bluuebunny/crossref_metadata_2025 huggingface dataset:
ANALISIS KELAYAKAN INVESTASI ALAT ROLL STREAPING PADA UKM MEKAR HANDCRAFT
Authors: Zaini Ahmad
Published: March 2024

UKM "Mekar Handcraft" produces woven bags. The initial process involves cutting the strings using a manual tool made of wooden blocks with nails. Then, a rolling streaping tool is used, but it faces a constraint where some raw materials cannot be spun using the spinning tool, so a manual tool is used instead. Additionally, the proximity of the raw material to the roll area is too close, resulting in frequent string breakage. The introduction of this new streaping tool innovation is expected to accelerate the production process. An investment feasibility analysis is needed to determine the viability of this investment. Based on the research, the Net Present Value (NPV) is calculated to be (Rp.212,450), which is greater than 0, indicating that the investment is viable. However, the Internal Rate of Return (IRR) calculation yields a value of 11.29%, which is less than the Minimum Acceptable Attractive Rate (MAAR) of 20%, indicating that the investment is not viable. The Payback Period calculation results in 10.78 months, indicating a relatively fast return on investment, making it a viable investment. Furthermore, the Profitability Index (PI) calculation yields a value of 1.11, which is greater than 1, indicating that the investment is viable
THE EFFECT OF TRELLIS TERMINATION ON THE PERFORMANCE OF TURBO CODE
Authors: Abbas H.H. , Mahmoud W. A. , Omran S.K.
Published: March 2024

This paper introduces a new class of convolutional codes, which is called Turbo Code. Turbo Code was shown to achieve performance in terms of Bit-Error-Rate (BER), which is near Shannon limit. Turbo Code encoder is built using a parallel concatenation of two Recursive Systematic Convolutional (RSC) codes. In this paper, two solutions to the trellis termination problem are presented. The first solution encoder uses terminated Upper RSC encoder and unterminated Lower RSC encoder. On the other side, the second solution encoder uses terminated Upper and Lower RSC encoders. The performance of the two solutions is tested for different circumstances and the results are interesting.
ERFORMANCE OF DIFFERENT PACKING CONFIGURATION IN A COOLING TOWER
Authors: Sulaymon Abbas H. , Omran Hamied Ali , Al-Fatlawy Nagam O.
Published: March 2024

This research is concerned with performance of different shapes (parallel plate, grid, corrugated) and materials (polystyrene, polypropylene, P.V.C, and steel) of packing for an air -water- cooling tower. A Mechanical forced draught counter current flow cooling tower of 300 mm x 300 mm, cross-sectional area and 1.65m height was constructed and studied theoretically and experimentally Air flow rates of 0.533,1.035, and 1.774 kg/m2.s were used in conjunction with water flow rates of 1.686, 2.218, and 2.66 kg/m2.s, and water temperature of 40,45,50 °C. The tower characteristics (KG a Z/L) and the volumetric mass and heat transfer coefficients (Kça, hoa and ha) are found to be a function of the water and air flow rates simultaneously.The work was extended to include the longitudinal and transverse temperature profiles within the tower for different parameters.By employing packed heights of polystyrene, and polypropylene of 120,90,60, and 30 cm, end effect were studied and the tower characteristics (KG a Z/L) corrected for these effects. Least square method was used to correlate the experimental results for (Ko a Z/L) in terms of air flux G and water flux L
SYSTEM PARALLELISATION FOR COMPUTER VISION
Authors: AL-Sudani Asaad A. M.
Published: March 2024

This paper delineates the parallelisation of a computer vision system. It presents the system proposal and the relevant design phases of a laboratory based model. This model involves special purpose hardware implementing the early stages of processing with very high data rate. It Incorporates facilities enabling the user to capture, retain, retrieve, compare, and analyse video images. The output of this hardware is to be processed by a software running in a parallel processor. The latter is a VMEbus-based multiprocessing machine accommodating the system hardware and ensures for better flexibility. It also participates in a reasonable distribution of the systern processing power. The kernel philosophy here depends on the concept of modularisation to attain higher degree of design consistency. It believes that the spatiotemporal pixel variation of two adjacent video frames involves sufficient information to detect movement. This implies pixel encoding and motion parameters estimation. The system software is based on a data compressive technique (Strip Encoding of Adjacent Frames) to solve the bottlenecks problem in the whole system throughput. The research hereby attempts to attain a match in the degree of sophistication between the system hardware and software structures. This yields to make the system processing power better meets the system applications requirements. The research investigates the above presented design phases along with their logical, functional, technical, and modular specifications. The research is adequate for development in a wide range of applications (requiring parallel architectures for image processing) like: Artificial Intelligence, Features Extraction and Pattern Recognition, Expert Systems, Computer Vision and Robotic Vision, Industrial Control, and other civil and military applications.
ANODIZING OF ALUMINUM-MAGNESIUM ALLOY USING CHROMIC ACID PROCESS
Authors: Al-Hemiri Adil A. , Al-Zameli Khalid A.
Published: March 2024

