Horizontal directional drilling (HDD) is widely used in soil and rock engineering. In a variety of conditions, it is necessary to estimate the torque required for performing the reaming operation. Nevertheless, there is not presently a convenient method to accomplish this task. In this paper, to overcome this difficulty based on the basic concepts of rock engineering systems (RES), a model for ...

Objective: Environmental and economic challenges resulting from the application of nitrogen fertilizers have increased Concerns about its productivity in the agricultural systems. Thus an experiment in order to investigate ability SSM-Wheat for simulation growth and yield of wheat (cultivar N-87-20) in response to fertilizer nitrogen in the direction decrease Pollution environm...

Objective: Environmental and economic challenges resulting from the application of nitrogen fertilizers have increased Concerns about its productivity in the agricultural systems. Thus an experiment in order to investigate ability SSM-Wheat for simulation growth and yield of wheat (cultivar N-87-20) in response to fertilizer nitrogen in the direction decrease Pollution environm...

Drought is a climate phenomenon which might occur in any climate condition and all regions on the earth. Effective drought management depends on the application of appropriate drought indices. Drought indices are variables which are used to detect and characterize drought conditions. In this study, it was tried to predict drought occurrence, based on the standard precipitation index (SPI), usin...

The temporal prediction of the solar radiation is very important for the operation of any solar energy system technology and completing data set. Based on meteorological parameters, the artificial neural network (ANN) can bring a technical solution for the prediction problems. In this paper, we developed an ANN for the south Tunisian climate to predict global solar radiation. Five years of reco...

background: water is considered as the main source of life but water resources are limited and nonrenewable. different factors have caused groundwater to decrease. therefore, modeling and predicting groundwater level is of great importance. methods: monthly groundwater level data of about 20 years (october 1991 to february 2012) from the hamadan-bahar plain, west of iran were used based on peiz...

the acidity constants (pka) of thirty four (34) ;-substituted carboxylic acids in aqueous solution havebeen calculated using conductor-like polarizable continuum (c-pcm) solvation model. the gasphaseenergies at the density functional theory (dft-mpw1pw91) and solvation energies athartree fock (hf) are combined to estimate the pka values which are very close to the experimentalvalues where, and ...

in recent decades, the developments of artificial intelligence to predict hydrologic models have been widely used. in this study, the ability of artificial neural network(ann) models for modeling and predict the biological oxygen demand (bod) is located on the karun river in west iran were evaluated. to improve the simulation results, wavelet analysis was used as a hybrid model. bod index month...

The acidity constants (pKa) of thirty four (34) ;-substituted carboxylic acids in aqueous solution havebeen calculated using conductor-like polarizable continuum (C-PCM) solvation model. The gasphaseenergies at the Density Functional Theory (DFT-MPW1PW91) and solvation energies atHartree Fock (HF) are combined to estimate the pKa values which are very close to the experimentalvalues where, and ...