Preferred Language
Articles
/
VBbtDIcBVTCNdQwCxTPz
Behavior of RC Beams Strengthened with NSM-CFRP Strips Subjected to Fire Exposure: A Numerical Study
...Show More Authors

The use of Near-Surface Mounted (NSM) Carbon-Fiber-Reinforced Polymer (CFRP) strips is an efficient technology for increasing flexural and shear strength or for repairing damaged Reinforced Concrete (RC) members. This strengthening method is a promising technology. However, the thin layer of concrete covering the NSM-CFRP strips is not adequate to resist heat effect when directly exposed to a fire or at a high temperature. There is clear evidence that the strength and stiffness of CFRPs severely deteriorate at high temperatures. Therefore, in terms of fire resistance, the NSM technique has a significant defect. Thus, it is very important to develop a set of efficient fire protection systems to overcome these disadvantages. This paper presents a numerical study that investigates the fire behavior of thermally insulated RC beams flexurally strengthened with NSM-CFRP strips and subjected to fire exposure according to the ISO 834 standard. The numerical study considered three-dimensional finite element models in the ABAQUS software that have been developed to simulate and predict the performance (thermal and structural response) of fire endurance tests on strengthened, uninsulated strengthened, and thermally insulated beams strengthened with NSM-CFRP strips, which were exposed to fire and had different fire insulation schemes. The insulation used was plaster from local material with a thickness range of 25 to 50mm. The variation of the thermal and mechanical properties with the temperature of the constituent materials was considered. All beams' mechanical and thermal responses were adequately simulated using numerical models. The results of the numerical simulations were in good agreement with the experimental data. The fire behavior of the NSM-CFRP strengthened RC beams was examined and particularly the efficiency of the NSM strengthening system during the fire. The behavior in the fire of the NSM-CFRP strengthening system on the RC beams thermally protected with different fire insulation schemes was assessed. Finally, the effectiveness of fire insulation was studied.

Crossref
View Publication
Publication Date
Fri Nov 24 2017
Journal Name
Journal Of Engineering
A new analytic method to tune a fractional order PID controller
...Show More Authors

This paper proposes a new method to tune a fractional order PID controller. This method utilizes both the analytic and numeric approach to determine the controller parameters. The control design specifications that must be achieved by the control system are gain crossover frequency, phase margin, and peak magnitude at the resonant frequency, where the latter is a new design specification suggested by this paper. These specifications results in three equations in five unknown variables. Assuming that certain relations exist between two variables and discretizing one of them, a performance index can be evaluated and the optimal controller parameters that minimize this performance index are selected. As a case study, a third order linear time

... Show More
Publication Date
Fri Nov 24 2017
Journal Name
Journal Of Engineering
A New Analytic Method to Tune a Fractional Order PID Controller
...Show More Authors

This paper proposes a new method to tune a fractional order PID controller. This method utilizes both the analytic and numeric approach to determine the controller parameters. The control design specifications that must be achieved by the control system are gain crossover frequency, phase margin, and peak magnitude at the resonant frequency, where the latter is a new design specification suggested by this paper. These specifications results in three equations in five unknown variables. Assuming that certain relations exist between two variables and discretizing one of them, a performance index can be evaluated and the optimal controller parameters that minimize this performance index are selected. As a case study, a thir

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 16 2019
Journal Name
Al–bahith Al–a'alami
Academic Trends of Paper Press in Comparison with Internet Press A Field Study on Professors o College of Media at University of Baghdad
...Show More Authors

This search seeks to know the trends of academics in the field of Press and audio, video and read press about paper press compared with continued development and widespread deployment of web journalism. This research belongs to descriptive studies which depends on sample survey approach adopted by five-meter design measuring trends. It contains 28 items having applied honesty and reliability transaction and the scale form is distributed to the sample studied of about 110 professors and then the researcher collects them and then applying the appropriate statistical program to get the results. This search seeks to know the trends of academics in the field of Press and audio, video and read press about paper press compared with continu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Dec 01 2023
Journal Name
Case Studies In Construction Materials
Experimental and environmental investigations of the impacts of wood sawdust on the performance of reinforced concrete composite beams
...Show More Authors

