An experimental and numerical study has been carried out to investigate the heat transfer by natural convection in air-filled annulus between two horizontal isothermal concentric cylinders with and without annular fins under steady state conditions; the inner cylinder surface is maintained at a higher temperature and the outer cylinder surface at a lower one. In the experimental study, the annulus inner surface is maintained at high temperature by applying uniform heat flux to the inner cylinder while the annulus outer surface is subjected to ambient temperature and maintained at low temperature. The experiments were curried out at a range of Rayleigh number (1.81×103 – 4.03×104) for case without fins and (1.08×103 – 2.94×104) fo

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

With 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

Recently, some of Iraq's newly constructed asphalt concrete pavements showed premature failures with significant negative impacts on roadway safety and the economy. Using Nano hydrated lime (NHL) in pavement construction could be one of the possible steps to improve pavement durability. This article discusses how NHL affects the durability of hot mix asphalt. NHL was added in two methods to the asphalt concrete mixture for the wearing course. The first is the dry method, i.e., on the aggregate, whereas the second is the wet addition method, i.e., to the bitumen. The percentages were tried for each additional method; 1, 2, and 3% by weight of aggregate for the dry method and 0.5, 1, and 1.5% by weight of asphalt concrete

Transit agencies constantly need information about system operations and passengers to support their regular scheduling and operation planning processes. The lack of these processes and cultural motivations to use public transportations contributes enormously to the reliance on the private cars rather than public transportation, resulting in traffic congestions. The traffic congestions occur mainly during peak hours and the accidents happening as a result of road accidents and construction works.  This study investigates the effects of weekday and weekend travel variability on peak hours of the passenger flow distribution on bus lines, which can effectively reflect the degree of traffic congestion. A study of passen

This search concerns study the crack growth in the wall of pipes made of low carbon steel under the impact load and using the effect of moisture (rate of moisture 50%). The environmental conditions were controlled using high accuracy digital control with sensors. The pipe has a crack already. The test was performed and on two type of specimens, one has a length of 100cm and other have length 50cm. The results were, when the humidity was applied to the pipe, the crack would enhance to grow (i.e. the number of cycles needed to grow the crack will reduce). In addition, when the test performed on the specimens of length 50cm the number of cycles needed to grow the crack is increased due to the effect of bending stress on the

To study the nonlinear response of composite concrete beams, a finite element analysis is presented. Material nonlinearities as a result of nonlinear response of concrete in compression, crushing and cracking of concrete, strain softening and stiffening after cracking, yielding of reinforcement, bond- slip, shear-slip, and dowel action between the precast concrete beams and the cast-in-situ slabs are considered.A biaxial concrete model is adopted. Concrete is treated as an orthotropic material with smeared rotating crack model. The steel reinforcement is assumed to be in a uniaxial stress state and is modeled as a bilinear material. I A two-dimensional plane stress finite element type is used to model the concrete Reinforcement is repres

A total of 48 experiments were conducted to investigate the impact of slit weir dimensions and locations on the maximum scour depth and scour area created upstream. The slit weir model was a 110 mm slit opening, and it was installed at the end of the working section in a laboratory flume. The flume was 10.0 m long, 30 cm wide, 30 cm deep, and almost middle. It includes a 2 m working section with a mobile bed with 110 mm in thickness. In the mobile bed, two types of nonuniform sand (with a geometric standard deviation of 1.58 and 1.6) were tested separately. The weir dimensions and location were changed with flow rates. Then dimensions of the slit weir were changed from 60 x 110 mm to 60 x 70 mm (width x height), while th

Undoubtedly, Road Traffic Accidents (RTAs) are a major dilemma in term of mortality and morbidity facing the road users as well as the traffic and road authorities. Since 2002, the population in Iraq has increased by 49 percent and the number of vehicles by three folds. Consequently, these increases were unfortunately combined with rising the RTAs number, mortality and morbidity. Alongside the humanitarian tragedies, every year, there are considerable economic losses in Iraq lost due to the epidemic of RTAs. Given the necessity of understanding the contributory factors related to RTAs for the implementation by traffic and road authorities to improve the road safety, the necessity have been a rise for