Aluminum-magnesium alloy has been anodized using chromic acid as an electrolyte. The effect of voltage in the range of 15-60V, electrolyte concentration in the range of 20-110 g/l, electrolyte temperature in the range of 30-60 °C and time of exposure in the range 25-85 minutes on the coating weight of the anodic film are studied. The experimental data was fitted in terms of the coating weight and the coefficients of third order polynomial are estimated. Optimum conditions of the studied variables are predicted and found equal to 32V, 85 g/1, 50 °C and 70 minutes.
PROBABILISTIC APPROACH TO MACHINE-COMPONENTS GROUPING IN CELLUAR MANUFACTURING SYSTEMS
Authors: Al-Daoud Zuhair I.A.
Published: March 2024

In this paper existing group technology techniques are reviewed and an alternative method using probabilistic approach to machine-components grouping in cellular manufacturing systems is introduced where it is based on production flow analysis, which uses routing information. A common feature of this approach is that it sequentially rearranges row and columns of the machine part incidence matrix according to predefined index and block diagonal is generated. The steps of this method are to assign the 1's in each row and column a probability weight, which alternately rearranged in descending order until a block diagonal matrix is created. It does not need to decide in advance, the number of required cells. It also overcomes the limitation of computational complexity, inherited in exiting group technology methods, especially for large scale and complex problems
EVALUATION OF THERMAL SRESSES IN CONTINOUOS CONCRETE BRIDGES
Authors: Abdul-Ahad Ramzi B. , Al--Wakeel Shahala’a A.
Published: March 2024

This search is mainly concerned with making a comparison between three methods for analyzingcontinuous concrete bridges, Priestly, Abdul-Ahad and finite elements. Three standard Designtemperature distribution, New Zealand, AASHTO and British (5400) were used to analyze theconcrete bridges in Baghdad. The analysis of two continues precast prestressed concrete bridges inBaghdad are presented. Another comparison as made between the thermal stresses and the stressassociated with dead and live loads. Analytical results indicated that stresses and curvature valuesare very sensitive to the type of temperature distribution assumed. The suggested analytical modelsfor the bridge can be used to be predict thermal movement and stresses due to any shape oftemperature distribution.
EFFECT OF STARVATION ON THERMOELASTOHYDRODYNAMIC LUBRICATION OF ROLLING / SLIDING CONTACT
Authors: Abbas Basim A. , Nacy Somer M.
Published: March 2024

A complete numerical solution of thermal compressible elastohydrodynamic lubrication of rolling /sliding contact was achieved to determine the effect of inlet boundary condition on the film shape,film pressure, and film temperature in an elastohydrodynamic line contact problem.The direct iterative technique is used to solve the simultaneous system of Reynolds, ,elasticity , andenergy equations for different locations of inlet oil fed . The effect of various load, speed , and slipconditions have been investigated . the results indicate that the effects of starvation are an increaseof oil film temperature and decrease in oil film thickness so that the temperature effect aresignificant and can not be neglected.
INFLUENCE OF VARIABILITY IN FLEXIBLE PAVEMENT PARAMETERS ON BACKCALCULATED MODULI
Authors: Ahmed Namir G.
Published: March 2024

Many researchers recommended Falling Weight Deflectometer (FWD) to be use for the purpose ofstiffness profile determination of existing pavement. Several sources of uncertainties contribute tothe inaccuracies in moduli obtained in this manner. these include: 1) the measured parameters(deflection basin and FWD load), 2) the back calculation model, and 3) the pavement parameters, such as Poisson's ratio and thickness of each pavement layer . In the present study the influence of the variation in the thickness and other pavement parameters on the backcalcuted moduli are investigated .Theoretical deflection basins were generated for different pavement structure using program Mich-pave. Mich-back program was then utilized to backcalculate the moduli from these theoretical basins. To assess the influence of the variability in thickness, Poisson's ratio, FWD load and deflection, a Monte Carlo simulation process was employed. Results show that the backcalculation of the layer moduli is greatly influence by the variability of the combined pavement. A sensitivity analysis showed that the uncertainties in thicknesses are the major contributor to variations of the backcalculated Moduli.
NATURAL CONVECTION FROM SINGLE FINNED TUBE IMMERRSED IN A TILTED ENCLOSURE
Authors: Fayed Ikhlase M. , Roomi Hadi R.
Published: March 2024

Heat transfer rates of a single horizontal finned tube immersed in water –filled enclosure tilted at 30 degrees are measured .The results serve as a baseline case for a solar water heating system with a heat exchanger immersed in integral collector storage. Tests were made with both adiabatic and uniform heat flux boundary conditions. Natural convection flow in enclosure is interpreted from measured water temperature distributions. Formation of an appropriate temperature difference that drives natural convection is determined .Correlations for the overall heat transfer coefficient in terms of the Nusselt and Rayleigh numbers are reduced to the form Nu=0.716 Ra 0.247 Based on the diameter of the immersed tube .Comparison the present workresults with others gave a good agreement
Numerical Simulation of Heat Transfer Problem in Hot and Cold Rolling Process
Authors: Hussain Ihsan Y.
Published: March 2024

