviews the tensile and bend-test properties, density, thickness, solar absorptance, thermal emittance, x-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) elemental composition measurements, surface and crack morphologies, and atomic oxygen erosion yields of the Al-FEP outer layer of the retrieved HST blankets after 19 years of space exposure.

  9. Heat stress disorders and headache: a case of new daily persistent headache secondary to heat stroke

    OpenAIRE

    Di Lorenzo, C; Ambrosini, A; Coppola, G; Pierelli, F

    2009-01-01

    Headache is considered as a common symptom of heat stress disorders (HSD), but no forms of secondary headache from heat exposure are reported in the International Classification of Headache Disorders-2 Edition (ICHD-II). Heat-stroke (HS) is the HSD most severe condition, it may be divided into two forms: classic (due to a long period environmental heat exposure) and exertional (a severe condition caused by strenuous physical exercises in heat environmental conditions). Here we report the case...

  10. Micro- and nano-scale damage on the surface of W divertor component during exposure to high heat flux loads with He

    International Nuclear Information System (INIS)

    Li, C.; Greuner, H.; Zhao, S.X.; Böswirth, B.; Luo, G.N.; Zhou, X.; Jia, Y.Z.; Liu, X.; Liu, W.

    2015-01-01

    Micro- and nano-scale surface damage on a W divertor component sample exposed to high heat flux loads generated with He atoms has been investigated through SEM, EBSD, AFM and FIB-SEM. The component sample was supplied by the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) and AT&M company, China, and the loading experiment was performed in the GLADIS facility at IPP Garching, Germany. Two typical damage structures were observed on the surface: the first one is characterized by obvious blisters and some grooves formed from ruptured blisters, and the other one is a kind of porous structure accompanying with at least ∼25 nm surface material loss. As the grain orientation is further away from , the damage morphology gradually changes from the former structure to the latter. The possible damage mechanism is discussed. - Highlights: • Two damage structures were observed on W component surface under He beam heating. • Blistering was more obvious in near grains. • Porous structure appeared in the grains away from . • A loose layer caused by He aggregation was formed in near-surface region.

  11. Heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-04-01

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

  12. 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

    .6% of the variance in WTL (p manager's WTL estimate was too optimistic (p Time-motion analysis accurately assesses WTL, evaluating every second spent by each worker during every work shift......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...

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

    International Nuclear Information System (INIS)

    Wilkes, Bernd; Bienentreu, Robert

    2008-01-01

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

  14. Solar-heating and hot water system--St. Louis, Missouri

    Science.gov (United States)

    1981-01-01

    Sunlight supplies about half heat energy needs of small office. System includes six tilt-adjustable commercial collectors and 1,000 gallon energy storage tank. Report contains description of system and components, drawings and photographs, manufacturer's data, and related material.

  15. 76 FR 62052 - Issuance of a Loan Guarantee to First Solar, Inc., for the Desert Sunlight Solar Farm Project

    Science.gov (United States)

    2011-10-06

    ... DEPARTMENT OF ENERGY Issuance of a Loan Guarantee to First Solar, Inc., for the Desert Sunlight Solar Farm Project AGENCY: U.S. Department of Energy. ACTION: Record of decision. SUMMARY: The U.S... The proposed DSSFP is a photovoltaic solar electrical generating facility using commercial, thin-film...

  16. Use of sunlight to partially detoxify groundnut (peanut) cake flour and casein contaminated with aflatoxin B1.

    Science.gov (United States)

    Shantha, T; Murthy, V S

    1981-03-01

    Sunlight destroyed 83 and 50% of the toxin added to casein and groundnut cake flour, respectively. Equilibrium dialysis revealed that both casein and groundnut protein bind aflatoxin but the toxin bound to casein appeared more photo-labile than that bound to groundnut protein.

  17. 76 FR 50493 - Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert...

    Science.gov (United States)

    2011-08-15

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [CACA-48649, LLCAD06000 L51010000 ER0000... right-of-way (ROW) application CACA-48649 for the Desert Sunlight Solar Farm Project (DSSF). The DSSF is... (CACA-052682) where the project would interconnect with the SCE regional transmission system. The DSSF...

  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

    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

  19. Diffused sunlight driven highly synergistic pathway for complete mineralization of organic contaminants using reduced graphene oxide supported photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Babu, Sundaram Ganesh; Ramalingam Vinoth [SRM Research Institute, SRM University, Kattankulathur 603203, Chennai, Tamilnadu (India); Neppolian, Bernaurdshaw, E-mail: neppolian.b@res.srmuniv.ac.in [SRM Research Institute, SRM University, Kattankulathur 603203, Chennai, Tamilnadu (India); Dionysiou, Dionysios D. [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Ashokkumar, Muthupandian [The School of Chemistry, University of Melbourne, Parkville, Melbourne, Victoria 3010 (Australia)

    2015-06-30

    Highlights: • Diffused sunlight is firstly used as an effective source for the degradation of organics. • More than 10 fold synergistic effect is achieved by sono-photocatalysis. • rGO enhances the degradation efficiency up to 54% as compared with CuO–TiO{sub 2} alone. • Plausible mechanism and intermediates formed are supported with experimental studies. - Abstract: Diffused sunlight is found to be an effective light source for the efficient degradation and mineralization of organic pollutant (methyl orange as a probe) by sono-photocatalytic degradation using reduced graphene oxide (rGO) supported CuO–TiO{sub 2} photocatalyst. The prepared catalysts are characterized by XRD, XPS, UV–vis DRS, PL, photoelectrochemical, SEM-EDS and TEM. A 10 fold synergy is achieved for the first time by combining sonochemical and photocatalytic degradation under diffused sunlight. rGO loading augments the activity of bare CuO–TiO{sub 2} more than two fold. The ability of rGO in storing, transferring, and shuttling electrons at the heterojunction between TiO{sub 2} and CuO facilitates the separation of photogenerated electron–hole pairs, as evidenced by the photoluminescence results. The complete mineralization of MO and the by-products within a short span of time is confirmed by TOC analysis. Further, hydroxyl radical mediated degradation under diffused sunlight is confirmed by LC–MS. This system shows similar activity for the degradation of methylene blue and 4-chlorophenol indicating the versatility of the catalyst for the degradation of various pollutants. This investigation is likely to open new possibilities for the development of highly efficient diffused sunlight driven TiO{sub 2} based photocatalysts for the complete mineralization of organic contaminants.

  20. Modification of Sunlight Radiation through Colored Photo-Selective Nets Affects Anthocyanin Profile in Vaccinium spp. Berries.

    Directory of Open Access Journals (Sweden)

    Laura Zoratti

    Full Text Available In recent years, the interest on the effects of the specific wavelengths of the light spectrum on growth and metabolism of plants has been increasing markedly. The present study covers the effect of modified sunlight conditions on the accumulation of anthocyanin pigments in two Vaccinium species: the European wild bilberry (V. myrtillus L. and the cultivated highbush blueberry (V. corymbosum L..The two Vaccinium species were grown in the same test field in the Alps of Trentino (Northern Italy under modified light environment. The modification of sunlight radiation was carried out in field, through the use of colored photo-selective nets throughout the berry ripening during two consecutive growing seasons. The anthocyanin profile was then assessed in berries at ripeness.The results indicated that the light responses of the two Vaccinium species studied were different. Although both studied species are shade-adapted plants, 90% shading of sunlight radiation was beneficial only for bilberry plants, which accumulated the highest content of anthocyanins in both seasons. The same condition, instead, was not favorable for blueberries, whose maturation was delayed for at least two weeks, and anthocyanin accumulation was significantly decreased compared to berries grown under sunlight conditions. Moreover, the growing season had strong influence on the anthocyanin accumulation in both species, in relation to temperature flow and sunlight spectra composition during the berry ripening period.Our results suggest that the use of colored photo-selective nets may be a complementary agricultural practice for cultivation of Vaccinium species. However, further studies are needed to analyze the effect of the light spectra modifications to other nutritional properties, and to elucidate the molecular mechanisms behind the detected differences between the two relative Vaccinium species.

  1. Modification of Sunlight Radiation through Colored Photo-Selective Nets Affects Anthocyanin Profile in Vaccinium spp. Berries.

    Science.gov (United States)

    Zoratti, Laura; Jaakola, Laura; Häggman, Hely; Giongo, Lara

    2015-01-01

    In recent years, the interest on the effects of the specific wavelengths of the light spectrum on growth and metabolism of plants has been increasing markedly. The present study covers the effect of modified sunlight conditions on the accumulation of anthocyanin pigments in two Vaccinium species: the European wild bilberry (V. myrtillus L.) and the cultivated highbush blueberry (V. corymbosum L.). The two Vaccinium species were grown in the same test field in the Alps of Trentino (Northern Italy) under modified light environment. The modification of sunlight radiation was carried out in field, through the use of colored photo-selective nets throughout the berry ripening during two consecutive growing seasons. The anthocyanin profile was then assessed in berries at ripeness. The results indicated that the light responses of the two Vaccinium species studied were different. Although both studied species are shade-adapted plants, 90% shading of sunlight radiation was beneficial only for bilberry plants, which accumulated the highest content of anthocyanins in both seasons. The same condition, instead, was not favorable for blueberries, whose maturation was delayed for at least two weeks, and anthocyanin accumulation was significantly decreased compared to berries grown under sunlight conditions. Moreover, the growing season had strong influence on the anthocyanin accumulation in both species, in relation to temperature flow and sunlight spectra composition during the berry ripening period. Our results suggest that the use of colored photo-selective nets may be a complementary agricultural practice for cultivation of Vaccinium species. However, further studies are needed to analyze the effect of the light spectra modifications to other nutritional properties, and to elucidate the molecular mechanisms behind the detected differences between the two relative Vaccinium species.

  2. The recommended Threshold Limit Values for heat exposure fail to maintain body core temperature within safe limits in older working adults.

    Science.gov (United States)

    Lamarche, Dallon T; Meade, Robert D; D'Souza, Andrew W; Flouris, Andreas D; Hardcastle, Stephen G; Sigal, Ronald J; Boulay, Pierre; Kenny, Glen P

    2017-09-01

    The American Conference of Governmental and Industrial Hygienists (ACGIH®) Threshold Limit Values (TLV® guidelines) for work in the heat consist of work-rest (WR) allocations designed to ensure a stable core temperature that does not exceed 38°C. However, the TLV® guidelines have not been validated in older workers. This is an important shortcoming given that adults as young as 40 years demonstrate impairments in their ability to dissipate heat. We therefore evaluated body temperature responses in older adults during work performed in accordance to the TLV® recommended guidelines. On three occasions, 9 healthy older (58 ± 5 years) males performed a 120-min work-simulated protocol in accordance with the TLV® guidelines for moderate-to-heavy intensity work (360 W fixed rate of heat production) in different wet-bulb globe temperatures (WBGT). The first was 120 min of continuous (CON) cycling at 28.0°C WBGT (CON[28°C]). The other two protocols were 15-min intermittent work bouts performed with different WR cycles and WBGT: (i) WR of 3:1 at 29.0°C (WR3:1[29°C]) and (ii) WR of 1:1 at 30.0°C (WR1:1[30°C]). Rectal temperature was measured continuously. The rate of change in mean body temperature was determined via thermometry (weighting coefficients: rectal, 0.9; mean skin temperature, 0.1) and direct calorimetry. Rectal temperature exceeded 38°C in all participants in CON[28°C] and WR3:1[29°C] whereas a statistically similar proportion of workers exceeded 38°C in WR1:1[30°C] (χ 2 ; P = 0.32). The average time for rectal temperature to reach 38°C was: CON[28°C], 53 ± 7; WR3:1[29°C], 79 ± 11; and WR1:1[30°C], 100 ± 29 min. Finally, while a stable mean body temperature was not achieved in any work condition as measured by thermometry (i.e., >0°C·min -1 ; all Pheat balance as determined by direct calorimetry was achieved in WR3:1[29°C] and WR1:1[30°C] (both P ≥ 0.08). Our findings indicate that the TLV® guidelines do not prevent body core

  3. Paving materials for heat island mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Pomerantz, M.; Akbari, H.; Chen, A.; Taha, H. [Lawrence Berkeley National Lab., CA (United States); Rosenfeld, A.H. [Dept. of Energy, Washington, DC (United States)

    1997-11-01

    This report summarizes paving materials suitable for urban streets, driveways, parking lots and walkways. The authors evaluate materials for their abilities to reflect sunlight, which will reduce their temperatures. This in turn reduces the excess air temperature of cities (the heat island effect). The report presents the compositions of the materials, their suitability for particular applications, and their approximate costs (in 1996). Both new and resurfacing are described. They conclude that, although light-colored materials may be more expensive than conventional black materials, a thin layer of light-colored pavement may produce energy savings and smog reductions whose long-term worth is greater than the extra cost.

