Inhibition of human copper trafficking by a small molecule significantly attenuates cancer cell proliferation

Science.gov (United States)

Wang, Jing; Luo, Cheng; Shan, Changliang; You, Qiancheng; Lu, Junyan; Elf, Shannon; Zhou, Yu; Wen, Yi; Vinkenborg, Jan L.; Fan, Jun; Kang, Heebum; Lin, Ruiting; Han, Dali; Xie, Yuxin; Karpus, Jason; Chen, Shijie; Ouyang, Shisheng; Luan, Chihao; Zhang, Naixia; Ding, Hong; Merkx, Maarten; Liu, Hong; Chen, Jing; Jiang, Hualiang; He, Chuan

2015-12-01

Copper is a transition metal that plays critical roles in many life processes. Controlling the cellular concentration and trafficking of copper offers a route to disrupt these processes. Here we report small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS, and so provide a selective approach to disrupt cellular copper transport. The knockdown of Atox1 and CCS or their inhibition leads to a significantly reduced proliferation of cancer cells, but not of normal cells, as well as to attenuated tumour growth in mouse models. We show that blocking copper trafficking induces cellular oxidative stress and reduces levels of cellular ATP. The reduced level of ATP results in activation of the AMP-activated protein kinase that leads to reduced lipogenesis. Both effects contribute to the inhibition of cancer cell proliferation. Our results establish copper chaperones as new targets for future developments in anticancer therapies.

Significant questions in thin liquid film heat transfer

International Nuclear Information System (INIS)

Bankoff, S.G.

1994-01-01

Thin liquid films appear in many contexts, such as the cooling of gas turbine blade tips, rocket engines, microelectronics arrays, and hot fuel element surfaces in hypothetical nuclear reactor accidents. Apart from these direct cooling applications of thin liquid layers, thin films form a crucial element in determining the allowable heat flux limits in boiling. This is because the last stages of dryout almost invariably involve the rupture of a residual liquid film, either as a microlayer underneath the bubbles, or a thin annular layer in a high-quality burnout scenario. The destabilization of these thin films under the combined actions of shear stress, evaporation, and thermocapillary effects is quite complex. The later stages of actual rupture to form dry regions, which then expand, resulting in possible overheating, are even more complex and less well understood. However, significant progress has been made in understanding the behavior of these thin films, which are subject to competing instabilities prior to actual rupture. This will be reviewed briefly. Recent work on the advance, or recession, of contact lines will also be described briefly, and significant questions that still remain to be answered will be discussed. 68 refs., 7 figs

Significance of bacterial flora in abdominal irradiation-induced inhibition of lung metastases

International Nuclear Information System (INIS)

Matsumoto, T.; Ando, K.; Koike, S.

1988-01-01

We have previously reported that abdominal irradiation prior to i.v. injection of syngeneic tumor cells reduced metastases in lung. Our report described an investigation of the significance of intestinal organisms in the radiation effect. We found that eliminating intestinal organisms with antibiotics totally abolished the radiation effect. Monoassociation of germ-free mice revealed that the radiation effect was observable only for Enterobacter cloacae, never for Streptococcus faecium, Bifidobacterium adlesentis, or Escherichia coli. After abdominal irradiation of regular mice, E. cloacae multiplied in cecal contents, adhered to mucous membranes, invaded the cecal wall, and translocated to mesenteric lymph nodes. Intravenous administration of E. cloacae in place of abdominal irradiation inhibited metastases. E. cloacae-monoassociated mice developed fewer metastases than germ-free mice, and the reduction was further enhanced by abdominal irradiation. We concluded that abdominal irradiation caused the invasion of E. cloacae from the mucous membrane of the intestine and inhibited formation of lung metastases

Significant enhancement of metal heat dissipation from mechanically exfoliated graphene nanosheets through thermal radiation effect

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Junxiong Hu

2017-05-01

Full Text Available We demonstrate a facile approach to significantly enhance the heat dissipation potential of conventional aluminum (Al heat sinks by mechanically coating graphene nanosheets. For Al and graphene-coated Al heat sinks, the change in temperature with change in coating coverage, coating thickness and heat flux are studied. It is found that with the increase in coating coverage from 0 to 100%, the steady-state temperature is decreased by 5 °C at a heat flux of 1.8 W cm-1. By increasing the average thickness of graphene coating from 480 nm to 1900 nm, a remarkable temperature reduction up to 7 °C can be observed. Moreover, with the increase in heat flux from 1.2 W cm-1 to 2.4 W cm-1, the temperature difference between uncoated and graphene-coated samples increases from 1 °C to 6 °C. The thermal analysis and finite element simulation reveal that the thermal radiation plays a key role in enhancing the heat dissipation performance. The effect of heat convection remains weak owing to the low air velocity at surface-air boundary. This work provides a technological innovation in improving metal heat dissipation using graphene nanosheets.

Insights into significance of combined inhibition of MEK and m-TOR signalling output in KRAS mutant non-small-cell lung cancer.

Science.gov (United States)

Broutin, Sophie; Stewart, Adam; Thavasu, Parames; Paci, Angelo; Bidart, Jean-Michel; Banerji, Udai

2016-08-23

We aimed to understand the dependence of MEK and m-TOR inhibition in EGFR(WT)/ALK(non-rearranged) NSCLC cell lines. In a panel of KRAS(M) and KRAS(WT) NSCLC cell lines, we determined growth inhibition (GI) following maximal reduction in p-ERK and p-S6RP caused by trametinib (MEK inhibitor) and AZD2014 (m-TOR inhibitor), respectively. GI caused by maximal m-TOR inhibition was significantly greater than GI caused by maximal MEK inhibition in the cell line panel (52% vs 18%, PTOR compared with maximal m-TOR+MEK inhibition. However, GI caused by the combination was significantly greater in the KRAS(M) cell lines (79% vs 61%, P=0.017). m-TOR inhibition was more critical to GI than MEK inhibition in EGFR(WT)/ALK(non-rearranged) NSCLC cells. The combination of MEK and m-TOR inhibition was most effective in KRAS(M) cells.

Coeliac disease autoantibodies mediate significant inhibition of tissue transglutaminase.

LENUS (Irish Health Repository)

Byrne, Greg

2012-02-01

The detection of antibodies directed against tissue transglutaminase (tTG) in serum is a sensitive and specific test for suspected coeliac disease. tTG is a ubiquitous, multifunctional enzyme that has been implicated in many important physiological processes as well as the site-specific deamidation of glutamine residues in gluten-derived peptides. This modification of gluten peptides facilitates their binding to HLA-DQ2, which results in amplification of the T-cell response to gluten. The purpose of this study was to investigate the possibility that patient IgA autoantibodies directed against tTG interfere with the crosslinking activity of the enzyme. IgA autoantibodies against tTG were isolated\\/depleted from patient serum and tested for their capacity to interfere with tTG activity in vitro using a sensitive fluorescence-based activity assay. We have demonstrated that autoantibodies cause significant inhibition of tTG-mediated crosslinking at equimolar and 2:1 ratios of antibody to enzyme.

Continuous delivery of propranolol from liposomes-in-microspheres significantly inhibits infantile hemangioma growth

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Guo XN

2017-09-01

Full Text Available Xiaonan Guo,1,* Xiaoshuang Zhu,1,* Dakan Liu,1 Yubin Gong,1 Jing Sun,2 Changxian Dong1 1Department of Hemangioma and Vascular Malformation, Henan Provincial People’s Hospital, Zhengzhou, People’s Republic of China; 2Department of Pharmacy, Second Military Medical University, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: To reduce the adverse effects and high frequency of administration of propranolol to treat infantile hemangioma, we first utilized propranolol-loaded liposomes-in-microsphere (PLIM as a novel topical release system to realize sustained release of propranolol.Methods: PLIM was developed from encapsulating propranolol-loaded liposomes (PLs in microspheres made of poly(lactic-co-glycolic acid-b-poly(ethylene glycol-b-poly(lactic-co-glycolic acid copolymers (PLGA-PEG-PLGA. The release profile of propranolol from PLIM was evaluated, and its biological activity was investigated in vitro using proliferation assays on hemangioma stem cells (HemSCs. Tumor inhibition was studied in nude mice bearing human subcutaneous infantile hemangioma.Results: The microspheres were of desired particle size (~77.8 µm and drug encapsulation efficiency (~23.9% and achieved sustained drug release for 40 days. PLIM exerted efficient inhibition of the proliferation of HemSCs and significantly reduced the expression of two angiogenesis factors (vascular endothelial growth factor-A [VEGF-A] and basic fibroblast growth factor [bFGF] in HemSCs. Notably, the therapeutic effect of PLIM in hemangioma was superior to that of propranolol and PL in vivo, as reflected by significantly reduced hemangioma volume, weight, and microvessel density. The mean hemangioma weight of the PLIM-treated group was significantly lower than that of other groups (saline =0.28 g, propranolol =0.21 g, PL =0.13 g, PLIM =0.03 g; PLIM vs saline: P<0.001, PLIM vs propranolol: P<0.001, PLIM vs PL: P<0.001. The mean microvessel density of

Extracts Obtained from Pterocarpus angolensis DC and Ziziphus mucronata Exhibit Antiplasmodial Activity and Inhibit Heat Shock Protein 70 (Hsp70 Function

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Tawanda Zininga

2017-07-01

Full Text Available Malaria parasites are increasingly becoming resistant to currently used antimalarial therapies, therefore there is an urgent need to expand the arsenal of alternative antimalarial drugs. In addition, it is also important to identify novel antimalarial drug targets. In the current study, extracts of two plants, Pterocarpus angolensis and Ziziphus mucronata were obtained and their antimalarial functions were investigated. Furthermore, we explored the capability of the extracts to inhibit Plasmodium falciparum heat shock protein 70 (Hsp70 function. Heat shock protein 70 (Hsp70 are molecular chaperones whose function is to facilitate protein folding. Plasmodium falciparum the main agent of malaria, expresses two cytosol-localized Hsp70s: PfHsp70-1 and PfHsp70-z. The PfHsp70-z has been reported to be essential for parasite survival, while inhibition of PfHsp70-1 function leads to parasite death. Hence both PfHsp70-1 and PfHsp70-z are potential antimalarial drug targets. Extracts of P. angolensis and Z. mucronata inhibited the basal ATPase and chaperone functions of the two parasite Hsp70s. Furthermore, fractions of P. angolensis and Z. mucronata inhibited P. falciparum 3D7 parasite growth in vitro. The extracts obtained in the current study exhibited antiplasmodial activity as they killed P. falciparum parasites maintained in vitro. In addition, the findings further suggest that some of the compounds in P. angolensis and Z. mucronata may target parasite Hsp70 function.

Heat Shock Protein 90 Inhibitor (17-AAG) Induces Apoptosis and Decreases Cell Migration/Motility of Keloid Fibroblasts.

Science.gov (United States)

Yun, In Sik; Lee, Mi Hee; Rah, Dong Kyun; Lew, Dae Hyun; Park, Jong-Chul; Lee, Won Jai

2015-07-01

The regulation of apoptosis, proliferation, and migration of fibroblasts is altered in keloids. The 90-kDa heat shock protein (heat shock protein 90) is known to play a key role in such regulation. Therefore, the authors investigated whether the inhibition of heat shock protein 90 in keloid fibroblasts could induce apoptosis and attenuate keloid fibroblast proliferation and migration. The authors evaluated heat shock protein 90 expression in keloid tissues with immunohistochemistry. The authors used cell viability [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays and annexin V/propidium iodide staining for apoptosis, a wound healing model and cell tracking system to assess cell migration, and Akt Western blotting analysis in keloid fibroblasts after inhibition of heat shock protein 90 with 17-allylaminodemethoxygeldanamycin (17-AAG). The expression of heat shock protein 90 in keloid tissues was significantly increased compared with normal tissues. The 17-AAG-treated keloid fibroblasts showed significantly decreased proliferation, promotion of apoptosis, and decreased expression of Akt. Furthermore, a dose-dependent decrease in cell migration was noted after 17-AAG treatment of keloid fibroblasts. The 17-AAG-treated keloid fibroblasts had less directionality to the wound center and migrated a shorter distance. The authors confirmed that the inhibition of heat shock protein 90 in keloid fibroblasts could promote apoptosis and attenuate proliferation and migration of keloid fibroblasts. Therefore, the authors think that the inhibition of heat shock protein 90 is a key factor in the regulation of biological processes in keloids. With further preclinical study, the authors will be able to apply these results clinically for keloid treatment.

Escherichia coli DinB inhibits replication fork progression without significantly inducing the SOS response.

Science.gov (United States)

Mori, Tetsuya; Nakamura, Tatsuro; Okazaki, Naoto; Furukohri, Asako; Maki, Hisaji; Akiyama, Masahiro Tatsumi

2012-01-01

The SOS response is readily triggered by replication fork stalling caused by DNA damage or a dysfunctional replicative apparatus in Escherichia coli cells. E. coli dinB encodes DinB DNA polymerase and its expression is upregulated during the SOS response. DinB catalyzes translesion DNA synthesis in place of a replicative DNA polymerase III that is stalled at a DNA lesion. We showed previously that DNA replication was suppressed without exogenous DNA damage in cells overproducing DinB. In this report, we confirm that this was due to a dose-dependent inhibition of ongoing replication forks by DinB. Interestingly, the DinB-overproducing cells did not significantly induce the SOS response even though DNA replication was perturbed. RecA protein is activated by forming a nucleoprotein filament with single-stranded DNA, which leads to the onset of the SOS response. In the DinB-overproducing cells, RecA was not activated to induce the SOS response. However, the SOS response was observed after heat-inducible activation in strain recA441 (encoding a temperature-sensitive RecA) and after replication blockage in strain dnaE486 (encoding a temperature-sensitive catalytic subunit of the replicative DNA polymerase III) at a non-permissive temperature when DinB was overproduced in these cells. Furthermore, since catalytically inactive DinB could avoid the SOS response to a DinB-promoted fork block, it is unlikely that overproduced DinB takes control of primer extension and thus limits single-stranded DNA. These observations suggest that DinB possesses a feature that suppresses DNA replication but does not abolish the cell's capacity to induce the SOS response. We conclude that DinB impedes replication fork progression in a way that does not activate RecA, in contrast to obstructive DNA lesions and dysfunctional replication machinery.

Significance of atmospheric effects of heat rejection from energy centers in the semi arid northwest

International Nuclear Information System (INIS)

Ramsdell, J.V.; Drake, R.L.; Young, J.R.

1976-01-01

The results presented in this paper have been obtained using simple atmospheric models in an attempt to optimize heat sink management in a conceptual nuclear energy center (NEC) at Hanford. The models have been designed to be conservatice in the sense that they are biased toward over prediction of the impact of cooling system effluents on humidity and fog. Thus the models are screening tools to be used to identify subjects for further, more realistic examination. Within this context the following conclusions have been reached: the evaluation of any atmospheric impact postulated for heat dissipation must be conducted in quantitative terms which can be used to determine the significance of the impact; of the potential atmospheric impacts of large heat releases from energy centers, the one most amenable to quantitative evaluation in meaningful terms as the increase in fog; a postulated increase in frequency of fog can be translated into terms of visibility and both can be evaluated statistically; the translation of a increase in fog to visibility terms permits economic evaluation of the impact; and the predicted impact of the HNEC on fog and visibility is statistically significant whether the energy center consists of 20 or 40 units

Indole and 3-indolylacetonitrile inhibit spore maturation in Paenibacillus alvei

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Cho Moo

2011-05-01

Full Text Available Abstract Background Bacteria use diverse signaling molecules to ensure the survival of the species in environmental niches. A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole that functions as an intercellular signal controlling diverse aspects of bacterial physiology. Results In this study, we sought a novel role of indole in a Gram-positive bacteria Paenibacillus alvei that can produce extracellular indole at a concentration of up to 300 μM in the stationary phase in Luria-Bertani medium. Unlike previous studies, our data show that the production of indole in P. alvei is strictly controlled by catabolite repression since the addition of glucose and glycerol completely turns off the indole production. The addition of exogenous indole markedly inhibits the heat resistance of P. alvei without affecting cell growth. Observation of cell morphology with electron microscopy shows that indole inhibits the development of spore coats and cortex in P. alvei. As a result of the immature spore formation of P. alvei, indole also decreases P. alvei survival when exposed to antibiotics, low pH, and ethanol. Additionally, indole derivatives also influence the heat resistance; for example, a plant auxin, 3-indolylacetonitrile dramatically (2900-fold decreased the heat resistance of P. alvei, while another auxin 3-indoleacetic acid had a less significant influence on the heat resistance of P. alvei. Conclusions Together, our results demonstrate that indole and plant auxin 3-indolylacetonitrile inhibit spore maturation of P. alvei and that 3-indolylacetonitrile presents an opportunity for the control of heat and antimicrobial resistant spores of Gram-positive bacteria.

Graphene oxide significantly inhibits cell growth at sublethal concentrations by causing extracellular iron deficiency.

Science.gov (United States)

Yu, Qilin; Zhang, Bing; Li, Jianrong; Du, Tingting; Yi, Xiao; Li, Mingchun; Chen, Wei; Alvarez, Pedro J J

Graphene oxide (GO)-based materials are increasingly being used in medical materials and consumer products. However, their sublethal effects on biological systems are poorly understood. Here, we report that GO (at 10 to 160 mg/L) induced significant inhibitory effects on the growth of different unicellular organisms, including eukaryotes (i.e. Saccharomyces cerevisiae, Candida albicans, and Komagataella pastoris) and prokaryotes (Pseudomonas fluorescens). Growth inhibition could not be explained by commonly reported cytotoxicity mechanisms such as plasma membrane damage or oxidative stress. Based on transcriptomic analysis and measurement of extra- and intracellular iron concentrations, we show that the inhibitory effect of GO was mainly attributable to iron deficiency caused by binding to the O-functional groups of GO, which sequestered iron and disrupted iron-related physiological and metabolic processes. This inhibitory mechanism was corroborated with supplementary experiments, where adding bathophenanthroline disulfonate-an iron chelating agent-to the culture medium exerted similar inhibition, whereas removing surface O-functional groups of GO decreased iron sequestration and significantly alleviated the inhibitory effect. These findings highlight a potential indirect detrimental effect of nanomaterials (i.e. scavenging of critical nutrients), and encourage research on potential biomedical applications of GO-based materials to sequester iron and enhance treatment of iron-dependent diseases such as cancer and some pathogenic infections.

They’re heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products

Science.gov (United States)

Caputi, Theodore L.; Leas, Eric; Dredze, Mark; Cohen, Joanna E.; Ayers, John W.

2017-01-01

Heat-not-burn tobacco products, battery powered devices that heat leaf tobacco to approximately 500 degrees Fahrenheit to produce an inhalable aerosol, are being introduced in markets around the world. Japan, where manufacturers have marketed several heat-not-burn brands since 2014, has been the focal national test market, with the intention of developing global marketing strategies. We used Google search query data to estimate, for the first time, the scale and growth potential of heat-not-burn tobacco products. Average monthly searches for heat-not-burn products rose 1,426% (95%CI: 746,3574) between their first (2015) and second (2016) complete years on the market and an additional 100% (95%CI: 60, 173) between the products second (2016) and third years on the market (Jan-Sep 2017). There are now between 5.9 and 7.5 million heat-not-burn related Google searches in Japan each month based on September 2017 estimates. Moreover, forecasts relying on the historical trends suggest heat-not-burn searches will increase an additional 32% (95%CI: -4 to 79) during 2018, compared to current estimates for 2017 (Jan-Sep), with continued growth thereafter expected. Contrasting heat-not-burn’s rise in Japan to electronic cigarettes’ rise in the United States we find searches for heat-not-burn eclipsed electronic cigarette searches during April 2016. Moreover, the change in average monthly queries for heat-not-burn in Japan between 2015 and 2017 was 399 (95% CI: 184, 1490) times larger than the change in average monthly queries for electronic cigarettes in the Unites States over the same time period, increasing by 2,956% (95% CI: 1729, 7304) compared to only 7% (95% CI: 3,13). Our findings are a clarion call for tobacco control leaders to ready themselves as heat-not-burn tobacco products will likely garner substantial interest as they are introduced into new markets. Public health practitioners should expand heat-not-burn tobacco product surveillance, adjust existing tobacco

They're heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products.

Directory of Open Access Journals (Sweden)

Theodore L Caputi

Full Text Available Heat-not-burn tobacco products, battery powered devices that heat leaf tobacco to approximately 500 degrees Fahrenheit to produce an inhalable aerosol, are being introduced in markets around the world. Japan, where manufacturers have marketed several heat-not-burn brands since 2014, has been the focal national test market, with the intention of developing global marketing strategies. We used Google search query data to estimate, for the first time, the scale and growth potential of heat-not-burn tobacco products. Average monthly searches for heat-not-burn products rose 1,426% (95%CI: 746,3574 between their first (2015 and second (2016 complete years on the market and an additional 100% (95%CI: 60, 173 between the products second (2016 and third years on the market (Jan-Sep 2017. There are now between 5.9 and 7.5 million heat-not-burn related Google searches in Japan each month based on September 2017 estimates. Moreover, forecasts relying on the historical trends suggest heat-not-burn searches will increase an additional 32% (95%CI: -4 to 79 during 2018, compared to current estimates for 2017 (Jan-Sep, with continued growth thereafter expected. Contrasting heat-not-burn's rise in Japan to electronic cigarettes' rise in the United States we find searches for heat-not-burn eclipsed electronic cigarette searches during April 2016. Moreover, the change in average monthly queries for heat-not-burn in Japan between 2015 and 2017 was 399 (95% CI: 184, 1490 times larger than the change in average monthly queries for electronic cigarettes in the Unites States over the same time period, increasing by 2,956% (95% CI: 1729, 7304 compared to only 7% (95% CI: 3,13. Our findings are a clarion call for tobacco control leaders to ready themselves as heat-not-burn tobacco products will likely garner substantial interest as they are introduced into new markets. Public health practitioners should expand heat-not-burn tobacco product surveillance, adjust existing

They're heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products.

Science.gov (United States)

Caputi, Theodore L; Leas, Eric; Dredze, Mark; Cohen, Joanna E; Ayers, John W

2017-01-01

Heat-not-burn tobacco products, battery powered devices that heat leaf tobacco to approximately 500 degrees Fahrenheit to produce an inhalable aerosol, are being introduced in markets around the world. Japan, where manufacturers have marketed several heat-not-burn brands since 2014, has been the focal national test market, with the intention of developing global marketing strategies. We used Google search query data to estimate, for the first time, the scale and growth potential of heat-not-burn tobacco products. Average monthly searches for heat-not-burn products rose 1,426% (95%CI: 746,3574) between their first (2015) and second (2016) complete years on the market and an additional 100% (95%CI: 60, 173) between the products second (2016) and third years on the market (Jan-Sep 2017). There are now between 5.9 and 7.5 million heat-not-burn related Google searches in Japan each month based on September 2017 estimates. Moreover, forecasts relying on the historical trends suggest heat-not-burn searches will increase an additional 32% (95%CI: -4 to 79) during 2018, compared to current estimates for 2017 (Jan-Sep), with continued growth thereafter expected. Contrasting heat-not-burn's rise in Japan to electronic cigarettes' rise in the United States we find searches for heat-not-burn eclipsed electronic cigarette searches during April 2016. Moreover, the change in average monthly queries for heat-not-burn in Japan between 2015 and 2017 was 399 (95% CI: 184, 1490) times larger than the change in average monthly queries for electronic cigarettes in the Unites States over the same time period, increasing by 2,956% (95% CI: 1729, 7304) compared to only 7% (95% CI: 3,13). Our findings are a clarion call for tobacco control leaders to ready themselves as heat-not-burn tobacco products will likely garner substantial interest as they are introduced into new markets. Public health practitioners should expand heat-not-burn tobacco product surveillance, adjust existing tobacco

Heat storage in the Andaman Sea

Digital Repository Service at National Institute of Oceanography (India)

RameshBabu, V.; Sastry, J.S.

Heat storage in the Andaman Sea in upper 20 m, where a strong halocline seems to inhibit vertical heat transport has been evaluated and discussed in relation to the other parameters of heat budget. Estimation of annual evaporation gives rise to 137...

Apoptosis in response to heat stress is positively associated with heat-shock protein 90 expression in chicken myocardial cells in vitro.

Science.gov (United States)

Zhang, Xiao-Hui; Wu, Hong; Tang, Shu; Li, Qiao-Ning; Xu, Jiao; Zhang, Miao; Su, Ya-Nan; Yin, Bin; Zhao, Qi-Ling; Kemper, Nicole; Hartung, Joerg; Bao, En-Dong

2017-06-30

To determine heat-shock protein (Hsp)90 expression is connected with cellular apoptotic response to heat stress and its mechanism, chicken ( Gallus gallus ) primary myocardial cells were treated with the Hsp90 promoter, aspirin, and its inhibitor, geldanamycin (GA), before heat stress. Cellular viability, heat-stressed apoptosis and reactive oxygen species level under different treatments were measured, and the expression of key proteins of the signaling pathway related to Hsp90 and their colocalization with Hsp90 were detected. The results showed that aspirin treatment increased the expression of protein kinase B (Akt), the signal transducer and activator of transcription (STAT)-3 and p-IKKα/β and the colocalization of Akt and STAT-3 with Hsp90 during heat stress, which was accompanied by improved viability and low apoptosis. GA significantly inhibited Akt expression and p-IKKα/β level, but not STAT-3 quantity, while the colocalization of Akt and STAT-3 with Hsp90 was weakened, followed by lower cell viability and higher apoptosis. Aspirin after GA treatment partially improved the stress response and apoptosis rate of tested cells caused by the recovery of Akt expression and colocalization, rather than the level of STAT-3 (including its co-localization with Hsp90) and p-IKKα/β. Therefore, Hsp90 expression has a positive effect on cellular capacity to resist heat-stressed injury and apoptosis. Moreover, inhibition of Hsp90 before stress partially attenuated its positive effects.

Inhibition of replicon initiation and DNA elongation in Chinese hamster ovary cells by treatment at 45.5 degrees C

International Nuclear Information System (INIS)

Wong, R.S.; Dewey, W.C.

1982-01-01

Heat treatment of Chinese hamster ovary cells at 45.5 degrees C for 15 minutes resulted in the inhibition of both the replicon initiation and the DNA elongation processes. Analysis of the DNA made after treatment showed that for up to 30 minutes after hyperthermia, there was a significant increase (45-80% above control level) in the amount of labeled DNA less than or equal to 40S in size and having a distinct peak of 20S. Therefore, elongation of 20S molecules into larger molecules was inhibited or slowed down. These small molecules did not accumulate when recovery times were longer than 30 minutes. The DNA made after 120 and 240 minutes postheat incubation was larger than control size and indicated that, although replicon initiation was still inhibited, elongation between replicons into 120S molecules could take place. However, their subsequent elongation into parental-size molecules was inhibited. The same delay in DNA elongation seen in cells examined immediately after treatment was still observed in cells heated and allowed to recover for 30 minutes. Also, after 30 minutes of recovery, heated cells still had more newly synthesized DNA in the single-stranded fraction than did control cells, which indicates that DNA elongation within a replicon is delayed for at least 30 minutes after heating. Furthermore, at 4 hours after heating, the inhibition of elongation of clusters of replicons into parental molecules prevailed

Corrosion protection of steel in ammonia/water heat pumps

Science.gov (United States)

Mansfeld, Florian B.; Sun, Zhaoli

2003-10-14

Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

Heat shock suppresses mating and sperm transfer in the rice leaf folder Cnaphalocrocis medinalis.

Science.gov (United States)

Liao, H J; Qian, Q; Liu, X D

2014-06-01

Temperature is a key environmental factor in determining the population size of Cnaphalocrocis medinalis in summer. High temperatures inhibit survival, development and fecundity of this insect. However, biological responses of female and male adults to heat shock, and physiological mechanism of high temperature suppressing population development are still ambiguous. We experimentally tested the impact of heat shock (5 h day-1) on biological traits, spermatogenesis and sperm transfer of adults of C. medinalis. The result showed that heat exposure to 39 and 40 °C for 5 h reduced longevity and copulation frequency of adults, and hatchability of eggs. Immediate survival rate of males was lower than that of females after 3 days of exposure to 41 °C. The oviposition period, copulation frequency, fecundity of adults and hatchability of eggs were significantly lower when male adults were exposed to 40 or 41 °C for 3 days. Heat shock decreased frequency and success rate of mating when males were exposed, and it also resulted in postponement of mating behaviour and prolongation of mating duration as both the female and male adults were exposed. Heat shock did not affect spermatogenesis, but significantly inhibited sperms maturation. Moreover, males could not ejaculate sperm into females during copulation when these male moths received heat shock. Heat shock remarkably suppressed mating behaviour and sperm transfer, which led to a dramatic decline of rice leaf folder populations.

The influence of ascorbic acid on the oxygen consumption and the heat production by the cells of wheat seedling roots with their mitochondrial electron transport chain inhibited at complexes I and III

International Nuclear Information System (INIS)

Gordon, L.K.; Rakhmatullina, D.F.; Ogorodnikova, T.I.; Alyabyev, A.J.; Minibayeva, F.V.; Loseva, N.L.; Mityashina, S.Y.

2007-01-01

The influence of exogenous ascorbic acid (AsA) on oxidative phosphorylation was studied using wheat seedling roots. Treatment of them with AsA stimulated the rates of oxygen consumption and the heat production and caused a decrease of the respiratory coefficient. The increase in respiration was prevented by inhibitors of ascorbate oxidase, diethyldithiocarbamate (DEDTC), and of cytochrome oxidase, cyanide (KCN). Exogenous AsA sharply stimulated the rate of oxygen consumption of roots when complexes I and III of the mitochondrial electron transport chain were inhibited by rotenone and antimycin A, respectively, while the rates of heat production did not change significantly. It is concluded that AsA is a potent energy substrate, which can be used in conditions of failing I and III complexes in the mitochondrial electron transport chain

Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes

Energy Technology Data Exchange (ETDEWEB)

He, Yonghan [Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, 157 Baojian Road, Harbin 150081 (China); Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223 (China); Li, Ying [Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, 157 Baojian Road, Harbin 150081 (China); Zhang, Shuocheng [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Perry, Ben [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Department of Biomedical Sciences, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, Canada C1A 4P3 (Canada); Zhao, Tiantian [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Department of Psychology, University of Toronto, 1265 Military Trail, Toronto, ON, Canada M1C 1A4 (Canada); Wang, Yanwen, E-mail: yanwen.wang@nrc.ca [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Department of Biomedical Sciences, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, Canada C1A 4P3 (Canada); Sun, Changhao, E-mail: sun2002changhao@yahoo.com [Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, 157 Baojian Road, Harbin 150081 (China)

2013-06-28

Highlights: •Radicicol suppressed intracellular fat accumulation in 3T3-L1 adipocytes. •Radicicol inhibited the expression of FAS and FABP4. •Radicicol blocked cell cycle at the G1-S phase during cell differentiation. •Radicicol inhibited the PDK1/Akt pathway in adipocyte differentiation. -- Abstract: Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPAR{sub γ}) and CCAAT element binding protein α (C/EBP{sub α}), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins.

Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes

International Nuclear Information System (INIS)

He, Yonghan; Li, Ying; Zhang, Shuocheng; Perry, Ben; Zhao, Tiantian; Wang, Yanwen; Sun, Changhao

2013-01-01

Highlights: •Radicicol suppressed intracellular fat accumulation in 3T3-L1 adipocytes. •Radicicol inhibited the expression of FAS and FABP4. •Radicicol blocked cell cycle at the G1-S phase during cell differentiation. •Radicicol inhibited the PDK1/Akt pathway in adipocyte differentiation. -- Abstract: Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPAR γ ) and CCAAT element binding protein α (C/EBP α ), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins

Transmitters and pathways mediating inhibition of spinal itch-signaling neurons by scratching and other counterstimuli.

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Tasuku Akiyama

Full Text Available Scratching relieves itch, but the underlying neural mechanisms are poorly understood. We presently investigated a role for the inhibitory neurotransmitters GABA and glycine in scratch-evoked inhibition of spinal itch-signaling neurons in a mouse model of chronic dry skin itch. Superficial dorsal horn neurons ipsilateral to hindpaw dry skin treatment exhibited a high level of spontaneous firing that was significantly attenuated by cutaneous scratching, pinch and noxious heat. Scratch-evoked inhibition was nearly abolished by spinal delivery of the glycine antagonist, strychnine, and was markedly attenuated by respective GABA(A and GABA(B antagonists bicuculline and saclofen. Scratch-evoked inhibition was also significantly attenuated (but not abolished by interruption of the upper cervical spinal cord, indicating the involvement of both segmental and suprasegmental circuits that engage glycine- and GABA-mediated inhibition of spinal itch-signaling neurons by noxious counterstimuli.

Protective effects of heat shock protein 70 on the acute lung injury of rats with heat stroke and its mechanism

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Yan GENG

2017-06-01

Full Text Available Objective To investigate the protective effect of heat shock protein (HSP 70 on the acute lung injury (ALI of rats with heat stroke. Methods Sixty four rats were randomly (by employing a random number table assigned into a sham-heated group (Sham group, heat stress group (HS group, and HS plus gluttamine treatment group (HS+GLN group and HS plus quercet in treatment group (HS+QU group, 16 each. All rats were housed in a artificial climate chamber, with the rats in the sham groups exposed to a temperature of 23℃ and humidity of 55%±5%, while the rats of HS, HS+GLN and HS+QU groups to an ambient temperature of 39℃ and humidity of 65%. During heat stress or sham heating, rectal temperature (Tr, systolic blood pressure (SBP and pulse rate (PR were monitored to observe the difference in heat stress response among the groups. The time point at which the SBP started to drop from the peak level was taken as the point of HS onset. At the onset of HS, heat exposure was terminated, then the rats were immediately removed from the chamber, and returned to room temperature. The rats were scarified 0h and 6h after HS onset respectively. After bronchoalveolar lavage fluid (BALF was collected, the lungs of all animals were harvested for pathological examination of lung injury. The concentrations of IL-1β, TNF-α and IL-6 in BALF and HSP70 in lung homogenate were measured by using an enzyme linked immunosorbent assay kit. Results Compared with HS and HS+QU groups, the rats in HS+GLN group required significantly greater heat load to induce HS (P<0.001, and had longer survival time span after HS onset. Compared with Sham group, the concentration of HSP70 in lung homogenate in HS group increased in a time-dependent manner (P<0.001. In comparison with HS group, the concentration of HSP70 in lung homogenate from HS+GLN group was significantly elevated at each time point (P<0.001, while the treatment with QU significantly inhibited the expression of HSP70 (P<0

Significant effect of Ca2+ on improving the heat resistance of lactic acid bacteria.

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Huang, Song; Chen, Xiao Dong

2013-07-01

The heat resistance of lactic acid bacteria (LAB) has been extensively investigated due to its highly practical significance. Reconstituted skim milk (RSM) has been found to be one of the most effective protectant wall materials for microencapsulating microorganisms during convective drying, such as spray drying. In addition to proteins and carbohydrate, RSM is rich in calcium. It is not clear which component is critical in the RSM protection mechanism. This study investigated the independent effect of calcium. Ca(2+) was added to lactose solution to examine its influence on the heat resistance of Lactobacillus rhamnosus ZY, Lactobacillus casei Zhang, Lactobacillus plantarum P8 and Streptococcus thermophilus ND03. The results showed that certain Ca(2+) concentrations enhanced the heat resistance of the LAB strains to different extents, that is produced higher survival and shorter regrowth lag times of the bacterial cells. In some cases, the improvements were dramatic. More scientifically insightful and more intensive instrumental study of the Ca(2+) behavior around and in the cells should be carried out in the near future. In the meantime, this work may lead to the development of more cost-effective wall materials with Ca(2+) added as a prime factor. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Pharmacological kynurenine 3-monooxygenase enzyme inhibition significantly reduces neuropathic pain in a rat model.

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Rojewska, Ewelina; Piotrowska, Anna; Makuch, Wioletta; Przewlocka, Barbara; Mika, Joanna

2016-03-01

Recent studies have highlighted the involvement of the kynurenine pathway in the pathology of neurodegenerative diseases, but the role of this system in neuropathic pain requires further extensive research. Therefore, the aim of our study was to examine the role of kynurenine 3-monooxygenase (Kmo), an enzyme that is important in this pathway, in a rat model of neuropathy after chronic constriction injury (CCI) to the sciatic nerve. For the first time, we demonstrated that the injury-induced increase in the Kmo mRNA levels in the spinal cord and the dorsal root ganglia (DRG) was reduced by chronic administration of the microglial inhibitor minocycline and that this effect paralleled a decrease in the intensity of neuropathy. Further, minocycline administration alleviated the lipopolysaccharide (LPS)-induced upregulation of Kmo mRNA expression in microglial cell cultures. Moreover, we demonstrated that not only indirect inhibition of Kmo using minocycline but also direct inhibition using Kmo inhibitors (Ro61-6048 and JM6) decreased neuropathic pain intensity on the third and the seventh days after CCI. Chronic Ro61-6048 administration diminished the protein levels of IBA-1, IL-6, IL-1beta and NOS2 in the spinal cord and/or the DRG. Both Kmo inhibitors potentiated the analgesic properties of morphine. In summary, our data suggest that in neuropathic pain model, inhibiting Kmo function significantly reduces pain symptoms and enhances the effectiveness of morphine. The results of our studies show that the kynurenine pathway is an important mediator of neuropathic pain pathology and indicate that Kmo represents a novel pharmacological target for the treatment of neuropathy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sensible heat has significantly affected the global hydrological cycle over the historical period.

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Myhre, G; Samset, B H; Hodnebrog, Ø; Andrews, T; Boucher, O; Faluvegi, G; Fläschner, D; Forster, P M; Kasoar, M; Kharin, V; Kirkevåg, A; Lamarque, J-F; Olivié, D; Richardson, T B; Shawki, D; Shindell, D; Shine, K P; Stjern, C W; Takemura, T; Voulgarakis, A

2018-05-15

Globally, latent heating associated with a change in precipitation is balanced by changes to atmospheric radiative cooling and sensible heat fluxes. Both components can be altered by climate forcing mechanisms and through climate feedbacks, but the impacts of climate forcing and feedbacks on sensible heat fluxes have received much less attention. Here we show, using a range of climate modelling results, that changes in sensible heat are the dominant contributor to the present global-mean precipitation change since preindustrial time, because the radiative impact of forcings and feedbacks approximately compensate. The model results show a dissimilar influence on sensible heat and precipitation from various drivers of climate change. Due to its strong atmospheric absorption, black carbon is found to influence the sensible heat very differently compared to other aerosols and greenhouse gases. Our results indicate that this is likely caused by differences in the impact on the lower tropospheric stability.

Cytochrome c oxidase inhibition by calcium at physiological ionic composition of the medium: Implications for physiological significance of the effect.

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Vygodina, Tatiana V; Mukhaleva, Elizaveta; Azarkina, Natalia V; Konstantinov, Alexander A

2017-12-01

Cytochrome c oxidase (CcO) from mammalian mitochondria binds Ca 2+ and Na + in a special cation binding site. Binding of Ca 2+ brings about partial inhibition of the enzyme while Na + competes with Ca 2+ for the binding site and protects the enzyme from the inhibition [Vygodina, T., Kirichenko, A. and Konstantinov, A.A. (2013). Direct Regulation of Cytochrome c oxidase by Calcium Ions. PLoS One 8(9): e74436]. In the original studies, the inhibition was found to depend significantly on the ionic composition of the buffer. Here we describe inhibition of CcO by Ca 2+ in media containing the main ionic components of cytoplasm (150mM KCl, 12mM NaCl and 1mM MgCl 2 ). Under these conditions, Ca 2+ inhibits CcO with effective K i of 20-26μM, that is an order of magnitude higher than determined earlier in the absence of Na + . At physiological value of ionic strength, the inhibition can be observed at any turnover number of CcO, rather than only at low TN (calcium matches closely the known value of "K m " for Ca 2+ -induced activation of the mitochondrial calcium uniporter. The inhibition of CcO by Ca 2+ is proposed to modulate mitochondrial Ca 2+ -uptake via the mitochondrial calcium uniporter, promote permeability transition pore opening and induce reduction of Mia40 in the mitochondrial intermembrane space. Copyright © 2017 Elsevier B.V. All rights reserved.

Carvacrol Induces Heat Shock Protein 60 and Inhibits Synthesis of Flagellin in Escherichia coli O157:H7▿

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Burt, Sara A.; van der Zee, Ruurd; Koets, Ad P.; de Graaff, Anko M.; van Knapen, Frans; Gaastra, Wim; Haagsman, Henk P.; Veldhuizen, Edwin J. A.

2007-01-01

The essential oils of oregano and thyme are active against a number of food-borne pathogens, such as Escherichia coli O157:H7. Carvacrol is one of the major antibacterial components of these oils, and p-cymene is thought to be its precursor in the plant. The effects of carvacrol and p-cymene on protein synthesis in E. coli O157:H7 ATCC 43895 cells were investigated. Bacteria were grown overnight in Mueller-Hinton broth with a sublethal concentration of carvacrol or p-cymene, and their protein compositions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and confirmed by Western blotting. The presence of 1 mM carvacrol during overnight incubation caused E. coli O157:H7 to produce significant amounts of heat shock protein 60 (HSP60) (GroEL) (P < 0.05) and inhibited the synthesis of flagellin highly significantly (P < 0.001), causing cells to be aflagellate and therefore nonmotile. The amounts of HSP70 (DnaK) were not significantly affected. p-Cymene at 1 mM or 10 mM did not induce HSP60 or HSP70 in significant amounts and did not have a significant effect on flagellar synthesis. Neither carvacrol (0.3, 0.5, 0.8, or 1 mM) nor p-cymene (0.3, 0.5, or 0.8 mM) treatment of cells in the mid-exponential growth phase induced significant amounts of HSP60 or HSP70 within 3 h, although numerical increases of HSP60 were observed. Motility decreased with increasing concentrations of both compounds, but existing flagella were not shed. This study is the first to demonstrate that essential oil components induce HSP60 in bacteria and that overnight incubation with carvacrol prevents the development of flagella in E. coli O157:H7. PMID:17526792

Photosynthetic responses to heat treatments at different temperatures and following recovery in grapevine (Vitis amurensis L.) leaves.

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Luo, Hai-Bo; Ma, Ling; Xi, Hui-Feng; Duan, Wei; Li, Shao-Hua; Loescher, Wayne; Wang, Jun-Fang; Wang, Li-Jun

2011-01-01

The electron transport chain, Rubisco and stomatal conductance are important in photosynthesis. Little is known about their combined responses to heat treatment at different temperatures and following recovery in grapevines (Vitis spp.) which are often grown in climates with high temperatures. The electron transport function of photosystem II, the activation state of Rubisco and the influence of stomatal behavior were investigated in grapevine leaves during heat treatments and following recovery. High temperature treatments included 35, 40 and 45°C, with 25°C as the control and recovery temperature. Heat treatment at 35°C did not significantly (P>0.05) inhibit net photosynthetic rate (P(n)). However, with treatments at 40 and 45°C, P(n) was decreased, accompanied by an increase in substomatal CO(2) concentration (C(i)), decreases in stomatal conductance (g(s)) and the activation state of Rubisco, and inhibition of the donor side and the reaction center of PSII. The acceptor side of PSII was inhibited at 45°C but not at 40°C. When grape leaves recovered following heat treatment, P(n), g(s) and the activation state of Rubisco also increased, and the donor side and the reaction center of PSII recovered. The increase in P(n) during the recovery period following the second 45°C stress was slower than that following the 40°C stress, and these increases corresponded to the donor side of PSII and the activation state of Rubisco. Heat treatment at 35°C did not significantly (P>0.05) influence photosynthesis. The decrease of P(n) in grape leaves exposed to more severe heat stress (40 or 45°C) was mainly attributed to three factors: the activation state of Rubisco, the donor side and the reaction center of PSII. However, the increase of P(n) in grape leaves following heat stress was also associated with a stomatal response. The acceptor side of PSII in grape leaves was responsive but less sensitive to heat stress.

Reduced Contractility and Motility of Prostatic Cancer-Associated Fibroblasts after Inhibition of Heat Shock Protein 90

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Alex Henke

2016-08-01

Full Text Available Background: Prostate cancer-associated fibroblasts (CAF can stimulate malignant progression and invasion of prostatic tumour cells via several mechanisms including those active in extracellular matrix; Methods: We isolated CAF from prostate cancer patients of Gleason Score 6–10 and confirmed their cancer-promoting activity using an in vivo tumour reconstitution assay comprised of CAF and BPH1 cells. We tested the effects of heat shock protein 90 (HSP90 inhibitors upon reconstituted tumour growth in vivo. Additionally, CAF contractility was measured in a 3D collagen contraction assay and migration was measured by scratch assay; Results: HSP90 inhibitors dipalmitoyl-radicicol and 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG reduced tumour size and proliferation in CAF/BPH1 reconstituted tumours in vivo. We observed that the most contractile CAF were derived from patients with lower Gleason Score and of younger age compared with the least contractile CAF. HSP90 inhibitors radicicol and 17-DMAG inhibited contractility and reduced the migration of CAF in scratch assays. Intracellular levels of HSP70 and HSP90 were upregulated upon treatment with HSP90 inhibitors. Inhibition of HSP90 also led to a specific increase in transforming growth factor beta 2 (TGFβ2 levels in CAF; Conclusions: We suggest that HSP90 inhibitors act not only upon tumour cells, but also on CAF in the tumour microenvironment.

Inhibition of Cronobacter sakazakii by heat labile bacteriocins produced by probiotic LAB isolated from healthy infants.

Science.gov (United States)

Awaisheh, Saddam S; Al-Nabulsi, Anas A; Osaili, Tareq M; Ibrahim, Salam; Holley, Richard

2013-09-01

Cronobacter sakazakii is an opportunistic pathogen that can cause bacteremia, meningitis, and necrotizing enterocolitis, most often in neonates with case-fatality rates that may reach 80%. The antimicrobial activity of lactic acid bacteria against a wide range of foodborne pathogens is well-established in different types of food products. The objective of the current study was to investigate the antibacterial activity of Lactobacillus acidophilus and L. casei isolated from feces of healthy infants against different strains of C. sakazakii in agar and a rehydrated infant milk formula (RIMF) model. The inhibition zones of C. sakazakii around L. acidophilus or L. casei ranged from 22 to 32 mm on eMan Rogosa Sharpe (MRS) agar under aerobic conditions, while a slight reduction in antibacterial activity was noted on modified MRS (0.2% glucose) under anaerobic conditions. It was observed that pH-neutralized cell-free supernatant (CFS) of L. acidophilus or L. casei was inhibitory against tested C. sakazakii strains. The inhibition zones of neutralized CFS were lower than the antibacterial activities of live cultures. The antibacterial activity of CFS was abolished when CFS from L. acidophilus or L. casei was heated at 60 or 80 °C for either 10 min or 2 h, or treated with trypsin or pepsin. This was considered strong evidence that the inhibition was due to the production of bacteriocins by L. casei and L. acidophilus. Both the CFS and active growing cells of L. casei and L. acidophilus were able to reduce the viability of C. sakazakii in the RIMF model. The results may extend the use of natural antimicrobials instead of conventional preservation methods to improve the safety of RIMF. © 2013 Institute of Food Technologists®

Heat waves and their significance for a temperate benthic community: A near-natural experimental approach.

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Pansch, Christian; Scotti, Marco; Barboza, Francisco R; Al-Janabi, Balsam; Brakel, Janina; Briski, Elizabeta; Bucholz, Björn; Franz, Markus; Ito, Maysa; Paiva, Filipa; Saha, Mahasweta; Sawall, Yvonne; Weinberger, Florian; Wahl, Martin

2018-04-23

Climate change will not only shift environmental means but will also increase the intensity of extreme events, exerting additional stress on ecosystems. While field observations on the ecological consequences of heat waves are emerging, experimental evidence is rare, and lacking at the community level. Using a novel "near-natural" outdoor mesocosms approach, this study tested whether marine summer heat waves have detrimental consequences for macrofauna of a temperate coastal community, and whether sequential heat waves provoke an increase or decrease of sensitivity to thermal stress. Three treatments were applied, defined and characterized through a statistical analysis of 15 years of temperature records from the experimental site: (1) no heat wave, (2) two heat waves in June and July followed by a summer heat wave in August and (3) the summer heat wave only. Overall, 50% of the species showed positive, negative or positive/negative responses in either abundance and/or biomass. We highlight four possible ways in which single species responded to either three subsequent heat waves or one summer heat wave: (1) absence of a response (tolerance, 50% of species), (2) negative accumulative effects by three subsequent heat waves (tellinid bivalve), (3) buffering by proceeding heat waves due to acclimation and/or shifts in phenology (spionid polychaete) and (4) an accumulative positive effect by subsequent heat waves (amphipod). The differential responses to single or sequential heat waves at the species level entailed shifts at the community level. Community-level differences between single and triple heat waves were more pronounced than those between regimes with vs. without heat waves. Detritivory was reduced by the single heat wave while suspension feeding was less common in the triple heat wave regime. Critical extreme events occur already today and will occur more frequently in a changing climate, thus, leading to detrimental impacts on coastal marine systems. �

5,7-Dimethoxycoumarin prevents chronic mild stress induced depression in rats through increase in the expression of heat shock protein-70 and inhibition of monoamine oxidase-A levels

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Wei Yang

2018-02-01

Full Text Available The current study was aimed to investigate the role of 5,7-dimethoxycoumarin in the prevention of chronic mild stress induced depression in rats. The chronic mild stress rat model was prepared using the known protocols. The results from open-field test showed that rats in the chronic mild stress group scored very low in terms of crossings and rearings than those of the normal rats. However, pre-treatment of the rats with 10 mg/kg doses of 5,7-dimethoxycoumarin prevented decline in the locomotor activity by chronic mild stress. The level of monoamine oxidase-A in the chronic mild stress rat hippocampus was markedly higher. Chronic mild stress induced increase in the monoamine oxidase-A level was inhibited by pre-treatment with 10 mg/kg doses of 5,7-dimethoxycoumarin in the rats. Chronic mild stress caused a marked increase in the level of caspase-3 mRNA and proteins in rat hippocampus tissues. The increased level of caspase-3 mRNA and protein level was inhibited by treatment of rats with 5,7-dimethoxycoumarin (10 mg/kg. 5,7-Dimethoxycoumarin administration into the rats caused a marked increase in the levels of heat shock protein-70 mRNA and protein. The levels of heat shock protein-70 were markedly lower both in normal and chronic mild stress groups of rats compared to the 5,7-dimethoxycoumarin treated groups. Thus 5,7-dimethoxycoumarin prevented the chronic mild stress induced depression in rats through an increase in the expression of heat shock protein-70 and inhibition of monoamine oxidase-A levels.

