The study was carried out in the Tahoua region at the market gardening sites of the Taddis 1 and 2 valley. Small-scale pumping irrigation is one of the most interesting uses of solar energy. The objective of this stud...The study was carried out in the Tahoua region at the market gardening sites of the Taddis 1 and 2 valley. Small-scale pumping irrigation is one of the most interesting uses of solar energy. The objective of this study is to carry out a comparative analysis of two dewatering pumping systems (Solar Kit and GMP) for water mobilization on a certain number of criteria such as sustainable use, economic aspect and performance. To achieve this, the adapted methodology consisted first of all in the development of a data collection tool in the field. Then flow measurements, estimation of fuel consumption, pressure height, etc., were carried out. Thus, the data collection involved a sample of 120 irrigators who had to use the two (2) types of pumping systems. The collected data were analyzed and processed with appropriate software. The results of the study show that the two pumping systems studied have strengths and constraints. Thus, the solar pumping system has a significant investment cost, very low maintenance and a low operating cost. On the other hand, the system with a generator has a relatively low investment cost (25 to 30 times less than solar), but a relatively high operating, upkeep and maintenance cost. He adds that these assets and constraints must be taken into consideration when an investment is made. This study shows that 74% of producers use GMP compared to 26% who use the Solar Kit. But in practice, the Solar Kit is more reliable for producers from the point of view of planted area, environmental management and investment costs, supply of fuel and lubricant. These results indicate better performance of the solar pumping system compared to GMP at the study sites.展开更多
This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the a...This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the adoption process from becoming aware of solar pumping systems to testing them, i.e. using them at least once, and then continuing to use them over time. The results show that the main variables affecting awareness of the use of solar pumping systems (PV) are age, marital status, experience, access to credit, the farmer’s knowledge of climate change, the farmer’s origin in the Thiès region and length of time in the Niayes area. The first use of PVs is influenced by factors such as the size of the plot, the distance of the plot from the main road or from the market. Finally, the decision to adopt or continue use is influenced by gender, experience, household size and access to credit. Surprisingly, access to credit does not affect the first use of solar pumping systems, but plays a key role in their continued use.展开更多
Dynamometer cards are commonly used to analyze down-hole working conditions of pumping systems in actual oil production. Nowadays, the traditional supervised learning methods heavily rely on the classification accurac...Dynamometer cards are commonly used to analyze down-hole working conditions of pumping systems in actual oil production. Nowadays, the traditional supervised learning methods heavily rely on the classification accuracy of the training samples. In order to reduce the errors of manual classification, an automatic clustering algorithm is proposed and applied to diagnose down-hole conditions of pumping systems. The spectral clustering （SC） is a new clustering algorithm, which is suitable for any data distribution. However, it is sensitive to initial cluster centers and scale parameters, and needs to predefine the cluster number. In order to overcome these shortcom- ings, we propose an automatic clustering algorithm, fast black hole-spectral clustering （FBH-SC）. The FBH algo- rithm is used to replace the K-mean method in SC, and a CritC index function is used as the target function to automatically choose the best scale parameter and clus- tering number in the clustering process. Different simulation experiments were designed to define the relationship among scale parameter, clustering number, CritC index value, and clustering accuracy. Finally, an example is given to validate the effectiveness of the proposed algorithm.展开更多
The design of the pumping stations and the gas injection systems for the inner Chamber and the cryostat on HT-7U superconducting tokamak is described in this paper.