  4. Method and equipment to utilize solar heat. [paraffin used as heat storage material

    Energy Technology Data Exchange (ETDEWEB)

    Poellein, H

    1976-09-16

    In this process, solar radiation is converted into heat by means of absorbers. The heat transferred to a liquid is led in forced circulation, first into a heat storage device and then into a water heater. The cooled-down liquid is rercirculated. The storage material used here is paraffin. A measuring and control device is provided to switch from periods with solar radiation to periods where only stored energy is consumed. This device consists of a photocell measuring the incoming sunlight and a temperarure sensor. The control system is put into operation by a combination of the two measured values. The heat accumulator consists of several elements connected in parallel. A control device makes sure that only one accumulator element at a time is part of the circuit. The absorbers, as usual, consists of the absorber plate proper and a cover plate.

  5. 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.

  6. Placebo Responses to Original vs. Generic ASA Brands During Exposure to Noxious Heat: A Pilot fMRI Study of Neurofunctional Correlates.

    Science.gov (United States)

    Fehse, Kai; Maikowski, Lea; Simmank, Fabian; Gutyrchik, Evgeny; Meissner, Karin

    2015-10-01

    We studied the expectation effects associated with brands by labeling placebo interventions (original and generic analgesic) and investigating the potential differences in efficacy between the two placebos in dealing with noxious heat pain, as well as exploring the neurometabolic correlates of the placebo response. We applied a two by two design with two identical placebo interventions that differed only in their labeling. One group was told that they received 500 mg of "Aspirin" (original brand) while the other group was told that they received a popular ASA generic (1A Pharma). After establishing the individual pain level of each subject, we measured pain intensities behaviorally before and after the intervention and looked for corresponding brain areas with increased hemodynamic response using functional magnetic resonance imaging. At the behavioral level, we found decreases in pain intensity from baseline to the intervention condition with the original brand only. At the neuronal level, we specifically observed activations of the anterior insulae under the baseline conditions, complemented by activations of the dorsomedial prefrontal cortex after the interventions. A direct comparison of the two placebo conditions revealed higher values of activation for the bilateral dorsolateral (as well as dorsomedial) prefrontal cortex for the original brand. Our data indicate a behavioral placebo response for the original brand only. Expectations by subjects appear to be triggered not only by the placebo treatment itself but also by the trusted brand, which thus serves as an enhanced placebo. Both processes appear to be based on fronto-cortical neural networks, as these areas showed significantly stronger activations with the original brand. Wiley Periodicals, Inc.

  7. Standard Test Method for Electrical Performance of Concentrator Terrestrial Photovoltaic Modules and Systems Under Natural Sunlight

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method covers the determination of the electrical performance of photovoltaic concentrator modules and systems under natural sunlight using a normal incidence pyrheliometer. 1.2 The test method is limited to module assemblies and systems where the geometric concentration ratio specified by the manufacturer is greater than 5. 1.3 This test method applies to concentrators that use passive cooling where the cell temperature is related to the air temperature. 1.4 Measurements under a variety of conditions are allowed; results are reported under a select set of concentrator reporting conditions to facilitate comparison of results. 1.5 This test method applies only to concentrator terrestrial modules and systems. 1.6 This test method assumes that the module or system electrical performance characteristics do not change during the period of test. 1.7 The performance rating determined by this test method applies only at the period of the test, and implies no past or future performance level. 1.8...

  8. Standard Test Method for Electrical Performance of Photovoltaic Cells Using Reference Cells Under Simulated Sunlight

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method covers the determination of the electrical performance of a photovoltaic cell under simulated sunlight by means of a calibrated reference cell procedure. 1.2 Electrical performance measurements are reported with respect to a select set of standard reporting conditions (SRC) (see Table 1) or to user-specified conditions. 1.2.1 The SRC or user-specified conditions include the cell temperature, the total irradiance, and the reference spectral irradiance distribution. 1.3 This test method is applicable only to photovoltaic cells with a linear response over the range of interest. 1.4 The cell parameters determined by this test method apply only at the time of test, and imply no past or future performance level. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this s...

  9. Sunlight mediated seasonality in canopy structure and photosynthetic activity of Amazonian rainforests

    International Nuclear Information System (INIS)

    Bi, Jian; Knyazikhin, Yuri; Choi, Sungho; Park, Taejin; Barichivich, Jonathan; Ciais, Philippe; Fu, Rong; Ganguly, Sangram; Hall, Forrest; Hilker, Thomas; Huete, Alfredo; Jones, Matthew; Kimball, John; Lyapustin, Alexei I; Mõttus, Matti; Nemani, Ramakrishna R; Piao, Shilong; Poulter, Benjamin; Saleska, Scott R

    2015-01-01

    Resolving the debate surrounding the nature and controls of seasonal variation in the structure and metabolism of Amazonian rainforests is critical to understanding their response to climate change. In situ studies have observed higher photosynthetic and evapotranspiration rates, increased litterfall and leaf flushing during the Sunlight-rich dry season. Satellite data also indicated higher greenness level, a proven surrogate of photosynthetic carbon fixation, and leaf area during the dry season relative to the wet season. Some recent reports suggest that rainforests display no seasonal variations and the previous results were satellite measurement artefacts. Therefore, here we re-examine several years of data from three sensors on two satellites under a range of sun positions and satellite measurement geometries and document robust evidence for a seasonal cycle in structure and greenness of wet equatorial Amazonian rainforests. This seasonal cycle is concordant with independent observations of solar radiation. We attribute alternative conclusions to an incomplete study of the seasonal cycle, i.e. the dry season only, and to prognostications based on a biased radiative transfer model. Consequently, evidence of dry season greening in geometry corrected satellite data was ignored and the absence of evidence for seasonal variation in lidar data due to noisy and saturated signals was misinterpreted as evidence of the absence of changes during the dry season. Our results, grounded in the physics of radiative transfer, buttress previous reports of dry season increases in leaf flushing, litterfall, photosynthesis and evapotranspiration in well-hydrated Amazonian rainforests. (letter)

  10. Mycorrhiza symbiosis increases the surface for sunlight capture in Medicago truncatula for better photosynthetic production.

    Directory of Open Access Journals (Sweden)

    Lisa Adolfsson

    Full Text Available Arbuscular mycorrhizal (AM fungi play a prominent role in plant nutrition by supplying mineral nutrients, particularly inorganic phosphate (Pi, and also constitute an important carbon sink. AM stimulates plant growth and development, but the underlying mechanisms are not well understood. In this study, Medicago truncatula plants were grown with Rhizophagus irregularis BEG141 inoculum (AM, mock inoculum (control or with P(i fertilization. We hypothesized that AM stimulates plant growth through either modifications of leaf anatomy or photosynthetic activity per leaf area. We investigated whether these effects are shared with P(i fertilization, and also assessed the relationship between levels of AM colonization and these effects. We found that increased P(i supply by either mycorrhization or fertilization led to improved shoot growth associated with increased nitrogen uptake and carbon assimilation. Both mycorrhized and P(i-fertilized plants had more and longer branches with larger and thicker leaves than the control plants, resulting in an increased photosynthetically active area. AM-specific effects were earlier appearance of the first growth axes and increased number of chloroplasts per cell section, since they were not induced by P(i fertilization. Photosynthetic activity per leaf area remained the same regardless of type of treatment. In conclusion, the increase in growth of mycorrhized and P(i-fertilized Medicago truncatula plants is linked to an increase in the surface for sunlight capture, hence increasing their photosynthetic production, rather than to an increase in the photosynthetic activity per leaf area.

  11. Direct photolysis rates and transformation pathways of the lampricides TFM and niclosamide in simulated sunlight

    Science.gov (United States)

    McConville, Megan B.; Hubert, Terrance D.; Remucal, Christina K.

    2016-01-01

    The lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2′,5-dichloro-4′-nitrosalicylanilide (niclosamide) are directly added to many tributaries of the Great Lakes that harbor the invasive parasitic sea lamprey. Despite their long history of use, the fate of lampricides is not well understood. This study evaluates the rate and pathway of direct photodegradation of both lampricides under simulated sunlight. The estimated half-lives of TFM range from 16.6 ± 0.2 h (pH 9) to 32.9 ± 1.0 h (pH 6), while the half-lives of niclosamide range from 8.88 ± 0.52 days (pH 6) to 382 ± 83 days (pH 9) assuming continuous irradiation over a water depth of 55 cm. Both compounds degrade to form a series of aromatic intermediates, simple organic acids, ring cleavage products, and inorganic ions. Experimental data were used to construct a kinetic model which demonstrates that the aromatic products of TFM undergo rapid photolysis and emphasizes that niclosamide degradation is the rate-limiting step to dehalogenation and mineralization of the lampricide. This study demonstrates that TFM photodegradation is likely to occur on the time scale of lampricide applications (2–5 days), while niclosamide, the less selective lampricide, will undergo minimal direct photodegradation during its passage to the Great Lakes.

  12. Vitamin D, cod-liver oil, sunlight, and rickets: a historical perspective.

    Science.gov (United States)

    Rajakumar, Kumaravel

    2003-08-01

    Rickets, a disease of vitamin D deficiency, is rarely confronted by the practicing pediatrician in the United States today. At the turn of the 20th century, rickets was rampant among the poor children living in the industrialized and polluted northern cities of the United States. With the discovery of vitamin D and the delineation of the anti-rachitic properties of cod-liver oil by the 1930s, it became possible to not only treat but also eradicate rickets in the United States. Rickets was a common disease in 17th century England. Frances Glisson's treatise on rickets published in 1650, a glorious contribution to English medicine, described the clinical and anatomic features of rickets in great detail. The exact etiology of rickets had been elusive until the 1920s. During the Glissonian era, rickets was a mysterious disease. By the late 19th and early 20th century, faulty diet or faulty environment (poor hygiene, lack of fresh air and sunshine) or lack of exercise was implicated in its etiology. Animal experiments, appreciation of folklore advocating the benefits of cod-liver oil, and the geographical association of rickets to lack of sunshine were all relevant factors in the advancement of knowledge in the conquest of this malady. In this article, the history of rickets pertaining to the discovery of vitamin D, cod-liver oil, and sunlight is reviewed.

  13. Spectropolarimetric Measurements of Scattered Sunlight in the Huggins Bands: Retrieval of Tropospheric Ozone Profiles

    Science.gov (United States)

    Fu, D.; Sander, S. P.; Stutz, J.; Pongetti, T. J.; Yung, Y. L.; Wong, M.; Natraj, V.; Li, K.; Shia, R.

    2009-12-01

    Ozone concentrations in the troposphere have increased over the past century as a result of anthropogenic emissions of NOx and volatile organic compounds. In addition to being harmful to human health and plant life, ozone is an important greenhouse gas, especially in the middle and upper troposphere. Therefore, accurate monitoring of tropospheric ozone vertical distributions is crucial for a better understanding of air quality and climate change. Simulations of vector radiative transfer in the near ultraviolet region have shown that tropospheric ozone profiles can be retrieved using polarization measurements. However, to date there has been no experimental test of this method. A new compact, portable spectropolarimeter has been built for atmospheric remote sensing. The first comprehensive description of the configuration and performance of this instrument for ground-based operation is provided and sample atmospheric scattered sunlight spectra are shown. Using optimal estimation retrieval theory we study the information content of polarization spectra in the Huggins band and uncertainties in the retrieval associated with the measurement parameters, such as aerosol scattering.

