@article { author = {Abdel Aziz, El Sharif M. and Taha, Yehia K. and Eweada, Samy N.}, title = {THEORETICAL STUDY OF EARTH PRESSURE AT – REST FOR SANDY SOILS}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {1-13}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.112114}, abstract = {The solution of many foundations - engineering problems requires knowledge of the lateral pressure which may be exerted by the earth or surcharge loads. The lateral earth pressure is a significant design parameter in many of the foundation engineering problems subjected to lateral pressures commonly used as parts of many civil engineering projects. Some examples of these structures are, retaining walls, sheet-pile walls, both braced and unbraced excavations, trench excavations, grain pressures on silo walls, cofferdams, caissons, embedded shells and other types of underground structures requiring an estimation of the lateral pressure for design or stability analysis. The different formulae such as Jaky , Hendron , Brooker and Ireland, Vierzbiczky , Saglamer , Wenkow , Robert Szepeshazi , Matsuoka et al, Bolton , and others were used to determine the factor Ko. The main aim of this research is to estimate the coefficient of earth pressure at rest equation depending on the theoretical relationship between the active, passive earth pressures and the lateral strain of soil. The important result from this research is: The research included other important results.}, keywords = {Earth pressure,Ko,coefficient of earth pressure at rest}, url = {https://jesaun.journals.ekb.eg/article_112114.html}, eprint = {https://jesaun.journals.ekb.eg/article_112114_863f4bd02aff0cba7c93be41a48d1ee6.pdf} } @article { author = {Ahmed, Khaled I.E.}, title = {A NEW BALL SET FOR TUBE SPINNING OF THIN-WALLED TUBULAR PARTS WITH LONGITUDINAL INNER RIBS}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {15-32}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119713}, abstract = {Tube spinning is one of the old incremental forming manufacturingprocesses. Recently, tube spinning using balls as forming tools, has beenextensively utilized in producing tubular components with longitudinal orhelical internal gear teeth, internal grooves or internal ribs. Thin-walledtubular parts with longitudinal inner ribs emerge in order to adapt to thedevelopment of aeronautic, aerospace and military industry. Recentdevelopment of tube spinning of macro and micro inner grooved tubesand inner geared drums face many challenges. The most important onesare; material built up formation in front of the forming balls, materialfolding at the tube inner surface, and the forming mandrel failure due toload fluctuations at the root of the forming tooth. These problems havebeen addressed separately in the literature without a unified approach tosimultaneously overcome them. The current study proposes a new ballset design that is claimed to be able to overcome these problemssimultaneously. A finite element simulation model for the conventionaland the new proposed designs is built and verified. The conventionalball set contains four balls lie in the same plane. The proposed designcontains 24 balls distributed in four planes, having 6 balls in each plane.The first plane is set to suppress the built up formation, the second andthird plane are set for the main forming process, the fourth plane is setfor suppressing the load fluctuation. Each two consecutive planes areshifted by 60 deg from each other to suppress the folding creation. Byexamining the achieved results, the new design has shown the potentialto significantly reduce the built up formation in the front of the formingballs. Also, the reactions at the inner surface of the spun tube haveshown significant improvements in both the radial load fluctuation whichis responsible of the folding problems and the load in the tangentialdirection which is responsible of the tooth root failure.}, keywords = {Tube spinning,Ball spinning,Spinning Rollers,Finite Element,Build up formation,Folding,Inner ribs,Grooved tubes,Micro grooved fins,Internal gear forming,metal forming}, url = {https://jesaun.journals.ekb.eg/article_119713.html}, eprint = {https://jesaun.journals.ekb.eg/article_119713_f1374028378fba42bb1ed68b28a40733.pdf} } @article { author = {Hafez, Ahmed A. A.}, title = {SIMPLE DESIGN PROCEDURE FOR HIGH-POWER THREEPHASE INVERTERS OPERATING IN PWM AND SIX-STEP MODES}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {33-48}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119693}, abstract = {This paper proposes simple analytical expressions for RMS, peak, andaverage currents in three-phase DC/AC inverter operating underdifferent operating conditions. The results were validated by rigoroussimulation.}, keywords = {}, url = {https://jesaun.journals.ekb.eg/article_119693.html}, eprint = {https://jesaun.journals.ekb.eg/article_119693_53c995925045fde21551b454dbb52209.pdf} } @article { author = {Ali, Samia A. and Hussain, Khaled F. and Sayed, Ahmed M.