This research provides information on the heat transfer in the cavity by natural convection which has a partially open side with a ratio (A = 1, 0.75, 0.5, 0.25) to the surroundings for cooling. It is filled with porous media (glass beads) and saturated with air. The bottom wall was heated with a constant heat flux (q = 1500, 3000, 4500, 6000) W/m2 while the top and other walls of the cavity were well insulated. The porous media had small porosity (0.418), a range of Rayleigh number Ra (57.6-1470). The distribution of temperatures, the local Nusselt number, and the average Nusselt number were all extracted from the testing rig's temperature data. It is clear that the fluid flow and heat transfer are affected b
... Show MoreMost of the structures subjected to load tests had successfully passed it, although some of them had failed in cube and core tests. It is believed that membrane action may be the most important factor that made them do so. In the present study, an attempt is made to study the effect of membrane action on load test results. In this study, two space (3-D) model frames, nine panels (3×3), [consisted of rafts, columns, beams and slabs] were prepared for load test. The results show the positive role of the membrane action especially with camber beams and slabs in successful passing of the load test. Also there is enhancement in the deflection behavior of camber members compared with straight members.
Physical Layer Key Generation (PLKG) provides a promising approach for establishing secure cryptographic keys between legitimate parties. However, in static and quasi-static environments, the key generation rate is significantly limited due to the low entropy of the wireless channel. To overcome this, Reconfigurable Intelligent Surfaces (RIS) have been proposed to enhance the channel entropy by altering the phase of incident electromagnetic waves. This paper addresses this challenge by proposing a security architecture that integrates a Multi-Input Multi-Output (MIMO) base station with a Beyond-Diagonal Reconfigurable Intelligent Surface (BD-RIS) in multi-user scenarios, in the presence of an eavesdropper. Unlike convent
... Show MoreStatic behavior (under torsion and bending loading) of machine tool column was studied in this paper. The effects of changing the cross sectional area of the column itself on the deformations (design parameters) was investigated. The adding of stiffeners and changing the stiffeners cross sectional area are also verified. The results show that using of stiffeners can produse a great reduction in deformation of the column structure under the stastic loading mentioned above. Also using stiffeners with different cross-sectional areas suggest the best stiffener cross-sectional shape can be used to give the minimum deformations of column structure. Dynamic analysis of column involves calculating natural frequencies and mode of different column
... Show MoreThis research was conducted to study the feasibility of using fruit peels as biosorbent for removal of Pb+2, Cu+2 and Zn+2 ions from simulated wastewater. A waste biomass of Pomegranate Peel or Punicagranatum L. (P. granatum L.) was chosen as neutral biosorbent in this study.Fourier transformation infrared (FTIR) was used to characterize the surface of PGP, the results confirm that amino, carboxylic, hydroxyl and carbonyl group on the surface of PGP. Different parameters such as initial concentration range between (25-200) mg/L, pH (3-7), contact time (1-2) hour, amount of sorbent (0.1- 4) gm, agitation speed range (200- 500) rpm and temperature (25- 50oC), influencing the sorp
... Show MoreA general velocity profile for a laminar flow over a flat plate with zero incidence is obtained by employing a new boundary condition to the other available boundary conditions. The general velocity profile is mathematically simple and nearest to the exact solution. Also other related values, boundary layer thickness, displacement thickness, momentum thickness and coefficient of friction are nearest to the exact solution compared with other corresponding values for other researchers.