  14. Mycorrhiza Symbiosis Increases the Surface for Sunlight Capture in Medicago truncatula for Better Photosynthetic Production

    Science.gov (United States)

    Adolfsson, Lisa; Keresztes, Áron; Uddling, Johan; Schoefs, Benoît; Spetea, Cornelia

    2015-01-01

    Arbuscular mycorrhizal (AM) fungi play a prominent role in plant nutrition by supplying mineral nutrients, particularly inorganic phosphate (Pi), and also constitute an important carbon sink. AM stimulates plant growth and development, but the underlying mechanisms are not well understood. In this study, Medicago truncatula plants were grown with Rhizophagus irregularis BEG141 inoculum (AM), mock inoculum (control) or with Pi fertilization. We hypothesized that AM stimulates plant growth through either modifications of leaf anatomy or photosynthetic activity per leaf area. We investigated whether these effects are shared with Pi fertilization, and also assessed the relationship between levels of AM colonization and these effects. We found that increased Pi supply by either mycorrhization or fertilization led to improved shoot growth associated with increased nitrogen uptake and carbon assimilation. Both mycorrhized and Pi-fertilized plants had more and longer branches with larger and thicker leaves than the control plants, resulting in an increased photosynthetically active area. AM-specific effects were earlier appearance of the first growth axes and increased number of chloroplasts per cell section, since they were not induced by Pi fertilization. Photosynthetic activity per leaf area remained the same regardless of type of treatment. In conclusion, the increase in growth of mycorrhized and Pi-fertilized Medicago truncatula plants is linked to an increase in the surface for sunlight capture, hence increasing their photosynthetic production, rather than to an increase in the photosynthetic activity per leaf area. PMID:25615871

  15. Direct Photolysis Rates and Transformation Pathways of the Lampricides TFM and Niclosamide in Simulated Sunlight.

    Science.gov (United States)

    McConville, Megan B; Hubert, Terrance D; Remucal, Christina K

    2016-09-20

    The lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2',5-dichloro-4'-nitrosalicylanilide (niclosamide) are directly added to many tributaries of the Great Lakes that harbor the invasive parasitic sea lamprey. Despite their long history of use, the fate of lampricides is not well understood. This study evaluates the rate and pathway of direct photodegradation of both lampricides under simulated sunlight. The estimated half-lives of TFM range from 16.6 ± 0.2 h (pH 9) to 32.9 ± 1.0 h (pH 6), while the half-lives of niclosamide range from 8.88 ± 0.52 days (pH 6) to 382 ± 83 days (pH 9) assuming continuous irradiation over a water depth of 55 cm. Both compounds degrade to form a series of aromatic intermediates, simple organic acids, ring cleavage products, and inorganic ions. Experimental data were used to construct a kinetic model which demonstrates that the aromatic products of TFM undergo rapid photolysis and emphasizes that niclosamide degradation is the rate-limiting step to dehalogenation and mineralization of the lampricide. This study demonstrates that TFM photodegradation is likely to occur on the time scale of lampricide applications (2-5 days), while niclosamide, the less selective lampricide, will undergo minimal direct photodegradation during its passage to the Great Lakes.

  16. Bleaching of the thermoluminescence of feldspars by selected wavelengths present in sunlight

    International Nuclear Information System (INIS)

    Robertson, G.B.; Prescott, J.R.; Hutton, J.T.

    1993-01-01

    Feldspars occur in many sediments, and dating them by thermoluminescence (TL) requires a knowledge of how efficiently sunlight bleaches these minerals. The relative bleaching efficiencies of various wavelengths have been investigated for four alkali feldspars and an oligoclase, using the natural TL of the samples and the artificial TL induced by laboratory irradiation, bleached by wavelengths in the range 322-550 nm. Ultraviolet wavelengths are more efficient than the longer wavelengths at bleaching all the glow-curve peaks and are responsible for most of the phototransfer from high-temperature peaks to low-temperature peaks. Some feldspars show an initial increase in TL intensity with bleaching. Two sanidines of similar bulk composition but different TL glow curves show different dependences on bleaching wavelength. In a sodic sanidine with a dominant 240 o C peak the energy required to bleach to 50% was a thousand times greater at 550 nm than at 322 nm. In contrast, another sanidine with a complex glow curve between 150 and 450 o C showed a much slower change in the 330 o C peak with wavelength - a factor of 10 between 322 and 550 nm - with a region between 400 and 500 nm which was almost independent of wavelength. This behaviour is explained by competing mechanisms of phototransfer and bleaching which depend on wavelength in different ways. (author)

  17. Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamdi, Abdullah M.; Sillanpää, Mika [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman)

    2015-01-05

    Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO{sub 2}:I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO{sub 2}:I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO{sub 2} nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO{sub 2} nanoparticles under similar illumination conditions.

  18. SASKTRAN: A spherical geometry radiative transfer code for efficient estimation of limb scattered sunlight

    International Nuclear Information System (INIS)

    Bourassa, A.E.; Degenstein, D.A.; Llewellyn, E.J.

    2008-01-01

    The inversion of satellite-based observations of limb scattered sunlight for the retrieval of constituent species requires an efficient and accurate modelling of the measurement. We present the development of the SASKTRAN radiative transfer model for the prediction of limb scatter measurements at optical wavelengths by method of successive orders along rays traced in a spherical atmosphere. The component of the signal due to the first two scattering events of the solar beam is accounted for directly along rays traced in the three-dimensional geometry. Simplifying assumptions in successive scattering orders provide computational optimizations without severely compromising the accuracy of the solution. SASKTRAN is designed for the analysis of measurements from the OSIRIS instrument and the implementation of the algorithm is efficient such that the code is suitable for the inversion of OSIRIS profiles on desktop computers. SASKTRAN total limb radiance profiles generally compare better with Monte-Carlo reference models over a large range of solar conditions than the approximate spherical and plane-parallel models typically used for inversions

  19. Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

    International Nuclear Information System (INIS)

    Al-Hamdi, Abdullah M.; Sillanpää, Mika; Dutta, Joydeep

    2015-01-01

    Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO 2 :I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO 2 :I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO 2 nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO 2 nanoparticles under similar illumination conditions

  20. Sunlight-charged electrochromic battery based on hybrid film of tungsten oxide and polyaniline

    Science.gov (United States)

    Chang, Xueting; Hu, Ruirui; Sun, Shibin; Liu, Jingrong; Lei, Yanhua; Liu, Tao; Dong, Lihua; Yin, Yansheng

    2018-05-01

    Electrochromic (EC) energy storage devices that could realize the multifunctional integration of energy storage and electrochromism have gained much recent attention. Herein, an EC battery based on the hybrid film of W18O49 and polyaniline (PANI) is developed and assembled, which integrates energy storage and EC functions in one device. The W18O49/PANI-EC battery delivers a discharging capacity of 52.96 mA h g-1, which is about two times higher than that of the W18O49-EC battery. Sunlight irradiation could greatly promote the oxidation reactions of both W18O49 and PANI during the charging process of the W18O49/PANI-EC battery, thus effectively accelerating the charging rate. This work provides a green, convenient, environmentally friendly, and cost-free charging strategy for the EC energy systems and could further advance the development of the multifunctional EC devices based on the organic/inorganic composites.

  1. ZnO-graphene quantum dots heterojunctions for natural sunlight-driven photocatalytic environmental remediation

    Science.gov (United States)

    Kumar, Suneel; Dhiman, Ankita; Sudhagar, Pitchaimuthu; Krishnan, Venkata

    2018-07-01

    In this work, we report the formation of heterojunctions comprising of graphene quantum dots (GQD) decorated ZnO nanorods (NR) and its use as efficient photocatalysts for environmental remediation. The heterojunctions has been designed to be active both in the UV and visible light regions and anticipated utilize the maximum part of the solar light spectrum. In this view, we examined the photocatalytic performance of our heterojunctions towards the degradation of colored pollutant (methylene blue (MB) dye) and a colorless pollutant (carbendazim (CZ) fungicide) under sunlight irradiation. Compared to bare photocatalyst ZnO and GQD, the heterojunction with 2 wt% of GQD (ZGQD2) showed the best photocatalytic activity by effectively degrading (about 95%) of organic pollutants (MB and CZ) from water within a short span of 70 min. The superior photocatalytic activity of these ZnO-GQD heterojunctions could be attributed to efficient charge carrier separation lead suppressed recombination rate at photocatalyst interfaces. In addition to the enhanced light absorption from UV to visible region, the high specific surface area of ZGQD2 heterojunction (353.447 m2 g-1) also imparts strong adsorption capacity for pollutants over catalyst surface, resulting in high photoactivity. Based on the obtained results, band gap alignment at ZnO-GQD heterojunction and active species trapping experiments, a plausible mechanism is proposed for photocatalytic reaction. The excellent photostability and recyclability of the ZnO-GQD heterojunctions fostering as promising photocatalyst candidate for environmental remediation applications.

  2. Hydrogen at the Rooftop: Compact CPV-Hydrogen system to Convert Sunlight to Hydrogen

    KAUST Repository

    Burhan, Muhammad

    2017-12-27

    Despite being highest potential energy source, solar intermittency and low power density make it difficult for solar energy to compete with the conventional power plants. Highly efficient concentrated photovoltaic (CPV) system provides best technology to be paired with the electrolytic hydrogen production, as a sustainable energy source with long term energy storage. However, the conventional gigantic design of CPV system limits its market and application to the open desert fields without any rooftop installation scope, unlike conventional PV. This makes CPV less popular among solar energy customers. This paper discusses the development of compact CPV-Hydrogen system for the rooftop application in the urban region. The in-house built compact CPV system works with hybrid solar tracking of 0.1° accuracy, ensured through proposed double lens collimator based solar tracking sensor. With PEM based electrolyser, the compact CPV-hydrogen system showed 28% CPV efficiency and 18% sunlight to hydrogen (STH) efficiency, for rooftop operation in tropical region of Singapore. For plant designers, the solar to hydrogen production rating of 217 kWh/kg has been presented with 15% STH daily average efficiency, recorded from the long term field operation of the system.

  3. Hydrogen at the Rooftop: Compact CPV-Hydrogen system to Convert Sunlight to Hydrogen

    KAUST Repository

    Burhan, Muhammad; Wakil Shahzad, Muhammad; Ng, Kim Choon

    2017-01-01

    Despite being highest potential energy source, solar intermittency and low power density make it difficult for solar energy to compete with the conventional power plants. Highly efficient concentrated photovoltaic (CPV) system provides best technology to be paired with the electrolytic hydrogen production, as a sustainable energy source with long term energy storage. However, the conventional gigantic design of CPV system limits its market and application to the open desert fields without any rooftop installation scope, unlike conventional PV. This makes CPV less popular among solar energy customers. This paper discusses the development of compact CPV-Hydrogen system for the rooftop application in the urban region. The in-house built compact CPV system works with hybrid solar tracking of 0.1° accuracy, ensured through proposed double lens collimator based solar tracking sensor. With PEM based electrolyser, the compact CPV-hydrogen system showed 28% CPV efficiency and 18% sunlight to hydrogen (STH) efficiency, for rooftop operation in tropical region of Singapore. For plant designers, the solar to hydrogen production rating of 217 kWh/kg has been presented with 15% STH daily average efficiency, recorded from the long term field operation of the system.

  4. The relationship between solar activity and the H and K line cores in integrated sunlight

    International Nuclear Information System (INIS)

    Jebsen, D.E.; Mitchell, W.E. Jr.

    1978-01-01

    In this paper the authors present and analyze new data on the cores of the H and K lines of ionized calcium in the spectrum of integrated sunlight. The intensities of the components Hsub(2γ), H 3 , Hsub(2r), Ksub(2γ), K 3 , and Ksub(2r) in the line cores were measured in terms of the continuum intensity at 4000 A during a solar rotation in September 1969. Other data on these components, obtained at or close to the time of solar minimum (September 1964) and solar maximum (September 1968), were also included. The intensities of these features are compared with two indices of solar activity: the Ca II plage index and the 2800 MHZ signal. The average correlation coefficients between the intensities of the measured features and those indices were 0.69 and 0.64, respectively. The results are consistent with those of Bumba and Ruzickova-Topolova (1967) for a solar rotation period in 1965. The method and results should provide a detailed quantitative basis for the study of the activity cycles and rotation periods of solar-type stars. (Auth.)

  5. 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.

  6. Examining the feasibility of converting New York State’s all-purpose energy infrastructure to one using wind, water, and sunlight

    International Nuclear Information System (INIS)

    Jacobson, Mark Z.; Howarth, Robert W.; Delucchi, Mark A.; Scobie, Stan R.; Barth, Jannette M.; Dvorak, Michael J.; Klevze, Megan; Katkhuda, Hind; Miranda, Brian; Chowdhury, Navid A.; Jones, Rick; Plano, Larsen; Ingraffea, Anthony R.