Given the steady increase in use of alternative energy sources to supply part of the energy demand of the world, and considering that Mexico has enough wind resources to produce all the electricity required by the cou...Given the steady increase in use of alternative energy sources to supply part of the energy demand of the world, and considering that Mexico has enough wind resources to produce all the electricity required by the country, in this work, it is carried out the development of a system of wind resource assessment to determine the volume of water that a windmill pumping system can provide in a specific area. To this end, it has developed a computer program for wind resource assessment by measurements of wind speed, direction, temperature, barometric pressure and relative humidity. Measuring equipments were mounted in a wind measurement tower of 10 m high, within the premises of the University of Quintana Roo which is located along the coast. Until this day, there are records over a period of five months of the variables of wind speed, wind direction, temperature, relative humidity and atmospheric pressure. These variables were used for statistical calculations using the Weibull distributions. To give a better use of the calculated data, they were applied to the evaluation of a Pumping System.展开更多
The demand for renewable energy technologies is increasing globally.With the rapid depletion of fossil fuels and the growing awareness of their harmful impacts on the environment and climate,there is an urgent need to...The demand for renewable energy technologies is increasing globally.With the rapid depletion of fossil fuels and the growing awareness of their harmful impacts on the environment and climate,there is an urgent need to focus on developing renewable resources.However,a significant challenge with renewable energy is its variability due to factors like weather and time of day.This causes the amount of generated power to vary drastically in unfavorable situations,making the design of effective storage technologies a high priority.The primary role of these structures is to store excess energy and release it later at peak shaving.Among various available storage methods,pumped hydro storage systems are prominent,particularly for bulk energy storage.Owing to the complexity of the site selection process for these structures,developing and arranging key site selection indicators based on precise location criteria is critical.In the present case study in Tehran Province,Iran,seven suitability indicators based on 24 location criteria were defined to optimize the site selection process for hydro-pumped storage systems.Each index includes a specific number of site selection sub-criteria.To prioritize the criteria,the Fuzzy Analytic Hierarchy Process method and surveys from five experts were applied to determine the final weights.Using this method,several suitable locations with different varieties were identified throughout the Tehran Province,Iran.展开更多
A new hydrogen storage alloy pair, La0.6Ml0.4Ni4.7 Cr0.3-La0.2Mm0.8Ni4.35Fe0.65, was developed to serve as a bus hydride air conditioner, which utilizes the waste heat of exhaust gases of a bus as the high temperature...A new hydrogen storage alloy pair, La0.6Ml0.4Ni4.7 Cr0.3-La0.2Mm0.8Ni4.35Fe0.65, was developed to serve as a bus hydride air conditioner, which utilizes the waste heat of exhaust gases of a bus as the high temperature source. Under the operating temperature of 150-250 °C/35-40°C/15-20°C, the maximum working hydrogen capacity and the theoretical value of COPc are 4.5 and 0.74 H/mol M respectively, which can meet the practical requirements.展开更多
In this paper, aiming at practical dense wavelength division multiplexing （DWDM） system with ultralong fiber span, a simple co-fiber remotely pumped erbium-doped fiber amplifier （RP-EDFA） scheme is proposed to ext...In this paper, aiming at practical dense wavelength division multiplexing （DWDM） system with ultralong fiber span, a simple co-fiber remotely pumped erbium-doped fiber amplifier （RP-EDFA） scheme is proposed to extend span distance with simple configuration and low pump power. Equivalent noise figure of -6 dB is achieved under 300-mW pump power. Using the experiment results, numerical simulation of ultra-long span systems shows that for a 40 × 11.6-Gb/s transmission system, the RP-EDFA scheme can support transmission of 1760 km with a fiber span of 160 km. These results demonstrate the potential of the PR-EDFA scheme in ultra-long span transmission.展开更多
文摘The study was carried out in the Tahoua region at the market gardening sites of the Taddis 1 and 2 valley. Small-scale pumping irrigation is one of the most interesting uses of solar energy. The objective of this study is to carry out a comparative analysis of two dewatering pumping systems (Solar Kit and GMP) for water mobilization on a certain number of criteria such as sustainable use, economic aspect and performance. To achieve this, the adapted methodology consisted first of all in the development of a data collection tool in the field. Then flow measurements, estimation of fuel consumption, pressure height, etc., were carried out. Thus, the data collection involved a sample of 120 irrigators who had to use the two (2) types of pumping systems. The collected data were analyzed and processed with appropriate software. The results of the study show that the two pumping systems studied have strengths and constraints. Thus, the solar pumping system has a significant investment cost, very low maintenance and a low operating cost. On the other hand, the system with a generator has a relatively low investment cost (25 to 30 times less than solar), but a relatively high operating, upkeep and maintenance cost. He adds that these assets and constraints must be taken into consideration when an investment is made. This study shows that 74% of producers use GMP compared to 26% who use the Solar Kit. But in practice, the Solar Kit is more reliable for producers from the point of view of planted area, environmental management and investment costs, supply of fuel and lubricant. These results indicate better performance of the solar pumping system compared to GMP at the study sites.
文摘This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the adoption process from becoming aware of solar pumping systems to testing them, i.e. using them at least once, and then continuing to use them over time. The results show that the main variables affecting awareness of the use of solar pumping systems (PV) are age, marital status, experience, access to credit, the farmer’s knowledge of climate change, the farmer’s origin in the Thiès region and length of time in the Niayes area. The first use of PVs is influenced by factors such as the size of the plot, the distance of the plot from the main road or from the market. Finally, the decision to adopt or continue use is influenced by gender, experience, household size and access to credit. Surprisingly, access to credit does not affect the first use of solar pumping systems, but plays a key role in their continued use.
