Authors:Hussein M. Maghrabie; M. Attalla; H.E. Fawaz; M. Khalil Pages: 285 - 296 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): Hussein M. Maghrabie, M. Attalla, H.E. Fawaz, M. Khalil A computational study of cooling in-line array of heated obstacles simulating electronic components by jet impingement in cross-flow (JICF) has been investigated using RNG k-ε turbulence model. The jet position has been changed to impinge each obstacle consecutively at different jet-to-channel Reynolds number ratios, Re j/Re c =1, 2, and 4. The main flow structure, the static pressure, local and average Nusselt numbers as well as the thermal enhancement factor have been investigated. The results show that there is a significant variation between the flow structures around an obstacle when subjected to JICF or CF. The friction factor for JICF is greater than that for cross-flow only (CF) by 88% at the first jet position and Re j/Re c =4. The irregular distribution of local Nusselt number ( Nu ) on the impinged obstacle is moderated by increasing the Reynolds number ratios. Increasing Reynolds number ratio increases the average Nusselt number ( Nu ‾ ) of the downstream obstacles and decreases it for the upstream obstacles. The increment of Nu ‾ for whole array for JICF than CF is about 26% at JP3 and Re j/Re c =4. Moreover, the highest value of thermal enhancement factor is attained at JP3 and it equals 12% for Re j/Re c =4.
Authors:Magdi El-Messiry; Shaimaa El-Tarfawy; Rania El Deeb Pages: 297 - 307 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): Magdi El-Messiry, Shaimaa El-Tarfawy, Rania El Deeb Fiber reinforced concrete (FRC) has become increasingly applied in civil engineering in the last decades. Natural fiber fabric reinforced cement composites are considered to prevent damage resulting from an impact loading on the cementite plate. Flax woven fabric that has a high energy absorption capability was chosen. To increase the interfacial shear properties, the fabric was pultruded with different matrix properties that affect the strength and toughness of the pultruded fabric. In this study, three fabric structures are used to increase the anchoring of the cement in the fabric. The compressive strength and the impact energy were measured. The results revealed that pultruded fabric reinforced cement composite (PFRC) absorbs much more impact energy. PFRC under impact loading has more micro cracks, while plain cement specimen shows brittle failure. The compressive test results of PFRC indicate that flax fiber fabric polymer enhanced compressive strength remarkably. Fiber reinforcement is a very effective in improving the impact resistance of PFRC. The study defines the influence factors that control the energy dissipation of the composite, which are the hardness of the polymer and the fabric cover factor. Significant correlation between impact energy and compressive strength was proved.
Authors:Ali A. Elabd; EL-Sayed M. El-Rabaie; Abdelaziz T. Shalaby Pages: 309 - 312 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): Ali A. Elabd, EL-Sayed M. El-Rabaie, Abdelaziz T. Shalaby Studying of single electronics should consider both the temperature and the circuit capacitance as being the most important parameters that affect the behavior of SET devices. In this letter, the delay and the output voltage level in the single electron tunneling inverter are investigated for a wide range of temperature and load capacitance. Due to the stochastic nature of the electron transports in single electronics, the results are considered to be the average of many Monte Carlo computations.
Authors:S. Ashok Kumar; T. Shanmuganantham Pages: 313 - 317 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): S. Ashok Kumar, T. Shanmuganantham A new clover slot antenna operating at 2.45GHz Industrial, Scientific, and Medical (ISM) band for biomedical applications is presented and experimentally verified. By putting a single feed and truncating clover slots with extra perturbation, good performance of polarization can be achieved. Also, the miniaturized size of the proposed antenna is 14×12×0.8mm3 by utilizing the clover shaped slots. A broader bandwidth of 2.5GHz is obtained for reflection coefficient less than −10dB. In addition, the radiation pattern of proposed antenna exhibits the maximum gain of −6dBi.
Authors:Azza Mohamed Elleboudy; Nasser Mosleh Saleh; Amany Gouda Salama Pages: 319 - 326 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): Azza Mohamed Elleboudy, Nasser Mosleh Saleh, Amany Gouda Salama Performance of geogrid in gravel roads subjected to repeated loads was investigated through laboratory testing in the laboratory of faculty of engineering at Shoubra and finite element analysis. Twenty two laboratory model tests under cyclic loading were conducted on road sections consisting of base course layer with and without geogrid reinforcement overlaying weak subgrade. Parameters investigated included base layer thickness, grid aperture size, geogrid tensile strength, number of geogrid layers, and geogrid location. The experimental results indicated that the inclusion of one geogrid sheet placed at the base of course layer reduced the vertical deformation by about 18 to 64% depending on the base course layer thickness. The vertical deformation depth increased rapidly during the initial load cycles; thereafter the rate of settlement is reduced as the number of loading cycles increased. The most effective location of geogrid was found to be in the top quarter of the base course layer. When the results of the laboratory tests were compared with the analytical solution using finite element program ABAQUS, the FE results were in good agreement with the experimental test results.
Authors:Walaa Y. El-Nashar Pages: 327 - 332 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): Walaa Y. El-Nashar Drains coverings (DC) are used to pass the small discharge to function as bridge. There are two types for coverings, pipe or box type. The main problems which lead to a perceived need to cover a drain are: to minimize the adverse impact of a polluted drain, especially close to residential areas, need to use the land area occupied by the drain for an access road or some other use, poor soil stability leading to bank failure, and to protect them from pollution. DC has many effects on the environment. The main objective of this study is using value engineering (VE) to explain the effects of DC on the environment. Life cycle cost (LCC) methodology is used also to compare between two alternatives for drains. These alternatives are (i) surface drains, (ii) drains coverings. Results show that the best alternative for the environment is drains coverings.
Authors:Mohamed M. Hassan; Mohamed A. Teamah; Wael M. El-Maghlany Pages: 333 - 343 Abstract: Publication date: September 2017 Source:Alexandria Engineering Journal, Volume 56, Issue 3 Author(s): Mohamed M. Hassan, Mohamed A. Teamah, Wael M. El-Maghlany Impinging jet is one of various methods of cooling with the ability to achieve high heat transfer rates and improve average surface’s Nusselt number. This method has vast industrial applications including integrated use in solar collectors, gas turbine cooling, refrigeration, air conditioning and electronics cooling. A numerical study is conducted to study the effects of using nanofluids on impinging slot jet over a flat plate with a ribbed surface. The main objective of the study was to investigate the possibility of improving the overall heat transfer rate by focusing on the improvements in the local and average surface Nusselt number values. Several parameters effects are studied including Solid Volume Fraction, Richardson number and Reynolds number. These results indicated a marked improvement in average Nusselt number with the increase in the solid volume fraction. Also, there is an amended value when the buoyancy effect is dominant over the whole domain. The results are shown in the form of streamlines, isotherms and Nusselt numbers contra other variables. The current work was simulated using a FORTRAN CFD Code, which discretizes the non-dimensional forms of the governing equations utilizing the finite volume method and solving the consequent algebraic equations using Gauss-Seidel method Utilizing TDMA.