5,7-Dimethoxycoumarin prevents chronic mild stress induced depression in rats through increase in the expression of heat shock protein-70 and inhibition of monoamine oxidase-A levels.

Science.gov (United States)

Yang, Wei; Wang, Huanlin

2018-02-01

The current study was aimed to investigate the role of 5,7-dimethoxycoumarin in the prevention of chronic mild stress induced depression in rats. The chronic mild stress rat model was prepared using the known protocols. The results from open-field test showed that rats in the chronic mild stress group scored very low in terms of crossings and rearings than those of the normal rats. However, pre-treatment of the rats with 10 mg/kg doses of 5,7-dimethoxycoumarin prevented decline in the locomotor activity by chronic mild stress. The level of monoamine oxidase-A in the chronic mild stress rat hippocampus was markedly higher. Chronic mild stress induced increase in the monoamine oxidase-A level was inhibited by pre-treatment with 10 mg/kg doses of 5,7-dimethoxycoumarin in the rats. Chronic mild stress caused a marked increase in the level of caspase-3 mRNA and proteins in rat hippocampus tissues. The increased level of caspase-3 mRNA and protein level was inhibited by treatment of rats with 5,7-dimethoxycoumarin (10 mg/kg). 5,7-Dimethoxycoumarin administration into the rats caused a marked increase in the levels of heat shock protein-70 mRNA and protein. The levels of heat shock protein-70 were markedly lower both in normal and chronic mild stress groups of rats compared to the 5,7-dimethoxycoumarin treated groups. Thus 5,7-dimethoxycoumarin prevented the chronic mild stress induced depression in rats through an increase in the expression of heat shock protein-70 and inhibition of monoamine oxidase-A levels.

In vitro inhibition of angiogenesis by heat and low pH stable hydroalcoholic extract of Peganum harmala seeds via inhibition of cell proliferation and suppression of VEGF secretion

DEFF Research Database (Denmark)

Yavari, Niloofar; Emamian, Farnoosh; Yarani, Reza

2015-01-01

) is a native plant from the eastern Iranian region, which is used as a traditional folk medicine. Although some biological properties of this plant are determined, its effect on angiogenesis is still unclear. Objective: We investigated the anti-angiogenic effects of heat and low pH stable hydroalcoholic...... and angiogenesis with an ID50 of ∼85 μg/ml. VEGF secretion was (inhibited) decreased by the extracts at concentrations higher than 10 μg/ml. Discussion and conclusion: Herbal plant extracts still attract attention owing to their fewer side effects comparing to synthetic drug agents. Current study indicated...

Food crops face rising temperatures: An overview of responses, adaptive mechanisms, and approaches to improve heat tolerance

OpenAIRE

Neeru Kaushal; Kalpna Bhandari; Kadambot H.M. Siddique; Harsh Nayyar

2016-01-01

The rising temperatures are resulting in heat stress for various agricultural crops to limit their growth, metabolism, and leading to significant loss of yield potential worldwide. Heat stress adversely affects normal plant growth and development depending on the sensitivity of each crop species. Each crop species has its own range of temperature maxima and minima at different developmental stages beyond which all these processes get inhibited. The reproductive stage is on the whole more sens...

Are US utility standby rates inhibiting diffusion of customer-owned generating systems?

International Nuclear Information System (INIS)

Jackson, Jerry

2007-01-01

New, small-scale electric generation technologies permit utility customers to generate some of their own electric power and to utilize waste heat for space heating and other applications at the building site. This combined heat and power (CHP) characteristic can provide significant energy-cost savings. However, most current US utility regulations leave CHP standby rate specification largely to utility discretion resulting in claims by CHP advocates that excessive standby rates are significantly reducing CHP-related savings and inhibiting CHP diffusion. The impacts of standby rates on the adoption of CHP are difficult to determine; however, because of the characteristically slow nature of new technology diffusion. This study develops an agent-based microsimulation model of CHP technology choice using cellular automata to represent new technology information dispersion and knowledge acquisition. Applying the model as an n-factorial experiment quantifies the impacts of standby rates on CHP technologies under alternative diffusion paths. Analysis of a sample utility indicates that, regardless of the likely diffusion process, reducing standby rates to reflect the cost of serving a large number of small, spatially clustered CHP systems significantly increases the adoption of these technologies

Endogenous Ethylene Concentration Is Not a Major Determinant of Fruit Abscission in Heat-Stressed Cotton (Gossypium hirsutum L.

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Ullah Najeeb

2017-09-01

Full Text Available We investigated the role of ethylene in the response of cotton to high temperature using cotton genotypes with genetically interrupted ethylene metabolism. In the first experiment, Sicot 71BRF and 5B (a lintless variant with compromised ethylene metabolism were exposed to 45°C, either by instantaneous heat shock or by ramping temperatures by 3°C daily for 1 week. One day prior to the start of heat treatment, half the plants were sprayed with 0.8 mM of the ethylene synthesis inhibitor, aminoethoxyvinylglycine (AVG. In a subsequent experiment, Sicot 71BRF and a putatively heat-tolerant line, CIM 448, were exposed to 36 or 45°C for 1 week, and half the plants were sprayed with 20 μM of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid, (ACC. High temperature exposure of plants in both experiments was performed at the peak reproductive phase (65–68 days after sowing. Elevated temperature (heat shock or ramping to 45°C significantly reduced production and retention of fruits in all cotton lines used in this study. At the termination of heat treatment, cotton plants exposed to 45°C had at least 50% fewer fruits than plants under optimum temperature in all three genotypes, while plants at 36°C remained unaffected. Heat-stressed plants continued producing new squares (fruiting buds after termination of heat stress but these squares did not turn into cotton bolls due to pollen infertility. In vitro inhibition of pollen germination by high temperatures supported this observation. Leaf photosynthesis (Pn of heat-stressed plants (45°C measured at the end of heat treatments remained significantly inhibited, despite an increased leaf stomatal conductance (gs, suggesting that high temperature impairs Pn independently of stomatal behavior. Metabolic injury was supported by high relative cellular injury and low photosystem II yield of the heat-stressed plants, indicating that high temperature impaired photosynthetic electron transport. Both

Near-field radiative heat transfer between clusters of dielectric nanoparticles

International Nuclear Information System (INIS)

Dong, J.; Zhao, J.M.; Liu, L.H.

2017-01-01

In this work, we explore the near-field radiative heat transfer between two clusters of silicon carbide (SiC) nanoparticles using the many-body radiative heat transfer theory. The effects of fractal dimension of clusters, many-body interaction between nanoparticles and relative orientation of clusters on the thermal conductance are studied. Meanwhile, the applicability of the equivalent volume spheres (EVS) approximation for near-field radiative heat transfer between clusters is examined. It is observed that the thermal conductance is larger for clusters with larger fractal dimension, which is more significant in the near-field. The thermal conductance of EVS resembles that of the clusters, but EVS overestimates the conductance of clusters, especially in the near-field. Compared to the case of two nanoparticles, the conductance of nanoparticle clusters decays much slower with increasing distance in the near-field, but shares similar dependence on the distance in the far-field. The thermal conductance of SiC nanoparticle clusters is inhibited by the many-body interaction when surface phonon polariton is supported but enhanced at frequencies close to the resonance frequency. The total thermal conductance is decreased due to many-body interaction among particles in the cluster. The relative orientation between the clusters is also an important factor in the near-field, especially for clusters with lower fractal dimension. - Highlights: • Near-field radiative heat transfer between clusters of nanoparticles is studied. • The many-body radiative heat transfer theory is applied for rigorous analysis. • The accuracy of equivalent volume spheres approximation is examined. • Clusters with larger fractal dimension have larger radiative thermal conductance. • Many-body interaction inhibits the total radiative thermal conductance.

Pathophysiology of Heat-Related Illnesses

Science.gov (United States)

2012-01-01

Figure 10-4). deHydrATion And elecTrolyTe imBAlAnce Water requirements during heat exposure are primarily deter- mined by a person’s sweat losses. Water...the effect of cyclooxygenase inhibition, J Clin Invest 81:1162, 1988. 241. Opal SM, Fisher CJ Jr, Dhainaut JF, et al: Confirmatory interleukin-1...inhibition, J Clin Invest 81:1162, 1988. 241. Opal SM, Fisher CJ Jr, Dhainaut JF, et al: Confirmatory interleukin-1 receptor antagonist trial in severe

Addition of sodium caseinate to skim milk increases nonsedimentable casein and causes significant changes in rennet-induced gelation, heat stability, and ethanol stability.

Science.gov (United States)

Lin, Yingchen; Kelly, Alan L; O'Mahony, James A; Guinee, Timothy P

2017-02-01

The protein content of skim milk was increased from 3.3 to 4.1% (wt/wt) by the addition of a blend of skim milk powder and sodium caseinate (NaCas), in which the weight ratio of skim milk powder to NaCas was varied from 0.8:0.0 to 0.0:0.8. Addition of NaCas increased the levels of nonsedimentable casein (from ∼6 to 18% of total casein) and calcium (from ∼36 to 43% of total calcium) and reduced the turbidity of the fortified milk, to a degree depending on level of NaCas added. Rennet gelation was adversely affected by the addition of NaCas at 0.2% (wt/wt) and completely inhibited at NaCas ≥0.4% (wt/wt). Rennet-induced hydrolysis was not affected by added NaCas. The proportion of total casein that was nonsedimentable on centrifugation (3,000 × g, 1 h, 25°C) of the rennet-treated milk after incubation for 1 h at 31°C increased significantly on addition of NaCas at ≥0.4% (wt/wt). Heat stability in the pH range 6.7 to 7.2 and ethanol stability at pH 6.4 were enhanced by the addition of NaCas. It is suggested that the negative effect of NaCas on rennet gelation is due to the increase in nonsedimentable casein, which upon hydrolysis by chymosin forms into small nonsedimentable particles that physically come between, and impede the aggregation of, rennet-altered para-casein micelles, and thereby inhibit the development of a gel network. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Technological significances to reduce the material problems. Feasibility of heat flux reduction

International Nuclear Information System (INIS)

Yamazaki, Seiichiro; Shimada, Michiya.

1994-01-01

For a divertor plate in a fusion power reactor, a high temperature coolant must be used for heat removal to keep thermal efficiency high. It makes the temperature and thermal stress of wall materials higher than the design limits. Issues of the coolant itself, e.g. burnout of high temperature water, will also become a serious problem. Sputtering erosion of the surface material will be a great concern of its lifetime. Therefore, it is necessary to reduce the heat and particle loads to the divertor plate technologically. The feasibility of some technological methods of heat reduction, such as separatrix sweeping, is discussed. As one of the most promising ideas, the methods of radiative cooling of the divertor plasma are summarized based on the recent results of large tokamaks. The feasibility of remote radiative cooling and gas divertor is discussed. The ideas are considered in recent design studies of tokamak power reactors and experimental reactors. By way of example, conceptual designs of divertor plate for the steady state tokamak power reactor are described. (author)

Combination treatment with ionising radiation and gefitinib ('Iressa', ZD1839), an epidermal growth factor receptor (EGFR) inhibitor, significantly inhibits bladder cancer cell growth in vitro and in vivo

International Nuclear Information System (INIS)

Colquhoun, AJ; Mchugh, LA; Tulchinsky, E.; Kriajevska, M.; Mellon, JK

2007-01-01

External beam radiotherapy (EBRT) is the principal bladder-preserving monotherapy for muscle-invasive bladder cancer. Seventy percent of muscle-invasive bladder cancers express epidermal growth factor receptor (EGFR), which is associated with poor prognosis. Ionising radiation (IR) stimulates EGFR causing activation of cytoprotective signalling cascades and thus may be an underlying cause of radioresistance in bladder tumours. We assessed the ability of IR to activate EGFR in bladder cancer cells and the effect of the anti-EGFR therapy, gefitinib on potential radiation-induced activation. Subsequently we assessed the effect of IR on signalling pathways downstream of EGFR. Finally we assessed the activity of gefitinib as a monotherapy, and in combination with IR, using clonogenic assay in vitro, and a murine model in vivo. IR activated EGFR and gefitinib partially inhibited this activation. Radiation-induced activation of EGFR activated the MAPK and Akt pathways. Gefitinib partially inhibited activation of the MAPK pathway but not the Akt pathway. Treatment with combined gefitinib and IR significantly inhibited bladder cancer cell colony formation more than treatment with gefitinib alone (p=0.001-0.03). J82 xenograft tumours treated with combined gefitinib and IR showed significantly greater growth inhibition than tumours treated with IR alone (p=0.04). Combining gefitinib and IR results in significantly greater inhibition of invasive bladder cancer cell colony formation in vitro and significantly greater tumour growth inhibition in vivo. Given the high frequency of EGFR expression by bladder tumours and the low toxicity of gefitinib there is justification to translate this work into a clinical trial. (author)

Metformin combined with aspirin significantly inhibit pancreatic cancer cell growth in vitro and in vivo by suppressing anti-apoptotic proteins Mcl-1 and Bcl-2

Science.gov (United States)

Yue, Wen; Zheng, Xi; Lin, Yong; Yang, Chung S.; Xu, Qing; Carpizo, Darren; Huang, Huarong; DiPaola, Robert S.; Tan, Xiang-Lin

2015-01-01

Metformin and aspirin have been studied extensively as cancer preventive or therapeutic agents. However, the effects of their combination on pancreatic cancer cells have not been investigated. Herein, we evaluated the effects of metformin and aspirin, alone or in combination, on cell viability, migration, and apoptosis as well as the molecular changes in mTOR, STAT3 and apoptotic signaling pathways in PANC-1 and BxPC3 cells. Metformin and aspirin, at relatively low concentrations, demonstrated synergistically inhibitory effects on cell viability. Compared to the untreated control or individual drug, the combination of metformin and aspirin significantly inhibited cell migration and colony formation of both PANC-1 and BxPC-3 cells. Metformin combined with aspirin significantly inhibited the phosphorylation of mTOR and STAT3, and induced apoptosis as measured by caspase-3 and PARP cleavage. Remarkably, metformin combined with aspirin significantly downregulated the anti-apoptotic proteins Mcl-1 and Bcl-2, and upregulated the pro-apoptotic proteins Bim and Puma, as well as interrupted their interactions. The downregulation of Mcl-1 and Bcl-2 was independent of AMPK or STAT3 pathway but partially through mTOR signaling and proteasome degradation. In a PANC-1 xenograft mouse model, we demonstrated that the combination of metformin and aspirin significantly inhibited tumor growth and downregulated the protein expression of Mcl-1 and Bcl-2 in tumors. Taken together, the combination of metformin and aspirin significantly inhibited pancreatic cancer cell growth in vitro and in vivo by regulating the pro- and anti-apoptotic Bcl-2 family members, supporting the continued investigation of this two drug combination as chemopreventive or chemotherapeutic agents for pancreatic cancer. PMID:26056043

Industrial waste heat for district heating

International Nuclear Information System (INIS)

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

1982-01-01

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

Antioxidants Inhibit Formation of 3-Monochloropropane-1,2-diol Esters in Model Reactions.

Science.gov (United States)

Li, Chang; Jia, Hanbing; Shen, Mingyue; Wang, Yuting; Nie, Shaoping; Chen, Yi; Zhou, Yongqiang; Wang, Yuanxing; Xie, Mingyong

2015-11-11

The capacities of six antioxidants to inhibit the formation of 3-monochloropropane-1,2 diol (3-MCPD) esters were examined in this study. Inhibitory capacities of the antioxidants were investigated both in chemical models containing the precursors (tripalmitoyl glycerol, 1,2-dipalmitoyl-sn-glycerol, monopalmitoyl glycerol, and sodium chloride) of 3-MCPD esters and in oil models (rapeseed oil and sodium chloride). Six antioxidants, butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA), tert-butyl hydroquinone (TBHQ), propyl gallate (PG), L-ascorbyl palmitate (AP), and α-tocopherol (VE), were found to exhibit inhibiting capacities on 3-MCPD ester formation both in chemical models and in oil models. TBHQ provided the highest inhibitory capacity both in chemical models and in oil models; 44% of 3-MCPD ester formation was inhibited in the presence of TBHQ (66 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min, followed by PG and AP. BHT, BHA, and VE appeared to have weaker inhibitory abilities in both models. VE exhibited the lowest inhibition rate; 22% of 3-MCPD esters were inhibited in the presence of VE (172 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min. In addition, the inhibition rates of PG and VE decreased dramatically with an increase in temperature or heating time. The results suggested that some antioxidants, such as TBHQ, PG, and AP, could be the potential inhibitors of 3-MCPD esters in practice.

Heat shock protein (Hsp) 40 mutants inhibit Hsp70 in mammalian cells

NARCIS (Netherlands)

Michels, AA; Kanon, B; Bensaude, O; Kampinga, HH

1999-01-01

Heat shock protein (Hsp) 70 and Hsp40 expressed in mammalian cells had been previously shown to cooperate in accelerating the reactivation of heat-denatured firefly luciferase (Michels, A. A., Kanon, B., Konings, A. W. T., Ohtsuka, K,, Bensaude, O., and Kampinga, H. H. (1997) J. Biol. Chem. 272,

Endosomolytic Nano-Polyplex Platform Technology for Cytosolic Peptide Delivery To Inhibit Pathological Vasoconstriction.

Science.gov (United States)

Evans, Brian C; Hocking, Kyle M; Kilchrist, Kameron V; Wise, Eric S; Brophy, Colleen M; Duvall, Craig L

2015-06-23

A platform technology has been developed and tested for delivery of intracellular-acting peptides through electrostatically complexed nanoparticles, or nano-polyplexes, formulated from an anionic endosomolytic polymer and cationic therapeutic peptides. This delivery platform has been initially tested and optimized for delivery of two unique vasoactive peptides, a phosphomimetic of heat shock protein 20 and an inhibitor of MAPKAP kinase II, to prevent pathological vasoconstriction (i.e., vasospasm) in human vascular tissue. These peptides inhibit vasoconstriction and promote vasorelaxation by modulating actin dynamics in vascular smooth muscle cells. Formulating these peptides into nano-polyplexes significantly enhances peptide uptake and retention, facilitates cytosolic delivery through a pH-dependent endosomal escape mechanism, and enhances peptide bioactivity in vitro as measured by inhibition of F-actin stress fiber formation. In comparison to treatment with the free peptides, which were endowed with cell-penetrating sequences, the nano-polyplexes significantly increased vasorelaxation, inhibited vasoconstriction, and decreased F-actin formation in the human saphenous vein ex vivo. These results suggest that these formulations have significant potential for treatment of conditions such as cerebral vasospasm following subarachnoid hemorrhage. Furthermore, because many therapeutic peptides include cationic cell-penetrating segments, this simple and modular platform technology may have broad applicability as a cost-effective approach for enhancing the efficacy of cytosolically active peptides.

Heat-processed ginseng saponin ameliorates the adenine-induced renal failure in rats

OpenAIRE

Kim, Eun Jin; Oh, Hyun-A; Choi, Hyuck Jai; Park, Jeong Hill; Kim, Dong-Hyun; Kim, Nam Jae

2013-01-01

To evaluate the effect of the saponin of heat-processed ginseng (Sun ginseng, SG), we investigated the protective effect of SG total saponin fraction against adenine-induced chronic renal failure in rats. SG saponin significantly decreased the levels of urea nitrogen and creatinine in the serum, but increased the urinary excretion of urea nitrogen and creatinine, indicating an improvement of renal function. SG saponin also inhibited adenine-induced kidney hypertrophy and edema. SG saponin red...

Heat waves imposed during early pod development in soybean (Glycine max) cause significant yield loss despite a rapid recovery from oxidative stress.

Science.gov (United States)

Siebers, Matthew H; Yendrek, Craig R; Drag, David; Locke, Anna M; Rios Acosta, Lorena; Leakey, Andrew D B; Ainsworth, Elizabeth A; Bernacchi, Carl J; Ort, Donald R

2015-08-01

Heat waves already have a large impact on crops and are predicted to become more intense and more frequent in the future. In this study, heat waves were imposed on soybean using infrared heating technology in a fully open-air field experiment. Five separate heat waves were applied to field-grown soybean (Glycine max) in central Illinois, three in 2010 and two in 2011. Thirty years of historical weather data from Illinois were analyzed to determine the length and intensity of a regionally realistic heat wave resulting in experimental heat wave treatments during which day and night canopy temperatures were elevated 6 °C above ambient for 3 days. Heat waves were applied during early or late reproductive stages to determine whether and when heat waves had an impact on carbon metabolism and seed yield. By the third day of each heat wave, net photosynthesis (A), specific leaf weight (SLW), and leaf total nonstructural carbohydrate concentration (TNC) were decreased, while leaf oxidative stress was increased. However, A, SLW, TNC, and measures of oxidative stress were no different than the control ca. 12 h after the heat waves ended, indicating rapid physiological recovery from the high-temperature stress. That end of season seed yield was reduced (~10%) only when heat waves were applied during early pod developmental stages indicates the yield loss had more to do with direct impacts of the heat waves on reproductive process than on photosynthesis. Soybean was unable to mitigate yield loss after heat waves given during late reproductive stages. This study shows that short high-temperature stress events that reduce photosynthesis and increase oxidative stress resulted in significant losses to soybean production in the Midwest, U.S. The study also suggests that to mitigate heat wave-induced yield loss, soybean needs improved reproductive and photosynthetic tolerance to high but increasingly common temperatures. Published 2015. This article is a U.S. Government work and is

Growth inhibition and differences in protein profiles in azadirachtin-treated Drosophila melanogaster larvae.

Science.gov (United States)

Wang, Hao; Lai, Duo; Yuan, Mei; Xu, Hanhong

2014-04-01

Azadirachtin A is a very effective biopesticide widely used in insect pest control. It has strong antifeeding and growth inhibitory activity against most insects, however, its mode of action is still unclear. Proteomic experiments using 2DE indicate significant effects of Azadirachtin A on the amount of proteins related to growth inhibition in Drosophila melanogaster larvae. Twenty-one spots with different intensity in azadirachtin-treated larvae were identified. These proteins are involved in cytoskeletal organization, transcription and translation, hormonal regulation, and energy metabolism. Protein network analysis reveals heat shock protein 23 to be a potential target of azadirachtin. These results provide new insights into understanding the mechanism of growth inhibition in insects in response to azadirachtin. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fisetin, a dietary flavonoid, induces apoptosis of cancer cells by inhibiting HSF1 activity through blocking its binding to the hsp70 promoter.

Science.gov (United States)

Kim, Joo Ae; Lee, Somyoung; Kim, Da-Eun; Kim, Moonil; Kwon, Byoung-Mog; Han, Dong Cho

2015-06-01

Heat shock factor 1 (HSF1) is a transcription factor for heat shock proteins (HSPs) expression that enhances the survival of cancer cells exposed to various stresses. HSF1 knockout suppresses carcinogen-induced cancer induction in mice. Therefore, HSF1 is a promising therapeutic and chemopreventive target. We performed cell-based screening with a natural compound collection and identified fisetin, a dietary flavonoid, as a HSF1 inhibitor. Fisetin abolished heat shock-induced luciferase activity with an IC50 of 14 μM in HCT-116 cancer cells. The treatment of HCT-116 with fisetin inhibited proliferation with a GI50 of 23 μM. When the cells were exposed to heat shock in the presence of fisetin, the induction of HSF1 target proteins, such as HSP70, HSP27 and BAG3 (Bcl-2-associated athanogene domain 3), were inhibited. HSP70/BAG3 complexes protect cancer cells from apoptosis by stabilizing anti-apoptotic Bcl-2 family proteins. The downregulation of HSP70/BAG3 by fisetin significantly reduced the amounts of Bcl-2, Bcl-xL and Mcl-1 proteins, subsequently inducing apoptotic cell death. Chromatin immunoprecipitation assays showed that fisetin inhibited HSF1 activity by blocking the binding of HSF1 to the hsp70 promoter. Intraperitoneal treatment of nude mice with fisetin at 30mg/kg resulted in a 35.7% (P < 0.001) inhibition of tumor growth. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Heat Exchangers for Utilization of the Heat of High-Temperature Geothermal Brines

Science.gov (United States)

Alkhasov, A. B.; Alkhasova, D. A.

2018-03-01

The basic component of two-circuit geothermal systems is the heat exchanger. When used in geothermal power systems, conventional shell-and-tube and plate heat exchangers cause problems related to the cleaning of the latter from salt-deposition and corrosion products. Their lifetime does not exceed, as a rule, 1 year. To utilize the heat of high-temperature geothermal brines, a heat exchanger of the "tube-in-tube" type is proposed. A heat exchanger of this design has been operated for several years in Ternair geothermal steam field; in this heat exchanger, the thermal potential of the saline thermal water is transferred to the fresh water of the secondary circuit of the heating system for apartment houses. The reduction in the weight and size characteristics of the heat exchangers is a topical problem that can be solved with the help of heat transfer enhancers. To enhance the heat transfer process in the heat exchanger, longitudinal ribbing of the heat exchange surface is proposed. The increase in the heat exchange surface from the heat carrier side by ribbing results in an increase in the amount of the heat transferred from the heating agent. The heat exchanger is easy to manufacture and is assembled out of components comprised of two concentrically positioned tubes of a definite length, 3-6 m, serially connected with each other. The method for calculation of the impact of the number and the size of the longitudinal ribs on the heat transfer in the well heat exchanger is presented and a criterion for the selection of the optimal number and design parameters of the ribs is formulated. To prevent the corrosion and salt deposition in the heat exchanger, the use of an effective OEDFK (oxyethylidenediphosphonic acid) agent is proposed. This agent has a long-lasting corrosion-inhibiting and antiscaling effect, which is explained by the formation of a strongly adhesive chelate layer difficult to wash off the surface. The passivating OEDFK layer is restored by periodical

In vivo binding in rat brain and radiopharmaceutical preparation of radioiodinated HEAT, an alpha-1 adrenoceptor ligand

International Nuclear Information System (INIS)

Couch, M.W.; Greer, D.M.; Thonoor, C.M.; Williams, C.M.

1988-01-01

In vivo binding of [ 125 I]-2-[beta-(3-iodo-4-hydroxyphenyl)ethylaminomethyl tetralone) ([ 125 I]HEAT) to alpha-1 adrenoceptors in the rat brain was determined over 4 hr. Uptake in the thalamus and frontal cortex was approximately 0.1% injected dose per gram tissue. Thalamus/cerebellum ratios of 10:1 and frontal cortex/cerebellum ratios of 5:1 were found at 4 hr. Pretreatment with prazosin, an alpha-1 antagonist, completely inhibited the accumulation of [ 125 I]HEAT in thalamus and frontal cortex; yet uptake of radioactivity was not significantly affected by antagonists and agonists for other receptors classes (propranolol, beta-1; apomorphine, D-1; spiperone, D-2). Binding of [ 125 I]HEAT is saturable. At 4 hr, [ 125 I]HEAT or [ 123 I]HEAT was shown to be the only radioactive material in rat thalamus and frontal cortex. Iodine-123 HEAT and [ 125 I]HEAT were synthesized as radiopharmaceuticals within 3 hr in 99% radiochemical purity

Ascorbic acid and melatonin reduce heat-induced performance inhibition and oxidative stress in Japanese quails.

Science.gov (United States)

Sahin, N; Onderci, M; Sahin, K; Gursu, M F; Smith, M O

2004-02-01

1. The effects of ascorbic acid (L-ascorbic acid) and melatonin supplementation on performance, carcase characteristics, malondialdehyde (MDA) as lipid peroxidation indicator, ascorbic acid, retinol, tocopherol and mineral status in the Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature were evaluated. 2. Two hundred and forty Japanese quails (10 d old) were randomly assigned to 8 treatment groups consisting of 10 replicates of three birds each. The birds were kept in a temperature-controlled room at 22 degrees C (Thermoneutral, TN groups) or 34 degrees C (for 8 h/d; 09:00 to 17:00 h; Heat stress, HS groups). Birds in both TN and HS were fed either a basal (control) diet or the basal diet supplemented with 250 mg of L-ascorbic acid/kg of diet (Ascorbic acid group), 40 mg of melatonin/kg of diet (Melatonin group) or both (Ascorbic acid + Melatonin group). 3. Supplementing heat-stressed quails with ascorbic acid and melatonin improved performance compared with the control group. Effects generally were greatest in quails supplemented with both ascorbic acid and melatonin. 4. Although supplementation did not consistently restore the concentrations of serum ascorbic acid, retinol and tocopherol to those of TN groups, these concentrations increased significantly with supplementation. Furthermore, serum and liver MDA and serum cholesterol and glucose concentrations were lower in the supplemented groups than in the heat-stressed controls. 5. Within each environment, excretion of Ca, P, Mg, Zn, Fe and Cr were lowest in the combination group and, in all cases, highest in the HS group. Interactions between diet and temperature were detected for live weight gain, cold carcase weight, MDA, ascorbic acid, tocopherol concentrations and excretion of zinc. 6. The results of the study indicate that ascorbic acid and melatonin supplementation attenuate the decline in performance and antioxidant and mineral status caused by heat stress and such

Inhibition of angiotensin I converting enzyme by subtilisin NAT (nattokinase) in natto, a Japanese traditional fermented food.

Science.gov (United States)

Murakami, Keiko; Yamanaka, Naoki; Ohnishi, Katsunori; Fukayama, Minoru; Yoshino, Masataka

2012-06-01

Angiotensin I converting enzyme (ACE) was inhibited by the culture medium of Bacillus subtilis subsp. natto, which ferments boiled soy beans to natto, a Japanese traditional food. Subtilisin NAT (nattokinase) produced by B. subtilis also inhibited ACE, and the inhibition was markedly stimulated by heat treatment of subtilisin at 120 °C for 15 min. Inhibition of ACE by subtilisin was of a mixed type: the decrease in V(max) and the increase in K(m) value. SDS-polyacrylamide gel electrophoresis showed that heat treatment of subtilisin caused inactivation with fragmentation of the enzyme protein into small peptides. The inhibitory action of subtilisin was not due to an enzymatic action of protease, but may be ascribed to the potent ACE-inhibitory peptides such as LY and FY, amino acid sequences in subtilisin. HPLC-MS analysis of heat-inactivated subtilisin confirmed that LY and FY were liberated by fragmentation of the enzyme. Inhibition of ACE by subtilisin and its degradation peptides such as LY and FY may participate in the suppression of blood pressure by ingestion of natto.

Arborvitae (Thuja plicata essential oil significantly inhibited critical inflammation- and tissue remodeling-related proteins and genes in human dermal fibroblasts

Directory of Open Access Journals (Sweden)

Xuesheng Han

2017-06-01

Full Text Available Arborvitae (Thuja plicata essential oil (AEO is becoming increasingly popular in skincare, although its biological activity in human skin cells has not been investigated. Therefore, we sought to study AEO's effect on 17 important protein biomarkers that are closely related to inflammation and tissue remodeling by using a pre-inflamed human dermal fibroblast culture model. AEO significantly inhibited the expression of vascular cell adhesion molecule 1 (VCAM-1, intracellular cell adhesion molecule 1 (ICAM-1, interferon gamma-induced protein 10 (IP-10, interferon-inducible T-cell chemoattractant (I-TAC, monokine induced by interferon gamma (MIG, and macrophage colony-stimulating factor (M-CSF. It also showed significant antiproliferative activity and robustly inhibited collagen-I, collagen-III, plasminogen activator inhibitor-1 (PAI-1, and tissue inhibitor of metalloproteinase 1 and 2 (TIMP-1 and TIMP-2. The inhibitory effect of AEO on increased production of these protein biomarkers suggests it has anti-inflammatory property. We then studied the effect of AEO on the genome-wide expression of 21,224 genes in the same cell culture. AEO significantly and diversely modulated global gene expression. Ingenuity pathway analysis (IPA showed that AEO robustly affected numerous critical genes and signaling pathways closely involved in inflammatory and tissue remodeling processes. The findings of this study provide the first evidence of the biological activity and beneficial action of AEO in human skin cells.

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

Science.gov (United States)

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

2018-02-08

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

Thermotolerance and protein glycosylation: Inhibition studies with sodium fluoride, azauridine and tunicamycin

International Nuclear Information System (INIS)

Bursey, D.L.; Henle, K.J.; Nagle, W.A.; Moss, A.J.

1987-01-01

The glycosylation hypothesis predicts increased incorporation of monosaccharides into 0-linked glycoproteins during thermotolerance development and inhibition of thermotolerance when this process is blocked. Specific inhibitors of 0-linked glycosylation are not available. The authors examined the effect of non-specific inhibition of glycosylation on thermotolerance development by: 1. restriction of both exogenous sugars and endogeneous sugar synthesis with NaF to block glycolysis while providing L-glutamine as a substrate for ATP synthesis in the TCA cycle; or 2. inhibition of UDP-sugar synthesis using azauridine and tunicamycin. Inhibitors were added to cell cultures after heat conditioning (10 min, 45 0 ) and removed after 6 hr prior to 45 0 -test heating. Sugar deprivation was achieved with 10mM NaF in glucose-free EBSS, supplemented with 2mM L-glutamine. Synthesis of UDP-sugars was inhibited with 1mM azauridine + 1μg/ml tunicamycin. Thermotolerance development was inhibited 87% by NaF/glutamine and 47% by azauridine/tunicamycin. For example, the D/sub o/ of the thermotolerant cells was 42.5 min (control D/sub o/ = 3 min), but only 5.5 min with inhibition by the NaF solution. These results support the absolute requirement of sugar precursors for thermotolerance development as predicted by the glycosylation hypothesis

Heat Stress-Induced PI3K/mTORC2-Dependent AKT Signaling Is a Central Mediator of Hepatocellular Carcinoma Survival to Thermal Ablation Induced Heat Stress.

Directory of Open Access Journals (Sweden)

Scott M Thompson

Full Text Available Thermal ablative therapies are important treatment options in the multidisciplinary care of patients with hepatocellular carcinoma (HCC, but lesions larger than 2-3 cm are plagued with high local recurrence rates and overall survival of these patients remains poor. Currently no adjuvant therapies exist to prevent local HCC recurrence in patients undergoing thermal ablation. The molecular mechanisms mediating HCC resistance to thermal ablation induced heat stress and local recurrence remain unclear. Here we demonstrate that the HCC cells with a poor prognostic hepatic stem cell subtype (Subtype HS are more resistant to heat stress than HCC cells with a better prognostic hepatocyte subtype (Subtype HC. Moreover, sublethal heat stress rapidly induces phosphoinositide 3-kinase (PI3K/mammalian target of rapamycin (mTOR dependent-protein kinase B (AKT survival signaling in HCC cells in vitro and at the tumor ablation margin in vivo. Conversely, inhibition of PI3K/mTOR complex 2 (mTORC2-dependent AKT phosphorylation or direct inhibition of AKT function both enhance HCC cell killing and decrease HCC cell survival to sublethal heat stress in both poor and better prognostic HCC subtypes while mTOR complex 1 (mTORC1-inhibition has no impact. Finally, we showed that AKT isoforms 1, 2 and 3 are differentially upregulated in primary human HCCs and that overexpression of AKT correlates with worse tumor biology and pathologic features (AKT3 and prognosis (AKT1. Together these findings define a novel molecular mechanism whereby heat stress induces PI3K/mTORC2-dependent AKT survival signaling in HCC cells and provide a mechanistic rationale for adjuvant AKT inhibition in combination with thermal ablation as a strategy to enhance HCC cell killing and prevent local recurrence, particularly at the ablation margin.

Behavioral inhibition and obsessive-compulsive disorder.

Science.gov (United States)

Coles, Meredith E; Schofield, Casey A; Pietrefesa, Ashley S

2006-01-01

Behavioral inhibition is frequently cited as a vulnerability factor for development of anxiety. However, few studies have examined the unique relationship between behavioral inhibition and obsessive-compulsive disorder (OCD). Therefore, the current study addressed the relationship between behavioral inhibition and OCD in a number of ways. In a large unselected student sample, frequency of current OC symptoms was significantly correlated with retrospective self-reports of total levels of childhood behavioral inhibition. In addition, frequency of current OC symptoms was also significantly correlated with both social and nonsocial components of behavioral inhibition. Further, there was evidence for a unique relationship between behavioral inhibition and OC symptoms beyond the relationship of behavioral inhibition and social anxiety. In addition, results showed that reports of childhood levels of behavioral inhibition significantly predicted levels of OCD symptoms in adulthood. Finally, preliminary evidence suggested that behavioral inhibition may be more strongly associated with some types of OC symptoms than others, and that overprotective parenting may moderate the impact of behavioral inhibition on OC symptoms. The current findings suggest the utility of additional research examining the role of behavioral inhibition in the etiology of OCD.

Effect of a Traditional Herbal Prescription, Kyung-Ok-Ko, on Male Mouse Spermatogenic Ability after Heat-Induced Damage

Directory of Open Access Journals (Sweden)

Deok-Sang Hwang

2015-01-01

Full Text Available Kyung-Ok-Ko (KOK, a well-known traditional Korean medicinal formula, has long been used to invigorate the essential qi. This use of KOK may be associated with reproductive ability as a more modern concept. The protective effect of KOK was evaluated against deterioration of testicular function induced by heat exposure in male mice. Male fertility was disrupted by scrotal heat stress at 43°C for 5 weeks. KOK (0.25, 0.50, and 2.00 g/kg/day was administered orally at 3 h after the stress. To evaluate the protective effect of KOK, body weight, testicular weight, sperm count, sperm motility, and histopathological changes in the testes were evaluated. KOK-treated mice significantly recovered their general health, as evidenced by body weight. KOK-treated mice also showed significantly higher testes weights, sperm counts, and sperm motility than did the heat stress group. KOK-treated mice significantly recovered the morphological appearance of the seminiferous tubules and seminiferous epithelium. Furthermore, KOK-treated mice significantly increased antioxidant enzyme activities and reduced the protein expressions of apoptosis in the testes. KOK significantly protects against heat-induced damage to testicular function in male mice by inhibiting oxidative stress and apoptosis, indicating that KOK may be an effective agent for treatment of heat-induced male infertility.

Enhancing Oxidative Stability of Sunflower Oil during Convective and Microwave Heating Using Grape Seed Extract

Directory of Open Access Journals (Sweden)

Mariana-Atena Poiana

2012-07-01

Full Text Available This study was performed to investigate the effectiveness of grape seed extract (GSE compared to butylated hydroxytoluene (BHT on retarding lipid oxidation of sunflower oil subjected to convection and microwave heating up to 240 min under simulated frying conditions. The progress of lipid oxidation was assessed in terms of peroxide value (PV, p-anisidine value (p-AV, conjugated dienes and trienes (CD, CT, inhibition of oil oxidation (IO and TOTOX value. In addition, total phenolic content (TP was evaluated in samples before and after heating in order to assess the changes in these compounds relative to the extent of lipid oxidation. The results of this study highlight that GSE showed a significantly inhibitory effect on lipid oxidation during both treatments, although to a different extent. This ability was dose-dependent; therefore, the extent of lipid oxidation was inversely related to GSE level. Convective heating, respective microwave exposure for 240 min of samples supplemented by GSE to a level of 1000 ppm, resulted in significant decreases of investigated indices relative to the control values as follows: PV (48%; 30%, p-AV (29%; 40%, CD (45%; 30%, CT (41%; 36%, TOTOX (35%; 37%. GSE to a level of 600–800 ppm inhibited the lipid oxidation in a similar manner to BHT. These results suggested that GSE can be used as a potential natural extract for improving oxidative stability of sunflower oil during thermal applications.

Design of serially connected ammonia-water hybrid absorption-compression heat pumps for district heating with the utilisation of a geothermal heat source

DEFF Research Database (Denmark)

Jensen, Jonas Kjær; Ommen, Torben Schmidt; Markussen, Wiebke Brix

2016-01-01

District heating (DH) can reduce the primary energy consumption in urban areas with significant heat demands. The design of a serially connected ammonia-water hybrid absorption-compression heat pump system was investigated for operation in the Greater Copenhagen DH network in Denmark, in order...... to supply 7.2 MW heat at 85 °C utilizing a geothermal heat source at 73 °C. Both the heat source and heat sink experience a large temperature change over the heat transfer process, of which a significant part may be achieved by direct heat exchange. First a generic study with a simple representation...

Slow brushing reduces heat pain in humans.

Science.gov (United States)

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

2017-08-01

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

Radiosensitization of normoxic and hypoxic h1339 lung tumor cells by heat shock protein 90 inhibition is independent of hypoxia inducible factor-1α.

Science.gov (United States)

Schilling, Daniela; Bayer, Christine; Li, Wei; Molls, Michael; Vaupel, Peter; Multhoff, Gabriele

2012-01-01

Ionizing irradiation is a commonly accepted treatment modality for lung cancer patients. However, the clinical outcome is hampered by normal tissue toxicity and tumor hypoxia. Since tumors often have higher levels of active heat shock protein 90 (Hsp90) than normal tissues, targeting of Hsp90 might provide a promising strategy to sensitize tumors towards irradiation. Hsp90 client proteins include oncogenic signaling proteins, cell cycle activators, growth factor receptors and hypoxia inducible factor-1α (HIF-1α). Overexpression of HIF-1α is assumed to promote malignant transformation and tumor progression and thus might reduce the accessibility to radiotherapy. Herein, we describe the effects of the novel Hsp90 inhibitor NVP-AUY922 and 17-allylamino-17-demethoxygeldanamycin (17-AAG), as a control, on HIF-1α levels and radiosensitivity of lung carcinoma cells under normoxic and hypoxic conditions. NVP-AUY922 exhibited a similar biological activity to that of 17-AAG, but at only 1/10 of the dose. As expected, both inhibitors reduced basal and hypoxia-induced HIF-1α levels in EPLC-272H lung carcinoma cells. However, despite a down-regulation of HIF-1α upon Hsp90 inhibition, sensitivity towards irradiation remained unaltered in EPLC-272H cells under normoxic and hypoxic conditions. In contrast, treatment of H1339 lung carcinoma cells with NVP-AUY922 and 17-AAG resulted in a significant up-regulation of their initially high HIF-1α levels and a concomitant increase in radiosensitivity. In summary, our data show a HIF-1α-independent radiosensitization of normoxic and hypoxic H1339 lung cancer cells by Hsp90 inhibition.

The kampo medicine Daikenchuto inhibits peritoneal fibrosis in mice.

Science.gov (United States)

Kitamura, Mineaki; Nishino, Tomoya; Obata, Yoko; Oka, Satoru; Abe, Shinichi; Muta, Kumiko; Ozono, Yoshiyuki; Koji, Takehiko; Kohno, Shigeru

2015-01-01

Long-term peritoneal dialysis therapy causes inflammation and histological changes in the peritoneal membrane. Inflammation generally activates fibroblasts and results in fibroblast-myofibroblast differentiation. Heat-shock protein 47 (HSP 47), a collagen-specific molecular chaperone, is localized in myofibroblasts and is involved in the progression of peritoneal fibrosis. Daikenchuto (DKT), a Kampo medicine, is used to prevent postoperative colon adhesion. It inhibits inflammation and HSP 47 expression in the gastrointestinal tract. We examined the effect of DKT on chlorhexidine gluconate (CG)-induced peritoneal fibrosis in mice injected with 0.1% CG dissolved in 15% ethanol. DKT was dissolved in the drinking water. Histological changes were assessed using Masson trichrome staining. Cells expressing α-smooth muscle actin (α-SMA), HSP 47, phospho-Smad 2/3, F4/80, and monocyte chemotactic protein-1 were examined immunohistochemically. Compared with the control group, the peritoneal tissues of the CG group were markedly thickened, and the number of cells expressing α-SMA, HSP 47, phospho-Smad 2/3, F4/80, and monocyte chemotactic protein-1 was significantly increased. However, these changes were inhibited in the DKT-treated group. These results indicate that DKT can prevent peritoneal fibrosis by inhibiting inflammation and HSP 47 expression.

Retardation of heat exchanger surfaces mineral fouling by water-based diethylenetriamine pentaacetate-treated CNT nanofluids

International Nuclear Information System (INIS)

Teng, K.H.; Amiri, Ahmad; Kazi, S.N.; Bakar, M.A.; Chew, B.T.; Al-Shamma’a, A.; Shaw, A.

2017-01-01

Highlights: • Decoration EDTA on MWCNT surface to retard the rate of fouling. • Preparation of DTPA-treated MWCNT/water nanofluid. • Evaluating the mitigation of DTPA-treated MWCNT-based water nanofluids. • Retarding of calcium carbonate crystals by MWCNT-DTPA additives. • The effect of additive on the rate of fouling. - Abstract: Mineral scale deposition on heat exchanging surfaces increases the thermal resistance and reduces the operating service life. The effect is usually intensified at higher temperatures due to the inverse temperature solubility characteristics of some minerals in the cooling water. Scale formation build up when dissolved salt crystallize from solution onto the heated surface, forming an adherent deposit. It is very important for heat transfer applications to cope with the fouling problems in industry. In this present study, a set of fouling experiments was conducted to evaluate the mitigation of calcium carbonate scaling by applying DTPA-treated MWCNT-based water nanofluids on heat exchanger surfaces. Investigation of additive DTPA-treated MWCNT-based water nanofluids (benign to the environment) on fouling rate of deposition was performed. 300 mg L −1 of artificially-hardened calcium carbonate solution was prepared as a fouling solution for deposit analysis. Assessment of the deposition of calcium carbonate on the heat exchanger surface with respect to the inhibition of crystal growth was conducted by Scanning Electron Microscope (SEM). The results showed that the formation of calcium carbonate crystals can be retarded significantly by adding MWCNT-DTPA additives as inhibition in the solution.

Inhibition of photosynthesis and bleaching of zooxanthellae by the coral pathogen Vibrio shiloi.

Science.gov (United States)

Ben-Haim, Y; Banim, E; Kushmaro, A; Loya, Y; Rosenberg, E

1999-06-01

Vibrio shiloi is the causative agent of bleaching (loss of endosymbiotic zooxanthellae) of the coral Oculina patagonica in the Mediterranean Sea. To obtain information on the mechanism of bleaching, we examined the effect of secreted material (AK1-S) produced by V. shiloi on zooxanthellae isolated from corals. AK1-S caused a rapid inhibition of photosynthesis of the algae, as measured with a Mini-PAM fluorometer. The inhibition of photosynthesis was caused by (i) ammonia produced during the growth of V. shiloi on protein-containing media and (ii) a non-dialysable heat-resistant factor. This latter material did not inhibit photosynthesis of the algae by itself but, when added to different concentrations of NH4Cl, enhanced the inhibition approximately two- to threefold. Ammonia and the enhancer were effective to different degrees on zooxanthellae isolated from four species of coral examined. In addition to the rapid inhibition of photosynthesis, AK1-S caused bleaching (loss of pigmentation) and lysis of zooxanthellae. Bleaching was more rapid than lysis, reaching a peak (25% bleached algae) after 6 h. The factors in AK1-S responsible for bleaching and lysis were different from those responsible for the inhibition of photosynthesis, because they were heat sensitive, non-dialysable and active in the dark. Thus, the coral pathogen V. shiloi produces an array of extracellular materials that can inhibit photosynthesis, bleach and lyse zooxanthellae.

Effect of heat treatment on antimycotic activity of Sahara honey

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Moussa Ahmed

2014-11-01

Full Text Available Objective: To evaluate the influence of the temperature on honey colour, polyphenol contents and antimycotic capacity and to evaluate the correlation between these parameters. Methods: Sahara honey were heated up to 25, 50, 75 and 100 °C for 15, 30 and 60 min, and their colour intensity, polyphenol contents and antimycotic capacity. The Folin-Ciocalteu test was used to determine the total polyphenol contents (TPC. The antimycotic activity was evaluated both by agar diffusion method and micro wells dilution method against the Candida albicans (C. albicans and Candida glabrata (C. glabrata. Results: Initial values for TPC in Sahara honey ranged from 0.55 to 1.14 mg of gallic acid per kg of honey, with the average value of 0.78 mg of gallic acid per kg of honey. The TPC values after heat-treatment were 0.54 to 1.54 with the average value of 1.49 mg. The minimal inhibitory concentrations before heat-treatment of Sahara honey against C. albicans and C. glabrata ranged from 3.06%-12.5% and 50% respectively. After heat-treatment the minimal inhibitory concentrations between 12.5% and 50% for C. albicans and C. glabrata, respectively. The diameters of inhibition zones of Sahara honey with 50% concentration varied from (12.67-15.00 mm by C. albicans to (14.33-15.67 mm by C. glabrata. The diameters of inhibition zones after heat-treatment at 25 and 50 °C for 15.30 and 60 min ranged from (2.00-18.67 mm by C. albicans to (8.00-16.67 mm by C. glabrata. Statistically significant relations between the TPC and the colour intensity of Sahara honey (r=0.99, P<0.05. Furthermore, the results showed that the TPC and colour is not correlated with the antimycotic capacity. Conclusions: To our knowledge this is the first report on the antimycotic capacity of Sahara honey.

Magnetic fields in laser heated plasmas

International Nuclear Information System (INIS)

Amiranoff, F.; Brackbill, J.; Colombant, D.; Grandjouan, N.