In general, path-planning problem is one of most important task in the field of robotics. This paper describes the path-planning problem of mobile robot based on various metaheuristic algorithms. The suitable collision free path of a robot must satisfies certain optimization criteria such as feasibility, minimum path length, safety and smoothness and so on. In this research, various three approaches namely, PSO, Firefly and proposed hybrid FFCPSO are applied in static, known environment to solve the global path-planning problem in three cases. The first case used single mobile robot, the second case used three independent mobile robots and the third case applied three follow up mobile robot. Simulation results, whi
... Show MoreThe efficiency of internal combustion engines (ICE) is usually about thirty percent of the total energy of the fuel. The residual energy is lost in the exhaust gas, the lubrication, and the cooling water in the radiators. Recently much of the researcher’s efforts have focused on taking advantage of wasted energy of the exhaust gas. Using a thermoelectric generator (TEG) is one of the promising ways. However, TEG depends entirely on the temperature difference, which may be offered by the exhaust muffler. An experimental test has been conducted to study the thermal performance of a different muffler internal design. The researchers resort to the use of lost energy in an ICE using TEG, which is one of the ways to take adv
... Show MoreEnhancement of heat transfer in the tube heat exchanger is studied experimentally by using discrete twisted tapes. Three different positions were selected for inserting turbulators along tube section (horizontal position by α= 00, inclined position by α= 45 0 and vertical position by α= 900). The space between turbulators was fixed by distributing 5 pieces of these turbulators with pitch ratio PR = (0.44). Also, the factor of constant heat flux was applied as a boundary condition around the tube test section for all experiments of this investigation, while the flow rates were selected as a variable factor (Reynolds number values vary from 5000 to 15000). The results s
... Show MoreThe effective stress method is developed to predict the axial capacity of piles in clay. This
method is based on the principle that, at failure, the available shear resistance at the pile soil
interface is related to the mean normal effective stress at the pile face and the effective stress
friction angle for the soil sliding on the pile material.
In this paper, the coupled non-linear finite element method is used to analyze some pile-soil
interaction problems. This computer program ( CRISP ) is used for this task. Eight- node
isoparametric elements were used for displacements while four- node elements are used for
pore pressure. Interface elements are used to simulate the interaction between the pile and the
soil
Practically, torsion is normally combined with flexure and shear actions. Even though, the behavior of reinforced concrete continuous beams under pure torsion is investigated in this study. It was performed on four RC continuous beams under pure torsion. In order to produce torsional moment on the external supports, an eccentric load was applied at various distances from the longitudinal axis of the RC beams until failure.
Variables considered in this study are absolute vertical displacement of the external supports, torsional moment’s capacity, angle of twist and first cracks occurrences. According to experimental results; when load eccentricity increased from 30cm to 60cm, the absolute vertical displacement i
... Show MoreThis paper presents a nonlinear finite element modeling and analysis of steel fiber reinforced concrete (SFRC) deep beams with and without openings in web subjected to two- point loading. In this study, the beams were modeled using ANSYS nonlinear finite element
software. The percentage of steel fiber was varied from 0 to 1.0%.The influence of fiber content in the concrete deep beams has been studied by measuring the deflection of the deep beams at mid- span and marking the cracking patterns, compute the failure loads for each deep beam, and also study the shearing and first principal stresses for the deep beams with and without openings and with different steel fiber ratios. The above study indicates that the location of openings an
An experimental investigation was made for the study of incompressible flow on a circular disc. It consists of two parts. The first was the determination of the pressure distribution of the front an! rear sides of three samples of dises with diameters 9.73,10.75 and 11.94cm and 3mm thickness.Th: dises were mounted normal to the flow direction. This part also included the determination of pressure distribution on the front and rear sides of an inclined dise of 10.75 cm diameter it inclination angles of 30, 60, 120, and 150 to the horizontal. The second part of the investigation was the determination of the drag coefficient on a circular disc 10.75 cm in diameter and 3 mm in thickness using two methods. The first using strain gages as sens
... Show MoreResearch in Iraq has expanded in the field of material technology involving the properties of the lightweight concrete using natural aggregate. The use of the porcelinate aggregate in the production of structural light concrete has a wide objective
and requires a lot of research to become suitable for practical application. In this work metakaolin was used to improve compressive strength of lightweight porcelinate concrete which usually have a low compressive strength about 17 MPa . The effect of metakaolin on compressive, splitting tensile, flexure strengths and modulus of elasticity of lightweight porcelinate concrete have been investigated. Many experiments were carried out by replacing cement with different percentages of
met
The Multiple Signal Classification (MUSIC) algorithm is the most popular algorithm to estimate the Angle of Arrival (AOA) of the received signals. The analysis of this algorithm (MUSIC) with typical array antenna element ( ) shows that there are two false direction indication in the plan
aligned with the axis of the array. In this paper a suggested modification on array system is proposed by using two perpendiculars crossed dipole array antenna in spite of one array antenna. The suggested modification does not affect the AOA estimation algorithm. The simulation and results shows that the proposed solution overcomes the MUSIC problem without any effect on the performance of the system.