    2013-01-01

    This study analyzes a plan to convert New York State's (NYS's) all-purpose (for electricity, transportation, heating/cooling, and industry) energy infrastructure to one derived entirely from wind, water, and sunlight (WWS) generating electricity and electrolytic hydrogen. Under the plan, NYS's 2030 all-purpose end-use power would be provided by 10% onshore wind (4020 5-MW turbines), 40% offshore wind (12,700 5-MW turbines), 10% concentrated solar (387 100-MW plants), 10% solar-PV plants (828 50-MW plants), 6% residential rooftop PV (∼5 million 5-kW systems), 12% commercial/government rooftop PV (∼500,000 100-kW systems), 5% geothermal (36 100-MW plants), 0.5% wave (1910 0.75-MW devices), 1% tidal (2600 1-MW turbines), and 5.5% hydroelectric (6.6 1300-MW plants, of which 89% exist). The conversion would reduce NYS's end-use power demand ∼37% and stabilize energy prices since fuel costs would be zero. It would create more jobs than lost because nearly all NYS energy would now be produced in-state. NYS air pollution mortality and its costs would decline by ∼4000 (1200–7600) deaths/yr, and $33 (10–76) billion/yr (3% of 2010 NYS GDP), respectively, alone repaying the 271 GW installed power needed within ∼17 years, before accounting for electricity sales. NYS's own emission decreases would reduce 2050 U.S. climate costs by ∼$3.2 billion/yr. - Highlights: ► New York State's all-purpose energy can be derived from wind, water, and sunlight. ► The conversion reduces NYS end-use power demand by ∼37%. ► The plan creates more jobs than lost since most energy will be from in state. ► The plan creates long-term energy price stability since fuel costs will be zero. ► The plan decreases air pollution deaths 4000/yr ($33 billion/yr or 3% of NYS GDP)

  7. Evidence for Alteration in Chemical and Physical Properties of Water and Modulation of its Biological Functions by Sunlight Transmitted through Color Ranges of the Visible Spectrum-A Novel Study

    Directory of Open Access Journals (Sweden)

    M. Rajeswara Rao

    2005-08-01

    Full Text Available We investigated the changes in the properties of water when exposed to sunlight for 40 days. We hypothesize and prove that solar irradiation to water entraps electromagnetic radiation as potential energy, which becomes kinetic energy in various systems. It is postulated that photochemically-induced energy transfers, associated with individual spectral emission of visible spectrum of solar light, exert diverse influences on biological systems. Bottles of distilled water, individually wrapped in spectral-colored cellophane were exposed to sunlight and compared to an unwrapped bottle to determine chemical and physical changes as well as modifications of biological properties. Each bottle of water was named according to the color of cellophane paper with letter E (stands for exposed as a prefix with (E-violet, E-indigo, E-blue, E-green, E-yellow, E-orange, and Ered. E-control (without wrap was exposed to polychromatic sunlight. This study addresses two main issues viz., the chemical and physical changes in E-water and its effect on biological activities. Chemical and physical composition analysis using inductively coupled plasma atomic emission spectrometry; physical conductance by a Wheatstone Bridge type conductivity meter; osmolarity by a vapor pressure osmometer; and, salt solubility profile of 10% sodium bicarbonate were determined. Furthermore, testing the effect of E-waters on human lymphocyte proliferation, mosquito larvae hatching and seed germination determined the functional role of solar radiation through specific spectrum/s of visible light on various biological processes. We found that water exposed to visible spectral emissions of sunlight had an altered elemental composition, electrical conductance, osmolarity and salt-solubility, as well as differences in bio-modulatory effects. A gradual increase in leaching of Boron from Eviolet to E-red was noted. E-indigo showed maximal increase in electrical conductance and maximal salt

  8. Sunlight-Driven Forging of Amide/Ester Bonds from Three Independent Components: An Approach to Carbamates.

    Science.gov (United States)

    Zhao, Yating; Huang, Binbin; Yang, Chao; Chen, Qingqing; Xia, Wujiong

    2016-11-04

    A photoredox catalytic route to carbamates enabled by visible irradiation (or simply sunlight) has been developed. This process leads to a novel approach to the construction of heterocyclic rings wherein the amide or ester motifs of carbamates were assembled from three isolated components. Large-scale experiments were realized by employing continuous flow techniques, and reuse of photocatalyst demonstrated the green and sustainable aspects of this method.

  9. Morphology-controlled electrodeposition of Cu2O microcrystalline particle films for application in photocatalysis under sunlight

    International Nuclear Information System (INIS)

    Wu, Guodong; Zhai, Wei; Sun, Fengqiang; Chen, Wei; Pan, Zizhao; Li, Weishan

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► PEG was used to electro-deposit Cu 2 O microcrystalline particle films. ► Morphologies of Cu 2 O microcrystals could be controlled by the amount of PEG. ► The films showed regularly varied photocatalytic activities under sunlight. ► The films could be recycled and showed stable activities. -- Abstract: Morphology-controlled Cu 2 O microcrystalline particle films had been successfully electrodeposited on tin-doped indium oxide glass substrates in CuSO 4 solutions containing different amounts of polyethylene glycol (PEG) additives. With an increase of PEG, microcrystals gradually changed from irregular shapes to cubes, octahedrons, and spherical shapes. Sizes increasingly became smaller with an increase of PEG under the same deposition time. These films had been first used as recyclable photocatalysts and showed excellent and photocatalytic activities in photodegradation of methylene blue (MB) under sunlight. Activities were regularly varied relative to the morphologies of films controlled by the amount of PEG and could be further enhanced by adding a little amount of hydrogen peroxide in the MB solution. The method for controllable preparation of Cu 2 O microcrystals with photocatalytic activities was simple and inexpensive. The as-prepared particle films could also be used in photodegradation of many other pollutants under sunlight.

  10. Heat engine development for solar thermal power systems

    Science.gov (United States)

    Pham, H. Q.; Jaffe, L. D.

    The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

  11. Dietary intakes of expeditioners during prolonged sunlight deprivation in polar enviroments do not support bone health.

    Science.gov (United States)

    Iuliano, Sandra; Ayton, Jeff

    2015-01-01

    Background Early Antarctic expeditions were plagued by nutrient deficiencies, due to lack of fresh food and reliance on preserved foods. Modern Antarctic expeditioners also require provisions to be shipped in, but improved knowledge and storage options ensure foods are nutritionally sound. Despite this, nutritional imbalances are observed. Objectives To determine the adequacy of dietary intake of Antarctic expeditioners, with reference to bone health. Design Dietary intake was determined on 225 adults (mean age 42±11 years, 16% female) during 12-month deployments at Australian Antarctic stations from 2004 to 2010, using weighed 3-day food records. Nutrient intake was analysed using FoodWorks. Foods were divided into the 5 food groups according to the Australian Guide to Healthy Eating. Results Men consumed below the recommended levels [recommended daily intake (RDI)/adequate intakes (AI)] of calcium (79±42% of RDI, p<0.001), magnesium (83±34% of RDI, p<0.001), potassium (86±29% of AI, p<0.001) and fibre (75±30% of AI, p<0.001), and above the upper limit (UL) for sodium (125±48% of UL p<0.001), whereas women consumed below the recommended levels of calcium (68±21% of RDI, p<0.001) and iron (73±37% of RDI, p<0.001). Vitamin D intake is not substantial (<150 IU/d). Men consumed more alcohol than women (18±24 g/d vs. 10±13 g/d, p<0.05), nearer the guideline of ≤20 g/d. Men and women consumed approximately 1 serving of dairy food per day, and 3 of 5 recommended vegetable servings. Discretionary foods were consumed in excess of recommended. Conclusions Improving consumption of calcium-rich (dairy) foods better supports bone health during sunlight deprivation. Increasing vegetable intake to recommended levels will increase fibre, potassium and magnesium intakes. The challenge is the logistics of providing these foods throughout the year.

  12. Enhanced photocatalytic degradation of dyes under sunlight using biocompatible TiO2 nanoparticles

    Science.gov (United States)

    Bharati, B.; Sonkar, A. K.; Singh, N.; Dash, D.; Rath, Chandana

    2017-08-01

    As TiO2 is one of the most popular photocatalysts, we have studied here the photocatalytic degradation of the most common dyestuffs like rhodamine B (RhB), congo red (CR) and methylene blue (MB), which mainly come from the textile and photographic industries using nanoparticles of TiO2. Nanoparticles of TiO2 synthesized through a simple and cost effective sol-gel technique crystallizes in the anatase phase, showing a band gap less than that of bulk value. Particles consisting of coherently scattered domains of size 33 nm are found to be agglomerated and polycrystalline in nature. While the degradation rates of MB, CR and RhB after irradiating with a renewable source of energy, i.e. sunlight, show 100% degradation, TiO2 irradiated with UV light of 4.8 eV shows a much slower degradation rate. To use the waste water after photocatalysis, we examine further the biocompatibile nature of the TiO2 nanoparticles by platelet interaction activity, hemolysis effect and MTT assay. It is worth mentioning here that TiO2 nanoparticles are found to be highly hemocompatible, show no platelet aggregation, and the level of intracellular ROS in human platelets does not show significant change in ROS level. We conclude that TiO2 nanoparticles constitute an excellent photocatalyst and biocompatible material, and that after photocatalytic degradation of dye effluents obtained from textile industries, purified water can be used in agriculture and domestic sectors.

  13. Antiradical capacity and polyphenol composition of asparagus spears varieties cultivated under different sunlight conditions.

    Science.gov (United States)

    Kulczyński, Bartosz; Kobus-Cisowska, Joanna; Kmiecik, Dominik; Gramza-Michałowska, Anna; Golczak, Dorota; Korczak, Józef

    2016-01-01

    Asparagus officinalis has a high nutritional value. Asparagus is rich in a number of bioactive compounds, mainly flavonoids (quercetin), glutathione, vitamin C, vitamin E, fructans (inulin and fructooligosaccharides) and phytosterols (b-sitosterol). These compounds may play an important role in human health. The purpose of this study was to examine the antioxidant potential and polyphenol composition of white, pale-colored and green asparagus spears of different cultivars. Investigations were conducted on different asparagus spear extracts. The study included three colors of asparagus (white, pale-colored and green) from five different cultivars subjected to the ethanol extraction procedure. Total phenolic content was also determined by the Folin-Ciocalteu method. Polyphenol (phenolic acids and flavonols) composition was estimated using the HPLC method. The antioxidant properties of extracts were examined using DPPH, ABTS and metal ion chelating assays. The highest contents of phenolic and flavonoids were observed in green asparagus from Grolim and the lowest in pale-colored asparagus from Gyjmlin. It was found that both the color of asparagus and the cultivar had a significant effect on the composition of phenolic acid and flavonols. Radical scavenging activity toward DPPH• and ABTS was highest for green asparagus cv. Grolim and Eposs. The greatest number of Fe ions was chelated by samples of green asparagus cv. Grolim and Huchel's Alpha and pale-colored asparagus cv. Huchel's Alpha. It was shown that the antioxidant activity of asparagus spears measured by antiradical and chelating activity test depends on variety and color. The highest activity was found in green asparagus and the lowest was identified in white asparagus extracts. It has also been clarified that changes in flavonol and phenolic acid composition and increases in their diversity depends on growing with sunlight and variety. Asparagus can provide a valuable source of phenolic compounds in the

  14. A practical demonstration of water disinfection using TiO2 films and sunlight.

    Science.gov (United States)

    Gelover, Silvia; Gómez, Luis A; Reyes, Karina; Teresa Leal, Ma

    2006-10-01

    The scope of this study is the assessment of the efficiency of solar disinfection by heterogeneous photocatalysis with sol-gel immobilized (titanium dioxide) TiO2 films over glass cylinders. The solar disinfection process known as SODIS was considered as a reference. Spring water naturally polluted with coliform bacteria was exposed to sunlight in plastic bottles with and without TiO2 over simple solar collectors and the disinfection effectiveness was measured. Total and fecal coliforms quantification was performed by means of the chromogenic substrate method in order to obtain the efficiency of each disinfection treatment. The disinfection with TiO2 was more efficient than the SODIS process, inactivating total coliforms as well as fecal coliforms. On a sunny day (more than 1000 W m(-2) irradiance), it took the disinfection with immobilized TiO2 15 min of irradiation to inactivate the fecal coliforms to make them undetectable. For inactivation of total coliforms, 30 min was required, so that in less than half the time it takes SODIS, the treated water complies with the microbial standards for drinking water in Mexico. Another important part of this study has been to determine the bacterial regrowth in water after the disinfection processes were tested. After SODIS, bacterial regrowth of coliforms was observed. In contrast, when using the TiO2 catalyst, coliforms regrowth was not detected, neither for total nor for fecal coliforms. The disinfection process using TiO2 kept treated water free of coliforms at least for seven days after sun irradiation. This demonstration opens the possibility of application of this simple method in rural areas of developing countries.

  15. Reusable sunlight activated photocatalyst Ag3PO4 and its significant antibacterial activity

    International Nuclear Information System (INIS)

    Thiyagarajan, Shankar; Singh, Sarika; Bahadur, D.

