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1.
Blasting is a widely used technique for rock fragmentation in opencast mines and tunneling projects. Ground vibration is one of the most environmental effects produced by blasting operation. Therefore, the proper prediction of blast-induced ground vibrations is essential to identify safety area of blasting. This paper presents a predictive model based on gene expression programming (GEP) for estimating ground vibration produced by blasting operations conducted in a granite quarry, Malaysia. To achieve this aim, a total number of 102 blasting operations were investigated and relevant blasting parameters were measured. Furthermore, the most influential parameters on ground vibration, i.e., burden-to-spacing ratio, hole depth, stemming, powder factor, maximum charge per delay, and the distance from the blast face were considered and utilized to construct the GEP model. In order to show the capability of GEP model in estimating ground vibration, nonlinear multiple regression (NLMR) technique was also performed using the same datasets. The results demonstrated that the proposed model is able to predict blast-induced ground vibration more accurately than other developed technique. Coefficient of determination values of 0.914 and 0.874 for training and testing datasets of GEP model, respectively show superiority of this model in predicting ground vibration, while these values were obtained as 0.829 and 0.790 for NLMR model.  相似文献   
2.
The isotopic compositions of commercially available herbicides were analyzed to determine their respective 15N, 13C and 37Cl signatures for the purposes of developing a discrete tool for tracing and identifying non-point source contaminants in agricultural watersheds. Findings demonstrate that of the agrochemicals evaluated, chlorine stable isotopes signatures range between δ37Cl = −4.55‰ and +3.40‰, whereas most naturally occurring chlorine stable isotopes signatures, including those of road salt, sewage sludge and fertilizers, vary in a narrow range about the Standard Mean Ocean Chloride (SMOC) between −2.00‰ and +1.00‰. Nitrogen stable isotope values varied widely from δ15N = −10.86‰ to +1.44‰ and carbon stable isotope analysis gave an observed range between δ13C = −37.13‰ and −21.35‰ for the entire suite of agro-chemicals analyzed. When nitrogen, carbon and chlorine stable isotope analyses were compared in a cross-correlation analysis, statistically independent isotopic signatures exist suggesting a new potential tracer tool for identifying herbicides in the environment.  相似文献   
3.
A hydrometric, hydrochemical and environmental isotopic study was conducted to identify the source and origin of observed springs on the foot of the hillock abutting the left flank of the Gollaleru earthen dam, Nandyal, Andhra Pradesh, India. Water samples (springs, reservoir water and groundwater) in and around the dam area were collected and analyzed for environmental isotopes (\(\updelta ^{18}\!\hbox {O}\), \(\updelta ^{2}\hbox {H}\) and \(^{3}\hbox {H}\)) and hydrochemistry. Reservoir level, spring discharges and physico-chemical parameters (temperature, electrical conductivity, pH, etc.) were monitored in-situ. Isotopic results indicated that the source of springs is from the Owk reservoir and groundwater contribution to the springs is insignificant. Based on hydrometric observations, it is inferred that the springs might be originated from the reservoir level of 209 m amsl. It is found that the lower spring discharges were derived from diffuse sources (seepage) which could be a mixture of reservoir water and the groundwater, while the relatively higher spring discharges were resulted from concentrated sources (leakage) from the reservoir. Thus, the study portraits the usefulness of isotope techniques in understanding the dam seepage/leakage related problems.  相似文献   
4.
5.
This paper evaluates the performance of three soft computing techniques, namely Gene-Expression Programming (GEP) (Zakaria et al 2010), Feed Forward Neural Networks (FFNN) (Ab Ghani et al 2011), and Adaptive Neuro-Fuzzy Inference System (ANFIS) in the prediction of total bed material load for three Malaysian rivers namely Kurau, Langat and Muda. The results of present study are very promising: FFNN (R 2 = 0.958, RMSE = 0.0698), ANFIS (R 2 = 0.648, RMSE = 6.654), and GEP (R 2 = 0.97, RMSE = 0.057), which support the use of these intelligent techniques in the prediction of sediment loads in tropical rivers.  相似文献   
6.
In FRW space time Brans-Dicke theory is developed for two cases: (i) the vacuum and (ii) the perfect fluid model. The field equations are transformed into a much simpler form under a change of time co-ordinates and then the solutions are determined for the above cases. An equation of statep =/3 (radiation) is assumed in the case of perfect fluid.  相似文献   
7.