}, title = {FAST GENERATION OF DEMOLITION SPECIAL EFFECTS ON 3D BUILDINGS}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {49-71}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119694}, abstract = {Creating natural, controllable, and efficient computer-generateddemolition effects has become a challenging goal in the area of computergraphics. Such effects are of great use in diverse areas that include videogames, computer animation, and special effects in action films.Unfortunately, creating such effects is become complicated and timeconsumingdue to the demolition's natural complex movements and itsrelated effects that include fragmentation, fog, debris, collapsed walls,and dust. To generate realistic demolition special effects, there are twowell-known approaches, manual and destruction simulations. Themanual approach relies on choosing appropriate tools and setting itsparameters to achieve the desired level of realism. However, thisapproach requires a long time and effort from the designers. On the otherhand, the destruction simulations depend on the nature of the demolishedobjects. However, this approach is slow due to the complexity ofsimulating the physical behavior of the destructed objects and the energyproduced by the collisions between them. The proposed method is basedon the automation of the manual approach which depends on creatingthe effect through programming a script, list of instructions, to generatebelievable and compelling demolition effect in a fast manner.}, keywords = {Collision Detection,Computer-generated Effects,Demolition Effect,Fast Generation,Special Effects}, url = {https://jesaun.journals.ekb.eg/article_119694.html}, eprint = {https://jesaun.journals.ekb.eg/article_119694_3c917eeda3a481d57d6b351cbe05e968.pdf} } @article { author = {Thabet, A.}, title = {ADVANCED SIMULATION MODELS FOR PREDICTING ELECTRIC RESPONSE AND AGING OF NANOCOMPOSITE INDUSTRIAL INSULATION MATERIALS}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {73-86}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119695}, abstract = {Electric response of nanocomposite industrial materials has beeninvestigated for all possible causes and effects of the interphase regionon a variety of complex composite systems by using Interphase PowerLaw IPL model. Thus, this paper investigates the effective dielectricresponse of nanocomposite industrial insulation materials and effects ofthe interphase region on a variety of complex composite systems.According to the statistical approach of failure in polymeric insulators,that leads us to predict the procedures and mechanisms of failures whichoccur within insulating materials, this paper illustrates the failurestatistics of a life model for ac electrical aging of nanocompositeinsulation industrial materials which depicts the mechanisms ofelectrical breakdown under high voltage electric fields by advancedsimulation model program. Case studies are used to illustrate the wayand mechanisms which mechanistic features which can be related to theparameters of the failure statistic. Realized lifetime of insulationmaterials can be evaluated by means of this model. Aging of polymericinsulators has been examined through various high voltage electricfields, so the possibility of predicting the lifetime of individual specimenshas been succeeded.}, keywords = {Nanocomposite,nanofillers,Life-time,Statistical,polymers,Electrical aging,Thin films}, url = {https://jesaun.journals.ekb.eg/article_119695.html}, eprint = {https://jesaun.journals.ekb.eg/article_119695_c0dd3d3e22eff2677d3eecad5ed29841.pdf} } @article { author = {Mohamed, Yehia S. and Hasaneen, B. M. and A. Elbaset, Adel and Hussein, Alaa Eldin}, title = {RECURSIVE LEAST SQUARE ALGORITHM FOR ESTIMATING PARAMETERS OF AN INDUCTION MOTOR}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {87-98}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119699}, abstract = {This paper presents a linear parameter estimation technique used toestimate the rotor resistance, self inductance of the rotor winding,stator resistance and the stator leakage inductance of an inductionmotor. Such estimation is important for achieving high estimationperformance of induction motor drives. The parameters estimationmodel expresses the relationships of the dynamic machine model interms of measurable stator voltages, currents and motor speed. Thismodel is represented by a linear regression equation from whichmachine parameters can be obtained using a recursive least squares(RLS) estimation algorithm. Simulation results are presented tovalidate the proposed estimation algorithm with reasonable accuracy ofthe estimated parameters regardless of load conditions. Comparisonsbetween experimental and calculated steady-state performances usingthe estimated parameters are also presented.