365 resultados para heat-stress
Resumo:
Numerical investigation of free convection heat transfer in an attic shaped enclosure with differentially heated two inclined walls and filled with air is performed in this study. The left inclined surface is uniformly heated whereas the right inclined surface is uniformly cooled. There is a heat source placed on the right side of the bottom surface. Rest of the bottom surface is kept as adiabatic. Finite volume based commercial software ANSYS 15 (Fluent) is used to solve the governing equations. Dependency of various flow parameters of fluid flow and heat transfer is analyzed including Rayleigh number, Ra ranging from 103 to 106, heater size from 0.2 to 0.6, heater position from 0.3 to 0.7 and aspect ratio from 0.2 to 1.0 with a fixed Prandtl number of 0.72. Outcomes have been reported in terms of temperature and stream function contours and local Nusselt number for various Ra, heater size, heater position, and aspect ratio. Grid sensitivity analysis is performed and numerically obtained results have been compared with those results available in the literature and found good agreement.
Resumo:
In our large library of annotated environmental recordings of animal vocalizations, searching annotations by label can return thousands of results. We propose a heat map of aggregated annotation time and frequency bounds, maintaining the shape of the annotations as they appear on the spectrogram. This compactly displays the distribution of annotation bounds for the user's query, and allows them to easily identify unusual annotations. Key to this is allowing zero values on the map to be differentiated from areas where there are single annotations.
Resumo:
Numerical study has been performed in this study to investigate the turbulent convection heat transfer on a rectangular plate mounted over a flat surface. Thermal and fluid dynamic performances of extended surfaces having various types of lateral perforations with square, circular, triangular and hexagonal cross sections are investigated. RANS (Reynolds averaged Navier–Stokes) based modified k–ω turbulence model is used to calculate the fluid flow and heat transfer parameters. Numerical results are compared with the results of previously published experimental data and obtained results are in reasonable agreement. Flow and heat transfer parameters are presented for Reynolds numbers from 2000 to 5000 based on the fin thickness.
Resumo:
As the key neuron-to-neuron interface, the synapse is involved in learning and memory, including traumatic memories during times of stress. However, the signal transduction mechanisms by which stress mediates its lasting effects on synapse transmission and on memory are not fully understood. A key component of the stress response is the increased secretion of adrenal steroids. Adrenal steroids (e.g., cortisol) bind to genomic mineralocorticoid and glucocorticoid receptors (gMRs and gGRs) in the cytosol. In addition, they may act through membrane receptors (mMRs and mGRs), and signal transduction through these receptors may allow for rapid modulation of synaptic transmission as well as modulation of membrane ion currents. mMRs increase synaptic and neuronal excitability; mechanisms include the facilitation of glutamate release through extracellular signal-regulated kinase signal transduction. In contrast, mGRs decrease synaptic and neuronal excitability by reducing calcium currents through N-methyl-D-aspartate receptors and voltage-gated calcium channels by way of protein kinase A- and G protein-dependent mechanisms. This body of functional data complements anatomical evidence localizing GRs to the postsynaptic membrane. Finally, accumulating data also suggest the possibility that mMRs and mGRs may show an inverted U-shaped dose response, whereby glutamatergic synaptic transmission is increased by low doses of corticosterone acting at mMRs and decreased by higher doses acting at mGRs. Thus, synaptic transmission is regulated by mMRs and mGRs, and part of the stress signaling response is a direct and bidirectional modulation of the synapse itself by adrenal steroids.
Resumo:
This report presents the findings from a study of the financial impact of work-integrated learning commonly referred to as 'placement' among social work and human services students. Based on a survey of 214 respondants, 14 in-depth interviews and two focus groups, the findings indicate that two thirds of the surveyed group felt tired and anxious about their experience of balancing paid work and placement, with 2 in 5 reporting their learning experience was compromised as a result. The significant implications and potential solutions are also discussed.
Resumo:
Pressure on children to succeed in high schools is a serious problem in Asian societies. The focus of this study in three provinces of Vietnam was to identify the thresholds at which supplementary study has positive or negative effects on mental health and academic achievement. The findings contribute evidence for parents, teachers and young people about optimal levels of supplementary study (2–3 hours per day) and the most beneficial mode (self-study versus cram classes and private tutors). The work will be used to inform policy makers about strategies to minimize harmful effects of study burden for high school students.
Resumo:
The purpose of this study was to examine the main and interactive effects of four dimensions of professional commitment on strain (i.e., depression, anxiety, perceived health status, and job dissatisfaction) for a sample of 176 law professionals. The study utilized a two-wave design in which professional commitment and strain were measured at Time 1 and strain was measured again at Time 2 (T2), 2 months later. A significant two-way interaction indicated that high affective commitment was related to less T2 job dissatisfaction only for lawyers with low accumulated costs. A significant four-way interaction indicated that high affective professional commitment was only related to fewer symptoms of T2 anxiety for lawyers with high normative professional commitment and both low limited alternatives and accumulated costs. A similar pattern of results emerged in regard to T2 perceived health status. The theoretical and practical implications of these results for career counselors are discussed.
Resumo:
Morphological and physiological characteristics of neurons located in the dorsolateral and two ventral subdivisions of the lateral amygdala (LA) have been compared in order to differentiate their roles in the formation and storage of fear memories (Alphs et al, SfN abs 623.1, 2003). Briefly, in these populations, significant differences are observed in input resistance, membrane time constant, firing frequency, dendritic tortuosity, numbers of primary dendrites, dendritic segments and dendritic nodes...