1984-01-01

With a fixed-ion code for the study of self-generated magentic fields in laser heated plasmas, the inhibition of thermal transport and the effect of the Nernst term are modeled for a KrF laser. For various values of the flux limiter, the response of a foil to a focused laser is calculated without a magnetic field and compared with the response calculated with a magnetic field. The results are: The Nernst term convects the magnetic field to densities above critical as found by Nishiguchi et al. (1984), but the field does not strongly inhibit transport into the foil. The field is also transported to sub-critical densities, where it inhibits thermal diffusion and enhance lateral transport by convection

Regenerative heat sources for heating networks

International Nuclear Information System (INIS)

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

2015-01-01

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

The open-ocean sensible heat flux and its significance for Arctic boundary layer mixing during early fall

Science.gov (United States)

Ganeshan, Manisha; Wu, Dong L.

2016-10-01

The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL) clouds and seasonal sea ice growth. The open-ocean sensible heat flux, a crucial mechanism of excessive ocean heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multi-year Japanese cruise-ship observations from R/V Mirai over the open Arctic Ocean to characterize the surface sensible heat flux (SSHF) during early fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum ocean-atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime), yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure) followed by the highly stable (stratus) regime. Overall, it can explain ˜ 10 % of the open-ocean BL height variability, whereas cloud-driven (moisture and radiative) mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the R/V Mirai for better understanding and

The open-ocean sensible heat flux and its significance for Arctic boundary layer mixing during early fall

Directory of Open Access Journals (Sweden)

M. Ganeshan

2016-10-01

Full Text Available The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL clouds and seasonal sea ice growth. The open-ocean sensible heat flux, a crucial mechanism of excessive ocean heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multi-year Japanese cruise-ship observations from R/V Mirai over the open Arctic Ocean to characterize the surface sensible heat flux (SSHF during early fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum ocean–atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime, yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure followed by the highly stable (stratus regime. Overall, it can explain  ∼  10 % of the open-ocean BL height variability, whereas cloud-driven (moisture and radiative mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the R/V Mirai for

The Open-Ocean Sensible Heat Flux and Its Significance for Arctic Boundary Layer Mixing During Early Fall

Science.gov (United States)

Ganeshan, Manisha; Wu, Dongliang

2016-01-01

The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL) clouds and seasonal sea ice growth. The open-ocean sensible heat flux, a crucial mechanism of excessive ocean heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multiyear Japanese cruise-ship observations from RV Mirai over the open Arctic Ocean to characterize the surface sensible heat flux (SSHF) during early fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum ocean-atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime), yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure) followed by the highly stable (stratus) regime. Overall, it can explain 10 of the open ocean BL height variability, whereas cloud-driven (moisture and radiative) mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the RV Mirai for better understanding and

Integration of Space Heating and Hot Water Supply in Low Temperature District Heating

DEFF Research Database (Denmark)

Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

2014-01-01

pipes, where the water is at the highest temperature. The heat loss may be lowered by decreasing the temperatures in the network for which reason low temperature networks are proposed as a low loss solution for future district heating. However, the heating demand of the consumers involve both domestic......District heating makes it possible to provide heat for many consumers in an efficient manner. In particular, district heating based on combined heat and power production is highly efficient. One disadvantage of district heating is that there is a significant heat loss from the pipes...... to the surrounding ground. In larger networks involving both transmission and distribution systems, the heat loss is most significant from the distribution network. An estimate is that about 80-90 % of the heat loss occurs in the distribution system. In addition, the heat loss is naturally highest from the forward...

The antitumor natural product tanshinone IIA inhibits protein kinase C and acts synergistically with 17-AAG.

Science.gov (United States)

Lv, Chao; Zeng, Hua-Wu; Wang, Jin-Xin; Yuan, Xing; Zhang, Chuang; Fang, Ting; Yang, Pei-Ming; Wu, Tong; Zhou, Yu-Dong; Nagle, Dale G; Zhang, Wei-Dong

2018-02-07

Tanshinone IIA (Tan IIA), the primary bioactive compound derived from the traditional Chinese medicine (TCM) Salvia miltiorrhiza Bunge, has been reported to possess antitumor activity. However, its antitumor mechanisms are not fully understood. To resolve the potential antitumor mechanism(s) of Tan IIA, its gene expression profiles from our database was analyzed by connectivity map (CMAP) and the CMAP-based mechanistic predictions were confirmed/validated in further studies. Specifically, Tan IIA inhibited total protein kinase C (PKC) activity and selectively suppressed the expression of cytosolic and plasma membrane PKC isoforms ζ and ε. The Ras/MAPK pathway that is closely regulated by the PKC signaling is also inhibited by Tan IIA. While Tan IIA did not inhibit heat shock protein 90 (Hsp90), it synergistically enhanced the antitumor efficacy of the Hsp90 inhibitors 17-AAG and ganetespib in human breast cancer MCF-7 cells. In addition, Tan IIA significantly inhibited PI3K/Akt/mTOR signaling, and induced both cell cycle arrest and autophagy. Collectively, these studies provide new insights into the molecular mechanisms responsible for antitumor activity of Tan IIA.

Temperature and Particle Size Dependence of Sodium Bicarbonate Inhibition of Methane/Air Flames.

Science.gov (United States)

1982-11-03

with thermal theories dating back to those of Mallard and Le Chatelier . They proposed that it was a propagation of heat back * ~ ~ -7 7 - 777* - . 41...inhibiting effects * can be separated in principle , the action of a given inhibiting agent does not have to fall exclusively in the realm of one or an- other

Heat-Killed Lactobacillus salivarius and Lactobacillus johnsonii Reduce Liver Injury Induced by Alcohol In Vitro and In Vivo.

Science.gov (United States)

Chuang, Cheng-Hung; Tsai, Cheng-Chih; Lin, En-Shyh; Huang, Chin-Shiu; Lin, Yun-Yu; Lan, Chuan-Ching; Huang, Chun-Chih

2016-10-31

The aim of the present study was to determine whether Lactobacillus salivarius (LS) and Lactobacillus johnsonii (LJ) prevent alcoholic liver damage in HepG2 cells and rat models of acute alcohol exposure. In this study, heat-killed LS and LJ were screened from 50 Lactobacillus strains induced by 100 mM alcohol in HepG2 cells. The severity of alcoholic liver injury was determined by measuring the levels of aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (γ-GT), lipid peroxidation, triglyceride (TG) and total cholesterol. Our results indicated that heat-killed LS and LJ reduced AST, ALT, γ-GT and malondialdehyde (MDA) levels and outperformed other bacterial strains in cell line studies. We further evaluated these findings by administering these strains to rats. Only LS was able to reduce serum AST levels, which it did by 26.2%. In addition LS significantly inhibited serum TG levels by 39.2%. However, both strains were unable to inhibit ALT levels. In summary, we demonstrated that heat-killed LS and LJ possess hepatoprotective properties induced by alcohol both in vitro and in vivo.

Heat-Killed Lactobacillus salivarius and Lactobacillus johnsonii Reduce Liver Injury Induced by Alcohol In Vitro and In Vivo

Directory of Open Access Journals (Sweden)

Cheng-Hung Chuang

2016-10-01

Full Text Available The aim of the present study was to determine whether Lactobacillus salivarius (LS and Lactobacillus johnsonii (LJ prevent alcoholic liver damage in HepG2 cells and rat models of acute alcohol exposure. In this study, heat-killed LS and LJ were screened from 50 Lactobacillus strains induced by 100 mM alcohol in HepG2 cells. The severity of alcoholic liver injury was determined by measuring the levels of aspartate transaminase (AST, alanine transaminase (ALT, gamma-glutamyl transferase (γ-GT, lipid peroxidation, triglyceride (TG and total cholesterol. Our results indicated that heat-killed LS and LJ reduced AST, ALT, γ-GT and malondialdehyde (MDA levels and outperformed other bacterial strains in cell line studies. We further evaluated these findings by administering these strains to rats. Only LS was able to reduce serum AST levels, which it did by 26.2%. In addition LS significantly inhibited serum TG levels by 39.2%. However, both strains were unable to inhibit ALT levels. In summary, we demonstrated that heat-killed LS and LJ possess hepatoprotective properties induced by alcohol both in vitro and in vivo.

Activating transcription factor-3 (ATF3) functions as a tumor suppressor in colon cancer and is up-regulated upon heat-shock protein 90 (Hsp90) inhibition

International Nuclear Information System (INIS)

Hackl, Christina; Stoeltzing, Oliver; Lang, Sven A; Moser, Christian; Mori, Akira; Fichtner-Feigl, Stefan; Hellerbrand, Claus; Dietmeier, Wolfgang; Schlitt, Hans J; Geissler, Edward K

2010-01-01

Activating transcription factor-3 (ATF3) is involved in the complex process of cellular stress response. However, its exact role in cancer is discussed controversially because both tumor suppressive and oncogenic effects have been described. Here we followed-up on our previous observation that inhibition of Hsp90 may increase ATF3 expression and sought to determine the role of ATF3 in colon cancer. Regulation of ATF3 was determined in cancer cells using signaling inhibitors and a heat-shock protein-90 (Hsp90) antagonist. Human HCT116 cancer cells were stably transfected with an ATF3-shRNA or a luciferase-shRNA expression plasmid and alterations in cell motility were assessed in migration assays. The impact of ATF3 down-regulation on cancer growth and metastasis were investigated in a subcutaneous tumor model, a model of hepatic tumor growth and in a model of peritoneal carcinomatosis. Human colon cancer tissues were analyzed for ATF3 expression. The results show that therapeutic Hsp90 inhibition substantially up-regulates the expression of ATF3 in various cancer cells, including colon, gastric and pancreatic cancer. This effect was evident both in vitro and in vivo. RNAi mediated knock-down of ATF3 in HCT116 colon cancer cells significantly increased cancer cell migration in vitro. Moreover, in xenogenic mouse models, ATF3 knock-down promoted subcutaneous tumor growth and hepatic metastasis, as well as peritoneal carcinomatosis. Importantly, ATF3 expression was lower in human colon cancer specimens, as compared to corresponding normal surrounding tissues, suggesting that ATF3 may represent a down-regulated tumor suppressor in colon cancer. In conclusion, ATF3 down-regulation in colon cancer promotes tumor growth and metastasis. Considering that blocking Hsp90 induces ATF3 expression, Hsp90 inhibition may represent a valid strategy to treat metastatic colon cancer by up-regulating this anti-metastatic transcription factor

Heat transfer capacity of heat pipes: An application in coalfield wildfire in China

Science.gov (United States)

Li, Bei; Deng, Jun; Xiao, Yang; Zhai, Xiaowei; Shu, Chi-Min; Gao, Wei

2018-06-01

Coalfield wildfires are serious catastrophes associated with mining activities. Generally, the coal wildfire areas have tremendous heat accumulation regions. Eliminating the internal heat is an effective method for coal wildfire control. In this study, high thermal conductivity component of a heat pipe (HP) was used for enhancing the heat dissipation efficiency and impeding heat accumulation. An experimental system was set up to analyze the thermal resistance network of the coal-HP system. A coal-HP heat removal model was also established for studying the heat transfer performance of HP on the coal pile. The HP exhibited outstanding cooling performance in the initial period, resulting in the highest temperature difference between the coal pile and ambient temperature. However, the effect of the HP on the distribution temperature of coal piles decreased with increasing distance. The largest decline in the coal temperature occurred in a 20-mm radius of the HP; the temperature decreased from 84.3 to 50.9 °C, a decline of 39.6%. The amount of energy transfer by the HP after 80 h was 1.0865, 2.1680, and 3.3649 MJ under the initial heat source temperatures of 100, 150, and 200 °C, respectively. The coal was governed below 80 °C with the HP under the experimental conditions. It revealed that the HP had a substantial effect on thermal removal and inhibited spontaneous coal combustion. In addition, this paper puts forward the technological path of HP to control typical coalfield wildfire. [Figure not available: see fulltext.

Curcumin Enhances Bortezomib Treatment of Myeloma by Inhibiting ...

African Journals Online (AJOL)

Purpose: To investigate whether curcumin augments bortezomib-induced apoptosis in myeloma cells (MM1.R line), and to explore the molecular mechanism with regard to heat shock protein 90 (HSP90) expression. Methods: MTT cell viability assay was used to assess growth inhibition of MM1.R cells at different ...

Properties of a polygalacturonase-inhibiting protein isolated from 'Oroblanco' grapefruit.

Science.gov (United States)

D'hallewin, Guy; Schirra, Mario; Powell, Ann L. T.; Greve, L. Carl; Labavitch, John M.

2004-03-01

Polygalacturonase inhibiting protein (PGIP) was extracted from 'Oroblanco' grapefruit type (triploid pummelo-grapefruit) albedo tissue, purified and partially characterized. Extraction was carried out at 4 degrees C with a high ionic strength extraction buffer. After dialysis and concentration by ultrafiltration the extract was chromatographed on concanavalin A-Sepharose. The PGIP activity was bound by the lectin and then eluted using 250 mM alpha-methyl mannopyranoside, resulting in a 17-fold purification of the PGIP and demonstrating its glycoprotein nature. The anion-exchange and size-exclusion chromatography steps that followed gave a PGIP that was 857-fold purified relative to the initial tissue extract, and having a 44 kDa molecular weight, as estimated by SDS-PAGE electrophoresis. PGIP inhibition activity was tested with endo-polygalacturonase (EC 3.2.1.15) produced by Penicillium italicum and Botrytis cinerea. The radial diffusion and reducing sugar assays showed that P. italicum and B. cinerea endo-PGs were affected by PGIP, whereas no endo-PG activity was detected in the culture filtrate of P. digitatum. In vitro tests revealed that PGIP inhibited P. italicum and B. cinerea growth. By contrast, the influence of PGIP on P. digitatum, growth was negligible, perhaps because this fungus does not produce endo-PG. Following heating for 10 min at 65 degrees C the inhibitory activity of PGIP was reduced by 43%. PGIP activity decreased further as heating temperature increased, and was completely suppressed after heating at 100 degrees C for 10 min.

Enhanced inhibition of Aspergillus niger on sedge (Lepironia articulata) treated with heat-cured lime oil.

Science.gov (United States)

Matan, N; Matan, N; Ketsa, S

2013-08-01

This study aimed to examine heat curing effect (30-100°C) on antifungal activities of lime oil and its components (limonene, p-cymene, β-pinene and α-pinene) at concentrations ranging from 100 to 300 μl ml(-1) against Aspergillus niger in microbiological medium and to optimize heat curing of lime oil for efficient mould control on sedge (Lepironia articulata). Broth dilution method was employed to determine lime oil minimum inhibitory concentration, which was at 90 μl ml(-1) with heat curing at 70°C. Limonene, a main component of lime oil, was an agent responsible for temperature dependencies of lime oil activities observed. Response surface methodology was used to construct the mathematical model describing a time period of zero mould growth on sedge as functions of heat curing temperature and lime oil concentration. Heat curing of 90 μl ml(-1) lime oil at 70°C extended a period of zero mould growth on sedge to 18 weeks under moist conditions. Heat curing at 70°C best enhanced antifungal activity of lime oil against A. niger both in medium and on sedge. Heat curing of lime oil has potential to be used to enhance the antifungal safety of sedge products. © 2013 The Society for Applied Microbiology.

Interpreting the clinical significance of the differential inhibition of cyclooxygenase-1 and cyclooxygenase-2

NARCIS (Netherlands)

Brooks, P; Emery, P; Evans, JF; Fenner, H; Hawkey, CJ; Patrono, C; Smolen, J; Breeveld, F; Day, R; Dougados, M; Ehrich, EW; Gijon-Banos, J; Kvien, TK; Van Rijswijk, MH; Warner, T; Zeidler, H

The International Consensus Meeting on the Mode of Action of COX-2 Inhibition (ICMMAC) brought together 17 international experts in arthritis, gastroenterology and pharmacology on 5-6 December 1997. The meeting was convened to provide a definition of COX-2 specificity and to consider the clinical

Winter-regime surface heat loss from heated streams

International Nuclear Information System (INIS)

Paily, P.P.; Macagno, E.O.; Kennedy, J.F.

1974-01-01

Evaluation of the rate of surface heat exchange between the water and air is a significant factor in any study of the thermal response of heated streams to heat inputs. Existing methods to determine the amount of heat transfer across the water surface are surveyed, and the different formulas developed for determining the heat exchange components are compiled. Heat-transfer models that have been proposed in the literature are reviewed, and a new linearized model for determining the rate of surface heat exchange is proposed. Generalized relations between the major climatological factors and the coefficients of the linearized heat-loss rate are established by multiple-regression analysis. The analysis is limited to cold-period conditions, in the sense that air temperatures below the freezing point of water only are considered in developing the regression equations. A computer program, using FORTRAN, is presented which enables the computation of the coefficients appearing in the linearized heat-loss rate for all combinations of the various climatological factors

Biophoton emission induced by heat shock.

Directory of Open Access Journals (Sweden)

Katsuhiro Kobayashi

Full Text Available Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observed to increase in response to elevated temperatures, pretreatment at lower high temperatures inhibited photon emission at higher temperatures. Biophoton measurements are useful for observing and evaluating heat shock.

KSHV inhibits stress granule formation by viral ORF57 blocking PKR activation.

Directory of Open Access Journals (Sweden)

Nishi R Sharma

2017-10-01

Full Text Available TIA-1 positive stress granules (SG represent the storage sites of stalled mRNAs and are often associated with the cellular antiviral response. In this report, we provide evidence that Kaposi's sarcoma-associated herpesvirus (KSHV overcomes the host antiviral response by inhibition of SG formation via a viral lytic protein ORF57. By immunofluorescence analysis, we found that B lymphocytes with KSHV lytic infection are refractory to SG induction. KSHV ORF57, an essential post-transcriptional regulator of viral gene expression and the production of new viral progeny, inhibits SG formation induced experimentally by arsenite and poly I:C, but not by heat stress. KSHV ORF37 (vSOX bearing intrinsic endoribonuclease activity also inhibits arsenite-induced SG formation, but KSHV RTA, vIRF-2, ORF45, ORF59 and LANA exert no such function. ORF57 binds both PKR-activating protein (PACT and protein kinase R (PKR through their RNA-binding motifs and prevents PACT-PKR interaction in the PKR pathway which inhibits KSHV production. Consistently, knocking down PKR expression significantly promotes KSHV virion production. ORF57 interacts with PKR to inhibit PKR binding dsRNA and its autophosphorylation, leading to inhibition of eIF2α phosphorylation and SG formation. Homologous protein HSV-1 ICP27, but not EBV EB2, resembles KSHV ORF57 in the ability to block the PKR/eIF2α/SG pathway. In addition, KSHV ORF57 inhibits poly I:C-induced TLR3 phosphorylation. Altogether, our data provide the first evidence that KSHV ORF57 plays a role in modulating PKR/eIF2α/SG axis and enhances virus production during virus lytic infection.

Maximum skin hyperaemia induced by local heating: possible mechanisms.

Science.gov (United States)

Gooding, Kim M; Hannemann, Michael M; Tooke, John E; Clough, Geraldine F; Shore, Angela C

2006-01-01

Maximum skin hyperaemia (MH) induced by heating skin to > or = 42 degrees C is impaired in individuals at risk of diabetes and cardiovascular disease. Interpretation of these findings is hampered by the lack of clarity of the mechanisms involved in the attainment of MH. MH was achieved by local heating of skin to 42-43 degrees C for 30 min, and assessed by laser Doppler fluximetry. Using double-blind, randomized, placebo-controlled crossover study designs, the roles of prostaglandins were investigated by inhibiting their production with aspirin and histamine, with the H1 receptor antagonist cetirizine. The nitric oxide (NO) pathway was blocked by the NO synthase inhibitor, NG-nitro-L-arginine methyl esther (L-NAME), and enhanced by sildenafil (prevents breakdown of cGMP). MH was not altered by aspirin, cetirizine or sildenafil, but was reduced by L-NAME: median placebo 4.48 V (25th, 75th centiles: 3.71, 4.70) versus L-NAME 3.25 V (3.10, 3.80) (p = 0.008, Wilcoxon signed rank test). Inhibition of NO production (L-NAME) resulted in a more rapid reduction in hyperaemia after heating (p = 0.011), whereas hyperaemia was prolonged in the presence of sildenafil (p = 0.003). The increase in skin blood flow was largely confined to the directly heated area, suggesting that the role of heat-induced activation of the axon reflex was small. NO, but not prostaglandins, histamine or an axon reflex, contributes to the increase in blood flow on heating and NO is also a component of the resolution of MH after heating. Copyright 2006 S. Karger AG, Basel.

Expression profiles of two small heat shock proteins and antioxidant enzyme activity in Mytilus galloprovincialis exposed to cadmium at environmentally relevant concentrations

Science.gov (United States)

You, Liping; Ning, Xuanxuan; Chen, Leilei; Zhang, Linbao; Zhao, Jianmin; Liu, Xiaoli; Wu, Huifeng

2014-03-01

Small heat shock proteins encompass a widespread but diverse class of proteins, which play key roles in protecting organisms from various stressors. In the present study, the full-length cDNAs of two small heat shock proteins (MgsHSP22 and MgsHSP24.1) were cloned from Mytilus galloprovincialis, which encoded peptides of 181 and 247 amino acids, respectively. Both MgsHSP22 and MgsHSP24.1 were detected in all tissues examined by real-time PCR, with the highest expression being observed in muscle and gonad tissues. The real-time PCR results revealed that Cd significantly inhibited MgsHSP22 expression at 24 h and MgsHSP24.1 at 24 and 48 h under 5 μg/L Cd 2+ exposure. MgsHSP24.1 expression was also significantly inhibited after 50 μg/L Cd2+ exposure for 48 h. With regard to antioxidant enzymes, increased GPx and CAT activity were detected under Cd2+ stress (5 and 50 μg/L), while no significant difference in SOD activity was observed throughout the experiment. Overall, both MgsHsps and antioxidant enzymes revealed their potential as Cd stress biomarkers in M. galloprovincialis.

Mini-review: Inhibition of biofouling by marine microorganisms.

Science.gov (United States)

Dobretsov, Sergey; Abed, Raeid M M; Teplitski, Max

2013-01-01

Any natural or artificial substratum exposed to seawater is quickly fouled by marine microorganisms and later by macrofouling species. Microfouling organisms on the surface of a substratum form heterogenic biofilms, which are composed of multiple species of heterotrophic bacteria, cyanobacteria, diatoms, protozoa and fungi. Biofilms on artificial structures create serious problems for industries worldwide, with effects including an increase in drag force and metal corrosion as well as a reduction in heat transfer efficiency. Additionally, microorganisms produce chemical compounds that may induce or inhibit settlement and growth of other fouling organisms. Since the last review by the first author on inhibition of biofouling by marine microbes in 2006, significant progress has been made in the field. Several antimicrobial, antialgal and antilarval compounds have been isolated from heterotrophic marine bacteria, cyanobacteria and fungi. Some of these compounds have multiple bioactivities. Microorganisms are able to disrupt biofilms by inhibition of bacterial signalling and production of enzymes that degrade bacterial signals and polymers. Epibiotic microorganisms associated with marine algae and invertebrates have a high antifouling (AF) potential, which can be used to solve biofouling problems in industry. However, more information about the production of AF compounds by marine microorganisms in situ and their mechanisms of action needs to be obtained. This review focuses on the AF activity of marine heterotrophic bacteria, cyanobacteria and fungi and covers publications from 2006 up to the end of 2012.

Alternative solutions for inhibiting Legionella in domestic hot water systems based on low-temperature district heating

DEFF Research Database (Denmark)

Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

2015-01-01

Abstract District heating is a cost-effective way of providing heat to high heat density areas. Low-temperature district heating (LTDH) is a promising way to make district heating more energy-efficient and adaptable to well-insulated buildings with low heating demand in the future. However, one c...... systems. They have the additional benefit of reducing the heat loss of the hot water system. The alternative design solutions both enrich our options for water sanitation and improve the energy efficiency of our energy systems....... concern is the multiplication of Legionella due to insufficient temperature elevation with low-temperature supply. The aim of this study was to find optimal solutions to this dilemma for specific situations. The solutions were of two types: alternative system designs and various methods of sterilization...... methods, thermal treatment, ionization, chlorine, chlorine dioxide, ultraviolet light, photocatalysis and filtration are discussed as the most frequently used methods in hot water systems. The characteristics, efficacy and operation methods of LTDH using the solutions investigated are documented...

CELLS OVEREXPRESSING HSP27 SHOW ACCELERATED RECOVERY FROM HEAT-INDUCED NUCLEAR-PROTEIN AGGREGATION

NARCIS (Netherlands)

KAMPINGA, HH; BRUNSTING, JF; STEGE, GJJ; KONINGS, AWT; LANDRY, J

1994-01-01

Protein denaturation/aggregation upon cell exposure to heat shock is a likely cause of cell death. in the nucleus, protein aggregation has often been correlated to inhibition of nuclear located processes and heat-induced cell killing. in Chinese hamster 023 cells made thermotolerant by a prior

Food crops face rising temperatures: An overview of responses, adaptive mechanisms, and approaches to improve heat tolerance

Directory of Open Access Journals (Sweden)

Neeru Kaushal

2016-12-01

Full Text Available The rising temperatures are resulting in heat stress for various agricultural crops to limit their growth, metabolism, and leading to significant loss of yield potential worldwide. Heat stress adversely affects normal plant growth and development depending on the sensitivity of each crop species. Each crop species has its own range of temperature maxima and minima at different developmental stages beyond which all these processes get inhibited. The reproductive stage is on the whole more sensitive to heat stress, resulting in impaired fertilization to cause abortion of flowers. During seed filling, heat stress retards seed growth by affecting all the biochemical events to reduce seed size. Unfavorable temperature may significantly affect photosynthesis, respiration, water balance, and membrane stability of leaves. To combat heat stress, plants acquire various defense mechanisms for their survival such as maintaining membrane stability, and scavenging reactive oxygen species by generating antioxidants and stress proteins. Thermo-tolerance can be improved by the accumulation of various compounds of low molecular mass known as thermo-protectants as well as phyto-hormones. Exogenous application of these molecules has benefited plants growing under heat stress. Alternatively, transgenic plants over-expressing the enzymes catalyzing the synthesis of these molecules may be raised to increase their endogenous levels to improve heat tolerance. In recent times, various transgenics have been developed with improved thermo-tolerance having potential benefits for inducing heat tolerance in food crops. Updated information about of the effects of heat stress on various food crops and their responses as well as adaptive mechanisms is reviewed here.

Wind power integration using individual heat pumps – Analysis of different heat storage options

DEFF Research Database (Denmark)

Hedegaard, Karsten; Mathiesen, Brian Vad; Lund, Henrik

2012-01-01

Significant installations of individual heat pumps are expected in future energy systems due to their economic competitiveness. This case study of the Danish energy system in 2020 with 50% wind power shows that individual heat pumps and heat storages can contribute to the integration of wind power....... Heat accumulation tanks and passive heat storage in the construction are investigated as two alternative storage options in terms of their ability to increase wind power utilisation and to provide cost-effective fuel savings. Results show that passive heat storage can enable equivalent to larger...... reductions in excess electricity production and fuel consumption than heat accumulation tanks. Moreover, passive heat storage is found to be significantly more cost-effective than heat accumulation tanks. In terms of reducing fuel consumption of the energy system, the installation of heat pumps is the most...

Excision of x-ray-induced thymine damage in chromatin from heated cells

International Nuclear Information System (INIS)

Warters, R.L.; Roti Roti, J.L.

1979-01-01

Experiments were performed to distinguish between two possible modes of hyperthermia-induced inhibition of thymine base damage excision from the DNA of CHO cells: (1) heat denaturation of excision enzyme(s) or (2) heat-induced alteration of the substrate for damage excision (chromatin). While hyperthermia (45 0 C, 15 min) had no apparent effect on the capacity of the excision enzymes to excise damage from DNA it had a dramatic effect (ca. 80% inhibition) on the ability of chromatin to serve as a substrate for unheated enzymes. These results suggest that hyperthermia-induced radiosensitization of CHO cells may be due primarily to lesions in the cellular chromatin

Simultaneousness of room heating and ventilation air heating

International Nuclear Information System (INIS)

Mathisen, Hans Martin

2006-01-01

The report is part of NTNU-SINTEF's Smart Buildings program, Smart Energy Efficient Buildings (2002-2006), subprogram 3.1 Heating, ventilation and cooling systems. An important part of this subprogram is the development and implementation of heating distribution systems with low return temperature. A comparison has been made of the simultaneousness of room heating and ventilation air heating in six buildings. Existing measuring data with hourly measurements of effect requirements for the different purposes have been employed. Based on the measuring data the relation between the requirements for room heating and ventilation is estimated. A 'fictitious' return temperature has also been estimated. The result shows a significant variation between the buildings. For all there are short periods where the efficiency need for room heating and ventilation is equal (ml)

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

Science.gov (United States)

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

2017-09-01

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

Controlling the heating mode of heat pumps with the TRIANA three step methodology

NARCIS (Netherlands)

Toersche, Hermen; Bakker, Vincent; Molderink, Albert; Nykamp, Stefan; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2012-01-01

Heat pump based heating systems are increasingly becoming an economic and efficient alternative for domestic gas heating systems. Concentrations of heat pump installations do consume large amounts of electricity, causing significant grid distribution and stability issues when the diversity factor is

Propofol alleviate oxidative stress and mitochondrial damage in endothelial cells after heat stress

Directory of Open Access Journals (Sweden)

Li LI

2017-08-01

Full Text Available Objective To explore the protective effect of propofol on endothelial cells during heat stress and its protective effect to mitochondra. Methods Heat stress model of human umbilical vein endothelial cell was established when cells were incubated at 43℃ for 2h, then further incubted at 37℃, 5%CO2 for 6h. The experimental group was subdivided into six groups, including 37℃ group, 37℃ plus intralipid group (negative control group, 37℃ plus propofol group, 43℃ plus propofol group, 43℃ plus intralipid group, H2O2 plus propofol group (positive control group; Pretreated with 50μmol/L propofol, 0.2ml intralipid or 25μmol/L H2O2 before heat stress at 43℃, while the cells in the control group were incubated at 37℃. Cell viability was tested by CCK-8. ROS, mitochondrial membrane potential and the changes in mitochondrial permeability transition pore were determined by flow cytometry. The level of ATP was detected by fluorescein-luciferase. The changes of caspase-9 and caspase-3 were analyzed by Caspase Activity Assay Kit. Results HUVESs cell viability and damage of mitochondra were significantly decreased after heat stress. Compared with 43℃ heat stress group, pretreatment with propofol induced the recovery of cell viability and the ROS levels were significantly decreased in HUVEC cells (P<0.05. Meanwhile, the number of cells representing the decrease of mitochondrial membrane potential (the proportion of JC-1 monomer was significantly decreased (P<0.05 by propofol. The average fluorescence intensity of calcein which representing the MPTP changes and intracellular ATP content was significantly increased (P<0.05. In addition, the activation of mitochondrial apoptotic pathway mediated by caspase-9/3 was also inhibited. Conclusions Propofol have anti-oxidative, anti-apoptosis and mitochondria protective effect against endothelial cell injury during heat stress. DOI: 10.11855/j.issn.0577-7402.2017.06.04

Solar heating as a major source of energy for Australia

Energy Technology Data Exchange (ETDEWEB)

Morse, R. N.

1977-07-01

Solar energy can make its most effective contribution to Australian primary energy in the form of heat for industrial applications. About 50% of all end use energy is required as heat and it is estimated that 40% of this amounting to 1 EJ/a by 2000 could be supplied by solar heat generating systems. This would be 12% of estimated primary energy requirements by that time, and could help reduce the country's increasing dependence on imported oil. Energy self-sufficiency for Australia is possible, based on coal, solar energy and natural gas as primary energy sources. The reason for the present orientation towards residential solar water heaters is that there are many places where electric power for water heating costs between 2 and 4 cents per kWh which makes a solar water heater an attractive proposition. There is also a growing interest in the solar heating of swimming pools, mostly for private homes but also in larger installations for public and institutional pools. Industrial applications, on the other hand, are inhibited by the current low energy prices in Australia, which in some cases are around 0.13 cents/MJ (.47 cents/kWh). Industry, however, uses 40% of Australian primary energy, and represents by far the greatest potential for solar heat generating systems. Demonstration plants are being planned to obtain data on capital and running costs, and at the same time build up professional design and constructional skills in this area. The first demonstration solar industrial process heating system was commissioned in December 1976 and supplies portion of the heat requirements of a soft drink plant in conjunction with the existing oil fired boiler. Integrated solar/oil fired systems of this sort ensure continuous operation of the plant and over a year can result in significant oil savings.

Solar heating as a major source of energy for Australia

Energy Technology Data Exchange (ETDEWEB)

Morse, R.N.

1977-07-01

Solar energy can make its most effective contribution to Australian primary energy in the form of heat for industrial applications. About 50% of all end use energy is required as heat and it is estimated that 40% of this amounting to 1 EJ/a by 2000 could be supplied by solar heat generating systems. This would be 12% of estimated primary energy requirements by that time, and could help reduce the country's increasing dependence on imported oil. Energy self-sufficiency for Australia is possible, based on coal, solar energy and natural gas as primary energy sources. The reason for the present orientation towards residential solar water heaters is that there are many places where electric power for water heating costs between 2 and 4 cents per kWh which makes a solar water heater an attractive proposition. There is also a growing interest in the solar heating of swimming pools, mostly for private homes but also in larger installations for public and institutional pools. Industrial applications, on the other hand, are inhibited by the current low energy prices in Australia, which in some cases are around 0.13 cents/MJ (.47 cents/kWh). Industry, however, uses 40% of Australian primary energy, and represents by far the greatest potential for solar heat generating systems. Demonstration plants are being planned to obtain data on capital and running costs, and at the same time build up professional design and constructional skills in this area. The first demonstration solar industrial process heating system was commissioned in December 1976 and supplies portion of the heat requirements of a soft drink plant in conjunction with the existing oil fired boiler. Integrated solar/oil fired systems of this sort ensure continuous operation of the plant and over a year can result in significant oil savings.

Growth Inhibition of Re-Challenge B16 Melanoma Transplant by Conjugates of Melanogenesis Substrate and Magnetite Nanoparticles as the Basis for Developing Melanoma-Targeted Chemo-Thermo-Immunotherapy

Directory of Open Access Journals (Sweden)

Tomoaki Takada

2009-01-01

Full Text Available Melanogenesis substrate, N-propionyl-cysteaminylphenol (NPrCAP, is selectively incorporated into melanoma cells and inhibits their growth by producing cytotoxic free radicals. Magnetite nanoparticles also disintegrate cancer cells and generate heat shock protein (HSP upon exposure to an alternating magnetic field (AMF. This study tested if a chemo-thermo-immunotherapy (CTI therapy strategy can be developed for better management of melanoma by conjugating NPrCAP on the surface of magnetite nanoparticles (NPrCAP/M. We examined the feasibility of this approach in B16 mouse melanoma and evaluated the impact of exposure temperature, frequency, and interval on the inhibition of re-challenged melanoma growth. The therapeutic protocol against the primary transplanted tumor with or without AMF exposure once a day every other day for a total of three treatments not only inhibited the growth of the primary transplant but also prevented the growth of the secondary, re-challenge transplant. The heat-generated therapeutic effect was more significant at a temperature of 43∘C than either 41∘C or 46∘C. NPrCAP/M with AMF exposure, instead of control magnetite alone or without AMF exposure, resulted in the most significant growth inhibition of the re-challenge tumor and increased the life span of the mice. HSP70 production was greatest at 43∘C compared to that with 41∘C or 46∘C. CD+T cells were infiltrated at the site of the re-challenge melanoma transplant.

Simple model of inhibition of chain-branching combustion processes

Science.gov (United States)

Babushok, Valeri I.; Gubernov, Vladimir V.; Minaev, Sergei S.; Miroshnichenko, Taisia P.

2017-11-01

A simple kinetic model has been suggested to describe the inhibition and extinction of flame propagation in reaction systems with chain-branching reactions typical for hydrocarbon systems. The model is based on the generalised model of the combustion process with chain-branching reaction combined with the one-stage reaction describing the thermal mode of flame propagation with the addition of inhibition reaction steps. Inhibitor addition suppresses the radical overshoot in flame and leads to the change of reaction mode from the chain-branching reaction to a thermal mode of flame propagation. With the increase of inhibitor the transition of chain-branching mode of reaction to the reaction with straight-chains (non-branching chain reaction) is observed. The inhibition part of the model includes a block of three reactions to describe the influence of the inhibitor. The heat losses are incorporated into the model via Newton cooling. The flame extinction is the result of the decreased heat release of inhibited reaction processes and the suppression of radical overshoot with the further decrease of the reaction rate due to the temperature decrease and mixture dilution. A comparison of the results of modelling laminar premixed methane/air flames inhibited by potassium bicarbonate (gas phase model, detailed kinetic model) with the results obtained using the suggested simple model is presented. The calculations with the detailed kinetic model demonstrate the following modes of combustion process: (1) flame propagation with chain-branching reaction (with radical overshoot, inhibitor addition decreases the radical overshoot down to the equilibrium level); (2) saturation of chemical influence of inhibitor, and (3) transition to thermal mode of flame propagation (non-branching chain mode of reaction). The suggested simple kinetic model qualitatively reproduces the modes of flame propagation with the addition of the inhibitor observed using detailed kinetic models.

Quercetin suppresses heat shock-induced nuclear translocation of Hsp72

Directory of Open Access Journals (Sweden)

Antoni Gawron

2011-08-01

Full Text Available The effect of quercetin and heat shock on the Hsp72 level and distribution in HeLa cells was studied by Western blotting, indirect immunofluorescence and immunogold electron microscopy. In control cells and after quercetin treatment, Hsp72 was located both in the cytoplasm and in the nucleus in comparable amounts. After hyperthermia, the level of nuclear Hsp72 raised dramatically. Expression of Hsp72 in cytoplasm was also higher but not to such extent as that observed in the nucleus. Preincubation of heated cells with quercetin inhibited strong Hsp72 expression observed after hyperthermia and changed the intracellular Hsp72 distribution. The cytoplasmic level of protein exceeded the nuclear one, especially around the nucleus, where the coat of Hsp72 was noticed. Observations indicating that quercetin was present around and in the nuclear envelope suggested an involvement of this drug in the inhibition of nuclear translocation. Our results indicate that pro-apoptotic activity of quercetin may be correlated not only with the inhibition of Hsp72 expression but also with suppression of its migration to the nucleus.

Heat generated by knee prostheses.

Science.gov (United States)

Pritchett, James W

2006-01-01

Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

Heat Roadmap Europe

DEFF Research Database (Denmark)

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

2015-01-01

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

Circulating Heat Shock Proteins in Women With a History of Recurrent Vulvovaginitis

Directory of Open Access Journals (Sweden)

P. C. Giraldo

1999-01-01

70-kDa heat shock proteins (hsp60 and hsp70, respectively in the circulation of women with or without a history of recurrent BV or candidal vaginitis and with or without a current lower genital tract infection. Heat shock protein expression is associated with a down-regulation of proinflammatory immune responses that would inhibit microbial infection.

Effect of mineral matter on coal self-heating rate

Energy Technology Data Exchange (ETDEWEB)

B. Basil Beamish; Ahmet Arisoy [University of Queensland, Brisbane, Qld. (Australia). School of Engineering

2008-01-15

Adiabatic self-heating tests have been conducted on subbituminous coal cores from the same seam profile, which cover a mineral matter content range of 11.2-71.1%. In all cases the heat release rate does not conform to an Arrhenius kinetic model, but can best be described by a third order polynomial. Assessment of the theoretical heat sink effect of the mineral matter in each of the tests reveals that the coal is less reactive than predicted using a simple energy conservation equation. There is an additional effect of the mineral matter in these cases that cannot be explained by heat sink alone. The disseminated mineral matter in the coal is therefore inhibiting the oxidation reaction due to physicochemical effects. 14 refs., 5 figs., 5 tabs.

Urban district heating using nuclear heat - a survey

International Nuclear Information System (INIS)

Beresovski, T.; Oliker, I.

1979-01-01

The use of heat from nuclear power plants is of great interest in connection with projected future expansions of large urban district heating systems. Oil price escalation and air pollution from increased burning of fossil fuels are substantial incentivers for the adoption of nuclear heat and power plants. The cost of the hot water piping system from the nuclear plant to the city is a major factor in determining the feasibility of using nuclear heat. To achieve reasonable costs, the heat load should be at least 1500 MW(th), transport temperatures 125-200 0 C and distances preferably 50 km or less. Heat may be extracted from the turbines of conventional power reactors. Alternatively, some special-purpose smaller reactors are under development which are specially suited to production of heat with little or no power coproduct. Many countries are conducting studies of future expansions of district heating systems to use nuclear heat. Several countries are developing technology suitable for this application. Actual experience with the use of nuclear heat for district heating is currently being gained only in the USSR, however. While district heating appears to be a desirable technology at a time of increasing fossil-fuel costs, the use of nuclear heat will require siting of nuclear plants within transmission radius of cities. The institutional barries toward use of nuclear heating will have to be overcome before the energy conservation potential of this approach can be realized on a significant scale. (author)

Calorie Restriction Effect of Heat-Processed Onion Extract (ONI Using In Vitro and In Vivo Animal Models

Directory of Open Access Journals (Sweden)

Yu-Ri Kang

2018-03-01

Full Text Available Onion (Allium cepa L. is widely consumed as food or medicinal plant due to its well-defined health benefits. The antioxidant and antihyperlipidemic effects of onion and its extracts have been reported well. However, very limited information on anti-hyperglycemic effect is available in processed onion extracts. In our previous study, we reported that Amadori rearrangement compounds (ARCs produced by heat-processing in Korean ginseng can reduce carbohydrate absorption by inhibiting intestinal carbohydrate hydrolyzing enzymes in both in vitro and in vivo animal models. To prove the enhancement of anti-hyperglycemic effect and ARCs content by heat-processing in onion extract, a correlation between the anti-hyperglycemic activity and the total content of ARCs of heat-processed onion extract (ONI was investigated. ONI has a high content of ARCs and had high rat small intestinal sucrase inhibitory activity (0.34 ± 0.03 mg/mL, IC50 relevant for the potential management of postprandial hyperglycemia. The effect of ONI on the postprandial blood glucose increase was investigated in Sprague Dawley (SD rats fed on sucrose or starch meals. The maximum blood glucose levels (Cmax of heat-processed onion extract were significantly decreased by about 8.7% (from 188.60 ± 5.37 to 172.27 ± 3.96, p < 0.001 and 14.2% (from 204.04 ± 8.73 to 175.13 ± 14.09, p < 0.01 in sucrose and starch loading tests, respectively. These results indicate that ARCs in onion extract produced by heat-processing have anti-diabetic effect by suppressing carbohydrate absorption via inhibition of intestinal sucrase, thereby reducing the postprandial increase of blood glucose. Therefore, enhancement of ARCs in onion by heat-processing might be a good strategy for the development of the new product on the management of hyperglycemia.

Application of heat pipes in nuclear reactors for passive heat removal

Energy Technology Data Exchange (ETDEWEB)

Haque, Z.; Yetisir, M., E-mail: haquez@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2013-07-01

This paper introduces a number of potential heat pipe applications in passive (i.e., not requiring external power) nuclear reactor heat removal. Heat pipes are particularly suitable for small reactors as the demand for heat removal is significantly less than commercial nuclear power plants, and passive and reliable heat removal is required. The use of heat pipes has been proposed in many small reactor designs for passive heat removal from the reactor core. This paper presents the application of heat pipes in AECL's Nuclear Battery design, a small reactor concept developed by AECL. Other potential applications of heat pipes include transferring excess heat from containment to the atmosphere by integrating low-temperature heat pipes into the containment building (to ensure long-term cooling following a station blackout), and passively cooling spent fuel bays. (author)

Detergent inhibited, heat labile nucleoside triphosphatase in cores of avian myeloblastosis virus

DEFF Research Database (Denmark)

Jensen, Kaj Frank

1978-01-01

Endogenous DNA synthesis was studied in isolated core particles of avian myeloblastosis virus. It was found that cores contained an enzymatic activity which rapidly converted the added nucleoside triphosphates to diphosphates (but not further) at 0 degrees C, thus inhibiting DNA synthesis...

Wu-Tou Decoction Inhibits Chronic Inflammatory Pain in Mice: Participation of TRPV1 and TRPA1 Ion Channels

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Chao Wang

2015-01-01

Full Text Available Wu-tou decoction (WTD is a classic traditional Chinese medicine formula and has been used effectively to treat joint diseases clinically. Previous reports indicated that WTD possesses anti-inflammatory activity; however, its actions on pain have not been clarified. Here, we investigated the antinociceptive activity of WTD in CFA-induced mice, and its possible mechanism of the action associated with transient receptor potential (TRP ion channels was also explored. Our results showed that 1.58, 3.15, and 6.30 g/kg WTD significantly attenuated mechanical, cold, and heat hypersensitivities. Moreover, WTD effectively inhibited spontaneous nociceptive responses to intraplantar injections of capsaicin and cinnamaldehyde, respectively. WTD also effectively suppressed jumping and wet-dog-shake behaviors to intraperitoneal injection of icilin. Additionally, WTD significantly reduced protein expression of TRPV1 and TRPA1 in dorsal root ganglia and skins of injured paw. Collectively, our data demonstrate firstly that WTD exerts antinociceptive activity in inflammatory conditions by attenuating mechanical, cold, and heat hypersensitivities. This antinociceptive effect may result in part from inhibiting the activities of TRPV1, TRPA1, and TRPM8, and the suppression of TRPV1 and TRPA1 protein by WTD was also highly effective. These findings suggest that WTD might be an attractive and suitable therapeutic agent for the management of chronic inflammatory pain.

TRPV3 and TRPV4 ion channels are not major contributors to mouse heat sensation

Directory of Open Access Journals (Sweden)

Wang Juan

2011-05-01

Full Text Available Abstract Background The discovery of heat-sensitive Transient Receptor Potential Vanilloid (TRPV ion channels provided a potential molecular explanation for the perception of innocuous and noxious heat stimuli. TRPV1 has a significant role in acute heat nociception and inflammatory heat hyperalgesia. Yet, substantial innocuous and noxious heat sensitivity remains in TRPV1 knockout animals. Here we investigated the role of two related channels, TRPV3 and TRPV4, in these capacities. We studied TRPV3 knockout animals on both C57BL6 and 129S6 backgrounds, as well as animals deficient in both TRPV3 and TRPV4 on a C57BL6 background. Additionally, we assessed the contributions of TRPV3 and TRPV4 to acute heat nociception and inflammatory heat hyperalgesia during inhibition of TRPV1. Results TRPV3 knockout mice on the C57BL6 background exhibited no obvious alterations in thermal preference behavior. On the 129S6 background, absence of TRPV3 resulted in a more restrictive range of occupancy centered around cooler floor temperatures. TRPV3 knockout mice showed no deficits in acute heat nociception on either background. Mice deficient in both TRPV3 and TRPV4 on a C57BL6 background showed thermal preference behavior similar to wild-type controls on the thermal gradient, and little or no change in acute heat nociception or inflammatory heat hyperalgesia. Masking of TRPV1 by the TRPV1 antagonist JNJ-17203212 did not reveal differences between C57BL6 animals deficient in TRPV3 and TRPV4, compared to their wild-type counterparts. Conclusions Our results support the notion that TRPV3 and TRPV4 likely make limited and strain-dependent contributions to innocuous warm temperature perception or noxious heat sensation, even when TRPV1 is masked. These findings imply the existence of other significant mechanisms for heat perception.

Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

OpenAIRE

Baars, Destiny L.; Takle, Kendra A.; Heier, Jonathon; Pelegri, Francisco

2016-01-01

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole...

Corrosion Inhibition of Aluminium by Treculia Africana Leaves Extract in Acid Medium

OpenAIRE

Ejikeme, P.M.; Umana, S.G.; Onukwuli, O.D.

2012-01-01

The inhibitive effect of Treculia Africana leaves extract (TALE) in the corrosion of aluminium in HCl solution was studied using weight loss and thermometric methods at 30-60 °C. The results showed that TALE acted as a corrosion inhibitor of aluminium in HCl. Inhibition efficiency increased with increase in TALE concentration, but decreased with increase in temperature. TALE interaction with the metal surface was found to obey Freundlich and El-Awady adsorption isotherms. The obtained heats o...

Mesothelioma Cells Escape Heat Stress by Upregulating Hsp40/Hsp70 Expression via Mitogen-Activated Protein Kinases

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Michael Roth

2009-01-01

Full Text Available Therapy with hyperthermal chemotherapy in pleural diffuse malignant mesothelioma had limited benefits for patients. Here we investigated the effect of heat stress on heat shock proteins (HSP, which rescue tumour cells from apoptosis. In human mesothelioma and mesothelial cells heat stress (39–42°C induced the phosphorylation of two mitogen activated kinases (MAPK Erk1/2 and p38, and increased Hsp40, and Hsp70 expression. Mesothelioma cells expressed more Hsp40 and were less sensitive to heat stress compared to mesothelial cells. Inhibition of Erk1/2 MAPK by PD98059 or by Erk1 siRNA down-regulated heat stress-induced Hsp40 and Hsp70 expression and reduced mesothelioma cell survival. Inhibition of p38MAPK by SB203580 or siRNA reduced Hsp40, but not Hsp70, expression and also increased mesothelioma cell death. Thus hyperthermia combined with suppression of p38 MAPK or Hsp40 may represent a novel approach to improve mesothelioma therapy.

Significance of heat-moisture treatment conditions on the pasting and gelling behaviour of various starch-rich cereal and pseudocereal flours.

Science.gov (United States)

Collar, Concha

2017-10-01

The impact of heat-moisture treatment processing conditions (15%, 25%, and 35% moisture content; 1, 3, and 5 h heating time at 120 ℃) on the viscosity pasting and gelling profiles of different grain flours matrices (barley, buckwheat, sorghum, high β-glucan barley, and wheat) was investigated by applying successive cooking and cooling cycles to rapid visco analyser canisters with highly hydrated samples (3.5:25, w:w). At a milder heat-moisture treatment conditions (15% moisture content, 1 h heating time), except for sorghum, heat-moisture treatment flours reached much higher viscosity values during earlier pasting and subsequent gelling than the corresponding native counterparts. Besides heat-moisture treatment wheat flour, the described behaviour found also for non-wheat-treated flours has not been previously reported in the literature. An increased hydrophobicity of prolamins and glutelins in low moisture-short heating time heat-moisture treatment of non-wheat flours with high protein content (12.92%-19.95%) could explain the enhanced viscosity profile observed.