Authors:S.I. Nipanikar; V. Hima Deepthi; Nikita Kulkarni Abstract: Publication date: Available online 17 October 2017 Source:Alexandria Engineering Journal Author(s): S.I. Nipanikar, V. Hima Deepthi, Nikita Kulkarni With the growth of information technology, information security is a major concern in the interactive environment, where there is no security for the messages send to and from the receiver. A technology named image steganography has been employed that ensures security to the covert communication and safeguarding the information. Image steganography hides the secret message in any of the recipient images and sends the secret message such that the message is visible only to the sender and the receiver. This paper proposes a method for image steganography using sparse representation, and an algorithm named Particle Swarm Optimization (PSO) algorithm for effective selection of the pixels for the purpose of embedding the secret audio signal in the image. PSO-based pixel selection procedure uses a fitness function that depends on the cost function. Cost function calculates the edge, entropy, and intensity of the pixel for evaluating fitness. Simulation has been done and comparison of the PSO with the other existing methods in terms of Peak-Signal-to-Noise-Ratio (PSNR) and Mean Square Error (MSE) determines the proposed PSO, as an effective method. The proposed method achieved a better PSNR and MSE values of 47.6 dB and 0.75 respectively.
Authors:Davoud Sedighizadeh; Houman Mazaheripour Abstract: Publication date: Available online 16 October 2017 Source:Alexandria Engineering Journal Author(s): Davoud Sedighizadeh, Houman Mazaheripour The vehicle routing problem is the basic problem of distribution planning which seeks to find the best route with minimum displacement cost considering the number of customers, their constraints, and number and capacity of the available vehicles. In this study, the traveling salesman problem and vehicle routing models are firstly described and, after that, the multi objective vehicle routing model is proposed to consider the Precedence constraints among customers. There are different meta-heuristic algorithms that can solve such NP-hard problems. In the present study, a solver algorithm is proposed which is based on a combination of the particle swarm optimization and the artificial bee colony algorithms. Additionally, by presenting an operational sample, using data of customers in a region, considering different constraints of the problem and its functions, and using penalty method as well as additional segmentation constraint method, the best vehicle route is obtained and the results of each algorithm together with its hybrid algorithm are demonstrated.
Authors:Pouria Assari Abstract: Publication date: Available online 13 October 2017 Source:Alexandria Engineering Journal Author(s): Pouria Assari The current work presents a computational scheme to solve weakly singular integral equations of the second kind. The discrete collocation method in addition to the moving least squares (MLS) technique established on scattered points is utilized to estimate the solution of integral equations. The MLS scheme approximates a function without mesh refinement over the domain that includes a locally weighted least squares polynomial fitting. The discrete collocation technique for the approximate solution of integral equations results from the numerical integration of all integrals in the method. We utilize an accurate quadrature formula based on the use of non-uniform composite Gauss-Legendre integration rule and employ it to compute the singular integrals appeared in the approach. The proposed scheme does not require any meshes, so it can be called as the meshless local discrete collocation (MLDC) method. Error analysis is also given for the method. Illustrative examples are shown clearly the reliability and efficiency of the new scheme and confirm the theoretical error estimates.
Authors:Hagar Alm El-Din; Medhat Elkelawy; Abd Elnaby Kabeel Abstract: Publication date: Available online 12 October 2017 Source:Alexandria Engineering Journal Author(s): Hagar Alm El-Din, Medhat Elkelawy, Abd Elnaby Kabeel In the present analysis, the dissemination of dimethyl ether (DME) asan alternative fuel with the charged air inside the HCCI engine chamber until accomplishing the burning procedure have been numerically expected by utilizing CFD with detailed chemical kinetics mechanism. The physical technique of the ignition and pollution arrangement in the engine barrel with DME fuel is examined with a developed hydrocarbon reaction mechanism at various HCCI engine loads. The mechanism is including 81 chemical species and 362 basic chemical reactions. Along these lines, the used CFD/discipline code predicts the admittance of the fuel spray, ignition, and pollutant development of DME asa biodiesel fuel. The split injection technique has been used to inject the dimethyl ether remotely at the engine admission tube. The in-cylinder flow field enhances farther the engine chamber fuel/air distribution. The outcomes showed that the blend of DME fuel with charged air is exact and efficient to accomplish the in-barrel blend homogeneity. It is anticipated that, under every engine working condition the production of the methyl radical is considered as imperative part in dimethyl ether pyrolysis and oxidation. In the meantime, the formaldehyde sub-component is a huge division of the general dimethyl ether (DME) ignition system.
Authors:A.E. Kabeel; Z.M. Omara; F.A. Essa; A.S. Abdullah; T. Arunkumar; Ravishankar Sathyamurthy Abstract: Publication date: Available online 12 October 2017 Source:Alexandria Engineering Journal Author(s): A.E. Kabeel, Z.M. Omara, F.A. Essa, A.S. Abdullah, T. Arunkumar, Ravishankar Sathyamurthy Effects of utilizing nanomaterial on the solar still productivity investigated experimentally. Cuprous oxides (CuO) chosen asa nanoparticles material. The nanoparticles added to the black paint of the solar still walls to enhance the solar still performance. Experiments conducted with cuprous oxide nanoparticles weight concentrations ranged from 10% to 40%. It is found that adding nanoparticles to paint increase heat transfer rate and saline water temperature. Solar still productivity of the proposed system is higher than that for the conventional still. Results acquired that utilizing CuO nanoparticles boosted the distillate by 16% and 25% as compared to the conventional solar still (CSS) at weight fraction concentration of 10% and 40%, respectively. Payback period of the distillation system for the modified still using CuO nanomaterials is about 96days, at weight fraction 10%, which is considerable as compared by 89days for CSS.
Authors:R. Nagendra; T. Venkateswarulu Abstract: Publication date: Available online 9 October 2017 Source:Alexandria Engineering Journal Author(s): R. Nagendra, T. Venkateswarulu In this paper, a novel dual band microstrip patch antenna based on composite patch antenna and radiating part. By selecting a suitable offset feed position, it is feasible to provide 50 Ω characteristic impedance and thus making better impedance matching. The proposed antenna has been improved broader bandwidth by using RT Duroid substrate. The radiating part is plays a important role in creating a lower operating band (2.45 GHz) in addition to achieve miniaturization. The proposed antenna has to be fabricated with RT/Duroid substrate and dimensions of 19×22×0.8 mm. The measured −10 dB bandwidth of 200 MHz at 3.45 GHz and 990 MHz at 5.45 GHz, which is quite useful for Industrial, Scientific and Medical (ISM) and WLAN applications.