基金the National Natural Science Foundation of China (Grant No. 61403040)
文摘Dynamometer cards are commonly used to analyze down-hole working conditions of pumping systems in actual oil production. Nowadays, the traditional supervised learning methods heavily rely on the classification accuracy of the training samples. In order to reduce the errors of manual classification, an automatic clustering algorithm is proposed and applied to diagnose down-hole conditions of pumping systems. The spectral clustering （SC） is a new clustering algorithm, which is suitable for any data distribution. However, it is sensitive to initial cluster centers and scale parameters, and needs to predefine the cluster number. In order to overcome these shortcom- ings, we propose an automatic clustering algorithm, fast black hole-spectral clustering （FBH-SC）. The FBH algo- rithm is used to replace the K-mean method in SC, and a CritC index function is used as the target function to automatically choose the best scale parameter and clus- tering number in the clustering process. Different simulation experiments were designed to define the relationship among scale parameter, clustering number, CritC index value, and clustering accuracy. Finally, an example is given to validate the effectiveness of the proposed algorithm.
文摘The design of the pumping stations and the gas injection systems for the inner Chamber and the cryostat on HT-7U superconducting tokamak is described in this paper.
文摘Given the steady increase in use of alternative energy sources to supply part of the energy demand of the world, and considering that Mexico has enough wind resources to produce all the electricity required by the country, in this work, it is carried out the development of a system of wind resource assessment to determine the volume of water that a windmill pumping system can provide in a specific area. To this end, it has developed a computer program for wind resource assessment by measurements of wind speed, direction, temperature, barometric pressure and relative humidity. Measuring equipments were mounted in a wind measurement tower of 10 m high, within the premises of the University of Quintana Roo which is located along the coast. Until this day, there are records over a period of five months of the variables of wind speed, wind direction, temperature, relative humidity and atmospheric pressure. These variables were used for statistical calculations using the Weibull distributions. To give a better use of the calculated data, they were applied to the evaluation of a Pumping System.
文摘The demand for renewable energy technologies is increasing globally.With the rapid depletion of fossil fuels and the growing awareness of their harmful impacts on the environment and climate,there is an urgent need to focus on developing renewable resources.However,a significant challenge with renewable energy is its variability due to factors like weather and time of day.This causes the amount of generated power to vary drastically in unfavorable situations,making the design of effective storage technologies a high priority.The primary role of these structures is to store excess energy and release it later at peak shaving.Among various available storage methods,pumped hydro storage systems are prominent,particularly for bulk energy storage.Owing to the complexity of the site selection process for these structures,developing and arranging key site selection indicators based on precise location criteria is critical.In the present case study in Tehran Province,Iran,seven suitability indicators based on 24 location criteria were defined to optimize the site selection process for hydro-pumped storage systems.Each index includes a specific number of site selection sub-criteria.To prioritize the criteria,the Fuzzy Analytic Hierarchy Process method and surveys from five experts were applied to determine the final weights.Using this method,several suitable locations with different varieties were identified throughout the Tehran Province,Iran.
文摘A new hydrogen storage alloy pair, La0.6Ml0.4Ni4.7 Cr0.3-La0.2Mm0.8Ni4.35Fe0.65, was developed to serve as a bus hydride air conditioner, which utilizes the waste heat of exhaust gases of a bus as the high temperature source. Under the operating temperature of 150-250 °C/35-40°C/15-20°C, the maximum working hydrogen capacity and the theoretical value of COPc are 4.5 and 0.74 H/mol M respectively, which can meet the practical requirements.
文摘In this paper, aiming at practical dense wavelength division multiplexing （DWDM） system with ultralong fiber span, a simple co-fiber remotely pumped erbium-doped fiber amplifier （RP-EDFA） scheme is proposed to extend span distance with simple configuration and low pump power. Equivalent noise figure of -6 dB is achieved under 300-mW pump power. Using the experiment results, numerical simulation of ultra-long span systems shows that for a 40 × 11.6-Gb/s transmission system, the RP-EDFA scheme can support transmission of 1760 km with a fiber span of 160 km. These results demonstrate the potential of the PR-EDFA scheme in ultra-long span transmission.
