The steady-state injection into a semiconductor region was studied by many authors and various solutions were achieved.
The solutions gave the distribution of carriers inside such a region to aid in understanding devices operation. But extending this problem to a lightly doped semiconductor region was tackled by only few authors, and the solutions achieved were either numerical or analytical however, the analytical solution were sufiering from crude approximations,. This paper gives a realistic analytical solution, which considers both monomolecular and bimolecular recombination factors.
Twitter is becoming an increasingly popular platform used by financial analysts to monitor and forecast financial markets. In this paper we investigate the impact of the sentiments expressed in Twitter on the subsequent market movement, specifically the bitcoin exchange rate. This study is divided into two phases, the first phase is sentiment analysis, and the second phase is correlation and regression. We analyzed tweets associated with the Bitcoin in order to determine if the user’s sentiment contained within those tweets reflects the exchange rate of the currency. The sentiment of users over a 2-month period is classified as having a positive or negative sentiment of the digital currency using the proposed CNN-LSTM
... Show MoreMost below-knee prostheses are manufactured in Iraq without considering the fast progress in smart prostheses, which can offer movements in the desired directions according to the type of control system designed for this purpose. The proposed design appears to have the advantages of simplicity, affordability, better load distribution, suitability for subjects with transtibial amputation, and viability in countries with people having low socio-economic status. The designed prosthetics consisted of foot, ball, and socket joints, two stepper motors, a linkage system, and an EMG shield. All these materials were available in the local markets in Iraq. The experimental results showed t
... Show MoreThe transition of professionals between different sectors is considered as one of sources of
acquisition of technology and will lead to add the practical experience to them. This experience
depending on different factors like: the scientific degree and practical experience by the
professionals, the technology possessed by the transferor sector, the duration that spent by
experienced in transferor sector, the type of work performed by professional….etc.
The research aims to verify the affect of these factors in technology transfer process.
Research reached that the technology transfer process which is depending on the Iraqi competencies
in work is unsatisfied level between Iraqi organizations because there are dif
This paper studies the non-linear behaviour of a clayey Iraqi soil taken from Baghdad City, using the bounding surface plasticity model under static and dynamic loading. The bounding surface plasticity model needs a group of input parameters. Some of them are determined directly from triaxial and consolidation tests, while the others are evaluated from a parametric study using a computer program named EVAL.A series of advanced laboratory tests was performed after modifying and manufacturing some parts of the triaxial machine that are required for carrying out Ko-consolidtated compression and extension tests. The soil test results are used in a computer program named EVAL to compute the soil properties and input parameters for the Iraqi c
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Natural convection in an annular space provided with metal foam fins attached to the inner cylinder is studied numerically. The metal foam fins made of copper were inserted in different axial sections with three fins in each section. The temperature of the inner cylinder is kept constant while the annular outer surface is adiabatic. The thickness effect of the inner pipe wall was considered. Naiver Stokes equation with Boussinesq approximation is used for the fluid regime while Brinkman-Forchheimer Darcy model is used for metal foam. In addition, the local thermal non-equilibrium condition in the energy equation of the porous media is presumed. The effect of Rayleigh numb |
Unmodified and modified sunflower stalks were examined for adsorption as a replacement of expensive activated carbon which has been recognized as a highly effective adsorbent for the removal of heavy metal-ion.
Two modes of operation were used, batch mode and fixed bed mode. In batch experiment the effect of sunflower stalk doses (2,3,4,5 and 6g/L) with constant initial copper concentration of 100 mg/L and constant particle size less than1.18 mm was studied.
Batch kinetics experiments showed that the adsorption rate of copper ion by sunflower stalks was rapid and reached equilibrium within 60 min. Adsorption models Freundlich, Langmuir and Freundlich-Langmuir were fitted to experimental data and the goodness of their fit for adsorp
An experimental system was designed and built to produce the flash evaporation of upward water flow in a (1.8 m) vertical mounted glass test section pipe. The water loses the static head as it moves up, accordingly flash evaporation occurs somewhere inside the test section, where the water local temperature reaches its saturation temperature at that position, which is dependent on the water inlet temperature and its mass flow rate. The steam quality in the test section exit was measured by collecting the steam generated in the test section outlet and condensed in the condenser at specified time.
