Abstract : Several issues arise that can’t be resolved during the execution of a project. Such problems typically include contractor requests for extension of time or an additional cost, or both. When the contractor requests them, they are called claims. The issue is sorted if the owner accepts the contractor claim and grants him extension of time or additional cost, or both. If owner does not agree to the contractor claim and there are various interpretations, the claim becomes a dispute. To avoid or reduce claims in the construction projects it is required to investigate the causes of claims. This study aims to understand of causes of the claims in the building projects in Egypt in an attempt to enable practitioners to be familiar with claims to avoid or minimize when they occur. From international literature, factors that cause claims were identified then modified by expert questionnaire to be suitable to Egyptian construction. Then the factors were subjected to questionnaire to identify their importance. The responses were analyzed by spearman coefficient, Cronbach's alpha variable, k-s test, and one sample t-test. To analyze the collected data of the research, Statistical Package for the Social Science (SPSS) were used. The most prevalent causes of claims that were deduced..
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Abstract : Due to the high importance of phase change material (PCM) in engineering applications, huge works devoted to studying this field of science. In this work, a literature review is presented showing the important works in this field and the possible improvements in the thermal performance of the PCM by using various technical methods like using; fins, metal foam, adding additives of high thermal conductivity, and encapsulation techniques. The review also includes some previous studies that surveyed the used material and their engineering applications. The review includes the possible mathematical models that could be used successfully to formulate the thermal behavior of the PCM..
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Abstract : An unconventional interface is described whereby infill panels are separated from the plane Reinforced concrete (RC) frame employing an adaptive layer of Pneumatic interface material whose interface property can be changed by varying the interface pressure. Using fully infilled RC frames subjected to cyclic in-plane load within the elastic limit, the theory was able to verify experimentally. The results from tests show the interface pressure optimization and the pressure pattern for the better ductile behaviour of the infilled frames. Conclusions Up to modest drifts, the suggested method has an excellent perspective in decreasing the interaction between the structure of the infill and, by extension, the disintegration of the infills. The interaction exists once the interface is compressed and at increased drift. In this way, an infilled frame with a Pneumatic interface can act as a bare frame and infilled frame with interface pressure variations..
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Abstract : For over many centuries, researchers have been working on a quite normal shape frame structures such as square and rectangular frame structures which is easily adaptable. High-rise building is being more common these days. So, in case of high-rise buildings, regular shape of such buildings like square and rectangular frame structures are not good enough in resisting the lateral loads such as wind and seismic loads. To resist more lateral force for superstructures a new geometry of frame configuration is adapted, which is known as trapezoidal frames. In this study, two-dimensional single-bay single-storey reinforced concrete trapezoidal infilled frame with cement mortar as interface and optimization of different percentage of openings in infill were analyzed under static loading. In particular, the paper discusses about the results such as displacement, lateral stiffness, bending moment, shear force and lateral load and stresses in infill wall..
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Abstract : The bacteriocin activity test using proteolytic enzymes aims to confirm the test, namely to ensure that the antibacterial substance produced by Lactobacillus plantarum is bacteriocin. As an antibacterial, bacteriocins have properties that can be degraded by proteolytic enzymes. The parameters measured in this study were the inhibition zone test on the indicator pathogenic bacteria Escherichia coli, Salmonella typhi. and Staphylococcus aureus. The analysis of the research data was the analysis of Completely Randomized Design (CRD). The results showed that increasing storage time had a significant effect (P<0.05) on bacteriocin activity (inhibition zone diameter) against pathogenic bacteria Escherichia coli, Salmonella typhi. and Staphylococcus aureus. Optimum fermented chicken egg bacteriocin activity at room temperature storage for 96 hours can be seen from the formation of clear zones on the indicator medium. The data obtained showed that Escherichia coli and Salmonella typhi were sensitive and had larger inhibition zones than Staphylococcus aureus. Based on the inhibition zone test, inhibition was greater for Gram-negative bacteria (Escherichia coli and Salmonella typhi) when compared to Gram-positive bacteria (Staphylococcus aureus)..
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