}, keywords = {Parameters estimation,Induction motor,Recursive Least Squares}, url = {https://jesaun.journals.ekb.eg/article_119699.html}, eprint = {https://jesaun.journals.ekb.eg/article_119699_c9a7f7d9a81ce87c9ca047e320d2f1cb.pdf} } @article { author = {Noureldeen, Omar and Rihan, Mahmoud Sameh and Hasanin, Barakat}, title = {SUPPORT OF FSIG WIND FARM CONNECTED TO THE GRID DURING FAULTS}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {99-111}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119700}, abstract = {The penetration of wind power in electrical power system is increasedrapidly. Most conventional wind farms are based on fixed speedinduction generators FSIG. So it is very necessary and important tostudy the transient stability ofthe wind farms with FSIC. This paperinvestigates the impacts of fault occurrence on the stability of wind farminterconnected grid. The behavior of the wind farm during different faulttypes such as single phase to ground fault, double phase to ground faultand three phase to ground fault is studied. Also, the impacts of reactivepower compensator during steady state and fault state conditions arestudied. A simulation model of wind farm based on FSIG interconnectedgrid and equipped with static synchronous compensator STATCOM aredeveloped by MATLAB-SIMULINK toolbox.}, keywords = {wind power,FSIG,Fault Types,Wind Farm Protection,STATCOM}, url = {https://jesaun.journals.ekb.eg/article_119700.html}, eprint = {https://jesaun.journals.ekb.eg/article_119700_39459239496a719ca2a4b8a91548fcfe.pdf} } @article { author = {Ahmed, A. and Amer, O. Z. and Mobarak, Y. A.}, title = {POWER SYSTEM DAMPING ENHANCEMENT VIA COORDINATED DESIGN OF PSS & TCSC}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {113-122}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119702}, abstract = {The main objective of this paper is to investigate the enhancement ofpower system stability via coordinated design of Thyristor ControlledSeries Compensation (TCSC) and Power System Stabilizers (PSSs) inmulti-machine power system. The problems that are to be faced in theplanning stage are appropriate type, location, size and setting of thesecontrollers for various applications. In order to address this problem, aneffort is made in this project to study technical issues of TCSC controllerin type, capacity and placement, and other pertinent information relatingto power system in developing nations.}, keywords = {FACTS,TCSC,PSS,multi-band,Delta-Pa,Delta-w,Multi-Machine Power System}, url = {https://jesaun.journals.ekb.eg/article_119702.html}, eprint = {https://jesaun.journals.ekb.eg/article_119702_7ff030a2f9ebd1db8d72a984a6144298.pdf} } @article { author = {Sayed Mohammed, Usama}, title = {A PIXEL-DOMAIN POST-PROCESSING TECHNIQUE TO REDUCE THE BLOCKING ARTIFACTS IN TRANSFORM CODED IMAGES}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {123-133}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119705}, abstract = {The reconstructed images after compression produce annoying blockingartifacts near block boundaries, particularly in a low bit-rate imagecompression, because each block is transformed and quantizedindependently. Detection of blocking artifact has an important role in thedesign of image coding systems. Increasing the bit rate to obtain betterquality images is too costly. In this paper, a novel pixel-domaintechnique for image blocking artifact detection is presented. Thealgorithm detects the regions of the image which present visible blockingartifacts. The blocking artifact detection and reduction are presented asa post- processing in the image decoder. The algorithm first detects thedirection of the artifact through power spectrum estimation of the pixelabsolute difference (PAD) in both horizontal and vertical directions. Thepower spectrum of the PAD is estimated using the Maximum Entropymethod (MEM) which is a nonparametric method to perform accuratepower spectrum estimation. The reduction process is applied only on thedirection of artifacts to improve the image quality. The key of thereduction process is based on the modified-projection operator to givereasonable modifications for the block boundary pixels. The simulationresults illustrate the performance of the proposed method for the JPEGdecoded images.}, keywords = {Blocking Artifacts,compressed image,power spectrum estimation,post-processing,JPEG,Image processing}, url = {https://jesaun.journals.ekb.eg/article_119705.html}, eprint = {https://jesaun.journals.ekb.eg/article_119705_523f460e97b8705b4bc719b60c8debf4.pdf} } @article { author = {Sayed Mohammed, Usama}, title = {HIGH PERFORMANCE VIDEO CODING TECHNIQUE BASED ON HYBRID TRANSFORMATION}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {135-143}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119706}, abstract = {This paper describes a computationally efficient hybrid video codingscheme. The proposed hybrid coding scheme combines the advantages ofsimple hardware complexity of the 3-D discrete cosine transform codingand the high performance of the 3-D set partitioning in hierarchical tree(3-D SPIHT) coding. The modification of the subband video data in thewavelet domain is done based on the DCT transformation and theclassification of the coefficient in the low-frequency video subband (LL).The modification process provides a new subband video data containingalmost the same information of the original one but having smallervalues of the wavelet coefficient. Simulation results of the proposedmethod demonstrate that, with a small addition in the computationalcomplexity of the coding process, the PSNR performance of the proposedalgorithm is much higher than that of the 3-D SPIHT test coder.