The hydrogen bubbles are injected inside the two-phase mixture flow within the test section. These bubbles act as an exciter for steam g
... Show MoreThis research involves design & implementation of fractional – N frequency synthesizer with the following specifications: Frequency range (2350– 2750) MHz,Step size (1 kHz), Switching time 8.9 μs, & phase noise @10 kHz = -115dBc & spurious -69 dBc The third order Fractional –N technique was chosen to satisfy the design requirements. In this system the modulator placed on digital phase-locked loop to control the fractional value of the
frequency division ratio thereby eliminating spurious and allowing good phase noise performance. The development in I.C. technology provides the simplicity in the design of fractional –N frequency synthesizer because it implements the phase frequency detector(PFD) , prescalar,modul
The low order panel method with Neumann boundary condition have been used to predict the
normal force curve slope, the pitching moment curve slope, the center of pressure location and the
aerodynamic load distribution for missile in compressible, steady flow. The wing-body-canard
interference problem have been solved using two schemes (iterative method and internal singularity
method) both are based on the panel method. The normal force curve slope, the pitching moment
curve slope and the center of pressure location for a given missile has been predicted using the
present numerical method and the DATCOM technique.
This study included three trials that were made during December 2003 by using lime, of 98% w/w
calcium hydroxide to find the relation between lime doses to be added and the hardness removed
.The trials were performed by adding various doses of lime and measuring the hardness, electrical
conductivity and pH in water produce by three plants, Nissan in the north of Baghdad, Al-Karama
and Al-Wathba water treatment plant in Baghdad center. The objective of this study is to find the optimum lime dose that gives the minimum hardness content. The results indicate a non linear relation between lime dose added and the hardness removed . The results represented a 36% removal in hardness when using an optimum dose of lime 200 ppm in Niss
Heuristic approaches are traditionally applied to find the optimal size and optimal location of Flexible AC Transmission Systems (FACTS) devices in power systems. Genetic Algorithm (GA) technique has been applied to solve power engineering optimization problems giving better results than classical methods. This paper shows the application of GA for optimal sizing and allocation of a Static Compensator (STATCOM) in a power system. STATCOM devices used to increase transmission systems capacity and enhance voltage stability by regulate the voltages at its terminal by controlling the amount of reactive power injected into or absorbed from the power system. IEEE 5-bus standard system is used as an example to illustrate the te
... Show MoreThis study examines the vibrations produced by hydropower operations to improve embankment dam safety. This study consists of two parts: In the first part, ANSYS-CFX was used to generate a three-dimensional (3-D) finite volume (FV) model to simulate a vertical Francis turbine unit in the Mosul hydropower plant. The pressure pattern result of the turbine model was transformed into the dam body to show how the turbine unit's operation affects the dam's stability. The upstream reservoir conditions, various flow rates, and fully open inlet gates were considered. In the second part of this study, a 3-D FE Mosul dam model was simulated using an ANSYS program. The operational turbine model's water pressure pattern is conveyed t
... Show MoreThe Sliding Mode Control (SMC) has been among powerful control techniques increasingly. Much attention is paid to both theoretical and practical aspects of disciplines due to their distinctive characteristics such as insensitivity to bounded matched uncertainties, reduction of the order of sliding equations of motion, decoupling mechanical systems design. In the current study, two-link robot performance in the Classical SMC is enhanced via Adaptive Sliding Mode Controller (ASMC) despite uncertainty, external disturbance, and coulomb friction. The key idea is abstracted as follows: switching gains are depressed to the low allowable values, resulting in decreased chattering motion and control's efforts of the two-link robo
... Show MoreHot mix recycling of asphalt pavements is increasingly being used as one of the major rehabilitation methods by various highway agencies. Besides general savings in costs and energy expended, it also saves our natural resources and environment. Recycling process presents a sustainable pavement by using the old materials that could be reclaimed from the pavement; these materials could be mixed with recycling agents to produce recycled mixtures. The important expected benefits of recycling process are the conservation of natural resources and reduction of environmental impact. The primary objectives of this work are evaluating the Tensile and Shear Properties of recycled asphalt concrete mixtures, In addition to the
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Compaction curves are widely used in civil engineering especially for road constructions, embankments, etc. Obtaining the precise amount of Optimum Moisture Content (OMC) that gives the Maximum Dry Unit weight gdmax. is very important, where the desired soil strength can be achieved in addition to economic aspects.
In this paper, three peak functions were used to obtain the OMC and gdmax. through curve fitting for the values obtained from Standard Proctor Test. Another surface fitting was also used to model the Ohio’s compaction curves that represent the very large variation of compacted soil types.
