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Meta-analysis of CO_(2) conversion,energy efficiency,and other performance data of plasma-catalysis reactors with the open access PIONEER database
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作者 Antoine Salden Maik Budde +28 位作者 Carolina A.Garcia-Soto Omar Biondo Jairo Barauna Marzia Faedda Beatrice Musig ChloéFromentin Minh Nguyen-Quang Harry Philpott Golshid Hasrack Domenico Aceto Yuxiang Cai Federico Azzolina Jury Annemie Bogaerts Patrick Da Costa Richard Engeln María Elena Gálvez Timo Gans Tomas Garcia Vasco Guerra Carlos Henriques Monika Motak Maria Victoria Navarro Vasile I.Parvulescu Gerard Van Rooij Bogdan Samojeden Ana Sobota Paolo Tosi Xin Tu Olivier Guaitella 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期318-342,I0007,共26页
This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This t... This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been developed and is available online to the public.The simple and fast visualisation of the state of the art puts new results into context,identifies literal gaps in data,and consequently points towards promising research routes.More advanced data extraction illustrates the impact that the database can have in the understanding of plasma-catalyst coupling.Lessons learned from the review of a large amount of literature during the setup of the database lead to best practice advice to increase comparability between future CO_(2)plasma-catalytic studies.Finally,the community is strongly encouraged to contribute to the database not only to increase the visibility of their data but also the relevance of the comparisons allowed by this tool. 展开更多
关键词 Open-access database on plasma-catalysis experiment CO_(2) conversion PLASMA-CATALYSIS Carbon capture and utilisation(CCU) Energy efficiency Specific energy input Dielectric barrier discharge Packed bed reactor METHANATION Dry reforming of methane
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Performance Assessment of a Real PV System Connected to a Low-Voltage Grid
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作者 Gaber Magdy Mostafa Metwally +1 位作者 Adel A.Elbaset Esam Zaki 《Energy Engineering》 EI 2024年第1期13-26,共14页
The generation of photovoltaic(PV)solar energy is increasing continuously because it is renewable,unlimited,and clean energy.In the past,generation systems depended on non-renewable sources such as oil,coal,and gas.Th... The generation of photovoltaic(PV)solar energy is increasing continuously because it is renewable,unlimited,and clean energy.In the past,generation systems depended on non-renewable sources such as oil,coal,and gas.Therefore,this paper assesses the performance of a 51 kW PV solar power plant connected to a low-voltage grid to feed an administrative building in the 6th of October City,Egypt.The performance analysis of the considered grid-connected PV system is carried out using power system simulator for Engineering(PSS/E)software.Where the PSS/E program,monitors and uses the power analyzer that displays the parameters and measures some parameters such as current,voltage,total power,power factor,frequency,and current and voltage harmonics,the used inverter from the type of grid inverter for the considered system.The results conclude that when the maximum solar radiation is reached,the maximum current can be obtained from the solar panels,thus obtaining the maximum power and power factor.Decreasing total voltage harmonic distortion,a current harmonic distortion within permissible limits using active harmonic distortion because this type is fast in processing up to 300 microseconds.The connection between solar stations and the national grid makes the system more efficient. 展开更多
关键词 Low-voltage grid photovoltaic(PV)system total harmonic distortion grid-connected PV system
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Proper Understanding of the Nerve Impulses and the Action Potential
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作者 Salama Abdelhady 《World Journal of Neuroscience》 2023年第3期103-117,共15页
