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Silica Fume Modified Cement-Based Mortar Exposed to High Temperatures: Residual Strengths and Microstructure

Several previous investigations and studies utilized silica fume (SF) or (micro silica) particles as supplementary cementitious material added as a substitute to cement-based mortars and their effect on the overall properties, especially on physical properties, strength properties, and mechanical properties. This study investigated the impact of the inclusion of silica fume (SF) particles on the residual compressive strengths and microstructure properties of cement-based mortars exposed to severe conditions of elevated temperatures. The prepared specimens were tested and subjected to 25, 250, 450, 600, and 900 °C. Their residual compressive strengths and microstructure were evaluated and compared with control samples (CS) subjected to similar conditions (the same temperature category). The outcomes indicated that including silica fume particles in mortar mixtures lowered the amount and width of microcracks, upgraded the mass-loss performance, lowered crystalline calcium hydroxide, and reinforced the cement paste, which explained the improvement in residual mechanical strengths.

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Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Heating and Melting Model Induced by Laser Beam in Solid Material

An analytical method and a two-dimensional finite element model for treating the problem of laser heating and melting has been applied to aluminum 2519T87and stainless steel 304. The time needed to melt and vaporize and the effects of laser power density on the melt depth for two metals are also obtained. In addition, the depth profile and time evolution of the temperature before melting and after melting are given, in which a discontinuity in the temperature gradient is obviously observed due to the latent heat of fusion and the increment in thermal conductivity in solid phase. The analytical results that induced by  laser irradiation is in good agreement with numerical results.

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Publication Date
Tue Apr 01 2014
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Pleural Effusion: Characterization With contrast CT Appearance and CT Attenuation Values

Background: A number of different types of fluid may accumulate in the pleural space, the most common being transudate, exudate (thin or thick), blood and chyle. All types of pleural effusion are radio graphically identical, though historical, clinical and other radiological features may help limit the diagnostic possibilities. Sometimes, also CT and MRI can help to specify the diagnosis.
Objective: To determine the accuracy of computed tomography (CT) in enabling differentiation of pleural exudates from transudates.
Patients and methods: forty three consecutive patients (43 effusions) underwent contrast-enhanced CT. Thoracocentesis was performed to measure pleural and serum total protein values. Effusions were classified as exudat

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Publication Date
Wed Dec 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
Openness Management by Figures as a Model of Integrity and Transparency

Competitive advantage is a substantial  strategic objective for organizations. It requires high levels in the quality of products and services provided to customers, continuous improvement of costing , care for creativity and innovative employees, and speed unique to the marketing and financial engineering, and business re-engineering processes. The situation in this area, requires actors to attract and develop human resources, including help in proper implementation of the strategic tasks that targeted by those institutions. According to the opinions and viewpoints of management scholars, the competitive advantage resource is the most important issue for organizations in the third millennium, which can be a

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Publication Date
Thu Jan 01 2015
Journal Name
Journal Of Engineering
Extraction of heavy metals from contaminated soils using EDTA and HCl

The present study examines the extraction of lead (Pb), cadmium (Cd) and nickel (Ni) from   a contaminated soil by washing process. Ethylenediaminetetraacetic acid disodium salt (Na2EDTA) and hydrochloric acid (HCl) solution were used as extractants.  Soil washing is one of the most suitable in-situ/ ex-situ remediation method in removing heavy metals. Soil was artificially contaminated with 500 mg/kg (Pb , Cd and Ni ).  A set of batch experiments were carried out at different conditions of  extractant concentration , contact time, pH and agitation speed. The results  showed  that the  maximum removal efficiencies  of (Cd, Pb  and Ni ) were (97, 88 and 24 )&nbs

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Publication Date
Tue Feb 13 2024
Journal Name
Iraqi Journal Of Science
The Dynamics of One Harmful Phytoplankton and Two Competing Zooplankton System

In this paper, a mathematical model consisting of harmful phytoplankton and two competing zooplankton is proposed and studied. The existence of all possible equilibrium points is carried out. The dynamical behaviors of the model system around biologically feasible equilibrium points are studied. Suitable Lyapunov functions are used to construct the basins of attractions of those points. Conditions for which the proposed model persists are established. The occurrence of local bifurcation and a Hopf bifurcation are investigated. Finally, to confirm our obtained analytical results and specify the vital parameters, numerical simulations are used for a hypothetical set of parameter values.

