Considering our daily life, we spend a great deal of our time in artificial environments, particularly during summer and winter. Therefore, how to optimize indoor environments is of significant importance. This paper deals with the definition of pleasantness and discusses on how to control a healthful and comfortable indoor environment. Pleasantness in thermal environments is also discussed. Six criteria for a healthy residential environment are proposed as follows;(1) prevention of accidents and disasters (2) satisfaction of physiological requirements (3) satisfaction of requirements of living (4) prevention of disease and infection (5) economy in living expenditure and (6) mental and emotional satisfaction.
The calculation of heat debt through indirect calorimetry requires an accurate assessment of the various components of heat production and heat loss. This paper presents methods of analysis and interpretation of data based on a review of recent advances. Topics include the assessment of body characteristics (surface area, body fat, specific heat, and deep body and skin temperatures), metabolic heat production and shivering metabolism, sensible (conductive, convective, radiative) and insensible (sweating) heat losses, respiratory heat losses, and concludes with a critical examination of mean body temperature. Where measurements of certain variables are unavailable, methods of prediction are suggested.
The pioneering work of J.S. Haldane with the first decompression table in 1906 has generated considerable research and effort towards the development of safer and more rapid decompression procedures. The deterministic approach is governed by a fixed set of rules that defines the boundary between safe and unsafe dives and includes a model for gas exchange and an ascent criterion, such as gas supersaturation, to calculate the "safe" decompression depth. These decompression models are essentially empirical and provide "safe" decompression only over a limited range of depth and bottom times. The statistical approach considers DCI to be a probabilistic event and uses a risk function consisting of a gas exchange component and an ascent criterion to estimate or predict the risk of DCI. The ascent criterion can be based on supersaturation or bubble growth. To determine the risk function, a large data set of precise dive data, including time, depth, gas composition, and DCI outcome, must be available to match the predicted risk with the observed data. Probabilistic models of decompression can be used to analyze dive tables and procedures, compare different tables, and develop decompression tables with a given risk level. The probabilistic approach for decompression is a very powerful technique that could lead to a better insight into the physics and physiology of decompression because of its objectivity and potential for implementing a variety of models in the design of the risk functions for DCI. This review compares both approaches and discusses current and future challenges in the quest for a universal decompression model.
The block effects of overlaid building materials on emission of perceived air pollutants from covered adhesives were studied. A carpet and a wallpaper were used as solid materials. Box-sized small chambers were prepared to supply constant air to the sample of specimen. Untrained panel evaluated the perceived air pollution from the single materials (solid material itself and adhesive itself) and combinations of the overlaid solid material and the covered adhesive. The odor intensity of the pollutants from the combination of the solid material and the adhesive was lower than the sum of the odor intensity from the single material. The overlaid solid materials might have blocked the emission of the air pollutants from the covered adhesive. It was found that the block effect on perceived air pollutants was greater than that on TVOC emission.
This paper examines the comfort criteria of ANSI/ASHRAE Standard 55-1992, Thermal Environmental Conditions for Human Occupancy (1) for their applicability in tropical classrooms. A field study conducted in Hawaii used survey questionnaires, physical measurements, interviews, and behavioral observations to collect the data. A total of 3,544 students and teachers completed questionnaires in 29 naturally-ventilated and air-conditioned classrooms in six schools during two seasons. The majority of classrooms failed to meet the physical specifications of the Standard 55 comfort zone. Acceptability votes by occupants of both naturally-ventilated and air-conditioned classrooms exceeded the Standard 55 criteria, regardless of whether physical conditions were in or out of the comfort zone. Responses from these two school populations suggest not only a basis for separate comfort standards, but energy conservation opportunities through raising thermostat set points.
Weight-bearing and physical activity are important mechanical stimuli for bone metabolism. The current study was carried out to investigate the effect of compulsive running exercise on bone mineral density (BMD) and bone metabolism in the growing male Stroke-Prone Spontaneously Hypertensive Rat (SHRSP). Twelve SHRSP aged 7 weeks were randomly divided into a sedentary control group (C-group, n=6) and a compulsive running exercise group (R-group; 17 m/min., 60 min./day, 5 days/week for 12 weeks, n=6). Measured responses to the training were total and femoral BMD (by DEXA; DPXL, Lunar, USA) and the mechanical strength of bone (MSB, by three point-bending test; AGS-100D, Shimazu. Japan). The metabolism markers of bone such as alkaline phosphatase (AlP), tartrate-resistant acid phosphatase (TrAcP), intact parathyroid hormone (i-PTH), calcium (Ca) and phosphate (P) were measured. Compared with the C-group, the changes in body weight tended to decrease in the R-group after the age of 10 weeks (P<0.001), and femoral BMD (P<0.05) and bone mineral content (BMC) (P<0.01) in the R-group were shown to be significantly lower than in the C group. Most measurement parameters of the femora, including bone weight (P<0.001), bone length (P<0.001), MSB (P<0.01), femoral Ca (P<0.001), and P (P<0.001) in the R-group were significantly lower than in the C-group. Although serum Ca concentration remained unchanged in both groups, AlP in the R-group was significantly higher than in the C-group (P<0.01), and TrAcP tended to increase in the R-group. These results suggest that compulsive running exercise for 12 weeks leads to the high bone turnover and inhibits the deposition of Ca and P in the bone, which eventually induces osteopenia in growing SHRSP.
Laboratory experiments are conducted with the use of clothed subjects in order to clarify the effects of moisture movement and accumulation in clothing on the body temperature regulation system. The sweating and evaporation process is focused on as a typical situation that people experience under a hot climate. The thermal transients a subject is exposed to are comprised of three steps as follows: Step 1: 25[°C], RH 50%, for 30 minutes; Step 2: 35[°C], RH 90%, for 30 minutes; and Step 3: 25[°C], RH 50%, for 60 minutes. Not only the skin temperatures but also the clothing temperatures are measured during the process, and the influence of the moisture on the skin temperature is investigated based on measured results. Our conclusions are as follows.For the sweating processa) The clothing temperatures show two sharp rises explained by moisture absorption into the clothing from the ambient air and the skin.b) The rise in clothing temperature seems to affect the skin temperature. In order to explain the variation in the clothing and the skin temperatures, it might be necessary to take into account the contact between the skin and the clothing.For the evaporation processa) The unclothed skin temperatures show a sharp decrease 5-10 minutes after moving to the low temperature environment and, after that, the temperatures remain almost constant.b) The clothing and the clothed skin temperatures first decrease and then increase. The time when they assume the minimum values is closely related to the amount of moisture accumulated at the point of the body. In most experiments, it is earliest at the shoulder.c) The clothed skin temperatures assume their minimum values much later than the unclothed skin temperatures. Not only the thermal and the hygric resistance of the clothing but also the moisture accumulation in the clothing is responsible for this fact.
Variables affecting thermal resistance of infant bedding materials arranged to simulate use are described and an alternative method for estimating thermal resistance (dry) of multiple layers is proposed. Thermal resistance was determined when materials were flat and spaced to simulate use, using a guarded-hotplate similar to that specified in ISO11092:1993(E).