Neurologists define the transmission of nerve impulses across the membranes of the neural cells as a result of difference in the concentration of ions while they measured an electric potential, called as an action pot... Neurologists define the transmission of nerve impulses across the membranes of the neural cells as a result of difference in the concentration of ions while they measured an electric potential, called as an action potential, which allows the propagation of such nerve impulses as electrical signals. Such measurements should guide them to a logical explanation of the nerve impulses as electric charges driven by the measured action potential. However, such logical conclusion, or explanation, is ignored due to a wrong definition of the flow of electric charges as a flow of electrons that cannot pass through neural networks. According to recent studies, electric charges are properly defined as electromagnetic (EM) waves whose energy is expressed as the product of its propagating electric potential times their entropy flow which is adhered to the flow of such energy. Such definition matches the logical conclusion of the nerve impulses as electric charges, as previously explained, and defines the entropy of the neural network, measured by Ammeters, in Watt or Joule/Volt. The measured entropy represents a neurodiagnostic property of the neural networks that measures its capacity to allow the flow of energy per unit action potential. Theoretical verification of the innovative definition of nerve impulses is presented by following an advanced entropy approach. A proper review of the machine records of the stimulating electric charges, used in the diagnosis of the neural networks, and the stimulated nerve impulses or stimulated responses, represents practical verifications of the innovative definitions of the electric charges and the nerve impulses. Comparing the functioning of the thermoelectric generators and the brain neurons, such neurons are defined as thermoelectric generators of the electric nerve impulses and their propagating, or action, potential. 展开更多
关键词 Nerve Impulses Action Potential Electric Charges ENTROPY Electromagnetic Waves Thermoelectric Generators
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Proper Understanding of the Natures of Electrons, Protons, and Modifying Redundancies in Electro-Magnetism
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作者 Salama Abdelhady 《Journal of Electromagnetic Analysis and Applications》 2023年第5期59-72,共14页
When considering electromagnetism, the unit of the Ammeter’s measurement should be limited to its proper unit in “Watt/Volt” which is, according to physical principles, the division quotient of the measured electri... When considering electromagnetism, the unit of the Ammeter’s measurement should be limited to its proper unit in “Watt/Volt” which is, according to physical principles, the division quotient of the measured electrical power by its electrical potential. However, the Ammeter’s reading has also a traditional definition as the rate of flow of electric charges whose unit is “Ampere”. According to recent studies that define the electric charge as energy possessing an electric potential, such traditional definition is wrong as the Ammeter’s reading should, then, has the unit “Watt”. Such duality of the Ammeter’s reading is due to the wrong definition of electric charges as electrons and insertion of the “Ampere”, as a wrong unit of the flow of electric charges. This duality represents a “redundancy” in electromagnetism as the proper Ammeter’s reading, in Watt/Volt, is a unit of entropy of the flowing energy charges. Such redundancy led to further redundancies in the field of electromagnetism. In this article, it is followed the impacts of inserting the “Ampere” as illogic unit and it is derived the proper modifications of the results of replacing the “Ampere” by its logical substitute “Watt/Volt”. Such modifications lead to a robust definition of the electron as an elementary particle which has an elementary charge of energy 1.602 × 10<sup>-19</sup> Joules and has a negative electric potential of 1 Volt and to a proper definition of the protons as elementary particles which are charged by a similar charge of electron, but it has a positive potential of 1 Volt. Additionally, the electron-volt is properly defined as an elementary charge whose energy is 1.602 × 10<sup>-19</sup> Joules and whose potential is ±1 Volt. Such modifications also lead to improve the understanding of magnetic induction and modifying the equations that characterize the performance of electric machines. The truth of such innovative understandings is verified analytically and experimentally in this article. 展开更多
关键词 Electric Charge Magnetic Flux Electromagnetic Waves Entropy Field-Conductivities Magnetic Induction
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A novel correlation approach for prediction of natural gas compressibility factor 被引量:14
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作者 Ehsan Heidaryan Amir Salarabadi Jamshid Moghadasi 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2010年第2期189-192,共4页