Ages of redeye round herring Etrumeus whiteheadi were estimated with associated errors and used to infer life-history information, such as age composition, age-at-maturity and instantaneous mortality rate. Samples were collected in November 2005 during a research survey aimed at estimating the biomass of spawning pelagic fish off South Africa’s west and south coasts. Replicate age estimates obtained from sagittal otoliths were collected with slight bias and relatively high precision. A von Bertalanffy model describing growth of the combined sexes, including juveniles, was Lt = 20.41(1 ? e?0.41(t ? 1.92)). Kimura’s likelihood ratio test revealed no statistically significant differences between growth parameters of males and females. Results suggested that otolith length is a better predictor of age than otolith weight. Maturity estimates for E. whiteheadi were similar to those previously documented.  相似文献   
8.
Water-budget components and the vertical conductance were determined for Lowry (Sand Hill) Lake in north-central Florida, USA. In this type of lake, which interacts with both the surface-water and groundwater systems, the inflow components are precipitation, surface-water inflow, groundwater inflow, and direct runoff (i.e. overland flow), and the outflow components are evaporation, groundwater outflow, and surface-water outflow. In a lake and groundwater system that is typical of many karst lakes in Florida, a large part of the groundwater outflow occurs by means of vertical leakage through an underlying confining unit to a deeper, highly transmissive aquifer called the upper Floridan aquifer. The water-budget component that represents vertical leakage to the upper Floridan aquifer was calculated as a residual using the water-budget equation. For the 13 month period from August 1994 to August 1995, relative to the surface area of the lake, rainfall at Lowry Lake was 1.55 m yr−1, surficial aquifer inflow was 0.79 m yr−1, surface-water inflow was 1.92 m yr−1, and direct runoff was 0.01 m yr−1. Lake evaporation was 1.11 m yr−1, and surface-water outflow was 1.61 m yr−1. The lake stage increased 0.07 m yr−1, and the vertical leakage to the upper Floridan aquifer was 1.48 m yr−1. Surficial aquifer outflow from the lake was negligible. At Lowry Lake, vertical leakage is a major component of the water budget, comprising about 35% of the outflow during the study period. The vertical conductance (KV/b), a coefficient that represents the average of the vertical conductances of the hydrogeologic units between the bottom of a lake and the top of the upper Floridan aquifer, was determined to be 2.51 × 10−4 day−1 for Lowry Lake.  相似文献   
9.
Spawning biology and spawn fishery of three valuable species of Indian major carps,Catla catla, Labeo rohita andCirrhinus mrigala, in the lower Halda River, Bangladesh, were studied in 1978. The major carps spawned only in the Sonairchar oxbow-bend from April to June on or near the dates of the full moon and the new moon. The tide was then at its highest level, and there was heavy flood water runoff from the hill region with sharp increases in water level, turbidity and current velocity, as well as decreases in water temperature, dissolved oxygen, and hydrogen ion concentration. These three heterogeneric species, as a result of parallelism or convergence in evolution, overlap in their environmental requirements for spawning. The nursery ground of the major carp fry spawned in the Halda River was found to be in the Bay of Bengal. The brood stock origin is suspected to be at the Shankha River, 40 miles south of the Karnafuli River. The spawn fishery in the Halda River was intensive but inefficient. Engineering works and water management schemes are threatening the spawning habitat.  相似文献   
10.
High‐resolution soil and groundwater monitoring was performed to assess the long‐term impacts of bioremediation using bioaugmentation with a dechlorinating microbial consortium (and sodium lactate as the electron donor) in a well‐characterized trichloroethene (TCE) dense nonaqueous phase liquid (DNAPL) source area. Monitoring was performed up to 3.7 years following active bioremediation using a high‐density monitoring network that included several discrete interval multi‐level sampling wells. Results showed that despite the absence of lactate, lactate fermentation transformation products, or hydrogen, biogeochemical conditions remained favorable for the reductive dechlorination of chlorinated ethenes. In locations where soil data showed that TCE DNAPL sources persisted, local contaminant rebound was observed in groundwater, whereas no rebound or continuous decreases in chlorinated ethenes were observed in locations where DNAPL sources were treated. While ethene levels measured 3.7 years after active treatment suggested relatively low (2 to 30%) dechlorination of the parent TCE and daughter products, carbon stable isotope analysis showed that the extent of complete dechlorination was much greater than indicated by ethene generation and that the estimated first‐order rate constant describing the complete dechlorination of TCE at 3.7 years following active bioremediation was approximately 3.6 y–1. Overall, results of this study suggest that biological processes may persist to treat TCE for years after cessation of active bioremediation, thereby serving as an important component of remedial treatment design and long‐term attenuation.  相似文献   
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