Effect Of Thermal Conditions Research Articles

Effects of Thermal Conditions on Sink-Mark Generation of Press-Formed Glass. Measurement of Temperature of Glass and Generation Process of Sink-Mark.

Effects of Thermal Conditions on Sink-Mark Generation of Press-Formed Glass. Measurement of Temperature of Glass and Generation Process of Sink-Mark.

The effects of thermal conditions on the cell sizes of two-dimensional convection

The effects of thermal conditions on the patterns of two-dimensional Boussinesq convection are studied by numerical integration. The adopted thermal conditions are (i) the heat fluxes through both upper and lower boundaries are fixed, (ii) the same as (i) but with internal cooling, (iii) the temperature on the lower boundary and the heat flux through the upper boundary are fixed, (iv) the same as (iii) but with internal cooling, and (v) the temperatures on both upper and lower boundaries are fixed. The numerical integrations are performed with Ra = 104 and Pr = 1 over the region whose horizontal and vertical lengths are 8 and 1, respectively.The results confirm that convective cells with the larger horizontal sizes tend to form under the conditions where the temperature is not fixed on any boundaries. Regardless of the existence of internal cooling, one pair of cells spreading all over the region forms in the equilibrium states. On the other hand, three pairs of cells form and remain when the temperature on at least one boundary is fixed. The formation of single pairs of cells appearing under the fixed heat flux conditions shows different features with and without internal cooling. The difference emerges as the appearance of a phase change, whose existence can be suggested by the weak nonlinear equation derived by Chapman & Proctor (1980).

Energy metabolism and evaporative water loss of Pristidactylus lizards

The effects of thermal conditions on the components of the physiological traits, energy metabolism and evaporative water loss, were studied in two species of Pristidactylus lizards, from different thermal habitats, forest and scrubland areas. The compared species had similar average daily metabolic rates, pulmo-cutaneous and pulmonary evaporative water loss. They differ in the daily distribution of energy expenditure, and in the voluntary aerobic scope. Similarities in most of the studied variables, may reflect either functional or historical constraints on these variables.

The Influence of Thermal Conditions on Teachers’ Work and Student Performance

Using the Schools Council initiative to construct a Teaching Charter as an example, proposes that the orthodox analysis of the relationships between teachers′ work and student performance is incomplete. To this end, research into climatic conditions that affect human physical, emotional and cognitive performance is reviewed. Argues that Australian educational research and policy have ignored the potential of direct and indirect effects of thermal conditions to influence school outcomes adversely. Concludes that there is a case for educational research and policy to account for climatic factors, especially the interactions between social, psychological, cultural and thermal variables in the formulation of teacher and student performance standards.

Effect of thermal conditions during welding on cracking resistance of welded joints in 15Kh1M1F steel under low‐cycle creep conditions

Effect of thermal conditions during welding on cracking resistance of welded joints in 15Kh1M1F steel under low‐cycle creep conditions

Herpesvirus cyprini: Thermal Effects on Pathogenicity and Oncogenicity.

Effects of thermal conditions on CHV infection were investigated both in vitro and in vivo. CHV multiplied in FHM cells at incubation temperatures from 10°C to 25°C, but not at 30°C, optimal temperature being 15-20deg;C. Experimental infection of CHV was done on carp fry under controlled water temperatures of 15, 20 and 25°C. The mortality of carp fry due to CHV infection was markedly high at 15°C and decreased with the increase in water temperature. A papilloma was formed after 11 weeks at all temperatures tested.A regression of the papilloma was observed by shifting water temperature from 7.5°C to 20, 25 and 30°C but no regression of papilloma was observed by the shift of water temperature from 7.5°C to 15°C.