Gas compressibility factor (z-Factor) is one of the most important parameters in upstream and downstream calculations of petroleum industries.The importance of z-Factor cannot be overemphasized in oil and gas engine... Gas compressibility factor (z-Factor) is one of the most important parameters in upstream and downstream calculations of petroleum industries.The importance of z-Factor cannot be overemphasized in oil and gas engineering calculations.The experimental measurements,Equations of State (EoS) and empirical correlations are the most common sources of z-Factor calculations.There are more than twenty correlations available with two variables for calculating the z-Factor from fitting in an EoS or just through fitting techniques.However,these correlations are too complex,which require initial value and more complicated and longer computations or have magnitude error.The purpose of this study is to develop a new accurate correlation to rapidly estimate z-Factor.Result of this correlation is compared with large scale of database and experimental data also.Proposed correlation has 1.660 of Absolute Percent Relative Error (EABS) versus Standing and Katz chart and has also 3.221 of EABS versus experimental data.The output of this correlation can be directly assumed or be used as an initial value of other implicit correlations.This correlation is valid for gas coefficient of isothermal compressibility (cg) calculations also. 展开更多
关键词 natural gas compressibility factor Standing and Katz chart CORRELATION
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Effect of roadway turnings on gas explosion propagation characteristics in coal mines 被引量:12
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作者 Zhu Chuanjie Lin Baiquan +1 位作者 Ye Qing Zhai Cheng 《Mining Science and Technology》 EI CAS 2011年第3期365-369,共5页
In order to reveal the effect of turnings on explosion propagation, experiments were performed in three different pipes (single bend, U-shaped pipe and Z-shaped pipe). Flame and pressure transducers were used to track... In order to reveal the effect of turnings on explosion propagation, experiments were performed in three different pipes (single bend, U-shaped pipe and Z-shaped pipe). Flame and pressure transducers were used to track the velocity at the explosion front. When the pipes were filled with methane, the explosion strength was significantly enhanced due to the turbulence induced by increasing the number of turnings, while the flame speed (S f) and peak overpressure (DP max) increased dramatically. In addition, the strength of the explosion increased in violence as a function of the number of turnings. However, when the bend was without methane, the turnings weakened the strength of the explosion compared with the ordinary pipe, shown by the decrease in the values of DP max and S f . In addition, the propagation characteristics in a U-shaped pipe were similar to those in a Z-shaped pipe and the values of DP max and S f were also close. The results show that the explosion propagation characteristics largely depend on gas distribution in the pipes and the number of turnings. The different directions of the turnings had no effect. 展开更多
关键词 煤矿瓦斯爆炸 传播特性 转弯 火焰传播速度 天然气管道 巷道 爆炸强度 压力传感器
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Development of solid-state electrolytes for sodium-ion battery–A short review 被引量:8
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作者 Yumei Wang Shufeng Song +3 位作者 Chaohe Xu Ning Hu Janina Molenda Li Lu 《Nano Materials Science》 CAS 2019年第2期91-100,共10页
All-solid-state sodium-ion battery is regarded as the next generation battery to replace the current commercial lithium-ion battery, with the advantages of abundant sodium resources, low price and high-level safety. A... All-solid-state sodium-ion battery is regarded as the next generation battery to replace the current commercial lithium-ion battery, with the advantages of abundant sodium resources, low price and high-level safety. As one critical component in sodium-ion battery, solid-state electrolyte should possess superior operational safety and design simplicity, yet reasonable high room-temperature ionic conductivity. This paper gives a comprehensive review on the recent progress in solid-state electrolyte materials for sodium-ion battery, including inorganic ceramic/glass-ceramic, organic polymer and ceramic-polymer composite electrolytes, and also provides a comparison of the ionic conductivity in various solid-state electrolyte materials. The development of solid-state electrolytes suggests a bright future direction: all solid-state sodium-ion battery could be fully used to power all electric road vehicles, portable electronic devices and large-scale grid support. 展开更多
关键词 Sodium ion battery IONIC CONDUCTIVITY INORGANIC SOLID ELECTROLYTE SOLID polymer ELECTROLYTE Ceramic-polymer composite ELECTROLYTE
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A review on the critical challenges and progress of SiO_(x)-based anodes for lithium-ion batteries 被引量:4