Authors:Dina Mamdouh; Nassar Hanan Gamil Elsayed Abstract: Publication date: Available online 4 October 2017 Source:Alexandria Engineering Journal Author(s): Dina Mamdouh Nassar, Hanan Gamil Elsayed Informal Settlements and urban informality is a serious and common problem in Third World countries. These settlements are not marginal actors in the real estate market. They play an important role affecting greatly the housing supply and demand market. In Egypt, Informal Settlements emerged in and around big cities since the sixties of the twentieth century, due to natural growth and the flux of rural-urban migration. Alexandria- as the second biggest city in Egypt after Cairo- is witnessing a rapid population increase, therefore monitoring Informal Settlements locations, expansion and growth is important for possible urban development. This study focuses on the continued transformation of Alexandria’s backdrop productive agricultural land into Informal Settlements causing serious encroachment on agricultural land. The study intends to find solutions through examining local needs and potentials for a selected case study named “Houd 10”. This case is an example that sheds the light on means that can be utilized in Informal Settlements to improve living conditions and reach socio-economic potentials. Analyses of the current situation and challenges at Houd 10 are examined on three levels; economic, social and environmental. The research also highlights the role of non-profit organizations and social participation for developing such areas.
Authors:Jaber Valizadeh; Ehsan Sadeh; Habibollah Javanmard; Hanieh Davodi Abstract: Publication date: Available online 3 October 2017 Source:Alexandria Engineering Journal Author(s): Jaber Valizadeh, Ehsan Sadeh, Habibollah Javanmard, Hanieh Davodi The main purpose of this study is to analyze the effect of energy prices on consumption energy consumption efficiency in the petrochemical industry in Iran during the period 1994–2012. Also, in order to avoid the bias (bias, error) omitted variables, a number of determinants of energy consumption efficiency, i.e. the ratio of workforce to energy, the ratio of capital to total energy consumption, the price of labor, cost of capital and technology are used within the framework of an econometric model. For this purpose, based on the Cobb-Douglas production function, extended average energy consumption efficiency in the petrochemical industry is measured. Then, using the approach ARDL (Autoregressive Distributed Lag Model), the effect of explanatory variables on the dependent variable has been analyzed. The results show that energy consumption efficiency index in the petrochemical industry of Iran has a long-term trend growing; however, this index has been relatively high volatility. In addition, according to the findings, energy prices had a significant and positive effect on energy consumption efficiency. Also, the ratio of workforce to total energy consumption, the ratio of capital to total energy consumption and the price of capital and technology have a significant and positive effect on total energy consumption efficiency in the petrochemical industry.
Authors:M.J. Uddin; A. Sohail; O. Anwar Bég; A.I.Md. Ismail Abstract: Publication date: Available online 29 September 2017 Source:Alexandria Engineering Journal Author(s): M.J. Uddin, A. Sohail, O. Anwar Bég, A.I.Md. Ismail In this paper, we have examined the magnetohydrodynamic flow of a nanofluid past a radiating sheet. The Navier velocity slip, Newtonian heating and passively controlled wall boundary conditions are considered. The governing equations are reduced into similarity equations with the help of Lie group. A collocation method is used for simulation. The influence of emerging parameters on velocity, temperature, nanoparticle volumetric fraction profiles, as well as on local skin friction factor and local Nusselt number is illustrated in detail. It is found that the friction (heat transfer rate) is lower (higher) for passively controlled boundary conditions as compared to the case of an actively controlled boundary condition. The magnetic field effects decrease both the skin friction and the rate of heat transfer. The findings are validated with existing results and found an excellent agreement. The model explores new applications in solar collectors with direct solar radiative input using magnetic nanofluids.
Authors:Hariram Venkatesan; Seralathan Sivamani; Kunal Bhutoria; Harsh H. Vora Abstract: Publication date: Available online 28 September 2017 Source:Alexandria Engineering Journal Author(s): Hariram Venkatesan, Seralathan Sivamani, Kunal Bhutoria, Harsh H. Vora Recycling of waste plastic had gained greater importance in today’s world. The present experimental investigation deals with the transformation of waste plastics from civic landfills to oil in a pyrolysis reactor. A single feed at rate of 8kg yielded 675ml of pyrolytic oil. The physio-chemical properties of plastic oil was found to be within ASTM standards with higher kinematic viscosity and carbon residue. Straight diesel-Plastic Oil (PO) blending was carried out at 15% (diesel 85% and plastic oil 15%) and 30% (diesel 70% and plastic oil 30%) in volume ratio. Combustion analysis and performance studies was carried out at no load and full load condition in single cylinder direct injection compression ignition engine to understand the feasibility of utilizing plastic oil as substitute fuel to commercial diesel. At full load condition, in-cylinder pressure, rate of pressure rise, rate of heat release and peak pressure were higher for PO30% than straight diesel. The brake thermal efficiency for PO blends was found to be slightly higher than straight diesel with significant increase in brake specific fuel consumption. The combustion and performance characteristics of the engine was affected significantly by the physio-chemical properties of PO.
Authors:Shekhar Yadav; Santosh Kumar Verma; Shyam Krishna Nagar Abstract: Publication date: Available online 25 September 2017 Source:Alexandria Engineering Journal Author(s): Shekhar Yadav, Santosh Kumar Verma, Shyam Krishna Nagar This paper demonstrates the potency of evolution based optimization techniques in the sense of enhancing the system’s performance. Teaching Learning Based Optimization (TLBO) is a well-known evolutionary algorithm used to optimize the parameters of the PID controller so as to improve the performance of the magnetic levitation system. The TLBO search algorithm is split into two phases, the teacher phase and the learner phase. The teacher phase is comprised of having minimum performance index as compared to learner phase. The learners improve their knowledge on the basis of teacher’s performance. The parameters are tuned while minimizing the performance index of the system. The performance index incorporated in this paper is the integral time weighted square error (ITSE). The corroboration of the above technique is ended by comparing it with the conventional control techniques.
Authors:Aditya Rio; Prabowo Dong Myung Bae Jung Min Sohn Ahmad Abstract: Publication date: Available online 24 September 2017 Source:Alexandria Engineering Journal Author(s): Aditya Rio Prabowo, Dong Myung Bae, Jung Min Sohn, Ahmad Fauzan Zakki, Bo Cao, Qing Wang The occurrence of impact needs to be predicted for various cases as it mostly delivers negative to target object and environment. In marine structure, this phenomenon has distributed numerous damages to involved objects, such as can be found in tragedy of the Estonia in 1994. This disaster led to a reassessment of the safety of passenger ships in many country. During impact both of structural and material aspects contributes to responses in form of energy, force, and damage. In present work, consideration of the both aspects would be considered in preparation, analysis, and discussion, to evaluate contribution of considered aspects on failure characteristic. A target subjected to impact load in form of collision so called struck ship which had different hull configuration would be used in analysis as structural behaviour during and after hull structure of the struck ship was penetrated by the striking ship would be observed. In material level, analyses were conducted with applying different mechanical properties on the side structure. The results indicated that the tearing of inner hull was avoided due to size of double hull structure. This condition provided better safety but lower ship capacity. In other hand, strength characteristic of material was proofed dominate difference of internal energy. Finally, the influences of material strength, failure strain, and hardening parameter were evaluated and summarized.
