The purpose of this study was to determine the usefulness of physiological studies in the evaluation of protective clothing for work in a cold environment. The study included the examination of the dynamics of changes in chosen physiological parameters (core and skin temperatures, heart rate, pulmonary minute ventilation) as well as physical ones (the temperature and relative humidity under the clothes) during work in protective clothing with unknown thermal insulation. The experiment was conducted in extreme environmental conditions (–10 and –15°C) at a work load defined by the clothing manufacturer as moderate. Results show that thermal equilibrium was achieved and maintained throughout the investigated work time (60 min) and that the protective clothing ensures safety on the time scale of a regular 8-hour work day. It was also shown that the dynamics of thermal stress physiological parameters can be used to determine the maximum duration of exposure for cold protective clothing with unknown thermal insulation. 相似文献
A new workplace is a result of changing a work post or undertaking a new job. Direct indices of adaptation to this situation (average mood at the workplace and job satisfaction) and the indirect ones (costs like health complaints and the level of depressing or facilitating anxiety) are analysed with regard to reactivity and values-motives coherence at work. Sixty bank workers were investigated. The obtained results confirm that mood and costs depend on reactivity, but satisfaction with work depends on coherence. Only achievement values-motives coherence at work differentiates direct and indirect indicators of adaptation. Considering both kinds of variables modifies dependencies. Some theoretical and practical conclusions resulting from the research are included. 相似文献
Here we demonstrate that precipitation of dissolved inorganic carbon (DIC) to at pH 10.26, 11.38 and 12.11 does not cause
measurable carbon isotope fractionation. However, NaOH solution prepared under standard laboratory procedure and used to increase
pH value for precipitation of BaCO3 can be contaminated by atmospheric CO2. In our experiment, δ13C value in the contaminant DIC was −24.30‰, which resulted in decrease in the δ13C(DIC) value by 0.03, 0.07 and 0.22 at pH 10.26, 11.38 and 12.11, respectively. 相似文献
Four experiments were carried out to assess effects of product warning explicitness on purchase preferences and caution in use. Explicitness was defined as the specificity or detail with which potential injury consequences were described. All experiments employed a paradigm in which warnings varying in explicitness were described for familiar products. Subjects rated various perceptions of the products, purchase preferences, and intent to act cautiously in using the product. Results indicated that more explicit warnings were associated with greater levels of perceived dangerousness, hazard understanding, injury severity, and manufacturers' concern. While explicit warnings were also associated with an increased intent to act cautiously in using products, no clear relationship was found between explicitness and purchase preferences. It is recommended that product warnings should be explicit regarding injury consequences, especially where injuries may be severe. Given such information, product users, particularly those less familiar with a product, are more likely to exercise greater caution during use. Further, manufacturers' concern that explicit warnings may negatively impact sales appears to be unwarranted. 相似文献
Agrodiversity – the diversity of cropping systems, crop species and farm management practices has received increasing attention in recent years as a way of spreading risk and supporting food security in resource-poor farming systems. This paper discusses the dynamic aspects of indigenous soil and water conservation (ISWC) practices in a semi-arid part of Kenya. The objective is to show the range of sources of variability and diversity that prevail in this environment, the responses of farmers to this variability, and the way farmers' rationalise the heterogeneity of soil and water management practices. Methods used included participatory surveys and evaluations, on-farm monitoring, soil and rainfall data analyses, and questionnaire surveys. Sources of variability affecting cropping systems and land management practices included rainfall, soil fertility, farmer resource level and farm productivity. A decision-tree was developed to examine how biophysical and socio-economic variability affected farmers' choice of ISWC. Different ISWC structures dominated on sandy and stony soils, respectively. Low resource farmers tended to choose cheaper and less labour demanding techniques, and constructed smaller ISWC structures than better endowed farmers. The largest diversity of ISWC practices was found on newly-opened land with mixed soils. Moreover, on-farm productivity levels indicated that costly investments in SWC are unfeasible, as this would further increase the risk for negative returns to farming. The wider implications of the results are that SWC interventions in marginal areas should build on the existing agrodiversity and an understanding of the complex interactions between environmental and socio-economic factors that give rise to differences in farming systems and land management practices. 相似文献