Morphological responses in thermally conditioned linear low density polyethylene

AbstractAn octene‐modified linear low density polyethylene has been used to examine the mechanisms involved during thermal annealing. Annealing temperatures ranged from 60 to 100°C. Annealing results in crystallinity increments and these respond to two concurrent effects. One involves the segregation from crystalline regions of low molecular weight moieties in the polymer's molecular weight distribution; the other is lamellar thickening, leading to the formation of more highly perfected crystalline domains. In the present polymer, the two effects were found to be in balance at annealing temperatures near 80°C leading to the optimum distribution of crystalline regions in the amorphous portions of the polymer. The effect of thermal conditioning on mechanical properties of the polymer was illustrated in terms of the initial modulus and the polymer's yield strength. The twin mechanisms of molecular fractionation and lamellar thickening were found to influence both of the mechanical property parameters.

Effect of thermal conditions and alloying constituents (Ni, Cr) on macrosegregation in continuously cast high-carbon (0.8 Pct), low-alloy steel

The aim of this study was to investigate the influences of heat transfer, thermal gradient, solidification rate, and the addition of up to 1 pct Ni and 1 pct Cr on the solidification and macrosegregation of high-carbon (0.8 pct), low-alloy steel. Sixteen 13.6-kg laboratory ingots were horizontally and unidirectionally cast in a static moll, fitted on one face with a water-cooled copper chill to simulate a continuous casting mold. Thermocouples, placed in the chill and the mold, were used to calculate heat flux, thermal gradient, and solidification rate. The ingots were examined with respect to macro- and microstructures, distribution of phases, dendrite arm spacing, and solute element distribution. The extent of macrosegregation of carbon and sulfur was determined by wet chemical analysis of drillings, and a TANDEM VAN DE GRAAFF accelerator was used for A1, Si, P, V, S, C, Mn, Ni, and Cu. The extent of macrosegregation of these elements was correlated with heat transfer and thermodynamic distribution coefficient data.

Effect of Thermal Conditions on the Acceptability of Respiratory Protective Devices on Humans at Rest

Effect of Thermal Conditions on the Acceptability of Respiratory Protective Devices on Humans at Rest

Effect of thermal conditions on the acceptability of respiratory protective devices on humans at rest.

The physiological and subjective responses of six sedentary subjects wearing half-facepiece respirators were observed over a wide range of room and respirator air conditions. Room air and dew-point (Ta:Tdp) temperatures were 25:11 degrees, 30:13 degrees, and 35:16 degrees C in still air. Respirator air temperatures were maintained independently of room conditions at 27 degrees, 30 degrees, 33 degrees, and 36 degrees C with relative humidity levels of 47% and 73%. Physiological measurements included local skin and dew-point temperatures. Subjective judgments of acceptability, thermal sensation, degree of discomfort, sense of skin moisture, and difficulty of breathing were recorded separately for the thermal environment in the room and inside the respirator. Respirator temperatures cooler than 33 degrees C were always comfortable and 100% acceptable; respirator air temperatures above 33 degrees C or higher humidity levels decreased respirator acceptability. Acceptability of the respirator environment decreased as lip temperature increased above 34.5 degrees C or when respirator dew-point temperature increased above 20 degrees C. Increased respirator air temperature and humidity often made breathing seem "slightly hard." The respirator conditions influenced the subjects' judgment of the acceptability of the surrounding thermal environment.

Effects of thermal conditions at the upper boundary on the evolution of a combustion focus and the convective ignition limits in a closed vessel

Thermal conditions at the upper vessel wall play an important part in the focal ignition of a gas mixture in a closed vessel by the three-stage scheme presented. This process is examined numerically in a planar formulation for a thermally insulated upper boundary. The article considers the evolution of a given focus under conditions where the upper wall in the closed planar vessel of square section is maintained at the initial temperature (room temperature). The features of the focal ignition and the behavior of the limiting curves for vessels with adiabatic and cold upper walls for the normal acceleration due to gravity, under conditions of weightlessness, and on overloading are compared. The most important difference in the focus evolution when the thermal conditions at the upper wall are altered is that the inflammation leading to complete combustion occurs in various regions of vigorous reaction produced as the focus rises.

