A novel welded demountable shear connector for sustainable steel-concrete composite structures is proposed. The proposed connector consists of a grout-filled steel tube bolted to a compatible partially threaded stud, which is welded on a steel section. This connector allows for an easy deconstruction at the end of the service life of a building, promoting the reuse of both the concrete slabs and the steel sections. This paper presents the experimental evaluation of the structural behavior of the proposed connector using a horizontal pushout test arrangement. The effects of various parameters, including the tube thickness, the presence of grout infill, and the concrete slab compressive strength, were assessed. A nonlinear finite element model was also calibrated against the experimental results, and the validated numerical model was used to extend the validity of the experimental results and to perform further parametric studies. The experimental and numerical results show that the tested connectors have similar stiffness, but higher shear resistance and slip capacity compared with traditional welded shear studs and can be classified as ductile according to Eurocode 4.
Ten species of whiteflies (Hemiptera, Aleyrodidae) representing six genera were studied from a collection from different localities in the middle of Iraq. These species are Acaudaleyrodes rachipora (Singh, 1931); Bemisia afer (Priesner and Hosny,1934); Bemisia tabaci (Gennadius, 1889); Dialeurodes citri (Ashmead,1885); Dialeurodes kirkaldy (Kotinsky, 1907); Neomaskellia andropogonis Corbett, 1926; Siphoninus phillyreae (Haliday, 1835); Trialeurodes ricini (Misra, 1924); Trialeurodes vapovariorum (Westwood,1856) and Trialeurodes irakeensis (Al-Malo and Abdul-Rassoul, 2000). Notes are given on their localities, date of c
... Show MoreThe study aims at finding out:
1. The students' attitude towards the mixed learning at the university.
2. The statistically significant differences in attitude towards the mixed learning at the university according to the specialization variable.
3. The statistically significant differences in attitude towards the mixed learning at the university according to the gender variable.
The researcher has constructed a scale for measuring the students' attitude towards the mixed learning at the university.
After assuring its validity and reliability, the scale has been given to a sample of (100) students. The sample is selected randomly from (4) colleges of the university of Baghdad, (2) for scientific specialization and (2)for h
The excellent specifications of electrodes coated with lead dioxide material make it of great importance in the industry. So it was suggested this study, which includes electrodeposition of lead dioxide on graphite substrate, knowing that the electrodeposition of lead dioxide on graphite studied earlier in different ways.
In this work the deposition process for lead dioxide conducted using electrolytic solution containing lead nitrate concentration 0.72 M with the addition of some other material to the solution, such as copper nitrate, nickel nitrate, sodium fluoride and cetyl trimethyl ammonium bromide, but only in very small concentrations. As for the operating conditions, the effect of change potential and temperature as well
... Show MoreEdward Albee, as a playwright, indicates that art should be useful and have a message. Therefore, his work foregrounds and critically examines issues concerning the Neurosis of Blackness and psychological trauma. Albee uses cruelty of racism in reflecting psychological trauma and emotional abuse of American black identity in his plays. Race, social inequality, and gender still sustain to engender controversy audience consciously. Racial discrimination is one of the major issues that affect the American Society. Albee challenges and exposes the presumptive dreams of equality of American society and institutional racism. Therefore, one of the main problems of the twentieth century in America is skin color. It
... Show MoreThe whole research paper examines the impact of ozone as either a just use-alone and coagulation benefit, mainly upon the reduction of dissolved organic carbon from the water with a moderate rate of DOC 10.75 mg/land CaCO3 calcium hardness 300 mg/l. A raw water sample has been taken from the Tigris River (Baghdad, Iraq) was being adopted in research work. The performance of ozone therapy has been assessed by calculations of DOC, DOC quantities, UV254, as well as total trihalomethane (TTHM). Research findings have shown that with 0.9 mg O3/mg DOC ozone use-alone, approximately 60% UV254 reduction and approximately 28% DOC reduction will occur.DOC fractionation analysis indicates that within the water samples, ozone could alter the co
... Show MoreDental clinicians and professionals need an affordable, nontoxic, and effective disinfectant against infectious microorganisms when dealing with the contaminated dental impressions. This study evaluated the efficiency of hypochlorous acid (HOCl) as an antimicrobial disinfectant by spraying technique for the alginate impression materials, compared with sodium hypochlorite, and its effect on dimensional stability and reproduction of details. HOCl with a concentration of 200 ppm for 5 and 10 min was compared with the control group (no treatment) as a negative control and with sodium hypochlorite (% 0.5) as a positive control. Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa were selected to assess the antimicrobi
... Show MoreThe objective of this study is to analyze the difficulties faced by intermediate-level Iraqi students in the use of Spanish unstressed pronouns as a foreign language (ELE). Through a mixed methodology, a descriptive and explanatory analysis was conducted based on written and oral productions of B1-level students at the University of Baghdad.The results show that factors such as interference from the native language (Arabic) and English, as well as grammatical differences between Spanish and Arabic, generate difficulties in the correct use of unstressed pronouns. A contrastive teaching approach is proposed that takes advantage of students' cognitive abilities to highlight similarities and differences between both languages.This stu
... Show MorePraise be to God alone, and after:
This is a research entitled: “A fundamental study of judicial jurisprudence rules and their applications in the Hanbali school of thought,” in which the researcher studied eight legal jurisprudential rules considered by the Hanbalis and others.
At the conclusion of his research, the researcher reached a number of results, including: the importance of taking care of judicial rules, and the need for judges and their assistants to them, including: the need for students of science in Hanbali jurisprudence to study these rules according to the doctrine, and to highlight their applications to them, including: the importance of the rules under study, and their impact on rulings Jurisprudenc
... Show MoreVascular plants that have been identified during the study seasons in the Island. The cultivated plants were 126 species belong to 103 genera and to 49 families of the year 2001-2002 . The natural vegetation in this Island has been subjected to a total disturbance and subsidence due to the comprehensive turbidity of the Island environment.Number of names of that natural vegetation has been mentioned in the study within the weed plants.The results of the study of the period of flowering and their attitudes show clear seasonal differences. During the cold months of winter, the number of the cultivated and the natural plants was at the rate of 15%.These kinds of flowers require high level of care to increase their numbers. While in the spring
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