Preferred Language
Articles
/
joe-2109
Experimental Study of Power Increase Transient in Heat Generation Systems Simulated By Immersed Heat Source
...Show More Authors

Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulus and solved by using Laplace method to
determine the variation of bulk water temperature. The experimental investigation included a set of experiments carried out to investigate the temperature variation along the heat source for power increase transient of (5%, 10%, 15% and 20%) of its nominal value during and after reaching the steady state condition. Estimation of the boiling safety factor is predicted and compared with the theoretical values. Reliable agreement between experimental and theoretical approaches is reached. The later showed that the elapsed time required for the clad surface temperature to reach its steady state values after each transient is less than that related to bulk water temperature. New correlation for prediction of critical heat flux, CHF based on inlet water temperature and water mass flux are investigated and compared with CHF correlations obtained from previous researches. Specific recommendations concerned with preventive measured required to eliminate the effect of boiling crisis are concluded based on theoretical and experimental results related to transients setting times obtained from each case study.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Feb 18 2022
Journal Name
Journal Of Engineering And Sustainable Development
CONJUGATE NATURAL CONVECTION IN A POROUS ENCLOSURE SANDWICHED BY FINITE WALLS AND SUBJECTED TO CONVECTION COOLING CONDITION
...Show More Authors

Steady conjugate natural convection heat transfers in a two-dimensional enclosure filled with fluid saturated porous medium is studied numerically. The two vertical boundaries of the enclosure are kept isothermally at same temperature, the horizontal upper wall is adiabatic, and the horizontal lower wall is partially heated. The Darcy extended Brinkman Forcheimer model is used as the momentum equation and Ansys Fluent software is utilized to solve the governing equations. Rayleigh number (1.38 ≤ Ra ≤ 2.32), Darcy number (3.9 * 10-8), the ratio of conjugate wall thickness to its height (0.025 ≤ W ≤ 0.1), heater length to the bottom wall ratio (1/4 ≤  ≤ 3/4) and inclination angle (0°, 30° and 60°) are the main consid

... Show More
View Publication
Scopus Crossref
Publication Date
Fri Dec 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Enhancing Vegetative Growth by Adding Phosphorus, Silicon, and Citric Acid to Pepper Plants Cultivated in Plastic Greenhouses
...Show More Authors
Abstract<p>The research was conducted in a plastic greenhouse at the College of Agricultural Engineering Sciences, University of Baghdad - Jadiriyah Campus, during the 2021-2022 season, to study the effect of phosphorus, silicon, and citric acid on pepper plants using a factorial experiment design with three replicates. The first factor had three levels of phosphorus (0, 160, and 320 kg P<sub>2</sub>O<sub>5</sub> per hectare), the second factor had three levels of potassium silicate (0, 75, and 100 kg per hectare), and the third factor had four levels of citric acid (0, 2, 4, and 6 kg per hectare). The statistical analysis showed that treatment P2S2C1 resulted in an increase </p> ... Show More
View Publication
Scopus (3)
Scopus Crossref
Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
A Modified Approach by Using Prediction to Build a Best Threshold in ARX Model with Practical Application
...Show More Authors

The proposal of nonlinear models is one of the most important methods in time series analysis, which has a wide potential for predicting various phenomena, including physical, engineering and economic, by studying the characteristics of random disturbances in order to arrive at accurate predictions.

In this, the autoregressive model with exogenous variable was built using a threshold as the first method, using two proposed approaches that were used to determine the best cutting point of [the predictability forward (forecasting) and the predictability in the time series (prediction), through the threshold point indicator]. B-J seasonal models are used as a second method based on the principle of the two proposed approaches in dete

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Effect of Design Parameters and Support Conditions on Natural Frequency of Pipe Excited by a Turbulent Internal Flow
...Show More Authors

In this study, the effect of design parameters such as pipe diameter, pipe wall thickness, pipe material and the effect of fluid velocity on the natural frequency of fluid-structure interaction in straight pipe conveying fully developed turbulent flow were investigate numerically,analytically and experimentally. Also the effect of support conditions, simply-simply and clamped-clamped was investigated. Experimentally, pipe vibrations were characterized by accelerometer mounted on the pipe wall. The natural frequencies of vibration were analyzed by using Fast Fourier Transformer (FFT). Five test sections of two different pipe diameters of 76.2
mm and 50.8 mm with two pipe thicknesses of 3.7 mm and 2.4 mm and two pipe materials,stainles

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Nov 19 2020
Journal Name
Indonesian Journal Of Chemistry
Determination of Eugenol in Personal-Care Products by Dispersive Liquid-Liquid Microextraction Followed by Spectrophotometry Using &lt;i&gt;p&lt;/i&gt;-Amino-&lt;i&gt;N,N&lt;/i&gt;-dimethylaniline as a Derivatizing Agent
...Show More Authors