In this study regeneration process was carried out for exhausted activated carbon, which has been used for adsorption process of furfural from its solution by three different methods (washing with dilute alcohol ethanol 20%, washing with boiled distilled water at 100Co؛ and thermal processat (200 – 900) Co؛. The regenerated activated carbon has been reused in the column system of fixed
– bed in order to estimate the adsorption quantities and comparing the value with adsorptionquantity of original activated carbon under same condition (furfural with concentration 0.2 kg/m³,bed depth 5 cm, flow rate of liquid 16.16 × 10-5 m³/min and particular size of activated carbon (1.5-0.5) mm) in order to estimate the regeneration efficie
Free vibration solution will be developed for laminated simply supported closed cylindrical shells. This solution is obtained using General Third Shell Theory (G.T.T.). Also the critical in-plane fatigue load is studied and the required equilibrium equations are developed, the effects of tension or compression in-plane load on the natural frequencies are discussed also. The natural frequencies and in-plane fatigue load results are very close to those obtained by other researchers.
In order to design structures on soft soils, it is necessary to predict the behavior of the soft soil
under imposed structure load. The high excessive settlements of the soft soil can cause many
problems for the structures built on the soil like cracking and breakup of pavements, railway,
highway embankments, etc...
In this work, the finite element method is utilized as a tool for carrying out different
analyses of embankments on soft ground with different conditions. The computer program CRISP
(CRItical State Program) is developed to suit the problem requirements. CRISP uses the finite
element technique and allows predictions to be made of soil deformations using the critical state
theory.
Eight-node isoparame
This research includes the using of statistical to improve the quality of can plastics which is produced at the state company for Vegetable oils (Almaamon factory ) by using the percentage defective control chart ( p-chart ) of a fixed sample. A sample of size (450) cans daily for (30) days was selected to determine the rejected product . Operations research with a (win QSB ) package for ( p-chart ) was used to determine test quality level required for product specification to justify that the process that is statistically controlled.
The results show high degree of accuracy by using the program and the mathematical operations (primary and secondary ) which used to draw the control limits charts and to reject the statistically uncontr
Variation order plays an important role in calculating the final cost and time. The paper aims to determine the causes of variation orders in projects performed between 2007-2014 in Erbil governorate projects. Data was collected from contract documents. Performed in the Erbil governorate projects from 2007-2014. The study seeks to identify the most significant causes of delays by assessing the common causes of delays in terms of frequency, severity and
important indices of owners, consultants and contractors related to&n
... Show MoreWith wireless sensor network (WSN) wide applications in popularity, securing its data becomes a requirement. This can be accomplished by encrypting sensor node data. In this paper a new an efficient symmetric cryptographic algorithm is presented. This algorithm is called wireless sensor network wavelet curve ciphering system (WSN-WCCS). The algorithm idea based on discrete wavelet transformation to generate keys for each node in WSN. It implements on hierarchical clustering WSN using LEACH protocol. Python programming language version 2.7 was used to create the simulator of WSN framework and implement a WSN-WCCS algorithm. The simulation result of the proposed WSN-WCCS with other symmetric algorithms has show
... Show MoreMethods of speech recognition have been the subject of several studies over the past decade. Speech recognition has been one of the most exciting areas of the signal processing. Mixed transform is a useful tool for speech signal processing; it is developed for its abilities of improvement in feature extraction. Speech recognition includes three important stages, preprocessing, feature extraction, and classification. Recognition accuracy is so affected by the features extraction stage; therefore different models of mixed transform for feature extraction were proposed. The properties of the recorded isolated word will be 1-D, which achieve the conversion of each 1-D word into a 2-D form. The second step of the word recognizer requires, the
... Show MoreAsset management involves efficient planning of economic and technical performance characteristics of infrastructure systems. Managing a sewer network requires various types of activities so the network can be able to achieve a certain level of performance. During the lifetime of the network various components will start to deteriorate leading to bad performance and can damage the infrastructure. The main objective of this research is to develop deterioration models to provide an assessment tool for determining the serviceability of the sewer networks in Baghdad city the Zeppelin line was selected as a case study, as well as to give top management authorities the appropriate decision making. Different modeling techniques
