Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-36429981

RESUMO

In workplaces such as steel, power grids, and construction, firefighters and other workers often encounter non-uniform high-temperature environments, which significantly increase the risk of local heat stress and local heat discomfort for the workers. In this paper, a multi-segment human bioheat model is developed to predict the human thermal response in asymmetric high-temperature environments by considering the sensitivity of the modeling to angular changes in skin temperature and the effects of high temperatures on human thermoregulatory and physiological responses simultaneously. The extended model for asymmetric high-temperature environments is validated with the current model results and experimental data. The result shows that the extended model predicts the human skin temperature more accurately. Under non-uniform high-temperature conditions, the local skin temperature predictions are highly consistent with the experimental data, with a maximum difference of 2 °C. In summary, the proposed model can accurately predict the temperature of the human core and skin layers. It has the potential to estimate human physiological and thermoregulatory responses under uniform and non-uniform high-temperature environments, providing technical support for local heat stress and local thermal discomfort protection.


Assuntos
Temperatura Alta , Temperatura Cutânea , Humanos , Temperatura , Regulação da Temperatura Corporal/fisiologia , Resposta ao Choque Térmico
2.
Front Chem ; 10: 1001531, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36110136

RESUMO

Electrochromic devices (ECDs) that display multicolor patterns have gradually attracted widespread attention. Considering the complexity in the integration of various electrochromic materials and multi-electrode configurations, the design of multicolor patterned ECDs based on simple approaches is still a big challenge. Herein, it is demonstrated vivid ECDs with broadened color hues via introducing carbon dots (CDs) into the ion electrolyte layer. Benefiting from the synergistic effect of electrodes and electrolytes, the resultant ECDs presented a rich color change. Significantly, the fabricated ECDs can still maintain a stable and reversible color change even in high temperature environments where operating temperatures are constantly changing from RT to 70°C. These findings represent a novel strategy for fabricating multicolor electrochromic displays and are expected to advance the development of intelligent and portable electronics.

3.
Small ; 18(18): e2200916, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35355413

RESUMO

The filtering capacitor plays an essential role in the ever-increasing electronics for current stability in complicated environments. However, because of the low specific capacitance and bulky volume, current filtering devices have difficulty satisfying the harsh temperature environment and small size for supercomputers, electric vehicles, aircraft and so on. Therefore, an ultra-fast electrochemical capacitor is developed on the basis of vertically oriented graphene iongel electrodes (GI-EC), which demonstrates excellent alternate current line-filtering performance with both hot tolerance of up to 150 °C and a wide voltage window of 4 V. Because of the particularly oriented graphene nanosheets induced fast ion transport, this ionic electrochemical capacitor displays a high areal specific energy density of 1784 µF V2  cm-2 with a phase angle of -80.0° (120 Hz) at 150 °C, which is greater than most of the reported electrochemical capacitors. Moreover, it can filter arbitrary waveforms to smooth direct current signals and works well with a wide frequency range from 10 to 104  Hz. The easy integration of GI-ECs in series or parallel can also further deliver desired capacitances or high voltages. The GI-EC with high-rate performance, wide voltage window, and high-temperature adaptability presents a great promise for universally applicable filtering capacitors.

4.
Biomed Rep ; 2(5): 687-692, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25054012

RESUMO

The purpose of the present study was to investigate the effects of high ambient temperature on the neuropeptide Y (NPY) mRNA level in the hypothalamus, the plasma concentration of corticotropin-releasing hormone (CRH), cortisol (Cor), heat-shock protein 70 (HSP70) and epinephrine (EPI), and the intervention of lycium barbarum polysaccharides (LBPs) in rats. Compared to the control (CN) group, the plasma levels of CRH, Cor, HSP70 and EPI were markedly increased, and the level of NPY mRNA was downregulated in the high ambient temperature (HT) group. By contrast, rats in the HT + LBP (HTL) group had: i) a significantly enhanced expression of HSP70 compared to the HT and CN groups; ii) clearly increased plasma levels of CRH, Cor and EPI compared to the CN group; and iii) a markedly upregulated expression of NPY mRNA compared to the HT group. Thus, the results showed that high-temperature environments may damage the body, and LBPs have a potentially protective function by increasing the expression of HSP70 and NPY.

5.
Artigo em Japonês | WPRIM (Pacífico Ocidental) | ID: wpr-362624

RESUMO

[Objective] Perspiration is almost only heat radiation mechanism under high temperature environments. And sudoriferous water is supplied from blood. Blood flow is determined by blood fluidity, blood volume and the cardiovascular system. It was reported that strong stress decreased blood fluidity.In this experiment, we investigated the relation between blood fluidity and water supply in rats loaded with forced exercise in high temperature environment.[Methods] SPF male Wistar rats weighing 250g were used. All animals were put in high temperature environment (Wet Bulb Globe Temperature; WBGT: 28°C) through whole experimental period. The rats were divided into four groups randomly; Suitable temperature environment-Exercise-Non water intake (SEN), High temperature environment-Exercise-Non water intake (HEN), High temperature environment-Exercise-Water intake (HEW) and Baseline (BL). In a group of water supply, distilled water was served before and later exercise by sonde forcibly. The blood was collected before or later of exercise and blood and erythrocyte suspension fluidity were measured.[Results] In the HEN, hydroperoxides, blood sodium, lactic acid and adrenaline increased while blood and erythrocyte suspension fluidity were decreased significantly compared with the BL. In addition, the hematocrit did not increase even if water equivalent to 4% of body weight lost it.[Conclusion] We speculate that exercise in high temperature environment decreases blood fluidity. However, the water supply in exercise that might not be sufficiently improve blood fluidity.

6.
Artigo em Japonês | WPRIM (Pacífico Ocidental) | ID: wpr-362618

RESUMO

[Objective] Physical exercises raise more or less body temperature. A body temperature is regulated constantly generally by homeostasis mechanism. Perspiration is only heat radiation mechanism under high temperature environments. And sudoriferous water is supplied from blood. Blood flow is determined by blood fluidity, blood volume and the cardiovascular system. It was reported that strong stress decreased blood fluidity.In this experiment, we investigated the relation between blood fluidity and water supply in rats loaded with forced exercise in high temperature environment.[Methods] SPF male Wistar rats weighing 150 g were used. All animals were put in high temperature environment (Wet Bulb Globe Temperature; WBGT: 28°C) through whole experimental period. In a group of water supply, distilled water was served before and later exercise by sonde forcibly. The rats were divided into five groups randomly; Rest-Non water intake (RN), Rest-Water intake (RW), Exercise-Non water intake (EN), Exercise-Water intake (EW) and Baseline (B). The blood was collected before or later of exercise and blood fluidity or platelet aggregation was measured.[Results] In the EN, platelet aggregation, lactic acid and corticosterone increased while blood fluidity were decreased significantly compared with the RN, RW and EW. In addition, the hematocrit did not increase even if water equivalent to 8 % of body weight lost it.[Conclusion] We speculate that exercise in high temperature environment decreases blood fluidity. However, the water supply that does not completely make up for quantity of depletion in exercise may improve blood fluidity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...