Authors:A.M.K. El-Ghonemy Abstract: Publication date: Available online 23 September 2017 Source:Alexandria Engineering Journal Author(s): A.M.K. El-Ghonemy Multi-Stage-Flash (MSF) Distillation is a large scale sea water desalination plants that are widely used in Gulf area. Most installations of MSF plants are operated in cogeneration with a power plant. Also, MSF plants can be combined with other desalination technologies such as Nano filtration and Reverse osmosis (RO) in new installation. However, the new MSF plants are recommended, where large amounts of cheap or waste energy are available (e.g. conventional power plants). Also, the plant location is playing an important role for economic operation due to cold or hot weather conditions. The present study is applied on the seawater multi-stage flash (MSF) desalination plant that is currently under operation in Al-Khafji operations plant located in Saudi Arabia (KSA). The plant contains 20 evaporator stages at capacity of 600,000 gallon per day (GPD). The presented operating data has been collected during a visit of the plant. Theobjectiveis to presentfieldresults of this MSF plant operation in order to measure and evaluate the performance at 70% and 100% capacity during summer (case-1) and winter (case-2) operation. Then, the plant overall performance indicators are presented to compare between the studied two cases in terms of specific cooling water flowrates and performance ratio. Finally, the seasonal performance variation of the plant is included. The results showed that, for the same plant output, the main cooling water flow rates is decreased from 47.1% to 20.1% for case-1 and case-2 respectively, which in turns directly reduces the pumping power by the same ratio. Consequently, running the large scale thermal desalination MSF plant in cold regions is more economic than hot regions for pumping power energy saving considerations. This is to be considered in future large scale desalination plants.
Authors:P. Deivajothi; V. Manieniyan; S. Sivaprakasam Abstract: Publication date: Available online 23 September 2017 Source:Alexandria Engineering Journal Author(s): P. Deivajothi, V. Manieniyan, S. Sivaprakasam The major diesel consumption is in the field of automobile, industry and agriculture. The increasing the petroleum cost also increasing the other consumable cost, it affects the economics of growing country like India. Biodiesel is considered asa promising alternative to fossil fuels worldwide. The oils selected for the study are groundnut acid oil from vegetable oil refinery industrial waste. The oil is converted into their ethyl esters by the transesterification process. Ethyl Esters of Ground Nut Acid Oil (EEGAO) and their blends (B20EEGAO, B40 EEGAO, B60EEGAO and B80EEGAO) each with diesel have been evaluated in the present investigation for single cylinder DI diesel engine. The speed of the test engine was maintained at 1500rpm in entire experiment and speed to be controlled by governor is used to control. The results obtained performance parameters slightly reduce when the engine operated with all EEGAO blend. B20EEGAO blends reduce the emission compare to all other blends and diesel.
Authors:C. Sulochana; G.P. Ashwinkumar; N. Sandeep Abstract: Publication date: Available online 19 September 2017 Source:Alexandria Engineering Journal Author(s): C. Sulochana, G.P. Ashwinkumar, N. Sandeep The boundary layer analysis of a 2D forced convection flow along a persistent moving horizontal needle in electrically conducting magnetohydrodynamic dissipative ferrofluid is investigated. The energy equation is constructed with the Joule heating, variable heat source/sink and dissipation effects. To check the variation in the boundary layer behaviour, we considered the two ferrofluids namely, Fe3O4-methanol and Fe3O4-water. The reduced system of governing PDEs are solved by employing the R-K process. Computational results of the flow and energy transport are interpreted with the assistance of tabular and graphical illustrations. Increasing the needle size significantly reduces the flow and thermal fields of both nanofluids. In particular, thermal and velocity fields of Fe3O4-methanol nanofluid is highly depreciated when equated with the Fe3O4-water nanofluid.
Authors:Mohamed Reyad; Mohamed Elkholy; Farouk El-Fitiany Abstract: Publication date: Available online 18 September 2017 Source:Alexandria Engineering Journal Author(s): Mohamed Reyad, Mohamed Elkholy, Farouk El-Fitiany Egypt is facing an increasing problem of water deficit for irrigation and other uses. Most of the Egyptian distributary irrigation canals are operated using the rotational system where water is discharged continuously during irrigation period. However, farmers rarely irrigate during night hours and a significant amount of water is lost to drains. A strategy to reduce these water losses may be adopted by suggesting better operational abstraction patterns from off-takes that are distributed along the canal and by changing the tail-escape weir heights. An unsteady-flow model is developed to study the effects of different canal parameters: weir height, canal length and slope and off-takes abstraction time on the amount of water losses. It is found that water losses are significantly affected by the weir height and the abstraction time at the off-takes. Longer and milder canals provide more storage thus reducing water losses. Adequacy indicator for water supply considerably improves for longer abstraction time. A non-prismatic and deteriorated canal is investigated and results shows that deterioration of the canal cross-sections creates an additional storage and reduces water losses. However, deterioration has negative side effects in reducing canal conveyance and lowering water levels.
Authors:E.-S. Zanoun Abstract: Publication date: Available online 18 September 2017 Source:Alexandria Engineering Journal Author(s): E.-S. Zanoun A numerical and experimental study was conducted to characterize flow through low-speed wind tunnel contractions. The simulations were carried out using an incompressible, two-dimensional flow solver based on finite volume scheme, predicting flow along the core, and at immediate vicinity of the wall of three pre-selected wall-shape contractions. The numerical results have been validated against experimental data obtained, utilizing laser-Doppler anemometer (LDA). Particular attentions have been given to the bulk flow velocity, the centerline mean velocity, the centerline velocity fluctuations, the uniformity of the mean velocity distribution at contraction’s exit, and to the mean pressure coefficient. The experimentally determined mean-pressure coefficient values along the centerline and at contraction exit were found to be similar to those predicted numerically. The fifth-order polynomial contraction showed, however, good flow characteristics at the exit plane with small non-uniformity when compared to both the two-cubic arcs and the Witoszynski second-order polynomial contractions. It was therefore adopted for the Cottbus Large pipe (CoLaPipe) facility at the Department of Aerodynamics and Fluid Mechanics (LAS), BTU-Cottbus-Sefftenberg.
