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281.
对四种同脂发热自燃性进行了试验研究,采用回归分析方法,建立了环境温度与油脂发热诱导期之间的定量关系式,即lgT/a/t+b,提出油脂自燃性能可用a和b两参数描述。研究表明,碘值与油脂自燃性能常数a和b存在密切关系,可分别用对数和直线方程表示。 相似文献
282.
The introduction of automobile catalysts has raised environmental concern, as this pollution control technology is also an
emission source for platinum group elements (PGE). The main aim of this study was to assess soil and grass PGE concentrations
in soils adjacent to five road networks. The soil and grass samples were collected from four distances at each site; they
were 0, 1, 2 and 5 m from the road edges. The maximum soil Pt, Rh and Pd concentrations were measured at the road perimeters.
Pd concentrations were much higher than Pt or Rh, possibly due to differences in its use, emission and/or soil chemistry.
Rh and Pt soil concentrations accounted for 66 and 34% (P < 0.01) of the variability observed, respectively, in their plant concentrations. Grass Pd concentrations had no relationship
with its total soil concentrations. 相似文献
283.
Climate change models for California's Sierra Nevada predict greater inter-annual variability in precipitation over the next 50 years. These increases in precipitation variability coupled with increases in nitrogen deposition from fossil fuel consumption are likely to result in increased productivity levels and significant increases in forest understory fuel loads. Higher understory plant biomass contributes to fuel connectivity and may increase future fire size and severity in the Sierra Nevada. The objective of this research was to develop and test a model to determine how changing precipitation and nitrogen deposition levels affect shrub and herb biomass production, and to determine how often prescribed fire would be needed to counter increasing fuel loads. Model outputs indicate that under an increasing precipitation scenario significant increases in shrub and herb biomass occur that can be counteracted by decreasing the fire return interval to 10 years. Under a scenario with greater inter-annual variability in precipitation and increased nitrogen deposition, implementing fire treatments at an interval equivalent to the historical range of 15–30 years maintains understory vegetation fuel loads at levels comparable to the control. 相似文献
284.
285.
The effect of textile mill wastewater on germination, delay index, physiological growth parameters, and plant pigments of two cultivars of chickpea was studied. The aim of this study was to evaluate the suitability of textile mill wastewater (treated and untreated) at different concentrations (0, 6.25, 12.5, 25, 50, 75, and 100%) for irrigational purposes. The textile effluent did not show any inhibitory effect on seed germination at a lower concentration (6.25%). The other reported plant parameters (delay index, root length, shoot length, dry weight, chlorophyll, and carotenoid) also followed a similar trend. Seeds germinated in 100% effluents but did not survive for longer periods. It has also been concluded that the effect of the textile effluent is cultivar-specific, and due care should be taken before using the textile mill wastewater for irrigation purposes. 相似文献
286.
《Process Safety and Environmental Protection》2014,92(5):406-411
Management of a plant alarm system has been identified as one of the key safety issues because of disasters caused by alarm floods. When a chemical plant is at abnormal state, an alarm system must provide useful information to operators as the third layer of an independent protection layer (IPL). Therefore, a method of designing a plant alarm system is important for plant safety. Because the plant is maintained in the plant lifecycle, the alarm system for the plant should be properly managed through the plant lifecycle. To manage changes, the design rationales of the alarm system should be explained explicitly. This paper investigates a logical and systematic alarm system design method that explicitly explains the design rationales from know-why information for proper management of changes through the plant lifecycle. In the method, the module structure proposed by Hamaguchi et al. (2011) to assign a fault origin to be distinguished is extended. Using modules to investigate the sets of alarm sensors and the alarm limits setting for first alarm alternative signals to distinguish the fault origin, an alarm system design method is proposed. Also, the completeness of fault propagation for a branch of the cause–effect model as the plant model is explained. Using the modules and the set of fault origins to be distinguished by the alarm system, we try to explicitly explain the design rationales of the alarm system. 相似文献
287.
