This paper presents the operation of LCL type resonant arc welding power supply with fixed frequency and its steady state mathematical model. Using MathCAD to get the results and compared it to the results of the SP...This paper presents the operation of LCL type resonant arc welding power supply with fixed frequency and its steady state mathematical model. Using MathCAD to get the results and compared it to the results of the SPICE simulative experiment, we verify this mathematical model is correct.展开更多
This paper is about the optimized design and analysis of two solar water pumping systems in which one of the systems is designed with a battery bank and other with a cylindrical water tank for a selected site in Pakis...This paper is about the optimized design and analysis of two solar water pumping systems in which one of the systems is designed with a battery bank and other with a cylindrical water tank for a selected site in Pakistan. The design, sizing, cost analysis and steady state analysis of the proposed systems were done in HOMER and dynamic analysis of the designed system with battery bank was performed in MATLAB/Simulink. The simulations performed in HOMER involved proper mapping of the loads which helped to evaluate the PV panel requirement, inverter rating, batteries (in case of battery based solution), modeling of water tank as a deferrable load (in case of solution based of water tank) and detailed cost analysis for a life time of 25 years. To verify the design of the solar water pumping system with battery bank, a simulation in MATLAB/Simulink for study of dynamic behavior of the overall system was performed which involved mathematical modeling of a PV panel, buckboost converter, inverter, battery bank and motor/pump, a perturb and observe maximum power point tracking algorithm based control system. Analysis was conducted based on the economic results that indicate designed solar water pumping system with water tank would be a cheaper solution as compared to solar water pumping system with a battery bank. This work can be taken as a case study for the understanding and optimized designs of solar water pumping system with battery bank and with cylindrical tank in Pakistani conditions.展开更多
Concentration and source rate of precursor vapors participating in particle formation and subsequent growth were investigated during the Pearl River Delta intensive campaign (PRD2004, October 2004) in southeastern C...Concentration and source rate of precursor vapors participating in particle formation and subsequent growth were investigated during the Pearl River Delta intensive campaign (PRD2004, October 2004) in southeastern China. Four new particle formation event days and a typical non-event day were selected for our analysis. Atmospheric sulphuric acid, the important precursor vapor in nucleation and growth, were simulated with a pseudo steady-state model based on the measurements of SO2, NOx, 03, CO, non-methane hydrocarbon (NMHC) and ambient particle number concentrations as well as modeled photolysis frequencies obtained from measurements. The maximum midday sulphuric acid concentrations vary from 4.53 × 10^7 to 2.17 × 10^8 molecules cm^-3, the corresponding source rate via reaction of OH and SO2 range between 2.37 × 10^6 and 1.16 × 10^7 molecules cm^-3 s^-1. Nucleation mode growth rate was derived from size spectral evolution during the events to be 6.8-13.8 nm h^-1. Based on the growth rate, concentration of the vapors participating in subsequent growth were estimated to vary from 1.32 × 10^8 to 2.80 × 10^8 molecules cm^-3 with corresponding source rate between 7.26 × 10^6 and 1.64 × 10^7 molecules cm^-3 s^-1. Our results show the degree of pollution is larger in PRD. Sulphuric acid concentrations are fairly high and have a close correlation with new particle formation events. Budget analysis shows that sulphuric acid alone is not enough for required growth; other nonvolatile vapors are needed. However, sulphuric acid plays an important role in growth; the contribution of sulphuric acid to growth in PRD is 12.4%-65.2%.展开更多
The physical process of capillary discharge in a PE tube utilized in electro-thermal-chemical(ETC)guns was investigated.ETC guns can enhance the ignition and combustion of propellant in order to reduce the ignition de...The physical process of capillary discharge in a PE tube utilized in electro-thermal-chemical(ETC)guns was investigated.ETC guns can enhance the ignition and combustion of propellant in order to reduce the ignition delay and increase muzzle velocity of the projectile.A key component in ETC gun is the capillary plasma source.In this paper,a 2D steady state model of discharge was built by using magnetic hydrodynamics method.It took the plasma energy balance,material ablation,mass and momentum conservations in a quasi-neutral plasma region into account.Also,the effect of different compositions and PE concentration distribution were considered.In order to evaluate the validation of this model,the simulation results are compared with former works.展开更多
Debris flow is one of the most destructive water related mass movements that affects the development of mountain terrains.A reliable assessment of debris flow susceptibility requires adequate data,but in most developi...Debris flow is one of the most destructive water related mass movements that affects the development of mountain terrains.A reliable assessment of debris flow susceptibility requires adequate data,but in most developing countries like India,there is a dearth of such extensive scientific records.This study presents a novel approach for assessing debris flow using the analytical network process(ANP)in data insufficient regions.A stretch of hill road between Kumburvayal and Vadakaunchi along the Kodaikkanal-Palani Traffic Corridor(M171)was considered for this study.Five significant factors including the nature of slope forming materials,hydraulic conductivity,slope,vegetation,and drainage density were identified from intense field surveys and inspections in order to assess the susceptibility of the terrain to debris flow.This model endorsed the interdependencies between the selected factors.The resulting debris flow susceptibility map delineated regions highly prone to debris flow occurrences,which constituted nearly 23%of the selected road stretch.展开更多
文摘This paper presents the operation of LCL type resonant arc welding power supply with fixed frequency and its steady state mathematical model. Using MathCAD to get the results and compared it to the results of the SPICE simulative experiment, we verify this mathematical model is correct.