Authors:Basant K. Jha; Bello J. Gwandu Abstract: Publication date: Available online 18 September 2017 Source:Alexandria Engineering Journal Author(s): Basant K. Jha, Bello J. Gwandu This work treats convective heat transfer, for an incompressible electrically-conducting fluid, moving vertically through an isothermally heated parallel plate micro-channel, within a transverse magnetic field. One surface exhibited super-hydrophobic slip and temperature jump, while the other did not. The study aimed at discovering the possible effects of magnetism on the velocity, volume flow rate and Nusselt Number when either wall is heated by constant wall temperature. It was noted that it reduces velocity and flow rate in both cases. It, also, leads to decline in Nusselt Number when the super-hydrophobic side is heated, while heating the other plate showed a negligible magnetic effect, for low temperature jump coefficients. At the critical value of the temperature jump coefficient, γ , the flow rates in both cases are equal. Before the critical value ( γ crit . ) is reached, heating the super-hydrophobic plate yields higher flow rate. After passing it, the reverse is the case. The effect of magnetism on γ crit . was, also, negative. The study will have applications in the design and maintenance of both mini- and micro-devices as well as in nano-science and nano-technology.
Authors:Engy Farrag Abstract: Publication date: Available online 14 September 2017 Source:Alexandria Engineering Journal Author(s): Engy Farrag Islam is the fastest growing religion in the world. The Muslim population increases as Islam spreads around the world, which leads to an increasing demand for Islamic buildings such as mosques and Islamic centres. Mosques play an important role in Islam and Muslim life. In several countries, in particular, the Western mosques are seen asa newcomer whose building type is both unique and foreign to local people who are unaccustomed to the visual expression of Islam in the West. The mosque is one of the most visual expressions of global Muslim religious identity in non-Muslim context. The significant numbers of countries have a lot of different architecture styles of their Islamic buildings. Each mosque has its own individual touch. The most important factors behind this variation in form and styles can be divided into nature impacts as (local materials and environment), followed by man-made impacts by (Muslim immigrants, colonialism, funding, and laws, culture, and traditions). The study aims to examine each factor and their influences on the architecture of mosques and Islamic centers in non-Muslim context through analysis and a comparison of a number of examples.
Authors:Nehad Ali Shah; Azhar Ali Zafar; Constantin Fetecau Abstract: Publication date: Available online 14 September 2017 Source:Alexandria Engineering Journal Author(s): Nehad Ali Shah, Azhar Ali Zafar, Constantin Fetecau Free convection flow of a fractional viscous fluid over an infinite vertical plate with exponential heating is studied using a fractional derivative with non-singular kernel. Fluid motion is induced by the plate that applies an arbitrary time-dependent shear stress to the fluid. Closed-form solutions for the dimensionless velocity and temperature fields and Nusselt number are established under the usual Boussinesq approximation. The obtained results can generate exact solutions for any motion with technical relevance of this type. Moreover, fluid’s velocity is presented as a sum of its mechanical and thermal components. A semi analytical solution based on the Stehfest’s formula for the inverse Laplace transform is also obtained. Finally, the influence of fractional parameter on the fluid motion as well as the contributions of mechanical and thermal components of velocity are graphically underlined and discussed.
Authors:I.L. Animasaun; I. Pop Abstract: Publication date: Available online 14 September 2017 Source:Alexandria Engineering Journal Author(s): I.L. Animasaun, I. Pop Geometrically, the upper pointed surface of an aircraft and bonnet of a car are examples of upper horizontal surfaces of a paraboloid of revolution (uhspr). The motion of these objects strongly depends on the boundary layer that is formed within the immediate space on it. However, each of these surfaces is neither a horizontal/vertical nor cone/wedge and neither a cone nor a wedge. This article presents the motion of 2-dimensional Blasius flow of Carreau fluid on the surface of such object. The case in which the reaction between the Carreau fluid and catalyst at the surface produces significant temperature differences which consequently set up buoyancy-driven flows within the boundary layer is investigated. Single first-order Arrhenius kinetics is adopted to model the reaction on the surface of the catalyst situated on uhspr which initiates the free convection. Suitable similarity variables are applied to non-dimensionalized, parameterized and reduce the governing partial differential equations to a coupled ordinary differential equations (BVP). The BVP is solved numerically using the shooting technique. Temperature distribution in the flow of viscoelastic Carreau fluid is greater than that of a Newtonian fluid. Local heat transfer rate decreases faster when the Carreau fluid is characterized as shear-thinning. Maximum concentration is guaranteed at a small value of power-law index n and large value of thickness parameter.
Authors:Muhammad Rahman; Helge I. Andersson Abstract: Publication date: Available online 14 September 2017 Source:Alexandria Engineering Journal Author(s): Muhammad Rahman, Helge I. Andersson The three-dimensional revolving flow of a particle-fluid suspension above a plane surface is considered. The flow represents an extension of the classical Bödewadt flow to a two-fluid problem. The governing equations for the two phases are coupled through an interaction force with the particle relaxation time τ as a free parameter. By means of a similarity transformation, the coupled set of non-linear ODEs becomes a two-point boundary value problem. The numerical results show that the radial inward particle velocity increases whereas the circumferential velocity decreases by shortening τ , thereby strengthening the spiralling particle motion. These predictions are consistent with the so-called tea-cup effect, i.e. accumulation of tea leaves at the centre of the cup. On the contrary, the revolving fluid motion is reduced as a result of the particle-fluid interactions.
Authors:Prem Kumar Chaurasiya; Siraj Ahmed; Vilas Warudkar Abstract: Publication date: Available online 13 September 2017 Source:Alexandria Engineering Journal Author(s): Prem Kumar Chaurasiya, Siraj Ahmed, Vilas Warudkar The effectiveness of nine different numerical methods is examined for calculating the parameters of Weibull distribution at three different heights 80m, 100m and 120m to estimate wind power density. The measurement campaign was conducted at Kayathar, Tamil Nadu, India. The time series wind data were recorded using SecondWind Triton SODAR (Sound Detection and Ranging) instrument. Firstly, the fidelity assessment of SODAR measurement was examined. The aim of this study is to identify the more accurate method for computing wind power density of a selected region. The performance of the selected methods is judged based on goodness of fit test i.e. Root Mean Square Error Test (RMSE), Coefficient of Determination (R2), Mean Absolute Percentage Error (MAPE), and Chi-square Test (X2). Wind power densities are estimated with the help of estimated parameter values. This study proposes an approach to utilize SODAR and also aims to examine the accuracy of SODAR measurement by comparing the results with cup anemometer, in an attempt to establish adequate criteria for an effective utilization of SODAR for wind resource assessment. The results suggest that SODAR may be used asan alternative to meteorological mast.
