DIYALA JOURNAL OF ENGINEERING SCIENCES

This research has been done to study and diagnose operational factors and conditions affecting the zinc powder specification and efficient performance of the electrochemical process .The selection of the optimal conditions for the powder preparation at an average particle size up to 100 μm will be investigated with high productivity and efficiency. The results indicated that the adoption of electrochemical technique was suitable for obtaining zinc powder at average particle size less than of 100μm directly by 77.8% of the total amount prepared, purity of 99.2% and current efficiency (64.9%). The optimal conditions were through using an electrode cathode of stainless steel, zinc as an anode in alkaline medium of sodium hydroxide (200 g/l), zinc ions concentration up to (6 g/l), current density 0.19 amp/cm2on the cathode electrode, and electrochemical deposition time of (2 hrs.). Also empirical relations obtained by correlating the effective parameters using non-linear regression with correlation coefficients (0.97 and0.92) and the relation s are: Current efficiency (Y1) = -884.65-2.5 X1 -1351.2 X1X2 + 55.62 X1X3 -0.04 X12 +12945.18 X2-1715.78 X2X3+.2.888X22-0.96X3 -0.39X32, R= 0. 97Productivity (Y2) = 6225.1 + 174.3 X1 + 3442.8 X1X2 -196.6 X1X3-58189.7 X2 + 12689.7 X2X3-1704.0 X22-1224.7 X3 -2.4 X32, R= 0.92

This study aims to show the effect of specimen size and shape on compressive strength of self-compacting concrete (SCC). The work is divided into two parts, the first was to designed Normal Concrete (NC), High Strength Concrete (HSC) and Self Compacting Concrete (SCC) of strength between (25-70)MPa. from locally available materials. The values percent of cylinder to cube strength were between (0.86-0.9), (0.94-0.96), (0.96-0.99) of NC, HSC and SCC respectively .The second is to investigate the effect of specimen size on compressive strength, the values of correction factor of cube specimens (150*150*150)mm and (100*100*100)mm is (0.89-1.29), (0.98-1.26) and (0.98-1.22) of NC,HSC and SCC respectively. The values of correction factor of cylinder specimens of (150*300) mm and (100*200) mm is (0.88-1.08), (0.93-1.07) and (0.95-1.04) of NC, HSC and SCC respectively.

Calcareous or salty soils are the soils which are containing highly dissolved sodium or calcium salts in natural conditions. The dissolution of salts increases with temperature, atmospheric pressure, in addition to the acidity of the dissolves solution. Calcareous soil is stiff and very hard if it is in a dry phase; it becomes collapsible and very week when wetted with water. It is very dangerous for structures when constructing on such soil especially when high stresses are applied on it. Oil tanks or pipes may damage from any reason, and the oil products may leak from these structures to the soil and infiltrate through soil skeleton and may cause leaching to CaCO3salt particles in some regions in Iraq, as example the Baiji Oil Station or Al-Mosel Dam, CaCO3percent reaches more than 40%.This study shines the lights about the behavior of Calcareous soil subjected to three oil derivatives (kerosene oil, crude oil, gas oil and a sample wetted with water to make good comparison ,and study effect of addition of this products on the collapsibility.A laboratory model included soil with 70% and 50% CaCO3compacted to 11 kN/m3. Fix stress system was used which applies 50 kN/m2, the loading frame was manufactured in a way that keeping the weights over footing stable without tilting. Three oil derivatives (Kerosene, Gasoil and crude oil) were used for laboratory model tests; by wetting Calcareous soil with it. One sample was wetted with water for comparison; the settlement was recorded with soaking time at a constant stress level .The results of laboratory model tests shows that the settlements results from specimens soaked with lubricating oil, Gasoil and Kerosene, are much less than the settlements that belong to soaking with water (reduce settlement to about one third) and considered high improvement of such problematic soil by wetting with oil derivatives

A domestic refrigerator of 5 ft3capacity is used to study the effect of coiled diameter and pitch distance of a capillary tube.Five capillary tubes of 2 mm in diameter and 1500 mm length each are used, as same as original capillary tube of the refrigerator. The capillary tubes is formed in five shapes, each one has different coil diameter (D) namely 25, 50, 75, 100 and 125 mm in diameter, in addition three distances between each coil (pitch (P)) is tested, namely 6, 8 and 10 mm. The pressure at inlet and outlet of capillary are measured to calculate the cycle COP, as well as the power consumed by the cycle compressor is measured to calculate the mass flow rate of refrigerant. The work show that the coiled diameter of capillary tube affect the cycle COP strongly, as the capillary coiled diameter (D)increases from 25 to 100 mm the cycle COP increases from 2.8 to 3.7 when the cabinettemperature equals to 8oC. The increases of coiled diameter more than 100 mm shows insignificant effect on the cycle COP. While the pitch space of capillary tube coiled shows minor effect on the cycle COP. Moreover, to the mass flow rate of refrigerant increases with approximately ranges from 1.2−2.7????????⁄as the capillary coiled diameter increases from 25 to 125 mm when the cabinet temperature equals to 8o C. Also; there are directly proportional between the temperature of evaporator cabinet from 2-8o C with mass flow rate of refrigerant from 1.9-2.4????????⁄when capillary coiled diameter 100 mm

