This review offers an overview of key developments that may assist researchers in improving thermal management strategies for photovoltaic systems across different environmental conditions. It's worth noting that temperature significantly affects the efficiency of photovoltaic systems. As operating temperatures rise, energy production decreases, impacting the system's lifetime. The main focus of this research paper, which examines recent developments in thermal management technologies for photovoltaic systems, is the use of fin-based cooling technologies. he efficiency of passive, active, and hybrid cooling technologies was evaluated, focusing on their ability to dissipate heat and increase the efficiency of photovoltaic
... Show MoreThe effect of the initial pressure upon the laminar flame speed, for a methane-air
mixtures, has been detected paractically, for a wide range of equivalence ratio.
In this work, a measurement system is designed in order to measure the laminar flame
speed using a constant volume method with a thermocouples technique. The laminar
burning velocity is measured, by using the density ratio method.
The comparison of the present work results and the previous ones show good
agreement between them. This indicates that the measurements and the calculations
employed in the present work are successful and precise.
This study's primary emphasis was locating appropriate locations in the valley of Al-Abyadh for water harvesting dams. Water harvesting techniques are one possible answer for Iraq's water difficulties caused by climate change and the existing dams in the high reaches of rivers, which have exposed the world to severe drought. Water harvesting is collecting water from a specific area, beginning with rainwater in the ground and conserving it by building dams to store it. Valley Al-Abyadh, which extends 268 km and has an area of 4188.96 km2, is situated in Anbar Governorate's western desert. Water flows into the Al-Abyadh valley through four basins. This study aims to examine the four basins hydrologically and ana
... Show MoreThe one-dimensional, spherical coordinate, non-linear partial differential equation of transient heat conduction through a hollow spherical thermal insulation material of a thermal conductivity temperature dependent property proposed by an available empirical function is solved analytically using Kirchhoff’s transformation. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner radius with a step change in temperature. Four thermal insulation materials were selected. An identical analytical solution was achieved when comparing the results of temperature distribution with available analytical solution for the same four case studies that assume a constant thermal con
... Show MoreANN modeling is used here to predict missing monthly precipitation data in one station of the eight weather stations network in Sulaimani Governorate. Eight models were developed, one for each station as for prediction. The accuracy of prediction obtain is excellent with correlation coefficients between the predicted and the measured values of monthly precipitation ranged from (90% to 97.2%). The eight ANN models are found after many trials for each station and those with the highest correlation coefficient were selected. All the ANN models are found to have a hyperbolic tangent and identity activation functions for the hidden and output layers respectively, with learning rate of (0.4) and momentum term of (0.9), but with different data
... Show MoreThe present study deals with the removal of dyes from the effluent of the state company for cotton textile industries located at Al-Khadmya by using oven dried alum sludge (ODS) as adsorbent. Two different dyes; Direct black and solar brown are studied. Alum sludge was collected from Al-Qadisiya water treatment plant; it was heated in an oven at 105°C for 24 hours, then cooled at room temperature and crushed to produce particle sizes of 1.18-2.36 and 4-4.75 mm. Batch and fixed bed mode were used. In batch experiments the effect of oven dried alum sludge weight on adsorption process and equilibrium isotherm were studied by using 15-125 g/l of oven dried alum sludge for direct black and 15-175 g/l for solar brown, with constant initial dy
... Show MoreRadiation is the emission of energy in the form of particles or photons, and it has two types: cosmic radiation and terrestrial radiation. Materials that emit radiation as they decay over time are called naturally occurring radioactive elements. This study, which was conducted at the Asalah site after removing radioactive contamination, included taking 15 samples from different locations at the site and conducting radiological tests on them using the HpGe (high-purity germanium) system available at the laboratory of Iraqi Atomic Energy Commission- Radiological and Nuclear Applications and Laboratories Directorate From this study one can see that the average value of specific activity for 226Ra was 15.51 Bq/kg,
... Show MoreStatic behavior of three partially encased composite steel beams with cambering under flexural condition is investigated in the context of studying some alternative positions for the headed studs. Shear resistance between the cambered I-shaped beam and the concrete was provided by headed studs in two positions: vertically welded on the bottom flange and horizontally welded on the faces of the web. In the present study, a nonlinear three-dimensional finite element analysis has been used to predict the load-deflection and moment-rotation behaviors of composite encased beams consisting of steel sections using the finite element computer program (ANSYS V. 10). Composite encased beams are analyzed and a comparison is
made with available ex
Reinforcement of refractory castables with steel fibers improves their strength for cracking and spalling and expands the service life.