... Show MoreIn the present work the performance of semifluidized bed adsorber was evaluated for removal of phenolic compound from wastewater using commercial activated carbon as adsorbent. P-chlorophenol (4-Chlorophenol) and o-cresol (2-methylphenol) was selected as a phenolic compound for that purpose. The phenols percent removal, in term of breakthrough curves were studied as affected by hydrodynamics limitations which include minimum and maximum semifluidization velocities and packed bed formation in the column by varying various parameters such as inlet liquid superficial velocity (from Uminsf to 8Uminsf m/s), and retaining grid (sometimes referred to as adsorbent loading) to initial static bed height ratio (from 3-4.5). In
... Show MoreElectrical distribution system loads are permanently not fixed and alter in value and nature with time. Therefore, accurate consumer load data and models are required for performing system planning, system operation, and analysis studies. Moreover, realistic consumer load data are vital for load management, services, and billing purposes. In this work, a realistic aggregate electric load model is developed and proposed for a sample operative substation in Baghdad distribution network. The model involves aggregation of hundreds of thousands of individual components devices such as motors, appliances, and lighting fixtures. Sana’a substation in Al-kadhimiya area supplies mainly residential grade loads. Measurement-based
... Show MoreRock engineers widely use the uniaxial compressive strength (UCS) of rocks in designing
surface and underground structures. The procedure for measuring this rock strength has been
standardized by both the International Society for Rock Mechanics (ISRM) and American Society
for Testing and Materials (ASTM), Akram and Bakar(2007).
In this paper, an experimental study was performed to correlate of Point Load Index ( Is(50))
and Pulse Wave Velocity (Vp) to the Unconfined Compressive Strength (UCS) of Rocks. The effect
of several parameters was studied. Point load test, Unconfined Compressive Strength (UCS) and
Pulse Wave Velocity (Vp) were used for testing several rock samples with different diameters.
The predicted e
The development of monitoring systems for rotating blade has been driven by a desire to reduce the maintenance costs and human interaction to improve the safety, reliability and operational life, so it is urgent to monitor the integrity of a structural systems. In this study four different coordinate system has been used to describe the blade motion, then an element stiffness and mass matrices has been formulated by using Hamilton's principle and finite element method, where each element has been described by seven degrees of freedom, so the method has been demonstrated analytically on a finite element model to estimate the modal parameters under rotating and non-rotating conditions in vacuum (to eliminate aerodynamic effect and damping
... Show MoreThis research introduces a developed analytical method to determine the nominal and maximum tensile stress and investigate the stress concentration factor. The required tooth fillets parametric equations and gears dimensions have been reformulated to take into account the asymmetric fillets radiuses, asymmetric pressure angle, and profile shifting non-standard modifications. An analytical technique has been developed for the determination of tooth weakest section location for standard, asymmetric fillet radiuses, asymmetric pressure angle and profile shifted involute helical and spur gears. Moreover, an analytical equation to evaluate gear tooth-loading angle at any radial distance on the involute profile of spur and hel
... Show MoreA microbial desalination cell (MDC) is a new approach to bioelectrochemical systems. It provides a more sustainable way to electrical power production, saltwater desalination, and wastewater treatment at the same time. This study examined three operation modes of the MDC: chemical cathode, air cathode, and biocathode MDC, to give clear sight of this system's performance. The experimental work results for these three modes were recorded as power densities generation, saltwater desalination rates, and COD removal percentages. For the chemical cathode MDC, the power density was 96.8 mW/m2, the desalination rate was 84.08 ppm/hr, and the COD removal percentage was 95.94%. The air cathode MDC results were different
... Show MoreGeneral Directorate of Surveying is considered one of the most important sources of maps in Iraq. It produced digital maps for whole Iraq in the last six years. These maps are produced from different data sources with unknown accuracy; therefore, the quality of these maps needs to be assessed. The main aim of this study is to evaluate the positional accuracy of digital maps that produced from General Directorate of Surveying. Two different study areas were selected: AL-Rusafa and AL-Karkh in Baghdad / Iraq with an area of 172.826 and 135.106 square kilometers, respectively. Different statistical analyses were conducted to calculate the elements of positional accuracy assessment (mean µ, root mean square error RMSE, mini
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