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
Thu Jun 20 2024
Journal Name
Acta Facultatis Medicae Naissensis
Clinical properties and seminal fluid analysis of patients with primary infertility consulting the urology outpatient clinic for the first time: A cross-sectional study
...Show More Authors

Introduction/Aim. Seminal fluid analysis (SFA) plays a crucial role in helping infertility clinics diagnose the underlying reason of male infertility. The aim of the study was to investigate seminal fluid patterns of male partners of an infertile couple with apparently fertile female partners. Materials and methods. A cross-sectional study was conducted between January 2019 and December 2022. Patients were attending consultations for delayed conception for more than 12 months with apparently fertile female partner. Results. Four hundred fifty-three patients were included in the study. The distribution of patients according to age groups showed that 277 patients were young, aged 21 - 30 years (61%). Two hundred sixty-two (58%) patien

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Thu Oct 01 2026
Journal Name
Next Materials
Valorization of aluminum waste wire into nanostructured Al2O3: Sustainable synthesis, characterization, and evaluation as a drilling-fluid additive for the oil and gas industry
...Show More Authors

Industrial machining workshops generate substantial quantities of aluminum wire offcuts and filings that cannot be re-entered into bulk metal recycling circuits, posing both a resource management challenge and a potential environmental burden. This study demonstrates a closed-loop valorization route in which this low-grade aluminum waste is converted into nanostructured aluminum oxide (Al2O3) nanoparticles (NPs) by two scalable synthesis pathways (i) chemo-thermal calcination of precipitated Al(OH)₃ at 1000 °C and 1200 °C for 1 and 4 h, and (ii) direct chemical precipitation via AlCl3/Na2CO3 reaction, and then deployed as a functional additive in water-based drilling fluids (WBDFs) used by the oil and gas industry. Comprehensive chara

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sun Sep 19 2021
Journal Name
Journal Of Petroleum Research And Studies
Enhancing the Rheological Properties of Water-Based Drilling Fluid by Utilizing of Environmentally-Friendly Materials
...Show More Authors

Recently, many materials have shown that they can be used as alternatives to chemicals materials in order to be used to improve the properties of drilling fluids. Some of these materials are banana peels and corn cobs which both are considered environmentally- friendly materials. The results of the X-ray diffraction examination have proved that the main components of these materials are cellulose and hemicellulose, which contribute greatly to the increasing of the effectiveness of these two materials. Due to their distinct composition, these two materials have improved the rheological properties (plastic viscosity and yield point) and reduced the filtration of the drilling fluids to a large extent. The addition rates used for each o

... Show More
View Publication
Crossref (8)
Crossref
Publication Date
Fri Jun 30 2023
Journal Name
Journal Of The College Of Education For Women
The Construction of the Iraqi Child in the UNICEF Reports during Covid19 Pandemic: A Critical Discourse Analysis
...Show More Authors

The present paper aims at investigating the linguistic image portrayed by UNICEF reports on the Iraqi child from a critical discourse analysis perspective during Covid19 pandemic (2020). The paper attempts to fill a gap in research literature concerning the linguistic construction of the Iraqi child by the UNICEF reports during the critical health crisis of Covid19. Van  Leeuwen’s (2008) approach of social actor representation has been adopted for this purpose. From Van  Leeuwen’s approach, the category of determination (single determination and overdetermination) has been selected to be the main analytical tool for its high compatibility with the set of objectives put forward to figure out how such a globally effective and

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Performance of Gas Induction in a Dual – Impeller Agitated Bioreactor
...Show More Authors

The rate of gas induction was measured in gas-inducing type mechanically agitated contactors provided with two impellers. A reactor of 0.5 m i.d. was used with a working capacity of 60 liters of liquid. Tap water was used as the liquid phase, and air was used as the gas phase. The bioreactor mixing system consists of two equal diameter stirrers; the top impeller is shrouded-disk/curved-blade turbine with six evacuated bending blades, while the bottom impeller was disk turbine. The impeller speed was varied in the range of 50 to 800 rpm. The ratio of impeller diameter to tank diameter (D/T) and the submergence (S) of upper impeller from the top were varied. The effects of clearance of lower impeller from the tank bottom (C2) an

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 02 2022
Journal Name
Journal Of The College Of Languages (jcl)
Ideological Polarization as a Deception Strategy in the Discourse of American Think Tanks: A Critical Discourse Analysis
...Show More Authors

Deception is an inseparable facet of political discourse in attaining strategic political gains though compromising public opinion. However, the employment of discursive deception strategies by the policy-making institutions of think tanks has not received due attention in the literature. The current study aims at exploring how the ideologizing deception strategies are utilized by the conservative American think tank of the Washington Institute to reproduce socio-political realities and re-shape public opinion. To fulfill this task, van Dijk’s (2000) notion of ideological polarization which shows positive self-representation and negative other representation is adopted to conduct a critical discourse analysis of four Arabic texts relea

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Fri Jan 15 2021
Journal Name
المجلة العربية للبحوث الادبية والانسانسة
‬: COVID- القيادة الخدمية ورضا الزبون في ظل ازمة جائحة 19 تجريبي لقيادات المنظمات العامة في العراق بحث
...Show More Authors

يهدف البحث الحالي الى التعرف إلى درجة تقدير عينة من المديرين في المنظمات العامة لمستوى تطبيق ولتحقيق ، (Covid- نمط القيادة الخدمية من وجهة نظرهم ، وعلاقتها بمؤشر رضا الزبائن في ظل جائحة ( 19 ذلك اتبعت الباحثة المنهج التجريبي بتطبيق استبانة ضمت محورين، الأول: لقياس مستوى القيادة االخدمية وفقا الذي يشمل ( 8) أبعاد هي ( التمكين , الدعم , ( D. Van Dierendonck and I. Nuijten , لمقياس ( 2011 المساءلة, الشجاعة, التسامح , الموثوقية , التواضع , الر

... Show More
Publication Date
Thu Sep 06 2018
Journal Name
Al-khwarizmi Engineering Journal
Bone Defect Animal Model for Hybrid Polymer Matrix Nano Composite as Bone Substitute Biomaterials
...Show More Authors

Addition of bioactive materials such as Titanium oxide (TiO2), and incorporation of bio inert ceramic such as alumina (Al2O3), into polyetheretherketone (PEEK) has been adopted as an effective approach to improve bone-implant interfaces. In this paper, hot pressing technique has been adopted as a production method. This technique gave a homogenous distribution of the additive materials in the proposed composite biomaterial. Different compositions and compounding temperatures have been applied to all samples. Mechanical properties and animal model have been studied in all different production conditions. The results of these new TiO2/Al2O3/PEEK biocomposites with different

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of estimation methods for regression model parametersIn the case of the problem of linear multiplicity and abnormal values
...Show More Authors

 A simulation study is used to examine the robustness of some estimators on a multiple linear regression model with problems of multicollinearity and non-normal errors, the Ordinary least Squares (LS) ,Ridge Regression, Ridge Least Absolute Value (RLAV), Weighted Ridge (WRID), MM and a robust ridge regression estimator MM estimator, which denoted as RMM this is the modification of the Ridge regression by incorporating robust MM estimator . finialy, we show that RMM is the best among the other estimators

View Publication Preview PDF
Crossref
Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Engineering
Preparation of Design Charts for Estimation of the Length of an Upstream Impervious Blanket in a Homogenous Earth Dam
...Show More Authors