The results show that raising the temperature from 700°C to 900°C causes an increase in porosityand decrease in bulk density for refractory castables. This happens because of decomposition of the hydraulic bond of alumina cement. When the temperature is raised higher than 900°C, ceramic bond is formed as a result of sol dreaction between alumina cement and bauxite aggregate. This leads to reduction of the porosity ar d aincrease in the bulk density. Steel fibers are affected positively in reducing the porosity ardaincreasing the bulk density for refractory castables. This positi
... Show MoreNoise levels have rapidly increased in recent years, largely due to the proliferation of modern appliances and critical noise sources like engine exhaust mufflers. Controlling muffler-radiated noise could reduce its impact on the surrounding communities. Generally, conventional mufflers utilize expensive sound-absorbing, fibrous, porous materials with high cost and harmful effects. Thus, eco-friendly materials are being used as alternative materials for their lower cost and less effects. The objective of this study is to evaluate natural material fiber's potential as an effective sound absorber in exhaust absorptive mufflers. Also, evaluate an elliptical muffler's performance by studying several factors, including liner
... Show More.
Water is necessary for sustainable development and healthy society. Groundwater, often, is not sufficient and protected for direct human consumption. Due to increase in the density of population the requirement of water is increasing. In this work, the assessment of groundwater quality was conducted in the south-west part of Basrah province. Spatial variations in the quality of groundwater in the study area have been analyzed utilizing GIS technique. The geochemical parameters of groundwater samples including pH, EC, TDS, Ca, Mg, Na, Cl, HCO3, SO4, and NO3 were assessed in this study. Information maps of the study area have been actually prepared to make use of the GIS spatial
... Show MoreEye loss may be caused as a result of eye trauma, accidents, or malignant tumors, which leads the patient to undergo surgery to remove the damaged parts. This research examines the potential of computer vision represented by Structure from Motion (SfM) photogrammetry in fabricating the orbital prosthesis as a noninvasive and low-cost technique. A low-cost camera was used to collect the data towards extracting the dense 3D data of the patient facial features following Structure from Motion-Multi View Stereo (SfM-MVS) algorithms. To restore the defective orbital, a Reverse Engineering (RE) based approach has been applied using the similarity RE algorithms based on the opposite healthy eye to rehabilitate the defected orbit
... Show MoreShallow and inclined skirted foundations on 30% sandy soil were examined in the experiment program. The study examined the effects of positive and negative eccentric-inclined loading on foundations. Experimental testing was done in a 600 × 600 mm box with a 50 x 50 mm square footing with a 10 mm thickness. The skirt angles were 10°, 20°, and 30°, and the skirt depth was Ds was 0.5 B. Results showed that using skirts significantly increases load-bearing capacity and decreases tilting. Tilting reduces with a skirt, and skirt inclination (alpha) increases with similar loads. Inclined skirts decrease tilt by (2.3% to 0.66%) at e was 0.15 B, load angle (beta) was 15°, and alpha was 30° in the negative case. Tilting incr
... Show Morethe influence of permeability tensor upon drainage of anisotropic soils under ponded water and steady recharge (rainfall) is theoretically investigated. Tensorial permeability has led to the formulation of mixed type partial differential equations. Since there is no analytical solution to this problem, the formulation is therefore solved numerically by the method of finite elements. The finite element formulation is implemented into a computer model which can be applied to any problem of seepage under steady state
conditions. Two different example problems representing two different flow conditions under full anisotropy have been studied. Results of the model for the isotropic case were checked against exact mathematical solutions de
Globally, the focus is on maximizing the energy yield and efficiency of PV systems as an essential renewable energy source. Different methods have been proposed to achieve this goal. Where the sun’s location in the sky is changed during the day, a tracking mechanism has been proposed as a promising technology to harness the maximum amount of solar radiation by PV system as compared to the fixed panels. In this study, the design and implementation of a polar single-axis tracking system is presented to improve the energy efficiency of PV system through angular variation during the day using the proposed tracking system. This is achieved by interconnecting some devices that include GPS sensors and satellite dish actuators