Laticifer proteins from Plumeria pudica inhibit the inflammatory and nociceptive responses by decreasing the action of inflammatory mediators and pro-inflammatory cytokines

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Heliana B. Fernandes

Full Text Available AbstractSome publications have described the pharmacological properties of latices proteins. Thus, in the present study proteins from Plumeria pudica Jacq., Apocynaceae, latex were evaluated for anti-inflammatory and antinociceptive activities. Obtained data showed that an intraperitoneal administration of different doses of latex was able to reduce the paw edema induced by carrageenan in a dose-dependent manner (better dose 40 mg/kg; 72.7% inhibition at 3rd and 78.7% at 4th hour and the edema induced by dextran (40 mg/kg; 51.5% inhibition at 30 min and 93.0% at 1st hour. Inhibition of edema induced by carrageenan was accompanied by a reduction of myeloperoxidase activity. Pre-treating animals with latex (40 mg/kg also inhibited the paw edema induced by histamine, serotonin, bradykinin, prostaglandin E2, compound 48/80. Additionally, the latex (40 mg/kg reduced the leukocyte peritoneal migration induced by carrageenan and this event was followed by reduction of IL-1β and TNF-α in peritoneal fluid. The latex-treatment (40 mg/kg reduced the animal abdominal constrictions induced by acetic acid and the first phase on paw licking model induced by formalin. When latex was treated with heat (at 100 °C for 30 min, anti-edematogenic and myeloperoxidase activities were significantly reduced, indicating the involvement of heat-sensitive proteins on anti-inflammatory effect. Our results evidence that latex fluids are a source of proteins with pharmacological properties.

Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis II. Quantification of inhibition and suitability of membrane reactors

DEFF Research Database (Denmark)

Andric, Pavle; Meyer, Anne S.; Jensen, Peter Arendt

2010-01-01

conversion are required for alleviation of glucose product inhibition. Supported by numerous calculations this review assesses the quantitative aspects of glucose product inhibition on enzyme-catalyzed cellulose degradation rates. The significance of glucose product inhibition on dimensioning of different......Product inhibition of cellulolytic enzymes affects the efficiency of the biocatalytic conversion of lignocellulosic biomass to ethanol and other valuable products. New strategies that focus on reactor designs encompassing product removal, notably glucose removal, during enzymatic cellulose...... reactor features, including system set-up, dilution rate, glucose output profile, and the problem of cellobiose are examined to illustrate the quantitative significance of the glucose product inhibition and the total glucose concentration on the cellulolytic conversion rate. Comprehensive overviews...

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.

Modelling of Thermal Behavior of Borehole Heat Exchangers of Geothermal Heat Pump Heating Systems

Directory of Open Access Journals (Sweden)

Gornov V.F.

2016-01-01

Full Text Available This article reports results of comparing the accuracy of the software package “INSOLAR.GSHP.12”, modeling non-steady thermal behavior of geothermal heat pump heating systems (GHCS and of the similar model “conventional” using finite difference methods for solving spatial non-steady problems of heat conductivity. The software package is based on the method of formulating mathematical models of thermal behavior of ground low-grade heat collection systems developed by INSOLAR group of companies. Equations of mathematical model of spatial non-steady thermal behavior of ground mass of low-grade heat collection system obtained by the developed method have been solved analytically that significantly reduced computing time spent by the software complex “INSOLAR.GSHP.12” for calculations. The method allows to turn aside difficulties associated with information uncertainty of mathematical models of the ground thermal behavior and approximation of external factors affecting the ground. Use of experimentally obtained information about the ground natural thermal behavior in the software package allows to partially take into account the whole complex of factors (such as availability of groundwater, their velocity and thermal behavior, structure and arrangement of ground layers, the Earth’s thermal background, precipitation, phase transformations of moisture in the pore space, and more, significantly influencing the formation of thermal behavior of the ground mass of a low-grade geothermal heat collection system. Numerical experiments presented in the article confirmed the high convergence of the results obtained through the software package “INSOLAR.GSHP.12” with solutions obtained by conventional finite-difference methods.

Comparison of LCA results of low temperature heat plant using electric heat pump, absorption heat pump and gas-fired boiler

International Nuclear Information System (INIS)

Nitkiewicz, Anna; Sekret, Robert

2014-01-01

Highlights: • Usage of geothermal heat pump can bring environmental benefits. • The lowest environmental impact for whole life cycle is obtained for absorption heat pump. • The value of heat pump COP has a significant influence on environmental impact. • In case of coal based power generation the damage to human health is significant. - Abstract: This study compares the life cycle impacts of three heating plant systems which differ in their source of energy and the type of system. The following heating systems are considered: electric water-water heat pump, absorption water-water heat pump and natural gas fired boiler. The heat source for heat pump systems is low temperature geothermal source with temperature below 20 °C and spontaneous outflow 24 m 3 /h. It is assumed that the heat pumps and boiler are working in monovalent system. The analysis was carried out for heat networks temperature characteristic at 50/40 °C which is changing with outdoor temperature during heating season. The environmental life cycle impact is evaluated within life cycle assessment methodological framework. The method used for life cycle assessment is eco-indicator ‘99. The functional unit is defined as heating plant system with given amount of heat to be delivered to meet local heat demand in assumed average season. The data describing heating plant system is derived from literature and energy analysis of these systems. The data describing the preceding life cycle phases: extraction of raw materials and fuels, production of heating devices and their transportation is taken from Ecoinvent 2.0 life cycle inventory database. The results were analyzed on three levels of indicators: single score indicator, damage category indicators and impact category indicator. The indicators were calculated for characterization, normalization and weighting phases as well. SimaPro 7.3.2 is the software used to model the systems’ life cycle. The study shows that heating plants using a low

The response of leaves to heat stress in tomato plants with source-sink modulated by growth regulators

Directory of Open Access Journals (Sweden)

Zofia Starck

2014-01-01

Full Text Available The response to heat stress was investigated in heat-sensitive, Roma V. F. and heat-tolerant, Robin, cultivars whose fruit growth was stimulated by NOA + GA3 , or NOA + GA3 + zeatin. The treated plants were compared with untreated control plant. In each of these series half of the plants were subjected to one or three cycles of heat stress. A single cycle of 38°/25°C day and night did not significantly affect either the respiration rate or chlorophyll content. In PGR-untreated intact cv. Roma, heat stress inhibited starch formation during the day and strongly depressed night export from the blades. High temperature depressed the night transport less in plants having a higher sink demand of fruits in plant treated with PGR. In this case the amount of substances available for export was much higher and both sugars and starch were more intensively remobilized at night. In intact Robin plants, PGR and heat stress much less affected sugar and starch content. High temperature diminished noctural starch remobilization only in the NOA + GA3 series. Leaf disc growth was evaluated as a measure of response to heat stress after elimination of the direct effect of fruit demands. One cycle of high temperature did not negatively affect the growth of leaf discs; it even caused thermal low growth activation in both cultivars. Three cycles of heat stress depressed leaf disc growth after short-term stimulation, especially in Roma plants. Immediately after 3-day heat stress, there was no response of discs to GA3 or zeatin added to the solution on which the discs were floated. Leaf disc growth of Robin control and NOA + GA3 series was very similar in plants from optimal temperature conditions. High temperature inhibited only disc growth of the NOA + GA3 series owing to depression of starch break-down, diminishing the pool of sugars. In contrast, leaf discs of Roma cv. excided from NOA + GA3 treated plants from the optimal temperature series, grew more intensively

Radiative Heating in MSL Entry: Comparison of Flight Heating Discrepancy to Ground Test and Predictive Models

Science.gov (United States)

Cruden, Brett A.; Brandis, Aaron M.; White, Todd R.; Mahzari, Milad; Bose, Deepak

2014-01-01

During the recent entry of the Mars Science Laboratory (MSL), the heat shield was equipped with thermocouple stacks to measure in-depth heating of the thermal protection system (TPS). When only convective heating was considered, the derived heat flux from gauges in the stagnation region was found to be underpredicted by as much as 17 W/sq cm, which is significant compared to the peak heating of 32 W/sq cm. In order to quantify the contribution of radiative heating phenomena to the discrepancy, ground tests and predictive simulations that replicated the MSL entry trajectory were performed. An analysis is carried through to assess the quality of the radiation model and the impact to stagnation line heating. The impact is shown to be significant, but does not fully explain the heating discrepancy.

Irradiation and heating effects in topaz crystals from Minas Cerais, Brazil

International Nuclear Information System (INIS)

Albuquerque, A.R.P.L.; Isotani, S.

1988-01-01

The origin of the blue color induced by gamma irradiation in topaz crystals from the region around Governador Valadares, Minas Gerais, was examined through chemical analyses and heat treatments before irradiation. No correlation between impurities and the induced blue color was found. Heat treatments above 300 0 C before irradiation inhibit the formation of color. The conclusion is drawn that irradiation induced color is probably due to the presence of lattice defects. (author)

Heat transfer in intermediate heat exchanger under low flow rate conditions

International Nuclear Information System (INIS)

Mochizuki, H.

2008-01-01

The present paper describes the heat transfer in intermediate heat exchangers (IHXs) of liquid metal cooled fast reactors when flow rate is low such as a natural circulation condition. Although empirical correlations of heat transfer coefficients for IHX were derived using test data at the fast reactor 'Monju' and 'Joyo' and also at the 50 MW steam generator facility, the heat transfer coefficient was very low compared to the well known correlation for liquid metals proposed by Seban-Shimazaki. The heat conduction in IHX was discussed as a possible cause of the low Nusselt number. As a result, the heat conduction is not significant under the natural circulation condition, and the heat conduction term in the energy equation can be neglected in the one-dimensional plant dynamics calculation. (authors)

Inhibition of CRM1-mediated nuclear export of influenza A nucleoprotein and nuclear export protein as a novel target for antiviral drug development

Energy Technology Data Exchange (ETDEWEB)

Chutiwitoonchai, Nopporn; Mano, Takafumi; Kakisaka, Michinori; Sato, Hirotaka [Viral Infectious Disease Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kondoh, Yasumitsu; Osada, Hiroyuki [Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kotani, Osamu; Yokoyama, Masaru; Sato, Hironori [Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011 (Japan); Aida, Yoko, E-mail: aida@riken.jp [Viral Infectious Disease Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2017-07-15

An anti-influenza compound, DP2392-E10 based on inhibition of the nuclear export function of the viral nucleoprotein-nuclear export signal 3 (NP-NES3) domain was successfully identified by our previous high-throughput screening system. Here, we demonstrated that DP2392-E10 exerts its antiviral effect by inhibiting replication of a broad range of influenza A subtypes. In regard to the molecular mechanism, we revealed that DP2392-E10 inhibits nuclear export of both viral NP and nuclear export protein (NEP). More specifically, in vitro pull-down assays revealed that DP2392-E10 directly binds cellular CRM1, which mediates nuclear export of NP and NEP. In silico docking suggested that DP2392-E10 binds at a region close to the HEAT9 and HEAT10 domains of CRM1. Together, these results indicate that the CRM1-mediated nuclear export function of influenza virus represents a new potential target for antiviral drug development, and also provide a core structure for a novel class of inhibitors that target this function. - Highlights: •DP2392-E10 inhibits replication of a broad range of influenza A subtypes. •DP2392-E10 inhibits nuclear exports of NP and NEP via their NP-NES3 and NEP-NES2 domains, respectively. •DP2392-E10 is predicted to directly bind CRM1 in the region near the HEAT9 and HEAT10 repeats.

Inhibition of CRM1-mediated nuclear export of influenza A nucleoprotein and nuclear export protein as a novel target for antiviral drug development

International Nuclear Information System (INIS)

Chutiwitoonchai, Nopporn; Mano, Takafumi; Kakisaka, Michinori; Sato, Hirotaka; Kondoh, Yasumitsu; Osada, Hiroyuki; Kotani, Osamu; Yokoyama, Masaru; Sato, Hironori; Aida, Yoko

2017-01-01

An anti-influenza compound, DP2392-E10 based on inhibition of the nuclear export function of the viral nucleoprotein-nuclear export signal 3 (NP-NES3) domain was successfully identified by our previous high-throughput screening system. Here, we demonstrated that DP2392-E10 exerts its antiviral effect by inhibiting replication of a broad range of influenza A subtypes. In regard to the molecular mechanism, we revealed that DP2392-E10 inhibits nuclear export of both viral NP and nuclear export protein (NEP). More specifically, in vitro pull-down assays revealed that DP2392-E10 directly binds cellular CRM1, which mediates nuclear export of NP and NEP. In silico docking suggested that DP2392-E10 binds at a region close to the HEAT9 and HEAT10 domains of CRM1. Together, these results indicate that the CRM1-mediated nuclear export function of influenza virus represents a new potential target for antiviral drug development, and also provide a core structure for a novel class of inhibitors that target this function. - Highlights: •DP2392-E10 inhibits replication of a broad range of influenza A subtypes. •DP2392-E10 inhibits nuclear exports of NP and NEP via their NP-NES3 and NEP-NES2 domains, respectively. •DP2392-E10 is predicted to directly bind CRM1 in the region near the HEAT9 and HEAT10 repeats.

Dry Heat Treatment Reduces the Occurrence of Cladosporium cucumerinum, Ascochyta citrullina, and Colletotrichum orbiculare on the Surface and Interior of Cucumber Seeds

Directory of Open Access Journals (Sweden)

Yanxia Shi

2016-01-01

Full Text Available Dry heat treatment has been identified as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber (Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight, and Colletotrichum orbiculare that induces anthracnose could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significantly reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.

Heat Roadmap Europe

DEFF Research Database (Denmark)

Connolly, David

2017-01-01

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

Application of intensified heat transfer for the retrofit of heat exchanger network

International Nuclear Information System (INIS)

Wang, Yufei; Pan, Ming; Bulatov, Igor; Smith, Robin; Kim, Jin-Kuk

2012-01-01

Highlights: → Novel design approach for the retrofit of HEN based on intensified heat transfer. → Development of a mathematical model to evaluate shell-and-tube heat exchanger performances. → Identification of the most appropriate heat exchangers requiring heat transfer enhancements in the heat exchanger network. -- Abstract: A number of design methods have been proposed for the retrofit of heat exchanger networks (HEN) during the last three decades. Although considerable potential for energy savings can be identified from conventional retrofit approaches, the proposed solutions have rarely been adopted in practice, due to significant topology modifications required and resulting engineering complexities during implementation. The intensification of heat transfer for conventional shell-and-tube heat exchangers can eliminate the difficulties of implementing retrofit in HEN which are commonly restricted by topology, safety and maintenance constraints, and includes high capital costs for replacing equipment and pipelines. This paper presents a novel design approach to solve HEN retrofit problems based on heat transfer enhancement. A mathematical model has been developed to evaluate shell-and-tube heat exchanger performances, with which heat-transfer coefficients and pressure drops for both fluids in tube and shell sides are obtained. The developed models have been compared with the Bell-Delaware, simplified Tinker and Wills-Johnston methods and tested with the HTRI (registered) and HEXTRAN (registered) software packages. This demonstrates that the new model is much simpler but can give reliable results in most cases. For the debottlenecking of HEN, four heuristic rules are proposed to identify the most appropriate heat exchangers requiring heat transfer enhancements in the HEN. The application of this new design approach allows a significant improvement in energy recovery without fundamental structural modifications to the network.

Profitability of heating entrepreneurship from the viewpoint of heating energy buyer, heating energy seller and energy wood seller

Energy Technology Data Exchange (ETDEWEB)

Sauvula-Seppaelae, T.; Ulander, E. (Seinaejoki Univ. of Applied Sciences, Ahtari (Finland), School of Agriculture and Forestry), e-mail: tiina.sauvula-seppala@seamk.fi, e-mail: essi.ulander@seamk.fi

2010-07-01

The focus of this research was to study the profitability of heating entrepreneurships from the viewpoint of heating energy buyer, seller as well as energy wood seller. The average costs of heat production were Eur 44,8 / MWh and incomes Eur 43,4 /MWh. Energy wood purchase, comminution and long distance transportation formed slightly over a half of the heat production costs. Average net income in the group of the largest heating plants (>1000 kW) was Eur 29000 per year and in the group of the smallest (<200 kW) average net income was slightly over Eur 4000 per year. The net income from selling heat represents only a part of the income a heating entrepreneur receives from heat production. Other, significant parts are formed by income from selling energy wood to the plant as well as compensation for supervision and maintenance of the plant. The average net income of a forest owner from selling energy wood to heating entrepreneurs was Eur 18 / m3. Without state subsidies the net income would have been Eur 4 / m3. The price of the heating energy sold by heating entrepreneurs was very competitive. In 2006 it was Eur 30 / MWh cheaper than oil heat, Eur 34 / MWh cheaper than electric heat and Eur 3 / MWh cheaper than district heating. (orig.)

The interactive association between heat shock factor 1 and heat shock proteins in primary myocardial cells subjected to heat stress.

Science.gov (United States)

Tang, Shu; Chen, Hongbo; Cheng, Yanfen; Nasir, Mohammad Abdel; Kemper, Nicole; Bao, Endong

2016-01-01

Heat shock factor 1 (HSF1) is a heat shock transcription factor that rapidly induces heat shock gene transcription following thermal stress. In this study, we subjected primary neonatal rat myocardial cells to heat stress in vitro to create a model system for investigating the trends in expression and association between various heat shock proteins (HSPs) and HSF1 under adverse environmental conditions. After the cells were subjected to heat stress at 42˚C for different periods of time, HSP and HSF1 mRNA and protein levels were detected by qPCR and western blot analysis in the heat-stressed cells. The HSF1 expression levels significantly increased in the cells following 120 min of exposure to heat stess compared to the levels observed at the beginning of heat stress exposure. HSP90 followed a similar trend in expression to HSF1, whereas HSP70 followed an opposite trend. However, no significant changes were observed in the crystallin, alpha B (CRYAB, also known as HSP beta-5) expression levels during the 480‑min period of exposure to heat stress. The interaction between the HSPs and HSF1 was analyzed by STRING 9.1, and it was found that HSF1 interacted with HSP90 and HSP70, and that it did not play a role in regulating CRYAB expression. Based on our findings, HSP70 may suppress HSF1 in rat myocardial cells under conditions of heat stress. Furthermore, our data demonstrate that HSF1 is not the key factor for all HSPs, and this was particularly the case for CRYAB.

An improved model of heat-induced hyperalgesia--repetitive phasic heat pain causing primary hyperalgesia to heat and secondary hyperalgesia to pinprick and light touch.

Science.gov (United States)

Jürgens, Tim P; Sawatzki, Alexander; Henrich, Florian; Magerl, Walter; May, Arne

2014-01-01

This study tested a modified experimental model of heat-induced hyperalgesia, which improves the efficacy to induce primary and secondary hyperalgesia and the efficacy-to-safety ratio reducing the risk of tissue damage seen in other heat pain models. Quantitative sensory testing was done in eighteen healthy volunteers before and after repetitive heat pain stimuli (60 stimuli of 48°C for 6 s) to assess the impact of repetitive heat on somatosensory function in conditioned skin (primary hyperalgesia area) and in adjacent skin (secondary hyperalgesia area) as compared to an unconditioned mirror image control site. Additionally, areas of flare and secondary hyperalgesia were mapped, and time course of hyperalgesia determined. After repetitive heat pain conditioning we found significant primary hyperalgesia to heat, and primary and secondary hyperalgesia to pinprick and to light touch (dynamic mechanical allodynia). Acetaminophen (800 mg) reduced pain to heat or pinpricks only marginally by 11% and 8%, respectively (n.s.), and had no effect on heat hyperalgesia. In contrast, the areas of flare (-31%) and in particular of secondary hyperalgesia (-59%) as well as the magnitude of hyperalgesia (-59%) were significantly reduced (all pheat pain induces significant peripheral sensitization (primary hyperalgesia to heat) and central sensitization (punctate hyperalgesia and dynamic mechanical allodynia). These findings are relevant to further studies using this model of experimental heat pain as it combines pronounced peripheral and central sensitization, which makes a convenient model for combined pharmacological testing of analgesia and anti-hyperalgesia mechanisms related to thermal and mechanical input.

An Improved Model of Heat-Induced Hyperalgesia—Repetitive Phasic Heat Pain Causing Primary Hyperalgesia to Heat and Secondary Hyperalgesia to Pinprick and Light Touch

Science.gov (United States)

Henrich, Florian; Magerl, Walter; May, Arne

2014-01-01

This study tested a modified experimental model of heat-induced hyperalgesia, which improves the efficacy to induce primary and secondary hyperalgesia and the efficacy-to-safety ratio reducing the risk of tissue damage seen in other heat pain models. Quantitative sensory testing was done in eighteen healthy volunteers before and after repetitive heat pain stimuli (60 stimuli of 48°C for 6 s) to assess the impact of repetitive heat on somatosensory function in conditioned skin (primary hyperalgesia area) and in adjacent skin (secondary hyperalgesia area) as compared to an unconditioned mirror image control site. Additionally, areas of flare and secondary hyperalgesia were mapped, and time course of hyperalgesia determined. After repetitive heat pain conditioning we found significant primary hyperalgesia to heat, and primary and secondary hyperalgesia to pinprick and to light touch (dynamic mechanical allodynia). Acetaminophen (800 mg) reduced pain to heat or pinpricks only marginally by 11% and 8%, respectively (n.s.), and had no effect on heat hyperalgesia. In contrast, the areas of flare (−31%) and in particular of secondary hyperalgesia (−59%) as well as the magnitude of hyperalgesia (−59%) were significantly reduced (all pheat pain induces significant peripheral sensitization (primary hyperalgesia to heat) and central sensitization (punctate hyperalgesia and dynamic mechanical allodynia). These findings are relevant to further studies using this model of experimental heat pain as it combines pronounced peripheral and central sensitization, which makes a convenient model for combined pharmacological testing of analgesia and anti-hyperalgesia mechanisms related to thermal and mechanical input. PMID:24911787

Flexible use of electricity in heat-only district heating plants

Directory of Open Access Journals (Sweden)

Erik Trømborg

2017-01-01

Full Text Available European energy systems are in a period of significant transition, with the increasing shares of variable renewable energy (VRE and less flexible fossil-based generation units as predominant factors. The supply-side changes are expected to cause large short-term electricity price volatility. More frequent periods of low electricity prices may mean that electric use in flexible heating systems will become more profitable, and such flexible heating systems may, in turn, improve the integration of increasing shares of VRE. The objective of this study is to analyze the likely future of Nordic electricity price levels and variations and how the expected prices might affect the use of electricity and thermal storage in heat-only district heating plants. We apply the North European energy market model Balmorel to provide scenarios for future hourly electricity prices in years with normal, high, and low inflow levels to the hydro power system. The simulation tool energyPRO is subsequently applied to quantify how these electricity price scenarios affect the hourly use of thermal storage and individual boilers in heat-only district heating plants located in Norway. The two studied example plants use wood chips or heat pump as base load representing common technologies for district heating in Norway. The Balmorel results show that annual differences in inflow is still a decisive factor for Norwegian and Nordic electricity prices in year 2030 and that short-term (daily price variability is expected to increase. In the plant-level simulations, we find that tank storage, which is currently installed in only a few district heating plants in Norway, is a profitable flexibility option that will significantly reduce the use of fossil peak load in both biomass and heat-pump-based systems. Installation of an electric boiler in addition to tank storage is profitable in the heat pump system due to the limited capacity of the heat pump. Electricity will hence, to a

Heat loss mechanisms in a measurement of specific heat capacity of graphite

International Nuclear Information System (INIS)

Shipley, D.R.; Duane, S.

1996-01-01

Absorbed dose to graphite in electron beams with nominal energies in the range 3-20 MeV is determined by measuring the temperature rise in the core of a primary standard graphite calorimeter. This temperature rise is related to absorbed dose by a separate measurement of the specific heat capacity of the graphite core. There is, however, a small but significant amount of heat loss from the sample in the determination of specific heat capacity and corrections for these losses are required. This report discusses the sources of heat loss in the measurements and, where possible, provides estimates for the magnitude of these losses. For those mechanisms which are significant, a more realistic model of the measurement system is analysed and corrections for the losses are provided. (UK)

Norwegian households' perception of wood pellet stove compared to air-to-air heat pump and electric heating

International Nuclear Information System (INIS)

Sopha, Bertha Maya; Kloeckner, Christian A.; Skjevrak, Geir; Hertwich, Edgar G.

2010-01-01

In 2003, the high dependency on electric heating combined with the high electricity price prompted a significant number of Norwegian households to consider alternative heating systems. The government introduced economic support for wood pellet heating and heat pumps. In contrast to the fast growing heat pump market, this financial support has not resulted in a widespread adoption of wood pellet heating. This paper studies factors that influence the choice of heating system based on Norwegian households' perceptions. Electric heating, heat pump and wood pellet heating were compared, with a special focus on wood pellet heating. This study was conducted as a questionnaire survey on two independent samples. The first sample consisted of 188 randomly chosen Norwegian households, mainly using electric heating; the second sample consisted of 461 households using wood pellet heating. Our results show that socio-demographic factors, communication among households, the perceived importance of heating system attributes, and the applied decision strategy all influence the Norwegian homeowners. The significance of these factors differs between the two samples and the preferred type of anticipated future heating system. Strategies for possible interventions and policy initiatives are discussed.

Stokes flow heat transfer in an annular, rotating heat exchanger

International Nuclear Information System (INIS)

Saatdjian, E.; Rodrigo, A.J.S.; Mota, J.P.B.

2011-01-01

The heat transfer rate into highly viscous, low thermal-conductivity fluids can be enhanced significantly by chaotic advection in three-dimensional flows dominated by viscous forces. The physical effect of chaotic advection is to render the cross-sectional temperature field uniform, thus increasing both the wall temperature gradient and the heat flux into the fluid. A method of analysis for one such flow-the flow in the eccentric, annular, rotating heat exchanger-and a procedure to determine the best heat transfer conditions, namely the optimal values of the eccentricity ratio and time-periodic rotating protocol, are discussed. It is shown that in continuous flows, such as the one under consideration, there exists an optimum frequency of the rotation protocol for which the heat transfer rate is a maximum. - Highlights: → The eccentric, annular, rotating heat exchanger is studied for periodic Stokes flow. → Counter-rotating the inner tube with a periodic velocity enhances the heat transfer. → The heat-transfer enhancement under such conditions is due to chaotic advection. → For a given axial flow rate there is a frequency that maximizes the heat transfer. → There is also an optimum value of the eccentricity ratio.

A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers.

Science.gov (United States)

de Jong, J A; Wijnant, Y H; de Boer, A

2014-03-01

A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic systems. The model is implementable in existing (quasi-)1D thermoacoustic codes, such as DeltaEC. Examples of generated results show good agreement with literature results. The model allows for arbitrary wave phasing; however, it is shown that the wave phasing does not significantly influence the heat transfer.

Performance of heat engines with non-zero heat capacity

International Nuclear Information System (INIS)

Odes, Ron; Kribus, Abraham

2013-01-01

Highlights: ► Finite heat capacity is a second irreversibility mechanism in addition to thermal resistance. ► Heat capacity introduces thermal transients and reverse heat flow. ► Engine maximum power and efficiency are lower for finite heat capacity. ► Implementing the optimal engine cycle requires active control. - Abstract: The performance of a heat engine is analyzed subject to two types of irreversibility: a non-zero heat capacity, together with the more common finite heat transfer rate between the engine and the external heat reservoirs. The heat capacity represents an engine body that undergoes significant temperature variations during the engine cycle. An option to cut off the heat exchange between the engine and the external surrounding for part of the engine cycle is also explored. A variational approach was taken to find the engine’s internal temperature profile (which defines the internal thermodynamic cycle) that would produce maximum power. The maximum power is shown to be lower than the case of zero heat capacity, due to a loss of heat that is stored in the engine body and then lost, bypassing the thermodynamic cycle. The maximum efficiency and the efficiency at maximum power are also lower than the zero heat capacity case. Similar to the Curzon–Ahlborn analysis, power can be traded for increased efficiency, but for high heat capacity, the range of efficiency that is available for such a trade is diminished. Isolating the engine during part of the cycle reduces maximum power, but the efficiency at maximum power and the maximum efficiency are improved, due to better exploitation of heat stored in the engine body. This might be useful for real engines that are limited by the internal energy change during a single engine cycle or by the operating frequency, leading to a broader power–efficiency curve.

Space Heating Equipment

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin D.

1998-01-01

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

Mask humidity during CPAP: influence of ambient temperature, heated humidification and heated tubing.

Science.gov (United States)

Nilius, Georg; Domanski, Ulrike; Schroeder, Maik; Woehrle, Holger; Graml, Andrea; Franke, Karl-Josef

2018-01-01

Mucosal drying during continuous positive airway pressure (CPAP) therapy is problematic for many patients. This study assessed the influence of ambient relative humidity (rH) and air temperature (T) in winter and summer on mask humidity during CPAP, with and without mask leak, and with or without heated humidification ± heated tubing. CPAP (8 and 12 cmH 2 O) without humidification (no humidity [nH]), with heated humidification controlled by ambient temperature and humidity (heated humidity [HH]) and HH plus heated tubing climate line (CL), with and without leakage, were compared in 18 subjects with OSA during summer and winter. The absolute humidity (aH) and the T inside the mask during CPAP were significantly lower in winter versus summer under all applied conditions. Overall, absolute humidity differences between summer and winter were statistically significant in both HH and CL vs. nH ( p humidification or with standard HH. Clinically-relevant reductions in aH were documented during CPAP given under winter conditions. The addition of heated humidification, using a heated tube to avoid condensation is recommended to increase aH, which could be useful in CPAP users complaining of nose and throat symptoms.

AAV-Mediated Gene Targeting Is Significantly Enhanced by Transient Inhibition of Nonhomologous End Joining or the Proteasome In Vivo

Science.gov (United States)

Paulk, Nicole K.; Loza, Laura Marquez; Finegold, Milton J.

2012-01-01

Abstract Recombinant adeno-associated virus (rAAV) vectors have clear potential for use in gene targeting but low correction efficiencies remain the primary drawback. One approach to enhancing efficiency is a block of undesired repair pathways like nonhomologous end joining (NHEJ) to promote the use of homologous recombination. The natural product vanillin acts as a potent inhibitor of NHEJ by inhibiting DNA-dependent protein kinase (DNA-PK). Using a homology containing rAAV vector, we previously demonstrated in vivo gene repair frequencies of up to 0.1% in a model of liver disease hereditary tyrosinemia type I. To increase targeting frequencies, we administered vanillin in combination with rAAV. Gene targeting frequencies increased up to 10-fold over AAV alone, approaching 1%. Fah−/−Ku70−/− double knockout mice also had increased gene repair frequencies, genetically confirming the beneficial effects of blocking NHEJ. A second strategy, transient proteasomal inhibition, also increased gene-targeting frequencies but was not additive to NHEJ inhibition. This study establishes the benefit of transient NHEJ inhibition with vanillin, or proteasome blockage with bortezomib, for increasing hepatic gene targeting with rAAV. Functional metabolic correction of a clinically relevant disease model was demonstrated and provided evidence for the feasibility of gene targeting as a therapeutic strategy. PMID:22486314

Influence of heat treatment on microstructure and passivity of Cu ...

Indian Academy of Sciences (India)

200 ◦C for 20 h in salt bath and air cooled), B (heating up to 800 ◦C for 20 h and water ... chloride ions on passivity was associated with the formation of copper oxides/hydroxide and ... passive layer inhibits copper redeposition and/or preferen-.

On the role of ion heating in ICRF-heated discharges in Tore Supra

International Nuclear Information System (INIS)

Eriksson, L.G.; Hoang, G.; Bergeaud, V.

2000-09-01

The effect of bulk ion heating in Tore Supra has been investigated by studying discharges with varying concentrations of minority ions during ICRF hydrogen minority heating in Deuterium/ 4 He plasmas. As expected, the level of bulk ion heating is found to increase with the minority concentration. Higher levels of ion heating are shown to be accompanied by two significant effects: an improved energy confinement and a strong influence on the plasma rotation. (author)

Study of the technology of heat pipe on prevention wildfire of coal gangue hill

Science.gov (United States)

Deng, Jun; Li, Bei; Ding, Ximei; Ma, Li

2017-04-01

Self-ignitable coal gangue hill (CGH) is one kind of special combustion system, which has the characteristics of low self-ignite point, large heat storage, and easy reignition. The currently industrial fire extinguishing methods, such as inhibiting tendency of coal self-ignition, loessial overburden, and cement grouting, had unsatisfied effects for dispersing the heat out in time. Correspondingly, the CGH will lead reignition more frequently with the passage of time. The high underground temperature of CGH threatens the process of ecological and vegetation construction. Therefore, the elimination of high temperature is a vital issue to be solved urgently for habitat restoration. To achieve the ultimately ecological management goal of self-ignitable CGH - extinguishing the fire completely and never reignited, it is crucial to break the heat accumulation. Heat-pipe (HP) has a character of high efficient heat transfer capacity for eliminating the continuously high temperature in CGH. An experimental system was designed to test the heat transfer performance of HP for preventing and extinguishing the spontaneous combustion of coal gangue. Based on the heat transfer theory, the resistance network of the coal-HP heat removal system was analyzed for studying the cooling effect of HP. The experimental results show that the HP can accelerate the heat release in coal gangue pile. The coal temperature could be controlled at 59.6 ˚ C with HP in 7 h and the highest cooling value is 39.4 % with HP in 150 h, which can effectively cool the temperatures of high temperature zones. As a powerful heat transfer components, as soon as HPs were inserted into the CGH with a reasonable distance, it can completely play a vital role in inhibiting the coal self-ignition process.

WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING

Directory of Open Access Journals (Sweden)

Y. Baradey

2015-11-01

Full Text Available Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well. KEYWORDS: waste heat recovery; heat pump.

Halide Binding and Inhibition of Laccase Copper Clusters: The Role of Reorganization Energy

DEFF Research Database (Denmark)

Kepp, Kasper Planeta

2015-01-01

Laccase-like proteins are multicopper oxidases involved in several biological and industrial processes. Their application is commonly limited due to inhibition by fluoride and chloride, and as-isolated proteins are often substantially activated by heat, suggesting that multiple redox states can c...

Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

DEFF Research Database (Denmark)

Dannemand, Mark; Furbo, Simon; Perers, Bengt

2017-01-01

. When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity......The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes...

Thermotolerance and responses to short duration heat stress in tropical and temperate species

Science.gov (United States)

Marias, D.; Meinzer, F. C.; Still, C. J.

2017-12-01

Temperature and heat waves are predicted to increase throughout the 21st century in both tropical and temperate regions. Tropical species are vulnerable to heat stress because of the higher radiation load and the narrower distribution of temperatures typically experienced compared to extratropical species. Germinant seedlings are also vulnerable to heat stress because they inhabit the boundary layer close to the soil surface where intense heating occurs. We quantified the effect of leaf age and heat stress duration (45 min, 90 min) on leaf thermotolerance and whole plant physiological responses to heat stress in Coffea arabica (COAR) saplings. We also evaluated leaf thermotolerance and whole plant responses to heat stress of seedlings in two populations each of Pinus ponderosa (PIPO) and Pseudotsuga menziesii (PSME) from contrasting climates. Thermotolerance of detached leaves/needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. After exposure of whole plants to a simulated heat wave in a growth chamber, we monitored FV/FM, photosynthesis (A), stomatal conductance (gs), non-structural carbohydrates (NSCs), and carbon isotope ratios (δ13C). In COAR, thermotolerance and rate of recovery increased with leaf age. Following heat treatment, reductions in A and gs led to reduced intrinsic water use efficiency (iWUE) and increased leaf temperatures. NSC results suggested that starch was converted to sugars for recovery from heat stress and phloem transport was inhibited. Plants failed to flower in both heat stress duration treatments. In PIPO and PSME, heat treatment induced significant reductions in FV/FM and A. NSC results suggested that starch was converted to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites had greater δ13C values than those from wetter sites, consistent with higher iWUE of populations from drier climates. Thermotolerance and heat stress responses appeared to be

Solar heating and hot water system installed at Listerhill, Alabama

Science.gov (United States)

1978-01-01

The Solar system was installed into a new building and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants.

Science.gov (United States)

Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

2016-01-08

Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity.

Inhibition Performance in Children with Math Disabilities

OpenAIRE

Winegar, Kathryn Lileth

2013-01-01

This study examined the inhibition deficit hypothesis in children with math disabilities (MD). Children with and without MD were compared on two inhibition tasks that included the random generation of numbers and letters. The results addressed three hypotheses. Weak support was found for the first hypothesis which stated difficulties related to inhibition are significantly related to math performance. I found partial support for this hypothesis in that inhibition was related to math problem s...

Biologically Synthesized Gold Nanoparticles Ameliorate Cold and Heat Stress-Induced Oxidative Stress in Escherichia coli

Directory of Open Access Journals (Sweden)

Xi-Feng Zhang

2016-06-01

Full Text Available Due to their unique physical, chemical, and optical properties, gold nanoparticles (AuNPs have recently attracted much interest in the field of nanomedicine, especially in the areas of cancer diagnosis and photothermal therapy. Because of the enormous potential of these nanoparticles, various physical, chemical, and biological methods have been adopted for their synthesis. Synthetic antioxidants are dangerous to human health. Thus, the search for effective, nontoxic natural compounds with effective antioxidative properties is essential. Although AuNPs have been studied for use in various biological applications, exploration of AuNPs as antioxidants capable of inhibiting oxidative stress induced by heat and cold stress is still warranted. Therefore, one goal of our study was to produce biocompatible AuNPs using biological methods that are simple, nontoxic, biocompatible, and environmentally friendly. Next, we aimed to assess the antioxidative effect of AuNPs against oxidative stress induced by cold and heat in Escherichia coli, which is a suitable model for stress responses involving AuNPs. The response of aerobically grown E. coli cells to cold and heat stress was found to be similar to the oxidative stress response. Upon exposure to cold and heat stress, the viability and metabolic activity of E. coli was significantly reduced compared to the control. In addition, levels of reactive oxygen species (ROS and malondialdehyde (MDA and leakage of proteins and sugars were significantly elevated, and the levels of lactate dehydrogenase activity (LDH and adenosine triphosphate (ATP significantly lowered compared to in the control. Concomitantly, AuNPs ameliorated cold and heat-induced oxidative stress responses by increasing the expression of antioxidants, including glutathione (GSH, glutathione S-transferase (GST, super oxide dismutase (SOD, and catalase (CAT. These consistent physiology and biochemical data suggest that AuNPs can ameliorate cold and

Low-Cost Gas Heat Pump for Building Space Heating

Energy Technology Data Exchange (ETDEWEB)

Garrabrant, Michael [Stone Mountain Technologies, Inc., Johnson City, TN (United States); Keinath, Christopher [Stone Mountain Technologies, Inc., Johnson City, TN (United States)

2016-10-11

Gas-fired residential space heating in the U.S is predominantly supplied by furnaces and boilers. These technologies have been approaching their thermodynamic limit over the past 30 years and improvements for high efficiency units have approached a point of diminishing return. Electric heat pumps are growing in popularity but their heating performance at low ambient temperatures is poor. The development of a low-cost gas absorption heat pump would offer a significant improvement to current furnaces and boilers, and in heating dominated climate zones when compared to electric heat pumps. Gas absorption heat pumps (GAHP) exceed the traditional limit of thermal efficiency encountered by typical furnaces and boilers, and maintain high levels of performance at low ambient temperatures. The project team designed and demonstrated two low-cost packaged prototype GAHP space heating systems during the course of this investigation. Led by Stone Mountain Technologies Inc. (SMTI), with support from A.O. Smith, and the Gas Technology Institute (GTI), the cross-functional team completed research and development tasks including cycle modeling, 8× scaling of a compact solution pump, combustion system development, breadboard evaluation, fabrication of two packaged prototype units, third party testing of the first prototype, and the evaluation of cost and energy savings compared to high and minimum efficiency gas options. Over the course of the project and with the fabrication of two Alpha prototypes it was shown that this technology met or exceeded most of the stated project targets. At ambient temperatures of 47, 35, 17 and -13°F the prototypes achieved gas based coefficients of performance of 1.50, 1.44, 1.37, and 1.17, respectively. Both units operated with parasitic loads well below the 750 watt target with the second Alpha prototype operating 75-100 watts below the first Alpha prototype. Modulation of the units at 4:1 was achieved with the project goal of 2:1 modulation

No effects of acclimation to heat on immune and hormonal responses to passive heating in healthy volunteers

Science.gov (United States)

Kanikowska, Dominika; Sato, Maki; Sugenoya, Junichi; Iwase, Satoshi; Shimizu, Yuuki; Nishimura, Naoki; Inukai, Yoko

2012-01-01

Heat acclimation results in whole body-adaptations that increase heat tolerance, and might also result in changed immune responses. We hypothesized that, after heat acclimation, tumor necrosis factor alpha, interleukin 6 and the lymphocyte count would be altered. Heat acclimation was induced in 6 healthy men by 100 min of heat exposure for 9 days. Heat exposure consisted of (1) 10 min of immersion up to chest-level in water at 42°C and (2) 90 min of passive heating by a warm blanket to maintain tympanic temperature at 37.5°C. The climatic chamber was maintained at 40°C and a relative humidity of 50%. Blood samples were analyzed before and after heat acclimation for natural killer (NK) cell activity, counts of lymphocytes B and T, before and after heat acclimation for peripheral blood morphology, interleukin 6, tumor necrosis factor alpha, and cortisol. A Japanese version of the profile of mood states questionnaire was also administered before and after acclimation. The concentrations of white blood cells, lymphocytes B and T, cortisol, interleukin 6, tumor necrosis factor alpha and NK cell activity showed no significant differences between pre- and post-acclimation, but there was a significantly lower platelet count after acclimation and, with the profile of mood states questionnaire, there was a significant rise in anger after acclimation. It is concluded that heat acclimation by passive heating does not induce alterations in immune or endocrine responses.

Thermal radiosensitization in heat- and radiation-sensitive mutants of CHO cells

International Nuclear Information System (INIS)

Kampinga, H.H.; Kanon, B.; Konings, A.W.T.; Stackhouse, M.A.; Bedford, J.S.

1993-01-01

In the current study, the extent of hyperthermic radiosensitization in a new γ-radiation-sensitive cell line, irs-20, recently isolated by Stackhouse and Bedford (1991) and a heat-sensitive mutant hs-36 (Harvey and Bedford 1988) was compared with the radiosensitization of their mutual parent CHO 10B12 cell line. The irs-20 and CHO 10B12 cells have comparable heat (43.5 o C) sensitivities, whereas hs-36 and CHO 10B12 show a similar sensitivity to γ- and X-rays. Radiosensitization due to pre-exposure to 43.5 o C heating of plateau phase cultures was found for all three cell lines, even after relatively mild heat treatment killing <20% of cells. Experiments using CHEF electrophoresis confirmed the dsb repair deficiency of the irs-20 cells (Stackhouse and Bedford 1992) and showed that heat inhibited dsb repair in all three cell lines. (Author)

Effect of gibberrelic acid on α-amylase activity in heat stressed mung ...

African Journals Online (AJOL)

reading 7

2012-06-28

Jun 28, 2012 ... Gibberellic acid (GA3) is a plant growth hormone, responsible for growth, stress tolerance and ... inhibition of germination has been overcome (Jacobsen et al., 2002). ..... Effect of fluridone on free sugar level in heat stressed ...

Changes in the timing, length and heating degree days of the heating season in central heating zone of China

Science.gov (United States)

Shen, Xiangjin; Liu, Binhui

2016-01-01

Climate change affects the demand for energy consumption, especially for heating and cooling buildings. Using daily mean temperature (Tmean) data, this study analyzed the spatiotemporal changes of the starting date for heating (HS), ending date for heating (HE), length (HL) and heating degree day (HDD) of the heating season in central heating zone of China. Over China’s central heating zone, regional average HS has become later by 0.97 day per decade and HE has become earlier by 1.49 days per decade during 1960–2011, resulting in a decline of HL (−2.47 days/decade). Regional averaged HDD decreased significantly by 63.22 °C/decade, which implies a decreasing energy demand for heating over the central heating zone of China. Spatially, there are generally larger energy-saving rate in the south, due to low average HDD during the heating season. Over China’s central heating zone, Tmean had a greater effect on HL in warm localities and a greater effect on HDD in cold localities. We project that the sensitivity of HL (HDD) to temperature change will increase (decrease) in a warmer climate. These opposite sensitivities should be considered when we want to predict the effects of climate change on heating energy consumption in China in the future. PMID:27651063

A study on the upward and downward facing pool boiling heat transfer characteristics of graphene-modified surface

International Nuclear Information System (INIS)

Kim, Ji Hoon; Ahn, Ho Seon; Kim, Ji Min

2016-01-01

Recently, graphene, carbon in two dimensions, were highlighted as a good heat transfer materials, according to its high thermal conductivity. Lateral conduction and water absorption into the structure helped graphene films to inhibit the formation of hot spots, which means increasing of critical heat flux (CHF) and boiling heat transfer coefficient (BHTC) performances. In this study, we report a promising increase of CHF and BHTC results with 2D graphene films. Furthermore, we tried to observe bubble behavior via high-speed visualization to investigate a relationship between bubble behavior and pool boiling performances in downward facing boiling. The effect of graphene film coating on the pool boiling performances of upward and downward facing heater surface were examined. 2D- and 3D- graphene film showed good enhancement results on the CHF (by 111% and 60%) and BHTC (by 40% and 20-25%) performances. Bubble behavior change was significant factor on the CHF and BHTC performances in downward facing boiling. The amount of evaporation heat flux was calculated from the velocity, bubble diameter, frequency, orientation angle and superheat that the post-products of the high-speed visualization

An optimisation framework for thermal energy storage integration in a residential heat pump heating system

International Nuclear Information System (INIS)

Renaldi, R.; Kiprakis, A.; Friedrich, D.

2017-01-01

Highlights: • An integrated framework for the optimal design of low carbon heating systems. • Development of a synthetic heat demand model with occupancy profiles. • Linear model of a heat pump with thermal energy storage heating system. • Evaluation of domestic heating system from generally available input parameters. • The lower carbon heating system can be cost competitive with conventional systems. - Abstract: Domestic heating has a large share in the UK total energy consumption and significant contribution to the greenhouse gas emissions since it is mainly fulfilled by fossil fuels. Therefore, decarbonising the heating system is essential and an option to achieve this is by heating system electrification through heat pumps (HP) installation in combination with renewable power generation. A potential increase in performance and flexibility can be achieved by pairing HP with thermal energy storage (TES), which allows the shifting of heat demand to off peak periods or periods with surplus renewable electricity. We present a design and operational optimisation model which is able to assess the performance of HP–TES relative to conventional heating systems. The optimisation is performed on a synthetic heat demand model which requires only the annual heat demand, temperature and occupancy profiles. The results show that the equipment and operational cost of a HP system without TES are significantly higher than for a conventional system. However, the integration of TES and time-of-use tariffs reduce the operational cost of the HP systems and in combination with the Renewable Heating Incentive make the HP systems cost competitive with conventional systems. The presented demand model and optimisation procedure will enable the design of low carbon district heating systems which integrate the heating system with the variable renewable electricity supply.

Heat exchanger performance monitoring guidelines

International Nuclear Information System (INIS)

Stambaugh, N.; Closser, W. Jr.; Mollerus, F.J.

1991-12-01

Fouling can occur in many heat exchanger applications in a way that impedes heat transfer and fluid flow and reduces the heat transfer or performance capability of the heat exchanger. Fouling may be significant for heat exchanger surfaces and flow paths in contact with plant service water. This report presents guidelines for performance monitoring of heat exchangers subject to fouling. Guidelines include selection of heat exchangers to monitor based on system function, safety function and system configuration. Five monitoring methods are discussed: the heat transfer, temperature monitoring, temperature effectiveness, delta P and periodic maintenance methods. Guidelines are included for selecting the appropriate monitoring methods and for implementing the selected methods. The report also includes a bibliography, example calculations, and technical notes applicable to the heat transfer method

Characterizing convective heat transfer using infrared thermography and the heated-thin-foil technique

International Nuclear Information System (INIS)

Stafford, Jason; Walsh, Ed; Egan, Vanessa

2009-01-01

Convective heat transfer, due to axial flow fans impinging air onto a heated flat plate, is investigated with infrared thermography to assess the heated-thin-foil technique commonly used to quantify two-dimensional heat transfer performance. Flow conditions generating complex thermal profiles have been considered in the analysis to account for dominant sources of error in the technique. Uncertainties were obtained in the measured variables and the influences on the resultant heat transfer data are outlined. Correction methods to accurately account for secondary heat transfer mechanisms were developed and results show that as convective heat transfer coefficients and length scales decrease, the importance of accounting for errors increases. Combined with flow patterns that produce large temperature gradients, the influence of heat flow within the foil on the resultant heat transfer becomes significant. Substantial errors in the heat transfer coefficient are apparent by neglecting corrections to the measured data for the cases examined. Methods to account for these errors are presented here, and demonstrated to result in an accurate measurement of the local heat transfer map on the surface

Microwave blanching and drying characteristics of Centella asiatica (L.) urban leaves using tray and heat pump-assisted dehumidified drying.

Science.gov (United States)

Trirattanapikul, W; Phoungchandang, S

2014-12-01

The appropriate stage of maturity of Centella asiatica (L.) Urban leaves was investigated. Mature leaves with large diameter contained high total phenolics and % inhibition. Microwave blanching for 30 s retained the highest total phenolics and the microwave blanching for 30 s and 45 s retained the highest % inhibition. Modified Henderson and Modified Chung-Pfost models showed the best fit to both fresh and blanched leaves for equilibrium moisture content, Xe = f(RHe, T) and equilibrium relative humidity, RHe = f(Xe, T), respectively. The Modified Page model was the most effective model in describing the leaf drying. All drying was in the falling rate period. The drying constant was related to drying air temperature using the Arrhenius model. Effective moisture diffusivities increased with increasing temperature and blanching treatments as well as dehumidification by heat pump-assisted dehumidified dryer. The heat pump-assited dehumidified drying incorporated by the microwave blanching could reduce the drying time at 40 °C by 31.2 % and increase % inhibition by 6.1 %. Quality evaluation by total phenolics, % inhibition and rehydration ratio showed the best quality for C. asiatica leaves pretreated by microwave blanching and dried at 40 °C in heat pump-assisted dehumidified dryer.

