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831.
832.
Landscape-geochemical features providing for manifestation of gigantism in herbaceous plants have been revealed in natural habitats in the south of Sakhalin and Kunashir islands. Tall herb assemblages have proved to be associated with geochemical landscapes characterized by reducing (gley or hydrogen sulfide) conditions and increased contents of petroleum hydrocarbons and some trace elements (total and movable forms). A hypothesis is put forward that gigantism in herbaceous plants is manifested in zones of active faults, which serve as a kind of conduits supplying endogenous heat, matter, and water to the root systems.  相似文献   
833.
The composition of pied flycatcher (Ficedula hypoleuca Pall.) nestling diet was studied in the zone of strong pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) and in the background area from 2005 to 2007. The results show that diversity of the diet decreases and prevalence in it of one insect taxon (Lepidoptera) increases near the source of emissions. The proportion of uncharacteristic food objects (orthopterans, herpetobiont invertebrates) and variation in the size of invertebrates brought by parents to their nestlings increase, which is explained by degradation of forest habitats in the polluted area. Pied flycatchers provide nestlings with sufficient quantities of food, but its quality in the polluted zone is lower than in the background area.  相似文献   
834.
Polypropylene (PP) has achieved a dominating position and hence, their consumption increases thereby littering, which lead to environmental pollution. Photodegradation seems to be a better choice because of naturally available sunlight as energy source for degradation. The present work involves the study of the variation of degradation behavior of PP film during tropical summer and winter seasons. The photodegradation is followed by Fourier transform infrared (FTIR) spectroscopic technique. Various indices like hydroxyl, carbonyl, vinylidene, lactones, ester, carboxylic acid and crystallinity are calculated and these values increased after a brief induction period. The variation in the mechanical properties like tensile strength and elongation at break percentages are determined. The scanning electron microscopic (SEM) images of weathered PP showed surface cracks when carbonyl index value increases sharply and the mechanical properties show a sudden decrease. Attempted life time prediction using mathematical models showed that the carbonyl growth is more affected by ultraviolet (UV) and cumulative total solar radiation for PP weathered during summer. The loss in tensile strength of PP weathered during summer is more dependent on the average temperature and the UV portion of the total solar radiation whereas, intensity of UV radiation has profound effect on the tensile strength of PP weathered during winter.  相似文献   
835.
This article aims to describe the characteristics of collective working situations in complex systems – especially those in nuclear power plants – related to common forms of cooperation, in order to improve systems resilience. In addition, we will try to detail some aspects of collective working situations, emphasizing the differences between various forms of control. The similarities between work activities (multi-addressed messages, linkage to regulation, central and peripheral information) are nonetheless exposed. We conclude by proposing a contribution to support systems design, thus facilitating cooperation in teamwork activities.  相似文献   
836.
837.
838.
The occurrence of arsenic in drinking water and its detrimental effects have drawn much attention in recent years. Several studies have been conducted in the deltaic plains of River Ganga, NE part of the India, and in other countries, but no systematic study was conducted in South India on occurrence of arsenic in groundwater. The main aim of this study is to determine the level of arsenic in groundwater and to understand the relation with other geochemical parameters of groundwater in the south-eastern coastal aquifer at Kalpakkam region, India. This region is represented by three different lithologies, viz. charnockites, flood plain alluvium and marine alluvium. Twenty-nine representative samples of groundwater were collected and analysed for major ions, metals and isotopes such as 2H and 18O. In addition, geophysical method was also attempted to understand the subsurface condition. The spatial variation in arsenic (As) indicates that higher concentration was observed around the landfill sites and irrigated regions, which was supported by geochemical, statistical and isotopic inferences. The variation in the As with depth, lithology and sources has been clearly brought out. Though the values of As does not exceed the drinking water permissible limit (10 mg/l), it has reached a near permissible level of 8.7 ppb. Hence, it is essential to understand the geochemical behaviour of As for a proper future management of the water resource in the study area.  相似文献   
839.
Images in children’s books can leave a more lasting impression in young learners’ minds than text. Therefore, it is important for children’s books to use images as a teaching tool, especially regarding global issues such as environmental sustainability. This study examined how the images in nonfiction children’s books approach the topic of sustainability and whether these images support the overall goals of environmental education. We selected seven easy-to-access trade books which yielded 384 images for analysis. Two coders analyzed the images according to the following categories: (a) gender and age, (b) actions of people, (c) depictions of nature, (d) depictions of objects, (e) structures, and (f) habitation. Results show that nearly half of the images (48 %) depicted non-natural objects (16 %) or humans (31 %). One half of the images portrayed humans as consumers. Gender bias was evident, with 33 % of females portrayed as consumers and only 16 % of males portrayed as consumers. Similarly, 12 % of the images with males showed them engaged in recycling behavior, while only 4 % of the images showed females recycling. Of the 32 % of images depicting nature, individual plants rather than ecosystems were portrayed. Depictions of man-made systems predominated the images, a surprising finding. No images established the connection between consumerism and the depletion of natural resources or pollution, and further sustainable actions or lifestyles were not portrayed, implying that consumption is a societal norm. We conclude with recommendations for the use of images in children’s literature focusing on environmental education and sustainability.  相似文献   
840.
In the present paper, the optimum design of a PV system used to operate a water pumping system was determined for Oman. The system design focused on the environmental conditions of Sohar city. The implementation and measurement of the designed system are presented to prove the effectiveness of the proposed system. The results show that the system can provide the required power at peak hours, leading to a substantial reduction in the sizing of the PV system. Consequently, the investment capital costs 2400 USD, and the cost of energy is equal to 0.309 USD/kWh. Furthermore, the results indicate that the system annual yield factor is 2024.66 kWh/kWp and that the capacity factor is 23.05 %, which is encouraging since the latter is typically 21 %. The system capital cost and the cost of energy are worth comparing to a diesel generator. A comparison is made between the proposed system and several others in the literature. The comparison indicated that the system cost of energy is promising.  相似文献   
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