The future of Southern Aral Sea water in Kazakhstan, and of the sequence of mineral evaporitic sediments precipitated since the beginning of the present regression from gypsum to bloed-ite (astrakhanite) was studied. A comparison is made with previous regressive deposits discovered earlier in cores by I.V. Rubanov. Absence of mirabilite deposits in sediments of the eastern basin is attributed to deflation processes during the XIVth century AD. 相似文献
Objective: The aim of this study is to evaluate, through a systematic review of hospital-based studies, the proportion of road traffic injuries and fatalities in sub-Saharan Africa (SSA).
Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology guidelines, we searched the following electronic databases: PubMed, Embase, Africa-Wide Information, Global Health, and Web of Science. Articles were eligible if they measured proportion of road traffic injuries (RTIs) in SSA by using hospital-based studies. In addition, a reference and citation analysis was conducted as well as a data quality assessment.
Results: Up to 2015, there were a total of 83 hospital-based epidemiologic studies, including 310,660 trauma patients and 99,751 RTI cases, in 13 SSA countries. The median proportion of RTIs among trauma patients was 32% (4 to 91%), of which the median proportion of death for the included articles was 5% (0.3 to 41%).
Conclusion: The number of studies evaluating RTI proportions and fatalities in SSA countries is increasing but without the exponential rise expected from World Health Organization calls for research during the Decade of Action for Road Traffic Injuries. Further research infrastructure including standardization of taxonomy, definitions, and data reporting measures, as well as funding, would allow for improved cross-country comparisons. 相似文献
The effect of aluminum sulfate (alum) addition on membrane performance was investigated, with a particular focus on membrane fouling. During initial operation, alum was added and the performance monitored. After terminating alum addition, the transmembrane pressure (TMP), which is indicative of membrane resistance to flow or fouling, increased. Accompanying the increase in TMP was an increase in the organic nonsettleable fraction (colloidal + dissolved) content of the mixed liquor and deterioration of permeate quality and floc strength. Permeate polysaccharide concentrations increased significantly, suggesting a preferential binding of solution polysaccharides by alum. Upon reinitiating alum addition, the TMP only partially recovered, indicating some irreversible fouling, while mixed liquor nonsettleable organic material, permeate quality, and floc strength returned to initial levels. These results suggest that direct alum addition to membrane bioreactors can improve membrane performance by reducing the organic fouling material and improving floc structure and strength. It appears that bulk liquid polysaccharides may contribute to irreversible membrane fouling, and this fraction can be efficiently controlled through the alum addition. 相似文献
This area has a rate of patients with obstructive chronic lung disease that is the highest in Portugal and the second in Europe. Levels of pollution observed in 1985/86 and 1986/87 allowed evaluating the effects of concentrations lower than those that usually cause acute episodes. It was observed that even low levels of strong acidity can be related with lung diseases, when observed simultaneously with appreciable levels of black smoke; climatic factors have a synergetic effect. 相似文献
The current paper investigates the possibility of establishing an empirically based model for predicting the emission rate
of nitrogen oxides (NOx) from oil refinery furnaces, in order to continually track emissions with respect to environmental licence limits. Model
input data were collected by direct stack monitoring using an electrochemical cell NOx analyser, as well as a range of telemetry sensors to obtain refinery process parameters. Principal Component Analysis (PCA),
in conjunction with Partial Least Squares (PLS) regression was then used to build a series of models able to predict NOx emissions from the furnaces. The models produced were proven to be robust, with a relatively high accuracy, and are able
to predict NOx levels over the range of operating conditions which were sampled. It was found that due to structural/operational variations
a separate model is usually required for each furnace. The models can be integrated with the refinery operating system to
predict NOx emission rates on a continuous basis. Two models representing structurally different furnaces are considered in this paper.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
Synthetic biology has the potential for a broad array of applications. However, realization of this potential is challenged by the paucity of relevant data for conventional risk assessment protocols, a limitation due to to the relative nascence of the field, as well as the poorly characterized and prioritized hazard, exposure, and dose–response considerations associated with the development and use of synthetic biology-derived organisms. Where quantitative risk assessment approaches are necessarily to fulfill regulatory requirements for review of products containing genetically modified organisms, this paper reviews one potential avenue for early-stage quantitative risk assessment for biosafety considerations of synthetic biology organism deployment into the environment. Building from discussion from a March 2018 US Army Engineer Research and Development Center workshop on developing such quantitative risk assessment for synthetic biology, this paper reviews the findings and discussion of workshop participants. This paper concludes that, while synthetic biology risk assessment and governance will continue to refine and develop in the coming years, a quantitative framework that builds from existing practice is one potentially beneficial option for risk assessors that must contend with the technology’s limited hazard characterization or exposure assessment considerations in the near term. 相似文献
Journal of Material Cycles and Waste Management - The increased consumption of polymers and the consequent generation of waste requires the development of efficient recycling strategies. In this... 相似文献
Development of polymeric materials that can reduce the reliance on petroleum derived synthetic polymers involves biopolymers such as proteins, starch, cellulose and lipids which can be obtained as agricultural co-products or by-products. Specifically, bioplastics from protein feedstock may have significant advantages over traditional plastics, especially in areas such as packaging, agriculture, horticulture and medical materials. This article focuses on fabricating plastics from whey and albumin proteins and describing properties of plastics made from them. These protein biomasses were plasticized using water and compression molded into plastic samples. Results indicated the importance of water on plasticization during fabrication and on mechanical performance later due to densification during drying. 相似文献