salama M abdelhady | CIC (original) (raw)

Papers by salama M abdelhady

Advanced Powder Technology, Mar 1, 2010

The force propagation speed in granular matter is a very difficult property to be measured. A new... more The force propagation speed in granular matter is a very difficult property to be measured. A new technique has been developed to calculate the force propagation speed in granular matter based on measuring experimentally the contact time. The contact time for a particle hitting a bed of particles is estimated as the time taken for a particle to strike a bed of particles till the time of its ejection, and it is calculated using the discrete element method. The speed of force propagation in a bed of particles is estimated by plotting the dependence of the path length of the contact force on the contact time and finding the gradient of such dependence. Such approach leads to accurate results if the impact speed is below the yield velocity, i.e. no plastic deformations. It is found that the force propagation speed in spherical granular matter is proportional to the impact speed of the incident particle, which is different from force propagation in continuum matter. It is also found that the propagation speed is dependent on the material and diameters ratio of the interacting particles, but it is not dependent on the number of bed layers. The propagation speed in granular matter is normalized by dividing it by a reference propagation speed, i.e. the propagation speed at an impact speed of 1 m/s. It is found that the normalized propagation speed is independent of the material and diameter of the interacting particles, but it is logarithmically proportional to the impact speed. The proportionality constant is equal to 0.16, which can be taken as a universal constant for force propagation in spherical granular matter.

Applied Thermal Engineering, Aug 1, 2009

Removal of particulate fouling layers by externally injected particles as a function of flow dire... more Removal of particulate fouling layers by externally injected particles as a function of flow direction with respect to gravity is investigated experimentally. Three orientations of flow have been investigated, horizontal flow, upward flow and a downward flow. It is found that fouling starts at the point of stagnation irrespective of the flow direction, and

Journal of Electrostatics, 2017

World Journal of Neuroscience, 2023

Neurologists define the transmission of nerve impulses across the membranes of the neural cells a... more 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.

Energy, Aug 1, 2012

The use of wind as an energy source is becoming popular because of its nonpolluting and renewable... more The use of wind as an energy source is becoming popular because of its nonpolluting and renewable features. There is an urgent request to develop site-based estimation on wind engineering, which can be used for optimal design of wind turbines and wind farming. The wind speed for Zafarana Project in Suez Gulf, namely Site-3, based on monthly averaged data for one year as well as every 10 minutes for two days, one day in summer season and one day one winter season have been analyzed to estimate the most appropriate method to find Weibull distribution parameters for this site. The investigated methods are the mean wind speed method, the maximum likelihood method, the modified maximum likelihood method, the graphical method and the power density method. These methods results have been compared with the provided data to find their accuracy based on the root mean square errors. From the obtained results, the mean wind speed and the maximum likelihood method are recommended in estimating the wind speed distribution for the studied site in Zafarana wind farm.

Case Studies in Thermal Engineering

Electric Field in Advancing Science and Technology [Working Title]

According to an analogy between the laws that characterize the flow of heat, electric charges, an... more According to an analogy between the laws that characterize the flow of heat, electric charges, and magnetic flux, and to results of Faraday’s experiments, the electric charge and the magnetic flux were defined and visualized in previous research as energy flux in the form of electromagnetic waves (EM) that have electric or magnetic potentials and that all potentials can be measured by the Volt. The proofs of such statements will be enlightened in this chapter. Recognizing the nature of electric charges as energy; the electric current, defined traditionally as the rate of flow of electric charges would have the unit of power, i.e., Watt. As the ammeter does not measure the power but measures, according to its definition, the quotient of the electric power divided by the electric potential, then its unit should be “Watt/Volt.” So, the ammeter does not measure an electric current if it is defined as the rate of flow of electric charges. However, the unit “Watt/Volt” of the ammeter’s re...

International Journal of Applied Energy Systems

Journal of Electrostatics, 2017

The International Conference on Mathematics and Engineering Physics, 2016

The aim of this Paper is to carry out an analytical and experimental study of a solar power tower... more The aim of this Paper is to carry out an analytical and experimental study of a solar power tower plant in the Egyptian environment in order to study the technical and economic feasibility of this kind of power generation. In this way, a parametric study of such plant is carried out in a comparative way with an already existing commercial power plant, PS 10 in Spain, to investigate performance of such kind of plants in the Egyptian environment. The site of Aswan has been chosen to simulate the proposed plant. However, a site in Helwan is used to carry out the experimental work that verifies the selected solar data in Egypt. As a conclusion from the analytic parametric study, the energy-exergy analysis, the experimental work; it is found that it is very feasible, technically and economically, to use solar power tower plant as the most suitable CSP technology in Egypt. The found analytical and experimental results in this thesis can be used as a guide and a reference for planning a solar tower power plant to be installed in Egypt in future. This includes the site selection, design parameters and procedures, heliostat field distribution, tower height, the components to be locally manufactured, required performance, the suitable output power and the levelized energy cost.