The scour at downstream of hydraulic structures is one of the major concern in its stability analysis and operation .The excess energy existing immediately downstream of such structures has to be controlled .Hence, it is necessary to design and install a device for dissipating excess energy in order to prevent downstream scour. The drop structuresis one of the commonly structures used for dissipating excess energy.In the present study an experimental approachis employed through which differenttypes of stilling basin with different heightswere tested using one drop and two consecutive drops. Moreover the effect of the end sill and baffles with different heights and different bed slopes wasinvestigated. The hydraulic parameters involved were measured experimentally using a model of straight drop installed in the available (S6) multi-purpose flume in the fluid mechanics lab at the Civil Engineering Department, University of Garyounis.Results showed that, for one drop the presence of end sill reduced the length of the jump by a small value approximately 4%with an increase of relative energy loss by a small value. The increase of relative baffles block height increases the optimum relative height of drop (w/y1=6), and the relative energy loss .For two consecutive drops it was found that the most value of energy loss takes place in the second basin .The presences of end sill at the end of second basin increases the performance of second basin by small value approximately 5%. It is also shown that increasing the relative height of baffles blocks lead to increases in the relative energy loss (within the ranges considered in this study), and the optimum relative baffle block height hb/y1=0.77 to 1.7 and bed slope is 1/50

This paper presents a numerical analysis of new airfoil, TCB6612, and compared with respect to standard airfoil NACA4412 using them in wind turbine blade. The main objective of this work is to enhance the aerodynamic performance of airfoil by changing the geometry of the airfoil in order to increase the overall power output of the wind turbine. Two software, GAMBIT and FLUENT, are used in this work; GAMBIT is used to create modeling and meshing of the airfoils while FLUENT is used to simulate and analysis the airfoils. The analysis showed that the significant enhancement in aerodynamic performance for TCB6612 is occurred. It is found that value of Cd/Clis decreased about 10.23%, the power coefficient is reached to 51.9%,and the power output is increased about 9.8%

After the success of various international experiments of adopting preventive conservation approaches for safeguarding the cultural heritage such as Monumentenwacht Vlaanderenin Belgium, and Netherlands, and Laconsrvazione programmata in Italy, many countries attempt to put such strategies for protecting their heritage. During the last three decades or less, many monuments and heritage buildings in Mosul old city have been deteriorated progressively due to many factors the most important of which is the lack of monitoring and controlling procedures for preserving these irreplaceable outstanding constructions. Preventive conservation describes research and interventions aiming at reducing deterioration rates and minimizing risks to the constructions. It aims to identify and reduce potential hazards to cultural artifactswith thoughtful control of their surroundings, and it attempts to mitigate the occurrence of damage and deterioration through research and the implementation of procedures which enhance the safety of cultural objects and buildings. The absence of a comprehensible and efficient preservation protective policy for the responsible institutions of conservation of Mosul built heritage is a critical issue. The research aims to compare the current conservation policy of these institutions with international counterparts, and to put guidelines and recommendations for preparing a preventive conservation plan for the cultural heritage of Mosul Old City, which are represented by controlling its vital aspects such as managing of environment, risk, documentation, schedule investigation, information, regulation, human resources, and communication. The paper methodology adopts a comparative analytical study between several successful international experiments in preventive conservation field and the current existing procedures of the conservation of the Mosul built heritage

Furnace brazing was carried out to produce joints between two different materials, Oxygen Free High Conductivity Copper [OFHC] type ISO C10300 and silicon steel (electric steel) type ASTM 36F145 by using two groups of filler metals were selected in thisresearch, silver grouptypeDIN L-Ag20Cd and copper grouptypeAWS BCuP-1 with usingflux type AWS FB3-A to remove oxide and protect the welding joint.The brazing temperature for both filler was 790°C and 940°C respectively above liquidus temperature of them,then soaking at different time (10, 20,30,40,50,and 60min.) for each filler metal. The microstructures of cross section area of joints were revealed in optical microscope shows presence of different reaction in the brazed area. The maximum double shear strength of dissimilar brazed joints was 47MPa by using filler metalAWS BCuP-1at 30min. soaking time, while using filler metal DIN L-Ag20Cd give rice in double shear strength to 98MPa at 30min. soaking time due to better coalescence of the mating surfaces .The occurrence of solid solution and different types of intermetallic compounds such as Cu5Si, Fe3Zn10, FeZn10, Cu5Zn6, CuZn, CdCu2, Cd3Cd4, Cd3Cu, Cu3P,and α-Fe that is responsible for joint strength has been detected by X-ray diffraction inspection

