Coal washing plants are usually fed from various sources. Coals include different combinations which should be considered for increasing the plant proficiency. Thus different methods have been used to enrich various c...Coal washing plants are usually fed from various sources. Coals include different combinations which should be considered for increasing the plant proficiency. Thus different methods have been used to enrich various coal types. In this study, Alborz-Sharghi coal washing plant was investigated which is fed from five coalmines. The optimum recovery was achieved for all coal types individually through experimental design. The controllable operation parameters in the experiments were collector dosage,frother dosage, solid percent content and particle size. The other parameters such as impeller speed,pH, conditioning time and flotation time were kept constant for all experiments. The optimum combination of coals was also specified. The results show that the optimum recovery for coal blends is 91.2%which shows much improvement relative to the plant conditions.展开更多
Many papers exploiting the various MPPT （maximum power point tracking） techniques in PV （photovoltaic） applications, from the simple to the most complicated, can be found in literature. However, these techniques m...Many papers exploiting the various MPPT （maximum power point tracking） techniques in PV （photovoltaic） applications, from the simple to the most complicated, can be found in literature. However, these techniques may not always be easy to implement in industrial applications. The main challenge of this paper is to model and implement the P ＆ O （perturb and observe） algorithm in a low-cost PV-powered pumping system. To that end, a comparative investigation of the performance characteristics of the most popular MPPT methods, such as FOCV （fractional open circuit voltage）, FSCC （fractional short circuit current）, FLC （fuzzy logic control）, ANN （artificial neural network） and INC （incremental conductance） is presented. This analysis is helpful to highlight the relevance of the P ＆ O technique taking better account of complexity, difficulty of implementation and cost considerations in water pumping applications. The targeted PV-powered pumping system is based on a single-phase induction motor supplied by a three-phase inverter controlled by the DTC （direct torque control） technique. This stand-alone PV system is dedicated to water pumping, especially in rural areas that have no access to national grids but have sufficient amount of solar radiation. Simulation modeling （Matlab/Simulink） and experimental results are presented to demonstrate the relevance of the system.展开更多
This study examines the state of liveability in emerging urban centers of Ago-lwoye and Ijebu-Igbo in Ogun State. The study used primary and secondary data. Both descriptive and inferential statistical techniques were...This study examines the state of liveability in emerging urban centers of Ago-lwoye and Ijebu-Igbo in Ogun State. The study used primary and secondary data. Both descriptive and inferential statistical techniques were used to analyze research questions that bother on urban liveability. Results of the analyses show that in the two urban centres the following are not in very good condition： neighborhood road quality, garbage collection, state of cleanliness, street light, state of security, pollution, water supply, drainage system, and power supply. Most of the residents are not satisfied with the state of liveability in Ago-Iwoye and Ijebu-Igbo towns. Statistical test result shows among others that there is no significant variation in the level of urban dwellers＇ satisfaction with their neighbourhood condition. In order to improve urban liveability in the two urban centres, government should provide all necessary infrastructural facilities and services. While roads are to be improved and maintained, electricity and water supply should be provided. Community associations should also be encouraged. They should be more involved in activities that will improve liveability in the urban centre. They should constitute themselves as pressure groups, working on the government to improve the liveability of the urban centre.展开更多
Thieno[3,2-b]thiophene(TT)monomers end-capped with 3,4-ethylenedioxythiophene(EDOT)moieties are electropolymerized to formπ-conjugated polymers with distinct electrochromic(EC)properties.Steric and electronic factors...Thieno[3,2-b]thiophene(TT)monomers end-capped with 3,4-ethylenedioxythiophene(EDOT)moieties are electropolymerized to formπ-conjugated polymers with distinct electrochromic(EC)properties.Steric and electronic factors(electron donor and acceptor substituents)in the side groups of the TT core,as well as the structure of the polymer backbone strongly affect the electrochemical and optical properties of the polymers and their electrochromic characteristics.The studied polymers show low oxidation potentials,tunable from-0.78 to+0.30 V(vs.Fc/Fc^+)and the band gaps from 1.46 to 1.92 eV and demonstrate wide variety of color palettes in polymer films in different states,finely tunable by structural variations in the polymer backbone and the side chains.EC materials of different colors in their doped/dedoped states have been developed(violet,deep blue,light blue,green,brown,purple-red,pinkish-red,orange-red,light gray,cyan and colorless transparent).High optical contrast(up to 79%),short response time(0.57-0.80 s),good cycling stability(up to 91%at 2000 cycles)and high coloration efficiency(up to 234.6 cm2C^(-1))have been demonstrated and the influence of different factors on the above parameters of EC polymers have been discussed.展开更多
By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is pr...By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light.The device consists of a working electrode with planar integration of photovoltaic(PV)and electrochromic(EC)elements on one electrode,a platinum counter electrode and a redox electrolyte comprising Br^-/Br_3^-couple.A high transmittance modulation of 41%at 582 nm is obtained.Electrical energy converted from light is not only sufficient to drive the device,but also can be outputted to the external circuit.展开更多
文摘Coal washing plants are usually fed from various sources. Coals include different combinations which should be considered for increasing the plant proficiency. Thus different methods have been used to enrich various coal types. In this study, Alborz-Sharghi coal washing plant was investigated which is fed from five coalmines. The optimum recovery was achieved for all coal types individually through experimental design. The controllable operation parameters in the experiments were collector dosage,frother dosage, solid percent content and particle size. The other parameters such as impeller speed,pH, conditioning time and flotation time were kept constant for all experiments. The optimum combination of coals was also specified. The results show that the optimum recovery for coal blends is 91.2%which shows much improvement relative to the plant conditions.