Authors:Dina A. Emarah; Safwat A. Seleem Abstract: Publication date: Available online 12 September 2017 Source:Alexandria Engineering Journal Author(s): Dina A. Emarah, Safwat A. Seleem The cyclic heave and settlement of expansive soils could be the main reason to considerable damages to the structures, roads and highways. In Egypt there are many regions containing such expansive soils especially at the desert lands. The remote areas are used now for establishing many projects such as (wind farms, solar plants, irrigation projects and nuclear power plants). The use of a mixture of lime-treated swelling soil mixed with potable water to overcome the swelling potential of these soils is available in many countries especially in U.S.A. For the projects located adjacent to the coasts of Sea, the sea water is available instead of potable water. This paper presents an experimental and field case study on the lime-treated soil but mixed with sea water instead of potable water. The effect of using sea water instead of potable water on the swelling behavior, engineering properties, and the consolidation parameters were studied. On the other hand, this research deals with the behavior of the lime-treated soil in swelling state as well as in consolidation state. Tests results showed that there are significant reductions in the swelling potential, engineering properties, and the consolidation parameters in case of using sea water instead of potable water as mixing water. The environmental and economic impact gained from such process was put into consideration.
Authors:Deepanshu Kaushal; T. Shanmuganantham Abstract: Publication date: Available online 12 September 2017 Source:Alexandria Engineering Journal Author(s): Deepanshu Kaushal, T. Shanmuganantham The improvement in the performance of a novel microstrip patch antenna through added stages of a fractal geometry and a circular split ring resonator for multiband operation is presented. In its first stage, a coaxial-fed novel shaped patch is developed over a 60mm×60mm×1.6mmFR4 epoxy substrate. The modification of the basic patch structure into a fractal geometry results into the addition of bands along with the parametric enhancement of reflection coefficient, gain and bandwidth. A further stamping of Circular Split Ring Resonator on reverse side of the substrate would result in significantly improved performance. The validation of the simulated results has been done and the measured set of data has been plotted against the simulated results graphically.
Authors:Mahrous Ahmed; Ahmed Sheir; Mohamed Orabi Abstract: Publication date: Available online 12 September 2017 Source:Alexandria Engineering Journal Author(s): Mahrous Ahmed, Ahmed Sheir, Mohamed Orabi In this paper, New asymmetric cascaded half H bridge multilevel inverter MLI is proposed. It is driven from the conventional asymmetric cascaded half H Bridge multilevel inverter. Thus, the proposed topology inherits its simplicity, flexibility and modularity in both construction and control. By proper choice of the input DC sources values and interconnection, proposed topology can eliminate the need for polarity generation circuit which normally associated with the cascaded half H-bridge. Therefore, reduces number of switches that require high blocking voltage. The selective harmonic elimination SHE method is applied to generate switching pattern to eliminate harmonics inherently associated with MLI. The proposed topology switching pattern naturally reduces component’s voltage stress, switching losses and finally decrees MLI size and cost. Mathematical expressions and analysis have been driven as well as comparison with other topologies. The validity of the proposed topology is verified with Matlab/Simulink model and then a prototype is built and experimental results are presented.
Authors:M. El-Adawy; M.R. Heikal; A. Rashid A. Aziz; M.I. Siddiqui; Hasanain A. Abdul Wahhab Abstract: Publication date: Available online 12 September 2017 Source:Alexandria Engineering Journal Author(s): M. El-Adawy, M.R. Heikal, A. Rashid A. Aziz, M.I. Siddiqui, Hasanain A. Abdul Wahhab In-cylinder air flow structures are known to strongly impact on the performance and combustion of internal combustion engines (ICE). Therefore the aim of this paper is to experimentally study an IC engine in-cylinder flow under steady-state conditions. Different methods can be used to characterize the in-cylinder flow which are optical engines and laser diagnostics, computational fluid dynamic and steady-state flow bench. Here we are concentrating on two different types of flow benches. The first (Ricardo) uses the impulse torque meter method while the other (FEV) uses the paddle wheel technique. The experiments were carried out on the same cylinder head and the same pressure difference across the inlet valves of 600mmH2O in order to compare the results. The experimental results are presented in terms of the measured air flow rate, flow coefficient, discharge coefficient and non-dimensional rig tumble. Moreover, number of modifications were conducted on the FEV flow bench in order to apply particle image velocimetry measurements on the vertical tumble plane, which passing through the middle of the cylinder at different valve lifts. The results show that a reasonably good level of agreement can be achieved between both methods, providing the methods of calculations of the various parameters are consistent.
Authors:S.R. Mishra; S. Baag; M.M. Bhatti Abstract: Publication date: Available online 5 September 2017 Source:Alexandria Engineering Journal Author(s): S.R. Mishra, S. Baag, M.M. Bhatti This communication deals with the role of heat and mass transfer in a Walters B ′ (non-Newtonian) nanofluid fluid flow through a stretching vertical porous surface. The behavior of Brownian motion, chemical reaction, thermophoresis and heat generation/absorption are also taken into consideration. A suitable similarity transformation variable is utilized to model the equations of nanoparticle concentration, momentum, and thermal energy. These ordinary differential equations are solved analytically by means of perturbation technique and then solved numerically using fourth-fifth order Runge–Kutta method. The behavior of all the sundry parameters are discussed and demonstrated via graphs. Furthermore, Sherwood number, Nusselt number and skin friction coefficient are also displayed via graphs. A numerical comparison is also presented against skin friction coefficient, Nusselt number and Sherwood number with previously published data.
Authors:A. Malvandi; F. Hedayati; D.D. Ganji Abstract: Publication date: Available online 5 September 2017 Source:Alexandria Engineering Journal Author(s): A. Malvandi, F. Hedayati, D.D. Ganji This paper studies a steady two-dimensional stagnation-point flow of nanofluids over a nonlinearly stretching/shrinking sheet in the presence of blowing/suction. The effects of different nanoparticle materials, namely copper, alumina and titania on the flow and heat transfer rate are investigated. Employing similarity variables, the governing partial differential equations including continuity, momentum and energy have been reduced to ordinary equations and are solved numerically via Runge-Kutta-Fehlberg scheme. It is shown that two solutions exist for shrinking sheets in both blowing and impermeable cases, while an additional solution appears in the case of suction (there are three solutions). Moreover, the effects of nonlinearly parameter β , blowing/suction S , and solid volume fraction ϕ on the heat and fluid flow characteristics are investigated in details.
Authors:C. Sulochana; G.P. Ashwinkumar; N. Sandeep Abstract: Publication date: Available online 5 September 2017 Source:Alexandria Engineering Journal Author(s): C. Sulochana, G.P. Ashwinkumar, N. Sandeep The present study deals with the boundary layer analysis of a 2D magnetohydrodynamic flow of chemically reacting Casson nanofluid flow over a semi-infinite inclined porous plate. The energy and diffusion equation are encompassed with frictional heating, heat generation/absorption, thermo diffusion and thermal radiation effects. For making the analysis more attractive we pondered two distinct type of nanofluids namely, TiO2-water and CuO-water. The transmuted governing PDEs are resolved analytically by employing regular perturbation method. The impact of pertinent flow parameters on momentum, thermal and mass transport behavior including the skin friction factor, thermal and mass transport rate are examined and published with the assistance of graphical and tabular forms. Results describe that thermal radiation and chemical reaction restrictions have a propensity to enhance thermal and mass transport rates, respectively. And also, water based TiO2 nanofluid possess higher velocity compared with water based CuO nanofluids.