Porcelanite rocks were selected to be the dual media with sand in this study to improve the performance of the filtration process in water treatment plants. The work required installing a pilot filtration unit in the location of the filters in one of the water treatment plants, so the experimental work was performed on the same influent water of the filters in the plant (the effluent from the sedimentation tank. The pilot filtration consists of three plastic column filters, working parallel and simultaneously. The first contains 70 cm sand (the same type used in the filters of the plant), the second and third were dual filters (porcelanite with sand) of different depths and sizes using different filtration rates (5, 10, and 15 m/hr). The

The work in this research presents an experimental and a theoretical study to obtain the effect of using a low permeability geosynthetic material on the longitudinal and lateral coefficients of dispersion. This would have its effect on the contaminants migration through an isotropic, homogenous and saturated soil. The first stage of this research involves the study of the geosynthetic material and in calculating the longitudinal and lateral coefficients of dispersion for an Iraqi sandy soil by using an experimental set-up to simulate the processes. To investigate the effect of using a geosynethtic material on the dispersion coefficients, the test was conducted for each velocity that was used in the experimental work and as follows: wi

Methyle tertiary-butyl ether (MTBE) is the most fuel additive used through the world.Thus, it has been reported that MTBE is the second high concentration contamination found in ground water.
Study of the effect of reaction time and reaction temperature of 25 to 55° C on the kinetic of chemical oxidation has been done with 3000 ppm MTBE in water at pH range 3 to 7 and 1:1 hydrogen peroxide to Fenton’s reagent ratio.
Also, Kinetic analysis was carried out to determine reaction order and activation energy for the reaction of MTBE disappearance during the reaction with Fenton’s reagent.

The present research is concerned with studying of the drag force on two spheres moving side by side and in line in non-Newtonian liquid. Polyacryamide (PAA) solution with different concentrations (0.01, 0.03, 0.05 and 0.07)% by weight and water is used for comparison for obtaining the effect of fluid properties on the drag force. Different types of spheres stainless steel, glass and plastic with different sizes and densities were used. Within the considered range of power law index (0.6 - 1), and generated Reynolds number (1.1 -75) in power law fluid and Reynolds number (100 - 1000) for water it was found the drag coefficient increases with increasing the power law index for constant generated Reynolds number and the drag force increase

Due to the deterioration of water quality within the last few years because of the increase of water consumption and the waste water production and disposal into the river The water quality in both surface and ground water resources was negatively affected .The concept of water quality index is used as a tool for water quality classification in Tigris River within Baghdad City .Twenty two parameters of pollution were selected to measure the water quality indices of Tigris river within Baghdad city .Those parameters were measured during (2000-2004)as average monthly values ,three water treatment plants were selected out of the eight water
treatment plants that exist along the river.Al Kharkh water treatment plant to reflect the water

A laboratory-scale experiment was carried out to estimate the influence of temperature fluctuation on thermophilic anaerobic digestion of municipal organic waste (MOW). Heating failure was simulated by decreasing temperature gradually from 55 °C to 20 °C gradually 2 h time need for temperature decrease and recovery. Under conditions of 8.0 g/ (L·d) and 15 d respectively for MOW load and retention time. Following results were found: (1) biogas production almost stopped and VFA (Volatile Fatty Acid) accumulated rapidly when accompanied by pH decrease. (2) With low temperature (20°C) duration of 1, 5, 12 and 24 h, the thermophilic anaerobic digestion system reproduce methane after temperature fluctuation of 3, 11, 56 and 72 h. (3) The b