Energy and Buildings, 2011

This study presents a proposed idea about making use of the thermal energy rejected by the conden... more This study presents a proposed idea about making use of the thermal energy rejected by the condenser in a water-cooled split-airconditioning systems to decrease the relative humidity of the cold air supplied by such air conditioners. Most of split air-conditioner systems cool air without controlling its humidity. An amount of heat is rejected from the air conditioner, through the condenser, into the surrounding in order to allow the refrigerant to cool down and condense, thus, part of the lost energy can be exploited to decrease the relative humidity of the sub-cooled air that leaves the evaporator as saturated humid air. Four variables, viz. the coil type (single or double), the amount of flowing water, water, temperature, and the cooled air velocity were studied to find out the optimum conditions required for this purpose. The requisite amount of heat that may adjust the relative humidity of the conditioned air was also determined. The experimental results suggest an optimum design of a heat exchanger for performing the use of the heat rejected from the condenser to achieve the aim. As a result, the proposed heat recovery concept can be worthily adopted to achieve economic results in large-scale systems.

Energy, 2012

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2008

An ejector is a pumping device that uses a high-speed primary fluid jet to entrain a secondary st... more An ejector is a pumping device that uses a high-speed primary fluid jet to entrain a secondary stream. The pumping action is due to the exchange of momentum between the primary and secondary streams. The air ejectors are widely used in mixing systems and many engineering applications. The purpose of the present work is to study experimentally the effects of using different numbers of nozzles with various geometric variables on the performance of the air ejector. The test rig, which is designed particularly for this study, is constructed so that the overall performance of the air ejector can be measured under various operating conditions. To the best knowledge of the authors, there is no published work concerning the study of all the geometric variables with different numbers of nozzles, showing their effect on the ejector performance. The experimental investigations consist of the performance measurements for 52 ejectors. They are classified into three main groups The following conc...

Journal of Physical Science and Application

Thermodynamics is a branch of physics which deals with the energy flow into systems. There are tw... more Thermodynamics is a branch of physics which deals with the energy flow into systems. There are two principal laws of thermodynamics which are described on separate slides. The first law of thermodynamics relates to the transfer of various forms of energy, as heat, electric, magnetic and chemical energies to produce mechanical work. This law is sometimes taken as the definition of internal energy, and introduces an additional state variable, enthalpy. The first law of thermodynamics allows for many possible states of a system to exist. But experience indicates that there is only one direction for natural processes to proceed. This leads to the second law of thermodynamics and the definition of another state variable called entropy. The second law stipulates that the total entropy of a system plus its environment cannot decrease; it can remain constant for a reversible process but must always increase for irreversible or natural processes. However, the limited number of authors is concerned by systems that involve the transfer of electric and magnetic energies in addition to the flow of heat in studying a general thermodynamic system. The submitted review follows an entropy approach that introduces clear definitions of the electric charge and magnetic flux to clarify ambiguities of the natures of such fluxes in literature. So, the first and second laws of thermodynamics are applied on thermo-electromagnetic processes that embrace the flow of mechanical, thermal, electric, and magnetic energies into systems that involve fluids or solids. Accordingly, it was possible to modify redundancies in the SI system of units. Following the entropy approach, it was possible to cast the Maxwell's equations into an energy frame of reference to explain the discovered Tesla's wireless power transmission as "Electrical Radiant Energy", and the MIT discovery of wireless power transmission of the magnetic flux as "Evanescent Waves" and to clarify fuzziness of the duality confusion by specifying a unique property for the electron as a particle and a unique property for the light as a wave. Consequently, it was possible also to prove that the semiconductors efficiency responds mainly to the concentration of the incident solar energy, i.e. incident solar energy per unit area, and it is partially influenced by the wavelength.

We present an advanced review of thermodynamics of electromagnetic systems that has effective app... more We present an advanced review of thermodynamics of electromagnetic systems that has effective applications. The review highlights a previously introduced entropy approach that found plausible explanations of new discoveries in the field of electromagnetism. We started by studying the similarity and reversible interchangeability of heat, electric current and magnetic flux. Then, it is presented a fundamental energy equation that embraced the thermal, mechanical, electrical and magnetic potentials. According to the principles of entropy production, it is reviewed modified statements of the second law of thermodynamic that proved the existence of irreversibilities and entropy generation in transfer of electric and magnetic energies through substantial differences of their driving potentials similar to irreversibilities and entropy generation encountered by flow of the thermal energy. Accordingly, the Maxwell’s equations of electromagnetic waves were casted into an energy frame of refer...