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作者 Nana Yao Yu Zhang +4 位作者 Xianhui Rao Zhao Yang Kun Zheng KonradŚwierczek Hailei Zhao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第4期876-895,共20页
With the advantages of abundant resources,high specific capacity,and relatively stable cycling performance,silicon suboxides(SiO_(x) ,x<2)have been recently suggested as promising anodes for next-generation lithium... With the advantages of abundant resources,high specific capacity,and relatively stable cycling performance,silicon suboxides(SiO_(x) ,x<2)have been recently suggested as promising anodes for next-generation lithium-ion batteries(LIBs).SiO_(x) exhibits superior storage capability because of the presence of silicon and smaller volume change upon charge/discharge than Si owing to the buffering effect of the initial lithiation products of inert lithium oxide and lithium silicates,enabling a stable cycle life of electrodes.However,significant improvements such as overcoming issues related to volume changes in cycling and initial irreversible capacity loss and enhancing the ionic and electronic charge transport in poorly conducting SiO_(x) electrodes,are still needed to achieve the satisfactory performance required for commercial applications.This review summarizes recent progress on the cycling performance and initial coulombic efficiency of SiO_(x) .Advances in the design of particle morphology and composite composition,prelithiation and prereduction methods,and usage of electrolyte additives and optimized electrode binders are discussed.Perspectives on the promising research directions that might lead to further improvement of the electrochemical properties of SiO_(x) -based anodes are noted.This paper can serve as a basis for the research and development of high-energy-density LIBs. 展开更多
关键词 silicon suboxides preparation structural optimization ANODE lithium-ion batteries
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Mass transfer investigation and operational sensitivity analysis of aminebased industrial CO_2 capture plant 被引量:1
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作者 Abbas Hemmati Hamed Rashidi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第3期534-543,共10页
In this article, the industrial process of CO_2 capture using monoethanolamine as an aqueous solvent was probed carefully from the mass transfer viewpoint. The simulation of this process was done using Rate-Base model... In this article, the industrial process of CO_2 capture using monoethanolamine as an aqueous solvent was probed carefully from the mass transfer viewpoint. The simulation of this process was done using Rate-Base model, based on two-film theory. The results were validated against real plant data. Compared to the operational unit, the error of calculating absorption percentage and CO_2 loading was estimated around 2%. The liquid temperature profiles calculated by the model agree well with the real temperature along the absorption tower, emphasizing the accuracy of this model. Operational sensitivity analysis of absorption tower was also done with the aim of determining sensitive parameters for the optimized design of absorption tower and optimized operational conditions. Hence,the sensitivity analysis was done for the flow rate of gas, the flow rate of solvent, flue gas temperature, inlet solvent temperature, CO_2 concentration in the flue gas, loading of inlet solvent, and MEA concentration in the solvent. CO_2 absorption percentage, the profile of loading, liquid temperature profile and finally profile of CO_2 mole fraction in gas phase along the absorption tower were studied. To elaborate mass transfer phenomena, enhancement factor, interfacial area, molar flux and liquid hold up were probed. The results show that regarding the CO_2 absorption, the most important parameter was the gas flow rate. Comparing liquid temperature profiles showed that the most important parameter affecting the temperature of the rich solvent was MEA concentration. 展开更多
关键词 Carbon dioxide MONOETHANOLAMINE Rate-base model ENHANCEMENT FACTOR Sensitivity analysis
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Operando FT-IR study on basicity improvement of Ni(Mg,AI)O hydrotalcitederived catalysts promoted by glow plasma discharge 被引量:1
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作者 R DEBEK D WIERZBICKI +3 位作者 M MOTAK M E GALVEZ P DA COSTA F AZZOLINA-JURY 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第4期123-136,共14页