The aim of this study was to investigate the work ability in ageing workers suffering from osteoarthritis (OA), coronary heart disease (CHD) or hypertension (H). One hundred and sixty-six OA and 355 CHD/H outpatients were evaluated. The Work Ability Index (WAI) served for work ability assessment. Patients' results were compared with the results of a control group of 225 healthy young workers. Statistical analysis was performed with ANOVA tests. WAI in female and male CHD/H patients was higher than in OA patients (p < .01), better work ability was related to better education (p < .01), white-collar work (p < .01) and better recreation (p < .01); subjective work ability was determined mostly by the objective health status. The promotion of work ability among workers suffering from advanced age-related diseases should be closely related to the promotion of health. It is indicative to improve occupational education and skills, already at an early stage of a disease. 相似文献
Research into newly developed ballistic vests to be worn by police officers under clothing was carried out with air temperature conditions of +20 °C. A ballistic vest should incorporate protective features, comfort and ergonomics. The thermal strain on users who wore the vests was evaluated as an average and individually, after they had been conditioned in high (+50 °C), low (?40 °C) or neutral (+20 °C) air temperatures, while performing various occupational activities. Research involved six police officers aged 36–42 years, who wore civilian clothing used in moderate environmental conditions. During the tests, physiological parameters (internal temperature, local skin temperatures and amount of sweat secreted) were determined. The ease of doing exercises while wearing the vests, vest service and level of discomfort in use were assessed. Research showed that the vests tested, both as an average and individually, meet the requirements of Standard No. PN-V-87000:2011 (clause 4.5). 相似文献
Objective: Whiplash-associated disorder (WAD), commonly denoted whiplash injury, is a worldwide problem. These injuries occur at relatively low changes of velocity (typically <25 km/h) in impacts from all directions. Rear impacts, however, are the most common in the injury statistics. Females have a 1.5–3 times higher risk of whiplash injury than males.?Improved seat design is the prevailing means of increasing the protection of whiplash injury for occupants in rear impacts. Since 1997, more advanced whiplash protection systems have been introduced on the market, the Saab Active Head Restraint (SAHR) being one of the most prominent. The SAHR—which is height adjustable—is mounted to a pressure plate in the seatback by means of a spring-resisted link mechanism.?Nevertheless, studies have shown that seats equipped with reactive head restraints (such as the SAHR) have a very high injury-reducing effect for males (~60–70%) but very low or no reduction effect for females. One influencing factor could be the position of the head restraint relative to the head, because a number of studies have reported that adjustable head restraints often are incorrectly positioned by drivers.?The aim was to investigate how female and male Saab drivers adjust the seat in the car they drive the most.Methods: The seated positions of drivers in stationary conditions have been investigated in a total of 76 volunteers (34 females, 42 males) who participated in the study. Inclusion criteria incorporated driving a Saab 9–3 on a regularly basis.Results: The majority of the volunteers (89%) adjusted the head restraint to any of the 3 uppermost positions and as many as 59% in the top position.?The average vertical distance between the top of the head and the top of the head restraint (offset) increase linearly with increasing statures, from an average of ?26 mm (head below the head restraint) for small females to an average of 82 mm (head above the head restraint) for large males. On average, the offset was 23 mm for females, which is within a satisfactory range and in accordance with recommendations; the corresponding value for males was 72 mm.?The backset tended to be shorter among female volunteers (on average 27 mm) compared to the male volunteers (on average 44 mm). Moreover, the backset tended to increase with increasing statures.Conclusions: Incorrect adjustment of the head restraint cannot explain the large differences found between the sexes in the effectiveness of the SAHR system. 相似文献
Objective: Real-world driving studies, including those involving speeding alert devices and autonomous vehicles, can gauge an individual vehicle's speeding behavior by comparing measured speed with mapped speed zone data. However, there are complexities with developing and maintaining a database of mapped speed zones over a large geographic area that may lead to inaccuracies within the data set. When this approach is applied to large-scale real-world driving data or speeding alert device data to determine speeding behavior, these inaccuracies may result in invalid identification of speeding. We investigated speeding events based on service provider speed zone data.
Methods: We compared service provider speed zone data (Speed Alert by Smart Car Technologies Pty Ltd., Ultimo, NSW, Australia) against a second set of speed zone data (Google Maps Application Programming Interface [API] mapped speed zones).
Results: We found a systematic error in the zones where speed limits of 50–60 km/h, typical of local roads, were allocated to high-speed motorways, which produced false speed limits in the speed zone database. The result was detection of false-positive high-range speeding. Through comparison of the service provider speed zone data against a second set of speed zone data, we were able to identify and eliminate data most affected by this systematic error, thereby establishing a data set of speeding events with a high level of sensitivity (a true positive rate of 92% or 6,412/6,960).
Conclusions: Mapped speed zones can be a source of error in real-world driving when examining vehicle speed. We explored the types of inaccuracies found within speed zone data and recommend that a second set of speed zone data be utilized when investigating speeding behavior or developing mapped speed zone data to minimize inaccuracy in estimates of speeding. 相似文献