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Thermal Characteristics of Closed Wet Cooling Tower Using Different Heat Exchanger Tubes Arrangement
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This paper presents thermal characteristics analysis of a modified Closed Wet Cooling Tower (CWCT) based on heat and mass transfer principles to improve the performance of this tower in Iraq. A prototype of CWCT optimized by added packing was designed, manufactured and tested for cooling capacity of 9 kW. Experiments are conducted to explore the effects of various operational and conformational parameters on the thermal performance. In the test section, spray water temperature and both dry bulb temperature and relative humidity of the air measured at intermediate points of the heat exchanger and packing. Heat exchangers consist of four rows and eight columns for an inline tubes arrangement and six rows and five columns for staggered tubes arrangement. According to experimental data, the inline tubes arrangement has a better thermal performance than the staggered tubes arrangement. The inline tubes arrangement enhanced thermal efficiency more than (7%) compared to the staggered tubes arrangement. Furthermore the effect of added packing to CWCT on thermal performance was significant compared to CWCT without packing. Comparing CWCT with packing, it has been observed that the best performance for the CWCT with packing under heat exchanger. It can be watched that the thermal efficiency for CWCT with packing under heat exchanger and CWCT with packing above heat exchanger approximately (28%) and (16%) higher than that CWCT without packing respectively. This study provides correlations to predict heat and mass transfer considering the influences of operational parameters for both inline and staggered heat exchanger tubes arrangement.

 

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Publication Date
Fri Feb 02 2018
Journal Name
International Journal Of Science And Research (ijsr)
The Compressibility of Clayey Soils Reinforced with Fiberglass
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During the prior three decades numerous research works presented to investigate the behavior of reinforced soil. A, IJSR, Call for Papers, Online Journal

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Publication Date
Sun Oct 30 2011
Journal Name
Journal Of Engineering
Production of Biodiesel Fuel from Used vegetable Oil
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Used vegetable oil was introduced to transesterfication reaction to produce Biodiesel fuel suitable for diesel engines. Method of production was consisted of filtration, transesterfication, separation and washing. Transesterfication was studied extensively with different operating conditions, temperature range (35-80o C), catalyst concentration (0.5-2 wt. % based on oil), mixing time (30-120 min.) with constant oil/methanol weight ratio 5:1 and mixing speed 1300 rpm. The concentration of Fatty acid methyl esters (Biodiesel) was determined for the transesterficated oil samples, besides of some important physical properties such as specific gravity, viscosity, pour point and flash point. The behavior of methyl esters production and the

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Publication Date
Thu Nov 01 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Assessment of Factors That Contribute to Bladder Cancer
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Abstract Objective: The study aimed to assess the factors contributes of patient with bladder cancer and to find out the relationship between the factors of bladder cancer with certain variable. Methodology: A descriptive study to assessment of factors that contribute to bladder cancer that was carried out Al-Karama teaching hospital, Al-Kendy teaching hospital, Specialty Surgery teaching hospital and Al-Yarmok teaching hospital for the period of November 2003 to August 2004. A purposive (non-probability) sample of (100) patients with bladder cancer. An assessment from was constructed for the purpose of the st

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Publication Date
Fri Apr 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The impact of cultural dimensions in nursing performance
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  Abstract

          The  cultural contrast is considered of the essential subjects in the field of administration of international businesses which have great and effective role for representation in one social system for the individuals have various belongings, and the nursing performance is considered  an essential basic for health care, thus  a discussion for two variables have  done to formulate the intellectual frame for this research which are( the cultural contrast and the nursing performance). depended a questionnaire as a research tool by(90) he/ she nurses of the Iraqis and the arrivals( the

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Publication Date
Sat Oct 01 2011
Journal Name
Iraqi Journal Of Physics
Some gas sensing properties of PbS thin films
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In this research PbS thin film have been prepared by chemical bath deposition technique (CBD).The PbS film with thickness of (1-1.5)μm was thermally treated at temperature of 100°C for 4 hours. Some Structural characteristics was studied by using X-ray diffraction (XRD)and optical microscope photograph some of chemical gas sensing measurements were carried out ,it shown that the sensitivity of (CO2) gas depend on the grain Size and deposition substrate. The grain size of PbS film deposited on on glass closed to 21.4 nm while 37.97nm for Si substrate. The result of current-voltage characterization shwon the sensitivity of prepared film deposited on Si better than film on glass.

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Publication Date
Sun Sep 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Contamination of Drilling Muds in Southern Iraqi Fields
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Publication Date
Sat Dec 28 2019
Journal Name
International Journal Of Simulation: Systems, Science & Technology
On the Estimation of Nonparametric Copula Density Functions
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In this research, we present a nonparametric approach for the estimation of a copula density using different kernel density methods. Different functions were used: Gaussian, Gumbel, Clayton, and Frank copula, and through various simulation experiments we generated the standard bivariate normal distribution at samples sizes (50, 100, 250 and 500), in both high and low dependency. Different kernel methods were used to estimate the probability density function of the copula with marginal of this bivariate distribution: Mirror – Reflection (MR), Beta Kernel (BK) and transformation kernel (KD) method, then a comparison was carried out between the three methods with all the experiments using the integrated mean squared error. Furthermore, some

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Publication Date
Mon Sep 30 2019
Journal Name
College Of Islamic Sciences
consideration In the purposes of faith and destiny
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consideration
In the purposes of faith and destiny

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Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
EFFICIENCY SPIHT IN COMPRESSION AND QUALITY OF IMAGE
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Image compression is an important tool to reduce the bandwidth and storage
requirements of practical image systems. To reduce the increasing demand of storage
space and transmission time compression techniques are the need of the day. Discrete
time wavelet transforms based image codec using Set Partitioning In Hierarchical
Trees (SPIHT) is implemented in this paper. Mean Square Error (MSE), Peak Signal
to Noise Ratio (PSNR) and Maximum Difference (MD) are used to measure the
picture quality of reconstructed image. MSE and PSNR are the most common picture
quality measures. Different kinds of test images are assessed in this work with
different compression ratios. The results show the high efficiency of SPIHT algori

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Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
Effect of Some predisposing factors on Vulvovaginal Candidiasis
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The predisposing factors and their effect on the increasing of vulvovaginal Candidiasis have been studied in this research. The result indicated that the highest of infection with vaginal Candidias was in the age of women with age of (21-30years) with vaginal itching and discharge, also the results revealed that the pregnancy was the main predisposing factor. The percentage of the infected pregnant Ladies was 33.7% followed by the women who used the IUCD and OCP 22.1%, those who used steroids 5.2% comparing with control women (without predisposing factors).The results also indicated that the most cases of infection were during the third trimester of pregnancy (where the rate of infedion) was 53.9%.-OCP- Oral Contraceptive Pills-IUCD- Intrr

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