}, keywords = {}, url = {https://jesaun.journals.ekb.eg/article_119706.html}, eprint = {https://jesaun.journals.ekb.eg/article_119706_e9a959ea7cec198f40140c475fc82355.pdf} } @article { author = {Noureldeen, Omar and Rihan, Mahmoud and Hasanin, Barakat}, title = {IMPACT OF FAULT LOCATION AND DURATION ON THE STABILITY OF WIND FARM INTERCONNECTED GRID}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {145-160}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119707}, abstract = {This paper investigates the impacts of the fault ride through on thestability of fixed speed wind farm interconnected grid. The effect of faultlocation and its duration time are studied for different fault types. Thecontribution of Static Synchronous Compensator STATCOM to supportthe fixed-speed wind farm interconnected electric grid during differentfault locations and different fault durations are investigated. Simulationtest cases using MATLAB-Simulink are implemented on a 9 MW windfarm exports a power to 120 KV grid. The simulation results show theinfluence of fault location and its duration on the active power, reactivepower, and bus voltage of the wind farm}, keywords = {wind farm,STATCOM,fault location,Fault Duration}, url = {https://jesaun.journals.ekb.eg/article_119707.html}, eprint = {https://jesaun.journals.ekb.eg/article_119707_da32aafd9b548dfcb99dde352c20a318.pdf} } @article { author = {El-Sawy, A. M. and Mohamed, Y. S. and Hassan, A. A. and Shehata, E. G.}, title = {SLIDING MODE TORQUE CONTROL OF AN IPMSM AS INFLUENCED BY IRON LOSS}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {161-177}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119709}, abstract = {This paper presents a robust direct torque control of an interiorpermanent magnet synchronous motor (IPMSM) based on a sliding modecontroller. The sliding mode control (SMC) law is designed in such away that the chattering effect is reduced and the problem of reachingphase stability is eliminated. A space vector modulation is combined withthe SMC to ensure minimum ripple content and high resolution voltagecontrol. To demonstrate the validity of the proposed scheme, thecalculated motor speed, estimated motor torque, stator flux and statorcurrent in the presence of iron losses are compared with those measuredin the literature. It is concluded that consideration of iron losses in thedynamic model of the machine improves the theoretical predictions andreduces the discrepancies between the calculated and measured values.}, keywords = {Dynamic model of an IPMSM taking iron losses into account,Direct torque control,Sliding Mode Control,Space vector modulation}, url = {https://jesaun.journals.ekb.eg/article_119709.html}, eprint = {https://jesaun.journals.ekb.eg/article_119709_060a32afc890d8ccd8839af32868b6b2.pdf} } @article { author = {Hassan, A. A. and El-Sawy, A. M. and Mohamed, Y. S. and Shehata, E. G.}, title = {SPEED SENSORLESS CONTROL OF AN IPMSM DRIVE BASED ON ACTIVE FLUX CONCEPT}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {179-194}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119711}, abstract = {This paper investigates a novel direct torque control (DTC) for asensorless interior permanent magnet synchronous motor (PMSM) basedon a sliding mode technique (SMC). The speed and position of theinterior PMSM are estimated online based on active flux concept. Toovercome the large ripple content associated with the direct torque, atorque/flux sliding mode controller has been employed. Two integralsurface functions are used to construct the sliding mode controller(SMC). The command voltage is estimated from the torque and fluxerrors based on the two switching functions. The idea of total slidingmode is used to eliminate the problem of reaching phase stability. Thespace vector modulation (SVM) is combined with the sliding modecontroller to ensure minimum torque and flux ripples and provides highresolution voltage control. The proposed scheme has the advantages ofsimple implementation, and does not require an external signal injection.In addition, it combines the merits of the direct torque control, slidingmode controller, and space vector modulation beside the sensorlesscontrol.Simulation works are carried out to demonstrate the ability of theproposed scheme at different operating conditions. The results confirmthe high performance of the proposed scheme at standstill, low and highspeeds including load disturbances and parameters variation.