CO2 adsorption on the surface of hydrotalcite-derived mixed oxide catalysts was investigated under low pressure glow discharge plasma in opercindo conditions via FT-IR spectroscopy.Nickel catalysts were promoted with ... CO2 adsorption on the surface of hydrotalcite-derived mixed oxide catalysts was investigated under low pressure glow discharge plasma in opercindo conditions via FT-IR spectroscopy.Nickel catalysts were promoted with various transition metal species(Ce,Fe,La,Zr)to influence their physico-chemical properties.Fe and Zr species were successfully incorporated into hydrotalcite brucite layers.After calcination formed a single phase with Ni(Mg,A1)O mixed oxide,while La and Ce species formed separate phases.This had a consequence in the distribution of surface basic sites as well as in the affinity to CO produced upon CO2 dissociation in plasma.Plasma treatment activated the surface of prepared materials and changed their properties via the generation of strong basic sites associated with low coordinated surface oxygen anions.Moreover,the CO2 adsorption capacity of prepared materials increased after plasma treatment. 展开更多
关键词 plasma GLOW DISCHARGE BASICITY HYDROTALCITE carbon dioxide
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Study of Micro Grid Safety &Protection Strategies with Control System Infrastructures 被引量:2
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作者 Md Razibul Islam Hossam A. Gabbar 《Smart Grid and Renewable Energy》 2012年第1期1-9,共9页
Microgrids have been proposed in order to improve reliability and stability of electrical system and to ensure power quality of grid. Microgrid consists of low voltage distribution systems with distributed energy reso... Microgrids have been proposed in order to improve reliability and stability of electrical system and to ensure power quality of grid. Microgrid consists of low voltage distribution systems with distributed energy resources, such as wind turbine and photovoltaic power systems, together with storage devices. It is essential to protect a micro grid in both the grid-connected and the islanded mode of operation against all different types of faults. This paper describes micro grid protection and safety concept with central control and monitoring unit where multifunctional intelligent digital relay could be used. This central control & monitoring infrastructure is used for adaptive relay settings strategy for micro grid protection. Also operational safety design concept and fault mitigation technique is proposed to ensure confidence in protection system. 展开更多
关键词 MICRO GRID (MG) Distributed GENERATOR (DG) MICRO GRID CENTRAL Control (MCC)
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Experimental and Numerical Study of Dilute Gas-Solid Flow inside a 90°Horizontal Square Pipe Bend 被引量:1
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作者 Walid Aniss Aissa Tarek Abdel Malak Mekhail +1 位作者 Soubhi Ali Hassanein Osama Hamdy 《Open Journal of Fluid Dynamics》 2013年第4期331-339,共9页
A pneumatic test rig is built to test a curved 90° square bend in an open-circuit horizontal-to-horizontal suction wind tunnel system. Sand particles are used to represent the solid phase with a wide range of par... A pneumatic test rig is built to test a curved 90° square bend in an open-circuit horizontal-to-horizontal suction wind tunnel system. Sand particles are used to represent the solid phase with a wide range of particle diameters. Velocity profiles are constructed by measuring the gas velocity using a 3-hole probe. Flow patterns inside the bend duct are introduced using sparks caused by burning sticks of incense with the air flow inside the piping system for flow visualization purpose. Numerical calculations are performed by Lagrangian-particle tracking model for predicting particle trajectories of dispersed phase, and standard k-ε model for predicting the turbulent gas-solid flows in bends. Comparisons made between the theoretical results and experimental data for the velocity vectors and particle trajectories show good agreement. 展开更多
关键词 90° BEND CFD GAS-SOLID Flow k - ε Model
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PI-MPC Frequency Control of Power System in the Presence of DFIG Wind Turbines 被引量:1
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作者 Michael Z. Bernard T. H. Mohamed +2 位作者 Raheel Ali Yasunori Mitani Yaser Soliman Qudaih 《Engineering(科研)》 2013年第9期43-50,共8页
