Preferred Language
Articles
/
alkej-77
Experimental Estimation of Critical Buckling Velocities for Conservative Pipes Conveying Fluid
...Show More Authors

Conservative pipes conveying fluid such as pinned-pinned (p-p), clamped–pinned (c-p) pipes and clamped-clamped (c-c) lose their stability by buckling at certain critical fluid velocities. In order to experimentally evaluate these velocities, high flow-rate pumps that demand complicated fluid circuits must be used.

     This paper studies a new experimental approach based on estimating the critical velocities from the measurement of several fundamental natural frequencies .In this approach low flow-rate pumps and simple fluid circuit can be used.

Experiments were carried out on two pipe models at three different boundary conditions. The results showed that the present approach is more accurate for estimating the critical velocities of p-p and c-p pipes. However, for c-c pipes it was not so unless a higher flow rate is used.

 

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Crack Growth Behavior through Wall Pipes under Impact Load and Hygrothremal Environment
...Show More Authors

This research concerns study the crack growth in the wall of pipes made of low carbon steel under the impact load and using the effect of hygrothermal (rate of moisture 50% and 50℃ temperature). The environmental conditions were controlled using high accuracy digital control with sensors. The pipe have a crack already. The test was performed and on two type of specimens, one have length of 100cm and other have length 50cm. The results were, when the humidity was applied to the pipe, the crack would enhance to growth (i.e. the number of cycles needed to growth the crack will reduce). In addition, when the temperature was increase the number of cycles needed to growth the crack are reduced because the effect of heat on the mechanical pro

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Optical properties for prepared polyaniline / Ferro fluid nano composites
...Show More Authors

Pure nano Ferro fluid was synthesized by chemical co-precipitation method. The composite of polyaniline with nano sized Ferro fluid was prepared by In-situ–chemical oxidation polymerization method with ammonium per sulphate as an oxidant in aqueous hydrochloric acid under constant stirring at room temperature. The optical properties, absorption, transmission, optical energy gap (Eg) and optical constant refractive index (n) have been investigated. The value of the Eg decreased with increasing Ferro fluid concentration.

View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
Nano Fluid Detection for HPHE System Using Different Lasers
...Show More Authors

Among the different passive techniques heat pipe heat exchanger (HPHE) seems to be the most effective one for energy saving in heating ventilation and air conditioning system (HVAC). The applications for nanofluids with high conductivity are favorable to increase the thermal performance in HPHE. Even though the nanofluid has the higher heat conduction coefficient that dispels more heat theoretically but the higher concentration will make clustering .Clustering is a problem that must be solved before nanofluids can be considered for long-term practical uses. Results showed that the maximum value of relative power is 0.13 mW at nanofluid compared with other concentrations due to the low density of nanofluid at this concentration. For highe

... Show More
View Publication Preview PDF
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
1-DOF Model for Fluid-Structure-Interaction Vibration Analysis
...Show More Authors

In this paper an attempt to provide a single degree of freedom lumped model for fluid structure interaction (FSI) dynamical analysis will be presented. The model can be used to clarify some important concept in the FSI dynamics such as the added mass, added stiffness, added damping, wave coupling ,influence mass coefficient and critical fluid depth . The numerical results of the model show that the natural frequency decrease with the increasing of many parameters related to the structure and the fluid .It is found that the interaction phenomena can become weak or strong depending on the depth of the containing fluid .The damped and un damped free response are plotted in time domain and phase plane for different model parameters It is fou

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Baghdad Science Journal
Comparison between Biological Activities of Commercial and Synthesized Carbon Nanotubes by Flame Fragments Deposition Technique
...Show More Authors

Carbon nanotubes (CNTs) were synthesized via liquefied petroleum gas (LPG) as precursor using flame fragments deposition (FFD) technique. In vitro, biological activates of carbon nanotubes (CNTs) synthesized by FFD technique were investigated. The physiochemical characterizations of synthesized CNTs are similar to other synthesized CNTs and to the standard sample. Pharmaceutical application of synthesized CNTs was studied via conjugation and adsorption with different types of medicines as promote groups. The conjugation of CNTs was performed by adsorption the drugs such as sulfamethoxazole (SMX) and trimethoprim (TMP) on CNTs depending on physical properties of both bonded parts. The synthesized CNTs almost have the same performance in a