}, keywords = {Active flux concept,Speed sensorless control,Direct torque control,Sliding Mode Control,Space vector modulation}, url = {https://jesaun.journals.ekb.eg/article_119711.html}, eprint = {https://jesaun.journals.ekb.eg/article_119711_d08a4773726dc62c2168a95d6b39f106.pdf} } @article { author = {Mageed, A.A. and Rizk, SH.A. and Abu-Ali, M.H.}, title = {UTILIZATION OF WATER TREATMENT PLANTS SLUDGE ASH IN BRICK MAKING}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {195-206}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119717}, abstract = {The present study investigates the possibility of using water treatmentplant (WTP) sludge of New Assiut city (Assiut- Egypt) as partialsubstitute for shale in brick making. Due to the high content of organicmatter in water sludge, incineration of the WTP sludge is necessary toremove of all organic compounds contained therein. For brick making,mixture of various proportions from 10 % to 50% by weight of sludgeash added to shale are used as raw materials in hand molding brickmaking. The produced brick samples after drying process and firing at1000 0C for 6 hr,,s , received a series of tests including firing shrinkage ,weight loss on ignition water, absorption ,bulk density ,compressivestrength , slake durability and efflorescence test. Satisfactory resultswere achieved when the percentage of sludge ash was up to 30% (by wt.)or less in the mixture. The specifications of the produced bricks matchthe Egyptian standard ES: 1756/1989 of fired clay building units for nonload bearing walls. The test results indicate that, the sludge ashproportions are one of the most important key factors determining thebrick quality. Reuse of sludge ash as a construction and buildingmaterial converts the waste into useful products that can alleviate thedisposal and environmental problems.}, keywords = {Water treatment plant sludge,Clay bricks,Waste Recycling}, url = {https://jesaun.journals.ekb.eg/article_119717.html}, eprint = {https://jesaun.journals.ekb.eg/article_119717_f12a2a6764c6d6fd150d788ed84ad6a2.pdf} } @article { author = {AHMED, A. A. and ABOUZEID, A - Z. M.}, title = {AN ENVIRONMENTAL SOLUTION FOR PHOSPHATE COARSE WASTE REJECT-USING THEM AS CONCRETE MIX AGGREGATES}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {207-218}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119718}, abstract = {Large quantities of coarse solid wastes are generated during thebeneficiation of Egyptian phosphate ores. The volume of the solid wastegenerated and accumulated from the mineral processing activities, isthe main pollution concern in the mining area around the plant.However, these wastes, because of their similarity to conventionalaggregates, represent a potentially useful source of material for avariety of applications.This paper examines the suitability of the coarse solid wastes generatedfrom upgrading phosphate ores as aggregates in concrete mix. Theproperties of these wastes are tested, according to the EgyptianStandard Test Methods for Concrete Mix (ESTMCM). According to theresults obtained, the mean value of uniaxial compressive strength ofstandard concrete cubes tested after 28 days of curing was found to bein the average 240 kg/cm2 (ESTMCM ranges between 180 – 300kg/cm2). The obtained results proved that this kind of wastes can beused for concrete mix in civil constructions. The positive uses of thesewastes are considered beneficial from the economic and environmentalpoints of view.}, keywords = {Phosphate waste utilization,Concrete mix,Aggregates for civil constructions,Environmental cleaning,ESTMCM}, url = {https://jesaun.journals.ekb.eg/article_119718.html}, eprint = {https://jesaun.journals.ekb.eg/article_119718_396cd59e92be2e4280bfc3bdabca1a6c.pdf} } @article { author = {Farag, M.Z. and Abdel-Khalek, N.A. and Hassan, M.S. and El Areef, M.M. and El Manawi, A.W.}, title = {CHARACTERIZATION AND GRAVITY SEPARATION OF NONSULFIDE ZINC DEPOSITS FROM UM GHEIG MINE, RED SEA COAST, EGYPT}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {219-231}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119720}, abstract = {This paper aims to beneficiation of Um Gheig nonsulfide Zinc ore fromits associated gangues using the gravity separation “shaking table”technique. The different operating parameters affecting of the efficiencyof the separation process is evaluated.The zinc locality of Um Gheig represents one of the important nonsulfidezinc deposits along the coastal plain of the Red Sea Coast, Egypt. Thesezinc ores are called “calamines” and consist mainly of a mixture of zinccarbonates (smithsonite, hydrozincite) and zinc silicates (hemimorphite),with a variable content of calcite, goethite and Pb bearing