Authors:S.C. Shiralashetti; S. Kumbinarasaiah Abstract: Publication date: Available online 5 September 2017 Source:Alexandria Engineering Journal Author(s): S.C. Shiralashetti, S. Kumbinarasaiah In this paper, new operational matrix of integration is generated by using Hermite wavelets. By aid of these matrices, Hermite wavelets operational matrix method (HWOMM) is developed for second ordered nonlinear singular initial value problems. Properties of Hermite wavelets are used to convert the differential equations into system of algebraic equations which can be efficiently solved by suitable solvers. Illustrative numerical problems are considered to demonstrate the applicability of the proposed technique and those results are comparing favourably with the exact solutions and errors.
Authors:S. Gowthaman; A.P. Sathiyagnanam Abstract: Publication date: Available online 4 September 2017 Source:Alexandria Engineering Journal Author(s): S. Gowthaman, A.P. Sathiyagnanam Homogeneous charge compression ignition engine is promising replacement for conventional CI diesel engine with lower oxides of nitrogen (NOx) and smoke emissions and improves the thermal efficiency with consume less amount of fuel. In general, HCCI engine operates with lean air/fuel charge for all operating condition, and it makes the HCCI combustion more complex and difficult to control the start of ignition point. The inlet air temperature is the primary parameter for controlling the HCCI combustion. In this study, the HCCI engine was operated at different inlet air temperatures as 90°C, 100°C, 110°C, 120°C, 130°C, 140°C and 150°C respectively. From this study, it was observed that the level of NOx emission increased with increasing the inlet air temperature and smoke emission was reduced with increasing the inlet charge temperature. The inlet air temperature about 120°C showed maximum reduction of smoke emission about 15HSU at 60% load. Similarly, CO and HC were reduced with increasing the inlet air temperature. The specific fuel consumption of HCCI mode engine decreased with increasing the inlet air temperature and the power output of the engine increased with increasing the suction air temperature.
Authors:Jacob G. Fantidis; G. Nicolaou Abstract: Publication date: Available online 4 September 2017 Source:Alexandria Engineering Journal Author(s): Jacob G. Fantidis, G. Nicolaou The optimization of a Beam Shaping Assembly design for Boron Neutron Capture Therapy (BNCT), based on a commercial available proton accelerator, has been simulated. The primary goal is to improve the flux of the epithermal neutrons, which is the major drawback in all designed BNCT facilities with portable neutron source, satisfying simultaneously all the other relevant parameters. A BNCT facility has been simulated using the MCNP4B Monte Carlo code. A wide set of material were examined as moderators, while three different materials are used as fast neutron, gamma ray and thermal neutrons filters. Fast neutrons from 9Be(p,n)9B reaction are moderated through the 7LiF and TiF3 moderators and further reduced using 60Ni as fast neutron filter. The undesired gamma rays and thermal neutrons are removed using Bi and Cd filters respectively. The therapeutic efficacy of the proposed facility was calculated through the dosimetric evaluation in a head phantom. According to the results of the calculations the proposed unit satisfies the recommended by IAEA parameters. Only the flux of the epithermal neutrons remains below the recommended threshold, but is significantly improved.
Authors:Arulprakasajothi Mahalingam; Yuvarajan Devarajan; Santhanakrishnan Radhakrishnan; Suresh Vellaiyan; Beemkumar Nagappan Abstract: Publication date: Available online 30 August 2017 Source:Alexandria Engineering Journal Author(s): Arulprakasajothi Mahalingam, Yuvarajan Devarajan, Santhanakrishnan Radhakrishnan, Suresh Vellaiyan, Beemkumar Nagappan High cetane number and energy content of octanol can be an excellent alternative fuels for existing diesel engines. It is necessary to have an extensive analysis on octanol asan additive in diesel engines. In this study neat mahua oil biodiesel is blended with different proportion of octanol in stationary diesel engine to observe its emission characteristics. Mahua oil biodiesel is prepared by conventional transesterification. The main aim of this study is to reduce various emissions of mahua oil biodiesel by appending octanol. This study discovered a significant reduction in all the emissions associated with mahua oil biodiesel by appending octanol at different proportions.
Authors:Nehal M. El Azaly; Ehab F. Badran; M.R.M. Rizk; M. Amr Mokhtar Abstract: Publication date: Available online 30 August 2017 Source:Alexandria Engineering Journal Author(s): Nehal M. El Azaly, Ehab F. Badran, M.R.M. Rizk, M. Amr Mokhtar Cognitive radio wireless networks CRNs have been considered as an efficient communication paradigm to the utilization of scarce spectrum. The main purpose of channel reservation of dynamic spectrum access (DSA) is to access these idle channels intelligently which are specialized for primary users (PUS) to be used by unlicensed users temporarily, which are called secondary users (SUS) without causing critical interference to the licensed user’s activity. In this paper, continuous-time Markov chain paradigm is improved via channel reservation to show the best usage of the radio spectrum bands, and the transition matrix are deduced for the proposed model. Moreover, the probability state vector is proved by performing steady state analysis. The deduced expressions of the suggested model are illustrated in the numerical results section.
Authors:A.KH. EL-Said; B.M. EL-Souhily; W.A. Crosby; H.A. EL-Gamal Abstract: Publication date: Available online 30 August 2017 Source:Alexandria Engineering Journal Author(s): A.KH. EL-Said, B.M. EL-Souhily, W.A. Crosby, H.A. EL-Gamal The present research work deals with studying the steady state performance and dynamic stability of sliding element hydrodynamic bearings of the three-lobe type and provided with a bushing surface textured with uniform micro protrusions. A mathematical model has been put forward for the problem using the Reynolds equation governing the unstable fluid lubrication inside the bearing as well as the equations governing the dynamic movement of the journal. The equations have been put in their numerical forms suitable for computer solution using the finite difference method. Two types of three lobe bearings have been considered, one with its plain bushing and the other with bushing textured with uniform micro protrusions. This is in addition to other two plain journal bearings one with plain bushing and the other with textured bushing. This is for the purpose of carrying out a general comparison to include the steady performance of these bearings in terms of their load carrying capacity and the friction losses in their parts in addition to their dynamic stability. It was concluded in the present work that the inclusion of these textured micro protrusions in the bushing of bearings, whether they are plain or of the three-lobe geometry improves their performance in terms of reducing their friction losses and raising their load carrying capacity along. It was found that the three-lobe bearing with protruded bushing surface texture is superior to the other types of bearings considered in the present work as far as steady state performance is concerned. Regarding the margin of stability to small sinusoidal disturbances the protruded three-lobe bearing shows a relatively lower margin. Some useful recommendations for future research work in this field of study are given in this work and the most important one is to carry out extensive experimental studies on sliding bearings surfaces fitted with textured bushings of different micro protrusions designs.