Heat transfer direction dependence of heat transfer coefficients in annuli

Science.gov (United States)

Prinsloo, Francois P. A.; Dirker, Jaco; Meyer, Josua P.

2018-04-01

In this experimental study the heat transfer phenomena in concentric annuli in tube-in-tube heat exchangers at different annular Reynolds numbers, annular diameter ratios, and inlet fluid temperatures using water were considered. Turbulent flow with Reynolds numbers ranging from 15,000 to 45,000, based on the average bulk fluid temperature was tested at annular diameter ratios of 0.327, 0.386, 0.409 and 0.483 with hydraulic diameters of 17.00, 22.98, 20.20 and 26.18 mm respectively. Both heated and cooled annuli were investigated by conducting tests at a range of inlet temperatures between 10 °C to 30 °C for heating cases, and 30 °C to 50 °C for cooling cases. Of special interest was the direct measurement of local wall temperatures on the heat transfer surface, which is often difficult to obtain and evasive in data-sets. Continuous verification and re-evaluation of temperatures measurements were performed via in-situ calibration. It is shown that inlet fluid temperature and the heat transfer direction play significant roles on the magnitude of the heat transfer coefficient. A new adjusted Colburn j-factor definition is presented to describe the heating and cooling cases and is used to correlate the 894 test cases considered in this study.

Measurement of Critical Heat Flux Using the Transient Inverse Heat Conduction Method in Spray cooling

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeung Chan [Andong Nat’l Univ., Andong (Korea, Republic of)

2016-10-15

A study on the measurement of critical heat flux using the transient inverse heat conduction method in spray cooling was performed. The inverse heat conduction method estimates the surface heat flux or temperature using a measured interior temperature history. The effects of the measuring time interval and location of temperature measurement on the measurement of critical heat flux were primarily investigated. The following results were obtained. The estimated critical heat flux decreased as the time interval of temperature measurement increased. Meanwhile, the effect of measurement location on critical heat flux was not significant. It was also found, from the experimental results, that the critical superheat increased as the measurement location of thermocouple neared the heat transfer surface.

Measurement of Critical Heat Flux Using the Transient Inverse Heat Conduction Method in Spray cooling

International Nuclear Information System (INIS)

Kim, Yeung Chan

2016-01-01

A study on the measurement of critical heat flux using the transient inverse heat conduction method in spray cooling was performed. The inverse heat conduction method estimates the surface heat flux or temperature using a measured interior temperature history. The effects of the measuring time interval and location of temperature measurement on the measurement of critical heat flux were primarily investigated. The following results were obtained. The estimated critical heat flux decreased as the time interval of temperature measurement increased. Meanwhile, the effect of measurement location on critical heat flux was not significant. It was also found, from the experimental results, that the critical superheat increased as the measurement location of thermocouple neared the heat transfer surface.

Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

Directory of Open Access Journals (Sweden)

Irene Carrillo

2011-01-01

Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

Corrosion inhibition of magnesium heated in wet air, by surface fluoridation

International Nuclear Information System (INIS)

Caillat, R.; Darras, R.; Leclercq, D.

1960-01-01

The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [fr

Numerical study on heat transfer characteristics of thermosyphon heat pipes using nanofluids

International Nuclear Information System (INIS)

Huminic, Gabriela; Huminic, Angel

2013-01-01

Highlights: • Numerical study of nanofluid heat transfer in thermosyphon heat pipes is performed. • Effect of nanoparticle concentration and operating temperature are studied. • Fe 2 O 3 –water nanofluid with 5.3% volume concentration shows the best performance. • Results show the improvement the thermal performances of thermosyphon heat pipe with nanofluids. - Abstract: In this work, a three-dimensional analysis is used to investigate the heat transfer of thermosyphon heat pipe using water and nanofluids as the working fluid. The study focused mainly on the effects of volume concentrations of nanoparticles and the operating temperature on the heat transfer performance of the thermosyphon heat pipe using the nanofluids. The analysis was performed for water and γ-Fe 2 O 3 nanoparticles, three volume concentrations of nanoparticles (0 vol.%, 2 vol.% and 5.3 vol.%) and four operating temperatures (60, 70, 80 and 90 °C). The numerical results show that the volume concentration of nanoparticles had a significant effect in reducing the temperature difference between the evaporator and condenser. Experimental and numerical results show qualitatively that the thermosyphon heat pipe using the nanofluid has better heat transfer characteristics than the thermosyphon heat pipe using water

Contrasting responses of urban and rural surface energy budgets to heat waves explain synergies between urban heat islands and heat waves

International Nuclear Information System (INIS)

Li, Dan; Sun, Ting; Liu, Maofeng; Yang, Long; Wang, Linlin; Gao, Zhiqiu

2015-01-01

Heat waves (HWs) are projected to become more frequent and last longer over most land areas in the late 21st century, which raises serious public health concerns. Urban residents face higher health risks due to synergies between HWs and urban heat islands (UHIs) (i.e., UHIs are higher under HW conditions). However, the responses of urban and rural surface energy budgets to HWs are still largely unknown. This study analyzes observations from two flux towers in Beijing, China and reveals significant differences between the responses of urban and rural (cropland) ecosystems to HWs. It is found that UHIs increase significantly during HWs, especially during the nighttime, implying synergies between HWs and UHIs. Results indicate that the urban site receives more incoming shortwave radiation and longwave radiation due to HWs as compared to the rural site, resulting in a larger radiative energy input into the urban surface energy budget. Changes in turbulent heat fluxes also diverge strongly for the urban site and the rural site: latent heat fluxes increase more significantly at the rural site due to abundant available water, while sensible heat fluxes and possibly heat storage increase more at the urban site. These comparisons suggest that the contrasting responses of urban and rural surface energy budgets to HWs are responsible for the synergies between HWs and UHIs. As a result, urban mitigation and adaption strategies such as the use of green roofs and white roofs are needed in order to mitigate the impact of these synergies. (letter)

Inhibiting prenylation augments chemotherapy efficacy in renal cell carcinoma through dual inhibition on mitochondrial respiration and glycolysis.

Science.gov (United States)

Huang, Jiangrong; Yang, Xiaoyu; Peng, Xiaochun; Huang, Wei

2017-11-18

Prenylation is a posttranslational lipid modification required for the proper functions of a number of proteins involved in cell regulation. Here, we show that prenylation inhibition is important for renal cell carcinoma (RCC) growth, survival and response to chemotherapy, and its underlying mechanism may be contributed to mitochondrial dysfunction. We first demonstrated that a HMG-CoA reductase inhibitor pitavastatin inhibited mevalonate pathway and thereby prenylation in RCC cells. In addition, pitavastatin is effective in inhibiting growth and inducing apoptosis in a panel of RCC cell lines. Combination of pitavastatin and paclitaxel is significantly more effective than pitavastatin or paclitaxel alone as shown by both in vitro cell culture system and in vivo RCC xenograft model. Importantly, pitavastatin treatment inhibits mitochondrial respiration via suppressing mitochondrial complex I and II enzyme activities. Interestingly, different from mitochondrial inhibitor phenformin that inhibits mitochondrial respiration but activates glycolytic rate in RCC cells, pitavastatin significantly decreases glycolytic rate. The dual inhibitory action of pitavastatin on mitochondrial respiration and glycolysis results in remarkable energy depletion and oxidative stress in RCC cells. In addition, inhibition of prenylation by depleting Isoprenylcysteine carboxylmethyltransferase (Icmt) also mimics the inhibitory effects of pitavastatin in RCC cells. Our work demonstrates the previously unappreciated association between prenylation inhibition and energy metabolism in RCC, which can be therapeutically exploited, likely in tumors that largely rely on energy metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

Inhibition of growth of Trichophyton tonsurans by Lactobacillus reuteri.

Science.gov (United States)

Guo, J; Mauch, A; Galle, S; Murphy, P; Arendt, E K; Coffey, A

2011-08-01

The aims of this study were to identify antifungal lactic acid bacteria (LAB) and characterize their activity against the dermatophyte Trichophyton tonsurans. A total of 165 different LAB were isolated and initially screened for anti-Penicillium expansum activity. Five strains, which exhibited strong inhibitory activity, were then tested against the dermatophyte T. tonsurans DSM12285, where they also caused inhibition as observed by large fungal clearing on agar surface. The strongest inhibition was seen with Lactobacillus reuteri R2. When freeze-dried cell-free supernatant powder from this strain was incorporated in culture medium at concentrations >1%, growth of fungal colony was inhibited. Conidia germination was also inhibited under these conditions as determined by microscopy. The anti-T. tonsurans activity of Lact. reuteri R2 was not affected neither by heat treatment nor by proteolytic treatment using pronase E and proteinase K, indicating that the responsible agent(s) were nonproteinaceous in nature. Lactobacillus reuteri R2 was identified as having strong inhibitory activity against the dermatophyte T. tonsurans DSMZ12285. LAB are naturally associated with many foods and are well recognized for their biopreservative properties. The use of these and/or their products may well provide alternative safe approaches for the inhibition of dermatophytic fungi. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Effect of heating system using a geothermal heat pump on the production performance and housing environment of broiler chickens.

Science.gov (United States)

Choi, H C; Salim, H M; Akter, N; Na, J C; Kang, H K; Kim, M J; Kim, D W; Bang, H T; Chae, H S; Suh, O S

2012-02-01

A geothermal heat pump (GHP) is a potential heat source for the economic heating of broiler houses with optimum production performance. An investigation was conducted to evaluate the effect of a heating system using a GHP on production performance and housing environment of broiler chickens. A comparative analysis was also performed between the GHP system and a conventional heating system that used diesel for fuel. In total, 34,000 one-day-old straight run broiler chicks were assigned to 2 broiler houses with 5 replicates in each (3,400 birds/replicate pen) for 35 d. Oxygen(,) CO(2), and NH(3) concentrations in the broiler house, energy consumption and cost of heating, and production performance of broilers were evaluated. Results showed that the final BW gain significantly (P heating system did not affect the mortality of chicks during the first 4 wk of the experimental period, but the mortality markedly increased in the conventional broiler house during the last wk of the experiment. Oxygen content in the broiler house during the experimental period was not affected by the heating system, but the CO(2) and NH(3) contents significantly increased (P heating the GHP house was significantly lower (P heating system for broiler chickens.

Selection of Rational Heat Transfer Intensifiers in the Heat Exchanger

Directory of Open Access Journals (Sweden)

S. A. Burtsev

2016-01-01

Full Text Available The paper considers the applicability of different types of heat transfer intensifiers in the heat exchange equipment. A review of the experimental and numerical works devoted to the intensification of the dimpled surface, surfaces with pins and internally ribbed surface were presented and data on the thermal-hydraulic characteristics of these surfaces were given. We obtained variation of thermal-hydraulic efficiency criteria for 4 different objective functions and 15 options for the intensification of heat transfer. This makes it possible to evaluate the advantages of the various heat transfer intensifiers. These equations show influence of thermal and hydraulic characteristics of the heat transfer intensifiers (the values of the relative heat transfer and drag coefficients on the basic parameters of the shell-and-tube heat exchanger: the number and length of the tubes, the volume of the heat exchanger matrix, the coolant velocity in the heat exchanger matrix, coolant flow rate, power to pump coolant (or pressure drop, the amount of heat transferred, as well as the average logarithmic temperature difference. The paper gives an example to compare two promising heat transfer intensifiers in the tubes and shows that choosing the required efficiency criterion to search for optimal heat exchanger geometry is of importance. Analysis is performed to show that a dimpled surface will improve the effectiveness of the heat exchanger despite the relatively small value of the heat transfer intensification, while a significant increase in drag of other heat transfer enhancers negatively affects their thermalhydraulic efficiency. For example, when comparing the target functions of reducing the heat exchanger volume, the data suggest that application of dimpled surfaces in various fields of technology is possible. But there are also certain surfaces that can reduce the parameters of a heat exchanger. It is shown that further work development should be aimed at

Research status and evaluation system of heat source evaluation method for central heating

Science.gov (United States)

Sun, Yutong; Qi, Junfeng; Cao, Yi

2018-02-01

The central heating boiler room is a regional heat source heating center. It is also a kind of the urban environment pollution, it is an important section of building energy efficiency. This article through to the evaluation method of central heating boiler room and overviews of the researches during domestic and overseas, summarized the main influence factors affecting energy consumption of industrial boiler under the condition of stable operation. According to the principle of establishing evaluation index system. We can find that is great significance in energy saving and environmental protection for the content of the evaluation index system of the centralized heating system.

Spasmolytic Mechanism of Aqueous Licorice Extract on Oxytocin-Induced Uterine Contraction through Inhibiting the Phosphorylation of Heat Shock Protein 27

Directory of Open Access Journals (Sweden)

Lu Yang

2017-08-01

Full Text Available Licorice derived from the roots and rhizomes of Glycyrrhiza uralensis Fisch. (Fabaceae, is one of the most widely-used traditional herbal medicines in China. It has been reported to possess significant analgesic activity for treating spastic pain. The aim of this study is to investigate the spasmolytic molecular mechanism of licorice on oxytocin-induced uterine contractions and predict the relevant bioactive constituents in the aqueous extract. The aqueous extraction from licorice inhibited the amplitude and frequency of uterine contraction in a concentration-dependent manner. A morphological examination showed that myometrial smooth muscle cells of oxytocin-stimulated group were oval-shaped and arranged irregularly, while those with a single centrally located nucleus of control and licorice-treated groups were fusiform and arranged orderly. The percentage of phosphorylation of HSP27 at Ser-15 residue increased up to 50.33% at 60 min after oxytocin stimulation. Furthermore, this increase was significantly suppressed by licorice treatment at the concentration of 0.2 and 0.4 mg/mL. Colocalization between HSP27 and α-SMA was observed in the myometrial tissues, especially along the actin bundles in the oxytocin-stimulated group. On the contrary, the colocalization was no longer shown after treatment with licorice. Additionally, employing ChemGPS-NP provided support for a preliminary assignment of liquiritigenin and isoliquiritigenin as protein kinase C (PKC inhibitors in addition to liquiritigenin, isoliquiritigenin, liquiritin and isoliquiritin as MAPK-activated protein kinase 2 (MK2 inhibitors. These assigned compounds were docked with corresponding crystal structures of respective proteins with negative and low binding energy, which indicated a high affinity and tight binding capacity for the active site of the kinases. These results suggest that licorice exerts its spasmolytic effect through inhibiting the phosphorylation of HSP27 to alter the

Experimental Investigation of A Heat Pipe-Assisted Latent Heat Thermal Energy Storage System

Science.gov (United States)

Tiari, Saeed; Mahdavi, Mahboobe; Qiu, Songgang

2016-11-01

In the present work, different operation modes of a latent heat thermal energy storage system assisted by a heat pipe network were studied experimentally. Rubitherm RT55 enclosed by a vertical cylindrical container was used as the Phase Change Material (PCM). The embedded heat pipe network consisting of a primary heat pipe and an array of four secondary heat pipes were employed to transfer heat to the PCM. The primary heat pipe transports heat from the heat source to the heat sink. The secondary heat pipes transfer the extra heat from the heat source to PCM during charging process or retrieve thermal energy from PCM during discharging process. The effects of heat transfer fluid (HTF) flow rate and temperature on the thermal performance of the system were investigated for both charging and discharging processes. It was found that the HTF flow rate has a significant effect on the total charging time of the system. Increasing the HTF flow rate results in a remarkable increase in the system input thermal power. The results also showed that the discharging process is hardly affected by the HTF flow rate but HTF temperature plays an important role in both charging and discharging processes. The authors would like to acknowledge the financial supports by Temple University for the project.

Natural convection in nano-fluids: Are the thermophoresis and Brownian motion effects significant in nano-fluid heat transfer enhancement?

International Nuclear Information System (INIS)

Haddad, Zoubida; Abu-Nada, Eiyad; Oztop, Hakan F.; Mataoui, Amina

2012-01-01

Natural convection heat transfer and fluid flow of CuO-Water nano-fluids is studied using the Rayleigh-Benard problem. A two component non-homogenous equilibrium model is used for the nano-fluid that incorporates the effects of Brownian motion and thermophoresis. Variable thermal conductivity and variable viscosity are taken into account in this work. Finite volume method is used to solve governing equations. Results are presented by streamlines, isotherms, nano-particle distribution, local and mean Nusselt numbers and nano-particle profiles at top and bottom side. Comparison of two cases as absence of Brownian and thermophoresis effects and presence of Brownian and thermophoresis effects showed that higher heat transfer is formed with the presence of Brownian and thermophoresis effect. In general, by considering the role of thermophoresis and Brownian motion, an enhancement in heat transfer is observed at any volume fraction of nano-particles. However, the enhancement is more pronounced at low volume fraction of nano-particles and the heat transfer decreases by increasing nano-particle volume fraction. On the other hand, by neglecting the role of thermophoresis and Brownian motion, deterioration in heat transfer is observed and this deterioration elevates by increasing the volume fraction of nano-particles. (authors)

Raw cow’s milk relatively inhibits quorum sensing activity of Cromobacterium violaceum in comparison to raw she-camel’s milk

Directory of Open Access Journals (Sweden)

A.A. Moawad

2011-10-01

Full Text Available Milk from different animal species has variable levels of antimicrobial factors against some of spoilage bacteria. For example, they are significantly present in higher concentration in she-camel’s milk than in cattle or buffalo and they are more heat-resistant than their counterparts in cattle and buffalo. Spoilage bacteria are known to communicate with each other by release of signaling molecules, a phenomenon described as quorum sensing (QS. Some food matrices inhibit these signaling compounds. In this study we screened QS inhibitory activities in raw milk of cattle and camel. Ten samples each of fresh raw cow’s milk and she-camel’s milk from apparently healthy animals were screened using the bacterial model Cromobacterium violaceum. The tested cow’s raw milk samples were able to inhibit the production of QS signalling molecules acyl-homoserine lactones (AHLs produced by C. violaceum. However, she-camel’s milk samples were less effective in inhibiting such AHLs. Thus, one of the factors which influence the inhibitory activity could be derived from variation in milk chemical composition, especially in the percentage of fat which is significantly higher in tested cow’s milk samples (2.22±0.12 than in tested she-camel’s milk samples (1.44±0.35. Natural inhibition of QS signaling by cow’s milk may offer a unique means to control foodborne pathogens and reduce microbial spoilage.

Optimization between heating load and entropy-production rate for endoreversible absorption heat-transformers

International Nuclear Information System (INIS)

Sun Fengrui; Qin Xiaoyong; Chen Lingen; Wu Chih

2005-01-01

For an endoreversible four-heat-reservoir absorption heat-transformer cycle, for which a linear (Newtonian) heat-transfer law applies, an ecological optimization criterion is proposed for the best mode of operation of the cycle. This involves maximizing a function representing the compromise between the heating load and the entropy-production rate. The optimal relation between the ecological criterion and the COP (coefficient of performance), the maximum ecological criterion and the corresponding COP, heating load and entropy production rate, as well as the ecological criterion and entropy-production rate at the maximum heating load are derived using finite-time thermodynamics. Moreover, compared with the heating-load criterion, the effects of the cycle parameters on the ecological performance are studied by numerical examples. These show that achieving the maximum ecological criterion makes the entropy-production rate decrease by 77.0% and the COP increase by 55.4% with only 27.3% heating-load losses compared with the maximum heating-load objective. The results reflect that the ecological criterion has long-term significance for optimal design of absorption heat-transformers

Heat transfer between adsorbate and laser-heated hot electrons

International Nuclear Information System (INIS)

Ueba, H; Persson, B N J

2008-01-01

Strong short laser pulses can give rise to a strong increase in the electronic temperature at metal surfaces. Energy transfer from the hot electrons to adsorbed molecules may result in adsorbate reactions, e.g. desorption or diffusion. We point out the limitations of an often used equation to describe the heat transfer process in terms of a friction coupling. We propose a simple theory for the energy transfer between the adsorbate and hot electrons using a newly introduced heat transfer coefficient, which depends on the adsorbate temperature. We calculate the transient adsorbate temperature and the reaction yield for a Morse potential as a function of the laser fluency. The results are compared to those obtained using a conventional heat transfer equation with temperature-independent friction. It is found that our equation of energy (heat) transfer gives a significantly lower adsorbate peak temperature, which results in a large modification of the reaction yield. We also consider the heat transfer between different vibrational modes excited by hot electrons. This mode coupling provides indirect heating of the vibrational temperature in addition to the direct heating by hot electrons. The formula of heat transfer through linear mode-mode coupling of two harmonic oscillators is applied to the recent time-resolved study of carbon monoxide and atomic oxygen hopping on an ultrafast laser-heated Pt(111) surface. It is found that the maximum temperature of the frustrated translation mode can reach high temperatures for hopping, even when direct friction coupling to the hot electrons is not strong enough

Resveratrol induces antioxidant and heat shock protein mRNA expression in response to heat stress in black-boned chickens.

Science.gov (United States)

Liu, L L; He, J H; Xie, H B; Yang, Y S; Li, J C; Zou, Y

2014-01-01

This study investigated the effects of dietary resveratrol at 0, 200, 400, or 600 mg/kg of diet on the performance, immune organ growth index, serum parameters, and expression levels of heat shock protein (Hsp) 27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius, thymus, and spleen of 42-d-old female black-boned chickens exposed to heat stress at 37 ± 2°C for 15 d. The results showed that heat stress reduced daily feed intake and BW gain; decreased serum glutathione (GSH), growth hormone, and insulin-like growth factor-1 levels; and inhibited GSH peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities compared with birds subjected to thermo-neutral circumstances. Chickens that were fed diets supplemented with resveratrol exhibited a linear increase in feed intake and BW gain (P stress. In contrast, serum malonaldehyde concentrations were decreased (P stress also reduced (P stress and coincided with an increase in supplemental resveratrol levels. The expression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen were increased (P stress compared with no heat stress. Resveratrol attenuated the heat stress-induced overexpression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen and increased the low expression of Hsp27 and Hsp90 mRNA in thymus upon heat stress. The results suggest that supplemental resveratrol improves growth performance and reduces oxidative stress in heat-stressed black-boned chickens by increasing serum growth hormone concentrations and modulating the expression of heat shock genes in organs of the immune system.

Inhibition of cortiocosteroidogenesis by delta-9-tetrahydrocannabinol.

Science.gov (United States)

Warner, W; Harris, L S; Carchman, R A

1977-12-01

ACTH, cholera toxin, cyclic AMP but not pregnenolone-induced steroidogenesis in Y-1 functional mouse adrenal tumor cells was significantly inhibited by delta-9-tetrahydrocannabinol, cannabidiol, and cannabinol. The inhibition of steroidogenesis could not be correlated with a general depression in cell function or viability. The data suggest that cannabinoids inhibit corticosteroidogenesis at a site between the synthesis of cAMP and of pregnenolone.

A comparison of the heat and mechanical energy of a heat-pump wind turbine system

Energy Technology Data Exchange (ETDEWEB)

Aybek, A.; Arslan, S.; Yildiz, E.; Atik, K. [University of Kahramanmaras (Turkey). Dept. of Agricultural Machinery

2000-07-01

While a variety of applications of wind energy have been studied in Turkey, no significant efforts have been made to utilize heat pumps for heat generation. The use of heat pumps in wind energy systems is worth considering because of the high efficiency of heat production. In this study, a directly coupled wind turbine-heat pump system was designed, constructed, and tested. Measurements determined the mechanical energy of the rotors of the wind turbine and the heat energy generated by the heat pump driven by the rotor shaft. Based on the comparisons between the power generated by the heat pump and the power of the Savonius rotors, it was found that the heat energy gained by the heat pump was four times greater than the mechanical energy obtained from the turbine. It was suggested that heat pumps could be efficiently used in wind energy systems. (Author)

Social vulnerability to heat in Greater Atlanta, USA: spatial pattern of heat, NDVI, socioeconomics and household composition

Science.gov (United States)

Sim, Sunhui

2017-10-01

The purpose of the article is evaluating spatial patterns of social vulnerability to heat in Greater Atlanta in 2015. The social vulnerability to heat is an index of socioeconomic status, household composition, land surface temperature and normalized differential vegetation index (NDVI). Land surface temperature and NDVI were derived from the red, NIR and thermal infrared (TIR) of a Landsat OLI/TIRS images collected on September 14, 2015. The research focus is on the variation of heat vulnerability in Greater Atlanta. The study found that heat vulnerability is highly clustered spatially, resulting in "hot spots" and "cool spots". The results show significant health disparities. The hotspots of social vulnerability to heat occurred in neighborhoods with lower socioeconomic status as measured by low education, low income and more poverty, greater proportion of elderly people and young children. The findings of this study are important for identifying clusters of heat vulnerability and the relationships with social factors. These significant results provide a basis for heat intervention services.

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).

Large heat storage tank for load management nd implementation of ambient heat. District heating networks based on combined heat and power; Grosswaermespeicher zum Lastmanagement und zur Einbindung von Umweltenergie. Auf KWK basierende Fernwaermenetze

Energy Technology Data Exchange (ETDEWEB)

Gross, Sebastian; Rhein, Martin; Ruehling, Karin [Technische Universitaet Dresden (Germany). Inst. fuer Energietechnik

2013-06-15

The district heating based on combined heat and power is a transitional technology on the way to the supply of Germany with renewable energy. In the next years, this transitional technology can only be maintained and expanded when marketability is given. Therefore an appropriate combination has to be found from investment measures. Together with new aspects in the management strategy, these investment measures should significantly improve the marketability. The investment measures also aims to enable a primary energetic, appropriate combination of natural gas-based combined heat and power, renewable energy sources (solar thermal energy, ambient heat) and heat pump technology.

FTR europia gamma heating

International Nuclear Information System (INIS)

Ward, J.T. Jr.

1975-01-01

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

Performance analysis of diesel engine heat pump incorporated with heat recovery

International Nuclear Information System (INIS)

Shah, N.N.; Huang, M.J.; Hewitt, N.J.

2016-01-01

Highlights: • Diesel engine heat pump with heat recovery. • Water-to-water source heat pump based on R134a. • Possibility for different flow temperature for heat distribution system. • Possible retrofit application in off-gas or weak electricity network area. • Potential to diversify use of fossil fuel, primary energy and CO_2 emission savings. - Abstract: This paper presents experimental study of diesel engine heat pump (DEHP) system to find potential as retrofit technology in off-gas or weak electricity network area to replace existing gas/oil/electric heating system in domestic sector. Test set-up of diesel engine driven water-to-water heat pump system was built which included heat recovery arrangement from the engine coolant & exhaust gas. The system was designed to meet typical house heating demand in Northern Ireland. Performance of DEHP was evaluated to meet house-heating demand at different flow temperature (35, 45, 55 & 65 °C), a typical requirement of underfloor space heating, medium/high temperature radiators and domestic hot water. The performance was evaluated against four-evaporator water inlet temperature (0, 5, 10 & 15 °C) and at three different engine speed 1600, 2000 & 2400 rpm. Experiment results were analysed in terms of heating/cooling capacity, heat recovery, total heat output, primary energy ratio (PER), isentropic efficiency, etc. Test results showed that DEHP is able to meet house-heating demand with help of heat recovery with reduced system size. Heat recovery contributed in a range of 22–39% in total heat output. It is possible to achieve high flow temperature in a range of 74 °C with help of heat recovery. Overall system PER varied in a range of 0.93–1.33. Speed increment and flow temperature has significant impact on heat recovery, total heat output and PER. A case scenario with different flow temperature to match house-heating demand has been presented to show working potential with different heat distribution system

Antimicrobial Activity of Nisin and Natamycin Incorporated Sodium Caseinate Extrusion-Blown Films: A Comparative Study with Heat-Pressed/Solution Cast Films.

Science.gov (United States)

Colak, Basak Yilin; Peynichou, Pierre; Galland, Sophie; Oulahal, Nadia; Prochazka, Frédéric; Degraeve, Pascal

2016-05-01

Antimicrobial edible films based on sodium caseinate, glycerol, and 2 food preservatives (nisin or natamycin) were prepared by classical thermomechanical processes. Food preservatives were compounded (at 65 °C for 2.5 min) with sodium caseinate in a twin-screw extruder. Anti-Listeria activity assays revealed a partial inactivation of nisin following compounding. Thermoplastic pellets containing food preservatives were then used to manufacture films either by blown-film extrusion process or by heat-press. After 24 h of incubation on agar plates, the diameters of K. rhizophila growth inhibition zones around nisin-incorporated films prepared by solution casting (control), extrusion blowing or heat pressing at 80 °C for 7 min of nisin-containing pellets were 15.5 ± 0.9, 9.8 ± 0.2, and 8.6 ± 1.0 mm, respectively. Since heat-pressing for 7 min at 80 °C of nisin-incorporated pellets did not further inactivate nisin, this indicates that nisin inactivation during extrusion-blowing was limited. Moreover, the lower diameter of the K. rhizophila growth inhibition zone around films prepared with nisin-containing pellets compared to that observed around films directly prepared by solution casting confirms that nisin inactivation mainly occurred during the compounding step. Natamycin-containing thermoplastic films inhibited Aspergillus niger growth; however, by contrast with nisin-containing films, heat-pressed films had higher inhibition zone diameters than blown films, therefore suggesting a partial inactivation of natamycin during extrusion-blowing. © 2016 Institute of Food Technologists®

Solar heat-pipe wick modeling

Energy Technology Data Exchange (ETDEWEB)

Andraka, C.E.

1999-07-01

Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. In previous experimental work, the author has demonstrated that a heat pipe receiver can significantly improve system performance over a directly-illuminated heater head. The design and operating conditions of a heat pipe receiver differ significantly from typical laboratory heat pipes. New wick structures have been developed to exploit the characteristics of the solar generation system. Typically, these wick structures allow vapor generation within the wick. Conventional heat pipe models do not handle this enhancement, yet it can more than double the performance of the wick. In this study, the author developed a steady-state model of a boiling-enhanced wick for a solar heat pipe receiver. The model is used for design-point calculations and is written in FORTRAN90. Some limited comparisons have been made with actual test data.

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants

Energy Technology Data Exchange (ETDEWEB)

Mathur, Anoop [Terrafore Inc.

2013-08-14

A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during

The role of heat shock protein 90 in the regulation of tumor cell apoptosis.

Science.gov (United States)

Kaigorodova, E V; Ryazantseva, N V; Novitskii, V V; Belkina, M V; Maroshkina, A N

2011-02-01

Programmed death of Jurkat tumor cells was studied under conditions of culturing with 17-AAG selective inhibitor of heat shock protein with a molecular weight of 90 kDa and etoposide. Apoptosis realization was evaluated by fluorescent microscopy with FITC-labeled annexin V and propidium iodide. Activity of caspase-3 was evaluated spectrophotometrically. Inhibition of heat shock protein with a molecular weight of 90 kDa activated the apoptotic program in Jurkat tumor cells and etoposide-induced apoptosis. The heat shock protein with a molecular weight of 90 kDa acted as apoptosis inhibitor in tumor cells.

Increased synaptophysin is involved in inflammation-induced heat hyperalgesia mediated by cyclin-dependent kinase 5 in rats.

Directory of Open Access Journals (Sweden)

Hong-Hai Zhang

Full Text Available Mechanisms associated with cyclin-dependent kinase 5 (Cdk5-mediated heat hyperalgesia induced by inflammation remain undefined. This study was designed to examine whether Cdk5 mediates heat hyperalgesia resulting from peripheral injection of complete Freund's adjuvant (CFA in the spinal dorsal horns of rats by interacting with synaptophysin, a well known membrane protein mediating the endocytosis-exocytosis cycle of synaptic vesicles as a molecular marker associated with presynaptic vesicle membranes. The role of Cdk5 in mediating synaptophysin was examined through the combined use of behavioral approaches, imaging studies, and immunoprecipitation following CFA-induced inflammatory pain. Results showed that Cdk5 colocalized with both synaptophysin and soluble N-ethylmaleimide-sensitive factor (NSF attachment protein receptors (SNAREs consisting of VAMP-2, SNAP-25, and syntaxin 1A in spinal dorsal horn of rats. Increased synaptophysin expression of spinal cord horn neurons post intraplantar injection of CFA coincided with increased duration of heat hyperalgesia lasting from 6 h to 3 d. Intrathecal administration of roscovitine, a Cdk5 specific inhibitor, significantly depressed synaptophysin expression during peak heat hyperalgesia and heat hyperalgesia induced by peripheral injection of CFA. Data presented in this report indicated that calpain activity was transiently upregulated 6 h post CFA-treatment despite previous reports suggesting that calpain was capable of cleaving p35 into p25. Results from previous studies obtained by other laboratories demonstrated that significant changes in p35 expression levels within spinal cord horn neurons were not observed in the CFA-treated inflammatory pain model although significant upregulation of Cdk5 kinase was observed between 2 h to 7 d. Therefore, generation of p25 occurred in a calpain-independent fashion in a CFA-treated inflammatory pain model. Our results demonstrated that increased synaptophysin

Estrogen inhibits chloride secretion caused by cholera and Escherichia coli enterotoxins in female rat distal colon.

OpenAIRE

Alzamora, Rodrigo; O'Mahony, Fiona; Harvey, Brian J

2011-01-01

Excessive Cl(-) secretion is the driving force for secretory diarrhea. 17β-Estradiol has been shown to inhibit Cl(-) secretion in rat distal colon through a nongenomic pathway. We examined whether 17β-estradiol inhibits Cl(-) secretion in an animal model of secretory diarrhea and the downstream effectors involved. The effect of 17β-estradiol on cholera toxin and heat-stable enterotoxin induced Cl(-) secretion in rat colonic mucosal sheets was studied by current-voltage clamping. Selective per...

Forkhead Box M1 Is Regulated by Heat Shock Factor 1 and Promotes Glioma Cells Survival under Heat Shock Stress*

Science.gov (United States)

Dai, Bingbing; Gong, Aihua; Jing, Zhitao; Aldape, Kenneth D.; Kang, Shin-Hyuk; Sawaya, Raymond; Huang, Suyun

2013-01-01

The forkhead box M1 (FoxM1) is a key transcription factor regulating multiple aspects of cell biology. Prior studies have shown that FoxM1 is overexpressed in a variety of human tumors, including brain tumor, and plays a critical role in cancer development and progression. In this study we found that FoxM1 was up-regulated by heat shock factor 1 (HSF1) under heat shock stress condition in multiple cell lines. Knockdown of HSF1 with HSF1 siRNA or inhibition of HSF1 with a HSF1 inhibitor abrogated heat shock-induced expression of FoxM1. Genetic deletion of HSF1 in mouse embryo fibroblast cells also abolished heat shock stress-induced FoxM1 expression. Moreover, we showed that HSF1 directly bound to FoxM1 promoter and increased FoxM1 promoter activity. Furthermore, we demonstrated that FoxM1 was required for the G2-M phase progression through regulating Cdc2, Cdc20, and Cdc25B under a mild heat shock stress but enhanced cell survival under lethal heat shock stress condition. Finally, in human glioblastoma specimens, FoxM1 overexpression correlated with elevated HSF1 expression. Our results indicate that FoxM1 is regulated by HSF1 and is critical for HSF1-mediated heat shock response. We demonstrated a novel mechanism of stress resistance controlled by HSF1 and a new HSF-FoxM1 connection that mediates cellular thermotolerance. PMID:23192351

Inhibition of Staphylococcus aureus in vitro by bacteriocinogenic Lactococcus lactis KTH0-1S isolated from Thai fermented shrimp (Kung-som) and safety evaluation.

Science.gov (United States)

Saelao, Sutanate; Maneerat, Suppasil; Kaewsuwan, Sireewan; Rabesona, Hanitra; Choiset, Yvan; Haertlé, Thomas; Chobert, Jean-Marc

2017-05-01

Lactococcus lactis KTH0-1S isolated from Thai traditional fermented shrimp (Kung-som) is able to produce heat-stable bacteriocin and inhibits food spoilage bacteria and food-borne pathogens. The inhibitory effect of bacteriocin remained intact after treatment with different pHs and after heating, but was sensitive to some proteolytic enzymes. Addition of bacteriocin KTH0-1S to Staphylococcus aureus cultures decreased viable cell counts by 2.8 log CFU/ml, demonstrating a bactericidal mode of action. Furthermore, the growth of S. aureus decreased significantly after 12-h co-cultivation with bacteriocinogenic strain. The molecular mass of bacteriocin KTH0-1S was found to be 3.346 kDa after ammonium sulfate precipitation, reversed phase (C 8 Sep-Pak), cation-exchange chromatography, RP-HPLC on C 8 column and mass spectrometry (MS/MS) analysis. Bacteriocin KTH0-1S was identified as nisin Z using PCR amplification and sequencing. The majority of tested virulence factors were absent, confirming the safety. Evidenced inhibitory effect of this strain, the absence of virulence factors creates the possibility for its application as protective culture to inhibit pathogenic bacteria in the several fermented seafood products.

Design of internally heat-integrated distillation column (HIDiC): Uniform heat transfer area versus uniform heat distribution

Energy Technology Data Exchange (ETDEWEB)

Suphanit, B. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Pracha Utit Rd., Tungkru, Bangkok 10140 (Thailand)

2010-03-15

The internally heat-integrated distillation column (HIDiC) is a complex column configuration which is more energy efficient than the equivalent conventional column or the distillation column with direct vapor recompression scheme (VRC). Exploiting the heat integration between two diabatic sections operating at different pressures of the HIDiC can greatly enhance the energy performance of the system. On the other hand, the design and optimization of HIDiC is more difficult than those of the conventional distillation column or the column with VRC. The former involves many design parameters, and the most critical one is the pressure ratio between both diabatic sections. However, the heat distribution along the diabatic sections is also another significant factor not yet thoroughly investigated. In this work, two typical distribution schemes, i.e. uniform heat transfer area and uniform heat distribution, are studied by applying a novel approach to solve the simulation problem in Aspen Plus 2004.1. The comparison of both distributing schemes is discussed via two widely-used case studies, namely benzene-toluene separation and propylene-propane splitter. (author)

Ion heating at the disruptive instability in the LT-3 Tokamak

International Nuclear Information System (INIS)

Bell, M.G.; Hutchinson, I.H.

1976-01-01

Measurements of the ion temperature and the toroidal current density and electric field during the disruptive instability in LT-3 are presented. Rapid ion heating and strong current inhibition have been observed. Fluctuation measurements suggest that these effects may be attributable to the excitation of ion cyclotron drift waves in the plasma

Heat transfer performance of heat pipe for passive cooling of spent fuel pool

International Nuclear Information System (INIS)

Wang Minglu; Xiong Zhengqin; Gu Hanyang; Ye Cheng; Cheng Xu

2014-01-01

A large-scale loop heat pipe has no electricity driven component and high efficiency of heat transfer. It can be used for the passive cooling of the SFP after SBO to improve the safety performance of nuclear power plants. In this paper, such a large-scale loop heat pipe is studied experimentally. The heat transfer rate, evaporator average heat transfer coefficient operating temperature, operating pressure and ammonia flow rate have been obtained with the water flow ranging from 0.007 m/s to 0.02 m/s outside the evaporator section, heating water temperature in the range of 50 to 90℃, air velocity outside the condensation section ranging from 0.5 to 2.5 m/s. It is found that the heat transfer rate reaches as high as 20.1 kW. Parametric analysis indicates that, the heat transfer rate and ammonia flow rate are influenced significantly by hot water inlet temperature and velocity, while beyond 1.5 m/s, the effect of air velocity outside the condensation section is minor. (authors)

Inhibition of Fusarium solani Infection in Murine Keratocytes by Lactobacillus salivarius ssp. salivarius JCM1231 Culture Filtrate In Vitro.

Science.gov (United States)

Hu, Jianzhang; Chen, Fang; Kan, Tong; Zhuang, Hua; Zhang, Jingjin; Han, Xiaoli

2017-10-01

To explore the inhibitory activity of Lactobacillus salivarius ssp. salivarius JCM1231 (L. salivarius JCM1231) culture filtrate against Fusarium solani (F. solani) and its effects on murine keratocytes (MKs) infected with F. solani. L. salivarius JCM1231 was cultured in an anaerobic incubator for 24 h, and the L. salivarius culture filtrate (LSCF) was prepared .The antifungal activity of L. salivarius JCM1231 against F. solani was determined with a plate overlay assay, agar diffusion assay, and conidial germination inhibition test. The effects of temperature, pH, and proteolytic enzymes on the antifungal activity of LSCF were detected with microtiter plate-well assay and conidial germination inhibition assay. Furthermore, the effects of LSCF on MKs infected with F. solani were detected. Cell activity and apoptosis were measured using methylthiazoletetrazolium assays and flow cytometry analysis, respectively. The levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) cytokines were measured using real-time polymerase chain reactions and enzyme-linked immunosorbent assays (ELISA), and mycotoxin production was detected with high-performance liquid chromatography tandem mass spectrometry. Conidial germination and mycelia growth of F. solani were significantly inhibited by LSCF. The antifungal substances produced by L. salivarius JCM1231 were heat unstable, proteinaceous, and sensitive to proteolytic enzymes and were active within a narrow acidic pH range between 2.0 and 4.0. In the presence of 15 µg/ml of LSCF, cell activity was significantly increased, and cell apoptosis, the level of IL-6 and TNF-α expressions, and mycotoxin (zearalenone and fumonisin B1) productions were decreased significantly in MKs infected with F. solani. L. salivarius JCM1231 culture filtrate can effectively inhibit F. solani growth and protect MKs against F. solani infection.

Heat transfer in heterogeneous propellant combustion systems

International Nuclear Information System (INIS)

Brewster, M.Q.

1992-01-01

This paper reports that heat transfer plays an important role in several critical areas of heterogeneous, solid-propellant combustion systems. These areas include heat feedback to the propellant surface, heat transfer between burning aluminum droplets and their surroundings, heat transfer to internal insulation systems, and heat transfer to aft-end equipment. Gas conduction dominates heat feedback to the propellant surface in conventional ammonium perchlorate (AP) composite propellants, although particle radiative feedback also plays a significant role in combustion of metalized propellants. Particle radiation plays a dominant role in heat transfer to internal insulation, compared with that of convection. However, conduction by impingement of burning aluminum particles, which has not been extensively studied, may also be significant. Radiative heat loss plays an important role in determining the burning rate of molten aluminum particles due to a highly luminous, oxide particle-laden, detached flame envelope. Radiation by aluminum oxide smoke particles also plays a dominant role in heat transfer from the exhaust plume to aft-end equipment. Uncertainties in aluminum oxide particle-size distribution and optical properties still make it difficult to predict radiative plume heat transfer accurately from first principles

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

International Nuclear Information System (INIS)

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

1989-01-01

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

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).

Metabonomics-based analysis of Brachyspira pilosicoli's response to tiamulin reveals metabolic activity despite significant growth inhibition.

Science.gov (United States)

Le Roy, Caroline Ivanne; Passey, Jade Louise; Woodward, Martin John; La Ragione, Roberto Marcello; Claus, Sandrine Paule

2017-06-01

Pathogenic anaerobes Brachyspira spp. are responsible for an increasing number of Intestinal Spirochaetosis (IS) cases in livestock against which few approved treatments are available. Tiamulin is used to treat swine dysentery caused by Brachyspira spp. and recently has been used to handle avian intestinal spirochaetosis (AIS). The therapeutic dose used in chickens requires further evaluation since cases of bacterial resistance to tiamulin have been reported. In this study, we evaluated the impact of tiamulin at varying concentrations on the metabolism of B. pilosicoli using a 1 H-NMR-based metabonomics approach allowing the capture of the overall bacterial metabolic response to antibiotic treatment. Based on growth curve studies, tiamulin impacted bacterial growth even at very low concentration (0.008 μg/mL) although its metabolic activity was barely affected 72 h post exposure to antibiotic treatment. Only the highest dose of tiamulin tested (0.250 μg/mL) caused a major metabolic shift. Results showed that below this concentration, bacteria could maintain a normal metabolic trajectory despite significant growth inhibition by the antibiotic, which may contribute to disease reemergence post antibiotic treatment. Indeed, we confirmed that B. pilosicoli remained viable even after exposition to the highest antibiotic dose. This paper stresses the need to ensure new evaluation of bacterial viability post bacteriostatic exposure such as tiamulin to guarantee treatment efficacy and decrease antibiotic resistance development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Targeting fibroblast growth factor receptor signaling inhibits prostate cancer progression.

Science.gov (United States)

Feng, Shu; Shao, Longjiang; Yu, Wendong; Gavine, Paul; Ittmann, Michael

2012-07-15

Extensive correlative studies in human prostate cancer as well as studies in vitro and in mouse models indicate that fibroblast growth factor receptor (FGFR) signaling plays an important role in prostate cancer progression. In this study, we used a probe compound for an FGFR inhibitor, which potently inhibits FGFR-1-3 and significantly inhibits FGFR-4. The purpose of this study is to determine whether targeting FGFR signaling from all four FGFRs will have in vitro activities consistent with inhibition of tumor progression and will inhibit tumor progression in vivo. Effects of AZ8010 on FGFR signaling and invasion were analyzed using immortalized normal prostate epithelial (PNT1a) cells and PNT1a overexpressing FGFR-1 or FGFR-4. The effect of AZ8010 on invasion and proliferation in vitro was also evaluated in prostate cancer cell lines. Finally, the impact of AZ8010 on tumor progression in vivo was evaluated using a VCaP xenograft model. AZ8010 completely inhibits FGFR-1 and significantly inhibits FGFR-4 signaling at 100 nmol/L, which is an achievable in vivo concentration. This results in marked inhibition of extracellular signal-regulated kinase (ERK) phosphorylation and invasion in PNT1a cells expressing FGFR-1 and FGFR-4 and all prostate cancer cell lines tested. Treatment in vivo completely inhibited VCaP tumor growth and significantly inhibited angiogenesis and proliferation and increased cell death in treated tumors. This was associated with marked inhibition of ERK phosphorylation in treated tumors. Targeting FGFR signaling is a promising new approach to treating aggressive prostate cancer.

Altered association of transcriptionally active DNA with the nuclear-matrix after heat shock

NARCIS (Netherlands)

Sakkers, RJ; Brunsting, JF; Filon, AR; Kampinga, HH; Konings, AWT; Mullenders, LHF

Purpose: Exposure of human cells to heat leads to denaturation and aggregation of proteins. Within the nucleus, it has been suggested that protein aggregation is linked to the: selective inhibition by hyperthermia of nucleotide excision repair in transcriptionally active genes. Tn this study it was

Maximising the recovery of low grade heat: An integrated heat integration framework incorporating heat pump intervention for simple and complex factories

International Nuclear Information System (INIS)

Miah, J.H.; Griffiths, A.; McNeill, R.; Poonaji, I.; Martin, R.; Leiser, A.; Morse, S.; Yang, A.; Sadhukhan, J.

2015-01-01

Highlights: • A new practical heat integration framework incorporating heat pump technology for simple and complex food factories. • A decision making procedure was proposed to select process or utility heat integration in complex and diverse factories. • New stream classifications proposed to identify and compare streams linked between process and utility, especially waste heat. • A range of ‘Heat Pump Thresholds’ to identify and compare heat pump configurations with steam generation combustion boiler. - Abstract: The recovery of heat has long been a key measure to improving energy efficiency and maximising the heat recovery of factories by Pinch analysis. However, a substantial amount of research has been dedicated to conventional heat integration where low grade heat is often ignored. Despite this, the sustainability challenges facing the process manufacturing community are turning interest on low grade energy recovery systems to further advance energy efficiency by technological interventions such as heat pumps. This paper presents a novel heat integration framework incorporating technological interventions for both simple and complex factories to evaluate all possible heat integration opportunities including low grade and waste heat. The key features of the framework include the role of heat pumps to upgrade heat which can significantly enhance energy efficiency; the selection process of heat pump designs which was aided by the development of ‘Heat Pump Thresholds’ to decide if heat pump designs are cost-competitive with steam generation combustion boiler; a decision making procedure to select process or utility heat integration in complex and diverse factories; and additional stream classifications to identify and separate streams that can be practically integrated. The application of the framework at a modified confectionery factory has yielded four options capable of delivering a total energy reduction of about 32% with an economic payback

Modelling of Split Condenser Heat Pump with Limited Set of Plate Heat Exchanger Dimensions

DEFF Research Database (Denmark)

Christensen, Stefan Wuust; Elmegaard, Brian; Markussen, Wiebke Brix

2017-01-01

in parallel to different temperature levels, whereas only one stream is heated in a THP. The length/width ratio of the plate heat exchangers on the high pressure side of a SCHP was investigated to find the optimal plate dimensions with respect to minimum area of the heat exchangers. The total heat exchanger...... area was found to decrease with an increasing length/width ratio of the plates. The marginal change in heat exchanger area was shown to be less significant for heat exchangers with high length/width ratios. In practice only a limited number of plate dimensions are available and feasible...... in the production. This was investigated to find the practical potential of a SCHP compared to a THP. Using plates optimized for a SCHP in a THP, the total required heat exchanger area increased by approximately 100% for the conditions investigated in this study, indicating that available plate dimensions influence...

Antiangiogenic and Antitumor Effects of Src Inhibition in Ovarian Carcinoma

Science.gov (United States)

Han, Liz Y.; Landen, Charles N.; Trevino, Jose G.; Halder, Jyotsnabaran; Lin, Yvonne G.; Kamat, Aparna A.; Kim, Tae-Jin; Merritt, William M.; Coleman, Robert L.; Gershenson, David M.; Shakespeare, William C.; Wang, Yihan; Sundaramoorth, Raji; Metcalf, Chester A.; Dalgarno, David C.; Sawyer, Tomi K.; Gallick, Gary E.; Sood, Anil K.

