A combination of cascade aeration and biofiltration systems is one of the available ecological treatments to reduce the concentration of pollutants in grey water and resolve the problem of acute water crisis supply in...A combination of cascade aeration and biofiltration systems is one of the available ecological treatments to reduce the concentration of pollutants in grey water and resolve the problem of acute water crisis supply in Iraq. An experimental constructed grey water treatment system has been installed at AI-Mustansiriya University, College of Engineering during the period from January to December 2012. The performance of the treatment schemes has been evaluated by monitoring the quality of the raw grey water and effluent on these samples which are： pH, COD （chemical oxygen demand）, TSS （total suspended solids）, TDS （total dissolved solids）, PO43 （phosphates）, NO32 （nitrates）, NO （nitrites）, oils ＆ grease, NH3-N （ammonia-nitrogen） and some anions and cations. The average removal rate of COD was more than 60% that of NH3-N, NO3-N, NO2-N, TDS and TSS that were 55%-89%, 59%-74%, 79%-98%, 17%-52% and 51%-87%, respectively. Also the results indicate that the removal efficiency of ions concentrations such as Ca2＋, Mg2＋, Na＋, K＋ were 78%-96%, 73%-97%, 14%-47% and 44%-64%, respectively, while for cations such as SO42, Cl and PO43-, the removal efficiencies were 33%-79%, 27%-61% and 81%-99%, respectively. Finally oils ＆ grease was 79%-88%.展开更多
This paper analyzes the effects of the voltage across insulator of 69 kV and 24 kV lines installed on the same pole. The case studies illustrated the lightning strike to direct top pole and mid span of ground wire usi...This paper analyzes the effects of the voltage across insulator of 69 kV and 24 kV lines installed on the same pole. The case studies illustrated the lightning strike to direct top pole and mid span of ground wire using the ATP-EMTP （Alternative Transient Program-Electromagnetic Transient Program）. The results found that when lightning strike the voltage across the 69 kV line insulator at mid span is 1.55 times and 1.34 times higher than at top pole when the front time is 0.25/100μs and 10/350 μs, respectively. When lightning strike the voltage across the 24 kV line at mid span is 1.04 times and 0.64 times higher than at top pole when the front time is 0.25/100μs and 10/350μs, respectively. So the effect of lightning strike is more severe at mid span than at the direct top pole, especially for the 69 kV insulator.展开更多
The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor an...The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive, as for the upwind type, the inner and the outer rotational armatures, respectively, in keeping the rotational torque counter-balanced between both wind rotors/armatures. The unique rotational behaviors of the tandem wind rotors and the fundamental performances of the unit have been discussed at the previous paper. Continuously, this paper investigates experimentally and numerically the flow condition around the wind rotors to know the flow interactions between the front and the rear wind rotors, and optimizes the blade profile in the front wind rotor. The front blade should work fruitfully at the larger radius and had better not work at the smaller radius for giving plenty of wind energy to the rear wind rotor, taking account of the flow interaction between both wind rotors.展开更多
The authors have invented a superior wind power unit, which is composed of tandem wind rotors and double rotational armature type generator without the traditional stator. This unit is called ＂intelligent wind power ...The authors have invented a superior wind power unit, which is composed of tandem wind rotors and double rotational armature type generator without the traditional stator. This unit is called ＂intelligent wind power unit＂. At upwind type unit, the large-sized front wind rotor and the small-sized rear wind rotor drive the inner and the outer rotational armatures respectively, in keeping the rotational torque counter-balance between both wind rotors/armatures. This paper discusses the acoustic noise emitted from the tandem wind rotors. As for tandem wind rotors, the tip vortex shedding from the front wind rotor may make a loud acoustic noise if the vortex attacks the rear wind rotor. Intelligent wind power unit, however, has no chance to increase the acoustic noise level by the tip vortex because the diameter of the front wind rotor is reasonably larger than the diameter of the rear wind rotor. The vorticity generated in the boundary layer on the blade can be observed obviously at wake flow and can be evaluated quantitatively at flow conditions measured by a hot-wire anemometer at a wind tunnel. The flow conditions have shown that the radial and axial components of vorticities contribute to emit the acoustic noise.展开更多