The results showed very good correlation between the values obtained from some publ
... Show MoreOne of the most important parameters determining structural members' durability and strength is the fire flame's influence and hazard. Some engineers have advocated using advanced analytical models to predict fire spread impact within a compartment and considering finite element models of structural components to estimate the temperatures within a component using heat transfer analysis. This paper presented a numerical simulation for a reinforced concrete beam’s structural response in a case containing Water Absorbing Polymer Spheres (WAPS) subjected to fire flame effect. The commercial finite element package ABAQUS was considered. The relevant geometrical and material parameters of the reinforced concrete beam model a
... Show MoreThe difficulty of building a secure network is due to the changing nature of the enterprise coupled with the increasing sophistication of the hacker threat, both from inside and outside of the network. Active networks enable individual user or groups of users to inject customized programs into the nodes of the network.
The proposed system depends on the basic concepts (authentication and authorization) and uses RSA algorithm to add additional level of security. The proposed system also depends on active packet architecture, the packet will represented in the active node as input, and when the packet is retransmitted to another active node it carries information about each node it visits. The result of execution the packet will display
Leaching scheduling techniques are one of the suggested solutions for water scarcity problems .The aim of the study is to show the possibility of using leaching scheduling, when applying the irrigation scheduling program for a certain irrigation project, which was prepare by Water Resources Engineering –University of Baghdad with some modifications to generalized it and it make applicable to various climatic zone and different soil types.
The objectives of this research is to build a system that concerns the prediction of the leaching scheduling (depth and date of leaching water), illustrating the main problems (soil salinity, save the amount of leaching requirement, and to maintain crops growth).The other objective is to compare be
Nowadays power systems are huge networks that consist of electrical energy sources, static and lumped load components, connected over long distances by A.C. transmission lines. Voltage improvement is an important aspect of the power system. If the issue is not dealt with properly, may lead to voltage collapse. In this paper, HVDC links/bipolar connections were inserted in a power system in order to improve the voltage profile. The load flow was simulated by Electrical Transient Analyzer Program (ETAP.16) program in which Newton- Raphson method is used. The load flow simulation studies show a significant enhancement of the power system performance after applying HVDC links on Kurdistan power systems. Th
... Show MoreThe reality of the field of construction projects in Iraq refers to needing for the development of performance in order to improve quality and reduce defects and errors and to control the time and cost, so there is needing for the application of effective methods in this area, one of the methods that can be applied in this area is the manner of Six Sigma. This research aims to enhance the performance and quality improvement for the construction projects by improving performance in the work of the implementation of the concrete structure depending on the Six Sigma methodology, and for the purpose of achieving the aim of the research, the researcher firstly depends on the theoretical study that include the concepts of qual
... Show MoreThe natural ventilation in buildings is one of effective strategies for achieving energy efficiency in buildings by employing methods and ways of passive design, as well as its efficiency in providing high ranges of thermal comfort for occupants in buildings and raises their productivity. Because the concept of natural ventilation for many people confined to achieve through the windows and openings only, become necessary to provide this research to demonstrate the various passive design strategies for natural ventilation. Then, research problem: Insufficient knowledge about the importance and mechanism of the application of passive design strategies for natural ventilation in buildings. The research objective is: Analysis of passive desi
... Show MoreThis 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
Nanocrystalline ZnO/Zeolite type A composite was prepared by simple method of operation by . the precipitation of zinc oxide and loading on zeolite 5A in one step. Characterization was made by X-ray diffraction (XRD), X-ray fluorescence(XRF), N2 adsorption- desorption for BET surface area, and Atomic force microscopy (AFM). Results showed that zinc oxide was loaded on zeolite as noticed by the characteristic peaks and was of nano scale having an average diameter of 88.57nm. The percentage loading of ZnO on zeolite A was 28.37% and the surface area was 222m2/g. The activity of the prepared catalyst was examined in the desulfurization of double hydrogenated diesel fuel. The process was investigated in a
... Show MoreIn this paper, the time-history responses of a square plan two-story reinforced concrete prototype building, considering the elastic and inelastic behavior of the materials, were studied numerically. ABAQUS software was used in three-dimensional (3D) nonlinear dynamic analysis to predict the inelastic response of the buildings. Concrete Damage Plasticity Model (CDPM) has been used to model the inelastic behavior of the reinforced concrete building under seismic excitation. The input data included geometric information, material properties, and the ground motion. The building structure was designed only for gravity load according to ACI 318 with
... Show MoreThe present paper deals with studying the effect of electrical discharge machining (EDM) and shot blast peening parameters on work piece fatigue lives using copper and graphite electrodes. Response surface methodology (RSM) and the design of experiment (DOE) were used to plan and design the experimental work matrices for two EDM groups of experiments using kerosene dielectric alone, while the second was treated by the shot blast peening processes after EDM machining. To verify the experimental results, the analysis of variance (ANOVA) was used to predict the EDM models for high carbon high chromium AISI D2 die steel. The work piece fatigue lives in terms of safety factors after EDM models were developed by FEM using ANSY
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