An efficient numerical model had been developed to model the thermal behaviour of the rolling process. An Eulerian formulation was employed to minimize the number of grid points required. The model is capable to calculate the temperature distribution, the heat penetration depth, the convection heat transfer coefficient of cooling, the flow of metal through the roll gap, and the heat generation by plastic deformation and friction. The roll is assumed to rotate at constant speed, and the temperature variations are assumed to be cyclically steady state and localized with a very thin layer near the surface. The Conventional Finite Difference (CFDM) based on cylindrical coordinates was used to model the roll, and a Generalized Finite Difference Method (GFDM) with non-orthogonal mesh was employed in the deformed strip region and the roll-strip interface area. An upwind differencing scheme was selected to overcome the numerical instability resulting from the high velocity ( high Peclet number ) involved in the rolling process. The equations of the strip and roll are then coupled together and solved simultaneously. Both cold and hot rolling heat transfer behaviours, velocity distribution, and heat generation by deformation and friction under typical rolling conditions were presented to demonstrate the feasibility and capability of the developed numerical model. It has been found that, while the strip is under deformation, the bulk temperature inside the strip increases continuously; this is largely controlled by the deformation energy. On the other hand, the strip surface temperature changes much more drastically and it is mainly controlled by the friction heat and the roll temperature. The roll acts like a heat sink, because the coolant heavily cools it. Thus, as soon as the strip hits the roll its surface temperature drops. Since considerable friction and deformation heat are created along the interface and transferred from the neighboring sub-layer, the surface temperature picks up rapidly. Finally, the results of the temperature distribution for both cold and hot rolling and the heat generation by deformation and friction obtained from the present study were compared with previous published work to verify the validity of the numerical solution. Good acceptable agreements were obtained.
THEORETICAL SIMULATION OF STRESS-STRAIN RELATIONS FOR SOME IRAQICLAYS USING THE ENDOCHRONIC MODEL
Authors: Fattah Mohammed Yousif , Al-Hadidi Maysam Th. , Al-Gharbawi Akeel A.S.
Published: March 2024

A constitutive law can be defined as a mathematical functional relation between physical quantitiessuch as stress and strain and may take other factors like time, temperature and additional materialproperties into account. In this paper, the endochronic model is used to predict the stress-strain relations of two Iraqi clays. This model is a viscoplastic one but without introducing a yield surface. It encompassesmaterial behaviour such that the current stress state is a function of strain history through a time scale called “intrinsic time” which is not the absolute time but a material property. The simulation showed that the model overestimates the strains for all cases studied. This may be attributed to the material parameters which require a parametric study to determine their actual values for Iraqi clays.
AN APPROACH IN IMPROVING THE PROPERTIES OF SAND DUNES
Authors: AL-Abdullah Saad F.I.
Published: March 2024

An experimental study to improve sand dunes to gain economic construction of highway using these locally available materials. The study was divided into two approaches; the first was by using different bituminous binder proportions from (2) to (10) percent, while the second was to use fine metals as reinforcement. The results show an increase in the degree of improvement as reinforcement layers and silt contents were increased. Also it was found that 8% 0f asphalt cement increase the stabilization of sand dunes.
PREDICTION OF THE EFFICIENCY OF SIEVE TRAY USING AIRWATER SYSTEM
Authors: Al-Hemiri Adil A. , Hassan Muhannad Abdul Razaq
Published: March 2024

This investigation deals with the effect of weir height, liquid and gas flow rate on tray efficiency.The tests were carried out on a single pass cross flow tray of air-water system of 0.3 m diameter for clearliquid height over sieve tray with weir height 3, 4 and 5 cm.Point efficiency values were found to be in the same range for different weir height, but itimproves slightly with weir height. And the average values of point efficiency were 83 % for 3 cm weirheight, 85 % for 4 cm weir height and 89 % for 5 cm weir height. While, point efficiency of 90 % was obtained for 5 cm weir height and liquid flow rate ranging between 5.8 to 7.32 m3/s. In the range of clear liquid height over hole diameter ( hL/dH) between 2 to 10, increasing the Reynolds number ranging between 2.0*105 to 1.6*106 for gas phase increases point efficiency. Prediction of Murphree (Tray) efficiency using Lopez and Castells (1999) equation shows that the ratio of EMV/Ep is equal to 1, due to low value of calculated Peclet number (degree of liquid mixing), which ranged between 0.07 to 1.5.
DESIGN AND IMPLEMENTATION OF A TRANSPARENT SECURE LAN
Authors: Faraj Sufyan T. , Barjas Firas R.
Published: March 2024

Many attacks may be carried out against communications in Local Area Networks (LANs). However, these attacks can be prevented, or detected, by providing confidentiality, authentication, and data integrity security services to the exchanged data. This paper introduces a security system that protects a LAN from security attacks. On each host in the protected LAN, the security system transparently intercepts each outbound IP (Internet Protocol) packet, and inserts a crypto header between the packet IP header and payload. This header is used to detect any modification to the content of the packet in transit, and to detect replayed packets. Then, the system encrypts the IP packet payload and some fields of the inserted crypto header. On the other hand, the system transparently intercepts each inbound IP packet, decrypts its encrypted portions, and then uses its crypto header to authenticate the packet. If the packet is properly authenticated, thesystem indicates it to upper protocols. To be transparent to applications, the security system part that processes inbound and outbound IP packets was implemented as a NDIS (Network Driver Interface Specification) intermediate driver that resides between the LLC (Logical Link Control) and MAC (Medium Access Control) data link sublayers.
CURVATURE DUCTILITYOF REINFORCED CONCRETE BEAM SECTIONS STIFFENED WITH STEEL PLATES
Authors: Al-Azzawi Thamir K. , Al Azzawi Raad K. , Ibrahim Teghreed H.
Published: March 2024

