although extensive experimental work has been carried out during the last several years, experimental reaction rate constants are available only for hundreds of compounds. therefore, it is useful to develop a theoretical prediction method, which can be used to obtain estimates of the necessary kinetic parameters. one of the most successful approaches to predict chemical properties starting only...

introduction: estimation of cation exchange capacity (cec) with reliable soil properties can save time and cost. pedotransfer function (ptf) is a common method in estimating certain soil properties (e.g. cec) that has been wieldy used for many years. one of the common techniques that have been used to develop ptfs is multiple linear regressions. in this method, all easily obtained soil properti...

Quantitative structure–activity relationship (QSAR) approaches were used to estimate the volume of distribution (Vd) using an artificial neural network (ANN). The data set consisted of the volume of distribution of 129 pharmacologically important compounds, i.e., benzodiazepines, barbiturates, nonsteroidal anti-inflammatory drugs (NSAIDs), tricyclic anti-depressants and some antibiotics, such a...

In this study the relationship between choosing appropriate descriptors by genetic algorithm to the Polarizability (POL), Molar Refractivity (MR) and Octanol/water Partition Coefficient (LogP) of barbiturates is studied. The chemical structures of the molecules were optimized using ab initio 6-31G basis set method and Polak-Ribiere algorithm with conjugated gradient within HyperChem 8.0 environ...

________________________________________________________________________________ Abstract Artificial neural networks (ANNs) have been shown to be a powerful tool for system modelling in a wide range of applications. In this paper, we focus on the capability of ANNs to predict 305-d milk yield in early lactation of Brown Swiss cattle, based on a few test-day records, and some environmental facto...

Measuring total nitrogen (TN) and total phosphorus (TP) is important in managing heavy polluted urban waters in China. This study uses high spatial resolution IKONOS imagery with four multispectral bands, which roughly correspond to Landsat/TM bands 1–4, to determine TN and TP in small urban rivers and lakes in China. By using Lake Cihu and the lower reaches of Wen-Rui Tang (WRT) River as examp...

Introduction: Due to the health effects caused by airborne pollutants in urban areas, forecasting of air quality parameters is one of the most important topics of air quality research. During recent years, statistical models based on artificial neural networks (ANNs) have been increasingly applied and evaluated for forecasting of air quality. Methods: The development of ANN and multiple linear ...

abstract reference evapotranspiration (eto) is an essential parameter required for proper management of agricultural crop irrigation. eto is influenced by many different hydrological variables and as a result is a very complex procces. eto is usually estimated by empirical or process-orinented models (mathematical relationships) from historical weather data. the need for accurate estimates of e...