The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of m...The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of monitoring as the major factors for predicting the peak particle velocity(PPV). It is established that the PPV is caused by the maximum charge per delay which varies with the distance of monitoring and site geology. While conducting a production blasting, the waves induced by blasting of different holes interfere destructively with each other, which may result in higher PPV than the predicted value with scaled distance regression analysis. This phenomenon of interference/superimposition of waves is not considered while using scaled distance regression analysis. In this paper, an attempt has been made to compare the predicted values of blast-induced ground vibration using multi-hole trial blasting with single-hole blasting in an opencast coal mine under the same geological condition. Further,the modified prediction equation for the multi-hole trial blasting was obtained using single-hole regression analysis. The error between predicted and actual values of multi-hole blast-induced ground vibration was found to be reduced by 8.5%.展开更多
In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu（NO3）·6H2O as source of Eu. The m...In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu（NO3）·6H2O as source of Eu. The materials were characterized by X-ray dif-fraction （XRD）, Raman spectroscopy, Fourier transform infrared spectroscopy （FTIR）, UV-visible diffuse reflectance spectroscopy, scanning electron microscopy （SEM）/energy dispersive X-ray spectroscopy （EDX）, and transmission electron microscopy （TEM）. Indigo carmine （IC） was chosen as a model for organic pollutants and used to evaluate the photocatalytic performance of the photo-catalysts under simulated solar light. Commercial ZrO2 was used as a reference material. XRD and Raman results indicated the for-mation of both tetragonal and monoclinic phase ZrO2 with particle size ranging from 8–30 nm. Multi-element doping had a great in-fluence on the optical responses manifested as red shift in the absorption edge. The highest photocatalytic activity towards IC was observed for the Eu,C,N,S-doped ZrO2 （0.6 mol.%Eu） sample （k=1.09×10–2 min–1）. The commercial ZrO2 showed the lowest photo-degradation activity （k=5.83×10–4 min–1）. The results showed that the control of Eu doping in the C,N,S-ZrO2 was very important in reducing electron-hole recombination. The synergistic effect of Eu, C, N, and S in the ZrO2 matrix led to enhanced utilization of simulated solar energy for the degradation of IC through narrowing of bandgaps.展开更多
Sufficient conditions are found for the existence of similar solutions of the mixed convection flow of a Powell-Eyring fluid over a nonlinear stretching permeable sur- face in the presence of magnetic field. To achiev...Sufficient conditions are found for the existence of similar solutions of the mixed convection flow of a Powell-Eyring fluid over a nonlinear stretching permeable sur- face in the presence of magnetic field. To achieve this, one parameter linear group trans- formation is applied. The governing momentum and energy equations are transformed to nonlinear ordinary differential equations by use of a similarity transformation. These equations are solved by the homotopy analysis method （HAM） to obtain the approximate solutions. The effects of magnetic field, suction, and buoyancy on the Powell-Eyring fluid flow with heat transfer inside the boundary layer are analyzed. The effects of the non- Newtonian fluid （Powell-Eyring model） parameters ε and δon the skin friction and local heat transfer coefficients for the cases of aiding and opposite flows are investigated and discussed. It is observed that the momentum boundary layer thickness increases and the thermal boundary layer thickness decreases with the increase in ε whereas the momentum boundary layer thickness decreases and thermal boundary layer thickness increases with the increase in δ for both the aiding and opposing mixed convection flows.展开更多
Isoalantolactone, a major constituent of Inula racemosa (Compositae) was tested for its antimicrobial action against five bacteria, six human and six plant pathogenic fungi. The lactone showed absolute toxicities at 5...Isoalantolactone, a major constituent of Inula racemosa (Compositae) was tested for its antimicrobial action against five bacteria, six human and six plant pathogenic fungi. The lactone showed absolute toxicities at 500 μg/mL against 3 soil borne phytopathogenic fungi (Gaeu-mannomyces graminis var. tritici, Rhizoctonia cerealis and Phytophthora capsici) with the MICs determined to be 100, 100 and 300 μg/mL, respectively. At the MICs, isoalantolac-tone exhibited its fungi.static nature of toxicity. The lowest fungicidal concentrations of the lactone to G. graminis var. tritici, R. cerealis and P. capsici were shown to be 150, 150 and 350 μg/mL, respectively. Moreover, isoalantolactonc displayed weaker antibacterial activities against Bacillus subtilis, Escherichia coli, Pseudomonas fluorecense, Sarcina lentus and Staphylococcus aureus with MICs of 125, 425, 150, 150 and 100 μg/mL, respectively. The investigation disclosed the strong inhibition of isoalantolactonc to the phytopatho-gcnic fungi,展开更多
Thermoluminescence studies were performed of ZnSe：Tb and ZnSe：（Mn, Tb） phosphors. A method of preparation for ZnSe phosphors doped with Tb and（Mn, Tb） has been discussed. The thermoluminescence（TL）properties o...Thermoluminescence studies were performed of ZnSe：Tb and ZnSe：（Mn, Tb） phosphors. A method of preparation for ZnSe phosphors doped with Tb and（Mn, Tb） has been discussed. The thermoluminescence（TL）properties of these phosphors have been studied from 100 to 370 K temperature after exciting by UV radiation（365 nm）at three uniform heating rates 0.4, 0.6 and 0.9 K/s. The trapping parameters like trap depth, lifetime of electrons and capture cross-section have also been determined using various methods.展开更多
文摘The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades. It uses the maximum charge per delay and distance of monitoring as the major factors for predicting the peak particle velocity(PPV). It is established that the PPV is caused by the maximum charge per delay which varies with the distance of monitoring and site geology. While conducting a production blasting, the waves induced by blasting of different holes interfere destructively with each other, which may result in higher PPV than the predicted value with scaled distance regression analysis. This phenomenon of interference/superimposition of waves is not considered while using scaled distance regression analysis. In this paper, an attempt has been made to compare the predicted values of blast-induced ground vibration using multi-hole trial blasting with single-hole blasting in an opencast coal mine under the same geological condition. Further,the modified prediction equation for the multi-hole trial blasting was obtained using single-hole regression analysis. The error between predicted and actual values of multi-hole blast-induced ground vibration was found to be reduced by 8.5%.