2011-01-01

Src, a nonreceptor tyrosine kinase, is a key mediator for multiple signaling pathways that regulate critical cellular functions and is often aberrantly activated in a number of solid tumors, including ovarian carcinoma. The purpose of this study was to determine the role of activated Src inhibition on tumor growth in an orthotopic murine model of ovarian carcinoma. In vitro studies on HeyA8 and SKOV3ip1 cell lines revealed that Src inhibition by the Src-selective inhibitor, AP23846, occurred within 1 hour and responded in a dose-dependent manner. Furthermore, Src inhibition enhanced the cytotoxicity of docetaxel in both chemosensitive and chemoresistant ovarian cancer cell lines, HeyA8 and HeyA8-MDR, respectively. In vivo, Src inhibition by AP23994, an orally bioavailable analogue of AP23846, significantly decreased tumor burden in HeyA8 (P = 0.02), SKOV3ip1 (P = 0.01), as well as HeyA8-MDR (P < 0.03) relative to the untreated controls. However, the greatest effect on tumor reduction was observed in combination therapy with docetaxel (P < 0.001, P = 0.002, and P = 0.01, for the above models, respectively). Proliferating cell nuclear antigen staining showed that Src inhibition alone (P = 0.02) and in combination with docetaxel (P = 0.007) significantly reduced tumor proliferation. In addition, Src inhibition alone and in combination with docetaxel significantly down-regulated tumoral production of vascular endothelial growth factor and interleukin 8, whereas combination therapy decreased the microvessel density (P = 0.02) and significantly affected vascular permeability (P < 0.05). In summary, Src inhibition with AP23994 has potent antiangiogenic effects and significantly reduces tumor burden in preclinical ovarian cancer models. Thus, Src inhibition may be an attractive therapeutic approach for patients with ovarian carcinoma. PMID:16951177

Minocycline attenuates the development of diabetic neuropathy by inhibiting spinal cord Notch signaling in rat.

Science.gov (United States)

Yang, Cheng; Gao, Jie; Wu, Banglin; Yan, Nuo; Li, Hui; Ren, Yiqing; Kan, Yufei; Liang, Jiamin; Jiao, Yang; Yu, Yonghao

2017-10-01

We studied the effects of minocycline (an inhibitor of microglial activation) on the expression and activity of Notch-1 receptor, and explored the therapeutic efficacy of minocycline combined with Notch inhibitor DAPT in the treatment of diabetic neuropathic pain (DNP). Diabetic rat model was established by intraperitoneal injection (ip) of Streptozotocin (STZ). Expression and activity of Notch-1 and expression of macrophage/microglia marker Iba-1 were detected by WB. Diabetes induction significantly attenuated sciatic nerve conduction velocity, and dramatically augmented the expression and the activity of Notch-1 in the lumbar enlargement of the spinal cord. Minocycline treatment, however, accelerated the decreased conduction velocity of sciatic nerve and suppressed Notch-1expression and activity in diabetic rats. Similar to DAPT treatment, minocycline administration also prolonged thermal withdrawal latency (TWL) and increase mechanical withdrawal threshold (MWT) in diabetic rats in response to heat or mechanical stimulation via inhibition the expression and the activity of Notch-1 in spinal cord. Combination of DAPT and minocycline further inhibited Notch-1 receptor signaling and reduce neuropathic pain exhibited as improved TWL and MWT. Our study revealed a novel mechanism of Notch-1 receptor inhibition in spinal cord induced by minocycline administration, and suggested that the combination of minocycline and DAPT has the potential to treat DNP. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Heat pipe turbine vane cooling

Energy Technology Data Exchange (ETDEWEB)

Langston, L.; Faghri, A. [Univ. of Connecticut, Storrs, CT (United States)

1995-10-01

The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and an uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

Simulation study of soil water and heat dynamics at two sites with significant preferential flow

Science.gov (United States)

Votrubova, J.; Vogel, T.; Dohnal, M.; Tesar, M.

2012-04-01

Numerical models based on two hydraulically contrasting flow domains coupled through a simple transfer formula have become a useful tool for modeling both water flow and associated substance transport in structured soils. A comparative numerical study focused on the preferential flow effects on the soil heat transport is presented. Sites located in two different headwater catchments were included. Experimental catchment Liz is situated in a forested mountain area of Sumava Mts. in the southern part of the Czech Republic (altitude: 830 m, mean annual temperature: 6.3°C, mean annual precipitation: 861 mm). Uhlirska catchment is located in the north-west of the Czech Republic in Jizera Mts. and is currently undergoing reforestation (altitude: 820 m, mean annual temperature: 4.6°C, mean annual precipitation: 1400 mm). Both sites are instrumented for monitoring of the relevant meteorological and hydrological variables, as well as the soil moisture and temperature distribution. Changes of the soil water content and temperature during vegetation season were simulated. Model performance was qualitatively evaluated and shown to replicate the field measurements. The soils' heat budgets and the preferential flow effect thereon was compared and analyzed.

Heat pulse excitability of vestibular hair cells and afferent neurons

Science.gov (United States)

Brichta, Alan M.; Tabatabaee, Hessam; Boutros, Peter J.; Ahn, JoongHo; Della Santina, Charles C.; Poppi, Lauren A.; Lim, Rebecca

2016-01-01

In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT. An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in heat pulse excitability in vestibular sensory organs and provide quantitative methods for rational application of optical heat pulses to examine protein biophysics and manipulate cellular excitability. PMID:27226448

Inhibition of lignin-derived phenolic compounds to cellulase.

Science.gov (United States)

Qin, Lei; Li, Wen-Chao; Liu, Li; Zhu, Jia-Qing; Li, Xia; Li, Bing-Zhi; Yuan, Ying-Jin

2016-01-01

Lignin-derived phenolic compounds are universal in the hydrolysate of pretreated lignocellulosic biomass. The phenolics reduce the efficiency of enzymatic hydrolysis and increase the cost of ethanol production. We investigated inhibition of phenolics on cellulase during enzymatic hydrolysis using vanillin as one of the typical lignin-derived phenolics and Avicel as cellulose substrate. As vanillin concentration increased from 0 to 10 mg/mL, cellulose conversion after 72-h enzymatic hydrolysis decreased from 53 to 26 %. Enzyme deactivation and precipitation were detected with the vanillin addition. The enzyme concentration and activity consecutively decreased during hydrolysis, but the inhibition degree, expressed as the ratio of the cellulose conversion without vanillin to the conversion with vanillin (A 0 /A), was almost independent on hydrolysis time. Inhibition can be mitigated by increasing cellulose loading or cellulase concentration. The inhibition degree showed linear relationship with the vanillin concentration and exponential relationship with the cellulose loading and the cellulase concentration. The addition of calcium chloride, BSA, and Tween 80 did not release the inhibition of vanillin significantly. pH and temperature for hydrolysis also showed no significant impact on inhibition degree. The presence of hydroxyl group, carbonyl group, and methoxy group in phenolics affected the inhibition degree. Besides phenolics concentration, other factors such as cellulose loading, enzyme concentration, and phenolic structure also affect the inhibition of cellulose conversion. Lignin-blocking agents have little effect on the inhibition effect of soluble phenolics, indicating that the inhibition mechanism of phenolics to enzyme is likely different from insoluble lignin. The inhibition of soluble phenolics can hardly be entirely removed by increasing enzyme concentration or adding blocking proteins due to the dispersity and multiple binding sites of phenolics

Mask humidity during CPAP: influence of ambient temperature, heated humidification and heated tubing

Directory of Open Access Journals (Sweden)

Nilius G

2018-05-01

Full Text Available Georg Nilius,1,2 Ulrike Domanski,1 Maik Schroeder,1 Holger Woehrle,3,4 Andrea Graml,4 Karl-Josef Franke,1,2 1Helios Klinik Hagen-Ambrock, Department of Pneumology, Hagen, Germany; 2Department of Internal Medicine, Witten-Herdecke University, Witten, Germany; 3Sleep and Ventilation Center Blaubeuren, Respiratory Center Ulm, Ulm, Germany; 4ResMed Science Center, ResMed Germany, Martinsried, Germany Purpose: Mucosal drying during continuous positive airway pressure (CPAP therapy is problematic for many patients. This study assessed the influence of ambient relative humidity (rH and air temperature (T in winter and summer on mask humidity during CPAP, with and without mask leak, and with or without heated humidification ± heated tubing. Methods: CPAP (8 and 12 cmH2O without humidification (no humidity [nH], with heated humidification controlled by ambient temperature and humidity (heated humidity [HH] and HH plus heated tubing climate line (CL, with and without leakage, were compared in 18 subjects with OSA during summer and winter. Results: The absolute humidity (aH and the T inside the mask during CPAP were significantly lower in winter versus summer under all applied conditions. Overall, absolute humidity differences between summer and winter were statistically significant in both HH and CL vs. nH (p < 0.05 in the presence and absence of mouth leak. There were no significant differences in aH between HH and CL. However, in-mask temperature during CL was higher (p < 0.05 and rH lower than during HH. In winter, CPAP with CL was more likely to keep rH constant at 80% than CPAP without humidification or with standard HH. Conclusion: Clinically-relevant reductions in aH were documented during CPAP given under winter conditions. The addition of heated humidification, using a heated tube to avoid condensation is recommended to increase aH, which could be useful in CPAP users complaining of nose and throat symptoms. Keywords: continuous positive

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

Science.gov (United States)

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

2010-11-01

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

Inhibition of MMPs by alcohols

Science.gov (United States)

Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Hoshika, Tomohiro; Uchiyama, Toshikazu; Tjäderhane, Leo; Breschi, Lorenzo; Mazzoni, Annalisa; Thompson, Jeremy M.; McCracken, Courtney E.; Looney, Stephen W.; Tay, Franklin R.; Pashley, David H.

2011-01-01

Objectives While screening the activity of potential inhibitors of matrix metalloproteinases (MMPs), due to the limited water solubility of some of the compounds, they had to be solubilized in ethanol. When ethanol solvent controls were run, they were found to partially inhibit MMPs. Thus, the purpose of this study was to compare the MMP-inhibitory activity of a series of alcohols. Methods The possible inhibitory activity of a series of alcohols was measured against soluble rhMMP-9 and insoluble matrix-bound endogenous MMPs of dentin in completely demineralized dentin. Increasing concentrations (0.17, 0.86, 1.71 and 4.28 moles/L) of a homologous series of alcohols (i.e. methanol, ethanol, propanols, butanols, pentanols, hexanols, the ethanol ester of methacrylic acid, heptanols and octanol) were compared to ethanediol, and propanediol by regression analysis to calculate the molar concentration required to inhibit MMPs by 50% (i.e. the IC50). Results Using two different MMP models, alcohols were shown to inhibit rhMMP-9 and the endogenous proteases of dentin matrix in a dose-dependent manner. The degree of MMP inhibition by alcohols increased with chain length up to 4 methylene groups. Based on the molar concentration required to inhibit rhMMP-9 fifty percent, 2-hydroxyethylmethacrylate (HEMA), 3-hexanol, 3-heptanol and 1-octanol gave the strongest inhibition. Significance The results indicate that alcohols with 4 methylene groups inhibit MMPs more effectively than methanol or ethanol. MMP inhibition was inversely related to the Hoy's solubility parameter for hydrogen bonding forces of the alcohols (i.e. to their hydrophilicity). PMID:21676453

Behavior study on Na heat pipe in passive heat removal system of new concept molten salt reactor

International Nuclear Information System (INIS)

Wang Chenglong; Tian Wenxi; Su Guanghui; Zhang Dalin; Wu Yingwei; Qiu Suizheng

2013-01-01

The high temperature Na heat pipe is an effective device for transporting heat, which is characterized by remarkable advantages in conductivity, isothermally and passively working. The application of Na heat pipe on passive heat removal system of new concept molten salt reactor (MSR) is significant. The transient performance of high temperature Na heat pipe was simulated by numerical method under the MSR accident. The model of the Na heat pipe was composed of three conjugate heat transfer zones, i.e. the vapor, wick and wall. Based on finite element method, the governing equations were solved by making use of FORTRAN to acquire the profiles of the temperature, velocity and pressure for the heat pipe transient operation. The results show that the high temperature Na heat pipe has a good performance on operating characteristics and high heat transfer efficiency from the frozen state. (authors)

Effect of maize silage addition on biomethane recovery from mesophilic co-digestion of chicken and cattle manure to suppress ammonia inhibition

International Nuclear Information System (INIS)

Yangin-Gomec, Cigdem; Ozturk, Izzet

2013-01-01

Highlights: • Daily biomethane and total energy productions improved 1.2 fold when maize silage is co-digested with the animal wastes. • Heat produced is sufficient for successful mesophilic co-digestion with an energy saving ∼36 × 10 3 kW h with maize silage. • Excess heat up to 16 × 10 3 kW h can be utilized elsewhere in the premises of the biogas plant. • Biogas plants including co-digestion of manure with a suitable co-substrate are becoming net producers of renewable energy. • pH values above 7.4 may cause severe inhibition of methanogenic cultures for an unadapted process to NH 3 . - Abstract: The aim of this study is to evaluate the biogas recovery potential if mesophilic (35 ± 2 °C) anaerobic co-digestion of two different types of manure sources (from chicken and cattle) is applied at a biogas plant. In order to evaluate the improvement in biogas production in the presence of the co-substrate, maize silage is digested together with the animal manure. Results indicated that daily biomethane and total energy (power + heat) productions improved about 1.2 fold when maize silage is co-digested with cattle and chicken wastes. The heat and power energy potentials from the produced biogas were determined using the conversion rates of a CHP unit. Significant energy recovery could be achieved for both cases; i.e. total methane productions were calculated as 5800 and 6580 m 3 /day corresponding to total energy productions of some 45.05 × 10 3 and 51.06 × 10 3 kW h without and with maize silage addition, respectively. A heat analysis was also performed where the resulting biomethane productions were the basis of the heat requirements. Results indicated that the major part of the heating requirements consisted of slurry heating to the operating temperature (in this study 35 °C). When the overall heat requirements are compared to the heat potential from a CHP unit, it is clear that the heat produced is sufficient for successful mesophilic co

AGN Heating Through Cavities and Shocks

NARCIS (Netherlands)

Nulsen, P.E.J.; Jones, C.; Forman, W.R.; David, L.P.; McNamara, B.R.; Rafferty, D.A.; Bîrzan, L.; Wise, M.

2007-01-01

Three comments are made on AGN heating of cooling flows. A simple physical argument is used to show that the enthalpy of a buoyant radio lobe is converted to heat in its wake. Thus, a significant part of ``cavity'' enthalpy is likely to end up as heat. Second, the properties of the repeated weak

MATHEMATICAL MODELLING OF OPERATION HEAT NETWORKS IN VIEW OF HEAT LOSS

Directory of Open Access Journals (Sweden)

ZBARAZ L. I.

2016-08-01

Full Text Available Goal. In recent years, due to a significant rise in price of energy, the reduction of direct costs for heating becomes a priority. In the utilities especially important to optimization of energy heating system equipment. During transport of thermal energy in the distribution networks thermal losses occur along the length of the hydraulic pipes and the coolant pumping losses. These loss-dependence of the particular distribution network. Changing temperature and the hydraulic regime at the source necessary to achieve the minimum cost of transport for today acting tariffs for energy. Scientific novelty. The studies received law changes head to the source at the qualitative and quantitative methods of regulation. Results. A mathematical model of an extensive network of decentralized heat source heating, which are analyzed using different methods of regulating and found the best.

Heat Tolerance Induction of the Indian Meal Moth (Lepidoptera: Pyralidae) Is Accompanied by Upregulation of Heat Shock Proteins and Polyols.

Science.gov (United States)

Kim, Minhyun; Lee, Seunghee; Chun, Yong Shik; Na, Jahyun; Kwon, Hyeok; Kim, Wook; Kim, Yonggyun

2017-08-01

The Indian meal moth, Plodia interpunctella, causes massive damage to stored grains and processed foods. Heat treatment has been widely used to control insect pests infesting stored grains. However, heat treatment may result in unsatisfactory control owing to heat tolerance of target insects. This study quantified the heat tolerance and analyzed its induction in P. interpunctella. Susceptibility of P. interpunctella to different high temperatures was assessed in all developmental stages. Heat treatment at 44 °C for 1 h caused significant mortalities to all developmental stages, with late-instar larvae exhibiting the highest tolerance. However, the survivorship to heat treatment was significantly increased by pre-exposure to 37 °C for 30 min. The induction of heat tolerance was accompanied by upregulation of two heat shock proteins of Hsc70 and Hsp90. Trehalose and glycerol concentrations in the hemolymph also increased after pre-exposure to 37 °C for 30 min. RNA interference (RNAi) by specific double-stranded RNAs effectively suppressed the inducible expressions of both Hsc70 and Hsp90 in response to 37 °C for 30 min. Either RNAi of Hsc70 or Hsp90 significantly impaired the heat tolerance induction of P. interpunctella. These results suggest that the induction of heat tolerance in P. interpunctella involves the upregulation of these heat shock proteins and hemolymph polyol levels. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

In vitro evaluation of single- and multi-strain probiotics: Inter-species inhibition between probiotic strains, and inhibition of pathogens.

Science.gov (United States)

Chapman, C M C; Gibson, G R; Rowland, I

2012-08-01

Many studies comparing the effects of single- and multi-strain probiotics on pathogen inhibition compare treatments with different concentrations. They also do not examine the possibility of inhibition between probiotic strains with a mixture. We tested the ability of 14 single-species probiotics to inhibit each other using a cross-streak assay, and agar spot test. We then tested the ability of 15 single-species probiotics and 5 probiotic mixtures to inhibit Clostridium difficile, Escherichia coli and S. typhimurium, using the agar spot test. Testing was done with mixtures created in two ways: one group contained component species incubated together, the other group of mixtures was made using component species which had been incubated separately, equalised to equal optical density, and then mixed in equal volumes. Inhibition was observed for all combinations of probiotics, suggesting that when used as such there may be inhibition between probiotics, potentially reducing efficacy of the mixture. Significant inter-species variation was seen against each pathogen. When single species were tested against mixtures, the multi-species preparations displayed significantly (p probiotic species will inhibit each other when incubated together in vitro, in many cases a probiotic mixture was more effective at inhibiting pathogens than its component species when tested at approximately equal concentrations of biomass. This suggests that using a probiotic mixture might be more effective at reducing gastrointestinal infections, and that creating a mixture using species with different effects against different pathogens may have a broader spectrum of action that a single provided by a single strain. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nickel-hydrogen battery self-discharge mechanism and methods for its inhibition

Science.gov (United States)

Visintin, Arnaldo; Anani, Anaba; Srinivasan, Supramaniam; Appleby, A. J.; Lim, Hong S.

1992-01-01

A review of our studies on the elucidation of the self-discharge mechanism of the Ni/H2 battery and methods to inhibit this phenomena is presented. The results show that (1) the rate of heat generation from nickel hydroxide powders and from electrodes increases with increase of hydrogen pressure, simultaneously, the open-circuit potential of the nickel hydroxide electrode is shifted in a negative direction more rapidly, indicating the transformation of NiOOH to Ni(OH)2; (2) heat generation rates measured in the microcalorimeter are considerably faster for electrolyte starved electrodes than for electrolyte-flooded electrodes; (3) there is a good correlation between the extent of self-discharge, as determined by heat generation in microcalorimetric measurement and capacity change; and (4) the self-discharge in Ni/H2 battery occurs via direct reduction of the active material by pressurized hydrogen. The addition of cadmium to the electrode reduces the self-discharge.

A heat transfer correlation for transient vapor uptake of powdered adsorbent embedded onto the fins of heat exchangers

KAUST Repository

Li, Ang

2015-10-23

We present a detailed study on the transient heat transfer phenomena of powdered-adsorbent mixed with an organic binder for adherence to the fins of a heat exchangers. The transient performance of such an adsorbent-heat exchanger configuration has significant application potential in the adsorption desalination plants and chillers but seldom addressed in the literature. An experiment is designed to measure the heat transfer for several adsorption temperatures under a single vapor component environment. Analysis on the experimental data indicates that the adsorbent-adsorbate interactions contribute about 75% of the total thermal resistances throughout the uptake processes. It is found that the initial local adsorption heat transfer coefficients are significantly higher than the average values due primarily to the thermal mass effect of the adsorbent–adsorbate interaction layers. From these experiments, a correlation for the transient local adsorption heat transfer coefficients is presented at the sub-atmospheric pressures and assorted application temperatures.

Air-source heat pump carbon footprints: HFC impacts and comparison to other heat sources

International Nuclear Information System (INIS)

Johnson, Eric P.

2011-01-01

European governments see that heat pumps could reduce carbon emissions in space- and hot-water heating. EU's Renewable Energy Directive designates heat pumps as renewable - eligible for various subsidies - if their carbon footprints are below an implied, average threshold. This threshold omits carbon generated by manufacture and emission of a heat-pump's fluorocarbon refrigerant. It also omits the footprint of the heat pump's hardware. To see if these omissions are significant, this study calculated carbon footprints of representative, residential heat pumps in the UK. Three findings emerged. First, in relation to power generation, which accounts for most of a heat-pump's greenhouse-gas emissions, fluorocarbons add another 20% to the footprint. Second, at UK efficiencies a heat-pump footprint (in kg CO 2 e emitted per kWh delivered) is comparable or higher than footprints of gaseous fuels used in heating. It is lower than the footprint of heating oil and far lower than the footprints of solid fuels. Third, production and disposal of a heat pump's hardware is relatively insignificant, accounting for only 2-3% of the overall heat-pump footprint. Sensitivities to the results were assessed: key factors are footprint of electricity generation, F-gas composition and leak rates and type of wall construction. - Research highlights: → Refrigerant emissions add 20% to a UK air-source heat pump's carbon footprint. → This contribution is so far ignored by regulations. → UK heat pump footprints are comparable to those of gaseous fuels.

Influence of heat stress on leaf morphology and nitrogen–carbohydrate metabolisms in two wucai (Brassica campestris L. genotypes

Directory of Open Access Journals (Sweden)

Lingyun Yuan

2017-06-01

Full Text Available Heat stress is a major environmental stress that limits plant growth and yield worldwide. The present study was carried out to explore the physiological mechanism of heat tolerant to provide the theoretical basis for heat-tolerant breeding. The changes of leaf morphology, anatomy, nitrogen assimilation, and carbohydrate metabolism in two wucai genotypes (WS-1, heat tolerant; WS-6, heat sensitive grown under heat stress (40°C/30°C for 7 days were investigated. Our results showed that heat stress hampered the plant growth and biomass accumulation in certain extent in WS-1 and WS-6. However, the inhibition extent of WS-1 was significantly smaller than WS-6. Thickness of leaf lamina, upper epidermis, and palisade mesophyll were increased by heat in WS-1, which might be contributed to the higher assimilation of photosynthates. During nitrogen assimilation, WS-1 possessed the higher nitrogen-related metabolic enzyme activities, including nitrate reductase (NR, glutamine synthetase (GS, glutamate synthase (GOGAT, and glutamate dehydrogenase (GDH, which were reflected by higher photosynthetic nitrogen-use efficiency (PNUE with respect to WS-6. The total amino acids level had no influence in WS-1, whereas it was reduced in WS-6 by heat. And the proline contents of both wucai genotypes were all increased to respond the heat stress. Additionally, among all treatments, the total soluble sugar content of WS-1 by heat got the highest level, including higher contents of sucrose, fructose, and starch than those of WS-6. Moreover, the metabolism efficiency of sucrose to starch in WS-1 was greater than WS-6 under heat stress, proved by higher activities of sucrose phosphate synthase (SPS, sucrose synthase (SuSy, acid invertase (AI, and amylase. These results demonstrated that leaf anatomical alterations resulted in higher nitrogen and carbon assimilation in heat-tolerant genotype WS-1, which exhibited a greater performance to resist heat stress.

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.

An experimental observation of the effect of flow direction for evaporation heat transfer in plate heat exchanger

International Nuclear Information System (INIS)

Lin, Yueh-Hung; Li, Guang-Cheng; Yang, Chien-Yuh

2015-01-01

This study provides an Infrared Thermal Image observation on the evaporation heat transfer of refrigerant R-410A in plate heat exchanger with various flow arrangement and exit superheat conditions. An experimental method was derived for estimating the superheat region area of two-phase refrigerant evaporation in plate heat exchanger. The experimental results show that the superheat region area for parallel flow is much larger than that for counter flow as that estimated by Yang et al. [9]. There is an early superheated region at the central part of the plate heat exchanger for parallel flow arrangement. This effect is not significant for counter flow arrangement. The Yang et al. [9] method under estimated the superheat area approximately 40%–53% at various flow rates and degree of exit superheat. Even though the flow inside a plate heat exchanger is extremely turbulent because of the chevron flow passages, the assumption of uniform temperature distribution in the cross section normal to the bulk flow direction will cause significant uncertainties for estimating the superheat area for refrigerant evaporating in a plate heat exchanger

Interactions between urban heat islands and heat waves

Science.gov (United States)

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

2018-03-01

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

Chapter 12. Space Heating Equipment

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin D.

1998-01-01

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

Production of molten UO2 pools by internal heating: apparatus and preliminary experimental heat transfer results

International Nuclear Information System (INIS)

Chasanov, M.G.; Gunther, W.H.; Baker, L. Jr.

1977-01-01

The capability for removal of heat from a pool of molten fuel under postaccident conditions is an important consideration in liquid-metal fast breeder reactor safety analysis. No experimental data for pool heat transfer from molten UO 2 under conditions simulating internal heat generation by fission product decay have been reported previously in the literature. An apparatus to provide such data was developed and used to investigate heat transfer from pools containing up to 7.5 kg of UO 2 ; the internal heat generation rates and pool depths attained cover most of the ranges of interest for postaccident heat removal analysis. It was also observed in these studies that the presence of simulated fission products corresponding to approximately 150,000 kW-day/kg burnup had no significant effect on the observed heat transfer

Effect of nitrite on the microbiological stability of canned Vienna sausages preserved by mild heat treatment or combinations of heat and irradiation

International Nuclear Information System (INIS)

Farkas, J.; Zukal, E.; Incze, K.

1973-01-01

Keeping quality of Vienna sausages packed in No. 1/5 cans (ca 200 g) with salt brine and heat treated with F 0 values in the range of 0.25-0.55 was studied as a function of sodium nitrate addition. In uninoculated cans the heat requirement of preservation proved to be about 0.3 F 0 in the presence of 300 ppm NaNO 2 . A heat treatment of 0.55 F 0 and 200 ppm NaNO 2 resulted in higher microbiological stability of cans inoculated with 2x10 4 /tin Clostridium sporogenes spores than a heat treatment of 1.9 F 0 without nitrite addition. The effect of the combination of heat treatment of 0.35-0.55 F 0 and 0.45 Mrad of gamma irradiation was also studied with inoculated cans. The combination of irradiation plus heat resulted in a higher microbiological stability of the samples than the reversed order of the treatments, but this synergistic effect could not be proved in all experiments. The addition of 200 ppm NaNO 2 was not as effective in increasing the shelf-life of combination treated samples as with the solely heat treated ones. In a medium composed of a 50% extract of Vienna sausages (pH 6.4, asub(w) 0.96) and inoculated with 10 5 per ml Clostridium sporogenes spores 100 ppm or more NaNO 2 was required to ensure microbiological stability of samples heat treated with F 0 0.4. In the range of the permitted concentration level for canned meat products, sodium nitrite did not influence the heat resistance of Clostridium sporogenes, but inhibited the germination of the surviving spores. (F.J.)

Experimental investigations on heat content of supercooled sodium acetate trihydrate by a simple heat loss method

DEFF Research Database (Denmark)

Kong, Weiqiang; Dannemand, Mark; Johansen, Jakob Berg

2016-01-01

Sodium acetate trihydrate is a phase change material that can be used for long term heat storage in solar heating systems because of its relatively high heat of fusion, a melting temperature of 58 °C and its ability to supercool stable. In practical applications sodium acetate trihydrate tend to ......, 0.3–0.5 % (wt.%) Xanthan Gum or 1–2% (wt.%) of some solid or liquid polymers as additives had significantly higher heat contents compared to samples of sodium acetate trihydrate suffering from phase separation....

Effects of heat stress and starvation on clonal odontoblast-like cells.

Science.gov (United States)

Morotomi, Takahiko; Kitamura, Chiaki; Toyono, Takashi; Okinaga, Toshinori; Washio, Ayako; Saito, Noriko; Nishihara, Tatsuji; Terashita, Masamichi; Anan, Hisashi

2011-07-01

Heat stress during restorative procedures, particularly under severe starvation conditions, can trigger damage to dental pulp. In the present study, we examined effects of heat stress on odontoblastic activity and inflammatory responses in an odontoblast-like cell line (KN-3) under serum-starved conditions. Viability, nuclear structures, and inflammatory responses of KN-3 cells were examined in culture medium containing 10% or 1% serum after exposure to heat stress at 43°C for 45 minutes. Gene expression of extracellular matrices, alkaline phosphatase activity, and detection of extracellular calcium deposition in cells exposed to heat stress were also examined. Reduced viability and apoptosis were transiently induced in KN-3 cells during the initial phases after heat stress; thereafter, cells recovered their viability. The cytotoxic effects of heat stress were enhanced under serum-starved conditions. Heat stress also strongly up-regulated expression of heat shock protein 25 as well as transient expression of tumor necrosis factor-alpha, interleukin-6, and cyclooxygenase-2 in KN-3 cells. In contrast, expression of type-1 collagen, runt-related transcription factor 2, and dentin sialophosphoprotein were not inhibited by heat stress although starvation suppressed ALP activity and delayed progression of calcification. Odontoblast-like cells showed thermoresistance with transient inflammatory responses and without loss of calcification activity, and their thermoresistance and calcification activity were influenced by nutritional status. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Heat pipes in modern heat exchangers

International Nuclear Information System (INIS)

Vasiliev, Leonard L.

2005-01-01

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

Heat shock protein 90 in neurodegenerative diseases

Directory of Open Access Journals (Sweden)

Rodina Anna

2010-06-01

Full Text Available Abstract Hsp90 is a molecular chaperone with important roles in regulating pathogenic transformation. In addition to its well-characterized functions in malignancy, recent evidence from several laboratories suggests a role for Hsp90 in maintaining the functional stability of neuronal proteins of aberrant capacity, whether mutated or over-activated, allowing and sustaining the accumulation of toxic aggregates. In addition, Hsp90 regulates the activity of the transcription factor heat shock factor-1 (HSF-1, the master regulator of the heat shock response, mechanism that cells use for protection when exposed to conditions of stress. These biological functions therefore propose Hsp90 inhibition as a dual therapeutic modality in neurodegenerative diseases. First, by suppressing aberrant neuronal activity, Hsp90 inhibitors may ameliorate protein aggregation and its associated toxicity. Second, by activation of HSF-1 and the subsequent induction of heat shock proteins, such as Hsp70, Hsp90 inhibitors may redirect neuronal aggregate formation, and protect against protein toxicity. This mini-review will summarize our current knowledge on Hsp90 in neurodegeneration and will focus on the potential beneficial application of Hsp90 inhibitors in neurodegenerative diseases.

Potential of waste heat in Croatian industrial sector

Directory of Open Access Journals (Sweden)

Bišćan Davor

2012-01-01

Full Text Available Waste heat recovery in Croatian industry is of the highest significance regarding the national efforts towards energy efficiency improvements and climate protection. By recuperation of heat which would otherwise be wasted, the quantity of fossil fuels used for production of useful energy could be lowered thereby reducing the fuel costs and increasing the competitiveness of examined Croatian industries. Another effect of increased energy efficiency of industrial processes and plants is reduction of greenhouse gases i.e. the second important national goal required by the European Union (EU and United Nations Framework Convention on Climate Change (UNFCCC. Paper investigates and analyses the waste heat potential in Croatian industrial sector. Firstly, relevant industrial sectors with significant amount of waste heat are determined. Furthermore, significant companies in these sectors are selected with respect to main process characteristics, operation mode and estimated waste heat potential. Data collection of waste heat parameters (temperature, mass flow and composition is conducted. Current technologies used for waste heat utilization from different waste heat sources are pointed out. Considered facilities are compared with regard to amount of flue gas heat. Mechanisms for more efficient and more economic utilization of waste heat are proposed. [Acknoledgment. The authors would like to acknowledge the financial support provided by the UNITY THROUGH KNOWLEDGE FUND (UKF of the Ministry of Science, Education and Sports of the Republic of Croatia and the World Bank, under the Grant Agreement No. 89/11.

Effects of heat treatment on conformation and cell growth activity of alpha- lactalbumin and beta-lactoglobulin from market milk.

Science.gov (United States)

Inagaki, Mizuho; Kawai, Shuji; Ijier, X; Fukuoka, Mayuko; Yabe, Tomio; Iwamoto, Satoshi; Kanamaru, Yoshihiro

2017-01-01

Heat processes, low temperature for long time (LTLT) pasteurization and ultra-heat treatment (UHT) sterilization, are essential for commercial market milk to improve the shelf life of raw milk and ensure microbial safety. We evaluated the effects of heat experience on the molecular properties of α-lactalbumin (α-LA) and β-lactoglobulin (β-LG) isolated from four types of market milk such as LTLT-A (66°C for 30 min), LTLT-B (65°C for 30 min), UHT-I (130°C for 2 s, indirect heating) and UHT-D (135°C for 2 s, direct heating) samples. We examined molecular conformations using circular dichroism spectrum measurement and cell growth activity using the WST-1 method for the proteins. α-LA isolated from each of these four types of market milk displayed no significant structural difference as compared to raw milk α-LA, while α-LA of UHT-I only inhibited cell growth of an intestinal epithelial cell line more potently than raw milk α-LA. In the case of β-LG, only the UHT-I sample demonstrated a drastic change in structure, while it did not exhibit any cytotoxicity. We found that cell viability effects of α-LA and β-LG are attributable to the type of UHT; indirect and direct. These findings indicate that the effect of heat treatment on whey proteins should carefully be investigated further.

Geothermal source heat pump performance for a greenhouse heating system: an experimental study

Directory of Open Access Journals (Sweden)

Alexandros Sotirios Anifantis

2016-09-01

Full Text Available Greenhouses play a significant function in the modern agriculture economy even if require great amount of energy for heating systems. An interesting solution to alleviate the energy costs and environmental problems may be represented by the use of geothermal energy. The aim of this paper, based on measured experimental data, such as the inside greenhouse temperature and the heat pump performance (input and output temperatures of the working fluid, electric consumption, was the evaluation of the suitability of low enthalpy geothermal heat sources for agricultural needs such as greenhouses heating. The study was carried out at the experimental farm of the University of Bari, where a greenhouse was arranged with a heating system connected to a ground-source heat pump (GSHP, which had to cover the thermal energy request. The experimental results of this survey highlight the capability of the geothermal heat source to ensue thermal conditions suitable for cultivation in greenhouses even if the compressor inside the heat pump have operated continuously in a fluctuating state without ever reaching the steady condition. Probably, to increase the performance of the heat pump and then its coefficient of performance within GSHP systems for heating greenhouses, it is important to analyse and maximise the power conductivity of the greenhouse heating system, before to design an expensive borehole ground exchanger. Nevertheless, according to the experimental data obtained, the GSHP systems are effective, efficient and environmental friendly and may be useful to supply the heating energy demand of greenhouses.

Kindergarteners' self-reported social inhibition and observed social reticence: moderation by adult-reported social inhibition and social anxiety disorder symptoms.

Science.gov (United States)

Kiel, Elizabeth J; Buss, Kristin A; Molitor, Joseph G

2015-04-01

Prevention of later anxiety problems would best be accomplished by identifying at-risk children early in development. For example, children who develop Social Anxiety Disorder (SAD) may show social withdrawal in the form of social inhibition (i.e., shyness with unfamiliar adults and peers) at school entry. Although the use of children's perceptions of their own social inhibition would provide insight into early risk, the utility of young children's self-reports remains unclear. The current study examined whether children deemed more extreme on social inhibition or social anxiety by adult report provided self-report of social inhibition that related to observed social reticence in the laboratory. Participants included 85 kindergarten children (36 female, 49 male), their parents, and their teachers. Moderation analyses revealed that children's self-reported social inhibition related significantly to observed social reticence under the conditions of high parent-reported social inhibition, high teacher-reported social inhibition, and high SAD symptoms. These results suggest that the most inhibited children are aware of their behavior and can report it in a meaningfully way as young as kindergarten age.

Combined heat and power considered as a virtual steam cycle heat pump

International Nuclear Information System (INIS)

Lowe, Robert

2011-01-01

The first aim of this paper is to shed light on the thermodynamic reasons for the practical pursuit of low temperature operation by engineers involved in the design and the operation of combined heat and power (CHP) and district heating (DH) systems. The paper shows that the steam cycle of a combined heat and power generator is thermodynamically equivalent to a conventional steam cycle generator plus an additional virtual steam cycle heat pump. This apparently novel conceptualisation leads directly to (i) the observed sensitivity of coefficient of performance of CHP to supply and return temperatures in associated DH systems, and (ii) the conclusion that the performance of CHP will tend to be significantly higher than real heat pumps operating at similar temperatures. The second aim, which is pursued more qualitatively, is to show that the thermodynamic performance advantages of CHP are consistent with the goal of deep, long-term decarbonisation of industrialised economies. As an example, estimates are presented, which suggest that CHP based on combined-cycle gas turbines with carbon capture and storage has the potential to reduce the carbon intensity of delivered heat by a factor of ∼30, compared with a base case of natural gas-fired condensing boilers. - Highlights: → Large-scale CHP systems are thermodynamically equivalent to virtual steam cycle heat pumps. → COPs of such virtual heat pumps are necessarily better than the Carnot limit for real heat pumps. → COPs can approach 9 for plant matched to district heating systems with flow temperatures of 90 deg. C. → CHP combined with CCGT and CCS can reduce the carbon intensity of delivered heat ∼30-fold.

Heating and current drive on NSTX

Science.gov (United States)

Wilson, J. R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C. K.; Rogers, J. H.; Schilling, G.

1997-04-01

Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (˜45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation.

Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

Energy Technology Data Exchange (ETDEWEB)

Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T. [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India); Wani, Mohan R., E-mail: mohanwani@nccs.res.in [National Center for Cell Science, University of Pune Campus, Pune 411 007 (India)

2010-09-03

Research highlights: {yields} IL-3 inhibits receptor activator of NF-{kappa}B ligand (RANKL)-induced osteoclastogenesis. {yields} IL-3 inhibits RANKL-induced JNK activation. {yields} IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. {yields} IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. {yields} IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-{kappa}B (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

Irreversible inhibition of RANK expression as a possible mechanism for IL-3 inhibition of RANKL-induced osteoclastogenesis

International Nuclear Information System (INIS)

Khapli, Shruti M.; Tomar, Geetanjali B.; Barhanpurkar, Amruta P.; Gupta, Navita; Yogesha, S.D.; Pote, Satish T.; Wani, Mohan R.

2010-01-01

Research highlights: → IL-3 inhibits receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. → IL-3 inhibits RANKL-induced JNK activation. → IL-3 down-regulates expression of c-Fos and NFATc1 transcription factors. → IL-3 down-regulates RANK expression posttranscriptionally and irreversibly. → IL-3 inhibits in vivo RANK expression. -- Abstract: IL-3, a cytokine secreted by activated T lymphocytes, stimulates the proliferation, differentiation and survival of pluripotent hematopoietic stem cells. In this study, we investigated the mechanism of inhibitory action of IL-3 on osteoclast differentiation. We show here that IL-3 significantly inhibits receptor activator of NF-κB (RANK) ligand (RANKL)-induced activation of c-Jun N-terminal kinase (JNK). IL-3 down-regulates expression of c-Fos and nuclear factor of activated T cells (NFATc1) transcription factors. In addition, IL-3 down-regulates RANK expression posttranscriptionally in both purified osteoclast precursors and whole bone marrow cells. Furthermore, the inhibitory effect of IL-3 on RANK expression was irreversible. Interestingly, IL-3 inhibits in vivo RANK expression in mice. Thus, we provide the first evidence that IL-3 irreversibly inhibits RANK expression that results in inhibition of important signaling molecules induced by RANKL.

Analyzing variables for district heating collaborations between energy utilities and industries

International Nuclear Information System (INIS)

Thollander, P.; Svensson, I.L.; Trygg, L.

2010-01-01

One vital means of raising energy efficiency is to introduce district heating in industry. The aim of this paper is to study factors which promote and inhibit district heating collaborations between industries and utilities. The human factors involved showed to affect district heating collaborations more than anything else does. Particularly risk, imperfect and asymmetric information, credibility and trust, inertia and values are adequate variables when explaining the establishment or failure of industry-energy utility collaborations, while heterogeneity, access to capital and hidden costs appear to be of lower importance. A key conclusion from this study is that in an industry-energy utility collaboration, it is essential to nurture the business relationship. In summary, successful collaboration depends more on the individuals and organizations involved in the relationship between the two parties than on the technology used in the collaboration.

Heat transfer analysis of frictional heat dissipation during articulation of femoral implants.

Science.gov (United States)

Davidson, J A; Gir, S; Paul, J P

1988-12-01

Previous studies have shown the tendency for frictional heating to occur during articulation of total hip systems in vitro under simulated hip loading conditions. The magnitude of this heating is sufficient to accelerate wear, creep, and oxidation degradation of the UHMWPE bearing surface. It was shown that ceramic articulating systems generate less frictional heating than polished cobalt alloy against UHMWPE. This frictional heating is expected to occur primarily for younger, heavier, and more active patients. Thus, long-term performance of the articulating hip system in these patients may not be that predicted from current, body-temperature wear, creep, and degradation studies. Although the tendency to generate frictional heat has been observed only during in vitro simulated hip loading, a heat transfer analysis of this phenomenon is presented to evaluate the ability of the hip joint to dissipate such heating in vivo. Additional experiments were performed using controlled resistance heaters inside a cobalt femoral head to verify the calculated levels of frictional heat and to assess the heat dissipation under simulated in vivo conditions. The effect of blood perfusion on the effective thermal conductivity of the joint capsule is also discussed. The present study describes and analyzes the various heat dissipation mechanisms present both in vitro and in vivo during articulation of metal and ceramic hip systems. From these tests and analyses, it is concluded that frictional heating in the reconstructed hip cannot be effectively removed, and that degredative elevated temperature processes can be expected to occur in vivo to both the UHMWPE and adjacent tissue under extended periods of excessive patient activity. This is particularly true for metal cobalt alloy femoral heads articulating on UHMWPE versus ceramic heads which generate significantly lower levels of heat.

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

Cooling and heating performances of a CO2 heat pump with the variations of operating conditions

International Nuclear Information System (INIS)

Baek, Chang Hyun; Lee, Eung Chan; Kang, Hun; Kim, Yong Chan; Cho, Hong Hyun

2008-01-01

Since operating conditions are significantly different for heating and cooling mode operations in a CO 2 heat pump system, it is difficult to optimize the performance of the CO 2 cycle. In addition, the performance of a CO 2 heat pump is very sensitive to outdoor temperature and gascooler pressure. In this study, the cooling and heating performances of a variable speed CO 2 heat pump with a twin-rotary compressor were measured and analyzed with the variations of EEV opening and compressor frequency. As a result, the cooling and heating COPs were 2.3 and 3.0, respectively, when the EEV opening was 22%. When the optimal EEV openings for heating and cooling were 28% and 16%, the cooling and heating COPs increased by 3.3% and 3.9%, respectively, over the COPs at the EEV opening of 22%. Beside, the heating performance was more sensitive to EEV opening than the cooling performance. As the compressor speed decreased by 5 Hz, the cooling COP increased by 2%, while the heating COP decreased by 8%

Simple, economical heat-shock devices for zebrafish housing racks.

Science.gov (United States)

Duszynski, Robert J; Topczewski, Jacek; LeClair, Elizabeth E

2011-12-01

One reason for the popularity of the zebrafish (Danio rerio) as a model vertebrate is the ability to manipulate gene expression in this organism. A common method is to induce gene expression transiently under control of a heat-shock promoter (e.g., hsp70l). By making simple mechanical adjustments to small aquarium heaters (25-50W), we were able to produce consistent and reliable heat-shock conditions within a conventional zebrafish housing system. Up to two heat-shock intervals per day (>37°C) could be maintained under conditions of continuous flow (5-25 mL/min). Temperature logging every 30 s indicated rapid warm up times, consistent heat-shock lengths, and accurate and precise peak water temperatures (mean±SD=38°C±0.2°C). The biological effects of these heat-shock treatments were confirmed by observing inducible expression of enhanced green fluorescent protein (EGFP) and inhibition of caudal fin regeneration in a transgenic fish line expressing a dominant negative fibroblast growth factor receptor (Tg(hsp70l:dnfgfr1-EGFP)(pd1)). These devices are inexpensive, easily modified, and can be calibrated to accommodate a variety of experimental designs. After setup on a programmable timer, the heaters require no intervention to produce consistent daily heat shocks, and all other standard care protocols can be followed in the fish facility. The simplicity and stability of these devices make them suitable for long-term heat shocks at any stage of the zebrafish lifecycle (>7 days postfertilization), and useful for both laboratory and classroom experiments on transgenic zebrafish.

Heat transfer in melt ponds with convection and radiative heating: observationally-inspired modelling

Science.gov (United States)

Wells, A.; Langton, T.; Rees Jones, D. W.; Moon, W.; Kim, J. H.; Wilkinson, J.

2016-12-01

Melt ponds have key impacts on the evolution of Arctic sea ice and summer ice melt. Small changes to the energy budget can have significant consequences, with a net heat-flux perturbation of only a few Watts per square metre sufficient to explain the thinning of sea ice over recent decades. Whilst parameterisations of melt-pond thermodynamics often assume that pond temperatures remain close to the freezing point, recent in-situ observations show more complex thermal structure with significant diurnal and synoptic variability. We here consider the energy budget of melt ponds and explore the role of internal convective heat transfer in determining the thermal structure within the pond in relatively calm conditions with low winds. We quantify the energy fluxes and temperature variability using two-dimensional direct numerical simulations of convective turbulence within a melt pond, driven by internal radiative heating and surface fluxes. Our results show that the convective flow dynamics are modulated by changes to the incoming radiative flux and sensible heat flux at the pond surface. The evolving pond surface temperature controls the outgoing longwave emissions from the pond. Hence the convective flow modifies the net energy balance of a melt pond, modulating the relative fractions of the incoming heat flux that is re-emitted to the atmosphere or transferred downward into the sea ice to drive melt.

BOLD responses in somatosensory cortices better reflect heat sensation than pain.

Science.gov (United States)

Moulton, Eric A; Pendse, Gautam; Becerra, Lino R; Borsook, David

2012-04-25

The discovery of cortical networks that participate in pain processing has led to the common generalization that blood oxygen level-dependent (BOLD) responses in these areas indicate the processing of pain. Physical stimuli have fundamental properties that elicit sensations distinguishable from pain, such as heat. We hypothesized that pain intensity coding may reflect the intensity coding of heat sensation during the presentation of thermal stimuli during fMRI. Six 3T fMRI heat scans were collected for 16 healthy subjects, corresponding to perceptual levels of "low innocuous heat," "moderate innocuous heat," "high innocuous heat," "low painful heat," "moderate painful heat," and "high painful heat" delivered by a contact thermode to the face. Subjects rated pain and heat intensity separately after each scan. A general linear model analysis detected different patterns of brain activation for the different phases of the biphasic response to heat. During high painful heat, the early phase was associated with significant anterior insula and anterior cingulate cortex activation. Persistent responses were detected in the right dorsolateral prefrontal cortex and inferior parietal lobule. Only the late phase showed significant correlations with perceptual ratings. Significant heat intensity correlated activation was identified in contralateral primary and secondary somatosensory cortices, motor cortex, and superior temporal lobe. These areas were significantly more related to heat ratings than pain. These results indicate that heat intensity is encoded by the somatosensory cortices, and that pain evaluation may either arise from multimodal evaluative processes, or is a distributed process.

Heat wave vulnerability classification of residential buildings

NARCIS (Netherlands)

Heijden, van der M.G.M.; Blocken, B.J.E.; Hensen, J.L.M.

2012-01-01

General circulation models of climate change predict that the intensity and frequency of heat waves will increase, which are a significant threat to public health (Luber and McGeehin 2008). The effect of heat waves on the public health became apparent during the 2003 heat wave in France, where

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.

Differential expression of heat shock transcription factors and heat shock proteins after acute and chronic heat stress in laying chickens (Gallus gallus).

Science.gov (United States)

Xie, Jingjing; Tang, Li; Lu, Lin; Zhang, Liyang; Xi, Lin; Liu, Hsiao-Ching; Odle, Jack; Luo, Xugang

2014-01-01

Heat stress due to high environmental temperature negatively influences animal performances. To better understand the biological impact of heat stress, laying broiler breeder chickens were subjected either to acute (step-wisely increasing temperature from 21 to 35°C within 24 hours) or chronic (32°C for 8 weeks) high temperature exposure. High temperature challenges significantly elevated body temperature of experimental birds (Pshock transcription factors (HSFs) and heat shock proteins (HSPs) 70 and 90 were differently affected by acute and chronic treatment. Tissue-specific responses to thermal challenge were also found among heart, liver and muscle. In the heart, acute heat challenge affected lipid oxidation (P = 0.05) and gene expression of all 4 HSF gene expression was upregulated (Pstress increased protein oxidation, but HSFs and HSPs gene expression remained unaltered. Only tendencies to increase were observed in HSP 70 (P = 0.052) and 90 (P = 0.054) gene expression after acute heat stress. The differential expressions of HSF and HSP genes in different tissues of laying broiler breeder chickens suggested that anti-heat stress mechanisms might be provoked more profoundly in the heart, by which the muscle was least protected during heat stress. In addition to HSP, HSFs gene expression could be used as a marker during acute heat stress.

Experimental study of heat transfer in a transverse flow around the heat exchanger tubes bank by lead

International Nuclear Information System (INIS)

Berezin, A.N.; Grabezhnaya, V.A.; Mikheev, A.S.; Parfenov, A.S.

