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41.
The Elbow River watershed in Alberta covers an area of 1,238 km2 and represents an important source of water for irrigation and municipal use. In addition to being located within the driest area of southern Canada, it is also subjected to considerable pressure for land development due to the rapid population growth in the City of Calgary. In this study, a comprehensive modeling system was developed to investigate the impact of past and future land-use changes on hydrological processes considering the complex surface–groundwater interactions existing in the watershed. Specifically, a spatially explicit land-use change model was coupled with MIKE SHE/MIKE 11, a distributed physically based catchment and channel flow model. Following a rigorous sensitivity analysis along with the calibration and validation of these models, four land-use change scenarios were simulated from 2010 to 2031: business as usual (BAU), new development concentrated within the Rocky View County (RV-LUC) and in Bragg Creek (BC-LUC), respectively, and development based on projected population growth (P-LUC). The simulation results reveal that the rapid urbanization and deforestation create an increase in overland flow, and a decrease in evapotranspiration (ET), baseflow, and infiltration mainly in the east sub-catchment of the watershed. The land-use scenarios affect the hydrology of the watershed differently. This study is the most comprehensive investigation of its nature done so far in the Elbow River watershed. The results obtained are in accordance with similar studies conducted in Canadian contexts. The proposed modeling system represents a unique and flexible framework for investigating a variety of water related sustainability issues.  相似文献   
42.
This study presents the emission factor of gaseous pollutants(CO, CO_2, and NO X) from on-road tailpipe measurement of 14 passenger cars of different types of fuel and vintage. The trolley equipped with stainless steel duct, vane probe velocity meter, flue gas analyzer, Nondispersive infra red(NDIR) CO_2 analyzer, temperature, and relative humidity(RH) sensors was connected to the vehicle using a towing system. Lower CO and higher NO X emissions were observed from new diesel cars(post 2010) compared to old cars(post 2005), which implied that new technological advancement in diesel fueled passenger cars to reduce CO emission is a successful venture,however, the use of turbo charger in diesel cars to achieve high temperature combustion might have resulted in increased NO X emissions. Based on the measured emission factors(g/kg), and fuel consumption(kg), the average and 95% confidence interval(CI) bound estimates of CO, CO_2,and NO X from four wheeler(4W) in Delhi for the year 2012 were 15.7(1.4–37.1), 6234(386–12,252),and 30.4(0.0–103) Gg/year, respectively. The contribution of diesel, gasoline and compressed natural gas(CNG) to total CO, CO_2 and NO X emissions were 7:84:9, 50:48:2 and 58:41:1respectively. The present work indicated that the age and the maintenance of vehicle both are important factors in emission assessment therefore, more systematic repetitive measurements covering wide range of vehicles of different age groups, engine capacity, and maintenance level is needed for refining the emission factors with CI.  相似文献   
43.
Persistence of dicofol residues in cotton lint seed, and soil   总被引:1,自引:0,他引:1  
A supervised field trial was conducted at the CCS Haryana Agricultural University, Hisar to assess the residues of dicofol on cotton, during Kharif season, 2008. Dicofol (Kelthane 18.5EC) was applied at 500 g a.i./ha (T(1)) and 1,000 g a.i./ha T(2)) after 105 days of sowing of cotton crop (Varity Cotton/H-1226). Soil samples were collected on 0 (1 h after treatment), 3, 7, 10, 15, 30, and 60 days after spray and cotton samples were collected at harvest. Samples were processed and residues were quantified by GC-ECD system equipped with capillary column. Limit of detection and limit of quantification (LOQ) were 0.001 and 0.010 mg kg(?-1), respectively, for soil and LOQ for cotton lint and seed was 0.020 mg kg(?-1). Initial residues of 0.588 and 1.182 mg kg(?-1) in soil reached below detectable level (BDL) of 0.010 mg kg(?-1) in T(1) and to the level of BDL (0.010 mg kg(?-1)) in T(2) at harvest (60 days after treatment). In 60 days, residues dissipated almost completely (100 and >99%) in both the treatments. Half-life period was calculated as 8.57 days at single dose and 8.69 days at double dose in soil. Residues of dicofol were detected in cotton lint to the levels of 0.292 and 0.653 mg kg(?-1) and in seed 0.051 and 0.090 mg kg(?-1) in T(1) and T(2) doses, respectively at harvest. Residues in cotton seed were below MRL value of 0.01 mg kg(?-1) in both the doses.  相似文献   
44.
Abstract: Climate change, particularly the projected changes to precipitation patterns, is likely to affect runoff both regionally and temporally. Extreme rainfall events are expected to become more intense in the future in arid urban areas and this will likely lead to higher streamflow. Through hydrological modeling, this article simulates an urban basin response to the most intense storm under anthropogenic climate change conditions. This study performs an event‐based simulation for shorter duration storms in the Flamingo Tropicana (FT) watershed in Las Vegas, Nevada. An extreme storm, defined as a 100‐year return period storm, is selected from historical records and perturbed to future climatic conditions with respect to multimodel multiscenario (A1B, A2, B1) bias corrected and spatially disaggregated data from the World Climate Research Programme's (WCRP's) database. The cumulative annual precipitation for each 30‐year period shows a continuous decrease from 2011 to 2099; however, the summer convective storms, which are considered as extreme storms for the study area, are expected to be more intense in future. Extreme storm events show larger changes in streamflow under different climate scenarios and time periods. The simulated peak streamflow and total runoff volume shows an increase from 40% to more than 150% (during 2041‐2099) for different climate scenarios. This type of analysis can help evaluate the vulnerability of existing flood control system and flood control policies.  相似文献   
45.