    2016-01-01

    A simple and surfactant free soft chemical approach is adopted for the successful synthesis of Ag 3 PO 4 nanoparticles (NPs) at room temperature. The obtained Ag 3 PO 4 NPs are nearly spherical in shape with a size of 250 ± 50 nm. These NPs are highly efficient for the degradation of three organic dyes (methylene blue, rhodamine B and methyl orange) under four different types of light sources. In this case, the superior photocatalytic activity is mainly driven by singlet oxygen radicals and it is confirmed through the electron spin resonance (ESR) spin trapping technique, using several quenchers/sources. Notably, these NPs have the ability to absorb large portion of solar spectrum and therefore it displays higher efficiency under sunlight as compared to UV-C light and a 60 W household compact fluorescence lamp (CFL). Furthermore, these NPs exhibit excellent colloidal stability and recycling capability for the degradation of dyes. In addition, it possesses significant antibacterial activity with complete inhibition of bacterial pathogen, Escherichia coli at a very low concentration (0.01 mg/mL) after a mere 15 min of incubation time. The inhibition of bacterial growth is also suggested from the generation of intracellular reactive oxygen species (ROS) in E. coli by fluorescence microscopy. Thus, these NPs may provide a potential outcome for the environmental remediation. - Graphical abstract: Schematic representation of the mechanism involved in photodegradation of organic dyes and inhibition of bacterial growth using Ag 3 PO 4 nanoparticles. - Highlights: • Excellent catalytic activity for dyes degradation under different light sources. • Mechanism involving catalyst mediated ROS generation in photocatalysis suggested. • Good recycling capability of Ag 3 PO 4 even after the fifth cycles. • Extraordinary antibacterial activity of Ag 3 PO 4 after a very short incubation time. • Detection of intracellular ROS in bacterial cells by fluorescence

  16. Heat transport and solar transmission through a window system with low-emitting coatings

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, B; Ribbing, C G

    1977-12-01

    Heat transfer processes through a double-glazed window system are examined. Network calculations show the good insulation properties of a double-glazed window system including at least one low-emitting film. When the insolation is taken into consideration, absorption in the panes change the heat-balance and a heat-transfer coefficient can not be defined. The thermal and optical properties of windows with low-emitting metallic films are investigated. These windows depress the heat-losses but show a relatively low solar transmission. They are suitable for reducing intense sunlight during the summer period, together with good thermal insulation during periods with low insolation.

  17. 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

  18. Heat transfer

    International Nuclear Information System (INIS)

    Saad, M.A.

    1985-01-01

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

  19. 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...

  20. Heat exchanger

    Science.gov (United States)

    Daman, Ernest L.; McCallister, Robert A.

    1979-01-01

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

  1. Genome-Wide Transcriptional Profiles of the Berry Skin of Two Red Grape Cultivars (Vitis vinifera) in Which Anthocyanin Synthesis Is Sunlight-Dependent or -Independent

    Science.gov (United States)

    Guan, Le; Xin, Hai-Ping; Li, Ji-Hu; Li, Shao-Hua

    2014-01-01

    Global gene expression was analyzed in the berry skin of two red grape cultivars, which can (‘Jingyan’) or cannot (‘Jingxiu’) synthesize anthocyanins after sunlight exclusion from fruit set until maturity. Gene transcripts responding to sunlight exclusion in ‘Jingyan’ were less complex than in ‘Jingxiu’; 528 genes were induced and 383 repressed in the former, whereas 2655 genes were induced and 205 suppressed in ‘Jingxiu’. They were regulated either in the same or opposing manner in the two cultivars, or in only one cultivar. In addition to VvUFGT and VvMYBA1, some candidate genes (e.g. AOMT, GST, and ANP) were identified which are probably involved in the differential responses of ‘Jingxiu’ and ‘Jingyan’ to sunlight exclusion. In addition, 26 MYB, 14 bHLH and 23 WD40 genes responded differently to sunlight exclusion in the two cultivars. Interestingly, all of the 189 genes classified as being relevant to ubiquitin-dependent protein degradation were down-regulated by sunlight exclusion in ‘Jingxiu’, but the majority (162) remained unchanged in ‘Jingyan’ berry skin. It would be of interest to determine the precise role of the ubiquitin pathway following sunlight exclusion, particularly the role of COP9 signalosome, cullins, RING-Box 1, and COP1-interacting proteins. Only a few genes in the light signal system were found to be regulated by sunlight exclusion in either or both cultivars. This study provides a valuable overview of the transcriptome changes and gives insight into the genetic background that may be responsible for sunlight-dependent versus -independent anthocyanin biosynthesis in berry skin. PMID:25158067

  2. An analysis of factors that influence personal exposure to toluene and xylene in residents of Athens, Greece

    Directory of Open Access Journals (Sweden)

    Linos Athena

    2006-02-01

    Full Text Available Abstract Background Personal exposure to pollutants is influenced by various outdoor and indoor sources. The aim of this study was to evaluate the exposure of Athens citizens to toluene and xylene, excluding exposure from active smoking. Methods Passive air samplers were used to monitor volunteers, their homes and various urban sites for one year, resulting in 2400 measurements of toluene and xylene levels. Since both indoor and outdoor pollution contribute significantly to human exposure, volunteers were chosen from occupational groups who spend a lot of time in the streets (traffic policemen, bus drivers and postmen, and from groups who spend more time indoors (teachers and students. Data on individual and house characteristics were obtained using a questionnaire completed at the beginning of the study; a time-location-activity diary was also completed daily by the volunteers in each of the six monitoring campaigns. Results Average personal toluene exposure varied over the six monitoring campaigns from 53 to 80 μg/m3. Urban and indoor concentrations ranged from 47 – 84 μg/m3 and 30 – 51 μg/m3, respectively. Average personal xylene exposure varied between 56 and 85 μg/m3 while urban and indoor concentrations ranged from 53 – 88 μg/m3 and 27 – 48 μg/m3, respectively. Urban pollution, indoor residential concentrations and personal exposures exhibited the same pattern of variation during the measurement periods. This variation among monitoring campaigns might largely be explained by differences in climate parameters, namely wind speed, humidity and amount of sunlight. Conclusion In Athens, Greece, the time spent outdoors in the city center during work or leisure makes a major contribution to exposure to toluene and xylene among non-smoking citizens. Indoor pollution and means of transportation contribute significantly to individual exposure levels. Other indoor residential characteristics such as recent painting and mode of heating

  3. Seca da semente de café ao sol Effect of sunlight on coffee seed viability

    Directory of Open Access Journals (Sweden)

    Oswaldo Bacchi

    1955-01-01

    Full Text Available O presente trabalho diz respeito a estudos realizados com o objetivo de observar a influência da luz solar sôbre a capacidade germinativa da semente despolpada de café e verificar, portanto, a possibilidade de se efetuar a seca desta semente exclusivamente ao sol. Além de um ensaio preliminar, foram efetuados mais outros dois, compreendendo, ao todo, duas secas ao sol, duas em um secador a baixa temperatura (±28°C, uma a sombra e uma em um secador a alta temperatura (±40°C. Pelas correlações entre as porcentagens de germinação e de umidade, que foram estabelecidas após diferentes períodos de secagem, foram tiradas as duas seguintes conclusões, que são as principais com relação ao objetivo dêstes ensaios : 1 Os raios solares são prejudiciais à capacidade germinativa da semente de café; sua nocividade acha-se, porém, intimamente ligada ao teor de umidade na semente. 2 À vista da conclusão acima, verifica-se que a semente despolpada de café e, muito provavelmente, também a não despolpada, podem ser perfeitamente sêcas a pleno sol sem que haja prejuízo para sua vitalidade, uma vez que sejam recolhidas antes que o seu teor de umidade caia abaixo do ponto crítico de 8% - 9%.In this paper the author deals with the question related to the coffee seed drying, with special attention to the effect of the sun radiations on seed viability. Based on the results obtained, the following conclusions were drawn : (a The sun rays have no specific influence on the viability of hulled coffee seed ; their effect is indirect and related to loss of moisture by the seed. (b Coffee seed can be dried in the sunlight without loss of viability if the water content does not drop under 8% to 9%. Below this critical level seed germination falls rapidly. (c The moisture content of coffee seed dried „in the sun may fall to about 7% in a short time with the consequent injury to viability. (d Under most conditions in the state of São Paulo

  4. Dietary intakes of expeditioners during prolonged sunlight deprivation in polar enviroments do not support bone health

    Directory of Open Access Journals (Sweden)

    Sandra Iuliano

    2015-08-01

    Full Text Available Background: Early Antarctic expeditions were plagued by nutrient deficiencies, due to lack of fresh food and reliance on preserved foods. Modern Antarctic expeditioners also require provisions to be shipped in, but improved knowledge and storage options ensure foods are nutritionally sound. Despite this, nutritional imbalances are observed. Objectives: To determine the adequacy of dietary intake of Antarctic expeditioners, with reference to bone health. Design: Dietary intake was determined on 225 adults (mean age 42±11 years, 16% female during 12-month deployments at Australian Antarctic stations from 2004 to 2010, using weighed 3-day food records. Nutrient intake was analysed using FoodWorks. Foods were divided into the 5 food groups according to the Australian Guide to Healthy Eating. Results: Men consumed below the recommended levels [recommended daily intake (RDI/adequate intakes (AI] of calcium (79±42% of RDI, p<0.001, magnesium (83±34% of RDI, p<0.001, potassium (86±29% of AI, p<0.001 and fibre (75±30% of AI, p<0.001, and above the upper limit (UL for sodium (125±48% of UL p<0.001, whereas women consumed below the recommended levels of calcium (68±21% of RDI, p<0.001 and iron (73±37% of RDI, p<0.001. Vitamin D intake is not substantial (<150 IU/d. Men consumed more alcohol than women (18±24 g/d vs. 10±13 g/d, p<0.05, nearer the guideline of ≤20 g/d. Men and women consumed approximately 1 serving of dairy food per day, and 3 of 5 recommended vegetable servings. Discretionary foods were consumed in excess of recommended. Conclusions: Improving consumption of calcium-rich (dairy foods better supports bone health during sunlight deprivation. Increasing vegetable intake to recommended levels will increase fibre, potassium and magnesium intakes. The challenge is the logistics of providing these foods throughout the year.

  5. Heat pipe

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  6. Rapid charging of thermal energy storage materials through plasmonic heating.

    Science.gov (United States)

    Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

    2014-09-01

    Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites.

  7. Using Microporous Polytetrafluoroethylene Thin Sheets as a Flexible Solar Diffuser to Minimize Sunlight Glint to Cameras in Space

    Science.gov (United States)

    Choi, Michael K.

    2016-01-01

    An innovative design of using microporous PTFE thin sheets as a solar diffuser for MLI blankets or mechanical structure has been developed. It minimizes sunlight or stray-light glint to cameras when it is incident on these components in space. A microporous black PTFE thin sheet solar diffuser has been qualified for flight at NASA GSFC and installed to the TAGSAM arm MLI, OCAMS PolyCam sunshade MLI and SamCam motor riser MLI in the NASA OSIRIS-REx mission to meet the SamCam camera BRDF requirement.

  8. Aromatic/heterocyclic amino acids and the simulated sunlight-ultraviolet inactivation of the Heliothis/Helicoverpa baculovirus

    International Nuclear Information System (INIS)

    Ignoffo, C.M.; Garcia, C.

    1995-01-01

    Tryptophan, of five aromatic/heterocyclic amino acids (tyrosine, phenylalanine, proline, histidine) provided significant protection of the Heliothis baculovirus (HzSNPV) from inactivation by simulated ultraviolet (SUV). Fifty percent of SUV protection of HzSNPV with tryptophan or tyrosine was obtained at 0.03 mg/ml and 0.5 mg/ml, respectively. Rates as high as 100.0 mg/ml of phenylalanine, histidine, or proline provided <50% protection. The extent of tryptophan protection was correlated with its absorption in the sunlight UV-B spectra. 16 refs., 2 tabs

  9. Using microporous polytetrafluoroethylene thin sheets as a flexible solar diffuser to minimize sunlight glint to cameras in space

    Science.gov (United States)

    Choi, Michael K.

    2016-09-01

    An innovative design of using microporous PTFE thin sheets as a solar diffuser for MLI blankets or mechanical structure has been developed. It minimizes sunlight or stray-light glint to cameras when it is incident on these components in space. A microporous black PTFE thin sheet solar diffuser has been qualified for flight at NASA GSFC and installed to the TAGSAM arm MLI, OCAMS PolyCam sunshade MLI and SamCam motor riser MLI in the NASA OSIRIS-REx mission to meet the SamCam camera BRDF requirement.

  10. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    Science.gov (United States)

    Rijal, G K; Fujioka, R S

    2001-01-01

    Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective disinfection was observed even when the water temperature did not reach 60 degrees C. Finally, the hydrogen sulphide test is a simple and reliable test that householders can use to determine whether their water had been sufficiently disinfected.