This paper presents theoretical parametric study of the curvature ductility capacity for reinforced concrete beam sections stiffened with steel plates. The study considers the behavior of concrete and reinforcing steel under different strain rates. A computer program has been written to compute the curvature ductility taking into account the spalling in concrete cover. Strain rate sensitive constitutive models of steel and concrete were used for predicting the moment-curvature relationship of reinforced concrete beams at different rate of straining. The study parameters are the yield strength of main reinforcement, yield strength of transverse reinforcement, compressive strength of concrete, spacing of stirrups and steel plate thickness. The results indicated that higher strain rates improve both the curvature ductility and the moment capacity of reinforced concrete beam sections. Moreover the section curvature ductility increases as the thickness of the stiffening plates decreases.
Removal Method Assessment Through Reduction Algae Count in Uncovered water Reservoir
Authors: Salman Mohammed S. , Suhaili Rafa H. , Kassim Thaer I.
Published: March 2024

The Algae is considered as one of the major causes of some serious problems that occur in water plants, rivers, lakes and irrigation channels. Those problems are the unpleasant taste and odor, the clogging of waterways, and others. Hence, the algae existing extensively in any water body is considered as an obvious indication of surface water pollution. Chemical control methods were used in this research for reducing the turbidity and Algae in the laboratory using the (Jar Test). This was done by using chemical materials like Alum with concentration (10 - 50 mg/l). The percentage of the reduction in the algae was (95%) and in turbidity (94%). It is shown also that when using KMnO4, CuSO4 and Cl, each separately after adding the ideal dose of alum found before, will reduce the turbidity with ( 95% ,79.3% .95%) and algae removal of (99.2%, 100%, 99%) respectively
EQUILIBRIUM ADSORPTION OF METHANE ANDCARBON DIOXIDE ON 5A MOLECULAR SIEVE
Authors: Shua'ab Abbas Khalaf Mohammed
Published: March 2024

Experimental and theoretical studies have been carried out to study the adsorption of methane and carbon dioxide on 5A molecular sieve. Adsorption equilibrium isotherms of methane and carbon dioxide are reported for the temperature range 303– 333 K and pressure up to 2.5MPa. Experimental data were obtained using a static system for gas–solid adsorption. The Langmuir adsorption equilibrium equation gavegood predictions. Adsorption of methane and carbon dioxide on 5A molecular sieve is purely physical since the isosteric heat of adsorption was found to be equal to 14.804 and 37.218 kJ mole-1 for methane and carbon dioxide, respectively.
UNSTEADY HYDRODYNAMIC AND THERMAL BOUNDARY LAYERS OVER A FLAT PLATE WITH UNIFORM INJECTION OR SUCTION
Authors: Hussain Ihsan Y. , Taha Abdul Wahab A. , Fleh Ayser M.
Published: March 2024

A computational algorithm for calculating the unsteady compressible and turbulent hydrodynamic and thermal boundary layers over a porous flat plate with uniform suction or injection is developed in the present work. The mathematical modeling involves the derivation of the governing partial differential equations of the problem. These are the continuity, the momentum, the ( κ −ε ) turbulence model and the energy equations. Besides, the perfect gas law and the Sutherland' s law of molecular viscosity are also used. A proper initial and boundary conditions are specified to be used in the solution of the governing equations. A numerical solution of the governing equations is made by using the control volume approach, with non-staggered grid technique and modified SIMPLE algorithm. The numerical solution is capable of calculating the velocity and temperature distributions of the calculation domain, the kinetic energy and dissipation of turbulence, the local and average skin-friction and heat transfer coefficients and Nusselt number, and the hydrodynamic and thermal boundary layers thicknesses. All these parameters are calculated at the transient and steady states. The numerical results show that the developed algorithm is capable of calculating the flow field, properly and accurately. The results show that injection causess light decrease in the temperature inside the thermal boundary layer, a decrease in skin – friction coefficient, a slight increase in the Nusselt number, a decrease in hydrodynamic boundary layer thickness, an increase in thermal boundary layer thickness and an increase in the time required to reach the steady state. Suction almost causes reverse effects.
بعض بدائل االسكان المفضل في مدينة بغداد
Authors: حويش لؤي طه المال , جمعة انتصار قدوري
Published: March 2024