2014-01-01

The results of the work to determine the heat transfer coefficient in crossflow by lead of pipes are presented. The study was conducted at supercritical pressure in the water circuit. There was a significant inequality in the distribution of the heat flow in different rows of the bundle of heat exchange tubes of corridor location at crossflow their lead. The experimentally determined heat transfer coefficients from the lead differ substantially from those generally accepted recommendations for the calculation of heat transfer at cross flow of rod bundle by liquid metal. The experimental results are close to those obtained earlier on the model with cross flow of heat exchanger tubes bundle by lead alloy with bismuth [ru

Effect of heat input on heat affected zone cracking in laser welded ATI Allvac 718Plus superalloy

International Nuclear Information System (INIS)

Idowu, O.A.; Ojo, O.A.; Chaturvedi, M.C.

2007-01-01

The heat affected zones (HAZs) of low and high heat input laser welds of a newly developed superalloy, ATI Allvac 718Plus, were studied. Low heat input welds suffered significant HAZ grain boundary liquation cracking, while no cracking was observed in spite of a more extensive HAZ intergranular liquation in the higher heat input welds. Combination of lower welding stresses generated during cooling, and relaxation of these stresses by thick intergranular liquid were suggested to be the factors that contributed to the absence of cracking in the high heat input welds. Further, healing of some of the HAZ cracks in lower heat input welds by fusion zone interdendritic liquid occurred through liquid backfilling

Elevated [CO2] magnifies isoprene emissions under heat and improves thermal resistance in hybrid aspen

OpenAIRE

Sun, Zhihong; H?ve, Katja; Vislap, Vivian; Niinemets, ?lo

2013-01-01

Isoprene emissions importantly protect plants from heat stress, but the emissions become inhibited by instantaneous increase of [CO2], and it is currently unclear how isoprene-emitting plants cope with future more frequent and severe heat episodes under high [CO2]. Hybrid aspen (Populus tremula x Populus tremuloides) saplings grown under ambient [CO2] of 380 ?mol mol?1 and elevated [CO2] of 780 ?mol mol?1 were used to test the hypothesis that acclimation to elevated [CO2] reduces the inhibito...

Ohmic Heating Assisted Lye Peeling of Pears.

Science.gov (United States)

Gupta, Sarvesh; Sastry, Sudhir K

2018-05-01

Currently, high concentrations (15% to 18%) of lye (sodium hydroxide) are used in peeling pears, constituting a wastewater handling and disposal problem for fruit processors. In this study, the effect of ohmic heating on lye peeling of pears was investigated. Pears were peeled using 0.5%, 1%, 2%, and 3% NaOH under different electric field strengths at two run times and their peeled yields were compared to that obtained at 2% and 18% NaOH with conventional heating. Results revealed that ohmic heating results in greater than 95% peeled yields and the best peel quality at much lower concentrations of lye (2% NaOH at 532 V/m and 3% NaOH at 426 and 479 V/m) than those obtained under conventional heating conditions. Treatment times of 30 and 60 s showed no significant differences. Within the studied range, the effects of increasing field strength yielded no significant additional benefits. These results confirm that the concentration of lye can be significantly lowered in the presence of ohmic heating to achieve high peeled yields and quality. Our work shows that lye concentrations can be greatly reduced while peeling pears, resulting in significant savings in use of caustic chemicals, reduced costs for effluent treatment and waste disposal. © 2018 Institute of Food Technologists®.

Natural convection heat transfer coefficient for newborn baby - Thermal manikin assessed convective heat loses

Science.gov (United States)

Ostrowski, Ziemowit; Rojczyk, Marek

2017-11-01

The energy balance and heat exchange for newborn baby in radiant warmer environment are considered. The present study was performed to assess the body dry heat loss from an infant in radiant warmer, using copper cast anthropomorphic thermal manikin and controlled climate chamber laboratory setup. The total body dry heat losses were measured for varying manikin surface temperatures (nine levels between 32.5 °C and 40.1 °C) and ambient air temperatures (five levels between 23.5 °C and 29.7 °C). Radiant heat losses were estimated based on measured climate chamber wall temperatures. After subtracting radiant part, resulting convective heat loses were compared with computed ones (based on Nu correlations for common geometries). Simplified geometry of newborn baby was represented as: (a) single cylinder and (b) weighted sum of 5 cylinders and sphere. The predicted values are significantly overestimated relative to measured ones by: 28.8% (SD 23.5%) for (a) and 40.9% (SD 25.2%) for (b). This showed that use of adopted general purpose correlations for approximation of convective heat losses of newborn baby can lead to substantial errors. Hence, new Nu number correlating equation is proposed. The mean error introduced by proposed correlation was reduced to 1.4% (SD 11.97%), i.e. no significant overestimation. The thermal manikin appears to provide a precise method for the noninvasive assessment of thermal conditions in neonatal care.

Heat demand mapping and district heating grid expansion analysis: Case study of Velika Gorica

Directory of Open Access Journals (Sweden)

Dorotić Hrvoje

2017-01-01

Full Text Available Highly efficient cogeneration and district heating systems have a significant potential for primary energy savings and the reduction of greenhouse gas emissions through the utilization of a waste heat and renewable energy sources. These potentials are still highly underutilized in most European countries. They also play a key role in the planning of future energy systems due to their positive impact on the increase of integration of intermittent renewable energy sources, for example wind and solar in a combination with power to heat technologies. In order to ensure optimal levels of district heating penetration into an energy system, a comprehensive analysis is necessary to determine the actual demands and the potential energy supply. Economical analysis of the grid expansion by using the GIS based mapping methods hasn’t been demonstrated so far. This paper presents a heat demand mapping methodology and the use of its output for the district heating network expansion analysis. The result are showing that more than 59% of the heat demand could be covered by the district heating in the city of Velika Gorica, which is two times more than the present share. The most important reason of the district heating's unfulfilled potential is already existing natural gas infrastructure.

Heat demand mapping and district heating grid expansion analysis: Case study of Velika Gorica

Science.gov (United States)

Dorotić, Hrvoje; Novosel, Tomislav; Duić, Neven; Pukšec, Tomislav

2017-10-01

Highly efficient cogeneration and district heating systems have a significant potential for primary energy savings and the reduction of greenhouse gas emissions through the utilization of a waste heat and renewable energy sources. These potentials are still highly underutilized in most European countries. They also play a key role in the planning of future energy systems due to their positive impact on the increase of integration of intermittent renewable energy sources, for example wind and solar in a combination with power to heat technologies. In order to ensure optimal levels of district heating penetration into an energy system, a comprehensive analysis is necessary to determine the actual demands and the potential energy supply. Economical analysis of the grid expansion by using the GIS based mapping methods hasn't been demonstrated so far. This paper presents a heat demand mapping methodology and the use of its output for the district heating network expansion analysis. The result are showing that more than 59% of the heat demand could be covered by the district heating in the city of Velika Gorica, which is two times more than the present share. The most important reason of the district heating's unfulfilled potential is already existing natural gas infrastructure.

IL-10 is significantly involved in HSP70-regulation of experimental subretinal fibrosis.

Directory of Open Access Journals (Sweden)

Yang Yang

Full Text Available Subretinal fibrosis is directly related to severe visual loss, especially if occurs in the macula, and is frequently observed in advanced age-related macular degeneration and other refractory eye disorders such as diabetic retinopathy and uveitis. In this study, we analyzed the immunosuppressive mechanism of subretinal fibrosis using the novel animal model recently demonstrated. Both TLR2 and TLR4 deficient mice showed significant enlargement of subretinal fibrotic area as compared with wild-type mice. A single intraocular administration of heat shock protein 70 (HSP70, which is an endogenous ligand for TLR2 and TLR4, inhibited subretinal fibrosis in wild-type mice but not in TLR2 and TLR4-deficient mice. Additionally, HSP70 induced IL-10 production in eyes from wild-type mice but was impaired in both TLR2- and TLR4-deficient mice, indicating that HSP70-TLR2/TLR4 axis plays an immunomodulatory role in subretinal fibrosis. Thus, these results suggest that HSP70-TLR2/TLR4 axis is a new therapeutic target for subretinal fibrosis due to prognostic CNV.

Probing Conformational Change of Bovine Serum Albumin–Dextran Conjugates under Controlled Dry Heating

Energy Technology Data Exchange (ETDEWEB)

Xia, Shuqin; Li, Yunqi; Zhao, Qin; Li, Ji; Xia, Qiuyang; Zhang, Xiaoming; Huang, Qingrong (Rutgers); (Chinese Aca. Sci.); (Jiangnan)

2015-04-29

The time-dependent conformational change of bovine serum album (BSA) during Maillard reaction with dextran under controlled dry heating has been studied by small-angle X-ray scattering, fluorescence spectroscopy, dynamic light scattering, and circular dichroism analysis. Through the research on the radii of gyration (R_g), intrinsic fluorescence, and secondary structure, conjugates with dextran coating were found to inhibit BSA aggregation and preserve the secondary structure of native BSA against long-time heat treatment during Maillard reaction. The results suggested that the hydrophilic dextran was conjugated to the compact protein surface and enclosed it and more dextran chains were attached to BSA with the increase of the heating time. The study presented here will be beneficial to the understanding of the conformational evolution of BSA molecules during the dry-heating Maillard reaction and to the control of the protein–polysaccharide conjugate structure.

New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

International Nuclear Information System (INIS)

Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

2012-01-01

A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

Mechanical ventilation with heat recovery in cold climates

DEFF Research Database (Denmark)

Kragh, Jesper; Rose, Jørgen; Svendsen, Svend

2005-01-01

Building ventilation is necessary to achieve a healthy and comfortable indoor environment, but as energy prices continue to rise it is necessary to reduce the energy consumption. Using mechanical ventilation with heat recovery reduces the ventilation heat loss significantly, but in cold climates...... freezes to ice. The analysis of measurements from existing ventilation systems with heat recovery used in single-family houses in Denmark and a test of a standard heat recovery unit in the laboratory have clearly shown that this problem occurs when the outdoor temperature gets below approximately –5º......C. Due to the ice problem mechanical ventilation systems with heat recovery are often installed with an extra preheating system reducing the energy saving potential significantly. New designs of high efficient heat recovery units capable of continuously defrosting the ice without using extra energy...

Heating systems for heating subsurface formations

Science.gov (United States)

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

2011-04-26

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

Oxidative stress impairs the heat stress response and delays unfolded protein recovery.

Directory of Open Access Journals (Sweden)

Masaaki Adachi

2009-11-01

Full Text Available Environmental changes, air pollution and ozone depletion are increasing oxidative stress, and global warming threatens health by heat stress. We now face a high risk of simultaneous exposure to heat and oxidative stress. However, there have been few studies investigating their combined adverse effects on cell viability.Pretreatment of hydrogen peroxide (H(2O(2 specifically and highly sensitized cells to heat stress, and enhanced loss of mitochondrial membrane potential. H(2O(2 exposure impaired the HSP40/HSP70 induction as heat shock response (HSR and the unfolded protein recovery, and enhanced eIF2alpha phosphorylation and/or XBP1 splicing, land marks of ER stress. These H(2O(2-mediated effects mimicked enhanced heat sensitivity in HSF1 knockdown or knockout cells. Importantly, thermal preconditioning blocked H(2O(2-mediated inhibitory effects on refolding activity and rescued HSF1 +/+ MEFs, but neither blocked the effects nor rescued HSF1 -/- MEFs. These data strongly suggest that inhibition of HSR and refolding activity is crucial for H(2O(2-mediated enhanced heat sensitivity.H(2O(2 blocks HSR and refolding activity under heat stress, thereby leading to insufficient quality control and enhancing ER stress. These uncontrolled stress responses may enhance cell death. Our data thus highlight oxidative stress as a crucial factor affecting heat tolerance.

Heat pipe heat exchanger for heat recovery in air conditioning

Energy Technology Data Exchange (ETDEWEB)

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

2007-03-15

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

Inhibition of basophil histamine release by gangliosides. Further studies on the significance of cell membrane sialic acid in the histamine release process

DEFF Research Database (Denmark)

Jensen, C; Norn, S; Thastrup, Ole

1987-01-01

with the glucolipid mixture increased the sialic acid content of the cells, and this increase was attributed to an insertion of gangliosides into the cell membrane. The inhibition of histamine release was abolished by increasing the calcium concentration, which substantiates our previous findings that cell membrane......Histamine release from human basophils was inhibited by preincubation of the cells with a glucolipid mixture containing sialic acid-containing gangliosides. This was true for histamine release induced by anti-IgE, Concanavalin A and the calcium ionophore A23187, whereas the release induced by S....... aureus Wood 46 was not affected. It was demonstrated that the inhibitory capacity of the glucolipid mixture could be attributed to the content of gangliosides, since no inhibition was obtained with cerebrosides or with gangliosides from which sialic acid was removed. Preincubation of the cells...

Heating and current drive on NSTX

International Nuclear Information System (INIS)

Wilson, J.R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C.K.; Rogers, J.H.; Schilling, G.

1997-01-01

Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (∼45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation. copyright 1997 American Institute of Physics

The effect of ethylenediaminetetraacetic acid on heat resistance and recovery of Clostridium sporogenes PA 3679 spores treated in HTST conditions.

Science.gov (United States)

Silla Santos, M H; Torres Zarzo, J

1997-03-03

The effect of ethylenediaminetetraacetic acid (EDTA) on the heat resistance of Clostridium sporogenes PA 3679 spores was studied. EDTA was added to heating substrates and recovery media in order to establish which stage of the heat treatment registered the greatest EDTA activity. The heating substrates assayed were phosphate buffer (pH 7.0) and white asparagus purée, at natural pH (5.8) and acidified with citric acid and glucono-delta-lactone (GDL) to pH 5.5, 5.0 and 4.5. Recovery of survivors was carried out in MPA3679A medium in various conditions of acidification with citric and GDL (250 and 500 ppm), at pH 7.5 6.5 and 6.0. The results show greater activity of EDTA on spores when it was applied in recovery of heat injured spores, than during heating. The strongest influence of EDTA during heating was found in phosphate buffer (pH 7.0), with the effect being most evident at 121 and 126 degrees C, and in asparagus purée, at 121 degrees C and pH 5.8 rather than acidified. In recovery, the inhibiting activity of EDTA was more evident in spores subjected to more severe heat treatment, either by increasing the exposure time or by raising the temperature to 130 or 135 degrees C. The pH level of the recovery medium also affected the antimicrobial activity of EDTA, which had a greater inhibiting effect at pH 7.5 than at lower pH levels (6.5, 6.0).

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

Science.gov (United States)

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

2017-01-01

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

Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

Science.gov (United States)

Baars, Destiny L.; Pelegri, Francisco

2016-01-01

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole duplication, this method results in a precise cell division stall during the second cell cycle. The precise one-cycle division stall, coupled to unaffected DNA duplication, results in whole genome duplication. Protocols associated with this method include egg and sperm collection, UV treatment of sperm, in vitro fertilization and heat pulse to cause a one-cell cycle division delay and ploidy duplication. A modified version of this protocol could be applied to induce ploidy changes in other animal species. PMID:28060351

Heat transfer in two-phase flow of helium

International Nuclear Information System (INIS)

Subbotin, V.I.; Deev, V.I.; Solodovnikov, V.V.; Arkhipov, V.V.

1986-01-01

The results of experimental study of heat transfer in two-phase helium flow are presented. The effect of operating parameters (pressure, mass velocity, heat flux and quality) on boiling heat transfer intensity was investigated. A significant influence of boiling process prehistory on heat transfer coefficients was demonstrated. On the basis of experimental data obtained three typical regimes of flow boiling heat transfer were found. Analogy of heat transfer in flow boiling and pool boiling of helium and noncryogenic liquids was established. Correlations were developed which are in close agreement with available heat transfer data

Decentralized Heat Supply – Alternative to Centralized One

OpenAIRE

V. I. Nazarov; L. A. Tarasevich; А. L. Burov

2012-01-01

The paper presents a concrete example that shows comparative characteristics of decentralized and centralized heat supply. It has been shown in the paper that selection of this or that variant of heat supply significantly depends on losses in heat supply networks.

Kindergarteners’ Self-Reported Social Inhibition and Observed Social Reticence: Moderation by Adult-Reported Social Inhibition and Social Anxiety Disorder Symptoms

Science.gov (United States)

Kiel, Elizabeth J.; Buss, Kristin A.; Molitor, Joseph G.

2014-01-01

Prevention of later anxiety problems would best be accomplished by identifying at-risk children early in development. For example, children who develop Social Anxiety Disorder (SAD) may show social withdrawal in the form of social inhibition (i.e., shyness with unfamiliar adults and peers) at school entry. Although the use of children’s perceptions of their own social inhibition would provide insight into early risk, the utility of young children’s self-reports remains unclear. The current study examined whether children deemed more extreme on social inhibition or social anxiety by adult report provided self-report of social inhibition that related to observed social reticence in the laboratory. Participants included 85 kindergarten children (36 female, 49 male), their parents, and their teachers. Moderation analyses revealed that children’s self-reported social inhibition related significantly to observed social reticence under the conditions of high parent-reported social inhibition, high teacher-reported social inhibition, and high SAD symptoms. These results suggest that the most inhibited children are aware of their behavior and can report it in a meaningfully way as young as kindergarten age. PMID:25113397

Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice.

Science.gov (United States)

Ohno, Y; Egawa, T; Yokoyama, S; Nakai, A; Sugiura, T; Ohira, Y; Yoshioka, T; Goto, K

2015-12-01

Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated. Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia. Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle. Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Thermoregulatory responses to acute heat loads in rats following spontaneous running.

Science.gov (United States)

Sugimoto, N; Shido, O; Sakurada, S; Nagasaka, T

1999-02-01

Earlier studies showed that spontaneous exercise training in rodents shifted their core temperature and thermoeffector thresholds to high levels. The present study investigated heat loss and heat production responses to acute heat loads of exercise-trained rats. The exercise-trained rats were allowed to run in a running wheel freely for 6 months, while the sedentary controls were denied access to the wheel during the same period. Then, they were loosely restrained and put in a direct calorimeter. After thermal equilibrium had been attained, they were warmed for 30 min with an intraperitoneal electric heater (internal heating). At least 2 h later, the rats were externally warmed for 90 min by raising the ambient temperature from 24 to 38C (external warming). Hypothalamic temperature (Thy), evaporative and nonevaporative heat loss (R+C+K) and heat production were measured. Internal and external heating significantly increased Thy. During internal heating, the magnitude of the increase in Thy was significantly smaller and the amount of increase in (R+C+K) was significantly greater in the exercise-trained rats than in the controls. The slope showing the relationship between Thy and (R+C+K) in the trained rats was significantly steeper than that in the controls. During external warming, the magnitude of increase in Thy of the exercise-trained rats was significantly greater than that of the controls. The slope showing the relationship between Thy and (R+C+K) in the trained rats was not different from that in the controls. Changes in evaporative heat loss and heat production during the two types of heat load did not differ between the two groups. The results suggest that, in rats, exercise training with voluntary running improves heat tolerance through enhancing nonevaporative heat loss response. However, this may be the case only when the rats are subjected to a direct internal heat load.

Future heat supply of our cities. Heating by waste heat

Energy Technology Data Exchange (ETDEWEB)

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

1976-08-01

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

Natural convection heat transfer from a heated horizontal cylinder with Microencapsulated Phase-Change-Material slurries

International Nuclear Information System (INIS)

Kubo, Shinji; Akino, Norio; Tanaka, Amane; Nagashima, Akira

1998-01-01

The present study investigates natural convection heat transfer from a heated cylinder cooled by a water slurry of Microencapsulated Phase Change Material (MCPCM). A normal paraffin hydrocarbon with carbon number of 18 and melting point of 27.9degC, is microencapsulated by Melamine resin into particles of which average diameter is 9.5 μm and specific weight is same as water. The slurry of the MCPCM and water is put into a rectangular enclosure with a heated horizontal cylinder. The heat transfer coefficients of the cylinder were evaluated. Changing the concentrations of PCM and temperature difference between cylinder surface and working fluid. Addition of MCPCM into water, the heat transfer is enhanced significantly comparison with pure water in cases with phase change and is reduced slightly in cases without phase change. (author)

District heating versus local heating - Social supportability

International Nuclear Information System (INIS)

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

2004-01-01

business practices can be improved in district heating?; - Benefits and objectives of competition and privatization. A large number of DH systems in Romania face serious financial, marketing or technical problems. Uncompetitive tariffs and inadequate cost recovery have significantly damaged DH systems. This has a deeply negative impact on municipal budgets and on the viability of DH systems. 20% from the consumers disconnected from the DH systems for various reasons. The national reference tariff do not take into consideration the real economic performances of the DH systems. The lack of consumption control and consumption-based billing drive towards increasing the DH systems crisis. The consumers have to pay the technical, commercial and economic loses of the existing DH systems, so their supportability has continuously decreased. The Government offered every year important subsidies for DH companies, as well as social helps for the heating of the low income families. The real problem is to not spend the public founds covering the losses of some not viable DH systems, managed by state own companies/authorities instead of use this money to help the low income family to pay their contribution for the rehabilitation/construction of an efficient heating system. Gas versus district heating tariffs represents a key factor for everyone's decision to prefer district heating or local heating. The Government has the responsibility to inform the population regarding the future evolution on long term power, heat and gas tariffs in order to help the population to decide what is the most sustainable heating system. Systematic restructuring and investment in efficient technologies are essential for the actual DH systems. This could be made only by a legal/institutional reform which will create the environment for a commercial operations .There is necessary to create the framework for private sector participation stimulation. Only by improving the ownership/management structures could

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Heat savings and heat generation technologies: Modelling of residential investment behaviour with local health costs

International Nuclear Information System (INIS)

Zvingilaite, Erika; Klinge Jacobsen, Henrik

2015-01-01

The trade-off between investing in energy savings and investing in individual heating technologies with high investment and low variable costs in single family houses is modelled for a number of building and consumer categories in Denmark. For each group the private economic cost of providing heating comfort is minimised. The private solution may deviate from the socio-economical optimal solution and we suggest changes to policy to incentivise the individuals to make choices more in line with the socio-economic optimal mix of energy savings and technologies. The households can combine their primary heating source with secondary heating e.g. a woodstove. This choice results in increased indoor air pollution with fine particles causing health effects. We integrate health cost due to use of woodstoves into household optimisation of heating expenditures. The results show that due to a combination of low costs of primary fuel and low environmental performance of woodstoves today, included health costs lead to decreased use of secondary heating. Overall the interdependence of heat generation technology- and heat saving-choice is significant. The total optimal level of heat savings for private consumers decrease by 66% when all have the option to shift to the technology with lowest variable costs. - Highlights: • Heat saving investment and heat technology choice are interdependent. • Health damage costs should be included in private heating choice optimisation. • Flexibility in heating technology choice reduce the optimal level of saving investments. • Models of private and socioeconomic optimal heating produce different technology mix. • Rebound effects are moderate but varies greatly among consumer categories

Hydride heat pump with heat regenerator

Science.gov (United States)

Jones, Jack A. (Inventor)

1991-01-01

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

Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

DEFF Research Database (Denmark)

Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard

Heat shock proteins (HSPs) are highly conserved molecules, which support folding of proteins under physiological conditions and mediate protection against lethal damage after various stress stimuli. Five HSP families exist defined by their molecular size (i.e. HSP100, HSP90, HSP70, HSP60, and the......Heat shock proteins (HSPs) are highly conserved molecules, which support folding of proteins under physiological conditions and mediate protection against lethal damage after various stress stimuli. Five HSP families exist defined by their molecular size (i.e. HSP100, HSP90, HSP70, HSP60...... clinically applied reagents, such as alkyl-lysophospholipides, chemotherapeutic agents, and anti-inflammatory reagents, have been found to enhance Hsp70 surface expression on cancer cells. We have found that inhibition of histone deacetylase (HDAC) activity leads to surface expression of Hsp70 on various...... hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC-inhibitor mediated Hsp70 surface expression was confined to the apoptotic Annexin V positive cells and blocked by inhibition of apoptosis. Other chemotherapeutic inducers of apoptosis...

Polynomial regression analysis and significance test of the regression function

International Nuclear Information System (INIS)

Gao Zhengming; Zhao Juan; He Shengping

2012-01-01

In order to analyze the decay heating power of a certain radioactive isotope per kilogram with polynomial regression method, the paper firstly demonstrated the broad usage of polynomial function and deduced its parameters with ordinary least squares estimate. Then significance test method of polynomial regression function is derived considering the similarity between the polynomial regression model and the multivariable linear regression model. Finally, polynomial regression analysis and significance test of the polynomial function are done to the decay heating power of the iso tope per kilogram in accord with the authors' real work. (authors)

The dimethylthiourea-induced attenuation of cisplatin nephrotoxicity is associated with the augmented induction of heat shock proteins

International Nuclear Information System (INIS)

Tsuji, Takayuki; Kato, Akihiko; Yasuda, Hideo; Miyaji, Takehiko; Luo, Jinghui; Sakao, Yukitoshi; Ito, Hideaki; Fujigaki, Yoshihide; Hishida, Akira

2009-01-01

Dimethylthiourea (DMTU), a potent hydroxyl radical scavenger, affords protection against cisplatin (CDDP)-induced acute renal failure (ARF). Since the suppression of oxidative stress and the enhancement of heat shock proteins (HSPs) are both reported to protect against CDDP-induced renal damage, we tested whether increased HSP expression is involved in the underlying mechanisms of the DMTU-induced renal protection. We examined the effect of DMTU treatment on the expression of HSPs in the kidney until day 5 following a single injection of CDDP (5 mg/kg BW). DMTU significantly inhibited the CDDP-induced increments of serum creatinine, the number of 8-hydroxyl-2'-deoxyguanosine (8-OHdG)- and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL)-positive tubular cells, and tubular damage score (p < 0.05). CDDP significantly increased renal abundances of HO-1, HSP60, HSP72 and HSP90 at days 1, 3, and 5. DMTU significantly augmented only the expression of HSP60 expression mainly in the cytoplasm of the proximal tubular cells at days 1 and 3 in CDDP-induced ARF. DMTU also inhibited the CDDP-induced increment of Bax, a pro-apoptotic protein, in the fraction of organelles/membranes at day 3. The findings suggest that DMTU may afford protection against CDDP-induced ARF, partially through the early induction of cytoplasmic HSP60, thereby preventing the Bax-mediated apoptosis in renal tubular cells

Mapping of potential heat sources for heat pumps for district heating in Denmark

International Nuclear Information System (INIS)

Lund, Rasmus; Persson, Urban

2016-01-01

The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose. In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark. - Highlights: • The availability of heat sources for heat pumps in Denmark are mapped and quantified. • A novel methodology for assessment of low temperature industrial excess heat is presented. • There are heat sources available for 99% of district heating networks in Denmark. • The concentration of heat sources is generally bigger around bigger cities than smaller. • Ambient temperature heat sources will be more needed in district heating of big cities.

Heat pulse excitability of vestibular hair cells and afferent neurons.

Science.gov (United States)

Rabbitt, Richard D; Brichta, Alan M; Tabatabaee, Hessam; Boutros, Peter J; Ahn, JoongHo; Della Santina, Charles C; Poppi, Lauren A; Lim, Rebecca

2016-08-01

In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in protein biophysics and manipulate cellular excitability. Copyright © 2016 the American Physiological Society.

Use of bacillus subtilis strains to inhibit postharvest pathogenic fungi

International Nuclear Information System (INIS)

Arras, G.; Gambella, F.; Demontis, S.; Petretto, A.

1995-01-01

An isolate (87) of the bacillus subtilis strains isolated from cold stored citrus fruit 13 proved to inhibit the growth in vitro of the penicillium italicum used in the experiment (from 50.6% to 92.2%) and to inhibit botrytis cinerea (from 65.3% to 95.9%). A further test, superimposing on plates containing PDA strains Nos. 13, 173, and 160, totally inhibited the fungi. Tested in vivo on artificially bruised oranges, they significantly inhibited two fungi

Mathematical Model for the Sequential Action of Radiation and Heat on Yeast Cells

International Nuclear Information System (INIS)

Kim, Jin Kyu; Lee, Yun Jong; Kim, Su Hyoun; Nili, Mohammad; Zhurakovskaya, Galina P.; Petin, Vladislav G.

2009-01-01

It is well known that the synergistic interaction of hyperthermia with ionizing radiation and other agents is widely used in hyperthermic oncology. Interaction between two agents may be considered as synergistic or antagonistic when the effect produced is greater or smaller than the sum of the two single responses. It has long be considered that the mechanism of synergistic interaction of hyperthermia and ionizing radiation may be brought about by an inhibition of the repair from sublethal and potentially lethal damage at the cellular level. The inhibition of the recovery process after combined treatments cannot be considered as a reason for the synergy, but rather would be the expected and predicted consequence of the production of irreversible damage. On the basis of it, a simple mathematical model of the synergistic interaction of two agents acting simultaneously has been proposed. However, the model has not been applied to predict the degree of interaction of heat and ionizing radiation after their sequential action. Extension of the model to the sequential treatment of heat and ionizing radiation seems to be of interest for theoretical and practical reasons. Thus, the purposes of the present work is to suggest the simplest mathematical model which would be able to account for the results obtained and currently available experimental information on the sequential action of radiation and heat.

Cathepsin B is involved in the heat shock induced cardiomyocytes apoptosis as well as the anti-apoptosis effect of HSP-70.

Science.gov (United States)

Hsu, Shu-Fen; Hsu, Chuan-Chih; Cheng, Bor-Chih; Lin, Cheng-Hsien

2014-11-01

Cathepsin B is one of the major lysosomal cysteine proteases that plays an important role in apoptosis. Herein, we investigated whether Cathepsin B is involved in cardiomyocyte apoptosis caused by hyperthermic injury (HI) and heat shock protein (HSP)-70 protects these cells from HI-induced apoptosis mediated by Cathepsin. HI was produced in H9C2 cells by putting them in a circulating 43 °C water bath for 120 min, whereas preinduction of HSP-70 was produced in H9C2 cells by mild heat preconditioning (or putting them in 42 °C water bath for 30 min) 8 h before the start of HI. It was found that HI caused both cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. E-64-c, in addition to reducing Cathepsin B activity, significantly attenuated HI-induced cardiomyocyte apoptosis (evidenced by increased apoptotic cell numbers, increased tuncated Bid (t-Bid), increased cytochrome C, increased caspase-9/-3, and decreased Bcl-2/Bax) in H9C2 cells. In addition, preinduction of HSP-70 by mild heat preconditioning or inhibition of HSP-70 by Tripolide significantly attenuated or exacerbated respectively both the cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. Furthermore, the beneficial effects of pre-induction of HSP-70 by mild heat production in reducing both cardiomyocyte apoptosis and increased Cathepsin B activity caused by HI can be significantly reduced by Triptolide preconditioning. These results indicate that Cathepsin B is involved in HI-induced cardiomyocyte apoptosis in H9C2 cells and HSP-70 protects these cells from HI-induced cardiomyocyte apoptosis through Cathepsin B pathways.

Shivering and rewarming after cardiac surgery: comparison of ventilator circuits with humidifier and heated wires to heat and moisture exchangers.

Science.gov (United States)

McEvoy, M T; Carey, T J

1995-07-01

Detrimental physiologic effects of shivering in the cardiac surgery patient have been well documented. Rewarming techniques have been compared, with noted differences in the incidence of shivering. Ventilator circuits have not been examined independently from other rewarming variables. To compare heated wire humidification circuits with heat and moisture exchanger circuits on the incidence of shivering and speed and pattern of rewarming in mechanically ventilated patients. A prospective, descriptive, correlational study was done on 140 adult cardiac surgery patients in a university teaching medical center. All subjects underwent cardiac surgical procedures with hypothermic cardiopulmonary bypass. Subjects were randomized to humidified, heated wire circuits (n = 70) or heat and moisture exchanger circuits (n = 70). Heated water blankets were used on all patients. Mean intensive care unit admission temperature was 35.28 degrees C. No statistical differences were found in preoperative, demographic, or operative course data between treatment and control groups. Shivering was more common in the heat and moisture exchanger group than in the heated wire group. In our analysis, the only variable associated with shivering was the type of ventilator circuit. Patients using heated wire systems rewarmed more rapidly and had significantly higher temperatures than did patients using heat and moisture exchangers. These data suggest that use of heated wire humidified ventilator circuits with heated water blankets in adult cardiac surgery patients significantly reduces the incidence of shivering and results in a more rapid return to normothermia.

Below and above boiling point comparison of microwave irradiation and conductive heating for municipal sludge digestion under identical heating/cooling profiles.

Science.gov (United States)

Hosseini Koupaie, E; Eskicioglu, C

2015-01-01

This research provides a comprehensive comparison between microwave (MW) and conductive heating (CH) sludge pretreatments under identical heating/cooling profiles at below and above boiling point temperatures. Previous comparison studies were constrained to an uncontrolled or a single heating rate due to lack of a CH equipment simulating MW under identical thermal profiles. In this research, a novel custom-built pressure-sealed vessel which could simulate MW pretreatment under identical heating/cooling profiles was used for CH pretreatment. No statistically significant difference was proven between MW and CH pretreatments in terms of sludge solubilization, anaerobic biogas yield and organics biodegradation rate (p-value>0.05), while statistically significant effects of temperature and heating rate were observed (p-value<0.05). These results explain the contradictory results of previous studies in which only the final temperature (not heating/cooling rates) was controlled. Copyright © 2015 Elsevier Ltd. All rights reserved.

Decentralized Heat Supply – Alternative to Centralized One

Directory of Open Access Journals (Sweden)

V. I. Nazarov

2012-01-01

Full Text Available The paper presents a concrete example that shows comparative characteristics of decentralized and centralized heat supply. It has been shown in the paper that selection of this or that variant of heat supply significantly depends on losses in heat supply networks.

Ignited tokamak devices with ohmic-heating dominated startup

International Nuclear Information System (INIS)

Cohn, D.R.; Bromberg, L.; Jassby, D.L.

1986-01-01

Startup of tokamaks such that the auxiliary heating power is significantly less than the ohmic heating power at all times during heating to ignition can be referred to as ''Ohmic-heating dominated startup.'' Operation in this mode could increase the certainty of heating to ignition since energy confinement during startup may be described by present scaling laws for ohmic heating. It could also reduce substantially the auxiliary heating power (the required power may be quite large for auxiliary-heating dominated startup). These advantages might be realized without the potentially demanding requirements for pure ohmic heating to ignition. In this paper the authors discuss the requirements for ohmic-heating dominated startup and present illustrative design parameters for compact experiment ignition devices that use high performance copper magnets

Heat Pumps in CHP Systems

DEFF Research Database (Denmark)

Ommen, Torben Schmidt

that three configurations are particular advantageous, whereas the two remaining configurations result in system performance close to or below what may be expected from an electric heater. One of the three advantageous configurations is required to be positioned at the location of the heat demand, whereas...... the two remaining can be located at positions with availability of high temperature sources by utilising the DH network to distribute the heat. A large amount of operational and economic constraints limit the applicability of HPs operated with natural working fluids, which may be the only feasible choice...... representation allows infeasible production. Using MIP or NLP optimisation, the number of operation hours and the total production of heat from HPs are significantly increased, as the HPs may be used to shave the load patterns of CHP units in significantly constrained energy systems. A MIP energy system model...

Cutaneous noradrenaline measured by microdialysis in complex regional pain syndrome during whole-body cooling and heating

DEFF Research Database (Denmark)

Terkelsen, Astrid Juhl; Gierthmühlen, Janne; Petersen, Lars J.

2013-01-01

and in healthy volunteers. Seven patients and nine controls completed whole-body cooling (sympathetic activation) and heating (sympathetic inhibition) induced by a whole-body thermal suit with simultaneous measurement of the skin temperature, skin blood flow, and release of dermal noradrenaline. CRPS pain...

Heat transfer augmentation in a tube using nanofluids under constant heat flux boundary condition: A review

International Nuclear Information System (INIS)

Singh, Vinay; Gupta, Munish

2016-01-01

Highlights: • Reviews heat transfer augmentation of nanofluids in a tube with constant heat flux. • Recent advances in hybrid nanofluids are reviewed. • Identifies and compares significant results. • Scope of future research in this area is discussed. - Abstract: In the last few decades, research on nanofluids has increased rapidly. Traditional heat transfer fluids with order of nanometer sized particles (1–100 nm) suspended in them are termed as nanofluids. Nanofluids have been proved as better heat transfer fluids despite of various contradictions in results by different research groups. The aim of this article is to review and summarize the recent experimental and theoretical studies on convective heat transfer in heat exchangers using constant heat flux boundary condition. The use of different types of nanoparticles with different base fluids by different research groups has been presented and compared. Further an overview of experimental results about heat transfer abilities of hybrid nanofluids from available literature sources is also presented. Finally, the challenges and future directions in which research can be further progress are discussed.

Short-term heat shock affects the course of immune response in Galleria mellonella naturally infected with the entomopathogenic fungus Beauveria bassiana.

Science.gov (United States)

Vertyporokh, Lidiia; Taszłow, Paulina; Samorek-Pieróg, Małgorzata; Wojda, Iwona

2015-09-01

We aimed to investigate how exposition of infected insects to short-term heat shock affects the biochemical and molecular aspects of their immune response. Galleria mellonella larvae were exposed to 43°C for 15min, at the seventy second hour after natural infection with entomopathogenic fungus Beauveria bassiana. As a result, both qualitative and quantitative changes in hemolymph protein profiles, and among them infection-induced changes in the amount of apolipophorin III (apoLp-III), were observed. Heat shock differently affects the expression of the tested immune-related genes. It transiently inhibits expression of antifungal peptides gallerimycin and galiomicin in both the fat body and hemocytes of infected larvae. The same, although to a lesser extent, concerned apoLp-III gene expression and was observed directly after heat shock. Nevertheless, in larvae that had recovered from heat shock, apoLp-III expression was higher in comparison to unshocked larvae in the fat body but not in hemocytes, which was consistent with the higher amount of this protein detected in the hemolymph of the infected, shocked larvae. Furthermore, lysozyme-type activity was higher directly after heat shock, while antifungal activity was significantly higher also in larvae that had recovered from heat shock, in comparison to the respective values in their non-shocked, infected counterparts. These results show how changes in the external temperature modulate the immune response of G. mellonella suffering from infection with its natural pathogen B. bassiana. Copyright © 2015 Elsevier Inc. All rights reserved.

Experimental study on heat pipe heat removal capacity for passive cooling of spent fuel pool

International Nuclear Information System (INIS)

Xiong, Zhenqin; Wang, Minglu; Gu, Hanyang; Ye, Cheng

2015-01-01

Highlights: • A passively cooling SFP heat pipe with an 8.2 m high evaporator was tested. • Heat removed by the heat pipe is in the range of 3.1–16.8 kW. • The heat transfer coefficient of the evaporator is 214–414 W/m 2 /K. • The heat pipe performance is sensitive to the hot water temperature. - Abstract: A loop-type heat pipe system uses natural flow with no electrically driven components. Therefore, such a system was proposed to passively cool spent fuel pools during accidents to improve nuclear power station safety especially for station blackouts such as those in Fukushima. The heat pipe used for a spent fuel pool is large due to the spent fuel pool size. An experimental heat pipe test loop was developed to estimate its heat removal capacity from the spent fuel pool during an accident. The 7.6 m high evaporator is heated by hot water flowing vertically down in an assistant tube with a 207-mm inner diameter. R134a was used as the potential heat pipe working fluid. The liquid R134a level was 3.6 m. The tests were performed for water velocities from 0.7 to 2.1 × 10 −2 m/s with water temperatures from 50 to 90 °C and air velocities from 0.5 m/s to 2.5 m/s. The results indicate significant heat is removed by the heat pipe under conditions that may occur in the spent fuel pool

Ground Source Heat Supply in Moscow Oblast: Temperature Potential and Sustainable Depth of Heat Wells

Science.gov (United States)

Vasil'ev, G. P.; Gornov, V. F.; Dmitriev, A. N.; Kolesova, M. V.; Yurchenko, V. A.

2018-01-01

The paper is devoted to a problem of increasing the efficiency of low-potential geothermal heat in heat pump systems of residential buildings the Moscow oblast of Russia, including Moscow. Estimates of a natural geothermal potential in the Moscow oblast (based on climatological data for the period from 1982 to 2011) are presented and a "Typical climatic year of natural soil temperature variations for the geoclimatic conditions of the Moscow oblast, including the city of Moscow" is proposed. Numerical simulation of the influence of geothermal energy potential and the depth of heat wells on the efficiency of ground source heat pump systems for the heat supply of residential buildings is carried out. Analysis of the numerical simulation showed that the operation of a heat pump system in a house heating mode under the geoclimatic conditions of the Moscow oblast leads to a temperature drop of the heat-exchange medium circulating through heat wells to 5-6°C by the end of the first 10 years of operation, and the process stabilizes by the 15th year of operation, and further changes in the heat-exchange medium temperature do not any longer significantly affect the temperature of the heat-exchange medium in the heat well. In this case, the exact dependence of the heat-exchange medium temperature drop on the depth is not revealed. Data on the economically expedient heat well depth for the conditions of the Moscow oblast ensuring a net present value for the whole residential building life cycle are presented. It is found that the heat well depth of 60 m can be considered as an endpoint for the Moscow oblast, and a further heat well deepening is economically impractical.

A speculated cause of respiratory inhibition in infants.

Science.gov (United States)

Minowa, Hideki; Arai, Ikuyo; Yasuhara, Hajime; Ebisu, Reiko; Ohgitani, Ayako

2018-10-01

In our previous studies, we documented that threatened premature labor and asymmetrical intrauterine growth restriction were risk factors for respiratory inhibition. The goal of this study was to determine the cause of respiratory inhibition by considering perinatal risk factors. We examined 1497 infants with a gestational age of 36 weeks or greater. All infants were monitored using pulse oximetry and examined via cranial sonography. Respiratory inhibition was defined as severe hypoxemia caused by respiratory inhibition immediately after crying or gastroesophageal reflux or as a respiratory pause during feeding. We examined the relationships between respiratory inhibition and perinatal factors and speculated on the cause of respiratory inhibition. The median gestational age, birth weight, Apgar score at 1 min, and Apgar score at 5 min of the subjects were 38.9 weeks, 2930 g, 8.0 points, and 9.0 points, respectively. Respiratory inhibition was observed in 422 infants. Lateral ventricle enlargement and increased echogenicity in the ganglionic eminence were observed in 417 and 516 infants, respectively. Respiratory inhibition was significantly correlated with shorter gestational periods, twin pregnancies, lateral ventricle enlargement, and increased echogenicity in the ganglionic eminence. We speculate that umbilical cord compression is a major cause of respiratory inhibition.

Modeling and impacts of the latent heat of phase change and specific heat for phase change materials

Science.gov (United States)

Scoggin, J.; Khan, R. S.; Silva, H.; Gokirmak, A.

2018-05-01

We model the latent heats of crystallization and fusion in phase change materials with a unified latent heat of phase change, ensuring energy conservation by coupling the heat of phase change with amorphous and crystalline specific heats. We demonstrate the model with 2-D finite element simulations of Ge2Sb2Te5 and find that the heat of phase change increases local temperature up to 180 K in 300 nm × 300 nm structures during crystallization, significantly impacting grain distributions. We also show in electrothermal simulations of 45 nm confined and 10 nm mushroom cells that the higher amorphous specific heat predicted by this model increases nucleation probability at the end of reset operations. These nuclei can decrease set time, leading to variability, as demonstrated for the mushroom cell.

Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets

Energy Technology Data Exchange (ETDEWEB)

Lawson, Michael J.; Thole, Karen A. [Mechanical and Nuclear Engineering Department, The Pennsylvania State University, University Park, PA 16802 (United States)

2008-05-15

Delta winglets are known to induce the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which the winglets are placed. This study investigates the use of delta winglets to augment heat transfer on the tube surface of louvered fin heat exchangers. It is shown that delta winglets placed on louvered fins produce augmentations in heat transfer along the tube wall as high as 47% with a corresponding increase of 19% in pressure losses. Manufacturing constraints are considered in this study whereby piercings in the louvered fins resulting from stamping the winglets into the louvered fins are simulated. Comparisons of measured heat transfer coefficients with and without piercings indicate that piercings reduce average heat transfer augmentations, but significant increases still occur with respect to no winglets present. (author)

Effects of anthropogenic heat due to air-conditioning systems on an extreme high temperature event in Hong Kong

Science.gov (United States)

Wang, Y.; Li, Y.; Di Sabatino, S.; Martilli, A.; Chan, P. W.

2018-03-01

Anthropogenic heat flux is the heat generated by human activities in the urban canopy layer, which is considered the main contributor to the urban heat island (UHI). The UHI can in turn increase the use and energy consumption of air-conditioning systems. In this study, two effective methods for water-cooling air-conditioning systems in non-domestic areas, including the direct cooling system and central piped cooling towers (CPCTs), are physically based, parameterized, and implemented in a weather research and forecasting model at the city scale of Hong Kong. An extreme high temperature event (June 23-28, 2016) in the urban areas was examined, and we assessed the effects on the surface thermal environment, the interaction of sea-land breeze circulation and urban heat island circulation, boundary layer dynamics, and a possible reduction of energy consumption. The results showed that both water-cooled air-conditioning systems could reduce the 2 m air temperature by around 0.5 °C-0.8 °C during the daytime, and around 1.5 °C around 7:00-8:00 pm when the planetary boundary layer (PBL) height was confined to a few hundred meters. The CPCT contributed around 80%-90% latent heat flux and significantly increased the water vapor mixing ratio in the atmosphere by around 0.29 g kg-1 on average. The implementation of the two alternative air-conditioning systems could modify the heat and momentum of turbulence, which inhibited the evolution of the PBL height (a reduction of 100-150 m), reduced the vertical mixing, presented lower horizontal wind speed and buoyant production of turbulent kinetic energy, and reduced the strength of sea breeze and UHI circulation, which in turn affected the removal of air pollutants. Moreover, the two alternative air-conditioning systems could significantly reduce the energy consumption by around 30% during extreme high temperature events. The results of this study suggest potential UHI mitigation strategies and can be extended to

Assessment of ASME code examinations on regenerative, letdown and residual heat removal heat exchangers

International Nuclear Information System (INIS)

Gosselin, Stephen R.; Cumblidge, Stephen E.; Anderson, Michael T.; Simonen, Fredric A.; Tinsley, G A.; Lydell, B.; Doctor, Steven R.

2005-01-01

Inservice inspection requirements for pressure retaining welds in the regenerative, letdown, and residual heat removal heat exchangers are prescribed in Section XI Articles IWB and IWC of the ASME Boiler and Pressure Vessel Code. Accordingly, volumetric and/or surface examinations are performed on heat exchanger shell, head, nozzle-to-head, and nozzle-to-shell welds. Inspection difficulties associated with the implementation of these Code-required examinations have forced operating nuclear power plants to seek relief from the U.S. Nuclear Regulatory Commission. The nature of these relief requests are generally concerned with metallurgical, geometry, accessibility, and radiation burden. Over 60% of licensee requests to the NRC identify significant radiation exposure burden as the principle reason for relief from the ASME Code examinations on regenerative heat exchangers. For the residual heat removal heat exchangers, 90% of the relief requests are associated with geometry and accessibility concerns. Pacific Northwest National Laboratory was funded by the NRC Office of Nuclear Regulatory Research to review current practice with regard to volumetric and/or surface examinations of shell welds of letdown heat exchangers regenerative heat exchangers and residual (decay) heat removal heat exchangers Design, operating, common preventative maintenance practices, and potential degradation mechanisms are reviewed. A detailed survey of domestic and international PWR-specific operating experience was performed to identify pressure boundary failures (or lack of failures) in each heat exchanger type and NSSS design. The service data survey was based on the PIPExp- database and covers PWR plants worldwide for the period 1970-2004. Finally a risk assessment of the current ASME Code inspection requirements for residual heat removal, letdown, and regenerative heat exchangers is performed. The results are then reviewed to discuss the examinations relative to plant safety and

Pulmonary surfactant and its components inhibit secretion of phosphatidylcholine from cultured rat alveolar type II cells

International Nuclear Information System (INIS)

Dobbs, L.G.; Wright, J.R.; Hawgood, S.; Gonzalez, R.; Venstrom, K.; Nellenbogen, J.

1987-01-01

Pulmonary surfactant is synthesized and secreted by alveolar type II cells. Radioactive phosphatidylcholine has been used as a marker for surfactant secretion. The authors report findings that suggest that surfactant inhibits secretion of 3 H-labeled phosphatidylcholine by cultured rat type II cells. The lipid components and the surfactant protein group of M/sub r/ 26,000-36,000 (SP 26-36) inhibit secretion to different extents. Surfactant lipids do not completely inhibit release; in concentrations of 100 μg/ml, lipids inhibit stimulated secretion by 40%. SP 26-36 inhibits release with an EC 50 of 0.1 μg/ml. At concentrations of 1.0 μg/ml, SP 26-36 inhibits basal secretion and reduces to basal levels secretion stimulated by terbutaline, phorbol 12-myristate 13-acetate, and the ionophore A23187. The inhibitory effect of SP 26-36 can be blocked by washing type II cells after adding SP 26-36, by heating the proteins to 100 0 C for 10 min, by adding antiserum specific to SP 26-36, or by incubating cells in the presence of 0.2 mM EGTA. SP 26-36 isolated from canine and human sources also inhibits phosphatidylcholine release from rat type II cells. Neither type I collagen nor serum apolipoprotein A-1 inhibits secretion. These findings are compatible with the hypothesis that surfactant secretion is under feedback regulatory control

Enhancement of heat dissipation of LED module with cupric-oxide composite coating on aluminum-alloy heat sink

International Nuclear Information System (INIS)

Kim, Donghyun; Lee, Junghoon; Kim, Junho; Choi, Chang-Hwan; Chung, Wonsub

2015-01-01

Highlights: • We fabricate the CuO/resin composite coating layer on aluminum alloy heat sink. • CuO/resin coating considerably improved the surface emissivity. • The LED junction temperature was reduced by CuO/resin coated heat sink. • The thermal resistance of heat sink was decreased by CuO/resin composite coating at 200 μm thickness. - Abstract: A composite coating composed of cupric oxide (CuO) and silicon-based resin was applied to an aluminum-alloy heat sink for a light emitting diode (LED) module. The purpose of the composite coating is to improve the heat dissipation performance of heat sink by enhancing thermal radiation emission. The heat dissipation performance was investigated in terms of LED junction temperature and thermal resistance using a thermal transient method. The CuO and silicon-based resin composite coating showed higher emissivity, and the lower junction temperature and thermal resistance of the heat sink was achieved. In addition, a continuous operation test of the LED chip with the heat sink revealed that the surface treated with the CuO composite coating stably dissipated heat without degradation. In conclusion, the composite coating proposed here showed a significant improvement of the heat dissipation performance of the aluminum-alloy heat sink due to the enhanced thermal radiation property.