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Wed Oct 24 2018
Journal Name
Journal Of Economics And Administrative Sciences
"The Relationship critical factors for knowledge transfer in strategic success opportunities"
...Show More Authors

    The current research discusses "The Relationship critical factors for knowledge transfer in strategic success opportunities", the attention have been increased on knowledge transfer and strategic success subjects because on being one of the important and contemporary issues, which have a significant impact on the existence of organizations and its future. The research aims to identify the critical factors for knowledge transfer in private high education environment which enables (the college community surveyed) to achieve strategic success, also the research sought to answer questions related to research problem by testing a number of major and minor hypothes in correlation, in order to test the hypotheses I us

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Mar 01 2020
Journal Name
Journal Of Engineering
Thermal Buckling Analysis of Laminated Composite plates with General Elastic Boundary Supports
...Show More Authors

In this study, the modified Rayleigh-Ritz method and Fourier series are used to determine the thermal buckling behavior of laminated composite thin plates with a general elastic boundary condition applied to in-plane uniform temperature distribution depending upon classical laminated plate theory(CLPT). A generalized procedure solution is developed for the Rayleigh-Ritz method combined with the synthetic spring technique. The transverse displacement of the orthotropic rectangular plates is not a different term as a new shape expansion of trigonometric series. In this solution approach, the plate transverse deflection and rotation due to bending are developed into principle Fourier series with a sufficient smoothness auxi

... Show More
View Publication Preview PDF
Crossref (7)
Crossref
Publication Date
Tue Jun 11 2019
Journal Name
Al-kindy College Medical Journal
Conservative Treatment of Tuberculosis of the Spine in Patients with no Neurological Deficits
...Show More Authors

Background: Patients who have both neurological impairment and kyphotic deformity can be treated medically, and this treatment can be achieved with anti-tuberculous drugs alone.

Objective: To evaluate conservative medical management of patients with tuberculosis of the spine (Pott disease). The prognostic significance of various clinical, radiological, and long-term follow-up findings in these patients was also evaluated.

Methods: Between January 2009 and January 2018 data were collected prospectively at The Neurosciences Hospital/ Baghdad/ Iraq in 44 patients with Pott disease in the thoracic and lumbar spine. These patients had no major neurological deficits or

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Sep 01 2021
Journal Name
Journal Of Engineering
Thermal Buckling of Laminated Composite Plates Using a Simple Four Variable Plate Theory
...Show More Authors

In this study, the thermal buckling behavior of composite laminate plates cross-ply and angle-ply all edged simply supported subjected to a uniform temperature field is investigated, using a simple trigonometric shear deformation theory. Four unknown variables are involved in the theory, and satisfied the zero traction boundary condition on the surface without using shear correction factors, Hamilton's principle is used to derive equations of  motion depending on a Simple Four Variable Plate Theory for cross-ply and angle-ply, and then solved through Navier's double trigonometric sequence, to obtain critical buckling temperature for laminated composite plates. Effect of changing some design parameters such as, ortho

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Apr 03 2011
Journal Name
Journal Of Educational And Psychological Researches
The effect of critical listening in teaching reading on developing students critical thinking at Kurdish Language Department
...Show More Authors

Students' passive listening to their teacher's reading is one of main
reasons behindtheir weakness in the reading skill which in its turn may
hinderachieving the in desired objectives.
When exploiting critical thinking, which will lead to deeper
understanding of the intellectual content, in learning and accurate and
correct students' outcomes.
Active listening allows paying attention to the speaker, asking him,
arguing with him, judging what he says, and making decision on what
he says. For this reason, the researcher felt the need for preforming a
study to identify the effect of critical listening on developing students'
critical thinking at reading in the Kurdish language department.
The researcher has

... Show More
View Publication Preview PDF