... Show MoreDocument analysis of images snapped by camera is a growing challenge. These photos are often poor-quality compound images, composed of various objects and text; this makes automatic analysis complicated. OCR is one of the image processing techniques which is used to perform automatic identification of texts. Existing image processing techniques need to manage many parameters in order to clearly recognize the text in such pictures. Segmentation is regarded one of these essential parameters. This paper discusses the accuracy of segmentation process and its effect over the recognition process. According to the proposed method, the images were firstly filtered using the wiener filter then the active contour algorithm could b
... Show MoreThis paper describes a stego system in which a gray scale image is embedded in another one.Wavelet transform of both the cover image and the embedded image is used to sort their subbands energies to guarantee that the embedded image will be inserted in the low frequency components of the cover image with little perceptual distortion. Embedding by this way increases the robustness of the system but affects the syster 1 imperceptibility, so a variable scaling factor (a) is used to attenuate the components of the embedded image before adding them to those of the cover image. It is found that the stego image with peak signal-to-noise ratio (PSNR) of about 30 dB has goo 1 imperceptibility.The attacker is proposed to be act
... Show MoreParticulate matter (PM) emitted from diesel engine exhaust have been measured in terms of mass, using
99.98 % pure ethanol blended directly, without additives, with conventional diesel fuel (gas – oil),to
get 10 % , 15 %, 20 % ethanol emulsions . The resulting PM collected has been compared with those
from straight diesel. The engine used is a stationary single cylinder, variable compression ratio Ricardo
E6/US. This engine is fully instrumented and could run as a compression or spark ignition.
Observations showed that particulate matter (PM) emissions decrease with increasing oxygenate
content in the fuel, with some increase of fuel consumption, which is due to the lower heating value of
ethanol. The reduction in
This paper presents region growing image segmentation method which unifies region and boundary information. Several studies shown that segmentation based on image features can improve the accuracy of the interpretation. The goal of segmentation is to simplify and/or change the representation of an image into something that is more meaningful and easier to analyze. Image segmentation is typically used to locate objects and boundaries (lines, curves, etc.) in images. More precisely, image segmentation is the process of assigning a label to every pixel in an image such that pixels with the same label share certain visual characteristics.
A problem that frequently arises when an image is segmented is that the number of feature variables o
In this paper, split-plate airlift electrochemical reactor as an apparatus with new configuration for wastewater treatment was provided. Two aluminum plates were fixed inside the reactor and present two functions; first it works as split plates for internal loop generation of the airlift system (the zone between the two plates acts as riser while the other two zones act as downcomer) and second it works as two electrodes for electrocoagulation process. Simulated wastewater contaminated with zinc ions was used to test the performance of this apparatus for zinc removal by studying the effect of different experimental variables such as initial concentration of zinc (50-800 ppm), electrical current density (2.67-21.4 mA/cm2), init
... Show MoreThe investigation-included experiments were conducted to investigate the local and average mixed
convection heat transfer coefficient for thermally developing and fully developed hydrodynamically laminar airflow in an inclined annulus. The experimental setup, using an aluminum annulus having a radius ratio of (0.41) and the inner tube with a heated length of (0.85m) with constant wall heat flux boundary conditions. The investigation covered Reynolds number range from (332 to 1128) and heat flux varied from (82w/m² to 545w/m2). The air is developed hydrodynamically by using the entrance section annulus (calming section) having the same inner and outer diameter as a test section but with variable lengths. The entrance sections inc
... Show MoreArchitecture forms theoretical summaries and multi systems that have the essence of change, and that what distinguishes Architecture from other sciences and their systems. Architecture means way of life via its expressional products and that appears through its systems. These systems are based on formative and technological properties in form, structure, services and materials as well as
their moral forms. All these are associated with techniques and facilities in order to establish integrated system.