Two simple methods for the determination of eugenol were developed. The first depends on the oxidative coupling of eugenol with p-amino-N,N-dimethylaniline (PADA) in the presence of K3[Fe(CN)6]. A linear regression calibration plot for eugenol was constructed at 600 nm, within a concentration range of 0.25-2.50 μg.mL–1 and a correlation coefficient (r) value of 0.9988. The limits of detection (LOD) and quantitation (LOQ) were 0.086 and 0.284 μg.mL–1, respectively. The second method is based on the dispersive liquid-liquid microextraction of the derivatized oxidative coupling product of eugenol with PADA. Under the optimized extraction procedure, the extracted colored product was determined spectrophotometrically at 618 nm. A l

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Wed Feb 01 2017
Journal Name
International Journal Of Science And Research (ijsr)
Performance Evaluation of the Organic Matter Removal Efficiency in Wastewater Treatment Plants; Case study Al- Diwaniyah WWTP in Iraq
...Show More Authors

This study aims to assess the removal efficiency andestablish the BOD5 and COD statisticalcorrelation of the sewage flowing in Al-Diwaniyah wastewater treatment plant in Iraq during the study period (2005-2016). The strength of the influent wastewater entering the plant varied from medium to high in strength. High concentrations of BOD5 and COD in the effluent were obtained due to the poor performance of the plant. This was observed from the BOD5 /COD ratios that did not confirm with the typical ratios for the treated sewage. To improve the performance of this plant, regression equations for BOD5 and COD removal percentages were suggested which can be used to facilitate evaluation of liquid waste and optimal control process. The equations

... Show More
Publication Date
Thu Feb 12 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Elevation in surface temperature of root canals obturated with different thermoplasticized gutta-percha obturation techniques-an in vitro study
...Show More Authors

Background: Many studies have been conducted to evaluate the effect of using a hot material in the root canal and its potential for causing damage to the tooth supporting structure. Materials and methods: thirty permanent premolars were obturated with thermoplasticized Gutta-Percha using three different obturation techniques: soft core, Thermafil, and obtura to evaluate the rise in temperature on the root surface using a multipurpose digital thermometer. Results: temperature increases was significantly greater for Obtura versus Soft core (p<0.003), not significant for Thermafil versus Soft core (p<0.087), and Thermafil versus Obtura (p<0.125). Conclusions: temperatures rise on the root surface were below the critical level and, therefore, s

... Show More
View Publication Preview PDF
Publication Date
Wed Jan 30 2013
Journal Name
Al-kindy College Medical Journal
Regeneration of Pain, Touch, Cold, and Warmth, sensations in split thickness human skin grafts in adults (A clinical study)
...Show More Authors

Back ground: Skin grafting is the most common form
of reconstructive surgery, and regeneration of
sensations in skin grafts is a complex process
influenced by many factors such as , the thickness of
the graft, the depth of the grafted bed, meshing of the
graft, the condition of the bed and the surrounding
area. So many studies performed on this subject, some
of them clinically based on subjective type of sensation
tests, and others histological to detect the presence of
nerve fibers in the grafted skin
Objectives: To detect return of sensations to split
thickness skin grafts by clinical methods.
Methods: From Oct. 1995 to Oct. 2010, a clinical
prospective study performed in Al wasity Hospital for

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 05 2010
Journal Name
Baghdad Science Journal
Study the incidence of Candida infection in Diabetic patients submitted to the Balad Town Hospital in Salah –Eldeen, Province
...Show More Authors

This study was done at Al-Balad City Hospital on 60 diabetic patients (25 male and 35 female). The study included Fasting Blood Sugar and fungal diagnosis (systemic and superficial fungus). The results showed that the high concentration of blood sugar belonged to the group > 70 years among the diabetic patients with high significant differences in comparison with other groups P<0.001 . The result showed that percentage of female systemic fungus infection was higher than male systemic fungus infection ( female 63% and male 24%) and vice versa about superficial fungus infection (female 37% and male 76%) . Data showed that the percentage of nail fungus infection among female diabetic patients was higher than the percentage of male diabetic p

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Sep 30 2023
Journal Name
Journal Of The College Of Education For Women
Alternative Sanctions and their Impact on Societal Security: A Field Study in the Directorate of Juveniles Reformatory in Baghdad
...Show More Authors

Crime is one of the most severe challenges facing States, and strives to find preventive measures, reduce its seriousness, and prevent them; due to developments, crimes have increased, and emerging new patterns of crimes, there is an urgent need to prevent crimes and reduce their effects. Modernizing its punitive system and diverting it to correctional rehabilitative justice to redress the prejudice caused by the crime and rehabilitate the convicted person by using alternative measures to short-term imprisonment. This research emphasizes alternative sanctions' value to minimizing short-term imprisonment penalties and their impact on societal security through several goals like, the negative consequences, justifications, and alternatives

... Show More
View Publication Preview PDF
Crossref