基金Project supported by the National Research Fund of South Africa
文摘In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu（NO3）·6H2O as source of Eu. The materials were characterized by X-ray dif-fraction （XRD）, Raman spectroscopy, Fourier transform infrared spectroscopy （FTIR）, UV-visible diffuse reflectance spectroscopy, scanning electron microscopy （SEM）/energy dispersive X-ray spectroscopy （EDX）, and transmission electron microscopy （TEM）. Indigo carmine （IC） was chosen as a model for organic pollutants and used to evaluate the photocatalytic performance of the photo-catalysts under simulated solar light. Commercial ZrO2 was used as a reference material. XRD and Raman results indicated the for-mation of both tetragonal and monoclinic phase ZrO2 with particle size ranging from 8–30 nm. Multi-element doping had a great in-fluence on the optical responses manifested as red shift in the absorption edge. The highest photocatalytic activity towards IC was observed for the Eu,C,N,S-doped ZrO2 （0.6 mol.%Eu） sample （k=1.09×10–2 min–1）. The commercial ZrO2 showed the lowest photo-degradation activity （k=5.83×10–4 min–1）. The results showed that the control of Eu doping in the C,N,S-ZrO2 was very important in reducing electron-hole recombination. The synergistic effect of Eu, C, N, and S in the ZrO2 matrix led to enhanced utilization of simulated solar energy for the degradation of IC through narrowing of bandgaps.
基金provided by the National Institute of Science and Technology, Berhampurthe Center for Theoretical Studies at Indian Institute of Technology, Kharagpur
文摘Sufficient conditions are found for the existence of similar solutions of the mixed convection flow of a Powell-Eyring fluid over a nonlinear stretching permeable sur- face in the presence of magnetic field. To achieve this, one parameter linear group trans- formation is applied. The governing momentum and energy equations are transformed to nonlinear ordinary differential equations by use of a similarity transformation. These equations are solved by the homotopy analysis method （HAM） to obtain the approximate solutions. The effects of magnetic field, suction, and buoyancy on the Powell-Eyring fluid flow with heat transfer inside the boundary layer are analyzed. The effects of the non- Newtonian fluid （Powell-Eyring model） parameters ε and δon the skin friction and local heat transfer coefficients for the cases of aiding and opposite flows are investigated and discussed. It is observed that the momentum boundary layer thickness increases and the thermal boundary layer thickness decreases with the increase in ε whereas the momentum boundary layer thickness decreases and thermal boundary layer thickness increases with the increase in δ for both the aiding and opposing mixed convection flows.
基金the National Natural Science Foundation of China (Grant Nos. 39725033 and 39970083) and that for Changhong Liu (Grant No. PD-1999-25).
文摘Isoalantolactone, a major constituent of Inula racemosa (Compositae) was tested for its antimicrobial action against five bacteria, six human and six plant pathogenic fungi. The lactone showed absolute toxicities at 500 μg/mL against 3 soil borne phytopathogenic fungi (Gaeu-mannomyces graminis var. tritici, Rhizoctonia cerealis and Phytophthora capsici) with the MICs determined to be 100, 100 and 300 μg/mL, respectively. At the MICs, isoalantolac-tone exhibited its fungi.static nature of toxicity. The lowest fungicidal concentrations of the lactone to G. graminis var. tritici, R. cerealis and P. capsici were shown to be 150, 150 and 350 μg/mL, respectively. Moreover, isoalantolactonc displayed weaker antibacterial activities against Bacillus subtilis, Escherichia coli, Pseudomonas fluorecense, Sarcina lentus and Staphylococcus aureus with MICs of 125, 425, 150, 150 and 100 μg/mL, respectively. The investigation disclosed the strong inhibition of isoalantolactonc to the phytopatho-gcnic fungi,
文摘Thermoluminescence studies were performed of ZnSe：Tb and ZnSe：（Mn, Tb） phosphors. A method of preparation for ZnSe phosphors doped with Tb and（Mn, Tb） has been discussed. The thermoluminescence（TL）properties of these phosphors have been studied from 100 to 370 K temperature after exciting by UV radiation（365 nm）at three uniform heating rates 0.4, 0.6 and 0.9 K/s. The trapping parameters like trap depth, lifetime of electrons and capture cross-section have also been determined using various methods.