Convective heat transfer measurements in a vapour-liquid-liquid three-phase direct contact heat exchanger

Science.gov (United States)

Mahood, Hameed B.; Campbell, A. N.; Baqir, Ali Sh.; Sharif, A. O.; Thorpe, R. B.

2017-12-01

Energy usage is increasing around the world due to the continued development of technology, and population growth. Solar energy is a promising low-grade energy resource that can be harvested and utilised in different applications, such solar heater systems, which are used in both domestic and industrial settings. However, the implementation of an efficient energy conversion system or heat exchanger would enhance such low-grade energy processes. The direct contact heat exchanger could be the right choice due to its ability to efficiently transfer significant amounts of heat, simple design, and low cost. In this work, the heat transfer associated with the direct contact condensation of pentane vapour bubbles in a three-phase direct contact condenser is investigated experimentally. Such a condenser could be used in a cycle with a solar water heater and heat recovery systems. The experiments on the steady state operation of the three-phase direct contact condenser were carried out using a short Perspex tube of 70 cm in total height and an internal diameter of 4 cm. Only a height of 48 cm was active as the direct contact condenser. Pentane vapour, (the dispersed phase) with three different initial temperatures (40° C, 43.5° C and 47.5° C) was directly contacted with water (the continuous phase) at 19° C. The experimental results showed that the total heat transfer rate per unit volume along the direct contact condenser gradually decreased upon moving higher up the condenser. Additionally, the heat transfer rate increases with increasing mass flow rate ratio, but no significant effect on the heat transfer rate of varying the initial temperature of the dispersed phase was seen. Furthermore, both the outlet temperature of the continuous phase and the void fraction were positively correlated with the total heat transfer rate per unit volume, with no considerable effect of the initial temperature difference between the dispersed and continuous phases.

Convective heat transfer measurements in a vapour-liquid-liquid three-phase direct contact heat exchanger

Science.gov (United States)

Mahood, Hameed B.; Campbell, A. N.; Baqir, Ali Sh.; Sharif, A. O.; Thorpe, R. B.

2018-06-01

Energy usage is increasing around the world due to the continued development of technology, and population growth. Solar energy is a promising low-grade energy resource that can be harvested and utilised in different applications, such solar heater systems, which are used in both domestic and industrial settings. However, the implementation of an efficient energy conversion system or heat exchanger would enhance such low-grade energy processes. The direct contact heat exchanger could be the right choice due to its ability to efficiently transfer significant amounts of heat, simple design, and low cost. In this work, the heat transfer associated with the direct contact condensation of pentane vapour bubbles in a three-phase direct contact condenser is investigated experimentally. Such a condenser could be used in a cycle with a solar water heater and heat recovery systems. The experiments on the steady state operation of the three-phase direct contact condenser were carried out using a short Perspex tube of 70 cm in total height and an internal diameter of 4 cm. Only a height of 48 cm was active as the direct contact condenser. Pentane vapour, (the dispersed phase) with three different initial temperatures (40° C, 43.5° C and 47.5° C) was directly contacted with water (the continuous phase) at 19° C. The experimental results showed that the total heat transfer rate per unit volume along the direct contact condenser gradually decreased upon moving higher up the condenser. Additionally, the heat transfer rate increases with increasing mass flow rate ratio, but no significant effect on the heat transfer rate of varying the initial temperature of the dispersed phase was seen. Furthermore, both the outlet temperature of the continuous phase and the void fraction were positively correlated with the total heat transfer rate per unit volume, with no considerable effect of the initial temperature difference between the dispersed and continuous phases.

Use and groundwater risk potential of additives in heat transfer fluids for borehole heat exchangers

International Nuclear Information System (INIS)

Ilieva, Dafina

2014-01-01

glycol. A significant degradation of the antifreeze agent coupled on sulfate-reduction was observed in experiments with sandstone-sediment. Benzotriazoles were highly persistent under sulfate- and nitrate-reducing as well as fermentative conditions. Under aerobic and iron-reducing conditions a partial decrease (up to 30 %) in the concentration of benzotriazoles (tolyltriazole was not degraded under aerobic conditions) was observed within 88 and 243 days of incubation respectively. At the same time an unknown transformation product was detected. Aerobic experiments with Rhodococcus pyridinovorans showed no cometabolic biodegradation of benzotriazole. Benzotriazoles caused longer lag-phases and slower biodegradation rates of ethylene glycol under nitrate- and sulfate-reducing conditions. Furthermore, an accumulation of acetaldehyde (intermediate in the fermentation of ethylene glycol) was observed in the presence of benzotriazoles. The experiments with a mixture of benzoate, decane and dodecane dicarboxyltaes showed a complete biodegradation of the acids under aerobic conditions. Nitratereducing bacteria utilized the two dicarboxyltaes but no benzoate. All three substances were persistent under fermentative, iron- and sulfate-reducing conditions. 2- ethylhexanoate was utilized as the sole organic substrate in microsoms, where nitrate or sulfate was added as the electron acceptor. No decrease in the concentration of 2- ethylhexanoate was observed under iron-reducing conditions. No effect of the carbonates on the biodegradation of ethylene glycol could be observed. Benzotriazoles present a potential risk for deep groundwater aquifers due to their persistence under different redox conditions. These corrosion inhibitors may not only threaten groundwater quality due to their own recalcitrance but in addition inhibit the biodegradation of other organic compounds. Further, the application of the investigated organic acids (except 2-Ethylhexanoate) should be reconsidered. Because

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 ...

Anxiety and retrieval inhibition: support for an enhanced inhibition account.

Science.gov (United States)

Nuñez, Mia; Gregory, Josh; Zinbarg, Richard E

2017-02-01

Retrieval inhibition of negative associations is important for exposure therapy for anxiety, but the relationship between memory inhibition and anxiety is not well understood-anxiety could either be associated with enhanced or deficient inhibition. The present study tested these two competing hypotheses by measuring retrieval inhibition of negative stimuli by related neutral stimuli. Non-clinically anxious undergraduates completed measures of trait and state anxiety and completed a retrieval induced forgetting task. Adaptive forgetting varied with state anxiety. Low levels of state anxiety were associated with no evidence for retrieval inhibition for either threatening or non-threatening categories. Participants in the middle tertile of state anxiety scores exhibited retrieval inhibition for non-threatening categories but not for threatening categories. Participants in the highest tertile of state anxiety, however, exhibited retrieval inhibition for both threatening and non-threatening categories with the magnitude of retrieval inhibition being greater for threatening than non-threatening categories. The data are in line with the avoidance aspect of the vigilance-avoidance theory of anxiety and inhibition. Implications for cognitive behavioural therapy practices are discussed.

Targeting the maximum heat recovery for systems with heat losses and heat gains

International Nuclear Information System (INIS)

Wan Alwi, Sharifah Rafidah; Lee, Carmen Kar Mun; Lee, Kim Yau; Abd Manan, Zainuddin; Fraser, Duncan M.

2014-01-01

Graphical abstract: Illustration of heat gains and losses from process streams. - Highlights: • Maximising energy savings through heat losses or gains. • Identifying location where insulation can be avoided. • Heuristics to maximise heat losses or gains. • Targeting heat losses or gains using the extended STEP technique and HEAT diagram. - Abstract: Process Integration using the Pinch Analysis technique has been widely used as a tool for the optimal design of heat exchanger networks (HENs). The Composite Curves and the Stream Temperature versus Enthalpy Plot (STEP) are among the graphical tools used to target the maximum heat recovery for a HEN. However, these tools assume that heat losses and heat gains are negligible. This work presents an approach that considers heat losses and heat gains during the establishment of the minimum utility targets. The STEP method, which is plotted based on the individual, as opposed to the composite streams, has been extended to consider the effect of heat losses and heat gains during stream matching. Several rules to guide the proper location of pipe insulation, and the appropriate procedure for stream shifting have been introduced in order to minimise the heat losses and maximise the heat gains. Application of the method on two case studies shows that considering heat losses and heat gains yield more realistic utility targets and help reduce both the insulation capital cost and utility cost of a HEN

Experimental investigation and feasibility analysis on a capillary radiant heating system based on solar and air source heat pump dual heat source

International Nuclear Information System (INIS)

Zhao, M.; Gu, Z.L.; Kang, W.B.; Liu, X.; Zhang, L.Y.; Jin, L.W.; Zhang, Q.L.

2017-01-01

Graphical abstract: (a) Vertical temperature gradient in Case 3, (b) PMV and PPD of the test room in Case 3, (c) operating time of SPCTS and ASHP systems in Case 3 and (d) the proportion of SPCTS operating time. - Highlights: • A capillary heating system based on solar and air source heat pump was developed. • Influence of supply water temperature on solar energy saving rate was investigated. • Heating performance and thermal comfort of capillary heating system were analyzed. • Low temperature heating with capillary is suitable for solar heating system. - Abstract: Due to sustainable development, solar energy has drawn much attention and been widely applied in buildings. However, the application of solar energy is limited because of its instability, intermittency and low energy density in winter. In order to use low density and instable solar energy source for heating and improve the utilization efficiency of solar energy, a solar phase change thermal storage (SPCTS) heating system using a radiant-capillary-terminal (RCT) to effectively match the low temperature hot water, a phase change thermal storage (PCTS) to store and continuously utilize the solar energy, and an air source heat pump (ASHP) as an alternate energy, was proposed and set up in this research. Series of experiments were conducted to obtain the relation between the solar radiation utilization rate and the heating supply temperatures, and to evaluate the performance of the RCT module and the indoor thermal environment of the system for its practical application in a residential building in the north-western City of Xi’an, China. The results show that energy saving of the solar heating system can be significantly improved by reducing the supplied water temperature, and the supplied water temperature of the RCT would be no more than 35 °C. The capillary radiation heating can adopt a lower water temperature and create a good thermal comfort environment as well. These results may lead to the

Heating networks and domestic central heating systems

Energy Technology Data Exchange (ETDEWEB)

Kamler, W; Wasilewski, W

1976-08-01

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

Modelling of Ammonia Heat Pump Desuperheaters

DEFF Research Database (Denmark)

Christensen, Stefan Wuust; Elmegaard, Brian; Markussen, Wiebke Brix

2015-01-01

This paper presents a study of modelling desuperheating in ammonia heat pumps. Focus is on the temperature profile of the superheated refrigerant. Typically, the surface area of a heat exchanger is estimated using the Log Mean Temperature Difference (LMTD) method. The assumption of this method...... is that the specific heat is constant throughout the temperature glide of the refrigerant in the heat exchanger. However, considering ammonia as refrigerant, the LMTD method does not give accurate results due to significant variations of the specific heat. By comparing the actual temperature profiles from a one....... The area of the heat exchanger can be increased or the condensation temperature can be raised to achieve the same temperature difference for the discretized model as for the LMTD. This would affect the compressor work, hence the COP of the system. Furthermore, for higher condenser pressure, and thus higher...

Thermoeconomic comparison of industrial heat pumps

DEFF Research Database (Denmark)

Ommen, Torben Schmidt; Markussen, Christen Malte; Reinholdt, L.

2011-01-01

Four natural working fluids in various heat pump cycles are expected to cover the heating range between 50oC and 150°C. The different thermodynamic cycles are the Condensing Vapour, Transcritical and Compression/Absorption. As the considered technologies have significant differences in application......, limitations and design, a generic comparison is used. To establish the optimal individual temperature range of operation, a thermoeconomic evaluation is performed, with heat price as the decision parameter. Each individual heat pump is favourable in specific temperature intervals, which will vary according...... to the temperature lift between sink and source. At temperature lifts below 30°C the entire temperature range is covered. Exceeding this temperature lift, the range of sink temperatures is not completely covered above 125°C. Three of the heat pumps prove very cost competitive when compared to heating with natural...

Heat transfer and critical heat flux in a asymmetrically heated tube helicoidal flow

International Nuclear Information System (INIS)

Boscary, J.

1995-10-01

The design of plasma facing components is crucial for plasma performance in next fusion reactors. These elements will be submitted to very high heat flux. They will be actively water-cooled by swirl tubes in the subcooled boiling regime. High heat flux experiments were conducted in order to analyse the heat transfer and to evaluate the critical heat flux. Water-cooled mock-ups were one-side heated by an electron beam gun for different thermal-hydraulic conditions. The critical heat flux was detected by an original method based on the isotherm modification on the heated surface. The wall heat transfer law including forced convection and subcooled boiling regimes was established. Numerical calculations of the material heat transfer conduction allowed the non-homogeneous distribution of the wall temperature and of the wall heat flux to be evaluated. The critical heat flux value was defined as the wall maximum heat flux. A critical heat flux model based on the liquid sublayer dryout under a vapor blanket was established. A good agreement with test results was found. (author). 198 refs., 126 figs., 21 tabs

Local total and radiative heat-transfer coefficients during the heat treatment of a workpiece in a fluidised bed

International Nuclear Information System (INIS)

Gao, W.M.; Kong, L.X.; Hodgson, P.D.

2006-01-01

The heat-transfer coefficients around a workpiece immersed in an electrically heated heat treatment fluidised bed were studied. A suspension probe designed to simulate a workpiece of complex geometry was developed to measure local total and radiative heat-transfer coefficients at a high bed temperature. The probe consisted of an energy-storage region separated by insulation from the fluidised bed, except for the measuring surface, and a multi-thermocouple measurement system. Experiments in the fluidised bed were performed for a fluidising medium of 120-mesh alumina, a wide temperature range of 110-1050 deg. C and a fluidising number range of 1.18-4.24. It was found that the workpiece surface temperature has a more significant effect on heat transfer than the bed temperature. The total heat-transfer coefficient at the upper surface of the workpiece sharply decreased at the start of heating, and then steadily increased as heating progressed, while a sharp decrease became a rapid increase and then a slow increase for the radiative heat-transfer coefficient. A great difference in the heat-transfer coefficients around the workpiece was observed

Interpretation of lunar heat flow data

International Nuclear Information System (INIS)

Conel, J.E.; Morton, J.B.

1975-01-01

Lunar heat flow observations at the Apollo 15 and 17 sites can be interpreted to imply bulk U concentrations for the Moon of 5 to 8 times those of normal chondrites and 2 to 4 times terrestrial values inferred from the Earth's heat flow and the assumption of thermal steady state between surface heat flow and heat production. A simple model of nearsurface structure that takes into account the large difference in (highly insulating) regolith thickness between mare and highland provinces is considered. This model predicts atypically high local values of heat flow near the margins of mare regions--possibly a factor of 10 or so higher than the global average. A test of the proposed model using multifrequency microwave techniques appears possible wherein heat flow traverse measurements are made across mare-highland contacts. The theoretical considerations discussed here urge caution in attributing global significance to point heat-flow measurements on the Moon

Heating experiments of JT-60

International Nuclear Information System (INIS)

1987-01-01

In JT-60, after the finish of the first stage Joule experiment, the heating facilities were installed, and the heating experiment was started in August, 1986. As to neutral beam injection, the beam injection experiment at the maximum rating 20 MW carried out, and also as to RF, the injection experiment up to 1.4 MW was carried out in both ion cyclotron and low band hybrid waves. The results worthy of special mention in the heating experiment were the success in the current drive up to 1.7 MA at maximum using low band hybrid waves and the improvement of plasma confinement characteristics obtained by the compound heating of NBI and RF. In this paper, the main results of these heating experiments and their significance are explained. The JT-60 is the testing facilities for attaining the critical plasma condition by additionally heating the plasma which is generated by Joule electric discharge with NBI and RF heatings. The experimental operation cycle of the JT-60 consists of the unit cycle of two weeks, and the number of days in operation is nine days. The temperature of heated plasma rose to 70 million deg C in the 20 MW NBI heating. Hereafter, the improvement of confinement time by increasing the stored energy of plasma is attempted. (Kako, I.)

Wind power integration with heat pumps, heat storages, and electric vehicles - Energy systems analysis and modelling

Energy Technology Data Exchange (ETDEWEB)

Hedegaard, K.

2013-09-15

Denmark by about 300-600 MW, corresponding to the size of a large power plant. This can be achieved when investing in socio-economically feasible heat storages complementing the heat pumps. The potential for reducing the required investments in peak/reserve capacities is crucial for the feasibility of the heat storages. Intelligent heat storage in the building structure is identified as socio-economically feasible in 20-75 % of the houses with heat pump installations, depending on the cost of control equipment in particular. Investment in control equipment, enabling utilisation of existing hot water tanks for flexible heat pump operation, is found socio-economically feasible in about 20-70 % of the houses. In contrast, heat accumulation tanks are not competitive, due to their higher investments costs. Further analyses investigate the system effects of a gradual large-scale implementation of battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs) in Denmark, Finland, Norway, Sweden, and Germany towards 2030. When charged/discharged intelligently, the electric vehicles can, in the long term, facilitate larger wind power investments, while they in the short term in many cases are likely to result in increased coal-based electricity generation. The electric vehicles can contribute significantly to reducing CO{sub 2} emissions, while system costs are generally increased, due to assumed investments in the costly BEVs. The need for peak/reserve capacities can be reduced through the use of vehicle-to-grid capability. Competing flexibility measures, such as large heat pumps, electric boilers, and thermal storages in the district heating system, have also been included in the energy systems analyses. These technologies can together facilitate increased wind power investments and reduce CO{sub 2} emissions in the same order of magnitude as a large-scale implementation of electric vehicles. Overall, it is concluded that individual heat pumps, flexibility

Industrial excess heat for district heating in Denmark

International Nuclear Information System (INIS)

Bühler, Fabian; Petrović, Stefan; Karlsson, Kenneth; Elmegaard, Brian

2017-01-01

Highlights: •Method for utilisation potential of industrial excess heat for district heating. •Industrial excess heat from thermal processes is quantified at single production units. •Linking of industrial excess heat sources and district heating demands done in GIS. •Excess heat recovery using direct heat transfer and heat pumps. •5.1% of the Danish district heating demand could be supplied by industrial excess heat. -- Abstract: Excess heat is available from various sources and its utilisation could reduce the primary energy use. The accessibility of this heat is however dependent amongst others on the source and sink temperature, amount and potential users in its vicinity. In this work a new method is developed which analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal processes which equals 5.1% of the current demand. More than half of this heat was found to be usable directly, without the need for a heat pump.

Heat stress and recovery of photosystem II efficiency in wheat (Triticum aestivum L.) cultivars acclimated to different growth temperatures

DEFF Research Database (Denmark)

Haque, Sabibul; Kjær, Katrine Heinsvig; Rosenqvist, Eva

2014-01-01

The effect of heat stress on photosystem II (PS II) efficiency and post-stress recovery was studied in four wheat cultivars using chlorophyll fluorescence. The main aim was to examine the cultivar differences in relation to inhibition and recovery of PSII functionality after heat stress...... and 25 °C) and subjected to heat stress (40 °C) for two days at early tillering and three days at anthesis and early grain development stages. The plants were returned to their original growth conditions after heat stress and recovery was observed for three days. The maximum photochemical efficiency (Fv...... heat tolerance characteristics as compared to the other three cultivars. The largest decrease in Fv/Fm and F′q/F′m after heat stress occurred in the cultivar PWS7, which did not recover completely after 72 h. All cultivars grown at 25 °C had a slightly increased heat tolerance and better recovery...

Temperature and duration of heating of sunflower oil affect ruminal biohydrogenation of linoleic acid in vitro

OpenAIRE

Privé , Florence; Combes, Sylvie; Cauquil, Laurent; Farizon, Yves; Enjalbert, Francis; Troegeler-Meynadier, Annabelle

2010-01-01

Sunflower oil heated at 110 or 150°C for 1, 3, or 6 h was incubated with ruminal content in order to investigate the effects of temperature and duration of heating of oil on the ruminal biohydrogenation of linoleic acid in vitro. When increased, these 2 parameters acted together to decrease the disappearance of linoleic acid in the media by inhibiting the isomerization of linoleic acid, which led to a decrease in conjugated linoleic acids and trans-C18:1 production. Nevertheless, trans-10 iso...

New infrared-assisted method for sol-gel derived ZnO:Ag thin films: Structural and bacterial inhibition properties.

Science.gov (United States)

González-Penguelly, Brenely; Morales-Ramírez, Ángel de Jesús; Rodríguez-Rosales, Miriam Guadalupe; Rodríguez-Nava, Celestino Odín; Carrera-Jota, María Luz

2017-09-01

A new sol-gel method, based on crystallization with Infrared heating, was developed to obtain ZnO:Ag thin films. The common sol, with zinc acetate as precursor and silver nitrate as doping source (1, 3 and 5 % molar), isopropanol and distilled water as solvents and monoethanolamine as stabilizer agent; was modified with Pluronic F127 and diethylene glycol as rheological agents, and with urea as fuel to produce enough energy to the combustion and to promote the crystallization process. Later, Corning glass-substrates were dipped into the sol at a constant speed of 3mms -1 . To provide the necessary energy for obtaining the hexagonal ZnO structure of the coatings during the drying and consolidation process, instead of using the common furnace heat-treatment, the films were heated by means of an infrared (IR) ceramic lamp (800W) for 15, 30, 45, 60 and 180 minutes, and the effect of this annealing method was analyzed. The structural properties were examined by means of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), whereas morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The examination revealed a homogeneous distribution of particles with the characteristic pores of pluronic F127, and the coating roughness had an average value of 100nm by AFM. To evaluate the effect on the number of dipping cycles and the IR-treatment on the thickness, ellipsometry results for 1, 3 and 5 deposits were analyzed and showed increments of 780, 945 and 1082nm, respectively. Finally, to test of the antibacterial activity, instead of the common one-microorganism approach, environmental microorganisms that grow with expose of the broth to the ambient conditions were employed (microbial consortium), which is a real environmental condition. The biological test was carried out by kinetic growth inhibition (optical density) of heterotrophic bacteria in culture liquid media under conditions of light, light-dark and

Wind power integration with heat pumps, heat storages, and electric vehicles – Energy systems analysis and modelling

DEFF Research Database (Denmark)

Hedegaard, Karsten

The fluctuating and only partly predictable nature of wind challenges an effective integration of large wind power penetrations. This PhD thesis investigates to which extent heat pumps, heat storages, and electric vehicles can support the integration of wind power. Considering the gaps in existing...... in an energy system context. Energy systems analyses reveal that the heat pumps can even without flexible operation contribute significantly to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO2 emissions. When equipping the heat pumps with heat storages, only...... moderate additional benefits are achieved. Hereof, the main benefit is that the need for investing in peak/reserve capacities can be reduced through peak load shaving. It is more important to ensure flexible operation of electric vehicles than of individual heat pumps, due to differences in the load...

The influence of heat sink temperature on the seasonal efficiency of shallow geothermal heat pumps

Science.gov (United States)

Pełka, Grzegorz; Luboń, Wojciech; Sowiżdżał, Anna; Malik, Daniel

2017-11-01

Geothermal heat pumps, also known as ground source heat pumps (GSHP), are the most efficient heating and cooling technology utilized nowadays. In the AGH-UST Educational and Research Laboratory of Renewable Energy Sources and Energy Saving in Miękinia, shallow geothermal heat is utilized for heating. In the article, the seasonal efficiency of two geothermal heat pump systems are described during the 2014/2015 heating season, defined as the period between 1st October 2014 and 30th April 2015. The first system has 10.9 kW heating capacity (according to European Standard EN 14511 B0W35) and extracts heat from three vertical geothermal loops at a depth of 80m each. During the heating season, tests warmed up the buffer to 40°C. The second system has a 17.03 kW heating capacity and extracts heat from three vertical geothermal loops at a depth of 100 m each, and the temperature of the buffer was 50°C. During the entire heating season, the water temperatures of the buffers was constant. Seasonal performance factors were calculated, defined as the quotient of heat delivered by a heat pump to the system and the sum of electricity consumed by the compressor, source pump, sink pump and controller of heat pumps. The measurements and calculations give the following results: - The first system was supplied with 13 857 kWh/a of heat and consumed 3 388 kWh/a electricity. The SPF was 4.09 and the average temperature of outlet water from heat pump was 40.8°C, and the average temperature of brine flows into the evaporator was 3.7 °C; - The second system was supplied with 12 545 kWh/a of heat and consumed 3 874 kWh/a electricity. The SPF was 3.24 and the average temperature of outlet water from heat pump was 51.6°C, and the average temperature of brine flows into the evaporator was 5.3°C. To summarize, the data shown above presents the real SPF of the two systems. It will be significant in helping to predict the SPF of objects which will be equipped with ground source heat pumps.

Preliminary comparative study of anti-inflmmatory effect of unheated and heat-treated Sahara honey: In vivo approach

Directory of Open Access Journals (Sweden)

Moussa Ahmed

2015-11-01

Full Text Available Objective: To investigate the effect of unheated and heat-treated of Sahara honey. Methods: A total of 24 Swiss albino mice weighing 25–35 g were divided into four groups (n = 6. Anti-inflammatory effect was assessed at 1, 2, 3, 4, 5 and 6 h after subplantar injection of carrageenan (0.5 mL of a 1% solution in normal saline. In addition, total phenolic content was determined by modified Folin-Ciocalteu method. Results: The total phenolic content capacity of the Sahara honey before and after heat treatment was between 72 and 97.9 mg of gallic acid equivalents/100 g of honey respectively. Administration of unheated honey (oral administration reduced significantly (P < 0.05. The carrageenan induced mice paw edema model at 1, 3 and 6 h for 21.85%, 5.43% and 80.43%, respectively. Administration of heat-treated honey showed insignificant inhibition of carrageenan and induced paw edema at 1 h (31.16%, 3 h (0.25% and 6 h (34.19%. The 50 mg/kg diclofenac exhibited percent reduction in paw volume 16.12%, 8.90% and 15.32% after 1 h, 3 h and 6 h, respectively, when compared with control animals. No toxicity was identified. Conclusions: Our results suggest that unheated Sahara honey has anti-inflammatory effects by reducing the mice paw edema size while heat-treated Sahara honey decreases the antiinflammatory activity.

Geldanamycin induces heat shock protein 70 and protects against MPTP-induced dopaminergic neurotoxicity in mice.

Science.gov (United States)

Shen, Hai-Ying; He, Jin-Cai; Wang, Yumei; Huang, Qing-Yuan; Chen, Jiang-Fan

2005-12-02

As key molecular chaperone proteins, heat shock proteins (HSPs) represent an important cellular protective mechanism against neuronal cell death in various models of neurological disorders. In this study, we investigated the effect as well as the molecular mechanism of geldanamycin (GA), an inhibitor of Hsp90, on 1-methyl-4-pheny-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurotoxicity, a mouse model of Parkinson disease. Neurochemical analysis showed that pretreatment with GA (via intracerebral ventricular injection 24 h prior to MPTP treatment) increased residual dopamine content and tyrosine hydroxylase immunoreactivity in the striatum 24 h after MPTP treatment. To dissect out the molecular mechanism underlying this neuroprotection, we showed that the GA-mediated protection against MPTP was associated with a reduction of cytosolic Hsp90 and an increase in Hsp70, with no significant changes in Hsp40 and Hsp25 levels. Furthermore, in parallel with the induction of Hsp70, striatal nuclear HSF1 levels and HSF1 binding to heat shock element sites in the Hsp70 promoter were significantly enhanced by the GA pretreatment. Together these results suggested that the molecular cascade leading to the induction of Hsp70 is critical to the neuroprotection afforded by GA against MPTP-induced neurotoxicity in the brain and that pharmacological inhibition of Hsp90 may represent a potential therapeutic strategy for Parkinson disease.

Pseudomonas aeruginosa inhibits the growth of Cryptococcus species.

Science.gov (United States)

Rella, Antonella; Yang, Mo Wei; Gruber, Jordon; Montagna, Maria Teresa; Luberto, Chiara; Zhang, Yong-Mei; Del Poeta, Maurizio

2012-06-01

Pseudomonas aeruginosa is a ubiquitous and opportunistic bacterium that inhibits the growth of different microorganisms, including Gram-positive bacteria and fungi such as Candida spp. and Aspergillus fumigatus. In this study, we investigated the interaction between P. aeruginosa and Cryptococcus spp. We found that P. aeruginosa PA14 and, to a lesser extent, PAO1 significantly inhibited the growth of Cryptococcus spp. The inhibition of growth was observed on solid medium by the visualization of a zone of inhibition of yeast growth and in liquid culture by viable cell counting. Interestingly, such inhibition was only observed when P. aeruginosa and Cryptococcus were co-cultured. Minimal inhibition was observed when cell-cell contact was prevented using a separation membrane, suggesting that cell contact is required for inhibition. Using mutant strains of Pseudomonas quinoline signaling, we showed that P. aeruginosa inhibited the growth of Cryptococcus spp. by producing antifungal molecules pyocyanin, a redox-active phenazine, and 2-heptyl-3,4-dihydroxyquinoline (PQS), an extracellular quorum-sensing signal. Because both P. aeruginosa and Cryptococcus neoformans are commonly found in lung infections of immunocompromised patients, this study may have important implication for the interaction of these microbes in both an ecological and a clinical point of view.

Magnetic properties of atmospheric PMx in a small settlement during heating and non-heating season

Science.gov (United States)

Petrovsky, E.; Kotlik, B.; Zboril, R.; Kapicka, A.; Grison, H.

2012-04-01

Magnetic properties of environmental samples can serve as fast and relatively cheap proxy method to investigate occurrence of iron oxides. These methods are very sensitive in detecting strongly magnetic compounds such as magnetite and maghemite and can reveal concentration and assess grain-size distribution of these minerals. This information can be significant in estimating e.g. the source of pollutants, monitoring pollution load, or investigating seasonal and climatic effects. We studied magnetic properties of PM1, PM2.5 and PM10, collected over 32-48 hours in a small settlement in south Bohemia during heating and non-heating season. The site is rather remote, with negligible traffic and industrial contributions to air pollution. Thus, the suggested seasonal effect should be dominantly due to local (domestic) heating, burning wood or coal. In our contribution we show typical differences in PMx concentration, which is much higher in the winter (heating) sample, accompanied by SEM analyses and magnetic data oriented on concentration and grain-size distribution of magnetite/maghemite particles. While concentration of Fe-oxides does not vary that much, significant seasonal differences were observed in composition and grain-size distribution, reflecting different sources of the dust particles.

FoxO/Daf-16 restored thrashing movement reduced by heat stress in Caenorhabditis elegans.

Science.gov (United States)

Furuhashi, Tsubasa; Sakamoto, Kazuichi

2014-04-01

Many studies on thermotolerance have been done in Caenorhabditis elegans in order to extend survival under heat stress; Daf-16, a homolog of FoxO in C. elegans, was detected as the key factor in thermotolerance. However, the recovery process from heat stress damage has been seldom discussed. In this study, we analyzed the roles of FoxO/Daf-16 on the recovery from heat stress damage by monitoring thrashing movement. Heat shock reduced the movement, which was restored by culturing at 20°C. Thrashing movement was not restored in the daf-16 mutant, which suggests that Daf-16 is one of the essential factors in repairing the damage. Movement restoration was promoted in the daf-2 mutant, a homolog of insulin/IGF-1-like receptor, in a daf-16-dependent manner. In addition, heat stress decreased the expression of daf-28 and ins-7, agonists of Daf-2. Taken together, these results revealed that FoxO/Daf-16 removes heat stress damage and restores movement via inhibition of the insulin-like signaling pathway in C. elegans, suggesting that FoxO/Daf-16 plays a critical role in thermotolerance. Copyright © 2014 Elsevier Inc. All rights reserved.

An experimental and numerical study of endwall heat transfer in a turbine blade cascade including tangential heat conduction analysis

Science.gov (United States)

Ratto, Luca; Satta, Francesca; Tanda, Giovanni

2018-06-01

This paper presents an experimental and numerical investigation of heat transfer in the endwall region of a large scale turbine cascade. The steady-state liquid crystal technique has been used to obtain the map of the heat transfer coefficient for a constant heat flux boundary condition. In the presence of two- and three-dimensional flows with significant spatial variations of the heat transfer coefficient, tangential heat conduction could lead to error in the heat transfer coefficient determination, since local heat fluxes at the wall-to-fluid interface tend to differ from point to point and surface temperatures to be smoothed out, thus making the uniform-heat-flux boundary condition difficult to be perfectly achieved. For this reason, numerical simulations of flow and heat transfer in the cascade including the effect of tangential heat conduction inside the endwall have been performed. The major objective of numerical simulations was to investigate the influence of wall heat conduction on the convective heat transfer coefficient determined during a nominal iso-flux heat transfer experiment and to interpret possible differences between numerical and experimental heat transfer results. Results were presented and discussed in terms of local Nusselt number and a convenient wall heat flux function for two values of the Reynolds number (270,000 and 960,000).

Heat flow in Indian Gondwana basins and heat production of their basement rocks

Energy Technology Data Exchange (ETDEWEB)

Rao, G.V.; Rao, R.U.M.

1983-01-01

Temperatures have been measured in eight boreholes (ranging from 260 to 800 m in depth) in five Gondwana basins of the Damodar and Son valleys. With the aid of about 250 thermal conductivity determinations on core samples from these holes, heat flow has been evaluated. Measurements of radioactive heat generation have been made on samples of Precambrian gneisses constituting the basement for the Sonhat (Son valley) and Chintalapudi (Godavari valley) basins. Heat-flow values from all of the Damodar valley basins are within the narrow range of 69-79 mW/m exp(2). The value from the Sonhat basin (107 mW/m exp(2)) is significantly higher. The generally high heat flows observed in Gondwana basins of India cannot be attributed to the known tectonism or igneous activity associated with these basins. The plots of heat flow vs. heat generation for three Gondwana basins (Jharia, Sonhat and Chintalapudi) are on the same line as those of three regions in the exposed Precambrian crystalline terrains in the northern part of the Indian shield. This indicates that the crust under exposed regions of the Precambrian crystalline rocks as well as the Gondwana basins, form an integral unit as far as the present-day geothermal character is concerned. (5 figs., 14 refs., 4 tables).

Heat flow in Indian Gondwana basins and heat production of their basement rocks

Science.gov (United States)

Rao, G. V.; Rao, R. U. M.

1983-01-01

Temperatures have been measured in eight boreholes (ranging from 260 to 800 m in depth) in five Gondwana basins of the Damodar and Son valleys. With the aid of about 250 thermal conductivity determinations on core samples from these holes, heat flow has been evaluated. Measurements of radioactive heat generation have been made on samples of Precambrian gneisses constituting the basement for the Sonhat (Son valley) and Chintalapudi (Godavari valley) basins. Heat-flow values from all of the Damodar valley basins are within the narrow range of 69-79 mW/m 2. The value from the Sonhat basin (107 mW/m 2) is significantly higher. The generally high heat flows observed in Gondwana basins of India cannot be attributed to the known tectonism or igneous activity associated with these basins. The plots of heat flow vs. heat generation for three Gondwana basins (Jharia, Sonhat and Chintalapudi) are on the same line as those of three regions in the exposed Precambrian crystalline terrains in the northern part of the Indian shield. This indicates that the crust under exposed regions of the Precambrian crystalline rocks as well as the Gondwana basins, form an integral unit as far as the present-day geothermal character is concerned.

Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

Science.gov (United States)

Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

2017-06-01

Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

Investigation of internally finned LED heat sinks

Science.gov (United States)

Li, Bin; Xiong, Lun; Lai, Chuan; Tang, Yumei

2018-03-01

A novel heat sink is proposed, which is composed of a perforated cylinder and internally arranged fins. Numerical studies are performed on the natural convection heat transfer from internally finned heat sinks; experimental studies are carried out to validate the numerical results. To compare the thermal performances of internally finned heat sinks and externally finned heat sinks, the effects of the overall diameter, overall height, and installation direction on maximum temperature, air flow and heat transfer coefficient are investigated. The results demonstrate that internally finned heat sinks show better thermal performance than externally finned heat sinks; the maximum temperature of internally finned heat sinks decreases by up to 20% compared with the externally finned heat sinks. The existence of a perforated cylinder and the installation direction of the heat sink affect the thermal performance significantly; it is shown that the heat transfer coefficient of the heat sink with the perforated cylinder is improved greater than that with the imperforated cylinder by up to 34%, while reducing the mass of the heat sink by up to 13%. Project supported by the Scientific Research Fund of Sichuan Provincial Education Department (No. 18ZB0516) and the Sichuan University of Arts and Science (No. 2016KZ009Y).

District heating rehabilitation project. Viljandi - Estonia. Final report

International Nuclear Information System (INIS)

1998-04-01

The main objective of the project has been to assist Viljandi Municipality with the rehabilitation of their district heating system, and thereby to support the positive development of the district heating system in Viljandi to a more energy efficient and rational system and to achieve a significantly decrease in the pollution from the production of heat energy in Viljandi. The project has also included technical assistance to Viljandi DH company, in order to make them capable of operation and maintaining of the new substations, and also training of the local operational staff for operation of the complete district heating system. Viljandi is a county and is centrally located in Estonia, which makes Viljandi very suitable as recipient for a demonstration project. One important objective was the projects significantly positive environmental impact in reduction of the generated emissions of CO 2 , NO x and SO 2 , as the project includes installation of more efficient energy systems and supply of heat from the 2 existing district heating plants (both are partly fired with wood chips) instead of heating by very old and worn-out coal fired boilers and inexpedient designed substations with the present operational conditions. (EG)

District heating rehabilitation project. Viljandi - Estonia. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

The main objective of the project has been to assist Viljandi Municipality with the rehabilitation of their district heating system, and thereby to support the positive development of the district heating system in Viljandi to a more energy efficient and rational system and to achieve a significantly decrease in the pollution from the production of heat energy in Viljandi. The project has also included technical assistance to Viljandi DH company, in order to make them capable of operation and maintaining of the new substations, and also training of the local operational staff for operation of the complete district heating system. Viljandi is a county and is centrally located in Estonia, which makes Viljandi very suitable as recipient for a demonstration project. One important objective was the projects significantly positive environmental impact in reduction of the generated emissions of CO{sub 2}, NO{sub x} and SO{sub 2}, as the project includes installation of more efficient energy systems and supply of heat from the 2 existing district heating plants (both are partly fired with wood chips) instead of heating by very old and worn-out coal fired boilers and inexpedient designed substations with the present operational conditions. (EG)

Thermodynamic analysis and performance assessment of an integrated heat pump system for district heating applications

International Nuclear Information System (INIS)

Soltani, Reza; Dincer, Ibrahim; Rosen, Marc A.

2015-01-01

A Rankine cycle-driven heat pump system is modeled for district heating applications with superheated steam and hot water as products. Energy and exergy analyses are performed, followed by parametric studies to determine the effects of varying operating conditions and environmental parameters on the system performance. The district heating section is observed to be the most inefficient part of system, exhibiting a relative irreversibility of almost 65%, followed by the steam evaporator and the condenser, with relative irreversibilities of about 18% and 9%, respectively. The ambient temperature is observed to have a significant influence on the overall system exergy destruction. As the ambient temperature decreases, the system exergy efficiency increases. The electricity generated can increase the system exergy efficiency at the expense of a high refrigerant mass flow rate, mainly due to the fact that the available heat source is low quality waste heat. For instance, by adding 2 MW of excess electricity on top of the targeted 6 MW of product heat, the refrigerant mass flow rate increases from 12 kg/s (only heat) to 78 kg/s (heat and electricity), while the production of 8 MW of product heat (same total output, but in form of heat) requires a refrigerant mass flow rate of only 16 kg/s. - Highlights: • A new integrated heat pump system is developed for district heating applications. • An analysis and assessment study is undertaken through exergy analysis methodology. • A comparative efficiency evaluation is performed for practical applications. • A parametric study is conducted to investigate how varying operating conditions and state properties affect energy and exergy efficiencies.

A regenerative elastocaloric heat pump

Science.gov (United States)

Tušek, Jaka; Engelbrecht, Kurt; Eriksen, Dan; Dall'Olio, Stefano; Tušek, Janez; Pryds, Nini

2016-10-01

A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years; however, caloric-based technologies (those using the magnetocaloric, electrocaloric, barocaloric or elastocaloric effect) have recently shown a significant potential as alternatives to replace this technology due to high efficiency and the use of green solid-state refrigerants. Here, we report a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg-1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications.

Anxiety Impacts Cognitive Inhibition in Remitted Anorexia Nervosa.

Science.gov (United States)

Ely, Alice V; Wierenga, Christina E; Kaye, Walter H

2016-07-01

Eating disorders are complex psychiatric disorders, associated with alterations in neural and cognitive functioning. Research suggests inhibition and set-shifting deficits in anorexia nervosa (AN), but less is known about the persistence of these deficits after recovery, or their relationship to comorbid psychiatric symptoms. Women aged 19-45 remitted from AN (RAN, N = 47) and controls (CW, N = 24) completed the Delis-Kaplan Executive Function System Color-Word Interference Test. It was hypothesized that RAN, and those with higher anxiety or depression, would demonstrate worse Inhibition and Switching task performance than CW. Differences in performance between groups trended toward significance on Inhibition Ratio (p = 0.08) but were nonsignificant on Inhibition/Switching Ratio (p = 0.93). A model including State Anxiety and diagnosis revealed a significant independent effect of State Anxiety (p = 0.026), but not of diagnosis nor their interaction. Regressing State Anxiety on Color-Word Interference Test Inhibition among just the RAN group was significant [β = 0.37, t(46) = 2.63, p = 0.012] but among just CW was not (p = 0.54). Interference control for neutral stimuli is influenced by anxiety in women with a history of AN. Anxiety is linked with greater symptom severity among AN individuals, and state anxiety may account for larger deficits seen on tasks using disorder-specific stimuli. Future research is warranted to elucidate the nature of neuropsychological deficits in eating disorders. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan, inhibits type I-IV allergic inflammation and pro-inflammatory enzymes.

Science.gov (United States)

Lee, Ji Yun; Kim, Chang Jong

2010-06-01

We previously reported that arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan isolated from Forsythia koreana, exhibits anti-inflammatory, antioxidant, and analgesic effects in animal models. In addition, arctigenin inhibited eosinophil peroxidase and activated myeloperoxidase in inflamed tissues. In this study, we tested the effects of arctigenin on type I-IV allergic inflammation and pro-inflammatory enzymes in vitro and in vivo. Arctigenin significantly inhibited the heterologous passive cutaneous anaphylaxis induced by ovalbumin in mice at 15 mg/kg, p.o., and compound 48/80-induced histamine release from rat peritoneal mast cells at 10 microM. Arctigenin (15 mg/kg, p.o.) significantly inhibited reversed cutaneous anaphylaxis. Further, arctigenin (15 mg/kg, p.o.) significantly inhibited the Arthus reaction to sheep's red blood cells, decreasing the hemolysis titer, the hemagglutination titer, and the plaque-forming cell number for SRBCs. In addition, arctigenin significantly inhibited delayed type hypersensitivity at 15 mg/kg, p.o. and the formation of rosette-forming cells at 45 mg/kg, p.o. Contact dermatitis induced by picrylchloride and dinitrofluorobenzene was significantly (p arctigenin (0.3 mg/ear). Furthermore, arctigenin dose-dependently inhibited pro-inflammatory enzymes, such as cyclooxygenase-1 and 2, 5-lipoxygenase, phospholipase A2, and phosphodiesterase. Our results show that arctigenin significantly inhibited B- and T-cell mediated allergic inflammation as well as pro-inflammatory enzymes.

Madecassoside Inhibits Melanin Synthesis by Blocking Ultraviolet-Induced Inflammation

Directory of Open Access Journals (Sweden)

Eunsun Jung

2013-12-01

Full Text Available Madecassoside (MA, a pentacyclic triterpene isolated from Centella asitica (L., is used as a therapeutic agent in wound healing and also as an anti-inflammatory and anti-aging agent. However, the involvement of MA in skin-pigmentation has not been reported. This study was conducted to investigate the effects of MA on ultraviolet (UV-induced melanogenesis and mechanisms in a co-culture system of keratinocytes and melanocytes. MA significantly inhibited UVR-induced melanin synthesis and melanosome transfer in the co-culture system. These effects were further demonstrated by the MA-induced inhibition of protease-activated receptor-2 expression and its signaling pathway, cyclooxygenase-2, prostaglandin E2 and prostaglandin F2 alpha in keratinocytes. The clinical efficacy of MA was confirmed on artificially tanned human skin. MA significantly reduced UV-induced melanin index at 8 weeks after topical application. Overall, the study demonstrated significant benefits of MA use in the inhibition of hyperpigmentation caused by UV irradiation.

Nuclear boiling heat transfer and critical heat flux in titanium dioxide-water nanofluids

International Nuclear Information System (INIS)

Okawa, Tomio; Takamura, Masahiro; Kamiya, Takahito

2011-01-01

Nucleate boiling heat transfer was experimentally studied for saturated pool boiling of water-based nanofluids. Since significant nanoparticle deposition on the heated surface was observed after the nucleate boiling in nanofluids, measurement of CHF was also carried out using the nanoparticle deposited heated surface; pure water was used in the CHF measurement. In the present work, the heated surface was a 20 mm diameter cupper surface, and titanium-dioxide was selected as the material of nanoparticles. Experiments were performed for upward- and downward-facing surfaces. Although the CHFs for the downward-facing surface were generally lower than those for the upward-facing surface, the CHFs for the nanoparticle deposited surface were about 1.9 times greater than those for the bare surface in both the configurations. The CHF improvement corresponded well to the reduction of the surface contact angle. During the nucleate boiling in nanofluids, the boiling heat transfer showed peculiar behavior; it was first deteriorated, then improved, and finally approached to an equilibrium state. This observation indicated that the present nanofluid had competing effects to deteriorate and improve the nucleate boiling heat transfer. It was assumed that the wettability and the roughness of the heated surface were influenced by the deposited nanoparticles to cause complex variation of the number of active nucleation sites. During the nucleate boiling of pure water using the downward-facing surface, a sudden increase in the wall temperature was observed stochastically probably due to the accumulation of bubbles beneath the heated surface. Such behavior was not observed when the pure water was replaced by the nanofluid. (author)

Heat Transfer Characteristics of SiC-coated Heat Pipe for Passive Decay Heat Removal

International Nuclear Information System (INIS)

Kim, Kyung Mo; Kim, In Guk; Jeong, Yeong Shin; Bang, In Cheol

2014-01-01

The main concern with the Fukushima accident was the failure of active and passive core cooling systems. The main function of existing passive decay heat removal systems is feeding additional coolant to the reactor core. Thus, an established emergency core cooling system (ECCS) cannot operate properly because of impossible depressurization under the station blackout (SBO) condition. Therefore, a new concept for passive decay heat removal system is required. In this study, an innovative hybrid control rod concept is considered for passive in-core decay heat removal that differs from the existing direct vessel injection core cooling system and passive auxiliary feedwater system (PAFS). The heat transfer between the evaporator and condenser sections occurs by phase change of the working fluid and capillary action induced by wick structures installed on the inner wall of the heat pipe. In this study, a hybrid control rod is developed to take the roles of both neutron absorption and heat removal by combining the functions of a heat pipe and control rod. Previous studies on enhancing the heat removal capacity of heat pipes used nanofluids, self-rewetting fluids, various wick structures and condensers. Many studies have examined the thermal performances of heat pipes using various nanofluids. They concluded that the enhanced thermal performance of the heat pipe using nanofluids is due to nanoparticle deposition on the wick structures. Thus, the wick structure of heat pipes has been modified by nanoparticle deposition to enhance the heat removal capacity. However, previous studies used relatively small heat pipes and narrow ranges of heat loads. The environment of a nuclear reactor is very specific, and the decay heat produced by fission products after shutdown is relatively large. Thus, this study tested a large-scale heat pipe over a wide range of power. The concept of a hybrid heat pipe for an advanced in-core decay heat removal system was introduced for complete

Heat Transfer Characteristics of SiC-coated Heat Pipe for Passive Decay Heat Removal

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Mo; Kim, In Guk; Jeong, Yeong Shin; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2014-10-15

The main concern with the Fukushima accident was the failure of active and passive core cooling systems. The main function of existing passive decay heat removal systems is feeding additional coolant to the reactor core. Thus, an established emergency core cooling system (ECCS) cannot operate properly because of impossible depressurization under the station blackout (SBO) condition. Therefore, a new concept for passive decay heat removal system is required. In this study, an innovative hybrid control rod concept is considered for passive in-core decay heat removal that differs from the existing direct vessel injection core cooling system and passive auxiliary feedwater system (PAFS). The heat transfer between the evaporator and condenser sections occurs by phase change of the working fluid and capillary action induced by wick structures installed on the inner wall of the heat pipe. In this study, a hybrid control rod is developed to take the roles of both neutron absorption and heat removal by combining the functions of a heat pipe and control rod. Previous studies on enhancing the heat removal capacity of heat pipes used nanofluids, self-rewetting fluids, various wick structures and condensers. Many studies have examined the thermal performances of heat pipes using various nanofluids. They concluded that the enhanced thermal performance of the heat pipe using nanofluids is due to nanoparticle deposition on the wick structures. Thus, the wick structure of heat pipes has been modified by nanoparticle deposition to enhance the heat removal capacity. However, previous studies used relatively small heat pipes and narrow ranges of heat loads. The environment of a nuclear reactor is very specific, and the decay heat produced by fission products after shutdown is relatively large. Thus, this study tested a large-scale heat pipe over a wide range of power. The concept of a hybrid heat pipe for an advanced in-core decay heat removal system was introduced for complete