  11. THE INFLUENCE OF SUNLIGHT AND WIND ON THE POLYCRYSTALLINE SILICON MODULES

    Directory of Open Access Journals (Sweden)

    Piotr Lichograj

    2016-12-01

    Full Text Available Changing conditions have a significant impact on the efficiency and durability of photovoltaic cells. On photovoltaic modules have also influence such external factors as temperature of the module, which changes during the long exposure to light radiation, wind, pollution and the frequency of rainfall. Parameters of PV modules provided by the manufacturers differ significantly from the results achieved under natural conditions. This work presents the laboratory study on the impact of temperature of the polycrystalline silicon module to the change of generated voltage tested with no load. Research confirms the correlation of temperature increase during the long exposure to light radiation with a voltage drop. At the same time simulation of wind causes the cooling of the module and increase the voltage circuit. Further development of research on the effects of environmental conditions will allow for accurate placement optimization of photovoltaic farms.

  12. Solar passive ceiling system. Final report. [Passive solar heating system with venetian blind reflectors and latent heat storage in ceiling

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, A.R.

    1980-01-01

    The construction of a 1200 square foot building, with full basement, built to be used as a branch library in a rural area is described. The primary heating source is a passive solar system consisting of a south facing window system. The system consists of: a set of windows located in the south facing wall only, composed of double glazed units; a set of reflectors mounted in each window which reflects sunlight up to the ceiling (the reflectors are similar to venetian blinds); a storage area in the ceiling which absorbs the heat from the reflected sunlight and stores it in foil salt pouches laid in the ceiling; and an automated curtain which automatically covers and uncovers the south facing window system. The system is totally passive and uses no blowers, pumps or other active types of heat distribution equipment. The building contains a basement which is normally not heated, and the north facing wall is bermed four feet high around the north side.

  13. Sunlight-driven eco-friendly smart curtain based on infrared responsive graphene oxide-polymer photoactuators.

    Science.gov (United States)

    Leeladhar; Raturi, Parul; Singh, J P

    2018-02-27

    Photomechanical actuation is the conversion of light energy into mechanical energy through some smart materials. Infrared-responsive smart materials have become an emerging field of research due to easy availability and eco-friendly nature of their stimulus in the form of sunlight, which contains about 50% of near-infrared(nIR) making these materials useful at macro-scale photoactuator applications. Here, we demonstrate fabrication of highly versatile nIR triggered photoactuators based on graphene oxide/polycarbonate bilayers that offers fast, low-cost fabrication, large deflection, reversible actuation and wavelength-selective response. The photoactuators are realized by vacuum filtration of graphene oxide/water dispersion through polycarbonate membrane resulting graphene oxide/polymer bilayer structure. The photoactuation response was measured in the form of deflection from equilibrium position as a result of infrared-irradiation. The deflection is caused by the generated thermal stress at the interface of bilayers due to mismatch of thermal expansion coefficient as a results of nIR absorption by graphene oxide and subsequent temperature rise. A maximum deflection of 12 mm (circular-shaped structure with diameter 28 mm) with corresponding bending curvature of 0.33 cm -1 was shown by this photoactuator for illumination intensity of 106 mW/cm 2 . Few applications of these photoactuators such as sunlight-driven smart curtain, infrared actuated curtain and self-folding box are also demonstrated.

  14. Sunlight Triggers Cutaneous Lupus through a Colony Stimulating Factor-1 (CSF-1) Dependent Mechanism in MRL-Faslpr mice

    Science.gov (United States)

    Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T.; Lucas, Julie A.; Rabacal, Whitney A.; Croker, Byron P.; Zong, Xiao-Hua; Stanley, E. Richard; Kelley, Vicki R.

    2008-01-01

    Sunlight (UVB) triggers cutaneous (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø) -mediated mechanism in MRL-Faslpr mice. By constructing mutant MRL-Faslpr strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex-vivo gene transfer to deliver CSF-1 intra-dermally, we determined that CSF-1 induces CLE in lupus-susceptible, MRL-Faslpr mice, but not in lupus-resistant, BALB/c mice. Notably, UVB incites an increase in Mø, apoptosis in the skin and CLE in MRL-Faslpr, but not in CSF-1-deficient MRL-Faslpr mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Mø that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Faslpr, but not lupus-resistant BALB/c mice. Taken together, we envision CSF-1 as the “match” and lupus-susceptibility as the “tinder” leading to CLE. PMID:18981160

  15. Heat exchanger

    International Nuclear Information System (INIS)

    Leigh, D.G.

    1976-01-01

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

  16. Direct Heat

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P J

    1990-01-01

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

  17. Plasma heating

    International Nuclear Information System (INIS)

    Wilhelm, R.

    1989-01-01

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

  18. Heat Stroke

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  19. Effect of sunlight radiation, rainfall and droplet spectra of sprays on persistence of Bacillus thuringiensis deposits after application of DiPel 76AF formulation onto conifers

    International Nuclear Information System (INIS)

    Sundaram, A.; Sundaram, K.M.S.

    1996-01-01

    The Effect of sunlight radiation, rainfall and droplet spectra of sprays on per ‐sistence of a Bacillus thuringiensis subspp. kurstaki (Btk) formulation, DiPel? 76AF, was examined after application onto spruce [Picea glauca (Moench) Voss] foliage. The investigation consisted of three studies: (i) Study I: a laboratory microcosm study to examine the photostability of DiPel 76AF deposits on foliage after different periods of exposure to two radiation intensities, (ii) Study II: a laboratory microcosm study to examine the rainfastness of foliar deposits after exposure to different amounts of rainfall consisting of two separate droplet spectra, and (iii) Study III: a field microcosm study to investigate the influence of two different droplet spectra of DiPel 76AF sprays on foliar persistence of Btk under natural weathering conditions. In all studies, persistence of Btk was investigated both by bioassay [using spruce budworm (Choristoneura fumiferana Clemens)] and total protein assay.The findings of Study I indicated that bioactivity of foliar deposits decreased with increasing duration of exposure to radiation, and with increasing radiation intensity. The half‐life (DT 50 , the exposure period required for 50% of the initial bioactivity to disappear) was 5.1 d for the low intensity, and 3.9 d for the higher intensity. In contrast with the bioassay results, the total protein levels [determined by the bicinchoninic acid (BCA) method] showed no decrease with increasing duration of exposure, or with increasing radiation intensity.The findings of Study II indicated that bioactivity of foliar deposits decreased with increasing cumulative rainfall. A new term, RF 50 [the amount of rain (in mm) required to washoff 50% of the initial deposit], was introduced to understand the relationship between rainfall intensity and reduction in bioactivity. When the same amount of rain was applied in different droplet sizes, the RF 50 value was high (5.2 mm) for the small rain droplets

  20. 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

  1. Heat conduction

    International Nuclear Information System (INIS)

    Grigull, U.; Sandner, H.

    1984-01-01

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

  2. Gene expression of Escherichia coli in continuous culture during adaptation to artificial sunlight.

    Science.gov (United States)

    Berney, Michael; Weilenmann, Hans-Ulrich; Egli, Thomas

    2006-09-01

    Escherichia coli growing in continuous culture under continuous UVA irradiation exhibits growth inhibition with a subsequent adaptation to the stress. Transcriptome analysis was performed during transient growth inhibition and in the UVA light-adapted growth state. The results indicate that UVA light induces stringent response and an additional response that includes the upregulation of the synthesis of valine, isoleucine, leucine, phenylalanine, histidine and glutamate. The induction of several SOS response-genes strongly points to DNA damage as a result of UVA exposure. The involvement of oxidative stress was observed with the induction of ahpCF. Taken together it supports the hypothesis of the production of reactive oxygen species by UVA light. In the UVA-adapted cell population strong repression of the acid tolerance response was found. We identified the enzyme chorismate mutase as a possible chromophore for UVA light-inactivation and found strong repression of the pyrBI operon and the gene mgtA encoding for an ATP-dependent Mg2+ transporter. Furthermore, our results indicate that the role of RpoS may not be as important in the adaptation of E. coli to UVA light as it was implicated by previous results with starved cells, but that RpoS might be of crucial importance for the resistance under transient light exposure.

  3. Human cell transformation in the study of sunlight-induced cancers in the skin of man

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Bennett, P.V.

    1988-01-01

    Human cell transformation provides a powerful approach to understanding - at the cellular and molecular levels - induction of cancers in the skin of man. A principal approach to this problem is the direct transformation of human skin cells by exposure to ultraviolet and/or near-UV radiation. The frequency of human cells transformed to anchorage independence increases with radiation exposure; the relative transforming efficiencies of different wavelengths implies that direct absorption by nucleic acids is a primary initial event. Partial reversal of potential transforming lesions by photoreactivation suggests that pyrimidine dimers, as well as other lesions, are important in UV transformation of human cells. Human cells can also be transformed by transfection with cloned oncogenes, or with DNAs from tumors or tumor cell lines. Cells treated by the transfection procedure (but without DNA) or cells transfected with DNAs from normal mammalian cells or tissues show only background levels of transformation. Human cells can be transformed to anchorage-independent growth by DNAs ineffective in transformation of NIH 3T3 cells (including most human skin cancers), permitting the analysis of oncogenic molecular changes even in tumor DNAs difficult or impossible to analyze in rodent cell systems. 29 refs.; 4 figs.; 1 table

  4. Thermoregulatory Responses of Febrile Monkeys During Microwave Exposure

    National Research Council Canada - National Science Library

    Adair, E

    1997-01-01

    .... In a controlled ambient temperature of 26 degrees C, autonomic mechanisms of heat production and heat loss were measured in febrile squirrel monkeys during 30-min exposures to 450 or 2450 MHz CW MW...

  5. Enclosure design for flock-level, chronic exposure of birds to air contaminant mixtures.

    Science.gov (United States)

    North, Michelle A; Kinniburgh, David W; Smits, Judit E G

    2018-05-01

    The objective of this study was to design an enclosure suitable for studying the ecotoxicological effects of vehicle emissions on groups of wild birds without compromising welfare. Two, adjacent enclosures sheltered from sunlight, wind and rain, were bird-proofed and wrapped with thick polyethylene sheeting. Emissions were directed into the treatment enclosure from the exhaust of a light-duty gasoline truck, using flexible, heat-proof pipe, with joins sealed to prevent leakage. During active exposure, the engine was idled for 5 h/day, 6 days/week for 4 weeks. Fans maintained positive pressure (controls) and negative pressure (treatment), preventing cross-contamination of enclosures and protecting investigators. Four sets of passive, badge-type samplers were distributed across each enclosure, measuring nitrogen dioxide, sulfur dioxide and volatile organic compounds (NO 2 , SO 2 and VOCs, respectively), and were complemented by active monitors measuring VOCs and particulate matter (2.5 µm diameter, PM 2.5 ). We found that the concentrations of NO 2 , SO 2 and PM 2.5 were not different between treatment and control enclosures. Volatile organic compounds (e.g. benzene, toluene, ethylbenzene and xylenes) were approximately six times higher in the treatment enclosure than control (13.23 and 2.13 µg m -1 , respectively). In conclusion, this represents a successful, practical design for studying the effects of sub-chronic to chronic exposure to realistic mixtures of vehicle exhaust contaminants, in groups of birds. Recommended modifications for future research include a chassis dynamometer (vehicle treadmill), to better replicate driving conditions including acceleration and deceleration.

  6. Sea Ice, Clouds, Sunlight, and Albedo: The Umbrella Versus the Blanket

    Science.gov (United States)

    Perovich, D. K.

    2017-12-01

    The Arctic sea ice cover has undergone a major decline in recent years, with reductions in ice extent, ice thickness, and ice age. Understanding the feedbacks and forcing driving these changes is critical in improving predictions. The surface radiation budget plays a central role in summer ice melt and is governed by clouds and surface albedo. Clouds act as an umbrella reducing the downwelling shortwave, but also serve as a blanket increasing the downwelling longwave, with the surface albedo also determining the net balance. Using field observations from the SHEBA program, pairs of clear and cloudy days were selected for each month from May through September and the net radiation flux was calculated for different surface conditions and albedos. To explore the impact of albedo we calculated a break even albedo, where the net radiation for cloudy skies is the same as clear skies. For albedos larger than the break-even value the net radiation flux is smaller under clear skies compared to cloudy skies. Break-even albedos ranged from 0.30 in September to 0.58 in July. For snow covered or bare ice, clear skies always resulted in less radiative heat input. In contrast, leads always had, and ponds usually had, more radiative heat input under clear skies than cloudy skies. Snow covered ice had a net radiation flux that was negative or near zero under clear skies resulting in radiative cooling. We combined the albedo of individual ice types with the area of those ice types to calculate albedos averaged over a 50 km x 50 km area. The July case had the smallest areally averaged albedo of 0.50. This was less than the breakeven albedo, so cloudy skies had a smaller net radiation flux than clear skies. For the cases from the other four months, the areally averaged albedo was greater than the break-even albedo. The areally averaged net radiation flux was negative under clear skies for the May and September cases.

