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.
New Schiff bases derived from D-galactose were synthesized by condensation of aldehyde (1,2:3,4-Di-O-isopropylidene-6-carboxaldehyde-α-D-galactopyranose) with different aromatic amines such as (4-bromo, 3-hydroxy, 4-iodo, 4-methoxy) aniline in dry benzene using glacial acetic acid as a catalyst. These compounds were converted to oxazepine derivatives by addition reaction with maleic anhydride in dry benzene as a solvent. The structures of the synthesized compounds have been characterized by elemental analysis, FTIR spectra, some of them by using 1HNMR spectra and measurement of its physical properties.
For a given loading, the stiffness of a plate or shell structure can be increased significantly by the addition of ribs or stiffeners. Hitherto, the optimization techniques are mainly on the sizing of the ribs. The more important issue of identifying the optimum location of the ribs has received little attention. In this investigation, finite element analysis has been achieved for the determination of the optimum locations of the ribs for a given set of design constraints. In the conclusion, the author underlines the optimum positions of the ribs or stiffeners which give the best results.
Requires economic work finding built institutional paint strategies and policies are formulated general economic and clarity in its stated objectives and the involvement of all economic institutions, political and stakeholders to discuss all the issues of economic, financial, monetary and analyzed for the purpose of renewal energies and determine the duties and responsibilities, leaving full freedom to the private sector in the formation of institutions to carry out his duties economic, and that the institutional structures to create the right climate for the implementation of its economic policies, which would facilitate the task of the private sector, and this h
... Show More<p>The objective of this paper is to study the dynamical behavior of an aquatic food web system. A mathematical model that includes nutrients, phytoplankton and zooplankton is proposed and analyzed. It is assumed that, the phytoplankton divided into two compartments namely toxic phytoplankton which produces a toxic substance as a defensive strategy against predation by zooplankton, and a nontoxic phytoplankton. All the feeding processes in this food web are formulating according to the Lotka-Volterra functional response. This model is represented mathematically by the set of nonlinear differential equations. The existence, uniqueness and boundedness of the solution of this model are investigated. The local and global stability
... Show MoreGenus Eucalyptus belongs to the family Myrtaceae that consists of more than 700 species, various hybrids and varieties. The majorly distributed species that are grown in Iraq are Eucalyptus alba, E. macarthurii, E. siderophloia and E. camaldulensis, E. tereticornis, E. vicina. Most Eucalyptus species are highly dependent on rainfall, and this is challenged by climatic changes owing to global warming making it difficult to effectively match the availability of mature trees and the market demand, especially for use as power transmission poles. With the widespread availability of other naturally occurring Eucalyptus species, it has become important to determine the genetic diversity and to analyze the phenotypic tra
... Show MoreLow conversion copolymerization of N-vinyl-2-pyrrolidon M.W = (111.14) VP (monomer-1) has been conducted with acrylic acid AA and methymethacrylate MMA in ethanol at 70ºC , using Benzoyl peroxide BPO as initiator . The copolymer composition has been determined by elemental analysis. The monomer reactivity ratios have been calculated by the Kelen-Tudos and Finman-Ross graphical procedures . The derived reactivity ratios (r1 , r2 ) are : (0.51 , 4.85) for (VP / AA ) systems and (0.34 , 7.58) for (VP , MMA) systems , and found the reactivity ratios of the monomer AA , MMA is mor than the monomer VP in the copolymerization of (VP / AA) and (VP /MMA) systems respectly . The reactivity ratios values were used for microstructures calculation.
This study was designed to investing the drug prescribing pattern which is the important point in the rational or irrational use of drugs among patients dispensing their prescriptions from the private pharmacies in Maysan governorate, Iraq for a period of 1 month. The data collected from prescriptions were calculated and analyzed according to the WHO prescribing guidelines. The data showed that the mean of drugs included in single prescription was 3.4, and 12% of prescribed drugs were written as generic names; moreover, the percentage of antibiotics, corticosteroids and anxiolytics were 33.3%, 11.4% and 23.8% respectively. Those results indicate the irrational use of drugs when compared with the world health organization standard values
... Show MoreDue to the large population of motorway users in the country of Iraq, various approaches have been adopted to manage queues such as implementation of traffic lights, avoidance of illegal parking, amongst others. However, defaulters are recorded daily, hence the need to develop a mean of identifying these defaulters and bring them to book. This article discusses the development of an approach of recognizing Iraqi licence plates such that defaulters of queue management systems are identified. Multiple agencies worldwide have quickly and widely adopted the recognition of a vehicle license plate technology to expand their ability in investigative and security matters. License plate helps detect the vehicle's information automatically ra
... Show MoreThis research deals with Salinger's concerns about predicaments of youth like Franny and her brother Zooey. Their predicaments are related to identity, family, religion, beliefs, life and death, education, source of power, and society. It illustrates adults struggle to adapt themselves to live a normal social American life. It proves necessary to balance their coexistence in a materialistic milieu to achieve spiritual peace, tranquility, and stability.
Ebastine (EBS) is a non-sedating antihistamine with a long duration of action. This drug has predominantly hydrophobic property causing a low solubility and low bioavailability. Surface solid dispersions (SSD) is an effective technique for improving the solubility and dissolution rate of poorly soluble drugs by using hydrophilic water insoluble carriers.
The present study aims to enhance the solubility and dissolution rate of EBS by using surface solid dispersion technique. Avicel® PH101, Avicel® PH 102, croscarmellose sodium(CCS) and sodium starch glycolate(SSG) were used as water insoluble hydrophilic carriers.
The SSD formulations of EBS were prepared by the solvent evaporation method in different drug: carrier
... Show More