Architectural creation does not come from void but it depends on a conception base to create a new condition for creative architectural product. The general problem of the research concentrated on limited theoretical and practica
Quadrotors are coming up as an attractive platform for unmanned aerial vehicle (UAV) research, due to the simplicity of their structure and maintenance, their ability to hover, and their vertical take-off and landing (VTOL) capability. With the vast advancements in small-size sensors, actuators, and processors, researchers are now focusing on developing mini UAV’s to be used in both research and commercial applications. This work presents a detailed mathematical nonlinear dynamic model of the quadrotor which is formulated using the Newton-Euler method. Although the quadrotor is a 6 DOF under-actuated system, the derived rotational subsystem is fully actuated, while the translational subsystem is under-actuated. The der
... Show MoreGiven the pivotal role that roads play in a nation's development, their construction often entails significant risks and challenges. Therefore, road construction projects must be successfully implemented. Numerous studies have been conducted to discover the key factors affecting road construction projects and their improvement. The aim of this study was to examine and pre-determine the factors affecting the success of road construction. Data was collected from experts in the field of road management to identify the factors influencing road construction projects in Iraq. Data was also used from interviews with road construction project managers. After analyzing this data, the study concluded that there are several externa
... Show Moreظهر مفهوم التآزر الحضري كرد فعل لما تواجه مراكز المدن الحضرية في ظل التطور الحضري السريع والتحديات المعاصرة والتغيرات المستمرة للمدن من أهمها، إفتقاد مراكزها الحضرية لمعالمها المحددة التي كانت تضفي عليها المعنى الخاص بها كعنصر عمراني حيوي وعلاقة المفهوم بصناعة المكان. وبذلك تحددت مشكلة البحث بنقص المعرفة حول التنوع الوظيفي للتآزر الحضري وعلاقته بصناعة المكان الابداعي في المراكز الحضرية وفق رؤية معاصرة
... Show MoreSustainability means, the integration between the ecological, technological, economical and social systems to forming the urban environment to maintain the resources for the future generations. Sustainability focuses on many principles: Using the natural energy, learning from the traditional architecture, minimizing the consumption of the resources.To develop some criteria's for contemporary dwellings in hot dry climate, the research tried to study and analyze the traditional architecture to diagnose its importance and ability to solve contemporary problems, one of which is the lack of comfortable and suitable dwelling units in hot dry climate regions.The research will study the traditional urban fabric components in the hot- arid zone,
... Show Moreيعد التنبؤ بالنفاذية أمرًا بالغ الأهمية في توصيف المكمن لبناء نماذج مكمن ثلاثية الأبعاد. المكمن الثلاثي لحقل عجيل النفطي عبارة عن مكمن كربونات معقد يتكون من تكوينات جيولوجية متعددة الطبقات وأنواع صخرية مختلفة. يمثل فهم سلوك تدفق السوائل في المكمن الثلاثي تحديات كبيرة. في هذا البحث يتم دمج أنواع الصخور عن طريق تقنيات التحليل العنقودي مع طريقة مؤشر منطقة التدفق (FZI) لتصنيف المكامن إلى وحدات تدفق هيدروليكي في
... Show MoreFirstly, in this study, a brief updated description and applications of different solar collectors used in renewable energy systems for supplying electric and thermal energy was presented. Secondly, an attempt was made to utilize tilting orientation of solar collector for maximizing collector energy with time in respect to horizontal orientation. For energy calculation, global solar radiation was used since they are directly related. For that purpose, field measurements of half-hourly radiation on two flat panels of tilting and horizontal orientations were carried out throughout 8-month period under local climate of Baghdad. Then, energy gain and radiation level averages were calculated based on the field radiation
... Show MoreMaximum power point tracking (MPPT) is used in photovoltaic (PV) systems to enhance efficiency and maximize the output power of PV module, regardless the variation of temperature, irradiation, and the electrical characteristics of the load. A new MPPT system has been presented in this research, consisting of a synchronous DC-DC step-down Buck converter controlled by an Arduino microcontroller based unit. The MPPT process with Perturb and Observe method is performed with a DC-DC converter circuit to overcome the problem of voltage mismatch between the PV modules and the loads. The proposing system has high efficiency, lower cost and can be easily modified to handle more energy sources. The test results indicate that the u
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