  7. District heating

    International Nuclear Information System (INIS)

    Hansen, L.

    1993-01-01

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

  8. Solar thermoelectricity via advanced latent heat storage

    Science.gov (United States)

    Olsen, M. L.; Rea, J.; Glatzmaier, G. C.; Hardin, C.; Oshman, C.; Vaughn, J.; Roark, T.; Raade, J. W.; Bradshaw, R. W.; Sharp, J.; Avery, A. D.; Bobela, D.; Bonner, R.; Weigand, R.; Campo, D.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

    2016-05-01

    We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a "thermal valve," which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.

  9. Photocatalysis and self-cleaning from g-C3N4 coated cotton fabrics under sunlight irradiation

    Science.gov (United States)

    Fan, Yunde; Zhou, Ji; Zhang, Jin; Lou, Yaqin; Huang, Zhenwu; Ye, Yong; Jia, Li; Tang, Bin

    2018-05-01

    Graphite-like carbon nitride (g-C3N4) nanosheets have been facilely assembled via electrostatic interaction onto cotton fabrics for achieving multi-functionalities. The surface morphologies, chemical composition and optical features of the g-C3N4-coated fabrics were characterized. The treated cotton fabrics exhibited remarkable photocatalytic degradation activity and superior self-cleaning performance. A complete degradation of Rhodamine B (RhB) and removal of stains were accomplished under simulated sunlight irradiation. More importantly, the modified fabrics can be reused in catalysis reactions with great durability. The practical treatment approach demonstrated from this work has great potential to be applied in textile industry for functional fabrics manufacture.

  10. Reconfigurable Charge Pump Circuit with Variable Pumping Frequency Scheme for Harvesting Solar Energy under Various Sunlight Intensities

    Directory of Open Access Journals (Sweden)

    Jeong Heon Kim

    2014-01-01

    Full Text Available We propose variable pumping frequency (VPF scheme which is merged with the previous reconfigurable charge pump (RCP circuit that can change its architecture according to a given sunlight condition. Here, merging the VPF scheme with the architecture reconfiguration can improve percentage output currents better by 21.4% and 22.4% than RCP circuit with the fixed pumping frequencies of 7 MHz and 15 MHz, respectively. Comparing the VPF scheme with real maximum power points (MPP, the VPF can deliver 91.9% of the maximum amount of output current to the load on average. In terms of the power and area overheads, the VPF scheme proposed in this paper consumes the power by 0.4% of the total power consumption and occupies the layout area by 1.61% of the total layout area.

  11. A Kolmogorov-type competition model with multiple coexistence states and its applications to plant competition for sunlight

    Science.gov (United States)

    Just, Winfried; Nevai, Andrew L.

    2008-12-01

    It is demonstrated that a Kolmogorov-type competition model featuring species allocation and gain functions can possess multiple coexistence statesE Two examples are constructed: one in which the two competing species possess rectangular allocation functions but distinct gain functions, and the other in which one species has a rectangular allocation function, the second species has a bi-rectangular allocation function, and the two species share a common gain function. In both examples, it is shown that the species nullclines may intersect multiple times within the interior of the first quadrant, thus creating both locally stable and unstable equilibrium points. These results have important applications in the study of plant competition for sunlight, in which the allocation functions describe the vertical placement of leaves for two competing species, and the gain functions represent rates of photosynthesis performed by leaves at different heights when shaded by overlying leaves belonging to either species.

  12. Abnormal responses to mid-ultraviolet light of cultured fibroblasts from patients with disorders featuring sunlight sensitivity

    International Nuclear Information System (INIS)

    Smith, P.J.; Paterson, M.C.

    1982-01-01

    The postultraviolet light (UV) colony-forming ability and DNA repair properties were examined of human skin fibroblasts derived from two groups of donors at high risk of cancer; (a) persons exhibiting sensitivity to sunlight; and (b) persons with conditions possibly associated with an underlying defect in the repair of radiogenic DNA damage. A comparison was made between the effects of far UV (254 nm) and mid UV (313 nm). Biochemical studies performed on strains sensitive to 313-nm UV alone suggest that their unusual photoresponse is not attributable to defective repair of cyclobutyl pyrimidine dimers. Furthermore, our data imply that thymine glycols are unlikely candidates for the critical lethal lesions in 313-nm UV-sensitive strains. Evidence is presented in support of the contention that mid UV may be partially radiomimetic, thus extending our understanding of the deleterious biological effects of this ubiquitous environmental carcinogen

  13. Sunlight to hydrogen conversion: Design optimization and energy management of concentrated photovoltaic (CPV-Hydrogen) system using micro genetic algorithm

    KAUST Repository

    Burhan, Muhammad

    2016-02-14

    Owing to the intermittent solar irradiance from cloud cover in the diurnal period and unavailability at night time, the practical design of a solar system requires energy backup storage for an uninterrupted supply or for off-grid operation. However, for highly efficient CPV (concentrated photovoltaic) system, the literature is lacking for energy management and optimization algorithm and tool for standalone operation. In this paper, a system with CPV and electrolyser is presented where beam irradiance of sunlight is harnessed to convert the instantaneously generated electricity into useful Hydrogen/Oxygen gas, where they can be stored and re-used for downstream applications such as the fuel cells, etc. The multi-variable design and multi-objective optimization strategies are proposed and presented for a standalone operation of the CPV-Hydrogen system as well as their system performances, particularly electrical rating of CPV based upon the real weather data of Singapore. © 2016 Elsevier Ltd.

  14. Roles of Saccharomyces cerevisiae DNA polymerases Polη and Polζ in response to irradiation by simulated sunlight

    Science.gov (United States)

    Kozmin, Stanislav G.; Pavlov, Youri I.; Kunkel, Thomas A.; Sage, Evelyne

    2003-01-01

    Sunlight causes lesions in DNA that if unrepaired and inaccurately replicated by DNA polymerases yield mutations that result in skin cancer in humans. Two enzymes involved in translesion synthesis (TLS) of UV-induced photolesions are DNA polymerase η (Polη) and polymerase ζ (Polζ), encoded by the RAD30A and REV3 genes, respectively. Previous studies have investigated the TLS roles of these polymerases in human and yeast cells irradiated with monochromatic, short wavelength UVC radiation (254 nm). However, less is known about cellular responses to solar radiation, which is of higher and mixed wavelengths (310–1100 nm) and produces a different spectrum of DNA lesions, including Dewar photoproducts and oxidative lesions. Here we report on the comparative cytotoxic and mutagenic effects of simulated sunlight (SSL) and UVC radiation on yeast wild-type, rad30Δ, rev3Δ and rev3Δ rad30Δ strains. The results with SSL support several previous interpretations on the roles of these two polymerases in TLS of photodimers and (6–4) photoproducts derived from studies with UVC. They further suggest that Polη participates in the non-mutagenic bypass of SSL-dependent cytosine-containing Dewar photoproducts and 8-oxoguanine, while Polζ is mainly responsible for the mutagenic bypass of all types of Dewar photoproducts. They also suggest that in the absence of Polζ, Polη contributes to UVC- and SSL-induced mutagenesis, possibly by the bypass of photodimers containing deaminated cytosine. PMID:12888515

  15. The effect of season and latitude on in vitro vitamin D formation by sunlight in South Africa.

    Science.gov (United States)

    Pettifor, J M; Moodley, G P; Hough, F S; Koch, H; Chen, T; Lu, Z; Holick, M F

    1996-10-01

    To assess the effect of season and latitude on the in vitro formation of previtamin D3 and vitamin D3 from 7-dehydrocholesterol (7-DHC) by sunlight in two cities in South Africa, Cape Town and Johannesburg. An in vitro study utilising vials containing 7-DHC, which were exposed to sunlight for a period of 1 hour between 8:00 and 17:00 on 1 day a month for a year. Previtamin D3 and vitamin D3 were separated from 7-DHC by high-performance liquid chromatography, and the amounts formed were calculated with the use of external standards. A marked seasonal variation in vitamin D3 production was noted in Cape Town, with very little being formed during the winter months of April through September. In Johannesburg, in vitro formation changed little throughout the year, and was similar to that found in Cape Town during the summer. During sunlit hours, vitamin D3 production was maximal at midday and small quantities were still being formed between 8:00 and 9:00, and between 16:00 and 17:00 during the summer. During winter in Cape Town, peak formation at midday was less than one-third of that in Johannesburg, and negligible amounts were formed before 10:00 and after 15:00. The previously documented seasonal variation in serum 25-hydroxyvitamin D recorded in patients in Johannesburg is probably a consequence of the increased clothing worn and the decreased time spent out of doors during winter, rather than decreased ultraviolet radiation reaching the earth. The limited in vitro formation of vitamin D3 during winter in Cape Town may have clinical implications insofar as the management of metabolic bone diseases like rickets and osteoporosis is concerned. Breast-fed infants resident in the area are likely to suffer from vitamin D deficiency rickets unless vitamin D supplements are provided, or the mothers are encouraged to take their children out of doors.

  16. [Vitamin D forming effectiveness of ultraviolet radiation from sunlight in different months in Budapest, Hungary].

    Science.gov (United States)

    Bakos, József; Mikó, Péter

    2007-02-18

    The vitamin D3 formation in skin is the most important natural source of vitamin D demands of humans. The key step of the phototransformation of provitamin D into previtamin D from which the vitamin D3 is formed by thermal conversion. According to studies run at the latitudes of Hungary the UV-B radiation in winter time is not satisfactory to ensure the need of the vitamin D, which can result in vitamin D 3 deficiency and increases risk of osteoporosis. The aim of this study was to verify whether in the Hungarian population the UV radiation from the Sun ensures the daily synthesis of 1000 IU vitamin D3, or Vitamin D deficiency could occur in the winter and spring months which are less favourable in terms of UV exposure. The data of UV-B radiation reaching the Earth's surface were used for the evaluation. These data based on regular measurements in Budapest. According to the average of UV-B radiation of each months the "best case scenario" of vitamin D3 production was estimated by using the most optimal conditions of vitamin D synthesis. It was calculated, that the effective UV irradiance reaching the Earth's surface at noon in Budapest is the highest in July, while the lowest is in December. The difference between these two months is more than 35-fold for July. In the period between November and March more than 200 minutes have to be spent outdoor to ensure the production of satisfactory amount of vitamin D in skin. On one hand, it is irrealistically long time because it exceeds the duration of maximum irradiation around noon which was the basis of our calculation. On the other hand, if only the face and hands are uncovered then the required radiant exposure exceeds the 1 minimal erythemal dose, i.e. the skin would be burnt. Based on our calculations it was found, that in Budapest more than 95% of yearly effective UV-B radiation is measurable in the period between March and October. Therefore it can be assumed that the UV-B radiation would not be sufficient in the

  17. Review: heat pipe heat exchangers at IROST

    OpenAIRE

    E. Azad

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

  19. Unwanted heat

    International Nuclear Information System (INIS)

    Benka, M.

    2006-01-01

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

  20. Heat Pipes

    Science.gov (United States)

    1990-01-01

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

  1. Solar thermochemical production of ammonia from water, air and sunlight: Thermodynamic and economic analyses

    International Nuclear Information System (INIS)

    Michalsky, Ronald; Parman, Bryon J.; Amanor-Boadu, Vincent; Pfromm, Peter H.

    2012-01-01

    Ammonia is an important input into agriculture and is used widely as base chemical for the chemical industry. It has recently been proposed as a sustainable transportation fuel and convenient one-way hydrogen carrier. Employing typical meteorological data for Palmdale, CA, solar energy is considered here as an inexpensive and renewable energy alternative in the synthesis of NH 3 at ambient pressure and without natural gas. Thermodynamic process analysis shows that a molybdenum-based solar thermochemical NH 3 production cycle, conducted at or below 1500 K, combined with solar thermochemical H 2 production from water may operate at a net-efficiency ranging from 23 to 30% (lower heating value of NH 3 relative to the total energy input). Net present value optimization indicates ecologically and economically sustainable NH 3 synthesis at above about 160 tons NH 3 per day, dependent primarily on heliostat costs (varied between 90 and 164 dollars/m 2 ), NH 3 yields (ranging from 13.9 mol% to stoichiometric conversion of fixed and reduced nitrogen to NH 3 ), and the NH 3 sales price. Economically feasible production at an optimum plant capacity near 900 tons NH 3 per day is shown at relative conservative technical assumptions and at a reasonable NH 3 sales price of about 534 ± 28 dollars per ton NH 3 . -- Highlights: ► Conceptual reactant and process improvements of solar-driven NH 3 synthesis at 1 bar. ► Thermodynamic underpinnings of a Molybdenum reactant. ► Process analysis determining energy and materials requirements and the net-efficiency. ► Net present value analysis accounting for yield, investment, and sales price variations.