Preimplantation genetic diagnosis for aneuploidy screening (PGD-AS) using sequential in situ hybridization was applied for aneuploidy testing in 276 couples with 282 ART cycles. Patients with advanced maternal age (AMA, n = 147), recurrent implantation failure (RIF, n = 48), repeated early spontaneous abortion (RSA, n = 32) and abnormal gamete cell morphology (AGCM, n = 55) including macrocephal sperm forms or cytoplasmic granular oocytes were included. Embryo biopsy was performed on day 3 in a calcium–magnesium–free medium by using a noncontact diode laser system. After fixation and enzymatic treatment, fluorescent in situ hybridization (FISH) was carried out on 1147 blastomeres with specific probes for chromosomes 13, 16, 18, 21 and 22 for AMA group, 13, 18, 21, X and Y for AGCM group and 13, 16, 18, 21, 22, X and Y for RIF and RSA groups respectively. The overall chromosomal abnormality rate in analyzed embryos was 40.9%, with no significant difference between AMA, RIF and RSA groups (p > 0.05). However, AGCM group presented a higher rate of chromosomal aneuploidies (57.4%) than the other three groups (p < 0.01). A total of 84% biopsied embryos presented cleavage in 24 h and embryo transfer was realized in 278 cycles. In four cycles, no chromosomally normal embryo was found for embryo transfer. A total of 88 pregnancies (31.6%) were achieved, 19.3% resulted in abortion and 63 healthy births were obtained, with a total of 93 babies born. Aneuploidy testing in couples with poor prognosis undergoing ART cycles is a useful tool to increase the chance of ART success. Furthermore, abnormal gamete cell morphology should be considered one of the major indications for PGD in ART programs as high aneuploidy rates were observed in this group. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
46.
Environmental Chemistry Letters - Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries....  相似文献   
47.

This review highlights and summarizes the impact of different fabrication processes on the efficiency of dye-sensitized solar cells (DSSCs). Energy conversion efficiency of cell depends upon semiconductor, sensitizer, electrolyte, and counter electrode. Efficiency of DSSCs can be enhanced by properly selecting the optimum significance of various parameters of fabrications process. Major challenges of these solar cells are non-vegetal, noxious, extreme sensitizers. Application of natural dyes in this field plays a significant role. An optimized CdSe-TiO2 photoanode showed a power conversion efficiency (PCE) of 13.29% and short circuit current density of 15.30 mA cm?2 for the DSSC. Power conversion efficiency of 3.26% was achieved by using TTO electrode for DSSC device that is ascribed to the improved electrical and optical properties due to doping with Ta element. Absorbance of betalain was shown in the visible range of 530–535 nm for betanin while 450–559 nm for anthocyanin pigment. The natural dyes are economical, readily available, and environmentally friendly. This compilation would be beneficial for researchers working on dye solar cell.

  相似文献   
48.
Residue levels of endosulfan were determined in cabbage heads after being sprayed with a formulation containing the insecticide and upon storage at room temperature (15–27°C) and in a refrigerator (2–5°C). The half-life was calculated to be 4.8 and 5.5 days. Peeling removed the residues by 92%. Similarly, washing and washing followed by cooking removed 72% and 97% residue in cabbage stored at room temperature. These treatments were slightly less effective for samples stored in a refrigerator. Household processes such as peeling, washing, and washing followed by cooking should be regular practice before the vegetables are used.  相似文献   
49.
Environmental Science and Pollution Research - Abandoning shredded waste tyre rubber (WTR) in cement-based mixes facilitates safe waste tyre disposal and conserves the natural resources used in...  相似文献   
50.
Artificially roughened solar air heater has been topic in research for the last 30 years. Prediction of heat transfer and fluid flow processes of an artificially roughened solar air heater can be obtained by three approaches: theoretical, experimental, and computational fluid dynamics (CFD). This article provides a comprehensive review of the published literature on the investigations of artificially roughened solar air heater. In the present article, an attempt has been made to present holistic view of various roughness geometries used for creating artificial roughness in solar air heater for heat transfer enhancement. This extensive review reveals that quite a lot of work has been reported on design of artificially roughened solar air heater by experimental approach but only a few studies have been done by theoretical and CFD approaches. Finally this article presents a comparative study of thermo-hydraulic performance of 21 different types of artificial roughness geometries attached on the absorber plate of solar air heater in terms of thermo-hydraulic performance parameter. Heat transfer and friction factor correlations developed by various investigators for different types of artificially roughened solar air heaters have also been reported in this article.  相似文献   
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