Original Research Paper
Alireza Arab-Amiri; Fereydoun Sharifi; Abolghasem Kamkar-Rouhani
Abstract
The need for clean groundwater resources to have sustainable development in a country is undoubted. Due to the importance and high quality of karstic waters in supplying water in Iran especially in Shahrood city, it is attempted in this research work to recognize and explore karstic waters in southwest ...
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The need for clean groundwater resources to have sustainable development in a country is undoubted. Due to the importance and high quality of karstic waters in supplying water in Iran especially in Shahrood city, it is attempted in this research work to recognize and explore karstic waters in southwest of Tepal area, Shahrood. For this purpose, integration of the results obtained from the methods of vertical electrical sounding (VES) and resistivity profiling has been used in this research work. The VES surveys have been performed in 10 sounding points using the Schlumberger array with electrode separations of a maximum 500 meters. The resistivity profiling surveys using dipole-dipole electrode array with 75m electrode spacing and dipole steps 1 to 8 have been carried out along four lines having a length of more than four kilometers in the study area. Then, one-dimensional (1-D) modeling and interpretation of the sounding results using master curves and IX1D software, and two-dimensional (2-D) modeling and interpretation of the profiling results using Res2DINV have been made. As a result of the interpretation and integration of the results, karstic water zones in the study area have been recognized, and based on that, suitable locations for drilling to access and extract karstic groundwater have been introduced.
Case Study
Maysam Abedi; Kiomars Mosazadeh; Hamid Dehghani; Ahmad MadanchiZare
Abstract
This paper describes an efficient edge-preserved regularization algorithm for downward continuation of magnetic data in detection of unexploded ordnance (UXO). The magnetic anomalies arising from multi-source UXO can overlap at a height over the ground surface, while causative sources may not be readily ...
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This paper describes an efficient edge-preserved regularization algorithm for downward continuation of magnetic data in detection of unexploded ordnance (UXO). The magnetic anomalies arising from multi-source UXO can overlap at a height over the ground surface, while causative sources may not be readily separated due to low level of signal-to-noise ratio of the observed data. To effectively the magnetic method work in the cleanup stage of contaminated area with UXO, the magnetic anomalies of UXO sources should be enhanced in order to separate the locations of different sources. The stable downward continuation of magnetic data can increase the signal-to-noise ratio which subsequently causes the separation of UXO sources by enhancing the signals. We formulate the downward continuation as a linear ill-posed deconvolution problem in this study. To obtain a reasonable downward continued field, it is stabilized in a Fourier domain to regularize the downward solution using the edge-preserved (or total-variation) algorithm. The L-curve method is used to choose the optimum value of the regularization parameter which is a trade-off between the misfit and the solution norms in the cost function of optimization problem. A synthetic magnetic field is constructed from isolated multi-source UXO anomalies, whose results show that the data can be stably downward continued by the proposed method. Likewise, a field data set has been provided to demonstrate the capability of the applied method in UXO detection.
Case Study
S. Hadi Hosseini; Mohammad Ataie; Hamid Aghababaie
Abstract
In this paper, after collecting the rock samples from eight mines and one high way slope, the tests for determination of dry density, Uniaxial Compressive Strength, tensile Strength (Brazilian Test), elastic modulus, Schmidt hammer rebound number have been done on samples. In addition, in order to calculating ...
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In this paper, after collecting the rock samples from eight mines and one high way slope, the tests for determination of dry density, Uniaxial Compressive Strength, tensile Strength (Brazilian Test), elastic modulus, Schmidt hammer rebound number have been done on samples. In addition, in order to calculating the mean size of rock grains, quartz content, hardness and abrasivity, a thin sections of each rock have been studied. Then, the rock samples have been drilled using actual pneumatic top hammer drilling machine with 3½ inches diameter cross type bit. The regression analyses showed that Brazilian tensile strength (R2=0.81), uniaxial compressive strength (R2=0.77) and Schmidt hammer rebound (R2=0.73) are the most effective parameters on drilling rate and have a partly good correlation with drilling rate.
Case Study
SUJIT KUMAR MANDAL; N.K Bhagat; M.M Singh
Abstract
Transmission of blast waves is a complex phenomenon and the characteristics vary with blast design parameters and geo-technical properties of medium. Frequency of vibration and triggering component for structural excitation generally quantifies safe vibration magnitude. At closer distance or higher elevations ...
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Transmission of blast waves is a complex phenomenon and the characteristics vary with blast design parameters and geo-technical properties of medium. Frequency of vibration and triggering component for structural excitation generally quantifies safe vibration magnitude. At closer distance or higher elevations than the blast locations, vertical or transverse component will be the first arrival to trigger the sensor for monitoring and at far off distances longitudinal component triggers the sensor to monitor. Similarly, for shorter depth of blastholes and wider blast geometries, vertical or transverse component triggers the sensor to monitor even for longer distances of measurement. Analyzing the cause of such occurrence, the paper firstly puts forward a mathematical model to illustrate the same. Thereafter, considering single-degree of freedom for dynamic analysis of structures, the paper communicates that incident particle velocity exiting a structure to vibrate should be considered to limit vibration magnitude for safety of structures.
Case Study
Hamid Khoshdast
Abstract
A new parametric model was developed for predicting cut point of hydraulic classifiers. The model directly uses operating parameters including pulp flowrate, feed particle size characteristics, pulp solids content, solid density and particles retention time in the classification chamber and also covers ...
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A new parametric model was developed for predicting cut point of hydraulic classifiers. The model directly uses operating parameters including pulp flowrate, feed particle size characteristics, pulp solids content, solid density and particles retention time in the classification chamber and also covers uncontrollable errors using calibration constants. The model applicability was first verified using a bench scale classifier and then, validated at industrial scale for a coal classifier. Results showed that the new model can predict the cut point more precisely compared to the conventional Masliyah model, i.e. the accuracy values of 80% and 37% for the new and Masliyah models, respectively. Sensitivity study showed that the model was extremely sensitive to the particle size distribution of feed while being least sensitive to the particles retention time.
Short Communication
Saeed Alishahi; Ahmad Darban; Mahmood Abdollahi
Abstract
Since a high toxicity of cyanide which use as a reagent in the gold processing plant, thiosulfate has been recognized as a environmental friendly reagent for leaching of gold from ore. After gold leaching process it's important for recovery of gold from solution using adsorption or extraction methods, ...
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Since a high toxicity of cyanide which use as a reagent in the gold processing plant, thiosulfate has been recognized as a environmental friendly reagent for leaching of gold from ore. After gold leaching process it's important for recovery of gold from solution using adsorption or extraction methods, One of these methods is activated carbon.The loading of gold from industrial thiosulfate solution that obtained from Zarshuran gold plant-Takab-Iran, onto activated carbon have been investigated. The affecting variables of the adsorption of gold on the carbon included, temperature, concentration of gold, size of activated carbon, pH and the ratio of amount of activated carbon to the volume of solution. The results have shown that at low concentration of gold, effective loading can be achieved at pH 10.5. The size of activated carbon has a significant effect on the loading of gold. In this research the recovery of gold on activated carbon has been predicted using artificial neural network. For this purpose temperature, pH, the proportion of solution volume to weight of activated carbon, gold concentration and time of adsorption were taken as input parameters, whereas, the recovery of gold on activated carbon from thiosulfate solution was considered as an output parameter. The network with LMBP algorithm with two hidden layer were used and the topology 5-4-13-1 showed the best ability for prediction.Moreover sensitive analyze were indicated parameters pH and temperature have substantial influence on adsorption.