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Publication Date
Thu Nov 02 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Oxidative Stress and The Activities of Catalase , GST in Thalassemic Patients

The  study  concentrated  on  measuring  the  lipid  peroxidation marker malon di aldehyde (MDA) in sera of thirty five patients with minor Thalassemia  (Tm), thirty five with major Thalassemia (TM) and thirty five healthy control, their age ranged from (17-30) years. Erythrocytes  enzymes  (Glutathione  -S   - transferase  (GST  )and Catalase) were assayed . The results showed a significant elevation in (MDA) in sera of both patient groups compared to control.

An  increase in the activity of catalase and GST in erythrocytes of

minor Thalassemic patients compared to control was found to be significant. Also, a high significant increase in the

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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Properties of Kumaraswamy binary Distribution and compare methods of estimating parameters

The recent development in statistics has made statistical distributions the focus of researchers in the process of compensating for some distribution parameters with fixed values and obtaining a new distribution, in this study, the distribution of Kumaraswamy was studied from the constant distributions of the two parameters. The characteristics of the distribution were discussed through the presentation of the probability density function (p.d.f), the cumulative distribution function (c.d.f.), the ratio of r, the reliability function and the hazard function. The parameters of the Kumaraswamy distribution were estimated using MLE, ME, LSEE by using the simulation method for different sampling sizes and using preli

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Publication Date
Mon Dec 25 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Spectrophotometric Determination of Cefixime Following Simple Diazotization and Coupling with ?-Naphthol

Cefixime (CFX) was treated with sodium nitrite and hydrochloric acid for diazotization reaction followed by coupling with ?-Naphthol in alkaline medium to form, a yellow colored azo dye compound which exhibits maximum absorption (?max) at 412 nm where the concentration of (CFX) was determined spectrophotometrically. The optimum reaction conditions and other analytical parameters were evaluated. Beer’s law was obeyed in the concentration range of (1-20) ?g.mL-1 with a molar absorptivity of 34870.5 L.mol-1.cm-1. The limit of detection was found to be 0.1090 ?g.mL-1 and the Sandell's sensitivity value was 0.0130 ?g.cm-2. The proposed method could be successfully applied to

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Publication Date
Mon Oct 01 2007
Journal Name
Journal Of The Faculty Of Medicine Baghdad
VDRL, TPHA, immunoglobulin in aborted and multipart woman's in Baghdad governorate

Background: Syphilis disease remain as a problem especially in developing countries. it can be detected by serological tests and the infection may affected the immunoglobulins concentration and may cause spontaneous abortion.

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Publication Date
Sun Jul 01 2007
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The Relationship Between Helicobacter Pylori Infection And Childhood Idiopathic Thrombocytopenic Purpura

Background: Idiopathic thrombocytopenic purpura , a disorder characterized by autoantibody mediated platelets destruction causing decreased number of circulating platelets manifest as bleeding tendency. Since the discovery of Helicobacter pylori (H. pylori ) several studies have been published concerning a hypothetical role of this bacteria in idiopathic thrombocytopenic purpura.
Aim of the study: Evaluate the pathogenic correlation between H.pylori infection and idiopathic thrombocytopenic purpura.
Patients and Method: A cross sectional study was done on 30 cases of idiopathic thrombocytopenic purpura admitted to the Pediatric Hemato-Oncology unit in ALKadhimiyia Teaching Hospital and 20 cases of

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