In this paper three techniques for image compression are implemented. The proposed techniques consist of three dimension (3-D) two level discrete wavelet transform (DWT), 3-D two level discrete multi-wavelet transform (DMWT) and 3-D two level hybrid (wavelet-multiwavelet transform) technique. Daubechies and Haar are used in discrete wavelet transform and Critically Sampled preprocessing is used in discrete multi-wavelet transform. The aim is to maintain to increase the compression ratio (CR) with respect to increase the level of the transformation in case of 3-D transformation, so, the compression ratio is measured for each level. To get a good compression, the image data properties, were measured, such as, image entropy (He), percent r

The differential protection of power transformers appears to be more difficult than any type of protection for any other part or element in a power system. Such difficulties arise from the existence of the magnetizing inrush phenomenon. Therefore, it is necessary to recognize between inrush current and the current arise from internal faults. In this paper, two approaches based on wavelet packet transform (WPT) and S-transform (ST) are applied to recognize different types of currents following in the transformer. In WPT approach, the selection of optimal mother wavelet and the optimal number of resolution is carried out using minimum description length (MDL) criteria before taking the decision for the extraction features from the WPT tree

The political situation experienced by Iraq before the events of 2003 that led to the collapse of infrastructure. rebuilding costs were estimated after 2003 by187(million USD) according to the estimates of the basic needs as stated in Five-Year Plan 2010-2014. The difficult in financing projects and the continuous demands for maintenance and operating cost, and working by contemporary styles in different countries, the strategic option is to adopt the government entering the private sector as a partner in the development process. Since public _private partnership (PPP's) is at a germinating stage of development in Iraq, it has been studied the critical success factors(CSF's) in the experiences of countries that have implemented the style

باتت الجسور في السنوات الأخيرة من أصعب الإنجازات وأكثرها دقة من حيث التصميم ، يستخدمها المارة للعبور اوللاستمتاع
بالمناظر المحيطة، بعضها اكتسبت أهميتها من تاريخها العريق وبعضها من التحول الذي ادخله تشيدها الى منطقة معينة ، والبعض
الأخر من التقنيات التكنولوجية العالية التي تحملها ، حيث أصبحت رمزا للتطور والتقنية التي تتمتع بها منطقة معينة، وقد ساعدت
انظمتها المنشئية في تحقيق التواصل وسمحت لهذه المنش

شهدت العمارة الرافدينية منذ بداياتها الاولى في حضارات وادي الرافدين المتعاقبة مرورا بالحضارة الاسلامية وحتى مطلع
القرن العشرين سلسلة من الطرز المعمارية المتعددة خصها الباحثون والاثاريون والمؤرخون بدراسات وفيرة سواء على
مستوى الحقب التاريخية او على مستوى الانماط الوظيفية او الطرز المعمارية وحتى على مستوى العناصر المكونة لتلك
الطرز.
لكن يمكن تشخيص المشكلة البحثية محدودية في الدراسات التي ترصد الع

Exposure of reinforced concrete buildings to an accidental fire may result in cracking and loss in the bearing capacity of their major components, columns, beams, and slabs. It is a challenge for structural engineers to develop efficient retrofitting techniques that enable RC slabs to restore their structural integrity, after being exposed to intense fires for a long period of time. Experimental
investigation was carried out on twenty one slab specimens made of self compacting concrete, eighteen of them are retrofitted with CFRP sheets after burning and loading till failure while three of them (which represent control specimens) are retrofitted with CFRP sheet after loading till failure without burning. All slabs had been tested in a

An energy and exergy thermodynamic analysis using EES program was done for a domestic refrigerator working with R-134a using vapor compression refrigeration cycle. The analysis deals with the system component, i.e. compressor, condenser, evaporator and the expansion device. The analysis depends on the entropy generation minimization approach to improve the refrigerator performance by exploring the optimum design points. These design points were derived from three different theories governing the entropy generation minimization using exergy analyzing method. These theories were first applied to find the optimum balance between the hot inner condenser area and the cold inner evaporator area of the refrigerator and between

Since no in situ studies exist for determining unsaturated hydraulic characteristics of Iraqi soils
during 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 Profile
Method(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 f

