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Full-Text Articles in Engineering
Estimation Of The Entropy Of Vaporization At The Normal Boiling Point For Azeotropic Mixtures Containing Water, Alcohol Or Acetic Acid, Yasar Demirel
Estimation Of The Entropy Of Vaporization At The Normal Boiling Point For Azeotropic Mixtures Containing Water, Alcohol Or Acetic Acid, Yasar Demirel
YASAR DEMIREL
The entropy of vaporization at the normal boiling point has been estimated for binary and ternary azotropic mixtures containing water, alcohol or acetic acid. For this purpose, the Lee±Kesler correlation, developed originally for pure substances, is used with the appropriate mixing rules to estimate the heat of vaporization of the mixtures. Estimations for the entropy of vaporization of the 97 binary and 78 ternary mixtures are expressed as function of the ratio of the normal boiling point to average molecular weight. These expressions predict the entropy of vaporization satisfactorily, with less than 5% average deviation.
Entropy Generation In A Rectangular Packed Duct With Wall Heat Flux, Yasar Demirel, R. Kahraman
Entropy Generation In A Rectangular Packed Duct With Wall Heat Flux, Yasar Demirel, R. Kahraman
YASAR DEMIREL
The entropy generation due to heat transfer and friction has been calculated for fully developed, forced convection flow in a large rectangular duct. packed with spherical particles, with constant heat fluxes applied to both the top (heated) and bottom (cooled) wall. An approximate analytical expression for the velocity profile developed for packed bed with H/dp > 5 has been used together \vith the energy equation of fully developed flow to calculate the nonisothermal temperature profiles along the flow passage. The velocity prolile takes into account the increase in the velocity near the wall due to the higher voidage in this region …
Estimation Of The Entropy Of Vaporization At The Normal, Yasar Demirel
Estimation Of The Entropy Of Vaporization At The Normal, Yasar Demirel
YASAR DEMIREL
The entropy of vaporization at the normal boiling point has been estimated for binary and ternary azotropic mixtures containing water, alcohol or acetic acid. For this purpose, the Lee±Kesler correlation, developed originally for pure substances, is used with the appropriate mixing rules to estimate the heat of vaporization of the mixtures. Estimations for the entropy of vaporization of the 97 binary and 78 ternary mixtures are expressed as function of the ratio of the normal boiling point to average molecular weight. These expressions predict the entropy of vaporization satisfactorily, with less than 5% average deviation
Nanometer-Scale Probing Of Potential-Dependent Electrostatic Forces, Adhesion, And Interfacial Friction At The Electrode/Electrolyte Interface, Shane D. Campbell, Andrew C. Hillier
Nanometer-Scale Probing Of Potential-Dependent Electrostatic Forces, Adhesion, And Interfacial Friction At The Electrode/Electrolyte Interface, Shane D. Campbell, Andrew C. Hillier
Andrew C. Hillier
The atomic force microscope (AFM) was used to examine the influence of an applied electrochemical potential on the interfacial properties of the electrode/electrolyte interface. Measurements of electrostatic force, adhesion, and friction coefficient were performed at two different electrode surfaces: glassy carbon anda thin film of sulfonate-derivatized poly(aniline) (SPANi). At the carbon electrode, changes in electrostatic force between probe and substrate exhibited a potential-dependent transition from repulsive to attractive values at potentials negative and positive of the potential of zero charge (Epzc). Simultaneous measurements of tip-substrate adhesion and friction coefficient showed a change from low to high values over the same …
The Physicochemical Origins Of Coincident Epitaxy In Molecular Overlayers: Lattice Modeling Vs Potential Energy Calculations, Julie A. Last, Daniel E. Hooks, Andrew C. Hillier, Michael D. Ward
The Physicochemical Origins Of Coincident Epitaxy In Molecular Overlayers: Lattice Modeling Vs Potential Energy Calculations, Julie A. Last, Daniel E. Hooks, Andrew C. Hillier, Michael D. Ward
Andrew C. Hillier
The physicochemical basis for epitaxial stabilization of coincident molecular overlayers is illustrated by comparison of optimum overlayer-substrate configurations calculated with potential energy (PE) methods and a simple geometric lattice misfit modeling algorithm (EpiCalc) that neglects molecular orientations and intermolecular potentials. Using â-bis(ethylenedithio)tetrathiafulvalene triiodide (â-ET2I3), perylenetetracarboxylic diimide (PTCDI), and perylenetetracarboxylic dianhydride (PTCDA) overlayers on a graphite substrate as examples, both methods predict identical optimum azimuthal overlayer orientations for each overlayer that also agree with experimental observations. PE calculations for three hypothetical PTCDA overlayers, with identical lattice parameters but different molecular orientations, predict coincidence at the same azimuthal orientation for all overlayers. …
Entropy Generation In A Rectangular Packed Duct With Wall, Yasar Demirel, R. Kahraman
Entropy Generation In A Rectangular Packed Duct With Wall, Yasar Demirel, R. Kahraman
YASAR DEMIREL
The entropy generation due to heat transfer and friction has been calculated for fully developed forced convection flow in a large rectangular duct packed with spherical particles with constant heat fluxes applied to both the top heated and bottom cooled wall.
