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A supervised open field trial was conducted to evaluate the dissipation pattern and risk assessment of flubendiamide in gherkin fruits following foliar application of Fame 480 SC at 60 and 120 g a.i.?ha?1. Samples of gherkin fruits were drawn at different time intervals and quantified by HPLC-DAD. The maximum initial deposits of flubendiamide on gherkin were found to be 0.79 and 1.52 mg kg?1, respectively, at recommended and double the recommended doses. The dissipation pattern of flubendiamide followed a first-order kinetics with half-lives of 1.87 to 2.16 days at 60 and 120 g a.i.?ha?1, respectively. The limit of quantification of flubendiamide and desiodo flubendiamide was observed to be 0.01 mg kg?1 for gherkin fruit and soil substrates. Theoretical maximum residue contribution (TMRC) for flubendiamide was calculated and found to be well below the maximum permissible intake (MPI) on gherkin fruits. Thus, the application of flubendiamide at the recommended dose on gherkin fruits presents no human health risks and safe to consumers.  相似文献   
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Time series analysis of coal mine accident experience   总被引:1,自引:0,他引:1  
This study investigates several forecasting techniques that can be useful to mine safety managers for studying mine accident rate behavior. Three time series models were studied for extrapolation of accident rates. These models are applied to historical accident incidence data from a coal mine. Further, a method is presented for evaluating the three models for the selection of an appropriate model. For this particular mine application, it is concluded that the more complex Box-Jenkins ARMA model as well as first order autoregressive model do not give better results than the simple exponential smoothing model. However, when the random variations or autocorrelations in the accident experience rates between periods are different, the models may predict differently. As such, specific models must be developed for each mine on the basis of statistical analysis of the mine accident experience data over time. Moreover, the importance of incorporating human judgement to interpret the results of statistical forecasting cannot be overemphasized. Integration of policy or operating changes, which may impact mine safety performance, with statistical forecasting techniques is essential to arrive at a realistic prediction of future performance.  相似文献   
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ABSTRACT: Machine learning techniques are finding more and more applications in the field of forecasting. A novel regression technique, called Support Vector Machine (SVM), based on the statistical learning theory is explored in this study. SVM is based on the principle of Structural Risk Minimization as opposed to the principle of Empirical Risk Minimization espoused by conventional regression techniques. The flood data at Dhaka, Bangladesh, are used in this study to demonstrate the forecasting capabilities of SVM. The result is compared with that of Artificial Neural Network (ANN) based model for one‐lead day to seven‐lead day forecasting. The improvements in maximum predicted water level errors by SVM over ANN for four‐lead day to seven‐lead day are 9.6 cm, 22.6 cm, 4.9 cm and 15.7 cm, respectively. The result shows that the prediction accuracy of SVM is at least as good as and in some cases (particularly at higher lead days) actually better than that of ANN, yet it offers advantages over many of the limitations of ANN, for example in arriving at ANN's optimal network architecture and choosing useful training set. Thus, SVM appears to be a very promising prediction tool.  相似文献   
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Supply to electrical pumpsets for irrigation purposes accounts for about 25% of the total electricity sold in India. The number of electrical pumpsets is expected to increase from 8.5 million in 1989–90 to 10.5 million in 1994–95. Low load factors (10–12%) and low densities (1–4 pumpsets/km2) mean large investments for the electric utility in order to supply electricity for irrigation. It is reported that there exists a potential to save at least 10% of the electricity supplied to this sector by means of simple retrofit measures. However, conditions in the field pose constraints to such retrofits. Some of those constraints are highlighted in this paper. It is also suggested that immediate attempts be made to ensure that all new connections are energy efficient. This paper suggests that the additional cost incurred to ensure new energy efficient connections and to maintain retrofit energy efficient pumpsets must be looked on as a necessary cost for energy efficiency.  相似文献   
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Ensuring an adequate, reliable, clean, and affordable water supply for citizens and industries requires informed, long-range water supply planning, which is critically important for water security. A balance between water supply and demand must be considered for a long-term plan. However, water demand projections are often highly uncertain. Climate change could impact the hydrologic processes, and consequently, threaten water supply. Thus, understanding the uncertainties in future water demand and climate is critical for developing a sound water supply plan. In Illinois, regional water supply planning attempts to explore the impacts of future water demand and climate on water supply using scenario analyses and hydrologic modeling. This study is aimed at developing a water supply planning framework that considers both future water demand and climate change impacts. This framework is based on the Soil and Water Assessment Tool