Yanbu Journal of Engineering and Science (YJES)
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COMPUTATIONAL FLUID DYNAMICS INVESTIGATION OF SOLAR ACTIVATED CARBON AIR FILTER
No full textThe solar energy is the language of this age. It is renewable, clean and almost without cost. This research is focusing on utilizing of renewable energy in air purification process. As known, our environment is full with industrial waste gases, such as SOx, NOx, COX, CH4, H2S etc. To reduce percentage concentration of these gases, solar energy is used to generate a convection stream within a metal black column. Polluted air consists of industrial waste gases, while passing through the column, it will contact with baffles of an activated carbon plates, fixed horizontally to increase the contact area with gases. The activated carbon is a common adsorbent with tremendous adsorption capability. So it will remove waste gases from polluted air. The three-dimensional steady-state continuity, Navier-Stokes, energy, radiation, natural convection, species transport for CO2 physical adsorption and multiphase Eulerian-granular model equations are solved under turbulent condition, using the commercially available Computational Fluid Dynamics software Fluent. The quality of the solutions obtained from these simulations is largely within the acceptable range proving that Computational Fluid Dynamics is an effective tool for predicting the behavior and performance of a solar air filter
A SIMULATED STUDY OF IMPACT OF ENVIRONMENTAL FACTORS ON INDOOR WORKER PERFORMANCE
No full textThe objective of the study is to explore worker effectiveness with changes in noise and temperature indoors. The experiment is carried out in the south-western part of the Kingdom of Saudi Arabia. Thirty-three Saudi young male subjects were used as sample. Three groups of 11 participants in each group were exposed to controlled environmental conditions of four different temperatures and three noise levels, and time of completion of task recorded to perform an assembly. It is found that the optimal temperature and noise level for the simulated study on the subjects is 18°C and 45 dBA respectively. The results indicate that the performance of an indoor worker in Saudi Arabia is affected by the change of temperature and noise level
INTERNAL RESONANCE FOR POWER TRANSFORMER INTERACTED WITH CABLE TRANSIENTS
No full textPower transformers may be subjected to switching surges or fault events that may be responsible for internal transformer resonance. This paper deals with two scenarios of cable-transformer resonance. The first resonance case is due to single-phase earth fault, the second resonance is due to capacitor energization. These two situations lead to excessive transient overvoltages in the secondary side of the power transformer. The effect of various factors on these transient overvoltages is studied. The study is performed on three-phase 155 MVA power transformer. Fast Fourier transform is used for analysis and defining resonance frequencies. Also, phase-plane diagram and discrete wavelet transform are used for internal resonance feature extraction. The results confirm overvoltage occurrence on the low voltage side of power transformer behind cable due to cable-transformer resonance
RAINFALL RUNOFF MODELING FOR CATCHMENTS HAVING LOW QUALITY SCARCE DATA
No full textMonthly runoff from a catchment is required for water resources engineering and management. This paper deals with runoff modeling from catchments which have scarce data of low quality. Two models namely mathematical conceptual model and Multivariate Auto Regressive Moving Average model (MARMA) were developed and applied to two catchments (Brandu River and Khost River catchments) in Pakistan. The precipitation and meteorological data used were collected from Meteorological Department Baluchistan and North West Frontier Province, Pakistan. The results of mathematical conceptual model and multivariate autoregressive moving average model were compared with each other. It was observed that multivariate autoregressive - moving average model could not provide the satisfactory results due to presence of high nonlinearity in the Rainfall-Runoff (R-R) processes of these watersheds. The performance of the conceptual model was acceptable. Keywords: Brandu River; Khost River; Autoregressive, Mathematical models; Low quality; Runoff
INFLUENCE OF THE EXPERIMENTAL CONDITIONS ON THE REMOVAL OF DYES FROM AQUEOUS SOLUTIONS USING ULTRAFILTRATION
No full textThe main aim of this paper is to investigate the ability of hollow fiber ultrafiltration membrane of MWCO of 5 KD made of polysulfone to remove reactive dyes from wastewater. Two reactive dyes, violet 5R and C.I red 222.1, were studied under different experimental conditions of flow rate, temperature, concentration, pH, and transmembrane pressure to determine the best conditions under which the highest percentage of dye removal can be achieved. Binary systems of the two dyes prepared in different ratios to study the ability of membrane to treat solutions containing dye mixtures. It was showed that 91% of violet dye removal and 88% of red dye removal were achieved when both dyes were treated individually. Flow rate and pH proved to have great effects on membrane performance in the case of violet dye whereas solution pH showed the greatest effect for red dye removal. For the binary systems, it was found that interactions between dyes are not significant. Solutions with properties similar to that of the effluents from textile industry were prepared and 6% of violet dye removal as well as 20%-80% of red dye removal were achieved. Resistance In Series model was applied to find the flux theoretically which showed agreement with experimental values
with a variable error ranging from 2-21%
Efficient Removal of Copper and Cadmium from Contaminated Soil Utilizing Electrokinetic Process