This article examines the utilization characteristics and importance of woody biomass resources in the rural-urban fringe
zones of Botswana. In the literature for Africa, attention has been given to the availability and utilization of biomass in
either urban or rural environments, but the rural-urban fringe has been neglected. Within southern Africa, this neglect is
not justified; the rural-urban fringe, not getting the full benefits available in urban environments in Botswana, has developed
problems in woody biomass availability and utilization that require close attention. In this article, socioeconomic data on
the importance of woody biomass in the Batlokwa Tribal Territory, on the rural-urban fringe of Gaborone, Botswana, were collected
together with ecologic data that reveal the utilization characteristics and potential for regrowth of woody biomass. The analysis
of these results show that local woody biomass is very important in the daily lives of communities in the rural-urban fringe
zones and that there is a high level of harvesting. However, there is no effort in planning land use in the tribal territory
to either conserve this resource or provide alternatives to its utilization. The future of woody biomass resources in Botswana’s
rural-urban fringe is uncertain. The investigators recommend that a comprehensive policy for the development of the rural-urban
fringe consider the importance of this resource. The neglect of this resource will have far-reaching implications on the livelihoods
of residents as well as the environment in this zone. 相似文献
288.
dentification of groups that are similar in their floristic composition and structure (habitat types) is essential for conservation
and forest managers to allocate high priority areas and to designate areas for reserves, refuges, and other protected areas.
In this study, the use of indigenous knowledge for the identification of habitat types in the field was compared against an
ecological characterization of habitat types, including their species composition obtained by using classification and ordination
techniques for a tropical landscape mosaic in a rural Mayan area of Quintana Roo, Mexico. Plant diversity data calculated
from 141 sampled sites chosen randomly on a vegetation class’s thematic map obtained by multispectral satellite image classification
were used for this propose. Results indicated high similarity in the categorization of vegetation types between the Mayan
classification and those obtained by cluster and detrended correspondence analysis. This suggests that indigenous knowledge
has a practical use and can be comparable to that obtained by using science-based methods. Finally, identification and mapping
of vegetation classes (habitat types) using satellite image classification allowed us to discriminate significantly different
species compositions, in such a way that they can provide a useful mechanism for interpolating diversity values over the entire
landscape. 相似文献
289.
首先探讨了特许权经营后政府对城市污水处理厂实行质量管制的必要性;然后,针对当前对污水处理服务进行质量管制存在的普遍问题,通过分析政府管制机构与污水处理厂基于质量的博弈行为,提出了对城市污水处理厂实行有效质量管制的几点建议。 相似文献
290.
Uptake and translocation of metformin, ciprofloxacin and narasin in forage- and crop plants 总被引:6,自引:0,他引:6
Transfer of bioactive organic compounds from soil to plants might represent animal and human health risks. Sewage sludge and manure are potential sources for bioactive compounds such as human- and veterinary drugs. In the present study, uptake of the anti-diabetic compound, metformin, the antibiotic agent ciprofloxacin and the anti-coccidial narasin in carrot (Daucuscarota ssp. sativus cvs. Napoli) and barley (Hordeumvulgare) were investigated. The pharmaceuticals were selected in order to cover various chemical properties, in addition to their presence in relevant environmental matrixes. The root concentration factors (RCF) found in the present study were higher than the corresponding leaf concentration factors (LCF) for the three test pharmaceuticals. The uptake of metformin was higher compared with ciprofloxacin and narasin for all plant compartments analyzed. Metformin was studied more explicitly with regard to uptake and translocation in meadow fescue (Festucapratense), three other carrot cultivars (D.carota ssp. sativus cvs. Amager, Rothild and Nutri Red), wheat cereal (Triticumaestivum) and turnip rape seed (Brassicacampestris). Uptake of metformin in meadow fescue was comparable with uptake in the four carrot cultivars (RCF 2-10, LCF approximately 1.5), uptake in wheat cereals were comparable with barley cereals (seed concentration factors, SCF, 0.02-0.04) while the accumulation in turnip rape seeds was as high as 1.5. All three pharmaceuticals produced negative effects on growth and development of carrots when grown in soil concentration of 6-10 mg kg−1 dry weight. 相似文献