  2. Monopole heat

    International Nuclear Information System (INIS)

    Turner, M.S.

    1983-01-01

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

  3. Heat exchanger

    International Nuclear Information System (INIS)

    Drury, C.R.

    1988-01-01

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

  4. Heat Convection

    Science.gov (United States)

    Jiji, Latif M.

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

  5. A review on opportunities for the development of heat pump drying systems in South Africa

    Directory of Open Access Journals (Sweden)

    Thomas Kivevele

    2014-05-01

    Full Text Available Recently, it has been discovered that heat pump drying is an efficient method of drying for drying industries. Heat pumps deliver more heat during the drying process than the work input to the compressor. Heat pump drying is a more advanced method than the traditional South African industrial and agricultural drying methods, such as direct/indirect sunlight, wood burning, fossil fuel burning, electrical heating and diesel engine heating. Heat pump dryers provide high energy efficiency with controllable temperature, air flow and air humidity and have significant energy-saving potential. In the last decade the market for heat pump systems for water heating and space cooling/heating has grown in South Africa, but the development of heat pumps for industrial and agricultural drying is very slow. As a result of high increases in fossil fuel prices and electricity in South Africa, as well as the problem of CO2 emissions, green energy, energy saving and energy efficiency are imperative. The development of heat pump drying systems in South Africa is an efficient way to solve energy problems in drying applications as this technology is still in its infancy. We review studies on heat pump drying and compare the methods therein with the most common methods of drying in South Africa.

  6. Preparation of K-doped TiO{sub 2} nanostructures by wet corrosion and their sunlight-driven photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Eunhye; Jin, Saera; Kim, Jiyoon; Chang, Sung-Jin [Department of Chemistry, Chung-Ang University, Seoul 06974 (Korea, Republic of); Jun, Byung-Hyuk [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Park, Kwang-Won, E-mail: bryan.kwangwon.park@gmail.com [Department of Chemistry, Chung-Ang University, Seoul 06974 (Korea, Republic of); Hong, Jongin, E-mail: hongj@cau.ac.kr [Department of Chemistry, Chung-Ang University, Seoul 06974 (Korea, Republic of)

    2016-08-30

    Highlights: • Potassium-doped TiO{sub 2} nanowire networks were prepared by the corrosion reaction of Ti nanoparticles in an alkaline solution. • They were applied to sunlight-driven photocatalytic degradation of differently charged dye molecules. • The adsorption of the dye molecules on the photocatalyst surface is crucial for their sunlight-driven photodegradation. - Abstract: K-doped TiO{sub 2} nanowire networks were prepared by the corrosion reaction of Ti nanoparticles in an alkaline (potassium hydroxide: KOH) solution. The prepared nanostructures were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffraction (XRD) and photoluminescence (PL) spectra. Their sunlight-driven photocatalytic activity was also investigated with differently charged dye molecules, such as methylene blue, rhodamine B and methyl orange. The adsorption of the dye molecules on the photocatalyst surface would play a critical role in their selective photodegradation under sunlight illumination.

  7. Meteorological Reference Years of Daily Mean Temperature during the Sunlight Time; Anos Tipos de Temperaturas Medias Diarias durante las Horas de Sol

    Energy Technology Data Exchange (ETDEWEB)

    Marchante Jimenez, M.; Ramirez Santigosa, L.N.; Mora Lopez, L.; Sidrach de Cardona Ortin, M.

    2002-07-01

    In this work the characterization of the daily mean temperature during the sunlight time has been analyzed. An algorithm for the hourly series generation from extreme daily values has been applied to evaluate the daily mean temperature during the sunlight time. A generic algorithm has been enounced as a function of the sunrise time. This algorithm allows taking into account the fractions related to the sunrise and sunset hours. This methodology has been applied in data from 45 Spanish stations, uniformly distributed in the Iberian Peninsula. Data for a period of 14 years has been used in most of locations, and once the interest variable has been calculated, the meteorological reference year of the daily mean temperature during the sunlight time has been evaluated in each stations. The next step is the evaluation of the daily mean temperature during the sunlight time in any point into the zone of evaluation, not only in the measured stations. >From the result data in each measured station, an geographic information system has been used in order to calculate the interpolation, obtaining maps with a data each 5 km for each of the 365 days of the year. Then, this results can be superposed with the solar radiation evaluation obtaining the input data for the sizing of the photovoltaic grid connected system in any point of the Spanish geography. (Author) 8 refs.

  8. Effect of cluster sun exposure on chemical composition and technological properties of grapes and wine from cultivars Cabernet sauvignon and mavrud

    International Nuclear Information System (INIS)

    Bambalov, V.; Rijchev, V.; Botyanski, P.

    2005-01-01

    A study was conducted on the effect of direct solar radiation on grape clusters of cvs Cabernet sauvignon and Mavrid, formed under four different microclimatic conditions: Vo- control; V1 - clusters exposed naturally to direct sunlight; V2 - clusters formed under natural shading; V3 - clusters formed under artificial shading.The positive impact of direct solar radiation on the formation of wine structure, character and body indicated the primary role of agrotechnical practices for ensuring better sunlight exposure of clusters and microclimatic conditions to enable the production of good wine-making materials

  9. 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.

  10. The Thermoregulatory Consequences of Heat Stroke: Are Cytokines Involved

    Science.gov (United States)

    2006-01-01

    71 6. Ambient temperature effects on heat stroke outcome ... exposure , the effectiveness of this treatment following administration directly into the hy- pothalamus was not tested (Lin et al., 1994). In addition, it is...versus that of heat exposure on experimental outcome (i.e., mortality). However, ethical concerns regarding the use of mortality as a study endpoint

  11. Heat exchanger

    Science.gov (United States)

    Wolowodiuk, Walter

    1976-01-06

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

  12. Heat exchangers

    International Nuclear Information System (INIS)

    1975-01-01

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

  13. Heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

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

    1975-04-30

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

  14. Heat exchanger

    International Nuclear Information System (INIS)

    Wolowodiuk, W.

    1976-01-01

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

  15. Can Aerosol Offset Urban Heat Island Effect?

    Science.gov (United States)

    Jin, M. S.; Shepherd, J. M.

    2009-12-01

    The Urban Heat Island effect (UHI) refers to urban skin or air temperature exceeding the temperatures in surrounding non-urban regions. In a warming climate, the UHI may intensify extreme heat waves and consequently cause significant health and energy problems. Aerosols reduce surface insolation via the direct effect, namely, scattering and absorbing sunlight in the atmosphere. Combining the National Aeronautics and Space Administration (NASA) AERONET (AErosol RObotic NETwork) observations over large cities together with Weather Research and Forecasting Model (WRF) simulations, we find that the aerosol direct reduction of surface insolation range from 40-100 Wm-2, depending on seasonality and aerosol loads. As a result, surface skin temperature can be reduced by 1-2C while 2-m surface air temperature by 0.5-1C. This study suggests that the aerosol direct effect is a competing mechanism for the urban heat island effect (UHI). More importantly, both aerosol and urban land cover effects must be adequately represented in meteorological and climate modeling systems in order to properly characterize urban surface energy budgets and UHI.

  16. Thyroid activity in heat adaptation

    International Nuclear Information System (INIS)

    Joshi, B.C.; Varshney, V.P.; Sanwal, P.C.

    1980-01-01

    The effect of acute and chronic (22 day round-the-clock) exposure to microenvironmental heat stress (37 deg C DBT) on thyroid activity was studied in Hariana x Holstein Frisian, Hariana x Brown Swiss and Hariana x Jersey non-cycling F 1 crossbred heifers. Vis-a-vis their no-heat norms, the percentage uptake of tri-iodothyronine- 125 I by resin registered a steep fall (about 45 to 60 percent) on acute heat exposures reaching a minimum value in about 2 hrs. The levels started recouping by the 2nd day, plateuing out on the 5th day onwards at slightly subnormal level with up and down fluctuations throughout the three week duration of exposure to heat. There were no significant differences in the pattern or magnitude of response amongst breeds, though in case of Holstein Frisian and Brown Swiss cross-breds the levels of T 3 tended, at times, to overshoot the no-stress norm. (author)

  17. Heat pipe heat exchangers in heat recovery systems

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-01-01

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

  18. Medical screening and evaluation for heat stress

    International Nuclear Information System (INIS)

    Kenney, L.W.

    1985-01-01

    Wide interindividual variation exists with respect to heat tolerance, making it difficult to predict individual responses. However, several general physical and physiological characteristics are associated with excessive strain and early exhaustion during work in the heat. Included among these correlates of heat intolerance are a medical history of heat illness, acclimation state, age, body composition and size, aerobic fitness level, hypertension, and drug and alcohol use. The approach of choice for medical evaluation for heat exposure is a two-stage evaluation. First, the examining physician should be encouraged to screen out those workers whose characteristics increase their risk of heat intolerance. Secondly, a short exercise test is proposed which accurately predicts relative heat tolerance across a working population. This test is recommended as an adjunct screening test at the examining physician's disgression

  19. Heat exchanger

    International Nuclear Information System (INIS)

    Bennett, J.C.

    1975-01-01

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

  20. Demonstration with Energy and Daylighting Assessment of Sunlight Responsive Thermochromic (SRT) Window Systems

    Energy Technology Data Exchange (ETDEWEB)

    Broekhuis, Michael; Liposcak, Curtis; Witte, Michael; Henninger, Robert; Zhou, Xiaohui; Petzen, George; Buchanan, Michael; Kumar, Sneh

    2012-03-31

    skylights during the months of May, June, July, August and 1.9 times higher than the thermochromic skylight during the months of March, April, September, October. Calculated illuminance levels were much more consistent as compared to the existing constant tint skylights installed at LinEl Signature. This allows for a more comfortable interior space in regard to glare discomfort and interior lighting control. Lawrence Berkeley National Laboratory was contracted to characterize the performance of the thermochromic interlayer and thermochromic window systems. Thermochromic interlayer was characterized with spectrometer equipment. The thermochromic window systems were characterized using LBNL’s Advanced Window Test Facility. A copy of the report can be found in the Appendix. Iowa State University was contracted to compare thermochromic window technology to constant tint technology. Iowa State University conducted the testing at the Energy Resource Station (ERS). The ERS has the ability to simultaneously test side-by-side competing building technologies. The building is equipped with two identical air handling units, each with its own dedicated and identical chiller. One air handling unit supplies the four test rooms designated as the A rooms and the other unit serves the four test rooms designated as the B rooms. There is one A test room and one B test rooms arranged as pairs in a side-by-side design with each pair having a different exposure. There is a pair of test rooms that face the south, an east and west facing pair. Each of the test rooms is a mirror image of its match with identical construction. The rooms are unoccupied; however, the capability to impose false loads on the rooms exists. The false loads and room lighting can be scheduled to simulate various usage patterns. A copy of the report can be found in the Appendix. GARD Analytics was contracted to compare EnergyPlus building simulations to the data recorded at the Iowa ERS. The goal of this research was to

  1. Study of fuel cell powerplant with heat recovery

    Science.gov (United States)

    King, J. M.; Grasso, A. P.; Clausi, J. V.

    1975-01-01

    It was shown that heat can be recovered from fuel cell power plants by replacing the air-cooled heat exchangers in present designs with units which transfer the heat to the integrated utility system. Energy availability for a 40-kW power plant was studied and showed that the total usable energy at rated power represents 84 percent of the fuel lower heating value. The effects of design variables on heat availability proved to be small. Design requirements were established for the heat recovery heat exchangers, including measurement of the characteristics of two candidate fuel cell coolants after exposure to fuel cell operating conditions. A heat exchanger test program was defined to assess fouling and other characteristics of fuel cell heat exchangers needed to confirm heat exchanger designs for heat recovery.

  2. Techno-economic evaluation of a ventilation system assisted with exhaust air heat recovery, electrical heater and solar energy

    OpenAIRE

    Özyoğurtçu, Gamze; Mobedi, Moghtada; Özerdem, Barış

    2014-01-01

    The energy consumed to condition fresh air is considerable, particularly for the buildings such as cinema, theatre or gymnasium saloons. The aim of the present study is to design a ventilation system assisted with exhaust air heat recovery unit, electrical heater and stored solar energy, then to make an economical analysis based on life cycle cost (LCC) to find out its payback period. The system is able to recover thermal energy of exhaust air, store solar energy during the sunlight period an...

  3. CONVERSION OF FOGWATER AND AEROSOL ORGANIC NITROGEN TO AMMONIUM, NITRATE, AND NOX DURING EXPOSURE TO SIMULATED SUNLIGHT AND OZONE. (R825433)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in resear