文摘Many papers exploiting the various MPPT （maximum power point tracking） techniques in PV （photovoltaic） applications, from the simple to the most complicated, can be found in literature. However, these techniques may not always be easy to implement in industrial applications. The main challenge of this paper is to model and implement the P ＆ O （perturb and observe） algorithm in a low-cost PV-powered pumping system. To that end, a comparative investigation of the performance characteristics of the most popular MPPT methods, such as FOCV （fractional open circuit voltage）, FSCC （fractional short circuit current）, FLC （fuzzy logic control）, ANN （artificial neural network） and INC （incremental conductance） is presented. This analysis is helpful to highlight the relevance of the P ＆ O technique taking better account of complexity, difficulty of implementation and cost considerations in water pumping applications. The targeted PV-powered pumping system is based on a single-phase induction motor supplied by a three-phase inverter controlled by the DTC （direct torque control） technique. This stand-alone PV system is dedicated to water pumping, especially in rural areas that have no access to national grids but have sufficient amount of solar radiation. Simulation modeling （Matlab/Simulink） and experimental results are presented to demonstrate the relevance of the system.
文摘This study examines the state of liveability in emerging urban centers of Ago-lwoye and Ijebu-Igbo in Ogun State. The study used primary and secondary data. Both descriptive and inferential statistical techniques were used to analyze research questions that bother on urban liveability. Results of the analyses show that in the two urban centres the following are not in very good condition： neighborhood road quality, garbage collection, state of cleanliness, street light, state of security, pollution, water supply, drainage system, and power supply. Most of the residents are not satisfied with the state of liveability in Ago-Iwoye and Ijebu-Igbo towns. Statistical test result shows among others that there is no significant variation in the level of urban dwellers＇ satisfaction with their neighbourhood condition. In order to improve urban liveability in the two urban centres, government should provide all necessary infrastructural facilities and services. While roads are to be improved and maintained, electricity and water supply should be provided. Community associations should also be encouraged. They should be more involved in activities that will improve liveability in the urban centre. They should constitute themselves as pressure groups, working on the government to improve the liveability of the urban centre.
基金Shenzhen Key Laboratory of Organic Optoelectromagnetic Functional Materials of Shenzhen Science and Technology Plan(ZDSYS20140509094114164)the Shenzhen Peacock Program(KQTD2014062714543296)+6 种基金Shenzhen Science and Technology Research Grant(JCYJ20140509093817690)Nanshan Innovation Agency Grant(KC2015ZDYF0016A)Guangdong Key Research Project(2014B090914003,2015B090914002)Guangdong Talents Project, the National Basic Research Program of China(2015CB856505)the National Natural Science Foundation of China(51373075)Guangdong Academician Workstation(2013B090400016)the Natural Science Foundation of Guangdong Province(2014A030313800)
文摘Thieno[3,2-b]thiophene(TT)monomers end-capped with 3,4-ethylenedioxythiophene(EDOT)moieties are electropolymerized to formπ-conjugated polymers with distinct electrochromic(EC)properties.Steric and electronic factors(electron donor and acceptor substituents)in the side groups of the TT core,as well as the structure of the polymer backbone strongly affect the electrochemical and optical properties of the polymers and their electrochromic characteristics.The studied polymers show low oxidation potentials,tunable from-0.78 to+0.30 V(vs.Fc/Fc^+)and the band gaps from 1.46 to 1.92 eV and demonstrate wide variety of color palettes in polymer films in different states,finely tunable by structural variations in the polymer backbone and the side chains.EC materials of different colors in their doped/dedoped states have been developed(violet,deep blue,light blue,green,brown,purple-red,pinkish-red,orange-red,light gray,cyan and colorless transparent).High optical contrast(up to 79%),short response time(0.57-0.80 s),good cycling stability(up to 91%at 2000 cycles)and high coloration efficiency(up to 234.6 cm2C^(-1))have been demonstrated and the influence of different factors on the above parameters of EC polymers have been discussed.
基金the National Natural Science Foundation of China(21274138,21273207,21474096)the Chinese Academy of Sciences(Integrated system of high efficiency building energy saving and its application,KFZD-SW-403)
文摘By converting incident light into electric power,self-powered electrochromic window(SP-ECW)can achieve color change in electrochromic layer with no need for external voltage.In this work,a newly-de signed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light.The device consists of a working electrode with planar integration of photovoltaic(PV)and electrochromic(EC)elements on one electrode,a platinum counter electrode and a redox electrolyte comprising Br^-/Br_3^-couple.A high transmittance modulation of 41%at 582 nm is obtained.Electrical energy converted from light is not only sufficient to drive the device,but also can be outputted to the external circuit.
