Preferred Language
Articles
/
alkej-463
Numerical Investigation of Transient Heat Conduction through a Thermal Insulation of Temperature Dependant Thermal Properties
...Show More Authors

The two-dimensional transient heat conduction through a thermal insulation of temperature dependent thermal properties is investigated numerically using the FVM. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner surface with a step change in temperature and subjected at its outer surface with a natural convection boundary condition associated with a periodic change in ambient temperature and heat flux of solar radiation. Two thermal insulation materials were selected. The fully implicit time scheme is selected to represent the time discretization. The arithmetic mean thermal conductivity is chosen to be the value of the approximated thermal conductivity at the interface between adjacent control volumes. A temperature dependent specific heat capacity proposed by a 4th Degree polynomial is fitted. A good agreement is obtained when the predicted results are compared with those obtained from the analytical solution.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
Solutions and Recent Challenges Related to Energy in Wireless Body Area Networks with Integrated Technologies: Applications and Perspectives
...Show More Authors

          In this paper, we have investigated some of the most recent energy efficient routing protocols for wireless body area networks. This technology has seen advancements in recent times where wireless sensors are injected in the human body to sense and measure body parameters like temperature, heartbeat and glucose level. These tiny wireless sensors gather body data information and send it over a wireless network to the base station. The data measurements are examined by the doctor or   physician and the suitable cure is suggested. The whole communication is done through routing protocols in a network environment. Routing protocol consumes energy while helping non-stop communic

... Show More
View Publication Preview PDF
Scopus (11)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Fri Sep 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
Semi Parametric Logistic Regression Model with the Outputs Representing Trapezoidal Intuitionistic Fuzzy Number
...Show More Authors

In this paper, the fuzzy logic and the trapezoidal fuzzy intuitionistic number were presented, as well as some properties of the trapezoidal fuzzy intuitionistic number and semi- parametric logistic regression model when using the trapezoidal fuzzy intuitionistic number. The output variable represents the dependent variable sometimes cannot be determined in only two cases (response, non-response)or (success, failure) and more than two responses, especially in medical studies; therefore so, use a semi parametric logistic regression model with the output variable (dependent variable) representing a trapezoidal fuzzy intuitionistic number.

the model was estimated on simulati

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sun Jan 01 1995
Journal Name
كلية العلوم / جامعة بغداد
تحضير ودراسة طيفية وحرارية لمعقدات بعض العناصر الإنتقالية مع ليكانـــــد 4- (2- بريديل آزو)- ريزورسينول
...Show More Authors

لقد حضر في هذا البحث عدد من المعقدات الجديدة لبعض ايونات العناصر الانتقالية وهي كل من Fe(II) , Fe(III) , Co(II) , Ni(II) , Cu(II) و Zn(II) مع الكاشف العضوي -4 ( -2 بريديل آزو ) ريزورسينول المعروف ب (PAR) . حيث تم التحضير بعد تثبيت الظروف المثلى من دالة حامضية وتركيز مولاري بوساطة أطياف الاشعة فوق البنفسجية – المرئية لمحاليل مزج الايونات الفلزية مع محاليل الكاشف العضوي اعلاه ولمدى واسع من الدالة الحامضية والتركيز المولارية الخاضعة لقانو

... Show More
Publication Date
Wed Oct 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
بناء إنموذج رياضي لتعظيم عائد الشركة الإنتاجية بإستعمال البرمجة الكسرية الخطية الصحيحة – مع تطبيق عملي
...Show More Authors

These search summaries in building a mathematical model to the issue of Integer linear Fractional programming and finding the best solution of Integer linear Fractional programming (I.L.F.P) that maximize the productivity of the company,s revenue by using the largest possible number of production units and maximizing denominator objective which represents,s proportion of profits to the costs, thus maximizing total profit of the company at the lowest cost through using Dinkelbach algorithm and the complementary method on the Light industries company data for 2013 and comparing results with Goal programming methods results.