to simulate the watershed hydrology and conduct scenario analyses that consider the uncertainties in both future water demand and climate as well as their impacts on water supply. The framework was applied to water supply planning efforts in the Kankakee River watershed. The Kankakee River watershed model was calibrated and validated to observed streamflow records at four long-term United States Geological Survey streamflow gages. Because of the many model parameters involved, the calibration process was automated and was followed by a manual refinement, resulting in good model performance. Long-range water demand projections were prepared by the Illinois State Water Survey. Six future water demand scenarios were established based on a suite of assumptions. Climate scenarios were obtained from the Coupled Model Intercomparison Projection Phase 5 datasets. Three representative concentration pathways (RCPs), RCP2.6, RCP4.5, and RCP8.5, are used in the study. The scenario simulation results demonstrated that climate change appears to have a greater impact on water availability in the study area than water demand. The framework developed in this study can also be used to explore the impacts of uncertainties of water demand and climate on water supply and can be extended to other regions and watersheds.  相似文献   
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In this study, the Tsunami-caused deterioration of soil and groundwater quality in the agricultural fields of coastal Nagapattinam district of Tamilnadu state in India is presented by analyzing their salinity and sodicity parameters. To accomplish this, three sets of soil samples up to a depth of 30cm from the land surface were collected for the first six months of the year 2005 from 28 locations and the ground water samples were monitored from seven existing dug wells and hand pumps covering the study region at intervals of 3 months. The EC and pH values of both the soil and ground water samples were estimated and the spatial and temporal variability mappings of these parameters were performed using the geostatistical analysis module of ArcGIS((R)). It was observed that the spherical semivariogram fitted well with the data set of both EC and pH and the generated kriged maps explained the spatial and temporal variability under different ranges of EC and pH values. Further, the recorded EC and pH data of soil and ground water during pre-Tsunami periods were compared with the collected data and generated variability soil maps of EC and pH of the post-Tsunami period. It was revealed from this analysis that the soil quality six months after the Tsunami was nearing the pre-Tsunami scenario (EC< 1.5dSm(-1); pH<8), whereas the quality of ground water remained highly saline and unfit for irrigation and drinking. These observations were compared with the ground scenarios of the study region and possible causes for such changes and the remedial measures for taking up regular agricultural practices are also discussed.  相似文献   
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Subsequent to the 1997 promulgation of the Federal Reference Method (FRM) for monitoring fine particulate matter (PM2.5) in ambient air, U.S. Environmental Protection Agency (EPA) received reports that the DOW 704 diffusion oil used in the method's Well Impactor Ninety-Six (WINS) fractionator would occasionally crystallize during field use, particularly under wintertime conditions. Although the frequency of occurrence on a nationwide basis was low, uncertainties existed as to whether crystallization of the DOW 704 oil may adversely affect a sampling event's data quality. In response to these concerns, EPA and the State of Connecticut Department of Environmental Protection jointly conducted a series of specialized tests to determine whether crystallized oil adversely affected the performance of the WINS fractionator. In the laboratory, an experimental setup used dry ice to artificially induce crystallization of the diffusion oil under controlled conditions. Using primary polystyrene latex calibration aerosols, standard size-selective performance tests of the WINS fractionator showed that neither the position nor the shape of the WINS particle size fractionation curve was substantially influenced by the crystallization of the DOW 704 oil. No large particle bounce from the crystallized impaction surface was observed. During wintertime field tests, crystallization of the DOW 704 oil did not adversely affect measured PM2.5 concentrations. Regression of measurements with crystallized DOW 704 versus liquid dioctyl sebacate (DOS) oil produced slope, intercept, and R2 values of 0.98, 0.1, and 0.997 microg/m3, respectively. Additional field tests validated the use of DOS as an effective impaction substrate. As a result of these laboratory and field tests, DOS oil has been approved by EPA as a substitute for DOW 704 oil. Since the field deployment of DOS oil in 2001, users of this alternative oil have not reported any operational problems associated with its use in the PM2.5 FRM. Limited field evaluation of the BGI very sharp cut cyclone indicates that it provides a viable alternative to the WINS fractionator.  相似文献   
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The Coordinating Research Council held its 15th workshop in April 2005, with nearly 90 presentations describing the most recent mobile source-related emissions research. In this paper, the authors summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles (with an emphasis in this workshop on particle emissions), effects of fuels on emissions, evaluation of in-use emissions control programs, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.  相似文献   
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