View Publication Preview PDF
Scopus (17)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Wed Oct 05 2011
Journal Name
Iraqi Journal Of Physics
Study of linear shrinkage for siliceous materials to meet insulating requirements
...Show More Authors

Preview PDF
Publication Date
Sun Dec 07 2014
Journal Name
Baghdad Science Journal
Seroepidemiological Study of Measles Virus among Young Adults: Response to Revaccination
...Show More Authors

The 2011 Iraqi Measles Control Campaign had as its aim to improve immunization coverage among young adults' 17-24years and, in the longer term, prevention of measles epidemics. The aim of the study is estimation measles vaccination and revaccination efficacy by evaluate the seroprevalence of antibody and response to reimmunization in young adults. A previously vaccinated 189 young adult medical students were tested for measles specific IgG &IgM pre and post catch-up revaccination by using commercially available ELISA. To assess the seroprevalence of antibody response pre measles reimmunization in previously vaccinated young adults; 45 were found to be seronegative. To differentiate between primary and secondary vaccine failure, anti- mea

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jun 01 2007
Journal Name
Al-khwarizmi Engineering Journal
Investigation of heat transfer phenomena and flow behavior around electronic chip
...Show More Authors

Computational study of three-dimensional laminar and turbulent flows around electronic chip (heat source) located on a printed circuit board are presented. Computational field involves the solution of elliptic partial differential equations for conservation of mass, momentum, energy, turbulent energy, and its dissipation rate in finite volume form. The k-ε turbulent model was used with the wall function concept near the walls to treat of turbulence effects. The SIMPLE algorithm was selected in this work. The chip is cooled by an external flow of air. The goals of this investigation are to investigate the heat transfer phenomena of electronic chip located in enclosure and how we arrive to optimum level for cooling of this chip. These par

... Show More
View Publication Preview PDF
Publication Date
Sun Sep 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Electrochemical Behavior of Chemical Conversion Coated Aluminum ASA6061 in Chromic Acid
...Show More Authors

The corrosion behavior of bare and chemical conversion coated (through anodizing) aluminum ASA 606 I in stagnant chromic acid solutions . Solutions of 2, 6 & J O wt. % Cr03 at 45°C, have been investigated using polarization technique. The anodizing experiments were conducted under fixed conditions of 35 minute exposure time and 30 volt supplied voltage. The most important feature achieved was the great difference in behavior between the anodic polarization curves for bare and anodized aluminum in different concentrations of chromic acid solutions.

View Publication Preview PDF
Publication Date
Wed Mar 01 2023
Journal Name
Iraqi Journal Of Physics
FTIR and Electrical Behavior of Blend Electrolytes Based on (PVA/PVP)
...Show More Authors

Polymer electrolytes were prepared using the solution cast technology. Under some conditions, the electrolyte content of polymers was analyzed in constant percent of PVA/PVP (50:50), ethylene carbonate (EC), and propylene carbonate (PC) (1:1) with different proportions of potassium iodide (KI) (10, 20, 30, 40, 50 wt%) and iodine (I2) = 10 wt% of salt. Fourier Transmission Infrared (FTIR) studies confirmed the complex formation of polymer blends. Electrical conductivity was calculated with an impedance analyzer in the frequency range 50 Hz–1MHz and in the temperature range 293–343 K. The highest electrical conductivity value of 5.3 × 10-3 (S/cm) was observed for electrolytes with 50 wt% KI concentration at room

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Aip Conference Proceedings
Behavior of asymmetrical castellated composite girders by gap in steel web
...Show More Authors

View Publication
Scopus (4)
Crossref (3)
Scopus Crossref