According to a previous review of thermodynamics of electromagnetism, the Maxwell’s wave Equation... more According to a previous review of thermodynamics of electromagnetism, the Maxwell’s wave Equations were casted into an energy frame of reference by replacing the time in these Equations by entropy. Such transformation helps in redefining the energy quantum and realizes the representation of a postulated definition of the electric charge and magnetic flux as electromagnetic waves of electric or magnetic potentials. In this paper; it will be discussed experimental results that found the electric charge as electrified light and the magnetic flux as magnified light. Such definitions will be used here as a key to delete the duality confusion, to find a new photon’s wave function and to discuss the need to the Schrodinger’s particle-wave function. The introduced definitions will be used also to find innovative solutions of found unsolved problems in physics and to solve the inconsistency between classical physics, quantum mechanics and the special relativity. Finally it will be discussed ...

The International Conference on Electrical Engineering, 2008

It is revised here some previously accepted definitions regarding interactions between atomic par... more It is revised here some previously accepted definitions regarding interactions between atomic particles and electromagnetic waves. It was found that such definitions were not offering plausible explanations for newly discovered phenomena as Kerr effect, duality property of atoms, colored charges and other related phenomena. Hence, we followed a fuzzy approach to postulate new definitions for electromagnetic waves, electrons, charges and magnetism that may lead to a better understanding of such discovered phenomena. An interesting experiment was elaborated in this investigation to prove the trueness of the postulated definitions. The found results of such experiment and the results of Faraday's discovery with dielectrics as well as the analogy between heat flow, electric current and magnetic flux affirm the logic of the postulated definitions. The introduced approach offers more plausible explanations of many phenomena in the field of electromagnetism and atomic particles. The postulated definitions have led also to valuable scientific-conclusions in this field.

The International Conference on Applied Mechanics and Mechanical Engineering, 2010

In recent years; scientific literatures as textbooks and journals have considered the SI system o... more In recent years; scientific literatures as textbooks and journals have considered the SI system of units as undesirable in fundamental researches because the SI units of many physical quantities do not correspond to current scientific theories. This paper offers a new system that eliminates redundancies found in the SI system by involving physical concepts that found, by following an entropy approach, common features of the thermal, electrical and magnetic fluxes. The electric potential and the magnetic potentials were expressed as qualities of the electric charge and the magnetic flux in analogy to the temperature that represents, as stated by the second law of thermodynamics, the quality of heat. According to published experimental results; the electric or the magnetic potentials generates an E.M.F. through an Al-Fe thermocouple similar to the E.M.F. generated by a temperature difference in such thermocouple. So; the introduced system considers the generated E.M.F. as a unique dimensionless scale for measuring the qualities or the potentials of the considered energy fluxes. Accordingly, the introduced system of units is based only on three dimensions; E, L, and T, and four fundamental units; Joule, meter, second and the Volt. The postulated system of units introduces also a modified fundamental thermodynamic-equation that offers plausible explanations of the prevailing energy-system interactions in the fields of thermodynamics, electromagnetism and thermo-chemistry

Advanced Powder Technology, Mar 1, 2010

Applied Thermal Engineering, Aug 1, 2009

Journal of Electrostatics, 2017

World Journal of Neuroscience, 2023

Energy, Aug 1, 2012

Case Studies in Thermal Engineering

Electric Field in Advancing Science and Technology [Working Title]

International Journal of Applied Energy Systems

Journal of Electrostatics, 2017

The International Conference on Mathematics and Engineering Physics, 2016

Energy and Buildings, 2011

Energy, 2012

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2008

Journal of Physical Science and Application

The International Conference on Electrical Engineering, 2008

The International Conference on Applied Mechanics and Mechanical Engineering, 2010

As the photons of the solar irradiance fall on the free electrons of the PV cells, it mobilizes t... more As the photons of the solar irradiance fall on the free electrons of the PV cells, it mobilizes the electrons, according to Einstein’s description, and causes a flow of electric current. It has been found that the electric current from a silicon PV cell is proportional to the incident solar radiation such that there should not be a limit of the mobilized free electrons. Accordingly, the performance of such PV cell represents a very confusing phenomena, because the number of free electrons from a PV cell is limited while the generated electric current should have unlimited number. It has been shown that considering the electric current as a flow of electrons is contradicted by many experimental measurements. On the other hand; there is a postulated nature of electric current as a flow of electromagnetic waves of electric potential that may solve such contradictions. So, the PV cell should be considered as a device through which the incident solar radiation of a convenient energy which depends on its wavelength, may gain its junction’s electric potential during the flow through it. So, increasing the incident solar radiation will lead to increase the output current without any limitation.