Housing planning is one of the most important subjects in the housing sector studies. Itis wide and has many branches . .Housing planning according to the cost and social benefit is the solution to prevent theescalating rise in Housing shortage .This fact is combined with which is estimated at more than three million housing unit .And big a reduction in housing construction rate , which lead to increase the housing problemin the country. This matter needs a clear policy from the authorities to accelerate the planningprocess and to adopt that strategy to solve the housing problem in Iraq.This strategy should adopt the principal of constructing low – cost housing complexesthrough the construction of multi-stories unit (3-4 stories) , the economic results will bedecrease in case of increase the stories to more than (4) stories because of the buildingsrequired to the lift and other services, as aresult the cost of the execution and maintenance willbe increase, especially when the technical cadres and the technology of the building and theadministration were unimproved , in addition to other psychological elements resulting fromthe highly buildings , there is no domain to talk about it . and of the efficient characteristicswhich these units have suitable residential densities , active and economic land use andreducing the housing cost to face the big shortage and increased housing demand.The research has conducted a field study of three housing complexes (3-5) stories forthe purpose of evaluating this type of housing and the extent if serves the social benefit andcomplain to design and planning criteria proposed in the General housing plan for Iraq.The research employ (cost & Benefit Analysis) to choose the best alternative fromthree housing complexes (hay Alsalam , Ziyona , Alsaidia) which serves low cost and best benefit.The research concludes to the importance of depending housing complexes (3-4)stories , and using light weight concrete is emphasized which one of the alternative fortraditional building materials as bricks which has many specifications , saving in cost andlabor , and reduction in time of construction , and solve of environment cases ,and choose thebest alternative from three housing complexes (hay Alsalam , Ziyona , Alsaidia) which serveslow cost and best benefit .
TREATMENT OF COLLAPSIBILITY OF GYPSEOUS SOIL
Authors: Al-Busoda Bushra S. Zbar
Published: March 2024

A series of double odometer tests are conducted to study the compressibility and collapse ofgypseous soil taken from west of Baghdad governorate. The gypsum content of the soil used isnearly 25%. Four different types of additives are selected to reduce the collapse strain of this soil.These additives are cement, bentonite, calicium chloride and silicagel. An adequate reducing in the compressibility and collapsibility was obtained especially when the cement is used.
تقويم الجريان غير المشبع لمبزل الحر تحت الظروف الحقمية لتربة مزيجة طينية غرينية :ألتنبأ عن األيصالبة المائية غير المشبعة ومقدات المحتوى المائي
Authors: سالم سموم برغوث , صالح أفراح مهدي
Published: March 2024

Since no in situ studies exist for determining unsaturated hydraulic characteristics of Iraqi soilsduring internal drainage under no evaporation conditions, a field study was conducted on a silty clay loam soil to determine unsaturated hydraulic conductivity using the Instantaneous ProfileMethod(IPM) and to solve the one dimensional flow equation under gravity flow theory for obtaining easier method to predicting unsaturated hydraulic conductivity and water content profiles. An 8m  8m field plot was flooded for forty days and then covered to prevent evaporation from soil surface. Gravimetric samples were augured during 90 days of drainage following flooding as a function of depth. Soil water potentials was estimated from fitting a functional relation to laboratory measured water content and matric potential relations for the studied soil horizons. Unsaturated hydraulic conductivity was calculated according to Darcian flow theory. Unit gradient theory was used to obtain an analytical solutions for the general flow equation according to Lax-Sisson method by utilizing three explicit K(θ) functions. Unsaturated conductivity values for the studied layers ranged from 1.0964 to15.2389 cm.d-1 and from 0.00001 to 0.0004 cm.d-1 after 0.025d and 88.75 d of drainage respectively. A 1:1 relationship between measured and predicted conductivities reveled highly significant r-squared values of 0.918, 0.933, and 0.927 for the three functions respectively. Predicted conductivity values were higher by factors 1.378, 1.418, and 1.296 for the three equations respectively. Same amount of water was drained from studied depths during drainage cycle which resulted in parallel water content profiles. Except at the early drainage time, predicted water contents profile with Lax-Sisson's method matched satisfactorily measured water content profiles. Also 1:1 relationship of zero-intercept between measured and predicted water content values during drainage period produced high r-squared values of 0.960, 0.935, and 0.918 for the three functions respectively. Predicted water content values were higher by a factor 1.008, 1.011, and 1.043 than measured values for the three functions respectively. Results of this study showed that the Lax-Sisson's method was accurate in predicting unsaturated hydraulic conductivity and water content profiles under theory Of gravity drainage flow.
IMPROVED DATA DETECTION PROCESSES USING RETRAINING OVER TELEPHONE LINES
Authors: Abdullah Sarcote.N..
Published: March 2024

This paper describes two new developed detection processes for a modem over the publicswitched telephone network. The modem is a synchronous serial system using a 16-pointQAM signal with a detector. The detector is preceded by an adaptive filter that is adjustedto make the sampled impulse response of the channel and filter minimum phase. The ideaof these two new detectors is to transmit a known retraining data every specified intervaland make use of these known data to improve the conventional nonlinear equalizer andnear maximum likelihood detector.Results of computer simulation tests are presented comparing tolerance to additive whiteGaussian noise with retraining and with out retraining. The detectors with retrainingachieve a better noise performance than conventional detectors. Furthermore the amountof retraining data is varied to find the best compromise between efficiency of datatransmission and performance improvement
NUMERICAL INVESTIGATION OF TURBULENT NATURAL CONVECTION IN AN INCLINED SQUARE ENCLOSURE
Authors: Mehdi Qasim S. , Mushatet Khudheyer S.
Published: March 2024

