Preferred Language
Articles
/
joe-928
Numerical Study of Fluid Flow and Heat Transfer Characteristics in Solid and Perforated Finned Heat Sinks Utilizing a Piezoelectric Fan
...Show More Authors

Numerical study is adapted to combine between piezoelectric fan as a turbulent air flow generator and perforated finned heat sinks. A single piezoelectric fan with different tip amplitudes placed eccentrically at the duct entrance. The problem of solid and perforated finned heat sinks is solved and analyzed numerically by using Ansys 17.2 fluent, and solving three dimensional energy and Navier–Stokes equations that set with RNG based k−ε scalable wall function turbulent model. Finite volume algorithm is used to solve both phases of solid and fluid. Calculations are done for three values of piezoelectric fan amplitudes 25 mm, 30 mm, and 40 mm, respectively. Results of this numerical study are compared with previous both numerical and experimental studies and give a good agreement. Numerical solution is invoked to explain the behavior of air flow and temperature distribution for two types of circular axial and lateral perforations. For each type, all the results are compared with an identical solid finned heat sink. Perforations show a remarkable enhanced in the heat transfer characteristics. The results achieved enhancement in the heat transfer coefficient about 12% in axial perforation and 25% in the lateral perforation at the maximum fan amplitude.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Engineering
Numerical and Experimental Investigations of the Effect of PVD and Vacuum Pressure on the Degree of Saturation
...Show More Authors

    Soft clays are generally characterized by low shear strength, low permeability and high compressibility. An effective method to accelerate consolidation of such soils is to use vertical drains along with vacuum preloading to encourage radial flow of water.  In this research numerical modeling of prefabricated vertical drains with vacuum pressure was done to investigate the effect of using vertical drains together with vacuum pressure on the degree of saturation of fully and saturated-unsaturated soft soils.  Laboratory experiments were conducted by using a specially-designed large consolidometer cell where a central drain was installed and vacuum pressure was applied. All tests were conducted

... Show More
View Publication Preview PDF
Publication Date
Wed Apr 30 2025
Journal Name
Iraqi Journal Of Science
Determination of Cobalt(II) Ion in Various Selected Alloys via Utilizing Continous Flow Injection Analysis ((CFIA) (Nagham-Four Sources of White  Snow LED Arranged in Three Rows Corresponding to Three Detectors Analyzer) (NAG-4SX3-3D)) Analyzer at 0-180o Angle
...Show More Authors

The research study focuses on the efficient and accurate detection and determination of cobalt ions. The detection method involves the formation of brilliant green aggregates with calcium hexacyanoferrate in the presence of nitric acid. (Nagham-four sources of white snow light-emitting diodes arranged in three rows corresponding to three detectors) (The NAG-4SX3-3D Analyzer is an optical, chemical, electronic, and detection tool that receives a cumulative signal (no amplification is required). The total distance travelled is 760 mm with regard to YZ(mV) - tsec (dmm). It was selected for its precise calculation of the energy transducer profile. The linear range for measuring cobalt (II) ions is 0.05 to 20 mM. For concentrations of 5

... Show More
View Publication
Scopus Crossref
Publication Date
Mon Nov 01 2021
Journal Name
Proceedings Of First International Conference On Mathematical Modeling And Computational Science: Icmmcs 2020
Study the Stability for Ordinary Differential Equations Using New Techniques via Numerical Methods
...Show More Authors

Nonlinear differential equation stability is a very important feature of applied mathematics, as it has a wide variety of applications in both practical and physical life problems. The major object of the manuscript is to discuss and apply several techniques using modify the Krasovskii's method and the modify variable gradient method which are used to check the stability for some kinds of linear or nonlinear differential equations. Lyapunov function is constructed using the variable gradient method and Krasovskii’s method to estimate the stability of nonlinear systems. If the function of Lyapunov is positive, it implies that the nonlinear system is asymptotically stable. For the nonlinear systems, stability is still difficult even though

... Show More
Scopus (8)
Scopus
Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Vibration Characteristics Oblate Shell "With and Without Framed Structure"
...Show More Authors

This paper presents the results of investigating the vibrational characteristics of oblate dish with and without framed structure . A finite element method, was applied to the dynamic analysis of oblate spheroidal shell. Different types of elements were considered in one dimension and two dimensions. It was found that the natural frequencies of oblate shells had two types of behavior against increasing the shell thickness and eccentricity, which are the membrane mode and bending mode –Since – the membrane modes natural frequencies tend to increase with the increasing the eccentricity of oblate, while the bending modes natural frequencies decrease with the increasing the eccentricity till reach the optimum eccentricity.

