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81.
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Phase-change materials (PCM) can be used to reduce thermal stress and improve thermal comfort for workers wearing protective clothing. The aim of this study was to investigate the effect of PCM in protective clothing used in simulated work situations. We hypothesized that it would be possible to optimize cooling performance with a design that focuses on careful positioning of PCM, minimizing total insulation and facilitating moisture transport. Thermal stress and thermal comfort were estimated through measurement of body heat production, body temperatures, sweat production, relative humidity in clothing and subjective ratings of thermal comfort, thermal sensitivity and perception of wetness. Experiments were carried out using 2 types of PCM, the crystalline dehydrate of sodium sulphate and microcapsules in fabrics. The results of 1 field and 2 laboratory experimental series were conclusive in that reduced thermal stress and improved thermal comfort were related to the amount and distribution of PCM, reduced sweat production and adequate transport of moisture.  相似文献   
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This study analysed the environmental follow-up of a public organisation from a systems thinking approach, including follow-up within different phases of operation and with different environmental management tools. The Swedish Rail Administration (SRA), a public authority responsible for Swedish rail infrastructure, was used as a case organisation. The main aim was to identify different follow-up activities during planning, construction and operation of rail infrastructure. Additional aims were to identify limiting factors for effective environmental follow-up and to provide suggestions on how SRA follow-up can better be used as an organisational learning tool. The follow-up proved to be highly influenced by Environmental Management System and was mainly used for showing compliance with legal regulations or contract requirements. Use of environmental monitoring data was limited to the specific project in which the follow-up was carried out, possibly because of the project-based structure of the organisation following rail deregulation. Theory on organisational learning was applied in the study to discuss how to improve the distribution and use of follow-up data. A more complete ‘organisational memory’ seems to be required for learning from experience and adapting to change.  相似文献   
86.
With respect to nutrients, plants are rather non-homoeostatic while most metazoans have much more confined ranges of nutrient ratios. It was recently highlighted that the homoeostatic ability of microzooplankters lies in between these two extremes. Nevertheless, we know very little on the dynamics of stoichiometric changes. Hence, we investigated how the stoichiometry of the heterotrophic dinoflagellate Oxyrrhis marina is affected (1) during a starvation period and (2) when fed nutrient deplete Rhodomonas salina after having been pre-conditioned on nutrient replete algae and vice versa. We observed that the dinoflagellate was able to maintain its N:P ratio constant over 78 h of starvation. We inferred that under starvation, nitrogen-limited O. marina mainly used fat as energy source while nitrogen-rich individuals also used proteins as fuel in cellular respiration. Further, we showed that O. marina presents resistance to nutrient limitation, with stronger regulation against P-limitation than against N-limitation. This resilience in microzooplankton stoichiometry following food quality stress would have great implications for both top-down (nutrient remineralisation) and bottom-up controls (quality as food).  相似文献   
87.
A case of low atresia of the ileum, diagnosed prenatally by real-time ultrasound scanning, is presented. The ultrasound examination showed progressive distension of intestinal loops, with strong peristaltic movements. The stomach was also distended, presenting as a large cystic area in the upper left abdomen. Real-time ultrasound technique is most advantageous in the diagnosis of fetal ileus. Prenatal diagnosis of fetal intestinal obstruction is of great importance, making early and safe treatment of the newborn possible.  相似文献   
88.
Measuring safety as an outcome variable within the ultra-safe civil aviation industry during periods of deliberate organizational change is a difficult, and often fruitless, task. Anticipating eroding safety processes, based on measuring nothing happening over time, does not adequately capture the true state of an evolving safe system, and this is particularly relevant for leaders and managers in a civil aviation industry responsible for maintaining and improving ultra-safe performance while simultaneously managing demanding strategic business goals.In this paper, I will look at the difficulties of measuring safety as an outcome measure in high reliability organizations (HROs) using the traditional measures of incident and accident reporting during periods of deliberate organizational change inspired by the results from a 3 year longitudinal case study of the Norwegian Air Navigation Services provider – Avinor. I will first review the current safety literature relating to safety management systems (SMSs) used in the civil aviation industry. I will then propose a more holistic model that shifts the focus from the traditional safety monitoring mechanisms of risk analysis and trial and error learning, to the natural interactivity within socio-technical systems as found in high reliability organizations. And finally, I will present a summary of the empirical results of an alternate methodology for measuring perceived changes in safety at the operational level as leading indicators of evolving safety at the organizational level.  相似文献   
89.
Lipids of the Arctic ctenophore Mertensia ovum, collected from Kongsfjorden (Svalbard) in 2001, were analysed to investigate seasonal variability and fate of dietary lipids. Total lipids, lipid classes and fatty acid and alcohol compositions were determined in animals, which were selected according to age-group and season. Changes in lipids of age-group 0 animals were followed during growth from spring to autumn. Total lipids increased from May to September. Lipids as percentage of dry mass were lowest in August indicating their use for reproduction. Higher values occurred in September, which may be due to lipid storage for overwintering. Wax esters were the major lipid class accounting for about 50% of total lipids in age-group 0 animals from July and August. Phospholipids were the second largest lipid fraction with up to 46% in this age-group. The principal fatty acids of M. ovum from all age-groups were 22:6(n-3), 20:5(n-3) and 16:0. Wax ester fatty alcohols were dominated by 22:1(n-11) and 20:1(n-9) followed by moderate proportions of 16:0. The unique feature of M. ovum lipids was the high amount of free fatty alcohols originating probably from the dietary wax esters. In May, free alcohols exhibited the highest mean proportion with 14.6% in age-group 0 animals. We present the first data describing a detailed free fatty alcohol composition in zooplankton. This composition was very different from the alcohol composition of M. ovum wax esters because of the predominance of the long-chain monounsaturated 22:1(n-11) alcohol accounting for almost 100% of total free alcohols in some samples. The detailed lipid composition clearly reflected feeding of M. ovum on the herbivorous calanoid species, Calanus glacialis and C. finmarchicus, the abundant members of the zooplankton community in Kongsfjorden. Other copepod species or prey items seem to be less important for M. ovum.  相似文献   
90.
Lundberg C 《Ambio》2005,34(6):433-439
There is an increasing call for stronger interdisciplinary studies in the Baltic Sea to find solutions to the environmental and social problems associated with eutrophication. Cooperation between experts from the natural sciences, socioeconomics, and management is needed. One way to solve communication problems is to develop a broad conceptual model that comprehensively describes eutrophication and links causes, effects, and the multiple relationships of eutrophication in a visual way. In the present conceptual model, the eutrophication process is divided into i) causes, ii) primary effects, iii) secondary effects, and iv) socioeconomic responses. Each part is described and discussed separately, with links to the other levels and compartments. Possible pathways are shown through the model from natural science to human society, thus inducing management options. Examples of key publications where the causes and effects are observed and studied in the Baltic Sea are listed as examples, and their implications are discussed.  相似文献   
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