周囲色彩に対する評価に及ぼす温熱環境の影響

周囲色彩に対する評価に及ぼす温熱環境の影響

Influence of thermal conditions on the efficiency of high-performance liquid chromatographic columns

The effect of thermal conditions on efficiency in high-performance liquid chromatography is investigated with special reference to the role of the viscous heat dissipation. In systems thermostatted by a water-bath or jacket it turns out to be advantageous to pre-cool the mobile phase when high flow-rates and small particle sizes are used. This is explained by a compensation of band broadening in the first and second part of the column. The wall region of the band moves faster in the first part, but it moves slower in the second part and it is eluted together with the solute from the core region. Our results indicate that a similar compensation effect occurs when the column is operated in still air. This is due to back-flow of heat through the stainless-steel column wall. For large diameter columns (larger than 3 mm), packed with small particles, a linear temperature profile imposed on the column wall may diminish the detrimental effects of viscous heat dissipation. Results obtained with such a system are promising.

Effect of thermal conditions of preparation of dispersion-strengthened nickel powders on the character of distribution of the strengthening phase

The thermal conditions of treatment of oxide powders produced by chemical coprecipitation exert a pronounced influence on the mechanical properties of semifinished products of dispersion-strengthened nickel made from these powders. Raising the calcining temperature of such oxide powders activates particle redistribution processes and has an adverse effect on the uniformity of distribution of the strengthening phase, which leads to the formation of large particles in the subsequent stages of plastic working and heat treatment of the powders and a steady deterioration in the mechanical properties of semifinished products.

Effect of thermal conditions on the stability of a crystallization process from a melt

The stability of a crystallization process from a melt is considered in the approximation of the one-dimensional thermal problem in relation to random displacements of the liquid and solid phase interface as a function of the crystallization conditions.

Limiting effect of thermal conditions on the characteristics of fuel cells

Methods of calculating and measuring the temperature fields of fuel cells are analyzed, in order to determine the maximum allowable temperature-limited electric loading.

A differential thermal analysis study of the effects of thermal history on polyethylene

AbstractThe melting and crystallization behavior of polyethylene samples has been investigated by differential thermal analysis (DTA), with special emphasis on the effects of thermal conditioning on the crystalline state of the sample. Techniques are outlined for impressing a wide variety of thermal histories on the sample in the DTA cell. In particular, the use of an annealing procedure is shown to provide a significant evaluation of the extrapolated value of the equilibrium melting temperature, combined with a rapidity not possible by the dilatometric method. Theoretical implications of the various procedures and results are briefly discussed. Critical examination of the fine structure observed in the melting thermograms leads to the conclusion that under certain conditions crystallites originating from both heterogeneous and homogeneous nucleation can be detected. The temperature rise associated with very fast crystallization is considered to influence the subsequent melting temperature more significantly than the effects of re‐crystallization during the actual melting cycle. Some illustrations are given of the general usefulness of the conditioning procedures in clarifying phenomena observed with various samples.

Effects of thermal conditioning on metabolic responses of rats to altitude.

The metabolic responses of rats acclimated to different temperatures (3°, 24° and 35°C) were compared during a 24-hour fasting exposure to low barometric pressure (380 mm Hg). Determinations included fasting weight loss, water intake, urine volume and urinary excretion of Na, K, Mg, Ca, PO4, urea, uric acid, creatinine, creatine, taurine, ß-alanine, glycine, α-alanine, valine + methionine, serine, threonine, tyrosine, glutamic acid, aspartic acid, lysine, arginine and histidine. Since the altitude tests were made at a neutral temperature (25°C) the altitude responses, per se, were determined by comparing the ground and altitude responses of each acclimated group at neutral temperatures. These comparisons revealed that the acclimated state of the rats exercised a strong influence on the altitude response for most of the variables. There were significant intergroup differences in this response for all variables except phosphate, urea, taurine, valine + methionine, serine, histidine and the Mg/Ca ratio.