The alcohol–gasoline blend fuels nowadays areincreasingly used instead of gasoline in automobiles. In the present study, the temperature distribution within the cylinder of Suzuki250Gsx motor was studied, taking in account the use of gasoline, E10-gasoline and E20-gasoline blends as a fuel, separately. The temperature fields are calculated using ANSYS 11 software. The geometric model and dimensions of the cylinder was established using Solid work 2003 program then imported by ANSYS11. After applying the boundary conditions and taking the assumptionsin account, the results illustrated that the interchange of gasoline by E10-gasoline and or E20-gasoline blends has a variety of thermal load on the cylinder. Where the temperature distributed decreasingly towards the axial and radial directions. In addition, the engine becomes colder as the ethanol percentage in the fuel been 20%. This may provide supporting information for new designs for using E10-gasoline and or E20-gasoline blends on SI engines so that not to effect the engine operation and lubricating oil performance

في هذه الدراسة تم تحضير عدة عينات من سبائك الألمنيوم –نحاس حيث أضيفت كميات من النحاس إلى الألمنيوم النقي بنسبة 05.2, 15.2, 45.2بحيث لاتتعدى حد التشبع للألمنيوم وهي .512نحاس لغرض تقسية الألمنيوم وقد تم تحضير هذه السبائك الثلاثة بعملية الصهر والصب في قوالب من الفولاذ. يهدف البحث الحالي الى دراسة تأثير أضافة النحاس على الخواص الميكانيكية ومقاومة البلى ألانزلاقي الجاف للألمنيوم النقي.استخدمت ماكنة المسمار على القرص الدوار لقياس معدل البلى وتحت ظروف مختبريه متغيرة تمثلت باستخدام خمسة أحمال عمودية مختلفة وخمسة سرع انزلاقية مختلفة ولفترات انزلاق تراوحت من(12) الى(092) دقيقة وعند درجة حرارة الغرفة وصلادة القرص الفولاذي 4.HRC. وقد أظهرتالنتائج إن معدل البلى يزداد مع زيادة الحمل العمودي المسلط على عينات الاختبار والفترة الزمنية للانزلاقلجميع العينات. كما وأظهرت سبيكة Al-15.2Cuأفضل مقاومة بلى عند مقارنتها مع السبائكAl-45.2Cu وAl-.05.2Cu وكذلك بينت النتائجبأن مقاومة البلى للسبائك الثلاثة كانت أفضلمن مقاومة المعدن لأساس

The aim of designing any building or space is to make optimum use of the building or space, and to avoid using problems after design and implementation processes. So, it is necessary to provide studies on the use of different spaces. From the important spaces that shall be studied is university space, due to the close link between university and community.The internal spaces of university buildings are considered to be one of the most important spaces in university systems. They play an important role at containing basic activities for the university systems, such us (educational, administrative, and service activities). Hence, is the importance of the study of spaces and space relations, but space relations cannot be studied without returning to the basic components of the urban environment in the city, which is a system composed of space, mass, movement, and activities as expressed by (Spreirgen), that will be addressed in the research through the study of space-mass relationship, and within this aspect is the pattern of spatial relationships between university buildings and surrounding spaces. From this there search problem can be determined by existenceofvariation about the interpretation -The effect of the space relations on the streamline movement in the university buildings .The researchaimstostudythespacerelationsinmorefocusedway through the concept ofmass andspace, and studying the streamline movementthrough the study existing movement patternsin the university. The practicalpartincludes analysis thestreamlined buildingsin the Sulayman University ,according to asetofindicatorsof movement patterns. Then through it, the researcher reached asetofconclusionsand recommendations

This research will handle the importance of conserving construction materials, identifying the causes of waste, and limiting the waste, moreover recommending the optimal use of these materials, (1)With the aid of a survey that was carried out in Sulaymaniya governorate which included 13construction companies, the statistics were prepared through which the causes of waste in construction in these companies were studied, finally, the researchers based on the these information, arrived to their conclusions about the issue of waste,concluding that the main causes of this issue is due to managerial and organizational misconceptions, such as that of unsuitability of the construction site as well as contract based errorsand made their recommendations in order to minimize and eliminate these causes as much as possible