minerals.Extensive mineralogical (using XRD, XRF) and petrographic studieshave been carried out on the selected samples from Um Gheig Mine.Theses investigations show that, the nonsulfides mineral association inthe deposit consists mainly of smithsonite (50.74%), hydrozincite(18.78%) and hemimorphite (14.78%) replacing both primary oreminerals and carbonate host rocks. Smithsonite occurs in twogenerations, cryptocrystalline mixed with goethite and rhombohedralcrystals, precipitate in vugs and open space of the high grade ore. Themain gangue minerals are calcite and goethite. XRF analysis indicatesthat the sample contains 47.50% ZnO, 1.55% PbO and about 29.28%L.O.I.Liberation and mineralogical investigation showed that higher degree ofliberation (over 90%) between the valuable zinc bearing minerals andtheir gangues can be achieved below the size 0.106 mm.The results of gravity separation showed that the best operatingparameters to obtain a concentrate with high assay and recovery are atinclination angle (4 degree), stroke length (2.5 cm), feed rate (150 gm /min), and water flow rate (25 l / min). At these optimum conditions aconcentrate assaying 60.85 % ZnO was obtained with a recovery of~90 %.}, keywords = {Nonsulfide zinc ore,Mineralogy,Petrography,Liberation size,Gravity separation,Shaking Table}, url = {https://jesaun.journals.ekb.eg/article_119720.html}, eprint = {https://jesaun.journals.ekb.eg/article_119720_b0a854a7cde6e660698547b3692fa9cc.pdf} } @article { author = {Othman, Fatma Othman Mohamed}, title = {VISUAL EXPERIENCE (VISUAL SEQUENCES) OF QAIETBAI CASTLE IN ALEXANDRIA IN THE NATURAL AND BUILT CONTEXT}, journal = {JES. Journal of Engineering Sciences}, volume = {39}, number = {No 1}, pages = {233-248}, year = {2011}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2011.119721}, abstract = {Qaietbai Castle in Alexandria is one of the most important Islamicmonuments that possesses a unique position according to the city شs builtcontext as it gathers between the natural component that are representedin the heaven space and aqua surface, as well as its other activities onthe hand, and the built context represented in the surrounding urbanizedareas with their visual components on the other.This paper aims at studying the possibility of upgrading aesthetic imagelevel , and achieving a higher positive level of visual realization ofhistorical places as well as investing this in urbanized built upgrading ofvaluable historical building ,and other surrounding areas throughreaching ordered systematic steps that enable us to achieve a higherlevel of visual realization of heritage building through its visual richnessand surrounding areas , and prevent confusion that contributes toreducing visual realization .This study depended on descriptive and analytical approach throughstudying the most important elements that affect visual richness andrealization of historical places, through describing and analyzing thecase study of Qaietbai Castle in Alexandria to specify the problems facedby valuable monumental placesSo the study was conducted to investigate the visual experience to realizethe castle on the way to the beach of Alexandria city through dividing itinto sectors of sight to study the visual sequence towards the castle , thepossibility of its visual richness , and the visual experience inside thecastle , its neighborhoods and the surrounding urbanized environment .The study showed the importance of visual studies in Egyptian cities ,enriching urban and archeological areas , and not neglecting orconsidering them secondary things especially in the archeologicalregions , and taking serious steps to prevent visual aggressiveness in allits kinds to create interaction between the receiver and the visualenvironment of heritage zone that should be in the mind of the visitor asan unforgettable visual experience . As for the city inhabitant, hisinteraction with the visual environment in his city does strengthen hisbelonging to the city, and encourages him to converse its heritage zones.They are all positive values we wish to enhance, converse, andstrengthen.The research consists of four parts , the first part deals with the problemof research and its methods, the second part is a theatrical introduction  to visual realization of heritage and historical areas in the built contextand environmental surroundings , as well as the most important meansthat leads to visual richness of such areas . the third part deals with astudy of the visual experience to realize the building of Qaietbai Castle ,the possibility of its visual richness and giving the surrounding area aunique visual character due to the visual reference represented in thebuilding of the castle . The fourth part deals with the concluded results.}, keywords = {}, url = {https://jesaun.journals.ekb.eg/article_119721.html}, eprint = {https://jesaun.journals.ekb.eg/article_119721_c5f887acd9a54031aafe65f6992cd355.pdf} }