ABSTRACT  
     The simulation of groundwater movement has been carried out by using MODFLOW model
in order to show the impact of change of water surface elevation of the Tigris river on layers of
the aquifer system for Nuclear Research Center at Al-Tuwaitha area, in addition to evaluate the
ability of the proposed pumping well to collect groundwater and change the direction of flow at
steady-state. The results of the study indicated that there is a good match between the values of
groundwater levels that calculated in the model and measured in the field, where mean error  is
0.09 m.
     The study also showed that the increasing of water surface elevation of the

The simulation have been made for  3D flow structure and heat  transfer with and without

longitudinal riblet upstream of leading edge vane endwall junction of first stage nozzle guide vane .The research explores concept of weakening the secondary flows and reducing their harmful effects.Numerical investigation involved examination of the secondary flows ,velocity and heat transfer rates by solving the governing equations (continuity, Navier -stokes and energy equations ) using the known package FLUENT version (12.1).The governing equations were solved for three dimentional, turbulent flowe, incompressible with an appropriate turbulent model (k-ω,SST) .The numerical solution was carried out for 25 mode

The Al Mishraq site has been the subject of many scientific studies for the period before and
after the fire in 2003. Five visits to the site were conducted twice in 2003 for general fact-finding, twice
in 2004, and once in 2005 for detailed sampling and monitoring. Desk-based research and laboratory analysis of soil and water samples results indicate that surface water and groundwater pollution from Al Mishraq site was significant at the time of its operation. The primary pollution source was the superheated water injection process, while the principal receptor is the River Tigris. Now that the plant is idle, this source is absent. Following the June 2003 sulphur fire, initial investigations indicate that short damage to
vegeta

Mixed convection heat transfer in a vertical concentric annulus packed with a metallic porous media and heated at a constant heat flux is experimentally investigated with water as the working fluid. A series of experiments have been carried out with a Rayleigh number range from Ra=122418.92 to 372579.31 and Reynolds number that based on the particles diameter of Re_d=14.62, 19.48 and 24.36. Under steady state condition, the measured data were collected and analyzed. Results show that the wall surface temperatures are affected by the imposed heat flux variation and Reynolds number variation. The variation of the local heat transfer coefficient and the mean Nusselt number are presented and analyzed. An empirical

The surface roughness of the machined parts is the most important parameter to predict the performance of mechanical components. Moreover, predicting the optimal machining parameters conditions is the preferable method for cost reduction and achieving the desired surface quality of the product. This study investigates three cutting parameters, such as depth of cut, spindle speed, and feed for the milling aluminium alloy AA6061, to predict the surface roughness quality. The experimental work utilized a manual milling machine with a coated carbide cutter. Furthermore, the experiments were arranged using the Taguchi L₉ orthogonal array (OA) method. The average surface roughness (Ra) was measured and converted to

An experimental investigation was conducted to study the various parameters affecting the production of oxalic acid by the action of concentrated nitric acid on carbohydrates. Two feedstocks were studied, viz., dates fruit and dates syrup. The study also covered the effect of the amount of nitric acid and catalyst used in addition to employing two acid concentrations (67 wt.% and 98 wt.% acid). The results showed that when using 67 wt.% nitric acid, dates syrup was best suited as a raw material. And the best amount of nitric acid and V₂O, catalyst were in the ratio of 150 mls: 25 mg per 50 g feedstock. When using 98 wt.% nitric acid, no catalyst was required for the reaction and the reaction proceeded violently with the evolu

This research studying the electromagnetic behavior of the induction furnace when its core is a magnetic material taking into consideration the effect of the non-linear dependence of the magnetic flux induced in it due to the applied magnetizing force. Since the magnetic characteristics are severely affected by temperature rise in a non-linear way, so as the specific electric resistance of the charge material, this work deals with studying the effect of temperature on the non-linear characteristics of a magnetic core simultaneously with that on the specific electric resistance to show the electromagnetic behavior of the furnace during heating operation. The distribution of the current density, flux density and the magnetizing force at di