Two dimensional turbulent natural convection heat transfer and fluid flow inside an air filled inclined square enclosure differentially heated has been numerically studied. Fully elliptic Navier- Stockes and energy equations are solved using finite volume method. The problem is simulated for different angles of inclination ( 0   180deg. ) and Rayleigh numbers ( 8 16 10  Ra  10 ). The turbulence k-є model is used to model the effect of turbulence. The wall function approach is used to model the regions near the walls of the enclosure. The obtained results from this study show that the rate of heat transfer is increasedwith the increase of Rayleigh number and decreased with the increase of angle of inclination( 0   90deg. ).Also the induced vortices are strongly elongated with increase of Rayleigh number. The thickness of thermal boundary layer is decreased with the increase of Ra. The validation of the present code was done by comparing the computed results with the published ones. The comparison indicated a good agreement.
THE EFFECT OF TEMPERATURE AND ACID CONCENTRATION ON POLARIZATION RESISTANCE FOR A CORROSION REACTION UNDER ACTIVATION CONTROL
Authors: Yaro Aprael Sarguis
Published: March 2024

The effect of temperature ( 30,40,50,and 600C) on the polarization resistance (Rp) has beenanalyzed for the corrosion of carbon steel in 1,3, and 5N HCl solution in absence & presence ofphenylthiourea(PHTU) as corrosion inhibitor.The polarization resistance was measured at abovementioned conditions using BETACRUNCH program developed by Green and Gandi[Green,1982]. i.e; Values of applied current densities at potentials of +20,+10,-10 mv and then -20,+10,-10mV(SCE) from corrosion potentials were used to obtain corrosion parameters: iCorr ,ba bc followed by applying the equation: Rp = ( ba bc )/ 2.303 x iCorr.( ba + bc ).It is observed that: (i) for a certain acid concentration the polarization resistance decreased with increase in temperatureand/or decrease in inhibitor concentration.(ii) for a certain temperature, the polarization resistance decreases with an increase in acid concentration in presence and absence of inhibitor.
DIFFERENCE BETWEEN OF PWM STRATEGIES FOR INVERTER FED INDUCTION MOTOR
Authors: حسين محمد
Published: March 2024

Several sophisticated or "optimum" modulation strategies have been suggested for voltage source pulse with modulated (PWM) inverters for ac motor control. These modulation strategies may suppress specific low – order harmonics or minimize total harmonic.The effectiveness of these (PWM) techniques in minimizing harmonic and reducing torque pulsation is investigated analytically, and their performance is compared with that of the usual sinusoidal or sub-harmonic PWM approach. The influence of skin effect on motor (I2R copper losses) is taken into consideration, and harmonic core losses are compared. Peak current is also an important factor in inverter design, and the various modulation strategies are again compared on this basis. Fourier analysis techniques are used in order to allow skin effect phenomena to be taken into consideration and performance criteria are developed to allow comparisons of waveform quality with respect of harmonic copper and iron losses.
HEAT AND MASS TRANSFER DURING AIR DRYING OF SWEET POTATO
Authors: AL-Hafidh Manal H.
Published: March 2024

This study included the convective air drying of a single sweet potato sample which is taken as an ellipsoid with (40mm) in the longitudinal direction and (20mm) in the thickness direction. Convective heat and mass transfer takes place between the sample surface and its drying environment; while, unsteady heat conduction and moisture diffusion take place within the drying body without phase change for liquid (evaporation occurs at the surface only). The numerical solution of the mass, energy conservation equations was used; by applying the finite difference technique after using the body fitted coordinate system with grid generation techniques. A set of empirical correlations have been employed to determine the product properties and the important affecting factors on the drying process were studied. The results showed that the product temperature is increased and its moisture content is decreased with time and the increase in air velocity caused an increase in the heat transfer coefficient and as a result moisture content will decrease and this accelerates the drying process. The numerical results were compared with experimental results and showed good agreement.
STUDYING OF HEATED WATER RELEASED FROM SOUTH-BAGHDAD ELECTRIC POWER STATION TO THE TIGRIS RIVER
Authors: Al-Mosewi Tariq J. , Al-Mosewi Tariq J. , Al-Hashimi Mohammed Ali I.
Published: March 2024

Thermal pollution occurs when heated wastewater is discharged into rivers, lakes, oceans, or other water bodies. This will raise the temperature of the water body above its normal level and, consequently, will harm the aquatic live.Thermal Pollution problems will intensify as electricity usage increases unless substantial changes are made in the mode of discharge of the heated water. This paper is aimed to study the effects of heated water released from South-Baghdad Power Station on the water quality of Tigris River. Many parameters are test such as: Temperature (T), Total suspended solids (TSS), Total Dissolved Solids (TDS), Electrical Conductivity (EC), Hydrogen Ion (pH) and the dissolved oxygen (DO). Other parameters are tested to describe the heated water components such as Biochemical Oxygen Demand (BOD), Oil+Grease, and PO4.These parameters are compared with the allowable limits of rivers according to the Iraqi standards NO.25/1967 and found that some parameters exceed the allowable limits
AN EXPERIMENTAL STUDY OF BURR FORMATION IN DRILLING AND SLOT-END MILLING OPERATIONS
Authors: ALRABII S. A.
Published: March 2024

This paper presents the results of an experimental study on the influence of the main cutting parameters on burr formation and its types in drilling and slot-end milling operations to machine low carbon and stain -less steels using HSS cutting tools and cutting fluid. Particular attention was focused on the relation between the burr type and size and cutting parameters. Therefore, a wide range of cutting speeds, feed rates, and dept of cuts were investigated to explore the optimum cutting conditions. Burr heights were measured and anal- lyzed at different machining conditions to determine the effect of the cutting speed, feed rate, and depth of cut on burr formation. The data obtained for low carbon steel were compared with those for stainless steel. Different diameters of HSS twist drills were used to observe their effects on drilling burr formation. The quantitative measurements of burrs height yield much useful information because relatively uniform small and large burrs were formed under these conditions
THE EFFECT OF COARSE AGGREGATE RATIO ON THE PROPERTIES OF NO FINE LIGHT WEIGHT CONCRETE
Authors: HAMAD Hind.H. , Zghair Luma Abdul. Ghani.
Published: March 2024

