Journal of University of Babylon

The paper gives an experimental study on the performance on the wind turbine rotors with several ‎numbers of blades as well as twist angle. The main goal of this study is to demonstrate the effect ‎blades number, tip angles as well as the twist angle of the blades on the power coefficient (Cp) of the ‎rotor. Moreover, this result represents a simple evaluation about the range of depending power ‎coefficient on the average wind speed.‎
Also, this paper studies the performance of wind turbines which are tested by carrying out 2-‎dimensional dynamic using ANSYS-Fluent.‎

The design of high entropy alloys (HEAs) is a paradigmatic shift in the development and design ‎of novel alloys with novel properties unmatched by conventional alloys. Due to their superior ‎properties, HEAs are promising candidates for use in wide range of new engineering applications. This ‎paper briefly review the metallurgical nature of (HEAs), including novel properties, areas of ‎application; and influence of alloying elements on HEAs. It can be divided into five main sections. ‎The first section focuses on HEAs, identifying and discussing metallurgical nature of HEAs. This ‎section is followed by detailed reviews on novel properties of HEAs. Areas of applications of HEAs ‎discussed in the third section. The fourth section review the influence of alloying elements on the ‎microstructure and mechanical properties of HEAs. Finally, the metallurgical nature of HEAs and its ‎properties, applications, and influence of alloying elements is concluded. Summarizing the findings ‎from literature. ‎

This present experimental work investigates the influence of nanoparticles added to ‎biodiesel blend on the engine performance and emission characteristics. The nanofuel is ‎prepared by adding the aluminum oxide (Al2O3) nanoparticle to biodiesel – diesel blend and ‎compared with pure diesel and biodiesel –diesel blend. The effect of 25 ppm , 50 ppm , ‎and 100 ppm of aluminum oxide( Al2O3) nanoparticles with size 25 nm , added to ‎biodiesel blend are experimentally investigated in a diesel engine type( FIAT), four ‎cylinder ,direct injection (DI), water cooled , and compression ratio 17 :1. with variable ‎engine speed and load . The aluminum oxide was mixed with (BIO20%+DIESEL 80%) ‎B20 fuel blend by the aid of ultrasonicator technique. The nanoparticles adding to B20 ‎improved and increased the physical properties of nanofeul such as cetane number , ‎calorific value , density , flash and fire point and viscosity. Improvement in engine ‎performance is very clear with nanoparticles additives, the specific fuel consumption ‎decreases by 15.5% for 25 ppm, 10.4% for 50 ppm and 6.13% for 100 ppm as compared ‎with neat B20 at full load and all operation condition. The brake thermal efficiency ‎increased by 20.8% for 25 ppm, 17.4 % for 50 ppm and 4% for 100 ppm as compared with ‎neat B20 at full load and all operation condition. The exhaust temperature is reduced by ‎‎18.19 % for 25ppm , 17.15% for 50 ppm and 13.17% for 100 ppm .The emission results at ‎all loads show a reduction of the (UHC) , (NO X ) and (CO) emission by 15.6% , 16% and ‎‎18.18% respectively for 25 ppm .‎

Construction sites are among the most dangerous construction industries in terms of exposing ‎the safety and health of workers to various dangerous accidents during the construction process. ‎Where the statistics of the International Labor Organization show that there is one death every three ‎minutes as a result of a work injury and that there are four different injuries occurring in the world ‎every second. The construction industry has been identified as one of the most dangerous industries, ‎due to the nature of the work resulting from the integration of materials, tools, the environment and ‎various human factors. A message of worker safety consideration during design sites. It is necessary to ‎give the highest importance to the occupational and health safety of workers in construction projects ‎sites in order to reduce risks and losses. Among worker. Iraq suffers from a lack of attention to safety ‎and health of employment. Despite the importance of safety and health for workers, we note that ‎research that deals with on the issue of safety in construction projects is still very little. Empirical ‎studies on the effect of national culture on safety attitudes, behavior, and performance appear to be ‎few. It does not seem unreasonable to expect people’s attitudes toward risk to differ according to the ‎deep values, beliefs and assumptions that local culture influences safety in projects. Therefore, the ‎focus was on the most important factors affecting the safety and health of workers in construction ‎sites and making suggestions about who bears these injuries to the employer or contractor and all ‎safety measures are mentioned while writing the contract and placing them as basic conditions in the ‎project. ‎

Over the past 50 years, the development of high-temperature engineering alloys had been a primary driver of ‎increased operating temperatures for material used in gas turbine engines. This has resulted in dramatic ‎improvements in both their power and efficiency. It has been reported that a 170 ℃ increase in the engine ‎operating temperature improves an engine‘s thrust by 5 % and the efficiency by 1%. Materials used for turbine ‎blades and vanes found in the hot sections of gas turbine engines must endure extremely hot engine gases, an ‎oxidative and hot corrosive environment, large centrifugal loads, and high-velocity foreign object impacts. New ‎blade/van materials must therefore possess a balance of high-temperature strength, toughness, oxidation, and ‎corrosion resistance.‎
Superalloys are the major class of materials used for the high-temperature components in the fact that they ‎are the only commercially available materials that retain their mechanical and corrosion / oxidation-resistant ‎properties at high temperatures (up to 0.9 Tm). There are three main classes of superalloys: nickel-base superalloys, ‎cobalt-base superalloys, and iron-base superalloys. Superalloys are currently used in many high-temperature fields ‎from gas turbines used in aircraft, marine, and industrial applications, to space vehicles, nuclear reactors, steam ‎power plants, and petrochemical equipment. The largest consumer of superalloys today the aircraft gas turbine ‎engine industry. In this review, each group of superalloys has briefly presented its key characteristics and chemical ‎compositions. Lastly, their manufacturing uses were illustrated.‎