It is clear that the final results of resolution and Dinkelbac

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Dec 01 2022
Journal Name
Baghdad Science Journal
Comparison between RSA and CAST-128 with Adaptive Key for Video Frames Encryption with Highest Average Entropy
...Show More Authors

Encryption of data is translating data to another shape or symbol which enables people only with an access to the secret key or a password that can read it. The data which are encrypted are generally referred to as cipher text, while data which are unencrypted are known plain text. Entropy can be used as a measure which gives the number of bits that are needed for coding the data of an image. As the values of pixel within an image are dispensed through further gray-levels, the entropy increases. The aim of this research is to compare between CAST-128 with proposed adaptive key and RSA encryption methods for video frames to determine the more accurate method with highest entropy. The first method is achieved by applying the "CAST-128" and

... Show More
View Publication Preview PDF
Scopus (8)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sun Oct 20 2024
Journal Name
Engineering Reports
A Theoretical and Experimental Investigation of the Effects of Inverted Wings Modifications on the Stability and Aerodynamic Performance of a Sedan Car at Cornering
...Show More Authors
ABSTRACT<p>This research examines the impact of cornering on the aerodynamic forces and stability of a Nissan Versa (Almera) passenger sedan car by introducing novel modifications. These modifications included single inverted wings with end plates as a front spoiler, double‐element inverted wings with end plates as a rear spoiler, and incorporating the ground as a diffuser under the car trunk. The goal is to enhance the performance and stability of conventional passenger cars. To ensure the accuracy of the numerical data, the study utilized multiple methodologies to model the turbulence model, ultimately selecting the most suitable option. This involved comparing numerical data with wind tunnel experimental d</p> ... Show More
View Publication
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Mon May 11 2020
Journal Name
Baghdad Science Journal
Estimating Lipoxygenase and Gamma-glutamyl Transferase Activities in Sera of Colon Cancer Patients with Partial Purification of Lipoxygenase
...Show More Authors

            Colon cancer is an abnormal growth of cells that occurs in the large intestine. Sometimes growth remains restricted for a relatively long time before it becomes a malignant tumor and then spreads through the intestinal wall to the lymph nodes and other parts of the body. The study aims to estimate the effectiveness and partial purification of lipoxygenase (LOX) enzyme and measure gamma-glutamyle transferase (GGT) activity in serum patients of colon cancer in Baghdad. The study included (80) case male patients with colon cancer with (50) samples of apparently healthy males (control) as comparison group. The result displayed a noteworthy increase in lipoxygenase effectivene

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
MIXED CONVECTIVE AND RADIATIVE HEAT TRANSFER IN A HORIZONTAL CONCENTRIC AND ECCENTRIC CYLINDRICAL ANNULI
...Show More Authors

A numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperature
while the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) was
used to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.
A computer progra

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Nov 01 2021
Journal Name
Energies
Solidification Enhancement in a Triple-Tube Latent Heat Energy Storage System Using Twisted Fins
...Show More Authors

This work evaluates the influence of combining twisted fins in a triple-tube heat exchanger utilised for latent heat thermal energy storage (LHTES) in three-dimensional numerical simulation and comparing the outcome with the cases of the straight fins and no fins. The phase change material (PCM) is in the annulus between the inner and the outer tube, these tubes include a cold fluid that flows in the counter current path, to solidify the PCM and release the heat storage energy. The performance of the unit was assessed based on the liquid fraction and temperature profiles as well as solidification and the energy storage rate. This study aims to find suitable and efficient fins number and the optimum values of the Re and the inlet tem

... Show More
View Publication
Scopus (43)
Crossref (43)
Scopus Clarivate Crossref
Publication Date
Sat May 01 2021
Journal Name
Key Engineering Materials
The Effect of Temperature Width on Dielectric Constant of Vanadium Dioxide
...Show More Authors

A significant influence of temperature width found on the vanadium oxide properties, it plays a major role in highlighting the thermal limits of the three phases (metallic, semiconductor, and dielectric). Two values of the temperature width , and , had taken and studied their effect on both the dielectric constant and its two parts; refractive index, and extinction coefficient, and. It found that: as the temperature width is greater, the more the properties of the three phases for . In addition to increasing the thermal range for phases which can be reached to when , while it's at . Our results have achieved great compatibility with the published results globally. In addition to the effect of both ultraviolet, visible, and infrared

... Show More
View Publication
Scopus (4)
Crossref (5)
Scopus Crossref