For the recent expansion of renewable energy applications, Wind Energy System (WES) is receiving much interest all over the world. However, area load change and abnormal conditions lead to mismatches in frequency and ... For the recent expansion of renewable energy applications, Wind Energy System (WES) is receiving much interest all over the world. However, area load change and abnormal conditions lead to mismatches in frequency and scheduled power interchanges between areas. These mismatches have to be corrected by the LFC system. This paper, therefore, proposes a new robust frequency control technique involving the combination of conventional Proportional-Integral (PI) and Model Predictive Control (MPC) controllers in the presence of wind turbines (WT). The PI-MPC technique has been designed such that the effect of the uncertainty due to governor and turbine parameters variation and load disturbance is reduced. A frequency response dynamic model of a single-area power system with an aggregated generator unit is introduced, and physical constraints of the governors and turbines are considered. The proposed technique is tested on the single-area power system, for enhancement of the network frequency quality. The validity of the proposed method is evaluated by computer simulation analyses using Matlab Simulink. The results show that, with the proposed PI-MPC combination technique, the overall closed loop system performance demonstrated robustness regardless of the presence of uncertainties due to variations of the parameters of governors and turbines, and loads disturbances. A performance comparison between the proposed control scheme, the classical PI control scheme and the MPC is carried out confirming the superiority of the proposed technique in presence of doubly fed induction generator (DFIG) WT. 展开更多
关键词 DOUBLY Fed Induction Generator Power SYSTEM Model PREDICTIVE Control) Proportional Integral Controller DFIG WIND TURBINE WIND Energy SYSTEM (WES)
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Performance Investigation of the Solar Chimney Power Plants Heater Case Study in Aswan, Egypt 被引量:1
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作者 Magdy Bassily Hanna Tarek Abdel-Malak Mekhail +2 位作者 Omar Mohamed Dahab Mohamed Fathy Cidek Esmail Ahmed Rekaby Abdel-Rahman 《Journal of Power and Energy Engineering》 2016年第10期39-60,共23页
Solar collector is a thermal device that uses the heated air in the power generation and many engineering applications. The purpose of the present work is to study the performance and temperature distribution for the ... Solar collector is a thermal device that uses the heated air in the power generation and many engineering applications. The purpose of the present work is to study the performance and temperature distribution for the solar collector which uses heated air in solar chimney power generation that it consist of three parts, a turbine-generator unit which is used in the generation of electric energy, and cylindrical chimney is fixed vertically and finally a solar collector under the climatic conditions of Egypt-Aswan is studied. This site is specified as the hottest site because the nearest of this location from the Tropic of cancer. Experiments are performed in ten summer days of May and June 2015 with different solar radiations and clarity of the sky. Hourly values of global solar radiation and some meteorological data (temperature, pressure, velocity, etc.) for measuring days are obtained by measuring devices. Inlet and outlet temperatures of air from a solar collector and velocity at junction region. In this work, attempt has been made to present the effect of environmental factors such as ambient temperature, the clarity of the sky and solar radiation on the performance of solar collector. The temperature of the base and the cover of the solar collector, the variation of solar radiation, solar collector efficiency, heat transfer coefficient, the velocity at the junction region between the chimney base, the outlet of the solar collector and temperature distribution along the air heater are discussed. A prediction for the results of the solar collector were performed by using developed theoretical model was made by this study which is based on the previous works. The numerical study has used a commercial code CFX, ANSYS 16.1 to simulate the flow through the collector. The study show that the outlet air temperatures from the solar collector and the velocity at the junction are depending on the climate condition such as ambient temperature and solar radiation, the differences in air temperature at the solar collector ranging between 8° - 24°. It is concluded that the theoretical model is basically valid for the system under study, and theCFD simulation can be used conveniently to predict the performance of the system, the comparison between them and experimental result shows a good agreement. 展开更多
关键词 Solar Chimney Solar Collector Natural Convection Computational Fluid Dynamic
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Experimental Study of Filling Ratio Effect on the Thermal Performance in a Multi-Heat Pipe with Graphene Oxide/Water Nanofluids 被引量:2
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作者 Mohamed Salem Tarek A. Meakhail +1 位作者 Magdy A. Bassily Shuichi Torii 《World Journal of Nano Science and Engineering》 2016年第4期153-164,共12页