 

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 01 2015
Journal Name
Political Sciences Journal
The political dimension Engineering social characteristics and Alssayashllansan community
...Show More Authors

تستهدف هذه الدراسة وبشكل أساس، الكشف عن طبيعة وخصائص البعد السياسي لهندسة/صناعة الخصائص الاجتماعية والسياسية للإنسان والمجتمع، بوصفها العملية المسؤولة عن تصميم هذه الخصائص وصناعتها وتغييرها جزئيا أو كليا، دون أبعادها الأخرى المتعددة والمتنوعة، لا لمجرد الانسياق وراء دوافع الرغبة الذاتية، أو اعتبارات التخصص الدقيق وأحكامه، لأن معهما أيضا، بل وقبلهما أحيانا، دوافع واعتبارات أخرى موضوع

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Oct 02 2024
Journal Name
Translation&linguistics
Verbal forms in French and Iraqi Arabic: a contrastive study
...Show More Authors

View Publication Preview PDF
Publication Date
Thu Aug 25 2022
Journal Name
Ira International Journal Of Education And Multidisciplinary Studies
Gender and Olds’ Advice in Written Signs: A Pragmatic Study
...Show More Authors

Giving advice refers to an attempt by the speaker to express what the addressee should do in a particular situation or what is good for him/her. It is also a feature of making social relations and communications move smoothly and become stronger. The current study aims to investigate the strategies of the speech act of advice by old females and males for the younger generation in written signs. Comparison is made between old females and males regarding their pragmatic use of advice and the way they are manifested in expressing gender identity differences. The sample of the study consists of (30) written signs of advice divided equally between the two gender groups. Hinkel’s (1997) classification of the strategies for perceiving th

... Show More
View Publication
Crossref
Publication Date
Thu Oct 01 2015
Journal Name
Al–bahith Al–a'alami
Correspondents and Professional Standards in News Coverage (A Field Study)
...Show More Authors

         The essence of the new work in the satellite TV channels is to provide news coverage of news that will inform the people of what is going on around them in order to increase their political, social, economic and cultural awareness and this drives them to take positions or certain behaviors on according to what the communicator in these channels wants. News and news reports are generally used as a psychological variable to influence public opinion and does not offer interestingness and information. Therefore, satellite TV channels have assumed special attention towards their correspondents desiring to achieve scoop in news coverage and to have the final word in reading events and install it

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 12 2017
Journal Name
Al-khwarizmi Engineering Journal
Model Reference Adaptive Control based on a Self-Recurrent Wavelet Neural Network Utilizing Micro Artificial Immune Systems
...Show More Authors

Abstract 

This paper presents an intelligent model reference adaptive control (MRAC) utilizing a self-recurrent wavelet neural network (SRWNN) to control nonlinear systems. The proposed SRWNN is an improved version of a previously reported wavelet neural network (WNN). In particular, this improvement was achieved by adopting two modifications to the original WNN structure. These modifications include, firstly, the utilization of a specific initialization phase to improve the convergence to the optimal weight values, and secondly, the inclusion of self-feedback weights to the wavelons of the wavelet layer. Furthermore, an on-line training procedure was proposed to enhance the control per

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of Multistage and Numerical Discretization Methods for Estimating Parameters in Nonlinear Linear Ordinary Differential Equations Models.
...Show More Authors

Many of the dynamic processes in different sciences are described by models of differential equations. These models explain the change in the behavior of the studied process over time by linking the behavior of the process under study with its derivatives. These models often contain constant and time-varying parameters that vary according to the nature of the process under study in this We will estimate the constant and time-varying parameters in a sequential method in several stages. In the first stage, the state variables and their derivatives are estimated in the method of penalized splines(p- splines) . In the second stage we use pseudo lest square to estimate constant parameters, For the third stage, the rem

... Show More
View Publication Preview PDF
Crossref