The main object of this work is to study the effect of coarse aggregate/cement ratio (A/C) on the property of no fine concrete. In this work, three ratio of A/C were used (6, 9 and 12 by weight).The cement content is maintained constant (125kg/m3) while the w/c ratio ranges from (0.39 to 0.55 by weight). Tests are carried out on hardened concrete to investigate the effect of coarse aggregate/cement ratio on the compressive strength, absorption%, density, porosity%, ultrasonic pulse velocity, acoustic impedance of mixes.The results showed that increasing the percentage of A/C ratio by weight from 6 to 12 for the used mixes reduces the compressive strength, ultrasonic pulse velocity and acoustic impedance, on the other hand the porosity and the absorption percentage, increase with increasing ratio of A/C for all studied mixes.At 28 days the compressive strength , ultrasonic pulse velocity and acoustic impedance tests with A/C ratio of (12) are (2.8.MPa), (2km/sec) and (3×106 Kg/(sec.m2)) respectively while decreasing the ratio to (6) improves these properties to (9.3MPa), (3km/sec) and ( 5.7 ×106 Kg/(sec.m2)) respectively On the other hand the porosity and the absorption % decrease with decreasing the ratio of A/C for all studied mixes . At 28 days the porosity and the absorption % with A/C ratio of (12) are (40%) and (2.7%) respectively with decreasing the ratio to 6 decrease these properties to (19%) and (1%) respectively.The densities of the mixes were tested. At 28 days the density with A/C ratio of (12) are (1512 kg/m3 )with decreasing the ratio to 6 increase the density to(1907 kg/m3 )Based on the analysis of experimental results, several graphs and tables have been prepared to study the properties of no fine concrete
AN INVESTIGATION INTO THREE DIMENSIONAL TURBULENT FLOW OF NEWTONIAN LIQUID IN STIRRED TANKS MIXERS
Authors: Hussian Ihsan Y. , Hadi Nizar Jawad
Published: March 2024

The present work is concerned with the theoretical and experimental investigation of flow pattern of Newtonian fluid in liquid mixing process in stirred tank with flat blade impeller. A threedimensional model for mixing process was simulated. The effected parameters are rotation speed and impeller diameter. Continuity, momentum, and turbulent equations were solved by ANSYS package software 5.4 code with FLOTRAN/CFD based on Finite Element method. In the experimental work, two visualization methods are used in this work, the first method is the acidbase reaction visualization method and the second is the particle distribution visualization method.Different chemical materials were used in the first method, NaOH as a base, 2 4 H SO as acid and Methyl red as indicator, while polymer particles were used in the second method. The results of 3D model showed that the speed rotation directly affected the mixing zones, where the speed reduction by half decreasing the mixing zones approximately by half. Also the impeller diameter increasing clearly affected the mixing process where the mixing zones concentrated directly above and below the impeller. In the experimental work, the acid-base reaction visualization method showed that the mixing zones decreased due to the rotation speed reduction depend on the red and yellow colors, which describe the good mixing and poor mixing zones respectively. The mixing zones were concentrated directly above and below the impeller due to the impeller diameter increasing,. The particles distribution method showed that the mixing zones decreased due to the speed reduction, while the mixing zones concentrated directly above and below the impeller due to the impeller diameter increasing. The results showed a good agreement between the theoretical and experimentalworks in studying the effect of rotating speed, and impeller diameter .
FLOW SEPARATION OF AXIAL COMPRESSOR CASCADE BLADES
Authors: Al-Taie Arkan Kh. , Habeeb Sabah Faleh
Published: March 2024

An experimental and theoretical investigation of the effect of flow separation on the performanceof a cascade NACA 65_(12)10 axial compressor blade has been carried out. The experimental workincludes the fabrication of three blades from wood, each having a chord (100mm) but one of these blades having a span of (90mm) for smoke tunnel testing and the other two blades having a span of (380mm) for wind tunnel testing.The two blades were connected by suitable mechanism in order to be fixed in the wind tunnel protractor and rotated in the required stagger angle. The cascade was tested in an open type low-speed subsonic (Mach number=0.117) wind tunnel, for Reynolds number (Re=239605) based on maximum velocity (35 m/s) and airfoil chord length. The total and static pressures were measured in selected points between the two blades for stagger angles of (4 0 , 0 0 ,- 4 0 ,-8 0 and -120) by using a multi-tube manometer and a pitot static tube. The small blade (90mm span) is tested in the smoke tunnel to visualize the real behavior of flow separation. The theoretical work includes using the software FLUENT (V6.2) to simulate the flow between the two blades. The study shows that the flow separation begins when the cascade are inclined at a stagger angle of (- 4 0 ) on the suction side of the lower blade at a position (96%chord experimentally and 98%chord theoretically). Then, the separation zone increases with increased stagger angle (in clockwise direction) and reach to the position (61%chord experimentally and 63%chord theoretically) at a stagger angle (-12 0 ).These results are validated by a smoke tunnel tests.This separation affects the performance of the compressor, where the static pressure ratio ( Sep /Sip ) decreases as the separation zone gets bigger. The range of working stagger angle is then calculated. It was found in the range (-18 0 to 36 0 ). The flow behavior between the two blades shows that the blade-to-blade configuration works as nozzle-diffuser. The theoretical results were compared with the experimental results and good agreement was obtained.
INVESTIGATION OF THE EFFECT OF THE WAKE GENERATED BY ROTOR BLADES ON THE FLOW THROUGH STATOR PASSAGE FOR LOW PRESSURE TURBINE
Authors: Hussain Ihsan Y. , Mustafa Ahmed W.
Published: March 2024