Authors:Vijaya Kumar Kareddula; Ravi Kumar Puli Abstract: Publication date: Available online 21 August 2017 Source:Alexandria Engineering Journal Author(s): Vijaya Kumar Kareddula, Ravi Kumar Puli Energy consumption is becoming the index of country development. Transportation sector is occupied the second position in total energy consumption. Traditional energy sources are obliterating out and leaving carbon foot prints on environment. Across the world plastic consumption and its disposal is increasing at exponential rate. The current research is aimed to utilize this plastic waste as an input for engine running in the form of plastic pyrolysis oil (PPO). Experiments are conducted with PPO on multi cylinder Maruti 800 petrol engine to evaluate the performance and emissions characteristics. The gasoline is blended with 15% PPO and with and without ethanol additive at 5%. The performance and emissions result of plastic oil blend is compared with pure petrol and ethanol added blend. The experimental outcomes clears, that the brake thermal efficiency of 15PPO is lower than that of pure petrol while the NOx emissions are substantially increased. Therefore, ethanol is added as an additive to control the NOx emissions, engine performance is improved compared to pure petrol and 15PPO. Emissions like CO, NOx are significantly controlled.
Authors:Ehsan Ul Haque; Aziz Ullah Awan; Nauman Raza; Muhammad Abdullah; Maqbool Ahmad Chaudhry Abstract: Publication date: Available online 20 August 2017 Source:Alexandria Engineering Journal Author(s): Ehsan Ul Haque, Aziz Ullah Awan, Nauman Raza, Muhammad Abdullah, Maqbool Ahmad Chaudhry In this paper, the velocity field and the time dependent shear stress of Maxwell fluid with Caputo fractional derivatives in an infinite long circular cylinder of radius R is discussed. The motion in the fluid is produced by the circular cylinder. The fluid is initially at rest and at time t = 0 + , cylinder begins to oscillate with the velocity fsin ω t , due to time dependent shear stress acting on the cylinder tangentially. The hybrid technique used in this paper for the solution of the problem has less computational efforts and time cost as compared to other commonly used methods. The obtained solutions are in transformed domain, which are expressed in terms of modified Bessel functions I 0 ( · ) and I 1 ( · ) . The inverse Laplace transformation has been calculated numerically by using MATLAB package. The semi analytical solutions for Maxwell fluid with fractional derivatives are reduced to the similar solutions for Newtonian and ordinary Maxwell fluids as limiting cases. In the end, numerical simulations have been performed to analyze the behavior of fractional parameter α , kinematic viscosity ν , relaxation time λ , radius of the circular cylinder R and dynamic viscosity μ on our obtained solutions of velocity field and shear stress.
Authors:A. Ibrahim; A. Dif; W. Othman Abstract: Publication date: Available online 20 August 2017 Source:Alexandria Engineering Journal Author(s): A. Ibrahim, A. Dif, W. Othman Simulating shallow grid foundation resting on a homogenous C & ϕ soil by different nonlinear finite element analysis types, and estimate the foundation geometry effects on choosing the nonlinear analysis accuracy and degree, will be the main two concerned points through this paper. Almost of the nonlinearity classified agent techniques were mentioned briefly. Through studding the interaction between foundation and soil where the expected penetration may occurs, small and large deformation analysis was performed with a good comparison between their results for various loading levels. The soil material nonlinearity was defined by hardening plasticity cap model while elasticity model was chosen for the foundation. Then the tested variables for grid foundation were performed again on a systemized rectangular raft foundation to discuss contrasts in relative stress distribution inside the soil for the two varied foundation geometries. ABAQUS cae V.6.9.1 was the F.E Program simulation.
Authors:S. Chelbi; A. Mekhmoukh Abstract: Publication date: Available online 14 August 2017 Source:Alexandria Engineering Journal Author(s): S. Chelbi, A. Mekhmoukh In many research fields, like Medical image analysis, pattern recognition, computer vision and remote sensed data processing, it is required to align the images. This article describes and compares two different methods to register images. In the first method, the Fourier Merlin transform based on the phase correlation of the two images in the Log-polar domain. However, it suffers from non-uniform sampling which makes it not suitable for applications causing losses in image information which will decrease the registration accuracy. The second method is to use the Radon transform proprieties to extract the rotation angle. Experiments show that the proposed method can detect the angle of rotation efficiently for different types of images without the SAR complex images.
Authors:Jagadeesh Varma Indukuri; Ranjith Maniyeri Abstract: Publication date: Available online 14 August 2017 Source:Alexandria Engineering Journal Author(s): Jagadeesh Varma Indukuri, Ranjith Maniyeri This paper aim to develop a two-dimensional computational model to study the fluid dynamic behaviour in a square cavity driven by an oscillating lid using staggered grid based finite volume method. Firstly the developed computational model is validated with that of other researcher’s results for the case of finite wall motion. Later the numerical simulations are performed for the case of top wall oscillations for various combinations of Reynolds number and frequencies. From these simulations an optimum frequency is chosen and then with the optimum frequency the simulations are carried out to explore the vortex behaviour for the cases of parallel wall oscillations (both top and bottom walls moving in the same direction) and anti-parallel wall oscillations (both top and bottom walls moving in the opposite direction). From these simulations it may be concluded that Re =1000 is medium range of operation for better mixing inside the cavity for the cases of parallel and anti-parallel wall oscillations.
Authors:Fekry Fares; Dina Sameh Taha; Zeyad Tarek EL Sayad Abstract: Publication date: Available online 12 August 2017 Source:Alexandria Engineering Journal Author(s): Fekry Fares, Dina Sameh Taha, Zeyad Tarek EL Sayad The responsible authorities depend on public participation in decision-making. However, there are many obstacles facing them because of their reliance on traditional tools. These obstacles include that a large number of participants do not understand the tools of participation, as well as the inconsistency of time and place in which the participation process is taking place. This creates a gap between decision-makers and participants, all of which reduce the efficiency of participation. This research paper will study the use of virtual reality, using programs such as Vizard in the conduct of a participatory process by linking virtual reality and internet without restricting the participants with a particular place and time to carry out the process of participation, as well as the provision of tools to facilitate decision-making tools. Beit Hanoun (Gaza-Palestine) was selected to test the effectiveness of the tool used because it suffers from the efficiency of the tools available to participate in the city. The results show that the tool used to effectively integrate citizens into decision-making in a more interactive way can enhance communication between decision-makers and citizens. Virtual reality tools and the Internet are reliable tools in any study of the integration of citizens into decision-making.
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