文摘A combination of cascade aeration and biofiltration systems is one of the available ecological treatments to reduce the concentration of pollutants in grey water and resolve the problem of acute water crisis supply in Iraq. An experimental constructed grey water treatment system has been installed at AI-Mustansiriya University, College of Engineering during the period from January to December 2012. The performance of the treatment schemes has been evaluated by monitoring the quality of the raw grey water and effluent on these samples which are： pH, COD （chemical oxygen demand）, TSS （total suspended solids）, TDS （total dissolved solids）, PO43 （phosphates）, NO32 （nitrates）, NO （nitrites）, oils ＆ grease, NH3-N （ammonia-nitrogen） and some anions and cations. The average removal rate of COD was more than 60% that of NH3-N, NO3-N, NO2-N, TDS and TSS that were 55%-89%, 59%-74%, 79%-98%, 17%-52% and 51%-87%, respectively. Also the results indicate that the removal efficiency of ions concentrations such as Ca2＋, Mg2＋, Na＋, K＋ were 78%-96%, 73%-97%, 14%-47% and 44%-64%, respectively, while for cations such as SO42, Cl and PO43-, the removal efficiencies were 33%-79%, 27%-61% and 81%-99%, respectively. Finally oils ＆ grease was 79%-88%.
文摘This paper analyzes the effects of the voltage across insulator of 69 kV and 24 kV lines installed on the same pole. The case studies illustrated the lightning strike to direct top pole and mid span of ground wire using the ATP-EMTP （Alternative Transient Program-Electromagnetic Transient Program）. The results found that when lightning strike the voltage across the 69 kV line insulator at mid span is 1.55 times and 1.34 times higher than at top pole when the front time is 0.25/100μs and 10/350 μs, respectively. When lightning strike the voltage across the 24 kV line at mid span is 1.04 times and 0.64 times higher than at top pole when the front time is 0.25/100μs and 10/350μs, respectively. So the effect of lightning strike is more severe at mid span than at the direct top pole, especially for the 69 kV insulator.
文摘The authors have invented the superior wind power unit, which is composed of the tandem wind rotors and the double rotational armature type generator without the traditional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive, as for the upwind type, the inner and the outer rotational armatures, respectively, in keeping the rotational torque counter-balanced between both wind rotors/armatures. The unique rotational behaviors of the tandem wind rotors and the fundamental performances of the unit have been discussed at the previous paper. Continuously, this paper investigates experimentally and numerically the flow condition around the wind rotors to know the flow interactions between the front and the rear wind rotors, and optimizes the blade profile in the front wind rotor. The front blade should work fruitfully at the larger radius and had better not work at the smaller radius for giving plenty of wind energy to the rear wind rotor, taking account of the flow interaction between both wind rotors.
文摘The authors have invented a superior wind power unit, which is composed of tandem wind rotors and double rotational armature type generator without the traditional stator. This unit is called ＂intelligent wind power unit＂. At upwind type unit, the large-sized front wind rotor and the small-sized rear wind rotor drive the inner and the outer rotational armatures respectively, in keeping the rotational torque counter-balance between both wind rotors/armatures. This paper discusses the acoustic noise emitted from the tandem wind rotors. As for tandem wind rotors, the tip vortex shedding from the front wind rotor may make a loud acoustic noise if the vortex attacks the rear wind rotor. Intelligent wind power unit, however, has no chance to increase the acoustic noise level by the tip vortex because the diameter of the front wind rotor is reasonably larger than the diameter of the rear wind rotor. The vorticity generated in the boundary layer on the blade can be observed obviously at wake flow and can be evaluated quantitatively at flow conditions measured by a hot-wire anemometer at a wind tunnel. The flow conditions have shown that the radial and axial components of vorticities contribute to emit the acoustic noise.