This experimental study is performed to investigate heat transfer performance of a multi-heat pipe cooling device in the condition of different filling ratios (40%, 60%, 80% and 100%) and different constant heat fluxe... This experimental study is performed to investigate heat transfer performance of a multi-heat pipe cooling device in the condition of different filling ratios (40%, 60%, 80% and 100%) and different constant heat fluxes (10 - 30 W). Here, pure water (distilled water) and graphene oxide (GO)/water nanofluids are employed respectively as working fluid. GO/water nanofluids were synthesized by the modified Hummers method with 0.05%, 0.10%, 0.15%, and 0.20% volume concentrations. Multi-heat pipe is fabricated from copper;the heating and cooling sections are the same size and both are connected by four circular parallel tubes. Temperature fields and thermal resistance are measured for different filling ratio, heat fluxes and volume concentrations. The results indicated that the thermal performance of heat pipe increased with increasing the concentration of GO nanoparticles in the base fluid, while the maximum heat transfer enhancement was observed at 0.20% volume concentration. GO/water nanofluids showed lower thermal resistance compared to pure water;the optimal thermal resistance was obtained at 100% filling charge ratio with 0.20% volume concentration. Studies were also demonstrated that heat transfer coefficient of the heat pipe significantly increases with increasing the input heat flux and GO nanoparticles concentration. 展开更多
关键词 Multi-Heat Pipe Graphene Oxide Filling Ratio Volume Fraction Thermal Resistance
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Sensitivity of the area method with mono isotopic fission chambers to reactivity changes in subcritical nuclear reactors
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作者 Jerzy A.Janczyszyn Grazyna Domanska Przemysław Stanisz 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2021年第10期166-176,共11页
High-level waste is an important safety issue in the development of nuclear power.A proposed solution is the transmutation of waste in fast reactors.The exclusion of the risk of supercriticality by using subcritical r... High-level waste is an important safety issue in the development of nuclear power.A proposed solution is the transmutation of waste in fast reactors.The exclusion of the risk of supercriticality by using subcritical reactors is currently under development.Controlling the subcriticality level in such reactors presents difficulties.A problem is posed by the so-called space effect observed when using in reactors many neutron detectors in different locations of the core and reflector.Reactivity obtained from measure-ments,for example,by the Sjo¨strand method,differs by nonnegligible values.Numerical corrections can partially improve this situation.The use of a monoisotopic fission chamber set,designed for a given reactor,when each chamber is intended for a specific position in the system,can improve the situation.A question arises about the sensitivity of the results to reactivity changes.This issue is analyzed by computer simulation for possible fissionable and fissile nuclides for the total range of control rod insertion,changes in reactor fuel enrichment,and fuel temperature.The tested sensitivity was satisfactory at most levels from several dozen to several hundred pcm.A case study was conducted using the VENUS-F core model. 展开更多
关键词 SUBCRITICALITY Simulation Sjostrand method Fission chambers Space effect
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Experimental and Numerical Investigation of the Solar Chimney Power Plant’s Turbine 被引量:1
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作者 Magdy Bassily Hanna Tarek Abdel-Malak Mekhail +2 位作者 Omar Mohamed Dahab Mohamed Fathy Cidek Esmail Ahmed Rekaby Abdel-Rahman 《Open Journal of Fluid Dynamics》 2016年第4期332-342,共12页
The solar chimney power plant is a relatively new electricity generation concept, based on renewable energy, combining the greenhouse effect with the chimney suction. The solar chimney powerplant consists of three par... The solar chimney power plant is a relatively new electricity generation concept, based on renewable energy, combining the greenhouse effect with the chimney suction. The solar chimney powerplant consists of three parts, the solar collector, the chimney and the turbine generator unit, of which the study was focused on the later part. To evaluate the turbine performance inside the solar chimney powerplant, experimental system was constructed in Aswan, Egypt that has a metrological site (23°58'N and 32°47'E) occurs. The system was constructed to evaluate the performance