Experimental investigations had been done in this research to demonstrate the effect of carbon fiber and Ceramic fillers contents on the tribological behaviour of (15% volume fraction) carbon-epoxy composite system under varying volume fraction, load, time and sliding distance. The wear resistance were investigated according to ASTM G99-05standard using pin on disc machine to present the composite tribological behaviour. The influence of three ceramic fillers, granite, perlite and calcium carbonate (CaCO3), on the wear of the carbon fabric reinforced epoxy composites under dry sliding conditions has been investigated. The effect of variants in volume fraction, applied load, time and sliding distance on the wear behaviour of polymer composites is studied by measuring the weight changes . In the experiments with wear test pin having flat face in contact with hardening rotating steel disc, sliding speed, time and loads in the range of 200 RPM, 300–900s and 40–60 N respectively was used. It is observed that the wear resistance increase with the increasing of reinforcement material volume fraction while, the wear rate increases with increasing of applied load, time and sliding distance. The results showed that the filler of granite perlite and CaCO3 as filler materials in carbon epoxy composites will increase the wear resistance of the composite greatly than carbon fiber fillers epoxy composite only and granite filled CE Composite exhibited the maximum wear resistance.
The imperative of achieving financial stability has transcended national boundaries, necessitating heightened attention from both researchers and policymakers. Consequently, this article delves into an examination of the impact of government debt and public debt on financial development within the context of Iraq. The study employs monetary policy, interest rate, inflation, and population growth as control variables to prognosticate financial development. Utilizing data extracted from the World Development Indicators (WDI) spanning the period from 1995 to 2022, the study employs the dynamic autoregressive distributed lag (DARDL) approach to scrutinize the associations under investigation. The findings underscore a negative association betwe
... Show MoreAbstract:
The problem of poverty is one of the most important development challenges facing developing countries including Sudan for several decades. Although many efforts have been made to reduce poverty, however, its rates are increasing, and public policies adopted by the government in this regard remain elusive in achievinging its main objectives or making any significant progress. The purpose of the present study is to analyse poverty in Sudan by identifying its measurement, causes and the factors that have contributed to the increasing poverty rates over the past two decades. Also this study aims at investigating the interim poverty reduction strategy in Sudan as well as evaluates that strategy throug
... Show MoreObjective:Fluorid-containing dental alginate impression materials can exert a considerable reduction in
enamel solubility. The objective was to evaluate the effect of fluoride addition on the setting time and
compressive strength of alginate impression materials.
Methodology: 60 samples were constructed from alginate impression material (30 samples for setting
time test and 30 samples for compressive strength test).Specimens of each test divided into three
subgroup. Group A: 10 specimens of alginate were mixed with distilled water [control], Group B: 10
specimens of alginate were mixed with100-ppm fluoride and Group C:10 specimens of alginate were
mixed with 2%Naf.
Results: the result of setting time test showed t
Heterocyclic compounds are employed in many applications, and numerous researchers have created liquid crystals by adding heterocyclic to the structures of these molecules. This work includes the synthesis and characterization of new compounds that contain 5H-thiazolo [4,3-b][1,3,4] thiadiazol united in multiple steps, starting with the synthesis of the aldehyde compound [I] by reaction chloro ethyl acetate with 4-hydroxybenzaldehyde in the presence of ethanol and potassium carbonate, followed by reactions with thiosemicarbazide, mercapto acetic acid in sulphuric acid to produce compound [II] then reflux compound [II] with hydrazine hydrate to product compound [III], after that reaction the later compound with nalkoxybenzaldehyde [IV]n and
... Show MoreIn The Name of Allah Most Gracious Most Merciful
This is a study dedicated to explaining the conditions of the end of heaven, stage by stage; And to draw the final picture of it, through the facts of the Qur’an, and to make the contextual integration of the verses of the end of heaven, and their arrangement in an intentional arrangement, a path that guides us to knowing the integrated picture of it on the Day of Resurrection, according to scientific interpretation.
The importance and usefulness of the research lies in:
Extracting the order of the stages of the end of heaven, from its first state to its last, which came in separate verses of the Qur’an, each one of which was placed in a surah that was consistent w
... Show MoreMonitoring water quality in hemodialysis systems is extremely important to maintain adequate quality services for patients suffering from kidney failure. This work aims to examine and evaluate bacteriological characteristics and endotoxin contamination levels in hemodialysis water produced in dialysis centers. Forty‐eight water samples were collected and analyzed from four major hospitals in Baghdad for one year to evaluate seasonal effects. The analysis included the determination of total heterotrophic bacteria using the pour plate method, identification of bacterial isolate using the Vitek2 compact instrument, and the determination of endotoxins levels using Limulus ameboc
Soil that has been contaminated by heavy metals is a serious environmental problem. A different approach for forecasting a variety of soil physical parameters is reflected spectroscopy is a low-cost, quick, and repeatable analytical method. The objectives of this paper are to predict heavy metal (Ti, Cr, Sr, Fe, Zn, Cu and Pb) soil contamination in central and southern Iraq using spectroscopy data. An XRF was used to quantify the levels of heavy metals in a total of 53 soil samples from Baghdad and ThiQar, and a spectrogram was used to examine how well spectral data might predict the presence of heavy metals metals. The partial least squares regression PLSR models performed well in pr
A mixture model is used to model data that come from more than one component. In recent years, it became an effective tool in drawing inferences about the complex data that we might come across in real life. Moreover, it can represent a tremendous confirmatory tool in classification observations based on similarities amongst them. In this paper, several mixture regression-based methods were conducted under the assumption that the data come from a finite number of components. A comparison of these methods has been made according to their results in estimating component parameters. Also, observation membership has been inferred and assessed for these methods. The results showed that the flexible mixture model outperformed the
... Show MoreThe study included the extraction of volatile oil from Mentha piperita which was 1.3 % in the leaves and flowers . Volatile oil of the Mentha piperita leaves had special aromatic odour, pale yellow color, slightly pungent taste . The specific gravity and refractive index were (0.9794) and ( 1.464) respectively. The inhibition activity of the Mentha piperita Volatile oil extracts were studied on some pathogenic microorganisms like Staphylococcus aureus, Salmonella typhi, Escherichia coli, Proteus sp, and Klebsiella pneumoniae . The result showed that the volatile oil had an inhibition effect on the growth of all microorganisms, and it gave the higher inhibition effect on the growth of S. aureus in which the inhibition zone reached to 2
... Show MoreForty one isolates of genus Proteus were collected from 140 clinical specimens such as urine, stool, wound, burn, and ear swabs from patients of both sex. These isolates were identified to three Proteus spp. P. mirabilis, P. vulgaris and P. penneri .The ability of these bacteria to produce L-asparaginase II by using semi quantitative and quantitative methods was determined. P. vulgaris Pv.U.92 was distinguished for high level of L-asparaginase II production with specific activity 1.97 U/mg. Optimum conditions for enzyme production were determined; D medium with 0.3% of L-asparagine at pH 7.5 with temperature degree 35°C for incubation. Ultrasonication was used to destroy the P. vulgaris Pv.U.92 cells then ASNase II was extracted and pu
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