The effects of incoming wakes of upstream rotor on the flow field in a low pressure turbine cascade are investigated. The flow field is studied numerically with and without inlet wake. The rotor effect is represented by moving bars that produce passing wakes at the entrance of the stator. The flow field is analyzed numerically by solving the steady and unsteady forms of the two-dimensional compressible Reynolds-averaged Navier-Stokes equations. Steady flow is performed without wake while the unsteady flow is performed with periodic inlet wake for Reynolds number of order 105. A k- turbulence model is used to obtain the eddy viscosity. The Cartesian velocity components and pressure on a collocated (non-staggered) grid are used as dependent variables in the momentum equations, which discretized by finite volume method, body fitted coordinates are used to represent the complex blade geometry accurately, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The results show that the wake passing produces unsteady pressure field in the direction of the rotor traverse. The comparison with the experimental data is acceptable and there is similar trend between the prediction and experimental data, except at the separation flow region due to the limitation of the turbulence model.
PREDICTION OF NATURAL CONVECTION HEAT TRANSFER IN COMPLEX PARTITIONS CAVITY
Authors: HABBEB SATTAR J. , DAOUD ISRAA Y.
Published: March 2024

A numerical investigation has been carried out to examine the effects of insulated baffle mounted in complex cavity representing as an industrial building on flow pattern and heat transfer characteristics. The cavity is formed by adiabatic horizontal bottom, inclined upper walls and vertical isothermal walls. This problem is solved by using flow-energy equations in terms of stream-vorticity formulation in curvilinear coordinates. Two cases are considered; in the first (case 1) the insulated baffle position attached to the horizontal bottom wall of the cavity while in the second case (case 2) the insulated baffle position attached the upper inclined wall. A parametric study is carried out using following parameters: Rayleigh number from 103 to 106, Prandtl number for 0.7 and 10, baffle height (HB=0, 0.3H*, 0.4H*, and 0.5H*), baffle location for (LB=0.25L and 0.75L) with or without baffle in the cavity (total of 100 tests). For case 1 results show that, the flow strength generally increasing with increasing Ra values, increasing baffle height, and decreasing values of Pr, while in case 2 the same behavior of above could be show except the flow strength decreasing with increasing baffle height, also, increase Ra leads to increase the rate of heat transfer. The configuration of the cavity in case 2 leads to increase in heat transfer rate comparing with that in case 1.
MODELING A PROCESS FOR THE REMOVAL OF CADMIUM FROM SIMULATED WASTEWATERS BY ELECTRODEPOSITION ON STAINLESS STEEEL TUBES BUNDLE
Authors: Sulaymon Abbas Hamid , Sharif Adel Obaid , Al-Shalchi Thana Kamil
Published: March 2024

Electrochemical processes can provide valuable contributions to the protection of the environment through implementation of effluent treatment and production-integrated processes for theminimization of waste and toxic compounds. The performance of a novel pilot scale, batch re-cycled, flow-through cell, with stainless steel tubes bundle cathode in the removal of cadmium was investigated utilizing the potential results obtained from a batch mode. The studied electrochemical reaction was the cathodic reduction of Cd+2 using 0.5 M sodium sulphate as supporting electrolyte. The analyzed parameters were different initial Cd+2 concentrations (50,100, 200, 300, 400 ppm) and different electrolyte flow-rates (100, 200, 250, 300, 350 L/hr), the tubes number was 920 of 0.6 cm diameters.The overall empirical mass transfer correlation was found to be: Sh = 0.051 Re 0.859 Sc1/3For 5 < Re < 20 and Sc = 649 Experimental results, analysis and correlations showed good performance of the cell and proved its adequacy in the removal of Cd+2 from simulated effluents.
NEURAL NETWORK APPLICATION FOR BUILDING PROJECTS COST ESTIMATION
Authors: Al-daoud Zouhair , Humod Ali Mohamed
Published: March 2024

This work presents a neural network based cost estimating method, developed for the generationof conceptual cost estimates for total building and electromechanical systems in building project,by using eight parameters available at the early design phase. This model establishes amethodology that can provide an economical and rapid means of cost estimating. Eighteen lighrise building projects, built between 1996 and 2009 in Middle East countries used in this study.The performance of developed cost models was tested against costs incurred by projects not usedin training of those models. Results show the mean absolute percentage errors (MAPE) arebetween 1.51% and 4.771 % for the five networks, and the maximum/minimum deviation of thecost estimation is 10.2/0.17. These figures considered good cost estimation at the early designstage.