Photovoltaic cells are one of the renewable energy sources that have been employed to produce electrical energy from solar radiation falling on them, but not all incident radiate will produce electrical energy, part of those radiate cause the panel temperature to rise, reducing its efficiency and its operational life, unless an attempt is made to employ one of the traditional cooling methods or innovating other methods to cooling it to reduce this effect, which it represented in the active and passive cooling method. In fact, it is difficult to compare the active method with the passive method, as each method has its Advantages and disadvantages that may suit one region without another. But in general, there are basic factors through which at least a comparison between the two methods can be made. Relatively the passive method is less expensive, in addition to no need for additional parts such as pumps and controllers, there is no energy consumption because it does not require power. But it is less effective and efficient than the active method, while the active method has the ability to disperse the heat higher than the passive method. However, it necessitates the use of electricity and is frequently costlier than the passive strategy. In this review, the most common active and passive cases were reviewed, and the pros and cons of each case are summarized in discussion due to the difficulty to list them. The review recommends that future studies should focus on active water cooling and heat-sink, both of which are viable cooling strategies.
The performance of the construction industry is regarded as one of the most significant variables in the global economic development success of nations. As a result, it requires focusing on strengths to enhance them and weaknesses to address them. This study aims to identify the key factors affecting the objectives of construction projects. To achieve the study aim, previous records and documents of two completed projects were studied carefully to identify problems that occurred and the impact of these problems on the project objectives. After that, an experts' interview was conducted to identify the key factors affecting the purposes of the construction project. The results of this study identified (33) key factors affecting the achievement of the construction project objectives, where the factor "The financial allocation for the project" was the most important, while the factor "Bad a health and safety plan in the project" was the least important.
This study aims to investigate the impact of various construction methods on labor productivity in Iraq, focusing on traditional, prefabricated steel structures, precast concrete, and mechanical or self-build construction techniques. The research employs a descriptive-analytical methodology, utilizing a structured survey distributed to 200 participants from different construction industry sectors, including engineers, contractors, and field workers. The survey examines key indicators of labor productivity, such as task completion speed, work quality, labor costs, safety, and project cost.The findings reveal significant differences in labor productivity across the construction methods. Traditional construction methods moderately impacted task completion speed and work quality but were less efficient in terms of cost reduction and safety. On the other hand, prefabricated and precast concrete methods demonstrated improvements in work quality, safety, and cost efficiency, although with some limitations regarding flexibility. Steel structures offered enhanced durability and faster construction times, while mechanical and self-build methods utilizing automation significantly reduced labor costs and accelerated the construction process.Based on these results, the study recommends incorporating modern construction methods, such as prefabricated and mechanical techniques, to improve overall productivity in the Iraqi construction sector. Additionally, it emphasizes the importance of training and adapting to these advanced methods to ensure long-term efficiency, safety, and cost-effectiveness in construction projects.
Recently our country is witnessed an implementation of many construction with high stories . thus , the accuracy of implementation and monitoring of survey works should be consider . in this paper quality control in survey works in AL-RAHMAN Mosque were studied as a case study . The magnitude and correlation of errors are importance to the design stage, measuring and adjustment development .in the design stage the study of errors is very important to provide us the basic chose of fingers , selection of instrument types, and proper procedures to get the specified accuracy , in the measuring sate the stud of errors is an important because it give us acceptation or rejection limitation in the site. In the adjustment operation the study of errors give us an increment in can riddance level the result of present paper indicated that there are conclusion and recommendation should be considered to accept or reject in future works.