Energetic And Exergetic Efficiency Of Latent Heat Storage System For Greenhouse Heating, Yasar Demirel, A Bascetincelik, Hh. Ozturk, H.O. Paksoy
Energetic And Exergetic Efficiency Of Latent Heat Storage System For Greenhouse Heating, Yasar Demirel, A Bascetincelik, Hh. Ozturk, H.O. Paksoy
YASAR DEMIREL
In this research, solar energy has been stored using the paraffin with the latent heat technique for heating the plastic greenhouse of 180 m2.
Packing Size Anetric Heating, Yasar Demirel, B.A. Abu Al-Saud, H.H. Ali, Y. Makkawi
Packing Size Anetric Heating, Yasar Demirel, B.A. Abu Al-Saud, H.H. Ali, Y. Makkawi
YASAR DEMIREL
An experimental and numerical investigation of fully developed forced convection in large rectangular packed ducts is presented. The horizontally oriented ducts have the length-to-separation distance ratio of L/H=16 with two aspect ratios of W/H=8 and 4. A constant heat flux is supplied to the top wall, while the bottom and side walls are insulated. Packing of hard polyvinyl chloride Raschig rings with outside diameters of 48 and 34 mm, and expanded polystyrene spheres with diameters of 48, 38 and 29 mm are used in the air flow passage. The pressure drop, the heat flux, axial and transverse temperature profiles of …
Enhancement Of Convection Heat-Transfer, Yasar Demirel, H.H. Al-Ali, B.A. Abu-Al-Saud
Enhancement Of Convection Heat-Transfer, Yasar Demirel, H.H. Al-Ali, B.A. Abu-Al-Saud
YASAR DEMIREL
Characteristics of wall-to-air heat transfer for a fully developed forced convection have been studied in a large rectangular packed duct with 160 cm heated length, 40 cm width, and for low bed equivalent diameter to particle diameter ratio. The separation distance between the top and bottom walls is 10 cm. A uniform heat ¯ux is supplied at the top wall, while the bottom wall is insulated. Raschig rings in two and spherical packing in three sizes have been used in the air ¯ow passage to investigate the enhancement of heat transfer due to packing. Temperature pro®les for the steady and …
Irreversibility Profiles In A Circular Couette Flow Of Temperature Dependent Materials, Yasar Demirel
Irreversibility Profiles In A Circular Couette Flow Of Temperature Dependent Materials, Yasar Demirel
YASAR DEMIREL
The irreversibility distributions have been calculated for a circular Couette flow of ethylene glycol with temperature dependent thermal conductivity and viscosity. The approximate series solutions of velocity and temperature fields are used to obtain the gradients to calculate the spatial entropy generation rate with narrowing gap of the Couette. It was found that the irreversibility distribution is relatively more uniform for a narrow-gap Couette.
Uso Del Diseño Experimental En La Obtención De Alúmina Activada Para La Remoción De Fluoruros Del Agua. Parte Ii: Resultados, R. Trejo-Vázquez, A. Bonilla-Petriciolet, L. Castañón-Ayala, J.M. Ruvalcaba Medina, H. Juárez Medina
Uso Del Diseño Experimental En La Obtención De Alúmina Activada Para La Remoción De Fluoruros Del Agua. Parte Ii: Resultados, R. Trejo-Vázquez, A. Bonilla-Petriciolet, L. Castañón-Ayala, J.M. Ruvalcaba Medina, H. Juárez Medina
Adrian Bonilla-Petriciolet
En esta segunda parte se muestran los resultados obtenidos a partir del esquema metodológico presentado en la primera parte para la preparación de alúmina activada destinada a la remoción de fluoruros del agua. Bajo las condiciones de preparación establecidas, se obtuvo un porcentaje de remoción de fluoruros del 65,25% para agua sintética con concentración inicial de 2 partes por millón de fluoruros, el cual es mayor al obtenido por una alúmina comercial que se probó bajo las mismas condiciones. Lo anterior sugiere que el proceso de preparación del adsorbente desarrollado según esta metodología es técnicamente satisfactorio y podría resultar interesante …