No full textPresent manuscript demonstrates the efficient removal of copper and cadmium from contaminated soil utilizing electrokinetic process. The results of systematic bench-scale study on improved extraction of copper and cadmium shows the suitability of process to decontaminate low permeable soil. The influence of operating parameters such as electrode material, soil pH, current density, soil temperature, inter-electrode spacing and initial soil moisture content on the decontamination performance is investigated. Study revealed that, removal of copper and cadmium reached to 89.4% and 62.7% respectively while using titanium electrodes. Removal efficiency improved with the increase in current density, soil temperature and initial soil moisture content. About 74.5% of copper removal achieved within 20 hours at soil temperature of 35°C and current density was kept at 9.3 mA/cm2. During this study, soil pH decreased from 6.7 to 2.4 near anode and reached up to 12.3 near cathode resulting in augmented metal removal. An improvement of 33% in removal efficiency observed when moisture content increased from 45% to 73%. Rate of metal removal increased as the inter-electrode spacing decreased to 15 cm, which demonstrated the highest copper removal at a current density of 9.3 mA/cm2. The maximum energy consumption found to be 5.2 kWh/m3 of soil volume demonstrated the economy of process, which can be scaled up at cleanup sites
VES AND GPR INVESTIGATIONS TO DELINATE BURIED OBJECTS, CAVITIES AND WEAK ZONES INSIDE AN OIL ESTABLISHMENT SOUTHERN IRAQ, WITH THE ASSISTANCE OF HYDROGEOLOGICAL AND GEOTECHNICAL INFORMATION
No full textSeven vertical electrical sounding points (Schlumberger array) and 32 profiles of ground penetration radar were chosen to completely cover the study area in an industrial establishment site located southern of Iraq Basrah City. Geotechnical and hydrogeological investigations were also carried out as additional tools to enhance the detection of water table, buried bodies, cavities and weak zones as well as the resulting channels underlying the considered site. Several pronounced anomalies noticed in resistivity and radar sections that indicate the existence and extension of the underneath cavities were presented and analyzed
Numerical Experiments and Analysis of Shock Wave Diffraction around Structures
No full textFlows with adverse pressure gradients are more challenging to simulate numerically due to the boundary layer separation. However, the computational fluid dynamics have been used successfully to improve the understanding of the complex fluid dynamics of the transient shock-induced shear layers. The present research tries to investigate the eligibility of the inviscid, viscous (laminar), and turbulent solvers to find which ones reveal realistic results and agree best with the experiments. The solvers are based on the Euler, the Navier-Stokes equations, and the Reynolds averaged Navier-Stokes equations coupled with the SST turbulence model, respectively. A mesh-adaptive high-order AUSM+ numerical scheme is applied. A systematic validation is performed with three cases focusing on the mechanism of the shock wave diffraction and the behavior of the shear layer. They are shock wave diffraction over a backward-facing step, convex 8o sharp splitter, and curved splitter. The investigation reveals that it is crucial to apply a turbulent solver for flows with separation due to the adverse pressure gradient. The lack of viscosity is responsible for the deviation of the inviscid and laminar resolutions from experiments. Moreover, the CFD simulation reveals tiny details about the shock wave diffraction around curved structure not appear in the experimental schlieren and shadowgraph
SOFT PRODUCTION OF PHY MESON IN PHOTON PROTON INTERACTION
No full textIn the present model the photoproduction of the ∅ meson cross section is calculated. The contribution from soft pomeron exchange is calculated using DL model. It is found that this model is over-estimated the data. A mass correction factor related to the masses of p and mesons is used to normalize the DL model. The hard pomeron contribution is also calculated using The pQCD model. A reasonable agreement between the model and the data is obtained.
DETERMINATION OF ELASTIC CONSTANTS OF NATURAL MICA
No full textThe laminate structure of mica is very complex, mostly due to its anisotropic behavior in the direction of the property C33. Therefore, cutting mica sample is always challenging, particularly when relatively thick samples are desired. Thinner samples are relatively easy to cut and suffer little damage. However, in thick samples much damage can occur. This damage consists of cracks and boundary debonding between mica layers causing the properties to vary as a function of thickness. Therefore, the overall objective of this research is to determine the Young\u27s modulus of natural muscovite mica using different thicknesses. Using tensile tester (Q 800 DMA), the Young\u27s modulus of muscovite mica was found to be 178.3 GPa for 20 µm thick samples. This modulus agrees well with the literatures values for mica. The modulus decreased gradually when the sample thickness increased, reaching a mean value of 115 GPa for 94 µm thick samples. This indicates a decrease of about 35% Young\u27s modulus when the thickness increased by -79%. Cutting muscovite with a specifically designed pressure fixture shows improvement in Young\u27s modulus along the direction of the property Cin, compared with the hand-cut fully exfoliated procedure. In addition, Young\u27s modulus was not improved using pressure fixture cut compared with hand-cut samples. From these results it can be concluded that, the weak bonding which hold the layers together, could carry and/or transmit loads and is a key element to the overall stiffness of mica