The powder metallurgical process has the distinctive advantage of near net shape ‎manufacturing, getting rid of finished machining processes and hence material wastage. Mechanical ‎alloys mix part of metal powder into a powder metallurgical route to create alloys very similar to ‎historically developed alloys. Mechanical alloys are the sound alloying process. Metal powders are ‎mixed to create a consistent delivery before compaction with the aid of ball mill. The composites of ‎the hybrid metal matrix have two separate secondary phases founded in the primary phase, that ‎demonstrate an intriguing behavior and are worth studying in the field of composite science. In this ‎study, various previous studies on mechanical alloy of aluminum with different components and ‎metals are reviewed and their findings are illustrated, in contrast with conventional alloys.‎

The research tackled one of the important housing problems in Iraq, which is the problem of ‎affordable housing, by identifying the real housing need in the target year in the year 2030, as the year ‎‎2019 was adopted as the base year. The importance of this came as a result of the disparity of ‎statistics about the real number required of housing units. Also the research focused on the importance ‎of the anchor of the social factor in the comfort and reassurance of the residents, and not the ‎economic anchor exclusively, as is common in affordable housing projects, as this approach resulted ‎in the research problem: The existence of a knowledge gap in the non-response of housing complexes ‎to middle and low societal segments of the basis of the social factor for affordable housing in multi-‎housing units in Iraq, where a group of vocabulary and indicators of affordable housing was identified ‎in the field of the influence of the social factor and that through the literature and studies cited by the ‎research .The basic vocabulary and secondary indicators of social factor were applied to local and ‎regional experiences Where the local experience in the new city of ‎‏ ‏Bismayah has produced good ‎results that can be taken in the future in the field of affordable housing, especially the impact of the ‎social factor on the comfort and reassurance of the residents. Affordable housing for young families‎

The urban population is one of the main reasons for the increase in urban area, this will lead to ‎a change in urban land use functions. Planning connects between population growth and urban ‎growth and both will lead to desirable urban growth within the master plan, however, lack of planning ‎leads to undesirable urban growth outside the scope of the master plan. The growing gap between ‎urban growth and population growth will produce the undesirable change in urban functions, such as ‎unsustainable and non-standard urban land use. The aim of this research is to create a positive and ‎balanced positive effect between urban growth and population growth under the influence of the ‎sustainable urban criterion and a functional distribution of the various urban land uses. The equation ‎of simple population growth and the sustainable urban standard and the descriptive historical ‎approach used to link urban growth with population growth, through the accurate forecast of the ‎population is using the population growth equation for years to come may reach ten years. Urban ‎population is distributed on the basis of the uses of urban land, which are balanced by the criteria of ‎using local or regional urban land that respond to the social, economic and cultural situation of the ‎population. The most important conclusion is that the year 2017 recorded a large gap between the ‎inhabited and uninhabited land in favor of uninhabited land, that there are large areas have not been ‎used and expand to future potential growth. However, this gap does not give us the green light, it ‎means the urban planning is not sure responds to the requirements of population growth, especially ‎there are the problem of housing, health, electricity, water, transport, noise and environmental ‎pollution suffer from most developing countries and Iraq is no exception.‎

Course aggregate is the main constituent of Hot Mix Asphalt (HMA) in terms of percentage and ‎load carrying mechanism. Practically, crush aggregate is extensively utilized in production of HMA ‎because of its rough shape form that offers high interlocking, consequently, brings high resistance to ‎traffic loads exposed from moving vehicles. The use of round aggregate in paving is not allowed by ‎highway agencies, especially for surface layers, because of its smooth surface that does not give the ‎required engineering properties. Thus, the coating process is suggested to rough the surface of round ‎aggregate by using different materials to increase the strength for resisting the traffic load. In this ‎research work, the coating process was introduced by using cement mortar comprising waste and ‎natural materials, namely the glass waste particles and the natural sand. Low energy curing process is ‎also used to minimize cost and time for curing of coated aggregates. Results of this research attempt ‎showed that there is a significant improvement in the engineering and durability properties of HMA ‎comprising coated round aggregate. Moreover, microwave treatment offers an alternative to relatively ‎long time traditional curing. So, this can be reflected on minimizing the overall cost of construction of ‎different pavement layers and the environmental impact come from crushing aggregate and use of ‎natural materials can be reduced. ‎

The research aims to study the impact of structural change makeup for the cover of the ‎buildings in the city of Baghdad on the thermal loads .which included these variables to change the ‎quality of construction materials for walls and ceilings and the quality of thermal insulation material ‎added, the quality of packing material external and internal quality of the glass front of the building, ‎the effect of the presence of air gap between the walls, change the orientation of buildings.‎
The study found that the best direction to achieve lower pregnancy cooling is the direction of ‎the north and the highest heat load occurs in a westerly direction, and the current building materials are ‎higher than the standard thermal and therefore must use a system of thermal insulation to reduce the ‎carrying cooling, which will be available in the range of 35% to85% of the heat load on insulation in ‎walls and 32% to 75% when isolating ceilings