of the solar chimney turbine and power generation characteristic in the hottest site where Aswan is located at the nearest of the Tropic of Cancer at the summer season. Velocity, electric power generation and the turbine efficiency are studying in this work. The numerical analyses were performed by using a commercial code CFX, ANSYS 16.1 to simulate the flow through the turbine and overall system. The study shows that the range of power generated (1.2 W - 4.4 W). It can be estimated, according to the results, the variation trend in pressure drops with the turbine rotation speed increase with small differences when the turbine rotation speed surpasses 1800 rpm with average efficiency of 57%. It is concluded that the theoretical model is basically valid for the system under study, and the CFD simulation can be used conveniently to predict the performance of the system, the comparison between them and experimental result shows a good agreement. 展开更多
关键词 Solar Chimney Natural Convection Turbine Modeling CFD
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Tiny pollutant emissions of a dimethyl ether fuelled engine
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作者 郎静 张煜盛 《Journal of Chongqing University》 CAS 2008年第4期284-290,共7页
Emissions of dimethyl ether(DME) fuelled engines were investigated by orthogonal experiments on a ZS195 diesel engine.The study mainly focused on the tiny pollutant emissions of formaldehyde(CH2O),methyl formate(CH3OC... Emissions of dimethyl ether(DME) fuelled engines were investigated by orthogonal experiments on a ZS195 diesel engine.The study mainly focused on the tiny pollutant emissions of formaldehyde(CH2O),methyl formate(CH3OCHO) and formic acid(HCOOH).The presence of CH2O,CH3OCHO and HCOOH are proved in the exhaust by gas chromatograph and Fourier transform infrared spectroscopy.The analysis of variance results indicate that the fuel delivery advance angle is the most important factor for CH2O emission.The fuel delivery advance angle and the interaction of injection pressure and nozzle diameter are considerable factors for unburned hydrocarbon(UHC) emission.The mechanism forming tiny pollutants,primarily through CH2O formation,is suggested to be similar to the mechanism forming UHC by DME partial oxidation existing in crevices and boundary zones,and is verified via DME combustion simulation of a multizone chemical kinetic model. 展开更多
关键词 二甲基醚 甲醛 发散 蚁酸 污染
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Molecular approach to determine taxonomic status of Septoria sp.causing leaf blotch of Castanea sativa in Hyrcanian forests
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作者 Hamed Yousefzadeh Abbas Saidi +2 位作者 Somayeh Tayebi Davoud Kartoolinejad Reza Naghdi 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第4期661-670,共10页
Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation me... Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680?bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples. 展开更多
关键词 Septoria castaneicola Hyrcanian forests ITS secondary structure Forest pathogen Plylogeny of fungi Sweet chestnut FAGACEAE
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Mathematical Model for the Injector of a Common Rail Fuel-Injection System 被引量:1
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作者 Simon Marcic1] Milan Marcic Zdravko Praunseis 《Engineering(科研)》 2015年第6期307-321,共15页
The paper describes a Diesel fuel injection process. Computer simulation was carried out together with measurement of the Common Rail accumulator fuel-injection system. The computer simulation enables the observation ... The paper describes a Diesel fuel injection process. Computer simulation was carried out together with measurement of the Common Rail accumulator fuel-injection system. The computer simulation enables the observation of the phenomena from rail pressure, being the input data for injection parameters calculations, to the injection rate. By means of computer simulation, the pressure values in specific sections of the injection nozzle may be computed, the needle lift, injection rate, total injected fuel, time lag from injector current to first evidence of injection process and other time-lags between various phases of the injection process. The injection rate provides input data for spray computer simulation. Measurements of injection and combustion were carried out within a transparent research engine. This engine is a single-cylinder transparent engine based on the AUDI V6 engine, equipped with a Bosch Common Rail Injection System. The comparison between the computed and measured injection parameters showed good matching. 展开更多
关键词 Diesel Engine Fuel Injection System
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