In this study, the response of ten composite post-tensioned concrete beams topped by a reinforced concrete deck with adequate reinforcing shear connectors is investigated. Depending on the concrete compressive strength of the deck slab (20, 30, and 40 MPa), beams are grouped into three categories. Seven of these beams are exposed to a fire attack of 700 and 800 °C temperature simultaneously with or without the presence of a uniformly distributed sustained static loading. After cooling back to ambient temperature, these composite beams are loaded up to failure, using a force control module, by monotonic static loading in a four-point-bending setup with two symmetrical concentrated loads applied in the middle third of the effective span. The objectives of this study include investigating the behavior of the composite prestressed concrete beams under and after the exposure to a direct fire flame, as well as finding their residual load-carrying capacity. Tests demonstrate significant deteriorations caused by exposure to high temperatures associated with the increase of the member’s camber. The increase of the midspan camber after heating exposure reached approximately 200%. On the other hand, the 1-h steady-state exposure of test specimens to temperatures of 700 and 800 °C led to reduce the load-carrying capacity of the heat-deteriorated beams up to 45% and 54%, respectively.
This research deals with the design and simulation of a solar power system consisting of a KC200GT solar panel, a closed loop boost converter and a three phase inverter by using Matlab / Simulink. The mathematical equations of the solar panel design are presented. The electrical characteristics of the panel are tested at the values of 1000 for light radiation and 25 °C for temperature environment. The Proportional Integral (PI) controller is connected as feedback with the Boost converter to obtain a stable output voltage by reducing the oscillations in the voltage to charge a battery connected to the output of the converter. Two methods (Particle Swarm Optimization (PSO) and Zeigler- Nichols) are used for tuning
... Show MoreNatural Bauxite (BXT) mineral clay was modified with a cationic surfactant (hexadecy ltrimethy lammonium bromide (BXT-HDTMA)) and characterized with different techniques: FTIR spectroscopy, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The modified and natural bauxite (BXT) were used as adsorbents for the adsorption of 4- Chlorophenol (4-CP) from aqueous solutions. The adsorption study was carried out at different conditions and parameters: contact time, pH value, adsorbent dosage and ionic strength. The adsorption kinetic (described by a pseudo-first order and a pseudo-second order), equilibrium experimental data (analyzed by Langmuir, Freundlich and Temkin isotherm models) and thermodynamic parameters (change in s
... Show MoreBackground: Economic Globalization affects work condition by increasing work stress. Chronic work stress ended with burnout syndrome.
Objectives: To estimate the prevalence of burnout syndrome and the association of job title, and violence with it among physicians in Baghdad, and to assess the burnout syndrome at patient and work levels by structured interviews.
Subjects and Methods: A cross section study was conducted on Physicians in Baghdad. Sampling was a multistage, stratified sampling to control the confounders in the design phase. A mixed qualitative and quantitative
... Show MoreHypertension is a major health problem throughout the world because of its high prevalence and its association with increased risk of cardiovascular diseases. It is defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. The aim of this study was to compare the efficacy, safety and cardiovascular disease risk lowering ability, of three antihypertensive drug regimens.
A retrospective study was carried out on 66 hypertensive patients, divided in to three groups based on their antihypertensive drug regimens (ACE inhibitors, β-blockers treated and combination antihypertensive therapy, the combination therapy consist of two or more of the following antihypertensive drugs ACE inhibitor di
... Show MoreBackground: Oral Lichen Planus (OLP) is a chronic inflammatory mucosal disease, presenting in various clinical forms WHO had regarded OLP as a precancerous conditions in 1978 because of its potential with cancer. Both antigen-specific and nonspecific mechanisms involved in the pathogenesis of OLP. Oral Squamous Cell Carcinoma (OSCC) is the most common malignant neoplasm of the oral cavity representing more than 94% of oral cancer. It occurs in different sites and has many etiological factors. Cyclin Dl is a proto-oncogene which consider as the key protein in the regulation of cell proliferation and its overexpression led to the occurrence and progression of malignant tumors.NF-KB p65 is a member ofNF-kB family of transcription factors that
... Show MoreIn this paper a system is designed and implemented using a Field Programmable Gate Array (FPGA) to move objects from a pick up location to a delivery location. This transportation of objects is done via a vehicle equipped with a robot arm and an FPGA. The path between the two locations is followed by recognizing a black line between them. The black line is sensed by Infrared sensors (IR) located on the front and on the back of the vehicle. The Robot was successfully implemented by programming the Field Programmable Gate Array with the designed system that was described as a state diagram and the robot operated properly.
The 3-aminoacetophenone and 4-aminoantipyrine were used as precursors to prepare new six ligands. The three new ligands (L1,L2 and L3) were synthesis by reacting one mole of 3-aminoacetophenone with one mole of (Acetyl chloride), (benzoyl chloride), (4-methoxybenzoyl chloride) and ammonium thiocyanat in acetone as a solvent, they are:- L1 (AAA) =[N-(3-acetylphenylcarbamothioyl)acetamide] L2 (BAA) =[N-(3-acetylphenylcarbamothioyl)benzamide] L3 (MAA) =[N-(3-acetylphenylcarbamothioyl)-4-methoxy benzamide] Also three new derivatives of 4-aminoantipyrine were synthesis by reacting one mole of 4-aminoantipyrine with one mole of (Acetyl chloride), (benzoyl chloride), (4-methoxybenzoyl chloride) and ammonium thio
... Show MoreBackground: Economic Globalization affects work condition by increasing work stress. Chronic work stress ended with burnout syndrome. Objectives: To estimate the prevalence of burnout syndrome and the association of job title, and violence with it among physicians in Baghdad, and to assess the burnout syndrome at patient and work levels by structured interviews. Subjects and Methods: A cross section study was conducted on Physicians in Baghdad. Sampling was a multistage, stratified sampling to control the confounders in the design phase. A mixed qualitative and quantitative approach (triangulation) was used. Quantitative method used self-administered questionnaires of Maslach Burn out Inventory. Qualitative approach used an open-end
... Show MoreThe current study used extracts from the aloe vera (AV) plant and the hibiscus sabdariffa flower to make Ag-ZnO nanoparticles (NPs) and Ag-ZnO nanocomposites (NCs). Ag/ZnO NCs were compared to Ag NPs and ZnO NPs. They exhibited unique properties against bacteria and fungi that aren't present in either of the individual parts. The Ag-ZnO NCs from AV showed the best performance against E. coli, with an inhibition zone of up to 27 mm, compared to the other samples. The maximum absorbance peaks were observed at 431 nm and 410 nm for Ag NPs, at 374 nm and 377 nm for ZnO NPs and at 384 nm and 391 nm for Ag-ZnO NCs using AV leaf extract and hibiscus sabdariffa flower extract, respectively. Using field emission-scanning electron microscopes (FE-
... Show MorePreparation of Carboxy Methylated mPEG-Block-(4-Dodecyl Anilide) Copolymers and Their Visco Metric and Surface Tension Properties in THF