文摘This paper is about the optimized design and analysis of two solar water pumping systems in which one of the systems is designed with a battery bank and other with a cylindrical water tank for a selected site in Pakistan. The design, sizing, cost analysis and steady state analysis of the proposed systems were done in HOMER and dynamic analysis of the designed system with battery bank was performed in MATLAB/Simulink. The simulations performed in HOMER involved proper mapping of the loads which helped to evaluate the PV panel requirement, inverter rating, batteries (in case of battery based solution), modeling of water tank as a deferrable load (in case of solution based of water tank) and detailed cost analysis for a life time of 25 years. To verify the design of the solar water pumping system with battery bank, a simulation in MATLAB/Simulink for study of dynamic behavior of the overall system was performed which involved mathematical modeling of a PV panel, buckboost converter, inverter, battery bank and motor/pump, a perturb and observe maximum power point tracking algorithm based control system. Analysis was conducted based on the economic results that indicate designed solar water pumping system with water tank would be a cheaper solution as compared to solar water pumping system with a battery bank. This work can be taken as a case study for the understanding and optimized designs of solar water pumping system with battery bank and with cylindrical tank in Pakistani conditions.
基金China National Basic Research and Development Program (Grant Nos. 2002CB410801, 2002CB211605) National Natural Science Foundation of China (Grant No. 40405025).
文摘Concentration and source rate of precursor vapors participating in particle formation and subsequent growth were investigated during the Pearl River Delta intensive campaign (PRD2004, October 2004) in southeastern China. Four new particle formation event days and a typical non-event day were selected for our analysis. Atmospheric sulphuric acid, the important precursor vapor in nucleation and growth, were simulated with a pseudo steady-state model based on the measurements of SO2, NOx, 03, CO, non-methane hydrocarbon (NMHC) and ambient particle number concentrations as well as modeled photolysis frequencies obtained from measurements. The maximum midday sulphuric acid concentrations vary from 4.53 × 10^7 to 2.17 × 10^8 molecules cm^-3, the corresponding source rate via reaction of OH and SO2 range between 2.37 × 10^6 and 1.16 × 10^7 molecules cm^-3 s^-1. Nucleation mode growth rate was derived from size spectral evolution during the events to be 6.8-13.8 nm h^-1. Based on the growth rate, concentration of the vapors participating in subsequent growth were estimated to vary from 1.32 × 10^8 to 2.80 × 10^8 molecules cm^-3 with corresponding source rate between 7.26 × 10^6 and 1.64 × 10^7 molecules cm^-3 s^-1. Our results show the degree of pollution is larger in PRD. Sulphuric acid concentrations are fairly high and have a close correlation with new particle formation events. Budget analysis shows that sulphuric acid alone is not enough for required growth; other nonvolatile vapors are needed. However, sulphuric acid plays an important role in growth; the contribution of sulphuric acid to growth in PRD is 12.4%-65.2%.
文摘The physical process of capillary discharge in a PE tube utilized in electro-thermal-chemical(ETC)guns was investigated.ETC guns can enhance the ignition and combustion of propellant in order to reduce the ignition delay and increase muzzle velocity of the projectile.A key component in ETC gun is the capillary plasma source.In this paper,a 2D steady state model of discharge was built by using magnetic hydrodynamics method.It took the plasma energy balance,material ablation,mass and momentum conservations in a quasi-neutral plasma region into account.Also,the effect of different compositions and PE concentration distribution were considered.In order to evaluate the validation of this model,the simulation results are compared with former works.
基金This study was supported by DST-SERB under fast track scheme(No.SR/FTP/ETA-0062/2011)The authors would like to acknowledge with thanks,the financial support rendered by DST for the research.
文摘Debris flow is one of the most destructive water related mass movements that affects the development of mountain terrains.A reliable assessment of debris flow susceptibility requires adequate data,but in most developing countries like India,there is a dearth of such extensive scientific records.This study presents a novel approach for assessing debris flow using the analytical network process(ANP)in data insufficient regions.A stretch of hill road between Kumburvayal and Vadakaunchi along the Kodaikkanal-Palani Traffic Corridor(M171)was considered for this study.Five significant factors including the nature of slope forming materials,hydraulic conductivity,slope,vegetation,and drainage density were identified from intense field surveys and inspections in order to assess the susceptibility of the terrain to debris flow.This model endorsed the interdependencies between the selected factors.The resulting debris flow susceptibility map delineated regions highly prone to debris flow occurrences,which constituted nearly 23%of the selected road stretch.